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Sample records for suppressed order parameter

  1. Coexistence of superconductivity and magnetism in Ca{sub 1-x}Na{sub x}Fe{sub 2}As{sub 2}. Universal suppression of the magnetic order parameter in 122 iron pnictides

    Energy Technology Data Exchange (ETDEWEB)

    Materne, Philipp; Kamusella, Sirko; Sarkar, Rajib; Klauss, Hans-Henning [IFP, TU Dresden, 01062 Dresden (Germany); Harnagea, Luminita [IFW Dresden, Postfach 270016, 01171 Dresden (Germany); Wurmehl, Sabine; Buechner, Bernd [IFP, TU Dresden, 01062 Dresden (Germany); IFW Dresden, Postfach 270016, 01171 Dresden (Germany); Luetkens, Hubertus [PSI, 5232 Villigen (Switzerland); Timm, Carsten [ITP, TU Dresden, 01062 Dresden (Germany)

    2016-07-01

    We examined Ca{sub 1-x}Na{sub x}Fe{sub 2}As{sub 2} single crystals with x=0.00, 0.35, 0.50, and 0.67 by means of muon spin relaxation and Moessbauer spectroscopy to investigate the electronic and structural properties of these compounds. CaFe{sub 2}As{sub 2} is a semimetal, which shows spin density wave order below 167 K. By hole doping via Ca→Na substitution, the magnetic order is suppressed and superconductivity emerges with T{sub c}∼34K at optimal doping including a substitution level region where both phases coexist. We have studied the interplay of order parameters in this coexistence region and found nanoscopic coexistence of both order parameters. This is proven by a reduction of the magnetic order parameter by 7% below the superconducting transition temperature. We present a systematic correlation between the reduction of the magnetic order parameter and the ratio of the transition temperatures, T{sub c}/T{sub N}, for the 122 family of the iron-based superconductors.

  2. Hybrid superconducting-magnetic memory device using competing order parameters.

    Science.gov (United States)

    Baek, Burm; Rippard, William H; Benz, Samuel P; Russek, Stephen E; Dresselhaus, Paul D

    2014-05-28

    In a hybrid superconducting-magnetic device, two order parameters compete, with one type of order suppressing the other. Recent interest in ultra-low-power, high-density cryogenic memories has spurred new efforts to simultaneously exploit superconducting and magnetic properties so as to create novel switching elements having these two competing orders. Here we describe a reconfigurable two-layer magnetic spin valve integrated within a Josephson junction. Our measurements separate the suppression in the superconducting coupling due to the exchange field in the magnetic layers, which causes depairing of the supercurrent, from the suppression due to the stray magnetic field. The exchange field suppression of the superconducting order parameter is a tunable and switchable behaviour that is also scalable to nanometer device dimensions. These devices demonstrate non-volatile, size-independent switching of Josephson coupling, in magnitude as well as phase, and they may enable practical nanoscale superconducting memory devices.

  3. Deductive multiscale simulation using order parameters

    Science.gov (United States)

    Ortoleva, Peter J.

    2017-05-16

    Illustrative embodiments of systems and methods for the deductive multiscale simulation of macromolecules are disclosed. In one illustrative embodiment, a deductive multiscale simulation method may include (i) constructing a set of order parameters that model one or more structural characteristics of a macromolecule, (ii) simulating an ensemble of atomistic configurations for the macromolecule using instantaneous values of the set of order parameters, (iii) simulating thermal-average forces and diffusivities for the ensemble of atomistic configurations, and (iv) evolving the set of order parameters via Langevin dynamics using the thermal-average forces and diffusivities.

  4. A continuum order parameter for deconfinement

    International Nuclear Information System (INIS)

    Roberts, C.D.

    1997-01-01

    Dyson-Schwinger equations are presented as a non-perturbative tool for the study and modeling of QCD at finite-T. An order parameter for deconfinement, applicable for both light and heavy quarks, is introduced. In a simple Dyson-Schwinger equation model of two-flavor QCD, coincident, 2nd-order chiral symmetry restoration and deconfinement transitions occur at T ∼ 150 MeV, with the same critical exponent, Β ∼ 0.33

  5. An order parameter for networks of automata

    International Nuclear Information System (INIS)

    Flyvbjerg, H.

    1988-05-01

    An exact polynomial equation is given for the size of the stable core of networks of automata with random connections. When the connectivity K of a network equals 1, 2, 3, 4, or 5 this equation is exactly solvable. It is found that the size of the stable core is an order parameter for a phase transition well known from Kauffman's model. A new derivation of critical parameter values follows. The phase structure is found to be independent of the updating scheme used in the dynamical law for the network. (orig.)

  6. Universal features of the order-parameter fluctuations

    International Nuclear Information System (INIS)

    Botet, R.

    1998-07-01

    The universal scaling laws of order parameter fluctuations in any system in which the second-order critical behavior can be identified are discussed. These scaling laws can be derived rigorously for equilibrium systems when combined with the finite-size scaling analysis. The relation between order parameter, criticality and scaling law of fluctuations has been established and the connexion between the scaling function and the critical exponents has been found. (author)

  7. Determination of the Antiferroquadrupolar Order Parameters in UPd3

    Science.gov (United States)

    Walker, H. C.; McEwen, K. A.; McMorrow, D. F.; Wilkins, S. B.; Wastin, F.; Colineau, E.; Fort, D.

    2006-09-01

    By combining accurate heat capacity and x-ray resonant scattering results we have resolved the long standing question regarding the nature of the quadrupolar ordered phases in UPd3. The order parameter of the highest temperature quadrupolar phase has been uniquely determined to be antiphase Qzx in contrast to the previous conjecture of Qx2-y2. The azimuthal dependence of the x-ray scattering intensity from the quadrupolar superlattice reflections indicates that the lower temperature phases are described by a superposition of order parameters. The heat capacity features associated with each of the phase transitions characterize their order, which imposes restrictions on the matrix elements of the quadrupolar operators.

  8. Order parameter analysis of synchronization transitions on star networks

    Science.gov (United States)

    Chen, Hong-Bin; Sun, Yu-Ting; Gao, Jian; Xu, Can; Zheng, Zhi-Gang

    2017-12-01

    The collective behaviors of populations of coupled oscillators have attracted significant attention in recent years. In this paper, an order parameter approach is proposed to study the low-dimensional dynamical mechanism of collective synchronizations, by adopting the star-topology of coupled oscillators as a prototype system. The order parameter equation of star-linked phase oscillators can be obtained in terms of the Watanabe-Strogatz transformation, Ott-Antonsen ansatz, and the ensemble order parameter approach. Different solutions of the order parameter equation correspond to the diverse collective states, and different bifurcations reveal various transitions among these collective states. The properties of various transitions in the star-network model are revealed by using tools of nonlinear dynamics such as time reversibility analysis and linear stability analysis.

  9. Solliton-like order parameter distributions in the critical region

    Directory of Open Access Journals (Sweden)

    A.V.Babich

    2006-01-01

    Full Text Available Some exact one-component order parameter distributions for the Michelson thermodynamic potential are obtained. The phase transition of second kind in Ginzburg-Landau type model is investigated. The exact partial distribution of the order parameter in the form of Jakobi elliptic function is obtained. The energy of this distribution is lower at some temperature interval than for the best known models.

  10. Symmetry-adapted order parameters and free energies for solids undergoing order-disorder phase transitions

    Science.gov (United States)

    Natarajan, Anirudh Raju; Thomas, John C.; Puchala, Brian; Van der Ven, Anton

    2017-10-01

    Accurate thermodynamic descriptions are a key ingredient to kinetic theories that describe the mesoscale evolution of a solid undergoing ordering or decomposition reactions. We introduce a general approach to identify order parameters for order-disorder reactions and to calculate first-principles free-energy surfaces as a function of these order parameters. The symmetry of the disordered phase is used to formulate order parameters as linear combinations of sublattice compositions of a reference supercell. The order parameters can distinguish the disordered phase from the symmetrically equivalent variants of a particular ordered phase. A thermodynamic formalism is then developed to rigorously define a coarse-grained free energy as a function of order parameters. Bias potentials are added to the potential energy to enable sampling of the unstable regions within the order-parameter domain. Monte Carlo sampling in the biased ensemble is combined with free-energy integration to calculate high-temperature free energies. We illustrate the approach by analyzing the free energies of order-disorder transitions on a two-dimensional triangular lattice and in the technologically important Ni-Al alloy.

  11. Order parameter analysis of seismicity of the Mexican Pacific coast

    Science.gov (United States)

    Ramírez-Rojas, A.; Flores-Márquez, E. L.

    2013-05-01

    The natural time domain has shown to be an important tool to obtain relevant information hidden in time series of complex systems not easily obtainable by means of standard analysis methods. By assuming that tectonism is a complex system and that earthquakes are similar to a phase transition, it is possible to define an order parameter for seismicity in the context of the natural time domain. In this work we analyze the statistical features of the order parameter (OP) computed for the seismic Mexican catalog spanning from 1974 to 2012. We found that in four out of the six regions the pdf of the order parameter fluctuations is similar with that earlier reported by other authors, but in two of these regions noticeable differences are identified. Also, except for Michoacán, the scaled pdfs analysis of all regions collapse on a universal curve with non-Gaussian tails.

  12. Testing for one Generalized Linear Single Order Parameter

    DEFF Research Database (Denmark)

    Ellegaard, Niels Langager; Christensen, Tage Emil; Dyre, Jeppe

    work the order parameter may be chosen to have a non-exponential relaxation. The model predictions contradict the general consensus of the properties of viscous liquids in two ways: (i) The model predicts that following a linear isobaric temperature step, the normalized volume and entalpy relaxation......We examine a linear single order parameter model for thermoviscoelastic relaxation in viscous liquids, allowing for a distribution of relaxation times. In this model the relaxation of volume and entalpy is completely described by the relaxation of one internal order parameter. In contrast to prior...... functions are identical. This assumption conflicts with some (but not all) reports, utilizing the Tool-Narayanaswamy formalism to extrapolate from non-linear measurements to the linear regime. (ii) The model predicts that the theoretical "linear Prigogine-Defay" ratio is one. This ratio has never been...

  13. Single-order-parameter description of glass-forming liquids

    DEFF Research Database (Denmark)

    Ellegaard, Niels Langager; Christensen, Tage Emil; Christiansen, Peder Voetmann

    2007-01-01

    Thermoviscoelastic linear-response functions are calculated from the master equation describing viscous liquid inherent dynamics. From the imaginary parts of the frequency-dependent isobaric specific heat, isothermal compressibility, and isobaric thermal expansion coefficient, we define a "linear...... dynamic Prigogine-Defay ratio" with the property that if this ratio is unity at one frequency, then it is unity at all frequencies. This happens if and only if there is a single-order-parameter description of the thermoviscoelastic linear responses via an order parameter which may be nonexponential...

  14. Dynamics of order parameters for globally coupled oscillators

    DEFF Research Database (Denmark)

    De Monte, Silvia; D'ovidio, Francesco

    2002-01-01

    The equation of motion for the centroid of globally coupled oscillators with natural frequency mismatch is obtained through a series expansion in order parameters, valid for any population size. In the case of strong coupling and narrow-frequency distribution the first-order expansion (correspond......The equation of motion for the centroid of globally coupled oscillators with natural frequency mismatch is obtained through a series expansion in order parameters, valid for any population size. In the case of strong coupling and narrow-frequency distribution the first-order expansion...... (corresponding to a system where the centroid is coupled to a second macroscopic variable), predicts transient and asymptotic properties of the dynamics of the centroid. Phase transitions appear as macroscopic bifurcations. Collective properties arising in the transient, and particularly critical perturbations...

  15. Determination of the antiferroquadrupolar order parameters in UPd(3).

    Science.gov (United States)

    Walker, H C; McEwen, K A; McMorrow, D F; Wilkins, S B; Wastin, F; Colineau, E; Fort, D

    2006-09-29

    By combining accurate heat capacity and x-ray resonant scattering results we have resolved the long standing question regarding the nature of the quadrupolar ordered phases in UPd(3). The order parameter of the highest temperature quadrupolar phase has been uniquely determined to be antiphase Q{zx} in contrast to the previous conjecture of Q{x{2}-y{2}}. The azimuthal dependence of the x-ray scattering intensity from the quadrupolar superlattice reflections indicates that the lower temperature phases are described by a superposition of order parameters. The heat capacity features associated with each of the phase transitions characterize their order, which imposes restrictions on the matrix elements of the quadrupolar operators.

  16. Anyonic order parameters for discrete gauge theories on the lattice

    NARCIS (Netherlands)

    Bais, F.A.; Romers, J.C.

    2009-01-01

    We present a new family of gauge invariant non-local order parameters Delta(A)(alpha) for (non-abelian) discrete gauge theories on a Euclidean lattice, which are in one-to-one correspondence with the excitation spectrum that follows from the representation theory of the quantum double D(H) of the

  17. First Measurements of Higher Order Optics Parameters in the LHC

    CERN Document Server

    Vanbavinckhove, G; Bartolini, R; Calaga, R; Giovannozzi, M; Maclean, E H; Miyamoto, R; Schmidt, F; Tomas, R

    2011-01-01

    Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these pa- rameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed sim- ulations are compared to the measurements together with discussions on the measurement limitations.

  18. Riccati-parameter solutions of nonlinear second-order ODEs

    International Nuclear Information System (INIS)

    Reyes, M A; Rosu, H C

    2008-01-01

    It has been proven by Rosu and Cornejo-Perez (Rosu and Cornejo-Perez 2005 Phys. Rev. E 71 046607, Cornejo-Perez and Rosu 2005 Prog. Theor. Phys. 114 533) that for some nonlinear second-order ODEs it is a very simple task to find one particular solution once the nonlinear equation is factorized with the use of two first-order differential operators. Here, it is shown that an interesting class of parametric solutions is easy to obtain if the proposed factorization has a particular form, which happily turns out to be the case in many problems of physical interest. The method that we exemplify with a few explicitly solved cases consists in using the general solution of the Riccati equation, which contributes with one parameter to this class of parametric solutions. For these nonlinear cases, the Riccati parameter serves as a 'growth' parameter from the trivial null solution up to the particular solution found through the factorization procedure

  19. One-Sign Order Parameter in Iron Based Superconductor

    Directory of Open Access Journals (Sweden)

    Bernd Büchner

    2012-03-01

    Full Text Available The onset of superconductivity at the transition temperature is marked by the onset of order, which is characterized by an energy gap. Most models of the iron-based superconductors find a sign-changing (s± order parameter [1–6], with the physical implication that pairing is driven by spin fluctuations. Recent work, however, has indicated that LiFeAs has a simple isotropic order parameter [7–9] and spin fluctuations are not necessary [7,10], contrary to the models [1–6]. The strength of the spin fluctuations has been controversial [11,12], meaning that the mechanism of superconductivity cannot as yet be determined. We report the momentum dependence of the superconducting energy gap, where we find an anisotropy that rules out coupling through spin fluctuations and the sign change. The results instead suggest that orbital fluctuations assisted by phonons [13,14] are the best explanation for superconductivity.

  20. Magnetically driven suppression of nematic order in an iron-based superconductor.

    Science.gov (United States)

    Avci, S; Chmaissem, O; Allred, J M; Rosenkranz, S; Eremin, I; Chubukov, A V; Bugaris, D E; Chung, D Y; Kanatzidis, M G; Castellan, J-P; Schlueter, J A; Claus, H; Khalyavin, D D; Manuel, P; Daoud-Aladine, A; Osborn, R

    2014-05-22

    A theory of superconductivity in the iron-based materials requires an understanding of the phase diagram of the normal state. In these compounds, superconductivity emerges when stripe spin density wave (SDW) order is suppressed by doping, pressure or atomic disorder. This magnetic order is often pre-empted by nematic order, whose origin is yet to be resolved. One scenario is that nematic order is driven by orbital ordering of the iron 3d electrons that triggers stripe SDW order. Another is that magnetic interactions produce a spin-nematic phase, which then induces orbital order. Here we report the observation by neutron powder diffraction of an additional fourfold-symmetric phase in Ba1-xNaxFe2As2 close to the suppression of SDW order, which is consistent with the predictions of magnetically driven models of nematic order.

  1. Suppression of Higher-Order Modes by Segmented Core Doping in Rod-Type Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Poli, Federica; Lægsgaard, Jesper; Passaro, Davide

    2009-01-01

    in the refractive index value. After applying a scalar step-index model for a first parameter optimization of the proposed design, a full-vector modal solver based on the finite element method has been exploited to analyze the guided mode overlap and effective area for the most promising fibers identified. Finally......Abstract—A large mode area Yb-doped rod-type photonic crystal fiber design with a low refractive index ring in the core is proposed to provide an improved suppression of the first higher-order mode compared to the case of uniform core doping, in a way which is more robust against fluctuations......, a spatial and spectral amplifier model has been considered to study the gain competition among the fundamental and the first higher-order mode guided in the Yb-doped rod-type fibers. Results have demonstrated the effectiveness of the low refractive index ring in suppressing the higher-order mode, thus...

  2. Nodes in an alternatively defined order parameter in HTSC

    Science.gov (United States)

    Nettel, Stephen

    2008-10-01

    In a previous study the BCS wave function was generalized to include the motion of the center-of-mass of Cooper pairs. It was found that the Ginsburg-Landau order parameter could be identified with a wave function describing this motion. Here attention is focussed on the effects of replacing free electron orbitals by Bloch waves. In the copper oxides, where the Fermi surface lies contiguous to the Brillouin zone boundary, and with pairs coupled by soft phonon modes, limitations on the wave vectors associated with the center-of-mass coordinates are found. These limitations lead to nodes in the Fourier transform of the Ginsburg-Landau order parameter. Possible relevance of the nodes to the more recently discovered properties of high TC superconductors is discussed.

  3. Nodes in an alternatively defined order parameter in HTSC

    International Nuclear Information System (INIS)

    Nettel, Stephen

    2008-01-01

    In a previous study the BCS wave function was generalized to include the motion of the center-of-mass of Cooper pairs. It was found that the Ginsburg-Landau order parameter could be identified with a wave function describing this motion. Here attention is focussed on the effects of replacing free electron orbitals by Bloch waves. In the copper oxides, where the Fermi surface lies contiguous to the Brillouin zone boundary, and with pairs coupled by soft phonon modes, limitations on the wave vectors associated with the center-of-mass coordinates are found. These limitations lead to nodes in the Fourier transform of the Ginsburg-Landau order parameter. Possible relevance of the nodes to the more recently discovered properties of high T C superconductors is discussed

  4. Glass-forming liquids: one or more "order" parameters"

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Christensen, Tage Emil; Jakobsen, Bo

    2008-01-01

    as a few exceptions, are briefly presented. Finally, we briefly discuss a new conjecture according to which experiments at varying temperature and pressure follow the density scaling expression for the relaxation time, τ = F(ρ^x/T ) (ρ and T are density and temperature), if and only if the liquid......We first summarize the classical arguments that the vast majority of glass-forming liquids require more than one ‘order' parameter for their description. Critiques against this conventional wisdom are then presented, and it is argued that the matter deserves to be reconsidered in the light...... that a description with a single "order" parameter applies to a good approximation whenever thermal equilibrium fluctuations of fundamental variables like energy and pressure are strongly correlated. Results from computer simulations showing that this is the case for a number of simple glass-forming liquids, as well...

  5. Spin-label Order Parameter Calibrations for Slow Motion

    DEFF Research Database (Denmark)

    Marsh, Derek

    2018-01-01

    Calibrations are given to extract orientation order parameters from pseudo-powder electron paramagnetic resonance line shapes of 14N-nitroxide spin labels undergoing slow rotational diffusion. The nitroxide z-axis is assumed parallel to the long molecular axis. Stochastic-Liouville simulations...... (Formula presented.) which characterizes fluctuations of the long molecular axis. This results in empirical expressions for order parameter and isotropic hyperfine coupling: (Formula presented.) and (Formula presented.), respectively. Values of the calibration constants (Formula presented.), (Formula...... presented.), (Formula presented.), (Formula presented.) and (Formula presented.) are given for different values of (Formula presented.) in fast and slow motional regimes. The calibrations are relatively insensitive to anisotropy of rotational diffusion (Formula presented.), and corrections are less...

  6. Order parameter model for unstable multilane traffic flow

    OpenAIRE

    Lubashevsky, Ihor A.; Mahnke, Reinhard

    1999-01-01

    We discuss a phenomenological approach to the description of unstable vehicle motion on multilane highways that explains in a simple way the observed sequence of the phase transitions "free flow -> synchronized motion -> jam" as well as the hysteresis in the transition "free flow synchronized motion". We introduce a new variable called order parameter that accounts for possible correlations in the vehicle motion at different lanes. So, it is principally due to the "many-body" effects in the ...

  7. Simple empirical order parameter for a first-order quantum phase transition in atomic nuclei.

    Science.gov (United States)

    Bonatsos, Dennis; McCutchan, E A; Casten, R F; Casperson, R J

    2008-04-11

    A simple, empirical, easy-to-measure effective order parameter of a first-order phase transition in atomic nuclei is presented, namely, the ratio of the energies of the first excited 6+ and 0+ states, distinguishing between first- and second-order transitions, and taking on a special value in the critical region, as data in Nd-Dy show. In the large NB limit of the interacting boson approximation model, a repeating degeneracy between alternate yrast and successive 0+ states is found in the critical region around the line of a first-order phase transition, pointing to a possible underlying symmetry.

  8. Ordering dynamics of microscopic models with nonconserved order parameter of continuous symmetry

    DEFF Research Database (Denmark)

    Zhang, Z.; Mouritsen, Ole G.; Zuckermann, Martin J.

    1993-01-01

    from a disordered phase to an orientationally ordered phase of continuous symmetry. The Lebwohl-Lasher model accounts for the orientational ordering properties of the nematic-isotropic transition in liquid crystals and the Heisenberg model for the ferromagnetic-paramagnetic transition in magnetic...... crystals. For both models, which have a nonconserved order parameter, it is found that the linear scale, R(t), of the evolving order, following quenches to below the transition temperature, grows at late times in an effectively algebraic fashion, R(t)∼tn, with exponent values which are strongly temperature...

  9. Thermal nanostructure: An order parameter multiscale ensemble approach

    Science.gov (United States)

    Cheluvaraja, S.; Ortoleva, P.

    2010-02-01

    Deductive all-atom multiscale techniques imply that many nanosystems can be understood in terms of the slow dynamics of order parameters that coevolve with the quasiequilibrium probability density for rapidly fluctuating atomic configurations. The result of this multiscale analysis is a set of stochastic equations for the order parameters whose dynamics is driven by thermal-average forces. We present an efficient algorithm for sampling atomistic configurations in viruses and other supramillion atom nanosystems. This algorithm allows for sampling of a wide range of configurations without creating an excess of high-energy, improbable ones. It is implemented and used to calculate thermal-average forces. These forces are then used to search the free-energy landscape of a nanosystem for deep minima. The methodology is applied to thermal structures of Cowpea chlorotic mottle virus capsid. The method has wide applicability to other nanosystems whose properties are described by the CHARMM or other interatomic force field. Our implementation, denoted SIMNANOWORLD™, achieves calibration-free nanosystem modeling. Essential atomic-scale detail is preserved via a quasiequilibrium probability density while overall character is provided via predicted values of order parameters. Applications from virology to the computer-aided design of nanocapsules for delivery of therapeutic agents and of vaccines for nonenveloped viruses are envisioned.

  10. Infinitely robust order and local order-parameter tulips in Apollonian networks with quenched disorder

    Science.gov (United States)

    Kaplan, C. Nadir; Hinczewski, Michael; Berker, A. Nihat

    2009-06-01

    For a variety of quenched random spin systems on an Apollonian network, including ferromagnetic and antiferromagnetic bond percolation and the Ising spin glass, we find the persistence of ordered phases up to infinite temperature over the entire range of disorder. We develop a renormalization-group technique that yields highly detailed information, including the exact distributions of local magnetizations and local spin-glass order parameters, which turn out to exhibit, as function of temperature, complex and distinctive tulip patterns.

  11. Kernel methods for interpretable machine learning of order parameters

    Science.gov (United States)

    Ponte, Pedro; Melko, Roger G.

    2017-11-01

    Machine learning is capable of discriminating phases of matter, and finding associated phase transitions, directly from large data sets of raw state configurations. In the context of condensed matter physics, most progress in the field of supervised learning has come from employing neural networks as classifiers. Although very powerful, such algorithms suffer from a lack of interpretability, which is usually desired in scientific applications in order to associate learned features with physical phenomena. In this paper, we explore support vector machines (SVMs), which are a class of supervised kernel methods that provide interpretable decision functions. We find that SVMs can learn the mathematical form of physical discriminators, such as order parameters and Hamiltonian constraints, for a set of two-dimensional spin models: the ferromagnetic Ising model, a conserved-order-parameter Ising model, and the Ising gauge theory. The ability of SVMs to provide interpretable classification highlights their potential for automating feature detection in both synthetic and experimental data sets for condensed matter and other many-body systems.

  12. Observations of multiple order parameters in 5f electron systems

    International Nuclear Information System (INIS)

    Blackburn, E.

    2005-12-01

    In this thesis, multiple order parameters originating in the same electronic system are studied. The multi-k magnetic structures, where more than one propagation wavevector, k, is observed in the same volume, are considered as prototypical models. The effect of this structure on the elastic and inelastic response is studied. In cubic 3-k uranium rock-salts, unexpected elastic diffraction events were observed at positions in reciprocal space where the structure factor should have been zero. These diffraction peaks are identified with correlations between the (orthogonal) magnetic order parameters. The 3-k structure also affects the observed dynamics; the spin-wave fluctuations in uranium dioxide as observed by inelastic neutron polarization analysis can only be explained on the basis of a 3-k structure. In the antiferromagnetic superconductor UPd 2 Al 3 the magnetic order and the super-conducting state coexist, and are apparently generated by the same heavy fermions. The effect of an external magnetic field on both the normal and superconducting states is examined. In the normal state, the compound displays Fermi-liquid-like behaviour. The inelastic neutron response is strongly renormalized on entering the superconducting state, and high-precision measurements of the low-energy transfer part of this response confirm that the superconducting energy gap has the same symmetry as the antiferromagnetic lattice. (author)

  13. Selective suppression of high-order harmonics within phase-matched spectral regions.

    Science.gov (United States)

    Lerner, Gavriel; Diskin, Tzvi; Neufeld, Ofer; Kfir, Ofer; Cohen, Oren

    2017-04-01

    Phase matching in high-harmonic generation leads to enhancement of multiple harmonics. It is sometimes desired to control the spectral structure within the phase-matched spectral region. We propose a scheme for selective suppression of high-order harmonics within the phase-matched spectral region while weakly influencing the other harmonics. The method is based on addition of phase-mismatched segments within a phase-matched medium. We demonstrate the method numerically in two examples. First, we show that one phase-mismatched segment can significantly suppress harmonic orders 9, 15, and 21. Second, we show that two phase-mismatched segments can efficiently suppress circularly polarized harmonics with one helicity over the other when driven by a bi-circular field. The new method may be useful for various applications, including the generation of highly helical bright attosecond pulses.

  14. Suppression of zero order diffraction from the reconstructed images in digital holography

    Directory of Open Access Journals (Sweden)

    M R Rashidian Vaziri

    2016-02-01

    Full Text Available The numerically reconstructed images in digital holography contain two undesirable features. After reconstruction, the zero order diffraction as well as the complex conjugate image will be present in pictures and drastically reduce their qualities. Practical applications of digital holography in the context of characterization and measuring the physical properties of objects require the suppression of these two features, before starting the reconstruction phase. In this work, using the required mathematical functions for suppressing the zero order diffraction and by transforming them to their discrete form, numerical filters for passing over the CCD images have been constructed. After passing these filters over the experimentally recorded CCD images, the reconstruction phase has been completed applying the discrete Fresnel transform. Carefully investigating the quality of various reconstructed images, we came to the conclusion that if a filter covers a smaller neighborhood of the recorded CCD images, it will have a better performance in suppressing the zero order diffraction. Among the used filters in this work, a 3×3 average filter showed the best performance in suppressing the zero order diffraction from the reconstructed images.

  15. Unconventional superconductors experimental investgation of the order-parameter symmetry

    CERN Document Server

    Goll, Gernot

    2006-01-01

    This book offers a comprehensive summary of experiments that are especially suited to reveal the order-parameter symmetry of unconventional superconductors. It briefly introduces readers to the basic theoretical concepts and terms of unconventional superconductivity, followed by a detailed overview of experimental techniques and results investigating the superconducting energy gap and phase, plus the pairing symmetry. This review includes measurements of specific heat, thermal conductivity, penetration depth and nuclearmagnetic resonance and muon-spin rotation experiments. Further, point-contact and tunnelling spectroscopy and Josephson experiments are addressed. Current understanding is reviewed from the experimental point of view. With an appendix offering five tables with almost 200 references that summarize the present results from ambient pressure heavy-fermion and noncopper-oxide superconductors, the monograph provides a valuable resource for further studies in this field.

  16. Symmetry and order parameter dynamics of the human odometer.

    Science.gov (United States)

    Abdolvahab, Mohammad; Carello, Claudia; Pinto, Carla; Turvey, M T; Frank, Till D

    2015-02-01

    Bipedal gaits have been classified on the basis of the group symmetry of the minimal network of identical differential equations (alias cells) required to model them. Primary bipedal gaits (e.g., walk, run) are characterized by dihedral symmetry, whereas secondary bipedal gaits (e.g., gallop-walk, gallop- run) are characterized by a lower, cyclic symmetry. This fact has been used in tests of human odometry (e.g., Turvey et al. in P Roy Soc Lond B Biol 276:4309-4314, 2009, J Exp Psychol Hum Percept Perform 38:1014-1025, 2012). Results suggest that when distance is measured and reported by gaits from the same symmetry class, primary and secondary gaits are comparable. Switching symmetry classes at report compresses (primary to secondary) or inflates (secondary to primary) measured distance, with the compression and inflation equal in magnitude. The present research (a) extends these findings from overground locomotion to treadmill locomotion and (b) assesses a dynamics of sequentially coupled measure and report phases, with relative velocity as an order parameter, or equilibrium state, and difference in symmetry class as an imperfection parameter, or detuning, of those dynamics. The results suggest that the symmetries and dynamics of distance measurement by the human odometer are the same whether the odometer is in motion relative to a stationary ground or stationary relative to a moving ground.

  17. Order parameters for the high-energy spectra of pulsars

    Science.gov (United States)

    Torres, Diego F.

    2018-03-01

    Neutron stars are a common compact endpoint of the life of stars. Magnetized and rotating neutron stars emit beams of radiation, which can only be seen when the observer and the beam stand aligned. Periodic recurrence of such alignment gives rise to pulsations and to the name `pulsar' for the star itself. We present a physical model for the non-thermal emission of pulsars. With just four physical parameters, we fit the spectra of the γ- and X-ray pulsars across seven orders of magnitude in energy. We find that all detections can be encompassed in a continuous variation of the model parameters. The model explains the appearance of sub-exponential cutoffs at high energies as a natural consequence of synchro-curvature-dominated losses, unveiling that curvature-only emission plays a less significant role—if any—in the spectrum of most pulsars. The model also explains the flattening of the X-ray spectra at soft energies as a result of propagating particles being subject to synchrotron losses all along their trajectories. Using this model, we analyse how observations in γ-rays can predict the detectability of the pulsar in X-rays, and vice versa.

  18. Vibration Suppression for Improving the Estimation of Kinematic Parameters on Industrial Robots

    Directory of Open Access Journals (Sweden)

    David Alejandro Elvira-Ortiz

    2016-01-01

    Full Text Available Vibration is a phenomenon that is present on every industrial system such as CNC machines and industrial robots. Moreover, sensors used to estimate angular position of a joint in an industrial robot are severely affected by vibrations and lead to wrong estimations. This paper proposes a methodology for improving the estimation of kinematic parameters on industrial robots through a proper suppression of the vibration components present on signals acquired from two primary sensors: accelerometer and gyroscope. A Kalman filter is responsible for the filtering of spurious vibration. Additionally, a sensor fusion technique is used to merge information from both sensors and improve the results obtained using each sensor separately. The methodology is implemented in a proprietary hardware signal processor and tested in an ABB IRB 140 industrial robot, first by analyzing the motion profile of only one joint and then by estimating the path tracking of two welding tasks: one rectangular and another one circular. Results from this work prove that the sensor fusion technique accompanied by proper suppression of vibrations delivers better estimation than other proposed techniques.

  19. On the Interplay between Order Parameter Dynamics and System Parameter Dynamics in Human Perceptual-Cognitive-Behavioral Systems.

    Science.gov (United States)

    Frank, T D

    2015-04-01

    Previous research has demonstrated that perceiving, thinking, and acting are human activities that correspond to self-organized patterns. The emergence of such patterns can be completely described in terms of the dynamics of the pattern amplitudes, which are referred to as order parameters. The patterns emerge at bifurcations points when certain system parameters internal and external to a human agent exceed critical values. At issue is how one might study the order parameter dynamics for sequences of consecutive, emergent perceptual, cognitive, or behavioral activities. In particular, these activities may in turn impact the system parameters that have led to the emergence of the activities in the first place. This interplay between order parameter dynamics and system parameter dynamics is discussed in general and formulated in mathematical terms. Previous work that has made use of this two-tiered framework of order parameter and system parameter dynamics are briefly addressed. As an application, a model for perception under functional fixedness is presented. Finally, it is argued that the phenomena that emerge in this framework and can be observed when human agents perceive, think, and act are just as likely to occur in pattern formation systems of the inanimate world. Consequently, these phenomena do not necessarily have a neurophysiological basis but should instead be understood from the perspective of the theory of self-organization.

  20. Two-Order-Parameter Description of Liquids: Critical Phenomena and Phase Separation of Supercooled Liquids

    OpenAIRE

    Tanaka, Hajime

    1997-01-01

    Because of the isotropic and disordered nature of liquids, the anisotropy hidden in intermolecular interactions are often neglected. Accordingly, the order parameter describing a simple liquid has so far been believed to be only density. In contrast to this common sense, we propose that two order parameters, namely, density and bond order parameters, are required to describe the phase behavior of liquids since they intrinsically tend to form local bonds. This model gives us clear physical exp...

  1. Constituent Order in Minimalist Syntax, Universals and Parameters. (VP-Specifier and VP-Complement Order

    Directory of Open Access Journals (Sweden)

    Rachid Bouziane

    2017-01-01

    Full Text Available Natural Languages adopt a variety of structural strategies and architectures in ordering syntactic constituents. We will try in this paper to explain how these strategies and architectures are explained within the Minimalist Program framework. According to this framework, the most significant parametric differences between natural languages in constituent word order are widely and strongly limited to lexical differences. They are specifically attributed to the N-features and V-features of lexical items that occupy the functional category nodes, basically elements belonging to the functional categories Agreement and Tense: “The N-features are those that are checked off against a DP in [Spec, AGRP] (or, potentially, [Spec, TP]”, and “the V-features are those that are checked off against a V that adjoins to a functional head”.

  2. Standardizing therapeutic parameters of acupuncture for pain suppression in rats: preliminary study.

    Science.gov (United States)

    Yeo, Sujung; Lim, Hyungtaeck; Choe, Ilwhan; Kim, Sung-Hoon; Lim, Sabina

    2014-01-15

    Despite acupuncture's wide and successful use, it is still considered as lacking scientifically rigorous evidence, especially with respect to its effectiveness. To address this problem, it is necessary to re-examine the practice of acupuncture using scientific methodology. The standardization of acupuncture practices may offer a solution. As a preliminary step towards the standardization of acupuncture stimulation in animal experiments, this study attempted to clarify the various therapeutic parameters that contribute to acupuncture's efficacy. This study identified specific acupoints, temporal point of needling, rotation of the needle, duration of acupuncture, and diameter of the needle as the parameters, through formalin test. In this test, acupuncture was performed on either the ST36 or LR2 point immediately after pain induction and 5 minutes after pain induction. The formalin test yielded no significant suppression of pain in the case of ST36 and LR2 acupuncture stimulation immediately following pain induction. When acupuncture was applied 5 minutes after pain induction, however, the ST36 stimulation resulted in a significant decrease in pain, while the LR2 stimulation produced no change. The duration of acupuncture, but not the diameter of the needle, was also significant. As for the rotation of the needle, there was no significant difference in the pain reduction achieved in the rotation and non-rotation groups. We determined that specific acupoint, temporal point of needling, and duration of treatment are important factors in the inhibition of pain. These finding strongly suggest that in animal experiments, the application of a set of appropriate therapeutic parameters can significantly influence the outcome.

  3. Variances as order parameter and complexity measure for random Boolean networks

    International Nuclear Information System (INIS)

    Luque, Bartolo; Ballesteros, Fernando J; Fernandez, Manuel

    2005-01-01

    Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We compute its value analytically and compare it with the results of numerical experiments. Finally, we propose a complexity measure based on the compromise between temporal and spatial variances. This new order parameter and its related complexity measure can be easily applied to other complex systems

  4. Variances as order parameter and complexity measure for random Boolean networks

    Energy Technology Data Exchange (ETDEWEB)

    Luque, Bartolo [Departamento de Matematica Aplicada y EstadIstica, Escuela Superior de Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain); Ballesteros, Fernando J [Observatori Astronomic, Universitat de Valencia, Ed. Instituts d' Investigacio, Pol. La Coma s/n, E-46980 Paterna, Valencia (Spain); Fernandez, Manuel [Departamento de Matematica Aplicada y EstadIstica, Escuela Superior de Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain)

    2005-02-04

    Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We compute its value analytically and compare it with the results of numerical experiments. Finally, we propose a complexity measure based on the compromise between temporal and spatial variances. This new order parameter and its related complexity measure can be easily applied to other complex systems.

  5. Parameters and Fractional Differentiation Orders Estimation for Linear Continuous-Time Non-Commensurate Fractional Order Systems

    KAUST Repository

    Belkhatir, Zehor

    2017-05-31

    This paper proposes a two-stage estimation algorithm to solve the problem of joint estimation of the parameters and the fractional differentiation orders of a linear continuous-time fractional system with non-commensurate orders. The proposed algorithm combines the modulating functions and the first-order Newton methods. Sufficient conditions ensuring the convergence of the method are provided. An error analysis in the discrete case is performed. Moreover, the method is extended to the joint estimation of smooth unknown input and fractional differentiation orders. The performance of the proposed approach is illustrated with different numerical examples. Furthermore, a potential application of the algorithm is proposed which consists in the estimation of the differentiation orders of a fractional neurovascular model along with the neural activity considered as input for this model.

  6. An approach to design controllers for MIMO fractional-order plants based on parameter optimization algorithm.

    Science.gov (United States)

    Xue, Dingyü; Li, Tingxue

    2017-04-27

    The parameter optimization method for multivariable systems is extended to the controller design problems for multiple input multiple output (MIMO) square fractional-order plants. The algorithm can be applied to search for the optimal parameters of integer-order controllers for fractional-order plants with or without time delays. Two examples are given to present the controller design procedures for MIMO fractional-order systems. Simulation studies show that the integer-order controllers designed are robust to plant gain variations. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Suppression of high-order-harmonic intensities observed in aligned CO2 molecules with 1300-nm and 800-nm pulses

    International Nuclear Information System (INIS)

    Kato, Kosaku; Minemoto, Shinichirou; Sakai, Hirofumi

    2011-01-01

    High-order-harmonic generation from aligned N 2 , O 2 , and CO 2 molecules is investigated by 1300-nm and 800-nm pulses. The harmonic intensities of 1300-nm pulses from aligned molecules show harmonic photon energy dependence similar to those of 800-nm pulses. Suppression of harmonic intensity from aligned CO 2 molecules is observed for both 1300- and 800-nm pulses over the same harmonic photon energy range. As the dominant mechanism for the harmonic intensity suppression from aligned CO 2 molecules, the present results support the two-center interference picture rather than the dynamical interference picture.

  8. Quasiclassical description of multi-band superconductors with two order parameters

    Energy Technology Data Exchange (ETDEWEB)

    Moor, Andreas

    2014-05-19

    This Thesis deals with multi-band superconductors with two order parameters, i.e., the superconductivity and the spin-density wave, also touching on one-band superconductors with a charge-density wave, as well as with only the superconducting order parameter. Quasiclassical description of suchlike structures is developed and applied to investigation of various effects, inter alia, the Josephson and the proximity effects, the Knight shift, the Larkin-Ovchinnikov-Fulde-Ferrell-like state, and the interplay of the order parameters in coexistence regime. The applicability of the developed approach to pnictides is discussed.

  9. The effects of suppressing intrusive thoughts on dream content, dream distress and psychological parameters.

    Science.gov (United States)

    Kröner-Borowik, Tana; Gosch, Stefanie; Hansen, Kathrin; Borowik, Benjamin; Schredl, Michael; Steil, Regina

    2013-10-01

    Suppressing unwanted thoughts can lead to an increased occurrence of the suppressed thought in dreams. This is explainable by the ironic control theory, which theorizes why the suppression of thoughts might make them more persistent. The present study examined the influence of thought suppression on dream rebound, dream distress, general psychiatric symptomatology, depression, sleep quality and perceived stress. Thirty healthy participants (good sleepers) were investigated over a period of 1 week. Half were instructed to suppress an unwanted thought 5 min prior to sleep, whereas the other half were allowed to think of anything at all. Dream content was assessed through a dream diary. Independent raters assessed whether or not the dreams were related to the suppressed target thought. The results demonstrated increased target-related dreams and a tendency to have more distressing dreams in the suppression condition. Moreover, the data imply that thought suppression may lead to significantly increased general psychiatric symptomatology. No significant effects were found for the other secondary outcomes. © 2013 European Sleep Research Society.

  10. Random textures of the order parameter of superfluid sup 3 He-B in aerogel

    CERN Document Server

    Fomin, Yu A

    2002-01-01

    The scheme for describing the properties of the superfluid sup 3 He in the aerogel is proposed in accordance with the Ginzburg and Landau theory. The aerogel effect on the order parameter is described by the random tensor field. This field exerts desorientation effect on the order parameter in the sup 3 He A-phase, but it does not influence the order parameter orientation in the B-phase, if there is no magnetic field. The change in the order parameter texture, originating in the B-phase in the aerogel in the magnetic field, is considered. Fluctuations of the sup 3 He-B anisotropy axis direction are correlated on the length, inversely proportional to the field intensity and having the macroscopic scale

  11. Order parameter fluctuations at a critical point - an exact result about percolation -

    International Nuclear Information System (INIS)

    Botet, Robert

    2011-01-01

    The order parameter of the system in the critical state, is expected to undergo large non-Gaussian fluctuations. However, almost nothing is known about the mathematical forms of the possible probability distributions of the order parameter. A remarkable exception is the site-percolation on the Bethe lattice, for which the complete order-parameter distribution has been recently derived at the critical point. Surprisingly, it appears to be the Kolmogorov-Smirnov distribution, well known in very different areas of mathematical statistics. In the present paper, we explain first how this special distribution could appear naturally in the context of the critical systems, under the assumption (still virtually unstudied) of the exponential distribution of the number of domains of a given size. In a second part, we present for the first time the complete derivation of the order-parameter distribution for the critical percolation model on the Bethe lattice, thus completing a recent publication announcing this result.

  12. Magnetic phase transitions with incommensurate structures in systems with coupled order parameters

    International Nuclear Information System (INIS)

    Izyumov, Yu.A.; Laptev, V.M.; Petrov, S.B.

    1984-01-01

    Modulated magnetic phases are investigated for the case when symmetry does not allow linear by gradients Lifshits invariants and magnetic momenta are converted by two irreducible representations. Possible phase diagrams with participation of incommensurable phases are plotted on the base of Ginsburg-Landau functional for 2 bound parameters of the order. The role of the highest harmonics in spatial distribution of the order parameters is clarified on the example of magnetic phase transitions in Er

  13. A Simple Method for Estimation of Parameters in First order Systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Miklos, Robert

    2014-01-01

    A simple method for estimation of parameters in first order systems with time delays is presented in this paper. The parameter estimation approach is based on a step response for the open loop system. It is shown that the estimation method does not require a complete step response, only a part of...

  14. Suppression of Arterial Thrombosis without Affecting Hemostatic Parameters with A Cell-Penetrating PAR1 Pepducin

    Science.gov (United States)

    Zhang, Ping; Gruber, András; Kasuda, Shogo; Kimmelstiel, Carey; O’Callaghan, Katie; Cox, Daniel H.; Bohm, Andrew; Baleja, James D.; Covic, Lidija; Kuliopulos, Athan

    2012-01-01

    Background Thrombin-dependent platelet activation is heightened in the setting of percutaneous coronary intervention (PCI) and may cause arterial thrombosis with consequent myocardial necrosis. Given the high incidence of adverse effects in patients with acute coronary syndromes (ACS), there remains an unmet need for the development of new therapeutics that target platelet activation without unduly affecting hemostasis. The thrombin receptor, PAR1, has recently emerged as a promising new target for therapeutic intervention in ACS patients. Methods and Results We report the development of a first-in-class intracellular PAR1 inhibitor with optimized pharmacokinetic properties for use during PCI in ACS patients. PZ-128 is a cell-penetrating ‘pepducin’ inhibitor of PAR1 which targets the receptor-G protein interface on the inside surface of platelets. The structure of PZ-128 closely resembles the predicted off-state of the corresponding juxtamembrane region of the third intracellular loop of PAR1. The onset of action of PZ-128 was rapid and suppressed PAR1 aggregation and arterial thrombosis in guinea pigs and baboons and strongly synergized with oral clopidogrel. There was full recovery of platelet function by 24 h. Importantly, PZ-128 had no effect on bleeding or coagulation parameters in primates or in blood from PCI patients. Conclusions Based on the efficacy data in non-human primates with no noted adverse effects on hemostasis, we anticipate that the rapid onset of platelet inhibition and reversible properties of PZ-128 are well suited to the acute interventional setting of PCI and may provide an alternative to long-acting small molecule inhibitors of PAR1. PMID:22705889

  15. Self-assembled fluids with order-parameter-dependent mobility: The ...

    Indian Academy of Sciences (India)

    The study is for quenching from an uncorrelated high temperature state into the Lifshitz line within the microemulsion phase. In the later stage of the ordering process, the structure factor exhibits multiscaling behavior with characteristic length scale (/ ln )1/2(2+3). The order-parameter-dependent mobility is found to slow ...

  16. Effect of X-ray suppression system upon parameters of electrostatic accelerator ion beam

    Directory of Open Access Journals (Sweden)

    I. G. Ignat'ev

    2014-12-01

    Full Text Available Experimental study results are presented for a beam profile and emittance of an electrostatic accelerator “Sokol” before and after being equipped with magnet X-ray suppression system.

  17. Universal features of the order-parameter fluctuations: reversible and irreversible aggregation

    International Nuclear Information System (INIS)

    Botet, Robert; Ploszajczak, Marek

    2000-01-01

    We discuss the universal scaling laws of order parameter fluctuations in any system in which the second-order critical behaviour can be identified. These scaling laws can be derived rigorously for equilibrium systems when combined with the finite-size scaling analysis. The relation between order parameter, criticality and scaling law of fluctuations has been established and the connection between the scaling function and the critical exponents has been found. We give examples in out-of-equilibrium aggregation models such as the Smoluchowski kinetic equations, or of at-equilibrium Ising and percolation models. (authors)

  18. Observation of the transition between real and complex superconducting order parameter phases in UPt3

    Science.gov (United States)

    Strand, J. D.; Bahr, D. J.; van Harlingen, D. J.; Davis, J. P.; Gannon, W. J.; Halperin, W. P.

    2010-03-01

    The heavy fermion superconductor UPt3 provides a rich system for studying the competition between superconductivity and other forms of electronic order because it has an unconventional pairing mechanism, coexistence of anti-ferromagnetism and superconductivity, and two distinct superconducting phases characterized by different order parameter symmetries. We have fabricated Josephson tunnel junctions on the as-grown surfaces of UPt3 single crystals at a series of angles in the basal plane. By measuring their critical current, we map out the magnitude of the superconducting order parameter as a function of k-space direction and temperature. We observe a sharp node in the superconducting gap at 45^o with respect to the a-axis in the high temperature phase and the onset of an out-of-phase component creating a complex order parameter in the low temperature phase.

  19. HQET at order 1/m. Pt. 1. Non-perturbative parameters in the quenched approximation

    International Nuclear Information System (INIS)

    Blossier, Benoit; Della Morte, Michele; Garron, Nicolas; Edinburgh Univ.; Sommer, Rainer

    2010-01-01

    We determine non-perturbatively the parameters of the lattice HQET Lagrangian and those of heavy-light axial-vector and vector currents in the quenched approximation. The HQET expansion includes terms of order 1/m b . Our results allow to compute, for example, the heavy-light spectrum and B-meson decay constants in the static approximation and to order 1/m b in HQET. The determination of the parameters is separated into universal and non-universal parts. The universal results can be used to determine the parameters for various discretizations. The computation reported in this paper uses the plaquette gauge action and the ''HYP1/2'' action for the b-quark described by HQET. The parameters of the currents also depend on the light-quark action, for which we choose non-perturbatively O(a)-improved Wilson fermions. (orig.)

  20. NMR determination of the order parameter in proton and deuteron glasses

    International Nuclear Information System (INIS)

    Blinc, R.; Dolinsek, J.; Zalar, B.

    1989-01-01

    The inhomogeneous broadening of the ND + deuteron, O-D--O deuteron and 87 Rb quadrapole perturbed NMR spectra in Rb 0.56 (ND 4 ) 0.44 D 2 PO 4 is used for a direct determination of the Edwards-Anderson pseudo-spin glass order parameter. The data provide strong support for a model where the basic difference between magnetic spin glasses and proton or deuteron glasses is the presence of an inherent random field resulting from substitutional disorder which linearly couples to the O-D--O pseudo spins. In these systems we do not deal with a transition from a paraelectric to a pseudo-spin glass phase but rather with a transition from an ergodic pseudo-spin glass phase with a single order parameter q to a non-ergodic pseudo-spin glass phase with an infinite number of order parameters. (author). 11 refs.; 6 figs

  1. Ginsburg-Landau theory of two antagonistic order parameters: magnetism and superconductivity

    International Nuclear Information System (INIS)

    Suhl, H.

    1978-01-01

    An attempt is made to construct a Ginsburg-Landau theory of so-called magnetic superconductors. Two order parameters, the magnetization field and the gap function, are introduced in such a way as to inhibit each others growth. It is found that the non-local character of the superconducting order parameter must be taken into account in any evaluation of effects of the critical magnetic fluctuations. Some predictions are made within the limits of Ornstein-Zoernicke-like fluctuation theory and some comparison is made with available data. (Auth.)

  2. Chaos Suppression of an Electrically Actuated Microresonator Based on Fractional-Order Nonsingular Fast Terminal Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Jianxin Han

    2017-01-01

    Full Text Available This paper focuses on chaos suppression strategy of a microresonator actuated by two symmetrical electrodes. Dynamic behavior of this system under the case where the origin is the only stable equilibrium is investigated first. Numerical simulations reveal that system may exhibit chaotic motion under certain excitation conditions. Then, bifurcation diagrams versus amplitude or frequency of AC excitation are drawn to grasp system dynamics nearby its natural frequency. Results show that the vibration is complex and may exhibit period-doubling bifurcation, chaotic motion, or dynamic pull-in instability. For the suppression of chaos, a novel control algorithm, based on an integer-order nonsingular fast terminal sliding mode and a fractional-order switching law, is proposed. Fractional Lyapunov Stability Theorem is used to guarantee the asymptotic stability of the system. Finally, numerical results with both fractional-order and integer-order control laws show that our proposed control law is effective in controlling chaos with system uncertainties and external disturbances.

  3. Suppression of Magnetic Order before the Superconducting Dome in MnP

    Science.gov (United States)

    Yano, Shin-ichiro; Lançon, Diane; Rønnow, Henrik M.; Hansen, Thomas C.; Ressouche, Eric; Qureshi, Navid; Ouladdiaf, Bachir; Gardner, Jason S.

    2018-02-01

    We have performed neutron diffraction experiments on the manganese superconductor, MnP, under applied pressure. Higher harmonics of the previously reported double helix (2δ and 3δ) at ambient pressure were observed and a new magnetic phases was discovered as hydrostatic pressure was applied to a polycrystalline sample below the pressure required to induce superconductivity. The double helix magnetic structure is suppressed by 0.7 GPa. A new incommensurate magnetic structure with propagation vector ˜ (0.25,0.25,0.125) was found at 1.5 GPa. The application of higher pressures results in the quenching of the incommensurate phase and broad, diffuse magnetic scattering develops before the superconducting phase. Single crystal studies complement the polycrystalline data confirming the magnetic propagation vector in the low pressure phase.

  4. Parameter estimation of fractional-order chaotic systems by using quantum parallel particle swarm optimization algorithm.

    Directory of Open Access Journals (Sweden)

    Yu Huang

    Full Text Available Parameter estimation for fractional-order chaotic systems is an important issue in fractional-order chaotic control and synchronization and could be essentially formulated as a multidimensional optimization problem. A novel algorithm called quantum parallel particle swarm optimization (QPPSO is proposed to solve the parameter estimation for fractional-order chaotic systems. The parallel characteristic of quantum computing is used in QPPSO. This characteristic increases the calculation of each generation exponentially. The behavior of particles in quantum space is restrained by the quantum evolution equation, which consists of the current rotation angle, individual optimal quantum rotation angle, and global optimal quantum rotation angle. Numerical simulation based on several typical fractional-order systems and comparisons with some typical existing algorithms show the effectiveness and efficiency of the proposed algorithm.

  5. Spatial variations of order parameter around Kondo impurity for T<=Tsub(c)

    International Nuclear Information System (INIS)

    Yoksan, S.

    1980-04-01

    Analytic expressions for the spatial variations of the order parameter around a Kondo impurity are obtained. The oscillatory contribution due to the impurity scattering is calculated using the t matrix of Matsuura which conveniently yields the general results below Tsub(c). Differences between our values and those of Schlottmann are reported. (author)

  6. Suppression of the Coffee-Ring Effect and Evaporation-Driven Disorder to Order Transition in Colloidal Droplets.

    Science.gov (United States)

    Das, Shyamashis; Dey, Atreya; Reddy, Govardhan; Sarma, D D

    2017-10-05

    The formation of a ring-like deposit at the periphery of a drying colloidal droplet is a vexing problem in many applications. We show a complete suppression of such deposits when a droplet of aqueous colloidal suspension, deposited on a glass substrate coated with a thin layer of silicone oil, is evaporated. This coating prevents the periphery of the aqueous droplet from getting pinned to the substrate and helps in suppressing the ring formation. It also decreases the surface area of the droplet, thereby decreasing the evaporation rate. These two factors together, driving the colloidal particles slowly to the center of the droplet, contribute to form an ordered crystallite at the end of the evaporation process. Brownian dynamics simulations performed to study ordering in the aggregate show that the spherical colloidal particles form face-centered cubic structures. Experiments and simulations show that slow rates of droplet evaporation and smaller-sized colloidal particles further lead to high-quality ordered colloidal crystallites.

  7. Evaluation of third order nonlinear optical parameters of CdS/PVA nanocomposite

    International Nuclear Information System (INIS)

    Sharma, Mamta; Tripathi, S. K.

    2015-01-01

    CdS nanoparticles dispersed in PVA are prepared by Chemical method at room temperature. The nonlinear optical parameters such as nonlinear absorption (β), nonlinear refractive index (n 2 ) and nonlinear susceptibility (χ 3 ) are calculated for this sample by using Z-scan technique. CdS/PVA samples show the two photon absorption mechanism. The third order nonlinear susceptibility is calculated from n 2 and β and is found to be of the order of 10 −7 – 10 −8 m 2 /V 2 . The larger value of third order nonlinear susceptibility is due to dielectric and quantum confinement effect

  8. Unexpected behavior of an order parameter for lattice gauge theories with matter fields

    International Nuclear Information System (INIS)

    Meyer, H.

    1983-07-01

    I consider a slightly modified definition of an order parameter that was recently suggested by DeTar and McLerran. It is supposed to test for confinement in lattice gauge theories when arbitrary matter fields are present, at finite physical temperature β -1 > 0. Its definition is quite directly related to confinement in the sense that no physical states with fractional baryon number can be observed. We test the parameter for different ranges of the coupling constants in the Z(2) Higgs model, whose phase structure is well known at zero temperature. It is found that the order parameter always shows the behavior characteristic of confinement, for all values of the coupling constants and arbitrary nonzero temperature. (orig.)

