Sample records for layered bispectral threshold

  1. Some Noncommutative Matrix Algebras Arising in the Bispectral Problem

    E-Print Network [OSTI]

    F. Alberto Grünbaum

    2014-07-24T23:59:59.000Z

    I revisit the so called "bispectral problem" introduced in a joint paper with Hans Duistermaat a long time ago, allowing now for the differential operators to have matrix coefficients and for the eigenfunctions, and one of the eigenvalues, to be matrix valued too. In the last example we go beyond this and allow both eigenvalues to be matrix valued.

  2. Performance evaluation of Threshold-based Multi-layer Traffic Engineering

    E-Print Network [OSTI]

    López, Víctor

    at the IP layer [2]. This way, the optical layer may be used to reduce the CAPEX and OPEX requirements

  3. Bispectral-Based Methods for Clustering Time Series Jane L. Harvill

    E-Print Network [OSTI]

    Ravishanker, Nalini

    the ratios. As an example, we apply the method to a set of time series of intensities of gamma-ray bursts, some of which exhibit nonlinear behavior; this enables us to identify gamma-ray bursts that may. As an example, we apply the bispectral-based clustering technique to a set of gamma-ray burst (GRB) intensity

  4. Current-induced electrical self-oscillations across out-of-plane threshold switches based on VO{sub 2} layers integrated in crossbars geometry

    SciTech Connect (OSTI)

    Beaumont, A.; Leroy, J.; Crunteanu, A., E-mail: aurelian.crunteanu@xlim.fr [XLIM Research Institute UMR 7252, CNRS/University of Limoges, 123 avenue Albert Thomas, 87060 Limoges (France); Orlianges, J.-C. [SPCTS UMR 7513, CNRS/University of Limoges, 12 rue Atlantis, 87068 Limoges (France)

    2014-04-21T23:59:59.000Z

    Electrically activated metal-insulator transition (MIT) in vanadium dioxide (VO{sub 2}) is widely studied from both fundamental and practical points of view. It can give valuable insights on the currently controversial phase transition mechanism in this material and, at the same time, allows the development of original MIT-based electronic devices. Electrically triggered insulator-metal transitions are demonstrated in novel out-of-plane, metal-oxide-metal type devices integrating a VO{sub 2} thin film, upon applying moderate threshold voltages. It is shown that the current-voltage characteristics of such devices present clear negative differential resistance effects supporting the onset of continuous, current-driven phase oscillations across the vanadium dioxide material. The frequencies of these self-sustained oscillations are ranging from 90 to 300?kHz and they may be tuned by adjusting the injected current. A phenomenological model of the device and its command circuit is developed, and allows to extract the analytical expressions of the oscillation frequencies and to simulate the electrical oscillatory phenomena developed across the VO{sub 2} material. Such out-of-plane devices may further contribute to the general understanding of the driving mechanism in metal-insulator transition materials and devices, a prerequisite to promising applications in high speed/high frequency networks of oscillatory or resistive memories circuits.

  5. 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.

  6. 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.

  7. 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...

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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 ...

  17. 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.

  18. Optical testing of layered microstructures with and without underlying vias.

    SciTech Connect (OSTI)

    Serrano, Justin Raymond; Phinney, Leslie Mary

    2006-02-01T23:59:59.000Z

    The response of microsystem components to laser irradiation is relevant to the use of laser processing, optical diagnostics, and optical microelectromechanical systems (MEMS) device design and performance. The dimensions of MEMS are on the same order as infrared laser wavelengths which results in interference phenomena when the parts are partially transparent. Four distinct polycrystalline structures were designed and irradiated with 808 nm laser light to determine the effect of layers and the presence of a substrate via on the laser power threshold for damage. The presence of a substrate via resulted in lower damage thresholds, and interference phenomena resulted in a single layer structure having the highest damage threshold.

  19. 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).

  20. 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...

  1. 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...

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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 ...

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  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. High-power, very low threshold, GaImnP/AIGaInP visble-diode lasers l-l. B. Serreze, v. C. Chen, and R. 6. Waters

    E-Print Network [OSTI]

    lasers,and this cw threshold current density is believedto be, by far, the lowest. Low-power visibleHigh-power, very low threshold, GaImnP/AIGaInP visble-diode lasers l-l. B. Serreze, v. C. Chen light (665 nm) laser diodesemploying a strained-layer,single quantum well, graded index

  20. Multilayered gold/silica nanoparticulate bilayer devices using layer-by-layer self organisation for flexible bending and pressure sensing applications

    SciTech Connect (OSTI)

    Shah Alam, Md. [Department of Electrical and Electronic Engineering, Rajshahi University of Engineering and Technology, Rajshahi 6204 (Bangladesh); Center of Excellence in Nanotechnology, Asian Institute of Technology, 12120 Pathumthani (Thailand); Mohammed, Waleed S., E-mail: waleed.m@bu.ac.th [Center of Research in Optoelectronics, Communication and Control System (BU-CROCCS), School of Engineering, Bangkok University, Pathumthani 12120 (Thailand); Dutta, Joydeep, E-mail: dutta@squ.edu.om [Center of Excellence in Nanotechnology, Asian Institute of Technology, 12120 Pathumthani (Thailand); Chair in Nanotechnology, Water Research Center, Sultan Qaboos University, P.O. Box 33, Al Khoud 123 (Oman)

    2014-02-17T23:59:59.000Z

    A pressure and bending sensor was fabricated using multilayer thin films fabricated on a flexible substrate based on layer-by-layer self-organization of 18?nm gold nanoparticles separated by a dielectric layer of 30?nm silica nanoparticles. 50, 75, and 100 gold-silica bi-layered films were deposited and the device characteristics were studied. A threshold voltage was required for electron conduction which increases from 2.4?V for 50 bi-layers to 3.3?V for 100 bi-layers. Upon bending of the device up to about 52°, the threshold voltage and slope of the I-V curves change linearly. Electrical characterization of the multilayer films was carried out under ambient conditions with different pressures and bending angles in the direct current mode. This study demonstrates that the developed multilayer thin films can be used as pressure as well as bending sensing applications.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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...

  9. 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.

  10. Photonic layered media

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A new class of structured dielectric media which exhibit significant photonic bandstructure has been invented. The new structures, called photonic layered media, are easy to fabricate using existing layer-by-layer growth techniques, and offer the ability to significantly extend our practical ability to tailor the properties of such optical materials.

  11. 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.

  12. 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.

  13. 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.

  14. High Efficiency Oxide-Confined High-Index-Contrast Broad-Area Lasers with Reduced Threshold Current Density and Improved Near-Field Profile

    E-Print Network [OSTI]

    Bowers, John

    High Efficiency Oxide-Confined High-Index-Contrast Broad-Area Lasers with Reduced Threshold Current. The poor lateral electrical and optical confinement, however, make current spreading unavoidable and lead), followed by non-selective O2-enhanced wet thermal oxidation [2] to grow a uniform thickness layer of high

  15. 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...

  16. 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 ...

  17. Layered plasma polymer composite membranes

    DOE Patents [OSTI]

    Babcock, W.C.

    1994-10-11T23:59:59.000Z

    Layered plasma polymer composite fluid separation membranes are disclosed, which comprise alternating selective and permeable layers for a total of at least 2n layers, where n is [>=]2 and is the number of selective layers. 2 figs.

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. Layered Cathode Materials

    Broader source: Energy.gov (indexed) [DOE]

    Layered Cathode Materials presented by Michael Thackeray Chemical Sciences and Engineering Division, Argonne Annual Merit Review DOE Vehicle Technologies Program Washington, D.C....

  4. Layering as Optimization Decomposition 3-1 Layering as OptimizationLayering as Optimization

    E-Print Network [OSTI]

    Fan, Xingzhe

    1 Layering as Optimization Decomposition 3-1 Layering as OptimizationLayering as Optimization DecompositionDecomposition Layering as Optimization Decomposition 3-2 CONTENTSCONTENTS Introduction (Marta;2 Layering as Optimization Decomposition 3-3 Layering as Optimization Decomposition Introduction By Marta

  5. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, Terry W. (Tracy, CA)

    1994-01-01T23:59:59.000Z

    A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

  6. Multiple density layered insulator

    DOE Patents [OSTI]

    Alger, T.W.

    1994-09-06T23:59:59.000Z

    A multiple density layered insulator for use with a laser is disclosed which provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation. 4 figs.

  7. Multiple layer insulation cover

    DOE Patents [OSTI]

    Farrell, James J. (Livingston Manor, NY); Donohoe, Anthony J. (Ovid, NY)

    1981-11-03T23:59:59.000Z

    A multiple layer insulation cover for preventing heat loss in, for example, a greenhouse, is disclosed. The cover is comprised of spaced layers of thin foil covered fabric separated from each other by air spaces. The spacing is accomplished by the inflation of spaced air bladders which are integrally formed in the cover and to which the layers of the cover are secured. The bladders are inflated after the cover has been deployed in its intended use to separate the layers of the foil material. The sizes of the material layers are selected to compensate for sagging across the width of the cover so that the desired spacing is uniformly maintained when the cover has been deployed. The bladders are deflated as the cover is stored thereby expediting the storage process and reducing the amount of storage space required.

  8. Damage of multilayer optics with varying capping layers induced by focused extreme ultraviolet beam

    SciTech Connect (OSTI)

    Jody Corso, Alain; Nicolosi, Piergiorgio; Nardello, Marco; Guglielmina Pelizzo, Maria [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy) [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy); Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova (Italy); Zuppella, Paola [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy)] [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy); Barkusky, Frank [Laser-Laboratorium Goettingen e.V, Goettingen (Germany) [Laser-Laboratorium Goettingen e.V, Goettingen (Germany); KLA-Tencor, 5 Technology Dr., Milpitas, California 95035 (United States); Mann, Klaus; Mueller, Matthias [Laser-Laboratorium Goettingen e.V, Goettingen (Germany)] [Laser-Laboratorium Goettingen e.V, Goettingen (Germany)

    2013-05-28T23:59:59.000Z

    Extreme ultraviolet Mo/Si multilayers protected by capping layers of different materials were exposed to 13.5 nm plasma source radiation generated with a table-top laser to study the irradiation damage mechanism. Morphology of single-shot damaged areas has been analyzed by means of atomic force microscopy. Threshold fluences were evaluated for each type of sample in order to determine the capability of the capping layer to protect the structure underneath.

  9. Compliant layer chucking surface

    DOE Patents [OSTI]

    Blaedel, Kenneth L. (Dublin, CA); Spence, Paul A. (Pleasanton, CA); Thompson, Samuel L. (Pleasanton, CA)

    2004-12-28T23:59:59.000Z

    A method and apparatus are described wherein a thin layer of complaint material is deposited on the surface of a chuck to mitigate the deformation that an entrapped particle might cause in the part, such as a mask or a wafer, that is clamped to the chuck. The harder particle will embed into the softer layer as the clamping pressure is applied. The material composing the thin layer could be a metal or a polymer for vacuum or electrostatic chucks. It may be deposited in various patterns to affect an interrupted surface, such as that of a "pin" chuck, thereby reducing the probability of entrapping a particle.

  10. A new cloud and aerosol layer detection method based on micropulse lidar measurements

    E-Print Network [OSTI]

    Li, Zhanqing

    A new cloud and aerosol layer detection method based on micropulse lidar measurements Chuanfeng algorithm to detect aerosols and clouds based on micropulse lidar measurements. A semidiscretization is then introduced. Combined with empirical threshold values, we determine if the signal waves indicate clouds

  11. 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. ...

  12. 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

  13. 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

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. Layered Spinach Salad Ingredients

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    cucumbers 2 tomatoes 1/2 cup low-fat mayonnaise 1/2 cup parmesan cheese, grated 1/4 cup milk 1 1/2 teaspoons size pieces, layer on bottom of a large bowl. 2. Rinse mushrooms off under cool water and use a soft half. Layer on top of vegetables. 6. To make salad dressing, add mayonnaise, cheese, milk, dill weed

  19. Structured luminescence conversion layer

    DOE Patents [OSTI]

    Berben, Dirk; Antoniadis, Homer; Jermann, Frank; Krummacher, Benjamin Claus; Von Malm, Norwin; Zachau, Martin

    2012-12-11T23:59:59.000Z

    An apparatus device such as a light source is disclosed which has an OLED device and a structured luminescence conversion layer deposited on the substrate or transparent electrode of said OLED device and on the exterior of said OLED device. The structured luminescence conversion layer contains regions such as color-changing and non-color-changing regions with particular shapes arranged in a particular pattern.

  20. 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 ...

  1. 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.

  2. 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.

  3. 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.

  4. Layered semiconductor neutron detectors

    DOE Patents [OSTI]

    Mao, Samuel S; Perry, Dale L

    2013-12-10T23:59:59.000Z

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  5. 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

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    SciTech Connect (OSTI)

    El-Atab, Nazek; Rizk, Ayman; Nayfeh, Ammar [Institute Center for Microsystems – iMicro, Department of Electrical Engineering and Computer Science (EECS), Masdar Institute of Science and Technology Abu Dhabi (United Arab Emirates)] [Institute Center for Microsystems – iMicro, Department of Electrical Engineering and Computer Science (EECS), Masdar Institute of Science and Technology Abu Dhabi (United Arab Emirates); Okyay, Ali K. [Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey) [Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey); UNAM-National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

    2013-11-15T23:59:59.000Z

    A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO{sub 2} layer is deposited between Atomic Layer Deposition (ALD) steps. A threshold voltage (V{sub t}) shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V V{sub t} shift, the memory with CrO{sub 2} layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO{sub 2} layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  18. Layer-by-layer assembly in confined geometries

    E-Print Network [OSTI]

    DeRocher, Jonathan P

    2011-01-01T23:59:59.000Z

    The fundamental nature of layer-by-layer (LbL) assembly in confined geometries was investigated for a number of different chemical systems. The first part of this thesis concerns the modification of microfluidic and ...

  19. Ion transport and structure of layer-by-layer assemblies

    E-Print Network [OSTI]

    Lutkenhaus, Jodie Lee

    2007-01-01T23:59:59.000Z

    Layer-by-layer (LbL) films of various architectures were examined as potential solid state electrolytes for electrochemical systems (e.g. batteries and fuel cells). The relationship between materials properties and ion ...

  20. Thermal Transitions in Layer-By-Layer Assemblies

    E-Print Network [OSTI]

    Sung, Choonghyun

    2014-10-13T23:59:59.000Z

    Thermal transitions in layer-by-layer (LbL) assemblies were investigated under dry and hydrated conditions. In the dry state, the effects of film thickness and the film deposition method on the glass transition temperature (Tg) were studied...

  1. Engineering electroresponsive layer-by-layer thin films

    E-Print Network [OSTI]

    Schmidt, Daniel J., Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Electroresponsive layer-by-layer (LbL) polymer films and polymer nanocomposite films were investigated as model systems for electrically triggered drug delivery applications and "mechanomutable" surface coating applications. ...

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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...

  9. 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

  10. 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

  11. “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...

  12. Metal deposition using seed layers

    DOE Patents [OSTI]

    Feng, Hsein-Ping; Chen, Gang; Bo, Yu; Ren, Zhifeng; Chen, Shuo; Poudel, Bed

    2013-11-12T23:59:59.000Z

    Methods of forming a conductive metal layers on substrates are disclosed which employ a seed layer to enhance bonding, especially to smooth, low-roughness or hydrophobic substrates. In one aspect of the invention, the seed layer can be formed by applying nanoparticles onto a surface of the substrate; and the metallization is achieved by electroplating an electrically conducting metal onto the seed layer, whereby the nanoparticles serve as nucleation sites for metal deposition. In another approach, the seed layer can be formed by a self-assembling linker material, such as a sulfur-containing silane material.

  13. Buried oxide layer in silicon

    DOE Patents [OSTI]

    Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir, TN)

    2001-01-01T23:59:59.000Z

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  14. 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.

  15. 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.

  16. 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 %.

  17. 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.

  18. 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.

  19. 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.

  20. 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 ...

  1. 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.

  2. 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.

  3. Double-layer ion acceleration triggered by ion magnetization in expanding radiofrequency plasma sources

    SciTech Connect (OSTI)

    Takahashi, Kazunori [Department of Electrical and Electronic Engineering, Iwate University, Morioka 020-8551 (Japan); Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra 0200 (Australia); Charles, Christine; Boswell, Rod W. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra 0200 (Australia); Fujiwara, Tamiya [Department of Electrical and Electronic Engineering, Iwate University, Morioka 020-8551 (Japan)

    2010-10-04T23:59:59.000Z

    Ion energy distribution functions downstream of the source exit in magnetically expanding low-pressure plasmas are experimentally investigated for four source tube diameters ranging from about 5 to 15 cm. The magnetic-field threshold corresponding to a transition from a simple expanding plasma to a double layer-containing plasma is observed to increase with a decrease in the source tube diameter. The results demonstrate that for the four geometries, the double layer and the accelerated ion beam form when the ion Larmour radius in the source becomes smaller than the source tube radius, i.e., when the ions become magnetized in the source tube.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  9. Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization Artificial Neural Networks

    E-Print Network [OSTI]

    Kjellström, Hedvig

    Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization Artificial Neural Networks Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization 1 Artificial Neural Networks Properties Applications Classical Examples Biological Background 2 Single Layer

  10. Oxygen-reducing catalyst layer

    DOE Patents [OSTI]

    O'Brien, Dennis P. (Maplewood, MN); Schmoeckel, Alison K. (Stillwater, MN); Vernstrom, George D. (Cottage Grove, MN); Atanasoski, Radoslav (Edina, MN); Wood, Thomas E. (Stillwater, MN); Yang, Ruizhi (Halifax, CA); Easton, E. Bradley (Halifax, CA); Dahn, Jeffrey R. (Hubley, CA); O'Neill, David G. (Lake Elmo, MN)

    2011-03-22T23:59:59.000Z

    An oxygen-reducing catalyst layer, and a method of making the oxygen-reducing catalyst layer, where the oxygen-reducing catalyst layer includes a catalytic material film disposed on a substrate with the use of physical vapor deposition and thermal treatment. The catalytic material film includes a transition metal that is substantially free of platinum. At least one of the physical vapor deposition and the thermal treatment is performed in a processing environment comprising a nitrogen-containing gas.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Network layer Connectionless datagram forwarding

    E-Print Network [OSTI]

    (passed down by transport layer) into datagrams Destination host delivers segments up to transport layer by the cold war " If there exists a path, routers will put it in the routing table automatically Forwarding in the original order Physical Link Network Transport Application Physical Link Network Transport Application

  19. 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.

