WorldWideScience

Sample records for single order parameter

  1. 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...

  2. 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...

  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. 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...

  7. 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)

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  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. 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.

  1. 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

  2. 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...

  3. 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 ...

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. Aerosol water parameterization: a single parameter framework

    Science.gov (United States)

    Metzger, S.; Steil, B.; Abdelkader, M.; Klingmüller, K.; Xu, L.; Penner, J. E.; Fountoukis, C.; Nenes, A.; Lelieveld, J.

    2015-11-01

    We introduce a framework to efficiently parameterize the aerosol water uptake for mixtures of semi-volatile and non-volatile compounds, based on the coefficient, νi. This solute specific coefficient was introduced in Metzger et al. (2012) to accurately parameterize the single solution hygroscopic growth, considering the Kelvin effect - accounting for the water uptake of concentrated nanometer sized particles up to dilute solutions, i.e., from the compounds relative humidity of deliquescence (RHD) up to supersaturation (Köhler-theory). Here we extend the νi-parameterization from single to mixed solutions. We evaluate our framework at various levels of complexity, by considering the full gas-liquid-solid partitioning for a comprehensive comparison with reference calculations using the E-AIM, EQUISOLV II, ISORROPIA II models as well as textbook examples. We apply our parameterization in EQSAM4clim, the EQuilibrium Simplified Aerosol Model V4 for climate simulations, implemented in a box model and in the global chemistry-climate model EMAC. Our results show: (i) that the νi-approach enables to analytically solve the entire gas-liquid-solid partitioning and the mixed solution water uptake with sufficient accuracy, (ii) that, e.g., pure ammonium nitrate and mixed ammonium nitrate - ammonium sulfate mixtures can be solved with a simple method, and (iii) that the aerosol optical depth (AOD) simulations are in close agreement with remote sensing observations for the year 2005. Long-term evaluation of the EMAC results based on EQSAM4clim and ISORROPIA II will be presented separately.

  11. A comparison study of steady-state vibrations with single fractional-order and distributed-order derivatives

    Directory of Open Access Journals (Sweden)

    Duan Jun-Sheng

    2017-12-01

    Full Text Available We conduct a detailed study and comparison for the one-degree-of-freedom steady-state vibrations under harmonic driving with a single fractional-order derivative and a distributed-order derivative. For each of the two vibration systems, we consider the stiffness contribution factor and damping contribution factor of the term of fractional derivatives, the amplitude and the phase difference for the response. The effects of driving frequency on these response quantities are discussed. Also the influences of the order α of the fractional derivative and the parameter γ parameterizing the weight function in the distributed-order derivative are analyzed. Two cases display similar response behaviors, but the stiffness contribution factor and damping contribution factor of the distributed-order derivative are almost monotonic change with the parameter γ, not exactly like the case of single fractional-order derivative for the order α. The case of the distributed-order derivative provides us more options for the weight function and parameters.

  12. 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.

  13. Ordered macro-microporous metal-organic framework single crystals

    Science.gov (United States)

    Shen, Kui; Zhang, Lei; Chen, Xiaodong; Liu, Lingmei; Zhang, Daliang; Han, Yu; Chen, Junying; Long, Jilan; Luque, Rafael; Li, Yingwei; Chen, Banglin

    2018-01-01

    We constructed highly oriented and ordered macropores within metal-organic framework (MOF) single crystals, opening up the area of three-dimensional–ordered macro-microporous materials (that is, materials containing both macro- and micropores) in single-crystalline form. Our methodology relies on the strong shaping effects of a polystyrene nanosphere monolith template and a double-solvent–induced heterogeneous nucleation approach. This process synergistically enabled the in situ growth of MOFs within ordered voids, rendering a single crystal with oriented and ordered macro-microporous structure. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional, polycrystalline hollow, and disordered macroporous ZIF-8.

  14. Ordered macro-microporous metal-organic framework single crystals

    KAUST Repository

    Shen, Kui

    2018-01-16

    We constructed highly oriented and ordered macropores within metal-organic framework (MOF) single crystals, opening up the area of three-dimensional-ordered macro-microporous materials (that is, materials containing both macro- and micropores) in single-crystalline form. Our methodology relies on the strong shaping effects of a polystyrene nanosphere monolith template and a double-solvent-induced heterogeneous nucleation approach. This process synergistically enabled the in situ growth of MOFs within ordered voids, rendering a single crystal with oriented and ordered macro-microporous structure. The improved mass diffusion properties of such hierarchical frameworks, together with their robust single-crystalline nature, endow them with superior catalytic activity and recyclability for bulky-molecule reactions, as compared with conventional, polycrystalline hollow, and disordered macroporous ZIF-8.

  15. Cheap arbitrary high order methods for single integrand SDEs

    DEFF Research Database (Denmark)

    Debrabant, Kristian; Kværnø, Anne

    2017-01-01

    For a particular class of Stratonovich SDE problems, here denoted as single integrand SDEs, we prove that by applying a deterministic Runge-Kutta method of order $p_d$ we obtain methods converging in the mean-square and weak sense with order $\\lfloor p_d/2\\rfloor$. The reason is that the B-series...

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Single-level resonance parameters fit nuclear cross-sections

    Science.gov (United States)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  1. Single-Channel Blind Estimation of Reverberation Parameters

    DEFF Research Database (Denmark)

    Doire, C.S.J.; Brookes, M. D.; Naylor, P. A.

    2015-01-01

    The reverberation of an acoustic channel can be characterised by two frequency-dependent parameters: the reverberation time and the direct-to-reverberant energy ratio. This paper presents an algorithm for blindly determining these parameters from a single-channel speech signal. The algorithm uses...

  2. MATHEMATICAL MODELING OF FLOW PARAMETERS FOR SINGLE WIND TURBINE

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available It is known that on the territory of the Russian Federation the construction of several large wind farms is planned. The tasks connected with design and efficiency evaluation of wind farm work are in demand today. One of the possible directions in design is connected with mathematical modeling. The method of large eddy simulation developed within the direction of computational hydrodynamics allows to reproduce unsteady structure of the flow in details and to determine various integrated values. The calculation of work for single wind turbine installation by means of large eddy simulation and Actuator Line Method along the turbine blade is given in this work. For problem definition the numerical method in the form of a box was considered and the adapted unstructured grid was used.The mathematical model included the main equations of continuity and momentum equations for incompressible fluid. The large-scale vortex structures were calculated by means of integration of the filtered equations. The calculation was carried out with Smagorinsky model for determination of subgrid scale turbulent viscosity. The geometrical parametersof wind turbine were set proceeding from open sources in the Internet.All physical values were defined at center of computational cell. The approximation of items in equations was ex- ecuted with the second order of accuracy for time and space. The equations for coupling velocity and pressure were solved by means of iterative algorithm PIMPLE. The total quantity of the calculated physical values on each time step was equal to 18. So, the resources of a high performance cluster were required.As a result of flow calculation in wake for the three-bladed turbine average and instantaneous values of velocity, pressure, subgrid kinetic energy and turbulent viscosity, components of subgrid stress tensor were worked out. The re- ceived results matched the known results of experiments and numerical simulation, testify the opportunity

  3. Magnetic order of Nd5Pb3 single crystals

    Science.gov (United States)

    Yan, J.-Q.; Ochi, M.; Cao, H. B.; Saparov, B.; Cheng, J.-G.; Uwatoko, Y.; Arita, R.; Sales, B. C.; Mandrus, D. G.

    2018-04-01

    We report millimeter-sized Nd5Pb3 single crystals grown out of a Nd-Co flux. We experimentally study the magnetic order of Nd5Pb3 single crystals by measuring the anisotropic magnetic properties, electrical resistivity under high pressure up to 8 GPa, specific heat, and neutron single crystal diffraction. Two successive magnetic orders are observed at T N1  =  44 K and T N2  =  8 K. The magnetic cells can be described with a propagation vector k=(0.5, 0, 0) . Cooling below T N1, Nd1 and Nd3 order forming ferromagnetic stripes along the b-axis, and the ferromagnetic stripes are coupled antiferromagnetically along the a-axis for the k=(0.5, 0, 0) magnetic domain. Cooling below T N2, Nd2 orders antiferromagnetically to nearby Nd3 ions. All ordered moments align along the crystallographic c-axis. The magnetic order at T N1 is accompanied by a quick drop of electrical resistivity upon cooling and a lambda-type anomaly in the temperature dependence of specific heat. At T N2, no anomaly was observed in electrical resistivity but there is a weak feature in specific heat. The resistivity measurements under hydrostatic pressures up to 8 GPa suggest a possible phase transition around 6 GPa. Our first-principles band structure calculations show that Nd5Pb3 has the same electronic structure as does Y5Si3 which has been reported to be a one-dimensional electride with anionic electrons that do not belong to any atom. Our study suggests that R 5Pb3 (R  =  rare earth) can be a materials playground for the study of magnetic electrides. This deserves further study after experimental confirmation of the presence of anionic electrons.

  4. 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.

  5. Parameter Estimation for Single Diode Models of Photovoltaic Modules

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Clifford [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photovoltaic and Distributed Systems Integration Dept.

    2015-03-01

    Many popular models for photovoltaic system performance employ a single diode model to compute the I - V curve for a module or string of modules at given irradiance and temperature conditions. A single diode model requires a number of parameters to be estimated from measured I - V curves. Many available parameter estimation methods use only short circuit, o pen circuit and maximum power points for a single I - V curve at standard test conditions together with temperature coefficients determined separately for individual cells. In contrast, module testing frequently records I - V curves over a wide range of irradi ance and temperature conditions which, when available , should also be used to parameterize the performance model. We present a parameter estimation method that makes use of a fu ll range of available I - V curves. We verify the accuracy of the method by recov ering known parameter values from simulated I - V curves . We validate the method by estimating model parameters for a module using outdoor test data and predicting the outdoor performance of the module.

  6. 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

  7. 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.

  8. 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...

  9. 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”.

  10. 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.

  11. Pulling back error to the hidden-node parameter technology: Single-hidden-layer feedforward network without output weight

    OpenAIRE

    Yang, Yimin; Wu, Q. M. Jonathan; Huang, Guangbin; Wang, Yaonan

    2014-01-01

    According to conventional neural network theories, the feature of single-hidden-layer feedforward neural networks(SLFNs) resorts to parameters of the weighted connections and hidden nodes. SLFNs are universal approximators when at least the parameters of the networks including hidden-node parameter and output weight are exist. Unlike above neural network theories, this paper indicates that in order to let SLFNs work as universal approximators, one may simply calculate the hidden node paramete...

  12. Determination of heterogeneous medium parameters by single fuel element method

    International Nuclear Information System (INIS)

    Veloso, M.A.F.

    1985-01-01

    The neutron pulse propagation technique was employed to study an heterogeneous system consisting of a single fuel element placed at the symmetry axis of a large cylindrical D 2 O tank. The response of system for the pulse propagation technique is related to the inverse complex relaxation length of the neutron waves also known as the system dispersion law ρ (ω). Experimental values of ρ (ω) were compared with the ones derived from Fermi age - Diffusion theory. The main purpose of the experiment was to obtain the Feinberg-Galanin thermal constant (γ), which is the logaritmic derivative of the neutron flux at the fuel-moderator interface and a such a main input data for heterogeneous reactor theory calculations. The γ thermal constant was determined as the number giving the best agreement between the theoretical and experimental values of ρ (ω). The simultaneous determination of two among four parameters η,ρ,τ and L s is possible through the intersection of dispersion laws of the pure moderator system and the fuel moderator system. The parameters τ and η were termined by this method. It was shown that the thermal constant γ and the product η ρ can be computed from the real and imaginary parts of the fuel-moderator dispersion law. The results for this evaluation scheme showns a not stable behavior of γ as a function of frequency, a result not foreseen by the theoretical model. (Author) [pt

  13. Bayesian analysis of inflation: Parameter estimation for single field models

    International Nuclear Information System (INIS)

    Mortonson, Michael J.; Peiris, Hiranya V.; Easther, Richard

    2011-01-01

    Future astrophysical data sets promise to strengthen constraints on models of inflation, and extracting these constraints requires methods and tools commensurate with the quality of the data. In this paper we describe ModeCode, a new, publicly available code that computes the primordial scalar and tensor power spectra for single-field inflationary models. ModeCode solves the inflationary mode equations numerically, avoiding the slow roll approximation. It is interfaced with CAMB and CosmoMC to compute cosmic microwave background angular power spectra and perform likelihood analysis and parameter estimation. ModeCode is easily extendable to additional models of inflation, and future updates will include Bayesian model comparison. Errors from ModeCode contribute negligibly to the error budget for analyses of data from Planck or other next generation experiments. We constrain representative single-field models (φ n with n=2/3, 1, 2, and 4, natural inflation, and 'hilltop' inflation) using current data, and provide forecasts for Planck. From current data, we obtain weak but nontrivial limits on the post-inflationary physics, which is a significant source of uncertainty in the predictions of inflationary models, while we find that Planck will dramatically improve these constraints. In particular, Planck will link the inflationary dynamics with the post-inflationary growth of the horizon, and thus begin to probe the ''primordial dark ages'' between TeV and grand unified theory scale energies.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Third-order NLO properties of solution grown methyl- p-hydroxy benzoate single crystals

    Science.gov (United States)

    Manikandan, S.; Sabari Girisun, T. C.; Mohandoss, R.; Dhanuskodi, S.; Manivannan, S.

    2014-09-01

    The third-order nonlinear optical properties of solution-grown methyl- p-hydroxy benzoate (MHB) single crystals were studied by Z-scan technique using a He-Ne (632.8 nm, 30 mW) laser. From the closed aperture Z-scan data, the valley followed by peak on the normalized transmittance indicates the sign of the nonlinear refractive index is positive and shows a self focusing nature. From the open aperture Z-scan curve, it is found that the nonlinear absorption is due to saturation. The order of magnitude of third order susceptibility was estimated to be 10-6 esu. UV-Vis-NIR spectrum of MHB single crystal reveals a very low cutoff wavelength (310 nm) and transparency in the entire visible region. Also the material has direct allowed transition and it possesses a band gap of 3.7 eV. The dissipation factor is low and SHG efficiency is high. The higher magnitudes of second and third order NLO parameters make the material suitable for photonic applications like frequency conversion and eye/sensor protection.

  3. 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

  4. 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...

  5. Optimization of Laser Beam Transformation Hardening by One Single Parameter

    NARCIS (Netherlands)

    Meijer, J.; van Sprang, I.

    1991-01-01

    The process of laser beam transformation hardening is principally controlled by two independent parameters, the absorbed laser power on a given area and the interaction time. These parameters can be transformed into two functional parameters: the maximum surface temperature and the hardening depth.

  6. Return handling options and order quantities for single period products

    OpenAIRE

    Vlachos, D.; Dekker, R.

    2000-01-01

    textabstractProducts which are sold through E-commerce or mail sales catalogues tend to have a much higher return rate than traditional products. The returns are especially problematic for seasonal products. To support decision making in these situations we study various options, which may be considered as strategic decisions, on handling the increased return flow. Closed form analytic expressions for optimal order quantities are obtained by solving the models developed for each option. Decis...

  7. 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 ...

  8. 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)

  9. 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.

  10. 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.)

  11. 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.)

  12. 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.

  13. Combustion Model and Control Parameter Optimization Methods for Single Cylinder Diesel Engine

    Directory of Open Access Journals (Sweden)

    Bambang Wahono

    2014-01-01

    Full Text Available This research presents a method to construct a combustion model and a method to optimize some control parameters of diesel engine in order to develop a model-based control system. The construction purpose of the model is to appropriately manage some control parameters to obtain the values of fuel consumption and emission as the engine output objectives. Stepwise method considering multicollinearity was applied to construct combustion model with the polynomial model. Using the experimental data of a single cylinder diesel engine, the model of power, BSFC, NOx, and soot on multiple injection diesel engines was built. The proposed method succesfully developed the model that describes control parameters in relation to the engine outputs. Although many control devices can be mounted to diesel engine, optimization technique is required to utilize this method in finding optimal engine operating conditions efficiently beside the existing development of individual emission control methods. Particle swarm optimization (PSO was used to calculate control parameters to optimize fuel consumption and emission based on the model. The proposed method is able to calculate control parameters efficiently to optimize evaluation item based on the model. Finally, the model which added PSO then was compiled in a microcontroller.

  14. Single-electrode monitors for relativistic intense electron beam parameters

    International Nuclear Information System (INIS)

    Stratienko, V.A.; Khorenko, V.K.

    1977-01-01

    A single-electrode monitor operating in atmosphere on delta-electrons for precision measurement of high-intensity electron beams is developed. As an emitter is used a 0.2 mm aluminium foil with a hole which is a replica of the sample subjected to radiation. The electric charge from the emitter is recorded by a current integrator. The single-electrode monitor enabled to form a 225 MeV electron beam with a flux density of 5x10 15 electrons/ (cm 2 and confine the latter for 140 hours with an accuracy of +- 0.2 mm. Controlling the beam shifting by means of the single-electrode monitor described, it is possible to measure the real dimensions and density distributions of high-intensity electron beams

  15. Single-photon blockade in a hybrid cavity-optomechanical system via third-order nonlinearity

    Science.gov (United States)

    Sarma, Bijita; Sarma, Amarendra K.

    2018-04-01

    Photon statistics in a weakly driven optomechanical cavity, with Kerr-type nonlinearity, are analyzed both analytically and numerically. The single-photon blockade effect is demonstrated via calculations of the zero-time-delay second-order correlation function g (2)(0). The analytical results obtained by solving the Schrödinger equation are in complete conformity with the results obtained through numerical solution of the quantum master equation. A systematic study on the parameter regime for observing photon blockade in the weak coupling regime is reported. The parameter regime where the photon blockade is not realizable due to the combined effect of nonlinearities owing to the optomechanical coupling and the Kerr-effect is demonstrated. The experimental feasibility with state-of-the-art device parameters is discussed and it is observed that photon blockade could be generated at the telecommunication wavelength. An elaborate analysis of the thermal effects on photon antibunching is presented. The system is found to be robust against pure dephasing-induced decoherences and thermal phonon number fluctuations.

  16. 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)

  17. Effects of the physiological parameters on the signal-to-noise ratio of single myoelectric channel

    Directory of Open Access Journals (Sweden)

    Zhang YT

    2007-08-01

    Full Text Available Abstract Background An important measure of the performance of a myoelectric (ME control system for powered artificial limbs is the signal-to-noise ratio (SNR at the output of ME channel. However, few studies illustrated the neuron-muscular interactive effects on the SNR at ME control channel output. In order to obtain a comprehensive understanding on the relationship between the physiology of individual motor unit and the ME control performance, this study investigates the effects of physiological factors on the SNR of single ME channel by an analytical and simulation approach, where the SNR is defined as the ratio of the mean squared value estimation at the channel output and the variance of the estimation. Methods Mathematical models are formulated based on three fundamental elements: a motoneuron firing mechanism, motor unit action potential (MUAP module, and signal processor. Myoelectric signals of a motor unit are synthesized with different physiological parameters, and the corresponding SNR of single ME channel is numerically calculated. Effects of physiological multi factors on the SNR are investigated, including properties of the motoneuron, MUAP waveform, recruitment order, and firing pattern, etc. Results The results of the mathematical model, supported by simulation, indicate that the SNR of a single ME channel is associated with the voluntary contraction level. We showed that a model-based approach can provide insight into the key factors and bioprocess in ME control. The results of this modelling work can be potentially used in the improvement of ME control performance and for the training of amputees with powered prostheses. Conclusion The SNR of single ME channel is a force, neuronal and muscular property dependent parameter. The theoretical model provides possible guidance to enhance the SNR of ME channel by controlling physiological variables or conscious contraction level.

  18. 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)

  19. 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

  20. 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.)

  1. Determination of SDI parameters for single crystal AGS

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    1999-01-01

    The responses for 1 and 4 AGS detectectors were compared. It was found that 1 detector reacts approximately as 25% of four detectors. Altitude and angle variations follow the same tendensies whether 1 or 4 detectors are used. Kerma rates equations were compared and discussed. Parameters for calcu...... for calculation of SDI air kerma rate (1 m) were calculated for HMS, KNO3 and 137Cs....

  2. Measurement of lattice parameters of single crystals and thin layers

    Czech Academy of Sciences Publication Activity Database

    Drahokoupil, Jan; Veřtát, P.; Richterová, Kristina; Laufek, František

    2014-01-01

    Roč. 21, č. 2 (2014), s. 97-97 ISSN 1211-5894. [Struktura 2014 : kolokvium Krystalografické společnosti. 09.06.2014-12.06.2014, Kutná Hora] Institutional support: RVO:68378271 Keywords : XRD * lattice parameters Subject RIV: BM - Solid Matter Physics ; Magnetism http://www. xray .cz/ms/bul2014-2/wednesday1.pdf

  3. Donor management parameters and organ yield: single center results.

    Science.gov (United States)

    Marshall, George Ryne; Mangus, Richard S; Powelson, John A; Fridell, Jonathan A; Kubal, Chandrashekhar A; Tector, A Joseph

    2014-09-01

    Management of organ donors in the intensive care unit is an emerging subject in critical care and transplantation. This study evaluates organ yield outcomes for a large number of patients managed by the Indiana Organ Procurement Organization. This is a retrospective review of intensive care unit records from 2008-2012. Donor demographic information and seven donor management parameters (DMP) were recorded at admission, consent, 12 h after consent, and before procurement. Three study groups were created: donors meeting 0-3, 4, or 5-7 DMP. Active donor Organ Procurement Organization management began at consent; so, data analysis focuses on the 12-h postconsent time point. Outcomes included organs transplanted per donor (OTPD) and transplantation of individual solid organs. Complete records for 499 patients were reviewed. Organ yield was 1415 organs of 3992 possible (35%). At 12 h, donors meeting more DMP had more OTPD: 2.2 (0-3) versus 3.0 (4) versus 3.5 (5-7) (P organ except intestine. Oxygen tension, vasopressor use, and central venous pressure were the most frequent independent predictors of organ usage. There were significantly more organs transplanted for donors meeting all three of these parameters (4.5 versus 2.7, P organs, with analysis of individual parameters suggesting that appropriate management of oxygenation, volume status, and vasopressor use could lead to more organs procured per donor. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. 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.

  5. Polar Order and Frustrated Antiferromagnetism in Perovskite Pb2MnWO6 Single Crystals.

    Science.gov (United States)

    Ivanov, Sergey A; Bush, Alexander A; Stash, Adam I; Kamentsev, Konstantin E; Shkuratov, Valerii Ya; Kvashnin, Yaroslav O; Autieri, Carmine; Di Marco, Igor; Sanyal, Biplab; Eriksson, Olle; Nordblad, Per; Mathieu, Roland

    2016-03-21

    Single crystals of the multiferroic double-perovskite Pb2MnWO6 have been synthesized and their structural, thermal, magnetic and dielectric properties studied in detail. Pure perovskite-phase formation and stoichiometric chemical composition of the as-grown crystals are confirmed by X-ray single-crystal and powder diffraction techniques as well as energy-dispersive X-ray and inductively coupled plasma mass spectrometry. Detailed structural analyses reveal that the crystals experience a structural phase transition from the cubic space group (s.g.) Fm3̅m to an orthorhombic structure in s.g. Pn21a at about 460 K. Dielectric data suggest that a ferrielectric phase transition takes place at that same temperature, in contrast to earlier results on polycrystalline samples, which reported a transition to s.g. Pnma and an antiferroelectric low-temperature phase. Magnetic susceptibility measurements indicate that a frustrated antiferromagnetic phase emerges below 8 K. Density functional theory based calculations confirm that the cationic order between Mn and W is favorable. The lowest total energy was found for an antiferromagnetically ordered state. However, analyses of the calculated exchange parameters revealed strongly competing antiferromagnetic interactions. The large distance between the magnetic atoms, together with magnetic frustration, is shown to be the main reason for the low value of the ordering temperature observed experimentally. We discuss the structure-property relationships in Pb2MnWO6 and compare these observations to reported results on related Pb2BWO6 perovskites with different B cations.

  6. 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)

  7. Aerosol water parameterisation: a single parameter framework

    Directory of Open Access Journals (Sweden)

    S. Metzger

    2016-06-01

    Full Text Available We introduce a framework to efficiently parameterise the aerosol water uptake for mixtures of semi-volatile and non-volatile compounds, based on the coefficient, νi. This solute-specific coefficient was introduced in Metzger et al. (2012 to accurately parameterise the single solution hygroscopic growth, considering the Kelvin effect – accounting for the water uptake of concentrated nanometer-sized particles up to dilute solutions, i.e. from the compounds relative humidity of deliquescence (RHD up to supersaturation (Köhler theory. Here we extend the νi parameterisation from single to mixed solutions. We evaluate our framework at various levels of complexity, by considering the full gas–liquid–solid partitioning for a comprehensive comparison with reference calculations using the E-AIM, EQUISOLV II and ISORROPIA II models as well as textbook examples. We apply our parameterisation in the EQuilibrium Simplified Aerosol Model V4 (EQSAM4clim for climate simulations, implemented in a box model and in the global chemistry–climate model EMAC. Our results show (i that the νi approach enables one to analytically solve the entire gas–liquid–solid partitioning and the mixed solution water uptake with sufficient accuracy, (ii that ammonium sulfate mixtures can be solved with a simple method, e.g. pure ammonium nitrate and mixed ammonium nitrate and (iii that the aerosol optical depth (AOD simulations are in close agreement with remote sensing observations for the year 2005. Long-term evaluation of the EMAC results based on EQSAM4clim and ISORROPIA II will be presented separately.

  8. 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.

  9. Comprehensive Wavelengths, Energy Levels, and Hyperfine Structure Parameters of Singly-Ionized Iron-Group Elements

    Science.gov (United States)

    Nave, Gillian

    We propose to measure wavelengths, energy levels, and hyperfine structure parameters of Ni II, Mn II, Sc II and other singly-ionized iron-group elements, covering the wavelength range 80 nm to 5500 nm. We shall use archival data from spectrometers at NIST and Kitt Peak National Observatory for spectra above 140 nm. Additional experimental observations will be taken if needed using Fourier transform spectrometers at NIST. Spectra will be taken using our normal incidence grating spectrograph to provide better sensitivity than the FT spectra and to extend the wavelength range down to 80 nm. We aim to produce a comprehensive description of the spectra of all singly-ionized iron- group elements. The wavelength uncertainty of the strong lines will be better than 1 part in 10^7. For most singly-ionized iron-group elements available laboratory data have uncertainties an order of magnitude larger than astronomical observations over wide spectra ranges. Some of these laboratory measurements date back to the 1960's. Since then, Fourier transform spectroscopy has made significant progress in improving the accuracy and quantity of data in the UV-vis-IR region, but high quality Fourier transform spectra are still needed for Mn II, Ni II and Sc II. Fourier transform spectroscopy has low sensitivity in the VUV region and is limited to wavelengths above 140 nm. Spectra measured with high-resolution grating spectrographs are needed in this region in order to obtain laboratory data of comparable quality to the STIS and COS spectrographs on the Hubble Space Telescope. Currently, such data exist only for Fe II and Cr II. Lines of Sc II, V II, and Mn II show hyperfine structure, but hyperfine structure parameters have been measured for relatively few lines of these elements. Significant errors can occur if hyperfine structure is neglected when abundances are determined from stellar spectra. Measurements of hyperfine structure parameters will be made using Fourier transform spectroscopy

  10. Microstructure evolution to reach the single variant in an ordered Fe–55at.%Pd alloy

    International Nuclear Information System (INIS)

    Farjami, Sahar; Fukuda, Takashi; Kakeshita, Tomoyuki

    2013-01-01

    Highlights: ► We confirmed formation of the single variant in Fe–55at.%Pd by XRD measurement and TEM observation. ► The size of each ordered domain is about 2 nm at the early stage of ordering. ► High density of antiphase boundaries has been observed after formation of the single variant. -- Abstract: Recently, we reported single variant formation in an Fe–55at.%Pd is certainly realized from a disordered fcc-phase to an ordered L1 0 -phase by heat-treatment under magnetic field. In the present study, we have investigated microstructure evolution during the process of the single variant formation by an X-ray diffraction and an electron microscopy observation. As a result, followings are obtained: size of the ordered particles at the early stage of ordering is about 2 nm and the nucleation ratio of preferable variant, whose easy axis lies in the field direction, is higher than that of other variants. Each of the ordered preferable variant grows by consuming the order variants and finally come together to become a single variant. Based on the observation, a model is proposed for the single variant formation of the ordered L1 0 -phase under magnetic field

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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'.

  16. 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

  17. Growth and PhysioChemical Properties of Second-Order Nonlinear Optical L-Threonine Single Crystals

    Directory of Open Access Journals (Sweden)

    G. Ramesh Kumar

    2009-01-01

    Full Text Available The present aim of the paper is to grow and to study the various properties of L-threonine amino acid single crystal in various aspects. Crystal growth of L-threonine single crystals has been carried out with the help of crystallization kinetics. pH and deuteration effects on the properties of the grown crystals have been studied and the results presented in a lucid manner. The various second-order NLO parameters were evaluated using anharmonic oscillator model. Particle and ion irradiation effects on structural, optical, and surface properties of the crystals have also been studied in detail.

  18. Single-order laser high harmonics in XUV for ultrafast photoelectron spectroscopy of molecular wavepacket dynamics

    Directory of Open Access Journals (Sweden)

    Mizuho Fushitani

    2016-11-01

    Full Text Available We present applications of extreme ultraviolet (XUV single-order laser harmonics to gas-phase ultrafast photoelectron spectroscopy. Ultrashort XUV pulses at 80 nm are obtained as the 5th order harmonics of the fundamental laser at 400 nm by using Xe or Kr as the nonlinear medium and separated from other harmonic orders by using an indium foil. The single-order laser harmonics is applied for real-time probing of vibrational wavepacket dynamics of I2 molecules in the bound and dissociating low-lying electronic states and electronic-vibrational wavepacket dynamics of highly excited Rydberg N2 molecules.

  19. Single-order laser high harmonics in XUV for ultrafast photoelectron spectroscopy of molecular wavepacket dynamics.

    Science.gov (United States)

    Fushitani, Mizuho; Hishikawa, Akiyoshi

    2016-11-01

    We present applications of extreme ultraviolet (XUV) single-order laser harmonics to gas-phase ultrafast photoelectron spectroscopy. Ultrashort XUV pulses at 80 nm are obtained as the 5th order harmonics of the fundamental laser at 400 nm by using Xe or Kr as the nonlinear medium and separated from other harmonic orders by using an indium foil. The single-order laser harmonics is applied for real-time probing of vibrational wavepacket dynamics of I 2 molecules in the bound and dissociating low-lying electronic states and electronic-vibrational wavepacket dynamics of highly excited Rydberg N 2 molecules.

  20. 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.

  1. Stability and Hopf Bifurcation of Fractional-Order Complex-Valued Single Neuron Model with Time Delay

    Science.gov (United States)

    Wang, Zhen; Wang, Xiaohong; Li, Yuxia; Huang, Xia

    2017-12-01

    In this paper, the problems of stability and Hopf bifurcation in a class of fractional-order complex-valued single neuron model with time delay are addressed. With the help of the stability theory of fractional-order differential equations and Laplace transforms, several new sufficient conditions, which ensure the stability of the system are derived. Taking the time delay as the bifurcation parameter, Hopf bifurcation is investigated and the critical value of the time delay for the occurrence of Hopf bifurcation is determined. Finally, two representative numerical examples are given to show the effectiveness of the theoretical results.

  2. 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.

  3. 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)

  4. PRACTICAL APPLICATION OF THE SINGLE-PARAMETER SUBCRITICAL MASS LIMIT FOR PLUTONIUM METAL

    Energy Technology Data Exchange (ETDEWEB)

    MITCHELL, MARK VON [Los Alamos National Laboratory

    2007-01-10

    According to ANS-8.1, operations with fissile materials can be performed safely by complying with any of the listed single-parameter subcritical limits. For metallic units, when interspersed moderators are present, the mass limits apply to a single piece having no concave surfaces. On a practical level, when has any operation with fissile metal involved a single piece and absolutely no moderating material, e.g., water, oil, plastic, etc.? This would be rare. This paper explores the application of the single-parameter plutonium metal mass limit for realistic operational environments.

  5. 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.

  6. A Model-Free Diagnostic for Single-Peakedness of Item Responses Using Ordered Conditional Means

    Science.gov (United States)

    Polak, Marike; De Rooij, Mark; Heiser, Willem J.

    2012-01-01

    In this article we propose a model-free diagnostic for single-peakedness (unimodality) of item responses. Presuming a unidimensional unfolding scale and a given item ordering, we approximate item response functions of all items based on ordered conditional means (OCM). The proposed OCM methodology is based on Thurstone & Chave's (1929) "criterion…

  7. 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.

  8. 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.

  9. 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),...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Parameter Optimization of Single-Diode Model of Photovoltaic Cell Using Memetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yourim Yoon

    2015-01-01

    Full Text Available This study proposes a memetic approach for optimally determining the parameter values of single-diode-equivalent solar cell model. The memetic algorithm, which combines metaheuristic and gradient-based techniques, has the merit of good performance in both global and local searches. First, 10 single algorithms were considered including genetic algorithm, simulated annealing, particle swarm optimization, harmony search, differential evolution, cuckoo search, least squares method, and pattern search; then their final solutions were used as initial vectors for generalized reduced gradient technique. From this memetic approach, we could further improve the accuracy of the estimated solar cell parameters when compared with single algorithm approaches.

  18. 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

  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?

    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.

  20. Ordered array of CoPc-vacancies filled with single-molecule rotors

    Science.gov (United States)

    Xie, Zheng-Bo; Wang, Ya-Li; Tao, Min-Long; Sun, Kai; Tu, Yu-Bing; Yuan, Hong-Kuan; Wang, Jun-Zhong

    2018-05-01

    We report the highly ordered array of CoPc-vacancies and the single-molecule rotors inside the vacancies. When CoPc molecules are deposited on Cd(0001) at low-temperature, three types of molecular vacancies appeared randomly in the CoPc monolayer. Annealing the sample to higher temperature leads to the spontaneous phase separation and self-organized arrangement of the vacancies. Highly ordered arrays of two-molecule vacancies and single-molecule vacancies have been obtained. In particular, there is a rotating CoPc molecule inside each single-molecule vacancy, which constitutes the array of single-molecule rotors. These results provide a new routine to fabricate the nano-machines on a large scale.

  1. 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

  2. Dynamical Analysis on Single Degree-of-Freedom Semiactive Control System by Using Fractional-Order Derivative

    Directory of Open Access Journals (Sweden)

    Yongjun Shen

    2015-01-01

    Full Text Available The single degree-of-freedom (SDOF system under the control of three semiactive methods is analytically studied in this paper, where a fractional-order derivative is used in the mathematical model. The three semiactive control methods are on-off control, limited relative displacement (LRD control, and relative control, respectively. The averaging method is adopted to provide an analytical study on the performance of the three different control methods. Based on the comparison between the analytical solutions with the numerical ones, it could be proved that the analytical solutions are accurate enough. The effects of the fractional-order parameters on the control performance, especially the relative and absolute displacement transmissibility, are analyzed. The research results indicate that the steady-state amplitudes of the three semiactive systems with fractional-order derivative in the model could be significantly reduced and the control performance can be greatly improved.

  3. 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.

  4. 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)

  5. Single image super-resolution using self-optimizing mask via fractional-order gradient interpolation and reconstruction.

    Science.gov (United States)

    Yang, Qi; Zhang, Yanzhu; Zhao, Tiebiao; Chen, YangQuan

    2017-04-04

    Image super-resolution using self-optimizing mask via fractional-order gradient interpolation and reconstruction aims to recover detailed information from low-resolution images and reconstruct them into high-resolution images. Due to the limited amount of data and information retrieved from low-resolution images, it is difficult to restore clear, artifact-free images, while still preserving enough structure of the image such as the texture. This paper presents a new single image super-resolution method which is based on adaptive fractional-order gradient interpolation and reconstruction. The interpolated image gradient via optimal fractional-order gradient is first constructed according to the image similarity and afterwards the minimum energy function is employed to reconstruct the final high-resolution image. Fractional-order gradient based interpolation methods provide an additional degree of freedom which helps optimize the implementation quality due to the fact that an extra free parameter α-order is being used. The proposed method is able to produce a rich texture detail while still being able to maintain structural similarity even under large zoom conditions. Experimental results show that the proposed method performs better than current single image super-resolution techniques. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  6. 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.

  7. 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.

  8. 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.

  9. The effects of isolated single umbilical artery on first and second trimester aneuploidy screening test parameters.

    Science.gov (United States)

    Tulek, Firat; Kahraman, Alper; Taskin, Salih; Ozkavukcu, Esra; Soylemez, Feride

    2015-04-01

    Reliability of first and second trimester screening tests largely depends on accurate estimation of maternal serum marker values. Reduced reliability could lead redundant invasive tests or misdiagnosis. Adjustments of serum marker values for confounding factors like insulin-dependent diabetes, maternal weight or maternal rhesus status are essential. We aimed to investigate whether isolated single umbilical artery alters first and second trimester test parameters or not. Routine detailed obstetric ultrasonographies performed were retrospectively screened for this study. Among spontaneously conceived singleton pregnancies, women who were found to have single umbilical artery without any additional structural anomalies or aneuploidies were selected. First and second trimester screening test results were accessible for 98 and 102 of the cases with isolated single umbilical artery, respectively. Among first trimester screening test parameters, PAPP-A (pregnancy-associated plasma protein A) MoMs were found significantly higher in isolated single umbilical artery group. AFP MoMs were found significantly elevated in isolated single umbilical artery group in second trimester quadruple tests. Existence of single umbilical artery could alter the estimation of MoM values of maternal serum markers. Reliability of prenatal screening tests could be improved by adjusting these parameters in accordance with isolated single umbilical artery.

  10. Single-parameter scaling and maximum entropy inside disordered one-dimensional systems: Theory and experiment

    Science.gov (United States)

    Cheng, Xiaojun; Ma, Xujun; Yépez, Miztli; Genack, Azriel Z.; Mello, Pier A.

    2017-11-01

    The single-parameter scaling hypothesis relating the average and variance of the logarithm of the conductance is a pillar of the theory of electronic transport. We use a maximum-entropy ansatz to explore the logarithm of the particle, or energy density lnW (x ) at a depth x into a random one-dimensional system. Single-parameter scaling would be the special case in which x =L (the system length). We find the result, confirmed in microwave measurements and computer simulations, that the average of lnW (x ) is independent of L and equal to -x /ℓ , with ℓ the mean free path. At the beginning of the sample, var [lnW (x )] rises linearly with x and is also independent of L , with a sublinear increase and then a drop near the sample output. At x =L we find a correction to the value of var [lnT ] predicted by single-parameter scaling.

  11. Persistent Charge-Density-Wave Order in Single-Layer TaSe2.

    Science.gov (United States)

    Ryu, Hyejin; Chen, Yi; Kim, Heejung; Tsai, Hsin-Zon; Tang, Shujie; Jiang, Juan; Liou, Franklin; Kahn, Salman; Jia, Caihong; Omrani, Arash A; Shim, Ji Hoon; Hussain, Zahid; Shen, Zhi-Xun; Kim, Kyoo; Min, Byung Il; Hwang, Choongyu; Crommie, Michael F; Mo, Sung-Kwan

    2018-02-14

    We present the electronic characterization of single-layer 1H-TaSe 2 grown by molecular beam epitaxy using a combined angle-resolved photoemission spectroscopy, scanning tunneling microscopy/spectroscopy, and density functional theory calculations. We demonstrate that 3 × 3 charge-density-wave (CDW) order persists despite distinct changes in the low energy electronic structure highlighted by the reduction in the number of bands crossing the Fermi energy and the corresponding modification of Fermi surface topology. Enhanced spin-orbit coupling and lattice distortion in the single-layer play a crucial role in the formation of CDW order. Our findings provide a deeper understanding of the nature of CDW order in the two-dimensional limit.

  12. Kinetic parameter estimation and fluctuation analysis of CO at SnO2 single nanowires.

    Science.gov (United States)

    Tulzer, Gerhard; Baumgartner, Stefan; Brunet, Elise; Mutinati, Giorgio C; Steinhauer, Stephan; Köck, Anton; Barbano, Paolo E; Heitzinger, Clemens

    2013-08-09

    In this work, we present calculated numerical values for the kinetic parameters governing adsorption/desorption processes of carbon monoxide at tin dioxide single-nanowire gas sensors. The response of such sensors to pulses of 50 ppm carbon monoxide in nitrogen is investigated at different temperatures to extract the desired information. A rate-equation approach is used to model the reaction kinetics, which results in the problem of determining coefficients in a coupled system of nonlinear ordinary differential equations. The numerical values are computed by inverse-modeling techniques and are then used to simulate the sensor response. With our model, the dynamic response of the sensor due to the gas-surface interaction can be studied in order to find the optimal setup for detection, which is an important step towards selectivity of these devices. We additionally investigate the noise in the current through the nanowire and its changes due to the presence of carbon monoxide in the sensor environment. Here, we propose the use of a wavelet transform to decompose the signal and analyze the noise in the experimental data. This method indicates that some fluctuations are specific for the gas species investigated here.

  13. Kinetic parameter estimation and fluctuation analysis of CO at SnO 2 single nanowires

    KAUST Repository

    Tulzer, Gerhard

    2013-07-12

    In this work, we present calculated numerical values for the kinetic parameters governing adsorption/desorption processes of carbon monoxide at tin dioxide single-nanowire gas sensors. The response of such sensors to pulses of 50 ppm carbon monoxide in nitrogen is investigated at different temperatures to extract the desired information. A rate-equation approach is used to model the reaction kinetics, which results in the problem of determining coefficients in a coupled system of nonlinear ordinary differential equations. The numerical values are computed by inverse-modeling techniques and are then used to simulate the sensor response. With our model, the dynamic response of the sensor due to the gas-surface interaction can be studied in order to find the optimal setup for detection, which is an important step towards selectivity of these devices. We additionally investigate the noise in the current through the nanowire and its changes due to the presence of carbon monoxide in the sensor environment. Here, we propose the use of a wavelet transform to decompose the signal and analyze the noise in the experimental data. This method indicates that some fluctuations are specific for the gas species investigated here. © 2013 IOP Publishing Ltd.

  14. Multi-Axis Identifiability Using Single-Surface Parameter Estimation Maneuvers on the X-48B Blended Wing Body

    Science.gov (United States)

    Ratnayake, Nalin A.; Koshimoto, Ed T.; Taylor, Brian R.

    2011-01-01

    The problem of parameter estimation on hybrid-wing-body type aircraft is complicated by the fact that many design candidates for such aircraft involve a large number of aero- dynamic control effectors that act in coplanar motion. This fact adds to the complexity already present in the parameter estimation problem for any aircraft with a closed-loop control system. Decorrelation of system inputs must be performed in order to ascertain individual surface derivatives with any sort of mathematical confidence. Non-standard control surface configurations, such as clamshell surfaces and drag-rudder modes, further complicate the modeling task. In this paper, asymmetric, single-surface maneuvers are used to excite multiple axes of aircraft motion simultaneously. Time history reconstructions of the moment coefficients computed by the solved regression models are then compared to each other in order to assess relative model accuracy. The reduced flight-test time required for inner surface parameter estimation using multi-axis methods was found to come at the cost of slightly reduced accuracy and statistical confidence for linear regression methods. Since the multi-axis maneuvers captured parameter estimates similar to both longitudinal and lateral-directional maneuvers combined, the number of test points required for the inner, aileron-like surfaces could in theory have been reduced by 50%. While trends were similar, however, individual parameters as estimated by a multi-axis model were typically different by an average absolute difference of roughly 15-20%, with decreased statistical significance, than those estimated by a single-axis model. The multi-axis model exhibited an increase in overall fit error of roughly 1-5% for the linear regression estimates with respect to the single-axis model, when applied to flight data designed for each, respectively.

  15. 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).

  16. Organic and inorganic solar cells parameters evaluation from single I-V plot

    International Nuclear Information System (INIS)

    Chegaar, M.; Nehaoua, N.; Bouhemadou, A.

    2008-01-01

    This paper presents a new method to determine the five solar cell parameters of the single diode lumped circuit model. These parameters are usually the saturation current, the series resistance, the ideality factor, the shunt conductance and the photocurrent. This method is based on the measured current-voltage data. The method has been successfully applied to a commercial silicon solar cell, a module and an organic solar cell

  17. Estimation of single plane unbalance parameters of a rotor-bearing system using Kalman filtering based force estimation technique

    Science.gov (United States)

    Shrivastava, Akash; Mohanty, A. R.

    2018-03-01

    This paper proposes a model-based method to estimate single plane unbalance parameters (amplitude and phase angle) in a rotor using Kalman filter and recursive least square based input force estimation technique. Kalman filter based input force estimation technique requires state-space model and response measurements. A modified system equivalent reduction expansion process (SEREP) technique is employed to obtain a reduced-order model of the rotor system so that limited response measurements can be used. The method is demonstrated using numerical simulations on a rotor-disk-bearing system. Results are presented for different measurement sets including displacement, velocity, and rotational response. Effects of measurement noise level, filter parameters (process noise covariance and forgetting factor), and modeling error are also presented and it is observed that the unbalance parameter estimation is robust with respect to measurement noise.

  18. Exploring Electronic Structure and Order in Polymers via Single-Particle Microresonator Spectroscopy.

    Science.gov (United States)

    Horak, Erik H; Rea, Morgan T; Heylman, Kevin D; Gelbwaser-Klimovsky, David; Saikin, Semion K; Thompson, Blaise J; Kohler, Daniel D; Knapper, Kassandra A; Wei, Wei; Pan, Feng; Gopalan, Padma; Wright, John C; Aspuru-Guzik, Alán; Goldsmith, Randall H

    2018-02-08

    PSS, a transparent electrically conductive polymer, finds widespread use in electronic devices. While empirical efforts have increased conductivity, a detailed understanding of the coupled electronic and morphological landscapes in PEDOT:PSS has lagged due to substantial structural heterogeneity on multiple length-scales. We use an optical microresonator-based absorption spectrometer to perform single-particle measurements, providing a bottom-up examination of electronic structure and morphology ranging from single PEDOT:PSS polymers to nascent films. Using single-particle spectroscopy with complementary theoretical calculations and ultrafast spectroscopy, we demonstrate that PEDOT:PSS displays bulk-like optical response even in single polymers. We find highly ordered PEDOT assemblies with long-range ordering mediated by the insulating PSS matrix and reveal a preferential surface orientation of PEDOT nanocrystallites absent in bulk films with implications for interfacial electronic communication. Our single-particle perspective provides a unique window into the microscopic structure and electronic properties of PEDOT:PSS.

  19. 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)

  20. Single DV-DXCCII Based Voltage Controlled First Order All-pass Filter with Inverting and Non-inverting responses

    Directory of Open Access Journals (Sweden)

    B Chaturvedi

    2015-12-01

    Full Text Available In this paper, a new voltage controlled first order all-pass filter is presented. The proposed circuit employs a single differential voltage dual-X second generation current conveyor (DV-DXCCII and a grounded capacitor only. The proposed all-pass filter provides both inverting and non inverting voltage-mode outputs from the same configuration simultaneously without any matching condition. Non-ideal analysis along with sensitivity analysis is also investigated. The proposed circuit has low active and passive sensitivities. As an application the proposed all-pass filter is connected in cascade to get higher order filter. The theoretical results are validated thorough PSPICE simulations using TSMC 0.18µm CMOS process parameters.

  1. 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)...

  2. 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...

  3. Sensitivity of the amplitude of the single muscle fibre action potential to microscopic volume conduction parameters

    NARCIS (Netherlands)

    Alberts, B.A.; Rutten, Wim; Wallinga, W.; Boom, H.B.K.

    1988-01-01

    A microscopic model of volume conduction was applied to examine the sensitivity of the single muscle fibre action potential to variations in parameters of the source and of the volume conductor, such as conduction velocity, intracellular conductivity and intracellular volume fraction. The model

  4. Determination of Kinetic Parameters within a Single Nonisothermal On-Flow Experiment by Nanoliter NMR Spectroscopy

    NARCIS (Netherlands)

    Gomez, M.V.; Rodriguez, A.M.; Hoz, de la A.; Jimenez-Marquez, F.; Fratila, R.M.; Barneveld, P.A.; Velders, A.H.

