WorldWideScience

Sample records for one-dimensional full wave

  1. One-dimensional full wave treatment of mode conversion process at the ion-ion hybrid resonance in a bounded tokamak plasma

    Monakhov, I.; Becoulet, A.; Fraboulet, D.; NGuyen, F.

    1998-09-01

    A consistent picture of the mode conversion (MC) process at the ion-ion hybrid resonance in a bounded plasma of a tokamak is discussed, which clarifies the role of the global fast wave interference and cavity effects in the determination of the MC efficiency. This picture is supported by simulations with one-dimensional full wave kinetic code 'VICE'. The concept of the 'global resonator', formed by the R = n 2 || boundary cutoffs [B. Saoutic et al., Phys. Rev. Lett. 76, 1647 (1996)], is justified, as well as the importance of a proper tunneling factor choice η cr = 0.22 [A. K. Ram et al., Phys. Plasmas 3, 1976 (1996)]. The MC scheme behavior appears to be very sensitive to the MC layer position relative to the global wave field pattern, i.e. to the local value of 'poloidal' electric field at the resonance. Optimal MC regimes are found to be attainable without requirement of a particular parallel wavenumber choice. (author)

  2. Energy in one-dimensional linear waves

    Repetto, C E; Roatta, A; Welti, R J

    2011-01-01

    This work is based on propagation phenomena that conform to the classical wave equation. General expressions of power, the energy conservation equation in continuous media and densities of the kinetic and potential energies are presented. As an example, we study the waves in a string and focused attention on the case of standing waves. The treatment is applicable to introductory science textbooks. (letters and comment)

  3. State reconstruction of one-dimensional wave packets

    Krähmer, D. S.; Leonhardt, U.

    1997-12-01

    We review and analyze the method [U. Leonhardt, M.G. Raymer: Phys. Rev. Lett. 76, 1985 (1996)] for quantum-state reconstruction of one-dimensional non-relativistic wave packets from position observations. We illuminate the theoretical background of the technique and show how to extend the procedure to the continuous part of the spectrum.

  4. Energy in one-dimensional linear waves in a string

    Burko, Lior M

    2010-01-01

    We consider the energy density and energy transfer in small amplitude, one-dimensional waves on a string and find that the common expressions used in textbooks for the introductory physics with calculus course give wrong results for some cases, including standing waves. We discuss the origin of the problem, and how it can be corrected in a way appropriate for the introductory calculus-based physics course. (letters and comments)

  5. Solitons in one-dimensional charge density wave systems

    Su, W.P.

    1981-01-01

    Theoretical research on one dimensional charge density wave systems is outlined. A simple coupled electron-photon Hamiltonian is studied including a Green's function approach, molecular dynamics, and Monte Carlo path integral method. As in superconductivity, the nonperturbative nature of the system makes the physical ground states and low energy excitations drastically different from the bare electrons and phonons. Solitons carry quantum numbers which are entirely different from those of the bare electrons and holes. The fractional charge character of the solitons is an example of this fact. Solitons are conveniently generated by doping material with donors or acceptors or by photon absorption. Most predictions of the theory are in qualitative agreement with experiments. The one dimensional charge density wave system has potential technological importance and a possible role in uncovering phenomena which might have implications in relativistic field theory and elementary particle physics

  6. Nonlinear acoustic wave propagating in one-dimensional layered system

    Yun, Y.; Miao, G.Q.; Zhang, P.; Huang, K.; Wei, R.J.

    2005-01-01

    The propagation of finite-amplitude plane sound in one-dimensional layered media is studied by the extended method of transfer matrix formalism. For the periodic layered system consisting of two alternate types of liquid, the energy distribution and the phase vectors of the interface vibration are computed and analyzed. It is found that in the pass-band, the second harmonic of sound wave can propagate with the characteristic modulation

  7. Periodic solutions for one dimensional wave equation with bounded nonlinearity

    Ji, Shuguan

    2018-05-01

    This paper is concerned with the periodic solutions for the one dimensional nonlinear wave equation with either constant or variable coefficients. The constant coefficient model corresponds to the classical wave equation, while the variable coefficient model arises from the forced vibrations of a nonhomogeneous string and the propagation of seismic waves in nonisotropic media. For finding the periodic solutions of variable coefficient wave equation, it is usually required that the coefficient u (x) satisfies ess infηu (x) > 0 with ηu (x) = 1/2 u″/u - 1/4 (u‧/u)2, which actually excludes the classical constant coefficient model. For the case ηu (x) = 0, it is indicated to remain an open problem by Barbu and Pavel (1997) [6]. In this work, for the periods having the form T = 2p-1/q (p , q are positive integers) and some types of boundary value conditions, we find some fundamental properties for the wave operator with either constant or variable coefficients. Based on these properties, we obtain the existence of periodic solutions when the nonlinearity is monotone and bounded. Such nonlinearity may cross multiple eigenvalues of the corresponding wave operator. In particular, we do not require the condition ess infηu (x) > 0.

  8. Statistical properties of nonlinear one-dimensional wave fields

    D. Chalikov

    2005-01-01

    Full Text Available A numerical model for long-term simulation of gravity surface waves is described. The model is designed as a component of a coupled Wave Boundary Layer/Sea Waves model, for investigation of small-scale dynamic and thermodynamic interactions between the ocean and atmosphere. Statistical properties of nonlinear wave fields are investigated on a basis of direct hydrodynamical modeling of 1-D potential periodic surface waves. The method is based on a nonstationary conformal surface-following coordinate transformation; this approach reduces the principal equations of potential waves to two simple evolutionary equations for the elevation and the velocity potential on the surface. The numerical scheme is based on a Fourier transform method. High accuracy was confirmed by validation of the nonstationary model against known solutions, and by comparison between the results obtained with different resolutions in the horizontal. The scheme allows reproduction of the propagation of steep Stokes waves for thousands of periods with very high accuracy. The method here developed is applied to simulation of the evolution of wave fields with large number of modes for many periods of dominant waves. The statistical characteristics of nonlinear wave fields for waves of different steepness were investigated: spectra, curtosis and skewness, dispersion relation, life time. The prime result is that wave field may be presented as a superposition of linear waves is valid only for small amplitudes. It is shown as well, that nonlinear wave fields are rather a superposition of Stokes waves not linear waves. Potential flow, free surface, conformal mapping, numerical modeling of waves, gravity waves, Stokes waves, breaking waves, freak waves, wind-wave interaction.

  9. Statistical properties of nonlinear one-dimensional wave fields

    Chalikov, D.

    2005-06-01

    A numerical model for long-term simulation of gravity surface waves is described. The model is designed as a component of a coupled Wave Boundary Layer/Sea Waves model, for investigation of small-scale dynamic and thermodynamic interactions between the ocean and atmosphere. Statistical properties of nonlinear wave fields are investigated on a basis of direct hydrodynamical modeling of 1-D potential periodic surface waves. The method is based on a nonstationary conformal surface-following coordinate transformation; this approach reduces the principal equations of potential waves to two simple evolutionary equations for the elevation and the velocity potential on the surface. The numerical scheme is based on a Fourier transform method. High accuracy was confirmed by validation of the nonstationary model against known solutions, and by comparison between the results obtained with different resolutions in the horizontal. The scheme allows reproduction of the propagation of steep Stokes waves for thousands of periods with very high accuracy. The method here developed is applied to simulation of the evolution of wave fields with large number of modes for many periods of dominant waves. The statistical characteristics of nonlinear wave fields for waves of different steepness were investigated: spectra, curtosis and skewness, dispersion relation, life time. The prime result is that wave field may be presented as a superposition of linear waves is valid only for small amplitudes. It is shown as well, that nonlinear wave fields are rather a superposition of Stokes waves not linear waves. Potential flow, free surface, conformal mapping, numerical modeling of waves, gravity waves, Stokes waves, breaking waves, freak waves, wind-wave interaction.

  10. Wave Transformation Over Reefs: Evaluation of One-Dimensional Numerical Models

    Demirbilek, Zeki; Nwogu, Okey G; Ward, Donald L; Sanchez, Alejandro

    2009-01-01

    Three one-dimensional (1D) numerical wave models are evaluated for wave transformation over reefs and estimates of wave setup, runup, and ponding levels in an island setting where the beach is fronted by fringing reef and lagoons...

  11. Electron Rydberg wave packets in one-dimensional atoms

    produced by the application of a single impulsive kick was explicitly demonstrated. The undulation of ..... In this context, let us divide the wave packet .... wave packet with special attention to the time evolution of its components associ- ated with ...

  12. IMPLODING IGNITION WAVES. I. ONE-DIMENSIONAL ANALYSIS

    Kushnir, Doron; Waxman, Eli; Livne, Eli

    2012-01-01

    We show that converging spherical and cylindrical shock waves may ignite a detonation wave in a combustible medium, provided the radius at which the shocks become strong exceeds a critical radius, R crit . An approximate analytic expression for R crit is derived for an ideal gas equation of state and a simple (power-law-Arrhenius) reaction law, and shown to reproduce the results of numerical solutions. For typical acetylene-air experiments we find R crit ∼ 100 μm (spherical) and R crit ∼ 1 mm (cylindrical). We suggest that the deflagration to detonation transition (DDT) observed in these systems may be due to converging shocks produced by the turbulent deflagration flow, which reaches sub- (but near) sonic velocities on scales >>R crit . Our suggested mechanism differs from that proposed by Zel'dovich et al., in which a fine-tuned spatial gradient in the chemical induction time is required to be maintained within the turbulent deflagration flow. Our analysis may be readily extended to more complicated equations of state and reaction laws. An order of magnitude estimate of R crit within a white dwarf at the pre-detonation conditions believed to lead to Type Ia supernova explosions is 0.1 km, suggesting that our proposed mechanism may be relevant for DDT initiation in these systems. The relevance of our proposed ignition mechanism to DDT initiation may be tested by both experiments and numerical simulations.

  13. Propagation of Elastic Waves in a One-Dimensional High Aspect Ratio Nanoridge Phononic Crystal

    Abdellatif Gueddida

    2018-05-01

    Full Text Available We investigate the propagation of elastic waves in a one-dimensional (1D phononic crystal constituted by high aspect ratio epoxy nanoridges that have been deposited at the surface of a glass substrate. With the help of the finite element method (FEM, we calculate the dispersion curves of the modes localized at the surface for propagation both parallel and perpendicular to the nanoridges. When the direction of the wave is parallel to the nanoridges, we find that the vibrational states coincide with the Lamb modes of an infinite plate that correspond to one nanoridge. When the direction of wave propagation is perpendicular to the 1D nanoridges, the localized modes inside the nanoridges give rise to flat branches in the band structure that interact with the surface Rayleigh mode, and possibly open narrow band gaps. Filling the nanoridge structure with a viscous liquid produces new modes that propagate along the 1D finite height multilayer array.

  14. One-Dimensional Mass-Spring Chains Supporting Elastic Waves with Non-Conventional Topology

    2016-04-01

    Full Text Available There are two classes of phononic structures that can support elastic waves with non-conventional topology, namely intrinsic and extrinsic systems. The non-conventional topology of elastic wave results from breaking time reversal symmetry (T-symmetry of wave propagation. In extrinsic systems, energy is injected into the phononic structure to break T-symmetry. In intrinsic systems symmetry is broken through the medium microstructure that may lead to internal resonances. Mass-spring composite structures are introduced as metaphors for more complex phononic crystals with non-conventional topology. The elastic wave equation of motion of an intrinsic phononic structure composed of two coupled one-dimensional (1D harmonic chains can be factored into a Dirac-like equation, leading to antisymmetric modes that have spinor character and therefore non-conventional topology in wave number space. The topology of the elastic waves can be further modified by subjecting phononic structures to externally-induced spatio-temporal modulation of their elastic properties. Such modulations can be actuated through photo-elastic effects, magneto-elastic effects, piezo-electric effects or external mechanical effects. We also uncover an analogy between a combined intrinsic-extrinsic systems composed of a simple one-dimensional harmonic chain coupled to a rigid substrate subjected to a spatio-temporal modulation of the side spring stiffness and the Dirac equation in the presence of an electromagnetic field. The modulation is shown to be able to tune the spinor part of the elastic wave function and therefore its topology. This analogy between classical mechanics and quantum phenomena offers new modalities for developing more complex functions of phononic crystals and acoustic metamaterials.

  15. Wave packet fractional revivals in a one-dimensional Rydberg atom

    Veilande, Rita; Bersons, Imants

    2007-01-01

    We investigate many characteristic features of revival and fractional revival phenomena via derived analytic expressions for an autocorrelation function of a one-dimensional Rydberg atom with weighting probabilities modelled by a Gaussian or a Lorentzian distribution. The fractional revival phenomenon in the ionization probabilities of a one-dimensional Rydberg atom irradiated by two short half-cycle pulses is also studied. When many states are involved in the formation of the wave packet, the revival is lower and broader than the initial wave packet and the fractional revivals overlap and disappear with time

  16. Propagation of acoustic waves in a one-dimensional macroscopically inhomogeneous poroelastic material.

    Gautier, G; Kelders, L; Groby, J P; Dazel, O; De Ryck, L; Leclaire, P

    2011-09-01

    Wave propagation in macroscopically inhomogeneous porous materials has received much attention in recent years. The wave equation, derived from the alternative formulation of Biot's theory of 1962, was reduced and solved recently in the case of rigid frame inhomogeneous porous materials. This paper focuses on the solution of the full wave equation in which the acoustic and the elastic properties of the poroelastic material vary in one-dimension. The reflection coefficient of a one-dimensional macroscopically inhomogeneous porous material on a rigid backing is obtained numerically using the state vector (or the so-called Stroh) formalism and Peano series. This coefficient can then be used to straightforwardly calculate the scattered field. To validate the method of resolution, results obtained by the present method are compared to those calculated by the classical transfer matrix method at both normal and oblique incidence and to experimental measurements at normal incidence for a known two-layers porous material, considered as a single inhomogeneous layer. Finally, discussion about the absorption coefficient for various inhomogeneity profiles gives further perspectives. © 2011 Acoustical Society of America

  17. Stimulated wave of polarization in a one-dimensional Ising chain

    Lee, Jae-Seung; Khitrin, A.K.

    2005-01-01

    It is demonstrated that in a one-dimensional Ising chain with nearest-neighbor interactions, irradiated by a weak resonant transverse field, a stimulated wave of flipped spins can be triggered by a flip of a single spin. This analytically solvable model illustrates mechanisms of quantum amplification and quantum measurement

  18. Nonlinear behavior of a monochromatic wave in a one-dimensional Vlasov plasma

    Shoucri, M.M.; Gagne, R.R.J.

    1978-01-01

    The nonlinear evolution of a monochromatic wave in a one-dimensional Vlasov plasma is studied numerically. The numerical results are carried out far enough in time for phase mixing to dominate the asymptotic state of the system. A qualitative comparison with previously reported simulations is given

  19. Advances in one-dimensional wave mechanics towards a unified classical view

    Cao, Zhuangqi

    2014-01-01

    Advances in One-Dimensional Wave Mechanics provides a comprehensive description of the motion of microscopic particles in one-dimensional, arbitrary-shaped potentials based on the analogy between Quantum Mechanics and Electromagnetism. Utilizing a deeper understanding of the wave nature of matter, this book introduces the concept of the scattered sub-waves and a series of new analytical results using the Analytical Transfer Matrix (ATM) method. This work will be useful for graduate students majoring in physics, mainly in basic quantum theory, as well as for academic researchers exploring electromagnetism, particle physics, and wave mechanics and for experts in the field of optical waveguide and integrated optics. Prof. Zhuangqi Cao is a Professor of Physics at Shanghai Jiao Tong University, China. Dr. Cheng Yin is a teacher at Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology, Hohai University, China.

  20. LETTERS AND COMMENTS: Energy in one-dimensional linear waves in a string

    Burko, Lior M.

    2010-09-01

    We consider the energy density and energy transfer in small amplitude, one-dimensional waves on a string and find that the common expressions used in textbooks for the introductory physics with calculus course give wrong results for some cases, including standing waves. We discuss the origin of the problem, and how it can be corrected in a way appropriate for the introductory calculus-based physics course.

  1. Method to map one-dimensional electronic wave function by using multiple Brillouin zone angle resolved photoemission

    Dong-Wook Lee

    2010-10-01

    Full Text Available Angle resolved photoemission spectroscopy (ARPES is a powerful tool to investigate electronic structures in solids and has been widely used in studying various materials. The electronic structure information by ARPES is obtained in the momentum space. However, in the case of one-dimensional system, we here show that we extract the real space information from ARPES data taken over multiple Brillouin zones (BZs. Intensities in the multiple BZs are proportional to the photoemission matrix element which contains information on the coefficient of the Bloch wave function. It is shown that the Bloch wave function coefficients can be extracted from ARPES data, which allows us to construct the real space wave function. As a test, we use ARPES data from proto-typical one-dimensional system SrCuO2 and construct the real space wave function.

  2. Advances in one-dimensional wave mechanics. Towards a unified classical view

    Cao, Zhuangqi [Shanghai Jiao Tong Univ., (China). Dept. of Physics and Astronomy; Yin, Cheng [Hohai Univ., Changzhou, Jiangsu (China). College of IoT Engineering

    2014-06-01

    Introduces a completely new concept of the scattered sub-waves via the Analytical Transfer Matrix (ATM) method. Develops a relatively simple method to accurately solve one-dimensional problems in quantum mechanics. Based on the analogy between the Quantum Mechanics and Electromagnetism, several interesting issues in quantum mechanics, such as tunneling, quantum reflection and scattering time are restudied. Advances in One-Dimensional Wave Mechanics provides a comprehensive description of the motion of microscopic particles in one-dimensional, arbitrary-shaped potentials based on the analogy between Quantum Mechanics and Electromagnetism. Utilizing a deeper understanding of the wave nature of matter, this book introduces the concept of the scattered sub-waves and a series of new analytical results using the Analytical Transfer Matrix (ATM) method. This work will be useful for graduate students majoring in physics, mainly in basic quantum theory, as well as for academic researchers exploring electromagnetism, particle physics, and wave mechanics and for experts in the field of optical waveguide and integrated optics.

  3. Advances in one-dimensional wave mechanics. Towards a unified classical view

    Cao, Zhuangqi; Yin, Cheng

    2014-01-01

    Introduces a completely new concept of the scattered sub-waves via the Analytical Transfer Matrix (ATM) method. Develops a relatively simple method to accurately solve one-dimensional problems in quantum mechanics. Based on the analogy between the Quantum Mechanics and Electromagnetism, several interesting issues in quantum mechanics, such as tunneling, quantum reflection and scattering time are restudied. Advances in One-Dimensional Wave Mechanics provides a comprehensive description of the motion of microscopic particles in one-dimensional, arbitrary-shaped potentials based on the analogy between Quantum Mechanics and Electromagnetism. Utilizing a deeper understanding of the wave nature of matter, this book introduces the concept of the scattered sub-waves and a series of new analytical results using the Analytical Transfer Matrix (ATM) method. This work will be useful for graduate students majoring in physics, mainly in basic quantum theory, as well as for academic researchers exploring electromagnetism, particle physics, and wave mechanics and for experts in the field of optical waveguide and integrated optics.

  4. Non-reciprocal wave propagation in one-dimensional nonlinear periodic structures

    Benbiao Luo

    2018-01-01

    Full Text Available We study a one-dimensional nonlinear periodic structure which contains two different spring stiffness and an identical mass in each period. The linear dispersion relationship we obtain indicates that our periodic structure has obvious advantages compared to other kinds of periodic structures (i.e. those with the same spring stiffness but two different mass, including its increased flexibility for manipulating the band gap. Theoretically, the optical cutoff frequency remains unchanged while the acoustic cutoff frequency shifts to a lower or higher frequency. A numerical simulation verifies the dispersion relationship and the effect of the amplitude-dependent signal filter. Based upon this, we design a device which contains both a linear periodic structure and a nonlinear periodic structure. When incident waves with the same, large amplitude pass through it from opposite directions, the output amplitude of the forward input is one order magnitude larger than that of the reverse input. Our devised, non-reciprocal device can potentially act as an acoustic diode (AD without an electrical circuit and frequency shifting. Our result represents a significant step forwards in the research of non-reciprocal wave manipulation.

  5. Stable one-dimensional periodic waves in Kerr-type saturable and quadratic nonlinear media

    Kartashov, Yaroslav V; Egorov, Alexey A; Vysloukh, Victor A; Torner, Lluis

    2004-01-01

    We review the latest progress and properties of the families of bright and dark one-dimensional periodic waves propagating in saturable Kerr-type and quadratic nonlinear media. We show how saturation of the nonlinear response results in the appearance of stability (instability) bands in a focusing (defocusing) medium, which is in sharp contrast with the properties of periodic waves in Kerr media. One of the key results discovered is the stabilization of multicolour periodic waves in quadratic media. In particular, dark-type waves are shown to be metastable, while bright-type waves are completely stable in a broad range of energy flows and material parameters. This yields the first known example of completely stable periodic wave patterns propagating in conservative uniform media supporting bright solitons. Such results open the way to the experimental observation of the corresponding self-sustained periodic wave patterns

  6. Broadband one-dimensional photonic crystal wave plate containing single-negative materials.

    Chen, Yihang

    2010-09-13

    The properties of the phase shift of wave reflected from one-dimensional photonic crystals consisting of periodic layers of single-negative (permittivity- or permeability-negative) materials are demonstrated. As the incident angle increases, the reflection phase shift of TE wave decreases, while that of TM wave increases. The phase shifts of both polarized waves vary smoothly as the frequency changes across the photonic crystal stop band. Consequently, the difference between the phase shift of TE and that of TM wave could remain constant in a rather wide frequency range inside the stop band. These properties are useful to design wave plate or retarder which can be used in wide spectral band. In addition, a broadband photonic crystal quarter-wave plate is proposed.

  7. Wave propagation inside one-dimensional photonic crystals with single-negative materials

    Wang Ligang; Chen Hong; Zhu Shiyao

    2006-01-01

    The propagation of light waves in one-dimensional photonic crystals (1DPCs) composed of alternating layers of two kinds of single-negative materials is investigated theoretically. The phase velocity is negative when the frequency of the light wave is smaller than the certain critical frequency ω cr , while the Poynting vector is always positive. At normal incidence, such 1DPCs may act as equivalent left-handed materials. At the inclined incidence, the effective wave vectors inside such 1DPCs do refract negatively, while the effective energy flows do not refract negatively. Therefore, at the inclined incidence, the 1DPCs are not equivalent to the left-handed materials

  8. SSS: A code for computing one dimensional shock and detonation wave propagation

    Sun Chengwei

    1986-01-01

    The one-dimensional hydrodynamic code SSS for shock and detonation wave propagation in inert and reactive media is described. The elastic-plastic-hydrodynamic model and four burn techniques (the Arrhenius law, C-J volume, sharp shock and Forest Fire) are used. There are HOM and JWL options for the state equation of detonation products. Comparing with the SIN code published by LANL, the SSS code has several new options: laser effects, blast waves, diverging and instantaneous detonation waves with arbitrary initiation positions. Two examples are given to compare the SSS and SIN calculations with the experimental data

  9. Travelling wave solutions of the homogeneous one-dimensional FREFLO model

    Huang, B.; Hong, J. Y.; Jing, G. Q.; Niu, W.; Fang, L.

    2018-01-01

    Presently there is quite few analytical studies in traffic flows due to the non-linearity of the governing equations. In the present paper we introduce travelling wave solutions for the homogeneous one-dimensional FREFLO model, which are expressed in the form of series and describe the procedure that vehicles/pedestrians move with a negative velocity and decelerate until rest, then accelerate inversely to positive velocities. This method is expect to be extended to more complex situations in the future.

  10. A one-dimensional seismic model for Uturuncu volcano, Bolivia, and its impact on full moment tensor inversions

    Shen, Weisen

    2016-11-24

    Using receiver functions, Rayleigh wave phase velocity dispersion determined from ambient noise and teleseismic earthquakes, and Rayleigh wave horizontal to vertical ground motion amplitude ratios from earthquakes observed across the PLUTONS seismic array, we construct a one-dimensional (1-D) S-wave velocity (Vs) seismic model with uncertainties for Uturuncu volcano, Bolivia, located in the central Andes and overlying the eastward-subducting Nazca plate. We find a fast upper crustal lid placed upon a low-velocity zone (LVZ) in the mid-crust. By incorporating all three types of measurements with complimentary sensitivity, we also explore the average density and Vp/Vs (ratio of P-wave to S-wave velocity) structures beneath the young silicic volcanic field. We observe slightly higher Vp/Vs and a decrease in density near the LVZ, which implies a dacitic source of the partially molten magma body. We exploit the impact of the 1-D model on full moment tensor inversion for the two largest local earthquakes recorded (both magnitude ∼3), demonstrating that the 1-D model influences the waveform fits and the estimated source type for the full moment tensor. Our 1-D model can serve as a robust starting point for future efforts to determine a three-dimensional velocity model for Uturuncu volcano.

  11. A one-dimensional seismic model for Uturuncu volcano, Bolivia, and its impact on full moment tensor inversions

    Shen, Weisen; Alvizuri, Celso; Lin, Fan-Chi; Tape, Carl

    2016-01-01

    Using receiver functions, Rayleigh wave phase velocity dispersion determined from ambient noise and teleseismic earthquakes, and Rayleigh wave horizontal to vertical ground motion amplitude ratios from earthquakes observed across the PLUTONS seismic array, we construct a one-dimensional (1-D) S-wave velocity (Vs) seismic model with uncertainties for Uturuncu volcano, Bolivia, located in the central Andes and overlying the eastward-subducting Nazca plate. We find a fast upper crustal lid placed upon a low-velocity zone (LVZ) in the mid-crust. By incorporating all three types of measurements with complimentary sensitivity, we also explore the average density and Vp/Vs (ratio of P-wave to S-wave velocity) structures beneath the young silicic volcanic field. We observe slightly higher Vp/Vs and a decrease in density near the LVZ, which implies a dacitic source of the partially molten magma body. We exploit the impact of the 1-D model on full moment tensor inversion for the two largest local earthquakes recorded (both magnitude ∼3), demonstrating that the 1-D model influences the waveform fits and the estimated source type for the full moment tensor. Our 1-D model can serve as a robust starting point for future efforts to determine a three-dimensional velocity model for Uturuncu volcano.

  12. Dispersion relation of electromagnetic waves in one-dimensional plasma photonic crystals

    Hojo, Hitoshi; Mase, Atsushi

    2004-01-01

    The dispersion relation of electromagnetic waves in one-dimensional plasma photonic crystals is studied. The plasma photonic crystal is a periodic array composed of alternating thin plasma and dielectric material. The dispersion relation is obtained by solving a Maxwell wave equation using a method analogous to Kronig-Penny's problem in quantum mechanics, and it is found that the frequency gap and cut-off appear in the dispersion relation. The frequency gap is shown to become larger with the increase of the plasma density as well as plasma width. (author)

  13. A One-Dimensional Wave Equation with White Noise Boundary Condition

    Kim, Jong Uhn

    2006-01-01

    We discuss the Cauchy problem for a one-dimensional wave equation with white noise boundary condition. We also establish the existence of an invariant measure when the noise is additive. Similar problems for parabolic equations were discussed by several authors. To our knowledge, there is only one work which investigated the initial-boundary value problem for a wave equation with random noise at the boundary. We handle a more general case by a different method. Our result on the existence of an invariant measure relies on the author's recent work on a certain class of stochastic evolution equations

  14. Normal Reflection Characteristics of One-Dimensional Unsteady Flow Shock Waves on Rigid Walls from Pulse Discharge in Water

    Dong Yan

    2017-01-01

    Full Text Available Strong shock waves can be generated by pulse discharge in water, and the characteristics due to the shock wave normal reflection from rigid walls have important significance to many fields, such as industrial production and defense construction. This paper investigates the effects of hydrostatic pressures and perturbation of wave source (i.e., charging voltage on normal reflection of one-dimensional unsteady flow shock waves. Basic properties of the incidence and reflection waves were analyzed theoretically and experimentally to identify the reflection mechanisms and hence the influencing factors and characteristics. The results indicated that increased perturbation (i.e., charging voltage leads to increased peak pressure and velocity of the reflected shock wave, whereas increased hydrostatic pressure obviously inhibited superposition of the reflection waves close to the rigid wall. The perturbation of wave source influence on the reflected wave was much lower than that on the incident wave, while the hydrostatic pressure obviously affected both incident and reflection waves. The reflection wave from the rigid wall in water exhibited the characteristics of a weak shock wave, and with increased hydrostatic pressure, these weak shock wave characteristics became more obvious.

  15. Evolution of a wave packet scattered by a one-dimensional potential

    Khachatrian, A Zh; Alexanyan, Al G; Khoetsyan, V A; Alexanyan, N A

    2013-06-30

    We consider the evolution of a wave packet that is made up of a group of the wave functions describing the stationary scattering process and tunnels through a one-dimensional potential of arbitrary form. As the main characteristics of the time difference of the tunnelling process, use is made of the propagation speed of the wave-packet maximum. We show that the known Hartman formula for the tunnelling time corresponds to the wave packet with a wavenumber-uniform spectral composition in the case, when the phase and transmission coefficient modulus dispersions are taken into account only in the linear approximation. The amplitude of the main peak of the transmitted wave intensity is proven to be independent of the tunnelling time and is determined by the transmission coefficient of the spectral component at the carrier frequency and the spectral width of the wave packet. In the limit of an infinitely wide potential barrier the amplitude of the wave-packet maximum is shown to tend to zero slower than the tunnelling time tends to its asymptotic value, i.e., indeed we deal with the paradox of an infinitely large propagation speed of a wave disturbance through the barrier. (propagation of wave fronts)

  16. Evolution of a wave packet scattered by a one-dimensional potential

    Khachatrian, A Zh; Alexanyan, Al G; Khoetsyan, V A; Alexanyan, N A

    2013-01-01

    We consider the evolution of a wave packet that is made up of a group of the wave functions describing the stationary scattering process and tunnels through a one-dimensional potential of arbitrary form. As the main characteristics of the time difference of the tunnelling process, use is made of the propagation speed of the wave-packet maximum. We show that the known Hartman formula for the tunnelling time corresponds to the wave packet with a wavenumber-uniform spectral composition in the case, when the phase and transmission coefficient modulus dispersions are taken into account only in the linear approximation. The amplitude of the main peak of the transmitted wave intensity is proven to be independent of the tunnelling time and is determined by the transmission coefficient of the spectral component at the carrier frequency and the spectral width of the wave packet. In the limit of an infinitely wide potential barrier the amplitude of the wave-packet maximum is shown to tend to zero slower than the tunnelling time tends to its asymptotic value, i.e., indeed we deal with the paradox of an infinitely large propagation speed of a wave disturbance through the barrier. (propagation of wave fronts)

  17. One-dimensional acoustic standing waves in rectangular channels for flow cytometry.

    Austin Suthanthiraraj, Pearlson P; Piyasena, Menake E; Woods, Travis A; Naivar, Mark A; Lόpez, Gabriel P; Graves, Steven W

    2012-07-01

    Flow cytometry has become a powerful analytical tool for applications ranging from blood diagnostics to high throughput screening of molecular assemblies on microsphere arrays. However, instrument size, expense, throughput, and consumable use limit its use in resource poor areas of the world, as a component in environmental monitoring, and for detection of very rare cell populations. For these reasons, new technologies to improve the size and cost-to-performance ratio of flow cytometry are required. One such technology is the use of acoustic standing waves that efficiently concentrate cells and particles to the center of flow channels for analysis. The simplest form of this method uses one-dimensional acoustic standing waves to focus particles in rectangular channels. We have developed one-dimensional acoustic focusing flow channels that can be fabricated in simple capillary devices or easily microfabricated using photolithography and deep reactive ion etching. Image and video analysis demonstrates that these channels precisely focus single flowing streams of particles and cells for traditional flow cytometry analysis. Additionally, use of standing waves with increasing harmonics and in parallel microfabricated channels is shown to effectively create many parallel focused streams. Furthermore, we present the fabrication of an inexpensive optical platform for flow cytometry in rectangular channels and use of the system to provide precise analysis. The simplicity and low-cost of the acoustic focusing devices developed here promise to be effective for flow cytometers that have reduced size, cost, and consumable use. Finally, the straightforward path to parallel flow streams using one-dimensional multinode acoustic focusing, indicates that simple acoustic focusing in rectangular channels may also have a prominent role in high-throughput flow cytometry. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Majorana zero modes in the hopping-modulated one-dimensional p-wave superconducting model.

    Gao, Yi; Zhou, Tao; Huang, Huaixiang; Huang, Ran

    2015-11-20

    We investigate the one-dimensional p-wave superconducting model with periodically modulated hopping and show that under time-reversal symmetry, the number of the Majorana zero modes (MZMs) strongly depends on the modulation period. If the modulation period is odd, there can be at most one MZM. However if the period is even, the number of the MZMs can be zero, one and two. In addition, the MZMs will disappear as the chemical potential varies. We derive the condition for the existence of the MZMs and show that the topological properties in this model are dramatically different from the one with periodically modulated potential.

  19. The high exponent limit $p \\to \\infty$ for the one-dimensional nonlinear wave equation

    Tao, Terence

    2009-01-01

    We investigate the behaviour of solutions $\\phi = \\phi^{(p)}$ to the one-dimensional nonlinear wave equation $-\\phi_{tt} + \\phi_{xx} = -|\\phi|^{p-1} \\phi$ with initial data $\\phi(0,x) = \\phi_0(x)$, $\\phi_t(0,x) = \\phi_1(x)$, in the high exponent limit $p \\to \\infty$ (holding $\\phi_0, \\phi_1$ fixed). We show that if the initial data $\\phi_0, \\phi_1$ are smooth with $\\phi_0$ taking values in $(-1,1)$ and obey a mild non-degeneracy condition, then $\\phi$ converges locally uniformly to a piecewis...

  20. Phase slip process and charge density wave dynamics in a one dimensional conductor

    Habiballah, N.; Zouadi, M.; Arbaoui, A.; Qjani, M.; Dumas, J.

    In this paper, we study the phase slip effect on the charge density wave (CDW) dynamics in a one-dimensional conductor in the weak pinning limit. A considerable enhancement of JCDW is observed in the presence of phase slips. In addition, a spatial dependence of the CDW current density JCDW is also studied showing that a decrease of JCDW with distance from the current contact occurs. The results are discussed in terms the relationship between additional phase slips and the mobility of phase dislocations nucleated at electrical contacts.

  1. Development of a particle method of characteristics (PMOC) for one-dimensional shock waves

    Hwang, Y.-H.

    2018-03-01

    In the present study, a particle method of characteristics is put forward to simulate the evolution of one-dimensional shock waves in barotropic gaseous, closed-conduit, open-channel, and two-phase flows. All these flow phenomena can be described with the same set of governing equations. The proposed scheme is established based on the characteristic equations and formulated by assigning the computational particles to move along the characteristic curves. Both the right- and left-running characteristics are traced and represented by their associated computational particles. It inherits the computational merits from the conventional method of characteristics (MOC) and moving particle method, but without their individual deficiencies. In addition, special particles with dual states deduced to the enforcement of the Rankine-Hugoniot relation are deliberately imposed to emulate the shock structure. Numerical tests are carried out by solving some benchmark problems, and the computational results are compared with available analytical solutions. From the derivation procedure and obtained computational results, it is concluded that the proposed PMOC will be a useful tool to replicate one-dimensional shock waves.

  2. Molecular dynamics of shock waves in one-dimensional chains. II. Thermalization

    Straub, G.K.; Holian, B.L.; Petschek, R.G.

    1979-01-01

    The thermalization behavior behind a shock front in one-dimensional chains has been studied in a series of molecular-dynamics computer experiments. We have found that a shock wave generated in a chain initially at finite temperature has essentially the same characteristics as in a chain initially at zero temperature. We also find that the final velocity distribution function for particles behind the shock front is not the Maxwell-Boltzmann distribution for an equilibrium system of classical particles. For times long after the shock has passed, we propose a nonequilibrium velocity distribution which is based upon behavior in the harmonic and hard-rod limits and agrees with our numerical results. Temperature profiles for both harmonic and anharmonic chains are found to exhibit a long-time tail that decays inversely with time. Finally, we have run a computer experiment to generate what qualitatively resembles solitons in Toda chains by means of shock waves

  3. An Inverse Source Problem for a One-dimensional Wave Equation: An Observer-Based Approach

    Asiri, Sharefa M.

    2013-05-25

    Observers are well known in the theory of dynamical systems. They are used to estimate the states of a system from some measurements. However, recently observers have also been developed to estimate some unknowns for systems governed by Partial differential equations. Our aim is to design an observer to solve inverse source problem for a one dimensional wave equation. Firstly, the problem is discretized in both space and time and then an adaptive observer based on partial field measurements (i.e measurements taken form the solution of the wave equation) is applied to estimate both the states and the source. We see the effectiveness of this observer in both noise-free and noisy cases. In each case, numerical simulations are provided to illustrate the effectiveness of this approach. Finally, we compare the performance of the observer approach with Tikhonov regularization approach.

  4. Instability and damping of one-dimensional high-amplitude Langmuir waves

    Buchel'nikova, N.S.; Matochkin, E.P.

    1981-01-01

    Numerical experiments (methods ''of particles in cells'') on investigation of instability and damping of one-dimensional Langmuir waves in the region Esub(0)sup(2)/8πnT>m/M>(ksub(0)rsub(d))sup(2) ksub(0) is wave vector, M- ion mass, m-electron mass, v=√T/M, vsub(ph)=Wsub(0)/ksub(0), Wsub(0)-proper plasma frequency) are performed. Numerical experiments have been conducted in a wide range of initial parameters of the wave: E 0 2 /8πnT approximately 4x10 2 -10 -2 , vsub(ph)/vsub(T) approximately 3-160, M/m=10 2 , in some cases M/m=10 3 . It is shown that the basic processes are modulation instability with a modulation length less than the wave length, wave conversion at density inhomogeneity and electron capture by the wave or its harmonics. Depending on initial wave parameters the predominant role is played by this or that process. In the range of linear waves Esub(0)sup(2)/8πnT ksub(0)rsub(d) - to the collapse. In the range of 4x10sup(-2)/(ksub(0)rsub(d)sup(2)>Esub(0)sup(2)/8πnT>10sup(-3)/(ksub(0)rsub(d))sup(2) all the three processes play a comparable role. In the range of strong damping Esub(0)sup(2)/8πnT>4x10sup(-2)/(h ksub(0)rsub(d))sup(2) the main part is played by the wave electron capture resulting in damping considerably exceeding the Lamdau damping [ru

  5. Scattering of electromagnetic wave by the layer with one-dimensional random inhomogeneities

    Kogan, Lev; Zaboronkova, Tatiana; Grigoriev, Gennadii., IV.

    A great deal of attention has been paid to the study of probability characteristics of electro-magnetic waves scattered by one-dimensional fluctuations of medium dielectric permittivity. However, the problem of a determination of a density of a probability and average intensity of the field inside the stochastically inhomogeneous medium with arbitrary extension of fluc-tuations has not been considered yet. It is the purpose of the present report to find and to analyze the indicated functions for the plane electromagnetic wave scattered by the layer with one-dimensional fluctuations of permittivity. We assumed that the length and the amplitude of individual fluctuations as well the interval between them are random quantities. All of indi-cated fluctuation parameters are supposed as independent random values possessing Gaussian distribution. We considered the stationary time cases both small-scale and large-scale rarefied inhomogeneities. Mathematically such problem can be reduced to the solution of integral Fred-holm equation of second kind for Hertz potential (U). Using the decomposition of the field into the series of multiply scattered waves we obtained the expression for a probability density of the field of the plane wave and determined the moments of the scattered field. We have shown that all odd moments of the centered field (U-¡U¿) are equal to zero and the even moments depend on the intensity. It was obtained that the probability density of the field possesses the Gaussian distribution. The average field is small compared with the standard fluctuation of scattered field for all considered cases of inhomogeneities. The value of average intensity of the field is an order of a standard of fluctuations of field intensity and drops with increases the inhomogeneities length in the case of small-scale inhomogeneities. The behavior of average intensity is more complicated in the case of large-scale medium inhomogeneities. The value of average intensity is the

  6. A one-dimensional model of the semiannual oscillation driven by convectively forced gravity waves

    Sassi, Fabrizio; Garcia, Rolando R.

    1994-01-01

    A one-dimensional model that solves the time-dependent equations for the zonal mean wind and a wave of specified zonal wavenumber has been used to illustrate the ability of gravity waves forced by time-dependent tropospheric heating to produce a semiannual oscillation (SAO) in the middle atmosphere. When the heating has a strong diurnal cycle, as observed over tropical landmasses, gravity waves with zonal wavelengths of a few thousand kilometers and phase velocities in the range +/- 40-50 m/sec are excited efficiently by the maximum vertical projection criterion (vertical wavelength approximately equals 2 x forcing depth). Calculations show that these waves can account for large zonal mean wind accelerations in the middle atmosphere, resulting in realistic stratopause and mesopause oscillations. Calculations of the temporal evolution of a quasi-conserved tracer indicate strong down-welling in the upper stratosphere near the equinoxes, which is associated with the descent of the SAO westerlies. In the upper mesosphere, there is a semiannual oscillation in tracer mixing ratio driven by seasonal variability in eddy mixing, which increases at the solstices and decreases at the equinoxes.

  7. Effects of delayed nonlinear response on wave packet dynamics in one-dimensional generalized Fibonacci chains

    Zhang, Jianxin; Zhang, Zhenjun; Tong, Peiqing

    2013-01-01

    We investigate the spreading of an initially localized wave packet in one-dimensional generalized Fibonacci (GF) lattices by solving numerically the discrete nonlinear Schrödinger equation (DNLSE) with a delayed cubic nonlinear term. It is found that for short delay time, the wave packet is self-trapping in first class of GF lattices, that is, the second moment grows with time, but the corresponding participation number does not grow. However, both the second moment and the participation number grow with time for large delay time. This illuminates that the wave packet is delocalized. For the second class of GF lattices, the dynamic behaviors of wave packet depend on the strength of on-site potential. For a weak on-site potential, the results are similar to the case of the first class. For a strong on-site potential, both the second moment and the participation number does not grow with time in the regime of short delay time. In the regime of large delay time, both the second moment and the participation number exhibit stair-like growth

  8. Effects of delayed nonlinear response on wave packet dynamics in one-dimensional generalized Fibonacci chains

    Zhang, Jianxin; Zhang, Zhenjun [Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023 (China); Tong, Peiqing, E-mail: pqtong@njnu.edu.cn [Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023 (China); Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems, Nanjing Normal University, Nanjing 210023 (China)

    2013-07-15

    We investigate the spreading of an initially localized wave packet in one-dimensional generalized Fibonacci (GF) lattices by solving numerically the discrete nonlinear Schrödinger equation (DNLSE) with a delayed cubic nonlinear term. It is found that for short delay time, the wave packet is self-trapping in first class of GF lattices, that is, the second moment grows with time, but the corresponding participation number does not grow. However, both the second moment and the participation number grow with time for large delay time. This illuminates that the wave packet is delocalized. For the second class of GF lattices, the dynamic behaviors of wave packet depend on the strength of on-site potential. For a weak on-site potential, the results are similar to the case of the first class. For a strong on-site potential, both the second moment and the participation number does not grow with time in the regime of short delay time. In the regime of large delay time, both the second moment and the participation number exhibit stair-like growth.

  9. Piecewise parabolic method for simulating one-dimensional shear shock wave propagation in tissue-mimicking phantoms

    Tripathi, B. B.; Espíndola, D.; Pinton, G. F.

    2017-11-01

    The recent discovery of shear shock wave generation and propagation in the porcine brain suggests that this new shock phenomenology may be responsible for a broad range of traumatic injuries. Blast-induced head movement can indirectly lead to shear wave generation in the brain, which could be a primary mechanism for injury. Shear shock waves amplify the local acceleration deep in the brain by up to a factor of 8.5, which may tear and damage neurons. Currently, there are numerical methods that can model compressional shock waves, such as comparatively well-studied blast waves, but there are no numerical full-wave solvers that can simulate nonlinear shear shock waves in soft solids. Unlike simplified representations, e.g., retarded time, full-wave representations describe fundamental physical behavior such as reflection and heterogeneities. Here we present a piecewise parabolic method-based solver for one-dimensional linearly polarized nonlinear shear wave in a homogeneous medium and with empirical frequency-dependent attenuation. This method has the advantage of being higher order and more directly extendable to multiple dimensions and heterogeneous media. The proposed numerical scheme is validated analytically and experimentally and compared to other shock capturing methods. A Riemann step-shock problem is used to characterize the numerical dissipation. This dissipation is then tuned to be negligible with respect to the physical attenuation by choosing an appropriate grid spacing. The numerical results are compared to ultrasound-based experiments that measure planar polarized shear shock wave propagation in a tissue-mimicking gelatin phantom. Good agreement is found between numerical results and experiment across a 40 mm propagation distance. We anticipate that the proposed method will be a starting point for the development of a two- and three-dimensional full-wave code for the propagation of nonlinear shear waves in heterogeneous media.

  10. Computational Modeling of Bloch Surface Waves in One-Dimensional Periodic and Aperiodic Multilayer Structures

    Koju, Vijay

    Photonic crystals and their use in exciting Bloch surface waves have received immense attention over the past few decades. This interest is mainly due to their applications in bio-sensing, wave-guiding, and other optical phenomena such as surface field enhanced Raman spectroscopy. Improvement in numerical modeling techniques, state of the art computing resources, and advances in fabrication techniques have also assisted in growing interest in this field. The ability to model photonic crystals computationally has benefited both the theoretical as well as experimental communities. It helps the theoretical physicists in solving complex problems which cannot be solved analytically and helps to acquire useful insights that cannot be obtained otherwise. Experimentalists, on the other hand, can test different variants of their devices by changing device parameters to optimize performance before fabrication. In this dissertation, we develop two commonly used numerical techniques, namely transfer matrix method, and rigorous coupled wave analysis, in C++ and MATLAB, and use two additional software packages, one open-source and another commercial, to model one-dimensional photonic crystals. Different variants of one-dimensional multilayered structures such as perfectly periodic dielectric multilayers, quasicrystals, aperiodic multilayer are modeled, along with one-dimensional photonic crystals with gratings on the top layer. Applications of Bloch surface waves, along with new and novel aperiodic dielectric multilayer structures that support Bloch surface waves are explored in this dissertation. We demonstrate a slow light configuration that makes use of Bloch Surface Waves as an intermediate excitation in a double-prism tunneling configuration. This method is simple compared to the more usual techniques for slowing light using the phenomenon of electromagnetically induced transparency in atomic gases or doped ionic crystals operated at temperatures below 4K. Using a semi

  11. High-efficiency one-dimensional atom localization via two parallel standing-wave fields

    Wang, Zhiping; Wu, Xuqiang; Lu, Liang; Yu, Benli

    2014-01-01

    We present a new scheme of high-efficiency one-dimensional (1D) atom localization via measurement of upper state population or the probe absorption in a four-level N-type atomic system. By applying two classical standing-wave fields, the localization peak position and number, as well as the conditional position probability, can be easily controlled by the system parameters, and the sub-half-wavelength atom localization is also observed. More importantly, there is 100% detecting probability of the atom in the subwavelength domain when the corresponding conditions are satisfied. The proposed scheme may open up a promising way to achieve high-precision and high-efficiency 1D atom localization. (paper)

  12. Matter waves of Bose-Fermi mixtures in one-dimensional optical lattices

    Bludov, Yu. V.; Santhanam, J.; Kenkre, V. M.; Konotop, V. V.

    2006-01-01

    We describe solitary wave excitations in a Bose-Fermi mixture loaded in a one-dimensional and strongly elongated lattice. We focus on the mean-field theory under the condition that the fermion number significantly exceeds the boson number, and limit our consideration to lattice amplitudes corresponding to the order of a few recoil energies or less. In such a case, the fermionic atoms display 'metallic' behavior and are well-described by the effective mass approximation. After classifying the relevant cases, we concentrate on gap solitons and coupled gap solitons in the two limiting cases of large and small fermion density, respectively. In the former, the fermionic atoms are distributed almost homogeneously and thus can move freely along the lattice. In the latter, the fermionic density becomes negligible in the potential maxima, and this leads to negligible fermionic current in the linear regime

  13. Wave propagation in one-dimensional solid-fluid quasi-periodic and aperiodic phononic crystals

    Chen Ali, E-mail: alchen@bjtu.edu.cn [Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044 (China); Wang Yuesheng [Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044 (China); Zhang Chuanzeng [Department of Civil Engineering, University of Siegen, D-57068 Siegen (Germany)

    2012-02-01

    The propagation of the elastic waves in one-dimensional (1D) solid-fluid quasi-periodic phononic crystals is studied by employing the concept of the localization factor, which is calculated by the transfer matrix method. The solid-fluid interaction effect at the interfaces between the solid and the fluid components is considered. For comparison, the periodic systems and aperiodic Thue-Morse sequence are also analyzed in this paper. The splitting phenomenon of the pass bands and bandgaps are discussed for these 1D solid-fluid systems. At last the influences of the material impedance ratios on the band structures of the 1D solid-fluid quasi-periodic phononic crystals arranged as Fibonacci sequence are discussed.

  14. Nonstandard Analysis and Shock Wave Jump Conditions in a One-Dimensional Compressible Gas

    Roy S. Baty, F. Farassat, John A. Hargreaves

    2007-05-25

    Nonstandard analysis is a relatively new area of mathematics in which infinitesimal numbers can be defined and manipulated rigorously like real numbers. This report presents a fairly comprehensive tutorial on nonstandard analysis for physicists and engineers with many examples applicable to generalized functions. To demonstrate the power of the subject, the problem of shock wave jump conditions is studied for a one-dimensional compressible gas. It is assumed that the shock thickness occurs on an infinitesimal interval and the jump functions in the thermodynamic and fluid dynamic parameters occur smoothly across this interval. To use conservations laws, smooth pre-distributions of the Dirac delta measure are applied whose supports are contained within the shock thickness. Furthermore, smooth pre-distributions of the Heaviside function are applied which vary from zero to one across the shock wave. It is shown that if the equations of motion are expressed in nonconservative form then the relationships between the jump functions for the flow parameters may be found unambiguously. The analysis yields the classical Rankine-Hugoniot jump conditions for an inviscid shock wave. Moreover, non-monotonic entropy jump conditions are obtained for both inviscid and viscous flows. The report shows that products of generalized functions may be defined consistently using nonstandard analysis; however, physically meaningful products of generalized functions must be determined from the physics of the problem and not the mathematical form of the governing equations.

  15. Dynamics of laser ablative shock waves from one dimensional periodic structured surfaces

    Paturi, Prem Kiran; Chelikani, Leela; Pinnoju, Venkateshwarlu; Acrhem Team

    2015-06-01

    Spatio-temporal evolution of Laser ablative shock waves (LASWs) from one dimensional periodic structured surfaces (1D-PSS) of Aluminum is studied using time resolved defocused shadowgraphy technique. LASWs are generated by focusing 7 ns pulses from second harmonic of Nd:YAG (532 nm, 10 Hz) laser on to 1D-PSS with sinusoidal and triangular modulations of varying periodicity. An expanded He-Ne laser (632.8 nm) is used as probe beam for shadowgraphy. Evolution of ablative shock front (SF) with 1.5 ns temporal resolution is used to measure position of the SF, its nature, density and pressure behind the SF. The effect of surface modulation on the LASW and contact front dynamics was compared to those from a flat surface (FS) of Aluminum. SWs from FS and PSS obeyed Taylor's solution for spherical and planar nature, respectively. The velocity of SF from 1D PSS had a twofold increase compared to the FS. This was further enhanced for structures whose periodicity is of the order of excitation wavelength. Variation of SF properties with varying periodicity over a range of 3.3 μm to 0.55 μm has the potential to tailor shockwaves of required parameters. The work is supported by Defence Research and Developement Organization, India through Grants-in-Aid Program. The periodic surfaces were procured with financial support from BRFST project No. NFP-MAT-A12-04.

  16. Dynamics in a one-dimensional ferrogel model: relaxation, pairing, shock-wave propagation.

    Goh, Segun; Menzel, Andreas M; Löwen, Hartmut

    2018-05-23

    Ferrogels are smart soft materials, consisting of a polymeric network and embedded magnetic particles. Novel phenomena, such as the variation of the overall mechanical properties by external magnetic fields, emerge consequently. However, the dynamic behavior of ferrogels remains largely unveiled. In this paper, we consider a one-dimensional chain consisting of magnetic dipoles and elastic springs between them as a simple model for ferrogels. The model is evaluated by corresponding simulations. To probe the dynamics theoretically, we investigate a continuum limit of the energy governing the system and the corresponding equation of motion. We provide general classification scenarios for the dynamics, elucidating the touching/detachment dynamics of the magnetic particles along the chain. In particular, it is verified in certain cases that the long-time relaxation corresponds to solutions of shock-wave propagation, while formations of particle pairs underlie the initial stage of the dynamics. We expect that these results will provide insight into the understanding of the dynamics of more realistic models with randomness in parameters and time-dependent magnetic fields.

  17. Optical Effects Induced by Bloch Surface Waves in One-Dimensional Photonic Crystals

    Irina V. Soboleva

    2018-01-01

    Full Text Available The review considers the influence of Bloch surface waves on the optical and magneto-optical effects observed in photonic crystals; for example, the Goos–Hänchen effect, the Faraday effect, optical trapping and so on. Prospects for using Bloch surface waves for spatial light modulation, for controlling the polarization of light, for optical trapping and control of micro-objects are discussed.

  18. Exact Local Correlations and Full Counting Statistics for Arbitrary States of the One-Dimensional Interacting Bose Gas

    Bastianello, Alvise; Piroli, Lorenzo; Calabrese, Pasquale

    2018-05-01

    We derive exact analytic expressions for the n -body local correlations in the one-dimensional Bose gas with contact repulsive interactions (Lieb-Liniger model) in the thermodynamic limit. Our results are valid for arbitrary states of the model, including ground and thermal states, stationary states after a quantum quench, and nonequilibrium steady states arising in transport settings. Calculations for these states are explicitly presented and physical consequences are critically discussed. We also show that the n -body local correlations are directly related to the full counting statistics for the particle-number fluctuations in a short interval, for which we provide an explicit analytic result.

