Sample records for tlv threshold limit

  1. Boolean Threshold Networks: Virtues and Limitations for Biological Modeling

    E-Print Network [OSTI]

    Jorge G. T. Zañudo; Maximino Aldana; Gustavo Martínez-Mekler

    2010-11-16T23:59:59.000Z

    Boolean threshold networks have recently been proposed as useful tools to model the dynamics of genetic regulatory networks, and have been successfully applied to describe the cell cycles of \\textit{S. cerevisiae} and \\textit{S. pombe}. Threshold networks assume that gene regulation processes are additive. This, however, contrasts with the mechanism proposed by S. Kauffman in which each of the logic functions must be carefully constructed to accurately take into account the combinatorial nature of gene regulation. While Kauffman Boolean networks have been extensively studied and proved to have the necessary properties required for modeling the fundamental characteristics of genetic regulatory networks, not much is known about the essential properties of threshold networks. Here we study the dynamical properties of these networks with different connectivities, activator-repressor proportions, activator-repressor strengths and different thresholds. Special attention is paid to the way in which the threshold value affects the dynamical regime in which the network operates and the structure of the attractor landscape. We find that only for a very restricted set of parameters, these networks show dynamical properties consistent with what is observed in biological systems. The virtues of these properties and the possible problems related with the restrictions are discussed and related to earlier work that uses these kind of models.

  2. Ultimate limit in low threshold quantum well GaAlAs semiconductor lasers

    SciTech Connect (OSTI)

    Lau, K.Y.; Derry, P.L.; Yariv, A.

    1988-01-11T23:59:59.000Z

    Gain measurements were performed on buried heterostructure single quantum well lasers to ascertain the transparency current density, which represents a basic limit in the threshold current. By using the optimal design approach, a lowest threshold of 0.55 mA in a 120-..mu..m-long device was achieved. Modulation of the low threshold laser by a pseudorandom digital stream at 1.3 Gbit/s without current bias is demonstrated.

  3. Limiting absorption principle for some long range perturbations of Dirac systems at threshold energies

    E-Print Network [OSTI]

    Nabile Boussaid; Sylvain Golénia

    2009-06-08T23:59:59.000Z

    We establish a limiting absorption principle for some long range perturbations of the Dirac systems at threshold energies. We cover multi-center interactions with small coupling constants. The analysis is reduced to study a family of non-self-adjoint operators. The technique is based on a positive commutator theory for non self-adjoint operators, which we develop in appendix. We also discuss some applications to the dispersive Helmholzt model in the quantum regime.

  4. Theoretical Limit to the Laser Threshold Current Density in an InGaN Quantume Well Laser

    SciTech Connect (OSTI)

    Amano, H; Chow, W W; Han, J

    1998-10-09T23:59:59.000Z

    This paper describes an investigation of the spontaneous emission limit to the laser threshold current density in an InGaN quantum well laser. The peak gain and spontaneous emission rate as functions of carrier density are com- puted using a microscopic laser theory. From these quantities, the minimum achievable threshold current density is determined for a given threshold gain. The dependence on quantum well width, and the effects of inhomogeneous broadening due to spatial alloy variations are discussed. Also, comparison with experiments is made.

  5. Blister Threshold Based Thermal Limits for the U-Mo Monolithic Fuel System

    SciTech Connect (OSTI)

    D. M. Wachs; I. Glagolenko; F. J. Rice; A. B. Robinson; B. H. Rabin; M. K. Meyer

    2012-10-01T23:59:59.000Z

    Fuel failure is most commonly induced in research and test reactor fuel elements by exposure to an under-cooled or over-power condition that results in the fuel temperature exceeding a critical threshold above which blisters form on the plate. These conditions can be triggered by normal operational transients (i.e. temperature overshoots that may occur during reactor startup or power shifts) or mild upset events (e.g., pump coastdown, small blockages, mis-loading of fuel elements into higher-than-planned power positions, etc.). The rise in temperature has a number of general impacts on the state of a fuel plate that include, for example, stress relaxation in the cladding (due to differential thermal expansion), softening of the cladding, increased mobility of fission gases, and increased fission-gas pressure in pores, all of which can encourage the formation of blisters on the fuel-plate surface. These blisters consist of raised regions on the surface of fuel plates that occur when the cladding plastically deforms in response to fission-gas pressure in large pores in the fuel meat and/or mechanical buckling of the cladding over damaged regions in the fuel meat. The blister temperature threshold decreases with irradiation because the mechanical properties of the fuel plate degrade while under irradiation (due to irradiation damage and fission-product accumulation) and because the fission-gas inventory progressively increases (and, thus, so does the gas pressure in pores).

  6. Investigation of stimulated raman scattering using short-pulse diffraction limited laser beam near the instability threshold

    SciTech Connect (OSTI)

    Kline, John L [Los Alamos National Laboratory; Montgomery, David S [Los Alamos National Laboratory; Flippo, Kirk A [Los Alamos National Laboratory; Rose, Harvey A [Los Alamos National Laboratory; Yin, L [Los Alamos National Laboratory; Albright, B J [Los Alamos National Laboratory; Johnson, R P [Los Alamos National Laboratory; Shimada, T [Los Alamos National Laboratory; Bowers, K [Los Alamos National Laboratory; Rousseaux, C [CEA; Tassin, V [CEA; Baton, S D [FRANCE; Amiranoff, F [FRANCE; Hardin, R A [WEST VIRGINIA UNIV

    2008-01-01T23:59:59.000Z

    Short pulse laser plasma interaction experiments using diffraction limited beams provide an excellent platform to investigate the fundamental physics of Stimulated Raman Scattering. Detailed understanding of these laser plasma instabilities impacts the current inertial confinement fusion ignition designs and could potentially impact fast ignition when higher energy lasers are used with longer pulse durations ( > 1 kJ and> 1 ps). Using short laser pulses, experiments can be modeled over the entire interaction time of the laser using particle-in-cell codes to validate our understanding quantitatively. Experiments have been conducted at the Trident laser facility and the LULI (Laboratoire pour l'Utilisation des Lasers Intenses) to investigate stimulated Raman scattering near the threshold of the instability using 527 nm and 1059 nm laser light respectively with 1.5-3.0 ps pulses. In both experiments, the interaction beam was focused into a pre-ionized He gas-jet plasma. Measurements of the reflectivity as a function of intensity and k{lambda}{sub D} were completed at the Trident laser facility. At LULI, a 300 fs Thomson scattering probe is used to directly measure the density fluctuations of the driven electron plasma and ion acoustic waves. Work is currently underway comparing the results of the experiments with simulations using the VPIC [K. J. Bowers, et at., Phys. Plasmas, 15 055703 (2008)] particle-in-cell code. Details of the experimental results are presented in this manuscript.

  7. Critical Parameters for Turbulent Transport in the SOL: Mechanism for the L-H Transition and its impact on the H-mode Power Threshold and Density Limit in ITER

    E-Print Network [OSTI]

    Critical Parameters for Turbulent Transport in the SOL: Mechanism for the L-H Transition and its impact on the H-mode Power Threshold and Density Limit in ITER

  8. Hearing Conservation Program November 3, 2011

    E-Print Network [OSTI]

    Industrial Hygiene Association, Noise and Hearing Conservation, AIHA 1986 4.4.2. United States Air Force of Governmental Industrial Hygienists Threshold Limit Value (ACGIH TLV) 4.4. Pertinent Guidance: 4.4.1. American

  9. Limits on Low-Mass WIMP Dark Matter with an Ultra-Low-Energy Germanium Detector at 220 eV Threshold

    E-Print Network [OSTI]

    Shin-Ted Lin; H. T. Wong; for the TEXONO Collaboration

    2008-10-20T23:59:59.000Z

    An energy threshold of (220$\\pm$10) eV was achieved at an efficiency of 50% with a four-channel ultra-low-energy germanium detector each with an active mass of 5 g\\cite{wimppaper}. This provides a unique probe to WIMP dark matter with mass below 10 GeV. With low background data taken at the Kuo-Sheng Laboratory, constraints on WIMPs in the galactic halo were derived. Both spin-independent WIMP-nucleon and spin-dependent WIMP-neutron bounds improve over previous results for WIMP mass between 3$-$6 GeV. These results, together with those on spin-dependent couplings, will be presented. Sensitivities for full-scale experiments were projected. This detector technique makes the unexplored sub-keV energy window accessible for new neutrino and dark matter experiments.

  10. Safety-oriented Resilience Evaluation in Chemical Processes

    E-Print Network [OSTI]

    Dinh, Linh Thi Thuy

    2012-02-14T23:59:59.000Z

    relative gain array RI random consistency index SVA singular value analysis TLV threshold limit value UEL upper explosion limit vii Variables ai weighting factors C safety criteria limits d design parameter D design limits eij... APPENDIX D .......................................................................................................... 152 APPENDIX E ........................................................................................................... 154 VITA...

  11. Top Threshold Physics

    E-Print Network [OSTI]

    Andre H. Hoang

    2006-04-21T23:59:59.000Z

    Running a future Linear Collider at the top pair threshold allows for precise measurements of the mass, the widths and the couplings of the top quark. I give a nontechnical review on recent theoretical developments and the theory status in top threshold physics concerning QCD corrections and top quark finite lifetime and electroweak effects. I also discuss threshold physics in the context of measurements of the top Yukawa coupling from $e^+e^-\\to t\\bar t H$ and of squark pair production.

  12. Methods for threshold determination in multiplexed assays

    DOE Patents [OSTI]

    Tammero, Lance F. Bentley; Dzenitis, John M; Hindson, Benjamin J

    2014-06-24T23:59:59.000Z

    Methods for determination of threshold values of signatures comprised in an assay are described. Each signature enables detection of a target. The methods determine a probability density function of negative samples and a corresponding false positive rate curve. A false positive criterion is established and a threshold for that signature is determined as a point at which the false positive rate curve intersects the false positive criterion. A method for quantitative analysis and interpretation of assay results together with a method for determination of a desired limit of detection of a signature in an assay are also described.

  13. Threshold for dissipative fission

    SciTech Connect (OSTI)

    Thoennessen, M.; Bertsch, G.F. (National Superconducting Cyclotron Laboratory and Department of Physics Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States) Department of Physics, FM-15, University of Washington, Seattle, Washington 98105 (United States))

    1993-12-27T23:59:59.000Z

    We examine the empirical domain of validity of statistical theory, as applied to fission data on prefission neutron, charged particle, and [gamma]-ray multiplicities. Systematics are found in the threshold excitation energy for the appearance of nonstatistical fission. From the data on systems with not too high fissility,, the relevant phenomenological parameter is the ratio of the threshold temperature [ital T][sub thresh] to the (temperature dependent) fission barrier height [ital E][sub bar([ital T])]. The statistical model reproduces the data for [ital T][sub thresh]/[ital E][sub bar([ital T])[lt]0.26][plus minus]0.05 but underpredicts the multiplicities at higher [ital T][sub thresh]/[ital E][sub bar([ital T])] independent of mass and fissility of the systems.

  14. Threshold voltage extraction circuit

    E-Print Network [OSTI]

    Hoon, Siew Kuok

    2000-01-01T23:59:59.000Z

    to that of the saturation method. However, instead of fixing Vos ? Vos, the drain current is measured as a function of Vos while Vns is fixed at a constant low voltage of 100mV to ensure operation in the linear MOSFET region. Neglecting channel length modulation effect... transistors are layout next to the DUT of the NMOS and PMOS Vr extraction circuits respectively for extraction of Vr via graphical means. GRAPHICAL METHOD OF THE THRESHOLD-VOLTAGE MEASUREMENT Using the graphical method, the characteristics of 4n versus Vos...

  15. Considerations when applying thresholds to

    E-Print Network [OSTI]

    Wind erosion thresholds are crossed as gap sizes increase due to grass mortality (often, but not always (wind erosion) or property (gap size) Resilience begins to decline ­ increasing probability (wind erosion) or property (gap size) "THRESHOLD" #12;Probabilityofautogenicrecovery Status of key

  16. Resilience, Triggers, Feedbacks and Thresholds

    E-Print Network [OSTI]

    High Low Energy capture efficiency Nutrient retention efficiencyResource flows captured by organic Australia's Rangelands. CSIRO, Australia. Pp. 158. #12;Ecological Thresholds ``Thresholds are boundaries-functional Recovery requires vegetation manipulation Water capture efficiencyHigh Low High Low High Low Moderate High

  17. STEPLENGTH THRESHOLDS FOR INVARIANCE PRESERVING ...

    E-Print Network [OSTI]

    2014-06-25T23:59:59.000Z

    ods, i.e., the coefficient matrix of the discrete system is derived from the Taylor expansion of eAc?t, we present an algorithm to derive a valid steplength threshold.

  18. Summing tree graphs at threshold

    SciTech Connect (OSTI)

    Brown, L.S. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1992-11-15T23:59:59.000Z

    The solution of the classical field equation generates the sum of all tree graphs. We show that the classical equation reduces to an easily solved ordinary differential equation for certain multiparticle threshold amplitudes and compute these amplitudes.

  19. Fractal Superconductivity near Localization Threshold

    E-Print Network [OSTI]

    Fominov, Yakov

    Fractal Superconductivity near Localization Threshold Mikhail Feigel'man Landau Institute, Moscow-electron states are extended but fractal and populate small fraction of the whole volume How BCS theory should be modified to account for eigenstates fractality ? #12;Mean-Field Eq. for Tc #12;#12;3D Anderson model: = 0

  20. MACHINE MONITORING USING PROBABILITY THRESHOLDS

    E-Print Network [OSTI]

    Pollock, Stephen

    MACHINE MONITORING USING PROBABILITY THRESHOLDS AND SYSTEM OPERATING CHARACTERISTICS Stephen M and Jeffrey M. Alden G.M. R&D Center Warren, MI 48090 IOE Tech Report 95-14 #12;1. Introduction We a discrete-part production machine, with the objective of effectively determining when to shut the machine

  1. Reduced lasing threshold from organic dye microcavities

    E-Print Network [OSTI]

    Akselrod, G. M.

    We demonstrate an unexpected tenfold reduction in the lasing threshold of an organic vertical microcavity under subpicosecond optical excitation. In contrast to conventional theory of lasing, we find that the lasing threshold ...

  2. Compositional threshold for Nuclear Waste Glass Durability

    SciTech Connect (OSTI)

    Kruger, Albert A. [Pacific Northwest National Lab., Richland, WA (United States); Farooqi, Rahmatullah [Pohang Univ. of Science and Technology, (Korea, Republic of); Hrma, Pavel R. [Pacific Northwest National Lab., Richland, WA (United States), Pohang Univ. of Science and Technology, (Korea, Republic of)

    2013-04-24T23:59:59.000Z

    Within the composition space of glasses, a distinct threshold appears to exist that separates "good" glasses, i.e., those which are sufficiently durable, from "bad" glasses of a low durability. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region.

  3. Occupational Exposure to Benzene from Painting with Epoxy and Other High Performance Coatings

    SciTech Connect (OSTI)

    JAHN, STEVEN

    2005-04-20T23:59:59.000Z

    Following the discovery of trace benzene in paint products, an assessment was needed to determine potential for benzene exposures to exceed the established ACGIH Threshold Limit Value (TLV) during painting operations. Sample data was collected by area industrial hygienists for benzene during routine maintenance and construction activities at Savannah River Site. A set of available data from the IH database, Sentry, was analyzed to provide guidance to the industrial hygiene staff and draw conclusions on the exposure potential during typical painting operations.

  4. Optimization Online - Sequential Threshold Control in Descent ...

    E-Print Network [OSTI]

    Igor Konnov

    2014-11-21T23:59:59.000Z

    Nov 21, 2014 ... Sequential Threshold Control in Descent Splitting Methods for Decomposable Optimization Problems. Igor Konnov(konn-igor ***at*** ya.ru).

  5. Molecular dynamics simulation of threshold displacement energies...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    experimental estimates in ceramics. Citation: Moreira PA, R Devanathan, J Yu, and WJ Weber.2009."Molecular dynamics simulation of threshold displacement energies in...

  6. Wind-Blown Sand: Threshold of Motion

    E-Print Network [OSTI]

    Swann, Christy Michelle

    2014-11-12T23:59:59.000Z

    ....................................................................................... 43 13 Bedload trap designed for this study .................................................................................. 45 14 Schematic of internal adjustable chimney adjusted to the height of the surface... predicting the threshold for wind-blown sand in natural environments are rooted in the original wind tunnel work of Bagnold (1936). He introduced an empirically-calibrated model of the threshold using shear velocity, 𝑢?: a height independent variable...

  7. Hierarchical Threshold Secret Sharing Tamir Tassa

    E-Print Network [OSTI]

    Beimel, Amos

    Hierarchical Threshold Secret Sharing Tamir Tassa Abstract We consider the problem of threshold secret sharing in groups with hierarchical structure. In such settings, the secret is shared among and the presence of higher level participants is imperative to allow the recovery of the common secret. Even though

  8. Hierarchical Threshold Secret Sharing Tamir Tassa #

    E-Print Network [OSTI]

    Tassa, Tamir

    Hierarchical Threshold Secret Sharing Tamir Tassa # December 6, 2006 Abstract We consider the problem of threshold secret sharing in groups with hierarchical structure. In such settings, the secret of the common secret. Even though secret sharing in hierarchical groups has been studied extensively in the past

  9. Hierarchical Threshold Secret Sharing Tamir Tassa

    E-Print Network [OSTI]

    Tassa, Tamir

    Hierarchical Threshold Secret Sharing Tamir Tassa Division of Computer Science, The Open University tassa@yahoo.com Abstract. We consider the problem of threshold secret sharing in groups with hierarchical structure. In such settings, the secret is shared among a group of participants

  10. Hierarchical Threshold Secret Sharing Tamir Tassa

    E-Print Network [OSTI]

    Tassa, Tamir

    Hierarchical Threshold Secret Sharing Tamir Tassa December 6, 2006 Abstract We consider the problem of threshold secret sharing in groups with hierarchical structure. In such settings, the secret is shared among and the presence of higher level participants is imperative to allow the recovery of the common secret. Even though

  11. Simulating Threshold Circuits by Majority Circuits \\Lambda

    E-Print Network [OSTI]

    Karpinski, Marek

    Simulating Threshold Circuits by Majority Circuits \\Lambda Mikael Goldmann y Numerical Analysis, and Kailath proved super­linear lower bounds on the number of wires in constant­depth majority circuits­size depth 2 majority circuit. In general we show that a polynomial­size, depth­ d threshold circuit can

  12. Beyond Kennicott : perceptions of threshold, conceptions of distance

    E-Print Network [OSTI]

    Bull, Steven Keith

    1997-01-01T23:59:59.000Z

    Threshold: The thesis explores descriptions of threshold. Threshold is not an ordinary space. It relates to the here and the there and the understanding of distance. It is the phenomena of distance, no matter how close ...

  13. Threshold Effects Beyond the Standard Model

    E-Print Network [OSTI]

    Tomasz R. Taylor

    2006-12-12T23:59:59.000Z

    In this contribution to the Festschrift celebrating Gabriele Veneziano on his 65th birthday, I discuss the threshold effects of extra dimensions and their applications to physics beyond the standard model, focusing on superstring theory.

  14. A threshold type Cerenkov radiation detector

    E-Print Network [OSTI]

    Winningham, John David

    1965-01-01T23:59:59.000Z

    A THRESHOLD TYPE CERENKOV RADIATION DETECTOR A Thesis By JOHN DAVID WINNINGHAN Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree of NASTER OF SCIENCE May, 1965 Ha/or Sub...)ect: Physics A THRESHOLD TYPE CERENKOV RADIATION DETECTOR A Thesis By JOHN DAVID WINNINGHAM Approved as to style and content by: 3 v (Chairman of Committee) j' ) Heqd of Department) (Member) (Member) May, 1965 i. '. 11648 ACKNOWLEDGEIKNTS I wish...

  15. Fractal Threshold Behavior in Vacuum Gravitational Collapse

    E-Print Network [OSTI]

    Sebastian J. Szybka; Tadeusz Chmaj

    2008-04-02T23:59:59.000Z

    We present the numerical evidence for fractal threshold behavior in the five dimensional vacuum Einstein equations satisfying the cohomogeneity-two triaxial Bianchi type-IX ansatz. In other words, we show that a flip of the wings of a butterfly may influence the process of the black hole formation.

  16. Hard Thresholding Pursuit Algorithms: Number of Iterations

    E-Print Network [OSTI]

    Hitczenko, Pawel

    algorithms do provide alternative methods. We consider here the hard thresholding pursuit (HTP) algorithm [6 us now recall that (HTP) consists in constructing a sequence (xn) of s-sparse vectors, starting absolute entries of xn-1 + A (y - Axn-1 ),(HTP1) xn := argmin{ y - Az 2, supp(z) Sn },(HTP2) until

  17. Multiple Sclerosis Luminance Threshold and Measurements

    E-Print Network [OSTI]

    Foster, David H.

    Multiple Sclerosis Luminance Threshold and Measurements of Temporal Characteristics of Vision Definite MS + 6/9 - + + 7/50/F Recurrent ON + 6/6 + - + 8/47/F Definite MS + 6/6 + + + · Luminance to te t the temporal properties of vi Ion were equalized with respect to Individual luminance thresh

  18. Reliability of underwater hearing thresholds in pinnipeds

    E-Print Network [OSTI]

    Reichmuth, Colleen

    Reliability of underwater hearing thresholds in pinnipeds Brandon L. Southall Long Marine and certain testing parameters (e.g., equipment and research personnel), measured underwater hearing (0.2­6.4 kHz). These data address the reliability of acoustic signal detection measurements over time

  19. Threshold photodetachment spectroscopy of negative ions

    SciTech Connect (OSTI)

    Kitsopoulos, T.N.

    1991-12-01T23:59:59.000Z

    This thesis is concerned with the development and application of high resolution threshold photodetachment spectroscopy of negative ions. Chapter I deals with the principles of our photodetachment technique, and in chapter II a detailed description of the apparatus is presented. The threshold photodetachment spectra of I{sup {minus}}, and SH{sup {minus}}, presented in the last sections of chapter II, indicated that a resolution of 3 cm{sup {minus}1} can be achieved using our technique. In chapter III the threshold photodetachment spectroscopy study of the transition state region of I + HI and I + Di reactions is discussed. Our technique probes the transition state region directly, and the results of our study are the first unambiguous observations of reactive resonances in a chemical reaction. Chapters IV, V and VI are concerned with the spectroscopy of small silicon and carbon clusters. From our spectra we were able to assign electronic state energies and vibrational frequencies for the low lying electronics states of Si{sub n} (n=2,3,4), C{sub 5} and their corresponding anions.

  20. Optimization Online - A Counterexample to “Threshold Boolean form ...

    E-Print Network [OSTI]

    James Luedtke

    2015-01-02T23:59:59.000Z

    Jan 2, 2015 ... ... to “Threshold Boolean form for joint probabilistic constraints with random technology matrix” ... the Mathematical Optmization Society.

  1. Fault-Tolerant Thresholds for Encoded Ancillae with Homogeneous Errors

    E-Print Network [OSTI]

    Bryan Eastin

    2006-11-14T23:59:59.000Z

    I describe a procedure for calculating thresholds for quantum computation as a function of error model given the availability of ancillae prepared in logical states with independent, identically distributed errors. The thresholds are determined via a simple counting argument performed on a single qubit of an infinitely large CSS code. I give concrete examples of thresholds thus achievable for both Steane and Knill style fault-tolerant implementations and investigate their relation to threshold estimates in the literature.

  2. On the measurement of laser-induced plasma breakdown thresholds

    SciTech Connect (OSTI)

    Brieschenk, Stefan [Centre for Hypersonics, The University of Queensland, Brisbane 4072 (Australia)] [Centre for Hypersonics, The University of Queensland, Brisbane 4072 (Australia); Kleine, Harald; O'Byrne, Sean [The University of New South Wales Canberra, The Australian Defence Force Academy, Canberra 2600 (Australia)] [The University of New South Wales Canberra, The Australian Defence Force Academy, Canberra 2600 (Australia)

    2013-09-07T23:59:59.000Z

    The breakdown threshold of a gas exposed to intense laser-radiation is a function of gas and laser properties. Breakdown thresholds reported in the literature often vary greatly and these differences can partially be traced back to the method that is typically used to determine breakdown thresholds. This paper discusses the traditional method used to determine breakdown thresholds and the potential errors that can arise using this approach, and presents an alternative method which can yield more accurate data especially when determining breakdown thresholds as functions of gas pressure.

  3. The AMS-01 Aerogel Threshold Cherenkov counter

    E-Print Network [OSTI]

    D. Barancourt; F. Barao; G. Barbier; G. Barreira; M. Buenerd; G. Castellini; E. Choumilov; J. Favier; N. Fouque; A. Gougas; V. Hermel; R. Kossakowski; G. Laborie; G. Laurenti; S. -C. Lee; F. Mayet; B. Meillon; Y. -T. Oyang; V. Plyaskin; V. Pojidaev; C. Rossin; D. Santos; F. Vezzu; J. P. Vialle

    2000-10-12T23:59:59.000Z

    The Alpha Magnetic Spectrometer in a precursor version (AMS-01), was flown in June 1998 on a 51.6 degrees orbit and at altitudes ranging between 320 and 390 km, on board of the space shuttle Discovery (flight STS-91). AMS-01 included an Aerogel Threshold Cherenkov counter (ATC) to separate antiprotons from electrons and positrons from protons, for momenta below 3.5 GeV/c. This paper presents a description of the ATC counter and reports on its performances during the flight STS-91.

  4. Quark mass thresholds in QCD thermodynamics

    E-Print Network [OSTI]

    M. Laine; Y. Schroder

    2006-05-05T23:59:59.000Z

    We discuss radiative corrections to how quark mass thresholds are crossed, as a function of the temperature, in basic thermodynamic observables such as the pressure, the energy and entropy densities, and the heat capacity of high temperature QCD. The indication from leading order that the charm quark plays a visible role at surprisingly low temperatures, is confirmed. We also sketch a way to obtain phenomenological estimates relevant for generic expansion rate computations at temperatures between the QCD and electroweak scales, pointing out where improvements over the current knowledge are particularly welcome.

  5. Threshold 21 Model | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries PvtStratosolarTharaldson Ethanol LLCEnergyoThornwood, NewThreshold 21 Model Jump

  6. Threshold shift and above-threshold multiphoton ionization of atomic hydrogen in intense laser fields

    E-Print Network [OSTI]

    Chu, Shih-I; Cooper, J.

    1985-11-01T23:59:59.000Z

    , while hE, =e F /4m co~ = e F s/2m' is the continuum threshold upshift. 1 e 2@2 4 Itt CO and the threshold shift as (3) 0.28 0.01 0.025 0.05 0.075 —1.185(—2) —6.732( —2) —2.036( —1) —3.306( —1) 1.735{—2) 1.085( —1) 4.339(—1) 9.762( —1) 2.92( —2) 1.76( —1...

  7. Superlinear threshold detectors in quantum cryptography

    SciTech Connect (OSTI)

    Lydersen, Lars; Maroey, Oystein; Skaar, Johannes; Makarov, Vadim [Department of Electronics and Telecommunications, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); University Graduate Center, NO-2027 Kjeller (Norway); Jain, Nitin; Wittmann, Christoffer; Marquardt, Christoph; Leuchs, Gerd [Max Planck Institute for the Science of Light, Guenther-Scharowsky-Strasse 1/Bau 24, DE-91058 Erlangen (Germany); Institut fuer Optik, Information und Photonik, University of Erlangen-Nuremberg, Staudtstrasse 7/B2, DE-91058 Erlangen (Germany)

    2011-09-15T23:59:59.000Z

    We introduce the concept of a superlinear threshold detector, a detector that has a higher probability to detect multiple photons if it receives them simultaneously rather than at separate times. Highly superlinear threshold detectors in quantum key distribution systems allow eavesdropping the full secret key without being revealed. Here, we generalize the detector control attack, and analyze how it performs against quantum key distribution systems with moderately superlinear detectors. We quantify the superlinearity in superconducting single-photon detectors based on earlier published data, and gated avalanche photodiode detectors based on our own measurements. The analysis shows that quantum key distribution systems using detector(s) of either type can be vulnerable to eavesdropping. The avalanche photodiode detector becomes superlinear toward the end of the gate. For systems expecting substantial loss, or for systems not monitoring loss, this would allow eavesdropping using trigger pulses containing less than 120 photons per pulse. Such an attack would be virtually impossible to catch with an optical power meter at the receiver entrance.

  8. Radioactive sealed sources: Reasonable accountability, exemption, and licensing activity thresholds -- A technical basis

    SciTech Connect (OSTI)

    Lee, D.W. [Los Alamos National Lab., NM (United States); Shingleton, K.L. [Lawrence Livermore National Lab., CA (United States)

    1996-07-01T23:59:59.000Z

    Perhaps owing to their small size and portability, some radiation accidents/incidents have involved radioactive sealed sources (RSSs). As a result, programs for the control and accountability of RSSs have come to be recommended and emplaced that essentially require RSSs to be controlled in a manner different from bulk, unsealed radioactive material. Crucially determining the total number of RSSs for which manpower-intensive radiation protection surveillance is provided is the individual RSS activity above which such surveillance is required and below which such effort is not considered cost effective. Individual RSS activity thresholds are typically determined through scenarios which impart a chosen internal or external limiting dose to Reference Man under specified exposure conditions. The resultant RSS threshold activity levels have meaning commensurate with the assumed scenario exposure parameters, i.e., if they are realistic and technically based. A review of how the Department of Energy (DOE), the International Atomic Energy Agency (IAEA), and the Nuclear Regulatory Commission (NRC) have determined their respective accountability, exemption, and licensing threshold activity values is provided. Finally, a fully explained method using references readily available to practicing health physicists is developed using realistic, technically-based calculation parameters by which RSS threshold activities may be locally generated.

  9. The (Unstable) Threshold of Black Hole Formation

    E-Print Network [OSTI]

    M. W. Choptuik

    1998-03-23T23:59:59.000Z

    In recent years it has become apparent that intriguing phenomenology exists at the threshold of black hole formation in a large class of general relativistic collapse models. This phenomenology, which includes scaling, self-similarity and universality, is largely analogous to statistical mechanical critical behaviour, a fact which was first noted empirically, and subsequently clarified by perturbative calculations which borrow on ideas and techniques from dynamical systems theory and renormalization group theory. This contribution, which closely parallels my talk at the conference, consists of an overview of the considerable ``zoo''' of critical solutions which have been discovered thus far, along with a brief discussion of how we currently understand the nature of these solutions from the point of view of perturbation theory.

  10. Optical ranked-order filtering using threshold decomposition

    DOE Patents [OSTI]

    Allebach, J.P.; Ochoa, E.; Sweeney, D.W.

    1987-10-09T23:59:59.000Z

    A hybrid optical/electronic system performs median filtering and related ranked-order operations using threshold decomposition to encode the image. Threshold decomposition transforms the nonlinear neighborhood ranking operation into a linear space-invariant filtering step followed by a point-to-point threshold comparison step. Spatial multiplexing allows parallel processing of all the threshold components as well as recombination by a second linear, space-invariant filtering step. An incoherent optical correlation system performs the linear filtering, using a magneto-optic spatial light modulator as the input device and a computer-generated hologram in the filter plane. Thresholding is done electronically. By adjusting the value of the threshold, the same architecture is used to perform median, minimum, and maximum filtering of images. A totally optical system is also disclosed. 3 figs.

  11. Optical ranked-order filtering using threshold decomposition

    DOE Patents [OSTI]

    Allebach, Jan P. (West Lafayette, IN); Ochoa, Ellen (Pleasanton, CA); Sweeney, Donald W. (Alamo, CA)

    1990-01-01T23:59:59.000Z

    A hybrid optical/electronic system performs median filtering and related ranked-order operations using threshold decomposition to encode the image. Threshold decomposition transforms the nonlinear neighborhood ranking operation into a linear space-invariant filtering step followed by a point-to-point threshold comparison step. Spatial multiplexing allows parallel processing of all the threshold components as well as recombination by a second linear, space-invariant filtering step. An incoherent optical correlation system performs the linear filtering, using a magneto-optic spatial light modulator as the input device and a computer-generated hologram in the filter plane. Thresholding is done electronically. By adjusting the value of the threshold, the same architecture is used to perform median, minimum, and maximum filtering of images. A totally optical system is also disclosed.

  12. anisotropy instability thresholds: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    these fluctuations are enhanced along the temperature anisotropy thresholds of the mirror, proton oblique firehose, and ion cyclotron instabilities. In addition, the measured...

  13. Sequential Threshold Control in Descent Splitting Methods for ...

    E-Print Network [OSTI]

    2014-11-21T23:59:59.000Z

    Nov 5, 2014 ... coordinate-wise steps together with a special threshold control. ... the computational process and leads to the (forward-backward) splitting ...

  14. Quantum Limits and Robustness of Nonlinear Intracavity Absorption Spectroscopy

    E-Print Network [OSTI]

    John K. Stockton; Ari K. Tuchman

    2008-10-23T23:59:59.000Z

    We investigate the limits of intracavity absorption spectroscopy with nonlinear media. Using a common theoretical framework, we compare the detection of a trace gas within an undriven cavity with gain near and above threshold, a driven cavity with gain kept just below threshold, and a cavity driven close to the saturation point of a saturable absorber. These phase-transition-based metrology methods are typically quantum-limited by spontaneous emission, and we compare them to the empty cavity shotnoise-limited case. Although the fundamental limits achievable with nonlinear media do not surpass the empty cavity limits, we show that nonlinear methods are more robust against certain technical noise models. This recognition may have applications in spectrometer design for devices operating in non-ideal field environments.

  15. Process Limits on Euclid

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Process Limits Process Limits Limit Hard Soft core file size (blocks) 0 unlimited data seg size (kbytes) unlimited unlimited scheduling priority 0 0 file size (blocks) unlimited...

  16. Stability threshold of ion temperature gradient driven mode in reversed field pinch plasmas

    SciTech Connect (OSTI)

    Guo, S. C. [Consorzio RFX, Associazione Euratom-ENEA sulla fusione, Corso Stati Uniti 4, Padova 35127 (Italy)

    2008-12-15T23:59:59.000Z

    For the first time in the reversed field pinch (RFP) configuration, the stability threshold of the ion temperature gradient driven (ITG) mode is studied by linear gyrokinetic theory. In comparison with tokamaks, the RFP configuration has a shorter connection length and stronger magnetic curvature drift. These effects result in a stronger instability driving mechanism and a larger growth rate in the fluid limit. However, the kinetic theory shows that the temperature slopes required for the excitation of ITG instability are much steeper than the tokamak ones. This is because the effect of Landau damping also becomes stronger due to the shorter connection length, which is dominant and ultimately determines the stability threshold. The required temperature slope for the instability may only be found in the very edge of the plasma and/or near the border of the dominant magnetic island during the quasi-single helicity state of discharge.

  17. A Threshold Autoregressive Model for Wholesale Electricity Prices

    E-Print Network [OSTI]

    A Threshold Autoregressive Model for Wholesale Electricity Prices B. Ricky Rambharat, Department the price of wholesale electricity soared to an unprecedented level of $7,500 per MwH (see [14-order threshold autoregressive model (TAR(1)) for wholesale electricity prices. (For discussion of TAR models, see

  18. Wavelet thresholding using generalized cross Maarten Jansen, Adhemar Bultheel

    E-Print Network [OSTI]

    Jansen, Maarten

    Wavelet thresholding using generalized cross validation Maarten Jansen, Adhemar Bultheel October 1997 Abstract De­noising algorithms based on wavelet thresholding replace small wavelet coefficients,this method assumes uncorrelated noise and or­ thogonal wavelet transforms. It turns out that extension

  19. Characterizing Ideal Weighted Threshold Secret Amos Beimel1

    E-Print Network [OSTI]

    Beimel, Amos

    Characterizing Ideal Weighted Threshold Secret Sharing Amos Beimel1 , Tamir Tassa1,2 , and Enav Science, The Open University, Ra'anana, Israel. Abstract. Weighted threshold secret sharing was introduced by Shamir in his seminal work on secret sharing. In such settings, there is a set of users where each user

  20. A threshold Cherenkov detector for K separation using silica aerogel

    E-Print Network [OSTI]

    Magiera, Andrzej

    A threshold Cherenkov detector for Kþ =pþ separation using silica aerogel R. Siudak a,b , A August 2008 Keywords: Threshold Cherenkov detector Silica aerogel Reaction pp ! Kþ ðLp� Kþ =pþ separation in the focal plane of a magnetic spectrograph. Silica aerogel with refractive index of n ¼ 1:05 is applied

  1. d Original Contribution IDENTIFYING THE INERTIAL CAVITATION THRESHOLD AND SKULL

    E-Print Network [OSTI]

    Konofagou, Elisa E.

    d Original Contribution IDENTIFYING THE INERTIAL CAVITATION THRESHOLD AND SKULL EFFECTS IN AVESSEL unknown. To investigate the pressure threshold for inertial cavitation of pre- formed microbubbles during sonication, passive cavitation detection in conjunction with B-mode imaging was used. A cerebral vessel

  2. Advantages and Limitations of the RICH Technique for Particle Identification

    SciTech Connect (OSTI)

    Ratcliff, Blair N.; /SLAC

    2011-11-07T23:59:59.000Z

    The ring imaging Cherenkov (RICH) technique for hadronic particle identification (PID) is described. The advantages and limitations of RICH PID counters are compared with those of other classic PID techniques, such as threshold Cherenkov counters, ionization loss (dE/dx) in tracking devices, and time of flight (TOF) detectors.

  3. A Low-threshold Analysis of CDMS Shallow-site Data

    SciTech Connect (OSTI)

    Akerib, D.S.; /Case Western Reserve U.; Attisha, M.J.; /Brown U.; Baudis, L.; /Zurich-Irchel U.; Bauer, D.A.; /Fermilab; Bolozdynya, A.I.; /Case Western Reserve U.; Brink, P.L.; /SLAC; Bunker, R.; /UC, Santa Barbara; Cabrera, B.; /Stanford U., Phys. Dept.; Caldwell, D.O.; /UC, Santa Barbara; Chang, C.L.; /Stanford U., Phys. Dept.; Clarke, R.M.; /Stanford U., Phys. Dept.; Cooley, J.; /Southern Methodist U.; Crisler, M.B.; /Fermilab; Cushman, P.; /Minnesota U.; DeJongh, F.; /Fermilab; Dixon, R.; /Fermilab; Driscoll, D.D.; /Case Western Reserve U.; Filippini, J.; /Caltech; Funkhouser, S.; /UC, Berkeley; Gaitskell, R.J.; /Brown U.; Golwala, S.R.; /Caltech /Fermilab /Fermilab /Colorado U., Denver /Case Western Reserve U. /Texas A-M /Minnesota U. /UC, Berkeley /UC, Berkeley /Caltech /Stanford U., Phys. Dept. /UC, Santa Barbara /Stanford U., Phys. Dept. /Minnesota U. /Queen's U., Kingston /Minnesota U. /St. Olaf Coll. /Florida U. /LBL, Berkeley /UC, Berkeley /Texas A-M /UC, Santa Barbara /Syracuse U. /UC, Berkeley /Princeton U. /Case Western Reserve U. /Stanford U., Phys. Dept. /UC, Santa Barbara /Fermilab /Santa Clara U.

    2012-06-04T23:59:59.000Z

    Data taken during the final shallow-site run of the first tower of the Cryogenic Dark Matter Search (CDMS II) detectors have been reanalyzed with improved sensitivity to small energy depositions. Four {approx}224 g germanium and two {approx}105 g silicon detectors were operated at the Stanford Underground Facility (SUF) between December 2001 and June 2002, yielding 118 live days of raw exposure. Three of the germanium and both silicon detectors were analyzed with a new low-threshold technique, making it possible to lower the germanium and silicon analysis thresholds down to the actual trigger thresholds of {approx}1 and {approx}2 keV, respectively. Limits on the spin-independent cross section for weakly interacting massive particles (WIMPs) to elastically scatter from nuclei based on these data exclude interesting parameter space for WIMPs with masses below 9 GeV/c{sup 2}. Under standard halo assumptions, these data partially exclude parameter space favored by interpretations of the DAMA/LIBRA and CoGeNT experiments data as WIMP signals, and exclude new parameter space for WIMP masses between 3 and 4 GeV/c{sup 2}.

  4. A low-threshold analysis of CDMS shallow-site data

    SciTech Connect (OSTI)

    Akerib, D.S.; /Case Western Reserve U.; Attisha, M.J.; /Brown U.; Baudis, L.; /Zurich-Irchel U.; Bauer, D.A.; /Fermilab; Bolozdynya, A.I.; /Case Western Reserve U.; Brink, P.L.; /SLAC; Bunker, R.; /UC, Santa Barbara; Cabrera, B.; /Stanford U., Phys. Dept.; Caldwell, D.O.; /UC, Santa Barbara; Chang, C.L.; /Stanford U., Phys. Dept.; Clarke, R.M.; /Stanford U., Phys. Dept. /Southern Methodist U.

    2010-10-01T23:59:59.000Z

    Data taken during the final shallow-site run of the first tower of the Cryogenic Dark Matter Search (CDMS II) detectors have been reanalyzed with improved sensitivity to small energy depositions. Four {approx}224 g germanium and two {approx}105 g silicon detectors were operated at the Stanford Underground Facility (SUF) between December 2001 and June 2002, yielding 118 live days of raw exposure. Three of the germanium and both silicon detectors were analyzed with a new low-threshold technique, making it possible to lower the germanium and silicon analysis thresholds down to the actual trigger thresholds of {approx}1 keV and {approx}2 keV, respectively. Limits on the spin-independent cross section for weakly interacting massive particles (WIMPs) to elastically scatter from nuclei based on these data exclude interesting parameter space for WIMPs with masses below 9 GeV/c{sup 2}. Under standard halo assumptions, these data partially exclude parameter space favored by interpretations of the DAMA/LIBRA and CoGeNT experiments data as WIMP signals, and exclude new parameter space for WIMP masses between 3 GeV/c{sup 2} and 4 GeV/c{sup 2}.

  5. On the Behavior of the Threshold Operator for Bandlimited Functions

    E-Print Network [OSTI]

    Boche, Holger

    One interesting question is how the good local approximation behavior of the Shannon sampling series for the Paley–Wiener space PW[1 over ?] is affected if the samples are disturbed by the non-linear threshold operator. ...

  6. A Threshold Autoregressive Model for Wholesale Electricity Prices

    E-Print Network [OSTI]

    A Threshold Autoregressive Model for Wholesale Electricity Prices B. Ricky Rambharat Carnegie of wholesale electricity soared to an unprecedented $7,500 per megawatt-hour (MwH) (see FERC, 1998). Models

  7. Applying thresholds to forecast potential biodiversity loss from human development

    E-Print Network [OSTI]

    Hilderbrand, Robert H.

    thresholds to projected increases in residential development in the Middle Patuxent River watershed by 2030 in the Potapsco River watershed of Maryland could result in the loss of nearly 60% of the benthic

  8. Essays on Voluntary Contribution with Private Information and Threshold Uncertainty

    E-Print Network [OSTI]

    Peng, Hui-Chun

    2014-07-08T23:59:59.000Z

    This dissertation concerns individual voluntary contributions in the subscription game with three important model considerations: private information on public good valuations, threshold uncertainty and the timing of the contribution — simultaneous...

  9. Submilliampere threshold current pseudomorphic InGaAs/AlGaAs buried-heterostructure quantum well lasers grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Eng, L.E.; Chen, T.R.; Sanders, S.; Zhuang, Y.H.; Zhao, B.; Yariv, A. (Department of Applied Physics, California Institute of Technology, Pasadena, California 91125 (US)); Morkoc, H. (The Coordinated Science Laboratory, University of Illinois, Urbana, Illinois 61801)

    1989-10-02T23:59:59.000Z

    We report on low threshold current strained InGaAs/AlGaAs single quantum well lasers grown by molecular beam epitaxy. Broad-area threshold current densities of 114 A/cm{sup 2} at 990 nm were measured for 1540-{mu}m-long lasers. Threshold currents of 2.4 mA at 950 nm were obtained for an uncoated buried-heterostructure device with a 2-{mu}m-wide stripe and 425-{mu}m-long cavity. With reflective coatings the best device showed 0.9 mA threshold current ({ital L}=225 {mu}m). Preliminary modulation measurements show bandwidths up to 5.5 GHz limited by the detector response.

  10. Minimum patch size thresholds of reproductive success of songbirds

    E-Print Network [OSTI]

    Butcher, Jerrod Anthony

    2009-05-15T23:59:59.000Z

    1 MINIMUM PATCH SIZE THRESHOLDS OF REPRODUCTIVE SUCCESS OF SONGBIRDS A Dissertation by JERROD ANTHONY BUTCHER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of DOCTOR OF PHILOSOPHY May 2008 Major Subject: Wildlife and Fisheries Sciences 2 MINIMUM PATCH SIZE THRESHOLDS OF REPRODUCTIVE SUCCESS OF SONGBIRDS A Dissertation by JERROD ANTHONY BUTCHER Submitted to the Office...

  11. Effect of shrink fits on threshold speeds of rotordynamic instability

    E-Print Network [OSTI]

    Mir, MD. Mofazzal Hossain

    2001-01-01T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 CHAPTER IV TEST APPARATUS . . . . 13 CHAPTER V RESULTS AND DISCUSSION . . . 17 17 30 42 42 47 5. 1 Rap Test. . 5. 2 Running Test 5. 3 Modeling and the Prcdiction of Threshold Speed of Instability.... . . . . . . . . . . . , . . . . . . . . . . . 5. 3. 1 Matching the Base Case. 5. 3. 2 Gunter's Prediction Using C, q 5. 3. 3 Modeling and Prediction of the Threshold Speed Using the XLTRC Code. . . . 51 5. 4 Prediction of the Onset Speed of Instability for a Tight Inteiference Fit...

  12. Low-energy structure of above-threshold-ionization electron spectra: Role of the Coulomb threshold effect

    E-Print Network [OSTI]

    Telnov, Dmitry A.; Chu, Shih-I

    2011-06-10T23:59:59.000Z

    Recent experimental observations of above-threshold ionization of rare gas atoms and diatomic molecules by midinfrared laser fields [C. I. Blaga et al., Nat. Phys. 5, 335 (2009); W. Quan et al., Phys. Rev. Lett. 103, 093001 ...

  13. S-wave threshold in electron attachment - observations and cross sections in CCl4 and SF6 at ultralow electron energies

    SciTech Connect (OSTI)

    Chutjian, A.; Alajajian, S.H.

    1985-05-01T23:59:59.000Z

    The threshold photoionization method was used to study low-energy electron attachment phenomena in and cross sections of CCl4 and SF6 compounds, which have applications in the design of gaseous dielectrics and diffuse discharge opening switches. Measurements were made at electron energies from below threshold to 140 meV at resolutions of 6 and 8 meV. A narrow resolution-limited structure was observed in electron attachment to CCl4 and SF6 at electron energies below 10 meV, which is attributed to the divergence of the attachment cross section in the limit epsilon, l approaches zero. The results are compared with experimental collisional-ionization results, electron-swarm unfolded cross sections, and earlier threshold photoionization data. 34 refs.

  14. Hadron mass scaling near the s-wave threshold

    E-Print Network [OSTI]

    Tetsuo Hyodo

    2014-12-02T23:59:59.000Z

    The influence of a two-hadron threshold is studied for the hadron mass scaling with respect to some quantum chromodynamics parameters. A quantum mechanical model is introduced to describe the system with a one-body bare state coupled with a single elastic two-body scattering. The general behavior of the energy of the bound and resonance state near the two-body threshold for a local potential is derived from the expansion of the Jost function around the threshold. It is shown that the same scaling holds for the nonlocal potential induced by the coupling to a bare state. In p or higher partial waves, the scaling law of the stable bound state continues across the threshold describing the real part of the resonance energy. In contrast, the leading contribution of the scaling is forbidden by the nonperturbative dynamics near the s-wave threshold. As a consequence, the bound state energy is not continuously connected to the real part of the resonance energy. This universal behavior originates in the vanishing of the field renormalization constant of the zero-energy resonance in the s wave. A proof is given for the vanishing of the field renormalization constant, together with a detailed discussion.

  15. ROBUST THRESHOLDING BASED ON WAVELETS AND THINNING ALGORITHMS FOR DEGRADED CAMERA IMAGES

    E-Print Network [OSTI]

    Dupont, Stéphane

    Copernic, 7000 Mons, Belgium ABSTRACT This paper describes a thresholding method for degraded docu- ments

  16. Threshold energy surface and Frenkel-pair resistivity for Cu

    SciTech Connect (OSTI)

    King, W.E.; Merkle, K.L.; Meshii, M.

    1982-01-01T23:59:59.000Z

    In-situ electrical resistivity damage-rate measurements in the high voltage electron microscope have been used to study electron-irradiation-induced defect production in copper single crystals at T < 10/sup 0/K. Analysis of the directional and energy dependence yields a threshold energy surface that is significantly different from those of previous investigations: two pockets of low threshold energy centered at <100> and <110> surrounded by regions of much higher threshold energy. The corresponding damage function exhibits a plateau of 0.6 Frenkel pairs. the present results imply a Frenkel pair resistivity for C of (2.75/sub -0.2//sup +0.6/) x ..cap omega..-cm.

