Harmonic distortion correction in pipelined analog to digital converters
Panigada, Andrea
2009-01-01T23:59:59.000Z
Background Correction of Harmonic Distortion in PipelinedBackground Correction of Harmonic Distortion in PipelinedADC with 69dB SNDR Enabled by Digital Harmonic Distortion
Gou, Jian
1992-01-01T23:59:59.000Z
have been established to specify the limitation on the magnitudes of both harmonic currents and harmonic voltage distortion at different frequencies. Among these the "IEEE Guide for Harmonic Control and Reactive Compensation of Static Power... by the utility and by the electricity consumer has arrived. These measurements include: current and voltage harmonics, input power 1'actor, reactive power, real power, total harmonic distortion (THD), percentage load unbalance, etc. The measured data can...
Reactive Power Sharing and Voltage Harmonic Distortion Compensation of Droop Controlled
Vasquez, Juan Carlos
1 Reactive Power Sharing and Voltage Harmonic Distortion Compensation of Droop Controlled Single, the inverters typically employ the droop control scheme. Traditional droop control enables the decentralized regulation of the local voltage and frequency of the microgrid by the inverters. The droop method also
Yan, Jun
2012-07-16T23:59:59.000Z
design methodology of sinusoidal oscillator named digital-harmonic-cancellation (DHC) technique is presented. DHC technique is realized by summing up a set of square-wave signals with different phase shifts and different summing coefficient to cancel...
Harmonic analysis for the characterization and correction of geometric distortion in MRI
Tadic, Tony, E-mail: ttadic@gmail.com; Stanescu, Teodor [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Department of Medical Biophysics, University of Toronto, Toronto M5G 1L7 (Canada)
2014-11-01T23:59:59.000Z
Purpose: Magnetic resonance imaging (MRI) is gaining widespread use in radiation therapy planning, patient setup verification, and real-time guidance of radiation delivery. Successful implementation of these technologies relies on the development of simple and efficient methods to characterize and monitor the geometric distortions arising due to system imperfections and gradient nonlinearities. To this end, the authors present the theory and validation of a novel harmonic approach to the quantification of system-related distortions in MRI. Methods: The theory of spatial encoding in MRI is applied to demonstrate that the 3D distortion vector field (DVF) is given by the solution of a second-order boundary value problem (BVP). This BVP is comprised of Laplace’s equation and a limited measurement of the distortion on the boundary of a specified region of interest (ROI). An analytical series expansion solving this BVP within a spherical ROI is obtained, and a statistical uncertainty analysis is performed to determine how random errors in the boundary measurements propagate to the ROI interior. This series expansion is then evaluated to obtain volumetric DVF mappings that are compared to reference data obtained on a 3 T full-body scanner. This validation is performed within two spheres of 20 cm diameter (one centered at the scanner origin and the other offset +3 cm along each of the transverse directions). Initially, a high-order mapping requiring measurements at 5810 boundary points is used. Then, after exploring the impact of the boundary sampling density and the effect of series truncation, a reduced-order mapping requiring measurements at 302 boundary points is evaluated. Results: The volumetric DVF mappings obtained from the harmonic analysis are in good agreement with the reference data. Following distortion correction using the high-order mapping, the authors estimate a reduction in the mean distortion magnitude from 0.86 to 0.42 mm and from 0.93 to 0.39 mm within the central and offset ROIs, respectively. In addition, the fraction of points with a distortion magnitude greater than 1 mm is reduced from 35.6% to 2.8% and from 40.4% to 1.5%, respectively. Similarly, following correction using the reduced-order mapping, the mean distortion magnitude reduces to 0.45–0.42 mm within the central and offset ROIs, and the fraction of points with a distortion magnitude greater than 1 mm is reduced to 2.8% and 1.5%, respectively. Conclusions: A novel harmonic approach to the characterization of system-related distortions in MRI is presented. This method permits a complete and accurate mapping of the DVF within a specified ROI using a limited measurement of the distortion on the ROI boundary. This technique eliminates the requirement to exhaustively sample the DVF at a dense 3D array of points, thereby permitting the design of simple, inexpensive phantoms that may incorporate additional modules for auxiliary quality assurance objectives.
Rendusara, Dudi Abdullah
1995-01-01T23:59:59.000Z
ANALYSIS AND DESIGN OF SIX AND TWELVE PULSE DIODE RECTIFIER SYSTEMS UNDER VOLTAGE UNBALANCE/DISTORTION AND SOME NEW METHODS TO REDUCE INPUT CURRENT HARMONICS A Thesis by DUDI ABDULLAH RENDUSARA Submitted to the Office of Graduate Studies.../DISTORTION AND SOME NEW METHODS TO REDUCE INPUT CURRENT HARMONICS A Thesis by DUDI ABDULLAH RENDUSARA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved...
The effects of output transformers on distortion in audio amplifiers
Lanier, Ross Edwin
1949-01-01T23:59:59.000Z
Introduction ~. . . . . . . . , . . . . . . ~. . . . . 7 Frequency Discrimination. . . . . . . . . . . . . . . . 9 Harmonic Distortion. ~ ~. . . . ~ 21 Distortion by the Intermodulationmethod. . . . . . . . 47 Comparison of Harmonic and Intermodulation... current in the primary as a function of frequency . 19 Output voltage of transformer 3 without direct current in the primary as a function of frequency 20 Block diagram for measuring distortion by the harmonic method 26 Per cent harmonic distortion...
Analysis and Design of New Harmonic Mitigation Approaches
Aeloiza Matus, Eddy 1972-
2012-11-01T23:59:59.000Z
-pulse rectifiers are based on the principle of harmonic cancellation through phase shifting and are the preferred solution to eliminate harmonics in high power converters in large motor drives, electro-winning rectifiers and HVDC transmission systems [23...-voltage systems can have up to 2.0% THD where the cause is an HVDC terminal that will attenuate by the time it is tapped for user. Individual Harmonic Order (Odd Harmonics) Isc / IL <11 11 ? h"? 17 17 ? h"? 23 23 ? h"? 35 h"? 35 TDD <20 * 4.0 2...
Cryogenic THD and DT layer implosions with high density carbon ablators in near-vacuum hohlraums
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Meezan, N. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Berzak Hopkins, L. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000291875667); Le Pape, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Divol, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacKinnon, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Döppner, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ho, D. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jones, O. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Khan, S. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ma, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Milovich, J. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pak, A. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ross, J. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thomas, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Benedetti, L. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bradley, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Celliers, P. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Clark, D. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000272137538); Field, J. E. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA; Haan, S. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000184045131); Izumi, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kyrala, G. A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moody, J. D. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA; Patel, P. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ralph, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rygg, J. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sepke, S. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Spears, B. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tommasini, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Town, R. P. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Biener, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bionta, R. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bond, E. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Caggiano, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Eckart, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gatu Johnson, M. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Grim, G. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hamza, A. V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hartouni, E. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)] (ORCID:0000000198694351); Hatarik, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hoover, D. E. [General Atomics, San Diego, CA (United States)] (ORCID:0000000195652551); Kilkenny, J. D. [General Atomics, San Diego, CA (United States); Kozioziemski, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kroll, J. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McNaney, J. M. [General Atomics, San Diego, CA (United States); Nikroo, A. [General Atomics, San Diego, CA (United States); Sayre, D. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2015-06-01T23:59:59.000Z
High Density Carbon (HDC or diamond) is a promising ablator material for use in near-vacuum hohlraums, as its high density allows for ignition designs with laser pulse durations of et al., Phys. Plasmas 16, 041006 (2009)] culminated in a DT layered implosion driven by a 6.8 ns, 2-shock laser pulse. This paper describes these experiments and comparisons with ICF design code simulations. Backlit radiography of a THD layered capsule demonstrated an ablator implosion velocity of 385 km/s with a slightly oblate hot spot shape. Other diagnostics suggested an asymmetric compressed fuel layer. A streak camera-based hot spot self-emission diagnostic (SPIDER) showed a double-peaked history of the capsule self-emission. Simulations suggest that this is a signature of low quality hot spot formation. Changes to the laser pulse and pointing for a subsequent DT implosion resulted in a higher temperature, prolate hot spot and a thermonuclear yield of 1.8 x 10¹? neutrons, 40% of the 1D simulated yield.
Cryogenic THD and DT layer implosions with high density carbon ablators in near-vacuum hohlraums
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Meezan, N. B.; Berzak Hopkins, L. F.; Le Pape, S.; Divol, L.; MacKinnon, A. J.; Döppner, T.; Ho, D. D.; Jones, O. S.; Khan, S. F.; Ma, T.; et al
2015-06-01T23:59:59.000Z
High Density Carbon (HDC or diamond) is a promising ablator material for use in near-vacuum hohlraums, as its high density allows for ignition designs with laser pulse durations of et al., Phys. Plasmas 16, 041006 (2009)] culminated in a DT layered implosion driven by a 6.8 ns, 2-shock laser pulse. This paper describes these experiments and comparisons with ICF design code simulations. Backlit radiography of a THD layered capsule demonstrated an ablator implosion velocity of 385 km/s with a slightlymore »oblate hot spot shape. Other diagnostics suggested an asymmetric compressed fuel layer. A streak camera-based hot spot self-emission diagnostic (SPIDER) showed a double-peaked history of the capsule self-emission. Simulations suggest that this is a signature of low quality hot spot formation. Changes to the laser pulse and pointing for a subsequent DT implosion resulted in a higher temperature, prolate hot spot and a thermonuclear yield of 1.8 x 10¹? neutrons, 40% of the 1D simulated yield.« less
A new space vector PWM control strategy for high performance converters
Xie, Bin
1993-01-01T23:59:59.000Z
high quality output voltage. DC to AC inverter system with proposed modulator achieves DC link voltage ripple immunity and maintain low Total Harmonic Distortion (THD) specification across the terminals of a nonlinear load....
A Novel High Frequency, High-Efficiency, Differential Class-E Power Amplifier in 0.18m CMOS
Heydari, Payam
-- This paper presents the design of a high efficiency, low THD, 5.7GHz fully differential power amplifier integration, the design of an on-chip front- end power amplifier with a low total-harmonic distortion (THD-Frequency Integrated Circuits, Class-E Power Amplifier, Injection-Locked, Oscillator, Phase Noise, Jitter. 1
Alam, K.Y.; Clark, D.P.
1990-01-01T23:59:59.000Z
Since sulfur dioxide emission from burning high sulfur coals is a major contributor to acid rain, it is important to develop bacteria which are capable of efficiently removing the sulfur from coal before combustion. Inorganic sulfur can be removed from coal by certain strains of Thiobacillus or Sulfolobus; however the organic sulfur remains intransigent. Since high sulfur Illinois coals typically contain 60% to 70% of their sulfur in the form of the heterocyclic thiophene ring we have started to investigate the biodegradation of derivatives of thiophene and the corresponding oxygen heterocycle, furan. Our previous work resulted in the isolation of a triple mutant, NAR30, capable of oxidizing a range of furan and thiophene derivatives. However, NAR30 does not completely degrade thiophenes or furans and its oxidation of these compounds is slow and inefficient. We decided to clone the thd genes both in order to increase the efficiency of degradation and to investigate the nature of the reactions involved. 37 refs., 4 figs., 3 tabs.
Mints, M.Ya.; Chinkov, V.N.
1995-09-01T23:59:59.000Z
Rational algorithms for measuring the harmonic coefficient in microprocessor instruments for measuring nonlinear distortions based on digital processing of the codes of the instantaneous values of the signal being investigated are described and the errors of such instruments are obtained.
System and methods for reducing harmonic distortion in electrical converters
Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M
2013-12-03T23:59:59.000Z
Systems and methods are provided for delivering energy using an energy conversion module. An exemplary method for delivering energy from an input interface to an output interface using an energy converison module coupled between the input interface and the output interface comprises the steps of determining an input voltage reference for the input interface based on a desired output voltage and a measured voltage and the output interface, determining a duty cycle control value based on a ratio of the input voltage reference and the measured voltage, operating one or more switching elements of the energy conversion module to deliver energy from the input interface to the output interface to the output interface with a duty cycle influenced by the dute cycle control value.
Bennett, Charles L. (Livermore, CA)
2009-10-20T23:59:59.000Z
A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line connecting an expansion chamber of the expander to a buffer chamber of the expander for minimizing pressure variations in the fluidic circuit of the engine. The engine is especially designed to operate with very high temperature input to the expander and very low temperature input to the compressor, to produce very high thermal conversion efficiency.
Bennett, Charles L.; Sewall, Noel; Boroa, Carl
2014-08-19T23:59:59.000Z
An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a harmonic oscillator inlet valve capable of oscillating at a resonant frequency for controlling the flow of working fluid into of 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. Upon releasing the inlet valve the inlet valve head undergoes a single oscillation past the equilibrium positio 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. Protrusions carried either by the inlet valve head or piston head are used to bump open the inlet valve from the closed position and initiate the single oscillation of the inlet valve head, and protrusions carried either by the outlet valve head or piston head are used to close the outlet valve ahead of the bump opening of the inlet valve.
Current Generated Harmonics and Their Effect Upon Electrical Industrial Systems
Alexander, H. R.; Rogge, D. S.
of the nonlinear loads with respect to that system. The distortion increases as the percentage of nonlinear loads increases. (2) PROBLEMS ENCOUNTERED WITH HARMONICS High Neutral Conductor Currcnts Perhaps the dominant harmonic problem encountered... in commercial facilities and some industrial plants has been the overheating of neutral conductors of 3-phase, 4-wire branch and feeder distribution systems. In a balanced, 3-phase, 4-wire wye system with phase-to-ncutral linear loads, the neutral current...
Sliding-mode amplitude control techniques for harmonic oscillators
Marquart, Chad A.
2007-09-17T23:59:59.000Z
signal operating at frequencies ranging from 170 MHz to 2.1 GHz. Total harmonic distortion is maintained below 0:8% for an oscillation amplitude of 2 Vpp over the entire tuning range. Phase noise is measured as -105.6 dBc/Hz at 1.135 GHz with a 1 MHz...