  19. Analogy between soap film and gas dynamics. II. Experiments on one-dimensional motion of shock waves in soap films

    Wen, C.Y.; Chang-Jian, S.K.; Chuang, M.C. [Department of Mechanical Engineering, Da-Yeh University, Chang-Hwa (Taiwan)

    2003-02-01

    This paper presents an experimental investigation of one-dimensional moving shock waves in vertical soap films. The shock waves were generated by bursting the films with a perforating spark. Images of propagating shock waves and small disturbances were recorded using a fast line scan CCD camera. An aureole and a shock wave preceding the rim of the expanding hole were clearly observed. These images are similar to the x-t diagrams in gas dynamics and give the velocities of shock and sound waves. The moving shock waves cause jumps in thickness. The variations of the induced Mach number, M{sub 2} and the ratio of film thickness across the shock wave, {delta}{sub 2}/{delta}{sub 1}, are plotted versus the shock Mach number, M{sub s}. Both results suggest that soap films are analogous to compressible gases with a specific heat ratio of {gamma}{approx_equal}1.0. (orig.)

  20. An Adaptive Physics-Based Method for the Solution of One-Dimensional Wave Motion Problems

    Masoud Shafiei

    2015-12-01

    Full Text Available In this paper, an adaptive physics-based method is developed for solving wave motion problems in one dimension (i.e., wave propagation in strings, rods and beams. The solution of the problem includes two main parts. In the first part, after discretization of the domain, a physics-based method is developed considering the conservation of mass and the balance of momentum. In the second part, adaptive points are determined using the wavelet theory. This part is done employing the Deslauries-Dubuc (D-D wavelets. By solving the problem in the first step, the domain of the problem is discretized by the same cells taking into consideration the load and characteristics of the structure. After the first trial solution, the D-D interpolation shows the lack and redundancy of points in the domain. These points will be added or eliminated for the next solution. This process may be repeated for obtaining an adaptive mesh for each step. Also, the smoothing spline fit is used to eliminate the noisy portion of the solution. Finally, the results of the proposed method are compared with the results available in the literature. The comparison shows excellent agreement between the obtained results and those already reported.

  1. Effects of disorder on atomic density waves and spin-singlet dimers in one-dimensional optical lattices

    Gao Xianlong

    2008-01-01

    Using the Bethe-ansatz density-functional theory, we study a one-dimensional Hubbard model of confined attractively interacting fermions in the presence of a uniformly distributed disorder. The strongly correlated Luther-Emery nature of the attractive one-dimensional Hubbard model is fully taken into account as the reference system in the density-functional theory. The effects of the disorder are investigated on the atomic density waves in the weak-to-intermediate attractive interaction and on the spin-singlet dimers of doubly occupied sites in the strongly attractive regime. It is found that atomic density waves are sensitive to the disorder and the spin-singlet dimers of doubly occupied sites are quite unstable against the disorder. We also show that a very weak disorder could smear the singularities in the stiffness, thus, suppresses the spin-singlet pairs

  2. Quantitative Method to Measure Thermal Conductivity of One-Dimensional Nanostructures Based on Scanning Thermal Wave Microscopy

    Park, Kyung Bae; Chung, Jae Hun; Hwang, Gwang Seok; Jung, Eui Han; Kwon, Oh Myoung [Korea University, Seoul (Korea, Republic of)

    2014-12-15

    We present a method to quantitatively measure the thermal conductivity of one-dimensional nanostructures by utilizing scanning thermal wave microscopy (STWM) at a nanoscale spatial resolution. In this paper, we explain the principle for measuring the thermal diffusivity of one-dimensional nanostructures using STWM and the theoretical analysis procedure for quantifying the thermal diffusivity. The SWTM measurement method obtains the thermal conductivity by measuring the thermal diffusivity, which has only a phase lag relative to the distance corresponding to the transferred thermal wave. It is not affected by the thermal contact resistances between the heat source and nanostructure and between the nanostructure and probe. Thus, the heat flux applied to the nanostructure is accurately obtained. The proposed method provides a very simple and quantitative measurement relative to conventional measurement techniques.

  3. Mapping of spin wave propagation in a one-dimensional magnonic crystal

    Ordóñez-Romero, César L., E-mail: cloro@fisica.unam.mx; Lazcano-Ortiz, Zorayda; Aguilar-Huerta, Melisa; Monsivais, Guillermo [Instituto de Física, Universidad Nacional Autónoma de México, CU, México D.F. 04510 (Mexico); Drozdovskii, Andrey; Kalinikos, Boris [St. Petersburg Electrotechnical University, 197376 St. Petersburg (Russian Federation); International laboratory “MultiferrLab,” ITMO University, 197101 St. Petersburg (Russian Federation); Domínguez-Juárez, J. L. [Cátedras CONACyT, CFATA, Universidad Nacional Autónoma de México, Juriquilla, Querétaro 76230 (Mexico); Lopez-Maldonado, Guillermo [Universidad Autónoma Metropolitana, Lerma de Villada, 52006 Estado de México (Mexico); Qureshi, Naser; Kolokoltsev, Oleg [CCADET, Universidad Nacional Autónoma de México, CU, México D.F. 04510 (Mexico)

    2016-07-28

    The formation and evolution of spin wave band gaps in the transmission spectrum of a magnonic crystal have been studied. A time and space resolved magneto inductive probing system has been used to map the spin wave propagation and evolution in a geometrically structured yttrium iron garnet film. Experiments have been carried out using (1) a chemically etched magnonic crystal supporting the propagation of magnetostatic surface spin waves, (2) a short microwave pulsed excitation of the spin waves, and (3) direct spin wave detection using a movable magneto inductive probe connected to a synchronized fast oscilloscope. The results show that the periodic structure not only modifies the spectra of the transmitted spin waves but also influences the distribution of the spin wave energy inside the magnonic crystal as a function of the position and the transmitted frequency. These results comprise an experimental confirmation of Bloch′s theorem in a spin wave system and demonstrate good agreement with theoretical observations in analogue phononic and photonic systems. Theoretical prediction of the structured transmission spectra is achieved using a simple model based on microwave transmission lines theory. Here, a spin wave system illustrates in detail the evolution of a much more general physical concept: the band gap.

  4. Wave Transformation Over Reefs: Evaluation of One-Dimensional Numerical Models

    2009-01-01

    level estimates. DISCLAIMER: The contents of this report are not to be used for advertising , publication, or promotional purposes. Citation of trade...better with data for wave heights and mean water levels obtained with the DDD85 formula for these mono- chromatic waves. The RMSE values (rms errors

  5. Temperature effects on the band gaps of Lamb waves in a one-dimensional phononic-crystal plate (L).

    Cheng, Y; Liu, X J; Wu, D J

    2011-03-01

    This study investigates the temperature-tuned band gaps of Lamb waves in a one-dimensional phononic-crystal plate, which is formed by alternating strips of ferroelectric ceramic Ba(0.7)Sr(0.3)TiO(3) and epoxy. The sensitive and continuous temperature-tunability of Lamb wave band gaps is demonstrated using the analyses of the band structures and the transmission spectra. The width and position of Lamb wave band gaps shift prominently with variation of temperature in the range of 26 °C-50 °C. For example, the width of the second band gap increases from 0.066 to 0.111 MHz as the temperature is increased from 26 °C to 50 °C. The strong shift promises that the structure could be suitable for temperature-tuned multi-frequency Lamb wave filters. © 2011 Acoustical Society of America

  6. Phase control of spin waves based on a magnetic defect in a one-dimensional magnonic crystal

    Baumgaertl, Korbinian; Watanabe, Sho; Grundler, Dirk

    2018-04-01

    Magnonic crystals are interesting for spin-wave based data processing. We investigate one-dimensional magnonic crystals (1D MCs) consisting of bistable Co 20 Fe 60 B 20 nanostripes separated by 75 nm wide air gaps. By adjusting the magnetic history, we program a single stripe of opposed magnetization in an otherwise saturated 1D MC. Its influence on propagating spin waves is studied via broadband microwave spectroscopy. Depending on an in-plane bias magnetic field, we observe spin wave phase shifts of up to almost π and field-controlled attenuation attributed to the reversed nanostripe. Our findings are of importance for magnetologics, where the control of spin wave phases is essential.

  7. Faraday waves in quasi-one-dimensional superfluid Fermi-Bose mixtures

    Abdullaev, F. Kh.; Ögren, Magnus; Sørensen, Mads Peter

    2013-01-01

    The generation of Faraday waves in superfluid Fermi-Bose mixtures in elongated traps is investigated. The generation of waves is achieved by periodically changing a parameter of the system in time. Two types of modulations of parameters are considered: a variation of the fermion-boson scattering...... length and the boson-boson scattering length. We predict the properties of the generated Faraday patterns and study the parameter regions where they can be excited....

  8. Comment on 'Energy in one-dimensional linear waves in a string'

    Butikov, Eugene I

    2011-01-01

    In this communication we comment on numerous erroneous statements in a recent letter to this journal by Burko (Eur. J. Phys. 2010 31 L71-7) concerning the energy transferred by transverse waves in a stretched string. (letters and comments)

  9. Space-time topology optimization for one-dimensional wave propagation

    Jensen, Jakob Søndergaard

    2009-01-01

    -dimensional transient wave propagation in an elastic rod with time dependent Young's modulus. By two simulation examples it is demonstrated how dynamic structures can display rich dynamic behavior such as wavenumber/frequency shifts and lack of energy conservation. The optimization method's potential for creating...... structures with novel dynamic behavior is illustrated by a simple example; it is shown that an elastic rod in which the optimized stiffness distribution is allowed to vary in time can be much more efficient in prohibiting wave propagation compared to a static bandgap structure. Optimized designs in form...... of spatio-temporal laminates and checkerboards are generated and discussed. The example lays the foundation for creating designs with more advanced functionalities in future work....

  10. Frequency dependence of localization length of an electromagnetic wave in a one-dimensional system

    Vinogradov, A.P.; Merzlikin, A.M.

    2003-01-01

    It is shown that the existence in the high-frequency limit of the localization length of an electromagnetic wave in a randomly layered system requires the presence of an infinitely large number of layers with different incommensurable optical paths. Moreover, the measure of the layers with optical paths that are multiples of any real number should equal zero. The localization length in the high-frequency limit is determined by the mean value of the layer thickness and impedance distribution only. The scaling behavior L loc (k 0 )∼k 0 -2 is observed only if the mean value tends to zero (corresponding to a delta-correlated process)

  11. B-spline based finite element method in one-dimensional discontinuous elastic wave propagation

    Kolman, Radek; Okrouhlík, Miloslav; Berezovski, A.; Gabriel, Dušan; Kopačka, Ján; Plešek, Jiří

    2017-01-01

    Roč. 46, June (2017), s. 382-395 ISSN 0307-904X R&D Projects: GA ČR(CZ) GAP101/12/2315; GA MŠk(CZ) EF15_003/0000493 Grant - others:AV ČR(CZ) DAAD-16-12; AV ČR(CZ) ETA-15-03 Program:Bilaterální spolupráce; Bilaterální spolupráce Institutional support: RVO:61388998 Keywords : discontinuous elastic wave propagation * B-spline finite element method * isogeometric analysis * implicit and explicit time integration * dispersion * spurious oscillations Subject RIV: BI - Acoustics OBOR OECD: Acoustics Impact factor: 2.350, year: 2016 http://www.sciencedirect.com/science/article/pii/S0307904X17300835

  12. One-dimensional nonlinear theory for rectangular helix traveling-wave tube

    Fu, Chengfang, E-mail: fchffchf@126.com; Zhao, Bo; Yang, Yudong; Ju, Yongfeng [Faculty of Electronic Information Engineering, Huaiyin Institute of Technology, Huai' an 223003 (China); Wei, Yanyu [School of Physical Electronics, University of Electronic and Technology of China, Chengdu 610054 (China)

    2016-08-15

    A 1-D nonlinear theory of a rectangular helix traveling-wave tube (TWT) interacting with a ribbon beam is presented in this paper. The RF field is modeled by a transmission line equivalent circuit, the ribbon beam is divided into a sequence of thin rectangular electron discs with the same cross section as the beam, and the charges are assumed to be uniformly distributed over these discs. Then a method of computing the space-charge field by solving Green's Function in the Cartesian Coordinate-system is fully described. Nonlinear partial differential equations for field amplitudes and Lorentz force equations for particles are solved numerically using the fourth-order Runge-Kutta technique. The tube's gain, output power, and efficiency of the above TWT are computed. The results show that increasing the cross section of the ribbon beam will improve a rectangular helix TWT's efficiency and reduce the saturated length.

  13. Full Equations (FEQ) model for the solution of the full, dynamic equations of motion for one-dimensional unsteady flow in open channels and through control structures

    Franz, Delbert D.; Melching, Charles S.

    1997-01-01

    The Full EQuations (FEQ) model is a computer program for solution of the full, dynamic equations of motion for one-dimensional unsteady flow in open channels and through control structures. A stream system that is simulated by application of FEQ is subdivided into stream reaches (branches), parts of the stream system for which complete information on flow and depth are not required (dummy branches), and level-pool reservoirs. These components are connected by special features; that is, hydraulic control structures, including junctions, bridges, culverts, dams, waterfalls, spillways, weirs, side weirs, and pumps. The principles of conservation of mass and conservation of momentum are used to calculate the flow and depth throughout the stream system resulting from known initial and boundary conditions by means of an implicit finite-difference approximation at fixed points (computational nodes). The hydraulic characteristics of (1) branches including top width, area, first moment of area with respect to the water surface, conveyance, and flux coefficients and (2) special features (relations between flow and headwater and (or) tail-water elevations, including the operation of variable-geometry structures) are stored in function tables calculated in the companion program, Full EQuations UTiLities (FEQUTL). Function tables containing other information used in unsteady-flow simulation (boundary conditions, tributary inflows or outflows, gate settings, correction factors, characteristics of dummy branches and level-pool reservoirs, and wind speed and direction) are prepared by the user as detailed in this report. In the iterative solution scheme for flow and depth throughout the stream system, an interpolation of the function tables corresponding to the computational nodes throughout the stream system is done in the model. FEQ can be applied in the simulation of a wide range of stream configurations (including loops), lateral-inflow conditions, and special features. The

  14. Analysis of wave motion in one-dimensional structures through fast-Fourier-transform-based wavelet finite element method

    Shen, Wei; Li, Dongsheng; Zhang, Shuaifang; Ou, Jinping

    2017-07-01

    This paper presents a hybrid method that combines the B-spline wavelet on the interval (BSWI) finite element method and spectral analysis based on fast Fourier transform (FFT) to study wave propagation in One-Dimensional (1D) structures. BSWI scaling functions are utilized to approximate the theoretical wave solution in the spatial domain and construct a high-accuracy dynamic stiffness matrix. Dynamic reduction on element level is applied to eliminate the interior degrees of freedom of BSWI elements and substantially reduce the size of the system matrix. The dynamic equations of the system are then transformed and solved in the frequency domain through FFT-based spectral analysis which is especially suitable for parallel computation. A comparative analysis of four different finite element methods is conducted to demonstrate the validity and efficiency of the proposed method when utilized in high-frequency wave problems. Other numerical examples are utilized to simulate the influence of crack and delamination on wave propagation in 1D rods and beams. Finally, the errors caused by FFT and their corresponding solutions are presented.

  15. A new high accuracy non-polynomial tension spline method for the solution of one dimensional wave equation in polar co-ordinates

    Venu Gopal

    2014-07-01

    Full Text Available In this paper, we propose a new three-level implicit nine point compact finite difference formulation of O(k2 + h4 based on non-polynomial tension spline approximation in r-direction and finite difference approximation in t-direction for the numerical solution of one dimensional wave equation in polar co-ordinates. We describe the mathematical formulation procedure in details and also discuss the stability of the method. Numerical results are provided to justify the usefulness of the proposed method.

  16. One dimensional P wave velocity structure of the crust beneath west Java and accurate hypocentre locations from local earthquake inversion

    Supardiyono; Santosa, Bagus Jaya

    2012-01-01

    A one-dimensional (1-D) velocity model and station corrections for the West Java zone were computed by inverting P-wave arrival times recorded on a local seismic network of 14 stations. A total of 61 local events with a minimum of 6 P-phases, rms 0.56 s and a maximum gap of 299° were selected. Comparison with previous earthquake locations shows an improvement for the relocated earthquakes. Tests were carried out to verify the robustness of inversion results in order to corroborate the conclusions drawn out from our reasearch. The obtained minimum 1-D velocity model can be used to improve routine earthquake locations and represents a further step toward more detailed seismotectonic studies in this area of West Java.

  17. One dimensional P wave velocity structure of the crust beneath west Java and accurate hypocentre locations from local earthquake inversion

    Supardiyono; Santosa, Bagus Jaya [Physics Department, Faculty of Mathematics and Natural Sciences, State University of Surabaya, Surabaya (Indonesia) and Physics Department, Faculty of Mathematics and Natural Sciences, Sepuluh Nopember Institute of Technology, Surabaya (Indonesia); Physics Department, Faculty of Mathematics and Natural Sciences, Sepuluh Nopember Institute of Technology, Surabaya (Indonesia)

    2012-06-20

    A one-dimensional (1-D) velocity model and station corrections for the West Java zone were computed by inverting P-wave arrival times recorded on a local seismic network of 14 stations. A total of 61 local events with a minimum of 6 P-phases, rms 0.56 s and a maximum gap of 299 Degree-Sign were selected. Comparison with previous earthquake locations shows an improvement for the relocated earthquakes. Tests were carried out to verify the robustness of inversion results in order to corroborate the conclusions drawn out from our reasearch. The obtained minimum 1-D velocity model can be used to improve routine earthquake locations and represents a further step toward more detailed seismotectonic studies in this area of West Java.

  18. Dispersion relations of elastic waves in one-dimensional piezoelectric/piezomagnetic phononic crystal with initial stresses.

    Guo, Xiao; Wei, Peijun

    2016-03-01

    The dispersion relations of elastic waves in a one-dimensional phononic crystal formed by periodically repeating of a pre-stressed piezoelectric slab and a pre-stressed piezomagnetic slab are studied in this paper. The influences of initial stress on the dispersive relation are considered based on the incremental stress theory. First, the incremental stress theory of elastic solid is extended to the magneto-electro-elasto solid. The governing equations, constitutive equations, and boundary conditions of the incremental stresses in a magneto-electro-elasto solid are derived with consideration of the existence of initial stresses. Then, the transfer matrices of a pre-stressed piezoelectric slab and a pre-stressed piezomagnetic slab are formulated, respectively. The total transfer matrix of a single cell in the phononic crystal is obtained by the multiplication of two transfer matrixes related with two adjacent slabs. Furthermore, the Bloch theorem is used to obtain the dispersive equations of in-plane and anti-plane Bloch waves. The dispersive equations are solved numerically and the numerical results are shown graphically. The oblique propagation and the normal propagation situations are both considered. In the case of normal propagation of elastic waves, the analytical expressions of the dispersion equation are derived and compared with other literatures. The influences of initial stresses, including the normal initial stresses and shear initial stresses, on the dispersive relations are both discussed based on the numerical results. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Elastic wave localization in two-dimensional phononic crystals with one-dimensional random disorder and aperiodicity

    Yan Zhizhong; Zhang Chuanzeng; Wang Yuesheng

    2011-01-01

    The band structures of in-plane elastic waves propagating in two-dimensional phononic crystals with one-dimensional random disorder and aperiodicity are analyzed in this paper. The localization of wave propagation is discussed by introducing the concept of the localization factor, which is calculated by the plane-wave-based transfer-matrix method. By treating the random disorder and aperiodicity as the deviation from the periodicity in a special way, three kinds of aperiodic phononic crystals that have normally distributed random disorder, Thue-Morse and Rudin-Shapiro sequence in one direction and translational symmetry in the other direction are considered and the band structures are characterized using localization factors. Besides, as a special case, we analyze the band gap properties of a periodic planar layered composite containing a periodic array of square inclusions. The transmission coefficients based on eigen-mode matching theory are also calculated and the results show the same behaviors as the localization factor does. In the case of random disorders, the localization degree of the normally distributed random disorder is larger than that of the uniformly distributed random disorder although the eigenstates are both localized no matter what types of random disorders, whereas, for the case of Thue-Morse and Rudin-Shapiro structures, the band structures of Thue-Morse sequence exhibit similarities with the quasi-periodic (Fibonacci) sequence not present in the results of the Rudin-Shapiro sequence.

  20. Lamb wave band gaps in one-dimensional radial phononic crystal plates with periodic double-sided corrugations

    Li, Yinggang [School of Mechanical Engineering and State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, 710049 (China); School of Transportation, Wuhan University of Technology, Wuhan 430070 (China); Chen, Tianning [School of Mechanical Engineering and State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, 710049 (China); Wang, Xiaopeng, E-mail: xpwang@mail.xjtu.edu.cn [School of Mechanical Engineering and State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, 710049 (China); Li, Suobin [School of Mechanical Engineering and State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, 710049 (China)

    2015-11-01

    In this paper, we present the theoretical investigation of Lamb wave propagation in one-dimensional radial phononic crystal (RPC) plates with periodic double-sided corrugations. The dispersion relations, the power transmission spectra, and the displacement fields of the eigenmodes are studied by using the finite element method based on two-dimensional axial symmetry models in cylindrical coordinates. Numerical results show that the proposed RPC plates with periodic double-sided corrugations can yield several band gaps with a variable bandwidth for Lamb waves. The formation mechanism of band gaps in the double-sided RPC plates is attributed to the coupling between the Lamb modes and the in-phase and out-phases resonant eigenmodes of the double-sided corrugations. We investigate the evolution of band gaps in the double-sided RPC plates with the corrugation heights on both sides arranged from an asymmetrical distribution to a symmetrical distribution gradually. Significantly, with the introduction of symmetric double-sided corrugations, the antisymmetric Lamb mode is suppressed by the in-phase resonant eigenmodes of the double-sided corrugations, resulting in the disappearance of the lowest band gap. Furthermore, the effects of the geometrical parameters on the band gaps are further explored numerically.

  1. Superconductor to spin-density-wave transition in quasi-one-dimensional metals with repulsive anisotropic interaction

    Rozhkov, A.V.

    2007-01-01

    A mechanism for superconductivity in a quasi-one-dimensional system with repulsive Ising-anisotropic interaction is studied. The Ising anisotropy opens the gap Δ s in the spin sector of the model. This gap allows the triplet superconductivity and the spin-density wave as the only broken symmetry phases. These phases are separated by the first order transition. The transport properties of the system are investigated in different parts of the phase diagram. The calculation of DC conductivity σ(T) in the high-temperature phase shows that the function σ(T) cannot be used as an indicator of a superconducting ground state: even if σ(T) is a decreasing function at high temperature, yet, the ground state may be insulating spin-density wave; the opposite is also true. The calculation of the spin dynamical structure factor S zz (q, ω) demonstrates that it is affected by the superconducting phase transition in a qualitative fashion: below T c the structure factor develops a gap with a coherent excitation inside this gap

  2. Nonlinear wave-packet dynamics for a generic one-dimensional time-independent system and its application to the hydrogen atom in a weak magnetic field

    Dupret, K.; Delande, D.

    1996-01-01

    We study the time propagation of an initially localized wave packet for a generic one-dimensional time-independent system, using the open-quote open-quote nonlinear wave-packet dynamics close-quote close-quote [S. Tomsovic and E. J. Heller, Phys. Rev. Lett. 67, 664 (1991)], a semiclassical approximation using a local linearization of the wave packet in the vicinity of classical reference trajectories. Several reference trajectories are needed to describe the behavior of the full wave packet. The introduction of action-angle variables allows us to obtain a simple analytic expression for the autocorrelation function, and to show that a universal behavior (quantum collapses, quantum revivals, etc.) is obtained via interferences between the reference trajectories. A connection with the standard WKB approach is established. Finally, we apply the nonlinear wave-packet dynamics to the case of the hydrogen atom in a weak magnetic field, and show that the semiclassical expressions obtained by nonlinear wave-packet dynamics are extremely accurate. copyright 1996 The American Physical Society

  3. Exchange correlation effects on plasmons and on charge-density wave instability in narrow-band quasi-one-dimensional metals

    Nobile, A.; Tosatti, E.

    1979-05-01

    The coexistence of tight-binding and exchange-correlation effects inside each chain of a model quasi-one-dimensional metal, on both plasmon and charge density wave properties have been studied. The results, while in qualitative agreement with other treatments of the problem at long wavelengths, indicate a strong tendency for plasmons to turn into excitons at larger momenta, and to exhibit an ''excitonic'' charge-density wave instability at k approximately 2ksub(F). The nature of the plasmon branches and of the excitonic charge distortion is examined. Relevance to existing quasi-one-dimensional materials is also discussed. (author)

  4. Reversible one-dimensional cellular automata with one of the two Welch indices equal to 1 and full shifts

    Mora, Juan Carlos Seck Tuoh; Hernandez, Manuel Gonzalez; Vergara, Sergio V Chapa

    2003-01-01

    Reversible cellular automata are invertible discrete dynamical systems which have been widely studied both for analysing interesting theoretical questions and for obtaining relevant practical applications, for instance, simulating invertible natural systems or implementing data coding devices. An important problem in the theory of reversible automata is to know how the local behaviour which is not invertible is able to yield a reversible global one. In this sense, symbolic dynamics plays an important role for obtaining an adequate representation of a reversible cellular automaton. In this paper we prove the equivalence between a reversible automaton where the ancestors only differ at one side (technically with one of the two Welch indices equal to 1) and a full shift. We represent any reversible automaton by a de Bruijn diagram, and we characterize the way in which the diagram produces an evolution formed by undefined repetitions of two states. By means of amalgamations, we prove that there is always a way of transforming a de Bruijn diagram into the full shift. Finally, we provide an example illustrating the previous results

  5. Reversible one-dimensional cellular automata with one of the two Welch indices equal to 1 and full shifts

    Mora, Juan Carlos Seck Tuoh [Centro de Investigacion Avanzada en Ingenieria Industrial, Universidad Autonoma del Estado de Hidalgo, Carr Pachuca-Tulancingo Km 4.5, 42020 Pachuca (Mexico); Hernandez, Manuel Gonzalez [Centro de Investigacion Avanzada en Ingenieria Industrial, Universidad Autonoma del Estado de Hidalgo, Carr Pachuca-Tulancingo Km 4.5, 42020 Pachuca (Mexico); Vergara, Sergio V Chapa [Depto de Ingenieria Electrica, Seccion Computacion, Centro de Investigacion y de Estudios Avanzados, Instituto Politecnico Nacional, Av IPN 2508, Col San Pedro Zacatenco, 07300 DF (Mexico)

    2003-07-25

    Reversible cellular automata are invertible discrete dynamical systems which have been widely studied both for analysing interesting theoretical questions and for obtaining relevant practical applications, for instance, simulating invertible natural systems or implementing data coding devices. An important problem in the theory of reversible automata is to know how the local behaviour which is not invertible is able to yield a reversible global one. In this sense, symbolic dynamics plays an important role for obtaining an adequate representation of a reversible cellular automaton. In this paper we prove the equivalence between a reversible automaton where the ancestors only differ at one side (technically with one of the two Welch indices equal to 1) and a full shift. We represent any reversible automaton by a de Bruijn diagram, and we characterize the way in which the diagram produces an evolution formed by undefined repetitions of two states. By means of amalgamations, we prove that there is always a way of transforming a de Bruijn diagram into the full shift. Finally, we provide an example illustrating the previous results.

  6. Investigations on flexural wave propagation and attenuation in a modified one-dimensional acoustic black hole using a laser excitation technique

    Ji, Hongli; Luo, Jing; Qiu, Jinhao; Cheng, Li

    2018-05-01

    Acoustic Black Holes (ABHs), as a new type of passive structure for vibration damping enhancement and noise attenuation, have been drawing increasing attentions of many researchers. Due to the difficulty in manufacturing the sharp edges required by the ABH structures, it is important to understand the wave propagation and attenuation process in the presence of damping layers in non-ideal ABHs with a truncated edge. In this paper, an analytical expression of the wave reflection coefficient in a modified one-dimensional ABH is derived and a time-domain experimental method based on a laser excitation technique is used to visualize the wave propagation. In the experimental studies, the flexural waves in the ABH were excited by a scanning pulse laser and measured by a Laser Doppler Vibrometer (LDV). The incident wave and reflected wave were separated from the measured original wave field and the decrease of the wave velocity in the ABH was exhibited. The reflection coefficient was calculated from the ratio of the amplitude of the reflected wave to that of the incident wave for different ABH parameters and different thicknesses of the damping layer. The measured reflection coefficients were used to identify the unknown coefficients in the theoretical formula. The results confirm that there exists an optimal thickness for the damping layer, which leads to the minimum wave reflection. Based on the laser-induced visualization technique and various signal processing and feature extraction methods, the entire process of the wave propagation in a non-ideal one-dimensional ABH structure can be visualized and scrutinized.

  7. Full evaporation dynamic headspace in combination with selectable one-dimensional/two-dimensional gas chromatography-mass spectrometry for the determination of suspected fragrance allergens in cosmetic products.

    Devos, Christophe; Ochiai, Nobuo; Sasamoto, Kikuo; Sandra, Pat; David, Frank

    2012-09-14

    Suspected fragrance allergens were determined in cosmetic products using a combination of full evaporation-dynamic headspace (FEDHS) with selectable one-dimensional/two-dimensional GC-MS. The full evaporation dynamic headspace approach allows the non-discriminating extraction and injection of both apolar and polar fragrance compounds, without contamination of the analytical system by high molecular weight non-volatile matrix compounds. The method can be applied to all classes of cosmetic samples, including water containing matrices such as shower gels or body creams. In combination with selectable (1)D/(2)D GC-MS, consisting of a dedicated heart-cutting GC-MS configuration using capillary flow technology (CFT) and low thermal mass GC (LTM-GC), a highly flexible and easy-to-use analytical solution is offered. Depending on the complexity of the perfume fraction, analyses can be performed in one-dimensional GC-MS mode or in heart-cutting two-dimensional GC-MS mode, without the need of hardware reconfiguration. The two-dimensional mode with independent temperature control of the first and second dimension column is especially useful to confirm the presence of detected allergen compounds when mass spectral deconvolution is not possible. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Quantitative one-dimensional thermal-wave cavity measurements of fluid thermophysical properties through equivalence studies with three-dimensional geometries

    Matvienko, Anna; Mandelis, Andreas

    2006-01-01

    The thermal-wave field in a photopyroelectric thermal-wave cavity was calculated with two theoretical approaches: a computationally straightforward, conventional, one-dimensional approach and a three-dimensional experimentally more realistic approach. The calculations show that the dimensionality of the thermal-wave field in the cavity depends on the lateral heat transfer boundary conditions and the relation between the beam size of the laser impinging on the thermal-wave generating metallic film and the diameter of the film itself. The theoretical calculations and the experimental data on the photopyroelectric signal in the cavity were compared. The study resulted in identifying ranges of heat transfer rates, beam sizes, and cavity radii for which accurate quantitative measurements of the thermal diffusivity of intracavity fluids can be made within the far simpler, but only approximate, one-dimensional approach conventionally adopted by users of thermal-wave cavities. It was shown that the major parameters affecting the dimensionality of thermal-wave cavities are the laser beam spot size and the Biot number of the medium comprising the sidewalls of the (cylindrical) cavity

  9. Exact pairing correlations in one-dimensional trapped fermions with stochastic mean-field wave-functions

    Juillet, O.; Gulminelli, F. [Caen Univ., Lab. de Physique Corpusculaire (LPC/ENSICAEN), 14 (France); Chomaz, Ph. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

    2003-11-01

    The canonical thermodynamic properties of a one-dimensional system of interacting spin-1/2 fermions with an attractive zero-range pseudo-potential are investigated within an exact approach. The density operator is evaluated as the statistical average of dyadics formed from a stochastic mean-field propagation of independent Slater determinants. For an harmonically trapped Fermi gas and for fermions confined in a 1D-like torus, we observe the transition to a quasi-BCS state with Cooper-like momentum correlations and an algebraic long-range order. For few trapped fermions in a rotating torus, a dominant superfluid component with quantized circulation can be isolated. (author)

  10. Sol-hydrothermal synthesis and optical properties of Eu3+, Tb(3+)-codoped one-dimensional strontium germanate full color nano-phosphors.

    Lin, Liangwu; Sun, Xinyuan; Jiang, Yao; He, Yuehui

    2013-12-21

    Novel near-UV and blue excited Eu(3+), Tb(3+)-codoped one dimensional strontium germanate full-color nano-phosphors have been successfully synthesized by a simple sol-hydrothermal method. The morphologies, internal structures, chemical constitution and optical properties of the resulting samples were characterized using FE-SEM, TEM, HRTEM, EDS, XRD, FTIR, XPS, PL and PLE spectroscopy and luminescence decay curves. The results suggested that the obtained Eu(3+), Tb(3+)-codoped strontium germanate nanowires are single crystal nanowires with a diameter ranging from 10 to 80 nm, average diameter of around 30 nm and the length ranging from tens to hundreds micrometers. The results of PL and PLE spectra indicated that the Eu(3+), Tb(3+)-codoped single crystal strontium germanate nanowires showed an intensive blue, blue-green, green, orange and red or green, orange and red light emission under excitation at 350-380 nm and 485 nm, respectively, which may attributed to the coexistent Eu(3+), Eu(2+) and Tb(3+) ions, and the defects located in the strontium germanate nanowires. A possible mechanism of energy transfer among the host, Eu(3+) and Tb(3+) ions was proposed. White-emission can be realized in a single-phase strontium germanate nanowire host by codoping with Tb(3+) and Eu(3+) ions. The Eu(3+), Tb(3+)-codoped one-dimensional strontium germanate full-color nano-phosphors have superior stability under electron bombardment. Because of their strong PL intensity, good CIE chromaticity and stability, the novel 1D strontium germanate full-color nano-phosphors have potential applications in W-LEDs.

  11. Numerical investigation of the propagation of elastic wave modes in a one-dimensional phononic crystal plate coated on a uniform substrate

    Hou Zhilin; Assouar, Badreddine M

    2009-01-01

    The propagation of wave modes in a two-layer free standing plate composed of a one-dimensional phononic crystal (PC) thin layer coated on a uniform substrate was investigated numerically by the modified plane wave expansion method. The band structures of the system with different thicknesses of the substrate were calculated. The numerical result showed that Bragg scattering by the periodic structure in a PC and wave scattering by the free surface could be coupled to each other with an added substrate layer. The properties of the confined modes in such a system, for example, the Love-wave-like mode, the confined PC mode (which is localized mainly in the PC layer) and the surface mode on the free surface of the substrate layer, were investigated.

  12. Existence, stability, and dynamics of harmonically trapped one-dimensional multi-component solitary waves: The near-linear limit

    Xu, H.; Kevrekidis, P. G.; Kapitula, T.

    2017-06-01

    In the present work, we consider a variety of two-component, one-dimensional states in nonlinear Schrödinger equations in the presence of a parabolic trap, inspired by the atomic physics context of Bose-Einstein condensates. The use of Lyapunov-Schmidt reduction methods allows us to identify persistence criteria for the different families of solutions which we classify as (m, n), in accordance with the number of zeros in each component. Upon developing the existence theory, we turn to a stability analysis of the different configurations, using the Krein signature and the Hamiltonian-Krein index as topological tools identifying the number of potentially unstable eigendirections for each branch. A perturbation expansion for the eigenvalue problems associated with nonlinear states found near the linear limit permits us to obtain explicit asymptotic expressions for the eigenvalues. Finally, when the states are found to be unstable, typically by virtue of Hamiltonian Hopf bifurcations, their dynamics is studied in order to identify the nature of the respective instability. The dynamics is generally found to lead to a vibrational evolution over long time scales.

  13. Superfluidity breakdown of periodic matter waves in quasi-one-dimensional annular traps via resonant scattering with moving defects

    Yulin, A.V.; Bludov, Yu.V.; Konotop, V. V.; Kuzmiak, Vladimír; Salerno, M.

    2013-01-01

    Roč. 87, č. 3 (2013) ISSN 1050-2947 R&D Projects: GA MŠk LH12009 Institutional support: RVO:67985882 Keywords : Superfluidity * Bose-Einstein condensates * Matter Waves Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.991, year: 2013

  14. Wave function of an electron infinitely moving in the field of a one-dimensional layered structure

    Khachatrian, A.Zh.; Andreasyan, A.G.; Mgerian, G.G.; Badalyan, V.D.

    2003-01-01

    A method for finding the wave function of an electron infinitely moving in the field of an arbitrary layered structure bordered on both sides with two different semi infinite media is proposed. It is shown that this problem in the general form can be reduced to the solution of some system of linear finite-difference equations. The proposed approach is discussed in detail for the case of a periodic structure

  15. On interaction of P-waves with one-dimensional photonic crystal consisting of weak conducting matter and transparent dielectric layers

    Yushkanov, A. A.; Zverev, N. V.

    2018-03-01

    An influence of quantum and spatial dispersion properties of the non-degenerate electron plasma on the interaction of electromagnetic P-waves with one-dimensional photonic crystal consisting of conductor with low carrier electron density and transparent dielectric matter, is studied numerically. It is shown that at the frequencies of order of the plasma frequency and at small widths of the conducting and dielectric layers of the photonic crystal, optical coefficients in the quantum non-degenerate plasma approach differ from the coefficients in the classical electron gas approach. And also, at these frequencies one observes a temperature dependence of the optical coefficients.

  16. Frequency Dependencies of the Exchange Spin Wave Reflection Coefficient on a One-Dimensional Magnon Crystal with Complex Interfaces

    Serhii O. Reshetniak

    2017-09-01

    Conclusions. It is shown that the frequency dependencies are periodic, points of full transmission and areas, full of reflection. Decreasing exchange parameter value in interface causes the increase of reflectance coefficient. Changing the material parameters we get the necessary intensity value of the reflection coefficient depending on the frequency at a constant value of the external magnetic field.

  17. Band dependence of charge density wave in quasi-one-dimensional Ta2NiSe7 probed by orbital magnetoresistance

    He, Jiaming; Zhang, Yiran; Wen, Libin; Yang, Yusen; Liu, Jinyu; Wu, Yueshen; Lian, Hailong; Xing, Hui; Wang, Shun; Mao, Zhiqiang; Liu, Ying

    2017-07-01

    Ta2NiSe7 is a quasi-one-dimensional (quasi-1D) transition-metal chalcogenide with Ta and Ni chain structures. An incommensurate charge-density wave (CDW) in this quasi-1D structure was well studied previously using tunnelling spectrum, X-ray, and electron diffraction, whereas its transport property and the relation to the underlying electronic states remain to be explored. Here, we report our results of the magnetoresistance (MR) on Ta2NiSe7. A breakdown of Kohler's rule is found upon entering the CDW state. Concomitantly, a clear change in curvature in the field dependence of MR is observed. We show that the curvature change is well described by the two-band orbital MR, with the hole density being strongly suppressed in the CDW state, indicating that the p orbitals from Se atoms dominate the change in transport through CDW transition.

  18. Spin wave energy dispersion in KCuF/sub 3/: a nearly one-dimensional spin-1/2 antiferromagnet. [4. 7/sup 0/K

    Hutchings, M T; Ikeda, H; Milne, J M

    1979-09-28

    Using inelastic neutron scattering techniques, the spin wave energy dispersion in the (010) plane of the distorted perovskite KCuF/sub 3/, which exhibits many magnetic properties of the spin-1/2 one-dimensional antiferromagnet, has been investigated at 4.7 K (T/sub N/ = 39 K). The measurements confirm the very strong exchange interaction between the spins in the (001) direction, and show that in this direction the expression for the excitation energies of the spin-1/2 antiferromagnetic chain given by J des Cloizeaux and J J Pearson is obeyed. The exchange interaction between these chains is found to be only 1.6% of that within the chains.

  19. Myth and One-Dimensionality

    William Hansen

    2017-12-01

    Full Text Available A striking difference between the folk-narrative genres of legend and folktale is how the human characters respond to supernatural, otherworldly, or uncanny beings such as ghosts, gods, dwarves, giants, trolls, talking animals, witches, and fairies. In legend the human actors respond with fear and awe, whereas in folktale they treat such beings as if they were ordinary and unremarkable. Since folktale humans treat all characters as belonging to a single realm, folklorists have described the world of the folktale as one-dimensional, in contrast to the two-dimensionality of the legend. The present investigation examines dimensionality in the third major genre of folk narrative: myth. Using the Greek and Hebrew myths of primordial paradise as sample narratives, the present essay finds—surprisingly—that the humans in these stories respond to the otherworldly one-dimensionally, as folktale characters do, and suggests an explanation for their behavior that is peculiar to the world of myth.

  20. Full-wave solution of short impulses in inhomogeneous plasma

    Ferencz, Orsolya E.

    2005-01-01

    In this paper the problem of real impulse propagation in arbitrarily inhomogeneous media will be presented on a fundamentally new, general, theoretical way. The general problem of wave propagation of monochromatic signals in inhomogeneous media was enlightened. The earlier theoretical models for spatial inhomogeneities have some errors regarding the structure of the resultant signal originated from backward and forward propagating parts. The application of the method of inhomogeneous basic modes (MIBM) and the complete full-wave solution of arbitrarily shaped non-monochromatic plane waves in plasmas made it possible to obtain a better description of the problem, on a fully analytical way, directly from Maxwell's equations. The model investigated in this paper is inhomogeneous of arbitrary order (while the wave pattern can exist), anisotropic (magnetized), linear, cold plasma, in which the gradient of the one-dimensional spatial inhomogeneity is parallel to the direction of propagation. (author)

  1. One-Dimensionality and Whiteness

    Calderon, Dolores

    2006-01-01

    This article is a theoretical discussion that links Marcuse's concept of one-dimensional society and the Great Refusal with critical race theory in order to achieve a more robust interrogation of whiteness. The author argues that in the context of the United States, the one-dimensionality that Marcuse condemns in "One-Dimensional Man" is best…

  2. Expansion of a quantum wave packet in a one-dimensional disordered potential in the presence of a uniform bias force

    Crosnier de Bellaistre, C.; Trefzger, C.; Aspect, A.; Georges, A.; Sanchez-Palencia, L.

    2018-01-01

    We study numerically the expansion dynamics of an initially confined quantum wave packet in the presence of a disordered potential and a uniform bias force. For white-noise disorder, we find that the wave packet develops asymmetric algebraic tails for any ratio of the force to the disorder strength. The exponent of the algebraic tails decays smoothly with that ratio and no evidence of a critical behavior on the wave density profile is found. Algebraic localization features a series of critical values of the force-to-disorder strength where the m th position moment of the wave packet diverges. Below the critical value for the m th moment, we find fair agreement between the asymptotic long-time value of the m th moment and the predictions of diagrammatic calculations. Above it, we find that the m th moment grows algebraically in time. For correlated disorder, we find evidence of systematic delocalization, irrespective to the model of disorder. More precisely, we find a two-step dynamics, where both the center-of-mass position and the width of the wave packet show transient localization, similar to the white-noise case, at short time and delocalization at sufficiently long time. This correlation-induced delocalization is interpreted as due to the decrease of the effective de Broglie wavelength, which lowers the effective strength of the disorder in the presence of finite-range correlations.

  3. Stability of Planar Rarefaction Wave to 3D Full Compressible Navier-Stokes Equations

    Li, Lin-an; Wang, Teng; Wang, Yi

    2018-05-01

    We prove time-asymptotic stability toward the planar rarefaction wave for the three-dimensional full, compressible Navier-Stokes equations with the heat-conductivities in an infinite long flat nozzle domain {R × T^2} . Compared with one-dimensional case, the proof here is based on our new observations on the cancellations on the flux terms and viscous terms due to the underlying wave structures, which are crucial for overcoming the difficulties due to the wave propagation in the transverse directions x 2 and x 3 and its interactions with the planar rarefaction wave in x 1 direction.

  4. QUASI-ONE DIMENSIONAL CLASSICAL FLUIDS

    J.K.Percus

    2003-01-01

    Full Text Available We study the equilibrium statistical mechanics of simple fluids in narrow pores. A systematic expansion is made about a one-dimensional limit of this system. It starts with a density functional, constructed from projected densities, which depends upon projected one and two-body potentials. The nature of higher order corrections is discussed.

  5. Remarks for one-dimensional fractional equations

    Massimiliano Ferrara

    2014-01-01

    Full Text Available In this paper we study a class of one-dimensional Dirichlet boundary value problems involving the Caputo fractional derivatives. The existence of infinitely many solutions for this equations is obtained by exploiting a recent abstract result. Concrete examples of applications are presented.

  6. RELATIVISTIC MAGNETOHYDRODYNAMICS: RENORMALIZED EIGENVECTORS AND FULL WAVE DECOMPOSITION RIEMANN SOLVER

    Anton, Luis; MartI, Jose M; Ibanez, Jose M; Aloy, Miguel A.; Mimica, Petar; Miralles, Juan A.

    2010-01-01

    We obtain renormalized sets of right and left eigenvectors of the flux vector Jacobians of the relativistic MHD equations, which are regular and span a complete basis in any physical state including degenerate ones. The renormalization procedure relies on the characterization of the degeneracy types in terms of the normal and tangential components of the magnetic field to the wave front in the fluid rest frame. Proper expressions of the renormalized eigenvectors in conserved variables are obtained through the corresponding matrix transformations. Our work completes previous analysis that present different sets of right eigenvectors for non-degenerate and degenerate states, and can be seen as a relativistic generalization of earlier work performed in classical MHD. Based on the full wave decomposition (FWD) provided by the renormalized set of eigenvectors in conserved variables, we have also developed a linearized (Roe-type) Riemann solver. Extensive testing against one- and two-dimensional standard numerical problems allows us to conclude that our solver is very robust. When compared with a family of simpler solvers that avoid the knowledge of the full characteristic structure of the equations in the computation of the numerical fluxes, our solver turns out to be less diffusive than HLL and HLLC, and comparable in accuracy to the HLLD solver. The amount of operations needed by the FWD solver makes it less efficient computationally than those of the HLL family in one-dimensional problems. However, its relative efficiency increases in multidimensional simulations.

  7. Source Estimation by Full Wave Form Inversion

    Sjögreen, Björn [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Center for Applied Scientific Computing; Petersson, N. Anders [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Center for Applied Scientific Computing

    2013-08-07

    Given time-dependent ground motion recordings at a number of receiver stations, we solve the inverse problem for estimating the parameters of the seismic source. The source is modeled as a point moment tensor source, characterized by its location, moment tensor components, the start time, and frequency parameter (rise time) of its source time function. In total, there are 11 unknown parameters. We use a non-linear conjugate gradient algorithm to minimize the full waveform misfit between observed and computed ground motions at the receiver stations. An important underlying assumption of the minimization problem is that the wave propagation is accurately described by the elastic wave equation in a heterogeneous isotropic material. We use a fourth order accurate finite difference method, developed in [12], to evolve the waves forwards in time. The adjoint wave equation corresponding to the discretized elastic wave equation is used to compute the gradient of the misfit, which is needed by the non-linear conjugated minimization algorithm. A new source point moment source discretization is derived that guarantees that the Hessian of the misfit is a continuous function of the source location. An efficient approach for calculating the Hessian is also presented. We show how the Hessian can be used to scale the problem to improve the convergence of the non-linear conjugated gradient algorithm. Numerical experiments are presented for estimating the source parameters from synthetic data in a layer over half-space problem (LOH.1), illustrating rapid convergence of the proposed approach.

  8. One dimensional reactor core model

    Kostadinov, V.; Stritar, A.; Radovo, M.; Mavko, B.

    1984-01-01

    The one dimensional model of neutron dynamic in reactor core was developed. The core was divided in several axial nodes. The one group neutron diffusion equation for each node is solved. Feedback affects of fuel and water temperatures is calculated. The influence of xenon, boron and control rods is included in cross section calculations for each node. The system of equations is solved implicitly. The model is used in basic principle Training Simulator of NPP Krsko. (author)

  9. Full wave simulations of lower hybrid wave propagation in tokamaks

    Wright, J. C.; Bonoli, P. T.; Phillips, C. K.; Valeo, E.; Harvey, R. W.

    2009-01-01

    Lower hybrid (LH) waves have the attractive property of damping strongly via electron Landau resonance on relatively fast tail electrons at (2.5-3)xv te , where v te ≡ (2T e /m e ) 1/2 is the electron thermal speed. Consequently these waves are well-suited to driving current in the plasma periphery where the electron temperature is lower, making LH current drive (LHCD) a promising technique for off-axis (r/a≥0.60) current profile control in reactor grade plasmas. Established techniques for computing wave propagation and absorption use WKB expansions with non-Maxwellian self-consistent distributions.In typical plasma conditions with electron densities of several 10 19 m -3 and toroidal magnetic fields strengths of 4 Telsa, the perpendicular wavelength is of the order of 1 mm and the parallel wavelength is of the order of 1 cm. Even in a relatively small device such as Alcator C-Mod with a minor radius of 22 cm, the number of wavelengths that must be resolved requires large amounts of computational resources for the full wave treatment. These requirements are met with a massively parallel version of the TORIC full wave code that has been adapted specifically for the simulation of LH waves [J. C. Wright, et al., Commun. Comput. Phys., 4, 545 (2008), J. C. Wright, et al., Phys. Plasmas 16 July (2009)]. This model accurately represents the effects of focusing and diffraction that occur in LH propagation. It is also coupled with a Fokker-Planck solver, CQL3D, to provide self-consistent distribution functions for the plasma dielectric as well as a synthetic hard X-ray (HXR) diagnostic for direct comparisons with experimental measurements of LH waves.The wave solutions from the TORIC-LH zero FLR model will be compared to the results from ray tracing from the GENRAY/CQL3D code via the synthetic HXR diagnostic and power deposition.

  10. One dimensional model for polytypes

    Rosato, A.

    1979-01-01

    The general expression for the dispersion relation for a polyatomic one dimensional crystal obtained by the Laplace Transform Method is applied to materials with the fcc and hcp structures, both consisting of close-packed planes of atoms with the stacking sequence of plane ABC/ABC... and AB/AB... respectively. The expression is also applied to polytypes, that is materials caracterized by a stacking sequence with longer repeat unit. The effective mass is cast in a condensed form useful for further calculations. The results from this simple model are only qualitative. (Author) [pt

  11. The relationship between the local temperature and the local heat flux within a one-dimensional semi-infinite domain of heat wave propagation

    Kulish Vladimir V.

    2003-01-01

    Full Text Available The relationship between the local temperature and the local heat flux has been established for the homogeneous hyperbolic heat equation. This relationship has been written in the form of a convolution integral involving the modified Bessel functions. The scale analysis of the hyperbolic energy equation has been performed and the dimensionless criterion for the mode of energy transport, similar to the Reynolds criterion for the flow regimes, has been proposed. Finally, the integral equation, relating the local temperature and the local heat flux, has been solved numerically for those processes of surface heating whose time scale is of the order of picoseconds.

  12. One-dimensional plasma simulation studies

    Friberg, Ari; Virtamo, Jorma

    1976-01-01

    Some basic plasma phenomena are studied by a one-dimensional electrostatic simulation code. A brief description of the code and its application to a test problem is given. The experiments carried out include Landau damping of an excited wave, particle retardation by smoothed field and beam-plasma instability. In each case, the set-up of the experiment is described and the results are compared with theoretical predictions. In the theoretical discussions, the oscillatory behaviour found in the Landau damping experiment is explained, an explicit formula for the particle retardation rate is derived and a rudimentary picture of the beam-plasma instability in terms of quasilinear theory is given. (author)

  13. One-dimensional hypersonic phononic crystals.

    Gomopoulos, N; Maschke, D; Koh, C Y; Thomas, E L; Tremel, W; Butt, H-J; Fytas, G

    2010-03-10

    We report experimental observation of a normal incidence phononic band gap in one-dimensional periodic (SiO(2)/poly(methyl methacrylate)) multilayer film at gigahertz frequencies using Brillouin spectroscopy. The band gap to midgap ratio of 0.30 occurs for elastic wave propagation along the periodicity direction, whereas for inplane propagation the system displays an effective medium behavior. The phononic properties are well captured by numerical simulations. The porosity in the silica layers presents a structural scaffold for the introduction of secondary active media for potential coupling between phonons and other excitations, such as photons and electrons.

  14. Structural response analysis of very large floating structures in waves using one-dimensional finite element model; Ichijigen yugen yoso model ni yoru choogata futai no harochu kozo oto kaiseki

    Fujikubo, M.; Yao, T.; Oida, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1996-12-31

    Formulation was made on a one-dimensional beam finite element which is effective in analyzing structural response of very large floating structures by modeling them on beams on an elastic foundation. This element allows strict solution of vibration response in the beams on the elastic foundation to be calculated efficiently for a case where mass and rigidity change in the longitudinal direction. This analysis method was used to analyze structural response of a large pontoon-type floating structure to investigate mass in the end part for the structural response and the effect of decay while passing the structure. With a pontoon-type floating structure, reduction in bends and bending stress in the end part of the floating structure is important in designing the structure. Reducing the mass in the end part is effective as a means to avoid resonance in these responses and reduce the responses. Increase in rigidity of a floating structure shifts the peak in quasi-static response to lower frequency side, and reduces response in resonance, hence it is advantageous for improving the response. Since incident waves decay while passing through the floating structure, response in the lower wave side decreases. The peak frequency in the quasi-static response also decreases at the end part of the structure in the upper wave side due to decay in wave force. 7 refs., 11 figs., 1 tab.

  15. Structural response analysis of very large floating structures in waves using one-dimensional finite element model; Ichijigen yugen yoso model ni yoru choogata futai no harochu kozo oto kaiseki

    Fujikubo, M; Yao, T; Oida, H [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1997-12-31

    Formulation was made on a one-dimensional beam finite element which is effective in analyzing structural response of very large floating structures by modeling them on beams on an elastic foundation. This element allows strict solution of vibration response in the beams on the elastic foundation to be calculated efficiently for a case where mass and rigidity change in the longitudinal direction. This analysis method was used to analyze structural response of a large pontoon-type floating structure to investigate mass in the end part for the structural response and the effect of decay while passing the structure. With a pontoon-type floating structure, reduction in bends and bending stress in the end part of the floating structure is important in designing the structure. Reducing the mass in the end part is effective as a means to avoid resonance in these responses and reduce the responses. Increase in rigidity of a floating structure shifts the peak in quasi-static response to lower frequency side, and reduces response in resonance, hence it is advantageous for improving the response. Since incident waves decay while passing through the floating structure, response in the lower wave side decreases. The peak frequency in the quasi-static response also decreases at the end part of the structure in the upper wave side due to decay in wave force. 7 refs., 11 figs., 1 tab.

  16. Finite-temperature coupled-cluster, many-body perturbation, and restricted and unrestricted Hartree-Fock study on one-dimensional solids: Luttinger liquids, Peierls transitions, and spin- and charge-density waves.