  9. New ways enhancing the vital activity of plants in order to increase crop yields and to suppress radionuclide accumulation

    International Nuclear Information System (INIS)

    Goncharova, N. V; Zebrakova, I. V.; Matsko, V. P.; Kislushko, P. M.

    1994-01-01

    After Chernobyl nuclear accident it has become very important to seek new ways of enhancing the vital activity of plants in order to increase crop yields and to suppress radionuclide accumulation. It is found that by optimizing the vital activity processes in plants, is possible to reduce radionuclide uptake. A great number of biologically active compounds have been tested, which increased the disease resistance of plants and simultaneously activated the physiological and biochemical processes that control the transport of micro- and macroelements (radionuclide included) and their 'soil-root-stem-leaf' redistribution. (author)

  10. BWR MARK I pressure suppression pool mixing and stratification analysis using GOTHIC lumped parameter modeling methodology

    International Nuclear Information System (INIS)

    Ozdemir, Ozkan Emre; George, Thomas L.

    2015-01-01

    As a part of the GOTHIC (GOTHIC incorporates technology developed for the electric power industry under the sponsorship of EPRI.) Fukushima Technical Evaluation project (EPRI, 2014a, b, 2015), GOTHIC (EPRI, 2014c) has been benchmarked against test data for pool stratification (EPRI, 2014a, b, Ozdemir and George, 2013). These tests confirmed GOTHIC’s ability to simulate pool mixing and stratification under a variety of anticipated suppression pool operating conditions. The multidimensional modeling requires long simulation times for events that may occur over a period of hours or days. For these scenarios a lumped model of the pressure suppression chamber is desirable to maintain reasonable simulation times. However, a lumped model for the pool is not able to predict the effects of pool stratification that can influence the overall containment response. The main objective of this work is on the development of a correlation that can be used to estimate pool mixing and stratification effects in a lumped modeling approach. A simplified lumped GOTHIC model that includes a two zone model for the suppression pool with controlled circulation between the upper and lower zones was constructed. A pump and associated flow connections are included to provide mixing between the upper and lower pool volumes. Using numerically generated data from a multidimensional GOTHIC model for the suppression pool, a correlation was developed for the mixing rate between the upper and lower pool volumes in a two-zone, lumped model. The mixing rate depends on the pool subcooling, the steam injection rate and the injection depth

  11. Order parameters in the Landau–de Gennes theory – the static and dynamic scenarios

    KAUST Repository

    Majumdar, Apala

    2011-02-17

    We obtain quantitative estimates for the scalar order parameters of liquid crystal configurations in three-dimensional geometries, within the Landau-de Gennes framework. We consider both static equilibria and non-equilibrium dynamics and we include external fields and surface anchoring energies in our formulation. Using maximum principle-type arguments, we obtain explicit bounds for the corresponding scalar order parameters in both static and dynamic situations; these bounds are given in terms of the material-dependent thermotropic coefficients, electric field strength and surface anchoring coefficients. These bounds provide estimates for the degree of orientational ordering, quantify the competing effects of the different energetic contributions and can be used to test the accuracy of numerical simulations. © 2011 Taylor & Francis.

  12. 5f delocalization-induced suppression of quadrupolar order in U(Pd1-xPtx)(3)

    OpenAIRE

    Walker, H. C.; Le, M. D.; McEwen, K. A.; Bleckmann, M.; Suellow, S.; Mazzoli, C.; Wilkins, S. B.; Fort, D.

    2011-01-01

    We present bulk magnetic and transport measurements and x-ray resonant scattering measurements on U(Pd1−xPtx)3 for x=0.005 and 0.01, which demonstrate the high sensitivity of the quadrupolar order in the canonical antiferroquadrupolar ordered system UPd3 to doping with platinum. Bulk measurements for x=0.005 reveal behavior similar to that seen in UPd3, albeit at a lower temperature, and x-ray resonant scattering provides evidence of quadrupolar order described by the Qxy order parameter. In ...

  13. Slow order-parameter fluctuations in superconducting Pb and Ag/Nb films observed using β-detected nuclear magnetic resonance

    Science.gov (United States)

    Morenzoni, E.; Saadaoui, H.; Wang, D.; Horisberger, M.; Kirk, E. C.; MacFarlane, W. A.; Morris, G. D.; Chow, K. H.; Hossain, M. D.; Levy, C. P.; Parolin, T. J.; Pearson, M. R.; Song, Q.; Kiefl, R. F.

    2012-06-01

    We report β-NMR investigations of polarized 8Li implanted in thin Pb and Ag/Nb films. At the critical superconducting temperature, we observe a singular peak in the spin relaxation rate in small longitudinal magnetic fields, which is attributed to unexpected slow fluctuations in the superconducting order parameter. The peak is several orders of magnitude larger than the prediction based on the enhancement of the dynamic electron spin susceptibility by superconducting fluctuations. The observed peak in (1)/(T1) is rapidly suppressed in a small magnetic field, indicating that it is due to remarkably slow diamagnetic fluctuations which are undetectable with conventional NMR.

  14. Measurement of fractional order model parameters of respiratory mechanical impedance in total liquid ventilation.

    Science.gov (United States)

    Beaulieu, Alexandre; Bossé, Dominick; Micheau, Philippe; Avoine, Olivier; Praud, Jean-Paul; Walti, Hervé

    2012-02-01

    This study presents a methodology for applying the forced-oscillation technique in total liquid ventilation. It mainly consists of applying sinusoidal volumetric excitation to the respiratory system, and determining the transfer function between the delivered flow rate and resulting airway pressure. The investigated frequency range was f ∈ [0.05, 4] Hz at a constant flow amplitude of 7.5 mL/s. The five parameters of a fractional order lung model, the existing "5-parameter constant-phase model," were identified based on measured impedance spectra. The identification method was validated in silico on computer-generated datasets and the overall process was validated in vitro on a simplified single-compartment mechanical lung model. In vivo data on ten newborn lambs suggested the appropriateness of a fractional-order compliance term to the mechanical impedance to describe the low-frequency behavior of the lung, but did not demonstrate the relevance of a fractional-order inertance term. Typical respiratory system frequency response is presented together with statistical data of the measured in vivo impedance model parameters. This information will be useful for both the design of a robust pressure controller for total liquid ventilators and the monitoring of the patient's respiratory parameters during total liquid ventilation treatment. © 2011 IEEE

  15. Second Order Harmonics Suppression With Glass Filters for Synchrotron UV Radiation Calibration Measurement

    CERN Document Server

    Burattini, E; Gambicorti, L; Malvezzi, F; Marcelli, A; Monti, F; Pace, E

    2005-01-01

    This development is the latest result of the cooperation between the National Laboratories of Frascati and the Department of Astronomy and Space Science of the University of Florence to improve the capabilities of the existing DXR-2 beam line at the DAΦNE-LIGHT laboratories. This collaboration has assessed a new facility in order to characterize optics and sensors in a wide spectral range (ranging from VUV to IR). Previous measurements [1] have highlighted some limitations in the present setup, as higher signal levels due to the diffracted radiation of the grating in the second order have to be removed to allow an accurate detection. In this work a glass filter is used to remove such spurious signal present in the spectral region with λ > 360 nm. The characteristics of the filter and its application to the optical system used to measure the sensitivity of a diamond-based photoconductor have been discussed.

  16. Thermal conductivity of unconventional superconductors: a probe of the order parameter symmetry

    International Nuclear Information System (INIS)

    Ausloos, M.; Houssa, M.

    1999-01-01

    Experimental data and theoretical aspects of the thermal conductivity κ and magneto-thermal conductivity κ(B) of high-T c superconductors and heavy fermions are reviewed in the very-low-temperature region in order to sort out features and convincing arguments for deciding on the order parameter symmetry. In the case of high-T c cuprates, the analysis of experimental results in YBa 2 Cu 3 O 7-δ and Bi 2 Sr 2 CaCu 2 O 8 samples is not consistent with an isotropic s-wave energy gap parameter but can be well described by considering an anisotropic d x 2 -y 2 -wave energy gap parameter, i.e. with nodes in the gap. Furthermore, the field dependence of the thermal conductivity of e.g. YBa 2 Cu 3 O 7-δ and Bi 2 Sr 2 CaCu 2 O 8 can be explained by assuming that electrons are mainly scattered by the vortex cores like those of a d-wave superconductor. In the case of the heavy fermion superconductor UPt 3 , the κ anisotropy found for the field-free and field dependence of the thermal conductivity allows us to discriminate the symmetry of the energy gap parameter. The latter is consistent with a gap parameter of E 2u type, i.e. with lines of nodes along the basal plane and quadratic point nodes along the c-axis. (author)

  17. Modulating functions method for parameters estimation in the fifth order KdV equation

    KAUST Repository

    Asiri, Sharefa M.

    2017-07-25

    In this work, the modulating functions method is proposed for estimating coefficients in higher-order nonlinear partial differential equation which is the fifth order Kortewegde Vries (KdV) equation. The proposed method transforms the problem into a system of linear algebraic equations of the unknowns. The statistical properties of the modulating functions solution are described in this paper. In addition, guidelines for choosing the number of modulating functions, which is an important design parameter, are provided. The effectiveness and robustness of the proposed method are shown through numerical simulations in both noise-free and noisy cases.

  18. Coexistence of two vector order parameters: a holographic model for ferromagnetic superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Andrea [Dipartimento di Fisica, Università di Genova, and I.N.F.N. - Sezione di Genova, via Dodecaneso 33, 16146, Genova (Italy); Braggio, Alessandro [CNR-SPIN, via Dodecaneso 33, 16146, Genova (Italy); Maggiore, Nicola; Magnoli, Nicodemo [Dipartimento di Fisica, Università di Genova, and I.N.F.N. - Sezione di Genova, via Dodecaneso 33, 16146, Genova (Italy); Musso, Daniele [Physique Théorique et Mathématique, Université Libre de Bruxelles, C.P. 231, 1050 Bruxelles (Belgium)

    2014-01-13

    We study a generalization of the standard holographic p-wave superconductor featuring two interacting vector order parameters. Basing our argument on the symmetry and linear response properties of the model, we propose it as a holographic effective theory describing a strongly coupled ferromagnetic superconductor. We show that the two order parameters undergo concomitant condensations as a manifestation of an intrinsically interlaced charge/spin dynamics. Such intertwined dynamics is confirmed by the study of the transport properties. We characterize thoroughly the equilibrium and the linear response (i.e. optical conductivity and spin susceptibility) of the model at hand by means of a probe approximation analysis. Some insight about the effects of backreaction in the normal phase can be gained by analogy with the s-wave unbalanced holographic superconductor.

  19. Order Parameter as an Additional State Variable of Unstable Traffic Flow

    OpenAIRE

    Lubashevsky, Ihor A.; Mahnke, Reinhard

    1999-01-01

    We discuss a phenomenological approach to the description of unstable vehicle motion on multilane highways that could explain in a simple way such observed self-organizing phenomena as the sequence of the phase transitions "free flow -> synchronized motion -> jam" and the hysteresis in them. We introduce a new variable called order parameter that accounts for possible correlations in the vehicle motion at different lanes. So, it is principally due to "many-body" effects in the car interaction...

  20. Higher Order Elastic Constants, Gruneisen Parameters and Lattice Thermal Expansion of Lithium Niobate

    Directory of Open Access Journals (Sweden)

    Thresiamma Philip

    2006-01-01

    Full Text Available The second and third-order elastic constants and pressure derivatives of second- order elastic constants of trigonal LiNbO3 (lithium niobate have been obtained using the deformation theory. The strain energy density estimated using finite strain elasticity is compared with the strain dependent lattice energy density obtained from the elastic continuum model approximation. The second-order elastic constants and the non-vanishing third-order elastic constants along with the pressure derivatives of trigonal LiNbO3 are obtained in the present work. The second and third-order elastic constants are compared with available experimental values. The second-order elastic constant C11 which corresponds to the elastic stiffness along the basal plane of the crystal is less than C33 which corresponds to the elastic stiffness tensor component along the c-axis of the crystal. The pressure derivatives, dC'ij/dp obtained in the present work, indicate that trigonal LiNbO3 is compressible. The higher order elastic constants are used to find the generalized Gruneisen parameters of the elastic waves propagating in different directions in LiNbO3. The Brugger gammas are evaluated and the low temperature limit of the Gruneisen gamma is obtained. The results are compared with available reported values.

  1. On the relationship between NMR-derived amide order parameters and protein backbone entropy changes.

    Science.gov (United States)

    Sharp, Kim A; O'Brien, Evan; Kasinath, Vignesh; Wand, A Joshua

    2015-05-01

    Molecular dynamics simulations are used to analyze the relationship between NMR-derived squared generalized order parameters of amide NH groups and backbone entropy. Amide order parameters (O(2) NH ) are largely determined by the secondary structure and average values appear unrelated to the overall flexibility of the protein. However, analysis of the more flexible subset (O(2) NH  entropy than that reported by the side chain methyl axis order parameters, O(2) axis . A calibration curve for backbone entropy vs. O(2) NH is developed, which accounts for both correlations between amide group motions of different residues, and correlations between backbone and side chain motions. This calibration curve can be used with experimental values of O(2) NH changes obtained by NMR relaxation measurements to extract backbone entropy changes, for example, upon ligand binding. In conjunction with our previous calibration for side chain entropy derived from measured O(2) axis values this provides a prescription for determination of the total protein conformational entropy changes from NMR relaxation measurements. © 2015 Wiley Periodicals, Inc.

  2. Coarse-graining for fast dynamics of order parameters in the phase-field model

    Science.gov (United States)

    Jou, D.; Galenko, P. K.

    2018-01-01

    In standard descriptions, the master equation can be obtained by coarse-graining with the application of the hypothesis of full local thermalization that is equivalent to the local thermodynamic equilibrium. By contrast, fast transformations proceed in the absence of local equilibrium and the master equation must be obtained with the absence of thermalization. In the present work, a non-Markovian master equation leading, in specific cases of relaxation to local thermodynamic equilibrium, to hyperbolic evolution equations for a binary alloy, is derived for a system with two order parameters. One of them is a conserved order parameter related to the atomistic composition, and the other one is a non-conserved order parameter, which is related to phase field. A microscopic basis for phenomenological phase-field models of fast phase transitions, when the transition is so fast that there is not sufficient time to achieve local thermalization between two successive elementary processes in the system, is provided. In a particular case, when the relaxation to local thermalization proceeds by the exponential law, the obtained coarse-grained equations are related to the hyperbolic phase-field model. The solution of the model equations is obtained to demonstrate non-equilibrium phenomenon of solute trapping which appears in rapid growth of dendritic crystals. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  3. Correlations and local order parameter in the paraelectric phase of barium titanate.

    Science.gov (United States)

    Geneste, Grégory

    2011-03-30

    General features of the order parameter distribution in barium titanate in its paraelectric phase and in its ferroelectric phases (tetragonal and orthorhombic) are presented. The density of probability of the polarization [Formula: see text], defined by an average of the local order parameters over regions of various sizes and shapes (L(x) × L(y) × L(z)), is examined by molecular dynamics simulations using a first-principles derived effective Hamiltonian. The free energies [Formula: see text] associated with these probabilities are computed by thermodynamic integration. The evolution of these quantities are explained through the computation of pair correlations, which are found, as stated in several previous works, very anisotropic, 'needle-like', with longitudinal correlations ([Formula: see text]) having much longer range than transverse ones ([Formula: see text]). The correlations explain why the density of probability of the order parameter evolves from a multiple-peaked distribution with maxima along [111] (in the single cell), along [100] for small needle-like regions, towards a single-peaked distribution for larger regions. A useful expression in which the shape-dependence of the free energy is manifest is provided.

  4. Four-order stiffness variation of laser-fabricated photopolymer biodegradable scaffolds by laser parameter modulation

    International Nuclear Information System (INIS)

    Farkas, Balázs; Romano, Ilaria; Ceseracciu, Luca; Diaspro, Alberto; Brandi, Fernando; Beke, Szabolcs

    2015-01-01

    The effects of various fabrication parameters of our Mask Projection Excimer Laser StereoLithography (MPExSL) system were investigated. We demonstrate that laser parameters directly change the physical properties (stiffness, thermal degradation, and height/thickness) of the poly(propylene fumarate) (PFF) scaffold structures. The tested parameters were the number of pulses, fluence per pulse and laser repetition rate. We present a four-order tuning capability of MPExSL-fabricated structures' stiffness without altering the resin composition or using cumbersome post-treatment procedures. Thermogravimetric analysis and differential scanning calorimetry confirmed this tuning capability. Prototype-segmented scaffold designs are presented and analyzed to further expand the concept and exploit this in situ stiffness tuning capability of the scaffolds for tissue engineering and regenerative medicine applications. - Highlights: • Facile stiffness control of scaffolds is beneficial in tissue engineering. • Four-order tuning capability of structures' stiffness is presented. • Scaffold's stiffness can be tuned in four orders (4 MPa–4 GPa). • All scaffolds have been fabricated from the same polymer resin in a broad stiffness range

  5. Evaluation of third order nonlinear optical parameters of CdS/PVA nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mamta [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160014 (India); Department of Applied Sciences (Physics), UIET, Panjab University, Chandigarh-160014 (India); Tripathi, S. K., E-mail: surya@pu.ac.in, E-mail: surya-tr@yahoo.com [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160014 (India)

    2015-06-24

    CdS nanoparticles dispersed in PVA are prepared by Chemical method at room temperature. The nonlinear optical parameters such as nonlinear absorption (β), nonlinear refractive index (n{sub 2}) and nonlinear susceptibility (χ{sup 3}) are calculated for this sample by using Z-scan technique. CdS/PVA samples show the two photon absorption mechanism. The third order nonlinear susceptibility is calculated from n{sub 2} and β and is found to be of the order of 10{sup −7} – 10{sup −8} m{sup 2}/V{sup 2}. The larger value of third order nonlinear susceptibility is due to dielectric and quantum confinement effect.

  6. TOPICAL REVIEW: Thermal conductivity of unconventional superconductors: a probe of the order parameter symmetry

    Science.gov (United States)

    Ausloos, M.; Houssa, M.

    1999-07-01

    Experimental data and theoretical aspects of the thermal conductivity icons/Journals/Common/kappa" ALT="kappa" ALIGN="TOP"/> and magneto-thermal conductivity icons/Journals/Common/kappa" ALT="kappa" ALIGN="TOP"/>(B) of high-Tc superconductors and heavy fermions are reviewed in the very-low-temperature region in order to sort out features and convincing arguments for deciding on the order parameter symmetry. In the case of high-Tc cuprates, the analysis of experimental results in YBa2Cu3O7-icons/Journals/Common/delta" ALT="delta" ALIGN="MIDDLE"/> and Bi2Sr2CaCu2O8 samples is not consistent with an isotropic s-wave energy gap parameter but can be well described by considering an anisotropic dx2-y2-wave energy gap parameter, i.e. with nodes in the gap. Furthermore, the field dependence of the thermal conductivity of e.g. YBa2Cu3O7-icons/Journals/Common/delta" ALT="delta" ALIGN="MIDDLE"/> and Bi2Sr2CaCu2O8 can be explained by assuming that electrons are mainly scattered by the vortex cores like those of a d-wave superconductor. In the case of the heavy fermion superconductor UPt3, the icons/Journals/Common/kappa" ALT="kappa" ALIGN="TOP"/> anisotropy found for the field-free and field dependence of the thermal conductivity allows us to discriminate the symmetry of the energy gap parameter. The latter is consistent with a gap parameter of E2u type, i.e. with lines of nodes along the basal plane and quadratic point nodes along the c-axis.

  7. Theoretical and experimental study of ions focusing systems in order to improve the ions beam brightness by suppressing aberration causes

    International Nuclear Information System (INIS)

    Faure, J.

    1966-01-01

    It is shown that a beam brightness can be improved by an order of magnitude when the sources of aberrations are suppressed in the anode region source, as well as in the extraction region and in the electrostatic focusing system. A calculation was first set up to determine a simple focusing system. The aberration ratio due to this focusing system is smaller than 10 to 15 per cent. The experimental study was developed by using an ion source and its extraction system capable of producing an aberration free beam at an energy of 20 keV and an accelerating unit up to 190 keV that confirms that the qualities of a 35 mA beam produced by the said ion source are not spoiled when the beam goes through the focusing and accelerating system that was designed to be aberration free. (author) [fr

  8. Higher order mode suppression in high-Q anomalous dispersion SiN microresonators for temporal dissipative Kerr soliton formation.

    Science.gov (United States)

    Kordts, A; Pfeiffer, M H P; Guo, H; Brasch, V; Kippenberg, T J

    2016-02-01

    High-Q silicon nitride (SiN) microresonators enable optical Kerr frequency comb generation on a photonic chip and have recently been shown to support fully coherent combs based on temporal dissipative Kerr soliton formation. For bright soliton formation, it is necessary to operate SiN waveguides in the multimode regime in order to produce waveguide induced anomalous group velocity dispersion. However, this regime can lead to local disturbances of the dispersion due to avoided crossings caused by coupling between different mode families and, therefore, prevent the soliton formation. Here, we demonstrate that a single-mode "filtering" section inside high-Q resonators enables efficiently suppression of avoided crossings, while preserving high quality factors (Q∼10(6)). We verify the approach by demonstrating single soliton formation in SiN resonators with a filtering section.

  9. The modular S-matrix as order parameter for topological phase transitions

    International Nuclear Information System (INIS)

    Bais, F A; Romers, J C

    2012-01-01

    We study topological phase transitions in discrete gauge theories in two spatial dimensions induced by the formation of a Bose condensate. We analyse a general class of euclidean lattice actions for these theories which contain one coupling constant for each conjugacy class of the gauge group. To probe the phase structure we use a complete set of open and closed anyonic string operators. The open strings allow one to determine the particle content of the condensate, whereas the closed strings enable us to determine the matrix elements of the modular S-matrix, in both the unbroken and broken phases. From the measured broken S-matrix we may read off the sectors that split or get identified in the broken phase, as well as the sectors that are confined. In this sense the modular S-matrix can be employed as a matrix valued nonlocal order parameter from which the low-energy effective theories that occur in different regions of parameter space can be fully determined. To verify our predictions, we studied a non-abelian anyon model based on the quaternion group H=D-bar 2 of the order of eight by Monte Carlo simulation. We probe part of the phase diagram for the pure gauge theory and find a variety of phases with magnetic condensates leading to various forms of (partial) confinement in complete agreement with the algebraic breaking analysis. Also the order of various transitions is established. (paper)

  10. Behaviour of the order parameter of the simple magnet in an external field

    Directory of Open Access Journals (Sweden)

    M.P.Kozlovskii

    2005-01-01

    Full Text Available The effect of a homogeneous external field on the three-dimensional uniaxial magnet behaviour near the critical point is investigated within the framework of the nonperturbative collective variables method using the ρ4 model. The research is carried out for the low-temperature region. The analytic explicit expressions for the free energy, average spin moment and susceptibility are obtained for weak and strong fields in comparison with the field value belonging to the pseudocritical line. The calculations are performed on the microscopic level without any adjusting parameters. It is established that the long-wave fluctuations of the order parameter play a crucial role in forming a crossover between the temperature-dependence and field-dependence critical behaviour of the system.

  11. Assessing Local Structure Motifs Using Order Parameters for Motif Recognition, Interstitial Identification, and Diffusion Path Characterization

    Directory of Open Access Journals (Sweden)

    Nils E. R. Zimmermann

    2017-11-01

    Full Text Available Structure–property relationships form the basis of many design rules in materials science, including synthesizability and long-term stability of catalysts, control of electrical and optoelectronic behavior in semiconductors, as well as the capacity of and transport properties in cathode materials for rechargeable batteries. The immediate atomic environments (i.e., the first coordination shells of a few atomic sites are often a key factor in achieving a desired property. Some of the most frequently encountered coordination patterns are tetrahedra, octahedra, body and face-centered cubic as well as hexagonal close packed-like environments. Here, we showcase the usefulness of local order parameters to identify these basic structural motifs in inorganic solid materials by developing classification criteria. We introduce a systematic testing framework, the Einstein crystal test rig, that probes the response of order parameters to distortions in perfect motifs to validate our approach. Subsequently, we highlight three important application cases. First, we map basic crystal structure information of a large materials database in an intuitive manner by screening the Materials Project (MP database (61,422 compounds for element-specific motif distributions. Second, we use the structure-motif recognition capabilities to automatically find interstitials in metals, semiconductor, and insulator materials. Our Interstitialcy Finding Tool (InFiT facilitates high-throughput screenings of defect properties. Third, the order parameters are reliable and compact quantitative structure descriptors for characterizing diffusion hops of intercalants as our example of magnesium in MnO2-spinel indicates. Finally, the tools developed in our work are readily and freely available as software implementations in the pymatgen library, and we expect them to be further applied to machine-learning approaches for emerging applications in materials science.

  12. Order parameter fluctuations in natural time and b-value variation before large earthquakes

    Directory of Open Access Journals (Sweden)

    E. S. Skordas

    2012-11-01

    Full Text Available Self-similarity may stem from two origins: the process increments infinite variance and/or process memory. The b-value of the Gutenberg-Richter law comes from the first origin. In the frame of natural time analysis of earthquake data, a fall of the b-value observed before large earthquakes reflects an increase of the order parameter fluctuations upon approaching the critical point (mainshock. The increase of these fluctuations, however, is also influenced from the second origin of self-similarity, i.e., temporal correlations between earthquake magnitudes. This is supported by observations and simulations of an earthquake model.

  13. Nonlinear Parameter-Varying AeroServoElastic Reduced Order Model for Aerostructural Sensing and Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the project is to develop reliable reduced order modeling technologies to automatically generate nonlinear, parameter-varying (PV),...

  14. Minimum of the order parameter fluctuations of seismicity before major earthquakes in Japan.

    Science.gov (United States)

    Sarlis, Nicholas V; Skordas, Efthimios S; Varotsos, Panayiotis A; Nagao, Toshiyasu; Kamogawa, Masashi; Tanaka, Haruo; Uyeda, Seiya

    2013-08-20

    It has been shown that some dynamic features hidden in the time series of complex systems can be uncovered if we analyze them in a time domain called natural time χ. The order parameter of seismicity introduced in this time domain is the variance of χ weighted for normalized energy of each earthquake. Here, we analyze the Japan seismic catalog in natural time from January 1, 1984 to March 11, 2011, the day of the M9 Tohoku earthquake, by considering a sliding natural time window of fixed length comprised of the number of events that would occur in a few months. We find that the fluctuations of the order parameter of seismicity exhibit distinct minima a few months before all of the shallow earthquakes of magnitude 7.6 or larger that occurred during this 27-y period in the Japanese area. Among the minima, the minimum before the M9 Tohoku earthquake was the deepest. It appears that there are two kinds of minima, namely precursory and nonprecursory, to large earthquakes.

  15. Simulation of Higher-Order Electrical Circuits with Stochastic Parameters via SDEs

    Directory of Open Access Journals (Sweden)

    BRANCIK, L.

    2013-02-01

    Full Text Available The paper deals with a technique for the simulation of higher-order electrical circuits with parameters varying randomly. The principle consists in the utilization of the theory of stochastic differential equations (SDE, namely the vector form of the ordinary SDEs. Random changes of both excitation voltage and some parameters of passive circuit elements are considered, and circuit responses are analyzed. The voltage and/or current responses are computed and represented in the form of the sample means accompanied by their confidence intervals to provide reliable estimates. The method is applied to analyze responses of the circuit models of optional orders, specially those consisting of a cascade connection of the RLGC networks. To develop the model equations the state-variable method is used, afterwards a corresponding vector SDE is formulated and a stochastic Euler numerical method applied. To verify the results the deterministic responses are also computed by the help of the PSpice simulator or the numerical inverse Laplace transforms (NILT procedure in MATLAB, while removing random terms from the circuit model.

  16. Thickness dependent structural order in P3HT films - a key parameter for high OFET mobility

    Energy Technology Data Exchange (ETDEWEB)

    Gburek, Benedikt; Sharma, Richa; Balster, Torsten; Wagner, Veit [School of Engineering and Science, Jacobs University Bremen (Germany)

    2010-07-01

    Applications of organic electronics require cheap and fast production methods on flexible substrates. Following these goals, top-gate OFETs on PET foils were used to analyze the dependence of the device characteristics on the crucial parameter of semiconductor layer thickness. The organic semiconductor, regio-regular P3HT, and the gate insulator were deposited by spin-coating under atmospheric conditions. The charge carrier mobility was found to be rather low for extremely thin layers of several nanometers only. However, with increasing layer thickness, mobility increases by two orders of magnitude until a ''saturation thickness'' of 50 nm, above which it remains constant. Further details of the ordering were extracted according to the Vissenberg-Matters model with gate-voltage dependent mobility {mu}={mu}{sub 0}((V{sub GS}-V{sub th})/1V){sup {gamma}}, where {gamma} is directly related to the width of the density of states. The analysis reveals that the disorder parameter {gamma} decreases from 3.1 to 1.0 over the examined thickness range, which explains the low mobility of thinner films by higher energetic disorder. This analysis proves to be highly advantageous as it represents the whole transfer curve, gives better comparability and offers more physical insight. Our study demonstrates the crucial role of layer thickness tuning for improved film structure and optimum material performance.

  17. Deterministic flows of order-parameters in stochastic processes of quantum Monte Carlo method

    International Nuclear Information System (INIS)

    Inoue, Jun-ichi

    2010-01-01

    In terms of the stochastic process of quantum-mechanical version of Markov chain Monte Carlo method (the MCMC), we analytically derive macroscopically deterministic flow equations of order parameters such as spontaneous magnetization in infinite-range (d(= ∞)-dimensional) quantum spin systems. By means of the Trotter decomposition, we consider the transition probability of Glauber-type dynamics of microscopic states for the corresponding (d + 1)-dimensional classical system. Under the static approximation, differential equations with respect to macroscopic order parameters are explicitly obtained from the master equation that describes the microscopic-law. In the steady state, we show that the equations are identical to the saddle point equations for the equilibrium state of the same system. The equation for the dynamical Ising model is recovered in the classical limit. We also check the validity of the static approximation by making use of computer simulations for finite size systems and discuss several possible extensions of our approach to disordered spin systems for statistical-mechanical informatics. Especially, we shall use our procedure to evaluate the decoding process of Bayesian image restoration. With the assistance of the concept of dynamical replica theory (the DRT), we derive the zero-temperature flow equation of image restoration measure showing some 'non-monotonic' behaviour in its time evolution.

  18. Higher-Order Approximations of Motion of a Nonlinear Oscillator Using the Parameter Expansion Technique

    Science.gov (United States)

    Ganji, S. S.; Domairry, G.; Davodi, A. G.; Babazadeh, H.; Seyedalizadeh Ganji, S. H.

    The main objective of this paper is to apply the parameter expansion technique (a modified Lindstedt-Poincaré method) to calculate the first, second, and third-order approximations of motion of a nonlinear oscillator arising in rigid rod rocking back. The dynamics and frequency of motion of this nonlinear mechanical system are analyzed. A meticulous attention is carried out to the study of the introduced nonlinearity effects on the amplitudes of the oscillatory states and on the bifurcation structures. We examine the synchronization and the frequency of systems using both the strong and special method. Numerical simulations and computer's answers confirm and complement the results obtained by the analytical approach. The approach proposes a choice to overcome the difficulty of computing the periodic behavior of the oscillation problems in engineering. The solutions of this method are compared with the exact ones in order to validate the approach, and assess the accuracy of the solutions. In particular, APL-PM works well for the whole range of oscillation amplitudes and excellent agreement of the approximate frequency with the exact one has been demonstrated. The approximate period derived here is accurate and close to the exact solution. This method has a distinguished feature which makes it simple to use, and also it agrees with the exact solutions for various parameters.

  19. Partial compensation interferometry for measurement of surface parameter error of high-order aspheric surfaces

    Science.gov (United States)

    Hao, Qun; Li, Tengfei; Hu, Yao

    2018-01-01

    Surface parameters are the properties to describe the shape characters of aspheric surface, which mainly include vertex radius of curvature (VROC) and conic constant (CC). The VROC affects the basic properties, such as focal length of an aspheric surface, while the CC is the basis of classification for aspheric surface. The deviations of the two parameters are defined as surface parameter error (SPE). Precisely measuring SPE is critical for manufacturing and aligning aspheric surface. Generally, SPE of aspheric surface is measured directly by curvature fitting on the absolute profile measurement data from contact or non-contact testing. And most interferometry-based methods adopt null compensators or null computer-generated holograms to measure SPE. To our knowledge, there is no effective way to measure SPE of highorder aspheric surface with non-null interferometry. In this paper, based on the theory of slope asphericity and the best compensation distance (BCD) established in our previous work, we propose a SPE measurement method for high-order aspheric surface in partial compensation interferometry (PCI) system. In the procedure, firstly, we establish the system of two element equations by utilizing the SPE-caused BCD change and surface shape change. Then, we can simultaneously obtain the VROC error and CC error in PCI system by solving the equations. Simulations are made to verify the method, and the results show a high relative accuracy.

  20. Experimental Study of Three-body Cabibbo-suppressed D0 Decays and Extraction of Cp Violation Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Kalanand; /Nehru U.

    2008-02-22

    The authors present measurements of the relative branching ratios, Dalitz plot structures and CP-asymmetry values in the three-body singly Cabibbo-suppressed decays D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0} {yields} K{sup -}K{sup +}{pi}{sup 0} using data collected by the BABAR detector at the PEP-II asymmetric-energy ring at SLAC. The author applies the results of the D{sup 0} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup 0} analysis to extracting CP-violation parameters related to the CKM angle {gamma} (or {phi}{sub 3}) using the decay B{sup -} {yields} D{sub {pi}{sup +}{pi}{sup -}{pi}{sup 0}} K{sup -}.

  1. Multi-source localization in MEG using simulated annealing: model order determination and parameter accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, M.; Supek, S.; Aine, C.

    1996-06-01

    Empirical neuromagnetic studies have reported that multiple brain regions are active at single instants in time as well as across time intervals of interest. Determining the number of active regions, however, required a systematic search across increasing model orders using reduced chi-square measure of goodness-of-fit and multiple starting points within each model order assumed. Simulated annealing was recently proposed for noiseless biomagnetic data as an effective global minimizer. A modified cost function was also proposed to effectively deal with an unknown number of dipoles for noiseless, multi-source biomagnetic data. Numerical simulation studies were conducted using simulated annealing to examine effects of a systematic increase in model order using both reduced chi-square as a cost function as well as a modified cost function, and effects of overmodeling on parameter estimation accuracy. Effects of different choices of weighting factors are also discussed. Simulated annealing was also applied to visually evoked neuromagnetic data and the effectiveness of both cost functions in determining the number of active regions was demonstrated.

  2. Nonlinear Interaction of Zero Sound with the Order Parameter Collective Modes in Superfluid HELIUM-3-BORON.

    Science.gov (United States)

    McKenzie, Ross Hugh

    A brief overview of past experimental and theoretical investigations of the linear and nonlinear interaction of zero sound with the order parameter collective modes in superfluid ^3He-B is given before introducing the quasiclassical (QC) theory of superfluid ^3He. A new approach to calculating the linear and nonlinear response is presented. The QC propagator is calculated by expanding the low energy Dyson's equation in powers of the nonequilibrium self energy. The expression given for the expansion coefficients, involving products of pairs of equilibrium Green's functions, has a simple diagrammatic representation, and establishes a connection between the QC theory and other theoretical formalisms which have been used to investigate the collective modes. It is shown that the expansion coefficients satisfy Onsager-like relations and some identities required by gauge and galilean invariance. Consequently, this new approach to deriving dynamical equations for the collective modes is more efficient and transparent than solving the QC transport equations. This new approach is used to investigate the linear coupling of zero sound to the order parameter collective modes in weakly inhomogeneous superfluid ^3 He. It makes tractable the treatment of (nonlinear) parametric processes involving zero sound and the collective modes. It is shown that the approximate particle-hole symmetry of the ^3He Fermi liquid determines important selection rules for nonlinear acoustic processes, just as it is well known to do for linear processes. Analogues with nonlinear optics guide the derivation, solution and interpretation of the dynamical equations for a three-wave resonance between two zero sound waves and the J = 2 ^+ order parameter collective mode. It is shown that stimulated Raman scattering and two phonon absorption of zero sound by the J = 2^+ collective mode should be observable when the pump sound wave has energy density larger than about one percent of the superfluid

  3. Local tuning of the order parameter in superconducting weak links: A zero-inductance nanodevice

    Science.gov (United States)

    Winik, Roni; Holzman, Itamar; Dalla Torre, Emanuele G.; Buks, Eyal; Ivry, Yachin

    2018-03-01

    Controlling both the amplitude and the phase of the superconducting quantum order parameter (" separators="|ψ ) in nanostructures is important for next-generation information and communication technologies. The lack of electric resistance in superconductors, which may be advantageous for some technologies, hinders convenient voltage-bias tuning and hence limits the tunability of ψ at the microscopic scale. Here, we demonstrate the local tunability of the phase and amplitude of ψ, obtained by patterning with a single lithography step a Nb nano-superconducting quantum interference device (nano-SQUID) that is biased at its nanobridges. We accompany our experimental results by a semi-classical linearized model that is valid for generic nano-SQUIDs with multiple ports and helps simplify the modelling of non-linear couplings among the Josephson junctions. Our design helped us reveal unusual electric characteristics with effective zero inductance, which is promising for nanoscale magnetic sensing and quantum technologies.

  4. Quasiparticles and order parameter near quantum phase transition in heavy fermion metals

    Energy Technology Data Exchange (ETDEWEB)

    Shaginyan, V.R. [Petersburg Nuclear Physics Institute, Russian Academy of Sciences, Gatchina 188300 (Russian Federation) and CTSPS, Clark Atlanta University, Atlanta, GA 30314 (United States)]. E-mail: vrshag@thd.pnpi.spb.ru; Msezane, A.Z. [CTSPS, Clark Atlanta University, Atlanta, GA 30314 (United States); Amusia, M.Ya. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); A.F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

    2005-05-02

    It is shown that the Landau paradigm based upon both the quasiparticle concept and the notion of the order parameter is valid and can be used to explain the anomalous behavior of the heavy fermion metals near quantum critical points. The understanding of this phenomenon has been problematic largely because of the absence of theoretical guidance. Exploiting this paradigm and the fermion condensation quantum phase transition, we investigate the anomalous behavior of the heavy electron liquid near its critical point at different temperatures and applied magnetic fields. We show that this anomalous behavior is universal and can be used to capture the essential aspects of recent experiments on heavy-fermion metals at low temperatures.

  5. Hannay angle. Yet another symmetry-protected topological order parameter in classical mechanics

    International Nuclear Information System (INIS)

    Kariyado, Toshikaze; Hatsugai, Yasuhiro

    2016-01-01

    The topological way of thinking now goes beyond quantum solids, and topological characters of classical mechanical systems obeying Newton's law are attracting current interest. To provide a physical insight into the topological numbers in mechanics, we demonstrate the use of the Hannay angle, a “classical” Berry phase, as a symmetry-protected topological order parameter. The Hannay angle is derived using a canonical transformation that maps Newton's equation to a Schrödinger-type equation, and the condition for the quantization is discussed in connection with the symmetry in mechanics. Also, we demonstrate the use of the Hannay angle for a topological characterization of a spring-mass model focusing on the bulk-edge correspondence. (author)

  6. Suppression and nonlinear excitation of parasitic modes in second harmonic gyrotrons operating in a very high order mode

    International Nuclear Information System (INIS)

    Nusinovich, Gregory S.; Pu, Ruifeng; Granatstein, Victor L.

    2015-01-01

    In recent years, there was an active development of high-power, sub-terahertz (sub-THz) gyrotrons for numerous applications. For example, a 0.67 THz gyrotron delivering more than 200 kW with about 20% efficiency was developed. This record high efficiency was achieved because the gyrotron operated in a high-order TE 31,8 -mode with the power of ohmic losses less than 10% of the power of outgoing radiation. That gyrotron operated at the fundamental cyclotron resonance, and a high magnetic field of about 27 T was created by a pulse solenoid. For numerous applications, it is beneficial to use gyrotrons at cyclotron harmonics which can operate in available cryomagnets with fields not exceeding 15 T. However, typically, the gyrotron operation at harmonics faces severe competition from parasitic modes at the fundamental resonance. In the present paper, we consider a similar 0.67 THz gyrotron designed for operation in the same TE 31,8 -mode, but at the second harmonic. We focus on two nonlinear effects typical for interaction between the fundamental and second harmonic modes, viz., the mode suppression and the nonlinear excitation of the mode at the fundamental harmonic by the second harmonic oscillations. Our study includes both the analytical theory and numerical simulations performed with the self-consistent code MAGY. The simulations show that stable second harmonic operation in the TE 31,8 mode is possible with only modest sacrifice of efficiency and power

  7. Parameter Sensitivity of High–Order Equivalent Circuit Models Of Turbine Generator

    Directory of Open Access Journals (Sweden)

    T. Niewierowicz–Swiecicka

    2010-01-01

    Full Text Available This work shows the results of a parametric sensitivity analysis applied to a state–space representation of high–order two–axis equivalent circuits (ECs of a turbo generator (150 MVA, 120 MW, 13.8 kV y 50 Hz. The main purpose of this study is to evaluate each parameter impact on the transient response of the analyzed two–axis models –d–axis ECs with one to five damper branches and q–axis ECs from one to four damper branches–. The parametric sensitivity concept is formulated in a general context and the sensibility function is established from the generator response to a short circuit condition. Results ponder the importance played by each parameter in the model behavior. The algorithms were design within MATLAB® environment. The study gives way to conclusions on electromagnetic aspects of solid rotor synchronous generators that have not been previously studied. The methodology presented here can be applied to any other physical system.

  8. METABOLIC AND BEHAVIORAL PARAMETERS IN NEWBORN PIGLETS IN RELATION TO BIRTH ORDER

    Directory of Open Access Journals (Sweden)

    H. SĂRĂNDAN

    2008-05-01

    Full Text Available The experiment had 2 phases:During the first phase 19 sows were monitored during farrowing; the piglets were numbered according to birth order, they were weighed and there were recorded the time each piglet was born and when it first suckled. There was calculated the time from the beginning of the farrowing until the time each piglet was born (TNPP and the time from birth until the first suckle (TPS. A statistical correlation was established between these parameters.During the second experimental phase, for 49 piglets from 5 sows were determined: birth weight, TPS, glycemia at birth (G0 and after the first suckle (G1, rectal temperature at birth (T0 and after the first suckles (T1. This data was statistically analyzed using the Mann-Whitney U test.Respecting the birth order, TPS is shorter for piglets born last (p<0.05. Average TPS was 23.04±2.49 minutes; during this time glycemia rises from 58.35 mg% to 64.35 mg% and rectal temperature drops from 38.58°C to 37.35°C. T0 is positively correlated with G0 (p<0.01 with G1 (p<0.01 and T1 (p<0.01. G0 is highly correlated to G1 (r=0.8855; p=0.

  9. Dimensional study of the caging order parameter at the glass transition.

    Science.gov (United States)

    Charbonneau, Patrick; Ikeda, Atsushi; Parisi, Giorgio; Zamponi, Francesco

    2012-08-28

    The glass problem is notoriously hard and controversial. Even at the mean-field level, little is agreed upon regarding why a fluid becomes sluggish while exhibiting but unremarkable structural changes. It is clear, however, that the process involves self-caging, which provides an order parameter for the transition. It is also broadly assumed that this cage should have a gaussian shape in the mean-field limit. Here we show that this ansatz does not hold. By performing simulations as a function of spatial dimension d, we find the cage to keep a nontrivial form. Quantitative mean-field descriptions of the glass transition, such as mode-coupling theory, density functional theory, and replica theory, all miss this crucial element. Although the mean-field random first-order transition scenario of the glass transition is qualitatively supported here and non-mean-field corrections are found to remain small on decreasing d, reconsideration of its implementation is needed for it to result in a coherent description of experimental observations.

  10. Impurity bound states in d-wave superconductors with subdominant order parameters

    Science.gov (United States)

    Mashkoori, Mahdi; Björnson, Kristofer; Black-Schaffer, Annica

    Single magnetic impurity induces intra-gap bound states in conventional s-wave superconductors (SCs) but, in d-wave SCs only virtual bound states can be induced. However, in small cuprate islands a fully gapped spectrum has recently been discovered. In this work, we investigate the real bound states due to potential and magnetic impurities in the two candidate fully gapped states for this system: the topologically trivial d + is -wave state and the topologically non-trivial d + id' -wave (chiral d-wave state). Using the analytic T-matrix formalism and self-consistent numerical tight-binding lattice calculations, we show that potential and magnetic impurities create entirely different intra-gap bound states in d + is -wave and chiral d-wave SCs. Therefore, our results suggest that the bound states mainly depend on the subdominant order parameter. Considering that recent experiments have demonstrated an access to adjustable coupling J, impurities thus offer an intriguing way to clearly distinguish between the chiral d-wave and topologically trivial d + is -wave state. This work was supported by Swedish Research Council, Swedish Foundation for Strategic Research, the Wallenberg Academy Fellows program and the Göran Gustafsson Foundation. The computations were performed on resources provided by SNIC at LUNARC.

  11. Symmetry of order-parameters in high-Tc layered superconductors

    International Nuclear Information System (INIS)

    Rajagopal, A.K.; Jha, Sudhanshu S.

    1997-01-01

    It is well known that the anisotropy and wave-vector dependence of the energy-gap function determine many important properties of a superconductor which are relevant for device applications. Apart from a weak dependence on the wave-vector k - > in the direction perpendicular to the reciprocal layer-plane of a high-T c layered superconductor, it is shown that anisotropic superconducting order parameters for intra-layer pairing in the class of such materials with orthorhombic crystal structures, can have either pure s-wave like symmetry or mixed d-wave and anisotropic extended s-wave like symmetries in the reciprocal layer-plane. However, in such materials with tetragonal crystal structures, it is possible to have a pure s-wave like symmetry, which may be either isotropic or anisotropic in the layer k - >-space, or a pure d-wave like symmetry, as far the k - >-dependence in the reciprocal layer plane is concerned. In view of this, some suggestions for analysing experimental data will also be presented. (author)

  12. Nonlinear Parameter-Varying AeroServoElastic Reduced Order Model for Aerostructural Sensing and Control, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the project is to develop reliable reduced order modeling technologies to automatically generate parameter-varying (PV), aeroservoelastic (ASE)...

  13. The order parameter of high temperature superconductors, as measured by Andreev Saint-James reflection, Raman and neutron scattering

    OpenAIRE

    Hüfner, Stefan; Müller, Frank

    2010-01-01

    By comparing experiments that use Andreev Saint-James reflection, Raman scattering (B2g) and neutron scattering on the (cuprate) high temperature superconductors, evidence is found, that all of the techniques can measure the order parameter of these superconductors. The order parameter is the energy needed to take a superconducting boson out of the condensate. It has the same temperature and doping dependence as the superconducting transition temperature Tc. This condensation energy is differ...

  14. Optimization of accelerator parameters using normal form methods on high-order transfer maps

    Energy Technology Data Exchange (ETDEWEB)

    Snopok, Pavel [Michigan State Univ., East Lansing, MI (United States)

    2007-05-01

    in a way that is easy to understand, such important characteristics as the strengths of the resonances and the tune shifts with amplitude and various parameters of the system are calculated. Each major section is supplied with the results of applying various numerical optimization methods to the problems stated. The emphasis is made on the efficiency comparison of various approaches and methods. The main simulation tool is the arbitrary order code COSY INFINITY written by M. Berz, K. Makino, et al. at Michigan State University. Also, the code MAD is utilized to design the 750 x 750 GeV Muon Collider storage ring baseline lattice.

  15. Generalizing the order and the parameters of macro-operators by explanation-based learning - Extension of Explanation-Based Learning on Partial Order

    International Nuclear Information System (INIS)

    Li, Huihua

    1992-01-01

    The traditional generalization methods such as FIKE's macro-operator learning and Explanation-Based Learning (EBL) deal with totally ordered plans. They generalize only the plan operators and the conditions under which the generalized plan can be applied in its initial total order, but not the partial order among operators in which the generalized plan can be successfully executed. In this paper, we extend the notion of the EBL on the partial order of plans. A new method is presented for learning, from a totally or partially ordered plan, partially ordered macro-operators (generalized plans) each of which requires a set of the weakest conditions for its reuse. It is also valuable for generalizing partially ordered plans. The operators are generalized in the FIKE's triangle table. We introduce the domain axioms to generate the constraints for the consistency of generalized states. After completing the triangle table with the information concerning the operator destructions (interactions), we obtain the global explanation of the partial order on the operators. Then, we represent all the necessary ordering relations by a directed graph. The exploitation of this graph permits to explicate the dependence between the partial orders and the constraints among the parameters of generalized operators, and allows all the solutions to be obtained. (author) [fr

  16. Order parameter of a three-dimensional Ising-like system in the simplest and higher non-Gaussian approximations

    Directory of Open Access Journals (Sweden)

    I.V. Pylyuk

    2013-06-01

    Full Text Available The application of the collective variables method to the study of the behaviour of nonuniversal characteristics of the system in the critical region is illustrated by an example of the order parameter. Explicit expressions for the order parameter (the average spin moment of a three-dimensional uniaxial magnet are obtained in approximations of quartic and sextic non-Gaussian fluctuation distributions (the ρ4 and ρ6 models, respectively, taking into account confluent corrections. Some distinctive features appearing in the process of calculating the order parameter on the basis of two successive non-Gaussian approximations are indicated. The dependence of the average spin moment of an Ising-like system on the temperature and microscopic parameters is studied.

  17. Mechanisms of cross-suppression of TNP-specific plaque forming cell responses by TMA-specific first-order T suppressor factor

    Energy Technology Data Exchange (ETDEWEB)

    Jendrisak, G.S.; Bellone, C.J.

    1986-03-05

    The addition of hybridoma-derived phenyltrimethylammonium (TMA)-specific first-order T suppressor factor (TsF/sub 1/) into cultures containing Brucella abortus coupled with the TMA and trinitrophenol haptens (TMA-BA-TNP) results in the cross-suppression of TNP-specific plaque forming cell (PFC) responses. The suppression mediated by TMA-TsF/sub 1/ is dependent on the presence of T cells and specific antigen (TMA). Subculturing of whole spleen cells with TMA-TsF/sub 1/ and specific soluble antigen (TMA-BSA) is able to induce suppressor T cells which cross-suppress the TNP-specific PFC of spleen cell cultures stimulated with TMA-BA-TNP in an antigen (TMA)-dependent manner at the effector phase of the response. The effector acting T suppressor cells (Tse) are nylon wool nonadherent and appears to require whole spleen cells in responding cultures for suppression, suggesting that the target of the Tse is not the TNP-specific B cell. The authors are presently characterizing the mechanisms of cross-suppression by TMA-TsF/sub 1/ and Tse utilizing the described primary in vitro antibody assay.

  18. Observation of a common symmetry for the pseudogap and the superconducting order parameter near the surface of underdoped YBa2Cu3O6+x

    International Nuclear Information System (INIS)

    Koren, G.; Shkedy, L.; Polturak, E.

    2004-01-01

    Measurements of the angular dependence of conductance spectra in the a-b plane of underdoped YBa 2 Cu 3 O 6+x junctions are reported. At zero magnetic field the superconducting gap shows a vertical bar d+is vertical bar-like symmetry. Application of a magnetic field strongly suppresses this gap leaving only the pseudogap feature which also shows a vertical bar d+is vertical bar-like angular dependence. We thus observe the same symmetry for the superconducting gap and the pseudogap characterizing the YBCO electrodes near the interface with the barrier. An H c2 value of ∼5 T of the secondary (is) order parameter can also be deduced from our results

  19. Model-order reduction of lumped parameter systems via fractional calculus

    Science.gov (United States)

    Hollkamp, John P.; Sen, Mihir; Semperlotti, Fabio

    2018-04-01

    This study investigates the use of fractional order differential models to simulate the dynamic response of non-homogeneous discrete systems and to achieve efficient and accurate model order reduction. The traditional integer order approach to the simulation of non-homogeneous systems dictates the use of numerical solutions and often imposes stringent compromises between accuracy and computational performance. Fractional calculus provides an alternative approach where complex dynamical systems can be modeled with compact fractional equations that not only can still guarantee analytical solutions, but can also enable high levels of order reduction without compromising on accuracy. Different approaches are explored in order to transform the integer order model into a reduced order fractional model able to match the dynamic response of the initial system. Analytical and numerical results show that, under certain conditions, an exact match is possible and the resulting fractional differential models have both a complex and frequency-dependent order of the differential operator. The implications of this type of approach for both model order reduction and model synthesis are discussed.

  20. On the number of free energy extremums of a solid solution with two long-range order parameters

    International Nuclear Information System (INIS)

    Dateshidze, N.A.; Ratishvili, I.G.

    1977-01-01

    The free energy of ordering f.c.c. lattice solid solution is investigated. The ordering is regarded as homogeneous in the whole bulk of the crystal (i.e. resistant towards formation of antiphase domains). It is described by one of the appropriate distribution functions which contains two long-range order parameters. The calculations have revealed the extrema of the free energy function, and their shape and behaviour upon variations of temperature are analyzed. It is shown that under certain circumstances the system can display more than one minimum of free energy within the ordered phase

  1. Interpretation of Seemingly Contradictory Data: Low NMR S2Order Parameters Observed in Helices and High NMR S2Order Parameters in Disordered Loops of the Protein hGH at Low pH.

    Science.gov (United States)

    Smith, Lorna J; Athill, Roya; van Gunsteren, Wilfred F; Hansen, Niels

    2017-07-18

    At low pH, human growth hormone (hGH) adopts a partially folded state, in which the native helices are maintained, but the long loop regions and side-chain packing become disordered. Some of the S 2 order parameters for backbone N-H vectors derived from NMR relaxation measurements on hGH at low pH initially seem contradictory. Three isolated residues (15, 20, and 171) in helices A and D exhibit low order parameter values (<0.5) indicating flexibility, whereas residue 143 in the centre of a long flexible loop region has a high order parameter (0.82). Using S 2 order parameter restraining MD simulations, this paradox has been resolved. Low S 2 values in helices are due to the presence of a mixture of 3 10 -helical and α-helical hydrogen bonds. High S 2 values in relatively disordered parts of a protein may be due to fluctuating networks of hydrogen bonds between the backbone and the side chains, which restrict the motion of N-H bond vectors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Self-assembled fluids with order-parameter-dependent mobility: The ...

    Indian Academy of Sciences (India)

    . The study is for quenching from an uncorrelated high temperature state into the Lifshitz line within the microemulsion phase. In the later stage of the ordering process, the structure factor exhibits multiscaling behavior with characteristic length ...

  3. Analysis for a special first order characteristic equation with delay dependent parameters

    Energy Technology Data Exchange (ETDEWEB)

    Sun Chengjun [Department of Mathematics, Shanghai Jiao Tong University, Shanghai 200240 (China)]. E-mail: cjsun@sjtu.edu.cn; Lin Yiping [Department of Mathematics, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Han Maoan [Department of Mathematics, Shanghai Normal University, Shanghai 200234 (China); Tang Shoupeng [School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2007-07-15

    In this paper, the characteristic equation a({tau}){lambda} + b({tau}) + c({tau}) e{sup -{lambda}}{sup {tau}} + d({tau}) e{sup -2{lambda}}{sup {tau}} = 0 with delay {tau} dependent parameters is investigated. Sufficient and necessary conditions for the existence of a pair of purely imaginary roots are obtained by introducing the auxiliary equations. The crossing directions of eigenvalue curves through the imaginary axis as the delay {tau} increases are determined by the formulae.

  4. Identification of predictor parameters to determine agro-industrial compost suppressiveness against Fusarium oxysporum and Phytophthora capsici diseases in muskmelon and pepper seedlings.