  20. 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}.

  1. $J/?$ 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.

  2. 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.

  3. D0 layer 0 innermost layer of silicon microstrip tracker

    SciTech Connect (OSTI)

    Hanagaki, K.; /Fermilab

    2006-01-01T23:59:59.000Z

    A new inner layer silicon strip detector has been built and will be installed in the existing silicon microstrip tracker in D0. They report on the motivation, design, and performance of this new detector.

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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}}.

  10. 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.

  11. METEOROLOGY 130 Boundary Layer Meteorology

    E-Print Network [OSTI]

    Clements, Craig

    4) Turbulence Kinetic Energy · TKE budget and terms · Stability concepts · Richardson number 5) Measuring the Boundary Layer · Balloons · Radars · Sodars · Towers (micrometeorology) · Measuring Turbulence Time Series Analysis 8) Similarity Theory and Turbulence Closure 9) Surface Energy Budgets 10) Special

  12. THE MARTIAN ATMOSPHERIC BOUNDARY LAYER

    E-Print Network [OSTI]

    Spiga, Aymeric

    THE MARTIAN ATMOSPHERIC BOUNDARY LAYER A. Petrosyan,1 B. Galperin,2 S. E. Larsen,3 S. R. Lewis,4 A [Haberle et al., 1993a; Larsen et al., 2002; Hinson et al., 2008]. At night, convection is inhibited

  13. General Comparison of Power Loss in Single-Layer and Multi-Layer Windings

    E-Print Network [OSTI]

    General Comparison of Power Loss in Single-Layer and Multi-Layer Windings M. E. Dale C. R. Sullivan the IEEE. #12;General Comparison of Power Loss in Single-Layer and Multi-Layer Windings Magdalena E. Dale

  14. Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization Artificial Neural Networks

    E-Print Network [OSTI]

    Kjellström, Hedvig

    Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization Artificial Neural Networks #12;Artificial Neural Networks Single Layer Networks Multi Layer Networks Generalization 1 Artificial Neural Networks Properties Applications Classical Examples Biological Background 2

  15. 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.

  16. 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}.

  17. Fabrication of silica aerogel with $n$ = 1.08 for $e^+/?^+$ separation in a threshold Cherenkov counter of the J-PARC TREK/E36 experiment

    E-Print Network [OSTI]

    Makoto Tabata; Akihisa Toyoda; Hideyuki Kawai; Youichi Igarashi; Jun Imazato; Suguru Shimizu; Hirohito Yamazaki

    2015-06-09T23:59:59.000Z

    This study presents the development of hydrophobic silica aerogel for use as a radiator in threshold-type Cherenkov counters. These counters are to be used for separating positrons and positive muons produced by kaon decay in the J-PARC TREK/E36 experiment. We chose to employ aerogel with a refractive index of 1.08 to identify charged particles with momenta of approximately 240 MeV/$c$, and the radiator block shape was designed with a trapezoidal cross-section to fit the barrel region surrounding the kaon stopping target in the center of the TREK/E36 detector system. Including spares, we obtained 30 crack-free aerogel blocks segmented into two layers, each layer having a thickness of 2 cm and a length of 18 cm, to fill 12 counter modules. Optical measurements showed that the produced aerogel tiles had the required refractive indices and transparency.

  18. Hybrid window layer for photovoltaic cells

    DOE Patents [OSTI]

    Deng, Xunming (Syvania, OH)

    2010-02-23T23:59:59.000Z

    A novel photovoltaic solar cell and method of making the same are disclosed. The solar cell includes: at least one absorber layer which could either be a lightly doped layer or an undoped layer, and at least a doped window-layers which comprise at least two sub-window-layers. The first sub-window-layer, which is next to the absorber-layer, is deposited to form desirable junction with the absorber-layer. The second sub-window-layer, which is next to the first sub-window-layer, but not in direct contact with the absorber-layer, is deposited in order to have transmission higher than the first-sub-window-layer.

  19. The limited growth of vegetated shear layers

    E-Print Network [OSTI]

    Ghisalberti, M.

    In contrast to free shear layers, which grow continuously downstream, shear layers generated by submerged vegetation grow only to a finite thickness. Because these shear layers are characterized by coherent vortex structures ...

  20. Hybrid window layer for photovoltaic cells

    DOE Patents [OSTI]

    Deng, Xunming (Syvania, OH); Liao, Xianbo (Toledo, OH); Du, Wenhui (Toledo, OH)

    2011-10-04T23:59:59.000Z

    A novel photovoltaic solar cell and method of making the same are disclosed. The solar cell includes: at least one absorber layer which could either be a lightly doped layer or an undoped layer, and at least a doped window-layers which comprise at least two sub-window-layers. The first sub-window-layer, which is next to the absorber-layer, is deposited to form desirable junction with the absorber-layer. The second sub-window-layer, which is next to the first sub-window-layer, but not in direct contact with the absorber-layer, is deposited in order to have transmission higher than the first-sub-window-layer.

  1. Hybrid window layer for photovoltaic cells

    DOE Patents [OSTI]

    Deng, Xunming (Sylvania, OH); Liao, Xianbo (Toledo, OH); Du, Wenhui (Toledo, OH)

    2011-02-01T23:59:59.000Z

    A novel photovoltaic solar cell and method of making the same are disclosed. The solar cell includes: at least one absorber layer which could either be a lightly doped layer or an undoped layer, and at least a doped window-layers which comprise at least two sub-window-layers. The first sub-window-layer, which is next to the absorber-layer, is deposited to form desirable junction with the absorber-layer. The second sub-window-layer, which is next to the first sub-window-layer, but not in direct contact with the absorber-layer, is deposited in order to have transmission higher than the first-sub-window-layer.

  2. 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.

  3. 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.

  4. A preliminary evaluation of a speed threshold incident detection algorithm

    E-Print Network [OSTI]

    Kolb, Stephanie Lang

    1996-01-01T23:59:59.000Z

    Algorithm . . . . . . . . . . . . , . Event Scan Algorithm . Neural Network . . . . . . . . . . . . . . . , . . . . . . California Algorithm ?8 with Fuzzy Logic Selected Algorithms Page 20 21 22 24 24 25 26 27 28 28 30 32 32 33 33 33 33... 7 California Algorithm ?10 Decision Tree 12 14 15 8 Speed/Flow Curve 9 McMaster Algorithm Template 15 25 10 Traffic Flow Relationships Applied in the Dynamic Model Algorithm. . . 26 11 Multi-Layer Feed-Forward Neural Network 12 Membership...

  5. The Announcement Layer: Beacon Coordination for the Sensornet Stack

    E-Print Network [OSTI]

    Dunkels, Adam

    consumption. #12;MAC / Link layers ... ... Multiple, uncoordinated beacons Collect Trickle Deluge Collect Trickle Deluge Coordinated beacons Announcement layer MAC / Link layers Fig. 1. The announcement layer

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 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...

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. Layered architecture for quantum computing

    E-Print Network [OSTI]

    N. Cody Jones; Rodney Van Meter; Austin G. Fowler; Peter L. McMahon; Jungsang Kim; Thaddeus D. Ladd; Yoshihisa Yamamoto

    2012-09-27T23:59:59.000Z

    We develop a layered quantum computer architecture, which is a systematic framework for tackling the individual challenges of developing a quantum computer while constructing a cohesive device design. We discuss many of the prominent techniques for implementing circuit-model quantum computing and introduce several new methods, with an emphasis on employing surface code quantum error correction. In doing so, we propose a new quantum computer architecture based on optical control of quantum dots. The timescales of physical hardware operations and logical, error-corrected quantum gates differ by several orders of magnitude. By dividing functionality into layers, we can design and analyze subsystems independently, demonstrating the value of our layered architectural approach. Using this concrete hardware platform, we provide resource analysis for executing fault-tolerant quantum algorithms for integer factoring and quantum simulation, finding that the quantum dot architecture we study could solve such problems on the timescale of days.

  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. Tail-ion transport and Knudsen layer formation in the presence of magnetic fields

    SciTech Connect (OSTI)

    Schmit, P. F. [Sandia National Laboratories, MS 1186, P.O. Box 5800, Albuquerque, New Mexico 87185-1186 (United States)] [Sandia National Laboratories, MS 1186, P.O. Box 5800, Albuquerque, New Mexico 87185-1186 (United States); Molvig, Kim; Nakhleh, C. W. [Los Alamos National Laboratory, MS B259, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, MS B259, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)

    2013-11-15T23:59:59.000Z

    Knudsen layer losses of tail fuel ions could reduce significantly the fusion reactivity of highly compressed cylindrical and spherical targets in inertial confinement fusion (ICF). With the class of magnetized ICF targets in mind, the effect of embedded magnetic fields on Knudsen layer formation is investigated for the first time. The modified energy scaling of ion diffusivity in magnetized hot spots is found to suppress the preferential losses of tail-ions perpendicular to the magnetic field lines to a degree that the tail distribution can be at least partially, if not fully, restored. Two simple threshold conditions are identified leading to the restoration of fusion reactivity in magnetized hot spots. A kinetic equation for tail-ion transport in the presence of a magnetic field is derived, and solutions to the equation are obtained numerically in simulations. Numerical results confirm the validity of the threshold conditions for restored reactivity and identify two different asymptotic regimes of the fusion fuel. While Knudsen layer formation is shown to be suppressed entirely in strongly magnetized cylindrical hot spot cavities, uniformly magnetized spherical cavities demonstrate remnant, albeit reduced, levels of tail-ion depletion.

  6. Layered Manufacturing Sara McMains

    E-Print Network [OSTI]

    McMains, Sara

    ­ Sintering (vector) ­ 3D Printing (raster) #12;Stereolithography (SLA) · First commercial layered

  7. Buffer layer for thin film structures

    DOE Patents [OSTI]

    Foltyn, Stephen R.; Jia, Quanxi; Arendt, Paul N.; Wang, Haiyan

    2010-06-15T23:59:59.000Z

    A composite structure including a base substrate and a layer of a mixture of strontium titanate and strontium ruthenate is provided. A superconducting article can include a composite structure including an outermost layer of magnesium oxide, a buffer layer of strontium titanate or a mixture of strontium titanate and strontium ruthenate and a top-layer of a superconducting material such as YBCO upon the buffer layer.

  8. Buffer layer for thin film structures

    DOE Patents [OSTI]

    Foltyn, Stephen R.; Jia, Quanxi; Arendt, Paul N.; Wang, Haiyan

    2006-10-31T23:59:59.000Z

    A composite structure including a base substrate and a layer of a mixture of strontium titanate and strontium ruthenate is provided. A superconducting article can include a composite structure including an outermost layer of magnesium oxide, a buffer layer of strontium titanate or a mixture of strontium titanate and strontium ruthenate and a top-layer of a superconducting material such as YBCO upon the buffer layer.

  9. Chemical solution seed layer for rabits tapes

    SciTech Connect (OSTI)

    Goyal, Amit; Paranthaman, Mariappan; Wee, Sung-Hun

    2014-06-10T23:59:59.000Z

    A method for making a superconducting article includes the steps of providing a biaxially textured substrate. A seed layer is then deposited. The seed layer includes a double perovskite of the formula A.sub.2B'B''O.sub.6, where A is rare earth or alkaline earth metal and B' and B'' are different rare earth or transition metal cations. A superconductor layer is grown epitaxially such that the superconductor layer is supported by the seed layer.

  10. 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.

  11. Sensitivity of TOMS aerosol index to boundary layer height: Implications for detection of mineral aerosol sources

    E-Print Network [OSTI]

    Mahowald, Natalie

    (using a threshold of 0.7, except over North Africa, the Middle East and Central Asia where the threshold

  12. 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 ...

  13. 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

  14. Interface dynamics for layered structures

    E-Print Network [OSTI]

    Takao Ohta; David Jasnow

    1997-07-17T23:59:59.000Z

    We investigate dynamics of large scale and slow deformations of layered structures. Starting from the respective model equations for a non-conserved system, a conserved system and a binary fluid, we derive the interface equations which are a coupled set of equations for deformations of the boundaries of each domain. A further reduction of the degrees of freedom is possible for a non-conserved system such that internal motion of each domain is adiabatically eliminated. The resulting equation of motion contains only the displacement of the center of gravity of domains, which is equivalent to the phase variable of a periodic structure. Thus our formulation automatically includes the phase dynamics of layered structures. In a conserved system and a binary fluid, however, the internal motion of domains turns out to be a slow variable in the long wavelength limit because of concentration conservation. Therefore a reduced description only involving the phase variable is not generally justified.

  15. Electronic transport in atomically thin layered materials

    E-Print Network [OSTI]

    Baugher, Britton William Herbert

    2014-01-01T23:59:59.000Z

    Electronic transport in atomically thin layered materials has been a burgeoning field of study since the discovery of isolated single layer graphene in 2004. Graphene, a semi-metal, has a unique gapless Dirac-like band ...

  16. 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

  17. 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...

  18. $pp\\to pp?^0$ 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.

  19. 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

  20. 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...

  1. 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 ...

  2. 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

  3. Physical layer model design for wireless networks 

    E-Print Network [OSTI]

    Yu, Yi

    2009-06-02T23:59:59.000Z

    the relationship between wireless protocol design and physical layer models, it is necessary to first comprehend the network architecture, which groups the communication functions into related and manageable layers. The journal model is IEEE Transactions... data to the network format and vice versa. It is intended to provide independence from different represen- tations of application layer data. The session layer deals with sessions and connections between applications. It manages conversations between...

  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. 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.

  6. 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.

  7. Driving toroidally asymmetric current through the tokamak scrape-off layer, Part I: Potential for ELM suppression

    SciTech Connect (OSTI)

    Joseph, I; Cohen, R H; Ryutov, D D

    2009-03-31T23:59:59.000Z

    A potential technique for suppressing edge localized magnetohydrodynamic instabilities (ELMs) is theoretically analyzed. Recent experiments have shown that externally generated resonant magnetic perturbations (RMPs) can stabilize ELMs by modifying the density profile [T. E. Evans, et al., Nature Phys. 2, 419 (2006); Y. Liang, et al., Phys. Rev. Lett. 98, 265004 (2007)]. Driving toroidally asymmetric current internally, through the scrape-off layer (SOL) plasma itself, can also generate RMPs that are close to the required threshold for ELM control. The limiting ion saturation current densities can be achieved by producing potential differences on the order of the electron temperature. Although the threshold is uncertain in future devices, if driven coherently though the SOL, the upper limit for the resulting field would exceed the present experimental threshold. This analysis provides the tools required for estimating the magnitude of the coherent SOL current and RMP generated via toroidally asymmetric biasing of the target. Flux expansion increases the RMP near the X-point, while phase interference due to the shearing of field lines near the X-point reduces the amplitude of the effective SOL perturbation and makes the result sensitive to both toroidal mode number n and the radial coherence width of the biasing region. If the limiting current density decays rapidly enough radially, both the width and the amplitude of the current density drawn from the target will be reduced. The RMP can still exceed the present threshold at low n if the radial location and width of the biasing region are optimally chosen.

  8. Layer-by-Layer Characterization of a Model Biofuel Cell Anode by (in Situ) Vibrational Spectroscopy

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    Layer-by-Layer Characterization of a Model Biofuel Cell Anode by (in Situ) Vibrational Spectroscopy during the construction of a model biofuel cell anode. The model anode was a layered structure formedDH to the CB layer confirmed successful enzyme immobilization. 1. Introduction Biofuel cells use microorganisms

  9. Overcoming the Boundary Layer Turbulence at Dome C: Ground-Layer Adaptive Optics versus Tower

    E-Print Network [OSTI]

    Ashley, Michael C. B.

    Overcoming the Boundary Layer Turbulence at Dome C: Ground-Layer Adaptive Optics versus Tower T the boundary layer: mounting a telescope on a tower that physically puts it above the turbulent layer such a goal, two solutions can be proposed. The most intuitive one is to place a telescope on a tower

  10. Dense, layered membranes for hydrogen separation

    DOE Patents [OSTI]

    Roark, Shane E.; MacKay, Richard; Mundschau, Michael V.

    2006-02-21T23:59:59.000Z

    This invention provides hydrogen-permeable membranes for separation of hydrogen from hydrogen-containing gases. The membranes are multi-layer having a central hydrogen-permeable layer with one or more catalyst layers, barrier layers, and/or protective layers. The invention also relates to membrane reactors employing the hydrogen-permeable membranes of the invention and to methods for separation of hydrogen from a hydrogen-containing gas using the membranes and reactors. The reactors of this invention can be combined with additional reactor systems for direct use of the separated hydrogen.