    Hermes, Matthew R; Hirata, So

    2015-09-14

    One-dimensional (1D) solids exhibit a number of striking electronic structures including charge-density wave (CDW) and spin-density wave (SDW). Also, the Peierls theorem states that at zero temperature, a 1D system predicted by simple band theory to be a metal will spontaneously dimerize and open a finite fundamental bandgap, while at higher temperatures, it will assume the equidistant geometry with zero bandgap (a Peierls transition). We computationally study these unique electronic structures and transition in polyyne and all-trans polyacetylene using finite-temperature generalizations of ab initio spin-unrestricted Hartree-Fock (UHF) and spin-restricted coupled-cluster doubles (CCD) theories, extending upon previous work [He et al., J. Chem. Phys. 140, 024702 (2014)] that is based on spin-restricted Hartree-Fock (RHF) and second-order many-body perturbation (MP2) theories. Unlike RHF, UHF can predict SDW as well as CDW and metallic states, and unlike MP2, CCD does not diverge even if the underlying RHF reference wave function is metallic. UHF predicts a gapped SDW state with no dimerization at low temperatures, which gradually becomes metallic as the temperature is raised. CCD, meanwhile, confirms that electron correlation lowers the Peierls transition temperature. Furthermore, we show that the results from all theories for both polymers are subject to a unified interpretation in terms of the UHF solutions to the Hubbard-Peierls model using different values of the electron-electron interaction strength, U/t, in its Hamiltonian. The CCD wave function is shown to encompass the form of the exact solution of the Tomonaga-Luttinger model and is thus expected to describe accurately the electronic structure of Luttinger liquids.

  17. Specificities of one-dimensional dissipative magnetohydrodynamics

    Popov, P. V., E-mail: popov.pv@mipt.ru [National Research Center Kurchatov Institute (Russian Federation)

    2016-11-15

    One-dimensional dynamics of a plane slab of cold (β ≪ 1) isothermal plasma accelerated by a magnetic field is studied in terms of the MHD equations with a finite constant conductivity. The passage to the limit β → 0 is analyzed in detail. It is shown that, at β = 0, the character of the solution depends substantially on the boundary condition for the electric field at the inner plasma boundary. The relationship between the boundary condition for the pressure at β > 0 and the conditions for the electric field at β = 0 is found. The stability of the solution against one-dimensional longitudinal perturbations is analyzed. It is shown that, in the limit β → 0, the stationary solution is unstable if the time during which the acoustic wave propagates across the slab is longer than the time of magnetic field diffusion. The growth rate and threshold of instability are determined, and results of numerical simulation of its nonlinear stage are presented.

  18. Numerical experiment for nonlinear full-wave tomography. 3; Hisenkei full wave tomography no suchi jikken

    Tsuchiya, T [Dia Consultants Company, Tokyo (Japan)

    1996-10-01

    Nonlinear full-wave tomography (FWT) is under investigation to improve the estimation accuracy of Vp/Vs distributions. Full-wave tomography is one of the underground structure exploration methods mainly using Tarantola`s nonlinear local optimization method (LOM). Numerical experiment for FWT was carried out assuming relatively weak nonlinear underground structure. In the case of inversion by local optimization method, adequate preconditioning is important. Utilization of geological information is also effective in estimating low-frequency components of a model. As far as data are obtained under proper observation arrangement, even in actual field, precise estimation of Vp/Vs distributions is possible by FWT using explosion in a hole as wave source. In full-wave tomography, selection of observation arrangement is essential for both Vp and Vs. However, the proper arrangement is different between Vp and Vs. Approach to different analyses for Vp and Vs is also necessary by using only proper data for Vp and Vs among obtained data sets. 4 figs.

  19. Finite-temperature second-order many-body perturbation and Hartree–Fock theories for one-dimensional solids: An application to Peierls and charge-density-wave transitions in conjugated polymers

    He, Xiao; Ryu, Shinsei; Hirata, So

    2014-01-01

    Finite-temperature extensions of ab initio Gaussian-basis-set spin-restricted Hartree–Fock (HF) and second-order many-body perturbation (MP2) theories are implemented for infinitely extended, periodic, one-dimensional solids and applied to the Peierls and charge-density-wave (CDW) transitions in polyyne and all-trans polyacetylene. The HF theory predicts insulating CDW ground states for both systems in their equidistant structures at low temperatures. In the same structures, they turn metallic at high temperatures. Starting from the “dimerized” low-temperature equilibrium structures, the systems need even higher temperatures to undergo a Peierls transition, which is accompanied by geometric as well as electronic distortions from dimerized to non-dimerized forms. The conventional finite-temperature MP2 theory shows a sign of divergence in any phase at any nonzero temperature and is useless. The renormalized finite-temperature MP2 (MP2R) theory is divergent only near metallic electronic structures, but is well behaved elsewhere. MP2R also predicts CDW and Peierls transitions occurring at two different temperatures. The effect of electron correlation is primarily to lower the Peierls transition temperature

  20. Basic physics of one-dimensional metals

    Emery, V.J.

    1976-01-01

    Largely nonmathematical qualitative lectures are given on the basic physics of nearly one-dimensional conductors. The main emphasis is placed on the properties of a purely one-dimensional electron gas. The effects of a real system having interchain coupling, impurities, a compressible lattice, lattice distortions and phonon anomalies are discussed

  1. Graphene-based one-dimensional photonic crystal

    Berman, Oleg L.; Kezerashvili, Roman Ya.

    2011-01-01

    A novel type of one-dimensional (1D) photonic crystal formed by the array of periodically located stacks of alternating graphene and dielectric stripes embedded into a background dielectric medium is proposed. The wave equation for the electromagnetic wave propagating in such structure solved in the framework of the Kronig-Penney model. The frequency band structure of 1D graphene-based photonic crystal is obtained analytically as a function of the filling factor and the thickness of the diele...

  2. One-dimensional crystal with a complex periodic potential

    Boyd, John K.

    2001-01-01

    A one-dimensional crystal model is constructed with a complex periodic potential. A wave function solution for the crystal model is derived without relying on Bloch functions. The new wave function solution of this model is shown to correspond to the solution for the probability amplitude of a two-level system. The energy discriminant is evaluated using an analytic formula derived from the probability amplitude solution, and based on an expansion parameter related to the energy and potential amplitude. From the wave function energy discriminant the crystal band structure is derived and related to standard energy bands and gaps. It is also shown that several of the properties of the two-level system apply to the one-dimensional crystal model. The two-level system solution which evolves in time is shown to manifest as a spatial configuration of the one-dimensional crystal model. The sensitivity of the wave function probability density is interpreted in the context of the new solution. The spatial configuration of the wave function, and the appearance of a long wavelength in the wave function probability density is explained in terms of the properties of Bessel functions

  3. Full-wave current conveyor precision rectifier

    Đukić Slobodan R.

    2008-01-01

    Full Text Available A circuit that provides precision rectification of small signal with low temperature sensitivity for frequencies up to 100 kHz without waveform distortion is presented. It utilizes an improved second type current conveyor based on current-steering output stage and biased silicon diodes. The use of a DC current source to bias the rectifying diodes provides higher temperature stability and lower DC offset level at the output. Proposed design of the precision rectifier ensures good current transfer linearity in the range that satisfy class A of the amplifier and good voltage transfer characteristic for low level signals. Distortion during the zero crossing of the input signal is practically eliminated. Design of the proposed rectifier is realized with standard components.

  4. One-Dimensional Czedli-Type Islands

    Horvath, Eszter K.; Mader, Attila; Tepavcevic, Andreja

    2011-01-01

    The notion of an island has surfaced in recent algebra and coding theory research. Discrete versions provide interesting combinatorial problems. This paper presents the one-dimensional case with finitely many heights, a topic convenient for student research.

  5. Analytical solution of one dimensional temporally dependent ...

    user

    transfer of heat in fluids, flow through porous media, and the spread of ... In present paper, advection-dispersion equation is considered one dimensional longitudinal initially solute free semi- .... free. Thus initial and boundary conditions for eq.

  6. Source inversion in the full-wave tomography; Full wave tomography ni okeru source inversion

    Tsuchiya, T [DIA Consultants Co. Ltd., Tokyo (Japan)

    1997-10-22

    In order to consider effects of characteristics of a vibration source in the full-wave tomography (FWT), a study has been performed on a method to invert vibration source parameters together with V(p)/V(s) distribution. The study has expanded an analysis method which uses as the basic the gradient method invented by Tarantola and the partial space method invented by Sambridge, and conducted numerical experiments. The experiment No. 1 has performed inversion of only the vibration source parameters, and the experiment No. 2 has executed simultaneous inversion of the V(p)/V(s) distribution and the vibration source parameters. The result of the discussions revealed that and effective analytical procedure would be as follows: in order to predict maximum stress, the average vibration source parameters and the property parameters are first inverted simultaneously; in order to estimate each vibration source parameter at a high accuracy, the property parameters are fixed, and each vibration source parameter is inverted individually; and the derived vibration source parameters are fixed, and the property parameters are again inverted from the initial values. 5 figs., 2 tabs.

  7. Factorizations of one-dimensional classical systems

    Kuru, Senguel; Negro, Javier

    2008-01-01

    A class of one-dimensional classical systems is characterized from an algebraic point of view. The Hamiltonians of these systems are factorized in terms of two functions that together with the Hamiltonian itself close a Poisson algebra. These two functions lead directly to two time-dependent integrals of motion from which the phase motions are derived algebraically. The systems so obtained constitute the classical analogues of the well known factorizable one-dimensional quantum mechanical systems

  8. One-dimensional photonic crystal design

    Mee, Cornelis van der; Contu, Pietro; Pintus, Paolo

    2010-01-01

    In this article we present a method to determine the band spectrum, band gaps, and discrete energy levels, of a one-dimensional photonic crystal with localized impurities. For one-dimensional crystals with piecewise constant refractive indices we develop an algorithm to recover the refractive index distribution from the period map. Finally, we derive the relationship between the period map and the scattering matrix containing the information on the localized modes.

  9. The essential theory of fast wave current drive with full wave method

    Liu Yan; Gong Xueyu; Yang Lei; Yin Chenyan; Yin Lan

    2007-01-01

    The full wave numerical method is developed for analyzing fast wave current drive in the range of ion cyclotron waves in tokamak plasmas, taking into account finite larmor radius effects and parallel dispersion. the physical model, the dispersion relation on the assumption of Finite Larmor Radius (FLR) effects and the form of full wave be used for computer simulation are developed. All of the work will contribute to further study of fast wave current drive. (authors)

  10. MARCUSE’S ONE-DIMENSIONAL SOCIETY IN ONE-DIMENSIONAL MAN

    MILOS RASTOVIC

    2013-05-01

    Full Text Available Nowadays, Marcuse’s main book One-Dimensional Man is almost obsolete, or rather passé. However, there are reasons to renew the reading of his book because of “the crisis of capitalism,” and the prevailing framework of technological domination in “advanced industrial society” in which we live today. “The new forms of control” in “advanced industrial societies” have replaced traditional methods of political and economic administration. The dominant structural element of “advanced industrial society” has become a technical and scientific apparatus of production and distribution of technology and administrative practice based on application of impersonal rules by a hierarchy of associating authorities. Technology has been liberated from the control of particular interests, and it has become the factor of domination in itself. Technological domination stems from the technical development of the productive apparatus that reproduces its ability into all spheres of social life (cultural, political, and economic. Based upon this consideration, in this paper, I will examine Marcuse’s ideas of “the new forms of control,” which creates a one–dimensional society. Marcuse’s fundamental thesis in One-Dimensional Man is that technological rationality is the most dominant factor in an “advanced industrial society,” which unites two earlier opposing forces of dissent: the bourgeoisie and the proletariat.

  11. 2D full wave simulation on electromagnetic wave propagation in toroidal plasma

    Hojo, Hitoshi; Uruta, Go; Nakayama, Kazunori; Mase, Atsushi

    2002-01-01

    Global full-wave simulation on electromagnetic wave propagation in toroidal plasma with an external magnetic field imaging a tokamak configuration is performed in two dimensions. The temporal behavior of an electromagnetic wave launched into plasma from a wave-guiding region is obtained. (author)

  12. One-dimensional Gromov minimal filling problem

    Ivanov, Alexandr O; Tuzhilin, Alexey A

    2012-01-01

    The paper is devoted to a new branch in the theory of one-dimensional variational problems with branching extremals, the investigation of one-dimensional minimal fillings introduced by the authors. On the one hand, this problem is a one-dimensional version of a generalization of Gromov's minimal fillings problem to the case of stratified manifolds. On the other hand, this problem is interesting in itself and also can be considered as a generalization of another classical problem, the Steiner problem on the construction of a shortest network connecting a given set of terminals. Besides the statement of the problem, we discuss several properties of the minimal fillings and state several conjectures. Bibliography: 38 titles.

  13. Scattering theory for one-dimensional step potentials

    Ruijsenaars, S.N.M.; Bongaarts, P.J.M.

    1977-01-01

    The scattering theory is treated for the one-dimensional Dirac equation with potentials that are bounded, measurable, real-valued functions on the real line, having constant values, not necessarily the same, on the left and on the right side of a compact interval. Such potentials appear in the Klein paradox. It is shown that appropriately modified wave operators exist and that the corresponding S-operator is unitary. The connection between time-dependent scattering theory and time-independent scattering theory in terms of incoming and outgoing plane wave solutions is established and some further properties are proved. All results and their proofs have a straightforward translation to the one-dimensional Schroedinger equation with the same class of step potentials

  14. Design and Control of Full Scale Wave Energy Simulator System

    Pedersen, Henrik C.; Hansen, Anders Hedegaard; Hansen, Rico Hjerm

    2012-01-01

    For wave energy to become feasible it is a requirement that the efficiency and reliability of the power take-off (PTO) systems are significantly improved. The cost of installing and testing PTO-systems at sea are however very high, and the focus of the current paper is therefore on the design...... of a full scale wave simulator for testing PTO-systems for point absorbers. The main challenge is here to design a system, which mimics the behavior of a wave when interacting with a given PTO-system. The paper includes a description of the developed system, located at Aalborg University......, and the considerations behind the design. Based on the description a model of the system is presented, which, along with a description of the wave theory applied, makes the foundation for the control strategy. The objective of the control strategy is to emulate not only the wave behavior, but also the dynamic wave...

  15. Detection of sinkholes or anomalies using full seismic wave fields.

    2013-04-01

    This research presents an application of two-dimensional (2-D) time-domain waveform tomography for detection of embedded sinkholes and anomalies. The measured seismic surface wave fields were inverted using a full waveform inversion (FWI) technique, ...

  16. Sounds in one-dimensional superfluid helium

    Um, C.I.; Kahng, W.H.; Whang, E.H.; Hong, S.K.; Oh, H.G.; George, T.F.

    1989-01-01

    The temperature variations of first-, second-, and third-sound velocity and attenuation coefficients in one-dimensional superfluid helium are evaluated explicitly for very low temperatures and frequencies (ω/sub s/tau 2 , and the ratio of second sound to first sound becomes unity as the temperature decreases to absolute zero

  17. Highly conducting one-dimensional solids

    Evrard, Roger; Doren, Victor

    1979-01-01

    Although the problem of a metal in one dimension has long been known to solid-state physicists, it was not until the synthesis of real one-dimensional or quasi-one-dimensional systems that this subject began to attract considerable attention. This has been due in part to the search for high­ temperature superconductivity and the possibility of reaching this goal with quasi-one-dimensional substances. A period of intense activity began in 1973 with the report of a measurement of an apparently divergent conduc­ tivity peak in TfF-TCNQ. Since then a great deal has been learned about quasi-one-dimensional conductors. The emphasis now has shifted from trying to find materials of very high conductivity to the many interesting problems of physics and chemistry involved. But many questions remain open and are still under active investigation. This book gives a review of the experimental as well as theoretical progress made in this field over the last years. All the chapters have been written by scientists who have ...

  18. Controlled size and one-dimensional growth

    875–881. c Indian Academy of Sciences. Synthesis of azamacrocycle stabilized palladium nanoparticles: Controlled size and one-dimensional growth. JEYARAMAN ATHILAKSHMI and DILLIP KUMAR CHAND. ∗. Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India e-mail: dillip@iitm.ac.

  19. A review on one dimensional perovskite nanocrystals for piezoelectric applications

    Li-Qian Cheng

    2016-03-01

    Full Text Available In recent years, one-dimensional piezoelectric nanomaterials have become a research topic of interest because of their special morphology and excellent piezoelectric properties. This article presents a short review on one dimensional perovskite piezoelectric materials in different systems including Pb(Zr,TiO3, BaTiO3 and (K,NaNbO3 (KNN. We emphasize KNN as a promising lead-free piezoelectric compound with a high Curie temperature and high piezoelectric properties and describe its synthesis and characterization. In particular, details are presented for nanoscale piezoelectricity characterization of a single KNN nanocrystal by piezoresponse force microscopy. Finally, this review describes recent progress in applications based on one dimensional piezoelectric nanostructures with a focus on energy harvesting composite materials.

  20. Realization of Configurable One-Dimensional Reflectarray

    2017-08-31

    experiments show strong signatures of beam steering that are dependent upon graphene doping. This seed grant has allowed our team to establish the essential...based, one-dimensional reflectarrays. Several immediate improvements to the device design and process flow are essential to suppress specular...beam steering that are dependent upon graphene doping. This seed grant has allowed our team to establish the essential operating procedures (i.e

  1. Computational study on full-wave inversion based on the elastic wave-equation; Dansei hado hoteishiki full wave inversion no model keisan ni yoru kento

    Uesaka, S [Kyoto University, Kyoto (Japan). Faculty of Engineering; Watanabe, T; Sassa, K [Kyoto University, Kyoto (Japan)

    1997-05-27

    Algorithm is constructed and a program developed for a full-wave inversion (FWI) method utilizing the elastic wave equation in seismic exploration. The FWI method is a method for obtaining a physical property distribution using the whole observed waveforms as the data. It is capable of high resolution which is several times smaller than the wavelength since it can handle such phenomena as wave reflection and dispersion. The method for determining the P-wave velocity structure by use of the acoustic wave equation does not provide information about the S-wave velocity since it does not consider S-waves or converted waves. In an analysis using the elastic wave equation, on the other hand, not only P-wave data but also S-wave data can be utilized. In this report, under such circumstances, an inverse analysis algorithm is constructed on the basis of the elastic wave equation, and a basic program is developed. On the basis of the methods of Mora and of Luo and Schuster, the correction factors for P-wave and S-wave velocities are formulated directly from the elastic wave equation. Computations are performed and the effects of the hypocenter frequency and vibration transmission direction are examined. 6 refs., 8 figs.

  2. Solitons in one-dimensional antiferromagnetic chains

    Pires, A.S.T.; Talim, S.L.; Costa, B.V.

    1989-01-01

    We study the quantum-statistical mechanics, at low temperatures, of a one-dimensional antiferromagnetic Heisenberg model with two anisotropies. In the weak-coupling limit we determine the temperature dependences of the soliton energy and the soliton density. We have found that the leading correction to the sine-Gordon (SG) expression for the soliton density and the quantum soliton energy comes from the out-of-plane magnon mode, not present in the pure SG model. We also show that when an external magnetic field is applied, the chain supports a new type of kink, where the sublattices rotate in opposite directions

  3. Underwater striling engine design with modified one-dimensional model

    Daijin Li

    2015-05-01

    Full Text Available Stirling engines are regarded as an efficient and promising power system for underwater devices. Currently, many researches on one-dimensional model is used to evaluate thermodynamic performance of Stirling engine, but in which there are still some aspects which cannot be modeled with proper mathematical models such as mechanical loss or auxiliary power. In this paper, a four-cylinder double-acting Stirling engine for Unmanned Underwater Vehicles (UUVs is discussed. And a one-dimensional model incorporated with empirical equations of mechanical loss and auxiliary power obtained from experiments is derived while referring to the Stirling engine computer model of National Aeronautics and Space Administration (NASA. The P-40 Stirling engine with sufficient testing results from NASA is utilized to validate the accuracy of this one-dimensional model. It shows that the maximum error of output power of theoretical analysis results is less than 18% over testing results, and the maximum error of input power is no more than 9%. Finally, a Stirling engine for UUVs is designed with Schmidt analysis method and the modified one-dimensional model, and the results indicate this designed engine is capable of showing desired output power.

  4. Rational solutions to two- and one-dimensional multicomponent Yajima–Oikawa systems

    Chen, Junchao; Chen, Yong; Feng, Bao-Feng; Maruno, Ken-ichi

    2015-01-01

    Exact explicit rational solutions of two- and one-dimensional multicomponent Yajima–Oikawa (YO) systems, which contain multi-short-wave components and single long-wave one, are presented by using the bilinear method. For two-dimensional system, the fundamental rational solution first describes the localized lumps, which have three different patterns: bright, intermediate and dark states. Then, rogue waves can be obtained under certain parameter conditions and their behaviors are also classified to above three patterns with different definition. It is shown that the simplest (fundamental) rogue waves are line localized waves which arise from the constant background with a line profile and then disappear into the constant background again. In particular, two-dimensional intermediate and dark counterparts of rogue wave are found with the different parameter requirements. We demonstrate that multirogue waves describe the interaction of several fundamental rogue waves, in which interesting curvy wave patterns appear in the intermediate times. Different curvy wave patterns form in the interaction of different types fundamental rogue waves. Higher-order rogue waves exhibit the dynamic behaviors that the wave structures start from lump and then retreat back to it, and this transient wave possesses the patterns such as parabolas. Furthermore, different states of higher-order rogue wave result in completely distinguishing lumps and parabolas. Moreover, one-dimensional rogue wave solutions with three states are constructed through the further reduction. Specifically, higher-order rogue wave in one-dimensional case is derived under the parameter constraints. - Highlights: • Exact explicit rational solutions of two-and one-dimensional multicomponent Yajima–Oikawa systems. • Two-dimensional rogue wave contains three different patterns: bright, intermediate and dark states. • Multi- and higher-order rogue waves exhibit distinct dynamic behaviors in two-dimensional case

  5. One-dimensional plasma photonic crystals with sinusoidal densities

    Qi, L.; Shang, L.; Zhang, S.

    2014-01-01

    Properties of electromagnetic waves with normal and oblique incidence have been studied for one-dimensional plasma layers with sinusoidal densities. Wave transmittance as a function of wave frequency exhibits photonic band gaps characteristic of photonic crystals. For periodic structures, increasing collision frequency is demonstrated to lead to greater absorption, increasing the modulation factor enlarges the gap width, and increasing incidence angle can change the gap locations of the two polarizations. If a defect layer is introduced by inserting a new plasma layer in the center, a defect mode may appear within the gap. Periodic number, collision frequency, and modulation factor can affect magnitude of the defect mode. The incidence angle enables the frequency to be tuned. Defect layer thickness affects both frequency and number of defect modes. These results may provide theoretical guidance in designing tunable narrow-band filters

  6. Quasi-one-dimensional metals on semiconductor surfaces with defects

    Hasegawa, Shuji

    2010-01-01

    Several examples are known in which massive arrays of metal atomic chains are formed on semiconductor surfaces that show quasi-one-dimensional metallic electronic structures. In this review, Au chains on Si(557) and Si(553) surfaces, and In chains on Si(111) surfaces, are introduced and discussed with regard to the physical properties determined by experimental data from scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES) and electrical conductivity measurements. They show quasi-one-dimensional Fermi surfaces and parabolic band dispersion along the chains. All of them are known from STM and ARPES to exhibit metal-insulator transitions by cooling and charge-density-wave formation due to Peierls instability of the metallic chains. The electrical conductivity, however, reveals the metal-insulator transition only on the less-defective surfaces (Si(553)-Au and Si(111)-In), but not on a more-defective surface (Si(557)-Au). The latter shows an insulating character over the whole temperature range. Compared with the electronic structure (Fermi surfaces and band dispersions), the transport property is more sensitive to the defects. With an increase in defect density, the conductivity only along the metal atomic chains was significantly reduced, showing that atomic-scale point defects decisively interrupt the electrical transport along the atomic chains and hide the intrinsic property of transport in quasi-one-dimensional systems.

  7. Interference electron microscopy of one-dimensional electron-optical phase objects

    Fazzini, P.F.; Ortolani, L.; Pozzi, G.; Ubaldi, F.

    2006-01-01

    The application of interference electron microscopy to the investigation of electron optical one-dimensional phase objects like reverse biased p-n junctions and ferromagnetic domain walls is considered. In particular the influence of diffraction from the biprism edges on the interference images is analyzed and the range of applicability of the geometric optical equation for the interpretation of the interference fringe shifts assessed by comparing geometric optical images with full wave-optical simulations. Finally, the inclusion of partial spatial coherence effects are discussed

  8. One-dimensional energy flow model for poroelastic material

    Kim, Jung Soo; Kang, Yeon June

    2009-01-01

    This paper presents a one-dimensional energy flow model to investigate the energy behavior for poroelastic media coupled with acoustical media. The proposed energy flow model is expressed by an independent energy governing equation that is classified into each wave component propagating in poroelastic media. The energy governing equation is derived using the General Energetic Method (GEM). To facilitate a comparison with the classical solution based on the conventional displacement-base formulation, approximate solutions of energy density and intensity are obtained. Furthermore, the limitations and usability of the proposed energy flow model for poroelastic media are described.

  9. Realistic full wave modeling of focal plane array pixels.

    Campione, Salvatore [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Warne, Larry K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Jorgenson, Roy E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Davids, Paul [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.; Peters, David W. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.

    2017-11-01

    Here, we investigate full-wave simulations of realistic implementations of multifunctional nanoantenna enabled detectors (NEDs). We focus on a 2x2 pixelated array structure that supports two wavelengths of operation. We design each resonating structure independently using full-wave simulations with periodic boundary conditions mimicking the whole infinite array. We then construct a supercell made of a 2x2 pixelated array with periodic boundary conditions mimicking the full NED; in this case, however, each pixel comprises 10-20 antennas per side. In this way, the cross-talk between contiguous pixels is accounted for in our simulations. We observe that, even though there are finite extent effects, the pixels work as designed, each responding at the respective wavelength of operation. This allows us to stress that realistic simulations of multifunctional NEDs need to be performed to verify the design functionality by taking into account finite extent and cross-talk effects.

  10. 2D full-wave simulation of waves in space and tokamak plasmas

    Kim Eun-Hwa

    2017-01-01

    Full Text Available Simulation results using a 2D full-wave code (FW2D for space and NSTX fusion plasmas are presented. The FW2D code solves the cold plasma wave equations using the finite element method. The wave code has been successfully applied to describe low frequency waves in planetary magnetospheres (i.e., dipole geometry and the results include generation and propagation of externally driven ultra-low frequency waves via mode conversion at Mercury and mode coupling, refraction and reflection of internally driven field-aligned propagating left-handed electromagnetic ion cyclotron (EMIC waves at Earth. In this paper, global structure of linearly polarized EMIC waves is examined and the result shows such resonant wave modes can be localized near the equatorial plane. We also adopt the FW2D code to tokamak geometry and examine radio frequency (RF waves in the scape-off layer (SOL of tokamaks. By adopting the rectangular and limiter boundary, we compare the results with existing AORSA simulations. The FW2D code results for the high harmonic fast wave heating case on NSTX with a rectangular vessel boundary shows excellent agreement with the AORSA code.

  11. One-dimensional nanomaterials for energy storage

    Chen, Cheng; Fan, Yuqi; Gu, Jianhang; Wu, Liming; Passerini, Stefano; Mai, Liqiang

    2018-03-01

    The search for higher energy density, safer, and longer cycling-life energy storage systems is progressing quickly. One-dimensional (1D) nanomaterials have a large length-to-diameter ratio, resulting in their unique electrical, mechanical, magnetic and chemical properties, and have wide applications as electrode materials in different systems. This article reviews the latest hot topics in applying 1D nanomaterials, covering both their synthesis and their applications. 1D nanomaterials can be grouped into the categories: carbon, silicon, metal oxides, and conducting polymers, and we structure our discussion accordingly. Then, we survey the unique properties and application of 1D nanomaterials in batteries and supercapacitors, and provide comments on the progress and advantages of those systems, paving the way for a better understanding of employing 1D nanomaterials for energy storage.

  12. One-Dimensional Modelling of Internal Ballistics

    Monreal-González, G.; Otón-Martínez, R. A.; Velasco, F. J. S.; García-Cascáles, J. R.; Ramírez-Fernández, F. J.

    2017-10-01

    A one-dimensional model is introduced in this paper for problems of internal ballistics involving solid propellant combustion. First, the work presents the physical approach and equations adopted. Closure relationships accounting for the physical phenomena taking place during combustion (interfacial friction, interfacial heat transfer, combustion) are deeply discussed. Secondly, the numerical method proposed is presented. Finally, numerical results provided by this code (UXGun) are compared with results of experimental tests and with the outcome from a well-known zero-dimensional code. The model provides successful results in firing tests of artillery guns, predicting with good accuracy the maximum pressure in the chamber and muzzle velocity what highlights its capabilities as prediction/design tool for internal ballistics.

  13. Stability model for one-dimensional FRCs

    Schwarzmeier, J.L.; Hewitt, T.G.; Lewis, H.R.; Seyler, C.E.; Symon, K.R.

    1982-01-01

    The subject of transport near the separatrix in FRC devices is important for determining the performance to be expected from an FRC reactor or from FRC experiments. A computer code was constructed for studying the micro-stability properties of FRCs near the separatrix as a first step in obtaining quasilinear transport coefficients that can be used in a transport code. We consider collisionless ions and electrons, without an expansion in powers of a parameter, like the electron or ion gyroradius, and we approximate the equilibrium with an infinitely long axially and translationally symmetric equilibrium. Thus, in our equilibria, there are only an axial magnetic field and a radial electric field. Our equilibria are collisionless, two-species, diffuse-profile, one-dimensional, theta-pinch equilibria. We allow the possibility that there be a magnetic field null in order to be able to model FRC devices more realistically

  14. One-Dimensional Photonic Crystal Superprisms

    Ting, David

    2005-01-01

    Theoretical calculations indicate that it should be possible for one-dimensional (1D) photonic crystals (see figure) to exhibit giant dispersions known as the superprism effect. Previously, three-dimensional (3D) photonic crystal superprisms have demonstrated strong wavelength dispersion - about 500 times that of conventional prisms and diffraction gratings. Unlike diffraction gratings, superprisms do not exhibit zero-order transmission or higher-order diffraction, thereby eliminating cross-talk problems. However, the fabrication of these 3D photonic crystals requires complex electron-beam substrate patterning and multilayer thin-film sputtering processes. The proposed 1D superprism is much simpler in structural complexity and, therefore, easier to design and fabricate. Like their 3D counterparts, the 1D superprisms can exhibit giant dispersions over small spectral bands that can be tailored by judicious structure design and tuned by varying incident beam direction. Potential applications include miniature gas-sensing devices.

  15. One dimensional systems with singular perturbations

    Alvarez, J J; Gadella, M; Nieto, L M; Glasser, L M; Lara, L P

    2011-01-01

    This paper discusses some one dimensional quantum models with singular perturbations. Eventually, a mass discontinuity is added at the points that support the singular perturbations. The simplest model includes an attractive singular potential with a mass jump both located at the origin. We study the form of the only bound state. Another model exhibits a hard core at the origin plus one or more repulsive deltas with mass jumps at the points supporting these deltas. We study the location and the multiplicity of these resonances for the case of one or two deltas and settle the basis for a generalization. Finally, we consider the harmonic oscillator and the infinite square well plus a singular potential at the origin. We see how the energy of bound states is affected by the singular perturbation.

  16. Cohesive motion in one-dimensional flocking

    Dossetti, V

    2012-01-01

    A one-dimensional rule-based model for flocking, which combines velocity alignment and long-range centering interactions, is presented and studied. The induced cohesion in the collective motion of the self-propelled agents leads to unique group behavior that contrasts with previous studies. Our results show that the largest cluster of particles, in the condensed states, develops a mean velocity slower than the preferred one in the absence of noise. For strong noise, the system also develops a non-vanishing mean velocity, alternating its direction of motion stochastically. This allows us to address the directional switching phenomenon. The effects of different sources of stochasticity on the system are also discussed. (paper)

  17. Benchmarking ICRF Full-wave Solvers for ITER

    Budny, R.V.; Berry, L.; Bilato, R.; Bonoli, P.; Brambilla, M.; Dumont, R.J.; Fukuyama, A.; Harvey, R.; Jaeger, E.F.; Indireshkumar, K.; Lerche, E.; McCune, D.; Phillips, C.K.; Vdovin, V.; Wright, J.

    2011-01-01

    Benchmarking of full-wave solvers for ICRF simulations is performed using plasma profiles and equilibria obtained from integrated self-consistent modeling predictions of four ITER plasmas. One is for a high performance baseline (5.3 T, 15 MA) DT H-mode. The others are for half-field, half-current plasmas of interest for the pre-activation phase with bulk plasma ion species being either hydrogen or He4. The predicted profiles are used by six full-wave solver groups to simulate the ICRF electromagnetic fields and heating, and by three of these groups to simulate the current-drive. Approximate agreement is achieved for the predicted heating power for the DT and He4 cases. Factor of two disagreements are found for the cases with second harmonic He3 heating in bulk H cases. Approximate agreement is achieved simulating the ICRF current drive.

  18. A quasi-one-dimensional theory of sound propagation in lined ducts with mean flow

    Dokumaci, Erkan

    2018-04-01

    Sound propagation in ducts with locally-reacting liners has received the attention of many authors proposing two- and three-dimensional solutions of the convected wave equation and of the Pridmore-Brown equation. One-dimensional lined duct models appear to have received less attention. The present paper proposes a quasi-one-dimensional theory for lined uniform ducts with parallel sheared mean flow. The basic assumption of the theory is that the effects of refraction and wall compliance on the fundamental mode remain within ranges in which the acoustic fluctuations are essentially uniform over a duct section. This restricts the model to subsonic low Mach numbers and Helmholtz numbers of less than about unity. The axial propagation constants and the wave transfer matrix of the duct are given by simple explicit expressions and can be applied with no-slip, full-slip or partial slip boundary conditions. The limitations of the theory are discussed and its predictions are compared with the fundamental mode solutions of the convected wave equation, the Pridmore-Brown equation and measurements where available.

  19. Design of full scale wave simulator for testing Power Take Off systems for wave energy converters

    Pedersen, H. C.; Hansen, R. H.; Hansen, Anders Hedegaard

    2016-01-01

    is therefore on the design and commissioning of a full scale wave simulator for testing PTO-systems for point absorbers. The challenge is to be able to design a system, which mimics the behavior of a wave when interacting with a given PTO-system – especially when considering discrete type PTO...

  20. On combined optical solitons of the one-dimensional Schrödinger’s equation with time dependent coefficients

    Kilic Bulent

    2016-01-01

    Full Text Available This paper integrates dispersive optical solitons in special optical metamaterials with a time dependent coefficient. We obtained some optical solitons of the aforementioned equation. It is shown that the examined dependent coefficients are affected by the velocity of the wave. The first integral method (FIM and ansatz method are applied to reach the optical soliton solutions of the one-dimensional nonlinear Schrödinger’s equation (NLSE with time dependent coefficients.

  1. Full-wave calculation of fast-wave current drive in tokamaks including kparallel upshifts

    Jaeger, E.F.; Batchelor, D.B.

    1991-01-01

    Numerical calculations of fast-wave current drive (FWCD) efficiency have generally been of two types: ray tracing or global wave calculations. Ray tracing shows that the projection of the wave number (k parallel) along the magnetic field can vary greatly over a ray trajectory, particularly when the launch point is above or below the equatorial plane. As the wave penetrates toward the center of the plasma, k parallel increases, causing a decrease in the parallel phase speed and a corresponding decrease in the current drive efficiency, γ. But the assumptions of geometrical optics, namely short wavelength and strong single-pass absorption, are not greatly applicable in FWCD scenarios. Eigenmode structure, which is ignored in ray tracing, can play an important role in determining electric field strength and Landau damping rates. In such cases, a full-wave or global solution for the wave fields is desirable. In full-wave calculations such as ORION k parallel appear as a differential operator (rvec B·∇) in the argument of the plasma dispersion function. Since this leads to a differential system of infinite order, such codes of necessity assume k parallel ∼ k var-phi = const, where k var-phi is the toroidal wave number. Thus, it is not possible to correctly include effects of the poloidal magnetic field on k parallel. The problem can be alleviated by expressing the electric field as a superposition of poloidal modes, in which case k parallel is purely algebraic. This paper describes a new full-wave calculation, Poloidal Ion Cyclotron Expansion Solution, which uses poloidal and toroidal mode expansions to solve the wave equation in general flux coordinates. The calculation includes a full solution for E parallel and uses a reduced-order form of the plasma conductivity tensor to eliminate numerical problems associated with resolution of the very short wavelength ion Bernstein wave

  2. 2D full-wave simulation of waves in space and tokamak plasmas

    Kim, Eun-Hwa; Bertelli, Nicola; Johnson, Jay; Valeo, Ernest; Hosea, Joel

    2017-10-01

    Simulation results using a 2D full-wave code (FW2D) for space and NSTX fusion plasmas are presented. The FW2D code solves the cold plasma wave equations using the finite element method. The wave code has been successfully applied to describe low frequency waves in planetary magnetospheres (i.e., dipole geometry) and the results include generation and propagation of externally driven ultra-low frequency waves via mode conversion at Mercury and mode coupling, refraction and reflection of internally driven field-aligned propagating left-handed electromagnetic ion cyclotron (EMIC) waves at Earth. In this paper, global structure of linearly polarized EMIC waves is examined and the result shows such resonant wave modes can be localized near the equatorial plane. We also adopt the FW2D code to tokamak geometry and examine radio frequency (RF) waves in the scape-off layer (SOL) of tokamaks. By adopting the rectangular and limiter boundary, we compare the results with existing AORSA simulations. The FW2D code results for the high harmonic fast wave heating case on NSTX with a rectangular vessel boundary shows excellent agreement with the AORSA code.

  3. Charge and spin separation in one-dimensional systems

    Balseiro, C.A.; Jagla, E.A.; Hallberg, K.

    1995-01-01

    In this article we discuss charge and spin separation and quantum interference in one-dimensional models. After a short introduction we briefly present the Hubbard and Luttinger models and discuss some of the known exact results. We study numerically the charge and spin separation in the Hubbard model. The time evolution of a wave packet is obtained and the charge and spin densities are evaluated for different times. The charge and spin wave packets propagate with different velocities. The results are interpreted in terms of the Bethe-ansatz solution. In section IV we study the effect of charge and spin separation on the quantum interference in a Aharonov-Bohm experiment. By calculating the one-particle propagators of the Luttinger model for a mesoscopic ring with a magnetic field we calculate the Aharonov-Bohm conductance. The conductance oscillates with the magnetic field with a characteristic frequency that depends on the charge and spin velocities. (author)

  4. Quasi-One-Dimensional Intermittent Flux Behavior in Superconducting Films

    A. J. Qviller

    2012-01-01

    Full Text Available Intermittent filamentary dynamics of the vortex matter in superconductors is found in films of YBa_{2}Cu_{3}O_{7-δ} deposited on tilted substrates. Deposition of this material on such substrates creates parallel channels of easy flux penetration when a magnetic field is applied perpendicular to the film. As the applied field is gradually increased, magneto-optical imaging reveals that flux penetrates via numerous quasi-one-dimensional jumps. The distribution of flux avalanche sizes follows a power law, and data collapse is obtained by finite-size scaling, with the depth of the flux front used as crossover length. The intermittent behavior shows no threshold value in the applied field, in contrast to conventional flux jumping. The results strongly suggest that the quasi-one-dimensional flux jumps are of a different nature than the thermomagnetic dendritic (branching avalanches that are commonly found in superconducting films.

  5. Resonance Raman spectroscopy in one-dimensional carbon materials

    Dresselhaus Mildred S.

    2006-01-01

    Full Text Available Brazil has played an important role in the development and use of resonance Raman spectroscopy as a powerful characterization tool for materials science. Here we present a short history of Raman scattering research in Brazil, highlighting the important contributions to the field coming from Brazilian researchers in the past. Next we discuss recent and important contributions where Brazil has become a worldwide leader, that is on the physics of quasi-one dimensional carbon nanotubes. We conclude this article by presenting results from a very recent resonance Raman study of exciting new materials, that are strictly one-dimensional carbon chains formed by the heat treatment of very pure double-wall carbon nanotube samples.

  6. Full-waveform inversion of surface waves in exploration geophysics

    Borisov, D.; Gao, F.; Williamson, P.; Tromp, J.

    2017-12-01

    Full-waveform inversion (FWI) is a data fitting approach to estimate high-resolution properties of the Earth from seismic data by minimizing the misfit between observed and calculated seismograms. In land seismics, the source on the ground generates high-amplitude surface waves, which generally represent most of the energy recorded by ground sensors. Although surface waves are widely used in global seismology and engineering studies, they are typically treated as noise within the seismic exploration community since they mask deeper reflections from the intervals of exploration interest. This is mainly due to the fact that surface waves decay exponentially with depth and for a typical frequency range (≈[5-50] Hz) sample only the very shallow part of the subsurface, but also because they are much more sensitive to S-wave than P-wave velocities. In this study, we invert surface waves in the hope of using them as additional information for updating the near surface. In a heterogeneous medium, the main challenge of surface wave inversion is associated with their dispersive character, which makes it difficult to define a starting model for conventional FWI which can avoid cycle-skipping. The standard approach to dealing with this is by inverting the dispersion curves in the Fourier (f-k) domain to generate locally 1-D models, typically for the shear wavespeeds only. However this requires that the near-surface zone be more or less horizontally invariant over a sufficient distance for the spatial Fourier transform to be applicable. In regions with significant topography, such as foothills, this is not the case, so we revert to the time-space domain, but aim to minimize the differences of envelopes in the early stages of the inversion to resolve the cycle-skipping issue. Once the model is good enough, we revert to the classic waveform-difference inversion. We first present a few synthetic examples. We show that classical FWI might be trapped in a local minimum even for

  7. Few quantum particles on one dimensional lattices

    Valiente Cifuentes, Manuel

    2010-01-01

    There is currently a great interest in the physics of degenerate quantum gases and low-energy few-body scattering due to the recent experimental advances in manipulation of ultracold atoms by light. In particular, almost perfect periodic potentials, called optical lattices, can be generated. The lattice spacing is fixed by the wavelength of the laser field employed and the angle betwen the pair of laser beams; the lattice depth, defining the magnitude of the different band gaps, is tunable within a large interval of values. This flexibility permits the exploration of different regimes, ranging from the ''free-electron'' picture, modified by the effective mass for shallow optical lattices, to the tight-binding regime of a very deep periodic potential. In the latter case, effective single-band theories, widely used in condensed matter physics, can be implemented with unprecedent accuracy. The tunability of the lattice depth is nowadays complemented by the use of magnetic Feshbach resonances which, at very low temperatures, can vary the relevant atom-atom scattering properties at will. Moreover, optical lattices loaded with gases of effectively reduced dimensionality are experimentally accessible. This is especially important for one spatial dimension, since most of the exactly solvable models in many-body quantum mechanics deal with particles on a line; therefore, experiments with one-dimensional gases serve as a testing ground for many old and new theories which were regarded as purely academic not so long ago. The physics of few quantum particles on a one-dimensional lattice is the topic of this thesis. Most of the results are obtained in the tight-binding approximation, which is amenable to exact numerical or analytical treatment. For the two-body problem, theoretical methods for calculating the stationary scattering and bound states are developed. These are used to obtain, in closed form, the two-particle solutions of both the Hubbard and extended Hubbard models

  8. Few quantum particles on one dimensional lattices

    Valiente Cifuentes, Manuel

    2010-06-18

    There is currently a great interest in the physics of degenerate quantum gases and low-energy few-body scattering due to the recent experimental advances in manipulation of ultracold atoms by light. In particular, almost perfect periodic potentials, called optical lattices, can be generated. The lattice spacing is fixed by the wavelength of the laser field employed and the angle betwen the pair of laser beams; the lattice depth, defining the magnitude of the different band gaps, is tunable within a large interval of values. This flexibility permits the exploration of different regimes, ranging from the ''free-electron'' picture, modified by the effective mass for shallow optical lattices, to the tight-binding regime of a very deep periodic potential. In the latter case, effective single-band theories, widely used in condensed matter physics, can be implemented with unprecedent accuracy. The tunability of the lattice depth is nowadays complemented by the use of magnetic Feshbach resonances which, at very low temperatures, can vary the relevant atom-atom scattering properties at will. Moreover, optical lattices loaded with gases of effectively reduced dimensionality are experimentally accessible. This is especially important for one spatial dimension, since most of the exactly solvable models in many-body quantum mechanics deal with particles on a line; therefore, experiments with one-dimensional gases serve as a testing ground for many old and new theories which were regarded as purely academic not so long ago. The physics of few quantum particles on a one-dimensional lattice is the topic of this thesis. Most of the results are obtained in the tight-binding approximation, which is amenable to exact numerical or analytical treatment. For the two-body problem, theoretical methods for calculating the stationary scattering and bound states are developed. These are used to obtain, in closed form, the two-particle solutions of both the Hubbard and

  9. Full wave simulations of fast wave mode conversion and lower hybrid wave propagation in tokamaks

    Wright, J.C.; Bonoli, P.T.; Brambilla, M.

    2004-01-01

    Fast wave (FW) studies of mode conversion (MC) processes at the ion-ion hybrid layer in toroidal plasmas must capture the disparate scales of the FW and mode converted ion Bernstein and ion cyclotron waves. Correct modeling of the MC layer requires resolving wavelengths on the order of k...

  10. One dimensional benchmark calculations using diffusion theory

    Ustun, G.; Turgut, M.H.

    1986-01-01

    This is a comparative study by using different one dimensional diffusion codes which are available at our Nuclear Engineering Department. Some modifications have been made in the used codes to fit the problems. One of the codes, DIFFUSE, solves the neutron diffusion equation in slab, cylindrical and spherical geometries by using 'Forward elimination- Backward substitution' technique. DIFFUSE code calculates criticality, critical dimensions and critical material concentrations and adjoint fluxes as well. It is used for the space and energy dependent neutron flux distribution. The whole scattering matrix can be used if desired. Normalisation of the relative flux distributions to the reactor power, plotting of the flux distributions and leakage terms for the other two dimensions have been added. Some modifications also have been made for the code output. Two Benchmark problems have been calculated with the modified version and the results are compared with BBD code which is available at our department and uses same techniques of calculation. Agreements are quite good in results such as k-eff and the flux distributions for the two cases studies. (author)

  11. One-dimensional model of inertial pumping

    Kornilovitch, Pavel E.; Govyadinov, Alexander N.; Markel, David P.; Torniainen, Erik D.

    2013-02-01

    A one-dimensional model of inertial pumping is introduced and solved. The pump is driven by a high-pressure vapor bubble generated by a microheater positioned asymmetrically in a microchannel. The bubble is approximated as a short-term impulse delivered to the two fluidic columns inside the channel. Fluid dynamics is described by a Newton-like equation with a variable mass, but without the mass derivative term. Because of smaller inertia, the short column refills the channel faster and accumulates a larger mechanical momentum. After bubble collapse the total fluid momentum is nonzero, resulting in a net flow. Two different versions of the model are analyzed in detail, analytically and numerically. In the symmetrical model, the pressure at the channel-reservoir connection plane is assumed constant, whereas in the asymmetrical model it is reduced by a Bernoulli term. For low and intermediate vapor bubble pressures, both models predict the existence of an optimal microheater location. The predicted net flow in the asymmetrical model is smaller by a factor of about 2. For unphysically large vapor pressures, the asymmetrical model predicts saturation of the effect, while in the symmetrical model net flow increases indefinitely. Pumping is reduced by nonzero viscosity, but to a different degree depending on the microheater location.

  12. Diffusiophoresis in one-dimensional solute gradients

    Ault, Jesse T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warren, Patrick B. [Unilever R& D Port Sunlight, Bebington (United Kingdom); Shin, Sangwoo [Univ. of Hawaii at Manoa, Honolulu, HI (United States); Stone, Howard A. [Princeton Univ., Princeton, NJ (United States)

    2017-11-06

    Here, the diffusiophoretic motion of suspended colloidal particles under one-dimensional solute gradients is solved using numerical and analytical techniques. Similarity solutions are developed for the injection and withdrawal dynamics of particles into semi-infinite pores. Furthermore, a method of characteristics formulation of the diffusion-free particle transport model is presented and integrated to realize particle trajectories. Analytical solutions are presented for the limit of small particle diffusiophoretic mobility Γp relative to the solute diffusivity Ds for particle motions in both semi-infinite and finite domains. Results confirm the build up of local maxima and minima in the propagating particle front dynamics. The method of characteristics is shown to successfully predict particle motions and the position of the particle front, although it fails to accurately predict suspended particle concentrations in the vicinity of sharp gradients, such as at the particle front peak seen in some injection cases, where particle diffusion inevitably plays an important role. Results inform the design of applications in which the use of applied solute gradients can greatly enhance particle injection into and withdrawal from pores.

  13. Diffusiophoresis in one-dimensional solute gradients

    Ault, Jesse T.; Warren, Patrick B.; Shin, Sangwoo; Stone, Howard A.

    2017-01-01

    Here, the diffusiophoretic motion of suspended colloidal particles under one-dimensional solute gradients is solved using numerical and analytical techniques. Similarity solutions are developed for the injection and withdrawal dynamics of particles into semi-infinite pores. Furthermore, a method of characteristics formulation of the diffusion-free particle transport model is presented and integrated to realize particle trajectories. Analytical solutions are presented for the limit of small particle diffusiophoretic mobility Γ p relative to the solute diffusivity D s for particle motions in both semi-infinite and finite domains. Results confirm the build up of local maxima and minima in the propagating particle front dynamics. The method of characteristics is shown to successfully predict particle motions and the position of the particle front, although it fails to accurately predict suspended particle concentrations in the vicinity of sharp gradients, such as at the particle front peak seen in some injection cases, where particle diffusion inevitably plays an important role. Results inform the design of applications in which the use of applied solute gradients can greatly enhance particle injection into and withdrawal from pores.

  14. Possibility designing half-wave and full-wave molecular rectifiers by using single benzene molecule

    Abbas, Mohammed A.; Hanoon, Falah H.; Al-Badry, Lafy F.

    2018-02-01

    This work focused on possibility designing half-wave and full-wave molecular rectifiers by using single and two benzene rings, respectively. The benzene rings were threaded by a magnetic flux that changes over time. The quantum interference effect was considered as the basic idea in the rectification action, the para and meta configurations were investigated. All the calculations are performed by using steady-state theoretical model, which is based on the time-dependent Hamiltonian model. The electrical conductance and the electric current are considered as DC output signals of half-wave and full-wave molecular rectifiers. The finding in this work opens up the exciting potential to use these molecular rectifiers in molecular electronics.

  15. A two-phase full-wave superconducting rectifier

    Ariga, T.; Ishiyama, A.

    1989-01-01

    A two-phase full-wave superconducting rectifier has been developed as a small cryogenic power supply of superconducting magnets for magnetically levitation trains. Those magnets are operated in the persistent current mode. However, small ohmic loss caused at resistive joints and ac loss induced by the vibration of the train cannot be avoided. Therefore, the low-power cryogenic power supply is required to compensate for the reduction in magnet current. The presented superconducting rectifier consists of two identical full-wave rectifiers connected in series. Main components of each rectifier are a troidal shape superconducting set-up transformer and two thermally controlled switches. The test results using a 47.5 mH load magnet at 0.2 Hz and 0.5 Hz operations are described. To estimate the characteristics of the superconducting rectifier, the authors have developed a simulation code. From the experiments and the simulations, the transfer efficiency is examined. Furthermore, the optimal design of thermally controlled switches based on the finite element analysis is also discussed

  16. One-Dimensional Forward–Forward Mean-Field Games

    Gomes, Diogo A., E-mail: diogo.gomes@kaust.edu.sa; Nurbekyan, Levon; Sedjro, Marc [King Abdullah University of Science and Technology (KAUST), CEMSE Division (Saudi Arabia)

    2016-12-15

    While the general theory for the terminal-initial value problem for mean-field games (MFGs) has achieved a substantial progress, the corresponding forward–forward problem is still poorly understood—even in the one-dimensional setting. Here, we consider one-dimensional forward–forward MFGs, study the existence of solutions and their long-time convergence. First, we discuss the relation between these models and systems of conservation laws. In particular, we identify new conserved quantities and study some qualitative properties of these systems. Next, we introduce a class of wave-like equations that are equivalent to forward–forward MFGs, and we derive a novel formulation as a system of conservation laws. For first-order logarithmic forward–forward MFG, we establish the existence of a global solution. Then, we consider a class of explicit solutions and show the existence of shocks. Finally, we examine parabolic forward–forward MFGs and establish the long-time convergence of the solutions.

  17. One-Dimensional Forward–Forward Mean-Field Games

    Gomes, Diogo A.; Nurbekyan, Levon; Sedjro, Marc

    2016-01-01

    While the general theory for the terminal-initial value problem for mean-field games (MFGs) has achieved a substantial progress, the corresponding forward–forward problem is still poorly understood—even in the one-dimensional setting. Here, we consider one-dimensional forward–forward MFGs, study the existence of solutions and their long-time convergence. First, we discuss the relation between these models and systems of conservation laws. In particular, we identify new conserved quantities and study some qualitative properties of these systems. Next, we introduce a class of wave-like equations that are equivalent to forward–forward MFGs, and we derive a novel formulation as a system of conservation laws. For first-order logarithmic forward–forward MFG, we establish the existence of a global solution. Then, we consider a class of explicit solutions and show the existence of shocks. Finally, we examine parabolic forward–forward MFGs and establish the long-time convergence of the solutions.

  18. One-Dimensional Forward–Forward Mean-Field Games

    Gomes, Diogo A.

    2016-11-01

    While the general theory for the terminal-initial value problem for mean-field games (MFGs) has achieved a substantial progress, the corresponding forward–forward problem is still poorly understood—even in the one-dimensional setting. Here, we consider one-dimensional forward–forward MFGs, study the existence of solutions and their long-time convergence. First, we discuss the relation between these models and systems of conservation laws. In particular, we identify new conserved quantities and study some qualitative properties of these systems. Next, we introduce a class of wave-like equations that are equivalent to forward–forward MFGs, and we derive a novel formulation as a system of conservation laws. For first-order logarithmic forward–forward MFG, we establish the existence of a global solution. Then, we consider a class of explicit solutions and show the existence of shocks. Finally, we examine parabolic forward–forward MFGs and establish the long-time convergence of the solutions.