    2015-01-01

    Conventional methods to determine the kinetic parameters for a certain reaction require multiple, separate isothermal experiments, resulting in time- and material-consuming processes. Here, an approach to determine the kinetic information within a single nonisothermal on-flow experiment is

  5. A double parameters measurement of steam-water two-phase flow with single orifice

    International Nuclear Information System (INIS)

    Zhong Shuoping; Tong Yunxian; Yu Meiying

    1992-08-01

    A double parameters measurement of steam-water two-phase flow with single orifice is described. An on-line measurement device based on micro-computer has been developed. The measured r.m.s error of steam quality is less than 6.5% and the measured relative r.m.s. error of mass flow rate is less than 9%

  6. Feasibility of a single-parameter description of equilibrium viscous liquid dynamics

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Christensen, Tage Emil; Schrøder, Thomas

    2008-01-01

    -Andersen binary Lennard-Jones mixture as well as for an asymmetric dumbbell model liquid, a single-parameter description works quite well. This is confirmed by time-domain results where it is found that energy and pressure fluctuations are strongly correlated on the alpha time scale in the constant...

  7. Single attosecond pulse from terahertz-assisted high-order harmonic generation

    Science.gov (United States)

    Balogh, Emeric; Kovacs, Katalin; Dombi, Peter; Fulop, Jozsef A.; Farkas, Gyozo; Hebling, Janos; Tosa, Valer; Varju, Katalin

    2011-08-01

    High-order harmonic generation by few-cycle 800 nm laser pulses in neon gas in the presence of a strong terahertz (THz) field is investigated numerically with propagation effects taken into account. Our calculations show that the combination of THz fields with up to 12 fs laser pulses can be an effective gating technique to generate single attosecond pulses. We show that in the presence of the strong THz field only a single attosecond burst can be phase matched, whereas radiation emitted during other half cycles disappears during propagation. The cutoff is extended and a wide supercontinuum appears in the near-field spectra, extending the available spectral width for isolated attosecond pulse generation from 23 to 93 eV. We demonstrate that phase-matching effects are responsible for the generation of isolated attosecond pulses, even in conditions when single-atom response yields an attosecond pulse train.

  8. Single attosecond pulse from terahertz-assisted high-order harmonic generation

    International Nuclear Information System (INIS)

    Balogh, Emeric; Kovacs, Katalin; Dombi, Peter; Farkas, Gyozo; Fulop, Jozsef A.; Hebling, Janos; Tosa, Valer; Varju, Katalin

    2011-01-01

    High-order harmonic generation by few-cycle 800 nm laser pulses in neon gas in the presence of a strong terahertz (THz) field is investigated numerically with propagation effects taken into account. Our calculations show that the combination of THz fields with up to 12 fs laser pulses can be an effective gating technique to generate single attosecond pulses. We show that in the presence of the strong THz field only a single attosecond burst can be phase matched, whereas radiation emitted during other half cycles disappears during propagation. The cutoff is extended and a wide supercontinuum appears in the near-field spectra, extending the available spectral width for isolated attosecond pulse generation from 23 to 93 eV. We demonstrate that phase-matching effects are responsible for the generation of isolated attosecond pulses, even in conditions when single-atom response yields an attosecond pulse train.

  9. Single attosecond pulse from terahertz-assisted high-order harmonic generation

    Energy Technology Data Exchange (ETDEWEB)

    Balogh, Emeric [Department of Optics and Quantum Electronics, University of Szeged, H-6701 Szeged (Hungary); Kovacs, Katalin [Department of Optics and Quantum Electronics, University of Szeged, H-6701 Szeged (Hungary); National Institute for R and D of Isotopic and Molecular Technologies, RO-400293 Cluj-Napoca (Romania); Dombi, Peter; Farkas, Gyozo [Research Institute for Solid State Physics and Optics, H-1525 Budapest (Hungary); Fulop, Jozsef A.; Hebling, Janos [Department of Experimental Physics, University of Pecs, H-7624 Pecs (Hungary); Tosa, Valer [National Institute for R and D of Isotopic and Molecular Technologies, RO-400293 Cluj-Napoca (Romania); Varju, Katalin [HAS Research Group on Laser Physics, University of Szeged, H-6701 Szeged (Hungary)

    2011-08-15

    High-order harmonic generation by few-cycle 800 nm laser pulses in neon gas in the presence of a strong terahertz (THz) field is investigated numerically with propagation effects taken into account. Our calculations show that the combination of THz fields with up to 12 fs laser pulses can be an effective gating technique to generate single attosecond pulses. We show that in the presence of the strong THz field only a single attosecond burst can be phase matched, whereas radiation emitted during other half cycles disappears during propagation. The cutoff is extended and a wide supercontinuum appears in the near-field spectra, extending the available spectral width for isolated attosecond pulse generation from 23 to 93 eV. We demonstrate that phase-matching effects are responsible for the generation of isolated attosecond pulses, even in conditions when single-atom response yields an attosecond pulse train.

  10. Deuteron NMR resolved mesogen vs. crosslinker molecular order and reorientational exchange in liquid single crystal elastomers

    Czech Academy of Sciences Publication Activity Database

    Milavec, J.; Domenici, V.; Zupančič, B.; Rešetič, A.; Bubnov, Alexej; Zalar, B.

    2016-01-01

    Roč. 18, č. 5 (2016), s. 4071-4077 ISSN 1463-9076 R&D Projects: GA ČR GA15-02843S; GA MŠk(CZ) LD14007 Grant - others:EU - ICT(XE) COST Action IC1208 Institutional support: RVO:68378271 Keywords : liquid single crystal elastomer * NMR * liquid crystal * molecular order * monomers Subject RIV: JJ - Other Materials Impact factor: 4.123, year: 2016

  11. 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.

  12. 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

  13. Inertial-ordering-assisted droplet microfluidics for high-throughput single-cell RNA-sequencing.

    Science.gov (United States)

    Moon, Hui-Sung; Je, Kwanghwi; Min, Jae-Woong; Park, Donghyun; Han, Kyung-Yeon; Shin, Seung-Ho; Park, Woong-Yang; Yoo, Chang Eun; Kim, Shin-Hyun

    2018-02-27

    Single-cell RNA-seq reveals the cellular heterogeneity inherent in the population of cells, which is very important in many clinical and research applications. Recent advances in droplet microfluidics have achieved the automatic isolation, lysis, and labeling of single cells in droplet compartments without complex instrumentation. However, barcoding errors occurring in the cell encapsulation process because of the multiple-beads-in-droplet and insufficient throughput because of the low concentration of beads for avoiding multiple-beads-in-a-droplet remain important challenges for precise and efficient expression profiling of single cells. In this study, we developed a new droplet-based microfluidic platform that significantly improved the throughput while reducing barcoding errors through deterministic encapsulation of inertially ordered beads. Highly concentrated beads containing oligonucleotide barcodes were spontaneously ordered in a spiral channel by an inertial effect, which were in turn encapsulated in droplets one-by-one, while cells were simultaneously encapsulated in the droplets. The deterministic encapsulation of beads resulted in a high fraction of single-bead-in-a-droplet and rare multiple-beads-in-a-droplet although the bead concentration increased to 1000 μl -1 , which diminished barcoding errors and enabled accurate high-throughput barcoding. We successfully validated our device with single-cell RNA-seq. In addition, we found that multiple-beads-in-a-droplet, generated using a normal Drop-Seq device with a high concentration of beads, underestimated transcript numbers and overestimated cell numbers. This accurate high-throughput platform can expand the capability and practicality of Drop-Seq in single-cell analysis.

  14. Single-mirror beam steering system: analysis and synthesis of high-order conic-section scan patterns

    Science.gov (United States)

    Li, Yajun

    2008-01-01

    The vector approach introduced in an early paper for modeling mirror-scanning devices [Y. Li, Appl. Opt. 34, 6417 (1995)] provides the basis of a rigorous study of the scan field generated by a single-mirror beam steering system, in which a hinged movable mirror is able to turn about a fixed pivot point to steering a single laser beam. Because of fewer constraints on mirror angular motion, the system may behave like a true point source for both vector and raster scanning applications. After a summary of the expressions for scan fields generated under different conditions, some fundamental and advanced topics of the single-mirror system are addressed: (1) basic parameters of high-order conic-section scan patterns, (2) scanning spot kinematics, (3) effect of input offset and pixels distortions on two-dimensional images displayed on screens of different formats, (4) mapping and its inverse between the mirror vector space and the scan vector space, and (5) single-mirror beam steering system as a one-element reflective and continuous image zooming device.

  15. 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.

  16. A single dose of oxytocin nasal spray improves higher-order social cognition in schizophrenia.

    Science.gov (United States)

    Guastella, Adam J; Ward, Philip B; Hickie, Ian B; Shahrestani, Sara; Hodge, Marie Antoinette Redoblado; Scott, Elizabeth M; Langdon, Robyn

    2015-11-01

    Schizophrenia is associated with significant impairments in both higher and lower order social cognitive performance and these impairments contribute to poor social functioning. People with schizophrenia report poor social functioning to be one of their greatest unmet treatment needs. Recent studies have suggested the potential of oxytocin as such a treatment, but mixed results render it uncertain what aspects of social cognition are improved by oxytocin and, subsequently, how oxytocin might best be applied as a therapeutic. The aim of this study was to determine whether a single dose of oxytocin improved higher-order and lower-order social cognition performance for patients with schizophrenia across a well-established battery of social cognition tests. Twenty-one male patients received both a single dose of oxytocin nasal spray (24IU) and a placebo, two weeks apart in a randomized within-subjects placebo controlled design. Following each administration, participants completed the social cognition tasks, as well as a test of general neurocognition. Results revealed that oxytocin particularly enhanced performance on higher order social cognition tasks, with no effects on general neurocognition. Results for individual tasks showed most improvement on tests measuring appreciation of indirect hints and recognition of social faux pas. These results suggest that oxytocin, if combined to enhance social cognition learning, may be beneficial when targeted at higher order social cognition domains. This study also suggests that these higher order tasks, which assess social cognitive processing in a social communication context, may provide useful markers of response to oxytocin in schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Optimization and Modeling of Quadrupole Orbitrap Parameters for Sensitive Analysis toward Single-Cell Proteomics.

    Science.gov (United States)

    Sun, Bingyun; Kovatch, Jessica Rae; Badiong, Albert; Merbouh, Nabyl

    2017-10-06

    Single-cell proteomics represents a field of extremely sensitive proteomic analysis, owing to the minute amount of yet complex proteins in a single cell. Without amplification potential as of nucleic acids, single-cell mass spectrometry (MS) analysis demands special instrumentation running with optimized parameters to maximize the sensitivity and throughput for comprehensive proteomic discovery. To facilitate such analysis, we here investigated two factors critical to peptide sequencing and protein detection in shotgun proteomics, i.e. precursor ion isolation window (IW) and maximum precursor ion injection time (ITmax), on an ultrahigh-field quadrupole Orbitrap (Q-Exactive HF). Counterintuitive to the frequently used proteomic parameters for bulk samples (>100 ng), our experimental data and subsequent modeling suggested a universally optimal IW of 4.0 Th for sample quantity ranging from 100 ng to 1 ng, and a sample-quantity dependent ITmax of more than 250 ms for 1-ng samples. Compared with the benchmark condition of IW = 2.0 Th and ITmax = 50 ms, our optimization generated up to 300% increase to the detected protein groups for 1-ng samples. The additionally identified proteins allowed deeper penetration of proteome for better revealing crucial cellular functions such as signaling and cell adhesion. We hope this effort can prompt single-cell and trace proteomic analysis and enable a rational selection of MS parameters.

  18. Production of Single W Bosons at LEP and Measurement of $WW\\gamma$ Gauge Coupling Parameters

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, Michael; Doria, A; Dova, M T; Duchesneau, D; Echenard, B; Eline, A; El-Mamouni, H; Engler, A; Eppling, F J; Ewers, A; Extermann, Pierre; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hakobyan, R S; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Palomares, C; Pandoulas, D; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, Juan Antonio; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S V; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R P; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wallraff, W; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2002-01-01

    \\documentclass[12pt,a4paper,dvips]{article} \\begin{document} \\begin{center} {Production of Single W Bosons at LEP and \\\\ Measurement of \\boldmath$\\rm W W \\gamma$ Gauge Coupling Parameters} \\end{center} \\begin{abstract} Single W boson production in electron-positron collisions is studied with the L3 detector at centre-of-mass energies between $192\\mathrm{\\ Ge\\kern -0.1em V}$ and $209\\mathrm{\\ Ge\\kern -0.1em V}$. Events with two acoplanar hadronic jets or a single energetic lepton are selected, and the single W cross section is measured. Combining the results with measurements at lower centre-of-mass energies, the ratio of the measured cross section to the Standard Model expectation is found to be $1.12^{+0.11}_{-0.10}\\pm0.03$. From all single W data, the WW$\\gamma$ gauge coupling parameter $\\kappa_\\gamma$ is measured to be $1.116^{+0.082}_{-0.086}\\pm0.068$. \\end{abstract} \\end{document}

  19. A Russian Dolls ordering of the Hadamard basis for compressive single-pixel imaging.

    Science.gov (United States)

    Sun, Ming-Jie; Meng, Ling-Tong; Edgar, Matthew P; Padgett, Miles J; Radwell, Neal

    2017-06-14

    Single-pixel imaging is an alternate imaging technique particularly well-suited to imaging modalities such as hyper-spectral imaging, depth mapping, 3D profiling. However, the single-pixel technique requires sequential measurements resulting in a trade-off between spatial resolution and acquisition time, limiting real-time video applications to relatively low resolutions. Compressed sensing techniques can be used to improve this trade-off. However, in this low resolution regime, conventional compressed sensing techniques have limited impact due to lack of sparsity in the datasets. Here we present an alternative compressed sensing method in which we optimize the measurement order of the Hadamard basis, such that at discretized increments we obtain complete sampling for different spatial resolutions. In addition, this method uses deterministic acquisition, rather than the randomized sampling used in conventional compressed sensing. This so-called 'Russian Dolls' ordering also benefits from minimal computational overhead for image reconstruction. We find that this compressive approach performs as well as other compressive sensing techniques with greatly simplified post processing, resulting in significantly faster image reconstruction. Therefore, the proposed method may be useful for single-pixel imaging in the low resolution, high-frame rate regime, or video-rate acquisition.

  20. Approaching nominal longitudinal parameters with a single LHC batch in the SPS

    CERN Document Server

    Baudrenghien, P; Linnecar, Trevor Paul R; Shaposhnikova, Elena; Tückmantel, Joachim; CERN. Geneva. SPS and LHC Division

    2002-01-01

    Progress made in obtaining the nominal LHC parameters during the first three MDs in 2002 is described. At the end of the third MD nominal longitudinal parameters (bunch length 1.75 ns and emittance 0.46 eVs) were obtained for a single batch with an intensity of 6.7 x 1012 at 450 GeV as a result of improvements in the feedback and feedforward systems made in the second MD and special settings, which include an optimised 200 MHz voltage programme, operation of the 800 MHz RF system through the cycle together with a small controlled emittance blow-up on the flat bottom.

  1. Investigation of snow single scattering properties based on first order Legendre phase function

    Science.gov (United States)

    Eppanapelli, Lavan Kumar; Casselgren, Johan; Wåhlin, Johan; Sjödahl, Mikael

    2017-04-01

    Angularly resolved bidirectional reflectance measurements were modelled by approximating a first order Legendre expanded phase function to retrieve single scattering properties of snow. The measurements from 10 different snow types with known density and specific surface area (SSA) were investigated. A near infrared (NIR) spectrometer was used to measure reflected light above the snow surface over the hemisphere in the wavelength region of 900-1650 nm. A solver based on discrete ordinate radiative transfer (DISORT) model was used to retrieve the estimated Legendre coefficients of the phase function and a correlation between the coefficients and physical properties of different snow types is investigated. Results of this study suggest that the first two coefficients of the first order Legendre phase function provide sufficient information about the physical properties of snow where the latter captures the anisotropic behaviour of snow and the former provides a relative estimate of the single scattering albedo of snow. The coefficients of the first order phase function were compared with the experimental data and observed that both the coefficients are in good agreement with the experimental data. These findings suggest that our approach can be applied as a qualitative tool to investigate physical properties of snow and also to classify different snow types.

  2. Impact of Intragranular Substructure Parameters on the Forming Limit Diagrams of Single-Phase B.C.C. Steels

    Directory of Open Access Journals (Sweden)

    Gérald Franz

    2013-11-01

    Full Text Available An advanced elastic-plastic self-consistent polycrystalline model, accounting for intragranular microstructure development and evolution, is coupled with a bifurcation-based localization criterion and applied to the numerical investigation of the impact of microstructural patterns on ductility of single-phase steels. The proposed multiscale model, taking into account essential microstructural aspects, such as initial and induced textures, dislocation densities, and softening mechanisms, allows us to emphasize the relationship between intragranular microstructure of B.C.C. steels and their ductility. A qualitative study in terms of forming limit diagrams for various dislocation networks, during monotonic loading tests, is conducted in order to analyze the impact of intragranular substructure parameters on the formability of single-phase B.C.C. steels.

  3. 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.

  4. 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

  5. Dynamical Tangles in Third-Order Oscillator with Single Jump Function

    Directory of Open Access Journals (Sweden)

    Jiří Petržela

    2014-01-01

    Full Text Available This contribution brings a deep and detailed study of the dynamical behavior associated with nonlinear oscillator described by a single third-order differential equation with scalar jump nonlinearity. The relative primitive geometry of the vector field allows making an exhaustive numerical analysis of its possible solutions, visualizations of the invariant manifolds, and basins of attraction as well as proving the existence of chaotic motion by using the concept of both Shilnikov theorems. The aim of this paper is also to complete, carry out and link the previous works on simple Newtonian dynamics, and answer the question how individual types of the phenomenon evolve with time via understandable notes.

  6. First-order aerodynamic and aeroelastic behavior of a single-blade installation setup

    DEFF Research Database (Denmark)

    Gaunaa, Mac; Bergami, Leonardo; Guntur, Srinivas

    2014-01-01

    the first-order aerodynamic and aeroelastic behavior of a single blade installation system, where the blade is grabbed by a yoke, which is lifted by the crane and stabilized by two taglines. A simple engineering model is formulated to describe the aerodynamic forcing on the blade subject to turbulent wind...... of arbitrary direction. The model is coupled with a schematic aeroelastic representation of the taglines system, which returns the minimum line tension required to compensate for the aerodynamic forcing. The simplified models are in excellent agreement with the aeroelastic code HAWC2, and provide a solid basis...

  7. A split-optimization approach for obtaining multiple solutions in single-objective process parameter optimization.

    Science.gov (United States)

    Rajora, Manik; Zou, Pan; Yang, Yao Guang; Fan, Zhi Wen; Chen, Hung Yi; Wu, Wen Chieh; Li, Beizhi; Liang, Steven Y

    2016-01-01

    It can be observed from the experimental data of different processes that different process parameter combinations can lead to the same performance indicators, but during the optimization of process parameters, using current techniques, only one of these combinations can be found when a given objective function is specified. The combination of process parameters obtained after optimization may not always be applicable in actual production or may lead to undesired experimental conditions. In this paper, a split-optimization approach is proposed for obtaining multiple solutions in a single-objective process parameter optimization problem. This is accomplished by splitting the original search space into smaller sub-search spaces and using GA in each sub-search space to optimize the process parameters. Two different methods, i.e., cluster centers and hill and valley splitting strategy, were used to split the original search space, and their efficiency was measured against a method in which the original search space is split into equal smaller sub-search spaces. The proposed approach was used to obtain multiple optimal process parameter combinations for electrochemical micro-machining. The result obtained from the case study showed that the cluster centers and hill and valley splitting strategies were more efficient in splitting the original search space than the method in which the original search space is divided into smaller equal sub-search spaces.

  8. 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.

  9. Spiro-OMeTAD single crystals: Remarkably enhanced charge-carrier transport via mesoscale ordering

    KAUST Repository

    Shi, Dong

    2016-04-15

    We report the crystal structure and hole-transport mechanism in spiro-OMeTAD [2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene], the dominant hole-transporting material in perovskite and solid-state dye-sensitized solar cells. Despite spiro-OMeTAD’s paramount role in such devices, its crystal structure was unknown because of highly disordered solution-processed films; the hole-transport pathways remained ill-defined and the charge carrier mobilities were low, posing a major bottleneck for advancing cell efficiencies. We devised an antisolvent crystallization strategy to grow single crystals of spiro-OMeTAD, which allowed us to experimentally elucidate its molecular packing and transport properties. Electronic structure calculations enabled us to map spiro-OMeTAD’s intermolecular charge-hopping pathways. Promisingly, single-crystal mobilities were found to exceed their thin-film counterparts by three orders of magnitude. Our findings underscore mesoscale ordering as a key strategy to achieving breakthroughs in hole-transport material engineering of solar cells.

  10. 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 ...

  11. Magnetic order and lattice distortion in Rh- and Cu-doped BaFe2As2 single crystals

    Science.gov (United States)

    Kreyssig, A.; Kim, M. G.; Nandi, S.; Tian, W.; Zarestky, J.; Thaler, A.; Ni, N.; Bud'Ko, S. L.; Canfield, P. C.; McQueeney, R. J.; Goldman, A. I.

    2010-03-01

    Recent investigations of superconducting Co-doped BaFe2As2 have highlighted the interplay between superconductivity, magnetism and structure. Here we report on the antiferromagnetic order, lattice distortion and their response to superconductivity in Rh-doped BaFe2As2 and compare the behavior with non-superconducting Cu-doped BaFe2As2 single crystals. Results of the neutron scattering experiment performed at HB1A, HFIR, Oak Ridge, are correlated with high-resolution x-ray diffraction, resistance and magnetization measurements. The magnetic and structural phase transitions are similarly suppressed by the different dopings and the temperature dependencies of the order parameters are comparable, whereas only the Rh-doped sample shows a reduction of the antiferromagnetically ordered Fe moment in the superconducting state as reported for the Co-doped series. -- The work at the Ames Laboratory was supported by the US DOE, office of science, under contract No. DE-AC02-07CH11358.

  12. Order parameter anisotropy of MgB2 using specific heat jump of ...

    Indian Academy of Sciences (India)

    sample of MgB2 was conducted using two-band isotropic Ginzburg–Landau model [8–10]. Recent studies of the growth of single crystals [6,7] show anisotropy of physical properties in MgB2. One of the important characteristic of superconductors is the electronic specific heat. Their temperature behavior is well-described in ...

  13. The use of simultaneous confidence bands for comparison of single parameter fluorescent intensity data.

    Science.gov (United States)

    Kim, Dongha; Donnenberg, Vera S; Wilson, John W; Donnenberg, Albert D

    2016-01-01

    Despite the utility of multiparameter flow cytometry for a wide variety of biological applications, comparing single parameter histograms of fluorescence intensity remains a mainstay of flow cytometric analysis. Even comparisons requiring multiparameter gating strategies often end with single parameter histograms as the final readout. When histograms overlap, analysis relies on comparison of mean or median fluorescence intensities, or determination of percent positive based on an arbitrary cutoff. Earlier attempts to address this problem utilized either simple channel-by-channel subtraction without statistical evaluation, or the Kolmogorov-Smirnov (KS) or Chi-square test statistics, both of which proved to be overly sensitive to small and biologically insignificant differences. Here we present a method for the comparison of two single-parameter histograms based on difference curves and their simultaneous confidence bands generated by bootstrapping raw channel data. Bootstrapping is a nonparametric statistical approach that can be used to generate confidence intervals without distributional assumptions about the data. We have constructed simultaneous confidence bands and show them to be superior to KS and Cox methods. The method constructs 95% confidence bands about the difference curves, provides a P value for the comparison and calculates the area under the difference curve (AUC) as an estimate of percent positive and the area under the confidence band (AUCSCB95), providing a lower estimate of the percent positive. To demonstrate the utility of this new approach we have examined single-color fluorescence intensity data taken from a cell surface proteomic survey of a lung cancer cell line (A549) and a published fluorescence intensity data from a rhodamine efflux assay of P-glycoprotein activity, comparing rhodamine 123 loading and efflux in CD4 and CD8 T-cell populations. SAS source code is provided as supplementary material. © 2015 International Society for

  14. Taguchi analysis of parameters for small-diameter single wall carbon nanotube growth

    Directory of Open Access Journals (Sweden)

    DaeJin Kang

    2017-09-01

    Full Text Available Small diameter single wall carbon nanotubes are desirable for various physical and electrical properties of carbon nanotubes. Here, we report the sensitivities of parameters and the optimal conditions for small diameter carbon nanotube growth by chemical vapor deposition (CVD. These results were obtained using the Taguchi method, which is commonly used to find the optimal parameters of various processes. The possible parameter ranges given by the experimental equipment and laboratory conditions, we attempted several times to determine the proper ranges, using photoluminescence (PL imaging to determine the exact positions of suspended carbon nanotubes on the quartz substrates after synthesis. The diameters of the carbon nanotubes were then determined from the radial breathing modes (RBM using Raman spectroscopy with a 785nm wavelength laser. Among the 4 major parameters listed above, we concluded that the temperature was the most significant parameter in determining carbon nanotube diameter, hydrogen flow rate was the second most significant, the ethanol and argon gas flow rate was the third, and finally time was the least significant factor.

  15. Detecting high-order interactions of single nucleotide polymorphisms using genetic programming.

    Science.gov (United States)

    Nunkesser, Robin; Bernholt, Thorsten; Schwender, Holger; Ickstadt, Katja; Wegener, Ingo

    2007-12-15

    Not individual single nucleotide polymorphisms (SNPs), but high-order interactions of SNPs are assumed to be responsible for complex diseases such as cancer. Therefore, one of the major goals of genetic association studies concerned with such genotype data is the identification of these high-order interactions. This search is additionally impeded by the fact that these interactions often are only explanatory for a relatively small subgroup of patients. Most of the feature selection methods proposed in the literature, unfortunately, fail at this task, since they can either only identify individual variables or interactions of a low order, or try to find rules that are explanatory for a high percentage of the observations. In this article, we present a procedure based on genetic programming and multi-valued logic that enables the identification of high-order interactions of categorical variables such as SNPs. This method called GPAS cannot only be used for feature selection, but can also be employed for discrimination. In an application to the genotype data from the GENICA study, an association study concerned with sporadic breast cancer, GPAS is able to identify high-order interactions of SNPs leading to a considerably increased breast cancer risk for different subsets of patients that are not found by other feature selection methods. As an application to a subset of the HapMap data shows, GPAS is not restricted to association studies comprising several 10 SNPs, but can also be employed to analyze whole-genome data. Software can be downloaded from http://ls2-www.cs.uni-dortmund.de/~nunkesser/#Software

  16. First- and second-order Raman scattering from MoTe2 single crystal

    Science.gov (United States)

    Caramazza, Simone; Collina, Arianna; Stellino, Elena; Ripanti, Francesca; Dore, Paolo; Postorino, Paolo

    2018-02-01

    We report on Raman experiments performed on a MoTe2 single crystal. The system belongs to the wide family of transition metal dichalcogenides which includes several of the most interesting two-dimensional materials for both basic and applied physics. Measurements were performed in the standard basal plane configuration, by placing the ab plane of the crystal perpendicular to the wave vector k i of the incident beam to explore the in-plane vibrational modes, and in the edge plane configuration with k i perpendicular to the crystal c axis, thus mainly exciting out-of-plane modes. For both configurations we performed a polarization-dependent study of the first-order Raman components and detailed computation of the corresponding selection rules. We were thus able to provide a complete assignment of the observed first-order Raman peaks, in agreement with previous literature results. A thorough analysis of the second-order Raman bands, as observed in both basal and edge plane configurations, provides new information and allows a precise assignment of these spectral structures. In particular, we have observed and assigned Raman active modes of the M point of the Brillouin zone previously predicted by ab initio calculations but never previously measured.

  17. Real-space imaging of non-collinear antiferromagnetic order with a single-spin magnetometer

    Science.gov (United States)

    Gross, I.; Akhtar, W.; Garcia, V.; Martínez, L. J.; Chouaieb, S.; Garcia, K.; Carrétéro, C.; Barthélémy, A.; Appel, P.; Maletinsky, P.; Kim, J.-V.; Chauleau, J. Y.; Jaouen, N.; Viret, M.; Bibes, M.; Fusil, S.; Jacques, V.

    2017-09-01

    Although ferromagnets have many applications, their large magnetization and the resulting energy cost for switching magnetic moments bring into question their suitability for reliable low-power spintronic devices. Non-collinear antiferromagnetic systems do not suffer from this problem, and often have extra functionalities: non-collinear spin order may break space-inversion symmetry and thus allow electric-field control of magnetism, or may produce emergent spin-orbit effects that enable efficient spin-charge interconversion. To harness these traits for next-generation spintronics, the nanoscale control and imaging capabilities that are now routine for ferromagnets must be developed for antiferromagnetic systems. Here, using a non-invasive, scanning single-spin magnetometer based on a nitrogen-vacancy defect in diamond, we demonstrate real-space visualization of non-collinear antiferromagnetic order in a magnetic thin film at room temperature. We image the spin cycloid of a multiferroic bismuth ferrite (BiFeO3) thin film and extract a period of about 70 nanometres, consistent with values determined by macroscopic diffraction. In addition, we take advantage of the magnetoelectric coupling present in BiFeO3 to manipulate the cycloid propagation direction by an electric field. Besides highlighting the potential of nitrogen-vacancy magnetometry for imaging complex antiferromagnetic orders at the nanoscale, these results demonstrate how BiFeO3 can be used in the design of reconfigurable nanoscale spin textures.

  18. 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.

  19. Design of a multi beam klystron cavity from its single beam parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kant, Deepender, E-mail: dkc@ceeri.ernet.in; Joshi, L. M. [CSIR-Central Electronics Engineering Research Institute, Pilani (India); Janyani, Vijay [Department of ECE, MNIT, Jaipur (India)

    2016-03-09

    The klystron is a well-known microwave amplifier which uses kinetic energy of an electron beam for amplification of the RF signal. There are some limitations of conventional single beam klystron such as high operating voltage, low efficiency and bulky size at higher power levels, which are very effectively handled in Multi Beam Klystron (MBK) that uses multiple low purveyance electron beams for RF interaction. Each beam propagates along its individual transit path through a resonant cavity structure. Multi-Beam klystron cavity design is a critical task due to asymmetric cavity structure and can be simulated by 3D code only. The present paper shall discuss the design of multi beam RF cavities for klystrons operating at 2856 MHz (S-band) and 5 GHz (C-band) respectively. The design approach uses some scaling laws for finding the electron beam parameters of the multi beam device from their single beam counter parts. The scaled beam parameters are then used for finding the design parameters of the multi beam cavities. Design of the desired multi beam cavity can be optimized through iterative simulations in CST Microwave Studio.

  20. 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.

  1. 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.

  2. Temperature-dependent ordering phenomena in single crystals of germanium antimony tellurides

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Philipp [Faculty of Chemistry and Mineralogy, Leipzig University, Scharnhorststr. 20, 04275 Leipzig (Germany); Schneider, Matthias N. [Department of Chemistry, LMU Munich, Butenandtstr. 5-13 (D), 81377 Munich (Germany); Oeckler, Oliver, E-mail: oliver.oeckler@gmx.de [Faculty of Chemistry and Mineralogy, Leipzig University, Scharnhorststr. 20, 04275 Leipzig (Germany)

    2015-07-15

    The temperature-dependent behavior of quenched single-crystalline (GeTe){sub n}Sb{sub 2}Te{sub 3} (n~2.8, n~5 and n~11) was investigated by semiquantitative modeling of diffuse X-ray scattering. The structure at room temperature exhibits trigonal twin domains, each comprising a stacking-disordered sequence of distorted rocksalt-type slabs with variable thicknesses. Ge and Sb share the cation position and vacancies are partially ordered in defect layers (van der Waals gaps) between the slabs. The average structure determined with resonant diffraction data corresponds to a rocksalt-type structure whose cation position is split along the stacking direction. Upon heating, cation ordering leads to a metastable superstructure of the rocksalt type at ~400 °C, which transforms to a rocksalt-type high-temperature phase with randomly distributed cations and vacancies at ~500 °C; this structure was also refined using resonant diffraction. Cooling at high or intermediate rates does not yield the long-range ordered phase, but directly leads to the twinned disordered phase. - Graphical abstract: Development of the diffraction patterns of (GeTe){sub ~11}Sb{sub 2}Te{sub 3} upon heating; the insets symbolically sketch the real structure at the corresponding temperatures. - Highlights: • The structure of disordered (GeTe){sub n}Sb{sub 2}Te{sub 3} is described as a function of temperature. • Structural changes are tracked by modeling diffuse X-ray scattering. • Quenched crystals exhibit distorted NaCl-type slabs with different thicknesses. • Vacancy ordering upon heating leads to a metastable superstructure of the NaCl type. • Further heating leads to an undistorted disordered NaCl-type high-temperature phase.

  3. 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.)

  4. Influence of composition on microstructural parameters of single crystal nickel-base superalloys

    Energy Technology Data Exchange (ETDEWEB)

    MacKay, R.A., E-mail: Rebecca.A.MacKay@nasa.gov [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); Gabb, T.P. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); Garg, A. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States); University of Toledo, 2801 W. Bancroft, Toledo, Ohio 43606 (United States); Rogers, R.B.; Nathal, M.V. [NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, Ohio 44135 (United States)

    2012-08-15

    Fourteen nickel-base superalloy single crystals containing a range of chromium (Cr), cobalt (Co), molybdenum (Mo), and rhenium (Re) levels, and fixed amounts of aluminum (Al) and tantalum (Ta), were examined to determine the effect of bulk composition on basic microstructural parameters, including {gamma} Prime solvus, {gamma} Prime volume fraction, topologically close-packed (TCP) phases, {gamma} and {gamma} Prime phase chemistries, and {gamma}-{gamma} Prime lattice mismatch. Regression models describing the influence of bulk alloy composition on each of the microstructural parameters were developed and compared to predictions by a commercially-available software tool that used computational thermodynamics. Co produced the largest change in {gamma} Prime solvus over the wide compositional range explored and Mo produced the biggest effect on the {gamma} lattice parameter over its range, although Re had a very potent influence on all microstructural parameters investigated. Changing the Cr, Co, Mo, and Re contents in the bulk alloy had an impact on their concentrations in the {gamma} matrix and to a smaller extent in the {gamma} Prime phase. The software tool under-predicted {gamma} Prime solvus temperatures and {gamma} Prime volume fractions, and over-predicted TCP phase volume fractions at 982 Degree-Sign C. However, the statistical regression models provided excellent estimations of the microstructural parameters and demonstrated the usefulness of such formulas. - Highlights: Black-Right-Pointing-Pointer Effects of Cr, Co, Mo, and Re on microstructure in new low density superalloys Black-Right-Pointing-Pointer Co produced a large change in {gamma} Prime solvus; Mo had a large effect on lattice mismatch. Black-Right-Pointing-Pointer Re exhibited very potent influence on all microstructural parameters was investigated. Black-Right-Pointing-Pointer {gamma} and {gamma} Prime phase chemistries both varied with temperature and alloy composition. Black

  5. Influence of composition on microstructural parameters of single crystal nickel-base superalloys

    International Nuclear Information System (INIS)

    MacKay, R.A.; Gabb, T.P.; Garg, A.; Rogers, R.B.; Nathal, M.V.

    2012-01-01

    Fourteen nickel-base superalloy single crystals containing a range of chromium (Cr), cobalt (Co), molybdenum (Mo), and rhenium (Re) levels, and fixed amounts of aluminum (Al) and tantalum (Ta), were examined to determine the effect of bulk composition on basic microstructural parameters, including γ′ solvus, γ′ volume fraction, topologically close-packed (TCP) phases, γ and γ′ phase chemistries, and γ–γ′ lattice mismatch. Regression models describing the influence of bulk alloy composition on each of the microstructural parameters were developed and compared to predictions by a commercially-available software tool that used computational thermodynamics. Co produced the largest change in γ′ solvus over the wide compositional range explored and Mo produced the biggest effect on the γ lattice parameter over its range, although Re had a very potent influence on all microstructural parameters investigated. Changing the Cr, Co, Mo, and Re contents in the bulk alloy had an impact on their concentrations in the γ matrix and to a smaller extent in the γ′ phase. The software tool under-predicted γ′ solvus temperatures and γ′ volume fractions, and over-predicted TCP phase volume fractions at 982 °C. However, the statistical regression models provided excellent estimations of the microstructural parameters and demonstrated the usefulness of such formulas. - Highlights: ► Effects of Cr, Co, Mo, and Re on microstructure in new low density superalloys ► Co produced a large change in γ′ solvus; Mo had a large effect on lattice mismatch. ► Re exhibited very potent influence on all microstructural parameters was investigated. ► γ and γ′ phase chemistries both varied with temperature and alloy composition. ► Computational thermodynamic modeling tool did not accurately predict microstructure.

  6. Effect of cobalt on microstructural parameters and mechanical properties of Ni-base single crystal superalloys

    International Nuclear Information System (INIS)

    Suzuki, Takanobu; Imai, Hachiro; Yokokawa, Tadaharu; Kobayashi, Toshiharu; Koizumi, Yutaka; Harada, Hiroshi

    2007-01-01

    The alloying effect of Cobalt (Co) to microstructural parameters and mechanical properties, such as partitioning ratios of alloying elements and creep strength, of Re-bearing Ni-base single crystal superalloys have been investigated. The second generation single crystal superalloys, TMS-82+, Ni-7.8Co-4.9Cr-1.9Mo-8.7W-5.3Al-6.0Ta-2.4Re-0.1Hf, in mass% (8Co) was compared to a Co-free (0Co) and 15 mass% Co (15Co) alloy which had the same chemical composition as TMS-82+ except that Co was changed. It was shown that the partitioning ratios of alloying elements trend to k(=X γ /X' γ )=1, as the content of Co was increased. Furthermore, it was found that there was suitable content of Co for the creep strength under various temperature-stress conditions. (author)

  7. A mathematical model for order splitting in a multiple supplier single-item inventory system

    DEFF Research Database (Denmark)

    Abginehchi, Soheil; Farahani, Reza Zanjirani; Rezapour, Shabnam

    2013-01-01

    The policy of simultaneously splitting replenishment orders among several suppliers has received considerable attention in the last few years and continues to attract the attention of researchers. In this paper, we develop a mathematical model which considers multiple-supplier single-item inventory...... systems. The item acquisition lead times of suppliers are random variables. Backorder is allowed and shortage cost is charged based on not only per unit in shortage but also per time unit. Continuous review (s,Q) policy has been assumed. When the inventory level depletes to a reorder level, the total......, procurement cost, inventory holding cost, and shortage cost, is minimized. We also conduct extensive numerical experiments to show the advantages of our model compared with the models in the literature. According to our extensive experiments, the model developed in this paper is the best model...

  8. Base-Stock Level yang Meminimasi Biaya pada Permasalahan Single Order

    Directory of Open Access Journals (Sweden)

    Tanti Octavia

    2011-01-01

    Full Text Available The purpose of this research is to conduct an analysis on demand characteristic and inventory cost which might potentially influence the determination of base-stock level. Appropriate base-stock level will determine the maximum profit and also reduce the stockout cost for fashion products which has high demand uncertainty and single order problem. Case study is applied on a garment company with eight fashion product types that can be classified into short and long lifetime. The effect of coefficient variation, salvage price and stockout cost is analyzed towards profits and base stock level. It can be concluded that demand variability does not affect base stock level, while stockout cost and salvage price does.

  9. Effect of Surface Modification on the Hansen Solubility Parameters of Single-Walled Carbon Nanotubes

    DEFF Research Database (Denmark)

    Ma, Jing; Larsen, Mikael

    2013-01-01

    In this work, seven types of surface-modified single-walled carbon nanotubes (SWNTs) were studied by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy to investigate the functional groups and extent of functionalization. Hansen solubility parameters were determined based on observations...... of the sedimentation and swollen states of the SWNTs in solvents after ultrasonication, and the results were compared with the hydrodynamic sizes of the SWNTs evaluated by the dynamic light scattering method. We found that the solubility of SWNTs is related to their functional groups and degree of functionalization...

  10. 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

  11. 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.

  12. 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.

  13. 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....

  14. Autostereoscopic three-dimensional display by combining a single spatial light modulator and a zero-order nulled grating

    Science.gov (United States)

    Su, Yanfeng; Cai, Zhijian; Liu, Quan; Lu, Yifan; Guo, Peiliang; Shi, Lingyan; Wu, Jianhong

    2018-04-01

    In this paper, an autostereoscopic three-dimensional (3D) display system based on synthetic hologram reconstruction is proposed and implemented. The system uses a single phase-only spatial light modulator to load the synthetic hologram of the left and right stereo images, and the parallax angle between two reconstructed stereo images is enlarged by a grating to meet the split angle requirement of normal stereoscopic vision. To realize the crosstalk-free autostereoscopic 3D display with high light utilization efficiency, the groove parameters of the grating are specifically designed by the rigorous coupled-wave theory for suppressing the zero-order diffraction, and then the zero-order nulled grating is fabricated by the holographic lithography and the ion beam etching. Furthermore, the diffraction efficiency of the fabricated grating is measured under the illumination of a laser beam with a wavelength of 532 nm. Finally, the experimental verification system for the proposed autostereoscopic 3D display is presented. The experimental results prove that the proposed system is able to generate stereoscopic 3D images with good performances.

  15. Ordering and thermal excitations in dipolar coupled single domain magnet arrays (Presentation Recording)

    Science.gov (United States)

    Östman, Erik; Arnalds, Unnar; Kapaklis, Vassilios; Hjörvarsson, Björgvin

    2015-09-01

    For a small island of a magnetic material the magnetic state of the island is mainly determined by the exchange interaction and the shape anisotropy. Two or more islands placed in close proximity will interact through dipolar interactions. The state of a large system will thus be dictated by interactions at both these length scales. Enabling internal thermal fluctuations, e.g. by the choice of material, of the individual islands allows for the study of thermal ordering in extended nano-patterned magnetic arrays [1,2]. As a result nano-magnetic arrays represent an ideal playground for the study of physical model systems. Here we present three different studies all having used magneto-optical imaging techniques to observe, in real space, the order of the systems. The first study is done on a square lattice of circular islands. The remanent magnetic state of each island is a magnetic vortex structure and we can study the temperature dependence of the vortex nucleation and annihilation fields [3]. The second are long chains of dipolar coupled elongated islands where the magnetization direction in each island only can point in one of two possible directions. This creates a system which in many ways mimics the Ising model [4] and we can relate the correlation length to the temperature. The third one is a spin ice system where elongated islands are placed in a square lattice. Thermal excitations in such systems resemble magnetic monopoles [2] and we can investigate their properties as a function of temperature and lattice parameters. [1] V. Kapaklis et al., New J. Phys. 14, 035009 (2012) [2] V. Kapaklis et al., Nature Nanotech 9, 514(2014) [3] E. Östman et al.,New J. Phys. 16, 053002 (2014) [4] E. Östman et al.,Thermal ordering in mesoscopic Ising chains, In manuscript.

  16. Selected oxidative stress parameters after single and repeated administration of octabromodiphenyl ether to rats

    Directory of Open Access Journals (Sweden)

    Elżbieta Bruchajzer

    2014-10-01

    Full Text Available Objectives: Octabromodiphenyl ether (OctaBDE was used as a flame retardant applied mostly in the manufacture of plastics utilized in the electrical and electronic industries. Owing to its long half-life and being regarded as an environmental pollutant, OctaBDE, like other polybrominated diphenyl ethers, has been classified as a persistent organic pollutant (POP. This study was carried out to assess the effects of oxidative stress (redox homeostasis induced in rats by OctaBDE. Material and Methods: Female Wistar rats exposed intragastrically to OctaBDE at single (25, 200 or 2000 mg/kg b.w., or repeated (0.4, 2, 8, 40 or 200 mg/kg/day doses during 7–28 days were used in the experiment. Selected oxidative stress parameters were determined in the liver and blood serum. Results: Administration (single or repeated of OctaBDE to rats resulted in the impaired redox homeostasis, as evidenced by the increased levels of reduced (GSH and oxidized (GSSG glutathione in the liver, the reduced total antioxidant status (TAS in serum and the increased concentration of malondialdehyde (MDA in the liver. After multiple doses of OctaBDE, elevated activity of glutathione transferase (GST in the liver was also noted. Conclusions: After repeated administration of OctaBDE at the lowest dose (0.4 mg/kg/day, changes were observed in the parameters (MDA, TAS, GSSG indicative of oxidative stress.

  17. 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.

  18. Spectral characteristics of the coherent dynamics of the order parameter in superconducting nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Kettmann, P.; Hannibal, S. [Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster, Münster,48149 (Germany); Croitoru, M.D., E-mail: mikhail.croitoru@uni-bayreuth.de [3Departamento de Física, Universidade Federal de Pernambuco, Recife, Pernambuco,50670-901 (Brazil); Vagov, A.; Axt, V.M. [Theoretische Physik III, Universität Bayreuth, 95440,Bayreuth (Germany); Kuhn, T. [Institut für Festkörpertheorie, Westfälische Wilhelms-Universität Münster, Münster,48149 (Germany)

    2017-02-15

    Highlights: • Within the density-matrix formalism based on the Bogoliubov-de Gennes equations approach we investigate the dynamics of the nonequilibrium BCS pairing induced by a sudden change of the coupling constant in quasi-1D and quasi-0D samples. • We demonstrate that two different dynamical regimes of the amplitude of the BCS gap can be distinguished: an initially damped oscillation in the case of short quantum wires and purely irregular dynamics in the case of nanorods. • We explain this transition on the basis of linearized equations of motion and linke it to the properties of the single-particle energies in the corresponding regimes. - Abstract: Within the density-matrix formalism based on the Bogoliubov-de Gennes equations approach we investigate the dynamics of the non-equilibrium BCS pairing induced by a sudden change of the coupling constant in quasi-1D and quasi-0D samples. We demonstrate that two different dynamical regimes of the amplitude of the BCS gap can be distinguished: an initially damped oscillation in the case of short quantum wires and purely irregular dynamics in the case of nanorods.

  19. Analysis of temperature influence on the informative parameters of single-coil eddy current sensors

    Science.gov (United States)

    Borovik, S. Yu.; Kuteynikova, M. M.; Sekisov, Yu. N.; Skobelev, O. P.

    2017-07-01

    This paper describes the study of temperature in the flowing part of a turbine on the informative parameters (equivalent inductances of primary windings of matching transformers) of single-coil eddy-current sensors with a sensitive element in the form of a conductor section, which are used as part of automation systems for testing gas-turbine engines. In this case, the objects of temperature influences are both sensors and controlled turbine blades. The existing model of electromagnetic interaction of a sensitive element with the end part of a controlled blade is used to obtain quantitative estimates of temperature changes of equivalent inductances of sensitive elements and primary windings of matching transformers. This model is also used to determine the corresponding changes of the informative parameter of the sensor in the process of experimental studies of temperature influences on it (in the absence of blades in the sensitive region). This paper also presents transformations in the form of relationships of informative parameters with radial and axial displacements at normal (20 °C) and nominal (1000 °C) temperatures, and their difference is used to determine the families of dominant functions of temperature, which characterize possible temperature errors for any radial and axial displacements in the ranges of their variation.

  20. 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.

  1. 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.

  2. 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.

  3. 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...

  4. Pricing and ordering policies for price-dependent demand in a supply chain of a single retailer and a single manufacturer

    Science.gov (United States)

    Kim, Jungkyu; Hong, Yushin; Kim, Taebok

    2011-01-01

    This article discusses joint pricing and ordering policies for price-dependent demand in a supply chain consisting of a single retailer and a single manufacturer. The retailer places orders for products according to an EOQ policy and the manufacturer produces them on a lot-for-lot basis. Four mechanisms with differing levels of coordination are presented. Mathematical models are formulated and solution procedures are developed to determine the optimal retail prices and order quantities. Through extensive numerical experiments, we analyse and compare the behaviours and characteristics of the proposed mechanisms, and find that enhancing the level of coordination has important benefits for the supply chain.

  5. 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.

  6. 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.)