  17. Near-threshold Photoproduction of Phi Mesons from Deuterium

    E-Print Network [OSTI]

    X. Qian; W. Chen; H. Gao; K. Hicks; K. Kramer; J. M. Laget; T. Mibe; Y. Qiang; S. Stepanyan; D. J. Tedeschi; W. Xu; K. P. Adhikari; M. Amaryan; M. Anghinolfi; J. Ball; M. Battaglieri; V. Batourine; I. Bedlinskiy; M. Bellis; A. S. Biselli; C. Bookwalter; D. Branford; W. J. Briscoe; W. K. Brooks; V. D. Burkert; S. L. Careccia; D. S. Carman; P. L. Cole; P. Collins; V. Crede; A. D'Angelo; A. Daniel; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; B. Dey; S. Dhamija; C. Djalali; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; P. Eugenio; S. Fegan; M. Y. Gabrielyan; N. Gevorgyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; W. Gohn; R. W. Gothe; L. Graham; K. A. Griffioen; M. Guidal; L. Guo; K. Hafidi; H. Hakobyan; C. Hanretty; N. Hassall; M. Holtrop; Y. Ilieva; D. G. Ireland; S. S. Jawalkar; H. S. Jo; K. Joo; D. Keller; M. Khandaker; P. Khetarpal; A. Kim; W. Kim; A. Klein; F. J. Klein; P. Konczykowski; V. Kubarovsky; S. V. Kuleshov; V. Kuznetsov; K. Livingston; D. Martinez; M. Mayer; J. McAndrew; M. E. McCracken; B. McKinnon; C. A. Meyer; K. Mikhailov; T. Mineeva; M. Mirazita; V. Mokeev; B. Moreno; K. Moriya; B. Morrison; H. Moutarde; E. Munevar; P. Nadel-Turonski; A. Ni; S. Niccolai; I. Niculescu; M. R. Niroula; M. Osipenko; A. I. Ostrovidov; R. Paremuzyan; K. Park; S. Park; S. Anefalos Pereira; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; G. Ricco; M. Ripani; B. G. Ritchie; G. Rosner; P. Rossi; F. Sabatié; M. S. Saini; C. Salgado; D. Schott; R. A. Schumacher; E. Seder; H. Seraydaryan; Y. G. Sharabian; E. S. Smith; G. D. Smith; D. I. Sober; D. Sokhan; S. S. Stepanyan; P. Stoler; I. I. Strakovsky; S. Strauch; M. Taiuti; C. E. Taylor; S. Tkachenko; M. Ungaro; B . Vernarsky; M. F. Vineyard; E. Voutier; L. B. Weinstein; D. P. Weygand; M. H. Wood; N. Zachariou; L. Zana; J. Zhang; B. Zhao; Z. W. Zhao

    2010-12-14T23:59:59.000Z

    We report the first measurement of the differential cross section on $\\phi$-meson photoproduction from deuterium near the production threshold for a proton using the CLAS detector and a tagged-photon beam in Hall B at Jefferson Lab. The measurement was carried out by a triple coincidence detection of a proton, $K^+$ and $K^-$ near the theoretical production threshold of 1.57 GeV. The extracted differential cross sections $\\frac{d\\sigma}{dt}$ for the initial photon energy from 1.65-1.75 GeV are consistent with predictions based on a quasifree mechanism. This experiment establishes a baseline for a future experimental search for an exotic $\\phi$-N bound state from heavier nuclear targets utilizing subthreshold/near-threshold production of $\\phi$ mesons.

  18. Optimal Investment Under Transaction Costs: A Threshold Rebalanced Portfolio Approach

    E-Print Network [OSTI]

    Tunc, Sait

    2012-01-01T23:59:59.000Z

    We study optimal investment in a financial market having a finite number of assets from a signal processing perspective. We investigate how an investor should distribute capital over these assets and when he should reallocate the distribution of the funds over these assets to maximize the cumulative wealth over any investment period. In particular, we introduce a portfolio selection algorithm that maximizes the expected cumulative wealth in i.i.d. two-asset discrete-time markets where the market levies proportional transaction costs in buying and selling stocks. We achieve this using "threshold rebalanced portfolios", where trading occurs only if the portfolio breaches certain thresholds. Under the assumption that the relative price sequences have log-normal distribution from the Black-Scholes model, we evaluate the expected wealth under proportional transaction costs and find the threshold rebalanced portfolio that achieves the maximal expected cumulative wealth over any investment period. Our derivations ca...

  19. Low-Threshold Surface-Passivated Photonic Crystal Nanocavity Laser

    E-Print Network [OSTI]

    Dirk Englund; Hatice Altug; Jelena Vuckovic

    2007-06-21T23:59:59.000Z

    The efficiency and operating range of a photonic crystal laser is improved by passivating the InGaAs quantum well (QW) gain medium and GaAs membrane using an (NH4)S treatment. The passivated laser shows a four-fold reduction in nonradiative surface recombination rate, resulting in a four-fold reduction in lasing threshold. A three-level carrier dynamics model explains the results and shows that lasing threshold is as much determined by surface recombination losses as by the cavity quality factor (Q). Surface passivation therefore appears crucial in operating such lasers under practical conditions.

  20. Very low threshold InGaAsP mesa laser

    SciTech Connect (OSTI)

    Chen, T.R.; Chiu, L.C.; Hasson, A.; Koren, U.; Margalit, S.; Yariv, A.; Yu, K.L.

    1983-05-01T23:59:59.000Z

    Very low threshold currents InGaAsP/InP terrace mesa (T-ME) lasers with an unpassivated surface have been fabricated on semi-insulating (SI) InP substrates. Fabrication of the lasers involves a single-step liquid phase epitaxial (LPE) growth and a simple etching process. Lasers operating in the fundamental transverse mode with threshold currents as low as 6.3 mA (for a cavity length of 250 ..mu..m) have been obtained. Comparison between the unpassivated lasers and those passivated using the mass transport technique is described.

  1. Multiphoton Double Ionization of Ar and Ne Close to Threshold

    SciTech Connect (OSTI)

    Liu Yunquan [Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany); Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871 (China); Ye Difa; Liu Jie [Center for Applied Physics and Technology, Peking University, 100084 Beijing (China); Institute of Applied Physics and Computational Mathematics, 100088 Beijing (China); Rudenko, A. [Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany); Max-Planck Advanced Study Group at CFEL, 22607 Hamburg (Germany); Tschuch, S.; Duerr, M.; Moshammer, R.; Ullrich, J. [Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany); Siegel, M.; Morgner, U. [Leibniz Universitaet Hannover, Welfengarten 1, D-30167 Hannover (Germany); Gong Qihuang [Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, Beijing 100871 (China)

    2010-04-30T23:59:59.000Z

    In kinematically complete studies we explore double ionization (DI) of Ne and Ar in the threshold regime (I>3x10{sup 13} W/cm{sup 2}) for 800 nm, 45 fs pulses. The basic differences are found in the two-electron momentum distributions - 'correlation' (CO) for Ne and 'anticorrelation' (ACO) for Ar - that can be partially explained theoretically within a 3D classical model including tunneling. Transverse electron momentum spectra provide insight into 'Coulomb focusing' and point to correlated nonclassical dynamics. Finally, DI threshold intensities, CO as well as ACO regimes are predicted for both targets.

  2. Cryostat for Ultra-low-energy Threshold Germanium Spectrometers

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Bonicalzi, Ricco; Fast, James E.; Hossbach, Todd W.; Orrell, John L.; Overman, Cory T.; VanDevender, Brent A.

    2013-04-01T23:59:59.000Z

    Abstract: This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is presented. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance.

  3. Cryostat for Ultra-low-energy Threshold Germanium Spectrometers

    E-Print Network [OSTI]

    Craig E. Aalseth; Ricco M. Bonicalzi; James E. Fast; Todd W. Hossbach; John L. Orrell; Cory T. Overman; Brent A. Vandevender

    2012-10-08T23:59:59.000Z

    This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is given. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance.

  4. Regulon inference without arbitrary thresholds: three levels of sensitivity

    SciTech Connect (OSTI)

    Dubchak, Pavel Novichkov, Elena Stavrovskaya, Dmitry Rodionov, Andrey Mironov, Inna; Rodionov, Dmitry; Mironov, Andrey; Dubchak, Inna; Novichkov, P.S.

    2010-11-15T23:59:59.000Z

    Reconstruction of transcriptional regulatory networks is one of the major challenges facing the bioinformatics community in view of constantly growing number of complete genomes. The comparative genomics approach has been successfully used for the analysis of the transcriptional regulation of many metabolic systems in various bacteria taxa. The key step in this approach is given a position weight matrix, find an optimal threshold for the search of potential binding sites in genomes. In our previous work we proposed an approach for automatic selection of TFBS score threshold coupled with inference of regulon content. In this study we developed two modifications of this approach providing two additional levels of sensitivity.

  5. Far From Threshold Buckling Analysis of Thin Films

    E-Print Network [OSTI]

    Benny Davidovitch; Robert D. Schroll; Dominic Vella; Mokhtar Adda-Bedia; Enrique Cerda

    2010-08-17T23:59:59.000Z

    Thin films buckle easily and form wrinkled states in regions of well defined size. The extent of a wrinkled region is typically assumed to reflect the zone of in-plane compressive stresses prior to buckling, but recent experiments on ultrathin sheets have shown that wrinkling patterns are significantly longer and follow different scaling laws than those predicted by standard buckling theory. Here we focus on a simple setup to show the striking differences between near-threshold buckling and the analysis of wrinkle patterns in very thin films, which are typically far from threshold.

  6. Optical Damage Threshold of Silicon for Ultrafast Infrared Pulses

    SciTech Connect (OSTI)

    Cowan, Benjamin M.; /Tech-X, Boulder /SLAC

    2007-11-28T23:59:59.000Z

    We present measurements of the optical damage threshold of crystalline silicon in air for ultrafast pulses in the near infrared. The wavelengths tested span a range from the telecommunications band at 1550 nm, extending to 2260 nm. We discuss the motivation for the measurements and give theoretical context. We then describe the experimental setup, diagnostics, and procedure. The results show a breakdown threshold of 0.2J/cm{sup 2} at 1550 nm and 1.06 ps FWHM pulse duration, and a weak dependence on wavelength.

  7. The noncommutative QED threshold energy versus the optimum collision energy

    E-Print Network [OSTI]

    Zheng-Mao Sheng; Yongming Fu; Haibo Yu

    2004-02-10T23:59:59.000Z

    Moller Scattering and Bhabha Scattering on noncommutative space-time is restudied. It is shown that the noncommutative correction of scattering cross sections is not monotonous enhancement with the total energy of colliding electrons, there is an optimum collision energy to get the greatest noncommutative correction. Most surprisingly, there is a linear relation between the noncommutative QED threshold energy and the optimum collision energy.

  8. Threshold error rates for the toric and surface codes

    E-Print Network [OSTI]

    D. S. Wang; A. G. Fowler; A. M. Stephens; L. C. L. Hollenberg

    2009-05-05T23:59:59.000Z

    The surface code scheme for quantum computation features a 2d array of nearest-neighbor coupled qubits yet claims a threshold error rate approaching 1% (NJoP 9:199, 2007). This result was obtained for the toric code, from which the surface code is derived, and surpasses all other known codes restricted to 2d nearest-neighbor architectures by several orders of magnitude. We describe in detail an error correction procedure for the toric and surface codes, which is based on polynomial-time graph matching techniques and is efficiently implementable as the classical feed-forward processing step in a real quantum computer. By direct simulation of this error correction scheme, we determine the threshold error rates for the two codes (differing only in their boundary conditions) for both ideal and non-ideal syndrome extraction scenarios. We verify that the toric code has an asymptotic threshold of p = 15.5% under ideal syndrome extraction, and p = 7.8 10^-3 for the non-ideal case, in agreement with prior work. Simulations of the surface code indicate that the threshold is close to that of the toric code.

  9. Topology Control Problems Under Symmetric and Asymmetric Power Thresholds

    E-Print Network [OSTI]

    Krumke, Sven O.

    Topology Control Problems Under Symmetric and Asymmetric Power Thresholds Sven O. Krumke1 , Rui Liu performance guarantees. Previous work on topology control has assumed the symmetric power thresh- old model, NY 12222. Email: rav i@cs . a l bany . edu. Abstract. We consider topology control problems where

  10. An in situ calibration for hearing thresholds Robert H. Withnella

    E-Print Network [OSTI]

    Allen, Jont

    for the accuracy of hearing tests e.g., Voss et al., 2000 . In situ measurement of acoustic signals in the earAn in situ calibration for hearing thresholds Robert H. Withnella Department of Speech and Hearing has historically relied on acoustic calibration in physical assemblies with an input impedance

  11. Novel failure prognostics approach with dynamic thresholds for machine degradation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Novel failure prognostics approach with dynamic thresholds for machine degradation Kamran Javed-processing and prognostics modeling. To estimate RUL of a degrading machinery, prognostics modeling phase requires precise knowledge about failure thresh- old (FT) (or failure definition). Practically, degrading machinery can have

  12. Threshold-Controlled Global Cascading in Wireless Sensor Networks

    E-Print Network [OSTI]

    Varela, Carlos

    Threshold-Controlled Global Cascading in Wireless Sensor Networks Qiming Lu and G. Korniss is a challenging task. Wireless Sensor Networks (WSNs) provide an example where understanding dynamical processes and other wireless ad- hoc networks. First, sensor nodes are often densely deployed (typically 20 sensor per

  13. Effect of shrink fits on threshold speeds of rotordynamic instability 

    E-Print Network [OSTI]

    Al-Baz, Khalid A

    2001-01-01T23:59:59.000Z

    The purpose of this thesis is to study the effect of shrink fits on the threshold speeds of rotor instability. Shrink or press fit components in built-up rotors are known sources of internal friction damping. The internal friction damping increases...

  14. Polymer Collapse, Protein Folding, and the Percolation Threshold

    E-Print Network [OSTI]

    Meirovitch, Hagai

    Polymer Collapse, Protein Folding, and the Percolation Threshold HAGAI MEIROVITCH University (Macromolecules 1989, 22, 3986­3997) to study protein folding, where H and P are the hydrophobic and polar amino; computer simulation; collapse transition; protein folding Introduction The behavior of dilute polymer

  15. Weights of Exact Threshold Functions Laszlo Babai1

    E-Print Network [OSTI]

    Babai, László

    arnsfelt@cs.au.dk 3 Steklov Mathematical Institute podolskii@mi.ras.ru 4 ITCS, Tsinghua University inputs holds. The related class of (linear) threshold functions consist of those Boolean functions that decide whether a real valued linear inequality in their Boolean inputs holds. To be more precise

  16. “Pay What You Want” as Threshold Public Good Provision

    E-Print Network [OSTI]

    Mak, Vincent; Zwick, Rami; Rao, Akshay R.; Pattaratanakun, Jake A.

    2014-12-31T23:59:59.000Z

    ; feedback; market information “PAY WHAT YOU WANT” 2 “Pay What You Want” as Threshold Public Good Provision In a recent post on the Wikimedia Foundation website, Jimmy Wales, co-founder of Wikipedia, pleaded with users to donate to the website so...

  17. Apply early! Limited enrollment.

    E-Print Network [OSTI]

    volcano. Experience the culture and history of Hawaii, and the impact of human activitiesApply early! Limited enrollment. Environmental Science in the Hawaiian Islands Observe, research

  18. Optical Devices based on Limit Cycles and Amplification in Semiconductor Optical Cavities

    E-Print Network [OSTI]

    Hamerly, Ryan

    2015-01-01T23:59:59.000Z

    At strong pump powers, a semiconductor optical cavity passes through a Hopf bifurcation and undergoes self-oscillation. We simulate this device using semiclassical Langevin equations and assess the effect of quantum fluctuations on the dynamics. Below threshold, the cavity acts as a phase-insensitive linear amplifier, with noise $\\sim 5\\times$ larger than the Caves bound. Above threshold, the limit cycle acts as an analog memory, and the phase diffusion is $\\sim 10\\times$ larger than the bound set by the standard quantum limit. We also simulate entrainment of this oscillator and propose an optical Ising machine and classical CNOT gate based on the effect.

  19. Numerical investigation of the threshold for primordial black hole formation

    E-Print Network [OSTI]

    J. C. Niemeyer

    1998-06-02T23:59:59.000Z

    First results of a numerical investigation of primordial black hole formation in the radiation dominated phase of the Early Universe are presented. The simulations follow the gravitational collapse of three different families of high-amplitude density fluctuations imposed at the time of horizon crossing. The threshold for black hole formation, \\delta_{c} \\approx 0.7, is found to be nearly identical for all perturbation families if the control parameter, \\delta, is chosen as the total excess mass within the initial horizon volume. Furthermore, we demonstrate that the scaling of black hole mass with distance from the formation threshold, known to occur in near-critical gravitational collapse, applies to primordial black hole formation.

  20. Lowering the threshold in the DAMA dark matter detector

    SciTech Connect (OSTI)

    Kelso, Chris [Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112 (United States)

    2014-06-24T23:59:59.000Z

    We look at two improvements related to the DAMA/LIBRA dark matter detector. We show how using a more optimized binning scheme of the current data can lead to significantly tighter contraints on the compatible regions of the WIMP parameter space. In addition, the PMT’s of the detector were upgraded in 2010, allowing the low energy threshold to be lowered from 2 keVee to 1 keVee. We examine the implications for the dark matter interpretion of the DAMA modulation with data in this new energy region. Specifically, we focus on how well the degeneracy between the low mass and high mass regions can be removed by this new data. We find that the lower threshold data should rule out one of the two mass ranges in the spin-independent case at a minimum of the 2.6? level in the worst case scenario.

  1. LHC Beam Loss Measurements and Quench Level Abort Threshold Accuracy

    E-Print Network [OSTI]

    Dehning, B; Sapinski, M

    2010-01-01T23:59:59.000Z

    The LHC beam loss measurement system is designed to trigger the beam abort in case the magnet coil transition level from the superconducting to normal conducting sate is approached. The predicted heat deposition in the superconducting coils of the magnets has been determined by particle shower simulation codes, while for transient losses the enthalpy has been calculated. The results have been combined to determine the abort thresholds. Transient loss measurements of the energy depositions of lost protons with injected beams in the LHC are used to determine the accuracy of the beam abort threshold settings. The simulation predictions are reviewed and compared with the measurement results. The relative difference between measurements and simulation are between 30 to 50 %.

  2. On "Sub-Threshold" Reactions Involving Nuclear Fission

    E-Print Network [OSTI]

    M. Goldhaber; R. Shrock

    2000-11-29T23:59:59.000Z

    We analyze reactions of several types that are naively below threshold but can proceed because of the release of binding energy from nuclear fission and occasionally the formation of Coulombic bound states. These reactions include (i) photofission with pion production and (ii) charged current neutrino-nucleus reactions that lead to fission and/or formation of a Coulomb bound state of a $\\mu^-$ with the nucleus of a fission fragment. We comment on the possible experimental observation of these reactions.

  3. Performance Results of the AMS-01 Aerogel Threshold Cherenkov

    E-Print Network [OSTI]

    F. Mayet

    2000-02-16T23:59:59.000Z

    The Alpha Magnetic Spectrometer (AMS) was flown in june 1998 on board of the space shuttle Discovery (flight STS-91) at an altitude ranging between 320 and 390 km. This preliminary version of AMS included an Aerogel Threshold Cherenkov detector (ATC) to separate antiprotons from electron background, for momenta less than 3.5 GeV/c. In this paper, the design and physical principles of ATC will be discussed briefly, then the performance results of the ATC will be presented.

  4. Predicting threshold and location of laser damage on optical surfaces

    DOE Patents [OSTI]

    Siekhaus, Wigbert (Berkeley, CA)

    1987-01-01T23:59:59.000Z

    An apparatus useful in the prediction of the damage threshold of various optical devices, the location of weak spots on such devices and the location, identification, and elimination of optical surface impurities comprising, a focused and pulsed laser, an photo electric detector/imaging means, and a timer. The weak spots emit photoelectrons when subjected to laser intensities that are less than the intensity actually required to produce the damage. The weak spots may be eliminated by sustained exposure to the laser beam.

  5. Thresholded Lasso for high dimensional variable selection and statistical estimation

    E-Print Network [OSTI]

    Zhou, Shuheng

    2010-01-01T23:59:59.000Z

    Given $n$ noisy samples with $p$ dimensions, where $n \\ll p$, we show that the multi-step thresholding procedure based on the Lasso -- we call it the {\\it Thresholded Lasso}, can accurately estimate a sparse vector $\\beta \\in \\R^p$ in a linear model $Y = X \\beta + \\epsilon$, where $X$ is an $n \\times p$ design matrix, and $\\epsilon \\sim N(0, \\sigma^2 I_n)$. We show that under the restricted eigenvalue (RE) condition (Bickel-Ritov-Tsybakov 09), it is possible to achieve the $\\ell_2$ loss within a logarithmic factor of the ideal mean square error one would achieve with an {\\em oracle} while selecting a sufficiently sparse model -- hence achieving {\\it sparse oracle inequalities}; the oracle would supply perfect information about which coordinates are non-zero and which are above the noise level. In some sense, the Thresholded Lasso recovers the choices that would have been made by the $\\ell_0$ penalized least squares estimators, in that it selects a sufficiently sparse model without sacrificing the accuracy in ...

  6. Threshold Corrections to the Bottom Quark Mass Revisited

    E-Print Network [OSTI]

    Archana Anandakrishnan; B. Charles Bryant; Stuart Raby

    2015-01-29T23:59:59.000Z

    Threshold corrections to the bottom quark mass are often estimated under the approximation that tan$\\beta$ enhanced contributions are the most dominant. In this work we revisit this common approximation made to the estimation of the supersymmetric threshold corrections to the bottom quark mass. We calculate the full one-loop supersymmetric corrections to the bottom quark mass and survey a large part of the phenomenological MSSM parameter space to study the validity of considering only the tan$\\beta$ enhanced corrections. Our analysis demonstrates that this approximation underestimates the size of the threshold corrections by $\\sim$12.5% for most of the considered parameter space. We discuss the consequences for fitting the bottom quark mass and for the effective couplings to Higgses. We find that it is important to consider the additional contributions when fitting the bottom quark mass but the modifications to the effective Higgs couplings are typically $\\mathcal{O}$(few)% for the majority of the parameter space considered.

  7. Threshold model and the latest NA50 data on $J/?$ suppression in Pb+Pb collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2003-05-26T23:59:59.000Z

    Using the QGP motivated threshold model, where all the $J/\\psi$'s are suppressed above a threshold density, we have analyzed the latest version of the NA50 data on the centrality dependence of the $J/\\psi$ over Drell-Yan ratio. The data are not well explain in the model, unless the threshold density is largely smeared. Large smeared threshold density effectively excludes creation of any deconfined medium in the collision.

  8. Optical limiting materials

    DOE Patents [OSTI]

    McBranch, Duncan W. (Santa Fe, NM); Mattes, Benjamin R. (Santa Fe, NM); Koskelo, Aaron C. (Los Alamos, NM); Heeger, Alan J. (Santa Barbara, CA); Robinson, Jeanne M. (Los Alamos, NM); Smilowitz, Laura B. (Los Alamos, NM); Klimov, Victor I. (Los Alamos, NM); Cha, Myoungsik (Goleta, CA); Sariciftci, N. Serdar (Santa Barbara, CA); Hummelen, Jan C. (Groningen, NL)

    1998-01-01T23:59:59.000Z

    Optical limiting materials. Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO.sub.2) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400-1100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes.

  9. Estimating inventory thresholds for nuclear facilities using DOE STD-1027-92 Attachment 1 Table A.1 ``Thresholds for Radionuclides``

    SciTech Connect (OSTI)

    Price, D. [Onsite Engineering and Management, Inc. (United States); Hildum, J.S.; Williams, A.C. [Onsite Engineering and Management, Inc. (United States)

    1997-04-01T23:59:59.000Z

    It has recently been reports that Table A.1 of Attachment 1 of DOE STD-1027-92 is being improperly used to determine the Category 3 inventory threshold values for non-reactor nuclear facilities. The concern of this paper is that Safety Analysts and Facility Managers at the Lawrence Livermore National Laboratory (LLNL), as well as at other locations in the DOE Complex, are improperly using the entries in Table A.1. It is noted at this point that the common use of this table is to establish the lower thresholds for both Categories 2 and 3 non-reactor nuclear facilities by considering inventory quantities, as opposed to a postulated accident scenario. This paper will provide insight regarding this error and will show that the error is most likely non-conservative in nature.

  10. A Thesis for the Degree of Master of Science Provably Secure Threshold Blind

    E-Print Network [OSTI]

    Kim, Kwangjo

    A Thesis for the Degree of Master of Science Provably Secure Threshold Blind Signature Scheme Using Secure Threshold Blind Signature Scheme Using Pairings #12;Provably Secure Threshold Blind Signature and Communications University A thesis submitted to the faculty of Information and Commu- nications University

  11. Node-Replacement Policies to Maintain Threshold-Coverage in Wireless Sensor Networks

    E-Print Network [OSTI]

    Vokkarane, Vinod M.

    1 Node-Replacement Policies to Maintain Threshold-Coverage in Wireless Sensor Networks Sachin consider the problem of maintaining a minimum threshold-coverage in a wireless sensor network, while to maintain threshold-coverage in wireless sensor networks. These policies assess the candidature of each

  12. Fatigue threshold R-curves for predicting reliability of ceramics under cyclic loading

    E-Print Network [OSTI]

    Ritchie, Robert

    Fatigue threshold R-curves for predicting reliability of ceramics under cyclic loading J.J. Kruzic for the prediction of reliability in bridging ceramics under cyclic loading conditions based on a fatigue threshold R-curve threshold R-curve may express this crack-size dependence, analogous to the traditional fracture toughness R-curve

  13. A New (k, n)-Threshold Secret Sharing Scheme and Its Extension

    E-Print Network [OSTI]

    A New (k, n)-Threshold Secret Sharing Scheme and Its Extension Jun Kurihara, Shinsaku Kiyomoto)-threshold secret sharing scheme (threshold scheme), a heavy computational cost is required to make n shares and recover the secret. As a solution to this problem, several fast thresh- old schemes have been proposed

  14. Synchronization of Limit Sets

    E-Print Network [OSTI]

    Changpin Li; Weihua Deng

    2005-10-10T23:59:59.000Z

    In this Letter, we derive a sufficient condition of synchronizing limit sets (attractors and repellers) by using the linear feedback control technique proposed here. There examples are included. The numerical simulations and computer graphics show that our method work well.

  15. Quantum Limits of Thermometry

    E-Print Network [OSTI]

    Thomas M. Stace

    2010-06-08T23:59:59.000Z

    The precision of typical thermometers consisting of $N$ particles is shot noise limited, improving as $\\sim1/\\sqrt{N}$. For high precision thermometry and thermometric standards this presents an important theoretical noise floor. Here it is demonstrated that thermometry may be mapped onto the problem of phase estimation, and using techniques from optimal phase estimation, it follows that the scaling of the precision of a thermometer may in principle be improved to $\\sim1/N$, representing a Heisenberg limit to thermometry.

  16. Evaluation of exposures of hospital employees to anesthetic gases

    SciTech Connect (OSTI)

    Lambeth, J.D.

    1988-01-01T23:59:59.000Z

    Hospital employees who work in hospital operating and recovery rooms are often exposed to a number of anesthetic gases. There is evidence to support the belief that such exposures have led to higher rates of miscarriages and spontaneous abortions of pregnancies among women directly exposed to these gases than among women not exposed. Most of the studies assessing exposure levels were conducted prior to the widespread use of scavenging systems. Air sampling was conducted in hospital operatories and recovery rooms of three large hospitals to assess the current exposure levels in these areas and determine the effectiveness of these systems in reducing exposures to fluoride-containing anesthetic gases. It was determined that recovery-room personnel are exposed to levels of anesthesia gases that often approach and exceed the recommended Threshold Limit Value-Time Weighted Average (TLV-TWA) of 2.0 ppm. Recovery-room personnel do not have the protection from exposure provided by scavenging systems in operating rooms. Operating-room personnel were exposed to anesthesia gas levels above the TLV-TWA only when patients were masked, or connected and disconnected from the scavenging systems. Recovery-room personnel also need to be protected from exposure to anesthesia gases by a scavenging system.

  17. Threshold irradiation dose for amorphization of silicon carbide

    SciTech Connect (OSTI)

    Snead, L.L.; Zinkle, S.J.

    1997-03-01T23:59:59.000Z

    The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be {approximately}0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si{sup +} at 1 x 10{sup -3} dpa/s and with fission neutrons irradiated at 1 x 10{sup -6} dpa/s irradiated to 15 dpa in the temperature range of {approximately}340{+-}10K.

  18. Computing flux upper-limits for non-detections F. Masci, 10/25/2011

    E-Print Network [OSTI]

    Masci, Frank

    to "real" detections (e.g., in a spectrum), the quoted upper limits often lack probabilistic power. One in the first place, i.e., has flux measurement > some threshold set according to some maximum tolerable interval) that probably contains the true flux can then be assigned using the uncertainties. If a source

  19. Electron Rescattering in Above-Threshold Photodetachment of Negative Ions

    SciTech Connect (OSTI)

    Gazibegovic-Busuladzic, A. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegowina); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, D-12489 Berlin (Germany); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, D-12489 Berlin (Germany); Bergues, B.; Hultgren, H.; Kiyan, I. Yu. [Albert-Ludwigs-Universitaet, D-79104 Freiburg (Germany)

    2010-03-12T23:59:59.000Z

    We present experimental and theoretical results on photodetachment of Br{sup -} and F{sup -} in a strong infrared laser field. The observed photoelectron spectra of Br{sup -} exhibit a high-energy plateau along the laser polarization direction, which is identified as being due to the rescattering effect. The shape and the extension of the plateau is found to be influenced by the depletion of negative ions during the interaction with the laser pulse. Our findings represent the first observation of electron rescattering in above-threshold photodetachment of an atomic system with a short-range potential.

  20. Deuteron-deuteron scattering above four-nucleon breakup threshold

    E-Print Network [OSTI]

    Deltuva, A

    2015-01-01T23:59:59.000Z

    Deuteron-deuteron elastic scattering and transfer reactions in the energy regime above four-nucleon breakup threshold are described by solving exact four-particle equations for transition operators. Several realistic nuclear interaction models are used, including the one with effective many-nucleon forces generated by the explicit $\\Delta$-isobar excitation; the Coulomb force between protons is taken into account as well. Differential cross sections, deuteron analyzing powers, outgoing nucleon polarization, and deuteron-to-neutron polarization transfer coefficients are calculated at 10 MeV deuteron energy. Overall good agreement with the experimental data is found. The importance of breakup channels is demonstrated.

  1. Predicting threshold and location of laser damage on optical surfaces

    DOE Patents [OSTI]

    Siekhaus, W.

    1985-02-04T23:59:59.000Z

    Disclosed is an apparatus useful in the prediction of the damage threshold of various optical devices, the location of weak spots on such devices and the location, identification, and elimination of optical surface impurities. The apparatus comprises a focused and pulsed laser, a photo electric detector/imaging means, and a timer. The weak spots emit photoelectrons when subjected to laser intensities that are less than the intensity actually required to produce the damage. The weak spots may be eliminated by sustained exposure to the laser beam.

  2. Near-threshold production of the multi-strange $?^-$ hyperon

    E-Print Network [OSTI]

    P. Chung; N. N. Ajitanand; J. M. Alexander; M. Anderson; D. Best; F. P. Brady; T. Case; W. Caskey; D. Cebra; J. L. Chance; B. Cole; K. Crowe; A. C. Das; J. E. Draper; M. L. Gilkes; S. Gushue; M. Heffner; A. S. Hirsch; E. L. Hjort; W. Holzmann; L. Huo; M. Issah; M. Justice; M. Kaplan; D. Keane; J. C. Kintner; J. Klay; D. Krofcheck; R. A. Lacey; J. Lauret; M. A. Lisa; H. Liu; Y. M. Liu; J. Milan; R. McGrath; Z. Milosevich; G. Odyniec; D. L. Olson; S. Panitkin; N. T. Porile; G. Rai; H. G. Ritter; J. L. Romero; R. Scharenberg; B. Srivastava; N. T. B Stone; T. J. M. Symons; A. Taranenko; J. Whitfield; T. Wienold; R. Witt; L. Wood; W. N. Zhang; H. Oeschler

    2003-07-26T23:59:59.000Z

    The yield for the multi-strange $\\Xi^{-}$ hyperon has been measured in 6 AGeV Au+Au collisions via reconstruction of its decay products $\\pi^{-}$ and $\\Lambda$, the latter also being reconstructed from its daughter tracks of $\\pi^{-}$ and p. The measurement is rather close to the threshold for $\\Xi^{-}$ production and therefore provides an important test of model predictions. The measured yield for $\\Xi^{-}$ and $\\Lambda$ are compared for several centralities. In central collisions the $\\Xi^{-}$ yield is found to be in excellent agreement with statistical and transport model predictions, suggesting that multi-strange hadron production approaches chemical equilibrium in high baryon density nuclear matter.

  3. Optical limiting materials

    DOE Patents [OSTI]

    McBranch, D.W.; Mattes, B.R.; Koskelo, A.C.; Heeger, A.J.; Robinson, J.M.; Smilowitz, L.B.; Klimov, V.I.; Cha, M.; Sariciftci, N.S.; Hummelen, J.C.

    1998-04-21T23:59:59.000Z

    Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO{sub 2}) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400--1,100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes. 5 figs.

  4. Ionization Thresholds of Small Carbon Clusters: Tunable VUVExperiments and Theory

    SciTech Connect (OSTI)

    Belau, Leonid; Wheeler, Steven E.; Ticknor, Brian W.; Ahmed,Musahid; Leone, Stephen R.; Allen, Wesley D.; Schaefer III, Henry F.; Duncan, Michael A.

    2007-07-31T23:59:59.000Z

    Small carbon clusters (Cn, n = 2-15) are produced in amolecular beam by pulsed laser vaporization and studied with vacuumultraviolet (VUV) photoionization mass spectrometry. The required VUVradiation in the 8-12 eV range is provided by the Advanced Light Source(ALS) at the Lawrence Berkeley National Laboratory. Mass spectra atvarious ionization energies reveal the qualitative relative abundances ofthe neutral carbon clusters produced. By far the most abundant species isC3. Using the tunability of the ALS, ionization threshold spectra arerecorded for the clusters up to 15 atoms in size. The ionizationthresholds are compared to those measured previously with charge-transferbracketing methods. To interpret the ionization thresholds for differentcluster sizes, new ab initio calculations are carried out on the clustersfor n = 4-10. Geometric structures are optimized at the CCSD(T) levelwith cc-pVTZ (or cc-pVDZ) basis sets, and focal point extrapolations areapplied to both neutral and cation species to determine adiabatic andvertical ionization potentials. The comparison of computed and measuredionization potentials makes it possible to investigate the isomericstructures of the neutral clusters produced in this experiment. Themeasurements are inconclusive for the n = 4-6 species because ofunquenched excited electronic states. However, the data provide evidencefor the prominence of linear structures for the n = 7, 9, 11, 13 speciesand the presence of cyclic C10.

  5. New VLSI complexity results for threshold gate comparison

    SciTech Connect (OSTI)

    Beiu, V.

    1996-12-31T23:59:59.000Z

    The paper overviews recent developments concerning optimal (from the point of view of size and depth) implementations of COMPARISON using threshold gates. We detail a class of solutions which also covers another particular solution, and spans from constant to logarithmic depths. These circuit complexity results are supplemented by fresh VLSI complexity results having applications to hardware implementations of neural networks and to VLSI-friendly learning algorithms. In order to estimate the area (A) and the delay (T), as well as the classical AT{sup 2}, we shall use the following {open_quote}cost functions{close_quote}: (i) the connectivity (i.e., sum of fan-ins) and the number-of-bits for representing the weights and thresholds are used as closer approximations of the area; while (ii) the fan-ins and the length of the wires are used for closer estimates of the delay. Such approximations allow us to compare the different solutions-which present very interesting fan-in dependent depth-size and area-delay tradeoffs - with respect to AT{sup 2}.

  6. Damage thresholds of fluoride multilayers at 355 nm

    SciTech Connect (OSTI)

    Chow, R.; Kozlowski, M.R.; Loomis, G.E.; Rainer, F.

    1992-10-01T23:59:59.000Z

    Fluoride multilayer coatings were evaluated for use in 355 nm high reflector applications. The LaF[sub 3]/Na[sub 3]AlF[sub 6], NdF[sub 3]/Na[sub 3]AlF[sub 6] and GdF[sub 3]/Na[sub 3]AlF[sub 6] multilayers had laser damage thresholds of 20, 17.9 and 7.4 (measured at 10-ns pulsewidths), respectively. High tensile stresses in the coatings restricted this evaluation to only 5-layer-pair partial reflectors (49--52%).The LaF[sub 3]/Na[sub 3]AlF[sub 6], NdF[sub 3]/Na[sub 3]Al[sub 6] and GdF[sub 3]/Na[sub 3]AlF[sub 6] multilayers had tensile stresses of [approximately] 1.1 [times] 109, 1.3 [times] 109 and 9.3 [times] 10[sup 8] dynes/cm[sup 2], respectively. Substrate material and glow-discharge processing of the substrates were found to influence the density of stress-induced coating fractures and damage thresholds in some cases. If stress fracturing and scatter can be controlled, these fluoride material combinations are suited for 3[omega] applications.

  7. $J/?$ suppression in the threshold model and QGP formation time

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2007-09-03T23:59:59.000Z

    In the QGP motivated threshold model, in addition to the normal nuclear absorption, $J/\\psi$'s are subjected to an additional "anomalous" suppression. We have analysed the recently published PHENIX data on the participant number dependence of the nuclear modification factor for $J/\\psi$'s in Au+Au collisions and extracted the anomalous suppression required to explain the data. At mid rapidity $J/\\psi$'s are anomalously suppressed only above a threshold density $n_c$=3.73 fm$^{-2}$. The forward rapidity data on the otherhand require that $J/\\psi$'s are continuously "anomalously" suppressed. The analysis strongly indicate that in mid rapidity $J/\\psi$'s are suppressed in a deconfined medium. Using the PHENIX data on the participant number dependence of the Bjorken energy density, we have also estimated the QGP formation time. For critical temperature $T_c$=192 MeV, estimated QGP formation time ranges between 0.06-0.08 fm/c.

  8. Femtosecond pulse damage thresholds of dielectric coatings in vacuum

    SciTech Connect (OSTI)

    Michelle D. Shinn, Duy N. Nguyen, Luke A. Emmert ,Paul Schwoebel, Dinesh Patel, Carmen S. Menoni, Wolfgang Rudolph

    2011-03-01T23:59:59.000Z

    At 10-7 Torr, the multiple femtosecond pulse damage threshold, F(?), is about 10% of the single pulse damage fluence F(1) for hafnia and silica films compared to about 65% and 50%, respectively, at 630 Torr. In contrast, the single-pulse damage threshold is pressure independent. The decrease of F(?) with decreasing air pressure correlates with the water vapor and oxygen content of the ambient gas with the former having the greater effect. The decrease in F(?) is likely associated with an accumulation of defects derived from oxygen deficiency, for example vacancies. From atmospheric air pressure to pressures of {approx}3 x 10{sup -6} Torr, the damage 'crater' starts deterministically at the center of the beam and grows in diameter as the fluence increases. At pressure below 3x10-6 Torr, damage is initiated at random 'sites' within the exposed area in hafnia films, while the damage morphology remains deterministic in silica films. A possible explanation is that absorbing centers are created at predisposed sample sites in hafnia, for example at boundaries between crystallites, or crystalline and amorphous phases.

  9. More on the renormalization group limit cycle in QCD

    SciTech Connect (OSTI)

    Evgeny Epelbaum; Hans-Werner Hammer; Ulf-G. Meissner; Andreas Nogga

    2006-02-26T23:59:59.000Z

    We present a detailed study of the recently conjectured infrared renormalization group limit cycle in QCD using chiral effective field theory. We show that small increases in the up and down quark masses, corresponding to a pion mass around 200 MeV, can move QCD to the critical renormalization group trajectory for an infrared limit cycle in the three-nucleon system. At the critical values of the quark masses, the binding energies of the deuteron and its spin-singlet partner are tuned to zero and the triton has infinitely many excited states with an accumulation point at the three-nucleon threshold. At next-to-leading order in the chiral counting, we find three parameter sets where this effect occurs. For one of them, we study the structure of the three-nucleon system using both chiral and contact effective field theories in detail. Furthermore, we calculate the influence of the limit cycle on scattering observables.

  10. The pp->K+ n Sigma+ reaction near threshold

    E-Print Network [OSTI]

    Yu. Valdau; V. Koptev; S. Barsov; M. Büscher; S. Dymov; M. Hartmann; A. Kacharava; S. Merzliakov; S. Mikirtychyants; A. Mussgiller; M. Nekipelov; R. Schleichert; H. Ströher; C. Wilkin

    2007-03-27T23:59:59.000Z

    Inclusive K+ production in proton-proton collisions has been measured at a beam energy of 2.16 GeV using the COSY-ANKE magnetic spectrometer. The resulting spectrum, as well as those corresponding to K+ p and K+ pi+ correlated pairs, can all be well described using consistent values of the total cross sections for the pp->K+ p Lambda, pp->K+ p Sigma0, and pp->K+ n Sigma+ reactions. While the resulting values for Lambda and Sigma0 production are in good agreement with world data, our value for the total Sigma+ production cross section, sigma(pp->K+ n Sigma+) = 2.5+/-0.6(stat)+/-0.4(syst) mkb at an excess energy of epsilon=129 MeV, could only be reconciled with other recently published data if there were a highly unusual near--threshold behaviour.

  11. Threshold Verification Technique for Network Intrusion Detection System

    E-Print Network [OSTI]

    Faizal, M A; Shahrin, S; Robiah, Y; Rahayu, S Siti; Nazrulazhar, B

    2009-01-01T23:59:59.000Z

    Internet has played a vital role in this modern world, the possibilities and opportunities offered are limitless. Despite all the hype, Internet services are liable to intrusion attack that could tamper the confidentiality and integrity of important information. An attack started with gathering the information of the attack target, this gathering of information activity can be done as either fast or slow attack. The defensive measure network administrator can take to overcome this liability is by introducing Intrusion Detection Systems (IDSs) in their network. IDS have the capabilities to analyze the network traffic and recognize incoming and on-going intrusion. Unfortunately the combination of both modules in real time network traffic slowed down the detection process. In real time network, early detection of fast attack can prevent any further attack and reduce the unauthorized access on the targeted machine. The suitable set of feature selection and the correct threshold value, add an extra advantage for I...

  12. The Metastability Threshold for Modified Bootstrap Percolation in d Dimensions

    E-Print Network [OSTI]

    Alexander E. Holroyd

    2006-04-03T23:59:59.000Z

    In the modified bootstrap percolation model, sites in the cube {1,...,L}^d are initially declared active independently with probability p. At subsequent steps, an inactive site becomes active if it has at least one active nearest neighbour in each of the d dimensions, while an active site remains active forever. We study the probability that the entire cube is eventually active. For all d>=2 we prove that as L\\to\\infty and p\\to 0 simultaneously, this probability converges to 1 if L=exp^{d-1} (lambda+epsilon)/p, and converges to 0 if L=exp^{d-1} (lambda-epsilon)/p, for any epsilon>0. Here exp^n denotes the n-th iterate of the exponential function, and the threshold lambda equals pi^2/6 for all d.

  13. Nanowire-based ternary transistor by threshold-voltage manipulation

    SciTech Connect (OSTI)

    Han, Junebeom; Lim, Taekyung; Bong, Jihye; Seo, Keumyoung; Ju, Sanghyun, E-mail: shju@kgu.ac.kr [Department of Physics, Kyonggi University, Suwon, Gyeonggi-Do 443-760 (Korea, Republic of); Kim, Sunkook [Department of Electronics and Radio Engineering, Kyung Hee University, Yongin, Gyeonggi-Do 446-701 (Korea, Republic of)

    2014-04-07T23:59:59.000Z

    We report on a ternary device consisting of two nanowire channels that have different threshold voltage (V{sub th}) values and show that three current stages can be produced. A microscale laser-beam shot was utilized to selectively anneal the nanowire channel area to be processed, and the amount of V{sub th} shift could be controlled by adjusting the laser wavelength. Microscale laser annealing process could control V{sub th} of the individual nanowire transistors while maintaining the other parameters the constant, such as the subthreshold slope, on–off current ratio, and mobility. This result could provide a potential for highly integrated and high-speed ternary circuits.

  14. Triple photoionization of Ne and Ar near threshold

    SciTech Connect (OSTI)

    Bluett, J.B.; Wehlitz, R. [Synchrotron Radiation Center, UW-Madison, Stoughton, Wisconsin 53589 (United States); Lukic, D. [Institute of Physics, 11001 Belgrade (Serbia and Montenegro)

    2004-04-01T23:59:59.000Z

    The triple-photoionization cross section of neon and argon near threshold has been investigated by ion time-of-flight spectrometry. We applied the Wannier power law to our data and confirmed the theoretical Wannier exponent in the cases of Ne and Ar. Our data also agree with previous findings regarding the Wannier exponent and its range of validity for Ne. However, the Wannier power law exhibits a much smaller range of validity of 2 eV for Ar compared to 5 eV for Ne. Also, in contrast to a previous experiment, we do not find a 'second' power law but a gradual decrease of the exponent above the range of validity of the Wannier power law.

  15. Reexamination of an anomaly in near-threshold pair production

    SciTech Connect (OSTI)

    De Braeckeleer, L.; Adelberger, E.G.; Garcia, A. (Physics Department FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1992-11-01T23:59:59.000Z

    We investigated a reported anomaly in near-threshold pair production, using radioactive sources to measure the {gamma}+Ge{r arrow}{ital e}{sup +}+{ital e}{sup {minus}}+Ge cross-section at {ital E}{sub {gamma}}=1063, 1086, 1112, 1173, 1213, 1299, 1332, and 1408 keV. Although the data agree with the theory (numerical calculations based on an exact partial-wave formulation for a screened central potential) at the higher energies, the data lie above the theory at 1063, 1082, and 1112 keV. The discrepancy is reduced by including the final-state Coulomb interaction between the {ital e}{sup +} and {ital e}{sup {minus}}.

  16. The "Supercritical Pile" Model of GRB: Thresholds, Polarization, Time Lags

    E-Print Network [OSTI]

    Demosthenes Kazanas; Markos Georganopoulos; Apostolos Mastichiadis

    2003-11-21T23:59:59.000Z

    The essence of the ``Supercritical Pile'' model is a process for converting the energy stored in the relativistic protons of a Relativistic Blast Wave (RBW) of Lorentz factor $\\Gamma$ into electron -- positron pairs of similar Lorentz factor, while at the same time emitting most of the GRB luminosity at an energy $E_p \\simeq 1$ MeV. This is achieved by scattering the synchrotron radiation emitted by the RBW in an upstream located ``mirror'' and then re-intercepting it by the RBW. The repeated scatterings of radiation between the RBW and the ``mirror'', along with the threshold of the pair production reaction $p \\gamma \\to p e^-e^+$, lead to a maximum in the GRB luminosity at an energy $E_p \\simeq 1$ MeV, {\\sl independent of the value of $\\Gamma$}. Furthermore, the same threshold implies that the prompt $\\gamma-$ray emission is only possible for $\\Gamma$ larger than a minimum value, thereby providing a ``natural'' account for the termination of this stage of the GRB as the RBW slows down. Within this model the $\\gamma-$ray ($E \\sim 100$ keV -- 1 MeV) emission process is due to Inverse Compton scattering and it is thus expected to be highly polarized if viewed at angles $\\theta \\simeq 1/\\Gamma$ to the RBW's direction of motion. Finally, the model also predicts lags in the light curves of the lower energy photons with respect to those of higher energy; these are of purely kinematic origin and of magnitude $\\Delta t \\simeq 10^{-2}$ s, in agreement with observation.

  17. Bulk optical damage thresholds for doped and undoped, crystalline and ceramic yttrium aluminum garnet

    SciTech Connect (OSTI)

    Do, Binh T.; Smith, Arlee V.

    2009-06-20T23:59:59.000Z

    We measured the bulk optical damage thresholds of pure and Nd-doped ceramic yttrium aluminum garnet (YAG), and of pure, Nd-doped, Cr-doped, and Yb-doped crystalline YAG. We used 9.9 ns, 1064 nm, single-longitudinal mode, TEM00 pulses, to determine that the breakdown thresholds are deterministic, with multiple-pulse thresholds ranging from 1.1 to 2.2 kJ/cm{sup 2}.

  18. Fault current limiter

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2013-10-08T23:59:59.000Z

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  19. Laser-induced damage threshold of silicon in millisecond, nanosecond, and picosecond regimes

    SciTech Connect (OSTI)

    Wang, X.; Shen, Z. H.; Lu, J.; Ni, X. W. [School of Science, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2010-08-15T23:59:59.000Z

    Millisecond, nanosecond, and picosecond laser pulse induced damage thresholds on single-crystal are investigated in this study. The thresholds of laser-induced damage on silicon are calculated theoretically for three pulse widths based on the thermal damage model. An axisymmetric mathematical model is established for the transient temperature field of the silicon. Experiments are performed to test the damage thresholds of silicon at various pulse widths. The results indicate that the damage thresholds obviously increase with the increasing of laser pulse width. Additionally, the experimental results agree well with theoretical calculations and numerical simulation results.

  20. Error Channels and the Threshold for Fault-tolerant Quantum Computation

    E-Print Network [OSTI]

    Bryan Eastin

    2007-10-15T23:59:59.000Z

    This dissertation treats the topics of threshold calculation, ancilla construction, and non-standard error models. Chapter 2 introduces background material ranging from quantum mechanics to classical coding to thresholds for quantum computation. In Chapter 3 numerical and analytical means are used to generate estimates of and bounds on the threshold given an error model described by a restricted stochastic Pauli channel. Chapter 4 develops a simple, flexible means of estimating the threshold and applies it to some cases of interest. Finally, a novel method of ancilla construction is proposed in Chapter 5, and the difficulties associated with implementing it are discussed.

  1. (Limiting the greenhouse effect)

    SciTech Connect (OSTI)

    Rayner, S.

    1991-01-07T23:59:59.000Z

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  2. Low threshold organic and quantum dot nanobeam lasers

    E-Print Network [OSTI]

    Mahony, Thomas Stephen

    2014-01-01T23:59:59.000Z

    Lasers in the visible spectrum have many applications including sensing, medical, and entertainment applications. Traditional semiconductors face challenges that limit their ability to create lasers for the visible spectrum. ...

  3. The Limits of Quintessence

    SciTech Connect (OSTI)

    Caldwell, R.R.; Linder, Eric V.

    2005-05-24T23:59:59.000Z

    We present evidence that the simplest particle-physics scalar-field models of dynamical dark energy can be separated into distinct behaviors based on the acceleration or deceleration of the field as it evolves down its potential towards a zero minimum. We show that these models occupy narrow regions in the phase-plane of w and w', the dark energy equation-of-state and its time-derivative in units of the Hubble time. Restricting an energy scale of the dark energy microphysics limits how closely a scalar field can resemble a cosmological constant. These results, indicating a desired measurement resolution of order \\sigma(w')\\approx (1+w), define firm targets for observational tests of the physics of dark energy.

  4. Hydrodynamic sweepout thresholds in BWR Mark III reactor cavity interactions

    SciTech Connect (OSTI)

    Spencer, B.W.; Baronowsky, S.P.; Kilsdonk, D.J.