  19. Whistler Observations on DEMETER Compared with Full Electromagnetic Wave Simulations

    Compston, A. J.; Cohen, M.; Lehtinen, N. G.; Inan, U.; Linscott, I.; Said, R.; Parrot, M.

    2014-12-01

    Terrestrial Very Low Frequency (VLF) electromagnetic radiation, which strongly impacts the Van Allen radiation belt electron dynamics, is injected across the ionosphere into the Earth's plasmasphere from two primary sources: man-made VLF transmitters and lightning discharges. Numerical models of trans-ionospheric propagation of such waves remain unvalidated, and early models may have overestimated the absorption, hindering a comprehensive understanding of the global impact of VLF waves in the loss of radiation belt electrons. In an attempt to remedy the problem of a lack of accurate trans-ionospheric propagation models, we have used a full electromagnetic wave method (FWM) numerical code to simulate the propagation of lightning-generated whistlers into the magnetosphere and compared the results with whistlers observed on the DEMETER satellite and paired with lightning stroke data from the National Lightning Detection Network (NLDN). We have identified over 20,000 whistlers occuring in 14 different passes of DEMETER over the central United States during the summer of 2009, and 14,000 of those occured within the 2000 km x 2000 km simulation grid we used. As shown in the attached figure, which shows a histogram of the ratio of the simulated whistler energy to the measured whistler energy for the 14,000 whistlers we compared, the simulation tends to slightly underestimate the total whistler energy injected by about 5 dB. However, the simulation underestimates the DEMETER measurements more as one gets further from the source lightning stroke, so since the signal to noise ratio of more distant whistlers will be smaller, possibly additive noise in the DEMETER measurements (which of course is not accounted for in the model) may explain some of the observed discrepancy.

  20. Computational study on full-wave inversion based on the acoustic wave-equation; Onkyoha hado hoteishiki full wave inversion no model keisan ni yoru kento

    Watanabe, T; Sassa, K [Kyoto University, Kyoto (Japan); Uesaka, S [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1996-10-01

    The effect of initial models on full-wave inversion (FWI) analysis based on acoustic wave-equation was studied for elastic wave tomography of underground structures. At present, travel time inversion using initial motion travel time is generally used, and inverse analysis is conducted using the concept `ray,` assuming very high wave frequency. Although this method can derive stable solutions relatively unaffected by initial model, it uses only the data of initial motion travel time. FWI calculates theoretical waveform at each receiver using all of observed waveforms as data by wave equation modeling where 2-D underground structure is calculated by difference calculus under the assumption that wave propagation is described by wave equation of P wave. Although it is a weak point that FWI is easily affected by noises in an initial model and data, it is featured by high resolution of solutions. This method offers very excellent convergence as a proper initial model is used, resulting in sufficient performance, however, it is strongly affected by initial model. 2 refs., 7 figs., 1 tab.

  1. Testing of a one dimensional model for Field II calibration

    Bæk, David; Jensen, Jørgen Arendt; Willatzen, Morten

    2008-01-01

    Field II is a program for simulating ultrasound transducer fields. It is capable of calculating the emitted and pulse-echoed fields for both pulsed and continuous wave transducers. To make it fully calibrated a model of the transducer’s electro-mechanical impulse response must be included. We...... examine an adapted one dimensional transducer model originally proposed by Willatzen [9] to calibrate Field II. This model is modified to calculate the required impulse responses needed by Field II for a calibrated field pressure and external circuit current calculation. The testing has been performed...... to the calibrated Field II program for 1, 4, and 10 cycle excitations. Two parameter sets were applied for modeling, one real valued Pz27 parameter set, manufacturer supplied, and one complex valued parameter set found in literature, Alguer´o et al. [11]. The latter implicitly accounts for attenuation. Results show...

  2. Lateral shifting in one dimensional chiral photonic crystal

    You Yuan; Chen Changyuan

    2012-01-01

    We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

  3. Magnons in one-dimensional k-component Fibonacci structures

    Costa, C. H., E-mail: carloshocosta@hotmail.com [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Vasconcelos, M. S. [Escola de Ciências e Tecnologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil)

    2014-05-07

    We have studied the magnon transmission through of one-dimensional magnonic k-component Fibonacci structures, where k different materials are arranged in accordance with the following substitution rule: S{sub n}{sup (k)}=S{sub n−1}{sup (k)}S{sub n−k}{sup (k)} (n≥k=0,1,2,…), where S{sub n}{sup (k)} is the nth stage of the sequence. The calculations were carried out in exchange dominated regime within the framework of the Heisenberg model and taking into account the RPA approximation. We have considered multilayers composed of simple cubic spin-S Heisenberg ferromagnets, and, by using the powerful transfer-matrix method, the spin wave transmission is obtained. It is demonstrated that the transmission coefficient has a rich and interesting magnonic pass- and stop-bands structures, which depends on the frequency of magnons and the k values.

  4. Lateral shifting in one dimensional chiral photonic crystal

    You Yuan, E-mail: yctcyouyuan@163.com [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China); Chen Changyuan [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China)

    2012-07-01

    We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

  5. Strongly-Refractive One-Dimensional Photonic Crystal Prisms

    Ting, David Z. (Inventor)

    2004-01-01

    One-dimensional (1D) photonic crystal prisms can separate a beam of polychromatic electromagnetic waves into constituent wavelength components and can utilize unconventional refraction properties for wavelength dispersion over significant portions of an entire photonic band rather than just near the band edges outside the photonic band gaps. Using a ID photonic crystal simplifies the design and fabrication process and allows the use of larger feature sizes. The prism geometry broadens the useful wavelength range, enables better optical transmission, and exhibits angular dependence on wavelength with reduced non-linearity. The properties of the 1 D photonic crystal prism can be tuned by varying design parameters such as incidence angle, exit surface angle, and layer widths. The ID photonic crystal prism can be fabricated in a planar process, and can be used as optical integrated circuit elements.

  6. ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES

    Nikola Stefanović

    2007-06-01

    Full Text Available In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic leadership style, leadership theory researchers use two dimensional matrices. The two-dimensional matrices define leadership styles on the basis of different parameters. By using these parameters, one can identify two-dimensional styles.

  7. Fragmented one dimensional man / El hombre unidimensional fragmentado

    Juan Antonio Rodríguez del Pino

    2013-10-01

    Full Text Available Paraphrase the title of the famous essay by Herbert Marcuse, since the image has traditionally been generated of man, masculinity, has been one-dimensional. I mean, the man was characterized by traits and behaviors established and entrenched since ancient time, considering all other distinguishing signs as mere deviations from the normative improper. But observe that this undeniable reality, as analyzed various researchers through what has come to be called Men's studies, has proven to be a fallacy difficult to maintain throughout history and today turns into fallacious and ineffective against changes in our current existing corporate models.

  8. One-dimensional rigid film acoustic metamaterials

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng

    2015-11-01

    We have designed a 1D film-type acoustic metamaterial structure consisting of several polymer films directly stacked on each other. It is experimentally revealed that the mass density law can be broken by such structures in the low frequency range. By comparing the sound transmission loss (STL) curves of structures with different numbers of cycles, materials and incident sound directions, several physical properties of the 1D film-type acoustic metamaterial are revealed, which consist of cyclical effects, surface effects and orientation effects. It is suggested that the excellent low frequency sound insulation capacity is influenced by both the cycle number and the stiffness of the film surface. Meanwhile, the surface effect plays a dominant role among these physical properties. Due to the surface acoustic property, for structures with a particular combination form, the STL dominated by the cyclical effects may reach saturation with increasing number of construction periods. Moreover, in some cases, the sound insulation ability is diverse for different sound incidence directions. This kind of 1D film-type periodic structure with these special physical properties provides a new concept for the regulation of sound waves.

  9. One-dimensional rigid film acoustic metamaterials

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng

    2015-01-01

    We have designed a 1D film-type acoustic metamaterial structure consisting of several polymer films directly stacked on each other. It is experimentally revealed that the mass density law can be broken by such structures in the low frequency range. By comparing the sound transmission loss (STL) curves of structures with different numbers of cycles, materials and incident sound directions, several physical properties of the 1D film-type acoustic metamaterial are revealed, which consist of cyclical effects, surface effects and orientation effects. It is suggested that the excellent low frequency sound insulation capacity is influenced by both the cycle number and the stiffness of the film surface. Meanwhile, the surface effect plays a dominant role among these physical properties. Due to the surface acoustic property, for structures with a particular combination form, the STL dominated by the cyclical effects may reach saturation with increasing number of construction periods. Moreover, in some cases, the sound insulation ability is diverse for different sound incidence directions. This kind of 1D film-type periodic structure with these special physical properties provides a new concept for the regulation of sound waves. (paper)

  10. Non-equilibrium dynamics of one-dimensional Bose gases

    Langen, T.

    2013-01-01

    Understanding the non-equilibrium dynamics of isolated quantum many-body systems is an open problem on vastly different energy, length, and time scales. Examples range from the dynamics of the early universe and heavy-ion collisions to the subtle coherence and transport properties in condensed matter physics. However, realizations of such quantum many-body systems, which are both well isolated from the environment and accessible to experimental study are scarce. This thesis presents a series of experiments with ultracold one-dimensional Bose gases. These gases combine a nearly perfect isolation from the environment with many well-established methods to manipulate and probe their quantum states. This makes them an ideal model system to explore the physics of quantum many body systems out of equilibrium. In the experiments, a well-defined non-equilibrium state is created by splitting a single one-dimensional gas coherently into two parts. The relaxation of this state is probed using matter-wave interferometry. The Observations reveal the emergence of a prethermalized steady state which differs strongly from thermal equilibrium. Such thermal-like states had previously been predicted for a large variety of systems, but never been observed directly. Studying the relaxation process in further detail shows that the thermal correlations of the prethermalized state emerge locally in their final form and propagate through the system in a light-cone-like evolution. This provides first experimental evidence for the local relaxation conjecture, which links relaxation processes in quantum many-body systems to the propagation of correlations. Furthermore, engineering the initial state of the evolution demonstrates that the prethermalized state is described by a generalized Gibbs ensemble, an observation which substantiates the importance of this ensemble as an extension of standard statistical mechanics. Finally, an experiment is presented, where pairs of gases with an atom

  11. Qualities of Wigner function and its applications to one-dimensional infinite potential and one-dimensional harmonic oscillator

    Xu Hao; Shi Tianjun

    2011-01-01

    In this article,the qualities of Wigner function and the corresponding stationary perturbation theory are introduced and applied to one-dimensional infinite potential well and one-dimensional harmonic oscillator, and then the particular Wigner function of one-dimensional infinite potential well is specified and a special constriction effect in its pure state Wigner function is discovered, to which,simultaneously, a detailed and reasonable explanation is elaborated from the perspective of uncertainty principle. Ultimately, the amendment of Wigner function and energy of one-dimensional infinite potential well and one-dimensional harmonic oscillator under perturbation are calculated according to stationary phase space perturbation theory. (authors)

  12. High-efficiency passive full wave rectification for electromagnetic harvesters

    Yilmaz, Mehmet; Tunkar, Bassam A.; Park, Sangtak; Elrayes, Karim; Mahmoud, Mohamed A. E.; Abdel-Rahman, Eihab; Yavuz, Mustafa

    2014-10-01

    We compare the performance of four types of full-wave bridge rectifiers designed for electromagnetic energy harvesters based on silicon diodes, Schottky diodes, passive MOSFETs, and active MOSFETs. Simulation and experimental results show that MOSFET-type rectifiers are more efficient than diode-type rectifiers, reaching voltage and power efficiency of 99% for ideal voltage source with input amplitudes larger than 800 mV. Since active MOSFETs require extra components and an external DC power supply, we conclude that passive MOSFETs are superior for micro-power energy harvesting systems. We demonstrate passive MOSFET rectifiers implemented using discrete, off-shelf components and show that they outperform all electromagnetic harvester rectifiers hitherto reported obtaining a power efficiency of 95%. Furthermore, we show that passive MOSFET rectifiers do not affect the center frequency, harvesting bandwidth, or optimal resistance of electromagnetic harvesters. We demonstrate a complete power management module by adding a capacitor to the rectifier output terminal. We found that this configuration changed the optimal resistive load from 40 Ω to 55 Ω and decreased output power efficiency to 86%.

  13. Electroconvection in one-dimensional liquid crystal cells

    Huh, Jong-Hoon

    2018-04-01

    We investigate the alternating current (ac) -driven electroconvection (EC) in one-dimensional cells (1DCs) under the in-plane switching mode. In 1DCs, defect-free EC can be realized. In the presence and absence of external multiplicative noise, the features of traveling waves (TWs), such as their Hopf frequency fH and velocity, are examined in comparison with those of conventional two-dimensional cells (2DCs) accompanying defects of EC rolls. In particular, we show that the defects significantly contribute to the features of the TWs. Additionally, owing to the defect-free EC in the 1DCs, the effects of the ac and noise fields on the TW are clarified. The ac field linearly increases fH, independent of the ac frequency f . The noise increases fH monotonically, but fH does not vary below a characteristic noise intensity VN*. In addition, soliton-like waves and unfamiliar oscillation of EC vortices in 1DCs are observed, in contrast to the localized EC (called worms) and the oscillation of EC rolls in 2DCs.

  14. Full wave simulation of waves in ECRIS plasmas based on the finite element method

    Torrisi, G. [INFN - Laboratori Nazionali del Sud, via S. Sofia 62, 95123, Catania, Italy and Università Mediterranea di Reggio Calabria, Dipartimento di Ingegneria dell' Informazione, delle Infrastrutture e dell' Energia Sostenibile (DIIES), Via Graziella, I (Italy); Mascali, D.; Neri, L.; Castro, G.; Patti, G.; Celona, L.; Gammino, S.; Ciavola, G. [INFN - Laboratori Nazionali del Sud, via S. Sofia 62, 95123, Catania (Italy); Di Donato, L. [Università degli Studi di Catania, Dipartimento di Ingegneria Elettrica Elettronica ed Informatica (DIEEI), Viale Andrea Doria 6, 95125 Catania (Italy); Sorbello, G. [INFN - Laboratori Nazionali del Sud, via S. Sofia 62, 95123, Catania, Italy and Università degli Studi di Catania, Dipartimento di Ingegneria Elettrica Elettronica ed Informatica (DIEEI), Viale Andrea Doria 6, 95125 Catania (Italy); Isernia, T. [Università Mediterranea di Reggio Calabria, Dipartimento di Ingegneria dell' Informazione, delle Infrastrutture e dell' Energia Sostenibile (DIIES), Via Graziella, I-89100 Reggio Calabria (Italy)

    2014-02-12

    This paper describes the modeling and the full wave numerical simulation of electromagnetic waves propagation and absorption in an anisotropic magnetized plasma filling the resonant cavity of an electron cyclotron resonance ion source (ECRIS). The model assumes inhomogeneous, dispersive and tensorial constitutive relations. Maxwell's equations are solved by the finite element method (FEM), using the COMSOL Multiphysics{sup ®} suite. All the relevant details have been considered in the model, including the non uniform external magnetostatic field used for plasma confinement, the local electron density profile resulting in the full-3D non uniform magnetized plasma complex dielectric tensor. The more accurate plasma simulations clearly show the importance of cavity effect on wave propagation and the effects of a resonant surface. These studies are the pillars for an improved ECRIS plasma modeling, that is mandatory to optimize the ion source output (beam intensity distribution and charge state, especially). Any new project concerning the advanced ECRIS design will take benefit by an adequate modeling of self-consistent wave absorption simulations.

  15. Full-wave modeling of ICRF waves: global and quasi-local descriptions

    Dumont, R. J.

    2007-01-01

    Waves in the Ion Cyclotron Range of Frequencies (ICRF) undergo significant space dispersion as they propagate in magnetic fusion plasmas, making it necessary to incorporate non-local effects in their physical description. Full-wave codes are routinely employed to simulate ICRF heating experiments in tokamaks. The vast majority of these codes rely on a description of the plasma based on a 'quasi-local' derivation of the dielectric tensor, i.e. assuming that the range of space dispersion remains small compared to the system dimensions. However, non-local effects caused by wide particle orbits are expected to play a significant role in current and future experiments featuring wave-driven fast ions, fusion-born alpha particles... Global formalisms have thus been proposed to include these effects in a more comprehensive fashion. Based on a description of the particle dynamics in terms of action-angle variables, a full-wave code, named EVE, is currently under development. Its first version, presented here, incorporates quasi-local expressions valid to second order in Larmor radius, derived from the more general Hamiltonian formalism. The obtained tool has the advantage of being compatible with the current requirements of integrated modeling, and lends itself to direct comparisons with existing codes

  16. Novel Method of Detecting Movement of the Interference Fringes Using One-Dimensional PSD

    Qi Wang

    2015-06-01

    Full Text Available In this paper, a method of using a one-dimensional position-sensitive detector (PSD by replacing charge-coupled device (CCD to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z interferometer is solved in theory, showing it has a higher resolution and sensitivity. According to the physical characteristics and principles of PSD, a simulation of the interference fringe’s phase difference in fiber M-Z interferometers and PSD output is carried out. Comparing the simulation results with the relationship between phase differences and centroid positions in fiber M-Z interferometers, the conclusion that the output of interference fringes by PSD is still the centroid position is obtained. Based on massive measurements, the best resolution of the system is achieved with 5.15, 625 μm. Finally, the detection system is evaluated through setup error analysis and an ultra-narrow-band filter structure. The filter structure is configured with a one-dimensional photonic crystal containing positive and negative refraction material, which can eliminate background light in the PSD detection experiment. This detection system has a simple structure, good stability, high precision and easily performs remote measurements, which makes it potentially useful in material small deformation tests, refractivity measurements of optical media and optical wave front detection.

  17. NMR relaxation rate in quasi one-dimensional antiferromagnets

    Capponi, Sylvain; Dupont, Maxime; Laflorencie, Nicolas; Sengupta, Pinaki; Shao, Hui; Sandvik, Anders W.

    We compare results of different numerical approaches to compute the NMR relaxation rate 1 /T1 in quasi one-dimensional (1d) antiferromagnets. In the purely 1d regime, recent numerical simulations using DMRG have provided the full crossover behavior from classical regime at high temperature to universal Tomonaga-Luttinger liquid at low-energy (in the gapless case) or activated behavior (in the gapped case). For quasi 1d models, we can use mean-field approaches to reduce the problem to a 1d one that can be studied using DMRG. But in some cases, we can also simulate the full microscopic model using quantum Monte-Carlo techniques. This allows to compute dynamical correlations in imaginary time and we will discuss recent advances to perform stochastic analytic continuation to get real frequency spectra. Finally, we connect our results to experiments on various quasi 1d materials.

  18. One-dimensional motion of a material with a strain theshold

    A. Farina

    2007-12-01

    Full Text Available We consider the one-dimensional shearing motion of a material exhibiting elastic behaviour when the stress is below some threshold. The threshold represents a limit to the deformability, i.e. no further deformation can occur on increasing the stress. The mathematical formulation leads to a free boundary problem for the wave equation, whose structure depends on whether the stress (and the velocity are continuous across the propagating interface for the strain threshold .Local existence and uniqueness are proved for the continuous case (in which the interface propagation is subsonic. Some explicit solutions are calculated for another case (with a supersonic interface. It is shown that the model with strain threshold is never the limit of hyperelastic systems.

  19. One-dimensional free-electron laser equations without the slowly varying envelope approximation

    C. Maroli

    2011-07-01

    Full Text Available A set of one-dimensional equations has been deduced in the time domain from the Maxwell-Lorentz system with the aim of describing the free-electron laser radiation without using the slowly varying envelope approximation (SVEA. These equations are valid even in the case of arbitrarily short electron bunches and of current distributions with ripples on the scale of or shorter than the wavelength. Numerical examples are presented, showing that for long homogeneous bunches the new set of equations gives results in agreement with the SVEA free-electron laser theory and that the use of short or prebunched electron beams leads to a decrease of the emission lethargy. Furthermore, we demonstrate that in all cases in which the backward low frequency wave has negligible effects, these equations can be reduced to a form similar to the usual 1D SVEA equations but with a different definition of the bunching term.

  20. Full-wave solution of short impulses in inhomogeneous plasma

    ... in arbitrarily inhomogeneous media will be presented on a fundamentally new, ... The general problem of wave propagation of monochromatic signals in inhomogeneous media was enlightened in [1]. ... Pramana – Journal of Physics | News.

  1. Modeling digital pulse waveforms by solving one-dimensional Navier-stokes equations.

    Fedotov, Aleksandr A; Akulova, Anna S; Akulov, Sergey A

    2016-08-01

    Mathematical modeling for composition distal arterial pulse wave in the blood vessels of the upper limbs was considered. Formation of distal arterial pulse wave is represented as a composition of forward and reflected pulse waves propagating along the arterial vessels. The formal analogy between pulse waves propagation along the human arterial system and the propagation of electrical oscillations in electrical transmission lines with distributed parameters was proposed. Dependencies of pulse wave propagation along the human arterial system were obtained by solving the one-dimensional Navier-Stokes equations for a few special cases.

  2. Dynamics of an impurity in a one-dimensional lattice

    Massel, F; Kantian, A; Giamarchi, T; Daley, A J; Törmä, P

    2013-01-01

    We study the non-equilibrium dynamics of an impurity in a harmonic trap that is kicked with a well-defined quasi-momentum, and interacts with a bath of free fermions or interacting bosons in a one-dimensional lattice configuration. Using numerical and analytical techniques we investigate the full dynamics beyond linear response, which allows us to quantitatively characterize states of the impurity in the bath for different parameter regimes. These vary from a tightly bound molecular state in a strongly interacting limit to a polaron (dressed impurity) and a free particle for weak interactions, with composite behaviour in the intermediate regime. These dynamics and different parameter regimes should be readily realizable in systems of cold atoms in optical lattices. (paper)

  3. Well-posedness of one-dimensional Korteweg models

    Sylvie Benzoni-Gavage

    2006-05-01

    Full Text Available We investigate the initial-value problem for one-dimensional compressible fluids endowed with internal capillarity. We focus on the isothermal inviscid case with variable capillarity. The resulting equations for the density and the velocity, consisting of the mass conservation law and the momentum conservation with Korteweg stress, are a system of third order nonlinear dispersive partial differential equations. Additionally, this system is Hamiltonian and admits travelling solutions, representing propagating phase boundaries with internal structure. By change of unknown, it roughly reduces to a quasilinear Schrodinger equation. This new formulation enables us to prove local well-posedness for smooth perturbations of travelling profiles and almost-global existence for small enough perturbations. A blow-up criterion is also derived.

  4. Modelling and Testing of Wave Dragon Wave Energy Converter Towards Full Scale Deployment

    Parmeggiani, Stefano

    -commercial stage in which it has proven difficult to secure the necessary funding for the deployment of a full-scale demonstrator unit. The work presented aims at easing this process, by increasing public and scientific knowledge of the device, as well as by showing the latest progress in its development. Research....... This is mainly due to the development of an updated overtopping model specifically suited to Wave Dragon, which allows greater quality to predictions of the primary energy absorption of the device compared to previous versions. At the same time an equitable approach has been described and used in the performance......, the research has also provided a deeper insight into the physics of the overtopping process by individually assessing the influence of related device configuration and wave features, which goes beyond the present application and may be used for other overtopping WECs as well. Comprehensive analysis...

  5. Validation and Comparison of One-Dimensional Ground Motion Methodologies

    B. Darragh; W. Silva; N. Gregor

    2006-01-01

    Both point- and finite-source stochastic one-dimensional ground motion models, coupled to vertically propagating equivalent-linear shear-wave site response models are validated using an extensive set of strong motion data as part of the Yucca Mountain Project. The validation and comparison exercises are presented entirely in terms of 5% damped pseudo absolute response spectra. The study consists of a quantitative analyses involving modeling nineteen well-recorded earthquakes, M 5.6 to 7.4 at over 600 sites. The sites range in distance from about 1 to about 200 km in the western US (460 km for central-eastern US). In general, this validation demonstrates that the stochastic point- and finite-source models produce accurate predictions of strong ground motions over the range of 0 to 100 km and for magnitudes M 5.0 to 7.4. The stochastic finite-source model appears to be broadband, producing near zero bias from about 0.3 Hz (low frequency limit of the analyses) to the high frequency limit of the data (100 and 25 Hz for response and Fourier amplitude spectra, respectively)

  6. Validation and Comparison of One-Dimensional Graound Motion Methodologies

    B. Darragh; W. Silva; N. Gregor

    2006-06-28

    Both point- and finite-source stochastic one-dimensional ground motion models, coupled to vertically propagating equivalent-linear shear-wave site response models are validated using an extensive set of strong motion data as part of the Yucca Mountain Project. The validation and comparison exercises are presented entirely in terms of 5% damped pseudo absolute response spectra. The study consists of a quantitative analyses involving modeling nineteen well-recorded earthquakes, M 5.6 to 7.4 at over 600 sites. The sites range in distance from about 1 to about 200 km in the western US (460 km for central-eastern US). In general, this validation demonstrates that the stochastic point- and finite-source models produce accurate predictions of strong ground motions over the range of 0 to 100 km and for magnitudes M 5.0 to 7.4. The stochastic finite-source model appears to be broadband, producing near zero bias from about 0.3 Hz (low frequency limit of the analyses) to the high frequency limit of the data (100 and 25 Hz for response and Fourier amplitude spectra, respectively).

  7. Study of one dimensional magnetic system via field theory

    Talim, S.L.

    1988-04-01

    We present a study of one-dimensional magnetic system using field theory methods. We studied the discreteness effects in a classical anisotropic one dimensional antiferromagnet in an external magnetic field. It is shown that for TMMC, at the temperatures and magnetic fields where most experiments have been done, the corrections are small and can be neglected. (author)

  8. Observation of Zero-Dimensional States in a One-Dimensional Electron Interferometer

    Wees, B.J. van; Kouwenhoven, L.P.; Harmans, C.J.P.M.; Williamson, J.G.; Timmering, C.E.; Broekaart, M.E.I.; Foxon, C.T.; Harris, J.J.

    1989-01-01

    We have studied the electron transport in a one-dimensional electron interferometer. It consists of a disk-shaped two-dimensional electron gas, to which quantum point contacts are attached. Discrete zero-dimensional states are formed due to constructive interference of electron waves traveling along

  9. Full-wave simulations of current profiles for fast magnetosonic wave current drive

    Dmitrieva, M.V.; Eriksson, L.-G.; Gambier, D.J.

    1992-12-01

    Numerical simulations of current drive in tokamaks by fast waves (FWCD) have been performed in the range of the ion cyclotron and at lower frequencies via 3-Dimensional numerical code ICTOR. Trapped particles effects were taken into account in the calculation of the fast wave current drive efficiency and the bootstrap current generation. The global efficiency of FWCD if found to be γ∼ 0.1 x 10 20 AW -1 m -2 for the Joint European Torus tokamak (JET) parameters at a central electron temperature of ∼ 10 kev. The efficiency of FWCD for reactor-like plasmas is found to be γ∼0.3 x 10 20 AW -1 m -2 for ∼ 100% of FWCD and γ∼ 1 x 10 20 AW -1 m -2 for FWCD and ∼ 65% of bootstrap in a total current of ∼ 25MA at a 25kev central temperature with a density of ∼10 20 m -3 and major radius R ∼ 8m. Non-inductive current density profiles are studied. Broad FWCD current profiles are obtained for flat reactor temperature and density profiles with bootstrap current concentrated at the plasma edge. The possibility of a steady-state reactor on full wave (FW) with a large fraction of bootstrap current is discussed. It appears to be impractical to rely on such an external current driven (CD) scheme for a reactor as long a γ is less than 2 x 10 20 AW -1 m -2 . (Author)

  10. AORSA full wave calculations of helicon waves in DIII-D and ITER

    Lau, C.; Jaeger, E. F.; Bertelli, N.; Berry, L. A.; Green, D. L.; Murakami, M.; Park, J. M.; Pinsker, R. I.; Prater, R.

    2018-06-01

    Helicon waves have been recently proposed as an off-axis current drive actuator for DIII-D, FNSF, and DEMO tokamaks. Previous ray tracing modeling using GENRAY predicts strong single pass absorption and current drive in the mid-radius region on DIII-D in high beta tokamak discharges. The full wave code AORSA, which is valid to all order of Larmor radius and can resolve arbitrary ion cyclotron harmonics, has been used to validate the ray tracing technique. If the scrape-off-layer (SOL) is ignored in the modeling, AORSA agrees with GENRAY in both the amplitude and location of driven current for DIII-D and ITER cases. These models also show that helicon current drive can possibly be an efficient current drive actuator for ITER. Previous GENRAY analysis did not include the SOL. AORSA has also been used to extend the simulations to include the SOL and to estimate possible power losses of helicon waves in the SOL. AORSA calculations show that another mode can propagate in the SOL and lead to significant (~10%–20%) SOL losses at high SOL densities. Optimizing the SOL density profile can reduce these SOL losses to a few percent.

  11. The fast algorithm solving the one-dimensional time-dependent Schroedinger equation for teaching purposes

    Skoczen, A.; Machowski, W.; Kaprzyk, S.

    1990-07-01

    Computer program aiming at application in quantum mechanics didactics has been proposed. This program can generate the moving pictures of one-dimensional quantum mechanics scattering phenomena. Constructions of this program provide two options. In the first option the wave packet is generated in infinite one-dimensional well which has walls on the borders of graphic window. In the second option the square potential barrier is located in this well and transmission and reflection of wave packet are shown. We have selected a Gaussian wave packet to represent the initial state of the particle. The wave equation is solved numerically by a method discussed in detail. Solutions for the succesive time moments are graphically presented on the monitor screen. In this way observer can watch whole time-development of physical system. Graphically presented results are physically realistic when program parameters satisfy conditions discussed in this paper. (author)

  12. REVIEW One-Dimensional Dynamical Modeling of Earthquakes: A Review

    Jeen-Hwa Wang

    2008-01-01

    Full Text Available Studies of the power-law relations of seismicity and earthquake source parameters based on the one-dimensional (1-D Burridge-Knopoff¡¦s (BK dynamical lattice model, especially those studies conducted by Taiwan¡¦s scientists, are reviewed in this article. In general, velocity- and/or state-dependent friction is considered to control faulting. A uniform distribution of breaking strengths (i.e., the static friction strength is taken into account in some studies, and inhomogeneous distributions in others. The scaling relations in these studies include: Omori¡¦s law, the magnitude-frequency or energy-frequency relation, the relation between source duration time and seismic moment, the relation between rupture length and seismic moment, the frequency-length relation, and the source power spectra. The main parameters of the one-dimensional (1-D Burridge-Knopoff¡¦s (BK dynamical lattice model include: the decreasing rate (r of dynamic friction strength with sliding velocity; the type and degree of heterogeneous distribution of the breaking strengths, the stiffness ratio (i.e., the ratio between the stiffness of the coil spring connecting two mass elements and that of the leaf spring linking a mass element and the moving plate; the frictional drop ratio of the minimum dynamic friction strength to the breaking strength; and the maximum breaking strength. For some authors, the distribution of the breaking strengths was considered to be a fractal function. Hence, the fractal dimension of such a distribution is also a significant parameter. Comparison between observed scaling laws and simulation results shows that the 1-D BK dynamical lattice model acceptably approaches fault dynamics.

  13. One-dimensional reduction of viscous jets. I. Theory

    Pitrou, Cyril

    2018-04-01

    We build a general formalism to describe thin viscous jets as one-dimensional objects with an internal structure. We present in full generality the steps needed to describe the viscous jets around their central line, and we argue that the Taylor expansion of all fields around that line is conveniently expressed in terms of symmetric trace-free tensors living in the two dimensions of the fiber sections. We recover the standard results of axisymmetric jets and we report the first and second corrections to the lowest order description, also allowing for a rotational component around the axis of symmetry. When applied to generally curved fibers, the lowest order description corresponds to a viscous string model whose sections are circular. However, when including the first corrections, we find that curved jets generically develop elliptic sections. Several subtle effects imply that the first corrections cannot be described by a rod model since it amounts to selectively discard some corrections. However, in a fast rotating frame, we find that the dominant effects induced by inertial and Coriolis forces should be correctly described by rod models. For completeness, we also recover the constitutive relations for forces and torques in rod models and exhibit a missing term in the lowest order expression of viscous torque. Given that our method is based on tensors, the complexity of all computations has been beaten down by using an appropriate tensor algebra package such as xAct, allowing us to obtain a one-dimensional description of curved viscous jets with all the first order corrections consistently included. Finally, we find a description for straight fibers with elliptic sections as a special case of these results, and recover that ellipticity is dynamically damped by surface tension. An application to toroidal viscous fibers is presented in the companion paper [Pitrou, Phys. Rev. E 97, 043116 (2018), 10.1103/PhysRevE.97.043116].

  14. Korteweg de Vries Description of One-Dimensional Superfluid Fermi Gases

    Xu Yan-Xia; Duan Wen-Shan

    2011-01-01

    We study one-dimensional matter-wave pulses in cigar-shaped superfluid Fermi gases, including the linear and nonlinear waves of the system. A Korteweg de Vries (KdV) solitary wave is obtained for the superfluid Fermi gases in the limited case of a BEC regime, a BCS regime and unitarity. The dependences of the propagation velocity, amplitude and the width of the solitary wave on the dimensionless interaction parameter y = 1/(k F a sc ) are given for the limited cases of BEC and unitarity. (physics of gases, plasmas, and electric discharges)

  15. Metal-insulator transition in one-dimensional lattices with chaotic energy sequences

    Pinto, R.A.; Rodriguez, M.; Gonzalez, J.A.; Medina, E.

    2005-01-01

    We study electronic transport through a one-dimensional array of sites by using a tight binding Hamiltonian, whose site-energies are drawn from a chaotic sequence. The correlation degree between these energies is controlled by a parameter regulating the dynamic Lyapunov exponent measuring the degree of chaos. We observe the effect of chaotic sequences on the localization length, conductance, conductance distribution and wave function, finding evidence of a metal-insulator transition (MIT) at a critical degree of chaos. The one-dimensional metallic phase is characterized by a Gaussian conductance distribution and exhibits a peculiar non-selfaveraging

  16. Metal-insulator transition in one-dimensional lattices with chaotic energy sequences

    Pinto, R.A. [Laboratorio de Fisica Estadistica, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela)]. E-mail: ripinto@ivic.ve; Rodriguez, M. [Laboratorio de Fisica Estadistica, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela); Gonzalez, J.A. [Laboratorio de Fisica Computacional, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela); Medina, E. [Laboratorio de Fisica Estadistica, Centro de Fisica, Instituto Venezolano de Investigaciones Cientificas, Apartado 21827, Caracas 1020-A (Venezuela)

    2005-06-20

    We study electronic transport through a one-dimensional array of sites by using a tight binding Hamiltonian, whose site-energies are drawn from a chaotic sequence. The correlation degree between these energies is controlled by a parameter regulating the dynamic Lyapunov exponent measuring the degree of chaos. We observe the effect of chaotic sequences on the localization length, conductance, conductance distribution and wave function, finding evidence of a metal-insulator transition (MIT) at a critical degree of chaos. The one-dimensional metallic phase is characterized by a Gaussian conductance distribution and exhibits a peculiar non-selfaveraging.

  17. GITTAM program for numerical simulation of one-dimensional targets TIS. Part 3

    Basko, M.M.; Sokolovskij, M.V.

    1989-01-01

    Results of testing calculations according to GITTAM program, developed for numeric simulation of one-dimensional thermonuclear targets of heavy-ion synthesis are presented. Finite-difference method for solving a system of one-dimensional hydrodynamics equations with heat conductivity, radiation diffusion and thermonuclear combustion is used in the GITTAM program. In the tests presented, based on simple automodel solutions, adiabatic motion as well as distribution of shock, thermal and radial waves in gas with simple polytron state equation is investigated. 3 refs.; 6 figs

  18. Accurate correlation energies in one-dimensional systems from small system-adapted basis functions

    Baker, Thomas E.; Burke, Kieron; White, Steven R.

    2018-02-01

    We propose a general method for constructing system-dependent basis functions for correlated quantum calculations. Our construction combines features from several traditional approaches: plane waves, localized basis functions, and wavelets. In a one-dimensional mimic of Coulomb systems, it requires only 2-3 basis functions per electron to achieve high accuracy, and reproduces the natural orbitals. We illustrate its effectiveness for molecular energy curves and chains of many one-dimensional atoms. We discuss the promise and challenges for realistic quantum chemical calculations.

  19. RETRAN-02 one-dimensional kinetics model: a review

    Gose, G.C.; McClure, J.A.

    1986-01-01

    RETRAN-02 is a modular code system that has been designed for one-dimensional, transient thermal-hydraulics analysis. In RETRAN-02, core power behavior may be treated using a one-dimensional reactor kinetics model. This model allows the user to investigate the interaction of time- and space-dependent effects in the reactor core on overall system behavior for specific LWR operational transients. The purpose of this paper is to review the recent analysis and development activities related to the one dimensional kinetics model in RETRAN-02

  20. Plasma properties of quasi-one-dimensional ring

    Shmelev, G M

    2001-01-01

    The plasma properties of the quasi-one-dimensional ring in the threshold cases of low and high frequencies, corresponding to the plasma oscillations and dielectric relaxation are studied within the frames of the classical approach. The plasma oscillations spectrum and the electron dielectric relaxation frequency in the quasi-one-dimensional ring are calculated. The plasmons spectrum equidistance is identified. It is shown , that in contrast to the three-dimensional case there takes place the dielectric relaxation dispersion, wherefrom there follows the possibility of studying the carriers distribution in the quasi-one-dimensional rings through the method of the dielectric relaxation spectroscopy

  1. Explicit Solutions for One-Dimensional Mean-Field Games

    Prazeres, Mariana

    2017-01-01

    In this thesis, we consider stationary one-dimensional mean-field games (MFGs) with or without congestion. Our aim is to understand the qualitative features of these games through the analysis of explicit solutions. We are particularly interested

  2. Negative differential resistance in a one-dimensional molecular wire ...

    voltage characteristics of a one-dimensional molecular wire with odd number of ... lem, although interesting both from a fundamental point of view and in terms of ..... SKP acknowledges the DST, Government of India, for financial support.

  3. The one-dimensional extended Bose–Hubbard model

    Unknown

    method to obtain the zero-temperature phase diagram of the one-dimensional, extended ... Progress in this field has been driven by an interplay between ... superconductor-insulator transition in thin films of superconducting materials like bis-.

  4. One-dimensional reactor kinetics model for RETRAN

    Gose, G.C.; Peterson, C.E.; Ellis, N.L.; McClure, J.A.

    1981-01-01

    This paper describes a one-dimensional spatial neutron kinetics model that was developed for the RETRAN code. The RETRAN -01 code has a point kinetics model to describe the reactor core behavior during thermal-hydraulic transients. A one-dimensional neutronics model has been developed for RETRAN-02. The ability to account for flux shape changes will permit an improved representation of the thermal and hydraulic feedback effects for many operational transients. 19 refs

  5. One dimensional Bosons: From Condensed Matter Systems to Ultracold Gases

    Cazalilla, M. A.; Citro, R.; Giamarchi, T.; Orignac, E.; Rigol, M.

    2011-01-01

    The physics of one-dimensional interacting bosonic systems is reviewed. Beginning with results from exactly solvable models and computational approaches, the concept of bosonic Tomonaga-Luttinger liquids relevant for one-dimensional Bose fluids is introduced, and compared with Bose-Einstein condensates existing in dimensions higher than one. The effects of various perturbations on the Tomonaga-Luttinger liquid state are discussed as well as extensions to multicomponent and out of equilibrium ...

  6. One dimensional models of excitons in carbon nanotubes

    Cornean, Horia Decebal; Duclos, P.; Pedersen, Thomas Garm

    Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable.......Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable....

  7. One-Dimensional Creativity: A Marcusean Critique of Work and Play in the Video Game Industry

    Ergin Bulut

    2018-06-01

    Full Text Available Creativity is at the heart of the video game industry. Industry professionals, especially those producing blockbuster games for the triple-A market, speak fondly of their creative labour practices, flexible work schedules, and playful workplaces. However, a cursory glance at major triple-A franchises reveals the persistence of sequel game production and a homogeneity in genres and narratives. Herbert Marcuse’s critique of one-dimensionality may help to account for this discrepancy between the workers’ creative aspirations and the dominant homogeneity in game aesthetics. What I call ‘one-dimensional creativity’ defines the essence of triple-A game production. In the name of extolling the pleasure principle at work, one-dimensional creativity eliminates the reality principle, but only superficially. One-dimensional creativity gives game developers the opportunity to express themselves, but it is still framed by a particular technological rationality that prioritises profits over experimental art. One-dimensional creativity negates potential forms of creativity that might emerge outside the industry’s hit-driven logics. Conceptually, ‘one-dimensional creativity’ renders visible the instrumentalisation of play and the conservative design principles of triple-A game production – a production that is heavily structured with technological performance, better graphics, interactivity, and speed. Multi-dimensional video game production and aesthetics, the opposite of one-dimensional creativity, is emerging from the DIY game production scene, which is more invested in game narratives and aesthetics outside the dominant logics of one-dimensionality in triple-A game production.

  8. One-Dimensional Electron Transport Layers for Perovskite Solar Cells

    Ujwal K. Thakur

    2017-04-01

    Full Text Available The electron diffusion length (Ln is smaller than the hole diffusion length (Lp in many halide perovskite semiconductors meaning that the use of ordered one-dimensional (1D structures such as nanowires (NWs and nanotubes (NTs as electron transport layers (ETLs is a promising method of achieving high performance halide perovskite solar cells (HPSCs. ETLs consisting of oriented and aligned NWs and NTs offer the potential not merely for improved directional charge transport but also for the enhanced absorption of incoming light and thermodynamically efficient management of photogenerated carrier populations. The ordered architecture of NW/NT arrays affords superior infiltration of a deposited material making them ideal for use in HPSCs. Photoconversion efficiencies (PCEs as high as 18% have been demonstrated for HPSCs using 1D ETLs. Despite the advantages of 1D ETLs, there are still challenges that need to be overcome to achieve even higher PCEs, such as better methods to eliminate or passivate surface traps, improved understanding of the hetero-interface and optimization of the morphology (i.e., length, diameter, and spacing of NWs/NTs. This review introduces the general considerations of ETLs for HPSCs, deposition techniques used, and the current research and challenges in the field of 1D ETLs for perovskite solar cells.

  9. Negative refraction angular characterization in one-dimensional photonic crystals.

    Jesus Eduardo Lugo

    2011-04-01

    Full Text Available Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs.By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone.Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.

  10. Interfacial Thermal Transport via One-Dimensional Atomic Junction Model

    Guohuan Xiong

    2018-03-01

    Full Text Available In modern information technology, as integration density increases rapidly and the dimension of materials reduces to nanoscale, interfacial thermal transport (ITT has attracted widespread attention of scientists. This review introduces the latest theoretical development in ITT through one-dimensional (1D atomic junction model to address the thermal transport across an interface. With full consideration of the atomic structures in interfaces, people can apply the 1D atomic junction model to investigate many properties of ITT, such as interfacial (Kapitza resistance, nonlinear interface, interfacial rectification, and phonon interference, and so on. For the ballistic ITT, both the scattering boundary method (SBM and the non-equilibrium Green’s function (NEGF method can be applied, which are exact since atomic details of actual interfaces are considered. For interfacial coupling case, explicit analytical expression of transmission coefficient can be obtained and it is found that the thermal conductance maximizes at certain interfacial coupling (harmonic mean of the spring constants of the two leads and the transmission coefficient is not a monotonic decreasing function of phonon frequency. With nonlinear interaction—phonon–phonon interaction or electron–phonon interaction at interface, the NEGF method provides an efficient way to study the ITT. It is found that at weak linear interfacial coupling, the nonlinearity can improve the ITT, but it depresses the ITT in the case of strong-linear coupling. In addition, the nonlinear interfacial coupling can induce thermal rectification effect. For interfacial materials case which can be simulated by a two-junction atomic chain, phonons show interference effect, and an optimized thermal coupler can be obtained by tuning its spring constant and atomic mass.

  11. Strong chaos in one-dimensional quantum system

    Yang, C.-D.; Wei, C.-H.

    2008-01-01

    According to the Poincare-Bendixson theorem, a minimum of three autonomous equations is required to exhibit deterministic chaos. Because a one-dimensional quantum system is described by only two autonomous equations using de Broglie-Bohm's trajectory interpretation, chaos in one-dimensional quantum systems has long been considered impossible. We will prove in this paper that chaos phenomenon does exist in one-dimensional quantum systems, if the domain of quantum motions is extended to complex space by noting that the quantum world is actually characterized by a four-dimensional complex spacetime according to the E (∞) theory. Furthermore, we point out that the interaction between the real and imaginary parts of complex trajectories produces a new chaos phenomenon unique to quantum systems, called strong chaos, which describes the situation that quantum trajectories may emerge and diverge spontaneously without any perturbation in the initial position

  12. Absorption in one-dimensional metallic-dielectric photonic crystals

    Yu Junfei; Shen Yifeng; Liu Xiaohan; Fu Rongtang; Zi Jian; Zhu Zhiqiang

    2004-01-01

    We show theoretically that the absorption of one-dimensional metallic-dielectric photonic crystals can be enhanced considerably over the corresponding constituent metal. By properly choosing the structural and material parameters, the absorption of one-dimensional metallic-dielectric photonic crystals can be enhanced by one order of magnitude in the visible and in the near infrared regions. It is found that the absorptance of such photonic crystals increases with increasing number of periods. Rules on how to obtain a absorption enhancement in a certain frequency range are discussed. (letter to the editor)

  13. One-dimensional models of excitons in carbon nanotubes

    Cornean, Horia Decebal; Duclos, Pierre; Pedersen, Thomas Garm

    2004-01-01

    Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one-dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable.......Excitons in carbon nanotubes may be modeled by two oppositely charged particles living on the surface of a cylinder. We derive three one-dimensional effective Hamiltonians which become exact as the radius of the cylinder vanishes. Two of them are solvable....

  14. Large-Scale Description of Interacting One-Dimensional Bose Gases: Generalized Hydrodynamics Supersedes Conventional Hydrodynamics

    Doyon, Benjamin; Dubail, Jérôme; Konik, Robert; Yoshimura, Takato

    2017-11-01

    The theory of generalized hydrodynamics (GHD) was recently developed as a new tool for the study of inhomogeneous time evolution in many-body interacting systems with infinitely many conserved charges. In this Letter, we show that it supersedes the widely used conventional hydrodynamics (CHD) of one-dimensional Bose gases. We illustrate this by studying "nonlinear sound waves" emanating from initial density accumulations in the Lieb-Liniger model. We show that, at zero temperature and in the absence of shocks, GHD reduces to CHD, thus for the first time justifying its use from purely hydrodynamic principles. We show that sharp profiles, which appear in finite times in CHD, immediately dissolve into a higher hierarchy of reductions of GHD, with no sustained shock. CHD thereon fails to capture the correct hydrodynamics. We establish the correct hydrodynamic equations, which are finite-dimensional reductions of GHD characterized by multiple, disjoint Fermi seas. We further verify that at nonzero temperature, CHD fails at all nonzero times. Finally, we numerically confirm the emergence of hydrodynamics at zero temperature by comparing its predictions with a full quantum simulation performed using the NRG-TSA-abacus algorithm. The analysis is performed in the full interaction range, and is not restricted to either weak- or strong-repulsion regimes.

  15. Effects of Interaction Imbalance in a Strongly Repulsive One-Dimensional Bose Gas

    Barfknecht, R. E.; Foerster, A.; Zinner, N. T.

    2018-05-01

    We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calculate the time evolution of the system and show that, for a certain ratio of interactions, the minority population travels through the system as an effective wave packet.

  16. One-dimensional adiabatic model of waterhammer; Endodimenzionalni adiabatni model vodnega udara

    Bizjak, S [Institut Jozef Stefan, Ljubljana (Yugoslavia)

    1984-07-01

    Program WH was developed to calculate transient pressure and velocities in hydraulic networks. It is based on one-dimensional approximation of conservation laws of mass and momentum. the energy equation is ignored which means that heat transfer effects are no included. When calculating the velocity of pressure wave, compressibility of liquid, elasticity of pipe and possible minimal presence of gas in bubble or dissolved form are included. (author)

  17. A Full-wave Model for Wave Propagation and Dissipation in the Inner Magnetosphere Using the Finite Element Method

    Valeo, Ernest; Johnson, Jay R.; Kim, Eun-Hwa; Phillips, Cynthia

    2012-01-01

    A wide variety of plasma waves play an important role in the energization and loss of particles in the inner magnetosphere. Our ability to understand and model wave-particle interactions in this region requires improved knowledge of the spatial distribution and properties of these waves as well as improved understanding of how the waves depend on changes in solar wind forcing and/or geomagnetic activity. To this end, we have developed a two-dimensional, finite element code that solves the full wave equations in global magnetospheric geometry. The code describes three-dimensional wave structure including mode conversion when ULF, EMIC, and whistler waves are launched in a two-dimensional axisymmetric background plasma with general magnetic field topology. We illustrate the capabilities of the code by examining the role of plasmaspheric plumes on magnetosonic wave propagation; mode conversion at the ion-ion and Alfven resonances resulting from external, solar wind compressions; and wave structure and mode conversion of electromagnetic ion cyclotron waves launched in the equatorial magnetosphere, which propagate along the magnetic field lines toward the ionosphere. We also discuss advantages of the finite element method for resolving resonant structures, and how the model may be adapted to include nonlocal kinetic effects.

  18. Electromagnetic waves in irregular multilayered spheroidal structures of finite conductivity: full wave solutions

    Bahar, E.

    1976-01-01

    The propagation of electromagnetic waves excited by electric dipoles oriented along the axis of multilayered spheroidal structures of finite conductivity is investigated. The electromagnetic parameters and the thickness of the layers of the structure are assumed to be functions of the latitude. In the analysis, electric and magnetic field transforms that constitute a discrete and a continuous spectrum of spherical waves are used to provide a suitable basis for the expansion of the electromagnetic fields at any point in the irregular spheroidal structure. For spheroidal structures with good conducting cores, the terms in the solutions associated with the continuous part of the wave spectrum vanish. In general, however, when the skin depth for the core is large compared to its dimensions or when the sources are located in the core of the structure and propagation in the core is of special interest, the contribution from the continuous part of the wave spectrum cannot be neglected. At each interface between the layers of the irregular spheroidal structure, exact boundary conditions are imposed. Since the terms of the field expansions in the irregular structure do not individually satisfy the boundary conditions, Maxwell's equations are reduced to sets of coupled ordinary first-order differential equations for the wave amplitudes. The solutions are shown to satisfy the reciprocity relationships in electromagnetic theory. The analysis may be applied to problems of radio wave propagation in a nonuniform model of the earth-ionosphere waveguide, particularly when focusing effects at the antipodes are important

  19. Time-Domain Techniques for Computation and Reconstruction of One-Dimensional Profiles

    M. Rahman

    2005-01-01

    Full Text Available This paper presents a time-domain technique to compute the electromagnetic fields and to reconstruct the permittivity profile within a one-dimensional medium of finite length. The medium is characterized by a permittivity as well as conductivity profile which vary only with depth. The discussed scattering problem is thus one-dimensional. The modeling tool is divided into two different schemes which are named as the forward solver and the inverse solver. The task of the forward solver is to compute the internal fields of the specimen which is performed by Green’s function approach. When a known electromagnetic wave is incident normally on the media, the resulting electromagnetic field within the media can be calculated by constructing a Green’s operator. This operator maps the incident field on either side of the medium to the field at an arbitrary observation point. It is nothing but a matrix of integral operators with kernels satisfying known partial differential equations. The reflection and transmission behavior of the medium is also determined from the boundary values of the Green's operator. The inverse solver is responsible for solving an inverse scattering problem by reconstructing the permittivity profile of the medium. Though it is possible to use several algorithms to solve this problem, the invariant embedding method, also known as the layer-stripping method, has been implemented here due to the advantage that it requires a finite time trace of reflection data. Here only one round trip of reflection data is used, where one round trip is defined by the time required by the pulse to propagate through the medium and back again. The inversion process begins by retrieving the reflection kernel from the reflected wave data by simply using a deconvolution technique. The rest of the task can easily be performed by applying a numerical approach to determine different profile parameters. Both the solvers have been found to have the

  20. Approximate characteristics for one-dimensional two-phase flows

    Sarayloo, A.; Peddleson, J.

    1985-01-01

    An approximate method for determining the characteristics associated with one-dimensional particulate two-phase flow models is presented. The method is based on iteration and is valid for small particulate volume fractions. The method is applied to several special cases involving incompressible particles suspended in a gas. The influences of certain changes in the physical model are investigated

  1. Correlation Functions of the One-Dimensional Attractive Bose Gas

    Calabrese, Pasquale; Caux, Jean-Sebastien

    2007-01-01

    The zero-temperature correlation functions of the one-dimensional attractive Bose gas with a delta-function interaction are calculated analytically for any value of the interaction parameter and number of particles, directly from the integrability of the model. We point out a number of interesting features, including zero recoil energy for a large number of particles, analogous to the Moessbauer effect

  2. Analytical solutions of one-dimensional advection–diffusion

    Analytical solutions are obtained for one-dimensional advection –diffusion equation with variable coefficients in a longitudinal finite initially solute free domain,for two dispersion problems.In the first one,temporally dependent solute dispersion along uniform flow in homogeneous domain is studied.In the second problem the ...

  3. Quantitative hyperbolicity estimates in one-dimensional dynamics

    Day, S; Kokubu, H; Pilarczyk, P; Luzzatto, S; Mischaikow, K; Oka, H

    2008-01-01

    We develop a rigorous computational method for estimating the Lyapunov exponents in uniformly expanding regions of the phase space for one-dimensional maps. Our method uses rigorous numerics and graph algorithms to provide results that are mathematically meaningful and can be achieved in an efficient way

  4. Quasi-one-dimensional scattering in a discrete model

    Valiente, Manuel; Mølmer, Klaus

    2011-01-01

    We study quasi-one-dimensional scattering of one and two particles with short-range interactions on a discrete lattice model in two dimensions. One of the directions is tightly confined by an arbitrary trapping potential. We obtain the collisional properties of these systems both at finite and zero...

  5. Structure Variation from One-Dimensional Chain to Three ...

    WEN-XUAN LI, XIAO-MIN GU, WEN-LI ZHANG and LIANG NI. School of Chemistry ... Compound 1 possesses one-dimensional chain structure, and expands into ..... sis of fine chemicals and pharmaceuticals.30 The results were summarized ...

  6. Current-Voltage Characteristics of Quasi-One-Dimensional Superconductors

    Vodolazov, D.Y.; Peeters, F.M.; Piraux, L.

