Functional dependence of resonant harmonics on nanomechanical parameters in dynamic mode atomic force microscopy.

Science.gov (United States)

Gramazio, Federico; Lorenzoni, Matteo; Pérez-Murano, Francesc; Rull Trinidad, Enrique; Staufer, Urs; Fraxedas, Jordi

2017-01-01

We present a combined theoretical and experimental study of the dependence of resonant higher harmonics of rectangular cantilevers of an atomic force microscope (AFM) as a function of relevant parameters such as the cantilever force constant, tip radius and free oscillation amplitude as well as the stiffness of the sample's surface. The simulations reveal a universal functional dependence of the amplitude of the 6th harmonic (in resonance with the 2nd flexural mode) on these parameters, which can be expressed in terms of a gun-shaped function. This analytical expression can be regarded as a practical tool for extracting qualitative information from AFM measurements and it can be extended to any resonant harmonics. The experiments confirm the predicted dependence in the explored 3-45 N/m force constant range and 2-345 GPa sample's stiffness range. For force constants around 25 N/m, the amplitude of the 6th harmonic exhibits the largest sensitivity for ultrasharp tips (tip radius below 10 nm) and polymers (Young's modulus below 20 GPa).

Faddeev wave function decomposition using bipolar harmonics

International Nuclear Information System (INIS)

Friar, J.L.; Tomusiak, E.L.; Gibson, B.F.; Payne, G.L.

1981-01-01

The standard partial wave (channel) representation for the Faddeev solution to the Schroedinger equation for the ground state of 3 nucleons is written in terms of functions which couple the interacting pair and spectator angular momenta to give S, P, and D waves. For each such coupling there are three terms, one for each of the three cyclic permutations of the nucleon coordinates. A series of spherical harmonic identities is developed which allows writing the Faddeev solution in terms of a basis set of 5 bipolar harmonics: 1 for S waves; 1 for P waves; and 3 for D waves. The choice of a D-wave basis is largely arbitrary, and specific choices correspond to the decomposition schemes of Derrick and Blatt, Sachs, Gibson and Schiff, and Bolsterli and Jezak. The bipolar harmonic form greatly simplifies applications which utilize the wave function, and we specifically discuss the isoscalar charge (or mass) density and the 3 He Coulomb energy

Exact Time-Dependent Wave Functions of a Confined Time-Dependent Harmonic Oscillator with Two Moving Boundaries

International Nuclear Information System (INIS)

Lo, C.F.

2009-01-01

By applying the standard analytical techniques of solving partial differential equations, we have obtained the exact solution in terms of the Fourier sine series to the time-dependent Schroedinger equation describing a quantum one-dimensional harmonic oscillator of time-dependent frequency confined in an infinite square well with the two walls moving along some parametric trajectories. Based upon the orthonormal basis of quasi-stationary wave functions, the exact propagator of the system has also been analytically derived. Special cases like (i) a confined free particle, (ii) a confined time-independent harmonic oscillator, and (iii) an aging oscillator are examined, and the corresponding time-dependent wave functions are explicitly determined. Besides, the approach has been extended to solve the case of a confined generalized time-dependent harmonic oscillator for some parametric moving boundaries as well. (general)

Current Harmonics from Single-Phase Grid-Connected Inverters

DEFF Research Database (Denmark)

Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

2016-01-01

Environmental conditions and operational modes may significantly impact the distortion level of the injected current from single-phase grid-connected inverter systems, such as photovoltaic (PV) inverters, which may operate in cloudy days with a maximum power point tracking, in a non-unity power...... factor, or in the low voltage ride through mode with reactive current injection. In this paper, the mechanism of the harmonic current injection from grid-connected single-phase inverter systems is thus explored, and the analysis is conducted on single-phase PV systems. In particular, the analysis...... is focused on the impacts of the power factor and the feed-in grid current level on the quality of the feed-in grid current from single-phase inverters. As a consequence, an internal model principle based high performance current control solution is tailor-made and developed for single-phase grid-connected...

Trapping of a particle in a short-range harmonic potential well

OpenAIRE

Castro, L. B.; de Castro, A. S.

2012-01-01

Eigenstates of a particle in a localized and unconfined harmonic potential well are investigated. Effects due to the variation of the potential parameters as well as certain results from asymptotic expansions are discussed.

Floquet-Green function formalism for harmonically driven Hamiltonians

International Nuclear Information System (INIS)

Martinez, D F

2003-01-01

A method is proposed for the calculation of the Floquet-Green function of a general Hamiltonian with harmonic time dependence. We use matrix continued fractions to derive an expression for the 'dynamical effective potential' that can be used to calculate the Floquet-Green function of the system. We demonstrate the formalism for the simple case of a space-periodic (in the tight-binding approximation) Hamiltonian with a defect whose on-site energy changes harmonically with time. We study the local density of states for this system and the behaviour of the localized states as a function of the different parameters that characterize the system

About the functions of the Wigner distribution for the q-deformed harmonic oscillator model

International Nuclear Information System (INIS)

Atakishiev, N.M.; Nagiev, S.M.; Djafarov, E.I.; Imanov, R.M.

2005-01-01

Full text : A q-deformed model of the linear harmonic oscillator in the Wigner phase-space is studied. It was derived an explicit expression for the Wigner probability distribution function, as well as the Wigner distribution function of a thermodynamic equilibrium for this model

High-order harmonic generation in solid slabs beyond the single-active-electron approximation

Science.gov (United States)

Hansen, Kenneth K.; Deffge, Tobias; Bauer, Dieter

2017-11-01

High-harmonic generation by a laser-driven solid slab is simulated using time-dependent density functional theory. Multiple harmonic plateaus up to very high harmonic orders are observed already at surprisingly low field strengths. The full all-electron harmonic spectra are, in general, very different from those of any individual Kohn-Sham orbital. Freezing the Kohn-Sham potential instead is found to be a good approximation for the laser intensities and harmonic orders considered. The origins of the plateau cutoffs are explained in terms of band gaps that can be reached by Kohn-Sham electrons and holes moving through the band structure.

Efficient molecular density functional theory using generalized spherical harmonics expansions.

Science.gov (United States)

Ding, Lu; Levesque, Maximilien; Borgis, Daniel; Belloni, Luc

2017-09-07

We show that generalized spherical harmonics are well suited for representing the space and orientation molecular density in the resolution of the molecular density functional theory. We consider the common system made of a rigid solute of arbitrary complexity immersed in a molecular solvent, both represented by molecules with interacting atomic sites and classical force fields. The molecular solvent density ρ(r,Ω) around the solute is a function of the position r≡(x,y,z) and of the three Euler angles Ω≡(θ,ϕ,ψ) describing the solvent orientation. The standard density functional, equivalent to the hypernetted-chain closure for the solute-solvent correlations in the liquid theory, is minimized with respect to ρ(r,Ω). The up-to-now very expensive angular convolution products are advantageously replaced by simple products between projections onto generalized spherical harmonics. The dramatic gain in speed of resolution enables to explore in a systematic way molecular solutes of up to nanometric sizes in arbitrary solvents and to calculate their solvation free energy and associated microscopic solvent structure in at most a few minutes. We finally illustrate the formalism by tackling the solvation of molecules of various complexities in water.

Structural relations between nested harmonic sums

International Nuclear Information System (INIS)

Bluemlein, J.

2008-07-01

We describe the structural relations between nested harmonic sums emerging in the description of physical single scale quantities up to the 3-loop level in renormalizable gauge field theories. These are weight w=6 harmonic sums. We identify universal basic functions which allow to describe a large class of physical quantities and derive their complex analysis. For the 3-loop QCD Wilson coefficients 35 basic functions are required, whereas a subset of 15 describes the 3-loop anomalous dimensions. (orig.)

Structural relations between nested harmonic sums

Energy Technology Data Exchange (ETDEWEB)

Bluemlein, J.

2008-07-15

We describe the structural relations between nested harmonic sums emerging in the description of physical single scale quantities up to the 3-loop level in renormalizable gauge field theories. These are weight w=6 harmonic sums. We identify universal basic functions which allow to describe a large class of physical quantities and derive their complex analysis. For the 3-loop QCD Wilson coefficients 35 basic functions are required, whereas a subset of 15 describes the 3-loop anomalous dimensions. (orig.)

Harmonic Function of Poincare Cone Condition In Solving Dirichlet ...

African Journals Online (AJOL)

This paper describes the set of harmonic functions on a given open set U which can be seen as the kernel of the Laplace operator and is therefore a vector space over R .It also reviews the harmonic theorem, the dirichlet problem and maximum principle where we conclude that the application of sums , differences and ...

Harmonics Suppression for Single-Phase Grid-Connected Photovoltaic Systems in Different Operation Modes

DEFF Research Database (Denmark)

Yang, Yongheng; Zhou, Keliang; Blaabjerg, Frede

2013-01-01

-connected PV inverters may be severely affected in different operation modes. In this paper, a detailed analysis is conducted to reveal the relationship between the harmonics level with the power factor and the current level in the PV systems. A current control solution which employs an Internal Model...... Principle (IMP) is proposed to suppress the harmonic currents injected into the grid. Experiments are carried out to verify the analysis and the performance of the proposed control method. It is demonstrated that the proposed method presents an effective solution to harmonics suppression for single......-phase grid-connected PV systems in different operation modes. Especially, it can remove higher order harmonics effectively leading to a better power quality compared to the Proportional plus Multi-Resonant Controller, and it has less computational burden....

Wave function for harmonically confined electrons in time-dependent electric and magnetostatic fields.

Science.gov (United States)

Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin; Sahni, Viraht

2014-01-14

We derive via the interaction "representation" the many-body wave function for harmonically confined electrons in the presence of a magnetostatic field and perturbed by a spatially homogeneous time-dependent electric field-the Generalized Kohn Theorem (GKT) wave function. In the absence of the harmonic confinement - the uniform electron gas - the GKT wave function reduces to the Kohn Theorem wave function. Without the magnetostatic field, the GKT wave function is the Harmonic Potential Theorem wave function. We further prove the validity of the connection between the GKT wave function derived and the system in an accelerated frame of reference. Finally, we provide examples of the application of the GKT wave function.

Tax competition and tax harmonization in the European Union

Directory of Open Access Journals (Sweden)

Danuše Nerudová

2004-01-01

Full Text Available The article deals with the problems of tax competition and harmonization within the European Union. It reveals the single difficulties connected with harmonization, identifies the problems arising from tax competition and points out the harmful tax competition as well. Single compulsory harmonized tax base in connection with prevailing tax competition in the area of tax rates is the suggested solution in the scope of direct taxation. As the solution in the area of indirect taxation could serve the introduction of “principle of origin”. This would cause remarkable administrative costs decrease not only for economic subjects but for tax authorities as well.

Probabilistic Aspects of Harmonic Emission of Large Offshore Wind Farms

DEFF Research Database (Denmark)

Jensen, Christian Flytkjær; Bak, Claus Leth; Kocewiak, Lukasz Hubert

2011-01-01

In this article, a new probabilistic method of as-sessment of harmonic emission of large offshore wind farms is presented. Based on measurements from the British wind farm Burbo Banks, probability density functions are estimated for the dominating low order harmonic currents injected by a single...... turbine. The degree and type of dependence between the harmonic emission and the operating point of a single turbine is established. A model of Burbo Banks, suitable for harmonic load flow studies, is created in DIgSILENT Power Factory along with a DPL-script that deals with the probabilistic issues...... of the harmonic emission. The simulated harmonic distortion at the PCC is compared to measurement. This reveals some diffi-culties regarding harmonic load flow studies. The harmonic background distortion in the grid to where the wind farm is connected must be included in the study. Furthermore, a very detailed...

Mehler's formulae for isotropic harmonic oscillator wave functions and application in the Green function calculus

International Nuclear Information System (INIS)

Caetano Neto, E.S.

1976-01-01

A stationary Green function is calculated for the Schroedinger Hamiltonian of the multidimensional isotropic harmonic oscillator and for physical systems, which may, somehow, have their Hamiltonian reduced to one in the form of a harmonic oscillator, for any dimension [pt

Probabilistic aspects of harmonic emission of large offshore wind farms

Energy Technology Data Exchange (ETDEWEB)

Jensen, Christian F. [Energinet.dk, Fredericia (Denmark); Bak, Claus L. [Aalborg Univ. (Denmark). Dept. of Energy Technology; Kocewiak, Lukasz; Hjerrild, Jesper [DONG Energy, Skaerbaek (Denmark); Berthelsen, Kasper K. [Aalborg Univ. (Denmark). Dept. of Mathematical Sciences

2011-07-01

In this article, a new probabilistic method of assessment of harmonic emission of large offshore wind farms is presented. Based on measurements from the British wind farm Burbo Banks, probability density functions are estimated for the dominating low order harmonic currents injected by a single turbine. The degree and type of dependence between the harmonic emission and the operating point of a single turbine is established. A model of Burbo Banks, suitable for harmonic load flow studies, is created in DIgSILENT Power Factory along with a DPL-script that deals with the probabilistic issues of the harmonic emission. The simulated harmonic distortion at the PCC is compared to measurement. This reveals some difficulties regarding harmonic load flow studies. The harmonic background distortion in the grid to where the wind farms is connected must be included in the study. Furthermore, a very detailed representation of the frequency dependent short circuit impedance must be used before sufficiently accurate results can be obtained from the model. (orig.)

Multidimensional high harmonic spectroscopy

International Nuclear Information System (INIS)

Bruner, Barry D; Soifer, Hadas; Shafir, Dror; Dudovich, Nirit; Serbinenko, Valeria; Smirnova, Olga

2015-01-01

High harmonic generation (HHG) has opened up a new frontier in ultrafast science where attosecond time resolution and Angstrom spatial resolution are accessible in a single measurement. However, reconstructing the dynamics under study is limited by the multiple degrees of freedom involved in strong field interactions. In this paper we describe a new class of measurement schemes for resolving attosecond dynamics, integrating perturbative nonlinear optics with strong-field physics. These approaches serve as a basis for multidimensional high harmonic spectroscopy. Specifically, we show that multidimensional high harmonic spectroscopy can measure tunnel ionization dynamics with high precision, and resolves the interference between multiple ionization channels. In addition, we show how multidimensional HHG can function as a type of lock-in amplifier measurement. Similar to multi-dimensional approaches in nonlinear optical spectroscopy that have resolved correlated femtosecond dynamics, multi-dimensional high harmonic spectroscopy reveals the underlying complex dynamics behind attosecond scale phenomena. (paper)

Single nano-hole as a new effective nonlinear element for third-harmonic generation

Science.gov (United States)

Melentiev, P. N.; Konstantinova, T. V.; Afanasiev, A. E.; Kuzin, A. A.; Baturin, A. S.; Tausenev, A. V.; Konyaschenko, A. V.; Balykin, V. I.

2013-07-01

In this letter, we report on a particularly strong optical nonlinearity at the nanometer scale in aluminum. A strong optical nonlinearity of the third order was demonstrated on a single nanoslit. Single nanoslits of different aspect ratio were excited by a laser pulse (120 fs) at the wavelength 1.5 μm, leading predominantly to third-harmonic generation (THG). It has been shown that strong surface plasmon resonance in a nanoslit allows the realization of an effective nanolocalized source of third-harmonic radiation. We show also that a nanoslit in a metal film has a significant advantage in nonlinear processes over its Babinet complementary nanostructure (nanorod): the effective abstraction of heat in a film with a slit makes it possible to use much higher laser radiation intensities.

Human brain networks function in connectome-specific harmonic waves.

Science.gov (United States)

Atasoy, Selen; Donnelly, Isaac; Pearson, Joel

2016-01-21

A key characteristic of human brain activity is coherent, spatially distributed oscillations forming behaviour-dependent brain networks. However, a fundamental principle underlying these networks remains unknown. Here we report that functional networks of the human brain are predicted by harmonic patterns, ubiquitous throughout nature, steered by the anatomy of the human cerebral cortex, the human connectome. We introduce a new technique extending the Fourier basis to the human connectome. In this new frequency-specific representation of cortical activity, that we call 'connectome harmonics', oscillatory networks of the human brain at rest match harmonic wave patterns of certain frequencies. We demonstrate a neural mechanism behind the self-organization of connectome harmonics with a continuous neural field model of excitatory-inhibitory interactions on the connectome. Remarkably, the critical relation between the neural field patterns and the delicate excitation-inhibition balance fits the neurophysiological changes observed during the loss and recovery of consciousness.

Structural relations of harmonic sums and Mellin transforms up to weight w=5

Energy Technology Data Exchange (ETDEWEB)

Bluemlein, Johannes

2009-01-15

We derive the structural relations between the Mellin transforms of weighted Nielsen integrals emerging in the calculation of massless or massive single-scale quantities in QED and QCD, such as anomalous dimensions and Wilson coefficients, and other hard scattering cross sections depending on a single scale. The set of all multiple harmonic sums up to weight five cover the sums needed in the calculation of the 3-loop anomalous dimensions. The relations extend the set resulting from the quasi-shuffle product between harmonic sums studied earlier. Unlike the shuffle relations, they depend on the value of the quantities considered. Up to weight w=5, 242 nested harmonic sums contribute. In the present physical applications it is sufficient to consider the sub-set of harmonic sums not containing an index i=-1, which consists out of 69 sums. The algebraic relations reduce this set to 30 sums. Due to the structural relations a final reduction of the number of harmonic sums to 15 basic functions is obtained. These functions can be represented in terms of factorial series, supplemented by harmonic sums which are algebraically reducible. Complete analytic representations are given for these 15 meromorphic functions in the complex plane deriving their asymptotic- and recursion relations. A general outline is presented on the way nested harmonic sums and multiple zeta values emerge in higher order calculations of zero- and single scale quantities. (orig.)

Stability and nonlinear dynamics of gyrotrons at cyclotron harmonics

International Nuclear Information System (INIS)

Saraph, G.P.; Nusinovich, G.S.; Antonsen, T.M. Jr.; Levush, B.

1992-01-01

Gyrotrons operating at higher harmonics of the cyclotron frequency can overcome the frequency limitations caused by achievable strength of the magnetic field. However, the excitation of modes at the fundamental frequency exhibit a major problem for stable operation of harmonic gyrotron at high power with high efficiency. Therefore the issues of stability of gyrotron operation at the cyclotron harmonics and nonlinear dynamics of mode interaction are of great importance. The results of the authors stability analysis and multimode simulation are presented here. A detailed nonlinear theory of steady state single mode operation at cyclotron harmonics has been presented previously, taking into account beam-wave coupling and nonlinear gain function at cyclotron harmonics. A set of equations describing low gain regime interaction of modes resonant at different cyclotron harmonics was studied before. The multifrequency time-dependent nonlinear analysis presented here is based on previous gyrotron studies and beam-wave interaction at cyclotron harmonics. The authors have determined the parameter space for stable single mode operation at the second harmonic. The nonlinear dynamics of mode evolution and mode interaction for a harmonic gyrotron is presented. A new nonlinear effect in which the parasite at the fundamental harmonic helps excite the operating mode at the second harmonic has been demonstrated

Three-Dimensional Visualization of Wave Functions for Rotating Molecule: Plot of Spherical Harmonics

Science.gov (United States)

Nagaoka, Shin-ichi; Teramae, Hiroyuki; Nagashima, Umpei

2013-01-01

At an early stage of learning quantum chemistry, undergraduate students usually encounter the concepts of the particle in a box, the harmonic oscillator, and then the particle on a sphere. Rotational levels of a diatomic molecule can be well approximated by the energy levels of the particle on a sphere. Wave functions for the particle in a…

Functional geometric method for solving free boundary problems for harmonic functions

Energy Technology Data Exchange (ETDEWEB)

Demidov, Aleksander S [M. V. Lomonosov Moscow State University, Moscow (Russian Federation)

2010-01-01

A survey is given of results and approaches for a broad spectrum of free boundary problems for harmonic functions of two variables. The main results are obtained by the functional geometric method. The core of these methods is an interrelated analysis of the functional and geometric characteristics of the problems under consideration and of the corresponding non-linear Riemann-Hilbert problems. An extensive list of open questions is presented. Bibliography: 124 titles.

Frames and other bases in abstract and function spaces novel methods in harmonic analysis

CERN Document Server

Gia, Quoc; Mayeli, Azita; Mhaskar, Hrushikesh; Zhou, Ding-Xuan

2017-01-01

The first of a two volume set on novel methods in harmonic analysis, this book draws on a number of original research and survey papers from well-known specialists detailing the latest innovations and recently discovered links between various fields. Along with many deep theoretical results, these volumes contain numerous applications to problems in signal processing, medical imaging, geodesy, statistics, and data science. The chapters within cover an impressive range of ideas from both traditional and modern harmonic analysis, such as: the Fourier transform, Shannon sampling, frames, wavelets, functions on Euclidean spaces, analysis on function spaces of Riemannian and sub-Riemannian manifolds, Fourier analysis on manifolds and Lie groups, analysis on combinatorial graphs, sheaves, co-sheaves, and persistent homologies on topological spaces. Volume I is organized around the theme of frames and other bases in abstract and function spaces, covering topics such as: The advanced development of frames, including ...

Single nano-hole as a new effective nonlinear element for third-harmonic generation

International Nuclear Information System (INIS)

Melentiev, P N; Konstantinova, T V; Afanasiev, A E; Balykin, V I; Kuzin, A A; Baturin, A S; Tausenev, A V; Konyaschenko, A V

2013-01-01

In this letter, we report on a particularly strong optical nonlinearity at the nanometer scale in aluminum. A strong optical nonlinearity of the third order was demonstrated on a single nanoslit. Single nanoslits of different aspect ratio were excited by a laser pulse (120 fs) at the wavelength 1.5 μm, leading predominantly to third-harmonic generation (THG). It has been shown that strong surface plasmon resonance in a nanoslit allows the realization of an effective nanolocalized source of third-harmonic radiation. We show also that a nanoslit in a metal film has a significant advantage in nonlinear processes over its Babinet complementary nanostructure (nanorod): the effective abstraction of heat in a film with a slit makes it possible to use much higher laser radiation intensities. (letter)

Wave function for time-dependent harmonically confined electrons in a time-dependent electric field.

Science.gov (United States)

Li, Yu-Qi; Pan, Xiao-Yin; Sahni, Viraht

2013-09-21

The many-body wave function of a system of interacting particles confined by a time-dependent harmonic potential and perturbed by a time-dependent spatially homogeneous electric field is derived via the Feynman path-integral method. The wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schrödinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the Harmonic Potential Theorem wave function for the case of the time-independent harmonic confining potential.

Explicit formulas for generalized harmonic perturbations of the infinite quantum well with an application to Mathieu equations

International Nuclear Information System (INIS)

García-Ravelo, J.; Trujillo, A. L.; Schulze-Halberg, A.

2012-01-01

We obtain explicit formulas for perturbative corrections of the infinite quantum well model. The formulas we obtain are based on a class of matrix elements that we construct by means of two-parameter ladder operators associated with the infinite quantum well system. Our approach can be used to construct solutions to Schrödinger-type equations that involve generalized harmonic perturbations of their potentials, such as cosine powers, Fourier series, and more general functions. As a particular case, we obtain characteristic values for odd periodic solutions of the Mathieu equation.

Explicit formulas for generalized harmonic perturbations of the infinite quantum well with an application to Mathieu equations

Energy Technology Data Exchange (ETDEWEB)

Garcia-Ravelo, J.; Trujillo, A. L. [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, Unidad Profesional Adolfo Lopez Mateos, Zacatenco, 07738 Mexico D.F. (Mexico); Schulze-Halberg, A. [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary, Indiana 46408 (United States)

2012-10-15

We obtain explicit formulas for perturbative corrections of the infinite quantum well model. The formulas we obtain are based on a class of matrix elements that we construct by means of two-parameter ladder operators associated with the infinite quantum well system. Our approach can be used to construct solutions to Schroedinger-type equations that involve generalized harmonic perturbations of their potentials, such as cosine powers, Fourier series, and more general functions. As a particular case, we obtain characteristic values for odd periodic solutions of the Mathieu equation.

Harmonic and static susceptibilities of YBa2Cu3O7

International Nuclear Information System (INIS)

Ishida, T.; Goldfarb, R.B.; Okayasu, S.; Kazumata, Y.; Franz, J.; Arndt, T.; Schauer, W.

1993-01-01

Intergranular properties of the sintered superconductor YBa 2 Cu 3 O 7 have been studied in terms of complex harmonic magnetic susceptibility χ n χ n ' - iχ n '' (n integer) as well as DC susceptibility χ dc . As functions of temperature T, χ 1 ' and χ 1 '' depend on both the AC magnetic-field amplitude H ac and the magnitude of a superimposed DC field H dc . Only odd-harmonic susceptibilities are observed below the critical temperature, T c , for zero H dc while both odd and even harmonics are observed for nonzero H dc . With T constant, odd-harmonic susceptibilities are even functions of H dc , whereas even-harmonic susceptibilities are odd functions of H dc . Experimental intergranular characteristics of χ n ' and χ n '' are in good agreement with theoretical predictions from a simplified Kim model of magnetization. In contrast, even-harmonic susceptibilities measured for a GdBa 2 Cu 3 O 7 thin film and an YBa 2 Cu 3 O 7 single crystal are not prominent due to missing weak links, whereas odd-harmonic susceptibilities are remarkable. A survey of several models for the harmonic response of superconductors is presented. The DC susceptibility curve for the zero-field-cooled YBa 2 Cu 3 O 7 sample, χ ZFC (T), has a two-step structure arising from intra- and inter-granular components, similar to χ 1 '. DC susceptibility measured upon warming, χ FCW (T), shows a negative peak near T c for the sample cooled rapidly in small DC fields. DC susceptibility measured upon cooling, χ FCC (T), does not show a peak. A negative peak is not seen in measurements on a powdered sample. The negative peak can be explained by intergranular flux depinning upon warming. (orig.)

Second and third harmonic generation associated to infrared transitions in a Morse quantum well under applied electric and magnetic fields

Science.gov (United States)

Restrepo, R. L.; Kasapoglu, E.; Sakiroglu, S.; Ungan, F.; Morales, A. L.; Duque, C. A.

2017-09-01

The effects of electric and magnetic fields on the second and third harmonic generation coefficients in a Morse potential quantum well are theoretically studied. The energy levels and corresponding wave functions are obtained by solving the Schrödinger equation for the electron in the parabolic band scheme and effective mass approximations and the envelope function approach. The results show that both the electric and the magnetic fields have significant influence on the magnitudes and resonant peak energy positions of the second and third harmonic generation responses. In general, the Morse potential profile becomes wider and shallower as γ -parameter increases and so the energies of the bound states will be functions of this parameter. Therefore, we can conclude that the effects of the electric and magnetic fields can be used to tune and control the optical properties of interest in the range of the infrared electromagnetic spectrum.

Zeta functions for the spectrum of the non-commutative harmonic oscillators

CERN Document Server

Ichinose, T

2004-01-01

This paper investigates the spectral zeta function of the non-commutative harmonic oscillator studied in \\cite{PW1, 2}. It is shown, as one of the basic analytic properties, that the spectral zeta function is extended to a meromorphic function in the whole complex plane with a simple pole at $s=1$, and further that it has a zero at all non-positive even integers, i.e. at $s=0$ and at those negative even integers where the Riemann zeta function has the so-called trivial zeros. As a by-product of the study, both the upper and the lower bounds are also given for the first eigenvalue of the non-commutative harmonic oscillator.

Omega-Harmonic Functions and Inverse Conductivity Problems on Networks

National Research Council Canada - National Science Library

Berenstein, Carlos A; Chung, Soon-Yeong

2003-01-01

.... To do this, they introduce an elliptic operator DELTA omega and an omega-harmonic function on the graph, with its physical interpretation being the diffusion equation on the graph, which models an electric network...

Dual-function photonic integrated circuit for frequency octo-tupling or single-side-band modulation.

Science.gov (United States)

Hasan, Mehedi; Maldonado-Basilio, Ramón; Hall, Trevor J

2015-06-01

A dual-function photonic integrated circuit for microwave photonic applications is proposed. The circuit consists of four linear electro-optic phase modulators connected optically in parallel within a generalized Mach-Zehnder interferometer architecture. The photonic circuit is arranged to have two separate output ports. A first port provides frequency up-conversion of a microwave signal from the electrical to the optical domain; equivalently single-side-band modulation. A second port provides tunable millimeter wave carriers by frequency octo-tupling of an appropriate amplitude RF carrier. The circuit exploits the intrinsic relative phases between the ports of multi-mode interference couplers to provide substantially all the static optical phases needed. The operation of the proposed dual-function photonic integrated circuit is verified by computer simulations. The performance of the frequency octo-tupling and up-conversion functions is analyzed in terms of the electrical signal to harmonic distortion ratio and the optical single side band to unwanted harmonics ratio, respectively.

A Novel Method for the Current Harmonic Elimination of Industrial Power System Using Single Tuned Shunt Passive Filter

Directory of Open Access Journals (Sweden)

Mansoor Ahmed Soomro

2012-01-01

Full Text Available The automation of IPS (Industrial Power System has brought about several advantages of increased productivity and efficiency but it suffers from incompatible problems of overheating, noise, complexity etc, which disturb its smooth and fault tolerant implication. When the resonance condition is reached, these effects become detrimental and disturb the whole power system. The purpose of this research work is to include single tuned shunt type passive filter for harmonic elimination of the components used in industrial power system. For this purpose, MATLAB simulation using sim Power system tool has been used to analyze the effects of current harmonics. Third harmonic effects have been removed by the addition of six pulse converter technique. The simulation results show that implication of single tuned shunt (parallel connected passive filter removes effects of succeeding order current harmonics i.e. fifth, seventh and eleventh etc. which are causing substantial damage to industrial power system. The effects of current harmonics can be solved by installing without and with the application of proposed filter. Further, it is observed that these filters contribute in reduction of THD (Total Harmonic Current Distortion followed by improvement in power factor. These results are taken considering limits of IEEE 519-1992 standards.

Spherical Harmonic Analysis of Particle Velocity Distribution Function: Comparison of Moments and Anisotropies using Cluster Data

Science.gov (United States)

Gurgiolo, Chris; Vinas, Adolfo F.

2009-01-01

This paper presents a spherical harmonic analysis of the plasma velocity distribution function using high-angular, energy, and time resolution Cluster data obtained from the PEACE spectrometer instrument to demonstrate how this analysis models the particle distribution function and its moments and anisotropies. The results show that spherical harmonic analysis produced a robust physical representation model of the velocity distribution function, resolving the main features of the measured distributions. From the spherical harmonic analysis, a minimum set of nine spectral coefficients was obtained from which the moment (up to the heat flux), anisotropy, and asymmetry calculations of the velocity distribution function were obtained. The spherical harmonic method provides a potentially effective "compression" technique that can be easily carried out onboard a spacecraft to determine the moments and anisotropies of the particle velocity distribution function for any species. These calculations were implemented using three different approaches, namely, the standard traditional integration, the spherical harmonic (SPH) spectral coefficients integration, and the singular value decomposition (SVD) on the spherical harmonic methods. A comparison among the various methods shows that both SPH and SVD approaches provide remarkable agreement with the standard moment integration method.

Q-switching and efficient harmonic generation from a single-mode LMA photonic bandgap rod fiber laser

DEFF Research Database (Denmark)

Laurila, Marko; Saby, Julien; Alkeskjold, Thomas T.

2011-01-01

We demonstrate a Single-Mode (SM) Large-Mode-Area (LMA) ytterbium-doped PCF rod fiber laser with stable and close to diffraction limited beam quality with 110W output power. Distributed-Mode-Filtering (DMF) elements integrated in the cladding of the rod fiber provide a robust spatial mode...... with a Mode-Field-Diameter (MFD) of 59 mu m. We further demonstrate high pulse energy Second-Harmonic-Generation (SHG) and Third Harmonic Generation (THG) using a simple Q-switched single-stage rod fiber laser cavity architecture reaching pulse energies up to 1mJ at 515nm and 0.5mJ at 343nm. (C) 2011 Optical...

Pascu-Type Harmonic Functions with Positive Coefficients Involving Salagean Operator

Directory of Open Access Journals (Sweden)

K. Vijaya

2014-01-01

harmonic functions which are orientation preserving and univalent in the open unit disc. Among the results presented in this paper including the coeffcient bounds, distortion inequality, and covering property, extreme points, certain inclusion results, convolution properties, and partial sums for this generalized class of functions are discussed.

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

Science.gov (United States)

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

2011-08-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-08-15

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

Time-frequency analysis and harmonic Gaussian functions

International Nuclear Information System (INIS)

Ranaivoson, R.T.R; Raoelina Andriambololona; Hanitriarivo, R.

2013-01-01

A method for time-frequency analysis is given. The approach utilizes properties of Gaussian distribution, properties of Hermite polynomials and Fourier analysis. We begin by the definitions of a set of functions called Harmonic Gaussian Functions. Then these functions are used to define a set of transformations, noted Τ n , which associate to a function ψ, of the time variable t, a set of functions Ψ n which depend on time, frequency and frequency (or time) standard deviation. Some properties of the transformations Τ n and the functions Ψ n are given. It is proved in particular that the square of the modulus of each function Ψ n can be interpreted as a representation of the energy distribution of the signal, represented by the function ψ, in the time-frequency plane for a given value of the frequency (or time) standard deviation. It is also shown that the function ψ can be recovered from the functions Ψ n .

High-order harmonic conversion efficiency in helium

International Nuclear Information System (INIS)

Crane, J.K.

1992-01-01

Calculated results are presented for the energy, number of photons, and conversion efficiency for high-order harmonic generation in helium. The results show the maximum values that we should expect to achieve experimentally with our current apparatus and the important parameters for scaling this source to higher output. In the desired operating regime where the coherence length, given by L coh =πb/(q-1), is greater than the gas column length, l, the harmonic output can be summarized by a single equation: N q =[(π z n z b 3 τ q |d q | z )/4h]{(p/q)(2l/b) z }. N q - numbers of photons of q-th harmonic; n - atom density; b - laser confocal parameter; τ q - pulse width of harmonic radiation; q - harmonic order; p - effective order of nonlinearity. (Note the term in brackets, the phase-matching function, has been separated from the rest of the expression in order to be consistent with the relevant literature)

Local gradient estimate for harmonic functions on Finsler manifolds

OpenAIRE

Xia, Chao

2013-01-01

In this paper, we prove the local gradient estimate for harmonic functions on complete, noncompact Finsler measure spaces under the condition that the weighted Ricci curvature has a lower bound. As applications, we obtain Liouville type theorem on Finsler manifolds with nonnegative Ricci curvature.

Single-shot fluctuations in waveguided high-harmonic generation

NARCIS (Netherlands)

Goh, S.J.; Tao, Y.; van der Slot, Petrus J.M.; Bastiaens, Hubertus M.J.; Herek, Jennifer Lynn; Biedron, S.G.; Danailov, M.B.; Milton, S.V.; Boller, Klaus J.

2015-01-01

For exploring the application potential of coherent soft x-ray (SXR) and extreme ultraviolet radiation (XUV) provided by high-harmonic generation, it is important to characterize the central output parameters. Of specific importance are pulse-to-pulse (shot-to-shot) fluctuations of the high-harmonic

Output pressure and harmonic characteristics of a CMUT as function of bias and excitation voltage

DEFF Research Database (Denmark)

Lei, Anders; Diederichsen, Søren Elmin; Hansen, Sebastian Molbech

2015-01-01

of the transmitted signal. The generation of intrinsic harmonics by the CMUT can be minimized by decreasing the excitation signal. This, however, leads to lower fundamental pressure which limits the desired generation of harmonics in the medium. This work examines the output pressure and harmonic characteristics...... of a CMUT as function of bias and excitation voltage. The harmonic to fundamental ratio of the surface pressures declines for decreasing excitation voltage and increasing bias voltage. The ratio, however, becomes unchanged for bias levels close to the pull-in voltage. The harmonic limitations of the CMUT...

Single-particle Glauber matrix elements

International Nuclear Information System (INIS)

Oset, E.; Strottman, D.

1983-01-01

The single-particle matrix elements of the Glauber profile function are tabulated for harmonic oscillator single-particle wave functions. The tables are presented in such a manner as to be applicable if the hadron--nucleon elementary scattering amplitude is specified by either a partial wave expansion or a Gaussian in momentum transfer squared. The table is complete through the 1 g/sub 9/2/ orbital and contains entries for the 3s/sub 1/2/ orbital for use if realistic wave functions are expanded in terms of harmonic oscillator functions

CURRENT TRENDS IN TAX HARMONIZATION AND COMPETITION WITHIN THE EUROPEAN UNION

Directory of Open Access Journals (Sweden)

Gherman Adela-Teodora

2010-12-01

Full Text Available This article treats on the fiscal harmonization process within the European Union being indispensable for assuring loyalty in the competition on its single market, given the fact that different system of taxation had direct and powerful impact on the prices level and on chosing the location for production and distribution activities. Both direct and indirect taxation distort the four fundamental freedoms of the single market. Most of the European Unions regulations regarding fiscal harmonization resemble to the Directive regarding especially the indirect taxes: VAT, Excises. The fiscal reforms from the member states have to be conceived in such a manner that they take into account the necessity of fiscal harmonization on EU level, creating a reasonable compromise between each country's sovereignty and the desideratum of removing fiscal barriers from the normal functioning of the single market.

Harmonic generation and flux quantization in granular superconductors

International Nuclear Information System (INIS)

Lam, Q.H.; Jeffries, C.D.

1989-01-01

Simple dynamical models of granular superconductors are used to compute the generation of harmonic power in ac and dc magnetic fields. In zero order, the model is a single superconducting loop, with or without a weak link. The sample-average power is predicted by averaging over suitable distribution functions for loop areas and orientations in a dc magnetic field. In a first-order model, inductance and resistance are also included. In all models the power at high harmonics shows strikingly sharp dips periodic in the dc field, revealing flux quantization in the prototype loops

Phase-locked high-order-harmonic and sub-100-as pulse generation from stretched molecules

International Nuclear Information System (INIS)

Lan Pengfei; Lu Peixiang; Cao Wei; Wang Xinlin; Yang Guang

2006-01-01

High harmonic generation from diatomic molecules in a linearly polarized intense laser field is investigated and the emission time of the harmonics is discussed with the time-frequency analysis method. It is shown that high harmonic generation from molecules at equilibrium distance is similar to that from atoms. Only the harmonics in the cutoff are synchronized, i.e., well phase-locked, whereas the other harmonics are not phase-locked. For the molecule stretched well beyond its equilibrium distance, the harmonics exhibit distinct time-frequency characteristics. The harmonic spectrum can be extended to I p +8U p , where I p and U p are the ionization and ponderomotive potential, and the harmonics with energies below I p +3.17U p are not phase-locked and the harmonics with energies beyond I p +3.17U p are well phase-locked. Thus a large range of harmonics which are well phase-locked are produced, and a train of clean attosecond (as) pulses with a single 90-as pulse in each half optical cycle can be generated with a multicycle laser pulse. Using a few-cycle laser pulse, an isolated attosecond pulse with a duration of about 95 as is obtained

Structural relations of harmonic sums and Mellin transformers at weight w=6

Energy Technology Data Exchange (ETDEWEB)

Bluemlein, Johannes

2009-01-15

We derive the structural relations between nested harmonic sums and the corresponding Mellin transforms of Nielsen integrals and harmonic polylogarithms at weight w=6. They emerge in the calculations of massless single-scale quantities in QED and QCD, such as anomalous dimensions and Wilson coefficients, to 3- and 4-loop order. We consider the set of the multiple harmonic sums at weight six without index {l_brace}-1{r_brace}. This restriction is sufficient for all known physical cases. The structural relations supplement the algebraic relations, due to the shuffle product between harmonic sums, studied earlier. The original amount of 486 possible harmonic sums contributing at weight w=6 reduces to 99 sums with no index {l_brace}-1{r_brace}. Algebraic and structural relations lead to a further reduction to 20 basic functions. These functions supplement the set of 15 basic functions up to weight w=5 derived formerly. We line out an algorithm to obtain the analytic representation of the basic sums in the complex plane. (orig.)

Special values of the spectral zeta function of the non-commutative harmonic oscillator and confluent Heun equations

CERN Document Server

Ichinose, T

2004-01-01

We study the special values at $s=2$ and $3$ of the spectral zeta function $\\zeta_Q(s)$ of the non-commutative harmonic oscillator $Q(x,D_x)$ introduced in \\cite{PW1, 2}. It is shown that the series defining $\\zeta_Q(s)$ converges absolutely for Re $s>1$ and further the respective values $\\zeta_Q(2)$ and $\\zeta_Q(3)$ are represented essentially by contour integrals of the solutions, respectively, of a singly confluent Heun's ordinary differential equation and of exactly the same but an inhomogeneous equation. As a by-product of these results, we obtain integral representations of the solutions of these equations by rational functions. \\par\

A Synchronization Scheme for Single-Phase Grid-Tied Inverters Under Harmonic Distortion and Grid Disturbances

DEFF Research Database (Denmark)

Hadjidemetriou, Lenos; Kyriakides, Elias; Yang, Yongheng

2016-01-01

Synchronization is a crucial aspect in grid-tied systems, including single-phase photovoltaic inverters, and it can affect the overall performance of the system. Among prior-art synchronization schemes, the Multi Harmonic Decoupling Cell Phase-Locked Loop (MHDC-PLL) presents a fast response under...

Accuracy of finite-difference harmonic frequencies in density functional theory.

Science.gov (United States)

Liu, Kuan-Yu; Liu, Jie; Herbert, John M

2017-07-15

Analytic Hessians are often viewed as essential for the calculation of accurate harmonic frequencies, but the implementation of analytic second derivatives is nontrivial and solution of the requisite coupled-perturbed equations engenders a sizable memory footprint for large systems, given that these equations are not required for energy and gradient calculations in density functional theory. Here, we benchmark the alternative approach to harmonic frequencies based on finite differences of analytic first derivatives, a procedure that is amenable to large-scale parallelization. Not only for absolute frequencies but also for isotopic and conformer-dependent frequency shifts in flexible molecules, we find that the finite-difference approach exhibits mean errors numbers. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Analyzing correlation functions with tesseral and Cartesian spherical harmonics

International Nuclear Information System (INIS)

Danielewicz, Pawel; Pratt, Scott

2007-01-01

The dependence of interparticle correlations on the orientation of particle relative momentum can yield unique information on the space-time features of emission in reactions with multiparticle final states. In the present paper, the benefits of a representation and analysis of the three-dimensional correlation information in terms of surface spherical harmonics is presented. The harmonics include the standard complex tesseral harmonics and the real Cartesian harmonics. Mathematical properties of the lesser known Cartesian harmonics are illuminated. The physical content of different angular harmonic components in a correlation is described. The resolving power of different final-state effects with regard to determining angular features of emission regions is investigated. The considered final-state effects include identity interference, strong interactions, and Coulomb interactions. The correlation analysis in terms of spherical harmonics is illustrated with the cases of Gaussian and blast-wave sources for proton-charged meson and baryon-baryon pairs

Linear and nonlinear Biot waves in a noncohesive granular medium slab: transfer function, self-action, second harmonic generation.

Science.gov (United States)

Legland, J-B; Tournat, V; Dazel, O; Novak, A; Gusev, V

2012-06-01

Experimental results are reported on second harmonic generation and self-action in a noncohesive granular medium supporting wave energy propagation both in the solid frame and in the saturating fluid. The acoustic transfer function of the probed granular slab can be separated into two main frequency regions: a low frequency region where the wave propagation is controlled by the solid skeleton elastic properties, and a higher frequency region where the behavior is dominantly due to the air saturating the beads. Experimental results agree well with a recently developed nonlinear Biot wave model applied to granular media. The linear transfer function, second harmonic generation, and self-action effect are studied as a function of bead diameter, compaction step, excitation amplitude, and frequency. This parametric study allows one to isolate different propagation regimes involving a range of described and interpreted linear and nonlinear processes that are encountered in granular media experiments. In particular, a theoretical interpretation is proposed for the observed strong self-action effect.

On the spherical harmonic expansion of the neutron angular distribution function

Energy Technology Data Exchange (ETDEWEB)

Depken, Sven

1959-03-15

The neutron (one-velocity) angular distribution function is expanded in terms of spherical harmonic tensors. The solution to the equations of the moments is given explicitly and the result is applied to the plane, spherical and cylinder symmetrical cases.

On the spherical harmonic expansion of the neutron angular distribution function

International Nuclear Information System (INIS)

Depken, Sven

1959-03-01

The neutron (one-velocity) angular distribution function is expanded in terms of spherical harmonic tensors. The solution to the equations of the moments is given explicitly and the result is applied to the plane, spherical and cylinder symmetrical cases

Hyper-spherical harmonics and anharmonics in m-dimensional space

International Nuclear Information System (INIS)

Shojaei, M.R.; Rajabi, A.A.; Hasanabadi, H.

2008-01-01

In quantum mechanics the hyper-spherical method is one of the most well-established and successful computational tools. The general theory of harmonic polynomials and hyper-spherical harmonics is of central importance in this paper. The interaction potential V is assumed to depend on the hyper-radius ρ only where ρ is the function of the Jacobi relative coordinate x 1 , x 2 ,…, x n which are functions of the particles' relative positions. (author)

Second-harmonic generation in second-harmonic fiber Bragg gratings.

Science.gov (United States)

Steel, M J; de Sterke, C M

1996-06-20

We consider the production of second-harmonic light in gratings resonant with the generated field, through a Green's function approach. We recover some standard results and obtain new limits for the uniform grating case. With the extension to nonuniform gratings, we find the Green's function for the second harmonic in a grating with an arbitrary phase shift at some point. We then obtain closed form approximate expressions for the generated light for phase shifts close to π/2 and at the center of the grating. Finally, comparing the uniform and phase-shifted gratings with homogeneous materials, we discuss the enhancement in generated light and the bandwidth over which it occurs, and the consequences for second-harmonic generation in optical fiber Bragg gratings.

Imaging theory of nonlinear second harmonic and third harmonic generations in confocal microscopy

Institute of Scientific and Technical Information of China (English)

TANG Zhilie; XING Da; LIU Songhao

2004-01-01

The imaging theory of nonlinear second harmonic generation (SHG) and third harmonic generation (THG) in confocal microscopy is presented in this paper. The nonlinear effect of SHG and THG on the imaging properties of confocal microscopy has been analyzed in detail by the imaging theory. It is proved that the imaging process of SHG and THG in confocal microscopy, which is different from conventional coherent imaging or incoherent imaging, can be divided into two different processes of coherent imaging. The three-dimensional point spread functions (3D-PSF) of SHG and THG confocal microscopy are derived based on the nonlinear principles of SHG and THG. The imaging properties of SHG and THG confocal microscopy are discussed in detail according to its 3D-PSF. It is shown that the resolution of SHG and THG confocal microscopy is higher than that of single-and two-photon confocal microscopy.

Single well techniques

International Nuclear Information System (INIS)

Drost, W.