    1984-04-01T23:59:59.000Z

    Simulant-material experiments and related analysis are described which investigated hydrodynamics aspects of ex-vessel interactions following postulated core meltdown with subsequent meltthrough of the vessel lower head and ejection of molten corium from the vessel into the containment region beneath the vessel. Objectives were to examine the possible sweepout of water and corium from the cavity by the steam/H/sub 2/ flow. The dispersal pathways in this containment design include a single manway and four CRD penetrations in the cylindrical pedestal wall connecting to the drywell with a combined cross-sectional area of approx. 10 m/sup 2/. These openings range from 3.4 to 6.3 m in elevation off the concrete floor of the cavity. The experiments were performed using a 1:34 scale mock-up of the RPV/pedestal region. The first tests were quasi-steady tests. Tests were also performed using molten Wood's metal (WM). Some tests were performed with water on the cavity floor, and one test was performed using steel shot. The test results indicated that threshold gas flowrates existed beyond which dispersal of water and/or corium from the cavity can be expected. The predominant dispersal flow regime observed in the experiments involved fluidization of the water or molten WM by the gas flowrate through the system and sweepout of the fluidized liquid droplets as the gas exited the cavity through the openings in the wall. The superficial gas velocity at the onset of water sweepout ranged from 0.87 to 1.04 m/s in the tests which agrees very closely to the calculated fluidization threshold of 0.96 m/s. Application of the fluidization model for prediction of sweepout for the full-size system suggests that sweepout of water and corium can occur if the breach size in the RPV lower head exceeds approx. 10 and 17 cm dia, respectively, for steam blowdown at a vessel initial pressure of 1000 psi.

  5. Anomalous reduction of the switching voltage of Bi-doped Ge{sub 0.5}Se{sub 0.5} ovonic threshold switching devices

    SciTech Connect (OSTI)

    Seo, Juhee [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Ahn, Hyung-Woo [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Material Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Shin, Sang-yeol [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Korea Aerospace University, Goyang 412-791 (Korea, Republic of); Cheong, Byung-ki; Lee, Suyoun, E-mail: slee-eels@kist.re.kr [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)

    2014-04-14T23:59:59.000Z

    Switching devices based on Ovonic Threshold Switching (OTS) have been considered as a solution to overcoming limitations of Si-based electronic devices, but the reduction of switching voltage is a major challenge. Here, we investigated the effect of Bi-doping in Ge{sub 0.5}Se{sub 0.5} thin films on their thermal, optical, electrical properties, as well as on the characteristics of OTS devices. As Bi increased, it was found that both of the optical energy gap (E{sub g}{sup opt}) and the depth of trap states decreased resulting in a drastic reduction of the threshold voltage (V{sub th}) by over 50%. In addition, E{sub g}{sup opt} was found to be about three times of the conduction activation energy for each composition. These results are explained in terms of the Mott delocalization effect by doping Bi.

  6. Tumor delineation using PET in head and neck cancers: Threshold contouring and lesion volumes

    E-Print Network [OSTI]

    Yetisgen-Yildiz, Meliha

    PET/CT patient images. The intensity value of the threshold contour level that returns 100Tumor delineation using PET in head and neck cancers: Threshold contouring and lesion volumes Eric as a function of the reconstruction method, smoothing, and lesion size in head and neck cancer patients using

  7. An extremely sharp phase transition threshold for the slow growing hierarchy

    E-Print Network [OSTI]

    Weiermann, Andreas

    threshold point'. An everyday life example of this is the change from one material state to a different oneAn extremely sharp phase transition threshold for the slow growing hierarchy Andreas Weiermann of. This article is part of our general research program on phase transitions in logic

  8. WAVELET-BASED DENOISING BY CUSTOMIZED THRESHOLDING Byung-Jun Yoon and P. P. Vaidyanathan

    E-Print Network [OSTI]

    Yoon, Byung-Jun

    WAVELET-BASED DENOISING BY CUSTOMIZED THRESHOLDING Byung-Jun Yoon and P. P. Vaidyanathan Dept, nonlinear methods, especially those based on wavelets have become increasingly popular, due to a number of ad- vantages over the linear methods. It has been shown that wavelet- thresholding has near

  9. Design and implementation of a sub-threshold wireless BFSK transmitter

    E-Print Network [OSTI]

    Paul, Suganth

    2009-05-15T23:59:59.000Z

    signal. We design and fabricate a sub-threshold wireless BFSK transmitter chip. The transmitter is specified to transmit baseband signals up to a data rate of 32kbps over a distance of 1000m. In addition to the sub-threshold implementation, we implement...

  10. Design and implementation of a sub-threshold wireless BFSK transmitter

    E-Print Network [OSTI]

    Paul, Suganth

    2008-10-10T23:59:59.000Z

    signal. We design and fabricate a sub-threshold wireless BFSK transmitter chip. The transmitter is specified to transmit baseband signals up to a data rate of 32kbps over a distance of 1000m. In addition to the sub-threshold implementation, we implement...

  11. Lake-level changes in central Patagonia (Argentina): crossing environmental thresholds

    E-Print Network [OSTI]

    Gilli, Adrian

    Lake-level changes in central Patagonia (Argentina): crossing environmental thresholds, Argentina 5 CONICET/Universidad Nacional de la Patagonia Austral, Ri´o Gallegos, Santa Cruz, Argentina-level changes in central Patagonia (Argentina): crossing environmental thresholds for Lateglacial and Holocene

  12. UNCORRECTEDPROOF 1 Fecundity determines the extinction threshold in a Canadian assemblage

    E-Print Network [OSTI]

    Holland, Jeffrey

    suggested to have negative effects on forest species. We determined 13 the extinction threshold for 12, species caught moving outside forest habitat had lower extinction thresholds than 19 species not caught habitat loss affects the 39extinction risk of different species is therefore an 40important part

  13. Transition state vibrational level thresholds for the dissociation of triplet ketene

    E-Print Network [OSTI]

    Kim, Sang Kyu

    Transition state vibrational level thresholds for the dissociation of triplet ketene Sang Kyu Kim of a unimolecular reaction is controlled by flux through quantized transition-state thresholds at each energy level­Ramsperger­Kassel­Marcus RRKM theory. The vibrational frequencies at the transition state obtained from the fits are compared

  14. Ultra Low Power 2-tier 3D Stacked Sub-threshold H.264 Intra Frame Encoder

    E-Print Network [OSTI]

    Lim, Sung Kyu

    longer battery life and do not demand a fast frequency of operation. Sub-threshold cir- cuits beneficial to such unattended sensor networks by extending their battery life. Sub- threshold design helps us in-house tools to handle TSVs and 3D stacking. The standard cells were sized with Cadence Virtuoso

  15. A New Technique To Determine The Upper Threshold for Finite Length Turbo Codes

    E-Print Network [OSTI]

    Chaturvedi, A K

    A New Technique To Determine The Upper Threshold for Finite Length Turbo Codes A.Rajeshand A in finite frame length turbo codes. These thresholds depend on the component encoder as well as the frame to indecisive and unequivocal fixed points respectively, for finiteframe length turbo codes. Concurrently, Gamal

  16. In vivo transcranial cavitation threshold detection during ultrasound-induced bloodbrain barrier opening in mice

    E-Print Network [OSTI]

    Konofagou, Elisa E.

    In vivo transcranial cavitation threshold detection during ultrasound-induced blood­brain barrier cavitation threshold detection during ultrasound-induced blood­brain barrier opening in mice Yao-Sheng Tung1 cavitation response associated with blood­brain barrier (BBB) opening as induced by transcranial focused

  17. IEEE TRANSACTIONS ON DEPENDABLE AND SECURE COMPUTING 1 Epidemic Thresholds in Real Networks

    E-Print Network [OSTI]

    with viral spread exacerbates the problem [23]. The magnitude of viral propagation means that DDoS attacks at an exponential rate. Our epidemic threshold model subsumes many known thresholds for special-case graphs (e detrimental. With the exception of a few specialized modeling studies [18], [19], [28], [31], [34], much still

  18. Universality and scaling limit of weakly-bound tetramers

    E-Print Network [OSTI]

    M. R. Hadizadeh; M. T. Yamashita; Lauro Tomio; A. Delfino; T. Frederico

    2011-01-02T23:59:59.000Z

    The occurrence of a new limit cycle in few-body physics, expressing a universal scaling function relating the binding energies of two consecutive tetramer states, is revealed, considering a renormalized zero-range two-body interaction applied to four identical bosons. The tetramer energy spectrum is obtained when adding a boson to an Efimov bound state with energy $B_3$ in the unitary limit (for zero two-body binding, or infinite two-body scattering length). Each excited $N-$th tetramer energy $B_4^{(N)}$ is shown to slide along a scaling function as a short-range four-body scale is changed, emerging from the 3+1 threshold for a universal ratio $B_4^ {(N)}/B_3 \\simeq 4.6$, which does not depend on $N$. The new scale can also be revealed by a resonance in the atom-trimer recombination process.

  19. Universality and scaling limit of weakly-bound tetramers

    E-Print Network [OSTI]

    Hadizadeh, M R; Tomio, Lauro; Delfino, A; Frederico, T

    2011-01-01T23:59:59.000Z

    The occurrence of a new limit cycle in few-body physics, expressing a universal scaling function relating the binding energies of two consecutive tetramer states, is revealed, considering a renormalized zero-range two-body interaction applied to four identical bosons. The tetramer energy spectrum is obtained when adding a boson to an Efimov bound state with energy $B_3$ in the unitary limit (for zero two-body binding, or infinite two-body scattering length). Each excited $N-$th tetramer energy $B_4^{(N)}$ is shown to slide along a scaling function as a short-range four-body scale is changed, emerging from the 3+1 threshold for a universal ratio $B_4^ {(N)}/B_3 \\simeq 4.6$, which does not depend on $N$. The new scale can also be revealed by a resonance in the atom-trimer recombination process.

  20. High-energy above-threshold detachment from negative ions

    SciTech Connect (OSTI)

    Gazibegovic-Busuladzic, A.; Milosevic, D.B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2004-11-01T23:59:59.000Z

    Above-threshold detachment of electrons from negative ions by an elliptically polarized laser field is analyzed within the strong-field approximation. The low-energy part of the spectrum, that is, its structure and its apparent cutoff, strongly depends on the orbital quantum number l of the initial ground state. The high-energy part is characterized by the usual extended plateau caused by rescattering, which is essentially independent of the ground state. The potential that the returning electron experiences during rescattering is modeled by the sum of a polarization potential and a static potential. This rescattering potential does not have much effect on the shape of the plateau, but it does on its height. For H{sup -} (l=0), the yield of rescattered electrons is five orders of magnitude below the direct electrons, while for I{sup -} (l=1) the yields only differ by a factor of 40. We also analyze the dependence of the angle-resolved energy spectrum on the ellipticity of the laser field and confirm general symmetry properties. An angle-integrated elliptic dichroism parameter is introduced and analyzed.

  1. Near-threshold photodetachment of heavy alkali-metal anions

    SciTech Connect (OSTI)

    Bahrim, C.; Thumm, U.; Khuskivadze, A.A.; Fabrikant, I.I. [Department of Physics, Kansas State University, Manhattan, Kansas 66506-2604 (United States); Department of Chemistry and Physics, Lamar University, Beaumont, Texas 77710-10046 (United States); Department of Physics, Kansas State University, Manhattan, Kansas 66506-2604 (United States); Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States)

    2002-11-01T23:59:59.000Z

    We calculate near-threshold photodetachment cross sections for Rb{sup -}, Cs{sup -}, and Fr{sup -} using the Pauli equation method with a model potential describing the effective electron-atom interaction. Parameters of the model potential are fitted to reproduce ab initio scattering phase shifts obtained from Dirac R-matrix calculations. Special care is taken to formulate the boundary conditions near the atomic nucleus for solving the Pauli equation, based on the analytic solution of the Dirac equation for a Coulomb potential. We find a {sup 3}P{sub 1}{sup o} resonance contribution to the photodetachment cross section of Rb{sup -}, Cs{sup -}, and Fr{sup -} ions. Our calculated total photodetachment cross sections for Cs agree with experiments after tuning the resonance position by 2.4 meV. For Rb{sup -} and Fr{sup -} the resonance contribution is much smaller than for Cs. We therefore also provide angle-differential cross sections and asymmetry parameters which are much more sensitive to the resonant contribution than total cross sections.

  2. Photoproduction of $?(1520)$ hyperons from nuclei near the threshold

    E-Print Network [OSTI]

    E. Ya. Paryev

    2011-12-01T23:59:59.000Z

    We present a theoretical investigation of $\\Lambda(1520)$ attenuation in ${\\gamma}A$ reactions near the threshold. It is performed in the framework of a collision model based on the nuclear spectral function. The model accounts for both primary photon-nucleon ${\\gamma}N \\to K\\Lambda(1520)$ and secondary pion-nucleon ${\\pi}N \\to K\\Lambda(1520)$ production processes. We calculate the target mass and momentum dependences of the forward $\\Lambda(1520)$ hyperon production from nuclei at photon energy of 2 GeV as well as for two options for its in-medium width. We find that the considered dependences are markedly sensitive to this width. Our studies also demonstrate that the secondary channel ${\\pi}N \\to K\\Lambda(1520)$ plays a substantial role in the intermediate momentum $\\Lambda(1520)$ photoproduction on nuclei in the chosen kinematics and, hence, is to be taken into account in the analysis of $\\Lambda(1520)$ hyperon photoproduction from nuclei with the aim to get information on its width in the matter.

  3. Laser thermoelastic generation in metals above the melt threshold

    SciTech Connect (OSTI)

    Every, A. G. [School of Physics, University of the Witwatersrand, PO Wits 2050 (South Africa)] [School of Physics, University of the Witwatersrand, PO Wits 2050 (South Africa); Utegulov, Z. N. [Department of Physics, School of Science and Technology, Nazarbayev University, Astana 010000 (Kazakhstan)] [Department of Physics, School of Science and Technology, Nazarbayev University, Astana 010000 (Kazakhstan); Veres, I. A. [RECENDT Research Center for Non-Destructive Testing GmbH, A-4040 Linz (Austria)] [RECENDT Research Center for Non-Destructive Testing GmbH, A-4040 Linz (Austria)

    2013-11-28T23:59:59.000Z

    An approach is presented for calculating thermoelastic generation of ultrasound in a metal plate exposed to nanosecond pulsed laser heating, sufficient to cause melting but not ablation. Detailed consideration is given to the spatial and temporal profiles of the laser pulse, penetration of the laser beam into the sample, the appearance and subsequent growth and then contraction of the melt pool, and the time dependent thermal conduction in the melt and surrounding solid throughout. The excitation of the ultrasound takes place during and shortly after the laser pulse and occurs predominantly within the thermal diffusion length of a micron or so beneath the surface. It is shown how, because of this, the output of the thermal simulations can be expressed as axially symmetric transient radial and normal surface force distributions. The epicentral displacement response to these force distributions is obtained by two methods, the one based on the elastodynamic Green's functions for plate geometry determined by the Cagniard generalized ray method and the other using a finite element numerical method. The two approaches are in very close agreement. Numerical simulations are reported on the epicentral displacement response of a 3.12 mm thick tungsten plate irradiated with a 4 ns pulsed laser beam with Gaussian spatial profile, at intensities below and above the melt threshold.

  4. The sharp threshold for bootstrap percolation in all dimensions

    E-Print Network [OSTI]

    József Balogh; Béla Bollobás; Hugo Duminil-Copin; Robert Morris

    2011-02-24T23:59:59.000Z

    In r-neighbour bootstrap percolation on a graph G, a (typically random) set A of initially 'infected' vertices spreads by infecting (at each time step) vertices with at least r already-infected neighbours. This process may be viewed as a monotone version of the Glauber dynamics of the Ising model, and has been extensively studied on the d-dimensional grid $[n]^d$. The elements of the set A are usually chosen independently, with some density p, and the main question is to determine $p_c([n]^d,r)$, the density at which percolation (infection of the entire vertex set) becomes likely. In this paper we prove, for every pair $d \\ge r \\ge 2$, that there is a constant L(d,r) such that $p_c([n]^d,r) = [(L(d,r) + o(1)) / log_(r-1) (n)]^{d-r+1}$ as $n \\to \\infty$, where $log_r$ denotes an r-times iterated logarithm. We thus prove the existence of a sharp threshold for percolation in any (fixed) number of dimensions. Moreover, we determine L(d,r) for every pair (d,r).

  5. Review of exposure limits and experimental data for corneal and lenticular damage from short pulsed UV and IR laser radiation

    E-Print Network [OSTI]

    duration. The thermal UV damage data are compared with levels inferred from CO2 radiation thresholds exposure limits appear to be unnecessarily high. The lack of data for nanosecond exposures for wavelengths. The wavelength dependence of photochemical interac- tions and of the optical absorption properties

  6. COMMENTARY:Limits to adaptation

    SciTech Connect (OSTI)

    Preston, Benjamin L [ORNL

    2013-01-01T23:59:59.000Z

    An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.

  7. DESIGN CONSIDERATIONS ON PEAK POWER CLIPPING THRESHOLDS IN MICROGRIDS

    E-Print Network [OSTI]

    Paderborn, Universität

    the utility grid. This kind of operating strategy is called e.g. "peak load shaving", "peak power reduction. This method is broadly applicable to similar applications, e.g. for peak-shaving of PV power to limit" or just "peak shaving" and is applied to diverse applications and systems. This paper presents a method

  8. A factorization approach to next-to-leading-power threshold logarithms

    E-Print Network [OSTI]

    D. Bonocore; E. Laenen; L. Magnea; S. Melville; L. Vernazza; C. D. White

    2015-05-29T23:59:59.000Z

    Threshold logarithms become dominant in partonic cross sections when the selected final state forces gluon radiation to be soft or collinear. Such radiation factorizes at the level of scattering amplitudes, and this leads to the resummation of threshold logarithms which appear at leading power in the threshold variable. In this paper, we consider the extension of this factorization to include effects suppressed by a single power of the threshold variable. Building upon the Low-Burnett-Kroll-Del Duca (LBKD) theorem, we propose a decomposition of radiative amplitudes into universal building blocks, which contain all effects ultimately responsible for next-to-leading power (NLP) threshold logarithms in hadronic cross sections for electroweak annihilation processes. In particular, we provide a NLO evaluation of the "radiative jet function", responsible for the interference of next-to-soft and collinear effects in these cross sections. As a test, using our expression for the amplitude, we reproduce all abelian-like NLP threshold logarithms in the NNLO Drell-Yan cross section, including the interplay of real and virtual emissions. Our results are a significant step towards developing a generally applicable resummation formalism for NLP threshold effects, and illustrate the breakdown of next-to-soft theorems for gauge theory amplitudes at loop level.

  9. Low-energy-threshold analysis of the Phase I and Phase II data sets of the Sudbury Neutrino Observatory

    E-Print Network [OSTI]

    Monroe, Jocelyn

    Results are reported from a joint analysis of Phase I and Phase II data from the Sudbury Neutrino Observatory. The effective electron kinetic energy threshold used is Teff=3.5 MeV, the lowest analysis threshold yet achieved ...

  10. HOSPITAL VENTILATION STANDARDS AND ENERGY CONSERVATION: A SUMMARY OF THE LITERATURE WITH CONCLUSIONS AND RECOMMENDATIONS, FY 78 FINAL REPORT

    E-Print Network [OSTI]

    DeRoos, R.L.

    2011-01-01T23:59:59.000Z

    ESTIMATED LITERS/NONTH TLV (EEm) NIOSH ACGIH ACGIH ACGIHPainters - Solvent TLV (EEm) ACGIH Vinyl Chloride (Monomer)

  11. Comparison of the "method of limits" and "alternate choice" methods in vibrometry testing

    E-Print Network [OSTI]

    Hayes, Eloise Carlton

    1992-01-01T23:59:59.000Z

    are the "method of limits" and "alternate choice" techniques. This investigation evaluated and compared these two techniques. The primary purpose of this investigation was to determine if these testing methods obtain the same vibration threshold... and to invesugate the relationship between the methods. The methods were used to test male and female populations for their vibration sensitivity in the median nerve (index finger) and the ulnar nerve (little finger) of both hands. This study utilized...

  12. Measurement Of Transverse Instability Thresholds In Low And high Emittance optics At The Photon Factory Storage Ring

    E-Print Network [OSTI]

    Sakanaka, S; Kamiya, Yu; Katoh, M; Kobayakawa, H

    1990-01-01T23:59:59.000Z

    Measurement Of Transverse Instability Thresholds In Low And high Emittance optics At The Photon Factory Storage Ring

  13. e08-008: Exclusive study of deuteron electrodisintegration near threshold

    SciTech Connect (OSTI)

    Hanretty, Charles [JLAB, Newport News, VA (United States)

    2014-01-01T23:59:59.000Z

    The study of threshold electrodisintegration of and elastic scattering on the only stable two nucleon system, the deuteron, can reveal specific aspects of the N-N interaction. The simplicity of electrodisintegration along with the simplicity of the deuteron makes this study most appropriate for revealing these interactions. By using an incident beam of polarized electrons and by measuring the polarization of the recoiling proton, the ratio of the electric (G{sub E} ) and magnetic (G{sub M} ) form factors for d((vector e),e?(vector p)) (and p((vector e) ,e?(vector p))) reactions may be extracted. This experiment was conducted in Hall A at Jefferson Lab in Newport News, Virginia using a beam of polarized electrons provided by the CEBAF Accelerator incident on a liquid deuterium (and hydrogen) target. The scattered electron and the recoiling (polarized) proton were detected using the High Resolution Spectrometers of Hall A. To determine the polarization of the recoil proton, an analyzing material was placed perpendicular to the protons trajectory through the spectrometer, in front of a set of straw chambers. Due to the spin-orbit interactions involved in the scattering of the proton from the analyzer material, asymmetries seen in the distribution of events detected by these straw chambers reveal the polarization of the recoil proton. By tracking the spin procession of the polarized protons from the straw chambers back to the target, the transferred and induced polarization of the proton may be determined. The (double-spin) asymmetries observed in the straw chambers will first be studied for the well-known elastic p((vector e), e?(vector p)) process and compared to the asymmetries for d((vector e),e?(vector p))n(x{sub B}=1) . The analysis will then be repeated to determine how these asymmetries change with increasing x{sub B} (to the kinematic limit for deuteron electrodisintegration).

  14. A Comparison of "Total Dust" and Inhalable Personal Sampling for Beryllium Exposure.

    SciTech Connect (OSTI)

    Carter, C M

    2012-04-25T23:59:59.000Z

    In 2009, the American Conference of Governmental Industrial Hygienists (ACGIH) reduced the Beryllium (Be) 8-hr Time Weighted Average Threshold Limit Value (TLV-TWA) from 2.0 {micro}g/m{sup 3} to 0.05 {micro}g/m{sup 3} with an inhalable 'I' designation in accordance with ACGIH's particle size-selective criterion for inhalable mass. Currently, per the Department of Energy (DOE) requirements, the Lawrence Livermore National Laboratory (LLNL) is following the Occupational Health and Safety Administration (OSHA) Permissible Exposure Limit (PEL) of 2.0 {micro}g/m{sup 3} as an 8-hr TWA, which is also the 2005 ACGIH TLV-TWA, and an Action Level (AL) of 0.2 {micro}g/m{sup 3} and sampling is performed using the 37mm (total dust) sampling method. Since DOE is considering adopting the newer 2009 TLV guidelines, the goal of this study was to determine if the current method of sampling using the 37mm (total dust) sampler would produce results that are comparable to what would be measured using the IOM (inhalable) sampler specific to the application of high energy explosive work at LLNL's remote experimental test facility at Site 300. Side-by-side personal sampling using the two samplers was performed over an approximately two-week period during chamber re-entry and cleanup procedures following detonation of an explosive assembly containing Beryllium (Be). The average ratio of personal sampling results for the IOM (inhalable) vs. 37-mm (total dust) sampler was 1.1:1 with a P-value of 0.62, indicating that there was no statistically significant difference in the performance of the two samplers. Therefore, for the type of activity monitored during this study, the 37-mm sampling cassette would be considered a suitable alternative to the IOM sampler for collecting inhalable particulate matter, which is important given the many practical and economic advantages that it presents. However, similar comparison studies would be necessary for this conclusion to be applied to other types of activities, where earlier studies have shown that the IOM sampler tends to collect higher concentrations of Be compared to the 37-mm cassette, which could complicate compliance with what is already an extremely low exposure limit.

  15. An Excitatory Loop with Astrocytes Contributes to Drive Neurons to Seizure Threshold

    E-Print Network [OSTI]

    Newman, Eric A.

    An Excitatory Loop with Astrocytes Contributes to Drive Neurons to Seizure Threshold Marta Go´ mez to control seizures. Citation: Go´mez-Gonzalo M, Losi G, Chiavegato A, Zonta M, Cammarota M, et al. (2010

  16. Long-Range Validity of Threshold Laws in Inner-Shell Photodetachment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the ALS, and Denison University has now shown that the threshold laws for inner-shell photodetachment of negative ions are not only obeyed but can extend over a much...

  17. $pp\\to pp?^0$ near threshold in pionless effective field theory

    E-Print Network [OSTI]

    Shung-ichi Ando

    2007-08-30T23:59:59.000Z

    In this talk, we review our recent calculation for the $pp\\to pp\\pi^0$ reaction near threshold in pionless effective field theory with a di-baryon and external pions.

  18. Increased Resilience in Threshold Cryptography Sharing a Secret with Devices That Cannot Store Shares

    E-Print Network [OSTI]

    -mail, authorise bank transactions or access social network sites. As a consequence, personal devices are used more of battery power. These weaknesses can be mitigated by introducing threshold cryptography. The aim

  19. Intensity-resolved Above Threshold Ionization Yields of Atoms with Ultrashort Laser Pulses

    E-Print Network [OSTI]

    Hart, Nathan Andrew

    2012-10-19T23:59:59.000Z

    The above threshold ionization (ATI) spectra provide a diversity of information about a laser-atom ionization process such as laser intensity, pulse duration, carrier envelope phase, and atomic energy level spacing. However, the spatial distribution...

  20. Soft pneumatic artificial muscles with low threshold pressures for a cardiac compression device

    E-Print Network [OSTI]

    Obiajulu, Steven (Steven C.)

    2013-01-01T23:59:59.000Z

    In this paper, I present the design, fabrication and characterization of fully soft pneumatic artificial muscles (PAMs) with low threshold pressures that are intended for direct cardiac compression (DCC). McKibben type ...

  1. Hair cell regeneration and recovery of auditory thresholds following aminoglycoside ototoxicity in Bengalese nches

    E-Print Network [OSTI]

    Rubel, Edwin

    Hair cell regeneration and recovery of auditory thresholds following aminoglycoside ototoxicity Birds regenerate auditory hair cells when original hair cells are lost. Regenerated hair cells become innervated and restore hearing function. Functional recovery during hair cell regeneration is particularly

  2. The Transition to Experiencing: I. Limited Learning and Limited Experiencing

    E-Print Network [OSTI]

    Indiana University

    The Transition to Experiencing: I. Limited Learning and Limited Experiencing Simona Ginsburg route for the transition from sensory processing to unlimited experiencing, or basic consciousness. We the transition. We believe that the raw mate- rial from which feelings were molded by natural selection

  3. Influence of the backward propagating waves on the threshold in planar nematic liquid crystal films

    E-Print Network [OSTI]

    Dmitry O. Krimer; Andrey E. Miroshnichenko; Etienne Brasselet

    2010-10-19T23:59:59.000Z

    We analyze theoretically the influence of backward propagating waves on the primary threshold when a linearly polarized light impinges at normal incidence on a planarly aligned nematic liquid crystal films. We show, that the primary threshold, as a function of the phase delay induced by the nematic layer, exhibits oscillations. The amplitude of oscillations depends strongly on the drop of the refractivity indices of the nematic and outer media at the boundaries.

  4. An analysis of the threshold necessary to sustain rural Texas retail outlets

    E-Print Network [OSTI]

    Adcock, Donna P

    1992-01-01T23:59:59.000Z

    AN ANALYSIS OF THE THRESHOLD NECESSARY TO SUSTAIN RURAL TEXAS RETAIL OUTLETS A Thesis by DONNA PFLUGER ADCOCK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1992 Major Subject: Agricultural Economics AN ANALYSIS OF THE THRESHOLD NECESSARY TO SUSTAIN RURAL TEXAS RETAIL OUTLETS A Thesis by DONNA PFLUGER ADCOCK Approved as to style and content by: Dennis U. Fisher (Chair...

  5. Limit theory for overfit models

    E-Print Network [OSTI]

    Calhoun, Grayson Ford

    2009-01-01T23:59:59.000Z

    theory. . . . . . . . . . . . . . . . . . . . . . . . .1.2 Asymptotic Theory and Main Results . . . . . . . . .Chapter 2 Limit theory for comparing over?t models out-of-

  6. How to identify the structure of near-threshold states from the line shape

    E-Print Network [OSTI]

    Guo-Ying Chen; Wen-Sheng Huo; Qiang Zhao

    2014-10-29T23:59:59.000Z

    We revisit the compositeness theorem proposed by Weinberg in an effective field theory (EFT) and explore criteria which are sensitive to the structure of $S$-wave threshold states. On a general basis, we show that the wave function renormalization constant $Z$, which is the probability of finding an elementary component in the wave function of a threshold state, can be explicitly introduced in the description of the threshold state. As an application of this EFT method, we describe the near-threshold line shape of the $D^{\\ast 0}\\bar D^0$ invariant mass spectrum in $B\\rightarrow D^{\\ast 0}\\bar D^0 K$ and determine a nonvanishing value of $Z$. It suggests that the $X(3872)$ as a candidate of the $D^{\\ast 0}\\bar D^0$ molecule may still contain a small $c\\bar{c}$ core. This elementary component, on the one hand, explains its production in the $B$ meson decay via a short-distance mechanism, and on the other hand, is correlated with the $D^{\\ast 0}\\bar D^0$ threshold enhancement observed in the $D^{\\ast 0}\\bar D^0$ invariant mass distributions. Meanwhile, we also show that if $Z$ is non-zero, the near-threshold enhancement of the $D^{\\ast 0}\\bar D^0$ mass spectrum in the $B$ decay will be driven by the short-distance production mechanism. This conclusion is still true even if the long-distance production is enhanced by some unexpected mechanism.

  7. Tumor delineation using PET in head and neck cancers: Threshold contouring and lesion volumes

    SciTech Connect (OSTI)

    Ford, Eric C.; Kinahan, Paul E.; Hanlon, Lorraine; Alessio, Adam; Rajendran, Joseph; Schwartz, David L.; Phillips, Mark [University of Washington, Department of Radiation Oncology, 1959 N. E. Pacific Street, Seattle, Washington 98195 (United States) and Puget Sound Veterans Administration, 18801 S. Columbian Way, Seattle, Washington 98195 (United States); University of Washington, Department of Radiology, 1959 N. E. Pacific Street, Seattle, Washington 98195 (United States); University of Washington, Department of Radiation Oncology, 1959 N. E. Pacific Street, Seattle, Washington 98195 and School of Physics, University College Dublin (Ireland); University of Washington, Department of Radiology, 1959 N. E. Pacific Street, Seattle, Washington 98195 (United States); University of Texas, M.D. Anderson Cancer Center, Department of Radiation Oncology, 1515 Holcombe Blvd., Houston, Texas 77030 and Puget Sound Veterans Administration, 1880 S. Columbian Way, Seattle, Washington 98195 (United States); University of Washington, Department of Radiation Oncology, 1959 N. E. Pacific Street, Seattle, Washington 98195 (United States)

    2006-11-15T23:59:59.000Z

    Tumor boundary delineation using positron emission tomography (PET) is a promising tool for radiation therapy applications. In this study we quantify the uncertainties in tumor boundary delineation as a function of the reconstruction method, smoothing, and lesion size in head and neck cancer patients using FDG-PET images and evaluate the dosimetric impact on radiotherapy plans. FDG-PET images were acquired for eight patients with a GE Advance PET scanner. In addition, a 20 cm diameter cylindrical phantom with six FDG-filled spheres with volumes of 1.2 to 26.5 cm{sup 3} was imaged. PET emission scans were reconstructed with the OSEM and FBP algorithms with different smoothing parameters. PET-based tumor regions were delineated using an automatic contouring function set at progressively higher threshold contour levels and the resulting volumes were calculated. CT-based tumor volumes were also contoured by a physician on coregistered PET/CT patient images. The intensity value of the threshold contour level that returns 100% of the actual volume, I{sub V100}, was measured. We generated intensity-modulated radiotherapy (IMRT) plans for an example head and neck patient, treating 66 Gy to CT-based gross disease and 54 Gy to nodal regions at risk, followed by a boost to the FDG-PET-based tumor. The volumes of PET-based tumors are a sensitive function of threshold contour level for all patients and phantom datasets. A 5% change in threshold contour level can translate into a 200% increase in volume. Phantom data indicate that I{sub V100} can be set as a fraction, f, of the maximum measured uptake. Fractional threshold values in the cylindrical water phantom range from 0.23 to 0.51. Both the fractional threshold and the threshold-volume curve are dependent on lesion size, with lesions smaller than approximately 5 cm{sup 3} displaying a more pronounced sensitivity and larger fractional threshold values. The threshold-volume curves and fractional threshold values also depend on the reconstruction algorithm and smoothing filter with more smoothing requiring a higher fractional threshold contour level. The threshold contour level affects the tumor size, and therefore the ultimate boost dose that is achievable with IMRT. In an example head and neck IMRT plan, the D95 of the planning target volume decreased from 7770 to 7230 cGy for 42% vs 55% contour threshold levels. PET-based tumor volumes are strongly affected by the choice of threshold level. This can have a significant dosimetric impact. The appropriate threshold level depends on lesion size and image reconstruction parameters. These effects should be carefully considered when using PET contour and/or volume information for radiotherapy applications.

  8. FUEL CASK IMPACT LIMITER VULNERABILITIES

    SciTech Connect (OSTI)

    Leduc, D; Jeffery England, J; Roy Rothermel, R

    2009-02-09T23:59:59.000Z

    Cylindrical fuel casks often have impact limiters surrounding just the ends of the cask shaft in a typical 'dumbbell' arrangement. The primary purpose of these impact limiters is to absorb energy to reduce loads on the cask structure during impacts associated with a severe accident. Impact limiters are also credited in many packages with protecting closure seals and maintaining lower peak temperatures during fire events. For this credit to be taken in safety analyses, the impact limiter attachment system must be shown to retain the impact limiter following Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC) impacts. Large casks are often certified by analysis only because of the costs associated with testing. Therefore, some cask impact limiter attachment systems have not been tested in real impacts. A recent structural analysis of the T-3 Spent Fuel Containment Cask found problems with the design of the impact limiter attachment system. Assumptions in the original Safety Analysis for Packaging (SARP) concerning the loading in the attachment bolts were found to be inaccurate in certain drop orientations. This paper documents the lessons learned and their applicability to impact limiter attachment system designs.

  9. Performance Limits for Cherenkov Instruments

    E-Print Network [OSTI]

    W. Hofmann

    2006-03-17T23:59:59.000Z

    The performance of Cherenkov instruments for the detection of very high energy gamma rays is ultimately limited by the fluctuations in the development of air showers. With particular emphasis on the angular resolution, the ultimate performance limits are investigated on the basis of simulations.

  10. Congressional Request Limiting the Magnitude

    E-Print Network [OSTI]

    as goals? Target: limit U.S. GHG emissions (e.g., national emission budget, or percent reduction) What is a reasonable share of U.S. emission reductions relative to the global targets? What is the implied emissions on atmospheric GHG concentrations? Target: limit atmospheric GHG concentrations (e.g., 450, 550 ppm CO2,eq) How

  11. High Energy Thresholds in SUSY GUTs - A refined analysis

    E-Print Network [OSTI]

    A. Katsikatsou

    2014-11-26T23:59:59.000Z

    In a previous paper we have developed a novel method in order to parametrize the effect of the large number of HETs into as fewer parameters as possible. Apart from its obvious advantages this parametrization serves as a vehicle for the examination of the validity of a minimal SO(10) model concerning a series of constraints. Among them is demand for unification of the gauge couplings, the experimental values of the strong coupling constant and lower experimental bound of the proton lifetime. All of these claims lead to preferred regions both in the soft the superheavy parameter space. In this paper we give the necessary updates of our results which stem mainly from the recent experimental measurements. We also include some additions in our analysis involving the universal trilinear coupling A_0 and the rate x, which is related to superheavy vevs. Finally we cross-check the preferred regions of the parameter space and narrow the even more by applying new constraints based on the results of the LHC experiment for the mass of the Higgs particle and the supersymmetry exclusion limits.

  12. Optical breakdown threshold investigation of 1064 nm laser induced air plasmas

    SciTech Connect (OSTI)

    Thiyagarajan, Magesh; Thompson, Shane [Plasma Engineering Research Lab (PERL), College of Science and Engineering, Texas A and M University-Corpus Christi, Texas 78412 (United States)

    2012-04-01T23:59:59.000Z

    We present the theoretical and experimental measurements and analysis of the optical breakdown threshold for dry air by 1064 nm infrared laser radiation and the significance of the multiphoton and collisional cascade ionization process on the breakdown threshold measurements over pressures range from 10 to 2000 Torr. Theoretical estimates of the breakdown threshold laser intensities and electric fields are obtained using two distinct theories namely multiphoton and collisional cascade ionization theories. The theoretical estimates are validated by experimental measurements and analysis of laser induced breakdown processes in dry air at a wavelength of 1064 nm by focusing 450 mJ max, 6 ns, 75 MW max high-power 1064 nm IR laser radiation onto a 20 {mu}m radius spot size that produces laser intensities up to 3 - 6 TW/cm{sup 2}, sufficient for air ionization over the pressures of interest ranging from 10 to 2000 Torr. Analysis of the measured breakdown threshold laser intensities and electric fields are carried out in relation with classical and quantum theoretical ionization processes, operating pressures. Comparative analysis of the laser air breakdown results at 1064 nm with corresponding results of a shorter laser wavelength (193 nm) [M. Thiyagarajan and J. E. Scharer, IEEE Trans. Plasma Sci. 36, 2512 (2008)] and a longer microwave wavelength (10{sup 8} nm) [A. D. MacDonald, Microwave Breakdown in Gases (Wiley, New York, 1966)]. A universal scaling analysis of the breakdown threshold measurements provided a direct comparison of breakdown threshold values over a wide range of frequencies ranging from microwave to ultraviolet frequencies. Comparison of 1064 nm laser induced effective field intensities for air breakdown measurements with data calculated based on the collisional cascade and multiphoton breakdown theories is used successfully to determine the scaled collisional microwave portion. The measured breakdown threshold of 1064 nm laser intensities are then scaled to classical microwave breakdown theory after correcting for the multiphoton ionization process for different pressures and good agreement, regarding both pressure dependence and breakdown threshold electric fields, is obtained. The effect of the presence of submicron particles on the 1064 nm breakdown threshold was also investigated. The measurements show that higher breakdown field is required, especially at lower pressures, and in close agreement with classical microwave breakdown theory and measurements in air.

  13. Threshold velocity for environmentally-assisted cracking in low alloy steels

    SciTech Connect (OSTI)

    Wire, G.L.; Kandra, J.T.

    1997-04-01T23:59:59.000Z

    Environmentally Assisted Cracking (EAC) in low alloy steels is generally believed to be activated by dissolution of MnS inclusions at the crack tip in high temperature LWR environments. EAC is the increase of fatigue crack growth rate of up to 40 to 100 times the rate in air that occurs in high temperature LWR environments. A steady state theory developed by Combrade, suggested that EAC will initiate only above a critical crack velocity and cease below this same velocity. A range of about twenty in critical crack tip velocities was invoked by Combrade, et al., to describe data available at that time. This range was attributed to exposure of additional sulfides above and below the crack plane. However, direct measurements of exposed sulfide densities on cracked specimens were performed herein and the results rule out significant additional sulfide exposure as a plausible explanation. Alternatively, it is proposed herein that localized EAC starting at large sulfide clusters reduces the calculated threshold velocity from the value predicted for a uniform distribution of sulfides. Calculations are compared with experimental results where the threshold velocity has been measured, and the predicted wide range of threshold values for steels of similar sulfur content but varying sulfide morphology is observed. The threshold velocity decreases with the increasing maximum sulfide particle size, qualitatively consistent with the theory. The calculation provides a basis for a conservative minimum velocity threshold tied directly to the steel sulfur level, in cases where no details of sulfide distribution are known.

  14. Estimating Alarm Thresholds for Process Monitoring Data under Different Assumptions about the Data Generating Mechanism

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Burr, Tom; Hamada, Michael S.; Howell, John; Skurikhin, Misha; Ticknor, Larry; Weaver, Brian

    2013-01-01T23:59:59.000Z

    Process monitoring (PM) for nuclear safeguards sometimes requires estimation of thresholds corresponding to small false alarm rates. Threshold estimation dates to the 1920s with the Shewhart control chart; however, because possible new roles for PM are being evaluated in nuclear safeguards, it is timely to consider modern model selection options in the context of threshold estimation. One of the possible new PM roles involves PM residuals, where a residual is defined as residual = data ? prediction. This paper reviews alarm threshold estimation, introduces model selection options, and considers a range of assumptions regarding the data-generating mechanism for PM residuals.more »Two PM examples from nuclear safeguards are included to motivate the need for alarm threshold estimation. The first example involves mixtures of probability distributions that arise in solution monitoring, which is a common type of PM. The second example involves periodic partial cleanout of in-process inventory, leading to challenging structure in the time series of PM residuals.« less

  15. Measurement and interpretation of threshold stress intensity factors for steels in high-pressure hydrogen gas.

    SciTech Connect (OSTI)

    Dadfarnia, Mohsen (University of Illinois at Urbana-Champaign, Urbana, IL); Nibur, Kevin A.; San Marchi, Christopher W.; Sofronis, Petros (University of Illinois at Urbana-Champaign, Urbana, IL); Somerday, Brian P.; Foulk, James W., III; Hayden, Gary A. (CP Industries, McKeesport, PA)

    2010-07-01T23:59:59.000Z

    Threshold stress intensity factors were measured in high-pressure hydrogen gas for a variety of low alloy ferritic steels using both constant crack opening displacement and rising crack opening displacement procedures. The sustained load cracking procedures are generally consistent with those in ASME Article KD-10 of Section VIII Division 3 of the Boiler and Pressure Vessel Code, which was recently published to guide design of high-pressure hydrogen vessels. Three definitions of threshold were established for the two test methods: K{sub THi}* is the maximum applied stress intensity factor for which no crack extension was observed under constant displacement; K{sub THa} is the stress intensity factor at the arrest position for a crack that extended under constant displacement; and K{sub JH} is the stress intensity factor at the onset of crack extension under rising displacement. The apparent crack initiation threshold under constant displacement, K{sub THi}*, and the crack arrest threshold, K{sub THa}, were both found to be non-conservative due to the hydrogen exposure and crack-tip deformation histories associated with typical procedures for sustained-load cracking tests under constant displacement. In contrast, K{sub JH}, which is measured under concurrent rising displacement and hydrogen gas exposure, provides a more conservative hydrogen-assisted fracture threshold that is relevant to structural components in which sub-critical crack extension is driven by internal hydrogen gas pressure.

  16. Ultra-low threshold, electrically pumped quantum dot photonic crystal nanocavity laser

    E-Print Network [OSTI]

    Bryan Ellis; Marie Mayer; Gary Shambat; Tomas Sarmiento; James Harris; Eugene Haller; Jelena Vuckovic

    2011-05-02T23:59:59.000Z

    Efficient, low threshold, and compact semiconductor laser sources are being investigated for many applications in high-speed communications, information processing, and optical interconnects. The best edge-emitting and vertical cavity surface-emitting lasers (VCSELs) have thresholds on the order of 100 \\muA[1,2] but dissipate too much power to be practical for many applications, particularly optical interconnects[3]. Optically pumped photonic crystal (PC) nanocavity lasers represent the state of the art in low-threshold lasers[4,5]; however, in order to be practical, techniques to electrically pump these structures must be developed. Here we demonstrate a quantum dot photonic crystal nanocavity laser in gallium arsenide pumped by a lateral p-i-n junction formed by ion implantation. Continuous wave lasing is observed at temperatures up to 150 K. Thresholds of only 181 nA at 50 K and 287 nA at 150 K are observed - the lowest thresholds ever observed in any type of electrically pumped laser.

  17. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, Daniel J. (Wheeling, IL); Cha, Yung S. (Darien, IL)

    1999-01-01T23:59:59.000Z

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  18. Passive fault current limiting device

    DOE Patents [OSTI]

    Evans, D.J.; Cha, Y.S.

    1999-04-06T23:59:59.000Z

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

  19. Threshold law for electron impact ionization in the model of Temkin and Poet

    SciTech Connect (OSTI)

    Macek, J.H. [Univ. of Tennessee, Knoxville, TN (United States)

    1996-05-01T23:59:59.000Z

    The angle-Sturmian theory is used to derive the threshold law for ionization of atomic hydrogen by electron impact in the model of Temkin and Poet. In this model, the exact electron-electron interaction is replaced by its monopole term. As for Wannier`s theory with the real interaction, ionization occurs only for electrons that start out nearly equidistant from the proton. Because there is a high propensity for one electron to be captured into a bound state, ionization is strongly suppressed, giving rise to a threshold law of the form {sigma} {proportional_to} exp[{minus}aE{sup {minus}1/6} + bE{sup 1/6}], where a and b are constants. The exponential law appears to be the quantal counterpart of the classical offset of the ionization threshold. Relative energy distribution are computed and found to favor configurations with unequal energy sharing.

  20. Adapting to a Changing Environment: Non-obvious Thresholds in Multi-Scale Systems

    E-Print Network [OSTI]

    Clare Perryman; Sebastian Wieczorek

    2014-07-09T23:59:59.000Z

    Many natural and technological systems fail to adapt to changing external conditions and move to a different state if the conditions vary too fast. Such "non-adiabatic" processes are ubiquitous, but little understood. We identify these processes with a new nonlinear phenomenon---an intricate threshold where a forced system fails to adiabatically follow a changing stable state. In systems with multiple time-scales such thresholds are generic, but non-obvious, meaning they cannot be captured by traditional stability theory. Rather, the phenomenon can be analysed using concepts from modern singular perturbation theory: folded singularities and canard trajectories, including composite canards. Thus, non-obvious thresholds should explain the failure to adapt to a changing environment in a wide range of multi-scale systems including: tipping points in the climate system, regime shifts in ecosystems, excitability in nerve cells, adaptation failure in regulatory genes, and adiabatic switching in technology.

  1. Threshold effects on renormalization group running of neutrino parameters in the low-scale seesaw model

    E-Print Network [OSTI]

    Johannes Bergstrom; Tommy Ohlsson; He Zhang

    2011-04-04T23:59:59.000Z

    We show that, in the low-scale type-I seesaw model, renormalization group running of neutrino parameters may lead to significant modifications of the leptonic mixing angles in view of so-called seesaw threshold effects. Especially, we derive analytical formulas for radiative corrections to neutrino parameters in crossing the different seesaw thresholds, and show that there may exist enhancement factors efficiently boosting the renormalization group running of the leptonic mixing angles. We find that, as a result of the seesaw threshold corrections to the leptonic mixing angles, various flavor symmetric mixing patterns (e.g., bi-maximal and tri-bimaximal mixing patterns) can be easily accommodated at relatively low energy scales, which is well within the reach of running and forthcoming experiments (e.g., the LHC).

  2. First passage times in integrate-and-fire neurons with stochastic thresholds

    E-Print Network [OSTI]

    Braun, Wilhelm; Thul, Rüdiger

    2015-01-01T23:59:59.000Z

    We consider a leaky integrate--and--fire neuron with deterministic subthreshold dynamics and a firing threshold that evolves as an Ornstein-Uhlenbeck process. The formulation of this minimal model is motivated by the experimentally observed widespread variation of neural firing thresholds. We show numerically that the mean first passage time can depend non-monotonically on the noise amplitude. For sufficiently large values of the correlation time of the stochastic threshold the mean first passage time is maximal for non-vanishing noise. We provide an explanation for this effect by analytically transforming the original model into a first passage time problem for Brownian motion. This transformation also allows for a perturbative calculation of the first passage time histograms. In turn this provides quantitative insights into the mechanisms that lead to the non-monotonic behaviour of the mean first passage time. The perturbation expansion is in excellent agreement with direct numerical simulations. The approa...

  3. Temperature dependence of the threshold current for InGaAlP visible laser diodes

    SciTech Connect (OSTI)

    Ishikawa, M.; Shiozawa, H.; Itaya, K.; Hatakoshi, G.; Uematsu, Y. (Research and Development Center, Toshiba Corp., Saiwai-ku, Kawasaki 210 (JP))

    1991-01-01T23:59:59.000Z

    The temperature dependence of the threshold current for InGaAlP visible light laser diodes is investigated from the aspect of gain-current characteristics. The cavity length dependence of light output power versus current characteristic was evaluated for a 40 {mu}m width InGaP-InBaAlP broad-stripe laser in the temperature range between {minus} 70 and 90{degrees} C, which had about a 670 nm oscillation wavelength at room temperature. The threshold-current density dependence on the cavity length shows that a linear-gain approximation is suitable for this system. A minimum threshold-current density at 860 A/cm{sup 2} was achieved at room temperature with a cavity length of 1160 {mu}m, which is the lowest value ever reported for this material. The linear-gain parameters {beta} and {ital J}{sub 0} depended on the temperature with the characteristic temperature of about 200 K, which is considered to be the intrinsic characteristic temperature of the threshold current for this active-layer material. The internal quantum efficiency, derived from the cavity length dependence of the differential quantum efficiency, decreased in the temperature range higher than {minus}10{degrees} C, which affected the excess threshold-current increase and the decrease in the characteristic temperature at this temperature range. The theoretical calculation, considering a one-dimensional band structure model, showed that this excess increase of the threshold current was found to be attributed to the electron overflow current into the p-type cladding layer.

  4. Page 1 of 14 UNSW Foundation Limited

    E-Print Network [OSTI]

    New South Wales, University of

    , Coca-Cola Amatil Limited and Ingeus Limited. David is Chairman of the National E-Health Transition

  5. Threshold law for the triplet state for electron-impact ionization in the Temkin-Poet model

    SciTech Connect (OSTI)

    Ihra, W.; Mota-Furtado, F.; OMahony, P.F. [Department of Mathematics, Royal Holloway, University of London, Egham, Surrey TW200EX (United Kingdom)] [Department of Mathematics, Royal Holloway, University of London, Egham, Surrey TW200EX (United Kingdom); Macek, J.H. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1501 (United States)] [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1501 (United States); [Oak Ridge National Laboratory, Post Office Box 2009 Oak Ridge, Tennessee 37831 (United States)

    1997-04-01T23:59:59.000Z

    We derive the analytical threshold behavior for the triplet cross section for electron-impact ionization in the Temkin-Poet model. The analytical results indicate that the most recent numerical calculations may fail to reproduce the correct threshold behavior in an energy regime below about E=0.1 a.u. We also present an analytical expression for the energy distribution of the two electrons near threshold. {copyright} {ital 1997} {ital The American Physical Society}

  6. Experimental study on GaP surface damage threshold induced by a high repetition rate femtosecond laser

    SciTech Connect (OSTI)

    Li Yi; Liu Feng; Li Yanfeng; Chai Lu; Xing Qirong; Hu Minglie; Wang Chingyue

    2011-05-01T23:59:59.000Z

    The surface damage threshold of undoped bulk <110> GaP induced by a high repetition rate femtosecond pulse at 1040 nm with a duration of 61 fs was studied. The threshold value was obtained by a linear fit of the incident single pulse fluence and was confirmed with a breakdown test around the threshold level. The result will be useful in high intensity, high repetition rate laser applications and ultrafast processes.