    2003-01-01

    The current-voltage (I-V) characteristics of quasi-one-dimensional superconductors were discussed. The I-V characteristics exhibited an unusual S behavior. The dynamics of superconducting condensate and the existence of two different critical currents resulted in such an unusual behavior....

  7. Diffusive transport in a one dimensional disordered potential involving correlations

    Monthus, C.; Paris-6 Univ., 75

    1995-03-01

    Transport properties of one dimensional Brownian diffusion under the influence of a quenched random force, distributed as a two-level Poisson process is discussed. Large time scaling laws of the position of the Brownian particle, and the probability distribution of the stationary flux going through a sample between two prescribed concentrations are studied. (author) 14 refs.; 3 figs

  8. Appropriateness of one-dimensional calculations for repository analysis

    Eaton, R.R.

    1994-01-01

    This paper brings into focus the results of numerous studies that have addressed issues associated with the validity of assumptions which are used to justify reducing the dimensionality of numerical calculations of water flow through Yucca Mountain, NV. It is shown that in many cases, one-dimensional modeling is more rigorous than previously assumed

  9. One-dimensional position readout from microchannel plates

    Connell, K.A.; Przybylski, M.M.

    1982-01-01

    The development of a one-dimensional position readout system with microchannel plates, is described, for heavy ion detectors for use in a particle time-of-flight telescope and as a position sensitive device in front of an ionisation counter at the Nuclear Structure Facility. (U.K.)

  10. Lekhnitskii's formalism of one-dimensional quasicrystals and its ...

    To illustrate its utility, the generalized Lekhnitskii's formal- ism is used to analyse the coupled phonon and phason fields in an infinite quasicrystal medium con- taining an elliptic rigid inclusion. Keywords. Generalized Lekhnitskii's formalism; one-dimensional quasicrystals; plane problems; elliptic inclusion. PACS Nos 61.44.

  11. Backward scattering in the one-dimensional Fermi gas

    Apostol, M.

    1980-05-01

    The Ward identity is derived for non-relativistic fermions with two-body spin-independent interaction. Using this identity for the one-dimensional Fermi gas with backward scattering the equations of the perturbation theory are solved for the effective interaction and the collective excitations of the particle density fluctuations are obtained. (author)

  12. Simulation of the diffraction pattern of one dimensional quasicrystal ...

    The effects of the variation of atomic spacing ratio of a one dimensional quasicrystal material are investigated. The work involves the use of the solid state simulation code, Laue written by Silsbee and Drager. We are able to observe the general features of the diffraction pattern by a quasicrystal. In addition, it has been found ...

  13. Monte Carlo investigation of the one-dimensional Potts model

    Karma, A.S.; Nolan, M.J.

    1983-01-01

    Monte Carlo results are presented for a variety of one-dimensional dynamical q-state Potts models. Our calculations confirm the expected universal value z = 2 for the dynamic scaling exponent. Our results also indicate that an increase in q at fixed correlation length drives the dynamics into the scaling regime

  14. One-dimensional autonomous systems and dissipative systems

    Lopez, G.

    1996-01-01

    The Lagrangian and the Generalized Linear Momentum are given in terms of a constant of motion for a one-dimensional autonomous system. The possibility of having an explicit Hamiltonian expression is also analyzed. The approach is applied to some dissipative systems. Copyright copyright 1996 Academic Press, Inc

  15. Quantum transport in strongly interacting one-dimensional nanostructures

    Agundez, R.R.

    2015-01-01

    In this thesis we study quantum transport in several one-dimensional systems with strong electronic interactions. The first chapter contains an introduction to the concepts treated throughout this thesis, such as the Aharonov-Bohm effect, the Kondo effect, the Fano effect and quantum state transfer.

  16. Statistics of resonances in one-dimensional continuous systems

    Vol. 73, No. 3. — journal of. September 2009 physics pp. 565–572. Statistics of resonances in one-dimensional continuous systems. JOSHUA FEINBERG. Physics Department, University of Haifa at Oranim, Tivon 36006, Israel ..... relativistic quantum mechanics (Israel Program for Scientific Translations, Jerusalem,. 1969).

  17. Statistical mechanics of quantum one-dimensional damped harmonic oscillator

    Borges, E.N.M.; Borges, O.N.; Ribeiro, L.A.A.

    1985-01-01

    We calculate the thermal correlation functions of the one-dimensional damped harmonic oscillator in contact with a reservoir, in an exact form by applying Green's function method. In this way the thermal fluctuations are incorporated in the Caldirola-Kanai Hamiltonian

  18. Anomalous heat conduction in a one-dimensional ideal gas.

    Casati, Giulio; Prosen, Tomaz

    2003-01-01

    We provide firm convincing evidence that the energy transport in a one-dimensional gas of elastically colliding free particles of unequal masses is anomalous, i.e., the Fourier law does not hold. Our conclusions are confirmed by a theoretical and numerical analysis based on a Green-Kubo-type approach specialized to momentum-conserving lattices.

  19. Relativistic band gaps in one-dimensional disordered systems

    Clerk, G.J.; McKellar, B.H.J.

    1992-01-01

    Conditions for the existence of band gaps in a one-dimensional disordered array of δ-function potentials possessing short range order are developed in a relativistic framework. Both Lorentz vector and scalar type potentials are treated. The relationship between the energy gaps and the transmission properties of the array are also discussed. 20 refs., 2 figs

  20. The electromagnetic Brillouin precursor in one-dimensional photonic crystals

    Uitham, R.; Hoenders, B. J.

    2008-01-01

    We have calculated the electromagnetic Brillouin precursor that arises in a one-dimensional photonic crystal that consists of two homogeneous slabs which each have a single electron resonance. This forerunner is compared with the Brillouin precursor that arises in a homogeneous double-electron

  1. On the quantisation of one-dimensional bags

    Fairley, G.T.; Squires, E.J.

    1976-01-01

    The quantisation of one-dimensional MIT bags by expanding the fields as a sum of classical modes and truncating the series after the first term is discussed. The lowest states of a bag in a world containing two scalar quark fields are obtained. Problems associated with the zero-point oscillations of the field are discussed. (Auth.)

  2. The appropriateness of one-dimensional Yucca Mountain hydrologic calculations

    Eaton, R.R.

    1993-07-01

    This report brings into focus the results of numerous studies that have addressed issues associated with the validity of assumptions which are used to justify reducing the dimensionality of numerical calculations of water flow through Yucca Mountain, NV. it is shown that, in many cases, one-dimensional modeling is more rigorous than previously assumed

  3. Light propagation in one-dimensional porous silicon complex systems

    Oton, C.J.; Dal Negro, L.; Gaburro, Z.; Pavesi, L.; Johnson, P.J.; Lagendijk, Aart; Wiersma, D.S.

    2003-01-01

    We discuss the optical properties of one-dimensional complex dielectric systems, in particular the time-resolved transmission through thick porous silicon quasiperiodic multi-layers. Both in numerical calculations and experiments we find dramatic distortion effects, i.e. pulse stretching and

  4. Analytical approach for collective diffusion: one-dimensional heterogeneous lattice

    Tarasenko, Alexander

    2016-01-01

    Roč. 144, č. 14 (2016), 1-11, č. článku 144105. ISSN 0021-9606 Institutional support: RVO:68378271 Keywords : diffusion * Monte Carlo simulations * one-dimensional heterogeneous lattice Subject RIV: BE - Theoretical Physics Impact factor: 2.965, year: 2016

  5. Approximate Approaches to the One-Dimensional Finite Potential Well

    Singh, Shilpi; Pathak, Praveen; Singh, Vijay A.

    2011-01-01

    The one-dimensional finite well is a textbook problem. We propose approximate approaches to obtain the energy levels of the well. The finite well is also encountered in semiconductor heterostructures where the carrier mass inside the well (m[subscript i]) is taken to be distinct from mass outside (m[subscript o]). A relevant parameter is the mass…

  6. Toward precise solution of one-dimensional velocity inverse problems

    Gray, S.; Hagin, F.

    1980-01-01

    A family of one-dimensional inverse problems are considered with the goal of reconstructing velocity profiles to reasonably high accuracy. The travel-time variable change is used together with an iteration scheme to produce an effective algorithm for computation. Under modest assumptions the scheme is shown to be convergent

  7. Multi-directional plasmonic surface-wave splitters with full bandwidth isolation

    Gao, Zhen; Gao, Fei; Zhang, Baile

    2016-01-01

    We present a multidirectional plasmonic surface-wave splitter with full bandwidth isolation experimentally based on coupled defect surface modes in a surface-wave photonic crystal. In contrast to conventional plasmonic surface-wave frequency splitters with polaritonic dispersion relations that overlap at low frequencies, this multidirectional plasmonic surface-wave splitter based on coupled defect surface modes can split different frequency bands into different waveguide branches without bandwidth overlap. Transmission spectra and near-field imaging measurements have been implemented in the microwave frequencies to verify the performance of the multidirectional plasmonic surface-wave splitter. This surface wave structure can be used as a plasmonic wavelength-division multiplexer that may find potential applications in the surface-wave integrated circuits from microwave to terahertz frequencies.

  8. A full wave code for ion cyclotron waves in toroidal plasmas

    Brambilla, M.

    1996-02-01

    The code TORIC solves the finite Larmor radius wave equations in the ion cyclotron frequency range in arbitrary axisymmetric toroidal geometry. The model used describes the compressional and torsional Alfven waves (or, depending on the parallel phase velocity, the kinetic counterpart of the latter), and ion Bernstein waves excited by mode conversion near the first ion cyclotron harmonic. In the ion response the broadening of the absorption regions due to the finite width of the cyclotron resonance of individual ions in toroidal geometry is taken into account. The parallel component of the wave electric field is evaluated on the same footing as the transverse ones; the response of the electrons includes Landau damping, Transit Time damping and the mixed term. The numerical approach uses a spectral representation of the solution in the poloidal angle θ, and cubic finite elements in the radial variable ψ. Great flexibility is provided in the way ion Bernstein waves excited by mode conversion are damped when their wavelength becomes comparable with the ion Larmor radius, in the regularization of Alfven resonances, and in the treatment of the outer plasma layers. As an option, we have also implemented the Order Reduction Algorithm, which provides a particularly fast, yet accurate evaluation of the power deposition profiles in toroidal geometry. Thee present report describes the model and its numerical implementation, and provides the information needed to use the code. A few examples illustrating applications of TORIC are also included. (orig.)

  9. Reflection and transmission of full-vector X-waves normally incident on dielectric half spaces

    Salem, Mohamed

    2011-08-01

    The reflection and transmission of full-vector X-Waves incident normally on a planar interface between two lossless dielectric half-spaces are investigated. Full-vector X-Waves are obtained by superimposing transverse electric and magnetic polarization components, which are derived from the scalar X-Wave solution. The analysis of transmission and reflection is carried out via a straightforward but yet effective method: First, the X-Wave is decomposed into vector Bessel beams via the Bessel-Fourier transform. Then, the reflection and transmission coefficients of the beams are obtained in the spectral domain. Finally, the transmitted and reflected X-Waves are obtained via the inverse Bessel-Fourier transform carried out on the X-wave spectrum weighted with the corresponding coefficient. © 2011 IEEE.

  10. A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers.

    de Jong, J A; Wijnant, Y H; de Boer, A

    2014-03-01

    A one-dimensional (1D) laminar oscillating flow heat transfer model is derived and applied to parallel-plate thermoacoustic heat exchangers. The model can be used to estimate the heat transfer from the solid wall to the acoustic medium, which is required for the heat input/output of thermoacoustic systems. The model is implementable in existing (quasi-)1D thermoacoustic codes, such as DeltaEC. Examples of generated results show good agreement with literature results. The model allows for arbitrary wave phasing; however, it is shown that the wave phasing does not significantly influence the heat transfer.

  11. From lag synchronization to pattern formation in one-dimensional open flow models

    Liu Zengrong; Luo Jigui

    2006-01-01

    In this paper, the relation between synchronization and pattern formation in one-dimensional discrete and continuous open flow models is investigated in detail. Firstly a sufficient condition for globally asymptotical stability of lag/anticipating synchronization among lattices of these models is proved by analytic method. Then, by analyzing and simulating lag/anticipating synchronization in discrete case, three kinds of pattern of wave (it is called wave pattern) travelling in the lattices are discovered. Finally, a proper definition for these kinds of pattern is proposed

  12. One-dimensional velocity model of the Middle Kura Depresion from local earthquakes data of Azerbaijan

    Yetirmishli, G. C.; Kazimova, S. E.; Kazimov, I. E.

    2011-09-01

    We present the method for determining the velocity model of the Earth's crust and the parameters of earthquakes in the Middle Kura Depression from the data of network telemetry in Azerbaijan. Application of this method allowed us to recalculate the main parameters of the hypocenters of the earthquake, to compute the corrections to the arrival times of P and S waves at the observation station, and to significantly improve the accuracy in determining the coordinates of the earthquakes. The model was constructed using the VELEST program, which calculates one-dimensional minimal velocity models from the travel times of seismic waves.

  13. Unconventional Andreev reflection on the quasi-one-dimensional superconductor Nb2PdxSe5

    Yeping Jiang

    2016-04-01

    Full Text Available We have carried out Andreev reflection measurements on point contact junctions between normal metal and single crystals of the quasi-one-dimensional (Q1D superconductor Nb2PdxSe5 (Tc ∼ 5.5 K. The contacts of the junctions were made on either self-cleaved surfaces or crystal edges so that the current flow directions in the two types of junctions are different, and the measurements provide a directional probe for the order parameter of the superconductor. Junctions made in both configurations show typical resistances of ∼20-30 Ohms, and a clear double-gap Andreev reflection feature was consistently observed at low temperatures. Quantitative analysis of the conductance spectrum based on a modified Blonder-Tinkham-Klapwijk (BTK model suggests that the amplitudes of two order parameters may have angular dependence in the a-c plane. Moreover, the gap to transition temperature ratio (Δ/TC for the larger gap is substantially higher than the BCS ratio expected for phonon-mediated s-wave superconductors. We argue that the anisotropic superconducting order parameter and the extremely large gap to transition temperature ratio may be associated with an unconventional pairing mechanism in the inorganic Q1D superconductor.

  14. Strictly local one-dimensional topological quantum error correction with symmetry-constrained cellular automata

    Nicolai Lang, Hans Peter Büchler

    2018-01-01

    Full Text Available Active quantum error correction on topological codes is one of the most promising routes to long-term qubit storage. In view of future applications, the scalability of the used decoding algorithms in physical implementations is crucial. In this work, we focus on the one-dimensional Majorana chain and construct a strictly local decoder based on a self-dual cellular automaton. We study numerically and analytically its performance and exploit these results to contrive a scalable decoder with exponentially growing decoherence times in the presence of noise. Our results pave the way for scalable and modular designs of actively corrected one-dimensional topological quantum memories.

  15. Quantum quenches to the attractive one-dimensional Bose gas: exact results

    Lorenzo Piroli, Pasquale Calabrese, Fabian H. L. Essler

    2016-09-01

    Full Text Available We study quantum quenches to the one-dimensional Bose gas with attractive interactions in the case when the initial state is an ideal one-dimensional Bose condensate. We focus on properties of the stationary state reached at late times after the quench. This displays a finite density of multi-particle bound states, whose rapidity distribution is determined exactly by means of the quench action method. We discuss the relevance of the multi-particle bound states for the physical properties of the system, computing in particular the stationary value of the local pair correlation function $g_2$.

  16. Well-posedness for one-dimensional anisotropic Cahn-Hilliard and Allen-Cahn systems

    Ahmad Makki

    2015-01-01

    Full Text Available Our aim is to prove the existence and uniqueness of solutions for one-dimensional Cahn-Hilliard and Allen-Cahn type equations based on a modification of the Ginzburg-Landau free energy proposed in [8]. In particular, the free energy contains an additional term called Willmore regularization and takes into account strong anisotropy effects.

  17. Database of full-scale laboratory experiments on wave-driven sand transport processes

    van der Werf, Jebbe J.; Schretlen, Johanna Lidwina Maria; Ribberink, Jan S.; O'Donoghue, Tom

    2009-01-01

    A new database of laboratory experiments involving sand transport processes over horizontal, mobile sand beds under full-scale non-breaking wave and non-breaking wave-plus-current conditions is described. The database contains details of the flow and bed conditions, information on which quantities

  18. Reflection and transmission of normally incident full-vector X waves on planar interfaces

    Salem, Mohamed; Bagci, Hakan

    2011-01-01

    The reflection and transmission of full-vector X waves normally incident on planar half-spaces and slabs are studied. For this purpose, X waves are expanded in terms of weighted vector Bessel beams; this new decomposition and reconstruction method

  19. Bound states of Dipolar Bosons in One-dimensional Systems

    G. Volosniev, A.; R. Armstrong, J.; V. Fedorov, D.

    2013-01-01

    that in the weakly-coupled limit the inter-tube interaction is similar to a zero-range term with a suitable rescaled strength. This allows us to address the corresponding many-body physics of the system by constructing a model where bound chains with one molecule in each tube are the effective degrees of freedom......We consider one-dimensional tubes containing bosonic polar molecules. The long-range dipole-dipole interactions act both within a single tube and between different tubes. We consider arbitrary values of the externally aligned dipole moments with respect to the symmetry axis of the tubes. The few....... This model can be mapped onto one-dimensional Hamiltonians for which exact solutions are known....

  20. Versatile hydrothermal synthesis of one-dimensional composite structures

    Luo, Yonglan

    2008-12-01

    In this paper we report on a versatile hydrothermal approach developed to fabricate one-dimensional (1D) composite structures. Sulfur and selenium formed liquid and adsorbed onto microrods as droplets and subsequently reacted with metallic ion in solution to produce nanoparticles-decorated composite microrods. 1D composites including ZnO/CdS, ZnO/MnS, ZnO/CuS, ZnO/CdSe, and FeOOH/CdS were successfully made using this hydrothermal strategy and the growth mechanism was also discussed. This hydrothermal strategy is simple and green, and can be extended to the synthesis of various 1D composite structures. Moreover, the interaction between the shell nanoparticles and the one-dimensional nanomaterials were confirmed by photoluminescence investigation of ZnO/CdS.

  1. Applications of one-dimensional models in simplified inelastic analyses

    Kamal, S.A.; Chern, J.M.; Pai, D.H.

    1980-01-01

    This paper presents an approximate inelastic analysis based on geometric simplification with emphasis on its applicability, modeling, and the method of defining the loading conditions. Two problems are investigated: a one-dimensional axisymmetric model of generalized plane strain thick-walled cylinder is applied to the primary sodium inlet nozzle of the Clinch River Breeder Reactor Intermediate Heat Exchanger (CRBRP-IHX), and a finite cylindrical shell is used to simulate the branch shell forging (Y) junction. The results are then compared with the available detailed inelastic analyses under cyclic loading conditions in terms of creep and fatigue damages and inelastic ratchetting strains per the ASME Code Case N-47 requirements. In both problems, the one-dimensional simulation is able to trace the detailed stress-strain response. The quantitative comparison is good for the nozzle, but less satisfactory for the Y junction. Refinements are suggested to further improve the simulation

  2. Thermal conductivity in one-dimensional nonlinear systems

    Politi, Antonio; Giardinà, Cristian; Livi, Roberto; Vassalli, Massimo

    2000-03-01

    Thermal conducitivity of one-dimensional nonlinear systems typically diverges in the thermodynamic limit, whenever the momentum is conserved (i.e. in the absence of interactions with an external substrate). Evidence comes from detailed studies of Fermi-Pasta-Ulam and diatomic Toda chains. Here, we discuss the first example of a one-dimensional system obeying Fourier law : a chain of coupled rotators. Numerical estimates of the thermal conductivity obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase-jumps. Our conclusions are confirmed by the analysis of two variants of the rotator model.

  3. Thermoelectric properties of one-dimensional graphene antidot arrays

    Yan, Yonghong; Liang, Qi-Feng; Zhao, Hui; Wu, Chang-Qin; Li, Baowen

    2012-01-01

    We investigate the thermoelectric properties of one-dimensional (1D) graphene antidot arrays by nonequilibrium Green's function method. We show that by introducing antidots to the pristine graphene nanoribbon the thermal conductance can be reduced greatly while keeping the power factor still high, thus leading to an enhanced thermoelectric figure of merit (ZT). Our numerical results indicate that ZT values of 1D antidot graphene arrays can be up to unity, which means the 1D graphene antidot arrays may be promising for thermoelectric applications. -- Highlights: ► We study thermoelectric properties of one-dimensional (1D) graphene antidot arrays. ► Thermoelectric figure of merit (ZT) of 1D antidot arrays can exceed unity. ► ZT of 1D antidot arrays is larger than that of two-dimensional arrays.

  4. Impurity modes in the one-dimensional XXZ Heisenberg model

    Sousa, J.M.; Leite, R.V.; Landim, R.R.; Costa Filho, R.N.

    2014-01-01

    A Green's function formalism is used to calculate the energy of impurity modes associated with one and/or two magnetic impurities in the one-dimensional Heisenberg XXZ magnetic chain. The system can be tuned from the Heisenberg to the Ising model varying a parameter λ. A numerical study is performed showing two types of localized modes (s and p). The modes depend on λ and the degeneracy of the acoustic modes is broken.

  5. UNICIN - an one-dimensional computer code for reactor kinetics

    Rosa, M.A.P.; Alcantara, H.G. de; Nair, R.P.K.

    1984-01-01

    A program for the solution of the time- and space-dependent multigroup diffusion equations and the delayed-neutron precursors concentration equations in one dimensional geometries by the weighted residual method is described. The discretized equations are solved through an iterative procedure with convergence accelerated by the over-relaxation method. The system is perturbed through the variation of the nuclide concentrations in specified regions. Two feedback effects are included, namely, the temperature and the burnup. (Author) [pt

  6. The analysis of one-dimensional reactor kinetics benchmark computations

    Sidell, J.

    1975-11-01

    During March 1973 the European American Committee on Reactor Physics proposed a series of simple one-dimensional reactor kinetics problems, with the intention of comparing the relative efficiencies of the numerical methods employed in various codes, which are currently in use in many national laboratories. This report reviews the contributions submitted to this benchmark exercise and attempts to assess the relative merits and drawbacks of the various theoretical and computer methods. (author)

  7. Heat transfer in a one-dimensional mixed convection loop

    Kim, Min Joon; Lee, Yong Bum; Kim, Yong Kyun; Kim, Jong Man; Nam, Ho Yun

    1999-01-01

    Effects of non-uniform heating in the core and additional forced circulation during decay heat removal operation are studied with a simplified mixed convection loop. The heat transfer coefficient is calculated analytically and measured experimentally. The analytic solution obtained from a one-dimensional heat equation is found to agree well with the experimental results. The effects of the non-uniform heating and the forced circulation are discussed

  8. Quasi-one-dimensional intermittent flux behavior in superconducting films

    Qviller, A. J.; Yurchenko, V. V.; Galperin, Y. M.; Vestgården, J. I.; Mozhaev, Peter; Hansen, Jørn Bindslev; Johansen, T. H.

    2012-01-01

    Intermittent filamentary dynamics of the vortex matter in superconductors is found in films of YBa_{2}Cu_{3}O_{7-δ} deposited on tilted substrates. Deposition of this material on such substrates creates parallel channels of easy flux penetration when a magnetic field is applied perpendicular to the film. As the applied field is gradually increased, magneto-optical imaging reveals that flux penetrates via numerous quasi-one-dimensional jumps. The distribution of flux avalanche sizes follows a ...

  9. Variational iteration method for one dimensional nonlinear thermoelasticity

    Sweilam, N.H.; Khader, M.M.

    2007-01-01

    This paper applies the variational iteration method to solve the Cauchy problem arising in one dimensional nonlinear thermoelasticity. The advantage of this method is to overcome the difficulty of calculation of Adomian's polynomials in the Adomian's decomposition method. The numerical results of this method are compared with the exact solution of an artificial model to show the efficiency of the method. The approximate solutions show that the variational iteration method is a powerful mathematical tool for solving nonlinear problems

  10. Localization in a one-dimensional spatially correlated random potential

    Kasner, M.; Weller, W.

    1986-01-01

    The motion of an electron in a random one-dimensional spatially correlated potential is investigated. The spatial correlation is generated by a Markov chain. It is shown that the influence of the spatial correlation can be described by means of oscillating vertices usually neglected in the Berezinskii diagram technique. Correlation mainly leads to an increase of the localization length in comparison with an uncorrelated potential. However, there is a region of the parameter, where the localization decreases. (author)

  11. ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES

    Nikola Stefanović

    2007-01-01

    In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic ...

  12. Correlation functions of one-dimensional bosons at low temperature

    Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Maillet, J.M. [CNRS, ENS Lyon (France). Lab. de Physique; Slavnov, N.A. [Steklov Mathematical Institute, Moscow (Russian Federation)

    2010-12-15

    We consider the low-temperature limit of the long-distance asymptotic behavior of the finite temperature density-density correlation function in the one-dimensional Bose gas derived recently in the algebraic Bethe Ansatz framework. Our results confirm the predictions based on the Luttinger liquid and conformal field theory approaches. We also demonstrate that the amplitudes arising in this asymptotic expansion at low-temperature coincide with the amplitudes associated with the so-called critical form factors. (orig.)

  13. Negative Refraction Angular Characterization in One-Dimensional Photonic Crystals

    Lugo, Jesus Eduardo; Doti, Rafael; Faubert, Jocelyn

    2011-01-01

    Background Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity de...

  14. Majorana fermion exchange in strictly one dimensional structures

    Chiu, Ching-Kai; Vazifeh, M. M.; Franz, M.

    2014-01-01

    It is generally thought that adiabatic exchange of two identical particles is impossible in one spatial dimension. Here we describe a simple protocol that permits adiabatic exchange of two Majorana fermions in a one-dimensional topological superconductor wire. The exchange relies on the concept of "Majorana shuttle" whereby a $\\pi$ domain wall in the superconducting order parameter which hosts a pair of ancillary Majoranas delivers one zero mode across the wire while the other one tunnels in ...

  15. On a class of one-dimensional random walks

    O.J. Boxma (Onno); V.I. Lotov

    1995-01-01

    textabstractnoindent This paper studies a one-dimensional Markov chain ${X_n,n=0,1,dots$ that satisfies the recurrence relation $X_n = max(0, X_{n-1 + eta_n^{(m) )$ if $X_{n-1 =m leq a$; for $X_{n-1 > a$ it satisfies the same relation with $eta_n^{(m)$ replaced by $xi_n$. Here ${ eta_n^{(m) $ and ${

  16. Theory of the one-dimensional forest-fire model

    Paczuski, M.; Bak, P.

    1993-01-01

    Turbulent cascade processes are studied in terms of a one-dimensional forest-fire model. A hier- archy of steady-state equations for the forests and the holes between them is constructed and solved within a mean-field closure scheme. The exact hole distribution function is found to be N H (s)=4N/[s(s+1)(s+2)], where N is the number of forests

  17. Non-thermal fixed points and solitons in a one-dimensional Bose gas

    Schmidt, Maximilian; Erne, Sebastian; Nowak, Boris; Sexty, Dénes; Gasenzer, Thomas

    2012-01-01

    Single-particle momentum spectra for a dynamically evolving one-dimensional Bose gas are analysed in the semi-classical wave limit. Representing one of the simplest correlation functions, these provide information on a possible universal scaling behaviour. Motivated by the previously discovered connection between (quasi-) topological field configurations, strong wave turbulence and non-thermal fixed points of quantum field dynamics, soliton formation is studied with respect to the appearance of transient power-law spectra. A random-soliton model is developed for describing the spectra analytically, and the analogies and differences between the emerging power laws and those found in a field theory approach to strong wave turbulence are discussed. The results open a new perspective on solitary wave dynamics from the point of view of critical phenomena far from thermal equilibrium and the possibility of studying this dynamics by experiment without the need for detecting solitons in situ. (paper)

  18. Quantum logic using correlated one-dimensional quantum walks

    Lahini, Yoav; Steinbrecher, Gregory R.; Bookatz, Adam D.; Englund, Dirk

    2018-01-01

    Quantum Walks are unitary processes describing the evolution of an initially localized wavefunction on a lattice potential. The complexity of the dynamics increases significantly when several indistinguishable quantum walkers propagate on the same lattice simultaneously, as these develop non-trivial spatial correlations that depend on the particle's quantum statistics, mutual interactions, initial positions, and the lattice potential. We show that even in the simplest case of a quantum walk on a one dimensional graph, these correlations can be shaped to yield a complete set of compact quantum logic operations. We provide detailed recipes for implementing quantum logic on one-dimensional quantum walks in two general cases. For non-interacting bosons—such as photons in waveguide lattices—we find high-fidelity probabilistic quantum gates that could be integrated into linear optics quantum computation schemes. For interacting quantum-walkers on a one-dimensional lattice—a situation that has recently been demonstrated using ultra-cold atoms—we find deterministic logic operations that are universal for quantum information processing. The suggested implementation requires minimal resources and a level of control that is within reach using recently demonstrated techniques. Further work is required to address error-correction.

  19. Gravitational anomalies and one-dimensional behavior of black holes

    Majhi, Bibhas Ranjan [Indian Institute of Technology Guwahati, Department of Physics, Guwahati, Assam (India)

    2015-12-15

    It has been pointed out by Bekenstein and Mayo that the behavior of the black hole's entropy or information flow is similar to information flow through one-dimensional channel. Here I analyze the same issue with the use of gravitational anomalies. The rate of the entropy change (S) and the power (P) of the Hawking emission are calculated from the relevant components of the anomalous stress tensor under the Unruh vacuum condition. I show that the dependence of S on the power is S ∝ P{sup 1/2}, which is identical to that for the information flow in a one-dimensional system. This is established by using the (1+1)-dimensional gravitational anomalies first. Then the fact is further bolstered by considering the (1+3)-dimensional gravitational anomalies. It is found that, in the former case, the proportionality constant is exactly identical to the one-dimensional situation, known as Pendry's formula, while in the latter situation its value decreases. (orig.)

  20. Suppressing Klein tunneling in graphene using a one-dimensional array of localized scatterers.

    Walls, Jamie D; Hadad, Daniel

    2015-02-13

    Graphene's unique physical and chemical properties make it an attractive platform for use in micro- and nanoelectronic devices. However, electrostatically controlling the flow of electrons in graphene can be challenging as a result of Klein tunneling, where electrons normally incident to a one-dimensional potential barrier of height V are perfectly transmitted even as V → ∞. In this study, theoretical and numerical calculations predict that the transmission probability for an electron wave normally incident to a one-dimensional array of localized scatterers can be significantly less than unity when the electron wavelength is smaller than the spacing between scatterers. In effect, placing periodic openings throughout a potential barrier can, somewhat counterintuitively, decrease transmission in graphene. Our results suggest that electrostatic potentials with spatial variations on the order of the electron wavelength can suppress Klein tunneling and could find applications in developing graphene electronic devices.

  1. Observation of magnetoelastic effects in a quasi-one-dimensional spiral magnet

    Wang, Chong; Yu, Daiwei; Liu, Xiaoqiang; Chen, Rongyan; Du, Xinyu; Hu, Biaoyan; Wang, Lichen; Iida, Kazuki; Kamazawa, Kazuya; Wakimoto, Shuichi; Feng, Ji; Wang, Nanlin; Li, Yuan

    2017-08-01

    We present a systematic study of spin and lattice dynamics in the quasi-one-dimensional spiral magnet CuBr2, using Raman scattering in conjunction with infrared and neutron spectroscopy. Along with the development of spin correlations upon cooling, we observe a rich set of broad Raman bands at energies that correspond to phonon-dispersion energies near the one-dimensional magnetic wave vector. The low-energy bands further exhibit a distinct intensity maximum at the spiral magnetic ordering temperature. We attribute these unusual observations to two possible underlying mechanisms: (1) formation of hybrid spin-lattice excitations and/or (2) "quadrumerization" of the lattice caused by spin-singlet entanglement in competition with the spiral magnetism.

  2. Quantum magnetism in strongly interacting one-dimensional spinor Bose systems

    Salami Dehkharghani, Amin; Volosniev, A. G.; Lindgren, E. J.

    2015-01-01

    -range inter-species interactions much larger than their intra-species interactions and show that they have novel energetic and magnetic properties. In the strongly interacting regime, these systems have energies that are fractions of the basic harmonic oscillator trap quantum and have spatially separated......Strongly interacting one-dimensional quantum systems often behave in a manner that is distinctly different from their higher-dimensional counterparts. When a particle attempts to move in a one-dimensional environment it will unavoidably have to interact and 'push' other particles in order...... ground states with manifestly ferromagnetic wave functions. Furthermore, we predict excited states that have perfect antiferromagnetic ordering. This holds for both balanced and imbalanced systems, and we show that it is a generic feature as one crosses from few- to many-body systems....

  3. One-dimensional GIS-based model compared with a two-dimensional model in urban floods simulation.

    Lhomme, J; Bouvier, C; Mignot, E; Paquier, A

    2006-01-01

    A GIS-based one-dimensional flood simulation model is presented and applied to the centre of the city of Nîmes (Gard, France), for mapping flow depths or velocities in the streets network. The geometry of the one-dimensional elements is derived from the Digital Elevation Model (DEM). The flow is routed from one element to the next using the kinematic wave approximation. At the crossroads, the flows in the downstream branches are computed using a conceptual scheme. This scheme was previously designed to fit Y-shaped pipes junctions, and has been modified here to fit X-shaped crossroads. The results were compared with the results of a two-dimensional hydrodynamic model based on the full shallow water equations. The comparison shows that good agreements can be found in the steepest streets of the study zone, but differences may be important in the other streets. Some reasons that can explain the differences between the two models are given and some research possibilities are proposed.

  4. Detection of sinkholes or anomalies using full seismic wave fields : phase II.

    2016-08-01

    A new 2-D Full Waveform Inversion (FWI) software code was developed to characterize layering and anomalies beneath the ground surface using seismic testing. The software is capable of assessing the shear and compression wave velocities (Vs and Vp) fo...

  5. Time-domain full waveform inversion using the gradient preconditioning based on transmitted waves energy

    Zhang, Xiao-bo; Tan, Jun; Song, Peng; Li, Jin-shan; Xia, Dong-ming; Liu, Zhao-lun

    2017-01-01

    The gradient preconditioning approach based on seismic wave energy can effectively avoid the huge storage consumption in the gradient preconditioning algorithms based on Hessian matrices in time-domain full waveform inversion (FWI), but the accuracy

  6. Full-waveform inversion with reflected waves for 2D VTI media

    Pattnaik, Sonali; Tsvankin, Ilya; Wang, Hui; Alkhalifah, Tariq

    2016-01-01

    Full-waveform inversion in anisotropic media using reflected waves suffers from the strong non-linearity of the objective function and trade-offs between model parameters. Estimating long-wavelength model components by fixing parameter perturbations

  7. JUNO E/J/SS WAVES CALIBRATED SURVEY FULL RESOLUTION V1.0

    National Aeronautics and Space Administration — The Juno Waves calibrated full resolution survey data set includes all low rate science electric spectral densities from 50Hz to 41MHz and magnetic spectral...

  8. Reflection and transmission of normally incident full-vector X waves on planar interfaces

    Salem, Mohamed

    2011-12-23

    The reflection and transmission of full-vector X waves normally incident on planar half-spaces and slabs are studied. For this purpose, X waves are expanded in terms of weighted vector Bessel beams; this new decomposition and reconstruction method offers a more lucid and intuitive interpretation of the physical phenomena observed upon the reflection or transmission of X waves when compared to the conventional plane-wave decomposition technique. Using the Bessel beam expansion approach, we have characterized changes in the field shape and the intensity distribution of the transmitted and reflected full-vector X waves. We have also identified a novel longitudinal shift, which is observed when a full-vector X wave is transmitted through a dielectric slab under frustrated total reflection condition. The results of our studies presented here are valuable in understanding the behavior of full-vector X waves when they are utilized in practical applications in electromagnetics, optics, and photonics, such as trap and tweezer setups, optical lithography, and immaterial probing. © 2011 Optical Society of America.

  9. ICRF wave propagation and absorption in tokamak and mirror magnetic fields: a full-wave calculation

    Jaeger, E.F.; Batchelor, D.B.; Weitzner, H.; Whealton, J.H.

    1985-01-01

    Global solutions for the ion cyclotron resonant frequency (ICRF) wave fields in a straight tokamak with rotational transform and a poloidally symmetric mirror are calculated in the cold plasma limit. The component of the wave electric field parallel to vector Bis assumed zero. Symmetry in each problem allows Fourier decomposition in one ignorable coordinate, and the remaining set of two coupled, two-dimensional partial differential equations is solved by finite differencing. Energy absorption and antenna impedance are calculated using a simple collisional absorption model. When large gradients in vertical barBvertical bar along vectorB are present in either geometry, ICRF heating at the fundamental ion cyclotron resonance is observed. For the mirror, such gradients are always present. But for the tokamak, the rotational transform must be large enough that vectorB . delB greater than or equal to 0(1). For smaller transforms more typical of real tokamaks, only heating at the two-ion hybird resonance is observed. This suggests that direct resonant absorption at the fundamental ion cyclotron resonance may be possible in stellarators where vectorB . delB approx. 0(1) + 11

  10. ICRF wave propagation and absorption in tokamak and mirror magnetic fields: a full-wave calculation

    Jaeger, E.F.; Batchelor, D.B.; Weitzner, H.; Whealton, J.H.

    1986-01-01

    Global solutions for the ion cyclotron resonant frequency (ICRF) wave fields in a straight tokamak with rotational transform and in a poloidally symmetric mirror are calculated in the cold plasma limit. The component of the wave electric field parallel to B vector is assumed zero. Symmetry in each problem allows Fourier decomposition in one ignorable coordinate, and the remaining set of two coupled, two-dimensional partial differential equations is solved by finite differencing. Energy absorption and antenna impedance are calculated using a simple collisional absorption model. When large gradients in absolute value B along B vector are present in either geometry, ICRF heating at the fundamental ion cyclotron resonance is observed. For the mirror, such gradients are always present. But for the tokamak, the rotational transform must be large enough that B vector . delB greater than or equal to 0(1). For smaller transforms more typical of real tokamaks, only heating at the two-ion hybrid resonance is observed. This suggests that direct resonant absorption at the fundamental ion cyclotron resonance may be possible in stellarators where B vector . delB approx. 0(1) naturally. 13 refs., 23 figs

  11. Near equilibrium dynamics and one-dimensional spatial—temporal structures of polar active liquid crystals

    Yang Xiao-Gang; Wang Qi; Forest, M. Gregory

    2014-01-01

    We systematically explore near equilibrium, flow-driven, and flow-activity coupled dynamics of polar active liquid crystals using a continuum model. Firstly, we re-derive the hydrodynamic model to ensure the thermodynamic laws are obeyed and elastic stresses and forces are consistently accounted. We then carry out a linear stability analysis about constant steady states to study near equilibrium dynamics around the steady states, revealing long-wave instability inherent in this model system and how active parameters in the model affect the instability. We then study model predictions for one-dimensional (1D) spatial—temporal structures of active liquid crystals in a channel subject to physical boundary conditions. We discuss the model prediction in two selected regimes, one is the viscous stress dominated regime, also known as the flow-driven regime, while the other is the full regime, in which all active mechanisms are included. In the viscous stress dominated regime, the polarity vector is driven by the prescribed flow field. Dynamics depend sensitively on the physical boundary condition and the type of the driven flow field. Bulk-dominated temporal periodic states and spatially homogeneous states are possible under weak anchoring conditions while spatially inhomogeneous states exist under strong anchoring conditions. In the full model, flow-orientation interaction generates a host of planar as well as out-of-plane spatial—temporal structures related to the spontaneous flows due to the molecular self-propelled motion. These results provide contact with the recent literature on active nematic suspensions. In addition, symmetry breaking patterns emerge as the additional active viscous stress due to the polarity vector is included in the force balance. The inertia effect is found to limit the long-time survival of spatial structures to those with small wave numbers, i.e., an asymptotic coarsening to long wave structures. A rich set of mechanisms for generating

  12. Full-wave Simulations of LH Wave Propagation in Toroidal Plasma with non-Maxwellian Electron Distributions

    Valeo, E.J.; Phillips, C.K.; Bonoli, P.T.; Wright, J.C.; Brambilla, M.

    2007-01-01

    The generation of energetic tails in the electron distribution function is intrinsic to lower-hybrid (LH) heating and current drive in weakly collisional magnetically confined plasma. The effects of these deformations on the RF deposition profile have previously been examined within the ray approximation. Recently, the calculation of full-wave propagation of LH waves in a thermal plasma has been accomplished using an adaptation of the TORIC code. Here, initial results are presented from TORIC simulations of LH propagation in a toroidal plasma with non-thermal electrons. The required efficient computation of the hot plasma dielectric tensor is accomplished using a technique previously demonstrated in full-wave simulations of ICRF propagation in plasma with non-thermal ions

  13. Lateral shift in one-dimensional quasiperiodic chiral photonic crystal

    Da, Jian, E-mail: dajian521@sina.com [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Mo, Qi, E-mail: moqiyueyang@163.com [School of Software, Yunnan University, Cuihu Bai Road, Kunming City, Yunnan Province 650091 (China); Cheng, Yaokun [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Liu, Taixiang [Taishan Vocational College of Nursing, Shandong Province 271000 (China)

    2015-02-01

    We investigate the lateral shift of a one-dimensional quasiperiodic photonic crystal consisting of chiral and conventional dielectric materials. The effect of structural irregularity on lateral shift is evaluated by stationary-phase approach. Our results show that the lateral shift can be modulated by varying the structural irregularity in quasiperiodic structure. Besides, the position of peak in lateral shift spectrum stays sensitive to the chiral factor of chiral materials. In comparison with that of periodic structure, quasiperiodic structure provides an extra degree of freedom to manipulate the lateral shift.

  14. Integrability of the one dimensional Schrödinger equation

    Combot, Thierry

    2018-02-01

    We present a definition of integrability for the one-dimensional Schrödinger equation, which encompasses all known integrable systems, i.e., systems for which the spectrum can be explicitly computed. For this, we introduce the class of rigid functions, built as Liouvillian functions, but containing all solutions of rigid differential operators in the sense of Katz, and a notion of natural of boundary conditions. We then make a complete classification of rational integrable potentials. Many new integrable cases are found, some of them physically interesting.

  15. Inversion of reflection for the one-dimensional Dirac equation

    Clerk, G.L.; Davies, A.J.

    1991-01-01

    It is a general result of one-dimensional non-relativistic quantum mechanics that the coefficient of reflection (reflected flux) is the same irrespective of the direction of traversing a potential barrier, a result that is independent of the barrier shape. In this note, the authors consider the transmission coefficient instead, and derive a strong result, namely that the transmission amplitude is independent of the direction of barrier traversal. That is, the transmission amplitude has the same complex phase as well as being unchanged in magnitude by changing the barrier around. This process was called inversion of reflection. 2 refs

  16. Two-dimensional beam profiles and one-dimensional projections

    Findlay, D. J. S.; Jones, B.; Adams, D. J.

    2018-05-01

    One-dimensional projections of improved two-dimensional representations of transverse profiles of particle beams are proposed for fitting to data from harp-type monitors measuring beam profiles on particle accelerators. Composite distributions, with tails smoothly matched on to a central (inverted) parabola, are shown to give noticeably better fits than single gaussian and single parabolic distributions to data from harp-type beam profile monitors all along the proton beam transport lines to the two target stations on the ISIS Spallation Neutron Source. Some implications for inferring beam current densities on the beam axis are noted.

  17. Optical Tamm states in one-dimensional magnetophotonic structures.

    Goto, T; Dorofeenko, A V; Merzlikin, A M; Baryshev, A V; Vinogradov, A P; Inoue, M; Lisyansky, A A; Granovsky, A B

    2008-09-12

    We demonstrate the existence of a spectrally narrow localized surface state, the so-called optical Tamm state, at the interface between one-dimensional magnetophotonic and nonmagnetic photonic crystals. The state is spectrally located inside the photonic band gaps of each of the photonic crystals comprising this magnetophotonic structure. This state is associated with a sharp transmission peak through the sample and is responsible for the substantial enhancement of the Faraday rotation for the corresponding wavelength. The experimental results are in excellent agreement with the theoretical predictions.

  18. Exactly integrable analogue of a one-dimensional gravitating system

    Miller, Bruce N.; Yawn, Kenneth R.; Maier, Bill

    2005-01-01

    Exchange symmetry in acceleration partitions the configuration space of an N particle one-dimensional gravitational system (OGS) into N! equivalent cells. We take advantage of the resulting small angular separation between the forces in neighboring cells to construct a related integrable version of the system that takes the form of a central force problem in N-1 dimensions. The properties of the latter, including the construction of trajectories and possible continuum limits, are developed. Dynamical simulation is employed to compare the two models. For some initial conditions, excellent agreement is observed

  19. Acoustic and electronic properties of one-dimensional quasicrystals

    Nori, F.; Rodriguez, J.P.

    1986-01-01

    We study the acoustic and electronic properties of one-dimensional quasicrystals. Both numerical (nonperturbative) and analytical (perturbative) results are shown. The phonon and electronic spectra exhibit a self-similar hierarchy of gaps and many localized states in the gaps. We study quasiperiodic structures with any number of layers and several types of boundary conditions. We discuss the connection between our phonon model and recent experiments on quasiperiodic GaAs-AlAs superlattices. We predict the existence of many gap states localized at the surfaces

  20. Hidden symmetries in one-dimensional quantum Hamiltonians

    Curado, E.M.F.; Rego-Monteiro, M.A.; Nazareno, H.N.

    2000-11-01

    We construct a Heisenberg-like algebra for the one dimensional infinite square-well potential in quantum mechanics. The number-type and ladder operators are realized in terms of physical operators of the system as in the harmonic oscillator algebra. These physical operators are obtained with the help of variables used in a recently developed non commutative differential calculus. This square-well algebra is an example of an algebra in large class of generalized Heisenberg algebras recently constructed. This class of algebras also contains q-oscillators as a particular case. We also show here how this general algebra can address hidden symmetries present in several quantum systems. (author)

  1. Quantum quench in an atomic one-dimensional Ising chain.

    Meinert, F; Mark, M J; Kirilov, E; Lauber, K; Weinmann, P; Daley, A J; Nägerl, H-C

    2013-08-02

    We study nonequilibrium dynamics for an ensemble of tilted one-dimensional atomic Bose-Hubbard chains after a sudden quench to the vicinity of the transition point of the Ising paramagnetic to antiferromagnetic quantum phase transition. The quench results in coherent oscillations for the orientation of effective Ising spins, detected via oscillations in the number of doubly occupied lattice sites. We characterize the quench by varying the system parameters. We report significant modification of the tunneling rate induced by interactions and show clear evidence for collective effects in the oscillatory response.

  2. Chemical potential of one-dimensional simple harmonic oscillators

    Mungan, Carl E

    2009-01-01

    Expressions for the chemical potential of an Einstein solid, and of ideal Fermi and Bose gases in an external one-dimensional oscillatory trap, are calculated by two different methods and are all found to share the same functional form. These derivations are easier than traditional textbook calculations for an ideal gas in an infinite three-dimensional square well. Furthermore, the results indicate some important features of chemical potential that could promote student learning in an introductory course in statistical mechanics at the undergraduate level.

  3. Peierls' instability in a one-dimensional potentially metallic solid

    Valladares, A.A.; Cetina, E.A.; Sansores, L.E.

    1980-01-01

    The Peierls instability of one-dimensional potentially metallic lithium solid is investigated in the Hueckel and SCF approximations. In the Hueckel approximation Esub(F) is a monotonic increasing function of the displacement of every other atom of the lattice, whereas in the SCF approximation, where the filling of the bands is considered, Esub(F) shows the minimum predicted by Peierls. The energy gap (for the arrangement that minimizes Esub(F)) is 4.5 eV, indicating that this solid is an insulator. (author)

  4. One-dimensional radionuclide transport under time-varying conditions

    Gelbard, F.; Olague, N.E.; Longsine, D.E.

    1990-01-01

    This paper discusses new analytical and numerical solutions presented for one-dimensional radionuclide transport under time-varying fluid-flow conditions including radioactive decay. The analytical solution assumes that all radionuclides have identical retardation factors, and is limited to instantaneous releases. The numerical solution does not have these limitations, but is tested against the limiting case given for the analytical solution. Reasonable agreement between the two solutions was found. Examples are given for the transport of a three-member radionuclide chain transported over distances and flow rates comparable to those reported for Yucca Mountain, the proposed disposal site for high-level nuclear waste

  5. One-dimensional nonlinear inverse heat conduction technique

    Hills, R.G.; Hensel, E.C. Jr.

    1986-01-01

    The one-dimensional nonlinear problem of heat conduction is considered. A noniterative space-marching finite-difference algorithm is developed to estimate the surface temperature and heat flux from temperature measurements at subsurface locations. The trade-off between resolution and variance of the estimates of the surface conditions is discussed quantitatively. The inverse algorithm is stabilized through the use of digital filters applied recursively. The effect of the filters on the resolution and variance of the surface estimates is quantified. Results are presented which indicate that the technique is capable of handling noisy measurement data

  6. The quantum flux in quasis one-dimensional conductors

    Ventura, J.

    1989-01-01

    A method is presented which quantizes electromagnetic fluxes directly in flux space. It is based on the commutation law [φ B , φ E ] = i, where φ B is the magnetic flux, and φ E the longitudinal electric flux of a quasi one-dimensional conductor. The relevance of such a method for the description of the quantized Hall plateaus is discussed. In a second step, the polarization electric flux is introduced, together with a method for quantization of hybrid variables formed with pure electromagnetic fluxes plus electronic variables. (author) [pt

  7. Evaluation of one dimensional analytical models for vegetation canopies

    Goel, Narendra S.; Kuusk, Andres

    1992-01-01

    The SAIL model for one-dimensional homogeneous vegetation canopies has been modified to include the specular reflectance and hot spot effects. This modified model and the Nilson-Kuusk model are evaluated by comparing the reflectances given by them against those given by a radiosity-based computer model, Diana, for a set of canopies, characterized by different leaf area index (LAI) and leaf angle distribution (LAD). It is shown that for homogeneous canopies, the analytical models are generally quite accurate in the visible region, but not in the infrared region. For architecturally realistic heterogeneous canopies of the type found in nature, these models fall short. These shortcomings are quantified.

  8. Generalized entropy decay rates of one-dimensional maps

    Csordas, A.; Szepfalusy, P.

    1988-01-01

    A series of entropies, approaching the order-q Renyi's entropies when the length of orbits tends to infinity, is considered. Their scaling form is determined for chaotic one-dimensional maps. For the characteristic relaxation time a general expression is derived, and it is shown to be closely related to the eigenvalues of a generalized Frobenius-Perron operator. The case of intermittent maps is also considered, and the spectrum of relaxation time is found to reflect the phase transition at q = 1. Results of numerical experiments are also presented

  9. Entanglement entropy and complexity for one-dimensional holographic superconductors

    Kord Zangeneh, Mahdi; Ong, Yen Chin; Wang, Bin

    2017-08-01

    Holographic superconductor is an important arena for holography, as it allows concrete calculations to further understand the dictionary between bulk physics and boundary physics. An important quantity of recent interest is the holographic complexity. Conflicting claims had been made in the literature concerning the behavior of holographic complexity during phase transition. We clarify this issue by performing a numerical study on one-dimensional holographic superconductor. Our investigation shows that holographic complexity does not behave in the same way as holographic entanglement entropy. Nevertheless, the universal terms of both quantities are finite and reflect the phase transition at the same critical temperature.

  10. One-dimensional neutron imager for the Sandia Z facility.

    Fittinghoff, David N; Bower, Dan E; Hollaway, James R; Jacoby, Barry A; Weiss, Paul B; Buckles, Robert A; Sammons, Timothy J; McPherson, Leroy A; Ruiz, Carlos L; Chandler, Gordon A; Torres, José A; Leeper, Ramon J; Cooper, Gary W; Nelson, Alan J

    2008-10-01

    A multiinstitution collaboration is developing a neutron imaging system for the Sandia Z facility. The initial system design is for slit aperture imaging system capable of obtaining a one-dimensional image of a 2.45 MeV source producing 5x10(12) neutrons with a resolution of 320 microm along the axial dimension of the plasma, but the design being developed can be modified for two-dimensional imaging and imaging of DT neutrons with other resolutions. This system will allow us to understand the spatial production of neutrons in the plasmas produced at the Z facility.

  11. One-dimensional computational modeling on nuclear reactor problems

    Alves Filho, Hermes; Baptista, Josue Costa; Trindade, Luiz Fernando Santos; Heringer, Juan Diego dos Santos

    2013-01-01

    In this article, we present a computational modeling, which gives us a dynamic view of some applications of Nuclear Engineering, specifically in the power distribution and the effective multiplication factor (keff) calculations. We work with one-dimensional problems of deterministic neutron transport theory, with the linearized Boltzmann equation in the discrete ordinates (SN) formulation, independent of time, with isotropic scattering and then built a software (Simulator) for modeling computational problems used in a typical calculations. The program used in the implementation of the simulator was Matlab, version 7.0. (author)

  12. Ordering phase transition in the one-dimensional Axelrod model

    Vilone, D.; Vespignani, A.; Castellano, C.

    2002-12-01

    We study the one-dimensional behavior of a cellular automaton aimed at the description of the formation and evolution of cultural domains. The model exhibits a non-equilibrium transition between a phase with all the system sharing the same culture and a disordered phase of coexisting regions with different cultural features. Depending on the initial distribution of the disorder the transition occurs at different values of the model parameters. This phenomenology is qualitatively captured by a mean-field approach, which maps the dynamics into a multi-species reaction-diffusion problem.

  13. One-Dimensional Rydberg Gas in a Magnetoelectric Trap

    Mayle, Michael; Hezel, Bernd; Lesanovsky, Igor; Schmelcher, Peter

    2007-01-01

    We study the quantum properties of Rydberg atoms in a magnetic Ioffe-Pritchard trap which is superimposed by a homogeneous electric field. Trapped Rydberg atoms can be created in long-lived electronic states exhibiting a permanent electric dipole moment of several hundred Debye. The resulting dipole-dipole interaction in conjunction with the radial confinement is demonstrated to give rise to an effectively one-dimensional ultracold Rydberg gas with a macroscopic interparticle distance. We derive analytical expressions for the electric dipole moment and the required linear density of Rydberg atoms

  14. One-dimensional inverse problems of mathematical physics

    Lavrent'ev, M M; Yakhno, V G; Schulenberger, J R

    1986-01-01

    This monograph deals with the inverse problems of determining a variable coefficient and right side for hyperbolic and parabolic equations on the basis of known solutions at fixed points of space for all times. The problems are one-dimensional in nature since the desired coefficient of the equation is a function of only one coordinate, while the desired right side is a function only of time. The authors use methods based on the spectral theory of ordinary differential operators of second order and also methods which make it possible to reduce the investigation of the inverse problems to the in

  15. Lattice relaxation theory of localized excitations in quasi-one-dimensional systems

    Wang Chuilin; Su Zhaobin; Yu Lu.