1983-01-01

The single well technique method includes measurement of parameters of groundwater flow in saturated rock. For determination of filtration velocity the dilution of radioactive tracer is measured, for direction logging the collimeter is rotated in the probe linked with the compass. The limiting factor for measurement of high filtration velocities is the occurrence of turbulent flow. The single well technique is used in civil engineering projects, water works and subsurface drainage of liquid waste from disposal sites. The radioactive tracer method for logging the vertical fluid movement in bore-holes is broadly used in groundwater survey and exploitation. (author)

Analysis of single-degree-of-freedom piezoelectric energy harvester with stopper by incremental harmonic balance method

Science.gov (United States)

Zhao, Dan; Wang, Xiaoman; Cheng, Yuan; Liu, Shaogang; Wu, Yanhong; Chai, Liqin; Liu, Yang; Cheng, Qianju

2018-05-01

Piecewise-linear structure can effectively broaden the working frequency band of the piezoelectric energy harvester, and improvement of its research can promote the practical process of energy collection device to meet the requirements for powering microelectronic components. In this paper, the incremental harmonic balance (IHB) method is introduced for the complicated and difficult analysis process of the piezoelectric energy harvester to solve these problems. After obtaining the nonlinear dynamic equation of the single-degree-of-freedom piecewise-linear energy harvester by mathematical modeling and the equation is solved based on the IHB method, the theoretical amplitude-frequency curve of open-circuit voltage is achieved. Under 0.2 g harmonic excitation, a piecewise-linear energy harvester is experimentally tested by unidirectional frequency-increasing scanning. The results demonstrate that the theoretical and experimental amplitudes have the same trend, and the width of the working band with high voltage output are 4.9 Hz and 4.7 Hz, respectively, and the relative error is 4.08%. The open-output peak voltage are 21.53 V and 18.25 V, respectively, and the relative error is 15.23%. Since the theoretical value is consistent with the experimental results, the theoretical model and the incremental harmonic balance method used in this paper are suitable for solving single-degree-of-freedom piecewise-linear piezoelectric energy harvester and can be applied to further parameter optimized design.

A pretandem harmonic buncher

International Nuclear Information System (INIS)

Lin, Qui-xun; Van Wechel, T.D.

1987-01-01

A single gap harmonic buncher has been constructed as a pretandem buncher. Over 85% of a proton dc beam has been bunched into pulses. The width (fwhm) of the pulses is 0.7 ns. The buncher is based on that built at Argonne. Changes were made to the buncher's configuration so that the buncher could be tuned to the desired four harmonic frequencies. A method of calibrating and setting the relative phases and amplitudes of the four harmonic frequencies has been used to obtain an optimum sawtooth-like bunching waveform

High-harmonic generation in a dense medium

International Nuclear Information System (INIS)

Strelkov, V.V.; Platonenko, V.T.; Becker, A.

2005-01-01

The high-harmonic generation in a plasma or gas under conditions when the single-atom response is affected by neighboring ions or atoms of the medium is studied theoretically. We solve numerically the three-dimensional Schroedinger equation for a single-electron atom in the combined fields of the neighboring particles and the laser, and average the results over different random positions of the particles using the Monte Carlo method. Harmonic spectra are calculated for different medium densities and laser intensities. We observe a change of the harmonic properties due to a random variation of the harmonic phase induced by the field of the medium, when the medium density exceeds a certain transition density. The transition density is found to depend on the harmonic order, but it is almost independent of the fundamental intensity. It also differs for the two (shorter and longer) quantum paths. The latter effect leads for ionic densities in the transition regime to a narrowing of the harmonic lines and a shortening of the attosecond pulses generated using a group of harmonics

Intelligent harmonic load model based on neural networks

Science.gov (United States)

Ji, Pyeong-Shik; Lee, Dae-Jong; Lee, Jong-Pil; Park, Jae-Won; Lim, Jae-Yoon

2007-12-01

In this study, we developed a RBFNs(Radial Basis Function Networks) based load modeling method with harmonic components. The developed method implemented by using harmonic information as well as fundamental frequency and voltage which are essential input factors in conventional method. Thus, the proposed method makes it possible to effectively estimate load characteristics in power lines with harmonics. The RBFNs have certain advantage such as simple structure and rapid computation ability compared with multilayer perceptron which is extensively applied for load modeling. To show the effectiveness, the proposed method has been intensively tested with various dataset acquired under the different frequency and voltage and compared it with conventional methods such as polynominal 2nd equation method, MLP and RBF without considering harmonic components.

Coherent harmonic production using a two-section undulator FEL

Energy Technology Data Exchange (ETDEWEB)

Jaroszynski, D.A. [Commissariat a l`Energie, Bruyeres-le-Chatel (France); Prazeres, R.; Glotin, F. [Centre Universitaire Paris-Sud (France)] [and others

1995-12-31

We present measurements and a theoretical analysis of a new method of generating harmonic radiation in a free-electron laser oscillator with a two section undulator in a single optical cavity. To produce coherent harmonic radiation the undulator is arranged so that the downstream undulator section resonance frequency matches a harmonic of the upstream undulator. Both the fundamental and the harmonic optical fields evolve in the same optical cavity and are coupled out with different extraction fractions using a hole in one of the cavity mirrors. We present measurements that show that the optical power at the second and third harmonic can be enhanced by more than an order of magnitude in this fundamental/harmonic configuration. We compare the production of harmonic radiation of a two sectioned fundamental/harmonic undulator with that produced from a FEL operating at its highest efficiency with a step-tapered undulator, where the bunching at the end of the first section is very large. We examine, the dependence of the harmonic power on the intracavity power by adjusting the optical cavity desynchronism, {delta}L. We also examine the evolution of the fundamental and harmonic powers as a function of cavity roundtrip number to evaluate the importance of the small signal gain at the harmonic. We compare our measurements with predictions of a multi-electron numerical model that follows the evolution of fundamental and harmonic power to saturation. This fundamental/harmonic mode, of operation of the FEL may have useful applications in the production of coherent X-ray and VUV radiation, a spectral range where high reflectivity optical cavity mirrors are difficult or impossible to manufacture.

Atto second high harmonic sources

International Nuclear Information System (INIS)

Nam, Chang Hee

2008-01-01

High harmonic generation is a powerful method to produce attosecond pulses. The high harmonics, emitted from atoms driven by intense femtosecond laser pulses, can from an attosecond pulse train with equally spaced harmonic spectrum or an isolated single attosecond pulse with broad continuum spectrum. Using high power femtosecond laser technology developed at CXRC, we have investigated the spectral and temporal characteristics of high harmonics obtained from gaseous atoms. The spectral structure of harmonics could be manipulated by controlling laser chirp, and continuous tuning of harmonic wavelengths was achieved. For rigorous temporal characterization of attosecond harmonic pulses a cross correlation technique was applied to the photoionization process by harmonic and IR femtosecond pulses and achieved the complete temporal reconstruction of attosecond pulse trains, revealing the detailed temporal structure of the attosecond chirp by material dispersion. The duration of attosecond high harmonic pulses is usually much longer than that of transform limited pulses due to the inherent chirp originating from the harmonic generation process. The attosecond chirp compensation in the harmonic generation medium itself was demonstrated, thereby realizing the generation of near transform limited attosecond pulses. The interference of attosecond electron wave packets, generated from an atom by attosecond harmonic pulses, will be also presented

A harmonic analysis approach to joint inversion of P-receiver functions and wave dispersion data in high dense seismic profiles

Science.gov (United States)

Molina-Aguilera, A.; Mancilla, F. D. L.; Julià, J.; Morales, J.

2017-12-01

Joint inversion techniques of P-receiver functions and wave dispersion data implicitly assume an isotropic radial stratified earth. The conventional approach invert stacked radial component receiver functions from different back-azimuths to obtain a laterally homogeneous single-velocity model. However, in the presence of strong lateral heterogeneities as anisotropic layers and/or dipping interfaces, receiver functions are considerably perturbed and both the radial and transverse components exhibit back azimuthal dependences. Harmonic analysis methods exploit these azimuthal periodicities to separate the effects due to the isotropic flat-layered structure from those effects caused by lateral heterogeneities. We implement a harmonic analysis method based on radial and transverse receiver functions components and carry out a synthetic study to illuminate the capabilities of the method in isolating the isotropic flat-layered part of receiver functions and constrain the geometry and strength of lateral heterogeneities. The independent of the baz P receiver function are jointly inverted with phase and group dispersion curves using a linearized inversion procedure. We apply this approach to high dense seismic profiles ( 2 km inter-station distance, see figure) located in the central Betics (western Mediterranean region), a region which has experienced complex geodynamic processes and exhibit strong variations in Moho topography. The technique presented here is robust and can be applied systematically to construct a 3-D model of the crust and uppermost mantle across large networks.

Solid-state harmonics beyond the atomic limit.

Science.gov (United States)

Ndabashimiye, Georges; Ghimire, Shambhu; Wu, Mengxi; Browne, Dana A; Schafer, Kenneth J; Gaarde, Mette B; Reis, David A

2016-06-23

Strong-field laser excitation of solids can produce extremely nonlinear electronic and optical behaviour. As recently demonstrated, this includes the generation of high harmonics extending into the vacuum-ultraviolet and extreme-ultraviolet regions of the electromagnetic spectrum. High harmonic generation is shown to occur fundamentally differently in solids and in dilute atomic gases. How the microscopic mechanisms in the solid and the gas differ remains a topic of intense debate. Here we report a direct comparison of high harmonic generation in the solid and gas phases of argon and krypton. Owing to the weak van der Waals interaction, rare (noble)-gas solids are a near-ideal medium in which to study the role of high density and periodicity in the generation process. We find that the high harmonic generation spectra from the rare-gas solids exhibit multiple plateaus extending well beyond the atomic limit of the corresponding gas-phase harmonics measured under similar conditions. The appearance of multiple plateaus indicates strong interband couplings involving multiple single-particle bands. We also compare the dependence of the solid and gas harmonic yield on laser ellipticity and find that they are similar, suggesting the importance of electron-hole recollision in these solids. This implies that gas-phase methods such as polarization gating for attosecond pulse generation and orbital tomography could be realized in solids.

1.5 W green light generation by single-pass second harmonic generation of a single-frequency tapered diode laser

DEFF Research Database (Denmark)

Jensen, Ole Bjarlin; Andersen, Peter E.; Sumpf, Bernd

2009-01-01

More than 1.5 W of green light at 531 nm is generated by singlepass second harmonic generation in periodically poled MgO:LiNbO3. The pump laser is a high power tapered laser with a distributed Bragg reflector etched in the ridge section of the laser to provide wavelength selectivity. The output...... power of the single-frequency tapered laser is 9.3 W in continuous wave operation. A conversion efficiency of 18.5 % was achieved in the experiments....

High-harmonic generation in a quantum electron gas trapped in a nonparabolic and anisotropic well

Science.gov (United States)

Hurst, Jérôme; Lévêque-Simon, Kévin; Hervieux, Paul-Antoine; Manfredi, Giovanni; Haas, Fernando

2016-05-01

An effective self-consistent model is derived and used to study the dynamics of an electron gas confined in a nonparabolic and anisotropic quantum well. This approach is based on the equations of quantum hydrodynamics, which incorporate quantum and nonlinear effects in an approximate fashion. The effective model consists of a set of six coupled differential equations (dynamical system) for the electric dipole and the size of the electron gas. Using this model we show that: (i) high harmonic generation is related to the appearance of chaos in the phase space, as attested to by related Poincaré sections; (ii) higher order harmonics can be excited efficiently and with relatively weak driving fields by making use of chirped electromagnetic waves.

High Performance Harmonic Isolation By Means of The Single-phase Series Active Filter Employing The Waveform Reconstruction Method

DEFF Research Database (Denmark)

Senturk, Osman Selcuk; Hava, Ahmet M.

2009-01-01

current sampling delay reduction method (SDRM), a single-phase SAF compensated system provides higher harmonic isolation performance and higher stability margins compared to the system using conventional synchronous reference frame based methods. The analytical, simulation, and experimental studies of a 2...

Power quality issues current harmonics

CERN Document Server

Mikkili, Suresh

2015-01-01

Power Quality Issues: Current Harmonics provides solutions for the mitigation of power quality problems related to harmonics. Focusing on active power filters (APFs) due to their excellent harmonic and reactive power compensation in two-wire (single phase), three-wire (three-phase without neutral), and four-wire (three-phase with neutral) AC power networks with nonlinear loads, the text:Introduces the APF technology, describing various APF configurations and offering guidelines for the selection of APFs for specific application considerationsCompares shunt active filter (SHAF) control strategi

Time profile of harmonics generated by a single atom in a strong electromagnetic field

International Nuclear Information System (INIS)

Antoine, P.; Piraux, B.; Maquet, A.

1995-01-01

We show that the time profile of the harmonics emitted by a single atom exposed to a strong electromagnetic field may be obtained through a wavelet or a Gabor analysis of the acceleration of the atomic dipole. This analysis is extremely sensitive to the details of the dynamics and sheds some light on the competition between the atomic excitation or ionization processes and photon emission. For illustration we study the interaction of atomic hydrogen with an intense laser pulse

Liquid Observation Well (LOW) Functional Design

International Nuclear Information System (INIS)

Paul, B.

1995-01-01

This document presents the Functional Design Criteria for installing Liquid Observation Wells (LOWS) into single-shell tanks containing either ferrocyanide or organic waste. The LOWs will be designed to accommodate the deployment of gamma, neutron, and electromagnetic induction probes and to interface with the existing tank structure and environment

Probabilistic Harmonic Analysis on Distributed Photovoltaic Integration Considering Typical Weather Scenarios

Science.gov (United States)

Bin, Che; Ruoying, Yu; Dongsheng, Dang; Xiangyan, Wang

2017-05-01

Distributed Generation (DG) integrating to the network would cause the harmonic pollution which would cause damages on electrical devices and affect the normal operation of power system. On the other hand, due to the randomness of the wind and solar irradiation, the output of DG is random, too, which leads to an uncertainty of the harmonic generated by the DG. Thus, probabilistic methods are needed to analyse the impacts of the DG integration. In this work we studied the harmonic voltage probabilistic distribution and the harmonic distortion in distributed network after the distributed photovoltaic (DPV) system integrating in different weather conditions, mainly the sunny day, cloudy day, rainy day and the snowy day. The probabilistic distribution function of the DPV output power in different typical weather conditions could be acquired via the parameter identification method of maximum likelihood estimation. The Monte-Carlo simulation method was adopted to calculate the probabilistic distribution of harmonic voltage content at different frequency orders as well as the harmonic distortion (THD) in typical weather conditions. The case study was based on the IEEE33 system and the results of harmonic voltage content probabilistic distribution as well as THD in typical weather conditions were compared.

Influence of micro- and macro-processes on the high-order harmonic generation in laser-produced plasma

Energy Technology Data Exchange (ETDEWEB)

Ganeev, R. A., E-mail: rashid-ganeev@mail.ru [Ophthalmology and Advanced Laser Medical Center, Saitama Medical University, 38 Morohongo, Moroyama-machi, Iruma-gun, Saitama 350-0495 (Japan); Physical Department, Voronezh State University, Voronezh 394006 (Russian Federation)

2016-03-21

We compare the resonance-induced enhancement of single harmonic and the quasi-phase-matching-induced enhancement of the group of harmonics during propagation of the tunable mid-infrared femtosecond pulses through the perforated laser-produced indium plasma. We show that the enhancement of harmonics using the macro-process of quasi-phase-matching is comparable with the one using micro-process of resonantly enhanced harmonic. These studies show that joint implementation of the two methods of the increase of harmonic yield could be a useful tool for generation of strong short-wavelength radiation in different spectral regions. We compare these effects in indium, as well as in other plasmas.

Relativistic corrections to one-particle neutron levels in the harmonic oscillator well

International Nuclear Information System (INIS)

Yanavichyus, A.I.

1983-01-01

Relativistic corrections to mass and potential energy for one-particle levels in the harmonic oscillator well are calculated in the first approximation of the perturbation theory. These corrections are, mainly negliqible, but they sharply increase with growth of the head and orbital quantum numbers. For the state 1s the relativistic correction is of the order of 0.01 MeV, and for 3p it is equal to 0.4 MeV. Thus, the relativistic correction for certain states approaches the energy of spin-orbital interactions and it should be taken into account in calculating the energy of one-particle levels

First exit times of harmonically trapped particles: a didactic review

International Nuclear Information System (INIS)

Grebenkov, Denis S

2015-01-01

We revise the classical problem of characterizing first exit times of a harmonically trapped particle whose motion is described by a one- or multidimensional Ornstein–Uhlenbeck process. We start by recalling the main derivation steps of a propagator using Langevin and Fokker–Planck equations. The mean exit time, the moment-generating function and the survival probability are then expressed through confluent hypergeometric functions and thoroughly analyzed. We also present a rapidly converging series representation of confluent hypergeometric functions that is particularly well suited for numerical computation of eigenvalues and eigenfunctions of the governing Fokker–Planck operator. We discuss several applications of first exit times, such as the detection of time intervals during which motor proteins exert a constant force onto a tracer in optical tweezers single-particle tracking experiments; adhesion bond dissociation under mechanical stress; characterization of active periods of trend-following and mean-reverting strategies in algorithmic trading on stock markets; relation to the distribution of first crossing times of a moving boundary by Brownian motion. Some extensions are described, including diffusion under quadratic double-well potential and anomalous diffusion. (topical review)

High-order harmonic and attosecond pulse generation for a few-cycle laser pulse in modulated hollow fibres

International Nuclear Information System (INIS)

Zhang Xiangyun; Sun Zhenrong; Wang Yufeng; Chen Guoliang; Wang Zugeng; Li Ruxin; Zeng Zhinan; Xu Zhizhan

2007-01-01

High harmonic generation from Ar and He atoms by a few-cycle laser pulse in periodic and chirped hollow fibres is investigated theoretically by a self-consistent model. Based on enhanced high harmonics in a periodic hollow fibre, a chirped hollow fibre is proposed to improve quasi-phase matching for the generated harmonics near the cutoff. The results show that the extended and enhanced harmonics near the cutoff are well phase-matched, and a single x-ray pulse with a duration of 279 as in Ar gas and 255 as in He gas can be achieved by frequency synthesizing of high harmonics in the well-selected cutoff bandwidth. The results show that this technique is a potential candidate to generate an intense isolated attosecond pulse in the 'water window' spectrum

Removal of Direct Current Link Harmonic Ripple in Single Phase Voltage Source Inverter Systems Using Supercapacitors

Science.gov (United States)

2016-09-01

Khaligh, “Optimization of sizing and battery cycle life in battery/ultracapacitor hybrid energy storage systems for electric vehicle applications...depth cycling operation in photovoltaic system ,” in 22nd International Conference “Mixed Design of Integrated Circuits and Systems ,” Toruń, Poland...CURRENT LINK HARMONIC RIPPLE IN SINGLE-PHASE VOLTAGE SOURCE INVERTER SYSTEMS USING SUPERCAPACITORS by Gabriel D. Hernandez September 2016

Active control with delay of catastrophic motion and horseshoes chaos in a single well Duffing oscillator

International Nuclear Information System (INIS)

Nana Nbendjo, B.R.; Salissou, Y.; Woafo, P.

2005-01-01

In this paper, the control of escape and Melnikov chaos of an harmonically excited particle from a catastrophic (unbounded) single well phi 4 potential is considered. In the linear limit, the range of the control gain parameter leading to good control is obtained and the effect of time delays on the control force is taken into account. The approximate critical external forcing amplitudes for catastrophe and chaos are obtained by using the energy and Melnikov methods. The control efficiency is found by analysing the behaviour of the external critical forcing amplitude of the controlled system as compared to that of the uncontrolled system

Constant DC-Capacitor Voltage-Control-Based Harmonics Compensation Strategy of Smart Charger for Electric Vehicles in Single-Phase Three-Wire Distribution Feeders

Directory of Open Access Journals (Sweden)

Fuka Ikeda

2017-06-01

Full Text Available This paper discusses harmonic current compensation of the constant DC-capacitor voltage-control (CDCVC-based strategy of smart chargers for electric vehicles (EVs in single-phase three-wire distribution feeders (SPTWDFs under nonlinear load conditions. The basic principle of the CDCVC-based harmonics compensation strategy under nonlinear load conditions is discussed in detail. The instantaneous power flowing into the three-leg pulse-width modulated (PWM rectifier, which performs as a smart charger, shows that the CDCVC-based strategy achieves balanced and sinusoidal source currents with a unity power factor. The CDCVC-based harmonics compensation strategy does not require any calculation blocks of fundamental reactive, unbalanced active, and harmonic currents. Thus, the authors propose a simplified algorithm to compensate for reactive, unbalanced active, and harmonic currents. A digital computer simulation is implemented to confirm the validity and high practicability of the CDCVC-based harmonics compensation strategy using PSIM software. Simulation results demonstrate that balanced and sinusoidal source currents with a unity power factor in SPTWDFs are obtained on the secondary side of the pole-mounted distribution transformer (PMDT during both the battery-charging and discharging operations in EVs, compensating for the reactive, unbalanced active, and harmonic currents.

Schwinger's formula and the partition function for the bosonic and fermionic harmonic oscillators

International Nuclear Information System (INIS)

Albuquerque, L.C. de; Farina, C.; Rabello, S.J.

1994-01-01

We use Schwinger's formula, introduced by himself in the early fifties to compute effective actions for Qed, and recently applied to the Casimir effect, to obtain the partition functions for both the bosonic and fermionic harmonic oscillators. (author)

Topological string in harmonic space and correlation functions in S3 stringy cosmology

International Nuclear Information System (INIS)

Saidi, El Hassan; Sedra, Moulay Brahim

2006-01-01

We develop the harmonic space method for conifold and use it to study local complex deformations of T*S 3 preserving manifestly SL(2,C) isometry. We derive the perturbative manifestly SL(2,C) invariant partition function Z top of topological string B model on locally deformed conifold. Generic n momentum and winding modes of 2D c=1 noncritical theory are described by highest υ (n,0) and lowest components υ (0,n) of SL(2,C) spin s=n2 multiplets (υ (n-k,k) ), 0= α + and V α - . We also derive a dictionary giving the passage from Laurent (Fourier) analysis on T*S 1 (S 1 ) to the harmonic method on T*S 3 (S 3 ). The manifestly SU(2,C) covariant correlation functions of the S 3 quantum cosmology model of Gukov-Saraikin-Vafa are also studied

Accuracy of three-body wave functions obtained with the correlation-function hyperspherical-harmonic method

International Nuclear Information System (INIS)

Haftel, M.I.; Mandelzweig, V.B.

1990-01-01

The local convergence and accuracy of wave functions obtained by direct solution of the Schroedinger equation with the help of the correlation-function hyperspherical-harmonic method are analyzed for ground and excited states of the helium atom and for the ground state of the positronium negative ion. The inclusion of the cusp conditions into the correlation function is shown to be of crucial importance, not only near the coalescence points, but also away from them. The proper inclusion of all cusps yields for the ground state of the helium atom the local wave-function accuracy of about 10 -7 for different interparticle distances. The omission of one of the cusps in the excited helium atom reduces the wave-function precision to 10 -2 near the corresponding coalescence point and to 10 -4 --10 -5 away from it

Second harmonic generation from photonic structured GaN nanowalls

Energy Technology Data Exchange (ETDEWEB)

Soya, Takahiro; Inose, Yuta; Kunugita, Hideyuki; Ema, Kazuhiro; Yamano, Kouji; Kikuchi, Akihiko; Kishino, Katsumi, E-mail: t-soya@sophia.ac.j [Department of Engineering and Applied Sciences, Sophia University 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554 (Japan)

2009-11-15

We observed large enhancement of reflected second harmonic generation (SHG) using the one-dimensional photonic effect in regularly arranged InGaN/GaN single-quantum-well nanowalls. Using the effect when both fundamental and SH resonate with the photonic mode, we obtained enhancement of about 40 times compared with conditions far from resonance.

Coherent states for the time dependent harmonic oscillator: the step function

International Nuclear Information System (INIS)

Moya-Cessa, Hector; Fernandez Guasti, Manuel

2003-01-01

We study the time evolution for the quantum harmonic oscillator subjected to a sudden change of frequency. It is based on an approximate analytic solution to the time dependent Ermakov equation for a step function. This approach allows for a continuous treatment that differs from former studies that involve the matching of two time independent solutions at the time when the step occurs

Analysis of Harmonic Coupling and Stability in Back-to-Back Converter Systems for Wind Turbines using Harmonic State Space (HSS)

DEFF Research Database (Denmark)

Kwon, Jun Bum; Wang, Xiongfei; Bak, Claus Leth

2015-01-01

Understanding about harmonic propagation in wind turbine converter is fundamental to research the influence of these on a large network harmonic distortion. Therefore, the analysis of wind turbine converter harmonic spectrum as well as the influence of converter operating point into the network i...... connected into the large wind farm model to analyze the overall steady-state harmonic as well as harmonic stability. All theoretical modeling and analysis is verified by means of simulation and experimental results.......Understanding about harmonic propagation in wind turbine converter is fundamental to research the influence of these on a large network harmonic distortion. Therefore, the analysis of wind turbine converter harmonic spectrum as well as the influence of converter operating point into the network...... is urgently important issues in harmonic studies on wind farm. However, the conventional modeling procedure and simplified model for controller design are not enough to analyze such complicated systems. Besides, they have many limitations in terms of including a non-linear component, different operating...

Quasilinear ion distribution function during first harmonic ion cyclotron heating

International Nuclear Information System (INIS)

Brambilla, M.

1993-12-01

The quasilinear modification of the ion distribution function during first harmonic ion cyclotron (FHIC) heating is investigated both with a simple already well established analytic one-dimensional approach, and with a new two dimensional steady state solver of the quasilinear kinetic equation, SSFPQL. By accepting to disregard the effects of ion trapping in banana orbits, but including finite Larmor radius effects, the latter code has been made much faster than full surface-averaged codes; yet it can provide most of the relevant information on the suprathermal ion tail produced by this heating method. With SSFPQL we confirm that the one-dimensional model gives fair approximations for global properties of the distribution function, such as the average energy content of the tail and the fusion reactivity. On the other hand the tail is found to be very anisotropic, the increase of the parallel effective temperature being a small fraction of the total energy increase. Information on the anisotropy is essential to study the feedback of the fast ion tail on wave propagation and absorption, which is quite sensitive to the distribution of parallel velocities. The insight gained in the derivation and discussion of this model can be used to build a selfconsistent description of this heating scenario, whose implementation requires only a reasonable numerical effort. (orig.)

Harmonic uniflow engine

Science.gov (United States)

Bennett, Charles L.

2016-03-22

A reciprocating-piston uniflow engine includes a harmonic oscillator inlet valve capable of oscillating at a resonant frequency for controlling the flow of working fluid into the engine. In particular, the inlet valve includes an inlet valve head and a spring arranged together as a harmonic oscillator so that the inlet valve head is moveable from an unbiased equilibrium position to a biased closed position occluding an inlet. When released, the inlet valve head undergoes a single oscillation past the equilibrium position to a maximum open position and returns to a biased return position close to the closed position to choke the flow and produce a pressure drop across the inlet valve causing the inlet valve to close. In other embodiments, the harmonic oscillator arrangement of the inlet valve enables the uniflow engine to be reversibly operated as a uniflow compressor.

Improving Stability and Convergence for Adaptive Radial Basis Function Neural Networks Algorithm. (On-Line Harmonics Estimation Application

Directory of Open Access Journals (Sweden)

Eyad K Almaita

2017-03-01

Keywords: Energy efficiency, Power quality, Radial basis function, neural networks, adaptive, harmonic. Article History: Received Dec 15, 2016; Received in revised form Feb 2nd 2017; Accepted 13rd 2017; Available online How to Cite This Article: Almaita, E.K and Shawawreh J.Al (2017 Improving Stability and Convergence for Adaptive Radial Basis Function Neural Networks Algorithm (On-Line Harmonics Estimation Application.  International Journal of Renewable Energy Develeopment, 6(1, 9-17. http://dx.doi.org/10.14710/ijred.6.1.9-17

Rabi oscillation between states of a coupled harmonic oscillator

International Nuclear Information System (INIS)

Park, Tae Jun

2003-01-01

Rabi oscillation between bound states of a single potential is well known. However the corresponding formula between the states of two different potentials has not been obtained yet. In this work, we derive Rabi formula between the states of a coupled harmonic oscillator which may be used as a simple model for the electron transfer. The expression is similar to typical Rabi formula for a single potential. This result may be used to describe transitions between coupled diabatic potential curves

Pseudo harmonic morphisms on Riemannian polyhedra

International Nuclear Information System (INIS)

Aprodu, M.A.; Bouziane, T.

2004-10-01

The aim of this paper is to extend the notion of pseudo harmonic morphism (introduced by Loubeau) to the case when the source manifold is an admissible Riemannian polyhedron. We define these maps to be harmonic in the sense of Eells-Fuglede and pseudo-horizontally weakly conformal in our sense. We characterize them by means of germs of harmonic functions on the source polyhedron, in the sense of Korevaar-Schoen, and germs of holomorphic functions on the Kaehler target manifold. (author)

Enhancement of Non-Stationary Speech using Harmonic Chirp Filters

DEFF Research Database (Denmark)

Nørholm, Sidsel Marie; Jensen, Jesper Rindom; Christensen, Mads Græsbøll

2015-01-01

In this paper, the issue of single channel speech enhancement of non-stationary voiced speech is addressed. The non-stationarity of speech is well known, but state of the art speech enhancement methods assume stationarity within frames of 20–30 ms. We derive optimal distortionless filters that take...... the non-stationarity nature of voiced speech into account via linear constraints. This is facilitated by imposing a harmonic chirp model on the speech signal. As an implicit part of the filter design, the noise statistics are also estimated based on the observed signal and parameters of the harmonic chirp...... model. Simulations on real speech show that the chirp based filters perform better than their harmonic counterparts. Further, it is seen that the gain of using the chirp model increases when the estimated chirp parameter is big corresponding to periods in the signal where the instantaneous fundamental...

Bessel harmonic analysis and approximation of functions on the half-line

International Nuclear Information System (INIS)

Platonov, Sergei S

2007-01-01

We study problems of approximation of functions on [0,+∞) in the metric of L p with power weight using generalized Bessel shifts. We prove analogues of direct Jackson theorems for the modulus of smoothness of arbitrary order defined in terms of generalized Bessel shifts. We establish the equivalence of the modulus of smoothness and the K-functional. We define function spaces of Nikol'skii-Besov type and describe them in terms of best approximations. As a tool for approximation, we use a certain class of entire functions of exponential type. In this class, we prove analogues of Bernstein's inequality and others for the Bessel differential operator and its fractional powers. The main tool we use to solve these problems is Bessel harmonic analysis

Evaluation on Behavior of Single Block Subject to Harmonic Excitation

International Nuclear Information System (INIS)

Choi, Woo-Seok; Kim, Dong-Ok; Park, Keun-Bae; Lee, Won-Jae

2007-01-01

NHDD(Nuclear Hydrogen Development and Demonstration) project team in KAERI(Korea Atomic Energy Research Institute) has been developing a methodology on the seismic evaluation of VHTR(Very High Temperature Reactor). Roughly, there are a block type and a pebble type reactor in VHTR. In the block type reactor, several blocks are stacked and the stacked blocks are arrayed in certain pattern. To evaluate a behavior style and an integrity of the stacked structure subject to a seismic load, a modeling technique to represent the contact surface characteristics between a block and a block support structure and between blocks is necessary. The way to evaluate a load path is also needed. However, it is difficult to deal with a realistic seismic load and to figure out the characteristic of block behavior since it has very complicated time history. In this study, the evaluation of single block subject to a harmonic excitation is conducted for a preliminary evaluation

Transfer functions of US transducers for harmonic imaging and bubble respons

NARCIS (Netherlands)

van Neer, Paul L.M.J.; Matte, Guillaume; Sijl, J.; Borsboom, Jerome M.G.; de Jong, N.

2007-01-01

Current medical diagnostic echo systems are mostly using harmonic imaging. This means that a fundamental frequency (e.g., 2 MHz) is transmitted and the reflected and scattered higher harmonics (e.g., 4 and 6 MHz), produced by nonlinear propagation, are recorded. The signal level of these harmonics

Multivariable polynomial fitting of controlled single-phase nonlinear load of input current total harmonic distortion

Science.gov (United States)

Sikora, Roman; Markiewicz, Przemysław; Pabjańczyk, Wiesława

2018-04-01

The power systems usually include a number of nonlinear receivers. Nonlinear receivers are the source of disturbances generated to the power system in the form of higher harmonics. The level of these disturbances describes the total harmonic distortion coefficient THD. Its value depends on many factors. One of them are the deformation and change in RMS value of supply voltage. A modern LED luminaire is a nonlinear receiver as well. The paper presents the results of the analysis of the influence of change in RMS value of supply voltage and the level of dimming of the tested luminaire on the value of the current THD. The analysis was made using a mathematical model based on multivariable polynomial fitting.

Potential harmonic expansion for atomic wave functions

International Nuclear Information System (INIS)

Fabre de la Ripelle, M.; Larsen, S.Y.

1991-01-01

One way to reduce the large degeneracy of the Hyperspherical Harmonic basis for solving few- and many-body bound state problems is to introduce an optimal basis truncation called the Potential Harmonic (PH) basis. Various PH truncation schemes are introduced, and their accuracies are evaluated in predicting the energies of the Helium and H - ground states , and the excited 2 1 S level of the Helium atom. It was found that the part of the PH basis that accounts for one-body correlations gives a better ground state energy for He than the Hartree-Fock approximation. When an orthogonal complement is introduced to the basis to account for e-e correlations, the error in the binding energy is found to be .00025 au and .00015 au for ground and excited helium, resp., and .00035 au for H - . Furthermore, the PH truncation is about 99.9% accurate in accounting for contributions coming from large values of the global angular momentum. This PH scheme is also much more accurate than previous versions based on the Faddeev equations. The present results indicate that the PH truncation can render the Hyperspherical Harmonic method useful for systems with N>3. (R.P.) 14 refs., 4 tabs

Comparison of spatial harmonics in infinite and finite Bragg stacks for metamaterial homogenization

DEFF Research Database (Denmark)

Clausen, Niels Christian Jerichau; Arslanagic, Samel; Breinbjerg, Olav

2014-01-01

Metamaterial homogenization may be based on the dominance of a single Floquet-Bloch spatial harmonic in an infinite periodic structure - with the dominance quantified in terms of the relative magnitude of the associated spatial harmonic Poynting vector. For the corresponding finite structure...... the field is not quasi-periodic and cannot be expanded in Floquet-Bloch spatial harmonics; however, a set of pseudo spatial harmonics can be defined and the dominance of a single such harmonic likewise be used to determine whether the structure can be homogenized. For three different lossless Bragg stack...

Contribution to harmonic balance calculations of self-sustained periodic oscillations with focus on single-reed instruments.

Science.gov (United States)

Farner, Snorre; Vergez, Christophe; Kergomard, Jean; Lizée, Aude

2006-03-01

The harmonic balance method (HBM) was originally developed for finding periodic solutions of electronical and mechanical systems under a periodic force, but has been adapted to self-sustained musical instruments. Unlike time-domain methods, this frequency-domain method does not capture transients and so is not adapted for sound synthesis. However, its independence of time makes it very useful for studying any periodic solution, whether stable or unstable, without care of particular initial conditions in time. A computer program for solving general problems involving nonlinearly coupled exciter and resonator, HARMBAL, has been developed based on the HBM. The method as well as convergence improvements and continuation facilities are thoroughly presented and discussed in the present paper. Applications of the method are demonstrated, especially on problems with severe difficulties of convergence: the Helmholtz motion (square signals) of single-reed instruments when no losses are taken into account, the reed being modeled as a simple spring.

Bio-inspired piezoelectric linear motor driven by a single-phase harmonic wave with an asymmetric stator.

Science.gov (United States)

Pan, Qiaosheng; Miao, Enming; Wu, Bingxuan; Chen, Weikang; Lei, Xiujun; He, Liangguo

2017-07-01

A novel, bio-inspired, single-phase driven piezoelectric linear motor (PLM) using an asymmetric stator was designed, fabricated, and tested to avoid mode degeneracy and to simplify the drive mechanism of a piezoelectric motor. A piezoelectric transducer composed of two piezoelectric stacks and a displacement amplifier was used as the driving element of the PLM. Two simple and specially designed claws performed elliptical motion. A numerical simulation was performed to design the stator and determine the feasibility of the design mechanism of the PLM. Moreover, an experimental setup was built to validate the working principles, as well as to evaluate the performance, of the PLM. The prototype motor outputs a no-load speed of 233.7 mm/s at a voltage of 180 V p-p and a maximum thrust force of 2.3 N under a preload of 10 N. This study verified the feasibility of the proposed design and provided a method to simplify the driving harmonic signal and structure of PLMs.

Input Harmonic Analysis on the Slim DC-Link Drive Using Harmonic State Space Model

DEFF Research Database (Denmark)

Yang, Feng; Kwon, Jun Bum; Wang, Xiongfei

2017-01-01

The harmonic performance of the slim dc-link adjustable speed drives has shown good performance in some studies but poor in some others. The contradiction indicates that a feasible theoretical analysis is still lacking to characterize the harmonic distortion for the slim dc-link drive. Considerin...... results of the slim dc-link drive, loaded up to 2.0 kW, are presented to validate the theoretical analysis....... variation according to the switching instant, the harmonics at the steady-state condition, as well as the coupling between the multiple harmonic impedances. By using this model, the impaction on the harmonics performance by the film capacitor and the grid inductance is derived. Simulation and experimental...

How classical gluon fields generate odd azimuthal harmonics for the two-gluon correlation function in high-energy collisions

Science.gov (United States)

Kovchegov, Yuri V.; Skokov, Vladimir V.

2018-05-01

We show that, in the saturation/color glass condensate framework, odd azimuthal harmonics of the two-gluon correlation function with a long-range separation in rapidity are generated by the higher-order saturation corrections in the interactions with the projectile and the target. At the very least, the odd harmonics require three scatterings in the projectile and three scatterings in the target. We derive the leading-order expression for the two-gluon production cross section which generates odd harmonics: the expression includes all-order interactions with the target and three interactions with the projectile. We evaluate the obtained expression both analytically and numerically, confirming that the odd-harmonics contribution to the two-gluon production in the saturation framework is nonzero.

Harmonic Interaction Analysis in Grid Connected Converter using Harmonic State Space (HSS) Modeling

DEFF Research Database (Denmark)

Kwon, Jun Bum; Wang, Xiongfei; Bak, Claus Leth

2015-01-01

-model, are introduced to analyze these problems. However, it is found that Linear Time Invariant (LTI) base model analysis makes it difficult to analyze these phenomenon because of time varying system operation trajectories, varying output impedance seen by grid connected systems and neglected switching component......An increasing number of power electronics based Distributed Generation (DG) systems and loads generate coupled harmonic as well as non-characteristic harmonic with each other. Several methods like impedance based analysis, which is derived from conventional small signal- and average...... during the modeling process. This paper investigates grid connected converter by means of Harmonic State Space (HSS) small signal model, which is modeled from Linear Time varying Periodically (LTP) system. Further, a grid connected converter harmonic matrix is investigated to analyze the harmonic...

Exact solution of the time-dependent harmonic plus an inverse harmonic potential with a time-dependent electromagnetic field

International Nuclear Information System (INIS)

Yuece, Cem

2003-01-01

In this paper, the problem of the charged harmonic plus an inverse harmonic oscillator with time-dependent mass and frequency in a time-dependent electromagnetic field is investigated. It is reduced to the problem of the inverse harmonic oscillator with time-independent parameters and the exact wave function is obtained

Multivariable polynomial fitting of controlled single-phase nonlinear load of input current total harmonic distortion

Directory of Open Access Journals (Sweden)

Sikora Roman

2018-04-01

Full Text Available The power systems usually include a number of nonlinear receivers. Nonlinear receivers are the source of disturbances generated to the power system in the form of higher harmonics. The level of these disturbances describes the total harmonic distortion coefficient THD. Its value depends on many factors. One of them are the deformation and change in RMS value of supply voltage. A modern LED luminaire is a nonlinear receiver as well. The paper presents the results of the analysis of the influence of change in RMS value of supply voltage and the level of dimming of the tested luminaire on the value of the current THD. The analysis was made using a mathematical model based on multivariable polynomial fitting.

Group theoretic derivation of angular functions for the non-relativistic A-body problem in the K-harmonics approach

International Nuclear Information System (INIS)

Alcaras, J.A.C.; Ferreira, J.L.

1975-01-01

A derivation of an angular basis for the A-body problem, suitable for the K-harmonics method, is presented. Those angular functions are obtained from homogeneous and harmonic polynomials, which are completely specified by labels associated to eigenvalues of the Casimir invariants of subgroups of the 3(A-1)-dimensional orthogonal group, among them, the total angular momentum and its z-projection [pt

Harmonic and complex analysis in several variables

CERN Document Server

Krantz, Steven G

2017-01-01

Authored by a ranking authority in harmonic analysis of several complex variables, this book embodies a state-of-the-art entrée at the intersection of two important fields of research: complex analysis and harmonic analysis. Written with the graduate student in mind, it is assumed that the reader has familiarity with the basics of complex analysis of one and several complex variables as well as with real and functional analysis. The monograph is largely self-contained and develops the harmonic analysis of several complex variables from the first principles. The text includes copious examples, explanations, an exhaustive bibliography for further reading, and figures that illustrate the geometric nature of the subject. Each chapter ends with an exercise set. Additionally, each chapter begins with a prologue, introducing the reader to the subject matter that follows; capsules presented in each section give perspective and a spirited launch to the segment; preludes help put ideas into context. Mathematicians and...

Quantization of a 3D Nonstationary Harmonic plus an Inverse Harmonic Potential System

Directory of Open Access Journals (Sweden)

Salim Medjber

2016-01-01

Full Text Available The Schrödinger solutions for a three-dimensional central potential system whose Hamiltonian is composed of a time-dependent harmonic plus an inverse harmonic potential are investigated. Because of the time-dependence of parameters, we cannot solve the Schrödinger solutions relying only on the conventional method of separation of variables. To overcome this difficulty, special mathematical methods, which are the invariant operator method, the unitary transformation method, and the Nikiforov-Uvarov method, are used when we derive solutions of the Schrödinger equation for the system. In particular, the Nikiforov-Uvarov method with an appropriate coordinate transformation enabled us to reduce the eigenvalue equation of the invariant operator, which is a second-order differential equation, to a hypergeometric-type equation that is convenient to treat. Through this procedure, we derived exact Schrödinger solutions (wave functions of the system. It is confirmed that the wave functions are represented in terms of time-dependent radial functions, spherical harmonics, and general time-varying global phases. Such wave functions are useful for studying various quantum properties of the system. As an example, the uncertainty relations for position and momentum are derived by taking advantage of the wave functions.

Taylor-series method for four-nucleon wave functions

International Nuclear Information System (INIS)

Sandulescu, A.; Tarnoveanu, I.; Rizea, M.

1977-09-01

Taylor-series method for transforming the infinite or finite well two-nucleon wave functions from individual coordinates to relative and c.m. coordinates, by expanding the single particle shell model wave functions around c.m. of the system, is generalized to four-nucleon wave functions. Also the connections with the Talmi-Moshinsky method for two and four harmonic oscillator wave functions are deduced. For both methods Fortran IV programs for the expansion coefficients have been written and the equivalence of corresponding expressions numerically proved. (author)

Sample Data Synchronization and Harmonic Analysis Algorithm Based on Radial Basis Function Interpolation

Directory of Open Access Journals (Sweden)

Huaiqing Zhang

2014-01-01

Full Text Available The spectral leakage has a harmful effect on the accuracy of harmonic analysis for asynchronous sampling. This paper proposed a time quasi-synchronous sampling algorithm which is based on radial basis function (RBF interpolation. Firstly, a fundamental period is evaluated by a zero-crossing technique with fourth-order Newton’s interpolation, and then, the sampling sequence is reproduced by the RBF interpolation. Finally, the harmonic parameters can be calculated by FFT on the synchronization of sampling data. Simulation results showed that the proposed algorithm has high accuracy in measuring distorted and noisy signals. Compared to the local approximation schemes as linear, quadric, and fourth-order Newton interpolations, the RBF is a global approximation method which can acquire more accurate results while the time-consuming is about the same as Newton’s.

HARMONIZATION OF TAX POLICIES: REVIEWING MACEDONIA AND CROATIA

Directory of Open Access Journals (Sweden)

Sasho Kozuharov

2015-12-01

Full Text Available The tax harmonization is a complex issue in the process of European integration. The tax harmonization is a process of convergence of the tax system based on mutual set of rules and, in general, it means existence of identical or similar tax rates for the tax payers in European Union, i.e. Euro zone. In case there are identical tax rates, then we are talking about a, so called, total explicit tax harmonization, whereas, if there are similar tax rates, we are talking about partial explicit tax harmonization, which refers to determination of the highest and the lowest tax rates. Thus, countries can determine the tax rates of certain taxes. The total harmonization, besides tax rates harmonization, means structural harmonization or harmonization of the tax structure. The harmonization of direct taxes mainly relies on the following main objectives: avoiding tax evasion and elimination of double taxation. The harmonization of regulations and directives in the field of indirect taxes is necessary in terms of establishing a single market, or removal of barriers to the free movement of goods, people, services and capital.

Direct computation of harmonic moments for tomographic reconstruction

International Nuclear Information System (INIS)

Nara, Takaaki; Ito, Nobutaka; Takamatsu, Tomonori; Sakurai, Tetsuya

2007-01-01

A novel algorithm to compute harmonic moments of a density function from its projections is presented for tomographic reconstruction. For projection p(r, θ), we define harmonic moments of projection by ∫ π 0 ∫ ∞ -∞ p(r,θ)(re iθ ) n drd θ and show that it coincides with the harmonic moments of the density function except a constant. Furthermore, we show that the harmonic moment of projection of order n can be exactly computed by using n+ 1 projection directions, which leads to an efficient algorithm to reconstruct the vertices of a polygon from projections.