  11. Comparative study of InGaP/GaAs high electron mobility transistors with upper and lower delta-doped supplied layers

    SciTech Connect (OSTI)

    Tsai, Jung-Hui, E-mail: jhtsai@nknucc.nknu.edu.tw; Ye, Sheng-Shiun [National Kaohsiung Normal University, Department of Electronic Engineering, Taiwan (China); Guo, Der-Feng [Air Force Academy, Kaohsiung, Department of Electronic Engineering, Taiwan (China); Lour, Wen-Shiung [National Taiwan Ocean University, Department of Electrical Engineering, Taiwan (China)

    2012-04-15T23:59:59.000Z

    Influence corresponding to the position of {delta}-doped supplied layer on InGaP/GaAs high electron mobility transistors is comparatively studied by two-dimensional simulation analysis. The simulated results exhibit that the device with lower {delta}-doped supplied layer shows a higher gate potential barrier height, a higher saturation output current, a larger magnitude of negative threshold voltage, and broader gate voltage swing, as compared to the device with upper {delta}-doped supplied layer. Nevertheless, it has smaller transconductance and inferior high-frequency characteristics in the device with lower {delta}-doped supplied layer. Furthermore, a knee effect in current-voltage curves is observed at low drain-to-source voltage in the two devices, which is investigated in this article.

  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. Combustion fronts in porous media with two layers Steve Schecter

    E-Print Network [OSTI]

    Schecter, Stephen

    Combustion fronts in porous media with two layers layer 1 layer 2 Steve Schecter North Carolina Subject: Propagation of a combustion front through a porous medium with two parallel layers having different properties. · Each layer admits a traveling combustion wave. · The layers are coupled by heat

  18. Method to fabricate layered material compositions

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A new class of processes suited to the fabrication of layered material compositions is disclosed. Layered material compositions are typically three-dimensional structures which can be decomposed into a stack of structured layers. The best known examples are the photonic lattices. The present invention combines the characteristic features of photolithography and chemical-mechanical polishing to permit the direct and facile fabrication of, e.g., photonic lattices having photonic bandgaps in the 0.1-20.mu. spectral range.

  19. Method to fabricate layered material compositions

    DOE Patents [OSTI]

    Fleming, James G.; Lin, Shawn-Yu

    2004-11-02T23:59:59.000Z

    A new class of processes suited to the fabrication of layered material compositions is disclosed. Layered material compositions are typically three-dimensional structures which can be decomposed into a stack of structured layers. The best known examples are the photonic lattices. The present invention combines the characteristic features of photolithography and chemical-mechanical polishing to permit the direct and facile fabrication of, e.g., photonic lattices having photonic bandgaps in the 0.1-20.mu. spectral range.

  20. Manganese containing layer for magnetic recording media

    DOE Patents [OSTI]

    Lambeth, David N. (Pittsburgh, PA); Lee, Li-Lien (Santa Clara, CA); Laughlin, David E. (Pittsburgh, PA)

    1999-01-01T23:59:59.000Z

    The present invention provides for a magnetic recording media incorporating Mn-containing layers between a substrate and a magnetic layer to provide media having increased coercivity and lower noise. The Mn-containing layer can be incorporated in a rotating, translating or stationary recording media to operate in conjunction with magnetic transducing heads for recording and reading of magnetic data, as well as other applications. The magnetic recording medium of the invention preferably includes a Co or Co alloy film magnetic layer, and Mn-containing layer, preferably comprised of VMn, TiMn, MnZn, CrMnMo, CrMnW, CrMnV, and CrMnTi, and most preferably a CrMn alloy, disposed between the substrate and the magnetic layer to promote an epitaxial crystalline structure in the magnetic layer. The medium can further include seed layers, preferably polycrystalline MgO for longitudinal media, underlayers, and intermediate layers. Underlayers and intermediate layers are comprised of materials having either an A2 structure or a B2-ordered crystalline structure disposed between the seed layer and the magnetic layer. Materials having an A2 structure are preferably Cr or Cr alloys, such as CrV, CrMo, CrW and CrTi. Materials having a B2-ordered structure having a lattice constant that is substantially comparable to that of Cr, such as those preferably selected from the group consisting of NiAl, AILCo, FeAl, FeTi, CoFe, CoTi, CoHf, CoZr, NiTi, CuBe, CuZn, A-LMn, AlRe, AgMg, and Al.sub.2 FeMn.sub.2, and is most preferably FeAl or NiAl.

  1. 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.

  2. 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.

  3. 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).

  4. 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...

  5. Sandia National Laboratories: atomic layer deposition

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

    layer deposition Combining 'Tinkertoy' Materials with Solar Cells for Increased Photovoltaic Efficiency On December 4, 2014, in Energy, Materials Science, News, News & Events,...

  6. Enhanced Densification of SDC Barrier Layers

    SciTech Connect (OSTI)

    Hardy, John S.; Templeton, Jared W.; Lu, Zigui; Stevenson, Jeffry W.

    2011-09-12T23:59:59.000Z

    This technical report explores the Enhanced Densification of SCD Barrier Layers A samaria-doped ceria (SDC) barrier layer separates the lanthanum strontium cobalt ferrite (LSCF) cathode from the yttria-stabilized zirconia (YSZ) electrolyte in a solid oxide fuel cell (SOFC) to prevent the formation of electrically resistive interfacial SrZrO{sub 3} layers that arise from the reaction of Sr from the LSCF with Zr from the YSZ. However, the sintering temperature of this SDC layer must be limited to {approx}1200 C to avoid extensive interdiffusion between SDC and YSZ to form a resistive CeO{sub 2}-ZrO{sub 2} solid solution. Therefore, the conventional SDC layer is often porous and therefore not as impervious to Sr-diffusion as would be desired. In the pursuit of improved SOFC performance, efforts have been directed toward increasing the density of the SDC barrier layer without increasing the sintering temperature. The density of the SDC barrier layer can be greatly increased through small amounts of Cu-doping of the SDC powder together with increased solids loading and use of an appropriate binder system in the screen print ink. However, the resulting performance of cells with these barrier layers did not exhibit the expected increase in accordance with that achieved with the prototypical PLD SDC layer. It was determined by XRD that increased sinterability of the SDC also results in increased interdiffusivity between the SDC and YSZ, resulting in formation of a highly resistive solid solution.

  7. Electronic Transport in Few-layer Graphene

    E-Print Network [OSTI]

    Zhao, Zeng

    2013-01-01T23:59:59.000Z

    in Charge Neutral Bilayer Graphene Introduction In thisstudy on heterogeneous graphene devices in a differentto probe few layer graphene to determine their dependence on

  8. Organic photovoltaic cells utilizing ultrathin sensitizing layer

    DOE Patents [OSTI]

    Forrest, Stephen R. (Ann Arbor, MI); Yang, Fan (Piscataway, NJ); Rand, Barry P. (Somers, NY)

    2011-09-06T23:59:59.000Z

    A photosensitive device includes a plurality of organic photoconductive materials disposed in a stack between a first electrode and a second electrode, including a first continuous layer of donor host material, a second continuous layer of acceptor host material, and at least one other organic photoconductive material disposed as a plurality of discontinuous islands between the first continuous layer and the second continuous layer. Each of these other photoconductive materials has an absorption spectra different from the donor host material and the acceptor host material. Preferably, each of the discontinuous islands consists essentially of a crystallite of the respective organic photoconductive material, and more preferably, the crystallites are nanocrystals.

  9. Nanomanufacturing : nano-structured materials made layer-by-layer.

    SciTech Connect (OSTI)

    Cox, James V.; Cheng, Shengfeng; Grest, Gary Stephen; Tjiptowidjojo, Kristianto (University of New Mexico); Reedy, Earl David, Jr.; Fan, Hongyou; Schunk, Peter Randall; Chandross, Michael Evan; Roberts, Scott A.

    2011-10-01T23:59:59.000Z

    Large-scale, high-throughput production of nano-structured materials (i.e. nanomanufacturing) is a strategic area in manufacturing, with markets projected to exceed $1T by 2015. Nanomanufacturing is still in its infancy; process/product developments are costly and only touch on potential opportunities enabled by growing nanoscience discoveries. The greatest promise for high-volume manufacturing lies in age-old coating and imprinting operations. For materials with tailored nm-scale structure, imprinting/embossing must be achieved at high speeds (roll-to-roll) and/or over large areas (batch operation) with feature sizes less than 100 nm. Dispersion coatings with nanoparticles can also tailor structure through self- or directed-assembly. Layering films structured with these processes have tremendous potential for efficient manufacturing of microelectronics, photovoltaics and other topical nano-structured devices. This project is designed to perform the requisite R and D to bring Sandia's technology base in computational mechanics to bear on this scale-up problem. Project focus is enforced by addressing a promising imprinting process currently being commercialized.

  10. 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}

  11. 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.

  12. Fabrication of silica aerogel with $n$ = 1.08 for $e^+/\\mu ^+$ separation in a threshold Cherenkov counter of the J-PARC TREK/E36 experiment

    E-Print Network [OSTI]

    Tabata, Makoto; Kawai, Hideyuki; Igarashi, Youichi; Imazato, Jun; Shimizu, Suguru; Yamazaki, Hirohito

    2015-01-01T23:59:59.000Z

    This study presents the development of hydrophobic silica aerogel for use as a radiator in threshold-type Cherenkov counters. These counters are to be used for separating positrons and positive muons produced by kaon decay in the J-PARC TREK/E36 experiment. We chose to employ aerogel with a refractive index of 1.08 to identify charged particles with momenta of approximately 240 MeV/$c$, and the radiator block shape was designed with a trapezoidal cross-section to fit the barrel region surrounding the kaon stopping target in the center of the TREK/E36 detector system. Including spares, we obtained 30 crack-free aerogel blocks segmented into two layers, each layer having a thickness of 2 cm and a length of 18 cm, to fill 12 counter modules. Optical measurements showed that the produced aerogel tiles had the required refractive indices and transparency.

  13. 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)).

  14. 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.

  15. 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...

  16. 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.

  17. Layer-by-Layer Assembly of a pH-Responsive and Electrochromic Thin Film

    E-Print Network [OSTI]

    Schmidt, Daniel J.

    This article summarizes an experiment on thin-film fabrication with layer-by-layer assembly that is appropriate for undergraduate laboratory courses. The purpose of this experiment is to teach students about self-assembly ...

  18. An ultra-thin buffer layer for Ge epitaxial layers on Si

    SciTech Connect (OSTI)

    Kawano, M.; Yamada, S.; Tanikawa, K.; Miyao, M.; Hamaya, K. [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan)] [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Sawano, K. [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Tokyo 158-0082 (Japan)] [Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Tokyo 158-0082 (Japan)

    2013-03-25T23:59:59.000Z

    Using an Fe{sub 3}Si insertion layer, we study epitaxial growth of Ge layers on a Si substrate by a low-temperature molecular beam epitaxy technique. When we insert only a 10-nm-thick Fe{sub 3}Si layer in between Si and Ge, epitaxial Ge layers can be obtained on Si. The detailed structural characterizations reveal that a large lattice mismatch of {approx}4% is completely relaxed in the Fe{sub 3}Si layer. This means that the Fe{sub 3}Si layers can become ultra-thin buffer layers for Ge on Si. This method will give a way to realize a universal buffer layer for Ge, GaAs, and related devices on a Si platform.

  19. Surface engineering using layer-by-layer assembly of pH-sensitive polymers and nanoparticles

    E-Print Network [OSTI]

    Lee, Daeyeon

    2007-01-01T23:59:59.000Z

    Surface engineering of a variety of materials including colloidal particles and porous membranes has been achieved by using layer-by-layer assembly of pH-sensitive polymers and nanoparticles. In the first part of this ...

  20. Amperometric Glucose Biosensor by Means of Electrostatic Layer-by-layer Adsorption onto Electrospun Polyaniline Fibers

    E-Print Network [OSTI]

    Shin, Young J.

    2010-07-14T23:59:59.000Z

    were formed and collected by electrospinning. Glucose oxidase was immobilized onto these fibers using an electrostatic layer-by-layer adsorption technique. In this method, poly(diallyldimethylammonium chloride) was used as the counter ion source...

  1. automated spin-assisted layer-by-layer: Topics by E-print Network

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

    Thomas 2005-01-01 16 Layer-by-Layer Assembly of a pH-Responsive and Electrochromic Thin Film MIT - DSpace Summary: This article summarizes an experiment on thin-film fabrication...

  2. Engineering the electrochromism and ion conduction of layer-by-layer assembled films

    E-Print Network [OSTI]

    DeLongchamp, Dean M. (Dean Michael), 1975-

    2003-01-01T23:59:59.000Z

    This work applies the processing technique of layer-by-layer (LBL) assembly to the creation and development of new electrochemically active materials. Elements of the thin-film electrochromic cell were chosen as a particular ...

  3. Antimicrobial Activity of Cationic Antiseptics in Layer-by-Layer Thin Film Assemblies

    E-Print Network [OSTI]

    Dvoracek, Charlene M.

    2010-07-14T23:59:59.000Z

    Layer-by-layer (LbL) assembly has proven to be a powerful technique for assembling thin films with a variety of properties including electrochromic, molecular sensing, oxygen barrier, and antimicrobial. LbL involves the deposition of alternating...

  4. Cyclone separator having boundary layer turbulence control

    DOE Patents [OSTI]

    Krishna, Coimbatore R. (Mt. Sinai, NY); Milau, Julius S. (Port Jefferson, NY)

    1985-01-01T23:59:59.000Z

    A cyclone separator including boundary layer turbulence control that is operable to prevent undue build-up of particulate material at selected critical areas on the separator walls, by selectively varying the fluid pressure at those areas to maintain the momentum of the vortex, thereby preventing particulate material from inducing turbulence in the boundary layer of the vortical fluid flow through the separator.

  5. Steady water waves with multiple critical layers

    E-Print Network [OSTI]

    Mats Ehrnström; Joachim Escher; Erik Wahlén

    2011-04-01T23:59:59.000Z

    We construct small-amplitude periodic water waves with multiple critical layers. In addition to waves with arbitrarily many critical layers and a single crest in each period, two-dimensional sets of waves with several crests and troughs in each period are found. The setting is that of steady two-dimensional finite-depth gravity water waves with vorticity.

  6. Channel cracks in atomic-layer and molecular-layer deposited multilayer thin film coatings

    SciTech Connect (OSTI)

    Long, Rong, E-mail: rlongmech@gmail.com [Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8 (Canada); Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Dunn, Martin L. [Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Singapore University of Technology and Design, Singapore 138682 (Singapore)

    2014-06-21T23:59:59.000Z

    Metal oxide thin film coatings produced by atomic layer deposition have been shown to be an effective permeation barrier. The primary failure mode of such coatings under tensile loads is the propagation of channel cracks that penetrate vertically into the coating films. Recently, multi-layer structures that combine the metal oxide material with relatively soft polymeric layers produced by molecular layer deposition have been proposed to create composite thin films with desired properties, including potentially enhanced resistance to fracture. In this paper, we study the effects of layer geometry and material properties on the critical strain for channel crack propagation in the multi-layer composite films. Using finite element simulations and a thin-film fracture mechanics formalism, we show that if the fracture energy of the polymeric layer is lower than that of the metal oxide layer, the channel crack tends to penetrate through the entire composite film, and dividing the metal oxide and polymeric materials into thinner layers leads to a smaller critical strain. However, if the fracture energy of the polymeric material is high so that cracks only run through the metal oxide layers, more layers can result in a larger critical strain. For intermediate fracture energy of the polymer material, we developed a design map that identifies the optimal structure for given fracture energies and thicknesses of the metal oxide and polymeric layers. These results can facilitate the design of mechanically robust permeation barriers, an important component for the development of flexible electronics.

  7. Final report for CCS cross-layer reliability visioning study

    SciTech Connect (OSTI)

    Quinn, Heather M [Los Alamos National Laboratory; Dehon, Andre [U. PENN; Carter, Nicj [INTEL

    2010-12-20T23:59:59.000Z

    The geometric rate of improvement of transistor size and integrated circuit performance known as Moore's Law has been an engine of growth for our economy, enabling new products and services, creating new value and wealth, increasing safety, and removing menial tasks from our daily lives. Affordable, highly integrated components have enabled both life-saving technologies and rich entertainment applications. Anti-lock brakes, insulin monitors, and GPS-enabled emergency response systems save lives. Cell phones, internet appliances, virtual worlds, realistic video games, and mp3 players enrich our lives and connect us together. Over the past 40 years of silicon scaling, the increasing capabilities of inexpensive computation have transformed our society through automation and ubiquitous communications. Looking forward, increasing unpredictability threatens our ability to continue scaling integrated circuits at Moore's Law rates. As the transistors and wires that make up integrated circuits become smaller, they display both greater differences in behavior among devices designed to be identical and greater vulnerability to transient and permanent faults. Conventional design techniques expend energy to tolerate this unpredictability by adding safety margins to a circuit's operating voltage, clock frequency or charge stored per bit. However, the rising energy costs needed to compensate for increasing unpredictability are rapidly becoming unacceptable in today's environment where power consumption is often the limiting factor on integrated circuit performance and energy efficiency is a national concern. Reliability and energy consumption are both reaching key inflection points that, together, threaten to reduce or end the benefits of feature size reduction. To continue beneficial scaling, we must use a cross-layer, Jull-system-design approach to reliability. Unlike current systems, which charge every device a substantial energy tax in order to guarantee correct operation in spite of rare events, such as one high-threshold transistor in a billion or one erroneous gate evaluation in an hour of computation, cross-layer reliability schemes make reliability management a cooperative effort across the system stack, sharing information across layers so that they only expend energy on reliability when an error actually occurs. Figure 1 illustrates an example of such a system that uses a combination of information from the application and cheap architecture-level techniques to detect errors. When an error occurs, mechanisms at higher levels in the stack correct the error, efficiently delivering correct operation to the user in spite of errors at the device or circuit levels. In the realms of memory and communication, engineers have a long history of success in tolerating unpredictable effects such as fabrication variability, transient upsets, and lifetime wear using information sharing, limited redundancy, and cross-layer approaches that anticipate, accommodate, and suppress errors. Networks use a combination of hardware and software to guarantee end-toend correctness. Error-detection and correction codes use additional information to correct the most common errors, single-bit transmission errors. When errors occur that cannot be corrected by these codes, the network protocol requests re-transmission of one or more packets until the correct data is received. Similarly, computer memory systems exploit a cross-layer division of labor to achieve high performance with modest hardware. Rather than demanding that hardware alone provide the virtual memory abstraction, software page-fault and TLB-miss handlers allow a modest piece of hardware, the TLB, to handle the common-case operations on a cyc1e-by-cycle basis while infrequent misses are handled in system software. Unfortunately, mitigating logic errors is not as simple or as well researched as memory or communication systems. This lack of understanding has led to very expensive solutions. For example, triple-modular redundancy masks errors by triplicating computations in either time or area. T

  8. 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.