Source Coding with Mismatched Distortion Measures
Niesen, Urs; Wornell, Gregory
2008-01-01T23:59:59.000Z
We consider the problem of lossy source coding with a mismatched distortion measure. That is, we investigate what distortion guarantees can be made with respect to distortion measure $\\tilde{\\rho}$, for a source code designed such that it achieves distortion less than $D$ with respect to distortion measure $\\rho$. We find a single-letter characterization of this mismatch distortion and study properties of this quantity. These results give insight into the robustness of lossy source coding with respect to modeling errors in the distortion measure. They also provide guidelines on how to choose a good tractable approximation of an intractable distortion measure.
Tchamran-Savehi, Abbas
1958-01-01T23:59:59.000Z
for their help and suggestions. Special thanks are extended to Professor R. P. Ward for his tieely advice during the course of the present wor'k. CONTENTS Preface Page PART I. ? GENERAL Introduction Graphical Nethod The Problem History of Harmonic... Analysers Nathematical Aspects of Harmonic Analysers PART II. ? A NEW ELECTRO-Ng CHANICAL HARNONIC ANALYZER Sumsmry Description of the New Harmonic Analyser Introducing the Harmonics Dismnsions of a Complex Wave Electrical Integrator 14 16 20 22...
Harmonization of Biodiesel Specifications
Alleman, T. L.
2008-02-01T23:59:59.000Z
Worldwide biodiesel production has grown dramatically over the last several years. Biodiesel standards vary across countries and regions, and there is a call for harmonization. For harmonization to become a reality, standards have to be adapted to cover all feedstocks. Additionally, all feedstocks cannot meet all specifications, so harmonization will require standards to either tighten or relax. For harmonization to succeed, the biodiesel market must be expanded with the alignment of test methods and specification limits, not contracted.
High-order harmonic generation in a capillary discharge
Rocca, Jorge J.; Kapteyn, Henry C.; Mumane, Margaret M.; Gaudiosi, David; Grisham, Michael E.; Popmintchev, Tenio V.; Reagan, Brendan A.
2010-06-01T23:59:59.000Z
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.
harmonic analysis and geometry
Faculty listing for "harmonic analysis and geometry". vCard of Nicola Garofalo Garofalo, Nicola [bio] [homepage] Adjunct Professor of Mathematics
Safe-commutation principle for direct single-phase AC-AC converters for use in audio power
and G, expressed as very low total harmonic distortion + noise (THD+N) levels and supplemented. SIngle Conversion stage AMplifier (SICAM) is the next im- portant evolutionary step in designing-stage AC-AC audio power amplifiers. As compared with the bridge commutation with load current or source
Electrodynamic spherical harmonic
Andrey Novitsky
2008-03-28T23:59:59.000Z
Electrodynamic spherical harmonic is a second rank tensor in three-dimensional space. It allows to separate the radial and angle variables in vector solutions of Maxwell's equations. Using the orthonormalization for electrodynamic spherical harmonic, a boundary problem on a sphere can be easily solved.
Mark W. Coffey
2008-12-09T23:59:59.000Z
We evaluate binomial series with harmonic number coefficients, providing recursion relations, integral representations, and several examples. The results are of interest to analytic number theory, the analysis of algorithms, and calculations of theoretical physics, as well as other applications.
DATABASE AUTHENTICATION BY DISTORTION FREE WATERMARKING
Cortesi, Tino
DATABASE AUTHENTICATION BY DISTORTION FREE WATERMARKING Sukriti Bhattacharya and Agostino Cortesi@dsi.unive.it, cortesi@unive.it Keywords: Database watermarking, ZAW, Public key watermark, Abstract interpretation the verification of integrity of the relational databases by using a public zero distortion authentication
Summers, Mark A. (Livermore, CA); Eimerl, David (Pleasanton, CA); Boyd, Robert D. (Livermore, CA)
1985-01-01T23:59:59.000Z
A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The "extraordinary" or "e" directions of the crystal elements are oriented in the integral assembly to be in quadrature (90.degree.). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude "o" and "e" components. For a third-harmonic generation, the input fundamental wave has "o" and "e" components whose amplitudes are in a ratio of 2:1 ("o":"e" reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10.degree.. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axes ("o").
Summers, M.A.; Eimerl, D.; Boyd, R.D.
1982-06-10T23:59:59.000Z
A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The extraordinary or e directions of the crystal elements are oriented in the integral assembly to be in quadrature (90/sup 0/). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude o and e components. For a third-harmonic generation, the input fundamental wave has o and e components whose amplitudes are in a ratio of 2:1 (o:e reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10/sup 0/. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axeses (o).
Harmonic functions on Walsh's Brownian motion
Jehring, Kristin Elizabeth
2009-01-01T23:59:59.000Z
4.3 Harmonic Functions . . . . . . . . . . . . . . .Chapter 3 Harmonic Functions . . . . . . . . . . . . . . 3.1Markov Chains 4.3.2 Harmonic Functions for the Embedded
Harmonic resolution as a holographic quantum number
Bousso, Raphael
2009-01-01T23:59:59.000Z
LBNL- 57239 Harmonic resolution as a holographic quantumhep-th/0310223 UCB-PTH-03/26 Harmonic resolution as aquantum number, the harmonic resolution K. The Bekenstein
Second Harmonic Generation From Surfaces
Botti, Silvana
Second Harmonic Generation From Surfaces Nicolas Tancogne-Dejean, ValÃ©rie VÃ©niard Condensed Matter/DSM European Theoretical Spectroscopy Facility #12;2 Outline Nonlinear optic and second harmonic generation;4 Second harmonic generation First nonlinear term Centrosymmetric material : (2) = 0 (3)First nonlinear
Analytic Continuation of Harmonic Sums
S. Albino
2009-03-06T23:59:59.000Z
We present a method for calculating any (nested) harmonic sum to arbitrary accuracy for all complex values of the argument. The method utilizes the relation between harmonic sums and (derivatives of) Hurwitz zeta functions, which allows a harmonic sum to be calculated as an expansion valid for large values of its argument. A program for implementing this method is also provided.
Optimal risk sharing under distorted probabilities
Ludkovski, Michael; Young, Virginia R.
2009-01-01T23:59:59.000Z
theory of risk. Geneva Pap. Risk Insurance Theory 25, 141–A. : Two-persons ef?cient risk-sharing and equilibria for36(2), 189–223 (2008) Optimal risk sharing under distorted
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Michael, J. Robert; Volkov, Anatoliy
2015-01-23T23:59:59.000Z
The widely used pseudoatom formalism [Stewart (1976). Acta Cryst. A32, 565–574; Hansen & Coppens (1978). Acta Cryst. A34, 909–921] in experimental X-ray charge-density studies makes use of real spherical harmonics when describing the angular component of aspherical deformations of the atomic electron density in molecules and crystals. The analytical form of the densitynormalized Cartesian spherical harmonic functions for up to l 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens [Acta Cryst. (1988), A44, 6–7]. It was shown that the analytical form for normalization coefficients is available primarily for l 4 [Hansen & Coppens, 1978; Paturlemore »& Coppens, 1988; Coppens (1992). International Tables for Crystallography, Vol. B, Reciprocal space, 1st ed., edited by U. Shmueli, ch. 1.2. Dordrecht: Kluwer Academic Publishers; Coppens (1997). X-ray Charge Densities and Chemical Bonding. New York: Oxford University Press]. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 4 the density normalization coefficients were calculated numerically to within seven significant figures. In this study we review the literature on the density-normalized spherical harmonics, clarify the existing notations, use the Paturle–Coppens (Paturle & Coppens, 1988) method in the Wolfram Mathematica software to derive the Cartesian spherical harmonics for l 20 and determine the density normalization coefficients to 35 significant figures, and computer-generate a Fortran90 code. The article primarily targets researchers who work in the field of experimental X-ray electron density, but may be of some use to all who are interested in Cartesian spherical harmonics.« less
Coulomb Distortion in the Inelastic Regime
Patricia Solvignon, Dave Gaskell, John Arrington
2009-09-01T23:59:59.000Z
The Coulomb distortion effects have been for a long time neglected in deep inelastic scattering for the good reason that the incident energies were very high. But for energies in the range of earlier data from SLAC or at JLab, the Coulomb distortion could have the potential consequence of affecting the A-dependence of the EMC effect and of the longitudinal to transverse virtual photon absorption cross section ratio $R(x,Q^2)$.
Coulomb distortion in the inelastic regime
Solvignon, P.; Arrington, J. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Gaskell, D. [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States)
2009-09-02T23:59:59.000Z
The Coulomb distortion effects have been for a long time neglected in deep inelastic scattering for the good reason that the incident energies were very high. But for energies in the range of earlier data from SLAC or at JLab, the Coulomb distortion could have the potential consequence of affecting the A-dependence of the EMC effect and of the longitudinal to transverse virtual photon absorption cross section ratio R(x,Q{sup 2}).
Coulomb distortion in the inelastic regime.
Solvignon, P.; Gaskell, D.; Arrington, J.; Physics; Thomas Jefferson National Accelerator Facility
2009-01-01T23:59:59.000Z
The Coulomb distortion effects have been for a long time neglected in deep inelastic scattering for the good reason that the incident energies were very high. But for energies in the range of earlier data from SLAC or at JLab, the Coulomb distortion could have the potential consequence of affecting the A-dependence of the EMC effect and of the longitudinal to transverse virtual photon absorption cross section ratio R(x,Q{sup 2}).
Reflective optical imaging systems with balanced distortion
Hudyma, Russell M. (San Ramon, CA)
2001-01-01T23:59:59.000Z
Optical systems compatible with extreme ultraviolet radiation comprising four reflective elements for projecting a mask image onto a substrate are described. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical systems are particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput, and allows higher semiconductor device density. The inventive optical systems are characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.
Reflective optical imaging system with balanced distortion
Chapman, Henry N. (Sunol, CA); Hudyma, Russell M. (San Ramon, CA); Shafer, David R. (Fairfield, CT); Sweeney, Donald W. (San Ramon, CA)
1999-01-01T23:59:59.000Z
An optical system compatible with short wavelength (extreme ultraviolet) An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput and allows higher semiconductor device density. The inventive optical system is characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.
Zigzag laser with reduced optical distortion
Albrecht, G.F.; Comaskey, B.; Sutton, S.B.
1994-04-19T23:59:59.000Z
The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends. 11 figures.
Zigzag laser with reduced optical distortion
Albrecht, Georg F. (Livermore, CA); Comaskey, Brian (Stockton, CA); Sutton, Steven B. (Manteca, CA)
1994-01-01T23:59:59.000Z
The architecture of the present invention has been driven by the need to solve the beam quality problems inherent in Brewster's angle tipped slab lasers. The entrance and exit faces of a solid state slab laser are cut perpendicular with respect to the pump face, thus intrinsically eliminating distortion caused by the unpumped Brewster's angled faces. For a given zigzag angle, the residual distortions inherent in the remaining unpumped or lightly pumped ends may be reduced further by tailoring the pump intensity at these ends.
S. C. Tiwari
2007-06-09T23:59:59.000Z
A generalized harmonic map equation is presented based on the proposed action functional in the Weyl space (PLA, 135, 315, 1989).
Paris-Sud XI, UniversitÃ© de
loudspeakers, a motor converts the electrical signal in motion and makes a cone vibrate. The piston-like movement of the cone generates the sound field. The motor induces non-linearities because of non models. Gallman [12] and Hawksford [11] proposed a method using Gaussian noise at different amplitudes
Harmonic Wavelet Transform and Image Approximation
Zhang, Zhihua; Saito, Naoki
2010-01-01T23:59:59.000Z
DOI 10.1007/s10851-010-0202-x Harmonic Wavelet Transform andwe approximate f by a harmonic function u such that thebanks. We call this the Harmonic Wavelet Transform (HWT).
Carroll, D.P. [Florida Univ., Gainesville, FL (United States); Kasturi, S. [MOS, Inc., Melville, NY (United States); Subudhi, M.; Gunther, W. [Brookhaven National Lab., Upton, NY (United States)
1992-12-31T23:59:59.000Z
Most previous analysis on the effects of geomagnetically induced currents (GIC) on electric utility systems has steady-state phenomena, with the main interest in the generator step-up transformer and the off-site power system. This paper begins to investigate the possible effects that a GIC event might have on the power plant itself, by examining the harmonic distortion that could exist at various voltage levels in the on-site distribution system.
Carroll, D.P. (Florida Univ., Gainesville, FL (United States)); Kasturi, S. (MOS, Inc., Melville, NY (United States)); Subudhi, M.; Gunther, W. (Brookhaven National Lab., Upton, NY (United States))
1992-01-01T23:59:59.000Z
Most previous analysis on the effects of geomagnetically induced currents (GIC) on electric utility systems has steady-state phenomena, with the main interest in the generator step-up transformer and the off-site power system. This paper begins to investigate the possible effects that a GIC event might have on the power plant itself, by examining the harmonic distortion that could exist at various voltage levels in the on-site distribution system.
CORRECTION OF BUTT-WELDING INDUCED DISTORTIONS BY LASER FORMING
Yao, Y. Lawrence
CORRECTION OF BUTT-WELDING INDUCED DISTORTIONS BY LASER FORMING Peng Cheng, Andrew J. Birnbaum, Y Egland Technology and Solutions Division Caterpillar Inc. Peoria, IL KEYWORDS Welding, Distortion, Correction, Laser Forming ABSTRACT Welding-induced distortion is an intrinsic phenomenon arising due
PSYCHOACOUSTICALLY CONSTRAINED AND DISTORTION MINIMIZED SPEECH ENHANCEMENT ALGORITHM
Yoo, Chang D.