Red Shift and Broadening of Backward Harmonic Radiation from Electron Oscillations Driven by Femtosecond Laser Pulse

International Nuclear Information System (INIS)

Tian Youwei; Yu Wei; Lu Peixiang; Senecha, Vinod K; Han, Xu; Deng Degang; Li Ruxin; Xu Zhizhan

2006-01-01

The characteristics of backward harmonic radiation due to electron oscillations driven by a linearly polarized fs laser pulse are analysed considering a single electron model. The spectral distributions of the electron's backward harmonic radiation are investigated in detail for different parameters of the driver laser pulse. Higher order harmonic radiations are possible for a sufficiently intense driving laser pulse. We have shown that for a realistic pulsed photon beam, the spectrum of the radiation is red shifted as well as broadened because of changes in the longitudinal velocity of the electrons during the laser pulse. These effects are more pronounced at higher laser intensities giving rise to higher order harmonics that eventually leads to a continuous spectrum. Numerical simulations have further shown that by increasing the laser pulse width the broadening of the high harmonic radiations can be controlled

Particle swarm approach based on quantum mechanics and harmonic oscillator potential well for economic load dispatch with valve-point effects

International Nuclear Information System (INIS)

Santos Coelho, Leandro dos; Mariani, Viviana Cocco

2008-01-01

Particle swarm optimization (PSO) algorithm is population-based heuristic global search algorithm inspired by social behavior patterns of organisms that live and interact within large groups. The PSO is based on researches on swarms such as fish schooling and bird flocking. Inspired by the classical PSO method and quantum mechanics theories, this work presents a quantum-inspired version of the PSO (QPSO) using the harmonic oscillator potential well (HQPSO) to solve economic dispatch problems. A 13-units test system with incremental fuel cost function that takes into account the valve-point loading effects is used to illustrate the effectiveness of the proposed HQPSO method compared with the simulation results based on the classical PSO, the QPSO, and other optimization algorithms reported in the literature

Particle swarm approach based on quantum mechanics and harmonic oscillator potential well for economic load dispatch with valve-point effects

Energy Technology Data Exchange (ETDEWEB)

dos Santos Coelho, Leandro [Pontifical Catholic University of Parana, PUCPR Industrial and Systems Engineering Graduate Program, PPGEPS, Imaculada Conceicao, 1155, Zip code 80215-901, Curitiba, PR (Brazil); Mariani, Viviana Cocco [Pontifical Catholic University of Parana, PUCPR Mechanical Engineering Graduate Program, PPGEM, Imaculada Conceicao, 1155, Zip code 80215-901, Curitiba, PR (Brazil)

2008-11-15

Particle swarm optimization (PSO) algorithm is population-based heuristic global search algorithm inspired by social behavior patterns of organisms that live and interact within large groups. The PSO is based on researches on swarms such as fish schooling and bird flocking. Inspired by the classical PSO method and quantum mechanics theories, this work presents a quantum-inspired version of the PSO (QPSO) using the harmonic oscillator potential well (HQPSO) to solve economic dispatch problems. A 13-units test system with incremental fuel cost function that takes into account the valve-point loading effects is used to illustrate the effectiveness of the proposed HQPSO method compared with the simulation results based on the classical PSO, the QPSO, and other optimization algorithms reported in the literature. (author)

Particle swarm approach based on quantum mechanics and harmonic oscillator potential well for economic load dispatch with valve-point effects

Energy Technology Data Exchange (ETDEWEB)

Santos Coelho, Leandro dos [Pontifical Catholic University of Parana, PUCPR Industrial and Systems Engineering Graduate Program, PPGEPS, Imaculada Conceicao, 1155, Zip code 80215-901, Curitiba, PR (Brazil)], E-mail: leandro.coelho@pucpr.br; Mariani, Viviana Cocco [Pontifical Catholic University of Parana, PUCPR Mechanical Engineering Graduate Program, PPGEM, Imaculada Conceicao, 1155, Zip code 80215-901, Curitiba, PR (Brazil)], E-mail: viviana.mariani@pucpr.br

2008-11-15

Particle swarm optimization (PSO) algorithm is population-based heuristic global search algorithm inspired by social behavior patterns of organisms that live and interact within large groups. The PSO is based on researches on swarms such as fish schooling and bird flocking. Inspired by the classical PSO method and quantum mechanics theories, this work presents a quantum-inspired version of the PSO (QPSO) using the harmonic oscillator potential well (HQPSO) to solve economic dispatch problems. A 13-units test system with incremental fuel cost function that takes into account the valve-point loading effects is used to illustrate the effectiveness of the proposed HQPSO method compared with the simulation results based on the classical PSO, the QPSO, and other optimization algorithms reported in the literature.

Multimegawatt relativistic harmonic gyrotron traveling-wave tube amplifier experiments

International Nuclear Information System (INIS)

Menninger, W.L.; Danly, B.G.; Temkin, R.J.

1996-01-01

The first multimegawatt harmonic relativistic gyrotron traveling-wave tube (gyro-twt) amplifier experiment has been designed, built, and tested. Results from this experimental setup, including the first ever reported third-harmonic gyro-twt results, are presented. Operation frequency is 17.1 GHz. Detailed phase measurements are also presented. The electron beam source is SNOMAD-II, a solid-state nonlinear magnetic accelerator driver with nominal parameters of 400 kV and 350 A. The flat-top pulsewidth is 30 ns. The electron beam is focused using a Pierce geometry and then imparted with transverse momentum using a bifilar helical wiggler magnet. Experimental operation involving both a second-harmonic interaction with the TE 21 mode and a third-harmonic interaction with the TE 31 mode, both at 17 GHz, has been characterized. The third-harmonic interaction resulted in 4-MW output power and 50-dB single-pass gain, with an efficiency of up to ∼8%. The best measured phase stability of the TE 31 amplified pulse was ±10 degree over a 9-ns period. The phase stability was limited because the maximum RF power was attained when operating far from wiggler resonance. The second harmonic, TE 21 had a peak amplified power of 2 MW corresponding to 40-dB single-pass gain and 4% efficiency. The second-harmonic interaction showed stronger superradiant emission than the third-harmonic interaction. Characterizations of the second- and third-harmonic gyro-twt experiments presented here include measurement of far-field radiation patterns, gain and phase versus interaction length, phase stability, and output power versus input power

Harmonic modeling of induction motors

Energy Technology Data Exchange (ETDEWEB)

Pedra, J.; Sainz, L.; Corcoles, F. [Department of Electrical Engineering, ETSEIB-UPC, Av. Diagonal 647, 08028 Barcelona (Spain)

2006-07-15

The paper proposes an induction motor model for the study of harmonic load flow in balanced and unbalanced conditions. The parameters of this model are obtained from motor manufacturer data and the positive- and negative-sequence equivalent circuits of the single- and double-cage models. An approximate harmonic model based on motor manufacturer data only is also proposed. In addition, the paper includes manufacturer data and the calculated parameters of 36 induction motors of different rated powers. This database is used to analyze the proposed models. (author)

Tuvan throat singing and harmonics

Science.gov (United States)

Ruiz, Michael J.; Wilken, David

2018-05-01

Tuvan throat singing, also called overtone singing, provides for an exotic demonstration of the physics of harmonics as well as introducing an Asian musical aesthetic. A low fundamental is sung and the singer skillfully alters the resonances of the vocal system to enhance an overtone (harmonic above the fundamental). The result is that the listener hears two pitches simultaneously. Harmonics such as H8, H9, H10, and H12 form part of a pentatonic scale and are commonly selected for melody tones by Tuvan singers. A real-time spectrogram is provided in a video (Ruiz M J 2018 Video: Tuvan Throat Singing and Harmonics http://mjtruiz.com/ped/tuva/) so that Tuvan harmonics can be visualized as they are heard.

Harmonic scalpel versus electrocautery dissection in modified radical mastectomy: a randomized controlled trial.

Science.gov (United States)

Khan, Salma; Khan, Shaista; Chawla, Tabish; Murtaza, Ghulam

2014-03-01

To test the hypothesis that the use of a harmonic scalpel increases operative time but results in less estimated blood loss, postoperative pain, drainage volume, and duration of surgery, as well as fewer complications, such as flap necrosis, seroma, and surgical site infection (SSI), than electrocautery. This parallel-group, single-institution blinded randomized controlled trial was conducted at the department of surgery of our institute between April 2010 and July 2011. Women undergoing modified radical mastectomy were randomly allocated to either harmonic dissection (n = 76) or electrocautery (n = 76). Both the groups were comparable for baseline variables with age of 50.5 ± 12.2 and 48.5 ± 14.5 years in the harmonic and electrocautery groups, respectively. Harmonic dissection yielded better outcomes compared to electrocautery with lower estimated blood loss (100 ± 62 vs. 182 ± 92, p electrocautery (r2 = 0.28, β = 11.8, p < 0.001). The harmonic scalpel significantly reduces postoperative discomfort and morbidity to the patient without increasing operating time. We thus recommend preferential use of harmonic dissection in modified radical mastectomy. (ClinicalTrials.gov NCT01587248).

Quantum Mechanical Single Molecule Partition Function from PathIntegral Monte Carlo Simulations

Energy Technology Data Exchange (ETDEWEB)

Chempath, Shaji; Bell, Alexis T.; Predescu, Cristian

2006-10-01

An algorithm for calculating the partition function of a molecule with the path integral Monte Carlo method is presented. Staged thermodynamic perturbation with respect to a reference harmonic potential is utilized to evaluate the ratio of partition functions. Parallel tempering and a new Monte Carlo estimator for the ratio of partition functions are implemented here to achieve well converged simulations that give an accuracy of 0.04 kcal/mol in the reported free energies. The method is applied to various test systems, including a catalytic system composed of 18 atoms. Absolute free energies calculated by this method lead to corrections as large as 2.6 kcal/mol at 300 K for some of the examples presented.

Influence of Interface Gap on the Stress Behaviour of Smart Single Lap Joints Under Time Harmonic Load

Directory of Open Access Journals (Sweden)

Ivanova Jordanka

2017-06-01

Full Text Available Adhesive joints are frequently used in different composite structures due to their improved mechanical performance and better understanding of the failure mechanics. The application of such structures can be seen in aerospace and high technology components. The authors developed and applied modified shear lag analysis to investigate the hygrothermalpiezoelectric response of a smart single lap joint at environmental conditions (with/without an interface gap along the overlap zone and under dynamic time harmonic mechanical and electric loads. The main key is the study of the appearance of possible delamination along the interface. As illustrative examples, the analytical closed form solution of the structure shear and the axial stresses response, as well as the interface debond length, including influence of mechanical, piezoelectric, thermal characteristics and frequencies is performed and discussed. All results are presented in figures. The comparison of the shear stress and electric fields for both cases of overlap zone (continuous or with a gap is also shown in figures and discussed.

Efficiency of different methods of extra-cavity second harmonic generation of continuous wave single-frequency radiation.

Science.gov (United States)

Khripunov, Sergey; Kobtsev, Sergey; Radnatarov, Daba

2016-01-20

This work presents for the first time to the best of our knowledge a comparative efficiency analysis among various techniques of extra-cavity second harmonic generation (SHG) of continuous-wave single-frequency radiation in nonperiodically poled nonlinear crystals within a broad range of power levels. Efficiency of nonlinear radiation transformation at powers from 1 W to 10 kW was studied in three different configurations: with an external power-enhancement cavity and without the cavity in the case of single and double radiation pass through a nonlinear crystal. It is demonstrated that at power levels exceeding 1 kW, the efficiencies of methods with and without external power-enhancement cavities become comparable, whereas at even higher powers, SHG by a single or double pass through a nonlinear crystal becomes preferable because of the relatively high efficiency of nonlinear transformation and fairly simple implementation.

Harmonic Maass forms and mock modular forms

CERN Document Server

Bringmann, Kathrin; Ono, Ken

2017-01-01

Modular forms and Jacobi forms play a central role in many areas of mathematics. Over the last 10-15 years, this theory has been extended to certain non-holomorphic functions, the so-called "harmonic Maass forms". The first glimpses of this theory appeared in Ramanujan's enigmatic last letter to G. H. Hardy written from his deathbed. Ramanujan discovered functions he called "mock theta functions" which over eighty years later were recognized as pieces of harmonic Maass forms. This book contains the essential features of the theory of harmonic Maass forms and mock modular forms, together with a wide variety of applications to algebraic number theory, combinatorics, elliptic curves, mathematical physics, quantum modular forms, and representation theory.

Harmonic generation with a dual frequency pulse.

Science.gov (United States)

Keravnou, Christina P; Averkiou, Michalakis A

2014-05-01

Nonlinear imaging was implemented in commercial ultrasound systems over the last 15 years offering major advantages in many clinical applications. In this work, pulsing schemes coupled with a dual frequency pulse are presented. The pulsing schemes considered were pulse inversion, power modulation, and power modulated pulse inversion. The pulse contains a fundamental frequency f and a specified amount of its second harmonic 2f. The advantages and limitations of this method were evaluated with both acoustic measurements of harmonic generation and theoretical simulations based on the KZK equation. The use of two frequencies in a pulse results in the generation of the sum and difference frequency components in addition to the other harmonic components. While with single frequency pulses, only power modulation and power modulated pulse inversion contained odd harmonic components, with the dual frequency pulse, pulse inversion now also contains odd harmonic components.

Superstrings and harmonic superspace

International Nuclear Information System (INIS)

Kallosh, R.E.; AN SSSR, Moscow. Fizicheskij Inst.)

1987-01-01

The paper on superstrings and harmonic superspace is a contribution to the book dedicated to E.S. Fradkin on his sixtieth birthday. The purpose of the paper is to propose a description of N = 2,3 superspace which could be used for the investigation of the effective d = 10 harmonic superspace corresponding to the heterotic superstring. A description is given of the structure of semi-simple Lie algebras in the Cartan-Weyl basis, as well as the general properties of the even, compact part of harmonic superspace. The main properties of the four-dimensional N = 2 SYM theory are discussed, along with the N = 3, d = 4 super Yang-Mills theory. Finally the relation between the harmonic superspace and the heterotic E 8 x E 8 superstring is examined. (U.K.)

Antimicrobial activity and second harmonic studies on organic non-centrosymmetric pure and doped ninhydrin single crystals

Science.gov (United States)

Prasanyaa, T.; Jayaramakrishnan, V.; Haris, M.

2013-03-01

In this paper, we report the successful growth of pure, Cu2+ ions and Cd2+ ions doped on ninhydrin single crystals by slow solvent evaporation technique. The presence of Cu2+ and Cd2+ ions in the specimen of ninhydrin single crystal has been determined by atomic absorption spectroscopy. The powder X-ray diffraction analysis was done to calculate the lattice parameters of the pure and doped crystals. The percentage of transmittance of the crystal was recorded using the UV-Vis Spectrophotometer. Thermal behaviors of the grown crystals have been examined by the thermal gravimetric/differential thermal analysis. The hardness of the grown crystals was assessed and the results show the minor variation in the hardness value for the pure and doped ninhydrin samples. The value of the work hardening coefficient n was found to be 2.0, 1.0 and 1.06 for pure, copper and cadmium doped ninhydrin crystals respectively. The second harmonic generation efficiency of Cd2+ and Cu2+ doped ninhydrin is 8.3 and 6.3 times greater than well known nonlinear crystal of potassium dihydrogen phosphate respectively. The antibacterial and antifungal activities of the title compound were performed by disk diffusion method against the standard bacteria Escherichia coli, Xanthomonas oryzae and against the fungus Aspergillis niger and Aspergillus flavus.

Statistical properties of spectra in harmonically trapped spin-orbit coupled systems

DEFF Research Database (Denmark)

V. Marchukov, O.; G. Volosniev, A.; V. Fedorov, D.

2014-01-01

We compute single-particle energy spectra for a one-body Hamiltonian consisting of a two-dimensional deformed harmonic oscillator potential, the Rashba spin-orbit coupling and the Zeeman term. To investigate the statistical properties of the obtained spectra as functions of deformation, spin......-orbit and Zeeman strengths we examine the distributions of the nearest neighbor spacings. We find that the shapes of these distributions depend strongly on the three potential parameters. We show that the obtained shapes in some cases can be well approximated with the standard Poisson, Brody and Wigner...... distributions. The Brody and Wigner distributions characterize irregular motion and help identify quantum chaotic systems. We present a special choices of deformation and spin-orbit strengths without the Zeeman term which provide a fair reproduction of the fourth-power repelling Wigner distribution. By adding...

State operator, constants of the motion, and Wigner functions: The two-dimensional isotropic harmonic oscillator

DEFF Research Database (Denmark)

Dahl, Jens Peder; Schleich, W. P.

2009-01-01

For a closed quantum system the state operator must be a function of the Hamiltonian. When the state is degenerate, additional constants of the motion enter the play. But although it is the Weyl transform of the state operator, the Wigner function is not necessarily a function of the Weyl...... transforms of the constants of the motion. We derive conditions for which this is actually the case. The Wigner functions of the energy eigenstates of a two-dimensional isotropic harmonic oscillator serve as an important illustration....

Model tests and numerical analyses on horizontal impedance functions of inclined single piles embedded in cohesionless soil

Science.gov (United States)

Goit, Chandra Shekhar; Saitoh, Masato

2013-03-01

Horizontal impedance functions of inclined single piles are measured experimentally for model soil-pile systems with both the effects of local soil nonlinearity and resonant characteristics. Two practical pile inclinations of 5° and 10° in addition to a vertical pile embedded in cohesionless soil and subjected to lateral harmonic pile head loadings for a wide range of frequencies are considered. Results obtained with low-to-high amplitude of lateral loadings on model soil-pile systems encased in a laminar shear box show that the local nonlinearities have a profound impact on the horizontal impedance functions of piles. Horizontal impedance functions of inclined piles are found to be smaller than the vertical pile and the values decrease as the angle of pile inclination increases. Distinct values of horizontal impedance functions are obtained for the `positive' and `negative' cycles of harmonic loadings, leading to asymmetric force-displacement relationships for the inclined piles. Validation of these experimental results is carried out through three-dimensional nonlinear finite element analyses, and the results from the numerical models are in good agreement with the experimental data. Sensitivity analyses conducted on the numerical models suggest that the consideration of local nonlinearity at the vicinity of the soil-pile interface influence the response of the soil-pile systems.

Functional analysis, harmonic analysis, and image processing a collection of papers in honor of Bj"orn Jawerth

CERN Document Server

Cwikel, Michael

2017-01-01

This volume is dedicated to the memory of Björn Jawerth. It contains original research contributions and surveys in several of the areas of mathematics to which Björn made important contributions. Those areas include harmonic analysis, image processing, and functional analysis, which are of course interrelated in many significant and productive ways. Among the contributors are some of the world's leading experts in these areas. With its combination of research papers and surveys, this book may become an important reference and research tool. This book should be of interest to advanced graduate students and professional researchers in the areas of functional analysis, harmonic analysis, image processing, and approximation theory. It combines articles presenting new research with insightful surveys written by foremost experts.

Double Harmonic Transmission (D.H.T.

Directory of Open Access Journals (Sweden)

Sava Ianici

2006-10-01

Full Text Available The paper presents the construction and functioning of a new type of harmonic drive named double harmonic transmission (D.H.T.. In the second part of this paper is presented the dynamic analysis of the double harmonic transmission, which is based on the results of the experimental researches on the D.H.T. This study of the stress status and the forces distribution is necessary for to determine the durability on the portant elements of the D.H.T.

Second harmonic inversion for ultrasound contrast harmonic imaging

Energy Technology Data Exchange (ETDEWEB)

Pasovic, Mirza; Danilouchkine, Mike; Faez, Telli; Van Neer, Paul L M J; Van der Steen, Antonius F W; De Jong, Nico [THORAXCENTER, Department of Biomedical Engineering Ee2302, Erasmus MC, Rotterdam (Netherlands); Cachard, Christian; Basset, Olivier, E-mail: mirza.pasovic@creatis.insa-lyon.fr [CREATIS-LRMN, Universite de Lyon, INSA-Lyon, Universite Lyon 1, Inserm U630, CNRS UMR 5220 (France)

2011-06-07

Ultrasound contrast agents (UCAs) are small micro-bubbles that behave nonlinearly when exposed to an ultrasound wave. This nonlinear behavior can be observed through the generated higher harmonics in a back-scattered echo. In past years several techniques have been proposed to detect or image harmonics produced by UCAs. In these proposed works, the harmonics generated in the medium during the propagation of the ultrasound wave played an important role, since these harmonics compete with the harmonics generated by the micro-bubbles. We present a method for the reduction of the second harmonic generated during nonlinear-propagation-dubbed second harmonic inversion (SHI). A general expression for the suppression signals is also derived. The SHI technique uses two pulses, p' and p'', of the same frequency f{sub 0} and the same amplitude P{sub 0} to cancel out the second harmonic generated by nonlinearities of the medium. Simulations show that the second harmonic is reduced by 40 dB on a large axial range. Experimental SHI B-mode images, from a tissue-mimicking phantom and UCAs, show an improvement in the agent-to-tissue ratio (ATR) of 20 dB compared to standard second harmonic imaging and 13 dB of improvement in harmonic power Doppler.

Second harmonic inversion for ultrasound contrast harmonic imaging

International Nuclear Information System (INIS)

Pasovic, Mirza; Danilouchkine, Mike; Faez, Telli; Van Neer, Paul L M J; Van der Steen, Antonius F W; De Jong, Nico; Cachard, Christian; Basset, Olivier

2011-01-01

Ultrasound contrast agents (UCAs) are small micro-bubbles that behave nonlinearly when exposed to an ultrasound wave. This nonlinear behavior can be observed through the generated higher harmonics in a back-scattered echo. In past years several techniques have been proposed to detect or image harmonics produced by UCAs. In these proposed works, the harmonics generated in the medium during the propagation of the ultrasound wave played an important role, since these harmonics compete with the harmonics generated by the micro-bubbles. We present a method for the reduction of the second harmonic generated during nonlinear-propagation-dubbed second harmonic inversion (SHI). A general expression for the suppression signals is also derived. The SHI technique uses two pulses, p' and p'', of the same frequency f 0 and the same amplitude P 0 to cancel out the second harmonic generated by nonlinearities of the medium. Simulations show that the second harmonic is reduced by 40 dB on a large axial range. Experimental SHI B-mode images, from a tissue-mimicking phantom and UCAs, show an improvement in the agent-to-tissue ratio (ATR) of 20 dB compared to standard second harmonic imaging and 13 dB of improvement in harmonic power Doppler.

Harmonic analysis from Fourier to wavelets

CERN Document Server

Pereyra, Maria Cristina

2012-01-01

In the last 200 years, harmonic analysis has been one of the most influential bodies of mathematical ideas, having been exceptionally significant both in its theoretical implications and in its enormous range of applicability throughout mathematics, science, and engineering. In this book, the authors convey the remarkable beauty and applicability of the ideas that have grown from Fourier theory. They present for an advanced undergraduate and beginning graduate student audience the basics of harmonic analysis, from Fourier's study of the heat equation, and the decomposition of functions into sums of cosines and sines (frequency analysis), to dyadic harmonic analysis, and the decomposition of functions into a Haar basis (time localization). While concentrating on the Fourier and Haar cases, the book touches on aspects of the world that lies between these two different ways of decomposing functions: time-frequency analysis (wavelets). Both finite and continuous perspectives are presented, allowing for the introd...

Laser waveform control of extreme ultraviolet high harmonics from solids.

Science.gov (United States)

You, Yong Sing; Wu, Mengxi; Yin, Yanchun; Chew, Andrew; Ren, Xiaoming; Gholam-Mirzaei, Shima; Browne, Dana A; Chini, Michael; Chang, Zenghu; Schafer, Kenneth J; Gaarde, Mette B; Ghimire, Shambhu

2017-05-01

Solid-state high-harmonic sources offer the possibility of compact, high-repetition-rate attosecond light emitters. However, the time structure of high harmonics must be characterized at the sub-cycle level. We use strong two-cycle laser pulses to directly control the time-dependent nonlinear current in single-crystal MgO, leading to the generation of extreme ultraviolet harmonics. We find that harmonics are delayed with respect to each other, yielding an atto-chirp, the value of which depends on the laser field strength. Our results provide the foundation for attosecond pulse metrology based on solid-state harmonics and a new approach to studying sub-cycle dynamics in solids.

Single particle level density in a finite depth potential well

International Nuclear Information System (INIS)

Shlomo, S.; Kolomietz, V.M.; Dejbakhsh, H.

1997-01-01

We consider the single particle level density g(ε) of a realistic finite depth potential well, concentrating on the continuum (ε>0) region. We carry out quantum-mechanical calculations of the partial level density g l (ε), associated with a well-defined orbital angular momentum l≤40, using the phase-shift derivative method and the Greens-function method and compare the results with those obtained using the Thomas-Fermi approximation. We also numerically calculate g(ε) as a l sum of g l (ε) up to a certain value of scr(l) max ≤40 and determine the corresponding smooth level densities using the Strutinsky smoothing procedure. We demonstrate, in accordance with Levinson close-quote s theorem, that the partial contribution g l (ε) to the single particle level density from continuum states has positive and negative values. However, g(ε) is nonnegative. We also point out that this is not the case for an energy-dependent potential well. copyright 1997 The American Physical Society

Mellin moments of the next-to-next-to leading order coefficient functions for the Drell-Yan process and hadronic Higgs-boson production

International Nuclear Information System (INIS)

Bluemlein, J.; Ravindran, V.

2005-01-01

We calculate the Mellin moments of the next-to-next-to leading order coefficient functions for the Drell-Yan and Higgs production cross sections. The results can be expressed in terms of multiple finite harmonic sums of maximal weight w=4. Using algebraic and structural relations between harmonic sums one finds that besides the single harmonic sums only five basic sums and their derivatives w.r.t. the summation index contribute. This representation reduces the large complexity being present in x-space calculations and is well suited for fast numerical implementations. (orig.)

Absorption of fast waves at moderate to high ion cyclotron harmonics on DIII-D

International Nuclear Information System (INIS)

Pinsker, R.I.; Porkolab, M.; Heidbrink, W.W.; Luo, Y.; Petty, C.C.; Prater, R.; Choi, M.; Schaffner, D.A.; Baity, F.W.; Fredd, E.; Hosea, J.C.; Harvey, R.W.; Smirnov, A.P.; Murakami, M.; Zeeland, M.A. Van

2006-01-01

The absorption of fast Alfven waves (FW) by ion cyclotron harmonic damping in the range of harmonics from 4th to 8th is studied theoretically and with experiments in the DIII-D tokamak. A formula for linear ion cyclotron absorption on ions with an arbitrary distribution function which is symmetric about the magnetic field is used to estimate the single-pass damping for various cases of experimental interest. It is found that damping on fast ions from neutral beam injection can be significant even at the 8th harmonic if the fast ion beta, the beam injection energy and the background plasma density are high enough and the beam injection geometry is appropriate. The predictions are tested in several L-mode experiments in DIII-D with FW power at 60 MHz and at 116 MHz. It is found that 4th and 5th harmonic absorption of the 60 MHz power on the beam ions can be quite strong, but 8th harmonic absorption of the 116 MHz power appears to be weaker than expected. The linear modelling predicts a strong dependence of the 8th harmonic absorption on the initial pitch-angle of the injected beam, which is not observed in the experiment. Possible explanations of the discrepancy are discussed

Solution of Schroedinger equation for particle moving in two-well potential

International Nuclear Information System (INIS)

Ivanova, O.I.; Sabirov, R.Kh.

2000-01-01

The solution of the Schroedinger equation for the particle, moving in the two-well potential is given on the basis of a single variational method. This potential constitutes the sum of the harmonic potential and the Gaussian addition. The analytical expression for the wave function of the particle basic state is obtained. The dependence of the obtained solutions on the potential barrier height and width is studied. It is shown that the better separation of the potential barrier provides for higher accuracy of the calculations. The values of the two-well potential, whereby good agreement between the calculations and exact numerical solution of the Schroedinger equation may be expected, are presented [ru

Harmonic Mitigation Methods in Large Offshore Wind Power Plants

DEFF Research Database (Denmark)

Kocewiak, Łukasz Hubert; Chaudhary, Sanjay; Hesselbæk, Bo

2013-01-01

Various sources of harmonic problems in large wind power plants (WPPs) and optimized harmonic mitigation methods are presented in this paper. The harmonic problems such as sources of harmonic emission and amplification as well as harmonic stability are identified. Also modern preventive...... and remedial harmonic mitigation methods in terms of passive and active filtering are described. It is shown that WPP components such as long HVAC cables and park transformers can introduce significant low-frequency resonances which can affect wind turbine control system operation and overall WPP stability...... as well as amplification of harmonic distortion. It is underlined that there is a potential in terms of active filtering in modern grid-side converters in e.g. wind turbines, STATCOMs or HVDC stations utilized in modern large WPPs. It is also emphasized that the grid-side converter controller should...

Internal-Model-Principle-Based Specific Harmonics Repetitive Controller for Grid-Connected PWM Inverters

Directory of Open Access Journals (Sweden)

Wenzhou Lu

2016-01-01

Full Text Available This paper analyzes the general properties of IMP-based controller and presents an internal-model-principle-based (IMP-based specific harmonics repetitive control (SHRC scheme. The proposed SHRC is effective for specific nk±m order harmonics, with n>m≥0 and k=0,1,2,…. Using the properties of exponential function, SHRC can also be rewritten into the format of multiple resonant controllers in parallel, where the control gain of SHRC is n/2 multiple of that of conventional RC (CRC. Therefore, including SHRC in a stable closed-loop feedback control system, asymptotic disturbance eliminating, or reference tracking for any periodic signal only including these specific harmonic components at n/2 times faster error convergence rate compared with CRC can be achieved. Application examples of SHRC controlled three-phase/single-phase grid-connected PWM inverters demonstrate the effectiveness and advantages of the proposed SHRC scheme.

Evaluation of Harmonics Impact on Digital Relays

Directory of Open Access Journals (Sweden)

Kinan Wannous

2018-04-01

Full Text Available This paper presents the concept of the impact of harmonic distortion on a digital protection relay. The aim is to verify and determine the reasons of a mal-trip or failure to trip the protection relays; the suggested solution of the harmonic distortion is explained by a mathematical model in the Matlab Simulink programming environment. The digital relays have been tested under harmonic distortions in order to verify the function of the relays algorithm under abnormal conditions. The comparison between the protection relay algorithm under abnormal conditions and a mathematical model in the Matlab Simulink programming environment based on injected harmonics of high values is provided. The test is separated into different levels; the first level is based on the harmonic effect of an individual harmonic and mixed harmonics. The test includes the effect of the harmonics in the location of the fault point into distance protection zones. This paper is a new proposal in the signal processing of power quality disturbances using Matlab Simulink and the power quality impact on the measurements of the power system quantities; the test simulates the function of protection in power systems in terms of calculating the current and voltage values of short circuits and their faults. The paper includes several tests: frequency variations and decomposition of voltage waveforms with Fourier transforms (model and commercial relay, the effect of the power factor on the location of fault points, the relation between the tripping time and the total harmonic distortion (THD levels in a commercial relay, and a comparison of the THD capture between the commercial relay and the model.

Tuvan Throat Singing and Harmonics

Science.gov (United States)

Ruiz, Michael J.; Wilken, David

2018-01-01

Tuvan throat singing, also called overtone singing, provides for an exotic demonstration of the physics of harmonics as well as introducing an Asian musical aesthetic. A low fundamental is sung and the singer skillfully alters the resonances of the vocal system to enhance an overtone (harmonic above the fundamental). The result is that the…

Efficient second harmonic generation by para-nitroaniline embedded in electro-spun polymeric nanofibres

Science.gov (United States)

Gonçalves, Hugo; Saavedra, Inês; Ferreira, Rute AS; Lopes, PE; de Matos Gomes, Etelvina; Belsley, Michael

2018-03-01

Intense well polarized second harmonic light was generated by poly(methyl methacrylate) nanofibres with embedded para-nitroaniline nanocrystals. Subwavelength diameter fibres were electro-spun using a 1:2 weight ratio of chromophore to polymer. Analysis of the generated second harmonic light indicates that the para-nitroaniline molecules, which nominally crystalize in the centrosymmetric space group, were organized into noncentrosymmetric structures leading to a second order susceptibility dominated by a single tensor element. Under the best deposition conditions, the nanofibrers display an effective nonlinear optical susceptibility approximately two orders of magnitude greater than that of potassium dihydrogen phosphate. Generalizing this approach to a broad range of organic molecules with strong individual molecular second order nonlinear responses, but which nominally form centrosymmetric organic crystals, could open a new pathway for the fabrication of efficient sub-micron sized second harmonic light generators.

Harmonics Monitoring Survey on LED Lamps

Directory of Open Access Journals (Sweden)

Abdelrahman Ahmed Akila

2017-03-01

Full Text Available Light Emitting Diode (LED lamps are being increasingly used in many applications. These LED lamps operate using a driver, which is a switching device. Hence, LED lamps will be a source of harmonics in the power system. These harmonics if not well treated, may cause severe performance and operational problems. In this paper, harmonics (amplitude and phase angles generated by both LED lamps and conventional fluorescent lamps will be studied practically. Then they will be analyzed and evaluated. Compared to each other harmonics generated by both LED and conventional florescent lamps, self mitigation may occur based on the phase angle of these harmonics. All data will be measured using power analyzer and will be done on a sample of actual lamps.

The Distortion Theorems for Harmonic Mappings with Analytic Parts Convex or Starlike Functions of Order β

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Mengkun Zhu

2015-01-01

Full Text Available Some sharp estimates of coefficients, distortion, and growth for harmonic mappings with analytic parts convex or starlike functions of order β are obtained. We also give area estimates and covering theorems. Our main results generalise those of Klimek and Michalski.

A prototype imaging second harmonic interferometer

International Nuclear Information System (INIS)

Jobes, F.C.; Bretz, N.L.

1997-01-01

We have built a prototype imaging second harmonic interferometer, which is intended to test critical elements of a design for a tangential array interferometer on C-Mod 6 . The prototype uses a pulsed, 35 mJ, 10 Hz multimode, Nd:YAG laser, LiB 3 O 5 doublers, a fan beam created by a cylindrical lens, four retroreflector elements, and a CCD camera as a detector. The prototype also uses a polarization scheme in which the interference information is eventually carried by two second harmonic beams with crossed polarization. These are vector summed and differenced, and separated, by a Wollaston prism, to give two spots on the CCD. There is a pair of these spots for each retroreflector used. The phase information is directly available as the ratio of the difference to sum the intensities of the two spots. We have tested a single channel configuration of this prototype, varying the phase by changing the pressure in an air cell, and we have obtained a 5:1 light to dark ratio, and a clear sinusoidal variation of the ratio as a function of pressure change. copyright 1997 American Institute of Physics

Functionalized bismuth ferrite harmonic nanoparticles for cancer cells labeling and imaging

Energy Technology Data Exchange (ETDEWEB)

Passemard, Solène; Staedler, Davide; Sonego, Giona [Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering (Switzerland); Magouroux, Thibaud [Université de Genève, GAP-Biophotonics (Switzerland); Schneiter, Guillaume Stéphane [Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering (Switzerland); Juillerat-Jeanneret, Lucienne [University Institute of Pathology, CHUV-UNIL (Switzerland); Bonacina, Luigi [Université de Genève, GAP-Biophotonics (Switzerland); Gerber-Lemaire, Sandrine, E-mail: Sandrine.Gerber@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering (Switzerland)

2015-10-15

Bismuth ferrite (BFO) harmonic nanoparticles (NPs) display high nonlinear optical efficiency and excellent biocompatibility profile which make them attractive for the development of diagnostic applications as contrast agents. In this study, we present a general method for the functionalization of this material with chemical ligands targeting cancer molecular biomarkers. In particular, a conjugation protocol based on click reaction between alkynyl-containing targeting ligands and poly(ethylene glycol)-coated BFO NPs (67.7 nm) displaying surface reactive azido groups was developed. Copper-free click reaction allowed fast and efficient conjugation of a covalent inhibitor of prolyl-specific endopeptidases to coated BFO NPs. The ability of these functionalized nanomaterials (134.2 nm) to act as imaging probes for cancer cells was demonstrated by the selective labeling of human lung cancer cells.

Factorization Procedure for Harmonically Bound Brownian Particle

International Nuclear Information System (INIS)

Omolo, JK.

2006-01-01

The method of factorization to solve the problem of the one-dimensional harmonically bound Brownian particle was applied. Assuming the the rapidily fluctuating random force is Gaussian and has an infinitely short correlation time, explicit expressions for the position-position,velocity-velocity, and the position-velocity correlation functions, which are also use to write down appropriate distribution functions were used. The correlation and distribution functions for the complex quantity (amplititude) which provides the expressions for the position and velocity of the particle are calculated. Finally, Fokker-Planck equations for the joint probability distribution functions for the amplititude and it's complex conjugate as well as for the position and velocity of the particle are obtained. (author)

High-order harmonic generation in a laser plasma: a review of recent achievements

International Nuclear Information System (INIS)

Ganeev, R A

2007-01-01

A review of studies of high-order harmonic generation in plasma plumes is presented. The generation of high-order harmonics (up to the 101st order, λ = 7.9 nm) of Ti:sapphire laser radiation during the propagation of short laser pulses through a low-excited, low-ionized plasma produced on the surfaces of different targets is analysed. The observation of considerable resonance-induced enhancement of a single harmonic (λ = 61.2 nm) at the plateau region with 10 -4 conversion efficiency in the case of an In plume can offer some expectations that analogous processes can be realized in other plasma samples in the shorter wavelength range. Recent achievements of single-harmonic enhancement at mid- and end-plateau regions are discussed. Various methods for the optimization of harmonic generation are analysed, such as the application of the second harmonic of driving radiation and the application of prepulses of different durations. The enhancement of harmonic generation efficiency during the propagation of femtosecond pulses through a nanoparticle-containing plasma is discussed. (topical review)

Femtosecond envelope of the high-harmonic emission from ablation plasmas

International Nuclear Information System (INIS)

Haessler, S; Gobert, O; Hergott, J-F; Lepetit, F; Perdrix, M; Carré, B; Salières, P; Bom, L B Elouga; Ozaki, T

2012-01-01

We characterize the temporal profile of the high-order harmonic emission from ablation plasma plumes using cross-correlations with the infrared (IR) laser beam provided by two-photon harmonic+IR ionization of rare gas atoms. We study both non-resonant plasmas (lead, gold and chrome) and resonant plasmas (indium and tin), i.e. plasmas presenting in the singly charged ions a strong radiative transition coinciding with a harmonic order. The cross-correlation traces are found to be very similar for all harmonic orders and all plasma targets. The recovered harmonic pulse durations are very similar to the driving laser, with a tendency towards being shorter, demonstrating that the emission is a directly laser-driven process even in the case of resonant harmonics. This provides a valuable input for theories describing resonant-harmonic emission and opens the perspective of a very high flux tabletop XUV source for applications. (paper)

Harmonically excited orbital variations

International Nuclear Information System (INIS)

Morgan, T.

1985-01-01

Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

Explaining the harmonic sequence paradox.

Science.gov (United States)

Schmidt, Ulrich; Zimper, Alexander

2012-05-01

According to the harmonic sequence paradox, an expected utility decision maker's willingness to pay for a gamble whose expected payoffs evolve according to the harmonic series is finite if and only if his marginal utility of additional income becomes zero for rather low payoff levels. Since the assumption of zero marginal utility is implausible for finite payoff levels, expected utility theory - as well as its standard generalizations such as cumulative prospect theory - are apparently unable to explain a finite willingness to pay. This paper presents first an experimental study of the harmonic sequence paradox. Additionally, it demonstrates that the theoretical argument of the harmonic sequence paradox only applies to time-patient decision makers, whereas the paradox is easily avoided if time-impatience is introduced. ©2011 The British Psychological Society.

E pluribus unum: Harmonization of physical functioning across intervention studies of middle-aged and older adults.

Directory of Open Access Journals (Sweden)

Nicole M Armstrong

Full Text Available Common scales for physical functioning are not directly comparable without harmonization techniques, complicating attempts to pool data across studies. Our aim was to provide a standardized metric for physical functioning in adults based on basic and instrumental activities of daily living scaled to NIH PROMIS norms. We provide an item bank to compare the difficulty of various physical functioning activities. We used item response theory methods to place 232 basic and instrumental activities of daily living questions, administered across eight intervention studies of middle-aged and older adults (N = 2,556, on a common metric. We compared the scale's precision to an average z-score of items and evaluated criterion validity based on objective measures of physical functioning and Fried's frailty criteria. Model-estimated item thresholds were widely distributed across the range of physical functioning. From test information plots, the lowest precision in each dataset was 0.80. Using power calculations, the sample size needed to detect 25% physical functional decline with 80% power based on the physical functioning factor was less than half of what would be needed using an average z-score. The physical functioning factor correlated in expected directions with objective measurements from the Timed Up and Go task, tandem balance, gait speed, chair stands, grip strength, and frailty status. Item-level harmonization enables direct comparison of physical functioning measures across existing and potentially future studies and across levels of function using a nationally representative metric. We identified key thresholds of physical functioning items in an item bank to facilitate clinical and epidemiologic decision-making.

Classical and multilinear harmonic analysis

CERN Document Server

Muscalu, Camil

2013-01-01

This two-volume text in harmonic analysis introduces a wealth of analytical results and techniques. It is largely self-contained and useful to graduates and researchers in pure and applied analysis. Numerous exercises and problems make the text suitable for self-study and the classroom alike. The first volume starts with classical one-dimensional topics: Fourier series; harmonic functions; Hilbert transform. Then the higher-dimensional Calderón-Zygmund and Littlewood-Paley theories are developed. Probabilistic methods and their applications are discussed, as are applications of harmonic analysis to partial differential equations. The volume concludes with an introduction to the Weyl calculus. The second volume goes beyond the classical to the highly contemporary and focuses on multilinear aspects of harmonic analysis: the bilinear Hilbert transform; Coifman-Meyer theory; Carleson's resolution of the Lusin conjecture; Calderón's commutators and the Cauchy integral on Lipschitz curves. The material in this vo...

Polarization-Resolved Study of High Harmonics from Bulk Semiconductors

Science.gov (United States)

Kaneshima, Keisuke; Shinohara, Yasushi; Takeuchi, Kengo; Ishii, Nobuhisa; Imasaka, Kotaro; Kaji, Tomohiro; Ashihara, Satoshi; Ishikawa, Kenichi L.; Itatani, Jiro

2018-06-01

The polarization property of high harmonics from gallium selenide is investigated using linearly polarized midinfrared laser pulses. With a high electric field, the perpendicular polarization component of the odd harmonics emerges, which is not present with a low electric field and cannot be explained by the perturbative nonlinear optics. A two-dimensional single-band model is developed to show that the anisotropic curvature of an energy band of solids, which is pronounced in an outer part of the Brillouin zone, induces the generation of the perpendicular odd harmonics. This model is validated by three-dimensional quantum mechanical simulations, which reproduce the orientation dependence of the odd-order harmonics. The quantum mechanical simulations also reveal that the odd- and even-order harmonics are produced predominantly by the intraband current and interband polarization, respectively. These experimental and theoretical demonstrations clearly show a strong link between the band structure of a solid and the polarization property of the odd-order harmonics.

Enhancement of harmonic generation using a two section undulator

International Nuclear Information System (INIS)

Prazeres, R.; Glotin, F.; Jaroszynski, D.A.; Ortega, J.M.; Rippon, C.

1999-01-01

Enhancement of the 2nd and 3rd harmonic of the wavelength of a Free-Electron Laser (FEL) has been measured when a single electron beam is crossing a two-section undulator. To produce the harmonic radiation enhancement, the undulator is arranged so that the resonance wavelength of the 2nd undulator (downstream) matches a harmonic of the 1st undulator (upstream). Both the fundamental and the harmonic optical fields evolve in the same optical cavity and are coupled out with different extraction efficiency, through a hole in one of the cavity mirrors. We present measurements that show that the optical power at the 2nd and 3rd harmonic can be enhanced, by about one order of magnitude, in two configurations: when the resonance wavelength of the 2nd undulator matches the harmonic of 1st one (harmonic configuration), or when the gap of the 2nd undulator is slightly larger than first one (step-tapered configuration). We examine the dependence of the harmonic power on the gap of the 2nd undulator. This fundamental/harmonic mode of operation of the FEL may have useful applications in the production of coherent X-ray and VUV radiation, a spectral range where high reflectivity optical cavity mirrors are difficult or impossible to manufacture

Site Selection Strategy of Single-Frequency Tuned R-APF for Background Harmonic Voltage Damping in Power Systems

DEFF Research Database (Denmark)

Sun, Xiaofeng; Zeng, Jian; Chen, Zhe

2013-01-01

, and analyze the harmonic voltage propagation caused by the background harmonic voltage in power systems. Then, a new strategy is proposed for the site selection of resistive active power filter to damp the background harmonic voltage in power systems. Experiments have been performed to verify the theoretical......Series resonance between capacitance and line inductance may magnify background harmonic voltage and worsen the harmonic voltage distortion in power systems. To solve this problem, in this paper, the transmission line theory is used to set up the distributed parameter model of power system feeders...

Modeling and Grid impedance Variation Analysis of Parallel Connected Grid Connected Inverter based on Impedance Based Harmonic Analysis

DEFF Research Database (Denmark)

Kwon, JunBum; Wang, Xiongfei; Bak, Claus Leth

2014-01-01

This paper addresses the harmonic compensation error problem existing with parallel connected inverter in the same grid interface conditions by means of impedance-based analysis and modeling. Unlike the single grid connected inverter, it is found that multiple parallel connected inverters and grid...... impedance can make influence to each other if they each have a harmonic compensation function. The analysis method proposed in this paper is based on the relationship between the overall output impedance and input impedance of parallel connected inverter, where controller gain design method, which can...

Harmonic generation effect in high-Tc films

International Nuclear Information System (INIS)

Khare, Neeraj; Shrivastava, S.K.; Padmanabhan, V.P.N.; Khare, Sangeeta; Gupta, A.K.

1997-01-01

Harmonic generation in thick BPSCCO and thin YBCO films are reported. The application of an ac field (H ac > H c1 ) of frequency f causes the generation of odd harmonics of frequency (2n+1)f. The application of dc field in addition to the ac field causes the appearance of even harmonics also in the BPSCCO film. However, the appearance of even harmonics is not observed in YBCO film with high J c ∼ 1.6x10 6 A/cm 2 and appearance of second harmonic with small magnitude is observed in YBCO film with low J c ∼ 2x10 3 A/cm 2 . The variation of amplitudes of these harmonics are studied as a function of magnitude of ac and dc field and the results are explained in the framework of critical state model. A high-T c film magnetometer based on the measurement of the amplitude of second harmonic has been developed whose field sensitivity is ∼ 1.5x10 -8 T. (author)

Design of six pulse bridge multiplication converter model for current harmonic elimination of three phase ac-dc converter

International Nuclear Information System (INIS)

Soomro, M.A.; Helepoto, I.A.

2014-01-01

The recent development of semiconductor technology and wide spread use of power electronic devices in power system have open the era of the power system harmonics due to increasing penetration of non-linear loads. Harmonics are widely admitted as most important issues of power quality which must be eliminated to maintain power system reliability. The tolerable THD (Total Harmonic Distortion) values must be bounded in well-defined limits recognized by IEEE-519 standard. In this work, in order to eliminate the current harmonics produced by non-linear loads, six pulse multiplication converter technique in conjunction with STSSHPE (Single Tuned Shunt Harmonic Passive Filter) is proposed. The proposed model has the capacity of harmonic cancellation of the dominant 3rd order harmonics. Besides that, the 5th and 7th order harmonics are also reduced to a diminishing level. The hardware model has been experimentally tested by PQA (Power Quality Analyzer) and simulation model is designed using MATLAB software. The acquired results have been measured by considering THD values in terms of current and voltage. Furthermore, they have been compared against IEEE-519 performance standards. The prosed model, successfully bounds the total harmonic distortion under defined limits by IEEE-519 standard. (author)

Designing single phase Current-Programmed-Controlled rectifiers by harmonic currents

DEFF Research Database (Denmark)

Andersen, Gert Karmisholt; Blaabjerg, Frede

2002-01-01

The grid current harmonics of a Current-Programmed-Controlled (CPC) pfc rectifier strongly depends on the choice of switching frequency and switching inductance. This paper describes a new simple and vert fast method to calculate the grid current of a CPC controlled pfc converter. The method...