  7. Does approach matter? a comparative radiographic analysis of spinopelvic parameters in single level lumbar fusion.

    Science.gov (United States)

    Ahlquist, Seth; Park, Howard Y; Gatto, Jonathan; Shamie, Ayra N; Park, Don Y

    2018-04-06

    Lumbar fusion is a popular and effective surgical option to provide stability and restore anatomy. Particular attention has recently been focused on sagittal alignment and radiographic spinopelvic parameters that apply to lumbar fusion as well as spinal deformity cases. Current literature has demonstrated the effectiveness of various techniques of lumbar fusion, however comparative data of these techniques is limited. To directly compare the impact of various lumbar fusion techniques (ALIF, LLIF, TLIF, PLF) based on radiographic parameters. A single-center retrospective study examining pre-operative and post-operative radiographs. A consecutive list of lumbar fusion surgeries performed by multiple spine surgeons at a single institution from 2013-2016 were identified. Radiographic measurements utilized included segmental lordosis (SL), lumbar lordosis (LL), pelvic incidence (PI), pelvic incidence-lumbar lordosis mismatch (PI-LL), anterior and posterior disk height (DH-A, DH-P respectively), and foraminal height (FH). Radiographic measurements were performed on pre-operative and post-operative lateral lumbar radiographs on all single-level lumbar fusion cases. Demographic data was collected including age, gender, approach, diagnosis, surgical level, and implant lordosis. Paired sample t-test, one-way ANOVA, McNemar Test, and independent sample t-test were used to establish significant differences in the outcome measures. Multiple linear regression was performed to determine a predictive model for lordosis from implant lordosis, fusion technique, and surgical level. There were 164 patients (78 males, 86 females) with a mean age of 60.1 years and average radiographic follow up time of 9.3 months. These included 34 ALIF, 23 LLIF, 63 TLIF, and 44 PLF surgeries. ALIF and LLIF significantly improved SL (7.9° & 4.4°), LL (5.5° & 7.7°), DH-A (8.8 mm & 5.8 mm), DH-P (3.4 mm & 2.3 mm), and FH (2.8 mm & 2.5 mm), respectively (p ≤ .003). TLIF significantly improved these

  8. First-principles study of magnetic ordering of an Al infinite single-row atomic wire.

    Science.gov (United States)

    Ota, Tadashi; Hirose, Kikuji; Ono, Tomoya

    2009-02-11

    In this paper we present a detailed analysis of the atomic and spin-electronic structure of an Al infinite single-row atomic wire (Al-ISAW). Our work is based on ab initio self-consistent field calculations within the local density approximation, and we predict structural transformations during elongation using the norm-conserving (NC) and projector augmented-wave (PAW) pseudopotentials. The results obtained by the NC pseudopotential are in good agreement with those obtained by the PAW pseudopotential. We confirm that the Al-ISAW shows a metal-insulator transition and fractures when elongated beyond the equilibrium length. Then, a wire with antiferromagnetic ordering is found to be the lowest energetically. We find that the magnitude of spin polarization in the vicinity of nuclei is marginal and does not play an important role in the Peierls instability. The present results show that the NC pseudopotential can give an accurate physical picture of the atomic and spin-electronic structures of the Al-ISAW.

  9. Role of third-order dispersion in chirped Airy pulse propagation in single-mode fibers

    Science.gov (United States)

    Cai, Wangyang; Wang, Lei; Wen, Shuangchun

    2018-04-01

    The dynamic propagation of the initial chirped Airy pulse in single-mode fibers is studied numerically, special attention being paid to the role of the third-order dispersion (TOD). It is shown that for the positive TOD, the Airy pulse experiences inversion irrespective of the sign of initial chirp. The role of TOD in the dynamic propagation of the initial chirped Airy pulse depends on the combined sign of the group-velocity dispersion (GVD) and the initial chirp. If the GVD and chirp have the opposite signs, the chirped Airy pulse compresses first and passes through a breakdown area, then reconstructs a new Airy pattern with opposite acceleration, with the breakdown area becoming small and the main peak of the new Airy pattern becoming asymmetric with an oscillatory structure due to the positive TOD. If the GVD and chirp have the same signs, the finite-energy Airy pulse compresses to a focal point and then inverses its acceleration, in the case of positive TOD, the distance to the focal point becoming smaller. At zero-dispersion point, the finite-energy Airy pulse inverses to the opposite acceleration at a focal point, with the tight-focusing effect being reduced by initial chirp. Under the effect of negative TOD, the initial chirped Airy pulse disperses and the lobes split. In addition, in the anomalous dispersion region, for strong nonlinearity, the initial chirped Airy pulse splits and enters a soliton shedding regime.

  10. Optimal path planning for single and multiple aircraft using a reduced order formulation

    Science.gov (United States)

    Twigg, Shannon S.

    High-flying unmanned reconnaissance and surveillance systems are now being used extensively in the United States military. Current development programs are producing demonstrations of next-generation unmanned flight systems that are designed to perform combat missions. Their use in first-strike combat operations will dictate operations in densely cluttered environments that include unknown obstacles and threats, and will require the use of terrain for masking. The demand for autonomy of operations in such environments dictates the need for advanced trajectory optimization capabilities. In addition, the ability to coordinate the movements of more than one aircraft in the same area is an emerging challenge. This thesis examines using an analytical reduced order formulation for trajectory generation for minimum time and terrain masking cases. First, pseudo-3D constant velocity equations of motion are used for path planning for a single vehicle. In addition, the inclusion of winds, moving targets and moving threats is considered. Then, this formulation is increased to using 3D equations of motion, both with a constant velocity and with a simplified varying velocity model. Next, the constant velocity equations of motion are expanded to include the simultaneous path planning of an unspecified number of vehicles, for both aircraft avoidance situations and formation flight cases.

  11. A Single-Case Study of Resiliency After Extreme Incest in an Old Order Amish Family.

    Science.gov (United States)

    McGuigan, William M; Stephenson, Sarah J

    2015-01-01

    This exploratory research brief presents a single case study of the resiliency of "Mary B." She grew up in an Old Order Amish family where isolation, secrecy, and patriarchy masked repeated sexual assaults by her older brothers that began at age 7. By the age of 20, Mary alleged she had been raped on more than 200 separate occasions by members of her Amish family. After years of pleading with her mother and church officials to intervene, she sought therapy outside the Amish community. This led to three of her brothers being incarcerated. Her family disowned her and she was banned from the Amish community, leaving with an 8th grade education and little more than the clothes she was wearing. In less than 2 years, Mary had moved to a new town, completed her GED, obtained a car and driving license, maintained a small home, and worked as a certified nursing assistant. She consented to tape recorded interviews and completed several quantitative diagnostic measures. Scores on the diagnostic measures placed her within the normal range on self-esteem, competency, depression, stress, social support, and life skills. Analysis of interviews revealed Mary rebounded from her past by reframing her experiences. Themes identified within the interviews supported 6 of the 7 types of resiliencies (insight, independence, initiative, relationships, humor, and morality) outlined in the therapeutic Challenge Model.

  12. Pseudotemporal Ordering of Single Cells Reveals Metabolic Control of Postnatal β Cell Proliferation.

    Science.gov (United States)

    Zeng, Chun; Mulas, Francesca; Sui, Yinghui; Guan, Tiffany; Miller, Nathanael; Tan, Yuliang; Liu, Fenfen; Jin, Wen; Carrano, Andrea C; Huising, Mark O; Shirihai, Orian S; Yeo, Gene W; Sander, Maike

    2017-05-02

    Pancreatic β cell mass for appropriate blood glucose control is established during early postnatal life. β cell proliferative capacity declines postnatally, but the extrinsic cues and intracellular signals that cause this decline remain unknown. To obtain a high-resolution map of β cell transcriptome dynamics after birth, we generated single-cell RNA-seq data of β cells from multiple postnatal time points and ordered cells based on transcriptional similarity using a new analytical tool. This analysis captured signatures of immature, proliferative β cells and established high expression of amino acid metabolic, mitochondrial, and Srf/Jun/Fos transcription factor genes as their hallmark feature. Experimental validation revealed high metabolic activity in immature β cells and a role for reactive oxygen species and Srf/Jun/Fos transcription factors in driving postnatal β cell proliferation and mass expansion. Our work provides the first high-resolution molecular characterization of state changes in postnatal β cells and paves the way for the identification of novel therapeutic targets to stimulate β cell regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. 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.

  14. STUDY OF SINGLE WALLED CARBON NANOTUBE REINFORCED POLYMER COMPOSITES BY HANSEN SOLUBILITY PARAMETERS

    DEFF Research Database (Denmark)

    Ma, Jing

    reinforcement of the polymer by the addition of SWNTs. Existence of agglomerates, voids, and the lower glass transition temperature of epoxy resin, may give the negative effect on the mechanical properties of nanocomposite materials. In the design aspect of the composite material, HSP could help match SWNTs......Single Walled carbon nanotubes (SWNTs) possess superior mechanical, thermal and electrical properties. The use of SWNTs as a reinforcement in polymer matrix is a hot research topic. However, the poor dispersion of SWNTs in polymers and the weak interface between the nanotubes and polymers are two...... major challenges which limit the use of SWNTs for reinforced polymer composites. The main objectives of this PhD work are to design, fabricate SWNTs/polymer composites and characterize the mechanical properties of the composite materials. This study uses the Hansen solubility parameters (HSP) to predict...

  15. Practical signal-dependent noise parameter estimation from a single noisy image.

    Science.gov (United States)

    Liu, Xinhao; Tanaka, Masayuki; Okutomi, Masatoshi

    2014-10-01

    The additive white Gaussian noise is widely assumed in many image processing algorithms. However, in the real world, the noise from actual cameras is better modeled as signal-dependent noise (SDN). In this paper, we focus on the SDN model and propose an algorithm to automatically estimate its parameters from a single noisy image. The proposed algorithm identifies the noise level function of signal-dependent noise assuming the generalized signal-dependent noise model and is also applicable to the Poisson-Gaussian noise model. The accuracy is achieved by improved estimation of local mean and local noise variance from the selected low-rank patches. We evaluate the proposed algorithm with both synthetic and real noisy images. Experiments demonstrate that the proposed estimation algorithm outperforms the state-of-the-art methods.

  16. Parameter estimation in neuronal stochastic differential equation models from intracellular recordings of membrane potentials in single neurons

    DEFF Research Database (Denmark)

    Ditlevsen, Susanne; Samson, Adeline

    2016-01-01

    Dynamics of the membrane potential in a single neuron can be studied by estimating biophysical parameters from intracellular recordings. Diffusion processes, given as continuous solutions to stochastic differential equations, are widely applied as models for the neuronal membrane potential evolut...

  17. 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

  18. First steps towards fuel cells testing harmonisation: Procedures and parameters for single cell performance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Lunghi, P. [Department of Industrial Engineering, University of Perugia, Via Duranti 93, Perugia (Italy); Ubertini, S. [Department of Mechanical Engineering, University of Rome ' ' Tor Vergata' ' , Via di Torvergata, 110, Rome (Italy)

    2004-01-01

    The great interest in Fuel Cell Systems, combined with the innovation of the device itself, has led to a huge developmental effort to make the steps necessary for future FC plant commissioning. The clearest and most effective way to evaluate the performance of a fuel cell is to measure it directly and, since few fuel cell test rigs are available at the moment, standard experimental procedures have not been realized so far. Our research group is currently performing single cell testing at the University of Perugia fuel cell laboratory and particular emphasis has been put on the definition of procedures and the testing of parameterisation. The work team strongly believes that this is the key to effective system testing and reliable performance evaluation. In this work, the test parameterisation developed by the team, and the resulting advanced control procedure used for a single MCFC experimental characterization are presented. Efforts have been dedicated to obtain some relevant non-dimensional parameters to allow an easy understanding of the results and quick comparisons with other tests under different operating conditions, or with results obtained on different cells eventually tested in different laboratories. The authors strongly emphasise this topic to avoid the data that developers and research institutions collect being of no practical use due to a lack of shared rules. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  19. Optimizing sonication parameters for dispersion of single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Haibo [Fraunhofer Institute for Electronic Nano Systems (Fraunhofer ENAS), 09126 Chemnitz (Germany); Graduate University of the Chinese Academy of Sciences, Beijing (China); State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, 110016 Shenyang (China); Hermann, Sascha, E-mail: sascha.hermann@zfm.tu-chemnitz.de [Center for Microtechnologies (ZfM), Chemnitz University of Technology, 09126 Chemnitz (Germany); Schulz, Stefan E.; Gessner, Thomas [Fraunhofer Institute for Electronic Nano Systems (Fraunhofer ENAS), 09126 Chemnitz (Germany); Center for Microtechnologies (ZfM), Chemnitz University of Technology, 09126 Chemnitz (Germany); Dong, Zaili [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, 110016 Shenyang (China); Li, Wen J., E-mail: wenjungli@gmail.com [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, 110016 Shenyang (China); Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong SAR (China)

    2012-10-26

    Graphical abstract: We study the dispersing behavior of SWCNTs based on the surfactant and the optimization of sonication parameters including the sonication power and running time. Highlights: Black-Right-Pointing-Pointer We study the optimization of sonication for the surfactant-based dispersion of SWCNTs. Black-Right-Pointing-Pointer The absorption spectrum of SWCNT solution strongly depend on the sonication conditions. Black-Right-Pointing-Pointer The sonication process has an important influence on the average length and diameters of SWCNTs in solution. Black-Right-Pointing-Pointer Centrifugation mainly contributes to the decrease of nonresonant absorption background. Black-Right-Pointing-Pointer Under the same sonication parameters, the large-diameter tip performs dispersion of SWCNTs better than the small-diameter tip. -- Abstract: Non-covalent functionalization based on surfactants has become one of the most common methods for dispersing of single-walled carbon nanotubes (SWCNTs). Previously, efforts have mainly been focused on experimenting with different surfactant systems, varying their concentrations and solvents. However sonication plays a very important role during the surfactant-based dispersion process for SWCNTs. The sonication treatment enables the surfactant molecules to adsorb onto the surface of SWCNTs by overcoming the interactions induced by the hydrophobic, electrostatic and van der Waals forces. This work describes a systematic study of the influence of the sonication power and time on the dispersion of SWCNTs. UV-vis-NIR absorption spectra is used to analyze and to evaluate the dispersion of SWCNTs in an aqueous solution of 1 w/v% sodium deoxycholate (DOC) showing that the resonant and nonresonant background absorption strongly depends on the sonication conditions. Furthermore, the diameter and length of SWCNTs under different sonication parameters are investigated using atomic force microscopy (AFM).

  20. Anti-control of chaos of single time scale brushless dc motors and chaos synchronization of different order systems

    International Nuclear Information System (INIS)

    Ge Zhengming; Chang Chingming; Chen Yensheng

    2006-01-01

    Anti-control of chaos of single time scale brushless dc motors (BLDCM) and chaos synchronization of different order systems are studied in this paper. By addition of an external nonlinear term, we can obtain anti-control of chaos. Then, by addition of the coupling terms, by the use of Lyapunov stability theorem and by the linearization of the error dynamics, chaos synchronization between a third-order BLDCM and a second-order Duffing system are presented

  1. Estimation of a respiratory signal from a single-lead ECG using the 4th order central moments

    Directory of Open Access Journals (Sweden)

    Schmidt Marcus

    2015-09-01

    Full Text Available For a variety of clinical applications like magnetic resonance imaging (MRI the monitoring of vital signs is a common standard in clinical daily routine. Besides the electrocardiogram (ECG, the respiratory activity is an important vital parameter and might reveal pathological changes. Thoracic movement and the resulting impedance change between ECG electrodes enable the estimation of the respiratory signal from the ECG. This ECG-derived respiration (EDR can be used to calculate the breathing rate without the need for additional devices or monitoring modules. In this paper a new method is presented to estimate the respiratory signal from a single-lead ECG. The 4th order central moments was used to estimate the EDR signal exploiting the change of the R-wave slopes induced by respiration. This method was compared with two approaches by analyzing the Fantasia database from www.physionet.org. Furthermore, the ECG signals of 24 healthy subjects placed in an 3 T MR-scanner were acquired.

  2. 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.

  3. 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.

  4. Calibration and Validation Parameter of Hydrologic Model HEC-HMS using Particle Swarm Optimization Algorithms – Single Objective

    Directory of Open Access Journals (Sweden)

    R. Garmeh

    2016-02-01

    model that simulates both wet and dry weatherbehavior.Programming of HEC –HMS has been done by MATLAB and techniques such as elite mutation and creating confusion have been used in order to strengthen the algorithm and improve the results. The event-based HEC-HMS model simulatesthe precipitation-runoff process for each set of parameter values generated by PSO. Turbulentand elitism with mutation are also employed to deal with PSO premature convergence. The integrated PSO-HMS model is tested on the Kardeh dam basin located in the Khorasan Razavi province. Results and Discussion: Input parameters of hydrologic models are seldomknown with certainty. Therefore, they are not capable ofdescribing the exact hydrologic processes. Input data andstructural uncertainties related to scale and approximationsin system processes are different sources of uncertainty thatmake it difficult to model exact hydrologic phenomena.In automatic calibration, the parameter values dependon the objective function of the search or optimization algorithm.In characterizing a runoff hydrograph, threecharacteristics of time-to-peak, peak of discharge and totalrunoff volume are of the most importance. It is thereforeimportant that we simulate and observe hydrographs matchas much as possible in terms of those characteristics. Calibration was carried out in single objective cases. Model calibration in single-objective approach with regard to the objective function in the event of NASH and RMSE were conducted separately.The results indicated that the capability of the model was calibrated to an acceptable level of events. Continuing calibration results were evaluated by four different criteria.Finally, to validate the model parameters with those obtained from the calibration, tests perfomed indicated poor results. Although, based on the calibration and verification of individual events one event remains, suggesting set is a possible parameter. Conclusion: All events were evaluated by validations and the

  5. Reinforcement learning versus heuristics for order acceptance on a single resource

    NARCIS (Netherlands)

    Mainegra Hing, M.; van Harten, Aart; Schuur, Peter

    2007-01-01

    Order Acceptance (OA) is one of the main functions in business control. Accepting an order when capacity is available could disable the system to accept more profitable orders in the future with opportunity losses as a consequence. Uncertain information is also an important issue here. We use Markov

  6. A novel non invasive measurement of hemodynamic parameters: Comparison of single-chamber ventricular and dual-chamber pacemaker

    Directory of Open Access Journals (Sweden)

    Ingrid M. Pardede

    2008-03-01

    Full Text Available We carried out a cross sectional study to analyze hemodynamic parameters of single-chamber ventricular pacemaker compared with dual-chamber pacemaker by using thoracic electrical bioimpedance monitoring method (Physio Flow™ - a novel simple non-invasive measurement. A total of 48 consecutive outpatients comprised of 27 single chamber pacemaker and 21 dual chamber were analyzed. We measured cardiac parameters: heart rate, stroke volume index, cardiac output index, estimated ejection fraction, end diastolic volume, early diastolic function ratio, thoracic fluid index, and systemic parameters: left cardiac work index and systemic vascular resistance index. Baseline characteristic and pacemaker indication were similar in both groups. Cardiac parameters assessment revealed no significant difference between single-chamber pacemaker and dual-chamber pacemaker in heart rate, stroke volume index, cardiac index, estimated ejection fraction, end-diastolic volume, thoracic fluid index. There was significantly higher early diastolic function ratio in single-chamber pacemaker compared to dual-chamber pacemaker: 92% (10.2-187.7% vs. 100.6% (48.7-403.2%; p=0.006. Systemic parameters assessment revealed significantly higher left cardiac work index in single-chamber group than dual-chamber group 4.9 kg.m/m² (2.8-7.6 kg.m/m² vs. 4.3 kg.m/m² (2.9-7.2 kg.m/m²; p=0.004. There was no significant difference on systemic vascular resistance in single-chamber compared to dual-chamber pacemaker. Single-chamber ventricular pacemaker provides similar stroke volume, cardiac output and left cardiac work, compared to dual-chamber pacemaker. A non-invasive hemodynamic measurement using thoracic electrical bioimpedance is feasible for permanent pacemaker outpatients. (Med J Indones 2008; 17: 25-32Keywords: Permanent pacemaker, single chamber, dual chamber, thoracic electrical bioimpedance, hemodynamic parameter

  7. 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.

  8. 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

  9. 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.

  10. Piezoelectric transducer parameter selection for exciting a single mode from multiple modes of Lamb waves

    International Nuclear Information System (INIS)

    Zhang Hai-Yan; Yu Jian-Bo

    2011-01-01

    Excitation and propagation of Lamb waves by using rectangular and circular piezoelectric transducers surface-bonded to an isotropic plate are investigated in this work. Analytical stain wave solutions are derived for the two transducer shapes, giving the responses of these transducers in Lamb wave fields. The analytical study is supported by a numerical simulation using the finite element method. Symmetric and antisymmetric components in the wave propagation responses are inspected in detail with respect to test parameters such as the transducer geometry, the length and the excitation frequency. By placing only one piezoelectric transducer on the top or the bottom surface of the plate and weakening the strength of one mode while enhancing the strength of the other modes to find the centre frequency, with which the peak wave amplitude ratio between the S0 and A0 modes is maximum, a single mode excitation from the multiple modes of the Lamb waves can be achieved approximately. Experimental data are presented to show the validity of the analyses. The results are used to optimize the Lamb wave detection system. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  11. 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).

  12. Structural effects on charge order in single-layered manganites R{sub 1-x}A{sub 1+x}MnO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Engelmayer, Johannes; Ulbrich, Holger; Weber, Lisa; Braden, Markus; Lorenz, Thomas [II. Physikalisches Institut, Universitaet zu Koeln (Germany)

    2015-07-01

    Single-layered manganites show a complex interplay between charge, orbital, and magnetic degrees of freedom. For half-doped (x=1/2) R{sub 1-x}A{sub 1+x}MnO{sub 4} (R=Pr,La; A=Ca,Sr) the so-called Goodenough model is well established. This model proposes a site-centered charge order with a checkerboard pattern of Mn{sup 3+} and Mn{sup 4+} ions accompanied by an orbital order. Furthermore a magnetic order develops with ferromagnetic three-spin zig-zag chains and antiferromagnetic interchain coupling. For x=2/3 the charge order appears as stripe pattern with two adjacent stripes of Mn{sup 4+} ions alternating with a single stripe of Mn{sup 3+} ions, while in the magnetically ordered state four-spin zig-zag chains arise. For a deeper understanding of the emergence of charge order, it is appropriate to vary on the one hand the elements R and A while keeping the doping level x constant - involving structural changes at fixed charge carrier density - and on the other hand change the doping level with the same R and A. Therefore various single crystals of R{sub 1-x}A{sub 1+x}MnO{sub 4} with R=(Pr, Nd, Sm, Tb), A=(Ca, Sr) and 0.5 ≤ x ≤ 0.7 were grown and their structural parameters were determined by X-ray diffraction. Based on measurements of resistivity, magnetization, specific heat, and crystal structure we discuss the influence of structural variations on the ordering temperature.

  13. Control of the structural parameters in the (Zn – Zn16Ti single crystal growth

    Directory of Open Access Journals (Sweden)

    W. Wołczyński

    2011-10-01

    Full Text Available The (Zn - single crystal was obtained by means of the Bridgman system. Several growth rates were applied during the experiment. The graphite crucible was used in order to perform the solidification process. The unidirectional solidification occurred with the presence of the moving temperature field. The thermal gradient was positive so that the constrained growth of the single crystal was ensured. The (Zn single crystal was doped with small addition of titanium and copper. The titanium formed an intermetallic compound Zn16-Ti. The copper was solved in the solid solution (Zn. The precipitates of (Zn and Zn16-Ti formed a stripes localized cyclically along the single crystal length. The intermetallic compound Zn16-Ti strengthened the (Zn single crystal. The structural transitions were observed in the stripes with the increasing solidification rate. Within the first range of the solidification rates ( the irregular L-shape rod-like intermetalliccompoundwas revealed. At the- threshold growth rate branches disappear continuously till the growth rate equal to. At the same range of growth rates the regular lamellar eutectic structure (Zn – Zn16-Ti appeared continuously and it existed exclusively till the second threshold growth rate equal to. Above the second threshold growth rate the regular rod-like eutectic structure was formed, only. Thegeneral theory for the stationary eutectic solidification was developed. According to this theory the eutectic structure localized within the stripes is formed under stationary state. Therefore, the criterion of the minimum entropy production defines well the stationary solidification. The entropy production was calculated for the regular rod-like eutectic structure formation and for the regular lamellar eutectic structure formation. It was postulated that the observed structure are subjected to the competition. That is why the structural transitionwere observed at therevealedthreshold growth rates.Moreover, it was

  14. Determining The Optimal Order Picking Batch Size In Single Aisle Warehouses

    NARCIS (Netherlands)

    T. Le-Duc (Tho); M.B.M. de Koster (René)

    2002-01-01

    textabstractThis work aims at investigating the influence of picking batch size to average time in system of orders in a one-aisle warehouse under the assumption that order arrivals follow a Poisson process and items are uniformly distributed over the aisle's length. We model this problem as an

  15. 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

  16. 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.

  17. INTELLIGENT FRACTIONAL ORDER ITERATIVE LEARNING CONTROL USING FEEDBACK LINEARIZATION FOR A SINGLE-LINK ROBOT

    Directory of Open Access Journals (Sweden)

    Iman Ghasemi

    2017-05-01

    Full Text Available In this paper, iterative learning control (ILC is combined with an optimal fractional order derivative (BBO-Da-type ILC and optimal fractional and proportional-derivative (BBO-PDa-type ILC. In the update law of Arimoto's derivative iterative learning control, a first order derivative of tracking error signal is used. In the proposed method, fractional order derivative of the error signal is stated in term of 'sa' where  to update iterative learning control law. Two types of fractional order iterative learning control namely PDa-type ILC and Da-type ILC are gained for different value of a. In order to improve the performance of closed-loop control system, coefficients of both  and  learning law i.e. proportional , derivative  and  are optimized using Biogeography-Based optimization algorithm (BBO. Outcome of the simulation results are compared with those of the conventional fractional order iterative learning control to verify effectiveness of BBO-Da-type ILC and BBO-PDa-type ILC

  18. Composite Beam Cross-Section Analysis by a Single High-Order Element Layer

    DEFF Research Database (Denmark)

    Couturier, Philippe; Krenk, Steen

    2015-01-01

    An analysis procedure of general cross-section properties is presented. The formulation is based on the stress-strain states in the classic six equilibrium modes of a beam by considering a finite thickness slice modelled by a single layer of 3D finite elements. The theory is illustrated by applic...

  19. Zeroth order phase transition in a holographic superconductor with single impurity

    NARCIS (Netherlands)

    Zeng, Hua Bi; Zhang, Hai-Qing

    We investigate the single normal impurity effect in a superconductor by the holographic method. When the size of impurity is much smaller than the host superconductor, we can reproduce the Anderson theorem, which states that a conventional s-wave superconductor is robust to a normal (non-magnetic)

  20. A second-order autocorrelator for single-shot measurement of ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    mental and second-harmonic frequency respectively, and 2α is the crossover angle of the beams inside the ... dispersion (GVD) effects in the crystal and spatial resolution of the imaging system. In the case ... Figure 3a shows the image of SH radiation from the KDP crystal corresponding to the single- shot operation of the ...

  1. 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.

  2. 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.

  3. Finding Order in Randomness: Single-Molecule Studies Reveal Stochastic RNA Processing | Center for Cancer Research

    Science.gov (United States)

    Producing a functional eukaryotic messenger RNA (mRNA) requires the coordinated activity of several large protein complexes to initiate transcription, elongate nascent transcripts, splice together exons, and cleave and polyadenylate the 3’ end. Kinetic competition between these various processes has been proposed to regulate mRNA maturation, but this model could lead to multiple, randomly determined, or stochastic, pathways or outcomes. Regulatory checkpoints have been suggested as a means of ensuring quality control. However, current methods have been unable to tease apart the contributions of these processes at a single gene or on a time scale that could provide mechanistic insight. To begin to investigate the kinetic relationship between transcription and splicing, Daniel Larson, Ph.D., of CCR’s Laboratory of Receptor Biology and Gene Expression, and his colleagues employed a single-molecule RNA imaging approach to monitor production and processing of a human β-globin reporter gene in living cells.

  4. Method of applying single higher order polynomial basis function over multiple domains

    CSIR Research Space (South Africa)

    Lysko, AA

    2010-03-01

    Full Text Available M) with higher-order polynomial basis functions, and applied to a surface form of the electrical field integral equation, under thin wire approximation. The main advantage of the proposed method is in permitting to reduce the required number of unknowns when...

  5. Method of applying single higher order polynomial basis function over multiple domains

    CSIR Research Space (South Africa)

    Lysko, AA

    2010-03-01

    Full Text Available A novel method has been devised where one set of higher order polynomial-based basis functions can be applied over several wire segments, thus permitting to decouple the number of unknowns from the number of segments, and so from the geometrical...

  6. A second-order autocorrelator for single-shot measurement of ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    background intensity contrast ratio of 25 ps laser pulses from an active-passive mode-locked. Nd:YLF laser carried out in this mode are also presented. 2. Principle. The second order autocorrelation technique basically involves splitting a laser beam into two beams of equal intensity and overlapping them in a nonlinear ...

  7. Tuning the dispersion and single/multi-modeness of a hole-assisted fiber by the hole's geometrical parameters

    NARCIS (Netherlands)

    Uranus, H.P.; Hoekstra, Hugo; van Groesen, Embrecht W.C.

    2008-01-01

    Using a vectorial finite element mode solver developed earlier, we studied a hole-assisted multi-ring fiber. We report the role of the hole’s geometrical parameters in tuning the waveguide dispersion and the single/multi-modeness of the particular fiber. By correctly selecting the hole’s size and

  8. Femtosecond Single-Shot Imaging of Nanoscale Ferromagnetic Order in Co/Pd Multilayers using Resonant X-ray Holography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tianhan; Zhu, Diling; Benny Wu,; Graves, Catherine; Schaffert, Stefan; Rander, Torbjorn; Muller, leonard; Vodungbo, Boris; Baumier, Cedric; Bernstein, David P.; Brauer, Bjorn; Cros, Vincent; Jong, Sanne de; Delaunay, Renaud; Fognini, Andreas; Kukreja, Roopali; Lee, Sooheyong; Lopez-Flores, Victor; Mohanty, Jyoti; Pfau, Bastian; Popescu, 5 Horia

    2012-05-15

    We present the first single-shot images of ferromagnetic, nanoscale spin order taken with femtosecond x-ray pulses. X-ray-induced electron and spin dynamics can be outrun with pulses shorter than 80 fs in the investigated fluence regime, and no permanent aftereffects in the samples are observed below a fluence of 25 mJ/cm{sup 2}. Employing resonant spatially-muliplexed x-ray holography results in a low imaging threshold of 5 mJ/cm{sup 2}. Our results open new ways to combine ultrafast laser spectroscopy with sequential snapshot imaging on a single sample, generating a movie of excited state dynamics.

  9. Formation of SmFe5(0001) ordered alloy thin films on Cu(111) single-crystal underlayers

    International Nuclear Information System (INIS)

    Yabuhara, Osamu; Ohtake, Mitsuru; Nukaga, Yuri; Futamoto, Masaaki; Kirino, Fumiyoshi

    2010-01-01

    SmFe 5 (0001) single-crystal thin films are prepared by molecular beam epitaxy employing Cu(111) single-crystal underlayers on MgO(111) substrates. The Cu atoms diffuse into the Sm-Fe layer and substitute the Fe sites in SmFe 5 structure forming an alloy compound of Sm(Fe,Cu) 5 . The Sm(Fe,Cu) 5 film is more Cu enriched with increasing the substrate temperature. The Cu underlayer plays an important role in assisting the formation of the ordered phase.

  10. Neutron scattering investigation of the magnetic order in single crystalline BaFe2As2

    OpenAIRE

    Kofu, M.; Qiu, Y.; Bao, Wei; Lee, S. -H.; Chang, S.; Wu, T.; Wu, G.; Chen, X. H.

    2009-01-01

    The magnetic structure of BaFe2As2 was completely determined from polycrystalline neutron diffraction measurements soon after the ThCr2Si2-type FeAs-based superconductors were discovered. Both the moment direction and the in-plane antiferromagnetic wavevector are along the longer a-axis of the orthorhombic unit cell. There is only one combined magnetostructural transition at about 140 K. However, a later single-crystal neutron diffraction work reported contradicting results. Here we show neut...

  11. Recursion method for the quasiparticle structure of a single vortex with induced magnetic order

    DEFF Research Database (Denmark)

    Udby, L.; Andersen, B.M.; Hedegård, P.

    2006-01-01

    . Furthermore, we study the low-energy quasiparticle structure when magnetic vortices operate as pinning centers for surrounding unidirectional spin density waves (stripes). We calculate the Fourier transformed LDOS and show how the energy dependence of relevant Fourier components can be used to determine...... the nature of the magnetic field-induced order, and predict field-induced LDOS features that can be tested by future scanning tunneling microscopy experiments....

  12. 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.

  13. Parameter dependence of homoclinic solutions in a single long Josephson junction

    NARCIS (Netherlands)

    van den Berg, J.B.; van Gils, Stephanus A.; Visser, T.P.P.

    2003-01-01

    For a model of the long Josephson junction one can calculate for which parameter values there exists a homoclinic solution (fluxon solution). These parameter values appear to lie on a spiral. We show that this is a consequence of the presence of a heteroclinic solution, which lies at the centre of

  14. Algorithm and program for precise determination of unit-cell parameters of single crystal taking into account the sample eccentricity

    Science.gov (United States)

    Dudka, A. P.; Smirnova, E. S.; Verin, I. A.; Bolotina, N. B.

    2017-07-01

    A technique has been developed to refine the unit-cell parameters of single crystals with minimization of the influence of instrumental errors on the result. The corresponding computational procedure HuberUB is added to the software package of Huber-5042 diffractometer with a point detector and closedcycle helium cryostat Displex DE-202. The parameters of unit cell, its orientation, the goniometer zero angles, the sample eccentricity, the distances in the goniometer, and the radiation wavelength were refined by the nonlinear least-squares method, which allows imposition of constraints on the unit-cell parameters, depending on the crystal symmetry. The technique is approved on a LuB12 single crystal. The unit-cell parameters are determined in a temperature range of 20-295 K, with an absolute error not larger than 0.0004 Å (the relative error is of 5 × 10-5). The estimates of the unit-cell parameters obtained by the proposed method are evidenced to be unbiased. Some specific features of the behavior of parameters in the ranges of 120-140 and 20-50 K are revealed, which correlate with the anomalies of the physical properties of the crystal.

  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. Male Fertility and Reduction in Semen Parameters: A Single Tertiary-Care Center Experience

    Directory of Open Access Journals (Sweden)

    D. Milardi

    2012-01-01

    Full Text Available Background. Infertility is both a clinical and a public problem, affecting the life of the couple, the healthcare services, and social environment. Standard semen analysis is the surrogate measure of male fertility in clinical practice. Objective. To provide information about the relationship between semen parameters and spontaneous conception. Methods. We evaluated retrospectively 453 pregnancies that occurred among 2935 infertile couples evaluated at an infertility clinic of a tertiary-care university hospital, between 2004 and 2009. Results. Normal semen analysis was present only in 158 patients; 295 subfertile patients showed alterations in at least one seminal parameter. A reduction in all seminal parameters was observed in 41 patients. Etiological causes of male infertility were identified in 314 patients. Conclusion. Our data highlights the possibility of a spontaneous conception with semen parameters below WHO reference values. Therefore, we support the importance of defining reference values on a population of fertile men. Finally, we analyzed the related ethical issues.

  17. Second order single particle dynamics in quasi-isochronous storage rings and its application to the LNLS-UVX ring

    Energy Technology Data Exchange (ETDEWEB)

    Lin Liu (Pro-Reitoria de Pesquisa, Univ. Estadual de Campinas, SP (Brazil) Lab. Nacional de Luz Sincrotron-LNLS, Campinas, SP (Brazil)); Concalves da Silva, C.E.T. (Inst. de Fisica Gleb Wataghin, Univ. Estadual de Campinas, SP (Brazil) Lab. Nacional de Luz Sincrotron-LNLS, Campinas, SP (Brazil))

    1993-05-15

    We analyze the second order single particle longitudinal dynamics in a quasi-isochronous storage ring. We expand the momentum compaction factor to include the effects of second order terms taking sextupoles into account and of transverse betatron oscillations. The introduction of nonlinearities due to higher order terms results in a second stability region for longitudinal phase oscillations, in addition to the well known linear stable operation point. The conditions for this new solution to fall within the energy acceptance of the storage ring are presented. Inclusion of transverse motion coupling may lead to either a reduction or an enhancement of the stable longitudinal phase-space regions. The analysis is applied to the LNLS 1.15 GeV UVX electron storage ring, indicating that it should be possible to operate this ring in a quasi-isochronous mode. (orig.).

  18. Bulk crystal growth and their effective third order nonlinear optical properties of 2-(4-fluorobenzylidene) malononitrile (FBM) single crystal

    Science.gov (United States)

    Priyadharshini, A.; Kalainathan, S.

    2018-04-01

    2-(4-fluorobenzylidene) malononitrile (FBM), an organic third order nonlinear (TONLO) single crystal with the dimensions of 32 × 7 × 11 mm3, has been successfully grown in acetone solution by slow evaporation technique at 35 °C. The crystal system (triclinic), space group (P-1) and crystalline purity of the titular crystal were measured by single crystal and powder X-ray diffraction, respectively. The molecular weight and the multiple functional groups of the FBM material were confirmed through the mass and FT-IR spectral analysis. UV-Vis-NIR spectral study enroles that the FBM crystal exhibits excellent transparency (83%) in the entire visible and near infra-red region with a wide bandgap 2.90 eV. The low dielectric constant (εr) value of FBM crystal is appreciable for microelectronics industry applications. Thermal stability and melting point (130.09 °C) were ascertained by TGA-DSC analysis. The laser-induced surface damage threshold (LDT) value of FBM specimen is found to be 2.14 GW/cm2, it is fairly good compared to other reported NLO crystals. The third - order nonlinear optical character of the FBM crystal was confirmed through the typical single beam Z-scan technique. All these finding authorized that the organic crystal of FBM is favorably suitable for NLO applications.

  19. Carrier mediated transport through supported liquid membranes; determination of transport parameters from a single transport experiment

    NARCIS (Netherlands)

    Chrisstoffels, L.A.J.; Struijk, Wilhelmina; de Jong, Feike; Reinhoudt, David

    1996-01-01

    This paper describes a time-dependent transport model for carrier assisted cation transport through supported liquid membranes. The model describes the flux of salt as a function of time and two parameters viz. the diffusion coefficient of the cation complex (D), and the extraction constant (Kex).

  20. Design parameters for voltage-controllable directed assembly of single nanoparticles

    NARCIS (Netherlands)

    Porter, Benjamin F.; Abelmann, Leon; Bhaskaran, Harish

    2013-01-01

    Techniques to reliably pick-and-place single nanoparticles into functional assemblies are required to incorporate exotic nanoparticles into standard electronic circuits. In this paper we explore the use of electric fields to drive and direct the assembly process, which has the advantage of being

  1. Laser-induced down-conversion parameters of singly and doubly ...

    Indian Academy of Sciences (India)

    Singly and doubly doped ZnS phosphors have been synthesized using flux method. Laser-induced photoluminescence has been observed in ZnS-doped phosphors when these were excited by the pulsed UV N2 laser radiation. Due to down-conversion phenomenon, fast phosphorescence emission in the visible region is ...

  2. 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.

  3. Stochastic analysis of uncertain thermal parameters for random thermal regime of frozen soil around a single freezing pipe

    Science.gov (United States)

    Wang, Tao; Zhou, Guoqing; Wang, Jianzhou; Zhou, Lei

    2018-03-01

    The artificial ground freezing method (AGF) is widely used in civil and mining engineering, and the thermal regime of frozen soil around the freezing pipe affects the safety of design and construction. The thermal parameters can be truly random due to heterogeneity of the soil properties, which lead to the randomness of thermal regime of frozen soil around the freezing pipe. The purpose of this paper is to study the one-dimensional (1D) random thermal regime problem on the basis of a stochastic analysis model and the Monte Carlo (MC) method. Considering the uncertain thermal parameters of frozen soil as random variables, stochastic processes and random fields, the corresponding stochastic thermal regime of frozen soil around a single freezing pipe are obtained and analyzed. Taking the variability of each stochastic parameter into account individually, the influences of each stochastic thermal parameter on stochastic thermal regime are investigated. The results show that the mean temperatures of frozen soil around the single freezing pipe with three analogy method are the same while the standard deviations are different. The distributions of standard deviation have a great difference at different radial coordinate location and the larger standard deviations are mainly at the phase change area. The computed data with random variable method and stochastic process method have a great difference from the measured data while the computed data with random field method well agree with the measured data. Each uncertain thermal parameter has a different effect on the standard deviation of frozen soil temperature around the single freezing pipe. These results can provide a theoretical basis for the design and construction of AGF.

  4. A single parameter representation of hygroscopic growth and cloud condensation nucleus activity – Part 2: Including solubility

    Directory of Open Access Journals (Sweden)

    M. D. Petters

    2008-10-01

    Full Text Available The ability of a particle to serve as a cloud condensation nucleus in the atmosphere is determined by its size, hygroscopicity and its solubility in water. Usually size and hygroscopicity alone are sufficient to predict CCN activity. Single parameter representations for hygroscopicity have been shown to successfully model complex, multicomponent particles types. Under the assumption of either complete solubility, or complete insolubility of a component, it is not necessary to explicitly include that component's solubility into the single parameter framework. This is not the case if sparingly soluble materials are present. In this work we explicitly account for solubility by modifying the single parameter equations. We demonstrate that sensitivity to the actual value of solubility emerges only in the regime of 2×10−1–5×10−4, where the solubility values are expressed as volume of solute per unit volume of water present in a saturated solution. Compounds that do not fall inside this sparingly soluble envelope can be adequately modeled assuming they are either infinitely soluble in water or completely insoluble.

  5. An Ambulatory Gait Monitoring System with Activity Classification and Gait Parameter Calculation Based on a Single Foot Inertial Sensor.

    Science.gov (United States)

    Song, Minsu; Kim, Jonghyun

    2018-04-01

    For healthcare and clinical use, ambulatory gait monitoring systems using inertial sensors have been developed to estimate the user gait parameters, such as walking speed, stride time, and stride length. However, to adapt the systems effectively to daily-life activities, they need to be able to classify the gait activities of daily-life to obtain the parameters for each activity. In this study, we propose a simple classification algorithm based on a single inertial sensor for ease of use, which classifies three major gait activities: leveled walk, ramp walk, and stair walk. The classification can be performed with gait parameter estimation simultaneously. The developed system that includes classification and parameter estimation algorithms was evaluated with eight healthy subjects within a gait lab and on an outdoor daily-life walking course. The results showed that the estimated gait parameters were comparable to existing studies (range of walking speed root mean square error: 0.059-0.129 m/s), and the classification accuracy was sufficiently high for all three gait activities: 98.5% for the indoor gait lab experiment and 95.5% for the outdoor complex daily-life walking course experiment. The proposed system is simple and effective for daily-life gait analysis, including gait activity classification and gait parameter estimation for each activity.

  6. Kriging-Based Parameter Estimation Algorithm for Metabolic Networks Combined with Single-Dimensional Optimization and Dynamic Coordinate Perturbation.

    Science.gov (United States)

    Wang, Hong; Wang, Xicheng; Li, Zheng; Li, Keqiu

    2016-01-01

    The metabolic network model allows for an in-depth insight into the molecular mechanism of a particular organism. Because most parameters of the metabolic network cannot be directly measured, they must be estimated by using optimization algorithms. However, three characteristics of the metabolic network model, i.e., high nonlinearity, large amount parameters, and huge variation scopes of parameters, restrict the application of many traditional optimization algorithms. As a result, there is a growing demand to develop efficient optimization approaches to address this complex problem. In this paper, a Kriging-based algorithm aiming at parameter estimation is presented for constructing the metabolic networks. In the algorithm, a new infill sampling criterion, named expected improvement and mutual information (EI&MI), is adopted to improve the modeling accuracy by selecting multiple new sample points at each cycle, and the domain decomposition strategy based on the principal component analysis is introduced to save computing time. Meanwhile, the convergence speed is accelerated by combining a single-dimensional optimization method with the dynamic coordinate perturbation strategy when determining the new sample points. Finally, the algorithm is applied to the arachidonic acid metabolic network to estimate its parameters. The obtained results demonstrate the effectiveness of the proposed algorithm in getting precise parameter values under a limited number of iterations.

  7. How attention influences perceptual decision making: Single-trial EEG correlates of drift-diffusion model parameters.

    Science.gov (United States)

    Nunez, Michael D; Vandekerckhove, Joachim; Srinivasan, Ramesh

    2017-02-01

    Perceptual decision making can be accounted for by drift-diffusion models, a class of decision-making models that assume a stochastic accumulation of evidence on each trial. Fitting response time and accuracy to a drift-diffusion model produces evidence accumulation rate and non-decision time parameter estimates that reflect cognitive processes. Our goal is to elucidate the effect of attention on visual decision making. In this study, we show that measures of attention obtained from simultaneous EEG recordings can explain per-trial evidence accumulation rates and perceptual preprocessing times during a visual decision making task. Models assuming linear relationships between diffusion model parameters and EEG measures as external inputs were fit in a single step in a hierarchical Bayesian framework. The EEG measures were features of the evoked potential (EP) to the onset of a masking noise and the onset of a task-relevant signal stimulus. Single-trial evoked EEG responses, P200s to the onsets of visual noise and N200s to the onsets of visual signal, explain single-trial evidence accumulation and preprocessing times. Within-trial evidence accumulation variance was not found to be influenced by attention to the signal or noise. Single-trial measures of attention lead to better out-of-sample predictions of accuracy and correct reaction time distributions for individual subjects.

  8. Growth, optical, thermal, mechanical and dielectric studies of sodium succinate hexahydrate (β phase) single crystal: A promising third order NLO material

    Science.gov (United States)

    Mageshwari, P. S. Latha; Priya, R.; Krishnan, S.; Joseph, V.; Das, S. Jerome

    2016-11-01

    A third order nonlinear optical (NLO)single crystals of sodium succinate hexahydrate (SSH) (β phase) has been grown by a slow evaporation growth technique using aqueous solution at ambient temperature. The lattice parameters and morphology of SSH were determined by single crystal X-ray diffraction analysis. SSH crystallizes in centrosymmetric monoclinic system with space group P 21 / c and the crystalline purity was analyzed by powder X-ray diffraction analysis. The UV-vis-NIR spectrum reveals that the crystal is transparent in the entire visible region. The recorded FT-IR spectrum verified the presence of various functional groups in the material. NMR analysis of the grown crystal confirms the structural elucidation and detects the major and minor functional groups present in the title compound. ICP-OES analysis proved the presence of sodium in SSH. TG-DTA/DSCanalysis was used to investigate the thermal stability of the material. The dielectric permittivity and dielectric loss of SSH were carried out as a function of frequency for different temperatures and the results were discussed. The mechanical stability was evaluated from Vicker's microhardness test. The third order nonlinear optical properties of SSH has been investigated employing Z-scan technique with He-Ne laser operating at 632.8 nm wavelength.

  9. A review of parameter estimation used in solar photovoltaic system for a single diode model

    Science.gov (United States)

    Sabudin, Siti Nurashiken Md; Jamil, Norazaliza Mohd; Rosli, Norhayati

    2017-09-01

    With increased demand for theoretical solar energy, the mathematical modelling of the solar photovoltaic (PV) system has gained importance. Numerous mathematical models have been developed for different purposes. In this paper, we briefly review the progress made in the mathematical modelling of solar photovoltaic (PV) system over the last twenty years. First, a general classification of these models is made. Then, the basic characteristics of the models along with the objectives and different parameters considered in modelling are discussed. The assumptions and approximations made also parameter estimation method in solving the models are summarized. This may facilitate the mathematicians to adopt better understanding of the modelling strategies and further to develop suitable models in this direction relevant to the present scenario.