    Science.gov (United States)

    Blaya, Josefa; Lloret, Eva; Ros, Margarita; Pascual, Jose Antonio

    2015-05-01

    The lack of reliable prediction tools for evaluation of the level and specificity of compost suppressiveness limits its application. In our study, different chemical, biological and microbiological parameters were used to evaluate their potential use as a predictor parameter for the suppressive effect of composts against Fusarium oxysporum f. sp. melonis (FOM) and Phytophthora capsici (P. capsici) in muskmelon and pepper seedlings respectively. Composts were obtained from artichoke sludge, chopped vineyard pruning waste and various agro-industrial wastes (C1: blanched artichokes; C2: garlic waste; C3: dry olive cake). Compost C3 proved to offer the highest level of resistance against FOM, and compost C2 the highest level of resistance against P. capsici. Analysis of phospholipid fatty acids isolated from compost revealed that the three composts showed different microbial community structures. Protease, NAGase and chitinase activities were significantly higher in compost C3, as was dehydrogenase activity in compost C2. The use of specific parameters such as general (dehydrogenase activity) and specific enzymatic activities (protease, NAGase and chitinase activities) may be useful to predict compost suppressiveness against both pathogens. The selection of raw materials for agro-industrial composts is important in controlling Fusarium wilt and Phytophthora root rot. © 2014 Society of Chemical Industry.

  5. Relaxation time of the global order parameter on multiplex networks: The role of interlayer coupling in Kuramoto oscillators

    Science.gov (United States)

    Allen-Perkins, Alfonso; de Assis, Thiago Albuquerque; Pastor, Juan Manuel; Andrade, Roberto F. S.

    2017-10-01

    This work considers the time scales associated with the global order parameter and the interlayer synchronization of coupled Kuramoto oscillators on multiplexes. For two-layer multiplexes with an initially high degree of synchronization in each layer, the difference between the average phases in each layer is analyzed from two different perspectives: the spectral analysis and the nonlinear Kuramoto model. Both viewpoints confirm that the prior time scales are inversely proportional to the interlayer coupling strength. Thus, increasing the interlayer coupling always shortens the transient regimes of both the global order parameter and the interlayer synchronization. Surprisingly, the analytical results show that the convergence of the global order parameter is faster than the interlayer synchronization, and the latter is generally faster than the global synchronization of the multiplex. The formalism also outlines the effects of frequencies on the difference between the average phases of each layer, and it identifies the conditions for an oscillatory behavior. Computer simulations are in fairly good agreement with the analytical findings, and they reveal that the time scale of the global order parameter is half the size of the time scale of the multiplex, if not smaller.

  6. Online Parameter Design Method of Adaptive PSS Based on Low-order Linear Model in Multi-area Power System

    Science.gov (United States)

    Sugihara, Toshio; Yokoyama, Akihiko; Izena, Atsushi

    In this study, adaptive PSS using measurable state variables at generator buses is developed. The PSS parameters are tuned based on eigenvalue analysis for a low-order simple linear model of each generator obtained by identification. The low-order model consists of block diagram of PSS and relationship from output of PSS to input of PSS with limited variables which are identified by least squares method using ΔPe and Δω measured at each generator bus. The identification for the PSS parameter tuning is repeated. The PSS parameters are tuned every second to keep power system stable. Digital simulations for transient stability analysis are carried out for IEEJ WEST 10-machine system model. It is made clear that the stability is improved only when dominant oscillation is identified at generator bus.

  7. Higher order corrections to Higgs boson decays in the MSSM with complex parameters

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Karina E. [Bonn Univ. (Germany). Bethe Center for Theoretical Physics; Rzehak, Heidi [Freiburg Univ. (Germany). Physikalisches Inst.; Weiglein, Georg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-03-15

    We discuss Higgs boson decays in the CP-violating MSSM, and examine their phe- nomenological impact using cross section limits from the LEP Higgs searches. This includes a discussion of the full 1-loop results for the partial decay widths of neutral Higgs bosons into lighter neutral Higgs bosons (h{sub a}{yields}h{sub b}h{sub c}) and of neutral Higgs bosons into fermions (h{sub a}{yields}f anti f). In calculating the genuine vertex corrections, we take into account the full spectrum of supersymmetric particles and all complex phases of the supersymmetric parameters. These genuine vertex corrections are supplemented with Higgs propagator corrections incorporating the full one-loop and the dominant two-loop contributions, and we illustrate a method of consistently treating diagrams involving mixing with Goldstone and Z bosons. In particular, the genuine vertex corrections to the process h{sub a}{yields}h{sub b}h{sub c} are found to be very large and, where this process is kinematically allowed, can have a significant effect on the regions of the CPX bench- mark scenario which can be excluded by the results of the Higgs searches at LEP. However, there remains an unexcluded region of CPX parameter space at a lightest neutral Higgs boson mass of {proportional_to}45 GeV. In the analysis, we pay particular attention to the conversion between parameters defined in different renormalisation schemes and are therefore able to make a comparison to the results found using renormalisation group improved/effective potential calculations. (orig.)

  8. Influence of nonstoichiometry and ordering on basic structure parameter of cubic titanium carbide

    International Nuclear Information System (INIS)

    Zueva, L.V.; Gusev, A.I.

    1999-01-01

    Effect of nonstoichiometry and phase transformations of the disorder-order type on the basis (B1 type) structure period of TiC y (0.5 y titanium carbide with formation of the Ti 2 C and Ti 3 C 2 superstructures leads to growth of the basic crystal lattice period as compared to disordered carbide. The problem on trends in static atomic displacement near vacancy is discussed with an account of the lattice period change [ru

  9. Statistical analysis of magnetic parameters in order to discriminate hydrocarbon-related conditions

    Science.gov (United States)

    Aldana, M.; Ñuflo, J.; Costanzo-Alvarez, V.; Guzmán, O.; Guerrero-Suárez, S.; Martín-Hernández, F.; Osete, M. L.

    2012-04-01

    In this work we try to discriminate near surface magnetic anomalies related to hydrocarbon microseepage using just magnetic parameters. We present preliminary results for two oil fields located at Eastern Venezuela and characterized by different geochemical conditions. Cross-plots that combine hysteresis data (Mrs/Ms and Hcr/Hc), Magnetic Susceptibility (MS) and S-ratio were analysed searching for patterns associated with different type of MS anomalies, i.e. related (A type) and not related (B type) to hydrocarbon migration, with different reducing conditions (associated or not with the presence of organic matter) and/or with distinct chief magnetic mineralogies at these MS anomalous levels (i.e. Fe-oxides or Fe-sulphides). K-means and Hierarchical Cluster Analyses were applied and the possibility of pattern recognition, combining more than two magnetic variables, was examined. The results obtained seem to indicate that it is possible to discriminate between anomalies associated with different chief magnetic mineralogies. Nevertheless, the statistical analysis of the parameters applied here does not discriminate between anomalies related to hydrocarbon microseepage and those reflecting just lithological contrasts, or between anomalies associated with different reducing conditions.

  10. Ferro-type order of magneto-electric quadrupoles as an order-parameter for the pseudo-gap phase of a cuprate superconductor

    Science.gov (United States)

    Lovesey, S. W.; Khalyavin, D. D.; Staub, U.

    2015-07-01

    There is general agreement within the community of researchers that investigate high-Tc materials that it is most important to understand the pseudo-gap phase. To this end, many experiments on various cuprates have been reported. Two prominent investigations—Kerr effect and neutron Bragg diffraction—imply that underdoped YBCO samples possess long-range magnetic order of an unusual kind. However, other measurements do not support the existence of magnetic order. Here we show that the Kerr effect and magnetic Bragg diffraction data are individual manifestations of ordered magneto-electric quadrupoles at Cu sites. While the use of magneto-electric multipoles is new in studies of the electronic properties of cuprates, they are not unknown in other materials, including an investigation with x-rays of the parent compound CuO. We exploit the recent prediction that neutrons are deflected by magneto-electric multipoles. The outcome of our study is a theory for the order-parameter of the pseudo-gap phase without the aforementioned conflict with other measurements, and the first experimental evidence that neutrons interact with multipoles belonging to a state of magnetic charge.

  11. Neutron scattering study of the antiferroquadrupolar structure and order parameter of UPd3

    DEFF Research Database (Denmark)

    McEwen, K.A.; Steigenberger, U.; Clausen, K.N.

    1995-01-01

    UPd3 exhibits phase transitions at T-1 approximate to 7 K and T-2 approximate to 5 K. Polarised-neutron diffraction measurements showed that a structural modulation with wavevector (1/2, 0, 0) takes place below T-1. A more detailed neutron-diffraction study of this phase is reported: group......-theory analysis of the results indicates that the ordered phase below T-1 is a triple-q antiferroquadrupolar structure involving Q(x2-y2), Q(xz) and Q(zz) quadrupole moments of the uranium ions....

  12. Josephson scanning tunneling microscopy -- a local and direct probe of the superconducting order parameter

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Hikari; Dynes, Robert; Barber Jr., Richard. P.; Ono, S.; Ando, Y.

    2009-09-01

    Direct measurements of the superconducting superfluid on the surface of vacuum-cleaved Bi2Sr2CaCu2O8+delta (BSCCO) samples are reported. These measurements are accomplished via Josephson tunneling into the sample using a novel scanning tunneling microscope (STM) equipped with a superconducting tip. The spatial resolution of the STM of lateral distances less than the superconducting coherence length allows it to reveal local inhomogeneities in the pair wavefunction of the BSCCO. Instrument performance is demonstrated first with Josephson measurements of Pb films followed by the layered superconductor NbSe2. The relevant measurement parameter, the Josephson ICRN product, is discussed within the context of both BCS superconductors and the high transition temperature superconductors. The local relationship between the ICRN product and the quasiparticle density of states (DOS) gap are presented within the context of phase diagrams for BSCCO. Excessive current densities can be produced with these measurements and have been found to alter the local DOS in the BSCCO. Systematic studies of this effect were performed to determine the practical measurement limits for these experiments. Alternative methods for preparation of the BSCCO surface are also discussed.

  13. Unstable Modes and Order Parameters of Bistable Signaling Pathways at Saddle-Node Bifurcations: A Theoretical Study Based on Synergetics

    Directory of Open Access Journals (Sweden)

    Till D. Frank

    2016-01-01

    Full Text Available Mathematical modeling has become an indispensable part of systems biology which is a discipline that has become increasingly popular in recent years. In this context, our understanding of bistable signaling pathways in terms of mathematical modeling is of particular importance because such bistable components perform crucial functions in living cells. Bistable signaling pathways can act as switches or memory functions and can determine cell fate. In the present study, properties of mathematical models of bistable signaling pathways are examined from the perspective of synergetics, a theory of self-organization and pattern formation founded by Hermann Haken. At the heart of synergetics is the concept of so-called unstable modes or order parameters that determine the behavior of systems as a whole close to bifurcation points. How to determine these order parameters for bistable signaling pathways at saddle-node bifurcation points is shown. The procedure is outlined in general and an explicit example is worked out in detail.

  14. The Spatiotemporal Oscillations of Order Parameter for Isothermal Model of the Surface-Directed Spinodal Decomposition in Bounded Binary Mixtures

    Directory of Open Access Journals (Sweden)

    Igor B. Krasnyuk

    2009-01-01

    Full Text Available The asymptotical behavior of order parameter in confined binary mixture is considered in one-dimensional geometry. The interaction between bulk and surface forces in the mixture is investigated. Its established conditions are when the bulk spinodal decomposition may be ignored and when the main role in the process of formation of the oscillating asymptotic periodic spatiotemporal structures plays the surface-directed spinodal decomposition which is modelled by nonlinear dynamical boundary conditions.

  15. Existence of positive solutions for nonlocal second-order boundary value problem with variable parameter in Banach spaces

    Directory of Open Access Journals (Sweden)

    Zhang Peiguo

    2011-01-01

    Full Text Available Abstract By obtaining intervals of the parameter λ, this article investigates the existence of a positive solution for a class of nonlinear boundary value problems of second-order differential equations with integral boundary conditions in abstract spaces. The arguments are based upon a specially constructed cone and the fixed point theory in cone for a strict set contraction operator. MSC: 34B15; 34B16.

  16. Critical temperature and the transition from quantum to classical order parameter fluctuations in the three-dimensional Heisenberg antiferromagnet

    OpenAIRE

    Sandvik, A. W.

    1998-01-01

    We present results of extensive quantum Monte Carlo simulations of the three-dimensional (3D) S=1/2 Heisenberg antiferromagnet. Finite-size scaling of the spin stiffness and the sublattice magnetization gives the critical temperature Tc/J = 0.946 +/- 0.001. The critical behavior is consistent with the classical 3D Heisenberg universality class, as expected. We discuss the general nature of the transition from quantum mechanical to classical (thermal) order parameter fluctuations at a continuo...

  17. Higher-order mode suppression in rod-type photonic crystal fibers with sectioned doping and enlarged core

    DEFF Research Database (Denmark)

    Poli, F.; Coscelli, E.; Passaro, D.

    2010-01-01

    analyzed with a spatial and spectral amplifier model, showing the positive effect of the gain filtering in improving the fundamental mode amplification, to the detriment of the higher-order mode one. Comparisons have been made with the properties of rod-type fibers with 30 μm core radius, both with uniform...

  18. Dynamical vanishing of the order parameter in a confined Bardeen-Cooper-Schrieffer Fermi gas after an interaction quench

    Science.gov (United States)

    Hannibal, S.; Kettmann, P.; Croitoru, M. D.; Axt, V. M.; Kuhn, T.

    2018-01-01

    We present a numerical study of the Higgs mode in an ultracold confined Fermi gas after an interaction quench and find a dynamical vanishing of the superfluid order parameter. Our calculations are done within a microscopic density-matrix approach in the Bogoliubov-de Gennes framework which takes the three-dimensional cigar-shaped confinement explicitly into account. In this framework, we study the amplitude mode of the order parameter after interaction quenches starting on the BCS side of the BEC-BCS crossover close to the transition and ending in the BCS regime. We demonstrate the emergence of a dynamically vanishing superfluid order parameter in the spatiotemporal dynamics in a three-dimensional trap. Further, we show that the signal averaged over the whole trap mirrors the spatiotemporal behavior and allows us to systematically study the effects of the system size and aspect ratio on the observed dynamics. Our analysis enables us to connect the confinement-induced modifications of the dynamics to the pairing properties of the system. Finally, we demonstrate that the signature of the Higgs mode is contained in the dynamical signal of the condensate fraction, which, therefore, might provide a new experimental access to the nonadiabatic regime of the Higgs mode.

  19. Towards all-order Laurent expansion of generalized hypergeometric functions around rational values of parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kalmykov, M.Yu.; Kniehl, B.A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2008-07-15

    We prove the following theorems: 1) The Laurent expansions in {epsilon} of the Gauss hypergeometric functions {sub 2}F{sub 1}(I{sub 1}+a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z), {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+a{epsilon},I{sub 2}+(p/q)+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z) and {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+ a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z), where I{sub 1},I{sub 2},I{sub 3},p,q are arbitrary integers, a,b,c are arbitrary numbers and {epsilon} is an infinitesimal parameter, are expressible in terms of multiple polylogarithms of q-roots of unity with coefficients that are ratios of polynomials; 2) The Laurent expansion of the Gauss hypergeometric function {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+c{epsilon};z) is expressible in terms of multiple polylogarithms of q-roots of unity times powers of logarithm with coefficients that are ratios of polynomials; 3) The multiple inverse rational sums {sigma}{sup {infinity}}{sub j=1}({gamma}(j))/({gamma}(1+j-(p)/(q))) (z{sup j})/(j{sup c}) S{sub a{sub 1}}(j-1).. S{sub a{sub p}}(j-1) and the multiple rational sums {sigma}{sup {infinity}}{sub j=1} ({gamma}(j+(p)/(q)))/({gamma}(1+j)) (z{sup j})/(j{sup c}) S{sub a{sub 1}}(j-1).. S{sub a{sub p}}(j-1), where S{sub a}(j)={sigma}{sup j}{sub k=1}(1)/(k{sup a}) is a harmonic series and c is an arbitrary integer, are expressible in terms of multiple polylogarithms; 4) The generalized hypergeometric functions {sub p}F{sub p.1}((vector)A+(vector)a{epsilon};(vector)B+(vector)b{epsilon},(p)/(q)+B{sub p-1};z) and {sub p}F{sub p-1}((vector)A+(vector)a{epsilon},(p)/(q)+A{sub p};(vector)B+(vector)b{epsilon};z) are expressible in terms of multiple polylogarithms with coefficients that are ratios of polynomials. (orig.)

  20. Study on generation mechanisms of second-order nonlinear signals in surface acoustic wave devices and their suppression

    Science.gov (United States)

    Nakagawa, Ryo; Kyoya, Haruki; Shimizu, Hiroshi; Kihara, Takashi; Hashimoto, Ken-ya

    2015-07-01

    In this study, we examine the generation mechanisms of the second-order nonlinear signals in surface acoustic wave resonators/duplexers fabricated on a 42°YX-LiTaO3 substrate. It is shown that the crystal asymmetry of the substrate can generate the second-order nonlinear signals. The following two mechanisms mainly contribute to their generation: (a) self-mixing of the electrostatic field and (b) mixing of the electrostatic field with the strain field associated with laterally propagating modes. Both of them occur at the gaps between the electrode tip and the dummy electrode. In addition, an interdigital transducer design that cancels this asymmetry is proposed. The design is applied to a one-port resonator and a duplexer, and the effectiveness of this technique is demonstrated.

  1. Strain and order-parameter coupling in Ni-Mn-Ga Heusler alloys from resonant ultrasound spectroscopy

    Science.gov (United States)

    Salazar Mejía, C.; Born, N.-O.; Schiemer, J. A.; Felser, C.; Carpenter, M. A.; Nicklas, M.

    2018-03-01

    Resonant ultrasound spectroscopy and magnetic susceptibility experiments have been used to characterize strain coupling phenomena associated with structural and magnetic properties of the shape-memory Heusler alloy series Ni50 +xMn25 -xGa25 (x =0 , 2.5, 5.0, and 7.5). All samples exhibit a martensitic transformation at temperature TM and ferromagnetic ordering at temperature TC, while the pure end member (x =0 ) also has a premartensitic transition at TP M, giving four different scenarios: TC>TP M>TM,TC>TM without premartensitic transition, TC≈TM , and TCorder parameters relating to magnetic ordering, a soft mode, and the electronic instability responsible for the large strains typical of martensitic transitions. Linear-quadratic or biquadratic coupling between these order parameters, either directly or indirectly via the common strains, is then used to explain the stabilities of the different structures. Acoustic losses are attributed to critical slowing down at the premartensite transition, to the mobility of interphases between coexisting phases at the martensitic transition, and to mobility of some aspect of the twin walls under applied stress down to the lowest temperatures at which measurements were made.

  2. Order-parameter-aided temperature-accelerated sampling for the exploration of crystal polymorphism and solid-liquid phase transitions

    International Nuclear Information System (INIS)

    Yu, Tang-Qing; Vanden-Eijnden, Eric; Chen, Pei-Yang; Chen, Ming; Samanta, Amit; Tuckerman, Mark

    2014-01-01

    The problem of predicting polymorphism in atomic and molecular crystals constitutes a significant challenge both experimentally and theoretically. From the theoretical viewpoint, polymorphism prediction falls into the general class of problems characterized by an underlying rough energy landscape, and consequently, free energy based enhanced sampling approaches can be brought to bear on the problem. In this paper, we build on a scheme previously introduced by two of the authors in which the lengths and angles of the supercell are targeted for enhanced sampling via temperature accelerated adiabatic free energy dynamics [T. Q. Yu and M. E. Tuckerman, Phys. Rev. Lett. 107, 015701 (2011)]. Here, that framework is expanded to include general order parameters that distinguish different crystalline arrangements as target collective variables for enhanced sampling. The resulting free energy surface, being of quite high dimension, is nontrivial to reconstruct, and we discuss one particular strategy for performing the free energy analysis. The method is applied to the study of polymorphism in xenon crystals at high pressure and temperature using the Steinhardt order parameters without and with the supercell included in the set of collective variables. The expected fcc and bcc structures are obtained, and when the supercell parameters are included as collective variables, we also find several new structures, including fcc states with hcp stacking faults. We also apply the new method to the solid-liquid phase transition in copper at 1300 K using the same Steinhardt order parameters. Our method is able to melt and refreeze the system repeatedly, and the free energy profile can be obtained with high efficiency

  3. An extended Kalman filter approach to non-stationary Bayesian estimation of reduced-order vocal fold model parameters.

    Science.gov (United States)

    Hadwin, Paul J; Peterson, Sean D

    2017-04-01

    The Bayesian framework for parameter inference provides a basis from which subject-specific reduced-order vocal fold models can be generated. Previously, it has been shown that a particle filter technique is capable of producing estimates and associated credibility intervals of time-varying reduced-order vocal fold model parameters. However, the particle filter approach is difficult to implement and has a high computational cost, which can be barriers to clinical adoption. This work presents an alternative estimation strategy based upon Kalman filtering aimed at reducing the computational cost of subject-specific model development. The robustness of this approach to Gaussian and non-Gaussian noise is discussed. The extended Kalman filter (EKF) approach is found to perform very well in comparison with the particle filter technique at dramatically lower computational cost. Based upon the test cases explored, the EKF is comparable in terms of accuracy to the particle filter technique when greater than 6000 particles are employed; if less particles are employed, the EKF actually performs better. For comparable levels of accuracy, the solution time is reduced by 2 orders of magnitude when employing the EKF. By virtue of the approximations used in the EKF, however, the credibility intervals tend to be slightly underpredicted.

  4. In situ removal of carbon contamination from a chromium-coated mirror: ideal optics to suppress higher-order harmonics in the carbon K-edge region.

    Science.gov (United States)

    Toyoshima, Akio; Kikuchi, Takashi; Tanaka, Hirokazu; Mase, Kazuhiko; Amemiya, Kenta

    2015-11-01

    Carbon-free chromium-coated optics are ideal in the carbon K-edge region (280-330 eV) because the reflectivity of first-order light is larger than that of gold-coated optics while the second-order harmonics (560-660 eV) are significantly suppressed by chromium L-edge and oxygen K-edge absorption. Here, chromium-, gold- and nickel-coated mirrors have been adopted in the vacuum ultraviolet and soft X-ray branch beamline BL-13B at the Photon Factory in Tsukuba, Japan. Carbon contamination on the chromium-coated mirror was almost completely removed by exposure to oxygen at a pressure of 8 × 10(-2) Pa for 1 h under irradiation of non-monochromated synchrotron radiation. The pressure in the chamber recovered to the order of 10(-7) Pa within a few hours. The reflectivity of the chromium-coated mirror of the second-order harmonics in the carbon K-edge region (560-660 eV) was found to be a factor of 0.1-0.48 smaller than that of the gold-coated mirror.

  5. A Smoothing Method with Appropriate Parameter Control Based on Fischer-Burmeister Function for Second-Order Cone Complementarity Problems

    Directory of Open Access Journals (Sweden)

    Yasushi Narushima

    2013-01-01

    Full Text Available We deal with complementarity problems over second-order cones. The complementarity problem is an important class of problems in the real world and involves many optimization problems. The complementarity problem can be reformulated as a nonsmooth system of equations. Based on the smoothed Fischer-Burmeister function, we construct a smoothing Newton method for solving such a nonsmooth system. The proposed method controls a smoothing parameter appropriately. We show the global and quadratic convergence of the method. Finally, some numerical results are given.

  6. Order parameters for symmetry-breaking structural transitions: The tetragonal-monoclinic transition in ZrO2

    Science.gov (United States)

    Thomas, John C.; Van der Ven, Anton

    2017-10-01

    Group/subgroup structural phase transitions are exploited in a wide variety of technologies, including those that rely on shape-memory behavior and on transformation toughening. Here, we introduce an approach to identify symmetry-adapted strain and shuffle order parameters for any group/subgroup structural transition between a high-symmetry parent phase and its symmetrically equivalent low-symmetry product phases. We show that symmetry-adapted atomic shuffle order parameters can be determined by the diagonalization of an orbital covariance matrix, formed by taking the covariance among the atomic displacement vectors of all symmetrically equivalent product phase variants. We use this approach to analyze the technologically important tetragonal to monoclinic structural phase transformation of ZrO2. We explore the energy landscapes, as calculated with density functional theory, along distinct paths that connect m ZrO2 to t ZrO2 and to other m ZrO2 variants. The calculations indicate favorable pairs of variants and reveal intermediate structures likely to exist at coherent twin boundaries and having relatively low deformation energy. We identify crystallographic features of the monoclinic ZrO2 variant that make it very sensitive to shape changing strains.

  7. Derivation and solution of a time-dependent, nonlinear, Schrodinger-like equation for the superconductivity order parameter

    International Nuclear Information System (INIS)

    Esrick, M.A.

    1981-01-01

    A time-dependent, nonlinear, Schrodinger-like equation for the superconductivity order parameter is derived from the Gor'kov equations. Three types of traveling wave solutions of the equation are discussed. The phases and amplitudes of these solutions propagate at different speeds. The first type of solution has an amplitude that propagates as a soliton and it is suggested that this solution might correspond to the recently observed propagating collective modes of the order parameter. The amplitude of the second type of solution propagates as a periodic disturbance in space and time. It is suggested that this type of solution might explain the recently observed multiple values of the superconductor energy gap as well as the spatially inhomogenous superconducting state. The third type of solution, which is of a more general character, might provide some insight into non-periodic, inhomogeneous states occuring in superconductors. It is also proposed that quasiparticle injection and microwave irradiation might generate soliton-like disturbances in superconductors

  8. Improved Hybrid Fireworks Algorithm-Based Parameter Optimization in High-Order Sliding Mode Control of Hypersonic Vehicles

    Directory of Open Access Journals (Sweden)

    Xiaomeng Yin

    2018-01-01

    Full Text Available With respect to the nonlinear hypersonic vehicle (HV dynamics, achieving a satisfactory tracking control performance under uncertainties is always a challenge. The high-order sliding mode control (HOSMC method with strong robustness has been applied to HVs. However, there are few methods for determining suitable HOSMC parameters for an efficacious control of HV, given that the uncertainties are randomly distributed. In this study, we introduce a hybrid fireworks algorithm- (FWA- based parameter optimization into HV control design to satisfy the design requirements with high probability. First, the complex relation between design parameters and the cost function that evaluates the likelihood of system instability and violation of design requirements is modeled via stochastic robustness analysis. Subsequently, we propose an efficient hybrid FWA to solve the complex optimization problem concerning the uncertainties. The efficiency of the proposed hybrid FWA-based optimization method is demonstrated in the search of the optimal HV controller, in which the proposed method exhibits a better performance when compared with other algorithms.

  9. Assessment of reduced-order unscented Kalman filter for parameter identification in 1-dimensional blood flow models using experimental data.

    Science.gov (United States)

    Caiazzo, A; Caforio, Federica; Montecinos, Gino; Muller, Lucas O; Blanco, Pablo J; Toro, Eluterio F

    2016-10-25

    This work presents a detailed investigation of a parameter estimation approach on the basis of the reduced-order unscented Kalman filter (ROUKF) in the context of 1-dimensional blood flow models. In particular, the main aims of this study are (1) to investigate the effects of using real measurements versus synthetic data for the estimation procedure (i.e., numerical results of the same in silico model, perturbed with noise) and (2) to identify potential difficulties and limitations of the approach in clinically realistic applications to assess the applicability of the filter to such setups. For these purposes, the present numerical study is based on a recently published in vitro model of the arterial network, for which experimental flow and pressure measurements are available at few selected locations. To mimic clinically relevant situations, we focus on the estimation of terminal resistances and arterial wall parameters related to vessel mechanics (Young's modulus and wall thickness) using few experimental observations (at most a single pressure or flow measurement per vessel). In all cases, we first perform a theoretical identifiability analysis on the basis of the generalized sensitivity function, comparing then the results owith the ROUKF, using either synthetic or experimental data, to results obtained using reference parameters and to available measurements. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Why we still don't know the symmetry of the order parameter in high temperature superconductors

    International Nuclear Information System (INIS)

    Klemm, R.A.

    1997-03-01

    One of the most elusive topics in the study of high temperature superconductors (HTCS) is the orbital symmetry of the superconducting order parameter Δ. The low temperature T behavior observed in many experiments suggests that Δ might exhibit line nodes, as expected for d x-y 2 orbital symmetry. However, such behavior also arises from intrinsic proximity coupling and surface states, etc. The paramagnetic Meissner effect, once cited as indirect evidence for a d-wave Δ, was recently observed in Nb. Some phase-sensitive Josephson junction experiments gave strong evidence for a substantial isotropic, or s-wave, component to Δ, whereas others supported the above d-wave form. However, such experiments are intrinsically unreliable in experimental geometries with sample corners, or with meandering grain boundary junctions and stoichiometry inhomogeneities. Finally, the pseudogap observed recently in underdoped HTCS could arise from a charge-density wave

  11. Sign reversal of the order parameter in (Li1-xFex)OHFe1-yZnySe

    Science.gov (United States)

    Du, Zengyi; Yang, Xiong; Altenfeld, Dustin; Gu, Qiangqiang; Yang, Huan; Eremin, Ilya; Hirschfeld, Peter J.; Mazin, Igor I.; Lin, Hai; Zhu, Xiyu; Wen, Hai-Hu

    2018-02-01

    Iron pnictides are the only known family of unconventional high-temperature superconductors besides cuprates. Until recently, it was widely accepted that superconductivity is driven by spin fluctuations and intimately related to the fermiology, specifically, hole and electron pockets separated by the same wavevector that characterizes the dominant spin fluctuations, and supporting order parameters (OP) of opposite signs. This picture was questioned after the discovery of intercalated or monolayer form of FeSe-based systems without hole pockets, which seemingly undermines the basis for spin-fluctuation theory and the idea of a sign-changing OP. Using the recently proposed phase-sensitive quasiparticle interference technique, here we show that in LiOH-intercalated FeSe compound the OP does change sign, albeit within the electronic pockets. This result unifies the pairing mechanism of iron-based superconductors with or without the hole Fermi pockets and supports the conclusion that spin fluctuations play the key role in electron pairing.

  12. Optimization of first order decay gas generation model parameters for landfills located in cold semi-arid climates.

    Science.gov (United States)

    Vu, Hoang Lan; Ng, Kelvin Tsun Wai; Richter, Amy

    2017-11-01

    Canada has one of the highest waste generation rates in the world. Because of high land availability, land disposal rates in the province of Saskatchewan are high compared to the rest of the country. In this study, landfill gas data was collected at semi-arid landfills in Regina and Saskatoon, Saskatchewan, and curve fitting was carried out to find optimal k and L o or DOC values using LandGEM, Afvalzorg Simple, and IPCC first order decay models. Model parameters at each landfill were estimated and compared using default k and L o or DOC values. Methane generation rates were substantially overestimated using default values (with percentage errors from 55 to 135%). The mean percentage errors for the optimized k and L o or DOC values ranged from 11.60% to 19.93% at the Regina landfill, and 1.65% to 10.83% at the Saskatoon landfill. Finally, the effect of different iterative methods on the curve fitting process was examined. The residual sum of squares for each model and iterative approaches were similar, with the exception of iterative method 1 for the IPCC model. The default values in these models fail to represent landfills located in cold semi-arid climates. The use of site specific data, provided enough information is available regarding waste mass and composition, can greatly help to improve the accuracy of these first order decay models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The order parameter of glass transition: Spontaneously delocalized nanoscale solitary wave with transverse ripplon-like soft wave

    Directory of Open Access Journals (Sweden)

    Jia Lin Wu

    2013-06-01

    Full Text Available In macromolecular self-avoiding random walk, movement of each chain-particle accompanies an instantaneous spin system with de Gennes n = 0 that provides extra energy, extra vacancy volume and relaxation time needed for chain-particles co-movement. Using these additional and instantaneous spin systems not only directly yields the same Brownian motion mode in glass transition (GT and reptation-tube model, but also proves that the entangled chain length corresponding to the Reynolds number in hydrodynamics and the inherent diffusion - delocalization mode of entangled chains, from frozen glass state to melt liquid state, is a chain-size solitary wave with transverse ripplon-like soft wave. Thus, the order parameter of GT is found. The various currently available GT theories, such as Static Replica, Random First-Order Transition, Potential Energy Landscape, Mode-Coupling and Nanoscale Heterogeneity, can be unified using the additional and instantaneous spin system. GT served as an inspiration and continues to serve as the paradigm in the universal random delocalization transitions from disorder to more disorder until turbulence.

  14. Onset of local ordering in some copper-based alloys: critical solute concentration vis-a-vis various solutionhardening parameters

    Science.gov (United States)

    Butt, Muhammad Zakria; Noshi, Mozina; Bashir, Farooq

    2008-12-01

    The mode of planar distribution of solute atoms in Cu single crystals alloyed with 0.5 to 8.0 at.%Ge has been investigated via the temperature dependence of the critical resolved shear stress of these alloys. It is found that there exists a critical solute concentration c m ≈ 5 at.%Ge below which the distribution of solute atoms in the crystal is random, and above which some local ordering occurs. This together with such data available in the literature for Cu-Zn, Cu-Al and Cu-Mn alloys, i.e. c m ≈7 at. %Zn, 7 at.%Al and 1 at.%Mn, when examined as a function of the size-misfit factor δ = (1/ b)(d b/d c)of a given binary alloy system, shows that the value of c m strongly depends on δ; the smaller the magnitude of δ, the greater the value of c m and vice versa. Also, the value of c m is found to correlate well with the electron-to-atom ratio ( e/a)of the Cu-Zn, Cu-Al, Cu-Ge and Cu-Mn alloys with the solute concentration c = c m . However, no systematic correlation exists between the critical solute concentration c m for the onset of local ordering and the modulus-mismatch parameter η = (1/ G)(d G/d c).

  15. The Intramolecular Pressure and the Extension of the Critical Point’s Influence Zone on the Order Parameter

    Directory of Open Access Journals (Sweden)

    Jose Luis Rivera

    2015-01-01

    Full Text Available The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone covers up to hundreds of degrees below the critical temperature. Here we show that, for ethane, the experimental critical influence zone covers a wide zone of tens of degrees (below the critical temperature down to a transition temperature, at which the apparent critical influence zone vanishes, and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase, using a simple molecular potential. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, Molecular Dynamics simulations reveal that the experimentally observed wide extension of the critical influence zone is the result of a vapor-like effect due to low bulk liquid phase densities.

  16. ℋ− adaptive observer design and parameter identification for a class of nonlinear fractional-order systems

    KAUST Repository

    Ndoye, Ibrahima

    2014-12-01

    In this paper, an adaptive observer design with parameter identification for a nonlinear system with external perturbations and unknown parameters is proposed. The states of the nonlinear system are estimated by a nonlinear observer and the unknown parameters are also adapted to their values. Sufficient conditions for the stability of the adaptive observer error dynamics are derived in terms of linear matrix inequalities. Simulation results for chaotic Lorenz systems with unknown parameters in the presence of external perturbations are given to illustrate the effectiveness of our proposed approach. © 2014 IEEE.

  17. First-order exchange coefficient coupling for simulating surface water-groundwater interactions: Parameter sensitivity and consistency with a physics-based approach

    Science.gov (United States)

    Ebel, B.A.; Mirus, B.B.; Heppner, C.S.; VanderKwaak, J.E.; Loague, K.

    2009-01-01

    Distributed hydrologic models capable of simulating fully-coupled surface water and groundwater flow are increasingly used to examine problems in the hydrologic sciences. Several techniques are currently available to couple the surface and subsurface; the two most frequently employed approaches are first-order exchange coefficients (a.k.a., the surface conductance method) and enforced continuity of pressure and flux at the surface-subsurface boundary condition. The effort reported here examines the parameter sensitivity of simulated hydrologic response for the first-order exchange coefficients at a well-characterized field site using the fully coupled Integrated Hydrology Model (InHM). This investigation demonstrates that the first-order exchange coefficients can be selected such that the simulated hydrologic response is insensitive to the parameter choice, while simulation time is considerably reduced. Alternatively, the ability to choose a first-order exchange coefficient that intentionally decouples the surface and subsurface facilitates concept-development simulations to examine real-world situations where the surface-subsurface exchange is impaired. While the parameters comprising the first-order exchange coefficient cannot be directly estimated or measured, the insensitivity of the simulated flow system to these parameters (when chosen appropriately) combined with the ability to mimic actual physical processes suggests that the first-order exchange coefficient approach can be consistent with a physics-based framework. Copyright ?? 2009 John Wiley & Sons, Ltd.

  18. The order parameter and susceptibility of the 3D Ising-like system in an external field near the phase transition point

    Directory of Open Access Journals (Sweden)

    M.P. Kozlovskii

    2010-01-01

    Full Text Available The present work is devoted to the investigation of the 3D Ising-like model in the presence of an external field in the vicinity of critical point. The method of collective variables is used. General expressions for the order parameter and susceptibility are calculated as functions of temperature and the external field as well as scaling functions of that are explicitly obtained. The results are compared with the ones obtained within the framework of parametric representation of the equation of state and Monte Carlo simulations. New expression for the exit point from critical regime of the order parameter fluctuations is proposed and used for the calculation.

  19. What Does the Field Dependence of the Thermal Conductivity of the Heavy Fermion Superconductor UPt3 Tell Us about the Symmetry of the Order Parameter?

    International Nuclear Information System (INIS)

    Houssa, M.; Ausloos, M.

    1997-01-01

    We investigate the field dependence of the thermal conductivity κ of UPt 3 single crystals for magnetic fields applied along the basal (ab) plane and along the c axis, respectively. The effect of heat carrying electrons scattered by quasiparticle excitations in the vortex cores is calculated for an anisotropic superconducting gap parameter of either E 1g or E 2u symmetry. It is shown that the anisotropy of the field dependence of κ allows one to probe the symmetry of the superconducting order parameter and favors the E 2u gap parameter, i.e., with quadratic point nodes along the c axis. copyright 1997 The American Physical Society

  20. What Does the Field Dependence of the Thermal Conductivity of the Heavy Fermion Superconductor UPt3 Tell Us about the Symmetry of the Order Parameter?

    Science.gov (United States)

    Houssa, M.; Ausloos, M.

    1997-10-01

    We investigate the field dependence of the thermal conductivity κ of UPt3 single crystals for magnetic fields applied along the basal (ab) plane and along the c axis, respectively. The effect of heat carrying electrons scattered by quasiparticle excitations in the vortex cores is calculated for an anisotropic superconducting gap parameter of either E1g or E2u symmetry. It is shown that the anisotropy of the field dependence of κ allows one to probe the symmetry of the superconducting order parameter and favors the E2u gap parameter, i.e., with quadratic point nodes along the c axis.

  1. Competing order parameters in quenched random alloys: Fe/sub 1-x/Co/sub x/Cl2

    International Nuclear Information System (INIS)

    Wong, P.; Horn, P.M.; Birgeneau, R.J.; Safinya, C.R.; Shirane, G.

    1980-01-01

    A study is reported of the magnetic properties of the random alloy Fe/sub 1-x/Co/sub x/Cl 2 , which represents an archetypal example of a system with competing orthogonal spin anisotropies. Behavior similar to previous experiments and theoretical predictions is found, but with important qualitative and quantitative differences; in particular the phase transition in one variable is drastically altered by the existence of long-range order in the other variable. It is hypothesized that this is due to microscopic random-field effects

  2. Determination of first-order machine parameters from particle physics requirements. Group 1. Summary report. Primary parametric relationships. I

    International Nuclear Information System (INIS)

    Diebold, R.

    1984-01-01

    High luminosity will be necessary for the study of many of the new phenomena expected in the SSC energy region. Particle detectors, however, are limited in the number of simultaneous interactions which they can handle, and thus need a good duty cycle with collisions spread out in time to the greatest extent possible. To avoid the larger number of stored protons required for continuous beams, we have considered bunched beams of protons crossing at a small angle. Plots are given of the dependence on bunch separation of the emittance, number of protons, etc., needed for 10 33 cm -2 sec -1 . In order to minimize the number of stored protons (approx. 10 14 /ring), an emittance roughly ten times smaller than that presently achieved at high energies is required for a bunch separation of 6 meters (20 nsec)

  3. Microstructural parameters and high third order nonlinear absorption characteristics of Mn-doped PbS/PVA nanocomposite films

    Science.gov (United States)

    Ramezanpour, B.; Mahmoudi Chenari, Hossein; Sadigh, M. Khadem

    2017-11-01

    In this work, undoped and Mn-doped PbS/PVA nanocomposite films have been successfully fabricated using the simple solution-casting method. Their crystalline structure was examined by X-ray powder diffraction (XRD). XRD pattern show the formation of cubic structure of PbS for Mn-doped PbS in PVA matrix. Microstructure parameters of Mn-doped PbS/PVA nanocomposite films were obtained through the size-strain plot (SSP) method. The thermal stability of the nanocomposite film was determined using Thermogravimetric analysis (TGA). Furthermore, Z-scan technique was used to investigate the optical nonlinearity of nanocomposite films by a continuous-wave laser irradiation at the wavelength of 655 nm. This experimental results show that undoped PbS/PVA nanocomposite films indicate high nonlinear absorption characteristics. Moreover, the nanocomposite films with easy preparation characteristics, high thermal stability and nonlinear absorption properties can be used as an active element in optics and photonic devices.

  4. Neutron scattering studies of competing magnetic and superconducting order parameters in Ba(Fe1-xCox)2As2

    Science.gov (United States)

    Pratt, Daniel; Fernandez, Rafael; Tian, Wei; Zaretsky, Jerel; Kreyssig, Andreas; Nandi, Shibabrata; Kim, Min Gyu; Thaler, Alex; Ni, Ni; Bud'Ko, Sergey; Canfield, Paul; McQueeney, Robert; Schmalian, Jorg; Goldman, Alan

    2010-03-01

    Neutron and x-ray diffraction studies show that the simultaneous first-order transition to an orthorhombic and antiferromagnetic (AFM) ordered state in BaFe2As2 splits into two transitions, and TN as well as the ordered moment decrease as x (%Co) increases. Recent experiments have demonstrated that for a range of doping, superconductivity and magnetism co-exist homogeneously and compete for electrons. The magnetic order parameters have been measured for a series of Co doping from x = 0 to 6.3% and a clear drop in sublattice magnetization is observed at TC for each compound. Comparison of these measurements to mean field calculations has provided insight into these competing order parameters. The good agreement between the measurement and calculations show that neutron scattering is a useful probe for understanding the symmetry of the superconducting gap in the iron-arsenide superconductors.^ The work at the Ames Laboratory was supported by the US DOE, office of science, under contract No. DE-AC02-07CH11358.

  5. The strange-quark chemical potential as an experimentally accessible 'order parameter' of the deconfinement phase transition for finite baryon density

    International Nuclear Information System (INIS)

    Panagiotou, Apostolos D; Katsas, Panayiotis G

    2003-01-01

    We consider the change of the strange-quark chemical potential in the phase diagram of nuclear matter, employing the Wilson loop and scalar quark condensate order parameters, mass-scaled partition functions and enforcing flavour conservation. Assuming the region beyond the hadronic phase to be described by massive, correlated and interacting quarks, in the spirit of lattice and effective QCD calculations, we find the strange-quark chemical potential to change sign: from positive in the hadronic phase, to zero upon deconfinement, to negative in the partonic domain. We propose this change in the sign of the strange-quark chemical potential to be an experimentally accessible order parameter and a unique, concise and well-defined indication of the quark-deconfinement phase transition in nuclear matter

  6. Phase-sensitive order parameter symmetry test experiments utilizing Nd2-xCexCuO4-y/Nb zigzag junctions

    NARCIS (Netherlands)

    Ariando, A.; Darminto, D.; Darminto, D.; Smilde, H.J.H.; Leca, V.; Blank, David H.A.; Rogalla, Horst; Hilgenkamp, Johannes W.M.

    2005-01-01

    Phase-sensitive order parameter symmetry test experiments are presented on the electron-doped high-Tc cuprate Nd2-xCexCuO4-y. These experiments have been conducted using zigzag-shaped thin film Josephson structures, in which the Nd2-xCexCuO4-y is connected to the low-Tc superconductor Nb via an Au

  7. Spontaneous piezoelectric effect as order parameter in (NH{sub 4}){sub 2}CuBr{sub 4}·2H{sub 2}O crystal

    Energy Technology Data Exchange (ETDEWEB)

    Tylczyński, Z., E-mail: zbigtyl@amu.edu.pl; Wiesner, M.; Trzaskowska, A.

    2016-11-01

    Temperature change of piezoelectric properties of (NH{sub 4}){sub 2}CuBr{sub 4}·2H{sub 2}O crystal in the low-temperature ferroelastoelectric phase is studied. The macroscopic order parameter is proved to be the h{sub 36} component of the spontaneous piezoelectric tensor. The critical exponent related with the phase transition is α=0.60±0.05.

  8. Modulational instability and higher-order rogue waves with parameters modulation in a coupled integrable AB system via the generalized Darboux transformation.

    Science.gov (United States)

    Wen, Xiao-Yong; Yan, Zhenya

    2015-12-01

    We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.

  9. Observations of multiple order parameters in 5f electron systems; Observations de parametres d'ordre multiples dans les systemes d'electrons 5f

    Energy Technology Data Exchange (ETDEWEB)

    Blackburn, E

    2005-12-15

    In this thesis, multiple order parameters originating in the same electronic system are studied. The multi-k magnetic structures, where more than one propagation wavevector, k, is observed in the same volume, are considered as prototypical models. The effect of this structure on the elastic and inelastic response is studied. In cubic 3-k uranium rock-salts, unexpected elastic diffraction events were observed at positions in reciprocal space where the structure factor should have been zero. These diffraction peaks are identified with correlations between the (orthogonal) magnetic order parameters. The 3-k structure also affects the observed dynamics; the spin-wave fluctuations in uranium dioxide as observed by inelastic neutron polarization analysis can only be explained on the basis of a 3-k structure. In the antiferromagnetic superconductor UPd{sub 2}Al{sub 3} the magnetic order and the super-conducting state coexist, and are apparently generated by the same heavy fermions. The effect of an external magnetic field on both the normal and superconducting states is examined. In the normal state, the compound displays Fermi-liquid-like behaviour. The inelastic neutron response is strongly renormalized on entering the superconducting state, and high-precision measurements of the low-energy transfer part of this response confirm that the superconducting energy gap has the same symmetry as the antiferromagnetic lattice. (author)

  10. Optimization of pulsed laser welding process parameters in order to attain minimum underfill and undercut defects in thin 316L stainless steel foils

    Science.gov (United States)

    Pakmanesh, M. R.; Shamanian, M.

    2018-02-01

    In this study, the optimization of pulsed Nd:YAG laser welding parameters was done on the lap-joint of a 316L stainless steel foil with the aim of reducing weld defects through response surface methodology. For this purpose, the effects of peak power, pulse-duration, and frequency were investigated. The most important weld defects seen in this method include underfill and undercut. By presenting a second-order polynomial, the above-mentioned statistical method was managed to be well employed to balance the welding parameters. The results showed that underfill increased with the increased power and reduced frequency, it first increased and then decreased with the increased pulse-duration; and the most important parameter affecting it was the power, whose effect was 65%. The undercut increased with the increased power, pulse-duration, and frequency; and the most important parameter affecting it was the power, whose effect was 64%. Finally, by superimposing different responses, improved conditions were presented to attain a weld with no defects.

  11. Suppressed Belief

    Directory of Open Access Journals (Sweden)

    Komarine Romdenh-Romluc

    2009-12-01

    Full Text Available Moran’s revised conception of conscious belief requires us to reconceptualise suppressed belief. The work of Merleau-Ponty offers a way to do this. His account of motor-skills allows us to understand suppressed beliefs as pre-reflective ways of dealing with the world.

  12. Competing superconducting and magnetic order parameters and field-induced magnetism in electron doped Ba(Fe1-xCox)2As2

    DEFF Research Database (Denmark)

    Larsen, Jacob; Uranga, B. Mencia; Stieber, G.

    2015-01-01

    We have studied the magnetic and superconducting properties of Ba(Fe1-xCox)2As2 as a function of temperature and external magnetic field using neutron scattering and muon spin rotation. Below the superconducting transition temperature the magnetic and superconducting order parameters coexist...... and compete. A magnetic field can significantly enhance the magnetic scattering in the superconducting state, roughly doubling the Bragg intensity at 13.5 T. We perform a microscopic modelling of the data by use of a five-band Hamiltonian relevant to iron pnictides. In the superconducting state, vortices can...... slow down and freeze spin fluctuations locally. When such regions couple they result in a long-range ordered antiferromagnetic phase producing the enhanced magnetic elastic scattering in agreement with experiments....

  13. X-ray determination of site occupation parameters in ordered ternaries Cu(AuxM1-x)M = Ni,Pd

    International Nuclear Information System (INIS)

    Kumar, R.; Sparks, C.J.; Specht, E.D.; Zschack, P.; Ice, G.E.; Shiraishi, T.; Hisatsune, K.

    1990-01-01

    X-ray scattering data obtained for multiple wavelengths with synchrotron radiation were analyzed by the Rietveld method to determine Ni and Pd distributions on the Cu(000) and Au(1/2 1/2 1/2) sites in the CuAuI tetragonal P4/mmm structure. Alloys of CuAu x M 1-x containing 6 at. % Ni or 10 and 25 at. % Pd were processed to obtain maximum ordering. Nickel is predominantly found on the Cu size and most all the Pd is found on the Au site. The uncertainty in site occupation parameters is discussed for various contributions which affect powder intensity measurements. For highly absorbing materials, an observed powder roughness effect decreases the low angle (2θ) intensities relative to the high 2θ intensities. This effect reduces the reliability of the thermal parameters and obscure a proper description of the thermal motion of the two sublattices. Corrections to the X-ray intensity data for surface roughness/porosity effects reduce uncertainties to about ±1 at. % on the refined value of the site occupations. This use of variable wavelength X-rays with simultaneous refinement of the corresponding data is capable of distinguishing site occupations even between two elements of almost equal scattering factor as, for example, Cu and Ni atoms in this investigation. Chemical phase stability is related to the site occupation parameters. 9 refs., 3 figs., 2 tabs

  14. Chalcone Synthase (CHS) Gene Suppression in Flax Leads to Changes in Wall Synthesis and Sensing Genes, Cell Wall Chemistry and Stem Morphology Parameters

    Science.gov (United States)

    Zuk, Magdalena; Działo, Magdalena; Richter, Dorota; Dymińska, Lucyna; Matuła, Jan; Kotecki, Andrzej; Hanuza, Jerzy; Szopa, Jan

    2016-01-01

    The chalcone synthase (CHS) gene controls the first step in the flavonoid biosynthesis. In flax, CHS down-regulation resulted in tannin accumulation and reduction in lignin synthesis, but plant growth was not affected. This suggests that lignin content and thus cell wall characteristics might be modulated through CHS activity. This study investigated the possibility that CHS affects cell wall sensing as well as polymer content and arrangement. CHS-suppressed and thus lignin-reduced plants showed significant changes in expression of genes involved in both synthesis of components and cell wall sensing. This was accompanied by increased levels of cellulose and hemicellulose. CHS-reduced flax also showed significant changes in morphology and arrangement of the cell wall. The stem tissue layers were enlarged averagely twofold compared to the control, and the number of fiber cells more than doubled. The stem morphology changes were accompanied by reduction of the crystallinity index of the cell wall. CHS silencing induces a signal transduction cascade that leads to modification of plant metabolism in a wide range and thus cell wall structure. PMID:27446124

  15. Theory of Metastable State Relaxation in a Gravitational Field for Non-Critical Binary Systems with Non-Conserved Order Parameter

    Science.gov (United States)

    Izmailov, Alexander F.; Myerson, Allan S.

    1993-01-01

    A new mathematical ansatz is developed for solution of the time-dependent Ginzburg-Landau nonlinear partial differential equation describing metastable state relaxation in binary (solute+solvent) non-critical solutions with non-conserved scalar order parameter in presence of a gravitational field. It has been demonstrated analytically that in such systems metastability initiates heterogeneous solute redistribution which results in the formation of a non-equilibrium singly-periodic spatial solute structure in the new solute-rich phase. The critical radius of nucleation and the induction time in these systems are gravity-dependent. It has also been proved that metastable state relaxation in vertical columns of supersaturated non-critical binary solutions leads to formation of the solute concentration gradient. Analytical expression for this concentration gradient is found and analysed. It is concluded that gravity can initiate phase separation (nucleation or spinodal decomposition).

  16. Manipulating multiple order parameters via oxygen vacancies: The case of E u0.5B a0.5Ti O3 -δ

    Science.gov (United States)

    Li, Weiwei; He, Qian; Wang, Le; Zeng, Huizhong; Bowlan, John; Ling, Langsheng; Yarotski, Dmitry A.; Zhang, Wenrui; Zhao, Run; Dai, Jiahong; Gu, Junxing; Shen, Shipeng; Guo, Haizhong; Pi, Li; Wang, Haiyan; Wang, Yongqiang; Velasco-Davalos, Ivan A.; Wu, Yangjiang; Hu, Zhijun; Chen, Bin; Li, Run-Wei; Sun, Young; Jin, Kuijuan; Zhang, Yuheng; Chen, Hou-Tong; Ju, Sheng; Ruediger, Andreas; Shi, Daning; Borisevich, Albina Y.; Yang, Hao

    2017-09-01

    Controlling functionalities, such as magnetism or ferroelectricity, by means of oxygen vacancies (VO) is a key issue for the future development of transition-metal oxides. Progress in this field is currently addressed through VO variations and their impact on mainly one order parameter. Here we reveal a mechanism for tuning both magnetism and ferroelectricity simultaneously by using VO. Combining experimental and density-functional theory studies of E u0.5B a0.5Ti O3 -δ , we demonstrate that oxygen vacancies create T i3 +3 d1 defect states, mediating the ferromagnetic coupling between the localized Eu 4 f7 spins, and increase an off-center displacement of Ti ions, enhancing the ferroelectric Curie temperature. The dual function of Ti sites also promises a magnetoelectric coupling in the E u0.5B a0.5Ti O3 -δ .

  17. Relativistic spin-polarized KKR theory for superconducting heterostructures: Oscillating order parameter in the Au layer of Nb/Au/Fe trilayers

    Science.gov (United States)

    Csire, Gábor; Deák, András; Nyári, Bendegúz; Ebert, Hubert; Annett, James F.; Újfalussy, Balázs

    2018-01-01

    The fully relativistic spin-polarized multiple-scattering theory is developed for inhomogeneous superconductors, including superconducting/normal-metal/ferromagnet heterostructures. The method allows the solution of the first-principles Dirac-Bogoliubov-de Gennes equations combined with a semiphenomenological parametrization of the exchange-correlation functional. Simple conditions are derived for the case when the right-hand-side and left-hand-side solutions must be treated separately when setting up the corresponding Green's function. As an application of the theory, we calculate the order parameters of Nb/Fe and Nb/Au/Fe systems. We find Fulde-Ferrell-Larkin-Ovchinnikov-like oscillations in the iron layers, but more interestingly an oscillatory behavior is observed in the gold layers as well. The band-structure calculations suggest that this is the consequence of an interplay between the quantum-well states and ferromagnetism.

  18. Coarsening in 3D nonconserved Ising model at zero temperature: Anomaly in structure and slow relaxation of order-parameter autocorrelation

    Science.gov (United States)

    Chakraborty, Saikat; Das, Subir K.

    2017-09-01

    Via Monte Carlo simulations we study pattern and aging during coarsening in a nonconserved nearest-neighbor Ising model, following quenches from infinite to zero temperature, in space dimension d = 3. The decay of the order-parameter autocorrelation function appears to obey a power-law behavior, as a function of the ratio between the observation and waiting times, in the large ratio limit. However, the exponent of the power law, estimated accurately via a state-of-the-art method, violates a well-known lower bound. This surprising fact has been discussed in connection with a quantitative picture of the structural anomaly that the 3D Ising model exhibits during coarsening at zero temperature. These results are compared with those for quenches to a temperature above that of the roughening transition.