  9. Electropositive surface layer MPD thruster cathodes

    SciTech Connect (OSTI)

    Chamberlain, F.R.; Kelly, A.J.; Jahn, R.G.

    1989-01-01T23:59:59.000Z

    Lithium and barium oxide have been used to generate electropositive surface layers on tungsten cathodes in low power steady state MPD thruster experiments. The electropositive surface layer decreases the cathode work function, resulting in substantial reductions in the steady state cathode operating temperature and erosion rate. Cathode temperature is reduced by 300 degrees with a lithium surface layer and by 800 degrees with a barium oxide surface layer at a 500 ampere thruster current level. These temperature reductions substantially reduce the calculated steady state evaporative erosion rate of the cathode by factors of 20 and 10,000 respectively. Cold cathode startup erosion is also reduced dramatically. The surface melting and arc cratering that is characteristic of pure tungsten cathodes does not occur with an electropositive surface layer cathode. In addition to reducing cathode erosion, the use of these materials increases thruster efficiency. 12 refs.

  10. Main Sequence Evolution with Layered Semiconvection

    E-Print Network [OSTI]

    Moore, Kevin

    2015-01-01T23:59:59.000Z

    Semiconvection - mixing that occurs in regions that are stable when considering compositional gradients, but unstable when ignoring them - is shown to have the greatest potential impact on main sequence stars with masses in the range 1.2 - 1.7 solar masses. We present the first stellar evolution calculations using a prescription for semiconvection derived from extrapolation of direct numerical simulations of double-diffusive mixing down to stellar parameters. The dominant mode of semiconvection in stars is layered semiconvection, where the layer height is an adjustable parameter analogous to the mixing length in convection. The rate of mixing across the semiconvective region is sensitively dependent on the layer height. We find that there is a critical layer height that separates weak semiconvective mixing (where evolution is well-approximated by using the Ledoux criterion) from strong semiconvective mixing (where evolution is well-approximated by using the Schwarzschild criterion). This critical layer height...

  11. 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

  12. 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...

  13. 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

  14. 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

  15. 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...

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  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. $J/?$ 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.

  19. 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.

  20. Low temperature thin film transistors with hollow cathode plasma-assisted atomic layer deposition based GaN channels

    SciTech Connect (OSTI)

    Bolat, S., E-mail: bolat@ee.bilkent.edu.tr, E-mail: aokyay@ee.bilkent.edu.tr; Tekcan, B. [Department of Electrical and Electronics Engineering, Bilkent University, Ankara 06800 (Turkey); UNAM, National Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Ozgit-Akgun, C.; Biyikli, N. [UNAM, National Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Okyay, A. K., E-mail: bolat@ee.bilkent.edu.tr, E-mail: aokyay@ee.bilkent.edu.tr [Department of Electrical and Electronics Engineering, Bilkent University, Ankara 06800 (Turkey); UNAM, National Nanotechnology Research Center, Bilkent University, Ankara 06800 (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey)

    2014-06-16T23:59:59.000Z

    We report GaN thin film transistors (TFT) with a thermal budget below 250?°C. GaN thin films are grown at 200?°C by hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD). HCPA-ALD-based GaN thin films are found to have a polycrystalline wurtzite structure with an average crystallite size of 9.3?nm. TFTs with bottom gate configuration are fabricated with HCPA-ALD grown GaN channel layers. Fabricated TFTs exhibit n-type field effect characteristics. N-channel GaN TFTs demonstrated on-to-off ratios (I{sub ON}/I{sub OFF}) of 10{sup 3} and sub-threshold swing of 3.3?V/decade. The entire TFT device fabrication process temperature is below 250?°C, which is the lowest process temperature reported for GaN based transistors, so far.

  1. Electrical Engineering and Computer Cross-Layer Design

    E-Print Network [OSTI]

    Electrical Engineering and Computer Science Cross-Layer Design and Analysis of Wireless Networks Layer Design #12;Electrical Engineering and Computer Science Layered Approach Presentation Layer Session;Electrical Engineering and Computer Science Why not cross-layer design? · Difficulty. · Lack of insight

  2. Superconductive articles including cerium oxide layer

    DOE Patents [OSTI]

    Wu, X.D.; Muenchausen, R.E.

    1993-11-16T23:59:59.000Z

    A ceramic superconductor comprising a metal oxide substrate, a ceramic high temperature superconductive material, and a intermediate layer of a material having a cubic crystal structure, said layer situated between the substrate and the superconductive material is provided, and a structure for supporting a ceramic superconducting material is provided, said structure comprising a metal oxide substrate, and a layer situated over the surface of the substrate to substantially inhibit interdiffusion between the substrate and a ceramic superconducting material deposited upon said structure. 7 figures.

  3. Method for forming a barrier layer

    DOE Patents [OSTI]

    Weihs, Timothy P. (Baltimore, MD); Barbee, Jr., Troy W. (Palo Alto, CA)

    2002-01-01T23:59:59.000Z

    Cubic or metastable cubic refractory metal carbides act as barrier layers to isolate, adhere, and passivate copper in semiconductor fabrication. One or more barrier layers of the metal carbide are deposited in conjunction with copper metallizations to form a multilayer characterized by a cubic crystal structure with a strong (100) texture. Suitable barrier layer materials include refractory transition metal carbides such as vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (Cr.sub.3 C.sub.2), tungsten carbide (WC), and molybdenum carbide (MoC).

  4. Energy transport using natural convection boundary layers

    SciTech Connect (OSTI)

    Anderson, R.

    1986-04-01T23:59:59.000Z

    Natural convection is one of the major modes of energy transport in passive solar buildings. There are two primary mechanisms for natural convection heat transport through an aperture between building zones: (1) bulk density differences created by temperature differences between zones; and (2) thermosyphon pumping created by natural convection boundary layers. The primary objective of the present study is to compare the characteristics of bulk density driven and boundary layer driven flow, and discuss some of the advantages associated with the use of natural convection boundary layers to transport energy in solar building applications.

  5. Centrifugal instability of Stokes layers in crossflow: the case of a forced cylinder wake

    E-Print Network [OSTI]

    D'Adamo, Juan; Wesfreid, José Eduardo

    2015-01-01T23:59:59.000Z

    The wake flow around a circular cylinder at $Re\\approx100$ performing rotatory oscillations has been thoroughly discussed in the literature, mostly focusing on the modifications to the natural B\\'enard-von K\\'arm\\'an vortex street that result from the forced shedding modes locked to the rotatory oscillation frequency. The usual experimental and theoretical frameworks at these Reynolds numbers are quasi-two-dimensional, since the secondary instabilities bringing a three-dimensional structure to the cylinder wake flow occur only at higher Reynolds numbers. In the present paper we show that a three-dimensional structure can appear below the usual three-dimensionalization threshold, when forcing with frequencies lower than the natural vortex shedding frequency, at high amplitudes, as a result of a previously unreported mechanism: a pulsed centrifugal instability of the oscillating Stokes layer at the wall of the cylinder. The present numerical investigation lets us in this way propose a physical explanation for t...

  6. Double layer electric fields aiding the production of energetic flat-top distributions and superthermal electrons within the exhausts from magnetic reconnection

    E-Print Network [OSTI]

    Egedal, Jan; Le, Ari; Borg, Anette L

    2015-01-01T23:59:59.000Z

    Using a kinetic simulation of magnetic reconnection it was recently shown that magnetic-field-aligned electric fields (E||) can be present over large spatial scales in reconnection exhausts. The largest values of E|| are observed within double layers. The existence of double layers in the Earth's magnetosphere is well documented. In our simulation their formation is triggered by large parallel streaming of electrons into the reconnection region. These parallel electron fluxes are required for maintaining quasi-neutrality of the reconnection region and increase with decreasing values of the normalized electron pressure upstream of the reconnection region. A threshold normalized pressure is derived for strong double layers to develop. We also document how the electron confinement, provided in part by the structure in E||, allows sustained energization by perpendicular electric fields. The energization is a consequence of the confined electrons' chaotic orbital motion that includes drifts aligned with the reconn...

  7. Abstraction Layers for Scalable Microfluidic Biocomputers

    E-Print Network [OSTI]

    Amarasinghe, Saman

    Abstraction Layers for Scalable Microfluidic Biocomputers William Thies1 , John Paul Urbanski2 Hatsopoulos Microfluids Laboratory Massachusetts Institute of Technology {thies, urbanski, thorsen, saman}@mit.edu Abstract. Microfluidic devices are emerging as an attractive technol- ogy for automatically orchestrating

  8. Layered solid sorbents for carbon dioxide capture

    SciTech Connect (OSTI)

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2014-11-18T23:59:59.000Z

    A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

  9. Counting molecular-beam grown graphene layers

    SciTech Connect (OSTI)

    Plaut, Annette S. [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom)] [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Wurstbauer, Ulrich [Department of Physics, Columbia University, New York, New York 10027 (United States)] [Department of Physics, Columbia University, New York, New York 10027 (United States); Pinczuk, Aron [Department of Physics, Columbia University, New York, New York 10027 (United States) [Department of Physics, Columbia University, New York, New York 10027 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Garcia, Jorge M. [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain)] [MBE Lab, IMM-Instituto de Microelectronica de Madrid (CNM-CSIC), Madrid, E-28760 (Spain); Pfeiffer, Loren N. [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)] [Electrical Engineering Department, Princeton University, New Jersey 08544 (United States)

    2013-06-17T23:59:59.000Z

    We have used the ratio of the integrated intensity of graphene's Raman G peak to that of the silicon substrate's first-order optical phonon peak, accurately to determine the number of graphene layers across our molecular-beam (MB) grown graphene films. We find that these results agree well both, with those from our own exfoliated single and few-layer graphene flakes, and with the results of Koh et al.[ACS Nano 5, 269 (2011)]. We hence distinguish regions of single-, bi-, tri-, four-layer, etc., graphene, consecutively, as we scan coarsely across our MB-grown graphene. This is the first, but crucial, step to being able to grow, by such molecular-beam-techniques, a specified number of large-area graphene layers, to order.

  10. Josephson vortex lattice in layered superconductors

    SciTech Connect (OSTI)

    Koshelev, A. E., E-mail: koshelev@anl.gov [Argonne National Laboratory, Materials Science Division (United States); Dodgson, M. J. W. [Cavendish Laboratory, Theory of Condensed Matter Group (United Kingdom)] [Cavendish Laboratory, Theory of Condensed Matter Group (United Kingdom)

    2013-09-15T23:59:59.000Z

    Many superconducting materials are composed of weakly coupled conducting layers. Such a layered structure has a very strong influence on the properties of vortex matter in a magnetic field. This review focuses on the properties of the Josephson vortex lattice generated by the magnetic field applied in the direction of the layers. The theoretical description is based on the Lawrence-Doniach model in the London limit, which takes only the phase degree of freedom of the superconducting order parameter into account. In spite of its simplicity, this model leads to an amazingly rich set of phenomena. We review in detail the structure of an isolated vortex line and various properties of the vortex lattice, in both dilute and dense limits. In particular, we extensively discuss the influence of the layered structure and thermal fluctuations on the selection of lattice configurations at different magnetic fields.

  11. Multi-layer waste containment barrier

    DOE Patents [OSTI]

    Smith, Ann Marie (Pocatello, ID); Gardner, Bradley M. (Idaho Falls, ID); Nickelson, David F. (Idaho Falls, ID)

    1999-01-01T23:59:59.000Z

    An apparatus for constructing an underground containment barrier for containing an in-situ portion of earth. The apparatus includes an excavating device for simultaneously (i) excavating earthen material from beside the in-situ portion of earth without removing the in-situ portion and thereby forming an open side trench defined by opposing earthen sidewalls, and (ii) excavating earthen material from beneath the in-situ portion of earth without removing the in-situ portion and thereby forming a generally horizontal underground trench beneath the in-situ portion defined by opposing earthen sidewalls. The apparatus further includes a barrier-forming device attached to the excavating device for simultaneously forming a side barrier within the open trench and a generally horizontal, multi-layer barrier within the generally horizontal trench. The multi-layer barrier includes at least a first layer and a second layer.

  12. Finite element analysis of shells with layers

    E-Print Network [OSTI]

    Hiller, Jean-François, 1974-

    2002-01-01T23:59:59.000Z

    It is well established that thin shell structures frequently feature narrow bands of strain concentration and localized displacement irregularities referred to as boundary and internal layers. It is crucial to capture these ...

  13. Double layer capacitors : automotive applications and modeling

    E-Print Network [OSTI]

    New, David Allen, 1976-

    2004-01-01T23:59:59.000Z

    This thesis documents the work on the modeling of double layer capacitors (DLCs) and the validation of the modeling procedure. Several experiments were conducted to subject the device under test to a variety of ...

  14. Analytical Layer Planning for Nanometer VLSI Designs 

    E-Print Network [OSTI]

    Chang, Chi-Yu

    2012-10-19T23:59:59.000Z

    i ANALYTICAL LAYER PLANNING FOR NANOMETER VLSI DESIGNS A Thesis by CHI-YU CHANG 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 2012 Major Subject: Electrical Engineering ii ANALYTICAL LAYER PLANNING FOR NANOMETER VLSI DESIGNS A Thesis by CHI-YU CHANG Submitted to the Office of Graduate Studies of Texas A&M University in partial...

  15. Symmetry Breaking in Few Layer Graphene Films

    SciTech Connect (OSTI)

    Bostwick, A.; Ohta, T.; McChesney, J.L.; Emtsev, K.; Seyller,Th.; Horn, K.; Rotenberg, E.

    2007-05-25T23:59:59.000Z

    Recently, it was demonstrated that the quasiparticledynamics, the layer-dependent charge and potential, and the c-axisscreening coefficient could be extracted from measurements of thespectral function of few layer graphene films grown epitaxially on SiCusing angle-resolved photoemission spectroscopy (ARPES). In this articlewe review these findings, and present detailed methodology for extractingsuch parameters from ARPES. We also present detailed arguments againstthe possibility of an energy gap at the Dirac crossing ED.

  16. Lattice Vibrations and Superconductivity in Layered Structures

    E-Print Network [OSTI]

    Allen, Roland E.; Alldredg, GP; WETTE, FWD.

    1970-01-01T23:59:59.000Z

    PHYSICAL REVIEW B VOLUME 2, NUMBER 7 1 OCTOB ER, 1970 Lattice Vibrations and Superconductivity in Layered Structures* B. E. Allen, G. P. Alldredge, and F. W. de bette DePartment of Physics, University of Texas, Austin, Texas 78712 (Received 18... May 1970) In order to estimate the influence of both surface and interface effects on phonon frequencies and superconducting transition temperatures in layered structures, we have calculated the vibrational modes of structures composed...

  17. Optical devices featuring textured semiconductor layers

    DOE Patents [OSTI]

    Moustakas, Theodore D. (Dover, MA); Cabalu, Jasper S. (Cary, NC)

    2012-08-07T23:59:59.000Z

    A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

  18. Optical devices featuring textured semiconductor layers

    DOE Patents [OSTI]

    Moustakas, Theodore D. (Dover, MA); Cabalu, Jasper S. (Cary, NC)

    2011-10-11T23:59:59.000Z

    A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

  19. Optical devices featuring nonpolar textured semiconductor layers

    DOE Patents [OSTI]

    Moustakas, Theodore D; Moldawer, Adam; Bhattacharyya, Anirban; Abell, Joshua

    2013-11-26T23:59:59.000Z

    A semiconductor emitter, or precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate in a nonpolar orientation. The textured layers enhance light extraction, and the use of nonpolar orientation greatly enhances internal quantum efficiency compared to conventional devices. Both the internal and external quantum efficiencies of emitters of the invention can be 70-80% or higher. The invention provides highly efficient light emitting diodes suitable for solid state lighting.

  20. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    E-Print Network [OSTI]

    Whitesides, R.; Domin, D.; Salomon-Ferrer, R.; Lester Jr., W.A.; Frenklach, M.

    2008-01-01T23:59:59.000Z

    are incorporated into growing graphene layers and hence willGRAPHENE LAYER GROWTH CHEMISTRY: FIVE-SIX-RING FLIP REACTIONon the zigzag edge of a graphene layer. A new reaction

  1. Graphene Layer Growth Chemistry: Five-Six-Ring Flip Reaction

    E-Print Network [OSTI]

    Whitesides, Russell; Domin, Dominik; Lester Jr., William A.; Frenklach, Michael

    2007-01-01T23:59:59.000Z

    25-28, 2007. Topic: Soot GRAPHENE LAYER GROWTH CHEMISTRY:on the zigzag edge of a graphene layer isomerizes to reversea possibly important step in graphene layer growth, thus

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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)].