Phase-coded multi-pulse technique for ultrasonic high-order harmonic imaging of biological tissues in vitro

International Nuclear Information System (INIS)

Ma Qingyu; Zhang Dong; Gong Xiufen; Ma Yong

2007-01-01

Second or higher order harmonic imaging shows significant improvement in image clarity but is degraded by low signal-noise ratio (SNR) compared with fundamental imaging. This paper presents a phase-coded multi-pulse technique to provide the enhancement of SNR for the desired high-order harmonic ultrasonic imaging. In this technique, with N phase-coded pulses excitation, the received Nth harmonic signal is enhanced by 20 log 10 N dB compared with that in the single-pulse mode, whereas the fundamental and other order harmonic components are efficiently suppressed to reduce image confusion. The principle of this technique is theoretically discussed based on the theory of the finite amplitude sound waves, and examined by measurements of the axial and lateral beam profiles as well as the phase shift of the harmonics. In the experimental imaging for two biological tissue specimens, a plane piston source at 2 MHz is used to transmit a sequence of multiple pulses with equidistant phase shift. The second to fifth harmonic images are obtained using this technique with N = 2 to 5, and compared with the images obtained at the fundamental frequency. Results demonstrate that this technique of relying on higher order harmonics seems to provide a better resolution and contrast of ultrasonic images

Identification of second harmonic optical effects from vaccine coated gold microparticles

International Nuclear Information System (INIS)

Jumah, N A; Ameer-Beg, S M; White, N S; Prasad, K V R; Bellhouse, B J

2004-01-01

This study investigates the optical effects observed from uncoated and protein vaccine coated gold microparticles while imaging with two-photon excitation in the Mie scattering regime. When observed with time correlated single photon counting fluorescence lifetime microscopy, the emission from the gold microparticles appeared as an intense instrument-limited temporal response. The intensity of the emission showed a second-order dependence on the laser power and frequency doubling of the emitted light was observed for fundamental light between 890 and 970 nm. The optical effect was attributed to two-photon induced second harmonic generation. The vaccine coated gold microparticles had a much weaker second harmonic signal than the uncoated gold microparticles. Chemical analysis of the surface of the gold microparticles revealed that the vaccine coating decreases the surface charge thereby diminishing the observed second harmonic signal. These optical properties can be exploited to identify both the location of the protein vaccine coating as well as the gold microparticles in vitro and potentially to investigate the vaccine delivery kinetics in vivo

Second-harmonic imaging of semiconductor quantum dots

DEFF Research Database (Denmark)

Østergaard, John Erland; Bozhevolnyi, Sergey I.; Pedersen, Kjeld

2000-01-01

Resonant second-harmonic generation is observed at room temperature in reflection from self-assembled InAlGaAs quantum dots grown on a GaAs (001) substrate. The detected second-harmonic signal peaks at a pump wavelength of similar to 885 nm corresponding to the quantum-dot photoluminescence maximum....... In addition, the second-harmonic spectrum exhibits another smaller but well-pronounced peak at 765 nm not found in the linear experiments. We attribute this peak to the generation of second-harmonic radiation in the AlGaAs spacer layer enhanced by the local symmetry at the quantum-dot interface. We further...

A broad-band (0.2-8 MHz) multiple-harmonic VITROVAC-filled acceleration structure

Energy Technology Data Exchange (ETDEWEB)

Ausset, P.; Charruau, G.; De Menezes, D.; Fougeron, C. [Laboratoire National Saturne, Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Etzkorn, F.J.; Papureanu, S.; Schnase, A.; Meuth, H. [Forschungszentrum Juelich GmbH (Germany)

1994-12-31

Higher or multiple-harmonic acceleration drives in synchrotrons are desirable, when passing the transition point, applying stochastic cooling on a bunched beam, or for many other longitudinal beam manipulations, as bunch stretching or compression. As proof-of-principle, virtually arbitrary, digitally synthesized voltage waveforms, employing contents up to fourth harmonic in the range 0.2-8 MHz, could be generated at the gap of one single (symmetric re-entrant) cavity, filled with discs of the novel ferritic amorphous metal VITROVAC of VAC, Hanau. A 10 kW amplifier produces voltages in the kV-range. As relevant examples, we achieved a flat-top waveform suitable for the transition (+27 deg, 10{sup -3} max. error), a fourth-order flattened bucket for bunched-beam cooling, and a harmonic bucket with linear restoring force. The compact cavity system should be well suited for any proton or heavy ion device operating in this frequency range, and therapy-oriented rings. (author). 9 refs., 6 figs.

A broad-band (0.2-8 MHz) multiple-harmonic VITROVAC-filled acceleration structure

International Nuclear Information System (INIS)

Ausset, P.; Charruau, G.; De Menezes, D.; Fougeron, C.; Etzkorn, F.J.; Papureanu, S.; Schnase, A.; Meuth, H.

1994-01-01

Higher or multiple-harmonic acceleration drives in synchrotrons are desirable, when passing the transition point, applying stochastic cooling on a bunched beam, or for many other longitudinal beam manipulations, as bunch stretching or compression. As proof-of-principle, virtually arbitrary, digitally synthesized voltage waveforms, employing contents up to fourth harmonic in the range 0.2-8 MHz, could be generated at the gap of one single (symmetric re-entrant) cavity, filled with discs of the novel ferritic amorphous metal VITROVAC of VAC, Hanau. A 10 kW amplifier produces voltages in the kV-range. As relevant examples, we achieved a flat-top waveform suitable for the transition (+27 deg, 10 -3 max. error), a fourth-order flattened bucket for bunched-beam cooling, and a harmonic bucket with linear restoring force. The compact cavity system should be well suited for any proton or heavy ion device operating in this frequency range, and therapy-oriented rings. (author). 9 refs., 6 figs

Second harmonic generation in a bounded magnetoplasma

International Nuclear Information System (INIS)

Thomas, D.G.

1975-01-01

An experimental study of second harmonic generation in a magnetized plasma contained in a cylindrical cavity resonator shows how the harmonic power varies with fundamental power, background gas pressure, and magnetization. Two cavities were designed. For each the TM010 resonance was in the S-band and the TM011 resonance in the C-band. Both frequencies were harmonically related when the d.c. discharge sustaining the plasma was adjusted to give plasma frequencies of approximately 0.7 GHz and 1.53 GHz. The experimental results show the harmonic power approximately proportional to the square of the fundamental power from 5 to 100 mw, and a decreasing function of pressure from 10 to 150 millitorr. Experiments at constant plasma frequency and varying magnetic field from 0 to 3000 Gauss show a sharp drop in harmonic power to undetectable levels when the electron cyclotron frequency approximates either the fundamental or second harmonic frequencies. These effects are attributed, respectively, to the coupling of fundamental power to other modes and to cavity detuning away from the harmonic. With the plasma frequency adjusted to maintain simultaneous resonance of fundamental and harmonic, a harmonic signal maximum occurred when the upper hybrid frequency approximated the harmonic frequency. Several anomalies, apparently related to the magnetization, background gas, and electron density distribution were observed. Otherwise, the results are qualitatively consistent with the first order theory for a cold, collisional plasma

Physics of tissue harmonic imaging by ultrasound

Science.gov (United States)

Jing, Yuan

Tissue Harmonic Imaging (THI) is an imaging modality that is currently deployed on diagnostic ultrasound scanners. In THI the amplitude of the ultrasonic pulse that is used to probe the tissue is large enough that the pulse undergoes nonlinear distortion as it propagates into the tissue. One result of the distortion is that as the pulse propagates energy is shifted from the fundamental frequency of the source pulse into its higher harmonics. These harmonics will scatter off objects in the tissue and images formed from the scattered higher harmonics are considered to have superior quality to the images formed from the fundamental frequency. Processes that have been suggested as possibly responsible for the improved imaging in THI include: (1) reduced sensitivity to reverberation, (2) reduced sensitivity to aberration, and (3) reduction in side lobes. By using a combination of controlled experiments and numerical simulations, these three reasons have been investigated. A single element transducer and a clinical ultrasound scanner with a phased array transducer were used to image a commercial tissue-mimicking phantom with calibrated targets. The higher image quality achieved with THI was quantified in terms of spatial resolution and "clutter" signals. A three-dimensional model of the forward propagation of nonlinear sound beams in media with arbitrary spatial properties (a generalized KZK equation) was developed. A time-domain code for solving the KZK equation was validated with measurements of the acoustic field generated by the single element transducer and the phased array transducer. The code was used to investigate the impact of aberration using tissue-like media with three-dimensional variations in all acoustic properties. The three-dimensional maps of tissue properties were derived from the datasets available through the Visible Female project. The experiments and simulations demonstrated that second harmonic imaging (1) suffers less clutter associated with

Rotation harmonics for a numerical diatomic potential

International Nuclear Information System (INIS)

Kobeissi, H.; Korek, M.

1983-01-01

The problem of the determination of the rotation harmonics phi 1 , phi 2 , ... for the case of a numerical diatomic potential is considered. These harmonics defined in a recent work by psisub(vJ) = psisub(vO) + lambda 2 phi 2 + ... (where psisub(vJ) is the wave function of the vibration level v and the rotation level J, and lambda = J(J+1)) are studied for the case of the Dunham potential and for a numerical potential defined by the coordinates of its turning points with polynomial interpolations and extrapolations. It is proved that the analytical expressions of the harmonics phi 1 , phi 2 , ... reduce to polynomials where the coefficients are simply related to those of the potential in the case of the Dunham potential, and to the coordinates of the turning points in the case of the numerical potential. The numerical application is simple. The examples presented show that the vibration-rotation wave function psisub(vJ) calculated by using two harmonics only is ''exact'' up to eight significant figures

Nonlinear Schrödinger equations with single power nonlinearity and harmonic potential

Science.gov (United States)

Cipolatti, R.; de Macedo Lira, Y.; Trallero-Giner, C.

2018-03-01

We consider a generalized nonlinear Schrödinger equation (GNLS) with a single power nonlinearity of the form λ ≤ft\\vert \\varphi \\right\\vert p , with p  >  0 and λ\\in{R} , in the presence of a harmonic confinement. We report the conditions that p and λ must fulfill for the existence and uniqueness of ground states of the GNLS. We discuss the Cauchy problem and summarize which conditions are required for the nonlinear term λ ≤ft\\vert \\varphi \\right\\vert p to render the ground state solutions orbitally stable. Based on a new variational method we provide exact formulæ for the minimum energy for each index p and the changing range of values of the nonlinear parameter λ. Also, we report an approximate close analytical expression for the ground state energy, performing a comparative analysis of the present variational calculations with those obtained by a generalized Thomas-Fermi approach, and soliton solutions for the respective ranges of p and λ where these solutions can be implemented to describe the minimum energy.

Near-field second-harmonic generation from gold nanoellipsoids

Energy Technology Data Exchange (ETDEWEB)

Celebrano, M; Zavelani-Rossi, M; Polli, D; Cerullo, G [Istituto di Fotonica e Nanotecnologie, CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Biagioni, P; Finazzi, M; Duo, L [LNESS - Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano (Italy); Labardi, M; Allegrini, M [CNR-INFM, polyLab, Dipartimento di Fisica ' Enrico Fermi' , Universita di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Grand, J; Adam, P M; Royer, P [Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de Technologie de Troyes, 12 rue Marie Curie, BP 2060 10010 Troyes cedex (France)

2008-07-01

Second-harmonic generation from single gold nanofabricated particles is experimentally investigated by a nonlinear scanning near-field optical microscope (SNOM). High peak power femtosecond polarized light pulses at the output of a hollow pyramid aperture allow for efficient second-harmonic imaging, with sub-100-nm spatial resolution and high contrast. The near-field nonlinear response is found to be directly related to both local surface plasmon resonances and particle morphology. The combined analysis of linear and second-harmonic SNOM images allows one to discriminate among near-field scattering, absorption and re-emission processes, which would not be possible with linear techniques alone. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Second harmonic generation in a molecular magnetic chain

Science.gov (United States)

Cavigli, L.; Sessoli, R.; Gurioli, M.; Bogani, L.

2006-05-01

A setup for the determination of all the components of the second harmonic generation tensor in molecular materials is presented. It allows overcoming depletion problems, which one can expect to be common in molecular systems. A preliminary characterization of the nonlinear properties of the single chain magnet CoPhOMe is carried out. We observe a high second harmonic signal, comparable to that of urea, and show that the bulk contributions are dominant over the surface ones.

Exact quantum solutions for some asymmetrical two-well potentials

International Nuclear Information System (INIS)

Ley-Koo, E.

1985-01-01

We discuss several points of interest in the study of two-well potentials in quantum mechanics courses. In particular, we construct the solutions of the Schroedinger equation for rectangular-well, harmonic-oscillator and triangular-well potentials with a delta-function potential superimposed in different positions. The energy spectra and eigenfunctions of such systems are presented and analyzed for different intensities and positions of the delta-function potential. (author)

Harmonic synchronization in resistively coupled Josephson junctions

International Nuclear Information System (INIS)

Blackburn, J.A.; Gronbech-Jensen, N.; Smith, H.J.T.

1994-01-01

The oscillations of two resistively coupled Josephson junctions biased only by a single dc current source are shown to lock harmonically in a 1:2 mode over a significant range of bias current, even when the junctions are identical. The dependence of this locking on both junction and coupling parameters is examined, and it is found that, for this particular two-junction configuration, 1:1 locking can never occur, and also that a minimum coupling coefficient is needed to support harmonic locking. Some issues related to subharmonic locking are also discussed

High-Intensity High-order Harmonics Generated from Low-Density Plasma

International Nuclear Information System (INIS)

Ozaki, T.; Bom, L. B. Elouga; Abdul-Hadi, J.; Ganeev, R. A.; Haessler, S.; Salieres, P.

2009-01-01

We study the generation of high-order harmonics from lowly ionized plasma, using the 10 TW, 10 Hz laser of the Advanced Laser Light Source (ALLS). We perform detailed studies on the enhancement of a single order of the high-order harmonic spectrum generated in plasma using the fundamental and second harmonic of the ALLS beam line. We observe quasi-monochromatic harmonics for various targets, including Mn, Cr, Sn, and In. We identify most of the ionic/neutral transitions responsible for the enhancement, which all have strong oscillator strengths. We demonstrate intensity enhancements of the 13th, 17th, 29th, and 33rd harmonics from these targets using the 800 nm pump laser and varying its chirp. We also characterized the attosecond nature of such plasma harmonics, measuring attosecond pulse trains with 360 as duration for chromium plasma, using the technique of ''Reconstruction of Attosecond Beating by Interference of Two-photon Transitions''(RABBIT). These results show that plasma harmonics are intense source of ultrashort coherent soft x-rays.

Harmonics rejection in pixelated interferograms using spatio-temporal demodulation.

Science.gov (United States)

Padilla, J M; Servin, M; Estrada, J C

2011-09-26

Pixelated phase-mask interferograms have become an industry standard in spatial phase-shifting interferometry. These pixelated interferograms allow full wavefront encoding using a single interferogram. This allows the study of fast dynamic events in hostile mechanical environments. Recently an error-free demodulation method for ideal pixelated interferograms was proposed. However, non-ideal conditions in interferometry may arise due to non-linear response of the CCD camera, multiple light paths in the interferometer, etc. These conditions generate non-sinusoidal fringes containing harmonics which degrade the phase estimation. Here we show that two-dimensional Fourier demodulation of pixelated interferograms rejects most harmonics except the complex ones at {-3(rd), +5(th), -7(th), +9(th), -11(th),…}. We propose temporal phase-shifting to remove these remaining harmonics. In particular, a 2-step phase-shifting algorithm is used to eliminate the -3(rd) and +5(th) complex harmonics, while a 3-step one is used to remove the -3(rd), +5harmonics. © 2011 Optical Society of America

Spectral inverse problem for q-deformed harmonic oscillator

Indian Academy of Sciences (India)

The supersymmetric quantization condition is used to study the wave functions of SWKB equivalent -deformed harmonic oscillator which are obtained by using only the knowledge of bound-state spectra of -deformed harmonic oscillator. We have also studied the nonuniqueness of the obtained interactions by this ...

Harmonic Content of the BESSY FEL Radiation

CERN Document Server

Meseck, Atoosa

2005-01-01

BESSY proposes a linac-based cascaded High-Gain Harmonic-Generation (HGHG) free electron laser (FEL) multi-user facility. The BESSY soft X-ray FEL will consist of three undulator lines. The associated tunable lasers will cover the spectral range of 230nm to 460nm. Two to four HGHG stages reduce the seed wavelength to the desired radiation range of 1.24nm < λ < 51nm. The harmonic content of the high-intensity radiator output can be used to reduce the number of necessary HGHG stages. Moreover the higher harmonic content of the final output extends the offered spectral range and thus is of high interest for the user community. In this paper, the higher harmonic content of the final output as well as of the output of several radiators are investigated. The main parameters such as output power, pulse duration and bandwidth as well as their suitability for seeding are discussed.

Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

Science.gov (United States)

Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

2015-11-17

We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform.

High-order harmonic generation with short-pulse lasers

International Nuclear Information System (INIS)

Schafer, K.J.; Krause, J.L.; Kulander, K.C.

1992-12-01

Recent progress in the understanding of high-order harmonic conversion from atoms and ions exposed to high-intensity, short-pulse optical lasers is reviewed. We find that ions can produce harmonics comparable in strength to those obtained from neutral atoms, and that the emission extends to much higher order. Simple scaling laws for the strength of the harmonic emission and the maximium observable harmonic are suggested. These results imply that the photoemission observed in recent experiments in helium and neon contains contributions from ions as well as neutrals

Embedded harmonic control for dynamic trajectory planning on FPGA

OpenAIRE

Girau , Bernard; Boumaza , Amine

2007-01-01

International audience; This paper presents a parallel hardware implementation of a well-known navigation control method on reconfigurable digital circuits. Trajectories are estimated after an iterated computation of the harmonic functions, given the goal and obstacle positions of the navigation problem. The proposed massively distributed implementation locally computes the direction to choose to get to the goal position at any point of the environment. Changes in this environment may be imme...

Analytic model of bunched beams for harmonic generation in the low-gain free electron laser regime

Directory of Open Access Journals (Sweden)

G. Penn

2006-06-01

Full Text Available One scheme for harmonic generation employs free electron lasers (FELs with two undulators: the first uses a seed laser to modulate the energy of the electron beam; following a dispersive element which acts to bunch the beam, the second undulator radiates at a higher harmonic. These processes are currently evaluated using extensive calculations or simulation codes which can be slow to evaluate and difficult to set up. We describe a simple algorithm to predict the output of a harmonic generation beam line in the low-gain FEL regime, based on trial functions for the output radiation. Full three-dimensional effects are included. This method has been implemented as a Mathematica® package, named CAMPANILE, which runs rapidly and can be generalized to include effects such as asymmetric beams and misalignments. This method is compared with simulation results using the FEL code GENESIS, both for single stages of harmonic generation and for the LUX project, a design concept for an ultrafast x-ray facility, where multiple stages upshift the input laser frequency by factors of up to 200.

Mitigation of Harmonics in Grid-Connected and Islanded Microgrids via Virtual Admittances and Impedances

DEFF Research Database (Denmark)

Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril

2017-01-01

Optimization of the islanded and grid-connected operation of microgrids is important to achieve a high degree of reliability. In this paper, the authors consider the effect of current harmonics in single phase microgrids during both modes of operation. A detailed analysis of the effect of the out......Optimization of the islanded and grid-connected operation of microgrids is important to achieve a high degree of reliability. In this paper, the authors consider the effect of current harmonics in single phase microgrids during both modes of operation. A detailed analysis of the effect...... of the output impedance of the considered primary control loops on the harmonic output of the considered voltage source inverters is initially carried out. A virtual admittance loop is proposed to attenuate the current harmonic output in grid-connected operation that is generated due to the grid voltage...... distortion present at the point of common coupling (PCC) and due to local non-linear loads. This paper also considers the harmonic current sharing and resulting voltage harmonics at the PCC during islanded operation of the microgrid. A capacitive virtual impedance loop was implemented to improve the harmonic...

Harmonic statistics

International Nuclear Information System (INIS)

Eliazar, Iddo

2017-01-01

The exponential, the normal, and the Poisson statistical laws are of major importance due to their universality. Harmonic statistics are as universal as the three aforementioned laws, but yet they fall short in their ‘public relations’ for the following reason: the full scope of harmonic statistics cannot be described in terms of a statistical law. In this paper we describe harmonic statistics, in their full scope, via an object termed harmonic Poisson process: a Poisson process, over the positive half-line, with a harmonic intensity. The paper reviews the harmonic Poisson process, investigates its properties, and presents the connections of this object to an assortment of topics: uniform statistics, scale invariance, random multiplicative perturbations, Pareto and inverse-Pareto statistics, exponential growth and exponential decay, power-law renormalization, convergence and domains of attraction, the Langevin equation, diffusions, Benford’s law, and 1/f noise. - Highlights: • Harmonic statistics are described and reviewed in detail. • Connections to various statistical laws are established. • Connections to perturbation, renormalization and dynamics are established.

Harmonic statistics

Energy Technology Data Exchange (ETDEWEB)

Eliazar, Iddo, E-mail: eliazar@post.tau.ac.il

2017-05-15

The exponential, the normal, and the Poisson statistical laws are of major importance due to their universality. Harmonic statistics are as universal as the three aforementioned laws, but yet they fall short in their ‘public relations’ for the following reason: the full scope of harmonic statistics cannot be described in terms of a statistical law. In this paper we describe harmonic statistics, in their full scope, via an object termed harmonic Poisson process: a Poisson process, over the positive half-line, with a harmonic intensity. The paper reviews the harmonic Poisson process, investigates its properties, and presents the connections of this object to an assortment of topics: uniform statistics, scale invariance, random multiplicative perturbations, Pareto and inverse-Pareto statistics, exponential growth and exponential decay, power-law renormalization, convergence and domains of attraction, the Langevin equation, diffusions, Benford’s law, and 1/f noise. - Highlights: • Harmonic statistics are described and reviewed in detail. • Connections to various statistical laws are established. • Connections to perturbation, renormalization and dynamics are established.

Tracking the harmonic response of magnetically-soft sensors for wireless temperature, stress, and corrosive monitoring

Science.gov (United States)

Ong, Keat G.; Grimes, Craig A.

2002-01-01

This paper describes the application of magnetically-soft ribbon-like sensors for measurement of temperature and stress, as well as corrosive monitoring, based upon changes in the amplitudes of the higher-order harmonics generated by the sensors in response to a magnetic interrogation signal. The sensors operate independently of mass loading, and so can be placed or rigidly embedded inside nonmetallic, opaque structures such as concrete or plastic. The passive harmonic-based sensor is remotely monitored through a single coplanar interrogation and detection coil. Effects due to the relative location of the sensor are eliminated by tracking harmonic amplitude ratios, thereby, enabling wide area monitoring. The wireless, passive, mass loading independent nature of the described sensor platform makes it ideally suited for long-term structural monitoring applications, such as measurement of temperature and stress inside concrete structures. A theoretical model is presented to explain the origin and behavior of the higher-order harmonics in response to temperature and stress. c2002 Elsevier Science B.V. All rights reserved.

Functional design criteria for the self-installing liquid observation well

International Nuclear Information System (INIS)

Parra, S.A.

1996-01-01

This document presents the functional Design Criteria for installing liquid observation wells (LOWs) into single-shell tanks containing ferrocyanide and organic wastes. The LOWs will be designed to accommodate the deployment of gamma, neutron, and electromagnetic induction probes and to interface with the existing tank structure and environment

Optimal control of a harmonic oscillator: Economic interpretations

Science.gov (United States)

Janová, Jitka; Hampel, David

2013-10-01

Optimal control is a popular technique for modelling and solving the dynamic decision problems in economics. A standard interpretation of the criteria function and Lagrange multipliers in the profit maximization problem is well known. On a particular example, we aim to a deeper understanding of the possible economic interpretations of further mathematical and solution features of the optimal control problem: we focus on the solution of the optimal control problem for harmonic oscillator serving as a model for Phillips business cycle. We discuss the economic interpretations of arising mathematical objects with respect to well known reasoning for these in other problems.

A toolbox for Harmonic Sums and their analytic continuations

Energy Technology Data Exchange (ETDEWEB)

Ablinger, Jakob; Schneider, Carsten [RISC, J. Kepler University, Linz (Austria); Bluemlein, Johannes [DESY, Zeuthen (Germany)

2010-07-01

The package HarmonicSums implemented in the computer algebra system Mathematica is presented. It supports higher loop calculations in QCD and QED to represent single-scale quantities like anomalous dimensions and Wilson coefficients. The package allows to reduce general harmonic sums due to their algebraic and different structural relations. We provide a general framework for these reductions and the explicit representations up to weight w=8. For the use in experimental analyzes we also provide an analytic formalism to continue the harmonic sums form their integer arguments into the complex plane, which includes their recursions and asymptotic representations. The main ideas are illustrated by specific examples.

Comparative analysis of gyrotron backward-wave oscillators operating at different cyclotron harmonics

International Nuclear Information System (INIS)

Yeh, Y.S.; Chang, T.H.; Wu, T.S.

2004-01-01

A comparative analysis between the fundamental and second cyclotron harmonics of gyrotron backward-wave oscillators (gyro-BWOs) is presented. The simulation results reveal that nonlinear field contraction is a common feature for both harmonic interactions. Besides, the electron transit angle, used to characterize the axial modes of the fundamental harmonic TE 11 mode at the start-oscillation conditions, is found to be applicable even for the second harmonic TE 21 mode. Each axial mode of either the fundamental harmonic TE 11 or the second harmonic TE 21 modes is maintained at a constant value of the electron transit angle while changing the operating parameters, such as magnetic field and beam voltage. Extensive numerical calculations are conducted for the start-oscillation currents and tuning properties. Moreover, single-mode operating regimes are suggested where the second harmonic TE 21 gyro-BWO could generate a considerable output power, comparing with the fundamental harmonic TE 11 gyro-BWO

Derivation of exact master equation with stochastic description: dissipative harmonic oscillator.

Science.gov (United States)

Li, Haifeng; Shao, Jiushu; Wang, Shikuan

2011-11-01

A systematic procedure for deriving the master equation of a dissipative system is reported in the framework of stochastic description. For the Caldeira-Leggett model of the harmonic-oscillator bath, a detailed and elementary derivation of the bath-induced stochastic field is presented. The dynamics of the system is thereby fully described by a stochastic differential equation, and the desired master equation would be acquired with statistical averaging. It is shown that the existence of a closed-form master equation depends on the specificity of the system as well as the feature of the dissipation characterized by the spectral density function. For a dissipative harmonic oscillator it is observed that the correlation between the stochastic field due to the bath and the system can be decoupled, and the master equation naturally results. Such an equation possesses the Lindblad form in which time-dependent coefficients are determined by a set of integral equations. It is proved that the obtained master equation is equivalent to the well-known Hu-Paz-Zhang equation based on the path-integral technique. The procedure is also used to obtain the master equation of a dissipative harmonic oscillator in time-dependent fields.

A Method for Harmonic Sources Detection based on Harmonic Distortion Power Rate

Science.gov (United States)

Lin, Ruixing; Xu, Lin; Zheng, Xian

2018-03-01

Harmonic sources detection at the point of common coupling is an essential step for harmonic contribution determination and harmonic mitigation. The harmonic distortion power rate index is proposed for harmonic source location based on IEEE Std 1459-2010 in the paper. The method only based on harmonic distortion power is not suitable when the background harmonic is large. To solve this problem, a threshold is determined by the prior information, when the harmonic distortion power is larger than the threshold, the customer side is considered as the main harmonic source, otherwise, the utility side is. A simple model of public power system was built in MATLAB/Simulink and field test results of typical harmonic loads verified the effectiveness of proposed method.

Wavelength and intensity dependence of recollision-enhanced multielectron effects in high-order harmonic generation

Science.gov (United States)

Abanador, Paul M.; Mauger, François; Lopata, Kenneth; Gaarde, Mette B.; Schafer, Kenneth J.

2018-04-01

Using a model molecular system (A2) with two active electrons restricted to one dimension, we examine high-order harmonic generation (HHG) enhanced by rescattering. Our results show that even at intensities well below the single ionization saturation, harmonics generated from the cation (A2+ ) can be significantly enhanced due to the rescattering of the electron that is initially ionized. This two-electron effect is manifested by the appearance of a secondary plateau and cutoff in the HHG spectrum, extending beyond the predicted cutoff in the single active electron approximation. We use our molecular model to investigate the wavelength dependence of rescattering enhanced HHG, which was first reported in a model atomic system [I. Tikhomirov, T. Sato, and K. L. Ishikawa, Phys. Rev. Lett. 118, 203202 (2017), 10.1103/PhysRevLett.118.203202]. We demonstrate that the HHG yield in the secondary cutoff is highly sensitive to the available electron rescattering energies as indicated by a dramatic scaling with respect to driving wavelength.

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

DEFF Research Database (Denmark)

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

2018-01-01

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

Single-site Green function of the Dirac equation for full-potential electron scattering

Energy Technology Data Exchange (ETDEWEB)

Kordt, Pascal

2012-05-30

I present an elaborated analytical examination of the Green function of an electron scattered at a single-site potential, for both the Schroedinger and the Dirac equation, followed by an efficient numerical solution, in both cases for potentials of arbitrary shape without an atomic sphere approximation. A numerically stable way to calculate the corresponding regular and irregular wave functions and the Green function is via the angular Lippmann-Schwinger integral equations. These are solved based on an expansion in Chebyshev polynomials and their recursion relations, allowing to rewrite the Lippmann-Schwinger equations into a system of algebraic linear equations. Gonzales et al. developed this method for the Schroedinger equation, where it gives a much higher accuracy compared to previous perturbation methods, with only modest increase in computational effort. In order to apply it to the Dirac equation, I developed relativistic Lippmann-Schwinger equations, based on a decomposition of the potential matrix into spin spherical harmonics, exploiting certain properties of this matrix. The resulting method was embedded into a Korringa-Kohn-Rostoker code for density functional calculations. As an example, the method is applied by calculating phase shifts and the Mott scattering of a tungsten impurity. (orig.)

Single-site Green function of the Dirac equation for full-potential electron scattering

International Nuclear Information System (INIS)

Kordt, Pascal

2012-01-01

I present an elaborated analytical examination of the Green function of an electron scattered at a single-site potential, for both the Schroedinger and the Dirac equation, followed by an efficient numerical solution, in both cases for potentials of arbitrary shape without an atomic sphere approximation. A numerically stable way to calculate the corresponding regular and irregular wave functions and the Green function is via the angular Lippmann-Schwinger integral equations. These are solved based on an expansion in Chebyshev polynomials and their recursion relations, allowing to rewrite the Lippmann-Schwinger equations into a system of algebraic linear equations. Gonzales et al. developed this method for the Schroedinger equation, where it gives a much higher accuracy compared to previous perturbation methods, with only modest increase in computational effort. In order to apply it to the Dirac equation, I developed relativistic Lippmann-Schwinger equations, based on a decomposition of the potential matrix into spin spherical harmonics, exploiting certain properties of this matrix. The resulting method was embedded into a Korringa-Kohn-Rostoker code for density functional calculations. As an example, the method is applied by calculating phase shifts and the Mott scattering of a tungsten impurity. (orig.)

High-frequency harmonic imaging of the eye

Science.gov (United States)

Silverman, Ronald H.; Coleman, D. Jackson; Ketterling, Jeffrey A.; Lizzi, Frederic L.

2005-04-01

Purpose: Harmonic imaging has become a well-established technique for ultrasonic imaging at fundamental frequencies of 10 MHz or less. Ophthalmology has benefited from the use of fundamentals of 20 MHz to 50 MHz. Our aim was to explore the ability to generate harmonics for this frequency range, and to generate harmonic images of the eye. Methods: The presence of harmonics was determined in both water and bovine vitreous propagation media by pulse/echo and hydrophone at a series of increasing excitation pulse intensities and frequencies. Hydrophone measurements were made at the focal point and in the near- and far-fields of 20 MHz and 40 MHz transducers. Harmonic images of the anterior segment of the rabbit eye were obtained by a combination of analog filtering and digital post-processing. Results: Harmonics were generated nearly identically in both water and vitreous. Hydrophone measurements showed the maximum second harmonic to be -5 dB relative to the 35 MHz fundamental at the focus, while in pulse/echo the maximum harmonic amplitude was -15dB relative to the fundamental. Harmonics were absent in the near-field, but present in the far-field. Harmonic images of the eye showed improved resolution. Conclusion: Harmonics can be readily generated at very high frequencies, and at power levels compliant with FDA guidelines for ophthalmology. This technique may yield further improvements to the already impressive resolutions obtainable in this frequency range. Improved imaging of the macular region, in particular, may provide significant improvements in diagnosis of retinal disease.

One-Year Linear Trajectories of Symptoms, Physical Functioning, Cognitive Functioning, Emotional Well-being, and Spiritual Well-being Among Patients Receiving Dialysis.

Science.gov (United States)

Song, Mi-Kyung; Paul, Sudeshna; Ward, Sandra E; Gilet, Constance A; Hladik, Gerald A

2018-01-25

This study evaluated 1-year linear trajectories of patient-reported dimensions of quality of life among patients receiving dialysis. Longitudinal observational study. 227 patients recruited from 12 dialysis centers. Sociodemographic and clinical characteristics. Participants completed an hour-long interview monthly for 12 months. Each interview included patient-reported outcome measures of overall symptoms (Edmonton Symptom Assessment System), physical functioning (Activities of Daily Living/Instrumental Activities of Daily Living), cognitive functioning (Patient's Assessment of Own Functioning Inventory), emotional well-being (Center for Epidemiologic Studies Depression Scale, State Anxiety Inventory, and Positive and Negative Affect Schedule), and spiritual well-being (Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale). For each dimension, linear and generalized linear mixed-effects models were used. Linear trajectories of the 5 dimensions were jointly modeled as a multivariate outcome over time. Although dimension scores fluctuated greatly from month to month, overall symptoms, cognitive functioning, emotional well-being, and spiritual well-being improved over time. Older compared with younger participants reported higher scores across all dimensions (all Pspiritual well-being compared with their white counterparts (P<0.01). Clustering analysis of dimension scores revealed 2 distinctive clusters. Cluster 1 was characterized by better scores than those of cluster 2 in nearly all dimensions at baseline and by gradual improvement over time. Study was conducted in a single region of the United States and included mostly patients with high levels of function across the dimensions of quality of life studied. Multidimensional patient-reported quality of life varies widely from month to month regardless of whether overall trajectories improve or worsen over time. Additional research is needed to identify the best approaches to incorporate

Harmonic generation with multiple wiggler schemes

Energy Technology Data Exchange (ETDEWEB)

Bonifacio, R.; De Salvo, L.; Pierini, P. [Universita degli Studi, Milano (Italy)

1995-02-01

In this paper the authors give a simple theoretical description of the basic physics of the single pass high gain free electron laser (FEL), describing in some detail the FEL bunching properties and the harmonic generation technique with a multiple-wiggler scheme or a high gain optical klystron configuration.

Benefits from the BESSY FEL Higher Harmonic Radiation

CERN Document Server

Goldammer, K

2005-01-01

In the FEL process, bunching and coherent radiation is produced at the fundamental frequency as well as its higher harmonics. BESSY proposes a linac-based cascaded High-Gain Harmonic-Generation (HGHG) free electron laser (FEL) multi-user facility. The BESSY soft X-ray FEL will be seeded by three lasers spanning the spectral range of 230nm to 460nm. Two to four HGHG stages downconvert the seed wavelength to the desired radiation range of 1.24nm to 51nm using higher harmonic bunching. As a surplus, higher harmonic radiation is intrinsically produced in each FEL stage. Radiation on a higher harmonic of the FEL frequency is of high interest because it yields the possibility to reduce the number of FEL stages. This paper details extensive studies of the higher harmonic content of the BESSY FEL radiation. Important aspects of FEL interaction on higher harmonics as resulting from theory and from numerical simulations are discussed. For the case of the BESSY FEL, methods for improving the harmonic content are present...

Statistical Analysis and Comparison of Harmonics Measured in Offshore Wind Farms

DEFF Research Database (Denmark)

Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

2011-01-01

The paper shows statistical analysis of harmonic components measured in different offshore wind farms. Harmonic analysis is a complex task and requires many aspects, such as measurements, data processing, modeling, validation, to be taken into consideration. The paper describes measurement process...... and shows sophisticated analysis on representative harmonic measurements from Avedøre Holme, Gunfleet Sands and Burbo Bank wind farms. The nature of generation and behavior of harmonic components in offshore wind farms clearly presented and explained based on probabilistic approach. Some issues regarding...... commonly applied standards are also put forward in the discussion. Based on measurements and data analysis it is shown that a general overview about wind farm harmonic behaviour cannot be fully observed only based on single-value measurements as suggested in the standards but using more descriptive...

Harmonic Analyzing of the Double PWM Converter in DFIG Based on Mathematical Model

Directory of Open Access Journals (Sweden)

Jing Liu

2017-12-01

Full Text Available Harmonic pollution of double fed induction generators (DFIGs has become a vital concern for its undesirable effects on power quality issues of wind generation systems and grid-connected system, and the double pulse width modulation (PWMconverter is one of the main harmonic sources in DFIGs. Thus the harmonic analysis of the converter in DFIGs is a necessary step to evaluate their harmonic pollution of DFIGs. This paper proposes a detailed harmonic modeling method to discuss the main harmonic components in a converter. In general the harmonic modeling could be divided into the low-order harmonic part (up to 30th order and the high-order harmonic part (greater than order 30 parts in general. The low-order harmonics are produced by the circuit topology and control algorithm, and the harmonic component will be different if the control strategy changes. The high-order harmonics are produced by the modulation of the switching function to the dc variable. In this paper, the low-order harmonic modeling is established according to the directions of power flow under the vector control (VC, and the high-order harmonic modeling is established by the switching function of space vector PWM and dc currents. Meanwhile, the simulations of harmonic a components in a converter are accomplished in a real time digital simulation system. The results indicate that the proposed modeling could effectively show the harmonics distribution of the converter in DFIGs.

Studies of harmonic generation in free electron lasers

International Nuclear Information System (INIS)

Goldammer, K.

2007-01-01

Nonlinear harmonic generation is one of the most interesting aspects of Free Electron Lasers under study today. It provides for coherent, high intensity radiation at higher harmonics of the FEL resonant frequency. The sources, numerical simulation and applications of harmonic radiation in cascaded High Gain Harmonic Generation FELs were the subject of this thesis. Harmonic emission in FELs originates from harmonic microbunching of the particles and the particular electron trajectory during FEL interaction. Numerical FEL simulation codes model these analytical equations and predict the performance of Free Electron Lasers with good accuracy. This thesis has relied heavily upon the FEL simulation code Genesis 1.3 which has been upgraded in the framework of this thesis to compute harmonic generation in a self-consistent manner. Tests against analytical predictions suggest that the harmonic power levels as well as harmonic gain lengths are simulated correctly. A benchmark with the FEL simulation code GINGER yields excellent agreement of the harmonic saturation length and saturation power. The new version of the simulation code Genesis was also tested against measurements from the VUV-FEL FLASH at DESY. The spectral power distributions of fundamental and third harmonic radiation were recorded at 25.9 nm and 8.6 nm, respectively. The relative bandwidths (FWHM) were in the range of 2 % for both the fundamental as well as the third harmonic, which was accurately reproduced by time-dependent simulations with Genesis. The new code was also used to propose and evaluate a new design for the BESSY Soft X-Ray FEL, a cascaded High Gain Harmonic Generation FEL proposed by BESSY in Berlin. The original design for the BESSY High Energy FEL line requires four HGHG stages to convert the initial seed laser wavelength of 297.5 nm down to 1.24 nm. A new scheme is proposed that makes use of fifth harmonic radiation from the first stage and reduces the number of HGHG stages to three. It

Studies of harmonic generation in free electron lasers

Energy Technology Data Exchange (ETDEWEB)

Goldammer, K.

2007-11-12

Nonlinear harmonic generation is one of the most interesting aspects of Free Electron Lasers under study today. It provides for coherent, high intensity radiation at higher harmonics of the FEL resonant frequency. The sources, numerical simulation and applications of harmonic radiation in cascaded High Gain Harmonic Generation FELs were the subject of this thesis. Harmonic emission in FELs originates from harmonic microbunching of the particles and the particular electron trajectory during FEL interaction. Numerical FEL simulation codes model these analytical equations and predict the performance of Free Electron Lasers with good accuracy. This thesis has relied heavily upon the FEL simulation code Genesis 1.3 which has been upgraded in the framework of this thesis to compute harmonic generation in a self-consistent manner. Tests against analytical predictions suggest that the harmonic power levels as well as harmonic gain lengths are simulated correctly. A benchmark with the FEL simulation code GINGER yields excellent agreement of the harmonic saturation length and saturation power. The new version of the simulation code Genesis was also tested against measurements from the VUV-FEL FLASH at DESY. The spectral power distributions of fundamental and third harmonic radiation were recorded at 25.9 nm and 8.6 nm, respectively. The relative bandwidths (FWHM) were in the range of 2 % for both the fundamental as well as the third harmonic, which was accurately reproduced by time-dependent simulations with Genesis. The new code was also used to propose and evaluate a new design for the BESSY Soft X-Ray FEL, a cascaded High Gain Harmonic Generation FEL proposed by BESSY in Berlin. The original design for the BESSY High Energy FEL line requires four HGHG stages to convert the initial seed laser wavelength of 297.5 nm down to 1.24 nm. A new scheme is proposed that makes use of fifth harmonic radiation from the first stage and reduces the number of HGHG stages to three. It

Development of a suspended-mass RSE interferometer using third harmonic demodulation

CERN Document Server

Miyakawa, O; Heinzel, G; Kawamura, S

2002-01-01

The most important point of a resonant sideband extraction (RSE) experiment is the signal extraction for control of the interferometer. We proposed a new signal-sensing method for the single modulation scheme. This method uses the third harmonic demodulation (THD) with a particular asymmetry in the interferometer which makes the third-order sidebands vanish at the detecting port. We have successfully locked a suspended-mass RSE interferometer for the first time by the THD method. The transfer function of the interferometer was measured to confirm the RSE effect.

Development of a suspended-mass RSE interferometer using third harmonic demodulation

International Nuclear Information System (INIS)

Miyakawa, Osamu; Somiya, Kentaro; Heinzel, Gerhard; Kawamura, Seiji

2002-01-01

The most important point of a resonant sideband extraction (RSE) experiment is the signal extraction for control of the interferometer. We proposed a new signal-sensing method for the single modulation scheme. This method uses the third harmonic demodulation (THD) with a particular asymmetry in the interferometer which makes the third-order sidebands vanish at the detecting port. We have successfully locked a suspended-mass RSE interferometer for the first time by the THD method. The transfer function of the interferometer was measured to confirm the RSE effect

A statistically harmonized alignment-classification in image space enables accurate and robust alignment of noisy images in single particle analysis.

Science.gov (United States)

Kawata, Masaaki; Sato, Chikara

2007-06-01

In determining the three-dimensional (3D) structure of macromolecular assemblies in single particle analysis, a large representative dataset of two-dimensional (2D) average images from huge number of raw images is a key for high resolution. Because alignments prior to averaging are computationally intensive, currently available multireference alignment (MRA) software does not survey every possible alignment. This leads to misaligned images, creating blurred averages and reducing the quality of the final 3D reconstruction. We present a new method, in which multireference alignment is harmonized with classification (multireference multiple alignment: MRMA). This method enables a statistical comparison of multiple alignment peaks, reflecting the similarities between each raw image and a set of reference images. Among the selected alignment candidates for each raw image, misaligned images are statistically excluded, based on the principle that aligned raw images of similar projections have a dense distribution around the correctly aligned coordinates in image space. This newly developed method was examined for accuracy and speed using model image sets with various signal-to-noise ratios, and with electron microscope images of the Transient Receptor Potential C3 and the sodium channel. In every data set, the newly developed method outperformed conventional methods in robustness against noise and in speed, creating 2D average images of higher quality. This statistically harmonized alignment-classification combination should greatly improve the quality of single particle analysis.

Effects of external magnetic field on harmonics generated in laser interaction with underdense plasma

International Nuclear Information System (INIS)

Faghihi-Nik, M.; Ghorbanalilu, M.; Shokri, B.

2010-01-01

Complete text of publication follows. Generation of harmonic radiation is an important subject of laser plasma interaction and attracts great attention due to a wide range of applications. It has been seen that intense electromagnetic and quasi-static transverse magnetic fields are generated in laser plasma interaction. An extremely intense magnetic field (up to hundreds of MG) has been observed by experimental measurements in interaction of short laser pulses with plasma. These self-generated or applied magnetic fields affect the propagation of the laser pulses. In most laser interactions with homogeneous plasma, odd harmonics of laser frequency are generated. In this paper, we point out the possibility of even harmonics generation when a linearly polarized laser beam propagates in homogeneous plasma in the presence of a transverse magnetic field. It is shown that applying external field induces a transverse current density oscillating twice of the laser field which leds to generation of second harmonic radiation. This current density is derived using the perturbation method, and the steady state amplitude of the second harmonic obtained by solution of the wave equation. By the same procedure the current density and then the steady state amplitude of higher order harmonics are calculated. The efficiency of harmonic generation (the ratio of harmonic power to incident power) is a drastically function of the strength of external magnetic field. It is found that the efficiency of even harmonics is zero in the absence of magnetic field and increases as the magnetic field is increased. For odd harmonics, applying the external magnetic field enhances the generated harmonics as well. The conversion efficiency also increases with increase in plasma density and intensity of the laser beam.

A Look at Damped Harmonic Oscillators through the Phase Plane

Science.gov (United States)

Daneshbod, Yousef; Latulippe, Joe

2011-01-01

Damped harmonic oscillations appear naturally in many applications involving mechanical and electrical systems as well as in biological systems. Most students are introduced to harmonic motion in an elementary ordinary differential equation (ODE) course. Solutions to ODEs that describe simple harmonic motion are usually found by investigating the…

Harmonic voltage excess problem test and analysis in UHV and EHV grid particular operation mode

Science.gov (United States)

Lv, Zhenhua; Shi, Mingming; Fei, Juntao

2018-02-01

The test and analysis of the power quality of some 1000kV UHV transmission lines and 500kV EHV transmission lines is carried out. It is found that there is harmonic voltage excess problems when the power supply of the UHV and EHV voltage line is single-ended or single-loop, the problem basically disappeared after the operation mode change, different operating conditions, the harmonic current has not been greatly affected, indicating that the harmonic voltage changes mainly caused by the system harmonic impedance. With the analysis of MATLAB Simulink system model, it can be seen that there are specific harmonic voltage excess in the system under the specific operating mode, which results in serious distortion of the specific harmonic voltage. Since such phenomena are found in 500kV and 1000kV systems, it is suggested that the test evaluation work should be done under the typical mode of operation in 500kV, 1000kV Planning and construction process to prevent the occurrence of serious distortion and the regional harmonic current monitoring and suppression work should be done.

One dimension harmonic oscillator

International Nuclear Information System (INIS)

Cohen-Tannoudji, Claude; Diu, Bernard; Laloe, Franck.

1977-01-01

The importance of harmonic oscillator in classical and quantum physics, eigenvalues and eigenstates of hamiltonian operator are discussed. In complement are presented: study of some physical examples of harmonic oscillators; study of stationnary states in the /x> representation; Hermite polynomials; resolution of eigenvalue equation of harmonic oscillator by polynomial method; isotope harmonic oscillator with three dimensions; charged harmonic oscillator in uniform electric field; quasi classical coherent states of harmonic oscillator; eigenmodes of vibration of two coupled harmonic oscillators; vibration modus of a continuous physical system (application to radiation: photons); vibration modus of indefinite linear chain of coupled harmonic oscillators (phonons); one-dimensional harmonic oscillator in thermodynamic equilibrium at temperature T [fr

Automatic transfer function generation using contour tree controlled residue flow model and color harmonics.