  10. Single session of integrated "Silver Yoga" program improves cardiovascular parameters in senior citizens

    Directory of Open Access Journals (Sweden)

    Ananda Balayogi Bhavanani

    2015-06-01

    Conclusion: There is a healthy reduction in HR, BP and derived cardiovascular indices following a single yoga session in geriatric subjects. These changes may be attributed to enhanced harmony of cardiac autonomic function as a result of coordinated breath-body work and mind-body relaxation due to an integrated and #8220;Silver Yoga and #8221; program. [J Intercult Ethnopharmacol 2015; 4(2.000: 134-137

  11. Test-retest reliability of single and paired pulse transcranial magnetic stimulation parameters in healthy subjects.

    Science.gov (United States)

    Hermsen, A M; Haag, A; Duddek, C; Balkenhol, K; Bugiel, H; Bauer, S; Mylius, V; Menzler, K; Rosenow, F

    2016-03-15

    To determine the influence of different factors on test-retest reliability of frequently used transcranial magnetic stimulation (TMS) parameters while controlling for potential confounders in healthy subjects. TMS was applied in 93 healthy volunteers (61% male) twice (mean retest interval of 34.0 ± 25.6 (SD) days) between 7 am and 2 pm by four investigators (sessions n investigator A=47, investigator B=95, investigator C=28, investigator D=16). Women were assessed in their follicular phase. Test stimulus (TS), resting motor threshold (RMT), short latency intracortical inhibition (SICI), intracortical facilitation (ICF) and cortical silent period (SCP) were analyzed. Good test-retest reliabilities were observed for TS (r=.880) and RMT (r=.826), moderate for visual and automated analyzed CSP durations (resp. r=.466, r=.486), and poor for ICF (r=-.159). Reliable change indexes are reported. Gender (e.g. automated CSP women: r=.538 vs. men: r=.422), re-test interval and method of CSP-analysis did not influence reliabilities. In a large sample of healthy volunteers we found good to moderate test-retest reliabilities in all but one TMS-parameter. Automated analysis of the CSP did not prove to be more reliable than visual determination. This study contains analyses of re-test reliability in TMS considering several confounding factors. For the first time it presents reliable change indices for all frequently used TMS parameters. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Analysis and parameter identification for characteristic equations of single- and double-effect absorption chillers by means of multivariable regression

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; López-Villada, Jesús; Bruno, Joan Carles

    2010-01-01

    of the characteristic equation method developed by Kühn and Ziegler (2005) is the simplest and that it provides similar or better accuracy than the other approach. This selected approach has been used to fit catalogue and experimental data of single-effect chillers and has been extended to double-effect commercial......Two approaches to the characteristic equation method have been compared in order to find a simple model that best describes the performance of thermal chillers. After comparing the results obtained using experimental data from a single-effect absorption chiller, we concluded that the adaptation...

  13. Magnetic ordering in single crystals of PrBa sub 2 Cu sub 3 O sub 7 sub - subdelta

    CERN Document Server

    Uma, S; Gmelin, E; Rangarajan, G; Skanthakumar, S; Lynn, J W; Walter, R; Lorenz, T; Büchner, B; Walker, E; Erb, A

    1998-01-01

    Heat capacity measurements on pure but twinned single crystals of PrBa sub 2 Cu sub 3 O sub 7 sub - subdelta reveal a sharp peak at T sub N sup P sup sub T =16.6 K, which according to thermal expansion, neutron diffraction, and magnetic susceptibility measurements originates from an antiferromagnetic ordering of the Pr-ion moments. A modest coupling to the Cu(2) spin system is observed. Below T sub N sup P sup sub T a first-order transition in the magnetic structure of the Pr spin system (at 13.4 K in warming; approx. 11 K in cooling) is found. Field-dependent heat capacity data show anisotropic temperature dependences of the c sub p -peaks and recover a Schottky-like anomaly due to the crystal-field-split ground state of the Pr sup 3 sup +. (author). Letter-to-the-editor

  14. First-order phase transitions in CaFe2As2 single crystal: a local probe study

    International Nuclear Information System (INIS)

    Alzamora, M; Munevar, J; Baggio-Saitovitch, E; Bud'ko, S L; Ni Ni; Canfield, P C; Sanchez, D R

    2011-01-01

    57 Fe Moessbauer spectroscopy has been used to investigate the structural and magnetic phase transitions of CaFe 2 As 2 (T N = 173 K) single crystals. For this compound we found that V ZZ is positive and parallel to the c-axis of the tetragonal structure. For CaFe 2 As 2 a magnetic hyperfine field B hf was observed at the 57 Fe nucleus below T N ∼ 173 K. Analysis of the temperature dependence of B hf data using the Bean-Rodbell model shows that the Fe spins undergo a first-order magnetic transition at ∼ 173 K. A collinear antiferromagnetic structure is established below this temperature with the Fe spin lying in the (a, b) plane. Below T N the paramagnetic fraction of Fe decreases down to 150 K and for lower temperatures all the Fe spins are magnetically ordered.

  15. Significance of Al doping for antiferromagnetic AFII ordering in YBa2Cu3-xAlxO6+#delta# materials: A single-crystal neutron-diffraction study

    DEFF Research Database (Denmark)

    Brecht, E.; Schmahl, W.W.; Fuess, H.

    1995-01-01

    Aluminum-doped, oxygen-deficient YBa2Cu3-xAlxO6+delta single crystals with different Al contents x (0 less than or equal to x less than or equal to 0.19) and O contents (0.18 less than or equal to delta less than or equal to 0.36) were studied by magnetic neutron diffraction. All of the Al...... as the O content 6+delta in the x-delta region investigated so far. In a limited temperature interval the order parameter shows the components of both the AFI and AFII phases indicating competing interactions. For some crystals a complete reordering to the AFII phase at 4.2 K can be observed. Although...

  16. STUDY OF SINGLE WALLED CARBON NANOTUBE REINFORCED POLYMER COMPOSITES BY HANSEN SOLUBILITY PARAMETERS

    DEFF Research Database (Denmark)

    Ma, Jing

    transfer from polymer matrix to nanotube fillers is evaluated by Raman spectroscopy. The results are compared with the observation of the dispersion and Hansen Solubility Parameters. It is found that a good strain transfer can be obtained when the SWNTs are well dispersed and also when there is a good...... reinforcement of the polymer by the addition of SWNTs. Existence of agglomerates, voids, and the lower glass transition temperature of epoxy resin, may give the negative effect on the mechanical properties of nanocomposite materials. In the design aspect of the composite material, HSP could help match SWNTs...

  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. Growth and Characterization of Lithium Potassium Phthalate (LiKP) Single Crystals for Third Order Nonlinear Optical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, B.; Mohan, R. [Preidency College, Bangalore (India); Raj, S. Gokul [RR and Dr. SR Technical Univ., Avadi (India); Kumar, G. Ramesh [Anna Univ., Arni (India)

    2012-11-15

    Single crystals of lithium potassium phthalate (LiKP) were successfully grown from aqueous solution by solvent evaporation technique. The grown crystals were characterized by single crystal X-ray diffraction. The lithium potassium phthalate C{sub 16} H{sub 12} K Li{sub 3} O{sub 11} belongs to triclinic system with the following unit-cell dimensions at 298(2) K; a = 7.405(5) A; b = 9.878(5) A; c = 13.396(5) A; α = 71.778(5) .deg.; β = 87.300(5) .deg.; γ = 85.405(5) .deg.; having a space group P1. Mass spectrometric analysis provides the molecular weight of the compound and possible ways of fragmentations occurs in the compound. Thermal stability of the crystal was also studied by both simultaneous TGA/DTA analyses. The UV-Vis-NIR spectrum shows a good transparency in the whole of Visible and as well as in the near IR range. Third order nonlinear optical studies have also been studied by Z-scan technique. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also estimated.

  19. ESTIMATION OF THE SCALE PARAMETER FROM THE RAYLEIGH DISTRIBUTION FROM TYPE II SINGLY AND DOUBLY CENSORED DATA

    Directory of Open Access Journals (Sweden)

    Ahmad Saeed Akhter

    2009-01-01

    Full Text Available As common as the normal distribution is the Rayleigh distribution which occurs in works on radar, properties of sine wave plus-noise, etc. Rayleigh (1880 derived it from the amplitude of sound resulting from many important sources. The Rayleigh distribution is widely used in communication engineering, reliability analysis and applied statistics. Since the Rayleigh distribution has linearly increasing rate, it is appropriate for components which might not have manufacturing defects but age rapidly with time. Several types of electro-vacum devices have this feature. It is connected with one dimension and two dimensions random walk and is some times referred to as a random walk frequency distribution. It is a special case of Weibull distribution (1951 of wide applicability. It can be easily derived from the bivariate normal distribution with and p = 0. For further application of Rayleigh distribution, we refer to Johnson and Kotz (1994. Adatia (1995 has obtained the best linear unbiased estimator of the Rayleigh scale parameter based on fairly large censored samples. Dyer and Whisend (1973 obtained the BLUE of scale parameter based on type II censored samples for small N = 2(15. With the advance of computer technology it is now possible to obtain BLUE for large samples. Hirai (1978 obtained the estimate of the scale parameter from the Rayleigh distribution singly type II censored from the left side and right side and variances of the scale parameter. In this paper, we estimate the scale parameter of type II singly and doubly censored data from the Rayleigh distribution using Blom’s (1958 unbiased nearly best estimates and compare the efficiency of this estimate with BLUE and MLE.

  20. Structural and magnetic ordering of CrNb3S6 single crystals grown by gas transport method

    Science.gov (United States)

    Borisenko, E. B.; Berezin, V. A.; Kolesnikov, N. N.; Gartman, V. K.; Matveev, D. V.; Shakhlevich, O. F.

    2017-07-01

    Paramagnetic layered semiconductor NbS2 doped with some transition metals can transform into ferromagnetic material. That is why such materials are promising candidates for spintronic devices. It is found that only at certain concentrations of a doping metal T crystallographic ordering is possible, which is essential for magnetic ordering of ternary compounds TNbS2. In particular, CrNb3S6 crystals are studied, which form almost completely ordered superstructure with intercalated Cr between NbS2 layers. The main difficulty in crystal growth is reaching stoichiometry of the compound. This problem is solved in the developed method of two-staged gas transport chemical reaction. This new approach provides growth of CrNb3S6 single crystals of several millimeters in diameter and 0.3-0.5 mm thickness. X-ray phase analysis (XRD) of powders is performed to identify all phases involved in synthesis and growth of the crystals. High frequency absorption in external periodic magnetic field as a function of temperature and intensity of magnetic field is used to estimate the temperature of ferromagnetic transition in CrNb3S6 single crystals. The Curie temperature is estimated as 115 K. Growth of CrNb3S6 crystals from vapor phase is studied in detail and full analysis of phase transitions during growth is given. It has been shown that using of high frequency absorption in the crystal provides reliable estimation of the point of ferromagnetic transition in this semiconductor. The authors are grateful to the Physical Science Department of Russian Academy of Sciences for financial support of the studies in the frameworks of the program "Physics of new materials and structures" (project no. 00-12-10).

  1. A self-organizing state-space-model approach for parameter estimation in hodgkin-huxley-type models of single neurons.

    Directory of Open Access Journals (Sweden)

    Dimitrios V Vavoulis

    Full Text Available Traditional approaches to the problem of parameter estimation in biophysical models of neurons and neural networks usually adopt a global search algorithm (for example, an evolutionary algorithm, often in combination with a local search method (such as gradient descent in order to minimize the value of a cost function, which measures the discrepancy between various features of the available experimental data and model output. In this study, we approach the problem of parameter estimation in conductance-based models of single neurons from a different perspective. By adopting a hidden-dynamical-systems formalism, we expressed parameter estimation as an inference problem in these systems, which can then be tackled using a range of well-established statistical inference methods. The particular method we used was Kitagawa's self-organizing state-space model, which was applied on a number of Hodgkin-Huxley-type models using simulated or actual electrophysiological data. We showed that the algorithm can be used to estimate a large number of parameters, including maximal conductances, reversal potentials, kinetics of ionic currents, measurement and intrinsic noise, based on low-dimensional experimental data and sufficiently informative priors in the form of pre-defined constraints imposed on model parameters. The algorithm remained operational even when very noisy experimental data were used. Importantly, by combining the self-organizing state-space model with an adaptive sampling algorithm akin to the Covariance Matrix Adaptation Evolution Strategy, we achieved a significant reduction in the variance of parameter estimates. The algorithm did not require the explicit formulation of a cost function and it was straightforward to apply on compartmental models and multiple data sets. Overall, the proposed methodology is particularly suitable for resolving high-dimensional inference problems based on noisy electrophysiological data and, therefore, a

  2. 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.

  3. Growth and characterization of a single crystal of Urea Adipic acid (UAA) - A third order nonlinear optical material

    Science.gov (United States)

    Shanthi, A.; Krishnan, C.; Selvarajan, P.

    2014-03-01

    An organic single crystal of Urea Adipic acid (UAA) was successfully grown in methanol solvent by slow solvent evaporation technique at room temperature (30 °C). The structure of grown crystal was elucidated from the X-ray diffraction study and it belongs to monoclinic system with centrosymmetric space group P21/c. The optical transmission spectrum of UAA has been recorded and its theoretical calculations were carried out to determine the linear optical constants such as linear absorption coefficient, extinction coefficient, refractive index and reflectance etc. The third-order nonlinearities of UAA crystal have been investigated by Z-scan method. The values of nonlinear refractive index (n2), the absorption coefficient (β) and third-order nonlinear susceptibility (χ(3)) are found to be the order of 0.96 × 10-10 cm2/W, 1.248 × 10-4 cm/W and 6.44 × 10-8 esu respectively. Fourier Transform Infra Red and Raman spectroscopy studies reveal the intermolecular interactions present in the UAA sample. The dielectric and mechanical measurements of the title compound are also reported.

  4. Growth and characterization of a single crystal of Urea Adipic acid (UAA)--a third order nonlinear optical material.

    Science.gov (United States)

    Shanthi, A; Krishnan, C; Selvarajan, P

    2014-03-25

    An organic single crystal of Urea Adipic acid (UAA) was successfully grown in methanol solvent by slow solvent evaporation technique at room temperature (30 °C). The structure of grown crystal was elucidated from the X-ray diffraction study and it belongs to monoclinic system with centrosymmetric space group P21/c. The optical transmission spectrum of UAA has been recorded and its theoretical calculations were carried out to determine the linear optical constants such as linear absorption coefficient, extinction coefficient, refractive index and reflectance etc. The third-order nonlinearities of UAA crystal have been investigated by Z-scan method. The values of nonlinear refractive index (n2), the absorption coefficient (β) and third-order nonlinear susceptibility (χ((3))) are found to be the order of 0.96×10(-10) cm(2)/W, 1.248×10(-4) cm/W and 6.44×10(-8) esu respectively. Fourier Transform Infra Red and Raman spectroscopy studies reveal the intermolecular interactions present in the UAA sample. The dielectric and mechanical measurements of the title compound are also reported. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Single borehole test sensitivity towards crack and rock parameter. Lesson Hortberg; Einbohrlochtracertestsensitivitaet gegenueber Riss und Gesteinsparametern. Lektion Horstberg

    Energy Technology Data Exchange (ETDEWEB)

    Ghergut, Iulia; Behrens, Horst; Sauter, Martin [Goettingen Univ. (Germany). Angewandte Geologie

    2012-10-16

    The novel experiments of the GeoZentrum Hanover (Hanover, Federal Republic of Germany) on geothermal energy at the well bore Horstberg in the south heath also motivated the accompanying tracertest-mindset to move away from the tracer job stereotypes. For some possible designs at the tracertest at this drilling (forced-gradient divergent push by water fracking of Detfurth perforation, single-screen push-pull at Solling perforation, single-screen push-pull at Detfurth perforation, and so forth) the analysis shows how and why the controlling parameter do not comply with the mental basic pattern of the expectations at the tracertests ('tracertest by crack {yields} characterization of the crack', 'tracer residence time {yields} prognosis of the thermal lifetime').

  6. A novel single-step procedure for the calibration of the mounting parameters of a multi-camera terrestrial mobile mapping system

    Science.gov (United States)

    Habib, A.; Kersting, P.; Bang, K.; Rau, J.

    2011-12-01

    Mobile Mapping Systems (MMS) can be defined as moving platforms which integrates a set of imaging sensors and a position and orientation system (POS) for the collection of geo-spatial information. In order to fully explore the potential accuracy of such systems and guarantee accurate multi-sensor integration, a careful system calibration must be carried out. System calibration involves individual sensor calibration as well as the estimation of the inter-sensor geometric relationship. This paper tackles a specific component of the system calibration process of a multi-camera MMS - the estimation of the relative orientation parameters among the cameras, i.e., the inter-camera geometric relationship (lever-arm offsets and boresight angles among the cameras). For that purpose, a novel single step procedure, which is easy to implement and not computationally intensive, will be introduced. The proposed method is implemented in such a way that it can also be used for the estimation of the mounting parameters among the cameras and the IMU body frame, in case of directly georeferenced systems. The performance of the proposed method is evaluated through experimental results using simulated data. A comparative analysis between the proposed single-step and the two-step, which makes use of the traditional bundle adjustment procedure, is demonstrated.

  7. A detailed heterogeneous agent model for a single asset financial market with trading via an order book.

    Science.gov (United States)

    Mota Navarro, Roberto; Larralde, Hernán

    2017-01-01

    We present an agent based model of a single asset financial market that is capable of replicating most of the non-trivial statistical properties observed in real financial markets, generically referred to as stylized facts. In our model agents employ strategies inspired on those used in real markets, and a realistic trade mechanism based on a double auction order book. We study the role of the distinct types of trader on the return statistics: specifically, correlation properties (or lack thereof), volatility clustering, heavy tails, and the degree to which the distribution can be described by a log-normal. Further, by introducing the practice of "profit taking", our model is also capable of replicating the stylized fact related to an asymmetry in the distribution of losses and gains.

  8. Principle of single and multiple time interval analysis applicable to radioactive nuclides with half-lives of millisecond order

    International Nuclear Information System (INIS)

    Hashimoto, T.; Noguchi, M.; Washio, H.; Yamamoto, Y.; Uezu, Y.

    1992-01-01

    A delayed coincidence method has been developed for the selective extraction of radionuclides with half-lives of millisecond order using a personal computer. The time interval analysis is fundamentally based on the distinction of the time interval distribution between the correlated and random events, which arise from radioactive disintegration and/or background events within a certain fixed time. Theoretical functions of a time spectrum or a time distribution curve were dealt with from aspects of statistical treatments consisting of a single time interval analysis and a multiple one (STA and MTA). The theoretical equations obtained were used to simulate time spectra on the assumption of some ideal data and compared with the experimental results. Conclusively, the MTA method has been verified to be more suitable for the selective extraction of the objective correlated events from random or background events for the search of radioactive nuclides with millisecond life-times. (author) 11 refs.; 8 figs

  9. High-order modulation on a single discrete eigenvalue for optical communications based on nonlinear Fourier transform.

    Science.gov (United States)

    Gui, Tao; Lu, Chao; Lau, Alan Pak Tao; Wai, P K A

    2017-08-21

    In this paper, we experimentally investigate high-order modulation over a single discrete eigenvalue under the nonlinear Fourier transform (NFT) framework and exploit all degrees of freedom for encoding information. For a fixed eigenvalue, we compare different 4 bit/symbol modulation formats on the spectral amplitude and show that a 2-ring 16-APSK constellation achieves optimal performance. We then study joint spectral phase, spectral magnitude and eigenvalue modulation and found that while modulation on the real part of the eigenvalue induces pulse timing drift and leads to neighboring pulse interactions and nonlinear inter-symbol interference (ISI), it is more bandwidth efficient than modulation on the imaginary part of the eigenvalue in practical settings. We propose a spectral amplitude scaling method to mitigate such nonlinear ISI and demonstrate a record 4 GBaud 16-APSK on the spectral amplitude plus 2-bit eigenvalue modulation (total 6 bit/symbol at 24 Gb/s) transmission over 1000 km.

  10. Theoretical analysis and numerical simulation of electromagnetic parameters of Fe-C coaxial single fiber

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wei, E-mail: cslggncl@163.com [Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle, Hunan Province, Changsha University of Science and Technology, Changsha 410114 (China); Hunan Province Higher Education Key Laboratory of Modeling and Monitoring on the Near-Earth Electromagnetic Environments, Changsha University of Science & Technology, Changsha 410114 (China); College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Chemical and Biomolecular Engineering Department, University of Tennessee, Knoxville, TN 37996 (United States); Zhu, Xukun; Kuang, Jiacai [Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle, Hunan Province, Changsha University of Science and Technology, Changsha 410114 (China); Hunan Province Higher Education Key Laboratory of Modeling and Monitoring on the Near-Earth Electromagnetic Environments, Changsha University of Science & Technology, Changsha 410114 (China); Yi, Shihe; Cheng, Haifeng [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Guo, Zhanhu; He, Qingliang [Chemical and Biomolecular Engineering Department, University of Tennessee, Knoxville, TN 37996 (United States)

    2017-06-15

    Highlights: • Theoretical formula and calculation results of effective permeability and effective permittivity of the Fe-C coaxial fiber are obtained based on the Maxwell equation. • The coaxial fiber has stronger anisotropy and better electromagnetic dissipation performance than the hollow carbon fiber and solid iron fiber with the same volume content. • Greater conductivity, larger aspect ratio, thin iron shell play important roles to improve the electromagnetic matching ability and microwave attenuation for the Fe-C coaxial fibers. - Abstract: Based on the Maxwell equation, the electromagnetic model in the coaxial fiber was described. The interaction with electromagnetic wave was analysed and the theoretical formula of axial permeability (μ{sub ∥}), axial permittivity (ε{sub ∥}), radial permeability (μ{sub ⊥}) and radial permittivity (ε{sub ⊥}) of Fe-C coaxial fiber were derived, and the demagnetization factor (N) of fibrous material was revised. Calculation results indicate that the composite fiber has stronger anisotropy and better EM dissipation performance than the hollow carbon fiber and solid iron fiber with the same volume content. These properties can be enhanced through increasing aspect ratio and carbon content. The μ{sub ‖} is 5.18-4.46i, μ{sub ⊥} is 2.58-0.50i, ε{sub ∥} is 7.63-6.97i, and ε{sub ⊥} is 1.98-0.15i when the electromagnetic wave frequency is 5 GHz with the outer diameter of 0.866 μm, inner diameter of 0.500 μm, and length of 20 μm. The maximum of the imaginary part of μ{sub ∥} and ε{sub ∥} are much larger than that of μ{sub ⊥} and ε{sub ⊥} when the structural parameters change, and the maximum of μ{sub ∥} and ε{sub ∥} can reach 6.429 and 23.59. Simulation results show that greater conductivity, larger aspect ratio, thin iron shell play important roles to improve the electromagnetic matching ability and microwave attenuation for the Fe-C coaxial fibers.

  11. Synthesis, growth, crystal structure, optical and third order nonlinear optical properties of quinolinium derivative single crystal: PNQI

    Science.gov (United States)

    Karthigha, S.; Krishnamoorthi, C.

    2018-03-01

    An organic quinolinium derivative nonlinear optical (NLO) crystal, 1-ethyl-2-[2-(4-nitro-phenyl)-vinyl]-quinolinium iodide (PNQI) was synthesized and successfully grown by slow evaporation solution growth technique. Formation of a crystalline compound was confirmed by single crystal X-ray diffraction. The quinolinium compound PNQI crystallizes in the triclinic crystal system with a centrosymmetric space group of P-1 symmetry. The molecular structure of PNQI was confirmed by 1H NMR and 13C NMR spectral studies. The thermal properties of the crystal have been investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC) studies. The optical characteristics obtained from UV-Vis-NIR spectral data were described and the cut-off wavelength observed at 506 nm. The etching study was performed to analyse the growth features of PNQI single crystal. The third order NLO properties such as nonlinear refractive index (n2), nonlinear absorption coefficient (β) and nonlinear susceptibility (χ (3)) of the crystal were investigated using Z-scan technique at 632.8 nm of Hesbnd Ne laser.

  12. Growth and physicochemical properties of second-order nonlinear optical 2-amino-5-chloropyridinium trichloroacetate single crystals

    Science.gov (United States)

    Renugadevi, R.; Kesavasamy, R.

    2015-09-01

    The growth of organic nonlinear optical (NLO) crystal 2-amino-5-chloropyridinium trichloroacetate (2A5CPTCA) has been synthesized and single crystals have been grown from methanol solvent by slow evaporation technique. The grown crystals were subjected to various characterization analyses in order to find out the suitability for device fabrication. Single crystal X-ray diffraction analysis reveals that 2A5CPTCA crystallizes in monoclinic system with the space group Cc. The grown crystal was further characterized by Fourier transform infrared spectral analysis to find out the functional groups. The nuclear magnetic resonance spectroscopy is a research technique that exploits the magnetic properties of certain atomic nuclei. The optical transparency window in the visible and near-IR (200--1100 nm) regions was found to be good for NLO applications. Thermogravimetric analysis and differential thermal analysis were used to study its thermal properties. The powder second harmonic generation efficiency measurement with Nd:YAG laser (1064 nm) radiation shows that the highest value when compared with the standard potassium dihydrogen phosphate crystal.

  13. Single tracking location acoustic radiation force impulse viscoelasticity estimation (STL-VE): A method for measuring tissue viscoelastic parameters.

    Science.gov (United States)

    Langdon, Jonathan H; Elegbe, Etana; McAleavey, Stephen A

    2015-07-01

    Single tracking location (STL) shear wave elasticity imaging (SWEI) is a method for detecting elastic differences between tissues. It has the advantage of intrinsic speckle bias suppression compared with multiple tracking location variants of SWEI. However, the assumption of a linear model leads to an overestimation of the shear modulus in viscoelastic media. A new reconstruction technique denoted single tracking location viscosity estimation (STL-VE) is introduced to correct for this overestimation. This technique utilizes the same raw data generated in STL-SWEI imaging. Here, the STL-VE technique is developed by way of a maximum likelihood estimation for general viscoelastic materials. The method is then implemented for the particular case of the Kelvin-Voigt Model. Using simulation data, the STL-VE technique is demonstrated and the performance of the estimator is characterized. Finally, the STL-VE method is used to estimate the viscoelastic parameters of ex vivo bovine liver. We find good agreement between the STL-VE results and the simulation parameters as well as between the liver shear wave data and the modeled data fit.

  14. The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Z.

    1999-05-10

    This dissertation is concerned with the interplay of long-range order and anisotropy in the tetragonal RNi{sub 2}Ge{sub 2} (R = rare earth) family of compounds. Microscopic magnetic structures were studied using both neutron and x-ray resonant exchange scattering (XRES) techniques. The magnetic structures of Tb, Dy, Eu and Gd members have been determined using high-quality single-crystal samples. This work has correlated a strong Fermi surface nesting to the magnetic ordering in the RNi{sub 2}Ge{sub 2} compounds. Generalized susceptibility, {chi}{sub 0}(q), calculations found nesting to be responsible for both incommensurate ordering wave vector in GdNi{sub 2}Ge{sub 2}, and the commensurate structure in EuNi{sub 2}Ge{sub 2}. A continuous transition from incommensurate to commensurate magnetic structures via band filling is predicted. The surprisingly higher T{sub N} in EuNi{sub 2}Ge{sub 2} than that in GdNi{sub 2}Ge{sub 2} is also explained. Next, all the metamagnetic phases in TbNi{sub 2}Ge{sub 2} with an applied field along the c axis have been characterized with neutron diffraction measurements. A mixed phase model for the first metamagnetic structure consisting of fully-saturated as well as reduced-moment Tb ions is presented. The moment reduction may be due to moment instability which is possible if the exchange is comparable to the low-lying CEF level splitting and the ground state is a singlet. In such a case, certain Tb sites may experience a local field below the critical value needed to reach saturation.

  15. The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides

    International Nuclear Information System (INIS)

    Islam, Z.

    1999-01-01

    This dissertation is concerned with the interplay of long-range order and anisotropy in the tetragonal RNi 2 Ge 2 (R = rare earth) family of compounds. Microscopic magnetic structures were studied using both neutron and x-ray resonant exchange scattering (XRES) techniques. The magnetic structures of Tb, Dy, Eu and Gd members have been determined using high-quality single-crystal samples. This work has correlated a strong Fermi surface nesting to the magnetic ordering in the RNi 2 Ge 2 compounds. Generalized susceptibility, χ 0 (q), calculations found nesting to be responsible for both incommensurate ordering wave vector in GdNi 2 Ge 2 , and the commensurate structure in EuNi 2 Ge 2 . A continuous transition from incommensurate to commensurate magnetic structures via band filling is predicted. The surprisingly higher T N in EuNi 2 Ge 2 than that in GdNi 2 Ge 2 is also explained. Next, all the metamagnetic phases in TbNi 2 Ge 2 with an applied field along the c axis have been characterized with neutron diffraction measurements. A mixed phase model for the first metamagnetic structure consisting of fully-saturated as well as reduced-moment Tb ions is presented. The moment reduction may be due to moment instability which is possible if the exchange is comparable to the low-lying CEF level splitting and the ground state is a singlet. In such a case, certain Tb sites may experience a local field below the critical value needed to reach saturation

  16. Synthesis, optical, experimental and theoretical investigation of third order nonlinear optical properties of 8-hydroxyquinolinium 2-carboxy-6-nitrophthalate monohydrate single crystal

    Science.gov (United States)

    Bharathi, M. Divya; Bhuvaneswari, R.; Srividya, J.; Vinitha, G.; Prithiviraajan, R. N.; Anbalagan, G.

    2018-02-01

    Single crystals of 8-hydroxyquinolinium 2-carboxy-6-nitrophthalate monohydrate (8HQNP) were obtained from slow evaporation solution growth method using methanol-water (1:1) as a solvent. Powder X-ray diffraction was utilized to compute the unit cell parameters and dislocation density of 8HQNP crystal. The crystalline perfection of the as-grown crystal was investigated by high-resolution X-ray diffraction at room temperature. The molecular structure was analyzed by identifying the functional groups from FT-IR and FT-Raman spectra. The cut-off wavelength and the corresponding optical band gap obtained from an optical spectrum were 376 nm and 3.29 eV respectively. The dispersion nature of refractive index was investigated by the single-oscillator Wemple and Di-Domenico model. Red emission was observed in the photoluminescence spectrum when excited with 376 nm. The low birefringence and high laser damage threshold (8.538 GW/cm2) values dictate the suitability of the crystal for optical devices. Z-scan studies revealed the third order nonlinear absorption coefficient (β) and refractive index (n2) of the 8HQNP crystal. The theoretical value of third order nonlinear susceptibility obtained from density function theory is good accordance with the experimental value. The frontier molecular orbital energy gap decreases with increasing external electric field in different directions which attributed to the enhancement of the second hyperpolarizability. The grown title crystal is thermally stable up to 102 °C which was identified using thermal analysis. Mechanical strength of 8HQNP was estimated by using Vicker's microhardness studies.

  17. Performance and emission parameters of single cylinder diesel engine using castor oil bio-diesel blended fuels

    Science.gov (United States)

    Rahimi, A.; Ghobadian, B.; Najafi, G.; Jaliliantabar, F.; Mamat, R.

    2015-12-01

    The purpose of this study is to investigate the performance and emission parameters of a CI single cylinder diesel engine operating on biodiesel-diesel blends (B0, B5, B10, B15 and E20: 20% biodiesel and 80% diesel by volume). A reactor was designed, fabricated and evaluated for biodiesel production. The results showed that increasing the biodiesel content in the blend fuel will increase the performance parameters and decrease the emission parameters. Maximum power was detected for B0 at 2650 rpm and maximum torque was belonged to B20 at 1600 rpm. The experimental results revealed that using biodiesel-diesel blended fuels increased the power and torque output of the engine. For biodiesel blends it was found that the specific fuel consumption (sfc) was decreased. B10 had the minimum amount for sfc. The concentration of CO2 and HC emissions in the exhaust pipe were measured and found to be decreased when biodiesel blends were introduced. This was due to the high oxygen percentage in the biodiesel compared to the net diesel fuel. In contrast, the concentration of CO and NOx was found to be increased when biodiesel is introduced.

  18. THE EFFECT OF SINGLE NICKEL AND COMBINED NICKEL AND ZINC PERORAL ADMINISTRATION ON HAEMATOLOGICAL PARAMETERS IN RABBITS

    Directory of Open Access Journals (Sweden)

    Jana Emrichová

    2013-06-01

    Full Text Available The aim of this study was to determine the effect of single nickel (NiCl2 and nickel in combination with zinc (ZnCl2 on selected haematological parameters of rabbits: white blood cell, red blood cell, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelets, mean platelet volume, red cell distribution width, lymphocytes, monocytes, eosinophils, neutrophils, basophils. Twenty rabbits of broiler line Californian were used in this experiment. The animals were divided into the five groups, four animals in each ones (control group K and experimental groups E1, E2, E3 and E4. Animals were fed ad libitum using KKV1 feeding mixture (FM with or without nickel and zinc addition for 90 days follows: group E1 received 17.5 g of NiCl2.100 kg-1 FM; group E2 35 g NiCl2.100 kg-1 FM; group E3 17.5 g NiCl2 + 30 g ZnCl2.100 kg-1 FM and group E4 35 g NiCl2 + 30 g ZnCl2.100 kg-1 FM. The parameters were analysed using Advia – 120. Blood was collected into tubes containing anticoagulant agents K – EDTA. Statistical analyse showed a significant changes (P 0.05. Nickel has negative effect on some haematological parameters, but zinc can eliminates its influence.

  19. Growth and characterization of organic second order nonlinear optical (NLO) 4-chloroanilinium-L-tartrate monohydrate single crystals

    Science.gov (United States)

    Jeyaram, Jayaprakash; Varadharajan, Krishnakumar; Singaram, Boobas; Rajendhran, Ranjith

    2018-03-01

    The protonated organic single crystal of 4-chloroanilinium-L-tartrate monohydrate (4CALTM) was successfully grown by slow evaporation solution technique at room temperature. Powder X-ray diffraction confirmed the crystal system of the grown crystal and its lattice parameters were calculated. Microanalysis confirms the elemental compositions and the vibrations of the functional groups were confirmed by Fourier transform infrared (FTIR) spectroscopy technique. The grown crystal exhibits 65% of optical transparency in the 289-800 nm range and the optical bandgap was calculated. The dielectric constant and loss were studied as a function of frequency at different temperatures. The TG-DSC analysis shows the thermal stability of the grown crystal. Vickers hardness measurement reveals the mechanically soft nature of the crystal, and it obeys the reverse indentation size effect (RISE). The positive photoconductivity of the crystal was supported by a linear increase of photocurrent on illumination. Kurtz - Perry powder technique shows the second harmonic generation efficiency of a range of particles (25-300 μm) and the phasematching ability of the crystal.

  20. 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

  1. An enhanced unified uncertainty analysis approach based on first order reliability method with single-level optimization

    International Nuclear Information System (INIS)

    Yao, Wen; Chen, Xiaoqian; Huang, Yiyong; Tooren, Michel van

    2013-01-01

    In engineering, there exist both aleatory uncertainties due to the inherent variation of the physical system and its operational environment, and epistemic uncertainties due to lack of knowledge and which can be reduced with the collection of more data. To analyze the uncertain distribution of the system performance under both aleatory and epistemic uncertainties, combined probability and evidence theory can be employed to quantify the compound effects of the mixed uncertainties. The existing First Order Reliability Method (FORM) based Unified Uncertainty Analysis (UUA) approach nests the optimization based interval analysis in the improved Hasofer–Lind–Rackwitz–Fiessler (iHLRF) algorithm based Most Probable Point (MPP) searching procedure, which is computationally inhibitive for complex systems and may encounter convergence problem as well. Therefore, in this paper it is proposed to use general optimization solvers to search MPP in the outer loop and then reformulate the double-loop optimization problem into an equivalent single-level optimization (SLO) problem, so as to simplify the uncertainty analysis process, improve the robustness of the algorithm, and alleviate the computational complexity. The effectiveness and efficiency of the proposed method is demonstrated with two numerical examples and one practical satellite conceptual design problem. -- Highlights: ► Uncertainty analysis under mixed aleatory and epistemic uncertainties is studied. ► A unified uncertainty analysis method is proposed with combined probability and evidence theory. ► The traditional nested analysis method is converted to single level optimization for efficiency. ► The effectiveness and efficiency of the proposed method are testified with three examples

  2. Dual matrix ordered subsets reconstruction for accelerated 3D scatter compensation in single-photon emission tomography

    International Nuclear Information System (INIS)

    Kamphuis, C.; Beekman, F.J.; Van Rijk, P.P.; Viergever, M.A.

    1998-01-01

    Three-dimensional (3D) iterative maximum likelihood expectation maximization (ML-EM) algorithms for single-photon emission tomography (SPET) are capable of correcting image-degrading effects of non-uniform attenuation, distance-dependent camera response and patient shape-dependent scatter. However, the resulting improvements in quantitation, resolution and signal-to-noise ratio (SNR) are obtained at the cost of a huge computational burden. This paper presents a new acceleration method for ML-EM: dual matrix ordered subsets (DM-OS). DM-OS combines two acceleration methods: (a) different matrices for projection and back-projection and (b) ordered subsets of projections. DM-OS was compared with ML-EM on simulated data and on physical thorax phantom data, for both 180 and 360 orbits. Contrast, normalized standard deviation and mean squared error were calculated for the digital phantom experiment. DM-OS resulted in similar image quality to ML-EM, even for speed-up factors of 200 compared to ML-EM in the case of 120 projections. The thorax phantom data could be reconstructed 50 times faster (60 projections) using DM-OS with preservation of image quality. ML-EM and DM-OS with scatter compensation showed significant improvement of SNR compared to ML-EM without scatter compensation. Furthermore, inclusion of complex image formation models in the computer code is simplified in the case of DM-OS. It is thus shown that DM-OS is a fast and relatively simple algorithm for 3D iterative scatter compensation, with similar results to conventional ML-EM, for both 180 and 360 acquired data. (orig.)

  3. 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)

  4. Improving Wind Predictions in the Marine Atmospheric Boundary Layer through Parameter Estimation in a Single-Column Model

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jared A.; Hacker, Joshua P.; Delle Monache, Luca; Kosović, Branko; Clifton, Andrew; Vandenberghe, Francois; Rodrigo, Javier Sanz

    2016-12-14

    A current barrier to greater deployment of offshore wind turbines is the poor quality of numerical weather prediction model wind and turbulence forecasts over open ocean. The bulk of development for atmospheric boundary layer (ABL) parameterization schemes has focused on land, partly due to a scarcity of observations over ocean. The 100-m FINO1 tower in the North Sea is one of the few sources worldwide of atmospheric profile observations from the sea surface to turbine hub height. These observations are crucial to developing a better understanding and modeling of physical processes in the marine ABL. In this study, we use the WRF single column model (SCM), coupled with an ensemble Kalman filter from the Data Assimilation Research Testbed (DART), to create 100-member ensembles at the FINO1 location. The goal of this study is to determine the extent to which model parameter estimation can improve offshore wind forecasts.

  5. Comparative Study on Dispersion and Interfacial Properties of Single Walled Carbon Nanotube/Polymer Composites Using Hansen Solubility Parameters

    DEFF Research Database (Denmark)

    Ma, Jing; Larsen, Mikael

    2013-01-01

    Dispersion and interfacial strain transfer of single walled carbon nanotubes (SWNTs) are two major challenges for the utilization of SWNTs as reinforcements in polymer composites. Surface modifications could help change the dispersion and interfacial properties. In this study, nanocomposites were...... fabricated by solution blending 1 wt % SWNTs with various modification (nonmodified, nitric acid functionalized, and amine functionalized SWNTs) and three kinds of polymeric materials (polycarbonate, polyvinylidene fluoride, and epoxy). Chemical compatibilities between SWNTs and solvents or polymers...... are calculated by the Hansen solubility parameters (HSP) method. The dispersion of the SWNTs in solvents is evaluated by dynamic light scattering. The dispersion of SWNTs in polymers evaluated by a light optical microscope (LOM) generally agrees with the HSP prediction. The strain transfer from the matrix...

  6. Internal mechanical stresses and the thermodynamic and adhesion parameters of the metal condensate-single-crystal silicon system

    Science.gov (United States)

    Coman, B. P.; Juzevych, V. N.

    2012-07-01

    The kinetics of generation of internal mechanical stresses σ( d) in chromium, copper, gold, and aluminum thin films on single-crystal silicon substrates at different deposition rates has been experimentally investigated using the cantilever method. A two-step character of the variations in internal tensile stresses has been revealed. The regularities of the formation of the maximum level of mechanical stresses in the condensates under investigation have been established. The energy and adhesion parameters of chromium, copper, gold, and aluminum nanolayers on silicon, germanium, and nickel substrates have been studied using the macroscopic methods of surface physics. The interfacial energy, interfacial tension, work of adhesion, interfacial charge, and a new energy characteristic of the interfacial layer, namely, the energy of adhesive bonds, which exceeds the interfacial energy, have been determined.

  7. 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.

  8. Parameters influencing the fatigue life of a Cu–Al–Be single-crystal shape memory alloy under repeated bending

    International Nuclear Information System (INIS)

    Siredey-Schwaller, N; Eberhardt, A; Bastie, P

    2009-01-01

    One of the principal limitations in the use of shape memory alloys is certainly fatigue behaviour. Initially, the mechanical behaviour of polycrystals evolves during cycling and then rupture occurs after a relatively small number of cycles, in particular for deformation higher than a few per cent. If one replaces the polycrystal by a single crystal, one notices an important increase in the fatigue lifespan, mainly for high deformation (Siredey et al 2005 Mater. Sci. Eng. A 396 296–301). The aim of this study is to analyse the role of three parameters influencing the lifespan in mechanical fatigue. The first one relates to the atmosphere in which the test is carried out. No notable influence was found. However, for samples having spent 44 000 h in air, one notes a lifespan reduction for those tested in the presence of air, whereas it is normal for those tested under argon. In the second part, the effect of the surface state will be discussed. As already presented in Siredey et al (2005 Mater. Sci. Eng. A 396 296–301), surface roughness influences lifespan, especially for low imposed strain. However, for higher strain this effect is much less important. On the surface, striations due to martensitic transformations appear during cycling. However, the damage inside these striations seems not to be correlated to rupture. The third parameter relates to crystalline quality of the single crystal. It was studied with a hard x-ray diffractometer using a transposition at high energy of the Guinier–Tennevin method. Crystalline quality is found to play a crucial role in the lifespan in fatigue. The presence of sub-grains disoriented by about 1° and mosaicity can reduce the lifespan by a factor up to 10

  9. 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.

  10. Searching for stable Na-ordered phases in single-crystal samples of γ-NaxCoO2

    Science.gov (United States)

    Shu, G. J.; Prodi, Andrea; Chu, S. Y.; Lee, Y. S.; Sheu, H. S.; Chou, F. C.

    2007-11-01

    We report on the preparation and characterization of single-crystal γ phase NaxCoO2 with 0.25≤x≤0.84 using a nonaqueous electrochemical chronoamperemetry technique. By carefully mapping the overpotential versus x (for xfind six distinct stable phases with Na levels corresponding to xtilde 0.75, 0.71, 0.50, 0.43, 0.33, and 0.25. The composition with x≃0.55 appears to have a critical Na concentration which separates samples with different magnetic behavior as well as different Na ion diffusion mechanisms. Chemical analysis of an aged crystal reveals different Na ion diffusion mechanisms above and below xc˜0.53 , where the diffusion process above xc has a diffusion coefficient about five times larger than that below xc . The series of crystals were studied with x-ray diffraction, susceptibility, and transport measurements. The crystal with x=0.5 shows a weak ferromagnetic transition below T=27K in addition to the usual transitions at T=51 and 88K . The resistivity of the Curie-Weiss metallic Na0.71CoO2 composition has a very low residual resistivity, which attests to the high homogeneity of the crystals prepared by this improved electrochemical method. Our results on the various stable crystal compositions point to the importance of Na ion ordering across the phase diagram.

  11. Single-layer 2nd-order high-T{sub c} SQUID gradiometer for use in unshielded environments

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soon-Gul; Park, Seung Moon; Kang, Chan Seok [Korea University, Chungnam (Korea, Republic of); Kim, In-Seon [Korea Research Institute of Standards and Science, Daejon (Korea, Republic of); Kim, Sang-Jae [Cheju National University, Cheju (Korea, Republic of)

    2006-05-15

    We have studied the fabrication of second-order SQUID gradiometers from single-layer high-T{sub c} film and the feasibility of using those gradiometers in magnetocardiography. The gradiometer contains three parallel-connected pickup loops that are directly coupled to a step-edge junction SQUID with the coupling polarity of the center loop opposite to those of the two side loops. For a well-balanced gradiometer with a balancing factor of 10{sup 3}, we achieved an unshielded gradient noise of 0.84 pT/cm{sup 2}/Hz{sup 1/2} at 1 Hz, which corresponds to an equivalent field noise of 280 fT/Hz{sup 1/2}. A gradiometer with a 5.8-mm baseline successfully recorded the magnetocardic signals of a human subject, demonstrating the feasibility of using the device in biomagnetism. We have also studied the use of submicron YBCO bridges as Josephson elements of long-baseline gradiometers. The bridges were fabricated from 3-{mu}m-wide, 300-nm-thick YBCO lines with a thin layer of Au on top by using a focused-ion-beam (FIB) patterning method. The temperature-dependent critical currents, I{sub c}(T), and the normal state resistances, R{sub N}(T), showed SIS-type behaviors, which are believed to be due to naturally formed grain boundaries.

  12. Single-layer 2nd-order high-Tc SQUID gradiometer for use in unshielded environments

    International Nuclear Information System (INIS)

    Lee, Soon-Gul; Park, Seung Moon; Kang, Chan Seok; Kim, In-Seon; Kim, Sang-Jae

    2006-01-01

    We have studied the fabrication of second-order SQUID gradiometers from single-layer high-T c film and the feasibility of using those gradiometers in magnetocardiography. The gradiometer contains three parallel-connected pickup loops that are directly coupled to a step-edge junction SQUID with the coupling polarity of the center loop opposite to those of the two side loops. For a well-balanced gradiometer with a balancing factor of 10 3 , we achieved an unshielded gradient noise of 0.84 pT/cm 2 /Hz 1/2 at 1 Hz, which corresponds to an equivalent field noise of 280 fT/Hz 1/2 . A gradiometer with a 5.8-mm baseline successfully recorded the magnetocardic signals of a human subject, demonstrating the feasibility of using the device in biomagnetism. We have also studied the use of submicron YBCO bridges as Josephson elements of long-baseline gradiometers. The bridges were fabricated from 3-μm-wide, 300-nm-thick YBCO lines with a thin layer of Au on top by using a focused-ion-beam (FIB) patterning method. The temperature-dependent critical currents, I c (T), and the normal state resistances, R N (T), showed SIS-type behaviors, which are believed to be due to naturally formed grain boundaries.