PSYCHOACOUSTICALLY CONSTRAINED AND DISTORTION MINIMIZED SPEECH ENHANCEMENT ALGORITHM Seokhwan Jo minimized speech enhancement algorithm is considered. In general, noise reduction leads to speech distortion, and thus, the goal of an enhancement al- gorithm should reduce noise and speech distortion so that both
Investigation of distortional buckling of cold-formed steel sections
Birmingham, University of
to transverse uniform loading. #12;Background Local, distortional and lateral-torsional bucklings are three and lateral-torsional buckling, the distortional buckling is a relatively new concept, has a very short on the interaction between the distortional buckling and other failure modes such as local buckling, lateral
Low Distortion Welded Joints for NCSX
M. Denault, M Viola, W. England
2009-02-19T23:59:59.000Z
The National Compact Stellarator Experiment (NCSX) required precise positioning of the field coils in order to generate suitable magnetic fields. A set of three modular field coils were assembled to form the Half Field-Period Assemblies (HPA). Final assembly of the HPA required a welded shear plate to join individual coils in the nose region due to the geometric limitations and the strength constraints. Each of the modular coil windings was wound on a stainless steel alloy (Stellalloy) casting. The alloy is similar to austenitic 316 stainless steel. During the initial welding trials, severe distortion, of approximately 1/16", was observed in the joint caused by weld shrinkage. The distortion was well outside the requirements of the design. Solutions were attempted through several simultaneous routes. The joint design was modified, welding processes were changed, and specialized heat reduction techniques were utilized. A final joint design was selected to reduce the amount of weld material needed to be deposited, while maintaining adequate penetration and strength. Several welding processes and techniques using Miller Axcess equipment were utilized that significantly reduced heat input. The final assembly of the HPA was successful. Distortion was controlled to 0.012", well within the acceptable design tolerance range of 0.020" over a 3.5 foot length.
Hadronization Scheme Dependence of Long-Range Azimuthal Harmonics in High Energy p+A Reactions
Esposito, Angelo
2015-01-01T23:59:59.000Z
We compare the distortion effects of three popular final state hadronization schemes that modify the initial-state gluon azimuthal harmonic correlations in high energy p+A collisions. The three models considered are (1) LPH: local parton-hadron duality, (2) CPR: collinear parton-hadron resonance independent fragmenation, and (3) LUND: color string hadronization. Strong initial-state multi-gluon azimuthal correlations are generated using the non-abelian beam jet bremsstrahlung GLVB model, assuming a saturation scale Qsat = 2 GeV. Long-range final hadron pair elliptic and triangular harmonics are compared based on the three hadronization schemes. Our analysis shows that the hadron level harmonics are strongly hadronization scheme dependent in the low pT < 3 GeV domain.
On The Harmonic Oscillator Group
Raquel M. Lopez; Sergei K. Suslov; Jose M. Vega-Guzman
2011-12-04T23:59:59.000Z
We discuss the maximum kinematical invariance group of the quantum harmonic oscillator from a view point of the Ermakov-type system. A six parameter family of the square integrable oscillator wave functions, which seems cannot be obtained by the standard separation of variables, is presented as an example. The invariance group of generalized driven harmonic oscillator is shown to be isomorphic to the corresponding Schroedinger group of the free particle.
Echo-Enabled Harmonic Generation
Stupakov, Gennady; /SLAC
2012-06-28T23:59:59.000Z
A recently proposed concept of the Echo-Enabled Harmonic Generation (EEHG) FEL uses two laser modulators in combination with two dispersion sections to generate a high-harmonic density modulation in a relativistic beam. This seeding technique holds promise of a one-stage soft x-ray FEL that radiates not only transversely but also longitudinally coherent pulses. Currently, an experimental verification of the concept is being conducted at the SLAC National Accelerator Laboratory aimed at the demonstration of the EEHG.
UV Second-Harmonic Studies of Concentrated Aqueous Electrolyte Interfaces
Otten, Dale Edward
2010-01-01T23:59:59.000Z
Probed by UV Second Harmonic Generation, in Department ofby UV Second Harmonic Generation Spectroscopy," 114, 13746with Femtosecond Second Harmonic Generation Spectroscopy,"
artificial grid distortion: Topics by E-print Network
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Samuel 3 A Distortion-Theoretic Perspective for Redundant Metering Security in a Smart Grid Computer Technologies and Information Sciences Websites Summary: A...
Lattice Distortions and Oxygen Vacancies Produced in Au+-Irradiated...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the efficiency of solid oxide fuel cells can be improved. Citation: Edmondson PD, WJ Weber, F Namavar, and Y Zhang.2011."Lattice Distortions and Oxygen Vacancies Produced in...
Harmonic algebraic curves and noncrossing partitions
Martin, Jeremy L.; Savitt, David; Singer, Ted
2007-02-01T23:59:59.000Z
Motivated by Gauss’s first proof of the fundamental Theorem of Algebra, we study the topology of harmonic algebraic curves. By the maximum principle, a harmonic curve has no bounded components; its topology is determined by the combinatorial data...
Harmonic generation from indium-rich plasmas
Ganeev, R. A.; Kulagin, I. A. [Akadempribor Scientific Association, Academy of Sciences of Uzbekistan, Tashkent 700125 (Uzbekistan); Singhal, H.; Naik, P. A.; Arora, V.; Chakravarty, U.; Chakera, J. A.; Khan, R. A.; Raghuramaiah, M.; Gupta, P. D. [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Redkin, P. V. [Samarkand State University, Samarkand 703004 (Uzbekistan)
2006-12-15T23:59:59.000Z
An experimental study of high-order harmonic generation in In, InSb, InP, and InGaP plasmas using femtosecond laser radiation with variable chirp is presented. Intensity enhancement of the 13th and 21st harmonics compared to the neighboring harmonics by a factor of 200 and 10, respectively, is observed. It is shown that the harmonic spectrum from indium-containing plasma plumes can be considerably modified by controlling the chirp of the driving laser pulse.
Reduced Harmonic Representation of Partitions
Michalis Psimopoulos
2011-03-08T23:59:59.000Z
In the present article the reduced integral representation of partitions in terms of harmonic products has been derived first by using hypergeometry and the new concept of fractional sum and secondly by studying the Fourier series of the kernel function appearing in the integral representation. Using the method of induction, a generalization of the theory has also been obtained.
The Quantum Harmonic Oscillator C. David Sherrill
Sherrill, David
The Quantum Harmonic Oscillator C. David Sherrill School of Chemistry and Biochemistry Georgia Institute of Technology February 2002 1 Introduction The harmonic oscillator is extremely useful by coupled harmonic oscillators. The atoms are viewed as point masses which are connected by bonds which act
spherical harmonics for l < 20
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Michael, J. Robert [Middle Tennessee State University; Volkov, Anatoliy [Middle Tennessee State University
2015-01-23T23:59:59.000Z
The widely used pseudoatom formalism [Stewart (1976). Acta Cryst. A32, 565–574; Hansen & Coppens (1978). Acta Cryst. A34, 909–921] in experimental X-ray charge-density studies makes use of real spherical harmonics when describing the angular component of aspherical deformations of the atomic electron density in molecules and crystals. The analytical form of the densitynormalized Cartesian spherical harmonic functions for up to l 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens [Acta Cryst. (1988), A44, 6–7]. It was shown that the analytical form for normalization coefficients is available primarily for l 4 [Hansen & Coppens, 1978; Paturle & Coppens, 1988; Coppens (1992). International Tables for Crystallography, Vol. B, Reciprocal space, 1st ed., edited by U. Shmueli, ch. 1.2. Dordrecht: Kluwer Academic Publishers; Coppens (1997). X-ray Charge Densities and Chemical Bonding. New York: Oxford University Press]. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 4 the density normalization coefficients were calculated numerically to within seven significant figures. In this study we review the literature on the density-normalized spherical harmonics, clarify the existing notations, use the Paturle–Coppens (Paturle & Coppens, 1988) method in the Wolfram Mathematica software to derive the Cartesian spherical harmonics for l 20 and determine the density normalization coefficients to 35 significant figures, and computer-generate a Fortran90 code. The article primarily targets researchers who work in the field of experimental X-ray electron density, but may be of some use to all who are interested in Cartesian spherical harmonics.
Minimization of welding residual stress and distortion in large structures
Michaleris, Panagiotis
1 Minimization of welding residual stress and distortion in large structures P. Michaleris at Champaign Urbana, Urbana, IL Abstract Welding distortion in large structures is usually caused by buckling due to the residual stress. In cases where the design is fixed and minimum weld size requirements
Stable radial distortion calibration by polynomial matrix inequalities programming
Henrion, Didier
polynomials. Further, we show how to model these nonnegativities using polynomial matrix inequalities (PMI) and how to estimate the radial distortion parameters subject to PMI constraints using semidefinite to stabilize the shape of the distortion function. It is based on polynomial matrix inequalities (PMI
Coexistence of Weak Ferromagnetism and Polar Lattice Distortion...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
that are isostructural with acentric LiNbO3 (space group R3c). Optical second harmonic generation and magnetometry demonstrate lattice polarization at room temperature and...
Leahy, Richard M.
Harmonic MappingsConstrained Harmonic Mappings Anand A Joshi1, David W Shattuck2, Paul M Thompson2 and Richard M Leahy1 Subcortical Structure AIR Harmonic HAMMER Harmonic +Intensity Left Thalamus 0.79 0.68 0. Extrapolation of the surface map to the entire cortical volume by a harmonic map. 3. Refinement of the harmonic
Hyperspherical harmonic formalism for tetraquarks
J. Vijande; N. Barnea; A. Valcarce
2006-10-11T23:59:59.000Z
We present a generalization of the hyperspherical harmonic formalism to study systems made of quarks and antiquarks of the same flavor. This generalization is based on the symmetrization of the $N-$body wave function with respect to the symmetric group using the Barnea and Novoselsky algorithm. Our analysis shows that four-quark systems with non-exotic $2^{++}$ quantum numbers may be bound independently of the quark mass. $0^{+-}$ and $1^{+-}$ states become attractive only for larger quarks masses.
Harmonic Chain with Weak Dissipation
A. A. Lykov; V. A. Malyshev
2013-02-20T23:59:59.000Z
We consider finite harmonic chain (consisting of N classical particles) plus dissipative force acting on one particle (called dissipating particle) only. We want to prove that "in the generic case" the energy (per particle) for the whole system tends to zero in the large time limit and then in the large N limit. "In the generic case" means: for almost all initial conditions and for almost any choice of the dissipating particle, in the thermodynamic limit.
Estimation problems in the space of distorted stochastic processes
Moutran, Cyril
1996-01-01T23:59:59.000Z
(u). Clearly, if Y(u) F 8s, for a given g, there exists a stationary process X such that X(u) = g. g. g. Example Let Y be a real-valued stochastic process defined by: Y(t) = A cos(k, t + kit ) + B sin(k, t + k t ) where A and B are uncorrelated random... The expected oalue of the squared Jacobian of a distorted process Y(u), is proportional to the squared Jacobian of the associated distortion function. Throughout the end of this chapter, we only consider the case when the distortion g(t) is a one...
THE THICKNESS DISTORTION OF Fe 57 BACKSCATTER MOSSBAUER SPECTRA
Fultz, B.
2013-01-01T23:59:59.000Z
F. Weise, and P. Flinn, "Mossbauer Spectrometry for AnalysisOF Fe 57 BACKSCATTER MOSSBAUER SPECTRA B. Fultz and J. W.DISTORTION OF Fe BACKSCATTER MOSSBAUER SPECTRA B. Fultz and
Laser with dynamic holographic intracavity distortion correction capability
Cronin-Golomb, M.; Fischer, B.; Nilsen, J.; White, J.O.; Yariv, A.
1982-08-01T23:59:59.000Z
We report here a novel laser resonator with the ability to correct for intracavity phase distortions. The optical cavity employs a passive (self-pumped) phase conjugate reflector to provide this capability.
Strain Accommodation By Facile WO6 Octahedral Distortion and...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
to other BO6 octahedra in ABO3 structured perovskite oxides, the WO6 octahedra in tungsten trioxide (WO3) can withstand a much larger degree of distortion and tilting to...
Explicit deconvolution of wellbore storage distorted well test data
Bahabanian, Olivier
2007-04-25T23:59:59.000Z
¢Â?Â? at downhole (or sandface) conditions. While accurate pressure measurements are commonplace, the measurement of sandface flowrates is rare, essentially non-existent in practice. As such, the "deconvolution" of wellbore storage distorted pressure test data...
Projection lithography with distortion compensation using reticle chuck contouring
Tichenor, Daniel A. (Castro Valley, CA)
2001-01-01T23:59:59.000Z
A chuck for holding a reflective reticle where the chuck has an insulator block with a non-planer surface contoured to cause distortion correction of EUV radiation is provided. Upon being placed on the chuck, a thin, pliable reflective reticle will conform to the contour of the chuck's non-planer surface. When employed in a scanning photolithography system, distortion in the scanned direction is corrected.
Parameterization of temperature and spectral distortions in future CMB experiments
Cyril Pitrou; Albert Stebbins
2015-01-05T23:59:59.000Z
CMB spectral distortions are induced by Compton collisions with electrons. We review the various schemes to characterize the anisotropic CMB with a non-Planckian spectrum. We advocate using logarithmically averaged temperature moments as the preferred language to describe these spectral distortions, both for theoretical modeling and observations. Numerical modeling is simpler, the moments are frame-independent, and in terms of scattering the mode truncation is exact.
Killing vector fields and harmonic superfield theories
Groeger, Josua, E-mail: groegerj@mathematik.hu-berlin.de [Humboldt-Universität zu Berlin, Institut für Mathematik, Rudower Chaussee 25, 12489 Berlin (Germany)
2014-09-15T23:59:59.000Z
The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.