    1993-04-01

    The lattice relaxation theory developed earlier by Su and Yu for solitons and polarons in conducting polymers is applied to systems with both electron-phonon and electron-electron interactions, described by a single band Peierls-Hubbard model. The localized excitations in the competing bond-order-wave (BOW), charge-density-wave (CDW) and spin-density-wave (SDW) systems show interesting new features in their dynamics. In particular, a non-monotonic dependence of the relaxation rate on the coupling strength is predicted from the theory. The possible connection of this effect with photo-luminescence experiments is discussed. Similar phenomena may occur in other quasi-one-dimensional systems as well. (author). 21 refs, 4 figs

  16. Exact solutions of the one-dimensional generalized modified complex Ginzburg-Landau equation

    Yomba, Emmanuel; Kofane, Timoleon Crepin

    2003-01-01

    The one-dimensional (1D) generalized modified complex Ginzburg-Landau (MCGL) equation for the traveling wave systems is analytically studied. Exact solutions of this equation are obtained using a method which combines the Painleve test for integrability in the formalism of Weiss-Tabor-Carnevale and Hirota technique of bilinearization. We show that pulses, fronts, periodic unbounded waves, sources, sinks and solution as collision between two fronts are the important coherent structures that organize much of the dynamical properties of these traveling wave systems. The degeneracies of the 1D generalized MCGL equation are examined as well as several of their solutions. These degeneracies include two important equations: the 1D generalized modified Schroedinger equation and the 1D generalized real modified Ginzburg-Landau equation. We obtain that the one parameter family of traveling localized source solutions called 'Nozaki-Bekki holes' become a subfamily of the dark soliton solutions in the 1D generalized modified Schroedinger limit

  17. Pelamis wave energy converter. Verification of full-scale control using a 7th scale model

    NONE

    2005-07-01

    The Pelamis Wave Energy Converter is a new concept for converting wave energy for several applications including generation of electric power. The machine is flexibly moored and swings to meet the water waves head-on. The system is semi-submerged and consists of cylindrical sections linked by hinges. The mechanical operation is described in outline. A one-seventh scale model was built and tested and the outcome was sufficiently successful to warrant the building of a full-scale prototype. In addition, a one-twentieth scale model was built and has contributed much to the research programme. The work is supported financially by the DTI.

  18. Nouvelles méthodes d'identification des fractures par diagraphie acoustique en full wave form New Methods of Identifying Fractures by Full Wave Form Acoustic Logging

    Denis A.

    2006-11-01

    Full Text Available Les outils acoustiques de dernière génération permettent maintenant d'enregistrer l'ensemble des ondes générées par une source acoustique à l'intérieur d'une géométrie cylindrique telle qu'un puits de sondage. Le train d'onde qu'il est alors possible d'analyser se compose successivement de trois composantes majeures (l'onde de compression, de cisaillement et de Stoneley dont nous avons une représentation pour chaque position de la sonde à l'intérieur du puits. Nous présentons, dans ce texte, trois méthodes originales et rapides (calculs possibles sur le site même pour identifier, à partir du traitement de l'onde de Stoneley, les fractures ouvertes recoupées par un forage. Nous donnons, dans un premier temps, nos motivations pour le choix unique du traitement de l'onde de Stoneley pour, dans un deuxième temps, exposer les trois méthodes développées et montrer pour chacune d'entre elles une application pratique. Interest in recognizing and identifying fractures in a coherent formation for the petroleum, geothermal and storage (oil and gas, wastes sectors has led to the development of indirect prospection methods inside boreholes such as acoustic logging. The latest acoustic tools are capable of recording all waves generated by an acoustic logging tool inside a cyclindrical geometry such as a borehole. The wavetrain that can then be analyzed is successively made up of three major components (the P compression wave, the S shear wave and the Stoneley wave for which we have a representation for each position of the logging tool in the borehole. An example of a recording is shown in Fig. 1. Because of its specific features (high amplitudes, low frequency, high signal-to-noise ratio, the Stoneley wave is recognized to be a good indicator of open fractures. Therefore, we use simple digital processing to quantify the influence of fracturing on the propagation of the Stoneley wave. Three methods stemming from the digital processing of

  19. Hydrogen peroxide stabilization in one-dimensional flow columns

    Schmidt, Jeremy T.; Ahmad, Mushtaque; Teel, Amy L.; Watts, Richard J.

    2011-09-01

    Rapid hydrogen peroxide decomposition is the primary limitation of catalyzed H 2O 2 propagations in situ chemical oxidation (CHP ISCO) remediation of the subsurface. Two stabilizers of hydrogen peroxide, citrate and phytate, were investigated for their effectiveness in one-dimensional columns of iron oxide-coated and manganese oxide-coated sand. Hydrogen peroxide (5%) with and without 25 mM citrate or phytate was applied to the columns and samples were collected at 8 ports spaced 13 cm apart. Citrate was not an effective stabilizer for hydrogen peroxide in iron-coated sand; however, phytate was highly effective, increasing hydrogen peroxide residuals two orders of magnitude over unstabilized hydrogen peroxide. Both citrate and phytate were effective stabilizers for manganese-coated sand, increasing hydrogen peroxide residuals by four-fold over unstabilized hydrogen peroxide. Phytate and citrate did not degrade and were not retarded in the sand columns; furthermore, the addition of the stabilizers increased column flow rates relative to unstabilized columns. These results demonstrate that citrate and phytate are effective stabilizers of hydrogen peroxide under the dynamic conditions of one-dimensional columns, and suggest that citrate and phytate can be added to hydrogen peroxide before injection to the subsurface as an effective means for increasing the radius of influence of CHP ISCO.

  20. Stopping time of a one-dimensional bounded quantum walk

    Luo Hao; Zhang Peng; Zhan Xiang; Xue Peng

    2016-01-01

    The stopping time of a one-dimensional bounded classical random walk (RW) is defined as the number of steps taken by a random walker to arrive at a fixed boundary for the first time. A quantum walk (QW) is a non-trivial generalization of RW, and has attracted a great deal of interest from researchers working in quantum physics and quantum information. In this paper, we develop a method to calculate the stopping time for a one-dimensional QW. Using our method, we further compare the properties of stopping time for QW and RW. We find that the mean value of the stopping time is the same for both of these problems. However, for short times, the probability for a walker performing a QW to arrive at the boundary is larger than that for a RW. This means that, although the mean stopping time of a quantum and classical walker are the same, the quantum walker has a greater probability of arriving at the boundary earlier than the classical walker. (paper)

  1. Bjorken flow in one-dimensional relativistic magnetohydrodynamics with magnetization

    Pu, Shi; Roy, Victor; Rezzolla, Luciano; Rischke, Dirk H.

    2016-04-01

    We study the one-dimensional, longitudinally boost-invariant motion of an ideal fluid with infinite conductivity in the presence of a transverse magnetic field, i.e., in the ideal transverse magnetohydrodynamical limit. In an extension of our previous work Roy et al., [Phys. Lett. B 750, 45 (2015)], we consider the fluid to have a nonzero magnetization. First, we assume a constant magnetic susceptibility χm and consider an ultrarelativistic ideal gas equation of state. For a paramagnetic fluid (i.e., with χm>0 ), the decay of the energy density slows down since the fluid gains energy from the magnetic field. For a diamagnetic fluid (i.e., with χmlaw ˜τ-a, two distinct solutions can be found depending on the values of a and χm. Finally, we also solve the ideal magnetohydrodynamical equations for one-dimensional Bjorken flow with a temperature-dependent magnetic susceptibility and a realistic equation of state given by lattice-QCD data. We find that the temperature and energy density decay more slowly because of the nonvanishing magnetization. For values of the magnetic field typical for heavy-ion collisions, this effect is, however, rather small. It is only for magnetic fields about an order of magnitude larger than expected for heavy-ion collisions that the system is substantially reheated and the lifetime of the quark phase might be extended.

  2. Hamiltonian field description of the one-dimensional Poisson-Vlasov equations

    Morrison, P.J.

    1981-07-01

    The one-dimensional Poisson-Vlasov equations are cast into Hamiltonian form. A Poisson Bracket in terms of the phase space density, as sole dynamical variable, is presented. This Poisson bracket is not of the usual form, but possesses the commutator properties of antisymmetry, bilinearity, and nonassociativity by virtue of the Jacobi requirement. Clebsch potentials are seen to yield a conventional (canonical) formulation. This formulation is discretized by expansion in terms of an arbitrary complete set of basis functions. In particular, a wave field representation is obtained

  3. Time-dependent Bragg diffraction and short-pulse reflection by one-dimensional photonic crystals

    André, Jean-Michel; Jonnard, Philippe

    2015-01-01

    The time-dependence of the Bragg diffraction by one-dimensional photonic crystals and its influence on the short pulse reflection are studied in the framework of the coupled-wave theory. The indicial response of the photonic crystal is calculated and it appears that it presents a time-delay effect with a transient time conditioned by the extinction length. A numerical simulation is presented for a Bragg mirror in the x-ray domain and a pulse envelope modelled by a sine-squared shape. The potential consequences of the time-delay effect in time-dependent optics of short-pulses are emphasized. (paper)

  4. Photonic band structures in one-dimensional photonic crystals containing Dirac materials

    Wang, Lin; Wang, Li-Gang

    2015-01-01

    We have investigated the band structures of one-dimensional photonic crystals (1DPCs) composed of Dirac materials and ordinary dielectric media. It is found that there exist an omnidirectional passing band and a kind of special band, which result from the interaction of the evanescent and propagating waves. Due to the interface effect and strong dispersion, the electromagnetic fields inside the special bands are strongly enhanced. It is also shown that the properties of these bands are invariant upon the lattice constant but sensitive to the resonant conditions

  5. Observation of large photonic band gaps and defect modes in one-dimensional networked waveguides

    Mir, A; Vasseur, J O; Djafari-Rouhani, B; Fettouhi, N; Boudouti, E H E; Dobrzynski, L; Zemmouri, J

    2003-01-01

    The photonic band structures and transmission spectra of serial loop structures (SLSs), made of loops pasted together with segments of finite length, are investigated experimentally and theoretically. These monomode structures, composed of one-dimensional dielectric materials, may exhibit large stop bands where the propagation of electromagnetic waves is forbidden. The width of these band gaps depends on the geometrical and compositional parameters of the structure and may be drastically increased in a tandem geometry made up of several successive SLSs which differ in their physical characteristics. These SLSs may have potential applications as ultrawide-band filters.

  6. Some optical properties of one dimensional annular photonic crystal with plasma frequency

    Pandeya, G. N.; Thapa, Khem B.

    2018-05-01

    This paper presents the reflection bands, photonic band gaps, of the one-dimensional annul photonic crystal (APC) containing double negative (DNG) metamaterials and air. The proposed annular structure consists of the alternate layers of dispersive DNG material and air immersed in free space. The reflectance properties of the APC by employing the transfer matrix method (TMM) in the cylindrical waves for TE polarization is studied theoretically. In addition of this, we have also studied the effect of plasma frequency on the reflection behavior of the considered annular structure.

  7. Wideband absorption in one dimensional photonic crystal with graphene-based hyperbolic metamaterials

    Kang, Yongqiang; Liu, Hongmei

    2018-02-01

    A broadband absorber which was proposed by one dimensional photonic crystal (1DPC) containing graphene-based hyperbolic metamaterials (GHMM) is theoretically investigated. For TM mode, it was demonstrated to absorb roughly 90% of all available electromagnetic waves at a 14 THz absorption bandwidth at normal incidence. The absorption bandwidth was affected by Fermi energy and thickness of dielectric layer. When the incident angle was increased, the absorption value decreased, and the absorption band had a gradual blue shift. These findings have potential applications for designing broadband optoelectronic devices at mid-infrared and THz frequency range.

  8. One-Dimensional Fokker-Planck Equation with Quadratically Nonlinear Quasilocal Drift

    Shapovalov, A. V.

    2018-04-01

    The Fokker-Planck equation in one-dimensional spacetime with quadratically nonlinear nonlocal drift in the quasilocal approximation is reduced with the help of scaling of the coordinates and time to a partial differential equation with a third derivative in the spatial variable. Determining equations for the symmetries of the reduced equation are derived and the Lie symmetries are found. A group invariant solution having the form of a traveling wave is found. Within the framework of Adomian's iterative method, the first iterations of an approximate solution of the Cauchy problem are obtained. Two illustrative examples of exact solutions are found.

  9. Resonant photon tunneling via surface plasmon polaritons through one-dimensional metal-dielectric metamaterials.

    Tomita, Satoshi; Yokoyama, Takashi; Yanagi, Hisao; Wood, Ben; Pendry, John B; Fujii, Minoru; Hayashi, Shinji

    2008-06-23

    We report resonant photon tunneling (RPT) through one-dimensional metamaterials consisting of alternating layers of metal and dielectric. RPT via a surface plasmon polariton state permits evanescent light waves with large wavenumbers to be conveyed through the metamaterial. This is the mechanism for sub-wavelength imaging recently demonstrated with a super-lens. Furthermore, we find that the RPT peak is shifted from the reflectance dip with increasing the number of Al layers, indicating that the shift is caused by the losses in the RPT.

  10. Current Mode Full-Wave Rectifier Based on a Single MZC-CDTA

    Neeta Pandey

    2013-01-01

    Full Text Available This paper presents a current mode full-wave rectifier based on single modified Z copy current difference transconductance amplifier (MZC-CDTA and two switches. The circuit is simple and is suitable for IC implementation. The functionality of the circuit is verified with SPICE simulation using 0.35 μm TSMC CMOS technology parameters.

  11. A Novel Current-Mode Full-Wave Rectifier Based on One CDTA and Two Diodes

    F. Khateb

    2010-09-01

    Full Text Available Precision rectifiers are important building blocks for analog signal processing. The traditional approach based on diodes and operational amplifiers (OpAmps exhibits undesirable effects caused by limited OpAmp slew rate and diode commutations. In the paper, a full-wave rectifier based on one CDTA and two Schottky diodes is presented. The PSpice simulation results are included.

  12. One-way mode transmission in one-dimensional phononic crystal plates

    Zhu, Xuefeng; Zou, Xinye; Liang, Bin; Cheng, Jianchun

    2010-12-01

    We investigate theoretically the band structures of one-dimensional phononic crystal (PC) plates with both antisymmetric and symmetric structures, and show how unidirectional transmission behavior can be obtained for either antisymmetric waves (A modes) or symmetric waves (S modes) by exploiting mode conversion and selection in the linear plate systems. The theoretical approach is illustrated for one PC plate example where unidirectional transmission behavior is obtained in certain frequency bands. Employing harmonic frequency analysis, we numerically demonstrate the one-way mode transmission for the PC plate with finite superlattice by calculating the steady-state displacement fields under A modes source (or S modes source) in forward and backward direction, respectively. The results show that the incident waves from A modes source (or S modes source) are transformed into S modes waves (or A modes waves) after passing through the superlattice in the forward direction and the Lamb wave rejections in the backward direction are striking with a power extinction ratio of more than 1000. The present structure can be easily extended to two-dimensional PC plate and efficiently encourage practical studies of experimental realization which is believed to have much significance for one-way Lamb wave mode transmission.

  13. ICRF Mode Conversion Studies with Phase Contrast Imaging and Comparisons with Full-Wave Simulations

    Tsujii, N.; Bonoli, P. T.; Lin, Y.; Wright, J. C.; Wukitch, S. J.; Porkolab, M.; Jaeger, E. F.; Harvey, R. W.

    2011-01-01

    Waves in the ion cyclotron range of frequencies (ICRF) are widely used to heat toka-mak plasmas. In a multi-ion-species plasma, the FW converts to ion cyclotron waves (ICW) and ion Bernstein waves (IBW) around the ion-ion hybrid resonance (mode conversion). The mode converted wave is of interest as an actuator to optimise plasma performance through flow drive and current drive. Numerical simulations are essential to describe these processes accurately, and it is important that these simulation codes be validated. On Alcator C-Mod, direct measurements of the mode converted waves have been performed using Phase Contrast Imaging (PCI), which measures the line-integrated electron density fluctuations. The results were compared to full-wave simulations AORSA and TORIC. AORSA is coupled to a Fokker-Planck code CQL3D for self-consistent simulation of the wave electric field and the minority distribution function. The simulation results are compared to PCI measurements using synthetic diagnostic. The experiments were performed in D-H and D- 3 He plasmas over a wide range of ion species concentrations. The simulations agreed well with the measurements in the strong absorption regime. However, the measured fluctuation intensity was smaller by 1-2 orders of magnitudes in the weakly abosorbing regime, and a realistic description of the plasma edge including dissipation and antenna geometry may be required in these cases.

  14. Resonant scattering induced thermopower in one-dimensional disordered systems

    Müller, Daniel; Smit, Wilbert J.; Sigrist, Manfred

    2015-05-01

    This study analyzes thermoelectric properties of a one-dimensional random conductor which shows localization effects and simultaneously includes resonant scatterers yielding sharp conductance resonances. These sharp features give rise to a distinct behavior of the Seebeck coefficient in finite systems and incorporate the degree of localization as a means to enhance thermoelectric performance, in principle. The model for noninteracting electrons is discussed within the Landauer-Büttiker formalism such that analytical treatment is possible for a wide range of properties, if a special averaging scheme is applied. The approximations in the averaging procedure are tested with numerical evaluations showing good qualitative agreement, with some limited quantitative disagreement. The validity of low-temperature Mott's formula is determined and a good approximation is developed for the intermediate temperature range. In both regimes the intricate interplay between Anderson localization due to disorder and conductance resonances of the disorder potential is analyzed.

  15. One-dimensional reactor kinetics model for RETRAN

    Gose, G.C.; Peterson, C.E.; Ellis, N.L.; McClure, J.A.

    1981-01-01

    Previous versions of RETRAN have had only a point kinetics model to describe the reactor core behavior during thermal-hydraulic transients. The principal assumption in deriving the point kinetics model is that the neutron flux may be separated into a time-dependent amplitude funtion and a time-independent shape function. Certain types of transients cannot be correctly analyzed under this assumption, since proper definitions for core average quantities such as reactivity or lifetime include the inner product of the adjoint flux with the perturbed flux. A one-dimensional neutronics model has been included in a preliminary version of RETRAN-02. The ability to account for flux shape changes will permit an improved representation of the thermal and hydraulic feedback effects. This paper describes the neutronics model and discusses some of the analyses

  16. One-dimensional Ising model with multispin interactions

    Turban, Loïc

    2016-09-01

    We study the spin-1/2 Ising chain with multispin interactions K involving the product of m successive spins, for general values of m. Using a change of spin variables the zero-field partition function of a finite chain is obtained for free and periodic boundary conditions and we calculate the two-spin correlation function. When placed in an external field H the system is shown to be self-dual. Using another change of spin variables the one-dimensional Ising model with multispin interactions in a field is mapped onto a zero-field rectangular Ising model with first-neighbour interactions K and H. The 2D system, with size m × N/m, has the topology of a cylinder with helical BC. In the thermodynamic limit N/m\\to ∞ , m\\to ∞ , a 2D critical singularity develops on the self-duality line, \\sinh 2K\\sinh 2H=1.

  17. One-dimensional thermodynamical model for poling of ferroelectric ceramics

    Bassiouny, E.

    1990-11-01

    In this work, we use a model developed to deduce a one-dimensional model for the description of the poling of ferroelectric ceramics. This is built within the scheme of the thermodynamical theory of internal variables. The model produces both plastic and electric hysteresis effects in the form of ''plasticity'', i.e., rate-independent evolution equations for the plastic strain, and the residual electric polarization and both mechanical and electric hardenings. The influence of stresses on ferroelectric hysteresis loops through piezoelectricity and electrostriction is a natural outcome of this model. Some simple experimental methods for the determination of the material coefficients of the considered ceramics are suggested. (author). 21 refs, 3 figs

  18. Quasi one dimensional transport in individual electrospun composite nanofibers

    Avnon, A., E-mail: avnon@phys.fu-berlin.de; Datsyuk, V.; Trotsenko, S. [Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Wang, B.; Zhou, S. [Research Center of Microperipheric Technologies, Technische Universität Berlin, TiB4/2-1, Gustav-Meyer-Allee 25, 13355 Berlin (Germany); Grabbert, N.; Ngo, H.-D. [Microsystem Engineering (FB I), University of Applied Sciences, Wilhelminenhofstr. 74 (C 525), 12459 Berlin (Germany)

    2014-01-15

    We present results of transport measurements of individual suspended electrospun nanofibers Poly(methyl methacrylate)-multiwalled carbon nanotubes. The nanofiber is comprised of highly aligned consecutive multiwalled carbon nanotubes. We have confirmed that at the range temperature from room temperature down to ∼60 K, the conductance behaves as power-law of temperature with an exponent of α ∼ 2.9−10.2. The current also behaves as power law of voltage with an exponent of β ∼ 2.3−8.6. The power-law behavior is a footprint for one dimensional transport. The possible models of this confined system are discussed. Using the model of Luttinger liquid states in series, we calculated the exponent for tunneling into the bulk of a single multiwalled carbon nanotube α{sub bulk} ∼ 0.06 which agrees with theoretical predictions.

  19. One-dimensional disk model simulation for klystron design

    Yonezawa, H.; Okazaki, Y.

    1984-05-01

    In 1982, one of the authors (Okazaki), of Toshiba Corporation, wrote a one-dimensional, rigid-disk model computer program to serve as a reliable design tool for the 150 MW klystron development project. This is an introductory note for the users of this program. While reviewing the so-called disk programs presently available, hypotheses such as gridded interaction gaps, a linear relation between phase and position, and so on, were found. These hypotheses bring serious limitations and uncertainties into the computational results. JPNDISK was developed to eliminate these defects, to follow the equations of motion as rigorously as possible, and to obtain self-consistent solutions for the gap voltages and the electron motion. Although some inaccuracy may be present in the relativistic region, JPNDISK, in its present form, seems a most suitable tool for klystron design; it is both easy and inexpensive to use

  20. Probing the exchange statistics of one-dimensional anyon models

    Greschner, Sebastian; Cardarelli, Lorenzo; Santos, Luis

    2018-05-01

    We propose feasible scenarios for revealing the modified exchange statistics in one-dimensional anyon models in optical lattices based on an extension of the multicolor lattice-depth modulation scheme introduced in [Phys. Rev. A 94, 023615 (2016), 10.1103/PhysRevA.94.023615]. We show that the fast modulation of a two-component fermionic lattice gas in the presence a magnetic field gradient, in combination with additional resonant microwave fields, allows for the quantum simulation of hardcore anyon models with periodic boundary conditions. Such a semisynthetic ring setup allows for realizing an interferometric arrangement sensitive to the anyonic statistics. Moreover, we show as well that simple expansion experiments may reveal the formation of anomalously bound pairs resulting from the anyonic exchange.

  1. One-dimensional reduction of viscous jets. II. Applications

    Pitrou, Cyril

    2018-04-01

    In a companion paper [Phys. Rev. E 97, 043115 (2018), 10.1103/PhysRevE.97.043115], a formalism allowing to describe viscous fibers as one-dimensional objects was developed. We apply it to the special case of a viscous fluid torus. This allows to highlight the differences with the basic viscous string model and with its viscous rod model extension. In particular, an elliptic deformation of the torus section appears because of surface tension effects, and this cannot be described by viscous string nor viscous rod models. Furthermore, we study the Rayleigh-Plateau instability for periodic deformations around the perfect torus, and we show that the instability is not sufficient to lead to the torus breakup in several droplets before it collapses to a single spherical drop. Conversely, a rotating torus is dynamically attracted toward a stationary solution, around which the instability can develop freely and split the torus in multiple droplets.

  2. One-Dimensional Time to Explosion (Thermal Sensitivity) of ANPZ

    Hsu, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hust, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McClelland, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gresshoff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-11-12

    Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 C) and the violence from thermal explosion may cause a significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to explosion, threshold thermal explosion temperature, and determine kinetic parameters of energetic materials. Samples of different configurations (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. This report summarizes the recent ODTX experimental data and modeling results for 2,6-diamino-3,5-dintropyrazine (ANPZ).

  3. The transmission probability method in one-dimensional cylindrical geometry

    Rubin, I.E.

    1983-01-01

    The collision probability method widely used in solving the problems of neutron transpopt in a reactor cell is reliable for simple cells with small number of zones. The increase of the number of zones and also taking into account the anisotropy of scattering greatly increase the scope of calculations. In order to reduce the time of calculation the transmission probability method is suggested to be used for flux calculation in one-dimensional cylindrical geometry taking into account the scattering anisotropy. The efficiency of the suggested method is verified using the one-group calculations for cylindrical cells. The use of the transmission probability method allows to present completely angular and spatial dependences is neutrons distributions without the increase in the scope of calculations. The method is especially effective in solving the multi-group problems

  4. Piezoelectric transducer vibrations in a one-dimensional approximation

    Hilke, H J

    1973-01-01

    The theory of piezoelectric transducer vibrations, which may be treated as one-dimensional, is developed in detail for thin discs vibrating in a pure thickness extensional mode. An effort has been made to obtain relations of general validity, which include losses, and which are in a simple explicit form convenient for practical calculations. The behaviour of transducers is discussed with special attention to their characteristics at the two fundamental frequencies, the so-called parallel and series resonances. Several peculiarities occur when transducers are coupled to media with considerably different acoustic impedances. These peculiarities are discussed and illustrated by numerical results for quartz and PZT 4 piezoelectric discs radiating into water, air and liquid hydrogen. The application of the theory to different types of vibrations is briefly illustrated for thin bars vibrating longitudinally. Short discussions are included on compound transducer systems, and on the properties of thin discs as receiv...

  5. Experiment and simulation on one-dimensional plasma photonic crystals

    Zhang, Lin; Ouyang, Ji-Ting

    2014-01-01

    The transmission characteristics of microwaves passing through one-dimensional plasma photonic crystals (PPCs) have been investigated by experiment and simulation. The PPCs were formed by a series of discharge tubes filled with argon at 5 Torr that the plasma density in tubes can be varied by adjusting the discharge current. The transmittance of X-band microwaves through the crystal structure was measured under different discharge currents and geometrical parameters. The finite-different time-domain method was employed to analyze the detailed properties of the microwaves propagation. The results show that there exist bandgaps when the plasma is turned on. The properties of bandgaps depend on the plasma density and the geometrical parameters of the PPCs structure. The PPCs can perform as dynamical band-stop filter to control the transmission of microwaves within a wide frequency range

  6. Analytical models of optical response in one-dimensional semiconductors

    Pedersen, Thomas Garm

    2015-01-01

    The quantum mechanical description of the optical properties of crystalline materials typically requires extensive numerical computation. Including excitonic and non-perturbative field effects adds to the complexity. In one dimension, however, the analysis simplifies and optical spectra can be computed exactly. In this paper, we apply the Wannier exciton formalism to derive analytical expressions for the optical response in four cases of increasing complexity. Thus, we start from free carriers and, in turn, switch on electrostatic fields and electron–hole attraction and, finally, analyze the combined influence of these effects. In addition, the optical response of impurity-localized excitons is discussed. - Highlights: • Optical response of one-dimensional semiconductors including excitons. • Analytical model of excitonic Franz–Keldysh effect. • Computation of optical response of impurity-localized excitons

  7. SUSY-hierarchy of one-dimensional reflectionless potentials

    Maydanyuk, Sergei P

    2004-01-01

    A class of one-dimensional reflectionless potentials, an absolute transparency of which is concerned with their belonging to one SUSY-hierarchy with a constant potential, is studied. An approach for determination of a general form of the reflectionless potential on the basis of construction of such a hierarchy by the recurrent method is proposed. A general form of interdependence between superpotentials with neighboring numbers of this hierarchy, opening a possibility to find new reflectionless potentials, have a simple analytical view and are expressed through finite number of elementary functions (unlike some reflectionless potentials, which are constructed on the basis of soliton solutions or are shape invariant in one or many steps with involving scaling of parameters, and are expressed through series), is obtained. An analysis of absolute transparency existence for the potential which has the inverse power dependence on space coordinate (and here tunneling is possible), i.e. which has the form $V(x) = \\p...

  8. A Reduced Order, One Dimensional Model of Joint Response

    DOHNER,JEFFREY L.

    2000-11-06

    As a joint is loaded, the tangent stiffness of the joint reduces due to slip at interfaces. This stiffness reduction continues until the direction of the applied load is reversed or the total interface slips. Total interface slippage in joints is called macro-slip. For joints not undergoing macro-slip, when load reversal occurs the tangent stiffness immediately rebounds to its maximum value. This occurs due to stiction effects at the interface. Thus, for periodic loads, a softening and rebound hardening cycle is produced which defines a hysteretic, energy absorbing trajectory. For many jointed sub-structures, this hysteretic trajectory can be approximated using simple polynomial representations. This allows for complex joint substructures to be represented using simple non-linear models. In this paper a simple one dimensional model is discussed.

  9. Capillary condensation in one-dimensional irregular confinement.

    Handford, Thomas P; Pérez-Reche, Francisco J; Taraskin, Sergei N

    2013-07-01

    A lattice-gas model with heterogeneity is developed for the description of fluid condensation in finite sized one-dimensional pores of arbitrary shape. Mapping to the random-field Ising model allows an exact solution of the model to be obtained at zero-temperature, reproducing the experimentally observed dependence of the amount of fluid adsorbed in the pore on external pressure. It is demonstrated that the disorder controls the sorption for long pores and can result in H2-type hysteresis. Finite-temperature Metropolis dynamics simulations support analytical findings in the limit of low temperatures. The proposed framework is viewed as a fundamental building block of the theory of capillary condensation necessary for reliable structural analysis of complex porous media from adsorption-desorption data.

  10. Topologically protected states in one-dimensional systems

    Fefferman, C L; Weinstein, M I

    2017-01-01

    The authors study a class of periodic Schrödinger operators, which in distinguished cases can be proved to have linear band-crossings or "Dirac points". They then show that the introduction of an "edge", via adiabatic modulation of these periodic potentials by a domain wall, results in the bifurcation of spatially localized "edge states". These bound states are associated with the topologically protected zero-energy mode of an asymptotic one-dimensional Dirac operator. The authors' model captures many aspects of the phenomenon of topologically protected edge states for two-dimensional bulk structures such as the honeycomb structure of graphene. The states the authors construct can be realized as highly robust TM-electromagnetic modes for a class of photonic waveguides with a phase-defect.

  11. Interacting Fermi gases in disordered one-dimensional lattices

    Xianlong, Gao; Polini, M.; Tosi, M. P.; Tanatar, B.

    2006-01-01

    Interacting two-component Fermi gases loaded in a one-dimensional (1D) lattice and subject to harmonic trapping exhibit intriguing compound phases in which fluid regions coexist with local Mott-insulator and/or band-insulator regions. Motivated by experiments on cold atoms inside disordered optical lattices, we present a theoretical study of the effects of a random potential on these ground-state phases. Within a density-functional scheme we show that disorder has two main effects: (i) it destroys the local insulating regions if it is sufficiently strong compared with the on-site atom-atom repulsion, and (ii) it induces an anomaly in the compressibility at low density from quenching of percolation

  12. A one-dimensional ice structure built from pentagons

    Carrasco, Javier; Michaelides, Angelos

    2010-03-01

    Heterogeneous nucleation of water plays a key role in fields as diverse as atmospheric chemistry, astrophysics, and biology. Ice nucleation on metal surfaces offers an opportunity to watch this process unfold, providing a molecular-scale description at a well-defined, planar interface. We discuss a density-functional theory study on a metal surface specifically designed to understand such phenomena. Together with our colleges at the University of Liverpool, we found that the nanometer wide water-ice chains experimentally observed to nucleate and grow on Cu(110) are built from a face sharing arrangement of water pentagons [1]. The novel one-dimensional pentagon structure maximizes the water-metal bonding whilst simultaneously maintaining a strong hydrogen bonding network. These results reveal an unanticipated structural adaptability of water-ice films, demonstrating that the presence of the substrate can be sufficient to favor non-conventional structural units. [4pt] [1] J. Carrasco et al., Nature Mater. 8, 427 (2009).

  13. Hidden magnetism in periodically modulated one dimensional dipolar fermions

    Fazzini, S.; Montorsi, A.; Roncaglia, M.; Barbiero, L.

    2017-12-01

    The experimental realization of time-dependent ultracold lattice systems has paved the way towards the implementation of new Hubbard-like Hamiltonians. We show that in a one-dimensional two-components lattice dipolar Fermi gas the competition between long range repulsion and correlated hopping induced by periodically modulated on-site interaction allows for the formation of hidden magnetic phases, with degenerate protected edge modes. The magnetism, characterized solely by string-like nonlocal order parameters, manifests in the charge and/or in the spin degrees of freedom. Such behavior is enlighten by employing Luttinger liquid theory and numerical methods. The range of parameters for which hidden magnetism is present can be reached by means of the currently available experimental setups and probes.

  14. Relativistic collective diffusion in one-dimensional systems

    Lin, Gui-Wu; Lam, Yu-Yiu; Zheng, Dong-Qin; Zhong, Wei-Rong

    2018-05-01

    The relativistic collective diffusion in one-dimensional molecular system is investigated through nonequilibrium molecular dynamics with Monte Carlo methods. We have proposed the relationship among the speed, the temperature, the density distribution and the collective diffusion coefficient of particles in a relativistic moving system. It is found that the relativistic speed of the system has no effect on the temperature, but the collective diffusion coefficient decreases to zero as the velocity of the system approaches to the speed of light. The collective diffusion coefficient is modified as D‧ = D(1 ‑w2 c2 )3 2 for satisfying the relativistic circumstances. The present results may contribute to the understanding of the behavior of the particles transport diffusion in a high speed system, as well as enlighten the study of biological metabolism at relativistic high speed situation.

  15. Asymmetrically doped one-dimensional trans-polymers

    Caldas, Heron

    2009-01-01

    More than 30 years ago [H. Shirakawa, E.J. Louis, A.G. MacDiarmid, C.K. Chiang, A.J. Heeger, J. Chem. Soc. Chem. Comm. 578 (1977); S. Etemad, A.J. Heeger, Ann. Rev. Phys. Chem. 33 (1982) 443] it was discovered that doped trans-polyacetylene (CH) x , a one-dimensional (1D) conjugated polymer, exhibits electrical conductivity. In this work we show that an asymmetrically doped 1D trans-polymer has non-conventional properties, as compared to symmetrically doped systems. Depending on the level of asymmetry between the chemical potentials of the two involved fermionic species, the polymer can be in a partially or fully spin polarized state. Some possible experimental consequences of doped 1D trans-polymers used as 1D organic polarized conductors are discussed.

  16. Explicit Solutions for One-Dimensional Mean-Field Games

    Prazeres, Mariana

    2017-04-05

    In this thesis, we consider stationary one-dimensional mean-field games (MFGs) with or without congestion. Our aim is to understand the qualitative features of these games through the analysis of explicit solutions. We are particularly interested in MFGs with a nonmonotonic behavior, which corresponds to situations where agents tend to aggregate. First, we derive the MFG equations from control theory. Then, we compute explicit solutions using the current formulation and examine their behavior. Finally, we represent the solutions and analyze the results. This thesis main contributions are the following: First, we develop the current method to solve MFG explicitly. Second, we analyze in detail non-monotonic MFGs and discover new phenomena: non-uniqueness, discontinuous solutions, empty regions and unhappiness traps. Finally, we address several regularization procedures and examine the stability of MFGs.

  17. One-dimensional central-force problem, including radiation reaction

    Kasher, J.C.

    1976-01-01

    Two equal masses of equal charge magnitude (either attractive or repulsive) are held a certain distance apart for their entire past history. AT t = 0 one of them is either started from rest or given an initial velocity toward or away from the other charge. When the Dirac radiation-reaction force is included in the force equation, our Taylor-series numerical calculations lead to two types of nonphysical results for both the attractive and repulsive cases. In the attractive case, the moving charge either stops and moves back out to infinity, or violates energy conservation as it nears collision with the fixed charge. For the repulsive charges, the moving particle either eventually approaches and collides with the fixed one, or violates energy conservation as it goes out to infinity. These results lead us to conclude that the Lorentz-Dirac equation is not valid for the one-dimensional central-force problem

  18. Periodic transmission peak splitting in one dimensional disordered photonic structures

    Kriegel, Ilka; Scotognella, Francesco

    2016-08-01

    In the present paper we present ways to modulate the periodic transmission peaks arising in disordered one dimensional photonic structures with hundreds of layers. Disordered structures in which the optical length nd (n is the refractive index and d the layer thickness) is the same for each layer show regular peaks in their transmission spectra. A proper variation of the optical length of the layers leads to a splitting of the transmission peaks. Notably, the variation of the occurrence of high and low refractive index layers, gives a tool to tune also the width of the peaks. These results are of highest interest for optical application, such as light filtering, where the manifold of parameters allows a precise design of the spectral transmission ranges.

  19. Moving Least Squares Method for a One-Dimensional Parabolic Inverse Problem

    Baiyu Wang

    2014-01-01

    Full Text Available This paper investigates the numerical solution of a class of one-dimensional inverse parabolic problems using the moving least squares approximation; the inverse problem is the determination of an unknown source term depending on time. The collocation method is used for solving the equation; some numerical experiments are presented and discussed to illustrate the stability and high efficiency of the method.

  20. One-dimensional model for QCD at high energy

    Iancu, E.; Santana Amaral, J.T. de; Soyez, G.; Triantafyllopoulos, D.N.

    2007-01-01

    We propose a stochastic particle model in (1+1) dimensions, with one dimension corresponding to rapidity and the other one to the transverse size of a dipole in QCD, which mimics high-energy evolution and scattering in QCD in the presence of both saturation and particle-number fluctuations, and hence of pomeron loops. The model evolves via non-linear particle splitting, with a non-local splitting rate which is constrained by boost-invariance and multiple scattering. The splitting rate saturates at high density, so like the gluon emission rate in the JIMWLK evolution. In the mean field approximation obtained by ignoring fluctuations, the model exhibits the hallmarks of the BK equation, namely a BFKL-like evolution at low density, the formation of a traveling wave, and geometric scaling. In the full evolution including fluctuations, the geometric scaling is washed out at high energy and replaced by diffusive scaling. It is likely that the model belongs to the universality class of the reaction-diffusion process. The analysis of the model sheds new light on the pomeron loops equations in QCD and their possible improvements

  1. Gravitational wave emission from a bounded source: A treatment in the full nonlinear regime

    Oliveiral, H.P. de; Damiao Soares, I.

    2004-03-01

    The dynamics of a bounded gravitational collapsing configuration emitting gravitational waves is studied. The exterior spacetime is described by Robinson-Trautman geometries and have the Schwarzschild black hole as its final gravitational configuration, when the gravitational wave emission ceases. The full nonlinear regime is examined by using the Galerkin method that allows us to reduce the equations governing the dynamics to a finite-dimensional dynamical system, after a proper truncation procedure. Gravitational wave emission patterns from given initial configurations are exhibited for several phases of the collapse and the mass-loss ratio that characterizes the amount of mass extracted by the gravitational wave emission is evaluated. We obtain that the smaller initial mass M init of the configuration, the more rapidly the Schwarzschild solution is attained and a larger fraction of M init is lost in the process of gravitational wave emission. Within all our numerical experiments, the distribution of the mass fraction extracted by gravitational wave emission is shown to satisfy the distribution law of nonextensive statistics and this result is independent of the initial configurations considered. (author)

  2. Symmetry-projected variational approach to the one-dimensional Hubbard model

    Schmid, K.W.; Dahm, T.; Margueron, J.; Muether, H.

    2005-01-01

    We apply a variational method devised for the nuclear many-body problem to the one-dimensional Hubbard model with nearest neighbor hopping and periodic boundary conditions. The test wave function consist for each state out of a single Hartree-Fock determinant mixing all the sites (or momenta) as well as the spin projections of the electrons. Total spin and linear momentum are restored by projection methods before the variation. It is demonstrated that this approach reproduces the results of exact diagonalizations for half-filled N=12 and N=14 lattices not only for the energies and occupation numbers of the ground but also of the lowest excited states rather well. Furthermore, a system of ten electrons in an N=12 lattice is investigated and, finally, an N=30 lattice is studied. In addition to energies and occupation numbers we present the spectral functions computed with the help of the symmetry-projected wave functions as well

  3. Full wave dc-to-dc converter using energy storage transformers

    Moore, E. T.; Wilson, T. G.

    1969-01-01

    Full wave dc-to-dc converter, for an ion thrustor, uses energy storage transformers to provide a method of dc-to-dc conversion and regulation. The converter has a high degree of physical simplicity, is lightweight and has high efficiency.

  4. Monte-Carlo Orbit/Full Wave Simulation of Fast Alfven Wave (FW) Damping on Resonant Ions in Tokamaks

    Choi, M.; Chan, V.S.; Pinsker, R.I.; Tang, V.; Bonoli, P.; Wright, J.

    2005-01-01

    To simulate the resonant interaction of fast Alfven wave (FW) heating and Coulomb collisions on energetic ions, including finite orbit effects, a Monte-Carlo code ORBIT-RF has been coupled with a 2D full wave code TORIC4. ORBIT-RF solves Hamiltonian guiding center drift equations to follow trajectories of test ions in 2D axisymmetric numerical magnetic equilibrium under Coulomb collisions and ion cyclotron radio frequency quasi-linear heating. Monte-Carlo operators for pitch-angle scattering and drag calculate the changes of test ions in velocity and pitch angle due to Coulomb collisions. A rf-induced random walk model describing fast ion stochastic interaction with FW reproduces quasi-linear diffusion in velocity space. FW fields and its wave numbers from TORIC are passed on to ORBIT-RF to calculate perpendicular rf kicks of resonant ions valid for arbitrary cyclotron harmonics. ORBIT-RF coupled with TORIC using a single dominant toroidal and poloidal wave number has demonstrated consistency of simulations with recent DIII-D FW experimental results for interaction between injected neutral-beam ions and FW, including measured neutron enhancement and enhanced high energy tail. Comparison with C-Mod fundamental heating discharges also yielded reasonable agreement

  5. One-dimensional flame instability and control of burning in fire-chamber

    Victor E. Volkov

    2015-03-01

    Full Text Available The flame stability with regard to one-dimensional exponential perturbations both for the combustion in the fire-chamber and the flame propagating in closed tubes or chambers is investigated. It is proved that both stability and instability are possible for the combustion process. At the same time the one-dimensional flame instability is guaranteed near the front wall of the fire-chamber where the fuel supply is realized. Therefore the control of combustion in the fire-chamber leads to support of the flame at the maximum possible distance from the front wall of the fire-chamber to prevent the vibratory combustion or to diminish intensity of pulsations if these pulsations are inevitable.

  6. Advanced One-Dimensional Entrained-Flow Gasifier Model Considering Melting Phenomenon of Ash

    Jinsu Kim

    2018-04-01

    Full Text Available A one-dimensional model is developed to represent the ash-melting phenomenon, which was not considered in the previous one-dimensional (1-D entrained-flow gasifier model. We include sensible heat of slag and the fusion heat of ash in the heat balance equation. To consider the melting of ash, we propose an algorithm that calculates the energy balance for three scenarios based on temperature. We also use the composition and the thermal properties of anorthite mineral to express ash. gPROMS for differential equations is used to solve this algorithm in a simulation; the results include coal conversion, gas composition, and temperature profile. Based on the Texaco pilot plant gasifier, we validate our model. Our results show good agreement with previous experimental data. We conclude that the sensible heat of slag and the fusion heat of ash must be included in the entrained flow gasifier model.

  7. Efficient full wave code for the coupling of large multirow multijunction LH grills.

    Preinhaelter, Josef; Hillairet, J.; Milanesio, D.; Maggiora, R.; Urban, Jakub; Vahala, L.; Vahala, G.

    2017-01-01

    Roč. 57, č. 11 (2017), č. článku 116060. ISSN 0029-5515 R&D Projects: GA MŠk(CZ) 8D15001; GA MŠk(CZ) LM2015045 Institutional support: RVO:61389021 Keywords : lower hybrid waves * coupling * large multirow multijunction grills * tokamak * full-wave Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 3.307, year: 2016 http://iopscience.iop.org/article/10.1088/1741-4326/aa7f4f/meta

  8. BERMUDA-1DG: a one-dimensional photon transport code

    Suzuki, Tomoo; Hasegawa, Akira; Nakashima, Hiroshi; Kaneko, Kunio.

    1984-10-01

    A one-dimensional photon transport code BERMUDA-1DG has been developed for spherical and infinite slab geometries. The purpose of development is to equip the function of gamma rays calculation for the BERMUDA code system, which was developed by 1983 only for neutron transport calculation as a preliminary version. A group constants library has been prepared for 30 nuclides, and it now consists of the 36-group total cross sections and secondary gamma ray yields by the 120-group neutron flux. For the Compton scattering, group-angle transfer matrices are accurately obtained by integrating the Klein-Nishina formula taking into account the energy and scattering angle correlation. The pair production cross sections are now calculated in the code from atomic number and midenergy of each group. To obtain angular flux distribution, the transport equation is solved in the same way as in case of neutron, using the direct integration method in a multigroup model. Both of an independent gamma ray source problem and a neutron-gamma source problem are possible to be solved. This report is written as a user's manual with a brief description of the calculational method. (author)

  9. Spin glasses and algorithm benchmarks: A one-dimensional view

    Katzgraber, H G

    2008-01-01

    Spin glasses are paradigmatic models that deliver concepts relevant for a variety of systems. However, rigorous analytical results are difficult to obtain for spin-glass models, in particular for realistic short-range models. Therefore large-scale numerical simulations are the tool of choice. Concepts and algorithms derived from the study of spin glasses have been applied to diverse fields in computer science and physics. In this work a one-dimensional long-range spin-glass model with power-law interactions is discussed. The model has the advantage over conventional systems in that by tuning the power-law exponent of the interactions the effective space dimension can be changed thus effectively allowing the study of large high-dimensional spin-glass systems to address questions as diverse as the existence of an Almeida-Thouless line, ultrametricity and chaos in short range spin glasses. Furthermore, because the range of interactions can be changed, the model is a formidable test-bed for optimization algorithms

  10. One-dimensional transient radiative transfer by lattice Boltzmann method.

    Zhang, Yong; Yi, Hongliang; Tan, Heping

    2013-10-21

    The lattice Boltzmann method (LBM) is extended to solve transient radiative transfer in one-dimensional slab containing scattering media subjected to a collimated short laser irradiation. By using a fully implicit backward differencing scheme to discretize the transient term in the radiative transfer equation, a new type of lattice structure is devised. The accuracy and computational efficiency of this algorithm are examined firstly. Afterwards, effects of the medium properties such as the extinction coefficient, the scattering albedo and the anisotropy factor, and the shapes of laser pulse on time-resolved signals of transmittance and reflectance are investigated. Results of the present method are found to compare very well with the data from the literature. For an oblique incidence, the LBM results in this paper are compared with those by Monte Carlo method generated by ourselves. In addition, transient radiative transfer in a two-Layer inhomogeneous media subjected to a short square pulse irradiation is investigated. At last, the LBM is further extended to study the transient radiative transfer in homogeneous medium with a refractive index discontinuity irradiated by the short pulse laser. Several trends on the time-resolved signals different from those for refractive index of 1 (i.e. refractive-index-matched boundary) are observed and analysed.

  11. One dimensional coordination polymers: Synthesis, crystal structures and spectroscopic properties

    Karaağaç, Dursun; Kürkçüoğlu, Güneş Süheyla; Şenyel, Mustafa; Şahin, Onur

    2016-11-01

    Two new one dimensional (1D) cyanide complexes, namely [M(4-aepy)2(H2O)2][Pt(CN)4], (4-aepy = 4-(2-aminoethyl)pyridine M = Cu(II) (1) or Zn(II) (2)), have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal and elemental analyses techniques. The crystallographic analyses reveal that 1 and 2 are isomorphous and isostructural, and crystallize in the monoclinic system and C2 space group. The Pt(II) ions are coordinated by four cyanide-carbon atoms in the square-planar geometry and the [Pt(CN)4]2- ions act as a counter ion. The M(II) ions display an N4O2 coordination sphere with a distorted octahedral geometry, the nitrogen donors belonging to four molecules of the organic 4-aepy that act as unidentate ligands and two oxygen atoms from aqua ligands. The crystal structures of 1 and 2 are similar each other and linked via intermolecular hydrogen bonding, Pt⋯π interactions to form 3D supramolecular network. Vibration assignments of all the observed bands are given and the spectral features also supported to the crystal structures of the complexes.

  12. Tunneling and resonant conductance in one-dimensional molecular structures

    Kozhushner, M.A.; Posvyanskii, V.S.; Oleynik, I.I.

    2005-01-01

    We present a theory of tunneling and resonant transitions in one-dimensional molecular systems which is based on Green's function theory of electron sub-barrier scattering off the structural units (or functional groups) of a molecular chain. We show that the many-electron effects are of paramount importance in electron transport and they are effectively treated using a formalism of sub-barrier scattering operators. The method which calculates the total scattering amplitude of the bridge molecule not only predicts the enhancement of the amplitude of tunneling transitions in course of tunneling electron transfer through onedimensional molecular structures but also allows us to interpret conductance mechanisms by calculating the bound energy spectrum of the tunneling electron, the energies being obtained as poles of the total scattering amplitude of the bridge molecule. We found that the resonant tunneling via bound states of the tunneling electron is the major mechanism of electron conductivity in relatively long organic molecules. The sub-barrier scattering technique naturally includes a description of tunneling in applied electric fields which allows us to calculate I-V curves at finite bias. The developed theory is applied to explain experimental findings such as bridge effect due to tunneling through organic molecules, and threshold versus Ohmic behavior of the conductance due to resonant electron transfer

  13. New Poisson–Boltzmann type equations: one-dimensional solutions

    Lee, Chiun-Chang; Lee, Hijin; Hyon, YunKyong; Lin, Tai-Chia; Liu, Chun

    2011-01-01

    The Poisson–Boltzmann (PB) equation is conventionally used to model the equilibrium of bulk ionic species in different media and solvents. In this paper we study a new Poisson–Boltzmann type (PB n ) equation with a small dielectric parameter ε 2 and non-local nonlinearity which takes into consideration the preservation of the total amount of each individual ion. This equation can be derived from the original Poisson–Nernst–Planck system. Under Robin-type boundary conditions with various coefficient scales, we demonstrate the asymptotic behaviours of one-dimensional solutions of PB n equations as the parameter ε approaches zero. In particular, we show that in case of electroneutrality, i.e. α = β, solutions of 1D PB n equations have a similar asymptotic behaviour as those of 1D PB equations. However, as α ≠ β (non-electroneutrality), solutions of 1D PB n equations may have blow-up behaviour which cannot be found in 1D PB equations. Such a difference between 1D PB and PB n equations can also be verified by numerical simulations

  14. Localization properties of one-dimensional electrified chains

    Ouasti, R.; Brezini, A.; Zekri, N.

    1993-08-01

    A Kronig-Penney model with a constant electric filed for a non-interacting electron is used to study the transmission properties of Anderson transition in one-dimensional (1-D) systems with disordered strengths of δ-function potentials. we examined the cases where the potential varies uniformly from O to W (barriers) or from -W to O (wells) for a given disorder W. Mainly, we observe unexpected abrupt transition at the points E + Fx = n 2 π 2 . However, these transitions are related to the small oscillations observed by Soukoulis et al. in the mixed case (wells and barriers). An interesting feature in the wells is that in the presence of a small field the states become more localized and the localization length decrease up to a minimum for a critical value F m . In the end, we have studied the effect of the disorder on the Anderson transition by the mean of the participation ratio and the localization length. (author). 27 refs, 6 figs

  15. SUSY-hierarchy of one-dimensional reflectionless potentials

    Maydanyuk, Sergei P.

    2005-01-01

    A class of one-dimensional reflectionless potentials is studied. It is found that all possible types of the reflectionless potentials can be combined into one SUSY-hierarchy with a constant potential. An approach for determination of a general form of the reflectionless potential on the basis of construction of such a hierarchy by the recurrent method is proposed. A general integral form of interdependence between superpotentials with neighboring numbers of this hierarchy, opening a possibility to find new reflectionless potentials, is found and has a simple analytical view. It is supposed that any possible type of the reflectionless potential can be expressed through finite number of elementary functions (unlike some presentations of the reflectionless potentials, which are constructed on the basis of soliton solutions or are shape invariant in one or many steps with involving scaling of parameters, and are expressed through series). An analysis of absolute transparency existence for the potential which has the inverse power dependence on space coordinate (and here tunneling is possible), i.e., which has the form V (x) = ± α/ vertical bar x-x 0 vertical bar n (where α and x 0 are constants, n is natural number), is fulfilled. It is shown that such a potential can be reflectionless at n = 2 only. A SUSY-hierarchy of the inverse power reflectionless potentials is constructed. Isospectral expansions of this hierarchy are analyzed

  16. Integral Transport Theory in One-dimensional Geometries

    Carlvik, I

    1966-06-15

    A method called DIT (Discrete Integral Transport) has been developed for the numerical solution of the transport equation in one-dimensional systems. The characteristic features of the method are Gaussian integration over the coordinate as described by Kobayashi and Nishihara, and a particular scheme for the calculation of matrix elements in annular and spherical geometry that has been used for collision probabilities in earlier Flurig programmes. The paper gives a general theory including such things as anisotropic scattering and multi-pole fluxes, and it gives a brief description of the Flurig scheme. Annular geometry is treated in some detail, and corresponding formulae are given for spherical and plane geometry. There are many similarities between DIT and the method of collision probabilities. DIT is in many cases faster, because for a certain accuracy in the fluxes DIT often needs fewer space points than the method of collision probabilities needs regions. Several computer codes using DIT, both one-group and multigroup, have been written. It is anticipated that experience gained in calculations with these codes will be reported in another paper.

  17. Quantum one dimensional spin systems. Disorder and impurities

    Brunel, V.