Science.gov (United States)

Zhou, Jianlong; Takatsuka, Masahiro

2009-01-01

Transfer functions facilitate the volumetric data visualization by assigning optical properties to various data features and scalar values. Automation of transfer function specifications still remains a challenge in volume rendering. This paper presents an approach for automating transfer function generations by utilizing topological attributes derived from the contour tree of a volume. The contour tree acts as a visual index to volume segments, and captures associated topological attributes involved in volumetric data. A residue flow model based on Darcy's Law is employed to control distributions of opacity between branches of the contour tree. Topological attributes are also used to control color selection in a perceptual color space and create harmonic color transfer functions. The generated transfer functions can depict inclusion relationship between structures and maximize opacity and color differences between them. The proposed approach allows efficient automation of transfer function generations, and exploration on the data to be carried out based on controlling of opacity residue flow rate instead of complex low-level transfer function parameter adjustments. Experiments on various data sets demonstrate the practical use of our approach in transfer function generations.

Harmonic current prediction by impedance modeling of grid-tied inverters

DEFF Research Database (Denmark)

Pereira, Heverton A.; Freijedo, Francisco D.; Silva, M. M.

2017-01-01

and harmonic voltage profiles. Results reinforce that impedance models can represent with relatively accuracy the harmonic current emitted by the PV plants at the point of common coupling (PCC). Lastly, a stress test is performed to show how a variation in the harmonic voltage phase angle impacts the PV plant...... impedance models when used in harmonic integration studies. It is aimed to estimate the harmonic current contribution as a function of the background harmonic voltages components. Time domain simulations based on detailed and average models are compared with the impedance model developed in frequency domain....... In grids with harmonic voltages, impedance models can predict the current distortion for all active power injection scenarios. Furthermore, measurements in a 1.4 MW PV plant connected in a distributed grid are used to validate the simulation based on impedance models during different power injections...

Electric shock and elevated EMF levels due to triplen harmonics

International Nuclear Information System (INIS)

Tran, T.Q.; Conrad, L.E.; Stallman, B.K.

1996-01-01

The increasing use of single phase rectifiers for electric power conversion in residential applications increases harmonic load on utility systems. Many papers have analyzed the effect of these loads on power quality and equipment loadability. However, there are two more critical concerns for harmonic loads served phase to neutral on multi-grounded wye systems. Triplen harmonics, particularly the third, add in the neutral and have little diversity between loads. The higher neutral currents may cause significant problems. Neutral to earth voltages will increase near the substations which could increase stray voltage complaints. The additional neutral current on three phase lines will elevate EMF levels especially in the fringe areas. This paper provides fundamental understanding of triplen harmonic influence on stray voltage and EMF related to multi-grounded wye electric distribution systems

Correlated kinetic energy density functional of ground states of harmonically confined two-electron atoms for arbitrary interparticle interaction

International Nuclear Information System (INIS)

Amovilli, C; March, N H

2012-01-01

Utilizing the earlier work of Holas et al (2003 Phys. Lett. A 310 451) and the more recent contribution of Akbari et al (2009 Phys. Rev. A 80 032509), we construct an integral equation for the relative motion (RM) contribution t RM (r) to the correlated kinetic energy density for modelling two-electron atoms with harmonic confinement but arbitrary interparticle interaction. It is stressed that t RM = t RM [f(G)], where f(G) is the atomic scattering factor: the Fourier transform of the density ρ(r). As a simple illustrative example of this functional relation for the correlated kinetic energy density, the harmonic Moshinsky case is investigated, the scattering factor then having a Gaussian form. (paper)

HARMONIC DRIVE SELECTION

Directory of Open Access Journals (Sweden)

Piotr FOLĘGA

2014-03-01

Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

Narrowband-to-Narrowband Frequency Reconfiguration with Harmonic Suppression Using Fractal Dipole Antenna

Directory of Open Access Journals (Sweden)

S. A. Hamzah

2013-01-01

Full Text Available Harmonic suppressed fractal antenna with switches named TMFDB25 is developed to select desired frequency band from 400 MHz to 3.5 GHz. The radiating element length is changed to tune the operating frequency while the stub is used to eliminate the undesired harmonic frequency. The balun circuit is reduced by 75% from the original size. The antenna is built on a low loss material. It has the ability to select a single frequency out of fifteen different bands and maintain the omnidirectional radiation pattern properties. Furthermore, the antenna is designed, built, and tested. Simulation and measurement results show that the antenna operates well at the specific frequency range. Therefore, the antenna is suitable to be used for switching frequencies in the band of TV, GSM900/1800, 3G, ISM 2.4 GHz, and above.

Molecular integrals for exponential-type orbitals using hyperspherical harmonics

DEFF Research Database (Denmark)

Avery, James Emil; Avery, John Scales

2015-01-01

-dimensional hypersphere. Using this projection, Fock was able to show that the Fourier transforms of Coulomb Sturmian basis functions are very simply related to four-dimensional hyperspherical harmonics.With the help of Fock's relationships and the theory of hyperspherical harmonics we are able to evaluate molecular...

Infinite-time and finite-time synchronization of coupled harmonic oscillators

International Nuclear Information System (INIS)

Cheng, S; Ji, J C; Zhou, J

2011-01-01

This paper studies the infinite-time and finite-time synchronization of coupled harmonic oscillators with distributed protocol in the scenarios with and without a leader. In the absence of a leader, the convergence conditions and the final trajectories that each harmonic oscillator follows are developed. In the presence of a leader, it is shown that all harmonic oscillators can achieve the trajectory of the leader in finite time. Numerical simulations of six coupled harmonic oscillators are given to show the effects of the interaction function parameter, algebraic connectivity and initial conditions on the convergence time.

A single European pharmaceutical market: Does maximum harmonization enhance medicinal product innovation?

DEFF Research Database (Denmark)

Faeh, Andrea Beata

2013-01-01

the orphan medicinal products scheme. The latter is subject to uniform Union rules specifically introduced to stimulate research and development and has led to the development of a number of new products. The article shows that the most radical positive integration depends to a large extent on the prospect...... – Innovation Union’ – market fragmentation to be one of the major causes of the lack of innovation. In order to establish if maximum harmonization benefits innovation, two distinct legal regimes in the pharmaceutical sector will be compared. The general rules for medicinal products are weighed against...... of it yielding revenue for the innovator. Hence, fuller harmonization can benefit innovation, but it is just as important, if not more important, to address other factors such as pricing, reimbursement and patent protection....

Intense harmonic generation from various ablation media

International Nuclear Information System (INIS)

Ozaki, T.; Elouga, L.; Suzuki, M.; Kuroda, H.; Ganeev, R.A.

2006-01-01

lens (f = 680 nm). The high-order harmonics were spectrally resolved using a flat-field grazing-incidence XUV spectrometer with a Hitachi 1200-grooves/mm grating. The XUV spectrum was detected by a microchannel plate with phosphor screen and recorded by a CCD camera. Ablation harmonic experiments were performed with silver and indium targets. We selected silver because of its high conversion efficiency, and indium for its peculiar intensity enhancement effects of the 13 th harmonics. Due to the high intensities of the ablation harmonics, all harmonic spectra were obtained in a single shot. Experiments reveal that the pre-pulse condition for maximum harmonic generation is distinctly different for the two targets. Hydrodynamic simulations using the HYADES code show that the high density of the ablation medium results in strong absorption of the generated harmonics. Therefore, the trade-off between high harmonic efficiency and high absorption is especially important in the present scheme, which can change significantly with the pre-plasma condition. Results with indium targets also reveal a distinct change in the ratio between the 13 th and 15 th harmonic intensity when varying the main pump intensity. This phenomenon is attributed to the change in the resonance conditions of the 13 th harmonic with a strong radiative transition of the In + ion, due to the AC-Stark effect. We will also present new results on ablation harmonics using tin targets.

Static harmonization of dynamically harmonized Fourier transform ion cyclotron resonance cell.

Science.gov (United States)

Zhdanova, Ekaterina; Kostyukevich, Yury; Nikolaev, Eugene

2017-08-01

Static harmonization in the Fourier transform ion cyclotron resonance cell improves the resolving power of the cell and prevents dephasing of the ion cloud in the case of any trajectory of the charged particle, not necessarily axisymmetric cyclotron (as opposed to dynamic harmonization). We reveal that the Fourier transform ion cyclotron resonance cell with dynamic harmonization (paracell) is proved to be statically harmonized. The volume of the statically harmonized potential distribution increases with an increase in the number of trap segments.

Bi-harmonic cantilever design for improved measurement sensitivity in tapping-mode atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Loganathan, Muthukumaran; Bristow, Douglas A., E-mail: dbristow@mst.edu [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, Missouri 65401 (United States)

2014-04-15

This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant mode at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.

Bi-harmonic cantilever design for improved measurement sensitivity in tapping-mode atomic force microscopy.

Science.gov (United States)

Loganathan, Muthukumaran; Bristow, Douglas A

2014-04-01

This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant mode at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.

Optimization of multi-color laser waveform for high-order harmonic generation

Science.gov (United States)

Jin, Cheng; Lin, C. D.

2016-09-01

With the development of laser technologies, multi-color light-field synthesis with complete amplitude and phase control would make it possible to generate arbitrary optical waveforms. A practical optimization algorithm is needed to generate such a waveform in order to control strong-field processes. We review some recent theoretical works of the optimization of amplitudes and phases of multi-color lasers to modify the single-atom high-order harmonic generation based on genetic algorithm. By choosing different fitness criteria, we demonstrate that: (i) harmonic yields can be enhanced by 10 to 100 times, (ii) harmonic cutoff energy can be substantially extended, (iii) specific harmonic orders can be selectively enhanced, and (iv) single attosecond pulses can be efficiently generated. The possibility of optimizing macroscopic conditions for the improved phase matching and low divergence of high harmonics is also discussed. The waveform control and optimization are expected to be new drivers for the next wave of breakthrough in the strong-field physics in the coming years. Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. 30916011207), Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U. S. Department of Energy (Grant No. DE-FG02-86ER13491), and Air Force Office of Scientific Research, USA (Grant No. FA9550-14-1-0255).

Resonant third harmonic generation of KrF laser in Ar gas

Energy Technology Data Exchange (ETDEWEB)

Rakowski, R. [Department of Experimental Physics, University of Szeged, 6720 Szeged, Dóm tér 9 (Hungary); Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00–908 Warsaw (Poland); Barna, A. [Department of Experimental Physics, University of Szeged, 6720 Szeged, Dóm tér 9 (Hungary); Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, EURATOM Association HAS, 1121 Budapest, XII. Konkoly Thege Miklós út 29-33 (Hungary); Suta, T.; Földes, I. B. [Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, EURATOM Association HAS, 1121 Budapest, XII. Konkoly Thege Miklós út 29-33 (Hungary); Bohus, J.; Szatmári, S. [Department of Experimental Physics, University of Szeged, 6720 Szeged, Dóm tér 9 (Hungary); Mikołajczyk, J.; Bartnik, A.; Fiedorowicz, H. [Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00–908 Warsaw (Poland); Verona, C. [Department of Mechanical Engineering, University “Tor Vergata”, Via Orazio Raimondo, 18–00173, Rome (Italy); Verona Rinati, G. [Department of Industrial Engineering, University “Tor Vergata”, Via Orazio Raimondo, 18–00173, Rome (Italy); Margarone, D. [Institute of Physics ASCR, v.v.i. (FZU), ELI-Beamlines Project, 182 21 Prague (Czech Republic); Nowak, T. [Institute of Nuclear Physics, PAN, E. Radzikowskiego 152, 31–342 Cracow (Poland); and others

2014-12-15

Investigations of emission of harmonics from argon gas jet irradiated by 700 fs, 5 mJ pulses from a KrF laser are presented. Harmonics conversion was optimized by varying the experimental geometry and the nozzle size. For the collection of the harmonic radiation silicon and solar-blind diamond semiconductor detectors equipped with charge preamplifiers were applied. The possibility of using a single-crystal CVD diamond detector for separate measurement of the 3rd harmonic in the presence of a strong pumping radiation was explored. Our experiments show that the earlier suggested 0.7% conversion efficiency can really be obtained, but only in the case when phase matching is optimized with an elongated gas target length corresponding to the length of coherence.

Collective excitations of harmonically trapped ideal gases

NARCIS (Netherlands)

Van Schaeybroeck, B.; Lazarides, A.

2009-01-01

We theoretically study the collective excitations of an ideal gas confined in an isotropic harmonic trap. We give an exact solution to the Boltzmann-Vlasov equation; as expected for a single-component system, the associated mode frequencies are integer multiples of the trapping frequency. We show

Harmonics in large offshore wind farms

DEFF Research Database (Denmark)

Kocewiak, Lukasz Hubert

and nature of various harmonic components. A comprehensive comparison of harmonic voltages and currents based on probability distribution estimation and appropriate statistics calculation (mean, variance, probability density function, etc.) is applied. Such approach gives a better overview and comparison...... and analysis, and ϐinally ending up on modelling and models application. Different aspects of validation in time domain, frequency domain, and by application of statistical methods are mentioned in relation to respective problems. Measurements constitute a core part in industry-oriented research. Due...... that it is of great importance to know the nature of generated harmonics in large offshore wind farms in order to apply the most suitable data processing technique. Time-frequency analysis based on multiresolution wavelet transform is used in order to perform time-frequency domain analysis helpful to distinguish...

Recent progress of below-threshold harmonic generation

International Nuclear Information System (INIS)

Xiong, Wei-Hao; Peng, Liang-You; Gong, Qihuang

2017-01-01

The harmonics generated from the interaction of a strong laser field with atoms and molecules in the gas phase can be applied as coherent light sources and detecting techniques for structures and dynamics in matter. In the last three decades, the most prevailing experimental and theoretical studies have been focused on the high-order harmonic generation due to its applications in attosecond science. However, low-order harmonics near the ionization threshold of the target have been less explored, partially because the spectrum in this region is more complicated from both the theoretical and experimental point of view. After several pioneering investigations in the mid 1990s, near threshold harmonics (NTHs) begun to draw a great attention again because of the development of high repetition rate cavity enhanced harmonics about 10 years ago. Very recently, NTHs have attracted a lot of experimental and theoretical studies due to their potential applications as light sources and complicated mechanisms. In this topical review, we will summarize the progress of NTHs, including the early and recent experimental measurements in atoms and molecules, as well as the relevant theoretical explorations of these harmonics. (topical review)

Influence of time-periodic potentials on electronic transport in double-well structure

International Nuclear Information System (INIS)

Chun-Lei, Li; Yan, Xu

2010-01-01

Within the framework of the Floquet theorem, we have investigated single-electron photon-assisted tunneling in a double-well system using the transfer matrix technique. The transmission probability displays satellite peaks on both sides of the main resonance peaks and these satellite peaks originate from emission or absorption photons. The single-electron resonance tunneling can be controlled through changing the applied harmonically potential positions, such as driven potential in wells, in barriers, or in whole double-well systems. This advantage should be useful in the optimization of the parameters of a transmission device. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Local solutions of harmonical and Bi-harmonical equations, universal field equation and self-dual configurations of Yang-Mills fields in four dimensions

International Nuclear Information System (INIS)

Leznov, A.N.

1994-01-01

A general method for the construction of solutions of the d'Alamberian and double d'Alamberian (harmonic and bi-harmonic) equations with local dependence of arbitrary functions upon two independent arguments is proposed. The connection between solutions of this kind and self-dual configurations of gauge fields having no singularities is established. 5 refs

Phase Memory Preserving Harmonics from Abruptly Autofocusing Beams.

Science.gov (United States)

Koulouklidis, Anastasios D; Papazoglou, Dimitris G; Fedorov, Vladimir Yu; Tzortzakis, Stelios

2017-12-01

We demonstrate both theoretically and experimentally that the harmonics from abruptly autofocusing ring-Airy beams present a surprising property: They preserve the phase distribution of the fundamental beam. Consequently, this "phase memory" imparts to the harmonics the abrupt autofocusing behavior, while, under certain conditions, their foci coincide in space with the one of the fundamental. Experiments agree well with our theoretical estimates and detailed numerical calculations. Our findings open the way for the use of such beams and their harmonics in strong field science.

On-line grid impedance estimation based on harmonic injection for grid-connected PV inverter

DEFF Research Database (Denmark)

Ciobotaru, Mihai; Teodorescu, Remus; Blaabjerg, Frede

2007-01-01

two different signal processing algorithms. The DFT technique is used for the single harmonic injection and the statistic technique is used for the double harmonic injection. The grid impedance estimation is used for compliance with the anti-islanding requirements of the German standard (VDE0126...

Optical Third-Harmonic Generation in Graphene

Directory of Open Access Journals (Sweden)

Sung-Young Hong

2013-06-01

Full Text Available We report strong third-harmonic generation in monolayer graphene grown by chemical vapor deposition and transferred to an amorphous silica (glass substrate; the photon energy is in three-photon resonance with the exciton-shifted van Hove singularity at the M point of graphene. The polarization selection rules are derived and experimentally verified. In addition, our polarization- and azimuthal-rotation-dependent third-harmonic-generation measurements reveal in-plane isotropy as well as anisotropy between the in-plane and out-of-plane nonlinear optical responses of graphene. Since the third-harmonic signal exceeds that from bulk glass by more than 2 orders of magnitude, the signal contrast permits background-free scanning of graphene and provides insight into the structural properties of graphene.

Harmonic-hopping in Wallacea's bats.

Science.gov (United States)

Kingston, Tigga; Rossiter, Stephen J

2004-06-10

Evolutionary divergence between species is facilitated by ecological shifts, and divergence is particularly rapid when such shifts also promote assortative mating. Horseshoe bats are a diverse Old World family (Rhinolophidae) that have undergone a rapid radiation in the past 5 million years. These insectivorous bats use a predominantly pure-tone echolocation call matched to an auditory fovea (an over-representation of the pure-tone frequency in the cochlea and inferior colliculus) to detect the minute changes in echo amplitude and frequency generated when an insect flutters its wings. The emitted signal is the accentuated second harmonic of a series in which the fundamental and remaining harmonics are filtered out. Here we show that three distinct, sympatric size morphs of the large-eared horseshoe bat (Rhinolophus philippinensis) echolocate at different harmonics of the same fundamental frequency. These morphs have undergone recent genetic divergence, and this process has occurred in parallel more than once. We suggest that switching harmonics creates a discontinuity in the bats' perception of available prey that can initiate disruptive selection. Moreover, because call frequency in horseshoe bats has a dual function in resource acquisition and communication, ecological selection on frequency might lead to assortative mating and ultimately reproductive isolation and speciation, regardless of external barriers to gene flow.

Spatial properties of odd and even low order harmonics generated in gas.

Science.gov (United States)

Lambert, G; Andreev, A; Gautier, J; Giannessi, L; Malka, V; Petralia, A; Sebban, S; Stremoukhov, S; Tissandier, F; Vodungbo, B; Zeitoun, Ph

2015-01-14

High harmonic generation in gases is developing rapidly as a soft X-ray femtosecond light-source for applications. This requires control over all the harmonics characteristics and in particular, spatial properties have to be kept very good. In previous literature, measurements have always included several harmonics contrary to applications, especially spectroscopic applications, which usually require a single harmonic. To fill this gap, we present here for the first time a detailed study of completely isolated harmonics. The contribution of the surrounding harmonics has been totally suppressed using interferential filtering which is available for low harmonic orders. In addition, this allows to clearly identify behaviors of standard odd orders from even orders obtained by frequency-mixing of a fundamental laser and of its second harmonic. Comparisons of the spatial intensity profiles, of the spatial coherence and of the wavefront aberration level of 5ω at 160 nm and 6ω at 135 nm have then been performed. We have established that the fundamental laser beam aberrations can cause the appearance of a non-homogenous donut-shape in the 6ω spatial intensity distribution. This undesirable effect can be easily controlled. We finally conclude that the spatial quality of an even harmonic can be as excellent as in standard generation.

Combination of binaural and harmonic masking release effects in the detection of a single component in complex tones.

Science.gov (United States)

Klein-Hennig, Martin; Dietz, Mathias; Hohmann, Volker

2018-03-01

Both harmonic and binaural signal properties are relevant for auditory processing. To investigate how these cues combine in the auditory system, detection thresholds for an 800-Hz tone masked by a diotic (i.e., identical between the ears) harmonic complex tone were measured in six normal-hearing subjects. The target tone was presented either diotically or with an interaural phase difference (IPD) of 180° and in either harmonic or "mistuned" relationship to the diotic masker. Three different maskers were used, a resolved and an unresolved complex tone (fundamental frequency: 160 and 40 Hz) with four components below and above the target frequency and a broadband unresolved complex tone with 12 additional components. The target IPD provided release from masking in most masker conditions, whereas mistuning led to a significant release from masking only in the diotic conditions with the resolved and the narrowband unresolved maskers. A significant effect of mistuning was neither found in the diotic condition with the wideband unresolved masker nor in any of the dichotic conditions. An auditory model with a single analysis frequency band and different binaural processing schemes was employed to predict the data of the unresolved masker conditions. Sensitivity to modulation cues was achieved by including an auditory-motivated modulation filter in the processing pathway. The predictions of the diotic data were in line with the experimental results and literature data in the narrowband condition, but not in the broadband condition, suggesting that across-frequency processing is involved in processing modulation information. The experimental and model results in the dichotic conditions show that the binaural processor cannot exploit modulation information in binaurally unmasked conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Neck dissection with harmonic scalpel and electrocautery? A randomised study.

Science.gov (United States)

Verma, Roshan K; Mathiazhagan, Arulalan; Panda, Naresh K

2017-10-01

Is the use of harmonic scalpel for neck dissection useful? Literature search did not show a single, prospective, randomised control trial. We intended to study the role of harmonic scalpel in neck dissection and compare it with conventional electrocautery technique for oral cavity carcinoma. 40 patients undergoing selective neck dissection for primary oral cavity malignancy were enrolled in this study. The harmonic scalpel (HS) group consisted of 20 patients, and the electrocautery technique (ET) group comprised of 20 patients. The following variables were examined: intraoperative blood loss, operative time, number of ligatures used, postoperative drain, and postoperative hospital stay. Intraoperative blood loss was found to be significantly reduced in harmonic scalpel group as compared to electrocautery group. However, we found no difference in other parameters like operative time, postop drain, postoperative hospital stay and number of ligatures used between both groups. Harmonic scalpel for neck dissection is associated with significantly lesser intraoperative blood loss as compared to electrocautery. There is no effect on operative time and postoperative hospital stay in both groups. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Mixed biexcitons in single quantum wells

DEFF Research Database (Denmark)

Wagner, Hans Peter; Langbein, Wolfgang Werner; Hvam, Jørn Märcher

1999-01-01

Biexcitonic complexes in a ZnSe single quantum well are investigated by spectrally resolved four-wave mixing (FWM). The formation of heavy-heavy-hole XXh and of mixed heavy-light-hole XXm biexcitons showing binding energies of Delta(h) = 4.8 meV and Delta(m)= 2.8 meV is identified by polarization...

Quantization with maximally degenerate Poisson brackets: the harmonic oscillator!

International Nuclear Information System (INIS)

Nutku, Yavuz

2003-01-01

Nambu's construction of multi-linear brackets for super-integrable systems can be thought of as degenerate Poisson brackets with a maximal set of Casimirs in their kernel. By introducing privileged coordinates in phase space these degenerate Poisson brackets are brought to the form of Heisenberg's equations. We propose a definition for constructing quantum operators for classical functions, which enables us to turn the maximally degenerate Poisson brackets into operators. They pose a set of eigenvalue problems for a new state vector. The requirement of the single-valuedness of this eigenfunction leads to quantization. The example of the harmonic oscillator is used to illustrate this general procedure for quantizing a class of maximally super-integrable systems

Harmonic analysis and suppression in hybrid wind & PV solar system

Science.gov (United States)

Gupta, Tripti; Namekar, Swapnil

2018-04-01

The growing demand of electricity has led to produce power through non-conventional source of energy such as solar energy, wind energy, hydro power, energy through biogas and biomass etc. Hybrid system is taken to complement the shortcoming of either sources of energy. The proposed system is grid connected hybrid wind and solar system. A 2.1 MW Doubly fed Induction Generator (DFIG) has been taken for analysis of wind farm whose rotor part is connected to two back-to-back converters. A 250 KW Photovoltaic (PV) array taken to analyze solar farm where inverter is required to convert power from DC to AC since electricity generated through solar PV is in the form of DC. Stability and reliability of the system is very important when the system is grid connected. Harmonics is the major Power quality issue which degrades the quality of power at load side. Harmonics in hybrid system arise through the use of power conversion unit. The other causes of harmonics are fluctuation in wind speed and solar irradiance. The power delivered to grid must be free from harmonics and within the limits specified by Indian grid codes. In proposed work, harmonic analysis of the hybrid system is performed in Electrical Transient Analysis program (ETAP) and single tuned harmonic filter is designed to maintain the utility grid harmonics within limits.

High-Harmonic Generation in Solids with and without Topological Edge States

DEFF Research Database (Denmark)

Bauer, Dieter; Hansen, Kenneth Christian Klochmann

2018-01-01

High-harmonic generation in the two topological phases of a finite, one-dimensional, periodic structure is investigated using a self-consistent time-dependent density functional theory approach. For harmonic photon energies smaller than the band gap, the harmonic yield is found to differ by up...... to 14 orders of magnitude for the two topological phases. This giant topological effect is explained by the degree of destructive interference in the harmonic emission of all valence-band (and edge-state) electrons, which strongly depends on whether or not topological edge states are present...

Practical Considerations Concerning the Interleaved Transition Mode Single-stage Ballast

DEFF Research Database (Denmark)

Teodorescu, Remus; Kjær, Søren Bækhøj; Munk-Nielsen, Stig

2002-01-01

The aim of this paper is to present a novel single-stage interleaved ballast focusing on practical design aspects like: key current expression, overall losses, harmonic analysis of the differential-mode EMI current and preheating ballast function. A new preheating method is also presented. A PSPICE...

Deterministic and Stochastic Study of Wind Farm Harmonic Currents

DEFF Research Database (Denmark)

Sainz, Luis; Mesas, Juan Jose; Teodorescu, Remus

2010-01-01

Wind farm harmonic emissions are a well-known power quality problem, but little data based on actual wind farm measurements are available in literature. In this paper, harmonic emissions of an 18 MW wind farm are investigated using extensive measurements, and the deterministic and stochastic char...

New Evidence That Nonlinear Source-Filter Coupling Affects Harmonic Intensity and fo Stability During Instances of Harmonics Crossing Formants.

Science.gov (United States)

Maxfield, Lynn; Palaparthi, Anil; Titze, Ingo

2017-03-01

The traditional source-filter theory of voice production describes a linear relationship between the source (glottal flow pulse) and the filter (vocal tract). Such a linear relationship does not allow for nor explain how changes in the filter may impact the stability and regularity of the source. The objective of this experiment was to examine what effect unpredictable changes to vocal tract dimensions could have on fo stability and individual harmonic intensities in situations in which low frequency harmonics cross formants in a fundamental frequency glide. To determine these effects, eight human subjects (five male, three female) were recorded producing fo glides while their vocal tracts were artificially lengthened by a section of vinyl tubing inserted into the mouth. It was hypothesized that if the source and filter operated as a purely linear system, harmonic intensities would increase and decrease at nearly the same rates as they passed through a formant bandwidth, resulting in a relatively symmetric peak on an intensity-time contour. Additionally, fo stability should not be predictably perturbed by formant/harmonic crossings in a linear system. Acoustic analysis of these recordings, however, revealed that harmonic intensity peaks were asymmetric in 76% of cases, and that 85% of fo instabilities aligned with a crossing of one of the first four harmonics with the first three formants. These results provide further evidence that nonlinear dynamics in the source-filter relationship can impact fo stability as well as harmonic intensities as harmonics cross through formant bandwidths. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Global Harmonic Current Rejection of Nonlinear Backstepping Control with Multivariable Adaptive Internal Model Principle for Grid-Connected Inverter under Distorted Grid Voltage

Directory of Open Access Journals (Sweden)

Yang Yu

2013-01-01

Full Text Available Based on a brief review on current harmonics generation mechanism for grid-connected inverter under distorted grid voltage, the harmonic disturbances and uncertain items are immersed into the original state-space differential equation of grid-connected inverter. A new algorithm of global current harmonic rejection based on nonlinear backstepping control with multivariable internal model principle is proposed for grid-connected inverter with exogenous disturbances and uncertainties. A type of multivariable internal model for a class of nonlinear harmonic disturbances is constructed. Based on application of backstepping control law of the nominal system, a multivariable adaptive state feedback controller combined with multivariable internal model and adaptive control law is designed to guarantee the closed-loop system globally uniformly bounded, which is proved by a constructed Lyapunov function. The presented algorithm extends rejection of nonlinear single-input systems to multivariable globally defined normal form, the correctness and effectiveness of which are verified by the simulation results.

Harmonics analysis of the photonic time stretch system.

Science.gov (United States)

Mei, Yuan; Xu, Boyu; Chi, Hao; Jin, Tao; Zheng, Shilie; Jin, Xiaofeng; Zhang, Xianmin

2016-09-10

Photonic time stretch (PTS) has been intensively investigated in recent decades due to its potential application to ultra-wideband analog-to-digital conversion. A high-speed analog signal can be captured by an electronic analog-to-digital converter (ADC) with the help of the PTS technique, which slows down the speed of signal in the photonic domain. Unfortunately, the process of the time stretch is not linear due to the nonlinear modulation of the electro-optic intensity modulator in the PTS system, which means the undesired harmonics distortion. In this paper, we present an exact analytical model to fully characterize the harmonics generation in the PTS systems for the first time, to the best of our knowledge. We obtain concise and closed-form expressions for all harmonics of the PTS system with either a single-arm Mach-Zehnder modulator (MZM) or a push-pull MZM. The presented model can largely simplify the PTS system design and the system parameters estimation, such as system bandwidth, harmonics power, time-bandwidth product, and dynamic range. The correctness of the mathematic model is verified by the numerical and experimental results.

Novel low harmonics 3-phase rectifiers for efficient motor systems; Novel low harmonics 3-phase rectifiers for efficient motor systems. Konzeptstudie - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Pietkiewicz, A.; Melly, S.; Tucker, A.; Haeberle, N. [Schaffner EMV AG, Luterbach (Switzerland); Biner, H.-P. [Haute Ecole Specialisee de Suisse occidentale, HES-SO Valais, Sion (Switzerland)

2010-07-15

This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a concept study made concerning novel low harmonics 3-phase rectifiers for efficient motor systems. The harmonic distortions which are produced by these systems are discussed and ways of minimising them are examined. The authors discuss novel, passive, multi-pulse current splitters that are considered to be cost efficient, compact and highly-reliable harmonics mitigation concepts for three-phase loads. According to the authors, functional prototypes for a nominal load of 4 kW proved, in laboratory tests, the outstanding properties of multi-pulse current splitters with respect to harmonics cancellation and robustness against voltage asymmetry. The design process, prototype construction and application tests are discussed, as are energy-saving potentials and marketing aspects.

An alternative factorization of the quantum harmonic oscillator and two-parameter family of self-adjoint operators

International Nuclear Information System (INIS)

Arcos-Olalla, Rafael; Reyes, Marco A.; Rosu, Haret C.

2012-01-01

We introduce an alternative factorization of the Hamiltonian of the quantum harmonic oscillator which leads to a two-parameter self-adjoint operator from which the standard harmonic oscillator, the one-parameter oscillators introduced by Mielnik, and the Hermite operator are obtained in certain limits of the parameters. In addition, a single Bernoulli-type parameter factorization, which is different from the one introduced by M.A. Reyes, H.C. Rosu, and M.R. Gutiérrez [Phys. Lett. A 375 (2011) 2145], is briefly discussed in the final part of this work. -- Highlights: ► Factorizations with operators which are not mutually adjoint are presented. ► New two-parameter and one-parameter self-adjoint oscillator operators are introduced. ► Their eigenfunctions are two- and one-parameter deformed Hermite functions.

An alternative factorization of the quantum harmonic oscillator and two-parameter family of self-adjoint operators

Energy Technology Data Exchange (ETDEWEB)

Arcos-Olalla, Rafael, E-mail: olalla@fisica.ugto.mx [Departamento de Física, DCI Campus León, Universidad de Guanajuato, Apdo. Postal E143, 37150 León, Gto. (Mexico); Reyes, Marco A., E-mail: marco@fisica.ugto.mx [Departamento de Física, DCI Campus León, Universidad de Guanajuato, Apdo. Postal E143, 37150 León, Gto. (Mexico); Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosí, S.L.P. (Mexico)

2012-10-01

We introduce an alternative factorization of the Hamiltonian of the quantum harmonic oscillator which leads to a two-parameter self-adjoint operator from which the standard harmonic oscillator, the one-parameter oscillators introduced by Mielnik, and the Hermite operator are obtained in certain limits of the parameters. In addition, a single Bernoulli-type parameter factorization, which is different from the one introduced by M.A. Reyes, H.C. Rosu, and M.R. Gutiérrez [Phys. Lett. A 375 (2011) 2145], is briefly discussed in the final part of this work. -- Highlights: ► Factorizations with operators which are not mutually adjoint are presented. ► New two-parameter and one-parameter self-adjoint oscillator operators are introduced. ► Their eigenfunctions are two- and one-parameter deformed Hermite functions.

Exact quantum solution for some symmetrical two-well potentials

International Nuclear Information System (INIS)

Ley-Koo, E.

1985-01-01

We construct the solutions of the Schroedinger equation for the rectangular-well, harmonic-oscillator and symmetric-linear potentials with a delta-function potential superimposed in their central positions. The odd-parity states are not affected by the presence of the delta-function potential. The even-parity states are determined by the condition that their wave functions have in the central position a fixed logarithmic derivative, which is proportional to the intensity the delta-function potential. (author)

Wigner distribution function and entropy of the damped harmonic oscillator within the theory of the open quantum systems

Science.gov (United States)

Isar, Aurelian

1995-01-01

The harmonic oscillator with dissipation is studied within the framework of the Lindblad theory for open quantum systems. By using the Wang-Uhlenbeck method, the Fokker-Planck equation, obtained from the master equation for the density operator, is solved for the Wigner distribution function, subject to either the Gaussian type or the delta-function type of initial conditions. The obtained Wigner functions are two-dimensional Gaussians with different widths. Then a closed expression for the density operator is extracted. The entropy of the system is subsequently calculated and its temporal behavior shows that this quantity relaxes to its equilibrium value.

Search for harmonic emission in solar type I radio bursts

Energy Technology Data Exchange (ETDEWEB)

Jaeggi, M.; Benz, A.O.

1982-03-01

We have made a statistical analysis of the harmonic emission of type I bursts, based upon the latest plasma wave theories for the emission mechanism. No systematic harmonic emission is found within the detection limit. This is also the case for a superposed epoch analysis of many bursts. The derived upper limit of the Langmuir wave energy density is Wsub(L)<5 10/sup -7/.lsub(km)/sup -1/ erg cm/sup -3/, where lsub(km) is the depth of the source. In a few single cases there is emission at the harmonic frequency but we could not exclude that this are change hits of an independent activity present at that frequency. These observations provide a considerable constraint on plasma emission models of type I bursts.

Investigation of an Ultrafast Harmonic Resonant RF Kicker

Energy Technology Data Exchange (ETDEWEB)

Huang, Yulu [Univ. of Chinese Academy of Sciences (CAS), Beijing (China)

2016-10-01

square pulse, and get a Flat-Top waveform which will give a uniform kick over the bunch length of the kicked electron bunches, thus the transverse emittance of these kicked electron bunches can be maintained. By using two identical kickers with the betatron phase advance of 180 degree or its odd multiples, the residual kick voltage wave slopes at the unkicked bunch position will be totally cancelled out. Flat-Top waveform combined with two kicker scheme, the transverse emittance of the cooling electron bunches will be conserved during the whole injection, recirculation, and ejection processes. In the cavity design part, firstly, the cavity geometry is optimized to get high transverse shunt impedance thus less than 100 W of RF losses on the cavity wall can be achieved for all these 10 harmonic modes. To support all these 10 harmonic modes, group of four QWRs are adopted with the mode distribution of 5:3:1:1. In the multi-frequency cavities such as the five-mode-cavity and the three-mode-cavity, tunings are required to achieve the design frequencies for each mode. Slight segments of taper design on the inner conductor help to get the frequencies to be exactly on the odd harmonic modes. Stub tuners equal to the number of resonant modes are inserted to the outer conductor wall to compensate the frequency shifts due manufacturing errors and other perturbations during the operation such as the change of the cavity temperature. Single loop couple is designed for all harmonic modes in each cavity. By adjusting its loop size, position and rotation, it is possible to get the fundamental mode critical coupled and other higher harmonic modes slightly over coupled. A broadband circulator will be considered for absorbing the reflected power. Finally in this part, multipole field components due to the asymmetric cylindrical structure around the beam axis of the cavity as well as the beam-induced higher order mode (HOM) issues will be analyzed and discussed in this thesis. A half

Harmonics and energy management

International Nuclear Information System (INIS)

Andresen, M.

1993-01-01

To summarize what this paper has presented: Voltage and current non-sinusoidal wave shapes exist in our power system. These harmonics result from the prolific use of non-linear loads. The use of these types of loads is increasing dramatically, partly due to the push to implement energy management techniques involving harmonic generating equipment. Harmonic analysis can identify specific harmonics, their frequency, magnitude, and phase shift referenced to the fundamental. Harmonic distortion forces the use of true RMS multimeters for measurement accuracy. High levels of neutral current and N-G voltages are now possible. Transformers may overheat and fail even though they are below rated capacity. Low power factors due to harmonics cannot be corrected by the installation of capacitors, and knowledge of the fundamental VARs or the displacement power factor is needed to use capacitors alone for power factor correction. The harmonic related problems presented are by no means an exhaustive list. Many other concerns arise when harmonics are involved in the power system. The critical issue behind these problems is that many of the devices being recommended from an energy management point of view are contributing to the harmonic levels, and thus to the potential for harmonic problems. We can no longer live in the sinusoidal mentality if we are to be effective in saving energy and reducing costs

The control of electron quantum trajectories on the high-order harmonic generation of CO and N2 molecules in the presence of a low frequency field.

Science.gov (United States)

Koushki, A M; Sadighi-Bonabi, R; Mohsen-Nia, M; Irani, E

2018-04-14

In the present work, an efficient method is theoretically investigated for extending high-order harmonics and ultrashort attosecond pulse generation in N 2 and CO molecules by using the time-dependent density functional theory approach. Our results show that by utilizing chirped laser field in the presence of a low frequency field, not only is the harmonic cutoff extended remarkably but also the single short quantum trajectory is selected to contribute to the harmonic spectra. When a low frequency field is added to the two-color chirped laser field, the long quantum trajectories are suppressed and only the short quantum trajectories contribute to the higher harmonic emission mechanism. As a result, the spectral modulation is significantly decreased and an intense ultrashort pulse can be generated from the supercontinuum region of high harmonics. With such a scheme, the isolated ultrashort attosecond pulses can be generated in length, velocity, and acceleration gauges. Furthermore, these results are explained by using the classical and quantum time-frequency analyses.

High order harmonic generation in rare gases

Energy Technology Data Exchange (ETDEWEB)

Budil, Kimberly Susan [Univ. of California, Davis, CA (United States)

1994-05-01

The process of high order harmonic generation in atomic gases has shown great promise as a method of generating extremely short wavelength radiation, extending far into the extreme ultraviolet (XUV). The process is conceptually simple. A very intense laser pulse (I ~10¹³-10¹⁴ W/cm²) is focused into a dense (~10¹⁷ particles/cm³) atomic medium, causing the atoms to become polarized. These atomic dipoles are then coherently driven by the laser field and begin to radiate at odd harmonics of the laser field. This dissertation is a study of both the physical mechanism of harmonic generation as well as its development as a source of coherent XUV radiation. Recently, a semiclassical theory has been proposed which provides a simple, intuitive description of harmonic generation. In this picture the process is treated in two steps. The atom ionizes via tunneling after which its classical motion in the laser field is studied. Electron trajectories which return to the vicinity of the nucleus may recombine and emit a harmonic photon, while those which do not return will ionize. An experiment was performed to test the validity of this model wherein the trajectory of the electron as it orbits the nucleus or ion core is perturbed by driving the process with elliptically, rather than linearly, polarized laser radiation. The semiclassical theory predicts a rapid turn-off of harmonic production as the ellipticity of the driving field is increased. This decrease in harmonic production is observed experimentally and a simple quantum mechanical theory is used to model the data. The second major focus of this work was on development of the harmonic "source". A series of experiments were performed examining the spatial profiles of the harmonics. The quality of the spatial profile is crucial if the harmonics are to be used as the source for experiments, particularly if they must be refocused.

A Voltage Feedback Based Harmonic Compensation Strategy for Current-Controlled Converters

DEFF Research Database (Denmark)

Zhao, Xin; Meng, Lexuan; Xie, Chuan

2018-01-01

Harmonics have been considered as one of the major issues in future power grids. With the increasing demand in advanced control functions, power electronic converter interfaced distributed generators (DGs) are expected to perform harmonic compensation when necessary. It has been demonstrated in a...

Hyperspherical Harmonics Expansion on Lagrange Meshes for Bosonic Systems in One Dimension

International Nuclear Information System (INIS)

Timofeyuk, N. K.; Baye, D.

2017-01-01

A one-dimensional system of bosons interacting with contact and single-Gaussian forces is studied with an expansion in hyperspherical harmonics. The hyper radial potentials are calculated using the link between the hyperspherical harmonics and the single-particle harmonic-oscillator basis while the coupled hyper radial equations are solved with the Lagrange-mesh method. Extensions of this method are proposed to achieve good convergence with small numbers of mesh points for any truncation of hyper momentum. The convergence with hyper momentum strongly depends on the range of the two-body forces: it is very good for large ranges but deteriorates as the range decreases, being the worst for the contact interaction. In all cases, the lowest-order energy is within 4.5% of the exact solution and shows the correct cubic asymptotic behaviour at large boson numbers. Details of the convergence studies are presented for 3, 5, 20 and 100 bosons. A special treatment for three bosons was found to be necessary. For single-Gaussian interactions, the convergence rate improves with increasing boson number, similar to what happens in the case of three-dimensional systems of bosons. (author)

Density functional theory investigation of two-dimensional dipolar fermions in a harmonic trap

International Nuclear Information System (INIS)

Ustunel, Hande; Abedinpour, Saeed H; Tanatar, B

2014-01-01

We investigate the behavior of polarized dipolar fermions in a two-dimensional harmonic trap in the framework of the density functional theory (DFT) formalism using the local density approximation. We treat only a few particles interacting moderately. Important results were deduced concerning key characteristics of the system such as total energy and particle density. Our results indicate that, at variance with Coulombic systems, the exchange- correlation component was found to provide a large contribution to the total energy for a large range of interaction strengths and particle numbers. In addition, the density profiles of the dipoles are shown to display important features around the origin that is not possible to capture by earlier, simpler treatments of such systems

Preattentive cortical-evoked responses to pure tones, harmonic tones, and speech: influence of music training.

Science.gov (United States)

Nikjeh, Dee A; Lister, Jennifer J; Frisch, Stefan A

2009-08-01

presented as a standard and a deviant in separate blocks. P1-N1-P2 was elicited before each oddball task by presenting each auditory stimulus alone in single blocks. All cortical auditory evoked potentials were recorded in a passive listening condition. Incidental findings revealed that musicians had longer P1 latencies for pure tones and smaller P1 amplitudes for harmonic tones than nonmusicians. There were no P1 group differences for speech stimuli. Musicians compared with nonmusicians had shorter MMN latencies for all deviances (harmonic tones, pure tones, and speech). Musicians had shorter P3a latencies to harmonic tones and speech but not to pure tones. MMN and P3a amplitude were modulated by deviant frequency but not by group membership. Formally trained musicians compared with nonmusicians showed more efficient neural detection of pure tones and harmonic tones; demonstrated superior auditory sensory-memory traces for acoustic features of pure tones, harmonic tones, and speech; and revealed enhanced sensitivity to acoustic changes of spectrally rich stimuli (i.e., harmonic tones and speech). Findings support a general influence of music training on central auditory function and illustrate experience-facilitated modulation of the auditory neural system.

Functional design criteria for the self-installing liquid observation well. Revision 2

International Nuclear Information System (INIS)

Parra, S.A.

1995-01-01

This document presents the functional design criteria for installing liquid observation wells (LOWs) into single-shell tanks containing ferrocyanide or organic wastes. The LOWs will be designed to accommodate the deployment of gamma, neutron, and electromagnetic induction probes and to interface with the existing tank structure and environment

Exact solution of a quantum forced time-dependent harmonic oscillator

Science.gov (United States)

Yeon, Kyu Hwang; George, Thomas F.; Um, Chung IN

1992-01-01

The Schrodinger equation is used to exactly evaluate the propagator, wave function, energy expectation values, uncertainty values, and coherent state for a harmonic oscillator with a time dependent frequency and an external driving time dependent force. These quantities represent the solution of the classical equation of motion for the time dependent harmonic oscillator.

Quantum infinite square well with an oscillating wall

International Nuclear Information System (INIS)

Glasser, M.L.; Mateo, J.; Negro, J.; Nieto, L.M.

2009-01-01

A linear matrix equation is considered for determining the time dependent wave function for a particle in a one-dimensional infinite square well having one moving wall. By a truncation approximation, whose validity is checked in the exactly solvable case of a linearly contracting wall, we examine the cases of a simple harmonically oscillating wall and a non-harmonically oscillating wall for which the defining parameters can be varied. For the latter case, we examine in closer detail the dependence on the frequency changes, and we find three regimes: an adiabatic behabiour for low frequencies, a periodic one for high frequencies, and a chaotic behaviour for an intermediate range of frequencies.

