WorldWideScience

Sample records for single weak streamwise

  1. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H

    2015-09-23

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  2. Hybrid Manipulation of Streamwise Vorticity in a Diffuser Boundary Layer

    Science.gov (United States)

    Gissen, Abraham; Vukasinovic, Bojan; Culp, John; Glezer, Ari

    2010-11-01

    The formation of streamwise vorticity concentrations by exploiting the interaction of surface-mounted passive (micro-vanes) and active (synthetic jets) flow control elements with the cross flow is investigated experimentally in a small-scale serpentine duct at high subsonic speeds (up to M = 0.6). Streamwise vortices can be a key element in the mitigation of the adverse effects on pressure recovery and distortion caused by the naturally occurring secondary flows in embedded propulsion systems with complex inlet geometries. Counter rotating and single-sense vortices are formed using conventional passive micro-vanes and active high-power synthetic jet actuators. Interaction of the flow control elements is examined through a hybrid actuation scheme whereby synthetic jet actuation augments the primary vanes' vortices resulting in dynamic enhancement of their strength. It is shown that such sub-boundary layer individual vortices can merge and evolve into duct-scale vortical structures that counteract the inherent secondary flow and mitigates global flow distortion.

  3. Electrically tunable single-dot nanocavities in the weak and strong coupling regimes

    DEFF Research Database (Denmark)

    Laucht, Arne; Hofbauer, Felix; Angele, Jacob

    2008-01-01

    We report the design, fabrication and optical investigation of electrically tunable single quantum dot - photonic crystal defect nanocavities [1] operating in both the weak and strong coupling regimes of the light matter interaction. Unlike previous studies, where the dot-cavity spectral detuning...... of the emitted photons from a single-dot nanocavity in the weak and strong coupling regimes. New information is obtained on the nature of the dot-cavity coupling in the weak coupling regime and electrical control of zero dimensional polaritons is demonstrated for the first time. Vacuum Rabi splittings up to 2g...... electrical readout of the strongly coupled dot-cavity system using photocurrent methods will be discussed. This work is financially supported by the DFG via SFB 631 and by the German Excellence Initiative via the “Nanosystems Initiative Munich (NIM)”....

  4. Vortex phase diagram studies in the weakly pinned single crystals of ...

    Indian Academy of Sciences (India)

    Vortex phase diagram studies in the weakly pinned single crystals of YNi2B2C and LuNi2B2C. D JAISWAL-NAGAR1,∗, D PAL2, M R ESKILDSEN2, P C CANFIELD3,. H TAKEYA4, S RAMAKRISHNAN1 and A K GROVER1,†. 1Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental ...

  5. Macromolecular X-ray structure determination using weak, single-wavelength anomalous data

    Energy Technology Data Exchange (ETDEWEB)

    Bunkóczi, Gábor; McCoy, Airlie J.; Echols, Nathaniel; Grosse-Kunstleve, Ralf W.; Adams, Paul D.; Holton, James M.; Read, Randy J.; Terwilliger, Thomas C.

    2014-12-22

    We describe a likelihood-based method for determining the substructure of anomalously scattering atoms in macromolecular crystals that allows successful structure determination by single-wavelength anomalous diffraction (SAD) X-ray analysis with weak anomalous signal. With the use of partial models and electron density maps in searches for anomalously scattering atoms, testing of alternative values of parameters and parallelized automated model-building, this method has the potential to extend the applicability of the SAD method in challenging cases.

  6. On Spectral Invariance of Single Scattering Albedo for Weakly Absorbing Wavelengths

    Science.gov (United States)

    Marshak, Alexander

    2012-01-01

    The single scattering albedo omega (sub 0 lambda) in atmospheric radiative transfer is the ratio of the scattering coefficient to the total extinction coefficient. For cloud water droplets both the scattering and absorption coefficients, thus the single scattering albedo, are functions of wavelength A and droplet size r. In this presentation we will show that for water droplets at weakly absorbing wavelengths, the ratio omega (sub 0 lambda)(r). The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo omega (sub 0 lambda) via one known spectrum omega (sub 0 lambda)(r(sub o)). We will provide a simple physical explanation of the discovered relationship. In addition to water droplets, similar linear relationships were found for the single scattering albedo of non-spherical ice crystals. The single scattering albedo $\\omega _ {0\\lambda }$ in atmospheric radiative transfer is the ratio of the scattering coefficient to the total extinction coefficient. For cloud water droplets both the scattering and absorption coefficients, and thus the single scattering albedo, are functions of wavelength $\\lambda $ and droplet size $r$. We show that for water droplets at weakly absorbing wavelengths, the ratio $\\omega _ {0\\lambda } (r)$/$\\omega _ {0\\lambda } (r_{0})$ of two single scattering albedo spectra for two different droplet sizes is a linear function of $\\omega _{0\\lambda }(r)$. The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo $\\omega_{0\\lambda }(r)$ via one known spectrum $\\omega_{0\\lambda }(r_{0})$. We provide a simple physical explanation of the discovered relationship. Similar linear relationships characterize the single scattering albedo of non-spherical ice crystals.

  7. Weak superconducting pairing and a single isotropic energy gap in stoichiometric LiFeAs.

    Science.gov (United States)

    Inosov, D S; White, J S; Evtushinsky, D V; Morozov, I V; Cameron, A; Stockert, U; Zabolotnyy, V B; Kim, T K; Kordyuk, A A; Borisenko, S V; Forgan, E M; Klingeler, R; Park, J T; Wurmehl, S; Vasiliev, A N; Behr, G; Dewhurst, C D; Hinkov, V

    2010-05-07

    We report superconducting (SC) properties of stoichiometric LiFeAs (T(c)=17 K) studied by small-angle neutron scattering (SANS) and angle-resolved photoemission (ARPES). Although the vortex lattice exhibits no long-range order, well-defined SANS rocking curves indicate better ordering than in chemically doped 122 compounds. The London penetration depth lambda(ab)(0)=210+/-20 nm, determined from the magnetic field dependence of the form factor, is compared to that calculated from the ARPES band structure with no adjustable parameters. The temperature dependence of lambda(ab) is best described by a single isotropic SC gap Delta(0)=3.0+/-0.2 meV, which agrees with the ARPES value of Delta(0)(ARPES)=3.1+/-0.3 meV and corresponds to the ratio 2Delta/k(B)T(c)=4.1+/-0.3, approaching the weak-coupling limit predicted by the BCS theory. This classifies LiFeAs as a weakly coupled single-gap superconductor.

  8. Single-chain-in-mean-field simulations of weak polyelectrolyte brushes

    Science.gov (United States)

    Léonforte, F.; Welling, U.; Müller, M.

    2016-12-01

    Structural properties of brushes which are composed of weak acidic and basic polyelectrolytes are studied in the framework of a particle-based approach that implicitly accounts for the solvent quality. Using a semi-grandcanonical partition function in the framework of the Single-Chain-in-Mean-Field (SCMF) algorithm, the weak polyelectrolyte is conceived as a supramolecular mixture of polymers in different dissociation states, which are explicitly treated in the partition function and sampled by the SCMF procedure. One obtains a local expression for the equilibrium acid-base reaction responsible for the regulation of the charged groups that is also incorporated to the SCMF sampling. Coupled to a simultaneous treatment of the electrostatics, the approach is shown to capture the main features of weak polyelectrolyte brushes as a function of the bulk pH in the solution, the salt concentration, and the grafting density. Results are compared to experimental and theoretical works from the literature using coarse-grained representations of poly(acrylic acid) (PAA) and poly(2-vinyl pyridine) (P2VP) polymer-based brushes. As the Born self-energy of ions can be straightforwardly included in the numerical approach, we also study its effect on the local charge regulation mechanism of the brush. We find that its effect becomes significant when the brush is dense and exposed to high salt concentrations. The numerical methodology is then applied (1) to the study of the kinetics of collapse/swelling of a P2VP brush and (2) to the ability of an applied voltage to induce collapse/swelling of a PAA brush in a pH range close to the pKa value of the polymer.

  9. Probabilistically cloning two single-photon states using weak cross-Kerr nonlinearities

    International Nuclear Information System (INIS)

    Zhang, Wen; Rui, Pinshu; Zhang, Ziyun; Yang, Qun

    2014-01-01

    By using quantum nondemolition detectors (QNDs) based on weak cross-Kerr nonlinearities, we propose an experimental scheme for achieving 1→2 probabilistic quantum cloning (PQC) of a single-photon state, secretly choosing from a two-state set. In our scheme, after a QND is performed on the to-be-cloned photon and the assistant photon, a single-photon projection measurement is performed by a polarization beam splitter (PBS) and two single-photon trigger detectors (SPTDs). The measurement is to judge whether the PQC should be continued. If the cloning fails, a cutoff is carried out and some operations are omitted. This makes our scheme economical. If the PQC is continued according to the measurement result, two more QNDs and some unitary operations are performed on the to-be-cloned photon and the cloning photon to achieve the PQC in a nearly deterministic way. Our experimental scheme for PQC is feasible for future technology. Furthermore, the quantum logic network of our PQC scheme is presented. In comparison with similar networks, our PQC network is simpler and more economical. (paper)

  10. Effects of streamwise vortex breakdown on supersonic combustion.

    Science.gov (United States)

    Hiejima, Toshihiko

    2016-04-01

    This paper presents a numerical simulation study of the combustion structure of streamwise vortex breakdown at Mach number 2.48. Hydrogen fuel is injected into a combustor at sonic speed from the rear of a hypermixer strut that can generate streamwise vortices. The results show that the burning behavior is enhanced at the points of the shock waves that are incident on the vortex and therefore the vortex breakdown in the subsonic region occurs due to combustion. The breakdown domain in the mainstream is found to form a flame-holding region suited to combustion and to lead to a stable combustion field with detached flames. In this way, streamwise vortex breakdown has an essential role in combustion enhancement and the formation of flames that hold under supersonic inflow conditions. Finally, the combustion property defined here is shown to coincide with the produced-water mass flow. This property shows that the amount of combustion is saturated at equivalence ratios over 0.4, although there is a slight increase beyond 1.

  11. Comparative Effects of Four Single Leg Squat Exercises in Subjects with Gluteus Medius Weakness.

    Science.gov (United States)

    Han, Hae-Rim; Yi, Chung-Hwi; You, Sung-Hyun; Cynn, Heon-Seock; Lim, One-Bin; Son, Jae-Ik

    2017-07-17

    Of the weight bearing exercises, single leg squat (SLS) represents one of the most commonly used hip strengthening exercises that require more gluteus medius (GMED) activity. To date, no studies have investigated how the four SLS exercises affects muscle imbalance of GMED, tensor fasciae latae (TFL), and adductor longus (AL), and kinematics of hip. To investigate the hip muscle activities, onset time, and kinematics during four different SLS exercises (unilateral squat, unilateral wall-squat, lateral step-down, and front step-down) in subjects with GMED weakness. Repeated-measures experimental design. Research laboratory. Twenty-two subjects (11 males and 11 females) participated in this study and were compared using one-way repeated analysis of variance. Surface electromyography was used to measure the muscle activities and onset time of the GMED, TFL, and AL, and 3-dimensional motion tracking system was used to measure the hip adduction and internal/external rotation angles during SLS exercises. One-way repeated analysis of variance was used at a significance level of p<0.05. The unilateral wall-squat produced higher GMED/TFL activity ratio and lower GMED/TFL onset time ratio than in the other three exercises (p<0.05). No difference in GMED/AL activity ratio and GMED/AL onset time ratio was observed. The hip adduction angle was greater in unilateral wall-squat than in the other three exercises (p<0.05). As for the hip internal/external rotation, lateral step-down exhibited higher hip internal rotation angle than front step-down (p<0.05). The unilateral wall-squat may be recommended as an effective exercise for the subjects with GMED weakness, but they should take care to avoid excessive hip adduction during the exercise.

  12. Weak antilocalization in Bi2-x Inx Te3 single crystals

    Science.gov (United States)

    Chi, Hang; Li, Qiang; Uher, Ctirad

    Bi2Te3 has recently been identified as one of the most promising systems with which to realize a three-dimensional topological insulator. However, the bulk, stoichiometric Bi2Te3 single crystals often exhibit p-type metallic electrical conduction due to the BiTe-type antisite defects, which overshadows the contribution of surface states. We have established that, upon group III (indium and/or thallium) doping, the Fermi level of Bi2Te3 can be lifted from the valence band into the band gap, and eventually shifted into the conduction band. Such doping progressively changes the electrical conduction of Bi2-xAxTe3 (A = In, Tl, and x = 0 - 0.30) single crystals from p-type to n-type. This is observed via measurements of both the Hall effect and the Seebeck coefficient performed in the (0001) basal plane in the temperature range of 2 - 300 K. At low levels, the temperature dependent in-plane electrical resistivity maintains its metallic character as the density of holes decreases. Heavier doping content, x = 0.20 (0.10) for In (Tl), drives the electrical resistivity into a prominent non-metallic regime displaying the weak anti-localization type of magnetoresistance at the lowest temperatures for Bi1.80In0.20Te3. At the highest concentration, the samples revert back into the metallic state with electron dominated conduction. Thermal conductivity measurements of Bi2-xAxTe3 single crystals, as examined by the Debye-Callaway phonon conductivity model, reveal a generally stronger point defect scattering of phonons upon doping.

  13. Analysis of trace inorganic anions in weak acid salts by single pump cycling-column-switching ion chromatography.

    Science.gov (United States)

    Huang, Zhongping; Ni, Chengzhu; Zhu, Zhuyi; Pan, Zaifa; Wang, Lili; Zhu, Yan

    2015-05-01

    The application of ion chromatography with the single pump cycling-column-switching technique was described for the analysis of trace inorganic anions in weak acid salts within a single run. Due to the hydrogen ions provided by an anion suppressor electrolyzing water, weak acid anions could be transformed into weak acids, existing as molecules, after passing through the suppressor. Therefore, an anion suppressor and ion-exclusion column were adopted to achieve on-line matrix elimination of weak acid anions with high concentration for the analysis of trace inorganic anions in weak acid salts. A series of standard solutions consisting of target anions of various concentrations from 0.005 to 10 mg/L were analyzed, with correlation coefficients r ≥ 0.9990. The limits of detection were in the range of 0.67 to 1.51 μg/L, based on the signal-to-noise ratio of 3 and a 25 μL injection volume. Relative standard deviations for retention time, peak area, and peak height were all less than 2.01%. A spiking study was performed with satisfactory recoveries between 90.3 and 104.4% for all anions. The chromatographic system was successfully applied to the analysis of trace inorganic anions in five weak acid salts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Determination of trace inorganic anions in weak acids by single-pump column-switching ion chromatography.

    Science.gov (United States)

    Zhu, Haibao; Chen, Huadong; Zhong, Yingying; Ren, Dandan; Qian, Yaling; Tang, Hongfang; Zhu, Yan

    2010-08-01

    Ion chromatography has been proposed for the determination of three common inorganic anions (chloride, nitrate, and sulfate) in nine weak acids (tartaric acid, citric acid, formic acid, acetic acid, metacetonic acid, butyric acid, butanedioic acid, hexafluorophosphoric acid, and salicylic acid) using a single pump, two valves, a single eluent, and a single conductivity detector. The present system uses ion exclusion, concentrator, and anion-exchange columns connected in series via 6-port and 10-port valves in a Dionex ICS-2100 ion chromatograph. The valves were switched for the determination of three inorganic anions from weak acids in a single chromatographic run. Sample matrices of weak acids with a series of concentrations can be investigated. Complete separations of the previously mentioned anions are demonstrated within 40 min. Under the optimum conditions, the relative standard deviation values ranged from 1.3 to 3.8%. The detection limits of the three inorganic anions (S/N = 3) were in the range of 0.3-1.7 microg/L. The recoveries were in the range of 75.2-117.6%. With this system, automation for routine analysis, short analysis time, and low cost can be achieved.

  15. Streamwise decay of localized states in channel flow

    Science.gov (United States)

    Zammert, Stefan; Eckhardt, Bruno

    2016-10-01

    Channel flow, the pressure driven flow between parallel plates, has exact coherent structures that show various degrees of localization. For states which are localized in streamwise direction but extended in spanwise direction, we show that they are exponentially localized, with decay constants that are different on the upstream and downstream sides. We extend the analysis of Brand and Gibson [J. Fluid Mech. 750, R1 (2014)], 10.1017/jfm.2014.285 for stationary states to the case of advected structures that is needed here, and derive expressions for the decay in terms of eigenvalues and eigenfunctions of certain second order differential equations. The results are in very good agreement with observations on exact coherent structures of different transversal wavelengths.

  16. Light from Within: Sensing Weak Strains and FemtoNewton Forces in Single Molecules

    NARCIS (Netherlands)

    Laar, van de Ties; Schuurman, Hent; Scheer, van der Pieter; Maarten van Doorn, Jan; Gucht, van der Jasper; Sprakel, Joris

    2018-01-01

    Weak mechanical forces acting on molecules are in control of a wide variety of (bio)chemical and physical processes. The spatially inhomogeneous nature of these forces has a profound effect on the structure and mechanics of soft and biological materials. Yet, the lack of methods for probing

  17. Numerical correction of anti-symmetric aberrations in single HRTEM images of weakly scattering 2D-objects

    International Nuclear Information System (INIS)

    Lehtinen, Ossi; Geiger, Dorin; Lee, Zhongbo; Whitwick, Michael Brian; Chen, Ming-Wei; Kis, Andras; Kaiser, Ute

    2015-01-01

    Here, we present a numerical post-processing method for removing the effect of anti-symmetric residual aberrations in high-resolution transmission electron microscopy (HRTEM) images of weakly scattering 2D-objects. The method is based on applying the same aberrations with the opposite phase to the Fourier transform of the recorded image intensity and subsequently inverting the Fourier transform. We present the theoretical justification of the method, and its verification based on simulated images in the case of low-order anti-symmetric aberrations. Ultimately the method is applied to experimental hardware aberration-corrected HRTEM images of single-layer graphene and MoSe 2 resulting in images with strongly reduced residual low-order aberrations, and consequently improved interpretability. Alternatively, this method can be used to estimate by trial and error the residual anti-symmetric aberrations in HRTEM images of weakly scattering objects

  18. Heat-Transfer Enhancement by Artificially Generated Streamwise Vorticity

    Science.gov (United States)

    Ghanem, Akram; Habchi, Charbel; Lemenand, Thierry; Della Valle, Dominique; Peerhossaini, Hassan

    2012-11-01

    Vortex-induced heat transfer enhancement exploits longitudinal and transverse pressure-driven vortices through the deliberate artificial generation of large-scale vortical flow structures. Thermal-hydraulic performance, Nusselt number and friction factor are experimentally investigated in a HEV (high-efficiency vortex) mixer, which is a tubular heat exchanger and static mixer equipped with trapezoidal vortex generators. Pressure gradients are generated on the trapezoidal tab initiating a streamwise swirling motion in the form of two longitudinal counter-rotating vortex pairs (CVP). Due to the Kelvin-Helmholtz instability, the shear layer generated at the tab edges, which is a production site of turbulence kinetic energy (TKE), becomes unstable further downstream from the tabs and gives rise to periodic hairpin vortices. The aim of the study is to quantify the effects of hydrodynamics on the heat- and masstransfer phenomena accompanying such flows for comparison with the results of numerical studies and validate the high efficiency of the intensification process implementing such vortex generators. The experimental results reflect the enhancement expected from the numerical studies and confirm the high status of the HEV heat exchanger and static mixer.

  19. On Spectral Invariance of Single Scattering Albedo for Water Droplets and Ice Crystals at Weakly Absorbing Wavelengths

    Science.gov (United States)

    Marshak, Alexander; Knyazikhin, Yuri; Chiu, J. Christine; Wiscombe, Warren J.

    2012-01-01

    The single scattering albedo omega(sub O lambda) in atmospheric radiative transfer is the ratio of the scattering coefficient to the extinction coefficient. For cloud water droplets both the scattering and absorption coefficients, thus the single scattering albedo, are functions of wavelength lambda and droplet size r. This note shows that for water droplets at weakly absorbing wavelengths, the ratio omega(sub O lambda)(r)/omega(sub O lambda)(r (sub O)) of two single scattering albedo spectra is a linear function of omega(sub O lambda)(r). The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo spectrum omega(sub O lambda)(r) via one known spectrum omega(sub O lambda)(r (sub O)). We provide a simple physical explanation of the discovered relationship. Similar linear relationships were found for the single scattering albedo spectra of non-spherical ice crystals.

  20. Weakly coupled map lattice models for multicellular patterning and collective normalization of abnormal single-cell states

    Science.gov (United States)

    García-Morales, Vladimir; Manzanares, José A.; Mafe, Salvador

    2017-04-01

    We present a weakly coupled map lattice model for patterning that explores the effects exerted by weakening the local dynamic rules on model biological and artificial networks composed of two-state building blocks (cells). To this end, we use two cellular automata models based on (i) a smooth majority rule (model I) and (ii) a set of rules similar to those of Conway's Game of Life (model II). The normal and abnormal cell states evolve according to local rules that are modulated by a parameter κ . This parameter quantifies the effective weakening of the prescribed rules due to the limited coupling of each cell to its neighborhood and can be experimentally controlled by appropriate external agents. The emergent spatiotemporal maps of single-cell states should be of significance for positional information processes as well as for intercellular communication in tumorigenesis, where the collective normalization of abnormal single-cell states by a predominantly normal neighborhood may be crucial.

  1. Adjusting output impedance using a PI controller to improve the stability of a single-phase inverter under weak grid

    Directory of Open Access Journals (Sweden)

    Jiao Jiao

    2016-11-01

    Full Text Available Explored in this paper is the grid impedance effect on the stability of a single-phase grid connected inverter with an LC filter based on an analysis of the inverter output impedance. For a single-phase grid connected inverter, a PI controller is often used to regulate the current injected into the grid. However, the control performance can be influenced when the inverter is connected to a weak grid. Also, the utility grid has background harmonic noise, which can make the injected current distorted. Therefore, analysis of the output impedance of a single-phase grid connected inverter is important for the robustness and stability of the system. By modeling the output impedance of inverter, it can be determined that the proportional gain and integral gain of the controller have an effect on the output impedance. Analytical results show that by adjusting the PI controller parameters, the ability for harmonic reduction and stability of the system can be improved. Simulation and experiments using a 1 kW single-phase grid connected inverter verify the effectiveness of the theoretical analysis.

  2. Spatial averaging of streamwise and spanwise velocity measurements in wall-bounded turbulence using ∨- and ×-probes

    International Nuclear Information System (INIS)

    Philip, Jimmy; Baidya, Rio; Hutchins, Nicholas; Monty, Jason P; Marusic, Ivan

    2013-01-01

    The effect of finite dimensions of ∨- and ×-probes is investigated for the measurement of mean and variances of streamwise and spanwise velocities in wall-turbulence. The probes are numerically simulated using a Direct Numerical Simulation database of channel flow at a friction Reynolds number (Re τ ) of 934 by varying the probe parameters, namely, the wire-lengths (l), the angle between the wires (θ) and the spacing between the wires (Δs). A single inclined wire is first studied to isolate the effect of l and θ. Analytical expressions for the variances of the streamwise and spanwise velocities are derived by applying a linear-box-type filter to the unfiltered velocity field for both ∨- and ×-probes (at θ = 45°, and arbitrary l and Δs). A similar expression for the streamwise variance in the case of a single inclined wire (for arbitrary l and θ) is also derived. These analytical expressions, supplemented with a model for the correlation over the wire-length, compare favourably with the numerical simulation results, and more importantly explain various trends that are observed in the variances with varying parameters. Close to the wall (where the errors are generally higher) the errors in spanwise variances of the ×-probes are much lower than the ∨-probes, owing to an ‘error-cancelling’ mechanism present in ×-probes due to the effect of l and Δs, as well as due to the procedure of recovering the velocities from two wires. The errors in the streamwise variances are comparable for both ∨- and ×-probes. On the other hand, mean velocities are measured with almost no error by the ∨-probe, whereas the ×-probe induces finite errors in mean velocities due to the fact that the two wires experience different mean velocities in ×-probes unlike ∨-probes. These results are explained using the corresponding analytical results, which also show that under the effect of a linear filter, measured variances depend only on the fluctuating velocities

  3. Beam Normal Single Spin Asymmetry in Forward Angle Inelastic Electron-Proton Scattering using the Q-Weak Apparatus

    Energy Technology Data Exchange (ETDEWEB)

    ., Nuruzzaman [Hampton Univ., Hampton, VA (United States)

    2014-12-01

    The Q-weak experiment in Hall-C at the Thomas Jefferson National Accelerator Facility has made the first direct measurement of the weak charge of the proton through the precision measurement of the parity-violating asymmetry in elastic electron-proton scattering at low momentum transfer. There is also a parity conserving Beam Normal Single Spin Asymmetry or transverse asymmetry (B_n) on H_2 with a sin(phi)-like dependence due to two-photon exchange. If the size of elastic B_n is a few ppm, then a few percent residual transverse polarization in the beam, combined with small broken azimuthal symmetries in the detector, would require a few ppb correction to the Q-weak data. As part of a program of B_n background studies, we made the first measurement of B_n in the N-to-Delta(1232) transition using the Q-weak apparatus. The final transverse asymmetry, corrected for backgrounds and beam polarization, was found to be B_n = 42.82 ± 2.45 (stat) ± 16.07 (sys) ppm at beam energy E_beam = 1.155 GeV, scattering angle theta = 8.3 deg, and missing mass W = 1.2 GeV. B_n from electron-nucleon scattering is a unique tool to study the gamma^* Delta Delta form factors, and this measurement will help to improve the theoretical models on beam normal single spin asymmetry and thereby our understanding of the doubly virtual Compton scattering process. To help correct false asymmetries from beam noise, a beam modulation system was implemented to induce small position, angle, and energy changes at the target to characterize detector response to the beam jitter. Two air-core dipoles separated by ~10 m were pulsed at a time to produce position and angle changes at the target, for virtually any tune of the beamline. The beam energy was modulated using an SRF cavity. The hardware and associated control instrumentation will be described in this dissertation. Preliminary detector sensitivities were extracted which helped to reduce the width of the measured asymmetry. The beam modulation system

  4. DNS of turbulent heat transfer in a channel flow with streamwisely varying thermal boundary condition

    International Nuclear Information System (INIS)

    Seki, Yohji; Kawamura, Hiroshi

    2005-01-01

    Direct numerical simulation (DNS) have been performed for the turbulent heat transfer in a channel flow. In the present study, effect of thermal boundary condition is examined. DNS has been carried out for streamwisely thermal boundary conditions (Re τ =180) with Pγ=0.71 to obtain statistical mean temperatures, temperature variances, budget terms and time scale ratios etc. The obtained results have indicated that the time scale ratio varies along a streamwise. (author)

  5. First Measurement of the Beam Normal Single Spin Asymmetry in $Δ$ Resonance Production by $Q_{\\rm weak}$

    Energy Technology Data Exchange (ETDEWEB)

    Nuruzzaman, nfn [Hampton Univ., Hampton, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-08-01

    The beam normal single spin asymmetry ($B_{\\rm n}$) is generated in the scattering of transversely polarized electrons from unpolarized nuclei. The asymmetry arises from the interference of the imaginary part of the two-photon exchange with the one-photon exchange amplitude. The $Q_{\\rm weak}$ experiment has made the first measurement of $B_{\\rm n}$ in the production of the $\\Delta$(1232) resonance, using the $Q_{\\rm weak}$ apparatus in Hall-C at the Thomas Jefferson National Accelerator Facility. The final transverse asymmetry, corrected for backgrounds and beam polarization, is $B_{\\rm n}$ = 43 $\\pm$ 16 ppm at beam energy 1.16 GeV at an average scattering angle of about 8.3 degrees, and invariant mass of 1.2 GeV. The measured preliminary $B_{\\rm n}$ agrees with a preliminary theoretical calculation. $B_{\\rm n}$ for the $\\Delta$ is the only known observable that is sensitive to the $\\Delta$ elastic form-factors ($\\gamma$*$\\Delta\\Delta$) in addition to the generally studied transition form-factors ($\\gamma$*N$\\Delta$), but extracting this information will require significant theoretical input.

  6. Transport in Weakly Coupled Vertical Double Quantum Dots: Single-Particle Energy Level Spectroscopy and Hyperfine Interaction Effects

    Science.gov (United States)

    Payette, Christopher

    2011-12-01

    Performing transport measurements on weakly coupled vertical double quantum dots, we study by magneto-resonant-tunneling spectroscopy, single-particle energy spectra of the constituent dots over a wide energy window. The measured energy spectra are well modeled overall by ideal spectra calculated for elliptical and parabolic in-dot-plane confinement potentials. However, in regions where single-particle energy levels are naively expected to cross, we observe pronounced level anti-crossing behaviour and strong resonant current variations (both enhancement and suppression). Within a coherent tunneling picture, these effects can be attributed to coherent level mixing induced by weak perturbations in the nearly ideal dot confinement potentials. We analyze the energy spectra in detail, and focus on examples of two-, three- and four-level crossings where we observe the suppression of an otherwise strong current resonance, a signature of dark state formation due to destructive interference. The mixing we measure and model at two three-level crossings represents an all-electrical analogue of coherent population trapping. We also explore the limitations of the applicability of the coherent level mixing model and demonstrate in-situ alteration of the coupling between levels. We further examine the electron spin-nuclear spin (hyperfine) interaction. In the familiar two-electron spin blockade regime, on application of an out-of-dot-plane magnetic field, we observe current switching and hysteresis, and a funnel-like structure in the leakage current, all hallmarks of the hyperfine interaction. The measurements bring to light a strong gate voltage dependence, significant device-to-device variations, and an intricate bias voltage history dependence not accounted for in any existing model. Unexpectedly, we also observe signatures of the hyperfine interaction at high bias, well outside the spin blockade regime. We characterize these features and suggest how the hyperfine interaction

  7. Analysis of the Effects of Streamwise Lift Distribution on Sonic Boom Signature

    Science.gov (United States)

    Yoo, Paul

    2013-01-01

    Investigation of sonic boom has been one of the major areas of study in aeronautics due to the benefits a low-boom aircraft has in both civilian and military applications. This work conducts a numerical analysis of the effects of streamwise lift distribution on the shock coalescence characteristics. A simple wing-canard-stabilator body model is used in the numerical simulation. The streamwise lift distribution is varied by fixing the canard at a deflection angle while trimming the aircraft with the wing and the stabilator at the desired lift coefficient. The lift and the pitching moment coefficients are computed using the Missile DATCOM v. 707. The flow field around the wing-canard- stabilator body model is resolved using the OVERFLOW-2 flow solver. Overset/ chimera grid topology is used to simplify the grid generation of various configurations representing different streamwise lift distributions. The numerical simulations are performed without viscosity unless it is required for numerical stability. All configurations are simulated at Mach 1.4, angle-of-attack of 1.50, lift coefficient of 0.05, and pitching moment coefficient of approximately 0. Four streamwise lift distribution configurations were tested.

  8. Lateral transfer of streamwise momentum caused by a roughness transition across a shallow channel

    NARCIS (Netherlands)

    Vermaas, D.A.; Uijttewaal, W.S.J.; Hoitink, A.J.F.

    2011-01-01

    Research on lateral exchange of streamwise momentum between parallel flows in open channels has mainly been focused on compound channels composed of a main channel and a floodplain, on mixing layer development downstream of river confluences, and on partially vegetated channels. This study aims to

  9. Added mass effect on flow-induced streamwise vibration of a circular cylinder in cross flow

    International Nuclear Information System (INIS)

    Nishihara, Takashi; Kaneko, Shigehiko; Watanabe, Tatsuo

    2004-01-01

    Nuclear power plants include a number of circular cylindrical structures subjected to flow, such as thermometer wells and nozzles. In order to retain their long-term integrity, it is essential to avoid or suppress vortex-induced vibrations. The added mass, one of the essential parameters when evaluating avoidance or suppression of vortex-induced vibrations, is usually considered as almost the same as the displaced fluid mass. However, recent studies have revealed that the added mass coefficient of a cylinder vibrating transversely in a cross flow largely varies and the variation in the added mass coefficient has significant effects on transverse vortex-induced vibrations under low mass-ratio conditions. As for streamwise vortex-induced vibrations, the added mass coefficient has not been determined, and its effects on the streamwise vibrations have been nuclear. In this study, the added mass coefficients of a circular cylinder oscillating in the streamwise direction were obtained by forced oscillation tests in a water tunnel. The results revealed the following properties of the added mass coefficient. The added mass coefficient for the streamwise vibrations varies greatly depending on the reduced velocity V r , and decreases as V r increases, declining to almost 0 at V r > 3.5 - 4.0. In contrast, the added mass coefficient depends less on cylinder amplitude, Reynolds number and the free-end effect of a cylinder. The added mass coefficients were also estimated based on the actual frequency in free-oscillation tests conducted by other researchers under low mass-ratio conditions. They agree well with those obtained by the forced oscillation tests. This result demonstrates that the gradual increase in the actual frequency in the free-oscillation tests can be reasonably explained by the properties of the added mass coefficient. Taking into account of the added mass effects, the validity of the stability criteria for avoiding streamwise vortex-induced vibrations in the

  10. Essential Development of Streamwise Vortical/Secondary Flows in All Ducts with Corners or Slope Discontinuities in Perimeter

    Science.gov (United States)

    Nagib, Hassan; Vidal, Alvaro; Vinuesa, Ricardo; Schlatter, Philipp

    2017-11-01

    Direct numerical simulations of fully-developed turbulent flow through various straight ducts with sharp or rounded corners of various radii were performed to study influence of corner geometry on secondary flows. Unexpectedly, increased rounding of corners in rectangular ducts does not lead to monotonic trend towards pipe case. Instead, secondary vortices relocate close to regions of wall-curvature change. This behavior is connected to inhomogeneous interaction between near-wall bursting events, which are further characterized in this work with definition of their local preferential direction, and vorticity fluxes. Although these motions are relatively weak compared to streamwise velocity their effect on turbulence statistics and shear-stress distribution is very important and has not been sufficiently documented or fully understood. Flow through spanwise-periodic channels, with sinusoidal function to define the geometry of wall, yw = +/- h + A cos(ωz) , was also studied as model flow that is parametrically changed using A and ω, while taking advantage of many resulting symmetries. Consequences on experimental facilities and comparisons between experiments and various numerical and theoretical models are discussed revealing the uniqueness of pipe flow.

  11. Criterion for vortex breakdown on shock wave and streamwise vortex interactions.

    Science.gov (United States)

    Hiejima, Toshihiko

    2014-05-01

    The interactions between supersonic streamwise vortices and oblique shock waves are theoretically and numerically investigated by three-dimensional (3D) Navier-Stokes equations. Based on the two inequalities, a criterion for shock-induced breakdown of the streamwise vortex is proposed. The simple breakdown condition depends on the Mach number, the swirl number, the velocity deficit, and the shock angle. According to the proposed criterion, the breakdown region expands as the Mach number increases. In numerical simulations, vortex breakdown appeared under conditions of multiple pressure increases and the helicity disappeared behind the oblique shock wave along the line of the vortex center. The numerical results are consistent with the predicted breakdown condition at Mach numbers 2.0 and 3.0. This study also found that the axial velocity deficit is important for classifying the breakdown configuration.

  12. Development of Pre-set Counter-rotating Streamwise Vortices in Wavy Channel

    KAUST Repository

    Budiman, A.C.

    2015-10-23

    Development of counter-rotating streamwise vortices in a rectangular channel with one-sided wavy surface has been experimentally quantified using hot-wire anemometry. The wavy surface has fixed amplitude of 3.75 mm. The counter-rotating vortices are pre-set by means of a sawtooth pattern cut at the leading edge of the wavy surface. Variations of the central streamwise velocity Uc with a channel gap H = 35 mm and 50 mm (corresponding to a Reynolds number from 1600 to 4400) change the instability of the flow which can be distinguished from the velocity contours at a certain spanwise plane. The streamwise velocity contours and turbulence intensity for Reynolds number Re = 3100 and H = 35 mm show the disappearance of the mushroom-like vortices prior to turbulence near the second peak of the wavy surface, while for higher Re, this phenomenon occurs earlier. Under certain conditions, for example, for Re = 4400 and H = 50 mm, the splitting of the vortices can also be observed.

  13. Weak currents

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1976-01-01

    A survey of the fundamental ideas on weak currents such as CVC and PCAC and a presentation of the Cabibbo current and the neutral weak currents according to the Salam-Weinberg model and the Glashow-Iliopoulos-Miami model are given [fr

  14. Landau-Zener tunneling in the presence of weak intermolecular interactions in a crystal of Mn4 single-molecule magnets

    Science.gov (United States)

    Wernsdorfer, W.; Bhaduri, S.; Vinslava, A.; Christou, G.

    2005-12-01

    A Mn4 single-molecule magnet (SMM), with a well-isolated spin ground state of S=9/2 , is used as a model system to study Landau-Zener (LZ) tunneling in the presence of weak intermolecular dipolar and exchange interactions. The anisotropy constants D and B are measured with minor hysteresis loops. A transverse field is used to tune the tunnel splitting over a large range. Using the LZ and inverse LZ method, it is shown that these interactions play an important role in the tunnel rates. Three regions are identified: (i) at small transverse fields, tunneling is dominated by single tunnel transitions, (ii) at intermediate transverse fields, the measured tunnel rates are governed by reshuffling of internal fields, and (iii) at larger transverse fields, the magnetization reversal starts to be influenced by the direct relaxation process, and many-body tunnel events may occur. The hole digging method is used to study the next-nearest-neighbor interactions. At small external fields, it is shown that magnetic ordering occurs which does not quench tunneling. An applied transverse field can increase the ordering rate. Spin-spin cross-relaxations, mediated by dipolar and weak exchange interactions, are proposed to explain additional quantum steps.

  15. High-order moments of streamwise fluctuations in a turbulent channel flow with spanwise rotation

    Science.gov (United States)

    Xia, Zhenhua; Brethouwer, Geert; Chen, Shiyi

    2018-02-01

    It is well known that the spanwise rotation in turbulent channel flow alters the mean velocity distribution to a linear law. In the present work, we have studied the higher-order moments of the streamwise fluctuations in a turbulent channel flow with spanwise rotation. Our results show that in a significant part of the channel the 2 p -order moments, raised by the power 1 /p with p =1 ,2 ,...,6 , also follow linear behavior according to 1 /p=ap(y /h ) +bp . Here, u'+ is the streamwise velocity fluctuation normalized by the global friction velocity, h is the channel half width, and bp and ap are the intercept and the slope, respectively, which vary with Reynolds and rotation numbers. The linear regions can be extended by introducing a self-similar scaling, that is, 2 p -order moments as a function of 2 q -order moments. The slopes in the self-similar scaling ap/a1 do not reveal sub-Gaussian behavior as in nonrotating wall-bounded flows, but rather Gaussian or super-Gaussian behaviors.

  16. Weak decays

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1978-11-01

    Lectures are given on weak decays from a phenomenological point of view, emphasizing new results and ideas and the relation of recent results to the new standard theoretical model. The general framework within which the weak decay is viewed and relevant fundamental questions, weak decays of noncharmed hadrons, decays of muons and the tau, and the decays of charmed particles are covered. Limitation is made to the discussion of those topics that either have received recent experimental attention or are relevant to the new physics. (JFP) 178 references

  17. Characterization of counter-rotating streamwise vortices in flat rectangular channel with one-sided wavy wall

    KAUST Repository

    Bouremel, Yann

    2016-11-01

    Particle Image Velocimetry (PIV) has been used to characterize the evolution of counter-rotating streamwise vortices in a rectangular channel with one sided wavy surface. The vortices were created by a uniform set of saw-tooth carved over the leading edge of a flat plate at the entrance of a flat rectangular channel with one-sided wavy wall. PIV measurements were taken over the spanwise and streamwise planes at different locations and at Reynolds number of 2500. Two other Reynolds numbers of 2885 and 3333 have also been considered for quantification purpose. Pairs of counter-rotating streamwise vortices have been shown experimentally to be centred along the spanwise direction at the saw-tooth valley where the vorticity ωz=0ωz=0. It has also been found that the vorticity ωzωz of the pairs of counter-rotating vortices decreases along the streamwise direction, and increases with the Reynolds number. Moreover, different quantifications of such counter-rotating vortices have been discussed such as their size, boundary layer, velocity profile and vorticity. The current study shows that the mixing due to the wall shear stress of counter-rotating streamwise vortices as well as their averaged viscous dissipation rate of kinetic energy decrease over flat and adverse pressure gradient surfaces while increasing over favourable pressure gradient surfaces. Finally, it was also demonstrated that the main direction of stretching is orientated at around 45° with the main flow direction.

  18. Weak interactions

    International Nuclear Information System (INIS)

    Ogava, S.; Savada, S.; Nakagava, M.

    1983-01-01

    The problem of the use of weak interaction laws to study models of elementary particles is discussed. The most typical examples of weak interaction is beta-decay of nucleons and muons. Beta-interaction is presented by quark currents in the form of universal interaction of the V-A type. Universality of weak interactions is well confirmed using as examples e- and μ-channels of pion decay. Hypothesis on partial preservation of axial current is applicable to the analysis of processes with pion participation. In the framework of the model with four flavours lepton decays of hadrons are considered. Weak interaction without lepton participation are also considered. Properties of neutral currents are described briefly

  19. Weak interactions

    International Nuclear Information System (INIS)

    Chanda, R.

    1981-01-01

    The theoretical and experimental evidences to form a basis for Lagrangian Quantum field theory for Weak Interactions are discussed. In this context, gauge invariance aspects of such interactions are showed. (L.C.) [pt

  20. Signature of the CERN GoldenBook at CERN by Peters Higgs British theoretical physicist - He worked on proposals to unify the weak and the electromagnetic forces into a single electroweak theory, The Boson of Higgs.

    CERN Multimedia

    Claudia Marcelloni

    2008-01-01

    Signature of the CERN GoldenBook at CERN by Peters Higgs British theoretical physicist - He worked on proposals to unify the weak and the electromagnetic forces into a single electroweak theory, The Boson of Higgs.

  1. Visit of Peters Higgs at Point 2 ALICE Experiment - British theoretical physicist, He worked on proposals to unify the weak and the electromagnetic forces into a single electroweak theory, The Boson of Higgs.

    CERN Multimedia

    Mona Schweizer

    2008-01-01

    Visit of Peters Higgs at Point 2 ALICE Experiment - British theoretical physicist, He worked on proposals to unify the weak and the electromagnetic forces into a single electroweak theory, The Boson of Higgs.

  2. The Application of Multiobjective Genetic Algorithm to the Parameter Optimization of Single-Well Potential Stochastic Resonance Algorithm Aimed at Simultaneous Determination of Multiple Weak Chromatographic Peaks

    Directory of Open Access Journals (Sweden)

    Haishan Deng

    2014-01-01

    Full Text Available Simultaneous determination of multiple weak chromatographic peaks via stochastic resonance algorithm attracts much attention in recent years. However, the optimization of the parameters is complicated and time consuming, although the single-well potential stochastic resonance algorithm (SSRA has already reduced the number of parameters to only one and simplified the process significantly. Even worse, it is often difficult to keep amplified peaks with beautiful peak shape. Therefore, multiobjective genetic algorithm was employed to optimize the parameter of SSRA for multiple optimization objectives (i.e., S/N and peak shape and multiple chromatographic peaks. The applicability of the proposed method was evaluated with an experimental data set of Sudan dyes, and the results showed an excellent quantitative relationship between different concentrations and responses.

  3. Wall-attached structures of streamwise velocity fluctuations in turbulent boundary layer

    Science.gov (United States)

    Hwang, Jinyul; Sung, Hyung Jin

    2017-11-01

    The wall-attached structures of streamwise velocity fluctuations (u) are explored using direct numerical simulation data of turbulent boundary layer at Reτ = 1000 . We identify the structures of u, which are extended close to the wall. Their height (ly) ranges from the near-wall region to the edge of turbulent boundary layer. They are geometrically self-similar in a sense that the length and width of the structures are proportional to the distance from the wall. The population density of the attached structures shows that the tall attached structures (290 wall. The wall-attached structures of u identified in the present work are a proper candidate for Townsend's attached eddy hypothesis and these structures exist in the low Reynolds number turbulent boundary layer. This work was supported by the Creative Research Initiatives (No. 2017-013369) program of the National Research Foundation of Korea (MSIP) and supported by the Supercomputing Center (KISTI).

  4. Weak interactions

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1978-01-01

    Weak interactions are studied from a phenomenological point of view, by using a minimal number of theoretical hypotheses. Charged-current phenomenology, and then neutral-current phenomenology are discussed. This all is described in terms of a global SU(2) symmetry plus an electromagnetic correction. The intermediate-boson hypothesis is introduced and lower bounds on the range of the weak force are inferred. This phenomenology does not yet reconstruct all the predictions of the conventional SU(2)xU(1) gauge theory. To do that requires an additional assumption of restoration of SU(2) symmetry at asymptotic energies

  5. SPIV investigations of correlation between streamwise vorticity and velocity in the wake of a vortex generator in a boundary layer

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Okulov, Valery; Hansen, Martin Otto Laver

    2013-01-01

    The current work describes the experimental parametric study of streamwise vortices generated in a boundary layer by a rectangular vane (commonly named vortex generator) mounted perpendicularly to the wall and at an angle to the oncoming flow. Stereoscopic Particle Image Velocimetry measurements ...

  6. Magnetic properties of weakly exchange-coupled high spin Co(II) ions in pseudooctahedral coordination evaluated by single crystal X-band EPR spectroscopy and magnetic measurements.

    Science.gov (United States)

    Neuman, Nicolás I; Winkler, Elín; Peña, Octavio; Passeggi, Mario C G; Rizzi, Alberto C; Brondino, Carlos D

    2014-03-03

    We report single-crystal X-band EPR and magnetic measurements of the coordination polymer catena-(trans-(μ2-fumarato)tetraaquacobalt(II)), 1, and the Co(II)-doped Zn(II) analogue, 2, in different Zn:Co ratios. 1 presents two magnetically inequivalent high spin S = 3/2 Co(II) ions per unit cell, named A and B, in a distorted octahedral environment coordinated to four water oxygen atoms and trans coordinated to two carboxylic oxygen atoms from the fumarate anions, in which the Co(II) ions are linked by hydrogen bonds and fumarate molecules. Magnetic susceptibility and magnetization measurements of 1 indicate weak antiferromagnetic exchange interactions between the S = 3/2 spins of the Co(II) ions in the crystal lattice. Oriented single crystal EPR experiments of 1 and 2 were used to evaluate the molecular g-tensor and the different exchange coupling constants between the Co(II) ions, assuming an effective spin S′= 1/2. Unexpectedly, the eigenvectors of the molecular g-tensor were not lying along any preferential bond direction, indicating that, in high spin Co(II) ions in roughly octahedral geometry with approximately axial EPR signals, the presence of molecular pseudo axes in the metal site does not determine preferential directions for the molecular g-tensor. The EPR experiment and magnetic measurements, together with a theoretical analysis relating the coupling constants obtained from both techniques, allowed us to evaluate selectively the exchange coupling constant associated with hydrogen bonds that connect magnetically inequivalent Co(II) ions (|JAB(1/2)| = 0.055(2) cm(–1)) and the exchange coupling constant associated with a fumarate bridge connecting equivalent Co(II) ions (|JAA(1/2)| ≈ 0.25 (1) cm(–1)), in good agreement with the average J(3/2) value determined from magnetic measurements.

  7. Streamwise counter-rotating vortices generated by triangular leading edge pattern in flat plate boundary layer

    KAUST Repository

    Hasheminejad, S. M.

    2016-01-05

    A series of flow visualizations were conducted to qualitatively study the development of streamwise counter-rotating vortices over a flat plate induced by triangular patterns at the leading edge of a flat plate. The experiments were carried out for a Reynolds number based on the pattern wavelength (λ) of 3080. The results depict the onset, development and breakdown of the vortical structures within the flat plate boundary layer. Moreover, the effect of one spanwise array of holes with diameter of 0.2λ (=3 mm) was examined. This investigation was done on two different flat plates with holes placed at the location x/λ = 2 downstream of the troughs and peaks. The presence of holes after troughs does not show any significant effect on the vortical structures. However, the plate with holes after peaks noticeably delays the vortex breakdown. In this case, the “mushroom-like” vortices move away from the wall and propagate downstream with stable vortical structures. The vortex growth is halted further downstream but start to tilt aside.

  8. Streamwise vortices in shear flows: harbingers of transition and the skeleton of coherent structures

    Science.gov (United States)

    Sherwin, Spencer; Hall, Phil

    2010-11-01

    The relationship between asymptotic descriptions of vortex-wave interactions and more recent work on "exact coherent structures" is investigated. We have recently shown that the so-called "lower branch" state, which has been identified as playing a crucial role in these self-sustained processes, is a finite Reynolds number analogue of a Rayleigh vortex-wave interaction with scales appropriately modified from those for external flows to Couette flow the flow of interest here. Remarkable agreement between the asymptotic theory and numerical solutions of the Navier Stokes equations is found even down to relatively small Reynolds numbers thereby suggesting the possible importance of vortex-wave interaction theory in turbulent shear flows. In this paper we will outline the motivation behind the asymptotic analysis and computational modelling which demonstrate the linkage between wave vortex interaction and self sustaining processes. The minimum drag configuration associated with a fixed spanwise wavenumber is also determined as a function of the downstream wavelength and this points to the crucial importance of long waves evolving on the spatial scale appropriate to the roll/streak flow. [4pt] Hall, P. & Sherwin, S.J. 2010, Streamwise vortices in shear flows: harbingers of transition and the skeleton of coherent structures, J. Fluid Mech./ in press.

  9. Streamwise-body-force-model for rapid simulation combining internal and external flow fields

    Directory of Open Access Journals (Sweden)

    Cui Rong

    2016-10-01

    Full Text Available A streamwise-body-force-model (SBFM is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or compressor effects could be simplified as body forces along the streamline. These body forces which are functions of local parameters could be added as source terms in Navier-Stokes equations to replace solid boundary conditions of blades and hubs. The validation of SBFM with uniform inlet and distortion inlet of compressors shows that pressure performance characteristics agree well with experimental data. A three-dimensional simulation of the integration configuration, via a blended wing body aircraft with a distributed propulsion system using the SBFM, has been completed. Lift coefficient and drag coefficient agree well with wind tunnel test results. Results show that to reach the goal of rapid integrated simulation combining internal and external flow fields, the computational fluid dynamics method based on SBFM is reasonable.