  7. Scaling laws and minimum threshold currents for quantum-confined semiconductor lasers

    SciTech Connect (OSTI)

    Yariv, A.

    1988-09-19T23:59:59.000Z

    Basic scaling laws are derived for bulk, two-dimensional (quantum well) and one-dimensional (quantum wire) semiconductor lasers. Starting from quantum derivation of the optical properties of confined carriers, the dimensional dependencies of the scaling laws are made explicit. Threshold currents of approx.100 and 2--3 ..mu..A are predicted for single quantum well and quantum wire lasers, respectively. The basic considerations of this analysis were used recently to obtain ultralow threshold quantum well lasers (P. L. Derry, A. Yariv, K. Lau, N. Bar-Chaim, K. Lee, and J. Rosenberg, Appl. Phys. Lett. 50, 1773 (1987)).

  8. Low threshold InGaAsP terrace mass transport laser on semi-insulating substrate

    SciTech Connect (OSTI)

    Chen, T.R.; Chiu, L.C.; Yu, K.L.; Koren, U.; Hasson, A.; Margalit, S.; Yariv, A.

    1982-12-15T23:59:59.000Z

    Very low threshold InGaAsP terrace lasers on semi-insulating (SI) InP substrate have been fabricated using the mass transport technique. The fabrication process involves a single-step liquid phase epitaxial (LPE) growth followed by a mass transport of InP at approx.675 /sup 0/C in the presence of an InP cover wafer. Lasers operating in the fundamental transverse mode with smooth far-field patterns and threshold currents as low as 9.5 mA have been obtained.

  9. Difference Thresholds for Timbre Related to Amplitude Spectra of Complex Sounds

    E-Print Network [OSTI]

    Kendall, Roger A.

    1975-01-01T23:59:59.000Z

    Final Investigation 121 11. Treatment x Subjects AN0VA: Data from Table 10 121 12. Scheffe Comparisons: Data from Table 11 123 13. Mean Upper and Lower Thresholds for Timbre 124 14. Treatment x Subjects AN0VA: Upper Threshold Data + from Table 13... can be represented as 360° along the time axis because of the mathematical relation between simple harmonic motion and circular functions. Thus the phase at any point during a cycle may vary between 0° and 360°. The phase angle or phase difference...

  10. Drell-Yan Production at Threshold to Third Order in QCD

    E-Print Network [OSTI]

    Taushif Ahmed; Maguni Mahakhud; Narayan Rana; V. Ravindran

    2014-12-11T23:59:59.000Z

    The recent computation on the full threshold contributions to Higgs boson production at next-to-next-to-next-to-leading order (N$^3$LO) in QCD contains valuable information on the soft gluons resulting from virtual and real emission partonic subprocesses. We use those from the real emissions to obtain the corresponding soft gluon contributions to Drell-Yan production and determine the missing $\\delta(1-z)$ part of the N$^3$LO. The numerical impact of threshold effects demonstrates the importance of our results in the precision study with the Drell-Yan process at the LHC.

  11. Scattering resonances as viscosity limits

    E-Print Network [OSTI]

    Maciej Zworski

    2015-05-04T23:59:59.000Z

    Using the method of complex scaling we show that scattering resonances of $ - \\Delta + V $, $ V \\in L^\\infty_{\\rm{c}} ( \\mathbb R^n ) $, are limits of eigenvalues of $ - \\Delta + V - i \\epsilon x^2 $ as $ \\epsilon \\to 0+ $. That justifies a method proposed in computational chemistry and reflects a general principle for resonances in other settings.

  12. Electron-Nuclear Energy Sharing in Above-Threshold Multiphoton Dissociative Ionization of H2

    E-Print Network [OSTI]

    Thumm, Uwe

    Electron-Nuclear Energy Sharing in Above-Threshold Multiphoton Dissociative Ionization of H2 J. Wu­4], where the photon energy is shared by the freed electrons and the nuclear fragments. For the molecular ionization [10­15], and the imaging of inter- nuclear distance using nuclear kinetic energy release spec- tra

  13. Effects of creatine loading on electromyographic fatigue threshold during cycle ergometry in college-aged women

    E-Print Network [OSTI]

    Smith, Abbie E.; Walter, Ashley A.; Herda, Trent J.; Ryan, Eric D.; Moon, Jordan R.; Cramer, Joel T.; Stout, Jeffrey R.

    2007-01-01T23:59:59.000Z

    The purpose of this study was to examine the effects of 5 days of Creatine (Cr) loading on the electromyographic fatigue threshold (EMGFT) in college-aged women. Fifteen healthy college-aged women (mean ± SD = 22.3 ± 1.7 yrs) volunteered...

  14. Dense granular ows: two-particle argument accounts for friction-like constitutive law with threshold

    E-Print Network [OSTI]

    Recanati, Catherine

    robust scaling behav- iors in various ow geomerties for dry grains, whether frictional or not [2, 4Dense granular ows: two-particle argument accounts for friction-like constitutive law a constitutive law that exhibits a ow threshold expressed as a #12;nite e#11;ective friction at ow onset

  15. Dense granular flows: two-particle argument accounts for friction-like constitutive law with threshold

    E-Print Network [OSTI]

    Boyer, Edmond

    Dense granular flows: two-particle argument accounts for friction-like constitutive law that exhibits a flow threshold expressed as a finite effective friction at flow onset. The value 83.10.Gr 83.60.La I. INTRODUCTION Dense flows of dry granular materials and granular pastes is still

  16. Determination of energy thresholds on an artificial retina using a multiple-pulsed laser 

    E-Print Network [OSTI]

    Stephenson, Albert David

    1999-01-01T23:59:59.000Z

    This study is focused on determining single and multiple pulse ED?? for laser pulses of 200 ns duration. Energy thresholds in this experiment were determined on an artificial retina, for a variety of pulse widths and spot sizes. Due to numerous...

  17. TQuEST: Threshold Query Execution for Large Sets of Time Series

    E-Print Network [OSTI]

    Kriegel, Hans-Peter

    TQuEST: Threshold Query Execution for Large Sets of Time Series Johannes AÃ?falg, Hans-Peter Kriegel TQuEST, a powerful query processor for time series databases. TQuEST supports a novel but very useful times. 1 Introduction In this paper, we present TQuEST, a powerful analysis tool for time series

  18. Perspective Aligand-receptor signaling threshold model of stem cell differentiation control

    E-Print Network [OSTI]

    Zandstra, Peter W.

    Perspective Aligand-receptor signaling threshold model of stem cell differentiation control and theoretical framework for pre- dicting and controlling the outcome of HSC stimulation by exogenous cytokines or by extracellular matrix- or cell-bound cyto- kine presentation. According to such a model, when the relevant ligand

  19. A threshold area ratio of organic to conventional agriculture causes recurrent pathogen outbreaks in organic agriculture

    E-Print Network [OSTI]

    Kolokolnikov, Theodore

    A threshold area ratio of organic to conventional agriculture causes recurrent pathogen outbreaks in organic agriculture S. Adl a, , D. Iron b , T. Kolokolnikov b a Department of Biology, Dalhousie Fungal spores Organic agriculture Pathogen dispersal Conventional agriculture uses herbicides, pesticides

  20. An Algorithm to Learn ReadOnce Threshold Formulas, and some Generic Transformations between Learning Models

    E-Print Network [OSTI]

    Eckmiller, Rolf

    An Algorithm to Learn Read­Once Threshold Formulas, and some Generic Transformations between@cpsc.ucalgary.ca Thomas R. Hancock y Siemens Corporate Research, Inc. 755 College Road East Princeton, NJ 08540 e­mail: hancock@learning.scr.siemens.com Lisa Hellerstein z Department of EECS Northwestern University 2145

  1. An Algorithm to Learn Read-Once Threshold Formulas, and some Generic Transformations between Learning Models

    E-Print Network [OSTI]

    Eckmiller, Rolf

    An Algorithm to Learn Read-Once Threshold Formulas, and some Generic Transformations between. Hancocky Siemens Corporate Research, Inc. 755 College Road East Princeton, NJ 08540 e-mail: hancock@learning.scr.siemens of generic transformations that can be used to convert an algorithm in one learning model into an algorithm

  2. Embedded epitaxial growth of low-threshold GaInAsP/InP injection lasers

    SciTech Connect (OSTI)

    Chen, P.C.; Yu, K.L.; Margalit, S.; Yariv, A.

    1981-03-01T23:59:59.000Z

    Single-growth liquid-phase embedded epitaxy in the GaInAsP/InP system is described, and a new heterostructure laser is grown using this technique. These lasers exhibit excellent current and optical confinement. Threshold currents as low as 45 mA are achieved for a laser with 4-..mu..m-wide active region.

  3. L-H Transition Threshold; Orbit Loss Theory Revisited J.A. Heikkinen1

    E-Print Network [OSTI]

    L-H Transition Threshold; Orbit Loss Theory Revisited J.A. Heikkinen1 , T.P. Kiviniemi2 , T. Kurki of different theoretical models to explain a transition to an H-mode in toroidal plasmas have been suggested [1]. Common to most of them is that a strong shear in ExB rotation is required at the transition conditions

  4. Adaptive Threshold Spike Detection using Stationary Wavelet Transform for Neural Recording Implants

    E-Print Network [OSTI]

    Mason, Andrew

    to optimize power consumption. The system was designed in 130nm CMOS and shown to occupy 0.082 mm2. Such a system must operate with very low power and occupy minimal area in order to facilitate implantationAdaptive Threshold Spike Detection using Stationary Wavelet Transform for Neural Recording Implants

  5. An Efficient Threshold-Based Power Management Mechanism for Heterogeneous Soft Real-Time Clusters

    E-Print Network [OSTI]

    Lu, Ying

    An Efficient Threshold-Based Power Management Mechanism for Heterogeneous Soft Real-Time Clusters {lwang, ylu}@cse.unl.edu Abstract With growing cost of electricity, the power management of server proposes an efficient algorithm for power management of heterogeneous soft real-time clusters. It is built

  6. EnergySmart: Toward Energy-Efficient Manycores for Near-Threshold Computing

    E-Print Network [OSTI]

    Torrellas, Josep

    and static energy. According to initial estimates [7, 13], NTC can decrease the energy per operationEnergySmart: Toward Energy-Efficient Manycores for Near-Threshold Computing Ulya R. Karpuzcu on-chip voltage (Vdd) domains. However, this paper finds that such an approach is energy inefficient

  7. Organic thin film devices with stabilized threshold voltage and mobility, and method for preparing the devices

    DOE Patents [OSTI]

    Nastasi, Michael Anthony; Wang, Yongqiang; Fraboni, Beatrice; Cosseddu, Piero; Bonfiglio, Annalisa

    2013-06-11T23:59:59.000Z

    Organic thin film devices that included an organic thin film subjected to a selected dose of a selected energy of ions exhibited a stabilized mobility (.mu.) and threshold voltage (VT), a decrease in contact resistance R.sub.C, and an extended operational lifetime that did not degrade after 2000 hours of operation in the air.

  8. Measurement of T20,,90... in the 1 He reaction below deuteron breakup threshold

    E-Print Network [OSTI]

    Knutson, Lynn

    to the parametrization of the tensor force in the trinucleon system. The T20 analyzing power was measured at an incidentMeasurement of T20,,90°... in the 1 H,,d, ...3 He reaction below deuteron breakup threshold K. P, Wisconsin 53706 Received 10 November 1995 The tensor analyzing powers of the 1 H(d, )3 He reaction

  9. Threshold phenomena and complexity: a statistical physics analysis of the random

    E-Print Network [OSTI]

    Duxbury, Phillip M.

    Threshold phenomena and complexity: a statistical physics analysis of the random Satis#12;ability problem. R#19;emi Monasson 1 Laboratoire de Physique Th#19;eorique de l'ENS, 75005 Paris. Abstract designed by physicists to deal with optimization or decision problems in an accessible language

  10. Efficient generic on-line/off-line (threshold) signatures without key exposure q

    E-Print Network [OSTI]

    Kim, Kwangjo

    security requirements. Ó 2008 Elsevier Inc. All rights reserved. 1. Introduction The notion of on-line/off-line manufacturing process or as a background computation whenever the card is connected to power, and the on-lineEfficient generic on-line/off-line (threshold) signatures without key exposure q Xiaofeng Chen a

  11. USE OF A SPATIALLY ADAPTIVE THRESHOLDING METHOD FOR THE CONDITION MONITORING OF A WIND TURBINE GEARBOX

    E-Print Network [OSTI]

    Boyer, Edmond

    USE OF A SPATIALLY ADAPTIVE THRESHOLDING METHOD FOR THE CONDITION MONITORING OF A WIND TURBINE.Antoniadou@sheffield.ac.uk ABSTRACT Condition monitoring of wind turbine gearboxes is an important practice in order to de- termine the state of the wind turbine drivetrain. In this way reparative actions could be taken whenever needed

  12. Determination of energy thresholds on an artificial retina using a multiple-pulsed laser

    E-Print Network [OSTI]

    Stephenson, Albert David

    1999-01-01T23:59:59.000Z

    This study is focused on determining single and multiple pulse ED?? for laser pulses of 200 ns duration. Energy thresholds in this experiment were determined on an artificial retina, for a variety of pulse widths and spot sizes. Due to numerous...

  13. ccsd00000619 Phenomenology of the pp ! pp reaction close to threshold

    E-Print Network [OSTI]

    to threshold A. Delo#11; #3; Institute for Nuclear Studies, Ho_za 69, 00-681 Warsaw, Poland (Dated: September 22, 2003) The recent high statistics measurement of the pp ! pp#17; reaction at an excess energy Q=15 on-shell approximation in the enhancement factor and by allowing for a linear energy dependence

  14. The Benard-Von Karman instability : an experimental study near the threshold

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    alternately to form a double row of oppositely signed vortices : the Benard-Von Karman vortex street. PreviousL-483 The Benard-Von Karman instability : an experimental study near the threshold C. Mathis, M features ofthe flow have been known since the work of Benard [3] or Von Karman [4]. For Re 4 the flow

  15. 2[r arrow][ital n] threshold production at the tree level

    SciTech Connect (OSTI)

    Brown, L.S.; Zhai, C. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1993-06-15T23:59:59.000Z

    The threshold behavior of a theory with two coupled scalar fields [chi] and [phi] is investigated. We compute the amplitude for two on-mass-shell [chi] particles to produce an arbitrary number of [phi] particles at rest in the tree approximation.

  16. Total cross section for p + p r arrow p + p +. pi. sup 0 near threshold

    SciTech Connect (OSTI)

    Miller, G.A.; Sauer, P.U. (Department of Physics, FM-15, University of Washington, Seattle, Washington (USA))

    1991-11-01T23:59:59.000Z

    We compare a phenomenology of {pi}{sup 0} production in {ital p}-{ital p} scattering with recent Indiana University Cyclotron Facility data for energies near threshold. The computed magnitude of the cross section is too small by a factor of about 5, even though the energy dependence is satisfactorily described.

  17. NetTRUST: mixed NETworks Trust infrastRUcture baSed on Threshold cryptography

    E-Print Network [OSTI]

    Boyer, Edmond

    NetTRUST: mixed NETworks Trust infrastRUcture baSed on Threshold cryptography Mawloud Omar Re and the performance evaluation prove the adequacy of this solution to mixed networks architectures. Keywords to military applications), but the combination of ad-hoc networks with infrastructure based networks

  18. Upper limit of the total cross section for the pn --> pn eta' reaction

    E-Print Network [OSTI]

    J. Klaja; P. Moskal; S. D. Bass; E. Czerwinski; R. Czyzykiewicz; D. Gil; D. Grzonka; T. Johansson; B. Kamys; A. Khoukaz; P. Klaja; W. Krzemien; W. Oelert; B. Rejdych; J. Ritman; T. Sefzick; M. Siemaszko; M. Silarski; J. Smyrski; A. Taschner; M. Wolke; P. Wustner; J. Zdebik; M. Zielinski; W. Zipper

    2010-03-23T23:59:59.000Z

    The upper limit of the total cross section for the pn --> pn eta' reaction has been determined near the kinematical threshold in the excess energy range from 0 to 24 MeV. The measurement was performed using the COSY-11 detector setup, a deuteron cluster target, and the proton beam of COSY with a momentum of 3.35 GeV/c. The energy dependence of the upper limit of the cross section was extracted exploiting the Fermi momenta of nucleons inside the deuteron. Comparison of the determined upper limit of the ratio R_eta' = sigma(pn --> pn eta') / sigma(pp --> pp eta') with the corresponding ratio for eta-meson production does not favor the dominance of the N*(1535) resonance in the production process of the eta' meson and suggests nonidentical production mechanisms for eta and eta' mesons.

  19. $J/?$ suppression in the threshold model at RHIC and LHC energy

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2007-11-14T23:59:59.000Z

    In the QGP based threshold model \\cite{Blaizot:2000ev,Blaizot:1996nq}, in addition to the normal nuclear absorption, $J/\\psi$'s are subjected to an 'anomalous' suppression such that above a threshold density $n_{J/\\psi}$, all the $J/\\psi$'s are melted. In the threshold model we have analysed the recent PHENIX data on the centrality dependence of $J/\\psi$ suppression in Au+Au collisions at RHIC. Feedback from decay of the state $\\chi$ is accounted for. $J/\\psi$'s are anomalously suppressed above a threshold density, $n_{J/\\psi}=3.57\\pm 0.17$ $fm^{-2}$. Threshold density for anomalous suppression of the state $\\chi$ is uncertain to a large extent, $n_\\chi=0.32 \\pm 0.32$ $fm^{-2}$. The fraction $F$ of the state $\\chi$ can not be determined unambiguously, depending on the nuclear absorption, it can vary from 20% to 40%. We have also predicted for the suppression in Pb+Pb collisions at LHC energy. In central Pb+Pb collisions, $J/\\psi$'s are suppressed by a factor of 3-4. Suppression pattern is rather similar to that in Au+Au collisions, if not slighty less in central collisions. Using the PHENIX data on the participant number dependence of the Bjorken energy density, we have also estimated the QGP formation time. For critical temperature $T_c$=192 MeV, estimated QGP formation time ranges between 0.07-0.09 fm/c.

  20. Experimental determination of transparency current density and estimation of the threshold current of semiconductor quantum well lasers

    SciTech Connect (OSTI)

    Chen, T.R.; Eng, L.E.; Zhuang, Y.H.; Yariv, A. (California Institute of Technology, Pasadena, California 91125 (US))

    1990-03-12T23:59:59.000Z

    An experimental method for determining the transparency current density of semiconductor quantum well lasers is demonstrated in a strained-layer InGaAs/GaAs single quantum well laser system. The experimental results are then used as a practical guide to the study of ultralow threshold lasers. A threshold current as low as 0.75 mA is observed.

  1. Wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser

    SciTech Connect (OSTI)

    Chow, W.W.; Schneider, R.P. Jr.; Lott, J.A.; Choquette, K.D. (Sandia National Laboratories, Albuquerque, New Mexico 87185-0350 (United States))

    1994-07-11T23:59:59.000Z

    The wavelength dependence of the threshold in an InGaP-InAlGaP vertical cavity surface emitting laser is investigated using a microscopic theory of the semiconductor gain medium. Good agreement is found between experiment and theory for the minimum threshold lasing wavelength for a range of laser structures.

  2. Summary of Dissolved Concentration Limits

    SciTech Connect (OSTI)

    Yueting Chen

    2001-06-11T23:59:59.000Z

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  3. Fundamental Limits to Cellular Sensing

    E-Print Network [OSTI]

    Pieter Rein ten Wolde; Nils B. Becker; Thomas E. Ouldridge; A. Mugler

    2015-05-25T23:59:59.000Z

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this noise extrinsic to the cell as much as possible. These networks, however, are also stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, and then how downstream signaling pathways integrate the noise in the receptor state; we will discuss how the number of receptors, the receptor correlation time, and the effective integration time together set a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes of resources---receptors and their integration time, readout molecules, energy---and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade-off between accuracy and energetic cost.

  4. Waste tank characterization sampling limits

    SciTech Connect (OSTI)

    Tusler, L.A.

    1994-09-02T23:59:59.000Z

    This document is a result of the Plant Implementation Team Investigation into delayed reporting of the exotherm in Tank 241-T-111 waste samples. The corrective actions identified are to have immediate notification of appropriate Tank Farm Operations Shift Management if analyses with potential safety impact exceed established levels. A procedure, WHC-IP-0842 Section 12.18, ``TWRS Approved Sampling and Data Analysis by Designated Laboratories`` (WHC 1994), has been established to require all tank waste sampling (including core, auger and supernate) and tank vapor samples be performed using this document. This document establishes levels for specified analysis that require notification of the appropriate shift manager. The following categories provide numerical values for analysis that may indicate that a tank is either outside the operating specification or should be evaluated for inclusion on a Watch List. The information given is intended to translate an operating limit such as heat load, expressed in Btu/hour, to an analysis related limit, in this case cesium-137 and strontium-90 concentrations. By using the values provided as safety flags, the analytical laboratory personnel can notify a shift manager that a tank is in potential violation of an operating limit or that a tank should be considered for inclusion on a Watch List. The shift manager can then take appropriate interim measures until a final determination is made by engineering personnel.

  5. Gradient limits and SCRF performance.

    SciTech Connect (OSTI)

    Norem, J.; Pellin, M.

    2007-01-01T23:59:59.000Z

    Superconducting rf gradients are limited by a number of mechanisms, among them are field emission, multipactor, Lorentz detuning, global and local heating, quench fields, Q-Slope, assembly defects, and overall power use. We describe how each of these mechanisms interacts with the cavity fields and show how significant improvements may be possible assuming improvements in control over the cavity surface. New techniques such as Atomic Layer Deposition (ALD), the use of layered composites, Gas Cluster Ion Beam (GCIB) smoothing and Dry Ice Cleaning (DIC) have been proposed as ways to control the surface.

  6. Dose Limits | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 1112011AT&T,Office of Policy,Policy ActDetroit7471 FederalDonna Friend Donna FriendLimits

  7. Ablamp Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2,AUDIT REPORT Americium/Curium Vitrification4th DayANVAblamp Limited Jump

  8. Novacem Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |JilinLuOpenNorth AmericaNorthwest Rural PubNova AlincaNovacem Limited

  9. Bioethanol Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty EditCalifornia: EnergyAvignon,Belcher HomesLyons Biomass FacilityBioethanol Limited

  10. Lysanda Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup |JilinLu an Group Jump to: navigation,LushuiLyme, NewLyonLysanda Limited

  11. Bound and resonance states of the dipolar anion of hydrogen cyanide: competition between threshold effects and rotation in an open quantum system

    E-Print Network [OSTI]

    K. Fossez; N. Michel; W. Nazarewicz; M. P?oszajczak; Y. Jaganathen

    2014-10-24T23:59:59.000Z

    Bound and resonance states of the dipole-bound anion of hydrogen cyanide HCN$^-$ are studied using a non-adiabatic pseudopotential method and the Berggren expansion technique involving bound states, decaying resonant states, and non-resonant scattering continuum. We devise an algorithm to identify the resonant states in the complex energy plane. To characterize spatial distributions of electronic wave functions, we introduce the body-fixed density and use it to assign families of resonant states into collective rotational bands. We find that the non-adiabatic coupling of electronic motion to molecular rotation results in a transition from the strong-coupling to weak-coupling regime. In the strong coupling limit, the electron moving in a subthreshold, spatially extended halo state follows the rotational motion of the molecule. Above the ionization threshold, electron's motion in a resonance state becomes largely decoupled from molecular rotation. Widths of resonance-band members depend primarily on the electron orbital angular momentum.

  12. Mixing of partial waves near B*B?* threshold in e?e? annihilation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Xin; Voloshin, M. B.

    2013-05-01T23:59:59.000Z

    We consider the production of B*B?* meson pairs in e?e? annihilation near the threshold. The rescattering due to pion exchange between the mesons results in a mixing between three partial wave amplitudes: two P-wave amplitudes with the total spin of the meson pair S=0 and S=2 and an F-wave amplitude. The mixing due to pion exchange with a low momentum transfer is calculable up to c.m. energy E?15–20 MeV above the threshold. We find that the P–F mixing is numerically quite small in this energy range, while the mixing of the two P-wave amplitudes is rapidly changing with energy and can reach of order one at such low energies.

  13. Direct Dose Consequences Due to DOE-STD-1027 Threshold Values

    SciTech Connect (OSTI)

    Hochhalter, E Eugene; Durante, Richard Paul; Walker, Jonathon Bill

    2001-06-01T23:59:59.000Z

    The purpose of this paper is to discuss the potential direct dose consequences to facility workers and/or co-located workers from a Hazard Category 2 or 3 nuclear facility or a less than Hazard Category 3 radiological inventory. At the Idaho National Engineering and Environmental Laboratory (INEEL), the safety analysis for several Hazard Category 3 nuclear facilities had to be revisited and the direct dose consequences associated with the facility radiological inventory had to be analyzed and incorporated into the safety analysis. This additional safety analysis was required because it was assumed that for a nuclear facility operating with radiological inventories between the Hazard Category 3 threshold quantities as a lower bounds and less the Hazard Category 2 threshold quantities as an upper bounds, the risk to the facility worker and/or co-located worker was within the INEEL Evaluation Guidelines for radiological exposures.

  14. The effect of a percolation threshold in the Kozeny-Carman relation

    SciTech Connect (OSTI)

    Mavko, G.; Nur, A. [Stanford Univ., CA (United States). Dept. of Geophysics] [Stanford Univ., CA (United States). Dept. of Geophysics

    1997-09-01T23:59:59.000Z

    One of the most important properties of reservoir rocks, and perhaps the most difficult to predict, is permeability. Laboratory studies have shown that permeability depends on a long list of parameters: porosity, pore size and shape, clay content, stress, pore pressure, fluid type, saturation--a nearly overwhelming complexity. In spite of this, the essential behavior can often be expressed successfully using the remarkably simple Kozeny-Carman relation. Numerous authors have studied the role of percolation in both electrical and fluid transport, in particular the details of transport in the neighborhood of the percolation threshold. The goal here is to show that by including the percolation threshold, in a very simple way, in the Kozeny-Carman relation, the derived third-power dependence on porosity can be retained while accurately fitting the observed permeability in certain well sorted materials--thus extending the range of this already useful tool.

  15. Vibrational Feshbach resonances in near threshold HOCO{sup -} photodetachment: a theoretical study

    SciTech Connect (OSTI)

    Miyabe, Shungo; Haxton, Dan; Lawler, Keith; Orel, Ann; McCurdy, Bill; Rescigno, Tom

    2011-03-02T23:59:59.000Z

    The results of a theoretical study of HOCO{sup ?} photodetachment are presented, with a view toward understanding the origin of two peaks observed by Lu and Continetti (Phys. Rev. Lett. 99, 113005 (2007)) in the photoelectron kinetic energy spectrum very close to threshold. It is shown that the peaks can be attributed to vibrational Feshbach resonances of dipole-bound trans-HOCO{sup ?}, and not s- and p-wave shape resonances as previously assumed. Fixed-nuclei variational electron-HOCO scattering calculations are used to compute photodetachment cross sections and laboratory-frame photoelectron angular distributions. The calculations show a broad A??(#25;{pi}*)-shape resonance several eV above threshold.

  16. Interference Oscillations in the Angular Distribution of Laser-Ionized Electrons near Ionization Threshold

    SciTech Connect (OSTI)

    Arbo, D.G.; Yoshida, S.; Persson, E.; Dimitriou, K.I.; Burgdoerfer, J. [Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria)

    2006-04-14T23:59:59.000Z

    We analyze the two-dimensional momentum distribution of electrons ionized by few-cycle laser pulses in the transition regime from multiphoton absorption to tunneling by solving the time-dependent Schroedinger equation and by a classical-trajectory Monte-Carlo simulation with tunneling (CTMC-T). We find a complex two-dimensional interference pattern that resembles above threshold ionization (ATI) rings at higher energies and displays Ramsauer-Townsend-type diffraction oscillations in the angular distribution near threshold. CTMC-T calculations provide a semiclassical explanation for the dominance of selected partial waves. While the present calculation pertains to hydrogen, we find surprising qualitative agreement with recent experimental data for rare gases [A. Rudenko et al., J. Phys. B 37, L407 (2004)].

  17. Sub-threshold $\\phi$ and $\\Xi^-$ production by high mass resonances with UrQMD

    E-Print Network [OSTI]

    Steinheimer, Jan

    2015-01-01T23:59:59.000Z

    We present a possible explanation for the deep sub-threshold, $\\phi$ and $\\Xi^-$ production yields measured with the HADES experiment in Ar+KCl reactions at $E_{\\mathrm{lab}}=1.76$ A GeV and present predictions for Au+Au reactions at $E_{\\mathrm{lab}}=1.23$ A GeV. To explain the surprisingly high yields of $\\phi$ and $\\Xi^-$ hadrons we propose new decay channels for high mass baryon resonances. These new decay channels are constrained by elementary $\\mathrm{p+p}\\rightarrow \\mathrm{p+p+}\\phi$ cross sections, and $\\Xi^-$ production in p+Nb. Based on the fits to the elementary reactions one obtains a satisfactorily description of $\\phi$ and $\\Xi^-$ production in deep sub-threshold Ar+KCl reactions. The results implicate that no new medium effects are required to describe the rare strange particle production data in low energy nuclear collisions.

  18. Direct Measurement of the Bubble Nucleation Energy Threshold in a CF3I Bubble Chamber

    E-Print Network [OSTI]

    Behnke, E; Brice, S J; Broemmelsiek, D; Collar, J I; Cooper, P S; Crisler, M; Dahl, C E; Fustin, D; Hall, J; Harnish, C; Levine, I; Lippincott, W H; Moan, T; Nania, T; Neilson, R; Ramberg, E; Robinson, A E; Sonnenschein, A; Vázquez-Jáuregui, E; Rivera, R A; Uplegger, L

    2013-01-01T23:59:59.000Z

    We have directly measured the energy threshold and efficiency for bubble nucleation from iodine recoils in a CF3I bubble chamber in the energy range of interest for a dark matter search. These interactions cannot be probed by standard neutron calibration methods, so we develop a new technique by observing the elastic scattering of 12 GeV/c negative pions. The pions are tracked with a silicon pixel telescope and the reconstructed scattering angle provides a measure of the nuclear recoil kinetic energy. The bubble chamber was operated with a nominal threshold of (13.6+-0.6) keV. Interpretation of the results depends on the response to fluorine and carbon recoils, but in general we find agreement with the predictions of the classical bubble nucleation theory. This measurement confirms the applicability of CF3I as a target for spin-independent dark matter interactions and represents a novel technique for calibration of superheated fluid detectors.

  19. Near Threshold Neutral Pion Electroproduction at High Momentum Transfers and Generalized Form Factors

    E-Print Network [OSTI]

    P. Khetarpal; P. Stoler; I. G. Aznauryan; V. Kubarovsky; K. P. Adhikari; D. Adikaram; M. Aghasyan; M. J. Amaryan; M. D. Anderson; S. Anefalos Pereira; M. Anghinolfi; H. Avakian; H. Baghdasaryan; J. Ball; N. A. Baltzell; M. Battaglieri; V. Batourine; I. Bedlinskiy; A. S. Biselli; J. Bono; S. Boiarinov; W. J. Briscoe; W. K. Brooks; V. D. Burkert; D. S. Carman; A. Celentano; G. Charles; P. L. Cole; M. Contalbrigo; V. Crede; A. D'Angelo; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; D. Doughty; M. Dugger; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; P. Eugenio; G. Fedotov; S. Fegan; R. Fersch; J. A. Fleming; A. Fradi; M. Y. Gabrielyan; M. Garçon; N. Gevorgyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; W. Gohn; E. Golovatch; R. W. Gothe; K. A. Griffioen; B. Guegan; M. Guidal; L. Guo; K. Hafidi; H. Hakobyan; C. Hanretty; N. Harrison; K. Hicks; D. Ho; M. Holtrop; C. E. Hyde; Y. Ilieva; D. G. Ireland; B. S. Ishkhanov; E. L. Isupov; H. S. Jo; K. Joo; D. Keller; M. Khandaker; A. Kim; W. Kim; F. J. Klein; S. Koirala; A. Kubarovsky; S. V. Kuleshov; N. D. Kvaltine; S. Lewis; K. Livingston; H. Y. Lu; I. J. D. MacGregor; Y. Mao; D. Martinez; M. Mayer; B. McKinnon; C. A. Meyer; T. Mineeva; M. Mirazita; V. Mokeev; R. A. Montgomery; H. Moutarde; E. Munevar; C. Munoz Camacho; P. Nadel-Turonski; R. Nasseripour; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; A. I. Ostrovidov; L. L. Pappalardo; R. Paremuzyan; K. Park; S. Park; E. Pasyuk; E. Phelps; J. J. Phillips; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; A. J. R. Puckett; B. A. Raue; G. Ricco; D. Rimal; M. Ripani; G. Rosner; P. Rossi; F. Sabatié; M. S. Saini; C. Salgado; N. A. Saylor; D. Schott; R. A. Schumacher; E. Seder; H. Seraydaryan; Y. G. Sharabian; G. D. Smith; D. I. Sober; D. Sokhan; S. S. Stepanyan; S. Stepanyan; I. I. Strakovsky; S. Strauch; M. Taiuti; W. Tang; C. E. Taylor; S. Tkachenko; M. Ungaro; B. Vernarsky; H. Voskanyan; E. Voutier; N. K. Walford; L. B. Weinstein; D. P. Weygand; M. H. Wood; N. Zachariou; J. Zhang; Z. W. Zhao; I. Zonta

    2012-11-29T23:59:59.000Z

    We report the measurement of near threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range $Q^2$ from 2 to 4.5 GeV$^2$ and $W$ from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles $E_{0+}$ and $S_{0+}$ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors $G_1^{\\pi^0 p}(Q^2)$ and $G_2^{\\pi^0 p}(Q^2)$. The data are compared to these generalized form factors and the results for $G_1^{\\pi^0 p}(Q^2)$ are found to be in good agreement with the LCSR predictions, but the level of agreement with $G_2^{\\pi^0 p}(Q^2)$ is poor.

  20. Surface mobility near threshold and other parameters of insulated gate field effect transistors

    E-Print Network [OSTI]

    Gnadinger, Alfred P.

    1970-01-01T23:59:59.000Z

    SURFACE MOBILITY NEAR THRESHOLD AND OTHER PARAMETERS OF INSULATED GATE FIELD EFFECT TRANSISTORS BY Alfred P. Gnadinger Dipl. El. Ing. ETH Swiss Federal Institute of Technology, Zurich, 1965 M.S.E.E, University of Kansas, Lawrence, 1968... Committee: May, 1970 RD0107 4S0S0 TO MY WIFE AND OUR PARENTS i ABSTRACT The mobility of the mobile carriers in the inversion layer of an Insulated Gate Field Effect Transistor (IGFET) has been investigated with particular...

  1. Elastic proton scattering on tritium below the n-$^{3}{He}$ threshold

    E-Print Network [OSTI]

    Rimantas Lazauskas

    2009-03-27T23:59:59.000Z

    Elastic proton scattering on ${}^{3}{H}$ nucleus is studied inbetween p-% ${}^{3}{H}$ and n-${}^{3}{He}$ thresholds, in the energy region where $\\alpha$-particles first excited state is inbeded in the continuum. For this aim Faddeev-Yakubovski equations are solved in configuration space, fully considering effects due to the isospin breaking as well as rigorously treating Coulomb interaction. Different realistic nuclear Hamiltonians are tested, elucidating open problems in nuclear interaction description.

  2. Electron-Positron Pair Production by an Electron in a Magnetic Field Near the Process Threshold

    E-Print Network [OSTI]

    O. P. Novak; R. I. Kholodov; P. I. Fomin

    2011-01-13T23:59:59.000Z

    The electron-positron pair production by an electron in a strong magnetic field near the process threshold is considered. The process is shown to be more probable if the spin of the initial electron is oriented along the field. In this case, the probability of the process is $\\sim10^{13} s^{-1}$ when the magnetic field strength is $H=4\\cdot 10^{12}$ G.

  3. Intensity-dependent enhancements in high-order above-threshold ionization

    SciTech Connect (OSTI)

    Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany); Hasovic, E.; Gazibegovic-Busuladzic, A. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegowina); Busuladzic, M. [Medical Faculty, University of Sarajevo, Cekalusa 90, 71000 Sarajevo (Bosnia and Herzegowina); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2007-11-15T23:59:59.000Z

    The very pronounced intensity-dependent enhancements of groups of peaks of high-order above-threshold-ionization spectra of rare-gas atoms are investigated using an improved version of the strong-field approximation, which realistically models the respective atom. Two types of enhancements are found and explained in terms of constructive interference of the contributions of a large number of long quantum orbits. The first type is observed for intensities slightly below channel closings. Its intensity dependence is comparatively smooth and it is generated by comparatively few (of the order of 20) orbits. The second type occurs precisely at channel closings and exhibits an extremely sharp intensity dependence. It requires constructive interference of a very large number of long orbits (several hundreds) and generates cusps in the electron spectrum at integer multiples of the laser-photon energy. An interpretation of these enhancements as a threshold phenomenon is also given. An interplay of different types of the threshold anomalies is observed. The position of both types of enhancements, in the photoelectron-energy--laser-intensity plane, shifts to the next channel closing intensity with the change of the ground-state parity. The enhancements gradually disappear with decreasing laser pulse duration. This confirms the interpretation of enhancements as a consequence of the interference of long strong-laser-field-induced quantum orbits.

  4. Interplay of threshold resummation and hadron mass corrections in deep inelastic processes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Accardi, Alberto; Anderle, Daniele P.; Ringer, Felix

    2015-02-01T23:59:59.000Z

    We discuss hadron mass corrections and threshold resummation for deep-inelastic scattering lN-->l'X and semi-inclusive annihilation e+e- -->hX processes, and provide a prescription how to consistently combine these two corrections respecting all kinematic thresholds. We find an interesting interplay between threshold resummation and target mass corrections for deep-inelastic scattering at large values of Bjorken xB. In semi-inclusive annihilation, on the contrary, the two considered corrections are relevant in different kinematic regions and do not affect each other. A detailed analysis is nonetheless of interest in the light of recent high precision data from BaBar and Belle on pion and kaon production,more »with which we compare our calculations. For both deep inelastic scattering and single inclusive annihilation, the size of the combined corrections compared to the precision of world data is shown to be large. Therefore, we conclude that these theoretical corrections are relevant for global QCD fits in order to extract precise parton distributions at large Bjorken xB, and fragmentation functions over the whole kinematic range.« less

  5. Interplay of threshold resummation and hadron mass corrections in deep inelastic processes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Accardi, Alberto; Anderle, Daniele P.; Ringer, Felix

    2015-02-01T23:59:59.000Z

    We discuss hadron mass corrections and threshold resummation for deep-inelastic scattering lN-->l'X and semi-inclusive annihilation e+e- -->hX processes, and provide a prescription how to consistently combine these two corrections respecting all kinematic thresholds. We find an interesting interplay between threshold resummation and target mass corrections for deep-inelastic scattering at large values of Bjorken xB. In semi-inclusive annihilation, on the contrary, the two considered corrections are relevant in different kinematic regions and do not affect each other. A detailed analysis is nonetheless of interest in the light of recent high precision data from BaBar and Belle on pion and kaon production, with which we compare our calculations. For both deep inelastic scattering and single inclusive annihilation, the size of the combined corrections compared to the precision of world data is shown to be large. Therefore, we conclude that these theoretical corrections are relevant for global QCD fits in order to extract precise parton distributions at large Bjorken xB, and fragmentation functions over the whole kinematic range.

  6. Renormalization Group Evolution of Neutrino Parameters in Presence of Seesaw Threshold Effects and Majorana Phases

    E-Print Network [OSTI]

    Shivani Gupta; Sin Kyu Kang; C. S. Kim

    2015-02-01T23:59:59.000Z

    We examine the renormalization group evolution (RGE) for different mixing scenarios in the presence of seesaw threshold effects from high energy scale (GUT) to the low electroweak (EW) scale in the Standard Model (SM) and Minimal Supersymmetric Standard Model (MSSM). We consider four mixing scenarios namely Tri-Bimaximal Mixing, Bimaximal Mixing, Hexagonal Mixing and Golden Ratio Mixing which come from different flavor symmetries at the GUT scale. We find that the Majorana phases play an important role in the RGE running of these mixing patterns along with the seesaw threshold corrections. We present a comparative study of the RGE of all these mixing scenarios both with and without Majorana CP phases when seesaw threshold corrections are taken into consideration. We find that in the absence of these Majorana phases both the RGE running and seesaw effects may lead to $\\theta_{13}energies both in the SM and MSSM. However, if the Majorana phases are incorporated to the mixing matrix the running can be enhanced both in the SM and MSSM. Even by incorporating non zero Majorana CP phases in the SM, we do not get $\\theta_{13}$ in its present 3$\\sigma$ range. The current values of the two mass squared differences and mixing angles including $\\theta_{13}$ can be produced in the MSSM case with tan$\\beta$ = 10 and non zero Majorana CP phases at low energy. We also calculate the order of effective Majorana mass and Jarlskog Invariant for each scenario under consideration.

  7. Imaging properties of the Medipix2 system exploiting single and dual energy thresholds

    E-Print Network [OSTI]

    Tlustos, Lukas; Campbell, Michael; Heijne, Erik H M; Kincade, Karla Lorraine; Llopart-Cudie, Xavier; Stejskal, Pavel

    2006-01-01T23:59:59.000Z

    Low noise, high resolution and high dose efficiency are the common requirements for most X-ray imaging applications. Especially in medical applications the dose efficiency is a necessity for detector systems. We present the imaging performance of the Medipix2 readout chip bump bonded to a 300 mu m thick Si detector as a function of the detection threshold, a free parameter not available in conventional integrating imaging systems. Spatial resolution has been measured using the modulation transfer function (MTF) and it varies between 8.2 Ip/mm and 11.0 Ip/mm at 70%. An associated measurement of noise power spectrum (NPS) permits us to derive the detective quantum efficiency (DQE) which can be as a high as 25.5 % for a broadband incoming spectrum. The influence of charge diffusion in the sensor together with threshold variation in the readout chip is discussed. Although the Medipix2 system is used in photon counting mode with a single threshold in energy, the system is also capable of counting within a given en...

  8. Physics of the Shannon Limits

    E-Print Network [OSTI]

    Merhav, Neri

    2009-01-01T23:59:59.000Z

    We provide a simple physical interpretation, in the context of the second law of thermodynamics, to the information inequality (a.k.a. the Gibbs' inequality, which is also equivalent to the log-sum inequality), asserting that the relative entropy between two probability distributions cannot be negative. Since this inequality stands at the basis of the data processing theorem (DPT), and the DPT in turn is at the heart of most, if not all, proofs of converse theorems in Shannon theory, it is observed that conceptually, the roots of fundamental limits of Information Theory can actually be attributed to the laws of physics, in particular, to the second law of thermodynamics, and at least indirectly, also to the law of energy conservation. By the same token, in the other direction: one can view the second law as stemming from information-theoretic principles.

  9. Limited-life cartridge primers

    DOE Patents [OSTI]

    Makowiecki, Daniel M.; Rosen, Robert S.

    2005-04-19T23:59:59.000Z

    A cartridge primer which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML's would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers.

  10. Limited-life cartridge primers

    DOE Patents [OSTI]

    Makowiecki, D.M.; Rosen, R.S.

    1998-06-30T23:59:59.000Z

    A cartridge primer is described which utilizes an explosive that can be designed to become inactive in a predetermined period of time: a limited-life primer. The explosive or combustible material of the primer is an inorganic reactive multilayer (RML). The reaction products of the RML are sub-micron grains of non-corrosive inorganic compounds that would have no harmful effects on firearms or cartridge cases. Unlike use of primers containing lead components, primers utilizing RML`s would not present a hazard to the environment. The sensitivity of an RML is determined by the physical structure and the stored interfacial energy. The sensitivity lowers with time due to a decrease in interfacial energy resulting from interdiffusion of the elemental layers. Time-dependent interdiffusion is predictable, thereby enabling the functional lifetime of an RML primer to be predetermined by the initial thickness and materials selection of the reacting layers. 10 figs.

  11. Limits to the lunar atmosphere

    SciTech Connect (OSTI)

    Morgan, T.H. (National Aeronautics and Space Administration, Washington, D.C. (USA)); Shemansky, D.E. (Univ. of Arizona, Tucson (USA))

    1991-02-01T23:59:59.000Z

    The presence of sodium and potassium on the Moon implies that other more abundant species should be present. Volatile molecules like H{sub 2}O are significantly more abundant than sodium in any of the proposed external atmospheric sources. Source mechanisms which derive atoms from the surface should favor abundant elements in the regolith. It is therefore puzzling that the Apollo ultraviolet spectrometer experiment set limits on the density of oxygen of N{sub O} < 5 {times} 10{sup 2} cm{sup {minus}3}, and that the Apollo Lunar Atmospheric Composition Experiment data imply N{sub O} < 50 cm{sup {minus}3} above the subsolar point. These limits are surprisingly small relative to the measured value for sodium. A simple consideration of sources and sinks predicts significantly greater densities of oxygen. It is possible but doubtful that the Apollo measurements occur ed during an epoch in which source rates were small. A preferential loss process for oxygen on the darkside of the Moon is considered in which ionization by electron capture in surface collisions leads to escape through acceleration in the local electric field. Cold trapping in permanently shadowed regions as a net sink is considered and discounted, but the episodic nature of cometary insertion may allow formation of ice layers which act as a stablized source of OH. On the basis of an assumed meteoroid impact source, the authors predict a possible emission brightness of {approximately} 50 R in the OH(A {minus} X)(0,0) band above the lunar bright limb. A very uncertain small comet source of H{sub 2}O could raise this value by more than two orders of magnitude.

  12. A limit on the ultra-high-energy neutrino flux from lunar observations with the Parkes radio telescope

    E-Print Network [OSTI]

    Bray, J D; Roberts, P; Reynolds, J E; James, C W; Phillips, C J; Protheroe, R J; McFadden, R A; Aartsen, M G

    2015-01-01T23:59:59.000Z

    We report a limit on the ultra-high-energy neutrino flux based on a non-detection of radio pulses from neutrino-initiated particle cascades in the Moon, in observations with the Parkes radio telescope undertaken as part of the LUNASKA project. Due to the improved sensitivity of these observations, which had an effective duration of 127 hours and a frequency range of 1.2-1.5 GHz, this limit extends to lower neutrino energies than those from previous lunar radio experiments, with a detection threshold below 10^20 eV. The calculation of our limit allows for the possibility of lunar-origin pulses being misidentified as local radio interference, and includes the effect of small-scale lunar surface roughness. The targeting strategy of the observations also allows us to place a directional limit on the neutrino flux from the nearby radio galaxy Centaurus A.

  13. Zero Kinetic Energy Photofragment Spectroscopy: The Threshold Dissociation of NO2 J. A. Mueller, S. A. Rogers, and Paul L. Houston*

    E-Print Network [OSTI]

    Houston, Paul L.

    at the dissociation threshold of, while for higher energies, a new peak occurs as the energy threshold is reachedZero Kinetic Energy Photofragment Spectroscopy: The Threshold Dissociation of NO2 J. A. Mueller, S. A. Rogers, and Paul L. Houston* Department of Chemistry, Cornell UniVersity, Ithaca, New York 14853

  14. Binding and structure of tetramers in the scaling limit

    E-Print Network [OSTI]

    Hadizadeh, M R; Tomio, L; Delfino, A; Frederico, T

    2011-01-01T23:59:59.000Z

    The momentum-space structure of the Faddeev-Yakubovsky (FY) components of weakly-bound tetramers is investigated at the unitary limit using a renormalized zero-range two-body interaction. The results, obtained by considering a given trimer level with binding energy $B_3$, provide further support to a universal scaling function relating the binding energies of two successive tetramer states. The correlated scaling between the tetramer energies comes from the sensitivity of the four-boson system to a short-range four-body scale. Each excited $N-$th tetramer energy $B_4^{(N)}$ moves as the short-range four-body scale changes, while the trimer properties are kept fixed, with the next excited tetramer $B_4^{(N+1)}$ emerging from the atom-trimer threshold for a universal ratio $B_4^{(N)}/B_3 = B_4^ {(N)}/B_4^{(N+1)} \\simeq 4.6$, which does not depend on $N$. We show that both channels of the FY decomposition [atom-trimer ($K-$type) and dimer-dimer ($H-$type)] present high momentum tails, which reflect the short-ran...

  15. Binding and structure of tetramers in the scaling limit

    E-Print Network [OSTI]

    M. R. Hadizadeh; M. T. Yamashita; L. Tomio; A. Delfino; T. Frederico

    2012-01-17T23:59:59.000Z

    The momentum-space structure of the Faddeev-Yakubovsky (FY)components of weakly-bound tetramers is investigated at the unitary limit using a renormalized zero-range two-body interaction. The results, obtained by considering a given trimer level with binding energy $B_3$, provide further support to a universal scaling function relating the binding energies of two successive tetramer states. The correlated scaling between the tetramer energies comes from the sensitivity of the four-boson system to a short-range four-body scale. Each excited $N-$th tetramer energy $B_4^{(N)}$ moves as the short-range four-body scale changes, while the trimer properties are kept fixed, with the next excited tetramer $B_4^{(N+1)}$ emerging from the atom-trimer threshold for a universal ratio $B_4^{(N)}/B_3 = B_4^ {(N)}/B_4^{(N+1)} \\simeq 4.6$, which does not depend on $N$. We show that both channels of the FY decomposition [atom-trimer ($K-$type) and dimer-dimer ($H-$type)] present high momentum tails, which reflect the short-range four-body scale. We also found that the $H-$channel is favored over $K-$channel at low momentum when the four-body momentum scale largely overcomes the three-body one.