Extra Harmonic Vowel in Chicahuaxtla Trique
Matsukawa, Kosuke
2008-01-01T23:59:59.000Z
Extra Harmonic Vowel in Chicahuaxtla Trique1 Kosuke Matsukawa State University of New York at Albany 1. Introduction Chicahuaxtla Trique is spoken in Oaxaca, Mexico and belongs to the Trique language group of the Mixtecan family...). In Chicahuaxtla Trique, an extra harmonic vowel is added after a laryngealized vowel (either a glottalized vowel or an aspirated vowel) in a final syllable. The extra harmonic vowel does not exist in Copala Trique or Itunyoso Trique and is attached mostly...
Felkner, L. J.; Waggoner, R. M.
The control of harmonics in power systems continues to be a major concern in the telecommunications industry. AC/DC telecommunication conversion equipment has rarely been thought of as playing a major role in the harmonic interaction problem. Yet...
Harmonic Analysis Errors in Calculating Dipole,
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
to reduce the harmonic field calculation errors. A conformal transfor- mation of a multipole magnet into a dipole reduces these errors. Dipole Magnet Calculations A triangular...
Modulation compression for short wavelength harmonic generation
Qiang, J.
2010-01-01T23:59:59.000Z
Wavelength Harmonic Generation Ji Qiang Lawrence Berkeleyform a basis for fourth generation light source. Currently,e?ciency was proposed for generation of short wavelength
Harmonic Cheeger-Simons characters with applications
Richard Green; Varghese Mathai
2009-02-13T23:59:59.000Z
We initiate the study of harmonic Cheeger-Simons characters, with applications to smooth versions of the Geometric Langlands program in the abelian case.
Making space for harmonic oscillators
Michelotti, Leo; /Fermilab
2004-11-01T23:59:59.000Z
If we restrict the number of harmonic oscillator energy eigenstates to some finite value, N, then the discrete spectrum of the corresponding position operator comprise the roots of the Hermite polynomial H{sub N+1}. Its range is just large enough to accommodate classical motion at high energy. A negative energy term must be added to the Hamiltonian which affects only the last eigenstate, |N>, suggesting it is concentrated at the extrema of this finite ''space''. Calculations support a conjecture that, in the limit of large N, the global distribution of points approaches the differential form for classical action.
Harmonic potential and hadron spectroscopy
Rafael Tumanyan
2009-05-28T23:59:59.000Z
The quark-gluon sea in the hadrons is considered as periodically correlated. Energy levels of Shrodinger equation with harmonic potential is used for describing of the spectrum of hadron masses. In the considered cases the effective potential operating on each particle of ensemble, under certain conditions becomes square-law on displacement from a equilibrium point. It can become an explanation of popularity of oscillator potential for the description of a spectrum of masses of elementary particles. The analysis shows that levels of periodic potential better agreed to the spectrum of hadron masses, than levels of other potentials used for an explanation of a spectrum of masses.
Constructing Buildings and Harmonic Maps
Katzarkov, Ludmil; Pandit, Pranav; Simpson, Carlos
2015-01-01T23:59:59.000Z
In a continuation of our previous work, we outline a theory which should lead to the construction of a universal pre-building and versal building with a $\\phi$-harmonic map from a Riemann surface, in the case of two-dimensional buildings for the group $SL_3$. This will provide a generalization of the space of leaves of the foliation defined by a quadratic differential in the classical theory for $SL_2$. Our conjectural construction would determine the exponents for $SL_3$ WKB problems, and it can be put into practice on examples.
Olea, Jr., Charles
2010-01-01T23:59:59.000Z
of wild-type Tt H-NOX as well as energy minimizations 19with energy minimizations and visual inspection of the wild-high- energy frontier orbitals. 81 Heme distortion in wild-
A Formal model to aid documenting and harmonizing of information
Zheng, Yuliang
A Formal model to aid documenting and harmonizing of information security requirements Jussipekka Information security development, harmonization of information security, organizational modeling 1 INTRODUCTION A formal top down model to harmonize and document information security requirements shall
HARMONIC MAPPINGS BETWEEN RIEMANNIAN MANIFOLDS Anand Arvind Joshi
Leahy, Richard M.
HARMONIC MAPPINGS BETWEEN RIEMANNIAN MANIFOLDS by Anand Arvind Joshi A Thesis Presented ii Abstract iv 1 Harmonic Mappings 1 1.1 Space of Maps Variation Formula . . . . . . . . . . . . . . . . . . . . . . . . 11 1.4 Harmonic Maps
Acoustoelectric Harmonic Generation in a Photoconductive Piezoelectric Semiconductor
Acoustoelectric Harmonic Generation in a Photoconductive Piezoelectric Semiconductor W. Arthur, R harmonics in the low frequency regime (. Piezoelectric semiconductors can exhibit harmonic generation because of interactions between the acoustic
Radiation reaction and quantum damped harmonic oscillator
F. Kheirandish; M. Amooshahi
2005-07-19T23:59:59.000Z
By taking a Klein-Gordon field as the environment of an harmonic oscillator and using a new method for dealing with quantum dissipative systems (minimal coupling method), the quantum dynamics and radiation reaction for a quantum damped harmonic oscillator investigated. Applying perturbation method, some transition probabilities indicating the way energy flows between oscillator, reservoir and quantum vacuum, obtained
Harmonic cascade FEL designs for LUX
2004-01-01T23:59:59.000Z
1.3: a fully 3D time-dependent FEL sim- ulation code, Nucl.a XUV/soft X-ray harmonic-cascade FEL for the proposed LBNLLBNL-56329 Harmonic cascade FEL designs for LUX G. Penn, M.
Impact of stray capacitance on hvdc harmonics
Larsen, E.V.; Sublich, M.; Kapoor, S.C.
1989-01-01T23:59:59.000Z
Recent experience suggests that a new approach is needed to determining harmonic generation from hvdc converters for the purpose of telephone interference evaluation. This paper presents simulation results showing the effect on harmonic generation of stray capacitances inherent to hvdc converters. These simulation results illustrate the basic characteristics of the phenomenon, which agree qualitatively with field experience.
CHAPLIN - Complex Harmonic Polylogarithms in Fortran
Stephan Buehler; Claude Duhr
2011-06-28T23:59:59.000Z
We present a new Fortran library to evaluate all harmonic polylogarithms up to weight four numerically for any complex argument. The algorithm is based on a reduction of harmonic polylogarithms up to weight four to a minimal set of basis functions that are computed numerically using series expansions allowing for fast and reliable numerical results.
Simões, Marcelo Godoy
, fluorescent tube lighting, pc's and laptops have become more prominent in the residential household. With an expectation of higher penetrations of electric vehicle chargers and renewable energy devices the increased usage of nonlinear devices by type. The disadvantage to this approach is that it relies upon
advanced harmonic filter: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Hazem ZUBI Signature: 12;iv ABSTRACT LOWPASS BROADBAND HARMONIC FILTER DESIGN Zubi passive harmonic filter (IBF) for three phase diode rectifier front-end type adjustable speed...
Intermodulation distortion in a directly modulated semiconductor injection laser
Lau, K.Y.; Yariv, A.
1984-11-15T23:59:59.000Z
A most important quantity in high-frequency analog transmission is the intermodulation distortion product. Experimental studies of the third order intermodulation distortion products in the modulation response of high-speed semiconductor lasers give very low values (<-60 dB) at low frequencies, an increase at a rate of 40 dB/dec as the modulation frequency is increased, and a leveling off at one-half of the relaxation oscillation resonance frequency. These experimental results can be well explained by a theory based on a perturbative analysis of laser dynamics.
Low thermal distortion extreme-UV lithography reticle
Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)
2001-01-01T23:59:59.000Z
Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.
Low thermal distortion extreme-UV lithography reticle
Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)
2002-01-01T23:59:59.000Z
Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.
Low thermal distortion Extreme-UV lithography reticle and method
Gianoulakis, Steven E. (Albuquerque, NM); Ray-Chaudhuri, Avijit K. (Livermore, CA)
2002-01-01T23:59:59.000Z
Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.
A high-fidelity harmonic drive model.
Preissner, C.; Royston, T. J.; Shu, D. (APS Engineering Support Division); ( MCS); (Univ. of Illinois)
2012-01-01T23:59:59.000Z
In this paper, a new model of the harmonic drive transmission is presented. The purpose of this work is to better understand the transmission hysteresis behavior while constructing a new type of comprehensive harmonic drive model. The four dominant aspects of harmonic drive behavior - nonlinear viscous friction, nonlinear stiffness, hysteresis, and kinematic error - are all included in the model. The harmonic drive is taken to be a black box, and a dynamometer is used to observe the input/output relations of the transmission. This phenomenological approach does not require any specific knowledge of the internal kinematics. In a novel application, the Maxwell resistive-capacitor hysteresis model is applied to the harmonic drive. In this model, sets of linear stiffness elements in series with Coulomb friction elements are arranged in parallel to capture the hysteresis behavior of the transmission. The causal hysteresis model is combined with nonlinear viscous friction and spectral kinematic error models to accurately represent the harmonic drive behavior. Empirical measurements are presented to quantify all four aspects of the transmission behavior. These measurements motivate the formulation of the complete model. Simulation results are then compared to additional measurements of the harmonic drive performance.
RATE DISTORTION OPTIMIZED DOCUMENT CODING USING RESOLUTION ENHANCED RENDERING
RATE DISTORTION OPTIMIZED DOCUMENT CODING USING RESOLUTION ENHANCED RENDERING Guotong Feng , Hui at a fixed bit rate. This method, which we call resolution enhanced rendering (RER), works by adaptively enhanced rendering (RER) for jointly optimizing the THIS WORK IS SUPPORTED BY THE XEROX FOUNDATION. MRC
Technical Note Correction of Eddy-Current Distortions in Diffusion
Technical Note Correction of Eddy-Current Distortions in Diffusion Tensor Images Using the Known,2 Purpose: To correct eddy-current artifacts in diffusion ten- sor (DT) images without the need to obtain- tortions caused by eddy currents induced by large diffusion gradients. We propose a new postacquisition
Distortion management in slow-light pulse delay
Gauthier, Daniel
. K. Lee, and A. Yariv, "Scattering theory analysis of waveguide-resonator coupling," Phys. Rev. E 62, 73897404 (2000). 5. A. Yariv, Y. Xu, R. K. Lee, and A. Scherer, "Coupled resonator optical waveguideDistortion management in slow-light pulse delay Michael D. Stenner and Mark A. Neifeld University
Simulation of Heat Treatment Distortion R.A. Hardin1
Beckermann, Christoph
quenched in water and in oil. Unfortunately, due to the lack of documentation on the heat treatment process a test piece casting to be produced at a participating foundry to provide data on heat treatmentSimulation of Heat Treatment Distortion R.A. Hardin1 and C. Beckermann2 1 Research Engineer, 2
System for interferometric distortion measurements that define an optical path
Bokor, Jeffrey; Naulleau, Patrick
2003-05-06T23:59:59.000Z
An improved phase-shifting point diffraction interferometer can measure both distortion and wavefront aberration. In the preferred embodiment, the interferometer employs an object-plane pinhole array comprising a plurality of object pinholes located between the test optic and the source of electromagnetic radiation and an image-plane mask array that is positioned in the image plane of the test optic. The image-plane mask array comprises a plurality of test windows and corresponding reference pinholes, wherein the positions of the plurality of pinholes in the object-plane pinhole array register with those of the plurality of test windows in image-plane mask array. Electromagnetic radiation that is directed into a first pinhole of object-plane pinhole array thereby creating a first corresponding test beam image on the image-plane mask array. Where distortion is relatively small, it can be directly measured interferometrically by measuring the separation distance between and the orientation of the test beam and reference-beam pinhole and repeating this process for at least one other pinhole of the plurality of pinholes of the object-plane pinhole array. Where the distortion is relative large, it can be measured by using interferometry to direct the stage motion, of a stage supporting the image-plane mask array, and then use the final stage motion as a measure of the distortion.
Tariff Reform in the Presence of Sector-specific Distortions
BEGHIN, JOHN C; Karp, Larry
1990-01-01T23:59:59.000Z
chosen the highest or lowest tariff. gives: ASSUMPTION 1'.the optimal .distortion (tariff, or (tQ dZ T dt - sQ d y Tsensitive to existing fixed tariffs t = in f i nr.s a and
Dual aperture dipole magnet with second harmonic component
Praeg, W.F.
1983-08-31T23:59:59.000Z
An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.
Dual aperture dipole magnet with second harmonic component
Praeg, Walter F. (Palos Park, IL)
1985-01-01T23:59:59.000Z
An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.
Local Harmonic Estimation in Musical Sound Rafael A. IRIZARRY
Irizarry, Rafael A.
Local Harmonic Estimation in Musical Sound Signals Rafael A. IRIZARRY Statistical modeling so a local harmonic model that tracks changes in pitch and in the amplitudes of the harmonics is fit estimates of the harmonic signal and of the noise signal. Different musical composition applications may
High-Order Harmonic Generation of Heteronuclear Diatomic Molecules
Chu, Shih-I
High-Order Harmonic Generation of Heteronuclear Diatomic Molecules in Intense Ultrashort Laser ionization (MPI) and high-order harmonic generation (HHG) processes of N2 and CO molecules in intense laser of the homonuclear N2 molecule can generate only odd harmonics, both even and odd harmonics can be produced from
SEVENTH HARMONIC 20 GHz CO-GENERATOR
Hirshfield, Jay L
2014-04-08T23:59:59.000Z
To satisfy the need for multi-MW rf sources in frequency ranges where commercial sources do not exist, a study was undertaken on a class of devices based on gyro-harmonic frequency multiplication. This mechanism relies upon adding energy in gyrating motion to a linear electron beam that traverses a rotating-mode TE111-mode drive cavity in a dc magnetic field. The beam then drifts along the magnetic field into a second cavity, operating in the TEn11-mode tuned to the nth harmonic of the drive cavity. Studies of this configuration have been carried out for 2 < n < 7. Results are given for multi-MW, efficient operation of a 7th harmonic device operating at 20 GHz, and a 2nd harmonic device operating at 22.4 GHz.
SPECTRAL APPROXIMATION OF TIME-HARMONIC MAXWELL ...