  10. Weakly nonparallel and curvature effects on stationary crossflow instability: Comparison of results from multiple-scales analysis and parabolized stability equations

    Science.gov (United States)

    Singer, Bart A.; Choudhari, Meelan; Li, Fei

    1995-01-01

    A multiple-scales approach is used to approximate the effects of nonparallelism and streamwise surface curvature on the growth of stationary crossflow vortices in incompressible, three-dimesional boundary layers. The results agree with results predicted by solving the parabolized stability equations in regions where the nonparallelism is sufficiently weak. As the nonparallelism increases, the agreement between the two approaches worsens. An attempt has been made to quantify the nonparallelism on flow stability in terms of a nondimensional number that describes the rate of change of the mean flow relative to the disturbance wavelength. We find that the above nondimensional number provides useful information about the adequacy of the multiple-scales approximation for different disturbances for a given flow geometry, but the number does not collapse data for different flow geometries onto a single curve.

  11. Single crystal EPR study of the dinuclear Cu(II) complex [Cu(tda)(phen)](2)·H(2)tda (tda = thiodiacetate, phen = phenanthroline): influence of weak interdimeric magnetic interactions.

    Science.gov (United States)

    Neuman, Nicolás I; Perec, Mireille; González, Pablo J; Passeggi, Mario C G; Rizzi, Alberto C; Brondino, Carlos D

    2010-12-23

    We report powder and single crystal EPR measurements of [Cu(tda)(phen)](2)·H(2)tda (tda = thiodiacetate, phen = phenanthroline) at 9.7 GHz. This compound consists of centrosymmetric copper(II) ion dimers, weakly ferromagnetically exchange-coupled (J = +3.2 cm(-1)), in which the dimeric units are linked by hydrophobic chemical paths involving the phen molecules. EPR revealed that the triplet spectra are collapsed by interdimeric exchange interactions mediated by that chemical path. Analysis and simulation of the single crystal EPR spectra were performed using Anderson's exchange narrowing model, together with statistical arguments. This approach allowed us to interpret the spectra modulated by the interdimeric interactions in situations of weak, intermediate, and strong exchange. We evaluated an interdimeric exchange constant J' = 0.0070(3) cm(-1), indicating that hydrophobic paths can transmit weak exchange interactions between centers at relatively long distances of the order of ∼10 Å.

  12. Optimizing Spanwise & Streamwise Spacings of MHK Devices in a Trapezoidal River Channel

    Science.gov (United States)

    Roberts, J. D.; Barco, J.; Johnson, E.; James, S. C.; Jones, C. A.; Jepsen, R. A.

    2011-12-01

    The world is facing significant challenges meeting the energy demands for the future. Growing populations and developing economies as well as increasing energy expenditures highlight the need for a spectrum of energy sources. One promising renewable is marine and hydrokinetic (MHK) energy, which has the potential to make important contributions to future energy portfolios. Increasing interest in MHK energy has spurred to significant research on optimal placement of emerging technologies to maximize energy capture and minimize potential negative effects on the environment. Understanding changes to near- and far-field hydrodynamics is necessary to assess optimal placement. This work demonstrates a newly developed modeling tool that can be used to optimize MHK array layouts to maximize energy capture while minimizing potentially harmful environmental effects. SNL has developed and implemented modifications to an existing flow, sediment-dynamics, and water-quality code (SNL-EFDC) to qualify, quantify, and visualize the interaction and influence of MHK-device operation at a representative site using an appropriate and verified representation of momentum/energy extraction and turbulent wake generation. Various hypothetical MHK array configurations are simulated within a straight rectangular unidirectional flow conditions channel at several water column depths. Results show that the turbine-array power efficiency increased, nonlinearly, as turbine spacing was increased in both the spanwise and streamwise directions as well as when turbines were placed higher in the water column. Contour plots facilitate evaluation of tradeoffs between efficiency and spacing. In addition, results show that flow increases around and over/under the array leading to elevated velocities in the main channel, near the bank, and near the sediment bed, which may have potential implications for bank and bottom erosion, and navigation. SNL-EFDC's "MHK friendly" array-optimization tool is and will

  13. Three-dimensional instability analysis of boundary layers perturbed by streamwise vortices

    Science.gov (United States)

    Martín, Juan A.; Paredes, Pedro

    2017-12-01

    A parametric study is presented for the incompressible, zero-pressure-gradient flat-plate boundary layer perturbed by streamwise vortices. The vortices are placed near the leading edge and model the vortices induced by miniature vortex generators (MVGs), which consist in a spanwise-periodic array of small winglet pairs. The introduction of MVGs has been experimentally proved to be a successful passive flow control strategy for delaying laminar-turbulent transition caused by Tollmien-Schlichting (TS) waves. The counter-rotating vortex pairs induce non-modal, transient growth that leads to a streaky boundary layer flow. The initial intensity of the vortices and their wall-normal distances to the plate wall are varied with the aim of finding the most effective location for streak generation and the effect on the instability characteristics of the perturbed flow. The study includes the solution of the three-dimensional, stationary, streaky boundary layer flows by using the boundary region equations, and the three-dimensional instability analysis of the resulting basic flows by using the plane-marching parabolized stability equations. Depending on the initial circulation and positioning of the vortices, planar TS waves are stabilized by the presence of the streaks, resulting in a reduction in the region of instability and shrink of the neutral stability curve. For a fixed maximum streak amplitude below the threshold for secondary instability (SI), the most effective wall-normal distance for the formation of the streaks is found to also offer the most stabilization of TS waves. By setting a maximum streak amplitude above the threshold for SI, sinuous shear layer modes become unstable, as well as another instability mode that is amplified in a narrow region near the vortex inlet position.

  14. A new strategy for weak events in sparse networks: the first-motion polarity solutions constrained by single-station waveform inversion

    Czech Academy of Sciences Publication Activity Database

    Fojtíková, Lucia; Zahradník, J.

    2014-01-01

    Roč. 85, č. 6 (2014), s. 1265-1274 ISSN 0895-0695 R&D Projects: GA ČR GAP210/12/2336 Institutional support: RVO:67985891 Keywords : weak events * sparse networks * focal mechanism * waveform inversion Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.156, year: 2014 http://srl.geoscienceworld.org/content/85/6/1265.full

  15. Filtered Rayleigh scattering mixing measurements of merging and non-merging streamwise vortex interactions in supersonic flow

    Science.gov (United States)

    Ground, Cody R.; Gopal, Vijay; Maddalena, Luca

    2018-04-01

    By introducing large-scale streamwise vortices into a supersonic flow it is possible to enhance the rate of mixing between two fluid streams. However, increased vorticity content alone does not explicitly serve as a predictor of mixing enhancement. Additional factors, particularly the mutual interactions occurring between neighboring vortical structures, affect the underlying fundamental physics that influence the rate at which the fluids mix. As part of a larger systematic study on supersonic streamwise vortex interactions, this work experimentally quantifies the average rate of mixing of helium and air in the presence of two separate modes of vortex interaction, the merging and non-merging of a pair of co-rotating vortices. In these experiments vortex-generating expansion ramps are placed on a strut injector. The freestream Mach number is set at 2.5 and helium is injected as a passive scalar. Average injectant mole fractions at selected flow planes downstream of the injector are measured utilizing the filtered Rayleigh scattering technique. The filtered Rayleigh scattering measurements reveal that, in the domain surveyed, the merging vortex interaction strongly displaces the plume from its initial horizontal orientation while the non-merging vortex interaction more rapidly mixes the helium and air. The results of the current experiments are consistent with associated knowledge derived from previous analyses of the two studied configurations which have included the detailed experimental characterization of entrainment, turbulent kinetic energy, and vorticity of both modes of vortex interaction.

  16. Development of Streamwise Counter-Rotating Vortices in Flat Plate Boundary Layer Pre-set by Leading Edge Patterns

    KAUST Repository

    Hasheminejad, S.M.

    2017-04-03

    Development of streamwise counter-rotating vortices induced by leading edge patterns with different pattern shape is investigated using hot-wire anemometry in the boundary layer of a flat plate. A triangular, sinusoidal and notched patterns with the same pattern wavelength λ of 15mm and the same pattern amplitude A of 7.5mm were examined for free-stream velocity of 3m/s. The results show a good agreement with earlier studies. The inflection point on the velocity profile downstream of the trough of the patterns at the beginning of the vortex formation indicates that the vortices non-linearly propagate downstream. An additional vortex structure was also observed between the troughs of the notched pattern.

  17. The structure of a three-dimensional boundary layer subjected to streamwise-varying spanwise-homogeneous pressure gradient

    International Nuclear Information System (INIS)

    Bentaleb, Y.; Leschziner, M.A.

    2013-01-01

    Highlights: • We study a spatially-evolving three-dimensional boundary layer. • We impose a streamwise-varying spanwise-homogeneous pressure gradient. • A collateral flow is formed close to the wall, and this is investigated alongside the skewed upper part of the boundary layer. • A wide range of flow-physical properties have been studied. -- Abstract: A spatially-evolving three-dimensional boundary layer, subjected to a streamwise-varying spanwise-homogeneous pressure gradient, equivalent to a body force, is investigated by way of direct numerical simulation. The pressure gradient, prescribed to change its sign half-way along the boundary layer, provokes strong skewing of the velocity vector, with a layer of nearly collateral flow forming close to the wall up to the position of maximum spanwise velocity. A wide range of flow-physical properties have been studied, with particular emphasis on the near-wall layer, including second-moments, major budget contributions and wall-normal two-point correlations of velocity fluctuations and their angles, relative to wall-shear fluctuations. The results illustrate the complexity caused by skewing, including a damping in turbulent mixing and a significant lag between strains and stresses. The study has been undertaken in the context of efforts to develop and test novel hybrid LES–RANS schemes for non-equilibrium near-wall flows, with an emphasis on three-dimensional near-wall straining. Fundamental flow-physical issues aside, the data derived should be of particular relevance to a priori studies of second-moment RANS closure and the development and validation of RANS-type near-wall approximations implemented in LES schemes for high-Reynolds-number complex flows

  18. Decrypting Strong and Weak Single-Walled Carbon Nanotubes Interactions with Mitochondrial Voltage-Dependent Anion Channels Using Molecular Docking and Perturbation Theory.

    Science.gov (United States)

    González-Durruthy, Michael; Werhli, Adriano V; Seus, Vinicius; Machado, Karina S; Pazos, Alejandro; Munteanu, Cristian R; González-Díaz, Humberto; Monserrat, José M

    2017-10-16

    The current molecular docking study provided the Free Energy of Binding (FEB) for the interaction (nanotoxicity) between VDAC mitochondrial channels of three species (VDAC1-Mus musculus, VDAC1-Homo sapiens, VDAC2-Danio rerio) with SWCNT-H, SWCNT-OH, SWCNT-COOH carbon nanotubes. The general results showed that the FEB values were statistically more negative (p  (SWCNT-VDAC1-Mus musculus) > (SWCNT-VDAC1-Homo sapiens) > (ATP-VDAC). More negative FEB values for SWCNT-COOH and OH were found in VDAC2-Danio rerio when compared with VDAC1-Mus musculus and VDAC1-Homo sapiens (p  r 2  > 0.97) was observed between n-Hamada index and VDAC nanotoxicity (or FEB) for the zigzag topologies of SWCNT-COOH and SWCNT-OH. Predictive Nanoparticles-Quantitative-Structure Binding-Relationship models (nano-QSBR) for strong and weak SWCNT-VDAC docking interactions were performed using Perturbation Theory, regression and classification models. Thus, 405 SWCNT-VDAC interactions were predicted using a nano-PT-QSBR classifications model with high accuracy, specificity, and sensitivity (73-98%) in training and validation series, and a maximum AUROC value of 0.978. In addition, the best regression model was obtained with Random Forest (R 2 of 0.833, RMSE of 0.0844), suggesting an excellent potential to predict SWCNT-VDAC channel nanotoxicity. All study data are available at https://doi.org/10.6084/m9.figshare.4802320.v2 .

  19. Fluctuation-induced in-plane conductivity, magnetoconductivity, and diamagnetism of Bi2Sr2CaCu2O8 single crystals in weak magnetic fields

    International Nuclear Information System (INIS)

    Pomar, A.; Ramallo, M.V.; Mosqueira, J.; Torron, C.; Vidal, F.

    1996-01-01

    We report detailed experimental results on the fluctuation-induced in-plane conductivity Δσ ab , magnetoconductivity Δσ ab , and diamagnetism Δχ ab , of high-quality Bi 2 Sr 2 CaCu 2 O 8 crystals. The data were obtained with magnetic fields H applied perpendicularly to the superconducting (CuO 2 ) planes and up to μ 0 H=5 T, which not too close to the transition [for reduced temperatures var-epsilon ≡(T-T C0 )/T C0 approx-gt 10 -2 ] may be considered in the weak magnetic field limit. In the mean field region (MFR) above the transition, these data are analyzed in terms of thermal fluctuations of the superconducting order parameter amplitude (OPF), on the grounds of the existing theoretical approaches for layered superconductors that take into account the presence of two superconducting layers in the layer periodicity length, s, which for these compounds is equal to one-half the crystallographic unit-cell length in the c direction. These results show that, due to its strong var-epsilon dependence, Δσ ab is dramatically affected by the presence of small T C inhomogeneities, associated with small oxygen content inhomogeneities uniformly distributed in the crystals. These inhomogeneity effects are taken into account, consistently with our Δσ ab and Δχ ab results, by using an effective medium approach proposed by Maza and Vidal. In this way, the amplitude and the var-epsilon behavior of the three observables studied here are explained in terms of the direct OPF effects, at a quantitative level, confirming then the absence of appreciable indirect contributions [as, for instance, the Maki-Thompson and the density-of-states (DOS) terms]. (Abstract Truncated)

  20. Weak C* Hopf Symmetry

    OpenAIRE

    Rehren, K. -H.

    1996-01-01

    Weak C* Hopf algebras can act as global symmetries in low-dimensional quantum field theories, when braid group statistics prevents group symmetries. Possibilities to construct field algebras with weak C* Hopf symmetry from a given theory of local observables are discussed.

  1. Weak boson emission in hadron collider processes

    International Nuclear Information System (INIS)

    Baur, U.

    2007-01-01

    The O(α) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(α) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(α) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, tt, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(α) virtual weak radiative corrections partially cancel

  2. Electro-weak theory

    International Nuclear Information System (INIS)

    Deshpande, N.G.

    1980-01-01

    By electro-weak theory is meant the unified field theory that describes both weak and electro-magnetic interactions. The development of a unified electro-weak theory is certainly the most dramatic achievement in theoretical physics to occur in the second half of this century. It puts weak interactions on the same sound theoretical footing as quantum elecrodynamics. Many theorists have contributed to this development, which culminated in the works of Glashow, Weinberg and Salam, who were jointly awarded the 1979 Nobel Prize in physics. Some of the important ideas that contributed to this development are the theory of beta decay formulated by Fermi, Parity violation suggested by Lee and Yang, and incorporated into immensely successful V-A theory of weak interactions by Sudarshan and Marshak. At the same time ideas of gauge invariance were applied to weak interaction by Schwinger, Bludman and Glashow. Weinberg and Salam then went one step further and wrote a theory that is renormalizable, i.e., all higher order corrections are finite, no mean feat for a quantum field theory. The theory had to await the development of the quark model of hadrons for its completion. A description of the electro-weak theory is given

  3. Weak interactions with nuclei

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1983-01-01

    Nuclei provide systems where the strong, electomagnetic, and weak interactions are all present. The current picture of the strong interactions is based on quarks and quantum chromodynamics (QCD). The symmetry structure of this theory is SU(3)/sub C/ x SU(2)/sub W/ x U(1)/sub W/. The electroweak interactions in nuclei can be used to probe this structure. Semileptonic weak interactions are considered. The processes under consideration include beta decay, neutrino scattering and weak neutral-current interactions. The starting point in the analysis is the effective Lagrangian of the Standard Model

  4. Hunting the weak bosons

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The possibility of the production of weak bosons in the proton-antiproton colliding beam facilities which are currently being developed, is discussed. The production, decay and predicted properties of these particles are described. (W.D.L.).

  5. History of Weak Interactions

    Science.gov (United States)

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  6. Unexpected weak interaction

    Science.gov (United States)

    2013-08-01

    Stéphane Coen and Miro Erkintalo from the University of Auckland in New Zealand talk to Nature Photonics about their surprising findings regarding a weak long-range interaction they serendipitously stumbled upon while researching temporal cavity solitons.

  7. Weakly oval electron lense

    International Nuclear Information System (INIS)

    Daumenov, T.D.; Alizarovskaya, I.M.; Khizirova, M.A.

    2001-01-01

    The method of the weakly oval electrical field getting generated by the axially-symmetrical field is shown. Such system may be designed with help of the cylindric form coaxial electrodes with the built-in quadrupole duplet. The singularity of the indicated weakly oval lense consists of that it provides the conducting both mechanical and electronic adjustment. Such lense can be useful for elimination of the near-axis astigmatism in the electron-optical system

  8. Direct numerical simulation of particle-laden turbulent channel flows with two- and four-way coupling effects: budgets of Reynolds stress and streamwise enstrophy

    Energy Technology Data Exchange (ETDEWEB)

    Dritselis, Chris D, E-mail: dritseli@mie.uth.gr [Mechanical Engineering Department, University of Thessaly, Pedion Areos, 38334 Volos (Greece)

    2016-02-15

    The budgets of the Reynolds stress and streamwise enstrophy are evaluated through direct numerical simulations for the turbulent particle-laden flow in a vertical channel with momentum exchange between the two phases. The influence of the dispersed particles on the budgets is examined through a comparison of the particle-free and the particle-laden cases at the same Reynolds number of Re{sub b} = 5600 based on the bulk fluid velocity and the distance between the channel walls. Results are obtained for particle ensembles with four response times in simulations with and without streamwise gravity and inter-particle collisions at average mass (volume) fractions of 0.2 (2.7 × 10{sup −5}) and 0.5 (6.8 × 10{sup −5}). The particle feedback force on the flow of the carrier phase is modeled by a point-force approximation (PSIC-method). It is shown that all the terms in the budgets of the Reynolds stress components are decreased in the presence of particles. The level of reduction depends on the particle response time and it is higher under the effects of gravity and inter-particle collisions. A considerable reduction in all the terms of the streamwise enstrophy budget is also observed. In particular, all production mechanisms, and mainly vortex stretching, are inhibited in the particulate flows and thus the production of streamwise vorticity is significantly damped. A further insight into the direct particle effects on the fluid turbulence is provided by analyzing in detail the fluid–fluid, fluid–particle and particle–particle correlations, and the spectra of the fluid–particle energy exchange rate. The present results indicate that the turbulence production, dissipation and pressure–strain term are generally large quantities, but their summation is relatively small and comparable to the fluid–particle direct energy exchange rate. Consequently, the particle contribution can potentially increase or decrease the fluctuating fluid velocities and eventually

  9. Weak radiative hyperon decays

    International Nuclear Information System (INIS)

    Roberts, B.L.; Booth, E.C.; Gall, K.P.; McIntyre, E.K.; Miller, J.P.; Whitehouse, D.A.; Bassalleck, B.; Hall, J.R.; Larson, K.D.; Wolfe, D.M.; Fickinger, W.J.; Robinson, D.K.; Hallin, A.L.; Hasinoff, M.D.; Measday, D.F.; Noble, A.J.; Waltham, C.E.; Hessey, N.P.; Lowe, J.; Horvath, D.; Salomon, M.

    1990-01-01

    New measurements of the Σ + and Λ weak radiative decays are discussed. The hyperons were produced at rest by the reaction K - p → Yπ where Y = Σ + or Λ. The monoenergetic pion was used to tag the hyperon production, and the branching ratios were determined from the relative amplitudes of Σ + → pγ to Σ + → pπ 0 and Λ → nγ to Λ → nπ 0 . The photons from weak radiative decays and from π 0 decays were detected with modular NaI arrays. (orig.)

  10. Hidden multiparticle excitation in weakly interacting Bose-Einstein Condensate

    OpenAIRE

    Watabe, Shohei

    2017-01-01

    We investigate multiparticle excitation effect on a collective density excitation as well as a single-particle excitation in a weakly interacting Bose--Einstein condensate (BEC). We find that although the weakly interacting BEC offers weak multiparticle excitation spectrum at low temperatures, this multiparticle excitation effect may not remain hidden, but emerges as bimodality in the density response function through the single-particle excitation. Identification of spectra in the BEC betwee...

  11. Identification of multiphasic and weak-link structures in a (La0.94Sr0.06)2CuO4 single crystal by magnetically modulated resistance

    International Nuclear Information System (INIS)

    Magnetically modulated microwave and dc-resistance measurements on a (La 0.94 Sr 0.06 ) 2 CuO 4 crystal show that these techniques, combined with measurement of the corresponding unmodulated resistances, constitute a simple and reliable method for examining superconductor crystals both for the presence of multiple phases with different T c 's and also for the presence of weak links between different superconducting regions. Comparison of the dc and microwave results clearly demonstrates the ability of microwave measurements to assess the experimentally important surface regions of a crystal, in contrast to dc resistance, which probes the best superconducting path through the crystal. These methods can also identify weak links and determine their orientation, as illustrated by the finding of b-axis-oriented weak links in the crystal

  12. Measurement of weak radioactivity

    CERN Document Server

    Theodorsson , P

    1996-01-01

    This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one type can be used, the selection of the most suitable system is shown.

  13. Dark-Matter Particles without Weak-Scale Masses or Weak Interactions

    International Nuclear Information System (INIS)

    Feng, Jonathan L.; Kumar, Jason

    2008-01-01

    We propose that dark matter is composed of particles that naturally have the correct thermal relic density, but have neither weak-scale masses nor weak interactions. These models emerge naturally from gauge-mediated supersymmetry breaking, where they elegantly solve the dark-matter problem. The framework accommodates single or multiple component dark matter, dark-matter masses from 10 MeV to 10 TeV, and interaction strengths from gravitational to strong. These candidates enhance many direct and indirect signals relative to weakly interacting massive particles and have qualitatively new implications for dark-matter searches and cosmological implications for colliders

  14. Weakly relativistic plasma expansion

    Energy Technology Data Exchange (ETDEWEB)

    Fermous, Rachid, E-mail: rfermous@usthb.dz; Djebli, Mourad, E-mail: mdjebli@usthb.dz [Theoretical Physics Laboratory, Faculty of Physics, USTHB, B.P. 32 Bab-Ezzouar, 16079 Algiers (Algeria)

    2015-04-15

    Plasma expansion is an important physical process that takes place in laser interactions with solid targets. Within a self-similar model for the hydrodynamical multi-fluid equations, we investigated the expansion of both dense and under-dense plasmas. The weakly relativistic electrons are produced by ultra-intense laser pulses, while ions are supposed to be in a non-relativistic regime. Numerical investigations have shown that relativistic effects are important for under-dense plasma and are characterized by a finite ion front velocity. Dense plasma expansion is found to be governed mainly by quantum contributions in the fluid equations that originate from the degenerate pressure in addition to the nonlinear contributions from exchange and correlation potentials. The quantum degeneracy parameter profile provides clues to set the limit between under-dense and dense relativistic plasma expansions at a given density and temperature.

  15. Fixed point theorems for generalized weakly contractive mappings

    Directory of Open Access Journals (Sweden)

    Ramendra Krishna Bose

    2009-12-01

    Full Text Available In this paper several fixed point theorems for generalized weakly contractive mappings in a metric space setting are proved. The set of generalized weakly contractive mappings considered in this paper contains the family of weakly contractive mappings as a proper subset. Fixed point theorems for single and multi-valued mappings, approximating scheme for common fixed point for some mappings, and fixed point theorems for fuzzy mappings are presented. It extends the work of several authors including Bose and Roychowdhury.

  16. Weapon of the Weak?

    DEFF Research Database (Denmark)

    Amber, Van der Graaf; Otjes, Simon; Rasmussen, Anne

    2016-01-01

    able to reinvigorate democratic processes by changing inequalities in the landscape of political representation among interest groups. The level of resources held by the interest groups acts as the single most consistent predictor of both the range and volume of their social media use. Interest groups...... if they lose ground to traditional membership groups when the actual volume of Twitter and Facebook use is assessed....

  17. Standard and Null Weak Values

    OpenAIRE

    Zilberberg, Oded; Romito, Alessandro; Gefen, Yuval

    2013-01-01

    Weak value (WV) is a quantum mechanical measurement protocol, proposed by Aharonov, Albert, and Vaidman. It consists of a weak measurement, which is weighed in, conditional on the outcome of a later, strong measurement. Here we define another two-step measurement protocol, null weak value (NVW), and point out its advantages as compared to WV. We present two alternative derivations of NWVs and compare them to the corresponding derivations of WVs.

  18. Weak Measurement and Quantum Correlation

    Indian Academy of Sciences (India)

    Arun Kumar Pati

    The concept of the weak measurements, for the first time, was introduced by Aharonov et al.1. Quantum state is preselected in |ψi〉 and allowed to interact weakly with apparatus. Measurement strength can be tuned and for “small g(t)” it is called 'weak measurement'. With postselection in |ψf 〉, apparatus state is shifted by an ...

  19. Weak openness and almost openness

    Directory of Open Access Journals (Sweden)

    David A. Rose

    1984-01-01

    Full Text Available Weak openness and almost openness for arbitrary functions between topological spaces are defined as duals to the weak continuity of Levine and the almost continuity of Husain respectively. Independence of these two openness conditions is noted and comparison is made between these and the almost openness of Singal and Singal. Some results dual to those known for weak continuity and almost continuity are obtained. Nearly almost openness is defined and used to obtain an improved link from weak continuity to almost continuity.

  20. Weak Weak Lensing : How Accurately Can Small Shears be Measured?

    NARCIS (Netherlands)

    Kuijken, K.

    2006-01-01

    Abstract: Now that weak lensing signals on the order of a percent are actively being searched for (cosmic shear, galaxy-galaxy lensing, large radii in clusters...) it is important to investigate how accurately weak shears can be determined. Many systematic effects are present, and need to be

  1. Master Equation for Streamwise and Vertical Advection and Dispersion of Tracer Pebbles with no Active Layer: Age-based Waiting Time Formulation

    Science.gov (United States)

    Parker, G.

    2014-12-01

    Much of the recent work on advection-dispersion of sediment in rivers has been motivated by, and based on the Master Equation of the Continuous Time Random Walk model. The model, which considers a particle moving through a lattice, has provided the basis for the study of asymptotic forms that include one kind of nonlocality associated with heavy-tailed PDF for particle step length and waiting time. In the case of pebbles moving as bed material load (and thus interacting with the bed), however, the lattice itself varies according to the entrainment and deposition of pebbles, so that CTRW does not formally apply. Here we outline the development of an Exner-based Master Equation for the dispersal of bedload particles. The Master Equation has no active layer, and describes both streamwise and vertical advection-dispersion. Of particular importance is the treatment of waiting time. The formulation is based on the evolution of age structure in population dynamics. As a particle is deposited and buried at some elevation, its age is set to zero; it continues to age in place until the bed erodes down to that level and re-entrains the particle.

  2. Electromagnetic current in weak interactions

    International Nuclear Information System (INIS)

    Ma, E.

    1983-01-01

    In gauge models which unify weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current. The exact nature of such a component can be explored using e + e - experimental data. In recent years, the existence of a new component of the weak interaction has become firmly established, i.e., the neutral-current interaction. As such, it competes with the electromagnetic interaction whenever the particles involved are also charged, but at a very much lower rate because its effective strength is so small. Hence neutrino processes are best for the detection of the neutral-current interaction. However, in any gauge model which unifies weak and electromagnetic interactions, the weak neutral-current interaction also involves the electromagnetic current

  3. Reducing Weak to Strong Bisimilarity in CCP

    Directory of Open Access Journals (Sweden)

    Andrés Aristizábal

    2012-12-01

    Full Text Available Concurrent constraint programming (ccp is a well-established model for concurrency that singles out the fundamental aspects of asynchronous systems whose agents (or processes evolve by posting and querying (partial information in a global medium. Bisimilarity is a standard behavioural equivalence in concurrency theory. However, only recently a well-behaved notion of bisimilarity for ccp, and a ccp partition refinement algorithm for deciding the strong version of this equivalence have been proposed. Weak bisimiliarity is a central behavioural equivalence in process calculi and it is obtained from the strong case by taking into account only the actions that are observable in the system. Typically, the standard partition refinement can also be used for deciding weak bisimilarity simply by using Milner's reduction from weak to strong bisimilarity; a technique referred to as saturation. In this paper we demonstrate that, because of its involved labeled transitions, the above-mentioned saturation technique does not work for ccp. We give an alternative reduction from weak ccp bisimilarity to the strong one that allows us to use the ccp partition refinement algorithm for deciding this equivalence.

  4. Hartman effect and weak measurements that are not really weak

    International Nuclear Information System (INIS)

    Sokolovski, D.; Akhmatskaya, E.

    2011-01-01

    We show that in wave packet tunneling, localization of the transmitted particle amounts to a quantum measurement of the delay it experiences in the barrier. With no external degree of freedom involved, the envelope of the wave packet plays the role of the initial pointer state. Under tunneling conditions such ''self-measurement'' is necessarily weak, and the Hartman effect just reflects the general tendency of weak values to diverge, as postselection in the final state becomes improbable. We also demonstrate that it is a good precision, or a 'not really weak' quantum measurement: no matter how wide the barrier d, it is possible to transmit a wave packet with a width σ small compared to the observed advancement. As is the case with all weak measurements, the probability of transmission rapidly decreases with the ratio σ/d.

  5. The QpWeak experiment

    International Nuclear Information System (INIS)

    Androic, D.; Armstrong, D. S.; Asaturyan, A.; Averett, T.; Balewski, J.; Beaufait, J.; Beminiwattha, R. S.; Benesch, J.; Benmokhtar, F.; Birchall, J.; Carlini, R. D.; Cornejo, J. C.; Covrig, S.; Dalton, M. M.; Davis, C. A.; Deconinck, W.; Diefenbach, J.; Dow, K.; Dowd, J. F.; Dunne, J. A.

    2013-01-01

    In May 2012, the Q p Weak collaboration completed a two year measurement program to determine the weak charge of the proton Q W p = ( 1 - 4sin 2 θ W ) at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q 2  = 0.026 GeV 2 , making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, Q p Weak will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.

  6. Experimental investigations of weak definite and weak indefinite noun phrases.

    Science.gov (United States)

    Klein, Natalie M; Gegg-Harrison, Whitney M; Carlson, Greg N; Tanenhaus, Michael K

    2013-08-01

    Definite noun phrases typically refer to entities that are uniquely identifiable in the speaker and addressee's common ground. Some definite noun phrases (e.g., the hospital in Mary had to go the hospital and John did too) seem to violate this uniqueness constraint. We report six experiments that were motivated by the hypothesis that these "weak definite" interpretations arise in "incorporated" constructions. Experiments 1-3 compared nouns that seem to allow for a weak definite interpretation (e.g., hospital, bank, bus, radio) with those that do not (e.g., farm, concert, car, book). Experiments 1 and 2 used an instruction-following task and picture-judgment task, respectively, to demonstrate that a weak definite need not uniquely refer. In Experiment 3 participants imagined scenarios described by sentences such as The Federal Express driver had to go to the hospital/farm. Scenarios following weak definite noun phrases were more likely to include conventional activities associated with the object, whereas following regular nouns, participants were more likely to imagine scenarios that included typical activities associated with the subject; similar effects were observed with weak indefinites. Experiment 4 found that object-related activities were reduced when the same subject and object were used with a verb that does not license weak definite interpretations. In Experiment 5, a science fiction story introduced an artificial lexicon for novel concepts. Novel nouns that shared conceptual properties with English weak definite nouns were more likely to allow weak reference in a judgment task. Experiment 6 demonstrated that familiarity for definite articles and anti-familiarity for indefinite articles applies to the activity associated with the noun, consistent with predictions made by the incorporation analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Resisting Weakness of the Will.

    Science.gov (United States)

    Levy, Neil

    2011-01-01

    I develop an account of weakness of the will that is driven by experimental evidence from cognitive and social psychology. I will argue that this account demonstrates that there is no such thing as weakness of the will: no psychological kind corresponds to it. Instead, weakness of the will ought to be understood as depletion of System II resources. Neither the explanatory purposes of psychology nor our practical purposes as agents are well-served by retaining the concept. I therefore suggest that we ought to jettison it, in favour of the vocabulary and concepts of cognitive psychology.

  8. Weakly infinite-dimensional spaces

    International Nuclear Information System (INIS)

    Fedorchuk, Vitalii V

    2007-01-01

    In this survey article two new classes of spaces are considered: m-C-spaces and w-m-C-spaces, m=2,3,...,∞. They are intermediate between the class of weakly infinite-dimensional spaces in the Alexandroff sense and the class of C-spaces. The classes of 2-C-spaces and w-2-C-spaces coincide with the class of weakly infinite-dimensional spaces, while the compact ∞-C-spaces are exactly the C-compact spaces of Haver. The main results of the theory of weakly infinite-dimensional spaces, including classification via transfinite Lebesgue dimensions and Luzin-Sierpinsky indices, extend to these new classes of spaces. Weak m-C-spaces are characterised by means of essential maps to Henderson's m-compacta. The existence of hereditarily m-strongly infinite-dimensional spaces is proved.

  9. The weak decay of hypernuclei

    International Nuclear Information System (INIS)

    Franklin, G.B.

    1986-01-01

    Hypernuclei whose ground states are stable against strong decay are used to study two-baryon weak interactions. A review of th existing experimental data, including recent results from the AGS on /sub Λ/ 12 C and /sub Λ/ 11 B, shows that the lifetimes and branching ratios can be used to test the effective weak Hamiltonians used in the rate calculations. 10 refs., 4 figs

  10. Weakly Supervised Deep Detection Networks

    OpenAIRE

    Bilen, Hakan; Vedaldi, Andrea

    2015-01-01

    Weakly supervised learning of object detection is an important problem in image understanding that still does not have a satisfactory solution. In this paper, we address this problem by exploiting the power of deep convolutional neural networks pre-trained on large-scale image-level classification tasks. We propose a weakly supervised deep detection architecture that modifies one such network to operate at the level of image regions, performing simultaneously region selection and classificati...

  11. Weakly compact operators and interpolation

    OpenAIRE

    Maligranda, Lech

    1992-01-01

    The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...

  12. Weak Deeply Virtual Compton Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Ales Psaker; Wolodymyr Melnitchouk; Anatoly Radyushkin

    2007-03-01

    We extend the analysis of the deeply virtual Compton scattering process to the weak interaction sector in the generalized Bjorken limit. The virtual Compton scattering amplitudes for the weak neutral and charged currents are calculated at the leading twist within the framework of the nonlocal light-cone expansion via coordinate space QCD string operators. Using a simple model, we estimate cross sections for neutrino scattering off the nucleon, relevant for future high intensity neutrino beam facilities.

  13. Weak interactions of elementary particles

    CERN Document Server

    Okun, Lev Borisovich

    1965-01-01

    International Series of Monographs in Natural Philosophy, Volume 5: Weak Interaction of Elementary Particles focuses on the composition, properties, and reactions of elementary particles and high energies. The book first discusses elementary particles. Concerns include isotopic invariance in the Sakata model; conservation of fundamental particles; scheme of isomultiplets in the Sakata model; universal, unitary-symmetric strong interaction; and universal weak interaction. The text also focuses on spinors, amplitudes, and currents. Wave function, calculation of traces, five bilinear covariants,

  14. Acute muscular weakness in children

    Directory of Open Access Journals (Sweden)

    Ricardo Pablo Javier Erazo Torricelli

    Full Text Available ABSTRACT Acute muscle weakness in children is a pediatric emergency. During the diagnostic approach, it is crucial to obtain a detailed case history, including: onset of weakness, history of associated febrile states, ingestion of toxic substances/toxins, immunizations, and family history. Neurological examination must be meticulous as well. In this review, we describe the most common diseases related to acute muscle weakness, grouped into the site of origin (from the upper motor neuron to the motor unit. Early detection of hyperCKemia may lead to a myositis diagnosis, and hypokalemia points to the diagnosis of periodic paralysis. Ophthalmoparesis, ptosis and bulbar signs are suggestive of myasthenia gravis or botulism. Distal weakness and hyporeflexia are clinical features of Guillain-Barré syndrome, the most frequent cause of acute muscle weakness. If all studies are normal, a psychogenic cause should be considered. Finding the etiology of acute muscle weakness is essential to execute treatment in a timely manner, improving the prognosis of affected children.

  15. Search for weakly decaying b -flavored pentaquarks

    Science.gov (United States)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Atzeni, M.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Balagura, V.; Baldini, W.; Baranov, A.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Baryshnikov, F.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Beiter, A.; Bel, L. J.; Beliy, N.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Beranek, S.; Berezhnoy, A.; Bernet, R.; Berninghoff, D.; Bertholet, E.; Bertolin, A.; Betancourt, C.; Betti, F.; Bettler, M. O.; van Beuzekom, M.; Bezshyiko, Ia.; Bifani, S.; Billoir, P.; Birnkraut, A.; Bizzeti, A.; Bjørn, M.; Blake, T.; Blanc, F.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bordyuzhin, I.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Brodzicka, J.; Brundu, D.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Byczynski, W.; Cadeddu, S.; Cai, H.; Calabrese, R.; Calladine, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Cattaneo, M.; Cavallero, G.; Cenci, R.; Chamont, D.; Chapman, M. G.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S. F.; Chitic, S.-G.; Chobanova, V.; Chrzaszcz, M.; Chubykin, A.; Ciambrone, P.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collins, P.; Colombo, T.; Comerma-Montells, A.; Contu, A.; Coombs, G.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Currie, R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Da Silva, C. L.; Dall'Occo, E.; Dalseno, J.; Davis, A.; De Aguiar Francisco, O.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Serio, M.; De Simone, P.; Dean, C. T.; Decamp, D.; Del Buono, L.; Dembinski, H.-P.; Demmer, M.; Dendek, A.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Nezza, P.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Douglas, L.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Durante, P.; Durham, J. M.; Dutta, D.; Dzhelyadin, R.; Dziewiecki, M.; Dziurda, A.; Dzyuba, A.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fazzini, D.; Federici, L.; Ferguson, D.; Fernandez, G.; Fernandez Declara, P.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Lopes, L.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fontana, M.; Fontanelli, F.; Forty, R.; Franco Lima, V.; Frank, M.; Frei, C.; Fu, J.; Funk, W.; Furfaro, E.; Färber, C.; Gabriel, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianı, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Govorkova, E.; Grabowski, J. P.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greim, R.; Griffith, P.; Grillo, L.; Gruber, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hamilton, B.; Han, X.; Hancock, T. H.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Hasse, C.; Hatch, M.; He, J.; Hecker, M.; Heinicke, K.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hopchev, P. H.; Hu, W.; Huang, W.; Huard, Z. C.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hutchcroft, D.; Ibis, P.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kazeev, N.; Kecke, M.; Keizer, F.; Kelsey, M.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Klimkovich, T.; Koliiev, S.; Kolpin, M.; Kopecna, R.; Koppenburg, P.; Kosmyntseva, A.; Kotriakhova, S.; Kozeiha, M.; Kravchuk, L.; Kreps, M.; Kress, F.; Krokovny, P.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, P.-R.; Li, T.; Li, Y.; Li, Z.; Liang, X.; Likhomanenko, T.; Lindner, R.; Lionetto, F.; Lisovskyi, V.; Liu, X.; Loh, D.; Loi, A.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Macko, V.; Mackowiak, P.; Maddrell-Mander, S.; Maev, O.; Maguire, K.; Maisuzenko, D.; Majewski, M. W.; Malde, S.; Malecki, B.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Marangotto, D.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marinangeli, M.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurice, E.; Maurin, B.; Mazurov, A.; McCann, M.; McNab, A.; McNulty, R.; Mead, J. V.; Meadows, B.; Meaux, C.; Meier, F.; Meinert, N.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Millard, E.; Minard, M.-N.; Minzoni, L.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Mombächer, T.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morello, M. J.; Morgunova, O.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, T. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Nogay, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Ossowska, A.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palutan, M.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, M.; Patrignani, C.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Pereima, D.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pietrzyk, G.; Pikies, M.; Pinci, D.; Pisani, F.; Pistone, A.; Piucci, A.; Placinta, V.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poli Lener, M.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Ponce, S.; Popov, A.; Popov, D.; Poslavskii, S.; Potterat, C.; Price, E.; Prisciandaro, J.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Pullen, H.; Punzi, G.; Qian, W.; Qin, J.; Quagliani, R.; Quintana, B.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Ratnikov, F.; Raven, G.; Ravonel Salzgeber, M.; Reboud, M.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Robbe, P.; Robert, A.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rogozhnikov, A.; Roiser, S.; Rollings, A.; Romanovskiy, V.; Romero Vidal, A.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Ruiz Vidal, J.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarpis, G.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schreiner, H. F.; Schubiger, M.; Schune, M. H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepulveda, E. S.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, I. T.; Smith, J.; Smith, M.; Soares Lavra, l.; Sokoloff, M. D.; Soler, F. J. P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stepanova, M.; Stevens, H.; Stone, S.; Storaci, B.; Stracka, S.; Stramaglia, M. E.; Straticiuc, M.; Straumann, U.; Sun, J.; Sun, L.; Swientek, K.; Syropoulos, V.; Szumlak, T.; Szymanski, M.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Tourinho Jadallah Aoude, R.; Tournefier, E.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Usachov, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagner, A.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Verlage, T. A.; Vernet, M.; Vesterinen, M.; Viana Barbosa, J. V.; Vieira, D.; Vieites Diaz, M.; Viemann, H.; Vilasis-Cardona, X.; Vitti, M.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Walsh, J.; Wang, J.; Wang, Y.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Weisser, C.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Winn, M.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wyllie, K.; Xie, Y.; Xu, M.; Xu, Q.; Xu, Z.; Xu, Z.; Yang, Z.; Yang, Z.; Yao, Y.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhu, X.; Zhukov, V.; Zonneveld, J. B.; Zucchelli, S.; LHCb Collaboration

    2018-02-01

    Investigations of the existence of pentaquark states containing a single b (anti)quark decaying weakly into four specific final states J /ψ K+π-p , J /ψ K-π-p , J /ψ K-π+p , and J /ψ ϕ (1020 )p are reported. The data sample corresponds to an integrated luminosity of 3.0 fb-1 in 7 and 8 TeV p p collisions acquired with the LHCb detector. Signals are not observed and upper limits are set on the product of the production cross section times branching fraction with respect to that of the Λb0.

  16. Precision frequency measurements with interferometric weak values

    International Nuclear Information System (INIS)

    Starling, David J.; Dixon, P. Ben; Jordan, Andrew N.; Howell, John C.

    2010-01-01

    We demonstrate an experiment which utilizes a Sagnac interferometer to measure a change in optical frequency of 129 ± 7 kHz/√(Hz) with only 2 mW of continuous-wave, single-mode input power. We describe the measurement of a weak value and show how even higher-frequency sensitivities may be obtained over a bandwidth of several nanometers. This technique has many possible applications, such as precision relative frequency measurements and laser locking without the use of atomic lines.

  17. Cosmology with weak lensing surveys

    International Nuclear Information System (INIS)

    Munshi, Dipak; Valageas, Patrick; Waerbeke, Ludovic van; Heavens, Alan

    2008-01-01

    Weak gravitational lensing is responsible for the shearing and magnification of the images of high-redshift sources due to the presence of intervening matter. The distortions are due to fluctuations in the gravitational potential, and are directly related to the distribution of matter and to the geometry and dynamics of the Universe. As a consequence, weak gravitational lensing offers unique possibilities for probing the Dark Matter and Dark Energy in the Universe. In this review, we summarise the theoretical and observational state of the subject, focussing on the statistical aspects of weak lensing, and consider the prospects for weak lensing surveys in the future. Weak gravitational lensing surveys are complementary to both galaxy surveys and cosmic microwave background (CMB) observations as they probe the unbiased non-linear matter power spectrum at modest redshifts. Most of the cosmological parameters are accurately estimated from CMB and large-scale galaxy surveys, so the focus of attention is shifting to understanding the nature of Dark Matter and Dark Energy. On the theoretical side, recent advances in the use of 3D information of the sources from photometric redshifts promise greater statistical power, and these are further enhanced by the use of statistics beyond two-point quantities such as the power spectrum. The use of 3D information also alleviates difficulties arising from physical effects such as the intrinsic alignment of galaxies, which can mimic weak lensing to some extent. On the observational side, in the next few years weak lensing surveys such as CFHTLS, VST-KIDS and Pan-STARRS, and the planned Dark Energy Survey, will provide the first weak lensing surveys covering very large sky areas and depth. In the long run even more ambitious programmes such as DUNE, the Supernova Anisotropy Probe (SNAP) and Large-aperture Synoptic Survey Telescope (LSST) are planned. Weak lensing of diffuse components such as the CMB and 21 cm emission can also

  18. Impact of the initial streamwise inclination of a double jet emitted within a cool crossflow on its temperature field and pollutants dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Radhouane, A.; Mahjoub Said, Nejla; Mhiri, H. [Ecole Nationale d' Ingenieurs de Monastir, Unite de Thermique et Thermodynamique des Procedes Industriels, Monastir (Tunisia); Palec, G. le; Bournot, P. [IUSTI, UMR 6595, Technopole de Chateau-Gombert, Marseille (France)

    2009-04-15

    An experimental study and a numerical modeling are carried out simultaneously on a twin inclined jets' configuration issuing into a cooler crossflow. The main purpose of this study is to track the overall evolution of the jets among the surrounding flow and then determine the thermal and mass transfer features that characterize the resulting flowfield. The experimental data are depicted by means of a particle image velocimetry technique; whereas the numerical three-dimensional model is simulated through the resolution of the different governing Navier-Stokes' equations by means of the finite volume method. Two different closure models were tested: the standard k-{epsilon} model and the Reynolds stress model (RSM) second order model. The introduction of the latter in such a configuration brings some valuable improvement since it allows the detection of the slightest variations within the domain and then describes the least occurring mechanisms. The confrontation of the differently processed numerical results with the experimentally tracked data comforted our opinion since it proved the better efficiency of the RSM model for the description of the handled flow; that's why we adopted it for the rest of the paper. Once the validation obtained, we proceeded to the evaluation of the influence of the initial streamwise inclination of the emitted jets on the engendered thermal field and on the pollutants' dispersion. For the matter, we tested the following angles: 30 , 45 , 60 and 90 . After that, we represented the temperature variation along different directions in order to detail its behavior in all of them and at different levels. This characterization is highly recommended since it may promote the efficiency of several applications (mainly the cooling applications). We also evaluated the influence of this same parameter; the initial inclination; on the pollutants' dispersion due to the high and alarming importance of the problem on the

  19. Functional limb weakness and paralysis.

    Science.gov (United States)

    Stone, J; Aybek, S

    2016-01-01

    Functional (psychogenic) limb weakness describes genuinely experienced limb power or paralysis in the absence of neurologic disease. The hallmark of functional limb weakness is the presence of internal inconsistency revealing a pattern of symptoms governed by abnormally focused attention. In this chapter we review the history and epidemiology of this clinical presentation as well as its subjective experience highlighting the detailed descriptions of authors at the end of the 19th and early 20th century. We discuss the relevance that physiological triggers such as injury and migraine and psychophysiological events such as panic and dissociation have to understanding of mechanism and treatment. We review many different positive diagnostic features, their basis in neurophysiological testing and present data on sensitivity and specificity. Diagnostic bedside tests with the most evidence are Hoover's sign, the hip abductor sign, drift without pronation, dragging gait, give way weakness and co-contraction. © 2016 Elsevier B.V. All rights reserved.

  20. Plane waves with weak singularities

    International Nuclear Information System (INIS)

    David, Justin R.

    2003-03-01

    We study a class of time dependent solutions of the vacuum Einstein equations which are plane waves with weak null singularities. This singularity is weak in the sense that though the tidal forces diverge at the singularity, the rate of divergence is such that the distortion suffered by a freely falling observer remains finite. Among such weak singular plane waves there is a sub-class which does not exhibit large back reaction in the presence of test scalar probes. String propagation in these backgrounds is smooth and there is a natural way to continue the metric beyond the singularity. This continued metric admits string propagation without the string becoming infinitely excited. We construct a one parameter family of smooth metrics which are at a finite distance in the space of metrics from the extended metric and a well defined operator in the string sigma model which resolves the singularity. (author)

  1. Cosmology and the weak interaction

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N ν ∼ 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs

  2. Nonlinear waves and weak turbulence

    CERN Document Server

    Zakharov, V E

    1997-01-01

    This book is a collection of papers on dynamical and statistical theory of nonlinear wave propagation in dispersive conservative media. Emphasis is on waves on the surface of an ideal fluid and on Rossby waves in the atmosphere. Although the book deals mainly with weakly nonlinear waves, it is more than simply a description of standard perturbation techniques. The goal is to show that the theory of weakly interacting waves is naturally related to such areas of mathematics as Diophantine equations, differential geometry of waves, Poincaré normal forms, and the inverse scattering method.

  3. Weak interactions at high energies

    International Nuclear Information System (INIS)

    Ellis, J.

    1978-08-01

    Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references

  4. Voltage Weak DC Distribution Grids

    NARCIS (Netherlands)

    Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.

    2017-01-01

    This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of

  5. Second threshold in weak interactions

    NARCIS (Netherlands)

    Veltman, M.J.G.

    1977-01-01

    The point of view that weak interactions must have a second threshold below 300 – 600 GeV is developed. Above this threshold new physics must come in. This new physics may be the Higgs system, or some other nonperturbative system possibly having some similarities to the Higgs system. The limit of

  6. Coverings, Networks and Weak Topologies

    Czech Academy of Sciences Publication Activity Database

    Dow, A.; Junnila, H.; Pelant, Jan

    2006-01-01

    Roč. 53, č. 2 (2006), s. 287-320 ISSN 0025-5793 R&D Projects: GA ČR GA201/97/0216 Institutional research plan: CEZ:AV0Z10190503 Keywords : Banach spaces * weak topologies * networks topologies Subject RIV: BA - General Mathematics

  7. Weak lensing and dark energy

    International Nuclear Information System (INIS)

    Huterer, Dragan

    2002-01-01

    We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak lensing convergence power spectrum. Some dark-energy models predict additional clustering on very large scales, but this probably cannot be detected by weak lensing alone due to cosmic variance. With reasonable prior information on other cosmological parameters, we find that a survey covering 1000 sq deg down to a limiting magnitude of R=27 can impose constraints comparable to those expected from upcoming type Ia supernova and number-count surveys. This result, however, is contingent on the control of both observational and theoretical systematics. Concentrating on the latter, we find that the nonlinear power spectrum of matter perturbations and the redshift distribution of source galaxies both need to be determined accurately in order for weak lensing to achieve its full potential. Finally, we discuss the sensitivity of the three-point statistics to dark energy

  8. Submanifolds weakly associated with graphs

    Indian Academy of Sciences (India)

    theory by defining submanifolds weakly associated with graphs. We prove that, in a local sense, every submanifold satisfies such an association, and other general results. Finally, we study submanifolds associated with graphs either in low dimensions or belonging to some special families. Keywords. Almost Hermitian ...