  16. Above-threshold multiphoton detachment from the H- ion by 10.6-?m radiation: Angular distributions and partial widths

    E-Print Network [OSTI]

    Chu, Shih-I; Telnov, Dmitry A.

    1994-11-01T23:59:59.000Z

    We present a general procedure for accurate nonperturbative treatment of the angular distribution and partial widths for multiphoton above-threshold detachment (ATD) of atoms or negative ions in intense laser fields. The procedure consists...

  17. Anomaly in the K^0_S Sigma^+ photoproduction cross section off the proton at the K* threshold

    E-Print Network [OSTI]

    R. Ewald; A. V. Anisovich; B. Bantes; O. Bartholomy; D. Bayadilov; R. Beck; Y. A. Beloglazov; K. -T. Brinkmann; V. Crede; H. Dutz; D. Elsner; K. Fornet-Ponse; F. Frommberger; Ch. Funke; A. B. Gridnev; E. Gutz; W. Hillert; J. Hannappel; P. Hoffmeister; I. Jaegle; O. Jahn; T. Jude; J. Junkersfeld; H. Kalinowsky; S. Kammer; V. Kleber; Frank Klein; Friedrich Klein; E. Klempt; B. Krusche; M. Lang; H. Löhner; I. V. Lopatin; D. Menze; T. Mertens; J. G. Messchendorp; V. Metag; M. Nanova; V. A. Nikonov; D. Novinski; R. Novotny; M. Ostrick; L. Pant; H. van Pee; A. Roy; A. V. Sarantsev; S. Schadmand; Ch. Schmidt; H. Schmieden; B. Schoch; S. Shende; V. Sokhoyan; A. Süle; V. V. Sumachev; T. Szczepanek; U. Thoma; D. Trnka; R. Varma; D. Walther; Ch. Wendel

    2011-12-04T23:59:59.000Z

    The $\\gamma + p \\rightarrow K^0 + \\Sigma^+$ photoproduction reaction is investigated in the energy region from threshold to $E_\\gamma = 2250$\\,MeV. The differential cross section exhibits increasing forward-peaking with energy, but only up to the $K^*$ threshold. Beyond, it suddenly returns to a flat distribution with the forward cross section dropping by a factor of four. In the total cross section a pronounced structure is observed between the $K^*\\Lambda$ and $K^*\\Sigma$ thresholds. It is speculated whether this signals the turnover of the reaction mechanism from t-channel exchange below the $K^*$ production threshold to an s-channel mechanism associated with the formation of a dynamically generated $K^*$-hyperon intermediate state.

  18. Evidence of a Threshold Wind Speed in Tower-mounted Scatterometer Data David W. Draper and David G. Long

    E-Print Network [OSTI]

    Long, David G.

    . Evidence of the threshold wind speed and a hysteresis effect have been observed in airship and wave tank in airship data [2]. YSCAT, an ultra-wideband (2-14 GHz) tower-mounted scat- terometer, provides significant

  19. Wave-packet propagation based calculation of above-threshold ionization in the x-ray regime

    E-Print Network [OSTI]

    Tilley, Matthew; Santra, Robin

    2015-01-01T23:59:59.000Z

    We investigate the multi-photon process of above-threshold ionization for the light elements hydrogen, carbon, nitrogen and oxygen in the hard x-ray regime. Numerical challenges are discussed and by comparing Hartree-Fock-Slater calculations to configuration-interaction-singles results we justify the mean-field potential approach in this regime. We present a theoretical prediction of two-photon above-threshold-ionization cross sections for the mentioned elements. Moreover, we study how the importance of above-threshold ionization varies with intensity. We find that for carbon, at x-ray intensities around $10^{23}{\\rm Wcm}^{-2}$, two-photon above-threshold ionization of the K-shell electrons is as probable as one-photon ionization of the L-shell electrons.

  20. Identification of the stimulated-emission threshold in high-{beta} nanoscale lasers through phase-space reconstruction

    SciTech Connect (OSTI)

    Hachair, X.; Elvira, D.; Le Gratiet, L.; Lemaitre, A.; Abram, I.; Sagnes, I.; Robert-Philip, I.; Beveratos, A. [Laboratoire de Photonique et de Nanostructures, CNRS-UPR20, Route de Nozay, 91460 Marcoussis (France); Braive, R. [Laboratoire de Photonique et de Nanostructures, CNRS-UPR20, Route de Nozay, 91460 Marcoussis (France); Universite Paris Denis Diderot, 75205 Paris, Cedex 13 (France); Lippi, G. L. [Institut Non Lineaire de Nice, Universite de Nice-Sophia Antipolis, 1361 Route des Lucioles, F-06560 Valbonne (France); Institut Non Lineaire de Nice, CNRS UMR 6618, 1361 Route des Lucioles, F-06560 Valbonne (France)

    2011-05-15T23:59:59.000Z

    Nanoscale lasers sustain a few optical modes so that the fraction of spontaneous emission {beta} funnelled into the useful (lasing) mode is high (of the order of 10{sup -1}) and the threshold, which traditionally corresponds to an abrupt kink in the light-in-light-out curve, becomes ill defined. We propose an alternative definition of the threshold that is based on the dynamical response of the laser and is valid even for {beta}=1 lasers. The laser dynamics is analyzed through a reconstruction of its phase-space trajectory for pulsed excitations. Crossing the threshold, brings about a change in the shape of the trajectory and in the area contained in it. An unambiguous determination of the threshold in terms of this change is shown theoretically and illustrated experimentally in a photonic-crystal laser.

  1. Measurement and modeling of infrared nonlinear absorption coefficients and laser-induced damage thresholds in Ge and GaSb

    SciTech Connect (OSTI)

    Wagner, T. J.; Bohn, M. J.; Coutu, R. A. Jr. [Air Force Institute of Technology, Wright Patterson Air Force Base, Ohio 45433 (United States); Gonzalez, L. P.; Murray, J. M.; Guha, S. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States); Schepler, K. L. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States)

    2010-10-15T23:59:59.000Z

    Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, we measure two-photon and free-carrier absorption coefficients for Ge and GaSb at 2.05 and 2.5 {mu}m for the first time, to our knowledge. Results agreed well with published theory. Single-shot damage thresholds were also measured at 2.5 {mu}m and agreed well with modeled thresholds using experimentally determined parameters including nonlinear absorption coefficients and temperature dependent linear absorption. The damage threshold for a single-layer Al{sub 2}O{sub 3} anti-reflective coating on Ge was 55% or 35% lower than the uncoated threshold for picosecond or nanosecond pulses, respectively.

  2. Photon and graviton mass limits

    SciTech Connect (OSTI)

    Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

    2008-01-01T23:59:59.000Z

    We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

  3. Kinetic limits of dynamical systems

    E-Print Network [OSTI]

    Jens Marklof

    2014-08-06T23:59:59.000Z

    Since the pioneering work of Maxwell and Boltzmann in the 1860s and 1870s, a major challenge in mathematical physics has been the derivation of macroscopic evolution equations from the fundamental microscopic laws of classical or quantum mechanics. Macroscopic transport equations lie at the heart of many important physical theories, including fluid dynamics, condensed matter theory and nuclear physics. The rigorous derivation of macroscopic transport equations is thus not only a conceptual exercise that establishes their consistency with the fundamental laws of physics: the possibility of finding deviations and corrections to classical evolution equations makes this subject both intellectually exciting and relevant in practical applications. The plan of these lectures is to develop a renormalisation technique that will allow us to derive transport equations for the kinetic limits of two classes of simple dynamical systems, the Lorentz gas and kicked Hamiltonians (or linked twist maps). The technique uses the ergodic theory of flows on homogeneous spaces (homogeneous flows for short), and is based on joint work with Andreas Str\\"ombergsson.

  4. Multiple pulse thermal damage thresholds of materials for x-ray free electron laser optics investigated with an ultraviolet laser

    SciTech Connect (OSTI)

    Hau-Riege, Stefan P.; London, Richard A.; Bionta, Richard M.; Soufli, Regina; Ryutov, Dmitri; Shirk, Michael; Baker, Sherry L. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94539 (United States); Smith, Patrick M.; Nataraj, Pradeep [Kovio, Inc., 1145 Sonora Court, Sunnyvale, California 94086 (United States)

    2008-11-17T23:59:59.000Z

    Optical elements to be used for x-ray free electron lasers (XFELs) must withstand multiple high-fluence pulses. We have used an ultraviolet laser to study the damage of two candidate materials, crystalline Si and B{sub 4}C-coated Si, emulating the temperature profile expected to occur in optics exposed to XFEL pulses. We found that the damage threshold for 10{sup 5} pulses is {approx}20% to 70% lower than the melting threshold.

  5. The Fermi-Pasta-Ulam problem revisited: stochasticity thresholds in nonlinear Hamiltonian systems

    E-Print Network [OSTI]

    Lapo Casetti; Monica Cerruti-Sola; Marco Pettini; E. G. D. Cohen

    1998-04-21T23:59:59.000Z

    The Fermi-Pasta-Ulam $\\alpha$-model of harmonic oscillators with cubic anharmonic interactions is studied from a statistical mechanical point of view. Systems of N= 32 to 128 oscillators appear to be large enough to suggest statistical mechanical behavior. A key element has been a comparison of the maximum Lyapounov coefficient $\\lambda_{max}$ of the FPU $\\alpha$-model and that of the Toda lattice. For generic initial conditions, $\\lambda_{max}(t)$ is indistinguishable for the two models up to times that increase with decreasing energy (at fixed N). Then suddenly a bifurcation appears, which can be discussed in relation to the breakup of regular, soliton-like structures. After this bifurcation, the $\\lambda_{max}$ of the FPU model appears to approach a constant, while the $\\lambda_{max}$ of the Toda lattice appears to approach zero, consistent with its integrability. This suggests that for generic initial conditions the FPU $\\alpha$-model is chaotic and will therefore approach equilibrium and equipartition of energy. There is, however, a threshold energy density $\\epsilon_c(N)\\sim 1/N^2$, below which trapping occurs; here the dynamics appears to be regular, soliton-like and the approach to equilibrium - if any - takes longer than observable on any available computer. Above this threshold the system appears to behave in accordance with statistical mechanics, exhibiting an approach to equilibrium in physically reasonable times. The initial conditions chosen by Fermi, Pasta and Ulam were not generic and below threshold and would have required possibly an infinite time to reach equilibrium.

  6. Infrared limit in external field scattering

    E-Print Network [OSTI]

    Andrzej Herdegen

    2012-05-17T23:59:59.000Z

    Scattering of electrons/positrons by external classical electromagnetic wave packet is considered in infrared limit. In this limit the scattering operator exists and produces physical effects, although the scattering cross-section is trivial.

  7. Fractal Graphics Proprietary Limited 39 Fairway, Nedlands,

    E-Print Network [OSTI]

    Boschetti, Fabio

    1 Fractal Graphics Proprietary Limited 39 Fairway, Nedlands, Western Australia, Australia 6009 djh@fractalgraphics.com.au 2 Fractal Graphics Proprietary Limited 39 Fairway, Nedlands, Western Australia, Australia 6009 nja

  8. FUNDAMENTAL PERFORMANCE LIMITS OF WIRELESS SENSOR NETWORKS

    E-Print Network [OSTI]

    Li, Baochun

    FUNDAMENTAL PERFORMANCE LIMITS OF WIRELESS SENSOR NETWORKS ZHIHUA HU, BAOCHUN LI Abstract. Understanding the fundamental performance limits of wireless sensor networks is critical towards. Key words. Wireless sensor networks, network capacity, network lifetime. 1. Introduction. When

  9. Neural substrates of cognitive capacity limitations

    E-Print Network [OSTI]

    Buschman, Tim

    Cognition has a severely limited capacity: Adult humans can retain only about four items “in mind”. This limitation is fundamental to human brain function: Individual capacity is highly correlated with intelligence measures ...

  10. Implementing Risk-Limiting Audits in California

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    cast09.pdf. Philip B. Stark. Risk-limiting post-electionthe N.J. law the ?rst “risk-based statistical audit law. ”Holt bill does not limit risk. The Holt bill has a clause

  11. Dynamics of $K^+$ Production in Heavy Ion Collisions close to Threshold

    E-Print Network [OSTI]

    Christoph Hartnack

    2005-07-01T23:59:59.000Z

    In this article the production of $K^+$ at energies close to the threshold is studied in detail. The production mechanisms, the influence of in-medium effects, cross sections, the nuclear equation of state and the dynamics of the nucleons on the kaon dynamics are discussed. A special regard will be taken on the collision of Au+Au at 1.5 GeV, a reaction that has recently been analyzed in detail by experiments performed by the KaoS and FOPI collaborations at the SIS accelerator at GSI.

  12. Kinetic Model for a Threshold Filter in an Enzymatic System for Bioanalytical and Biocomputing Applications

    E-Print Network [OSTI]

    Vladimir Privman; Sergii Domanskyi; Shay Mailloux; Yaovi Holade; Evgeny Katz

    2014-11-09T23:59:59.000Z

    A recently experimentally observed biochemical "threshold filtering" mechanism by processes catalyzed by the enzyme malate dehydrogenase is explained in terms of a model that incorporates an unusual mechanism of inhibition of this enzyme that has a reversible mechanism of action. Experimental data for a system in which the output signal is produced by biocatalytic processes of the enzyme glucose dehydrogenase are analyzed to verify the model's validity. We also establish that fast reversible conversion of the output product to another compound, without the additional inhibition, cannot on its own result in filtering.

  13. Systematics of threshold incident energy for deep sub-barrier fusion hindrance

    E-Print Network [OSTI]

    Takatoshi Ichikawa; Kouichi Hagino; Akira Iwamoto

    2007-04-21T23:59:59.000Z

    We systematically evaluate the potential energy at the touching configuration for heavy-ion reactions using various potential models. We point out that the energy at the touching point, especially that estimated with the Krappe-Nix-Sierk (KNS) potential, strongly correlates with the threshold incident energy for steep fall-off of fusion cross sections observed recently for several systems at extremely low energies. This clearly indicates that the steep fall-off phenomenon can be attributed to the dynamics after the target and projectile touch with each other, e.g., the tunneling process and the nuclear saturation property in the overlap region.

  14. Single-growth embedded epitaxy AlGaAs injection lasers with extremely low threshold currents

    SciTech Connect (OSTI)

    Katz, J.; Margalit, S.; Wilt, D.; Chen, P.C.; Yariv, A.

    1980-12-01T23:59:59.000Z

    A new type of strip-geometry AlGaAs double-heterostructure laser with an embedded optical waveguide has been developed. The new structure is fabricated using a single step of epitaxial growth. Lasers with threshold currents as low as 9.5 mA (150 ..mu..m long) were obtained. These lasers exhibit operation in a single spatial and longitudinal mode, have differential quantum efficiencies exceeding 45%, and a characteristic temperature of 175/sup 0/ C. They emit more than 12 mW/facet of optical power without any kinks.

  15. Final state interactions at the threshold of Higgs boson pair production

    E-Print Network [OSTI]

    Zhang, Zhentao

    2015-01-01T23:59:59.000Z

    We study the effect of final state interactions at the threshold of Higgs boson pair production in the Glashow-Weinberg-Salam model. We consider three major processes of the pair production in the model: lepton pair annihilation, ZZ fusion, and WW fusion. We find that the corrections caused by the effect for these processes are markedly different. According to our results, the effect can cause non-negligible corrections to the cross sections for lepton pair annihilation and small corrections for ZZ fusion, and this effect is negligible for WW fusion.

  16. Threshold conditions for lasing of a free electron laser oscillator with longitudinal electrostatic wiggler

    SciTech Connect (OSTI)

    Sepehri Javan, N. [Department of Physics, Faculty of Sciences, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil, 56199-11367 (Iran, Islamic Republic of)

    2012-12-15T23:59:59.000Z

    The system of the nonlinear non-stationary equations describing spatial-temporal dynamics of the amplitudes of an ondulator radiation and a space-charge wave of a relativistic electron beam in the resonator is obtained. A free electron laser resonator with longitudinal electrostatic wiggler is considered. In the linear approximation, the threshold conditions of lasing for Raman and Compton regimes under excitation of forward and backward electromagnetic wave are achieved. In the various physical situations, the variation of the minimum length of the resonator with the amplitude of wiggler, density of electron beam, and with the reflection coefficients of resonator's mirrors is investigated.

  17. 190-fs passively mode-locked thulium fiber laser with a low threshold

    SciTech Connect (OSTI)

    Sharp, R.C.; Spock, D.E.; Pan, N.; Elliot, J. [Raytheon Company, Electronic Systems, 131 Spring Street, Lexington, Massachusetts 02173 (United States)

    1996-06-01T23:59:59.000Z

    We report a self-starting passively mode-locked thulium-doped silica fiber laser capable of 190-fs pulses. This practical, compact package is driven by a single 50-mW passively cooled diode laser, has a launched pump-power threshold of 18 mW for mode locking, and produces a 50-MHz train of mode-locked 20-pJ pulses at a wavelength near 1.9 {mu}m. {copyright} {ital 1996 Optical Society of America.}

  18. Energy scan by $?$ mesons and threshold energy for the confinement-deconfinement phase transition

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2010-05-18T23:59:59.000Z

    We argue that the ratio of $\\phi$ mesons multiplicity over cube of the mean $p_T$ is proportional to the degeneracy of the medium produced in ultra-relativistic heavy ion collisions. The ratio extracted from the existing $\\phi$ meson data in the energy range $\\sqrt{s}$=6.3-200 GeV, indicate that beyond a threshold energy $\\sqrt{s}_{th}=15.74\\pm 8.10$ GeV, the medium crosses over from a confined phase to a deconfined phase.

  19. Crack closure effects on fatigue crack growth thresholds and remaining life in an HSLA steel

    SciTech Connect (OSTI)

    Todd, J.A.; Mostovoy, S. [Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Mechanical, Materials and Aerospace Engineering; Chen, L. [Texas Instruments, Attleboro, MA (United States); Yankov, E.Y. [A. Finkl and Sons, Chicago, IL (United States)

    1997-02-01T23:59:59.000Z

    The effects of crack closure on the near-threshold corrosion fatigue crack growth behavior of Mil S-24645 HSLA steel and its weld metal have been investigated in air, ASTM seawater at the free corrosion potential, and ASTM seawater at {minus}0.8V and {minus}1.0V (SCE) using frequencies of 10, 2, and 0.2 Hz, and a stress ratio, R = 0.1. Remaining life, in the presence and absence of crack closure, has been estimated as a function of applied stress range for a structure containing a 3-mm-deep surface semi-elliptical flaw.

  20. Multiscale analysis of the laser-induced damage threshold in optical coatings

    SciTech Connect (OSTI)

    Capoulade, Jeremie; Gallais, Laurent; Natoli, Jean-Yves; Commandre, Mireille

    2008-10-10T23:59:59.000Z

    We have investigated the influence of laser beam size on laser-induced damage threshold (LIDT) in the case of single- and multiple-shot irradiation. The study was performed on hafnia thin films deposited with various technologies (evaporation, sputtering, with or without ion assistance). LIDT measurements were carried out at 1064 nm and 12 ns with a spot size ranging from a few tens to a few hundreds of micrometers, in 1-on-1 and R-on-1 modes. These measurements were compared with simulations obtained with the statistical theory of laser-induced damage caused by initiating inclusions.

  1. Modeling of recurrent threshold crossings due to noise with long memory

    E-Print Network [OSTI]

    Singh, Abhishek Narayan

    2007-04-25T23:59:59.000Z

    of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee: Laszlo B. Kish Committee Members: Don R. Halverson C.B. William H. Marlow....S., The University of Texas at Arlington Chair of Advisory Committee: Dr. Laszlo B. Kish This thesis addresses the recurrent threshold crossing behavior of long-time correlated noise. The behavior of long-time correlated noise like f , 5.1 , and 2 can...

  2. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, J.R.

    1997-02-04T23:59:59.000Z

    A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

  3. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, John R. (Hinsdale, IL)

    1997-01-01T23:59:59.000Z

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  4. Production of K?K? pairs in proton-proton collisions below the ? meson threshold

    SciTech Connect (OSTI)

    Ye, Q. J.; Hartmann, M.; Chiladze, D.; Dymov, S.; Dzyuba, A.; Gao, H.; Gebel, R.; Hejny, V.; Kacharava, A.; Lorentz, B.; Mchedlishvili, D.; Merzliakov, S.; Mielke, M.; Mikirtytchiants, S.; Ohm, H.; Papenbrock, M.; Polyanskiy, A.; Serdyuk, V.; Stein, H. J.; Ströher, H.; Trusov, S.; Valdau, Yu.; Wilkin, C.; Wüstner, P.

    2013-06-01T23:59:59.000Z

    The pp?ppK?K? reaction was measured below the ? threshold at a beam energy of 2.568 GeV using the COSY-ANKE magnetic spectrometer. By assuming that the four-body phase space is distorted only by the product of two-body final-state interactions, fits to a variety of one-dimensional distributions permit the evaluation of differential and total cross sections. The shapes of the distributions in the Kp and Kpp invariant masses are reproduced only if the K?p interaction is even stronger than that found at higher energy. The cusp effect in the K?K? distribution at the K?K¯¯¯? threshold is much more clear and some evidence is also found for coupling between the K?p and K¯¯¯?n channels. However, the energy dependence of the total cross section cannot be reproduced by considering only a simple product of such pairwise final-state interactions.

  5. Mass-Analyzed Threshold Ionization (MATI) Spectroscopy of Atoms and Molecules using VUV Synchrotron Radiation

    SciTech Connect (OSTI)

    Kostko, Oleg; Kim, Sang Kyu; Leone, Stephen R.; Ahmed, Musahid

    2009-01-28T23:59:59.000Z

    Mass-analyzed threshold ionization (MATI) spectroscopy using synchrotron radiation (Advanced Light Source, Lawrence Berkeley National Laboratory) has been performed for Ar, N2, O2, N2O, H2O, C2H2, and C6H6. MATI allows for a better determination of ionization energies compared to those derived from photoionization efficiency curves traditionally used in synchrotron photoionization mass spectrometry. The separation of the long-lived Rydberg state from the directly-formed prompt ion, essential for a meaningful MATI spectrum, has been accomplished by employing an arrangement of ion optics coupled to unique electric-field pulsing schemes. For Ar, a number of resolved bands below the ionization energy are observed, and these are ascribed to high-n,l Rydberg states prepared in the MATI scheme. The first vibrational stateresolved MATI spectra of N2 and O2 are reported and spectral characteristics are discussed in comparison with previously-reported threshold photoelectron spectroscopic studies. While MATI performed with synchrotron radiation is intrinsically less sensitive compared to laser based sources, this work demonstrates that MATI spectroscopy performed with widely tunable VUV radiation is a complementary technique for studying the ionization spectroscopy of polyatomic molecules.

  6. A precision measurement of the $p$($e,e^\\prime p\\,$)$?^0$ reaction at threshold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chirapatpimol, Khem [UVA; et. al.,

    2015-05-01T23:59:59.000Z

    New results are reported from a measurement of $\\pi^0$ electroproduction near threshold using the $p(e,e^{\\prime} p)\\pi^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $\\phi^*_{\\pi}$ and $\\theta^*_{\\pi}$ angles in the $p \\pi^0$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. The 4-momentum transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement.

  7. Qualitative and analytical results of the bifurcation thresholds to halo orbits

    E-Print Network [OSTI]

    Sara Bucciarelli; Marta Ceccaroni; Alessandra Celletti; Giuseppe Pucacco

    2015-02-01T23:59:59.000Z

    We study the dynamics in the neighborhood of the collinear Lagrangian points in the spatial, circular, restricted three--body problem. We consider the case in which one of the primaries is a radiating body and the other is oblate (although the latter is a minor effect). Beside having an intrinsic mathematical interest, this model is particularly suited for the description of a mission of a spacecraft (e.g., a solar sail) to an asteroid. The aim of our study is to investigate the occurrence of bifurcations to halo orbits, which take place as the energy level is varied. The estimate of the bifurcation thresholds is performed by analytical and numerical methods: we find a remarkable agreement between the two approaches. As a side result, we also evaluate the influence of the different parameters, most notably the solar radiation pressure coefficient, on the dynamical behavior of the model. To perform the analytical and numerical computations, we start by implementing a center manifold reduction. Next, we estimate the bifurcation values using qualitative techniques (e.g. Poincar\\'e surfaces, frequency analysis, FLIs). Concerning the analytical approach, following \\cite{CPS} we implement a resonant normal form, we transform to suitable action-angle variables and we introduce a detuning parameter measuring the displacement from the synchronous resonance. The bifurcation thresholds are then determined as series expansions in the detuning. Three concrete examples are considered and we find in all cases a very good agreement between the analytical and numerical results.

  8. Production of K+K? pairs in proton-proton collisions below the ? meson threshold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ye, Q. J.; Hartmann, M.; Chiladze, D.; Dymov, S.; Dzyuba, A.; Gao, H.; Gebel, R.; Hejny, V.; Kacharava, A.; Lorentz, B.; Mchedlishvili, D.; Merzliakov, S.; Mielke, M.; Mikirtytchiants, S.; Ohm, H.; Papenbrock, M.; Polyanskiy, A.; Serdyuk, V.; Stein, H. J.; Ströher, H.; Trusov, S.; Valdau, Yu.; Wilkin, C.; Wüstner, P.

    2013-06-01T23:59:59.000Z

    The pp?ppK+K? reaction was measured below the ? threshold at a beam energy of 2.568 GeV using the COSY-ANKE magnetic spectrometer. By assuming that the four-body phase space is distorted only by the product of two-body final-state interactions, fits to a variety of one-dimensional distributions permit the evaluation of differential and total cross sections. The shapes of the distributions in the Kp and Kpp invariant masses are reproduced only if the K?p interaction is even stronger than that found at higher energy. The cusp effect in the K+K? distribution at the K0K{bar}0 threshold is much more clear and some evidence is also found for coupling between the K?p and K?0n channels. However, the energy dependence of the total cross section cannot be reproduced by considering only a simple product of such pairwise final-state interactions.

  9. Precision Measurement of the p(e, e´p) ?? Reaction at Threshold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chirapatpimol, K.; Shabestari, M.H.; Lindgren, R. A.; Smith, L. C.; Annand, J. R. M.; Higinbotham, D. W.; Moffit, B.

    2015-05-01T23:59:59.000Z

    New results are reported from a measurement of $\\pi^0$ electroproduction near threshold using the p(e, e´p) ?? reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $\\phi^*_{\\pi}$ and $\\theta^*_{\\pi}$ angles in the $p \\pi^0$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. Themore »4-momentum transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement.« less

  10. Precision Measurement of the p ( e , e ' p ) ? 0 Reaction at Threshold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chirapatpimol, K.; Shabestari, M.H.; Lindgren, R.A.; Smith, L.C.; Annand, J.R.M.; Higinbotham, D.W.; Moffit, B.; Nelyubin, V.; Norum, B.E.; Allada, K.; Aniol, K.; Ardashev, K.; Armstrong, D.S.; Arndt, R.A.; Benmokhtar, F.; Bernstein, A.M.; Bertozzi, W.; Briscoe, W.J.; Bimbot, L.; Camsonne, A.; Chen, J.-P.; Choi, S.; Chudakov, E.; Cisbani, E.; Cusanno, F.; Dalton, M.M.; Dutta, C.; Egiyan, K.; Fernàndez-Ramìrez, C.; Feuerbach, R.; Fissum, K.G.; Frullani, S.; Garibaldi, F.; Gayou, O.; Gilman, R.; Gilad, S.; Goity, J.; Gomez, J.; Hahn, B.; Hamilton, D.; Hansen, J.-O.; Huang, J.; Igarashi, R.; Ireland, D.; de Jager, C.W.; Jin, X.; Jiang, X.; Jinasundera, T.; Kellie, J.; Keppel, C.E.; Kolb, N.; LeRose, J.; Liyanage, N.; Livingston, K.; McNulty, D.; Mercado, L.; Michaels, R.; Mihovilovi?, M.; Qian, S.; Qian, X.; Mailyan, S.; Mamyan, V.; Marrone, S.; Monaghan, P.; Nanda, S.; Perdrisat, C.F.; Piasetzky, E.; Protopopescu, D.; Punjabi, V.; Qiang, Y.; Rachek, I.A.; Rakhman, A.; Riordan, S.; Ron, G.; Rosner, G.; Saha, A.; Sawatzky, B.; Shahinyan, A.; Širca, S.; Sparveris, N.; Subedi, R.R.; Suleiman, R.; Strakovsky, I.; Sulkosky, V.; Moinelo, J.; Voskanyan, H.; Wang, K.; Wang, Y.; Watson, J.; Watts, D.; Wojtsekhowski, B.; Workman, R.L.; Yao, H.; Zhan, X.; Zhang, Y.; Hall A Collaboration

    2015-05-01T23:59:59.000Z

    New results are reported from a measurement of ?? electroproduction near threshold using the p(e,e'p)?? reaction. The experiment was designed to determine precisely the energy dependence of s- and p-wave electromagnetic multipoles as a stringent test of the predictions of chiral perturbation theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the ?*? and ?*? angles in the p?? center of mass was obtained for invariant energies above threshold from 0.5 up to 15 MeV. The 4-momentum transfer Q² coverage ranges from 0.05 to 0.155 (GeV/c)² in fine steps. A simple phenomenological analysis of our data shows strong disagreement with p-wave predictions from ChPT for Q²>0.07 (GeV/c)², while the s-wave predictions are in reasonable agreement.

  11. A precision measurement of the $p$($e,e^\\prime p\\,$)$?^0$ reaction at threshold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chirapatpimol, Khem; et. al.,

    2015-05-01T23:59:59.000Z

    New results are reported from a measurement of $\\pi^0$ electroproduction near threshold using the $p(e,e^{\\prime} p)\\pi^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $\\phi^*_{\\pi}$ and $\\theta^*_{\\pi}$ angles in the $p \\pi^0$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. The 4-momentummore »transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement.« less

  12. Production of K?K? pairs in proton-proton collisions below the ? meson threshold

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ye, Q. J.; Hartmann, M.; Chiladze, D.; Dymov, S.; Dzyuba, A.; Gao, H.; Gebel, R.; Hejny, V.; Kacharava, A.; Lorentz, B.; et al

    2013-06-01T23:59:59.000Z

    The pp?ppK?K? reaction was measured below the ? threshold at a beam energy of 2.568 GeV using the COSY-ANKE magnetic spectrometer. By assuming that the four-body phase space is distorted only by the product of two-body final-state interactions, fits to a variety of one-dimensional distributions permit the evaluation of differential and total cross sections. The shapes of the distributions in the Kp and Kpp invariant masses are reproduced only if the K?p interaction is even stronger than that found at higher energy. The cusp effect in the K?K? distribution at the K?K¯¯¯? threshold is much more clear and some evidencemore »is also found for coupling between the K?p and K¯¯¯?n channels. However, the energy dependence of the total cross section cannot be reproduced by considering only a simple product of such pairwise final-state interactions.« less

  13. The study of threshold behaviour of effective potential for $^{6}$Li+$^{58,64}$Ni systems

    E-Print Network [OSTI]

    M. Biswas; Subinit Roy; M. Sinha; M. K. Pradhan; A. Mukherjee; P. Basu; H. Majumdar; K. Ramachandran; A. Shrivastava

    2008-01-30T23:59:59.000Z

    The elastic scattering for $^6$Li+$^{64}$Ni system was measured in the bombarding energy range of 13 MeV $\\leq$ $E_{lab}$ $\\leq$ 26 MeV. A phenomenological optical model analysis was performed and the behaviour of the surface strengths of the potential components with decreasing energy was extracted. A further analysis of the measured angular distributions, along with the existing data for $^6$Li+$^{58}$Ni, was performed with two different model potentials - one with the folded potential normalized with a complex factor (OMP1) and the other with a {\\it hybrid} potential composed of a renormalized folded real and a phenomenological imaginary (OMP2) potential components - were used in the calculation. All the model potentials predict similar energy dependent behaviour for the interaction potential around the barrier. The observed energy dependence of the strengths of the real and imaginary potentials corroborate with the dispersion relation prediction for both the $^6$Li+$^{64}$Ni and $^6$Li+$^{58}$Ni systems. Though the evidence of breakup is distinct in the energy variation of the potential strengths, close to the barrier the variation is more in the line of conventional threshold anomaly. Also the threshold behaviour of the interaction potential does not indicate any distinct isotopic dependence.

  14. A precision measurement of the $p$($e,e^\\prime p\\,$)$?^0$ reaction at threshold

    E-Print Network [OSTI]

    K. Chirapatpimol; M. H. Shabestari; R. A. Lindgren; L. C. Smith; J. R. M. Annand; D. W. Higinbotham; B. Moffit; V. Nelyubin; B. E. Norum; K. Allada; K. Aniol; K. Ardashev; D. S. Armstrong; R. A. Arndt; F. Benmokhtar; A. M. Bernstein; W. Bertozzi; W. J. Briscoe; L. Bimbot; A. Camsonne; J. -P. Chen; S. Choi; E. Chudakov; E. Cisbani; F. Cusanno; M. M. Dalton; C. Dutta; K. Egiyan; C. Fernandez-Ramirez; R. Feuerbach; K. G. Fissum; S. Frullani; F. Garibaldi; O. Gayou; R. Gilman; S. Gilad; J. Goity; J. Gomez; B. Hahn; D. Hamilton; J. -O. Hansen; J. Huang; R. Igarashi; D. Ireland; C. W. de Jager; X. Jin; X. Jiang; T. Jinasundera; J. Kellie; C. E. Keppel; N. Kolb; J. LeRose; N. Liyanage; K. Livingston; D. McNulty; L. Mercado; R. Michaels; M. Mihovilovic; S. Qian; X. Qian; S. Mailyan; V. Mamyan; S. Marrone; P. Monaghan; S. Nanda; C. F. Perdrisat; E. Piasetzky; D. Protopopescu; V. Punjabi; Y. Qiang; I. A. Rachek; A. Rakhman; G. Ron; G. Rosner; A. Saha; B. Sawatzky; A. Shahinyan; S. Sirca; N. Sparveris; R. R. Subedi; R. Suleiman; I. Strakovsky; V. Sulkosky; J. Moinelo; H. Voskanyan; K. Wang; Y. Wang; J. Watson; D. Watts; B. Wojtsekhowski; R. L. Workman; H. Yao; X. Zhan; Y. Zhang

    2015-04-10T23:59:59.000Z

    New results are reported from a measurement of $\\pi^0$ electroproduction near threshold using the $p(e,e^{\\prime} p)\\pi^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $\\phi^*_{\\pi}$ and $\\theta^*_{\\pi}$ angles in the $p \\pi^0$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. The 4-momentum transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement.

  15. Impact limiter retention using a tape joint

    SciTech Connect (OSTI)

    Gonzales, A.; Eakes, R.G.

    1986-01-01T23:59:59.000Z

    The Beneficial Uses Shipping System (BUSS) Cask employs polyurethane foam impact limiters that fit onto the ends of the cask. A foam impact limiter takes energy out of a system during a hypothetical accident condition by allowing foam crush and large deformations to occur. This, in turn, precludes high stresses or deformations from occurring to the cask. Because of the need to transmit significant amounts of heat to the environment, the BUSS cask impact limiters were designed to shield a minimum amount of the cask surface area. With this design impact limiter retention after the initial impact resulting from the 9 meter regulatory drops becomes a concern. Retention is essential to ensure the cask does not experience higher stresses during any secondary or rebound effects without impact limiters than it does during the 9 meter regulatory drop with impact limiters in place.

  16. An evaluation of the respiratory hazards found in silk screen printing, Texas Department of Criminal Justice, Beto I unit

    E-Print Network [OSTI]

    Robertson, Christina Elisabeth

    1995-01-01T23:59:59.000Z

    in ppm Compared with Respirator Concentration . . . . . . , . . . . , . 21 TABLE VI. Peak Exposure Data . . 22 TABLE VII. Descriptive Statistics of the Final Sampling Survey Data . . 28 TABLE VIII. Proposed PELs for Glycol Ethers . . 34 INTRODUCTION... lists the TLVs, short-term exposure limits (STELs), and Permissible Exposure Limits (PELs) for those chemicals with assigned limits. TABLE IL Exposure Limit Data for Chemicals in Question. '~" Chemical Name TLV, ppm STEL, ppm PEL, ppm Dipropylene...

  17. Ultralow threshold graded-index separate-confinement heterostructure single quantum well (Al,Ga)As lasers

    SciTech Connect (OSTI)

    Derry, P.L.; Chen, H.Z.; Morkoc, H.; Yariv, A.; Lau, K.Y.; Bar-Chaim, N.; Lee, K.; Rosenberg, J.

    1988-03-01T23:59:59.000Z

    Broad area graded-index separate-confinement heterostructure single quantum well lasers grown by molecular-beam epitaxy (MBE) with threshold current density as low as 93 A/cm/sup 2/ (520 ..mu..m long) have been fabricated. Buried lasers formed from similarly structured MBE material with liquid phase epitaxy regrowth had threshold currents at submilliampere levels when high reflectivity coatings were applied to the end facets. A cw threshold current of 0.55 mA was obtained for a laser with facet reflectivities of approx.80%, a cavity length of 120 ..mu..m, and an active region stripe width of 1 ..mu..m. These devices driven directly with logic level signals have switch-on delays <50 ps without any current prebias. Such lasers permit fully on--off switching while at the same time obviating the need for bias monitoring and feedback control.

  18. Above-threshold ionization of diatomic molecules by few-cycle laser pulses

    SciTech Connect (OSTI)

    Gazibegovic-Busuladzic, A. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Hasovic, E. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Str. 2a, D-12489 Berlin (Germany); Busuladzic, M. [Medical Faculty, University of Sarajevo, Cekalusa 90, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Str. 2a, D-12489 Berlin (Germany); Academy of Sciences and Arts of Bosnia and Herzegovina Bistrik 7, 71000 Sarajevo (Bosnia and Herzegowina); Kelkensberg, F.; Siu, W. K. [FOM-Institute AMOLF, Science park 104, NL-1098 XG Amsterdam (Netherlands); Vrakking, M. J. J. [Max-Born-Institut, Max-Born-Str. 2a, D-12489 Berlin (Germany); FOM-Institute AMOLF, Science park 104, NL-1098 XG Amsterdam (Netherlands); Lepine, F. [Universite Lyon 1 (France); CNRS (France); LASIM, UMR 5579, 43 bvd. du 11 novembre 1918, F-69622 Villeurbanne (France); Sansone, G.; Nisoli, M. [Politecnico di Milano, Department of Physics, National Research Council of Italy, Institute of Photonics and Nanotechnologies (CNR-IFN), Piazza L. da Vinci 32, I-20133, Milano (Italy); Znakovskaya, I. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Str. 1, D-85748 Garching (Germany); Kling, M. F. [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Str. 1, D-85748 Garching (Germany); J.R. Macdonald Laboratory, Kansas State University, Manhattan, Kansas 66506 (United States)

    2011-10-15T23:59:59.000Z

    Above-threshold ionization of diatomic molecules by infrared carrier-envelope phase (CEP) stable few-cycle laser pulses is analyzed both experimentally and theoretically. The theoretical approach is based on the recently developed molecular improved strong-field approximation (ISFA), generalized to few-cycle pulses. Instead of using the first Born approximation, the rescattering matrix element in the ISFA is now calculated exactly. This modification leads to the appearance of characteristic minima in the differential cross section as a function of the scattering angle. Experimental angle-resolved photoelectron spectra of N{sub 2} and O{sub 2} molecules are obtained using the velocity map imaging technique. A relatively good agreement of experimental and simulated angle-resolved spectra, CEP-dependent asymmetry maps, and extracted electron-molecular ion elastic scattering differential cross sections is obtained.

  19. Uncertainties of optical-model parameters for the study of the threshold anomaly

    E-Print Network [OSTI]

    Daniel Abriola; A. Arazi; J. Testoni; F. Gollan; G. V. Martí

    2015-03-13T23:59:59.000Z

    In the analysis of elastic-scattering experimental data, optical-model parameters (usually, depths of real and imaginary potentials) are fitted and conclusions are drawn analyzing their variations at bombardment energies close to the Coulomb barrier (threshold anomaly). The judgement about the shape of this variation (related to the physical processes producing this anomaly) depends on these fitted values but the robustness of the conclusions strongly depends on the uncertainties with which these parameters are derived. We will show that previous published studies have not used a common criterium for the evaluation of the parameter uncertainties. In this work, a study of these uncertainties is presented, using conventional statistic tools as well as bootstrapping techniques. As case studies, these procedures are applied to re-analyze detailed elastic-scattering data for the $^{12}$C + $^{208}$Pb and the $^6$Li + $^{80}$Se systems.

  20. Violations of Lorentz invariance in the neutrino sector: an improved analysis of anomalous threshold constraints

    E-Print Network [OSTI]

    Luca Maccione; Stefano Liberati; David M. Mattingly

    2013-03-11T23:59:59.000Z

    Recently there has been a renewed activity in the physics of violations of Lorentz invariance in the neutrino sector. Flavor dependent Lorentz violation, which generically changes the pattern of neutrino oscillations, is extremely tightly constrained by oscillation experiments. Flavor independent Lorentz violation, which does not introduce new oscillation phenomena, is much more weakly constrained with constraints coming from time of flight and anomalous threshold analyses. We use a simplified rotationally invariant model to investigate the effects of finite baselines and energy dependent dispersion on anomalous reaction rates in long baseline experiments and show numerically that anomalous reactions do not necessarily cut off the spectrum quite as sharply as currently assumed. We also present a revised analysis of how anomalous reactions can be used to cast constraints from the observed atmospheric high energy neutrinos and the expected cosmogenic ones.

  1. Measurement of the generalized form factors near threshold via ?*p ? n?+ at high Q2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Park, K; Adhikari, K P; Adikaram, D; Anghinolfi, M; Baghdasaryan, H; Ball, J; Battaglieri, M; Batourine, V; Bedlinskiy, I; Bennett, R P; et al

    2012-03-26T23:59:59.000Z

    We report the first extraction of the pion-nucleon multipoles near the production threshold for the n?+ channel at relatively high momentum transfer (Q2 up to 4.2 GeV2). The dominance of the s-wave transverse multipole (E0+), expected in this region, allowed us to access the generalized form factor G1 within the light-cone sum rule (LCSR) framework as well as the axial form factor GA. The data analyzed in this work were collected by the nearly 4? CEBAF Large Acceptance Spectrometer (CLAS) using a 5.754-GeV electron beam on a proton target. The differential cross section and the ?-N multipole E0+/GD were measuredmore »using two different methods, the LCSR and a direct multipole fit. The results from the two methods are found to be consistent and almost Q2 independent.« less

  2. Attosecond electron pulses from interference of above-threshold de Broglie waves

    E-Print Network [OSTI]

    Sandor Varro; Gyozo Farkas

    2007-05-02T23:59:59.000Z

    It is shown that the the interference of above-threshold electron de Broglie waves, generated by an intense laser pulse at a metal surface yields attosecond electron pulses. This inerference is an analogon of the superposition of high harmonics generated from rare gas atoms, resulting in trains of attosecond light pulses.Owing to the inherent kinematic dispersion, the propagation of attosecond de Broglie waves in vacuum is very different from that of attosecond light pulses, which propagate without changing shape. Above the metal surface there are "collaps bands" and "revival layers" of the electron current even at macroscopic distances. In the range of parameters considered, the maximum value of the current densities of such ultrashort electron pulses has been estimated to be of order of couple of tenths of milliamps per square centimeters.

  3. Rescattering Effect and Near Threshold Enhancement of $p\\bar p$ System

    E-Print Network [OSTI]

    G. Y. Chen; H. R. Dong; J. P. Ma

    2008-06-28T23:59:59.000Z

    We study the observed enhancement of a $p\\bar p$ system near the threshold in the process $J/\\psi \\to \\gamma p\\bar p$ and $e^+ e^- \\to p\\bar p$. From early studies the enhancement can be explained by final state interactions, which are in general taken into account with some potential models. In this work we offer a simple approach within quantum field theory to explain the observed enhancement. We point out that among different final state interactions the rescattering in a $N\\bar N$ system though exchange of $\\pi$ is the most important. The effects of the rescattering is completely fixed by the well-known coupling $g_{\\pi NN}$. Our results show that the enhancement in $J/\\psi \\to \\gamma p\\bar p$ and $e^+ e^- \\to p\\bar p$ can be well described with the rescattering effects.

  4. Measurement of the generalized form factors near threshold via ?*p ? n?+ at high Q2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Park, K; Adhikari, K P; Adikaram, D; Anghinolfi, M; Baghdasaryan, H; Ball, J; Battaglieri, M; Batourine, V; Bedlinskiy, I; Bennett, R P; Biselli, A S; Bookwalter, C; Boiarinov, S; Branford, D; Briscoe, W J; Brooks, W K; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Cole, P L; Contalbrigo, M; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Doughty, D; Dupre, R; El Alaoui, A; El Fassi, L; Euginio, P; Fedotov, G; Fradi, A; Gabrielyan, M Y; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Graham, L; Griffioen, K A; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Heddle, D; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jenkins, D; Jo, H S; Joo, K; Khandaker, M; Khertarpal, P; Kim, A; Kim, W; Klein, F J; Kubarovsky, A; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, J D; Markov, N; Mayer, M; McKinnon, B; Mestayer, M D; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Paolone, M; Pappalardo, L; Paremuzyan, R; Park, S; Anefalos Pereira, S; Phelps, E; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Prok, Y; Ricco, G; Rimal, D; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Sabati ee, F; Saini, M S; Salgado, C; Schott, D; Schumacher, R A; Seraydaryan, H; Sharabian, Y G; Smith, E S; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tang, W; Taylor, C E; Tian, Y; Tkachenko, S; Trivedi, A; Ungaro, M; Vernarsky, B; Vlassov, A V; Voutier, E; Watts, D P; Weygand, D P; Wood, M H; Zachariou, N; Zhao, B; Zhao, Z W

    2012-03-26T23:59:59.000Z

    We report the first extraction of the pion-nucleon multipoles near the production threshold for the n?+ channel at relatively high momentum transfer (Q2 up to 4.2 GeV2). The dominance of the s-wave transverse multipole (E0+), expected in this region, allowed us to access the generalized form factor G1 within the light-cone sum rule (LCSR) framework as well as the axial form factor GA. The data analyzed in this work were collected by the nearly 4? CEBAF Large Acceptance Spectrometer (CLAS) using a 5.754-GeV electron beam on a proton target. The differential cross section and the ?-N multipole E0+/GD were measured using two different methods, the LCSR and a direct multipole fit. The results from the two methods are found to be consistent and almost Q2 independent.

  5. Measurement of the generalized form factors near threshold via $?^* p \\to n?^+$ at high $Q^2$

    E-Print Network [OSTI]

    Kijun Park; Ralf Gothe; Krishna Adhikari; Dasuni Adikaram-Mudiyanselage; Marco Anghinolfi; Hovhannes Baghdasaryan; Jacques Ball; Marco Battaglieri; Vitaly Baturin; Ivan Bedlinskiy; Robert Bennett; Angela Biselli; Craig Bookwalter; Sergey Boyarinov; Derek Branford; William Briscoe; William Brooks; Volker Burkert; Daniel Carman; Andrea Celentano; Shloka Chandavar; Gabriel Charles; Philip Cole; Marco Contalbrigo; Volker Crede; Annalisa D'Angelo; Aji Daniel; Natalya Dashyan; Raffaella De Vita; Enzo De Sanctis; Alexandre Deur; Chaden Djalali; David Doughty; Raphael Dupre; Ahmed El Alaoui; Lamiaa Elfassi; Paul Eugenio; Gleb Fedotov; Ahmed Fradi; Marianna Gabrielyan; Nerses Gevorgyan; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Wesley Gohn; Evgeny Golovach; Lewis Graham; Keith Griffioen; Michel Guidal; Lei Guo; Kawtar Hafidi; Hayk Hakobyan; Charles Hanretty; David Heddle; Kenneth Hicks; Maurik Holtrop; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Evgeny Isupov; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Mahbubul Khandaker; Puneet Khetarpal; Andrey Kim; Wooyoung Kim; Andreas Klein; Franz Klein; A. Kubarovsky; Valery Kubarovsky; Sebastian Kuhn; Sergey Kuleshov; Nicholas Kvaltine; Kenneth Livingston; Haiyun Lu; Ian MacGregor; Nikolai Markov; Michael Mayer; Bryan McKinnon; Mac Mestayer; Curtis Meyer; Taisiya Mineeva; Marco Mirazita; Viktor Mokeev; Herve Moutarde; Edwin Munevar Espitia; Pawel Nadel-Turonski; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Mikhail Osipenko; Alexander Ostrovidov; Michael Paolone; Luciano Pappalardo; Rafayel Paremuzyan; Seungkyung Park; Sergio Pereira; Evan Phelps; Silvia Pisano; Oleg Pogorelko; Sergey Pozdnyakov; John Price; Sebastien Procureur; Yelena Prok; Giovanni Ricco; Dipak Rimal; Marco Ripani; Barry Ritchie; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Mukesh Saini; Carlos Salgado; Diane Schott; Reinhard Schumacher; Heghine Seraydaryan; Youri Sharabian; Elton Smith; Gregory Smith; Daniel Sober; Daria Sokhan; Samuel Stepanyan; Stepan Stepanyan; Paul Stoler; Igor Strakovski; Steffen Strauch; Mauro Taiuti; Wei Tang; Charles Taylor; Ye Tian; Svyatoslav Tkachenko; Arjun Trivedi; Maurizio Ungaro; Brian Vernarsky; Alexander Vlasov; Eric Voutier; Daniel Watts; Dennis Weygand; Michael Wood; Nicholas Zachariou; Bo Zhao; Zhiwen Zhao; N. Kalantarians; C. E. Hyde

    2012-02-21T23:59:59.000Z

    We report the first extraction of the pion-nucleon multipoles near the production threshold for the $n\\pi^+$ channel at relatively high momentum transfer ($Q^2$ up to 4.2 $\\rm{GeV^2}$). The dominance of the s-wave transverse multipole ($E_{0+}$), expected in this region, allowed us to access the generalized form factor $G_1$ within the light-cone sum rule (LCSR) framework as well as the axial form factor $G_A$. The data analyzed in this work were collected by the nearly $4\\pi$ CEBAF Large Acceptance Spectrometer (CLAS) using a 5.754 $\\rm{GeV}$ electron beam on a proton target. The differential cross section and the $\\pi-N$-multipole $E_{0+}/G_D$ were measured using two different methods, the LCSR and a direct multipole fit. The results from the two methods are found to be consistent and almost $Q^2$ independent.