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. L{sub g}?=?100?nm In{sub 0.7}Ga{sub 0.3}As quantum well metal-oxide semiconductor field-effect transistors with atomic layer deposited beryllium oxide as interfacial layer

    SciTech Connect (OSTI)

    Koh, D., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States); SEMATECH, Inc., Albany, New York 12203 (United States); Kwon, H. M. [Department of Electronics Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, T.-W., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org; Veksler, D.; Gilmer, D.; Kirsch, P. D. [SEMATECH, Inc., Albany, New York 12203 (United States); Kim, D.-H. [SEMATECH, Inc., Albany, New York 12203 (United States); GLOBALFOUNDRIES, Malta, New York 12020 (United States); Hudnall, Todd W. [Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, 78666 (United States); Bielawski, Christopher W. [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States); Maszara, W. [GLOBALFOUNDRIES, Santa Clara, California 95054 (United States); Banerjee, S. K. [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

    2014-04-21T23:59:59.000Z

    In this study, we have fabricated nanometer-scale channel length quantum-well (QW) metal-oxide-semiconductor field effect transistors (MOSFETs) incorporating beryllium oxide (BeO) as an interfacial layer. BeO has high thermal stability, excellent electrical insulating characteristics, and a large band-gap, which make it an attractive candidate for use as a gate dielectric in making MOSFETs. BeO can also act as a good diffusion barrier to oxygen owing to its small atomic bonding length. In this work, we have fabricated In{sub 0.53}Ga{sub 0.47}As MOS capacitors with BeO and Al{sub 2}O{sub 3} and compared their electrical characteristics. As interface passivation layer, BeO/HfO{sub 2} bilayer gate stack presented effective oxide thickness less 1 nm. Furthermore, we have demonstrated In{sub 0.7}Ga{sub 0.3}As QW MOSFETs with a BeO/HfO{sub 2} dielectric, showing a sub-threshold slope of 100?mV/dec, and a transconductance (g{sub m,max}) of 1.1 mS/?m, while displaying low values of gate leakage current. These results highlight the potential of atomic layer deposited BeO for use as a gate dielectric or interface passivation layer for III–V MOSFETs at the 7?nm technology node and/or beyond.

  12. Organic light emitting device having multiple separate emissive layers

    DOE Patents [OSTI]

    Forrest, Stephen R. (Ann Arbor, MI)

    2012-03-27T23:59:59.000Z

    An organic light emitting device having multiple separate emissive layers is provided. Each emissive layer may define an exciton formation region, allowing exciton formation to occur across the entire emissive region. By aligning the energy levels of each emissive layer with the adjacent emissive layers, exciton formation in each layer may be improved. Devices incorporating multiple emissive layers with multiple exciton formation regions may exhibit improved performance, including internal quantum efficiencies of up to 100%.

  13. Hybrid inorganic–organic superlattice structures with atomic layer deposition/molecular layer deposition

    SciTech Connect (OSTI)

    Tynell, Tommi; Yamauchi, Hisao; Karppinen, Maarit, E-mail: maarit.karppinen@aalto.fi [Department of Chemistry, Aalto University, FI-00076 Aalto (Finland)

    2014-01-15T23:59:59.000Z

    A combination of the atomic layer deposition (ALD) and molecular layer deposition (MLD) techniques is successfully employed to fabricate thin films incorporating superlattice structures that consist of single layers of organic molecules between thicker layers of ZnO. Diethyl zinc and water are used as precursors for the deposition of ZnO by ALD, while three different organic precursors are investigated for the MLD part: hydroquinone, 4-aminophenol and 4,4?-oxydianiline. The successful superlattice formation with all the organic precursors is verified through x-ray reflectivity studies. The effects of the interspersed organic layers/superlattice structure on the electrical and thermoelectric properties of ZnO are investigated through resistivity and Seebeck coefficient measurements at room temperature. The results suggest an increase in carrier concentration for small concentrations of organic layers, while higher concentrations seem to lead to rather large reductions in carrier concentration.

  14. 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.

  15. 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.

  16. 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.

  17. Characterization of the plastic substrates, the reflective layers...

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

    the plastic substrates, the reflective layers, the adhesives, and the grooves of today's archival-grade Characterization of the plastic substrates, the reflective layers, the...

  18. antarctic boundary layer: Topics by E-print Network

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

    Geosciences Websites Summary: Boundary Layer Meteorology (METR 5103) Spring 2014 Syllabus General information Fundamentals of the atmospheric boundary layer dynamics and...

  19. atmosperic boundary layer: Topics by E-print Network

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

    Geosciences Websites Summary: Boundary Layer Meteorology (METR 5103) Spring 2014 Syllabus General information Fundamentals of the atmospheric boundary layer dynamics and...

  20. Vacancies Ordered in Screw Form (VOSF) and Layered Indium Selenide...

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

    Ordered in Screw Form (VOSF) and Layered Indium Selenide Thin Film Deposition by Laser Back Ablation. Vacancies Ordered in Screw Form (VOSF) and Layered Indium Selenide Thin Film...

  1. Amorphous layer coating induced brittle to ductile transition...

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

    layer coating induced brittle to ductile transition in single crystalline SiC nanowires: an atomistic simulation. Amorphous layer coating induced brittle to ductile transition in...

  2. Layered Electrodes for Lithium Cells and Batteries | Argonne...

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

    Layered Electrodes for Lithium Cells and Batteries Technology available for licensing: Layered lithium metal oxide compounds for ultra-high-capacity, rechargeable cathodes Lowers...

  3. Redox Chemistry in Thin Layers of Organometallic Complexes Prepared...

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

    Redox Chemistry in Thin Layers of Organometallic Complexes Prepared Using Ion Soft Landing. Redox Chemistry in Thin Layers of Organometallic Complexes Prepared Using Ion Soft...

  4. Removal of carbon tetrachloride from a layered porous medium...

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

    carbon tetrachloride from a layered porous medium by means of soil vapor extraction enhanced by desiccation and water Removal of carbon tetrachloride from a layered porous medium...

  5. Removal of Carbon Tetrachloride from a Layered Porous Medium...

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

    Carbon Tetrachloride from a Layered Porous Medium by Means of Soil Vapor Extraction Enhanced by Desiccation and Water Removal of Carbon Tetrachloride from a Layered Porous Medium...

  6. anisotropic porous layer: Topics by E-print Network

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

    of Highly Porous Catalytic Layers for Polymer Electrolyte Fuel Cell Based on Carbon Aerogels Physics Websites Summary: Synthesis of Highly Porous Catalytic Layers for Polymer...

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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...

  12. 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}.

  13. 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}.

  14. Characterization of CZTSSe photovoltaic device with an atomic layer-deposited passivation layer

    SciTech Connect (OSTI)

    Wu, Wei, E-mail: wei.wu@dupont.com; Cao, Yanyan; Caspar, Jonathan V.; Guo, Qijie; Johnson, Lynda K.; Mclean, Robert S.; Malajovich, Irina; Choudhury, Kaushik Roy [DuPont Central Research and Development, Wilmington, Delaware 19880 (United States)

    2014-07-28T23:59:59.000Z

    We describe a CZTSSe (Cu{sub 2}ZnSn(S{sub 1?x},Se{sub x}){sub 4}) photovoltaic (PV) device with an ALD (atomic layer deposition) coated buffer dielectric layer for CZTSSe surface passivation. An ALD buffer layer, such as TiO{sub 2}, can be applied in order to reduce the interface recombination and improve the device's open-circuit voltage. Detailed characterization data including current-voltage, admittance spectroscopy, and capacitance profiling are presented in order to compare the performance of PV devices with and without the ALD layer.

  15. Metal-sensing layer-semiconductor and metal-sensing layer-metal heterostructure gas sensors

    SciTech Connect (OSTI)

    O'Leary, M.; Li, Zheng; Fonash, S.J.

    1987-01-01T23:59:59.000Z

    Extremely sensitive gas sensors can be fabricated using heterostructures of the form metal-sensing layer-semiconductor or metal-sensing layer-metal. These structures are heterostructure diodes which have the barrier controlling transport at least partially located in the sensing layer. In the presence of the gas species to be detected, the electrical properties of the sensing layer evolve, resulting in a modification of the barrier to electric current transport and, hence, resulting in detection due to changes in the current-voltage characteristics of the device. This type of sensor structure is demonstrated using the Pd/Ti-O/sub x/Ti heterostructure hydrogen detector.

  16. 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.

  17. 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

  18. Layer-by-layer carbon nanotube electrodes for flexible chemical sensor and energy storage applications

    E-Print Network [OSTI]

    Saetia, Kittipong

    2013-01-01T23:59:59.000Z

    The spray-assisted layer-by-layer (LbL) technique has been investigated for creating multi-walled carbon nanotube (MWNT) films on porous electrospun fiber mats via LbL assembly of surface-functionalized MWNTs. Negative and ...

  19. Layer-by-layer assembly of conducting membranes for photoelectrochemical cells

    E-Print Network [OSTI]

    Davis, Nicole R. (Nicole Rose)

    2014-01-01T23:59:59.000Z

    Spray-assisted layer-by-layer (Spray-LbL) assembly is used to achieve vertical transfer of silicon microwire arrays into an ion-conducting, ultrathin polymer membrane. The choice of LbL platform and the properties of the ...

  20. Atomic Layer-by-Layer Thermoelectric Conversion in Topological Insulator Bismuth/Antimony Tellurides

    E-Print Network [OSTI]

    Jo, Moon-Ho

    Supporting Information ABSTRACT: Material design for direct heat-to-electricity conversion with substantial that the thermoelectric conversion can be interiorly achieved at the atomic steps of a homogeneous medium by directAtomic Layer-by-Layer Thermoelectric Conversion in Topological Insulator Bismuth

  1. A Micellar Route to Layer-by-Layer Assembly of Hydrophobic Functional Polymers

    E-Print Network [OSTI]

    Zhao, Yue

    A Micellar Route to Layer-by-Layer Assembly of Hydrophobic Functional Polymers Qi Bo, Xia Tong, Yi, 2008 ABSTRACT: We demonstrate a general approach to introduce hydrophobic functional polymers-chain liquid crystalline polymer (SCLCP) were synthesized using atom transfer radical polymerization, followed

  2. Polyvalent surface modification of hydrocarbon polymers via covalent layer-by-layer self-assembly

    E-Print Network [OSTI]

    Liao, Kang-Shyang

    2009-05-15T23:59:59.000Z

    Layer-by-layer (LbL) assembly based on ionic interactions has proven to be a versatile route for surface modification and construction of ultrathin nanocomposites. Covalent LbL assembly based on facile ‘click’ covalent bond formation is an effective...

  3. Layer-by-layer assembly of electrically conductive polymer thin films

    E-Print Network [OSTI]

    Jan, Chien Sy Jason

    2007-09-17T23:59:59.000Z

    Layer-by-layer (LbL) assembly was used to produce highly conductive thin films with carbon black (CB) and polyelectrolytes. The effects of sonication and pHadjustment of the deposition mixtures on the conductivity and transparency of deposited films...

  4. 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...

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. A simplex model for layered niche networks

    E-Print Network [OSTI]

    P. Fraundorf

    2007-03-06T23:59:59.000Z

    The standing crop of correlations in metazoan communities may be assessed by an inventory of niche structures focused inward and outward from the physical boundaries of skin (self), gene-pool (family), and meme-pool (culture). We consider tracking the progression from three and four correlation layers in many animal communities, to five of six layers for the shared adaptation of most humans, with an attention-slice model that maps the niche-layer focus of individuals onto the 6-variable space of a 5-simplex. The measure puts questions about the effect, on culture and species, of policy and natural events into a common context, and may help explore the impact of electronically-mediated codes on community health.

  10. Growth of oxide exchange bias layers

    DOE Patents [OSTI]

    Chaiken, A.; Michel, R.P.

    1998-07-21T23:59:59.000Z

    An oxide (NiO, CoO, NiCoO) antiferromagnetic exchange bias layer produced by ion beam sputtering of an oxide target in pure argon (Ar) sputtering gas, with no oxygen gas introduced into the system. Antiferromagnetic oxide layers are used, for example, in magnetoresistive readback heads to shift the hysteresis loops of ferromagnetic films away from the zero field axis. For example, NiO exchange bias layers have been fabricated using ion beam sputtering of an NiO target using Ar ions, with the substrate temperature at 200 C, the ion beam voltage at 1000V and the beam current at 20 mA, with a deposition rate of about 0.2 {angstrom}/sec. The resulting NiO film was amorphous. 4 figs.

  11. Chromatic control in coextruded layered polymer microlenses

    E-Print Network [OSTI]

    Crescimanno, Michael; Andrews, James H; Zhou, Chuanhong; Petrus, Joshua B; Merlo, Cory; Bagheri, Cameron; Hetzel, Connor; Tancabel, James; Singer, Kenneth D; Baer, Eric

    2015-01-01T23:59:59.000Z

    We describe the formation, characterization and theoretical understanding of microlenses comprised of alternating polystyrene and polymethylmethacrylate layers produced by multilayer coextrusion. These lenses are fabricated by photolithography, using a grayscale mask followed by plasma etching, so that the refractive index alternation of the bilayer stack appears across the radius of the microlens. The alternating quarter-wave thick layers form a one-dimensional photonic crystal whose dispersion augments the material dispersion, allowing one to sculpt the chromatic dispersion of the lens by adjusting the layered structure. Using Huygen's principle, we model our experimental measurements of the focal length of these lenses across the reflection band of the multilayer polymer film from which the microlens is fashioned. For a 56 micron diameter multilayered lens of focal length 300 microns, we measured a nearly 25 percent variation in the focal length across a shallow, 50 nm-wide reflection band.

  12. EXPERIMENTAL STUDY OF COMBUSTION IN A TURBULENT BOUNDARY LAYER

    E-Print Network [OSTI]

    Cheng, R.K.

    2011-01-01T23:59:59.000Z

    evaporation, but the thermophoretic migration of particlesboundary layer due to thermophoretic motion and evaporation

  13. Double layer field shaping systems for toroidal plasmas

    DOE Patents [OSTI]

    Ohyabu, Nobuyoshi (La Jolla, CA)

    1982-01-01T23:59:59.000Z

    Methods and apparatus for plasma generation, confinement and control such as Tokamak plasma systems are described having a two layer field shaping coil system comprising an inner coil layer close to the plasma and an outer coil layer to minimize the current in the inner coil layer.

  14. LVT: A Layered Verification Technique for Distributed Computing Systems

    E-Print Network [OSTI]

    Olsson, Ron

    LVT: A Layered Verification Technique for Distributed Computing Systems Cui Zhang ? , Brian R of distributed computing systems with multiple component layers. Each lower layer in such a system provides languages as interfaces of systems, LVT treats each layer in a distributed computing system as a distributed

  15. Numerical Simulation of the Wave Bottom Boundary Layer

    E-Print Network [OSTI]

    Slinn, Donald

    boundary layer. Oscillatory boundary layers are examined using a high-resolution time-dependent threeNumerical Simulation of the Wave Bottom Boundary Layer Over a Smooth Surface. Part 1: Three for turbulent boundary layers that occur over a smooth bottom. Results indicate that turbulence levels

  16. Pd/Ni-WO3 anodic double layer gasochromic device

    DOE Patents [OSTI]

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland; Liu, Ping

    2004-04-20T23:59:59.000Z

    An anodic double layer gasochromic sensor structure for optical detection of hydrogen in improved response time and with improved optical absorption real time constants, comprising: a glass substrate; a tungsten-doped nickel oxide layer coated on the glass substrate; and a palladium layer coated on the tungsten-doped nickel oxide layer.

  17. 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.

  18. Fusion Utility in the Knudsen Layer

    SciTech Connect (OSTI)

    Davidovits, Seth [PPPL; Fisch, Nathaniel J. [PPPL

    2014-08-01T23:59:59.000Z

    In inertial confi#12;nement fusion, the loss of fast ions from the edge of the fusing hot-spot region reduces the reactivity below its Maxwellian value. The loss of fast ions may be pronounced because of the long mean free paths of fast ions, compared to those of thermal ions. We introduce a fusion utility function to demonstrate essential features of this Knudsen layer e#11;ffect, in both magnetized and unmagnetized cases. The fusion utility concept is also used to evaluate restoring the reactivity in the Knudsen layer by manipulating fast ions in phase space using waves.

  19. Fusion utility in the Knudsen layer

    SciTech Connect (OSTI)

    Davidovits, Seth; Fisch, Nathaniel J. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08544 (United States)

    2014-09-15T23:59:59.000Z

    In inertial confinement fusion, the loss of fast ions from the edge of the fusing hot-spot region reduces the reactivity below its Maxwellian value. The loss of fast ions may be pronounced because of the long mean free paths of fast ions, compared with those of thermal ions. We introduce a fusion utility function to demonstrate essential features of this Knudsen layer effect, in both magnetized and unmagnetized cases. The fusion utility concept is also used to evaluate the restoring reactivity in the Knudsen layer by manipulating fast ions in phase space using waves.

  20. Energetic particle acceleration in shear layers

    E-Print Network [OSTI]

    M. Ostrowski

    1999-11-05T23:59:59.000Z

    A plasma velocity shear layer and/or a tangential flow discontinuity provide conditions allowing for energetic particle acceleration. We review such acceleration processes acting both in non-relativistic and in relativistic flows. In heliospheric conditions shear layers can provide particles with energies compatible with the observed values (from several keV up to MeV), while in relativistic extragalactic jets proton energies even in excess of 10^{19} eV can be obtained. Application of the discussed theory to particular astrophysical objects is severely limited by inadequate knowledge of local physical conditions.