  9. Submanifolds weakly associated with graphs

    Indian Academy of Sciences (India)

    We establish an interesting link between differential geometry and graph theory by defining submanifolds weakly associated with graphs. We prove that, in a local sense, every submanifold satisfies such an association, and other general results. Finally, we study submanifolds associated with graphs either in low ...

  10. Weakness acquired in the intensive care unit. Incidence, risk factors and their association with inspiratory weakness. Observational cohort study.

    Science.gov (United States)

    Ballve, Ladislao Pablo Diaz; Dargains, Nahuel; Inchaustegui, José García Urrutia; Bratos, Antonella; Percaz, Maria de Los Milagros; Ardariz, Cesar Bueno; Cagide, Sabrina; Balestrieri, Carolina; Gamarra, Claudio; Paz, Dario; Rotela, Eliana; Muller, Sebastian; Bustos, Fernando; Castro, Ricard Aranda; Settembrino, Esteban

    2017-01-01

    This paper sought to determine the accumulated incidence and analyze the risk factors associated with the development of weakness acquired in the intensive care unit and its relationship to inspiratory weakness. We conducted a prospective cohort study at a single center, multipurpose medical-surgical intensive care unit. We included adult patients who required mechanical ventilation ≥ 24 hours between July 2014 and January 2016. No interventions were performed. Demographic data, clinical diagnoses, the factors related to the development of intensive care unit -acquired weakness, and maximal inspiratory pressure were recorded. Of the 111 patients included, 66 developed intensive care unit -acquired weakness, with a cumulative incidence of 40.5% over 18 months. The group with intensive care unit-acquired weakness were older (55.9 ± 17.6 versus 45.8 ± 16.7), required more mechanical ventilation (7 [4 - 10] days versus 4 [2 - 7.3] days), and spent more time in the intensive care unit (15.5 [9.2 - 22.8] days versus 9 [6 - 14] days). More patients presented with delirium (68% versus 39%), hyperglycemia > 3 days (84% versus 59%), and positive balance > 3 days (73.3% versus 37%). All comparisons were significant at p 5 days as independent predictors of intensive care unit-acquired weakness. Low maximal inspiratory pressure was associated with intensive care unit-acquired weakness (p intensive care unit-acquired weakness. The intensive care unit acquired weakness is a condition with a high incidence in our environment. The development of intensive care unit-acquired weakness was associated with age, delirium, hyperglycemia, and mechanical ventilation > 5 days. The maximum inspiratory pressure value of ≥ 36cmH2O was associated with a high diagnostic value to exclude the presence of intensive care unit -acquired weakness.

  11. Weak neutral-current interactions

    International Nuclear Information System (INIS)

    Barnett, R.M.

    1978-08-01

    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z 0 boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references

  12. History of the weak interactions

    International Nuclear Information System (INIS)

    Lee, T.D.

    1987-01-01

    At the 'Jackfest' marking the 65th birthday of Jack Steinberger (see July/August 1986 issue, page 29), T.D. Lee gave an account of the history of the weak interactions. This edited version omits some of Lee's tributes to Steinberger, but retains the impressive insight into the subtleties of a key area of modern physics by one who played a vital role in its development. (orig./HSI).

  13. Weak neutral-current interactions

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, R.M.

    1978-08-01

    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z/sup 0/ boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references. (JFP)

  14. Weakly Iπg-Closed Sets

    OpenAIRE

    Ravi, O.

    2015-01-01

    called weakly Iπg-open sets in ideal topological spaces is introduced and the notion of weakly Iπg-closed sets in ideal topologicalspaces is studied. The relationships of weakly Iπg-closed sets andvarious properties of weakly Iπg-closed sets are investigated

  15. Blind quantum computing with weak coherent pulses.

    Science.gov (United States)

    Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony

    2012-05-18

    The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ϵ blindness for UBQC, in analogy to the concept of ϵ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ϵ-blind UBQC for any ϵ>0, even if the channel between the client and the server is arbitrarily lossy.

  16. Blind Quantum Computing with Weak Coherent Pulses

    Science.gov (United States)

    Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony

    2012-05-01

    The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ɛ blindness for UBQC, in analogy to the concept of ɛ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ɛ-blind UBQC for any ɛ>0, even if the channel between the client and the server is arbitrarily lossy.

  17. Meson exchange and neutral weak currents

    Energy Technology Data Exchange (ETDEWEB)

    Beck, D.H. [Univ. of Illinois, Urbana, IL (United States)

    1994-04-01

    Measurements of parity-violating electron scattering asymmetries to determine weak neutral currents in nuclei will be effected by the presence of meson exchange currents. Present low momentum transfer calculations, based on a flavor independent framework, show these effects to be small. In general, however, as the momentum transfer increases to values typical of deep-inelastic scattering, fragmentation functions show a clear flavor dependence. It is suggested that a good experimental starting point for understanding the flavor dependence of meson production and exchange currents is the Q{sup 2} dependence of parity-violating asymmetry in inclusive single pion electroproduction. A CEBAF facility with doubled energy is necessary to approach momentum transfers where this process begins to scale.

  18. Weak decays of heavy quarks

    International Nuclear Information System (INIS)

    Gaillard, M.K.

    1978-08-01

    The properties that may help to identify the two additional quark flavors that are expected to be discovered. These properties are lifetime, branching ratios, selection rules, and lepton decay spectra. It is also noted that CP violation may manifest itself more strongly in heavy particle decays than elsewhere providing a new probe of its origin. The theoretical progress in the understanding of nonleptonic transitions among lighter quarks, nonleptonic K and hyperon decay amplitudes, omega minus and charmed particle decay predictions, and lastly the Kobayashi--Maskawa model for the weak coupling of heavy quarks together with the details of its implications for topology and bottomology are treated. 48 references

  19. Strengths, weaknesses, opportunities and threats

    DEFF Research Database (Denmark)

    Bull, Joseph William; Jobstvogt, N.; Böhnke-Henrichs, A.

    2016-01-01

    . Such an assessment could form the basis for improving ES thinking, further embedding it into environmental decisions and management.The Young Ecosystem Services Specialists (YESS) completed a Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis of ES through YESS member surveys. Strengths include the approach...... environmental awareness. Threats include resistance to change, and difficulty with interdisciplinary collaboration. Consideration of SWOT themes suggested five strategic areas for developing and implementing ES.The ES concept could improve decision-making related to natural resource use, and interpretation...

  20. Time—periodic weak solutions

    Directory of Open Access Journals (Sweden)

    Eliana Henriques de Brito

    1990-01-01

    Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.

  1. Political corruption and weak state

    Directory of Open Access Journals (Sweden)

    Stojiljković Zoran

    2013-01-01

    Full Text Available The author starts from the hypothesis that it is essential for the countries of the region to critically assess the synergy established between systemic, political corruption and a selectively weak, “devious” nature of the state. Moreover, the key dilemma is whether the expanded practice of political rent seeking supports the conclusion that the root of all corruption is in the very existence of the state - particularly in excessive, selective and deforming state interventions and benefits that create a fertile ground for corruption? The author argues that the destructive combination of weak government and rampant political corruption is based on scattered state intervention, while also rule the parties cartel in the executive branch subordinate to parliament, the judiciary and the police. Corrupt exchange takes place with the absence of strong institutional framework and the precise rules of the political and electoral games, control of public finances and effective political and anti-monopoly legislation and practice included. Exit from the current situation can be seen in the realization of effective anti­corruption strategy that integrates preventive and repressive measures and activities and lead to the establishment of principles of good governance. [Projekat Ministarstva nauke Republike Srbije, br. 179076: Politički identitet Srbije u regionalnom i globalnom kontekstu

  2. Weak lensing and cosmological investigation

    CERN Document Server

    Acquaviva, V

    2005-01-01

    In the last few years the scientific community has been dealing with the challenging issue of identifying the dark energy component. We regard weak gravitational lensing as a brand new, and extremely important, tool for cosmological investigation in this field. In fact, the features imprinted on the cosmic microwave background radiation by the lensing from the intervening distribution of matter represent a pretty unbiased estimator, and can thus be used for putting constraints on different dark energy models. This is true in particular for the magnetic-type B-modes of CMB polarization, whose unlensed spectrum at large multipoles (l approximately=1000) is very small even in presence of an amount of gravitational waves as large as currently allowed by the experiments: therefore, on these scales the lensing phenomenon is the only responsible for the observed power, and this signal turns out to be a faithful tracer of the dark energy dynamics. We first recall the formal apparatus of the weak lensing in extended t...

  3. Weak transitions in lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Maturana, G.

    1984-01-01

    Some techniques to calculate the effects of the strong interactions on the matrix elements of weak processes are described. The lattice formulation of Quantum Chromodynamics is used to account for the low energy gluons, and the corresponding numerical methods are explained. The high energy contributions are included in effective lagrangians and the problem of matching the different scales related to the renormalization of the operators and wavefunctions is also discussed. The ..delta..l = 1/2 enhancement rule and the K/sup 0/-anti-K/sup 0/ are used to illustrate these techniques and the results of a numerical calculation is reported. The values obtained are very encouraging and they certainly show good qualitative agreement with the experimental values. The emphasis is on general techniques, and in particular, several improvements to this particular calculation are proposed.

  4. Weak KAM for commuting Hamiltonians

    International Nuclear Information System (INIS)

    Zavidovique, M

    2010-01-01

    For two commuting Tonelli Hamiltonians, we recover the commutation of the Lax–Oleinik semi-groups, a result of Barles and Tourin (2001 Indiana Univ. Math. J. 50 1523–44), using a direct geometrical method (Stoke's theorem). We also obtain a 'generalization' of a theorem of Maderna (2002 Bull. Soc. Math. France 130 493–506). More precisely, we prove that if the phase space is the cotangent of a compact manifold then the weak KAM solutions (or viscosity solutions of the critical stationary Hamilton–Jacobi equation) for G and for H are the same. As a corollary we obtain the equality of the Aubry sets and of the Peierls barrier. This is also related to works of Sorrentino (2009 On the Integrability of Tonelli Hamiltonians Preprint) and Bernard (2007 Duke Math. J. 136 401–20)

  5. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  6. Weakly distributive modules. Applications to supplement submodules

    Indian Academy of Sciences (India)

    Abstract. In this paper, we define and study weakly distributive modules as a proper generalization of distributive modules. We prove that, weakly distributive supplemented modules are amply supplemented. In a weakly distributive supplemented module every submodule has a unique coclosure. This generalizes a result of ...

  7. Fault zone fabric and fault weakness

    NARCIS (Netherlands)

    Collettini, C.; Niemeijer, A.; Viti, C.; Marone, C.

    2009-01-01

    Geological and geophysical evidence suggests that some crustal faults are weak1–6 compared to laboratory measurements of frictional strength7. Explanations for fault weakness include the presence of weak minerals4, high fluid pressures within the fault core8,9 and dynamic processes such as

  8. Strong Plate, Weak Slab Dichotomy

    Science.gov (United States)

    Petersen, R. I.; Stegman, D. R.; Tackley, P.

    2015-12-01

    Models of mantle convection on Earth produce styles of convection that are not observed on Earth.Moreover non-Earth-like modes, such as two-sided downwellings, are the de facto mode of convection in such models.To recreate Earth style subduction, i.e. one-sided asymmetric recycling of the lithosphere, proper treatment of the plates and plate interface are required. Previous work has identified several model features that promote subduction. A free surface or pseudo-free surface and a layer of material with a relatively low strength material (weak crust) allow downgoing plates to bend and slide past overriding without creating undue stress at the plate interface. (Crameri, et al. 2012, GRL)A low viscosity mantle wedge, possibly a result of slab dehydration, decouples the plates in the system. (Gerya et al. 2007, Geo)Plates must be composed of material which, in the case of the overriding plate, are is strong enough to resist bending stresses imposed by the subducting plate and yet, as in the case of the subducting plate, be weak enough to bend and subduct when pulled by the already subducted slab. (Petersen et al. 2015, PEPI) Though strong surface plates are required for subduction such plates may present a problem when they encounter the lower mantle.As the subducting slab approaches the higher viscosity, lower mantle stresses are imposed on the tip.Strong slabs transmit this stress to the surface.There the stress field at the plate interface is modified and potentially modifies the style of convection. In addition to modifying the stress at the plate interface, the strength of the slab affects the morphology of the slab at the base of the upper mantle. (Stegman, et al 2010, Tectonophysics)Slabs that maintain a sufficient portion of their strength after being bent require high stresses to unbend or otherwise change their shape.On the other hand slabs that are weakened though the bending process are more amenable to changes in morphology. We present the results of

  9. Hidden multiparticle excitation in a weakly interacting Bose-Einstein condensate

    Science.gov (United States)

    Watabe, Shohei

    2018-03-01

    We investigate multiparticle excitation effect on a collective density excitation as well as a single-particle excitation in a weakly interacting Bose-Einstein condensate (BEC). We find that although the weakly interacting BEC offers weak multiparticle excitation spectrum at low temperatures, this multiparticle excitation effect may not remain hidden, but emerges as bimodality in the density response function through the single-particle excitation. Identification of spectra in the BEC between the single-particle excitation and the density excitation is also assessed at nonzero temperatures, which has been known to be unique nature in the BEC at absolute zero temperature.

  10. A Universe without Weak Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Harnik, Roni; Kribs, Graham D.; Perez, Gilad

    2006-04-07

    A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.

  11. Measurements of weak conversion lines

    International Nuclear Information System (INIS)

    Feoktistov, A.I.; Frantsev, Yu.E.

    1979-01-01

    Described is a new methods for measuring weak conversion lines with the help of the β spectrometer of the π √ 2 type which permits to increase the reliability of the results obtained. According to this method the measurements were carried out by short series with the storage of the information obtained on the punched tape. The spectrometer magnetic field was stabilized during the measuring of the conversion spectra with the help of three nmr recorders. Instead of the dependence of the pulse calculation rate on the magnetic field value was measured the dependence of the calculation rate on the value of the voltage applied between the source and the spectrometer chamber. A short description of the automatic set-up for measuring conversion lines according to the method proposed is given. The main set-up elements are the voltage multiplexer timer, printer, scaler and the pulse analyzer. With the help of the above methods obtained is the K 1035, 8 keV 182 Ta line. It is obtained as a result of the composition of 96 measurement series. Each measurement time constitutes 640 s 12 points are taken on the line

  12. Methodology for analyzing weak spectra

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Swainson, I.P.

    2000-02-01

    There is considerable interest in quantifying radionuclide transfer between environmental compartments. However, in many cases, it can be a challenge to detect concentrations of gamma-emitting radionuclides due to their low levels in environmental samples. As a result, it is valuable to develop analytical protocols to ensure consistent analysis of the areas under weak peaks. The current study has focused on testing how reproducibly peak areas and baselines can be determined using two analytical approaches. The first approach, which can be carried out using Maestro software, involves extracting net counts under a curve without fitting a functional form to the peak, whereas the second approach, which is used by most other peak fitting programs, determines net counts from spectra by fitting a Gaussian form to the data. It was found that the second approach produces more consistent peak area and baseline measurements, with the ability to de-convolute multiple, overlapping peaks. In addition, programs, such as Peak Fit, which can be used to fit a form to spectral data, often provide goodness of fit analyses, since the Gaussian form can be described using a characteristic equation against which peak data can be tested for their statistical significance. (author)

  13. The Geometry And Significance Of Weak Energy

    CERN Document Server

    Parks, A D

    2000-01-01

    Summary: The theory of weak values for quantum mechanical observables has come to serve as a useful basis for contemporary discussions concerning such varied topics as the tunnelling-time controversy and quantum stochastic processes. An intrinsic complex-valued weak energy has recently been observed experimentally and reported in the literature. In this paper it is shown that: (a) the real and imaginary valued parts of this weak energy have geometric interpretations related to a phase acquired from parallel transport in Hilbert space and the variational dynamics occurring in the associated projective Hilbert space, respectively; (b) the weak energy defines functions which translate correlation amplitudes and probabilities in time; (c) correlation probabilities can be controlled by manipulating the weak energy and there exists a condition of weak stationarity that guarantees their time invariance; and (d) a time-weak energy uncertainty relation of the usual form prevails when a suitable set of dynamical constr...

  14. Mappings on weakly Lindelöf and weakly regular-Lindel¨of spaces

    Directory of Open Access Journals (Sweden)

    Anwar Jabor Fawakhreh

    2011-10-01

    Full Text Available In this paper we study the effect of mappings and some decompositions of continuity on weakly Lindelöf spaces and weakly regular-Lindelöf spaces. We show that some mappings preserve these topological properties. We also show that the image of a weakly Lindelöf space (resp. weakly regular-Lindelöf space under an almost continuous mapping is weakly Lindelöf (resp. weakly regular-Lindelöf. Moreover, the image of a weakly regular-Lindelöf space under a precontinuous and contracontinuousmapping is Lindelöf.

  15. Classical field approach to quantum weak measurements.

    Science.gov (United States)

    Dressel, Justin; Bliokh, Konstantin Y; Nori, Franco

    2014-03-21

    By generalizing the quantum weak measurement protocol to the case of quantum fields, we show that weak measurements probe an effective classical background field that describes the average field configuration in the spacetime region between pre- and postselection boundary conditions. The classical field is itself a weak value of the corresponding quantum field operator and satisfies equations of motion that extremize an effective action. Weak measurements perturb this effective action, producing measurable changes to the classical field dynamics. As such, weakly measured effects always correspond to an effective classical field. This general result explains why these effects appear to be robust for pre- and postselected ensembles, and why they can also be measured using classical field techniques that are not weak for individual excitations of the field.

  16. Weakly distributive modules. Applications to supplement submodules

    Indian Academy of Sciences (India)

    It is well-known that, if f : M → N is an isomorphism, then there is a one-to-one corres- pondence between the submodules of M and the submodules of N. Therefore, any module. (lattice) isomorphic to a weakly distributive module, is itself weakly distributive. Lemma 2.1. Let M be a weakly distributive module and f : M → N be ...

  17. Robust weak measurements on finite samples

    International Nuclear Information System (INIS)

    Tollaksen, Jeff

    2007-01-01

    A new weak measurement procedure is introduced for finite samples which yields accurate weak values that are outside the range of eigenvalues and which do not require an exponentially rare ensemble. This procedure provides a unique advantage in the amplification of small nonrandom signals by minimizing uncertainties in determining the weak value and by minimizing sample size. This procedure can also extend the strength of the coupling between the system and measuring device to a new regime

  18. Are weak and electromagnetic interactions unified

    International Nuclear Information System (INIS)

    Dombey, N.

    1983-01-01

    This chapter examines how well the standard electroweak model agrees with experiment. Attempts to explain to a nonparticle physicist why weak and electromagnetic interactions are unified. Discusses the Glashow model (unified SU(2)xU(1)); some basic questions; an alternative viewpoint; unified theories; non-unified theories; and weak interactions as strong interactions. Concludes that SU(2)xU(1) is a good phenomenological model for weak and electromagnetic interactions in the energy region accessible to experiment

  19. Numerical test of weak turbulence theory

    Science.gov (United States)

    Payne, G. L.; Nicholson, D. R.; Shen, Mei-Mei

    1989-01-01

    The analytic theory of weak Langmuir turbulence is well known, but very little has previously been done to compare its predictions with numerical solutions of the basic dynamical evolution equations. In this paper, numerical solutions of the statistical weak turbulence theory are compared with numerical solutions of the Zakharov model of Langmuir turbulence, and good agreement in certain regimes of very weak field strength is found.

  20. Robot locomotion on weak ground

    Science.gov (United States)

    Qian, Feifei; Li, Chen; Umbanhowar, Paul; Goldman, Daniel

    2012-11-01

    Natural substrates like sand, soil, and leaf litter vary widely in penetration resistance. Little is known about how animals (and increasingly robots) respond to this variation. To address this deficit, we built an air fluidized bed trackway, in which we control penetration resistance of 1mm granular substrates down to zero by increasing the upward flow rate, Q , to the fluidization transition. Using a 2 . 5 kg bio-inspired hexapedal robot as our model locomotor, we systematically study how locomotion performance (average forward speed, v) varies with penetration resistance, limb kinematics, and foot morphology. Average robot speed decreases with increasing Q, and decreases faster for robots with higher leg frequency or narrower leg width. A previously developed model, which captured the robot's performance on granular media with Q = 0 , also captures the observed performance for weakened states with Q > 0 . A single dimensionless control parameter from the model, which combines gait and ground parameters, determines v for all penetration resistances. Our ground control technique and modeling approach provide a way to probe and understand the limits of locomotor performance on yielding substrates.

  1. Interferometric Measurement of the Current-Phase Relationship of a Superfluid Weak Link

    Directory of Open Access Journals (Sweden)

    S. Eckel

    2014-09-01

    Full Text Available Weak connections between superconductors or superfluids can differ from classical links due to quantum coherence, which allows flow without resistance. Transport properties through such weak links can be described with a single function, the current-phase relationship, which serves as the quantum analog of the current-voltage relationship. Here, we present a technique for inteferometrically measuring the current-phase relationship of superfluid weak links. We interferometrically measure the phase gradient around a ring-shaped superfluid Bose-Einstein condensate containing a rotating weak link, allowing us to identify the current flowing around the ring. While our Bose-Einstein condensate weak link operates in the hydrodynamic regime, this technique can be extended to all types of weak links (including tunnel junctions in any phase-coherent quantum gas. Moreover, it can also measure the current-phase relationships of excitations. Such measurements may open new avenues of research in quantum transport.

  2. A note on Weak Stability Boundaries

    OpenAIRE

    García González, Fernando; Gómez Muntané, Gerard

    2006-01-01

    This paper is devoted to clarify the algorithmic definition of the weak stability boundary in the framework of the planar Restricted Three Body Problem. The role of the invariant hyperbolic manifolds associated to the central manifolds of the libration points L1 and L2, as boundary of the weak stability region, is shown Peer Reviewed

  3. Staggering towards a calculation of weak amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, S.R.

    1988-09-01

    An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs.

  4. Staggering towards a calculation of weak amplitudes

    International Nuclear Information System (INIS)

    Sharpe, S.R.

    1988-09-01

    An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs

  5. Weak interaction: past answers, present questions

    International Nuclear Information System (INIS)

    Ne'eman, Y.

    1977-02-01

    A historical sketch of the weak interaction is presented. From beta ray to pion decay, the V-A theory of Marshak and Sudarshan, CVC principle of equivalence, universality as an algebraic condition, PCAC, renormalized weak Hamiltonian in the rehabilitation of field theory, and some current issues are considered in this review. 47 references

  6. Common fixed points for weakly compatible maps

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    flood of papers involving contractive definition that do not require the continuity of T . This result was further generalized and extended in various ways by many authors. On the other hand Sessa [11] defined weak commutativity and proved common fixed point theorem for weakly commuting maps. Further Jungck [5] ...

  7. Optimization of strong and weak coordinates

    NARCIS (Netherlands)

    Swart, M.; Bickelhaupt, F.M.

    2006-01-01

    We present a new scheme for the geometry optimization of equilibrium and transition state structures that can be used for both strong and weak coordinates. We use a screening function that depends on atom-pair distances to differentiate strong coordinates from weak coordinates. This differentiation

  8. Moving Beyond Weak Identifiers for Proxemic Interaction

    DEFF Research Database (Denmark)

    Sørensen, Henrik; Kjeldskov, Jesper

    2013-01-01

    is significantly closer than what is actually the case. This makes the smartphone a weak identifier for applications that need to track persons. With a focus on feasible interaction design, we present a concept and prototype of a platform, which seek to support proxemic interaction beyond weak identifiers...

  9. Towards a classification of weak hand holds

    NARCIS (Netherlands)

    Kimmelman, V.; Sáfár, A.; Crasborn, O.

    2016-01-01

    The two symmetrical manual articulators (the hands) in signed languages are a striking modalityspecific phonetic property. The weak hand can maintain the end position of an articulation while the other articulator continues to produce additional signs. This weak hand spreading (hold) has been

  10. Weak measurements with a qubit meter

    DEFF Research Database (Denmark)

    Wu, Shengjun; Mølmer, Klaus

    2009-01-01

    We derive schemes to measure the so-called weak values of quantum system observables by coupling of the system to a qubit meter system. We highlight, in particular, the meaning of the imaginary part of the weak values, and show how it can be measured directly on equal footing with the real part...

  11. Inelastic multiple scattering of interacting bosons in weak random potentials

    International Nuclear Information System (INIS)

    Geiger, Tobias

    2013-01-01

    Within the present thesis we develop a diagrammatic scattering theory for interacting bosons in a three-dimensional, weakly disordered potential. Based on a microscopic N-body scattering theory, we identify the relevant diagrams including elastic and inelastic collision processes that are sufficient to describe quantum transport in the regime of weak disorder. By taking advantage of the statistical properties of the weak disorder potential, we demonstrate how the N-body dynamics can be reduced to a nonlinear integral equation of Boltzmann type for the single-particle diffusive flux. A presently available alternative description - based on the Gross-Pitaevskii equation - only includes elastic collisions. In contrast, we show that far from equilibrium the presence of inelastic collisions - even for weak interaction strength - must be accounted for and can induce the full thermalization of the single-particle current. In addition, we also determine the coherent corrections to the incoherent transport, leading to the effect of coherent backscattering. For the first time, we are able to analyze the influence of inelastic collisions on the coherent backscattering signal, which lead to an enhancement of the backscattered cone in a narrow spectral window, even for increasing non-linearity. With a short recollection of the presently available experimental techniques we furthermore show how an immediate implementation of our suggested setup with confined Bose-Einstein condensates can be accomplished. Thereby, the emergence of collective and/or thermodynamic behavior from fundamental, microscopic constituents can also be assessed experimentally. In a second part of this thesis, we present first results for light scattering off strongly interacting Rydberg atoms trapped in a one-dimensional, chain-like configuration. In order to monitor the time-dependence of this interacting many-body system, we devise a weak measurement scenario for which we derive a master equation for the

  12. Persisting weakness after withdrawal of a statin.

    Science.gov (United States)

    Mygland, Åse; Ljøstad, Unn; Krossnes, Bård Kronen

    2014-04-08

    An 81-year-old woman treated with simvastatin for several years followed by atorvastatin for about 1 year presented with fatigue, weakness and unsteady gait. The finding of elevated creatine kinase (CK) and symmetric muscle weakness around shoulders and hips led to suspicion of a toxic statin-associated myopathy. Atorvastatin was withdrawn, but her weakness persisted. Owing to persisting weakness, an autoimmune myopathy (myositis) was suspected, but initially disregarded since a muscle biopsy showed necrotic muscle fibres without inflammatory cell infiltrates and myositis-specific autoantibodies were absent. After 18 months with slowly progressive weakness and increasing CK values, awareness of new knowledge about autoimmunity as a cause of necrotic myopathy, led to a successful treatment trial with intravenous immunoglobulines, followed by steroids and metothrexate. Antibodies to the target enzyme of statins (HMGCR (3-hydroksy-3-methylglutaryl-coenzyme A reductase)) were detected in her serum, and she was diagnosed with autoimmune necrotic myositis probably triggered by atorvastatin.

  13. On weakly hyperbolic spaces and a convergence-extension theorem in weakly hyperbolic spaces

    International Nuclear Information System (INIS)

    Duc, Pham Viet

    2002-11-01

    In this article we prove some properties of the weakly hyperbolic spaces. Moreover, a convergence-extension theorem for analytic hypersurfaces (not necessarily with normal crossings) in weakly hyperbolic spaces is given. (author)

  14. Weak correlation of starch and volume in synchronized photosynthetic cells

    Science.gov (United States)

    Rading, M. Michael; Sandmann, Michael; Steup, Martin; Chiarugi, Davide; Valleriani, Angelo

    2015-01-01

    In cultures of unicellular algae, features of single cells, such as cellular volume and starch content, are thought to be the result of carefully balanced growth and division processes. Single-cell analyses of synchronized photoautotrophic cultures of the unicellular alga Chlamydomonas reinhardtii reveal, however, that the cellular volume and starch content are only weakly correlated. Likewise, other cell parameters, e.g., the chlorophyll content per cell, are only weakly correlated with cell size. We derive the cell size distributions at the beginning of each synchronization cycle considering growth, timing of cell division and daughter cell release, and the uneven division of cell volume. Furthermore, we investigate the link between cell volume growth and starch accumulation. This work presents evidence that, under the experimental conditions of light-dark synchronized cultures, the weak correlation between both cell features is a result of a cumulative process rather than due to asymmetric partition of biomolecules during cell division. This cumulative process necessarily limits cellular similarities within a synchronized cell population.

  15. Weak Solution and Weakly Uniformly Bounded Solution of Impulsive Heat Equations Containing “Maximum” Temperature

    Directory of Open Access Journals (Sweden)

    Oyelami, Benjamin Oyediran

    2013-09-01

    Full Text Available In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.

  16. Weak and electromagnetic interactions in nuclei

    International Nuclear Information System (INIS)

    Klapdor, H.V.

    1986-01-01

    The International Symposium W.E.I.N. 1986 brought together leading experts in the fields of nuclear and elementary particle physics, astrophysics and cosmology. In addition to current problems in nuclear physics (weak and electromagnetic nuclear properties, electroweak interactions in nuclei, exotic nuclei) this book presents fascinating contributions that arise from the interaction among these fields: lepton number violation and neutrino mass; muon physics; weak interactions and fundamental symmetries; fundamental decays; basic experiments for GUTs; weak interactions and astrophysics; GUTs, SUSYs and the early Universe. The book demonstrates that in this context nuclear physics promises exciting future developments. (orig.)

  17. Current problems in the weak interactions

    Energy Technology Data Exchange (ETDEWEB)

    Pais, A

    1977-01-01

    Some reasons are discussed showing why the recent SU(2) x U(1) gauge theory of weak and electromagnetic interactions is not a complete theory of these interactions, Lepton theory, charm, and the CP problem are considered. 60 references. (JFP)

  18. Current problems in the weak interactions

    International Nuclear Information System (INIS)

    Pais, A.

    1977-01-01

    Some reasons are discussed showing why the recent SU(2) x U(1) gauge theory of weak and electromagnetic interactions is not a complete theory of these interactions, Lepton theory, charm, and the CP problem are considered. 60 references

  19. Weakly supervised object detection with posterior regularization

    OpenAIRE

    Bilen, Hakan; Pedersoli, Marco; Tuytelaars, Tinne

    2014-01-01

    Bilen H., Pedersoli M., Tuytelaars T., ''Weakly supervised object detection with posterior regularization'', 25th British machine vision conference - BMVC 2014, 12 pp., September 1-5, 2014, Nottingham, UK.

  20. About some distinguishing features of weak interactions

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    1999-01-01

    It is shown that, in contrast to strong and electromagnetic theories, additive conserved numbers (such as lepton, aromatic and another numbers) and γ 5 anomaly do not appear in the standard weak interaction theory. It means that in this interaction the additive numbers cannot be conserved. These results are the consequence of specific character of the weak interaction: the right components of spinors do not participate in this interaction. The schemes of violation of the aromatic and lepton numbers were considered

  1. Drift waves in a weakly ionized plasma

    DEFF Research Database (Denmark)

    Popovic, M.; Melchior, H.

    1968-01-01

    A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated.......A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated....

  2. Weakly Secure Regenerating Codes for Distributed Storage

    OpenAIRE

    Kadhe, Swanand; Sprintson, Alex

    2014-01-01

    We consider the problem of secure distributed data storage under the paradigm of \\emph{weak security}, in which no \\emph{meaningful information} is leaked to the eavesdropper. More specifically, the eavesdropper cannot get any information about any individual message file or a small group of files. The key benefit of the weak security paradigm is that it incurs no loss in the storage capacity, which makes it practically appealing. In this paper, we present a coding scheme, using a coset codin...

  3. Markovian bridges: Weak continuity and pathwise constructions

    OpenAIRE

    Chaumont, Loïc; Uribe Bravo, Gerónimo

    2011-01-01

    A Markovian bridge is a probability measure taken from a disintegration of the law of an initial part of the path of a Markov process given its terminal value. As such, Markovian bridges admit a natural parameterization in terms of the state space of the process. In the context of Feller processes with continuous transition densities, we construct by weak convergence considerations the only versions of Markovian bridges which are weakly continuous with respect to their parameter. We use this ...

  4. Joint and weak measurements on qubit systems

    International Nuclear Information System (INIS)

    O'Brien, J.L.; Pryde, G.J.; Bartlett, S.D.; Ralph, T.C.; Wiseman, H.M.; White, A.G.

    2005-01-01

    Full text: Along with the well-known concept of projective measurements, quantum mechanics allows various kinds of generalized measurement operators. Two important examples are: joint measurements on two or more quantum systems that cannot be achieved by local operations (LOCC); and weak measurements that obtain less information about a system than does a projective measurement, but with correspondingly less disturbance. Unlike the result of a strong measurement, the average value of a weak measurement of an observable (its weak value), when followed by projective postselection in a complementary basis, can lie outside the range of eigenvalues. This discrepancy is not observed in analogous classical measurements. Weak values aid the resolution of quantum paradoxes, and can simplify analysis of weakly coupled systems. We use a generalized measurement device to measure the weak value of a photon's polarization in the horizontal/vertical basis (the Stokes operator S1 = |H> weak up to 47, outside the usual range -1 ≤ S1 ≤ 1. Unlike previous observations of weak values, our measurement works by entangling two separate systems, and thus can only be described by quantum theory, not a classical wave theory. Also, we have used a two-qubit joint measurement based on a controlled-NOT gate by which certain twoqubit unentangled states can be more reliably distinguished than by using LOCC. We quantify this using a payoff function, for which the optimal LOCC measurement attains 2/3, and our experimental measurement attains 0.72 ± 0.02, close to the global optimum of 3/4. (author)

  5. Synchronization of weakly coupled canard oscillators

    OpenAIRE

    Köksal Ersöz, Elif; Desroches, Mathieu; Krupa, Martin

    2017-01-01

    International audience; Synchronization has been studied extensively in the context of weakly coupled oscillators using the so-called phase response curve (PRC) which measures how a change of the phase of an oscillator is affected by a small perturbation. This approach was based upon the work of Malkin, and it has been extended to relaxation oscillators. Namely, synchronization conditions were established under the weak coupling assumption, leading to a criterion for the existence of synchron...

  6. Attending to weak signals: the leader's challenge.

    Science.gov (United States)

    Kerfoot, Karlene

    2005-12-01

    Halverson and Isham (2003) quote sources that report the accidental death rate of simply being in a hospital is " ... four hundred times more likely than your risk of death from traveling by train, forty times higher than driving a car, and twenty times higher than flying in a commercial aircraft" (p. 13). High-reliability organizations such as nuclear power plants and aircraft carriers have been pioneers in the business of recognizing weak signals. Weike and Sutcliffe (2001) note that high-reliability organizations distinguish themselves from others because of their mindfulness which enables them to see the significance of weak signals and to give strong interventions to weak signals. To act mindfully, these organizations have an underlying mental model of continually updating, anticipating, and focusing the possibility of failure using the intelligence that weak signals provides. Much of what happens is unexpected in health care. However, with a culture that is continually looking for weak signals, and intervenes and rescues when these signals are detected, the unexpected happens less often. This is the epitome of how leaders can build a culture of safety that focuses on recognizing the weak signals to manage the unforeseen.

  7. Importance of weak minerals on earthquake mechanics

    Science.gov (United States)

    Kaneki, S.; Hirono, T.

    2017-12-01

    The role of weak minerals such as smectite and talc on earthquake mechanics is one of the important issues, and has been debated for recent several decades. Traditionally weak minerals in fault have been reported to weaken fault strength causing from its low frictional resistance. Furthermore, velocity-strengthening behavior of such weak mineral (talc) is considered to responsible for fault creep (aseismic slip) in the San Andreas fault. In contrast, recent studies reported that large amount of weak smectite in the Japan Trench could facilitate gigantic seismic slip during the 2011 Tohoku-oki earthquake. To investigate the role of weak minerals on rupture propagation process and magnitude of slip, we focus on the frictional properties of carbonaceous materials (CMs), which is the representative weak materials widely distributed in and around the convergent boundaries. Field observation and geochemical analyses revealed that graphitized CMs-layer is distributed along the slip surface of a fossil plate-subduction fault. Laboratory friction experiments demonstrated that pure quartz, bulk mixtures with bituminous coal (1 wt.%), and quartz with layered coal samples exhibited almost similar frictional properties (initial, yield, and dynamic friction). However, mixtures of quartz (99 wt.%) and layered graphite (1 wt.%) showed significantly lower initial and yield friction coefficient (0.31 and 0.50, respectively). Furthermore, the stress ratio S, defined as (yield stress-initial stress)/(initial stress-dynamic stress), increased in layered graphite samples (1.97) compared to quartz samples (0.14). Similar trend was observed in smectite-rich fault gouge. By referring the reported results of dynamic rupture propagation simulation using S ratio of 1.4 (typical value for the Japan Trench) and 2.0 (this study), we confirmed that higher S ratio results in smaller slip distance by approximately 20 %. On the basis of these results, we could conclude that weak minerals have lower

  8. SIMULATION OF SUBGRADE EMBANKMENT ON WEAK BASE

    Directory of Open Access Journals (Sweden)

    V. D. Petrenko

    2015-08-01

    Full Text Available Purpose. This article provides: the question of the sustainability of the subgrade on a weak base is considered in the paper. It is proposed to use the method of jet grouting. Investigation of the possibility of a weak base has an effect on the overall deformation of the subgrade; the identification and optimization of the parameters of subgrade based on studies using numerical simulation. Methodology. The theoretical studies of the stress-strain state of the base and subgrade embankment by modeling in the software package LIRA have been conducted to achieve this goal. Findings. After making the necessary calculations perform building fields of a subsidence, borders cramped thickness, bed’s coefficients of Pasternak and Winkler. The diagrams construction of vertical stress performs at any point of load application. Also, using the software system may perform peer review subsidence, rolls railroad tracks in natural and consolidated basis. Originality. For weak soils is the most appropriate nonlinear model of the base with the existing areas of both elastic and limit equilibrium, mixed problem of the theory of elasticity and plasticity. Practical value. By increasing the load on the weak base as a result of the second track construction, adds embankment or increasing axial load when changing the rolling stock process of sedimentation and consolidation may continue again. Therefore, one of the feasible and promising options for the design and reconstruction of embankments on weak bases is to strengthen the bases with the help of jet grouting. With the expansion of the railway infrastructure, increasing speed and weight of the rolling stock is necessary to ensure the stability of the subgrade on weak bases. LIRA software package allows you to perform all the necessary calculations for the selection of a proper way of strengthening weak bases.

  9. Merging weak and QCD showers with matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Jesper Roy [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden); Prestel, Stefan [SLAC National Accelerator Laboratory, Menlo Park, CA (United States)

    2016-01-15

    We present a consistent way of combining associated weak boson radiation in hard dijet events with hard QCD radiation in Drell-Yan-like scatterings. This integrates multiple tree-level calculations with vastly different cross sections, QCD- and electroweak parton-shower resummation into a single framework. The new merging strategy is implemented in the Pythia event generator and predictions are confronted with LHC data. Improvements over the previous strategy are observed. Results of the new electroweak-improved merging at a future 100 TeV proton collider are also investigated. (orig.)

  10. Statistical approach of weakly nonlinear ablative Rayleigh-Taylor instability

    International Nuclear Information System (INIS)

    Garnier, J.; Masse, L.

    2005-01-01

    A weakly nonlinear model is proposed for the Rayleigh-Taylor instability in presence of ablation and thermal transport. The nonlinear effects for a single-mode disturbance are computed, included the nonlinear correction to the exponential growth of the fundamental modulation. Mode coupling in the spectrum of a multimode disturbance is thoroughly analyzed by a statistical approach. The exponential growth of the linear regime is shown to be reduced by the nonlinear mode coupling. The saturation amplitude is around 0.1λ for long wavelengths, but higher for short instable wavelengths in the ablative regime

  11. A search for weakly decaying $b$-flavored pentaquarks

    CERN Document Server

    Aaij, Roel; LHCb Collaboration; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Alfonso Albero, Alejandro; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Atzeni, Michele; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Balagura, Vladislav; Baldini, Wander; Baranov, Alexander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baryshnikov, Fedor; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Beiter, Andrew; Bel, Lennaert; Beliy, Nikita; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Beranek, Sarah; Berezhnoy, Alexander; Bernet, Roland; Berninghoff, Daniel; Bertholet, Emilie; Bertolin, Alessandro; Betancourt, Christopher; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Birnkraut, Alex; Bizzeti, Andrea; Bjørn, Mikkel; Blake, Thomas; Blanc, Frederic; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bordyuzhin, Igor; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Brodzicka, Jolanta; Brundu, Davide; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Byczynski, Wiktor; Cadeddu, Sandro; Cai, Hao; Calabrese, Roberto; Calladine, Ryan; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Cattaneo, Marco; Cavallero, Giovanni; Cenci, Riccardo; Chamont, David; Chapman, Matthew George; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu Faye; Chitic, Stefan-Gabriel; Chobanova, Veronika; Chrzaszcz, Marcin; Chubykin, Alexsei; Ciambrone, Paolo; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collins, Paula; Colombo, Tommaso; Comerma-Montells, Albert; Contu, Andrea; Coombs, George; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Da Silva, Cesar Luiz; Dall'Occo, Elena; Dalseno, Jeremy; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Del Buono, Luigi; Dembinski, Hans Peter; Demmer, Moritz; Dendek, Adam; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Nezza, Pasquale; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Douglas, Lauren; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Durante, Paolo; Durham, John Matthew; Dutta, Deepanwita; Dzhelyadin, Rustem; Dziewiecki, Michal; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fazzini, Davide; Federici, Luca; Ferguson, Dianne; Fernandez, Gerard; Fernandez Declara, Placido; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Lopes, Lino; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Funk, Wolfgang; Furfaro, Emiliano; Färber, Christian; Gabriel, Emmy; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, Vladimir; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Govorkova, Ekaterina; Grabowski, Jascha Peter; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greim, Roman; Griffith, Peter; Grillo, Lucia; Gruber, Lukas; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hamilton, Brian; Han, Xiaoxue; Hancock, Thomas Henry; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Hasse, Christoph; Hatch, Mark; He, Jibo; Hecker, Malte; Heinicke, Kevin; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hopchev, Plamen Hristov; Hu, Wenhua; Huang, Wenqian; Huard, Zachary; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hutchcroft, David; Ibis, Philipp; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kazeev, Nikita; Kecke, Matthieu; Keizer, Floris; Kelsey, Matthew; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Klimkovich, Tatsiana; Koliiev, Serhii; Kolpin, Michael; Kopecna, Renata; Koppenburg, Patrick; Kosmyntseva, Alena; Kotriakhova, Sofia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreps, Michal; Kress, Felix Johannes; Krokovny, Pavel; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Pei-Rong; Li, Tenglin; Li, Yiming; Li, Zhuoming; Liang, Xixin; Likhomanenko, Tatiana; Lindner, Rolf; Lionetto, Federica; Lisovskyi, Vitalii; Liu, Xuesong; Loh, David; Loi, Angelo; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Macko, Vladimir; Mackowiak, Patrick; Maddrell-Mander, Samuel; Maev, Oleg; Maguire, Kevin; Maisuzenko, Dmitrii; Majewski, Maciej Witold; Malde, Sneha; Malecki, Bartosz; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Marangotto, Daniele; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marinangeli, Matthieu; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurice, Emilie; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McNab, Andrew; McNulty, Ronan; Mead, James Vincent; Meadows, Brian; Meaux, Cedric; Meier, Frank; Meinert, Nis; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Millard, Edward James; Minard, Marie-Noelle; Minzoni, Luca; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Mombächer, Titus; Monroy, Igancio Alberto; Monteil, Stephane; Morandin, Mauro; Morello, Michael Joseph; Morgunova, Olga; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Thi Dung; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Nogay, Alla; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Ossowska, Anna; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palutan, Matteo; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Mitesh; Patrignani, Claudia; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Pereima, Dmitrii; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pietrzyk, Guillaume; Pikies, Malgorzata; Pinci, Davide; Pisani, Flavio; Pistone, Alessandro; Piucci, Alessio; Placinta, Vlad-Mihai; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poli Lener, Marco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Ponce, Sebastien; Popov, Alexander; Popov, Dmitry; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Prisciandaro, Jessica; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Pullen, Hannah Louise; Punzi, Giovanni; Qian, Wenbin; Qin, Jia-Jia; Quagliani, Renato; Quintana, Boris; Rachwal, Bartlomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Ratnikov, Fedor; Raven, Gerhard; Ravonel Salzgeber, Melody; Reboud, Meril; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Robbe, Patrick; Robert, Arnaud; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rogozhnikov, Alexey; Roiser, Stefan; Rollings, Alexandra Paige; Romanovskiy, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Ruiz Vidal, Joan; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarpis, Gediminas; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schreiner, HF; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepulveda, Eduardo Enrique; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Soares Lavra, Lais; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavomira; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stepanova, Margarita; Stevens, Holger; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Stramaglia, Maria Elena; Straticiuc, Mihai; Straumann, Ulrich; Sun, Jiayin; Sun, Liang; Swientek, Krzysztof; Syropoulos, Vasileios; Szumlak, Tomasz; Szymanski, Maciej Pawel; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Tourinho Jadallah Aoude, Rafael; Tournefier, Edwige; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Usachov, Andrii; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagner, Alexander; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Verlage, Tobias Anton; Vernet, Maxime; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Vieira, Daniel; Vieites Diaz, Maria; Viemann, Harald; Vilasis-Cardona, Xavier; Vitti, Marcela; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Walsh, John; Wang, Jianchun; Wang, Yilong; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Weisser, Constantin; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Winn, Michael Andreas; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wyllie, Kenneth; Xie, Yuehong; Xu, Menglin; Xu, Qingnian; Xu, Zehua; Xu, Zhirui; Yang, Zhenwei; Yang, Zishuo; Yao, Yuezhe; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zheng, Yangheng; Zhu, Xianglei; Zhukov, Valery; Zonneveld, Jennifer Brigitta; Zucchelli, Stefano

    2018-02-17

    Investigations of the existence of pentaquark states containing a single $b$ (anti)quark decaying weakly into four specific final states $J/\\psi K^+\\pi^- p$, $J/\\psi K^- \\pi^- p$, $J/\\psi K^- \\pi^+ p$, and $J/\\psi \\phi (1020) p$ are reported. The data sample corresponds to an integrated luminosity of 3.0 fb$^{-1}$ in 7 and 8 TeV $pp$ collisions acquired with the LHCb detector. Signals are not observed and upper limits are set on the product of the production cross section times branching fraction with respect to that of the $\\Lambda^0_b$.

  12. The Problem of Weak Governments and Weak Societies in Eastern Europe

    Directory of Open Access Journals (Sweden)

    Marko Grdešić

    2008-01-01

    Full Text Available This paper argues that, for Eastern Europe, the simultaneous presence of weak governments and weak societies is a crucial obstacle which must be faced by analysts and reformers. The understanding of other normatively significant processes will be deficient without a consciousness-raising deliberation on this problem and its implications. This paper seeks to articulate the “relational” approach to state and society. In addition, the paper lays out a typology of possible patterns of relationship between state and society, dependent on whether the state is weak or strong and whether society is weak or strong. Comparative data are presented in order to provide an empirical support for the theses. Finally, the paper outlines two reform approaches which could enable breaking the vicious circle emerging in the context of weak governments and weak societies.

  13. Geometric phase topology in weak measurement

    Science.gov (United States)

    Samlan, C. T.; Viswanathan, Nirmal K.

    2017-12-01

    The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1–64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a pre-selected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (η) or ellipse orientation (χ) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the η spread in the complementary χ basis results in the appearance of a geometric phase with helical phase topology in the η ‑ χ parameter space. By representing the weak measurement on the Poincaré sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques’ capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.

  14. Weak KAM theory for a weakly coupled system of Hamilton–Jacobi equations

    KAUST Repository

    Figalli, Alessio

    2016-06-23

    Here, we extend the weak KAM and Aubry–Mather theories to optimal switching problems. We consider three issues: the analysis of the calculus of variations problem, the study of a generalized weak KAM theorem for solutions of weakly coupled systems of Hamilton–Jacobi equations, and the long-time behavior of time-dependent systems. We prove the existence and regularity of action minimizers, obtain necessary conditions for minimality, extend Fathi’s weak KAM theorem, and describe the asymptotic limit of the generalized Lax–Oleinik semigroup. © 2016, Springer-Verlag Berlin Heidelberg.

  15. Analyses and testing of model prestressed concrete reactor vessels with built-in planes of weakness

    International Nuclear Information System (INIS)

    Dawson, P.; Paton, A.A.; Fleischer, C.C.

    1990-01-01

    This paper describes the design, construction, analyses and testing of two small scale, single cavity prestressed concrete reactor vessel models, one without planes of weakness and one with planes of weakness immediately behind the cavity liner. This work was carried out to extend a previous study which had suggested the likely feasibility of constructing regions of prestressed concrete reactor vessels and biological shields, which become activated, using easily removable blocks, separated by a suitable membrane. The paper describes the results obtained and concludes that the planes of weakness concept could offer a means of facilitating the dismantling of activated regions of prestressed concrete reactor vessels, biological shields and similar types of structure. (author)

  16. Weakly supervised classification in high energy physics

    Science.gov (United States)

    Dery, Lucio Mwinmaarong; Nachman, Benjamin; Rubbo, Francesco; Schwartzman, Ariel

    2017-05-01

    As machine learning algorithms become increasingly sophisticated to exploit subtle features of the data, they often become more dependent on simulations. This paper presents a new approach called weakly supervised classification in which class proportions are the only input into the machine learning algorithm. Using one of the most challenging binary classification tasks in high energy physics — quark versus gluon tagging — we show that weakly supervised classification can match the performance of fully supervised algorithms. Furthermore, by design, the new algorithm is insensitive to any mis-modeling of discriminating features in the data by the simulation. Weakly supervised classification is a general procedure that can be applied to a wide variety of learning problems to boost performance and robustness when detailed simulations are not reliable or not available.

  17. Weak measurements in non-Hermitian systems

    Science.gov (United States)

    Matzkin, A.