  19. Evidence for the suppression of intermediate anti-ferroelectric ordering and observation of hardening mechanism in Na{sub 1/2}Bi{sub 1/2}TiO{sub 3} ceramics through cobalt substitution

    Energy Technology Data Exchange (ETDEWEB)

    Thangavelu, Karthik [Advanced Functional Materials Laboratory, Department of Physics, Indian Institute of Technology Hyderabad, Andhra Pradesh - 502 205, India. (India); Department of Materials Science and Engineering, Indian Institute of Technology Hyderabad, Andhra Pradesh - 502 205, India. (India); Ramadurai, Ranjith [Department of Materials Science and Engineering, Indian Institute of Technology Hyderabad, Andhra Pradesh - 502 205, India. (India); Asthana, Saket, E-mail: asthanas@iith.ac.in [Advanced Functional Materials Laboratory, Department of Physics, Indian Institute of Technology Hyderabad, Andhra Pradesh - 502 205, India. (India)

    2014-01-15

    Co-ion (5 mol %) substitution in Na{sub 1/2}Bi{sub 1/2}TiO{sub 3} (NBT) host lattice and their effects on the structural, ferroelectric and dielectric behavior has been investigated thoroughly in this present study. The substituted Co-ion at Ti-site acts an acceptor type doping and hardens (i.e., increase in coercivity) the system without any noticeable change in the remanent polarization values. However, the intermediate antiferroelectric (AFE) ordering which exists between 200 °C–280 °C in NBT system has been suppressed due to Co-ion substitution, which is an interesting feature for device applications.

  20. Flight validated high-order models of UAV helicopter dynamics in hover and forward flight using analytical and parameter identification techniques

    Science.gov (United States)

    Bhandari, Subodh

    There has been a significant growth in the use of UAV helicopters for a multitude of military and civilian applications over the last few years. Due to these numerous applications, from crop dusting to remote sensing, UAV helicopters are now a major topic of interest within the aerospace community. The main research focus is on the development of automatic flight control systems (AFCS). The design of AFCS for these vehicles requires a mathematical model representing the dynamics of the vehicle. The mathematical model is developed either from first-principles, using the equations of motion of the vehicle, or from the flight data, using parameter identification techniques. The traditional six-degrees-of-freedom (6-DoF) dynamics model is not suitable for high-bandwidth control system design. Such models are valid only within the low- to mid-frequency range. The agility and high maneuverability of small-scale helicopters require a high-bandwidth control system for full authority autonomous performance. The design of a high-bandwidth control system in turn requires a high-fidelity simulation model that is able to capture the key dynamics of the helicopter. These dynamics include the rotor dynamics. This dissertation presents the development of a 14-degrees-of-freedom (14-DoF) state-space linear model for the KU Thunder Tiger Raptor 50 UAV helicopter from first-principles and from flight test data using a parameter identification technique for the hovering and forward flight conditions. The model includes rigid body, rotor regressive, rotor inflow, stabilizer bar, and rotor coning dynamics. The model is implemented within The MathWork's MATLAB/Simulink environment. The simulation results show that the high-order model is able to predict the helicopter's dynamics up to the frequency of 30 rad/sec. The main contributions of this dissertation are the development of a high-order simulation model for a small UAV helicopter from first-principles and the identification of a

  1. Finite-part integration of the generalized Stieltjes transform and its dominant asymptotic behavior for small values of the parameter. I. Integer orders

    Science.gov (United States)

    Tica, Christian D.; Galapon, Eric A.

    2018-02-01

    The paper addresses the exact evaluation of the generalized Stieltjes transform Sn[f ] =∫0∞f (x ) (ω+x ) -nd x of integral order n = 1, 2, 3, … about ω = 0 from which the asymptotic behavior of Sn[f] for small parameters ω is directly extracted. An attempt to evaluate the integral by expanding the integrand (ω + x)-n about ω = 0 and then naively integrating the resulting infinite series term by term leads to an infinite series whose terms are divergent integrals. Assigning values to the divergent integrals, say, by analytic continuation or by Hadamard's finite part is known to reproduce only some of the correct terms of the expansion but completely misses out a group of terms. Here we evaluate explicitly the generalized Stieltjes transform by means of finite-part integration recently introduced in Galapon [Proc. R. Soc. A 473, 20160567 (2017)]. It is shown that, when f(x) does not vanish or has zero of order m at the origin such that (n - m) ≥ 1, the dominant terms of Sn[f] as ω → 0 come from contributions arising from the poles and branch points of the complex valued function f(z)(ω + z)-n. These dominant terms are precisely the terms missed out by naive term by term integration. Furthermore, it is demonstrated how finite-part integration leads to new series representations of special functions by exploiting their known Stieltjes integral representations. Finally, the application of finite part integration in obtaining asymptotic expansions of the effective diffusivity in the limit of high Peclet number, the Green-Kubo formula for the self-diffusion coefficient, and the antisymmetric part of the diffusion tensor in the weak noise limit is discussed.

  2. Mixed H ∞ and Passive Projective Synchronization for Fractional Order Memristor-Based Neural Networks with Time-Delay and Parameter Uncertainty

    Science.gov (United States)

    Song, Xiao-Na; Song, Shuai; Tejado Balsera, Inés; Liu, Lei-Po

    2017-10-01

    This paper investigates the mixed H ∞ and passive projective synchronization problem for fractional-order (FO) memristor-based neural networks. Our aim is to design a controller such that, though the unavoidable phenomena of time-delay and parameter uncertainty are fully considered, the resulting closed-loop system is asymptotically stable with a mixed H ∞ and passive performance level. By combining active and adaptive control methods, a novel hybrid control strategy is designed, which can guarantee the robust stability of the closed-loop system and also ensure a mixed H ∞ and passive performance level. Via the application of FO Lyapunov stability theory, the projective synchronization conditions are addressed in terms of linear matrix inequality techniques. Finally, two simulation examples are given to illustrate the effectiveness of the proposed method. Supported by National Natural Science Foundation of China under Grant Nos. U1604146, U1404610, 61473115, 61203047, Science and Technology Research Project in Henan Province under Grant Nos. 152102210273, 162102410024, and Foundation for the University Technological Innovative Talents of Henan Province under Grant No. 18HASTIT019

  3. Suppression chamber

    International Nuclear Information System (INIS)

    Goto, Hiroshi; Tsuji, Akio.

    1976-01-01

    Purpose: To miniaturize the storage tank of condensated water in BWR reactor. Constitution: A diaphragm is provided in a suppression chamber thereby to partition the same into an inner compartment and an outer compartment. In one of said compartments there is stored clean water to be used for feeding at the time of separating the reactor and for the core spray system, and in another compartment there is stored water necessary for accomplishing the depressurization effect at the time of coolant loss accident. To the compartment in which clean water is stored there is connected a water cleaning device for constantly maintaining water in clean state. As this cleaning device an already used fuel pool cleaning device can be utilized. Further, downcomers for accomplishing the depressurization function are provided in both inner compartment and outer compartment. The capacity of the storage tank can be reduced by the capacity of clean water within the suppression chamber. (Ikeda, J.)

  4. Magnetism in the iron-based superconductors: The determination of spin-nematic fluctuations as the primary order parameter and its implications for unconventional superconductivity

    Science.gov (United States)

    Taddei, Keith M.

    ordering of this phase-separated state will be elucidated and the superconductivity attributed to a pseudo-stable minority phase. Detailed phase diagrams will be constructed for the related BaFe2(As1--xPx) 2 and Sr1--xNaxFe2 As2 compounds leading to a direct comparison of the effects driving of either doping regime. A strong magneto-elastic coupling will be established in both of these materials and a new magnetic phase will be mapped in Sr1--xNaxFe2As2. These observations will lead to a discussion of the role of magnetic fluctuations in the overall behavior of the material. The results of inelastic and elastic diffraction experiments will be combined with the results of the local probe M?ssbauer spectroscopy technique in order to determine magnetic fluctuations as the primary order parameter in the phase evolution of the iron-based superconductors, and therefore their importance in establishment of superconductivity as the ground state of these materials.

  5. Parameter sensitivity of high-order equivalent circuit models of turbine generator; Sensibilidad parametrica de modelos de circuitos equivalentes de orden superior de turbogeneradores

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Garcia, I.; Escalera Perez, R. [Universidad Autonoma Metropolitana - Azcapotzalco (Mexico)]. E-mail: irvinlopez@yahoo.com; r.escalera@ieee.org; Niewierowicz Swiecicka, T. [Instituto Politecnico Nacional, U.P. Adolfo Lopez Mateos (Mexico)]. E-mail: tniewi@ipn.mx; Campero Littlewood, E.[Universidad Autonoma Metropolitana - Azcapotzalco (Mexico)]. E-mail: ecl@correo.azc.uam.mx

    2010-01-15

    This work shows the results of a parametric sensitivity analysis applied to a state-space representation of high-order two-axis equivalent circuits (Ecs) of a turbo generator (150 MVA, 120 MW, 13.8 kV y 50 Hz). The main purpose of this study is to evaluate each parameter impact on the transient response of the analyzed two axis models -d axis Ecs with one to five damper branches and q axis Ecs from one to four damper branches-. The parametric sensitivity concept is formulated in a general context and the sensibility function is established from the generator response to a short circuit condition. Results ponder the importance played by each parameter in the model behavior. The algorithms were design within MATLAB environment. The study gives way to conclusion on electromagnetic aspects of solid rotor synchronous generators that have not been previously studied. The methodology presented here can be applied to any other physical system. [Spanish] En este trabajo se presentan los resultados del analisis de sensibilidad parametrica realizado a modelos de circuitos equivalentes de orden superior de un turbogenerador (150 MVA, 120 MW, 13.8 kV y 50 Hz). La representacion del generador sincrono se hace en el espacio de estados, utilizando la teoria de dos ejes (d y a). El objetivo del estudio de sensibilidad es evaluar el impacto que tiene cada uno de los parametros en la respuesta transitoria de los modelos analizados -circuitos equivalentes desde una hasta cinco ramas de amortiguamiento en el eje d y de una a cuatro ramas en el eje q-. En este trabajo el concepto de sensibilidad parametrica se formula en terminos generales, planteando la funcion de sensibilidad a partir de condiciones de cortocircuito en las terminales del generador. Los resultados se presentan senalando el nivel de importancia de cada parametro en el comportamiento del modelo. Los algoritmos utilizados fueron disenados en MATLAB. Asi, este estudio permite inferir aspectos electromagneticos de los

  6. Separate Kinetics of the Polar and Antiferrodistortive Order Parameters in the Antiferroelectric Transition of PbZr1-xTixO3 and the Influence of Defects

    Directory of Open Access Journals (Sweden)

    Cordero F.

    2015-04-01

    Full Text Available The transition from the rhombohedral-ferroelectric to the lower temperature orthorhombic-antiferroelectric phase in Zr-rich PZT involves two order parameters (OPs: 1 the polar OP for the displacements of the cations with respect to the O octahedra; 2 an antiferrodistortive OP responsible for tilting of the octahedra. It is shown that at Ti compositions near the morphotropic boundary with the FE phase (0.046 ≤ x ≤ 0.054, the two OPs may be almost independent of each other at cooling rates of 0.5 K/min or faster, depending on the sample history. This fact gives rise to a great variety of shapes of the curves of the elastic compliance s(T, but all of them can be fitted very well as superpositions of variously broadened steps for each of the modes involved in the transitions, including the tilt transition occurring in the untransformed FE fraction. The evolution of the s(T curves includes enhancements up to a factor of four during aging for weeks in the region of the AFE/FE coexistence. Restiffening and reduction of the thermal hysteresis of the AFE/FE transition are recovered by heating up to 800-900 K. It is proposed that ageing is due to the clustering of relatively mobile defects, most likely O vacancies, at the domain walls in the coexisting AFE/FE phases. Such defect structures are probably at the origin of intense thermally activated relaxation processes observed above TC in the dielectric and anelastic spectra, and can be annealed out above 800 K, allowing the AFE transition to recover a fast kinetics.

  7. Temperature and pressure dependence of the order parameter fluctuations, conformational compressibility, and the phase diagram of the PEP-PDMS diblock copolymer

    DEFF Research Database (Denmark)

    Schwahn, D.; Frielinghaus, H.; Mortensen, K.

    1996-01-01

    The structure factor of a poly(ethylene-propylene)-poly(dimethylsiloxane) diblock copolymer has been measured by small-angle neutron scattering as a function of temperature and pressure. The conformational compressibility exhibits a pronounced maximum at the order-disorder phase transition. The p...

  8. Positron annihilation study of the electronic structure of URu.sub.2./sub.Si.sub.2./sub.: Fermi surface and hidden order parameter

    Czech Academy of Sciences Publication Activity Database

    Biasini, M.; Rusz, Ján; Mills, A.

    2009-01-01

    Roč. 79, č. 8 (2009), 085115/1-085115/10 ISSN 1098-0121 Institutional research plan: CEZ:AV0Z10100520 Keywords : positron annihilation * 2D-ACAR * URu 2 Si 2 * density functional theory * hidden order * Fermi surface Subject RIV: BE - Theoretical Physics Impact factor: 3.475, year: 2009 http://prb.aps.org/abstract/PRB/v79/i8/e085115

  9. Theoretical and experimental study of ions focusing systems in order to improve the ions beam brightness by suppressing aberration causes; Etude theorique et experimentale de la focalisation des ions afin d'ameliorer la brillance du faisceau ionique par la suppression des causes d'aberration

    Energy Technology Data Exchange (ETDEWEB)

    Faure, J

    1966-07-01

    It is shown that a beam brightness can be improved by an order of magnitude when the sources of aberrations are suppressed in the anode region source, as well as in the extraction region and in the electrostatic focusing system. A calculation was first set up to determine a simple focusing system. The aberration ratio due to this focusing system is smaller than 10 to 15 per cent. The experimental study was developed by using an ion source and its extraction system capable of producing an aberration free beam at an energy of 20 keV and an accelerating unit up to 190 keV that confirms that the qualities of a 35 mA beam produced by the said ion source are not spoiled when the beam goes through the focusing and accelerating system that was designed to be aberration free. (author) [French] Dans ce travail, on s'attache a demontrer que la brillance d'un faisceau peut etre amelioree d'un ordre de grandeur lorsque l'on supprime les causes d'aberration aussi bien a la sortie de la source, dans la zone d'extraction, que dans le systeme de focalisation electrostatique. Un calcul est, tout d'abord, mis au point pour determiner un systeme de focalisation simple. Cette focalisation n'entraine pas un taux d'aberrations superieur a 10 ou 15 pour cent. Puis l'etude experimentale conduit: a) a la realisation d'une source et de son systeme d'extraction fournissant un faisceau sans aberration a une energie de 20 keV. b) et a l'elaboration d'un petit accelerateur a 190 keV qui verifie que les proprietes d'un faisceau de 35 mA issu de la source ne sont pas affectees par la traversee des systemes focalisateur et accelerateur lorsque ceux-ci n'apportent pas d'aberration. (auteur)

  10. Rotated stripe order and its competition with superconductivity in La1.88Sr0.12CuO4

    DEFF Research Database (Denmark)

    Thampy, V.; Dean, M. P. M.; Christensen, Niels Bech

    2014-01-01

    ordering is not pinned to the Cu-O bond direction. On cooling through the superconducting transition, we find an abrupt change in the growth of the charge correlations and a suppression of the charge order parameter indicating competition between the two orderings. Orthorhombic LSCO thus helps bridge...

  11. A physics-based fractional order model and state of energy estimation for lithium ion batteries. Part II: Parameter identification and state of energy estimation for LiFePO4 battery

    Science.gov (United States)

    Li, Xiaoyu; Pan, Ke; Fan, Guodong; Lu, Rengui; Zhu, Chunbo; Rizzoni, Giorgio; Canova, Marcello

    2017-11-01

    State of energy (SOE) is an important index for the electrochemical energy storage system in electric vehicles. In this paper, a robust state of energy estimation method in combination with a physical model parameter identification method is proposed to achieve accurate battery state estimation at different operating conditions and different aging stages. A physics-based fractional order model with variable solid-state diffusivity (FOM-VSSD) is used to characterize the dynamic performance of a LiFePO4/graphite battery. In order to update the model parameter automatically at different aging stages, a multi-step model parameter identification method based on the lexicographic optimization is especially designed for the electric vehicle operating conditions. As the battery available energy changes with different applied load current profiles, the relationship between the remaining energy loss and the state of charge, the average current as well as the average squared current is modeled. The SOE with different operating conditions and different aging stages are estimated based on an adaptive fractional order extended Kalman filter (AFEKF). Validation results show that the overall SOE estimation error is within ±5%. The proposed method is suitable for the electric vehicle online applications.

  12. Inventory parameters

    CERN Document Server

    Sharma, Sanjay

    2017-01-01

    This book provides a detailed overview of various parameters/factors involved in inventory analysis. It especially focuses on the assessment and modeling of basic inventory parameters, namely demand, procurement cost, cycle time, ordering cost, inventory carrying cost, inventory stock, stock out level, and stock out cost. In the context of economic lot size, it provides equations related to the optimum values. It also discusses why the optimum lot size and optimum total relevant cost are considered to be key decision variables, and uses numerous examples to explain each of these inventory parameters separately. Lastly, it provides detailed information on parameter estimation for different sectors/products. Written in a simple and lucid style, it offers a valuable resource for a broad readership, especially Master of Business Administration (MBA) students.

  13. Suppressed Charmed B Decay

    Energy Technology Data Exchange (ETDEWEB)

    Snoek, Hella Leonie [Vrije Univ., Amsterdam (Netherlands)

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  14. Growth hormone suppression test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003376.htm Growth hormone suppression test To use the sharing features on this page, please enable JavaScript. The growth hormone suppression test determines whether growth hormone production is ...

  15. The study of superconducting order parameter dynamics

    International Nuclear Information System (INIS)

    Goldman, A.M.

    1988-01-01

    Flux quantization experiments have demonstrated the importance of long range phase coherence in the description of the superconducting state, an idea originally proposed as an integral part of the phenomenological theory of the Meissner-Ochsenfeld effect. The most striking experimental demonstration of the phase coherence of the superconducting state is that the maximum dc Josephson current in a thin-film tunneling junction exhibits a Fraunhofer-like dependence on magnetic field

  16. The high temperature superconductor YBa2Cu3O7-δ: symmetry of the order parameter, and gradiometers for biomagnetic applications

    Energy Technology Data Exchange (ETDEWEB)

    Kouznetsov, Konstantin Alexander [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1999-12-01

    The cuprate YBa2Cu3O7-δ is the material that drives the majority of the technological applications of high transition temperature (Tc) superconductors, particularly in the area of superconducting electronics. Despite the widespread use of high-Tc superconducting materials in a variety of applications, the nature of the superconducting state in these materials remains unknown since their discovery more than a decade ago. Many properties of the high-Tc superconductors are determined by their order parameter, which is a wavefunction describing the superconducting condensate. The symmetry of the order parameter in cuprates has been the subject of intensive investigation, leading to conflicting sets of results. Some experiments supported conventional, s-wave symmetry of the order parameter, while others indicated an unconventional, d-wave symmetry. The first part of this thesis is an experimental study of the symmetry of the order parameter in YBa2Cu3O7-δ. A new class of phase sensitive experiments is described that involve Josephson tunneling along the c-axis of twinned crystals of YBa2Cu3O7-δ. These experiments showed that an s-wave component must reverse sign across the twin boundary, providing direct evidence for a mixed, s+d symmetry of the order parameter in YBa2Cu3O7-δ, and thereby reconciling two conflicting sets of previous findings and establishing the dominant d-wave pairing symmetry. The second part of the thesis focuses on practical applications of YBa2Cu3O7-δ in superconducting electronics. The authors introduce a novel Superconducting Quantum Interference Device (SQUID) gradiometer. The principle of operation of these long baseline high-T{sub c} SQUID gradiometers is based on the inductive coupling of the input coil of a planar flux transformer to the

  17. Suppression factors in diffractive photoproduction of dijets

    International Nuclear Information System (INIS)

    Klasen, Michael; Kramer, Gustav

    2010-06-01

    After new publications of H1 data for the diffractive photoproduction of dijets, which overlap with the earlier published H1 data and the recently published data of the ZEUS collaboration, have appeared, we have recalculated the cross sections for this process in next-to-leading order (NLO) of perturbative QCD to see whether they can be interpreted consistently. The results of these calculations are compared to the data of both collaborations. We find that the NLO cross sections disagree with the data, showing that factorization breaking occurs at that order. If direct and resolved contributions are both suppressed by the same amount, the global suppression factor depends on the transverse-energy cut. However, by suppressing only the resolved contribution, also reasonably good agreement with all the data is found with a suppression factor independent of the transverse-energy cut. (orig.)

  18. Quadratic dynamical decoupling with nonuniform error suppression

    International Nuclear Information System (INIS)

    Quiroz, Gregory; Lidar, Daniel A.

    2011-01-01

    We analyze numerically the performance of the near-optimal quadratic dynamical decoupling (QDD) single-qubit decoherence errors suppression method [J. West et al., Phys. Rev. Lett. 104, 130501 (2010)]. The QDD sequence is formed by nesting two optimal Uhrig dynamical decoupling sequences for two orthogonal axes, comprising N 1 and N 2 pulses, respectively. Varying these numbers, we study the decoherence suppression properties of QDD directly by isolating the errors associated with each system basis operator present in the system-bath interaction Hamiltonian. Each individual error scales with the lowest order of the Dyson series, therefore immediately yielding the order of decoherence suppression. We show that the error suppression properties of QDD are dependent upon the parities of N 1 and N 2 , and near-optimal performance is achieved for general single-qubit interactions when N 1 =N 2 .

  19. Influence of non-integer order parameter and Hartmann number on the heat and mass transfer flow of a Jeffery fluid over an oscillating vertical plate via Caputo-Fabrizio time fractional derivatives

    Science.gov (United States)

    Butt, A. R.; Abdullah, M.; Raza, N.; Imran, M. A.

    2017-10-01

    In this work, semi analytical solutions for the heat and mass transfer of a fractional MHD Jeffery fluid over an infinite oscillating vertical plate with exponentially heating and constant mass diffusion via the Caputo-Fabrizio fractional derivative are obtained. The governing equations are transformed into dimensionless form by introducing dimensionless variables. A modern definition of the Caputo-Fabrizio derivative has been used to develop the fractional model for a Jeffery fluid. The expressions for temperature, concentration and velocity fields are obtained in the Laplace transformed domain. We have used the Stehfest's and Tzou's algorithm for the inverse Laplace transform to obtain the semi analytical solutions for temperature, concentration and velocity fields. In the end, in order to check the physical impact of flow parameters on temperature, concentration and velocity fields, results are presented graphically and in tabular forms.

  20. Pressure suppression device

    International Nuclear Information System (INIS)

    Ichiki, Tadaharu; Funahashi, Toshihiro.

    1976-01-01

    Purpose: To provide a structure which permits the absorption of shocks and vibratory load produced on the floor of a pressure suppression chamber due to nitrogen gas or the like discharged into pool water in the pressure suppression chamber at the time of a loss-of-coolant accident. Constitution: A pressure suppression chamber accommodating pool water is comprised of a bottom wall and side walls constructed of concrete on the inner side of a liner. By providing concrete on the bottom surface and side wall surfaces of a pressure suppression chamber, it is possible to prevent non-condensing gas and steam exhausted from the vent duct and exhaust duct of a main vapor escapement safety valve exhaust duct from exerting impact forces and vibratory forces upon the bottom and side surfaces of the pressure suppression chamber. (Horiuchi, T.)

  1. Temporal order of RNase IIIb and loss-of-function mutations during development determines phenotype in pleuropulmonary blastoma / DICER1 syndrome: a unique variant of the two-hit tumor suppression model [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Mark Brenneman

    2018-01-01

    Full Text Available Pleuropulmonary blastoma (PPB is the most frequent pediatric lung tumor and often the first indication of a pleiotropic cancer predisposition, DICER1 syndrome, comprising a range of other individually rare, benign and malignant tumors of childhood and early adulthood. The genetics of DICER1-associated tumorigenesis are unusual in that tumors typically bear neomorphic missense mutations at one of five specific “hotspot” codons within the RNase IIIb domain of DICER 1, combined with complete loss of function (LOF in the other allele. We analyzed a cohort of 124 PPB children for predisposing DICER1 mutations and sought correlations with clinical phenotypes. Over 70% have inherited or de novo germline LOF mutations, most of which truncate the DICER1 open reading frame. We identified a minority of patients who have no germline mutation, but are instead mosaic for predisposing DICER1 mutations. Mosaicism for RNase IIIb domain hotspot mutations defines a special category of DICER1 syndrome patients, clinically distinguished from those with germline or mosaic LOF mutations by earlier onsets and numerous discrete foci of neoplastic disease involving multiple syndromic organ sites. A final category of PBB patients lack predisposing germline or mosaic mutations and have sporadic (rather than syndromic disease limited to a single PPB tumor bearing tumor-specific RNase IIIb and LOF mutations. We propose that acquisition of a neomorphic RNase IIIb domain mutation is the rate limiting event in DICER1-associated tumorigenesis, and that distinct clinical phenotypes associated with mutational categories reflect the temporal order in which LOF and RNase IIIb domain mutations are acquired during development.

  2. Volatile suppressing method for radioactive iodine

    International Nuclear Information System (INIS)

    Ohara, Atsushi; Haruguchi, Keiko.

    1997-01-01

    In the present invention, a metal plate is disposed above the pool water surface of a suppression chamber disposed to a reactor container in order to reduce evaporation of radioactive iodine released from a suppression pool. A metal plate is disposed above the pool water surface of the suppression chamber disposed to the reactor container. In addition, a metal plate is disposed around the space connecting a bent tube extending from a dry well to underwater of suppression pool water and a gas bent tube extending from the suppression chamber to an emergency gas processing system. Spray water is supplied for cooling the suppression chamber d as a means for cooling the metal plate. Then, among iodine released to the suppression chamber, elemental iodine liberated from the pool water is deposited on the surface of the metal plate, and the amount of iodine to be flown into and processed by an emergency gas processing system or a filter bent system can be reduced. (T.M.)

  3. Word Order

    DEFF Research Database (Denmark)

    Rijkhoff, Jan

    2015-01-01

    The way constituents are ordered in a linguistic expression is determined by general principles and language specific rules. This article is mostly concerned with general ordering principles and the three main linguistic categories that are relevant for constituent order research: formal, functio...

  4. Menstrual suppression for adolescents.

    Science.gov (United States)

    Altshuler, Anna Lea; Hillard, Paula J Adams

    2014-10-01

    The purpose of this review is to highlight the recent literature and emerging data describing clinical situations in which menstrual suppression may improve symptoms and quality of life for adolescents. A variety of conditions occurring frequently in adolescents and young adults, including heavy menstrual bleeding, and dysmenorrhea as well as gynecologic conditions such as endometriosis and pelvic pain, can safely be improved or alleviated with appropriate menstrual management. Recent publications have highlighted the efficacy and benefit of extended cycle or continuous combined oral contraceptives, the levonorgestrel intrauterine device, and progestin therapies for a variety of medical conditions. This review places menstrual suppression in an historical context, summarizes methods of hormonal therapy that can suppress menses, and reviews clinical conditions for which menstrual suppression may be helpful.

  5. Cryogenic Acoustic Suppression Testing

    Data.gov (United States)

    National Aeronautics and Space Administration — A proof-of-concept method utilizing a cryogenic fluid for acoustic suppression in rocket engine testing environments will be demonstrated. It is hypothesized that...

  6. Sodium fire suppression

    International Nuclear Information System (INIS)

    Malet, J.C.

    1979-01-01

    Ignition and combustion studies have provided valuable data and guidelines for sodium fire suppression research. The primary necessity is to isolate the oxidant from the fuel, rather than to attempt to cool the sodium below its ignition temperature. Work along these lines has led to the development of smothering tank systems and a dry extinguishing powder. Based on the results obtained, the implementation of these techniques is discussed with regard to sodium fire suppression in the Super-Phenix reactor. (author)

  7. Suppression and control of leakage field in electromagnetic helical microwiggler

    Energy Technology Data Exchange (ETDEWEB)

    Ohigashi, N. [Kansai Univ., Osaka (Japan); Tsunawaki, Y. [Osaka Sangyo Univ. (Japan); Imasaki, K. [Institute for Laser Technology, Osaka (Japan)] [and others

    1995-12-31

    Shortening the period of electromagnetic wiggler introduces both the radical increase of the leakage field and the decrease of the field in the gap region. The leakage field is severer problem in planar electromagnetic wiggler than in helical wiggler. Hence, in order to develop a short period electromagnetic wiggler, we have adopted {open_quotes}three poles per period{close_quotes} type electromagnetic helical microwiggler. In this work, we inserted the permanent magnet (PM) blocks with specific magnetized directions in the space between magnetic poles, for suppressing the leakage field flowing out from a pole face to the neighboring pole face. These PM-blocks must have higher intrinsic coersive force than saturation field of pole material. The gap field due to each pole is adjustable by controlling the leakage fields, that is, controlling the position of each iron screw set in each retainer fixing the PM-blocks. At present time, a test wiggler with period 7.8mm, periodical number 10 and gap length 4.6mm has been manufactured. Because the ratio of PM-block aperture to gap length is important parameter to suppress the leakage field, the parameter has been surveyed experimentally for PM-blocks with several dimensions of aperture. The field strength of 3-5kG (K=0.2-0.4) would be expected in the wiggler.

  8. Why expressive suppression does not pay? Cognitive costs of negative emotion suppression: The mediating role of subjective tense-arousal

    Directory of Open Access Journals (Sweden)

    Szczygieł Dorota

    2015-09-01

    Full Text Available The aim of this paper was to contribute to a broader understanding of the cognitive consequences of expressive suppression. Specifically, we examined whether the deteriorating effect of expressive suppression on cognitive functioning is caused by tense arousal enhanced by suppression. Two experiments were performed in order to test this prediction. In both studies we tested the effect of expressive suppression on working memory, as measured with a backwards digit-span task (Study 1, N = 43 and anagram problem-solving task (Study 2, N = 60. In addition, in Study 2 we tested whether expressive suppression degrades memory of the events that emerged during the period of expressive suppression. Both studies were conducted in a similar design: Participants watched a film clip which evoked negative emotions (i.e. disgust in Study 1 and a combination of sadness and anxiety in Study 2 under the instruction to suppress those negative emotions or (in the control condition to simply watch the film. The results of these experiments lead to three conclusions. First, the results reveal that expressive suppression degrades memory of the events that emerged during the period of expressive suppression and leads to poorer performance on working memory tasks, as measured with a backwards digit-span task and anagram problem-solving task. Second, the results indicate that expressive suppression leads to a significant increase in subjective tense arousal. Third, the results support our prediction that expressive suppression decreases cognitive performance through its effects on subjective tense arousal. The results of the Study 1 show that tense arousal activated during expressive suppression of disgust fully mediates the negative effect of suppression on working memory as measured with a backwards digit-span task. The results of Study 2 reveal that subjective tense arousal elicited while suppressing sadness and anxiety mediates both the effect of suppression on

  9. Variability of the 15N chemical shielding tensors in the B3 domain of protein G from 15N relaxation measurements at several fields. Implications for backbone order parameters.

    Science.gov (United States)

    Hall, Jennifer B; Fushman, David

    2006-06-21

    We applied a combination of 15N relaxation and CSA/dipolar cross-correlation measurements at five magnetic fields (9.4, 11.7, 14.1, 16.4, and 18.8 T) to determine the 15N chemical shielding tensors for backbone amides in protein G in solution. The data were analyzed using various model-independent approaches and those based on Lipari-Szabo approximation, all of them yielding similar results. The results indicate a range of site-specific values of the anisotropy (CSA) and orientation of the 15N chemical shielding tensor, similar to those in ubiquitin (Fushman, et al. J. Am. Chem. Soc. 1998, 120, 10947; J. Am. Chem. Soc. 1999, 121, 8577). Assuming a Gaussian distribution of the 15N CSA values, the mean anisotropy is -173.9 to -177.2 ppm (for 1.02 A NH bond length) and the site-to-site CSA variability is +/-17.6 to +/-21.4 ppm, depending on the method used. This CSA variability is significantly larger than derived previously for ribonuclease H (Kroenke, et al. J. Am. Chem. Soc. 1999, 121, 10119) or recently, using "meta-analysis" for ubiquitin (Damberg, et al. J. Am. Chem. Soc. 2005, 127, 1995). Standard interpretation of 15N relaxation studies of backbone dynamics in proteins involves an a priori assumption of a uniform 15N CSA. We show that this assumption leads to a significant discrepancy between the order parameters obtained at different fields. Using the site-specific CSAs obtained from our study removes this discrepancy and allows simultaneous fit of relaxation data at all five fields to Lipari-Szabo spectral densities. These findings emphasize the necessity of taking into account the variability of 15N CSA for accurate analysis of protein dynamics from 15N relaxation measurements.

  10. Pressure suppression device

    International Nuclear Information System (INIS)

    Mizumachi, Wataru; Fukuda, Akira; Kitaguchi, Hidemi; Shimizu, Toshiaki.

    1976-01-01

    Object: To relieve and absorb impact wave vibrations caused by steam and non-condensed gases releasing into the pressure suppression chamber at the time of an accident. Structure: The reactor container is filled with inert gases. A safety valve attached main steam pipe is provided to permit the excessive steam to escape, the valve being communicated with the pressure suppression chamber through an exhaust pipe. In the pressure suppression chamber, a doughnut-like cylindrical outer wall is filled at its bottom with pool water to condense the high temperature vapor released through the exhaust pipe. A head portion of a vent tube which leads the exhaust pipe is positioned at the top, and a down comer and an exhaust vent tube are locked by means of steady rests. At the bottom is mounted a pressure adsorber device which adsorbs a pressure from the pool water. (Kamimura, M.)

  11. Suppression of Quantum Corrections by Classical Backgrounds

    CERN Document Server

    Brouzakis, Nikolaos

    2014-01-01

    We use heat-kernel techniques in order to compute the one-loop effective action in the cubic Galileon theory for a background that realizes the Vainshtein mechanism. We find that the UV divergences are suppressed relative to the predictions of standard perturbation theory at length scales below the Vainshtein radius.

  12. Thyroxin hormone suppression treatment

    International Nuclear Information System (INIS)

    Samuel, A.M.

    1999-01-01

    One of the important modalities of treatment of thyroid cancer (TC) after surgery is the administration of thyroxin as an adjuvant treatment. The analysis supports the theory that thyroid suppression plays an important role in patient management. 300 μg of thyroxin, as this is an adequate dose for suppression is given. Ideally the dose should be tailored by testing s-TSH levels. However, since a large number of the patients come from out station cities and villages this is impractical. We therefore depend on clinical criteria of hyperthyroid symptoms and adjust the dose. Very few patients need such adjustment

  13. Weed suppression ability of spring barley varieties

    DEFF Research Database (Denmark)

    Christensen, Svend

    1995-01-01

    Three years of experiments with spring barley showed significant differences in weed suppression ability among varieties. Weed dry matter in the most suppressive variety, Ida, was 48% lower than the mean weed dry matter of all varieties, whereas it was 31% higher in the least suppressive variety......, Grit. Ranking varietal responses to weed competition in terms of grain yield loss corresponded well to ranking weed dry matter produced in crop weed mixtures. There was no correspondence between the varietal grain yields in pure stands and their competitiveness, suggesting that breeding to optimize...... interception model was developed to describe the light interception profiles of the varieties. A study of the estimated parameters showed significant correlation between weed dry matter, rate of canopy height development and the light interception profile. However, when estimates were standardized to eliminate...

  14. Neutron diffraction studies of magnetic ordering in superconducting ErNi2B2C and TmNi2B2C in an applied magnetic field

    DEFF Research Database (Denmark)

    Toft, Katrine Nørgaard

    The field-induced magnetic structures of ErNi2B2C and TmNi2B2C in are especially interesting because the field suppresses the superconducting order parameter and therefore the magnetic properties can be studied while varying the strength ofsuperconductivity. ErNi2B2C: For magnetic fields along al...

  15. Plasma suppression of beamstrahlung

    International Nuclear Information System (INIS)

    Whittum, D.H.; Sessler, A.M.; Stewart, J.J.; Yu, S.S.

    1988-06-01

    We investigate the use of a plasma at the interaction point of two colliding beams to suppress beamsstrahlung and related phenomena. We derive conditions for good current cancellation via plasma return currents and report on numerical simulations conducted to confirm our analytic results. 10 refs., 5 figs., 4 tabs

  16. Dynamics of superconducting order parameter through ultrafast normal-to-superconducting phase transition in Bi2Sr2CaCu2O8 +δ from multipulse polarization-resolved transient optical reflectivity

    Science.gov (United States)

    Madan, I.; Baranov, V. V.; Toda, Y.; Oda, M.; Kurosawa, T.; Kabanov, V. V.; Mertelj, T.; Mihailovic, D.

    2017-11-01

    A systematic temperature-dependent study of the femtosecond optical superconducting (SC) state destruction and recovery in Bi2Sr2CaCu2O8 +δ cuprate superconductor by means of the all-optical polarization-sensitive multipulse spectroscopy is presented. At low temperatures and a partial SC state suppression, an anisotropic SC-gap recovery time scale is suggested by the data. The SC state destruction and recovery dynamics are compared to the recent TR-ARPES-inferred SC-gap dynamics and a qualitative agreement is found. Using a phenomenological response function, the experimental data are also compared to time-dependent Ginzburg-Landau model simulations.

  17. Parameter Estimation

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian

    2011-01-01

    In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  18. Adaptive Linear Parameter Varying Control for Aeroservoelastic Suppression, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Adaptive control offers an opportunity to fulfill aircraft safety objectives though automated vehicle recovery while maintaining performance and stability...

  19. Charge Recombination Suppressed by Destructive Quantum Interference in Heterojunction Materials

    NARCIS (Netherlands)

    Tempelaar, Roel; Koster, L. Jan Anton; Havenith, Remco W. A.; Knoester, Jasper; Jansen, Thomas L. C.

    2016-01-01

    We show that charge recombination in ordered heterojunctions depends sensitively on the degree of coherent delocalization of charges at the donor acceptor interface. Depending on the relative sign of the electron and hole transfer integrals, such delocalization can dramatically suppress

  20. J/Ψ suppression

    International Nuclear Information System (INIS)

    Giubellino, P.; Abreu, M.C.; Alessandro, B.; Alexa, C.; Arnaldi, R.; Astruc, J.; Atayan, M.; Baglin, C.; Baldit, A.; Bedjidian, M.; Bellaiche, F.; Beole, S.; Boldea, V.; Bordalo, P.; Bussiere, A.; Capony, V.; Casagrande, L.; Castor, J.; Chambon, T.; Chaurand, B.; Chevrot, I.; Cheynis, B.; Chiavassa, E.; Cicalo, C.; Comets, M.P.; Constantinescu, S.; Cruz, J.; De Falco, A.; De Marco, N.; Dellacasa, G.; Devaux, A.; Dita, S.; Drapier, O.; Espagnon, B.; Fargeix, J.; Filippov, S.N.; Fleuret, F.; Force, P.; Gallio, M.; Gavrilov, Y.K.; Gerschel, C.; Giubellino, P.; Golubeva, M.B.; Gonin, M.; Grigorian, A.A.; Grossiord, J.Y.; Guber, F.F.; Guichard, A.; Gulkaninan, H.; Hakobyan, R.; Haroutunian, R.; Idzik, M.; Jouan, D.; Karavitcheva, T.L.; Kluberg, L.; Kurepin, A.B.; Le Bornec, Y.; Lourenco, C.; Mac Cormick, M.; Macciotta, P.; Marzari-Chiesa, A.; Masera, M.; Masoni, A.; Mehrabyan, S.; Mourgues, S.; Musso, A.; Ohlsson-Malek, F.; Petiau, P.; Piccotti, A.; Pizzi, J.R.; Prado da Silva, W.L.; Puddu, G.; Quintans, C.; Racca, C.; Ramello, L.; Ramos, S.; Rato-Mendes, P.; Riccati, L.; Romana, A.; Sartori, S.; Saturnini, P.; Scomparin, E.; Serci, S.; Shahoyan, R.; Silva, S.; Soave, C.; Sonderegger, P.; Tarrago, X.; Temnikov, P.; Topilskaya, N.S.; Usai, G.; Vale, C.; Vercellin, E.; Willis, N.

    1999-01-01

    The cross section for J/Ψ production in Pb-Pb interactions at 158 GeV per nucleon is measured at the CERN SPS by the NA50 experiment. The final results from the 1995 run are presented here together with preliminary ones from the high-statistics 1996 run. An anomalous J/Ψ suppression is observed in Pb-Pb collisions as compared to extrapolations of the previous results obtained by the NA38 experiment with proton and lighter ion beams. The results of the two runs are in good agreement. The results from the 1996 run allow the study of the onset of the anomalous suppression within the same set of data, showing evidence of a sharp change of behaviour around a value of neutral transverse energy, as measured by our electromagnetic calorimeter, of about 50 GeV

  1. Multiscale KF Algorithm for Strong Fractional Noise Interference Suppression in Discrete-Time UWB Systems

    Directory of Open Access Journals (Sweden)

    Liyun Su

    2011-01-01

    Full Text Available In order to suppress the interference of the strong fractional noise signal in discrete-time ultrawideband (UWB systems, this paper presents a new UWB multi-scale Kalman filter (KF algorithm for the interference suppression. This approach solves the problem of the narrowband interference (NBI as nonstationary fractional signal in UWB communication, which does not need to estimate any channel parameter. In this paper, the received sampled signal is transformed through multiscale wavelet to obtain a state transition equation and an observation equation based on the stationarity theory of wavelet coefficients in time domain. Then through the Kalman filter method, fractional signal of arbitrary scale is easily figured out. Finally, fractional noise interference is subtracted from the received signal. Performance analysis and computer simulations reveal that this algorithm is effective to reduce the strong fractional noise when the sampling rate is low.

  2. Aperiodic order

    CERN Document Server

    Grimm, Uwe

    2017-01-01

    Quasicrystals are non-periodic solids that were discovered in 1982 by Dan Shechtman, Nobel Prize Laureate in Chemistry 2011. The mathematics that underlies this discovery or that proceeded from it, known as the theory of Aperiodic Order, is the subject of this comprehensive multi-volume series. This second volume begins to develop the theory in more depth. A collection of leading experts, among them Robert V. Moody, cover various aspects of crystallography, generalising appropriately from the classical case to the setting of aperiodically ordered structures. A strong focus is placed upon almost periodicity, a central concept of crystallography that captures the coherent repetition of local motifs or patterns, and its close links to Fourier analysis. The book opens with a foreword by Jeffrey C. Lagarias on the wider mathematical perspective and closes with an epilogue on the emergence of quasicrystals, written by Peter Kramer, one of the founders of the field.

  3. Moose models with vanishing S parameter

    International Nuclear Information System (INIS)

    Casalbuoni, R.; De Curtis, S.; Dominici, D.

    2004-01-01

    In the linear moose framework, which naturally emerges in deconstruction models, we show that there is a unique solution for the vanishing of the S parameter at the lowest order in the weak interactions. We consider an effective gauge theory based on K SU(2) gauge groups, K+1 chiral fields, and electroweak groups SU(2) L and U(1) Y at the ends of the chain of the moose. S vanishes when a link in the moose chain is cut. As a consequence one has to introduce a dynamical nonlocal field connecting the two ends of the moose. Then the model acquires an additional custodial symmetry which protects this result. We examine also the possibility of a strong suppression of S through an exponential behavior of the link couplings as suggested by the Randall Sundrum metric

  4. Multi-objective optimization of piezoelectric circuitry network for mode delocalization and suppression of bladed disk

    Science.gov (United States)

    Yoo, David; Tang, J.

    2017-04-01

    Since weakly-coupled bladed disks are highly sensitive to the presence of uncertainties, they can easily undergo vibration localization. When vibration localization occurs, vibration modes of bladed disk become dramatically different from those under the perfectly periodic condition, and the dynamic response under engine-order excitation is drastically amplified. In previous studies, it is investigated that amplified vibration response can be suppressed by connecting piezoelectric circuitry into individual blades to induce the damped absorber effect, and localized vibration modes can be alleviated by integrating piezoelectric circuitry network. Delocalization of vibration modes and vibration suppression of bladed disk, however, require different optimal set of circuit parameters. In this research, multi-objective optimization approach is developed to enable finding the best circuit parameters, simultaneously achieving both objectives. In this way, the robustness and reliability in bladed disk can be ensured. Gradient-based optimizations are individually developed for mode delocalization and vibration suppression, which are then integrated into multi-objective optimization framework.

  5. Mathematical modeling of continuous and intermittent androgen suppression for the treatment of advanced prostate cancer.

    Science.gov (United States)

    Voth, Alacia M; Alford, John G; Swim, Edward W

    2017-06-01

    Prostate cancer is one of the most prevalent types of cancer among men. It is stimulated by the androgens, or male sexual hormones, which circulate in the blood and diffuse into the tissue where they stimulate the prostate tumor to grow. One of the most important treatments for advanced prostate cancer has become androgen deprivation therapy (ADT). In this paper we present three different models of ADT for prostate cancer: continuous androgen suppression (CAS), intermittent androgen suppression (IAS), and periodic androgen suppression. Currently, many patients in the U.S. receive CAS therapy of ADT, but many undergo a relapse after several years and experience adverse side effects while receiving treatment. Some clinical studies have introduced various IAS regimens in order to delay the time to relapse, and/or to reduce the economic costs and adverse side effects. We will compute and analyze parameter sensitivity analysis for CAS and IAS which may give insight to plan effective data collection in a future clinical trial. Moreover, a periodic model for IAS is used to develop an analytical formulation for relapse times which then provides information about the sensitivity of relapse to the parameters in our models.

  6. Chaos suppression based on adaptive observer for a P-class of chaotic systems

    International Nuclear Information System (INIS)

    Rodriguez, Angel; Leon, Jesus de; Femat, Ricardo

    2007-01-01

    A feedback approach is presented to suppress chaos in a P-class of chaotic system. The approach is based on an adaptive observer; which provides estimated values of both the unmeasured states and the uncertain model parameters. A continuous-time feedback law is taken as suppressing force. The feedback law attains chaos suppression as the observer provides estimated values close to the actual state/parameter values along time. The proposed scheme is robust in the sense that suppression is achieved despite only some states are measured and uncertainties in parameters are compensated. Results are corroborated experimentally by implementation in chaotic circuits

  7. Suppression of anomalous synchronization and nonstationary behavior of neural network under small-world topology

    Science.gov (United States)

    Boaretto, B. R. R.; Budzinski, R. C.; Prado, T. L.; Kurths, J.; Lopes, S. R.

    2018-05-01

    It is known that neural networks under small-world topology can present anomalous synchronization and nonstationary behavior for weak coupling regimes. Here, we propose methods to suppress the anomalous synchronization and also to diminish the nonstationary behavior occurring in weakly coupled neural network under small-world topology. We consider a network of 2000 thermally sensitive identical neurons, based on the model of Hodgkin-Huxley in a small-world topology, with the probability of adding non local connection equal to p = 0 . 001. Based on experimental protocols to suppress anomalous synchronization, as well as nonstationary behavior of the neural network dynamics, we make use of (i) external stimulus (pulsed current); (ii) biologic parameters changing (neuron membrane conductance changes); and (iii) body temperature changes. Quantification analysis to evaluate phase synchronization makes use of the Kuramoto's order parameter, while recurrence quantification analysis, particularly the determinism, computed over the easily accessible mean field of network, the local field potential (LFP), is used to evaluate nonstationary states. We show that the methods proposed can control the anomalous synchronization and nonstationarity occurring for weak coupling parameter without any effect on the individual neuron dynamics, neither in the expected asymptotic synchronized states occurring for large values of the coupling parameter.

  8. How to suppress obsessive thoughts.

    Science.gov (United States)

    Rassin, Eric; Diepstraten, Philip

    2003-01-01

    Thought suppression (i.e. consciously trying to avoid certain thoughts from entering consciousness) has been argued to be an inadequate strategy in case of unwanted intrusions. That is, thought suppression seems to result in more rather than less intrusions. Although this experimental finding has been explained in terms of failing attempts to distract oneself from the target thought, the White Bear Suppression Inventory (WBSI; a scale that measures chronic thought suppression tendencies) does not address the means by which respondents try to suppress unwanted thoughts. To examine which strategies of mental control people use to suppress unwanted thoughts, obsessive-compulsive disorder patients (N=47) completed the WBSI, the Thought Control Questionnaire, and two measures of psychopathology. Results suggest that the crucial mechanism in thought suppression may not be distraction, but self-punishment.

  9. Econometric analysis of fire suppression production functions for large wildland fires

    Science.gov (United States)

    Thomas P. Holmes; David E. Calkin

    2013-01-01

    In this paper, we use operational data collected for large wildland fires to estimate the parameters of economic production functions that relate the rate of fireline construction with the level of fire suppression inputs (handcrews, dozers, engines and helicopters). These parameter estimates are then used to evaluate whether the productivity of fire suppression inputs...

  10. Unihemispheric burst suppression

    Directory of Open Access Journals (Sweden)

    Edward C. Mader Jr.

    2014-08-01

    Full Text Available Burst suppression (BS consists of bursts of high-voltage slow and sharp wave activity alternating with periods of background suppression in the electroencephalogram (EEG. When induced by deep anesthesia or encephalopathy, BS is bihemispheric and is often viewed as a non-epileptic phenomenon. In contrast, unihemispheric BS is rare and its clinical significance is poorly understood. We describe here two cases of unihemispheric BS. The first patient is a 56-year-old woman with a left temporoparietal tumor who presented in convulsive status epilepticus. EEG showed left hemispheric BS after clinical seizure termination with lorazepam and propofol. The second patient is a 39-year-old woman with multiple medical problems and a vague history of seizures. After abdominal surgery, she experienced a convulsive seizure prompting treatment with propofol. Her EEG also showed left hemispheric BS. In both cases, increasing the propofol infusion rate resulted in disappearance of unihemispheric BS and clinical improvement. The prevailing view that typical bihemispheric BS is non-epileptic should not be extrapolated automatically to unihemispheric BS. The fact that unihemispheric BS was associated with clinical seizure and resolved with propofol suggests that, in both cases, an epileptic mechanism was responsible for unihemispheric BS.

  11. Application of Powder Diffraction Methods to the Analysis of Short- and Long-Range Atomic Order in Nanocrystalline Diamond and SiC: The Concept of the Apparent Lattice Parameter (alp)

    Science.gov (United States)

    Palosz, B.; Grzanka, E.; Gierlotka, S.; Stelmakh, S.; Pielaszek, R.; Bismayer, U.; Weber, H.-P.; Palosz, W.

    2003-01-01

    Two methods of the analysis of powder diffraction patterns of diamond and SiC nanocrystals are presented: (a) examination of changes of the lattice parameters with diffraction vector Q ('apparent lattice parameter', alp) which refers to Bragg scattering, and (b), examination of changes of inter-atomic distances based on the analysis of the atomic Pair Distribution Function, PDF. Application of these methods was studied based on the theoretical diffraction patterns computed for models of nanocrystals having (i) a perfect crystal lattice, and (ii), a core-shell structure, i.e. constituting a two-phase system. The models are defined by the lattice parameter of the grain core, thickness of the surface shell, and the magnitude and distribution of the strain field in the shell. X-ray and neutron experimental diffraction data of nanocrystalline SiC and diamond powders of the grain diameter from 4 nm up to micrometers were used. The effects of the internal pressure and strain at the grain surface on the structure are discussed based on the experimentally determined dependence of the alp values on the Q-vector, and changes of the interatomic distances with the grain size determined experimentally by the atomic Pair Distribution Function (PDF) analysis. The experimental results lend a strong support to the concept of a two-phase, core and the surface shell structure of nanocrystalline diamond and SiC.

  12. Suppression of friction by mechanical vibrations.

    Science.gov (United States)

    Capozza, Rosario; Vanossi, Andrea; Vezzani, Alessandro; Zapperi, Stefano

    2009-08-21

    Mechanical vibrations are known to affect frictional sliding and the associated stick-slip patterns causing sometimes a drastic reduction of the friction force. This issue is relevant for applications in nanotribology and to understand earthquake triggering by small dynamic perturbations. We study the dynamics of repulsive particles confined between a horizontally driven top plate and a vertically oscillating bottom plate. Our numerical results show a suppression of the high dissipative stick-slip regime in a well-defined range of frequencies that depends on the vibrating amplitude, the normal applied load, the system inertia and the damping constant. We propose a theoretical explanation of the numerical results and derive a phase diagram indicating the region of parameter space where friction is suppressed. Our results allow to define better strategies for the mechanical control of friction.

  13. Suppression of sympathetic detonation

    Science.gov (United States)

    Foster, J. C., Jr.; Gunger, M. E.; Craig, B. G.; Parsons, G. H.

    1984-08-01

    There are two basic approaches to suppression of sympathetic detonation. Minimizing the shock sensitivity of the explosive to long duration pressure will obviously reduce interround separation distances. However, given that the explosive sensitivity is fixed, then much can be gained through the use of simple barriers placed between the rounds. Researchers devised calculational methods for predicting shock transmission; experimental methods have been developed to characterize explosive shock sensitivity and observe the response of acceptors to barriers. It was shown that both EAK and tritonal can be initiated to detonation with relatively low pressure shocks of long durations. It was also shown that to be an effective barrier between the donor and acceptor, the material must attenuate shock and defect fragments. Future actions will concentrate on refining the design of barriers to minimize weight, volume, and cost.

  14. Tunneling dynamics of Bose—Einstein condensates with higher-order interactions in optical lattice

    Science.gov (United States)

    Tie, Lu; Xue, Ju-Kui

    2011-12-01

    The nonlinear Landau—Zener tunneling and nonlinear Rabi oscillations of Bose—Einstein condensate (BEC) with higher-order atomic interaction between the Bloch bands in an accelerating optical lattice are discussed. Within the two-level model, the tunneling probability of BEC with higher-order atomic interaction between Bloch bands is obtained. We finds that the tunneling rate is closely related to the higher-order atomic interaction. Furthermore, the nonlinear Rabi oscillations of BEC with higher-order atomic interaction between the bands are discussed by imposing a periodic modulation on the level bias. Analytical expressions of the critical higher-order atomic interaction for suppressing/enhancing the Rabi oscillations are obtained. It is shown that the critical value strongly depends on the modulation parameters (i.e., the modulation amplitude and frequency) and the strength of periodic potential.

  15. The development of a decision support system with an interactive clinical user interface for estimating treatment parameters in radiation therapy in order to reduce radiation dose in head and neck patients

    Science.gov (United States)

    Verma, Sneha; Liu, Joseph; Deshpande, Ruchi; DeMarco, John; Liu, Brent J.

    2017-03-01

    The primary goal in radiation therapy is to target the tumor with the maximum possible radiation dose while limiting the radiation exposure of the surrounding healthy tissues. However, in order to achieve an optimized treatment plan, many constraints, such as gender, age, tumor type, location, etc. need to be considered. The location of the malignant tumor with respect to the vital organs is another possible important factor for treatment planning process which can be quantified as a feature making it easier to analyze its effects. Incorporation of such features into the patient's medical history could provide additional knowledge that could lead to better treatment outcomes. To show the value of features such as relative locations of tumors and surrounding organs, the data is first processed in order to calculate the features and formulate a feature matrix. Then these feature are matched with retrospective cases with similar features to provide the clinician with insight on delivered dose in similar cases from past. This process provides a range of doses that can be delivered to the patient while limiting the radiation exposure of surrounding organs based on similar retrospective cases. As the number of patients increase, there will be an increase in computations needed for feature extraction as well as an increase in the workload for the physician to find the perfect dose amount. In order to show how such algorithms can be integrated we designed and developed a system with a streamlined workflow and interface as prototype for the clinician to test and explore. Integration of the tumor location feature with the clinician's experience and training could play a vital role in designing new treatment algorithms and better outcomes. Last year, we presented how multi-institutional data into a decision support system is incorporated. This year the presentation is focused on the interface and demonstration of the working prototype of informatics system.

  16. Order functions and evaluation codes

    DEFF Research Database (Denmark)

    Høholdt, Tom; Pellikaan, Ruud; van Lint, Jack

    1997-01-01

    Based on the notion of an order function we construct and determine the parameters of a class of error-correcting evaluation codes. This class includes the one-point algebraic geometry codes as wella s the generalized Reed-Muller codes and the parameters are detremined without using the heavy...... machinery of algebraic geometry....

  17. Suppressing voltage transients in high voltage power supplies

    International Nuclear Information System (INIS)

    Lickel, K.F.; Stonebank, R.