  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. 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

  15. Integration of Single-Center Data-Driven Vital Sign Parameters into a Modified Pediatric Early Warning System.

    Science.gov (United States)

    Ross, Catherine E; Harrysson, Iliana J; Goel, Veena V; Strandberg, Erika J; Kan, Peiyi; Franzon, Deborah E; Pageler, Natalie M

    2017-05-01

    Pediatric early warning systems using expert-derived vital sign parameters demonstrate limited sensitivity and specificity in identifying deterioration. We hypothesized that modified tools using data-driven vital sign parameters would improve the performance of a validated tool. Retrospective case control. Quaternary-care children's hospital. Hospitalized, noncritically ill patients less than 18 years old. Cases were defined as patients who experienced an emergent transfer to an ICU or out-of-ICU cardiac arrest. Controls were patients who never required intensive care. Cases and controls were split into training and testing groups. The Bedside Pediatric Early Warning System was modified by integrating data-driven heart rate and respiratory rate parameters (modified Bedside Pediatric Early Warning System 1 and 2). Modified Bedside Pediatric Early Warning System 1 used the 10th and 90th percentiles as normal parameters, whereas modified Bedside Pediatric Early Warning System 2 used fifth and 95th percentiles. The training set consisted of 358 case events and 1,830 controls; the testing set had 331 case events and 1,215 controls. In the sensitivity analysis, 207 of the 331 testing set cases (62.5%) were predicted by the original tool versus 206 (62.2%; p = 0.54) with modified Bedside Pediatric Early Warning System 1 and 191 (57.7%; p Early Warning System 2. For specificity, 1,005 of the 1,215 testing set control patients (82.7%) were identified by original Bedside Pediatric Early Warning System versus 1,013 (83.1%; p = 0.54) with modified Bedside Pediatric Early Warning System 1 and 1,055 (86.8%; p Early Warning System 2. There was no net gain in sensitivity and specificity using either of the modified Bedside Pediatric Early Warning System tools. Integration of data-driven vital sign parameters into a validated pediatric early warning system did not significantly impact sensitivity or specificity, and all the tools showed lower than desired sensitivity and

  16. Temporal and spatial gait parameters in children with Cri du Chat Syndrome under single and dual task conditions.

    Science.gov (United States)

    Abbruzzese, Laurel D; Salazar, Rachel; Aubuchon, Maddie; Rao, Ashwini K

    2016-10-01

    To describe temporal and spatial gait characteristics in individuals with Cri du Chat syndrome (CdCS) and to explore the effects of performing concurrent manual tasks while walking. The gait parameters of 14 participants with CdCS (mean age 10.3, range 3-20 years) and 14 age-matched controls (mean age 10.1, range 3-20 years) were collected using the GAITRite ® instrumented walkway. All participants first walked without any concurrent tasks and then performed 2 motor dual task walking conditions (pitcher and tray). Individuals with CdCS took more frequent, smaller steps than controls, but, on average, had a comparable gait speed. In addition, there was a significant task by group interaction. Participants decreased gait speed, decreased cadence, decreased step length, and increased% time in double limb support under dual task conditions compared to single task conditions. However, the age-matched controls altered their gait for both manual tasks, and the participants with CdCS only altered their gait for the tray task. Although individuals with CdCS ambulate with a comparable gait speed to age-matched controls under single task conditions, they did not significantly alter their gait when carrying a pitcher with a cup of water inside, like controls. It is not clear whether or not individuals with CdCS had difficulty attending to task demands or had difficulty modifying their gait. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Different aspects of sartan + calcium antagonist association compared to the single therapy on inflammation and metabolic parameters in hypertensive patients.

    Science.gov (United States)

    Derosa, Giuseppe; Cicero, Arrigo F G; Carbone, Anna; Querci, Fabrizio; Fogari, Elena; D'Angelo, Angela; Maffioli, Pamela

    2014-02-01

    This study aims to evaluate the effects of an angiotensin receptor blocker (ARB)/calcium channel blocker combination on blood pressure control, lipid profile, insulin sensitivity, and inflammation markers. We randomized 276 hypertensive patients to olmesartan 20 mg, amlodipine 10 mg, or a single pill containing an olmesartan/amlodipine combination 20/5 mg for 12 months. We evaluated the following: body weight, systolic and diastolic blood pressure, fasting plasma glucose, fasting plasma insulin (FPI), M value, lipid profile, adiponectin (ADN), high sensitivity C-reactive protein (Hs-CRP), monocyte chemoattractant protein-1 (MCP-1), and macrophage migration inhibitory factor-1β (MIP-1β). Olmesartan/amlodipine combination better reduced blood pressure, FPI, homeostasis model assessment index, and increased M value and ADN compared to olmesartan and amlodipine monotherapies. Olmesartan/amlodipine significantly decreased Hs-CRP, MCP-1, and MIP-1β. In this multicenter, randomized, double-blind, clinical study, ARB/calcium antagonist combination resulted to be more effective than single monotherapies in reducing blood pressure, in improving insulin sensitivity, and in reducing inflammation parameters in patients with stage I essential hypertension.

  18. Influence of cutting parameters on the depth of subsurface deformed layer in nano-cutting process of single crystal copper.

    Science.gov (United States)

    Wang, Quanlong; Bai, Qingshun; Chen, Jiaxuan; Su, Hao; Wang, Zhiguo; Xie, Wenkun

    2015-12-01

    Large-scale molecular dynamics simulation is performed to study the nano-cutting process of single crystal copper realized by single-point diamond cutting tool in this paper. The centro-symmetry parameter is adopted to characterize the subsurface deformed layers and the distribution and evolution of the subsurface defect structures. Three-dimensional visualization and measurement technology are used to measure the depth of the subsurface deformed layers. The influence of cutting speed, cutting depth, cutting direction, and crystallographic orientation on the depth of subsurface deformed layers is systematically investigated. The results show that a lot of defect structures are formed in the subsurface of workpiece during nano-cutting process, for instance, stair-rod dislocations, stacking fault tetrahedron, atomic clusters, vacancy defects, point defects. In the process of nano-cutting, the depth of subsurface deformed layers increases with the cutting distance at the beginning, then decreases at stable cutting process, and basically remains unchanged when the cutting distance reaches up to 24 nm. The depth of subsurface deformed layers decreases with the increase in cutting speed between 50 and 300 m/s. The depth of subsurface deformed layer increases with cutting depth, proportionally, and basically remains unchanged when the cutting depth reaches over 6 nm.

  19. 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

  20. 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.

  1. Laws of evolution of slip trace pattern and its parameters with deformation in [1.8.12] – single crystals of Ni{sub 3}Fe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Teplyakova, Ludmila, E-mail: lat168@mail.ru; Koneva, Nina, E-mail: koneva@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya sq., 634003, Tomsk (Russian Federation); Kunitsyna, Tatyana, E-mail: kma11061990@mail.ru [Tomsk State University of Architecture and Building, 2, Solyanaya sq., 634003, Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30, Lenin Str., 634050, Tomsk (Russian Federation)

    2016-01-15

    The slip trace pattern of Ni{sub 3}Fe alloy single crystals with the short range order oriented for a single slip were investigated on replica at different stages of deformation using the transmission diffraction electron microscopy method. The connection of staging with the formation of slip trace pattern and the change of its parameters were established. The number of local areas where two or more slip systems work is increased with the change of stages. In these conditions the character of slip localization in the primary slip system is changed from the packets to the homogeneous distribution. The distributions of the distances between slip traces and the shear power in slip traces were plotted. The correlation between the average value of the shear power in the primary slip traces and the average distance between them was revealed in this work. It was established that the rates of the average value growth of the relative local shear and the shear power in the slip traces reach the largest values at the transition stage.

  2. Crystal growth and characterization of semi-organic 2-amino-5-nitropyridinium bromide (2A5NPBr) single crystals for third-order nonlinear optical (NLO) applications

    Science.gov (United States)

    Vediyappan, Sivasubramani; Arumugam, Raja; Pichan, Karuppasamy; Kasthuri, Ramachandran; Muthu, Senthil Pandian; Perumal, Ramasamy

    2017-12-01

    Semi-organic nonlinear optical (NLO) 2-amino-5-nitropyridinium bromide (2A5NPBr) single crystals have been grown by slow evaporation solution technique (SEST) with the growth period of 60 days. The single-crystal XRD analysis confirms the unit cell parameters of the grown crystal. The crystallinity of grown 2A5NPBr was analyzed by powder X-ray diffraction (PXRD) measurement. The presence of functional groups of 2A5NPBr crystal was confirmed by Fourier transform infrared (FTIR) spectrum analysis. The optical transmittance of the grown crystal was analyzed by UV-Vis-NIR analysis. It shows good transparency in the visible and NIR region and it is favorable for nonlinear optical (NLO) device applications. The chemical etching study was carried out and it reveals that the grown crystal has less dislocation density. The photoconductivity study reveals that the grown crystal possesses positive photoconductive nature. The thermal stability of the crystal has been investigated by thermogravimetric (TG) and differential thermal analysis (DTA). The dielectric constant and dielectric loss as a function of frequency were measured. The electronic polarizability (α) of 2A5NPBr molecule has been calculated theoretically by different ways such as Penn analysis, Clausius-Mossotti relation, Lorentz-Lorenz equation, optical bandgap, and coupled dipole method (CDM). The obtained values of electronic polarizability (α) are in good agreement with each other. Laser damage threshold (LDT) of 2A5NPBr crystal has been measured using Nd:YAG laser with the wavelength of 1064 nm. Third-order nonlinear optical property of the grown crystal was studied by Z-scan technique using He-Ne laser of wavelength 632.8 nm.

  3. High-pressure single-crystal neutron scattering study of magnetic and Fe vacancy orders in (Tl,Rb)2Fe4Se5 superconductor

    OpenAIRE

    Ye, Feng; Bao, Wei; Chi, Songxue; Santos, Antonio M. dos; Molaison, Jamie J.; Fang, Minghu; Wang, Hangdong; Wang, Qianhui Mao Jinchen; Liu, Juanjuan; Sheng, Jieming

    2014-01-01

    The magnetic and iron vacancy orders in superconducting (Tl,Rb)2Fe4Se5 single-crystals are investigated by using a high-pressure neutron diffraction technique. Similar to the temperature effect, the block antiferromagnetic order gradually decreases upon increasing pressure while the Fe vacancy superstructural order remains intact before its precipitous disappearance at the critical pressure Pc = 8.3 GPa. Combined with previously determined Pc for superconductivity, our phase diagram under pre...

  4. A Parameter Study of Coupling Properties in Finite Element Models of Single-Stud Double-Plate Panels

    DEFF Research Database (Denmark)

    Dickow, Kristoffer Ahrens; Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard

    2011-01-01

    Lightweight building techniques are currently progressing fast and using such structures for multi-storey multi-family dwellings is becoming part of the industry standard. Partitions in lightweight buildings are often constructed as plates on frame structures made of either wood or steel. In any...... case the low frequency sound transmission is often an issue that needs attention. The present paper utilizes a finite element model of a single-stud double-plate panel structure to investigate how different couplings between the plates and the frame structure affect the direct sound transmission. Four...... and the load acts as a diffuse field on one side of the panel. The obtained results indicate that in order to accurately model sound transmission through a double-plate panel structure, the choice of coupling is an important factor....

  5. 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.

  6. 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)

  7. 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.

  8. Single-vehicle crashes along rural mountainous highways in Malaysia: An application of random parameters negative binomial model.

    Science.gov (United States)

    Rusli, Rusdi; Haque, Md Mazharul; King, Mark; Voon, Wong Shaw

    2017-05-01

    Mountainous highways generally associate with complex driving environment because of constrained road geometries, limited cross-section elements, inappropriate roadside features, and adverse weather conditions. As a result, single-vehicle (SV) crashes are overrepresented along mountainous roads, particularly in developing countries, but little attention is known about the roadway geometric, traffic and weather factors contributing to these SV crashes. As such, the main objective of the present study is to investigate SV crashes using detailed data obtained from a rigorous site survey and existing databases. The final dataset included a total of 56 variables representing road geometries including horizontal and vertical alignment, traffic characteristics, real-time weather condition, cross-sectional elements, roadside features, and spatial characteristics. To account for structured heterogeneities resulting from multiple observations within a site and other unobserved heterogeneities, the study applied a random parameters negative binomial model. Results suggest that rainfall during the crash is positively associated with SV crashes, but real-time visibility is negatively associated. The presence of a road shoulder, particularly a bitumen shoulder or wider shoulders, along mountainous highways is associated with less SV crashes. While speeding along downgrade slopes increases the likelihood of SV crashes, proper delineation decreases the likelihood. Findings of this study have significant implications for designing safer highways in mountainous areas, particularly in the context of a developing country. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Previously Unidentified Single Nucleotide Polymorphisms in HIV/AIDS Cases Associate with Clinical Parameters and Disease Progression

    Directory of Open Access Journals (Sweden)

    Vladimir V. Anokhin

    2016-01-01

    Full Text Available The genetic background of an individual plays an important role in the progression of HIV infection to AIDS. Identifying previously unknown or uncharacterized single nucleotide polymorphisms (SNPs that associate with disease progression may reveal important therapeutic targets and provide a greater understanding of disease pathogenesis. In the present study, we employed ultra-high multiplex PCR on an Ion Torrent next-generation sequencing platform to sequence 23 innate immune genes from 94 individuals with HIV/AIDS. This data was used to identify potential associations of SNPs with clinical parameters and disease progression. SNPs that associated with an increased viral load were identified in the genes for the interleukin 15 receptor (IL15RA, toll-like receptor 7 (TLR7, tripartite motif-containing protein 5 (TRIM5, and two killer-cell immunoglobulin-like receptors (KIR2DL1 and KIR2DL3. Additionally, SNPs that associated with progression from HIV infection to AIDS were identified in two 2′-5′-oligoadenylate synthetase genes (OAS2 and OAS3. In contrast, other SNPs identified in OAS2 and OAS3 genes, as well as in the TRIM5 and KIR2DS4 genes, were associated with a slower progression of disease. Taken together, our data demonstrates the utility of ultra-high multiplex PCR in identifying polymorphisms of potential clinical significance and further,identifies SNPs that may play a role in HIV pathogenesis.

  10. Aerosol single-scattering albedo and asymmetry parameter from MFRSR observations during the ARM Aerosol IOP 2003

    Directory of Open Access Journals (Sweden)

    E. I. Kassianov

    2007-06-01

    Full Text Available Multi-filter Rotating Shadowband Radiometers (MFRSRs provide routine measurements of the aerosol optical depth (τ at six wavelengths (0.415, 0.5, 0.615, 0.673, 0.870 and 0.94 μm. The single-scattering albedo (π0 is typically estimated from the MFRSR measurements by assuming the asymmetry parameter (g. In most instances, however, it is not easy to set an appropriate value of g due to its strong temporal and spatial variability. Here, we introduce and validate an updated version of our retrieval technique that allows one to estimate simultaneously π0 and g for different types of aerosol. We use the aerosol and radiative properties obtained during the Atmospheric Radiation Measurement (ARM Program's Aerosol Intensive Operational Period (IOP to validate our retrieval in two ways. First, the MFRSR-retrieved optical properties are compared with those obtained from independent surface, Aerosol Robotic Network (AERONET, and aircraft measurements. The MFRSR-retrieved optical properties are in reasonable agreement with these independent measurements. Second, we perform radiative closure experiments using the MFRSR-retrieved optical properties. The calculated broadband values of the direct and diffuse fluxes are comparable (~5 W/m2 to those obtained from measurements.

  11. Single- and multi-layered all-dielectric ENG, MNG, and DNG material parameter extraction by use of the S-parameter method

    DEFF Research Database (Denmark)

    Wu, Yunqiu; Arslanagic, Samel

    2016-01-01

    The multi-layer two-dimensional(2-D) epsilon-negative (ENG), mu-negative (MNG) and double-negative (DNG) materials are investigated in this work. The unit cells consist of infinite dielectric cylinders of which the size and permittivity are chosen to excite the dominant electric and magnetic dipole...... modes inside the structure. This enables the ENG, MNG, and DNG behaviors. The material parameters are obtained from the simulated S-parameters by use of the Nicholson-Ross-Weir method. For the 2-layer structure in particular, the results show a possibility of DNG realization with a negative refractive...

  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. Non-Synonymous Single-Nucleotide Polymorphisms and Physical Activity Interactions on Adiposity Parameters in Malaysian Adolescents

    Directory of Open Access Journals (Sweden)

    Nur Lisa Zaharan

    2018-04-01

    Full Text Available BackgroundSeveral non-synonymous single-nucleotide polymorphisms (nsSNPs have been shown to be associated with obesity. Little is known about their associations and interactions with physical activity (PA in relation to adiposity parameters among adolescents in Malaysia.MethodsWe examined whether (a PA and (b selected nsSNPs are associated with adiposity parameters and whether PA interacts with these nsSNPs on these outcomes in adolescents from the Malaysian Health and Adolescents Longitudinal Research Team study (n = 1,151. Body mass indices, waist–hip ratio, and percentage body fat (% BF were obtained. PA was assessed using Physical Activity Questionnaire for Older Children (PAQ-C. Five nsSNPs were included: beta-3 adrenergic receptor (ADRB3 rs4994, FABP2 rs1799883, GHRL rs696217, MC3R rs3827103, and vitamin D receptor rs2228570, individually and as combined genetic risk score (GRS. Associations and interactions between nsSNPs and PAQ-C scores were examined using generalized linear model.ResultsPAQ-C scores were associated with % BF (β = −0.44 [95% confidence interval −0.72, −0.16], p = 0.002. The CC genotype of ADRB3 rs4994 (β = −0.16 [−0.28, −0.05], corrected p = 0.01 and AA genotype of MC3R rs3827103 (β = −0.06 [−0.12, −0.00], p = 0.02 were significantly associated with % BF compared to TT and GG genotypes, respectively. Significant interactions with PA were found between ADRB3 rs4994 (β = −0.05 [−0.10, −0.01], p = 0.02 and combined GRS (β = −0.03 [−0.04, −0.01], p = 0.01 for % BF.ConclusionHigher PA score was associated with reduced % BF in Malaysian adolescents. Of the nsSNPs, ADRB3 rs4994 and MC3R rs3827103 were associated with % BF. Significant interactions with PA were found for ADRB3 rs4994 and combined GRS on % BF but not on measurements of weight or circumferences. Targeting body fat represent prospects for molecular studies and lifestyle intervention

  14. Dynamics of Nonlinear Excitation of the High-Order Mode in a Single-Mode Step-Index Optical Fiber

    Science.gov (United States)

    Burdin, V.; Bourdine, A.

    2018-04-01

    This work is concerned with approximate model of higher-order mode nonlinear excitation in a singlemode silica optical fiber. We present some results of simulation for step-index optical fiber under femtosecond optical pulse launching, which confirm ability of relatively stable higher-order mode excitation in such singlemode optical fiber over sufficiently narrow range of launched optical power variation.

  15. Proposal for arbitrary-order temporal integration of ultrafast optical signals using a single uniform-period fiber Bragg grating.

    Science.gov (United States)

    Asghari, Mohammad H; Azaña, José

    2008-07-01

    A simple and practical all-fiber design for implementing arbitrary-order temporal integration of ultrafast optical waveforms is proposed and numerically investigated. We demonstrate that an ultrafast photonics integrator of any desired integration order can be implemented using a uniform-period fiber Bragg grating (FBG) with a properly designed amplitude-only grating apodization profile. In particular, the grating coupling strength must vary according to the (N-1) power of the fiber distance for implementing an Nth-order photonics integrator (N=1,2,...). This approach requires the same level of practical difficulty for realizing any given integration order. The proposed integration devices operate over a limited time window, which is approximately fixed by the round-trip propagation time in the FBG. Ultrafast arbitrary-order all-optical integrators capable of accurate operation over nanosecond time windows can be implemented using readily feasible FBGs.

  16. 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

  17. Whispering Gallery mode ESR spectroscopy and parameters measurement in single crystal SrLaAlO4at millikelvin temperature.

    Science.gov (United States)

    Hosain, M A; Le Floch, J-M; Krupka, J; Tobar, M E

    2017-08-01

    A cylindrical single crystal SrLaAlO 4 Whispering Gallery mode dielectric resonator was cooled to millikelvin temperature using a dilution refrigerator. By controlling a DC-magnetic field, impurity ions' spins were coupled to a variety of modes allowing the measurement of hybrid spin-photon systems. This Electron Spin Resonance mapping technique allowed us to detect Cu 2+ ,Fe 3+ and Mn 4+ impurity ions (at the level of parts per million (ppm) to parts per billion (ppb)), verified by the measurement of the spin parameters along with their site symmetry. Whispering Gallery modes exhibited Q-factors ⩾10 5 at a temperature less than 20mK, allowing sensitive spectroscopy with high precision. Measured hyperfine line constants of the Cu 2+ ion shows different parallel g-factors, g ‖Cu , of 2.526,2.375,2.246 and 2.142. The spin-orbit coupling constant of the Cu 2+ ion was determined to be λ≃-635cm -1 . The low-spin state Fe 3+ ion's measured parallel g-factor, g ‖Fe , of 2.028 reveals tetragonal anisotropy. The Mn 4+ ion is identified in the lattice, producing hyperfine structure with high-valued g-factors,g ‖Mn , of 7.789,7.745,7.688,7.613,7.5304 and 7.446. The hyperfine structures of the Cu 2+ and Mn 4+ ions show broadening of about 79G between 9.072GHz and 10.631GHz, and 24.5G broadening between 9.072GHz and 14.871GHz, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The Effect of Different Types of Physical Exercise on the Behavioural and Physiological Parameters of Standardbred Horses Housed in Single Stalls

    Directory of Open Access Journals (Sweden)

    Barbara Padalino

    2014-01-01

    Full Text Available The aim of this study was to investigate the impacts of three different physical exercises on the physiological and behavioural patterns of Standardbred trotters housed in single stalls. Twelve racing mares were observed twice during each different exercise: daily training (DT consisted of forty minutes at slow trot (4-5 m/s in a small track; maximal exercise (ME consisted of 1600 m run at maximal velocity; race (R was a real race of 1600 m. The mares were examined at rest in their stall (Time I, soon after the completion of the exercise (Time II, one hour (Time III, and two hours (Time IV after the exercise. Their heart rate, respiratory rate, and rectal temperature were recorded and they were videotaped in order to complete a focal animal sampling ethogram. All physiological parameters increased after exercise, in accordance with its intensity. After R and ME horses spent more time drinking, eating, and standing. The incidence of abnormal behaviours was very low and it was not affected by the different types of exercise. Overall, the assessment of horse behaviour after physical exercise by means of a focal animal sampling ethogram represents a useful tool to monitor equine welfare.

  19. Unified Scattering Parameters formalism in terms of Coupled-Mode Theory for investigating hybrid single-mode/two-mode photonic interconnects

    Directory of Open Access Journals (Sweden)

    Boucher Yann G.

    2017-01-01

    Full Text Available In terms of Linear Algebra, a directional coupler between a single-mode waveguide and a two-mode waveguide can be thought of as formally equivalent to a set of three mutually coupled single-mode waveguides. Its responses, easily derived in the frame of ternary Coupled-Mode Theory, are used to establish analytically the scattering parameters of a hybrid ring-based modal multiplexer.

  20. Single crystal growth and structural evolution across the 1st order valence transition in (Pr1-yYy)1-xCaxCoO3-δ

    Science.gov (United States)

    Schreiber, N. J.; Zhang, Junjie; Zheng, Hong; Freeland, J. W.; Chen, Yu-Sheng; Mitchell, J. F.; Phelan, D.

    2017-10-01

    Praseodymium-containing cobalt perovskites, such as (Pr1-yYy)1-xCaxCoO3-δ, have been argued to undergo a first-order charge shift between Pr and hybridized Co-O orbitals that leads to a metal-insulator transition at a temperature, TVT. Magnetization and x-ray absorption spectroscopy measurements on single crystals of (Pr0.85Y0.15)0.7Ca0.3CoO3-δ grown in an IR image furnace under 40-60 bar of oxygen confirm the presence of this valence transition. Single crystal x-ray synchrotron diffraction measurements are consistent with an isomorphic phase transition at TVT. No evidence of charge ordering was revealed by the single crystal diffraction. Dissimilar to analytical transmission electron microscopy measurements performed on a grain from a polycrystalline sample that revealed an oxygen vacancy order-disorder transition at TVT, the present single-crystal measurements did not evidence such a transition, likely reflecting a lower density of oxygen vacancies in the high-pO2 grown single crystals.

  1. Precision measurement of single atoms strongly coupled to the higher-order transverse modes of a high-finesse optical cavity

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jinjin; Li, Wenfang; Wen, Ruijuan; Li, Gang; Zhang, Pengfei; Zhang, Tiancai [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China)

    2013-08-19

    We have experimentally demonstrated the strong coupling between single atoms and the higher-order Hermite-Gaussian transverse modes in a high-finesse optical microcavity. Compared to the usual low-order symmetric transverse modes, multiple lobes and the asymmetric spatial pattern of the titled modes provide more information about the motion of single atoms in the cavity. The motional information can be extracted from the measured transmission spectra, which includes the velocities and the positions of the atoms in vertical and off-axis directions. The scheme has great potential in time-resolved atom-cavity microscopy and in tracking the three-dimensional single atom trajectory in real time.

  2. Second-order Born effects in the coplanar to perpendicular plane single ionization of Xe (5p)

    International Nuclear Information System (INIS)

    Singh, Prithvi; Purohit, G; Patidar, Vinod

    2013-01-01

    Differential cross section results for the coplanar to perpendicular plane ionization of xenon atoms at incident electron energies of 40 and 20 eV above ionization potential are reported. The cross sections have been calculated in the modified distorted wave Born approximation (DWBA) formalism including the second-order Born amplitude. Our present attempt verifies the role of second-order processes in the ionization of xenon atoms at low and intermediate energy ranges. We compare the (e, 2e) triple differential cross section results of our calculation with the very recent measurements of Nixon and Murray (2012 Phys. Rev. A 85 022716) and relativistic DWBA-G results of Illarionov and Stauffer (2012 J. Phys. B: At. Mol. Opt. Phys. 45 225202). Overall agreement with measurements has been improved by inclusion of a second-order term in the description of the collision process. (paper)

  3. Comparison of sequential and single extraction in order to estimate environmental impact of metals from fly ash

    Directory of Open Access Journals (Sweden)

    Tasić Aleksandra M.

    2016-01-01

    Full Text Available The aim of this paper was to simulate leaching of metals from fly ash in different environmental conditions using ultrasound and microwave-assisted extraction techniques. Single-agent extraction and sequential extraction procedures were used to determine the levels of different metals leaching. The concentration of metals (Al, Fe, Mn, Cd, Co, Cr, Ni, Pb, Cu, As, Be in fly ash extracts were measured by Inductively Coupled Plasma-Atomic Emission Spectrometry. Single-agent extractions of metals were conducted during sonication times of 10, 20, 30, 40 and 50 min. Single-agent extraction with deionized water was also undertaken by exposing samples to microwave radiation at the temperature of 50°C. The sequential extraction was undertaken according to the BCR procedure which was modified and applied to study the partitioning of metals in coal fly ash. The microwave-assisted sequential extraction was performed at different extraction temperatures: 50, 100 and 150°C. The partitioning of metals between the individual fractions was investigated and discussed. The efficiency of the extraction process for each step was examined. In addition, the results of the microwave-assisted sequential extraction are compared to the results obtained by standard ASTM method. The mobility of most elements contained in fly ash is markedly pH sensitive. [Projekat Ministarstva nauke Republike Srbije, br. 172030, br. 176006 i br. III43009

  4. 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 .

  5. 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

  6. 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.

  7. 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.

  8. Parameter optimization for Ti-47Al-2Cr-2Nb in selective laser melting based on geometric characteristics of single scan tracks

    Science.gov (United States)

    Shi, Xuezhi; Ma, Shuyuan; Liu, Changmeng; Wu, Qianru

    2017-05-01

    A rapid method for parameter optimization for Ti-47Al-2Cr-2Nb powder in selective laser melting (SLM) based on melt pool characterizations is developed. The laser power and scanning speed are selected through the surface morphologies of single tracks to fabricate the high-density samples. The influences of the parameters on sectional geometric characteristics (width, height, depth, bulge area, penetration area and dilution) are analyzed by linear regression analysis, and the regression models are established to predict the geometric characteristics of single tracks. An inappropriate combination of process parameters can cause material evaporation and the melt pool instability, leading to generation of cracking and balling, which will reduce the linear correlation. The loss of Al is also an important reference criterion for the optimization of the process parameters, so Al content measurements are conducted to validate evaporation during the SLM processing. The Al loss from single tracks varies from 5.73 to 0.32 at%. Applying optimal process parameters to the fabrication of TiAl parts result in densities ranging from 97.34% to 98.95%. However, more serious losses and an uneven distribution of Al in the fabricated samples are observed.

  9. Monitoring the functionalization of single-walled carbon nanotubes with chitosan and folic acid by two-dimensional diffusion-ordered nmr spectroscopy

    DEFF Research Database (Denmark)

    Castillo, John J.; Torres, Mary H.; Molina, Daniel R.

    2012-01-01

    A conjugate between single-walled carbon nanotubes, chitosan and folic acid has been prepared. It was characterized by diffusion ordered two-dimensional hydrogen-1 nuclear magnetic resonance and hydrogen-1 nuclear magnetic resonance spectroscopy which revealed the presence of a conjugate that was......A conjugate between single-walled carbon nanotubes, chitosan and folic acid has been prepared. It was characterized by diffusion ordered two-dimensional hydrogen-1 nuclear magnetic resonance and hydrogen-1 nuclear magnetic resonance spectroscopy which revealed the presence of a conjugate...... that was generated by the linkage between the carboxyl moiety of the folic acid and the amino group of the chitosan, which in turn was non-covalently bound to the single-walled carbon nanotubes. The obtained diffusion coefficient values demonstrated that free folic acid diffused more rapidly than the folic acid...... conjugated to single-walled carbon nanotubes-chitosan. The values of the proton signal of hydrogen-1 nuclear magnetic resonance spectroscopy and two-dimensional hydrogen-1 nuclear magnetic resonance spectroscopy further confirmed that the folic acid was conjugated to the chitosan, wrapping the single...

  10. The HST/ACS Coma Cluster Survey : III. Structural parameters of galaxies using single Sersic fits star

    NARCIS (Netherlands)

    Hoyos, Carlos; den Brok, Mark; Verdoes Kleijn, Gijs; Carter, David; Balcells, Marc; Guzmán, Rafael; Peletier, Reynier; Ferguson, Henry C.; Goudfrooij, Paul; Graham, Alister W.; Hammer, Derek; Karick, Arna M.; Lucey, John R.; Matković, Ana; Merritt, David; Mouhcine, Mustapha; Valentijn, Edwin

    We present a catalogue of structural parameters for 8814 galaxies in the 25 fields of the Hubble Space Telescope/ACS Coma Treasury Survey. Parameters from Sersic fits to the two-dimensional surface brightness distributions are given for all galaxies from our published Coma photometric catalogue with

  11. Lifetimes of organic photovoltaics: Design and synthesis of single oligomer molecules in order to study chemical degradation mechanisms

    DEFF Research Database (Denmark)

    Alstrup, J.; Norrman, K.; Jørgensen, M.

    2006-01-01

    Degradation mechanisms in organic and polymer photovoltaics are addressed through the study of an organic photovoltaic molecule based on a single phenylene-vinylene-type oligomer molecule. The synthesis of such a model compound with different end-groups is presented that allows for assignment...... of degradation products from different parts of the molecule. Photovoltaic devices with and without C(60) have been prepared and their characteristics under AM1.5 conditions are reported. The degradation of the active phenylene-vinylene compound in darkness and after 20h of illumination were investigated using...

  12. A Low-Order Harmonic Elimination Scheme for Induction Motor Drives Using a Multilevel Octadecagonal Space Vector Structure With a Single DC Source

    DEFF Research Database (Denmark)

    Boby, Mathews; Rahul, Arun; Gopakumar, K.

    2018-01-01

    Conventional voltage-source inverters used for induction motor drives generate a hexagonal space vector structure. In the overmodulation range, the hexagonal space vector structure generates low-order harmonics in the phase voltage resulting in low-order torque ripple in the motor. Inverter...... topologies with an octadecagonal (18 sided) space vector structure eliminate fifth-, seventh-, eleventh-, and thirteenth-order harmonics from the phase voltage, and hence, the dominant sixth- and twelfth-order torque ripple generation is eliminated. Octadecagonal space vector structures proposed in the past...... require multiple dc sources, which makes four-quadrant operation of the drive system difficult and costly. In this paper, the formation of a multilevel nine-concentric octadecagonal space vector structure using a single dc source is proposed. Detailed experimental results, using open-loop V/f control...

  13. 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

  14. Ordered Assembly and Controlled Electron Transfer of the Blue Copper Protein Azurin at Gold (111) Single-Crystal Substrates

    DEFF Research Database (Denmark)

    Chi, Qijin; Zhang, Jingdong; Andersen, Jens Enevold Thaulov

    2001-01-01

    or monolayers. In this orientation mode azurin molecules on Au(111) are oriented with the redox center (copper atom) facing the electrode surface. This is opposite to the orientation of azurin on bare gold which is via a surface disulfide group such as recently reported. Scanning tunneling microscopy (STM......) with molecular resolution reveals that both well-ordered alkanethiol and protein adlayers are present. Adsorbed azurin molecules exhibit high stability and retain electron transfer (ET) function. Long-range interfacial ET between azurin and Au(111) across variable-length alkanethiol bridges was systematically...

  15. Extraction of contact resistance and channel parameters from the electrical characteristics of a single bottom-gate/top-contact organic transistor

    Science.gov (United States)

    Takagaki, Shunsuke; Yamada, Hirofumi; Noda, Kei

    2016-03-01

    A parameter extraction procedure for staggered-type organic field-effect transistors (OFETs), in which only the electrical characteristics of a single device are needed, was newly considered. The existing differential method and the transition voltage method for evaluating contact and channel parameters in OFETs were complementarily combined. The calibration of the total resistance between the source and the drain was also incorporated to compensate discrepancies in the total resistances calculated from output and transfer characteristics, caused by the existence of nonignorable contact resistance and carrier traps. By using our proposed method, gate-voltage-dependent contact resistance and channel mobility in the linear regime were evaluated for bottom-gate/top-contact pentacene thin-film transistors, and the channel-length dependence of these parameters was investigated. A series of results of parameter extraction confirm the validity of our proposed method, which is advantageous in avoiding the influences of characteristic variations that are frequently observed in practical OFET devices.

  16. Single Tracking Location Acoustic Radiation Force Impulse Viscoelasticity Estimation (STL-VE): A Method for Measuring Tissue Viscoelastic Parameters

    OpenAIRE

    Langdon, Jonathan H; Elegbe, Etana; McAleavey, Stephen A

    2015-01-01

    Single Tracking Location (STL) Shear wave Elasticity Imaging (SWEI) is a method for detecting elastic differences between tissues. It has the advantage of intrinsic speckle bias suppression compared to Multiple Tracking Location (MTL) variants of SWEI. However, the assumption of a linear model leads to an overestimation of the shear modulus in viscoelastic media. A new reconstruction technique denoted Single Tracking Location Viscosity Estimation (STL-VE) is introduced to correct for this ove...

  17. Simultaneous estimation of population receptive field and hemodynamic parameters from single point BOLD responses using Metropolis-Hastings sampling.

    Science.gov (United States)

    Adaszewski, Stanisław; Slater, David; Melie-Garcia, Lester; Draganski, Bogdan; Bogorodzki, Piotr

    2018-01-30

    We introduce a new approach to Bayesian pRF model estimation using Markov Chain Monte Carlo (MCMC) sampling for simultaneous estimation of pRF and hemodynamic parameters. To obtain high performance on commonly accessible hardware we present a novel heuristic consisting of interpolation between precomputed responses for predetermined stimuli and a large cross-section of receptive field parameters. We investigate the validity of the proposed approach with respect to MCMC convergence, tuning and biases. We compare different combinations of pRF - Compressive Spatial Summation (CSS), Dumoulin-Wandell (DW) and hemodynamic (5-parameter and 3-parameter Balloon-Windkessel) models within our framework with and without the usage of the new heuristic. We evaluate estimation consistency and log probability across models. We perform as well a comparison of one model with and without lookup table within the RStan framework using its No-U-Turn Sampler. We present accelerated computation of whole-ROI parameters for one subject. Finally, we discuss risks and limitations associated with the usage of the new heuristic as well as the means of resolving them. We found that the new algorithm is a valid sampling approach to joint pRF/hemodynamic parameter estimation and that it exhibits very high performance. Copyright © 2018. Published by Elsevier Inc.

  18. A high-throughput 2D-analytical technique to obtain single protein parameters from complex cell lysates for in silico process development of ion exchange chromatography.

    Science.gov (United States)

    Kröner, Frieder; Elsäßer, Dennis; Hubbuch, Jürgen

    2013-11-29

    The accelerating growth of the market for biopharmaceutical proteins, the market entry of biosimilars and the growing interest in new, more complex molecules constantly pose new challenges for bioseparation process development. In the presented work we demonstrate the application of a multidimensional, analytical separation approach to obtain the relevant physicochemical parameters of single proteins in a complex mixture for in silico chromatographic process development. A complete cell lysate containing a low titre target protein was first fractionated by multiple linear salt gradient anion exchange chromatography (AEC) with varying gradient length. The collected fractions were subsequently analysed by high-throughput capillary gel electrophoresis (HT-CGE) after being desalted and concentrated. From the obtained data of the 2D-separation the retention-volumes and the concentration of the single proteins were determined. The retention-volumes of the single proteins were used to calculate the related steric-mass action model parameters. In a final evaluation experiment the received parameters were successfully applied to predict the retention behaviour of the single proteins in salt gradient AEC. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. A new PLL system using full order observer and PLL system modeling in a single phase grid-connected inverter

    DEFF Research Database (Denmark)

    Ko, Youngjong; Park, Kiwoo; Lee, Kyo-Beum

    2011-01-01

    In a grid connected power conversion system, the phase angle information of a grid voltage is very essential for supplying power to the grid since it is used for active and reactive power control. A Phase Locked Loop (PLL) system is used and should be robust because often the actual grid voltages...... into fundamental and harmonic components and a virtual phase voltage is generated from the fundamental component using a Full Order Observer (FOO). Two virtual voltages are used as an input for the PLL system so the phase angle errors can be reduced and the output power quality can be improved. The dynamic...... are usually distorted by unexpected harmonics. However, conventional PLL systems have steady state errors when distorted voltages are used as a PLL input. Furthermore, using this distorted phase angle in the power control could reduce the output power quality. In this paper, the grid voltages are separated...

  20. Ordered misfit dislocations in epitaxial Gd doped CeO2 thin films deposited on (001)YSZ single crystal substrates

    Science.gov (United States)

    Petrișor, T.; Meledin, A.; Boulle, A.; Moș, R. B.; Gabor, M. S.; Ciontea, L.; Petrișor, T.

    2018-03-01

    Misfit dislocations are ubiquitous in thin film systems, and their presence can profoundly affect the chemical and physical properties of materials. In the present paper, we investigate the misfit dislocation array present at the interface of a Gd doped CeO2 thin film epitaxially grown on a (001) yttria stabilized zirconia (YSZ) single crystal substrate. Because of the large misfit strain (-4.9%), the growth takes place by domain-matching epitaxy with the formation of geometrical misfit dislocations. Transmission electron microscopy (TEM) observations, combined with geometrical phase analysis and strain field calculations (in the case of elastic isotropy), reveal that the misfit dislocations are of purely edge type with Burgers vector b = ½[110] and with the dislocations lines parallel to the [1-10] direction. X-ray diffraction, combined with Monte Carlo simulations, allow to quantify the statistical properties of the dislocations ensemble. It is found that the dislocations are distributed according to a Gamma distribution with a mean dislocation spacing of 7.4 nm and with a spacing ranging from 3.5 to 12 nm, in excellent agreement with TEM observations and with the values expected from the relaxation of the misfit strain.

  1. Minimization of lattice parameter change in Czochralski grown (Gd sub 1-x Y sub x ) sub 3 Ga sub 5 O sub 12 garnet single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Hideo; Numazawa, Takenori; Sato, Mitsunori; Maeda, Hiroshi (National Research Inst. for Metals, Ibaraki (Japan)); Sakamoto, Masaru (Nippon Mining Co. Ltd., Saitama (Japan))

    1992-05-01

    Single crystals of (Gd{sub 1-x}Y{sub x}){sub 3}Ga{sub 5}O{sub 12} rare-earth garnet solid solutions were grown by using the Czochralski technique and their lattice parameter change along the growth direction was minimized by means of the combination of a solid solution effect and a nonstoichiometry effect for the garnet. The single crystals are promising magnetic refrigerants for magnetic refrigerators to generate a low temperature atmosphere below 1 K. (orig.).

  2. 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.

  3. Analysis of process parameters in surface grinding using single objective Taguchi and multi-objective grey relational grade

    Directory of Open Access Journals (Sweden)

    Prashant J. Patil

    2016-09-01

    Full Text Available Close tolerance and good surface finish are achieved by means of grinding process. This study was carried out for multi-objective optimization of MQL grinding process parameters. Water based Al2O3 and CuO nanofluids of various concentrations are used as lubricant for MQL system. Grinding experiments were carried out on instrumented surface grinding machine. For experimentation purpose Taguchi's method was used. Important process parameters that affect the G ratio and surface finish in MQL grinding are depth of cut, type of lubricant, feed rate, grinding wheel speed, coolant flow rate, and nanoparticle size. Grinding performance was calculated by the measurement G ratio and surface finish. For improvement of grinding process a multi-objective process parameter optimization is performed by use of Taguchi based grey relational analysis. To identify most significant factor of process analysis of variance (ANOVA has been used.

  4. Effective material parameter retrieval for thin sheets: Theory and application to graphene, thin silver films, and single-layer metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Tassin, Philippe, E-mail: tassin@ameslab.gov [Ames Laboratory - U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Koschny, Thomas, E-mail: koschny@ameslab.gov [Ames Laboratory - U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Soukoulis, Costas M., E-mail: soukoulis@ameslab.gov [Ames Laboratory - U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Institute of Electronic Structure and Lasers (IESL), FORTH, 71110 Heraklion, Crete (Greece)

    2012-10-15

    An important tool in the field of metamaterials is the extraction of effective material parameters from simulated or measured scattering parameters of a sample. Here we discuss a retrieval method for thin-film structures that can be approximated by a two-dimensional scattering sheet. We determine the effective sheet conductivity from the scattering parameters and we point out the importance of the magnetic sheet current to avoid an overdetermined inversion problem. Subsequently, we present two applications of the sheet retrieval method. First, we determine the effective sheet conductivity of thin silver films and we compare the resulting conductivities with the sheet conductivity of graphene. Second, we apply the method to a cut-wire metamaterial with an electric dipole resonance. The method is valid for thin-film structures such as two-dimensional metamaterials and frequency-selective surfaces and can be easily generalized for anisotropic or chiral media.

  5. Six switches solution for single-phase AC/DC/AC converter with capability of second-order power mitigation in DC-link capacitor

    DEFF Research Database (Denmark)

    Liu, Xiong; Wang, Peng; Loh, Poh Chiang

    2011-01-01

    This paper proposes an approach for DC-link second-order harmonic power cancellation in single-phase AC/DC/AC converter with reduced number of switches. The proposed six-switch converter has two bridges with three switches in each of them, where the middle switch in each bridge is shared by the AC....../DC rectifier and DC/AC inverter. A small size DC-link capacitor can be achieved through coordination control of rectifier and inverter to cancel the second-order oscillation power. Maximum available phase difference between rectifier’s and inverter’s modulation references is investigated to be dependent...... on their modulation indices of the six-switch converter, and high modulation indices are proved to be feasible for second-order power cancellation in the DC-link based on the phase difference analysis. Both reduced switch numbers and DC electrolytic capacitor size can be achieved using the proposed converter...

  6. 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

  7. 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.

  8. Neural network-based preprocessing to estimate the parameters of the X-ray emission of a single-temperature thermal plasma

    Science.gov (United States)

    Ichinohe, Y.; Yamada, S.; Miyazaki, N.; Saito, S.

    2018-04-01

    We present data preprocessing based on an artificial neural network to estimate the parameters of the X-ray emission spectra of a single-temperature thermal plasma. The method finds appropriate parameters close to the global optimum. The neural network is designed to learn the parameters of the thermal plasma (temperature, abundance, normalization and redshift) of the input spectra. After training using 9000 simulated X-ray spectra, the network has grown to predict all the unknown parameters with uncertainties of about a few per cent. The performance dependence on the network structure has been studied. We applied the neural network to an actual high-resolution spectrum obtained with Hitomi. The predicted plasma parameters agree with the known best-fitting parameters of the Perseus cluster within uncertainties of ≲10 per cent. The result shows that neural networks trained by simulated data might possibly be used to extract a feature built in the data. This would reduce human-intensive preprocessing costs before detailed spectral analysis, and would help us make the best use of the large quantities of spectral data that will be available in the coming decades.

  9. The conditional power of randomization tests for single-case effect sizes in designs with randomized treatment order: A Monte Carlo simulation study.

    Science.gov (United States)

    Michiels, Bart; Heyvaert, Mieke; Onghena, Patrick

    2017-04-07

    The conditional power (CP) of the randomization test (RT) was investigated in a simulation study in which three different single-case effect size (ES) measures were used as the test statistics: the mean difference (MD), the percentage of nonoverlapping data (PND), and the nonoverlap of all pairs (NAP). Furthermore, we studied the effect of the experimental design on the RT's CP for three different single-case designs with rapid treatment alternation: the completely randomized design (CRD), the randomized block design (RBD), and the restricted randomized alternation design (RRAD). As a third goal, we evaluated the CP of the RT for three types of simulated data: data generated from a standard normal distribution, data generated from a uniform distribution, and data generated from a first-order autoregressive Gaussian process. The results showed that the MD and NAP perform very similarly in terms of CP, whereas the PND performs substantially worse. Furthermore, the RRAD yielded marginally higher power in the RT, followed by the CRD and then the RBD. Finally, the power of the RT was almost unaffected by the type of the simulated data. On the basis of the results of the simulation study, we recommend at least 20 measurement occasions for single-case designs with a randomized treatment order that are to be evaluated with an RT using a 5% significance level. Furthermore, we do not recommend use of the PND, because of its low power in the RT.

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

    Directory of Open Access Journals (Sweden)

    Haishan Deng

    2014-01-01

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

  11. Low temperature time resolved photoluminescence in ordered and disordered Cu{sub 2}ZnSnS{sub 4} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Raadik, Taavi, E-mail: taavi.raadik@ttu.ee [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Krustok, Jüri; Kauk-Kuusik, M.; Timmo, K.; Grossberg, M. [Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Ernits, K. [crystalsol OÜ, Akadeemia tee 15a, 12618 Tallinn (Estonia); Bleuse, J. [CEA-CNRS-UGA group “Nanophysique et Semiconducteurs”, Univ. Grenoble Alpes, INAC-PHELIQS, CEA, INAC-PHELIQS, CNRS, PLUM, F-38000 Grenoble (France)

    2017-03-01

    In this work we performed time-resolved micro-photoluminescence (TRPL) studies of Cu{sub 2}ZnSnS{sub 4} (CZTS) single crystals grown in molten KI salt. The order/disorder degree of CZTS was varied by the thermal post treatment temperature. Photoluminescence spectra measured at T=8 K showed an asymmetric band with a peak position of 1.33 eV and 1.27 eV for partially ordered and disordered structures, respectively. Thermal activation energies were found to be E{sub T} {sub (PO)} =65±9 meV for partially ordered and E{sub T(PD)} =27±4 meV for partially disordered. These low activation energy values indicating to the defect cluster recombination model for both partially ordered and disordered structures. TRPL was measured for both crystals and their decay curves were fitted with a stretched exponential function, in order to describe the charge carriers’ recombination dynamics at low temperature.

  12. Optical parameters and dispersion behavior of potassium magnesium chloride sulfate single crystals doped with Co+2 ions.

    Science.gov (United States)

    Abu El-Fadl, A; Abd-Elsalam, A M

    2018-05-05

    Single crystals of potassium magnesium chloride sulfate (KMCS) doped with cobalt ions were grown by slow cooling method. Powder XRD study confirmed the monoclinic structure of the grown crystals. The functional group vibrations were checked through FTIR spectroscopy measurements. In optical studies, the absorbance behavior of the crystals and their optical energy gap were established by Tauc plot. The refractive index, the extinction coefficient and other optical constants were calculated for the grown crystals. The normal dispersion of the refractive index was analyzed according to single oscillator Sellmeier's model. The Urbach's rule was applied to analyze the localized states density in the forbidden gap. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. 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

  14. Primordial non-Gaussianities of gravitational waves in the most general single-field inflation model with second-order field equations.

    Science.gov (United States)

    Gao, Xian; Kobayashi, Tsutomu; Yamaguchi, Masahide; Yokoyama, Jun'ichi

    2011-11-18

    We completely clarify the feature of primordial non-Gaussianities of tensor perturbations in the most general single-field inflation model with second-order field equations. It is shown that the most general cubic action for the tensor perturbation h(ij) is composed only of two contributions, one with two spacial derivatives and the other with one time derivative on each h(ij). The former is essentially identical to the cubic term that appears in Einstein gravity and predicts a squeezed shape, while the latter newly appears in the presence of the kinetic coupling to the Einstein tensor and predicts an equilateral shape. Thus, only two shapes appear in the graviton bispectrum of the most general single-field inflation model, which could open a new clue to the identification of inflationary gravitational waves in observations of cosmic microwave background anisotropies as well as direct detection experiments.