    2012-11-01

    Weak measurements’—involving a weak unitary interaction between a quantum system and a meter followed by a projective measurement—are investigated when the system has a non-Hermitian Hamiltonian. We show in particular how the standard definition of the ‘weak value’ of an observable must be modified. These studies are undertaken in the context of bound-state scattering theory, a non-Hermitian formalism for which the involved Hilbert spaces are unambiguously defined and the metric operators can be explicitly computed. Numerical examples are given for a model system. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Quantum physics with non-Hermitian operators’.

  18. Weak antilocalization of composite fermions in graphene

    Science.gov (United States)

    Laitinen, Antti; Kumar, Manohar; Hakonen, Pertti J.

    2018-02-01

    We demonstrate experimentally that composite fermions in monolayer graphene display weak antilocalization. Our experiments deal with fractional quantum Hall (FQH) states in high-mobility, suspended graphene Corbino disks in the vicinity of ν =1 /2 . We find a strong temperature dependence of conductivity σ away from half filling, which is consistent with the expected electron-electron interaction-induced gaps in the FQH state. At half filling, however, the temperature dependence of conductivity σ (T ) becomes quite weak, as anticipated for a Fermi sea of composite fermions, and we find a logarithmic dependence of σ on T . The sign of this quantum correction coincides with the weak antilocalization of graphene composite fermions, indigenous to chiral Dirac particles.

  19. Weak layer fracture: facets and depth hoar

    Directory of Open Access Journals (Sweden)

    I. Reiweger

    2013-09-01

    Full Text Available Understanding failure initiation within weak snow layers is essential for modeling and predicting dry-snow slab avalanches. We therefore performed laboratory experiments with snow samples containing a weak layer consisting of either faceted crystals or depth hoar. During these experiments the samples were loaded with different loading rates and at various tilt angles until fracture. The strength of the samples decreased with increasing loading rate and increasing tilt angle. Additionally, we took pictures of the side of four samples with a high-speed video camera and calculated the displacement using a particle image velocimetry (PIV algorithm. The fracture process within the weak layer could thus be observed in detail. Catastrophic failure started due to a shear fracture just above the interface between the depth hoar layer and the underlying crust.

  20. Weak self-adjoint differential equations

    International Nuclear Information System (INIS)

    Gandarias, M L

    2011-01-01

    The concepts of self-adjoint and quasi self-adjoint equations were introduced by Ibragimov (2006 J. Math. Anal. Appl. 318 742-57; 2007 Arch. ALGA 4 55-60). In Ibragimov (2007 J. Math. Anal. Appl. 333 311-28), a general theorem on conservation laws was proved. In this paper, we generalize the concept of self-adjoint and quasi self-adjoint equations by introducing the definition of weak self-adjoint equations. We find a class of weak self-adjoint quasi-linear parabolic equations. The property of a differential equation to be weak self-adjoint is important for constructing conservation laws associated with symmetries of the differential equation. (fast track communication)

  1. Extrapolating Weak Selection in Evolutionary Games

    Science.gov (United States)

    Wu, Bin; García, Julián; Hauert, Christoph; Traulsen, Arne

    2013-01-01

    In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By “qualitatively valid” we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more) strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies . In particular, rank changes are almost certain for , which jeopardizes the predictive power of results derived for weak selection. PMID:24339769

  2. Weak Acid Ionization Constants and the Determination of Weak Acid-Weak Base Reaction Equilibrium Constants in the General Chemistry Laboratory

    Science.gov (United States)

    Nyasulu, Frazier; McMills, Lauren; Barlag, Rebecca

    2013-01-01

    A laboratory to determine the equilibrium constants of weak acid negative weak base reactions is described. The equilibrium constants of component reactions when multiplied together equal the numerical value of the equilibrium constant of the summative reaction. The component reactions are weak acid ionization reactions, weak base hydrolysis…

  3. Weak interactions of the b quark

    International Nuclear Information System (INIS)

    Branco, G.C.; Mohapatra, R.N.

    1978-01-01

    In weak-interaction models with two charged W bosons of comparable mass, there exists a novel possibility for the weak interactions of the b quark, in which the (u-barb)/sub R/ current occurs with maximal strength. It is noted that multimuon production in e + e - annihilation at above Q 2 > or approx. = (12 GeV) 2 will distinguish this scheme from the conventional one. We also present a Higgs system that leads naturally to this type of coupling, in a class of gauge models

  4. Gravitational Wave Detection via Weak Measurements Amplification

    OpenAIRE

    Hu, Meng-Jun; Zhang, Yong-Sheng

    2017-01-01

    A universal amplification scheme of ultra-small phase based on weak measurements is given and a weak measurements amplification based laser interferometer gravitational-wave observatory (WMA-LIGO) is suggested. The WMA-LIGO has potential to amplify the ultra-small phase signal to at least $10^{3}$ order of magnitude such that the sensitivity and bandwidth of gravitational-wave detector can be further improved. Our results not only shed a new light on the quantum measurement but also open a ne...

  5. Weak form factors of beauty baryons

    International Nuclear Information System (INIS)

    Ivanov, M.A.; Lyubovitskij, V.E.

    1992-01-01

    Full analysis of semileptonic decays of beauty baryons with J p =1/2 2 and J p =3/2 2 into charmed ones within the Quark Confinement Model is reported. Weak form factors and decay rates are calculated. Also the heavy quark limit m Q →∞ (Isgur-Wise symmetry) is examined. The weak heavy-baryon form factors in the Isgur-Wise limit and 1/m Q -corrections to them are computered. The Ademollo-Gatto theorem is spin-flavour symmetry of heavy quarks is checked. 33 refs.; 1 fig.; 9 tabs

  6. Weak interactions at high energies. [Lectures, review

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.

    1978-08-01

    Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references. (JFP)

  7. Fast measure proceeding of weak currents

    International Nuclear Information System (INIS)

    Taieb, J.

    1953-01-01

    The process of fast measure of the weak currents that we are going to describe briefly apply worthy of the provided currents by the sources to elevated value internal resistance, as it is the case for the ionization chamber, the photocells, mass spectroscopic tubes. The problem to measure weak currents is essentially a problem of amplifier and of input circuit. We intended to achieve a whole amplifier and input circuit with advanced performances, meaning that for a measured celerity we wanted to have an signal/noise ratio the most important as in the classic systems and for a same report signal/noise a more quickly done measure. (M.B.) [fr

  8. From Suitable Weak Solutions to Entropy Viscosity

    KAUST Repository

    Guermond, Jean-Luc

    2010-12-16

    This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i) to recall basic mathematical properties of the three-dimensional incompressible Navier-Stokes equations and to show how they might relate to LES (ii) to introduce an entropy viscosity technique based on the notion of suitable weak solution and to illustrate numerically this concept. © 2010 Springer Science+Business Media, LLC.

  9. Fixation times in evolutionary games under weak selection

    International Nuclear Information System (INIS)

    Altrock, Philipp M; Traulsen, Arne

    2009-01-01

    In evolutionary game dynamics, reproductive success increases with the performance in an evolutionary game. If strategy A performs better than strategy B, strategy A will spread in the population. Under stochastic dynamics, a single mutant will sooner or later take over the entire population or go extinct. We analyze the mean exit times (or average fixation times) associated with this process. We show analytically that these times depend on the payoff matrix of the game in an amazingly simple way under weak selection, i.e. strong stochasticity: the payoff difference Δπ is a linear function of the number of A individuals i, Δπ=u i+v. The unconditional mean exit time depends only on the constant term v. Given that a single A mutant takes over the population, the corresponding conditional mean exit time depends only on the density dependent term u. We demonstrate this finding for two commonly applied microscopic evolutionary processes.

  10. Identification of Differentially Methylated Sites with Weak Methylation Effects

    Directory of Open Access Journals (Sweden)

    Hong Tran

    2018-02-01

    Full Text Available Deoxyribonucleic acid (DNA methylation is an epigenetic alteration crucial for regulating stress responses. Identifying large-scale DNA methylation at single nucleotide resolution is made possible by whole genome bisulfite sequencing. An essential task following the generation of bisulfite sequencing data is to detect differentially methylated cytosines (DMCs among treatments. Most statistical methods for DMC detection do not consider the dependency of methylation patterns across the genome, thus possibly inflating type I error. Furthermore, small sample sizes and weak methylation effects among different phenotype categories make it difficult for these statistical methods to accurately detect DMCs. To address these issues, the wavelet-based functional mixed model (WFMM was introduced to detect DMCs. To further examine the performance of WFMM in detecting weak differential methylation events, we used both simulated and empirical data and compare WFMM performance to a popular DMC detection tool methylKit. Analyses of simulated data that replicated the effects of the herbicide glyphosate on DNA methylation in Arabidopsis thaliana show that WFMM results in higher sensitivity and specificity in detecting DMCs compared to methylKit, especially when the methylation differences among phenotype groups are small. Moreover, the performance of WFMM is robust with respect to small sample sizes, making it particularly attractive considering the current high costs of bisulfite sequencing. Analysis of empirical Arabidopsis thaliana data under varying glyphosate dosages, and the analysis of monozygotic (MZ twins who have different pain sensitivities—both datasets have weak methylation effects of <1%—show that WFMM can identify more relevant DMCs related to the phenotype of interest than methylKit. Differentially methylated regions (DMRs are genomic regions with different DNA methylation status across biological samples. DMRs and DMCs are essentially the same

  11. Weak universality in inhomogeneous Ising quantum chains

    International Nuclear Information System (INIS)

    Karevski, Dragi

    2006-01-01

    The Ising quantum chain with arbitrary coupling distribution {λ i } leading to an anisotropic scaling is considered. The smallest gap of the chain is connected to the surface magnetization by the relation Λ 1 = m s ({λ i })m s ({λ -1 i }). For some aperiodic distribution {λ i }, a weak universality of the critical behaviour is found. (letter to the editor)

  12. Neutrino propagation in a weakly magnetized medium

    Indian Academy of Sciences (India)

    The organization of the paper is as follows: In §2 we discuss the basics of neutrino–photon effective action and the fermion propagators in a magnetized medium. Section 3 contains the details of the calculation of the one-loop diagram and in §4 we consider the weak-field limit. Finally, we conclude with a discussion.

  13. Fermi and the Theory of Weak Interactions

    Indian Academy of Sciences (India)

    IAS Admin

    Can the laws of physics distinguish between the two coordinate systems? Except for the weak interaction, all other laws of physics are symmetric under mirror reflection and hence cannot be used to distinguish between the left and right coordinate systems. The significance of this left{right symmetry, as well as its violation ...

  14. QCD anomalies in hadronic weak decays

    International Nuclear Information System (INIS)

    Gerard, J.-M.; Trine, S.

    2004-01-01

    We consider the flavor-changing operators associated with the strong axial and trace anomalies. Their short-distance generation through penguinlike diagrams is obtained within the QCD external field formalism. Standard-model operator evolution exhibits a suppression of anomalous effects in K and B hadronic weak decays. A genuine set of dimension-eight ΔS=1 operators is also displayed

  15. Weak interaction matrix elements with staggered fermions

    International Nuclear Information System (INIS)

    Sharpe, S.R.

    1986-08-01

    An overview of the results of the Los Alamos Advanced Computing Group is given. The theory behind the measurement of Weak Interaction Matrix Elements using staggered fermions is presented, and contrasted with that for Wilson fermions. This is followed by a preliminary discussion of numerical results on a 12 3 x 30 lattice. 10 refs., 4 figs

  16. Frequency dependence of magnetic susceptibility of weakly ...

    African Journals Online (AJOL)

    This paper reports the frequency dependence of magnetic susceptibility of weakly contaminated soil sediments. Low field magnetic susceptibility measurements were carried out on soil sediments at Bomo irrigation dam, Samaru College of Agriculture, Ahmadu Bello University, (ABU), Zaria, using the MS2D field loop.

  17. Common fixed points for weakly compatible maps

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    Indian Acad. Sci. (Math. Sci.), Vol. 111, No. 2, May 2001, pp. 241–247. Printed in India. Common fixed points for weakly compatible maps. RENU CHUGH and SANJAY KUMAR. Department of Mathematics, Maharshi Dayanand University, Rohtak 124 001, India. MS received 31 January 2000; revised 11 December 2000.

  18. Fermi and the Theory of Weak Interactions

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 1. Fermi and the Theory of Weak Interactions. G Rajasekaran. General Article Volume 19 Issue 1 January 2014 pp 18-44. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/019/01/0018-0044 ...

  19. Efficient bootstrap with weakly dependent processes

    NARCIS (Netherlands)

    Bravo, Francesco; Crudu, Federico

    2012-01-01

    The efficient bootstrap methodology is developed for overidentified moment conditions models with weakly dependent observation. The resulting bootstrap procedure is shown to be asymptotically valid and can be used to approximate the distributions of t-statistics, the J-statistic for overidentifying

  20. Thermorheological effect on magnetoconvection in weak electrically ...

    Indian Academy of Sciences (India)

    maintained at constant temperatures T0 and T1 (with T0 > T1) respectively. In addition to a temperature gradient, a vertical magnetic field is also imposed across the layer (see figure 1). The system of equations of hydromagnetics describing the Rayleigh-Benard sit- uation in a weak electrically conducting liquid is the ...

  1. Weak NNM couplings and nuclear parity violation

    International Nuclear Information System (INIS)

    Holstein, B.R.

    1987-01-01

    After many years of careful theoretical and experimental study of nuclear parity violation, rough empirical values for weak parity violation nucleon-nucleon-meson vertices have been deduced. We address some of the physics which has been learned from this effort and show that it has implications for work going on outside this field. (author)

  2. Fermi and the Theory of Weak Interactions

    Indian Academy of Sciences (India)

    IAS Admin

    The history of weak interactions starting with. Fermi's creation of the beta decay theory and culminating in its modern avatar in the form of the electroweak gauge theory is described. Dis- coveries of parity violation, matter{antimatter asymmetry, W and Z bosons and neutrino mass are highlighted. Introduction. Sun gives us ...

  3. Broken color symmetry and weak currents

    International Nuclear Information System (INIS)

    Stech, B.

    1976-01-01

    Broken colour symmetry predicts a very rich spectrum of new particles. If broken colour is relevant at all, charged psi-particles should be found in particular at the 4 GeV region. For the weak hadronic currents no completely satisfactory suggestion exists. Broken colour symmetry describes qualitatively several of the new effects observed recently. (BJ) [de

  4. Modelling, Measuring and Compensating Color Weak Vision.

    Science.gov (United States)

    Oshima, Satoshi; Mochizuki, Rika; Lenz, Reiner; Chao, Jinhui

    2016-03-08

    We use methods from Riemann geometry to investigate transformations between the color spaces of color-normal and color weak observers. The two main applications are the simulation of the perception of a color weak observer for a color normal observer and the compensation of color images in a way that a color weak observer has approximately the same perception as a color normal observer. The metrics in the color spaces of interest are characterized with the help of ellipsoids defined by the just-noticable-differences between color which are measured with the help of color-matching experiments. The constructed mappings are isometries of Riemann spaces that preserve the perceived color-differences for both observers. Among the two approaches to build such an isometry, we introduce normal coordinates in Riemann spaces as a tool to construct a global color-weak compensation map. Compared to previously used methods this method is free from approximation errors due to local linearizations and it avoids the problem of shifting locations of the origin of the local coordinate system. We analyse the variations of the Riemann metrics for different observers obtained from new color matching experiments and describe three variations of the basic method. The performance of the methods is evaluated with the help of semantic differential (SD) tests.

  5. Studying dark matter haloes with weak lensing

    NARCIS (Netherlands)

    Velander, Malin Barbro Margareta

    2012-01-01

    Our Universe is comprised not only of normal matter but also of unknown components: dark matter and dark energy. This Thesis recounts studies of dark matter haloes, using a technique known as weak gravitational lensing, in order to learn more about the nature of these dark components. The haloes

  6. Weak organic acid stress in Bacillus subtilis

    NARCIS (Netherlands)

    ter Beek, A.S.

    2009-01-01

    Weak organic acids are commonly used food preservatives that protect food products from bacterial contamination. A variety of spore-forming bacterial species pose a serious problem to the food industry by causing extensive food spoilage or even food poisoning. Understanding the mechanisms of

  7. Legitimacy Building under Weak Institutional Settings

    DEFF Research Database (Denmark)

    Wejs, Anja; Harvold, Kjell; Larsen, Sanne Vammen

    2014-01-01

    Local strategies for adaptation to climate change in Denmark and Norway are discussed. In both countries, the national impetus for local adaptation is weak; it is largely left to local actors to take the initiative. The dynamics of the different approaches to climate-change adaptation at the loca...

  8. Completely continuous and weakly completely continuous abstract ...

    Indian Academy of Sciences (India)

    approximate identity for B, bounded in A. In addition, a necessary condition for the weak complete continuity of A is ... continuous elements of a Banach algebra A and symmetric abstract Segal algebras B with respect to A, in the case ..... [13] Hewitt E and Ross K A, Abstract harmonic analysis, 2nd edn. I, II (1970) (New York,.

  9. Weak and strong nonlinearities in magnetic bearings

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav

    2004-01-01

    Roč. 39, č. 7 (2004), s. 779-795 ISSN 0094-114X R&D Projects: GA ČR GA101/00/1471; GA AV ČR IBS2076301 Institutional research plan: CEZ:AV0Z2076919 Keywords : weak nonlinearitiy * strong nonlinearity * magnetics bearings Subject RIV: BI - Acoustics Impact factor: 0.605, year: 2004

  10. Theory of weak and electromagnetic interactions

    International Nuclear Information System (INIS)

    Weinberg, S.

    1973-01-01

    The problem discussed is how to construct field theories of the weak interaction which make sense and in particular how to construct field theories in which divergences either do not appear at all or can be eliminated in a physically reasonable way. (U.S.)

  11. Nonstationary weak signal detection based on normalization ...

    Indian Academy of Sciences (India)

    Haibin Zhang

    Time-varying signal; weak signal detection; varying parameters; stochastic resonance. 1. Introduction. In general view, noise ..... the numerical solution for the typical first-order differential equation as Eq. (2). The discrete fourth-rank Runge–Kutta method [27] as follows is applied to solve the equation numerically. x. 0 ¼ dx dt.

  12. Thermorheological effect on magnetoconvection in weak electrically ...

    Indian Academy of Sciences (India)

    Thermorheological effect on magnetoconvection. Before we embark on a discussion of the results obtained in the study, we present below the values of various physical quantities with respect to Mazola corn oil, which is a weak electrically conducting liquid (WECL) [13-15]: σ(T) = [0.21 + 0.03(T -10°)] x10-. 10 mho/m,.

  13. Axion monodromy and the weak gravity conjecture

    International Nuclear Information System (INIS)

    Hebecker, Arthur; Rompineve, Fabrizio; Westphal, Alexander

    2015-12-01

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the 'relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: While the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, Λ 3 ∝mfM pl , independent of the height of these 'wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a 'geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. Imposing this 'geometric conjecture', e.g. on the basis of the more widely accepted weak gravity conjecture for particles, provides at least some support for the (electric and magnetic) conjecture for domain walls.

  14. Gauge theories of the weak interactions

    International Nuclear Information System (INIS)

    Quinn, H.

    1978-08-01

    Two lectures are presented on the Weinberg--Salam--Glashow--Iliopoulos--Maiani gauge theory for weak interactions. An attempt is made to give some impressions of the generality of this model, how it was developed, variations found in the literature, and the status of the standard model. 21 references

  15. Weak equivalence classes of complex vector bundles

    Czech Academy of Sciences Publication Activity Database

    Le, Hong-Van

    LXXVII, č. 1 (2008), s. 23-30 ISSN 0862-9544 R&D Projects: GA AV ČR IAA100190701 Institutional research plan: CEZ:AV0Z10190503 Keywords : chern classes * complex Grassmannians weak equivalence Subject RIV: BA - General Mathematics

  16. The strengths, weaknesses, opportunities, and threats (SWOTs ...

    African Journals Online (AJOL)

    The objective of this review was to adopt the SWOT concept to elucidate the biological Strengths, Weaknesses, Opportunities, and Threats to Ebola virus as a pathogen, with a view to understanding and devising holistic strategies at combating and overcoming the scourge of EVD. Method: This systematic review and ...

  17. New weak keys in simplified IDEA

    Science.gov (United States)

    Hafman, Sari Agustini; Muhafidzah, Arini

    2016-02-01

    Simplified IDEA (S-IDEA) is simplified version of International Data Encryption Algorithm (IDEA) and useful teaching tool to help students to understand IDEA. In 2012, Muryanto and Hafman have found a weak key class in the S-IDEA by used differential characteristics in one-round (0, ν, 0, ν) → (0,0, ν, ν) on the first round to produce input difference (0,0, ν, ν) on the fifth round. Because Muryanto and Hafman only use three differential characteristics in one-round, we conducted a research to find new differential characteristics in one-round and used it to produce new weak key classes of S-IDEA. To find new differential characteristics in one-round of S-IDEA, we applied a multiplication mod 216+1 on input difference and combination of active sub key Z1, Z4, Z5, Z6. New classes of weak keys are obtained by combining all of these characteristics and use them to construct two new differential characteristics in full-round of S-IDEA with or without the 4th round sub key. In this research, we found six new differential characteristics in one round and combined them to construct two new differential characteristics in full-round of S-IDEA. When two new differential characteristics in full-round of S-IDEA are used and the 4th round sub key required, we obtain 2 new classes of weak keys, 213 and 28. When two new differential characteristics in full-round of S-IDEA are used, yet the 4th round sub key is not required, the weak key class of 213 will be 221 and 28 will be 210. Membership test can not be applied to recover the key bits in those weak key classes. The recovery of those unknown key bits can only be done by using brute force attack. The simulation result indicates that the bit of the key can be recovered by the longest computation time of 0,031 ms.

  18. Weak mixing below the weak scale in dark-matter direct detection

    Science.gov (United States)

    Brod, Joachim; Grinstein, Benjamin; Stamou, Emmanuel; Zupan, Jure

    2018-02-01

    If dark matter couples predominantly to the axial-vector currents with heavy quarks, the leading contribution to dark-matter scattering on nuclei is either due to one-loop weak corrections or due to the heavy-quark axial charges of the nucleons. We calculate the effects of Higgs and weak gauge-boson exchanges for dark matter coupling to heavy-quark axial-vector currents in an effective theory below the weak scale. By explicit computation, we show that the leading-logarithmic QCD corrections are important, and thus resum them to all orders using the renormalization group.

  19. Towards weakly constrained double field theory

    Directory of Open Access Journals (Sweden)

    Kanghoon Lee

    2016-08-01

    Full Text Available We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  20. The Weak Gravity Conjecture in three dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Montero, Miguel [Departamento de Física Teórica, Facultad de Ciencias,Universidad Autónoma de Madrid,Calle Francisco Tomás y Valiente 7, 28049 Madrid (Spain); Instituto de Física Teórica IFT-UAM/CSIC, Campus de Cantoblanco,C/ Nicolás Cabrera 13-15, 28049 Madrid (Spain); Shiu, Gary; Soler, Pablo [Department of Physics, University of Wisconsin-Madison,1150 University Ave, Madison, WI 53706 (United States); Department of Physics & Institute for Advanced Study,Hong Kong University of Science and Technology,Lo Ka Chung Building, Lee Shau Kee Campus, Clear Water Bay (Hong Kong)

    2016-10-28

    We study weakly coupled U(1) theories in AdS{sub 3}, their associated charged BTZ solutions, and their charged spectra. We find that modular invariance of the holographic dual two-dimensional CFT and compactness of the gauge group together imply the existence of charged operators with conformal dimension significantly below the black hole threshold. We regard this as a form of the Weak Gravity Conjecture (WGC) in three dimensions. We also explore the constraints posed by modular invariance on a particular discrete ℤ{sub N} symmetry which arises in our discussion. In this case, modular invariance does not guarantee the existence of light ℤ{sub N}-charged states. We also highlight the differences between our discussion and the usual heuristic arguments for the WGC based on black hole remnants.

  1. Weak cosmic censorship: as strong as ever.

    Science.gov (United States)

    Hod, Shahar

    2008-03-28

    Spacetime singularities that arise in gravitational collapse are always hidden inside of black holes. This is the essence of the weak cosmic censorship conjecture. The hypothesis, put forward by Penrose 40 years ago, is still one of the most important open questions in general relativity. In this Letter, we reanalyze extreme situations which have been considered as counterexamples to the weak cosmic censorship conjecture. In particular, we consider the absorption of scalar particles with large angular momentum by a black hole. Ignoring back reaction effects may lead one to conclude that the incident wave may overspin the black hole, thereby exposing its inner singularity to distant observers. However, we show that when back reaction effects are properly taken into account, the stability of the black-hole event horizon is irrefutable. We therefore conclude that cosmic censorship is actually respected in this type of gedanken experiments.

  2. A dynamical weak scale from inflation

    Energy Technology Data Exchange (ETDEWEB)

    You, Tevong, E-mail: tty20@cam.ac.uk [DAMTP, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2017-09-01

    Dynamical scanning of the Higgs mass by an axion-like particle during inflation may provide a cosmological component to explaining part of the hierarchy problem. We propose a novel interplay of this cosmological relaxation mechanism with inflation, whereby the backreaction of the Higgs vacuum expectation value near the weak scale causes inflation to end. As Hubble drops, the relaxion's dissipative friction increases relative to Hubble and slows it down enough to be trapped by the barriers of its periodic potential. Such a scenario raises the natural cut-off of the theory up to ∼ 10{sup 10} GeV, while maintaining a minimal relaxion sector without having to introduce additional scanning scalars or new physics coincidentally close to the weak scale.

  3. A proof of the weak gravity conjecture

    Science.gov (United States)

    Hod, Shahar

    The weak gravity conjecture suggests that, in a self-consistent theory of quantum gravity, the strength of gravity is bounded from above by the strengths of the various gauge forces in the theory. In particular, this intriguing conjecture asserts that in a theory describing a U(1) gauge field coupled consistently to gravity, there must exist a particle whose proper mass is bounded (in Planck units) by its charge: m/mP attracted the attention of physicists and mathematicians over the last decade. It should be emphasized, however, that despite the fact that there are numerous examples from field theory and string theory that support the conjecture, we still lack a general proof of its validity. In the present paper, we prove that the weak gravity conjecture (and, in particular, the mass-charge upper bound m/mP law of thermodynamics, a law which is widely believed to reflect a fundamental aspect of the elusive theory of quantum gravity.

  4. Asymptotic theory of weakly dependent random processes

    CERN Document Server

    Rio, Emmanuel

    2017-01-01

    Presenting tools to aid understanding of asymptotic theory and weakly dependent processes, this book is devoted to inequalities and limit theorems for sequences of random variables that are strongly mixing in the sense of Rosenblatt, or absolutely regular. The first chapter introduces covariance inequalities under strong mixing or absolute regularity. These covariance inequalities are applied in Chapters 2, 3 and 4 to moment inequalities, rates of convergence in the strong law, and central limit theorems. Chapter 5 concerns coupling. In Chapter 6 new deviation inequalities and new moment inequalities for partial sums via the coupling lemmas of Chapter 5 are derived and applied to the bounded law of the iterated logarithm. Chapters 7 and 8 deal with the theory of empirical processes under weak dependence. Lastly, Chapter 9 describes links between ergodicity, return times and rates of mixing in the case of irreducible Markov chains. Each chapter ends with a set of exercises. The book is an updated and extended ...

  5. Orbits in weak and strong bars

    CERN Document Server

    Contopoulos, George

    1980-01-01

    The authors study the plane orbits in simple bar models embedded in an axisymmetric background when the bar density is about 1% (weak), 10% (intermediate) or 100% (strong bar) of the axisymmetric density. Most orbits follow the stable periodic orbits. The basic families of periodic orbits are described. In weak bars with two Inner Lindblad Resonances there is a family of stable orbits extending from the center up to the Outer Lindblad Resonance. This family contains the long period orbits near corotation. Other stable families appear between the Inner Lindblad Resonances, outside the Outer Lindblad Resonance, around corotation (short period orbits) and around the center (retrograde). Some families become unstable or disappear in strong bars. A comparison is made with cases having one or no Inner Lindblad Resonance. (12 refs).

  6. SANS observations on weakly flocculated dispersions

    DEFF Research Database (Denmark)

    Mischenko, N.; Ourieva, G.; Mortensen, K.

    1997-01-01

    Structural changes occurring in colloidal dispersions of poly-(methyl metacrylate) (PMMA) particles, sterically stabilized with poly-(12-hydroxystearic acid) (PHSA), while varying the solvent quality, temperature and shear rate, are investigated by small-angle neutron scattering (SANS......). For a moderately concentrated dispersion in a marginal solvent the transition on cooling from the effective stability to a weak attraction is monitored, The degree of attraction is determined in the framework of the sticky spheres model (SSM), SANS and rheological results are correlated....

  7. Summary of the hadronic weak interaction session

    International Nuclear Information System (INIS)

    Bock, G.; Bryman, D.A.; Numao, T.

    1993-01-01

    The authors summarize and discuss present and future experiments on decays of light mesons and muons that were presented in the Hadronic Weak Interaction working group session of the open-quotes Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Facilities.close quotes Precise measurements and rare-decay searches, which sense mass scales in the 1-1000 TeV region, are discussed in the context of the standard model and beyond

  8. On weak compactness in L_1 spaces

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marián; Montesinos, V.; Zizler, Václav

    2009-01-01

    Roč. 39, č. 6 (2009), s. 1885-1893 ISSN 0035-7596 R&D Projects: GA AV ČR(CZ) IAA100190610; GA AV ČR IAA100190502; GA AV ČR IAA1019103 Institutional research plan: CEZ:AV0Z10190503 Keywords : weak compactness * subspace of L_1 * superreflexive space Subject RIV: BA - General Mathematics Impact factor: 0.260, year: 2009

  9. On weak solutions of stochastic differential equations

    Czech Academy of Sciences Publication Activity Database

    Hofmanová, Martina; Seidler, Jan

    2012-01-01

    Roč. 30, č. 1 (2012), s. 100-121 ISSN 0736-2994 R&D Projects: GA ČR GAP201/10/0752 Institutional research plan: CEZ:AV0Z10750506 Keywords : stochastic differential equations * weak solutions Subject RIV: BA - General Mathematics Impact factor: 0.303, year: 2012 http://library.utia.cas.cz/separaty/2012/SI/hofmanova-0373626.pdf

  10. An unusual cause of hypokalemic muscle weakness.

    Science.gov (United States)

    Valeriano, J; Tucker, P; Kattah, J

    1983-09-01

    A 36-year-old woman presented with proximal muscle weakness, cramps, and a serum potassium level of 2.7 mEq/l. During her hospitalization she was noted to use excessive quantities of a snuff preparation containing glycyrrhizinic acid, a potent mineralocorticoid analogue. With discontinuation of this substance, her potassium returned to normal values and her strength improved. This case is submitted as a hypokalemia myopathy induced by snuff dipping.

  11. Acute neuromuscular weakness associated with dengue infection

    Directory of Open Access Journals (Sweden)

    Harmanjit Singh Hira

    2012-01-01

    Full Text Available Background: Dengue infections may present with neurological complications. Whether these are due to neuromuscular disease or electrolyte imbalance is unclear. Materials and Methods: Eighty-eight patients of dengue fever required hospitalization during epidemic in year 2010. Twelve of them presented with acute neuromuscular weakness. We enrolled them for study. Diagnosis of dengue infection based on clinical profile of patients, positive serum IgM ELISA, NS1 antigen, and sero-typing. Complete hemogram, kidney and liver functions, serum electrolytes, and creatine phosphokinase (CPK were tested. In addition, two patients underwent nerve conduction velocity (NCV test and electromyography. Results: Twelve patients were included in the present study. Their age was between 18 and 34 years. Fever, myalgia, and motor weakness of limbs were most common presenting symptoms. Motor weakness developed on 2 nd to 4 th day of illness in 11 of 12 patients. In one patient, it developed on 10 th day of illness. Ten of 12 showed hypokalemia. One was of Guillain-Barré syndrome and other suffered from myositis; they underwent NCV and electromyography. Serum CPK and SGOT raised in 8 out of 12 patients. CPK of patient of myositis was 5098 IU. All of 12 patients had thrombocytopenia. WBC was in normal range. Dengue virus was isolated in three patients, and it was of serotype 1. CSF was normal in all. Within 24 hours, those with hypokalemia recovered by potassium correction. Conclusions: It was concluded that the dengue virus infection led to acute neuromuscular weakness because of hypokalemia, myositis, and Guillain-Barré syndrome. It was suggested to look for presence of hypokalemia in such patients.

  12. Weak interaction studies from nuclear beta decay

    International Nuclear Information System (INIS)

    Morita, M.

    1981-01-01

    The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os 189 was 1.4 x 10 - 7 in conformity with the experimental value 1.7 x 10 - 7 . The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1 + -- 0 + transition in oriented B 12 and N 12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)

  13. Synchronization of weakly coupled canard oscillators

    Science.gov (United States)

    Köksal Ersöz, Elif; Desroches, Mathieu; Krupa, Martin

    2017-06-01

    Synchronization has been studied extensively in the context of weakly coupled oscillators using the so-called phase response curve (PRC) which measures how a change of the phase of an oscillator is affected by a small perturbation. This approach was based upon the work of Malkin, and it has been extended to relaxation oscillators. Namely, synchronization conditions were established under the weak coupling assumption, leading to a criterion for the existence of synchronous solutions of weakly coupled relaxation oscillators. Previous analysis relies on the fact that the slow nullcline does not intersect the fast nullcline near one of its fold points, where canard solutions can arise. In the present study we use numerical continuation techniques to solve the adjoint equations and we show that synchronization properties of canard cycles are different than those of classical relaxation cycles. In particular, we highlight a new special role of the maximal canard in separating two distinct synchronization regimes: the Hopf regime and the relaxation regime. Phase plane analysis of slow-fast oscillators undergoing a canard explosion provides an explanation for this change of synchronization properties across the maximal canard.

  14. Development of continuous ADR system for weak gravity missions

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, T; Kamiya, K [Tsukuba Magnet Laboratory, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Shirron, P [NASA/Goddard Space Flight Center, Code 552 Greenbelt, MD 20771 (United States); Mitsuda, K [JAXA/ISAS, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan)], E-mail: Numazawa.takenori@nims.go.jp

    2009-02-01

    Adiabatic Demagnetization Refrigeration (ADR) does not use working fluids contrary to conventional refrigerators that make use of the fluid density difference, which leads to superiority of the ADR under the weak gravity condition. In this study, we developed a continuous ADR system to provide constant cooling temperatures {approx}0.1 K. The system consists of four stages of magnetic materials and magnets cascaded with heat switches. The magnetic materials CPA and GdLiF{sub 4} are used for 3 stages between 0.1K and 1.4 K, and single stage between 1.4 K and 4 K, respectively. Passive heat switches are used for the stages > 0.3 K and a superconducting heat switch is used for the continuous stage at {approx}0.1 K. A G-M cycle cooler with a 100 V compressor unit is used to cool the ADR and cryostat shieldings. Total mass of flight model is less than 60 kg. Cooling tests with Transition Edge Sensor on the ground showed that the ADR provided continuous cooling temperatures between 105 mK and 120 mK and it successfully operated the TES. Airborne flight experiments confirmed the ability of the cooling system under the mili-gravity condition. The experimental results showed that the ADR could provide stable temperature under the weak gravity, however, strong vibrations coming from turbulence or takeoff affected to the stability of ADR cycle.

  15. Photon trajectories, anomalous velocities and weak measurements: a classical interpretation

    International Nuclear Information System (INIS)

    Bliokh, Konstantin Y; Kofman, Abraham G; Nori, Franco; Bekshaev, Aleksandr Y

    2013-01-01

    Recently, Kocsis et al (2011 Science 332 1170) reported the observation of ‘average trajectories of single photons’ in a two-slit interference experiment. This was possible by using the quantum weak-measurement method, which implies averaging over many events, i.e. in fact, a multi-photon limit of classical linear optics. We give a classical-optics interpretation of this experiment and other related problems. It appears that weak measurements of the local momentum of photons made by Kocsis et al represent measurements of the Poynting vector in an optical field. We consider both the real and imaginary parts of the local momentum and show that their measurements have been realized in classical optics using small-probe particles. We also examine the appearance of ‘anomalous’ values of the local momentum: either negative (backflow) or exceeding the wavenumber (superluminal propagation). These features appear to be closely related to vortices and evanescent waves. Finally, we revisit a number of older works and find examples of photon trajectories and anomalous-momentum measurements in various optical experiments. (paper)

  16. Dephasing in coherent communication with weak signal states

    International Nuclear Information System (INIS)

    Jarzyna, Marcin; Banaszek, Konrad; Demkowicz-Dobrzański, Rafał

    2014-01-01

    We analyse the ultimate quantum limit on the accessible information for an optical communication scheme when time bins carry coherent light pulses prepared in one of several orthogonal modes and the phase undergoes diffusion after each channel use. This scheme, an example of a quantum memory channel, can be viewed as noisy pulse position modulation (PPM) keying with phase fluctuations occurring between consecutive PPM symbols. We derive a general expression for the output states in the Fock basis and implement a numerical procedure to calculate the Holevo quantity. Using asymptotic properties of Toeplitz matrices, we also present an analytic expression for the Holevo quantity valid for very weak signals and sufficiently strong dephasing when the dominant contribution comes from the single-photon sector in the Hilbert space of signal states. Based on numerical results we conjecture an inequality for contributions to the Holevo quantity from multiphoton sectors which implies that in the asymptotic limit of weak signals, for arbitrarily small dephasing the accessible information scales linearly with the average number of photons contained in the pulse. Such behaviour presents a qualitative departure from the fully coherent case. (paper)

  17. Systematic review: role of acid, weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease

    NARCIS (Netherlands)

    Boeckxstaens, G. E.; Smout, A.

    2010-01-01

    The importance of weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease (GERD) is gaining recognition. To quantify the proportions of reflux episodes that are acidic (pH <4), weakly acidic (pH 4-7) and weakly alkaline (pH >7) in adult patients with GERD, and to evaluate their

  18. Axial weak currents in the Wess-Zumino term

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo

    1986-01-01

    In a simplified model lagrangian of 3 quarks with an SU(2)sub(L) gauging of chiral SU(3)sub(L)xSU(3)sub(R) to introduce W-boson, we analyse certain complications associated with the low-energy theorem including axial weak fields. We first show that the low-energy amplitude is independent of the form of the quark-level anomalous identity, whether in the covariant form or the consistent form. However, the interplay of the short-distance dynamics (anomalous identity) and the long-distance dynamics (low-energy theorem) becomes involved in the presence of axial fields. We then discuss what kinds of conditions single out the gauged Wess-Zumino term as a low-energy effective action. The connection of the low-energy theorem with the 't Hooft anomaly matching condition is also discussed. (orig.)

  19. Critical points in the Bragg glass phase of a weakly pinned crystal of ...

    Indian Academy of Sciences (India)

    New experimental data are presented on the scan rate dependence of the magnetization hysteresis width () (∝ critical current density c()) in isothermal - scans in a weakly pinned single crystal of Ca3Rh4Sn13, which displays second magnetization peak (SMP) anomaly as distinct from the peak effect (PE).

  20. The magnetosphere under weak solar wind forcing

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2007-02-01

    Full Text Available The Earth's magnetosphere was very strongly disturbed during the passage of the strong shock and the following interacting ejecta on 21–25 October 2001. These disturbances included two intense storms (Dst*≈−250 and −180 nT, respectively. The cessation of this activity at the start of 24 October ushered in a peculiar state of the magnetosphere which lasted for about 28 h and which we discuss in this paper. The interplanetary field was dominated by the sunward component [B=(4.29±0.77, −0.30±0.71, 0.49±0.45 nT]. We analyze global indicators of geomagnetic disturbances, polar cap precipitation, ground magnetometer records, and ionospheric convection as obtained from SuperDARN radars. The state of the magnetosphere is characterized by the following features: (i generally weak and patchy (in time low-latitude dayside reconnection or reconnection poleward of the cusps; (ii absence of substorms; (iii a monotonic recovery from the previous storm activity (Dst corrected for magnetopause currents decreasing from ~−65 to ~−35 nT, giving an unforced decreased of ~1.1 nT/h; (iv the probable absence of viscous-type interaction originating from the Kelvin-Helmholtz (KH instability; (v a cross-polar cap potential of just 20–30 kV; (vi a persistent, polar cap region containing (vii very weak, and sometimes absent, electron precipitation and no systematic inter-hemisphere asymmetry. Whereas we therefore infer the presence of a moderate amount of open flux, the convection is generally weak and patchy, which we ascribe to the lack of solar wind driver. This magnetospheric state approaches that predicted by Cowley and Lockwood (1992 but has never yet been observed.

  1. Weak polyelectrolyte complexation driven by associative charging

    Science.gov (United States)

    Rathee, Vikramjit S.; Zervoudakis, Aristotle J.; Sidky, Hythem; Sikora, Benjamin J.; Whitmer, Jonathan K.

    2018-03-01

    Weak polyelectrolytes are relevant for a wide range of fields; in particular, they have been investigated as "smart" materials for chemical separations and drug delivery. The charges on weak polyelectrolytes are dynamic, causing polymer chains to adopt different equilibrium conformations even with relatively small changes to the surrounding environment. Currently, there exists no comprehensive picture of this behavior, particularly where polymer-polymer interactions have the potential to affect charging properties significantly. In this study, we elucidate the novel interplay between weak polyelectrolyte charging and complexation behavior through coupled molecular dynamics and Monte Carlo simulations. Specifically, we investigate a model of two equal-length and oppositely charging polymer chains in an implicit salt solution represented through Debye-Hückel interactions. The charging tendency of each chain, along with the salt concentration, is varied to determine the existence and extent of cooperativity in charging and complexation. Strong cooperation in the charging of these chains is observed at large Debye lengths, corresponding to low salt concentrations, while at lower Debye lengths (higher salt concentrations), the chains behave in apparent isolation. When the electrostatic coupling is long-ranged, we find that a highly charged chain strongly promotes the charging of its partner chain, even if the environment is unfavorable for an isolated version of that partner chain. Evidence of this phenomenon is supported by a drop in the potential energy of the system, which does not occur at the lower Debye lengths where both potential energies and charge fractions converge for all partner chain charging tendencies. The discovery of this cooperation will be helpful in developing "smart" drug delivery mechanisms by allowing for better predictions for the dissociation point of delivery complexes.

  2. Single-Photon Optomechanics

    Science.gov (United States)

    Nunnenkamp, A.; Børkje, K.; Girvin, S. M.

    2011-08-01

    Optomechanics experiments are rapidly approaching the regime where the radiation pressure of a single photon displaces the mechanical oscillator by more than its zero-point uncertainty. We show that in this limit the power spectrum has multiple sidebands and that the cavity response has several resonances in the resolved-sideband limit. Using master-equation simulations, we also study the crossover from the weak-coupling many-photon to the single-photon strong-coupling regime. Finally, we find non-Gaussian steady states of the mechanical oscillator when multiphoton transitions are resonant. Our study provides the tools to detect and take advantage of this novel regime of optomechanics.

  3. [The weakness of individual psychologic dream theory].

    Science.gov (United States)

    Strunz, F

    1988-05-13

    This article undertakes a critical evaluation of Adlerian dream theory. The main weakness of the theory is found to be its lack of an inherent instance of truth that shows the dreamer the way to a better and more feasible life style. Contemporary Adlerians' treatment of the master's dream dogmas and their practical use in psychotherapy are described. There seems to be a convergence movement of today's practical application methods of the dream in all psychotherapeutic schools. Adlerian dream interpretation in the original sense intended by Adler is practised nowhere by psychotherapists today and seems largely antiquated.

  4. Magnetic braking in weakly ionized media

    Science.gov (United States)

    Konigl, Arieh

    1987-01-01

    The combined magnetic braking-ambipolar diffusion problem in weakly ionized, rigidly rotating disks is studied. An analytical solution is presented for a disk whose angular velocity and magnetic yield vectors are aligned with the symmetry axis, illustrating the effects of the relative azimuthal drift of neutrals and ions. The effects of radial drift are added, commenting on the ratio of the characteristic ambipolar diffusion and magnetic braking time scales in high-mass and low-mass disks. A numerical calculation is used to show the combined action of these two processes.

  5. Superconductor in a weak static gravitational field

    Energy Technology Data Exchange (ETDEWEB)

    Ummarino, Giovanni Alberto [Dipartimento DISAT, Politecnico di Torino, Turin (Italy); National Research Nuclear University MEPhI-Moscow Engineering Physics Institute, Moscow (Russian Federation); Gallerati, Antonio [Dipartimento DISAT, Politecnico di Torino, Turin (Italy)

    2017-08-15

    We provide the detailed calculation of a general form for Maxwell and London equations that takes into account gravitational corrections in linear approximation. We determine the possible alteration of a static gravitational field in a superconductor making use of the time-dependent Ginzburg-Landau equations, providing also an analytic solution in the weak field condition. Finally, we compare the behavior of a high-T{sub c} superconductor with a classical low-T{sub c} superconductor, analyzing the values of the parameters that can enhance the reduction of the gravitational field. (orig.)

  6. Electric weak interaction at high energies

    International Nuclear Information System (INIS)

    Satsunkevich, I.S.

    1979-01-01

    An analysis of an experimental evidence for the existence of W +- , Z 0 and H-bosons obtained at c.m.s. energies (10-60) GeV is carried out in order to establish the gauge group of magnetic electro and weak interactions. Indirect testing techniques of the Weinberg-Salam model via the study of interference near-resonance phenomena between near-resonances and resonance amplitudes are evaluated. The usefullness of near-resonance interference for better evaluation of properties of a Z 0 meson is pointed out [ru

  7. Weak mixing angles and heavy flavours

    International Nuclear Information System (INIS)

    Jarlskog, C.

    1984-05-01

    The present status of the weak mixing angles, in the standard six quark model, is reviewed. The implications of the recent measurements of the beauty lifetime and branching ratios are discussed, in the framework of the Kobayashi-Maskawa and the Wolfenstein parametrizations. Expectations for B(sup)o - B(sup)-o mixing and consequences for the collider data are given. Other topics briefly reviewed are CP-violation, top quark mass and possible implications of the existence of a fourth family. (author)

  8. Spectral line profiles in weakly turbulent plasmas

    International Nuclear Information System (INIS)

    Capes, H.; Voslamber, D.

    1976-07-01

    The unified theory of line broadening by electron perturbers is generalized to include the case of a weakly turbulent plasma. The collision operator in the line shape expression is shown to be the sum of two terms, both containing effects arising from the non-equilibrium nature of the plasma. One of the two terms represents the influence of individual atom-particle interactions occuring via the nonequilibrium dielectric plasma medium. The other term is due to the interaction of the atom with the turbulent waves. Both terms contain damping and diffusion effects arising from the plasma turbulence

  9. Transition to reconstructibility in weakly coupled networks.

    Directory of Open Access Journals (Sweden)

    Benedict J Lünsmann

    Full Text Available Across scientific disciplines, thresholded pairwise measures of statistical dependence between time series are taken as proxies for the interactions between the dynamical units of a network. Yet such correlation measures often fail to reflect the underlying physical interactions accurately. Here we systematically study the problem of reconstructing direct physical interaction networks from thresholding correlations. We explicate how local common cause and relay structures, heterogeneous in-degrees and non-local structural properties of the network generally hinder reconstructibility. However, in the limit of weak coupling strengths we prove that stationary systems with dynamics close to a given operating point transition to universal reconstructiblity across all network topologies.

  10. Probing hysteretic elasticity in weakly nonlinear materials

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Paul A [Los Alamos National Laboratory; Haupert, Sylvain [UPMC UNIV PARIS; Renaud, Guillaume [UPMC UNIV PARIS; Riviere, Jacques [UPMC UNIV PARIS; Talmant, Maryline [UPMC UNIV PARIS; Laugier, Pascal [UPMC UNIV PARIS

    2010-12-07

    Our work is aimed at assessing the elastic and dissipative hysteretic nonlinear parameters' repeatability (precision) using several classes of materials with weak, intermediate and high nonlinear properties. In this contribution, we describe an optimized Nonlinear Resonant Ultrasound Spectroscopy (NRUS) measuring and data processing protocol applied to small samples. The protocol is used to eliminate the effects of environmental condition changes that take place during an experiment, and that may mask the intrinsic elastic nonlinearity. As an example, in our experiments, we identified external temperature fluctuation as a primary source of material resonance frequency and elastic modulus variation. A variation of 0.1 C produced a frequency variation of 0.01 %, which is similar to the expected nonlinear frequency shift for weakly nonlinear materials. In order to eliminate environmental effects, the variation in f{sub 0} (the elastically linear resonance frequency proportional to modulus) is fit with the appropriate function, and that function is used to correct the NRUS calculation of nonlinear parameters. With our correction procedure, we measured relative resonant frequency shifts of 10{sup -5} , which are below 10{sup -4}, often considered the limit to NRUS sensitivity under common experimental conditions. Our results show that the procedure is an alternative to the stringent control of temperature often applied. Applying the approach, we report nonlinear parameters for several materials, some with very small nonclassical nonlinearity. The approach has broad application to NRUS and other Nonlinear Elastic Wave Spectroscopy approaches.

  11. Do weak global stresses synchronize earthquakes?

    Science.gov (United States)

    Bendick, R.; Bilham, R.

    2017-08-01

    Insofar as slip in an earthquake is related to the strain accumulated near a fault since a previous earthquake, and this process repeats many times, the earthquake cycle approximates an autonomous oscillator. Its asymmetric slow accumulation of strain and rapid release is quite unlike the harmonic motion of a pendulum and need not be time predictable, but still resembles a class of repeating systems known as integrate-and-fire oscillators, whose behavior has been shown to demonstrate a remarkable ability to synchronize to either external or self-organized forcing. Given sufficient time and even very weak physical coupling, the phases of sets of such oscillators, with similar though not necessarily identical period, approach each other. Topological and time series analyses presented here demonstrate that earthquakes worldwide show evidence of such synchronization. Though numerous studies demonstrate that the composite temporal distribution of major earthquakes in the instrumental record is indistinguishable from random, the additional consideration of event renewal interval serves to identify earthquake groupings suggestive of synchronization that are absent in synthetic catalogs. We envisage the weak forces responsible for clustering originate from lithospheric strain induced by seismicity itself, by finite strains over teleseismic distances, or by other sources of lithospheric loading such as Earth's variable rotation. For example, quasi-periodic maxima in rotational deceleration are accompanied by increased global seismicity at multidecadal intervals.

  12. Weak pion production off the nucleon

    International Nuclear Information System (INIS)

    Hernandez, E.; Nieves, J.; Valverde, M.