  6. Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices ?

    E-Print Network [OSTI]

    I. Adachi; T. Sumiyoshi; K. Hayashi; N. Iida; R. Enomoto; K. Tsukada; R. Suda; S. Matsumoto; K. Natori; M. Yokoyama; H. Yokogawa

    1994-01-01T23:59:59.000Z

    To identify ? ± and K ± in the region of 1.0 ? 2.5 GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to ?/K separation up to a few GeV/c with an efficiency greater than 90 % was considered. 1

  7. Influence of cleaning process on the laser-induced damage threshold of substrates

    SciTech Connect (OSTI)

    Shen Zhengxiang; Ding Tao; Ye Xiaowen; Wang Xiaodong; Ma Bin; Cheng Xinbin; Liu Huasong; Ji Yiqin; Wang Zhanshan

    2011-03-20T23:59:59.000Z

    The cleaning process of optical substrates plays an important role during the manufacture of high-power laser coatings. Two kinds of substrates, fused silica and BK7 glass, and two cleaning processes, called process 1 and process 2 having different surfactant solutions and different ultrasonic cleaning parameters, are adopted to compare the influence of the ultrasonic cleaning technique on the substrates. The evaluation standards of the cleaning results include contaminant-removal efficiency, weak absorption, and laser-induced damage threshold of the substrates. For both fused silica and BK7, process 2 is more efficient than process 1. Because acid and alkaline solutions can increase the roughness of BK7, process 2 is unsuitable for BK7 glass cleaning. The parameters of the cleaning protocol should be changed depending on the material of the optical components and the type of contamination.

  8. Observed Minimum Illuminance Threshold for Night Market Vendors in Kenya who use LED Lamps

    SciTech Connect (OSTI)

    Johnstone, Peter; Jacobson, Arne; Mills, Evan; Radecsky, Kristen

    2009-03-21T23:59:59.000Z

    Creation of light for work, socializing, and general illumination is a fundamental application of technology around the world. For those who lack access to electricity, an emerging and diverse range of LED based lighting products hold promise for replacing and/or augmenting their current fuel-based lighting sources that are costly and dirty. Along with analysis of environmental factors, economic models for total cost-ofownership of LED lighting products are an important tool for studying the impacts of these products as they emerge in markets of developing countries. One important metric in those models is the minimum illuminance demanded by end-users for a given task before recharging the lamp or replacing batteries. It impacts the lighting service cost per unit time if charging is done with purchased electricity, batteries, or charging services. The concept is illustrated in figure 1: LED lighting products are generally brightest immediately after the battery is charged or replaced and the illuminance degrades as the battery is discharged. When a minimum threshold level of illuminance is reached, the operational time for the battery charge cycle is over. The cost to recharge depends on the method utilized; these include charging at a shop at a fixed price per charge, charging on personal grid connections, using solar chargers, and purchasing dry cell batteries. This Research Note reports on the observed"charge-triggering" illuminance level threshold for night market vendors who use LED lighting products to provide general and task oriented illumination. All the study participants charged with AC power, either at a fixed-price charge shop or with electricity at their home.

  9. Ablation experiment and threshold calculation of titanium alloy irradiated by ultra-fast pulse laser

    SciTech Connect (OSTI)

    Zheng, Buxiang; Jiang, Gedong; Wang, Wenjun, E-mail: wenjunwang@mail.xjtu.edu.cn; Wang, Kedian; Mei, Xuesong [School of Mechanical Engineering, Xi'an Jiaotong University, No. 28, Xianning Westroad, Xi'an 710049 (China) [School of Mechanical Engineering, Xi'an Jiaotong University, No. 28, Xianning Westroad, Xi'an 710049 (China); State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710054 (China)

    2014-03-15T23:59:59.000Z

    The interaction between an ultra-fast pulse laser and a material's surface has become a research hotspot in recent years. Micromachining of titanium alloy with an ultra-fast pulse laser is a very important research direction, and it has very important theoretical significance and application value in investigating the ablation threshold of titanium alloy irradiated by ultra-fast pulse lasers. Irradiated by a picosecond pulse laser with wavelengths of 1064 nm and 532 nm, the surface morphology and feature sizes, including ablation crater width (i.e. diameter), ablation depth, ablation area, ablation volume, single pulse ablation rate, and so forth, of the titanium alloy were studied, and their ablation distributions were obtained. The experimental results show that titanium alloy irradiated by a picosecond pulse infrared laser with a 1064 nm wavelength has better ablation morphology than that of the green picosecond pulse laser with a 532 nm wavelength. The feature sizes are approximately linearly dependent on the laser pulse energy density at low energy density and the monotonic increase in laser pulse energy density. With the increase in energy density, the ablation feature sizes are increased. The rate of increase in the feature sizes slows down gradually once the energy density reaches a certain value, and gradually saturated trends occur at a relatively high energy density. Based on the linear relation between the laser pulse energy density and the crater area of the titanium alloy surface, and the Gaussian distribution of the laser intensity on the cross section, the ablation threshold of titanium alloy irradiated by an ultra-fast pulse laser was calculated to be about 0.109 J/cm{sup 2}.

  10. Threshold-Resummed Cross Section for the Drell-Yan Process in Pion-Nucleon Collisions at COMPASS

    E-Print Network [OSTI]

    Matthias Aicher; Andreas Schäfer; Werner Vogelsang

    2011-04-18T23:59:59.000Z

    We present a study of the Drell-Yan process in pion-proton collisions including next-to-leading-logarithmic threshold-resummed contributions. We analyze rapidity-integrated as well as rapidity-differential cross sections in the kinematic regime relevant for the COMPASS fixed target experiment. We find that resummation leads to a significant enhancement of the cross section compared to fixed-order calculations in this regime. Particularly large corrections arise at large forward and backward rapidities of the lepton pair. We also study the scale dependence of the cross section and find it to be substantially reduced by threshold resummation.

  11. The Chandrasekhar limit for quark stars

    E-Print Network [OSTI]

    Shibaji Banerjee; Sanjay K. Ghosh; Sibaji Raha

    2000-01-14T23:59:59.000Z

    The Chandrasekhar limit for quark stars is evaluated from simple energy balance relations, as proposed by Landau for white dwarfs or neutron stars. It has been found that the limit for quark stars depends on, in addition to the fundamental constants, the Bag constant.

  12. Self-triggering superconducting fault current limiter

    DOE Patents [OSTI]

    Yuan, Xing (Albany, NY); Tekletsadik, Kasegn (Rexford, NY)

    2008-10-21T23:59:59.000Z

    A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

  13. Upper limits for undetected trace species in the stratosphere of Titan

    SciTech Connect (OSTI)

    Nixon, Connor A.; Achterberg, Richard K.; Teanby, Nicholas A.; Irwin, Patrick G.; Flaud, Jean Marie; Kleiner, I.; Dehayem-kamadjeu, A.; Brown, Linda R.; Sams, Robert L.; Bezard, Bruno; Coustenis, Athena; Ansty, Todd M.; Mamoutkine, Andrei; Vinatier, Sandrine; Bjoraker, Gordon L.; Jennings, Donald E.; Romani, Paul N.; Flasar, F. M.

    2010-11-01T23:59:59.000Z

    In this paper we describe a first quantitative search for several molecules in Titans stratosphere ni Cassini CIRS infrared spectra. These are: ammonia (NH3), methanol (CH3OH), formaldehyde (H2CO), and acetonitrile (CH3CN), all of which are predicted by photochemical models but only the last of which observed, and not in the infrared,. We find non-detections in all cases, but derive upper limits on the abundances from low-noise observations at 25 degreesS and 75 degreesN. Comparing these constraints to model predictions, we conclude that CIRS is highly unlikely to see NH3 or CH3OH emissions. However, CH3CN and H2CO are closer to CIRS detectability, and we suggest ways in which the sensitivity threshold may be lowered towards this goal.

  14. Long-time limit of correlation functions

    E-Print Network [OSTI]

    Thomas Franosch

    2014-07-31T23:59:59.000Z

    Auto-correlation functions in an equilibrium stochastic process are well-characterized by Bochner's theorem as Fourier transforms of a finite symmetric Borel measure. The existence of a long-time limit of these correlation functions depends on the spectral properties of the measure. Here we provide conditions applicable to a wide-class of dynamical theories guaranteeing the existence of the long-time limit. We discuss the implications in the context of the mode-coupling theory of the glass transition where a non-trivial long-time limit signals an idealized glass state.

  15. Limit of light coupling into solar cells

    E-Print Network [OSTI]

    Naqavi, A; Ballif, C; Scharf, T; Herzig, H P

    2013-01-01T23:59:59.000Z

    We introduce a limit for the strength of coupling light into the modes of solar cells. This limit depends on both a cell's thickness and its modal properties. For a cell with refractive index n and thickness d, we obtain a maximal coupling rate of 2c*sqrt(n^2-1)/d where c is speed of light. Our method can be used in the design of solar cells and in calculating their efficiency limits; besides, it can be applied to a broad variety of resonant phenomena and devices.

  16. The vibrational energies of ozone up to the dissociation threshold: Dynamics calculations on an accurate potential energy surface

    E-Print Network [OSTI]

    Farantos, Stavros C.

    The vibrational energies of ozone up to the dissociation threshold: Dynamics calculations present an ab initio potential energy surface for the ground electronic state of ozone. It is global, i. All bound states of nonrotating ozone up to more than 99% of the dissociation energy are calculated

  17. Damage Threshold of Platinum Coating used for Optics for Self-Seeding of Soft X-ray Free Electron Laser

    SciTech Connect (OSTI)

    Krzywinski, Jacek; Cocco, Daniele; Moeller, Stefan; Ratner, Daniel

    2015-01-01T23:59:59.000Z

    We investigated the experimental damage threshold of platinum coating on a silicon substrate illuminated by soft x-ray radiation at grazing incidence angle of 2.1 deg. The coating was the same as the blazed grating used for the soft X-ray self-seeding optics of the Linac Coherent Light Source free electron laser. The irradiation condition was chosen such that the absorbed dose was similar to the maximum dose expected for the grating. The expected dose was simulated by solving the Helmholtz equation in non-homogenous media. The experiment was performed at 900 eV photon energy for both single pulse and multi-shot conditions. We have not observed single shot damage. This corresponds to a single shot damage threshold being higher than 3 J/cm2. The multiple shot damage threshold measured for 10 shots and about 600 shots was determined to be 0.95 J/cm2 and 0.75 J/cm2 respectively. The damage threshold occurred at an instantaneous dose which is higher that the melt dose of platinum.

  18. Damage Threshold of Platinum Coating used for Optics for Self-Seeding of Soft X-ray Free Electron Laser

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Krzywinski, Jacek; Cocco, Daniele; Moeller, Stefan; Ratner, Daniel

    2015-01-01T23:59:59.000Z

    We investigated the experimental damage threshold of platinum coating on a silicon substrate illuminated by soft x-ray radiation at grazing incidence angle of 2.1 deg. The coating was the same as the blazed grating used for the soft X-ray self-seeding optics of the Linac Coherent Light Source free electron laser. The irradiation condition was chosen such that the absorbed dose was similar to the maximum dose expected for the grating. The expected dose was simulated by solving the Helmholtz equation in non-homogenous media. The experiment was performed at 900 eV photon energy for both single pulse and multi-shot conditions. Wemore »have not observed single shot damage. This corresponds to a single shot damage threshold being higher than 3 J/cm2. The multiple shot damage threshold measured for 10 shots and about 600 shots was determined to be 0.95 J/cm2 and 0.75 J/cm2 respectively. The damage threshold occurred at an instantaneous dose which is higher that the melt dose of platinum.« less

  19. Low-threshold, mirrorless emission at 981 nm in an Yb,Gd,Lu:KYW inverted rib waveguide laser

    E-Print Network [OSTI]

    Low-threshold, mirrorless emission at 981 nm in an Yb,Gd,Lu:KYW inverted rib waveguide laser Amol for generating short pulses [2]. Liquid phase epitaxy has been used to fabricate planar [3, 4] and channel [5, 6W and a channel waveguide laser with an output power of 11 mW [9]. In this paper we demonstrate mirrorless lasing

  20. Threshold Pressure for Disappearance of Size-Induced Effect in Spinel-Structure Ge3N4 Nanocrystals

    E-Print Network [OSTI]

    Downs, Robert T.

    Threshold Pressure for Disappearance of Size-Induced Effect in Spinel-Structure Ge3N4 Nanocrystals demonstrate that the incompressibility of spinel Ge3N4 nanocrystals decreases when the pressure is elevated above 20 GPa. Ge3N4 nanocrystals initially exhibit a higher bulk modulus of 381(2) GPa. But, above 20

  1. A Thermally-Aware Methodology for Design-Specific Optimization of Supply and Threshold Voltages in Nanometer Scale ICs

    E-Print Network [OSTI]

    411 A Thermally-Aware Methodology for Design-Specific Optimization of Supply and Threshold Voltages and associated thermal effects have strong impact on the packaging, cooling costs, and reliability for deep submicron technologies [2-5]. For power-constrained applications, lowering supply voltage (Vdd) offers

  2. A peaks-over-threshold analysis of extreme traffic load effects on bridges Franziska Schmidt, Xiao Yi Zhou, Franois Toutlemonde

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    extreme traffic load or traffic load effect. These are: i. a half-normal curve fitted to the end1 A peaks-over-threshold analysis of extreme traffic load effects on bridges Franziska Schmidt focuses on modeling and estimating tail parameters of bridge traffic load effects by generalized Pareto

  3. Comparison of near-threshold reactivity of ground-state and spin-orbit excited chlorine atoms with methane

    E-Print Network [OSTI]

    Zare, Richard N.

    indicate that the Cl* CH4 reaction is unimportant in the near-threshold collision energy range of 0 at both low and high temperatures. Among other possible sources for this behavior, Ravishankara and Wine3. This postulate is based on the assump- tion that the extra spin-orbit energy 881 cm 1 of Cl* is available

  4. Oxygen and organic matter thresholds for benthic faunal activity on the Pakistan margin oxygen minimum zone (7001100 m)

    E-Print Network [OSTI]

    Levin, Lisa

    Oxygen and organic matter thresholds for benthic faunal activity on the Pakistan margin oxygen increased animal activity associated with increasing bottom-water oxygen concentration. We examined faunal community responses to oxygen and organic matter gradients across the lower oxygen minimum zone (OMZ

  5. Observation of a stripping threshold for the reaction N2 ^++CH4?N2H^++CH3

    E-Print Network [OSTI]

    Wyatt, J. R.; Strattan, L. W.; Snyder, S. C.; Hierl, Peter M.

    1976-01-01T23:59:59.000Z

    to possess a threshold at 0.1 eV. At the higher energies there is a large isotope effect favoring abstraction of H over D. The product velocity vector distribution is strongly peaked forward of the center of mass, indicating that the reaction is predominantly...

  6. Error Probabilities and Threshold Selection in Networked Nuclear Detection Chetan D. Pahlajani, Jianxin Sun, Ioannis Poulakakis, Herbert G. Tanner

    E-Print Network [OSTI]

    Poulakakis, Ioannis

    of nuclear detection relates to the problem of using radiation sensor data to decide, within a given time. Specifically, it is noted that currently deployed systems for detecting the transport of illicit radioactiveError Probabilities and Threshold Selection in Networked Nuclear Detection Chetan D. Pahlajani

  7. Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of benzene: Vibrational analysis of C6H6

    E-Print Network [OSTI]

    Kim, Myung Soo

    Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of benzene: Vibrational analysis-photon spectra agrees with the previous suggestion that the geometry of benzene cation in the ground electronic. INTRODUCTION Benzene cation has been the focus of an intensive re- search effort, both experimental1

  8. Damage Threshold of Platinum Coating used for Optics for Self-Seeding of Soft X-ray Free Electron Laser

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Krzywinski, Jacek; Cocco, Daniele; Moeller, Stefan; Ratner, Daniel

    2015-01-01T23:59:59.000Z

    We investigated the experimental damage threshold of platinum coating on a silicon substrate illuminated by soft x-ray radiation at grazing incidence angle of 2.1 deg. The coating was the same as the blazed grating used for the soft X-ray self-seeding optics of the Linac Coherent Light Source free electron laser. The irradiation condition was chosen such that the absorbed dose was similar to the maximum dose expected for the grating. The expected dose was simulated by solving the Helmholtz equation in non-homogenous media. The experiment was performed at 900 eV photon energy for both single pulse and multi-shot conditions. We have not observed single shot damage. This corresponds to a single shot damage threshold being higher than 3 J/cm2. The multiple shot damage threshold measured for 10 shots and about 600 shots was determined to be 0.95 J/cm2 and 0.75 J/cm2 respectively. The damage threshold occurred at an instantaneous dose which is higher that the melt dose of platinum.

  9. Damage threshold of inorganic solids under free-electron-laser irradiation at 32.5 nm wavelength

    E-Print Network [OSTI]

    von der Linde, D.

    to the optical components required to utilize XFEL beams, including radiation damage. Theoretical workDamage threshold of inorganic solids under free-electron-laser irradiation at 32.5 nm wavelength SC were exposed to single 25 fs long pulses of 32.5 nm free-electron-laser radiation at fluences of up

  10. Robust model-based detection of the lung field boundaries in portable chest radiographs supported by selective thresholding

    E-Print Network [OSTI]

    Athens, University of

    Robust model-based detection of the lung field boundaries in portable chest radiographs supported of the lung field boundaries in portable chest radiographs supported by selective thresholding D K Iakovidis1-ray misinterpretation rates. This paper presents a novel methodology for the detection of the lung field boundaries

  11. Investigation of the Cause of Low Blister Threshold Temperatures in the RERTR-12 and AFIP-4 Experiments

    SciTech Connect (OSTI)

    Mitchell K Meyer

    2012-06-01T23:59:59.000Z

    Blister–threshold testing of fuel plates is a standard method through which the safety margin for operation of plate-type in research and test reactors is assessed. The blister-threshold temperature is indicative of the ability of fuel to operate at high temperatures for short periods of time (transient conditions) without failure. This method of testing was applied to the newly developed U-Mo monolithic fuel system. Blister annealing studies on the U-Mo monolithic fuel plates began in 2007, with the Reduced Enrichment for Research and Test Reactors (RERTR)-6 experiment, and they have continued as the U-Mo fuel system has evolved through the research and development process. Blister anneal threshold temperatures from early irradiation experiments (RERTR-6 through RERTR-10) ranged from 400 to 500°C. These temperatures were projected to be acceptable for NRC-licensed research reactors and the high-power Advanced Test Reactor (ATR) and the High Flux Isotope Reactor (HFIR) based on current safety-analysis reports (SARs). Initial blister testing results from the RERTR-12 experiment capsules X1 and X2 showed a decrease in the blister-threshold temperatures. Blister threshold temperatures from this experiment ranged from 300 to 400°C. Selected plates from the AFIP-4 experiment, which was fabricated using a process similar to that used to fabricate the RERTR-12 experiment, also underwent blister testing to determine whether results would be similar. The measured blister-threshold temperatures from the AFIP-4 plates fell within the same blister-threshold temperature range measured in the RERTR-12 plates. Investigation of the cause of this decrease in bister threshold temperature is being conducted under the guidance of Idaho National Laboratory PLN-4155, “Analysis of Low Blister Threshold Temperatures in the RERTR-12 and AFIP-4 Experiments,” and is driven by hypotheses. The main focus of the investigation is in the following areas: 1. Fabrication variables 2. Pre-irradiation characterization 3. Irradiation conditions 4. Post-irradiation examination 5. Additional blister testing 6. Mechanical modeling This report documents the preliminary results of this investigation. Several hypotheses can be dismissed as a result of this investigation. Two primary categories of causes remain. The most prominent theory, supported by the data, is that low blister-threshold temperature is the result of mechanical energy imparted on the samples during the fabrication process (hot and cold rolling) without adequate post processing (annealing). The mechanisms are not clearly understood and require further investigation, but can be divided into two categories: • Residual Stress • Undesirable interaction boundary and/or U-Mo microstructure change A secondary theory that cannot be dismissed with the information that is currently available is that a change in the test conditions has resulted in a statistically significant downward shift of measured blister temperature. This report outlines the results of the forensic investigations conducted to date. The data and conclusions presented in this report are preliminary. Definitive cause and effect relationships will be established by future experimental programs.

  12. Quantum Cryptography Approaching the Classical Limit

    E-Print Network [OSTI]

    Weedbrook, Christian

    We consider the security of continuous-variable quantum cryptography as we approach the classical limit, i.e., when the unknown preparation noise at the sender’s station becomes significantly noisy or thermal (even by as ...

  13. Infinite volume limit for the dipole gas

    E-Print Network [OSTI]

    J. Dimock

    2009-04-28T23:59:59.000Z

    We consider a classical dipole gas in with low activity and show that the pressure has a limit as the volume goes to infinity. The result is obtained by a renormalization group analysis of the model.

  14. Heisenberg-limited metrology with information recycling

    E-Print Network [OSTI]

    Simon A. Haine; Stuart S. Szigeti; Matthias D. Lang; Carlton M. Caves

    2015-05-01T23:59:59.000Z

    Information recycling has been shown to improve the sensitivity of atom interferometers by exploiting atom-light entanglement. In this paper, we apply information recycling to an interferometer where the input quantum state has been partially transferred from some donor system. We demonstrate that when the quantum state of this donor system is from a particular class of number-correlated Heisenberg-limited states, information recycling yields a Heisenberg-limited phase measurement. Crucially, this result holds irrespective of the fraction of the quantum state transferred to the interferometer input and also for a general class of number-conserving quantum-state-transfer processes, including ones that destroy the first-order phase coherence between the branches of the interferometer. This result could have significant applications in Heisenberg-limited atom interferometry, where the quantum state is transferred from a Heisenberg-limited photon source, and in optical interferometry where the loss can be monitored.

  15. Can Eutrophication Influence Nitrogen vs. Phosphorus Limitation?

    E-Print Network [OSTI]

    Vallino, Joseph J.

    Can Eutrophication Influence Nitrogen vs. Phosphorus Limitation? George Gregory Bates College, originating largely from septic systems and fertilizers, have caused significant eutrophication in freshwater nitrogen and phosphorus grew the highest concentration of phytoplankton, but eutrophic ponds grew a mean

  16. Some Fundamental Limitations for Cognitive Radio

    E-Print Network [OSTI]

    Sahai, Anant

    ' & $ % Some Fundamental Limitations for Cognitive Radio Anant Sahai Wireless Foundations, UCB EECS program November 1 at BWRC Cognitive Radio Workshop #12;' & $ % Outline 1. Why cognitive radios? 2 November 1 at BWRC Cognitive Radio Workshop #12;' & $ % Apparent spectrum allocations · Traditional

  17. Diffusion-Limited Aggregation on Curved Surfaces

    E-Print Network [OSTI]

    Choi, J.

    We develop a general theory of transport-limited aggregation phenomena occurring on curved surfaces, based on stochastic iterated conformal maps and conformal projections to the complex plane. To illustrate the theory, we ...

  18. Climate Prediction: The Limits of Ocean Models

    E-Print Network [OSTI]

    Stone, Peter H.

    We identify three major areas of ignorance which limit predictability in current ocean GCMs. One is the very crude representation of subgrid-scale mixing processes. These processes are parameterized with coefficients whose ...

  19. Performance limits of axial turbomachine stages

    E-Print Network [OSTI]

    Hall, David Kenneth

    2011-01-01T23:59:59.000Z

    This thesis assesses the limits of stage efficiency for axial compressor and turbine stages. A stage model is developed, consisting of a specified geometry and a surface velocity distribution with turbulent boundary layers. ...

  20. Representation of Limited Rights Data and Restricted Computer...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Representation of Limited Rights Data and Restricted Computer Software Representation of Limited Rights Data and Restricted Computer Software Representation of Limited Rights Data...

  1. Limits of Equivalence: Thinking Gay Male Subjectivity Outside Feminist Theory

    E-Print Network [OSTI]

    Galloway, Samuel R.

    2010-01-01T23:59:59.000Z

    Limits of Equivalence: Thinking Gay Male Subjectivityor this limit of equivalence? The problem, of course, ispaper, the limits of equivalence emerge: while all subjects

  2. Inequality design limits in optimal aerodynamic shapes

    E-Print Network [OSTI]

    Seaman, Charles Knight

    1968-01-01T23:59:59.000Z

    ACKNOWLEDGMENTS I would like to thank Mr. Stan Lowy for his assistance. ABSTRACT The investigation is concerned with ways of including design con- straints in the problem of optimum aerodynamic shapes. Inequality constraints are examined in the report as one... means of describing design limits in the optimization problem. The use of inequality con- straints to consider design limits in a variational solution is illustrated with an example problem. In the example problem, the admissable profiles for a...

  3. Improved limits on scalar weak couplings

    SciTech Connect (OSTI)

    Adelberger, E.G. (PPE Division, CERN, CH-1211 Geneve 23 (Switzerland) Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))

    1993-05-10T23:59:59.000Z

    I point out that [beta]-delayed proton spectroscopy is a powerful probe of possible scalar contributions to nuclear [beta] decay, and use Schardt and Riisager's data on the shape of the beta-delayed proton peaks from the superallowed decays of [sup 32]Ar and [sup 33]Ar to set improved upper limits on such couplings. Implications of these limits for leptoquark masses are mentioned.

  4. Stack Sizing Analysis and Optimization for FinFET Logic Cells and Circuits Operating in the Sub/Near-Threshold Regime

    E-Print Network [OSTI]

    Pedram, Massoud

    -threshold regimes. This model accurately captures the drain current as a function of both the gate and drain-inversion region [10]. The drain current of a FinFET transistor in the super-threshold region follows the -power. Unfortunately, the EKV model is difficult to provide back- of-the-envelope insights and is difficult to work

  5. Does Beta React to Market Conditions?: Estimates of Bull and Bear Betas using a Nonlinear Market Model with Endogenous Threshold Parameter

    E-Print Network [OSTI]

    Kearns, Michael

    Does Beta React to Market Conditions?: Estimates of Bull and Bear Betas using a Nonlinear Market Model with Endogenous Threshold Parameter by George Woodward and Heather Anderson Department transition between bull and bear states and allows the data to determine the threshold value. The estimated

  6. IEEE TRANSACTIONS ON DEVICE AND MATERIALS RELIABILITY, VOL. 7, NO. 1, MARCH 2007 181 Impact of Strain or Ge Content on the Threshold

    E-Print Network [OSTI]

    Kumar, M. Jagadesh

    of Strain or Ge Content on the Threshold Voltage of Nanoscale Strained-Si/SiGe Bulk MOSFETs M. Jagadesh--The impact of strain on the threshold voltage of nanoscale strained-Si/SiGe MOSFETs is studied by developing a compact analytical model. Our model includes the effects of strain (Ge mole fraction in SiGe substrate

  7. One-Photon Mass-Analyzed Threshold Ionization Spectroscopy of Bis(6-benzene)chromium and Its Benzene and Ar Clusters

    E-Print Network [OSTI]

    Kim, Sang Kyu

    One-Photon Mass-Analyzed Threshold Ionization Spectroscopy of Bis(6-benzene)chromium and Its Benzene and Ar Clusters Kyo-Won Choi and Sang Kyu Kim* Department of Chemistry and School of Molecular-analyzed threshold ionization (MATI) spectroscopy of bis(6-benzene)chromium is reported. The adiabatic ionization

  8. STAR FORMATION LAWS AND THRESHOLDS FROM INTERSTELLAR MEDIUM STRUCTURE AND TURBULENCE

    SciTech Connect (OSTI)

    Renaud, Florent; Kraljic, Katarina; Bournaud, Frederic, E-mail: florent.renaud@cea.fr [Laboratoire AIM Paris-Saclay, CEA/IRFU/SAp, Universite Paris Diderot, F-91191 Gif-sur-Yvette Cedex (France)

    2012-11-20T23:59:59.000Z

    We present an analytical model of the relation between the surface density of gas and star formation rate in galaxies and clouds, as a function of the presence of supersonic turbulence and the associated structure of the interstellar medium (ISM). The model predicts a power-law relation of index 3/2, flattened under the effects of stellar feedback at high densities or in very turbulent media, and a break at low surface densities when ISM turbulence becomes too weak to induce strong compression. This model explains the diversity of star formation laws and thresholds observed in nearby spirals and their resolved regions, the Small Magellanic Cloud, high-redshift disks and starbursting mergers, as well as Galactic molecular clouds. While other models have proposed interstellar dust content and molecule formation to be key ingredients to the observed variations of the star formation efficiency, we demonstrate instead that these variations can be explained by ISM turbulence and structure in various types of galaxies.

  9. Experimental onset threshold and magnetic pressure pileup for 3D Sweet-Parker reconnection

    SciTech Connect (OSTI)

    Intrator, Thomas P [Los Alamos National Laboratory; Sun, Xuan [Los Alamos National Laboratory; Lapenta, Giovanni [Los Alamos National Laboratory; Furno, Ivo [Los Alamos National Laboratory; [NON LANL

    2008-01-01T23:59:59.000Z

    In space, astrophysical and laboratory plasmas, magnetic reconnect ion converts magnetic into particle energy during unsteady, explosive events. The abrupt onset and cessation has been a long standing puzzle. We show the first three-dimensional (3D) laboratory example of onset and stagnation of Sweet-Parker type magnetic reconnection between magnetized and parallel current (flux) ropes driven by magnetohydrodynamic (MHD) attraction and 3D instability. Mutually attracting flux ropes advect and merge oppositely directed magnetic fields. Magnetic flux is annihilated, but reaches soon a threshold where magnetic flux and pressure pile up, and reconnection magnetic topology appears. This occurs when inflow speeds exceed the SweetParker speed v{sub SP} = v{sub A} / S{sup 1/2}, where v{sub A} is the Alfven speed and S is the Lundquist number for the reconnection layer, as magnetic flux arrives faster than flux annihilation can process it. Finally piled up fields generate MHD reaction forces that stall the inflow and the reconnection process.

  10. Phase space path-integral formulation of the above-threshold ionization

    SciTech Connect (OSTI)

    Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina) [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Academy of Sciences and Arts of Bosnia and Herzegovina, Bistrik 7, 71000 Sarajevo (Bosnia and Herzegowina)

    2013-04-15T23:59:59.000Z

    Atoms and molecules submitted to a strong laser field can emit electrons of high energies in the above-threshold ionization (ATI) process. This process finds a highly intuitive and also quantitative explanation in terms of Feynman's path integral and the concept of quantum orbits [P. Salieres et al., Science 292, 902 (2001)]. However, the connection with the Feynman path-integral formalism is explained only by intuition and analogy and within the so-called strong-field approximation (SFA). Using the phase space path-integral formalism we have obtained an exact result for the momentum-space matrix element of the total time-evolution operator. Applying this result to the ATI we show that the SFA and the so-called improved SFA are, respectively, the zeroth- and the first-order terms of the expansion in powers of the laser-free effective interaction of the electron with the rest of the atom (molecule). We have also presented the second-order term of this expansion which is responsible for the ATI with double scattering of the ionized electron.

  11. Observation of abnormally large radii of nuclei in excited states in the vicinity of neutron thresholds

    SciTech Connect (OSTI)

    Ogloblin, A. A., E-mail: ogloblina@bk.ru; Danilov, A. N. [Russian Research Centre Kurchatov Institute (Russian Federation); Belyaeva, T. L. [Universidad Nacional Autonoma de Mexico (UNAM) (Mexico); Demyanova, A. S. [Russian Research Centre Kurchatov Institute (Russian Federation); Goncharov, S. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Trzaska, W. [University of Jyvaeskylae (Finland)

    2011-11-15T23:59:59.000Z

    Differential cross sections for inelastic scattering leading to the excitation of some nuclear states situated near neutron-emission thresholds were analyzed. With the aid of a modified diffraction model, abnormally large radii were found for the 1/2{sub 1}{sup +} state of the {sup 13}C nucleus at 3.09 MeV, for the first levels of positive-parity rotational bands in the {sup 9}Be (1/2{sup +} level at 1.68 MeV and 5/2{sup +} level at 3.05 MeV) and {sup 11}Be (5/2{sup +} level at 1.78 MeV and 3/2{sup +} level at 3.41 MeV) nuclei, and for the 2{sub 1}{sup +} state of the {sup 14}Be nucleus at 1.54 MeV and 1{sub 1}{sup -} state of the {sup 12}Be nucleus at 2.7 MeV. All of these states possess signatures typical of neutron halos.

  12. A Threshold Gas \\v{C}erenkov Detector for the Spin Asymmetries of the Nucleon Experiment

    E-Print Network [OSTI]

    Armstrong, Whitney R; Kaczanowicz, Ed; Lukhanin, Alexander; Meziani, Zein-Eddine; Sawatzky, Brad

    2015-01-01T23:59:59.000Z

    We report on the design, construction, commissioning, and performance of a threshold gas \\v{C}erenkov counter in an open configuration, which operates in a high luminosity environment and produces a high photo-electron yield. Part of a unique open geometry detector package known as the Big Electron Telescope Array, this \\v{C}erenkov counter served to identify scattered electrons and reject produced pions in an inclusive scattering experiment known as the Spin Asymmetries of the Nucleon Experiment E07-003 at the Thomas Jefferson National Accelerator Facility (TJNAF) also known as Jefferson Lab. The experiment consisted of a measurement of double spin asymmetries $A_{\\parallel}$ and $A_{\\perp}$ of a polarized electron beam impinging on a polarized ammonia target. The \\v{C}erenkov counter's performance is characterised by a yield of about 20 photoelectrons per electron or positron track. Thanks to this large number of photoelectrons per track, the \\v{C}erenkov counter had enough resolution to identify electron-p...

  13. High-order above-threshold ionization of argon: Plateau resonances and the Floquet quasienergy spectrum

    SciTech Connect (OSTI)

    Potvliege, R. M.; Vucic, Svetlana [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Institute of Physics, Pregrevica 118, 11080 Belgrade-Zemun (Serbia and Montenegro)

    2006-08-15T23:59:59.000Z

    The Floquet quasienergy spectrum of argon in a strong laser field of 800 nm wavelength is calculated for intensities up to 7x10{sup 13} W cm{sup -2}, and beyond for some states, using a discrete complex basis set. Many of the dressed excited states of interest shift nonponderomotively in complicated ways but keep an ionization width narrow enough to produce sharp enhancements of above-threshold ionization (ATI) through Stark-shift-induced resonances. The quasienergy map is compared to high-resolution ATI spectra for 120 fs Ti:sapphire pulses [Nandor et al., Phys. Rev. A 60, R1771 (1999)]. The plateau enhancements happen at intensities where the dressed ground state is in resonance or in the wing of resonances with dressed excited states. The resonant dressed states are identified. In many cases, the same state is responsible for an enhancement of ATI in the low as well as the high orders. No evidence is found for enhancements that are not concomitant with any curve crossing and could thereby be interpreted as channel-closing enhancement.

  14. Flow-induced tube vibration thresholds in heat exchangers from shellside water tests

    SciTech Connect (OSTI)

    Halle, H.; Chenoweth, J.M.; Wambsganss, M.W.

    1984-01-01T23:59:59.000Z

    Typical industrial shell-and-tube heat exchanger configurations are investigated experimentally for the occurrence of potentially damaging tube vibration as a function of flowrate. The effort is part of a program to develop vibration avoidance criteria to be integrated and optimized with the advanced thermal, hydraulic, and mechanical design methods now available. The tests use a 0.6-m (2-ft)-diameter, 3.7-m (12-ft)-long shell containing a removable tube bundle whose components are readily rearranged or replaced. The 15 different full tube bundle configurations tested represent various combinations of parameters: triangular or square tube layout patterns with different orientations to the flow, number of crosspasses, sizes of nozzles, plain or finned tubes. All bundles have 19-mm (0.75-in.)-diameter tubes spaced with a pitch-to-diameter ratio of 1.25. The heat exchanger is tested with waterflow on the shellside to determine a critical threshold, above which a small increase in the flowrate initiates a fluidelastic instability resulting in large amplitude vibration. The test conditions, the critical flowrates, the vibration frequencies, and the locations of the tubes most susceptible to vibration are presented. The given data are used for a comparison with a presently recognized method of vibration prediction and will permit updated evaluations as more advanced methods become available in the future.

  15. Investigation of the passivity, hydrogen embrittlement and threshold stress of duplex stainless steel

    SciTech Connect (OSTI)

    Gojic, M.; Metikos-Hukovic, M.; Babic, R. [Univ. of Zagreb (Croatia)

    1996-12-31T23:59:59.000Z

    The electrochemical behavior of duplex stainless steel has been studied in various environments. Its passivity state was investigated in borate-buffer using cyclic voltammetry and impedance spectroscopy techniques. The susceptibility towards sulfide stress cracking and hydrogen embrittlement were tested at a constant load under cathodic polarization in the NACE solution saturated with H{sub 2}S and 0.5 M sulfuric acid solution containing As{sub 2}O{sub 3} as a promoter. SEM analysis accompanied these investigations. It is proposed that the highly protective quality of the passive film formed on the investigated duplex stainless steel may be associated with the presence of multiple oxidation rates (Cr{sup 3+} and Cr{sup 6+}) formed in the solid state along with (CrO{sub 4}{sup 2{minus}} and MoO{sub 4}{sup 2{minus}}) anions and the great variety of possible bridging ligand states (OH{sup {minus}}, H{sub 2}O, O{sup 2{minus}}). This leads to a significant degree of bonding flexibility and supports amorphous, i.e., glassy structure of the passive film. Therefore, the stresses that would be associated with epitaxy, are easily alleviated without the creation of long-range defect structures. The investigated duplex stainless steel shows high resistance to hydrogen embrittlement and sulfide stress cracking. The embrittlement index was determined to be 26%, while the threshold stress amounts to 84% of the yield strength.

  16. No-Impact Threshold Values for NRAP’s Reduced Order Models

    SciTech Connect (OSTI)

    Last, George V.; Murray, Christopher J.; Brown, Christopher F.; Jordan, Preston D.; Sharma, Maneesh

    2013-02-01T23:59:59.000Z

    The purpose of this study was to develop methodologies for establishing baseline datasets and statistical protocols for determining statistically significant changes between background concentrations and predicted concentrations that would be used to represent a contamination plume in the Gen II models being developed by NRAP’s Groundwater Protection team. The initial effort examined selected portions of two aquifer systems; the urban shallow-unconfined aquifer system of the Edwards-Trinity Aquifer System (being used to develop the ROM for carbon-rock aquifers, and the a portion of the High Plains Aquifer (an unconsolidated and semi-consolidated sand and gravel aquifer, being used to development the ROM for sandstone aquifers). Threshold values were determined for Cd, Pb, As, pH, and TDS that could be used to identify contamination due to predicted impacts from carbon sequestration storage reservoirs, based on recommendations found in the EPA’s “Unified Guidance for Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities” (US Environmental Protection Agency 2009). Results from this effort can be used to inform a “no change” scenario with respect to groundwater impacts, rather than the use of an MCL that could be significantly higher than existing concentrations in the aquifer.

  17. Study of the near-threshold ? ? mass enhancement in doubly OZI-suppressed J / ? ? ? ? ? decays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ablikim, M.; Achasov, M. N.; Albayrak, O.; Ambrose, D. J.; An, F. F.; An, Q.; Bai, J. Z.; Ban, Y.; Becker, J.; Bennett, J. V.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; Ding, W. M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Fava, L.; Feng, C. Q.; Ferroli, R. B.; Friedel, P.; Fu, C. D.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, T.; Guo, Y. P.; Han, Y. L.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, G. M.; Huang, G. S.; Huang, J. S.; Huang, L.; Huang, X. T.; Huang, Y.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kopf, B.; Kornicer, M.; Kuehn, W.; Lai, W.; Lange, J. S.; Leyhe, M.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, Q. J.; Li, S. L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Lin, D.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K. Y.; Liu, Kai; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nicholson, C.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Park, J. W.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Prencipe, E.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schaefer, B. D.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Toth, D.; Ullrich, M.; Varner, G. S.; Wang, B. Q.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q. J.; Wang, S. G.; Wang, X. F.; Wang, X. L.; Wang, Y. F.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, Q. G.; Wen, S. P.; Werner, M.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, S. X.; Wu, W.; Wu, Z.; Xia, L. G.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Xu, Z. R.; Xue, F.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yu, S. P.; Yuan, C. Z.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, R.; Zhang, S. H.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhang, Zhenghao; Zhao, G.; Zhao, H. S.; Zhao, J. W.; Zhao, K. X.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. Z.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zhong, B.; Zhong, Z.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. M.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.

    2013-02-01T23:59:59.000Z

    A 2.25×10? J/? event sample accumulated with the BESIII detector is used to study the doubly Okubo-Zweig-Iizuka-suppressed decay modes J/?????, ????????, ??K?K?. A strong deviation (>30?) from three-body J/????? phase space is observed near the ?? mass threshold that is consistent with a previous observation reported by the BESII experiment. A partial wave analysis with a tensor covariant amplitude that assumes that the enhancement is due to the presence of a resonance, the X(1810), is performed and confirms that the spin-parity of the X(1810) is 0??. The mass and width of the X(1810) are determined to be M=1795±7(stat)+13-5(syst)±19(mod) MeV/c² and ?=95±10(stat)+21-34(syst)±75(mod) MeV/c², respectively, and the product branching fraction is measured to be B(J/???X(1810))×B(X(1810)???)=(2.00±0.08(stat)+0.45-1.00(syst)±1.30(mod))×10??. These results are consistent within errors with those of the BESII experiment.

  18. Study of a Threshold Cherenkov Counter Based on Silica Aerogels with Low Refractive Indices

    E-Print Network [OSTI]

    I. Adachi et al

    1994-12-13T23:59:59.000Z

    To identify $\\pi^{\\pm}$ and $K^{\\pm}$ in the region of $1.0\\sim 2.5$ GeV/c, a threshold Cherenkov counter equipped with silica aerogels has been investigated. Silica aerogels with a low refractive index of 1.013 have been successfully produced using a new technique. By making use of these aerogels as radiators, we have constructed a Cherenkov counter and have checked its properties in a test beam. The obtained results have demonstrated that our aerogel was transparent enough to make up for loss of the Cherenkov photon yield due to a low refractive index. Various configurations for the photon collection system and some types of photomultipliers, such as the fine-mesh type, for a read out were also tested. From these studies, our design of a Cherenkov counter dedicated to $\\pi / K$ separation up to a few GeV/c %in the momentum range of $1.0 \\sim 2.5$ GeV/c with an efficiency greater than $90$ \\% was considered.

  19. Maximum approximate entropy and r threshold: A new approach for regularity changes detection

    E-Print Network [OSTI]

    Juan F. Restrepo; Gastón Schlotthauer; María E. Torres

    2014-05-29T23:59:59.000Z

    Approximate entropy (ApEn) has been widely used as an estimator of regularity in many scientific fields. It has proved to be a useful tool because of its ability to distinguish different system's dynamics when there is only available short-length noisy data. Incorrect parameter selection (embedding dimension $m$, threshold $r$ and data length $N$) and the presence of noise in the signal can undermine the ApEn discrimination capacity. In this work we show that $r_{max}$ ($ApEn(m,r_{max},N)=ApEn_{max}$) can also be used as a feature to discern between dynamics. Moreover, the combined use of $ApEn_{max}$ and $r_{max}$ allows a better discrimination capacity to be accomplished, even in the presence of noise. We conducted our studies using real physiological time series and simulated signals corresponding to both low- and high-dimensional systems. When $ApEn_{max}$ is incapable of discerning between different dynamics because of the noise presence, our results suggest that $r_{max}$ provides additional information that can be useful for classification purposes. Based on cross-validation tests, we conclude that, for short length noisy signals, the joint use of $ApEn_{max}$ and $r_{max}$ can significantly decrease the misclassification rate of a linear classifier in comparison with their isolated use.

  20. Energetics and structural properties of three-dimensional bosonic clusters near threshold

    SciTech Connect (OSTI)

    Hanna, G. J.; Blume, D. [Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States)

    2006-12-15T23:59:59.000Z

    We treat three-dimensional bosonic clusters with up to N=40 atoms, interacting additively through two-body van der Waals potentials, in the near-threshold regime. Our study includes super-borromean systems with N atoms for which all subsystems are unbound. We determine the energetics and structural properties such as the expectation value of the interparticle distance as a function of the coupling strength. It has been shown that the coupling strength g{sub *}{sup (N)}, for which the N-body system becomes unbound, is bounded by the coupling constant g{sub *}{sup (N-1)}, for which the next smaller system with N-1 atoms becomes unbound, i.e., g{sub *}{sup (N)}{>=}(N-1)g{sub *}{sup (N-1)}/N. By fitting our numerically determined ground-state energies to a simple functional form with three fitting parameters, we determine the relationship between g{sub *}{sup (N)} and g{sub *}{sup (N-1)}. Our trimer and tetramer energies fall on the so-called Tjon line, which has been studied in nuclear physics. We confirm the existence of generalized Tjon lines for larger clusters. Signatures of the universal behavior of weakly bound three-dimensional clusters can possibly be observed in ultracold Bose gases.

  1. On the Eddington limit in accretion discs

    E-Print Network [OSTI]

    D. Heinzeller; W. J. Duschl

    2006-10-25T23:59:59.000Z

    Although the Eddington limit has originally been derived for stars, recently its relevance for the evolution of accretion discs has been realized. We discuss the question whether the classical Eddington limit - which has been applied globally for almost all calculations on accretion discs - is a good approximation if applied locally in the disc. For this purpose, a critical accretion rate corresponding to this type of modified classical Eddington limit is calculated from thin alpha-disc models and slim disc models. We account for the non-spherical symmetry of the disc models by computing the local upper limits on the accretion rate from vertical and radial force equilibria separately. It is shown that the results can differ considerably from the classical (global) value: The vertical radiation force limits the maximum accretion rate in the inner disc region to much less than the classical Eddington value in thin alpha-discs, while it allows for significantly higher accretion rates in slim discs. We discuss the implications of these results for the evolution of accretion discs and their central objects.

  2. Constructing Amplitudes from Their Soft Limits

    SciTech Connect (OSTI)

    Boucher-Veronneau, Camille; Larkoski, Andrew J.; /SLAC

    2011-12-09T23:59:59.000Z

    The existence of universal soft limits for gauge-theory and gravity amplitudes has been known for a long time. The properties of the soft limits have been exploited in numerous ways; in particular for relating an n-point amplitude to an (n-1)-point amplitude by removing a soft particle. Recently, a procedure called inverse soft was developed by which 'soft' particles can be systematically added to an amplitude to construct a higher-point amplitude for generic kinematics. We review this procedure and relate it to Britto-Cachazo-Feng-Witten recursion. We show that all tree-level amplitudes in gauge theory and gravity up through seven points can be constructed in this way, as well as certain classes of NMHV gauge-theory amplitudes with any number of external legs. This provides us with a systematic procedure for constructing amplitudes solely from their soft limits.

  3. THRESHOLD PROBABILITY FUNCTIONS AND THERMAL INHOMOGENEITIES IN THE Ly{alpha} FOREST

    SciTech Connect (OSTI)

    Lee, Khee-Gan; Spergel, David N., E-mail: lee@astro.princeton.edu, E-mail: dns@astro.princeton.edu [Department of Astrophysical Science, Princeton University, Princeton, NJ 08544 (United States)

    2011-06-10T23:59:59.000Z

    We introduce to astrophysics the threshold probability functions S{sub 2}, C{sub 2}, and D{sub 2} first derived by Torquato et al., which effectively samples the flux probability distribution function (PDF) of the Ly{alpha} forest at different spatial scales. These statistics are tested on mock Ly{alpha} forest spectra based on various toy models for He II reionization, with homogeneous models with various temperature-density relations as well as models with temperature inhomogeneities. These mock samples have systematics and noise added to simulate the latest Sloan Digital Sky Survey Data Release 7 (SDSS DR7) data. We find that the flux PDF from SDSS DR7 can be used to constrain the temperature-density relation {gamma} (where T{proportional_to}(1 + {Delta}){sup {gamma}-1}) of the intergalactic medium (IGM) at z = 2.5 to a precision of {Delta}{gamma} = 0.2 at {approx}4{sigma} confidence. The flux PDF is degenerate to temperature inhomogeneities in the IGM arising from He II reionization, but we find S{sub 2} can detect these inhomogeneities at {approx}3{sigma}, with the assumption that the flux continuum of the Ly{alpha} forest can be determined to 9% accuracy, approximately the error from current fitting methods. If the flux continuum can be determined to 3% accuracy, then S{sub 2} is capable of constraining the characteristic scale of temperature inhomogeneities, with {approx}4{sigma} differentiation between toy models with hot bubble radii of 50 h{sup -1} Mpc and 25 h{sup -1} Mpc.

  4. Lead-chalcogenide mid-infrared vertical external cavity surface emitting lasers with improved threshold: Theory and experiment

    SciTech Connect (OSTI)

    Fill, Matthias [ETH Zurich, Laser Spectroscopy and Sensing Lab, 8093 Zurich (Switzerland) [ETH Zurich, Laser Spectroscopy and Sensing Lab, 8093 Zurich (Switzerland); Phocone AG, 8005 Zurich (Switzerland)] [Switzerland; Debernardi, Pierluigi [IEIIT-CNR, Torino 10129 (Italy)] [IEIIT-CNR, Torino 10129 (Italy); Felder, Ferdinand [Phocone AG, 8005 Zurich (Switzerland)] [Phocone AG, 8005 Zurich (Switzerland); Zogg, Hans [ETH Zurich (Switzerland)] [ETH Zurich (Switzerland)

    2013-11-11T23:59:59.000Z

    Mid-infrared Vertical External Cavity Surface Emitting Lasers (VECSEL) based on narrow gap lead-chalcogenide (IV-VI) semiconductors exhibit strongly reduced threshold powers if the active layers are structured laterally for improved optical confinement. This is predicted by 3-d optical calculations; they show that lateral optical confinement is needed to counteract the anti-guiding features of IV-VIs due to their negative temperature dependence of the refractive index. An experimental proof is performed with PbSe quantum well based VECSEL grown on a Si-substrate by molecular beam epitaxy and emitting around 3.3??m. With proper mesa-etching, the threshold intensity is about 8-times reduced.