    1979-01-01

    A high voltage power supply for an X-ray tubes includes voltage adjusting means, a high voltage transformer, switch means connected to make and interrupt the primary current of the transformer, and over-voltage suppression means to suppress the voltage transient produced when the current is switched on. In order to reduce the power losses in the suppression means, an impedance is connected in the transformer primary circuit on operation of the switch means and is subsequently short-circuited by a switch controlled by a timer after a period which is automatically adjusted to the duration of the transient overvoltage. (U.K.)

  18. Surround suppression maps in the cat primary visual cortex

    OpenAIRE

    Vanni, Matthieu P.; Casanova, Christian

    2013-01-01

    In the primary visual cortex and higher-order areas, it is well known that the stimulation of areas surrounding the classical receptive field of a neuron can inhibit its responses. In the primate area middle temporal (MT), this surround suppression was shown to be spatially organized into high and low suppression modules. However, such an organization has not been demonstrated yet in the primary visual cortex. Here, we used optical imaging of intrinsic signals to spatially evaluate surround s...

  19. An Alternative to Thought Suppression?

    Science.gov (United States)

    Boice, Robert

    2012-01-01

    Comments on the original article, "Setting free the bears: Escape from thought suppression," by D. M. Wegner (see record 2011-25622-008). While Wegner supposed that we might have to learn to live with bad thoughts, the present author discusses the use of imagination and guided imagery as an alternative to forced thought suppression.

  20. Bomb parameters

    International Nuclear Information System (INIS)

    Kerr, George D.; Young, Rebert W.; Cullings, Harry M.; Christry, Robert F.

    2005-01-01

    The reconstruction of neutron and gamma-ray doses at Hiroshima and Nagasaki begins with a determination of the parameters describing the explosion. The calculations of the air transported radiation fields and survivor doses from the Hiroshima and Nagasaki bombs require knowledge of a variety of parameters related to the explosions. These various parameters include the heading of the bomber when the bomb was released, the epicenters of the explosions, the bomb yields, and the tilt of the bombs at time of explosion. The epicenter of a bomb is the explosion point in air that is specified in terms of a burst height and a hypocenter (or the point on the ground directly below the epicenter of the explosion). The current reassessment refines the energy yield and burst height for the Hiroshima bomb, as well as the locations of the Hiroshima and Nagasaki hypocenters on the modern city maps used in the analysis of the activation data for neutrons and TLD data for gamma rays. (J.P.N.)

  1. Seiberg-Witten maps to all orders

    International Nuclear Information System (INIS)

    Uelker, Kayhan; Yapiskan, Baris

    2008-01-01

    All order Seiberg-Witten maps of gauge parameter, gauge field, and matter fields are given as a closed recursive formula. These maps are obtained by analyzing the order by order solutions of the gauge consistency and equivalence conditions as well as by directly solving Seiberg-Witten differential equations. The explicit third order non-Abelian and fourth order Abelian Seiberg-Witten maps of gauge parameter and gauge field are also presented.

  2. Neural adaptive control for vibration suppression in composite fin-tip of aircraft.

    Science.gov (United States)

    Suresh, S; Kannan, N; Sundararajan, N; Saratchandran, P

    2008-06-01

    In this paper, we present a neural adaptive control scheme for active vibration suppression of a composite aircraft fin tip. The mathematical model of a composite aircraft fin tip is derived using the finite element approach. The finite element model is updated experimentally to reflect the natural frequencies and mode shapes very accurately. Piezo-electric actuators and sensors are placed at optimal locations such that the vibration suppression is a maximum. Model-reference direct adaptive neural network control scheme is proposed to force the vibration level within the minimum acceptable limit. In this scheme, Gaussian neural network with linear filters is used to approximate the inverse dynamics of the system and the parameters of the neural controller are estimated using Lyapunov based update law. In order to reduce the computational burden, which is critical for real-time applications, the number of hidden neurons is also estimated in the proposed scheme. The global asymptotic stability of the overall system is ensured using the principles of Lyapunov approach. Simulation studies are carried-out using sinusoidal force functions of varying frequency. Experimental results show that the proposed neural adaptive control scheme is capable of providing significant vibration suppression in the multiple bending modes of interest. The performance of the proposed scheme is better than the H(infinity) control scheme.

  3. Experimental investigation on the behaviour of pressure suppression containment systems by the SOPRE-1 facility

    International Nuclear Information System (INIS)

    Cerullo, N.; Delli Gatti, A.; Marinelli, M.; Mazzini, M.; Mazzoni, A.; Sbrana, A.; Todisco, P.

    1977-01-01

    The SOPRE-1 test facility is an integral model (scale 1:13) of a MARK II pressure suppression containment system. It was set up at the University of Pisa in order to study the pressure-temperature transient in pressure suppression containment systems during LOCAs. Knowledge of this transient is necessary to perform a correct structural analysis of reactor containment. The containment system behaviour is studied by changing the principal parameters which affect the transient (blow-down mass and energy release, suppression pool water temperature, vent pipe number and submergence heat transfer coefficients). The first series of tests involved: A) 13 tests with break area of 1.8 cm 2 , B) 8 tests with break area of 20.0 cm 2 . The following experimental conditions were changed: - position of the simulated break (from liquid or steam zone), - water pressure (20-85 Kgsub(p)/cm 2 ) and mass (45-70Kg) in the vessel model. Tests A): the CONTEMPT codes correctly forecast the pressure-temperature history, both in dry- and in wet-well. Tests B): the experimental runs have shown that increasing of blow-down flowrate produces dry-well pressure spatial differences and anomalous vent pipe behaviour. This results in damped oscillations of dry- and wet-well pressure, probably due to alterbating air bubble over-expansion and collapse, and in vent pipe opening and reclosing. (Auth.)

  4. A cortical locus for anisotropic overlay suppression of stimuli presented at fixation.

    Science.gov (United States)

    Hansen, Bruce C; Richard, Bruno; Andres, Kristin; Johnson, Aaron P; Thompson, Benjamin; Essock, Edward A

    2015-01-01

    Human contrast sensitivity for narrowband Gabor targets is suppressed when superimposed on narrowband masks of the same spatial frequency and orientation (referred to as overlay suppression), with suppression being broadly tuned to orientation and spatial frequency. Numerous behavioral and neurophysiological experiments have suggested that overlay suppression originates from the initial lateral geniculate nucleus (LGN) inputs to V1, which is consistent with the broad tuning typically reported for overlay suppression. However, recent reports have shown narrowly tuned anisotropic overlay suppression when narrowband targets are masked by broadband noise. Consequently, researchers have argued for an additional form of overlay suppression that involves cortical contrast gain control processes. The current study sought to further explore this notion behaviorally using narrowband and broadband masks, along with a computational neural simulation of the hypothesized underlying gain control processes in cortex. Additionally, we employed transcranial direct current stimulation (tDCS) in order to test whether cortical processes are involved in driving narrowly tuned anisotropic suppression. The behavioral results yielded anisotropic overlay suppression for both broadband and narrowband masks and could be replicated with our computational neural simulation of anisotropic gain control. Further, the anisotropic form of overlay suppression could be directly modulated by tDCS, which would not be expected if the suppression was primarily subcortical in origin. Altogether, the results of the current study provide further evidence in support of an additional overlay suppression process that originates in cortex and show that this form of suppression is also observable with narrowband masks.

  5. Parameter setting and input reduction

    NARCIS (Netherlands)

    Evers, A.; van Kampen, N.J.|info:eu-repo/dai/nl/126439737

    2008-01-01

    The language acquisition procedure identifies certain properties of the target grammar before others. The evidence from the input is processed in a stepwise order. Section 1 equates that order and its typical effects with an order of parameter setting. The question is how the acquisition procedure

  6. Feasibility of driving perpendicular rotation in core plasma by off-axis neutral beam injection to suppress microturbulence

    International Nuclear Information System (INIS)

    Hassam, A.B.

    1993-01-01

    Various aspects pertaining to driving perpendicular rotation in core plasma with neutral beam injection to suppress microturbulence are discussed. The assessment is based on the premise that a critical perpendicular velocity shear of order C s /L s is required to effect significant turbulence suppression. The equilibrium of a tokamak plasma rotating poloidally at such high frequencies is examined from drift-kinetic theory. It is shown that a substantial fraction of trapped particles is now detrapped. The calculation also shows that viscous damping from magnetic pumping falls off as the square of the poloidal speed. This reduction in viscous damping makes more efficacious the driving of large poloidal flows from off-axis neutral beam injection. The feasibility of exceeding the critical velocity shear is assessed, both for present day tokamaks as well as for reactor parameters. The magnetohydrodynamic stability of tokamak plasma rotating at high speeds with respect to Kelvin-Helmholtz and interchange modes is assessed

  7. Order Aggressiveness and Order Book Dynamics

    OpenAIRE

    Anthony D. Hall; Nikolaus Hautsch

    2004-01-01

    In this paper, we study the determinants of order aggressiveness and traders' order submission strategy in an open limit order book market. Using order book data from the Australian Stock Exchange, we model traders' aggressiveness in market trading, limit order trading as well as in order cancellations on both sides of the market using a six-dimensional autoregressive intensity model. The information revealed by the open order book plays an important role in explaining the degree of order agg...

  8. A model for explaining fusion suppression using classical trajectory method

    Directory of Open Access Journals (Sweden)

    Phookan C. K.

    2015-01-01

    Full Text Available We adopt a semi-classical approach for explanation of projectile breakup and above barrier fusion suppression for the reactions 6Li+152Sm and 6Li+144Sm. The cut-off impact parameter for fusion is determined by employing quantum mechanical ideas. Within this cut-off impact parameter for fusion, the fraction of projectiles undergoing breakup is determined using the method of classical trajectory in two-dimensions. For obtaining the initial conditions of the equations of motion, a simplified model of the 6Li nucleus has been proposed. We introduce a simple formula for explanation of fusion suppression. We find excellent agreement between the experimental and calculated fusion cross section. A slight modification of the above formula for fusion suppression is also proposed for a three-dimensional model.

  9. Menstrual suppression in the adolescent.

    Science.gov (United States)

    Kantartzis, Kelly L; Sucato, Gina S

    2013-06-01

    Menstrual suppression, the use of contraceptive methods to eliminate or decrease the frequency of menses, is often prescribed for adolescents to treat menstrual disorders or to accommodate patient preference. For young women using hormonal contraceptives, there is no medical indication for menstruation to occur monthly, and various hormonal contraceptives can be used to decrease the frequency of menstruation with different side effect profiles and rates of amenorrhea. This article reviews the different modalities for menstrual suppression, common conditions in adolescents which may improve with menstrual suppression, and strategies for managing common side effects. Copyright © 2013 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  10. Fragile Thermodynamic Order

    International Nuclear Information System (INIS)

    Bernhoeft, N.; Lander, G.H.; Colineau, E.

    2003-01-01

    An asymmetric shift in the position of the magnetic Bragg peak with respect to the fiducial lattice has been observed by resonant X-ray scattering in a diverse series of antiferromagnetic compounds. This apparent violation of Bragg's law is interpreted in terms of a dynamically phased order parameter. We demonstrate the use of this effect as a novel probe of fragile or dynamic thermodynamic order in strongly correlated electronic systems. In particular, fresh light is shed on the paradoxical situation encountered in URu 2 Si 2 where the measured entropy gain on passing through T Neel is incompatible with the ground state moment estimated by neutron diffraction. The intrinsic space-time averaging of the probe used to characterise the thermodynamic macroscopic state may play a crucial and previously neglected role. In turn, this suggests the further use of resonant X-ray scattering in investigations of systems dominated by quantum fluctuations. (author)

  11. Compton suppression gamma ray spectrometry

    International Nuclear Information System (INIS)

    Landsberger, S.; Iskander, F.Y.; Niset, M.; Heydorn, K.

    2002-01-01

    In the past decade there have been many studies to use Compton suppression methods in routine neutron activation analysis as well as in the traditional role of low level gamma ray counting of environmental samples. On a separate path there have been many new PC based software packages that have been developed to enhance photopeak fitting. Although the newer PC based algorithms have had significant improvements, they still suffer from being effectively used in weak gamma ray lines in natural samples or in neutron activated samples that have very high Compton backgrounds. We have completed a series of experiments to show the usefulness of Compton suppression. As well we have shown the pitfalls when using Compton suppression methods for high counting deadtimes as in the case of neutron activated samples. We have also investigated if counting statistics are the same both suppressed and normal modes. Results are presented in four separate experiments. (author)

  12. Thyroid suppression test with dextrothyroxine

    International Nuclear Information System (INIS)

    Rosenthal, D.; Fridman, J.; Ribeiro, H.B.

    1978-01-01

    The classic thyroid suppression test with triiodothyronine (l-T 3 ) has been shown to be efficient as an auxiliary method in the diagnosis of thyroid diseases, but should not be performed on elderly patients or on those with heart disease or a tendency to tachycardia. Since these subjects seem able to support a short period of dextro-thyronine (d-T 4 ) feeding, we compared the effect of d-T 4 and l-T 3 on the 24 hours thyroid uptake in euthyroid and hyperthyroid subjects. After basal radio-iodine uptake determination, 99 patients without hyperthyroidism and 27 with Graves' disease were randomly divided in 2 groups; one received 100μg of l-T 3 per day and the other 4 mg of d-T 4 per day, both groups being treated for a period of 10 days. At the end of this suppression period the 24 hours radio-iodine uptake was measured again and the percentual suppression index (S.I.) calculated. Since the comparison of the two groups showed no difference between the suppressive effect of l-T 3 and d-T 4 in euthyroid subjects, while dextro-thyronine, as levo-triiodothyronine, did not suppress the 24 hours uptake of hyperthyroid patients, l-T 3 or d-T 4 can be used interchangeably to test thyroid suppressibility. In the euthyroid subjects the normal range for the post-suppression uptake was 0-17.1% and for the suppression index 54,7.100% [pt

  13. In vivo Treg suppression assays.

    Science.gov (United States)

    Workman, Creg J; Collison, Lauren W; Bettini, Maria; Pillai, Meenu R; Rehg, Jerold E; Vignali, Dario A A

    2011-01-01

    To fully examine the functionality of a regulatory T cell (T(reg)) population, one needs to assess their ability to suppress in a variety of in vivo models. We describe five in vivo models that examine the suppressive capacity of T(regs) upon different target cell types. The advantages and disadvantages of each model including resources, time, and technical expertise required to execute each model are also described.

  14. In Vivo Treg Suppression Assays

    OpenAIRE

    Workman, Creg J.; Collison, Lauren W.; Bettini, Maria; Pillai, Meenu R.; Rehg, Jerold E.; Vignali, Dario A.A.

    2011-01-01

    To fully examine the functionality of a regulatory T cell (Treg) population, one needs to assess their ability to suppress in a variety of in vivo models. We describe five in vivo models that examine the suppressive capacity of Tregs upon different target cell types. The advantages and disadvantages of each model includ ing resources, time, and technical expertise required to execute each model are also described.

  15. Supergranular Parameters

    Science.gov (United States)

    Udayashankar, Paniveni

    2016-07-01

    I study the complexity of supergranular cells using intensity patterns from Kodaikanal solar observatory. The chaotic and turbulent aspect of the solar supergranulation can be studied by examining the interrelationships amongst the parameters characterizing supergranular cells namely size, horizontal flow field, lifetime and physical dimensions of the cells and the fractal dimension deduced from the size data. The findings are supportive of Kolmogorov's theory of turbulence. The Data consists of visually identified supergranular cells, from which a fractal dimension 'D' for supergranulation is obtained according to the relation P α AD/2 where 'A' is the area and 'P' is the perimeter of the supergranular cells. I find a fractal dimension close to about 1.3 which is consistent with that for isobars and suggests a possible turbulent origin. The cell circularity shows a dependence on the perimeter with a peak around (1.1-1.2) x 105 m. The findings are supportive of Kolmogorov's theory of turbulence.

  16. Burst Suppression for ICP Control.

    Science.gov (United States)

    Zeiler, Frederick A; Akoth, Eva; Gillman, Lawrence M; West, Michael

    2017-02-01

    The goal of our study was to perform a systematic review of the literature to determine the effect that burst suppression has on intracranial pressure (ICP) control. All articles from MEDLINE, BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library, the International Clinical Trials Registry Platform (inception to January 2015), reference lists of relevant articles, and gray literature were searched. The strength of evidence was adjudicated using both the Oxford and the Grading of Recommendation Assessment Development and Education (GRADE) methodology. Seven articles were considered for review. A total of 108 patients were studied, all receiving burst suppression therapy. Two studies failed to document a decrease in ICP with burst suppression therapy. There were reports of severe hypotension and increased infection rates with barbiturate-based therapy. Etomidate-based suppressive therapy was linked to severe renal dysfunction. There currently exists both Oxford level 2b and GRADE C evidence to support that achieving burst suppression reduces ICP, and also has no effect on ICP, in severe traumatic brain injury. The literature suggests burst suppression therapy may be useful for ICP reduction in certain cases, although these situations are currently unclear. In addition, the impact on patient functional outcome is unclear. Further prospective study is warranted.

  17. Neural Correlates of Direct and Indirect Suppression of Autobiographical Memories.

    Science.gov (United States)

    Noreen, Saima; O'Connor, Akira R; MacLeod, Malcolm D

    2016-01-01

    Research indicates that there are two possible mechanisms by which particular target memories can be intentionally forgotten. Direct suppression, which involves the suppression of the unwanted memory directly, and is dependent on a fronto-hippocampal modulatory process, and, memory substitution, which includes directing one's attention to an alternative memory in order to prevent the unwanted memory from coming to mind, and involves engaging the caudal prefrontal cortex (cPFC) and the mid-ventrolateral prefrontal cortex (VLPFC) regions. Research to date, however, has investigated the neural basis of memory suppression of relatively simple information. The aim of the current study was to use fMRI to identify the neural mechanisms associated with the suppression of autobiographical memories. In the present study, 22 participants generated memories in response to a series of cue words. In a second session, participants learnt these cue-memory pairings, and were subsequently presented with a cue word and asked either to recall (think) or to suppress (no-think) the associated memory, or to think of an alternative memory in order to suppress the original memory (memory-substitution). Our findings demonstrated successful forgetting effects in the no-think and memory substitution conditions. Although we found no activation in the dorsolateral prefrontal cortex, there was reduced hippocampal activation during direct suppression. In the memory substitution condition, however, we failed to find increased activation in the cPFC and VLPFC regions. Our findings suggest that the suppression of autobiographical memories may rely on different neural mechanisms to those established for other types of material in memory.

  18. Neural Correlates of Direct and Indirect Suppression of Autobiographical Memories

    Directory of Open Access Journals (Sweden)

    Saima eNoreen

    2016-03-01

    Full Text Available Research indicates that there are two possible mechanisms by which particular target memories can be intentionally forgotten. Direct suppression, which involves the suppression of the unwanted memory directly, and is dependent on a fronto-hippocampal modulatory process, and, memory substitution, which includes directing one's attention to an alternative memory in order to prevent the unwanted memory from coming to mind, and involves engaging the caudal prefrontal cortex (cPFC and the mid-ventrolateral prefrontal cortex (VLPFC regions. Research to date, however, has investigated the neural basis of memory suppression of relatively simple information. The aim of the current study was to use fMRI to identify the neural mechanisms associated with the suppression of autobiographical memories. In the present study, 22 participants generated memories in response to a series of cue words. In a second session, participants learnt these cue-memory pairings, and were subsequently presented with a cue word and asked either to recall (think or to suppress (no-think the associated memory, or to think of an alternative memory in order to suppress the original memory (memory-substitution. Our findings demonstrated successful forgetting effects in the no-think and memory substitution conditions. Although we found no activation in the dorsolateral prefrontal cortex there was reduced hippocampal activation during direct suppression. In the memory substitution condition, however, we failed to find increased activation in the cPFC and VLPFC regions. Our findings suggest that the suppression of autobiographical memories may rely on different neural mechanisms to those established for other types of material in memory.

  19. Surround Suppression Maps in the Cat Primary Visual Cortex

    Directory of Open Access Journals (Sweden)

    Matthieu P Vanni

    2013-04-01

    Full Text Available In the primary visual cortex and higher-order areas, it is well known that the stimulation of areas surrounding the classical receptive field of a neuron can inhibit its responses. In the primate area MT, this surround suppression was shown to be spatially organized into high and low suppression modules. However, such an organization hasn’t been demonstrated yet in the primary visual cortex. Here, we used optical imaging of intrinsic signals to spatially evaluate surround suppression in the cat visual cortex. The magnitude of the response was measured in areas 17 and 18 for stimuli with different diameters, presented at different eccentricities. Delimited regions of the cortex were revealed by circumscribed stimulations of the visual field (cortical response field. Increasing the stimulus diameter increased the spread of cortical activation. In the cortical response field, the optimal stimulation diameter and the level of suppression were evaluated. Most pixels (3/4 exhibited surround suppression profiles. The optimal diameter, corresponding to a population of receptive fields, was smaller in area 17 (22 deg. than in area 18 (36 deg. in accordance with electrophysiological data. No difference in the suppression strength was observed between both areas (A17: 25%, A18: 21%. Further analysis of our data revealed the presence of surround modulation maps, organized in low and high suppression domains. We also developed a statistical method to confirm the existence of this cortical map and its neuronal origin. The organization for center/surround suppression observed here at the level of the primary visual cortex is similar to those found in higher order areas in primates (e.g. area MT and could represent a strategy to optimize figure ground discrimination.

  20. Neural Correlates of Direct and Indirect Suppression of Autobiographical Memories

    Science.gov (United States)

    Noreen, Saima; O’Connor, Akira R.; MacLeod, Malcolm D.

    2016-01-01

    Research indicates that there are two possible mechanisms by which particular target memories can be intentionally forgotten. Direct suppression, which involves the suppression of the unwanted memory directly, and is dependent on a fronto-hippocampal modulatory process, and, memory substitution, which includes directing one’s attention to an alternative memory in order to prevent the unwanted memory from coming to mind, and involves engaging the caudal prefrontal cortex (cPFC) and the mid-ventrolateral prefrontal cortex (VLPFC) regions. Research to date, however, has investigated the neural basis of memory suppression of relatively simple information. The aim of the current study was to use fMRI to identify the neural mechanisms associated with the suppression of autobiographical memories. In the present study, 22 participants generated memories in response to a series of cue words. In a second session, participants learnt these cue-memory pairings, and were subsequently presented with a cue word and asked either to recall (think) or to suppress (no-think) the associated memory, or to think of an alternative memory in order to suppress the original memory (memory-substitution). Our findings demonstrated successful forgetting effects in the no-think and memory substitution conditions. Although we found no activation in the dorsolateral prefrontal cortex, there was reduced hippocampal activation during direct suppression. In the memory substitution condition, however, we failed to find increased activation in the cPFC and VLPFC regions. Our findings suggest that the suppression of autobiographical memories may rely on different neural mechanisms to those established for other types of material in memory. PMID:27047412

  1. Experimental investigation on the behavior of pressure suppression containment systems by the SOPRE-1 facility

    International Nuclear Information System (INIS)

    Cerullo, N.; Delli Gatti, A.; Marinelli, M.; Mazzini, M.; Mazzoni, A.; Sbrana, A.; Todisco, P.

    1977-01-01

    The SOPRE-1 test facility is an integral model (scale 1:13) of a MARK II pressure suppression containment system. It was set up at the University of Pisa in order to study the pressure-temperature transient in pressure suppression containment systems during LOCAs. Knowledge of this transient is necessary to perform a correct structural analysis of reactor containment. The containment system behavior is studied by changing the principal parameters which affect the transient (blow-down mass and energy release, suppression pool water temperature, vent pipe number and submergence, heat transfer coefficients). The first series of tests involved: A) 13 tests with break area of 1.8 cm 2 , B) 8 tests with break area of 20.0 cm 2 . The following experimental conditions were changed: position of the simulated break (from liquid or steam zone), water pressure (20-85 Kg/cm 2 ) and mass (45-70 Kg) in the vessel model. Tests A): the CONTEMPT codes correctly forecast the pressure-temperature history, both in dry- and in wet-well. Tests B): the experimental runs have shown that increasing of blow-down flowrate produces dry-well pressure spatial differences and anomalous vent pipe behavior. This results in damped oscillations of dry- and wet-well pressure, probably due to alternating air bubble over-expansion and collapse, and in vent pipe opening and reclosing. Dry-well pressure maxima at the end of blow-down are greater than those forecasted by currently applied codes: these codes use an homogeneous model, and do not take into account the above mentioned dynamic phenomena. In some tests other interesting phenomena were observed, such as some local pressure peaks in the suppression pool greater than dry-well pessure maxima at the end of blow-down. At present, all these phenomena are under study; they could be important for the structural analysis of containment systems

  2. CELSS engineering parameters

    Science.gov (United States)

    Drysdale, Alan; Sager, John; Wheeler, Ray; Fortson, Russ; Chetirkin, Peter

    1993-01-01

    The most important Controlled Ecological Life Support System (CELSS) engineering parameters are, in order of decreasing importance, manpower, mass, and energy. The plant component is a significant contributor to the total system equivalent mass. In this report, a generic plant component is described and the relative equivalent mass and productivity are derived for a number of instances taken from the KSC CELSS Breadboard Project data and literature. Typical specific productivities (edible biomass produced over 10 years divided by system equivalent mass) for closed systems are of the order of 0.2.

  3. Theoretical studies on the free-blowing process of the vent pipes in the pressure suppression system

    International Nuclear Information System (INIS)

    Aust, E.

    1979-01-01

    This report deals with the free-blowing period of the vent pipes in a pressure suppression system, treating especially the analytical simulation of this period. In order to do this the equations presently laid down for use in the computer codes and describing the free-blowing process are presented and their essential model simplifications are worked out. Subsequently, for the simple system of a U-tube filled with water, the fundamental mechanism of the free-blowing process is studied and the results to be transferred from it to the pressure suppression system are discussed. Based on them there are performed calculations with the individual free-blowing models using plant-related parameters as input data, in order to verify in a benchmark comparison the information and the results of calculation of the individual model concepts in relation to one another. Finally the validity of the individual model set-ups and the quality of their predictions are checked by means of experimental results from the pressure suppression experiments on the PSS test stand. (orig.) [de

  4. Simultaneous Suppression of IMD3 and IMD5 in Space TWT by IMD3 and 2HD Signal Injection

    Directory of Open Access Journals (Sweden)

    Dongming Zhao

    2017-01-01

    Full Text Available This paper presents a signal injection technology showing significant reductions in both 3rd-order and 5th-order intermodulation distortions (IMD3 and IMD5 in space traveling wave tube (STWT. By applying the IMD3 to the IMD5 ratio (TFR as measures of location, the simultaneous suppressions of IMD3 and IMD5 in TWT are achieved by second harmonic distortion (2HD and IMD3 injection. According to the research on theoretical analysis and computer simulation, the optimum amplitude and phase parameters of the injected signal for maximum simultaneous suppressions are obtained. Then an experiment system is established based on vector network analyzer, optimum TFR are 2.1 dB and 12.5 dB, respectively, by second harmonic and IM3 injection, and the output powers of IMD3 and IMD5 were decreased. TFR with IMD3 injection is smaller than that with second harmonic injection in STWT, and the experiment system is more straightforward and easy to operate. Thus, the IMD3 injection performs better than that of second harmonic injection to suppress IMD5s for the narrow-band STWT.

  5. Suppression through acoustics

    Science.gov (United States)

    Beck, Kevin D.; Short, Kenneth R.; VanMeenen, Kirsten M.; Servatius, Richard J.

    2006-05-01

    This paper reviews research conducted by our laboratory exploring the possible use of acoustical stimuli as a tool for influencing behavior. Over the course of several programs, different types of acoustic stimuli have been evaluated for their effectiveness in disrupting targeting, balance, and high-order cognitive processes in both humans and animals. Escape responses are of particular use in this regard. An escape response serves not only as an objective measure of aversion, but as a potential substitute for ongoing behavior. We have also assessed whether the level of performance changes if the individual does not perform an escape response. In general these studies have both suggested certain types of sounds are more aversive or distracting than others. Although the laboratory development of additional stimuli needs to continue, we are taking the next step by testing some of the more effective stimuli in more applied experimental scenarios including those involving group dynamics.

  6. Physiological parameters

    International Nuclear Information System (INIS)

    Natera, E.S.

    1998-01-01

    The physiological characteristics of man depend on the intake, metabolism and excretion of stable elements from food, water, and air. The physiological behavior of natural radionuclides and radionuclides from nuclear weapons testing and from the utilization of nuclear energy is believed to follow the pattern of stable elements. Hence information on the normal physiological processes occurring in the human body plays an important role in the assessment of the radiation dose received by man. Two important physiological parameters needed for internal dose determination are the pulmonary function and the water balance. In the Coordinated Research Programme on the characterization of Asian population, five participants submitted data on these physiological characteristics - China, India, Japan, Philippines and Viet Nam. During the CRP, data on other pertinent characteristics such as physical and dietary were simultaneously being collected. Hence, the information on the physiological characteristics alone, coming from the five participants were not complete and are probably not sufficient to establish standard values for the Reference Asian Man. Nonetheless, the data collected is a valuable contribution to this research programme

  7. Vibration phenomena in large scale pressure suppression tests

    International Nuclear Information System (INIS)

    Aust, E.; Boettcher, G.; Kolb, M.; Sattler, P.; Vollbrandt, J.

    1982-01-01

    Structure und fluid vibration phenomena (acceleration, strain; pressure, level) were observed during blow-down experiments simulating a LOCA in the GKSS full scale multivent pressure suppression test facility. The paper describes first the source related excitations during the two regimes of condensation oscillation and of chugging, and deals then with the response vibrations of the facility's wetwell. Modal analyses of the wetwell were run using excitation by hammer and by shaker in order to separate phenomena that are particular to the GKSS facility from more general ones, i.e. phenomena specific to the fluid related parameters of blowdown and to the geometry of the vent pipes only. The lowest periodicities at about 12 and 16 Hz stem from the vent acoustics. A frequency of about 36 to 38 Hz prominent during chugging seems to result from the lowest local models of two of the wetwell's walls when coupled by the wetwell pool. Further peaks found during blowdown in the spectra of signals at higher frequencies correspond to global vibration modes of the wetwell. (orig.)

  8. Self-assembled fluids with order-parameter- dependent mobility ...

    Indian Academy of Sciences (India)

    C Domb, J L Lebowitz (Academic Press, New York, 1994) vol. 16; Phys. Rev. Lett. 65, 1116 (1990). [3] G H Fredrickson and F S Bates, Annu. Rev. Phys. Chem. 41, 525 (1990). [4] A J Bray, Adv. Phys. 43, 357 (1994). [5] J S Langer, M Bar-on and H D Miller, Phys. Rev. A11, 1417 (1975). K Kitahara and M Imada, Suppl. Prog.

  9. Self-assembled fluids with order-parameter- dependent mobility ...

    Indian Academy of Sciences (India)

    high-temperature phase, it is well-established that in most systems the standard scaling exists [4]. By standard scaling, it is meant that, the structure factor. S(k, t) = Ldg(kL), where g(kL) is the ... quenches [5,14] and accounting for the effects of external fields such as gravity [6]. Simulational calculations have been done on ...

  10. Parameters of the lowest order chiral Lagrangian from fermion eigenvalues

    International Nuclear Information System (INIS)

    DeGrand, T.; Schaefer, S.

    2007-08-01

    Recent advances in Random Matrix Theory enable one to determine the pseudoscalar decay constant from the response of eigenmodes of quenched fermions to an imaginary isospin chemical potential. We perform a pilot test of this idea, from simulations with two flavors of dynamical overlap fermions. (orig.)

  11. Compost made of organic wastes suppresses fusariosis

    Science.gov (United States)

    Kuryntseva, Polina; Galitskaya, Polina; Biktasheva, Liliya; Selivanovkaya, Svetlana

    2017-04-01

    Fungal plant diseases cause dramatic yield losses worldwide. Usually, pesticides are used for soil sanitation, and it results in practically pest-free soils, although pesticides cause a biological vacuum, which present many horticultural disadvantages. Suppressive composts, which possess both fertilizing properties for plants and inhibiting properties for plant pathogens, represent an effective and environmentally friendly alternative to conventional pesticides. In this study, composts obtained from agricultural organic wastes were applied to suppress Fusarium oxysporum of tomato plants in model experiments. Composts were made of mixtures of the widespread organic wastes sampled in Tatarstan (Russia): straw (SW), corn wastes (CW), chicken manure (ChM), cattle manure (CM) and swine manure (SM). 11 two- and three-component mixtures were prepared to obtain the optimal carbon-nitrogen, moisture and pH balances, and composted for 210 days. It was found that the thermophilic phase of composting in all the mixtures lasted from 2 to 35 days, and was characterized by significant fluctuations in temperature, i.e. from 27°C to 59°C. In the initial mixtures, the dissolved organic carbon (DOC) content was between 10 and 62 mg kg-1; it fell significantly on day 13, and then continuously decreased up to day 102, and subsequently remained low. For all the mixtures, maximal respiration activity was observed in the beginning of composting (231.9 mg CO2-C g-1 day-1). After 23 days, this parameter decreased significantly, and fluctuations subsided. The phytotoxicity of the initial compost mixtures varied from 18% (SW+SM) to 100% (CW+ChM+SM, CW+ChM); however, the trends in the dynamics were similar. After 120 days of composting, 5 of 11 samples were not phytotoxic. After 120 days of composting, each mixture was divided into two parts; one was inoculated with a biopreparation consisting of four microbial strains (Trichoderma asperellum, Pseudomonas putida, Pseudomonas fluorescens and

  12. Bone-suppressed radiography using machine learning

    International Nuclear Information System (INIS)

    Park, Jun Beom; Kim, Dae Cheon; Kim, Ho Kyung

    2016-01-01

    The single-shot dual-energy imaging suffers from reduced contrast-to-noise ratio performance due to poor spectral separation. Tomosynthesis requires more complex motion equipment and may require higher patient dose. An alternative tissue-specific imaging technique was introduced. This alternative technique usually possesses a filter to generate bone-only images for given digital radiographs. Therefore, it provides soft-tissue-enhanced images from the subtraction of given radiographs and filtered bone-only images. Only bone-suppressed imaging capability is a limitation of the method. The filter can be obtained from a machine-learning algorithm, e.g. artificial neural network (ANN), with the dual-energy bone-only images (called 'teaching' images). We suspect the robustness of the filter may be dependent upon the number of teaching images and the number of patients from whose radiographs we obtain the teaching images. In this study, we design an ANN to obtain a bone-extracting filter from a radiograph, and investigate the filter properties with respect to various ANN parameters. Preliminary results are summarized in Fig. 3. We extracted 5,000 subregions in a 21x21 pixel format from the lung region in the bone-enhanced dual-energy image and we used them for teaching images during training the ANN. The resultant bone-enhanced image from the ANN nonlinear filter is shown in Fig. 3 (a). From the weighted logarithmic subtraction between Fig. 2 (a) and Fig. 3 (a), we could obtain the bone-suppressed image as shown in Fig. 3 (b). The quality of the bone-suppressed image is comparable to the ground truth Fig. 2 (c).

  13. Beyond viral suppression of HIV

    DEFF Research Database (Denmark)

    Lazarus, Jeffrey V.; Safreed-Harmon, Kelly; Barton, Simon E

    2016-01-01

    BACKGROUND: In 2016, the World Health Organization (WHO) adopted a new Global Health Sector Strategy on HIV for 2016-2021. It establishes 15 ambitious targets, including the '90-90-90' target calling on health systems to reduce under-diagnosis of HIV, treat a greater number of those diagnosed......, and ensure that those being treated achieve viral suppression. DISCUSSION: The WHO strategy calls for person-centered chronic care for people living with HIV (PLHIV), implicitly acknowledging that viral suppression is not the ultimate goal of treatment. However, it stops short of providing an explicit target...... for health-related quality of life. It thus fails to take into account the needs of PLHIV who have achieved viral suppression but still must contend with other intense challenges such as serious non-communicable diseases, depression, anxiety, financial stress, and experiences of or apprehension about HIV...

  14. Resonance suppression from color reconnection

    Science.gov (United States)

    Acconcia, R.; Chinellato, D. D.; de Souza, R. Derradi; Takahashi, J.; Torrieri, G.; Markert, C.

    2018-02-01

    We present studies that show how multi-parton interaction and color reconnection affect the hadro-chemistry in proton-proton (pp) collisions with special focus on the production of resonances using the pythia8 event generator. We find that color reconnection suppresses the relative production of meson resonances such as ρ0 and K* , providing an alternative explanation for the K*/K decrease observed in proton-proton collisions as a function of multiplicity by the ALICE collaboration. Detailed studies of the underlying mechanism causing meson resonance suppression indicate that color reconnection leads to shorter, less energetic strings whose fragmentation is less likely to produce more massive hadrons for a given quark content, therefore reducing ratios such as K*/K and ρ0/π in high-multiplicity pp collisions. In addition, we have also studied the effects of allowing string junctions to form and found that these may also contribute to resonance suppression.

  15. Teaching to suppress Polglish processes

    OpenAIRE

    Dziubalska-Kołaczyk, Katarzyna; Balas, Anna; Schwartz, Geoffrey; Rojczyk, Arkadiusz; Wrembel, Magdalena

    2015-01-01

    Advanced second language (henceforth L2) learners in a formal setting can suppress many first language (henceforth L1) processes in L2 pronunciation when provided with sufficient exposure to L2 and meta competence (see Sect. 4 for a definition of this term). This paper shows how imitation in L2 teaching can be enhanced on the basis of current phonetic research and how complex allophonic processes such as nasal vocalization and glottal stop insertion can be suppressed using “repair”—a method o...

  16. Bayesian penalized-likelihood reconstruction algorithm suppresses edge artifacts in PET reconstruction based on point-spread-function.

    Science.gov (United States)

    Yamaguchi, Shotaro; Wagatsuma, Kei; Miwa, Kenta; Ishii, Kenji; Inoue, Kazumasa; Fukushi, Masahiro

    2018-03-01

    The Bayesian penalized-likelihood reconstruction algorithm (BPL), Q.Clear, uses relative difference penalty as a regularization function to control image noise and the degree of edge-preservation in PET images. The present study aimed to determine the effects of suppression on edge artifacts due to point-spread-function (PSF) correction using a Q.Clear. Spheres of a cylindrical phantom contained a background of 5.3 kBq/mL of [ 18 F]FDG and sphere-to-background ratios (SBR) of 16, 8, 4 and 2. The background also contained water and spheres containing 21.2 kBq/mL of [ 18 F]FDG as non-background. All data were acquired using a Discovery PET/CT 710 and were reconstructed using three-dimensional ordered-subset expectation maximization with time-of-flight (TOF) and PSF correction (3D-OSEM), and Q.Clear with TOF (BPL). We investigated β-values of 200-800 using BPL. The PET images were analyzed using visual assessment and profile curves, edge variability and contrast recovery coefficients were measured. The 38- and 27-mm spheres were surrounded by higher radioactivity concentration when reconstructed with 3D-OSEM as opposed to BPL, which suppressed edge artifacts. Images of 10-mm spheres had sharper overshoot at high SBR and non-background when reconstructed with BPL. Although contrast recovery coefficients of 10-mm spheres in BPL decreased as a function of increasing β, higher penalty parameter decreased the overshoot. BPL is a feasible method for the suppression of edge artifacts of PSF correction, although this depends on SBR and sphere size. Overshoot associated with BPL caused overestimation in small spheres at high SBR. Higher penalty parameter in BPL can suppress overshoot more effectively. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  17. Genetic Algorithm-Based Model Order Reduction of Aeroservoelastic Systems with Consistant States

    Science.gov (United States)

    Zhu, Jin; Wang, Yi; Pant, Kapil; Suh, Peter M.; Brenner, Martin J.

    2017-01-01

    This paper presents a model order reduction framework to construct linear parameter-varying reduced-order models of flexible aircraft for aeroservoelasticity analysis and control synthesis in broad two-dimensional flight parameter space. Genetic algorithms are used to automatically determine physical states for reduction and to generate reduced-order models at grid points within parameter space while minimizing the trial-and-error process. In addition, balanced truncation for unstable systems is used in conjunction with the congruence transformation technique to achieve locally optimal realization and weak fulfillment of state consistency across the entire parameter space. Therefore, aeroservoelasticity reduced-order models at any flight condition can be obtained simply through model interpolation. The methodology is applied to the pitch-plant model of the X-56A Multi-Use Technology Testbed currently being tested at NASA Armstrong Flight Research Center for flutter suppression and gust load alleviation. The present studies indicate that the reduced-order model with more than 12× reduction in the number of states relative to the original model is able to accurately predict system response among all input-output channels. The genetic-algorithm-guided approach exceeds manual and empirical state selection in terms of efficiency and accuracy. The interpolated aeroservoelasticity reduced order models exhibit smooth pole transition and continuously varying gains along a set of prescribed flight conditions, which verifies consistent state representation obtained by congruence transformation. The present model order reduction framework can be used by control engineers for robust aeroservoelasticity controller synthesis and novel vehicle design.

  18. Suppressing a Sea of Starlight : enabling technology for the direct imaging of exoplanets

    NARCIS (Netherlands)

    Otten, G.P.P.L.

    2016-01-01

    In this thesis we present multiple techniques to suppress starlight in order to better directly image planets around other stars. We propose a laboratory setup to test a new focal-plane wavefront sensing technique. We also show an optical device that suppresses starlight using liquid crystals (the

  19. Semiconductor optical amplifier pattern effect suppression with passive single microring resonator-based notch filter

    Science.gov (United States)

    Rizou, Z. V.; Zoiros, K. E.; Hatziefremidis, A.

    2014-10-01

    We propose to employ a passive single microring resonator (MRR) to suppress the pattern effect in a semiconductor optical amplifier (SOA). We specify the necessary conditions that must hold in order for the MRR to act as notch filter and compensate for the uneven spectral broadening of the amplified data pulses. This procedure allows us to find the permissible range of values of the MRR radius and suitably select this parameter so that the defined design criteria are satisfied and the employed figure-of-merits are acceptable. If designed and constructed as suggested, which is feasible with state-of-the-art technology, the MRR-based notch filter enables to significantly improve the pattern-dependent SOA performance and the quality characteristics of the amplified signal.

  20. Conditioned suppression, punishment, and aversion

    Science.gov (United States)

    Orme-Johnson, D. W.; Yarczower, M.

    1974-01-01

    The aversive action of visual stimuli was studied in two groups of pigeons which received response-contingent or noncontingent electric shocks in cages with translucent response keys. Presentation of grain for 3 sec, contingent on key pecking, was the visual stimulus associated with conditioned punishment or suppression. The responses of the pigeons in three different experiments are compared.

  1. Plasma suppression of beamstrahlung: Revision

    International Nuclear Information System (INIS)

    Whittum, D.H.; Sessler, A.M.; Stewart, J.J.; Yu, S.S.

    1988-06-01

    We investigate the use of a plasma at the interaction point of two colliding beams to suppress beamstrahlung and related phenomena. We derive conditions for good current cancellation via plasma return currents and report on numerical simulations conducted to confirm our analytic results. 17 refs., 5 figs., 5 tabs

  2. Overshooting Effects in Nonequilibrium Ordering Dynamics

    DEFF Research Database (Denmark)

    Gilhøj, Henriette; Jeppesen, Claus; Mouritsen, Ole G.

    1995-01-01

    Using Monte Carlo simulation on the simplest possible statistical mechanical model, the two-dimensional, nonconserved kinetic Ising model that undergoes an order-disorder transition, we show that the local order of the ordering domains, subsequent to a temperature quench, transiently overshoots t...... the value of the equilibrium order parameter. It is argued that overshooting is a generic effect in ordering dynamics, independent of the detailed dynamics and the conservation laws in effect....

  3. Overgeneral memory and suppression of trauma memories in post-traumatic stress disorder.

    Science.gov (United States)

    Schönfeld, Sabine; Ehlers, Anke; Böllinghaus, Inga; Rief, Winfried

    2007-04-01

    The study investigated the relationship between the suppression of trauma memories and overgeneral memory in 42 assault survivors with and without PTSD. Overgeneral memory (OGM) was assessed with a standard autobiographical memory test (AMT). Participants completed two further AMTs under the instructions to either suppress or not suppress assault memories, in counterbalanced order. Participants with PTSD retrieved fewer and more general memories when following the suppression instruction than participants without PTSD, but not under the control instruction. OGM correlated with PTSD symptom severity, and measures of cognitive avoidance. The results are discussed with reference to current theories of overgeneral memory and its possible relationship with PTSD.

  4. Fluid Surface Damping: A Technique for Vibration Suppression of Beams

    Directory of Open Access Journals (Sweden)

    Hany Ghoneim

    1997-01-01

    Full Text Available A fluid surface damping (FSD technique for vibration suppression of beamlikestructures is proposed. The technique is a modification of the surface layer damping method. Two viscoelastic surface layers containing fluid-filled cavities are attached symmetrically to the opposite surfaces of the beam. The cavities on one side are attached to the corresponding cavities on the other side via connection passages. As the beam vibrates, the fluid is pumped back and forth through the connecting passages. Therefore, in addition to the viscoelastic damping provided by the surface layers, the technique offers viscous damping due to the fluid flow through the passage. A mathematical model for the proposed technique is developed, normalized, and solved in the frequency domain to investigate the effect of various parameters on the vibration suppression of a cantilever beam. The steady-state frequency response for a base white-noise excitation is calculated at the beam's free tip and over a frequency range containing the first five resonant frequencies. The parameters investigated are the flow-through passage viscous resistance, the length and location of the layers, the hydraulic capacitance of the fluid-filled cavities, and inertia of the moving fluid (hydraulic inertance. Results indicate that the proposed technique has promising potential in the field of vibration suppression of beamlike structures. With two FSD elements, all peak vibration amplitudes can be well suppressed over the entire frequency spectrum studied.

  5. Including Organizational Cultural Parameters in Work Processes

    National Research Council Canada - National Science Library

    Handley, Holly A; Heacox, Nancy J

    2004-01-01

    .... In order to represent the organizational impact on the work process, five organizational cultural parameters were identified and included in an algorithm for modeling and simulation of cultural...

  6. Adaptive suppression of passive intermodulation in digital satellite transceivers

    Directory of Open Access Journals (Sweden)

    Lu TIAN

    2017-06-01

    Full Text Available For the performance issues of satellite transceivers suffering passive intermodulation interference, a novel and effective digital suppression algorithm is presented in this paper. In contrast to analog approaches, digital passive intermodulation (PIM suppression approaches can be easily reconfigured and therefore are highly attractive for future satellite communication systems. A simplified model of nonlinear distortion from passive microwave devices is established in consideration of the memory effect. The multiple high-order PIM products falling into the receiving band can be described as a bilinear predictor function. A suppression algorithm based on a bilinear polynomial decorrelated adaptive filter is proposed for baseband digital signal processing. In consideration of the time-varying characteristics of passive intermodulation, this algorithm can achieve the rapidness of online interference estimation and low complexity with less consumption of resources. Numerical simulation results show that the algorithm can effectively compensate the passive intermodulation interference, and achieve a high signal-to-interference ratio gain.

  7. Experience with IBS-suppression lattice in RHIC

    International Nuclear Information System (INIS)

    Litvinenko, V.N.; Luo, Y.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Della Penna, A.; Drees, A.; Fedotov, A.; Ganetis, G.; Hoff, L.; Louie, W.; Malitsky, N.; Marr, G.; Marusic, A.; Montag, C.; Pilat, F.; Roser, T.; Trbojevic, D.; Tsoupas, N.

    2008-01-01

    An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-stars in the IPS. In this paper we report on the development, the tests and the performance of IBS-suppression lattice in RHIC, including the resulting increases in the peak and the average luminosity. We also report on our plans for future steps with the IBS suppression

  8. Interocular suppression prevents interference in a flanker task

    Directory of Open Access Journals (Sweden)

    Jin eFan

    2015-08-01

    Full Text Available Executive control of attention refers to processes that detect and resolve conflict among thoughts and actions. Despite the high-level nature of this faculty, the role of awareness in executive control is not well understood. In this study, we used interocular suppression to mask the flankers in an arrow flanker task, in which the flankers and the target arrow were presented simultaneously in order to elicit executive control of attention. Participants were unable to detect the flanker arrows or to reliably identify their direction when masked. There was a typical conflict effect (prolonged reaction time and increased error rate under flanker-target incongruent condition compared to congruent condition when the flanker arrows were unmasked, while the conflict effect was absent when the flanker arrows were masked with interocular suppression. These results suggest that blocking awareness of competing stimuli with interocular suppression prevents the involvement of executive control of attention.

  9. Experience with IBS-suppression lattice in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko,V.N.; Luo, Y.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Della Penna, A.; Drees, A.; Fedotov, A.; Ganetis, G.; Hoff, L.; Louie, W.; Malitsky, N.; Marr, G.; Marusic, A.; Montag, C.; Pilat, F.; Roser, T.; Trbojevic, D.; Tsoupas, N.

    2008-06-23

    An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-stars in the IPS. In this paper we report on the development, the tests and the performance of IBS-suppression lattice in RHIC, including the resulting increases in the peak and the average luminosity. We also report on our plans for future steps with the IBS suppression.

  10. Out of mind, out of sight: perceptual consequences of memory suppression.

    Science.gov (United States)

    Kim, Kyungmi; Yi, Do-Joon

    2013-04-01

    In the present study, the effect of memory suppression on subsequent perceptual processing of visual objects was examined within a modified think/no-think paradigm. Suppressing memories of visual objects significantly impaired subsequent perceptual identification of those objects when they were briefly encountered (Experiment 1) and when they were presented in noise (Experiment 2), relative to performance on baseline items for which participants did not undergo suppression training. However, in Experiment 3, when perceptual identification was performed on mirror-reversed images of to-be-suppressed objects, no impairment was observed. These findings, analogous to those showing forgetting of suppressed words in long-term memory, suggest that suppressing memories of visual objects might be mediated by direct inhibition of perceptual representations, which, in turn, impairs later perception of them. This study provides strong support for the role of inhibitory mechanisms in memory control and suggests a tight link between higher-order cognitive operations and perceptual processing.

  11. Ion suppression from blood collection devices

    DEFF Research Database (Denmark)

    Hasselstrøm, Jørgen Bo; Sejr Gothelf, Aase

    Terumo, S-monovette from Sarstedt, Vacuette from Greiner Bio-One and three BD Vacutainer serum tubes from BD. These seven different blood collection devices were used to withdraw blood from five healthy drug free donors (n=35) in random order. The samples were centrifuged and serum from each sample......The aim of the study was to examine the variation in ion suppression in ultra high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS-MS) methods when using different blood collection devices. Three different methods measuring 18 antidepressants and antipsychotics in total were...... studied. The blood collection devices were all designed to activate clot formation. They were made of glass with or without silicone coating or plastic containing silicate particles, thrombin or polystyrene particles coated with kaolin. The blood collection devises Venoject and Venosafe were supplied from...

  12. Effect of curd suppression in a milk replacer on physiological ...

    African Journals Online (AJOL)

    Effect of curd suppression in a milk replacer on physiological parameters in calves. I. Digestibility of ... Body mass-gain (kg) and efficiency of feed conversion (kg dry matter intake/kg gain) over the 28-day experimental period were respectively 7,3 and 1,8 (WM); 7,3 and 1,8 (NWM); 4,3 and 3,9 (CM) and 4,9 and 2,9 (NCM).

  13. Strangeness Suppression and Color Deconfinement

    Science.gov (United States)

    Satz, Helmut

    2018-02-01

    The relative multiplicities for hadron production in different high energy collisions are in general well described by an ideal gas of all hadronic resonances, except that under certain conditions, strange particle rates are systematically reduced. We show that the suppression factor γs, accounting for reduced strange particle rates in pp, pA and AA collisions at different collision energies, becomes a universal function when expressed in terms of the initial entropy density s0 or the initial temperature T of the produced thermal medium. It is found that γs increases from about 0.5 to 1.0 in a narrow temperature range around the quark-hadron transition temperature Tc ≃ 160 MeV. Strangeness suppression thus disappears with the onset of color deconfinement; subsequently, full equilibrium resonance gas behavior is attained.

  14. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, M.K.; Shamoun, B.I.; Bonazza, R.; Corradini, M.L. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics

    1998-01-01

    Stratified Fuel-Coolant Interaction (FCI) experiments with Refrigerant-134a and water were performed in a large-scale system. Air was uniformly injected into the coolant pool to establish a pre-existing void which could suppress the explosion. Two competing effects due to the variation of the air flow rate seem to influence the intensity of the explosion in this geometrical configuration. At low flow rates, although the injected air increases the void fraction, the concurrent agitation and mixing increases the intensity of the interaction. At higher flow rates, the increase in void fraction tends to attenuate the propagated pressure wave generated by the explosion. Experimental results show a complete suppression of the vapor explosion at high rates of air injection, corresponding to an average void fraction of larger than 30%. (author)

  15. Suppressing Quantum Fluctuations in Classicalization

    CERN Document Server

    Vikman, Alexander

    2013-01-01

    We study vacuum quantum fluctuations of simple Nambu-Goldstone bosons - derivatively coupled single scalar-field theories possessing shift-symmetry in field space. We argue that quantum fluctuations of the interacting field can be drastically suppressed with respect to the free-field case. Moreover, the power-spectrum of these fluctuations can soften to become red for sufficiently small scales. In quasiclassical approximation, we demonstrate that this suppression can only occur for those theories that admit such classical static backgrounds around which small perturbations propagate faster than light. Thus a quasiclassical softening of quantum fluctuations is only possible for theories which classicalize instead of having a usual Lorentz invariant and local Wilsonian UV- completion. We illustrate our analysis by estimating the quantum fluctuations for the DBI-like theories.

  16. Suppression of vapor cell temperature error for spin-exchange-relaxation-free magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jixi, E-mail: lujixi@buaa.edu.cn; Qian, Zheng; Fang, Jiancheng; Quan, Wei [School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China)

    2015-08-15

    This paper presents a method to reduce the vapor cell temperature error of the spin-exchange-relaxation-free (SERF) magnetometer. The fluctuation of cell temperature can induce variations of the optical rotation angle, resulting in a scale factor error of the SERF magnetometer. In order to suppress this error, we employ the variation of the probe beam absorption to offset the variation of the optical rotation angle. The theoretical discussion of our method indicates that the scale factor error introduced by the fluctuation of the cell temperature could be suppressed by setting the optical depth close to one. In our experiment, we adjust the probe frequency to obtain various optical depths and then measure the variation of scale factor with respect to the corresponding cell temperature changes. Our experimental results show a good agreement with our theoretical analysis. Under our experimental condition, the error has been reduced significantly compared with those when the probe wavelength is adjusted to maximize the probe signal. The cost of this method is the reduction of the scale factor of the magnetometer. However, according to our analysis, it only has minor effect on the sensitivity under proper operating parameters.

  17. Amphiphilic nanoparticles suppress droplet break-up in a concentrated emulsion flowing through a narrow constriction.

    Science.gov (United States)

    Gai, Ya; Kim, Minkyu; Pan, Ming; Tang, Sindy K Y

    2017-05-01

    This paper describes the break-up behavior of a concentrated emulsion comprising drops stabilized by amphiphilic silica nanoparticles flowing in a tapered microchannel. Such geometry is often used in serial droplet interrogation and sorting processes in droplet microfluidics applications. When exposed to high viscous stresses, drops can undergo break-up and compromise their physical integrity. As these drops are used as micro-reactors, such compromise leads to a loss in the accuracy of droplet-based assays. Here, we show droplet break-up is suppressed by replacing the fluoro-surfactant similar to the one commonly used in current droplet microfluidics applications with amphiphilic nanoparticles as droplet stabilizer. We identify parameters that influence the break-up of these drops and demonstrate that break-up probability increases with increasing capillary number and confinement, decreasing nanoparticle size, and is insensitive to viscosity ratio within the range tested. Practically, our results reveal two key advantages of nanoparticles with direct applications to droplet microfluidics. First, replacing surfactants with nanoparticles suppresses break-up and increases the throughput of the serial interrogation process to 3 times higher than that in surfactant system under similar flow conditions. Second, the insensitivity of break-up to droplet viscosity makes it possible to process samples having different composition and viscosities without having to change the channel and droplet geometry in order to maintain the same degree of break-up and corresponding assay accuracy.