  15. Benchmark of AC and DC active power decoupling circuits for second-order harmonic mitigation in kW-scale single-phase inverters

    DEFF Research Database (Denmark)

    Qin, Zian; Tang, Yi; Loh, Poh Chiang

    2015-01-01

    studied, where the commercially available film capacitors, circuit topologies, and control strategies for active power decoupling are all taken into account. Then, an adaptive decoupling voltage control method is proposed to further improve the performance of dc decoupling in terms of efficiency...... and reliability. The feasibility and superiority of the identified solution for active power decoupling together with the proposed adaptive decoupling voltage control method are finally verified by both the experimental results obtained on a 2 kW single-phase inverter.......This paper presents the benchmark study of ac and dc active power decoupling circuits for second-order harmonic mitigation in kW-scale single-phase inverters. First of all, the best solutions of active power decoupling to achieve high efficiency and power density are identified and comprehensively...

  16. Studies on 2-amino-5-nitropyridinium nitrate (2A5NPN): A semi-organic third order nonlinear optical single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Sivasubramani, V.; Pandian, Muthu Senthil, E-mail: senthilpandianm@ssn.edu.in; Ramasamy, P. [SSN Research Centre, SSN College of Engineering, Kalavakkam-603 110, Chennai, Tamilnadu (India)

    2016-05-23

    2-amino-5-nitropyridinium nitrate (2A5NPN) is a semi-organic nonlinear optical crystal and optically good quality 2A5NPN single crystals were successfully grown by slow evaporation solution growth technique (SEST) at ambient temperature. The crystallographic structure of the grown crystal was determined by single crystal X-Ray diffraction analysis and it belongs to Monoclinic crystal system with centro symmetric crystalline nature. The crystallinity of the grown crystal was confirmed by powder X-ray diffraction analysis. The other physical properties of grown crystals are also characterized using TG-DTA, UV-Visible NIR, chemical etching, photoconductivity and Z-scan measurements. The Z-scan method reveals that the 2A5NPN crystal possesses multi photon absorption behaviour and the significantly higher third order susceptibility and it is a promising potential NLO material.

  17. 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.

  18. Micro-positron emission tomography for measuring sub-core scale single and multiphase transport parameters in porous media

    Science.gov (United States)

    Zahasky, Christopher; Benson, Sally M.

    2018-05-01

    Accurate descriptions of heterogeneity in porous media are important for understanding and modeling single phase (e.g. contaminant transport, saltwater intrusion) and multiphase (e.g. geologic carbon storage, enhanced oil recovery) transport problems. Application of medical imaging to experimentally quantify these processes has led to significant progress in material characterization and understanding fluid transport behavior at laboratory scales. While widely utilized in cancer diagnosis and management, cardiology, and neurology, positron emission tomography (PET) has had relatively limited applications in earth science. This study utilizes a small-bore micro-PET scanner to image and quantify the transport behavior of pulses of a conservative aqueous radiotracer injected during single and multiphase flow experiments in two heterogeneous Berea sandstone cores. The cores are discretized into axial-parallel streamtubes, and using the reconstructed micro-PET data, expressions are derived from spatial moment analysis for calculating sub-core tracer flux and pore water velocity. Using the flux and velocity measurements, it is possible to calculate porosity and saturation from volumetric flux balance, and calculate permeability and water relative permeability from Darcy's law. Second spatial moment analysis enables measurement of sub-core solute dispersion during both single phase and multiphase experiments. A numerical simulation model is developed to verify the assumptions of the streamtube dimension reduction technique. A variation of the reactor ratio is presented as a diagnostic metric to efficiently determine the validity of the streamtube approximation in core and column-scale experiments. This study introduces a new method to quantify sub-core permeability, relative permeability, and dispersion. These experimental and analytical methods provide a foundation for future work on experimental measurements of differences in transport behavior across scales.

  19. Pressure and field induced magnetic order in the spin liquid Tb2Ti2O7 as studied by single crystal neutron diffraction.

    Science.gov (United States)

    Mirebeau, I; Goncharenko, I N; Dhalenne, G; Revcolevschi, A

    2004-10-29

    We have studied the spin liquid Tb2Ti2O7 by single crystal neutron diffraction under high pressure up to 2.8 GPa, together with uniaxial stress, down to 0.1 K, in zero and high magnetic fields up to 7 T. In zero magnetic field, a long-range ordered antiferromagnetic structure is induced by pressure. The Néel temperature and ordered magnetic moment can be tuned by the anisotropic pressure component. Under magnetic field, the antiferromagnetic structure transforms into a canted ferromagnetic one at 0.6 T. Spin canting persists even at 7 T. The magnetic phase diagram under pressure shows a strong increase of the Néel temperature with the field.

  20. Pressure and field induced magnetic order in the spin liquid Tb2Ti2O7 as studied by single crystal neutron diffraction

    International Nuclear Information System (INIS)

    Mirebeau, I.; Goncharenko, I. N.; Dhalenne, G.; Revcolevschi, A.

    2004-01-01

    We have studied the spin liquid Tb 2 Ti 2 O 7 by single crystal neutron diffraction under high pressure up to 2.8 GPa, together with uniaxial stress, down to 0.1 K, in zero and high magnetic fields up to 7 T. In zero magnetic field, a long-range ordered antiferromagnetic structure is induced by pressure. The Neel temperature and ordered magnetic moment can be tuned by the anisotropic pressure component. Under magnetic field, the antiferromagnetic structure transforms into a canted ferromagnetic one at 0.6 T. Spin canting persists even at 7 T. The magnetic phase diagram under pressure shows a strong increase of the Neel temperature with the field

  1. A numerical study on the effect of various combustion bowl parameters on the performance, combustion, and emission behavior on a single cylinder diesel engine.

    Science.gov (United States)

    Balasubramanian, Dhinesh; Sokkalingam Arumugam, Sabari Rajan; Subramani, Lingesan; Joshua Stephen Chellakumar, Isaac JoshuaRamesh Lalvani; Mani, Annamalai

    2018-01-01

    A numerical study was carried out to study the effect of various combustion bowl parameters on the performance behavior, combustion characteristics, and emission magnitude on a single cylinder diesel engine. A base combustion bowl and 11 different combustion bowls were created by varying the aspect ratio, reentrancy ratio, and bore to bowl ratio. The study was carried out at engine rated speed and a full throttle performance condition, without altering the compression ratio. The results revealed that the combustion bowl parameters could have a huge impact on the performance behavior, combustion characteristics, and emission magnitude of the engine. The bowl parameters, namely throat diameter and toroidal radius, played a crucial role in determining the performance behavior of the combustion bowls. It was observed that the combustion bowl parameters, namely central pip distance, throat diameter, and bowl depth, also could have an impact on the combustion characteristics. And throat diameter and toroidal radius, central pip distance, and toroidal corner radius could have a consequent effect on the emission magnitude of the engine. Of the different combustion bowls tested, combustion bowl 4 was preferable to others owing to the superior performance of 3% of higher indicated mean effective pressure and lower fuel consumption. Interestingly, trade-off for NO x emission was higher only by 2.85% compared with the base bowl. The sensitivity analysis proved that bowl depth, bowl diameter, toroidal radius, and throat diameter played a vital role in the fuel consumption parameter and emission characteristics even at the manufacturing tolerance variations.

  2. Additive Manufacturing of Single-Crystal Superalloy CMSX-4 Through Scanning Laser Epitaxy: Computational Modeling, Experimental Process Development, and Process Parameter Optimization

    Science.gov (United States)

    Basak, Amrita; Acharya, Ranadip; Das, Suman

    2016-08-01

    This paper focuses on additive manufacturing (AM) of single-crystal (SX) nickel-based superalloy CMSX-4 through scanning laser epitaxy (SLE). SLE, a powder bed fusion-based AM process was explored for the purpose of producing crack-free, dense deposits of CMSX-4 on top of similar chemistry investment-cast substrates. Optical microscopy and scanning electron microscopy (SEM) investigations revealed the presence of dendritic microstructures that consisted of fine γ' precipitates within the γ matrix in the deposit region. Computational fluid dynamics (CFD)-based process modeling, statistical design of experiments (DoE), and microstructural characterization techniques were combined to produce metallurgically bonded single-crystal deposits of more than 500 μm height in a single pass along the entire length of the substrate. A customized quantitative metallography based image analysis technique was employed for automatic extraction of various deposit quality metrics from the digital cross-sectional micrographs. The processing parameters were varied, and optimal processing windows were identified to obtain good quality deposits. The results reported here represent one of the few successes obtained in producing single-crystal epitaxial deposits through a powder bed fusion-based metal AM process and thus demonstrate the potential of SLE to repair and manufacture single-crystal hot section components of gas turbine systems from nickel-based superalloy powders.

  3. Investigations on critical parameters, growth, structural and spectral studies of beta-alaninium picrate (BAP) single crystals

    International Nuclear Information System (INIS)

    Shanthi, D; Selvarajan, P; Perumal, S

    2014-01-01

    Beta-alaninium picrate (BAP) salt has been synthesized and the solubility of the synthesized sample in double distilled water was determined at different temperatures. Solution stability was studied by observing the metastable zone width by employing the polythermal method. Induction period values for different supersaturation ratios at room temperature were determined based on the isothermal method. The nucleation parameters such as critical radius, critical free energy change, interfacial tension, and nucleation rate have been estimated for BAP salt on the basis of the classical nucleation theory. The lattice parameters of the grown BAP crystal were determined using the x-ray diffraction (XRD) technique. The reflection planes of the sample were confirmed by the powder XRD study and diffraction peaks were indexed. Fourier transform infrared spectroscopy and Fourier transform–Raman studies were used to confirm the presence of various functional groups in the BAP crystal. The nonlinear optical property of the grown crystal was studied using the Kurtz–Perry powder technique. UV–visible spectral studies were carried out to understand optical transparency and the type of band gap of the grown BAP crystal. (paper)

  4. Consumption of a single serving of red raspberries per day reduces metabolic syndrome parameters in high-fat fed mice.

    Science.gov (United States)

    Luo, T; Miranda-Garcia, O; Sasaki, G; Shay, N F

    2017-11-15

    Using an animal model for diet-induced metabolic disease, we have shown previously that the addition of raspberry juice concentrate (RJC) and raspberry puree concentrate (RPC) at a level of 10% of kcal, equivalent to four servings per day, to an obesogenic high-fat, western-style diet (HF) significantly reduced body weight gain, serum resistin levels, and altered the expression of hepatic genes related to lipid metabolism and oxidative stress. This study was designed to examine the effect of a lower level of RJC or RPC consumption, at a level representing a single serving of food per day (2.5% of kcal). For ten weeks, four groups of C57BL/6J mice (n = 8 ea.) were fed: low fat (LF), HF, HF + RJC, or HF + RPC diets. Intake of RJC and RPC decreased final body weight. Hepatic lipid accumulation was significantly decreased in HF + RPC- and HF + RJC-fed mice, compared to HF-fed mice. Further, the relative expression of hepatic genes including Heme oxygenase 1 (Hmox1) and Hormone sensitive lipase (Lipe), were altered by RPC or RJC consumption. In this mouse model of diet-induced metabolic disease, consumption of the equivalent of a single daily serving of either RPC or RJC improved metabolism in mice fed HF diet. We hypothesize that the phytochemicals contained in raspberries, and/or their subsequent metabolites, may be acting to influence gene expression and other regulatory pathways, to produce the metabolic improvements observed in this study.

  5. Influences of processing parameters on microstructure during investment casting of nickel-base single crystal superalloy DD3

    Directory of Open Access Journals (Sweden)

    Gao Sifeng

    2012-05-01

    Full Text Available The effects of solidification variables on the as-cast microstructures of nickel-base single crystal superalloy DD3 have been investigated by using the modified Bridgman apparatus. The experiments were performed under a thermal gradient of approximately 45 K·cm-1 and at withdrawal rates ranging from 30 to 200 m·s-1. The experimental results show that the primary and secondary dendritic arm spacings (PDAS and SDAS decrease when the withdrawal rate is increased. Compared with the theoretical models of PDAS, the results are in good agreement with Trivedi’s model. The relationships of PDAS and SDAS with withdrawal rates can be described as l1 = 649.7V -0.24±0.02 and l2 = 281V -0.32±0.03, respectively. In addition, the size of the γ′ phase significantly decreases with increasing withdrawal rate.

  6. Fully automated radiosynthesis of [18F]Fluoromisonidazole with single neutral alumina column purification: optimization of reaction parameters

    International Nuclear Information System (INIS)

    Nandy, S.K.; Rajan, M.G.R.

    2010-01-01

    1-H-1-(3-[ 18 F]fluoro-2-hydroxypropyl)-2-nitroimidazole ([ 18 F]FMISO), is the most used hypoxia-imaging agent in oncology and we have recently reported a fully automated procedure for its synthesis using the Nuclear Interface FDG module and a single neutral alumina column for purification. Using 1-(2'-nitro-1'-imidazolyl)-2-O-tetra-hydropyranyl-3-O- toluenesulfonylpropanediol (NITTP) as the precursor, we have investigated the yield of [ 18 F]FMISO using different reaction times, temperatures, and the amount of precursor. The overall yield was 48.4 ± 1.2% (n = 3), (without decay correction) obtained using 10 mg NITTP with the radio-fluorination carried out at 145 deg C for 3 min followed by acid hydrolysis for 3 min at 125 deg C in a total synthesis time of 32 ± 1 min. Increasing the precursor amount to 25 mg did not improve the overall yield under identical reaction conditions, with the decay uncorrected yield being 46.8 ± 1.6% (n = 3), but rather made the production less economical. It was also observed that the yield increased linearly with the amount of NITTP used, from 2.5 to 10 mg and plateaued from 10 to 25 mg. Radio-fluorination efficiency at four different conditions was also compared. It was also observed by radio thin layer chromatography (radio-TLC) that the duration of radio-fluorination of NITTP, not the radio-fluorination temperature favoured the formation of labeled thermally degraded product, but the single neutral alumina column purification was sufficient enough to obtain [ 18 F]FMISO devoid of any radiochemical as well as cold impurities. (author)

  7. Mixed conduction and anisotropic single oscillator parameters in low dimensional TlInSe{sub 2} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Qasrawi, A.F., E-mail: aqasrawi@atilim.edu.tr [Group of Physics, Faculty of Engineering, Atilim University, 06836 Ankara (Turkey); Department of Physics, Arab-American University, Jenin, West Bank, Palestine (Country Unknown); Gasanly, N.M. [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey)

    2013-08-15

    Due to the importance of the TlInSe{sub 2} crystal as neutron and γ-ray detectors, its electrical and dispersive optical parameters have been investigated. Particularly, the anisotropic current conduction mechanism in the temperature region of 100–350 K and the room temperature anisotropic dispersive optical properties were studied by means of electrical conductivity and optical reflectance, respectively. It has been shown that the mixed conduction is the most dominant transport mechanism in the TlInSe{sub 2} crystals. Particularly, when the electric field is applied perpendicular to the crystal's c-axis, the main dominant current transport mechanism is due to the mixed conduction and the variable range hopping above and below 160 K, respectively. When the electric field is applied parallel to the crystal's c-axis, the electrical conductivity is dominated by the thermionic emission, mixed conduction and variable range hopping at high, moderate and low temperatures, respectively. The optical reflectivity analysis in the wavelength range 210–1500 nm revealed a clear anisotropy effect on the dispersive optical parameters. Particularly, the static refractive index, static dielectric constant, dispersion energy and oscillator energy exhibited values of 2.50, 6.24, 20.72 eV and 3.96 eV, and values of 3.05, 9.33, 39.27 eV and 4.72 eV for light propagation parallel and perpendicular to the crystal's c-axis, respectively. Moreover, the frequency dependence of the dielectric constant, ε(ω), reflected strong dielectric anisotropy that exhibit maximum ε(ω) value of 38.80 and 11.40 at frequencies of 11.07 × 10{sup 14} Hz for light propagation parallel and perpendicular to the crystal's c-axis, respectively. The anisotropy in the ε(ω) makes the TlInSe{sub 2} crystals attractive to be used as nonvolatile static memory devices. - Graphical abstract: Display Omitted - Highlights: • The anisotropic transport mechanism in low dimensional TlInSe{sub 2

  8. Evaluation of J and CTOD (Crack Tip Opening Displacement) fracture parameters for pipeline steels using Single Edge Notch Tension SE(T) specimens

    Energy Technology Data Exchange (ETDEWEB)

    Paredes Tobar, Lenin Marcelo; Ruggieri, Claudio [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Naval e Oceanica

    2009-12-19

    This work presents an evaluation procedure to determine the elastic-plastic J-integral and CTOD for pin-loaded and clamped single edge notch tension (SE(T)) specimens based upon the eta-method. The primary objective is to derive estimation equations applicable to determine J and CTOD fracture parameters for a wide range of a/W-ratios and material flow properties. Very detailed non-linear finite element analyses for plane-strain and full-thickness, 3-D models provide the evolution of load with increased crack mouth opening displacement which is required for the estimation procedure. The present analyses, when taken together with previous studies provide a fairly extensive body of results which serve to determine parameters J and CTOD for different materials using tension specimens with varying geometries. (author)

  9. The Parkinsonian Gait Spatiotemporal Parameters Quantified by a Single Inertial Sensor before and after Automated Mechanical Peripheral Stimulation Treatment

    Directory of Open Access Journals (Sweden)

    Ana Kleiner

    2015-01-01

    Full Text Available This study aims to evaluate the change in gait spatiotemporal parameters in subjects with Parkinson’s disease (PD before and after Automated Mechanical Peripheral Stimulation (AMPS treatment. Thirty-five subjects with PD and 35 healthy age-matched subjects took part in this study. A dedicated medical device (Gondola was used to administer the AMPS. All patients with PD were treated in off levodopa phase and their gait performances were evaluated by an inertial measurement system before and after the intervention. The one-way ANOVA for repeated measures was performed to assess the differences between pre- and post-AMPS and the one-way ANOVA to assess the differences between PD patients and the control group. Spearman’s correlations assessed the associations between patients with PD clinical status (H&Y and the percentage of improvement of the gait variables after AMPS (α<0.05 for all tests. The PD group had an improvement of 14.85% in the stride length; 14.77% in the gait velocity; and 29.91% in the gait propulsion. The correlation results showed that the higher the H&Y classification, the higher the stride length percentage of improvement. The treatment based on AMPS intervention seems to induce a better performance in the gait pattern of PD patients, mainly in intermediate and advanced stages of the condition.

  10. Improvement of recovery parameters using patient-controlled epidural analgesia after oncological surgery. A prospective, randomized single center study*

    Science.gov (United States)

    Zgâia, Armeana Olimpia; Lisencu, Cosmin Ioan; Rogobete, Alexandru; Vlad, Cătălin; Achimaş-Cadariu, Patriciu; Lazăr, Gabriel; Muntean, Maximilian; Ignat, Florin; Ormindean, Vlad; Irimie, Alexandru

    2017-01-01

    Purpose: The aim of this study was to compare patient-controlled epidural analgesia (PCEA) versus conventional opioid intravenous (IV) infusion after gastrointestinal cancer surgery regarding several post-surgery parameters of recovery. Methods: One hundred and one patients were prospectively randomized to receive either thoracic/lumbar PCEA (PCEA group) or the standard analgesia technique used in our hospital, conventional IV infusion of morphine (IVMO group) after gastrointestinal cancer surgery. Pain intensity, time of mobilization and bowel function recovery were analyzed post-surgery. We also evaluated postoperative complications and length of Postoperative-Intermediate Intensive Care Unit (PI-ICU) stay and hospital stay. Results: Pain intensity was significantly less in the PCEA group in comparison with the IVMO Group at awakening 2, 8, 24, 30 and 48 hours after surgery (p apparition of first stool were significantly faster (1.74 versus 2.26 days, 3.06 versus 3.78 days, 2.1 versus 3.14 days and 3.73 versus 5.28 days, respectively) in the PCEA group than in the IVMO group (p pain control, improves postoperative recovery after gastrointestinal cancer surgery compared with conventional intravenous morphine infusion. Therefore, it is more acceptable than conventional pain management. PMID:28913495

  11. Improvement of recovery parameters using patient-controlled epidural analgesia after oncological surgery. A prospective, randomized single center study.

    Science.gov (United States)

    Zgâia, Armeana Olimpia; Lisencu, Cosmin Ioan; Rogobete, Alexandru; Vlad, Cătălin; Achimaş-Cadariu, Patriciu; Lazăr, Gabriel; Muntean, Maximilian; Ignat, Florin; Ormindean, Vlad; Irimie, Alexandru

    2017-04-01

    The aim of this study was to compare patient-controlled epidural analgesia (PCEA) versus conventional opioid intravenous (IV) infusion after gastrointestinal cancer surgery regarding several post-surgery parameters of recovery. One hundred and one patients were prospectively randomized to receive either thoracic/lumbar PCEA (PCEA group) or the standard analgesia technique used in our hospital, conventional IV infusion of morphine (IVMO group) after gastrointestinal cancer surgery. Pain intensity, time of mobilization and bowel function recovery were analyzed post-surgery. We also evaluated postoperative complications and length of Postoperative-Intermediate Intensive Care Unit (PI-ICU) stay and hospital stay. Pain intensity was significantly less in the PCEA group in comparison with the IVMO Group at awakening 2, 8, 24, 30 and 48 hours after surgery (p apparition of first stool were significantly faster (1.74 versus 2.26 days, 3.06 versus 3.78 days, 2.1 versus 3.14 days and 3.73 versus 5.28 days, respectively) in the PCEA group than in the IVMO group (p pain control, improves postoperative recovery after gastrointestinal cancer surgery compared with conventional intravenous morphine infusion. Therefore, it is more acceptable than conventional pain management.

  12. Control of a White Organic Light Emitting Diode emission parameters using a single doped RGB active layer

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, D. [Departamento de Ciência dos Materiais e i3N – Instituto de Nanoestruturas, Nanomodelação e Nanofabricação, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica (Portugal); Pinto, A.; Califórnia, A.; Gomes, J. [CeNTI – Centro de Nanotecnologia, Materiais Técnicos, Funcionais e Inteligentes, Rua Fernando Mesquita 2785, 4760-034 Vila Nova de Famalicão (Portugal); Pereira, L., E-mail: luiz@ua.pt [Departmento de Física e i3N – Instituto de Nanoestruturas, Nanomodelação e Nanofabricação, Universidade de Aveiro, 3810-193 Aveiro (Portugal)

    2016-09-15

    Highlights: • A simple WOLED for Solid State Lighting is proposed with high color stability. • Energy transfer and electroluminescence dynamics of a single RGB layer for WOLEDs. • White shade modulation and stability over large emitting areas and applied voltages. - Abstract: Solid State Lighting technologies based on Organic Light Emitting Diodes, became an interesting focus due to their unique properties. The use of a unique RGB active layer for white emission, although simple in theory, shows difficulty to stabilize both CIE coordinates and color modulation. In this work, a WOLED using a simple RGB layer, was developed achieving a high color stability and shade modulation. The RGB matrix comprises a blue host material NPB, doped with two guests, a green (Coumarin 153) and a red (DCM1) in low concentrations. The RGB layer carrier dynamics allows for the white emission in low device complexity and high stability. This was also shown independent of the white shade, obtained through small changes in the red dopant resulting in devices ranging from warm to cool white i.e. an easy color tuning. A detailed analysis of the opto-electrical behavior is made.

  13. Control of a White Organic Light Emitting Diode emission parameters using a single doped RGB active layer

    International Nuclear Information System (INIS)

    Pereira, D.; Pinto, A.; Califórnia, A.; Gomes, J.; Pereira, L.

    2016-01-01

    Highlights: • A simple WOLED for Solid State Lighting is proposed with high color stability. • Energy transfer and electroluminescence dynamics of a single RGB layer for WOLEDs. • White shade modulation and stability over large emitting areas and applied voltages. - Abstract: Solid State Lighting technologies based on Organic Light Emitting Diodes, became an interesting focus due to their unique properties. The use of a unique RGB active layer for white emission, although simple in theory, shows difficulty to stabilize both CIE coordinates and color modulation. In this work, a WOLED using a simple RGB layer, was developed achieving a high color stability and shade modulation. The RGB matrix comprises a blue host material NPB, doped with two guests, a green (Coumarin 153) and a red (DCM1) in low concentrations. The RGB layer carrier dynamics allows for the white emission in low device complexity and high stability. This was also shown independent of the white shade, obtained through small changes in the red dopant resulting in devices ranging from warm to cool white i.e. an easy color tuning. A detailed analysis of the opto-electrical behavior is made.

  14. Effects of long-term alendronate treatment on bone mineralisation, resorption parameters and biomechanics of single human vertebral trabeculae

    Directory of Open Access Journals (Sweden)

    M Krause

    2014-09-01

    Full Text Available Due to their well-established fracture risk reduction, bisphosphonates are the most frequently used therapeutic agent to treat osteoporosis. Bisphosphonates reduce fracture risk by suppressing bone resorption, but the lower bone turnover could have a negative impact on bone quality at the tissue level. Here, we directly assess the structural and mechanical characteristics of cancellous bone from the lumbar vertebrae (L5 in non-treated osteoporotic controls (n = 21, mid-term alendronate-treated osteoporotic patients (n = 6, and long-term alendronate-treated osteoporotic patients (n = 7. The strength and toughness of single trabeculae were evaluated, while the structure was characterised through measurements of microdamage accumulation, mineralisation distribution, and histological indices. The alendronate-treated cases had a reduced eroded surface (ES/BS, p < 0.001 and a higher bone mineralisation in comparison to non-treated controls (p = 0.037, which is indicative of low turnover associated with treatment. However, the amount of microdamage and the mechanical properties were similar among the control and treatment groups. As the tissue mineral density (TMD increased significantly with alendronate treatment compared to non-treated osteoporotic controls, the reduction in resorption cavities could counterbalance the higher TMD allowing the alendronate-treated bone to maintain its mechanical properties and resist microdamage accumulation. A multivariate analysis of the possible predictors supports the theory that multiple factors (e.g., body mass index, TMD, and ES/BS can impact the mechanical properties. Our results suggest that long-term alendronate treatment shows no adverse impact on mechanical cancellous bone characteristics.

  15. An expanded model of HIV cell entry phenotype based on multi-parameter single-cell data

    Directory of Open Access Journals (Sweden)

    Bozek Katarzyna

    2012-07-01

    Full Text Available Abstract Background Entry of human immunodeficiency virus type 1 (HIV-1 into the host cell involves interactions between the viral envelope glycoproteins (Env and the cellular receptor CD4 as well as a coreceptor molecule (most importantly CCR5 or CXCR4. Viral preference for a specific coreceptor (tropism is in particular determined by the third variable loop (V3 of the Env glycoprotein gp120. The approval and use of a coreceptor antagonist for antiretroviral therapy make detailed understanding of tropism and its accurate prediction from patient derived virus isolates essential. The aim of the present study is the development of an extended description of the HIV entry phenotype reflecting its co-dependence on several key determinants as the basis for a more accurate prediction of HIV-1 entry phenotype from genotypic data. Results Here, we established a new protocol of quantitation and computational analysis of the dependence of HIV entry efficiency on receptor and coreceptor cell surface levels as well as viral V3 loop sequence and the presence of two prototypic coreceptor antagonists in varying concentrations. Based on data collected at the single-cell level, we constructed regression models of the HIV-1 entry phenotype integrating the measured determinants. We developed a multivariate phenotype descriptor, termed phenotype vector, which facilitates a more detailed characterization of HIV entry phenotypes than currently used binary tropism classifications. For some of the tested virus variants, the multivariant phenotype vector revealed substantial divergences from existing tropism predictions. We also developed methods for computational prediction of the entry phenotypes based on the V3 sequence and performed an extrapolating calculation of the effectiveness of this computational procedure. Conclusions Our study of the HIV cell entry phenotype and the novel multivariate representation developed here contributes to a more detailed

  16. Single-well tracer test sensitivity w. r. to hydrofrac and matrix parameters (case study for the Horstberg site in the N-German Sedimentary Basin)

    Science.gov (United States)

    Ghergut, I.; Behrens, H.; Holzbecher, E.; Jung, R.; Sauter, M.; Tischner, T.

    2012-04-01

    At the geothermal pilot site Horstberg in the N-German Sedimentary Basin, a complex field experiment program was conducted (2003-2007) by the Federal Institute for Geosciences and Natural Resources (BGR) together with the Leibniz Institute for Applied Geosciences (GGA), aimed at evaluating the performance of innovative technologies for heat extraction, for direct use, from a single geothermal well[1],[2]. The envisaged single-well operation schemes comprised inter-layer circulation through a large-area hydrofrac (whose successful creation could thus be demonstrated), and single-screen 'huff-puff' in suitable (stimulated) layers, seated in sandstone-claystone formations in 3-4 km depth, with temperatures exceeding 160 ° C. Relying on Horstberg tracer-test data, we analyze heat and solute tracer transport in three characteristic hydraulic settings: (A) single-screen, multi-layer push-pull, with spiking and sampling at lower well-screen in low-permeability sandstone layer ('Detfurth'), from which hydrofrac propagation (through several adjacent layers) was initiated; (B) single-screen, single-layer push-pull, with spiking and sampling at upper well-screen within a more permeable sandstone layer ('Solling'); (C) inter-layer vertical push through above-mentioned hydrofrac, with spiking at well-screen of A, and sampling at well-screen of B. Owing to drill-hole deviation, the hydraulically-induced frac will, in its vertical propagation, reach the upper sandstone layer in a certain horizontal distance X from the upper well-screen, whose value turns out to be the major controlling parameter for the system's thermal lifetime under operation scheme C (values of X below ~8 m leading to premature thermal breakthrough, with the minimum-target rate of fluid turnover; however, the injection pressure required for maintaining the target outflow rate will also increase with X, which renders scheme C uneconomical, or technically-infeasible, when X exceeds ~15 m). Tracer signals in C

  17. Perioperative echocardiography-derived right ventricle function parameters and early outcomes after tetralogy of Fallot repair in mid-childhood: a single-center, prospective observational study.

    Science.gov (United States)

    Raj, Ravi; Puri, Goverdhan Dutt; Jayant, Aveek; Thingnam, Shyam Kumar Singh; Singh, Rana Sandip; Rohit, Manoj Kumar

    2016-11-01

    Right ventricular (RV) function alterations are invariably present in all patients after tetralogy of Fallot (TOF) repair. Unlike the developed world where most of the patients with TOF are corrected in infancy, average age of presentation and thus surgery for these patients in the developing world may be higher. We aimed to study the correlation between RV function parameters such as tricuspid annular peak systolic excursion (TAPSE), fractional area change (FAC), and tricuspid annular peak systolic velocity (S') with early outcome variables after intracardiac repair for TOF. Fifty patients with a preoperative diagnosis of tetralogy of Fallot scheduled for corrective surgery were included in this single-center, prospective observational study. A preoperative transthoracic echocardiogram was performed to measure RV function parameters (FAC0, TAPSE0, S'0). Transthoracic echocardiography was repeated postoperatively to measure FAC1, TAPSE1, S'1 (day 1) and FAC2, TAPSE2, and S'2 (day 3). The relationship between preoperative and postoperative RV function parameters with in-hospital mortality, duration of mechanical ventilation, and intensive care unit stay was studied. The median age of patients was 6 years (range 1-14 years). Multiple stepwise logistic regression analysis showed RV FAC as best predictor of clinical outcome. Area under the receiver operating characteristic curve for postoperative RV function parameters, that is, FAC, TAPSE, and S' to predict early or delayed recovery was 0.944, 0.875, and 0.655, respectively. Among the RV function parameters studied, RV FAC best predicted the early outcome variables after TOF repair, followed by TAPSE while lateral tricuspid annular velocity S' being the least predictive. © 2016, Wiley Periodicals, Inc.

  18. Efficiency of primary saliva secretion: an analysis of parameter dependence in dynamic single-cell and acinus models, with application to aquaporin knockout studies

    Science.gov (United States)

    Maclaren, Oliver J.; Sneyd, James; Crampin, Edmund J.

    2012-01-01

    Secretion from the salivary glands is driven by osmosis following the establishment of osmotic gradients between the lumen, the cell and the interstitium by active ion transport. We consider a dynamic model of osmotically-driven primary saliva secretion, and use singular perturbation approaches and scaling assumptions to reduce the model. Our analysis shows that isosmotic secretion is the most efficient secretion regime, and that this holds for single isolated cells and for multiple cells assembled into an acinus. For typical parameter variations, we rule out any significant synergistic effect on total water secretion of an acinar arrangement of cells about a single shared lumen. Conditions for the attainment of isosmotic secretion are considered, and we derive an expression for how the concentration gradient between the interstitium and the lumen scales with water and chloride transport parameters. Aquaporin knockout studies are interpreted in the context of our analysis and further investigated using simulations of transport efficiency with different membrane water permeabilities. We conclude that recent claims that aquaporin knockout studies can be interpreted as evidence against a simple osmotic mechanism are not supported by our work. Many of the results that we obtain are independent of specific transporter details, and our analysis can be easily extended to apply to models that use other proposed ionic mechanisms of saliva secretion. PMID:22258315

  19. Benchmark of AC and DC Active Power Decoupling Circuits for Second-Order Harmonic Mitigation in Kilowatt-Scale Single-Phase Inverters

    DEFF Research Database (Denmark)

    Qin, Zian; Tang, Yi; Loh, Poh Chiang

    2016-01-01

    efficiency and high power density is identified and comprehensively studied, and the commercially available film capacitors, the circuit topologies, and the control strategies adopted for active power decoupling are all taken into account. Then, an adaptive decoupling voltage control method is proposed...... to further improve the performance of dc decoupling in terms of efficiency and reliability. The feasibility and superiority of the identified solution for active power decoupling together with the proposed adaptive decoupling voltage control method are finally verified by both the simulation and experimental......This paper presents the benchmark study of ac and dc active power decoupling circuits for second order harmonic mitigation in kW scale single-phase inverters. First of all, a brief comparison of recently reported active power decoupling circuits is given, and the best solution that can achieve high...

  20. Studies on the growth aspects, structural, thermal, dielectric and third order nonlinear optical properties of solution grown 4-methylpyridinium p-nitrophenolate single crystal

    Science.gov (United States)

    Devi, S. Reena; Kalaiyarasi, S.; Zahid, I. MD.; Kumar, R. Mohan

    2016-11-01

    An ionic organic optical crystal of 4-methylpyridinium p-nitrophenolate was grown from methanol by slow evaporation method at ambient temperature. Powder and single crystal X-ray diffraction studies revealed the crystal system and its crystalline perfection. The rocking curve recorded from HRXRD study confirmed the crystal quality. FTIR spectral analysis confirmed the functional groups present in the title compound. UV-visible spectral study revealed the optical window and band gap of grown crystal. The thermal, electrical and surface laser damage threshold properties of harvested crystal were examined by using TGA/DTA, LCR/Impedance Analyzer and Nd:YAG laser system respectively. The third order nonlinear optical property of grown crystal was elucidated by Z-scan technique.

  1. Atomic scale studies of La/Sr ordering in La2-2xSr1+2xMn2O7 single crystals

    KAUST Repository

    Roldan, Manuel

    2016-12-21

    Many fascinating properties of materials depend strongly on the local chemical environment. This is the case for many complex oxides, such as materials with colossal magnetoresistance, where small variations of composition at the atomic scale can affect drastically the macroscopic properties. The main objective of the present work is to analyze the local chemical composition with atomic resolution and to find out if any underlying chemical order is in any way connected to the magnetic properties of double perovskite La2-2xSr1+2xMn2O7 (LSMO) manganite oxides. For these compounds, charge and orbital ordering are observed for some doping values near x = 0.50 [1, 2]. For this purpose, we have use aberration corrected scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS) measurements and also theoretical simulations. We have compared different compositions within three distinct magnetic regions of the phase diagram: a ferromagnetic metallic sample with x=0.36, an insulating, antiferromagnetic (AF) x=0.56 and an additional AF x=0.50 sample which also exhibits charge ordering. High angle annular dark-field (HAADF) images, also known as Z-contrast, confirm that our single crystals exhibit high crystal quality. No secondary phases or defects are observed. Figure 1 displays an atomic resolution image obtained with the c-axis perpendicular to the electron beam of a x=0.50 sample. The perovskite (P)-like planes and the rock salt (R)-like planes are clearly observed, highlighted in green and red, respectively, on the image. The P-like planes exhibit a slightly high contrast, suggesting a possible La enrichment. EELS atomic resolution maps (inset) support a high degree of La segregation on those planes, while R-like planes are Sr rich. However, due to dechanneling of the beam, detailed image simulations are essential to accurately quantify the local chemical composition in an atomic column-by-atomic column fashion. For all our

  2. Single-energy pediatric chest computed tomography with spectral filtration at 100 kVp: effects on radiation parameters and image quality

    International Nuclear Information System (INIS)

    Bodelle, Boris; Fischbach, Constanze; Booz, Christian; Yel, Ibrahim; Frellesen, Claudia; Kaup, Moritz; Beeres, Martin; Vogl, Thomas J.; Scholtz, Jan-Erik

    2017-01-01

    Most of the applied radiation dose at CT is in the lower photon energy range, which is of limited diagnostic importance. To investigate image quality and effects on radiation parameters of 100-kVp spectral filtration single-energy chest CT using a tin-filter at third-generation dual-source CT in comparison to standard 100-kVp chest CT. Thirty-three children referred for a non-contrast chest CT performed on a third-generation dual-source CT scanner were examined at 100 kVp with a dedicated tin filter with a tube current-time product resulting in standard protocol dose. We compared resulting images with images from children examined using standard single-source chest CT at 100 kVp. We assessed objective and subjective image quality and compared radiation dose parameters. Radiation dose was comparable for children 5 years old and younger, and it was moderately decreased for older children when using spectral filtration (P=0.006). Effective tube current increased significantly (P=0.0001) with spectral filtration, up to a factor of 10. Signal-to-noise ratio and image noise were similar for both examination techniques (P≥0.06). Subjective image quality showed no significant differences (P≥0.2). Using 100-kVp spectral filtration chest CT in children by means of a tube-based tin-filter on a third-generation dual-source CT scanner increases effective tube current up to a factor of 10 to provide similar image quality at equivalent dose compared to standard single-source CT without spectral filtration. (orig.)

  3. Single-energy pediatric chest computed tomography with spectral filtration at 100 kVp: effects on radiation parameters and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Bodelle, Boris; Fischbach, Constanze; Booz, Christian; Yel, Ibrahim; Frellesen, Claudia; Kaup, Moritz; Beeres, Martin; Vogl, Thomas J.; Scholtz, Jan-Erik [Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

    2017-06-15

    Most of the applied radiation dose at CT is in the lower photon energy range, which is of limited diagnostic importance. To investigate image quality and effects on radiation parameters of 100-kVp spectral filtration single-energy chest CT using a tin-filter at third-generation dual-source CT in comparison to standard 100-kVp chest CT. Thirty-three children referred for a non-contrast chest CT performed on a third-generation dual-source CT scanner were examined at 100 kVp with a dedicated tin filter with a tube current-time product resulting in standard protocol dose. We compared resulting images with images from children examined using standard single-source chest CT at 100 kVp. We assessed objective and subjective image quality and compared radiation dose parameters. Radiation dose was comparable for children 5 years old and younger, and it was moderately decreased for older children when using spectral filtration (P=0.006). Effective tube current increased significantly (P=0.0001) with spectral filtration, up to a factor of 10. Signal-to-noise ratio and image noise were similar for both examination techniques (P≥0.06). Subjective image quality showed no significant differences (P≥0.2). Using 100-kVp spectral filtration chest CT in children by means of a tube-based tin-filter on a third-generation dual-source CT scanner increases effective tube current up to a factor of 10 to provide similar image quality at equivalent dose compared to standard single-source CT without spectral filtration. (orig.)

  4. Single session, intrauser repeatability of anterior chamber biometric and corneal pachy-volumetric parameters using a new Scheimpflug+Placido device.

    Science.gov (United States)

    Prakash, Gaurav; Srivastava, Dhruv

    2016-01-01

    To analyze single session, intrauser reliability of a Scheimpflug device for anterior chamber (AC) and corneal parameters. In this observational study, 100 normal candidates underwent Scheimpflug analysis with Sirius 3D Rotating Scheimpflug Camera and Topography System (Costruzione Strumenti Oftalmici, Italy). Two scans in dark room conditions were performed by the same experienced user. The candidates were asked to keep both eyes closed for 5min before the scans. Exclusion criteria were previous ocular surgery, corneal scarring and anterior segment/posterior segment anomalies. Only the right eyes were used for the analysis. Both corneal (central, minimum, and apical thickness, volume, horizontal visible iris diameter, and apical curvature) and anterior chamber (volume, depth, angle, horizontal diameter) measurements were evaluated. There was no difference in the means of repeated measurements (p>0.05, ANOVA). Intraclass correlations between the measures were high and ranged from 0.995-0.997 for corneal to 0.964-0.997 for anterior chamber (AC) parameters. The precision of repeatability measures (1.96×Sw) was approximately 5μ for the central and minimum corneal thickness, 8μ for the apical corneal thickness, 0.06mm for AC (anterior chamber) depth and less than 2° for the AC angle. Sirius Scheimpflug system has high repeatability for both corneal and AC parameters in normal eyes. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  5. First-order phase transitions in CaFe{sub 2}As{sub 2} single crystal: a local probe study

    Energy Technology Data Exchange (ETDEWEB)

    Alzamora, M; Munevar, J; Baggio-Saitovitch, E [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150, Urca 22290-180, Rio de Janeiro, RJ (Brazil); Bud' ko, S L; Ni Ni; Canfield, P C [Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Sanchez, D R [Universidade Federal Fluminense, Instituto de Fisica, Avenida Milton Tavares de Souza, s/n-Campus da Praia Vermelha, 24210-346 Niteroi, RJ (Brazil)

    2011-04-13

    {sup 57}Fe Moessbauer spectroscopy has been used to investigate the structural and magnetic phase transitions of CaFe{sub 2}As{sub 2} (T{sub N} = 173 K) single crystals. For this compound we found that V{sub ZZ} is positive and parallel to the c-axis of the tetragonal structure. For CaFe{sub 2}As{sub 2} a magnetic hyperfine field B{sub hf} was observed at the {sup 57}Fe nucleus below T{sub N} {approx} 173 K. Analysis of the temperature dependence of B{sub hf} data using the Bean-Rodbell model shows that the Fe spins undergo a first-order magnetic transition at {approx} 173 K. A collinear antiferromagnetic structure is established below this temperature with the Fe spin lying in the (a, b) plane. Below T{sub N} the paramagnetic fraction of Fe decreases down to 150 K and for lower temperatures all the Fe spins are magnetically ordered.

  6. 139La NMR investigation of the charge and spin order in a La1.885Sr0.115CuO4 single crystal

    Science.gov (United States)

    Arsenault, A.; Takahashi, S. K.; Imai, T.; He, W.; Lee, Y. S.; Fujita, M.

    2018-02-01

    139La NMR is suited for investigations into magnetic properties of La2CuO4 -based cuprates in the vicinity of their magnetic instabilities, owing to the modest hyperfine interactions between 139La nuclear spins and Cu electron spins. We report comprehensive 139La NMR measurements on a single-crystal sample of high-Tc superconductor La1.885Sr0.115CuO4 in a broad temperature range across the charge and spin order transitions (Tcharge≃80 K, Tspinneutron≃Tc=30 K). From the high-precision measurements of the linewidth for the nuclear spin Iz=+1 /2 to -1 /2 central transition, we show that paramagnetic line broadening sets in precisely at Tcharge due to enhanced spin correlations within the CuO2 planes. Additional paramagnetic line broadening ensues below ˜35 K, signaling that Cu spins in some segments of CuO2 planes are on the verge of three-dimensional magnetic order. A static hyperfine magnetic field arising from ordered Cu moments along the a b plane, however, begins to develop only below Tspinμ S R=15 -20 K, where earlier muon spin rotation measurements detected Larmor precession for a small volume fraction (˜20 % ) of the sample. Based on the measurement of 139La nuclear-spin-lattice relaxation rate 1 /T1 , we also show that charge order triggers enhancement of low-frequency Cu spin fluctuations inhomogeneously; a growing fraction of 139La sites is affected by enhanced low-frequency spin fluctuations toward the eventual magnetic order, whereas a diminishing fraction continues to exhibit a behavior analogous to the optimally superconducting phase even below Tcharge. These 139La NMR results corroborate our recent 63Cu NMR observation that a very broad, anomalous winglike signal gradually emerges below Tcharge, whereas the normally behaving, narrower main peak is gradually wiped out [T. Imai et al., Phys. Rev. B 96, 224508 (2017), 10.1103/PhysRevB.96.224508]. Furthermore, we show that the enhancement of low-energy spin excitations in the low-temperature regime

  7. Optimization of helical acquisition parameters to preserve uniformity of mouse whole body using multipinhole collimator in single-photon emission computed tomography

    Directory of Open Access Journals (Sweden)

    Naoyuki Ukon

    Full Text Available Focusing on whole-body uniformity in small-animal single-photon emission computed tomography (SPECT, we examined the optimal helical acquisition parameters using five-pinhole collimators for mouse imaging. SPECT images of an 80-mm-long cylindrical phantom with 99mTc solution were acquired using an Inveon multimodality imaging platform. The bed travels used in this study were 0, 30, 60, 90 and 120 mm, and the numbers of revolutions traversed during the SPECT scan were 1.0, 2.0, 3.0, 4.0, 5.0 and 7.0, respectively. Artifacts that degrade uniformity in reconstructed images were conspicuous when the bed travel was smaller than the object length. Regarding the distal-to-center ratio (DCR of SPECT values in the object’s axial direction, the DCR nearest to the ideal ratio of 1.00 was 1.02 in the optimal uniformity with 4.0 revolutions and a bed travel of 120 mm. Moreover, the helical acquisition using these parameters suppressed the formation of artifacts. We proposed the optimal parameters in whole-body helical SPECT; the bed travel was sufficiently larger than the object length; the 4.0 or more revolutions were required for a pitch of approximately 30 mm/revolution. The optimal acquisition parameters in SPECT to preserve uniformity would contribute to the accurate quantification of whole-body biodistribution. Keywords: Helical acquisition, Multipinhole collimator, Computed tomography, SPECT

  8. Investigation on the growth, spectral, lifetime, mechanical analysis and third-order nonlinear optical studies of L-methionine admixtured D-mandelic acid single crystal: A promising material for nonlinear optical applications

    Science.gov (United States)

    Jayaprakash, P.; Sangeetha, P.; Kumari, C. Rathika Thaya; Caroline, M. Lydia

    2017-08-01

    A nonlinear optical bulk single crystal of L-methionine admixtured D-mandelic acid (LMDMA) has been grown by slow solvent evaporation technique using water as solvent at ambient temperature. The crystallized LMDMA single crystal subjected to single crystal X-ray diffraction study confirmed monoclinic system with the acentric space group P21. The FTIR analysis gives information about the modes of vibration in the various functional groups present in LMDMA. The UV-visible spectral analysis assessed the optical quality and linear optical properties such as extinction coefficient, reflectance, refractive index and from which optical conductivity and electric susceptibility were also evaluated. The frequency doubling efficiency was observed using Kurtz Perry powder technique. A multiple shot laser was utilized to evaluate the laser damage threshold energy of the crystal. Discrete thermodynamic properties were carried out by TG-DTA studies. The hardness, Meyer's index, yield strength, elastic stiffness constant, Knoop hardness, fracture toughness and brittleness index were analyzed using Vickers microhardness tester. Layer growth pattern and the surface defect were examined by chemical etching studies using optical microscope. Fluorescence emission spectrum was recorded and lifetime was also studied. The electric field response of crystal was investigated from the dielectric studies at various temperatures at different frequencies. The third-order nonlinear optical response in LMDMA has been investigated using Z-scan technique with He-Ne laser at 632.8 nm and nonlinear parameters such as refractive index (n2), absorption coefficient (β) and susceptibility (χ3) investigated extensively for they are in optical phase conjucation, high-speed optical switches and optical dielectric devices.

  9. A variable parameter single degree-of-freedom model for predicting the effects of sitting posture and vibration magnitude on the vertical apparent mass of the human body.