  5. The limited validity of the Kubo formula

    E-Print Network [OSTI]

    Steinhoff, Heinz-Jürgen

    The limited validity of the Kubo formula for thermal conduction J. Gemmer, UniversitË?at Osnabr; Transport phenomena and Kubo formula Normal transport phenomena: ``field driven'' j = L F F electric current (#) F = -#V Kubo formula (KF): L F (#) = 1 V # # 0 dt e -i#t # # 0 d# Tr{â??# 0 â?? j(0) â?? j(t + i

  6. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    SciTech Connect (OSTI)

    NA

    2004-11-22T23:59:59.000Z

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  7. Flexible moldable conductive current-limiting materials

    SciTech Connect (OSTI)

    Shea, John Joseph (Pittsburgh, PA); Djordjevic, Miomir B. (Milwaukee, WI); Hanna, William Kingston (Pittsburgh, PA)

    2002-01-01T23:59:59.000Z

    A current limiting PTC device (10) has two electrodes (14) with a thin film of electric conducting polymer material (20) disposed between the electrodes, the polymer material (20) having superior flexibility and short circuit performance, where the polymer material contains short chain aliphatic diepoxide, conductive filler particles, curing agent, and, preferably, a minor amount of bisphenol A epoxy resin.

  8. IRS Contribution Limits and OSU Retirement Programs

    E-Print Network [OSTI]

    Veiga, Pedro Manuel Barbosa

    Impact: OTRS requires contributions on total compensation (salary plus benefits) without regardIRS Contribution Limits and OSU Retirement Programs The OSU Defined Contribution Plan (DCP), (for Revenue Code 401(a). The Internal Revenue Code restrictions on employer-paid contributions make

  9. Extending the Upper Temperature Limit for Life

    E-Print Network [OSTI]

    Lovley, Derek

    ) un- der N2-CO2 (80:20) in sealed culture tubes that con- tained formate (10 mM) as the electron donor that permit strain 121 to grow at such high temperatures are unknown. It is gen- erally assumed that the upperExtending the Upper Temperature Limit for Life Kazem Kashefi and Derek R. Lovley* The upper

  10. Physical limits of Communication Madhu Sudan1

    E-Print Network [OSTI]

    Sudan, Madhu

    Physical limits of Communication Madhu Sudan1 1 Microsoft Research New England, One Memorial Drive by a particle may flip during transmission, and delay, where the particle's arrival time at a © Madhu Sudan, Germany #12;Madhu Sudan 5 destination may not correspond exactly to its departure time. In particular we

  11. Physical Limitations on Mining Natural Earth Systems

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    Physical Limitations on Mining Natural Earth Systems A view of the Himalayas from Lhasa Tad Patzek of fossil fuels ("resources") left all over the Earth The resource size (current balance of a banking flow-based solutions (wind turbines, photovoltaics, and biofuels) will require most radical changes

  12. Half-life Limit of 19Mg

    E-Print Network [OSTI]

    N. Frank; T. Baumann; D. Bazin; R. R. C. Clement; M. W. Cooper; P. Heckman; W. A. Peters; A. Stolz; M. Thoennessen; M. S. Wallace

    2003-10-17T23:59:59.000Z

    A search for 19Mg was performed using projectile fragmentation of a 150 MeV/nucleon 36Ar beam. No events of 19Mg were observed. From the time-of-flight through the fragment separator an upper limit of 22 ns for the half-life of 19Mg was established.

  13. Economic Growth, Physical Limits and Liveability

    E-Print Network [OSTI]

    on criteria air contaminants, water use, land use, greenhouse gas emissions and solid waste disposal and population growth, impose the physical limits and then simulate household and firm responses to policy and assess the resulting implications for liveability in the region. I measure liveability using 24

  14. $J/?$ production in Au+Au/Cu+Cu collisions at $\\sqrt{s}_{NN}$=200 GeV and the threshold model

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2006-10-09T23:59:59.000Z

    Using the QGP motivated threshold model, where all the $J/\\psi$'s are suppressed above a threshold density, we have analyzed the preliminary PHENIX data on the centrality dependence of nuclear modification factor for $J/\\psi$'s in Cu+Cu and in Au+Au collisions, at RHIC energy, $\\sqrt{s}_{NN}$=200 GeV. Centrality dependence of $J/\\psi$ suppression in Au+Au collisions are well explained in the model for threshold densities in ranges of 3.6-3.7 $fm^{-2}$. $J/\\psi$ suppression in Cu+Cu collisions on the other hand are not explained in the model.

  15. How energy conservation limits our measurements

    E-Print Network [OSTI]

    Miguel Navascues; Sandu Popescu

    2014-04-25T23:59:59.000Z

    Observations in Quantum Mechanics are subject to complex restrictions arising from the principle of energy conservation. Determining such restrictions, however, has been so far an elusive task, and only partial results are known. In this paper we discuss how constraints on the energy spectrum of a measurement device translate into limitations on the measurements which we can effect on a target system with non-trivial energy operator. We provide efficient algorithms to characterize such limitations and we quantify them exactly when the target is a two-level quantum system. Our work thus identifies the boundaries between what is possible or impossible to measure, i.e., between what we can see or not, when energy conservation is at stake.

  16. Flow reversal power limit for the HFBR

    SciTech Connect (OSTI)

    Cheng, Lap Y.; Tichler, P.R.

    1995-10-01T23:59:59.000Z

    The High Flux Beam Reactor (HFBR) undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Uncertainties about the afterheat removal capability during the flow reversal has limited the reactor operating power to 30 MW. An experimental and analytical program to address these uncertainties is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW.

  17. Polymer Quantum Mechanics and its Continuum Limit

    E-Print Network [OSTI]

    Alejandro Corichi; Tatjana Vukasinac; Jose A. Zapata

    2007-08-22T23:59:59.000Z

    A rather non-standard quantum representation of the canonical commutation relations of quantum mechanics systems, known as the polymer representation has gained some attention in recent years, due to its possible relation with Planck scale physics. In particular, this approach has been followed in a symmetric sector of loop quantum gravity known as loop quantum cosmology. Here we explore different aspects of the relation between the ordinary Schroedinger theory and the polymer description. The paper has two parts. In the first one, we derive the polymer quantum mechanics starting from the ordinary Schroedinger theory and show that the polymer description arises as an appropriate limit. In the second part we consider the continuum limit of this theory, namely, the reverse process in which one starts from the discrete theory and tries to recover back the ordinary Schroedinger quantum mechanics. We consider several examples of interest, including the harmonic oscillator, the free particle and a simple cosmological model.

  18. Diffusion limited reactions in confined environments

    E-Print Network [OSTI]

    Jeremy D. Schmit; Ercan Kamber; Jané Kondev

    2007-11-19T23:59:59.000Z

    We study the effect of confinement on diffusion limited bimolecular reactions within a lattice model where a small number of reactants diffuse amongst a much larger number of inert particles. When the number of inert particles is held constant the rate of the reaction is slow for small reaction volumes due to limited mobility from crowding, and for large reaction volumes due to the reduced concentration of the reactants. The reaction rate proceeds fastest at an intermediate confinement corresponding to volume fraction near 1/2 and 1/3 in two and three dimensions, respectively. We generalize the model to off-lattice systems with hydrodynamic coupling and predict that the optimal reaction rate for monodisperse colloidal systems occurs when the volume fraction is ~0.18. Finally, we discuss the application of our model to bimolecular reactions inside cells as well as the dynamics of confined polymers.

  19. Mass and temperature limits for blackbody radiation

    E-Print Network [OSTI]

    Alessandro Pesci

    2006-03-24T23:59:59.000Z

    A spherically symmetric distribution of classical blackbody radiation is considered, at conditions in which gravitational self-interaction effects become not negligible. Static solutions to Einstein field equations are searched for, for each choice of the assumed central energy density. Spherical cavities at thermodynamic equilibrium, i.e. filled with blackbody radiation, are then studied, in particular for what concerns the relation among the mass M of the ball of radiation contained in them and their temperature at center and at the boundary. For these cavities it is shown, in particular, that: i) there is no absolute limit to M as well to their central and boundary temperatures; ii) when radius R is fixed, however, limits exist both for mass and for boundary energy density rho_B: M temperature) of the ball of radiation.

  20. Toxicity Data to Determine Refrigerant Concentration Limits

    SciTech Connect (OSTI)

    Calm, James M.

    2000-09-30T23:59:59.000Z

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  1. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    SciTech Connect (OSTI)

    P. Bernot

    2005-07-13T23:59:59.000Z

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  2. Probabilistic Turing Machine and Landauer Limit

    E-Print Network [OSTI]

    Marco Frasca

    2012-06-04T23:59:59.000Z

    We show the equivalence between a probabilistic Turing machine and the time evolution of a one-dimensional Ising model, the Glauber model in one dimension, equilibrium positions representing the results of computations of the Turing machine. This equivalence permits to map a physical system on a computational system providing in this way an evaluation of the entropy at the end of computation. The result agrees with Landauer limit.

  3. Probabilistic Turing Machine and Landauer Limit

    E-Print Network [OSTI]

    Frasca, Marco

    2012-01-01T23:59:59.000Z

    We show the equivalence between a probabilistic Turing machine and the time evolution of a one-dimensional Ising model, the Glauber model in one dimension, equilibrium positions representing the results of computations of the Turing machine. This equivalence permits to map a physical system on a computational system providing in this way an evaluation of the entropy at the end of computation. The result agrees with Landauer limit.

  4. Association between occupational exposure to arsenic and neurological, respiratory and renal effects

    SciTech Connect (OSTI)

    Halatek, Tadeusz [Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Lodz (Poland)], E-mail: halatek@imp.lodz.pl; Sinczuk-Walczak, Halina [Outpatient Clinic of Occupational Disease, Nofer Institute of Occupational Medicine, Lodz (Poland); Rabieh, Sasan [Faculty of Biology, Chemistry, and Geosciences, University of Bayreuth, Bayreuth (Germany); Wasowicz, Wojciech [Department of Toxicology and Carcinogenesis, Nofer Institute of Occupational Medicine, Lodz (Poland)

    2009-09-01T23:59:59.000Z

    Occupational exposure by inhalation in copper smelter is associated with several subclinical health phenomena. The respiratory tract is usually involved in the process of detoxication of inhaled noxious agents which, as arsenic, can act as inductors of oxidative stress (Lantz, R.C., Hays, A.M., 2006. Role of oxidative stress in arsenic-induced toxicity. Drug Metab. Rev. 38, 791-804). It is also known that irritating fumes affect distal bronchioles of non-ciliated, epithelial Clara cells, which secrete anti-inflammatory and immunosuppressive Clara cell protein (CC16) into the respiratory tract. The study group comprised 39 smelters employed at different workplaces in a copper foundry, matched for age and smoking habits with the control group (n = 16). Subjective neurological symptoms (SNS), visual evoked potentials (VEP), electroneurographic (EneG) and electroencephalographic (EEG) results were examined in the workers and the relationships between As concentration in the air (As-Air) and urine (As-U) were assessed. Effects of exposure were expressed in terms of biomarkers: CC16 as early pulmonary biomarker and {beta}{sub 2}-microglobulin ({beta}{sub 2}M) in urine and serum and retinol binding protein (RBP) as renal markers, measured by sensitive latex immunoassay. The concentrations of arsenic exceeded about two times the Threshold Limit Values (TLV) (0.01 mg/m{sup 3}). The contents of lead did not exceed the TLV (0.05 mg/m{sup 3}). Low CC16 levels in serum (12.1 {mu}g/l) of workers with SNS and VEP symptoms and highest level As-U (x{sub a} 39.0 {mu}g/l) were noted earliest in relation to occupational time. Moreover, those effects were associated with increased levels of urinary and serum {beta}{sub 2}M and urinary RBP. Results of our study suggested the initiative key role of oxidative stress in triggering the processes that eventually lead to the subclinical effects of arsenic on the nervous system.

  5. Ideal Quantum Gases with Planck Scale Limitations

    E-Print Network [OSTI]

    Rainer Collier

    2015-03-14T23:59:59.000Z

    A thermodynamic system of non-interacting quantum particles changes its statistical distribution formulas if there is a universal limitation for the size of energetic quantum leaps (magnitude of quantum leaps smaller than Planck energy). By means of a restriction of the a priori equiprobability postulate one can reach a thermodynamic foundation of these corrected distribution formulas. The number of microstates is determined by means of a suitable counting method and combined with thermodynamics via the Boltzmann principle. The result is that, for particle energies that come close to the Planck energy, the thermodynamic difference between fermion and boson distribution vanishes. Both distributions then approximate a Boltzmann distribution. The wave and particle character of the quantum particles, too, can be influenced by choosing the size of the temperature and particle energy parameters relative to the Planck energy, as you can see from the associated fluctuation formulas. In the case of non-relativistic degeneration, the critical parameters Fermi momentum (fermions) and Einstein temperature (bosons) vanish as soon as the rest energy of the quantum particles reaches the Planck energy. For the Bose-Einstein condensation there exists, in the condensation range, a finite upper limit for the number of particles in the ground state, which is determined by the ratio of Planck mass to the rest mass of the quantum particles. In the relativistic high-temperature range, the energy densities of photon and neutrino radiation have finite limit values, which is of interest with regard to the start of cosmic expansion.

  6. Assessing Possibilities & Limits for Solar Cells

    E-Print Network [OSTI]

    Nayak, Pabitra K; Cahen, David

    2011-01-01T23:59:59.000Z

    What are the solar cell efficiencies that we can strive towards? We show here that several simple criteria, based on cell and module performance data, serve to evaluate and compare all types of today's solar cells. Analyzing these data allows to gauge in how far significant progress can be expected for the various cell types and, most importantly from both the science and technology points of view, if basic bounds, beyond those known today, may exist, that can limit such progress. This is important, because half a century after Shockley and Queisser (SQ) presented limits, based on detailed balance calculations for single absorber solar cells, those are still held to be the only ones, we need to consider; most efforts to go beyond SQ are directed towards attempts to circumvent them, primarily via smart optics, or optoelectronics. After formulating the criteria and analyzing known loss mechanisms, use of such criteria suggests - additional limits for newer types of cells, Organic and Dye-Sensitized ones, and th...

  7. Means for limiting and ameliorating electrode shorting

    DOE Patents [OSTI]

    Van Konynenburg, Richard A. (Livermore, CA); Farmer, Joseph C. (Tracy, CA)

    1999-01-01T23:59:59.000Z

    A fuse and filter arrangement for limiting and ameliorating electrode shorting in capacitive deionization water purification systems utilizing carbon aerogel, for example. This arrangement limits and ameliorates the effects of conducting particles or debonded carbon aerogel in shorting the electrodes of a system such as a capacitive deionization water purification system. This is important because of the small interelectrode spacing and the finite possibility of debonding or fragmentation of carbon aerogel in a large system. The fuse and filter arrangement electrically protect the entire system from shutting down if a single pair of electrodes is shorted and mechanically prevents a conducting particle from migrating through the electrode stack, shorting a series of electrode pairs in sequence. It also limits the amount of energy released in a shorting event. The arrangement consists of a set of circuit breakers or fuses with one fuse or breaker in the power line connected to one electrode of each electrode pair and a set of screens of filters in the water flow channels between each set of electrode pairs.

  8. Means for limiting and ameliorating electrode shorting

    SciTech Connect (OSTI)

    Konynenburg, R.A. van; Farmer, J.C.

    1999-11-09T23:59:59.000Z

    A fuse and filter arrangement is described for limiting and ameliorating electrode shorting in capacitive deionization water purification systems utilizing carbon aerogel, for example. This arrangement limits and ameliorates the effects of conducting particles or debonded carbon aerogel in shorting the electrodes of a system such as a capacitive deionization water purification system. This is important because of the small interelectrode spacing and the finite possibility of debonding or fragmentation of carbon aerogel in a large system. The fuse and filter arrangement electrically protect the entire system from shutting down if a single pair of electrodes is shorted and mechanically prevents a conducting particle from migrating through the electrode stack, shorting a series of electrode pairs in sequence. It also limits the amount of energy released in a shorting event. The arrangement consists of a set of circuit breakers or fuses with one fuse or breaker in the power line connected to one electrode of each electrode pair and a set of screens of filters in the water flow channels between each set of electrode pairs.

  9. Limitations and improvements for harmonic generation measurements

    SciTech Connect (OSTI)

    Best, Steven; Croxford, Anthony; Neild, Simon [Department of Mechanical Engineering, Queens Building, University Walk, Bristol BS8 1TR (United Kingdom)

    2014-02-18T23:59:59.000Z

    A typical acoustic harmonic generation measurement comes with certain limitations. Firstly, the use of the plane wave-based analysis used to extract the nonlinear parameter, ?, ignores the effects of diffraction, attenuation and receiver averaging which are common to most experiments, and may therefore limit the accuracy of a measurement. Secondly, the method usually requires data obtained from a through-transmission type setup, which may not be practical in a field measurement scenario where access to the component is limited. Thirdly, the technique lacks a means of pinpointing areas of damage in a component, as the measured nonlinearity represents an average over the length of signal propagation. Here we describe a three-dimensional model of harmonic generation in a sound beam, which is intended to provide a more realistic representation of a typical experiment. The presence of a reflecting boundary is then incorporated into the model to assess the feasibility of performing single-sided measurements. Experimental validation is provided where possible. Finally, a focusing acoustic source is modelled to provide a theoretical indication of the afforded advantages when the nonlinearity is localized.

  10. Observed physical processes in mechanical tests of PBX9501 and recomendations for experiments to explore a possible plasticity/damage threshold

    SciTech Connect (OSTI)

    Buechler, Miles A. [Los Alamos National Laboratory

    2012-05-02T23:59:59.000Z

    This memo discusses observations that have been made in regards to a series of monotonic and cyclic uniaxial experiments performed on PBX9501 by Darla Thompson under Enhanced Surveilance Campaign support. These observations discussed in Section Cyclic compression observations strongly suggest the presence of viscoelastic, plastic, and damage phenomena in the mechanical response of the material. In Secton Uniaxial data analysis and observations methods are discussed for separating out the viscoelastic effects. A crude application of those methods suggests the possibility of a critical stress below which plasticity and damage may be negligible. The threshold should be explored because if it exists it will be an important feature of any constitutive model. Additionally, if the threshold exists then modifications of experimental methods may be feasible which could potentially simplify future experiments or provide higher quality data from those experiments. A set of experiments to explore the threshold stress are proposed in Section Exploratory tests program for identifying threshold stress.

  11. 216 J. Opt. Soc. Am. B/Vol. 13, No. 1/January 1996 D. von der Linde and H. Schuler Breakdown threshold and plasma formation

    E-Print Network [OSTI]

    von der Linde, D.

    216 J. Opt. Soc. Am. B/Vol. 13, No. 1/January 1996 D. von der Linde and H. Sch¨uler Breakdown threshold and plasma formation in femtosecond laser­solid interaction D. von der Linde and H. Sch

  12. SupplementalFigures1 Supplementary Figure S1: Sample Mean Excess (SME) for a range of thresholds at the grid point closest to 3

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    SupplementalFigures1 2 Supplementary Figure S1: Sample Mean Excess (SME) for a range of thresholds at the grid point closest to 3 Bergen, Norway in the BCMHIRHAM5 downscaling. The SME

  13. Ultralow-threshold graded-index separate-confinement single quantum well buried heterostructure (Al,Ga)As lasers with high reflectivity coatings

    SciTech Connect (OSTI)

    Derry, P.L.; Yariv, A.; Lau, K.Y.; Bar-Chaim, N.; Lee, K.; Rosenberg, J.

    1987-06-22T23:59:59.000Z

    Unlike conventional semiconductor lasers, single quantum well lasers with high reflectively coatings have dramatically reduced threshold currents as a result of the smaller volume of the (active) quantum well region. A cw threshold current of 0.95 mA was obtained for a buried graded-index separate-confinement heterostructure single quantum well laser with facet reflectivities of --70%, a cavity length of 250 ..mu..m, and an active region stripe width of 1 ..mu..m.

  14. Karnataka Power Corporation Limited and National Thermal Power...

    Open Energy Info (EERE)

    Limited and National Thermal Power Corporation JV Jump to: navigation, search Name: Karnataka Power Corporation Limited and National Thermal Power Corporation JV Place: India...

  15. Polymer Electrolyte Fuel Cell Lifetime Limitations: The Role...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation Polymer Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation...

  16. (Expired) Nationwide Limited Public Interest Waiver for LED Lighting...

    Energy Savers [EERE]

    (Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC Units: February 11, 2010 (Expired) Nationwide Limited Public Interest Waiver for LED Lighting and HVAC...

  17. Thickness dependent self limiting 1-D tin oxide nanowire arrays...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    dependent self limiting 1-D tin oxide nanowire arrays by nanosecond pulsed laser irradiation. Thickness dependent self limiting 1-D tin oxide nanowire arrays by nanosecond pulsed...

  18. Limiter H-mode experiments on TFTR

    SciTech Connect (OSTI)

    Bush, C.E. (Oak Ridge National Lab., TN (USA)); Bretz, N.L.; Fredrickson, E.D.; McGuire, K.M.; Nazikian, R.; Park, H.K.; Schivell, J.; Taylor, G.; Bitter, M.; Budny, R.; Cohen, S.A.; Kilpatrick, S.J.; LeBlanc, B.; Manos, D.M.; Meade, D.; Paul, S.F.; Scott, S.D.; Stratton, B.C.; Synakowski, E.J.; Towner, H.H.; Wieland, R.M.; Arunasalam, V.; Bateman, G.; Bell, M.G.; Bell, R.; Boivin, R.; Cavallo, A.; Cheng, C.Z.; Chu, T.K.; Co

    1991-05-01T23:59:59.000Z

    Limiter H-modes with centrally peaked density profiles have been obtained in TFTR using a highly conditioned graphite limiter. The transition to these centrally peaked H-modes takes place from the supershot to the H-mode rather than the usual L- to H-mode transition observed on other tokamaks. Bidirectional beam heating is required to induce the transition. Density peaking factors, n{sub e}(0)/, greater than 2.3 are obtained and at the same time the H-mode characteristics are similar to those of limiter H-modes on other tokamaks, while the global confinement, {tau}{sub E}, can be >2.5 times L-mode scaling. The transport analysis of the data shows that transport in these H-modes is similar to that of supershots within the inner 0.6 m core of the plasma, but the stored electron energy (calculated using measured values of T{sub e} and n{sub e}) is higher for the H-mode at the plasma edge. Microwave scattering data for the edge plasma shows broad spectra at k = 5.5 cm{sup {minus}1} which begin at the drop in D{sub {alpha}} radiation and are strongly shifted in the electron diamagnetic drift direction. At the same time, beam emission spectroscopy (BES) shows a coherent mode near the boundary which propagates in the ion direction with m = 15--20 at 20--30 kHz. During the ELM event these apparent rotations cease and Mirnov fluctuations in the frequency range of 50--500 kHz increase in intensity. 16 refs., 8 figs.

  19. A continuum model with a percolation threshold and tunneling-assisted interfacial conductivity for carbon nanotube-based nanocomposites

    SciTech Connect (OSTI)

    Wang, Yang; Weng, George J., E-mail: weng@jove.rutgers.edu [Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, New Jersey 08903 (United States); Meguid, Shaker A. [Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8 (Canada); Hamouda, Abdel Magid [Department of Mechanical and Industrial Engineering, Qatar University, Doha (Qatar)

    2014-05-21T23:59:59.000Z

    A continuum model that possesses several desirable features of the electrical conduction process in carbon-nanotube (CNT) based nanocomposites is developed. Three basic elements are included: (i) percolation threshold, (ii) interface effects, and (iii) tunneling-assisted interfacial conductivity. We approach the first one through the selection of an effective medium theory. We approach the second one by the introduction of a diminishing layer of interface with an interfacial conductivity to build a 'thinly coated' CNT. The third one is introduced through the observation that interface conductivity can be enhanced by electron tunneling which in turn can be facilitated with the formation of CNT networks. We treat this last issue in a continuum fashion by taking the network formation as a statistical process that can be represented by Cauchy's probability density function. The outcome is a simple and yet widely useful model that can simultaneously capture all these fundamental characteristics. It is demonstrated that, without considering the interface effect, the predicted conductivity would be too high, and that, without accounting for the additional contribution from the tunneling-assisted interfacial conductivity, the predicted conductivity beyond the percolation threshold would be too low. It is with the consideration of all three elements that the theory can fully account for the experimentally measured data. We further use the developed model to demonstrate that, despite the anisotropy of the intrinsic CNT conductivity, it is its axial component along the CNT direction that dominates the overall conductivity. This theory is also proved that, even with a totally insulating matrix, it is still capable of delivering non-zero conductivity beyond the percolation threshold.

  20. Dependence of the L- to H-mode Power Threshold on Toroidal Rotation and the Link to Edge Turbulence Dynamics

    SciTech Connect (OSTI)

    McKee, G; Gohil, P; Schlossberg, D; Boedo, J; Burrell, K; deGrassie, J; Groebner, R; Makowski, M; Moyer, R; Petty, C; Rhodes, T; Schmitz, L; Shafer, M; Solomon, W; Umansky, M; Wang, G; White, A; Xu, X

    2008-10-13T23:59:59.000Z

    The injected power required to induce a transition from L-mode to H-mode plasmas is found to depend strongly on the injected neutral beam torque and consequent plasma toroidal rotation. Edge turbulence and flows, measured near the outboard midplane of the plasma (0.85 < r/a < 1.0) on DIII-D with the high-sensitivity 2D beam emission spectroscopy (BES) system, likewise vary with rotation and suggest a causative connection. The L-H power threshold in plasmas with the ion {del}B drift away from the X-point decreases from 4-6 MW with co-current beam injection, to 2-3 MW with near zero net injected torque, and to <2 MW with counter injection. Plasmas with the ion {del}B drift towards the X-point exhibit a qualitatively similar though less pronounced power threshold dependence on rotation. 2D edge turbulence measurements with BES show an increasing poloidal flow shear as the L-H transition is approached in all conditions. At low rotation, the poloidal flow of turbulent eddies near the edge reverses prior to the L-H transition, generating a significant poloidal flow shear that exceeds the measured turbulence decorrelation rate. This increased poloidal turbulence velocity shear may facilitate the L-H transition. No such reversal is observed in high rotation plasmas. The poloidal turbulence velocity spectrum exhibits a transition from a Geodesic Acoustic Mode zonal flow to a higher-power, lower frequency, zero-mean-frequency zonal flow as rotation varies from co-current to balanced during a torque scan at constant injected neutral beam power, perhaps also facilitating the L-H transition. This reduced power threshold at lower toroidal rotation may benefit inherently low-rotation plasmas such as ITER.

  1. Unitary limit in cross Andreev transport

    E-Print Network [OSTI]

    I. A. Sadovskyy; G. B. Lesovik; V. M. Vinokur

    2014-12-28T23:59:59.000Z

    Crossed Andreev reflection (CAR) in which Cooper pair splits into two spin- and energy entangled electrons that leave a superconductor through respective spatially separated leads is one of the most promising approaches to generating pairs of entangled electrons. However, while the conventional (local) Andreev reflection occurs with the probability of unity, the probability of CAR is significantly suppressed. Here we propose a hybrid normal metal-superconductor setup that enables achieving a unitary limit of cross Andreev transport, i.e. CAR with the probability of unity thus offering the outcome of the entangled electrons with the 100% efficiency.

  2. Torque limited drive for manual valves

    DOE Patents [OSTI]

    Elliott, Philip G. (Metropolis, IL); Underwood, Daniel E. (Paducah, KY)

    1989-01-01T23:59:59.000Z

    The present invention is directed to a torque-limiting handwheel device for preventing manual valves from being damaged due to the application of excessive torque during the opening or closing operation of the valves. Torque can only be applied when ridges in the handwheel assembly engage in channels machined in the face of the baseplate. The amount of torque required for disengagement of the ridges from the channels is determined by the force exerted by various Bellville springs and the inclination of the side faces of the channels.

  3. Radiation from charges in the continuum limit

    SciTech Connect (OSTI)

    Ianconescu, Reuven [Shenkar College of Engineering and Design, Ramat Gan 52526 (Israel)

    2013-06-15T23:59:59.000Z

    It is known that an accelerating charge radiates according to Larmor formula. On the other hand, any DC current following a curvilinear path, consists of accelerating charges, but in such case the radiated power is 0. The scope of this paper is to analyze and quantify how a system of charges goes from a radiating state to a non radiating state when the charges distribution goes to the continuum limit. Understanding this is important from the theoretical point of view and the results of this work are applicable to particle accelerator, cyclotron and other high energy devices.

  4. Transcending the Limits of Turing Computability

    E-Print Network [OSTI]

    Vadim A. Adamyan; Cristian S. Calude; Boris S. Pavlov

    2003-05-11T23:59:59.000Z

    Hypercomputation or super-Turing computation is a ``computation'' that transcends the limit imposed by Turing's model of computability. The field still faces some basic questions, technical (can we mathematically and/or physically build a hypercomputer?), cognitive (can hypercomputers realize the AI dream?), philosophical (is thinking more than computing?). The aim of this paper is to address the question: can we mathematically build a hypercomputer? We will discuss the solutions of the Infinite Merchant Problem, a decision problem equivalent to the Halting Problem, based on results obtained in \\cite{Coins,acp}. The accent will be on the new computational technique and results rather than formal proofs.

  5. New limits for neutrinoless tau decays

    E-Print Network [OSTI]

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.

    1998-05-01T23:59:59.000Z

    double beta decays, neutrino oscillations, Z!l11l22 decays, and other rare pro- cesses. In particular, there are strict limits on muon neutrino- less decays: B(m!eg),4.9310211 and B(m!eee),2.4 310212 at 90% confidence level @18#. However, lepton num- ber... particles and on the new coupling constants. The most optimistic branching fraction predictions are at the level of about 1026. Constraints on lepton flavor violation come from studies of rare and forbidden K , p, and m decays, e-m conversions, neutrinoless...

  6. Caldyne Automatics Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:EzfeedflagBiomassSustainableCSL Gas Recovery Biomass Facility80Caldyne Automatics Limited Jump

  7. Eskom Holdings Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluating A PotentialJump to:EmminolEntergyEnvisory FinancialErpuEskom Holdings Limited

  8. QuantaSol Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit with form History Facebook icon TwitterZipQingdaoEnergyQuantaSol Limited Jump to:

  9. Defining engine efficiency limits | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny:Revised Finding of No53197 This workDayton:| Department ofengine efficiency limits

  10. Perfectenergy International Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroupPerfectenergy International Limited Jump to: navigation, search Name:

  11. Nufcor International Limited Nufcor | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcor International Limited

  12. United Biofuels Private Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro IndustriesTown of Ladoga, IndianaTurtle AirshipsUnalakleet4888°,EmpresasUnisunLimited Place:

  13. Greenrock Energy Services Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluating AGeothermal/ExplorationGoods | Open EnergyGreenrock Energy Services Limited

  14. IT Power Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup | OpenHunan Runhua New EnergyIT Power Limited Jump to: navigation,

  15. ITI Energy Limited | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual SiteofEvaluatingGroup | OpenHunan Runhua New EnergyIT Power Limited Jump to:ITI Energy EDA

  16. Reconstructing the WIMP Velocity Distribution from Direct Dark Matter Detection Data with a Non-negligible Threshold Energy

    E-Print Network [OSTI]

    Shan, Chung-Lin

    2015-01-01T23:59:59.000Z

    In this paper, we investigate the modification of our expressions developed for the model-independent data analysis procedure of the reconstruction of the (time-averaged) one-dimensional velocity distribution of Galactic Weakly Interacting Massive Particles (WIMPs) with a non-negligible experimental threshold energy. Our numerical simulations show that, for a minimal reconstructable velocity of as high as O(200) km/s, our model-independent modification of the estimator for the normalization constant could provide precise reconstructed velocity distribution points to match the true WIMP velocity distribution with a <~ 10% bias.

  17. Direct Production of Tripartite Pump-Signal-Idler Entanglement in the Above-Threshold Optical Parametric Oscillator

    E-Print Network [OSTI]

    A. S. Villar; M. Martinelli; C. Fabre; P. Nussenzveig

    2006-10-09T23:59:59.000Z

    We calculate the quantum correlations existing among the three output fields (pump, signal, and idler) of a triply resonant non-degenerate Optical Parametric Oscillator operating above threshold. By applying the standard criteria [P. van Loock and A. Furusawa, Phys. Rev. A 67, 052315 (2003)], we show that strong tripartite continuous-variable entanglement is present in this well-known and simple system. Furthermore, since the entanglement is generated directly from a nonlinear process, the three entangled fields can have very different frequencies, opening the way for multicolored quantum information networks.

  18. Hadron Physics at the Charm and Bottom Thresholds and Other Novel QCD Physics Topics at the NICA Accelerator Facility

    SciTech Connect (OSTI)

    Brodsky, Stanley J.; /SLAC

    2012-06-20T23:59:59.000Z

    The NICA collider project at the Joint Institute for Nuclear Research in Dubna will have the capability of colliding protons, polarized deuterons, and nuclei at an effective nucleon-nucleon center-of mass energy in the range {radical}s{sub NN} = 4 to 11 GeV. I briefly survey a number of novel hadron physics processes which can be investigated at the NICA collider. The topics include the formation of exotic heavy quark resonances near the charm and bottom thresholds, intrinsic strangeness, charm, and bottom phenomena, hidden-color degrees of freedom in nuclei, color transparency, single-spin asymmetries, the RHIC baryon anomaly, and non-universal antishadowing.

  19. Deep sub-threshold $?^-$ production in Ar+KCl reactions at 1.76A GeV

    E-Print Network [OSTI]

    G. Agakishiev; A. Balanda; R. Bassini; D. Belver; A. V. Belyaev; A. Blanco; M. Böhmer; J. L. Boyard; P. Braun-Munzinger; P. Cabanelas; E. Castro; S. Chernenko; T. Christ; M. Destefanis; J. Díaz; F. Dohrmann; A. Dybczak; T. Eberl; L. Fabbietti; O. V. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Fröhlich; T. Galatyuk; J. A. Garzón; R. Gernhäuser; A. Gil; C. Gilardi; M. Golubeva; D. González-Díaz; F. Guber; T. Hennino; R. Holzmann; I. Iori; A. Ivashkin; M. Jurkovic; B. Kämpfer; K. Kanaki; T. Karavicheva; D. Kirschner; I. Koenig; W. Koenig; B. W. Kolb; R. Kotte; F. Krizek; R. Krücken; W. Kühn; A. Kugler; A. Kurepin; S. Lang; J. S. Lange; K. Lapidus; T. Liu; L. Lopes; M. Lorenz; L. Maier; A. Mangiarotti; J. Markert; V. Metag; B. Michalska; J. Michel; D. Mishra; E. Morinière; J. Mousa; C. Müntz; L. Naumann; J. Otwinowski; Y. C. Pachmayer; M. Palka; Y. Parpottas; V. Pechenov; O. Pechenova; J. Pietraszko; W. Przygoda; B. Ramstein; A. Reshetin; M. Roy-Stephan; A. Rustamov; A. Sadovsky; B. Sailer; P. Salabura; A. Schmah; Yu. G. Sobolev; S. Spataro; B. Spruck; H. Ströbele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler; R. Trebacz; H. Tsertos; V. Wagner; M. Weber; M. Wisniowski; T. Wojcik; J. Wüstenfeld; S. Yurevich; Y. V. Zanevsky; P. Zhou

    2009-07-21T23:59:59.000Z

    We report first results on a deep sub-threshold production of the doubly strange hyperon $\\Xi^-$ in a heavy-ion reaction. At a beam energy of 1.76A GeV the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. A high-statistics and high-purity $\\Lambda$ sample was collected, allowing for the investigation of the decay channel $\\Xi^- \\to \\Lambda \\pi^-$. The deduced $\\Xi^-/(\\Lambda+\\Sigma^0)$ production ratio of $(5.6 \\pm 1.2 ^{+1.8}_{-1.7})\\cdot 10^{-3}$ is significantly larger than available model predictions.

  20. Flammability limits of dusts: Minimum inerting concentrations

    SciTech Connect (OSTI)

    Dastidar, A.G.; Amyotte, P.R. [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering] [Dalhousie Univ., Halifax, Nova Scotia (Canada). Dept. of Chemical Engineering; Going, J.; Chatrathi, K. [Fike Corp., Blue Springs, MO (United States)] [Fike Corp., Blue Springs, MO (United States)

    1999-05-01T23:59:59.000Z

    A new flammability limit parameter has been defined as the Minimum Inerting Concentration (MIC). This is the concentration of inertant required to prevent a dust explosion regardless of fuel concentration. Previous experimental work at Fike in a 1-m{sup 3} spherical chamber has shown this flammability limit to exist for pulverized coal dust and cornstarch. In the current work, inerting experiments with aluminum, anthraquinone and polyethylene dusts as fuels were performed, using monoammonium phosphate and sodium bicarbonate as inertants. The results show that an MIC exists only for anthraquinone inerted with sodium bicarbonate. The other combustible dust and inertant mixtures did not show a definitive MIC, although they did show a strong dependence between inerting level and suspended fuel concentration. As the fuel concentration increased, the amount of inertant required to prevent an explosion decreased. Even though a definitive MIC was not found for most of the dusts an effective MIC can be estimated from the data. The use of MIC data can aid in the design of explosion suppression schemes.

  1. LIMITS OF Nb3Sn ACCELERATOR MAGNETS

    SciTech Connect (OSTI)

    Caspi, Shlomo; Ferracin, Paolo

    2005-05-01T23:59:59.000Z

    Pushing accelerator magnets beyond 10 T holds a promise of future upgrades to machines like the Tevatron at Fermilab and the LHC at CERN. Exceeding the current density limits of NbTi superconductor, Nb{sub 3}Sn is at present the only practical superconductor capable of generating fields beyond 10 T. Several Nb{sub 3}Sn pilot magnets, with fields as high as 16 T, have been built and tested, paving the way for future attempts at fields approaching 20 T. High current density conductor is required to generate high fields with reduced conductor volume. However this significantly increases the Lorentz force and stress. Future designs of coils and structures will require managing stresses of several 100's of MPa and forces of 10's of MN/m. The combined engineering requirements on size and cost of accelerator magnets will involve magnet technology that diverges from the one currently used with NbTi conductor. In this paper we shall address how far the engineering of high field magnets can be pushed, and what are the issues and limitations before such magnets can be used in particle accelerators.

  2. Uncertainty quantification of limit-cycle oscillations

    SciTech Connect (OSTI)

    Beran, Philip S. [Multidisciplinary Technologies Center, Air Vehicles Directorate, AFRL/VASD, Building 146, 2210 Eighth Street, WPAFB, OH 45433 (United States)]. E-mail: philip.beran@wpafb.af.mil; Pettit, Chris L. [United States Naval Academy, 590 Holloway Rd., MS 11-B, Annapolis, MD 21402 (United States)]. E-mail: pettitcl@usna.edu; Millman, Daniel R. [USAF TPS/EDT, 220 South Wolfe Ave, Bldg. 1220, Rm. 131, Edwards AFB, CA 93524-6485 (United States)]. E-mail: daniel.millman@edwards.af.mil

    2006-09-01T23:59:59.000Z

    Different computational methodologies have been developed to quantify the uncertain response of a relatively simple aeroelastic system in limit-cycle oscillation, subject to parametric variability. The aeroelastic system is that of a rigid airfoil, supported by pitch and plunge structural coupling, with nonlinearities in the component in pitch. The nonlinearities are adjusted to permit the formation of a either a subcritical or supercritical branch of limit-cycle oscillations. Uncertainties are specified in the cubic coefficient of the torsional spring and in the initial pitch angle of the airfoil. Stochastic projections of the time-domain and cyclic equations governing system response are carried out, leading to both intrusive and non-intrusive computational formulations. Non-intrusive formulations are examined using stochastic projections derived from Wiener expansions involving Haar wavelet and B-spline bases, while Wiener-Hermite expansions of the cyclic equations are employed intrusively and non-intrusively. Application of the B-spline stochastic projection is extended to the treatment of aerodynamic nonlinearities, as modeled through the discrete Euler equations. The methodologies are compared in terms of computational cost, convergence properties, ease of implementation, and potential for application to complex aeroelastic systems.

  3. Search for Theta+ via pi- p --> K- X reaction near production threshold

    E-Print Network [OSTI]

    K. Miwa

    2006-02-24T23:59:59.000Z

    We have searched for $\\Theta^{+}$ via $\\pi^{-}p \\to K^{-}X$ reaction using 1.87 and 1.92 GeV/c $\\pi^{-}$ beam at the K2 beam line of the KEK 12 GeV Proton Synchrotron. In the missing mass spectrum at beam momentum of 1.92 GeV/$c$, a bump has been found at 1530 MeV/$c^{2}$ which is consistent with the mass reported by several experiments. The statistical significance of this bump, however, is only 2.5$-2.7\\sigma$. Therefore we have derived the upper limit of $\\Theta^{+}$ production cross section via $\\pi^{-}p \\to K^{-}\\Theta^{+}$ reaction which is 4.3$\\mu$b at 90% confidence level assuming that $\\Theta^{+}$ is produced isotropically in the center of mass system.

  4. Enhancement of RF Breakdown Threshold of Microwave Cavities by Magnetic Insulation

    SciTech Connect (OSTI)

    Stratakis, D.; Gallardo, J.; Palmer, R.B.

    2011-03-28T23:59:59.000Z

    Limitations on the maximum achievable accelerating gradient of microwave cavities can influence the performance, length, and cost of particle accelerators. Gradient limitations are believed to be initiated by electron emission from the cavity surfaces. Here, we show that field emission is effectively suppressed by applying a tangential magnetic field to the cavity walls, so higher gradients can be achieved. Numerical simulations indicate that the magnetic field prevents electrons leaving these surfaces and subsequently picking up energy from the electric field. Our results agree with current experimental data. Two specific examples illustrate the implementation of magnetic insulation into prospective particle accelerator applications. The ultimate goal of several research efforts is to integrate high-gradient radio-frequency (rf) structures into next generation particle accelerators. For instance, the Muon Accelerator Program is looking at developing low-frequency cavities for muon cooling, and the International Linear Collider is optimizing the performance of 1.3 GHz rf structures aimed at designing a 1 TeV electron-positron collider. Furthermore, the High Gradient RF Collaboration is examining high frequency (f > 10 GHz) structures intended for an electron-positron collider operating at energies in the TeV range. In all this research, the accelerating gradient will be one of the crucial parameters affecting their design, construction, and cost. Limitations from rf breakdown strongly influence the development of accelerators since it limits the machine's maximum gradient. The emission of electrons from the cavity surfaces seemingly is a necessary stage in the breakdown process, acting either as a direct cause of breakdown or as precursor for other secondary effects. Typically, electron currents arise from sharp edges or cracks on the cavities surfaces, where the strength of the electric field is strongly enhanced compared to that of the nominal field when the surfaces of the cavity are perfect planes. Subsequently, a stream of emitted electrons can be accelerated by the rf electric field toward the opposing cavity walls. Upon impact, they heat a localized region, resulting in the eventual breakdown by a variety of secondary mechanisms. Therefore, it is advantageous to develop techniques that could suppress field emission within rf cavities. It has been proposed that high voltages up to about a gigavolt range may be sustained in voltage transformers, by adopting the principle of magnetic insulation in ultrahigh vacuum. The basic idea is to suppress field emission by applying a suitably directed magnetic field of sufficient strength to force the electrons orbits back on to the rf emitting surface. More recently, it was shown that magnetic insulation could be very effective in suppressing field emission and multipacting in rectangular coupler waveguides. Hence, the question arises whether the same principle is applicable to rf accelerating structures. In this Letter, we shall consider application of the concept to low-frequency (201-805 MHz) muon accelerator cavities.

  5. Transition threshold in Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses

    SciTech Connect (OSTI)

    Wei, Wen-Hou [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Fang, Liang, E-mail: lfang@cqu.edu.cn [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Shen, Xiang [Laboratory of Infrared Material and Devices, Advanced Technology Research Institute, Ningbo University, Ningbo 315211 (China); Wang, Rong-Ping [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2014-03-21T23:59:59.000Z

    Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses with Ge content from 7.5 to 32.5?at.?% have been prepared by melt-quench technique, and the physical parameters including glass transition temperature (T{sub g}), density (?), compactness (C), shear elastic moduli (C{sub s}), compression elastic moduli (C{sub c}), refractive index (n), and optical bandgap (E{sub g}) have been investigated. While all these physical parameters show threshold behavior in the glass with a chemically stoichiometric composition. Raman spectra analysis also indicates that, with increasing Ge content, Se-chains or rings gradually disappear until all Se-atoms are consumed in the glass with a chemically stoichiometric composition. With further increasing Ge content, homopolar Ge-Ge and Sb-Sb bonds are formed and the chemical order in the glasses is violated. The threshold behavior of the physical properties in the Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses can be traced to demixing of networks above the chemically stoichiometric composition.

  6. Dressed-bound-state molecular strong-field approximation: Application to above-threshold ionization of heteronuclear diatomic molecules

    SciTech Connect (OSTI)

    Hasovic, E. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, BA-71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, DE-12489 Berlin (Germany); Busuladzic, M. [Medical Faculty, University of Sarajevo, Cekalusa 90, BA-71000 Sarajevo (Bosnia and Herzegowina); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, DE-12489 Berlin (Germany); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, BA-71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, DE-12489 Berlin (Germany); Academy of Sciences and Arts of Bosnia and Herzegovina, Bistrik 7, BA-71000 Sarajevo (Bosnia and Herzegowina)

    2011-12-15T23:59:59.000Z

    The molecular strong-field approximation (MSFA), which includes dressing of the molecular bound state, is introduced and applied to above-threshold ionization of heteronuclear diatomic molecules. Expressions for the laser-induced molecular dipole and polarizability as functions of the laser parameters (intensity and frequency) and molecular parameters [molecular orientation, dipole, and parallel and perpendicular polarizabilities of the highest occupied molecular orbital (HOMO)] are presented. Our previous MSFA theory, which incorporates the rescattering effects, is generalized from homonuclear to heteronuclear diatomic molecules. Angle- and energy-resolved high-order above-threshold ionization spectra of oriented heteronuclear diatomic molecules, exemplified by the carbon monoxide (CO) molecule, exhibit pronounced minima, which can be related to the shape of their HOMO-electron-density distribution. For the CO molecule we have found an analytical condition for the positions of these minima. We have also shown that the effect of the dressing of the HOMO is twofold: (i) the laser-induced Stark shift decreases the ionization yield and (ii) the laser-induced time-dependent dipole and polarizability change the oscillatory structure of the spectra.

  7. Ultralow-threshold laser and blue shift cooperative luminescence in a Yb{sup 3+} doped silica microsphere

    SciTech Connect (OSTI)

    Huang, Yantang, E-mail: g@fzu.edu.cn; Huang, Yu; Zhang, Peijin [College of Physics and Information Engineering, Fuzhou University, Fu Zhou, 350108 (China)] [College of Physics and Information Engineering, Fuzhou University, Fu Zhou, 350108 (China); Guo, Changlei [College of Physics and Information Engineering, Fuzhou University, Fu Zhou, 350108 (China) [College of Physics and Information Engineering, Fuzhou University, Fu Zhou, 350108 (China); Department of Electronic Engineering, Institute of Optoelectronic Technology, Xiamen University, Xiamen, 361005 (China)

    2014-02-15T23:59:59.000Z

    An experimental investigation on ultralow threshold laser and blue shift cooperative luminescence (CL) in a Yb{sup 3+} doped silica microsphere (YDSM) with continuous-wave 976 nm laser diode pumping is reported. The experimental results show that the YDSM emits laser oscillation with ultralow threshold of 2.62 ?W, and the laser spectrum is modulated by the microsphere morphology characteristics. In addition, blue emission of YDSM is also observed with the increase of pump power, which is supposed to be generated by CL of excited Yb ion-pairs with the absorption of 976 nm photons and Si-O vibration phonons, and the process is explained with an energy level diagram. This property of the blue shift CL with phonons absorption in the Yb{sup 3+}doped microcavity makes it attractive for the application of laser cooling based on anti-Stokes fluorescence emission, if the Yb{sup 3+}doped microcavity made from with low phonon energy host materials.

  8. Lowering the background level and the energy threshold of Micromegas x-ray detectors for axion searches

    E-Print Network [OSTI]

    F. J. Iguaz; S. Aune; F. Aznar; J. F. Castel; T. Dafni; M. Davenport; E. Ferrer-Ribas; J. Galan; J. A. Garcia; J. G. Garza; I. Giomataris; I. G. Irastorza; T. Papaevangelou; A. Rodriguez; A. Tomas; T. Vafeiadis; S. C. Yildiz

    2015-01-07T23:59:59.000Z

    Axion helioscopes search for solar axions by their conversion in x-rays in the presence of high magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. In this work, we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The actual setup in CAST has achieved background levels below 10$^{-6}$ keV$^{-1}$ cm$^{-2}$ s$^{-1}$, a factor 100 lower than the first generation of Micromegas detectors. This reduction is based on active and passive shielding techniques, the selection of radiopure materials, offline discrimination techniques and the high granularity of the readout. We describe in detail the background model of the detector, based on its operation at CAST site and at the Canfranc Underground Laboratory (LSC), as well as on Geant4 simulations. The best levels currently achieved at LSC are low than 10$^{-7}$ keV$^{-1}$ cm$^{-2}$ s$^{-1}$ and show good prospects for the application of this technology in IAXO. Finally, we present some ideas and results for reducing the energy threshold of these detectors below 1 keV, using high-transparent windows, autotrigger electronics and studying the cluster shape at different energies. As a high flux of axion-like-particles is expected in this energy range, a sub-keV threshold detector could enlarge the physics case of axion helioscopes.

  9. Damage threshold of inorganic solids under free-electron-laser irradiation at 32.5 nm wavelength

    SciTech Connect (OSTI)

    Hau-Riege, S; London, R A; Bionta, R M; McKernan, M A; Baker, S L; Krzywinski, J; Sobierajski, R; Nietubyc, R; Pelka, J B; Jurek, M; Klinger, D; Juha, L; Chalupsky, J; Cihelka, J; Hajkova, V; Koptyaev, S; Velyhan, A; Krasa, J; Kuba, J; Tiedtke, K; Toleikis, S; Tschentscher, T; Wabnitz, H; Bergh, M; Caleman, C; Sokolowski-Tinten, K; Stojanovic, N; Zastrau, U; Tronnier, A; Meyer-ter-Vehn, J

    2007-12-03T23:59:59.000Z

    We exposed samples of B4C, amorphous C, chemical-vapor-deposition (CVD)-diamond C, Si, and SiC to single 25 fs-long pulses of 32.5 nm free-electron-laser radiation at fluences of up to 2.2 J/cm{sup 2}. The samples were chosen as candidate materials for x-ray free electron laser (XFEL) optics. We found that the threshold for surface-damage is on the order of the fluence required for thermal melting. For larger fluences, the crater depths correspond to temperatures on the order of the critical temperature, suggesting that the craters are formed by two-phase vaporization [1]. XFELs have the promise of producing extremely high-intensity ultrashort pulses of coherent, monochromatic radiation in the 1 to 10 keV regime. The expected high output fluence and short pulse duration pose significant challenges to the optical components, including radiation damage. It has not been possible to obtain direct experimental verification of the expected damage thresholds since appropriate x-ray sources are not yet available. FLASH has allowed us to study the interaction of high-fluence short-duration photon pulses with materials at the shortest wavelength possible to date. With these experiments, we have come closer to the extreme conditions expected in XFEL-matter interaction scenarios than previously possible.