    2007-01-01

    We develop a model for the weak pion production off the nucleon, which besides the delta pole mechanism [weak excitation of the Δ(1232) resonance and its subsequent decay into Nπ], includes also some background terms required by chiral symmetry. We refit the C 5 A (q 2 ) form factor to the flux-averaged ν μ p→μ - pπ + ANL q 2 -differential cross section data, finding a substantially smaller contribution of the delta pole mechanism than traditionally assumed in the literature. Within this scheme, we calculate several differential and integrated cross sections, including pion angular distributions, induced by neutrinos and antineutrinos and driven both by charged and neutral currents. In all cases we find that the background terms produce quite significant effects, and that they lead to an overall improved description of the data, as compared to the case where only the delta pole mechanism is considered. We also show that the interference between the delta pole and the background terms produces parity-violating contributions to the pion angular differential cross section, which are intimately linked to T-odd correlations in the contraction between the leptonic and hadronic tensors. However, these latter correlations do not imply a genuine violation of time-reversal invariance because of the existence of strong final state interaction effects

  13. Weak gravity conjecture and effective field theory

    Science.gov (United States)

    Saraswat, Prashant

    2017-01-01

    The weak gravity conjecture (WGC) is a proposed constraint on theories with gauge fields and gravity, requiring the existence of light charged particles and/or imposing an upper bound on the field theory cutoff Λ . If taken as a consistency requirement for effective field theories (EFTs), it rules out possibilities for model building including some models of inflation. I demonstrate simple models which satisfy all forms of the WGC, but which through Higgsing of the original gauge fields produce low-energy EFTs with gauge forces that badly violate the WGC. These models illustrate specific loopholes in arguments that motivate the WGC from a bottom-up perspective; for example the arguments based on magnetic monopoles are evaded when the magnetic confinement that occurs in a Higgs phase is accounted for. This indicates that the WGC should not be taken as a veto on EFTs, even if it turns out to be a robust property of UV quantum gravity theories. However, if the latter is true, then parametric violation of the WGC at low energy comes at the cost of nonminimal field content in the UV. I propose that only a very weak constraint is applicable to EFTs, Λ ≲(log 1/g )-1 /2Mpl , where g is the gauge coupling, motivated by entropy bounds. Remarkably, EFTs produced by Higgsing a theory that satisfies the WGC can saturate but not violate this bound.

  14. Rindler fluid with weak momentum relaxation

    Science.gov (United States)

    Khimphun, Sunly; Lee, Bum-Hoon; Park, Chanyong; Zhang, Yun-Long

    2018-01-01

    We realize the weak momentum relaxation in Rindler fluid, which lives on the time-like cutoff surface in an accelerating frame of flat spacetime. The translational invariance is broken by massless scalar fields with weak strength. Both of the Ward identity and the momentum relaxation rate of Rindler fluid are obtained, with higher order correction in terms of the strength of momentum relaxation. The Rindler fluid with momentum relaxation could also be approached through the near horizon limit of cutoff AdS fluid with momentum relaxation, which lives on a finite time-like cutoff surface in Anti-de Sitter(AdS) spacetime, and further could be connected with the holographic conformal fluid living on AdS boundary at infinity. Thus, in the holographic Wilson renormalization group flow of the fluid/gravity correspondence with momentum relaxation, the Rindler fluid can be considered as the Infrared Radiation(IR) fixed point, and the holographic conformal fluid plays the role of the ultraviolet(UV) fixed point.

  15. Matrix strings in weakly curved background fields

    International Nuclear Information System (INIS)

    Schiappa, Ricardo

    2001-01-01

    We investigate further the recent proposal for the form of the Matrix theory action in weak background fields. We perform DVV reduction to the multiple D0-brane action in order to find the Matrix string theory action for multiple fundamental strings in curved but weak NSNS and RR backgrounds. This matrix sigma model gives a definite prescription on how to deal with RR fields with an explicit spacetime dependence in Type II string theory. We do this both via the 9-11 flip and the chain of T and S dualities, and further check on their equivalence explicitly. In order to do so, we also discuss the implementation of S-duality in the operators of the 2-dimensional worldvolume supersymmetric gauge theory describing the Type IIB D-string. We compare the result to the known Green-Schwarz sigma model action (for one string), and use this comparison in order to discuss about possible, non-linear background curvature corrections to the Matrix string action (involving many strings), and therefore to the Matrix theory action. We illustrate the nonabelian character of our action with an example involving multiple fundamental strings in a nontrivial RR flux, where the strings are polarized into a noncommutative configuration. This corresponds to a dielectric type of effect on fundamental strings

  16. Conformational transitions of a weak polyampholyte

    KAUST Repository

    Nair, Arun Kumar Narayanan

    2014-10-07

    Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.

  17. Electrowetting of Weak Polyelectrolyte-Coated Surfaces.

    Science.gov (United States)

    Sénéchal, Vincent; Saadaoui, Hassan; Rodriguez-Hernandez, Juan; Drummond, Carlos

    2017-05-23

    Polymer coatings are commonly used to modify interfacial properties like wettability, lubrication, or biocompatibility. These properties are determined by the conformation of polymer molecules at the interface. Polyelectrolytes are convenient elementary bricks to build smart materials, given that polyion chain conformation is very sensitive to different environmental variables. Here we discuss the effect of an applied electric field on the properties of surfaces coated with poly(acrylic acid) brushes. By combining atomic force microscopy, quartz crystal microbalance, and contact angle experiments, we show that it is possible to precisely tune polyion chain conformation, surface adhesion, and surface wettability using very low applied voltages if the polymer grafting density and environmental conditions (pH and ionic strength) are properly formulated. Our results indicate that the effective ionization degree of the grafted weak polyacid can be finely controlled with the externally applied field, with important consequences for the macroscopic surface properties.

  18. Casimir apparatuses in a weak gravitational field

    DEFF Research Database (Denmark)

    Bimonte, Giuseppe; Calloni, Enrico; Esposito, Giampiero

    2009-01-01

    We review and assess a part of the recent work on Casimir apparatuses in the weak gravitational field of the Earth. For a free, real massless scalar field subject to Dirichlet or Neumann boundary conditions on the parallel plates, the resulting regularized and renormalized energy-momentum tensor...... is covariantly conserved, while the trace anomaly vanishes if the massless field is conformally coupled to gravity. Conformal coupling also ensures a finite Casimir energy and finite values of the pressure upon parallel plates. These results have been extended to an electromagnetic field subject to perfect...... conductor (hence idealized) boundary conditions on parallel plates, by various authors. The regularized and renormalized energy-momentum tensor has beene valuated up to second order in the gravity acceleration. In both the scalar and the electromagnetic case, studied to first order in the gravity...

  19. Determination of light yield from weak scintillations

    International Nuclear Information System (INIS)

    Mandzhukov, I.G.; Mandzhukova, B.V.

    1987-01-01

    Simulation of amplitude distribution of weak scintillation pulses by Puasson distribution is suggestd, if average number of photoelectrons collected on the first dinode of the photomultiplier is of the order of 1. The method permits to determine scintillation yield even in those cases, when the photomultiplier does not have a maximum in monoelectron pulse distribution. Scintillation yields of some aqueous solutions of sodium salicylate and aromatic solvents (benzene, toluene, xylol) at inner α-particle irradiation are determined. It is observed from the given results that efficiency of 239 Pu α-particle detection for aqueous solutions of sodium salicylate with 10% concentration is rather high; it makes up 0.94. They may appear useful for applied problems, paticularly, for measuring α-radiation

  20. Molecular dynamics simulations of weak detonations.

    Science.gov (United States)

    Am-Shallem, Morag; Zeiri, Yehuda; Zybin, Sergey V; Kosloff, Ronnie

    2011-12-01

    Detonation of a three-dimensional reactive nonisotropic molecular crystal is modeled using molecular dynamics simulations. The detonation process is initiated by an impulse, followed by the creation of a stable fast reactive shock wave. The terminal shock velocity is independent of the initiation conditions. Further analysis shows supersonic propagation decoupled from the dynamics of the decomposed material left behind the shock front. The dependence of the shock velocity on crystal nonlinear compressibility resembles solitary behavior. These properties categorize the phenomena as a weak detonation. The dependence of the detonation wave on microscopic potential parameters was investigated. An increase in detonation velocity with the reaction exothermicity reaching a saturation value is observed. In all other respects the model crystal exhibits typical properties of a molecular crystal.

  1. Weak and strong typicality in quantum systems.

    Science.gov (United States)

    Santos, Lea F; Polkovnikov, Anatoli; Rigol, Marcos

    2012-07-01

    We study the properties of mixed states obtained from eigenstates of many-body lattice Hamiltonians after tracing out part of the lattice. Two scenarios emerge for generic systems: (i) The diagonal entropy becomes equivalent to the thermodynamic entropy when a few sites are traced out (weak typicality); and (ii) the von Neumann (entanglement) entropy becomes equivalent to the thermodynamic entropy when a large fraction of the lattice is traced out (strong typicality). Remarkably, the results for few-body observables obtained with the reduced, diagonal, and canonical density matrices are very similar to each other, no matter which fraction of the lattice is traced out. Hence, for all physical quantities studied here, the results in the diagonal ensemble match the thermal predictions.

  2. General gauge mediation at the weak scale

    Energy Technology Data Exchange (ETDEWEB)

    Knapen, Simon [Berkeley Center for Theoretical Physics,University of California, Berkeley, CA 94720 (United States); Theoretical Physics Group, Lawrence Berkeley National Laboratory,Berkeley, CA 94720 (United States); Redigolo, Diego [Sorbonne Universités, UPMC Univ Paris 06,UMR 7589, LPTHE, F-75005, Paris (France); CNRS, UMR 7589,LPTHE, F-75005, Paris (France); Shih, David [New High Energy Theory Center, Rutgers University,Piscataway, NJ 08854 (United States)

    2016-03-09

    We completely characterize General Gauge Mediation (GGM) at the weak scale by solving all IR constraints over the full parameter space. This is made possible through a combination of numerical and analytical methods, based on a set of algebraic relations among the IR soft masses derived from the GGM boundary conditions in the UV. We show how tensions between just a few constraints determine the boundaries of the parameter space: electroweak symmetry breaking (EWSB), the Higgs mass, slepton tachyons, and left-handed stop/sbottom tachyons. While these constraints allow the left-handed squarks to be arbitrarily light, they place strong lower bounds on all of the right-handed squarks. Meanwhile, light EW superpartners are generic throughout much of the parameter space. This is especially the case at lower messenger scales, where a positive threshold correction to m{sub h} coming from light Higgsinos and winos is essential in order to satisfy the Higgs mass constraint.

  3. On Uniform Weak König's Lemma

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich

    2002-01-01

    but are 20-conservative over primitive recursive arithmetic PRA (and even weaker fragments of arithmetic). In Kohlenbach [10] (J. Symbolic Logic 57 (1992) 1239-1273) we established such conservation results relative to finite type extensions PRA of PRA (together with a quantifier-free axiom of choice schema...... which-relative to PRA -implies the schema of 10-induction). In this setting one can consider also a uniform version UWKL of WKL which asserts the existence of a functional which selects uniformly in a given infinite binary tree f an infinite path f of that tree. This uniform version of WKL...... is of interest in the context of explicit mathematics as developed by S. Feferman. The elimination process in Kohlenbach [10] actually can be used to eliminate even this uniform weak Konig's lemma provided that PRA only has a quantifier-free rule of extensionality QF-ER instead of the full axioms (E...

  4. Electromagnetic and weak observables in the context of the shell model

    International Nuclear Information System (INIS)

    Wildenthal, B.H.

    1984-01-01

    Wave functions for A = 17-39 nuclei have been obtained from diagonalizations of a single Hamiltonian formulation in the complete sd-shell configuration space for each NTJ system. These wave functions are used to generate the one-body density matrices corresponding to weak and electromagnetic transitions and moments. These densities are combined with different assumptions for the single-particle matrix elements of the weak and electromagnetic operators to produce theoretical matrix elements. The predictions are compared with experiment to determine, in some ''linearly dependent'' fashion, the correctness of the wave functions themselves, the optimum values of the single-particle matrix elements, and the viability of the overall shell-model formulation. (author)

  5. Anomalous weak values and the violation of a multiple-measurement Leggett-Garg inequality

    Science.gov (United States)

    Avella, Alessio; Piacentini, Fabrizio; Borsarelli, Michelangelo; Barbieri, Marco; Gramegna, Marco; Lussana, Rudi; Villa, Federica; Tosi, Alberto; Degiovanni, Ivo Pietro; Genovese, Marco

    2017-11-01

    Quantum mechanics presents peculiar properties that, on the one hand, have been the subject of several theoretical and experimental studies about its very foundations and, on the other hand, provide tools for developing new technologies, the so-called quantum technologies. The nonclassicality pointed out by Leggett-Garg inequalities has represented, with Bell inequalities, one of the most investigated subjects. In this article we study the connection of Leggett-Garg inequalities with a new emerging field of quantum measurement, the weak values in the case of a series of sequential measurements on a single object. In detail, we perform an experimental study of the four-time-correlator Leggett-Garg test, by exploiting single and sequential weak measurements performed on heralded single photons.

  6. Pre-relaxation in weakly interacting models

    Science.gov (United States)

    Bertini, Bruno; Fagotti, Maurizio

    2015-07-01

    We consider time evolution in models close to integrable points with hidden symmetries that generate infinitely many local conservation laws that do not commute with one another. The system is expected to (locally) relax to a thermal ensemble if integrability is broken, or to a so-called generalised Gibbs ensemble if unbroken. In some circumstances expectation values exhibit quasi-stationary behaviour long before their typical relaxation time. For integrability-breaking perturbations, these are also called pre-thermalisation plateaux, and emerge e.g. in the strong coupling limit of the Bose-Hubbard model. As a result of the hidden symmetries, quasi-stationarity appears also in integrable models, for example in the Ising limit of the XXZ model. We investigate a weak coupling limit, identify a time window in which the effects of the perturbations become significant and solve the time evolution through a mean-field mapping. As an explicit example we study the XYZ spin-\\frac{1}{2} chain with additional perturbations that break integrability. One of the most intriguing results of the analysis is the appearance of persistent oscillatory behaviour. To unravel its origin, we study in detail a toy model: the transverse-field Ising chain with an additional nonlocal interaction proportional to the square of the transverse spin per unit length (2013 Phys. Rev. Lett. 111 197203). Despite being nonlocal, this belongs to a class of models that emerge as intermediate steps of the mean-field mapping and shares many dynamical properties with the weakly interacting models under consideration.

  7. Anomalous baryogenesis at the weak scale

    International Nuclear Information System (INIS)

    Singleton, R.L. Jr.

    1991-06-01

    One of the fundamental constants of nature is the baryon asymmetry of the universe -- the ratio of the number of baryons to the entropy. This constant is about 10 -11 . In baryon- number conserving theories, this was just an initial condition. With the advent of the grand unified theories (GUTs), baryon number is no longer conserved, and this asymmetry can be generated dynamically. Unfortunately, however, there are reasons for preferring another mechanism. For example, GUTs predict proton decay which, after extensive searches, has not been found. An alternative place to look for baryogenesis is the electroweak phase transition, described by the standard model, which posses all the necessary ingredients for baryogenesis. Anomalous baryon-number violation in weak interactions becomes large at high temperatures, which offers the prospect of creating the asymmetry with the standard model or minimal extensions. This can just barely be done if certain conditions are fulfilled. CP violation must be large, which rules out the minimal standard model as the source of the asymmetry, but which is easily arranged with an extended Higgs sector. The baryon-number violating rates themselves are not exactly known, and they must be pushed to their theoretical limits. A more exact determination of these rates is needed before a definitive answer can be given. Finally, the phase transition must be at least weakly first order. Such phase transitions are accompanied by the formation and expansion of bubbles of true vacuum within the false vacuum, much like the boiling of water. As the bubbles expand, they provide a departure from thermal equilibrium, otherwise the dynamics will adjust the net baryon number to zero. The bubble expansion also provides a biasing that creates an asymmetry on the bubbles surface. Under optimal conditions, the observed asymmetry can just be produced. 31 refs., 10 figs

  8. Normal modes of weak colloidal gels

    Science.gov (United States)

    Varga, Zsigmond; Swan, James W.

    2018-01-01

    The normal modes and relaxation rates of weak colloidal gels are investigated in calculations using different models of the hydrodynamic interactions between suspended particles. The relaxation spectrum is computed for freely draining, Rotne-Prager-Yamakawa, and accelerated Stokesian dynamics approximations of the hydrodynamic mobility in a normal mode analysis of a harmonic network representing several colloidal gels. We find that the density of states and spatial structure of the normal modes are fundamentally altered by long-ranged hydrodynamic coupling among the particles. Short-ranged coupling due to hydrodynamic lubrication affects only the relaxation rates of short-wavelength modes. Hydrodynamic models accounting for long-ranged coupling exhibit a microscopic relaxation rate for each normal mode, λ that scales as l-2, where l is the spatial correlation length of the normal mode. For the freely draining approximation, which neglects long-ranged coupling, the microscopic relaxation rate scales as l-γ, where γ varies between three and two with increasing particle volume fraction. A simple phenomenological model of the internal elastic response to normal mode fluctuations is developed, which shows that long-ranged hydrodynamic interactions play a central role in the viscoelasticity of the gel network. Dynamic simulations of hard spheres that gel in response to short-ranged depletion attractions are used to test the applicability of the density of states predictions. For particle concentrations up to 30% by volume, the power law decay of the relaxation modulus in simulations accounting for long-ranged hydrodynamic interactions agrees with predictions generated by the density of states of the corresponding harmonic networks as well as experimental measurements. For higher volume fractions, excluded volume interactions dominate the stress response, and the prediction from the harmonic network density of states fails. Analogous to the Zimm model in polymer

  9. Anomalous baryogenesis at the weak scale

    Energy Technology Data Exchange (ETDEWEB)

    Singleton, R.L. Jr.

    1991-06-01

    One of the fundamental constants of nature is the baryon asymmetry of the universe -- the ratio of the number of baryons to the entropy. This constant is about 10{sup {minus}11}. In baryon- number conserving theories, this was just an initial condition. With the advent of the grand unified theories (GUTs), baryon number is no longer conserved, and this asymmetry can be generated dynamically. Unfortunately, however, there are reasons for preferring another mechanism. For example, GUTs predict proton decay which, after extensive searches, has not been found. An alternative place to look for baryogenesis is the electroweak phase transition, described by the standard model, which posses all the necessary ingredients for baryogenesis. Anomalous baryon-number violation in weak interactions becomes large at high temperatures, which offers the prospect of creating the asymmetry with the standard model or minimal extensions. This can just barely be done if certain conditions are fulfilled. CP violation must be large, which rules out the minimal standard model as the source of the asymmetry, but which is easily arranged with an extended Higgs sector. The baryon-number violating rates themselves are not exactly known, and they must be pushed to their theoretical limits. A more exact determination of these rates is needed before a definitive answer can be given. Finally, the phase transition must be at least weakly first order. Such phase transitions are accompanied by the formation and expansion of bubbles of true vacuum within the false vacuum, much like the boiling of water. As the bubbles expand, they provide a departure from thermal equilibrium, otherwise the dynamics will adjust the net baryon number to zero. The bubble expansion also provides a biasing that creates an asymmetry on the bubbles surface. Under optimal conditions, the observed asymmetry can just be produced. 31 refs., 10 figs.

  10. Precision cluster mass determination from weak lensing

    Science.gov (United States)

    Mandelbaum, Rachel; Seljak, Uroš; Baldauf, Tobias; Smith, Robert E.

    2010-07-01

    Weak gravitational lensing has been used extensively in the past decade to constrain the masses of galaxy clusters, and is the most promising observational technique for providing the mass calibration necessary for precision cosmology with clusters. There are several challenges in estimating cluster masses, particularly (a) the sensitivity to astrophysical effects and observational systematics that modify the signal relative to the theoretical expectations, and (b) biases that can arise due to assumptions in the mass estimation method, such as the assumed radial profile of the cluster. All of these challenges are more problematic in the inner regions of the cluster, suggesting that their influence would ideally be suppressed for the purpose of mass estimation. However, at any given radius the differential surface density measured by lensing is sensitive to all mass within that radius, and the corrupted signal from the inner parts is spread out to all scales. We develop a new statistic Υ(RR0) that is ideal for estimation of cluster masses because it completely eliminates mass contributions below a chosen scale (which we suggest should be about 20 per cent of the virial radius), and thus reduces sensitivity to systematic and astrophysical effects. We use simulated and analytical profiles including shape noise to quantify systematic biases on the estimated masses for several standard methods of mass estimation, finding that these can lead to significant mass biases that range from 10 to over 50 per cent. The mass uncertainties when using the new statistic Υ(RR0) are reduced by up to a factor of 10 relative to the standard methods, while only moderately increasing the statistical errors. This new method of mass estimation will enable a higher level of precision in future science work with weak lensing mass estimates for galaxy clusters.

  11. Magnified Weak Lensing Cross Correlation Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, Melville P., Clowe, Douglas I.

    2010-11-30

    This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60

  12. Effects of weak localization in quasi-one-dimensional electronic system over liquid helium

    CERN Document Server

    Kovdrya, Y Z; Gladchenko, S P

    2001-01-01

    One measured rho sub x sub x magnetoresistance of a quasi-one-dimensional electronic system over liquid helium within gas scattering range (1.3-2.0 K temperature range). It is shown that with increase of magnetic field the magnetoresistance is reduced at first and them upon passing over minimum it begins to increase from rho sub x sub x approx B sup 2 law. One anticipated that the negative magnetoresistance detected in the course of experiments resulted from the effects of weak localization. The experiment results are in qualitative conformity with the theoretical model describing processes of weak localization in single-dimensional nondegenerate electronic systems

  13. Weakly Idempotent Lattices and Bilattices, Non-Idempotent Plonka Functions

    Directory of Open Access Journals (Sweden)

    Davidova D. S.

    2015-12-01

    Full Text Available In this paper, we study weakly idempotent lattices with an additional interlaced operation. We characterize interlacity of a weakly idempotent semilattice operation, using the concept of hyperidentity and prove that a weakly idempotent bilattice with an interlaced operation is epimorphic to the superproduct with negation of two equal lattices. In the last part of the paper, we introduce the concepts of a non-idempotent Plonka function and the weakly Plonka sum and extend the main result for algebras with the well known Plonka function to the algebras with the non-idempotent Plonka function. As a consequence, we characterize the hyperidentities of the variety of weakly idempotent lattices, using non-idempotent Plonka functions, weakly Plonka sums and characterization of cardinality of the sets of operations of subdirectly irreducible algebras with hyperidentities of the variety of weakly idempotent lattices. Applications of weakly idempotent bilattices in multi-valued logic is to appear.

  14. Weak Disposability in Nonparametric Production Analysis with Undesirable Outputs

    NARCIS (Netherlands)

    Kuosmanen, T.K.

    2005-01-01

    Environmental Economics and Natural Resources Group at Wageningen University in The Netherlands Weak disposability of outputs means that firms can abate harmful emissions by decreasing the activity level. Modeling weak disposability in nonparametric production analysis has caused some confusion.

  15. Qubit state tomography in a superconducting circuit via weak measurements

    Science.gov (United States)

    Qin, Lupei; Xu, Luting; Feng, Wei; Li, Xin-Qi

    2017-03-01

    In this work we present a study on a new scheme for measuring the qubit state in a circuit quantum electrodynamics (QED) system, based on weak measurement and the concept of weak value. To be applicable under generic parameter conditions, our formulation and analysis are carried out for finite-strength weak measurement, and in particular beyond the bad-cavity and weak-response limits. The proposed study is accessible to present state-of-the-art circuit QED experiments.

  16. Representations of weak and strong integrals in banach spaces.

    Science.gov (United States)

    Brooks, J K

    1969-06-01

    We establish a representation of the Gelfand-Pettis (weak) integral in terms of unconditionally convergent series. Moreover, absolute convergence of the series is a necessary and sufficient condition in order that the weak integral coincide with the Bochner integral. Two applications of the representation are given. The first is a simplified proof of the countable additivity and absolute continuity of the indefinite weak integral. The second application is to probability theory; we characterize the conditional expectation of a weakly integrable function.

  17. The influence of weak impacts on certain processes of nanotechnology

    Science.gov (United States)

    Tupik, V. A.; Margolin, V. I.; Potekhin, M. S.

    2017-07-01

    The article deals with the influence of weak and super weak impacts on certain technological processes in nanotechnology related to the synthesis of nanoscale films and coatings. We also touch upon the impacts of weak diffraction fields of complex shape on the formation of fractal films and coatings.

  18. Critical types of Krasnoselskii fixed point theorems in weak topologies

    African Journals Online (AJOL)

    In this note, by means of the technique of measures of weak noncompactness, we establish a generalized form of fixed point theorem for the sum of T + S in weak topology setups of a metrizable locally convex space, where S is not weakly compact, I − T allows to be noninvertible, and T is not necessarily continuous.

  19. Conceptual restrictions on weakly referential constructions : Evidence from modification

    NARCIS (Netherlands)

    Schulpen, M.E.

    2016-01-01

    In this dissertation I investigated the restrictions on so-called weakly referential constructions such as weak definites, bare predicates and bare singular nouns. Weak definites are definite constructions in which the definite doesn’t refer uniquely, such as in (1): Context: Piet spent his evening

  20. Two-dimensional weak pseudomanifolds on eight vertices

    Indian Academy of Sciences (India)

    We explicitly determine all the two-dimensional weak pseudomanifolds on 8 vertices. We prove that there are (up to isomorphism) exactly 95 such weak pseudomanifolds, 44 of which are combinatorial 2-manifolds. These 95 weak pseudomanifolds triangulate 16 topological spaces. As a consequence, we prove that there ...

  1. Spatial acuity and prey detection in weakly electric fish.

    Directory of Open Access Journals (Sweden)

    David Babineau

    2007-03-01

    Full Text Available It is well-known that weakly electric fish can exhibit extreme temporal acuity at the behavioral level, discriminating time intervals in the submicrosecond range. However, relatively little is known about the spatial acuity of the electrosense. Here we use a recently developed model of the electric field generated by Apteronotus leptorhynchus to study spatial acuity and small signal extraction. We show that the quality of sensory information available on the lateral body surface is highest for objects close to the fish's midbody, suggesting that spatial acuity should be highest at this location. Overall, however, this information is relatively blurry and the electrosense exhibits relatively poor acuity. Despite this apparent limitation, weakly electric fish are able to extract the minute signals generated by small prey, even in the presence of large background signals. In fact, we show that the fish's poor spatial acuity may actually enhance prey detection under some conditions. This occurs because the electric image produced by a spatially dense background is relatively "blurred" or spatially uniform. Hence, the small spatially localized prey signal "pops out" when fish motion is simulated. This shows explicitly how the back-and-forth swimming, characteristic of these fish, can be used to generate motion cues that, as in other animals, assist in the extraction of sensory information when signal-to-noise ratios are low. Our study also reveals the importance of the structure of complex electrosensory backgrounds. Whereas large-object spacing is favorable for discriminating the individual elements of a scene, small spacing can increase the fish's ability to resolve a single target object against this background.

  2. Viscous-fluid reaction to a torsionally oscillating spheroid Linearized steady-state weak-separation solution

    Science.gov (United States)

    Tompkins, D. R., Jr.

    1974-01-01

    For both the linearized prolate and oblate problems, perturbation series for all orders of eccentricity are obtained. The 'weak separation' method of solving partial-differential-equation boundary-value problems assumes that each linearly independent solution is a sum of products of single-variable functions. The method is applied to a hierarchy of partial differential equations. The weak-separation solutions are constructed by generalizing only the Bessel functions of the homogeneous solution.

  3. Stochastic Resonance Phenomenon of Two-coupled Duffing Oscillator and its Application on Weak Signal Detection

    Directory of Open Access Journals (Sweden)

    Yongfeng Wu

    2014-04-01

    Full Text Available By taking two-coupled duffing oscillator system as the research object, the study found under the synergistic effect of weak periodic signal and noise, the two-coupled duffing oscillator system has typical stochastic resonance and even could achieve better output of stochastic resonance than single duffing oscillator. Based on this phenomenon, this paper proposes a new method to detect the weak periodic signal through the stochastic resonance of two-coupled duffing oscillator. The experimental study indicates that we could achieve excellent detection effect by using the method we mentioned in this paper at low SNR (signal-to-noise ratios, especially, it has excellent filter effect for filtering and shaping of weak square signals and has potential values in the application of digital communications.

  4. Study of weak neutral-current effects in (e,e'X) reactions

    International Nuclear Information System (INIS)

    Kleppinger, W.E.

    1985-01-01

    In electron scattering from nuclei, in addition to the usual electromagnetic interaction, unified models of the electromagnetic and weak interactions predict an additional weak neutral-current interaction. When this additional interaction is included, a parity-violating contribution to the cross section due to the interference of the electromagnetic and neutral-weak currents, is present. The purpose of this work was to examine how these effects can be explored in (e,e'X) reactions with polarized incident electrons, where in addition to detecting the scattered electron, a decay particle X, emitted by the excited target nucleus, is also detected. It is found that new interference terms appear in the cross section that are not present in inelastic (e,e') scattering. A model calculation that assumed that the target was excited to a single, intermediate resonance indicates that the angular distribution of X is sensitive to these new terms. Results of this work have been published

  5. Pre-stressed concrete reactor vessel with built-in planes of weakness

    International Nuclear Information System (INIS)

    Dawson, P.; Paton, A.A.; Fleischer, C.C.

    1989-01-01

    This report describes a study that has been carried out to extend previous work to investigate the feasibility of constructing regions of pre-stressed concrete reactor vessels (PCRV) and biological shields which become activated using easily removable blocks, separated by a suitable membrane. The previous study concluded that, from preliminary analyses, such a concept appeared feasible and recommended that further work should be done. The present study was therefore commissioned to carry out more detailed analytical work and to complement this with the design, construction and pressure testing of two small-scale, single-cavity PCRV models, one without planes of weakness and one with planes of weakness immediately behind the cavity liner. The report describes the analyses, the model design, construction and testing, and presents relevant results. It concludes that the planes of weakness concept could offer a means of facilitating the dismantling of activated regions of PCRV, biological shields and similar types of structure

  6. Kinetics of weakly turbulent wave fields

    International Nuclear Information System (INIS)

    Erofeev, V.I.; Malkin, V.M.

    1988-01-01

    Only the first nonvanishing term in the expansion of collision integral in powers of wave enrgy is usually considered. Nevertheless the highr collisional terms in the wave kinetic equation can be dominant in the energy range, where the turbulence still remains weak. These terms can be essential even when they are smaller than the first one, if they violate some of the conservation laws correct in the first approximation. The previous attempts to calculate higher nonlinear terms in the wave kinetic equation resulyed in divergencies. Up to now there was no effctive way to aliminate such divergencies. This problem is solved in the present paper with the help of the Wyld's diagram technique. As a result the structure of collision intgral is clear up in everfy order of its power expansion in wave energy and conditions of a kinetic equation applicability are specified. Th cubic collisional term for waves with the decay dispersion law is calculated correctly as an example of application of this method. 15 refs

  7. Spatial evolutionary games with weak selection.

    Science.gov (United States)

    Nanda, Mridu; Durrett, Richard

    2017-06-06

    Recently, a rigorous mathematical theory has been developed for spatial games with weak selection, i.e., when the payoff differences between strategies are small. The key to the analysis is that when space and time are suitably rescaled, the spatial model converges to the solution of a partial differential equation (PDE). This approach can be used to analyze all [Formula: see text] games, but there are a number of [Formula: see text] games for which the behavior of the limiting PDE is not known. In this paper, we give rules for determining the behavior of a large class of [Formula: see text] games and check their validity using simulation. In words, the effect of space is equivalent to making changes in the payoff matrix, and once this is done, the behavior of the spatial game can be predicted from the behavior of the replicator equation for the modified game. We say predicted here because in some cases the behavior of the spatial game is different from that of the replicator equation for the modified game. For example, if a rock-paper-scissors game has a replicator equation that spirals out to the boundary, space stabilizes the system and produces an equilibrium.

  8. Fast reconnection of weak magnetic fields

    International Nuclear Information System (INIS)

    Zweibel, E.G.

    1998-01-01

    Fast magnetic reconnection refers to annihilation or topological rearrangement of magnetic fields on a timescale that is independent (or nearly independent) of the plasma resistivity. The resistivity of astrophysical plasmas is so low that reconnection is of little practical interest unless it is fast. Yet, the theory of fast magnetic reconnection is on uncertain ground, as models must avoid the tendency of magnetic fields to pile up at the reconnection layer, slowing down the flow. In this paper it is shown that these problems can be avoided to some extent if the flow is three dimensional. On the other hand, it is shown that in the limited but important case of incompressible stagnation point flows, every flow will amplify most magnetic fields. Although examples of fast magnetic reconnection abound, a weak, disordered magnetic field embedded in stagnation point flow will in general be amplified, and should eventually modify the flow. These results support recent arguments against the operation of turbulent resistivity in highly conducting fluids. copyright 1998 American Institute of Physics

  9. Splitting of the weak hypercharge quantum

    International Nuclear Information System (INIS)

    Nielsen, H.B.; Brene, N.

    1990-12-01

    The ratio between the weak hypercharge quantum for particles having no coupling to the gauge bosons corresponding to the semisimple component of the gauge group and the smallest hypercharge quantum for particles that do have such couplings is exceptionally large for the standard model, considering its rank. To compare groups with respect to this property we propose a quantity χ which depends on the rank of the group and the splitting ratio of the hypercharge(s) to be found in the group. The quantity χ has maximal value for the gauge group of the standard model. This suggest that the hypercharge splitting may play an important role either in the origin of the gauge symmetry at a fundamental scale or in some kind of selection mechanism at a scale perhaps nearer to the experimental scale. Such selection mechanism might be what we have called confusion which removes groups with many (so called generalized) automorphisms. The quantity χ tends to be large for groups with few generalized automorphisms. (orig.)

  10. Forensic bitemark identification: weak foundations, exaggerated claims

    Science.gov (United States)

    Saks, Michael J.; Albright, Thomas; Bohan, Thomas L.; Bierer, Barbara E.; Bowers, C. Michael; Bush, Mary A.; Bush, Peter J.; Casadevall, Arturo; Cole, Simon A.; Denton, M. Bonner; Diamond, Shari Seidman; Dioso-Villa, Rachel; Epstein, Jules; Faigman, David; Faigman, Lisa; Fienberg, Stephen E.; Garrett, Brandon L.; Giannelli, Paul C.; Greely, Henry T.; Imwinkelried, Edward; Jamieson, Allan; Kafadar, Karen; Kassirer, Jerome P.; Koehler, Jonathan ‘Jay’; Korn, David; Mnookin, Jennifer; Morrison, Alan B.; Murphy, Erin; Peerwani, Nizam; Peterson, Joseph L.; Risinger, D. Michael; Sensabaugh, George F.; Spiegelman, Clifford; Stern, Hal; Thompson, William C.; Wayman, James L.; Zabell, Sandy; Zumwalt, Ross E.

    2016-01-01

    Abstract Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification—highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications—highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence. PMID:28852538

  11. Relaxion monodromy and the Weak Gravity Conjecture

    International Nuclear Information System (INIS)

    Ibáñez, L.E.; Montero, M.; Uranga, A.M.; Valenzuela, I.

    2016-01-01

    The recently proposed relaxion models require extremely large trans-Planckian axion excursions as well as a potential explicitly violating the axion shift symmetry. The latter property is however inconsistent with the axion periodicity, which corresponds to a gauged discrete shift symmetry. A way to make things consistent is to use monodromy, i.e. both the axion and the potential parameters transform under the discrete shift symmetry. The structure is better described in terms of a 3-form field C μνρ coupling to the SM Higgs through its field strength F 4 . The 4-form also couples linearly to the relaxion, in the Kaloper-Sorbo fashion. The extremely small relaxion-Higgs coupling arises in a see-saw fashion as g≃F 4 /f, with f being the axion decay constant. We discuss constraints on this type of constructions from membrane nucleation and the Weak Gravity Conjecture. The latter requires the existence of membranes, whose too fast nucleation could in principle drive the theory out of control, unless the cut-off scale is lowered. This allows to rule out the simplest models with the QCD axion as relaxion candidate on purely theoretical grounds. We also discuss possible avenues to embed this structure into string theory.

  12. Order and disorder in weakly ionised plasmas

    International Nuclear Information System (INIS)

    Dutt, T.L.; Dhar, P.K.

    1977-01-01

    The observation of some unusual radial structures in discharges in pure He and Ar in a magnetic field is reported. The structures depended on the angle between the discharge tube axis and the magnetic field direction, and support the previously proposed idea that gaseous plasma energised under certain conditions can have regions in which the electrons have an ordered spatial distribution. The weakly ionised high frequency electrodeless discharges were energised at powers between 500 W and 1 kW, coupled to the discharge from an amplifier by a 143 cm quarter-wavelength twin transmission line, connected to two copper bands, 14 cm apart, placed closely around the outside of the discharge tube. The discharge was maintained continuously between the bands in a position centrally between a pair of Helmholtz coils in a horizontal uniform magnetic field. Optical flats sealed to each end of the hard glass tubes made it possible to view the discharges axially. The tubes were 70 cm long and of internal radius 1.84 cm. A pattern of luminous and non-luminous plasma regions was observed, arranged in coaxial symmetry, the complexity of the pattern depending on the magnitude of the magnetic field. Patterns for He are shown and discussed, and comparisons are made with the patterns for Ar. Significant evidence was obtained for the presence of order in the non-luminous regions. It is thought that stationary states are formed under certain conditions, and conditions for their formation are discussed. (U.K.)

  13. Axial polarizability and weak currents in nuclei

    International Nuclear Information System (INIS)

    Ericson, M.

    1977-01-01

    The weak interaction nucleonic coupling constants in nuclei are modified by the presence of the neighbouring nucleons. One type of modification is due to the virtual excitation of the isobars through meson exchange. The influence of the isobars is described by means of the nuclear axial polarizability coefficient. This polarizability is known; it is linked to the p-wave πN scattering volume. A relation is derived between the axial nuclear current and the pion field which incorporates the polarizability effects. This relation has an electromagnetic analogue. It is then possible to derive the axial and pseudoscalar coupling constants from a knowledge of the pion field. This field in turn obeys a Klein-Gordon equation which has to include the isobaric excitations. The propagation of the pion field is similar to that of an electromagnetic wave in a dielectric medium. The strong interaction coupling constant is shown to be renormalized in nuclei by the effect of the various types of correlations. (author)

  14. On Characterizing weak defining hyperplanes (weak Facets in DEA with Constant Returns to Scale Technology

    Directory of Open Access Journals (Sweden)

    Dariush Akbarian

    2017-09-01

    Full Text Available The Production Possibility Set (PPS is defined as a set of inputs and outputs of a system in which inputs can produce outputs. The Production Possibility Set of the Data Envelopment Analysis (DEA model is contain of two types defining hyperplanes (facets; strong and weak efficient facets. In this paper, the problem of finding weak defining hyperplanes of the PPS of the CCR model is dealt with. However, the equation of strong defining hyperplanes of the PPS of the CCR model can be found in this paper. We state and prove some properties relative to our method. To illustrate the applicability of the proposed model, some numerical examples are finally provided. Our algorithm can easily be implemented using existing packages for operation research, such as GAMS.

  15. Piezoceramic Cantilever Sensor Design for Weak-Impact Detection on Plates

    Directory of Open Access Journals (Sweden)

    Young-Sup Lee

    2012-01-01

    Full Text Available A piezoelectric cantilever type sensor for locating the precise weak-impact or touch position on a plate is presented in this paper. Since the importance of human-computer interface such as a touch panel system has been rapidly increasing recently, this study could suggest an appropriate sensor for the detection of a weak-impact point effectively and accurately for such a system. This sensor detects the out-of-plane vibration of a panel when a touch with a finger or pen is applied on it. The sensor is made with a steel beam and a single crystal PMN-PT patch is bonded on the beam, which is designed to detect the base vibration of the panel. The sensor was designed, manufactured to verify the detect ability of a weak-impact and attached on two different plates of a glass of 400 × 400 × 4 mm and a wooden MDF of 600 × 600 × 9 mm. The experiment result of the sensor was compared with that of an accelerometer which can also be used for the same purpose and shows clear weak-impact responses with a narrow-band property at its resonant frequency. It is expected that the cantilever type sensor in this study could be applied to make a simple flat plate into a touch panel when the time difference of arrivals method is used to locate the weak-impact point.

  16. "Weak" opioid analgesics. Codeine, dihydrocodeine and tramadol: no less risky than morphine.

    Science.gov (United States)

    2016-02-01

    So-called weak opioid analgesics are often used to treat severe pain, or when paracetamol or a nonsteroidal anti-inflammatory drug (NSAID) proves inadequate. But are weak opioids any more effective than paracetamol or NSAIDs on nociceptive pain, and are they better tolerated than morphine? To answer these questions, we conducted a review of literature using the standard Prescrire methodology. The potency of codeine and tramadol is strongly influenced by the cytochrome P450 isoenzyme CYP2D6 genotype, which varies widely from one person to another. This explains reports of overdosing or underdosing after administration of standard doses of the two drugs. The potency of morphine and that of buprenorphine, an opioid receptor agonist-antagonist, appears to be independent of CYP2D6 activity. All "weak" opioids can have the same dose-dependent adverse effects as morphine. There is no evidence that, at equivalent analgesic efficacy, weak opioids carry a lower risk of addiction than low-dose morphine. Respiratory depression can occur in ultrarapid metabolisers after brief exposure to standard doses of codeine or tramadol. Similar cases have been reported with dihydrocodeine in patients with renal failure. In addition, tramadol can cause a serotonin syndrome, hypoglycaemia, hyponatraemia and seizures. Several trials have compared different weak opioids in patients with post-operative pain. A single dose of a weak opioid, possibly combined with paracetamol, has greater analgesic efficacy than paracetamol alone but is not more effective than an NSAID alone. There is a dearth of evidence on weak opioids in patients with chronic pain. Available trials fail to show that a weak opioid has markedly superior analgesic efficacy to paracetamol or an NSAID. Sublingual buprenorphine at analgesic doses appears less likely to cause respiratory depression, but it seems to have weak analgesic efficacy. In practice, when opioid therapy is needed, there is no evidence that codeine

  17. Tests of the weak equivalence principle

    Science.gov (United States)

    Speake, C. C.; Will, C. M.

    2012-09-01

    The Einstein equivalence principle is the foundation for general relativity and all metric theories of gravity. Of its three tenets—the equality of acceleration of test bodies, or weak equivalence principle; the validity of Lorentz invariance in local freely falling frames; and the position invariance of local physical laws—the weak equivalence principle has played the most important role historically, and continues to be a focus of intense theoretical and experimental investigation. From the probably apocryphal 16th century demonstrations by Galileo at Pisa's leaning tower to the sensitive torsion-balance measurements of today (both pictured on the cover of this issue), this principle, dubbed WEP, has been crucial to the development of gravitation theory. The universality of the rate of acceleration of all types of matter in a gravitational field can be taken as evidence that gravitation is fundamentally determined by the geometry, or metric, of spacetime. Newton began his magnum opus 'The Principia' with a discussion of WEP and his experiments to verify it, while Einstein took WEP for granted in his construction of general relativity, never once referring to the epochal experiments by Baron Eötvös. The classic 1964 experiment of Roll, Krotkov and Dicke ushered in the modern era of high-precision tests, and the search for a 'fifth force' during the late 1980s (instigated, ironically, by purported anomalies in Eötvös's old data) caused the enterprise to pivot from pure tests of the foundation of GR to searches for new physics beyond the standard model of the non-gravitational interactions. Today, the next generation of experimental tests of WEP are being prepared for launch or are being developed, with the goal of reaching unprecedented levels of sensitivity, in search of signatures of interactions inspired by string theory, extra dimensions and other concepts from the world of high-energy physics. At the same time observations continue using lunar laser

  18. Weak lensing galaxy cluster field reconstruction

    Science.gov (United States)

    Jullo, E.; Pires, S.; Jauzac, M.; Kneib, J.-P.

    2014-02-01

    In this paper, we compare three methods to reconstruct galaxy cluster density fields with weak lensing data. The first method called FLens integrates an inpainting concept to invert the shear field with possible gaps, and a multi-scale entropy denoising procedure to remove the noise contained in the final reconstruction, that arises mostly from the random intrinsic shape of the galaxies. The second and third methods are based on a model of the density field made of a multi-scale grid of radial basis functions. In one case, the model parameters are computed with a linear inversion involving a singular value decomposition (SVD). In the other case, the model parameters are estimated using a Bayesian Monte Carlo Markov Chain optimization implemented in the lensing software LENSTOOL. Methods are compared on simulated data with varying galaxy density fields. We pay particular attention to the errors estimated with resampling. We find the multi-scale grid model optimized with Monte Carlo Markov Chain to provide the best results, but at high computational cost, especially when considering resampling. The SVD method is much faster but yields noisy maps, although this can be mitigated with resampling. The FLens method is a good compromise with fast computation, high signal-to-noise ratio reconstruction, but lower resolution maps. All three methods are applied to the MACS J0717+3745 galaxy cluster field, and reveal the filamentary structure discovered in Jauzac et al. We conclude that sensitive priors can help to get high signal-to-noise ratio, and unbiased reconstructions.

  19. Standard and non-standard weak interactions

    International Nuclear Information System (INIS)

    Leurer, M.

    1985-12-01

    This work consists of independent chapters, all deal with weak interactions. The first chapter deals with left-right symmetric theories. Two main versions of these theories are discussed and compared. In addition, the K - K-bar mixing term is analysed: it has been known for several years now that in a left-right symmetric model there are new contributions to the mixing of kaons. We show that in the most appealing left-right symmetric model - the new contributions add up constructively. Consequently, we may derive reliable bounds on the mass of the right-handed gauge boson and the average mass of the (unavoidable) physical Higgs scalars. We also show that the new contributions are proportional to a new CP violating phase. While all previous treatments of the K - K-bar system were limited to the minimal model, we are able to show that our results hold also in the general case of nonminimal models. The second chapter deals with the possibility that W and Z are composite. Three experimental tests are discussed: (i) Universality -if W is composite then its coupling to the fermions is expected to deviate from universality. Since such deviations were not yet seen -we derive a lower bound on the compositeness scale. (ii) Possible enhancement of the reaction p-bar+p→Z 0 +γ+any - we show that if Z 0 is composite then the cross section for the above process might be considerably enhanced and this effect can be measured at CERN and Fermilab.(iii) The eeγ events of the 1983 run in CERN - we show that in contradiction to suggestions made in several papers, these events may not be explained by a composite-Z decaying through a scalar. In the last chapter we discuss the quark mixing angles

  20. Weak values in a classical theory with an epistemic restriction

    International Nuclear Information System (INIS)

    Karanjai, Angela; Cavalcanti, Eric G; Bartlett, Stephen D; Rudolph, Terry

    2015-01-01

    Weak measurement of a quantum system followed by postselection based on a subsequent strong measurement gives rise to a quantity called the weak value: a complex number for which the interpretation has long been debated. We analyse the procedure of weak measurement and postselection, and the interpretation of the associated weak value, using a theory of classical mechanics supplemented by an epistemic restriction that is known to be operationally equivalent to a subtheory of quantum mechanics. Both the real and imaginary components of the weak value appear as phase space displacements in the postselected expectation values of the measurement device's position and momentum distributions, and we recover the same displacements as in the quantum case by studying the corresponding evolution in our theory of classical mechanics with an epistemic restriction. By using this epistemically restricted theory, we gain insight into the appearance of the weak value as a result of the statistical effects of post selection, and this provides us with an operational interpretation of the weak value, both its real and imaginary parts. We find that the imaginary part of the weak value is a measure of how much postselection biases the mean phase space distribution for a given amount of measurement disturbance. All such biases proportional to the imaginary part of the weak value vanish in the limit where disturbance due to measurement goes to zero. Our analysis also offers intuitive insight into how measurement disturbance can be minimized and the limits of weak measurement. (paper)

  1. Effect of weak measurement on entanglement distribution over noisy channels.

    Science.gov (United States)

    Wang, Xin-Wen; Yu, Sixia; Zhang, Deng-Yu; Oh, C H

    2016-03-03

    Being able to implement effective entanglement distribution in noisy environments is a key step towards practical quantum communication, and long-term efforts have been made on the development of it. Recently, it has been found that the null-result weak measurement (NRWM) can be used to enhance probabilistically the entanglement of a single copy of amplitude-damped entangled state. This paper investigates remote distributions of bipartite and multipartite entangled states in the amplitudedamping environment by combining NRWMs and entanglement distillation protocols (EDPs). We show that the NRWM has no positive effect on the distribution of bipartite maximally entangled states and multipartite Greenberger-Horne-Zeilinger states, although it is able to increase the amount of entanglement of each source state (noisy entangled state) of EDPs with a certain probability. However, we find that the NRWM would contribute to remote distributions of multipartite W states. We demonstrate that the NRWM can not only reduce the fidelity thresholds for distillability of decohered W states, but also raise the distillation efficiencies of W states. Our results suggest a new idea for quantifying the ability of a local filtering operation in protecting entanglement from decoherence.

  2. Polaronic behavior in a weak-coupling superconductor.

    Science.gov (United States)

    Swartz, Adrian G; Inoue, Hisashi; Merz, Tyler A; Hikita, Yasuyuki; Raghu, Srinivas; Devereaux, Thomas P; Johnston, Steven; Hwang, Harold Y

    2018-02-13

    The nature of superconductivity in the dilute semiconductor SrTiO 3 has remained an open question for more than 50 y. The extremely low carrier densities ([Formula: see text]-[Formula: see text] cm -3 ) at which superconductivity occurs suggest an unconventional origin of superconductivity outside of the adiabatic limit on which the Bardeen-Cooper-Schrieffer (BCS) and Migdal-Eliashberg (ME) theories are based. We take advantage of a newly developed method for engineering band alignments at oxide interfaces and access the electronic structure of Nb-doped SrTiO 3 , using high-resolution tunneling spectroscopy. We observe strong coupling to the highest-energy longitudinal optic (LO) phonon branch and estimate the doping evolution of the dimensionless electron-phonon interaction strength ([Formula: see text]). Upon cooling below the superconducting transition temperature ([Formula: see text]), we observe a single superconducting gap corresponding to the weak-coupling limit of BCS theory, indicating an order of magnitude smaller coupling ([Formula: see text]). These results suggest that despite the strong normal state interaction with electrons, the highest LO phonon does not provide a dominant contribution to pairing. They further demonstrate that SrTiO 3 is an ideal system to probe superconductivity over a wide range of carrier density, adiabatic parameter, and electron-phonon coupling strength.