    Science.gov (United States)

    Toward, Martin G R; Griffin, Michael J

    2010-01-01

    Models of the vertical apparent mass of the human body are mostly restricted to a sitting posture unsupported by a backrest and ignore the variations in apparent mass associated with changes in posture and changes in the magnitude of vibration. Using findings from experimental research, this study fitted a single degree-of-freedom lumped parameter model to the measured vertical apparent mass of the body measured with a range of sitting postures and vibration magnitudes. The resulting model reflects the effects of reclining a rigid backrest or reclining a foam backrest (from 0 to 30 degrees), the effects of moving the hands from the lap to a steering wheel, the effects of moving the horizontal position of the feet, and the effects of vibration magnitude (from 0.125 to 1.6 ms(-2) r.m.s.). The error between the modelled and the measured apparent mass was minimised, for both the apparent masses of individual subjects and the median apparent masses of groups of 12 subjects, for each sitting posture and each vibration magnitude. Trends in model parameters, the damping ratios, and the damped natural frequencies were identified as a function of the model variables and show the effects of posture and vibration magnitude on body dynamics. For example, contact with a rigid backrest increased the derived damped natural frequency of the principal resonance as a result of reduced moving mass and increased stiffness. When the rigid backrest was reclined from 0 to 30º, the damping decreased and the resonance frequency increased as a result of reduced moving mass. It is concluded that, by appropriate variations in model parameters, a single degree-of-freedom model can provide a useful fit to the vertical apparent mass of the human body over a wide range of postures and vibration magnitudes. When measuring or modelling seat transmissibility, it may be difficult to justify an apparent mass model with more than a single degree-of-freedom if it does not reflect the large influences of

  10. 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...

  11. 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

  12. Contact effects analyzed by a parameter extraction method based on a single bottom-gate/top-contact organic thin-film transistor

    Science.gov (United States)

    Takagaki, Shunsuke; Yamada, Hirofumi; Noda, Kei

    2018-03-01

    Contact effects in organic thin-film transistors (OTFTs) were examined by using our previously proposed parameter extraction method from the electrical characteristics of a single staggered-type device. Gate-voltage-dependent contact resistance and channel mobility in the linear regime were evaluated for bottom-gate/top-contact (BGTC) pentacene TFTs with active layers of different thicknesses, and for pentacene TFTs with contact-doped layers prepared by coevaporation of pentacene and tetrafluorotetracyanoquinodimethane (F4TCNQ). The extracted parameters suggested that the influence of the contact resistance becomes more prominent with the larger active-layer thickness, and that contact-doping experiments give rise to a drastic decrease in the contact resistance and a concurrent considerable improvement in the channel mobility. Additionally, the estimated energy distributions of trap density in the transistor channel probably reflect the trap filling with charge carriers injected into the channel regions. The analysis results in this study confirm the effectiveness of our proposed method, with which we can investigate contact effects and circumvent the influences of characteristic variations in OTFT fabrication.

  13. Variation of intrinsic magnetic parameters of single domain Co-N interstitial nitrides synthesized via hexa-ammine cobalt nitrate route

    International Nuclear Information System (INIS)

    Ningthoujam, R.S.; Panda, R.N.; Gajbhiye, N.S.

    2012-01-01

    Highlights: ► Variation of intrinsic magnetic parameters of Co-N. ► Synthesis by hexa-ammine cobalt complex route. ► Tuning of coercivity by variation of size. - Abstract: We report the variation of Curie temperature (T c ) and coercivity (H c ) of the single domain Co-N interstitial materials synthesized via nitridation of the hexa-ammine Cobalt(III) nitrate complex at 673 K. Co-N materials crystallize in the fcc cubic structure with unit cell parameter, a = 3.552 Å. The X-ray diffraction (XRD) peaks are broader indicating the materials to be nano-structured with crystallite sizes of 5–14 nm. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies confirm the nanocrystalline nature of the materials. TEM images show chain-like clusters indicating dipolar interactions between the particles. Magnetic studies focus on the existence of giant magnetic Co atoms in the Co-N lattice that are not influenced by the thermal relaxation. The values of the H c could be tuned with the dimension of the particles. The values of T c of the nitride materials are masked by the onset of the ferromagnetic to superparamagnetic transition at higher temperatures. Thermomagnetic studies show an increasing trend in the Curie temperature, T c , with decrease in particle dimension. This result has been explained qualitatively on the basis of ferromagnetic to superparamagnetic transition and finite size scaling effects.

  14. Mechanism of adsorption of single and double stranded DNA on gold and silver nanoparticles: Investigating some important parameters in bio-sensing applications.

    Science.gov (United States)

    Farkhari, Nahid; Abbasian, Sara; Moshaii, Ahmad; Nikkhah, Maryam

    2016-12-01

    The mechanism of adsorption of single and double stranded DNAs on colloidal gold and silver nanoparticles has been studied by measuring the resistance of the nanoparticles, surrounded by various oligonucleotides, against salt induced aggregation. It is shown that both single and double stranded DNAs can be adsorbed on the metal nanoparticles and the adsorption strength is determined by the interaction between various bases of DNA and the nanoparticles. By changing the salt concentration, the difference between adsorption of various DNA strands on the nanoparticles can be specified. The results indicate that a key parameter in success of a sensing assay of DNA hybridization is the salt concentration which should be greater than a minimum threshold depending on the nanoparticles characteristics. We have also investigated the interaction mechanism between various DNA bases with the metal nanoparticles. For both gold and silver nanoparticles, adenine has the highest and thymine has the lowest attachment to the nanoparticles. From surface enhanced Raman spectroscopy (SERS) data of various bases in the presence of gold nanoparticles, the probable interaction points in the bases with the nanoparticles have been determined, which are mainly the nitrogen sites of these oligonucleotides. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Single and combined effects of vitamin C and oregano essential oil in diet, on growth performance, and blood parameters of broiler chicks reared under heat stress condition

    Science.gov (United States)

    Ghazi, Shahab; Amjadian, Tahere; Norouzi, Shokufeh

    2015-08-01

    This study was conducted to evaluate the effects of adding vitamin C (VC), oregano essential oil (OR), or their combination in diet, on growth performance, and blood parameters of broiler chicks reared under heat stress (HS) condition (38 °C). One-day-old 240 male broilers were randomly assigned to four treatment groups, six replicates of ten birds each. The birds were fed with either a basal diet or a basal diet supplemented with either 200 mg L-ascorbic acid/kg of diet, 250 mg of oregano essential oil/kg of diet, or 200 mg L-ascorbic acid plus 250 mg of oregano essential oil/kg of diet. Average daily feed intake (ADFI), average daily gain (ADG), and feed conversion ratio (FCR) were obtained for 42 days of age and at the end of the experiment (day 42); birds were bled to determine some blood parameters and weighted for final body weight (BW). Feeding birds with diets supplemented with oregano essential oil and vitamin C in a single or combined form increased ADG ( P > 0.05). Also BW increased and feed efficiency decreased ( P vitamin C ( P > 0.05). Supplemental oregano essential oil and vitamin C in a combined form decreased the serum concentration of corticosterone, triglycerides, glucose, and MDA ( P vitamin C were seen in broiler chicks supplemented with vitamin C. From the results of the present experiment, it can be concluded that diet supplementation by combined oregano essential oil and vitamin C could have beneficial effects on some blood parameters of broiler chicks reared under heat stress condition.

  16. Highly Ordered Single Crystalline Nanowire Array Assembled Three-Dimensional Nb3O7(OH) and Nb2O5 Superstructures for Energy Storage and Conversion Applications.

    Science.gov (United States)

    Zhang, Haimin; Wang, Yun; Liu, Porun; Chou, Shu Lei; Wang, Jia Zhao; Liu, Hongwei; Wang, Guozhong; Zhao, Huijun

    2016-01-26

    Three-dimensional (3D) metal oxide superstructures have demonstrated great potentials for structure-dependent energy storage and conversion applications. Here, we reported a facile hydrothermal method for direct growth of highly ordered single crystalline nanowire array assembled 3D orthorhombic Nb3O7(OH) superstructures and their subsequent thermal transformation into monoclinic Nb2O5 with well preserved 3D nanowire superstructures. The performance of resultant 3D Nb3O7(OH) and Nb2O5 superstructures differed remarkably when used for energy conversion and storage applications. The thermally converted Nb2O5 superstructures as anode material of lithium-ion batteries (LiBs) showed higher capacity and excellent cycling stability compared to the Nb3O7(OH) superstructures, while directly hydrothermal grown Nb3O7(OH) nanowire superstructure film on FTO substrate as photoanode of dye-sensitized solar cells (DSSCs) without the need for further calcination exhibited an overall light conversion efficiency of 6.38%, higher than that (5.87%) of DSSCs made from the thermally converted Nb2O5 film. The high energy application performance of the niobium-based nanowire superstructures with different chemical compositions can be attributed to their large surface area, superior electron transport property, and high light utilization efficiency resulting from a 3D superstructure, high crystallinity, and large sizes. The formation process of 3D nanowire superstructures before and after thermal treatment was investigated and discussed based on our theoretical and experimental results.

  17. Ordered Single-Crystalline Anatase TiO2Nanorod Clusters Planted on Graphene for Fast Charge Transfer in Photoelectrochemical Solar Cells.

    Science.gov (United States)

    Wang, Yang; Liu, Xueqin; Li, Zhen; Cao, Ya; Li, Yinchang; Liu, Xupo; Jia, Songru; Zhao, Yanli

    2017-07-01

    Achieving efficient charge transport is a great challenge in nanostructured TiO 2 -electrode-based photoelectrochemical cells. Inspired by excellent directional charge transport and the well-known electroconductibility of 1D anatase TiO 2 nanostructured materials and graphene, respectively, planting ordered, single-crystalline anatase TiO 2 nanorod clusters on graphene sheets (rGO/ATRCs) via a facial one-pot solvothermal method is reported. The hierarchical rGO/ATRCs nanostructure can serve as an efficient light-harvesting electrode for dye-sensitized solar cells. In addition, the obtained high-crystallinity anatase TiO 2 nanorods in rGO/ATRCs possess a lower density of trap states, thus facilitating diffusion-driven charge transport and suppressing electron recombination. Moreover, the novel architecture significantly enhances the trap-free charge diffusion coefficient, which contributes to superior electron mobility properties. By virtue of more efficient charge transport and higher energy conversion efficiency, the rGO/ATRCs developed in this work show significant advantages over conventional rGO-TiO 2 nanoparticle counterparts in photoelectrochemical cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Differential distributions for t-channel single top-quark production and decay at next-to-next-to-leading order in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Edmond L.; Gao, Jun; Zhu, Hua Xing

    2017-11-01

    We present a detailed phenomenological study of the next-to-next-to-leading order (NNLO) QCD corrections for t-channel single top (anti-)quark production and its semi-leptonic decay at the CERN Large Hadron Collider (LHC). We find the NNLO corrections for the total inclusive rates at the LHC with different center of mass energies are generally smaller than the NLO corrections, indicative of improved convergence. However, they can be large for differential distributions, reaching a level of 10% or more in certain regions of the transverse momentum distributions of the top (anti-)quark and the pseudo-rapidity distributions of the leading jet in the event. In all cases the perturbative hard-scale uncertainties are greatly reduced after the NNLO corrections are included. We also show a comparison of the normalized parton-level distributions to recent data from the 8 TeV measurement of the ATLAS collaboration. The NNLO corrections tend to shift the theoretical predictions closer to the measured transverse momentum distribution of the top (anti)-quark. Importantly, for the LHC at 13 TeV, we present NNLO cross sections in a fiducial volume with decays of the top quark included.

  19. A new first-order turbulence mixing model for the stable atmospheric boundary-layer: development and testing in large-eddy and single column models

    Science.gov (United States)

    Huang, J.; Bou-Zeid, E.; Golaz, J.

    2011-12-01

    Parameterization of the stably-stratified atmospheric boundary-layer is of crucial importance to different aspects of numerical weather prediction at regional scales and climate modeling at global scales, such as land-surface temperature forecasts, fog and frost prediction, and polar climate. It is well-known that most operational climate models require excessive turbulence mixing of the stable boundary-layer to prevent decoupling of the atmospheric component from the land component under strong stability, but the performance of such a model is unlikely to be satisfactory under weakly and moderately stable conditions. In this study we develop and test a general turbulence mixing model of the stable boundary-layer which works under different stabilities and for steady as well as unsteady conditions. A-priori large-eddy simulation (LES) tests are presented to motivate and verify the new parameterization. Subsequently, an assessment of this model using the GFDL single-column model (SCM) is performed. Idealized test cases including continuously varying stability, as well as stability discontinuity, are used to test the new SCM against LES results. A good match of mean and flux profiles is found when the new parameterization is used, while other traditional first-order turbulence models using the concept of stability function perform poorly. SCM spatial resolution is also found to have little impact on the performance of the new turbulence closure, but temporal resolution is important and a numerical stability criterion based on the model time step is presented.

  20. Influence of technological parameters on the geometry of single-track laser clad nickel based alloy on grey cast iron substrate

    Science.gov (United States)

    Gusev, D. S.; Lyukhter, A. B.

    2017-12-01

    On the example of glass forming equipment, the surfaces of which must have high wear resistance during repeated contacts with molten glass, a study was made of laser cladding of nickel based alloys on a substrate of gray cast iron. In study the shapes of individual tracks are investigated with varying laser radiation power, processing speed and powder feed rate. The influence of technological parameters on the width and height of the clad is shown. A similarity is found between the two principles of measuring the dilution through linear dimensions and the areas of track in cross section. A high correlation between dilution and laser radiation power over a wide range of speeds has been established, which has made it possible to develop a scheme of control laser cladding process with achieving a low level of dilution in order to minimize the heat effect zone (HAZ).

  1. Variation of intrinsic magnetic parameters of single domain Co-N interstitial nitrides synthesized via hexa-ammine cobalt nitrate route

    Energy Technology Data Exchange (ETDEWEB)

    Ningthoujam, R.S. [Department of Chemistry, Indian Institute of Technology, Kanpur 208016 (India); Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Panda, R.N., E-mail: rnp@bits-goa.ac.in [Chemistry Group, Birla Institute of Technology and Science-Pilani, Goa Campus, Zuari Nagar, Goa 403726 (India); Gajbhiye, N.S. [Department of Chemistry, Indian Institute of Technology, Kanpur 208016 (India)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Variation of intrinsic magnetic parameters of Co-N. Black-Right-Pointing-Pointer Synthesis by hexa-ammine cobalt complex route. Black-Right-Pointing-Pointer Tuning of coercivity by variation of size. - Abstract: We report the variation of Curie temperature (T{sub c}) and coercivity (H{sub c}) of the single domain Co-N interstitial materials synthesized via nitridation of the hexa-ammine Cobalt(III) nitrate complex at 673 K. Co-N materials crystallize in the fcc cubic structure with unit cell parameter, a = 3.552 Angstrom-Sign . The X-ray diffraction (XRD) peaks are broader indicating the materials to be nano-structured with crystallite sizes of 5-14 nm. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies confirm the nanocrystalline nature of the materials. TEM images show chain-like clusters indicating dipolar interactions between the particles. Magnetic studies focus on the existence of giant magnetic Co atoms in the Co-N lattice that are not influenced by the thermal relaxation. The values of the H{sub c} could be tuned with the dimension of the particles. The values of T{sub c} of the nitride materials are masked by the onset of the ferromagnetic to superparamagnetic transition at higher temperatures. Thermomagnetic studies show an increasing trend in the Curie temperature, T{sub c}, with decrease in particle dimension. This result has been explained qualitatively on the basis of ferromagnetic to superparamagnetic transition and finite size scaling effects.

  2. 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.

  3. Albiglutide, a weekly GLP-1 receptor agonist, improves glycemic parameters in Japanese patients with type 2 diabetes over 1 year when added to single oral antidiabetic drugs.

    Science.gov (United States)

    Okuda, Inaha; Wilson, Timothy H; Yue, Lin; Nakajima, Hiromu; Carr, Molly C; Tsuboi, Maho; Nino, Antonio; Seino, Yutaka

    2017-03-01

    To evaluate the safety and efficacy of once weekly albiglutide added to a single oral antidiabetic drug (OAD) in Japanese patients with inadequately controlled type 2 diabetes mellitus (T2DM). In this phase 3, 1 year study (NCT01777282), patients (N = 374) received albiglutide 30 mg plus a single OAD (sulfonylurea [n = 120], biguanide [n = 67)], glinide [n = 65], thiazolidinedione [n = 61], or α-glucosidase inhibitor [n = 61]). Albiglutide could be increased to 50 mg after Week 4, based on glycemic criteria. Primary endpoints were the incidence of adverse events (AEs) and hypoglycemia; secondary endpoints were changes from baseline at Week 52 in HbA 1c and fasting plasma glucose (FPG), proportion of patients achieving HbA 1c ≤7.0%, and withdrawals due to hyperglycemia. On-therapy AEs occurred in 78.6% of patients and serious AEs in 2.1%. Common AEs were nasopharyngitis (32.6%), constipation (7.2%), and diabetic retinopathy (5.3%). No serious AEs occurred more than once or were reported in >1 patient. Hypoglycemia occurred in 6.4% of patients, mostly in the albiglutide + sulfonylurea (14.2%) and the albiglutide + glinide (6.2%) groups. Albiglutide was uptitrated in 53.2% of patients. Mean baseline HbA 1c was 8.1%. Mean decreases from baseline in HbA 1c were observed with the addition of albiglutide to thiazolidinediones (-1.42%), α-glucosidase inhibitors (-1.39%), sulfonylureas (-1.04%), glinides (-0.95%), and biguanides (-0.94%). HbA 1c of 50% of patients and mean reductions in FPG were achieved in all groups. Mean changes from baseline in body weight ranged from +0.52 kg (albiglutide + thiazolidinedione) to -0.33 kg (albiglutide + biguanide). Limitations of the study included open label treatment that was not randomized. When combined with a single OAD in Japanese patients with inadequately controlled T2DM, albiglutide led to favorable changes in all glycemic parameters, with minor changes in body weight

  4. 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.

  5. Self-Anchored Catalyst Interface Enables Ordered Via Array Formation from Submicrometer to Millimeter Scale for Polycrystalline and Single-Crystalline Silicon.

    Science.gov (United States)

    Kim, Jeong Dong; Kim, Munho; Kong, Lingyu; Mohseni, Parsian K; Ranganathan, Srikanth; Pachamuthu, Jayavel; Chim, Wai Kin; Chiam, Sing Yang; Coleman, James J; Li, Xiuling

    2018-03-14

    Defying text definitions of wet etching, metal-assisted chemical etching (MacEtch), a solution-based, damage-free semiconductor etching method, is directional, where the metal catalyst film sinks with the semiconductor etching front, producing 3D semiconductor structures that are complementary to the metal catalyst film pattern. The same recipe that works perfectly to produce ordered array of nanostructures for single-crystalline Si (c-Si) fails completely when applied to polycrystalline Si (poly-Si) with the same doping type and level. Another long-standing challenge for MacEtch is the difficulty of uniformly etching across feature sizes larger than a few micrometers because of the nature of lateral etching. The issue of interface control between the catalyst and the semiconductor in both lateral and vertical directions over time and over distance needs to be systematically addressed. Here, we present a self-anchored catalyst (SAC) MacEtch method, where a nanoporous catalyst film is used to produce nanowires through the pinholes, which in turn physically anchor the catalyst film from detouring as it descends. The systematic vertical etch rate study as a function of porous catalyst diameter from 200 to 900 nm shows that the SAC-MacEtch not only confines the etching direction but also enhances the etch rate due to the increased liquid access path, significantly delaying the onset of the mass-transport-limited critical diameter compared to nonporous catalyst c-Si counterpart. With this enhanced mass transport approach, vias on multistacks of poly-Si/SiO 2 are also formed with excellent vertical registry through the polystack, even though they are separated by SiO 2 which is readily removed by HF alone with no anisotropy. In addition, 320 μm square through-Si-via (TSV) arrays in 550 μm thick c-Si are realized. The ability of SAC-MacEtch to etch through poly/oxide/poly stack as well as more than half millimeter thick silicon with excellent site specificity for a wide

  6. 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...

  7. The accuracy of the crystal chemical parameters at high-pressure conditions from single-crystal X-ray diffraction in diamond-anvil cell

    DEFF Research Database (Denmark)

    Periotto, Benedetta

    applications also in the materials science as it can provide useful information about the properties and performance of new materials. Over the past decades, the research in this field has been strongly developed due to the advances in computer capabilities and to the technological improvements of X......-ray instruments. At the same time, the high-pressure experiments have benefited by the strong improvements on the high-pressure devices, in particular the diamond-anvil cell (DAC). The aim of this research project is to assess the quality of the data obtained by means of the single-crystal X-ray diffraction...... started with a comparison between two different DACs, in order to define the capabilities of one of the most common types of pressure device, the ETH-type DAC. Application examples of data quality analysis have been conducted on pyroxenes (NaInSi2O6, orthoenstatite MgSiO3 and LiCrSi2O6), which...

  8. A systematic study on the influencing parameters and improvement of quantitative analysis of multi-component with single marker method using notoginseng as research subject.

    Science.gov (United States)

    Wang, Chao-Qun; Jia, Xiu-Hong; Zhu, Shu; Komatsu, Katsuko; Wang, Xuan; Cai, Shao-Qing

    2015-03-01

    A new quantitative analysis of multi-component with single marker (QAMS) method for 11 saponins (ginsenosides Rg1, Rb1, Rg2, Rh1, Rf, Re and Rd; notoginsenosides R1, R4, Fa and K) in notoginseng was established, when 6 of these saponins were individually used as internal referring substances to investigate the influences of chemical structure, concentrations of quantitative components, and purities of the standard substances on the accuracy of the QAMS method. The results showed that the concentration of the analyte in sample solution was the major influencing parameter, whereas the other parameters had minimal influence on the accuracy of the QAMS method. A new method for calculating the relative correction factors by linear regression was established (linear regression method), which demonstrated to decrease standard method differences of the QAMS method from 1.20%±0.02% - 23.29%±3.23% to 0.10%±0.09% - 8.84%±2.85% in comparison with the previous method. And the differences between external standard method and the QAMS method using relative correction factors calculated by linear regression method were below 5% in the quantitative determination of Rg1, Re, R1, Rd and Fa in 24 notoginseng samples and Rb1 in 21 notoginseng samples. And the differences were mostly below 10% in the quantitative determination of Rf, Rg2, R4 and N-K (the differences of these 4 constituents bigger because their contents lower) in all the 24 notoginseng samples. The results indicated that the contents assayed by the new QAMS method could be considered as accurate as those assayed by external standard method. In addition, a method for determining applicable concentration ranges of the quantitative components assayed by QAMS method was established for the first time, which could ensure its high accuracy and could be applied to QAMS methods of other TCMs. The present study demonstrated the practicability of the application of the QAMS method for the quantitative analysis of multi

  9. Some feature of interpretation of tension single pulsed electromagnetic field of the Earth to create the model parameter fields physical properties

    Directory of Open Access Journals (Sweden)

    Mokritskaya T.P.

    2014-12-01

    Full Text Available Stochastic analysis of the results of different methods of obtaining and processing of information allows us to solve problems on a qualitatively different level. This is important when creating complex earth models and fields of its parameters, particularly the physical properties. Application of remote sensing methods (geophysical investigations with the registration of a single pulse intensity of the electromagnetic field of the Earth (EIEMPZ seismic profiling, is expanding. Interesting results of the joint interpretation of the results of geophysical and laboratory studies of physical soil. Interesting results of the joint interpretation of the results of geophysical and laboratory studies of physical soil. For the first time a methodology for assessing the state of the soil [3] applied for a joint interpretation of materials determine the field strength EMPZ, seismic profiling, and laboratory techniques. This has allowed to characterize the state of the geological environment and to build a model of inhomogeneous density distribution of fractured rocks at depth. In this paper we made a mathematical analysis of the results of research and talus deposits eluvial clay Taurian series, studied at one of the construction sites southern coast at a depth of 12.0 -25.0 m. Methods of statistical analysis, assessment of homogeneity and symmetrically distributed, rank correlation and multiple regression analysis described in [3]. The analysis of the spatial distribution of areas extrem value of EMPZ, heterogeneity of seismic rigidity. Statistical characteristics of indicators of physical properties reflect the genetic characteristics of the formation and the current state of silty-clay sediments of different genesis.It is proved that the regression model can be applied to interpret the state of the array in the construction of geodynamic model. It is established that the creation of forward-looking (dynamic models for the distribution of the physical

  10. A case study of single hygroscopicity parameter and its link to the functional groups and phase transition for urban aerosols in Taipei City

    Science.gov (United States)

    Hung, Hui-Ming; Hsu, Chia-Hung; Lin, Wei-Ting; Chen, Yu-Quan

    2016-05-01

    The hygroscopicity, functional groups and phase transitions of urban aerosol particles in Taipei City were studied using a cloud condensation nuclei counter (CCNc) with a scanning mobility particle sizer (SMPS) and an attenuated total reflectance with infrared (ATR-IR) detection technique. With the assumption of larger particles being activated first, the derived single hygroscopicity parameter (κ) exhibited an increasing trend with particle size, i.e., from 0.022 ± 0.01 at 87 ± 10 nm to 0.13 ± 0.03 at 240 ± 20 nm. The collected size-selected particles were characterized using ATR-IR for the functional groups of alkyl, carbonyl, ammonium, sulfate and nitrate, which showed various size dependence patterns, linked to different formation mechanisms. The hygroscopic response based on the ratio (xW_solute) for sample film of absorption by the enhanced water-stretching peak to that by the selected solute showed a better consistency with pure ammonium sulfate for sub-micron size particles. Based on the derived ammonium sulfate volume fraction from IR analysis, the κ received from CCNc measurements was concluded mainly contributed by ammonium sulfate for sub-micrometer particles. The increasing trend of sodium nitrate absorbance at aerosol diameter ≥1 μm was due to a reaction of nitric acid with sea salt particles. The micrometer sized particles were apparent not only in a significantly higher xW_solute than pure sodium nitrate but also had a deliquescence RH of 69 ± 1%, similar to that of sodium nitrate-sodium chloride mixtures. Overall, the organic species in this study exhibited a low hygroscopicity with less than 0.036 of contribution for the overall κ, and the major hygroscopic material of urban aerosols consisted primarily of ammonium sulfate in the sub-micrometer particles and sodium nitrate with sea salt in the coarse particles.

  11. 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

  12. Antiferromagnetic ordering states of oxygen-deficient NdBa2Cu3O6+x and Nd1+yBa2-yCu3O6+x single crystals

    DEFF Research Database (Denmark)

    Brecht, E.; Schweiss, P.; Wolf, T.

    1999-01-01

    The paper describes a study of the antiferromagnetic ordering of oxygen-deficient Nd1 + yBa2 - yCu3O6 + x single crystals. In pure, stoichiometric samples, y = 0, with different oxygen contents x in the Cu(1) plane (0.02

  13. Pt nanoparticle modified single walled carbon nanotube network electrodes for electrocatalysis: control of the specific surface area over three orders of magnitude

    NARCIS (Netherlands)

    Miller, T.S.; Sansuk, S.; Lai, Stanley; Macpherson, J.V.; Unwin, P.R.

    2015-01-01

    The electrodeposition of Pt nanoparticles (NPs) on two-dimensional single walled carbon nanotube (SWNT) network electrodes is investigated as a means of tailoring electrode surfaces with a well-defined amount of electrocatalytic material. Both Pt NP deposition and electrocatalytic studies are

  14. Magnetic ordering of Nd3+ in single-crystal NdBa2Cu3O6+¤

    DEFF Research Database (Denmark)

    Boothroyd, A.T.; Reynolds, J.M.; Andersen, N.H.

    1999-01-01

    We describe a neutron-diffraction study of the low-temperature magnetic ordering in single crystals of NdBa2Cu3O6+x. We investigated a superconducting crystal (T-c=95.5 K), and two nonsuperconducting crystals (x approximate to 0.1). The two nonsuperconducting crystals differed in their Cu...... arrangements of the Nd moments refined from the diffraction intensities agree broadly with those deduced previously from neutron powder diffraction studies, but differ in some of the details......., but in crystal B the Nd ordering was of very short range in the c direction. The onset of Nd ordering produced no detectable changes in the: CU ordering in the nonsuperconducting crystals, and from this we place an upper limit of 0.05 meV on the strength of any Nd-Cu pseudodipolar magnetic coupling. The ordered...

  15. Structural parameters of dimethyl sulfoxide, DMSO, at 100 K, based on a redetermination by use of high-quality single-crystal X-ray data.

    Science.gov (United States)

    Reuter, Hans

    2017-10-01

    The title compound, C 2 H 6 OS, is a high melting, polar and aprotic solvent widely used in organic and inorganic chemistry. It serves as a H-atom acceptor in hydrogen bonding and is used as an ambidentate ligand in coordination chemistry. The evaluation of the influence of inter-molecular inter-actions on the inter-nal structural parameters of the chemically bonded DMSO mol-ecules affords precise structural data of the free mol-ecule as a point of reference. So far, valid data have been obtained only by use of neutron powder diffraction [Ibberson (2005 ▸). Acta Cryst. C 61 , o571-o573]. In the present redetermination, structural data have been obtained from a single-crystal X-ray diffraction experiment at 100 K, revealing a better comparison with DMSO mol-ecules in other crystal structures. In the solid state, the pyramidal mol-ecule exhibits a nearly perfect C s symmetry [including H atoms, which are eclipsed with respect to the C⋯C axis], with a C-S-C bond angle of 97.73 (7)° and an S-O bond length of 1.5040 (10) Å, corresponding very well with an S=O double bond, and with almost equal S-C bond lengths [mean value = 1.783 (4) Å] and O-S-C bond angles [mean value = 106.57 (4)°]. The crystal packing is influenced by C-H⋯O inter-actions (2.42-2.47 Å) between all three H atoms of only one methyl group with the O atoms of three neighbouring DMSO mol-ecules. The inter-actions of the O atom with H atoms (or Lewis acids, or hydrogen-donor groups) of adjacent mol-ecules in relation to the orientation of the complete DMSO mol-ecule are described in terms of the angle ω and the distance d norm ; ω is the angle between the pseudo-mirror plane of the mol-ecule and the plane defined through the S=O bond and the inter-acting atom, and d norm is the distance of the inter-acting atom from the plane perpendicular to the S=O bond.

  16. Structural parameters of dimethyl sulfoxide, DMSO, at 100 K, based on a redetermination by use of high-quality single-crystal X-ray data

    Directory of Open Access Journals (Sweden)

    Hans Reuter

    2017-10-01

    Full Text Available The title compound, C2H6OS, is a high melting, polar and aprotic solvent widely used in organic and inorganic chemistry. It serves as a H-atom acceptor in hydrogen bonding and is used as an ambidentate ligand in coordination chemistry. The evaluation of the influence of intermolecular interactions on the internal structural parameters of the chemically bonded DMSO molecules affords precise structural data of the free molecule as a point of reference. So far, valid data have been obtained only by use of neutron powder diffraction [Ibberson (2005. Acta Cryst. C61, o571–o573]. In the present redetermination, structural data have been obtained from a single-crystal X-ray diffraction experiment at 100 K, revealing a better comparison with DMSO molecules in other crystal structures. In the solid state, the pyramidal molecule exhibits a nearly perfect Cs symmetry [including H atoms, which are eclipsed with respect to the C...C axis], with a C—S—C bond angle of 97.73 (7° and an S—O bond length of 1.5040 (10 Å, corresponding very well with an S=O double bond, and with almost equal S—C bond lengths [mean value = 1.783 (4 Å] and O—S—C bond angles [mean value = 106.57 (4°]. The crystal packing is influenced by C—H...O interactions (2.42–2.47 Å between all three H atoms of only one methyl group with the O atoms of three neighbouring DMSO molecules. The interactions of the O atom with H atoms (or Lewis acids, or hydrogen-donor groups of adjacent molecules in relation to the orientation of the complete DMSO molecule are described in terms of the angle ω and the distance dnorm; ω is the angle between the pseudo-mirror plane of the molecule and the plane defined through the S=O bond and the interacting atom, and dnorm is the distance of the interacting atom from the plane perpendicular to the S=O bond.

  17. 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

  18. Conferring of contracts by utilities in the Single European Market. Transposition of the sectoral directive where it concerns construction and delivery orders into German law

    International Nuclear Information System (INIS)

    Pick, H.; Wetzel, U.

    1994-01-01

    After the enactment of the Second Law Amending the Law on Budgetary Principles, the Ordinance on the Confering of Contracts, and the Ordinance on Verification; and the amendment of the ordinances on the placing of construction and delivery orders (VOB and VOL) the European Directives on so-called ''public'' tendering can be said to be transposed into German law as far as they concern construction and delivery orders. This means that as of 1 March 1994 besides the ''classical'' public contractors utilities, too, must invite bids Europe-wide. According to European law this also applies to service orders as of 1 July 1994, but this provision still awaits transposition into German law. (orig.) [de

  19. Effects of magnetic order on the superconducting length scales and critical fields in single crystal ErNi2B2C

    DEFF Research Database (Denmark)

    Gammel, P.L.; Barber, B.P.; Ramirez, A.P.

    1999-01-01

    The flux line form factor in small angle neutron scattering and transport data determines the superconducting length scares and critical fields in single crystal ErNi2B2C. For H parallel to c, the coherence length xi increases and the penetration depth lambda decreases when crossing T-N = 6.0 K......, the Neel transition. The critical fields show corresponding anomalies near T-N. For H perpendicular to c, the fourfold modulation of the upper critical field H-c2 is strongly temperature dependent, changing sign near T-N, and can be modeled using the anisotropy of the sublattice magnetization....

  20. Monolithic integration of InGaN segments emitting in the blue, green, and red spectral range in single ordered nanocolumns

    Energy Technology Data Exchange (ETDEWEB)

    Albert, S.; Bengoechea-Encabo, A.; Sanchez-Garcia, M. A.; Calleja, E. [ISOM and Dept. Ingenieria Electronica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Kong, X.; Trampert, A. [Paul-Drude-Institut fuer Festkoeperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2013-05-06

    This work reports on the selective area growth by plasma-assisted molecular beam epitaxy and characterization of InGaN/GaN nanocolumnar heterostructures. The optimization of the In/Ga and total III/V ratios, as well as the growth temperature, provides control on the emission wavelength, either in the blue, green, or red spectral range. An adequate structure tailoring and monolithic integration in a single nanocolumnar heterostructure of three InGaN portions emitting in the red-green-blue colors lead to white light emission.

  1. Stacking faults and microstructural parameters in non-mulberry silk ...

    Indian Academy of Sciences (India)

    order method is a reasonably good approach to obtain microstructural parameters [13]. Keijser et al [14] have also suggested a single-order method employing Voigt function and integral breadth of reflections. For silk fibres and for most of the other ...

  2. 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.

  3. Multifunctional Bi{sub 2}ZnOB{sub 2}O{sub 6} single crystals for second and third order nonlinear optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Iliopoulos, K. [LUNAM Université, Université d' Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex (France); Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), 26504 Patras (Greece); Kasprowicz, D. [Faculty of Technical Physics, Poznan University of Technology, Nieszawska 13 A, 60-965 Poznan (Poland); Majchrowski, A. [Institute of Applied Physics, Military University of Technology, Kaliskiego 2, 00-908 Warszawa (Poland); Michalski, E. [Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warszawa (Poland); Gindre, D.; Sahraoui, B., E-mail: bouchta.sahraoui@univ-angers.fr [LUNAM Université, Université d' Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex (France)

    2013-12-02

    Bi{sub 2}ZnOB{sub 2}O{sub 6} nonlinear optical single crystals were grown by means of the Kyropoulos method from stoichiometric melt. The second and third harmonic generation (SHG/THG) of Bi{sub 2}ZnOB{sub 2}O{sub 6} crystals were investigated by the SHG/THG Maker fringes technique. Moreover, SHG microscopy studies were carried out providing two-dimensional SHG images as a function of the incident laser polarization. The high nonlinear optical efficiency combined with the possibility to grow high quality crystals make Bi{sub 2}ZnOB{sub 2}O{sub 6} an excellent candidate for photonic applications.

  4. Single hadron spectrum in γγ collisions: The QCD contribution to order αsub(s) and the non perturbative background

    International Nuclear Information System (INIS)

    Aurenche, P.; Douiri, A.; Baier, R.; Fontannaz, M.; Schiff, D.

    1985-01-01

    We calculate the corrections of order αsub(s) to the process γγ->HX where both initial photons are real. The analytic expressions are given and a detailed discussion of the variation of the corrections with psub(T) and rapidity is presented. The dependence on the factorization prescription and scale is also discussed. Using the equivalent photon approximation the cross-section for e + e - ->e + e - HX is calculated both in the PEP/PETRA and LEP energy range. Based on the vector meson dominance model the non perturbative background is estimated and its importance for present and future experiments is emphasized. (orig.)

  5. Generalizing the bra state in the symmetry-adapted cluster singles and doubles method and the second-order perturbation correction

    Science.gov (United States)

    Hasegawa, Jun-ya; Obata, Akihiro; Matsuda, Kenji

    2010-02-01

    We present a procedure to overcome the quasi-degeneracy problem in the CCSD and SACSD methods. A multi-configuration bra state in the SACSD equations (MRbra-SACSD equation) together with a second-order perturbation correction gives quantitatively correct potential curves for bond dissociations. The benchmark results for HF, F 2, and H 2O show that the perturbative triple correction reduces the deviations from Full-CI energies to within 3 mHartree (1.9 kcal/mol). Within the benchmark calculations, the results of the present method are comparable with the recent post-CCSD corrections, the CR-CCSD(T) and CCSD(2) T methods, and are slightly less accurate than the CR-CC(2,3) method.

  6. Comparison of high-order-harmonic generation on single-layer graphene flakes with armchair and zigzag types in an intense laser field

    Science.gov (United States)

    Guo, Jing; Zhong, Huiying; Yan, Bing; Chen, Yi; Jiang, Yuanfei; Wang, Ting-feng; Shao, Jun-feng; Zheng, Chang-bin; Liu, Xue-Shen

    2016-03-01

    The high-order-harmonic generation (HHG) of graphene in an intense laser field is investigated using the strong-field approximation method. The initial wave function is presented by gaussian and gamess software. The molecular structure along the x and y axes represents different types of graphene: armchair and zigzag, respectively. The results show that the HHG intensity of the armchair type of graphene is two magnitudes higher than that of the zigzag type in the plateau area. The ionization yield and electron density distribution are also presented to further explain this difference. Finally, by superposing a properly selected range of harmonics, a main pulse with the duration of 91 and 99 attoseconds accompanied by weak satellite pulses will be generated for the case of armchair and zigzag graphene, respectively, and the corresponding intensity from armchair graphene is much higher than that from zigzag graphene.

  7. Fast recognition of single molecules based on single-event photon statistics

    International Nuclear Information System (INIS)

    Dong Shuangli; Huang Tao; Liu Yuan; Wang Jun; Zhang Guofeng; Xiao Liantuan; Jia Suotang

    2007-01-01

    Mandel's Q parameter, which is determined from single-event photon statistics, provides an alternative way to recognize single molecules with fluorescence detection, other than the second-order correlation function. It is shown that the Q parameter of an assumed ideal double-molecule fluorescence with the same average photon number as that of the sample fluorescence can act as the criterion for single-molecule recognition. The influence of signal-to-background ratio and the error estimates for photon statistics are also presented. We have applied this method to ascertain single Cy5 dye molecules within hundreds of milliseconds

  8. Optimization of Initial Parameters and Fuel Afterburning Ratio in Heat-Recovery Boiler of Single- and Two-Loop Combined-Cycle Plant

    Directory of Open Access Journals (Sweden)

    B. V. Yakovlev

    2007-01-01

    Full Text Available An analysis of influence of initial parameters and fuel afterburning ratio on efficiency of sin­gle- and two-loop combined-cycle plant has been done in the paper.The paper contains fundamentals of combined-cycle plants initial parameters’ optimization and examples for the sets with gas turbines of various efficiency.

  9. A variable temperature EPR study of Mn(2+)-doped NH(4)Cl(0.9)I(0.1) single crystal at 170 GHz: zero-field splitting parameter and its absolute sign.

    Science.gov (United States)

    Misra, Sushil K; Andronenko, Serguei I; Chand, Prem; Earle, Keith A; Paschenko, Sergei V; Freed, Jack H

    2005-06-01

    EPR measurements have been carried out on a single crystal of Mn(2+)-doped NH(4)Cl(0.9)I(0.1) at 170-GHz in the temperature range of 312-4.2K. The spectra have been analyzed (i) to estimate the spin-Hamiltonian parameters; (ii) to study the temperature variation of the zero-field splitting (ZFS) parameter; (iii) to confirm the negative absolute sign of the ZFS parameter unequivocally from the temperature-dependent relative intensities of hyperfine sextets at temperatures below 10K; and (iv) to detect the occurrence of a structural phase transition at 4.35K from the change in the structure of the EPR lines with temperature below 10K.

  10. Effects of aortic tortuosity on left ventricular diastolic parameters derived from gated myocardial perfusion single photon emission computed tomography in patients with normal myocardial perfusion.

    Science.gov (United States)

    Kurisu, Satoshi; Nitta, Kazuhiro; Sumimoto, Yoji; Ikenaga, Hiroki; Ishibashi, Ken; Fukuda, Yukihiro; Kihara, Yasuki

    2017-12-05

    Aortic tortuosity is often found on chest radiograph, especially in aged patients. We tested the hypothesis that aortic tortuosity was associated with LV diastolic parameters derived from gated SPECT in patients with normal myocardial perfusion. One-hundred and twenty-two patients with preserved LV ejection fraction and normal myocardial perfusion were enrolled. Descending aortic deviation was defined as the horizontal distance from the left line of the aortic knob to the most prominent left line of the descending aorta. This parameter was measured for the quantitative assessment of aortic tortuosity. Peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained from redistribution images as LV diastolic parameters. Descending aortic deviation ranged from 0 to 22 mm with a mean distance of 4.5 ± 6.3 mm. Descending aortic deviation was significantly correlated with age (r = 0.38, p < 0.001) and estimated glomerular filtration rate (eGFR) (r = - 0.21, p = 0.02). Multivariate linear regression analysis revealed that eGFR (β = 0.23, p = 0.02) and descending aortic deviation (β = - 0.23, p = 0.01) were significantly associated with PFR, and that only descending aortic deviation (β = - 0.21, p = 0.03) was significantly associated with 1/3 MFR. Our data suggest that aortic tortuosity is associated with LV diastolic parameters derived from gated SPECT in patients with normal myocardial perfusion.

  11. 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...

  12. Multi objective optimization of performance parameters of a single cylinder diesel engine running with hydrogen using a Taguchi-fuzzy based approach

    International Nuclear Information System (INIS)

    Bose, Probir Kumar; Deb, Madhujit; Banerjee, Rahul; Majumder, Arindam

    2013-01-01

    Environmental issues and rapid exhaustion of fossil fuels are the major concerns over the past two decades to search for alternative fuels. Among various alternatives hydrogen is a long-term renewable and least polluting fuel. Its clean burning capability helps to meet the stern emission norms. Full substitution of diesel with hydrogen may not be convenient for the time being but employing of hydrogen in a diesel engine in dual fuel mode is possible. In this experimental investigation a TMI (timed manifold injection) system has been developed using ECU (electronic control unit) with varying injection strategy to deliver hydrogen on to the intake manifold. Through adopting this technique in the existing diesel engine a momentous improvement in performance and combustion parameters has been observed. The study also attempts to explain the application of the fuzzy logic based Taguchi analysis to optimize the performance parameters i.e. BSEC (Brake specific energy consumption), Vol. Eff. (Volumetric efficiency) and BTHE (brake thermal efficiency) for the different hydrogen injection strategies. - Highlights: • A timed manifold injection system has been developed which enhances the BTHE by 31.74% at full load conditions. • Use of hydrogen-diesel dual fuel of BSEC was reduced by a maximum of 68.98% at full load condition compared to diesel. • Τhe Vol. Eff. reduced by 73.14% in dual fuel mode as compared to 77.23% at full load condition with base diesel. • A fuzzy based Taguchi's parameter design technique has been involved in multi objective optimization for prediction. • Predicted optimum combination improved BTHE and Vol. Eff. by 24.04% and 72.87% respectively and reduced BSEC by 59.03%

  13. Factors affecting insulin resistance and its relation to Vitamin D status and clinical nutritional parameters in dialysis patients: A single-center Indian study

    Directory of Open Access Journals (Sweden)

    R Jhorawat

    2018-01-01

    Full Text Available The aim of this study was to measure insulin resistance (IR in dialysis patients and its relation to Vitamin D status and nutritional parameters. We included patients on maintenance dialysis, both hemodialysis and peritoneal dialysis (HD and PD. IR was measured by homeostatic model assessment (HOMA-IR index defined as fasting serum insulin (μU/L × fasting blood sugar (mmol/L/22.5. Baseline Vitamin D levels were measured by chemiluminescence immunoassay (CLIA method. HOMA-IR index correlated with nutritional parameters such as 7-point subjective global assessment (SGA and anthropometric measures, for example, body fat percentage, lean body weight (LBW, mid-arm circumference (MAC, and mid-arm muscle circumference (MAMC. A total of 55 patients were studied, of them 74.55% were male with mean age of the study population being 37.44 ± 14.96 years. The prevalence values of Vitamin D deficiency 20 ng/ml, i.e., 3.74 ± 4.37 and 1.67 ± 1.47, respectively (P = 0.018. The other measured parameter which had a significant positive correlation with IR was serum uric acid (r = 0.303, 95% CI = 0.021–0.534, and P = 0.025. In nutritional assessment, body mass index, MAC, and MAMC had statistically significant positive correlation with HOMA-IR index (P ≤ 0.001, 0.004, and 0.004, respectively unlike SGA (P = 0.480. The mode of dialysis did not have a significant effect on IR (HD vs. PD, P = 0.227. The majority of the patients on maintenance dialysis are Vitamin D deficient. Low Vitamin D level, especially <20 ng/ml, muscle mass, and high serum uric acid level are likely to have more IR in dialysis-dependent patients.

  14. Factors Affecting Insulin Resistance and Its Relation to Vitamin D Status and Clinical Nutritional Parameters in Dialysis Patients: A Single-center Indian Study

    Science.gov (United States)

    Jhorawat, R.; Bansal, N.; Beniwal, P.; Agarwal, D.; Malhotra, V.

    2018-01-01

    The aim of this study was to measure insulin resistance (IR) in dialysis patients and its relation to Vitamin D status and nutritional parameters. We included patients on maintenance dialysis, both hemodialysis and peritoneal dialysis (HD and PD). IR was measured by homeostatic model assessment (HOMA)-IR index defined as fasting serum insulin (μU/L) × fasting blood sugar (mmol/L)/22.5. Baseline Vitamin D levels were measured by chemiluminescence immunoassay (CLIA) method. HOMA-IR index correlated with nutritional parameters such as 7-point subjective global assessment (SGA) and anthropometric measures, for example, body fat percentage, lean body weight (LBW), mid-arm circumference (MAC), and mid-arm muscle circumference (MAMC). A total of 55 patients were studied, of them 74.55% were male with mean age of the study population being 37.44 ± 14.96 years. The prevalence values of Vitamin D deficiency 20 ng/ml, i.e., 3.74 ± 4.37 and 1.67 ± 1.47, respectively (P = 0.018). The other measured parameter which had a significant positive correlation with IR was serum uric acid (r = 0.303, 95% CI = 0.021–0.534, and P = 0.025). In nutritional assessment, body mass index, MAC, and MAMC had statistically significant positive correlation with HOMA-IR index (P ≤ 0.001, 0.004, and 0.004, respectively) unlike SGA (P = 0.480). The mode of dialysis did not have a significant effect on IR (HD vs. PD, P = 0.227). The majority of the patients on maintenance dialysis are Vitamin D deficient. Low Vitamin D level, especially <20 ng/ml, muscle mass, and high serum uric acid level are likely to have more IR in dialysis-dependent patients. PMID:29515300

  15. Can the Responses of Photosynthesis and Stomatal Conductance to Water and Nitrogen Stress Combinations Be Modeled Using a Single Set of Parameters?