    1999-01-01

    This thesis presents three studies that are respectively the spin-1 disordered chain, the non magnetic impurities in the spin-1/2 chain and the reaction-diffusion process. The spin-1 chain of weak disorder is performed by the Abelian bosonization and the renormalization group. This allows to take into account the competition between the disorder and the interactions and predicts the effects of various spin-1 anisotropy chain phases under many different disorders. A second work uses the non magnetic impurities as local probes of the correlations in the spin-1/2 chain. When the impurities are connected to the chain boundary, the author predicts a temperature dependence of the relaxation rate (1/T) of the nuclear spin impurities, different from the case of these impurities connected to the whole chain. The last work deals with one dimensional reaction-diffusion problem. The Jordan-Wigner transformation allows to consider a fermionic field theory that critical exponents follow from the renormalization group. (A.L.B.)

  18. One-dimensional two-phase thermal hydraulics (ENSTA course)

    Olive, J.

    1995-11-01

    This course is part of the ENSTA 3rd year thermal hydraulics program (nuclear power option). Its purpose is to provide the theoretical basis and main physical notions pertaining to two-phase flow, mainly focussed on water-steam flows. The introduction describes the physical specificities of these flows, emphasizing their complexity. The mathematical bases are then presented (partial derivative equations), leading to a one-dimensional type, simplified description. Balances drawn up for a pipe length volume are used to introduce the mass conservation. motion and energy equations for each phase. Various postulates used to simplify two-phase models are presented, culminating in homogeneous model definitions and equations, several common examples of which are given. The model is then applied to the calculation of pressure drops in two-phase flows. This involves presenting the models most frequently used to represent pressure drops by friction or due to pipe irregularities, without giving details (numerical values of parameters). This chapter terminates with a brief description of static and dynamic instabilities in two-phase flows. Finally, heat transfer conditions frequently encountered in liquid-steam flows are described, still in the context of a 1D model. This chapter notably includes reference to under-saturated boiling conditions and the various forms of DNB. The empirical heat transfer laws are not discussed in detail. Additional material is appended, some of which is in the form of corrected exercises. (author). 6 appends

  19. One-dimensional long-range percolation: A numerical study

    Gori, G.; Michelangeli, M.; Defenu, N.; Trombettoni, A.

    2017-07-01

    In this paper we study bond percolation on a one-dimensional chain with power-law bond probability C /rd +σ , where r is the distance length between distinct sites and d =1 . We introduce and test an order-N Monte Carlo algorithm and we determine as a function of σ the critical value Cc at which percolation occurs. The critical exponents in the range 0 values for Cc are compared with a known exact bound, while the critical exponent ν is compared with results from mean-field theory, from an expansion around the point σ =1 and from the ɛ -expansion used with the introduction of a suitably defined effective dimension deff relating the long-range model with a short-range one in dimension deff. We finally present a formulation of our algorithm for bond percolation on general graphs, with order N efficiency on a large class of graphs including short-range percolation and translationally invariant long-range models in any spatial dimension d with σ >0 .

  20. Magnetic ordering in arrays of one-dimensional nanoparticle chains

    Serantes, D; Baldomir, D; Pereiro, M; Hernando, B; Prida, V M; Sanchez Llamazares, J L; Zhukov, A; Ilyn, M; Gonzalez, J

    2009-01-01

    The magnetic order in parallel-aligned one-dimensional (1D) chains of magnetic nanoparticles is studied using a Monte Carlo technique. If the easy anisotropy axes are collinear along the chains a macroscopic mean-field approach indicates antiferromagnetic (AFM) order even when no interparticle interactions are taken into account, which evidences that a mean-field treatment is inadequate for the study of the magnetic order in these highly anisotropic systems. From the direct microscopic analysis of the evolution of the magnetic moments, we observe spontaneous intra-chain ferromagnetic (FM)-type and inter-chain AFM-type ordering at low temperatures (although not completely regular) for the easy-axes collinear case, whereas a random distribution of the anisotropy axes leads to a sort of intra-chain AFM arrangement with no inter-chain regular order. When the magnetic anisotropy is neglected a perfectly regular intra-chain FM-like order is attained. Therefore it is shown that the magnetic anisotropy, and particularly the spatial distribution of the easy axes, is a key parameter governing the magnetic ordering type of 1D-nanoparticle chains.

  1. Transmission properties of one-dimensional ternary plasma photonic crystals

    Shiveshwari, Laxmi; Awasthi, S. K.

    2015-01-01

    Omnidirectional photonic band gaps (PBGs) are found in one-dimensional ternary plasma photonic crystals (PPC) composed of single negative metamaterials. The band characteristics and transmission properties are investigated through the transfer matrix method. We show that the proposed structure can trap light in three-dimensional space due to the elimination of Brewster's angle transmission resonance allowing the existence of complete PBG. The results are discussed in terms of incident angle, layer thickness, dielectric constant of the dielectric material, and number of unit cells (N) for TE and TM polarizations. It is seen that PBG characteristics is apparent even in an N ≥ 2 system, which is weakly sensitive to the incident angle and completely insensitive to the polarization. Finite PPC could be used for multichannel transmission filter without introducing any defect in the geometry. We show that the locations of the multichannel transmission peaks are in the allowed band of the infinite structure. The structure can work as a single or multichannel filter by varying the number of unit cells. Binary PPC can also work as a polarization sensitive tunable filter

  2. Energy Current Cumulants in One-Dimensional Systems in Equilibrium

    Dhar, Abhishek; Saito, Keiji; Roy, Anjan

    2018-06-01

    A recent theory based on fluctuating hydrodynamics predicts that one-dimensional interacting systems with particle, momentum, and energy conservation exhibit anomalous transport that falls into two main universality classes. The classification is based on behavior of equilibrium dynamical correlations of the conserved quantities. One class is characterized by sound modes with Kardar-Parisi-Zhang scaling, while the second class has diffusive sound modes. The heat mode follows Lévy statistics, with different exponents for the two classes. Here we consider heat current fluctuations in two specific systems, which are expected to be in the above two universality classes, namely, a hard particle gas with Hamiltonian dynamics and a harmonic chain with momentum conserving stochastic dynamics. Numerical simulations show completely different system-size dependence of current cumulants in these two systems. We explain this numerical observation using a phenomenological model of Lévy walkers with inputs from fluctuating hydrodynamics. This consistently explains the system-size dependence of heat current fluctuations. For the latter system, we derive the cumulant-generating function from a more microscopic theory, which also gives the same system-size dependence of cumulants.

  3. 17th century treatments of one-dimensional collisions

    Goehring, G.D.

    1975-01-01

    The issue of conservation in the collisions of bodies aroused considerable interest in the period of its initial investigation. Descartes asserted that the quantity of motion, the scalar product of the mass and speed, was the quantity that was conserved. Huygens, with the aid of his relativity of motion principle, recognized that it was not Descartes' scalar quantity that was conserved, but instead another scalar quality, the product of the mass and the square of the speed, whose total remained constant. Newton discovered that Descartes' quantity was conserved if considered a vector quantity, and thereby announced the principle of conservation of momentum. Leibniz recognized the conservation of Newton's momentum, and also the conservation of vis viva, the same scalar quantity that Huygens has earlier proposed. Although recognition of the immense importance of these principles had to await further developments in physics, the original formulation of these conservation principles, resulting from the analysis of one-dimensional collisions, was completed by the end of the 17th century. (U.K.)

  4. Negative refraction angular characterization in one-dimensional photonic crystals.

    Lugo, Jesus Eduardo; Doti, Rafael; Faubert, Jocelyn

    2011-04-06

    Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.

  5. One-dimensional quantum walk with a moving boundary

    Kwek, Leong Chuan; Setiawan

    2011-01-01

    Quantum walks are interesting models with potential applications to quantum algorithms and physical processes such as photosynthesis. In this paper, we study two models of one-dimensional quantum walks, namely, quantum walks with a moving absorbing wall and quantum walks with one stationary and one moving absorbing wall. For the former, we calculate numerically the survival probability, the rate of change of average position, and the rate of change of standard deviation of the particle's position in the long time limit for different wall velocities. Moreover, we also study the asymptotic behavior and the dependence of the survival probability on the initial particle's state. While for the latter, we compute the absorption probability of the right stationary wall for different velocities and initial positions of the left wall boundary. The results for these two models are compared with those obtained for the classical model. The difference between the results obtained for the quantum and classical models can be attributed to the difference in the probability distributions.

  6. Numerical modelling of random walk one-dimensional diffusion

    Vamos, C.; Suciu, N.; Peculea, M.

    1996-01-01

    The evolution of a particle which moves on a discrete one-dimensional lattice, according to a random walk low, approximates better the diffusion process smaller the steps of the spatial lattice and time are. For a sufficiently large assembly of particles one can assume that their relative frequency at lattice knots approximates the distribution function of the diffusion process. This assumption has been tested by simulating on computer two analytical solutions of the diffusion equation: the Brownian motion and the steady state linear distribution. To evaluate quantitatively the similarity between the numerical and analytical solutions we have used a norm given by the absolute value of the difference of the two solutions. Also, a diffusion coefficient at any lattice knots and moment of time has been calculated, by using the numerical solution both from the diffusion equation and the particle flux given by Fick's low. The difference between diffusion coefficient of analytical solution and the spatial lattice mean coefficient of numerical solution constitutes another quantitative indication of the similarity of the two solutions. The results obtained show that the approximation depends first on the number of particles at each knot of the spatial lattice. In conclusion, the random walk is a microscopic process of the molecular dynamics type which permits simulations precision of the diffusion processes with given precision. The numerical method presented in this work may be useful both in the analysis of real experiments and for theoretical studies

  7. Fractal geometry in an expanding, one-dimensional, Newtonian universe.

    Miller, Bruce N; Rouet, Jean-Louis; Le Guirriec, Emmanuel

    2007-09-01

    Observations of galaxies over large distances reveal the possibility of a fractal distribution of their positions. The source of fractal behavior is the lack of a length scale in the two body gravitational interaction. However, even with new, larger, sample sizes from recent surveys, it is difficult to extract information concerning fractal properties with confidence. Similarly, three-dimensional N-body simulations with a billion particles only provide a thousand particles per dimension, far too small for accurate conclusions. With one-dimensional models these limitations can be overcome by carrying out simulations with on the order of a quarter of a million particles without compromising the computation of the gravitational force. Here the multifractal properties of two of these models that incorporate different features of the dynamical equations governing the evolution of a matter dominated universe are compared. For each model at least two scaling regions are identified. By employing criteria from dynamical systems theory it is shown that only one of them can be geometrically significant. The results share important similarities with galaxy observations, such as hierarchical clustering and apparent bifractal geometry. They also provide insights concerning possible constraints on length and time scales for fractal structure. They clearly demonstrate that fractal geometry evolves in the mu (position, velocity) space. The observed patterns are simply a shadow (projection) of higher-dimensional structure.

  8. MARG1D: One dimensional outer region matching data code

    Tokuda, Shinji; Watanabe, Tomoko.

    1995-08-01

    A code MARG1D has been developed which computes outer region matching data of the one dimensional Newcomb equation. Matching data play an important role in the resistive (and non ideal) Magneto-hydrodynamic (MHD) stability analysis in a tokamak plasma. The MARG1D code computes matching data by using the boundary value method or by the eigenvalue method. Variational principles are derived for the problems to be solved and a finite element method is applied. Except for the case of marginal stability, the eigenvalue method is equivalent to the boundary value method. However, the eigenvalue method has the several advantages: it is a new method of ideal MHD stability analysis for which the marginally stable state can be identified, and it guarantees numerical stability in computing matching data close to marginal stability. We perform detailed numerical experiments for a model equation with analytical solutions and for the Newcomb equation in the m=1 mode theory. Numerical experiments show that MARG1D code gives the matching data with numerical stability and high accuracy. (author)

  9. Transmission properties of one-dimensional ternary plasma photonic crystals

    Shiveshwari, Laxmi [Department of Physics, K. B. Womens' s College, Hazaribagh 825 301 (India); Awasthi, S. K. [Department of Physics and Material Science and Engineering, Jaypee Institute of Information Technology, Noida 201 304 (India)

    2015-09-15

    Omnidirectional photonic band gaps (PBGs) are found in one-dimensional ternary plasma photonic crystals (PPC) composed of single negative metamaterials. The band characteristics and transmission properties are investigated through the transfer matrix method. We show that the proposed structure can trap light in three-dimensional space due to the elimination of Brewster's angle transmission resonance allowing the existence of complete PBG. The results are discussed in terms of incident angle, layer thickness, dielectric constant of the dielectric material, and number of unit cells (N) for TE and TM polarizations. It is seen that PBG characteristics is apparent even in an N ≥ 2 system, which is weakly sensitive to the incident angle and completely insensitive to the polarization. Finite PPC could be used for multichannel transmission filter without introducing any defect in the geometry. We show that the locations of the multichannel transmission peaks are in the allowed band of the infinite structure. The structure can work as a single or multichannel filter by varying the number of unit cells. Binary PPC can also work as a polarization sensitive tunable filter.

  10. One-dimensional magnetophotonic crystals with magnetooptical double layers

    Berzhansky, V. N.; Shaposhnikov, A. N.; Prokopov, A. R.; Karavainikov, A. V.; Mikhailova, T. V.; Lukienko, I. N.; Kharchenko, Yu. N.; Golub, V. O.; Salyuk, O. Yu.; Belotelov, V. I.

    2016-01-01

    One-dimensional magnetophotonic microcavity crystals with nongarnet dielectric mirrors are created and investigated. The defect layers in the magnetophotonic crystals are represented by two bismuth-substituted yttrium iron garnet Bi:YIG layers with various bismuth contents in order to achieve a high magnetooptical response of the crystals. The parameters of the magnetophotonic crystal layers are optimized by numerical solution of the Maxwell equations by the transfer matrix method to achieve high values of Faraday rotation angle Θ F and magnetooptical Q factor. The calculated and experimental data agree well with each other. The maximum values of Θ F =–20.6°, Q = 8.1° at a gain t = 16 are obtained for magnetophotonic crystals with m = 7 pairs of layers in Bragg mirrors, and the parameters obtained for crystals with m = 4 and t = 8.5 are Θ F =–12.5° and Q = 14.3°. It is shown that, together with all-garnet and multimicrocavities magnetophotonic crystals, such structures have high magnetooptical characteristics.

  11. One-dimensional magnetophotonic crystals with magnetooptical double layers

    Berzhansky, V. N., E-mail: v.n.berzhansky@gmail.com; Shaposhnikov, A. N.; Prokopov, A. R.; Karavainikov, A. V.; Mikhailova, T. V. [V.I. Vernadsky Crimean Federal University (Russian Federation); Lukienko, I. N.; Kharchenko, Yu. N., E-mail: kharcenko@ilt.kharkov.ua [National Academy of Sciences of Ukraine, Verkin Institute for Low Temperature Physics and Engineering (Ukraine); Golub, V. O., E-mail: v-o-golub@yahoo.com; Salyuk, O. Yu. [National Academy of Sciences of Ukraine, Institute of Magnetism (Ukraine); Belotelov, V. I., E-mail: belotelov@physics.msu.ru [Russian Quantum Center (Russian Federation)

    2016-11-15

    One-dimensional magnetophotonic microcavity crystals with nongarnet dielectric mirrors are created and investigated. The defect layers in the magnetophotonic crystals are represented by two bismuth-substituted yttrium iron garnet Bi:YIG layers with various bismuth contents in order to achieve a high magnetooptical response of the crystals. The parameters of the magnetophotonic crystal layers are optimized by numerical solution of the Maxwell equations by the transfer matrix method to achieve high values of Faraday rotation angle Θ{sub F} and magnetooptical Q factor. The calculated and experimental data agree well with each other. The maximum values of Θ{sub F} =–20.6°, Q = 8.1° at a gain t = 16 are obtained for magnetophotonic crystals with m = 7 pairs of layers in Bragg mirrors, and the parameters obtained for crystals with m = 4 and t = 8.5 are Θ{sub F} =–12.5° and Q = 14.3°. It is shown that, together with all-garnet and multimicrocavities magnetophotonic crystals, such structures have high magnetooptical characteristics.

  12. Approximate approaches to the one-dimensional finite potential well

    Singh, Shilpi; Pathak, Praveen; Singh, Vijay A

    2011-01-01

    The one-dimensional finite well is a textbook problem. We propose approximate approaches to obtain the energy levels of the well. The finite well is also encountered in semiconductor heterostructures where the carrier mass inside the well (m i ) is taken to be distinct from mass outside (m o ). A relevant parameter is the mass discontinuity ratio β = m i /m o . To correctly account for the mass discontinuity, we apply the BenDaniel-Duke boundary condition. We obtain approximate solutions for two cases: when the well is shallow and when the well is deep. We compare the approximate results with the exact results and find that higher-order approximations are quite robust. For the shallow case, the approximate solution can be expressed in terms of a dimensionless parameter σ l = 2m o V 0 L 2 /ℎ 2 (or σ = β 2 σ l for the deep case). We show that the lowest-order results are related by a duality transform. We also discuss how the energy upscales with L (E∼1/L γ ) and obtain the exponent γ. Exponent γ → 2 when the well is sufficiently deep and β → 1. The ratio of the masses dictates the physics. Our presentation is pedagogical and should be useful to students on a first course on elementary quantum mechanics or low-dimensional semiconductors.

  13. One-Dimensional Electron Transport Layers for Perovskite Solar Cells

    Thakur, Ujwal K.; Kisslinger, Ryan; Shankar, Karthik

    2017-01-01

    The electron diffusion length (Ln) is smaller than the hole diffusion length (Lp) in many halide perovskite semiconductors meaning that the use of ordered one-dimensional (1D) structures such as nanowires (NWs) and nanotubes (NTs) as electron transport layers (ETLs) is a promising method of achieving high performance halide perovskite solar cells (HPSCs). ETLs consisting of oriented and aligned NWs and NTs offer the potential not merely for improved directional charge transport but also for the enhanced absorption of incoming light and thermodynamically efficient management of photogenerated carrier populations. The ordered architecture of NW/NT arrays affords superior infiltration of a deposited material making them ideal for use in HPSCs. Photoconversion efficiencies (PCEs) as high as 18% have been demonstrated for HPSCs using 1D ETLs. Despite the advantages of 1D ETLs, there are still challenges that need to be overcome to achieve even higher PCEs, such as better methods to eliminate or passivate surface traps, improved understanding of the hetero-interface and optimization of the morphology (i.e., length, diameter, and spacing of NWs/NTs). This review introduces the general considerations of ETLs for HPSCs, deposition techniques used, and the current research and challenges in the field of 1D ETLs for perovskite solar cells. PMID:28468280

  14. Stepwise Nanopore Evolution in One-Dimensional Nanostructures

    Choi, Jang Wook

    2010-04-14

    We report that established simple lithium (Li) ion battery cycles can be used to produce nanopores inside various useful one-dimensional (1D) nanostructures such as zinc oxide, silicon, and silver nanowires. Moreover, porosities of these 1D nanomaterials can be controlled in a stepwise manner by the number of Li-battery cycles. Subsequent pore characterization at the end of each cycle allows us to obtain detailed snapshots of the distinct pore evolution properties in each material due to their different atomic diffusion rates and types of chemical bonds. Also, this stepwise characterization led us to the first observation of pore size increases during cycling, which can be interpreted as a similar phenomenon to Ostwald ripening in analogous nanoparticle cases. Finally, we take advantage of the unique combination of nanoporosity and 1D materials and demonstrate nanoporous silicon nanowires (poSiNWs) as excellent supercapacitor (SC) electrodes in high power operations compared to existing devices with activated carbon. © 2010 American Chemical Society.

  15. Neutral axis determination of full size concrete structures using coda wave measurements

    Jiang, Hanwan; Zhan, Hanyu; Zhuang, Chenxu; Jiang, Ruinian

    2018-03-01

    Coda waves experiencing multiple scattering behaviors are sensitive to weak changes occurring in media. In this paper, a typical four-point bending test with varied external loads is conducted on a 30-meter T-beam that is removed from a bridge after being in service for 15 years, and the coda wave signals are collected with a couple of sources-receivers pairs. Then the observed coda waves at different loads are compared to calculate their relative velocity variations, which are utilized as the parameter to distinct the compression and tensile zones as well as determine the neutral axis position. Without any prior knowledge of the concrete beam, the estimated axis position agrees well with the associated strain gage measurement results, and the zones bearing stress and tension behaviors are indicated. The presented work offers significant potential for Non-Destructive Testing and Evaluation of full-size concrete structures in future work.

  16. A Full-Wave Seismic Tomography for the Crustal Structure in the Metropolitan Beijing Region

    Sun, A.; Zhao, L.; Chen, Q.

    2008-12-01

    The greater Beijing metropolitan region is located in an old cratonic block in northeast China with complex geology and several large historic earthquakes, such as the Sanhe-Pinggu earthquake (~M8.0) in 1679, the Xingtai earthquake (M7.2) in 1966, and the Tangshan earthquake (M7.8) in 1976. To enhance our understanding of the crustal structure and the seismotectonics under this region, we conduct a full-wave three-dimensional (3D) tomographic study of this region using the waveforms recorded by the newly established Beijing metropolitan digital seismic network. Since the Beijing network was put into operation in October 2001, there have been 89 local earthquakes of magnitude 3.0 and above. From these, we selected 23 events of magnitude 3.2 and above and obtained their waveform records at 50 stations within our area of interest. The types of instruments at these stations include broadband, short-period and very broadband. First-motion focal mechanisms were determined for these events. We used a regional 3D model obtained by seismic reflection surveys as the reference model and calculated the synthetic seismograms by the finite-difference method. In this first attempt at finite- frequency tomography for the Beijing region, we focus on the variation of the P-wave speed using the first- arriving P waves. We measure the frequency-dependent traveltime anomalies of the P waves by the cross- correlation between observed and synthetic P waveforms within several discrete frequency bands between 20-sec and 5-sec periods. The sensitivity or Frechet kernels of these measurements for the perturbations in P-wave speed were computed by the same finite-difference method. We will present the preliminary result in our full-wave seismic tomography for the Beijing region.

  17. Time-domain full waveform inversion using the gradient preconditioning based on transmitted waves energy

    Zhang, Xiao-bo

    2017-06-01

    The gradient preconditioning approach based on seismic wave energy can effectively avoid the huge storage consumption in the gradient preconditioning algorithms based on Hessian matrices in time-domain full waveform inversion (FWI), but the accuracy is affected by the energy of reflected waves when strong reflectors are present in velocity model. To address this problem, we propose a gradient preconditioning method, which scales the gradient based on the energy of the “approximated transmitted wavefield” simulated by the nonreflecting acoustic wave equation. The method does not require computing or storing the Hessian matrix or its inverse. Furthermore, it can effectively eliminate the effects caused by geometric diffusion and non-uniformity illumination on gradient. The results of model experiments confirm that the time-domain FWI using the gradient preconditioning based on transmitted waves energy can achieve higher inversion precision for high-velocity body and the deep strata below when compared with using the gradient preconditioning based on seismic waves energy.

  18. Local full-wave energy and quasilinear analysis in nonuniform plasmas

    Smithe, D.N.

    1989-01-01

    The subject of local wave energy in plasmas is treated via quasilinear theory from the dual perspectives of the action-angle formalism and gyrokinetic analysis. An extension is presented to all orders in the gyroradius of the self-consistent wave-propagation/quasilinear-absorption problem using gyrokinetics. Questions of when and under what conditions local energy should be of definite sign are answered using the action-angle formalism. An important result is that the ''dielectric operators'' of the linearized wave equation and of the local energy are not the same, a fact which is obscured when the eikonal or WKB assumption is invoked. Even though the two dielectrics are very different in character, it is demonstrated that they are nevertheless related by a simple mathematical statement. This study was originally motivated by concern over the question of local energy for r.f.-heating of plasmas, where in certain instances, full-wave effects such as refraction, strong absorption, and mode conversion are of primary importance. Fundamentally, the r.f.-absorption must equate with the energy moment of the quasilinear term to achieve a correct energy balance. This fact governs the derivation (as opposed to postulation) of the local absorption. The troublesome ''kinetic flux'' may then be chosen (it is not unique) to satisfy a wave-energy balance relation with the Poynting flux and local absorption. It is shown that at least one such choice reduces asymptotically to the Stix form away from nonuniformities. (author)

  19. Full-Wave Techniques for the Analysis of Electrodynamics and Coherent Quantum Transport in Graphene Nanodevices.

    Luca Pierantoni

    2012-11-01

    Full Text Available We report on full-wave techniques in the frequency (energy-domain and the time-domain, aimed at the investigation of the combined electromagnetic-coherent transport problem in carbon based nanostructured materials and devices viz. graphene nanoribbons. The frequency-domain approach is introduced in order to describe a Poisson-Schrödinger / Dirac system in a quasi static framework. Thetime-domain approach deals with the full-wave solution of the combined Maxwell-Schrödinger / Dirac system of equations. From the above theoretical platforms, home-made solvers are provided, aimed atdealing with challenging problems in realistic devices / systems environments, typical of the area of radio-frequency nanoelectronics.

  20. Quasi-one-dimensional Hall physics in the Harper–Hofstadter–Mott model

    Kozarski, Filip; Hügel, Dario; Pollet, Lode

    2018-04-01

    We study the ground-state phase diagram of the strongly interacting Harper–Hofstadter–Mott model at quarter flux on a quasi-one-dimensional lattice consisting of a single magnetic flux quantum in y-direction. In addition to superfluid phases with various density patterns, the ground-state phase diagram features quasi-one-dimensional analogs of fractional quantum Hall phases at fillings ν = 1/2 and 3/2, where the latter is only found thanks to the hopping anisotropy and the quasi-one-dimensional geometry. At integer fillings—where in the full two-dimensional system the ground-state is expected to be gapless—we observe gapped non-degenerate ground-states: at ν = 1 it shows an odd ‘fermionic’ Hall conductance, while the Hall response at ν = 2 consists of the transverse transport of a single particle–hole pair, resulting in a net zero Hall conductance. The results are obtained by exact diagonalization and in the reciprocal mean-field approximation.

  1. Plasmonic photocatalytic reactions enhanced by hot electrons in a one-dimensional quantum well

    H. J. Huang

    2015-11-01

    Full Text Available The plasmonic endothermic oxidation of ammonium ions in a spinning disk reactor resulted in light energy transformation through quantum hot charge carriers (QHC, or quantum hot electrons, during a chemical reaction. It is demonstrated with a simple model that light of various intensities enhance the chemical oxidization of ammonium ions in water. It was further observed that light illumination, which induces the formation of plasmons on a platinum (Pt thin film, provided higher processing efficiency compared with the reaction on a bare glass disk. These induced plasmons generate quantum hot electrons with increasing momentum and energy in the one-dimensional quantum well of a Pt thin film. The energy carried by the quantum hot electrons provided the energy needed to catalyze the chemical reaction. The results indicate that one-dimensional confinement in spherical coordinates (i.e., nanoparticles is not necessary to provide an extra excited state for QHC generation; an 8 nm Pt thin film for one-dimensional confinement in Cartesian coordinates can also provide the extra excited state for the generation of QHC.

  2. Optical Tamm states in one-dimensional superconducting photonic crystal

    El Abouti, O. [LPMR, Département de Physique, Faculté des Sciences, Université Mohammed 1, 60000 Oujda (Morocco); El Boudouti, E. H. [LPMR, Département de Physique, Faculté des Sciences, Université Mohammed 1, 60000 Oujda (Morocco); IEMN, UMR-CNRS 8520, UFR de Physique, Université de Lille 1, 59655 Villeneuve d' Ascq (France); El Hassouani, Y. [ESIM, Département de Physique, Faculté des Sciences et Techniques, Université Moulay Ismail, Boutalamine BP 509, 52000 Errachidia (Morocco); Noual, A. [LPMR, Département de Physique, Faculté des Sciences, Université Mohammed 1, 60000 Oujda (Morocco); Ecole Normale Supérieur de Tétouan, Université Abdelmalek Essaadi, Tétouan (Morocco); Djafari-Rouhani, B. [IEMN, UMR-CNRS 8520, UFR de Physique, Université de Lille 1, 59655 Villeneuve d' Ascq (France)

    2016-08-15

    In this study, we investigate localized and resonant optical waves associated with a semi-infinite superlattice made out of superconductor-dielectric bilayers and terminated with a cap layer. Both transverse electric and transverse magnetic waves are considered. These surface modes are analogous to the so-called Tamm states associated with electronic states found at the surface of materials. The surface guided modes induced by the cap layer strongly depend on whether the superlattice ends with a superconductor or a dielectric layer, the thickness of the surface layer, the temperature of the superconductor layer as well as on the polarization of the waves. Different kinds of surface modes are found and their properties examined. These structures can be used to realize the highly sensitive photonic crystal sensors.

  3. Thermal conductivity engineering of bulk and one-dimensional Si-Ge nanoarchitectures.

    Kandemir, Ali; Ozden, Ayberk; Cagin, Tahir; Sevik, Cem

    2017-01-01

    Various theoretical and experimental methods are utilized to investigate the thermal conductivity of nanostructured materials; this is a critical parameter to increase performance of thermoelectric devices. Among these methods, equilibrium molecular dynamics (EMD) is an accurate technique to predict lattice thermal conductivity. In this study, by means of systematic EMD simulations, thermal conductivity of bulk Si-Ge structures (pristine, alloy and superlattice) and their nanostructured one dimensional forms with square and circular cross-section geometries (asymmetric and symmetric) are calculated for different crystallographic directions. A comprehensive temperature analysis is evaluated for selected structures as well. The results show that one-dimensional structures are superior candidates in terms of their low lattice thermal conductivity and thermal conductivity tunability by nanostructuring, such as by diameter modulation, interface roughness, periodicity and number of interfaces. We find that thermal conductivity decreases with smaller diameters or cross section areas. Furthermore, interface roughness decreases thermal conductivity with a profound impact. Moreover, we predicted that there is a specific periodicity that gives minimum thermal conductivity in symmetric superlattice structures. The decreasing thermal conductivity is due to the reducing phonon movement in the system due to the effect of the number of interfaces that determine regimes of ballistic and wave transport phenomena. In some nanostructures, such as nanowire superlattices, thermal conductivity of the Si/Ge system can be reduced to nearly twice that of an amorphous silicon thermal conductivity. Additionally, it is found that one crystal orientation, [Formula: see text]100[Formula: see text], is better than the [Formula: see text]111[Formula: see text] crystal orientation in one-dimensional and bulk SiGe systems. Our results clearly point out the importance of lattice thermal conductivity

  4. Shell-crossing in quasi-one-dimensional flow

    Rampf, Cornelius; Frisch, Uriel

    2017-10-01

    Blow-up of solutions for the cosmological fluid equations, often dubbed shell-crossing or orbit crossing, denotes the breakdown of the single-stream regime of the cold-dark-matter fluid. At this instant, the velocity becomes multi-valued and the density singular. Shell-crossing is well understood in one dimension (1D), but not in higher dimensions. This paper is about quasi-one-dimensional (Q1D) flow that depends on all three coordinates but differs only slightly from a strictly 1D flow, thereby allowing a perturbative treatment of shell-crossing using the Euler-Poisson equations written in Lagrangian coordinates. The signature of shell-crossing is then just the vanishing of the Jacobian of the Lagrangian map, a regular perturbation problem. In essence, the problem of the first shell-crossing, which is highly singular in Eulerian coordinates, has been desingularized by switching to Lagrangian coordinates, and can then be handled by perturbation theory. Here, all-order recursion relations are obtained for the time-Taylor coefficients of the displacement field, and it is shown that the Taylor series has an infinite radius of convergence. This allows the determination of the time and location of the first shell-crossing, which is generically shown to be taking place earlier than for the unperturbed 1D flow. The time variable used for these statements is not the cosmic time t but the linear growth time τ ˜ t2/3. For simplicity, calculations are restricted to an Einstein-de Sitter universe in the Newtonian approximation, and tailored initial data are used. However it is straightforward to relax these limitations, if needed.

  5. Research on one-dimensional two-phase flow

    Adachi, Hiromichi

    1988-10-01

    In Part I the fundamental form of the hydrodynamic basic equations for a one-dimensional two-phase flow (two-fluid model) is described. Discussions are concentrated on the treatment of phase change inertial force terms in the equations of motion and the author's equations of motion which have a remarkable uniqueness on the following three points. (1) To express force balance of unit mass two-phase fluid instead of that of unit volume two-phase fluid. (2) To pick up the unit existing mass and the unit flowing mass as the unit mass of two-phase fluid. (3) To apply the kinetic energy principle instead of the momentum low in the evaluation of steady inertial force term. In these three, the item (1) is for excluding a part of momentum change or kinetic energy change due to mass change of the examined part of fluid, which is independent of force. The item (2) is not to introduce a phenomenological physical model into the evaluation of phase change inertial force term. And the item (3) is for correctly applying the momentum law taking into account the difference of representative velocities between the main flow fluid (vapor phase or liquid phase) and the phase change part of fluid. In Part II, characteristics of various kinds of high speed two-phase flow are clarified theoretically by the basic equations derived. It is demonstrated that the steam-water two-phase critical flow with violent flashing and the airwater two-phase critical flow without phase change can be described with fundamentally the same basic equations. Furthermore, by comparing the experimental data from the two-phase critical discharge test and the theoretical prediction, the two-phase discharge coefficient, C D , for large sharp-edged orifice is determined as the value which is not affected by the experimental facility characteristics, etc. (author)

  6. Fractal spectra in generalized Fibonacci one-dimensional magnonic quasicrystals

    Costa, C.H.O. [Departamento de Fisica Teorica e Experimental, Universidade Federal do Rio grande do Norte, 59072-970 Natal-RN (Brazil); Vasconcelos, M.S., E-mail: manoelvasconcelos@yahoo.com.br [Escola de Ciencias e Tecnologia, Universidade Federal do Rio grande do Norte, 59072-970 Natal-RN (Brazil); Barbosa, P.H.R.; Barbosa Filho, F.F. [Departamento de Fisica, Universidade Federal do Piaui, 64049-550 Teresina-Pi (Brazil)

    2012-07-15

    In this work we carry out a theoretical analysis of the spectra of magnons in quasiperiodic magnonic crystals arranged in accordance with generalized Fibonacci sequences in the exchange regime, by using a model based on a transfer-matrix method together random-phase approximation (RPA). The generalized Fibonacci sequences are characterized by an irrational parameter {sigma}(p,q), which rules the physical properties of the system. We discussed the magnonic fractal spectra for first three generalizations, i.e., silver, bronze and nickel mean. By varying the generation number, we have found that the fragmentation process of allowed bands makes possible the emergence of new allowed magnonic bulk bands in spectra regions that were magnonic band gaps before, such as which occurs in doped semiconductor devices. This interesting property arises in one-dimensional magnonic quasicrystals fabricated in accordance to quasiperiodic sequences, without the need to introduce some deferent atomic layer or defect in the system. We also make a qualitative and quantitative investigations on these magnonic spectra by analyzing the distribution and magnitude of allowed bulk bands in function of the generalized Fibonacci number F{sub n} and as well as how they scale as a function of the number of generations of the sequences, respectively. - Highlights: Black-Right-Pointing-Pointer Quasiperiodic magnonic crystals are arranged in accordance with the generalized Fibonacci sequence. Black-Right-Pointing-Pointer Heisenberg model in exchange regime is applied. Black-Right-Pointing-Pointer We use a theoretical model based on a transfer-matrix method together random-phase approximation. Black-Right-Pointing-Pointer Fractal spectra are characterized. Black-Right-Pointing-Pointer We analyze the distribution of allowed bulk bands in function of the generalized Fibonacci number.

  7. Coulomb blockade threshold in finite one-dimensional arrays of small tunnel junctions

    Lien, Nguyen V.; Dat, Nguyen T.; Nam, Nguyen H.

    2001-11-01

    The current-voltage characteristics of one-dimensional tunnel junction arrays are simulated using the semiclassical and full capacitance matrix description. The threshold voltage V th of the Coulomb blockade (CB) is evaluated and analyzed in detail as a function of the gate capacitance C 0 , the array length N, the temperature, and the degree of disorder. The disordered effect is found to be essential, while the long range interaction included in the full capacitance matrix calculations, when decreasing V th , weakly affects the qualitative behaviour of the CB for the V th (C 0 ) - and the V th (N)-dependences. (author)

  8. Full-Wave Ambient Noise Tomography of the Long Valley Volcanic Region (California)

    Flinders, A. F.; Shelly, D. R.; Dawson, P. B.; Hill, D. P.; Shen, Y.

    2017-12-01

    In the late 1970s, and throughout the 1990s, Long Valley Caldera (California) experienced intense periods of unrest characterized by uplift of the resurgent dome, earthquake swarms, and CO2 emissions around Mammoth Mountain. While modeling of the uplift and gravity changes support the possibility of new magmatic intrusions beneath the caldera, geologic interpretations conclude that the magmatic system underlying the caldera is moribund. Geophysical studies yield diverse versions of a sizable but poorly resolved low-velocity zone at depth (> 6km), yet whether this zone is indicative of a significant volume of crystal mush, smaller isolated pockets of partial melt, or magmatic fluids, is inconclusive. The nature of this low-velocity zone, and the state of volcano's magmatic system, carry important implications for the significance of resurgent-dome inflation and the nature of associated hazards. To better characterize this low-velocity zone we present preliminary results from a 3D full-waveform ambient-noise seismic tomography model derived from the past 25 years of vertical component broadband and short-period seismic data. This new study uses fully numerical solutions of the wave equation to account for the complex wave propagation in a heterogeneous, 3D earth model, including wave interaction with topography. The method ensures that wave propagation is modeled accurately in 3D, enabling the full use of seismic records. By using empirical Green's functions, derived from ambient noise and modeled as Rayleigh surface waves, we are able to extend model resolution to depths beyond the limits of previous local earthquake studies. The model encompasses not only the Long Valley Caldera, but the entire Long Valley Volcanic Region, including Mammoth Mountain and the Mono Crater/Inyo Domes volcanic chain.

  9. Quasi-Resonant Full-Wave Zero-Current Switching Buck Converter Design, Simulation and Application

    Yanik, G.; Isen, E.

    2015-01-01

    —This paper presents a full wave quasi-resonant zerocurrent switching buck converter design, simulation and application. The converter control uses with zero-current switching (ZCS) technique to decrease the switching losses. Comparing to conventional buck converter, resonant buck converter includes a resonant tank equipped with resonant inductor and capacitor. The converter is analyzed in mathematical for each subintervals. Depending on the desired input and output electrical quantities, con...

  10. Expectation-based approach for one-dimensional randomly disordered phononic crystals

    Wu, Feng; Gao, Qiang; Xu, Xiaoming; Zhong, Wanxie

    2014-01-01

    An expectation-based approach to the statistical theorem is proposed for the one-dimensional randomly disordered phononic crystal. In the proposed approach, the expectations of the random eigenstates of randomly disordered phononic crystals are investigated. In terms of the expectations of the random eigenstates, the wave propagation and localization phenomenon in the random phononic crystal could be understood in a statistical perspective. Using the proposed approach, it is proved that for a randomly disordered phononic crystal, the Bloch theorem holds in the perspective of expectation. A one-dimensional randomly disordered binary phononic crystal consisting of two materials with the random geometry size or random physical parameter is addressed by using the proposed approach. From the result, it can be observed that with the increase of the disorder degree, the localization of the expectations of the eigenstates is strengthened. The effect of the random disorder on the eigenstates at higher frequencies is more significant than that at lower frequencies. Furthermore, after introducing the random disorder into phononic crystals, some random divergent eigenstates are changed to localized eigenstates in expectation sense.

  11. One-dimensional cuts through multidimensional potential-energy surfaces by tunable x rays

    Eckert, Sebastian; da Cruz, Vinícius Vaz; Gel'mukhanov, Faris; Ertan, Emelie; Ignatova, Nina; Polyutov, Sergey; Couto, Rafael C.; Fondell, Mattis; Dantz, Marcus; Kennedy, Brian; Schmitt, Thorsten; Pietzsch, Annette; Odelius, Michael; Föhlisch, Alexander

    2018-05-01

    The concept of the potential-energy surface (PES) and directional reaction coordinates is the backbone of our description of chemical reaction mechanisms. Although the eigenenergies of the nuclear Hamiltonian uniquely link a PES to its spectrum, this information is in general experimentally inaccessible in large polyatomic systems. This is due to (near) degenerate rovibrational levels across the parameter space of all degrees of freedom, which effectively forms a pseudospectrum given by the centers of gravity of groups of close-lying vibrational levels. We show here that resonant inelastic x-ray scattering (RIXS) constitutes an ideal probe for revealing one-dimensional cuts through the ground-state PES of molecular systems, even far away from the equilibrium geometry, where the independent-mode picture is broken. We strictly link the center of gravity of close-lying vibrational peaks in RIXS to a pseudospectrum which is shown to coincide with the eigenvalues of an effective one-dimensional Hamiltonian along the propagation coordinate of the core-excited wave packet. This concept, combined with directional and site selectivity of the core-excited states, allows us to experimentally extract cuts through the ground-state PES along three complementary directions for the showcase H2O molecule.

  12. Full Waveform Inversion of Diving & Reflected Waves based on Scale Separation for Velocity and Impedance Imaging

    Brossier, Romain; Zhou, Wei; Operto, Stéphane; Virieux, Jean

    2015-04-01

    Full Waveform Inversion (FWI) is an appealing method for quantitative high-resolution subsurface imaging (Virieux et al., 2009). For crustal-scales exploration from surface seismic, FWI generally succeeds in recovering a broadband of wavenumbers in the shallow part of the targeted medium taking advantage of the broad scattering-angle provided by both reflected and diving waves. In contrast, deeper targets are often only illuminated by short-spread reflections, which favor the reconstruction of the short wavelengths at the expense of the longer ones, leading to a possible notch in the intermediate part of the wavenumber spectrum. To update the velocity macromodel from reflection data, image-domain strategies (e.g., Symes & Carazzone, 1991) aim to maximize a semblance criterion in the migrated domain. Alternatively, recent data-domain strategies (e.g., Xu et al., 2012, Ma & Hale, 2013, Brossier et al., 2014), called Reflection FWI (RFWI), inspired by Chavent et al. (1994), rely on a scale separation between the velocity macromodel and prior knowledge of the reflectivity to emphasize the transmission regime in the sensitivity kernel of the inversion. However, all these strategies focus on reflected waves only, discarding the low-wavenumber information carried out by diving waves. With the current development of very long-offset and wide-azimuth acquisitions, a significant part of the recorded energy is provided by diving waves and subcritical reflections, and high-resolution tomographic methods should take advantage of all types of waves. In this presentation, we will first review the issues of classical FWI when applied to reflected waves and how RFWI is able to retrieve the long wavelength of the model. We then propose a unified formulation of FWI (Zhou et al., 2014) to update the low wavenumbers of the velocity model by the joint inversion of diving and reflected arrivals, while the impedance model is updated thanks to reflected wave only. An alternate inversion of

  13. Ion cyclotron emission calculations using a 2D full wave numerical code

    Batchelor, D.B.; Jaeger, E.F.; Colestock, P.L.

    1987-01-01

    Measurement of radiation in the HF band due to cyclotron emission by energetic ions produced by fusion reactions or neutral beam injection promises to be a useful diagnostic on large devices which are entering the reactor regime of operation. A number of complications make the modelling and interpretation of such measurements difficult using conventional geometrical optics methods. In particular the long wavelength and lack of high directivity of antennas in this frequency regime make observation of a single path across the plasma into a viewing dump impractical. Pickup antennas effectively see the whole plasma and wall reflection effects are important. We have modified our 2D full wave ICRH code 2 to calculate wave fields due to a distribution of energetic ions in tokamak geometry. The radiation is modeled as due to an ensemble of localized source currents distributed in space. The spatial structure of the coherent wave field is then calculated including cyclotron harmonic damping as compared to the usual procedure of incoherently summing powers of individual radiators. This method has the advantage that phase information from localized radiating currents is globally retained so the directivity of the pickup antennas is correctly represented. Also standing waves and wall reflections are automatically included

  14. One-Dimensional Hetero-Nanostructures for Rechargeable Batteries.

    Mai, Liqiang; Sheng, Jinzhi; Xu, Lin; Tan, Shuangshuang; Meng, Jiashen

    2018-04-17

    Rechargeable batteries are regarded as one of the most practical electrochemical energy storage devices that are able to convert and store the electrical energy generated from renewable resources, and they function as the key power sources for electric vehicles and portable electronics. The ultimate goals for electrochemical energy storage devices are high power and energy density, long lifetime, and high safety. To achieve the above goals, researchers have tried to apply various morphologies of nanomaterials as the electrodes to enhance the electrochemical performance. Among them, one-dimensional (1D) materials show unique superiorities, such as cross-linked structures for external stress buffering and large draw ratios for internal stress dispersion. However, a homogeneous single-component electrode material can hardly have the characteristics of high electronic/ionic conductivity and high stability in the electrochemical environment simultaneously. Therefore, designing well-defined functional 1D hetero-nanostructures that combine the advantages and overcome the limitations of different electrochemically active materials is of great significance. This Account summarizes fabrication strategies for 1D hetero-nanostructures, including nucleation and growth, deposition, and melt-casting and electrospinning. Besides, the chemical principles for each strategy are discussed. The nucleation and growth strategy is suitable for growing and constructing 1D hetero-nanostructures of partial transition metal compounds, and the experimental conditions for this strategy are relatively accessible. Deposition is a reliable strategy to synthesize 1D hetero-nanostructures by decorating functional layers on 1D substrate materials, on the condition that the preobtained substrate materials must be stable in the following deposition process. The melt-casting strategy, in which 1D hetero-nanostructures are synthesizes via a melting and molding process, is also widely used. Additionally

  15. Bioinspired one-dimensional materials for directional liquid transport.

    Ju, Jie; Zheng, Yongmei; Jiang, Lei

    2014-08-19

    One-dimensional materials (1D) capable of transporting liquid droplets directionally, such as spider silks and cactus spines, have recently been gathering scientists' attention due to their potential applications in microfluidics, textile dyeing, filtration, and smog removal. This remarkable property comes from the arrangement of the micro- and nanostructures on these organisms' surfaces, which have inspired chemists to develop methods to prepare surfaces with similar directional liquid transport ability. In this Account, we report our recent progress in understanding how this directional transport works, as well our advances in the design and fabrication of bioinspired 1D materials capable of transporting liquid droplets directionally. To begin, we first discuss some basic theories on droplet directional movement. Then, we discuss the mechanism of directional transport of water droplets on natural spider silks. Upon contact with water droplets, the spider silk undergoes what is known as a wet-rebuilt, which forms periodic spindle-knots and joints. We found that the resulting gradient of Laplace pressure and surface free energy between the spindle-knots and joints account for the cooperative driving forces to transport water droplets directionally. Next, we discuss the directional transport of water droplets on desert cactus. The integration of multilevel structures of the cactus and the resulting integration of multiple functions together allow the cactus spine to transport water droplets continuously from tip to base. Based on our studies of natural spider silks and cactus spines, we have prepared a series of artificial spider silks (A-SSs) and artificial cactus spines (A-CSs) with various methods. By changing the surface roughness and chemical compositions of the artificial spider silks' spindle-knots, or by introducing stimulus-responsive molecules, such as thermal-responsive and photoresponsive molecules, onto the spindle-knots, we can reversibly manipulate

  16. Universal Voltage Conveyor and Current Conveyor in Fast Full-Wave Rectifier

    Josef Burian

    2012-12-01

    Full Text Available This paper deals about the design of a fast voltage-mode full-wave rectifier, where universal voltage conveyor and second-generation current conveyor are used as active elements. Thanks to the active elements, the input and output impedance of the non-linear circuit is infinitely high respectively zero in theory. For the rectification only two diodes and three resistors are required as passive elements. The performance of the circuit is shown on experimental measurement results showing the dynamic range, time response, frequency dependent DC transient value and RMS error for different values of input voltage amplitudes.

  17. Current and Voltage Conveyors in Current- and Voltage-Mode Precision Full-Wave Rectifiers

    J. Koton

    2011-04-01

    Full Text Available In this paper new versatile precision full-wave rectifiers using current and/or voltage conveyors as active elements and two diodes are presented. The performance of these circuit solutions is analysed and compared to the opamp based precision rectifier. To analyze the behavior of the functional blocks, the frequency dependent RMS error and DC transient value are evaluated for different values of input voltage amplitudes. Furthermore, experimental results are given that show the feasibilities of the conveyor based rectifiers superior to the corresponding operational amplifier based topology.

  18. Visco-elastic controlled-source full waveform inversion without surface waves

    Paschke, Marco; Krause, Martin; Bleibinhaus, Florian

    2016-04-01

    We developed a frequency-domain visco-elastic full waveform inversion for onshore seismic experiments with topography. The forward modeling is based on a finite-difference time-domain algorithm by Robertsson that uses the image-method to ensure a stress-free condition at the surface. The time-domain data is Fourier-transformed at every point in the model space during the forward modeling for a given set of frequencies. The motivation for this approach is the reduced amount of memory when computing kernels, and the straightforward implementation of the multiscale approach. For the inversion, we calculate the Frechet derivative matrix explicitly, and we implement a Levenberg-Marquardt scheme that allows for computing the resolution matrix. To reduce the size of the Frechet derivative matrix, and to stabilize the inversion, an adapted inverse mesh is used. The node spacing is controlled by the velocity distribution and the chosen frequencies. To focus the inversion on body waves (P, P-coda, and S) we mute the surface waves from the data. Consistent spatiotemporal weighting factors are applied to the wavefields during the Fourier transform to obtain the corresponding kernels. We test our code with a synthetic study using the Marmousi model with arbitrary topography. This study also demonstrates the importance of topography and muting surface waves in controlled-source full waveform inversion.

  19. Full-wave Simulation of Doppler Reflectometry in the Presence of Turbulence

    Lechte, C. [Institut fur Plasmaforschung, Universitat Stuttgart, Stuttgart (Germany)

    2011-07-01

    Doppler reflectometry is a microwave plasma diagnostic well suited for density fluctuation measurement. A meaningful interpretation of Doppler reflectometry measurements necessitates the analysis of the wave propagation in the plasma using simulations methods. While the beam path can usually be reconstructed with beam tracing methods, the modeling of the scattering process demands the use of wave simulation codes. Furthermore, in the presence of strong density fluctuations, the response from the plasma is dominated by dispersion and multiple scattering, and hence becomes non-linear. IPF-FD3D is the finite difference time domain code used to investigate the dependence of the scattering efficiency on the various plasma conditions. It uses the full set of Maxwell equations and the electron equation of motion in a cold plasma. First results in slab geometry indicate a strong dependence of the scattering efficiency on the density gradient, the incident angle, and the wave polarisation. Further complications arise with the introduction of broadband turbulent fluctuations, where additional knowledge of the radial spectrum is necessary to reconstruct the full fluctuation spectrum from Doppler reflectometry measurements. This paper presents the reconstruction of the turbulent fluctuation spectrum from simulated Doppler reflectometry measurements in slab geometry. Two cases of analytical turbulence in slab geometry are presented where the fluctuation wavenumber spectrum was recovered. It is planned to extend these investigations to X mode polarization and to supplement actual fusion experiments

  20. Defects in quasi-one dimensional oxide conductors: K0.3MoO3

    Smith, K.E.; Breuer, K.; Goldberg, D.; Greenblatt, M.; McCarroll, W.; Hulbert, S.L.

    1995-01-01

    The electronic structure of the prototypical quasi-one dimensional (ID) conductor K 0.3 MoO 3 has been studied using high resolution photoemission spectroscopy. In particular, the electronic structure of defects was investigated in order to understand the mechanism for charge density wave pinning and destruction of the Peierls transition. Defects were found to radically alter the electronic structure close to the Fermi level (E F ), thus strongly modifying the structure of the Fermi surface. While a low emission intensity at E F has been interpreted as evidence for a Luttinger liquid ground state in a 1D metal, the authors show that non-stoichiometric surfaces lead to similar effects. The nature of the ground state is discussed in the context of these results

  1. A novel technique for one-dimensional scattering from Dirac Comb

    Taya, Sofyan A.; Shabat, M.M.

    2001-08-01

    Using the well-known matrix formulation of the reflection and transmission of electromagnetic waves by a stratified planner structure, we show that the reflection and transmission coefficients of any number of isotropic media can be written by a simple general formula. This formula uses the so-called elementary symmetric functions that are extensively used in the mathematical theory of polynomials. The approach is then applied to the quantum scattering. We show that the reflection and transmission coefficients of any number of quantum wells or barriers can be written in the similar way. Finally, one-dimensional scattering from a series of delta-function barriers (a system that is called Dirac Comb) is studied. The computed numerical illustrations compared with the earlier results based on the transfer matrix and Chebychev polynomials reveal an excellent agreement. (author)

  2. One-dimensional, forward-forward mean-field games with congestion

    Gomes, Diogo A.

    2017-03-29

    Here, we consider one-dimensional forward-forward mean-field games (MFGs) with congestion, which were introduced to approximate stationary MFGs. We use methods from the theory of conservation laws to examine the qualitative properties of these games. First, by computing Riemann invariants and corresponding invariant regions, we develop a method to prove lower bounds for the density. Next, by combining the lower bound with an entropy function, we prove the existence of global solutions for parabolic forward-forward MFGs. Finally, we construct traveling-wave solutions, which settles in a negative way the convergence problem for forward-forward MFGs. A similar technique gives the existence of time-periodic solutions for non-monotonic MFGs.

  3. Application of nonlinear models to estimate the gain of one-dimensional free-electron lasers

    Peter, E.; Rizzato, F. B.; Endler, A.

    2017-06-01

    In the present work, we make use of simplified nonlinear models based on the compressibility factor (Peter et al., Phys. Plasmas, vol. 20 (12), 2013, 123104) to predict the gain of one-dimensional (1-D) free-electron lasers (FELs), considering space-charge and thermal effects. These models proved to be reasonable to estimate some aspects of 1-D FEL theory, such as the position of the onset of mixing, in the case of a initially cold electron beam, and the position of the breakdown of the laminar regime, in the case of an initially warm beam (Peter et al., Phys. Plasmas, vol. 21 (11), 2014, 113104). The results given by the models are compared to wave-particle simulations showing a reasonable agreement.

  4. Non-equilibrium coherence dynamics in one-dimensional Bose gases

    Hofferberth, S.; Lesanovsky, Igor; Fischer, B.

    2007-01-01

    Low-dimensional systems provide beautiful examples of many-body quantum physics. For one-dimensional (1D) systems, the Luttinger liquid approach provides insight into universal properties. Much is known of the equilibrium state, both in the weakly and strongly interacting regimes. However......, the coherence factor is observed to approach a non-zero equilibrium value, as predicted by a Bogoliubov approach. This coupled-system decay to finite coherence is the matter wave equivalent of phase-locking two lasers by injection. The non-equilibrium dynamics of superfluids has an important role in a wide...... range of physical systems, such as superconductors, quantum Hall systems, superfluid helium and spin systems. Our experiments studying coherence dynamics show that 1D Bose gases are ideally suited for investigating this class of phenomena....