  3. Aluminum hydride cations stabilized by weakly coordinating carbaalanates.

    Science.gov (United States)

    Stasch, Andreas; Roesky, Herbert W; Noltemeyer, Mathias; Schmidt, Hans-Georg

    2005-08-08

    The reactions of t-BuCCLi with a mixture of AlH(3).NMe(3) and ClAlH(2).NMe(3) in boiling toluene with the addition of [t-BuCH(2)(Bzl)NMe(2)]Cl, or a bulky beta-diketimine instead, and [n-Bu(4)N]Cl led to the carbaalanates [H(2)Al(NMe(3))(2)](2)[(AlH)(8)(CCH(2)t-Bu)(6)], 3, and [n-Bu(4)N](2)[(AlH)(8)(CCH(2)t-Bu)(6)], 4, respectively. The reaction of Me(3)N.Al(CCt-Bu)(3) 5 and AlH(3).NMe(3) in boiling toluene yielded [H(n-Bu)Al(NMe(3))(2)][(AlH)(7)(AlNMe(3))(CCH(2)t-Bu)(6)], 6, in trace amounts. The single-crystal X-ray structures of 3 and 6 are reported. The compounds 3, 4, and 6 consist of well-separated ion pairs introducing carbaalanates as weakly coordinating anions and stabilizing aluminum hydride cations.

  4. Radiography of weakly ferromagnetic metals with polarized neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael; Calzada, Elbio; Muehlbauer, Martin; Schillinger, Burkhard [FRM II, Garching (Germany); E21, Physik Department TUM, Garching (Germany); Boeni, Peter; Neubauer, Andreas; Pfleiderer, Christian [E21, Physik Department TUM, Garching (Germany)

    2009-07-01

    The depolarization of a neutron beam passing through a ferromagnet crucially depends on the magnetic properties of the sample. Combining neutron depolarisation measurements with neutron radiography allows obtaining spatially resolved information about these properties. For measuring the depolarization, we have installed a longitudinal polarized beam setup at the ANTARES beamline consisting of {sup 3}He polarizers and flat coil spin flippers. With this setup we have performed radiography with polarized neutrons in the weak itinerant ferromagnets Pd{sub 1-x}Ni{sub x} in order to determine the spatial distribution of the Curie temperatures T{sub C} in the samples. The results show that the single crystals are rather inhomogeneous showing large variations in T{sub C}. The data allows firstly to cut out small crystals with improved homogeneity for neutron scattering experiments and secondly to provide feedback for improving the growth techniques for the crystals. In the future we hope to use the potential of this method to map out magnetic domains across large volume samples.

  5. Dynamically Weak Faults During Earthquakes (Invited)

    Science.gov (United States)

    di Toro, G.; Han, R.; Hirose, T.; de Paola, N.; Nielsen, S. B.; Mizoguchi, K.; Ferri, F.; Cocco, M.; Shimamoto, T.

    2009-12-01

    investigation suggest Wb to be mostly heat, the comparison between experimental and natural Wb indicates that the activation energies for individual processes governing dynamic fault weakening on experimental faults are similar to those governing on natural faults. 3) experimental faults and natural seismogenic faults contain strikingly similar materials (solidified melts, reaction products, fluidized gouges, etc.). We conclude that the experimental work performed in the last years indicates that faults are dynamically weak when they are deformed under normal stresses and slip rates typical of earthquakes, independently of the rock and weakening mechanism involved.

  6. Quenching of weak interactions in nucleon matter

    International Nuclear Information System (INIS)

    Cowell, S.; Pandharipande, V.R.

    2003-01-01

    We have calculated the one-body Fermi and Gamow-Teller charge-current and vector and axial-vector neutral-current nuclear matrix elements in nucleon matter at densities of 0.08, 0.16, and 0.24 fm -3 and proton fractions ranging from 0.2 to 0.5. The correlated states for nucleon matter are obtained by operating on Fermi-gas states by a symmetrized product of pair correlation operators determined from variational calculations with the Argonne-v18 and Urbana-IX two- and three-nucleon interactions. The squares of the charge- current matrix elements are found to be quenched by 20-25 % by the short-range correlations in nucleon matter. Most of the quenching is due to spin-isospin correlations induced by the pion exchange interactions which change the isospins and spins of the nucleons. A large part of it can be related to the probability for a spin-up proton quasiparticle to be a bare spin-up/down proton/neutron. Within the interval considered, the charge-current matrix elements do not have significant dependence on the matter density, proton fraction, and magnitudes of nucleon momenta; however, they do depend on momentum transfer. The neutral-current matrix elements have a significant dependence on the proton fraction. We also calculate the matrix elements of the nuclear Hamiltonian in the same correlated basis. These provide relatively mild effective interactions that give the variational energies in the Hartree-Fock approximation. The calculated two-nucleon effective interaction describes the spin-isospin susceptibilities of nuclear and neutron matter fairly accurately. However terms greater than or equal to three-body terms are necessary to reproduce the compressibility. Realistic calculations of weak interaction rates in nucleon matter can presumably be carried out using the effective operators and interactions studied here. All presented results use the simple two-body cluster approximation to calculate the correlated basis matrix elements. This allows for a clear

  7. Proximal Limb Weakness Reverting After CSF Diversion In Intracranial Hypertension

    Directory of Open Access Journals (Sweden)

    Sinha S

    2005-01-01

    Full Text Available We report about two young girls who developed progressive visual failure secondary to increased intracranial pressure and had significant proximal muscle weakness of limbs. Patients with elevated intracranial pressure (ICP may present with "false localizing signs", besides having headache, vomiting and papilledema. Radicular pain as a manifestation of raised ICP is rare and motor weakness attributable to polyradiculopathy is exceptional. Two patients with increased intracranial pressure without lateralizing signs′ had singnificant muscle weakness. Clinical evaluation and laboratory tests did not disclose any other cause for weakness. Following theco-peritoneal shunt, in both patients, there was variable recovery of vision but the proximal weakness and symptoms of elevated ICP improved rapidly. Recognition of this uncommon manifestation of raised ICP may obviate the need for unnecessary investigation and reduce morbidity due to weakness by CSF diversion procedure.

  8. Prospects for weak lensing studies with new radio telescopes

    OpenAIRE

    M. L. Brown

    2012-01-01

    I outline the prospects for performing weak lensing studies with the new generation of radio telescopes that are coming online now and in the future. I include a description of a proposed technique to use polarization observations in radio weak lensing analyses which could prove extremely useful for removing a contaminating signal from intrinsic alignments. Ultimately, the Square Kilometre Array promises to be an exceptional instrument for performing weak lensing studies due to the high resol...

  9. Transport equations in weak topologies of dual Banach spaces

    International Nuclear Information System (INIS)

    Greenberg, W.; Polewczak, J.

    1989-01-01

    Nonlinear transport equations are studied, in which the nonlinearity, arising from the collision operator, is well behaved in the weak topology of a weakly compactly generated Banach space. The Cauchy problem is posed for general semilinear evolution equations, which can model a variety of diffusion and kinetic equations. Local existence theorems are obtained for such spaces. In particular, the results are applicable to transport equations in L ∞ with appropriate weak (i.e., L 1 ) continuity properties

  10. Weak fault detection and health degradation monitoring using customized standard multiwavelets

    Science.gov (United States)

    Yuan, Jing; Wang, Yu; Peng, Yizhen; Wei, Chenjun

    2017-09-01

    Due to the nonobvious symptoms contaminated by a large amount of background noise, it is challenging to beforehand detect and predictively monitor the weak faults for machinery security assurance. Multiwavelets can act as adaptive non-stationary signal processing tools, potentially viable for weak fault diagnosis. However, the signal-based multiwavelets suffer from such problems as the imperfect properties missing the crucial orthogonality, the decomposition distortion impossibly reflecting the relationships between the faults and signatures, the single objective optimization and independence for fault prognostic. Thus, customized standard multiwavelets are proposed for weak fault detection and health degradation monitoring, especially the weak fault signature quantitative identification. First, the flexible standard multiwavelets are designed using the construction method derived from scalar wavelets, seizing the desired properties for accurate detection of weak faults and avoiding the distortion issue for feature quantitative identification. Second, the multi-objective optimization combined three dimensionless indicators of the normalized energy entropy, normalized singular entropy and kurtosis index is introduced to the evaluation criterions, and benefits for selecting the potential best basis functions for weak faults without the influence of the variable working condition. Third, an ensemble health indicator fused by the kurtosis index, impulse index and clearance index of the original signal along with the normalized energy entropy and normalized singular entropy by the customized standard multiwavelets is achieved using Mahalanobis distance to continuously monitor the health condition and track the performance degradation. Finally, three experimental case studies are implemented to demonstrate the feasibility and effectiveness of the proposed method. The results show that the proposed method can quantitatively identify the fault signature of a slight rub on

  11. Investigating weaknesses in Android certificate security

    Science.gov (United States)

    Krych, Daniel E.; Lange-Maney, Stephen; McDaniel, Patrick; Glodek, William

    2015-05-01

    Android's application market relies on secure certificate generation to establish trust between applications and their users; yet, cryptography is often not a priority for application developers and many fail to take the necessary security precautions. Indeed, there is cause for concern: several recent high-profile studies have observed a pervasive lack of entropy on Web-systems leading to the factorization of private keys.1 Sufficient entropy, or randomness, is essential to generate secure key pairs and combat predictable key generation. In this paper, we analyze the security of Android certificates. We investigate the entropy present in 550,000 Android application certificates using the Quasilinear GCD finding algorithm.1 Our results show that while the lack of entropy does not appear to be as ubiquitous in the mobile markets as on Web-systems, there is substantial reuse of certificates only one third of the certificates in our dataset were unique. In other words, we find that organizations frequently reuse certificates for different applications. While such a practice is acceptable under Google's specifications for a single developer, we find that in some cases the same certificates are used for a myriad of developers, potentially compromising Android's intended trust relationships. Further, we observed duplicate certificates being used by both malicious and non-malicious applications. The top 3 repeated certificates present in our dataset accounted for a total of 11,438 separate APKs. Of these applications, 451, or roughly 4%, were identified as malicious by antivirus services.

  12. Bunched soliton states in weakly coupled sine-Gordon systems

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Samuelsen, Mogens Rugholm; Lomdahl, P. S.

    1990-01-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results.......The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results....

  13. Some Viable Techniques for Assessing and Counselling Cognitive Processing Weakness

    Science.gov (United States)

    Haruna, Abubakar Sadiq

    2016-01-01

    Cognitive Processing weakness (CPW) is a psychological problem that impedes students' ability to learn effectively in a normal school setting. Such weakness may include; auditory, visual, conceptual, sequential, speed and attention processing. This paper therefore examines the basic assessment or diagnostic approaches such as Diagnosis by…

  14. On n-weak amenability of Rees semigroup algebras

    Indian Academy of Sciences (India)

    semigroups. In this work, we shall consider this class of Banach algebras. We examine the n-weak amenability of some semigroup algebras, and give an easier example of a Banach algebra which is n-weakly amenable if n is odd. Let L1(G) be the group algebra of a locally compact group G (§3.3 of [3]). Then Johnson.

  15. High-redshift SDSS Quasars with Weak Emission Lines

    DEFF Research Database (Denmark)

    Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Brandt, W. N.

    2009-01-01

    We identify a sample of 74 high-redshift quasars (z > 3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z > 4. These weak emission-line quasars (WLQs) constitute a promine...

  16. The Maslov index in weak symplectic functional analysis

    DEFF Research Database (Denmark)

    Booss-Bavnbek, Bernhelm; Zhu, Chaofeng

    2013-01-01

    We recall the Chernoff-Marsden definition of weak symplectic structure and give a rigorous treatment of the functional analysis and geometry of weak symplectic Banach spaces. We define the Maslov index of a continuous path of Fredholm pairs of Lagrangian subspaces in continuously varying Banach...... spaces. We derive basic properties of this Maslov index and emphasize the new features appearing....

  17. On weak exponential expansiveness of evolution families in Banach spaces.

    Science.gov (United States)

    Yue, Tian; Song, Xiao-qiu; Li, Dong-qing

    2013-01-01

    The aim of this paper is to give several characterizations for the property of weak exponential expansiveness for evolution families in Banach spaces. Variants for weak exponential expansiveness of some well-known results in stability theory (Datko (1973), Rolewicz (1986), Ichikawa (1984), and Megan et al. (2003)) are obtained.

  18. Can Weak Measurement Lend Empirical Support to Quantum Retrocausality?

    Directory of Open Access Journals (Sweden)

    Aharonov Yakir

    2013-09-01

    Full Text Available Quantum weak measurement is presented as shedding new light on the retrocausality question. It is shown to leave a system almost unaffected while gathering information about it. Next, an EPR experiment is studied where each particle undergoes a few weak measurements along some pre-set spin orientations. These weak outcomes are individually recorded. Then the particle undergoes a strong measurement along a spin orientation freely chosen at the last moment. Bell-inequality violation is expected between the two final strong measurements within each EPR pair. At the same time, agreement is expected between these strong measurements and the earlier weak ones performed on that pair. A contradiction thereby ensues: i Bell’s theorem forbids spin values to exist prior to the choice of the spin-orientation to be measured; ii A weak measurement cannot determine the outcome of a successive strong one; and iii Indeed no disentanglement is inflicted by the weak measurements; yet iv The weak measurements’ outcomes agree with those of the strong ones, suggesting the existence of pre-determined values. The most reasonable resolution seems to be that of the Two-State-Vector Formalism, namely, that the experimenter’s choice has been encrypted within the weak measurement’s outcomes, even before the experimenter themselves knows what their choice will be. Causal loops are avoided by this anticipation remaining encrypted until the final outcomes enable to decipher it.

  19. Secure Authentication from a Weak Key, Without Leaking Information

    NARCIS (Netherlands)

    N.J. Bouman (Niek); S. Fehr (Serge); K.G. Paterson (Kerry)

    2011-01-01

    htmlabstractWe study the problem of authentication based on a weak key in the information-theoretic setting. A key is weak if its min-entropy is an arbitrary small fraction of its bit length. This problem has recently received considerable attention, with different solutions optimizing different

  20. Measuring Workload Weak Resilience Signals at a Rail Control Post

    NARCIS (Netherlands)

    Siegel, A.W.; Schraagen, J.M.C.

    2014-01-01

    OCCUPATIONAL APPLICATIONS This article describes an observational study at a rail control post to measure workload weak resilience signals. A weak resilience signal indicates a possible degradation of a system's resilience, which is defined as the ability of a complex socio-technical system to cope

  1. Covenants with Weak Swords: ISO 14001 and Facilities' Environmental Performance

    Science.gov (United States)

    Potoski, Matthew; Prakash, Aseem

    2005-01-01

    Voluntary environmental programs are codes of progressive environmental conduct that firms pledge to adopt. This paper investigates whether ISO 14001, a voluntary program with a weak sword--a weak monitoring and sanctioning mechanism--can mitigate shirking and improve participants' environmental performance. Sponsored by the International…

  2. Introduction to unification of electromagnetic and weak interactions

    International Nuclear Information System (INIS)

    Martin, F.

    1980-01-01

    After reviewing the present status of weak interaction phenomenology we discuss the basic principles of gauge theories. Then we show how Higgs mechanism can give massive quanta of interaction. The so-called 'Weinberg-Salam' model, which unifies electromagnetic and weak interactions, is described. We conclude with a few words on unification with strong interactions and gravity [fr

  3. A young woman with weakness of the legs

    African Journals Online (AJOL)

    A previously well 22-year-old woman presented with progressive weakness of her legs and urinary incontinence over 7 days. Clinically she was healthy, with no skin rashes. On neurological examination she had profound bilateral weakness of the lower limbs, hypertonia, hyperreflexia, a positive Babinski sign and a T6 ...

  4. WEAK SOLVABILITY FOR A CLASS OF CONTACT PROBLEMS

    Directory of Open Access Journals (Sweden)

    Andaluzia Matei

    2010-07-01

    Full Text Available A unilateral frictionless contact model, under the small deformationshypothesis, for static processes is considered. We model the behaviorof the material by a constitutive law stated in a subdifferentialform. The contact is described with Signorini's condition. Our studyfocuses on the weak solvability of the model, based on a weak formulation with dual Lagrange multipliers

  5. Robust LHC Higgs Search in Weak Boson Fusion

    CERN Document Server

    Eboli, A A O; Rainwater, D L

    2004-01-01

    We demonstrate that an LHC Higgs search in weak boson fusion production with subsequent decay to weak boson pairs is robust against extensions of the Standard Model or MSSM involving a large number of Higgs doublets. We also show that the transverse mass distribution provides unambiguous discrimination of a continuum Higgs signal from the Standard Model.

  6. New limits on quark and lepton weak couplings

    International Nuclear Information System (INIS)

    Barnett, R.M.

    1978-06-01

    The unique determination of the weak neutral-current couplings of u and d quarks is discussed. Knowledge of these quark couplings has important implications for the determination of the electron's couplings. Recent data provide new restrictions on the charged-current couplings of quarks. The implications of these analyses for weak and electromagnetic gauge theories of quarks and leptons are examined

  7. Microwave-assisted Weak Acid Hydrolysis of Proteins

    Directory of Open Access Journals (Sweden)

    Miyeong Seo

    2012-06-01

    Full Text Available Myoglobin was hydrolyzed by microwave-assisted weak acid hydrolysis with 2% formic acid at 37 oC, 50 oC, and100 oC for 1 h. The most effective hydrolysis was observed at 100 oC. Hydrolysis products were investigated using matrixassistedlaser desorption/ionization time-of-flight mass spectrometry. Most cleavages predominantly occurred at the C-termini ofaspartyl residues. For comparison, weak acid hydrolysis was also performed in boiling water for 20, 40, 60, and 120 min. A 60-min weak acid hydrolysis in boiling water yielded similar results as a 60-min microwave-assisted weak acid hydrolysis at100 oC. These results strongly suggest that microwave irradiation has no notable enhancement effect on acid hydrolysis of proteinsand that temperature is the major factor that determines the effectiveness of weak acid hydrolysis.

  8. Polyaniline: Aniline oxidation with strong and weak oxidants under various acidity

    Energy Technology Data Exchange (ETDEWEB)

    Bláha, Michal, E-mail: blaha@imc.cas.cz [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic); Trchová, Miroslava; Bober, Patrycja; Morávková, Zuzana [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic); Prokeš, Jan [Charles University, Faculty of Mathematics and Physics, 180 00 Prague 8 (Czech Republic); Stejskal, Jaroslav [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6 (Czech Republic)

    2017-06-15

    Aniline was oxidized with three strong inorganic oxidants (ammonium peroxydisulfate, cerium(IV) sulfate, potassium dichromate), two weak inorganic oxidants (iron(III) chloride, silver nitrate), and one organic oxidant (p-benzoquinone) in aqueous solutions of methanesulfonic acid (MSA) of various concentration. Whereas oxidation of aniline with ammonium peroxydisulfate yielded high-molecular-weight conducting polyaniline (PANI) in the whole acidity range, the oxidation with cerium(IV) sulfate led also to a single product close to PANI with considerably lower molecular weight and lower conductivity. Potassium dichromate gave PANI only at high concentration of MSA. The use of iron(III) chloride yielded composite mixtures of PANI and low-molecular-weight aniline oligomers. The oxidation of aniline with silver nitrate led to composites of silver and an organic part, which was constituted either by aniline oligomers or conducting polyaniline or both. p-Benzoquinone as oxidant produced mainly aniline oligomers with poor conductivity and 2,5-dianilino-p-benzoquinone-like structure detected in FTIR and Raman spectra when oxidation proceeded with weak oxidants. A general model of oxidation with strong and weak oxidants was formulated. - Highlights: • Comparison of aniline oxidation with oxidants of different redox potential. • UV–vis, FTIR and Raman spectroscopies combined with size-exclusion chromatography. • The contents of polymer and oligomers were analyzed and discussed. • General model of aniline oxidation with strong and weak oxidants was formulated.

  9. Accumulation of weak optical signals and spectral memory in InSe single crystals

    International Nuclear Information System (INIS)

    Abdinov, A.Shj.; Babaeva, R.F.

    1995-01-01

    Dysprosium alloying effect on the electron and physico-chemical properties of InSe monocrystals is studied. Accumulation of low light signals and spectral or color memory is shown to be observed under certain conditions (temperature, content of admitted impurity, wave length and light intensity)

  10. Vortex phase diagram studies in the weakly pinned single crystals of ...

    Indian Academy of Sciences (India)

    The magnetisation hysteresis loops and the AC susceptibility measurements show pronounced peak effect as well as second magnetisation peak anomaly for both YNi2B2C and LuNi2B2C. Based on these results, a vortex phase diagram has been constructed for YNi2B2C for H ‖ c depicting different glassy phases of the ...

  11. Vortex phase diagram studies in the weakly pinned single crystals of ...

    Indian Academy of Sciences (India)

    flux line lattice symmetry have been reported in these systems via the small angle neutron scattering experiments. .... parable to the penetration depth value in the YNi2B2C system [20,36]. However, it is known that ..... 6 attest to the scaling behaviour operative for the pinning force as regards the PE phenomenon, and this is ...

  12. Local Weak Ferromagnetism in Single-Crystalline Ferroelectric BiFeO3

    DEFF Research Database (Denmark)

    Ramazanoglu, M.; Laver, Mark; Ratcliff, W.

    2011-01-01

    regions of dimension 0.03 microns along [11̅ 0], to several microns along [111], confirming a long-standing theoretical prediction. The average local magnetization is 0.06  μB/Fe. Our results provide an indication of the intrinsic macroscopic magnetization to be expected in ferroelectric BiFeO3 thin films...

  13. On the weakly nonlinear, transversal vibrations of a conveyor belt with a low and time-varying velocity

    NARCIS (Netherlands)

    Suweken, G.; van Horssen, W.T.

    2002-01-01

    In this paper the weakly nonlinear, transversal vibrations of a conveyor belt will be considered. The belt is assumed to move with a low and time-varying speed. Using Kirchhoff's approach a single equation of motion will be derived from a coupled system of partial differential equations describing

  14. Visualization of weak interactions between quantum dot and graphene in hybrid materials.

    Science.gov (United States)

    Cao, Shuo; Wang, Jingang; Ding, Yong; Sun, Mengtao; Ma, Fengcai

    2017-03-24

    The mechanisms of the weak interactions within hybrid materials such as quantum dot (QD) and graphene (GR) have important implications for the design of related optoelectronic devices. We characterize the weak interactions in hybrid QD-GR systems using a non-covalent interactions approach. For a single Cd 13 Se 13 QD with a core-cage structure, the intensity of the steric repulsive strain in every Cd-Se spatial four-atom ring of the cage surface is stronger than that of the inter-core-cage structure. Van der Waals (vdW) interactions occur within the cavity of the cage and within the six-atom rings of the cage surface. The spatial repulsion strain and attractive interactions play a key role in stabilizing the structure of the monolayer graphene. Interestingly, the spatial six-atom ring of the single QD change into spatial four-atom rings of the QD in the hybrid system, accompanied by the translation of vdW interactions into steric repulsive interactions. We conclude that the vdW interactions with π extensions and the weak attractive interactions within local areas between the QD and graphene together stabilize the integral structure of the hybrid QD-GR system. These results explain of the formation mechanism and the stabilization of the components in QD-GR hybrid materials.

  15. Intensive care unit-acquired weakness in the burn population.

    Science.gov (United States)

    Cubitt, Jonathan J; Davies, Menna; Lye, George; Evans, Janine; Combellack, Tom; Dickson, William; Nguyen, Dai Q

    2016-05-01

    Intensive care unit-acquired weakness is an evolving problem in the burn population. As patients are surviving injuries that previously would have been fatal, the focus of treatment is shifting from survival to long-term outcome. The rehabilitation of burn patients can be challenging; however, a certain subgroup of patients have worse outcomes than others. These patients may suffer from intensive care unit-acquired weakness, and their treatment, physiotherapy and expectations need to be adjusted accordingly. This study investigates the condition of intensive care unit-acquired weakness in our burn centre. We conducted a retrospective analysis of all the admissions to our burn centre between 2008 and 2012 and identified 22 patients who suffered from intensive care unit-acquired weakness. These patients were significantly younger with significantly larger burns than those without intensive care unit-acquired weakness. The known risk factors for intensive care unit-acquired weakness are commonplace in the burn population. The recovery of these patients is significantly affected by their weakness. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. Prevalence of Weak D Antigen In Western Indian Population

    Directory of Open Access Journals (Sweden)

    Tanvi Sadaria

    2015-12-01

    Full Text Available Introduction: Discovery of Rh antigens in 1939 by Landsteiner and Weiner was the revolutionary stage in blood banking. Of these antigens, D, which decides Rh positivity or negativity, is the most antigenic. A problem is encountered when an individual has a weakened expression of D (Du, i.e., fewer numbers of D antigens on red cell membrane. Aims and Objectives: To know the prevalence of weak D in Indian population because incidence varies in different population. To determine the risk of alloimmunization among Rh D negative patients who receives the blood of weak D positive donors. Material and Methods: Rh grouping of 38,962 donors who came to The Department of Immunohematology and Blood Transfusion of Civil Hospital, Ahmedabad from 1st January 2013 to 30th September 2014 was done using the DIAGAST (Automated Grouping. The samples that tested negative for D antigen were further analysed for weak D (Du by indirect antiglobulin test using blend of Ig G and Ig M Anti D. This was done using Column agglutination method in ID card (gel card. Results: The total number of donors studied was 38,962. Out of these 3360(8.6% were tested Rh D negative. All Rh D negative donors were tested for weak D (Du. 22 (0.056% of total donors and 0.65% of Rh negative donors turned out to be weak D (Du positive. Conclusion: The prevalence of weak D (Du in Western Indian population is 0.056 %, So the risk of alloimmunization in our setting due to weak D (Du antigen is marginal. But, testing of weak D antigen is necessary in blood bank because weak D antigen is immunogenic and can produce alloimmunization if transfused to Rh D negative subjects.

  17. Weak Localisation in Clean and Highly Disordered Graphene

    International Nuclear Information System (INIS)

    Hilke, Michael; Massicotte, Mathieu; Whiteway, Eric; Yu, Victor

    2013-01-01

    We look at the magnetic field induced weak localisation peak of graphene samples with different mobilities. At very low temperatures, low mobility samples exhibit a very broad peak as a function of the magnetic field, in contrast to higher mobility samples, where the weak localisation peak is very sharp. We analyze the experimental data in the context of the localisation length, which allows us to extract, both the localisation length and the phase coherence length of the samples, regardless of their mobilities. This analysis is made possible by the observation that the localisation length undergoes a generic weak localisation dependence with striking universal properties

  18. The quantum to classical crossover for a weak link capacitor

    International Nuclear Information System (INIS)

    Spiller, T.P.; Clark, T.D.; Prance, H.; Prance, R.J.

    1995-01-01

    We consider a model weak link, an ultra-small capacitor subject to tunnelling, to ohmic dissipation and fed with an external displacement current. The framework we employ is the new approach of quantum state diffusion, which treats individual open quantum systems as well as being able to generate the conventional ensemble averages. We show how evidence, for archetypal quantum behaviour (coherent oscillations) and archetypal classical behaviour (chaos) arises, for weak links whose parameters are related by a rather modest scaling. Interestingly, the quantum behaviour can arise for a weak link with intrinsic parameter values such that it could exhibit chaos, if it were a purely classical device

  19. Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

    DEFF Research Database (Denmark)

    Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A

    2002-01-01

    as well as specific complexes of modified glycopeptide antibiotics with their target peptide. The weak nature of bonding is substantiated by blackbody infrared dissociation, low-energy collisional excitation and force-field simulations. The results are consistent with a non-ergodic ECD cleavage mechanism.......We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers...

  20. Testing the weak gravity-cosmic censorship connection

    Science.gov (United States)

    Crisford, Toby; Horowitz, Gary T.; Santos, Jorge E.

    2018-03-01

    A surprising connection between the weak gravity conjecture and cosmic censorship has recently been proposed. In particular, it was argued that a promising class of counterexamples to cosmic censorship in four-dimensional Einstein-Maxwell-Λ theory would be removed if charged particles (with sufficient charge) were present. We test this idea and find that indeed if the weak gravity conjecture is true, one cannot violate cosmic censorship this way. Remarkably, the minimum value of charge required to preserve cosmic censorship appears to agree precisely with that proposed by the weak gravity conjecture.

  1. Nonperturbative theory of weak pre- and post-selected measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, Abraham G., E-mail: kofmana@gmail.com; Ashhab, Sahel; Nori, Franco

    2012-11-01

    This paper starts with a brief review of the topic of strong and weak pre- and post-selected (PPS) quantum measurements, as well as weak values, and afterwards presents original work. In particular, we develop a nonperturbative theory of weak PPS measurements of an arbitrary system with an arbitrary meter, for arbitrary initial states of the system and the meter. New and simple analytical formulas are obtained for the average and the distribution of the meter pointer variable. These formulas hold to all orders in the weak value. In the case of a mixed preselected state, in addition to the standard weak value, an associated weak value is required to describe weak PPS measurements. In the linear regime, the theory provides the generalized Aharonov–Albert–Vaidman formula. Moreover, we reveal two new regimes of weak PPS measurements: the strongly-nonlinear regime and the inverted region (the regime with a very large weak value), where the system-dependent contribution to the pointer deflection decreases with increasing the measurement strength. The optimal conditions for weak PPS measurements are obtained in the strongly-nonlinear regime, where the magnitude of the average pointer deflection is equal or close to the maximum. This maximum is independent of the measurement strength, being typically of the order of the pointer uncertainty. In the optimal regime, the small parameter of the theory is comparable to the overlap of the pre- and post-selected states. We show that the amplification coefficient in the weak PPS measurements is generally a product of two qualitatively different factors. The effects of the free system and meter Hamiltonians are discussed. We also estimate the size of the ensemble required for a measurement and identify optimal and efficient meters for weak measurements. Exact solutions are obtained for a certain class of the measured observables. These solutions are used for numerical calculations, the results of which agree with the theory

  2. Practical advantages of almost-balanced-weak-value metrological techniques

    Science.gov (United States)

    Martínez-Rincón, Julián; Chen, Zekai; Howell, John C.

    2017-06-01

    Precision measurements of ultrasmall linear velocities of one of the mirrors in a Michelson interferometer are performed using two different weak-value techniques. We show that the technique of almost-balanced weak values (ABWV) offers practical advantages over the technique of weak-value amplification, resulting in larger signal-to-noise ratios and the possibility of longer integration times due to robustness to slow drifts. As an example of the performance of the ABWV protocol we report a velocity sensitivity of 60 fm/s after 40 h of integration time. The sensitivity of the Doppler shift due to the moving mirror is 150 nHz.

  3. Description of meson strong weak and electromagnetic interactions in quantum chiral theory

    International Nuclear Information System (INIS)

    Volkov, M.K.; Ehbert, D.

    1979-01-01

    The picture of all the principal meson decays of the basic octet has been obtained in the framework of the SU(3)xSU(3) symmetric chiral model of the field theory. An attempt is made to generalize the nonlinear chiral model for the case of charmed hadrons, i.e., a transition from the SU(3)xSU(3) group to the SU(4)xSU(4) group. The authors have succeeded in elucidating unambiguously the role of the Kabibbo angle both in weak and strong interactions (it defines the structure of weak hadron currents and hadron mass splitting in isotopic multiplets). Proceeding from decays of the basic octet mesons it has been shown that the nonlinear chiral SU(3)xSU(3) symmetric theory may be considered as the quantum field theory, which satisfactorily describes the low-energy meson physics in two first orders of the perturbation theory (tree and single-loop approximations)

  4. Compressive strength of brick masonry made with weak mortars

    DEFF Research Database (Denmark)

    Pedersen, Erik Steen; Hansen, Klavs Feilberg

    2013-01-01

    in the joint will ensure a certain level of load-carrying capacity. This is due to the interaction between compression in the weak mortar and tension in the adjacent bricks. This paper proposes an expression for the compressive strength of masonry made with weak lime mortars (fm... (fm≈6 N/mm2) compression tests of masonry with perforated bricks show that the EC6 expression is not always safe for Danish masonry. This is probably because the tensile strength of the bricks also has an effect on the compressive strength of masonry when the mortar is stronger than weak lime mortar......The use of weak mortar has a number of advantages (e.g. prevention of expansion joints, environmental issues). However, according to EC6, the strength of masonry vanishes when the compressive strength of the mortar approaches zero. In reality the presence of even unhardened mortar kept in place...

  5. Informal Institutions and the "Weaknesses" of Human Behavior

    National Research Council Canada - National Science Library

    Goebel, Markus; Thomas, Tobias

    2005-01-01

    ... to interpersonal consistency and interpersonal conformity here. These sources of a systematic deviation from the standard model of the homo oeconomicus result in systematic weaknesses of perception and deviations of behavior...

  6. Qweak: A Precision Measurement of the Proton's Weak Charge

    International Nuclear Information System (INIS)

    David Armstrong; Todd Averett; James Birchall; James Bowman; Roger Carlini; Swapan Chattopadhyay; Charles Davis; J. Doornbos; James Dunne; Rolf Ent; Jens Erler; Willie Falk; John Finn; Tony Forest; David Gaskell; Klaus Grimm; C. Hagner; F. Hersman; Maurik Holtrop; Kathleen Johnston; R.T. Jones; Kyungseon Joo; Cynthia Keppel; Elie Korkmaz; Stanley Kowalski; Lawrence Lee; Allison Lung; David Mack; Stanislaw Majewski; Gregory Mitchell; Hamlet Mkrtchyan; Norman Morgan; Allena Opper; Shelley Page; Seppo Penttila; Mark Pitt; Benard Poelker; Tracy Porcelli; William Ramsay; Michael Ramsey-musolf; Julie Roche; Neven Simicevic; Gregory Smith; Riad Suleiman; Simon Taylor; Willem Van Oers; Steven Wells; W.S. Wilburn; Stephen Wood; Carl Zorn

    2004-01-01

    The Qweak experiment at Jefferson Lab aims to make a 4% measurement of the parity-violating asymmetry in elastic scattering at very low Q 2 of a longitudinally polarized electron beam on a proton target. The experiment will measure the weak charge of the proton, and thus the weak mixing angle at low energy scale, providing a precision test of the Standard Model. Since the value of the weak mixing angle is approximately 1/4, the weak charge of the proton Q w p = 1-4 sin 2 θ w is suppressed in the Standard Model, making it especially sensitive to the value of the mixing angle and also to possible new physics. The experiment is approved to run at JLab, and the construction plan calls for the hardware to be ready to install in Hall C in 2007. The theoretical context of the experiment and the status of its design are discussed

  7. Existence of Weak Solutions for a Nonlinear Elliptic System

    Directory of Open Access Journals (Sweden)

    Gilbert RobertP

    2009-01-01

    Full Text Available We investigate the existence of weak solutions to the following Dirichlet boundary value problem, which occurs when modeling an injection molding process with a partial slip condition on the boundary. We have in ; in ; , and on .

  8. Undecidability of Weak Bisimilarity for PA-Processes

    DEFF Research Database (Denmark)

    Srba, Jiri

    2003-01-01

    We prove that the problem whether two PA-processes are weakly bisimilar is undecidable. We combine several proof techniques to provide a reduction from Post's correspondence problem to our problem: existential quantification technique, masking technique and deadlock elimination technique....

  9. National Transportation Safety Board : weak internal control impaired financial accountability

    Science.gov (United States)

    2001-09-28

    The U. S. General Accounting Office (GAO) was asked to review the National Transportation Safety Board's (NTSB) internal controls over selected types of fiscal year expenditures. They were asked to determine whether internal control weaknesses were a...

  10. Notification: FY 2018 CSB Management Challenges and Internal Control Weaknesses

    Science.gov (United States)

    December 26, 2017. The OIG is beginning work to update for fiscal year 2018 its list of proposed key management challenges and internal control weaknesses confronting the U.S. Chemical Safety and Hazard Investigation Board (CSB).

  11. A weakly compressible formulation for modelling liquid-gas sloshing

    CSIR Research Space (South Africa)

    Heyns, Johan A

    2012-09-01

    Full Text Available , the implementation of a weakly compressible formulation which accounts for variations in the gas density is presented. With the aim of ensuring a computational efficient implementation of the proposed formulation, an implicit iterative GMRES solver with LU...

  12. Rh Immunoprophylaxis for Women With a Serologic Weak D Phenotype.

    Science.gov (United States)

    Virk, Mrigender; Sandler, S Gerald

    2015-01-01

    It is standard practice for pregnant RhD-negative women who have not already formed anti-D to receive antepartum Rh immunoprophylaxis and, if they deliver an RhD-positive neonate, to receive postpartum Rh immunoprophylaxis. An estimated 0.6% to 1.0% of white women have red blood cells that express a serologic weak D phenotype. Of these women, approximately 80% will have a weak D type 1, 2, or 3 that could be managed safely as RhD-positive. Surveys of laboratory practice reveal a lack of standards for interpreting the RhD type for women with a serologic weak D and for determining their need for Rh immunoprophylaxis. RhD genotyping is recommended to determine the molecular basis of serologic weak D phenotypes in pregnant women as a basis for determining their candidacy for Rh immunoprophylaxis.

  13. Weak signal detection: A discrete window of opportunity for ...

    African Journals Online (AJOL)

    weak signal detection' as a potential opportunity to fill this void. Method: Combining futures and complexity theory, we reflect on two pilot case studies that involved the Archetype Extraction technique and the SenseMakerw CollectorTM tool.

  14. Strengths only or strengths and relative weaknesses? A preliminary study.

    Science.gov (United States)

    Rust, Teri; Diessner, Rhett; Reade, Lindsay

    2009-10-01

    Does working on developing character strengths and relative character weaknesses cause lower life satisfaction than working on developing character strengths only? The present study provides a preliminary answer. After 76 college students completed the Values in Action Inventory of Strengths (C. Peterson & M. E. P. Seligman, 2004), the authors randomly assigned them to work on 2 character strengths or on 1 character strength and 1 relative weakness. Combined, these groups showed significant gains on the Satisfaction With Life Scale (E. Diener, R. A. Emmons, R. J. Larsen, & S. Griffin, 1985), compared with a 32-student no-treatment group. However, there was no significant difference in gain scores between the 2-strengths group and the 1-character-strength-and-1-relative-character-weakness group. The authors discuss how focusing on relative character weaknesses (along with strengths) does not diminish-and may assist in increasing-life satisfaction.

  15. Computing weakly reversible realizations of chemical reaction networks

    OpenAIRE

    Szederkenyi, Gabor; Hangos, Katalin M.; Tuza, Zsolt

    2011-01-01

    An algorithm is given in this paper for the computation of dynamically equivalent weakly reversible realizations with the maximal number of reactions, for chemical reaction networks (CRNs) with mass action kinetics.

  16. A weak magnetic field inhibits hippocampal neurogenesis in SD rats

    Science.gov (United States)

    Zhang, B.; Tian, L.; Cai, Y.; Pan, Y.

    2017-12-01

    Geomagnetic field is an important barrier that protects life forms on Earth from solar wind and radiation. Paleomagnetic data have well demonstrated that the strength of ancient geomagnetic field was dramatically weakened during a polarity transition. Accumulating evidence has shown that weak magnetic field exposures has serious adverse effects on the metabolism and behaviors in organisms. Hippocampal neurogenesis occurs throughout life in mammals' brains which plays a key role in brain function, and can be influenced by animals' age as well as environmental factors, but few studies have examined the response of hippocampal neurogenesis to it. In the present study, we have investigated the weak magnetic field effects on hippocampal neurogenesis of adult Sprague Dawley (SD) rats. Two types of magnetic fields were used, a weak magnetic field (≤1.3 μT) and the geomagnetic fields (51 μT).The latter is treated as a control condition. SD rats were exposure to the weak magnetic field up to 6 weeks. We measured the changes of newborn nerve cells' proliferation and survival, immature neurons, neurons and apoptosis in the dentate gyrus (DG) of hippocampus in SD rats. Results showed that, the weak magnetic field (≤1.3 μT) inhibited their neural stem cells proliferation and significantly reduced the survival of newborn nerve cells, immature neurons and neurons after 2 or 4 weeks continuous treatment (i.e. exposure to weak magnetic field). Moreover, apoptosis tests indicated the weak magnetic field can promote apoptosis of nerve cells in the hippocampus after 4 weeks treatment. Together, our new data indicate that weak magnetic field decrease adult hippocampal neurogenesis through inhibiting neural stem cells proliferation and promoting apoptosis, which provides useful experimental constraints on better understanding the mechanism of linkage between life and geomagnetic field.

  17. Chiral realization of the non-leptonic weak interactions

    International Nuclear Information System (INIS)

    Ecker, G.

    1990-01-01

    After a short introduction to chiral perturbation theory an attempt to relate the strong and the non-leptonic weak low-energy constants is reviewed. The weak deformation model is stimulated both by the geometrical structure of chiral perturbation theory and by phenomenological considerations. Applications to the radiative decays K → πγγ and K L → γe + e - are discussed. (Author) 38 refs., 4 figs

  18. Dissociation of weak acids during Gran plot free acidity titrations

    OpenAIRE

    Lindberg, Steven E:; Cole, Jan M.

    2011-01-01

    A comparison of weak and free acid concentrations measured by base titration and hydrogen ionactivities determined by direct pH measurement is described for several of our data sets for raincollected above and below a forest canopy in the eastern United States. These data illustrate theinfluence of weak acid dissociation during titration and the possible effect of activity coefficientson calculated free acid concentrations.DOI: 10.1111/j.1600-0889.1984.tb00240.x

  19. A connection between the strong and weak interactions

    International Nuclear Information System (INIS)

    Treiman, S.B.

    1989-01-01

    By studying weak scattering reactions (such as pion-nucleon scattering), the author and his colleague Marvin L Goldberger became renowned in the 1950s for work on dispersion relations. As a result of their collaboration a remarkable and unexpected connection was found between strong and weak interaction quantities. Agreement with experiment was good. Work by others found the same result, but via the partially conserved axial reactor current relation between the axial current divergence and the canonical pion field. (UK)

  20. What is behind the weakness in global investment?

    OpenAIRE

    Leboeuf, Maxime; Fay, Bob

    2016-01-01

    The recovery in private business investment globally remains extremely weak more than seven years after the financial crisis. This paper contributes to the ongoing policy debate on the factors behind this weakness by analyzing the role of growth prospects and uncertainty in explaining developments in non-residential private business investment in large advanced economies since the crisis. Augmenting the traditional models of investment with measures of growth expectations for output and uncer...

  1. On weak solutions of stochastic differential equations II

    Czech Academy of Sciences Publication Activity Database

    Hofmanová, Martina; Seidler, Jan

    2013-01-01

    Roč. 31, č. 4 (2013), s. 663-670 ISSN 0736-2994 R&D Projects: GA ČR GAP201/10/0752 Institutional support: RVO:67985556 Keywords : fractional integrals * stochastic differential equations * weak solutions Subject RIV: BA - General Mathematics Impact factor: 0.664, year: 2013 http://library.utia.cas.cz/separaty/2013/SI/hofmanova-on weak solutions of stochastic differential equations II.pdf

  2. Sequential weak continuity of null Lagrangians at the boundary

    Czech Academy of Sciences Publication Activity Database

    Kalamajska, A.; Kraemer, S.; Kružík, Martin

    2014-01-01

    Roč. 49, 3/4 (2014), s. 1263-1278 ISSN 0944-2669 R&D Projects: GA ČR GAP201/10/0357 Institutional support: RVO:67985556 Keywords : null Lagrangians * nonhomogeneous nonlinear mappings * sequential weak/in measure continuity Subject RIV: BA - General Mathematics Impact factor: 1.518, year: 2014 http://library.utia.cas.cz/separaty/2013/MTR/kruzik-sequential weak continuity of null lagrangians at the boundary.pdf

  3. Weak compactness and sigma-Asplund generated Banach spaces

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marián; Montesinos, V.; Zizler, Václav

    2007-01-01

    Roč. 181, č. 2 (2007), s. 125-152 ISSN 0039-3223 R&D Projects: GA AV ČR IAA1019301; GA AV ČR(CZ) IAA100190610 Institutional research plan: CEZ:AV0Z10190503 Keywords : epsilon-Asplund set * epsilon-weakly compact set * weakly compactly generated Banach space Subject RIV: BA - General Mathematics Impact factor: 0.568, year: 2007

  4. Classical and Weak Solutions for Two Models in Mathematical Finance

    Science.gov (United States)

    Gyulov, Tihomir B.; Valkov, Radoslav L.

    2011-12-01

    We study two mathematical models, arising in financial mathematics. These models are one-dimensional analogues of the famous Black-Scholes equation on finite interval. The main difficulty is the degeneration at the both ends of the space interval. First, classical solutions are studied. Positivity and convexity properties of the solutions are discussed. Variational formulation in weighted Sobolev spaces is introduced and existence and uniqueness of the weak solution is proved. Maximum principle for weak solution is discussed.

  5. Temporal evolution of crack propagation propensity in snow in relation to slab and weak layer properties

    Science.gov (United States)

    Schweizer, Jürg; Reuter, Benjamin; van Herwijnen, Alec; Richter, Bettina; Gaume, Johan

    2016-11-01

    If a weak snow layer below a cohesive slab is present in the snow cover, unstable snow conditions can prevail for days or even weeks. We monitored the temporal evolution of a weak layer of faceted crystals as well as the overlaying slab layers at the location of an automatic weather station in the Steintälli field site above Davos (Eastern Swiss Alps). We focussed on the crack propagation propensity and performed propagation saw tests (PSTs) on 7 sampling days during a 2-month period from early January to early March 2015. Based on video images taken during the tests we determined the mechanical properties of the slab and the weak layer and compared them to the results derived from concurrently performed measurements of penetration resistance using the snow micro-penetrometer (SMP). The critical cut length, observed in PSTs, increased overall during the measurement period. The increase was not steady and the lowest values of critical cut length were observed around the middle of the measurement period. The relevant mechanical properties, the slab effective elastic modulus and the weak layer specific fracture, overall increased as well. However, the changes with time differed, suggesting that the critical cut length cannot be assessed by simply monitoring a single mechanical property such as slab load, slab modulus or weak layer specific fracture energy. Instead, crack propagation propensity is the result of a complex interplay between the mechanical properties of the slab and the weak layer. We then compared our field observations to newly developed metrics of snow instability related to either failure initiation or crack propagation propensity. The metrics were either derived from the SMP signal or calculated from simulated snow stratigraphy (SNOWPACK). They partially reproduced the observed temporal evolution of critical cut length and instability test scores. Whereas our unique dataset of quantitative measures of snow instability provides new insights into the

  6. Transition from weak wave turbulence regime to solitonic regime

    Science.gov (United States)

    Hassani, Roumaissa; Mordant, Nicolas

    2017-11-01

    The Weak Turbulence Theory (WTT) is a statistical theory describing the interaction of a large ensemble of random waves characterized by very different length scales. For both weak non-linearity and weak dispersion a different regime is predicted where solitons propagate while keeping their shape unchanged. The question under investigation here is which regime between weak turbulence or soliton gas does the system choose ? We report an experimental investigation of wave turbulence at the surface of finite depth water in the gravity-capillary range. We tune the wave dispersion and the level of nonlinearity by modifying the depth of water and the forcing respectively. We use space-time resolved profilometry to reconstruct the deformed surface of water. When decreasing the water depth, we observe a drastic transition between weak turbulence at the weakest forcing and a solitonic regime at stronger forcing. We characterize the transition between both states by studying their Fourier Spectra. We also study the efficiency of energy transfer in the weak turbulence regime. We report a loss of efficiency of angular transfer as the dispersion of the wave is reduced until the system bifurcates into the solitonic regime. This project has recieved funding from the European Research Council (ERC, Grant Agreement No. 647018-WATU).

  7. On (weakly precious rings associated to central polynomials

    Directory of Open Access Journals (Sweden)

    Hani A. Khashan

    2018-04-01

    Full Text Available Let R be an associative ring with identity and let g(x be a fixed polynomial over the center of R. We define R to be (weakly g(x-precious if for every element a∈R, there are a zero s of g(x, a unit u and a nilpotent b such that (a=±s+u+b a=s+u+b. In this paper, we investigate many examples and properties of (weakly g(x-precious rings. If a and b are in the center of R with b-a is a unit, we give a characterizations for (weakly (x-a(x-b-precious rings in terms of (weakly precious rings. In particular, we prove that if 2 is a unit, then a ring is precious if and only it is weakly precious. Finally, for n∈ℕ, we study (weakly (xⁿ-x-precious rings and clarify some of their properties.

  8. Relative entropies, suitable weak solutions, and weak-strong uniqueness for the compressible Navier–Stokes system

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Jin, B.J.; Novotný, A.

    2012-01-01

    Roč. 14, č. 4 (2012), s. 717-730 ISSN 1422-6928 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : suitable weak solution * weak-strong uniqueness * compressible Navier-Stokes system Subject RIV: BA - General Mathematics Impact factor: 1.415, year: 2012 http://link.springer.com/article/10.1007%2Fs00021-011-0091-9

  9. Practical approach to the patient with acute neuromuscular weakness.

    Science.gov (United States)

    Nayak, Rajeev

    2017-07-16

    Acute neuromuscular paralysis (ANMP) is a clinical syndrome characterized by rapid onset muscle weakness progressing to maximum severity within several days to weeks (less than 4 wk). Bulbar and respiratory muscle weakness may or may not be present. It is a common neurological emergency which requires immediate and careful investigations to determine the etiology because accurate diagnosis has significant impact on therapy and prognosis. Respiratory failure caused by neuromuscular weakness is considered as more critical than lung disease because its development may be insidious or subtle until sudden decompensation leads to life threatening hypoxia. Also, the arterial blood gas finding of severe hypoxemia, hypercapnia, and acidosis may not be apparent until respiratory failure is profound. Hence, the requirement for respiratory assistance should also be intensively and promptly investigated in all patients with neuromuscular disease. The disorder is classified based on the site of defect in motor unit pathway, i.e ., anterior horn cells, nerve root, peripheral nerve, neuromuscular junction or muscle. Identification of the cause is primarily based on a good medical history and detailed clinical examination supplemented with neurophysiologic investigations and sometimes few specific laboratory tests. Medical history and neurological examination should be focused on the onset, progression, pattern and severity of muscle weakness as well as cranial nerves testing and tests for autonomic dysfunction. Associated non neurological features like fever, rash or other skin lesions etc. should also be noted. Globally, Guillain-Barré syndrome is the most frequent cause of ANMP and accounts for the majority of cases of respiratory muscles weakness associated with neuromuscular disorders. Newly acquired neuromuscular weakness in intensive care unit patients consist of critical illness polyneuropathy, critical illness myopathy and drug induced neuromuscular weakness which may

  10. Uniaxial negative thermal expansion facilitated by weak host-guest interactions.

    Science.gov (United States)

    Engel, Emile R; Smith, Vincent J; Bezuidenhout, Charl X; Barbour, Leonard J

    2014-04-25

    A nitromethane solvate of 18-crown-6 was investigated by means of variable-temperature single-crystal X-ray diffraction in response to a report of abnormal unit cell contraction. Exceptionally large positive thermal expansion in two axial directions and negative thermal expansion along the third was confirmed. The underlying mechanism relies exclusively on weak electrostatic interactions to yield a linear thermal expansion coefficient of -129 × 10(-6) K(-1), the largest negative value yet observed for an organic inclusion compound.