    Science.gov (United States)

    Zhang, Ningyi; Li, Gang; Yu, Shanxiang; An, Dongsheng; Sun, Qian; Luo, Weihong; Yin, Xinyou

    2017-01-01

    Accurately predicting photosynthesis in response to water and nitrogen stress is the first step toward predicting crop growth, yield and many quality traits under fluctuating environmental conditions. While mechanistic models are capable of predicting photosynthesis under fluctuating environmental conditions, simplifying the parameterization procedure is important toward a wide range of model applications. In this study, the biochemical photosynthesis model of Farquhar, von Caemmerer and Berry (the FvCB model) and the stomatal conductance model of Ball, Woodrow and Berry which was revised by Leuning and Yin (the BWB-Leuning-Yin model) were parameterized for Lilium (L. auratum × speciosum “Sorbonne”) grown under different water and nitrogen conditions. Linear relationships were found between biochemical parameters of the FvCB model and leaf nitrogen content per unit leaf area (Na), and between mesophyll conductance and Na under different water and nitrogen conditions. By incorporating these Na-dependent linear relationships, the FvCB model was able to predict the net photosynthetic rate (An) in response to all water and nitrogen conditions. In contrast, stomatal conductance (gs) can be accurately predicted if parameters in the BWB-Leuning-Yin model were adjusted specifically to water conditions; otherwise gs was underestimated by 9% under well-watered conditions and was overestimated by 13% under water-deficit conditions. However, the 13% overestimation of gs under water-deficit conditions led to only 9% overestimation of An by the coupled FvCB and BWB-Leuning-Yin model whereas the 9% underestimation of gs under well-watered conditions affected little the prediction of An. Our results indicate that to accurately predict An and gs under different water and nitrogen conditions, only a few parameters in the BWB-Leuning-Yin model need to be adjusted according to water conditions whereas all other parameters are either conservative or can be adjusted according to

  16. Electrophysiological approach to determine kinetic parameters of sucrose uptake by single sieve elements or phloem parenchyma cells in intact Vicia faba plants.

    Science.gov (United States)

    Hafke, Jens B; Höll, Sabina-Roxana; Kühn, Christina; van Bel, Aart J E

    2013-01-01

    Apart from cut aphid stylets in combination with electrophysiology, no attempts have been made thus far to measure in vivo sucrose-uptake properties of sieve elements. We investigated the kinetics of sucrose uptake by single sieve elements and phloem parenchyma cells in Vicia faba plants. To this end, microelectrodes were inserted into free-lying phloem cells in the main vein of the youngest fully-expanded leaf, half-way along the stem, in the transition zone between the autotrophic and heterotrophic part of the stem, and in the root axis. A top-to-bottom membrane potential gradient of sieve elements was observed along the stem (-130 mV to -110 mV), while the membrane potential of the phloem parenchyma cells was stable (approx. -100 mV). In roots, the membrane potential of sieve elements dropped abruptly to -55 mV. Bathing solutions having various sucrose concentrations were administered and sucrose/H(+)-induced depolarizations were recorded. Data analysis by non-linear least-square data fittings as well as by linear Eadie-Hofstee (EH) -transformations pointed at biphasic Michaelis-Menten kinetics (2 MM, EH: K m1 1.2-1.8 mM, K m2 6.6-9.0 mM) of sucrose uptake by sieve elements. However, Akaike's Information Criterion (AIC) favored single MM kinetics. Using single MM as the best-fitting model, K m values for sucrose uptake by sieve elements decreased along the plant axis from 1 to 7 mM. For phloem parenchyma cells, higher K m values (EH: K m1 10 mM, K m2 70 mM) as compared to sieve elements were found. In preliminary patch-clamp experiments with sieve-element protoplasts, small sucrose-coupled proton currents (-0.1 to -0.3 pA/pF) were detected in the whole-cell mode. In conclusion (a) K m values for sucrose uptake measured by electrophysiology are similar to those obtained with heterologous systems, (b) electrophysiology provides a useful tool for in situ determination of K m values, (c) As yet, it remains unclear if one or two uptake systems are involved in sucrose

  17. Neutron-scattering determination of the structural parameters versus oxygen content of YBa2Cu3O6+x single crystals

    DEFF Research Database (Denmark)

    Casalta, H.; Schleger, P.; Harris, P.

    1996-01-01

    The crystal structure of high-quality single crystals of YBa2Cu3O6+x grown in zirconia crucibles was studied systematically versus oxygen concentration by four-circle neutron diffraction at room temperature, The oxygen contents ranged from x = 0.18 (insulating, tetragonal phase) to x = 0....... Also, there is neither an abrupt change of the apical-oxygen position at the orthorhombic to tetragonal transition, nor is there any indication of depletion of the atomic sites except for the chain-site oxygen, The superconducting critical temperatures or Neel temperatures, as well as the existence...

  18. The Role of Large-Format Histopathology in Assessing Subgross Morphological Prognostic Parameters: A Single Institution Report of 1000 Consecutive Breast Cancer Cases

    Directory of Open Access Journals (Sweden)

    Tibor Tot

    2012-01-01

    Full Text Available Breast cancer subgross morphological parameters (disease extent, lesion distribution, and tumor size provide significant prognostic information and guide therapeutic decisions. Modern multimodality radiological imaging can determine these parameters with increasing accuracy in most patients. Large-format histopathology preserves the spatial relationship of the tumor components and their relationship to the resection margins and has clear advantages over traditional routine pathology techniques. We report a series of 1000 consecutive breast cancer cases worked up with large-format histology with detailed radiological-pathological correlation. We confirmed that breast carcinomas often exhibit complex subgross morphology in both early and advanced stages. Half of the cases were extensive tumors and occupied a tissue space ≥40 mm in its largest dimension. Because both in situ and invasive tumor components may exhibit unifocal, multifocal, and diffuse lesion distribution, 17 different breast cancer growth patterns can be observed. Combining in situ and invasive tumor components, most cases fall into three aggregate growth patterns: unifocal (36%, multifocal (35%, and diffuse (28%. Large-format histology categories of tumor size and disease extent were concordant with radiological measurements in approximately 80% of the cases. Noncalcified, low-grade in situ foci, and invasive tumor foci <5 mm were the most frequent causes of discrepant findings.

  19. Single and Combined Impacts of Vitamin A and Selenium in Diet on Productive Performance, Egg Quality, and Some Blood Parameters of Laying Hens During Hot Season.

    Science.gov (United States)

    Abd El-Hack, Mohamed E; Mahrose, Khalid; Askar, Ali A; Alagawany, Mahmoud; Arif, Muhammad; Saeed, Muhammad; Abbasi, Farzana; Soomro, Rab Nawaz; Siyal, Farman Ali; Chaudhry, Maria Tabassum

    2017-05-01

    A study was conducted using 162 Bovans laying hens to investigate the impacts of extra dietary vitamin A (0, 8000, 16,000 IU/kg), selenium (0, 0.25, 0.50 mg/kg), and their combinations on the performance, egg quality, and blood biological parameters of laying hens during summer months. Supplemental vitamin A up to 16,000 IU/kg diet significantly (P feed intake which increased with 8000 IU/kg diet compared with control. Feed intake and feed conversion of hens fed diet supplemented with selenium revealed high statistical (P = 0.001) differences. All egg quality criteria were not significantly (P hens reared under heat stress conditions.

  20. Single nucleotide polymorphisms in sFRP4 are associated with bone and body composition related parameters in Danish but not in Belgian men

    DEFF Research Database (Denmark)

    Boudin, Eveline; Piters, Elke; Nielsen, Torben Leo

    2012-01-01

    ) in a decrease in bone density and bone strength. Finally, we observed in the Danish population age specific associations with height and fat mass. In the Belgian population we tried to replicate the results of three SNPs with BMD and body composition parameters. Unfortunately, we were not able to replicate......The senescence accelerated mouse P6 (SAMP6) has a low bone mass and has previously shown to be a good model for senile osteoporosis in humans. In addition to a reduced bone mass, SAMP6 mice are obese and have hyperlipidemia. Using positional cloning and expression studies, an increased expression...... of sfrp4 was found in these mice. SFRP4 is a modulator of the Wnt signalling pathway. This pathway has been previously shown to be involved in regulating bone mass. Additional evidence that sFRP4 has an influence on BMD was delivered by linkage and association studies mostly performed in Asian populations...

  1. Excess Weight Loss and Cardiometabolic Parameter Reduction Diminished among Hispanics Undergoing Bariatric Surgery: Outcomes in More than 2,000 Consecutive Hispanic Patients at a Single Institution.

    Science.gov (United States)

    Serrano, Oscar K; Zhang, Yang; Cumella, Lindsay; Kintzer, Emily; Ng, Nicole; Sandoval, Eduardo; Choi, Jenny; Melvin, W Scott; Camacho, Diego R

    2016-02-01

    Bariatric surgery has been established as the most effective long-term treatment for morbid obesity and obesity-related comorbidities. Despite its success, there is a paucity of data on the outcomes of bariatric surgery on Hispanic patients. We performed a retrospective review of obese patients treated at our institute between 2008 and 2014. We identified self-reported Hispanic patients who underwent a laparoscopic gastric bypass (LGBP), sleeve gastrectomy (LSG), or gastric band (LGB) procedure. The primary end point was excess weight loss (EWL) at 6, 12, 24, and 36 months. Secondary end points included improvement of obesity-related metabolic parameters at 1 year. We performed a repeated measures analysis of variance to calculate statistical significance throughout our study time period. We identified 2002 Hispanic patients who underwent bariatric surgery (1,235 LGBP, 600 LSG, 167 LGB) at our institute from 2008 to 2014. Follow-ups at 6, 12, 24, and 36 months were 62.2%, 54.5%, 36.2%, and 19.8%, respectively. Mean preoperative BMIs were 47.0 ± 7.2 kg/m2, 46.1 ± 7.8 kg/m2, and 44.9 ± 6.0 kg/m2 for the LGBP, LSG, and LGB cohorts, respectively. Excess weight loss was significantly more pronounced in the LGBP and the LSG groups than in the LGB group; this difference was accentuated over time (p Bariatric surgery is highly successful in Hispanic obese patients. In the largest series to date, LGBP and LSG seem to yield more effective EWL and reduction of cardiometabolic parameters than LGB among Hispanics; however, outcomes are still markedly reduced when compared with those in non-Hispanic populations. Copyright © 2016. Published by Elsevier Inc.

  2. Real-time monitoring of longitudinal electron bunch parameters by intensity-integrated and spectroscopic measurements of single coherent THz pulses

    International Nuclear Information System (INIS)

    Wesch, Stephan

    2012-12-01

    High-gain free-electron lasers (FELs) generate intense and monochromatic photon pulses with few tens of femtosecond duration. For this purpose, electron beams are accelerated to relativistic energies and shrunk longitudinally down to micrometer size.The diagnosis of theses compressed electron bunches is a challenge especially for MHz bunch repetition rates as provided by the FEL FLASH in Hamburg. In this thesis, coherently emitted THz radiation of single electron bunches were investigated, on which the longitudinal structure is imprinted. Two instruments were used: First, the FLASH bunch compression monitors, relying on the integrated intensity measurement of diffraction radiation, were modified to determine the overall length of every bunch behind the two bunch compressors (BC). A model was developed showing that their response is independent of the exact bunch shape for lengths below 200 μm (rms). This could experimentally be verified in the range between 50 and 190 μm within 7% accuracy for themonitor behind the last BC by comparison with measurements with the transverse deflecting structure (TDS). Second, a single-shot spectrometer with five staged reflective blazed gratings has been designed, build and commissioned. With its two grating sets, the wavelength ranges from 5.5 to 44 μm and 45 to 440 μm can be simultaneously detected by 118 fast pyroelectric elements. Measurements based on transition radiation spectra were compared with profiles recorded by the TDS.The shape of the spectra as well as the reconstructed temporal profiles (using the Kramers-Kronig relation for phase retrieval) are in excellent agreement. For bunches with a charge of 50 pC, bunch lengths down to 5 μm (fhwm) could be detected.

  3. How to do identify single cases according to the quality assurance from IOFOS. The positive identification of an unidentified body by dental parameters: a case of homicide.

    Science.gov (United States)

    Pereira, Cristiana Palmela; Santos, Jorge Costa

    2013-04-01

    The positive identification of skeletal by individual dental parameters is one of the objectives of the criminal investigation. The intervention of Forensic Dentistry in some circumstances may represent the only way to obtaining a positive identification of an unidentified bodies. The teeth constitute a scientific method in forensic identification, principally due to the great resistance to the agents who provoke the destruction of the soft tissues in the corpses (putrefaction, traumatic, physical and chemical agents) and to the high morphological variability of the human teeth. The human identification in Forensic Dentistry is made by two ways: comparative and reconstructive. The identification allows to determine several parameters of forensic interest: specimen, population affinity, sex, age, stature and individualization's factors. The Forensic Dentistry is one of the most important fields in individual identification, because teeth have less variability in the chronology of events in terms of the reconstructive way. On the other side, in terms of the comparative way, this area is also important, because of the individualization's factors: positive identification in individual cases and in mass disasters. In this forensic case report, a homicide case, the objective of the medico-legal investigation was a positive identification of the unidentified corpse found one year after the crime, July 2010. The Portuguese Criminal Police of Lisbon, Homicide Group, requested to South Branch of the Portuguese National Institute of Forensic Medicine, a forensic examination by a Forensic Odontologist for dental positive identification. The objectives were: 1) post mortem reconstruction of the dental status of the victim; 2) obtain the ante mortem information of the presumable victims; 3) comparison of the post mortem information with the ante mortem information, for a positive identification of the presumable homicide victim. in this field of dental investigation, the

  4. Optimization of mass spectrometric parameters improve the identification performance of capillary zone electrophoresis for single-shot bottom-up proteomics analysis.

    Science.gov (United States)

    Zhang, Zhenbin; Dovichi, Norman J

    2018-02-25

    The effects of MS1 injection time, MS2 injection time, dynamic exclusion time, intensity threshold, and isolation width were investigated on the numbers of peptide and protein identifications for single-shot bottom-up proteomics analysis using CZE-MS/MS analysis of a Xenopus laevis tryptic digest. An electrokinetically pumped nanospray interface was used to couple a linear-polyacrylamide coated capillary to a Q Exactive HF mass spectrometer. A sensitive method that used a 1.4 Th isolation width, 60,000 MS2 resolution, 110 ms MS2 injection time, and a top 7 fragmentation produced the largest number of identifications when the CZE loading amount was less than 100 ng. A programmable autogain control method (pAGC) that used a 1.4 Th isolation width, 15,000 MS2 resolution, 110 ms MS2 injection time, and top 10 fragmentation produced the largest number of identifications for CZE loading amounts greater than 100 ng; 7218 unique peptides and 1653 protein groups were identified from 200 ng by using the pAGC method. The effect of mass spectrometer conditions on the performance of UPLC-MS/MS was also investigated. A fast method that used a 1.4 Th isolation width, 30,000 MS2 resolution, 45 ms MS2 injection time, and top 12 fragmentation produced the largest number of identifications for 200 ng UPLC loading amount (6025 unique peptides and 1501 protein groups). This is the first report where the identification number for CZE surpasses that of the UPLC at the 200 ng loading level. However, more peptides (11476) and protein groups (2378) were identified by using UPLC-MS/MS when the sample loading amount was increased to 2 μg with the fast method. To exploit the fast scan speed of the Q-Exactive HF mass spectrometer, higher sample loading amounts are required for single-shot bottom-up proteomics analysis using CZE-MS/MS. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Systemic distribution of single-walled carbon nanotubes in a novel model: alteration of biochemical parameters, metabolic functions, liver accumulation, and inflammation in vivo

    Directory of Open Access Journals (Sweden)

    Principi E

    2016-09-01

    Full Text Available Elisa Principi,1,* Rossana Girardello,2,* Antonino Bruno,1,* Isabella Manni,3 Elisabetta Gini,2 Arianna Pagani,1 Annalisa Grimaldi,2 Federico Ivaldi,4 Terenzio Congiu,5 Daniela De Stefano,1 Giulia Piaggio,3 Magda de Eguileor,2 Douglas M Noonan,1,2 Adriana Albini1 1Vascular Biology and Angiogenesis, Scientific and Technology Pole, IRCCS MultiMedica, Milano, 2Department of Biotechnology and Life Sciences, University of Insubria, Varese, 3Department of Research, Advanced Diagnosis and Innovation, Regina Elena National Cancer Institute, Rome, 4Department of Neuroscience, Ophthalmology and Genetics, University of Genoa, Genoa, 5Department of Surgical and Morphological Sciences, University of Insubria, Varese, Italy *These authors contributed equally to this work Abstract: The increasing use of carbon nanotubes (CNTs in several industrial applications raises concerns on their potential toxicity due to factors such as tissue penetrance, small dimensions, and biopersistence. Using an in vivo model for CNT environmental exposure, mimicking CNT exposition at the workplace, we previously found that CNTs rapidly enter and disseminate in the organism, initially accumulating in the lungs and brain and later reaching the liver and kidneys via the bloodstream in CD1 mice. Here, we monitored and traced the accumulation of single-walled CNTs (SWCNTs, administered systemically in mice, in different organs and the subsequent biological responses. Using the novel in vivo model, MITO-Luc bioluminescence reporter mice, we found that SWCNTs induce systemic cell proliferation, indicating a dynamic response of cells of both bone marrow and the immune system. We then examined metabolic (water/food consumption and dejections, functional (serum enzymes, and morphological (organs and tissues alterations in CD1 mice treated with SWCNTs, using metabolic cages, performing serum analyses, and applying histological, immunohistochemical, and ultrastructural (transmission electron

  6. 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.

  7. The Impact of Patient Education on Anthropometric, Lipidemic, and Glycemic Parameters Among Patients With Poorly Controlled Type II Diabetes Mellitus: A 3-Month Prospective Single-Center Turkish Study.

    Science.gov (United States)

    Cander, Soner; Gul, Ozen Oz; Gul, Cuma B; Keles, Saadet B; Yavas, Sibel; Ersoy, Canan

    2014-12-01

    This study evaluated the impact of patient education on adherence to a diabetes care plan (e.g., anthropometric, lipidemic, and glycemic parameters) among adults with type II diabetes mellitus without adequate glycemic control. A total of 61 ambulatory adults with type II diabetes mellitus (mean age: 53.6 ± 8.2 years, 70.5% female) were evaluated for anthropometrics, duration of diabetes mellitus, type of anti-diabetic treatment, blood biochemistry, and glycemic parameters in this 3-month prospective observational single-center study. During the course of the study, participants demonstrated a significant decrease in body weight and fat percentage and HbA1c (p diabetes mellitus who received education on adherence to routine self-monitoring of blood glucose, standard diabetic diet, and an exercise program delivered by certified diabetes educators had better glycemic control and significant decrease in body weight and fat percentage over a 3-month monitoring period. Copyright 2014, SLACK Incorporated.

  8. Studies on the effect of different operational parameters on the crystallization kinetics of α-lactose monohydrate single crystals in aqueous solution

    Science.gov (United States)

    Parimaladevi, P.; Srinivasan, K.

    2014-09-01

    Supersaturation dependent nucleation, size and morphology of alpha-lactose monohydrate (α-LM) crystals from aqueous solution were investigated by adopting two different crystallization methods, slow evaporation and fast evaporation, in the supersaturation range between σ=0.05 and 1.30. The induction period of nucleation is comparatively long in case of slow evaporation and is very short in case of fast evaporation process as the interconversion between α-L and β-L is uncontrollable in the former and is under control in the latter case. Moreover α-LM crystals with tomahawk morphology were obtained throughout the supersaturation range by slow evaporation method whereas crystals with tomahawk, triangular and needle-like morphologies were obtained in supersaturation ranges σ=0.05-0.5, σ=0.5-0.9 and σ=0.9-1.30 respectively by fast evaporation method. Experimentally observed nucleation parameters were verified with theoretically deuced values. It is realized that the fast evaporation method employed in the present study is found to be highly efficient in controlling the interconversion between α-L and β-L as well as in suppressing the inhibitory activity of β molecule on the nucleation and growth of α-LM crystals when compared to conventional slow evaporation method and is successful in producing the industrially preferred needle-like crystals at high supersaturation ranges.

  9. Effect of Casting Parameters on the Microstructural and Mechanical Behavior of Magnesium AZ31-B Alloy Strips Cast on a Single Belt Casting Simulator

    Directory of Open Access Journals (Sweden)

    Ahmad Changizi

    2014-01-01

    Full Text Available Strips of magnesium alloy AZ31-B were cast on a simulator of a horizontal single belt caster incorporating a moving mold system. Mixtures of CO2 and sulfur hexafluoride (SF6 gases were used as protective atmosphere during melting and casting. The castability of the AZ31-B strips was investigated for a smooth, low carbon steel substrate, and six copper substrates with various textures and roughnesses. Graphite powder was used to coat the substrates. The correlation between strip thickness and heat flux was investigated. It was found that the heat flux from the forming strip to the copper substrate was higher than that to the steel substrate, while coated substrates registered lower heat fluxes than uncoated substrates. The highest heat flux from the strip was recorded for casting on macrotextured copper substrates with 0.15 mm grooves. As the thickness of the strip decreased, the net heat flux decreased. As the heat flux increased, the grain sizes of the strips were reduced, and the SDAS decreased. The mechanical properties were improved when the heat flux increased. The black layers which formed on the strips’ surfaces were analyzed and identified as nanoscale MgO particles. Nano-Scale particles act as light traps and appeared black.

  10. Estimating of aquifer parameters from the single-well water-level measurements in response to advancing longwall mine by using particle swarm optimization

    Science.gov (United States)

    Buyuk, Ersin; Karaman, Abdullah

    2017-04-01

    We estimated transmissivity and storage coefficient values from the single well water-level measurements positioned ahead of the mining face by using particle swarm optimization (PSO) technique. The water-level response to the advancing mining face contains an semi-analytical function that is not suitable for conventional inversion shemes because the partial derivative is difficult to calculate . Morever, the logaritmic behaviour of the model create difficulty for obtaining an initial model that may lead to a stable convergence. The PSO appears to obtain a reliable solution that produce a reasonable fit between water-level data and model function response. Optimization methods have been used to find optimum conditions consisting either minimum or maximum of a given objective function with regard to some criteria. Unlike PSO, traditional non-linear optimization methods have been used for many hydrogeologic and geophysical engineering problems. These methods indicate some difficulties such as dependencies to initial model, evolution of the partial derivatives that is required while linearizing the model and trapping at local optimum. Recently, Particle swarm optimization (PSO) became the focus of modern global optimization method that is inspired from the social behaviour of birds of swarms, and appears to be a reliable and powerful algorithms for complex engineering applications. PSO that is not dependent on an initial model, and non-derivative stochastic process appears to be capable of searching all possible solutions in the model space either around local or global optimum points.

  11. Effect of semiconductor polymer backbone structures and side-chain parameters on the facile separation of semiconducting single-walled carbon nanotubes from as-synthesized mixtures

    Science.gov (United States)

    Lee, Dennis T.; Chung, Jong Won; Park, Geonhee; Kim, Yun-Tae; Lee, Chang Young; Cho, Yeonchoo; Yoo, Pil J.; Han, Jae-Hee; Shin, Hyeon-Jin; Kim, Woo-Jae

    2018-01-01

    Semiconducting single-walled carbon nanotubes (SWNTs) show promise as core materials for next-generation solar cells and nanoelectronic devices. However, most commercial SWNT production methods generate mixtures of metallic SWNTs (m-SWNTs) and semiconducting SWNT (sc-SWNTs). Therefore, sc-SWNTs must be separated from their original mixtures before use. In this study, we investigated a polymer-based, noncovalent sc-SWNT separation approach, which is simple to perform and does not disrupt the electrical properties of the SWNTs, thus improving the performance of the corresponding sc-SWNT-based applications. By systematically investigating the effect that different structural features of the semiconductor polymer have on the separation of sc-SWNTs, we discovered that the length and configuration of the alkyl side chains and the rigidity of the backbone structure exert significant effects on the efficiency of sc-SWNT separation. We also found that electron transfer between the semiconductor polymers and sc-SWNTs is strongly affected by their energy-level alignment, which can be tailored by controlling the donor-acceptor configuration in the polymer backbone structures. Among the polymers investigated, the highly planar P8T2Z-C12 semiconductor polymer showed the best sc-SWNT separation efficiency and unprecedentedly strong electronic interaction with the sc-SWNTs, which is important for improving their performance in applications.

  12. Second Order Sliding Mode Controller Design for Pneumatic Artificial Muscle

    OpenAIRE

    Ammar Al-Jodah; Laith Khames

    2018-01-01

    In this paper, first and second order sliding mode controllers are designed for a single link robotic arm actuated by two Pneumatic Artificial Muscles (PAMs). A new mathematical model for the arm has been developed based on the model of large scale pneumatic muscle actuator model. Uncertainty in parameters has been presented and tested for the two controllers. The simulation results of the second-order sliding mode controller proves to have a low tracking error and chattering effect as compar...

  13. Combined p16 and p53 expression in cervical cancer of unknown primary and other prognostic parameters : A single-center analysis.

    Science.gov (United States)

    Yildirim, Müjdat; Müller von der Grün, Jens; Winkelmann, Ria; Fokas, Emmanouil; Rödel, Franz; Ackermann, Hanns; Rödel, Claus; Balermpas, Panagiotis

    2017-04-01

    Cervical cancer of unknown primary (CUP) represents an uncommon and heterogeneous subentity of head and neck cancer. However, both optimal diagnostics and therapy remain unclear. An improved understanding of the underlying pathology is essential to enable future tailored therapies and optimized outcomes. We retrospectively analyzed 53 patients with head and neck CUP and 48 available cervical lymph node specimens. All patients have received radiotherapy between 2007 and 2015. Preradiotherapy involved lymph node specimens were analyzed for p16 and p53 immunoreactivity. The prognostic relevance of the combined p16 and p53 status and other clinical parameters were examined by univariate and multivariate analyses. Median patient age was 61.5 years and median irradiation dose to the involved nodal levels was 66 Gy. Of the 48 evaluated specimens, 13 (27%) were p16-positive and 31 (64.6%) p53-positive. After a median follow up of 32.9 months, patients with p16-negative and simultaneously p53-positive tumors showed a significantly inferior tumor-specific survival (TSS) compared to those with either p16+/p53-, p16+/p53+, or p16-/p53- (univariate: p = 0.055, multivariate: p = 0.038). Other factors with an adverse impact on TSS in the univariate analysis were smoking history (p = 0.032) and nodal stage (p = 0.038). The combined p16- and p53-expression status in cervical metastases of CUP may represent a simple method for risk stratification. Further validation of these biomarkers in large prospective trials is essential to design rational trials for CUP treatment optimization.

  14. Parametic Study of the current limit within a single driver-scaletransport beam line of an induction Linac for Heavy Ion Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Prost, Lionel Robert [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program that explores heavy-ion beam as the driver option for fusion energy production in an Inertial Fusion Energy (IFE) plant. The HCX is a beam transport experiment at a scale representative of the low-energy end of an induction linear accelerator driver. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density ~0.2 μC/m) over long pulse durations (4 μs) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo and, electron and gas cloud effects. We present the results for a coasting 1 MeV K+ ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius) for which the transverse phase-space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor (~80%) is achieved with acceptable emittance growth and beam loss. We achieved good envelope control, and re-matching may only be needed every ten lattice periods (at 80% fill factor) in a longer lattice of similar design. We also show that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics.

  15. Ground-state properties of ordered, partially ordered, and random Cu-Au and Ni-Pt alloys

    DEFF Research Database (Denmark)

    Ruban, Andrei; Abrikosov, I. A.; Skriver, Hans Lomholt

    1995-01-01

    We have studied the ground-state properties of ordered, partially ordered, and random Cu-Au and Ni-Pt alloys at the stoichiometric 1/4, 1/2, and 3/4 compositions in the framework of the multisublattice single-site (SS) coherent potential approximation (CPA). Charge-transfer effects in the random ...... for the ordered alloys are in good agreement with experimental data. For all the alloys the calculated ordering energy and the equilibrium lattices parameters are found to be almost exact quadratic functions of the long-range-order parameter....... and the partially ordered alloys are included in the screened impurity model. The prefactor in the Madelung energy is determined by the requirement that the total energy obtained in direct SS CPA calculations should equal the total energy given by the Connolly-Williams expansion based on Green’s function...

  16. Tuning the electrocrystallization parameters of semiconducting Co[TCNQ]2-based materials to yield either single nanowires or crystalline thin films.

    Science.gov (United States)

    Nafady, Ayman; Bond, Alan M; Bilyk, Alexander; Harris, Alexander R; Bhatt, Anand I; O'Mullane, Anthony P; De Marco, Roland

    2007-02-28

    Electrocrystallization of single nanowires and/or crystalline thin films of the semiconducting and magnetic Co[TCNQ]2(H2O)2 (TCNQ=tetracyanoquinodimethane) charge-transfer complex onto glassy carbon, indium tin oxide, or metallic electrodes occurs when TCNQ is reduced in acetonitrile (0.1 M [NBu4][ClO4]) in the presence of hydrated cobalt(II) salts. The morphology of the deposited solid is potential dependent. Other factors influencing the electrocrystallization process include deposition time, concentration, and identity of the Co2+(MeCN) counteranion. Mechanistic details have been elucidated by use of cyclic voltammetry, chronoamperometry, electrochemical quartz crystal microbalance, and galvanostatic methods together with spectroscopic and microscopic techniques. The results provide direct evidence that electrocrystallization takes place through two distinctly different, potential-dependent mechanisms, with progressive nucleation and 3-D growth being controlled by the generation of [TCNQ]*- at the electrode and the diffusion of Co2+(MeCN) from the bulk solution. Images obtained by scanning electron microscopy reveal that electrocrystallization of Co[TCNQ]2(H2O)2 at potentials in the range of 0.1-0 V vs Ag/AgCl, corresponding to the [TCNQ]0/*- diffusion-controlled regime, gives rise to arrays of well-separated, needle-shaped nanowires via the overall reaction 2[TCNQ]*-(MeCN)+Co2+(MeCN)+2H2O right harpoon over left harpoon {Co[TCNQ]2(H2O)2}(s). In this potential region, nucleation and growth occur at randomly separated defect sites on the electrode surface. In contrast, at more negative potentials, a compact film of densely packed, uniformly oriented, hexagonal-shaped nanorods is formed. This is achieved at a substantially increased number of nucleation sites created by direct reduction of a thin film of what is proposed to be cobalt-stabilized {(Co2+)([TCNQ2]*-)2} dimeric anion. Despite the potential-dependent morphology of the electrocrystallized Co[TCNQ]2(H2O)2

  17. 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...

  18. Determining camera parameters for round glassware measurements

    International Nuclear Information System (INIS)

    Baldner, F O; Costa, P B; Leta, F R; Gomes, J F S; Filho, D M E S

    2015-01-01

    Nowadays there are many types of accessible cameras, including digital single lens reflex ones. Although these cameras are not usually employed in machine vision applications, they can be an interesting choice. However, these cameras have many available parameters to be chosen by the user and it may be difficult to select the best of these in order to acquire images with the needed metrological quality. This paper proposes a methodology to select a set of parameters that will supply a machine vision system with the needed quality image, considering the measurement required of a laboratory glassware

  19. Clinical and instrumental evaluation of a cross-linked hyaluronic acid filler dermal injection: effects on nasolabial folds skin biophysical parameters and augmentation from a single-dose, monocentric, open-label trial.

    Science.gov (United States)

    Cameli, Norma; Mariano, Maria; Serio, Mirko; Berardesca, Enzo

    2016-10-01

    When a hyaluronic acid dermal device to fill soft tissues is chosen, efficacy, safety and durability are key concerns. This is an open-label prospective study to instrumentally evaluate the effects of HA filler dermal injection on nasolabial folds skin biophysical parameters and augmentation. A single Italian site treated female subjects aged 40-55, for nasolabial folds, with a single standardized injection. The outcome was evaluated with objective quantitative measurements after 90 (T1) and 180 days (T2) from the injection comparing to baseline (T0) by means of Corneometer (skin hydration measurement), Cutometer (skin elasticity measurement), and Visioface devices for digital and UV computerized image analysis. Secondary endpoints were safety assessment, subject investigator satisfaction with the intervention. Assessment of aesthetic results included photographic documentation. The computerized image analysis confirmed the clinical assessment showing statistically significant reduction in nasolabial folds both at T1 and T2. Visioface® indexes showed a marked and statistical significant response. An excellent profile of satisfaction of the product at T2 from investigators and patients was recorded. Skin hydration and elasticity did not show significant changes. In our study, a standardized HA filler dermal injection on nasolabial folds did not influence skin biophysical parameters such as skin hydration and elasticity. Nasolabial folds showed a persistent and significative response at T2 confirmed by instrumental evaluation. The tolerability and safety profile of the product was excellent.

  20. Large pyramid shaped single crystals of BiFeO{sub 3} by solvothermal synthesis method

    Energy Technology Data Exchange (ETDEWEB)

    Sornadurai, D.; Ravindran, T. R.; Paul, V. Thomas; Sastry, V. Sankara [Condensed Matter Physics Division, Materials Science Group, Physical Metallurgy Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu (India); Condensed Matter Physics Division, Materials Science Group (India)

    2012-06-05

    Synthesis parameters are optimized in order to grow single crystals of multiferroic BiFeO{sub 3}. 2 to 3 mm size pyramid (tetrahedron) shaped single crystals were successfully obtained by solvothermal method. Scanning electron microscopy with EDAX confirmed the phase formation. Raman scattering spectra of bulk BiFeO3 single crystals have been measured which match well with reported spectra.

  1. Design and Simulation of PID parameters self-tuning based on DC speed regulating system

    Directory of Open Access Journals (Sweden)

    Feng Wei Jie

    2016-01-01

    Full Text Available The DC speed regulating system has many difficult issues such as system parameters and PID control parameters are difficult to determine. On the basis of model for a single closed-loop DC speed regulating system, this paper puts forward a method of PID parameters self-tuning based on the step response detection and reduced order equivalent. First, detect system step response and get response parameters. Then equal it to a second order system model, and achieve optimal PID control parameters based on optimal second order system to realize of PID parameters self-tuning. The PID parameters self-tuning process of DC speed regulating system is simulated with the help of MATLAB/Simulink. The simulation results show that the method is simple and effective. The system can obtain good dynamic and static performance when the PID parameters are applied to DC speed regulating system.

  2. 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....

  3. 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...

  4. 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.

  5. WINKLER'S SINGLE-PARAMETER SUBGRADE MODEL FROM ...

    African Journals Online (AJOL)

    Preferred Customer

    SUBGRADE MODELING. Asrat Worku. Department of ... The models give consistently larger stiffness for the Winkler springs as compared to previously proposed similar continuum-based models that ignore the lateral stresses. ...... (ν = 0.25 and E = 40MPa); (b) a medium stiff clay (ν = 0.45 and E = 50MPa). In contrast to this, ...

  6. WINKLER'S SINGLE-PARAMETER SUBGRADE MODEL FROM ...

    African Journals Online (AJOL)

    Preferred Customer

    elastic continuum of finite thickness, and certain simplifying assumptions are made to reduce the mathematical ... 26, 2009. 12 analysis and design of beams and plates on elastic foundations. A number of both analytical and ... differential equations with constant coefficients regardless of the nature of this assumption. It is.

  7. High order Bragg grating microfluidic dye laser

    DEFF Research Database (Denmark)

    Balslev, Søren; Kristensen, Anders

    2004-01-01

    We demonstrate a single mode distributed feedback liquid dye laser, based on a short 133 'rd order Bragg grating defined in a single polymer layer between two glass substrates.......We demonstrate a single mode distributed feedback liquid dye laser, based on a short 133 'rd order Bragg grating defined in a single polymer layer between two glass substrates....

  8. Single and combined effects of zinc and cinnamon essential oil in diet on productive performance, egg quality traits, and blood parameters of laying hens reared under cold stress condition

    Science.gov (United States)

    Torki, Mehran; Akbari, Mohsen; Kaviani, Keyomars

    2015-09-01

    This study was conducted to evaluate the effects of adding zinc (Zn), cinnamon essential oil (Ci), or their combination in diet on productive performance, egg quality, and blood parameters of laying hens reared under cold stress condition (8.8 ± 3 °C). Feed intake (FI), feed conversion ratio (FCR), egg weight (EW), egg production (EP), and egg mass (EM) were evaluated during the 56-day trial period using 120 Lohmann LSL-Lite laying hens. Significant interactions between Ci and Zn on FCR, EW, EP, or EM were observed ( P hens fed the diets including Ci and Zn (as single or combined form) compared to those fed the basal diet. There were significant interactions between Ci and Zn on the serum level of glucose and triglycerides as well as plasma concentration of zinc ( P hens fed the diets including Ci and Zn (together) compared to those fed the basal diet. From the results of the present experiment, it can be concluded that diet supplementation by the combined form of Ci and Zn could have beneficial effects on performance and blood parameters of hens reared under cold stress condition.

  9. Comparative assessment of different methods for the estimation of gait temporal parameters using a single inertial sensor: application to elderly, post-stroke, Parkinson's disease and Huntington's disease subjects.

    Science.gov (United States)

    Trojaniello, Diana; Ravaschio, Andrea; Hausdorff, Jeffrey M; Cereatti, Andrea

    2015-09-01

    The estimation of gait temporal parameters with inertial measurement units (IMU) is a research topic of interest in clinical gait analysis. Several methods, based on the use of a single IMU mounted at waist level, have been proposed for the estimate of these parameters showing satisfactory performance when applied to the gait of healthy subjects. However, the above mentioned methods were developed and validated on healthy subjects and their applicability in pathological gait conditions was not systematically explored. We tested the three best performing methods found in a previous comparative study on data acquired from 10 older adults, 10 hemiparetic, 10 Parkinson's disease and 10 Huntington's disease subjects. An instrumented gait mat was used as gold standard. When pathological populations were analyzed, missed or extra events were found for all methods and a global decrease of their performance was observed to different extents depending on the specific group analyzed. The results revealed that none of the tested methods outperformed the others in terms of accuracy of the gait parameters determination for all the populations except the Parkinson's disease subjects group for which one of the methods performed better than others. The hemiparetic subjects group was the most critical group to analyze (stride duration errors between 4-5 % and step duration errors between 8-13 % of the actual values across methods). Only one method provides estimates of the stance and swing durations which however should be interpreted with caution in pathological populations (stance duration errors between 6-14 %, swing duration errors between 10-32 % of the actual values across populations). Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Second Order Sliding Mode Controller Design for Pneumatic Artificial Muscle

    Directory of Open Access Journals (Sweden)

    Ammar Al-Jodah

    2018-01-01

    Full Text Available In this paper, first and second order sliding mode controllers are designed for a single link robotic arm actuated by two Pneumatic Artificial Muscles (PAMs. A new mathematical model for the arm has been developed based on the model of large scale pneumatic muscle actuator model. Uncertainty in parameters has been presented and tested for the two controllers. The simulation results of the second-order sliding mode controller proves to have a low tracking error and chattering effect as compared to the first order one. The verification has been done by using MATLAB and Simulink software.

  11. Computation of methodology-independent single-ion solvation properties from molecular simulations. IV. Optimized Lennard-Jones interaction parameter sets for the alkali and halide ions in water

    Science.gov (United States)

    Reif, Maria M.; Hünenberger, Philippe H.

    2011-04-01

    The raw single-ion solvation free energies computed from atomistic (explicit-solvent) simulations are extremely sensitive to the boundary conditions and treatment of electrostatic interactions used during these simulations. However, as shown recently [M. A. Kastenholz and P. H. Hünenberger, J. Chem. Phys. 124, 224501 (2006), 10.1529/biophysj.106.083667; M. M. Reif and P. H. Hünenberger, J. Chem. Phys. 134, 144103 (2010)], the application of appropriate correction terms permits to obtain methodology-independent results. The corrected values are then exclusively characteristic of the underlying molecular model including in particular the ion-solvent van der Waals interaction parameters, determining the effective ion size and the magnitude of its dispersion interactions. In the present study, the comparison of calculated (corrected) hydration free energies with experimental data (along with the consideration of ionic polarizabilities) is used to calibrate new sets of ion-solvent van der Waals (Lennard-Jones) interaction parameters for the alkali (Li+, Na+, K+, Rb+, Cs+) and halide (F-, Cl-, Br-, I-) ions along with either the SPC or the SPC/E water models. The experimental dataset is defined by conventional single-ion hydration free energies [Tissandier et al., J. Phys. Chem. A 102, 7787 (1998), 10.1021/jp982638r; Fawcett, J. Phys. Chem. B 103, 11181] along with three plausible choices for the (experimentally elusive) value of the absolute (intrinsic) hydration free energy of the proton, namely, Δ G_hyd^{ominus }[H+] = -1100, -1075 or -1050 kJ mol-1, resulting in three sets L, M, and H for the SPC water model and three sets LE, ME, and HE for the SPC/E water model (alternative sets can easily be interpolated to intermediate Δ G_hyd^{ominus }[H+] values). The residual sensitivity of the calculated (corrected) hydration free energies on the volume-pressure boundary conditions and on the effective ionic radius entering into the calculation of the correction terms is

  12. 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.

  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. Research on Parameter Design of Multi - axis Hydrostatic Transmission Vehicle

    Directory of Open Access Journals (Sweden)

    Zhao Liang

    2017-01-01

    Full Text Available In order to obtain reasonable parameters in the design of driving system of multi-axis hydrostatic transmission vehicle, the working principle of single-side drive of hydrostatic transmission vehicle is introduced. The matching and control of engine and hydraulic pump are analyzed. According to the driving equation of vehicle, The driving force required for driving system is determined, and the parameters of hydraulic motor, hydraulic pump, system working pressure and braking system are designed and calculated, which provides the parameter design for driving system of multi-axis hydrostatic transmission Reliable theoretical basis.

  15. A general first-order global sensitivity analysis method

    International Nuclear Information System (INIS)

    Xu Chonggang; Gertner, George Zdzislaw

    2008-01-01

    Fourier amplitude sensitivity test (FAST) is one of the most popular global sensitivity analysis techniques. The main mechanism of FAST is to assign each parameter with a characteristic frequency through a search function. Then, for a specific parameter, the variance contribution can be singled out of the model output by the characteristic frequency. Although FAST has been widely applied, there are two limitations: (1) the aliasing effect among parameters by using integer characteristic frequencies and (2) the suitability for only models with independent parameters. In this paper, we synthesize the improvement to overcome the aliasing effect limitation [Tarantola S, Gatelli D, Mara TA. Random balance designs for the estimation of first order global sensitivity indices. Reliab Eng Syst Safety 2006; 91(6):717-27] and the improvement to overcome the independence limitation [Xu C, Gertner G. Extending a global sensitivity analysis technique to models with correlated parameters. Comput Stat Data Anal 2007, accepted for publication]. In this way, FAST can be a general first-order global sensitivity analysis method for linear/nonlinear models with as many correlated/uncorrelated parameters as the user specifies. We apply the general FAST to four test cases with correlated parameters. The results show that the sensitivity indices derived by the general FAST are in good agreement with the sensitivity indices derived by the correlation ratio method, which is a non-parametric method for models with correlated parameters

  16. The efficacy of preventive parasternal single injection of bupivacaine on intubation time, blood gas parameters, narcotic requirement, and pain relief after open heart surgery: A randomized clinical trial study

    Directory of Open Access Journals (Sweden)

    Mahmoud Saeidi

    2011-01-01

    Full Text Available Background: Postsurgical pain usually results in some complications in the patients. This study has tried to investigate the effects of parasternal single injection of bupivacaine on postoperative pulmonary and pain consequences in patients after open heart surgery. Methods: : In a prospective double blind clinical study, 100 consenting patients undergoing elective open heart surgery were randomized into two groups. In case group, bupivacaine was injected at both sides of sternum, immediately before sternal closure. In the control group, no intervention was performed. Then, the patients were investigated regarding intubation period, length of ICU stay, arterial blood gas (ABG parameters, morphine requirement, and their severity of postoperative pain using a visual analogue scale (VAS device. Results: No differences were found between the two groups regarding to age, sex, pump time, operation time, and body mass index and preoperative cardiac ejection fraction. Mean intubation length in case group was much shorter than that in control group. Mean PaO 2 in case group was lower in different checking times in postoperative period. The patients in the case group needed less morphine compared to those in the control group during the 24-hour observation period in the ICU. Finally, mean VAS scores of pain in case group were significantly lower than those in control group at 6, 12, and 24 hours postoperatively. Conclusions: Patients′ pain relief by parasternal single injection of bupivacaine in early postoperative period can facilitate earlier ventilator weaning and tracheal extubation after open heart surgery as well as achieving lower pain scores and narcotic requirements.

  17. Comparative effect of order based resistance exercises on number of repetitions, rating of perceived exertion and muscle damage biomarkers in men

    Directory of Open Access Journals (Sweden)

    H. Arazi

    2015-12-01

    Conclusion: It can be concluded that both of the resistance exercise orders were equally effective in muscle damage parameters (CK, lactate, RPE and the average of the total number of exercise repetitions, although when the exercise session progressed, the number of repetitions performed to volitional failure decreased in last exercise in one single order, and the exercise order can influence performance.

  18. Relationship between lung function and quantitative computed tomographic parameters of airway remodeling, air trapping, and emphysema in patients with asthma and chronic obstructive pulmonary disease: A single-center study.

    Science.gov (United States)

    Hartley, Ruth A; Barker, Bethan L; Newby, Chris; Pakkal, Mini; Baldi, Simonetta; Kajekar, Radhika; Kay, Richard; Laurencin, Marie; Marshall, Richard P; Sousa, Ana R; Parmar, Harsukh; Siddiqui, Salman; Gupta, Sumit; Brightling, Chris E

    2016-05-01

    There is a paucity of studies comparing asthma and chronic obstructive pulmonary disease (COPD) based on thoracic quantitative computed tomographic (QCT) parameters. We sought to compare QCT parameters of airway remodeling, air trapping, and emphysema between asthmatic patients and patients with COPD and explore their relationship with airflow limitation. Asthmatic patients (n = 171), patients with COPD (n = 81), and healthy subjects (n = 49) recruited from a single center underwent QCT and clinical characterization. Proximal airway percentage wall area (%WA) was significantly increased in asthmatic patients (62.5% [SD, 2.2]) and patients with COPD (62.7% [SD, 2.3]) compared with that in healthy control subjects (60.3% [SD, 2.2], P lung density expiratory/inspiratory ratio was significantly increased in patients with COPD (mean, 0.922 [SD, 0.037]) and asthmatic patients (mean, 0.852 [SD, 0.061]) compared with that in healthy subjects (mean, 0.816 [SD, 0.066], P Emphysema assessed based on lung density measured by using Hounsfield units below which 15% of the voxels lie (Perc15) was a feature of COPD only (patients with COPD: mean, -964 [SD, 19.62] vs asthmatic patients: mean, -937 [SD, 22.7] and healthy subjects: mean, -937 [SD, 17.1], P lung function impairment in asthmatic patients was %WA, whereas in the COPD and asthma subgrouped with postbronchodilator FEV1 percent predicted value of less than 80%, it was air trapping. Factor analysis of QCT parameters in asthmatic patients and patients with COPD combined determined 3 components, with %WA, air trapping, and Perc15 values being the highest loading factors. Cluster analysis identified 3 clusters with mild, moderate, or severe lung function impairment with corresponding decreased lung density (Perc15 values) and increased air trapping. In asthmatic patients and patients with COPD, lung function impairment is strongly associated with air trapping, with a contribution from proximal airway narrowing in

  19. 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.

  20. How to apply the Score-Function method to standard discrete event simulation tools in order to optimise a set of system parameters simultaneously: A Job-Shop example will be discussed

    DEFF Research Database (Denmark)

    Nielsen, Erland Hejn

    2000-01-01

    During the last 1-2 decades, simulation optimisation of discrete event dynamic systems (DEDS) has made considerable theoretical progress with respect to computational efficiency. The score-function (SF) method and the infinitesimal perturbation analysis (IPA) are two candidates belonging to this ...... of a Job-Shop can be handled by the SF method.......During the last 1-2 decades, simulation optimisation of discrete event dynamic systems (DEDS) has made considerable theoretical progress with respect to computational efficiency. The score-function (SF) method and the infinitesimal perturbation analysis (IPA) are two candidates belonging...... to this new class of methods, where one single simulation run in principle is sufficient for the estimation of any desired number of partial gradients. Embedded in an iterative set-up both the SF and the IPA methods belong to the class of Stochastic Approximation (SA) algorithms and furthermore...