  1. Photovoltaic cell with thin CS layer

    DOE Patents [OSTI]

    Jordan, John F. (El Paso, TX); Albright, Scot P. (El Paso, TX)

    1994-01-18T23:59:59.000Z

    An improved photovoltaic panel and method of forming a photovoltaic panel are disclosed for producing a high efficiency CdS/CdTe photovoltaic cell. The photovoltaic panel of the present invention is initially formed with a substantially thick Cds layer, and the effective thickness of the CdS layer is substantially reduced during regrowth to both form larger diameter CdTe crystals and substantially reduce the effective thickness of the C This invention was made with Government support under Subcontract No. ZL-7-06031-3 awarded by the Department of Energy. The Government has certain rights in this invention.

  2. Back contact buffer layer for thin-film solar cells

    DOE Patents [OSTI]

    Compaan, Alvin D.; Plotnikov, Victor V.

    2014-09-09T23:59:59.000Z

    A photovoltaic cell structure is disclosed that includes a buffer/passivation layer at a CdTe/Back contact interface. The buffer/passivation layer is formed from the same material that forms the n-type semiconductor active layer. In one embodiment, the buffer layer and the n-type semiconductor active layer are formed from cadmium sulfide (CdS). A method of forming a photovoltaic cell includes the step of forming the semiconductor active layers and the buffer/passivation layer within the same deposition chamber and using the same material source.

  3. Thin film solar cell including a spatially modulated intrinsic layer

    DOE Patents [OSTI]

    Guha, Subhendu (Troy, MI); Yang, Chi-Chung (Troy, MI); Ovshinsky, Stanford R. (Bloomfield Hills, MI)

    1989-03-28T23:59:59.000Z

    One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness, said graded portion including a region removed from the intrinsic layer-dopant layer interfaces. The band gap of the intrinsic layer is always less than the band gap of the doped layers. The gradation of the intrinsic layer is effected such that the open circuit voltage and/or the fill factor of the one or plural solar cell structure is enhanced.

  4. Conductive layer for biaxially oriented semiconductor film growth

    DOE Patents [OSTI]

    Findikoglu, Alp T. (Los Alamos, NM); Matias, Vladimir (Santa Fe, NM)

    2007-10-30T23:59:59.000Z

    A conductive layer for biaxially oriented semiconductor film growth and a thin film semiconductor structure such as, for example, a photodetector, a photovoltaic cell, or a light emitting diode (LED) that includes a crystallographically oriented semiconducting film disposed on the conductive layer. The thin film semiconductor structure includes: a substrate; a first electrode deposited on the substrate; and a semiconducting layer epitaxially deposited on the first electrode. The first electrode includes a template layer deposited on the substrate and a buffer layer epitaxially deposited on the template layer. The template layer includes a first metal nitride that is electrically conductive and has a rock salt crystal structure, and the buffer layer includes a second metal nitride that is electrically conductive. The semiconducting layer is epitaxially deposited on the buffer layer. A method of making such a thin film semiconductor structure is also described.

  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. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.}

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. Physical-Layer Security Alexandra Filip

    E-Print Network [OSTI]

    Henkel, Werner

    Physical-Layer Security by Alexandra Filip A thesis for conferral of a Master of Science the bit-error ratio (BER). Secondly, the focus is placed on blind beamforming algorithms, techniques investigate how fast and accurate an eavesdropper can obtain the data as a result of blind beamforming

  18. Functional Data Analysis With Multi Layer Perceptrons

    E-Print Network [OSTI]

    Fleuret, François

    Analysis. We introduce a computation model for functional input data and we show that this model is a wellFunctional Data Analysis With Multi Layer Perceptrons Fabrice Rossi , Brieuc Conan-Guez and Fran as clas- sical multivariate data, because they are in general de- scribed by a finite set of input

  19. Planetary Boundary Layer from AERI and MPL

    SciTech Connect (OSTI)

    Sawyer, Virginia

    2014-02-13T23:59:59.000Z

    The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

  20. Planetary Boundary Layer from AERI and MPL

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Sawyer, Virginia

    The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

  1. Nano-soldering to single atomic layer

    DOE Patents [OSTI]

    Girit, Caglar O. (Berkeley, CA); Zettl, Alexander K. (Kensington, CA)

    2011-10-11T23:59:59.000Z

    A simple technique to solder submicron sized, ohmic contacts to nanostructures has been disclosed. The technique has several advantages over standard electron beam lithography methods, which are complex, costly, and can contaminate samples. To demonstrate the soldering technique graphene, a single atomic layer of carbon, has been contacted, and low- and high-field electronic transport properties have been measured.

  2. Quantitative methods for Regulatory control layer selection

    E-Print Network [OSTI]

    Skogestad, Sigurd

    and the method is evaluated on two distillation column case studies with one, two or more closed loops. Keywords, a single multivariable controller (e.g. using MPC with no lower-layer PID controllers) would be optimal into the MPC design, so tuning would become Corresponding author address. Tel: +47 73 59 41 54; fax: +47 73 59

  3. Double layer capacitor prospects look good

    SciTech Connect (OSTI)

    NONE

    1995-07-01T23:59:59.000Z

    The Fourth International Seminar in Double Layer Capacitors and similar energy devices has been sponsored again by Dr. S.P. Wolsky and Dr. Nikola Marincic. The seminar was held in December 1994, at Deerfield Beach, FL. This report provides a brief description of information on supercapacitors.

  4. Intrusive gravity currents in two-layer

    E-Print Network [OSTI]

    Flynn, Morris R.

    Intrusive gravity currents in two-layer stratified media Morris R. Flynn & Paul F. Linden Dept.avalanche.org/pictures #12;· `Microbursts' pose a non-trivial threat to airplane safety Introduction Impacts on human health;· Whereas gravity currents travel along a solid boundary, intrusive gravity currents or intrusions propagate

  5. Synthesis of a Cationic Inorganic Layered Material for Trapping Anionic Pharmaceutical Pollutants

    E-Print Network [OSTI]

    Sergo, Kevin Michael

    2013-01-01T23:59:59.000Z

    CRUZ SYNTHESIS OF A CATIONIC INORGANIC LAYERED MATERIAL FORAbstract Synthesis of a Cationic Inorganic Layered Material

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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).

  16. 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.

  17. 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.

  18. Layer-by-layer Assembly of Nanobrick Wall Ultrathin Transparent Gas Barrier Films 

    E-Print Network [OSTI]

    Priolo, Morgan Alexander

    2012-07-16T23:59:59.000Z

    Thin layers with high barrier to oxygen and other gases are a key component to many packaging applications, such as flexible electronics, food, and pharmaceuticals. Vapor deposited thin films provide significant gas barrier, but are prone...

  19. Layer-by-layer Assembly of Nanobrick Wall Ultrathin Transparent Gas Barrier Films

    E-Print Network [OSTI]

    Priolo, Morgan Alexander

    2012-07-16T23:59:59.000Z

    to cracking when flexed, require special, non-ambient processing environments, and can involve complex fabrication when layered with polymers. The addition of clay into polymers can enhance barrier properties relative to the neat polymer; however...

  20. Elastodynamic behavior of the three dimensional layer-by-layer metamaterial structure

    SciTech Connect (OSTI)

    Aravantinos-Zafiris, N.; Sigalas, M. M. [Department of Materials Science, University of Patras, 26504 Patras (Greece); Economou, E. N. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology—Hellas (FORTH), P.O. Box 1385, Heraklion GR-71110, Greece and Department of Physics, University of Crete, Heraklion GR-71003 (Greece)

    2014-10-07T23:59:59.000Z

    In this work, we numerically investigate for the first time the elastodynamic behavior of a three dimensional layer-by-layer rod structure, which is easy to fabricate and has already proved to be very efficient as a photonic crystal. The Finite Difference Time Domain method was used for the numerical calculations. For the rods, several materials were examined and the effects of all the geometric parameters of the structure were also numerically investigated. Additionally, two modifications of the structure were included in our calculations. The results obtained here (for certain geometric parameters), exhibiting a high ratio of longitudinal over transverse sound velocity and therefore a close approach to ideal pentamode behavior over a frequency range, clearly show that the layer-by-layer rod structure, besides being an efficient photonic crystal, is a very serious contender as an elastodynamic metamaterial.

  1. Buried layer/connecting layer high energy implantation for improved CMOS latch-up

    SciTech Connect (OSTI)

    Morris, W. [Silicon Engineering, Austin, TX (United States); Rubin, L. [Eaton Corporation, Beverly, MA (United States); Wristers, D. [Advanced Micro Devices, Austin, TX (United States)

    1996-12-31T23:59:59.000Z

    An integrated P-Buried Layer formed by MeV ion implantation combined with a localized P-Connecting Layer has been studied for latch-up isolation improvements for advanced CMOS technology. Latch-up trigger currents have been characterized with regards to buried layer dose/energy, connecting layer dose/energy, and n-well retrograde dose. Simulation results confirmed by data indicate that P+ injection trigger currents > 450 {mu}A/{mu}m can be achieved by utilizing certain combinations of B.L./C.L. and n-well retrograde doses for n+/p+ spacings = 2.0{mu}m. The B.L./C.L. process architecture shows great promise for providing an alternative isolation technique for latch-up improvement that is easy to implement, and for eliminating the dependence on epi silicon for latch-up control.

  2. The Effect of Nanoparticles on the Thermal Transitions of Hydrated Layer-by-Layer Assemblies

    E-Print Network [OSTI]

    Puhr, Joseph Timothy

    2014-04-25T23:59:59.000Z

    ). 27 Figure 9. The various film configurations studied in this work. Parts a), c), and e) correspond to films incorporating SiO2 nanospheres, while parts b), d), and f) correspond to films incorporating LAP nanoplatelets. Polyethyleneimine... the nanospheres slowly embedding themselves in the film, thereby leading to film densification. SiO2 embedment in a PDAC layer is not an unusual phenomenon, being previously observed by Xu et al. [49]. In their experiments a single layer of PDAC was deposited...

  3. High thermal conductivity lossy dielectric using a multi layer configuration

    DOE Patents [OSTI]

    Tiegs, Terry N. (Lenoir City, TN); Kiggans, Jr., James O. (Oak Ridge, TN)

    2003-01-01T23:59:59.000Z

    Systems and methods are described for loss dielectrics. A loss dielectric includes at least one high dielectric loss layer and at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. A method of manufacturing a loss dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. The systems and methods provide advantages because the loss dielectrics are less costly and more environmentally friendly than the available alternatives.

  4. Turbulent Fluxes in Stably Stratified Boundary Layers

    E-Print Network [OSTI]

    L'vov, Victor S; Rudenko, Oleksii; 10.1088/0031-8949/2008/T132/014010

    2008-01-01T23:59:59.000Z

    We present an extended version of an invited talk given on the International Conference "Turbulent Mixing and Beyond". The dynamical and statistical description of stably stratified turbulent boundary layers with the important example of the stable atmospheric boundary layer in mind is addressed. Traditional approaches to this problem, based on the profiles of mean quantities, velocity second-order correlations, and dimensional estimates of the turbulent thermal flux run into a well known difficulty, predicting the suppression of turbulence at a small critical value of the Richardson number, in contradiction with observations. Phenomenological attempts to overcome this problem suffer from various theoretical inconsistencies. Here we present an approach taking into full account all the second-order statistics, which allows us to respect the conservation of total mechanical energy. The analysis culminates in an analytic solution of the profiles of all mean quantities and all second-order correlations removing t...

  5. Atomic Layer Deposition for SRF Cavities

    SciTech Connect (OSTI)

    Norem, J; Pellin, M J; Antoine, C Z; Ciovati, G; Kneisel, P; Reece, C E; Rimmer, R A; Cooley, L; Gurevich, A V; Ha, Y; Proslier, Th

    2009-05-01T23:59:59.000Z

    We have begun using Atomic Layer Deposition (ALD) to synthesize a variety of surface coatings on coupons and cavities as part of an effort to produce rf structures with significantly better performance and yield than those obtained from bulk niobium, The ALD process offers the possibility of conformally coating complex cavity shapes with precise layered structures with tightly constrained morphology and chemical properties. Our program looks both at the metallurgy and superconducting properties of these coatings, and also their performance in working structures. Initial results include: 1) evidence from point contact tunneling showing magnetic oxides can be a significant limitation to high gradient operation, 2) experimental results showing the production sharp niobium/oxide interfaces from a high temperature bake of ALD coated Al2O3 on niobium surfaces, 3) results from ALD coated structures.

  6. Atomic Layer Deposition for SRF Cavities

    SciTech Connect (OSTI)

    Proslier, Th.; Ha, Y.; Zasadzinski, J.; /IIT, Chicago; Ciovati, G.; Kneissel, P.; Reece, C.; Rimmer, R.; /Jefferson Lab; Gurevich, A.; /Natl. High Mag. Field Lab.; Cooley, L.; Wu, G.; /Fermilab; Pellin, M.; /Argonne

    2009-05-01T23:59:59.000Z

    We have begun using Atomic Layer Deposition (ALD) to synthesize a variety of surface coatings on coupons and cavities as part of an effort to produce rf structures with significantly better performance and yield than those obtained from bulk niobium, The ALD process offers the possibility of conformally coating complex cavity shapes with precise layered structures with tightly constrained morphology and chemical properties. Our program looks both at the metallurgy and superconducting properties of these coatings, and also their performance in working structures. Initial results include: (1) results from ALD coated cavities and coupons, (2) new evidence from point contact tunneling (PCT) showing magnetic oxides can be a significant limitation to high gradient operation, (3) a study of high pressure rinsing damage on niobium samples.

  7. Analysis of the Younger Dryas Impact Layer

    SciTech Connect (OSTI)

    Firestone, Richard B.; West, Allen; Revay, Zsolt; Hagstrum, Jonathon T,; Belgya, Thomas; Hee, Shane S. Que; Smith, Alan R.

    2010-02-27T23:59:59.000Z

    We have uncovered a thin layer of magnetic grains and microspherules, carbon spherules, and glass-like carbon at nine sites across North America, a site in Belgium, and throughout the rims of 16 Carolina Bays. It is consistent with the ejecta layer from an impact event and has been dated to 12.9 ka BP coinciding with the onset of Younger Dryas (YD) cooling and widespread megafaunal extinctions in North America. At many locations the impact layer is directly below a black mat marking the sudden disappearance of the megafauna and Clovis people. The distribution pattern of the Younger Dryas boundary (YDB) ejecta layer is consistent with an impact near the Great Lakes that deposited terrestrial-like ejecta near the impact site and unusual, titanium-rich projectile-like ejecta further away. High water content associated with the ejecta, up to 28 at. percent hydrogen (H), suggests the impact occurred over the Laurentide Ice Sheet. YDB microspherules and magnetic grains are highly enriched in TiO{sub 2}. Magnetic grains from several sites are enriched in iridium (Ir), up to 117 ppb. The TiO{sub 2}/FeO, K/Th, TiO{sub 2}/Zr, Al{sub 2}O{sub 3}/FeO+MgO, CaO/Al{sub 2}O{sub 3}, REE/ chondrite, FeO/MnO ratios and SiO{sub 2}, Na{sub 2}O, K{sub 2}O, Cr{sub 2}O{sub 3}, Ni, Co, U, Th and other trace element abundances are inconsistent with all terrestrial and extraterrestrial (ET) sources except for KREEP, a lunar igneous rock rich in potassium (K), rare-earth elements (REE), phosphorus (P), and other incompatible elements including U and Th. Normal Fe, Ti, and {sup 238}U/{sup 235}U isotopic abundances were found in the magnetic grains, but {sup 234}U was enriched over equilibrium values by 50 percent in Murray Springs and by 130 percent in Belgium. 40K abundance is enriched by up to 100 percent in YDB sediments and Clovis chert artifacts. Highly vesicular carbon spherules containing nanodiamonds, glass-like carbon, charcoal and soot found in large quantities in the YDB layer are consistent with an impact followed by intense burning. Four holes in the Great Lakes, some deeper than Death Valley, are proposed as possible craters produced by the airburst breakup of a loosely aggregated projectile.

  8. Design and Implementation of Physical Layer Network Coding Protocols

    E-Print Network [OSTI]

    Maduike, Dumezie K.

    2010-10-12T23:59:59.000Z

    There has recently been growing interest in using physical layer network coding techniques to facilitate information transfer in wireless relay networks. The physical layer network coding technique takes advantage of the additive nature of wireless...

  9. Formation Of The Spinel Phase In The Layered Composite Cathode...

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

    Of The Spinel Phase In The Layered Composite Cathode Used In Li-Ion Batteries. Formation Of The Spinel Phase In The Layered Composite Cathode Used In Li-Ion Batteries. Abstract:...

  10. auroral double layers: Topics by E-print Network

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

    Layer Gilles the flow of a viscous fluid around a thin layer of porous material. Using a BKW method, we perform an asymptotic expansion of the solution when a little parameter,...

  11. Soil Insulation For Barrier Layer Protection In Landfill Covers

    E-Print Network [OSTI]

    Gregory Smith Roy

    Landfill covers are designed to isolate waste from the environment by incorporating low-permeability barrier layers. The barrier layer minimizes and controls gas escaping from the waste and the amount of infiltrating moisture available for leachate generation. Barrier layers are typically designed and constructed of a thick layer of compacted fine-grain native soil material or a manufactured geosynthetic clay liner. The barrier layer must be protected from frost damage. Freezing of a compacted soil layer has been shown to cause quick and irreversible degradation. Large increases in permeability have been demonstrated in compacted clay barriers subjected to a minimum number of freezing and thawing cycles. Design methods to protect the barrier layer from frost damage have not been addressed in the research literature. A design procedure is addressed in this paper that determines the thickness of soil required to protect a barrier layer. The procedure is based on sitespecific temperature ...