  18. Electrostatic suppression of the Leidenfrost state using AC electric fields

    Science.gov (United States)

    Ozkan, Onur; Shahriari, Arjang; Bahadur, Vaibhav

    2017-10-01

    The formation of a vapor layer at the solid-liquid interface at high temperatures (Leidenfrost phenomenon) degrades heat transfer substantially. Application of an electric field in this vapor layer can fundamentally eliminate the Leidenfrost state by electrostatically attracting liquid towards the surface. This study analyzes the influence of AC electric fields on electrostatic suppression of the Leidenfrost state; previous studies have only utilized DC electric fields. In particular, the influence of the frequency of the AC waveform on Leidenfrost state suppression is analyzed using high speed visualization of liquid-vapor instabilities and heat transfer measurements of evaporating droplets. It is seen that the extent of suppression is reduced with increasing AC frequency. At sufficiently high frequencies, the influence of an applied voltage is completely negated, and electrostatic suppression of the Leidenfrost state can be completely eliminated. A first-order electromechanical model is used to explain the frequency-dependent reduction in the electrostatic attraction force on the Leidenfrost droplet. Overall, this work highlights the importance of AC frequency as a tool to control the extent of suppression and the boiling heat transfer rate.

  19. Order aggressiveness and order book dynamics

    DEFF Research Database (Denmark)

    Hall, Anthony D.; Hautsch, Nikolaus

    2006-01-01

    employing a six-dimensional autoregressive conditional intensity model. Using order book data from the Australian Stock Exchange, we find that market depth, the queued volume, the bid-ask spread, recent volatility, as well as recent changes in both the order flow and the price play an important role...

  20. THE ENIGMATIC ORDER

    African Journals Online (AJOL)

    tion of this order democracy made its entry into the world of chivalry ... monly referred to as 'people's de- mocracies') are solely military ... Order of the Gar- ter, the Order of the Thistle and the Or- der of the Bath as orders of merit point to the process whereby the ancient temporal orders of chivalry have be- come democratized.

  1. In the suppression of regge cut contributions

    International Nuclear Information System (INIS)

    Chia, S.P.

    1975-07-01

    It is shown that contributions of reggeon-pomeron cuts are suppressed in amplitudes with opposite natural to the reggeon. This suppression grows logarithmically with energy. The suppression in the πP cut is, however, found to be weak. Consequence on conspiracy is discussed

  2. Second order Horner's syndrome in a cat.

    Science.gov (United States)

    De Risio, Luisa; Fraser McConnell, James

    2009-08-01

    This case report describes the clinical and magnetic resonance imaging (MRI) findings of a 3.5-year-old, male neutered, domestic shorthair cat with second order Horner's syndrome as the only clinical abnormality. The neuroanatomical pathway of the sympathetic innervation to the eye, differential diagnoses for Horner's syndrome in cats, and the interpretation of pharmacological testing are reviewed. The unusual MRI findings and the value of fat-suppressed MRI sequences are discussed.

  3. Symmetric Wilson Loops beyond leading order

    Directory of Open Access Journals (Sweden)

    Xinyi Chen-Lin

    2016-12-01

    Full Text Available We study the circular Wilson loop in the symmetric representation of U(N in $\\mathcal{N} = 4$ super-Yang-Mills (SYM. In the large N limit, we computed the exponentially-suppressed corrections for strong coupling, which suggests non-perturbative physics in the dual holographic theory. We also computed the next-to-leading order term in 1/N, and the result matches with the exact result from the k-fundamental representation.

  4. Dynamic zero modes of Dirac fermions and competing singlet phases of antiferromagnetic order

    Science.gov (United States)

    Goswami, Pallab; Si, Qimiao

    2017-06-01

    In quantum spin systems, singlet phases often develop in the vicinity of an antiferromagnetic order. Typical settings for such problems arise when itinerant fermions are also present. In this paper, we develop a theoretical framework for addressing such competing orders in an itinerant system, described by Dirac fermions strongly coupled to an O(3) nonlinear sigma model. We focus on two spatial dimensions, where upon disordering the antiferromagnetic order by quantum fluctuations the singular tunneling events also known as (anti)hedgehogs can nucleate competing singlet orders in the paramagnetic phase. In the presence of an isolated hedgehog configuration of the nonlinear sigma model field, we show that the fermion determinant vanishes as the dynamic Euclidean Dirac operator supports fermion zero modes of definite chirality. This provides a topological mechanism for suppressing the tunneling events. Using the methodology of quantum chromodynamics, we evaluate the fermion determinant in the close proximity of magnetic quantum phase transition, when the antiferromagnetic order-parameter field can be described by a dilute gas of hedgehogs and antihedgehogs. We show how the precise nature of emergent singlet order is determined by the overlap between dynamic fermion zero modes of opposite chirality, localized on the hedgehogs and antihedgehogs. For a Kondo-Heisenberg model on the honeycomb lattice, we demonstrate the competition between spin Peierls order and Kondo singlet formation, thereby elucidating its global phase diagram. We also discuss other physical problems that can be addressed within this general framework.

  5. Secretoneurin suppresses cardiac hypertrophy through suppression of oxidant stress.

    Science.gov (United States)

    Chen, Hua-Li; Liu, Yan; Jiang, Wei; Wang, Xiao-Xiao; Yuan, Guo-Lin; Zhao, Yi-Lin; Yu, Chao

    2018-03-05

    The neuropeptide secretoneurin (SN) plays protective roles in myocardial ischemia. In the present study, the effect of SN in cardiac hypertrophy was investigated. We observed that, in isoproterenol (ISO) treatment induced cardiac or cardiomyocytes hypertrophy, a marked increase in the expression of endogenous SN in mouse plasma, myocardium and primary-cultured cardiomyocytes occurs. In hypertrophic mice, the heart size, heart weight/body weight (HW/BW) ratio, cardiomyocyte size, and atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) expression were significantly higher than those in controls but were effectively suppressed by SN gene therapy. Similarly, the protective effects of SN were also observed in cultured cardiomyocytes following ISO treatment. SN significantly increased the activity of catalase and superoxide dismutase (SOD) in parallel with the decrease in reactive oxygen species levels in cardiomyocytes. We observed that SN evoked the activation of all of the AMPK, P38/MAPK and ERK/MAPK pathways in cardiomyocytes, but pretreatment with only AMPK inhibitor (compound C) and ERK1/2/MAPK inhibitor (PD98059) counteracted the protective effects of SN against cardiomyocyte hypertrophy and the suppressive effects of SN on oxidant stress in cardiomyocytes. These results indicated that endogenous SN is induced in hypertrophic cardiomyocytes, and may play a protective role in the pathogenesis of cardiac hypertrophy. These results suggest that exogenous SN supplementation protects the cardiac hypertrophy induced by ISO treatment through the activation of AMPK and ERK/MAPK pathways, thus upregulating antioxidants and suppressing oxidative stress. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Variable-order fuzzy fractional PID controller.

    Science.gov (United States)

    Liu, Lu; Pan, Feng; Xue, Dingyu

    2015-03-01

    In this paper, a new tuning method of variable-order fractional fuzzy PID controller (VOFFLC) is proposed for a class of fractional-order and integer-order control plants. Fuzzy logic control (FLC) could easily deal with parameter variations of control system, but the fractional-order parameters are unable to change through this way and it has confined the effectiveness of FLC. Therefore, an attempt is made in this paper to allow all the five parameters of fractional-order PID controller vary along with the transformation of system structure as the outputs of FLC, and the influence of fractional orders λ and μ on control systems has been investigated to make the fuzzy rules for VOFFLC. Four simulation results of different plants are shown to verify the availability of the proposed control strategy. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Genetic Algorithm-Guided, Adaptive Model Order Reduction of Flexible Aircrafts

    Science.gov (United States)

    Zhu, Jin; Wang, Yi; Pant, Kapil; Suh, Peter; Brenner, Martin J.

    2017-01-01

    This paper presents a methodology for automated model order reduction (MOR) of flexible aircrafts to construct linear parameter-varying (LPV) reduced order models (ROM) for aeroservoelasticity (ASE) analysis and control synthesis in broad flight parameter space. The novelty includes utilization of genetic algorithms (GAs) to automatically determine the states for reduction while minimizing the trial-and-error process and heuristics requirement to perform MOR; balanced truncation for unstable systems to achieve locally optimal realization of the full model; congruence transformation for "weak" fulfillment of state consistency across the entire flight parameter space; and ROM interpolation based on adaptive grid refinement to generate a globally functional LPV ASE ROM. The methodology is applied to the X-56A MUTT model currently being tested at NASA/AFRC for flutter suppression and gust load alleviation. Our studies indicate that X-56A ROM with less than one-seventh the number of states relative to the original model is able to accurately predict system response among all input-output channels for pitch, roll, and ASE control at various flight conditions. The GA-guided approach exceeds manual and empirical state selection in terms of efficiency and accuracy. The adaptive refinement allows selective addition of the grid points in the parameter space where flight dynamics varies dramatically to enhance interpolation accuracy without over-burdening controller synthesis and onboard memory efforts downstream. The present MOR framework can be used by control engineers for robust ASE controller synthesis and novel vehicle design.

  8. Model Order Reduction of Aeroservoelastic Model of Flexible Aircraft

    Science.gov (United States)

    Wang, Yi; Song, Hongjun; Pant, Kapil; Brenner, Martin J.; Suh, Peter

    2016-01-01

    This paper presents a holistic model order reduction (MOR) methodology and framework that integrates key technological elements of sequential model reduction, consistent model representation, and model interpolation for constructing high-quality linear parameter-varying (LPV) aeroservoelastic (ASE) reduced order models (ROMs) of flexible aircraft. The sequential MOR encapsulates a suite of reduction techniques, such as truncation and residualization, modal reduction, and balanced realization and truncation to achieve optimal ROMs at grid points across the flight envelope. The consistence in state representation among local ROMs is obtained by the novel method of common subspace reprojection. Model interpolation is then exploited to stitch ROMs at grid points to build a global LPV ASE ROM feasible to arbitrary flight condition. The MOR method is applied to the X-56A MUTT vehicle with flexible wing being tested at NASA/AFRC for flutter suppression and gust load alleviation. Our studies demonstrated that relative to the fullorder model, our X-56A ROM can accurately and reliably capture vehicles dynamics at various flight conditions in the target frequency regime while the number of states in ROM can be reduced by 10X (from 180 to 19), and hence, holds great promise for robust ASE controller synthesis and novel vehicle design.

  9. Background Suppression Effects on Signal Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Burr, Tom [Los Alamos National Laboratory

    2008-01-01

    Gamma detectors at border crossings are intended to detect illicit nuclear material. One performance challenge involves the fact that vehicles suppress the natural background, thus potentially reducing detection probability for threat items. Methods to adjust for background suppression have been considered in related but different settings. Here, methods to adjust for background suppression are tested in the context of signal estimation. Adjustment methods include several clustering options. We find that for the small-to-moderate suppression magnitudes exhibited in the analyzed data, suppression adjustment is only moderatel helpful in locating the signal peak, and in estimating its width or magnitude.

  10. Behavioural Pattern of Causality Parameter of Autoregressive ...

    African Journals Online (AJOL)

    In this paper, a causal form of Autoregressive Moving Average process, ARMA (p, q) of various orders and behaviour of the causality parameter of ARMA model is investigated. It is deduced that the behaviour of causality parameter ψi depends on positive and negative values of autoregressive parameter φ and moving ...

  11. Suppression effects on musical and verbal memory.

    Science.gov (United States)

    Schendel, Zachary A; Palmer, Caroline

    2007-06-01

    Three experiments contrasted the effects of articulatory suppression on recognition memory for musical and verbal sequences. In Experiment 1, a standard/comparison task was employed, with digit or note sequences presented visually or auditorily while participants remained silent or produced intermittent verbal suppression (saying "the") or musical suppression (singing "la"). Both suppression types decreased performance by equivalent amounts, as compared with no suppression. Recognition accuracy was lower during suppression for visually presented digits than during that for auditorily presented digits (consistent with phonological loop predictions), whereas accuracy was equivalent for visually presented notes and auditory tones. When visual interference filled the retention interval in Experiment 2, performance with visually presented notes but not digits was impaired. Experiment 3 forced participants to translate visually presented music sequences by presenting comparison sequences auditorily. Suppression effects for visually presented music resembled those for digits only when the recognition task required sensory translation of cues.

  12. High-Order Frequency-Locked Loops

    DEFF Research Database (Denmark)

    Golestan, Saeed; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    of knowledge is attributable to the difficulty of small-signal modeling of these high-order FLLs, which has limited their analysis to numerical studies. Focusing on three-phase FLLs, the idea of designing high-order FLLs is first generalized in this letter. Then, a second-order FLL is considered as the case...... study, and its small-signal modeling, stability analysis, and parameter tuning are presented. Finally, to gain insight about advantages and disadvantages of high-order FLLs, a theoretical and experimental performance comparison between the designed second-order FLL and a standard FLL (first-order FLL...

  13. Noise Suppression for Dual-Energy CT Through Entropy Minimization.

    Science.gov (United States)

    Petrongolo, Michael; Zhu, Lei

    2015-11-01

    In dual energy CT (DECT), noise amplification during signal decomposition significantly limits the utility of basis material images. Since clinically relevant objects typically contain a limited number of different materials, we propose an Image-domain Decomposition method through Entropy Minimization (IDEM) for noise suppression in DECT. Pixels of decomposed images are first linearly transformed into 2D clusters of data points, which are highly asymmetric due to strong signal correlation. An optimal axis is identified in the 2D space via numerical search such that the projection of data clusters onto the axis has minimum entropy. Noise suppression is performed on each image pixel by estimating the center-of-mass value of each data cluster along the direction perpendicular to the projection axis. The IDEM method is distinct from other noise suppression techniques in that it does not suppress pixel noise by reducing spatial variation between neighboring pixels. As supported by studies on Catphan©600 and anthropomorphic head phantoms, this feature endows our algorithm with a unique capability of reducing noise standard deviation on DECT decomposed images by approximately one order of magnitude while preserving spatial resolution and image noise power spectra (NPS). Compared with a filtering method and recently developed iterative method at the same level of noise suppression, the IDEM algorithm obtains high-resolution images with less artifacts. It also maintains accuracy of electron density measurements with less than 2% bias error. The IDEM method effectively suppresses noise of DECT for quantitative use, with appealing features on preservation of image spatial resolution and NPS.

  14. Optical atomic clocks with suppressed black body radiation shift

    OpenAIRE

    Kozlov, Alexander; Dzuba, Vladimir; Flambaum, Victor

    2014-01-01

    We study a wide range of neutral atoms and ions suitable for ultra-precise atomic optical clocks with naturally suppressed black body radiation shift of clock transition frequency. Calculations show that scalar polarizabilities of clock states cancel each other for at least one order of magnitude for considered systems. Results for calculations of frequencies, quadrupole moments of the states, clock transition amplitudes and natural widths of upper clock states are presented.

  15. Multichannel photonic mixing based on cascade carrier suppression

    Science.gov (United States)

    Xu, Fangxing

    2015-10-01

    Designed a multi-channel photonic mixing system based on cascade carrier suppression, which can achieve frequency conversions simultaneously for multi-channels, effectively inhibit the generation of third-order intermodulation, and significantly reduce the insertion loss in the conversion process. Meanwhile, a simulation with the software Optisystem has been done, indicating excellent frequency-conversion characteristics and good scalability of this scheme, that shows the microwave photonic frequency conversion can be a potential application for microwave signal parallel processing.

  16. Nuclear reactor scram suppression device

    International Nuclear Information System (INIS)

    Koshi, Hiroshi; Ozawa, Hisamitsu.

    1993-01-01

    The device of the present invention suppresses reactor scram due to increase of neutrons caused by pressure elevation in the reactor even when a portion of main steam pipes is closed by some or other causes such as closure of a main steam isolation valve in a BWR type power plant. That is, when a flow channel is closed, such as upon closure of a main steam isolation valve, a flow rate signal sent from each of main steam flow rate detection means is inputted to a selective circuit of a pressure control device, from which a normal value is obtained. A deviation value for each of the main steam flow rate values is determined from the value described above and a flow rate average value obtained in an averaging circuit. Abnormality in the main steam pipelines is judged if a level for each of the deviation values is greater than a predetermined value. Further, the insertion of selective control rods and trip and run back instructions for recycling pumps are controlled by output signals of the deviation value detection circuit, to decrease the reactor power and prevent elevation in the reactor. As a result, reactor scram due to increase of neutron fluxes is suppressed. (I.S.)

  17. Higher-Order Program Generation

    DEFF Research Database (Denmark)

    Rhiger, Morten

    for OCaml, a dialect of ML, that provides run-time code generation for OCaml programs. We apply these byte-code combinators in semantics-directed compilation for an imperative language and in run-time specialization using type-directed partial evaluation. Finally, we present an approach to compiling goal......This dissertation addresses the challenges of embedding programming languages, specializing generic programs to specific parameters, and generating specialized instances of programs directly as executable code. Our main tools are higher-order programming techniques and automatic program generation...... infrastructure of higher-order functions, types, and modules. Furthermore, it has been observed that embedded programs can be restricted to those having simple types using a technique called ``phantom types''. We prove, using an idealized higher-order language, that such an embedding is sound (i.e., when all...

  18. Supersymmetry Parameter Analysis with Fittino

    Energy Technology Data Exchange (ETDEWEB)

    Bechtle, Philip; /SLAC; Desch, Klaus; Wienemann, Peter; /Freiburg U.

    2005-06-24

    We present the results of a realistic global fit of the Lagrangian parameters of the Minimal Supersymmetric Standard Model to simulated data from ILC and LHC with realistic estimates of the observable uncertainties. Higher order radiative corrections are accounted for where ever possible to date. Results are obtained for a modified SPS1a MSSM benchmark scenario but they were checked not to depend critically on this assumption. Exploiting a simulated annealing algorithm, a stable result is obtained without any a priori assumptions on the fit parameters. Most of the Lagrangian parameters can be extracted at the percent level or better if theoretical uncertainties are neglected. Neither LHC nor ILC measurements alone will be sufficient to obtain a stable result. The effects of theoretical uncertainties arising from unknown higher-order corrections and parametric uncertainties are examined qualitatively. They appear to be relevant and the result motivates further precision calculations.

  19. varying elastic parameters distributions

    KAUST Repository

    Moussawi, Ali

    2014-12-01

    The experimental identication of mechanical properties is crucial in mechanics for understanding material behavior and for the development of numerical models. Classical identi cation procedures employ standard shaped specimens, assume that the mechanical elds in the object are homogeneous, and recover global properties. Thus, multiple tests are required for full characterization of a heterogeneous object, leading to a time consuming and costly process. The development of non-contact, full- eld measurement techniques from which complex kinematic elds can be recorded has opened the door to a new way of thinking. From the identi cation point of view, suitable methods can be used to process these complex kinematic elds in order to recover multiple spatially varying parameters through one test or a few tests. The requirement is the development of identi cation techniques that can process these complex experimental data. This thesis introduces a novel identi cation technique called the constitutive compatibility method. The key idea is to de ne stresses as compatible with the observed kinematic eld through the chosen class of constitutive equation, making possible the uncoupling of the identi cation of stress from the identi cation of the material parameters. This uncoupling leads to parametrized solutions in cases where 5 the solution is non-unique (due to unknown traction boundary conditions) as demonstrated on 2D numerical examples. First the theory is outlined and the method is demonstrated in 2D applications. Second, the method is implemented within a domain decomposition framework in order to reduce the cost for processing very large problems. Finally, it is extended to 3D numerical examples. Promising results are shown for 2D and 3D problems.

  20. Adjusted priors for Bayes factors involving reparameterized order constraints

    NARCIS (Netherlands)

    Heck, D.W.; Wagenmakers, E.-J.

    Many psychological theories that are instantiated as statistical models imply order constraints on the model parameters. To fit and test such restrictions, order constraints of the form θi≤θj can be reparameterized with auxiliary parameters η∈[0,1] to replace the original parameters by θi=η⋅θj. This

  1. Heat transfer enhancement accompanying Leidenfrost state suppression at ultrahigh temperatures.

    Science.gov (United States)

    Shahriari, Arjang; Wurz, Jillian; Bahadur, Vaibhav

    2014-10-14

    The well-known Leidenfrost effect is the formation of a vapor layer between a liquid and an underlying hot surface. This insulating vapor layer severely degrades heat transfer and results in surface dryout. We measure the heat transfer enhancement and dryout prevention benefits accompanying electrostatic suppression of the Leidenfrost state. Interfacial electric fields in the vapor layer can attract liquid toward the surface and promote wetting. This principle can suppress dryout even at ultrahigh temperatures exceeding 500 °C, which is more than 8 times the Leidenfrost superheat for organic solvents. Robust Leidenfrost state suppression is observed for a variety of liquids, ranging from low electrical conductivity organic solvents to electrically conducting salt solutions. Elimination of the vapor layer increases heat dissipation capacity by more than 1 order of magnitude. Heat removal capacities exceeding 500 W/cm(2) are measured, which is 5 times the critical heat flux (CHF) of water on common engineering surfaces. Furthermore, the heat transfer rate can be electrically controlled by the applied voltage. The underlying science is explained via a multiphysics analytical model which captures the coupled electrostatic-fluid-thermal transport phenomena underlying electrostatic Leidenfrost state suppression. Overall, this work uncovers the physics underlying dryout prevention and demonstrates electrically tunable boiling heat transfer with ultralow power consumption.

  2. ADAPTIVE MESH REFINEMENT SIMULATIONS OF GALAXY FORMATION: EXPLORING NUMERICAL AND PHYSICAL PARAMETERS

    International Nuclear Information System (INIS)

    Hummels, Cameron B.; Bryan, Greg L.

    2012-01-01

    We carry out adaptive mesh refinement cosmological simulations of Milky Way mass halos in order to investigate the formation of disk-like galaxies in a Λ-dominated cold dark matter model. We evolve a suite of five halos to z = 0 and find a gas disk formation in each; however, in agreement with previous smoothed particle hydrodynamics simulations (that did not include a subgrid feedback model), the rotation curves of all halos are centrally peaked due to a massive spheroidal component. Our standard model includes radiative cooling and star formation, but no feedback. We further investigate this angular momentum problem by systematically modifying various simulation parameters including: (1) spatial resolution, ranging from 1700 to 212 pc; (2) an additional pressure component to ensure that the Jeans length is always resolved; (3) low star formation efficiency, going down to 0.1%; (4) fixed physical resolution as opposed to comoving resolution; (5) a supernova feedback model that injects thermal energy to the local cell; and (6) a subgrid feedback model which suppresses cooling in the immediate vicinity of a star formation event. Of all of these, we find that only the last (cooling suppression) has any impact on the massive spheroidal component. In particular, a simulation with cooling suppression and feedback results in a rotation curve that, while still peaked, is considerably reduced from our standard runs.

  3. Bottomonium suppression using a lattice QCD vetted potential

    Science.gov (United States)

    Krouppa, Brandon; Rothkopf, Alexander; Strickland, Michael

    2018-01-01

    We estimate bottomonium yields in relativistic heavy-ion collisions using a lattice QCD vetted, complex-valued, heavy-quark potential embedded in a realistic, hydrodynamically evolving medium background. We find that the lattice-vetted functional form and temperature dependence of the proper heavy-quark potential dramatically reduces the dependence of the yields on parameters other than the temperature evolution, strengthening the picture of bottomonium as QGP thermometer. Our results also show improved agreement between computed yields and experimental data produced in RHIC 200 GeV /nucleon collisions. For LHC 2.76 TeV /nucleon collisions, the excited states, whose suppression has been used as a vital sign for quark-gluon-plasma production in a heavy-ion collision, are reproduced better than previous perturbatively-motivated potential models; however, at the highest LHC energies our estimates for bottomonium suppression begin to underestimate the data. Possible paths to remedy this situation are discussed.

  4. A dual purpose Compton suppression spectrometer

    CERN Document Server

    Parus, J; Raab, W; Donohue, D

    2003-01-01

    A gamma-ray spectrometer with a passive and an active shield is described. It consists of a HPGe coaxial detector of 42% efficiency and 4 NaI(Tl) detectors. The energy output pulses of the Ge detector are delivered into the 3 spectrometry chains giving the normal, anti- and coincidence spectra. From the spectra of a number of sup 1 sup 3 sup 7 Cs and sup 6 sup 0 Co sources a Compton suppression factor, SF and a Compton reduction factor, RF, as the parameters characterizing the system performance, were calculated as a function of energy and source activity and compared with those given in literature. The natural background is reduced about 8 times in the anticoincidence mode of operation, compared to the normal spectrum which results in decreasing the detection limits for non-coincident gamma-rays up to a factor of 3. In the presence of other gamma-ray activities, in the range from 5 to 11 kBq, non- and coincident, the detection limits can be decreased for some nuclides by a factor of 3 to 5.7.

  5. First-order inflation

    International Nuclear Information System (INIS)

    Kolb, E.W.

    1991-01-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been reviewed. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result if inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. (orig.)

  6. First-order inflation

    International Nuclear Information System (INIS)

    Kolb, E.W.; Chicago Univ., IL

    1990-09-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result in inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. 58 refs., 3 figs

  7. SNV's modes of ordering

    NARCIS (Netherlands)

    Hummel, John; Duim, van der Rene

    2016-01-01

    This article adopts an aidnographic approach to examine how internal organizational modes of ordering have influenced tourism development practices of SNV Netherlands Development Organisation (SNV). Our research revealed six modes of ordering: administration, project management, enterprising,

  8. First-order inflation

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, E.W. (Fermi National Accelerator Lab., Batavia, IL (USA) Chicago Univ., IL (USA). Enrico Fermi Inst.)

    1990-09-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result in inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. 58 refs., 3 figs.

  9. Safety system for pressure suppression

    International Nuclear Information System (INIS)

    Wood, L.E.; Ludwig, G.J.; Tulsa, O.

    1975-01-01

    The rupture disk with rated breaking points is constrained by two supporting elements and has a convex-concave shape. For pressure suppression, it is reversable inversely to its bulging. Its surface has notches which are the rated breaking points and respond to higher pressures. The centre of the rupture disk contains an area of relatively smaller thickness that will burst at lower pressure and thus makes it applicable for lower pressures. For the response of the rupture disk centre, a thrust ring with a central opening may also be used. Its edge is formed into a convex-concave section supported on the edge of the rupture disk on the exit side. The free centre of the rupture disk is then the area of relative weakness. (RW/AK) [de

  10. MEK5 suppresses osteoblastic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Kaneshiro, Shoichi [Department of Orthopaedic Surgery, Japan Community Health Care Organization Osaka Hospital, 4-2-78 Fukushima, Fukushima Ward, Osaka City, Osaka 553-0003 (Japan); Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Otsuki, Dai; Yoshida, Kiyoshi; Yoshikawa, Hideki [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Higuchi, Chikahisa, E-mail: c-higuchi@umin.ac.jp [Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-07-31

    Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase (MAPK) family and is activated by its upstream kinase, MAPK kinase 5 (MEK5), which is a member of the MEK family. Although the role of MEK5 has been investigated in several fields, little is known about its role in osteoblastic differentiation. In this study, we have demonstrated the role of MEK5 in osteoblastic differentiation in mouse preosteoblastic MC3T3-E1 cells and bone marrow stromal ST2 cells. We found that treatment with BIX02189, an inhibitor of MEK5, increased alkaline phosphatase (ALP) activity and the gene expression of ALP, osteocalcin (OCN) and osterix, as well as it enhanced the calcification of the extracellular matrix. Moreover, osteoblastic cell proliferation decreased at a concentration of greater than 0.5 μM. In addition, knockdown of MEK5 using siRNA induced an increase in ALP activity and in the gene expression of ALP, OCN, and osterix. In contrast, overexpression of wild-type MEK5 decreased ALP activity and attenuated osteoblastic differentiation markers including ALP, OCN and osterix, but promoted cell proliferation. In summary, our results indicated that MEK5 suppressed the osteoblastic differentiation, but promoted osteoblastic cell proliferation. These results implied that MEK5 may play a pivotal role in cell signaling to modulate the differentiation and proliferation of osteoblasts. Thus, inhibition of MEK5 signaling in osteoblasts may be of potential use in the treatment of osteoporosis. - Highlights: • MEK5 inhibitor BIX02189 suppresses proliferation of osteoblasts. • MEK5 knockdown and MEK5 inhibitor promote differentiation of osteoblasts. • MEK5 overexpression inhibits differentiation of osteoblasts.

  11. Inventory order crossovers

    NARCIS (Netherlands)

    Riezebos, J.

    2006-01-01

    The control policies that are used in inventory management systems assume that orders arrive in the same sequence as they were ordered. Due to changes in supply chains and markets, this assumption is no longer valid. This paper aims at providing an improved understanding of the phenomenon of order

  12. Assessing the efficiency of Wolbachia driven Aedes mosquito suppression by delay differential equations.

    Science.gov (United States)

    Huang, Mugen; Luo, Jiaowan; Hu, Linchao; Zheng, Bo; Yu, Jianshe

    2017-12-14

    To suppress wild population of Aedes mosquitoes, the primary transmission vector of life-threatening diseases such as dengue, malaria, and Zika, an innovative strategy is to release male mosquitoes carrying the bacterium Wolbachia into natural areas to drive female sterility by cytoplasmic incompatibility. We develop a model of delay differential equations, incorporating the strong density restriction in the larval stage, to assess the delicate impact of life table parameters on suppression efficiency. Through mathematical analysis, we find the sufficient and necessary condition for global stability of the complete suppression state. This condition, combined with the experimental data for Aedes albopictus population in Guangzhou, helps us predict a large range of releasing intensities for suppression success. In particular, we find that if the number of released infected males is no less than four times the number of mosquitoes in wild areas, then the mosquito density in the peak season can be reduced by 95%. We introduce an index to quantify the dependence of suppression efficiency on parameters. The invariance of some quantitative properties of the index values under various perturbations of the same parameter justifies the applicability of this index, and the robustness of our modeling approach. The index yields a ranking of the sensitivity of all parameters, among which the adult mortality has the highest sensitivity and is considerably more sensitive than the natural larvae mortality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. How to Handle Anxiety: The Effects of Reappraisal, Acceptance, and Suppression Strategies on Anxious Arousal

    Science.gov (United States)

    Hofmann, Stefan G.; Heering, Sanna; Sawyer, Alice T.; Asnaani, Anu

    2009-01-01

    It has been suggested that reappraisal strategies are more effective than suppression strategies for regulating emotions. Recently, proponents of the acceptance-based behavior therapy movement have further emphasized the importance of acceptance-based emotion regulation techniques. In order to directly compare these different emotion regulation strategies, 202 volunteers were asked to give an impromptu speech in front of a video camera. Participants were randomly assigned to one of three groups. The Reappraisal group was instructed to regulate their anxious arousal by reappraising the situation; the Suppression group was asked to suppress their anxious behaviors; and the Acceptance group was instructed to accept their anxiety. As expected, the Suppression group showed a greater increase in heart rate from baseline than the Reappraisal and Acceptance groups. Moreover, the Suppression group reported more anxiety than the Reappraisal group. However, the Acceptance and Suppression groups did not differ in their subjective anxiety response. These results suggest that both reappraising and accepting anxiety is more effective for moderating the physiological arousal than suppressing anxiety. However, reappraising is more effective for moderating the subjective feeling of anxiety than attempts to suppress or accept it. PMID:19281966

  14. Suppression of blow up by a logistic source in 2D Keller-Segel system with fractional dissipation

    Science.gov (United States)

    Burczak, Jan; Granero-Belinchón, Rafael

    2017-11-01

    We consider a two dimensional parabolic-elliptic Keller-Segel equation with a fractional diffusion of order α ∈ (0 , 2) and a logistic term. In the case of an analogous problem with standard diffusion, introduction of the logistic term, well motivated by biological applications, results in global smoothness of solutions (i.e. suppression of blowup), compare Tello & Winkler [48]. We show that this phenomenon extends into potentially less regular case of fractional diffusions. Namely, we obtain existence of global in time regular solutions emanating from initial data with no size restrictions for c < α < 2, where c ∈ (0 , 2) depends on the equation's parameters. For an even wider range of α‧ s, we prove existence of global in time weak solution for general initial data.

  15. Impedance Based Analysis of DFIG Stator Current Unbalance and Distortion Suppression Strategies

    DEFF Research Database (Denmark)

    Song, Yipeng; Zhou, Dao; Blaabjerg, Frede

    2016-01-01

    reshaping though the introduction of R and VPI regulator. It is pointed out that, when implemented in the DFIG system output current unbalance and distortion suppression, the VPI regulator (equivalent to the combination of virtual positive inductor and virtual positive resistor) has two advantages over R...... regulator (equivalent to the combination of virtual positive resistor and virtual negative inductor), i.e., better high order harmonic distortion suppression. The theoretical analysis and MATLAB simulation results have validated the correctness of this conclusion....

  16. Photoperiodic suppression of drug reinstatement.

    Science.gov (United States)

    Sorg, B A; Stark, G; Sergeeva, A; Jansen, H T

    2011-03-10

    The rewarding influence of drugs of abuse varies with time of day and appears to involve interactions between the circadian and the mesocorticolimbic dopamine systems. The circadian system is also intimately involved in measuring daylength. Thus, the present study examined the impact of changing daylength (photoperiod) on cocaine-seeking behaviors. Male Sprague-Dawley rats were trained and tested on a 12L:12D light:dark schedule for cocaine-induced reinstatement of conditioned place preference (CPP) at three times of day (Zeitgeber time (ZT): 4, 12, and 20) to determine a preference score. Rats were then shifted to either shorter (6L:18D) or longer (18L:6D) photoperiods and then to constant conditions, re-tested for cocaine-induced reinstatement under each different condition, and then returned to their original photoperiod (12L:12D) and tested once more. Rats exhibited a circadian profile of preference score in constant darkness with a peak at 12 h after lights-off. At both ZT4 and ZT20, but not at ZT12, shorter photoperiods profoundly suppressed cocaine reinstatement, which did not recover even after switching back to 12L:12D. In contrast, longer photoperiods did not alter reinstatement. Separate studies showed that the suppression of cocaine reinstatement was not due to repeated testing. In an additional experiment, we examined the photoperiodic regulation of tyrosine hydroxylase (TH) and dopamine transporter (DAT) proteins in drug-naive rats. These results revealed photoperiodic modulation of proteins in the prefrontal cortex and dorsal striatum, but not in the nucleus accumbens or ventral tegmental area. Together, these findings add further support to the circadian genesis of cocaine-seeking behaviors and demonstrate that drug-induced reinstatement is modulated by photoperiod. Furthermore, the results suggest that photoperiod partly contributes to the seasonal expression of certain drug-related behaviors in humans living at different latitudes and thus our

  17. Booster parameter list

    International Nuclear Information System (INIS)

    Parsa, Z.

    1986-10-01

    The AGS Booster is designed to be an intermediate synchrotron injector for the AGS, capable of accelerating protons from 200 MeV to 1.5 GeV. The parameters listed include beam and operational parameters and lattice parameters, as well as parameters pertaining to the accelerator's magnets, vacuum system, radio frequency acceleration system, and the tunnel. 60 refs., 41 figs

  18. Lumped-parameter models

    Energy Technology Data Exchange (ETDEWEB)

    Ibsen, Lars Bo; Liingaard, M.

    2006-12-15

    A lumped-parameter model represents the frequency dependent soil-structure interaction of a massless foundation placed on or embedded into an unbounded soil domain. In this technical report the steps of establishing a lumped-parameter model are presented. Following sections are included in this report: Static and dynamic formulation, Simple lumped-parameter models and Advanced lumped-parameter models. (au)

  19. Fractional-order devices

    CERN Document Server

    Biswas, Karabi; Caponetto, Riccardo; Mendes Lopes, António; Tenreiro Machado, José António

    2017-01-01

    This book focuses on two specific areas related to fractional order systems – the realization of physical devices characterized by non-integer order impedance, usually called fractional-order elements (FOEs); and the characterization of vegetable tissues via electrical impedance spectroscopy (EIS) – and provides readers with new tools for designing new types of integrated circuits. The majority of the book addresses FOEs. The interest in these topics is related to the need to produce “analogue” electronic devices characterized by non-integer order impedance, and to the characterization of natural phenomena, which are systems with memory or aftereffects and for which the fractional-order calculus tool is the ideal choice for analysis. FOEs represent the building blocks for designing and realizing analogue integrated electronic circuits, which the authors believe hold the potential for a wealth of mass-market applications. The freedom to choose either an integer- or non-integer-order analogue integrator...

  20. On nonlinear reduced order modeling

    International Nuclear Information System (INIS)

    Abdel-Khalik, Hany S.

    2011-01-01

    When applied to a model that receives n input parameters and predicts m output responses, a reduced order model estimates the variations in the m outputs of the original model resulting from variations in its n inputs. While direct execution of the forward model could provide these variations, reduced order modeling plays an indispensable role for most real-world complex models. This follows because the solutions of complex models are expensive in terms of required computational overhead, thus rendering their repeated execution computationally infeasible. To overcome this problem, reduced order modeling determines a relationship (often referred to as a surrogate model) between the input and output variations that is much cheaper to evaluate than the original model. While it is desirable to seek highly accurate surrogates, the computational overhead becomes quickly intractable especially for high dimensional model, n ≫ 10. In this manuscript, we demonstrate a novel reduced order modeling method for building a surrogate model that employs only 'local first-order' derivatives and a new tensor-free expansion to efficiently identify all the important features of the original model to reach a predetermined level of accuracy. This is achieved via a hybrid approach in which local first-order derivatives (i.e., gradient) of a pseudo response (a pseudo response represents a random linear combination of original model’s responses) are randomly sampled utilizing a tensor-free expansion around some reference point, with the resulting gradient information aggregated in a subspace (denoted by the active subspace) of dimension much less than the dimension of the input parameters space. The active subspace is then sampled employing the state-of-the-art techniques for global sampling methods. The proposed method hybridizes the use of global sampling methods for uncertainty quantification and local variational methods for sensitivity analysis. In a similar manner to

  1. Suppression and repression: A theoretical discussion illustrated by a movie

    Directory of Open Access Journals (Sweden)

    Maria Lucia de Souza Campos Paiva

    2012-02-01

    Full Text Available The first translations of Freud's work into Portuguese have presented problems because they were not translated from the German language. More than a hundred years after the beginning of Psychoanalysis, there are still many discussions on Freud's metapsychology and a considerable difficulty in obtaining a consensus on the translation of some concepts. This paper refers back to Freud's concepts of primal repression, repression and suppression. In order to discuss such concepts, we have made use of a film, co-produced by Germans and Argentineans, which is named "The Song in me" (Das Lied in mir, released to the public in 2011 and directed by Florian Micoud Cossen. Through this motion picture, the following of Freud's concepts are analyzed, and the differentiation between them is discussed: suppression and repression, as well as the importance of their precise translation.

  2. Kalman filtering to suppress spurious signals in Adaptive Optics control

    Energy Technology Data Exchange (ETDEWEB)

    Poyneer, L; Veran, J P

    2010-03-29

    In many scenarios, an Adaptive Optics (AO) control system operates in the presence of temporally non-white noise. We use a Kalman filter with a state space formulation that allows suppression of this colored noise, hence improving residual error over the case where the noise is assumed to be white. We demonstrate the effectiveness of this new filter in the case of the estimated Gemini Planet Imager tip-tilt environment, where there are both common-path and non-common path vibrations. We discuss how this same framework can also be used to suppress spatial aliasing during predictive wavefront control assuming frozen flow in a low-order AO system without a spatially filtered wavefront sensor, and present experimental measurements from Altair that clearly reveal these aliased components.

  3. Menstrual suppression for adolescents with developmental disabilities.

    Science.gov (United States)

    Savasi, I; Spitzer, R F; Allen, L M; Ornstein, M P

    2009-06-01

    The approach to menstrual suppression for adolescents with developmental disabilities has evolved considerably over the years due to changing philosophies and evolving treatment options. We review the medical management options available for menstrual suppression with a focus on the needs and treatment of adolescents with developmental disabilities.

  4. Suppression of fertility in adult cats

    DEFF Research Database (Denmark)

    Goericke-Pesch, Sandra Kathrin; Wehrend, A.; Georgiev, P.

    2014-01-01

    and clinical options are available for the suppression of fertility in adult cats and the decision as to which should be chosen - independent of the legal registration of any state - depends on different facts: (i) feral or privately owned animal? (ii) temporary or permanent suppression of fertility wanted...

  5. Simulation analysis of a wildfire suppression system

    Science.gov (United States)

    Abílio Pereira Pacheco; João Claro; Tiago. Oliveira

    2013-01-01

    Rekindles and false alarms are unusually high in the Portuguese wildfire management system, representing a high burden on suppression resources in particular, and fire management resources in general. In 20,049 occurrences that the suppression system handled in the summer of 2010, 12.5% were false alarms and 15.0% were rekindles. We present a discreteevent simulation...

  6. Transnational Normative Orders

    DEFF Research Database (Denmark)

    Kjaer, Poul F.

    2013-01-01

    by a protracted dual movement where the expansion and densification of statehood and autonomous forms of transnational ordering gradually emerged in a mutually constitutive fashion. One implication of this is that neither the concept of the state nor the concept of nonstate transnational entities is adequately...... of the law of normative orders has been introduced, specifying them as respectively oriented towards establishing internal condensation of a given normative order and external compatibility between different normative orders. With this background, a framework for the analysis of constitutional frameworks...

  7. Transnational Normative Orders

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2017-01-01

    by a protracted dual movement where the expansion and densification of statehood and autonomous forms of transnational ordering gradually emerged in a mutually constitutive fashion. One implication of this is that neither the concept of the state nor the concept of nonstate transnational entities is adequately...... of the law of normative orders has been introduced, specifying them as respectively oriented towards establishing internal condensation of a given normative order and external compatibility between different normative orders. With this background, a framework for the analysis of constitutional frameworks...

  8. Self-noise suppression schemes in blind image steganography

    Science.gov (United States)

    Ramkumar, Mahalingam; Akansu, Ali N.

    1999-11-01

    Blind or oblivious data hiding, can be considered as a signaling method where the origin of the signal constellation is not known. The origin however, can be estimated, by means of self-noise suppression techniques. In this paper, we propose such a technique, and present both theoretical and numerical evaluations of its performance in an additive noise scenario. The problem of optimal choice of the parameters of the proposed technique is also explored, and solutions are presented. Though the cover object is assumed to be an image for purposes of illustration, the proposed method is equally applicable for other types of multimedia data, like video, speech or music.

  9. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    Objectives: Cystic fibrosis patients are commonly infected by Pseudomonas aeruginosa, but Aspergilli are also frequently isolated. Our aim was to examine the possible interaction between P. aeruginosa and different Aspergillus. Methods: A suspension of 106 fungal spores/ml was streaked onto WATM......, here among 2-heptyl-3-hydroxy-4-quinolone (PQS). An unidentified green pseudomonas compound was also observed. Interestingly the P. aeruginosa mutant rpoN was unable to suppress A. fumigatus, but suppressed A. flavus, A. oryzae and A. niger. However several other P. aeruginosa mutants suppressed A....... fumigatus including flif, pilA, lasR, PVDA, PQSC and rhlA mutants indicating that phenazines may be involved in the suppressed growth of A. fumigatus. All pseudomonas mutants suppressed A. oryzae, A. niger and A. flavus. Conclusions: An increase in phenazine production by P. aeruginosa may contribute...

  10. Emotion suppression, not reappraisal, predicts psychotherapy outcome.

    Science.gov (United States)

    Scherer, Anne; Boecker, Maren; Pawelzik, Markus; Gauggel, Siegfried; Forkmann, Thomas

    2017-03-01

    The aim of this study was to identify whether trait emotion regulation strategies predict successful or unsuccessful psychotherapy outcomes in cognitive behaviour therapy. Three emotion regulation strategies (reappraisal, suppression, and externalizing behaviour) were assessed in 358 in- and outpatients. Patients were then grouped by therapy outcome. Emotion regulation strategies and confounding variables were entered as predictors in multinomial logistic regression analyses. Emotion suppression, but not reappraisal, was found to predict therapy outcomes for in- and outpatients, with patients high in suppression experiencing worse outcomes. Externalizing behaviour was only relevant in inpatient treatment. High suppression might be detrimental to psychotherapy outcome and should be assessed early on. Further research should investigate the influence of suppression on the mechanisms that facilitate change in psychotherapy.

  11. Effect of quenched disorder on charge-orbital-spin ordering in single-layer manganites

    International Nuclear Information System (INIS)

    Uchida, Masaya; Mathieu, Roland; He, Jinping; Kaneko, Yoshio; Tokura, Yoshinori; Asamitsu, Atsushi; Kumai, Reiji; Tomioka, Yasuhide; Matsui, Yoshio

    2006-01-01

    Structural and magnetic properties have been investigated for half-doped single-layer manganites RE 0.5 Sr 1.5 MnO 4 [RE=La, (La, Pr), Pr, Nd, Sm, and Eu]. Analyses of electron diffraction and ac susceptibility measurements have revealed that the long-range charge-orbital ordering (CO-OO) state as observed in La 0.5 Sr 1.5 MnO 4 is suppressed for the other materials: the CO-OO transition temperature, as well as the correlation length decreases with a decrease in the cation size of RE. Such a short-range CO-OO state shows a spin-glass behavior at low temperatures. A new electronic phase diagram is established with quenched disorder as the control parameter. (author)

  12. Hexatically ordered superfluids

    NARCIS (Netherlands)

    Mullen, K.; Stoof, H.T.C.; Wallin, M.; Girvin, S.M.

    1994-01-01

    We develop a theory for a novel state of 4He films that possesses off-diagonal order (as in the superfluid state) as well as hexatic or bond orientational order. Within our description, both the hexatic and superfluid transitions are still on the Kosterlitz-Thouless type, but the superfluid

  13. Redefining solubility parameters: the partial solvation parameters.

    Science.gov (United States)

    Panayiotou, Costas

    2012-03-21

    The present work reconsiders a classical and universally accepted concept of physical chemistry, the solubility parameter. Based on the insight derived from modern quantum chemical calculations, a new definition of solubility parameter is proposed, which overcomes some of the inherent restrictions of the original definition and expands its range of applications. The original single solubility parameter is replaced by four partial solvation parameters reflecting the dispersion, the polar, the acidic and the basic character of the chemical compounds as expressed either in their pure state or in mixtures. Simple rules are adopted for the definition and calculation of these four parameters and their values are tabulated for a variety of common substances. In contrast, however, to the well known Hansen solubility parameters, their design and evaluation does not rely exclusively on the basic rule of "similarity matching" for solubility but it makes also use of the other basic rule of compatibility, namely, the rule of "complementarity matching". This complementarity matching becomes particularly operational with the sound definition of the acidic and basic components of the solvation parameter based on the third σ-moments of the screening charge distributions of the quantum mechanics-based COSMO-RS theory. The new definitions are made in a simple and straightforward manner, thus, preserving the strength and appeal of solubility parameter stemming from its simplicity. The new predictive method has been applied to a variety of solubility data for systems of pharmaceuticals and polymers. The results from quantum mechanics calculations are critically compared with the results from Abraham's acid/base descriptors.

  14. Determining Reduced Order Models for Optimal Stochastic Reduced Order Models

    Energy Technology Data Exchange (ETDEWEB)

    Bonney, Matthew S. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Brake, Matthew R.W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-08-01

    The use of parameterized reduced order models(PROMs) within the stochastic reduced order model (SROM) framework is a logical progression for both methods. In this report, five different parameterized reduced order models are selected and critiqued against the other models along with truth model for the example of the Brake-Reuss beam. The models are: a Taylor series using finite difference, a proper orthogonal decomposition of the the output, a Craig-Bampton representation of the model, a method that uses Hyper-Dual numbers to determine the sensitivities, and a Meta-Model method that uses the Hyper-Dual results and constructs a polynomial curve to better represent the output data. The methods are compared against a parameter sweep and a distribution propagation where the first four statistical moments are used as a comparison. Each method produces very accurate results with the Craig-Bampton reduction having the least accurate results. The models are also compared based on time requirements for the evaluation of each model where the Meta- Model requires the least amount of time for computation by a significant amount. Each of the five models provided accurate results in a reasonable time frame. The determination of which model to use is dependent on the availability of the high-fidelity model and how many evaluations can be performed. Analysis of the output distribution is examined by using a large Monte-Carlo simulation along with a reduced simulation using Latin Hypercube and the stochastic reduced order model sampling technique. Both techniques produced accurate results. The stochastic reduced order modeling technique produced less error when compared to an exhaustive sampling for the majority of methods.

  15. Suppression of interference noise caused by Fresnel reflection in all-fiber white-light interferometer.

    Science.gov (United States)

    Yuan, Yonggui; Cheng, Yongqing; Yang, Jun; Zhang, Haoliang; Lu, Dongchuan; Lv, Yan; Peng, Feng; Li, Hanyang; Zhang, Xiaojun; Jiang, Fuqiang; Yuan, Libo

    2017-11-01

    We propose methods to suppress the interference noise (IN) of an all-fiber white-light interferometer (WLI), which is caused by the residual Fresnel reflective beam. The methods are proposed to ensure a wide dynamic range and enhance the accuracy of measurement. IN can cause misjudgment of the realistic optical characteristic parameters, such as the fault diagnosis and polarization coupling of the optical devices under test. In addition, IN can reduce the dynamic range of the WLI. The optical path mismatch (OPM) method and the intensity suppression (IS) method by changing the positions and intensity of the IN are presented. The two suppression methods can successfully restrain IN caused by the Fresnel reflection beams. The experimental results show that IN is successfully suppressed by the OPM method or restrained by IS method in interferograms, and the dynamic range can achieve 85 dB without IN.

  16. Narcissism and birth order.

    Science.gov (United States)

    Eyring, W E; Sobelman, S

    1996-04-01

    The purpose of this investigation was to clarify the relationship between birth-order position and the development of narcissism, while refining research and theory. The relationship between birth-order status and narcissism was examined with a sample of 79 undergraduate students (55 women and 24 men). These subjects were placed in one of the four following birth-order categories of firstborn, second-born, last-born, and only children. These categories were chosen given their significance in Adlerian theory. Each subject completed the Narcissistic Personality Inventory and a demographic inventory. Based on psychodynamic theory, it was hypothesized that firstborn children were expected to score highest, but statistical significance was not found for an association between narcissism and birth order. Further research is urged to investigate personality theory as it relates to parenting style and birth order.

  17. Put order picking system

    Directory of Open Access Journals (Sweden)

    Đurđević Dragan D.

    2014-01-01

    Full Text Available Nowadays the warehouse is very important logistic component of the supply chain, where order-picking systems have important role. Due to the significant impact on logistics performance permanent goals are to increase efficiency and reduce the cost of these systems. To achieve these goals, there are different researches, and their success is determined by the achieved performances. Performances order picking process are dependent on the applied technology concepts of order-picking system, as well as the ways in which it is organized and managed. In addition to the standard conceptions (the man to good and good to the man is one of the newer, so-called. 'put' system - the inverse order-picking. The aim of this paper is to describe this concept, point out its core strengths and weaknesses and provide a basis that may be of importance in the development of warehouse technological solutions and application of this order-picking systems concept.

  18. SUSY Parameter Measurements with Fittino

    Energy Technology Data Exchange (ETDEWEB)

    Bechtle, P.; /SLAC; Desch, K.; Wienemann, P.; /Freiburg U.

    2005-12-14

    This article presents the results of a realistic global fit of the Lagrangian parameters of the Minimal Supersymmetric Standard Model with no assumptions on the SUSY breaking mechanism using the fit program Fittino. The fit is performed using the precision of future mass measurements of superpartners at the LHC and mass and polarized topological cross-section measurements at the ILC. Higher order radiative corrections are accounted for wherever possible to date. Results are obtained for a modified SPS1a MSSM benchmark scenario (general MSSM without assumptions on the breaking mechanism) and for a specific mSUGRA scenario. Exploiting a simulated annealing algorithm, a stable result is obtained without any a priori assumptions on the fit parameters. Most of the Lagrangian parameters can be extracted at the percent level or better if theoretical uncertainties are neglected. Neither LHC nor ILC measurements alone will be sufficient to obtain a stable result.

  19. Burst suppression probability algorithms: state-space methods for tracking EEG burst suppression

    Science.gov (United States)

    Chemali, Jessica; Ching, ShiNung; Purdon, Patrick L.; Solt, Ken; Brown, Emery N.

    2013-10-01

    Objective. Burst suppression is an electroencephalogram pattern in which bursts of electrical activity alternate with an isoelectric state. This pattern is commonly seen in states of severely reduced brain activity such as profound general anesthesia, anoxic brain injuries, hypothermia and certain developmental disorders. Devising accurate, reliable ways to quantify burst suppression is an important clinical and research problem. Although thresholding and segmentation algorithms readily identify burst suppression periods, analysis algorithms require long intervals of data to characterize burst suppression at a given time and provide no framework for statistical inference. Approach. We introduce the concept of the burst suppression probability (BSP) to define the brain's instantaneous propensity of being in the suppressed state. To conduct dynamic analyses of burst suppression we propose a state-space model in which the observation process is a binomial model and the state equation is a Gaussian random walk. We estimate the model using an approximate expectation maximization algorithm and illustrate its application in the analysis of rodent burst suppression recordings under general anesthesia and a patient during induction of controlled hypothermia. Main result. The BSP algorithms track burst suppression on a second-to-second time scale, and make possible formal statistical comparisons of burst suppression at different times. Significance. The state-space approach suggests a principled and informative way to analyze burst suppression that can be used to monitor, and eventually to control, the brain states of patients in the operating room and in the intensive care unit.

  20. Analysis of optical vortices with suppressed sidelobes using modified Bessel-like function and trapezoid annulus modulation structures.

    Science.gov (United States)

    Guo, Jian; Wei, Zhongchao; Liu, Yuebo; Huang, Aili

    2015-02-01

    Two amplitude modulation methods, including modified Bessel-like function modulation structure and trapezoid annulus structure, for suppressing sidelobes of optical vortices are studied. In the former approach, we propose that the order of the Bessel-like function can be an additional parameter to modulate diffraction patterns of optical vortices motivated by the idea of conventional annulus structures. Furthermore, new Bessel-like modulation functions are introduced to solve the problem of low diffraction efficiency of the original one. Trapezoid annulus structure is proposed as a compromise structure between the modified Bessel-like modulation structure and the conventional annulus one, and has advantages of both. It is demonstrated that these two approaches can achieve high-quality optical vortices with suppressed sidelobes effectively, and the relative structures behave as more flexible and applicable structures for producing optical vortices with large coverage of topological charges, which suggests great potential in simplifying the structure designing procedure. These reliable and generalized structures for generating high-quality optical vortices will help to promote the development of future optical communication and optical manipulation significantly.

  1. Suppression of the primary immune response in rainbow trout, Salmo gairdneri, sublethally exposed to tritiated water during embryogenesis

    International Nuclear Information System (INIS)

    Strand, J.A.

    1975-01-01

    Antibody synthesis in response to vaccination with a 0.1 cc (1.8 x 10 8 cells/cc) intraperitoneally injected heat-killed strain of Flexibacter columnaris was employed to investigate the effect of tritium irradiation (0, 0.04, 0.4, 4.0 and 40.0 rads total dose for 20 days during embryogenesis) on development of the primary immune response in 5-month rainbow trout, Salmo gairdneri. Total serum protein measurements and electrophoretic separation of blood serum proteins followed by densitometric analyses were performed to assess the potential for qualitative and quantitative changes in blood serum components which conceivably accounted for suppressed immune responsiveness in tritium-irradiated fish. Data on the biological effects of tritium on early life stages in terms of hatchability, abnormality, latent mortality, and growth were also collected. A review of all experiments directed at determining the effects of early radiation exposure on the parameters of hatchability, incidence of abnormality, latent mortality and depressed growth, revealed considerable variation among similar treatments and indicated that significant effects at dose levels of 50 rads and below were not consistently demonstrated. While present experimental results demonstrated that the primary immune response in juvenile rainbow trout was significantly suppressed following embryonic exposure to tritium at essentially the 1.0 μCi/ml level, and perhaps at the 0.1 μCi/ml level, these concentrations are no less than 5 to 6 orders of magnitude above present levels for tritium in the aquatic environment

  2. Psychopathology and Thought Suppression: A Quantitative Review

    Science.gov (United States)

    Magee, Joshua C.; Harden, K. Paige; Teachman, Bethany A.