  10. Quantum probabilities and violation of CHSH-inequality from classical random signals and threshold type properly calibrated detectors

    E-Print Network [OSTI]

    Andrei Khrennikov

    2011-12-03T23:59:59.000Z

    We present a purely wave model (based on classical random field) which reproduces quantum probabilities (given by the fundamental law of quantum mechanics, Born's rule) including probabilities for joint detection of a pair of quantum observables (e.g., spin or polarization projections). The crucial point of our approach is that the presence of detector's threshold and calibration procedure have to be treated not as simply experimental technicalities, but as the basic counteparts of the theoretical model. The presence of the background field (vacuum fluctuations) is also the key-element of our prequantum model. It is of the classical signal type and the methods of classical signal theory (including statistical radiophysics) are used for its development. We stress that our prequantum model is not objective, i.e., the values of observables (clicks of detectors) cannot be assigned in advance, i.e., before measurement. Hence, the dilemma, nonobjectivity or nonlocality, is resolved in favor of nonobjectivity (our model is local of the classical field type). In particular, we reproduce the probabilities for the EPR-experiment for photon polarization and, hence, violate CHSH inequality for classical random signals (measured by the threshold type and properly calibrated detectors acting in the presence of the background field).

  11. Intensity Limitations in Fermilab Main Injector

    SciTech Connect (OSTI)

    Chan, W.

    1997-06-01T23:59:59.000Z

    The design beam intensity of the FNAL Main Injector (MI) is 3 x 10{sup 13} ppp. This paper investigates possible limitations in the intensity upgrade. These include the space charge, transition crossing, microwave instability, coupled bunch instability, resistive wall, beam loading (static and transient), rf power, aperture (physical and dynamic), coalescing, particle losses and radiation shielding, etc. It seems that to increase the intensity by a factor of two from the design value is straightforward. Even a factor of five is possible provided that the following measures are to be taken: an rf power upgrade, a {gamma}{sub t}-jump system, longitudinal and transverse feedback systems, rf feedback and feedforward, stopband corrections and local shieldings.

  12. Neutral depletion and the helicon density limit

    SciTech Connect (OSTI)

    Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E. [West Virginia University, Morgantown, West Virginia 26506 (United States)] [West Virginia University, Morgantown, West Virginia 26506 (United States)

    2013-12-15T23:59:59.000Z

    It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup ?3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 ?s. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

  13. Instability limits for spontaneous double layer formation

    SciTech Connect (OSTI)

    Carr, J. Jr. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States) [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Department of Physics, Texas Lutheran University, Seguin, Texas 78155 (United States); Galante, M. E.; McCarren, D.; Scime, E. E.; Sears, S.; VanDervort, R. W. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)] [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Magee, R. M. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States) [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); TriAlpha Energy, Inc., Foothill Ranch, California 92610 (United States); Reynolds, E. [Department of Physics and Engineering, West Virginia Wesleyan, Buckhannon, West Virginia 26201 (United States)] [Department of Physics and Engineering, West Virginia Wesleyan, Buckhannon, West Virginia 26201 (United States)

    2013-11-15T23:59:59.000Z

    We present time-resolved measurements that demonstrate that large amplitude electrostatic instabilities appear in pulsed, expanding helicon plasmas at the same time as particularly strong double layers appear in the expansion region. A significant cross-correlation between the electrostatic fluctuations and fluctuations in the number of ions accelerated by the double layer electric field is observed. No correlation is observed between the electrostatic fluctuations and ions that have not passed through the double layer. These measurements confirm that the simultaneous appearance of the electrostatic fluctuations and the double layer is not simple coincidence. In fact, the accelerated ion population is responsible for the growth of the instability. The double layer strength, and therefore, the velocity of the accelerated ions, is limited by the appearance of the electrostatic instability.

  14. Quantum limits to estimation of photon deformation

    E-Print Network [OSTI]

    Giovanni De Cillis; Matteo G. A. Paris

    2014-07-08T23:59:59.000Z

    We address potential deviations of radiation field from the bosonic behaviour and employ local quantum estimation theory to evaluate the ultimate bounds to precision in the estimation of these deviations using quantum-limited measurements on optical signals. We consider different classes of boson deformation and found that intensity measurement on coherent or thermal states would be suitable for their detection making, at least in principle, tests of boson deformation feasible with current quantum optical technology. On the other hand, we found that the quantum signal-to-noise ratio (QSNR) is vanishing with the deformation itself for all the considered classes of deformations and probe signals, thus making any estimation procedure of photon deformation inherently inefficient. A partial way out is provided by the polynomial dependence of the QSNR on the average number of photon, which suggests that, in principle, it would be possible to detect deformation by intensity measurements on high-energy thermal states.

  15. Remotely replaceable tokamak plasma limiter tiles

    DOE Patents [OSTI]

    Tsuo, Simon (Lakewood, CO), Langford, Alison A. (Boulder, CO)

    1989-01-01T23:59:59.000Z

    U-shaped limiter tiles placed end-to-end over a pair of parallel runners secured to a wall have two rods which engage L-shaped slots in the runners. The short receiving legs of the L-shaped slots are perpendicular to the wall and open away from the wall, while long retaining legs are parallel to and adjacent the wall. A sliding bar between the runners has grooves with clips to retain the rods pressed into receiving legs of the L-shaped slots in the runners. Sliding the bar in the direction of retaining legs of the L-shaped slots latches the tiles in place over the runners. Resilient contact strips between the parallel arms of the U-shaped tiles and the wall assure thermal and electrical contact with the wall.

  16. Limits and Fits from Simplified Models

    E-Print Network [OSTI]

    Sonneveld, Jory

    2015-01-01T23:59:59.000Z

    An important tool for interpreting LHC searches for new physics are simplified models. They are characterized by a small number of parameters and thus often rely on a simplified description of particle production and decay dynamics. We compare the interpretation of current LHC searches for hadronic jets plus missing energy signatures within simplified models with the interpretation within complete supersymmetric and same-spin models of quark partners. We found that the differences between the mass limits derived from a simplified model and from the complete models are moderate given the current LHC sensitivity. We conclude that simplified models provide a reliable tool to interpret the current hadronic jets plus missing energy searches at the LHC in a more model-independent way.

  17. Ideal Quantum Gases with Planck Scale Limitations

    E-Print Network [OSTI]

    Collier, Rainer

    2015-01-01T23:59:59.000Z

    A thermodynamic system of non-interacting quantum particles changes its statistical distribution formulas if there is a universal limitation for the size of energetic quantum leaps (magnitude of quantum leaps smaller than Planck energy). By means of a restriction of the a priori equiprobability postulate one can reach a thermodynamic foundation of these corrected distribution formulas. The number of microstates is determined by means of a suitable counting method and combined with thermodynamics via the Boltzmann principle. The result is that, for particle energies that come close to the Planck energy, the thermodynamic difference between fermion and boson distribution vanishes. Both distributions then approximate a Boltzmann distribution. The wave and particle character of the quantum particles, too, can be influenced by choosing the size of the temperature and particle energy parameters relative to the Planck energy, as you can see from the associated fluctuation formulas. In the case of non-relativistic de...

  18. Self field triggered superconducting fault current limiter

    DOE Patents [OSTI]

    Tekletsadik, Kasegn D. (Rexford, NY)

    2008-02-19T23:59:59.000Z

    A superconducting fault current limiter array with a plurality of superconductor elements arranged in a meanding array having an even number of supconductors parallel to each other and arranged in a plane that is parallel to an odd number of the plurality of superconductors, where the odd number of supconductors are parallel to each other and arranged in a plane that is parallel to the even number of the plurality of superconductors, when viewed from a top view. The even number of superconductors are coupled at the upper end to the upper end of the odd number of superconductors. A plurality of lower shunt coils each coupled to the lower end of each of the even number of superconductors and a plurality of upper shunt coils each coupled to the upper end of each of the odd number of superconductors so as to generate a generally orthoganal uniform magnetic field during quenching using only the magenetic field generated by the superconductors.

  19. Efficiency limits of quantum well solar cells

    E-Print Network [OSTI]

    Connolly, J P; Barnham, K W J; Bushnell, D B; Tibbits, T N D; Roberts, J S

    2010-01-01T23:59:59.000Z

    The quantum well solar cell (QWSC) has been proposed as a flexible means to ensuring current matching for tandem cells. This paper explores the further advantage afforded by the indication that QWSCs operate in the radiative limit because radiative contribution to the dark current is seen to dominate in experimental data at biases corresponding to operation under concentration. The dark currents of QWSCs are analysed in terms of a light and dark current model. The model calculates the spectral response (QE) from field bearing regions and charge neutral layers and from the quantum wells by calculating the confined densities of states and absorption coefficient, and solving transport equations analytically. The total dark current is expressed as the sum of depletion layer and charge neutral radiative and non radiative currents consistent with parameter values extracted from QE fits to data. The depletion layer dark current is a sum of Shockley-Read-Hall non radiative, and radiative contributions. The charge neu...

  20. Computation on Spin Chains with Limited Access

    E-Print Network [OSTI]

    Kay, Alastair

    2009-01-01T23:59:59.000Z

    We discuss how to implement quantum computation on a system with an intrinsic Hamiltonian by controlling a limited subset of spins. Our primary result is an efficient control sequence on a chain of hopping, non-interacting, fermions through control of a single site and its interaction with its neighbor. This is applicable to a wide class of spin chains through the Jordan-Wigner transformation. We also discuss how an array of sites can be controlled to give sufficient parallelism for the implementation of fault-tolerant circuits. The framework provides a vehicle to expose the contradictions between the control theoretic concept of controllability with the ability of a system to perform quantum computation.

  1. Continuum limit of lattice gas fluid dynamics

    SciTech Connect (OSTI)

    Teixeira, C.M.

    1992-01-01T23:59:59.000Z

    The general theory for multiple-speed lattice gas algorithm (LGAs) is developed where previously only a single-speed theory existed. A series of microdynamical multiple-speed models are developed that effectively erase the underlying lattice from the macroscopic dynamics allowing the LGA to reproduce the results of continuum hydrodynamics exactly. The underlying lattice is the 4D FCHC lattice. This lattice: (1) Permits all integral energies, (2) Has sufficient symmetry to allow for an isotropic stress tensor for each energy individually, (3) Allows interaction amongst all energies, and (4) Has discrete microscopic Galilean invariance, all of which allows the extension of the model to higher-speeds. This lattice is the only regular lattice with these remarkable properties, all of which are required to show that the discreteness artifacts completely disappear from the LGA in the limit of infinite speeds, so that correct continuum hydrodynamic behavior results. The author verifies the removal of the discreteness artifacts from the momentum equation using a decaying shear wave experiment and shows they are still invisible for Mach numbers up to M [approximately].4 beyond the theoretical limit. Flow between flat plates replicated the expected parabolic profile of Poiseuille flow in the mean when started from rest. Two separate measurements of the kinematic viscosity of the fluid (normal pressure drop and the microscopic particle force at the wall) agreed with each other and with the shear wave viscosity to better than 1%. Cylinder flow simulations accurately reproduced drag coefficients and eddy-length to diameter ratios for Re[le]45 to within the error of experimental observation. At higher Reynolds number, Re [approx equal] 65, vortex shedding was observed to occur. CFD results for flow past cylinders at similar Reynolds numbers produce either erroneous results or rely on artificially perturbing the flow to cause phenomena that does not occur naturally in the method.

  2. Threshold singularities in a Fermi gas with attractive potential in one dimension

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schlottmann, P.; Zvyagin, A.A.

    2015-03-01T23:59:59.000Z

    We consider the one-dimensional gas of fermions with spin S interacting via an attractive ?-function potential using the Bethe Ansatz solution. In zero magnetic field the atoms form bound states of N=2S+1 fermions, i.e. generalized Cooper states with each atom having a different spin component. For low energy excitations the system is a Luttinger liquid and is properly described by a conformal field theory with conformal charge c=1. The linear dispersion of a Luttinger liquid is asymptotically exact in the low-energy limit where the band curvature terms in the dispersion are irrelevant. For higher energy excitations, however, the spectral functionmore »displays deviations in the neighborhood of the single-particle (hole) energy, which can be described by an effective X-ray edge type model. Using the Bethe Ansatz solution we obtain expressions for the critical exponents for the single-particle (hole) Green’s function. This model can be relevant in the context of ultracold atoms with effective total spin Sconfined to an elongated optical trap.« less

  3. Characteristics of the TFTR limiter H-mode: The transition, ELMs, transport and confinement

    SciTech Connect (OSTI)

    Bush, C.E. (Oak Ridge National Lab., TN (United States)); Bretz, N.; Nazikian, R.; Stratton, B.C.; Synakowski, E.; Taylor, G. Budny, R.; Ramsey, A.T.; Scott, S.D.; Bell, M.; Bell, R.; Biglari, H.; Bitter, M.; Darrow, D.S.; Efthimion, P.; Fredrickson, E.D.; Hill, K.; Hsuan, H.; Kilpatrick, S.; McGuire, K.M.; Manos, D.; Mansfield, D.; Medley, S.S.; Mueller, D.; Park, H.; Paul, S.; Sabbagh, S.; Schivell, J.; Thompson, M.; Town

    1992-11-01T23:59:59.000Z

    H-Modes obtained through transitions from the supershot regime have been studied on TFTR. The characteristics of these H-modes are similar to those found on other tokamaks with one main exception, the density prof:des can be highly peaked. In the best cases the enhanced confinement in the core of the initial supershot is retained in the H-mode phase, while the confinement in a broad edge region is enhanced. Thus in TFTR, all of the important physics of H-modes such as transitions, enhanced edge confinement, ELMs and other phenomena are studied in a large circular limiter tokamak with the added feature of centrally peaked density profiles and the advantage of an extensive set of diagnostics. The threshold power for the transition is found to be a linear function of plasma current. Transitions and ELMs are affected by the mix of co-and counter-neutral beam injection (NBI) and by perturbations introduced by pellet injection, gas puffing, and current ramping before and during NBI. Fluctuations near both transition and ELM events have been characterized. High frequency magnetic fluctuations in the range [ge] 100--250 kHz usually decrease during the transition. Microwave scattering spectra of density fluctuations in the plasma edge show a feature at high frequency during the H-mode, which is not observed in the plasma core and which is consistent with an edge poloidal rotation velocity, V[sub [theta

  4. Limits on Fast Radio Bursts at 145 MHz with ARTEMIS, a real-time software backend

    E-Print Network [OSTI]

    Karastergiou, A; Armour, W; Williams, C; Mort, B; Dulwich, F; Salvini, S; Magro, A; Roberts, S; Serylak, M; Doo, A; Bilous, A V; Breton, R P; Falcke, H; Griessmeier, J -M; Hessels, J W T; Keane, E F; Kondratiev, V I; Kramer, M; van Leeuwen, J; Noutsos, A; Oslowski, S; Sobey, C; Stappers, B W; Weltevrede, P

    2015-01-01T23:59:59.000Z

    Fast Radio Bursts (FRBs), are millisecond radio signals that exhibit dispersion larger than what the Galactic electron density can account for. We have conducted a 1446 hour survey for Fast Radio Bursts (FRBs) at 145~MHz, covering a total of 4193 sq. deg on the sky. We used the UK station of the LOFAR radio telescope -- the Rawlings Array -- , accompanied for a majority of the time by the LOFAR station at Nan\\c{c}ay, observing the same fields at the same frequency. Our real-time search backend, ARTEMIS, utilizes graphics processing units to search for pulses with dispersion measures up to 320 cm$^{-3}$ pc. Previous derived FRB rates from surveys around 1.4~GHz, and favoured FRB interpretations, motivated this survey, despite all previous detections occurring at higher dispersion measures. We detected no new FRBs above a signal-to-noise threshold of 10, leading to the most stringent upper limit yet on the FRB event rate at these frequencies: 29 sky$^{-1}$ day$^{-1}$ for 5~ms-duration pulses above 62~Jy. The no...

  5. Limits on Very High Energy Emission from Gamma-Ray Bursts with the Milagro Observatory

    E-Print Network [OSTI]

    Atkins, R; Berley, D; Blaufuss, E; Bussons, J; Coyne, D G; De Young, T R; Dingus, B L; Dorfan, D E; Ellsworth, R W; Fleysher, L; Fleysher, R; Gisler, G; González, M M; Goodman, J A; Haines, T J; Hays, E; Hoffman, C M; Kelley, L A; McEnery, J E; Miller, R S; Mincer, A I; Morales, M F; Némethy, P; Noyes, D; Ryan, J M; Samuelson, F W; Shoup, A L; Sinnis, G; Smith, A J; Sullivan, G W; Williams, D A; Westerhoff, S; Wilson, M E; Xu, X; Yodh, G B

    2004-01-01T23:59:59.000Z

    The Milagro telescope monitors the northern sky for 100 GeV to 100 TeV transient emission through continuous very high energy wide-field observations. The large effective area and ~100 GeV energy threshold of Milagro allow it to detect very high energy (VHE) gamma-ray burst emission with much higher sensitivity than previous instruments and a fluence sensitivity at VHE energies comparable to that of dedicated gamma-ray burst satellites at keV to MeV energies. Even in the absence of a positive detection, VHE observations can place important constraints on gamma-ray burst (GRB) progenitor and emission models. We present limits on the VHE flux of 40 s -- 3 h duration transients nearby to earth, as well as sensitivity distributions which have been corrected for gamma-ray absorption by extragalactic background light and cosmological effects. The sensitivity distributions suggest that the typical intrinsic VHE fluence of GRBs is similar or weaker than the keV -- MeV emission, and we demonstrate how these sensitivit...

  6. Limits on Very High Energy Emission from Gamma-Ray Bursts with the Milagro Observatory

    E-Print Network [OSTI]

    The Milagro Collaboration; R. Atkins; W. Benbow; D. Berley; E. Blaufuss; J. Bussons; D. G. Coyne; T. DeYoung; B. L. Dingus; D. E. Dorfan; R. W. Ellsworth; L. Fleysher; R. Fleysher; G. Gisler; M. M. Gonzalez; J. A. Goodman; T. J. Haines; E. Hays; C. M. Hoffman; L. A. Kelley; J. E. McEnery; R. S. Miller; A. I. Mincer; M. F. Morales; P. Nemethy; D. Noyes; J. M. Ryan; F. W. Samuelson; A. Shoup; G. Sinnis; A. J. Smith; G. W. Sullivan; D. A. Williams; S. Westerhoff; M. E. Wilson; X. Xu; G. B. Yodh

    2004-02-06T23:59:59.000Z

    The Milagro telescope monitors the northern sky for 100 GeV to 100 TeV transient emission through continuous very high energy wide-field observations. The large effective area and ~100 GeV energy threshold of Milagro allow it to detect very high energy (VHE) gamma-ray burst emission with much higher sensitivity than previous instruments and a fluence sensitivity at VHE energies comparable to that of dedicated gamma-ray burst satellites at keV to MeV energies. Even in the absence of a positive detection, VHE observations can place important constraints on gamma-ray burst (GRB) progenitor and emission models. We present limits on the VHE flux of 40 s -- 3 h duration transients nearby to earth, as well as sensitivity distributions which have been corrected for gamma-ray absorption by extragalactic background light and cosmological effects. The sensitivity distributions suggest that the typical intrinsic VHE fluence of GRBs is similar or weaker than the keV -- MeV emission, and we demonstrate how these sensitivity distributions may be used to place observational constraints on the absolute VHE luminosity of gamma-ray bursts for any GRB emission and progenitor model.

  7. Energy-Limited vs. Interference-Limited Ad Hoc Network Capacity

    E-Print Network [OSTI]

    Jindal, Nihar

    , signal and interference power increase proportionally while thermal noise power remains constant. Thus are thermal noise and multi- user interference. If the power of each simultaneous trans- mission is increased-limited, and any further increase in transmission power provides essentially no benefit. On the other hand, thermal

  8. Pushing beam currents to the limit

    SciTech Connect (OSTI)

    Stevenson, N.R.; Nortier, F.M.; Gelbart, W.Z.; Bloemhard, R.; Elzen, R. van den; Hunt, C.; Lofvendahl, J.; Orzechowski, J. [TRIUMF, British Columbia (Canada)

    1994-12-31T23:59:59.000Z

    One of the cyclotron systems running at the Nordion Int. radioisotope production facility at TRIUMF is the EBCO TR30. This cyclotron produces up to 250 {mu}A on each of two beamlines simultaneously. Two solid (for the production of {sup 201}Tl, {sup 57}Co, {sup 67}Ga and {sup 111}In) and a gaseous (for producing {sup 123}I) target station are in routine operation on this facility. Since future projections indicate a greater demand for reliable radioisotope production there is a program underway to increase the output of the facility to double the present level. One way that this is being achieved is through a careful thermal analysis of the solid target system to maximize its performance. In conjunction with this, the authors have developed and tested a 500 {mu}A upgrade of the solid target system. Gas targets are being investigated for possible ways of increasing the efficiency of production via rotating/sweeping beams which allow higher beam currents. Finally, the TR30 cyclotron is being upgraded to deliver 50-100% more beam on target. By pushing both the cyclotron and target technology to the limit will produce significantly higher levels of radioisotopes than many other comparable facilities.

  9. Flow reversal power limit for the HFBR

    SciTech Connect (OSTI)

    Cheng, L.Y.; Tichler, P.R.

    1997-01-01T23:59:59.000Z

    The High Flux Beam Reactor (HFBR) is a pressurized heavy water moderated and cooled research reactor that began operation at 40 MW. The reactor was subsequently upgraded to 60 MW and operated at that level for several years. The reactor undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Questions which were raised about the afterheat removal capability during the flow reversal transition led to a reactor shutdown and subsequent resumption of operation at a reduced power of 30 MW. An experimental and analytical program to address these questions is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW. Direct use of the experimental results and an understanding of the governing phenomenology supports this conclusion.

  10. Limits on New Physics from Black Holes

    E-Print Network [OSTI]

    Clifford Cheung; Stefan Leichenauer

    2014-08-02T23:59:59.000Z

    Black holes emit high energy particles which induce a finite density potential for any scalar field $\\phi$ coupling to the emitted quanta. Due to energetic considerations, $\\phi$ evolves locally to minimize the effective masses of the outgoing states. In theories where $\\phi$ resides at a metastable minimum, this effect can drive $\\phi$ over its potential barrier and classically catalyze the decay of the vacuum. Because this is not a tunneling process, the decay rate is not exponentially suppressed and a single black hole in our past light cone may be sufficient to activate the decay. Moreover, decaying black holes radiate at ever higher temperatures, so they eventually probe the full spectrum of particles coupling to $\\phi$. We present a detailed analysis of vacuum decay catalyzed by a single particle, as well as by a black hole. The former is possible provided large couplings or a weak potential barrier. In contrast, the latter occurs much more easily and places new stringent limits on theories with hierarchical spectra. Finally, we comment on how these constraints apply to the standard model and its extensions, e.g. metastable supersymmetry breaking.

  11. The ultimate downscaling limit of FETs.

    SciTech Connect (OSTI)

    Mamaluy, Denis; Gao, Xujiao; Tierney, Brian David

    2014-10-01T23:59:59.000Z

    We created a highly efficient, universal 3D quant um transport simulator. We demonstrated that the simulator scales linearly - both with the problem size (N) and number of CPUs, which presents an important break-through in the field of computational nanoelectronics. It allowed us, for the first time, to accurately simulate and optim ize a large number of realistic nanodevices in a much shorter time, when compared to other methods/codes such as RGF[~N 2.333 ]/KNIT, KWANT, and QTBM[~N 3 ]/NEMO5. In order to determine the best-in-class for different beyond-CMOS paradigms, we performed rigorous device optimization for high-performance logic devices at 6-, 5- and 4-nm gate lengths. We have discovered that there exists a fundamental down-scaling limit for CMOS technology and other Field-Effect Transistors (FETs). We have found that, at room temperatures, all FETs, irre spective of their channel material, will start experiencing unacceptable level of thermally induced errors around 5-nm gate lengths.

  12. Limited-field radiation for bifocal germinoma

    SciTech Connect (OSTI)

    Lafay-Cousin, Lucie [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada)]. E-mail: lucie.lafay-cousin@sickkids.ca; Millar, Barbara-Ann [Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario (Canada); Mabbott, Donald [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Psychology, Hospital for Sick Children, Toronto, Ontario (Canada); Spiegler, Brenda [Department of Psychology, Hospital for Sick Children, Toronto, Ontario (Canada); Drake, Jim [Department of Neurosurgery, Hospital for Sick Children, Toronto, Ontario (Canada); Bartels, Ute [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada); Huang, Annie [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada); Bouffet, Eric [Pediatric Brain Tumor Program, Hospital for Sick Children, Toronto, Ontario (Canada)

    2006-06-01T23:59:59.000Z

    Purpose: To report the incidence, characteristics, treatment, and outcomes of bifocal germinomas treated with chemotherapy followed by focal radiation. Methods and Materials: This was a retrospective review. Inclusion criteria included radiologic diagnosis of bifocal germinoma involving the pineal and neurohypophyseal region, no evidence of dissemination on spinal MRI, negative results from cerebrospinal fluid cytologic evaluation, and negative tumor markers. Results: Between 1995 and 2004, 6 patients (5 male, 1 female; median age, 12.8 years) fulfilled the inclusion criteria. All had symptoms of diabetes insipidus at presentation. On MRI, 4 patients had a pineal and suprasellar mass, and 2 had a pineal mass associated with abnormal neurohypophyseal enhancement. All patients received chemotherapy followed by limited-field radiation and achieved complete remission after chemotherapy. The radiation field involved the whole ventricular system (range, 2,400-4,000 cGy) with or without a boost to the primary lesions. All patients remain in complete remission at a median follow-up of 48.1 months (range, 9-73.4 months). Conclusions: This experience suggests that bifocal germinoma can be considered a locoregional rather than a metastatic disease. Chemotherapy and focal radiotherapy might be sufficient to provide excellent outcomes. Staging refinement with new diagnostic tools will likely increase the incidence of the entity.

  13. Reliability of dynamic systems under limited information.

    SciTech Connect (OSTI)

    Field, Richard V., Jr. (.,; .); Grigoriu, Mircea

    2006-09-01T23:59:59.000Z

    A method is developed for reliability analysis of dynamic systems under limited information. The available information includes one or more samples of the system output; any known information on features of the output can be used if available. The method is based on the theory of non-Gaussian translation processes and is shown to be particularly suitable for problems of practical interest. For illustration, we apply the proposed method to a series of simple example problems and compare with results given by traditional statistical estimators in order to establish the accuracy of the method. It is demonstrated that the method delivers accurate results for the case of linear and nonlinear dynamic systems, and can be applied to analyze experimental data and/or mathematical model outputs. Two complex applications of direct interest to Sandia are also considered. First, we apply the proposed method to assess design reliability of a MEMS inertial switch. Second, we consider re-entry body (RB) component vibration response during normal re-entry, where the objective is to estimate the time-dependent probability of component failure. This last application is directly relevant to re-entry random vibration analysis at Sandia, and may provide insights on test-based and/or model-based qualification of weapon components for random vibration environments.

  14. Low-threshold (--600 A/cm/sup 2/ at room temperature) GaAs/AlGaAs lasers on Si (100)

    SciTech Connect (OSTI)

    Chen, H.Z.; Ghaffari, A.; Wang, H.; Morkoc, H.; Yariv, A.

    1987-10-26T23:59:59.000Z

    Low-threshold graded-refractive-index GaAs/AlGaAs laser structures were grown on Si (100) by molecular beam epitaxy and tested at room temperature under a probe station. Broad area devices having widths of 110--120 ..mu..m and cavity lengths of --500--1210 ..mu..m exhibited threshold current densities as low as 600 A/cm/sup 2/ and total slope efficiencies of as high as 0.75 W/A. The thresholds fell in the range of 600--1000 A/cm/sup 2/ in three different wafers, and it is assumed that the quality of the facets accounts for most of the spread in results.

  15. Determination of the melting threshold of TiO{sub 2} thin films processed by excimer laser irradiation

    SciTech Connect (OSTI)

    Van Overschelde, O. [Chimie des Interactions Plasma-Surface, Universite de Mons, 23, Place du Parc, 7000 Mons (Belgium); Delsate, T. [Service de Physique Theorique et Mathematique, Universite de Mons, 6 Avenue du champ de Mars, 7000 Mons (Belgium); Snyders, R. [Chimie des Interactions Plasma-Surface, Universite de Mons, 23, Place du Parc, 7000 Mons (Belgium); Materia Nova Research Center, 1 Avenue Copernic, 7000 Mons (Belgium)

    2012-06-15T23:59:59.000Z

    Processing surfaces by laser needs an understanding of the mechanisms generated by irradiation. In this work, to gain understanding of the mechanisms occurring during irradiation of TiO{sub 2} thin films by means of KrF excimer laser, we have performed infrared time resolved reflectivity measurements. This experimental investigation revealed modifications of the heating/cooling cycle as a function of the fluence (F). These modifications start appearing for a fluence value of about {approx}0.25 J/cm{sup 2} which is associated with the melting threshold of the film. Additionally, we have solved numerically the heat equation of the system with specific boundary conditions. From these calculations, we have established the thermal history of the film during the 25 ns irradiation pulse. The data reveal that a part of the medium liquefies around a fluence of 0.23 J/cm{sup 2} in good agreement with the experimental data.

  16. A Simple and Fast Iterative Soft-thresholding Algorithm for Tight Frames in Compressed Sensing Magnetic Resonance Imaging

    E-Print Network [OSTI]

    Liu, Yunsong; Cai, Jian-Feng; Guo, Di; Chen, Zhong; Qu, Xiaobo

    2015-01-01T23:59:59.000Z

    Compressed sensing has shown great potentials in accelerating magnetic resonance imaging. Fast image reconstruction and high image quality are two main issues faced by this new technology. It has been shown that, redundant image representations, e.g. tight frames, can significantly improve the image quality. But how to efficiently solve the reconstruction problem with these redundant representation systems is still challenging. This paper attempts to address the problem of applying fast iterative soft-thresholding algorithm (FISTA) to tight frames based magnetic resonance image reconstruction. By introducing the canonical dual frame, we construct an orthogonal projection operator on the range of the analysis sparsity operator and propose a new algorithm, called the projected FISTA (pFISTA). We theoretically prove that pFISTA converges to the minimum of a function with a balanced tight frame sparsity. One major advantage of pFISTA is that only one extra parameter, the step size, is introduced and the numerical...

  17. Measurement of 3pi^0 photoproduction on the proton from threshold to 1.4 GeV

    E-Print Network [OSTI]

    Starostin, A; Nefkens, B M K; Ahrens, J; Annand, J R M; Arends, H J; Bantawa, K; Bartolome, P A; Beck, R; Bekrenev, V; Braghieri, A; Branford, D; Briscoe, W J; Brudvik, J; Cherepnya, S; Dieterle, M; Downie, E J; Fil'kov, L V; Glazier, D I; Gregor, R; Heid, E; Hornidge, D; Jaegle, I; Jahn, O; Jude, T C; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J D; Manley, D M; Martinez, M; McGeorge, J C; McNicoll, E F; Metag, V; Mushkarenkov, A; Oberle, M; Ostrick, M; Pedroni, P; Polonski, A; Prakhov, S; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Sober, D; Supek, I; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Wertmueller, D; Witthauer, L

    2011-01-01T23:59:59.000Z

    The total cross section for gamma p -> 3pi0 p has been measured for the first time from threshold to 1.4 GeV using the tagged photon beam of the Mainz Microtron. The equipment utilized the Crystal Ball multiphoton spectrometer, the TAPS forward detector and a particle identification detector. The gamma p -> 3pi0 p total cross section has two broad enhancements at sqrt{s}~1.5 GeV and 1.7 GeV. We obtained the ratio of the total cross sections gamma p -> 3pi0 p to gamma p -> eta p equal to 0.014 \\pm 0.001 at sqrt{s}~1.5 GeV.

  18. Measurement of 3pi^0 photoproduction on the proton from threshold to 1.4 GeV

    E-Print Network [OSTI]

    A. Starostin; I. M. Suarez; B. M. K. Nefkens; J. Ahrens; J. R. M. Annand; H. J. Arends; K. Bantawa; P. A. Bartolome; R. Beck; V. Bekrenev; A. Braghieri; D. Branford; W. J. Briscoe; J. Brudvik; S. Cherepnya; M. Dieterle; E. J. Downie; L. V. Fil'kov; D. I. Glazier; R. Gregor; E. Heid; D. Hornidge; I. Jaegle; O. Jahn; T. C. Jude; V. L. Kashevarov; I. Keshelashvili; R. Kondratiev; M. Korolija; A. Koulbardis; S. Kruglov; B. Krusche; V. Lisin; K. Livingston; I. J. D. MacGregor; D. M. Manley; M. Martinez; J. C. McGeorge; E. F. McNicoll; V. Metag; A. Mushkarenkov; M. Oberle; M. Ostrick; P. Pedroni; A. Polonski; S. Prakhov; J. Robinson; G. Rosner; T. Rostomyan; S. Schumann; M. H. Sikora; D. Sober; I. Supek; M. Thiel; A. Thomas; M. Unverzagt; D. P. Watts; D. Wertmueller; L. Witthauer

    2011-01-19T23:59:59.000Z

    The total cross section for gamma p -> 3pi0 p has been measured for the first time from threshold to 1.4 GeV using the tagged photon beam of the Mainz Microtron. The equipment utilized the Crystal Ball multiphoton spectrometer, the TAPS forward detector and a particle identification detector. The gamma p -> 3pi0 p total cross section has two broad enhancements at sqrt{s}~1.5 GeV and 1.7 GeV. We obtained the ratio of the total cross sections gamma p -> 3pi0 p to gamma p -> eta p equal to 0.014 \\pm 0.001 at sqrt{s}~1.5 GeV.

  19. Threshold Photoelectron Photoion Coincidence (TPEPICO) Studies: The Road to ? 0.1 kJ/mol Thermochemistry

    SciTech Connect (OSTI)

    Baer, Tomas [University of North Carolina

    2013-10-14T23:59:59.000Z

    The threshold photoelectron photoion coincidence (TPEPICO) technique is utilized to investigate the dissociation dynamics and thermochemistry of energy selected medium to large organic molecular ions. The reactions include parallel and consecutive steps that are modeled with the statistical theory in order to extract dissociation onsets for multiple dissociation paths. These studies are carried out with the aid of molecular orbital calculations of both ions and the transition states connecting the ion structure to their products. The results of these investigations yield accurate heats of formation of ions, free radicals, and stable molecules. In addition, they provide information about the potential energy surface that governs the dissociation process. Isomerization reactions prior to dissociation are readily inferred from the TPEPICO data.

  20. Multiple colliding electromagnetic pulses: a way to lower the threshold of $e^+e^-$ pair production from vacuum

    E-Print Network [OSTI]

    S. S. Bulanov; V. D. Mur; N. B. Narozhny; J. Nees; V. S. Popov

    2010-03-12T23:59:59.000Z

    The scheme of simultaneous multiple pulse focusing on one spot naturally arises from the structural features of projected new laser systems, such as ELI and HiPER. It is shown that the multiple pulse configuration is beneficial for observing $e^+e^-$ pair production from vacuum under the action of sufficiently strong electromagnetic fields. The field of the focused pulses is described using a realistic three-dimensional model based on an exact solution of the Maxwell equations. The $e^+e^-$ pair production threshold in terms of electromagnetic field energy can be substantially lowered if, instead of one or even two colliding pulses, multiple pulses focused on one spot are used. The multiple pulse interaction geometry gives rise to subwavelength field features in the focal region. These features result in the production of extremely short $e^+e^-$ bunches.

  1. Axion Stars in the Infrared Limit

    E-Print Network [OSTI]

    Joshua Eby; Peter Suranyi; Cenalo Vaz; L. C. R. Wijewardhana

    2015-02-06T23:59:59.000Z

    Following Ruffini and Bonazzola, we use a quantized boson field to describe condensates of axions forming compact objects. Without substantial modifications, the method can only be applied to axions with decay constant, $f_a$, satisfying $\\delta=(f_a\\,/\\,M_P)^2\\ll 1$, where $M_P$ is the Planck mass. Similarly, the applicability of the Ruffini-Bonazzola method to axion stars also requires that the relative binding energy of axions satisfies $\\Delta=\\sqrt{1-(E_a\\,/\\,m_a)^2}\\ll1$, where $E_a$ and $m_a$ are the energy and mass of the axion. The simultaneous expansion of the equations of motion in $\\delta$ and $\\Delta$ leads to a simplified set of equations, depending only on the parameter, $\\lambda=\\sqrt{\\delta}\\,/\\,\\Delta$ in leading order of the expansions. Keeping leading order in $\\Delta$ is equivalent to the infrared limit, in which only relevant and marginal terms contribute to the equations of motion. The number of axions in the star is uniquely determined by $\\lambda$. Numerical solutions are found in a wide range of $\\lambda$. At small $\\lambda$ the mass and radius of the axion star rise linearly with $\\lambda$. While at larger $\\lambda$ the radius of the star continues to rise, the mass of the star, $M$, attains a maximum at $\\lambda_{\\rm max}\\simeq 0.58$. All stars are unstable for $\\lambda>\\lambda_{\\rm max}$ . We discuss the relationship of our results to current observational constraints on dark matter and the phenomenology of Fast Radio Bursts.

  2. Colloid-Associated Radionuclide Concentration Limits: ANL

    SciTech Connect (OSTI)

    C. Mertz

    2000-12-21T23:59:59.000Z

    The purpose and scope of this report is to describe the analysis of available colloidal data from waste form corrosion tests at Argonne National Laboratory (ANL) to extract characteristics of these colloids that can be used in modeling their contribution to the source term for sparingly soluble radioelements (e.g., Pu). Specifically, the focus is on developing a useful description of the following waste form colloid characteristics: (1) composition, (2) size distribution, and (3) quantification of the rate of waste form colloid generation. The composition and size distribution information are intended to support analysis of the potential transport of the sparingly soluble radionuclides associated with the waste form colloids. The rate of colloid generation is intended to support analysis of the waste form colloid-associated radionuclide concentrations. In addressing the above characteristics, available data are interpreted to address mechanisms controlling colloid formation and stability. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M&O 2000). Because the end objective is to support the source term modeling we have organized the conclusions into two categories: (1) data analysis conclusions and (2) recommendations for colloid source term modeling. The second category is included to facilitate use of the conclusions from the data analysis in the abstraction of a colloid source term model. The data analyses and conclusions that are presented in this report are based on small-scale laboratory tests conducted on a limited number of waste glass compositions and spent fuel types.

  3. Limited Electricity Generation Supply and Limited Natural Gas Supply Cases (released in AEO2008)

    Reports and Publications (EIA)

    2008-01-01T23:59:59.000Z

    Development of U.S. energy resources and the permitting and construction of large energy facilities have become increasingly difficult over the past 20 years, and they could become even more difficult in the future. Growing public concern about global warming and CO2 emissions also casts doubt on future consumption of fossil fuels -- particularly coal, which releases the largest amount of CO2 per unit of energy produced. Even without regulations to limit greenhouse gas emissions in the United States, the investment community may already be limiting the future use of some energy options. In addition, there is considerable uncertainty about the future availability of, and access to, both domestic and foreign natural gas resources.

  4. acid limitation induces: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wayne 2012-06-07 10 WAVE STRUCTURE INDUCED BY FLUID DYNAMIC LIMITS IN THE BROADWELL MODEL Mathematics Websites Summary: WAVE STRUCTURE INDUCED BY FLUID DYNAMIC LIMITS IN THE...

  5. Short communication Limits to deficit accumulation in elderly people

    E-Print Network [OSTI]

    Mitnitski, Arnold B.

    Short communication Limits to deficit accumulation in elderly people Kenneth Rockwood *, Arnold We evaluated limits to the accumulation of deficits (symptoms, diseases, disabilities) for 33 which, even in developed countries, further deficit accumulation is not sustainable. # 2006 Elsevier

  6. arctec canada limited: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and to define the contemporary limit of permafrost Moorman, Brian 8 Atomic Energy of Canada Limited CiteSeer Summary: CANDU natural uranium fuel is an outstanding product that...

  7. Overcoming the far-field diffraction limit via absorbance modulation

    E-Print Network [OSTI]

    Tsai, Hsin-Yu Sidney

    2011-01-01T23:59:59.000Z

    Diffraction limits the resolution of far-field lithography and imaging to about half of the wavelength, which greatly limits the capability of optical techniques. The proposed technique with absorbance modulation aims to ...

  8. The long wavelength limit of hard thermal loop effective actions

    E-Print Network [OSTI]

    F T Brandt; J Frenkel; J C Taylor

    2009-01-22T23:59:59.000Z

    We derive a closed form expression for the long wavelength limit of the effective action for hard thermal loops in an external gravitational field. It is a function of the metric, independent of time derivatives. It is compared and contrasted with the static limit, and with the corresponding limits in an external Yang-Mills field.

  9. Fertility Limits on Local Politicians in India Abhishek Chakravarty

    E-Print Network [OSTI]

    Bandyopadhyay, Antar

    .g., sterilization incentives in India). This paper examines a novel policy experiment that imposes fertility limitsFertility Limits on Local Politicians in India S Anukriti Abhishek Chakravarty September 19, 2014: political leaders. Keywords: India, Local Elections, Fertility Limits, Sex Ratios, Population Control We

  10. A Note on the Asymptotic Limit of the Four Simplex

    E-Print Network [OSTI]

    Suresh K Maran

    2005-11-05T23:59:59.000Z

    Recently the asymptotic limit of the Barrett-Crane models has been studied by Barrett and Steele. Here by a direct study, I show that we can extract the bivectors which satisfy the essential Barrett-Crane constraints from the asymptotic limit. Because of this the Schlaffi identity is implied by the asymptotic limit, rather than to be imposed as a constraint.

  11. Finding the Lower Stellar Mass Limit Observationally Justin Cantrell

    E-Print Network [OSTI]

    Wiita, Paul J.

    saying: "1. Objects with true masses below the limiting mass for thermonuclear fusion of deuterium masses above the limiting mass for thermonuclear fusion of deuterium are "brown dwarfs", no matter how below the limiting mass for thermonuclear fusion of deuterium are not "planets", but are "sub

  12. An alternative approach to achieving water quality-based limits

    SciTech Connect (OSTI)

    Hart, C.M.; Graeser, W.C.

    1995-12-01T23:59:59.000Z

    Since May 1982, members of the Iron and Steel Industry have been required to meet effluent limits based on Best Available Technology (BAT) for a process water discharge to receiving stream. US Steel Clairton Works has been successful in meeting these limits in the last three years; however, the current regulatory thrust is toward more stringent limits based on water quality. In cases of smaller streams such as the receiving stream for Clairton Works` process outfall, these limits can be very rigid. This paper will discuss the alternative approaches investigated to meet the new more stringent limits including the solution chosen.

  13. Repetitive petawatt-class laser with near-diffraction-limited focal spot and transform-limited pulse duration

    E-Print Network [OSTI]

    Umstadter, Donald

    Repetitive petawatt-class laser with near-diffraction-limited focal spot and transform-loop feedback control systems in the temporal and spatial domains are used to yield Fourier-transform acceleration and x-ray generation. Keywords: petawatt, diffraction limited, transform limited, spatial

  14. 1Design limits and solutions for very large wind turbines Design limits and solutions for very large wind turbines

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    #12;#12;1Design limits and solutions for very large wind turbines UpWind Design limits and solutions for very large wind turbines A 20 MW turbine is feasible March 2011 Supported by: #12;March 20112 Photo:Nordex #12;3Design limits and solutions for very large wind turbines Contents 1. UpWind: Summary

  15. Transition from ultrafast laser photo-electron emission to space charge limited current in a 1D gap

    E-Print Network [OSTI]

    Yangjie Liu; L. K. Ang

    2014-08-21T23:59:59.000Z

    A one-dimensional (1D) model has been constructed to study the transition of the time-dependent ultrafast laser photo-electron emission from a flat metallic surface to the space charge limited (SCL) current, including the effect of non-equilibrium laser heating on metals at the ultrafast time scale. At a high laser field, it is found that the space charge effect cannot be ignored and the SCL current emission is reached at a lower value predicted by a short pulse SCL current model that assumed a time-independent emission process. The threshold of the laser field to reach the SCL regime is determined over a wide range of operating parameters. The calculated results agree well with particle-in-cell (PIC) simulation. It is found that the space charge effect is more important for materials with lower work function like tungsten (4.4 eV) as compared to gold (5.4 eV). However for a flat surface, both materials will reach the space charge limited regime at the sufficiently high laser field such as $>$ 5 GV/m with a laser pulse length of tens to one hundred femtoseconds.

  16. Investigation of optical limiting properties of Aluminium nanoparticles prepared by pulsed laser ablation in different carrier media

    SciTech Connect (OSTI)

    Kuladeep, Rajamudili; Jyothi, L.; Narayana Rao, D. [School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)] [School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Prakash, P.; Mayank Shekhar, S. [Center of Excellence in Lasers and Optoelectronic Sciences, International School of Photonics, Cochin University of Science and Technology, Kochi (India)] [Center of Excellence in Lasers and Optoelectronic Sciences, International School of Photonics, Cochin University of Science and Technology, Kochi (India); Durga Prasad, M. [Center for Nanotechnology, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)] [Center for Nanotechnology, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)

    2013-12-28T23:59:59.000Z

    In this communication, we carried out the systematic investigation of nonlinear absorption and scattering properties of Aluminium nanoparticles (Al NPs) in various polar and non-polar solvents. Al NPs were synthesized with pulsed Nd:YAG laser operated at 1064 nm by ablating Al target in polar and non-polar liquid environment like chloroform, chlorobenzene, toluene, benzene, and carbon tetrachloride. Synthesized Al NPs colloids of various solvents differ in appearance and UV-Vis extinction spectra exhibit absorption in the UV region. The characterization of Al NPs performed by Transmission electron microscopy (TEM) studies reveal that NPs are made up of a well crystallized Al inner part (bright zone) embedded with an amorphous metal Al shell (dark region). Growth, aggregation, and precipitation mechanisms which influence the optical properties and stability of NPs are found to be related to the dipole moment of the surrounding liquid environment. The nonlinear absorption and scattering studies are performed by open aperture Z-scan technique with 532 nm under nanosecond pulse excitation. The Z-scan measurements are fitted theoretically to estimate both two-photon absorption (TPA) and nonlinear scattering (NLS) coefficients. In polar solvents like chlorobenzene, chloroform synthesized Al NPs exhibited higher TPA, NLS coefficient values, and lower optical limiting threshold values in comparison with partially polar solvent like toluene and non-polar solvents like benzene and carbontetrachloride. These results indicate the potential use of Al NPs as a versatile optical limiting material.

  17. Static and high-frequency hole transport in p-Si/SiGe heterostructures in the ultra-quantum limit.

    SciTech Connect (OSTI)

    Drichko, I. L.; Smirnov, I. Yu.; Suslov, A. V.; Galperin, Y. M.; Vinokur, V.; Myronov, M.; Mironov, O. A.; Materials Science Division; A.F. Ioffe Physico-Technical Inst. of Russian Academy of Sciences; National High Magnetic Field Lab.; Univ. Oslo; Musashi Inst. of Tech.; Univ. Warwick; International Lab. of High Magnetic Fields and Low Temperature

    2007-10-01T23:59:59.000Z

    Complex high-frequency (HF), {sigma}{sup AC} = {sigma}{sub 1} - i{sigma}{sub 2}, and static, {sigma}{sup DC}, conductivities, as well as current-voltage characteristics, have been measured in p-Si/SiGe heterostructures with a low hole density (p = 8.2 x 10{sup 10} cm{sup -2}) at temperatures T = 0.3-4.2 K in the ultraquantum limit, when the filling factor is v < 1. In order to determine the components of the HF conductivity, the acoustic contactless method in the 'hybrid configuration' is used, when the surface acoustic wave propagates on the surface of the LiNbO{sub 3} piezoelectric and the heterostructure is pressed to the surface by a spring. The conductivities {sigma}{sub 1} and {sigma}{sub 2} are determined from the damping and velocity of the surface acoustic waves that are measured simultaneously with varying the magnetic field. The revealed HF conductivity features - {sigma}{sub 1} >> |{sigma}{sub 2}|, the negative sign of {sigma}{sub 2}, the threshold behavior of the current-voltage characteristic, and the dependence I {proportional_to} exp(-A/V{sup 0.3}) in the subthreshold region - indicate the formation of a pinned Wigner crystal (glass) in the ultraquantum limit (T = 0.3-0.8 K, B > 14 T).

  18. Parametrization of gamma-ray production cross-sections for pp interactions in a broad proton energy range from the kinematic threshold to PeV energies

    E-Print Network [OSTI]

    Ervin Kafexhiu; Felix Aharonian; Andrew M. Taylor; Gabriela S. Vila

    2014-07-05T23:59:59.000Z

    Using publicly available Monte Carlo codes as well as compilation of published data on p--p interactions for proton kinetic energy below 2 GeV, we parametrize the energy spectra and production rates of $\\gamma$-rays by simple but quite accurate ($\\leq 20 \\%$) analytical expressions in a broad range from the kinematic threshold to PeV energies.

  19. Evidence for a Narrow Near-Threshold Structure in the J/ psi phi Mass Spectrum in B+-->J/ psi phi K+ Decays

    E-Print Network [OSTI]

    Xie, Si

    Evidence is reported for a narrow structure near the J/?? threshold in exclusive B+?J/??K+ decays produced in (p)over-bar p collisions at ?s=1.96??TeV. A signal of 14±5 events, with statistical significance in excess of ...

  20. Optical Nonlinearity in Ar and N2 near the Ionization Threshold J. K. Wahlstrand, Y.-H. Cheng, Y.-H. Chen, and H. M. Milchberg

    E-Print Network [OSTI]

    Milchberg, Howard

    Optical Nonlinearity in Ar and N2 near the Ionization Threshold J. K. Wahlstrand, Y.-H. Cheng, Y measure the nonlinear optical response in argon and nitrogen in a thin gas target to laser intensities.103901 PACS numbers: 42.65.An, 42.65.Jx, 42.65.Re The optical Kerr effect, the intensity-dependent refrac