  12. Effect of Gallium Nitride Template Layer Strain on the Growth...

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

    Gallium Nitride Template Layer Strain on the Growth of InxGa1-xNGaN Multiple Quantum Well Light Emitting Diodes. Effect of Gallium Nitride Template Layer Strain on the Growth of...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Turbulent transport across shear layers in magnetically confined plasmas

    SciTech Connect (OSTI)

    Nold, B.; Ramisch, M. [Institut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, D-70569 Stuttgart (Germany); Manz, P.; Birkenmeier, G. [Physik-Department E28, Technische Universität München, James-Franck-Str.1, D-85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Ribeiro, T. T.; Müller, H. W.; Scott, B. D. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Fuchert, G. [IJL, Université de Lorraine, CNRS (UMR 7198), BP 40239 Vandoeuvre-lès-Nancy (France); Stroth, U. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); Physik-Department E28, Technische Universität München, James-Franck-Str.1, D-85748 Garching (Germany)

    2014-10-15T23:59:59.000Z

    Shear layers modify the turbulence in diverse ways and do not only suppress it. A spatial-temporal investigation of gyrofluid simulations in comparison with experiments allows to identify further details of the transport process across shear layers. Blobs in and outside a shear layer merge, thereby exchange particles and heat and subsequently break up. Via this mechanism particles and heat are transported radially across shear layers. Turbulence spreading is the immanent mechanism behind this process.

  4. Synthesis and Characterization of Few Layer Semiconducting Transition Metal Dichalcogenides

    E-Print Network [OSTI]

    Mann, John Calif

    2013-01-01T23:59:59.000Z

    preparation of single layer films by laser-based thinning,[26] plasma thinning,[27] liquid exfoliation,[28-31] graphene

  5. Modelling of fatigue crack tunneling and delamination in layered composites

    E-Print Network [OSTI]

    Fleck, Norman A.

    and GLARE are laminates consisting of an alternating stack of aluminium alloy sheets and fibre­epoxy layers

  6. A Layered Approach to Complex Negotiations Xiaoqin Zhang

    E-Print Network [OSTI]

    Zhang, Xiaoqin

    Honeywell Laboratories Tom.Wagner@honeywell.com May 17, 2004 Abstract In this paper, we present a layered

  7. 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.

  8. 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}.

  9. Love wave propagation in layered magneto-electro-elastic structures

    E-Print Network [OSTI]

    Wang, Ji

    Love wave propagation in layered magneto-electro-elastic structures with initial stress J. Du, X that the initial stress has an important effect on the Love wave propagation in layered piezomagnetic at their interface. He concluded that shear surface waves propagate in the layer and attenuate along the thickness

  10. Evolution of the layers in a subsumption architecture robot controller

    E-Print Network [OSTI]

    Togelius, Julian

    Evolution of the layers in a subsumption architecture robot controller Julian Togelius Dissertation julian@togelius.com +46-705-192088 #12;2 Abstract An approach to robotics called layered evolution. The evolvability and performance of layered evolution on this task is compared to (standard) monolithic evolution

  11. Effective anomalous Hall coefficient in an ultrathin Co layer sandwiched by Pt layers

    SciTech Connect (OSTI)

    Zhang, Peng; Wu, Di; Jiang, Zhengsheng; Sang, Hai, E-mail: weiwei.lin@u-psud.fr, E-mail: haisang@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Lin, Weiwei, E-mail: weiwei.lin@u-psud.fr, E-mail: haisang@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Institut d'Electronique Fondamentale, Université Paris-Sud, Orsay 91405 (France)

    2014-02-14T23:59:59.000Z

    Anomalous Hall effect in Co/Pt multilayer is important to study the effect of interface with strong spin-orbit coupling. However, the shunting effect of the layers in such system and the circuit in the plane perpendicular to the injected current were overlooked in most works and thus, anomalous Hall coefficient in Co/Pt multilayer has not been determined accurately. Considering the shunting effect and the equivalent circuit, we show that the effective anomalous Hall coefficient of a 0.5?nm thick Co layer sandwiched by Pt layers R{sub S} is 0.29?±?0.01????cm/T at the zero temperature limit and increases to about 0.73????cm/T at the temperature of 300?K. R{sub S} is one order larger than that in bulk Co film, indicating the large contribution of the Co/Pt interface. R{sub S} increases with the resistivity of Co as well as a resistivity independent contribution of ?0.23?±?0.01????cm/T. The equivalent anomalous Hall current in the Co layer has a maximum of 1.1% of the injected transverse current in the Co layer around the temperature of 80?K.

  12. 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.

  13. Mechanical and Transport Properties of Layer-by-Layer Electrospun Composite Proton Exchange Membranes for Fuel Cell Applications

    E-Print Network [OSTI]

    Mannarino, Matthew M.

    Composite membranes composed of highly conductive and selective layer-by-layer (LbL) films and electrospun fiber mats were fabricated and characterized for mechanical strength and electrochemical selectivity. The LbL ...

  14. Layer-by-layer assembled carbon nanotube nanostructures for high-power and high-energy lithium storage

    E-Print Network [OSTI]

    Gallant, Betar M. (Betar Maurkah)

    2010-01-01T23:59:59.000Z

    The layer-by-layer (LbL) electrostatic assembly technique is utilized to incorporate positively- and negatively-charged electroactive species in self-assembled electrodes that are binder- and additive- free. This work first ...

  15. Scalable Manufacture of Built-to-Order Nanomedicine: Spray-Assisted Layer-by-Layer Functionalization of PRINT Nanoparticles

    E-Print Network [OSTI]

    Herlihy, Kevin P.

    Scalable methods, PRINT particle fabrication, and spray-assisted Layer-by-Layer deposition are combined to generate uniform and functional nanotechnologies with precise control over composition, size, shape, and surface ...

  16. 2007 Raj JainCSE571SWashington University in St. Louis Secure Socket Layer (SSL)Secure Socket Layer (SSL)

    E-Print Network [OSTI]

    Jain, Raj

    15-1 ©2007 Raj JainCSE571SWashington University in St. Louis Secure Socket Layer (SSL)Secure Socket Layer (SSL) and Transport Layerand Transport Layer Security (TLS)Security (TLS) Raj Jain Washington in St. Louis OverviewOverview History and overview of SSL/TLS Products and Implementations Datagram

  17. 2009 Raj JainCSE571SWashington University in St. Louis Secure Socket Layer (SSL)Secure Socket Layer (SSL)

    E-Print Network [OSTI]

    Jain, Raj

    15-1 ©2009 Raj JainCSE571SWashington University in St. Louis Secure Socket Layer (SSL)Secure Socket Layer (SSL) and Transport Layerand Transport Layer Security (TLS)Security (TLS) Raj Jain Washington in St. Louis OverviewOverview History and overview of SSL/TLS Products and Implementations Datagram

  18. Engineering Glass Passivation Layers -Model Results

    SciTech Connect (OSTI)

    Skorski, Daniel C.; Ryan, Joseph V.; Strachan, Denis M.; Lepry, William C.

    2011-08-08T23:59:59.000Z

    The immobilization of radioactive waste into glass waste forms is a baseline process of nuclear waste management not only in the United States, but worldwide. The rate of radionuclide release from these glasses is a critical measure of the quality of the waste form. Over long-term tests and using extrapolations of ancient analogues, it has been shown that well designed glasses exhibit a dissolution rate that quickly decreases to a slow residual rate for the lifetime of the glass. The mechanistic cause of this decreased corrosion rate is a subject of debate, with one of the major theories suggesting that the decrease is caused by the formation of corrosion products in such a manner as to present a diffusion barrier on the surface of the glass. Although there is much evidence of this type of mechanism, there has been no attempt to engineer the effect to maximize the passivating qualities of the corrosion products. This study represents the first attempt to engineer the creation of passivating phases on the surface of glasses. Our approach utilizes interactions between the dissolving glass and elements from the disposal environment to create impermeable capping layers. By drawing from other corrosion studies in areas where passivation layers have been successfully engineered to protect the bulk material, we present here a report on mineral phases that are likely have a morphological tendency to encrust the surface of the glass. Our modeling has focused on using the AFCI glass system in a carbonate, sulfate, and phosphate rich environment. We evaluate the minerals predicted to form to determine the likelihood of the formation of a protective layer on the surface of the glass. We have also modeled individual ions in solutions vs. pH and the addition of aluminum and silicon. These results allow us to understand the pH and ion concentration dependence of mineral formation. We have determined that iron minerals are likely to form a complete incrustation layer and we plan to look more closely at Vivianite [Fe3(PO4)2-8(H2O)] and Siderite [FeCO3] in the next stage of the project.

  19. Layered zeolite materials and methods related thereto

    DOE Patents [OSTI]

    Tsapatsis, Michael; Maheshwari, Sudeep; Bates, Frank S; Koros, William J

    2013-08-06T23:59:59.000Z

    A novel oxide material (MIN-I) comprising YO.sub.2; and X.sub.2O.sub.3, wherein Y is a tetravalent element and X is a trivalent element, wherein X/Y=O or Y/X=30 to 100 is provided. Surprisingly, MIN-I can be reversibly deswollen. MIN-I can further be combined with a polymer to produce a nanocomposite, depolymerized to produce predominantly fully exfoliated layers (MIN-2), and pillared to produce a pillared oxide material (MIN-3), analogous to MCM-36. The materials are useful in a wide range of applications, such as catalysts, thin films, membranes, and coatings.

  20. Ruthenium / aerogel nanocomposits via Atomic Layer Deposition

    SciTech Connect (OSTI)

    Biener, J; Baumann, T F; Wang, Y; Nelson, E J; Kucheyev, S O; Hamza, A V; Kemell, M; Ritala, M; Leskela, M

    2006-08-28T23:59:59.000Z

    We present a general approach to prepare metal/aerogel nanocomposites via template directed atomic layer deposition (ALD). In particular, we used a Ru ALD process consisting of alternating exposures to bis(cyclopentadienyl)ruthenium (RuCp{sub 2}) and air at 350 C to deposit metallic Ru nanoparticles on the internal surfaces of carbon and silica aerogels. The process does not affect the morphology of the aerogel template and offers excellent control over metal loading by simply adjusting the number of ALD cycles. We also discuss the limitations of our ALD approach, and suggest ways to overcome these.

  1. Rateless Codes with Progressive Recovery for Layered Multimedia Delivery

    E-Print Network [OSTI]

    Chen, Zhao; Xu, Mai; Lu, Jianhua

    2012-01-01T23:59:59.000Z

    This paper proposes a novel approach, based on unequal error protection, to enhance rateless codes with progressive recovery for layered multimedia delivery. With a parallel encoding structure, the proposed Progressive Rateless codes (Pro-Rateless) assign unequal redundancy to each layer in accordance with their importance. Each output symbol contains information from all layers, and thus the stream layers can be recovered progressively at the expected received ratios of output symbols. Furthermore, the dependency between layers is naturally considered. The performance of the Pro-Rateless is evaluated and compared with some related UEP approaches. Results show that our Pro-Rateless approach provides better performance both theoretically and numerically.

  2. Method of forming buried oxide layers in silicon

    DOE Patents [OSTI]

    Sadana, Devendra Kumar (Pleasantville, NY); Holland, Orin Wayne (Lenoir City, TN)

    2000-01-01T23:59:59.000Z

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  3. Buffer layers for REBCO films for use in superconducting devices

    SciTech Connect (OSTI)

    Goyal, Amit; Wee, Sung-Hun

    2014-06-10T23:59:59.000Z

    A superconducting article includes a substrate having a biaxially textured surface. A biaxially textured buffer layer, which can be a cap layer, is supported by the substrate. The buffer layer includes a double perovskite of the formula A.sub.2B'B''O.sub.6, where A is rare earth or alkaline earth metal and B' and B'' are different transition metal cations. A biaxially textured superconductor layer is deposited so as to be supported by the buffer layer. A method of making a superconducting article is also disclosed.

  4. Conductive and robust nitride buffer layers on biaxially textured substrates

    DOE Patents [OSTI]

    Sankar, Sambasivan [Chicago, IL; Goyal, Amit [Knoxville, TN; Barnett, Scott A [Evanston, IL; Kim, Ilwon [Skokie, IL; Kroeger, Donald M [Knoxville, TN

    2009-03-31T23:59:59.000Z

    The present invention relates to epitaxial, electrically conducting and mechanically robust, cubic nitride buffer layers deposited epitaxially on biaxially textured substrates such as metals and alloys. The invention comprises of a biaxially textured substrate with epitaxial layers of nitrides. The invention also discloses a method to form such epitaxial layers using a high rate deposition method as well as without the use of forming gases. The invention further comprises epitaxial layers of oxides on the biaxially textured nitride layer. In some embodiments the article further comprises electromagnetic devices which may have superconducting properties.

  5. Organic photovoltaic cell incorporating electron conducting exciton blocking layers

    DOE Patents [OSTI]

    Forrest, Stephen R.; Lassiter, Brian E.

    2014-08-26T23:59:59.000Z

    The present disclosure relates to photosensitive optoelectronic devices including a compound blocking layer located between an acceptor material and a cathode, the compound blocking layer including: at least one electron conducting material, and at least one wide-gap electron conducting exciton blocking layer. For example, 3,4,9,10 perylenetetracarboxylic bisbenzimidazole (PTCBI) and 1,4,5,8-napthalene-tetracarboxylic-dianhydride (NTCDA) function as electron conducting and exciton blocking layers when interposed between the acceptor layer and cathode. Both materials serve as efficient electron conductors, leading to a fill factor as high as 0.70. By using an NTCDA/PTCBI compound blocking layer structure increased power conversion efficiency is achieved, compared to an analogous device using a conventional blocking layers shown to conduct electrons via damage-induced midgap states.

  6. Combining multi-layered bitmap files using network specific hardware

    DOE Patents [OSTI]

    DuBois, David H. (Los Alamos, NM); DuBois, Andrew J. (Santa Fe, NM); Davenport, Carolyn Connor (Los Alamos, NM)

    2012-02-28T23:59:59.000Z

    Images and video can be produced by compositing or alpha blending a group of image layers or video layers. Increasing resolution or the number of layers results in increased computational demands. As such, the available computational resources limit the images and videos that can be produced. A computational architecture in which the image layers are packetized and streamed through processors can be easily scaled so to handle many image layers and high resolutions. The image layers are packetized to produce packet streams. The packets in the streams are received, placed in queues, and processed. For alpha blending, ingress queues receive the packetized image layers which are then z sorted and sent to egress queues. The egress queue packets are alpha blended to produce an output image or video.

  7. The Deep Layers of Sunspot Umbrae

    E-Print Network [OSTI]

    Stellmacher, Goetz

    2012-01-01T23:59:59.000Z

    We model the deepest observable layers of dark sunspot umbral atmospheres in terms of an empirical model which equally describes observed near infrared continuum intensities and line profiles. We use the umbral continuum intensity at 1.67 nm and the three C I lines at 1,6888, 1,7449 and 1,7456 nm to model the deep layers near the minimum of H- absorption. We find that a radiative equilibrium stratification yields the best compromise between continuum and C I line observations. We determine the effective temperature from the umbral and photospheric flux ratio by down-scaling the monochromatic photospheric flux with the umbral contrast for each frequency. The thus obtained monochromatic umbral flux and the photospheric one are integratied over the whole frequency range, yielding the ratio of total umbral and photospheric flux, which gives 3560 K < T_eff < 3780 K. We assume for our model M3 T_eff=3750 K and fit M3 to the theoretical model by Meyer et al. (1974). Comparison of the model's 'nabla' gradient w...

  8. Electron holography of devices with epitaxial layers

    SciTech Connect (OSTI)

    Gribelyuk, M. A., E-mail: Michael.gribelyuk@globalfoundries.com; Ontalus, V.; Baumann, F. H.; Zhu, Z.; Holt, J. R. [IBM Systems and Technology Group, Hopewell Junction, New York 12533 (United States)

    2014-11-07T23:59:59.000Z

    Applicability of electron holography to deep submicron Si devices with epitaxial layers is limited due to lack of the mean inner potential data and effects of the sample tilt. The mean inner potential V{sub 0}?=?12.75?V of the intrinsic epitaxial SiGe was measured by electron holography in devices with Ge content C{sub Ge}?=?18%. Nanobeam electron diffraction analysis performed on the same device structure showed that SiGe is strain-free in [220] direction. Our results showed good correlation with simulations of the mean inner potential of the strain-free SiGe using density function theory. A new method is proposed in this paper to correct electron holography data for the overlap of potentials of Si and the epitaxial layer, which is caused by the sample tilt. The method was applied to the analysis of the dopant diffusion in p-Field-effect Transistor devices with the identical gate length L?=?30?nm, which had alternative SiGe geometry in the source and drain regions and was subjected to different thermal processing. Results have helped to understand electrical data acquired from the same devices in terms of dopant diffusion.

  9. Thin layer chromatography residue applicator sampler

    DOE Patents [OSTI]

    Nunes, Peter J. (Danville, CA); Kelly, Fredrick R. (Modesto, CA); Haas, Jeffrey S. (San Ramon, CA); Andresen, Brian D. (Livermore, CA)

    2007-07-24T23:59:59.000Z

    A thin layer chromatograph residue applicator sampler. The residue applicator sampler provides for rapid analysis of samples containing high explosives, chemical warfare, and other analyses of interest under field conditions. This satisfied the need for a field-deployable, small, hand-held, all-in-one device for efficient sampling, sample dissolution, and sample application to an analytical technique. The residue applicator sampler includes a sampling sponge that is resistant to most chemicals and is fastened via a plastic handle in a hermetically sealed tube containing a known amount of solvent. Upon use, the wetted sponge is removed from the sealed tube and used as a swiping device across an environmental sample. The sponge is then replaced in the hermetically sealed tube where the sample remains contained and dissolved in the solvent. A small pipette tip is removably contained in the hermetically sealed tube. The sponge is removed and placed into the pipette tip where a squeezing-out of the dissolved sample from the sponge into the pipette tip results in a droplet captured in a vial for later instrumental analysis, or applied directly to a thin layer chromatography plate for immediate analysis.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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...