Sub-harmonic bunching with the AGOR cyclotron

NARCIS (Netherlands)

Brandenburg, S; Roobol, LP; Stokroos, M; Marti, F

2001-01-01

A quasi-single gap buncher with saw-tooth voltage has been designed and is currently being built at the KVI. It operates at a sub-harmonic of the RF frequency and has a duty cycle of 80% at 15 MHz. We report on the design of the new buncher, and on results of tests with our sinusoidal buncher to

EANM/EARL harmonization strategies in PET quantification: from daily practice to multicentre oncological studies

Energy Technology Data Exchange (ETDEWEB)

Aide, Nicolas [University Hospital, Nuclear Medicine Department, Caen (France); Caen University, Inserm U1086 ANTICIPE, Caen (France); Lasnon, Charline [Caen University, Inserm U1086 ANTICIPE, Caen (France); Francois Baclesse Cancer Centre, Nuclear Medicine Department, Caen (France); Veit-Haibach, Patrick [University Hospital Zurich, Department of Nuclear Medicine and Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); University Health Network, University of Toronto, Joint Department Medical Imaging, Toronto (Canada); Sera, Terez [University of Szeged, Nuclear Medicine Department, Szeged (Hungary); Sattler, Bernhard [University Hospital of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Boellaard, Ronald [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands)

2017-08-15

Quantitative positron emission tomography/computed tomography (PET/CT) can be used as diagnostic or prognostic tools (i.e. single measurement) or for therapy monitoring (i.e. longitudinal studies) in multicentre studies. Use of quantitative parameters, such as standardized uptake values (SUVs), metabolic active tumor volumes (MATVs) or total lesion glycolysis (TLG), in a multicenter setting requires that these parameters be comparable among patients and sites, regardless of the PET/CT system used. This review describes the motivations and the methodologies for quantitative PET/CT performance harmonization with emphasis on the EANM Research Ltd. (EARL) Fluorodeoxyglucose (FDG) PET/CT accreditation program, one of the international harmonization programs aiming at using FDG PET as a quantitative imaging biomarker. In addition, future accreditation initiatives will be discussed. The validation of the EARL accreditation program to harmonize SUVs and MATVs is described in a wide range of tumor types, with focus on therapy assessment using either the European Organization for Research and Treatment of Cancer (EORTC) criteria or PET Evaluation Response Criteria in Solid Tumors (PERCIST), as well as liver-based scales such as the Deauville score. Finally, also presented in this paper are the results from a survey across 51 EARL-accredited centers reporting how the program was implemented and its impact on daily routine and in clinical trials, harmonization of new metrics such as MATV and heterogeneity features. (orig.)

Challenges and Opportunities for Harmonizing Research Methodology: Raw Accelerometry.

Science.gov (United States)

van Hees, Vincent T; Thaler-Kall, Kathrin; Wolf, Klaus-Hendrik; Brønd, Jan C; Bonomi, Alberto; Schulze, Mareike; Vigl, Matthäus; Morseth, Bente; Hopstock, Laila Arnesdatter; Gorzelniak, Lukas; Schulz, Holger; Brage, Søren; Horsch, Alexander

2016-12-07

Raw accelerometry is increasingly being used in physical activity research, but diversity in sensor design, attachment and signal processing challenges the comparability of research results. Therefore, efforts are needed to harmonize the methodology. In this article we reflect on how increased methodological harmonization may be achieved. The authors of this work convened for a two-day workshop (March 2014) themed on methodological harmonization of raw accelerometry. The discussions at the workshop were used as a basis for this review. Key stakeholders were identified as manufacturers, method developers, method users (application), publishers, and funders. To facilitate methodological harmonization in raw accelerometry the following action points were proposed: i) Manufacturers are encouraged to provide a detailed specification of their sensors, ii) Each fundamental step of algorithms for processing raw accelerometer data should be documented, and ideally also motivated, to facilitate interpretation and discussion, iii) Algorithm developers and method users should be open about uncertainties in the description of data and the uncertainty of the inference itself, iv) All new algorithms which are pitched as "ready for implementation" should be shared with the community to facilitate replication and ongoing evaluation by independent groups, and v) A dynamic interaction between method stakeholders should be encouraged to facilitate a well-informed harmonization process. The workshop led to the identification of a number of opportunities for harmonizing methodological practice. The discussion as well as the practical checklists proposed in this review should provide guidance for stakeholders on how to contribute to increased harmonization.

Mapping from rectangular to harmonic representation

International Nuclear Information System (INIS)

Schneider, W.; Bateman, G.

1986-08-01

An algorithm is developed to determine the Fourier harmonics representing the level contours of a scalar function given on a rectangular grid. This method is applied to the problem of computing the flux coordinates and flux surface average needed for 1-1/2-D transport codes and MHD stability codes from an equilibrium flux function given on a rectangular grid

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

DEFF Research Database (Denmark)

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

2015-01-01

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

Analytical Expressions for Harmonic Distortion at Low Frequencies due to Device Mismatch in CMOS Current Mirrors

DEFF Research Database (Denmark)

Bruun, Erik

1999-01-01

One of the origins of harmonic distortion in current mirrors is the inevitable mismatch between the mirror transistors. In this brief we examine both single current mirrors and complementary class AB current mirrors and develop analytical expressions for the mismatch induced harmonic distortion. ...

Harmonic analysis

CERN Document Server

Helson, Henry

2010-01-01

This second edition has been enlarged and considerably rewritten. Among the new topics are infinite product spaces with applications to probability, disintegration of measures on product spaces, positive definite functions on the line, and additional information about Weyl's theorems on equidistribution. Topics that have continued from the first edition include Minkowski's theorem, measures with bounded powers, idempotent measures, spectral sets of bounded functions and a theorem of Szego, and the Wiener Tauberian theorem. Readers of the book should have studied the Lebesgue integral, the elementary theory of analytic and harmonic functions, and the basic theory of Banach spaces. The treatment is classical and as simple as possible. This is an instructional book, not a treatise. Mathematics students interested in analysis will find here what they need to know about Fourier analysis. Physicists and others can use the book as a reference for more advanced topics.

Magnetic field induced third order susceptibility of third order harmonic generation in a ZnMgSe strained quantum well

Energy Technology Data Exchange (ETDEWEB)

Mark, J. Abraham Hudson, E-mail: a.john.peter@gmail.com; Peter, A. John, E-mail: a.john.peter@gmail.com [Dept. of Physics, SSM Institute of Engineering and Technology, Dindigul-624002 (India)

2014-04-24

Third order susceptibility of third order harmonic generation is investigated in a Zn{sub 0.1}Mg{sub 0.9}Se/Zn{sub 0.8}Mg{sub 0.2}Se/Zn{sub 0.1}Mg{sub 0.9}Se quantum well in the presence of magnetic field strength. The confinement potential is considered as the addition of energy offsets of the conduction band (or valence band) and the strain-induced potential in our calculations. The material dependent effective mass is followed throughout the computation because it has a high influence on the electron energy levels in low dimensional semiconductor systems.

Nonlinearly driven harmonics of Alfvén modes

Science.gov (United States)

Zhang, B.; Breizman, B. N.; Zheng, L. J.; Berk, H. L.

2014-01-01

In order to study the leading order nonlinear magneto-hydrodynamic (MHD) harmonic response of a plasma in realistic geometry, the AEGIS code has been generalized to account for inhomogeneous source terms. These source terms are expressed in terms of the quadratic corrections that depend on the functional form of a linear MHD eigenmode, such as the Toroidal Alfvén Eigenmode. The solution of the resultant equation gives the second order harmonic response. Preliminary results are presented here.

Nonlinearly driven harmonics of Alfvén modes

Energy Technology Data Exchange (ETDEWEB)

Zhang, B., E-mail: bozhang@austin.utexas.edu; Breizman, B. N.; Zheng, L. J.; Berk, H. L. [Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)

2014-01-15

In order to study the leading order nonlinear magneto-hydrodynamic (MHD) harmonic response of a plasma in realistic geometry, the AEGIS code has been generalized to account for inhomogeneous source terms. These source terms are expressed in terms of the quadratic corrections that depend on the functional form of a linear MHD eigenmode, such as the Toroidal Alfvén Eigenmode. The solution of the resultant equation gives the second order harmonic response. Preliminary results are presented here.

Bismuth-, Tin-, and Lead-Containing Metal-Organic Materials: Synthesis, Structure, Photoluminescence, Second Harmonic Generation, and Ferroelectric Properties

Science.gov (United States)

Wibowo, Arief Cahyo

Metal-Organic Materials (MOMs) contain metal moieties and organic ligands that combine to form discrete (e.g. metal-organic polyhedra, spheres or nanoballs, metal-organic polygons) or polymeric structures with one-, two-, or three-dimensional periodicities that can exhibit a variety of properties resulting from the presence of the metal moieties and/or ligand connectors in the structure. To date, MOMs with a range of functional attributes have been prepared, including record-breaking porosity, catalytic properties, molecular magnetism, chemical separations and sensing ability, luminescence and NLO properties, multiferroic, ferroelectric, and switchable molecular dielectric properties. We are interested in synthesizing non-centrosymmetric MOM single crystals possessing one of the ten polar space groups required for non-linear optical properties (such as second harmonic generation) and ferroelectric applications. This thesis is divided into two main parts: materials with optical properties, such as photoluminescence and materials for targeted applications such as second harmonic generation and ferroelectric properties. This thesis starts with an introduction describing material having centrosymmetric, non-polar space groups, single crystals structures and their photoluminescence properties. These crystals exhibit very interesting and rare structures as well as interesting photoluminescence properties. Chapters 2-5 of this thesis focus on photoluminescent properties of new MOMs, and detail the exploratory research involving the comparatively rare bismuth, lead, and tin coordination polymers. Specifically, the formation of single white-light emitting phosphors based on the combination of bismuth or lead with pyridine-2,5-dicarboxylate is discussed (Chapter 2). The observation of a new Bi2O2 layer and a new Bi4O 3 chain in bismuth terephthalate-based coordination polymers is presented in Chapter 3, while the formation of diverse structures of tin-based coordination

Control of electron localization to isolate and enhance molecular harmonic plateau in asymmetric HeH2+ system

International Nuclear Information System (INIS)

Lu, Ruifeng; Yu, Chao; Wang, Yunhui; Shi, Qi; Zhang, Yadong

2014-01-01

High-order harmonic generation from the asymmetric molecular ion HeH 2+ exposed to intense laser fields was investigated by quantum wave packet calculations in which the initial wave packet of HeH 2+ was prepared in the first excited 2pσ state. The calculated molecular harmonic plateau at low frequencies was effectively isolated and enhanced by adjusting the carrier-envelope phase (CEP) of the laser field. Furthermore, double-well model, time-dependent electronic density, electronic state population, and time-frequency analyses were presented to explain the underlying mechanism of the efficient isolated molecular plateau. By taking advantage of the CEP effect to control the electronic dynamics, this isolated molecular plateau can be used to generate high-intensity single attosecond pulses.

High-harmonic spectroscopy of oriented OCS molecules: emission of even and odd harmonics.

Science.gov (United States)

Kraus, P M; Rupenyan, A; Wörner, H J

2012-12-07

We study the emission of even and odd high-harmonic orders from oriented OCS molecules. We use an intense, nonresonant femtosecond laser pulse superimposed with its phase-controlled second harmonic field to impulsively align and orient a dense sample of molecules from which we subsequently generate high-order harmonics. The even harmonics appear around the full revivals of the rotational dynamics. We demonstrate perfect coherent control over their intensity through the subcycle delay of the two-color fields. The odd harmonics are insensitive to the degree of orientation, but modulate with the degree of axis alignment, in agreement with calculated photorecombination dipole moments. We further compare the shape of the even and odd harmonic spectra with our calculations and determine the degree of orientation.

Harmonic supergraphs

International Nuclear Information System (INIS)

Galperin, A.; Ivanov, E.; Ogievetsky, V.; Sokatchev, E.

1985-01-01

This paper completes a descrption of the quantization procedure in the harmonic superspace approach. The Feynman rules for N=2 matter and Yang-Mills theories are derived and the various examples of harmonic supergraph calculations are given. Calculations appear to be not more difficult than those in the N=1 case. The integration over harmonic variables does not lead to any troubles, a non-locality in these disappears on-shell. The important property is that the quantum corrections are always writen as integrals over the full harmonic superspace even though the initial action is an integral over the analytic subspace. As a by-product our results imply a very simple proof of finiteness of a wide class of the N=4, d=2 non-linear Σ-models. The most general self-couplings of hypermultiplets including those with broken SU(2) are considered.The duality relations among the N=2 linear multiplet and both kinds of hypermultiplet are established

Correlation functions for the fractional generalized Langevin equation in the presence of internal and external noise

International Nuclear Information System (INIS)

Sandev, Trifce; Metzler, Ralf; Tomovski, Živorad

2014-01-01

We study generalized fractional Langevin equations in the presence of a harmonic potential. General expressions for the mean velocity and particle displacement, the mean squared displacement, position and velocity correlation functions, as well as normalized displacement correlation function are derived. We report exact results for the cases of internal and external friction, that is, when the driving noise is either internal and thus the fluctuation-dissipation relation is fulfilled or when the noise is external. The asymptotic behavior of the generalized stochastic oscillator is investigated, and the case of high viscous damping (overdamped limit) is considered. Additional behaviors of the normalized displacement correlation functions different from those for the regular damped harmonic oscillator are observed. In addition, the cases of a constant external force and the force free case are obtained. The validity of the generalized Einstein relation for this process is discussed. The considered fractional generalized Langevin equation may be used to model anomalous diffusive processes including single file-type diffusion

Magnetic fluid droplet in a harmonic electric field

Energy Technology Data Exchange (ETDEWEB)

Kvasov, D., E-mail: kvasovdmitry@gmail.com [Lomonosov Moscow State University, Moscow (Russian Federation); Naletova, V. [Lomonosov Moscow State University, Moscow (Russian Federation); Beketova, E.; Dikanskii, Yu. [North-Caucasus Federal University, Stavropol (Russian Federation)

2017-06-01

A magnetic fluid droplet immersed in oil in an applied harmonic electric field is studied experimentally and theoretically. It is shown that deformations of the droplet observed experimentally are not described by the well-known theory. New double-layer droplet model which describes experimental data well is proposed. - Highlights: • The magnetic fluid droplet in the oil in a harmonic electric field is studied. • The paradoxical flattening effect of the droplet is observed experimentally. • For explaining this effect the model of the double-layer droplet is proposed. • Numerical and experimental data coincide qualitatively and quantitatively.

Family structure, family functioning and adolescent well-being: the transcendent influence of parental style.

Science.gov (United States)

McFarlane, A H; Bellissimo, A; Norman, G R

1995-07-01

This study assessed the association between parental style, family functioning and adolescent well being, contrasting intact families with those of changed configuration. Eight hundred and one grade 10 general level teenagers in 11 high schools of a single educational system were the subjects. Results indicated that the configuration of the family was not the key determinant of effectiveness of family functioning. Instead the style of parenting turned out to be the main determinant of both family functioning and well being of the adolescents. While both "parents" were judged to have contributed to these outcomes cross gender effects were found.

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

Science.gov (United States)

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

2016-03-01

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

Large-Nc quantum chromodynamics and harmonic sums

Indian Academy of Sciences (India)

In the large- limit of QCD, two-point functions of local operators become harmonic sums. I review some properties which follow from this fact and which are relevant for phenomenological applications. This has led us to consider a class of analytic number theory functions as toy models of large- QCD which also is ...

Psychophysical estimates of cochlear phase response: masking by harmonic complexes.

Science.gov (United States)

Lentz, J J; Leek, M R

2001-12-01

Harmonic complexes with identical component frequencies and amplitudes but different phase spectra may be differentially effective as maskers. Such harmonic waveforms, constructed with positive or negative Schroeder phases, have similar envelopes and identical long-term power spectra, but the positive Schroeder-phase waveform is typically a less effective masker than the negative Schroeder-phase waveform. These masking differences have been attributed to an interaction between the masker phase spectrum and the phase characteristic of the basilar membrane. To explore this relationship, the gradient of stimulus phase change across masker bandwidth was varied by systematically altering the Schroeder-phase algorithm. Observers detected a signal tone added in-phase to a single component of a masker whose frequencies ranged from 200 to 5000 Hz, with a fundamental frequency of 100 Hz. For signal frequencies of 1000-4000 Hz, differences in masking across the harmonic complexes could be as large as 5-10 dB for phase gradients changing by only 10%. The phase gradient that resulted in a minimum amount of masking varied with signal frequency, with low frequencies masked least effectively by stimuli with rapidly changing component phases and high frequencies masked by stimuli with more shallow phase gradients. A gammachirp filter was implemented to model these results, predicting the qualitative changes in curvature of the phase-byfrequency function estimated from the empirical data: In some cases, small modifications to the gammachirp filter produced better quantitative predictions of curvature changes across frequency, but this filter, as implemented here, was unable to accurately represent all the data.

Neural correlates of processing harmonic expectancy violations in children and adolescents with OCD.

Science.gov (United States)

Buse, Judith; Roessner, Veit

2016-01-01

It has been suggested that patients with obsessive-compulsive disorder (OCD) exhibit enhanced awareness of embedded stimulus patterns as well as enhanced allocation of attention towards unexpected stimuli. Our study aimed at investigating these OCD characteristics by running the harmonic expectancy violation paradigm in 21 boys with OCD and 29 healthy controls matched for age, gender and IQ during a functional magnetic resonance imaging (fMRI) scan. Each trial consisted of a chord sequence in which the first four chords induced a strong expectancy for a harmonic chord at the next position. In 70% of the trials the fifth chord fulfilled this expectancy (harmonic condition), while in 30% the expectancy was violated (disharmonic condition). Overall, the harmonic condition elicited blood-oxygen-level dependent (BOLD) activation in the auditory cortex, while during the disharmonic condition the precuneus, the auditory cortex, the medial frontal gyrus, the premotor cortex, the lingual gyrus, the inferior frontal gyrus and the superior frontal gyrus were activated. In a cluster extending from the right superior temporal gyrus to the inferior frontal gyrus, boys with OCD exhibited increased activation compared to healthy controls in the harmonic condition and decreased activation in the disharmonic condition. Our findings might indicate that patients with OCD are excessively engaged in processing the implicit structure embedded in music stimuli, but they speak against the suggestion that OCD is associated with a misallocation of attention towards the processing of unexpected stimuli.

Neural correlates of processing harmonic expectancy violations in children and adolescents with OCD

Directory of Open Access Journals (Sweden)

Judith Buse

2016-01-01

Full Text Available It has been suggested that patients with obsessive–compulsive disorder (OCD exhibit enhanced awareness of embedded stimulus patterns as well as enhanced allocation of attention towards unexpected stimuli. Our study aimed at investigating these OCD characteristics by running the harmonic expectancy violation paradigm in 21 boys with OCD and 29 healthy controls matched for age, gender and IQ during a functional magnetic resonance imaging (fMRI scan. Each trial consisted of a chord sequence in which the first four chords induced a strong expectancy for a harmonic chord at the next position. In 70% of the trials the fifth chord fulfilled this expectancy (harmonic condition, while in 30% the expectancy was violated (disharmonic condition. Overall, the harmonic condition elicited blood-oxygen-level dependent (BOLD activation in the auditory cortex, while during the disharmonic condition the precuneus, the auditory cortex, the medial frontal gyrus, the premotor cortex, the lingual gyrus, the inferior frontal gyrus and the superior frontal gyrus were activated. In a cluster extending from the right superior temporal gyrus to the inferior frontal gyrus, boys with OCD exhibited increased activation compared to healthy controls in the harmonic condition and decreased activation in the disharmonic condition. Our findings might indicate that patients with OCD are excessively engaged in processing the implicit structure embedded in music stimuli, but they speak against the suggestion that OCD is associated with a misallocation of attention towards the processing of unexpected stimuli.

Mode matching in multiresonant plasmonic nanoantennas for enhanced second harmonic generation

Science.gov (United States)

Celebrano, Michele; Wu, Xiaofei; Baselli, Milena; Großmann, Swen; Biagioni, Paolo; Locatelli, Andrea; de Angelis, Costantino; Cerullo, Giulio; Osellame, Roberto; Hecht, Bert; Duò, Lamberto; Ciccacci, Franco; Finazzi, Marco

2015-05-01

Boosting nonlinear frequency conversion in extremely confined volumes remains a challenge in nano-optics research, but can enable applications in nanomedicine, photocatalysis and background-free biosensing. To obtain brighter nonlinear nanoscale sources, approaches that enhance the electromagnetic field intensity and counter the lack of phase matching in nanoplasmonic systems are often employed. However, the high degree of symmetry in the crystalline structure of plasmonic materials (metals in particular) and in nanoantenna designs strongly quenches second harmonic generation. Here, we describe doubly-resonant single-crystalline gold nanostructures with no axial symmetry displaying spatial mode overlap at both the excitation and second harmonic wavelengths. The combination of these features allows the attainment of a nonlinear coefficient for second harmonic generation of ˜5 × 10-10 W-1, enabling a second harmonic photon yield higher than 3 × 106 photons per second. Theoretical estimations point toward the use of our nonlinear plasmonic nanoantennas as efficient platforms for label-free molecular sensing.

Advanced Gouy phase high harmonics interferometer

Science.gov (United States)

Mustary, M. H.; Laban, D. E.; Wood, J. B. O.; Palmer, A. J.; Holdsworth, J.; Litvinyuk, I. V.; Sang, R. T.

2018-05-01

We describe an extreme ultraviolet (XUV) interferometric technique that can resolve ∼100 zeptoseconds (10‑21 s) delay between high harmonic emissions from two successive sources separated spatially along the laser propagation in a single Gaussian beam focus. Several improvements on our earlier work have been implemented in the advanced interferometer. In this paper, we report on the design, characterization and optimization of the advanced Gouy phase interferometer. Temporal coherence for both atomic argon and molecular hydrogen gases has been observed for several harmonic orders. It has been shown that phase shift of XUV pulses mainly originates from the emission time delay due to the Gouy phase in the laser focus and the observed interference is independent of the generating medium. This interferometer can be a useful tool for measuring the relative phase shift between any two gas species and for studying ultrafast dynamics of their electronic and nuclear motion.

Lower Side Switching Modification of SHEPWM for Single H-Bridge Unipolar Inverter

Science.gov (United States)

Aihsan, M. Z.

2018-03-01

Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) is a famous fundamental frequency method for both single stage H-bridge inverter and cascaded multilevel inverters. The main function of SHEPWM is to eliminate the selective lower order of odd harmonic such 3rd, 5th 7th and 9th of the output voltage of the inverter but maintain the fundamental component. In this paper, the 5kHz of the unipolar SHEPWM switching scheme of the inverter is developed and later will be compared to the modified SHEPWM switching scheme. The performance of this inverter is measured through the final total harmonic distortion (THD), the efficiency of the whole system and the natural shape of the output after LC filter.

Neutron lifetime well logging methods and apparatus

International Nuclear Information System (INIS)

Paap, H.J.; Pitts, R.W.

1974-01-01

A method for investigating the earth formations surrounding a well borehole, comprising the steps of: continuously generating high energy neutrons in the borehole and bombarding the surrounding media with such neutrons to develop a cloud of thermal neutrons therein; modulating the intensity of said high energy neutrons harmonically as a function of time in order to intensity modulate said cloud of thermal neutrons as a function of time; and measuring a time-dependant thermal neutron characteristic of said intensity modulated cloud of thermal neutrons

Non-Characteristic Harmonics Analysis of the ITER Pulsed Power Supply

International Nuclear Information System (INIS)

Yang Wei; Xu Liuwei; Fu Peng; Lu Huawei; Sheng Zhicai

2009-01-01

The ITER pulsed power supply system will be operated in non-ideal conditions including an asymmetric firing angle, an unbalanced AC supply and an unbalanced AC side impedance of the transformer. In this study the switching functions approach is used to calculate non-characteristic harmonics in ITER, possibly caused by an AC-DC convertor in non-ideal conditions. A PSCAD simulation model is set up to study the non-characteristic harmonics in those non-ideal conditions. It is found that the non-characteristic harmonic does appear and the simulation result is in accordance with the calculating strategy. (fusion engineering)

High order harmonic generation from plasma mirrors

International Nuclear Information System (INIS)

George, H.

2010-01-01

When an intense laser beam is focused on a solid target, the target's surface is rapidly ionized and forms dense plasma that reflects the incident field. For laser intensities above few 10 to the power of 15 Wcm -2 , high order harmonics of the laser frequency, associated in the time domain to a train of atto-second pulses (1 as 10 -18 s), can be generated upon this reflection. In this thesis, we developed numerical tools to reveal original aspects of harmonic generation mechanisms in three different interaction regime: the coherent wake emission, the relativistic emission and the resonant absorption. In particular, we established the role of these mechanisms when the target is a very thin foil (thickness of the order of 100 nm). Then we study experimentally the spectral, spatial and coherence properties of the emitted light. We illustrate how to exploit these measurements to get information on the plasma mirror dynamics on the femtosecond and atto-second time scales. Last, we propose a technique for the single-shot complete characterization of the temporal structure of the harmonic light emission from the laser-plasma mirror interaction. (author)

Minimum Wages and the Economic Well-Being of Single Mothers

Science.gov (United States)

Sabia, Joseph J.

2008-01-01

Using pooled cross-sectional data from the 1992 to 2005 March Current Population Survey (CPS), this study examines the relationship between minimum wage increases and the economic well-being of single mothers. Estimation results show that minimum wage increases were ineffective at reducing poverty among single mothers. Most working single mothers…

Application of transfer function based harmonic study method to an offshore wind farm

Energy Technology Data Exchange (ETDEWEB)

Chen, Yu; Bollen, Math [STRI AB, Gothenburg (Sweden); Martins, Marcia [Alstom Wind, Barcelona (Spain)

2012-07-01

This paper presents the results from a harmonic study for a planned offshore wind farm with 252 MW installed capacity. Both the collection grid and the public grid are modelled in detail using Powerfactory. Both primary emission from wind turbines and secondary emission due to the distortion in the public grid are studied. Besides, due to the presence of HVDC platform and another two wind farms, details of which are not known at the moment, a sensitivity analysis is conducted to investigate the potential influence on the harmonic emission. (orig.)

Efficient second- and third-harmonic radiation generation from relativistic laser-plasma interactions

Energy Technology Data Exchange (ETDEWEB)

Singh, Mamta; Gupta, D. N., E-mail: dngupta@physics.du.ac.in [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Suk, H. [Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 500 712 (Korea, Republic of)

2015-06-15

We propose an idea to enhance the efficiency of second- and third-harmonic generation by considering the amplitude-modulation of the fundamental laser pulse. A short-pulse laser of finite spot size is modeled as amplitude modulated in time. Amplitude-modulation of fundamental laser contributes in quiver velocity of the plasma electrons and produces the strong plasma-density perturbations, thereby increase in current density at second- and third-harmonic frequency. In a result, the conversion efficiency of harmonic generation increases significantly. Power conversion efficiency of harmonic generation process is the increasing function of the amplitude-modulation parameter of the fundamental laser beam. Harmonic power generated by an amplitude modulated laser is many folds higher than the power obtained in an ordinary case.

Efficient second- and third-harmonic radiation generation from relativistic laser-plasma interactions

International Nuclear Information System (INIS)

Singh, Mamta; Gupta, D. N.; Suk, H.

2015-01-01

We propose an idea to enhance the efficiency of second- and third-harmonic generation by considering the amplitude-modulation of the fundamental laser pulse. A short-pulse laser of finite spot size is modeled as amplitude modulated in time. Amplitude-modulation of fundamental laser contributes in quiver velocity of the plasma electrons and produces the strong plasma-density perturbations, thereby increase in current density at second- and third-harmonic frequency. In a result, the conversion efficiency of harmonic generation increases significantly. Power conversion efficiency of harmonic generation process is the increasing function of the amplitude-modulation parameter of the fundamental laser beam. Harmonic power generated by an amplitude modulated laser is many folds higher than the power obtained in an ordinary case

Harmonic operation of high gain harmonic generation free electron laser

International Nuclear Information System (INIS)

Deng Haixiao; Chinese Academy of Sciences, Beijing; Dai Zhimin

2008-01-01

In high gain harmonic generation (HGHG) free electron laser (FEL), with the right choice of parameters of the modulator undulator, the dispersive section and the seed laser, one may make the spatial bunching of the electron beam density distribution correspond to one of the harmonic frequencies of the radiator radiation, instead of the fundamental frequency of the radiator radiation in conventional HGHG, thus the radiator undulator is in harmonic operation (HO) mode. In this paper, we investigate HO of HGHG FEL. Theoretical analyses with universal method are derived and numerical simulations in ultraviolet and deep ultraviolet spectral regions are given. It shows that the power of the 3rd harmonic radiation in the HO of HGHG may be as high as 18.5% of the fundamental power level. Thus HO of HGHG FEL may obtain short wavelength by using lower beam energy. (authors)

Active power filter for harmonic compensation using a digital dual-mode-structure repetitive control approach

DEFF Research Database (Denmark)

Zou, Zhixiang; Wang, Zheng; Cheng, Ming

2012-01-01

This paper presents an digital dual-mode-structure repetitive control approach for the single-phase shunt active power filter (APF), which aims to enhance the tracking ability and eliminate arbitrary order harmonic. The proposed repetitive control scheme blends the characteristics of both odd......-harmonic repetitive control and even-harmonic repetitive control. Moreover, the convergence rate is faster than conventional repetitive controller. Additionally, the parameters have been designed and optimized for the dual-mode structure repetitive control to improve the performance of APF system. Experimental...

On-line reconstruction of in-core power distribution by harmonics expansion method

International Nuclear Information System (INIS)

Wang Changhui; Wu Hongchun; Cao Liangzhi; Yang Ping

2011-01-01

Highlights: → A harmonics expansion method for the on-line in-core power reconstruction is proposed. → A harmonics data library is pre-generated off-line and a code named COMS is developed. → Numerical results show that the maximum relative error of the reconstruction is less than 5.5%. → This method has a high computational speed compared to traditional methods. - Abstract: Fixed in-core detectors are most suitable in real-time response to in-core power distributions in pressurized water reactors (PWRs). In this paper, a harmonics expansion method is used to reconstruct the in-core power distribution of a PWR on-line. In this method, the in-core power distribution is expanded by the harmonics of one reference case. The expansion coefficients are calculated using signals provided by fixed in-core detectors. To conserve computing time and improve reconstruction precision, a harmonics data library containing the harmonics of different reference cases is constructed. Upon reconstruction of the in-core power distribution on-line, the two closest reference cases are searched from the harmonics data library to produce expanded harmonics by interpolation. The Unit 1 reactor of DayaBay Nuclear Power Plant (DayaBay NPP) in China is considered for verification. The maximum relative error between the measurement and reconstruction results is less than 5.5%, and the computing time is about 0.53 s for a single reconstruction, indicating that this method is suitable for the on-line monitoring of PWRs.

Inertial piezoelectric linear motor driven by a single-phase harmonic wave with automatic clamping mechanism

Science.gov (United States)

He, Liangguo; Chu, Yuheng; Hao, Sai; Zhao, Xiaoyong; Dong, Yuge; Wang, Yong

2018-05-01

A novel, single-phase, harmonic-driven, inertial piezoelectric linear motor using an automatic clamping mechanism was designed, fabricated, and tested to reduce the sliding friction and simplify the drive mechanism and power supply control of the inertial motor. A piezoelectric bimorph and a flexible hinge were connected in series to form the automatic clamping mechanism. The automatic clamping mechanism was used as the driving and clamping elements. A dynamic simulation by Simulink was performed to prove the feasibility of the motor. The finite element method software COMSOL was used to design the structure of the motor. An experimental setup was built to validate the working principle and evaluate the performance of the motor. The prototype motor outputted a no-load velocity of 3.178 mm/s at a voltage of 220 Vp-p and a maximum traction force of 4.25 N under a preload force of 8 N. The minimum resolution of 1.14 μm was achieved at a driving frequency of 74 Hz, a driving voltage of 50 Vp-p, and a preload force of 0 N.

High-brightness high-order harmonic generation at 13 nm with a long gas jet

International Nuclear Information System (INIS)

Kim, Hyung Taek; Kim, I Jong; Lee, Dong Gun; Park, Jong Ju; Hong, Kyung Han; Nam, Chang Hee

2002-01-01

The generation of high-order harmonics is well-known method producing coherent extreme-ultraviolet radiation with pulse duration in the femtosecond regime. High-order harmonics have attracted much attention due to their unique features such as coherence, ultrashort pulse duration, and table-top scale system. Due to these unique properties, high-order harmonics have many applications of atomic and molecular spectroscopy, plasma diagnostics and solid-state physics. Bright generation of high-order harmonics is important for actual applications. Especially, the generation of strong well-collimated harmonics at 13 nm can be useful for the metrology of EUV lithography optics because of the high reflectivity of Mo-Si mirrors at this wavelength. The generation of bright high-order harmonics is rather difficult in the wavelength region below 15nm. Though argon and xenon gases have large conversion efficiency, harmonic generation from these gases is restricted to wavelengths over 20 nm due to low ionization potential. Hence, we choose neon for the harmonic generation around 13 nm; it has larger conversion efficiency than helium and higher ionization potential than argon. In this experiment, we have observed enhanced harmonic generation efficiency and low beam divergence of high-order harmonics from a elongated neon gas jet by the enhancement of laser propagation in an elongated gas jet. A uniform plasma column was produced when the gas jet was exposed to converging laser pulses.

Elementary derivation of the quantum propagator for the harmonic oscillator

Science.gov (United States)

Shao, Jiushu

2016-10-01

Operator algebra techniques are employed to derive the quantum evolution operator for the harmonic oscillator. The derivation begins with the construction of the annihilation and creation operators and the determination of the wave function for the coherent state as well as its time-dependent evolution, and ends with the transformation of the propagator in a mixed position-coherent-state representation to the desired one in configuration space. Throughout the entire procedure, besides elementary operator manipulations, it is only necessary to solve linear differential equations and to calculate Gaussian integrals.

Crypto-harmonic oscillator in higher dimensions: classical and quantum aspects

International Nuclear Information System (INIS)

Ghosh, Subir; Majhi, Bibhas Ranjan

2008-01-01

We study complexified harmonic oscillator models in two and three dimensions. Our work is a generalization of the work of Smilga (2007 Preprint 0706.4064 (J. Phys. A: Math. Theor. at press)) who initiated the study of these Crypto-gauge invariant models that can be related to PT-symmetric models. We show that rotational symmetry in higher spatial dimensions naturally introduces more constraints (in contrast to Smilga (2007 Preprint 0706.4064 (J. Phys. A: Math. Theor. at press)) where one deals with a single constraint) with a much richer constraint structure. Some common as well as distinct features in the study of the same Crypto-oscillator in different dimensions are revealed. We also quantize the two dimensional Crypto-oscillator

Shapes of nuclear configurations in a cranked harmonic oscillator model

International Nuclear Information System (INIS)

Troudet, T.; Arvieu, R.

1980-05-01

The shapes of nuclear configurations are calculated using Slater determinants built with cranked harmonic oscillator single particle states. The nuclear forces role is played by a volume conservation condition (of the potential or of the density) in a first part. In a second part, we have used the finite range, density dependent interaction of Cogny. A very simple classification of configurations emerges in the first part, the relevant parameter being the equatorial eccentricity of the nuclear density. A critical equatorial eccentricity is obtained which governs the accession to the case for which the nucleus is oblate and symmetric around its axis of rotation. Nuclear configurations calculated in the second part observe remarkably well these behaviors

General Lp-harmonic Blaschke bodies

Indian Academy of Sciences (India)

Lutwak introduced the harmonic Blaschke combination and the harmonic Blaschke body of a star body. Further, Feng and Wang introduced the concept of the -harmonic Blaschke body of a star body. In this paper, we define the notion of general -harmonic Blaschke bodies and establish some of its properties.

Statistical mechanics of quantum one-dimensional damped harmonic oscillator

International Nuclear Information System (INIS)

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

Squeezing and entanglement in doubly resonant, type II, second-harmonic generation

DEFF Research Database (Denmark)

Andersen, Ulrik Lund; Buchhave, Preben

2003-01-01

We investigate, theoretically, the generation of bright and vacuum-squeezed light as well as entanglement in intracavity, type II, phase-matched second-harmonic generation. The cavity in which the crystal is embedded is resonant at the fundamental frequency but not at the second-harmonic frequenc...

On computing ellipsoidal harmonics using Jekeli's renormalization

Czech Academy of Sciences Publication Activity Database

Sebera, Josef; Bouman, J.; Bosch, W.

2012-01-01

Roč. 86, č. 9 (2012), s. 713-726 ISSN 0949-7714 Institutional support: RVO:67985815 Keywords : Earth's gravitational field * spherical and ellipsoidal harmonics * hypergeometric function Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.808, year: 2012

Action principle for the generalized harmonic formulation of general relativity

International Nuclear Information System (INIS)

Brown, J. David

2011-01-01

An action principle for the generalized harmonic formulation of general relativity is presented. The action is a functional of the spacetime metric and the gauge source vector. An action principle for the Z4 formulation of general relativity has been proposed recently by Bona, Bona-Casas, and Palenzuela. The relationship between the generalized harmonic action and the Bona, Bona-Casas, and Palenzuela action is discussed in detail.

Variance Function Partially Linear Single-Index Models1.

Science.gov (United States)

Lian, Heng; Liang, Hua; Carroll, Raymond J

2015-01-01

We consider heteroscedastic regression models where the mean function is a partially linear single index model and the variance function depends upon a generalized partially linear single index model. We do not insist that the variance function depend only upon the mean function, as happens in the classical generalized partially linear single index model. We develop efficient and practical estimation methods for the variance function and for the mean function. Asymptotic theory for the parametric and nonparametric parts of the model is developed. Simulations illustrate the results. An empirical example involving ozone levels is used to further illustrate the results, and is shown to be a case where the variance function does not depend upon the mean function.

3rd harmonic electron cyclotron resonant heating absorption enhancement by 2nd harmonic heating at the same frequency in a tokamak

International Nuclear Information System (INIS)

Gnesin, S; Coda, S; Goodman, T P; Decker, J; Peysson, Y; Mazon, D

2012-01-01

The fundamental mechanisms responsible for the interplay and synergy between the absorption dynamics of extraordinary-mode electron cyclotron waves at two different harmonic resonances (the 2nd and 3rd) are investigated in the TCV tokamak. An enhanced 3rd harmonic absorption in the presence of suprathermal electrons generated by 2nd harmonic heating is predicted by Fokker–Planck simulations, subject to complex alignment requirements in both physical space and momentum space. The experimental signature for the 2nd/3rd harmonic synergy is sought through the suprathermal bremsstrahlung emission in the hard x-ray range of photon energy. Using a synthetic diagnostic, the emission variation due to synergy is calculated as a function of the injected power and of the radial transport of suprathermal electrons. It is concluded that in the present experimental setup a synergy signature has not been unambiguously detected. The detectability of the synergy is then discussed with respect to variations and uncertainties in the plasma density and effective charge in view of future optimized experiments. (paper)

Symmetry properties of second harmonics generated by antisymmetric Lamb waves

Science.gov (United States)

Zhu, Wujun; Xiang, Yanxun; Liu, Chang-Jun; Deng, Mingxi; Xuan, Fu-Zhen

2018-03-01

Symmetry properties of second harmonics generated by antisymmetric primary Lamb waves are systematically studied in this work. In theory, the acoustic field of second harmonic Lamb waves is obtained by using the perturbation approximation and normal modal method, and the energy flux transfer from the primary Lamb waves to second harmonics is mainly explored. Symmetry analyses indicate that either the symmetric or antisymmetric Lamb waves can merely generate the symmetric second harmonics. Finite element simulations are performed on the nonlinear Lamb wave propagation of the antisymmetric A0 mode in the low frequency region. The signals of the second harmonics and the symmetric second harmonic s0 mode are found to be exactly equivalent in the time domain. The relative acoustic nonlinearity parameter A2/A12 oscillates with the propagation distance, and the oscillation amplitude and spatial period are well consistent with the theoretical prediction of the A0-s0 mode pair, which means that only the second harmonic s0 mode is generated by the antisymmetric primary A0 mode. Experiments are further conducted to examine the cumulative generation of symmetric second harmonics for the antisymmetric-symmetric mode pair A3-s6. Results show that A2/A12 increases linearly with the propagation distance, which means that the symmetric second harmonic s6 mode is generated cumulatively by the antisymmetric primary A3 mode. The present investigation systematically corroborates the proposed theory that only symmetric second harmonics can be generated accompanying the propagation of antisymmetric primary Lamb waves in a plate.

Analysis of higher order harmonics with holographic reflection gratings

Science.gov (United States)

Mas-Abellan, P.; Madrigal, R.; Fimia, A.

2017-05-01

Silver halide emulsions have been considered one of the most energetic sensitive materials for holographic applications. Nonlinear recording effects on holographic reflection gratings recorded on silver halide emulsions have been studied by different authors obtaining excellent experimental results. In this communication specifically we focused our investigation on the effects of refractive index modulation, trying to get high levels of overmodulation that will produce high order harmonics. We studied the influence of the overmodulation and its effects on the transmission spectra for a wide exposure range by use of 9 μm thickness films of ultrafine grain emulsion BB640, exposed to single collimated beams using a red He-Ne laser (wavelength 632.8 nm) with Denisyuk configuration obtaining a spatial frequency of 4990 l/mm recorded on the emulsion. The experimental results show that high overmodulation levels of refractive index produce second order harmonics with high diffraction efficiency (higher than 75%) and a narrow grating bandwidth (12.5 nm). Results also show that overmodulation produce diffraction spectra deformation of the second order harmonic, transforming the spectrum from sinusoidal to approximation of square shape due to very high overmodulation. Increasing the levels of overmodulation of refractive index, we have obtained higher order harmonics, obtaining third order harmonic with diffraction efficiency (up to 23%) and narrowing grating bandwidth (5 nm). This study is the first step to develop a new easy technique to obtain narrow spectral filters based on the use of high index modulation reflection gratings.

Improving the performance of the power supply of the MGC-20 cyclotron harmonic coils

International Nuclear Information System (INIS)

Hagras, A.A.M

2008-01-01

Correction of lower harmonics of the MGC-20 cyclotron magnetic field is of great importance for its operation. Actually, stability of the acceleration process, attainment of the final energy of the accelerated beam and efficiency of the beam extraction system depend on the lower harmonics control. Error in the magnetic field lower harmonics can reduce the efficiency of the beam extraction resulting in complete disappearance of the extracted beam of the cyclotron. For control of the cyclotron MGC-20 magnetic field lower harmonics, the so called inner and outer harmonic coils are provided.These harmonic coils must be fed by a very high accuracy current source power supply. This power supply must be equipped with a high resolution measurement and control scheme to achieve the imposed requirements of adjustment of the first harmonic magnetic field.Harmonic coils are supplied with conventional SCR controlled converters with analog control strategy. Frequent interruption of operation and difficulties in the adjustment of harmonic coil current lead to economical and research - time losses.This research project aims to replace this conventional system with a more effective, accurate and less complicated digital control system based on Motorola DSP56F807 and high switching frequency power circuit. Actually all the bulky modules including the analog integrator, the signal monitoring and protection, the pulse phase modulator and the comparator are all replaced by a single module circuit.

The Harmonically Coupled 2-Beam FEL

CERN Document Server

McNeil, Brian W J

2004-01-01

A 1-D model of a 2-beam Free Electron Laser amplifier is presented. The two co-propagating electron beams have different energies, chosen so that the fundamental resonant FEL interaction of the higher energy beam is at an harmonic of the lower energy beam. In this way, a coupling between the FEL interactions of the two beams occurs via the harmonic components of the electron bunching and radiation emission of the lower energy interaction. Such resonantly coupled FEL interactions may offer potential benefits over existing single beam FEL schemes. A simple example is presented where the lower energy FEL interaction only is seeded with radiation at its fundamental resonant wavelength. It is predicted that the coherence properties of this seed field are transfered via the resonantly coupled FEL interaction to the un-seeded higher energy FEL interaction, thereby improving its coherence properties over that of a SASE interaction alone. This method may offer an alternative seeding scheme for FELs operating in the XU...

The DAΦNE 3RD harmonic cavity

International Nuclear Information System (INIS)

Alesini, D.; Boni, R.; Clozza, A.; Gallo, A.; Guiducci, S.; Marcellini, F.; Migliorati, M.; Palumbo, L.; Pellegrino, L.; Sgamma, F.; Zobov, M.

2001-01-01

The installation of a passive 3rd harmonic cavity in both the e + and e - rings of the Frascati Φ-factory DAΦNE has been decided in order to improve the Touschek lifetime by increasing the bunch length. The implications of the RF harmonic system on the beam dynamics, in particular those related to the gap in the bunch filling pattern, have been carefully studied by means of analytical and numerical tools. A single-cell cavity incorporating a ferrite ring for the HOM damping has been designed through the extensive use of MAFIA and HFSS simulation codes. One cavity prototype has been built and extensively bench tested, while the fabrication of the two final cavities is almost completed. A description of the design and construction activities, and a set of experimental measurements are reported in this paper

Flux distribution in single phase, Si-Fe, wound transformer cores

International Nuclear Information System (INIS)

Loizos, George; Kefalas, Themistoklis; Kladas, Antonios; Souflaris, Thanassis; Paparigas, Dimitris

2008-01-01

This paper shows experimental results of longitudinal flux density and its harmonics at the limb, the yoke and the corner as well as normal flux in the step lap joint of a single phase, Si-Fe, wound transformer core. Results show that the flux density as well as the harmonics content is higher in the inner (window) side of the core and reduces gradually towards the outer side. Variations of flux density distribution between the limb and the corner or the yoke of the core were observed. A full record of normal flux around the step lap region of the model core was also obtained. Longitudinal and normal flux findings will enable the development of more accurate numerical models that describe the magnetic behavior of magnetic cores

Effect of the magnetic field on the nonlinear optical rectification and second and third harmonic generation in double δ-doped GaAs quantum wells

Science.gov (United States)

Martínez-Orozco, J. C.; Rojas-Briseño, J. G.; Rodríguez-Magdaleno, K. A.; Rodríguez-Vargas, I.; Mora-Ramos, M. E.; Restrepo, R. L.; Ungan, F.; Kasapoglu, E.; Duque, C. A.

2017-11-01

In this paper we are reporting the computation for the Nonlinear Optical Rectification (NOR) and the Second and Third Harmonic Generation (SHG and THG) related with electronic states of asymmetric double Si-δ-doped quantum well in a GaAs matrix when this is subjected to an in-plane (x-oriented) constant magnetic field effect. The work is performed in the effective mass and parabolic band approximations in order to compute the electronic structure for the system by a diagonalization procedure. The expressions for the nonlinear optical susceptibilities, χ0(2), χ2ω(2), and χ3ω(3), are those arising from the compact matrix density formulation and stand for the NOR, SHG, and THG, respectively. This asymmetric double δ-doped quantum well potential profile actually exhibits nonzero NOR, SHG, and THG responses which can be easily controlled by the in-plane (x-direction) externally applied magnetic field. In particular we find that for the chosen configuration the harmonic generation is in the far-infrared/THz region, thus and becoming suitable building blocks for photodetectors in this range of the electromagnetic spectra.

Strong nonlinear harmonic generation in a PZT/Aluminum resonator

Energy Technology Data Exchange (ETDEWEB)

Parenthoine, D; Haumesser, L; Meulen, F Vander; Tran-Huu-Hue, L-P, E-mail: parenthoine@univ-tours.f [University Francois Rabelais of Tours, U 930 Imagerie et Cerveau, CNRS 2448, ENIVL, rue de la Chocolaterie, BP 3410, 41034 Blois (France)

2009-11-01

In this work, the extentional vibration mode of a coupled PZT/ Aluminum rod resonator is studied experimentally. Geometrical characteristics of the PZT are its 27 mm length and its 4x4 mm{sup 2} cross section area. The excitation voltage consists in sinusoidal bursts in the frequency range (20-80 kHz). Velocity measurements are performed at both ends of this system, using a laser probe. Strong harmonic distortions in the mechanical response (up to -20 dB with respect to the primary wave amplitude) have been observed. The corresponding input levels are far lower than those which are necessary to observe quadratic second harmonic generation in a free PZT resonator. The strong nonlinear effect can be explained as a super-harmonic resonance of the system due to a specific ratio between the eigen frequencies of the two parts of the resonator. Evolution of fundamental and harmonic responses are observed as a function of input levels, highlighting hysteretic behavior.