2014-10-25T23:59:59.000Z
the electric permittivity, ? is the frequency of the harmonic wave, n is the unit outward normal of D ... In order to deal with more general scatterers D and non-
boundary behavior of univalent harmonic mappings
1910-70-32T23:59:59.000Z
valent harmonic mapping f from the unit disk U “onto” a bounded convex ..... Our next result examines the stability of a function f given in The- orem 2 upon the ...
Localized waves with spherical harmonic symmetries
Mills, M. S.
We introduce a class of propagation invariant spatiotemporal optical wave packets with spherical harmonic symmetries in their field configurations. The evolution of these light orbitals is considered theoretically in ...
Harmonizing Systems and Software Cost Estimation
Wang, Gan
2009-07-19T23:59:59.000Z
The objective of this paper is to examine the gaps and overlaps between software and systems engineering cost models with intent to harmonize the estimates in engineering engineering estimation. In particular, we evaluate ...
Harmonic Representation of Combinations and Partitions
Michalis Psimopoulos
2011-03-01T23:59:59.000Z
In the present article a new method of deriving integral representations of combinations and partitions in terms of harmonic products has been established. This method may be relevant to statistical mechanics and to number theory.
Some examples of exponentially harmonic maps
A D Kanfon; A Füzfa; D Lambert
2002-05-15T23:59:59.000Z
The aim of this paper is to study some examples of exponentially harmonic maps. We study such maps firstly on flat euclidean and Minkowski spaces and secondly on Friedmann-Lema\\^ itre universes. We also consider some new models of exponentially harmonic maps which are coupled with gravity which happen to be based on a generalization of the lagrangian for bosonic strings coupled with dilatonic field.
HARMONIC CAVITY PERFORMANCE FOR NSLS-II
BLEDNYKH, A.; KRINSKY, S.; PODOBEDOV, B.; ROSE, J.; TOWNE, N.; WANG, J.M.
2005-05-15T23:59:59.000Z
NSLS-II is a 3 GeV ultra-high brightness storage ring planned to succeed the present NSLS rings at BNL. Ultralow emittance combined with short bunch length means that it is critical to minimize the effects of Touschek scattering and coherent instabilities. Improved lifetime and stability can be achieved by including a third-harmonic RF cavity in the baseline design. This paper describes the required harmonic RF parameters and the expected system performance.
Coherent states for the nonlinear harmonic oscillator
Ghosh, Subir [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 B. T. Road, Kolkata 700108 (India)
2012-06-15T23:59:59.000Z
Wave packets for the quantum nonlinear oscillator are considered in the generalized coherent state framework. To first order in the nonlinearity parameter the coherent state behaves very similar to its classical counterpart. The position expectation value oscillates in a simple harmonic manner. The energy-momentum uncertainty relation is time independent as in a harmonic oscillator. Various features (such as the squeezed state nature) of the coherent state have been discussed.
Nonlinearly driven harmonics of Alfvén modes
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)] [Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)
2014-01-15T23:59:59.000Z
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.
Cabral, Marco
Harmonic Functions are Real Analytic1 On this very short note we prove that harmonic functions prove Lemma 1 using the mean value property of harmonic functions, Green's theorem and the maximum principle. Lemma 1 (estimate on first derivative) Suppose w is harmonic in Rn , > 0, y and B
Prediction of Welding Distortion Panagiotis Michaleris and Andrew DeBiccari
Michaleris, Panagiotis
1 Prediction of Welding Distortion Panagiotis Michaleris and Andrew DeBiccari Edison Welding Institute Columbus, Ohio ABSTRACT. This paper presents a numerical analysis technique for predicting welding induced distortion. The technique combines two dimensional welding simulations with three dimensional
Epitaxial growth of NiTiO3 with a distorted ilmenite structure...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
growth of NiTiO3 with a distorted ilmenite structure. Epitaxial growth of NiTiO3 with a distorted ilmenite structure. Abstract: MTiO3 (M Fe, Mn, Ni) compounds have received...
Symbolization of Map Projection Distortion: Karen A. Mulcahy and Keith C. Clarke
Clarke, Keith
of symbolization methods to match any need from basic education to research. KEYWORDS: Map projection distortion distortion characteris- tics resulting from the transformation of the globe to the flattened map. The most
Modelling Thermoelastic Distortion of Optics Using Elastodynamic Reciprocity
King, Eleanor; Veitch, Peter; Levin, Yuri
2015-01-01T23:59:59.000Z
Thermoelastic distortion resulting from optical absorption by transmissive and reflective optics can cause unacceptable changes in optical systems that employ high power beams. In advanced-generation laser-interferometric gravitational wave detectors for example, optical absorption is expected to result in wavefront distortions that would compromise the sensitivity of the detector; thus necessitating the use of adaptive thermal compensation. Unfortunately, these systems have long thermal time constants and so predictive feed-forward control systems could be required - but the finite-element analysis is computationally expensive. We describe here the use of the Betti-Maxwell elastodynamic reciprocity theorem to calculate the response of linear elastic bodies (optics) to heating that has arbitrary spatial distribution. We demonstrate using a simple example, that it can yield accurate results in computational times that are significantly less than those required for finite-element analyses.
Modelling Thermoelastic Distortion of Optics Using Elastodynamic Reciprocity
Eleanor King; Yuri Levin; David Ottaway; Peter Veitch
2015-04-17T23:59:59.000Z
Thermoelastic distortion resulting from optical absorption by transmissive and reflective optics can cause unacceptable changes in optical systems that employ high power beams. In advanced-generation laser-interferometric gravitational wave detectors for example, optical absorption is expected to result in wavefront distortions that would compromise the sensitivity of the detector; thus necessitating the use of adaptive thermal compensation. Unfortunately, these systems have long thermal time constants and so predictive feed-forward control systems could be required - but the finite-element analysis is computationally expensive. We describe here the use of the Betti-Maxwell elastodynamic reciprocity theorem to calculate the response of linear elastic bodies (optics) to heating that has arbitrary spatial distribution. We demonstrate using a simple example, that it can yield accurate results in computational times that are significantly less than those required for finite-element analyses.
CMB distortions from damping of acoustic waves produced by cosmic strings
Tashiro, Hiroyuki; Sabancilar, Eray; Vachaspati, Tanmay, E-mail: Hiroyuki.Tashiro@asu.edu, E-mail: Eray.Sabancilar@asu.edu, E-mail: tvachasp@asu.edu [Physics Department, Arizona State University, Tempe, Arizona 85287 (United States)
2013-08-01T23:59:59.000Z
We study diffusion damping of acoustic waves in the photon-baryon fluid due to cosmic strings, and calculate the induced ?- and y-type spectral distortions of the cosmic microwave background. For cosmic strings with tension within current bounds, their contribution to the spectral distortions is subdominant compared to the distortions from primordial density perturbations.
High-harmonic spectroscopy of molecular isomers
Wong, M. C. H.; Brichta, J.-P.; Bhardwaj, V. R. [Department of Physics, University of Ottawa, 150 Louis-Pasteur, Ottawa, Ontario, K1N 6N5 (Canada); Spanner, M.; Patchkovskii, S. [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6 (Canada)
2011-11-15T23:59:59.000Z
We demonstrate that high-order-harmonic generation (HHG) spectroscopy can be used to probe stereoisomers of randomly oriented 1,2-dichloroethylene (C{sub 2}H{sub 2}Cl{sub 2}) and 2-butene (C{sub 4}H{sub 8}). The high-harmonic spectra of these isomers are distinguishable over a range of laser intensities and wavelengths. Time-dependent numerical calculations of angle-dependent ionization yields for 1,2-dichloroethylene suggest that the harmonic spectra of molecular isomers reflect differences in their strong-field ionization. The subcycle ionization yields for the cis isomer are an order of magnitude higher than those for the trans isomer. The sensitivity in discrimination of the harmonic spectra of cis- and trans- isomers is greater than 8 and 5 for 1,2-dichloroethylene and 2-butene, respectively. We show that HHG spectroscopy cannot differentiate the harmonic spectra of the two enantiomers of the chiral molecule propylene oxide (C{sub 3}H{sub 6}O).
Son, Dong Hee; Wittenberg, Joshua S.; Banin, Uri; Alivisatos, A. Paul
2006-01-01T23:59:59.000Z
Second harmonic generation and confined acoustic phonons inenhancement of second harmonic generation, and the effect ofmeasurements. The second harmonic signal showed a sublinear
Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Str. 2a, D-12489 Berlin (Germany)
2010-02-15T23:59:59.000Z
Experimentally observed strong enhancement of a single high-order harmonic in harmonic generation from low-ionized laser plasma ablation is explained as resonant harmonic generation. The resonant harmonic intensity increases regularly with the increase of the laser intensity, while the phase of the resonant harmonic is almost independent of the laser intensity. This is in sharp contrast with the usual plateau and cutoff harmonics, the intensity of which exhibits wild oscillations while its phase changes rapidly with the laser intensity. The temporal profile of a group of harmonics, which includes the resonant harmonic, has the form of a broad peak in each laser-field half cycle. These characteristics of resonant harmonics can have an important application in attoscience. We illustrate our results using examples of Sn and Sb plasmas.
Plasmon signatures in high harmonic generation
J. Zanghellini; Ch. Jungreuthmayer; T. Brabec
2005-12-12T23:59:59.000Z
High harmonic generation in polarizable multi-electron systems is investigated in the framework of multi-configuration time-dependent Hartree-Fock. The harmonic spectra exhibit two cut offs. The first cut off is in agreement with the well established, single active electron cut off law. The second cut off presents a signature of multi-electron dynamics. The strong laser field excites non-linear plasmon oscillations. Electrons that are ionized from one of the multi-plasmon states and recombine to the ground state gain additional energy, thereby creating the second plateau.
Spherical Harmonic Decomposition on a Cubic Grid
Charles W. Misner
1999-10-12T23:59:59.000Z
A method is described by which a function defined on a cubic grid (as from a finite difference solution of a partial differential equation) can be resolved into spherical harmonic components at some fixed radius. This has applications to the treatment of boundary conditions imposed at radii larger than the size of the grid, following Abrahams, Rezzola, Rupright et al.(gr-qc/9709082}. In the method described here, the interpolation of the grid data to the integration 2-sphere is combined in the same step as the integrations to extract the spherical harmonic amplitudes, which become sums over grid points. Coordinates adapted to the integration sphere are not needed.
accounting standards harmonization: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
numbers were Introduced by Ore 6 In 1948, though not under that name. A natural number n is harmonic if the harmonic mean of its positive divisors is an integer....
Second Harmonic Generation Studies of Fe(II) Interactions with...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Second Harmonic Generation Studies of Fe(II) Interactions with Hematite (?-Fe2O3). Second Harmonic Generation Studies of Fe(II) Interactions with Hematite (?-Fe2O3)....
Gravitation as a Plastic Distortion of the Lorentz Vacuum
Virginia V. Fernandez; Waldyr A. Rodrigues Jr
2014-08-14T23:59:59.000Z
In this paper we present a theory of the gravitational field where this field (a kind of square root of g) is represented by a (1,1)-extensor field h describing a plastic distortion of the Lorentz vacuum (a real substance that lives in a Minkowski spacetime) due to the presence of matter. The field h distorts the Minkowski metric extensor in an appropriate way (see below) generating what may be interpreted as an effective Lorentzian metric extensor g and also it permits the introduction of different kinds of parallelism rules on the world manifold, which may be interpreted as distortions of the parallelism structure of Minkowski spacetime and which may have non null curvature and/or torsion and/or nonmetricity tensors. We thus have different possible effective geometries which may be associated to the gravitational field and thus its description by a Lorentzian geometry is only a possibility, not an imposition from Nature. Moreover, we developed with enough details the theory of multiform functions and multiform functionals that permitted us to successfully write a Lagrangian for h and to obtain its equations of motion, that results equivalent to Einstein field equations of General Relativity (for all those solutions where the manifold M is diffeomorphic to R^4. However, in our theory, differently from the case of General Relativity, trustful energy-momentum and angular momentum conservation laws exist. We express also the results of our theory in terms of the gravitational potential 1-form fields (living in Minkowski spacetime) in order to have results which may be easily expressed with the theory of differential forms. The Hamiltonian formalism for our theory (formulated in terms of the potentials) is also discussed. The paper contains also several important Appendices that complete the material in the main text.
Parametric Estimation of Harmonically Related Sinusoids
Dixit, Richa
2010-04-01T23:59:59.000Z
Mud-pulse telemetry is a method used for measurement-while-drilling (MWD)in the oil industry. The telemetry signals are corrupted by spurious mud pump noise consisting of a large number of harmonically related sinusoids. In order to denoise...
Harmonic Fluids Changxi Zheng Doug L. James
Columbia University
Harmonic Fluids Changxi Zheng Doug L. James Cornell University Abstract Fluid sounds- ing. Furthermore, while offline applications can rely on talented foley artists to "cook up" plausible for vortex-based fluid sounds [Dobashi et al. 2003] and solid bodies [O'Brien et al. 2001; James et al. 2006
Markovian evolution of strongly coupled harmonic oscillators
Chaitanya Joshi; Patrik Ohberg; James D. Cresser; Erika Andersson
2014-12-16T23:59:59.000Z
We investigate how to model Markovian evolution of coupled harmonic oscillators, each of them interacting with a local environment. When the coupling between the oscillators is weak, dissipation may be modeled using local Lindblad terms for each of the oscillators in the master equation, as is commonly done. When the coupling between oscillators is strong, this model may become invalid. We derive a master equation for two coupled harmonic oscillators which are subject to individual heat baths modeled by a collection of harmonic oscillators, and show that this master equation in general contains non-local Lindblad terms. We compare the resulting time evolution with that obtained for dissipation through local Lindblad terms for each individual oscillator, and show that the evolution is different in the two cases. In particular, the two descriptions give different predictions for the steady state and for the entanglement between strongly coupled oscillators. This shows that when describing strongly coupled harmonic oscillators, one must take great care in how dissipation is modeled, and that a description using local Lindblad terms may fail. This may be particularly relevant when attempting to generate entangled states of strongly coupled quantum systems.