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. Low-threshold-current-density 1300-nm dilute-nitride quantum well lasers Nelson Tansu,a)

    E-Print Network [OSTI]

    Gilchrist, James F.

    in our earlier studies,3 tensile-strained buffer layers InGaP GaAsP are crucial for achieving highly

  6. 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.

  7. Redox Active Layer-by-Layer Structures containing MnO2 Nanoparticles

    SciTech Connect (OSTI)

    Bazito, Fernanda; O'Brien, Robert; Buttry, Daniel A.

    2005-02-01T23:59:59.000Z

    Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications. This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathode materials in rechargeable Li batteries. Our recent work has focused on synthesizing MnO2 nanoparticles and using these in layer-by-layer (LbL) structures to probe the redox properties of the nanoparticles. We show that the aqueous colloidal nanoparticles produced by butanol reduction of tetramethylammonium permanganate can be trapped in thin films using a layer-by-layer deposition approach, and that these films are both redox active and exhibit kinetically facile electrochemical responses. We show cyclic voltammetry of MnO2 colloidal nanoparticles entrapped in a LbL thin film at an ITO electrode surface using poly(diallyldimethylammonium chloride) (PDDA). CV experiments demonstrate that Li+ insertion accompanies Mn(IV) reduction in LiClO4 supporting electrolytes, and that reduction is hindered in supporting electrolytes containing only tetrabutylammonium cations. We also show that electron propagation through multilayer films is facile, suggesting that electrons percolate through the films via electron exchange between nanoparticles.

  8. Low Cost, Single Layer Replacement for the Back-Sheet and Encapsulant Layers

    SciTech Connect (OSTI)

    Kempe, M. D.; Thapa, P.

    2008-01-01T23:59:59.000Z

    Ethylene propylene diene monomer (EPDM) based polymers have been formulated for specific use in photovoltaic modules to produce better performance and longer term stability at a lower cost than standard materials. EPDM formulations are advantageous over ethylene vinyl-acetate (EVA) because they can use the same lamination/cure cycle as EVA, they do not need a second back-sheet protective material (e.g. PET/Tedlar), they have a lower glass transition temperature, no melting transition, more constant mechanical moduli as a function of temperature, they are less polar than EVA (provides better corrosion protection), and they have excellent damp heat (85 C/85% relative humidity) resistance against delamination. Module designs typically use EVA on the back side of cells despite the fact that transparency is not advantageous. We have developed a single encapsulant layer that will replace standard module back-sheet constructions consisting of EVA/PET/Tedlar. Because a single low-cost material layer is used, it will provide a significant materials cost savings of about $6 to $8/m{sup 2} as compared to traditional back-sheets. Electrical insulation tests were conducted using 0.85 mm thick stainless steel sheets as a model for a cell. It was found that a polymer layer thickness of about 0.33mm provided better high voltage electrical insulation than a combined film of Tedla (0.038 mm)/PET (0.051 mm)/EVA (0.55 mm). When formulated with a white pigment, reflectivity was comparable to Tedlar{trademark}. Upon accelerated exposure to light at 60C and 60% RH it was found that an EVA layer in front of these materials would decompose before significant yellowing and delamination of the back EPDM layer occurs.

  9. 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

  10. 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

  11. 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

  12. 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

  13. Centrifugal instability of Stokes layers in crossflow: the case of a forced cylinder wake

    E-Print Network [OSTI]

    Juan D'Adamo; Ramiro Godoy-Diana; José Eduardo Wesfreid

    2015-04-23T23:59:59.000Z

    The wake flow around a circular cylinder at $Re\\approx100$ performing rotatory oscillations has been thoroughly discussed in the literature, mostly focusing on the modifications to the natural B\\'enard-von K\\'arm\\'an vortex street that result from the forced shedding modes locked to the rotatory oscillation frequency. The usual experimental and theoretical frameworks at these Reynolds numbers are quasi-two-dimensional, since the secondary instabilities bringing a three-dimensional structure to the cylinder wake flow occur only at higher Reynolds numbers. In the present paper we show that a three-dimensional structure can appear below the usual three-dimensionalization threshold, when forcing with frequencies lower than the natural vortex shedding frequency, at high amplitudes, as a result of a previously unreported mechanism: a pulsed centrifugal instability of the oscillating Stokes layer at the wall of the cylinder. The present numerical investigation lets us in this way propose a physical explanation for the turbulence-like features reported in the recent experimental study of D'Adamo et al. (2011).

  14. Stabilization of liquid crystal photoaligning layers by reactive mesogens O. Yaroshchuk,1

    E-Print Network [OSTI]

    Stabilization of liquid crystal photoaligning layers by reactive mesogens O. Yaroshchuk,1 V photoaligning layers by thin layers of reactive mesogens, strong enhancement in LC alignment stability layer, the photoalignment technique minimizes me- chanical damage and electric charging, provides

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Hand portable thin-layer chromatography system

    DOE Patents [OSTI]

    Haas, Jeffrey S. (San Ramon, CA); Kelly, Fredrick R. (Modesto, CA); Bushman, John F. (Oakley, CA); Wiefel, Michael H. (La Honda, CA); Jensen, Wayne A. (Livermore, CA)

    2000-01-01T23:59:59.000Z

    A hand portable, field-deployable thin-layer chromatography (TLC) unit and a hand portable, battery-operated unit for development, illumination, and data acquisition of the TLC plates contain many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit includes a solvent tank, a holder for TLC plates, and a variety of tool chambers for storing TLC plates, solvent, and pipettes. After processing in the TLC unit, a TLC plate is positioned in a collapsible illumination box, where the box and a CCD camera are optically aligned for optimal pixel resolution of the CCD images of the TLC plate. The TLC system includes an improved development chamber for chemical development of TLC plates that prevents solvent overflow.

  8. Cleaning graphene with a titanium sacrificial layer

    SciTech Connect (OSTI)

    Joiner, C. A., E-mail: cjoiner3@gatech.edu; Roy, T.; Hesabi, Z. R.; Vogel, E. M. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Chakrabarti, B. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2014-06-02T23:59:59.000Z

    Graphene is a promising material for future electronic applications and chemical vapor deposition of graphene on copper is a promising method for synthesizing graphene on the wafer scale. The processing of such graphene films into electronic devices introduces a variety of contaminants which can be difficult to remove. An approach to cleaning residues from the graphene channel is presented in which a thin layer of titanium is deposited via thermal e-beam evaporation and immediately removed. This procedure does not damage the graphene as evidenced by Raman spectroscopy, greatly enhances the electrical performance of the fabricated graphene field effect transistors, and completely removes the chemical residues from the surface of the graphene channel as evidenced by x-ray photoelectron spectroscopy.

  9. Carbides composite surface layers produced by (PTA)

    SciTech Connect (OSTI)

    Tajoure, Meloud, E-mail: Tajoore2000@yahoo.com [MechanicalEng.,HIHM,Gharian (Libya); Tajouri, Ali, E-mail: Tajouri-am@yahoo.com, E-mail: dr.mokhtarphd@yahoo.com; Abuzriba, Mokhtar, E-mail: Tajouri-am@yahoo.com, E-mail: dr.mokhtarphd@yahoo.com [Materials and Metallurgical Eng., UOT, Tripoli (Libya); Akreem, Mosbah, E-mail: makreem@yahoo.com [Industrial Research Centre,Tripoli (Libya)

    2013-12-16T23:59:59.000Z

    The plasma transferred arc technique was applied to deposit a composite layer of nickel base with tungsten carbide in powder form on to surface of low alloy steel 18G2A type according to polish standard. Results showed that, plasma transferred arc hard facing process was successfully conducted by using Deloro alloy 22 plus tungsten carbide powders. Maximum hardness of 1489 HV and minimum dilution of 8.4 % were achieved by using an arc current of 60 A. However, when the current was further increased to 120 A and the dilution increases with current increase while the hardness decreases. Microstructure of the nickel base deposit with tungsten carbide features uniform distribution of reinforcement particles with regular grain shape half - dissolved in the matrix.

  10. Layered electrodes for lithium cells and batteries

    DOE Patents [OSTI]

    Johnson; Christopher S. (Naperville, IL), Thackeray; Michael M. (Naperville, IL), Vaughey; John T. (Elmhurst, IL), Kahaian; Arthur J. (Chicago, IL), Kim; Jeom-Soo (Naperville, IL)

    2008-04-15T23:59:59.000Z

    Lithium metal oxide compounds of nominal formula Li.sub.2MO.sub.2, in which M represents two or more positively charged metal ions, selected predominantly and preferably from the first row of transition metals are disclosed herein. The Li.sub.2MO.sub.2 compounds have a layered-type structure, which can be used as positive electrodes for lithium electrochemical cells, or as a precursor for the in-situ electrochemical fabrication of LiMO.sub.2 electrodes. The Li.sub.2MO.sub.2 compounds of the invention may have additional functions in lithium cells, for example, as end-of-discharge indicators, or as negative electrodes for lithium cells.

  11. Forty kilojoule carbon double layer capacitor

    SciTech Connect (OSTI)

    Evans, D.A. [Evans Co., East Providence, RI (United States)

    1994-10-01T23:59:59.000Z

    Evans was awarded a Small Business Innovation Research (SBIR) grant from the Department of the Navy to determine if carbon double layer capacitor (DLC) technology could be used as a bridge DC power source for submarine computer systems. The Navy is interested in the technology because DLCs have high power density, require no maintenance, and are free of the hazards commonly associated with batteries. The proposed work had three main objectives: First, to design a DLC power source capable of a 15 kw average discharge rate for a minimum of 100 ms. The operating voltage was to be selected by external buss connections at 15 to 120 volts. And, the unit needed to be sealed to prevent contamination and electrolyte loss. Second, to fabricate the device according to this design and third, to measure the electrical characteristics, evaluate power performance, and report the results to the Navy. This article describes the design and performance of the capacitor.

  12. Fabrication of Ceramic Layer-by-Layer Infrared Wavelength Photonic Band Gap Crystals

    SciTech Connect (OSTI)

    Henry Hao-Chuan Kang

    2004-12-19T23:59:59.000Z

    Photonic band gap (PBG) crystals, also known as photonic crystals, are periodic dielectric structures which form a photonic band gap that prohibit the propagation of electromagnetic (EM) waves of certain frequencies at any incident angles. Photonic crystals have several potential applications including zero-threshold semiconductor lasers, the inhibition of spontaneous emission, dielectric mirrors, and wavelength filters. If defect states are introduced in the crystals, light can be guided from one location to another or even a sharp bending of light in micron scale can be achieved. This generates the potential for optical waveguide and optical circuits, which will contribute to the improvement in the fiber-optic communications and the development of high-speed computers.

  13. Method of fabricating a solar cell with a tunnel dielectric layer

    DOE Patents [OSTI]

    Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David; Waldhauer, Ann

    2012-12-18T23:59:59.000Z

    Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

  14. Method of fabricating a solar cell with a tunnel dielectric layer

    DOE Patents [OSTI]

    Dennis, Tim; Harrington, Scott; Manning, Jane; Smith, David D; Waldhauer, Ann

    2014-04-29T23:59:59.000Z

    Methods of fabricating solar cells with tunnel dielectric layers are described. Solar cells with tunnel dielectric layers are also described.

  15. Photovoltaic Cell Having A P-Type Polycrystalline Layer With Large Crystals

    DOE Patents [OSTI]

    Albright, Scot P. (Lakewood, CO); Chamberlin, Rhodes R. (El Paso, TX)

    1996-03-26T23:59:59.000Z

    A photovoltaic cell has an n-type polycrystalline layer and a p-type polycrystalline layer adjoining the n-type polycrystalline layer to form a photovoltaic junction. The p-type polycrystalline layer comprises a substantially planar layer portion having relatively large crystals adjoining the n-type polycrystalline layer. The planar layer portion includes oxidized impurities which contribute to obtainment of p-type electrical properties in the planar layer portion.

  16. Evaluate Si Layers: Cooperative Research and Development Final Report, CRADA Number CRD-07-255

    SciTech Connect (OSTI)

    Teplin, C.

    2013-04-01T23:59:59.000Z

    Evaluate Si layers based on heteroepitaxial Si growth on RABITS textured metal substrates coated with textured buffer layers.

  17. Power Control in Multi-Layer Cellular Networks

    E-Print Network [OSTI]

    Davaslioglu, Kemal

    2012-01-01T23:59:59.000Z

    We investigate the possible performance gains of power control in multi-layer cellular systems where microcells and picocells are distributed within macrocells. Although multilayers in cellular networks help increase system capacity and coverage, and can reduce total energy consumption; they cause interference, reducing the performance of the network. Therefore, downlink transmit power levels of multi-layer hierarchical cellular networks need to be controlled in order to fully exploit their benefits. In this work, we present an analytical derivation to determine optimum power levels for two-layer cellular networks and generalize our solution to multi-layer cellular networks. We also simulate our results in a typical multi-layer network setup and observe significant power savings compared to single-layer cellular networks.

  18. Effect of temperature on layer separation by plasma hydrogenation

    SciTech Connect (OSTI)

    Di, Z. F.; Wang, Y. Q.; Nastasi, M. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rossi, F. [Joint Research Centre, European Commission, 21020 Ispra (Italy); Shao, L. [Department of Nuclear Engineering, Texas A and M University, 3133 TAMU, College Station, Texas 77843 (United States); Thompson, P. E. [Code 6812, Naval Research Laboratory, Washington, D.C. 20375-5347 (United States)

    2008-12-22T23:59:59.000Z

    We have studied hydrogen diffusion in plasma hydrogenated Si/SiGe/Si heterostructure at different temperatures. At low temperature, intrinsic point defects in the molecular beam epitaxy grown Si capping layer are found to compete with the buried strain SiGe layer for hydrogen trapping. The interaction of hydrogen with point defects affects the hydrogen long-range diffusion, and restricts the amount of hydrogen available for trapping by the SiGe layer. However, hydrogen trapping by the capping layer is attenuated with increasing hydrogenation temperature allowing more hydrogen to be trapped in the strain SiGe layer with subsequent surface blister formation. A potential temperature window for plasma hydrogenation induced layer separation is identified based on the combined considerations of trap-limited diffusion at low temperature and outdiffusion of H{sub 2} molecule together with the dissociation of Si-H bonds inside of H platelet at high temperature.

  19. Effect of temperature on layer separation by plasma-hydrogenation

    SciTech Connect (OSTI)

    Di, Zengfeng [Los Alamos National Laboratory; Michael, Nastasi A [Los Alamos National Laboratory; Wang, Yongqiang [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    We have studied hydrogen diffusion in plasma hydrogenated Si/SiGe/Si heterostructure at different temperatures. At low temperature, intrinsic point defects in the molecular beam epitaxy grown Si capping layer are found to compete with the buried strain SiGe layer for hydrogen trapping. The interaction of hydrogen with point defects affects the hydrogen long-range diffusion, and restricts the amount of hydrogen available for trapping by the SiGe layer. However, hydrogen trapping by the capping layer is attenuated with increasing hydrogenation temperature allowing more hydrogen to be trapped in the strain SiGe layer with subsequent surface blister formation. A potential temperature window for plasma hydrogenation induced layer separation is identified based on the combined considerations of trap-limited diffusion at low temperature and outdiffusion of H{sub 2} molecule together with the dissociation of Si-H bonds inside of H platelet at high temperature.

  20. Pressure-assisted fabrication of organic light emitting diodes with MoO{sub 3} hole-injection layer materials

    SciTech Connect (OSTI)

    Du, J. [The Princeton Institute for the Science and Technology of Materials (PRISM), Princeton, New Jersey 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Anye, V. C.; Vodah, E. O. [Department of Materials Science and Engineering, African University of Science and Technology, Abuja, Federal Capital Territory (Nigeria); Tong, T. [The Princeton Institute for the Science and Technology of Materials (PRISM), Princeton, New Jersey 08544 (United States); Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Zebaze Kana, M. G. [Physics Advanced Laboratory, Sheda Science and Technology Complex, Abuja, Federal Capital Territory (Nigeria); Department of Materials Science and Engineering, Kwara State University, Kwara State (Nigeria); Soboyejo, W. O. [The Princeton Institute for the Science and Technology of Materials (PRISM), Princeton, New Jersey 08544 (United States); Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Department of Materials Science and Engineering, African University of Science and Technology, Abuja, Federal Capital Territory (Nigeria)

    2014-06-21T23:59:59.000Z

    In this study, pressures of ?5 to ?8?MPa were applied to organic light emitting diodes containing either evaporated molybdenum trioxide (MoO{sub 3}) or spin-coated poly(3,4-ethylene dioxythiophene) doped with poly(styrene sulphonate) (PEDOT:PSS) hole-injection layers (HILs). The threshold voltages for both devices were reduced by about half, after the application of pressure. Furthermore, in an effort to understand the effects of pressure treatment, finite element simulations were used to study the evolution of surface contact between the HIL and emissive layer (EML) under pressure. The blister area due to interfacial impurities was also calculated. This was shown to reduce by about half, when the applied pressures were between ?5 and 8?MPa. The finite element simulations used Young's modulus measurements of MoO{sub 3} that were measured using the nanoindentation technique. They also incorporated measurements of the adhesion energy between the HIL and EML (measured by force microscopy during atomic force microscopy). Within a fracture mechanics framework, the implications of the results are then discussed for the pressure-assisted fabrication of robust organic electronic devices.