  5. One-Dimensional Signal Extraction Of Paper-Written ECG Image And Its Archiving

    Zhang, Zhi-ni; Zhang, Hong; Zhuang, Tian-ge

    1987-10-01

    A method for converting paper-written electrocardiograms to one dimensional (1-D) signals for archival storage on floppy disk is presented here. Appropriate image processing techniques were employed to remove the back-ground noise inherent to ECG recorder charts and to reconstruct the ECG waveform. The entire process consists of (1) digitization of paper-written ECGs with an image processing system via a TV camera; (2) image preprocessing, including histogram filtering and binary image generation; (3) ECG feature extraction and ECG wave tracing, and (4) transmission of the processed ECG data to IBM-PC compatible floppy disks for storage and retrieval. The algorithms employed here may also be used in the recognition of paper-written EEG or EMG and may be useful in robotic vision.

  6. Verification of the validity of the short-pulse approximation for one-dimensional Rydberg atoms

    Kopyciuk, T; Grajek, M

    2011-01-01

    In this paper, we investigate the short-pulse approximation (SPA) for one-dimensional Rydberg atoms. We analyse the limits that SPA has to fulfil in order to be applicable. These concern the shape, the duration and the displacement caused by the pulse. The correctness of SPA is tested by comparing the results obtained using SPA with a numerical solution of the set of time-dependent Schroedinger equations. We show that the limit for the displacement caused by the pulse is of greatest importance. Violation of the limit for the duration of the pulse is shown to lead to concurrent violation of the limit for the displacement. We also show that the shape of the pulse has no influence on the created wave packet.

  7. Full-waveform inversion with reflected waves for 2D VTI media

    Pattnaik, Sonali

    2016-09-06

    Full-waveform inversion in anisotropic media using reflected waves suffers from the strong non-linearity of the objective function and trade-offs between model parameters. Estimating long-wavelength model components by fixing parameter perturbations, referred to as reflection-waveform inversion (RWI), can mitigate nonlinearity-related inversion issues. Here, we extend RWI to acoustic VTI (transversely isotropic with a vertical symmetry axis) media. To minimize trade-offs between the model parameters, we employ a new hierarchical two-stage approach that operates with the P-wave normal-moveout velocity and anisotropy coefficents ζ and η. First, is estimated using a fixed perturbation in ζ, and then we invert for η by fixing the updated perturbation in . The proposed 2D algorithm is tested on a horizontally layered VTI model.

  8. Calculation of the Full Scattering Amplitude without Partial Wave Decomposition II: Inclusion of Exchange

    Shertzer, Janine; Temkin, A.

    2003-01-01

    As is well known, the full scattering amplitude can be expressed as an integral involving the complete scattering wave function. We have shown that the integral can be simplified and used in a practical way. Initial application to electron-hydrogen scattering without exchange was highly successful. The Schrodinger equation (SE), which can be reduced to a 2d partial differential equation (pde), was solved using the finite element method. We have now included exchange by solving the resultant SE, in the static exchange approximation, which is reducible to a pair of coupled pde's. The resultant scattering amplitudes, both singlet and triplet, calculated as a function of energy are in excellent agreement with converged partial wave results.

  9. Calculation of the Full Scattering Amplitude without Partial Wave Decomposition II

    Shertzer, J.; Temkin, A.

    2003-01-01

    As is well known, the full scattering amplitude can be expressed as an integral involving the complete scattering wave function. We have shown that the integral can be simplified and used in a practical way. Initial application to electron-hydrogen scattering without exchange was highly successful. The Schrodinger equation (SE) can be reduced to a 2d partial differential equation (pde), and was solved using the finite element method. We have now included exchange by solving the resultant SE, in the static exchange approximation. The resultant equation can be reduced to a pair of coupled pde's, to which the finite element method can still be applied. The resultant scattering amplitudes, both singlet and triplet, as a function of angle can be calculated for various energies. The results are in excellent agreement with converged partial wave results.

  10. Two-dimensional full-wave code for reflectometry simulations in TJ-II

    Blanco, E.; Heuraux, S.; Estrada, T.; Sanchez, J.; Cupido, L.

    2004-01-01

    A two-dimensional full-wave code in the extraordinary mode has been developed to simulate reflectometry in TJ-II. The code allows us to study the measurement capabilities of the future correlation reflectometer that is being installed in TJ-II. The code uses the finite-difference-time-domain technique to solve Maxwell's equations in the presence of density fluctuations. Boundary conditions are implemented by a perfectly matched layer to simulate free propagation. To assure the stability of the code, the current equations are solved by a fourth-order Runge-Kutta method. Density fluctuation parameters such as fluctuation level, wave numbers, and correlation lengths are extrapolated from those measured at the plasma edge using Langmuir probes. In addition, realistic plasma shape, density profile, magnetic configuration, and experimental setup of TJ-II are included to determine the plasma regimes in which accurate information may be obtained

  11. Full-wave modeling of the O-X mode conversion in the Pegasus toroidal experiment

    Koehn, A. [Institut fuer Plasmaforschung, Universitaet Stuttgart, D-70569 (Germany); Jacquot, J. [IRFM, CEA, F-13108 Saint-Paul-lez-Durance (France); Bongard, M. W.; Hinson, E. T.; Volpe, F. A. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Gallian, S. [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2011-08-15

    The ordinary-extraordinary (O-X) mode conversion is modeled with the aid of a 2D full-wave code in the Pegasus toroidal experiment as a function of the launch angles. It is shown how the shape of the plasma density profile in front of the antenna can significantly influence the mode conversion efficiency and, thus, the generation of electron Bernstein waves (EBWs). It is therefore desirable to control the density profile in front of the antenna for successful operation of an EBW heating and current drive system. On the other hand, the conversion efficiency is shown to be resilient to vertical displacements of the plasma as large as {+-}10 cm.

  12. Extension of One-Dimensional Models for Hyperelastic String Structures under Coulomb Friction with Adhesion

    Vladimir Shiryaev

    2018-04-01

    Full Text Available A stretching behavior of knitted and woven textiles is modeled. In our work, the yarns are modeled as one-dimensional hyperelastic strings with frictional contact. Capstan law known for Coulomb’s friction of yarns is extended to an additional adhesion due to gluing of filaments on the yarn surface or some chemical reaction. Two-step Newton’s method is applied for the solution of the large stretching with sliding evolution in the contact nodes. The approach is illustrated on a hysteresis of knitted textile and on the force-strain curve for a woven pattern and both compared with experimental effective curves.

  13. Hierarchical one-dimensional ammonium nickel phosphate microrods for high-performance pseudocapacitors

    Raju, K

    2015-12-01

    Full Text Available :17629 | DOI: 10.1038/srep17629 www.nature.com/scientificreports Hierarchical One-Dimensional Ammonium Nickel Phosphate Microrods for High-Performance Pseudocapacitors Kumar Raju1 & Kenneth I. Ozoemena1,2 High-performance electrochemical capacitors... OPEN w w w . n a t u r e . c o m / s c i e n t i f i c r e p o r t s / 2S C I E N T I F I C REPORTS | 5:17629 | DOI: 10.1038/srep17629 Hierarchical 1-D and 2-D materials maximize the supercapacitive properties due to their unique ability to permit ion...

  14. Quantum quench dynamics of the attractive one-dimensional Bose gas via the coordinate Bethe ansatz

    Jan C. Zill, Tod M. Wright, Karen V. Kheruntsyan, Thomas Gasenzer, Matthew J. Davis

    2018-02-01

    Full Text Available We use the coordinate Bethe ansatz to study the Lieb-Liniger model of a one-dimensional gas of bosons on a finite-sized ring interacting via an attractive delta-function potential. We calculate zero-temperature correlation functions for seven particles in the vicinity of the crossover to a localized solitonic state and study the dynamics of a system of four particles quenched to attractive interactions from the ideal-gas ground state. We determine the time evolution of correlation functions, as well as their temporal averages, and discuss the role of bound states in shaping the postquench correlations and relaxation dynamics.

  15. Double ionization in Helium. Ab initio calculations beyond the one dimensional approximation

    Camilo Ruiz; Luis Plaja; Luis Roso; Andreas Becker

    2006-01-01

    Complete test of publication follows. We present ab-initio computations of the ionization of two-electron atoms by short pulses of coherent radiation beyond the one-dimensional approximation. In the model the electron correlation is included in its full dimensionality, while the center-of-mass motion is restricted along the polarization axis. We show some result for Non Sequential Double Ionization (NSDI) as well as for SDI for high intensity low IR frequency. Some recent applications for this correlated system is also presented.

  16. Electric Field Guided Assembly of One-Dimensional Nanostructures for High Performance Sensors

    Wing Kam Liu

    2012-05-01

    Full Text Available Various nanowire or nanotube-based devices have been demonstrated to fulfill the anticipated future demands on sensors. To fabricate such devices, electric field-based methods have demonstrated a great potential to integrate one-dimensional nanostructures into various forms. This review paper discusses theoretical and experimental aspects of the working principles, the assembled structures, and the unique functions associated with electric field-based assembly. The challenges and opportunities of the assembly methods are addressed in conjunction with future directions toward high performance sensors.

  17. Classical Lie Point Symmetry Analysis of a Steady Nonlinear One-Dimensional Fin Problem

    R. J. Moitsheki

    2012-01-01

    Full Text Available We consider the one-dimensional steady fin problem with the Dirichlet boundary condition at one end and the Neumann boundary condition at the other. Both the thermal conductivity and the heat transfer coefficient are given as arbitrary functions of temperature. We perform preliminary group classification to determine forms of the arbitrary functions appearing in the considered equation for which the principal Lie algebra is extended. Some invariant solutions are constructed. The effects of thermogeometric fin parameter and the exponent on temperature are studied. Also, the fin efficiency is analyzed.

  18. Electrically Rotatable Polarizer Using One-Dimensional Photonic Crystal with a Nematic Liquid Crystal Defect Layer

    Ryotaro Ozaki

    2015-09-01

    Full Text Available Polarization characteristics of defect mode peaks in a one-dimensional (1D photonic crystal (PC with a nematic liquid crystal (NLC defect layer have been investigated. Two different polarized defect modes are observed in a stop band. One group of defect modes is polarized along the long molecular axis of the NLC, whereas another group is polarized along its short axis. Polarizations of the defect modes can be tuned by field-induced in-plane reorientation of the NLC in the defect layer. The polarization properties of the 1D PC with the NLC defect layer is also investigated by the finite difference time domain (FDTD simulation.

  19. A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

    Kibbey, Timothy P.

    2014-01-01

    A derivation of turbulent flow parameters, combined with data from erosive burning test motors and blowing wall tests results in erosive burning model candidates useful in one-dimensional internal ballistics analysis capable of scaling across wide ranges of motor size. The real-time burn rate data comes from three test campaigns of subscale segmented solid rocket motors tested at two facilities. The flow theory admits the important effect of the blowing wall on the turbulent friction coefficient by using blowing wall data to determine the blowing wall friction coefficient. The erosive burning behavior of full-scale motors is now predicted more closely than with other recent models.

  20. Variational model for one-dimensional quantum magnets

    Kudasov, Yu. B.; Kozabaranov, R. V.

    2018-04-01

    A new variational technique for investigation of the ground state and correlation functions in 1D quantum magnets is proposed. A spin Hamiltonian is reduced to a fermionic representation by the Jordan-Wigner transformation. The ground state is described by a new non-local trial wave function, and the total energy is calculated in an analytic form as a function of two variational parameters. This approach is demonstrated with an example of the XXZ-chain of spin-1/2 under a staggered magnetic field. Generalizations and applications of the variational technique for low-dimensional magnetic systems are discussed.

  1. One-dimensional map lattices: Synchronization, bifurcations, and chaotic structures

    Belykh, Vladimir N.; Mosekilde, Erik

    1996-01-01

    The paper presents a qualitative analysis of coupled map lattices (CMLs) for the case of arbitrary nonlinearity of the local map and with space-shift as well as diffusion coupling. The effect of synchronization where, independently of the initial conditions, all elements of a CML acquire uniform...... dynamics is investigated and stable chaotic time behaviors, steady structures, and traveling waves are described. Finally, the bifurcations occurring under the transition from spatiotemporal chaos to chaotic synchronization and the peculiarities of CMLs with specific symmetries are discussed....

  2. One-dimensional scattering problem for inverse square potential

    Mineev, V.S.

    1990-01-01

    Analytical continuation of the solution for the Schroedinger equation of inverse square potential, together with the modified method for variation of constants makes it possible to construct admittable self-adjoint extensions and to completely analyze the respective scattering problem along the entire line. In this case, the current density conservation and the wave function continuity when passing through the singular point x=0 require, that a 8-shaped induced potential should be introduced in the Schroedinger equation. The relevant calculations have shown that the potential x -2 can be either absolutely penetrable or absolutely impenetrable. 16 refs

  3. Numerical solution of multigroup diffuse equations of one-dimensional geometry

    Pavelesku, M.; Adam, S.

    1975-01-01

    The one-dimensional diffuse theory is used for reactor physics calculations of fast reactors. Computer program based on the one-dimensional diffuse theory is speedy and not memory consuming. The algorithm is described for the three-zone fast reactor criticality computation in one-dimensional diffusion approximation. This algorithm is realised on IBM 370/135 computer. (I.T.)

  4. Study on the properties of tunable prohibited band gaps for one-dimensional ternary magnetized plasma photonic crystals

    Zhang Haifeng; Zheng Jianping; Zhu Rongjun

    2012-01-01

    The transfer matrix method was applied to study on the properties of tunable prohibited band gaps for one-dimensional ternary magnetized plasma photonic crystals with TE wave arbitrary incident under ideal conditions. TE wave would be divided into left-handed circularly polarized wave and right-handed circularly polarized wave after propagation through one-dimensional ternary magnetized plasma photonic crystals. The calculated transmission coefficients were used to analyze the effects of parameter of plasma, plasma filling factor, incident angle and relative dielectric constant for dielectric layer on the properties of tunable prohibited band gap. The results illustrate that the width of band gaps can not be broadened by increasing plasma collision frequency, the numbers and width of band gaps can be tuned by changing plasma frequency, plasma filling factor and relative dielectric constant for dielectric layer. The band gaps for right-handed circularly polarized wave can be tuned by the plasma gyro frequency, but band gaps for the left-handed circularly polarized wave can't influenced. Low-frequency region of band gaps will be broadened, while high-frequency region of band gaps will be firstly narrow and then broaden with increasing incident angle. (authors)

  5. Electromagnetic backscattering from one-dimensional drifting fractal sea surface II: Electromagnetic backscattering model

    Xie Tao; Zhao Shang-Zhuo; Fang He; Yu Wen-Jin; He Yi-Jun; Perrie, William

    2016-01-01

    Sea surface current has a significant influence on electromagnetic (EM) backscattering signals and may constitute a dominant synthetic aperture radar (SAR) imaging mechanism. An effective EM backscattering model for a one-dimensional drifting fractal sea surface is presented in this paper. This model is used to simulate EM backscattering signals from the drifting sea surface. Numerical results show that ocean currents have a significant influence on EM backscattering signals from the sea surface. The normalized radar cross section (NRCS) discrepancies between the model for a coupled wave-current fractal sea surface and the model for an uncoupled fractal sea surface increase with the increase of incidence angle, as well as with increasing ocean currents. Ocean currents that are parallel to the direction of the wave can weaken the EM backscattering signal intensity, while the EM backscattering signal is intensified by ocean currents propagating oppositely to the wave direction. The model presented in this paper can be used to study the SAR imaging mechanism for a drifting sea surface. (paper)

  6. Phononic crystals with one-dimensional defect as sensor materials

    Aly, Arafa H.; Mehaney, Ahmed

    2017-09-01

    Recently, sensor technology has attracted great attention in many fields due to its importance in many engineering applications. In the present work, we introduce a study using the innovative properties of phononic crystals in enhancing a new type of sensors based on the intensity of transmitted frequencies inside the phononic band gaps. Based on the transfer matrix method and Bloch theory, the expressions of the reflection coefficient and dispersion relation are presented. Firstly, the influences of filling fraction ratio and the angle of incidence on the band gap width are discussed. Secondly, the localization of waves inside band gaps is discussed by enhancing the properties of the defected phononic crystal. Compared to the periodic structure, localization modes involved within the band structure of phononic crystals with one and two defect layers are presented and compared. Trapped localized modes can be detected easily and provide more information about defected structures. Such method could increase the knowledge of manufacturing defects by measuring the intensity of propagated waves in the resonant cavities and waveguides. Moreover, several factors enhance the role of the defect layer on the transmission properties of defected phononic crystals are presented. The acoustic band gap can be used to detect or sense the type of liquids filling the defect layer. The liquids make specific resonant modes through the phononic band gaps that related to the properties of each liquid. The frequency where the maximum resonant modes occur is correlated to material properties and allows to determine several parameters such as the type of an unknown material.

  7. Fluid-structure interactions in one-dimensional linear cases

    Schumann, U.

    1979-01-01

    The interaction of pressure waves in a pipe with an elastic endwall (piston) is analyzed using a linear ('acoustic') model. Two transient and two periodic cases are investigated. In the transient cases the motions are initiated by either a sudden pressure drop at the opeen end (breaking membrane) or by a sudden release of the piston from a non-equilibrium position ('snapback'); in the latter case the other end of the pipe is closed. In the periodic cases harmonic oscillations of the piston and the fluid are investigated with the other end of the pipe being either closed or open (kept at constant pressure). The problem is characterized by three non-dimensional numbers (e.g.: Mach-, Strouhal-, and an interaction-number). The solution of the wave equation for the pressure accounting for the coupling to the structure can be reduced analytically to the problem of integrating one ordinary differential equation of second order in time. This differential equation in turn can be integrated analytically at least for a certain time period. At later times this ordinary differential equation is integrated numerically. For the periodic cases eigenvalue-problems arise with an infinite number of solutions. The first few eigensolutions are given. (orig./RW) [de

  8. Measurements of ion cyclotron range of frequencies mode converted wave intensity with phase contrast imaging in Alcator C-Mod and comparison with full-wave simulations

    Tsujii, N.; Porkolab, M.; Bonoli, P. T.; Lin, Y.; Wright, J. C.; Wukitch, S. J.; Jaeger, E. F.; Green, D. L.; Harvey, R. W.

    2012-01-01

    Radio frequency waves in the ion cyclotron range of frequencies (ICRF) are widely used to heat tokamak plasmas. In ICRF heating schemes involving multiple ion species, the launched fast waves convert to ion cyclotron waves or ion Bernstein waves at the two-ion hybrid resonances. Mode converted waves are of interest as actuators to optimise plasma performance through current drive and flow drive. In order to describe these processes accurately in a realistic tokamak geometry, numerical simulations are essential, and it is important that these codes be validated against experiment. In this study, the mode converted waves were measured using a phase contrast imaging technique in D-H and D- 3 He plasmas. The measured mode converted wave intensity in the D- 3 He mode conversion regime was found to be a factor of ∼50 weaker than the full-wave predictions. The discrepancy was reduced in the hydrogen minority heating regime, where mode conversion is weaker.

  9. Full-Wave Analysis of Traveling-Wave Field-Effect Transistors Using Finite-Difference Time-Domain Method

    Koichi Narahara

    2012-01-01

    Full Text Available Nonlinear transmission lines, which define transmission lines periodically loaded with nonlinear devices such as varactors, diodes, and transistors, are modeled in the framework of finite-difference time-domain (FDTD method. Originally, some root-finding routine is needed to evaluate the contributions of nonlinear device currents appropriately to the temporally advanced electrical fields. Arbitrary nonlinear transmission lines contain large amount of nonlinear devices; therefore, it costs too much time to complete calculations. To reduce the calculation time, we recently developed a simple model of diodes to eliminate root-finding routines in an FDTD solver. Approximating the diode current-voltage relation by a piecewise-linear function, an extended Ampere's law is solved in a closed form for the time-advanced electrical fields. In this paper, we newly develop an FDTD model of field-effect transistors (FETs, together with several numerical examples that demonstrate pulse-shortening phenomena in a traveling-wave FET.

  10. Full polarimetric millimetre wave radar for stand-off security screening

    Blackhurst, Eddie; Salmon, Neil; Southgate, Matthew

    2017-10-01

    The development and measurements are described of a frequency modulated continuous wave (FMCW) mono-static millimetre wave full polarimetric radar, operating at k-band (18 to 26 GHz). The system has been designed to explore the feasibility of using full polarimetry for the detection of concealed weapons, and person borne improvised explosive devices (PBIED). The philosophy of this scheme is a means to extract the maximum information content from a target which is normally in the single spatial pixel (sometimes sub-pixel) configuration in stand-off (tens of metres) and crowd surveillance scenarios. The radar comprises a vector network analyser (VNA), an orthomode transducer and a conical horn antenna. A calibration strategy is discussed and demonstrated using a variety of known calibration targets with known reflective properties, including a flat metal plate, dihedral reflector, metal sphere, helix and dipole. The orthomode transducer is based on a high performance linear polarizer of the turnstile type with isolation better than - 35dB between orthogonal polarisations. The calibration enables the polarimetric Sinclair scattering matrix to be measured at each frequency for coherent polarimetry, and this can be extended using multiple measurements via the Kennaugh matrix to investigate incoherent full polarimetry.

  11. Decoherence and Determinism in a One-Dimensional Cloud-Chamber Model

    Sparenberg, Jean-Marc; Gaspard, David

    2018-03-01

    The hypothesis (Sparenberg et al. in EPJ Web Conf 58:01016, [1]. https://doi.org/10.1051/epjconf/20135801016) that the particular linear tracks appearing in the measurement of a spherically-emitting radioactive source in a cloud chamber are determined by the (random) positions of atoms or molecules inside the chamber is further explored in the framework of a recently established one-dimensional model (Carlone et al. Comm Comput Phys 18:247, [2]. https://doi.org/10.4208/cicp.270814.311214a). In this model, meshes of localized spins 1/2 play the role of the cloud-chamber atoms and the spherical wave is replaced by a linear superposition of two wave packets moving from the origin to the left and to the right, evolving deterministically according to the Schrödinger equation. We first revisit these results using a time-dependent approach, where the wave packets impinge on a symmetric two-sided detector. We discuss the evolution of the wave function in the configuration space and stress the interest of a non-symmetric detector in a quantum-measurement perspective. Next we use a time-independent approach to study the scattering of a plane wave on a single-sided detector. Preliminary results are obtained, analytically for the single-spin case and numerically for up to 8 spins. They show that the spin-excitation probabilities are sometimes very sensitive to the parameters of the model, which corroborates the idea that the measurement result could be determined by the atom positions. The possible origin of decoherence and entropy increase in future models is finally discussed.

  12. Pseudo-One-Dimensional Magnonic Crystals for High-Frequency Nanoscale Devices

    Banerjee, Chandrima; Choudhury, Samiran; Sinha, Jaivardhan; Barman, Anjan

    2017-07-01

    The synthetic magnonic crystals (i.e., periodic composites consisting of different magnetic materials) form one fascinating class of emerging research field, which aims to command the process and flow of information by means of spin waves, such as in magnonic waveguides. One of the intriguing features of magnonic crystals is the presence and tunability of band gaps in the spin-wave spectrum, where the high attenuation of the frequency bands can be utilized for frequency-dependent control on the spin waves. However, to find a feasible way of band tuning in terms of a realistic integrated device is still a challenge. Here, we introduce an array of asymmetric saw-tooth-shaped width-modulated nanoscale ferromagnetic waveguides forming a pseudo-one-dimensional magnonic crystal. The frequency dispersion of collective modes measured by the Brillouin light-scattering technique is compared with the band diagram obtained by numerically solving the eigenvalue problem derived from the linearized Landau-Lifshitz magnetic torque equation. We find that the magnonic band-gap width, position, and the slope of dispersion curves are controllable by changing the angle between the spin-wave propagation channel and the magnetic field. The calculated profiles of the dynamic magnetization reveal that the corrugation at the lateral boundary of the waveguide effectively engineers the edge modes, which forms the basis of the interactive control in magnonic circuits. The results represent a prospective direction towards managing the internal field distribution as well as the dispersion properties, which find potential applications in dynamic spin-wave filters and magnonic waveguides in the gigahertz frequency range.

  13. Lime Kiln Modeling. CFD and One-dimensional simulations

    Svedin, Kristoffer; Ivarsson, Christofer; Lundborg, Rickard

    2009-03-15

    The incentives for burning alternative fuels in lime kilns are growing. An increasing demand on thorough investigations of alternative fuel impact on lime kiln performance have been recognized, and the purpose of this project has been to develop a lime kiln CFD model with the possibility to fire fuel oil and lignin. The second part of the project consists of three technical studies. Simulated data from a one-dimensional steady state program has been used to support theories on the impact of biofuels and lime mud dryness. The CFD simulations was carried out in the commercial code FLUENT. Due to difficulties with the convergence of the model the calcination reaction is not included. The model shows essential differences between the two fuels. Lignin gives a different flame shape and a longer flame length compared to fuel oil. Mainly this depends on how the fuel is fed into the combustion chamber and how much combustion air that is added as primary and secondary air. In the case of lignin combustion the required amount of air is more than in the fuel oil case. This generates more combustion gas and a different flow pattern is created. Based on the values from turbulent reaction rate for the different fuels an estimated flame length can be obtained. For fuel oil the combustion is very intense with a sharp peak in the beginning and a rapid decrease. For lignin the combustion starts not as intense as for the fuel oil case and has a smoother shape. The flame length appears to be approximately 2-3 meter longer for lignin than for fuel oil based on turbulent reaction rate in the computational simulations. The first technical study showed that there are many benefits of increasing dry solids content in the lime mud going into a kiln such as increased energy efficiency, reduced TRS, and reduced sodium in the kiln. However, data from operating kilns indicates that these benefits can be offset by increasing exit gas temperature that can limit kiln production capacity. Simulated

  14. Scramjet test flow reconstruction for a large-scale expansion tube, Part 1: quasi-one-dimensional modelling

    Gildfind, D. E.; Jacobs, P. A.; Morgan, R. G.; Chan, W. Y. K.; Gollan, R. J.

    2017-11-01

    Large-scale free-piston driven expansion tubes have uniquely high total pressure capabilities which make them an important resource for development of access-to-space scramjet engine technology. However, many aspects of their operation are complex, and their test flows are fundamentally unsteady and difficult to measure. While computational fluid dynamics methods provide an important tool for quantifying these flows, these calculations become very expensive with increasing facility size and therefore have to be carefully constructed to ensure sufficient accuracy is achieved within feasible computational times. This study examines modelling strategies for a Mach 10 scramjet test condition developed for The University of Queensland's X3 facility. The present paper outlines the challenges associated with test flow reconstruction, describes the experimental set-up for the X3 experiments, and then details the development of an experimentally tuned quasi-one-dimensional CFD model of the full facility. The 1-D model, which accurately captures longitudinal wave processes, is used to calculate the transient flow history in the shock tube. This becomes the inflow to a higher-fidelity 2-D axisymmetric simulation of the downstream facility, detailed in the Part 2 companion paper, leading to a validated, fully defined nozzle exit test flow.

  15. Scramjet test flow reconstruction for a large-scale expansion tube, Part 1: quasi-one-dimensional modelling

    Gildfind, D. E.; Jacobs, P. A.; Morgan, R. G.; Chan, W. Y. K.; Gollan, R. J.

    2018-07-01

    Large-scale free-piston driven expansion tubes have uniquely high total pressure capabilities which make them an important resource for development of access-to-space scramjet engine technology. However, many aspects of their operation are complex, and their test flows are fundamentally unsteady and difficult to measure. While computational fluid dynamics methods provide an important tool for quantifying these flows, these calculations become very expensive with increasing facility size and therefore have to be carefully constructed to ensure sufficient accuracy is achieved within feasible computational times. This study examines modelling strategies for a Mach 10 scramjet test condition developed for The University of Queensland's X3 facility. The present paper outlines the challenges associated with test flow reconstruction, describes the experimental set-up for the X3 experiments, and then details the development of an experimentally tuned quasi-one-dimensional CFD model of the full facility. The 1-D model, which accurately captures longitudinal wave processes, is used to calculate the transient flow history in the shock tube. This becomes the inflow to a higher-fidelity 2-D axisymmetric simulation of the downstream facility, detailed in the Part 2 companion paper, leading to a validated, fully defined nozzle exit test flow.

  16. Analytical Modeling of Transient Process In Terms of One-Dimensional Problem of Dynamics With Kinematic Action

    Kravets Victor V.

    2016-05-01

    Full Text Available One-dimensional dynamic design of a component characterized by inertia coefficient, elastic coefficient, and coefficient of energy dispersion. The component is affected by external action in the form of time-independent initial kinematic disturbances and varying ones. Mathematical model of component dynamics as well as a new form of analytical representation of transient in terms of one-dimensional problem of kinematic effect is provided. Dynamic design of a component is being carried out according to a theory of modal control.

  17. Synthetic Diagnostic for Doppler Backscattering (DBS) Turbulence Measurements based on Full Wave Simulations

    Ernst, D. R.; Rhodes, T. L.; Kubota, S.; Crocker, N.

    2017-10-01

    Plasma full-wave simulations of the DIII-D DBS system including its lenses and mirrors are developed using the GPU-based FDTD2D code, verified against the GENRAY ray-tracing code and TORBEAM paraxial beam code. Our semi-analytic description of the effective spot size for a synthetic diagnostic reveals new focusing and defocusing effects arising from the combined effects of the curvature of the reflecting surface and that of the Gaussian beam wavefront. We compute the DBS transfer function from full-wave simulations to verify these effects. Using the synthetic diagnostic, nonlinear GYRO simulations closely match DBS fluctuation spectra with and without strong electron heating, without adjustment or change in normalization, while both GYRO and GENE also match fluxes in all transport channels. Density gradient driven TEMs that are observed by the DBS diagnostic on DIII-D are reproduced by simulations as a band of discrete toroidal mode numbers which intensify during strong electron heating. Work supported by US DOE under DE-FC02-04ER54698 and DE-FG02-08ER54984.

  18. Ab initio/interpolated quantum dynamics on coupled electronic states with full configuration interaction wave functions

    Thompson, K.; Martinez, T.J.

    1999-01-01

    We present a new approach to first-principles molecular dynamics that combines a general and flexible interpolation method with ab initio evaluation of the potential energy surface. This hybrid approach extends significantly the domain of applicability of ab initio molecular dynamics. Use of interpolation significantly reduces the computational effort associated with the dynamics over most of the time scale of interest, while regions where potential energy surfaces are difficult to interpolate, for example near conical intersections, are treated by direct solution of the electronic Schroedinger equation during the dynamics. We demonstrate the concept through application to the nonadiabatic dynamics of collisional electronic quenching of Li(2p). Full configuration interaction is used to describe the wave functions of the ground and excited electronic states. The hybrid approach agrees well with full ab initio multiple spawning dynamics, while being more than an order of magnitude faster. copyright 1999 American Institute of Physics

  19. A one-dimensional model illustrating virtual-cathode formation in a novel coaxial virtual-cathode oscillator.

    Turner, GR

    2014-09-01

    Full Text Available A one-dimensional electrostatic sheet model of a coaxial geometry Virtual Cathode Oscillator (VCO) is presented. The cathode is centrally located and connects to a peripherally located plate electrode to form a resonant cavity, and is thus...

  20. A quasi-one-dimensional velocity regime of super-thermal electron stream propagation through the solar corona

    Levin, B.N.

    1984-01-01

    The propagation of an inhomogeneous stream of fast electrons through the corona - the type III radio burst source - is considered. It is shown, that the angular spectrum width of plasma waves excited by the stream is defined both by Landau damping by particles of the diffuse component and by damping (in the region of large phase velocities) by particles of the stream itself having large pitch angles. The regime of quasi-one-dimensional diffusion in the velocity space is realized only in the presence of a sufficiently dense diffuse component of super-thermal particles and only for a sufficiently large inhomogeneity scale of the stream. A large scale of the stream space profile is formed, evidently, close to the region of injection of super-thermal particles. It is the result of 'stripping' of part of the electrons from the stream front to its slower part due to essential non-one-dimensionality of the particle diffusion in velocity space. Results obtained may explain, in particular, the evolution of a stream particle angular spectrum in the generation region of type III radio bursts observed by spacecrafts (Lin et al., 1981). For the relatively low energetic part of the stream, the oblique plasma wave stabilization by a diffuse component results in a quasi-one-dimensional regime of diffusion. The latter conserves the beam-like structure of this part of the stream. (orig.)

  1. Magnon band structure and magnon density in one-dimensional magnonic crystals

    Qiu, Rong-ke; Huang, Te; Zhang, Zhi-dong

    2014-01-01

    By using Callen's Green's function method and the Tyablikov and Anderson–Callen decoupling approximations, we systematically study the magnon band structure and magnon density perpendicular to the superlattice plane of one-dimensional magnonic crystals, with a superlattice consisting of two magnetic layers with ferromagnetic (FM) or antiferromagnetic (AFM) interlayer exchange coupling. The effects of temperature, interlayer coupling, anisotropy and external magnetic field on the magnon-energy band and magnon density in the K x -direction are investigated in three situations: a) the magnon band of magnetic superlattices with FM interlayer coupling, b) separate and c) overlapping magnon bands of magnetic superlattices with AFM interlayer coupling. In the present work, a quantum approach is developed to study the magnon band structure and magnon density of magnonic crystals and the results are beneficial for the design of magnonic-crystal waveguides or gigahertz-range spin-wave filters. - Highlights: • A quantum approach has been developed to study the magnon band of magnonic crystals. • The separate and overlapping magnon bands of magnetic superlattices are investigated. • The results are beneficial for the design of gigahertz-range spin-wave filters

  2. Magnon band structure and magnon density in one-dimensional magnonic crystals

    Qiu, Rong-ke, E-mail: rkqiu@163.com [Shenyang University of Technology, Shenyang 110870 (China); Huang, Te [Shenyang University of Technology, Shenyang 110870 (China); Zhang, Zhi-dong [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2014-11-15

    By using Callen's Green's function method and the Tyablikov and Anderson–Callen decoupling approximations, we systematically study the magnon band structure and magnon density perpendicular to the superlattice plane of one-dimensional magnonic crystals, with a superlattice consisting of two magnetic layers with ferromagnetic (FM) or antiferromagnetic (AFM) interlayer exchange coupling. The effects of temperature, interlayer coupling, anisotropy and external magnetic field on the magnon-energy band and magnon density in the K{sub x}-direction are investigated in three situations: a) the magnon band of magnetic superlattices with FM interlayer coupling, b) separate and c) overlapping magnon bands of magnetic superlattices with AFM interlayer coupling. In the present work, a quantum approach is developed to study the magnon band structure and magnon density of magnonic crystals and the results are beneficial for the design of magnonic-crystal waveguides or gigahertz-range spin-wave filters. - Highlights: • A quantum approach has been developed to study the magnon band of magnonic crystals. • The separate and overlapping magnon bands of magnetic superlattices are investigated. • The results are beneficial for the design of gigahertz-range spin-wave filters.

  3. Gap solitons in elongated geometries: The one-dimensional Gross-Pitaevskii equation and beyond

    Mateo, A. Munoz; Delgado, V.; Malomed, Boris A.

    2011-01-01

    We report results of a systematic analysis of matter-wave gap solitons (GSs) in three-dimensional self-repulsive Bose-Einstein condensates (BECs) loaded into a combination of a cigar-shaped trap and axial optical-lattice (OL) potential. Basic cases of the strong, intermediate, and weak radial (transverse) confinement are considered, as well as settings with shallow and deep OL potentials. Only in the case of the shallow lattice combined with tight radial confinement, which actually has little relevance to realistic experimental conditions, does the usual one-dimensional (1D) cubic Gross-Pitaevskii equation (GPE) furnish a sufficiently accurate description of GSs. However, the effective 1D equation with the nonpolynomial nonlinearity, derived in Ref. [Phys. Rev. A 77, 013617 (2008)], provides for quite an accurate approximation for the GSs in all cases, including the situation with weak transverse confinement, when the soliton's shape includes a considerable contribution from higher-order transverse modes, in addition to the usual ground-state wave function of the respective harmonic oscillator. Both fundamental GSs and their multipeak bound states are considered. The stability is analyzed by means of systematic simulations. It is concluded that almost all the fundamental GSs are stable, while their bound states may be stable if the underlying OL potential is deep enough.

  4. Spinons, Solitons, and Breathers in Quasi-One-Dimensional Magnets

    Broholm, Collin

    2006-03-01

    By scattering neutrons from coordination polymer magnets, we contrast the effects of a uniform and a staggered magnetic field on the quantum critical state of a spin-1/2 chain. In a partially magnetized state of copper pyrazine dinitrate (CuPzN) we find bounded spectral continua indicating that neutrons scatter from spin-1/2 quasi-particle pairs [1]. The complex boundaries including an incommensurate soft spot result from a field induced shift in the Fermi points for these quasi-particles. The measurements indicate that the magnetized state of CuPzN remains quantum critical. Copper benzoate [2] and CuCl2^.2(dimethylsulfoxide) (CDC) [3] differ from CuPzN in that there are two spins per unit cell along the spin chain. Rather than continuous spectra, we find resolution limited gapped excitations when these materials are subject to high fields. So with two spins per unit cell, an applied field can drive the spin-1/2 chain away from criticality. The explanation for this effect was provided by Affleck and Oshikawa. The alternating coordination environment induces a transverse staggered field and spinon binding. The quantum sine-Gordon model is the relevant low energy field theory and it predicts soliton and breather excitations at specific energies and wave vectors that we compare to the experiments. We shall also compare a complete measurement of the dynamic spin correlation function for CDC in a field to exact diagonalization results for a spin-1/2 chain with a staggered and uniform magnetic field [4]. [1] M. B. Stone, D. H. Reich, C. Broholm, K. Lefmann, C. Rischel, C. P. Landee, and M. M. Turnbull, Phys. Rev. Lett. 91, 037205 (2003). [2] M. Kenzelmann, Y. Chien, C. Broholm, D. H. Reich, and Y. Qiu, Phys. Rev. Lett. 93, 017204 (2004). [3] D. C. Dender, P. R. Hammar, Daniel H. Reich, C. Broholm, and G. Aeppli, Phys. Rev. Lett. 79, 1750 (1997). [4] M. Kenzelmann, C. D. Batista, Y. Chen, C. Broholm, D. H. Reich, S. Park, and Y. Qiu, Phys. Rev. B 71, 094411 (2005).

  5. Orientation of One-Dimensional Silicon Polymer Films Studied by X-Ray Absorption Spectroscopy

    Md. Abdul Mannan

    2012-01-01

    Full Text Available Molecular orientations for thin films of one-dimensional silicon polymers grown by vacuum evaporation have been assigned by near-edge X-ray absorption fine structure (NEXAFS using linearly polarized synchrotron radiation. The polymer investigated was polydimethylsilane (PDMS which is the simplest stable silicon polymer, and one of the candidate materials for one-dimensional molecular wire. For PDMS films deposited on highly oriented pyrolytic graphite (HOPG, four resonance peaks have been identified in the Si K-edge NEXAFS spectra. Among these peaks, the intensities of the two peaks lower-energy at 1842.0 eV and 1843.2 eV were found to be strongly polarization dependent. The peaks are assigned to the resonance excitations from the Si 1s to σ∗ pyz and σ∗ px orbitals localized at the Si–C and Si–Si bonds, respectively. Quantitative evaluation of the polarization dependence of the NEXAFS spectra revealed that the molecules are self-assembled on HOPG surface, and the backbones of the PDMS are oriented nearly parallel to the surface. The observed orientation is opposite to the previously observed results for PDMS on the other surfaces such as oxide (indium tin oxide and metal (polycrystalline copper. The flat-lying feature of PDMS observed only on HOPG surface is attributed to the interaction between CH bonds in PDMS and π orbitals in HOPG surface.

  6. Quantized impedance dealing with the damping behavior of the one-dimensional oscillator

    Jinghao Zhu

    2015-11-01

    Full Text Available A quantized impedance is proposed to theoretically establish the relationship between the atomic eigenfrequency and the intrinsic frequency of the one-dimensional oscillator in this paper. The classical oscillator is modified by the idea that the electron transition is treated as a charge-discharge process of a suggested capacitor with the capacitive energy equal to the energy level difference of the jumping electron. The quantized capacitance of the impedance interacting with the jumping electron can lead the resonant frequency of the oscillator to the same as the atomic eigenfrequency. The quantized resistance reflects that the damping coefficient of the oscillator is the mean collision frequency of the transition electron. In addition, the first and third order electric susceptibilities based on the oscillator are accordingly quantized. Our simulation of the hydrogen atom emission spectrum based on the proposed method agrees well with the experimental one. Our results exhibits that the one-dimensional oscillator with the quantized impedance may become useful in the estimations of the refractive index and one- or multi-photon absorption coefficients of some nonmagnetic media composed of hydrogen-like atoms.

  7. Electronic structure and transport properties of quasi-one-dimensional carbon nanomaterials

    Y. N. Wu

    2017-09-01

    Full Text Available Based on the density functional theory combined with the nonequilibrium Green’s function, the influence of the wrinkle on the electronic structures and transport properties of quasi-one-dimensional carbon nanomaterials have been investigated, in which the wrinkled armchair graphene nanoribbons (wAGNRs and the composite of AGNRs and single walled carbon nanotubes (SWCNTs were considered with different connection of ripples. The wrinkle adjusts the electronic structures and transport properties of AGNRs. With the change of the strain, the wAGNRs for three width families reveal different electrical behavior. The band gap of AGNR(6 increases in the presence of the wrinkle, which is opposite to that of AGNR(5 and AGNR(7. The transport of AGNRs with the widths 6 or 7 has been modified by the wrinkle, especially by the number of isolated ripples, but it is insensitive to the strain. The nanojunctions constructed by AGNRs and SWCNTs can form the quantum wells, and some specific states are confined in wAGNRs. Although these nanojunctions exhibit the metallic, they have poor conductance due to the wrinkle. The filling of C20 into SWCNT has less influence on the electronic structure and transport of the junctions. The width and connection type of ripples have greatly influenced on the electronic structures and transport properties of quasi-one-dimensional nanomaterials.

  8. Brooks–Corey Modeling by One-Dimensional Vertical Infiltration Method

    Xuguang Xing

    2018-05-01

    Full Text Available The laboratory methods used for the soil water retention curve (SWRC construction and parameter estimation is time-consuming. A vertical infiltration method was proposed to estimate parameters α and n and to further construct the SWRC. In the present study, the relationships describing the cumulative infiltration and infiltration rate with the depth of the wetting front were established, and simplified expressions for estimating α and n parameters were proposed. The one-dimensional vertical infiltration experiments of four soils were conducted to verify if the proposed method would accurately estimate α and n. The fitted values of α and n, obtained from the RETC software, were consistent with the calculated values obtained from the infiltration method. The comparison between the measured SWRCs obtained from the centrifuge method and the calculated SWRCs that were based on the infiltration method displayed small values of root mean square error (RMSE, mean absolute percentage error (MAPE, and mean absolute error. SWMS_2D-based simulations of cumulative infiltration, based on the calculated α and n, remained consistent with the measured values due to small RMSE and MAPE values. The experiments verified the proposed one-dimensional vertical infiltration method, which has applications in field hydraulic parameter estimation.

  9. Wind Farm Siting and Protected Areas in Catalonia: Planning Alternatives or Reproducing 'One-Dimensional Thinking'?

    Katharine N. Farrell

    2012-11-01

    Full Text Available Wind energy is an emblem of sustainability with the potential to promote a qualitative alternative to current energy systems and nuclear options for CO2 reduction. However, wind farm siting often conflicts with aspirations to conserve traditional landscapes and wildlife habitats. In this paper we adopt a Critical Theory perspective, informed by Herbert Marcuse`s work, to study the discourse concerning wind energy siting in Catalonia, Spain. We give particular attention to how tensions between potentially conflicting sustainability objectives are addressed and by whom. Based on a review of this siting discourse and the application of Marcuse’s theory, we find that the Catalan wind energy siting discourse is both influenced by and reproducing what Marcuse referred to as the ‘one-dimensional thinking’ of technology as ideology: erasing the possibility of critical dialectical thought by subsuming the question of “what should be” under the question of “what is”. This has implications both for how these conflicts are investigated and for the sustainability of decisions taken. We conclude that closer attention to the role of ‘one-dimensional thinking’ in wind energy siting discourses could improve not only the understanding of their logic but might also have the potential to help make them more democratic.

  10. Effects of Initial Symmetry on the Global Symmetry of One-Dimensional Legal Cellular Automata

    Ikuko Tanaka

    2015-09-01

    Full Text Available To examine the development of pattern formation from the viewpoint of symmetry, we applied a two-dimensional discrete Walsh analysis to a one-dimensional cellular automata model under two types of regular initial conditions. The amount of symmetropy of cellular automata (CA models under regular and random initial conditions corresponds to three Wolfram’s classes of CAs, identified as Classes II, III, and IV. Regular initial conditions occur in two groups. One group that makes a broken, regular pattern formation has four types of symmetry, whereas the other group that makes a higher hierarchy pattern formation has only two types. Additionally, both final pattern formations show an increased amount of symmetropy as time passes. Moreover, the final pattern formations are affected by iterations of base rules of CA models of chaos dynamical systems. The growth design formations limit possibilities: the ratio of developing final pattern formations under a regular initial condition decreases in the order of Classes III, II, and IV. This might be related to the difference in degree in reference to surrounding conditions. These findings suggest that calculations of symmetries of the structures of one-dimensional cellular automata models are useful for revealing rules of pattern generation for animal bodies.

  11. Spin waves in full-polarized state of Dzyaloshinskii-Moriya helimagnets: Small-angle neutron scattering study

    Grigoriev, S. V.; Sukhanov, A. S.; Altynbaev, E. V.; Siegfried, S.-A.; Heinemann, A.; Kizhe, P.; Maleyev, S. V.

    2015-12-01

    We develop the technique to study the spin-wave dynamics of the full-polarized state of the Dzyaloshinskii-Moriya helimagnets by polarized small-angle neutron scattering. We have experimentally proven that the spin-waves dispersion in this state has the anisotropic form. We show that the neutron scattering image displays a circle with a certain radius which is centered at the momentum transfer corresponding to the helix wave vector in helimagnetic phase ks, which is oriented along the applied magnetic field H . The radius of this circle is directly related to the spin-wave stiffness of this system. This scattering depends on the neutron polarization showing the one-handed nature of the spin waves in Dzyaloshinskii-Moriya helimagnets in the full-polarized phase. We show that the spin-wave stiffness A for MnSi helimagnet decreased twice as the temperature increases from zero to the critical temperature Tc.

  12. Full wave field recording of the vertical strain at SAFOD from local, regional and teleseismic earthquakes

    Ellsworth, W. L.; Karrenbach, M. H.; Zumberge, M. A.

    2017-12-01

    The main borehole at the San Andreas Fault Observatory at Depth (SAFOD) contains optical fibers cemented in place in between casing strings from the surface to just below the top of the basement. The fibers are under tension of approximately 1 N and are housed in a 0.9 mm diameter stainless steel tube. Earth strain is transmitted to the fiber by frictional contact with the tube wall. One fiber has been in use as a vertical strainmeter since 2005, measuring the total strain between 9 and 740 m by laser interferometry. In June 2017 we attached an OptaSense Distributed Acoustic Sensing (DAS) system, model ODH3.1, to a second fiber that terminates at 864 m depth. The DAS laser interrogator measures the strain over a gauge length with a set spacing between gauge intervals. For this experiment we set the gauge length to 10 m with 1 m spacing between gauges. Including the surface run of the fiber, this gives us 936 channels measuring the vertical strain at a sample interval of 0.4 msec (2500 samples/s). Continuous recording of the string produces approximately 1 TB/day. During one month of data collection, we recorded local, regional and teleseismic earthquakes. With this recording geometry, the DAS system captures the full vertical wavefield between the basement interface and free surface, revealing direct, converted and refracted waves. Both P- and S- strain waves are clearly visible in the data, even for 10 km deep earthquakes located almost directly below the well (see figure). The incident and surface reflected wavefields can be separated by frequency-wavenumber filtering due to the large-aperture and fine spatial and temporal sampling. Up- and downgoing strain waves illuminate the subsurface within the sensor array's depth range. Accurate arrival time determinations of the initial arrival phase are possible due to consistent wave forms recorded at 1 m spatial intervals that can be used for fine-scale shallow velocity model estimation.

  13. One-dimensional diffusion model in an Inhomogeneous region

    Fedotov, I

    2006-01-01

    Full Text Available ) of these atoms. The enthalpy of formation of free atoms, ∆H, can vary between 50 and 300 kJ.mol-1. The ballast is heated by radiation from the walls of the atomizer, and its temperature, Tb(t), is given by the Stefan-Boltzmann equation [4...]: ( )ddt T t E c S V T t T tb b b b b b w b( ) ( ) ( )= −σ ρ 4 4 (6) where σ is the Stefan-Boltzmann constant, Eb is the emissivity of the ballast material, cb is the heat capacity of ballast material, ρb...

  14. One-dimensional models of thermal activation under shear stress

    Nabarro, FRN

    2003-01-01

    Full Text Available - dimensional models presented here may illuminate the study of more realistic models. For the model in which as many dislocations are poised for backward jumps as for forward jumps, the experimental activation volume Vye(C27a) under applied stresses close to C...27a is different from the true activation volume V(C27) evaluated at C27 ?C27a. The relations between the two are developed. A model is then discussed in which fewer dislocations are available for backward than for forward jumps. Finally...

  15. Integration of meanline and one-dimensional methods for prediction of pulsating performance of a turbocharger turbine

    Chiong, M.S.; Rajoo, S.; Romagnoli, A.; Costall, A.W.; Martinez-Botas, R.F.

    2014-01-01

    Highlights: • Unsteady turbine performance prediction by integrating the 1-D and meanline models. • The optimum discretization length/diameter ratio is identified. • No improvement is gained by increasing the number of rotor entries. • The predicted instantaneous mass flow and output power are analysed in detail. - Abstract: Stringent emission regulations are driving engine manufacturers to increase investment into enabling technologies to achieve better specific fuel consumption, thermal efficiency and most importantly carbon reduction. Engine downsizing is seen as a key enabler to successfully achieve all of these requirements. Boosting through turbocharging is widely regarded as one of the most promising technologies for engine downsizing. However, the wide range of engine speeds and loads requires enhanced quality of engine-turbocharger matching, compared to the conventional approach which considers only the full load condition. Thus, development of computational models capable of predicting the unsteady behaviour of a turbocharger turbine is crucial to the overall matching process. A purely one-dimensional (1D) turbine model is capable of good unsteady swallowing capacity predictions, however it has not been fully exploited to predict instantaneous turbine power. On the contrary, meanline models (zero-dimensional) are regarded as a good tool to determine turbine efficiency in steady state but they do not include any information about the pressure wave action occurring within the turbine. This paper explores an alternative methodology to predict instantaneous turbine power and swallowing capacity by integrating one-dimensional and meanline models. A single entry mixed-flow turbine is modelled using a 1D gas dynamic code to solve the unsteady flow state in the volute, consequently used as the input for a meanline model to evaluate the instantaneous turbine power. The key in the effectiveness of this methodology relies on the synchronisation of the flow

  16. Empirical assessment of the validity limits of the surface wave full ray theory using realistic 3-D Earth models

    Parisi, Laura; Ferreira, Ana M.G.

    2016-01-01

    The surface wave full ray theory (FRT) is an efficient tool to calculate synthetic waveforms of surface waves. It combines the concept of local modes with exact ray tracing as a function of frequency, providing a more complete description of surface

  17. GITTAM program for numerical simulation of one-dimensional targets TIS. Part 2

    Arpishkin, Yu.P.; Basko, M.M.; Sokolovskij, M.V.

    1989-01-01

    A finite-difference algorithm for numeric solution of a system of one-dimensional hydrodynamics equation with heat conductivity, radiation diffusion and thermonuclear combustion is considered. The algorithm presented allows one to simulate one-dimensional thermonuclear targets for heavy-ion synthesis (HIS), irradiated with heavy ion beams. A brief description of a complex of GITTAM programs in which finite-difference algorithm for one-dimensional thermonuclear HIS target simulation is used, is given. 5 refs.; 3 figs

  18. One-Dimensional Modelling of Marine Current Turbine Runaway Behaviour

    Staffan Lundin

    2016-04-01

    Full Text Available If a turbine loses its electrical load, it will rotate freely and increase speed, eventually achieving that rotational speed which produces zero net torque. This is known as a runaway situation. Unlike many other types of turbine, a marine current turbine will typically overshoot the final runaway speed before slowing down and settling at the runaway speed. Since the hydrodynamic forces acting on the turbine are dependent on rotational speed and acceleration, turbine behaviour during runaway becomes important for load analyses during turbine design. In this article, we consider analytical and numerical models of marine current turbine runaway behaviour in one dimension. The analytical model is found not to capture the overshoot phenomenon, while still providing useful estimates of acceleration at the onset of runaway. The numerical model incorporates turbine wake build-up and predicts a rotational speed overshoot. The predictions of the models are compared against measurements of runaway of a marine current turbine. The models are also used to recreate previously-published results for a tidal turbine and applied to a wind turbine. It is found that both models provide reasonable estimates of maximum accelerations. The numerical model is found to capture the speed overshoot well.

  19. Sufficient condition for existence of solutions for higher-order resonance boundary value problem with one-dimensional p-Laplacian

    Liu Yang

    2007-10-01

    Full Text Available By using coincidence degree theory of Mawhin, existence results for some higher order resonance multipoint boundary value problems with one dimensional p-Laplacian operator are obtained.

  20. A Potential Method for Body and Surface Wave Propagation in Transversely Isotropic Half- and Full-Spaces

    Mehdi Raoofian Naeeni

    2016-12-01

    Full Text Available The problem of propagation of plane wave including body and surface waves propagating in a transversely isotropic half-space with a depth-wise axis of material symmetry is investigated in details. Using the advantage of representation of displacement fields in terms of two complete scalar potential functions, the coupled equations of motion are uncoupled and reduced to two independent equations for potential functions. In this paper, the secular equations for determination of body and surface wave velocities are derived in terms of both elasticity coefficients and the direction of propagation. In particular, the longitudinal, transverse and Rayleigh wave velocities are determined in explicit forms. It is also shown that in transversely isotropic materials, a Rayleigh wave may propagate in different manner from that of isotropic materials. Some numerical results for synthetic transversely isotropic materials are also illustrated to show the behavior of wave motion due to anisotropic nature of the problem.