  11. Splitting and acquiring quantum information with perfect W states based on weak cross-Kerr nonlinearities

    Science.gov (United States)

    Xiu, Xiao-Ming; Cui, Cen; Lin, Yan-Fang; Dong, Li; Dong, Hai-Kuan; Gao, Ya-Jun

    2018-01-01

    With the assistance of weak cross-Kerr nonlinear interaction between photons and coherent states via Kerr media, we propose a scheme to split and acquire quantum information with three-photon perfect W states. By means of a fault-tolerant circuit, the perfect W states are distributed to the participants without being affected by the collective noise. And on this basis we present a scheme for splitting and acquiring a single-photon state with the shared perfect W states. Together with the mature techniques of classical feed-forward, simple and available linear optical elements are applied in the procedure, afford enhancing the feasibility of the theoretical scheme proposed here.

  12. A single particle energies

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R. [Illinois Univ., Chicago, IL (United States). Dept. of Physics]|[Argonne National Lab., IL (United States); Usmani, Q.N.; Sami, M. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics

    1993-09-01

    We consider the binding energies of {Lambda} hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A {le} 89 and for orbital angular momenta {ell}{sub {Lambda}} {le} 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei {sub {Lambda}}{sup A}Z with baryon number A in which a single {Lambda} hyperon (baryon number = 1) is bound to an ordinary nucleus {sup A}Z consisting of A - 1 nucleons = Z protons + N neutrons. The {Lambda} hyperon is neutral, has spin 1/2, strangeness S = {minus}1, isospin I = O and a mass M{sub {Lambda}} = 1116 MeV/c{sup 2}. Although the {Lambda} interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V{sub {Lambda}N} {approx} 0.5 V{sub NN}. As a result, the two-body {Lambda}N system is unbound, and the lightest bound HN is the three-body hypertriton {sub {Lambda}}{sup 3}H in which the {Lambda} is bound to a deuteron with the {Lambda}-d separation energy being only {approx} 0.1 MeV corresponding to an exponential tail of radius {approx} 15 fm! In strong interactions the strangeness S is of course conserved, and the {Lambda} is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the {Lambda} which can decay either via ``free`` pionic decay {Lambda} {yields} N + {pi} or via induced decay {Lambda} + N {yields} N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime {approx} 10{sup {minus}10}s is in fact close to the lifetime of a free {Lambda}. Since this is much longer than the strong interaction time {approx} 10{sup {minus}22}s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei.

  13. A single particle energies

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.; Sami, M.

    1993-01-01

    We consider the binding energies of Λ hypernuclei (HN), in particular the single-particle (s.p.) energy data, which have been obtained for a wide range of HN with mass numbers A ≤ 89 and for orbital angular momenta ell Λ ≤ 4. We briefly review some of the relevant properties of A hypernuclei. These are nuclei Λ A Z with baryon number A in which a single Λ hyperon (baryon number = 1) is bound to an ordinary nucleus A Z consisting of A - 1 nucleons = Z protons + N neutrons. The Λ hyperon is neutral, has spin 1/2, strangeness S = -1, isospin I = O and a mass M Λ = 1116 MeV/c 2 . Although the Λ interacts with a nucleon, its interaction is only about half as strong as that between two nucleons, and thus very roughly V ΛN ∼ 0.5 V NN . As a result, the two-body ΛN system is unbound, and the lightest bound HN is the three-body hypertriton Λ 3 H in which the Λ is bound to a deuteron with the Λ-d separation energy being only ∼ 0.1 MeV corresponding to an exponential tail of radius ∼ 15 fm exclamation point In strong interactions the strangeness S is of course conserved, and the Λ is distinct from the nucleons. In a HN strangeness changes only in the weak decays of the Λ which can decay either via ''free'' pionic decay Λ → N + π or via induced decay Λ + N → N + N which is only possible in the presence of nucleons. Because of the small energy release the pionic decay is strongly suppressed in all but the lightest HN and the induced decay dominates. However, the weak decay lifetime ∼ 10 -10 s is in fact close to the lifetime of a free Λ. Since this is much longer than the strong interaction time ∼ 10 -22 s we can ignore the weak interactions when considering the binding of HN, just as for ordinary nuclei

  14. Constrained Deep Weak Supervision for Histopathology Image Segmentation.

    Science.gov (United States)

    Jia, Zhipeng; Huang, Xingyi; Chang, Eric I-Chao; Xu, Yan

    2017-11-01

    In this paper, we develop a new weakly supervised learning algorithm to learn to segment cancerous regions in histopathology images. This paper is under a multiple instance learning (MIL) framework with a new formulation, deep weak supervision (DWS); we also propose an effective way to introduce constraints to our neural networks to assist the learning process. The contributions of our algorithm are threefold: 1) we build an end-to-end learning system that segments cancerous regions with fully convolutional networks (FCNs) in which image-to-image weakly-supervised learning is performed; 2) we develop a DWS formulation to exploit multi-scale learning under weak supervision within FCNs; and 3) constraints about positive instances are introduced in our approach to effectively explore additional weakly supervised information that is easy to obtain and enjoy a significant boost to the learning process. The proposed algorithm, abbreviated as DWS-MIL, is easy to implement and can be trained efficiently. Our system demonstrates the state-of-the-art results on large-scale histopathology image data sets and can be applied to various applications in medical imaging beyond histopathology images, such as MRI, CT, and ultrasound images.

  15. Spectral Properties of AGN with Very Weak [O III] Lines

    Directory of Open Access Journals (Sweden)

    Kovacevic, J.

    2011-06-01

    Full Text Available The spectral properties of a sample of 58 Active GalacticNuclei (AGN spectra, in which emission [O~III] $lambdalambda$4959, 5007 AA lines are weak or totally absent, are analyzed. In order to investigate thephysical reason for the [O~III] emission suppression, the spectral propertiesof the weak [O~III] spectra sample are compared with the same properties of asample of 269 spectra with the strong [O~III] lines. The spectra are obtainedfrom Sloan Digital Sky Survey (SDSS Database. It is found that the objectswith the weak or absent [O~III] $lambdalambda$4959, 5007 AA linesgenerally have the high continuum luminosities (log($lambda$L$_{5100}$ $>$45, that they are very rare at smaller redshifts ($z <$ 0.3 and that theyusually have strong starburst influence. From the sample with weak or absent[O~III] lines, two boundary subgroups may be distinguished: the subgroup witha strong H$beta$ narrow component and subgroup with a very weak or negligibleH$beta$ narrow component. The physical causes for the [O~III] linessuppressing are probably different in these two subgroups: the [O~III] linesare absent in objects with strong narrow H$beta$ probably because of strongstarburst (SB activity, which produces high density of the gas, while in theobjects with the negligible narrow H$beta$, the reason for [O~III] and narrowH$beta$ suppression may be a low covering factor.

  16. Spectral properties of AGN with very weak [O III] lines

    Directory of Open Access Journals (Sweden)

    Kovačević J.

    2011-01-01

    Full Text Available The spectral properties of a sample of 58 Active Galactic Nuclei (AGN spectra, in which emission [O III] λλ4959, 5007 Å lines are weak or totally absent, are analyzed. In order to investigate the physical reason for the [O III] emission suppression, the spectral properties of the weak [O III] spectra sample are compared with the same properties of a sample of 269 spectra with the strong [O III] lines. The spectra are obtained from Sloan Digital Sky Survey (SDSS Database. It is found that the objects with the weak or absent [O III] λλ4959, 5007 Å lines generally have the high continuum luminosities (log(λL5100 > 45, that they are very rare at smaller redshifts (z < 0.3 and that they usually have strong starburst influence. From the sample with weak or absent [O III] lines, two boundary subgroups may be distinguished: the subgroup with a strong Hβ narrow component and subgroup with a very weak or negligible Hβ narrow component. The physical causes for the [O III] lines suppressing are probably different in these two subgroups: the [O III] lines are absent in objects with strong narrow Hβ probably because of strong starburst (SB activity, which produces high density of the gas, while in the objects with the negligible narrow Hβ, the reason for [O III] and narrow Hβ suppression may be a low covering factor.

  17. Learning from Weak and Noisy Labels for Semantic Segmentation

    KAUST Repository

    Lu, Zhiwu

    2016-04-08

    A weakly supervised semantic segmentation (WSSS) method aims to learn a segmentation model from weak (image-level) as opposed to strong (pixel-level) labels. By avoiding the tedious pixel-level annotation process, it can exploit the unlimited supply of user-tagged images from media-sharing sites such as Flickr for large scale applications. However, these ‘free’ tags/labels are often noisy and few existing works address the problem of learning with both weak and noisy labels. In this work, we cast the WSSS problem into a label noise reduction problem. Specifically, after segmenting each image into a set of superpixels, the weak and potentially noisy image-level labels are propagated to the superpixel level resulting in highly noisy labels; the key to semantic segmentation is thus to identify and correct the superpixel noisy labels. To this end, a novel L1-optimisation based sparse learning model is formulated to directly and explicitly detect noisy labels. To solve the L1-optimisation problem, we further develop an efficient learning algorithm by introducing an intermediate labelling variable. Extensive experiments on three benchmark datasets show that our method yields state-of-the-art results given noise-free labels, whilst significantly outperforming the existing methods when the weak labels are also noisy.

  18. New Physics in Single-Top Production

    CERN Document Server

    Kind, OM; The ATLAS collaboration

    2013-01-01

    In this presentation for TOP 2013 the latest results on searches of physics beyond the Standard Model using single-top signatures from CDF, CMS, D0 and ATLAS are collected. This includes searches for unknown resonances like W' or b*, measurements of the W helicity fractions and top polarisation in single-top events, as well as tests for CP violation, FCNC or anomalous weak couplings.

  19. Horizontal mergers and weak and strong competition commissions

    Directory of Open Access Journals (Sweden)

    Ristić Bojan

    2014-01-01

    Full Text Available In this paper we analyse the horizontal merger of companies in an already concentrated industry. The participants in mergers are obliged to submit notification to the Competition Commission but they also have the option of rejecting the merger. At the time of the notification submission the participants do not know whether the Commission is strong or weak, and they can complain to the Court if the Commission prohibits the merger. We model the strategic interaction between Participants and Commission in a dynamic game of incomplete information and determine weak perfect Bayesian equilibria. The main finding of our paper is that Participants will base their decision to submit notification on their belief in a weak Commission decision and will almost completely ignore the possibility of a strong Commission decision. We also provide a detailed examination of one case from Serbian regulatory practice, which coincides with the results of our game theoretical model.

  20. Competition among networks highlights the power of the weak

    Science.gov (United States)

    Iranzo, Jaime; Buldú, Javier M.; Aguirre, Jacobo

    2016-11-01

    The unpreventable connections between real networked systems have recently called for an examination of percolation, diffusion or synchronization phenomena in multilayer networks. Here we use network science and game theory to explore interactions in networks-of-networks and model these as a game for gaining importance. We propose a viewpoint where networks choose the connection strategies, in contrast with classical approaches where nodes are the active players. Specifically, we investigate how creating paths between networks leads to different Nash equilibria that determine their structural and dynamical properties. In a wide variety of cases, selecting adequate connections leads to a cooperative solution that allows weak networks to overcome the strongest opponent. Counterintuitively, each weak network can induce a global transition to such cooperative configuration regardless of the actions of the strongest network. This power of the weak reveals a critical dominance of the underdogs in the fate of networks-of-networks.

  1. On the scarcity of weak coupling in the string landscape

    Science.gov (United States)

    Halverson, James; Long, Cody; Sung, Benjamin

    2018-02-01

    We study the geometric requirements on a threefold base for the corresponding F-theory compactification to admit a weakly-coupled type IIB limit. We examine both the standard Sen limit and a more restrictive limit, and determine conditions sufficient for their non-existence for both toric bases and more general algebraic bases. In a large ensemble of geometries generated by base changing resolutions we derive an upper bound on the frequency with which a weak-coupling limit may occur, and find that such limits are extremely rare. Our results sharply quantify the widely held notion that the vast number of weakly-coupled IIB vacua is but a tiny fraction of the landscape.

  2. Implications of neutrino masses and mixing for weak processes

    International Nuclear Information System (INIS)

    Shrock, R.E.

    1981-01-01

    A general theory is presented of weak processes involving neutrinos which consistently incorporates the possibility of nonzero neutrino masses and associated lepton mixing. The theory leads to new tests for and bounds on such masses and mixing. These tests make use of (π,K)/sub l2/ decay, nuclear β decay, and μ and tau decays, among others. New experiments at SIN and KEK to apply the tests are mentioned. Further, some implications are discussed for (1) the analysis of the spectral parameters in leptonic decays to determine the Lorentz structure of the weak leptonic couplings; (2) fundamental weak interaction constants such as G/sub μ/, G/sub V/', f/sub π/, f/sub K/, V/sub uq/, q = d or s, m/sub W/, and m/sub Z/; and (3) neutrino propagation

  3. Biomechanical consequences of running with deep core muscle weakness.

    Science.gov (United States)

    Raabe, Margaret E; Chaudhari, Ajit M W

    2018-01-23

    The deep core muscles are often neglected or improperly trained in athletes. Improper function of this musculature may lead to abnormal spinal loading, muscle strain, or injury to spinal structures, all of which have been associated with increased low back pain (LBP) risk. The purpose of this study was to identify potential strategies used to compensate for weakness of the deep core musculature during running and to identify accompanying changes in compressive and shear spinal loads. Kinematically-driven simulations of overground running were created for eight healthy young adults in OpenSim at increasing levels of deep core muscle weakness. The deep core muscles (multifidus, quadratus lumborum, psoas, and deep fascicles of the erector spinae) were weakened individually and together. The superficial longissimus thoracis was a significant compensator for 4 out of 5 weakness conditions (p strength of the deep core musculature may increase a runner's risk of developing LBP. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Regularized inner products and weakly holomorphic Hecke eigenforms

    Science.gov (United States)

    Bringmann, Kathrin; Kane, Ben

    2018-01-01

    We show that the image of repeated differentiation on weak cusp forms is precisely the subspace which is orthogonal to the space of weakly holomorphic modular forms. This gives a new interpretation of weakly holomorphic Hecke eigenforms. The research of the first author is supported by the Alfried Krupp Prize for Young University Teachers of the Krupp foundation and the research leading to these results receives funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant agreement n. 335220—AQSER. The research of the second author was supported by grants from the Research Grants Council of the Hong Kong SAR, China (project numbers HKU 27300314, 17302515, and 17316416).

  5. Magnetization reversal in weak ferrimagnets and canted antiferromagnets

    International Nuclear Information System (INIS)

    Kageyama, H.; Khomskii, D.I.; Levitin, R.Z.; Markina, M.M.; Okuyama, T.; Uchimoto, T.; Vasil'ev, A.N.

    2003-01-01

    In some ferrimagnets the total magnetization vanishes at a certain compensation temperature T*. In weak magnetic fields, the magnetization can change sign at T* (the magnetization reversal). Much rarer is observation of ferrimagnetic-like response in canted antiferromagnets, where the weak ferromagnetic moment is due to the tilting of the sublattice magnetizations. The latter phenomenon was observed in nickel (II) formate dihydrate Ni(HCOO) 2 ·2H 2 O. The observed weak magnetic moment increases initially below T N =15.5 K, equals zero at T*=8.5 K and increases again at lowering temperature. The sign of the low-field magnetization at any given temperature is determined by the sample's magnetic prehistory and the signs are opposite to each other at T N

  6. Enhancing teleportation fidelity by means of weak measurements or reversal

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Liang, E-mail: lqiu@cumt.edu.cn [College of Sciences, China University of Mining and Technology, Xuzhou 221116 (China); Tang, Gang; Yang, Xianqing [College of Sciences, China University of Mining and Technology, Xuzhou 221116 (China); Wang, Anmin [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)

    2014-11-15

    The enhancement of teleportation fidelity by weak measurement or quantum measurement reversal is investigated. One qubit of a maximally entangled state undergoes the amplitude damping, and the subsequent application of weak measurement or quantum measurement reversal could improve the teleportation fidelity beyond the classical region. The improvement could not be attributed to the increasing of entanglement, quantum discord, classical correlation or total correlation. We declare that it should be owed to the probabilistic nature of the method. - Highlights: • The method’s probabilistic nature should be responsible for the improvement. • Quantum or classical correlation cannot explain the improvement. • The receiver cannot apply weak measurements. • The sender’s quantum measurement reversal is only useful for |Ψ{sup ±}〉.

  7. Josephson current and Andreev level dynamics in nanoscale superconducting weak links

    Energy Technology Data Exchange (ETDEWEB)

    Brunetti, Aldo

    2014-11-15

    In this thesis we focus on the interplay between proximity induced superconducting correlations and Coulomb interactions in a Josephson junction: i.e., in a system where two superconductors modeled as two s-wave superconductors at a phase difference φ are contacted by means of a weak link, in our case a quantum dot located in the contact. In the first part we study the Josephson current-phase relation for a multi-level quantum dot tunnel-contacted by two conventional s-waves superconductors. We determine in detail the conditions for observing a finite anomalous Josephson current, i.e. a supercurrent flowing at zero phase difference in a two-level dot with spin-orbit interactions, a weak magnetic (Zeeman) field, and in the presence of Coulomb interactions. This leads to an onset behavior I{sub a}∝sgn(B), interpreted as the sign of an incipient spontaneous breakdown of time-reversal symmetry. Moreover, we will provide conditions for realizing spatially separated - but topologically unprotected - Majorana bound states, whose signature in the system will be detectable via the current-phase relation. In the second part of the thesis, we address the Andreev bound state population dynamics in superconducting weak links (a superconducting 'atomic contact'), in which a poisoning mechanism due to the trapping of single quasiparticles can occur. Our motivation is that quantum coherent superconducting circuits are the most promising candidates for future large-scale quantum information processing devices. Moreover, quasiparticle poisoning has recently been observed in devices which contain a short superconducting weak link with few transport channels. We discuss a novel charge imbalance effect in the continuum quasiparticle population, which is due to phase fluctuations of the environment weakly coupled to the superconducting contact. This coupling enters the system as a transition rate connecting continuum quasiparticles and the Andreev bound state system. The

  8. Spatial averaging of velocity measurements in wall-bounded turbulence: single hot-wires

    International Nuclear Information System (INIS)

    Philip, Jimmy; Hutchins, Nicholas; Monty, Jason P; Marusic, Ivan

    2013-01-01

    Recent advancements in velocity measurements to understand high Reynolds number (Re) wall turbulence have pushed the boundaries of sensor size required to resolve the smallest scales. We present here a framework for studying the effect of finite sensor size on velocity measurements, and scrutinize in detail the behaviour of single-wire hot-wires. Starting with a general linear filter, expressions for the filtered correlation, spectrum and the corresponding variance are derived. Considering the special case of a box-type filter and a simple model for the two-point correlation, theoretical results are developed, which are favourably compared with the numerical simulation of hot-wires based on the turbulent channel flow direct numerical simulation databases. The results clarify the reason why previous studies found the approximate shape of the spectra not resolved by hot-wires as Gaussian. The length scale based on the correlation over the sensor length is found to be the appropriate length scale for characterizing averaging due to finite sensor size. The efficacy of the linear box filter is established by comparing the numerical simulation of hot-wires with experiments conducted at matched sensor lengths and Re in a channel flow, at least for hot-wire lengths of less than 40 in viscous scaling. Finally, a model of the streamwise two-point correlation is presented, which is employed to estimate the filtering effect on the peak of the streamwise velocity variances for a range of Re, and the model results compare favourably with that obtained from measurements. Even though the theoretical results are compared here in the case of wall turbulence, they are suitable for hot-wire measurements in turbulent flows in general. (paper)

  9. Molecular origin of the weak susceptibility of kinesin velocity to loads and its relation to the collective behavior of kinesins.

    Science.gov (United States)

    Wang, Qian; Diehl, Michael R; Jana, Biman; Cheung, Margaret S; Kolomeisky, Anatoly B; Onuchic, José N

    2017-10-10

    Motor proteins are active enzymatic molecules that support important cellular processes by transforming chemical energy into mechanical work. Although the structures and chemomechanical cycles of motor proteins have been extensively investigated, the sensitivity of a motor's velocity in response to a force is not well-understood. For kinesin, velocity is weakly influenced by a small to midrange external force (weak susceptibility) but is steeply reduced by a large force. Here, we utilize a structure-based molecular dynamic simulation to study the molecular origin of the weak susceptibility for a single kinesin. We show that the key step in controlling the velocity of a single kinesin under an external force is the ATP release from the microtubule-bound head. Only under large loading forces can the motor head release ATP at a fast rate, which significantly reduces the velocity of kinesin. It underpins the weak susceptibility that the velocity will not change at small to midrange forces. The molecular origin of this velocity reduction is that the neck linker of a kinesin only detaches from the motor head when pulled by a large force. This prompts the ATP binding site to adopt an open state, favoring ATP release and reducing the velocity. Furthermore, we show that two load-bearing kinesins are incapable of equally sharing the load unless they are very close to each other. As a consequence of the weak susceptibility, the trailing kinesin faces the challenge of catching up to the leading one, which accounts for experimentally observed weak cooperativity of kinesins motors. Copyright © 2017 the Author(s). Published by PNAS.

  10. Weak Approximation of SDEs by Discrete-Time Processes

    Directory of Open Access Journals (Sweden)

    Henryk Zähle

    2008-01-01

    Full Text Available We consider the martingale problem related to the solution of an SDE on the line. It is shown that the solution of this martingale problem can be approximated by solutions of the corresponding time-discrete martingale problems under some conditions. This criterion is especially expedient for establishing the convergence of population processes to SDEs. We also show that the criterion yields a weak Euler scheme approximation of SDEs under fairly weak assumptions on the driving force of the approximating processes.

  11. Computational aspects of the ultra-weak variational formulation

    International Nuclear Information System (INIS)

    Huttunen, Tomi; Monk, Peter; Kaipio, Jari P.

    2002-01-01

    The ultra-weak variational formulation (UWVF) approach has been proposed as an effective method for solving Helmholtz problems with high wave numbers. However, for coarse meshes the method can suffer from instability. In this paper we consider computational aspects of the ultra-weak variational formulation for the inhomogeneous Helmholtz problem. We introduce a method to improve the UWVF scheme and we compare iterative solvers for the resulting linear system. Computations for the acoustic transmission problem in 2D show that the new approach enables Helmholtz problems to be solved on a relatively coarse mesh for a wide range of wave numbers

  12. A Weak Value Based QKD Protocol Robust Against Detector Attacks

    Science.gov (United States)

    Troupe, James

    2015-03-01

    We propose a variation of the BB84 quantum key distribution protocol that utilizes the properties of weak values to insure the validity of the quantum bit error rate estimates used to detect an eavesdropper. The protocol is shown theoretically to be secure against recently demonstrated attacks utilizing detector blinding and control and should also be robust against all detector based hacking. Importantly, the new protocol promises to achieve this additional security without negatively impacting the secure key generation rate as compared to that originally promised by the standard BB84 scheme. Implementation of the weak measurements needed by the protocol should be very feasible using standard quantum optical techniques.

  13. Recollections on the establishment of the weak-interaction notion

    International Nuclear Information System (INIS)

    Pontecorvo, B.M.

    1989-01-01

    The author postulated a muon-electron symmetry as early as 1947 and this gave an early hint of a universal weak interaction and its involvement in particle decay. He also suggested families of leptons. Starting in 1947, a number of new unstable particles were discovered, some electrically neutral and some charged. Some had slow decays, such as the kaon and lambda ''strange'', which could not be explained using the strong interaction. The author was partially responsible for explaining hyperon and kaon decay via the weak interaction, for any four fermions, and for the idea of pair production. (UK)

  14. Observation of Weak Collapse in a Bose-Einstein Condensate

    Science.gov (United States)

    Eigen, Christoph; Gaunt, Alexander L.; Suleymanzade, Aziza; Navon, Nir; Hadzibabic, Zoran; Smith, Robert P.

    2016-10-01

    We study the collapse of an attractive atomic Bose-Einstein condensate prepared in the uniform potential of an optical-box trap. We characterize the critical point for collapse and the collapse dynamics, observing universal behavior in agreement with theoretical expectations. Most importantly, we observe a clear experimental signature of the counterintuitive weak collapse, namely, that making the system more unstable can result in a smaller particle loss. We experimentally determine the scaling laws that govern the weak-collapse atom loss, providing a benchmark for the general theories of nonlinear wave phenomena.

  15. Atmospheric Quantum Channels with Weak and Strong Turbulence

    Science.gov (United States)

    Vasylyev, D.; Semenov, A. A.; Vogel, W.

    2016-08-01

    The free-space transfer of high-fidelity optical signals between remote locations has many applications, including both classical and quantum communication, precision navigation, clock synchronization, etc. The physical processes that contribute to signal fading and loss need to be carefully analyzed in the theory of light propagation through the atmospheric turbulence. Here we derive the probability distribution for the atmospheric transmittance including beam wandering, beam shape deformation, and beam-broadening effects. Our model, referred to as the elliptic beam approximation, applies to weak, weak-to-moderate, and strong turbulence and hence to the most important regimes in atmospheric communication scenarios.

  16. Processing on weak electric signals by the autoregressive model

    Science.gov (United States)

    Ding, Jinli; Zhao, Jiayin; Wang, Lanzhou; Li, Qiao

    2008-10-01

    A model of the autoregressive model of weak electric signals in two plants was set up for the first time. The result of the AR model to forecast 10 values of the weak electric signals is well. It will construct a standard set of the AR model coefficient of the plant electric signal and the environmental factor, and can be used as the preferences for the intelligent autocontrol system based on the adaptive characteristic of plants to achieve the energy saving on agricultural productions.

  17. Novel relationships between superoscillations, weak values, and modular variables

    International Nuclear Information System (INIS)

    Tollaksen, Jeff

    2007-01-01

    We present several novel, unexpected relationships between superoscillations, weak values and modular variables. For example, we show how an uncertain phase, which characterizes the process of projecting a particle onto a superoscillatory region, can create the high-momentum associated with the super-oscillation. If an uncertain phase can localize the particle, then a definite phase can also localize it. This introduction of a relative phase corresponds to a nonlocal exchange of modular variables. We also present a new way to measure the nonlocality in the equation of motion for modular variables by using weak measurements

  18. Weak and strong solutions for differential equations in Banach spaces

    International Nuclear Information System (INIS)

    Gomaa, A.M.

    2003-01-01

    In this paper we give a generalization to recent results by using weak and strong measures of noncompactness. For f:[0,T]xE→E with E is a Banach space we prove that, under suitable assumptions, the Cauchy problem (fd((P) (ar((r((c(x(t)=f(t,x(t)),))(c(t/in R: =set membership[0,T],))))(r((c(x(0)=x 0 ,))(c()))))))) has at least one weak solution furthermore, with certain conditions, the Cauchy problem (P) has a solution. Next under a generalization of the compactness assumptions, we show that (P) has a solution too

  19. Is a weak violation of the Pauli principle possible?

    International Nuclear Information System (INIS)

    Ignat'ev, A.Y.; Kuz'min, V.A.

    1987-01-01

    We examine models in which there is a weak violation of the Pauli principle. A simple algebra of creation and annihilation operators is constructed which contains a parameter β and describes a weak violation of the Pauli principle (when β = 0 the Pauli principle is satisfied exactly). The commutation relations in this algebra turn out to be trilinear. A model based on this algebra is described. It allows transitions in which the Pauli principle is violated, but the probability of these transitions is suppressed by the quantity β 2 (even though the interaction Hamiltonian does not contain small parameters)

  20. Recollections on the establishment of the weak interaction notion

    International Nuclear Information System (INIS)

    Pontecorvo, B.

    1985-01-01

    The generalization of conception of weak interaction to the processes where strange particles discovered is given. Indepene dently of Pais, the author came to an idea of pair production of new (strange) particles. In Dubna the experiments have been performed on the search for processes of production of the same pair of Λ-particles in nucleon-nucleon collisions. To interprete negative results of these experiments the author suggested a scheme based on an assumption that the isotopic spin is conserved in strong interaction and is not conserved in the weak one. It followed from this scheme, in particularly, that K 0 and anti K 0 - different particles

  1. Observation of Weak Collapse in a Bose-Einstein Condensate

    Directory of Open Access Journals (Sweden)

    Christoph Eigen

    2016-12-01

    Full Text Available We study the collapse of an attractive atomic Bose-Einstein condensate prepared in the uniform potential of an optical-box trap. We characterize the critical point for collapse and the collapse dynamics, observing universal behavior in agreement with theoretical expectations. Most importantly, we observe a clear experimental signature of the counterintuitive weak collapse, namely, that making the system more unstable can result in a smaller particle loss. We experimentally determine the scaling laws that govern the weak-collapse atom loss, providing a benchmark for the general theories of nonlinear wave phenomena.

  2. A pulsated weak-resonant-cavity laser diode with transient wavelength scanning and tracking for injection-locked RZ transmission.

    Science.gov (United States)

    Lin, Gong-Ru; Chi, Yu-Chieh; Liao, Yu-Sheng; Kuo, Hao-Chung; Liao, Zhi-Wang; Wang, Hai-Lin; Lin, Gong-Cheng

    2012-06-18

    By spectrally slicing a single longitudinal-mode from a master weak-resonant-cavity Fabry-Perot laser diode with transient wavelength scanning and tracking functions, the broadened self-injection-locking of a slave weak-resonant-cavity Fabry-Perot laser diode is demonstrated to achieve bi-directional transmission in a 200-GHz array-waveguide-grating channelized dense-wavelength-division-multiplexing passive optical network system. Both the down- and up-stream slave weak-resonant-cavity Fabry-Perot laser diodes are non-return-to-zero modulated below threshold and coherently injection-locked to deliver the pulsed carrier for 25-km bi-directional 2.5 Gbits/s return-to-zero transmission. The master weak-resonant-cavity Fabry-Perot laser diode is gain-switched at near threshold condition and delivers an optical coherent pulse-train with its mode linewidth broadened from 0.2 to 0.8 nm by transient wavelength scanning, which facilitates the broadband injection-locking of the slave weak-resonant-cavity Fabry-Perot laser diodes with a threshold current reducing by 10 mA. Such a transient wavelength scanning induced spectral broadening greatly releases the limitation on wavelength injection-locking range required for the slave weak-resonant-cavity Fabry-Perot laser diode. The theoretical modeling and numerical simulation on the wavelength scanning and tracking effects of the master and slave weak-resonant-cavity Fabry-Perot laser diodes are performed. The receiving power sensitivity for back-to-back transmission at bit-error-rate transmission is less than 2 dB for all 16 channels.

  3. Data Mining for New Two- and One-Dimensional Weakly Bonded Solids and Lattice-Commensurate Heterostructures.

    Science.gov (United States)

    Cheon, Gowoon; Duerloo, Karel-Alexander N; Sendek, Austin D; Porter, Chase; Chen, Yuan; Reed, Evan J

    2017-03-08

    Layered materials held together by weak interactions including van der Waals forces, such as graphite, have attracted interest for both technological applications and fundamental physics in their layered form and as an isolated single-layer. Only a few dozen single-layer van der Waals solids have been subject to considerable research focus, although there are likely to be many more that could have superior properties. To identify a broad spectrum of layered materials, we present a novel data mining algorithm that determines the dimensionality of weakly bonded subcomponents based on the atomic positions of bulk, three-dimensional crystal structures. By applying this algorithm to the Materials Project database of over 50,000 inorganic crystals, we identify 1173 two-dimensional layered materials and 487 materials that consist of weakly bonded one-dimensional molecular chains. This is an order of magnitude increase in the number of identified materials with most materials not known as two- or one-dimensional materials. Moreover, we discover 98 weakly bonded heterostructures of two-dimensional and one-dimensional subcomponents that are found within bulk materials, opening new possibilities for much-studied assembly of van der Waals heterostructures. Chemical families of materials, band gaps, and point groups for the materials identified in this work are presented. Point group and piezoelectricity in layered materials are also evaluated in single-layer forms. Three hundred and twenty-five of these materials are expected to have piezoelectric monolayers with a variety of forms of the piezoelectric tensor. This work significantly extends the scope of potential low-dimensional weakly bonded solids to be investigated.

  4. Understanding the Nature of X-ray Weak Quasars

    Science.gov (United States)

    Brandt, William

    We propose a program of archival X-ray and related studies designed to advance understanding of the remarkable active galactic nucleus (AGN) population of X-ray weak quasars. These exceptional objects reveal phenomena that are more generally applicable but are difficult to investigate when more subtly expressed in the overall quasar population. X-ray weak quasars furthermore challenge a central tenet of X-ray astronomy that luminous X-ray emission is a universal property of efficiently accreting supermassive black holes; this idea underlies the utility of X-ray surveys for identifying AGNs throughout the Universe. Our previous findings indicate that understanding of Xray weak quasars is now primed for rapid further advances. Our studies of X-ray weak quasars will employ data from the vast archives of forefront X-ray missions, particularly XMM-Newton and Chandra, and they will also benefit greatly from the use of NuSTAR, ROSAT, Suzaku, Swift, GALEX, and WISE data. They are largely enabled by the enormous quasar samples delivered by modern widefield sky surveys. In particular, we will identify X-ray weak quasars using the serendipitous X-ray coverage of the 380,000 relatively bright quasars spectroscopically identified by the Sloan Digital Sky Survey (SDSS) from z 0.1-5.5; these are wellmatched to the depths of typical archival X-ray observations. The number of SDSS spectroscopic quasars has more than tripled in recent years, and the sample-size improvements at redshifts of z = 2-4, important for our investigations, are even more dramatic. We will construct an unprecedented new sample of X-ray weak quasars, about 20 times larger than those used currently, to enable systematic studies of the X-ray weakness phenomenon. This work should reveal the cause of X-ray weakness for quasars with weak emission lines, allowing testing of a model that relies upon small-scale shielding of ionizing photons by a thick inner accretion disk around a black hole accreting at a high

  5. Weak interactions of quarks and leptons: experimental status

    International Nuclear Information System (INIS)

    Wojcicki, S.

    1984-09-01

    The present experimental status of weak interactions is discussed with emphasis on the problems and questions and on the possible lines of future investigations. Major topics include; (1) the quark mixing matrix, (2) CP violation, (3) rare decays, (4) the lepton sector, and (5) right handed currents. 118 references

  6. Critical currents and weak links in melt textured R123

    International Nuclear Information System (INIS)

    Veal, B. W.; Zhang, H.; Claus, H.; Chen, L.; Paulikas, A. P.; Koshelev, A.; Crabtree, G. W.

    2000-01-01

    Weak link behavior is studied, using magnetization and Hall probe measurements of ring samples, in welded melt-textured R123 monoliths and in dual-seeded samples with disoriented domains. Techniques for welding samples yield transport currents across the junction that are in excess of 10 4 A/cm 2

  7. [A woman with skin abnormalities and muscle weakness

    NARCIS (Netherlands)

    Steggink, L.C.; Hettema, M.E.; Delsing, C.E.

    2013-01-01

    A 54-year-old woman presented to the emergency department with progressive proximal muscle weakness and a symmetric skin rash. Physical examination demonstrated a heliotrope rash, Gottron lesions, mechanic's hands and symmetrical erythema of the face, neck and upper legs. The diagnosis

  8. Attractive critical point from weak antilocalization on fractals

    NARCIS (Netherlands)

    Sticlet, D.C.; Akhmerov, A.R.

    2016-01-01

    We report an attractive critical point occurring in the Anderson localization scaling flow of symplectic models on fractals. The scaling theory of Anderson localization predicts that in disordered symplectic two-dimensional systems weak-antilocalization effects lead to a metal-insulator

  9. The Mathematical Strengths and Weaknesses of Children with Dyslexia

    Science.gov (United States)

    Simmons, Fiona R.; Singleton, Chris

    2009-01-01

    This paper reports the findings of two related studies that examined the mathematical strengths and weaknesses of children with dyslexia. In study one, dyslexic children were compared to children without special educational needs on tests that assessed arithmetic fact recall, place value understanding and counting speed. Study two used the same…

  10. Weak localization in few-layer black phosphorus

    International Nuclear Information System (INIS)

    Du, Yuchen; Neal, Adam T; Zhou, Hong; Ye, Peide D

    2016-01-01

    We have conducted a comprehensive investigation into the magneto-transport properties of few-layer black phosphorus in terms of phase coherence length, phase coherence time, and mobility via weak localization measurement and Hall-effect measurement. We present magnetoresistance data showing the weak localization effect in bare p-type few-layer black phosphorus and reveal its strong dependence on temperature and carrier concentration. The measured weak localization agrees well with the Hikami–Larkin–Nagaoka model and the extracted phase coherence length of 104 nm at 350 mK, decreasing as ∼T −0.513+−0.053 with increased temperature. Weak localization measurement allows us to qualitatively probe the temperature-dependent phase coherence time τ ϕ , which is in agreement with the theory of carrier interaction in the diffusive regime. We also observe the universal conductance fluctuation phenomenon in few-layer black phosphorus within moderate magnetic field and low temperature regime. (paper)

  11. Cardial myxoma associated with clinical weakness and thorombocytopenia: case report

    Directory of Open Access Journals (Sweden)

    Mahmoud Hosseinzadeh Maleki

    2013-02-01

    Full Text Available Atrial myxomas is the most prevalent benign heart tumor which is presented with a wide variety of symptoms. We introduce a case who suffered left atrial myxoma associated with clinical weakness and thorombocytopenia. The clinical symptoms of the patient rapidly disappeared one week after cardial myxoma resection.

  12. Weakly nonlinear electron plasma waves in collisional plasmas

    DEFF Research Database (Denmark)

    Pecseli, H. L.; Rasmussen, J. Juul; Tagare, S. G.

    1986-01-01

    The nonlinear evolution of a high frequency plasma wave in a weakly magnetized, collisional plasma is considered. In addition to the ponderomotive-force-nonlinearity the nonlinearity due to the heating of the electrons is taken into account. A set of nonlinear equations including the effect...

  13. Cinematography of weakly - luminous transient phenomena using image converters

    International Nuclear Information System (INIS)

    Stevenin, P.; Jacquot, C.

    1966-01-01

    After a review on the physical of optical informations emitted by a light source of weak intensity and short duration, the authors describe a high gain device by associating two image converters. The present specifications are given in the domain of high speed cinematography and spectrometry. (authors) [fr

  14. Molecular physiology of weak organic acid stress in Bacillus subtilis

    NARCIS (Netherlands)

    van Beilen, J.W.A.

    2013-01-01

    The mechanism by which weak organic acid (WOA) preservatives inhibit growth of microorganisms may differ between different WOAs and these differences are not well understood. The aim of this thesis has been to obtain a better understanding of the mode of action of these preservatives by which they

  15. Towards a theory of weak hadronic decays of charmed particles

    International Nuclear Information System (INIS)

    Blok, B.Yu.; Shifman, M.A.

    1986-01-01

    Weak decays of charmed mesons are considered. A new quantitative framework for theoretical analysis of nonleptonic two-body decays based on the QCD sum rules are proposed. This is the first of a series of papers devoted to the subject. Theoretical foundations of the approach ensuring model-independent predictions for the partial decay widths are discussed

  16. Nonlinear shock structure in a weakly ionised magnetoplasma

    Directory of Open Access Journals (Sweden)

    C. B. Dwivedi

    1994-12-01

    Full Text Available The formation of a neutral induced weak nonlinear shock structure in a weakly ionised magnetoplasma has been analytically investigated. Using the reductive perturbation method, basic dynamical equations of a three-component (electron, ion and neutral plasma have been reduced to a well-known Burger equation which can support a weak shock solution. Its stationary and initial value solutions have been derived to describe the characteristics of the weak shock profile. Asymptotic behaviour of the Burger solution results in a saw-tooth structure which has a practical implication to predict the nonlinear steepened structure of the nighttime irregularity in the lower portion of the Earth's ionosphere. Accordingly, it is suggested that the observation of saw-tooth shape of nighttime irregularity at 92 km could be attributed to the nonlinear saturation of the NILF mode instability as proposed by Dwivedi and Das in 1992. However, exact experimental verification of this suggestion requires more data on nighttime irregularity in the mesosphere and lower thermosphere (80-95 km for a wide range of scale sizes extending up to about 1 km and above.

  17. Weak Poincar\\'e Inequality for Convolution Probability Measures

    OpenAIRE

    Cheng, Li-Juan; Zhang, Shao-Qin

    2014-01-01

    By using Lyapunov conditions, weak Poincar\\'e inequalities are established for some probability measures on a manifold $(M,g)$. These results are further applied to the convolution of two probability measures on $\\R^d$. Along with explicit results we study concrete examples.

  18. Early Results from the Q{sub weak} Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Androic, D; Armstrong, D S; Asaturyan, A; Averett, T; Balewski, J; Beaufait, J; Beminiwattha, R S; Benesch, J; Benmokhtar, F; Birchall, J; Carlini, R D; Cates, G D; Cornejo, J C; Covrig, S; Dalton, M M; Davis, C A; Deconinck, W; Diefenbach, J; Dowd, J F; Dunne, J A; Dutta, D; Duvall, W S; Elaasar, M; Falk, W R; Finn, J M; Forest, T; Gaskel, D; Gericke, M T.W.; Grames, J; Gray, V M; Grimm, K; Guo, F; Hoskins, J R; Johnston, K; Jones, D; Jones, M; Jones, R; Kargiantoulakis, M; King, P M; Korkmaz, E; Kowalski, S; Leacock, J; Leckey, J; Lee, A R; Lee, J H; Lee, L; MacEwan, S; Mack, D; Magee, J A; Mahurin, R; Mammei, J; Martin, J; McHugh, M J; Meekins, D; Mei, J; Michaels, R; Micherdzinska, A; Mkrtchyan, A; Mkrtchyan, H; Morgan, N; Myers, K E; Narayan, A; Ndukum, L Z; Nelyubin, V; W T H, Nuruzzaman; Oers, van; Opper, A K; Page, S A; Pan, J; Paschke, K; Phillips, S K; Pitt, M L; Poelker, M; Rajotte, J F; Ramsay, W D; Roche, J; Sawatzky, B; Seva, T; Shabestari, M H; Silwal, R; Simicevic, N; Smith, G R; Solvignon, P; Spayde, D T; Subedi, A; Subedi, R; Suleiman, R; Tadevosyan, V; Tobias, W A; Tvaskis, V; Waidyawansa, B; Wang, P; Wells, S P; Wood, S A; Yang, S; Young, R D; Zhamkochyan, S

    2014-03-01

    A subset of results from the recently completed Jefferson Lab Q{sub weak} experiment are reported. This experiment, sensitive to physics beyond the Standard Model, exploits the small parity-violating asymmetry in elastic {vector e}p scattering to provide the first determination of the protons weak charge Q{sub w}{sup p}. The experiment employed a 180 {micro}A longitudinally polarized 1.16 GeV electron beam on a 35 cm long liquid hydrogen target. Scattered electrons corresponding to Q{sup 2} of 0.025 GeV{sup 2} were detected in eight Cerenkov detectors arrayed symmetrically around the beam axis. The goals of the experiment were to provide a measure of Q{sub w}{sup p} to 4.2 percent (combined statistical and systematic error), which implies a measure of sin2(thetaw) at the level of 0.3 percent, and to help constrain the vector weak quark charges C{sub 1u} and C{sub 1d}. The experimental method is described, with particular focus on the challenges associated with the worlds highest power LH{sub 2} target. The new constraints on C{sub 1u} and C{sub 1d} provided by the subset of the experiments data analyzed to date will also be shown, together with the extracted weak charge of the neutron.

  19. Overcoming Microsoft Excel's Weaknesses for Crop Model Building and Simulations

    Science.gov (United States)

    Sung, Christopher Teh Boon

    2011-01-01

    Using spreadsheets such as Microsoft Excel for building crop models and running simulations can be beneficial. Excel is easy to use, powerful, and versatile, and it requires the least proficiency in computer programming compared to other programming platforms. Excel, however, has several weaknesses: it does not directly support loops for iterative…

  20. Weakly Nonlinear Waves with Slowly-Varying Speed | Chikwendu ...

    African Journals Online (AJOL)

    A previously developed method of generating uniformly valid, multiple- scale asymptotic expansions for the solution of weakly nonlinear one-dimensional wave equations is applied to problems with slowly-varying speed. The method is also shown to be applicable specifically to periodic initial data.

  1. Strengths weaknesses opportunities and threats of blended learning ...

    African Journals Online (AJOL)

    Aim: The aim of this study was to identify the strengths, weaknesses, opportunities and threats (SWOT) of BL in a premedical class. Subjects and Methods: It was a cross‑sectional study. Ninety six students in a premedical cell biology class participated in the study. SWOT analysis of students' perceptions was conducted ...

  2. Upper hybrid wave collapse in weakly magnetized plasmas

    DEFF Research Database (Denmark)

    Thomsen, Kenneth; Juul Rasmussen, Jens; Pécseli, H. L.

    1983-01-01

    The collapse of electrostatic upper hybrid waves in weakly magnetized plasmas is considered with particular attention to include dispersive low-frequency waves in the equations governing the ion dynamics. Considering a magnetic-field aligned cylindrical collapse we demonstrate that a magnetic field...

  3. Global weak solution for a equations in plasma

    International Nuclear Information System (INIS)

    Guo Boling; Huang Daiwen

    2010-01-01

    The existence of global weak solutions of the initial boundary value problem to a simplified equations, derived from the equations of two fluid system in plasma, is proven by using energy method and some embedding theorems in Sobolev-Orlicz space.

  4. Weakly time consistent concave valuations and their dual representations

    NARCIS (Netherlands)

    Roorda, B.; Schumacher, Hans

    We derive dual characterizations of two notions of weak time consistency for concave valuations, which are convex risk measures under a positive sign convention. Combined with a suitable risk aversion property, these notions are shown to amount to three simple rules for not necessarily minimal

  5. Weakly time consistent concave valuations and their dual representations

    NARCIS (Netherlands)

    Roorda, Berend; Schumacher, Johannes M.

    2016-01-01

    We derive dual characterizations of two notions of weak time consistency for concave valuations, which are convex risk measures under a positive sign convention. Combined with a suitable risk aversion property, these notions are shown to amount to three simple rules for not necessarily minimal

  6. Pelczynski's property (V) and weak* basic sequences | Cilia ...

    African Journals Online (AJOL)

    In this note we study the property (V) of Pelczynski, in a Banach space X, in relation with the presence, in the dual Banach space X*, of suitable weak* basic sequences. We answer negatively to a question posed by John and we prove that, if X is a Banach space with the Property (V) of Pelczynski and the Gelfand Phillips ...

  7. Weak convergence of Jacobian determinants under asymmetric assumptions

    Directory of Open Access Journals (Sweden)

    Teresa Alberico

    2012-05-01

    Full Text Available Let $\\Om$ be a bounded open set in $\\R^2$ sufficiently smooth and $f_k=(u_k,v_k$ and $f=(u,v$ mappings belong to the Sobolev space $W^{1,2}(\\Om,\\R^2$. We prove that if the sequence of Jacobians $J_{f_k}$ converges to a measure $\\mu$ in sense of measures andif one allows different assumptions on the two components of $f_k$ and $f$, e.g.$$u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,2}(\\Om \\qquad \\, v_k \\rightharpoonup v \\;\\;\\mbox{weakly in} \\;\\; W^{1,q}(\\Om$$for some $q\\in(1,2$, then\\begin{equation}\\label{0}d\\mu=J_f\\,dz.\\end{equation}Moreover, we show that this result is optimal in the sense that conclusion fails for $q=1$.On the other hand, we prove that \\eqref{0} remains valid also if one considers the case $q=1$, but it is necessary to require that $u_k$ weakly converges to $u$ in a Zygmund-Sobolev space with a slightly higher degree of regularity than $W^{1,2}(\\Om$ and precisely$$ u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,L^2 \\log^\\alpha L}(\\Om$$for some $\\alpha >1$.    

  8. Gap asymptotics in a weakly bent leaky quantum wire

    Czech Academy of Sciences Publication Activity Database

    Exner, Pavel; Kondej, S.

    2015-01-01

    Roč. 48, č. 49 (2015), s. 495301 ISSN 1751-8113 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : singular Schroedinger operators * delta interaction * leaky quantum wires * weak perturbation * asymptotic expansion Subject RIV: BE - Theoretical Physics Impact factor: 1.933, year: 2015

  9. Gauge theories of weak, electromagnetic and strong interactions

    International Nuclear Information System (INIS)

    Boehm, M.; Joos, H.

    1978-05-01

    This 10 lectures are devided into the chapters: Phenomenological basis of the quantum chromodynamics, phenomenology of weak interactions, quantum electrodynamics and gauge invariance, from the fermimodel to the quantum flavor dynamics, on the quantum theory of yang-mills-fields, spontaneous symmetry breaking - the Higgs-Kibble-mechanism, the Salam-Weinberg-model, asymptotic freedom, quark confinement and charmonium. (WL) [de

  10. Quantum ion-acoustic solitary waves in weak relativistic plasma

    Indian Academy of Sciences (India)

    A linear dispersion relation is also obtained taking into account the relativistic effect. The properties of quantum ion-acoustic solitary waves, obtained from the deformed KdV equation, are studied taking into account the quantum mechanical effects in the weak relativistic limit. It is found that relativistic effects significantly ...

  11. Nonlinear propagation of weakly relativistic ion-acoustic waves in ...

    Indian Academy of Sciences (India)

    2016-10-06

    Oct 6, 2016 ... Abstract. This work presents theoretical and numerical discussion on the dynamics of ion-acoustic solitary wave for weakly relativistic regime in unmagnetized plasma comprising non-extensive electrons, Boltzmann positrons and relativistic ions. In order to analyse the nonlinear propagation phenomena, ...