Time Harmonic Elastography Reveals Sensitivity of Liver Stiffness to Water Ingestion.

Science.gov (United States)

Ipek-Ugay, Selcan; Tzschätzsch, Heiko; Hudert, Christian; Marticorena Garcia, Stephan Rodrigo; Fischer, Thomas; Braun, Jürgen; Althoff, Christian; Sack, Ingolf

2016-06-01

The aim of the study was to test the sensitivity of liver stiffness (LS) measured by time harmonic elastography in large tissue windows to water uptake and post-prandial effects. Each subject gave written informed consent to participate in this institutional review board-approved prospective study. LS was measured by time harmonic elastography in 10 healthy volunteers pre- and post-prandially, as well as before, directly after and 2 h after drinking water. The LS-time function during water intake was measured in 14 scans over 3 h in five volunteers. LS increased by 10% (p = 0.0015) post-prandially and by 11% (p = 0.0024) after pure water ingestion, and decreased to normal values after 2 h. LS was lower after overnight fasting than after 2-h fasting (3%, p = 0.04). Over the time course, LS increased to post-water peak values 15 min after drinking 0.25 L water and remained unaffected by further ingestion of water. In conclusion, our study indicates that LS measured by time harmonic elastography represents an effective-medium property sensitive to physiologic changes in vascular load of the liver. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Theory of nonlinear harmonic generation in free-electron lasers with helical wigglers

International Nuclear Information System (INIS)

Geloni, G.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

2007-05-01

CoherentHarmonicGeneration (CHG), and in particularNonlinearHarmonicGeneration (NHG), is of importance for both short wavelength Free-Electron Lasers (FELs), in relation with the achievement of shorter wavelengths with a fixed electron-beam energy, and high-average power FEL resonators, in relation with destructive effects of higher harmonics radiation on mirrors. In this paper we present a treatment of NHG from helical wigglers with particular emphasis on the second harmonic. Our study is based on an exact analytical solution of Maxwell's equations, derived with the help of a Green's function method. In particular, we demonstrate that nonlinear harmonic generation (NHG) fromhelicalwigglers vanishes on axis. Our conclusion is in open contrast with results in literature, that include a kinematical mistake in the description of the electron motion. (orig.)

General Lp-harmonic Blaschke bodies

Indian Academy of Sciences (India)

Abstract. Lutwak introduced the harmonic Blaschke combination and the harmonic. Blaschke body of a star body. Further, Feng and Wang introduced the concept of the L p- harmonic Blaschke body of a star body. In this paper, we define the notion of general. L p-harmonic Blaschke bodies and establish some of its ...

High-Harmonic Generation in Solids with and without Topological Edge States

Science.gov (United States)

Bauer, Dieter; Hansen, Kenneth K.

2018-04-01

High-harmonic generation in the two topological phases of a finite, one-dimensional, periodic structure is investigated using a self-consistent time-dependent density functional theory approach. For harmonic photon energies smaller than the band gap, the harmonic yield is found to differ by up to 14 orders of magnitude for the two topological phases. This giant topological effect is explained by the degree of destructive interference in the harmonic emission of all valence-band (and edge-state) electrons, which strongly depends on whether or not topological edge states are present. The combination of strong-field laser physics with topological condensed matter opens up new possibilities to electronically control strong-field-based light or particle sources or—conversely—to steer by all optical means topological electronics.

The Tax harmonization in open regionalism ; The European model

Directory of Open Access Journals (Sweden)

Mouloud MELIKAOUI

2014-06-01

Full Text Available This research examines the subject of alternative regionalism or open regionalism and reality within the multilateral trading system, based on growing liberalization of trade, and the problem of compatibility between them, as well as the limits of economic policy harmonization in the framework of Open regionalism, special tax harmonization, in the light of economic and tax disparities of the Member States, with an overview of the European tax harmonization and limits. The Study concluded the importance of tax harmonization as a tool by activation of the concept of open regionalism, through facilitating capitals flows and investments between member states and reduction of the négatives phenomena of tax. It recommended the need to emphasizing on the importance of gradually harmonization for tax policy, and expand the rule of tax treaties and exchange of tax information and experiences between countries, This is in light a holistic approach to other economic policies as a the exchange rate policy and monetary policy, just as is the case in the European model.

Microwave second-harmonic response of ceramic MgB2 samples

International Nuclear Information System (INIS)

Agliolo Gallitto, A.; Bonsignore, G.; Li Vigni, M.

2005-01-01

Nonlinear microwave response of different ceramic MgB 2 samples has been investigated by the technique of second-harmonic emission. The second-harmonic signal has been investigated as a function of temperature, DC magnetic field and input microwave power. The attention has mainly been devoted to the response at low magnetic fields, where nonlinear processes arising from motion of Abrikosov fluxons are ineffective. The results show that different mechanisms are responsible for the nonlinear response in the different ranges of temperature. At low temperatures, the nonlinear response is due to processes involving weak links. At temperatures close to T c , a further contribution to the harmonic emission is present; it can be ascribed to modulation of the order parameter by the microwave field and gives rise to a peak in the temperature dependence of the harmonic signal

Harmonic analysis in integrated energy system based on compressed sensing

International Nuclear Information System (INIS)

Yang, Ting; Pen, Haibo; Wang, Dan; Wang, Zhaoxia

2016-01-01

Highlights: • We propose a harmonic/inter-harmonic analysis scheme with compressed sensing theory. • Property of sparseness of harmonic signal in electrical power system is proved. • The ratio formula of fundamental and harmonic components sparsity is presented. • Spectral Projected Gradient-Fundamental Filter reconstruction algorithm is proposed. • SPG-FF enhances the precision of harmonic detection and signal reconstruction. - Abstract: The advent of Integrated Energy Systems enabled various distributed energy to access the system through different power electronic devices. The development of this has made the harmonic environment more complex. It needs low complexity and high precision of harmonic detection and analysis methods to improve power quality. To solve the shortages of large data storage capacities and high complexity of compression in sampling under the Nyquist sampling framework, this research paper presents a harmonic analysis scheme based on compressed sensing theory. The proposed scheme enables the performance of the functions of compressive sampling, signal reconstruction and harmonic detection simultaneously. In the proposed scheme, the sparsity of the harmonic signals in the base of the Discrete Fourier Transform (DFT) is numerically calculated first. This is followed by providing a proof of the matching satisfaction of the necessary conditions for compressed sensing. The binary sparse measurement is then leveraged to reduce the storage space in the sampling unit in the proposed scheme. In the recovery process, the scheme proposed a novel reconstruction algorithm called the Spectral Projected Gradient with Fundamental Filter (SPG-FF) algorithm to enhance the reconstruction precision. One of the actual microgrid systems is used as simulation example. The results of the experiment shows that the proposed scheme effectively enhances the precision of harmonic and inter-harmonic detection with low computing complexity, and has good

Cumulative Second Harmonic Generation in Lamb Waves for the Detection of Material Nonlinearities

International Nuclear Information System (INIS)

Bermes, Christian; Jacobs, Laurence J.; Kim, Jin-Yeon; Qu, Jianmin

2007-01-01

An understanding of the generation of higher harmonics in Lamb waves is of critical importance for applications such as remaining life prediction of plate-like structural components. The objective of this work is to use nonlinear Lamb waves to experimentally investigate inherent material nonlinearities in aluminum plates. These nonlinearities, e.g. lattice anharmonicities, precipitates or vacancies, cause higher harmonics to form in propagating Lamb waves. The amplitudes of the higher harmonics increase with increasing propagation distance due to the accumulation of nonlinearity while the Lamb wave travels along its path. Special focus is laid on the second harmonic, and a relative nonlinearity parameter is defined as a function of the fundamental and second harmonic amplitude. The experimental setup uses an ultrasonic transducer and a wedge for the Lamb wave generation, and laser interferometry for detection. The experimentally measured Lamb wave signals are processed with a short-time Fourier transformation (STFT), which yields the amplitudes at different frequencies as functions of time, allowing the observation of the nonlinear behavior of the material. The increase of the relative nonlinearity parameter with propagation distance as an indicator of cumulative second harmonic generation is shown in the results for the alloy aluminum 1100-H14

Reduction of the Harmonic Series Influences Musical Enjoyment With Cochlear Implants.

Science.gov (United States)

Nemer, John S; Kohlberg, Gavriel D; Mancuso, Dean M; Griffin, Brianna M; Certo, Michael V; Chen, Stephanie Y; Chun, Michael B; Spitzer, Jaclyn B; Lalwani, Anil K

2017-01-01

Cochlear implantation is associated with poor music perception and enjoyment. Reducing music complexity has been shown to enhance music enjoyment in cochlear implant (CI) recipients. In this study, we assess the impact of harmonic series reduction on music enjoyment. Prospective analysis of music enjoyment in normal-hearing (NH) individuals and CI recipients. Single tertiary academic medical center. NH adults (N = 20) and CI users (N = 8) rated the Happy Birthday song on three validated enjoyment modalities-musicality, pleasantness, and naturalness. Subjective rating of music excerpts. Participants listened to seven different instruments play the melody, each with five levels of harmonic reduction (Full, F3+F2+F1+F0, F2+F1+F0, F1+F0, F0). NH participants listened to the segments both with and without CI simulation. Linear mixed effect models (LME) and likelihood ratio tests were used to assess the impact of harmonic reduction on enjoyment. NH listeners without simulation rated segments with the first four harmonics (F3+F2+F1+F0) most pleasant and natural (p <0.001, p = 0.004). NH listeners with simulation rated the first harmonic alone (F0) most pleasant and natural (p <0.001, p = 0.003). Their ratings demonstrated a positive linear relationship between harmonic reduction and both pleasantness (slope estimate = 0.030, SE = 0.004, p <0.001, LME) and naturalness (slope estimate = 0.012, SE = 0.003, p = 0.003, LME). CI recipients also found the first harmonic alone (F0) to be most pleasant (p = 0.003), with a positive linear relationship between harmonic reduction and pleasantness (slope estimate = 0.029, SE = 0.008, p <0.001, LME). Harmonic series reduction increases music enjoyment in CI and NH individuals with or without CI simulation. Therefore, minimization of the harmonics may be a useful strategy for enhancing musical enjoyment among both NH and CI listeners.

Spherical harmonic expansion of short-range screened Coulomb interactions

Energy Technology Data Exchange (ETDEWEB)

Angyan, Janos G [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Gerber, Iann [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Marsman, Martijn [Institut fuer Materialphysik and Center for Computational Materials Science, Universitaet Wien, Sensengasse 8, A-1090, Vienna (Austria)

2006-07-07

Spherical harmonic expansions of the screened Coulomb interaction kernel involving the complementary error function are required in various problems in atomic, molecular and solid state physics, like for the evaluation of Ewald-type lattice sums or for range-separated hybrid density functionals. A general analytical expression is derived for the kernel, which is non-separable in the radial variables. With the help of series expansions a separable approximate form is proposed, which is in close analogy with the conventional multipole expansion of the Coulomb kernel in spherical harmonics. The convergence behaviour of these expansions is studied and illustrated by the electrostatic potential of an elementary charge distribution formed by products of Slater-type atomic orbitals.

Density Profiles, Energy, and Oscillation Strength of a Quantum Dot in Two Dimensions with a Harmonic Oscillator External Potential using an Orbital-free Energy Functional Based on Thomas–Fermi Theory

Directory of Open Access Journals (Sweden)

Suhufa Alfarisa

2016-03-01

Full Text Available This research aims i to determine the density profile and calculate the ground state energy of a quantum dot in two dimensions (2D with a harmonic oscillator potential using orbital-free density functional theory, and ii to understand the effect of the harmonic oscillator potential strength on the electron density profiles in the quantum dot. This study determines the total energy functional of the quantum dot that is a functional of the density that depends only on spatial variables. The total energy functional consists of three terms. The first term is the kinetic energy functional, which is the Thomas–Fermi approximation in this case. The second term is the external potential. The harmonic oscillator potential is used in this study. The last term is the electron–electron interactions described by the Coulomb interaction. The functional is formally solved to obtain the electron density as a function of spatial variables. This equation cannot be solved analytically, and thus a numerical method is used to determine the profile of the electron density. Using the electron density profiles, the ground state energy of the quantum dot in 2D can be calculated. The ground state energies obtained are 2.464, 22.26, 90.1957, 252.437, and 496.658 au for 2, 6, 12, 20, and 56 electrons, respectively. The highest electron density is localized close to the middle of the quantum dot. The density profiles decrease with the increasing distance, and the lowest density is at the edge of the quantum dot. Generally, increasing the harmonic oscillator potential strength reduces the density profiles around the center of the quantum dot.

Frequency chirp of harmonic and attosecond pulses

International Nuclear Information System (INIS)

Varju, K.; Johansson, P; L'Huillier, A.L.; Mairesse, Y.; Salieres, P.

2005-01-01

Full text: We have explored in detail the first- and second-order variations of the atomic phase as a function of the laser intensity and harmonic order. This unravels the similitudes and differences existing between the chirp of individual harmonic pulses and the chirp of the attosecond pulses. We show that the two techniques XFROG and RABITT used to characterize the two chirps (respectively) converge to give the same information, namely the values of the mixed partial derivatives of the atomic phase. This underlines the common physical origin of all these phenomena and provides a unified frame for their description and understanding. Ref. 1 (author)

Chirp analysis of high-order harmonics from atoms driven by intense femtosecond laser pulses

International Nuclear Information System (INIS)

Kim, Hyung Taek; Kim, I Jong; Hong, Kyung-Han; Lee, Dong Gun; Kim, Jung-Hoon; Nam, Chang Hee

2004-01-01

The spectral structure of harmonics was experimentally controlled by changing the chirp of femtosecond laser pulses, and the dependence of harmonic chirp on atomic species was analysed using harmonics from neon and helium. Experimental results and theoretical analysis based on the Wigner distribution function showed that the spectral structure varied sensitively to laser chirp and the harmonic chirp was determined by the competition between dynamically induced negative chirp and self-phase modulation induced positive chirp. The generation of sharp and bright harmonics was achieved with appropriately chirped laser pulses under given experimental conditions, especially negatively chirped pulses in the case of laser intensity above the saturation intensity for optical-field ionization

Ellipticity dependence of high harmonics generated using 400 nm driving lasers

Science.gov (United States)

Cheng, Yan; Khan, Sabih; Zhao, Kun; Zhao, Baozhen; Chini, Michael; Chang, Zenghu

2011-05-01

High order harmonics generated from 400 nm driving pulses hold promise of scaling photon flux of single attosecond pulses by one to two orders of magnitude. We report ellipticity dependence and phase matching of high order harmonics generated from such pulses in Neon gas target and compared them with similar measurements using 800 nm driving pulses. Based on measured ellipticity dependence, we predict that double optical gating (DOG) and generalized double optical gating (GDOG) can be employed to extract intense single attosecond pulses from pulse train, while polarization gating (PG) may not work for this purpose. This material is supported by the U.S. Army Research Office under grant number W911NF-07-1-0475, and by the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy.

Harmonic dissection versus electrocautery in breast surgery in regional Victoria.

Science.gov (United States)

Kiyingi, Andrew K; Macdonald, Leigh J; Shugg, Sarah A; Bollard, Ruth C

2015-05-01

Harmonic instruments are an alternative tool for surgical dissection. The aim of this study is to evaluate differences in clinical outcomes relating to harmonic dissection when compared with electrocautery in patients undergoing major breast surgery in a regional centre over a 3-year period. Retrospective chart analysis was conducted of 52 patients undergoing major breast surgery for carcinoma or ductal carcinoma in situ by a single surgeon in a regional centre from May 2008 to January 2011. Analysis involved the extraction of qualitative data relating to patient demographics, surgery type and specimen histopathology. Quantitative data were extracted relating to duration of surgery, duration of patient-controlled analgesia (PCA) use, length of hospital admission, drainage output and presence of infection, haematoma or seroma. Fifty-two patients underwent major breast surgery; harmonic dissection n = 32 and electrocautery n = 20. The two groups were comparable. There was no significant difference identified relating the outcome measures. The median operative duration was shorter in the harmonic dissection group, however, was not of statistical significance. No significant difference was identified between groups relating to length of inpatient stay, duration of PCA use and total volume wound drainage and total days of drainage. Incidence of seroma and infection in the groups was not significantly different. The harmonic dissection is safe and effective in major breast surgery. The study did not demonstrate any clinical advantage from the use of harmonic dissection in major breast surgery compared with electrocautery, nor was there any difference in the complication rates measured. © 2014 Royal Australasian College of Surgeons.

Pulse Compression of Phase-matched High Harmonic Pulses from a Time-Delay Compensated Monochromator

Directory of Open Access Journals (Sweden)

Ito Motohiko

2013-03-01

Full Text Available Pulse compression of single 32.6-eV high harmonic pulses from a time-delay compensated monochromator was demonstrated down to 11±3 fs by compensating the pulse front tilt. The photon flux was intensified up to 5.7×109 photons/s on target by implementing high harmonic generation under a phase matching condition in a hollow fiber used for increasing the interaction length.

21 CFR 870.1435 - Single-function, preprogrammed diagnostic computer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Single-function, preprogrammed diagnostic computer... Single-function, preprogrammed diagnostic computer. (a) Identification. A single-function, preprogrammed diagnostic computer is a hard-wired computer that calculates a specific physiological or blood-flow parameter...

On bunch lengthening using the fourth harmonic cavity in the NSLS VUV ring

International Nuclear Information System (INIS)

Wachtel, J.M.

1988-02-01

It has been suggested that the phase of the beam excited voltage in the harmonic cavity can be controlled by detuning its resonant frequency from the beam current harmonic. Unfortunately the detuning needed to flatten the acceleration waveform also corresponds to the region of Robinson instability for the harmonic cavity. Therefore, lengthening the bunch may be followed by large amplitude synchrotron oscillation of the bunch center of mass. Bunch lengthening is discussed in this note from several points of view. There follows a simple review of single electron oscillations in a quartic potential. Then equations are developed for the coupled oscillations of a cavity and a rigid bunch as a fully nonlinear, time dependent initial value problem. Next, a computer program that solves these equations for one, two or more cavities, with and without externally driven fields, is described and some simulations of the harmonic cavity interaction are shown. Finally, the fully nonlinear equations are linearized to derive a dispersion relation for the case of beam excitation in the harmonic cavity. 6 refs., 5 figs

The Green's matrix and the boundary integral equations for analysis of time-harmonic dynamics of elastic helical springs.

Science.gov (United States)

Sorokin, Sergey V

2011-03-01

Helical springs serve as vibration isolators in virtually any suspension system. Various exact and approximate methods may be employed to determine the eigenfrequencies of vibrations of these structural elements and their dynamic transfer functions. The method of boundary integral equations is a meaningful alternative to obtain exact solutions of problems of the time-harmonic dynamics of elastic springs in the framework of Bernoulli-Euler beam theory. In this paper, the derivations of the Green's matrix, of the Somigliana's identities, and of the boundary integral equations are presented. The vibrational power transmission in an infinitely long spring is analyzed by means of the Green's matrix. The eigenfrequencies and the dynamic transfer functions are found by solving the boundary integral equations. In the course of analysis, the essential features and advantages of the method of boundary integral equations are highlighted. The reported analytical results may be used to study the time-harmonic motion in any wave guide governed by a system of linear differential equations in a single spatial coordinate along its axis. © 2011 Acoustical Society of America

Pitch Discrimination Learning: Specificity for Pitch and Harmonic Resolvability, and Electrophysiological Correlates

OpenAIRE

Carcagno, Samuele; Plack, Christopher J.

2011-01-01

Multiple-hour training on a pitch discrimination task dramatically decreases the threshold for detecting a pitch difference between two harmonic complexes. Here, we investigated the specificity of this perceptual learning with respect to the pitch and the resolvability of the trained harmonic complex, as well as its cortical electrophysiological correlates. We trained 24 participants for 12 h on a pitch discrimination task using one of four different harmonic complexes. The complexes differed...

Optimization of high harmonic generation by genetic algorithm

International Nuclear Information System (INIS)

Constance Valentin; Olga Boyko; Gilles Rey; Brigitte Mercier; Evaggelos Papalazarou; Laure Antonucci; Philippe Balcou

2006-01-01

Complete test of publication follows. High Harmonic Generation (HHG) is very sensitive to pulse shape of the fundamental laser. We have first used an Acousto-Optic Programmable Dispersive Filter (AOPDF) in order to modify the spectral phase and second, a deformable mirror in order to modify the wavefront. We have optimized harmonic signal using a genetic algorithm coupled with both setups. We show the influence of macroscopic parameters for optimization process. Genetic algorithms have been already used to modify pulse shapes of the fundamental laser in order to optimize high harmonic signals, in order to change the emission wavelength of one harmonic or to modify the fundamental wavefront to optimize harmonic signals. For the first time, we present a systematic study of the optimization of harmonic signals using the AOPDF. Signal optimizations by a factor 2 to 10 have been measured depending of parameters of generation. For instance, one of the interesting result concerns the effect of macroscopic parameters as position of the entrance of the cell with respect to the focus of the IR laser when we change the pulse shapes. For instance, the optimization is higher when the cell entrance is above the focus where the intensity gradients are higher. Although the spectral phase of the IR laser is important for the response of one atom, the optimization depends also of phase-matching and especially of the effect intensity gradients. Other systematic studies have been performed as well as measurements of temporal profiles and wavefronts of the IR beam. These studies allow bringing out the behaviour of high harmonic generation with respect to the optimization process.

Semiempirical formulas for single-particle energies of neutrons and protons

International Nuclear Information System (INIS)

Lodhi, M.A.K.; Waak, B.T.

1978-01-01

The stepwise multiple linear regression technique has been used to analyze the single-particle energies of neutrons and protons in nuclei along the line of beta stability. Their regular and systematic trends lead to semiempirical model-independent formulas for single-particle energies of neutrons and protons in the bound nuclei as functions of nuclear parameters A and Z for given states specified by nl/sub j/. These formulas are almost as convenient as the harmonic oscillator energy formulas to use. The single-particle energies computed from these formulas have been compared with the experimental data and are found in reasonable agreement

Means of Harmonization in Religious Discourse

Directory of Open Access Journals (Sweden)

Irina Ščukina

2012-12-01

Full Text Available Means of harmonization of religious discourse are considered by studying communicational behaviour (verbal and nonverbal between the religion institution and believers. The following factors defining specificity of realization of harmonization in Orthodox and other religious texts are taken into account: the communication channel between the author and the reader, a defining speech genre, the command of language (communication code, and extra-linguistic factors. It is shown that sharing the general social, historical and national experience, as well as a lexical overlapping of actors on both sides of the communication channel are the deciding elements of the harmonization process. The analysis also shows that usage of rational argumentation is more likely to lead to harmonisation in comparison to other rhetoric tools (i. e. affective ones or story-telling. Rational and unemotional sermonic discourse is perceived as a sign of respect (namely, for the listener's intelligence. Another successful and much-applied way seems to be evoking a feeling of equality, unity and/or identity between clerics and their flocks.

A Framework to Analyze the Stochastic Harmonics and Resonance of Wind Energy Grid Interconnection

Directory of Open Access Journals (Sweden)

Youngho Cho

2016-08-01

Full Text Available This paper addresses a modeling and analysis methodology for investigating the stochastic harmonics and resonance concerns of wind power plants (WPPs. Wideband harmonics from modern wind turbines (WTs are observed to be stochastic, associated with real power production, and they may adversely interact with the grid impedance and cause unexpected harmonic resonance, if not comprehensively addressed in the planning and commissioning of the WPPs. These issues should become more critical as wind penetration levels increase. We thus propose a planning study framework comprising the following functional steps: First, the best fitted probability density functions (PDFs of the harmonic components of interest in the frequency domain are determined. In operations planning, maximum likelihood estimations (MLEs followed by a chi-square test are used once field measurements or manufacturers’ data are available. Second, harmonic currents from the WPP are represented by randomly-generating harmonic components based on their PDFs (frequency spectrum and then synthesized for time domain simulations via inverse Fourier transform. Finally, we conduct a comprehensive assessment by including the impacts of feeder configurations, harmonic filters and the variability of parameters. We demonstrate the efficacy of the proposed study approach for a 100-MW offshore WPP consisting of 20 units of 5-MW full converter turbines, a realistic benchmark system adapted from a WPP under development in Korea and discuss lessons learned through this research.

Regulatory harmonization of the Saskatchewan uranium mines

International Nuclear Information System (INIS)

Forbes, R.; Moulding, T.; Alderman, G.

2006-01-01

The uranium mining industry in Saskatchewan produces approximately 30% of the world's production of uranium. The industry is regulated by federal and provincial regulators. The Canadian Nuclear Safety Commission is the principal federal regulator. The principal Saskatchewan provincial regulators are Saskatchewan Environment for provincial environmental regulations and Saskatchewan Labour for occupational health and safety regulations. In the past, mine and mill operators have requested harmonization in areas such as inspections and reporting requirements from the regulators. On February 14, 2003, Saskatchewan Environment, Saskatchewan Labour and the Canadian Nuclear Safety Commission signed a historical agreement for federal/provincial co-operation called the Canadian Nuclear Safety Commission - Saskatchewan Administrative Agreement for the Regulation of Health, Safety and the Environment at Saskatchewan Uranium Mines and Mills. This initiative responds to a recommendation made by the Joint Federal-Provincial Panel on Uranium Mining Developments in Northern Saskatchewan in 1997 and lays the groundwork to co-ordinate and harmonize their respective regulatory regimes. The implementation of the Agreement has been very successful. This paper will address the content of the Agreement including the commitments, the deliverables and the expectations for a harmonized compliance program, harmonized reporting, and the review of harmonized assessment and licensing processes as well as possible referencing of Saskatchewan Environment and Saskatchewan Labour regulations in the Nuclear Safety and Control Act. The management and implementation process will also be discussed including the schedule, stakeholder communication, the results to date and the lessons learned. (author)

The harmonization of banking legislation in the EU

Directory of Open Access Journals (Sweden)

Shkëlqesa Çitaku

2016-03-01

Full Text Available This paper attempts to assess the current legislation of banking in the European Union. The process of unification in Europe is also followed by efforts to harmonize and unify the laws of the member states. In the field of banking industry the precondition for harmonization of laws is the integration of internal market with the free movement of capital. The regulation and supervision of banks in EU still remains fragmented. European member states still have diverse regulations concerning the role of the state. The European Commission has the important function of proposing EU legislation on financial services including banks and ensuring that EU law is properly applied throughout the EU. Banks are considered as a key industry enabling all the economic activities via depositing, crediting and arranging of payments. A number of secondary legislation has been adopted by the EU institutions to harmonize the national banking law of Member States. The principles and objectives set by the European Commission Treaty depend on four EU freedoms with the aim of effective and open market including banks. Therefore it was a continuous process of harmonization of national banking regulation via secondary law since the 70’s.

Reducing workpieces to their base geometry for multi-step incremental forming using manifold harmonics

Science.gov (United States)

Carette, Yannick; Vanhove, Hans; Duflou, Joost

2018-05-01

Single Point Incremental Forming is a flexible process that is well-suited for small batch production and rapid prototyping of complex sheet metal parts. The distributed nature of the deformation process and the unsupported sheet imply that controlling the final accuracy of the workpiece is challenging. To improve the process limits and the accuracy of SPIF, the use of multiple forming passes has been proposed and discussed by a number of authors. Most methods use multiple intermediate models, where the previous one is strictly smaller than the next one, while gradually increasing the workpieces' wall angles. Another method that can be used is the manufacture of a smoothed-out "base geometry" in the first pass, after which more detailed features can be added in subsequent passes. In both methods, the selection of these intermediate shapes is freely decided by the user. However, their practical implementation in the production of complex freeform parts is not straightforward. The original CAD model can be manually adjusted or completely new CAD models can be created. This paper discusses an automatic method that is able to extract the base geometry from a full STL-based CAD model in an analytical way. Harmonic decomposition is used to express the final geometry as the sum of individual surface harmonics. It is then possible to filter these harmonic contributions to obtain a new CAD model with a desired level of geometric detail. This paper explains the technique and its implementation, as well as its use in the automatic generation of multi-step geometries.

Comparison study among conventional, tissue harmonic and pulse inversion harmonic images to evaluate pleural effusion and ascites

International Nuclear Information System (INIS)

Chung, Hwan Hoon; Kim, Yun Hwan; Kang, Chang Ho; Park, Bum Jin; Chung, Kyoo Byung; Suh, Won Hyuck

2000-01-01

To determine the most useful sonographic technique to evaluate pleural effusion and ascites by comparing conventional, tissue harmonic and pulse inversion harmonic images. 12 patients having pleural effusion and 14 patients having ascites were included in this study. 18 patients were male and 8 patients were female. Average age was 54.8 yrs (25-77). We compared images which had been taken at the same section with 3 above mentioned sonographic techniques. Evaluation was done by 3 radiologists in consensus and grades were given to 3 techniques from 1 to 3. Evaluating points were 1) normal structures that border the fluid such as liver, peritoneal lining, pleura, 2) septation in fluid, 3) debris floating in fluid, and 4) artifacts. Pulse inversion harmonic image was the best in image quality for normal structures, followed by tissue harmonic and conventional image (p<0.05). Pulse inversion harmonic image was better than conventional image to evaluate septation in fluid (p<0.05), but there were no statistically significant difference between pulse inversion and tissue harmonic images, and tissue harmonic and conventional images. Tissue harmonic image was better than pulse inversion harmonic and conventional images to evaluate debris floating in fluid (p<0.05) but there was no statistically significant difference between these two latter techniques. Artifacts were most prominent on conventional image followed by tissue harmonic and pulse inversion harmonic image (p<0.05). Pulse inversion harmonic image was the best sonographic technique to evaluate pleural effusion or ascites, However, Tissue harmonic image was the best for evaluation of debris.

Comparison study among conventional, tissue harmonic and pulse inversion harmonic images to evaluate pleural effusion and ascites

Energy Technology Data Exchange (ETDEWEB)

Chung, Hwan Hoon; Kim, Yun Hwan; Kang, Chang Ho; Park, Bum Jin; Chung, Kyoo Byung; Suh, Won Hyuck [Korea University College of Medicine, Seoul (Korea, Republic of)

2000-12-15

To determine the most useful sonographic technique to evaluate pleural effusion and ascites by comparing conventional, tissue harmonic and pulse inversion harmonic images. 12 patients having pleural effusion and 14 patients having ascites were included in this study. 18 patients were male and 8 patients were female. Average age was 54.8 yrs (25-77). We compared images which had been taken at the same section with 3 above mentioned sonographic techniques. Evaluation was done by 3 radiologists in consensus and grades were given to 3 techniques from 1 to 3. Evaluating points were 1) normal structures that border the fluid such as liver, peritoneal lining, pleura, 2) septation in fluid, 3) debris floating in fluid, and 4) artifacts. Pulse inversion harmonic image was the best in image quality for normal structures, followed by tissue harmonic and conventional image (p<0.05). Pulse inversion harmonic image was better than conventional image to evaluate septation in fluid (p<0.05), but there were no statistically significant difference between pulse inversion and tissue harmonic images, and tissue harmonic and conventional images. Tissue harmonic image was better than pulse inversion harmonic and conventional images to evaluate debris floating in fluid (p<0.05) but there was no statistically significant difference between these two latter techniques. Artifacts were most prominent on conventional image followed by tissue harmonic and pulse inversion harmonic image (p<0.05). Pulse inversion harmonic image was the best sonographic technique to evaluate pleural effusion or ascites, However, Tissue harmonic image was the best for evaluation of debris.

FERMI @ Elettra A Seeded Harmonic Cascade FEL for EUV and Soft X-Rays

CERN Document Server

Bocchetta, C J; Craievich, P; D'Auria, G; Danailov, M B; De Ninno, G; Di Mitri, S; Diviacco, B; Ferianis, M; Gomezel, A; Iazzourene, F; Karantzoulis, E; Penco, G; Trovò, M

2005-01-01

We describe the machine layout and major performance parameters for the FERMI FEL project funded for construction at Sincrotrone Trieste, Italy. The project will be the first user facility based on seeded harmonic cascade FELs, providing controlled, high peak-power pulses. With a high-brightness rf photocathode gun, and using the existing 1.2 GeV S-band linac, the facility will provide tunable output over a range from ~100 nm to ~10 nm, with pulse duration from 40 fs to ~ 1ps, and with fully variable output polarization. Initially, two FEL cascades are planned; a single-stage harmonic generation to operate > 40 nm, and a two-stage cascade operating from ~40 nm to ~10 nm or shorter wavelength. The output is spatially and temporally coherent, with peak power in the GW range. Lasers provide modulation to the electron beam, as well as driving the photocathode and other systems, and the facility will integrate laser systems with the accelerator infrastructure, including a state-of-the-art optical timing sys...

Two dimensional kinetic analysis of electrostatic harmonic plasma waves

Energy Technology Data Exchange (ETDEWEB)

Fonseca-Pongutá, E. C.; Ziebell, L. F.; Gaelzer, R. [Instituto de Física, UFRGS, 91501-970 Porto Alegre, RS (Brazil); Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); SSR, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of)

2016-06-15

Electrostatic harmonic Langmuir waves are virtual modes excited in weakly turbulent plasmas, first observed in early laboratory beam-plasma experiments as well as in rocket-borne active experiments in space. However, their unequivocal presence was confirmed through computer simulated experiments and subsequently theoretically explained. The peculiarity of harmonic Langmuir waves is that while their existence requires nonlinear response, their excitation mechanism and subsequent early time evolution are governed by essentially linear process. One of the unresolved theoretical issues regards the role of nonlinear wave-particle interaction process over longer evolution time period. Another outstanding issue is that existing theories for these modes are limited to one-dimensional space. The present paper carries out two dimensional theoretical analysis of fundamental and (first) harmonic Langmuir waves for the first time. The result shows that harmonic Langmuir wave is essentially governed by (quasi)linear process and that nonlinear wave-particle interaction plays no significant role in the time evolution of the wave spectrum. The numerical solutions of the two-dimensional wave spectra for fundamental and harmonic Langmuir waves are also found to be consistent with those obtained by direct particle-in-cell simulation method reported in the literature.

The Two-Capacitor Problem Revisited: A Mechanical Harmonic Oscillator Model Approach

Science.gov (United States)

Lee, Keeyung

2009-01-01

The well-known two-capacitor problem, in which exactly half the stored energy disappears when a charged capacitor is connected to an identical capacitor, is discussed based on the mechanical harmonic oscillator model approach. In the mechanical harmonic oscillator model, it is shown first that "exactly half" the work done by a constant applied…

Mean species cover: a harmonized indicator of shrub cover for forest inventories

Science.gov (United States)

Iciar Alberdi; Sonia Condés; Ronald E. Mcroberts; Susanne Winter

2018-01-01

Because shrub cover is related to many forest ecosystem functions, it is one of the most relevant variables for describing these communities. Nevertheless, a harmonized indicator of shrub cover for large-scale reporting is lacking. The aims of the study were threefold: to define a shrub indicator that can be used by European countries for harmonized shrub cover...

Single-Phase Single-Stage Grid Tied Solar PV System with Active Power Filtering Using Power Balance Theory

Science.gov (United States)

Singh, Yashi; Hussain, Ikhlaq; Singh, Bhim; Mishra, Sukumar

2018-03-01

In this paper, power quality features such as harmonics mitigation, power factor correction with active power filtering are addressed in a single-stage, single-phase solar photovoltaic (PV) grid tied system. The Power Balance Theory (PBT) with perturb and observe based maximum power point tracking algorithm is proposed for the mitigation of power quality problems in a solar PV grid tied system. The solar PV array is interfaced to a single phase AC grid through a Voltage Source Converter (VSC), which provides active power flow from a solar PV array to the grid as well as to the load and it performs harmonics mitigation using PBT based control. The solar PV array power varies with sunlight and due to this, the solar PV grid tied VSC works only 8-10 h per day. At night, when PV power is zero, the VSC works as an active power filter for power quality improvement, and the load active power is delivered by the grid to the load connected at the point of common coupling. This increases the effective utilization of a VSC. The system is modelled and simulated using MATLAB and simulated responses of the system at nonlinear loads and varying environmental conditions are also validated experimentally on a prototype developed in the laboratory.

International standards for financial reporting: Harmonization in Macedonia

OpenAIRE

Kozuharov, Sasho; Ristovska, Natasha; Blazeska, Daliborka

2015-01-01

A continuous flow of reliable, relevant and financially important information is necessary for making economically justified and strategic investment decisions. Economic globalization has contributed to the need of creating a unified language for communication, a single set of international financial reporting standards with the sole purpose of enhancing transparency for investors and reducing the cost of capital. Harmonization of financial reporting provides more efficient use of...

Harmonic Active Filtering and Impedance-based Stability Analysis in Offshore Wind Power Plants

DEFF Research Database (Denmark)

Dhua, Debasish; Yang, Guangya; Zhang, Zhe

2017-01-01

installation and provides effectively similar functionality as passive filters. This work is focused on harmonic propagation studies in wind power plants, power quality evaluation at the point of connection and harmonic mitigation by active filtering. Finally, an impedance-based stability analysis......Nowadays, to eliminate harmonics injected by the wind turbines in offshore wind power plants there is a need to install passive filters. Moreover, the passive filters are not adaptive to harmonic profile changes due to topology changes, grid loading etc. Therefore, active filters in wind turbines...... are proposed as a flexible harmonic mitigation measure. The motivation of this study is to explore the possibility of embedding active filtering in wind turbine grid-side converters without having to change the system electrical infrastructure. The active filtering method can prevent additional equipment...

Harmonic Domain Modelling of Transformer Core Nonlinearities Using the DIgSILENT PowerFactory Software

DEFF Research Database (Denmark)

Bak, Claus Leth; Bak-Jensen, Birgitte; Wiechowski, Wojciech

2008-01-01

This paper demonstrates the results of implementation and verification of an already existing algorithm that allows for calculating saturation characteristics of singlephase power transformers. The algorithm was described for the first time in 1993. Now this algorithm has been implemented using...... the DIgSILENT Programming Language (DPL) as an external script in the harmonic domain calculations of a power system analysis tool PowerFactory [10]. The algorithm is verified by harmonic measurements on a single-phase power transformer. A theoretical analysis of the core nonlinearities phenomena...... in single and three-phase transformers is also presented. This analysis leads to the conclusion that the method can be applied for modelling nonlinearities of three-phase autotransformers....

The space of harmonic maps of S2 into S4

International Nuclear Information System (INIS)

Loo, B.

1989-05-01

Every branched superminimal surface of area 4πd in S 4 is shown to arise from a pair of meromorphic functions (f 1 ,f 2 ) of bidegree (d,d) such that f 1 and f 2 have the same ramification divisor. Conditions under which branched superminimal surfaces can be generated from such pairs of functions are derived. For each d ≥ 1 the space of harmonic maps (i.e branched superminimal immersions) of S 2 into S 4 of harmonic degree d is shown to be a connected space of complex dimension 2d+4. (author). 18 refs

Single and multiple transverse fracture initiation from horizontal wells

Energy Technology Data Exchange (ETDEWEB)

Crosby, D.G.; Rahman, M.M.; Rahman, M.K.; Rahman, S.S. [School of Petroleum Engineering, The University of New South Wales, 2052 Sydney (Australia)

2002-08-01

The results of an analytical and experimental study of the initiation of transverse fractures from horizontal wells are presented. Analytical criteria for the initiation of single hydraulic fracture are reviewed, and criterion for initiation of multiple hydraulic fractures was developed by modification of the existing Drucker and Prager criterion for single hydraulic fracture initiation. The developed criterion for multiple fracture initiation was validated by comparisons with actual hydraulic fracture initiation pressures, which were obtained from scaled laboratory experiments and numerical results from boundary element analysis. Other criteria are assessed against the experimental results. Experimentally obtained transverse fracture initiation pressures were found close to longitudinal fracture initiation pressures estimated from maximum tensile stress criterion and Hoek and Brown criterion. One possible explanation of this finding is presented. Results from Drucker and Prager criteria for single and multiple fracture initiation were, however, found closer to experimental values. Therefore, these criteria could be useful to engineers involved with hydraulic fracturing for predicting transverse fracture initiation pressures from horizontal wells drilled parallel to the minimum horizontal in-situ stress.

Properties of Floquet-Bloch space harmonics in 1D periodic magneto-dielectric structures

DEFF Research Database (Denmark)

Breinbjerg, O.

2012-01-01

Recent years have witnessed a significant research interest in Floquet-Bloch analysis for determining the homogenized permittivity and permeability of metamaterials consisting of periodic structures. This work investigates fundamental properties of the Floquet-Bloch space harmonics in a 1......-dimensional magneto-dielectric lossless structure supporting a transverse-electric-magnetic Floquet-Bloch wave; in particular, the space harmonic permittivity and permeability, as well as the space harmonic Poynting vector....

On how differently the quasi-harmonic approximation works for two isostructural crystals: Thermal properties of periclase and lime

International Nuclear Information System (INIS)

Erba, A.; Dovesi, R.; Shahrokhi, M.; Moradian, R.

2015-01-01

Harmonic and quasi-harmonic thermal properties of two isostructural simple oxides (periclase, MgO, and lime, CaO) are computed with ab initio periodic simulations based on the density-functional-theory (DFT). The more polarizable character of calcium with respect to magnesium cations is found to dramatically affect the validity domain of the quasi-harmonic approximation that, for thermal structural properties (such as temperature dependence of volume, V(T), bulk modulus, K(T), and thermal expansion coefficient, α(T)), reduces from [0 K-1000 K] for MgO to just [0 K-100 K] for CaO. On the contrary, thermodynamic properties (such as entropy, S(T), and constant-volume specific heat, C V (T)) are described reliably at least up to 2000 K and quasi-harmonic constant-pressure specific heat, C P (T), up to about 1000 K in both cases. The effect of the adopted approximation to the exchange-correlation functional of the DFT is here explicitly investigated by considering five different expressions of three different classes (local-density approximation, generalized-gradient approximation, and hybrids). Computed harmonic thermodynamic properties are found to be almost independent of the adopted functional, whereas quasi-harmonic structural properties are more affected by the choice of the functional, with differences that increase as the system becomes softer

Can even-order laser harmonics exhibited by Bohmian trajectories in symmetric potentials be observed?

Science.gov (United States)

Peatross, J; Johansen, J

2014-01-13

Strong-field laser-atom interactions provide extreme conditions that may be useful for investigating the de Broglie-Bohm quantum interpretation. Bohmian trajectories representing bound electrons in individual atoms exhibit both even and odd harmonic motion when subjected to a strong external laser field. The phases of the even harmonics depend on the random initial positions of the trajectories within the wave function, making the even harmonics incoherent. In contrast, the phases of odd harmonics remain for the most part coherent regardless of initial position. Under the conjecture that a Bohmian point particle plays the role of emitter, this suggests an experiment to determine whether both even and odd harmonics are produced at the atomic level. Estimates suggest that incoherent emission of even harmonics may be detectable out the side of an intense laser focus interacting with a large number of atoms.

A New Control Structure for Grid-Connected LCL PV Inverters with Zero Steady-State Error and Selective Harmonic Compensation

DEFF Research Database (Denmark)

Teodorescu, Remus; Blaabjerg, Frede; Borup, Uffe

2004-01-01

disturbance rejection capability leads to the need of grid feed-forward compensation. However the imperfect compensation action of the feed-forward control results in high harmonic distortion of the current and consequently non-compliance with international standards. In this paper a new control strategy...... aimed to mitigate these problems is proposed. Stationary-frame generalized integrators are used to control the fundamental current and to compensate the grid harmonics providing disturbance rejection capability without the need of feed-forward grid compensation. Moreover the use of a grid LCL......The PI current control of a single-phase inverter has well known drawbacks: steady-state magnitude and phase-error and limited disturbance rejection capability. When the current controlled inverter is connected to the grid, the phase error results in a power factor decrement and the limited...

Harmonic mitigation in islanded microgrids by inverter-interfaced distributed energy resource

Energy Technology Data Exchange (ETDEWEB)

Xiongfei Wang

2012-10-15

primary droop controllers integrated with virtual output impedance loops and the secondary controllers enabled by the low-bandwidth communication. With the chosen control options of DER inverters, the circulating current characteristics in the droop-controlled parallel three-phase DER inverters are analysed. It is found that the circulating current not only consists of the Positive-Sequence Circulating Current (PSCC) but also contains the Negative-Sequence Circulating Current (NSCC) even when feeding linear balanced loads. It is shown that the presence of the NSCC deteriorates the current quality of inverters and results in unbalanced voltage distortion at certain buses of an islanded microgrid. In order to reduce the NSCC, an improved virtual output impedance loop is proposed, where a negative-sequence virtual resistance is introduced based on the detection of the negative-sequence output current. Moreover, to adapt to the variation of unbalanced loads, a dynamically-tuned negative-sequence resistance is developed. Thus, an autonomous NSCC control that is more suitable for the scattered DER units is achieved and validated via a series of laboratory tests. Under the built islanded microgrid, the control methods of DER inverters for active harmonic conditioning are investigated. Two autonomous harmonic current filtering and resonance damping approaches, i.e. the Resistive-Active Power Filter (R-APF)-based method and the virtual output resistance scheme, are evaluated. It has been found that the large grid-side inductances of DER inverters may lead to either underdamped or aggravated harmonic voltages in the islanded microgrid. To address such a challenge, a Variable Harmonic Impedance (VHI) concept is proposed, where positive resistances and negative inductances are synthesized at the dominant harmonic frequencies. Two case studies, including the single grid-interactive DER inverter and the parallel DER inverters, are carried out. Simulation and laboratory test results are

The Harmonic Potential Theorem for a Quantum System with Time-Dependent Effective Mass

International Nuclear Information System (INIS)

Lai Meng-Yun; Xiao Duan-Liang; Pan Xiao-Yin

2015-01-01

We investigate the many-body wave function of a quantum system with time-dependent effective mass, confined by a harmonic potential with time-dependent frequency, and perturbed by a time-dependent spatially homogeneous electric field. It is found that the wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schrödinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the harmonic potential theorem wave function when both the effective mass and frequency are static. An example of application is also given. (paper)

Harmonic Patterns in Forex Trading

OpenAIRE

Nemček, Sebastian

2013-01-01

This diploma thesis is committed to examination of validity of Harmonic Patterns in Forex trading. Scott Carney described existing and introduced new Harmonic Patterns in 1999 in his book Harmonic Trader. These patterns use the Fibonacci principle to analyze price action and to provide both bullish and bearish trading signals. The goal of this thesis is to find out whether harmonic trading strategy on selected pairs is profitable in FX market, which patterns are the most profitable and what i...

Coherence properties of the harmonic generation in intense laser field

International Nuclear Information System (INIS)

Salieres, P.