    2012-01-01

    Recent theories of psychopathology have suggested that thought suppression intensifies the persistence of intrusive thoughts, and proposed that difficulty with thought suppression may differ between groups with and without psychopathology. The current meta-analytic review evaluates empirical evidence for difficulty with thought suppression as a function of the presence and specific type of psychopathology. Based on theoretical proposals from the psychopathology literature, diagnosed and analogue samples were expected to show greater recurrence of intrusive thoughts during thought suppression attempts than non-clinical samples. However, results showed no overall differences in the recurrence of thoughts due to thought suppression between groups with and without psychopathology. There was, nevertheless, variation in the recurrence of thoughts across different forms of psychopathology, including relatively less recurrence during thought suppression for samples with symptoms of Obsessive-Compulsive Disorder, compared to non-clinical samples. However, these differences were typically small and provided only mixed support for existing theories. Implications for cognitive theories of intrusive thoughts are discussed, including proposed mechanisms underlying thought suppression. PMID:22388007

  3. Order of blood draw

    DEFF Research Database (Denmark)

    Cornes, Michael; van Dongen-Lases, Edmée; Grankvist, Kjell

    2017-01-01

    Medicine Working Group for the Preanalytical Phase (EFLM WG-PRE) provides an overview and summary of the literature with regards to order of draw in venous blood collection. Given the evidence presented in this article, the EFLM WG-PRE herein concludes that a significant frequency of sample contamination......, CLSI) guidelines recommend that the order of draw of blood during phlebotomy should be blood culture/sterile tubes, then plain tubes/gel tubes, then tubes containing additives. This prevents contamination of sample tubes with additives from previous tubes that could cause erroneous results. There have...... does occur if order of draw is not followed during blood collection and when performing venipuncture under less than ideal circumstances, thus putting patient safety at risk. Moreover, given that order of draw is not difficult to follow and knowing that ideal phlebotomy conditions and protocols...

  4. Mathematics of aperiodic order

    CERN Document Server

    Lenz, Daniel; Savinien, Jean

    2015-01-01

    What is order that is not based on simple repetition, that is, periodicity? How must atoms be arranged in a material so that it diffracts like a quasicrystal? How can we describe aperiodically ordered systems mathematically? Originally triggered by the – later Nobel prize-winning – discovery of quasicrystals, the investigation of aperiodic order has since become a well-established and rapidly evolving field of mathematical research with close ties to a surprising variety of branches of mathematics and physics. This book offers an overview of the state of the art in the field of aperiodic order, presented in carefully selected authoritative surveys. It is intended for non-experts with a general background in mathematics, theoretical physics or computer science, and offers a highly accessible source of first-hand information for all those interested in this rich and exciting field. Topics covered include the mathematical theory of diffraction, the dynamical systems of tilings or Delone sets, their cohomolog...

  5. Ordered groups and topology

    CERN Document Server

    Clay, Adam

    2016-01-01

    This book deals with the connections between topology and ordered groups. It begins with a self-contained introduction to orderable groups and from there explores the interactions between orderability and objects in low-dimensional topology, such as knot theory, braid groups, and 3-manifolds, as well as groups of homeomorphisms and other topological structures. The book also addresses recent applications of orderability in the studies of codimension-one foliations and Heegaard-Floer homology. The use of topological methods in proving algebraic results is another feature of the book. The book was written to serve both as a textbook for graduate students, containing many exercises, and as a reference for researchers in topology, algebra, and dynamical systems. A basic background in group theory and topology is the only prerequisite for the reader.

  6. Operator ordering and causality

    OpenAIRE

    Plimak, L. I.; Stenholm, S. T.

    2011-01-01

    It is shown that causality violations [M. de Haan, Physica 132A, 375, 397 (1985)], emerging when the conventional definition of the time-normal operator ordering [P.L.Kelley and W.H.Kleiner, Phys.Rev. 136, A316 (1964)] is taken outside the rotating wave approximation, disappear when the amended definition [L.P. and S.S., Annals of Physics, 323, 1989 (2008)] of this ordering is used.

  7. Measuring the chargino parameters

    Indian Academy of Sciences (India)

    Enlarging the spectrum of physical states together with the necessity of including the. SUSY breaking terms gives rise to a large number of parameters. Even in the minimal supersymmetric model (MSSM) more than 100 new parameters are introduced! This number of parameters, reflecting our ignorance of SUSY breaking ...

  8. Overcoming evolved resistance to population-suppressing homing-based gene drives.

    Science.gov (United States)

    Marshall, John M; Buchman, Anna; Sánchez C, Héctor M; Akbari, Omar S

    2017-06-19

    The recent development of a CRISPR-Cas9-based homing system for the suppression of Anopheles gambiae is encouraging; however, with current designs, the slow emergence of homing-resistant alleles is expected to result in suppressed populations rapidly rebounding, as homing-resistant alleles have a significant fitness advantage over functional, population-suppressing homing alleles. To explore this concern, we develop a mathematical model to estimate tolerable rates of homing-resistant allele generation to suppress a wild population of a given size. Our results suggest that, to achieve meaningful population suppression, tolerable rates of resistance allele generation are orders of magnitude smaller than those observed for current designs for CRISPR-Cas9-based homing systems. To remedy this, we theoretically explore a homing system architecture in which guide RNAs (gRNAs) are multiplexed, increasing the effective homing rate and decreasing the effective resistant allele generation rate. Modeling results suggest that the size of the population that can be suppressed increases exponentially with the number of multiplexed gRNAs and that, with four multiplexed gRNAs, a mosquito species could potentially be suppressed on a continental scale. We also demonstrate successful proof-of-principle use of multiplexed ribozyme flanked gRNAs to induce mutations in vivo in Drosophila melanogaster - a strategy that could readily be adapted to engineer stable, homing-based drives in relevant organisms.

  9. Ecological and Economic Importance of Bats (Order Chiroptera)

    OpenAIRE

    Kasso, Mohammed; Balakrishnan, Mundanthra

    2013-01-01

    Order Chiroptera is the second most diverse and abundant order of mammals with great physiological and ecological diversity. They play important ecological roles as prey and predator, arthropod suppression, seed dispersal, pollination, material and nutrient distribution, and recycle. They have great advantage and disadvantage in economic terms. The economic benefits obtained from bats include biological pest control, plant pollination, seed dispersal, guano mining, bush meat and medicine, aes...

  10. Suppression of auger recombination in ""giant"" core/shell nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Santamaria, Florencio [Los Alamos National Laboratory; Vela, Javier [Los Alamos National Laboratory; Schaller, Richard D [Los Alamos National Laboratory; Hollingsworth, Jennifer A [Los Alamos National Laboratory; Klimov, Victor I [Los Alamos National Laboratory; Chen, Yongfen [NON LANL

    2009-01-01

    Many potential applications of semiconductor nanocrystals are hindered by nonradiative Auger recombination wherein the electron-hole (exciton) recombination energy is transferred to a third charge carrier. This process severely limits the lifetime and bandwidth of optical gain, leads to large nonradiative losses in light emitting diodes and photovoltaic cells, and is believed to be responsible for intermittency ('blinking') of emission from single nanocrystals. The development of nanostructures in which Auger recombination is suppressed has been a longstanding goal in colloidal nanocrystal research. Here, we demonstrate that such suppression is possible using so-called 'giant' nanocrystals that consist of a small CdSe core and a thick CdS shell. These nanostructures exhibit a very long biexciton lifetime ({approx}10 ns) that is likely dominated by radiative decay instead of non-radiative Auger recombination. As a result of suppressed Auger recombination, even high-order multiexcitons exhibit high emission efficiencies, which allows us to demonstrate optical amplification with an extraordinarily large bandwidth (>500 me V) and record low excitation thresholds.

  11. Decoupled Hierarchical Structures for Suppression of Leidenfrost Phenomenon.

    Science.gov (United States)

    Farokhnia, Nazanin; Sajadi, Seyed Mohammad; Irajizad, Peyman; Ghasemi, Hadi

    2017-03-14

    Thermal management of high temperature systems through cooling droplets is limited by the existence of the Leidenfrost point (LFP), at which the formation of a continuous vapor film between a hot solid and a cooling droplet diminishes the heat transfer rate. This limit results in a bottleneck for the advancement of the wide spectrum of systems including high-temperature power generation, electronics/photonics, reactors, and spacecraft. Despite a long time effort on development of surfaces for suppression of this phenomenon, this limit has only shifted to higher temperatures, but still exists. Here, we report a new multiscale decoupled hierarchical structure that suppress the Leidenfrost state and provide efficient heat dissipation at high temperatures. The architecture of these structures is composed of a nanomembrane assembled on top of a deep micropillar structure. This architecture allows to independently tune the involved forces and to suppress LFP. Once a cooling droplet contacts these surfaces, by rerouting the path of vapor flow, the cooling droplet remains attached to the hot solid substrates even at high temperatures (up to 570 °C) for heat dissipation with no existence of Leidenfrost phenomenon. These new surfaces offer unprecedented heat dissipation capacity at high temperatures (2 orders of magnitude higher than the other state-of-the-art surfaces). We envision that these surfaces open a new avenue in thermal management of high-temperature systems through spray cooling.

  12. Parameter screening: the use of a dummy parameter to identify non-influential parameters in a global sensitivity analysis

    Science.gov (United States)

    Khorashadi Zadeh, Farkhondeh; Nossent, Jiri; van Griensven, Ann; Bauwens, Willy

    2017-04-01

    Parameter estimation is a major concern in hydrological modeling, which may limit the use of complex simulators with a large number of parameters. To support the selection of parameters to include in or exclude from the calibration process, Global Sensitivity Analysis (GSA) is widely applied in modeling practices. Based on the results of GSA, the influential and the non-influential parameters are identified (i.e. parameters screening). Nevertheless, the choice of the screening threshold below which parameters are considered non-influential is a critical issue, which has recently received more attention in GSA literature. In theory, the sensitivity index of a non-influential parameter has a value of zero. However, since numerical approximations, rather than analytical solutions, are utilized in GSA methods to calculate the sensitivity indices, small but non-zero indices may be obtained for the indices of non-influential parameters. In order to assess the threshold that identifies non-influential parameters in GSA methods, we propose to calculate the sensitivity index of a "dummy parameter". This dummy parameter has no influence on the model output, but will have a non-zero sensitivity index, representing the error due to the numerical approximation. Hence, the parameters whose indices are above the sensitivity index of the dummy parameter can be classified as influential, whereas the parameters whose indices are below this index are within the range of the numerical error and should be considered as non-influential. To demonstrated the effectiveness of the proposed "dummy parameter approach", 26 parameters of a Soil and Water Assessment Tool (SWAT) model are selected to be analyzed and screened, using the variance-based Sobol' and moment-independent PAWN methods. The sensitivity index of the dummy parameter is calculated from sampled data, without changing the model equations. Moreover, the calculation does not even require additional model evaluations for the Sobol

  13. XY model with higher-order exchange.

    Science.gov (United States)

    Žukovič, Milan; Kalagov, Georgii

    2017-08-01

    An XY model, generalized by inclusion of up to an infinite number of higher-order pairwise interactions with an exponentially decreasing strength, is studied by spin-wave theory and Monte Carlo simulations. At low temperatures the model displays a quasi-long-range-order phase characterized by an algebraically decaying correlation function with the exponent η=T/[2πJ(p,α)], nonlinearly dependent on the parameters p and α that control the number of the higher-order terms and the decay rate of their intensity, respectively. At higher temperatures the system shows a crossover from the continuous Berezinskii-Kosterlitz-Thouless to the first-order transition for the parameter values corresponding to a highly nonlinear shape of the potential well. The role of topological excitations (vortices) in changing the nature of the transition is discussed.

  14. Attention modulates sensory suppression during back movements.

    Science.gov (United States)

    Van Hulle, Lore; Juravle, Georgiana; Spence, Charles; Crombez, Geert; Van Damme, Stefaan

    2013-06-01

    Tactile perception is often impaired during movement. The present study investigated whether such sensory suppression also occurs during back movements, and whether this would be modulated by attention. In two tactile detection experiments, participants simultaneously engaged in a movement task, in which they executed a back-bending movement, and a perceptual task, consisting of the detection of subtle tactile stimuli administered to their upper or lower back. The focus of participants' attention was manipulated by raising the probability that one of the back locations would be stimulated. The results revealed that tactile detection was suppressed during the execution of the back movements. Furthermore, the results of Experiment 2 revealed that when the stimulus was always presented to the attended location, tactile suppression was substantially reduced, suggesting that sensory suppression can be modulated by top-down attentional processes. The potential of this paradigm for studying tactile information processing in clinical populations is discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Combustion suppressing device for leaked sodium

    International Nuclear Information System (INIS)

    Ooto, Akihiro.

    1985-01-01

    Purpose: To suppress the atmospheric temperature to secure the building safety and shorten the recovery time after the leakage in a chamber for containing sodium leaked from coolant circuit equipments or pipeways of LMFBR type rector by suppressing the combustion of sodium contained in the chamber. Constitution: To the inner wall of a chamber for containing sodium handling equipments, are vertically disposed a panel having a coolant supply port at the upper portion and a coolant discharge port at the lower portion thereof and defined with a coolant flowing channel and a panel for sucking the coolant discharged from the abovementioned panel and exhausting the same externally. Further, a corrugated combustion suppressing plate having apertures for draining the condensated leaked sodium is disposed near the sodium handling equipments. If ruptures are resulted to the sodium handling equipments or pipeway, leaked sodium is passed through the drain apertures in the suppressing plate and stored at the bottom of the containing chamber. (Horiuchi, T.)

  16. A reappraisal of the concept of suppressive versus remittive psoriasis treatments.

    Science.gov (United States)

    Feldman, Steven R; Lucas, Jennifer; Pearce, Daniel J

    2005-08-01

    Among the ways to characterize the many treatments for psoriasis is to distinguish suppressive from remittive therapies. Remittive therapies are thought to be treatments that result in a prolonged period of disease remission even after stopping the drug, while suppressive treatments are thought to work only during the treatment period. However, apparent differences in remittive and suppressive properties may be due to the remitting and relapsing nature of psoriasis and the order in which treatments are used in patients. Few clinical trials have compared the suppressive versus remittive properties of different treatments. Given the adverse events and expense associated with many psoriasis therapies, a major implication is that psoriasis patients who have cleared on therapy should probably be tested at intervals to see if they can be tapered off their medication without loss of control of their disease.

  17. Universality of ordering dynamics in conserved multicomponent systems

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Mouritsen, Ole G.

    1993-01-01

    lattices and the evolving order is studied via the excess energy, the domain-size distribution function, and the density of isolated diffusing particles, which facilitate the coarsening process. The growth law that describes the time-evolution of the linear length scale, R (t), of the ordered domains......A comparative study is performed of the ordering dynamics and spinodal decomposition processes in two-dimensional two-state and three-state ferromagnetic Potts models with conserved order parameter. The models are investigated by Monte Carlo quenching simulations on both square and triangular...... to the case of nonconserved order parameter, there is a single universality class describing the cases of conserved order parameter independent of the number of components of the order parameter. In the asymptotic regime, the topological difference in the domain-boundary network between the vertex-free two...

  18. A Computer Model of Saccadic Suppression.

    Science.gov (United States)

    1981-01-01

    Implications of sustained and transient channels for theories of visul pattern masking, saccadic suppression, and information processing...suppression. Because information available to the retina during saccades is a dynamic event in space and in time, the spatio-temporal properties of the...t), use is made of the convolution integral: In the context of the model, g(x,t) is the information supplied to a psychophysical detector and f(x,t

  19. Suppression mental questionnaire: a preliminary study

    OpenAIRE

    Salvatore Settineri; Emanuele Maria Merlo; Irene Pagano Dritto; Maria Midili; Antonio Bruno; Carmela Mento

    2016-01-01

    Authors postulate that the difference between suppression and repression, highlighted in particular by the Societè Psychanalitique de Paris, enables the development of a quantitative instrument, since suppression is a defense accessible to consciousness and therefore quantifiable like scales and questionnaires. The idea of constructing a questionnaire, included the identification of thirty variables having somehow a plausible relationship with this mechanism. The factor exploratory analysis w...

  20. Suppressing Tsetse Flies to Improve Lives

    International Nuclear Information System (INIS)

    Potterton, Louise; Pavlicek, Petr; Parker, Andrew

    2013-01-01

    In 2009, the government-run Southern Tsetse Eradication Project (STEP) in Ethiopia, with the support of the IAEA, started to carry out intensive activities to suppress the fly population using insecticides. The fly population is now down by 90%. The benefits of tsetse suppression can be seen all over the region. Diary produce is now widely available at markets and healthy animals can be seen everywhere in farming and transport

  1. Focusing properties of hard x-ray photon sieves: three-parameter apodization window and waveguide effect.

    Science.gov (United States)

    Xie, Changqing; Zhu, Xiaoli; Jia, Jia

    2009-10-01

    In this Letter, a three-parameter modified Kaiser apodization window is used to modulate the pinhole density on each ring of hard x-ray photon sieves, analyzing the guided-wave propagation inside the photon sieves' nanostructure. Theoretical analysis reveals that the waveguide effect can suppress the emergence of the high-order diffraction effect; the additional parameter of the modified Kaiser window function gives rise to new degrees of freedom for manipulating the FWHM and signal-to-noise ratio. Metal nanostructure thickness has no influence on the FWHM. Hard x-ray photon sieves with 90 degrees phase shift (not 180 degrees phase shift) can provide the best signal-to-noise ratio, which relaxes the nanofabrication constraints somewhat. Our work provides a robust way to design hard x-ray photon sieves.

  2. Taste mixture interactions: suppression, additivity, and the predominance of sweetness.

    Science.gov (United States)

    Green, Barry G; Lim, Juyun; Osterhoff, Floor; Blacher, Karen; Nachtigal, Danielle

    2010-12-02

    Most of what is known about taste interactions has come from studies of binary mixtures. The primary goal of this study was to determine whether asymmetries in suppression between stimuli in binary mixtures predict the perception of tastes in more complex mixtures (e.g., ternary and quaternary mixtures). Also of interest was the longstanding question of whether overall taste intensity derives from the sum of the tastes perceived within a mixture (perceptual additivity) or from the sum of the perceived intensities of the individual stimuli (stimulus additivity). Using the general labeled magnitude scale together with a sip-and-spit procedure, we asked subjects to rate overall taste intensity and the sweetness, sourness, saltiness and bitterness of approximately equi-intense sucrose, NaCl, citric acid and QSO(4) stimuli presented alone and in all possible binary, ternary and quaternary mixtures. The results showed a consistent pattern of mixture suppression in which sucrose sweetness tended to be both the least suppressed quality and the strongest suppressor of other tastes. The overall intensity of mixtures was found to be predicted best by perceptual additivity. A second experiment that was designed to rule out potentially confounding effects of the order of taste ratings and the temperature of taste solutions replicated the main findings of the first experiment. Overall, the results imply that mixture suppression favors perception of sweet carbohydrates in foods at the expense of other potentially harmful ingredients, such as high levels of sodium (saltiness) and potential poisons or spoilage (bitterness and sourness). Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Pressure suppression chamber for a reactor container

    International Nuclear Information System (INIS)

    Kato, Masami

    1980-01-01

    Purpose: To improve the safety of a pressure suppression device by floating shock absorbers on the surface of pressure suppression pool water in a pressure suppression chamber opposing to vent headers of a reactor container. Constitution: Vent pipes of a reactor container are provided with vent headers, vacuum valves which are actuated upon excessively high pressure resulted in the space of a pressure suppression chamber, and downcomers for supplying water, vapor, etc. from the container to the pressure suppression pool. Shock absorbers are floated on the surface of pool water opposing to the headers. Accordingly, if gaseous nitrogen or air sealed in the container is compressed upon loss of coolant accidents to rapidly form gas bubbles in the pool and thereby generate impact pressure to the pool water, the pressure are absorbed by the shock absorbers and not transmitted directly to the vent pies or headers, whereby the improved stability can be attained for the pressure suppression device of the reactor container. (Seki, T.)

  4. Suppression sours sacrifice: emotional and relational costs of suppressing emotions in romantic relationships.

    Science.gov (United States)

    Impett, Emily A; Kogan, Aleksandr; English, Tammy; John, Oliver; Oveis, Christopher; Gordon, Amie M; Keltner, Dacher

    2012-06-01

    What happens when people suppress their emotions when they sacrifice for a romantic partner? This multimethod study investigates how suppressing emotions during sacrifice shapes affective and relationship outcomes. In Part 1, dating couples came into the laboratory to discuss important romantic relationship sacrifices. Suppressing emotions was associated with emotional costs for the partner discussing his or her sacrifice. In Part 2, couples participated in a 14-day daily experience study. Within-person increases in emotional suppression during daily sacrifice were associated with decreases in emotional well-being and relationship quality as reported by both members of romantic dyads. In Part 3, suppression predicted decreases in relationship satisfaction and increases in thoughts about breaking up with a romantic partner 3 months later. In the first two parts of the study, authenticity mediated the costly effects of suppression. Implications for research on close relationships and emotion regulation are discussed.

  5. Nuclear order in copper

    DEFF Research Database (Denmark)

    Annila, A.J.; Clausen, K.N.; Lindgård, P-A.

    1990-01-01

    A new ordering vector k=(2π/a)(0, 2/3, 2/3) for fcc antiferromagnets has been found by neutron-diffraction experiments at nanokelvin temperatures in the nuclear-spin system of a 65Cu single crystal. The corresponding reflection together with the previously observed (100) Bragg peak show the prese......A new ordering vector k=(2π/a)(0, 2/3, 2/3) for fcc antiferromagnets has been found by neutron-diffraction experiments at nanokelvin temperatures in the nuclear-spin system of a 65Cu single crystal. The corresponding reflection together with the previously observed (100) Bragg peak show...

  6. Birth Order Debate Resolved?

    Science.gov (United States)

    Zajonc, R. B.

    2001-01-01

    Critiques Rodgers et al.'s June 2000 research on the relation between birth order and intelligence, which suggests that it is a methodological illusion. Explains how the intellectual environment and the teaching function (whereby older children tutor younger ones) contribute to the growth of intellectual maturity, the first negatively and the…

  7. The Ordered Apology

    NARCIS (Netherlands)

    van Dijck, Gijs

    2017-01-01

    Psychological research has demonstrated that an apology can contribute to the well-being of the receiver of the apology. However, the legal community has only cautiously embraced the idea of claiming and ordering apologies in a legal procedure. The conventional wisdom is that apologies that are

  8. Education and World Order

    Science.gov (United States)

    Jones, Phillip W.

    2007-01-01

    The impact on educational analysis of mainstream international relations (IR) theories is yet to realize its full potential. The problem of education in relation to the construction of world order is considered in relation to core developments in IR theory since the Second World War. In particular, the global architecture of education is seen as a…

  9. Third order trace formula

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 123; Issue 4. Third Order Trace Formula. Arup Chattopadhyay Kalyan B Sinha. Volume 123 Issue 4 November 2013 pp 547-575. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/pmsc/123/04/0547-0575 ...

  10. Order Management - Today's focus

    DEFF Research Database (Denmark)

    Barfod, Ari

    1996-01-01

    -production, purchases, and financing.Often, no one single function or department is responsible for the handling and completion of the individual customer orders, and the information systems in use are frequently not too well-functioning. Finally, too much time is used for handling acticities that do not add value...

  11. Even order snake resonances

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1993-01-01

    We found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We also found that even order snake resonances exist in the overlapping intrinsic and imperfection resonances. Due to the perturbed spin tune shift of imperfection resonances, each snake resonance splits into two

  12. Higher-Order Hierarchies

    DEFF Research Database (Denmark)

    Ernst, Erik

    2003-01-01

    This paper introduces the notion of higher-order inheritance hierarchies. They are useful because they provide well-known benefits of object-orientation at the level of entire hierarchies-benefits which are not available with current approaches. Three facets must be adressed: First, it must be po...

  13. The 'final order' problem

    NARCIS (Netherlands)

    Teunter, RH; Haneveld, WKK

    1998-01-01

    When the service department of a company selling machines stops producing and supplying spare parts for certain machines, customers are offered an opportunity to place a so-called final order for these spare parts. We focus on one customer with one machine. The customer plans to use this machine up

  14. Reshaping the International Order

    NARCIS (Netherlands)

    J. Tinbergen (Jan)

    1976-01-01

    textabstractIn October the third report to the Club of Rome was published under the title Reshaping the International Order (RIO).1 It was formulated by a group of about twenty experts from developing as well as developed countries, including one from Romania. The initiative to undertake this study

  15. Partially ordered models

    NARCIS (Netherlands)

    Fernandez, R.; Deveaux, V.

    2010-01-01

    We provide a formal definition and study the basic properties of partially ordered chains (POC). These systems were proposed to model textures in image processing and to represent independence relations between random variables in statistics (in the later case they are known as Bayesian networks).

  16. 'Good Order and Police'

    DEFF Research Database (Denmark)

    Mührmann-Lund, Jørgen

    2016-01-01

    The emergence of police ordinances and police authorities in the early modern period has traditionally been seen as a way to discipline society in order to increase the power of the absolutist state. However, recent investigations of early modern policing in German and French regions show...

  17. The genus Mustelus (Family Triakidae, Order Carcharhiniformes ...

    African Journals Online (AJOL)

    spamer

    The genus Mustelus (Family Triakidae, Order. Carcharhiniformes), commonly called .... suitable for sharks with a well-defined length-at-birth. (L0). This eliminates the .... Table I: Parameter estimates using Fabens' method and standard errors (SE) and 95% confidence intervals (CI) for the Von. Bertalanffy growth model fitted ...

  18. Gravitational clustering to all perturbative orders

    International Nuclear Information System (INIS)

    Abdalla, E.; Mohayaee, R.

    1999-04-01

    We derive the time evolution of the density contrast to all orders of perturbation theory, by solving the Einstein equation for scale-invariant fluctuations. These fluctuations are represented by an infinite series in inverse powers of the radial parameter. In addition to the standard growing modes, we find infinitely many more new growing modes for open and closed universes. (author)

  19. Identifying product order with restricted Boltzmann machines

    Science.gov (United States)

    Rao, Wen-Jia; Li, Zhenyu; Zhu, Qiong; Luo, Mingxing; Wan, Xin

    2018-03-01

    Unsupervised machine learning via a restricted Boltzmann machine is a useful tool in distinguishing an ordered phase from a disordered phase. Here we study its application on the two-dimensional Ashkin-Teller model, which features a partially ordered product phase. We train the neural network with spin configuration data generated by Monte Carlo simulations and show that distinct features of the product phase can be learned from nonergodic samples resulting from symmetry breaking. Careful analysis of the weight matrices inspires us to define a nontrivial machine-learning motivated quantity of the product form, which resembles the conventional product order parameter.

  20. Subversion of plant cellular functions by bacterial type-III effectors: beyond suppression of immunity.

    Science.gov (United States)

    Macho, Alberto P

    2016-04-01

    Most bacterial plant pathogens employ a type-III secretion system to inject type-III effector (T3E) proteins directly inside plant cells. These T3Es manipulate host cellular processes in order to create a permissive niche for bacterial proliferation, allowing development of the disease. An important role of T3Es in plant pathogenic bacteria is the suppression of plant immune responses. However, in recent years, research has uncovered T3E functions different from direct immune suppression, including the modulation of plant hormone signaling, metabolism or organelle function. This insight article discusses T3E functions other than suppression of immunity, which may contribute to the modulation of plant cells in order to promote bacterial survival, nutrient release, and bacterial replication and dissemination. © 2015 The Author. New Phytologist © 2015 New Phytologist Trust.

  1. Are Limit Orders Rational?

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Martin

    2007-01-01

    Roč. 14, č. 4 (2007), s. 32-38 ISSN 0572-3043 R&D Projects: GA ČR(CZ) GA402/06/1417; GA ČR GA402/04/1294; GA ČR GD402/03/H057 Institutional research plan: CEZ:AV0Z10750506 Keywords : market microstructure * limit order market * portfolio selection Subject RIV: AH - Economics

  2. Ordered Mesoporous Nanomaterials

    Directory of Open Access Journals (Sweden)

    Eva Pellicer

    2014-12-01

    Full Text Available The Special Issue of Nanomaterials “Ordered Mesoporous Nanomaterials” covers novel synthetic aspects of mesoporous materials and explores their use in diverse areas like drug delivery, photocatalysis, filtration or electrocatalysis. The range of materials tackled includes metals and alloys, aluminosilicates, silica, alumina and transition metal oxides. The variety of materials, synthetic approaches and applications examined is vivid proof of the interest that mesoporous materials spark among researchers world-wide.[...

  3. Fauna Europaea - Orthopteroid orders.

    Science.gov (United States)

    Heller, Klaus-Gerhard; Bohn, Horst; Haas, Fabian; Willemse, Fer; de Jong, Yde

    2016-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant European terrestrial and freshwater animals, their geographical distribution at the level of countries and major islands (west of the Urals and excluding the Caucasus region), and some additional information. The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. The "Orthopteroid orders" is one of the 58 Fauna Europaea major taxonomic groups. It contains series of mostly well-known insect orders: Embiodea (webspinners), Dermaptera (earwigs), Phasmatodea (walking sticks), Orthoptera s.s. (grasshoppers, crickets, bush-crickets) and Dictyoptera with the suborders Mantodea (mantids), Blattaria (cockroaches) and Isoptera (termites). For the Orthopteroid orders, data from 35 families containing 1,371 species are included in this paper.

  4. Vibration suppression of a flywheel system using a novel nonlinear vibration absorber with an Euler buckled beam

    Science.gov (United States)

    Haiping, Liu; Wenhua, Shi

    2016-09-01

    The micro-vibration from flywheel system, as one of the main disturbances, has restricted the effective use of high sensitive payloads in satellites. In order to suppress the low- frequency line spectrum from the flywheel, a novel nonlinear vibration absorber (NVA) using Euler buckled beam is developed. The proposed NVA is attached on the supporting structure of the flywheel assembly, aiming to attenuate the line spectrum introduced by the flywheel in operation. A discrete multi-degree-of-freedom dynamic model, which includes the NVA, the flywheel and the supporting structure by taking into account of the gyroscopic effect of the flywheel, is built. The NVA is represented by a linear positive stiffness spring and parallel Euler buckled beams. The systematic dynamic equations with and without the NVA under the micro-vibration from the flywheel, respectively, are solved by using fourth-order Runge-Kutta method in time-domain. In addition, the effects of initial imperfection, oblique angle and damping coefficient of the Euler buckled beam on the vibration suppression performance are studied. The calculating results reveal that a typical nonlinear dynamic absorber for controlling the micro-vibration from the flywheel is constructed successfully based on the provided designing parameters of the Euler buckled beam. Compared with the vibration responses of the combined system with and without the NVA, it can be concluded that the NVA has better attenuation performance. The initial imperfection and damping coefficient of the Euler buckled beam exist optimum values, and with the increase of the oblique angle, the vibration controlling characteristics of the NVA have been improved.

  5. A method for pressure-pulse suppression in fluid-filled piping

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y.W.; Bielick, E.F. (Argonne National Lab., IL (USA)); Wiedermann, A.H. (IIT Research Inst., Chicago, IL (USA)); Ockert, C.E. (USDOE, Washington, DC (USA))

    1989-01-01

    A simple, nondestructive method to suppress pressure pulses in fluid-filled piping was proposed and theoretically analyzed earlier. In this paper, the proposed method is verified experimentally. The results of experiments performed for the range of parameters of practical importance indicated that the attenuation of pressure pulses was in accordance with the theoretical predictions. This paper describes the experimental setup and the test models of the proposed pulse suppression devices and discusses the experimental results. In particular, the measured attenuation factors are presented and compared with the theoretical predictions. 8 ref., 17 fig., 2 tab.

  6. Suppression and ritualistic behaviour in normal participants.

    Science.gov (United States)

    Rassin, E; Merckelbach, H; Muris, P; Stapert, S

    1999-06-01

    Previous research has shown that normal and abnormal ritualistic behaviours do not differ in content. Rather, the differences between both categories of rituals pertain to characteristics such as frequency, intensity, discomfort and resistance. This study sought to investigate whether thought suppression is linked to these characteristics. Cross-sectional; questionnaires on thought suppression and rituals were administered to a sample of undergraduate students (N = 166). Habitual suppressors (N = 20) and non-suppressors (N = 20), as measured by the White Bear Suppression Inventory, were selected and compared with regard to the characteristics of their rituals. Suppressors experienced their rituals as more intense, discomforting and resistance-provoking than did non-suppressors. There were no group differences in the content, frequency, and perceived senselessness of rituals. Although the cross-sectional nature of the present study precludes causal inferences, its findings are consistent with the view that chronic thought suppression may promote ritualistic behaviour. Clearly, the details of the link between thought suppression and rituals require further examination.

  7. Interocular suppression in children with deprivation amblyopia.

    Science.gov (United States)

    Hamm, Lisa; Chen, Zidong; Li, Jinrong; Black, Joanna; Dai, Shuan; Yuan, Junpeng; Yu, Minbin; Thompson, Benjamin

    2017-04-01

    In patients with anisometropic or strabismic amblyopia, interocular suppression can be minimized by presenting high contrast stimulus elements to the amblyopic eye and lower contrast elements to the fellow eye. This suggests a structurally intact binocular visual system that is functionally suppressed. We investigated whether suppression can also be overcome by contrast balancing in children with deprivation amblyopia due to childhood cataracts. To quantify interocular contrast balance, contrast interference thresholds were measured using an established dichoptic global motion technique for 21 children with deprivation amblyopia, 14 with anisometropic or mixed strabismic/anisometropic amblyopia and 10 visually normal children (mean age mean=9.9years, range 5-16years). We found that interocular suppression could be overcome by contrast balancing in most children with deprivation amblyopia, at least intermittently, and all children with anisometropic or mixed anisometropic/strabismic amblyopia. However, children with deprivation amblyopia due to early unilateral or bilateral cataracts could tolerate only very low contrast levels to the stronger eye indicating strong suppression. Our results suggest that treatment options reliant on contrast balanced dichoptic presentation could be attempted in a subset of children with deprivation amblyopia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Cosmological Parameters 2000

    OpenAIRE

    Primack, Joel R.

    2000-01-01

    The cosmological parameters that I emphasize are the age of the universe $t_0$, the Hubble parameter $H_0 \\equiv 100 h$ km s$^{-1}$ Mpc$^{-1}$, the average matter density $\\Omega_m$, the baryonic matter density $\\Omega_b$, the neutrino density $\\Omega_\

  9. Impulsive control of permanent magnet synchronous motors with parameters uncertainties

    International Nuclear Information System (INIS)

    Li Dong; Zhang Xiaohong; Wang Shilong; Yan Dan; Wang Hui

    2008-01-01

    The permanent magnet synchronous motors (PMSMs) may have chaotic behaviours for the uncertain values of parameters or under certain working conditions, which threatens the secure and stable operation of motor-driven. It is important to study methods of controlling or suppressing chaos in PMSMs. In this paper, robust stabilities of PMSM with parameter uncertainties are investigated. After the uncertain matrices which represent the variable system parameters are formulated through matrix analysis, a novel asymptotical stability criterion is established. Some illustrated examples are also given to show the effectiveness of the obtained results

  10. Modeling extreme ultraviolet suppression of electrostatic analyzers

    International Nuclear Information System (INIS)

    Gershman, Daniel J.; Zurbuchen, Thomas H.

    2010-01-01

    In addition to analyzing energy-per-charge ratios of incident ions, electrostatic analyzers (ESAs) for spaceborne time-of-flight mass spectrometers must also protect detectors from extreme ultraviolet (EUV) photons from the Sun. The required suppression rate often exceeds 1:10 7 and is generally established in tests upon instrument design and integration. This paper describes a novel technique to model the EUV suppression of ESAs using photon ray tracing integrated into SIMION, the most commonly used ion optics design software for such instruments. The paper compares simulation results with measurements taken from the ESA of the Mass instrument flying onboard the Wind spacecraft. This novel technique enables an active inclusion of EUV suppression requirements in the ESA design process. Furthermore, the simulation results also motivate design rules for such instruments.

  11. Quantum-mechanical suppression of bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Becker-Szendy, R.; Keller, L.; Niemi, G.; Perl, M.; Rochester, L. [Stanford Univ., CA (United States); Anthony, P. [Stanford Univ., CA (United States)]|[Lawrence Livermore National Lab., CA (United States); Bosted, P. [American Univ., Washington, DC (United States); Cavalli-Sforza, M.; Kelley, L.; Klein, S. [Univ. of California, Santa Cruz, CA (United States)] [and others

    1994-12-01

    The authors have studied quantum-mechanical suppression of bremsstrahlung of low-energy 1-500 MeV photons from high-energy 25 GeV electrons. They have measured the LPM effect, where multiple scattering of the radiating electron destroys coherence required for the emission of low-energy photons, and the dielectric effect, where the emitted photon traveling in the radiator medium interferes with itself. For the experiment, the collaboration developed a novel method of extracting a parasitic low-intensity high-energy electron beam into the fixed target area during normal SLC operation of the accelerator. The results agree quantitatively with Migdal`s calculation of the LPM effect. Surface effects, for which there is no satisfactory theoretical prediction, are visible at low photon energies. For very thin targets, the suppression disappears, as expected. Preliminary results on dielectric suppression of bremsstrahlung are in qualitative agreement with the expectation.

  12. Effects of thought suppression on episodic memory.

    Science.gov (United States)

    Rassin, E; Merckelbach, H; Muris, P

    1997-11-01

    Subjects were shown a short film fragment. Following this, one group of subjects (n = 26) was instructed to suppress their thoughts about the film, while the other group (n = 24) received no instructions. After 5 hrs subjects returned to the laboratory and completed a questionnaire testing their memory about the film. Results showed that suppression subjects reported a higher frequency of thoughts about the film than control subjects. No evidence was obtained for Wegner, Quillian, and Houston's (1996; Journal of Personality and Social Psychology, 71, 680-691) claim that suppression has an undermining effect on memory for chronology. Possible causes for the differences between the results as obtained by Wegner et al., and those found in the present study are discussed. These causes may pertain to the experimental design, but also to differences in emotional impact of the stimulus material that was used in both studies.

  13. Star formation suppression in compact group galaxies

    DEFF Research Database (Denmark)

    Alatalo, K.; Appleton, P. N.; Lisenfeld, U.

    2015-01-01

    We present CO(1-0) maps of 12 warm H-2-selected Hickson Compact Groups (HCGs), covering 14 individually imaged warm H2 bright galaxies, with the Combined Array for Research in Millimeter Astronomy. We found a variety of molecular gas distributions within the HCGs, including regularly rotating disks......, bars, rings, tidal tails, and possibly nuclear outflows, though the molecular gas morphologies are more consistent with spirals and earlytype galaxies than mergers and interacting systems. Our CO-imaged HCG galaxies, when plotted on the Kennicutt-Schmidt relation, shows star formation (SF) suppression......-to-dust ratios of these galaxies to determine if an incorrect LCO-M(H2) conversion caused the apparent suppression and find that HCGs have normal gas-to-dust ratios. It is likely that the cause of the apparent suppression in these objects is associated with shocks injecting turbulence into the molecular gas...

  14. Fractional Order Generalized Information

    Directory of Open Access Journals (Sweden)

    José Tenreiro Machado

    2014-04-01

    Full Text Available This paper formulates a novel expression for entropy inspired in the properties of Fractional Calculus. The characteristics of the generalized fractional entropy are tested both in standard probability distributions and real world data series. The results reveal that tuning the fractional order allow an high sensitivity to the signal evolution, which is useful in describing the dynamics of complex systems. The concepts are also extended to relative distances and tested with several sets of data, confirming the goodness of the generalization.

  15. Ordering, materiality and multiplicity

    DEFF Research Database (Denmark)

    van der Duim, René; Ren, Carina Bregnholm; Jóhannesson, Gunnar Thór

    2013-01-01

    In this article we discuss how ANT has been translated into tourism research and show how it has impacted the field by presenting three concepts integral to the ANT approach: ordering, materiality and multiplicity. We first introduce ANT and draw attention to current ANT studies in tourism......, followed by a discussion of how newer approaches within post-ANT urge us to face the ontological politics, which we engage in when performing tourism research. In conclusion we argue that ANT enables a radical new way at looking at tourism, tourism destinations and objects and investigations...

  16. Partially ordered algebraic systems

    CERN Document Server

    Fuchs, Laszlo

    2011-01-01

    Originally published in an important series of books on pure and applied mathematics, this monograph by a distinguished mathematician explores a high-level area in algebra. It constitutes the first systematic summary of research concerning partially ordered groups, semigroups, rings, and fields. The self-contained treatment features numerous problems, complete proofs, a detailed bibliography, and indexes. It presumes some knowledge of abstract algebra, providing necessary background and references where appropriate. This inexpensive edition of a hard-to-find systematic survey will fill a gap i

  17. Ordered sets and lattices

    CERN Document Server

    Drashkovicheva, Kh; Igoshin, V I; Katrinyak, T; Kolibiar, M

    1989-01-01

    This book is another publication in the recent surveys of ordered sets and lattices. The papers, which might be characterized as "reviews of reviews," are based on articles reviewed in the Referativnyibreve Zhurnal: Matematika from 1978 to 1982. For the sake of completeness, the authors also attempted to integrate information from other relevant articles from that period. The bibliography of each paper provides references to the reviews in RZhMat and Mathematical Reviews where one can seek more detailed information. Specifically excluded from consideration in this volume were such topics as al

  18. Dopa therapy and action impulsivity: subthreshold error activation and suppression in Parkinson's disease

    NARCIS (Netherlands)

    Fluchère, F.; Deveaux, M.; Burle, B.; Vidal, F.; van den Wildenberg, W.P.M.; Witjas, T.; Eusebio, A.; Azulay, J.-P.; Hasbroucq, T.

    2015-01-01

    Rationale: Impulsive actions entail (1) capture of the motor system by an action impulse, which is an urge to act and (2) failed suppression of that impulse in order to prevent a response error. Several studies indicate that dopaminergic treatment can induce action impulsivity in patients diagnosed

  19. Strong suppression of forward or backward Mie scattering by using spatial coherence

    NARCIS (Netherlands)

    Wang, Y.Y.D.; Schouten, H.F.; Visser, T.D.

    2016-01-01

    We derive analytic expressions relating Mie scattering with partially coherent fields to scattering with fully coherent fields. These equations are then used to demonstrate how the intensity of the forward- or backwardscattered field can be suppressed several orders of magnitude by tuning the

  20. The Design, Construction and Test of stray light suppression baffles for the CHAMP satellite

    DEFF Research Database (Denmark)

    Jørgensen, John Leif

    1997-01-01

    The Advanced Stellar Compass, to be delivered from IAU to the CHAMP project, requires some kind of stray-light suppressing shade to be mounted in front of the lens, in order to minimize the thermal impact and to maximize the performance envelope when subjected to non-stellar external light sources...

  1. Development and application of a probabilistic method for wildfire suppression cost modeling

    Science.gov (United States)

    Matthew P. Thompson; Jessica R. Haas; Mark A. Finney; David E. Calkin; Michael S. Hand; Mark J. Browne; Martin Halek; Karen C. Short; Isaac C. Grenfell

    2015-01-01

    Wildfire activity and escalating suppression costs continue to threaten the financial health of federal land management agencies. In order to minimize and effectively manage the cost of financial risk, agencies need the ability to quantify that risk. A fundamental aim of this research effort, therefore, is to develop a process for generating risk-based metrics for...

  2. Molecular orientational re-ordering and the transformation of a Landau second order phase transition to first order in a nematic liquid crystal

    International Nuclear Information System (INIS)

    Ponce, T.C.

    1988-08-01

    We consider the nature of the nematic to isotropic phase transition in terms of the molecular orientational re-ordering, expressed by the variation of the order parameter, s, in the light of Landau's theory of second order phase transition. Then, we show how the de Gennes modification to the Landau thermodynamic potential converts the transition to first order which is in better agreement with the experimental observations. (author). 9 refs, 2 figs, 1 tab

  3. QUALITY PARAMETERS IN NANOTECHNOLOGIC APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Ayşegül Akdoğan Eker

    2013-06-01

    Full Text Available Nanotechnology concept which has added a new dimension to our lives in recent years, is finding a place in every sector day by day. The combined effect of nanotechnology is almost equal to the industrial revolution of last 200 years and have is able to fill all developments in a few years. However this development should be taken under control. Otherwise unstoppable new structures will not ease life but will be a problem for humanity. For this purpose, the main parameters (from the start up stage of nano-technologic applications to the obtained product should be checked. These parameters are actually not different than the adaptation of the classical quality indicators for nanotechnology applications. Especially it plays an important role in obtaining a uniform distribution and regarding the features of the end product in nano-technological ceramic and etc. applications. The most important problem faced in particles of that size is the accumulation they create. Another problem is the increasing friction force as size gets smaller. The friction force of asubstance increases proportionally with the cube of its surface area. Another problem is surface tension. The increasing surface tension due to increasing surface area will cause the particles to attract and stick to each other. The structures aimed to be obtained are mostly complex and especially in upwards approach, it is thermodynamically very hard for the atoms to get into that order. Therefore in this announcement, we stated the quality parameters that will be taken into consideration in nano-technological applications and the methods for obtaining those parameters. The aim is to explain these parameters with all dimensions so that they will lead the way to the future nano-technological applications.

  4. Interval orders and reverse mathematics

    OpenAIRE

    Marcone, Alberto

    2006-01-01

    We study the reverse mathematics of interval orders. We establish the logical strength of the implications between various definitions of the notion of interval order. We also consider the strength of different versions of the characterization theorem for interval orders: a partial order is an interval order if and only if it does not contain $2 \\oplus 2$. We also study proper interval orders and their characterization theorem: a partial order is a proper interval order if and only if it cont...

  5. Male reproductive suppression: not a social affair.

    Science.gov (United States)

    Zizzari, Z Valentina; Jessen, Andrea; Koene, Joris M

    2017-10-01

    In the animal kingdom there are countless strategies via which males optimize their reproductive success when faced with male-male competition. These male strategies typically fall into two main categories: pre- and post-copulatory competition. Within these 2 categories, a set of behaviors, referred to as reproductive suppression, is known to cause inhibition of reproductive physiology and/or reproductive behavior in an otherwise fertile individual. What becomes evident when considering examples of reproductive suppression is that these strategies conventionally encompass reproductive interference strategies that occur between members of a hierarchical social group. However, mechanisms aimed at impairing a competitor's reproductive output are also present in non-social animals. Yet, current thinking emphasizes the importance of sociality as the primary driving force of reproductive suppression. Therefore, the question arises as to whether there is an actual difference between reproductive suppression strategies in social animals and equivalent pre-copulatory competition strategies in non-social animals. In this perspective paper we explore a broad taxonomic range of species whose individuals do not repeatedly interact with the same individuals in networks and yet, depress the fitness of rivals. Examples like alteration of male reproductive physiology, female mimicry, rival spermatophore destruction, and cementing the rival's genital region in non-social animals, highlight that male pre-copulatory reproductive suppression and male pre-copulatory competition overlap. Finally, we highlight that a distinction between male reproductive interference in animals with and without a social hierarchy might obscure important similarities and does not help to elucidate why different proximate mechanisms evolved. We therefore emphasize that male reproductive suppression need not be restricted to social animals.

  6. Fractional order junctions

    Science.gov (United States)

    Machado, J. Tenreiro

    2015-01-01

    Gottfried Leibniz generalized the derivation and integration, extending the operators from integer up to real, or even complex, orders. It is presently recognized that the resulting models capture long term memory effects difficult to describe by classical tools. Leon Chua generalized the set of lumped electrical elements that provide the building blocks in mathematical models. His proposal of the memristor and of higher order elements broadened the scope of variables and relationships embedded in the development of models. This paper follows the two directions and proposes a new logical step, by generalizing the concept of junction. Classical junctions interconnect system elements using simple algebraic restrictions. Nevertheless, this simplistic approach may be misleading in the presence of unexpected dynamical phenomena and requires including additional "parasitic" elements. The novel γ -junction includes, as special cases, the standard series and parallel connections and allows a new degree of freedom when building models. The proposal motivates the search for experimental and real world manifestations of the abstract conjectures.

  7. Jet suppression measurement with the ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00443411; The ATLAS collaboration

    2016-01-01

    A hot medium with a high density of unscreened color charges is produced in relativistic heavy ion collisions. Jets are produced at the early stages of this collision and are known to become attenuated as they propagate through the hot matter. One manifestation of this energy loss is a lower yield of jets emerging from the medium than expected in the absence of medium effects. Another manifestation of the energy loss is the modification of the dijet balance and the modification of fragmentation functions. In these proceedings, the latest ATLAS results on single jet suppression, dijet suppression, and modification of the jet internal structure in \\PbPb~collisions are presented.

  8. Suppression mental questionnaire: a preliminary study

    Directory of Open Access Journals (Sweden)

    Salvatore Settineri

    2016-08-01

    Full Text Available Authors postulate that the difference between suppression and repression, highlighted in particular by the Societè Psychanalitique de Paris, enables the development of a quantitative instrument, since suppression is a defense accessible to consciousness and therefore quantifiable like scales and questionnaires. The idea of constructing a questionnaire, included the identification of thirty variables having somehow a plausible relationship with this mechanism. The factor exploratory analysis were identified three factors, named respectly “repressive function”,  “regression to the ego service” and “rationalization”, the first of which is the closest to the theoretical construct postulated.

  9. Feedback suppression in digital hearing instruments

    DEFF Research Database (Denmark)

    Ma, Guilin

    . Methods to extract the fixed model are proposed and proved to be effective in representing the invariant part of the feedback path. Based on the investigation of the dynamic changes of the feedback path in adverse situations, for example when the user picks up the telephone handset, a reflection model...... is developed as one type of the fast varying models. The techniques to suppress the feedback are then reviewed. To improve the existing feedback suppression systems, two approaches are proposed to address the so-called “bias problem”. The first approach improves the performance of the adaptive feedback...... of the proposed feedback path models in the feedback cancellation systems is presented....

  10. Ordered photonic microstructures

    Science.gov (United States)

    Chen, Kevin Ming

    2001-09-01

    This thesis examines novel photonic materials systems possessing order in the atomic, microscopic, and macroscopic dimensional regimes. In the atomic order regime, a structure-property investigation is done for Er2O3 in which the first report of room temperature photoluminescence (PL) is provided. Thin films of the rare earth oxide were deposited via reactive sputtering of Er metal in an Ar/O2 ambient, and subsequently annealed to promote grain growth. Heat treatment consisting of a 650°C followed by 1000°C anneal produces maximum crystallinity as measured by glancing angle x-ray diffraction. These films show characteristic PL at λ = 1.54 μm. In the microscopic order regime, omnidirectional reflectors and thin film microcavities are demonstrated using sol-gel and solid-state materials. A first demonstration of omnidirectional reflectivity in sol-gel structures was accomplished using a dielectric stack consisting of 12 spin-on SiO 2/TiO2 quarterwave sol-gel films. Similarly, solid-state dielectric stacks consisting of 6 Si/SiO2 sputtered films were used to demonstrate the same principle. Microcavities were formed using solgel structures, producing a low quality factor Q = 35 due to limitations in film thickness control and lossy interfaces from stress-induced cracks. The high index contrast Si/SiO2 microcavities enabled Q ~ 1000 using 17 total layers following hydrogenation of dangling bonds within the amorphous Si films. Combining fabrication processes for the solid-state microcavity and Er2O3 films, a device was fabricated to demonstrate photoluminescence enhancement of an Er2O3 film embedded in a microcavity. The structure consisted of 3-bilayer mirrors on either side of an SiO2/Er2O3/SiO2 cavity. The Q ~ 300 was near the theoretical value for such a structure. At room temperature, PL of Er2O3 was enhanced by a factor of 1000 in the microcavity compared to a single thin film. In the macroscopic order regime, self-assembly of micron- sized SiO 2 and

  11. Radiatively-suppressed spherical accretion under relativistic radiative transfer

    Science.gov (United States)

    Fukue, Jun

    2018-03-01

    We numerically examine radiatively-suppressed relativistic spherical accretion flows on to a central object with mass M under Newtonian gravity and special relativity. We simultaneously solve both the relativistic radiative transfer equation and the relativistic hydrodynamical equations for spherically symmetric flows under the double iteration process in the case of the intermediate optical depth. We find that the accretion flow is suppressed, compared with the freefall case in the nonrelativistic regime. For example, in the case of accretion on to a luminous core with accretion luminosity L*, the freefall velocity v normalized by the speed of light c under the radiative force in the nonrelativistic regime is β (\\hat{r}) = v/c = -√{(1-Γ _*)/(\\hat{r}+1-Γ _*)}, where Γ* (≡ L*/LE, LE being the Eddington luminosity) is the Eddington parameter and \\hat{r} (= r/rS, rS being the Schwarzschild radius) the normalized radius, whereas the infall speed at the central core is ˜0.7β(1), irrespective of the mass-accretion rate. This is due to the relativistic effect; the comoving flux is enhanced by the advective flux. We briefly examine and discuss an isothermal case, where the emission takes place in the entire space.

  12. Higher order cumulants in colorless partonic plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cherif, S. [Sciences and Technologies Department, University of Ghardaia, Ghardaia, Algiers (Algeria); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ahmed, M. A. A. [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Department of Physics, Taiz University in Turba, Taiz (Yemen); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ladrem, M., E-mail: mladrem@yahoo.fr [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria)

    2016-06-10

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T{sub 0}(V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ{sub m,n}-Method is used. We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.

  13. Higher order cumulants in colorless partonic plasma

    International Nuclear Information System (INIS)

    Cherif, S.; Ahmed, M. A. A.; Ladrem, M.

    2016-01-01

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T 0 (V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ m,n -Method is used. We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.

  14. Model selection criteria : how to evaluate order restrictions

    NARCIS (Netherlands)

    Kuiper, R.M.

    2012-01-01

    Researchers often have ideas about the ordering of model parameters. They frequently have one or more theories about the ordering of the group means, in analysis of variance (ANOVA) models, or about the ordering of coefficients corresponding to the predictors, in regression models.A researcher might

  15. Chaos as compositional order

    Science.gov (United States)

    Angharad Pound, Eleri

    Composition is a combination of determined combinations of notes, durations and timbres usually decided upon in advance by a composer who plans carefully the sounds she desires. There is also always an element of chance present in acoustic music due to the 'human' element of the performance in that the performers will add their own interpretation of the dynamics and errors in terms of precise durations and pitches. Some composers have exploited this chance element more than others, allowing more space within the composition for the performers to make choices during the course of the piece. Composers such as Cage and Bussotti offer varying degrees of freedom within pieces resulting in unpredictability of the resulting sound of the composition. Other composers attempt to control as far as possible every parameter of the music as seen in serialist composers such as Webern and Boulez. This paper is delivered from the point of view of a composer who is intrigued by the relationship between the notation and the resultant sound, specifically, in terms of the relationship between the written elements determined by the composer and the unpredictability that arises due to those elements which cannot or are deliberately not written. These elements are then l to the interpretation and/or choice of the performer during the performance resulting in a composition which differs sonically from performance to performance. Chaos offers this combination of determination and the appearance of disorder: a clear structure within which are a number of elaborate chaotic-appearing options. The paper will focus on a composition-in-progress for voices which will offer the performers some choices based on the idea of sensitivity on initial conditions. Each singer will be provided with a set of headphones through which they will be fed a choice of pitches, the choices made for the first few pitches will determine the choices provided to the singer later on in the composition. The paper will

  16. Simulation and Testing of Novel Ferro-Transient Suppression Circuit for CVT

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Yesuraj, D. John; Joshi, Shailesh Ramesh

    2015-01-01

    In this paper a typical 400 kV CVT is simulated for Ferroresonance and Transient Response conditions using Active and Passive Ferroresonance Suppression Circuits (FSCs) available in the literature. The effect of the FSC and other parameters on the transient response is analyzed. A novel thyristor...... based Electronic FSC is proposed in this paper which is suitable to suppress both the Ferroresonance and the transient response oscillations in a CVT. The hardware of the Electronic FSC is designed and validated for both the Ferroresonance and the transient response conditions using the simulations...... as well as the laboratory tests. The simulations and laboratory test results show that, with the new Electronic FSC, the Ferroresonance is suppressed within 5 cycles and the CVT is meeting all transient response classes (3PT1, 3PT2, and 3PT3) of IEC 60044-5. The simulation of the CVT is performed using...