Compatibility of radial, Lorenz and harmonic gauges
Elena Magliaro; Claudio Perini; Carlo Rovelli
2007-05-07T23:59:59.000Z
We observe that the radial gauge can be consistently imposed \\emph{together} with the Lorenz gauge in Maxwell theory, and with the harmonic traceless gauge in linearized general relativity. This simple observation has relevance for some recent developments in quantum gravity where the radial gauge is implicitly utilized.
Economic choices reveal probability distortion in macaque monkeys
Stauffer, William R.; Lak, Armin; Bossaerts, Peter; Schultz, Wolfram
2015-02-17T23:59:59.000Z
have identified probability distortions. The majority have 85 shown that monkeys are risk seeking for small rewards (McCoy and Platt, 2005; 86 O’Neill and Schultz, 2010; Kim et al., 2012; So and Stuphorn, 2012; Lak et al., 2014; 87... and magnitude (So 90 and Stuphorn, 2012; Raghuraman and Padoa-Schioppa, 2014), or by holding 91 probability constant and changing the magnitude (McCoy and Platt, 2005; Kim et al., 92 2012; Yamada et al., 2013; Lak et al., 2014; Stauffer et al., 2014...
One dimensional wavefront distortion sensor comprising a lens array system
Neal, Daniel R. (Tijeras, NM); Michie, Robert B. (Albuquerque, NM)
1996-01-01T23:59:59.000Z
A 1-dimensional sensor for measuring wavefront distortion of a light beam as a function of time and spatial position includes a lens system which incorporates a linear array of lenses, and a detector system which incorporates a linear array of light detectors positioned from the lens system so that light passing through any of the lenses is focused on at least one of the light detectors. The 1-dimensional sensor determines the slope of the wavefront by location of the detectors illuminated by the light. The 1 dimensional sensor has much greater bandwidth that 2 dimensional systems.
One dimensional wavefront distortion sensor comprising a lens array system
Neal, D.R.; Michie, R.B.
1996-02-20T23:59:59.000Z
A 1-dimensional sensor for measuring wavefront distortion of a light beam as a function of time and spatial position includes a lens system which incorporates a linear array of lenses, and a detector system which incorporates a linear array of light detectors positioned from the lens system so that light passing through any of the lenses is focused on at least one of the light detectors. The 1-dimensional sensor determines the slope of the wavefront by location of the detectors illuminated by the light. The 1 dimensional sensor has much greater bandwidth that 2 dimensional systems. 8 figs.
Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator
California at Santa Cruz, University of
Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator 1. The harmonic oscillator solution: displacement as a function of time We wish to solve the equation of motion for the simple harmonic oscillator shall employ for solving this di#erential equation is called the method of inspired guessing. In class
Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator
California at Santa Cruz, University of
Physics 5B Winter 2009 Solving the Simple Harmonic Oscillator 1. The harmonic oscillator solution: displacement as a function of time We wish to solve the equation of motion for the simple harmonic oscillator employ for solving this differential equation is called the method of inspired guessing. In class, we
Selective compensation of voltage harmonics in grid-connected microgrids
Vasquez, Juan Carlos
1 Selective compensation of voltage harmonics in grid-connected microgrids Mehdi Savaghebia , Juan is proposed for selective compensation of main voltage harmonics in a grid- connected microgrid. The aim level. Keywords Distributed Generator (DG); microgrid; grid-connected; voltage harmonics compensation. 1
Approximation of Harmonic Maps and Wave Maps Soren Bartels
Bartels, Soeren
Approximation of Harmonic Maps and Wave Maps SÂ¨oren Bartels Partial differential equations to certain boundary condtions. If X = then critical points u : N are called harmonic maps into N, Â·) = u0, tu(0, Â·) = v0. To approximate harmonic maps or wave maps we consider a regular triangula- tion
Isolated attosecond pulses using a detuned second-harmonic field
Neumark, Daniel M.
Isolated attosecond pulses using a detuned second-harmonic field Hamed Merdji,1,2, * Thierry 2 . The slight detuning of the second harmonic is used to break the symmetry of the electric field-order harmonics generation (HHG) of intense laser pulses in gases is attracting much attention due to both
Tracking butterfly flight paths across the landscape with harmonic radar
Northampton, University of
Tracking butterfly flight paths across the landscape with harmonic radar E. T. Cant1,*, A. D. Smith of five butterfly species were successfully tracked using harmonic radar within an agricultural landscape. Keywords: butterfly flight; harmonic radar; linear landscape features; Aglais urticae; Inachis io 1
The Harmonic Series Diverges Again and Again Steven J. Kifowit
California at Santa Cruz, University of
The Harmonic Series Diverges Again and Again Steven J. Kifowit Prairie State College Terra A. Stamps Prairie State College The harmonic series, n=1 1 n = 1 + 1 2 + 1 3 + 1 4 + 1 5 + Â· Â· Â· , is one, the harmonic series provides the instructor with a wealth of opportunities. The leaning tower of lire (Johnson
Second harmonic imaging of membrane potential of neurons with retinal
Columbia University
Second harmonic imaging of membrane potential of neurons with retinal Boaz A. Nemet Volodymyr of neurons, using the nonlinear optical phenom- enon of second harmonic generation (SHG) with a photopigment reti- nal as the chromophore [second harmonic retinal imaging of mem- brane potential (SHRIMP)]. We
Harmonic moment dynamics in Laplacian growth Alexander Leshchiner,1
Texas at Austin. University of
Harmonic moment dynamics in Laplacian growth Alexander Leshchiner,1 Matthew Thrasher,1 Mark B received 12 November 2009; published 12 January 2010 Harmonic moments are integrals of integer powers of z horizontal closely spaced plates. Harmonic moments are a natural basis for such Laplacian growth phenomena
Temporal-Harmonic Specific POD Mode Extraction Gilead Tadmor
Dabiri, John O.
Temporal-Harmonic Specific POD Mode Extraction Gilead Tadmor and Daniel Bissex Electrical changes the systems mean field changes significantly, as does the leading shedding harmonic4 , once mode pair will capture harmonically rich time dynamics, reflecting a spatial mix of multiple vortical
LMFBR fuel bundle distortion characterization using neutron tomography and potting
Betten, P.R.; Tow, D.M.
1984-05-01T23:59:59.000Z
A standard liquid metal fast breeder reactor (LMFBR) subassembly used in the Experimental Breeder Reactor II (EBRII) was investigated for fuel bundle distortion by both nondestructive and destructive methods, and the results from both methods were compared. The nondestructive method employed neutron tomography to reconstruct the locations of fuel elements through the use of a maximum entropy reconstruction algorithm known as MENT. The destructive method consisted of ''potting'' (a technique that embeds and permanently fixes the fuel elements in a solid matrix) the subassembly and then cutting and polishing the individual sections. The comparison indicated that the tomography reconstruction provided good results in describing the bundle geometry and spacer-wire locations, with the overall resolution being on the order of a spacer-wire diameter. A dimensional consistency check indicated that the element and spacer-wire dimensions were accurately reproduced in the reconstruction. It was found that in situ fuel elements deform axially in a helical spiral and that the reconstruction was able to identify this helical distortion to within approximately half of a spacerwire diameter.
Pipe-type cable ampacities in the presence of harmonics
Palmer, J.A.; Degeneff, R.C. (Rensselaer Polytechnic Inst., Troy, NY (United States)); McKernan, T.M.; Halleran, T.M. (Consolidated Edison Co. of NY, Inc., New York, NY (United States))
1993-10-01T23:59:59.000Z
This paper explores the effect of harmonics on HPFF pipe-type transmission cable ampacity. Industry currently calculates the current carrying capacity of underground cable based on the assumption of a purely sinusoidal 60k Hz. current. However, increasing levels of harmonics on power systems have raised concern about their effect on cable ampacities. The issue has already been addressed for distribution cables. This paper begins with a discussion of Neher and McGrath's classic equations and some recent revisions, and develops a closed form composite equations accurately reflecting the effect of harmonics. The effect of frequency on the loss ratio is shown and supported by comparison with measured data at 60 Hz. and a finite element analysis at a number of harmonic frequencies. The effect of specific harmonic scenarios is shown in light of the IEEE standard on harmonics. The results are used to develop a derating factor to compensate for current harmonics on transmission systems.
Generalized harmonic formulation in spherical symmetry
Evgeny Sorkin; Matthew W. Choptuik
2010-04-30T23:59:59.000Z
In this pedagogically structured article, we describe a generalized harmonic formulation of the Einstein equations in spherical symmetry which is regular at the origin. The generalized harmonic approach has attracted significant attention in numerical relativity over the past few years, especially as applied to the problem of binary inspiral and merger. A key issue when using the technique is the choice of the gauge source functions, and recent work has provided several prescriptions for gauge drivers designed to evolve these functions in a controlled way. We numerically investigate the parameter spaces of some of these drivers in the context of fully non-linear collapse of a real, massless scalar field, and determine nearly optimal parameter settings for specific situations. Surprisingly, we find that many of the drivers that perform well in 3+1 calculations that use Cartesian coordinates, are considerably less effective in spherical symmetry, where some of them are, in fact, unstable.
Prolate spheroidal harmonic expansion of gravitational field
Fukushima, Toshio, E-mail: Toshio.Fukushima@nao.ac.jp [National Astronomical Observatory, Ohsawa, Mitaka, Tokyo 181-8588 (Japan)
2014-06-01T23:59:59.000Z
As a modification of the oblate spheroidal case, a recursive method is developed to compute the point value and a few low-order derivatives of the prolate spheroidal harmonics of the second kind, Q{sub nm} (y), namely the unnormalized associated Legendre function (ALF) of the second kind with its argument in the domain, 1 < y < ?. They are required in evaluating the prolate spheroidal harmonic expansion of the gravitational field in addition to the point value and the low-order derivatives of P-bar {sub nm}(t), the 4? fully normalized ALF of the first kind with its argument in the domain, |t| ? 1. The new method will be useful in the gravitational field computation of elongated celestial objects.
Harmonic polylogarithms for massive Bhabha scattering
M. Czakon; J. Gluza; T. Riemann
2005-08-19T23:59:59.000Z
One- and two-dimensional harmonic polylogarithms, HPLs and GPLs, appear in calculations of multi-loop integrals. We discuss them in the context of analytical solutions for two-loop master integrals in the case of massive Bhabha scattering in QED. For the GPLs we discuss analytical representations, conformal transformations, and also their transformations corresponding to relations between master integrals in the s- and t-channel.
${\\cal D}$-deformed harmonic oscillators
F. Bagarello; F. Gargano; D. Volpe
2014-12-30T23:59:59.000Z
We analyze systematically several deformations arising from two-dimensional harmonic oscillators which can be described in terms of $\\cal{D}$-pseudo bosons. They all give rise to exactly solvable models, described by non self-adjoint hamiltonians whose eigenvalues and eigenvectors can be found adopting the quite general framework of the so-called $\\cal{D}$-pseudo bosons. In particular, we show that several models previously introduced in the literature perfectly fit into this scheme.
Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W; Turner, A E; Whitney, R R
1982-09-01T23:59:59.000Z
Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should be tested further. For the measurement method, more testing should be done to cover different system operating conditions. In the analytical method, more detailed models for representing system components should be studied. In addition, alternative statistical and sensitivity approaches should be attempted.
BLIND COMPENSATION OF NONLINEAR DISTORTIONS VIA SPARSITY RECOVERY Leonardo T. Duarte1
Paris-Sud XI, Université de
BLIND COMPENSATION OF NONLINEAR DISTORTIONS VIA SPARSITY RECOVERY Leonardo T. Duarte1 , Ricardo.jutten@gipsa-lab.grenoble-inp.fr ABSTRACT In this work, we address the problem of compensating a non- linear memoryless system in a blind a representative set of experiments on synthetic data. Index Terms-- Blind compensation, nonlinear distortion
Blind Compensation of Nonlinear Distortions : Application to Source Separation of Post-Nonlinear
Paris-Sud XI, Université de
1 Blind Compensation of Nonlinear Distortions : Application to Source Separation of Post of blind compensation of nonlinear distortions. Our approach relies on the assumption that the input approached is considered in the development of a two-stage method for blind source separation (BSS) in post
SERVER DIVERSITY IN RATE-DISTORTION OPTIMIZED MEDIA STREAMING Jacob Chakareski*
Girod, Bernd
SERVER DIVERSITY IN RATE-DISTORTION OPTIMIZED MEDIA STREAMING Jacob Chakareski* and Bernd Girod framework. Diversity is achieved by requesting media packets from multiple servers. A framework is proposed and from which servers in order to meet a rate constraint while minimizing the end-to- end distortion
Virtually distortion-free imaging system for large field, high resolution lithography
Hawryluk, A.M.; Ceglio, N.M.
1993-01-05T23:59:59.000Z
Virtually distortion free large field high resolution imaging is performed using an imaging system which contains large field distortion or field curvature. A reticle is imaged in one direction through the optical system to form an encoded mask. The encoded mask is then imaged back through the imaging system onto a wafer positioned at the reticle position.
MULTIZONE NEAR-END SPEECH ENHANCEMENT UNDER OPTIMAL SECOND-ORDER MAGNITUDE DISTORTION
MULTIZONE NEAR-END SPEECH ENHANCEMENT UNDER OPTIMAL SECOND-ORDER MAGNITUDE DISTORTION Jo~ao B.c.hendriks@tudelft.nl ABSTRACT In this article, we address near-end speech enhancement for a sce- nario where there are several-end speech enhancement, multizone, second-order magnitude distortion, public address system 1. INTRODUCTION
A sex-ratio Meiotic Drive System in Drosophila simulans. II: An X-linked Distorter
Hartl, Daniel L.