1995-01-01

In this thesis is presented an experimental and theoretical study of the harmonic generation in intense field and coherence properties of this radiation. The first part reminds the main harmonic specter characteristics. Follow then experimental studies of the tray extension with the laser lighting, the harmonic generation by ions, and the influence of the laser field on the efficiency of generation. The second part presents the quantum model of the harmonic generation in tunnel regime that we have used for the calculation of the dipoles. We compare dependence in lighting of some harmonic, by insisting on the characteristic behavior of the atomic phase. The theory of the propagation is presented in third part. After the reminder of the case of a perturbative polarization, we develop the case of the polarization in tunnel regime. With the help of numerical simulations, we show the influence of the atomic phase on the agreement of phase, and therefore on the efficiency of conversion and profiles of generation in the medium. The importance of the geometry of the interaction is underlined. The part IV presents the study of the spatial coherence of the harmonic radiation. We develop first consequences of the theory of the agreement of phase for profiles of emission. Then the comparison with experimental profiles is detailed in function of the different parameters( order of non linearity, laser lighting, position of the focus by report in the gaseous medium). The study of the spectral and temporal coherence of the part V begins with the experimental effect investigation of the ionization on specters of the harmonic of weak order. We present then theoretical predictions of the preceding model for spectral and temporal profiles of the harmonic of highest order, generated in tunnel regime. The part VI is devoted to the UVX source aspect of the harmonic radiation. General characteristics (number of photons, agreement) are first detailed, then we present the first experiences

Recent Developments in Real and Harmonic Analysis In Honor of Carlos Segovia

CERN Document Server

Cabrelli, Carlos A

2008-01-01

Featuring a collection of invited chapters dedicated to Carlos Segovia, this volume examines the developments in real and harmonic analysis. It includes topics such as: Vector-valued singular integral equations; Harmonic analysis related to Hermite expansions; Gas flow in porous media; and, Global well-posedness of the KPI Equation

General well function for soil vapor extraction

Science.gov (United States)

Perina, Tomas

2014-04-01

This paper develops a well function applicable to extraction of groundwater or soil vapor from a well under the most common field test conditions. The general well function (Perina and Lee, 2006) [12] is adapted to soil vapor extraction and constant head boundary at the top. For groundwater flow, the general well function now applies to an extraction well of finite diameter with uniform drawdown along the screen, finite-thickness skin, and partially penetrating an unconfined, confined, and leaky aquifer, or an aquifer underneath a reservoir. With a change of arguments, the model applies to soil vapor extraction from a vadose zone with no cover or with leaky cover at the ground surface. The extraction well can operate in specified drawdown (pressure for soil vapor) or specified flowrate mode. Frictional well loss is computed as flow-only dependent component of the drawdown inside the extraction well. In general case, the calculated flow distribution is not proportional to screen length for a multiscreen well.

Spatio-spectral analysis of ionization times in high-harmonic generation

Energy Technology Data Exchange (ETDEWEB)

Soifer, Hadas, E-mail: hadas.soifer@weizmann.ac.il [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel); Dagan, Michal; Shafir, Dror; Bruner, Barry D. [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel); Ivanov, Misha Yu. [Department of Physics, Imperial College London, South Kensington Campus, SW7 2AZ London (United Kingdom); Max-Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Strasse 2A, D-12489 Berlin (Germany); Serbinenko, Valeria; Barth, Ingo; Smirnova, Olga [Max-Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Strasse 2A, D-12489 Berlin (Germany); Dudovich, Nirit [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel)

2013-03-12

Graphical abstract: A spatio-spectral analysis of the two-color oscillation phase allows us to accurately separate short and long trajectories and reconstruct their ionization times. Highlights: ► We perform a complete spatio-spectral analysis of the high harmonic generation process. ► We analyze the ionization times across the entire spatio-spectral plane of the harmonics. ► We apply this analysis to reconstruct the ionization times of both short and long trajectories. - Abstract: Recollision experiments have been very successful in resolving attosecond scale dynamics. However, such schemes rely on the single atom response, neglecting the macroscopic properties of the interaction and the effects of using multi-cycle laser fields. In this paper we perform a complete spatio-spectral analysis of the high harmonic generation process and resolve the distribution of the subcycle dynamics of the recolliding electron. Specifically, we focus on the measurement of ionization times. Recently, we have demonstrated that the addition of a weak, crossed polarized second harmonic field allows us to resolve the moment of ionization (Shafir, 2012) [1]. In this paper we extend this measurement and perform a complete spatio-spectral analysis. We apply this analysis to reconstruct the ionization times of both short and long trajectories showing good agreement with the quantum path analysis.

Targeting a single function of the multifunctional matrix metalloprotease MT1-MMP

DEFF Research Database (Denmark)

Ingvarsen, Signe; Porse, Astrid; Erpicum, Charlotte

2013-01-01

and pathological events, has been complicated by the lack of specific inhibitors and the fact that some of the potent MMPs are multifunctional enzymes. These factors have also hampered the setup of therapeutic strategies targeting MMP activity. A tempting target is the membrane-associated MT1-MMP, which has well......-documented importance in matrix degradation but which takes part in more than one pathway in this regard. In this report, we describe the selective targeting of a single function of this enzyme by means of a specific monoclonal antibody against MT1-MMP, raised in an MT1-MMP knock-out mouse. The antibody blocks...... matrix in vitro, as well as in lymphatic vessel sprouting assayed ex vivo. This is the first example of the complete inactivation of a single function of a multifunctional MMP and the use of this strategy to pursue its role....

A 43-level filterless CMLI with very low harmonics values

Directory of Open Access Journals (Sweden)

Mahmoud El-Bakry

2014-12-01

Full Text Available This paper introduces a 43-level asymmetric uniform step cascaded multilevel inverter (CMLI that consists of four H-bridges per phase, with different dc sources of values E, 2E, 7E and 11E. A mixed integer linear programming (MILP optimization model is applied to determine the switching angles of the CMLI power switches that can minimize the values of any undesired harmonics. Single phase and three phase cases are considered. The results show very low values of all the undesired harmonics over wide voltage ranges, which agree with the IEEE standards 519-1992 for voltage distortion limits for both the values of %THDE and %VHmax so that no output filters are needed.

Digital model for harmonic interactions in AC/DC/AC systems

Energy Technology Data Exchange (ETDEWEB)

Guarini, A P; Rangel, R D; Pilotto, L A.S.; Pinto, R J; Passos, Junior, R [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)

1994-12-31

The main purpose of this paper is to present a model for calculation of HVdc converter harmonics taking into account the influence of the harmonic interactions between the ac systems in dc link transmissions. The ideas and methodologies used in the model development take into account the dc current ripple and ac voltage distortion in the ac systems. The theory of switching functions is applied to contemplate for the frequency conversions between the ac and dc sides, in an iterative process. It is possible then to obtain, even in balanced situations, non-characteristic harmonics that are produced by frequencies originated in the other terminal, which can be significant in a strongly coupled system, such as back-to-back configuration. (author) 9 refs., 3 figs.

Synthesis of Variable Harmonic Impedance in Inverter-Interfaced Distributed Generation Unit for Harmonic Damping Throughout a Distribution Network

DEFF Research Database (Denmark)

Wang, Xiongfei; Blaabjerg, Frede; Chen, Zhe

2012-01-01

This paper proposes a harmonic impedance synthesis technique for voltage-controlled distributed generation inverters in order to damp harmonic voltage distortion on a distribution network. The approach employs a multiloop control scheme, where a selective harmonic load current feedforward loop...... at the dominant harmonic frequencies. Thus, the harmonic voltage drop on the grid-side inductance and the harmonic resonances throughout a distribution feeder with multiple shunt-connected capacitors can be effectively attenuated. Simulation and laboratory test results validate the performance of the proposed...

Investigation of the vibration spectrum of SbSI crystals in harmonic and in anharmonic approximations

International Nuclear Information System (INIS)

Audzijonis, A.; Zigas, L.; Vinokurova, I.V.; Farberovic, O.V.; Zaltauskas, R.; Cijauskas, E.; Pauliukas, A.; Kvedaravicius, A.

2006-01-01

The force constants of SbSI crystal have been calculated by the pseudo-potential method. The frequencies and normal coordinates of SbSI vibration modes along the c (z) direction have been determined in harmonic approximation. The potential energies of SbSI normal modes dependence on normal coordinates along the c (z) direction V(z) have been determined in anharmonic approximation, taking into account the interaction between the phonons. It has been found, that in the range of 30-120 cm -1 , the vibrational spectrum is determined by a V(z) double-well normal mode, but in the range of 120-350 cm -1 , it is determined by a V(z) single-well normal mode

Probing two-centre interference in molecular high harmonic generation

International Nuclear Information System (INIS)

Vozzi, C; Calegari, F; Benedetti, E; Berlasso, R; Sansone, G; Stagira, S; Nisoli, M; Altucci, C; Velotta, R; Torres, R; Heesel, E; Kajumba, N; Marangos, J P

2006-01-01

Two-centre interference in the recombination step of molecular high harmonic generation (HHG) has been probed in CO 2 and O 2 . We report the order dependence of characteristic enhancements or suppressions of high harmonic production in aligned samples of both molecules. In CO 2 , a robust destructive interference was seen consistent with the known separation of the oxygen atoms that are active in HHG. In O 2 , a harmonic enhancement was found indicating constructive interference. A good agreement was found with a simple two-centre interference model that includes the angular distribution function of the sample. The effective momentum of the electron wave was determined from the spectral position of these interferences. Ellipticity-dependent studies in CO 2 clearly show how the destructive interference can be 'switched off' by increasing the degree of ellipticity and thus shifting the effective resonance condition

Single well surfactant test to evaluate surfactant floods using multi tracer method

Science.gov (United States)

Sheely, Clyde Q.

1979-01-01

Data useful for evaluating the effectiveness of or designing an enhanced recovery process said process involving mobilizing and moving hydrocarbons through a hydrocarbon bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well, comprising (a) determining hydrocarbon saturation in a volume in the formation near a well bore penetrating formation, (b) injecting sufficient mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore, and (c) determining the hydrocarbon saturation in a volume including at least a part of the volume of (b) by an improved single well surfactant method comprising injecting 2 or more slugs of water containing the primary tracer separated by water slugs containing no primary tracer. Alternatively, the plurality of ester tracers can be injected in a single slug said tracers penetrating varying distances into the formation wherein the esters have different partition coefficients and essentially equal reaction times. The single well tracer method employed is disclosed in U.S. Pat. No. 3,623,842. This method designated the single well surfactant test (SWST) is useful for evaluating the effect of surfactant floods, polymer floods, carbon dioxide floods, micellar floods, caustic floods and the like in subterranean formations in much less time and at much reduced cost compared to conventional multiwell pilot tests.

Dynamics of injection locking in a solid-state laser with intracavity second-harmonic generation

International Nuclear Information System (INIS)

Zolotoverkh, I I; Lariontsev, E G

2000-01-01

The dynamics of oscillation in a solid-state laser with intracavity second-harmonic generation under the influence of an external signal at the second-harmonic frequency injected into its cavity in the presence of feedback at the double frequency is theoretically studied. Boundaries of the regions of injection locking for three stationary laser states differing in the nonlinear phase incursion caused by radiation conversion into the second harmonic are found. Relaxation oscillations in the stationary state of injection locking are studied. It is shown that the second relaxation frequency, which is related to phase perturbations of the second harmonic and perturbations of the phase difference of waves in a nonlinear crystal, is excited in a single-mode solid-state laser in addition to the fundamental frequency of relaxation oscillations. Conditions are found under which relaxation oscillations at the second relaxation frequency are excited. (lasers)

Pump-probe study of atoms and small molecules with laser driven high order harmonics

Science.gov (United States)

Cao, Wei

A commercially available modern laser can emit over 1015 photons within a time window of a few tens of femtoseconds (10-15second), which can be focused into a spot size of about 10 mum, resulting in a peak intensity above 1014W/cm2. This paves the way for table-top strong field physics studies such as above threshold ionization (ATI), non-sequential double ionization (NSDI), high order harmonic generation (HHG), etc.. Among these strong laser-matter interactions, high order harmonic generation, which combines many photons of the fundamental laser field into a single photon, offers a unique way to generate light sources in the vacuum ultraviolet (VUV) or extreme ultraviolet (EUV) region. High order harmonic photons are emitted within a short time window from a few tens of femtoseconds down to a few hundreds of attoseconds (10 -18second). This highly coherent nature of HHG allows it to be synchronized with an infrared (IR) laser pulse, and the pump-probe technique can be adopted to study ultrafast dynamic processes in a quantum system. The major work of this thesis is to develop a table-top VUV(EUV) light source based on HHG, and use it to study dynamic processes in atoms and small molecules with the VUV(EUV)-pump IR-probe method. A Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) apparatus is used for momentum imaging of the interaction products. Two types of high harmonic pump pulses are generated and applied for pump-probe studies. The first one consists of several harmonics forming a short attosecond pulse train (APT) in the EUV regime (around 40 eV). We demonstrate that, (1) the auto-ionization process triggered by the EUV in cation carbon-monoxide and oxygen molecules can be modified by scanning the EUV-IR delay, (2) the phase information of quantum trajectories in bifurcated high harmonics can be extracted by performing an EUV-IR cross-correlation experiment, thus disclosing the macroscopic quantum control in HHG. The second type of high harmonic source

Application of harmonic pulse testing to water-oil displacement

NARCIS (Netherlands)

Fokker, P.A.; Verga, F.

2011-01-01

Harmonic pulse testing is a well testing technique in which the injection or production rate is varied in a periodic way. The pressure response to the imposed rates, both in the pulser well and in the observer wells, can be analyzed in the frequency domain to evaluate the reservoir properties. The

Using harmonic oscillators to determine the spot size of Hermite-Gaussian laser beams

Science.gov (United States)

Steely, Sidney L.

1993-01-01

The similarity of the functional forms of quantum mechanical harmonic oscillators and the modes of Hermite-Gaussian laser beams is illustrated. This functional similarity provides a direct correlation to investigate the spot size of large-order mode Hermite-Gaussian laser beams. The classical limits of a corresponding two-dimensional harmonic oscillator provide a definition of the spot size of Hermite-Gaussian laser beams. The classical limits of the harmonic oscillator provide integration limits for the photon probability densities of the laser beam modes to determine the fraction of photons detected therein. Mathematica is used to integrate the probability densities for large-order beam modes and to illustrate the functional similarities. The probabilities of detecting photons within the classical limits of Hermite-Gaussian laser beams asymptotically approach unity in the limit of large-order modes, in agreement with the Correspondence Principle. The classical limits for large-order modes include all of the nodes for Hermite Gaussian laser beams; Sturm's theorem provides a direct proof.

Tissue Harmonic Synthetic Aperture Imaging

DEFF Research Database (Denmark)

Rasmussen, Joachim

The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB...

On the asymptotically Poincaré-Einstein 4-manifolds with harmonic curvature

Science.gov (United States)

Hu, Xue

2018-06-01

In this paper, we discuss the mass aspect tensor and the rigidity of an asymptotically Poincaré-Einstein (APE) 4-manifold with harmonic curvature. We prove that the trace-free part of the mass aspect tensor of an APE 4-manifold with harmonic curvature and normalized Einstein conformal infinity is zero. As to the rigidity, we first show that a complete noncompact Riemannian 4-manifold with harmonic curvature and positive Yamabe constant as well as a L2-pinching condition is Einstein. As an application, we then obtain that an APE 4-manifold with harmonic curvature and positive Yamabe constant is isometric to the hyperbolic space provided that the L2-norm of the traceless Ricci tensor or the Weyl tensor is small enough and the conformal infinity is a standard round 3-sphere.

Efficient and tunable high-order harmonic light sources for photoelectron spectroscopy at surfaces

International Nuclear Information System (INIS)

Chiang, Cheng-Tien; Huth, Michael; Trützschler, Andreas; Schumann, Frank O.; Kirschner, Jürgen; Widdra, Wolf

2015-01-01

Highlights: • An overview of photoelectron spectroscopy using high-order harmonics is presented. • Photoemission spectra on Ag(0 0 1) using megahertz harmonics are shown. • A gas recycling system for harmonic generation is presented. • Non-stop operation of megahertz harmonics up to 76 h is demonstrated. • The bandwidth and pulse duration of the harmonics are discussed. - Abstract: With the recent progress in high-order harmonic generation (HHG) using femtosecond lasers, laboratory photoelectron spectroscopy with an ultrafast, widely tunable vacuum-ultraviolet light source has become available. Despite the well-established technique of HHG-based photoemission experiments at kilohertz repetition rates, the efficiency of these setups can be intrinsically limited by the space-charge effects. Here we present recent developments of compact HHG light sources for photoelectron spectroscopy at high repetition rates up to megahertz, and examples for angle-resolved photoemission experiments are demonstrated.

Generating transverse response explicitly from harmonic oscillators

Science.gov (United States)

Yao, Yuan; Tang, Ying; Ao, Ping

2017-10-01

We obtain stochastic dynamics from a system-plus-bath mechanism as an extension of the Caldeira-Leggett (CL) model in the classical regime. An effective magnetic field and response functions with both longitudinal and transverse parts are exactly generated from the bath of harmonic oscillators. The effective magnetic field and transverse response are antisymmetric matrices: the former is explicitly time-independent corresponding to the geometric magnetism, while the latter can have memory. The present model can be reduced to previous representative examples of stochastic dynamics describing nonequilibrium processes. Our results demonstrate that a system coupled with a bath of harmonic oscillators is a general approach to studying stochastic dynamics, and provides a method to experimentally implement an effective magnetic field from coupling to the environment.

On the conformal equivalence of harmonic maps and exponentially harmonic maps

International Nuclear Information System (INIS)

Hong Minchun.

1991-06-01

Suppose that (M,g) and (N,h) are compact smooth Riemannian manifolds without boundaries. For m = dim M ≥3, and Φ: (M,g) → (N,h) is exponentially harmonic, there exists a smooth metric g-tilde conformally equivalent to g such that Φ: (M,g-tilde) → (N,h) is harmonic. (author). 7 refs

Application of Vector Spherical Harmonics and Kernel Regression to the Computations of OMM Parameters

Science.gov (United States)

Marco, F. J.; Martínez, M. J.; López, J. A.

2015-04-01

The high quality of Hipparcos data in position, proper motion, and parallax has allowed for studies about stellar kinematics with the aim of achieving a better physical understanding of our galaxy, based on accurate calculus of the Ogorodnikov-Milne model (OMM) parameters. The use of discrete least squares is the most common adjustment method, but it may lead to errors mainly because of the inhomogeneous spatial distribution of the data. We present an example of the instability of this method using the case of a function given by a linear combination of Legendre polynomials. These polynomials are basic in the use of vector spherical harmonics, which have been used to compute the OMM parameters by several authors, such as Makarov & Murphy, Mignard & Klioner, and Vityazev & Tsvetkov. To overcome the former problem, we propose the use of a mixed method (see Marco et al.) that includes the extension of the functions of residuals to any point on the celestial sphere. The goal is to be able to work with continuous variables in the calculation of the coefficients of the vector spherical harmonic developments with stability and efficiency. We apply this mixed procedure to the study of the kinematics of the stars in our Galaxy, employing the Hipparcos velocity field data to obtain the OMM parameters. Previously, we tested the method by perturbing the Vectorial Spherical Harmonics model as well as the velocity vector field.

Regions of tunneling dynamics for few bosons in an optical lattice subjected to a quench of the imposed harmonic trap

Science.gov (United States)

Mistakidis, Simeon; Koutentakis, Georgios; Schmelcher, Peter; Theory Group of Fundamental Processes in Quantum Physics Team

2016-05-01

Recent experimental advances have introduced an interplay in the trapping length scales of the lattice and the harmonic confinement. This fact motivates the investigation to prepare atomic gases at certain quantum states by utilizing a composite atomic trap consisting of a lattice potential that is embedded inside an overlying harmonic trap. In the present work, we examine how frequency modulations of the overlying harmonic trap stimulate the dynamics of an 1D few-boson gas. The gas is initially prepared at a highly confined state, and the subsequent dynamics induced by a quench of the harmonic trap frequency to a lower value is examined. It is shown that a non-interacting gas always diffuses to the outer sites. In contrast the response of the interacting system is more involved and is dominated by a resonance, which is induced by the bifurcation of the low-lying eigenstates. Our study reveals that the position of the resonance depends both on the atom number and the interaction coupling, manifesting its many body nature. The corresponding mean field treatment as well as the single-band approximation have been found to be inadequate for the description of the tunneling dynamics in the interacting case. Deutsche Forschungsgemeinschaft, SFB 925 ``Light induced dynamics and control of correlated quantum systems''.

A novel harmonic control approach of distributed generation converters in a weak microgrid

DEFF Research Database (Denmark)

Ding, Guangqian; Gao, Feng; Tang, Yi

2014-01-01

as well as the long distance communication between the PCC and the converter are fully eliminated. In order to avoid overcompensation, a harmonic current limitation algorithm is implemented in the control loop. bBy properly dispatching the harmonic compensation capability, multiple DG unites can...

Third harmonic generation by Bloch-oscillating electrons in a quasioptical array

International Nuclear Information System (INIS)

Ghosh, A.W.; Wanke, M.C.; Allen, S.J.; Wilkins, J.W.

1999-01-01

We compute the third harmonic field generated by Bloch-oscillating electrons in a quasioptical array of superlattices under THz irradiation. The third harmonic power transmitted oscillates with the internal electric field, with nodes associated with Bessel functions in eEd/ℎω. The nonlinear response of the array causes the output power to be a multivalued function of the incident laser power. The output can be optimized by adjusting the frequency of the incident pulse to match one of the Fabry-Pacute erot resonances in the substrate. Within the transmission-line model of the array, the maximum conversion efficiency is 0.1%. copyright 1999 American Institute of Physics

The Technology of Suppressing Harmonics with Complex Neural Network is Applied to Microgrid

Science.gov (United States)

Zhang, Jing; Li, Zhan-Ying; Wang, Yan-ping; Li, Yang; Zong, Ke-yong

2018-03-01

According to the traits of harmonics in microgrid, a new CANN controller which combines BP and RBF neural network is proposed to control APF to detect and suppress harmonics. This controller has the function of current prediction. By simulation in Matlab / Simulink, this design can shorten the delay time nearly 0.02s (a power supply current cycle) in comparison with the traditional controller based on ip-iq method. The new controller also has higher compensation accuracy and better dynamic tracking traits, it can greatly suppress the harmonics and improve the power quality.

Exact diagonalization of the D-dimensional spatially confined quantum harmonic oscillator

Directory of Open Access Journals (Sweden)

Kunle Adegoke

2016-01-01

Full Text Available In the existing literature various numerical techniques have been developed to quantize the confined harmonic oscillator in higher dimensions. In obtaining the energy eigenvalues, such methods often involve indirect approaches such as searching for the roots of hypergeometric functions or numerically solving a differential equation. In this paper, however, we derive an explicit matrix representation for the Hamiltonian of a confined quantum harmonic oscillator in higher dimensions, thus facilitating direct diagonalization.

Development of the RTP crystal applications for Q-switching operation and second harmonics generation

International Nuclear Information System (INIS)

Alnayli, R.Sh.

2010-01-01

Complete text of publication follows. A dialed theoretical studies on performances of the ideal RTP crystal for the electro optical applications as Q-switching laser operation and for nonlinear optics application as second harmonics generation are accomplished in this paper. Single or pair RTP crystal of excellent quality with dimensions 5 x 5 x 7.5 mm 3 have proposed as element model to combined Q-switching operation and frequency doublers for 1.06 μm wave length laser. In order to get and interpolate the optimum conditions to combined both of these operations by application this RTP model. The main am of this work was investigated the most influent parameters on the performance of the electro optical Q-switching laser operation such as, the voltage requirement, contrast and extinction ratios, the birefringence effective and withstand threshold on the other hand the influences of the ray walk off, thermal effective on the efficiency of the second harmonics generation as well are investigated. The results were satisfied for the goals of this paper.

Waveguide harmonic damper for klystron amplifier

International Nuclear Information System (INIS)

Kang, Y.

1998-01-01

A waveguide harmonic damper was designed for removing the harmonic frequency power from the klystron amplifiers of the APS linac. Straight coaxial probe antennas are used in a rectangular waveguide to form a damper. A linear array of the probe antennas is used on a narrow wall of the rectangular waveguide for damping klystron harmonics while decoupling the fundamental frequency in dominent TE 01 mode. The klystron harmonics can exist in the waveguide as waveguide higher-order modes above cutoff. Computer simulations are made to investigate the waveguide harmonic damping characteristics of the damper

Surface structure enhanced second harmonic generation in organic nanofibers

DEFF Research Database (Denmark)

Fiutowski, Jacek; Maibohm, Christian; Kostiučenko, Oksana

Second-harmonic generation upon femto-second laser irradiation of nonlinearly optically active nanofibers grown from nonsymmetrically functionalized para-quarterphenylene (CNHP4) molecules is investigated. Following growth on mica templates, the nanofibers have been transferred onto lithography...

A Unified Voltage Harmonic Control Strategy for Coordinated Compensation with VCM and CCM Converters

DEFF Research Database (Denmark)

Zhao, Xin; Meng, Lexuan; Xie, Chuan

2018-01-01

-controlled mode (VCM) and current-controlled mode (CCM), need to cooperatively provide the compensation function. Aiming at this objective, this paper proposes a unified voltage harmonic mitigation strategy for VCM and CCM converters with high harmonic current sharing accuracy. Another advantage of the proposal......Harmonics have been considered as one of the major issues in modern power grids. Considering the high penetration level of power electronic converter interfaced distributed generators (DGs), it is of interest to provide ancillary services through DG interfacing converters, such as harmonic...... compensation. In case of that, multiple DG interfacing converters are utilized to compensate harmonics, and the compensation effort should be properly shared among these converters. However, it is rarely considered in existing literatures that converters operating in different modes, such as voltage...

High-order harmonic generation in a capillary discharge

Science.gov (United States)

Rocca, Jorge J.; Kapteyn, Henry C.; Mumane, Margaret M.; Gaudiosi, David; Grisham, Michael E.; Popmintchev, Tenio V.; Reagan, Brendan A.

2010-06-01

A pre-ionized medium created by a capillary discharge results in more efficient use of laser energy in high-order harmonic generation (HHG) from ions. It extends the cutoff photon energy, and reduces the distortion of the laser pulse as it propagates down the waveguide. The observed enhancements result from a combination of reduced ionization energy loss and reduced ionization-induced defocusing of the driving laser as well as waveguiding of the driving laser pulse. The discharge plasma also provides a means to spectrally tune the harmonics by tailoring the initial level of ionization of the medium.

A study on boiling water reactor regional stability from the viewpoint of higher harmonics

International Nuclear Information System (INIS)

Takeuchi, Yutaka; Takigawa, Yukio; Uematsu, Hitoshi

1994-01-01

A quantitative study on a mechanism for boiling water reactor regional stability has been carried out from the viewpoint of higher harmonics. In the mechanism, the gain decrease in the void-to-power transfer function can be explained by the higher harmonics mode subcriticality. It is shown that the thermal-hydraulic feedback effect can compensate for the gain decrease, and regional oscillation can be sustained that way. For quantitative evaluations, a three-dimensional higher harmonics analysis model has been developed. The results show that the first azimuthal harmonics subcriticality has a relatively small value under a regionally unstable condition. Comparing the subcriticality and the steady-state power distribution, it is shown that the distribution exists whose first azimuthal harmonics subcriticality takes a small value. A method of decomposition for the oscillated power responses into the harmonics modes is presented. The results show that the corewide oscillation power response consists almost entirely of the fundamental mode, and the regional oscillation power response consists almost entirely of the first azimuthal harmonics mode. This indicates that regional oscillation is a phenomenon in which the first azimuthal harmonics mode oscillates on the basis of the fundamental mode

Quantitative modeling of the third harmonic emission spectrum of plasmonic nanoantennas.

Science.gov (United States)

Hentschel, Mario; Utikal, Tobias; Giessen, Harald; Lippitz, Markus

2012-07-11

Plasmonic dimer nanoantennas are characterized by a strong enhancement of the optical field, leading to large nonlinear effects. The third harmonic emission spectrum thus depends strongly on the antenna shape and size as well as on its gap size. Despite the complex shape of the nanostructure, we find that for a large range of different geometries the nonlinear spectral properties are fully determined by the linear response of the antenna. We find excellent agreement between the measured spectra and predictions from a simple nonlinear oscillator model. We extract the oscillator parameters from the linear spectrum and use the amplitude of the nonlinear perturbation only as scaling parameter of the third harmonic spectra. Deviations from the model only occur for gap sizes below 20 nm, indicating that only for these small distances the antenna hot spot contributes noticeable to the third harmonic generation. Because of its simplicity and intuitiveness, our model allows for the rational design of efficient plasmonic nonlinear light sources and is thus crucial for the design of future plasmonic devices that give substantial enhancement of nonlinear processes such as higher harmonics generation as well as difference frequency mixing for plasmonically enhanced terahertz generation.

Improved H-κ Method by Harmonic Analysis on Ps and Crustal Multiples in Receiver Functions with respect to Dipping Moho and Crustal Anisotropy

Science.gov (United States)

Li, J.; Song, X.; Wang, P.; Zhu, L.

2017-12-01

The H-κ method (Zhu and Kanamori, 2000) has been widely used to estimate the crustal thickness and Vp/Vs ratio with receiver functions. However, in regions where the crustal structure is complicated, the method may produce uncertain or even unrealistic results, arising particularly from dipping Moho and/or crustal anisotropy. Here, we propose an improved H-κ method, which corrects for these effects first before stacking. The effect of dipping Moho and crustal anisotropy on Ps receiver function has been well studied, but not as much on crustal multiples (PpPs and PpSs+PsPs). Synthetic tests show that the effect of crustal anisotropy on the multiples are similar to Ps, while the effect of dipping Moho on the multiples is 5 times that on Ps (same cosine trend but 5 times in time shift). A Harmonic Analysis (HA) method for dipping/anisotropy was developed by Wang et al. (2017) for crustal Ps receiver functions to extract parameters of dipping Moho and crustal azimuthal anisotropy. In real data, the crustal multiples are much more complicated than the Ps. Therefore, we use the HA method (Wang et al., 2017), but apply separately to Ps and the multiples. It shows that although complicated, the trend of multiples can still be reasonably well represented by the HA. We then perform separate azimuthal corrections for Ps and the multiples and stack to obtain a combined receiver function. Lastly, the traditional H-κ procedure is applied to the stacked receiver function. We apply the improved H-κ method on 40 CNDSN (Chinese National Digital Seismic Network) stations distributed in a variety of geological setting across the Chinese continent. The results show apparent improvement compared to the traditional H-κ method, with clearer traces of multiples and stronger stacking energy in the grid search, as well as more reliable H-κ values.

In vivo time-harmonic multifrequency elastography of the human liver

International Nuclear Information System (INIS)

Tzschätzsch, Heiko; Guo, Jing; Streitberger, Kaspar-Josche; Fischer, Thomas; Sack, Ingolf; Ipek-Ugay, Selcan; Braun, Jürgen; Gentz, Enno; Klaua, Robert; Schultz, Michael

2014-01-01

Elastography is capable of noninvasively detecting hepatic fibrosis by imposing mechanical stress and measuring the viscoelastic response in the liver. Magnetic resonance elastography (MRE) relies on time-harmonic vibrations, while most dynamic ultrasound elastography methods employ transient stimulation methods. This study attempts to benefit from the advantages of time-harmonic tissue stimulation, i.e. relative insensitivity to obesity and ascites and mechanical approachability of the entire liver, and the advantages of ultrasound, i.e. time efficiency, low costs, and wide availability, by introducing in vivo time-harmonic elastography (THE) of the human liver using ultrasound and a broad range of harmonic stimulation frequencies. THE employs continuous harmonic shear vibrations at 7 frequencies from 30 to 60 Hz in a single examination and determines the elasticity and the viscosity of the liver from the dispersion of the shear wave speed within the applied frequency range. The feasibility of the method is demonstrated in the livers of eight healthy volunteers and a patient with cirrhosis. Multifrequency MRE at the same drive frequencies was used as elastographic reference method. Similar values of shear modulus and shear viscosity according the Kelvin–Voigt model were obtained by MRE and THE, indicating that the new method is suitable for in vivo quantification of the shear viscoelastic properties of the liver, however, in real-time and at a fraction of the costs of MRE. In conclusion, THE may provide a useful tool for fast assessment of the viscoelastic properties of the liver at low costs and without limitations in obesity, ascites or hemochromatosis. (paper)

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

DEFF Research Database (Denmark)

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

2016-01-01

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

On single nucleon wave functions in nuclei

International Nuclear Information System (INIS)

Talmi, Igal

2011-01-01

The strong and singular interaction between nucleons, makes the nuclear many body theory very complicated. Still, nuclei exhibit simple and regular features which are simply described by the shell model. Wave functions of individual nucleons may be considered just as model wave functions which bear little resemblance to the real ones. There is, however, experimental evidence for the reality of single nucleon wave functions. There is a simple method of constructing such wave functions for valence nucleons. It is shown that this method can be improved by considering the polarization of the core by the valence nucleon. This gives rise to some rearrangement energy which affects the single valence nucleon energy within the nucleus.

ANA IIF Automation: Moving towards Harmonization? Results of a Multicenter Study

Directory of Open Access Journals (Sweden)

Stefanie Van den Bremt

2017-01-01

Full Text Available Background. Our study aimed to investigate whether the introduction of automated anti-nuclear antibody (ANA indirect immunofluorescence (IIF analysis decreases the interlaboratory variability of ANA titer results. Method. Three serum samples were sent to 10 laboratories using the QUANTA-Lyser® in combination with the NOVA View®. Each laboratory performed the ANA IIF analysis 10x in 1 run and 1x in 10 different runs and determined the endpoint titer by dilution. One of the three samples had been sent in 2012, before the era of ANA IIF automation, by the Belgian National External Quality Assessment (EQA Scheme. Harmonization was evaluated in terms of variability in fluorescence intensity (LIU and ANA IIF titer. Results. The evaluation of the intra- and interrun LIU variability revealed a larger variability for 2 laboratories, due to preanalytical and analytical problems. Reanalysis of the EQA sample resulted in a lower titer variability. Diluted endpoint titers were similar to the estimated single well titer and the overall median titer as reported by the EQA in 2012. Conclusion. The introduction of automated microscopic analysis allows more harmonized ANA IIF reporting, provided that this totally automated process is controlled by a thorough quality assurance program, covering the total ANA IIF process.

Differing effects of attention in single-units and populations are well predicted by heterogeneous tuning and the normalization model of attention.

Science.gov (United States)

Hara, Yuko; Pestilli, Franco; Gardner, Justin L

2014-01-01

Single-unit measurements have reported many different effects of attention on contrast-response (e.g., contrast-gain, response-gain, additive-offset dependent on visibility), while functional imaging measurements have more uniformly reported increases in response across all contrasts (additive-offset). The normalization model of attention elegantly predicts the diversity of effects of attention reported in single-units well-tuned to the stimulus, but what predictions does it make for more realistic populations of neurons with heterogeneous tuning? Are predictions in accordance with population-scale measurements? We used functional imaging data from humans to determine a realistic ratio of attention-field to stimulus-drive size (a key parameter for the model) and predicted effects of attention in a population of model neurons with heterogeneous tuning. We found that within the population, neurons well-tuned to the stimulus showed a response-gain effect, while less-well-tuned neurons showed a contrast-gain effect. Averaged across the population, these disparate effects of attention gave rise to additive-offsets in contrast-response, similar to reports in human functional imaging as well as population averages of single-units. Differences in predictions for single-units and populations were observed across a wide range of model parameters (ratios of attention-field to stimulus-drive size and the amount of baseline response modifiable by attention), offering an explanation for disparity in physiological reports. Thus, by accounting for heterogeneity in tuning of realistic neuronal populations, the normalization model of attention can not only predict responses of well-tuned neurons, but also the activity of large populations of neurons. More generally, computational models can unify physiological findings across different scales of measurement, and make links to behavior, but only if factors such as heterogeneous tuning within a population are properly accounted for.

Policy harmonized approach for the EU agricultural sector modelling

Directory of Open Access Journals (Sweden)

G. SALPUTRA

2008-12-01

Full Text Available Policy harmonized (PH approach allows for the quantitative assessment of the impact of various elements of EU CAP direct support schemes, where the production effects of direct payments are accounted through reaction prices formed by producer price and policy price add-ons. Using the AGMEMOD model the impacts of two possible EU agricultural policy scenarios upon beef production have been analysed – full decoupling with a switch from historical to regional Single Payment scheme or alternatively with re-distribution of country direct payment envelopes via introduction of EU-wide flat area payment. The PH approach, by systematizing and harmonizing the management and use of policy data, ensures that projected differential policy impacts arising from changes in common EU policies reflect the likely actual differential impact as opposed to differences in how “common” policies are implemented within analytical models. In the second section of the paper the AGMEMOD model’s structure is explained. The policy harmonized evaluation method is presented in the third section. Results from an application of the PH approach are presented and discussed in the paper’s penultimate section, while section 5 concludes.;

Highlighting the harmonic regime generated by electric locomotives equipped with DC motors

Science.gov (United States)

Baciu, I.; Cunţan, C. D.

2018-01-01

The paper presents the results of measurements made using the C.A. 8334 power quality analyzer on an electric locomotive equipped with DC motors. We carried out determinations of the current-voltage regime using a locomotive motor. The harmonic regime of the other motors being identical to the analysed one, we could easily deduce the effects caused by the entire locomotive. The data measured with the analyzer were firstly transferred into a computer system using the Qualistar software, followed by data processing in Excel, enabling therefore a graphical representation of the characteristic parameters of power quality. Based on the acquired data, we determined the power factor, as well as the active, reactive and apparent power. The measurements revealed high values of the current harmonics, fact that required some measures to be taken for reducing the values of these harmonics. For this, we ran a simulation using the PSCAD/EMTDC software, by introducing LC filters in tune with the harmonic frequencies. The result was a significant reduction in the harmonic regime, either in the harmonics values or the power factor and reactive power.

Harmonic Damping in DG-Penetrated Distribution Network

DEFF Research Database (Denmark)

Lu, Jinghang; Savaghebi, Mehdi; Guerrero, Josep M.

2016-01-01

Grid background harmonics may be amplified, propagate through a long distribution feeder and even lead to power system instability. In this paper, harmonic propagation issue is investigated and mitigation of the harmonics is analyzed by using transmission line theory which has already been applied...... in power systems. It is demonstrated that a specific harmonic will not be amplified if the feeder’s length is less than one quarter of the harmonic wavelength meanwhile the terminal impedance is less than characteristic impedance. Besides, three scenarios will be considered in accordance...... with the relationship between the feeder’s length and harmonic wavelength. Harmonic suppression control strategies will be respectively designed considering 5th and 7th harmonics coexisting in the distribution line. Finally, a simulation study has been performed to verify the theoretical analysis and demonstrate...

Coherent excitonic nonlinearity versus inhomogeneous broadening in single quantum wells

DEFF Research Database (Denmark)

Langbein, Wolfgang Werner; Borri, Paola; Hvam, Jørn Märcher

1998-01-01

The coherent response of excitons in semiconductor nanostructures, as measured in four wave mixing (FWM) experiments, depends strongly on the inhomogeneous broadening of the exciton transition. We investigate GaAs-AlGaAs single quantum wells (SQW) of 4 nm to 25 nm well width. Two main mechanisms...

Secondary magnetic field harmonics dependence on vacuum beam chamber geometry

Directory of Open Access Journals (Sweden)

S. Y. Shim

2013-08-01

Full Text Available The harmonic magnetic field properties due to eddy currents have been studied with respect to the geometry of the vacuum beam chamber. We derived a generalized formula enabling the precise prediction of any field harmonics generated by eddy currents in beam tubes with different cross-sectional geometries. Applying our model to study the properties of field harmonics in beam tubes with linear dipole magnetic field ramping clearly proved that the circular cross section tube generates only a dipole field from eddy currents. The elliptic tube showed noticeable magnitudes of sextupole and dipole fields. We demonstrate theoretically that it is feasible to suppress the generation of the sextupole field component by appropriately varying the tube wall thickness as a function of angle around the tube circumference. This result indicates that it is possible to design an elliptical-shaped beam tube that generates a dipole field component with zero magnitude of sextupole. In a rectangular-shaped beam tube, one of the selected harmonic fields can be prevented if an appropriate wall thickness ratio between the horizontal and vertical tube walls is properly chosen. Our generalized formalism can be used for optimization of arbitrarily complex-shaped beam tubes, with respect to suppression of detrimental field harmonics.

The Methodological Background for Harmonizing Components of Sustainable Development of an Industrial City

Directory of Open Access Journals (Sweden)

Prushkivskyj Volodymyr G.

2016-11-01

Full Text Available The aim of the article is to develop a methodological background for harmonizing components of sustainable development of an industrial city. The ways of harmonization of economic, environmental and social components are studied. It is proposed to use the rule of «golden ratio» to determine the «ideal» values of the components of sustainable development. On the basis of the index method the components of sustainable development are evaluated. The comparative analysis of the actual and harmonic distribution between the sub-indices of sustainable development is performed. Based on the rule of «golden ratio» it is proved that the harmonization allows to state the existence of differences as well as to carry out a quantitative analysis. It is justified that the existence of disharmony between the components of sustainable development requires elaboration of an appropriate mechanism on the basis of redistribution of investment resources as well as other economic instruments to support the components at a certain level.

Harmonic strengths of PEP dipoles and some related effects and lessons

International Nuclear Information System (INIS)

Spencer, J.E.

1981-09-01

The harmonic content of magnets such as the standard PEP bend is (among other things) a function of excitation current, the way the current is set and even the magnetization history. For instance, harmonic strengths generally vary not only with the magnitude of the current but the direction and rate at which the current is approached and set. The field distribution resulting from different procedures can vary markedly depending on both the mechanical and magnetic design and the degree to which eddy current effects are emphasized. Variations among magnets of the same design result from variations in the iron as well as overall magnet fabrication procedures. Because the field distribution may also depend in the previous history of a magnet, all PEP dipoles were subjected to what are called ''magnetization'' and ''standardization'' cycles before measurement---the latter depending on the former and intended to set the initial conditions of the magnet to a reproducible standard. The primary goal of the magnetic measurements was then to determine the dipole strength as a function of current for each magnet based on a practical setting algorithm. The main constraints on the algorithm were reproducibility of the integrated field, speed, power and reduction of higher harmonics. Quadrupole and sextupole strengths were also measured on about one-half of the magnets at one current. This note presents the data and discusses it from the the viewpoint of subsequent measurements with stored beams. The most important conclusion is that inability to fully distribute laminations according to heat number and/or strike number results in ''magnetic personalities'' among the magnets which are quite difficult to deal with afterwards although one can distribute ''non-standard'' magnets to minimize orbit distributions. 26 refs., 8 figs., 3 tabs

Effect of accelerating field third harmonic on microtron steady-state conditions and limiting current

International Nuclear Information System (INIS)

Kol'tsov, A.V.; Serov, A.V.

1992-01-01

Setting the acceleration regime in a microtron with the resonator in which the third accelerating field harmonic is excited by accelerated clusters is considered. It is shown that excitation of the accelerating field third harmonic in the microtron resonator (E 011 mode) causes a 1.5 time increase of the range of field intensity values under which resonance particle acceleration is possible. Under moderate energies and accelerated currents (10-15 MeV, 50-80 mA) this leads to a reduction of requirements to the stability of power coming to the resonator and cathode temperature. Under accelerated currents of > 100 mA the third harmonic complicates the microtron transition to acceleration regime. The microtron transfers to stable autooscillation regime, but the current achieved in a single short pulse is increased. By varying the value of the resonator quality factor on the third harmonic one can change the current pulse duration and autooscillation period

Harmonic Interaction Analysis in Grid-connected Converter using Harmonic State Space (HSS) Modeling

DEFF Research Database (Denmark)

Kwon, Jun Bum; Wang, Xiongfei; Blaabjerg, Frede

2017-01-01

research about the harmonic interaction. However, it is found that the Linear Time Invariant (LTI) based model analysis makes it difficult to analyze these phenomena because of the time-varying properties of the power electronic based systems. This paper investigates grid-connected converter by using......An increasing number of power electronic based Distributed Generation (DG) systems and loads generate not only characteristic harmonics but also unexpected harmonics. Several methods like impedance based analysis, which are derived from the conventional average model, are introduced to perform...

Presence of strong harmonics during visual entrainment: a magnetoencephalography study.

Science.gov (United States)

Heinrichs-Graham, Elizabeth; Wilson, Tony W

2012-09-01

Visual neurons are known to synchronize their firing with stimuli that flicker at a constant rate (e.g. 12Hz). These so-called visual steady-state responses (VSSR) are a well-studied phenomenon, yet the underlying mechanisms are widely disagreed upon. Furthermore, there is limited evidence that visual neurons may simultaneously synchronize at harmonics of the stimulation frequency. We utilized magnetoencephalography (MEG) to examine synchronization at harmonics of the visual stimulation frequency (18Hz). MEG data were analyzed for event-related-synchronization (ERS) at the fundamental frequency, 36, 54, and 72Hz. We found strong ERS in all bands. Only 31% of participants showed maximum entrainment at the fundamental; others showed stronger entrainment at either 36 or 54Hz. The cortical foci of these responses indicated that the harmonics involved cortices that were partially distinct from the fundamental. These findings suggest that spatially-overlapping subpopulations of neurons are simultaneously entrained at different harmonics of the stimulus frequency. Copyright © 2012 Elsevier B.V. All rights reserved.

Decoupling of fluctuating power in single-phase systems through a symmetrical half-bridge circuit

DEFF Research Database (Denmark)

Tang, Yi; Blaabjerg, Frede; Loh, Poh Chiang

2014-01-01

Single-phase AC/DC or DC/AC systems inherently subject to harmonic disturbance which is caused by the well-known double line frequency ripple power. This issue can be eased through the installation of bulky electrolytic capacitors in the dc-link, but such passive filtering approach may inevitably...

Computing single step operators of logic programming in radial basis function neural networks

Science.gov (United States)

Hamadneh, Nawaf; Sathasivam, Saratha; Choon, Ong Hong

2014-07-01

Logic programming is the process that leads from an original formulation of a computing problem to executable programs. A normal logic program consists of a finite set of clauses. A valuation I of logic programming is a mapping from ground atoms to false or true. The single step operator of any logic programming is defined as a function (Tp:I→I). Logic programming is well-suited to building the artificial intelligence systems. In this study, we established a new technique to compute the single step operators of logic programming in the radial basis function neural networks. To do that, we proposed a new technique to generate the training data sets of single step operators. The training data sets are used to build the neural networks. We used the recurrent radial basis function neural networks to get to the steady state (the fixed point of the operators). To improve the performance of the neural networks, we used the particle swarm optimization algorithm to train the networks.

Computing single step operators of logic programming in radial basis function neural networks

Energy Technology Data Exchange (ETDEWEB)

Hamadneh, Nawaf; Sathasivam, Saratha; Choon, Ong Hong [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

2014-07-10

Logic programming is the process that leads from an original formulation of a computing problem to executable programs. A normal logic program consists of a finite set of clauses. A valuation I of logic programming is a mapping from ground atoms to false or true. The single step operator of any logic programming is defined as a function (T{sub p}:I→I). Logic programming is well-suited to building the artificial intelligence systems. In this study, we established a new technique to compute the single step operators of logic programming in the radial basis function neural networks. To do that, we proposed a new technique to generate the training data sets of single step operators. The training data sets are used to build the neural networks. We used the recurrent radial basis function neural networks to get to the steady state (the fixed point of the operators). To improve the performance of the neural networks, we used the particle swarm optimization algorithm to train the networks.