  17. On the properties of artificial neural network filters for bone-suppressed digital radiography

    Science.gov (United States)

    Park, Eunpyeong; Park, Junbeom; Kim, Daecheon; Youn, Hanbean; Jeon, Hosang; Kim, Jin Sung; Kang, Dong-Joong; Kim, Ho Kyung

    2016-04-01

    Dual-energy imaging can enhance lesion conspicuity. However, the conventional (fast kilovoltage switching) dual-shot dual-energy imaging is vulnerable to patient motion. The single-shot method requires a special design of detector system. Alternatively, single-shot bone-suppressed imaging is possible using post-image processing combined with a filter obtained from training an artificial neural network. In this study, the authors investigate the general properties of artificial neural network filters for bone-suppressed digital radiography. The filter properties are characterized in terms of various parameters such as the size of input vector, the number of hidden units, the learning rate, and so on. The preliminary result shows that the bone-suppressed image obtained from the filter, which is designed with 5,000 teaching images from a single radiograph, results in about 95% similarity with a commercial bone-enhanced image.

  18. Adaptive center determination for effective suppression of ring artifacts in tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Jha, D., E-mail: diwaker.jha@nano.ku.dk; Sørensen, H. O., E-mail: osholm@nano.ku.dk; Dobberschütz, S.; Stipp, S. L. S. [Nano-Science Center, Department of Chemistry, University of Copenhagen, Copenhagen (Denmark); Feidenhans' l, R. [Nano-Science Center, Niels Bohr Institute, University of Copenhagen, Copenhagen (Denmark)

    2014-10-06

    Ring artifacts on tomogram slices hinder image interpretation. They are caused by minor variation in the response from individual elements in a two dimensional (2D) X-ray detector. Polar space decreases the suppression complexity by transforming the rings on the tomogram slice to linear stripes. However, it requires that the center of rings lie at the origin of polar transformation. If this is not the case, all methods employing polar space become ineffective. We developed a method based on Gaussian localization of the ring center in Hough parameter space to assign the origin for the polar transformation. Thus, obtained linear stripes can be effectively suppressed by already existing methods. This effectively suppresses ring artifacts in the data from a variety of experimental setups, sample types and also handles tomograms that are previously cropped. This approach functions automatically, avoids the need for assumptions and preserves fine details, all critical for synchrotron based nanometer resolution tomography.

  19. Clustering reveals limits of parameter identifiability in multi-parameter models of biochemical dynamics.

    Science.gov (United States)

    Nienałtowski, Karol; Włodarczyk, Michał; Lipniacki, Tomasz; Komorowski, Michał

    2015-09-29

    Compared to engineering or physics problems, dynamical models in quantitative biology typically depend on a relatively large number of parameters. Progress in developing mathematics to manipulate such multi-parameter models and so enable their efficient interplay with experiments has been slow. Existing solutions are significantly limited by model size. In order to simplify analysis of multi-parameter models a method for clustering of model parameters is proposed. It is based on a derived statistically meaningful measure of similarity between groups of parameters. The measure quantifies to what extend changes in values of some parameters can be compensated by changes in values of other parameters. The proposed methodology provides a natural mathematical language to precisely communicate and visualise effects resulting from compensatory changes in values of parameters. As a results, a relevant insight into identifiability analysis and experimental planning can be obtained. Analysis of NF-κB and MAPK pathway models shows that highly compensative parameters constitute clusters consistent with the network topology. The method applied to examine an exceptionally rich set of published experiments on the NF-κB dynamics reveals that the experiments jointly ensure identifiability of only 60% of model parameters. The method indicates which further experiments should be performed in order to increase the number of identifiable parameters. We currently lack methods that simplify broadly understood analysis of multi-parameter models. The introduced tools depict mutually compensative effects between parameters to provide insight regarding role of individual parameters, identifiability and experimental design. The method can also find applications in related methodological areas of model simplification and parameters estimation.

  20. Forest Biophysical Parameters (SNF)

    Data.gov (United States)

    National Aeronautics and Space Administration — Biophysical parameters (DBH, NPP, biomass, bark area index, LAI, subcanopy LAI) by study site for Aspen and Spruce in the Superior National Forest, MN (SNF)

  1. SATELLITE CONSTELLATION DESIGN PARAMETER

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. SATELLITE CONSTELLATION DESIGN PARAMETER. 1. ORBIT CHARACTERISTICS. ORBITAL HEIGHT >= 20,000 KM. LONGER VISIBILITY; ORBITAL PERIOD. PERTURBATIONS(MINIMUM). SOLAR RADIATION PRESSURE (IMPACTS ECCENTRICITY); LUNI ...

  2. Robust H-infinity control in CD players to suppress external disturbances and defects on the disk

    DEFF Research Database (Denmark)

    Vidal, E.; Andersen, B.; Karlsson, R.V.

    2000-01-01

    This paper deals with the design and implementation of robust H8 controllers in order to suppress external disturbances and defects on the disk. Due to the conflictive requirements concerning the bandwidth of the closed loop to suppress external disturbances and defects on the disk, two independe...... H8 controllers are designed where norm-bounded uncertainties are assumed. The controllers are evaluated through an experiment showing better performance than a classical PID controller......This paper deals with the design and implementation of robust H8 controllers in order to suppress external disturbances and defects on the disk. Due to the conflictive requirements concerning the bandwidth of the closed loop to suppress external disturbances and defects on the disk, two independent...

  3. Higher Order Mode Fibers

    DEFF Research Database (Denmark)

    Israelsen, Stine Møller

    . In the second part of the thesis, a new scheme for constructing chirped microbend long period gratings is presented. The method presents a versatile platform for tailoring the chirp to the phase matching profile of the targeted HOM conversion in the fiber under test. The scheme introduces the ability......This PhD thesis considers higher order modes (HOMs) in optical fibers. That includes their excitation and characteristics. Within the last decades, HOMs have been applied both for space multiplexing in optical communications, group velocity dispersion management and sensing among others......-radial polarization as opposed to the linear polarization of the LP0X modes. The effect is investigated numerically in a double cladding fiber with an outer aircladding using a full vectorial modesolver. Experimentally, the bowtie modes are excited using a long period grating and their free space characteristics...

  4. Gender Orders Unbound

    DEFF Research Database (Denmark)

    , new complexities and contentions in gender relations emerge at various sites such as politics, work and families. The main aim of the book is to trace formal as well as informal gender contracts as they emerge in everyday life and also in new norms and regulations set by state and enterprises. Core...... issues are the chances and the barriers for equality and new forms of gender reciprocity and solidarity.......During the last thirty years, the modernisation of gender relations has been dynamic and comprehensive, shaped by the conflicting forces of globalisation as well as women's movements around the world. As the patterns of segregation and discrimination of the classical industrial gender order erode...

  5. Reassessment of safeguards parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hakkila, E.A.; Richter, J.L.; Mullen, M.F.

    1994-07-01

    The International Atomic Energy Agency is reassessing the timeliness and goal quantity parameters that are used in defining safeguards approaches. This study reviews technology developments since the parameters were established in the 1970s and concludes that there is no reason to relax goal quantity or conversion time for reactor-grade plutonium relative to weapons-grade plutonium. For low-enriched uranium, especially in countries with advanced enrichment capability there may be an incentive to shorten the detection time.

  6. Birth order and myopia.

    Science.gov (United States)

    Guggenheim, Jeremy A; McMahon, George; Northstone, Kate; Mandel, Yossi; Kaiserman, Igor; Stone, Richard A; Lin, Xiaoyu; Saw, Seang Mei; Forward, Hannah; Mackey, David A; Yazar, Seyhan; Young, Terri L; Williams, Cathy

    2013-12-01

    An association between birth order and reduced unaided vision (a surrogate for myopia) has been observed previously. We examined the association between birth order and myopia directly in four subject groups. Subject groups were participants in (1) the Avon Longitudinal Study of Parents and Children (ALSPAC; UK; age 15 years; N = 4401), (2) the Singapore Cohort Study of Risk Factors for Myopia (SCORM; Singapore; age 13 years; N = 1959), (3) the Raine Eye Health Study (REHS; Australia; age 20 years; N = 1344), and (4) Israeli Defense Force Pre-recruitment Candidates (IDFC; Israel; age 16-22 years; N = 888,277). The main outcome was odds ratios (OR) for myopia in first-born versus non-first-born individuals after adjusting for potential risk factors. The prevalence of myopia was numerically higher in first-born versus non-first-born individuals in all study groups, but the strength of evidence varied widely. Adjusted ORs (95% confidence intervals, CIs) were: ALSPAC, 1.31 (1.05-1.64); SCORM, 1.25 (0.89-1.77); REHS, 1.18 (0.90-1.55); and IDFC, 1.04 (1.03-1.06). In the large IDFC sample, the effect size was greater (a) for the first-born versus fourth- or higher-born comparison than for the first-born versus second/third-born comparison (p 4000 participants provided strong statistical support for the association. The available evidence suggested the relationship was independent of established risk factors such as time outdoors/reading, and thus may arise through a different causal mechanism.

  7. Speckle suppressing anisotropic diffusion filter for medical ultrasound images.

    Science.gov (United States)

    Ovireddy, Saraniya; Muthusamy, Ezhilarasi

    2014-04-01

    Ultrasonography is often preferred over the other medical imaging modalities due to its noninvasive nature, cost-effectiveness, and portability. However, the resolution of the ultrasound image greatly depends upon the presence of speckle noise. Speckle noise generally tends to reduce the image resolution and contrast, thereby reducing the diagnostic resolution of this imaging modality. In this paper, we propose a speckle suppressing anisotropic diffusion (SSAD) filter, to remove the speckle noise from B-Mode Ultrasound images. The performance of the SSAD filter is compared with the existing diffusion filters. The evaluation is based on their application to images simulated by Field II (developed by Jensen et al.). The algorithms were also tested for clinical ultrasound images of polycystic ovaries obtained from HDI 5000 Ultrasound Scanner. Performance evaluation was done by both numerical and functional parameters. The proposed filter yields better results in terms of greatest structural similarity index map (SSIM) of 0.95 and accuracy of 99.5.

  8. Noise Analysis of MAIA System and Possible Noise Suppression

    Directory of Open Access Journals (Sweden)

    J. Svihlik

    2011-04-01

    Full Text Available This paper is devoted to the noise analysis and noise suppression in a system for double station observation of the meteors now known as MAIA (Meteor Automatic Imager and Analyzer. The noise analysis is based on acquisition of testing video sequences in different light conditions and their further statistical evaluation. The main goal is to find a suitable noise model and subsequently determine if the noise is signal dependent or not. Noise and image model in the wavelet domain should be based on Gaussian mixture model (GMM or Generalized Laplacian Model (GLM and the model parameters should be estimated by moment method. Furthermore, noise should be modeled by GMM or GLM also in the space domain. GMM and GLM allow to model various types of probability density functions. Finally the advanced denoising algorithm using Bayesian estimator is applied and its performance is verified.

  9. T2 relaxation measurement with solvent suppression and implications to solvent suppression in general.

    Science.gov (United States)

    Hoffmann, Markus M; Sobstyl, Hanna S; Badali, Vincent A

    2009-07-01

    A number of suppression pulse sequences including Excitation Sculpting and WATERGATE were incorporated into the standard Carr-Purcell-Meiboom-Gill (CPMG) program for T(2) measurement and experimentally evaluated. The chosen suppression schemes were of varying complexity encompassing pulse program elements, such as presaturation, gradients, and selective pulses, which are typically utilized for solvent suppression. The quality of the spectral data and the accuracy of T(2) measurements of the investigated suppression schemes were evaluated using three aqueous samples with increasing proton content in the water solvent, i.e. by volume 100% D(2)O, 80/20% D(2)O/H(2)O, and 20/80% D(2)O/H(2)O. For signals removed from the water signal, the T(2) values were generally very consistent between all pulse sequences tested. T(2) measurements can be unreliable for signals too close to the water signal such that they are significantly suppressed as well. Their intensity may actually grow initially through cross relaxation that transfers magnetization back to the solute signal. In turn, this relaxation phenomenon can be exploited to improve the spectral quality of conventional solvent suppression schemes. In favorable cases, even signals that are completely masked by the water signal can be recovered by adding a carefully chosen number of spin echoes with optimized evolution time to conventional water suppression pulse programs, such as Excitation Sculpting or WATERGATE. 2009 John Wiley & Sons, Ltd.

  10. Reappraising suppression: subjective and physiological correlates of experiential suppression in healthy adults

    Directory of Open Access Journals (Sweden)

    Mathieu eLemaire

    2014-06-01

    Full Text Available Background: Emotion regulation strategies based on suppressing behavioural expressions of emotion have been considered maladaptive. However this may not apply to suppressing the emotional experience (experiential suppression. The aim of this study was to define the effect of experiential suppression on subjective and physiological emotional responses. Methods: Healthy adults (N=101 were characterized in terms of the temperament, personality, and hedonic capacity using the Tridimensional Personality Questionnaire, the Eysenck Personality Questionnaire, the Fawcett-Clark Pleasure Scale and the State-Trait Anxiety Inventory. Participants were shown positive, negative and neutral pictures from the International Affective Picture System under two conditions, passive viewing and experiential suppression. During both conditions, subjective ratings of the intensity and duration of emotional responses and physiological measures of skin conductance (SC and cardiac inter-beat interval (IBI to each picture were recorded.Results: Negative pictures elicited the most intense physiological and emotional responses regardless of experimental condition. Ratings of emotional intensity were not affected by condition. In contrast, experiential suppression, compared to passive viewing, was associated with decreased duration of the emotional response, reduced maximum SC amplitude and longer IBIs independent of age, picture valence, personality traits, hedonic capacity and anxiety. Conclusion: These findings demonstrate that experiential suppression may represent an adaptive emotion regulation mechanism associated with reduced arousal and cardiovascular activation.

  11. Reappraising suppression: subjective and physiological correlates of experiential suppression in healthy adults.

    Science.gov (United States)

    Lemaire, Mathieu; El-Hage, Wissam; Frangou, Sophia

    2014-01-01

    Emotion regulation strategies based on suppressing behavioral expressions of emotion have been considered maladaptive. However, this may not apply to suppressing the emotional experience (experiential suppression). The aim of this study was to define the effect of experiential suppression on subjective and physiological emotional responses. Healthy adults (N = 101) were characterized in terms of the temperament, personality, and hedonic capacity using the Tridimensional Personality Questionnaire, the Eysenck Personality Questionnaire, the Fawcett-Clark Pleasure Scale, and the State-Trait Anxiety Inventory. Participants were shown positive, negative, and neutral pictures from the International Affective Picture System under two conditions, passive viewing, and experiential suppression. During both conditions, subjective ratings of the intensity and duration of emotional responses and physiological measures of skin conductance (SC) and cardiac inter-beat interval (IBI) to each picture were recorded. Negative pictures elicited the most intense physiological and emotional responses regardless of experimental condition. Ratings of emotional intensity were not affected by condition. In contrast, experiential suppression, compared to passive viewing, was associated with decreased duration of the emotional response, reduced maximum SC amplitude and longer IBIs independent of age, picture valence, personality traits, hedonic capacity, and anxiety. These findings demonstrate that experiential suppression may represent an adaptive emotion regulation mechanism associated with reduced arousal and cardiovascular activation.

  12. Efflux inhibitor suppresses Streptococcus mutans virulence properties.

    Science.gov (United States)

    Zeng, Huihui; Liu, Jia; Ling, Junqi

    2017-04-01

    It is well established that efflux pumps play important roles in bacterial pathogenicity and efflux inhibitors (EIs) have been proved to be effective in suppressing bacterial virulence properties. However, little is known regarding the EI of Streptococcus mutans, a well-known caries-inducing bacterium. In this study, we identified the EI of S. mutans through ethidium bromide efflux assay and investigated how EI affected S. mutans virulence regarding the cariogenicity and stress response. Results indicated that reserpine, the identified EI, suppressed acid tolerance, mutacin production and transformation efficiency of S. mutans, and modified biofilm architecture and extracellular polysaccharide distribution. Suppressed glycosyltransferase activity was also noted after reserpine exposure. The data from quantitative real-time-PCR demonstrated that reserpine significantly altered the expression profile of quorum-sensing and virulence-associated genes. These findings suggest that reserpine represents a promising adjunct anticariogenic agent in that it suppresses virulence properties of S. mutans. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Evaluation of nematode suppression and yield improvement ...

    African Journals Online (AJOL)

    SARAH

    2017-11-30

    Nov 30, 2017 ... Objective: To investigate nematode suppression and yield improvement potential of two organic materials; poultry manure ... region of Ghana. The organic materials were applied on two sweet potato varieties; Apomuden and Santom ..... but a trend similar to what happened in 2014 occurred at. Atebubu.

  14. Genetic sequences derived from suppression subtractive ...

    African Journals Online (AJOL)

    Leaf scald disease (LSD) is caused by the Gram-negative bacterium, Xanthomonas albilineans. Genomic DNA from X. albilineans and Xanthomonas hyacinthi were analyzed by suppression subtractive hybridization (SSH) using X. albilineans as the tester from which unique sequences were sought and X. hyacinthi as the ...

  15. Suppressive competition: how sounds may cheat sight.

    Science.gov (United States)

    Kayser, Christoph; Remedios, Ryan

    2012-02-23

    In this issue of Neuron, Iurilli et al. (2012) demonstrate that auditory cortex activation directly engages local GABAergic circuits in V1 to induce sound-driven hyperpolarizations in layer 2/3 and layer 6 pyramidal neurons. Thereby, sounds can directly suppress V1 activity and visual driven behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Emotions shape memory suppression in trait anxiety

    Directory of Open Access Journals (Sweden)

    Tessa eMarzi

    2014-01-01

    Full Text Available The question that motivated this study was to investigate the relation between trait anxiety, emotions and memory control. To this aim, memory suppression was explored in high and low trait anxiety individuals with the Think/No-think paradigm. After learning associations between neutral words and emotional scenes (negative, positive and neutral, participants were shown a word and were requested either to think about the associated scene or to block it out from mind. Finally, in a test phase, participants were again shown each word and asked to recall the paired scene. The results show that memory control is influenced by high trait anxiety and emotions. Low trait anxiety individuals showed a memory suppression effect, whereas there was a lack of memory suppression in high trait anxious individuals, especially for emotionally negative scenes. Thus, we suggest that individuals with anxiety may have difficulty exerting cognitive control over memories with a negative valence. These findings provide evidence that memory suppression can be impaired by anxiety thus highlighting the crucial relation between cognitive control, emotions and individual differences in regulating emotions.

  17. Quarkonium suppression: Gluonic dissociation vs. colour screening

    Indian Academy of Sciences (India)

    mechanism comes into play for the initial conditions taken from the self screened parton cascade model in these studies. Keywords. Quark gluon plasma; J ψ; suppression; dissociation; colour screening. PACS No. 12.38.M. 1. Introduction. The last two decades have seen hectic activity towards identifying unique signatures ...

  18. Methanol Extract of Polyopes lancifolius Suppresses Tumor ...

    African Journals Online (AJOL)

    Results: The expression and activity of MMP-9 were significantly increased in response to TNF-α, but MEPL suppressed TNF-α-induced MMP-9 expression and activity. MEPL also inhibited TNF-α-induced MMP-9 expression at the transcriptional level by blocking the activation of the NF-κB signaling pathway. Furthermore ...

  19. Genetic sequences derived from suppression subtractive ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Genomic DNA from X. albilineans and Xanthomonas hyacinthi were analyzed by suppression subtractive ... Clone X. albilineans 12 showed 92% homology to the acetate repressor proteins and clone. X. albilineans 18 .... stranded DNA will be enriched for tester-specific DNA, as DNA fragments that are not ...

  20. Contour detection by surround suppression of texture

    NARCIS (Netherlands)

    Petkov, Nicolai; Tavares, JMRS; Jorge, RMN

    2007-01-01

    Based on a keynote lecture at Complmage 2006, Coimbra, Oct. 20-21, 2006, an overview is given of our activities in modelling and using surround inhibition for contour detection. The effect of suppression of a line or edge stimulus by similar surrounding stimuli is known from visual perception

  1. Are Patents used to Suppress Useful Technology?

    DEFF Research Database (Denmark)

    Howells, John

    2006-01-01

    suppression of innovation in the historical record (Dunford 1987; Merges and Nelson 1990). This paper shows that there are many errors of interpretation, both in the historical papers and in Dunford and Merges and Nelson's writing. Most important are confusions about the nature of technological competition...

  2. Robust H-infinity control in CD players to suppress external disturbances and defects on the disk

    DEFF Research Database (Denmark)

    Vidal, E.; Andersen, B.; Karlsson, R.V.

    2000-01-01

    This paper deals with the design and implementation of robust H8 controllers in order to suppress external disturbances and defects on the disk. Due to the conflictive requirements concerning the bandwidth of the closed loop to suppress external disturbances and defects on the disk, two independe...... H8 controllers are designed where norm-bounded uncertainties are assumed. The controllers are evaluated through an experiment showing better performance than a classical PID controller...

  3. Hubble Parameter Corrected Interactions in Cosmology

    Directory of Open Access Journals (Sweden)

    J. Sadeghi

    2014-01-01

    character opening a room for different kinds of manipulations. In this paper we will consider a modification of an interaction Q, where we accept that interaction parameter b1 (order of unity in Q=3Hb1ρ is time dependent and presented as a linear function of Hubble parameter H of the form b0+btH, where b and b0 are constants. We consider two different models including modified Chaplygin gas and polytropic gas which have bulk viscosity. Then, we investigate problem numerically and analyze behavior of different cosmological parameters concerning fluids and behavior of the universe.

  4. Effect of Island Overlap on ELM Suppression by Resonant Magnetic Perturbations in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Fenstermacher, M E; Evans, T E; Osborne, T H; Schaffer, M J; Aldan, M P; deGrassie, J S; Gohil, P; Joseph, I; Moyer, R A; Snyder, P B; Groebner, R J; Jakubowski, M; Leonard, A W; Schmitz, O

    2007-11-08

    Recent DIII-D [J.L. Luxon, et al., Nucl. Fusion 43, 1813 (2003)] experiments show a correlation between the extent of overlap of magnetic islands induced in the edge plasma by perturbation coils and complete suppression of Type-I edge localized modes (ELMs) in plasmas with ITER-like electron pedestal collisionality {nu}*{sub e} {approx} 0.1, flux surface shape and low edge safety factor (q{sub 95} {approx} 3.6). With fixed n = 3 resonant magnetic perturbation (RMP) strength, ELM suppression is obtained only in a finite window in the edge safety factor (q{sub 95}) consistent with maximizing the resonant component of the applied helical field. ELM suppression is obtained over an increasing range of q{sub 95} by either increasing the n = 3 RMP strength, or by adding n = 1 perturbations to 'fill in' gaps between islands across the edge plasma. The suppression of Type-I ELMs correlates with a minimum width of the edge region having magnetic islands with Chirikov parameter >1.0, based on vacuum calculations of RMP mode components excluding the plasma response or rotational shielding. The fraction of vacuum magnetic field lines that are lost from the plasma, with connection length to the divertor targets comparable to an electron-ion collisional mean free path, increases throughout the island overlap region in the ELM suppressed case compared with the ELMing case.

  5. Supersymmetry Parameter Analysis : SPA Convention and Project

    CERN Document Server

    Aguilar-Saavedra, J A; Allanach, Benjamin C; Arnowitt, R; Baer, H A; Bagger, J A; Balázs, C; Barger, V; Barnett, M; Bartl, Alfred; Battaglia, M; Bechtle, P; Belyaev, A; Berger, E L; Blair, G; Boos, E; Bélanger, G; Carena, M S; Choi, S Y; Deppisch, F; Desch, Klaus; Djouadi, A; Dutta, B; Dutta, S; Díaz, M A; Eberl, H; Ellis, Jonathan Richard; Erler, Jens; Fraas, H; Freitas, A; Fritzsche, T; Godbole, Rohini M; Gounaris, George J; Guasch, J; Gunion, J F; Haba, N; Haber, Howard E; Hagiwara, K; Han, L; Han, T; He, H J; Heinemeyer, S; Hesselbach, S; Hidaka, K; Hinchliffe, Ian; Hirsch, M; Hohenwarter-Sodek, K; Hollik, W; Hou, W S; Hurth, Tobias; Jack, I; Jiang, Y; Jones, D R T; Kalinowski, Jan; Kamon, T; Kane, G; Kang, S K; Kernreiter, T; Kilian, W; Kim, C S; King, S F; Kittel, O; Klasen, M; Kneur, J L; Kovarik, K; Kraml, Sabine; Krämer, M; Lafaye, R; Langacker, P; Logan, H E; Ma, W G; Majerotto, Walter; Martyn, H U; Matchev, K; Miller, D J; Mondragon, M; Moortgat-Pick, G; Moretti, S; Mori, T; Moultaka, G; Muanza, S; Mukhopadhyaya, B; Mühlleitner, M M; Nauenberg, U; Nojiri, M M; Nomura, D; Nowak, H; Okada, N; Olive, Keith A; Oller, W; Peskin, M; Plehn, T; Polesello, G; Porod, Werner; Quevedo, Fernando; Rainwater, D L; Reuter, J; Richardson, P; Rolbiecki, K; de Roeck, A; Weber, Ch.

    2006-01-01

    High-precision analyses of supersymmetry parameters aim at reconstructing the fundamental supersymmetric theory and its breaking mechanism. A well defined theoretical framework is needed when higher-order corrections are included. We propose such a scheme, Supersymmetry Parameter Analysis SPA, based on a consistent set of conventions and input parameters. A repository for computer programs is provided which connect parameters in different schemes and relate the Lagrangian parameters to physical observables at LHC and high energy e+e- linear collider experiments, i.e., masses, mixings, decay widths and production cross sections for supersymmetric particles. In addition, programs for calculating high-precision low energy observables, the density of cold dark matter (CDM) in the universe as well as the cross sections for CDM search experiments are included. The SPA scheme still requires extended efforts on both the theoretical and experimental side before data can be evaluated in the future at the level of the d...

  6. Optimisation of milling parameters using neural network

    Directory of Open Access Journals (Sweden)

    Lipski Jerzy

    2017-01-01

    Full Text Available The purpose of this study was to design and test an intelligent computer software developed with the purpose of increasing average productivity of milling not compromising the design features of the final product. The developed system generates optimal milling parameters based on the extent of tool wear. The introduced optimisation algorithm employs a multilayer model of a milling process developed in the artificial neural network. The input parameters for model training are the following: cutting speed vc, feed per tooth fz and the degree of tool wear measured by means of localised flank wear (VB3. The output parameter is the surface roughness of a machined surface Ra. Since the model in the neural network exhibits good approximation of functional relationships, it was applied to determine optimal milling parameters in changeable tool wear conditions (VB3 and stabilisation of surface roughness parameter Ra. Our solution enables constant control over surface roughness parameters and productivity of milling process after each assessment of tool condition. The recommended parameters, i.e. those which applied in milling ensure desired surface roughness and maximal productivity, are selected from all the parameters generated by the model. The developed software may constitute an expert system supporting a milling machine operator. In addition, the application may be installed on a mobile device (smartphone, connected to a tool wear diagnostics instrument and the machine tool controller in order to supply updated optimal parameters of milling. The presented solution facilitates tool life optimisation and decreasing tool change costs, particularly during prolonged operation.

  7. Behavioural Pattern of Invertibility Parameter of Arima Model ...

    African Journals Online (AJOL)

    It was deduced that behaviour of invertibility parameter πidepends on the order of autoregressive part (p), the order of integrated part (d), positive and negative values of moving average parameter (ϑ). Journal of the Nigerian Association of Mathematical Physics, Volume 19 (November, 2011), pp 591 – 606 ...

  8. Pump induced lasing suppression in Yb:Er-doped microlasers.

    Science.gov (United States)

    Lei, Fuchuan; Yang, Yong; Ward, Jonathan M; Nic Chormaic, Síle

    2017-10-02

    A pump source is one of the essential prerequisites in order to achieve lasing in a system, and, in most cases, a stronger pump leads to higher laser power at the output. However, this behavior may be suppressed if two pump beams are used. In this work, we show that lasing around the 1600 nm band can be suppressed completely if two pumps, at wavelengths of 980 nm and 1550 nm, are applied simultaneously to an Yb:Er-doped microlaser, whereas it can be revived by switching one of them off. This phenomenon can be explained by assuming that the presence of one pump (980 nm) changes the role of the other pump (1550 nm); more specifically, the 1550 nm pump starts to consume the population inversion instead of increasing it when the 980 nm pump power exceeds a certain value. As a result, the two pump fields lead to a closed-loop transition within the gain medium (i.e., the erbium ions). This study unveils an interplay similar to coherence effects between different pump pathways, thereby providing a reference for designing the laser pump, and may have applications in lasing control.

  9. Multitarget Tracking with Spatial Nonmaximum Suppressed Sensor Selection

    Directory of Open Access Journals (Sweden)

    Liang Ma

    2015-01-01

    Full Text Available Multitarget tracking is one of the most important applications of sensor networks, yet it is an extremely challenging problem since multisensor multitarget tracking itself is nontrivial and the difficulty is further compounded by sensor management. Recently, random finite set based Bayesian framework has opened doors for multitarget tracking with sensor management, which is modelled in the framework of partially observed Markov decision process (POMDP. However, sensor management posed as a POMDP is in essence a combinatorial optimization problem which is NP-hard and computationally unacceptable. In this paper, we propose a novel sensor selection method for multitarget tracking. We first present the sequential multi-Bernoulli filter as a centralized multisensor fusion scheme for multitarget tracking. In order to perform sensor selection, we define the hypothesis information gain (HIG of a sensor to measure its information quantity when the sensor is selected alone. Then, we propose spatial nonmaximum suppression approach to select sensors with respect to their locations and HIGs. Two distinguished implementations have been provided using the greedy spatial nonmaximum suppression. Simulation results verify the effectiveness of proposed sensor selection approach for multitarget tracking.

  10. Hyperchaotic Chameleon: Fractional Order FPGA Implementation

    Directory of Open Access Journals (Sweden)

    Karthikeyan Rajagopal

    2017-01-01

    Full Text Available There are many recent investigations on chaotic hidden attractors although hyperchaotic hidden attractor systems and their relationships have been less investigated. In this paper, we introduce a hyperchaotic system which can change between hidden attractor and self-excited attractor depending on the values of parameters. Dynamic properties of these systems are investigated. Fractional order models of these systems are derived and their bifurcation with fractional orders is discussed. Field programmable gate array (FPGA implementations of the systems with their power and resource utilization are presented.

  11. A comparison of different discrimination parameters for the DFT-based PSD method in fast scintillators

    International Nuclear Information System (INIS)

    Liu, G.; Yang, J.; Luo, X.L.; Lin, C.B.; Peng, J.X.; Yang, Y.

    2013-01-01

    Although the discrete Fourier transform (DFT) based pulse shape discrimination (PSD) method, realized by transforming the digitized scintillation pulses into frequency coefficients by using DFT, has been proven to effectively discriminate neutrons and γ rays, its discrimination performance depends strongly on the selection of the discrimination parameter obtained by the combination of these frequency coefficients. In order to thoroughly understand and apply the DFT-based PSD in organic scintillation detectors, a comparison of three different discrimination parameters, i.e. the amplitude of zero-frequency component, the amplitude difference between the amplitude of zero-frequency component and the amplitude of base-frequency component, and the ratio of the amplitude of base-frequency component to the amplitude of zero-frequency component, is described in this paper. An experimental setup consisting of an Americium–Beryllium (Am–Be) source, a BC501A liquid scintillator detector, and a 5Gsample/s 8-bit oscilloscope was built to assess the performance of the DFT-based PSD with each of these discrimination parameters in terms of the figure-of-merit (based on the separation of the event distributions). The third technique, which uses the ratio of the amplitude of base-frequency component to the amplitude of zero-frequency component as the discrimination parameter, is observed to provide the best discrimination performance in this research. - Highlights: • The spectrum difference between neutron pulse and γ-ray pulse was investigated. • The DFT-based PSD with different parameter definitions was assessed. • The way of using the ratio of magnitude spectrum provides the best performance. • The performance differences were explained from noise suppression features

  12. Benchmark enclosure fire suppression experiments - phase 1 test report.

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, Victor G.; Nichols, Robert Thomas; Blanchat, Thomas K.

    2007-06-01

    A series of fire benchmark water suppression tests were performed that may provide guidance for dispersal systems for the protection of high value assets. The test results provide boundary and temporal data necessary for water spray suppression model development and validation. A review of fire suppression in presented for both gaseous suppression and water mist fire suppression. The experimental setup and procedure for gathering water suppression performance data are shown. Characteristics of the nozzles used in the testing are presented. Results of the experiments are discussed.

  13. Magnetic S-parameter

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2010-01-01

    the magnetic S-parameter, i.e. the one determined via the dual magnetic gauge theory, assumes a simple expression in terms of the elementary magnetic degrees of freedom. The results further support our recent conjecture of the existence of a universal lower bound on the S parameter and indicates...... that it is an ideal operator for counting the active physical degrees of freedom within the conformal window. Our results can be directly used to unveil possible four dimensional gauge duals and constitute the first explicit computation of a nonperturbative quantity, in the electric variables, via nonsupersymmetric...

  14. PARAMETER DESIGN PROPELLER KAPAL

    Directory of Open Access Journals (Sweden)

    Muhammad Ridwan

    2012-04-01

    Full Text Available   Designer propeller kapal harus mempertimbangkan berbagai parameter untuk menghasilkan bentuk, type dan ukuran propeller yang memiliki nilai  efektifitas dan effisiensi propulsi tinggi. Propulsi kapal merupakan faktor yang mendominasi  operasional kapal, karena pemakaian bahan bakar untuk operasional propulsi kapal merupakan 42% dari total cost operasional kapal dan merupakan added value yang akan diperoleh oleh perusahaan pelayaran. Pertimbangan parameter desain propeller argonomis dapat mendukung tujuan di atas sehingga dapat menurunkan pemakaian bahan bakar hingga 20 % saat kapal dioperaionalkan.

  15. Band parameters of phosphorene

    DEFF Research Database (Denmark)

    Lew Yan Voon, L. C.; Wang, J.; Zhang, Y.

    2015-01-01

    Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory...... are computed using a first-principles theory based upon the generalized-gradient approximation to the density-functional theory. These parameters and Hamiltonian will be useful for modeling physical properties of phosphorene....

  16. Long-Range Order in β Brass

    DEFF Research Database (Denmark)

    Norvell, J.C.; Als-Nielsen, Jens Aage

    1970-01-01

    The long-range order parameter M of β brass has been determined from measurements of the intensity of superlattice reflections of Bragg-scattered neutrons. Over the whole temperature range T=300 °K to T=Tc=736 °K, the data are in remarkable agreement with the prediction for the compressible Ising...... bcc lattice with only nearest-neighbor interactions. © 1970 The American Physical Society...

  17. On a fourth order superlinear elliptic problem

    Directory of Open Access Journals (Sweden)

    M. Ramos

    2001-01-01

    Full Text Available We prove the existence of a nonzero solution for the fourth order elliptic equation $$Delta^2u= mu u +a(xg(u$$ with boundary conditions $u=Delta u=0$. Here, $mu$ is a real parameter, $g$ is superlinear both at zero and infinity and $a(x$ changes sign in $Omega$. The proof uses a variational argument based on the argument by Bahri-Lions cite{BL}.

  18. Coulomb suppression of the stellar enhancement factor

    International Nuclear Information System (INIS)

    Kiss, G.G.; Gyuerky, Gy.; Simon, A.; Fueloep, Zs.; Somorjai, E.

    2008-01-01

    Complete text of publication follows. Modern p process studies require large reaction networks, often including hundreds and thousands of nuclei and their respective reactions with light particles. Astrophysical reaction rates employed in reaction network calculations are determined either directly from cross sections or from the rate for the inverse reaction by applying detailed balance. The cross sections are known from experiment or predicted by theory. However, even when a reaction is experimentally accessible, often astrophysical rates cannot be directly measured. Excited states are thermally populated in an astrophysical plasma whereas only reactions on the ground state of the target can be investigated in the laboratory. A measure of the influence of the excited target states is given by the stellar enhancement factor f = r stellar /r g.s. , defined by the ratio of the stellar rate to the ground state rate. The enhancement factor f rev for the reverse reaction B(b,a)A (defined by having negative reaction Q value) is usually larger than the enhancement f forw of the forward reaction A(a,b)B (being the one with positive Q value) because more excited states are energetically accessible in nucleus B than in nucleus A. Therefore, it was assumed so far that more astrophysically relevant transitions are neglected when experimentally studying a reaction with negative Q value. However, there are cases for which f rev forw due to Coulomb suppression of a part of the energetically allowed transitions. This effect will be most pronounced in reactions with a charged particle in one and a neutral particle in the other channel, e.g. (n,p), but it can also appear when the entrance channel and exit channel have Coulomb barriers of different height, e.g. (p,α). Transitions from excited states to the same state in a compound nucleus are proceeding at smaller relative energy and are stronger suppressed by the Coulomb barrier. Thus, a prerequisite is that /Q/ is low compared to

  19. Study of exteroceptive suppression of voluntary muscular activity in healthy volunteers and patients with paroxysmal neuropathic pain.

    Science.gov (United States)

    Gordeev, S A; Turbina, L G; Shtang, O M

    2014-07-01

    The exteroceptive suppression of voluntary electromyographic activity of the masseter and temporal muscles was studied in healthy volunteers and patients with paroxysmal neuropathic pain (trigeminal neuralgia). The latent period of the exteroceptive suppression was prolonged and the duration of its late fragment was shortened in the patients in comparison with normal subjects. A short exteroceptive suppression period in patients with trigeminal neuralgia reflected deficient activity of inhibitory interneurons of the reflector loop and excessive activity of the antinociceptive system of the brain stem, while prolongation of the latent period reflected prolongation of inhibitory interneurons activation. A direct correlation between the degree of changes in the exteroceptive suppression parameters and pain intensity, evaluated by the patients by the visual analog scale, was detected.

  20. Observation of Wakefield Suppression in a Photonic-Band-Gap Accelerator Structure

    Science.gov (United States)

    Simakov, Evgenya I.; Arsenyev, Sergey A.; Buechler, Cynthia E.; Edwards, Randall L.; Romero, William P.; Conde, Manoel; Ha, Gwanghui; Power, John G.; Wisniewski, Eric E.; Jing, Chunguang

    2016-02-01

    We report experimental observation of higher order mode (HOM) wakefield suppression in a room-temperature traveling-wave photonic-band-gap (PBG) accelerating structure at 11.700 GHz. It has been long recognized that PBG structures have the potential for reducing long-range wakefields in accelerators. The first ever demonstration of acceleration in a room-temperature PBG structure was conducted in 2005. Since then, the importance of PBG accelerator research has been recognized by many institutions. However, the full experimental characterization of the wakefield spectrum and demonstration of wakefield suppression when the accelerating structure is excited by an electron beam has not been performed to date. We conducted an experiment at the Argonne Wakefield Accelerator test facility and observed wakefields excited by a single high charge electron bunch when it passes through a PBG accelerator structure. Excellent HOM suppression properties of the PBG accelerator were demonstrated in the beam test.

  1. Spironolactone induces apoptosis in human mononuclear cells. Association between apoptosis and cytokine suppression

    DEFF Research Database (Denmark)

    Mikkelsen, Martin; Sønder, S U; Nersting, J

    2006-01-01

    Spironolactone (SPIR) has been described to suppress accumulation of pro-inflammatory cytokines. Here, the suppression of TNF-alpha in lipopolysaccharide (LPS)-stimulated mononuclear cell cultures was confirmed. However, SPIR was also found to induce apoptosis, prompting the investigations...... of a possible association between the two effects: The apoptosis-inducing and the cytokine-suppressive effects of SPIR correlated with regard to the effective concentration range. Also, pre-incubation experiments demonstrated a temporal separation of the two effects of ... preceding apoptosis. An association between the two effects was also seen when testing several SPIR analogues. Contrary to TNF-alpha, the levels of IL-1beta increased in SPIR-treated cultures. However, the amount of IL-1beta in the supernatants depended upon the order of SPIR and LPS addition, as IL-1beta...

  2. Systematic design and simulation of a tearing mode suppression feedback control system for the TEXTOR tokamak

    International Nuclear Information System (INIS)

    Hennen, B.A.; Westerhof, E.; De Baar, M.R.; Nuij, P.W.J.M.; Steinbuch, M.

    2012-01-01

    Suppression of tearing modes is essential for the operation of tokamaks. This paper describes the design and simulation of a tearing mode suppression feedback control system for the TEXTOR tokamak. The two main control tasks of this feedback control system are the radial alignment of electron cyclotron resonance heating and current drive (ECRH/ECCD) with a tearing mode and the stabilization of a mode at a specific width. In order to simulate these control tasks, the time evolution of a tearing mode subject to suppression by ECRH/ECCD and destabilization by a magnetic perturbation field is modelled using the generalized Rutherford equation. The model includes an equilibrium model and an ECRH/ECCD launcher model. The dynamics and static equilibria of this model are analysed. The model is linearized and based on the linearized model, linear feedback controllers are designed and simulated, demonstrating both alignment and width control of tearing modes in TEXTOR. (paper)

  3. Second-order transport, quasinormal modes and zero-viscosity limit in the Gauss-Bonnet holographic fluid

    Energy Technology Data Exchange (ETDEWEB)

    Grozdanov, Sašo [Instituut-Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, Leiden 2333 CA (Netherlands); Starinets, Andrei O. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

    2017-03-30

    Gauss-Bonnet holographic fluid is a useful theoretical laboratory to study the effects of curvature-squared terms in the dual gravity action on transport coefficients, quasinormal spectra and the analytic structure of thermal correlators at strong coupling. To understand the behavior and possible pathologies of the Gauss-Bonnet fluid in 3+1 dimensions, we compute (analytically and non-perturbatively in the Gauss-Bonnet coupling) its second-order transport coefficients, the retarded two- and three-point correlation functions of the energy-momentum tensor in the hydrodynamic regime as well as the relevant quasinormal spectrum. The Haack-Yarom universal relation among the second-order transport coefficients is violated at second order in the Gauss-Bonnet coupling. In the zero-viscosity limit, the holographic fluid still produces entropy, while the momentum diffusion and the sound attenuation are suppressed at all orders in the hydrodynamic expansion. By adding higher-derivative electromagnetic field terms to the action, we also compute corrections to charge diffusion and identify the non-perturbative parameter regime in which the charge diffusion constant vanishes.

  4. Sulfated glycosaminoglycans support osteoblast functions and concurrently suppress osteoclasts.

    Science.gov (United States)

    Salbach-Hirsch, Juliane; Ziegler, Nicole; Thiele, Sylvia; Moeller, Stephanie; Schnabelrauch, Matthias; Hintze, Vera; Scharnweber, Dieter; Rauner, Martina; Hofbauer, Lorenz C

    2014-06-01

    In order to improve bone regeneration, development and evaluation of new adaptive biomaterials is warranted. Glycosaminoglycans (GAGs) such as hyaluronan (HA) and chondroitin sulfate (CS) are major extracellular matrix (ECM) components of bone, and display osteogenic properties that are potentially useful for biomaterial applications. Using native and synthetic sulfate-modified GAGs, we manufactured artificial collagen/GAG ECM (aECMs) coatings, and evaluated how the presence of GAGs and their degree of sulfation affects the differentiation of murine mesenchymal stem cells to osteoblasts (OB) cultivated on these aECMs. GAG sulfation regulated osteogenesis at all key steps of OB development. Adhesion, but not migration, was diminished by 50% (P osteogenesis and suppressing their paracrine support of OC functions, thus displaying a favorable profile on bone remodeling. Whether these cellular properties translate into improved bone regeneration needs to be validated in vivo. © 2014 Wiley Periodicals, Inc.

  5. Vibration suppression of composite laminated beams using distributed piezoelectric patches

    International Nuclear Information System (INIS)

    Foda, M A; Almajed, A A; ElMadany, M M

    2010-01-01

    The focus of this paper is to develop an analytical and straightforward approach to suppress the steady state transverse vibration of a symmetric cross-ply laminated composite beam that is excited by an external harmonic force. This is achieved by bonding patches of piezoelectric material at selected locations along the beam. The governing equations for the system are formulated and the dynamic Green's functions are used to obtain an exact solution for the problem. A scheme is proposed for determining the values of the driving voltages, the dimensions of the PZT patches and their locations along the beam, in order to confine the vibration in a certain chosen region where the vibration is not harmful and leave the other chosen region stationary or vibrating with very small amplitudes. Beams with different boundary conditions are considered. Numerical case studies are presented to verify the utility of the proposed scheme

  6. The effects of levothyroxine replacement or suppressive therapy on health status, mood, and cognition.

    Science.gov (United States)

    Samuels, Mary H; Kolobova, Irina; Smeraglio, Anne; Peters, Dawn; Janowsky, Jeri S; Schuff, Kathryn G

    2014-03-01

    TSH-suppressive doses of levothyroxine (L-T4) have adverse effects on bone and cardiac function, but it is unclear whether central nervous system function is also affected. The aim of the study was to determine whether women receiving TSH-suppressive L-T4 doses have decrements in health status, mood, or cognitive function. A cross-sectional comparison was made among three groups of women in an academic medical center research clinic. Twenty-four women receiving chronic TSH-suppressive L-T4 doses, 35 women receiving chronic replacement L-T4 doses, and 20 untreated control women participated in the study. Subjects underwent testing at a single outpatient visit. We measured health status (SF-36), mood (Profile of Mood States, Symptom Checklist 90-R, Affective Lability Scale), and cognitive function (declarative memory [Paragraph Recall], working memory [N-back, Subject Ordered Pointing], motor learning [Pursuit Rotor, Motor Sequence Learning Test], and executive function [Letter Cancellation Test, Trail Making Test, Iowa Gambling Test]). Women receiving TSH-suppressive or replacement L-T4 doses had decrements in health status and mood compared to healthy controls. These decrements were more pronounced in women receiving replacement, rather than suppressive, L-T4 doses. Memory and executive function were not affected in either treated group, compared to healthy controls. Women receiving TSH-suppressive doses of L-T4 do not have central nervous system dysfunction due to exogenous subclinical thyrotoxicosis, but TSH-suppressed and L-T4-replaced women have slight decrements in health status and mood that may be related to self-knowledge of the presence of a thyroid condition or other uncharacterized factors. These mood alterations do not impair cognitive function.

  7. Measuring the chargino parameters

    Indian Academy of Sciences (India)

    After the supersymmetric particles have been discovered, the priority will be to determine independently the fundamental parameters to reveal the structure of the underlying supersymmetric theory. In my talk I discuss how the chargino sector can be reconstructed completely by measuring the cross-sections with polarized ...

  8. Measuring the chargino parameters

    Indian Academy of Sciences (India)

    Instytut Fizyki Teoretycznej UW, Hoza 69, 00681 Warszawa, Poland. Abstract. After the supersymmetric particles have been discovered, the priority will be to deter- mine independently the fundamental parameters to reveal the structure of the underlying super- symmetric theory. In my talk I discuss how the chargino sector ...

  9. Dynamic Stability Parameters

    Science.gov (United States)

    1981-05-01

    on an aircraft fuselage or a slender body, as is demonstrated by the results obtained by Ruben 1 for his strut design (Fig. 13). Perkins showed the...are unique and demonstrate a very successful symbiosis of the powerful and flexible tool of parameter identification together with highly qualified

  10. Response model parameter linking

    NARCIS (Netherlands)

    Barrett, M.L.D.

    2015-01-01

    With a few exceptions, the problem of linking item response model parameters from different item calibrations has been conceptualized as an instance of the problem of equating observed scores on different test forms. This thesis argues, however, that the use of item response models does not require

  11. Managing for soil health can suppress pests

    Directory of Open Access Journals (Sweden)

    Amanda Hodson

    2016-08-01

    Full Text Available A “healthy” soil can be thought of as one that functions well, both agronomically and ecologically, and one in which soil biodiversity and crop management work in synergy to suppress pests and diseases. UC researchers have pioneered many ways of managing soil biology for pest management, including strategies such as soil solarization, steam treatment and anaerobic soil disinfestation, as well as improvements on traditional methods, such as reducing tillage, amending soil with organic materials, and cover cropping. As managing for soil health becomes more of an explicit focus due to restrictions on the use of soil fumigants, integrated soil health tests will be needed that are validated for use in California. Other research needs include breeding crops for disease resistance and pest suppressive microbial communities as well as knowledge of how beneficial organisms influence plant health.

  12. Suppression of Poxvirus Replication by Resveratrol

    Directory of Open Access Journals (Sweden)

    Shuai Cao

    2017-11-01

    Full Text Available Poxviruses continue to cause serious diseases even after eradication of the historically deadly infectious human disease, smallpox. Poxviruses are currently being developed as vaccine vectors and cancer therapeutic agents. Resveratrol is a natural polyphenol stilbenoid found in plants that has been shown to inhibit or enhance replication of a number of viruses, but the effect of resveratrol on poxvirus replication is unknown. In the present study, we found that resveratrol dramatically suppressed the replication of vaccinia virus (VACV, the prototypic member of poxviruses, in various cell types. Resveratrol also significantly reduced the replication of monkeypox virus, a zoonotic virus that is endemic in Western and Central Africa and causes human mortality. The inhibitory effect of resveratrol on poxviruses is independent of VACV N1 protein, a potential resveratrol binding target. Further experiments demonstrated that resveratrol had little effect on VACV early gene expression, while it suppressed VACV DNA synthesis, and subsequently post-replicative gene expression.

  13. Glucose Suppresses Biological Ferroelectricity in Aortic Elastin

    Science.gov (United States)

    Liu, Yuanming; Wang, Yunjie; Chow, Ming-Jay; Chen, Nataly Q.; Ma, Feiyue; Zhang, Yanhang; Li, Jiangyu

    2013-04-01

    Elastin is an intriguing extracellular matrix protein present in all connective tissues of vertebrates, rendering essential elasticity to connective tissues subjected to repeated physiological stresses. Using piezoresponse force microscopy, we show that the polarity of aortic elastin is switchable by an electrical field, which may be associated with the recently discovered biological ferroelectricity in the aorta. More interestingly, it is discovered that the switching in aortic elastin is largely suppressed by glucose treatment, which appears to freeze the internal asymmetric polar structures of elastin, making it much harder to switch, or suppressing the switching completely. Such loss of ferroelectricity could have important physiological and pathological implications from aging to arteriosclerosis that are closely related to glycation of elastin.

  14. Sleep deprivation suppresses aggression in Drosophila

    Science.gov (United States)

    Kayser, Matthew S; Mainwaring, Benjamin; Yue, Zhifeng; Sehgal, Amita

    2015-01-01

    Sleep disturbances negatively impact numerous functions and have been linked to aggression and violence. However, a clear effect of sleep deprivation on aggressive behaviors remains unclear. We find that acute sleep deprivation profoundly suppresses aggressive behaviors in the fruit fly, while other social behaviors are unaffected. This suppression is recovered following post-deprivation sleep rebound, and occurs regardless of the approach to achieve sleep loss. Genetic and pharmacologic approaches suggest octopamine signaling transmits changes in aggression upon sleep deprivation, and reduced aggression places sleep-deprived flies at a competitive disadvantage for obtaining a reproductive partner. These findings demonstrate an interaction between two phylogenetically conserved behaviors, and suggest that previous sleep experiences strongly modulate aggression with consequences for reproductive fitness. DOI: http://dx.doi.org/10.7554/eLife.07643.001 PMID:26216041

  15. Abnormal Grain Growth Suppression in Aluminum Alloys

    Science.gov (United States)

    Hales, Stephen J. (Inventor); Claytor, Harold Dale (Inventor); Alexa, Joel A. (Inventor)

    2015-01-01

    The present invention provides a process for suppressing abnormal grain growth in friction stir welded aluminum alloys by inserting an intermediate annealing treatment ("IAT") after the welding step on the article. The IAT may be followed by a solution heat treatment (SHT) on the article under effectively high solution heat treatment conditions. In at least some embodiments, a deformation step is conducted on the article under effective spin-forming deformation conditions or under effective superplastic deformation conditions. The invention further provides a welded article having suppressed abnormal grain growth, prepared by the process above. Preferably the article is characterized with greater than about 90% reduction in area fraction abnormal grain growth in any friction-stir-welded nugget.

  16. Suppression of Rabi oscillations for moving atoms

    International Nuclear Information System (INIS)

    Navarro, B.; Egusquiza, I. L.; Muga, J. G.; Hegerfeldt, G. C.

    2003-01-01

    The well-known laser-induced Rabi oscillations of a two-level atom are shown to be suppressed under certain conditions when the atom is entering a laser-illuminated region. For temporal Rabi oscillations the effect has two regimes: a first classical-like one, taking place at intermediate atomic velocities, and a second purely quantum case at low velocities. The classical regime is associated with the formation of incoherent internal states of the atom in the laser region, whereas in the quantum, low velocity regime the laser projects the atom onto a pure internal state that can be controlled by detuning. Spatial Rabi oscillations are only suppressed in this low velocity, quantum regime

  17. Overcoming fixation with repeated memory suppression.

    Science.gov (United States)

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

  18. Adaptive Suppression of Noise in Voice Communications

    Science.gov (United States)

    Kozel, David; DeVault, James A.; Birr, Richard B.

    2003-01-01

    A subsystem for the adaptive suppression of noise in a voice communication system effects a high level of reduction of noise that enters the system through microphones. The subsystem includes a digital signal processor (DSP) plus circuitry that implements voice-recognition and spectral- manipulation techniques. The development of the adaptive noise-suppression subsystem was prompted by the following considerations: During processing of the space shuttle at Kennedy Space Center, voice communications among test team members have been significantly impaired in several instances because some test participants have had to communicate from locations with high ambient noise levels. Ear protection for the personnel involved is commercially available and is used in such situations. However, commercially available noise-canceling microphones do not provide sufficient reduction of noise that enters through microphones and thus becomes transmitted on outbound communication links.

  19. Mechanisms underlying UV-induced immune suppression

    Energy Technology Data Exchange (ETDEWEB)

    Ullrich, Stephen E. [Department of Immunology, University of Texas, MD Anderson Cancer Center, South Campus Research Building 1, 7455 Fannin St., P.O. Box 301402, Houston, TX 77030-1903 (United States)]. E-mail: sullrich@mdanderson.org

    2005-04-01

    Skin cancer is the most prevalent form of human neoplasia. Estimates suggest that in excess of one million new cases of skin cancer will be diagnosed this year alone in the United States (www.cancer.org/statistics). Fortunately, because of their highly visible location, skin cancers are more rapidly diagnosed and more easily treated than other types of cancer. Be that as it may, approximately 10,000 Americans a year die from skin cancer. The cost of treating non-melanoma skin cancer is estimated to be in excess of US$ 650 million a year [J.G. Chen, A.B. Fleischer, E.D. Smith, C. Kancler, N.D. Goldman, P.M. Williford, S.R. Feldman, Cost of non-melanoma skin cancer treatment in the United States, Dermatol. Surg. 27 (2001) 1035-1038], and when melanoma is included, the estimated cost of treating skin cancer in the United States is estimated to rise to US$ 2.9 billion annually (www.cancer.org/statistics). Because the morbidity and mortality associated with skin cancer is a major public health problem, it is important to understand the mechanisms underlying skin cancer development. The primary cause of skin cancer is the ultraviolet (UV) radiation found in sunlight. In addition to its carcinogenic potential, UV radiation is also immune suppressive. In fact, data from studies with both experimental animals and biopsy proven skin cancer patients suggest that there is an association between the immune suppressive effects of UV radiation and its carcinogenic potential. The focus of this manuscript will be to review the mechanisms underlying the induction of immune suppression following UV exposure. Particular attention will be directed to the role of soluble mediators in activating immune suppression.

  20. Emotions shape memory suppression in trait anxiety

    OpenAIRE

    Marzi, Tessa; Regina, Antonio; Righi, Stefania

    2014-01-01

    The question that motivated this study was to investigate the relation between trait anxiety, emotions and memory control. To this aim, memory suppression was explored in high and low trait anxiety individuals with the Think/No-think paradigm. After learning associations between neutral words and emotional scenes (negative, positive, and neutral), participants were shown a word and were requested either to think about the associated scene or to block it out from mind. Finally, in a test phase...