  12. Gauge-invariant formalism of cosmological weak lensing

    Science.gov (United States)

    Yoo, Jaiyul; Grimm, Nastassia; Mitsou, Ermis; Amara, Adam; Refregier, Alexandre

    2018-04-01

    We present the gauge-invariant formalism of cosmological weak lensing, accounting for all the relativistic effects due to the scalar, vector, and tensor perturbations at the linear order. While the light propagation is fully described by the geodesic equation, the relation of the photon wavevector to the physical quantities requires the specification of the frames, where they are defined. By constructing the local tetrad bases at the observer and the source positions, we clarify the relation of the weak lensing observables such as the convergence, the shear, and the rotation to the physical size and shape defined in the source rest-frame and the observed angle and redshift measured in the observer rest-frame. Compared to the standard lensing formalism, additional relativistic effects contribute to all the lensing observables. We explicitly verify the gauge-invariance of the lensing observables and compare our results to previous work. In particular, we demonstrate that even in the presence of the vector and tensor perturbations, the physical rotation of the lensing observables vanishes at the linear order, while the tetrad basis rotates along the light propagation compared to a FRW coordinate. Though the latter is often used as a probe of primordial gravitational waves, the rotation of the tetrad basis is indeed not a physical observable. We further clarify its relation to the E-B decomposition in weak lensing. Our formalism provides a transparent and comprehensive perspective of cosmological weak lensing.

  13. Weak interactions physics: from its birth to the eletroweak model

    International Nuclear Information System (INIS)

    Lopes, J.L.

    1987-01-01

    A review of the evolution of weak interaction physics from its beginning (Fermi-Majorana-Perrin) to the eletroweak model (Glashow-Weinberg-Salam). Contributions from Brazilian physicists are specially mentioned as well as the first prediction of electroweak-unification, of the neutral intermediate vector Z 0 and the first approximate value of the mass of the W-bosons. (Author) [pt

  14. An infinite-dimensional weak KAM theory via random variables

    KAUST Repository

    Gomes, Diogo A.

    2016-08-31

    We develop several aspects of the infinite-dimensional Weak KAM theory using a random variables\\' approach. We prove that the infinite-dimensional cell problem admits a viscosity solution that is a fixed point of the Lax-Oleinik semigroup. Furthermore, we show the existence of invariant minimizing measures and calibrated curves defined on R.

  15. Towards Metamathematics of Weak Arithmetics over Fuzzy Logic

    Czech Academy of Sciences Publication Activity Database

    Hájek, Petr

    2011-01-01

    Roč. 19, č. 3 (2011), s. 467-475 ISSN 1367-0751 R&D Projects: GA AV ČR IAA100300503 Institutional research plan: CEZ:AV0Z10300504 Keywords : weak arithmetics * mathematical fuzzy logic * Gödel’s theorem * essential undecidability Subject RIV: BA - General Mathematics Impact factor: 0.913, year: 2011

  16. School-Based Sexuality Education in Portugal: Strengths and Weaknesses

    Science.gov (United States)

    Rocha, Ana Cristina; Leal, Cláudia; Duarte, Cidália

    2016-01-01

    Portugal, like many other countries, faces obstacles regarding school-based sexuality education. This paper explores Portuguese schools' approaches to implementing sexuality education at a local level, and provides a critical analysis of potential strengths and weaknesses. Documents related to sexuality education in a convenience sample of 89…

  17. Sufficient conditions for uniqueness of the weak value

    International Nuclear Information System (INIS)

    Dressel, J; Jordan, A N

    2012-01-01

    We review and clarify the sufficient conditions for uniquely defining the generalized weak value as the weak limit of a conditioned average using the contextual values formalism introduced in Dressel, Agarwal and Jordan (2010 Phys. Rev. Lett. http://dx.doi.org/10.1103/PhysRevLett.104.240401). We also respond to criticism of our work by Parrott (arXiv:1105.4188v1) concerning a proposed counter-example to the uniqueness of the definition of the generalized weak value. The counter-example does not satisfy our prescription in the case of an underspecified measurement context. We show that when the contextual values formalism is properly applied to this example, a natural interpretation of the measurement emerges and the unique definition in the weak limit holds. We also prove a theorem regarding the uniqueness of the definition under our sufficient conditions for the general case. Finally, a second proposed counter-example by Parrott (arXiv:1105.4188v6) is shown not to satisfy the sufficiency conditions for the provided theorem. (paper)

  18. Linear operator inequalities for strongly stable weakly regular linear systems

    NARCIS (Netherlands)

    Curtain, RF

    2001-01-01

    We consider the question of the existence of solutions to certain linear operator inequalities (Lur'e equations) for strongly stable, weakly regular linear systems with generating operators A, B, C, 0. These operator inequalities are related to the spectral factorization of an associated Popov

  19. Inversion for weak triclinic anisotropy from acoustic axes

    Czech Academy of Sciences Publication Activity Database

    Vavryčuk, Václav

    2013-01-01

    Roč. 50, č. 8 (2013), s. 1271-1282 ISSN 0165-2125 R&D Projects: GA AV ČR IAA300120801 Institutional support: RVO:67985530 Keywords : acoustic axis * weak anisotropy * elastic waves * wave polarization Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.303, year: 2013

  20. Unifying weak and electromagnetic forces in Weinberg-Salam theory

    International Nuclear Information System (INIS)

    Savoy, C.A.

    1978-01-01

    In this introduction to the ideas related to the unified gauge theories of the weak and electromagnetic interactions, we begin with the motivations for its basic principles. Then, the formalism is briefly developed, in particular the so-called Higgs mechanism. The advantages and the consequences of the (non-abelian) gauge invariance are emphasized, together with the experimental tests of the theory [fr

  1. Integrated Giant Magnetoresistance Technology for Approachable Weak Biomagnetic Signal Detections.

    Science.gov (United States)

    Shen, Hui-Min; Hu, Liang; Fu, Xin

    2018-01-07

    With the extensive applications of biomagnetic signals derived from active biological tissue in both clinical diagnoses and human-computer-interaction, there is an increasing need for approachable weak biomagnetic sensing technology. The inherent merits of giant magnetoresistance (GMR) and its high integration with multiple technologies makes it possible to detect weak biomagnetic signals with micron-sized, non-cooled and low-cost sensors, considering that the magnetic field intensity attenuates rapidly with distance. This paper focuses on the state-of-art in integrated GMR technology for approachable biomagnetic sensing from the perspective of discipline fusion between them. The progress in integrated GMR to overcome the challenges in weak biomagnetic signal detection towards high resolution portable applications is addressed. The various strategies for 1/ f noise reduction and sensitivity enhancement in integrated GMR technology for sub-pT biomagnetic signal recording are discussed. In this paper, we review the developments of integrated GMR technology for in vivo/vitro biomagnetic source imaging and demonstrate how integrated GMR can be utilized for biomagnetic field detection. Since the field sensitivity of integrated GMR technology is being pushed to fT/Hz 0.5 with the focused efforts, it is believed that the potential of integrated GMR technology will make it preferred choice in weak biomagnetic signal detection in the future.

  2. On the dynamic buckling of a weakly damped nonlinear elastic ...

    African Journals Online (AJOL)

    In this paper we determine the dynamic buckling load of a strictly nonlinear but weakly damped elastic oscillatory model structure subjected to small perturbations The loading history is explicitly time dependent and varies slowly with time over a natural period of oscillation of the structure. A multiple timing regular ...

  3. Policy-based benchmarking of weak heaps and their relatives

    DEFF Research Database (Denmark)

    Bruun, Asger; Edelkamp, Stefan; Katajainen, Jyrki

    2010-01-01

    ), and a run-relaxed weak queue that of both insert and decrease to O(1). As competitors to these structures, we considered a binary heap, a Fibonacci heap, and a pairing heap. Generic programming techniques were heavily used in the code development. For benchmarking purposes we developed several component...

  4. Causes of Mortality in ICU-Acquired Weakness

    NARCIS (Netherlands)

    van Wagenberg, Linda; Witteveen, Esther; Wieske, Luuk; Horn, Janneke

    2017-01-01

    Intensive care unit-acquired weakness (ICU-AW) is a common complication of critical illness and is associated with increased mortality, longer mechanical ventilation and longer hospital stay. Little is known about the causes of mortality in patients with ICU-AW. In this study, we aimed to give an

  5. A Weak Convergence to Hermite Process by Martingale Differences

    Directory of Open Access Journals (Sweden)

    Xichao Sun

    2014-01-01

    Full Text Available We consider the weak convergence to general Hermite process ZH,k of order k with index H. By applying martingale differences we construct a sequence {ZH,kn ,  n=1,2,…} of multiple Wiener-Itô stochastic integrals such that it converges in distribution to the Hermite process ZH,k.

  6. Computer-aided visualization of muscle weakness distribution.

    NARCIS (Netherlands)

    Pieterse, A.J.; Voermans, N.C.; Tuinenga, H.S.; Engelen, B.G.M. van

    2008-01-01

    We present a computer program for visualizing muscle weakness distribution in patients with neuromuscular disorders. Ordinal muscle strength data can be computed in the program. Data are visualized as the prime movers of the testmovements in an image of the human body and a separate image of the

  7. Weak point disorder in strongly fluctuating flux-line liquids

    Indian Academy of Sciences (India)

    We consider the effect of weak uncorrelated quenched disorder (point defects) on a strongly fluctuating flux-line liquid. We use a hydrodynamic model which is based on mapping the flux-line system onto a quantum liquid of relativistic charged bosons in 2 + 1 dimensions [P Benetatos and M C Marchetti, Phys. Rev. B64 ...

  8. Weak point disorder in strongly fluctuating flux-line liquids

    Indian Academy of Sciences (India)

    Abstract. We consider the effect of weak uncorrelated quenched disorder (point defects) on a strongly fluctuating flux-line liquid. We use a hydrodynamic model which is based on mapping the flux-line system onto a quantum liquid of relativistic charged bosons in 2 + 1 dimensions [P Benetatos and M C Marchetti, Phys. Rev.

  9. Weak interactions of quarks and leptons: experimental status

    Energy Technology Data Exchange (ETDEWEB)

    Wojcicki, S.

    1984-09-01

    The present experimental status of weak interactions is discussed with emphasis on the problems and questions and on the possible lines of future investigations. Major topics include; (1) the quark mixing matrix, (2) CP violation, (3) rare decays, (4) the lepton sector, and (5) right handed currents. 118 references. (WHK)

  10. Weak Humanism and the Economic Mission of English Education

    Science.gov (United States)

    Collin, Ross

    2018-01-01

    This article examines a theory of "weak humanism" that says (1) secondary English classes should focus on personal development and culture and (2) English classes should deliver economic benefits indirectly, i.e. as knock-on effects of studying the personal and the cultural. Economic benefits are defined here as knowledge/skills students…

  11. A young man with progressive weakness, double vision and ...

    African Journals Online (AJOL)

    revealed double vision during lateral gaze in either direc- tion. There was, however, no overt evidence of opthalmo- plegia. The remainder of his cranial nerves were normal. He had symmetrical proximal muscle weakness of his up- per and lower limbs; this included neck flexion (MRC score. 3/5), abduction and adduction of ...

  12. On the existence of weak solutions of quantum stochastic differential ...

    African Journals Online (AJOL)

    We establish further results concerning the existence, uniqueness and stability of weak solutions of quantum stochastic differential equations (QSDEs). Our results are achieved by considering a more general Lipschit condition on the coefficients than our previous considerations in [1]. We exhibit a class of Lipschitzian ...

  13. Weakly nonlinear analysis of two dimensional sheared granular flow

    NARCIS (Netherlands)

    Saitoh, K.; Hayakawa, Hisao

    2011-01-01

    Weakly nonlinear analysis of a two dimensional sheared granular flow is carried out under the Lees-Edwards boundary condition. We derive the time dependent Ginzburg–Landau equation of a disturbance amplitude starting from a set of granular hydrodynamic equations and discuss the bifurcation of the

  14. Analytical solutions of weakly coupled map lattices using recurrence relations

    Energy Technology Data Exchange (ETDEWEB)

    Sotelo Herrera, Dolores, E-mail: dsh@dfmf.uned.e [Applied Maths, EUITI, UPM, Ronda de Valencia, 3-28012 Madrid (Spain); San Martin, Jesus [Applied Maths, EUITI, UPM, Ronda de Valencia, 3-28012 Madrid (Spain); Dep. Fisica Matematica y de Fluidos, UNED, Senda del Rey 9-28040 Madrid (Spain)

    2009-07-20

    By using asymptotic methods recurrence relations are found that rule weakly CML evolution, with both global and diffusive coupling. The solutions obtained from these relations are very general because they do not hold restrictions about boundary conditions, initial conditions and number of oscilators in the CML. Furthermore, oscillators are ruled by an arbitraty C{sup 2} function.

  15. The role of weak intermolecular CH… F interactions in ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 123; Issue 4. The role of weak intermolecular C-H…F interactions in supramolecular assembly: Structural investigations on 3,5- dibenzylidene-piperidin-4-one and database analysis. R S Rathore N S Karthikeyan Y Alekhya K Sathiyanarayanan P G Aravindan.

  16. Enhancing robustness of multiparty quantum correlations using weak measurement

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Uttam, E-mail: uttamsingh@hri.res.in [Quantum Information and Computation Group, Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Mishra, Utkarsh, E-mail: utkarsh@hri.res.in [Quantum Information and Computation Group, Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Dhar, Himadri Shekhar, E-mail: dhar.himadri@gmail.com [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India)

    2014-11-15

    Multipartite quantum correlations are important resources for the development of quantum information and computation protocols. However, the resourcefulness of multipartite quantum correlations in practical settings is limited by its fragility under decoherence due to environmental interactions. Though there exist protocols to protect bipartite entanglement under decoherence, the implementation of such protocols for multipartite quantum correlations has not been sufficiently explored. Here, we study the effect of local amplitude damping channel on the generalized Greenberger–Horne–Zeilinger state, and use a protocol of optimal reversal quantum weak measurement to protect the multipartite quantum correlations. We observe that the weak measurement reversal protocol enhances the robustness of multipartite quantum correlations. Further it increases the critical damping value that corresponds to entanglement sudden death. To emphasize the efficacy of the technique in protection of multipartite quantum correlation, we investigate two proximately related quantum communication tasks, namely, quantum teleportation in a one sender, many receivers setting and multiparty quantum information splitting, through a local amplitude damping channel. We observe an increase in the average fidelity of both the quantum communication tasks under the weak measurement reversal protocol. The method may prove beneficial, for combating external interactions, in other quantum information tasks using multipartite resources. - Highlights: • Extension of weak measurement reversal scheme to protect multiparty quantum correlations. • Protection of multiparty quantum correlation under local amplitude damping noise. • Enhanced fidelity of quantum teleportation in one sender and many receivers setting. • Enhanced fidelity of quantum information splitting protocol.

  17. Phenomenology and cosmology of weakly coupled string theory

    International Nuclear Information System (INIS)

    Gaillard, Mary K.

    1998-01-01

    The weakly coupled vacuum of E 8 (circle t imes) E 8 heterotic string theory remains an attractive scenario for phenomenology and cosmology. The particle spectrum is reviewed and the issues of gauge coupling unification, dilaton stabilization and modular cosmology are discussed. A specific model for condensation and supersymmetry breaking, that respects known constraints from string theory and is phenomenologically viable, is described

  18. Hadronic weak charges and parity-violating forward Compton scattering

    Science.gov (United States)

    Gorchtein, Mikhail; Spiesberger, Hubert

    2016-11-01

    Background: Parity-violating elastic electron-nucleon scattering at low momentum transfer allows one to access the nucleon's weak charge, the vector coupling of the Z -boson to the nucleon. In the Standard Model and at tree level, the weak charge of the proton is related to the weak mixing angle and accidentally suppressed, QWp ,tree=1 -4 sin2θW≈0.07 . Modern experiments aim at extracting QWp at ˜1 % accuracy. Similarly, parity nonconservation in atoms allows to access the weak charge of atomic nuclei. Purpose: We consider a novel class of radiative corrections due to the exchange of two photons, with parity violation in the hadronic/nuclear system. These corrections are prone to long-range interactions and may affect the extraction of sin2θW from the experimental data at the relevant level of precision. Methods: The two-photon exchange contribution to the parity-violating electron-proton scattering amplitude is studied in the framework of forward dispersion relations. We address the general properties of the parity-violating forward Compton scattering amplitude and use relativistic chiral perturbation theory to provide the first field-theoretical proof that it obeys a superconvergence relation. Results: We show that the significance of this new correction increases with the beam energy in parity-violating electron scattering, but the superconvergence relation protects the formal definition of the weak charge as a limit at zero-momentum transfer and zero energy. We evaluate the new correction in a hadronic model with pion loops and the Δ (1232 ) resonance, supplemented with a high-energy contribution. For the kinematic conditions of existing and upcoming experiments we show that two-photon exchange corrections with hadronic or nuclear parity violation do not pose a problem for the interpretation of the data in terms of the weak mixing angle at the present level of accuracy. Conclusions: Two-photon exchange in presence of hadronic or nuclear parity violation

  19. Nuclear weapons complex. Weaknesses in DOE's nonnuclear consolidation plan

    International Nuclear Information System (INIS)

    Wells, James E. Jr.; Fenzel, William F.; Schulze, John R.; Gaffigan, Mark E.

    1992-11-01

    Nuclear weapons contain a wide variety of nonnuclear components - items that are not made from nuclear materials. These components comprise the majority of parts in nuclear weapons, including the ones needed to guide weapons to their targets, initiate the nuclear explosion, increase the weapons' explosive yield, and ensure the weapons' safety and security. DOE has three facilities, the Kansas City Plant in Missouri, the Mound Plant in Ohio, and the Pinellas Plant in Florida, that are dedicated primarily to nonnuclear activities and have unique manufacturing responsibilities. Some additional nonnuclear manufacturing activities are performed at the Rocky Flats Plant in Colorado, the Y-12 Plant in Tennessee, and the Pantex Plant in Texas. Descriptions of each plant and the activities they conduct are contained in appendix I of this report. In 1991, DOE began planning to reconfigure the nuclear weapons complex into one that is smaller, less diverse, and less expensive to operate. More specifically, DOE issued a reconfiguration study in January 1991 that set forth a detailed framework for making the complex smaller and more efficient. The study will lead to a complex-wide Programmatic Environmental Impact Statement (PEIS) on how best to reconfigure the complex. This statement is planned to be completed in late 1993. As part of the effort to analyze the reconfiguration, DOE's Assistant Secretary for Defense Programs directed the Albuquerque Operations Office in April 1991 to develop a nonnuclear consolidation plan to serve as input to the PEIS. There are a number of weaknesses in DOE's NCP. First, because the NCP's scope was limited to examining single-site consolidation alternatives, the decision to select Kansas City as the preferred option was made without analyzing other nonnuclear options. These options included down sizing and modernizing all facilities in place or maximizing consolidation by eliminating all nonnuclear sites and relocating their functions to a

  20. Single-Molecule Plasmon Sensing: Current Status and Future Prospects.

    Science.gov (United States)

    Taylor, Adam B; Zijlstra, Peter

    2017-08-25

    Single-molecule detection has long relied on fluorescent labeling with high quantum-yield fluorophores. Plasmon-enhanced detection circumvents the need for labeling by allowing direct optical detection of weakly emitting and completely nonfluorescent species. This review focuses on recent advances in single molecule detection using plasmonic metal nanostructures as a sensing platform, particularly using a single particle-single molecule approach. In the past decade two mechanisms for plasmon-enhanced single-molecule detection have been demonstrated: (1) by plasmonically enhancing the emission of weakly fluorescent biomolecules, or (2) by monitoring shifts of the plasmon resonance induced by single-molecule interactions. We begin with a motivation regarding the importance of single molecule detection, and advantages plasmonic detection offers. We describe both detection mechanisms and discuss challenges and potential solutions. We finalize by highlighting the exciting possibilities in analytical chemistry and medical diagnostics.

  1. Streamwise Fluctuations of Vortex Breakdown at High Reynolds Numbers

    National Research Council Canada - National Science Library

    Connelly, Jonathan S

    2006-01-01

    This thesis deals with the characterization of the dependence on the flow geometry of the stream wise fluctuations of the stagnation point of vortex breakdown in axisymmetric tubes and over delta wing aircraft...

  2. Axisymmetric Synthetic Jet Actuators with Large Streamwise Dimensions

    Czech Academy of Sciences Publication Activity Database

    Kordík, Jozef; Trávníček, Zdeněk

    2013-01-01

    Roč. 51, č. 12 (2013), s. 2862-2877 ISSN 0001-1452 R&D Projects: GA ČR GPP101/12/P556; GA ČR(CZ) GCP101/11/J019 Institutional support: RVO:61388998 Keywords : synthetic jet * synthetic jet actuator * resonance frequency Subject RIV: BK - Fluid Dynamics Impact factor: 1.165, year: 2013 http://arc.aiaa.org/doi/abs/10.2514/1.J052504

  3. Streamwise decrease of the 'unsteady' virtual velocity of gravel tracers

    Science.gov (United States)

    Klösch, Mario; Gmeiner, Philipp; Habersack, Helmut

    2017-04-01

    Gravel tracers are usually inserted and transported on top of the riverbed, before they disperse vertically and laterally due to periods of intense bedload, the passage of bed forms, lateral channel migration and storage on bars. Buried grains have a lower probability of entrainment, resulting in a reduction of overall mobility, and, on average, in a deceleration of the particles with distance downstream. As a consequence, the results derived from tracer experiments and their significance for gravel transport may depend on the time scale of the investigation period, complicating the comparison of results from different experiments. We developed a regression method, which establishes a direct link between the transport velocity and the unsteady flow variables to yield an 'unsteady' virtual velocity, while considering the tracer slowdown with distance downstream in the regression. For that purpose, the two parameters of a linear excess shear velocity formula (the critical shear velocity u*c and coefficient a) were defined as functions of the travelled distance since the tracer's insertion. Application to published RFID tracer data from the Mameyes River, Puerto Rico, showed that during the investigation period the critical shear velocity u*c of tracers representing the median bed particle diameter (0.11 m) increased from 0.36 m s-1 to 0.44 m s-1, while the coefficient a decreased from the dimensionless value of 4.22 to 3.53, suggesting a reduction of the unsteady virtual velocity at the highest shear velocity in the investigation period from 0.40 m s-1 to 0.08 m s-1. Consideration of the tracer slowdown improved the root mean square error of the calculated mean displacements of the median bed particle diameter from 8.82 m to 0.34 m. As in previous work these results suggest the need of considering the history of transport when deriving travel distances and travel velocities, depending on the aim of the tracer study. The introduced method now allows estimating the travel velocities directly after seeding (representing the velocity of sediment at the bed surface subject to actual transport), or the longer term transport of sediment, helping to understand the velocity of sediment transfer in river networks as a basis for catchment-wide river restoration plans in the course of the project 'HyMoCARES', which is co-financed by the European Regional Development Fund within the Alpine Space programme.

  4. Blade Sections in Streamwise Oscillations into Reverse Flow

    Science.gov (United States)

    2015-05-07

    diameter rigid lines glued to the surface of the plate (a) µ = 0.5 (b) µ = 1.0 Fig. 1. Iso -sweep angles [deg] over the rotor disk at µ = 0.5 and 1.0 (counter...edge to the trailing edge of the airfoil. Based on the oscillation periods of the three cases, the number of time steps per cycle is 25000 , 30000 and

  5. The DES Science Verification Weak Lensing Shear Catalogs

    International Nuclear Information System (INIS)

    Jarvis, M.

    2016-01-01

    We present weak lensing shear catalogs for 139 square degrees of data taken during the Science Verification (SV) time for the new Dark Energy Camera (DECam) being used for the Dark Energy Survey (DES). We describe our object selection, point spread function estimation and shear measurement procedures using two independent shear pipelines, IM3SHAPE and NGMIX, which produce catalogs of 2.12 million and 3.44 million galaxies respectively. We also detail a set of null tests for the shear measurements and find that they pass the requirements for systematic errors at the level necessary for weak lensing science applications using the SV data. Furthermore, we discuss some of the planned algorithmic improvements that will be necessary to produce sufficiently accurate shear catalogs for the full 5-year DES, which is expected to cover 5000 square degrees

  6. Supersymmetric electro-weak effects on gsub(μ)-2

    International Nuclear Information System (INIS)

    Yuan, T.C.; Arnowitt, R.; Chamseddine, A.H.; Nath, P.

    1984-01-01

    A model independent analysis of the supersymmetric electroweak contribution to gsub(μ)-2 is discussed within the framework of N=1 Supergravity unified theory. A detailed comparison with existing experiment of two models (R.G. and T.B.) is carried out. The supersymmetric electro-weak contributions are found to be characteristically different and generally larger than the electro-weak contributions of the standard theory, and in many cases significantly larger. Effects of the hidden sector and the photino mass dependence of gsub(μ)-2 are also investigated. Present data already eliminates some choices of parameters. Reduction of existing experimental errors by a factor of 3 will make contact with most R.G. models and by a factor of 10 with most T.B. models. (orig.)

  7. [Strength and weaknesses of the German digital health economy].

    Science.gov (United States)

    Leppert, Florian; Gerlach, Jan; Ostwald, Dennis A; Greiner, Wolfgang

    2017-07-26

    There are high expectations from digitalization of health care, ehealth and telemedicine. Nevertheless, the diffusion of these services falls short of expectations. This study analyses the strength and weaknesses of the German digital health economy. Thereby, we specially focus on small and medium-sized enterprises (SME). The study is based on a literature review, interviews of experts and a workshop. The digital health economy is influenced by a heterogeneous environment with both promotive and obstructive factors. One of the largest weaknesses results from a lack of business models. There is a lack of possibilities of reimbursement by the Statutory Health Insurance (SHI). In addition, private users only have a small willingness to pay for digital services. The large number of regulations makes the implementation even harder, especially for SMEs. Thus, the current environment hampers fast diffusion of digital services in the German health care market. © Georg Thieme Verlag KG Stuttgart · New York.

  8. "Weak quantum chaos" and its resistor network modeling.

    Science.gov (United States)

    Stotland, Alexander; Pecora, Louis M; Cohen, Doron

    2011-06-01

    Weakly chaotic or weakly interacting systems have a wide regime where the common random matrix theory modeling does not apply. As an example we consider cold atoms in a nearly integrable optical billiard with a displaceable wall (piston). The motion is completely chaotic but with a small Lyapunov exponent. The Hamiltonian matrix does not look like one taken from a Gaussian ensemble, but rather it is very sparse and textured. This can be characterized by parameters s and g which reflect the percentage of large elements and their connectivity, respectively. For g we use a resistor network calculation that has a direct relation to the semilinear response characteristics of the system, hence leading to a prediction regarding the energy absorption rate of cold atoms in optical billiards with vibrating walls.

  9. Open string T-duality in a weakly curved background

    International Nuclear Information System (INIS)

    Davidovic, Ljubica

    2016-01-01

    We consider a theory of an open string moving in a weakly curved background, composed of a constant metric and a linearly coordinate dependent Kalb-Ramond field with an infinitesimal field strength. We find its T-dual using the generalized Buscher procedure developed for the closed string moving in a weakly curved background, and the fact that solving the boundary conditions, the open string theory transforms to the effective closed string theory. So, T-dualizing the effective theory along all effective directions we obtain its T-dual theory and resume the open string theory which has such an effective theory. In this way we obtain the open string theory T-dual. (orig.)

  10. The transactional interpretation, counterfactuals, and weak values in quantum theory

    Science.gov (United States)

    Kastner, Ruth E.

    In recent years, a number of authors have studied pre- and post-selected quantum systems and associated time symmetry considerations. In this context, numerous paradoxes have arisen which raise questions about what can be inferred about such a system based on theoretically calculated quantities such as the Aharonov-Bergmann-Lebowitz (ABL) probabilities; and, more recently, "weak values"-time-symmetric quantities applicable to pre- and post-selected systems. This paper applies to some of these problems a time-symmetric interpretation of quantum theory: the "transactional interpretation" (TI) of Cramer, first proposed in 1980. The TI picture supports the conclusion that weak values are properly interpreted as multiple-time amplitudes rather than as generalized expectation values. It also prompts a stricter constraint on the counterfactual usage of the ABL rule than the consistency of the associated family of histories, which has previously been regarded as sufficient.

  11. Weak gravitational lensing towards high-precision cosmology

    International Nuclear Information System (INIS)

    Berge, Joel

    2007-01-01

    This thesis aims at studying weak gravitational lensing as a tool for high-precision cosmology. We first present the development and validation of a precise and accurate tool for measuring gravitational shear, based on the shapelets formalism. We then use shapelets on real images for the first time, we analyze CFHTLS images, and combine them with XMM-LSS data. We measure the normalisation of the density fluctuations power spectrum σ 8 , and the one of the mass-temperature relation for galaxy clusters. The analysis of the Hubble space telescope COSMOS field confirms our σ 8 measurement and introduces tomography. Finally, aiming at optimizing future surveys, we compare the individual and combined merits of cluster counts and power spectrum tomography. Our results demonstrate that next generation surveys will allow weak lensing to yield its full potential in the high-precision cosmology era. (author) [fr

  12. Weak turbulence theory for beam-plasma interaction

    Science.gov (United States)

    Yoon, Peter H.

    2018-01-01

    The kinetic theory of weak plasma turbulence, of which Ronald C. Davidson was an important early pioneer [R. C. Davidson, Methods in Nonlinear Plasma Theory, (Academic Press, New York, 1972)], is a venerable and valid theory that may be applicable to a large number of problems in both laboratory and space plasmas. This paper applies the weak turbulence theory to the problem of gentle beam-plasma interaction and Langmuir turbulence. It is shown that the beam-plasma interaction undergoes various stages of physical processes starting from linear instability, to quasilinear saturation, to mode coupling that takes place after the quasilinear stage, followed by a state of quasi-static "turbulent equilibrium." The long term quasi-equilibrium stage is eventually perturbed by binary collisional effects in order to bring the plasma to a thermodynamic equilibrium with increased entropy.

  13. WEAK EPISTEMIC MODALITY IN THE UK PARLIAMENTARY DISCOURSE

    Directory of Open Access Journals (Sweden)

    Milica Vukovic

    2014-11-01

    Full Text Available Discourse strategies of boosting and downtoning seem to play a paramount role in political discourse – persuading the electorate and defending one own’s position when ‘attacked’ liken the political battle to an actual war battle, whereby going on offensive and ducking into a trench, when the occasion demands it, may be linguistically effectuated through an array of linguistic means. Acting in defense in the context of political combat will be the focus of this paper, explored on a corpus taken from the 2010 UK parliamentary budget debate. Weak epistemic modality or hedging is studied through the use of weak epistemic adverbs, verbs, adjectives and nouns, its presence is measured through normalised frequencies and where possible compared to the BNC frequencies. The results point to a low presence of hedging in parliamentary discourse, both in comparison with strong epistemic modality in the same corpus and with the general everyday language.

  14. [Archaeology and criminology--Strengths and weaknesses of interdisciplinary cooperation].

    Science.gov (United States)

    Bachhiesl, Christian

    2015-01-01

    Interdisciplinary cooperation of archaeology and criminology is often focussed on the scientific methods applied in both fields of knowledge. In combination with the humanistic methods traditionally used in archaeology, the finding of facts can be enormously increased and the subsequent hermeneutic deduction of human behaviour in the past can take place on a more solid basis. Thus, interdisciplinary cooperation offers direct and indirect advantages. But it can also cause epistemological problems, if the weaknesses and limits of one method are to be corrected by applying methods used in other disciplines. This may result in the application of methods unsuitable for the problem to be investigated so that, in a way, the methodological and epistemological weaknesses of two disciplines potentiate each other. An example of this effect is the quantification of qualia. These epistemological reflections are compared with the interdisciplinary approach using the concrete case of the "Eulau Crime Scene".

  15. Can quantum probes satisfy the weak equivalence principle?

    Energy Technology Data Exchange (ETDEWEB)

    Seveso, Luigi, E-mail: luigi.seveso@unimi.it [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); Paris, Matteo G.A. [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); INFN, Sezione di Milano, I-20133 Milano (Italy)

    2017-05-15

    We address the question whether quantum probes in a gravitational field can be considered as test particles obeying the weak equivalence principle (WEP). A formulation of the WEP is proposed which applies also in the quantum regime, while maintaining the physical content of its classical counterpart. Such formulation requires the introduction of a gravitational field not to modify the Fisher information about the mass of a freely-falling probe, extractable through measurements of its position. We discover that, while in a uniform field quantum probes satisfy our formulation of the WEP exactly, gravity gradients can encode nontrivial information about the particle’s mass in its wavefunction, leading to violations of the WEP. - Highlights: • Can quantum probes under gravity be approximated as test-bodies? • A formulation of the weak equivalence principle for quantum probes is proposed. • Quantum probes are found to violate it as a matter of principle.

  16. General local stability criteria for stratified, weakly magnetized rotating systems

    International Nuclear Information System (INIS)

    Balbus, S.A.

    1995-01-01

    We consider the local stability of laminar differential rotation in a weakly magnetized plasma to adiabatic axisymmetric disturbances. Our assumptions are considerably less restrictive than those of previous analyses. The angular velocity need not have cylindrical isorotational surfaces, and a priori convective stability is not assumed. In an unmagnetized gas, stability under these circumstances would be governed by the Ho/iland criteria. These criteria change qualitatively when even a weak magnetic field is present. In a magnetized plasma, the new criteria for stability have the same general form exhibited by the purely hydrodynamical case, but with all angular momentum gradients replaced by angular velocity gradients. Our findings are in accord with those of Papaloizou ampersand Szuszkiewicz, who, using very different methods, considered the stability of iso-rotational field configurations. The results presented here thus point very generally to angular velocity gradients, not angular momentum gradients, as the fundamental stability discriminants in rotating astrophysical plasmas. copyright 1995 The American Astronomical Society

  17. Gauge theory of weak, electromagnetic and dual electromagnetic interactions

    International Nuclear Information System (INIS)

    Soln, J.

    1980-01-01

    An SU 2 x U 1 algebra, in addition to the ordinary electric charge, also establishes the existence of the dual electric charge. This is taken as an indication of the existence of dual electromagnetic interactions in nature. Here, the unification of weak, electromagnetic and dual electromagnetic interactions is performed. The Yang-Mills-type group which contains the electromagnetic, dual electromagnetic and weak currents is SUsub(L,2) x U 1 x U' 1 . The masses of vector mesons are generated through the Higgs-Kibble mechanism. A simple consistency requirement suggests that dual electromagnetism and ordinary electromagnetism have the same strengths, leading the theory to a rather good agreement with experiments. (author)

  18. Weak electricigens: A new avenue for bioelectrochemical research.

    Science.gov (United States)

    Doyle, Lucinda E; Marsili, Enrico

    2018-02-20

    Electroactivity appears to be a phylogenetically diverse trait independent of cell wall classification, with both Gram-negative and Gram-positive electricigens reported. While numerous electricigens have been observed, the majority of research focuses on a select group of highly electroactive species. Under favorable conditions, many microorganisms can be considered electroactive, either through their own mechanisms or exogenously-added mediators, producing a weak current. Such microbes should not be dismissed based on their modest electroactivity. Rather, they may be key to understanding what drives extracellular electron transfer in response to transient limitations of electron acceptor or donor, with implications for the study of pathogens and industrial bioprocesses. Due to their low electroactivity, such populations are difficult to grow in bioelectrochemical systems and characterise with electrochemistry. Here, a critical review of recent research on weak electricigens is provided, with a focus on the methodology and the overall relevance to microbial ecology and bioelectrochemical systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Renormalization Group in the uniqueness region weak Gibbsianity and convergence.

    CERN Document Server

    Bertini, L; Olivieri, E

    2004-01-01

    We analyze the block averaging transformation applied to lattice gas models with short range interaction in the uniqueness region below the critical temperature. %We discuss the %Gibbs property of the renormalized measure and the convergence of %renormalized potential under iteration of the map. We prove weak Gibbsianity of the renormalized measure and convergence of the renormalized potential in a weak sense. Since we are arbitrarily close to the coexistence region we have a diverging characteristic length of the system: the correlation length or the critical length for metastability, or both. Thus, to perturbatively treat the problem we have to use a scale--adapted expansion. Moreover, such a model below the critical temperature resembles a disordered system in presence of Griffiths' singularity. Then the cluster expansion that we use must be graded with its minimal scale length diverging when the coexistence line is approached.

  20. Reason, Action, and Weakness of the Will. A Semantic Approach

    Directory of Open Access Journals (Sweden)

    Tomás Barrero

    2010-09-01

    Full Text Available This paper develops some of Austin’s ideas on excuses, stressing their “dimensional” character and relating it to Searle’s distinction between intention-in-action and previous intention, in order to show that the original speech-act shaped distinction between weakness of the will and moral weakness can be embedded in a quite different theoretical framework such as Davidson’s, while Austin’s dimensional classification of actions cannot. Finally, the article analyzes how Grice’s critique of Davidson’s views on akrasia is more faithful to Austin and more radical in its conclusions concerning the justificatory aspect of reasons and the rational features of action.

  1. Calculations of some weakly bound diatomic molecular negative ions

    International Nuclear Information System (INIS)

    Li, Y.; Lin, C.D.

    1999-01-01

    We examine the existence of stable bound states of some diatomic molecular ions where the neutral molecule itself is either unbound or barely bound. Two bound states have been found for the HeH - ion even though HeH is known to be unbound. We have found no bound states for He 2 - even though 4 He 2 is known to have one bound state. The predicted binding energies for HeH - are of the order of 1 K and depend sensitively on the isotope combinations. Other weakly bound negative ions such as NeH - and ArH - have also been investigated. These weakly bound molecular ions are good candidates for cold collision experiments. copyright 1999 The American Physical Society

  2. Muscle weakness, afferent sensory dysfunction and exercise in knee osteoarthritis

    DEFF Research Database (Denmark)

    Roos, Ewa M.; Herzog, Walter; Block, Joel A

    2011-01-01

    Lower-extremity muscle strength and afferent sensory dysfunction, such as reduced proprioceptive acuity, are potentially modifiable putative risk factors for knee osteoarthritis (OA). Findings from current studies suggest that muscle weakness is a predictor of knee OA onset, while there is confli...... with previous knee injuries) are easily identified, and may benefit from exercise interventions to prevent or delay OA onset....... there is conflicting evidence regarding the role of muscle weakness in OA progression. In contrast, the literature suggests a role for afferent sensory dysfunction in OA progression but not necessarily in OA onset. The few pilot exercise studies performed in patients who are at risk of incident OA indicate...... a possibility for achieving preventive structure or load modifications. In contrast, large randomized controlled trials of patients with established OA have failed to demonstrate beneficial effects of strengthening exercises. Subgroups of individuals who are at increased risk of knee OA (such as those...

  3. Utilizing Weak Indicators to Detect Anomalous Behaviors in Networks

    Energy Technology Data Exchange (ETDEWEB)

    Egid, Adin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-01

    We consider the use of a novel weak in- dicator alongside more commonly used weak indicators to help detect anomalous behavior in a large computer network. The data of the network which we are studying in this research paper concerns remote log-in information (Virtual Private Network, or VPN sessions) from the internal network of Los Alamos National Laboratory (LANL). The novel indicator we are utilizing is some- thing which, while novel in its application to data science/cyber security research, is a concept borrowed from the business world. The Her ndahl-Hirschman Index (HHI) is a computationally trivial index which provides a useful heuristic for regulatory agencies to ascertain the relative competitiveness of a particular industry. Using this index as a lagging indicator in the monthly format we have studied could help to detect anomalous behavior by a particular or small set of users on the network.

  4. Faddeev-Yakubovsky technique for weakly bound systems

    International Nuclear Information System (INIS)

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

    2011-01-01

    Nature shows the existence of weakly bound systems in different sectors, ranging from atomic to nuclear physics. Few-body systems with large scattering length exhibit universal features, which are independent of the details of the interaction, and thus are common to nuclear and atomic systems. Very different methods are used to study the properties of few-body systems, from Faddeev methods to diagonalization methods that rely on an expansion of the wave functions in a complete basis set, like e.g. hyper-spherical harmonics and no core shell model. In this talk we present Faddeev-Yakubovsky method to study the three- and four-body bound states in momentum space. To show the efficiency and accuracy of the method we investigate the three- and four-boson weakly bound states in unitary limit (for zero two-body binding) and we present a pretty complete picture of universality. (author)

  5. Weak coupling polaron and Landau-Zener scenario: Qubits modeling

    Science.gov (United States)

    Jipdi, M. N.; Tchoffo, M.; Fokou, I. F.; Fai, L. C.; Ateuafack, M. E.

    2017-06-01

    The paper presents a weak coupling polaron in a spherical dot with magnetic impurities and investigates conditions for which the system mimics a qubit. Particularly, the work focuses on the Landau-Zener (LZ) scenario undergone by the polaron and derives transition coefficients (transition probabilities) as well as selection rules for polaron's transitions. It is proven that, the magnetic impurities drive the polaron to a two-state superposition leading to a qubit structure. We also showed that the symmetry deficiency induced by the magnetic impurities (strong magnetic field) yields to the banishment of transition coefficients with non-stacking states. However, the transition coefficients revived for large confinement frequency (or weak magnetic field) with the orbital quantum numbers escorting transitions. The polaron is then shown to map a qubit independently of the number of relevant states with the transition coefficients lifted as LZ probabilities and given as a function of the electron-phonon coupling constant (Fröhlich constant).

  6. An Integration Algorithm for Bistatic Radar Weak Target Detection

    Directory of Open Access Journals (Sweden)

    Chang Jiajun

    2016-01-01

    Full Text Available The bistatic radar weak target detection problem is considered in this paper. An effective way to detect weak target is the long time integration. However, range migration (RM will occur due to the high speed. Without knowing the target motion parameters, a long time integration algorithm for bistatic radar is proposed in this paper. Firstly, the algorithm utilizes second-order keystone transform (SKT to remove range curvature. Then the quadratic phase term is compensated by the estimated acceleration. After that, SKT is used once more and the Doppler ambiguity phase term compensation is performed. At last, the target energy is integrated via FT. Simulations are provided to show the validity of the proposed algorithm in the end.

  7. Proceedings of Summer Institute on Particle Physics: the weak interaction

    International Nuclear Information System (INIS)

    Mosher, A.

    1981-01-01

    The SLAC Summer Institute on Particle Physics held its eighth session on July 28-August 8, 1980, and the focus of the meeting was The Weak Interaction. Following the now traditional format, the first seven days of the Institute were spent with the mornings given to pedagogic lectures on the experimental and theoretical foundations of the topic. This year included a very stimulating and successful series on the physics of particle detectors. In the afternoons were seminars on the various experimental tools being designed or constructed to further probe the Weak Interaction, followed by lively discussion of the morning's lectures. Again, following the usual format, the school led into a three-day topical conference at which the most recent theoretical and experimental results were presented and discussed. Abstracts of twenty-seven items from the Institute were prepared separately for the data base

  8. Non-leptonic weak decay of hadrons and chiral symmetry

    International Nuclear Information System (INIS)

    Suzuki, Katsuhiko

    2000-01-01

    We review the non-leptonic weak decay of hyperons and ΔI=1/2 rule with a special emphasis on the role of chiral symmetry. The soft-pion theorem provides a powerful framework to understand the origin of ΔI=1/2 rule qualitatively. However, quantitative description is still incomplete in any model of the hadrons. Naive chiral perturbation theory cannot explain the parity-conserving and violating amplitudes simultaneously, and convergence of the chiral expansion seems to be worse. We demonstrate how the non-leptonic weak decay amplitudes are sensitive to the quark-pair correlation in the baryons, and show the importance of the strong quark correlation in the spin-0 channel to reproduce the experimental data. We finally remark several related topics. (author)

  9. Weak and strong coupling equilibration in nonabelian gauge theories

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, Liam [Physics Department, Theory Unit, CERN,CH-1211 Genève 23 (Switzerland); Kurkela, Aleksi [Physics Department, Theory Unit, CERN,CH-1211 Genève 23 (Switzerland); Faculty of Science and Technology, University of Stavanger,4036 Stavanger (Norway); Romatschke, Paul [Department of Physics, 390 UCB, University of Colorado at Boulder,Boulder, CO (United States); Center for Theory of Quantum Matter, University of Colorado,Boulder, Colorado 80309 (United States); Schee, Wilke van der [Center for Theoretical Physics, MIT,Cambridge, MA 02139 (United States); Zhu, Yan [Department of Physics, University of Jyväskyla, P.O. Box 35, FI-40014 University of Jyväskylä (Finland); Helsinki Institute of Physics,P.O. Box 64, 00014 University of Helsinki (Finland)

    2016-04-06

    We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.

  10. Weak and strong coupling equilibration in nonabelian gauge theories

    CERN Document Server

    Keegan, Liam; Romatschke, Paul; van der Schee, Wilke; Zhu, Yan

    2016-01-01

    We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.

  11. Formal identity of gravitational and weakly interacting recession

    International Nuclear Information System (INIS)

    Muheim, J.T.

    1982-01-01

    The author discusses the construction of models using the five elementary constants esub(s), h/2π, G, c and ksub(B) which can produce a macro or micro world with exacticity. All physical processes in nature determine the gravitational universe recession. A diagram is presented comparing the gravitational and weakly interacting recession. The Big-Bang model is discussed. (A.N.K.)

  12. Gapped boundary phases of topological insulators via weak coupling

    Science.gov (United States)

    Seiberg, Nathan; Witten, Edward

    2016-12-01

    The standard boundary state of a topological insulator in 3 + 1 dimensions has gapless charged fermions. We present model systems that reproduce this standard gapless boundary state in one phase, but also have gapped phases with topological order. Our models are weakly coupled and all the dynamics is explicit. We rederive some known boundary states of topological insulators and construct new ones. Consistency with the standard spin/charge relation of condensed matter physics places a nontrivial constraint on models.

  13. Quantum protocol for cheat-sensitive weak coin flipping.

    Science.gov (United States)

    Spekkens, R W; Rudolph, Terry

    2002-11-25

    We present a quantum protocol for the task of weak coin flipping. We find that, for one choice of parameters in the protocol, the maximum probability of a dishonest party winning the coin flip if the other party is honest is 1/sqrt[2]. We also show that if parties restrict themselves to strategies wherein they cannot be caught cheating, their maximum probability of winning can be even smaller. As such, the protocol offers additional security in the form of cheat sensitivity.

  14. Large thermomagnetic effects in weakly disordered Heisenberg chains

    OpenAIRE

    Shimshoni, E.; Rasch, D.; Jung, P.; Sologubenko, A. V.; Rosch, A.

    2008-01-01

    The interplay of different scattering mechanisms can lead to novel effects in transport. We show theoretically that the interplay of weak impurity and Umklapp scattering in spin-1/2 chains leads to a pronounced dip in the magnetic field dependence of the thermal conductivity $\\kappa$ at a magnetic field $B \\sim T$. In sufficiently clean samples, the reduction of the magnetic contribution to heat transport can easily become larger than 50% and the effect is predicted to exist even in samples w...

  15. Weak Memory Models: Balancing Definitional Simplicity and Implementation Flexibility

    OpenAIRE

    Zhang, Sizhuo; Vijayaraghavan, Muralidaran; Arvind

    2017-01-01

    The memory model for RISC-V, a newly developed open source ISA, has not been finalized yet and thus, offers an opportunity to evaluate existing memory models. We believe RISC-V should not adopt the memory models of POWER or ARM, because their axiomatic and operational definitions are too complicated. We propose two new weak memory models: WMM and WMM-S, which balance definitional simplicity and implementation flexibility differently. Both allow all instruction reorderings except overtaking of...

  16. Characteristics of langmuir probe in low temperature, weakly magnetized plasmas

    International Nuclear Information System (INIS)

    Wu Liqi; Liu Wandong; Xie Jinlin; Yu Zhi; Lan Tao; Ouyang Liang; Wang Yi; Zhao Kai

    2003-01-01

    The systematic Langmuir probe measurements for a weakly magnetized plasma have been carried out in the Linear Magnetized Plasma Device for different magnetic fields. By comparing the ion current density of probes with different sizes, the sheath thickness can be evaluated. It is found that while the ratio of cylindrical probe's dimension to ion Larmor radius is not more than 2, the model of probe for non-magnetized plasma is still applicable

  17. Two-dimensional weak pseudomanifolds on eight vertices

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    whose 2-simplices are abv, acv, bcv, xyv, yzv, xzv and those of M other than τ1 and τ2. Observe that we get P33 from P2 and P39 from T1 by this process. From these definitions one gets the following: PROPOSITION 3.3. Let ˜M be obtained from M by identifying two vertices u and v. (a) If M is a (weak) pseudomanifold, then ...

  18. Strong and weak hydrogen bonds in drug–DNA complexes

    Indian Academy of Sciences (India)

    The dataset was extracted from the protein data bank (PDB). The analysis was performed with an in-house software, hydrogen bond analysis tool (HBAT). In addition to strong hydrogen bonds such as O−H···O and N−H···O, the ubiquitous presence of weak hydrogen bonds such as C−H···O is implicated in molecular ...

  19. Description of intruded states in a weak-coupling basis

    International Nuclear Information System (INIS)

    Arenas Peris, G.E.

    1989-01-01

    The systematics of intruder states is described in terms of a particle-hole weak-coupling basis, the first-order correction being then reduced to the monopole component of the interaction. The necessary matrix elements can be obtained from experimental data by using a model-consistent method. Calculations are performed for intruder states in the lead region as well as for the Zr isotopes. The agreement with the experimental data is striking in both cases. (Author) [es

  20. 3D weak lensing with spin wavelets on the ball

    Science.gov (United States)

    Leistedt, Boris; McEwen, Jason D.; Kitching, Thomas D.; Peiris, Hiranya V.

    2015-12-01

    We construct the spin flaglet transform, a wavelet transform to analyze spin signals in three dimensions. Spin flaglets can probe signal content localized simultaneously in space and frequency and, moreover, are separable so that their angular and radial properties can be controlled independently. They are particularly suited to analyzing cosmological observations such as the weak gravitational lensing of galaxies. Such observations have a unique 3D geometrical setting since they are natively made on the sky, have spin angular symmetries, and are extended in the radial direction by additional distance or redshift information. Flaglets are constructed in the harmonic space defined by the Fourier-Laguerre transform, previously defined for scalar functions and extended here to signals with spin symmetries. Thanks to various sampling theorems, both the Fourier-Laguerre and flaglet transforms are theoretically exact when applied to bandlimited signals. In other words, in numerical computations the only loss of information is due to the finite representation of floating point numbers. We develop a 3D framework relating the weak lensing power spectrum to covariances of flaglet coefficients. We suggest that the resulting novel flaglet weak lensing estimator offers a powerful alternative to common 2D and 3D approaches to accurately capture cosmological information. While standard weak lensing analyses focus on either real- or harmonic-space representations (i.e., correlation functions or Fourier-Bessel power spectra, respectively), a wavelet approach inherits the advantages of both techniques, where both complicated sky coverage and uncertainties associated with the physical modeling of small scales can be handled effectively. Our codes to compute the Fourier-Laguerre and flaglet transforms are made publicly available.