-ratio distorter on the X chromosome (Dox) in Drosophila simulans by genetic and molecular means. Intriguingly, Dox. Through retrotransposition, Dox also gave rise to an autosomal suppressor, not much yang (Nmy). An RNA interference mechanism seems to be involved in the suppression of the Dox distorter by the Nmy suppressor
Wang, Lihong
Image distortion in thermoacoustic tomography caused by microwave diffraction Changhui Li,* Manojit-induced thermoacoustic tomography. The distortion, due to microwave diffraction in the object to be imaged, leads Thermoacoustic TA tomography TAT in biological tis- sue reconstructs the TA source distribution from the acoustic
Inter-frame dependent rate and distortion models for statistical multiplexing of video programs
Paris-Sud XI, Université de
Inter-frame dependent rate and distortion models for statistical multiplexing of video programs@lss.supelec.fr Abstract--Statistical multiplexing (SM) is a useful technique for transmitting multiple video streams over of efficient SM algorithms is based on Rate and Distortion (R-D) information extracted from successive encoded
PREDICTION OF HEAT TREATMENT DISTORTION OF CAST STEEL C-RINGS
Beckermann, Christoph
PREDICTION OF HEAT TREATMENT DISTORTION OF CAST STEEL C-RINGS Brandon Elliott Brooks1 and Christoph extensive rework or redesign, recasting, or through additional machining steps. Predicting heat treatment. There has been extensive interest in the prediction of heat treatment distortion via computer simulation
Matrix Decomposition-Based Data Distortion Techniques for Privacy Preservation in Data Mining
Zhang, Jun
. The second is to modify the data mining algorithms so that they allow data mining operations on distributedMatrix Decomposition-Based Data Distortion Techniques for Privacy Preservation in Data Mining Jun-Based Data Distortion Techniques for Privacy Preservation in Data Mining Jun Zhang and Jie Wang, University
A numerical model for the acoustic prediction of a propeller under distorted inflow conditions
Uellenberg, Stefan
1993-01-01T23:59:59.000Z
for the nth harmonic Loading pressure for the nth harmonic Dynamic pressure due to the helical velocity Radial Postion Vector from source to observer Unit vector from source to observer Complex Sears function SPL Complex Compressible Sears function..., Ms, t = 0. 95, at r = 10. 0 m, snd z = -0. 122 m. a) Theoretical Acoustic Time Histories b) Frequency Spectra Comparisons between Succi, and Kirchhoff 46 17 Steady Results for First Four Harmonics in the Disk Plane from One to Five Propeller Radii...
Transition to the Relativistic Regime in High Order Harmonic Generation
Tarasevitch, Alexander; Lobov, Konstantin; Wuensche, Clemens; Linde, Dietrich von der [Institut fuer Experimentelle Physik, Universitaet Duisburg-Essen, D-47048 Duisburg (Germany)
2007-03-09T23:59:59.000Z
Experiments and computer simulations on the generation of high order harmonics from steep plasma gradients using intense femtosecond laser pulses are presented. Qualitative changes in the harmonic emission take place when the intensities are increased above 10{sup 19} W/cm{sup 2} and/or the plasma scale length is varied. Good agreement between experimental and calculated spectra makes it possible to clearly distinguish between nonrelativistic and relativistic mechanisms of harmonic generation.
alternating phase harmonic: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the effects of harmonics on their systems: telephone noise, excessive heating of transformers and other equipment, capacitor damage, and others, and would like to limit the...
Simple connection between Faddeev's and the K-harmonic approaches
Coelho, H.T.; Gloeckle, W.; Delfino, A.
1980-10-01T23:59:59.000Z
By employing a system for three bound identical bosons, a simple connection is made between Faddeev's and the K-harmonic approaches.
Algal Supply System Design - Harmonized Version
Abodeely, Jared; Stevens, Daniel; Ray, Allison; Newby, Deborah; Schaller, Kastli
2013-03-01T23:59:59.000Z
The objective of this design report is to provide an assessment of current technologies used for production, dewatering, and converting microalgae cultivated in open-pond systems to biofuel. The original draft design was created in 2011 and has subsequently been brought into agreement with the DOE harmonized model. The design report extends beyond this harmonized model to discuss some of the challenges with assessing algal production systems, including the ability to (1) quickly assess alternative algal production system designs, (2) assess spatial and temporal variability, and (3) perform large-scale assessments considering multiple scenarios for thousands of potential sites. The Algae Logistics Model (ALM) was developed to address each of these limitations of current modeling efforts to enable assessment of the economic feasibility of algal production systems across the United States. The (ALM) enables (1) dynamic assessments using spatiotemporal conditions, (2) exploration of algal production system design configurations, (3) investigation of algal production system operating assumptions, and (4) trade-off assessments with technology decisions and operating assumptions. The report discusses results from the ALM, which is used to assess the baseline design determined by harmonization efforts between U.S. DOE national laboratories. Productivity and resource assessment data is provided by coupling the ALM with the Biomass Assessment Tool developed at PNNL. This high-fidelity data is dynamically passed to the ALM and used to help better understand the impacts of spatial and temporal constraints on algal production systems by providing a cost for producing extracted algal lipids annually for each potential site.
Harmonic pinnacles in the Discrete Gaussian model
Eyal Lubetzky; Fabio Martinelli; Allan Sly
2014-05-20T23:59:59.000Z
The 2D Discrete Gaussian model gives each height function $\\eta : \\mathbb{Z}^2\\to\\mathbb{Z}$ a probability proportional to $\\exp(-\\beta \\mathcal{H}(\\eta))$, where $\\beta$ is the inverse-temperature and $\\mathcal{H}(\\eta) = \\sum_{x\\sim y}(\\eta_x-\\eta_y)^2$ sums over nearest-neighbor bonds. We consider the model at large fixed $\\beta$, where it is flat unlike its continuous analog (the Gaussian Free Field). We first establish that the maximum height in an $L\\times L$ box with 0 boundary conditions concentrates on two integers $M,M+1$ with $M\\sim \\sqrt{(1/2\\pi\\beta)\\log L\\log\\log L}$. The key is a large deviation estimate for the height at the origin in $\\mathbb{Z}^2$, dominated by "harmonic pinnacles", integer approximations of a harmonic variational problem. Second, in this model conditioned on $\\eta\\geq 0$ (a floor), the average height rises, and in fact the height of almost all sites concentrates on levels $H,H+1$ where $H\\sim M/\\sqrt{2}$. This in particular pins down the asymptotics, and corrects the order, in results of Bricmont, El-Mellouki and Fr\\"ohlich (1986), where it was argued that the maximum and the height of the surface above a floor are both of order $\\sqrt{\\log L}$. Finally, our methods extend to other classical surface models (e.g., restricted SOS), featuring connections to $p$-harmonic analysis and alternating sign matrices.
Harmonic-Oscillator-Based Effective Theory
W. C. Haxton
2006-08-06T23:59:59.000Z
I describe harmonic-oscillator-based effective theory (HOBET) and explore the extent to which the effects of excluded higher-energy oscillator shells can be represented by a contact-gradient expansion in next-to-next-to-leading order (NNLO). I find the expansion can be very successful provided the energy dependence of the effective interaction, connected with missing long-wavelength physics associated with low-energy breakup channels, is taken into account. I discuss a modification that removes operator mixing from HOBET, simplifying the task of determining the parameters of an NNLO interaction.
Harmon, Illinois: Energy Resources | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetec AG| OpenInformation Handbook forHansung ANewHardyCounty,Harmon,
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolÃ©(tm) Harmonic Engine GyroSolÃ©(tm) engine * Simple * Efficient
Limitations and improvements for harmonic generation measurements
Best, Steven; Croxford, Anthony; Neild, Simon [Department of Mechanical Engineering, Queens Building, University Walk, Bristol BS8 1TR (United Kingdom)
2014-02-18T23:59:59.000Z
A typical acoustic harmonic generation measurement comes with certain limitations. Firstly, the use of the plane wave-based analysis used to extract the nonlinear parameter, ?, ignores the effects of diffraction, attenuation and receiver averaging which are common to most experiments, and may therefore limit the accuracy of a measurement. Secondly, the method usually requires data obtained from a through-transmission type setup, which may not be practical in a field measurement scenario where access to the component is limited. Thirdly, the technique lacks a means of pinpointing areas of damage in a component, as the measured nonlinearity represents an average over the length of signal propagation. Here we describe a three-dimensional model of harmonic generation in a sound beam, which is intended to provide a more realistic representation of a typical experiment. The presence of a reflecting boundary is then incorporated into the model to assess the feasibility of performing single-sided measurements. Experimental validation is provided where possible. Finally, a focusing acoustic source is modelled to provide a theoretical indication of the afforded advantages when the nonlinearity is localized.
Design study of the bending sections between harmonic cascade FEL stages
Wan, Weishi; Corlett, John; Fawley, William; Zholents, A.
2004-01-01T23:59:59.000Z
A XUV/Soft X-Ray Harmonic- Cascade FEL for the Proposed LBNLin a Cascaded Harmonic FEL CBP Tech Note-281, Februarybetween Harmonic Cascade FEL Stages W. Wan, J. Corlett, W.
Complex harmonic wave scattering asthe framework for investigation of bounded beam reflection their pro- files.We will verifythesestatementswith a largenumberof illustrations. I. COMPLEX HARMONIC WAVE REFLECTION AND TRANSMISSION A. Representation of a complex harmonic wave in a viscoelastic medium
Antonietta Vincenti, Maria; Campione, Salvatore; de Ceglia, Domenico; Capolino, Filippo; Scalora, Michael
2012-01-01T23:59:59.000Z
from metal shells 3.1. Second-harmonic generation from gold3.2. Third-harmonic generation from golddriven second- and third-harmonic generation at ?-near-zero
Nelson, Christopher Scott; Nelson, Christopher Scott
2012-01-01T23:59:59.000Z
3.2 Simple Cases of Non-Commutative -Harmonic Polyno-3.2.2 1-Harmonic Polynomials . . . . . . . . . . .1.2.1 Non-Commutative Harmonic and Subharmonic Poly-
North-South Standards Harmonization and International Trade
Paris-Sud XI, Université de
North-South Standards Harmonization and International Trade Olivier CADOT Lausanne University Anne,version1-20Mar2014 #12;1 North-South Standards Harmonization and International Trade Anne-Célia Disdier investigate whether the technical requirements contained in North-South Agreements affect international trade
Power line harmonic radiation (PLHR) observed by the DEMETER spacecraft
Santolik, Ondrej
Power line harmonic radiation (PLHR) observed by the DEMETER spacecraft F. Nemec,1,2 O. SantoliÂ´k,3 January 2006; published 22 April 2006. [1] Results of a systematic survey of Power Line Harmonic Radiation from the electric power systems which are magnetically conjugated with the place of observation
Power line harmonic radiation: A systematic study using DEMETER spacecraft
Santolik, Ondrej
Power line harmonic radiation: A systematic study using DEMETER spacecraft F. Nemec a,b,*, O of a systematic survey of Power line harmonic radiation (PLHR) observed by the DEMETER spacecraft. DEME- TER frequency spacing corresponds well to the power system frequency at anticipated source locations. Moreover
Propagation of nonlinearly generated harmonic spin waves in microscopic stripes
Otani, Yoshichika
Propagation of nonlinearly generated harmonic spin waves in microscopic stripes O. Rousseau,1 M on the experimental study of the propagation of nonlinearly generated harmonic spin waves in microscopic CoFeB stripes wave propagation. VC 2014 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4864480] In recent years
Harmonic minimization waveforms for modulated heating experiments at HAARP
Harmonic minimization waveforms for modulated heating experiments at HAARP G. Jin,1 M. Spasojevic,1), Harmonic minimization waveforms for modulated heating experiments at HAARP, J. Geophys. Res., 117, A11315 and Stubbe [1984], and Milikh et al. [1999]. The High Fre- quency Active Auroral Research Program (HAARP
Higher order harmonic detection for exploring nonlinear interactions
Vasudevan, Rama K [ORNL; Okatan, M. B. [University of New South Wales; Rajapaksa, Indrajit [Oak Ridge National Laboratory (ORNL); Kim, Yunseok [ORNL; Marincel, Dan [Materials Science and Engineering, Pennsylvania State University; Trolier-McKinstry, Susan [Pennsylvania State University; Jesse, Stephen [ORNL; Nagarajan, Valanoor [University of New South Wales; Kalinin, Sergei V [ORNL
2013-01-01T23:59:59.000Z
Nonlinear dynamics underpin a vast array of physical phenomena ranging from interfacial motion to jamming transitions. In many cases, decoupling the contributions of competing or co-existing mechanisms to the system response can be achieved through investigation of higher order harmonics. Here, a method using band excitation scanning probe microscopy to investigate higher order harmonics of the electromechanical response, with nanometer scale spatial resolution is presented. The utility of the technique is demonstrated by probing the first three harmonics of strain for a well-known system, a model Pb(Zr1-xTix)O3 ferroelectric capacitor. It is shown that the second order harmonic response is correlated with the first harmonic response, whereas the third harmonic is not. Additionally, nanoscale measurements of the second harmonic response with field reveal significant deviations from Rayleigh-type models in the form of a much more complicated field dependence than is observed in the spatially averaged data. These results illustrate the versatility of combining proximal probe techniques with nth harmonic detection methods in exploring and decoupling nonlinear dynamics in a wide variety of nanoscale materials.
How to measure redshift-space distortions without sample variance
Patrick McDonald; Uros Seljak
2008-10-02T23:59:59.000Z
We show how to use multiple tracers of large-scale density with different biases to measure the redshift-space distortion parameter beta=f/b=(dlnD/dlna)/b (where D is the growth rate and a the expansion factor), to a much better precision than one could achieve with a single tracer, to an arbitrary precision in the low noise limit. In combination with the power spectrum of the tracers this allows a much more precise measurement of the bias-free velocity divergence power spectrum, f^2 P_m - in fact, in the low noise limit f^2 P_m can be measured as well as would be possible if velocity divergence was observed directly, with rms improvement factor ~[5.2(beta^2+2 beta+2)/beta^2]^0.5 (e.g., ~10 times better than a single tracer for beta=0.4). This would allow a high precision determination of f D as a function of redshift with an error as low as 0.1%. We find up to two orders of magnitude improvement in Figure of Merit for the Dark Energy equation of state relative to Stage II, a factor of several better than other proposed Stage IV Dark Energy surveys. The ratio b_2/b_1 will be determined with an even greater precision than beta, producing, when measured as a function of scale, an exquisitely sensitive probe of the onset of non-linear bias. We also extend in more detail previous work on the use of the same technique to measure non-Gaussianity. Currently planned redshift surveys are typically designed with signal to noise of unity on scales of interest, and are not optimized for this technique. Our results suggest that this strategy may need to be revisited as there are large gains to be achieved from surveys with higher number densities of galaxies.
Spectrum of second-harmonic radiation generated from incoherent light
Stabinis, A.; Pyragaite, V.; Tamosauskas, G.; Piskarskas, A. [Department of Quantum Electronics, Vilnius University, Sauletekio Avenue 9, Building 3, LT-10222 Vilnius (Lithuania)
2011-10-15T23:59:59.000Z
We report on the development of the theory of second-harmonic generation by an incoherent pump with broad angular and frequency spectra. We show that spatial as well as temporal walk-off effects in a nonlinear crystal result in angular dispersion of the second-harmonic radiation. We demonstrate that the acceptance angle in second-harmonic generation by incoherent light is caused by the width of the pump angular spectrum and the resulting angular dispersion of second-harmonic radiation but does not depend on crystal length. In this case the frequency spectrum of second-harmonic radiation is determined by its angular dispersion and the pump angular spectrum. The theory is supported by an experiment in which a LiIO{sub 3} crystal was pumped by a tungsten halogen lamp.
Commissioning of a higher harmonic RF system for the Advanced Light Source
Byrd, John M.; De Santis, Stefano; Georgsson, Mattias; Stover, G.; Fox, John D.; Teytelman, Dmitry
2000-01-01T23:59:59.000Z
Commissioning of a higher harmonic RF system for theAbstract We report on the commissioning of a higher harmonicpresents the results of commissioning of the ALS harmonic
Hierarchical Control Scheme for Voltage Harmonics Compensation in an Islanded Droop-
Vasquez, Juan Carlos
Hierarchical Control Scheme for Voltage Harmonics Compensation in an Islanded Droop- Controlled on the resistance emulation. Furthermore, a droop characteristic based on DG harmonic reactive power has been
Relativistic harmonic oscillator model for quark stars
Vishnu M. Bannur
2008-10-06T23:59:59.000Z
The relativistic harmonic oscillator (RHO) model of hadrons is used to study quark stars. The mass-radius relationship is obtained and compared with bag model of quark star, using Tolman-Oppenheimer-Volkoff equation. In this model, the outward degenerate pressure due to discrete Landau levels and Landau degeneracy balances the inward gravitational pressure. Where as in bag model the degenerate pressure is due to the standard continuum levels which balances the combined inward pressure due to gravitation and bag pressure. So in RHO model, the confinement effect is included in the degenerate pressure. We found a qualitative similarity, but quantitative differences in mass-radius relationship of quark stars in these two models. Masses and radii are relatively larger and the central energy densities, required for stable quark stars, are lower in RHO model than that of bag model.
Xiang, D.; Colby, E.; Dunning, M.; Gilevich, S.; Hast, C.; Jobe, K.; McCormick, D.; Nelson, J.; Raubenheimer, T.O.; Soong, K.; Stupakov, G.; Szalata, Z.; Walz, D.; Weathersby, S.; Woodle, M.; /SLAC; ,
2012-02-15T23:59:59.000Z
Echo-enabled harmonic generation free electron lasers hold great promise for the generation of fully coherent radiation in x-ray wavelengths. Here we report the first evidence of high harmonics from the echo-enabled harmonic generation technique in the realistic scenario where the laser energy modulation is comparable to the beam slice energy spread. In this experiment, coherent radiation at the seventh harmonic of the second seed laser is generated when the energy modulation amplitude is about 2-3 times the slice energy spread. The experiment confirms the underlying physics of echo-enabled harmonic generation and may have a strong impact on emerging seeded x-ray free electron lasers that are capable of generating laserlike x rays which will advance many areas of science.
Maduri, Rajesh Kumar
2008-02-01T23:59:59.000Z
The primary focus of this thesis is to present a framework to develop higher order global differentiability local approximations for 2-D and 3-D distorted element geometries. The necessity and superiority of higher order global differentiability...
Progress in studies of Electron-Cloud-Induced Optics Distortions at CESRTA
Crittenden, J.A.
2010-01-01T23:59:59.000Z
OF ELECTRON-CLOUD-INDUCED OPTICS DISTORTIONS AT CESRTA J.A.beam emittance, lattice optics,and the secondary-electronlinear colliders. linear optics arising from electron cloud
A restoration model of distorted electron density in wave-cutoff probe measurement
Jun, Hyun-Su, E-mail: mtsconst@kaist.ac.kr; Lee, Yun-Seong [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)] [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of)
2014-02-15T23:59:59.000Z
This study investigates the problem of electron density distortion and how the density can be restored in a wave-cutoff probe. Despite recent plasma diagnostics research using a wave-cutoff probe, the problem of electron density distortion caused by plasma conditions has not been resolved. Experimental results indicate that electron density measured using the wave-cutoff method is highly susceptible to variations in the probe tip gap. This electron density distortion is caused by the bulk plasma disturbance between probe tips, and it must be removed for calculating the absolute electron density. To do this, a detailed analytic model was developed using the power balance equation near probe tips. This model demonstrates the characteristics of plasma distortion in wave-cutoff probe measurement and successfully restored the absolute value of electron density with varying probe tip gaps.
6 Equalization of Channels with ISI Many practical channels are bandlimited and linearly distort the
Pulfrey, David L.
244 6 Equalization of Channels with ISI Many practical channels are bandlimited and linearly distort the transmit signal. In this case, the resulting ISI channel has to be equalized for reliable
Using Graph Theory and a Plenoptic Sensor to Recognize Phase Distortions of a Laser Beam
Wu, Chensheng; Davis, Christopher C
2015-01-01T23:59:59.000Z
Atmospheric turbulence causes fluctuations in the local refractive index of air that accumulatively disturb a wave's phase and amplitude distribution as it propagates. This impairs the effective range of laser weapons as well as the performance of free space optical (FSO) communication systems. Adaptive optics (AO) can be applied to effectively correct wavefront distortions in weak turbulence situations. However, in strong or deep turbulence, where scintillation and beam breakup are common phenomena, traditional wavefront sensing techniques such as the use of Shack-Hartmann sensors lead to incorrect results. Consequently, the performance of AO systems will be greatly compromised. We propose a new approach that can determine the major phase distortions in a beam instantaneously and guide an AO device to compensate for the phase distortion in a few iterations. In our approach, we use a plenoptic wavefront sensor to image the distorted beam into its 4D phase space. A fast reconstruction algorithm based on graph ...
Birge, Jonathan R.
The optimization of phase distortion spectral power density is proposed as an alternative to GDD minimization of ultrafast cavity mirrors. This criterion is shown to minimize the detuning of cavity resonances from a uniform comb.
Relative stereociliary motion in a hair bundle opposes amplification at distortion frequencies
Andrei S. Kozlov; Thomas Risler; Armin J. Hinterwirth; A. J. Hudspeth
2012-03-08T23:59:59.000Z
Direct gating of mechanoelectrical-transduction channels by mechanical force is a basic feature of hair cells that assures fast transduction and underpins the mechanical amplification of acoustic inputs. But the associated nonlinearity - the gating compliance - inevitably distorts signals. Because reducing distortion would make the ear a better detector, we sought mechanisms with that effect. Mimicking in vivo stimulation, we used stiff probes to displace individual hair bundles at physiological amplitudes and measured the coherence and phase of the relative stereociliary motions with a dual-beam differential interferometer. Although stereocilia moved coherently and in phase at the stimulus frequencies, large phase lags at the frequencies of the internally generated distortion products indicated dissipative relative motions. Tip links engaged these relative modes and decreased the coherence in both stimulated and free hair bundles. These results show that a hair bundle breaks into a highly dissipative serial arrangement of stereocilia at distortion frequencies, precluding their amplification.
SU(4) harmonic superspace and supersymmetric gauge theory
B. M. Zupnik
2014-10-10T23:59:59.000Z
We consider the harmonic-superspace formalism in the $N=4$ supersymmetry using the $SU(4)/SU(2)\\times SU(2)\\times U(1)$ harmonics which was earlier applied to the abelian gauge theory. The N=4 non-abelian constraints in a standard superspace are reformulated as the harmonic-superspace equations for two basic analytic superfields: the independent superfield strength W of a dimension 1 and the dimensionless harmonic gauge 4-prepotential V having the $U(1)$ charge 2. These constraint equations I manifestly depend on the Grassmann coordinates $\\theta$, although they are covariant under the unusual N=4 supersymmetry transformations. We analyze an alternative harmonic formalism of the supergauge theory for two unconstrained nonabelian analytic superfields W and V. The gauge-invariant action A(W,V) in this formalism contains $\\theta$ factors in each term, it is invariant under the $SU(4)$ automorphism group. In this model, the interaction of two infinite-dimensional N=4 supermultiplets with the physical and auxiliary fields arises at the level of component fields. The action A(W,V) generate analytic equations of motion II alternative to the harmonic-superspace superfield constraints I. Both sets of equations give us the equivalent equations for the physical component fields of the $N=4$ gauge supermultiplet, they connect auxiliary and physical fields of two superfields. The nonlinear effective interaction of the abelian harmonic superfield W is constructed.
Relativistic high harmonic generation in gas jet targets
Pirozhkov, A.S.; Kando, M.; Esirkepov, T.Zh.; and others
2012-07-11T23:59:59.000Z
We experimentally demonstrate a new regime of high-order harmonic generation by relativistic-irradiance lasers in gas jet targets. Bright harmonics with both odd and even orders, generated by linearly as well as circularly polarized pulses, are emitted in the forward direction, while the base harmonic frequency is downshifted. A 9 TW laser generates harmonics up to 360 eV, within the 'water window' spectral region. With a 120 TW laser producing 40 uJ/sr per harmonic at 120 eV, we demonstrate the photon number scalability. The observed harmonics cannot be explained by previously suggested scenarios. A novel high-order harmonics generation mechanism [T. Zh. Esirkepov et al., AIP Proceedings, this volume], which explains our experimental findings, is based on the phenomena inherent in the relativistic laser - underdense plasma interactions (self-focusing, cavity evacuation, and bow wave generation), mathematical catastrophe theory which explains formation of electron density singularities (cusps), and collective radiation due to nonlinear oscillations of a compact charge.
Second harmonic effect on geodesic modes in tokamak plasmas
Elfimov, A. G.; Galvão, R. M. O. [Institute of Physics, University of São Paulo, São Paulo 05508-090 (Brazil)] [Institute of Physics, University of São Paulo, São Paulo 05508-090 (Brazil); Smolyakov, A. I. [University of Saskatchewan, 116 Science Place, Saskatoon S7N 5E2 (Canada) [University of Saskatchewan, 116 Science Place, Saskatoon S7N 5E2 (Canada); Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow (Russian Federation); Melnikov, A. V. [Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow (Russian Federation)] [Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow (Russian Federation)
2013-05-15T23:59:59.000Z
Results of a kinetic treatment of Geodesic Acoustic Modes (GAMs) that fully takes into account ion parallel dynamics, including the magnetic field component, are presented. The finite-orbit-width (FOW) parameter is considered in the calculation of the second harmonic effect on GAMs. For larger values of the FOW parameter, it is shown that dispersive effects related to the m = 2 harmonics is the cause of the mode frequency splitting and the modes appear due to the interaction with the ion sound mode. Furthermore, the modes may have enhanced damping rates due to second harmonic Landau damping.
Harmonic measurements from a group connected generator HVdc converter scheme
Macdonald, S.J.; Enright, W.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand)] [Univ. of Canterbury, Christchurch (New Zealand); O`Brien, M.T.
1995-10-01T23:59:59.000Z
A recent CIGRE document published in ELECTRA has described the potential benefits of a direct connection of generators to HVdc converters. While many theoretical contributions have been made, no practical test data has become available so far. This paper reports on harmonic tests carried out at the Benmore end of the New Zealand HVdc link operating as a group connected scheme. It was found that the measured harmonic current levels were well below specified generator ratings. Dynamic simulation accurately predicted the harmonic currents whereas the results of a steady state formulation were less reliable.
Generalized Harmonic Equations in 3+1 Form
J. David Brown
2011-11-29T23:59:59.000Z
The generalized harmonic equations of general relativity are written in 3+1 form. The result is a system of partial differential equations with first order time and second order space derivatives for the spatial metric, extrinsic curvature, lapse function and shift vector, plus fields that represent the time derivatives of the lapse and shift. This allows for a direct comparison between the generalized harmonic and the Arnowitt-Deser-Misner formulations. The 3+1 generalized harmonic equations are also written in terms of conformal variables and compared to the Baumgarte-Shapiro-Shibata-Nakamura equations with moving puncture gauge conditions.
High order harmonic generation in dual gas multi-jets
Tosa, Valer, E-mail: valer.tosa@itim-cj.ro, E-mail: calin.hojbota@itim-cj.ro; Hojbota, Calin, E-mail: valer.tosa@itim-cj.ro, E-mail: calin.hojbota@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath 65-103, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, Donath 65-103, 400293 Cluj-Napoca (Romania)
2013-11-13T23:59:59.000Z
High order harmonic generation (HHG) in gas media suffers from a low conversion efficiency that has its origins in the interaction of the atom/molecule with the laser field. Phase matching is the main way to enhance the harmonic flux and several solutions have been designed to achieve it. Here we present numerical results modeling HHG in a system of multi-jets in which two gases alternate: the first gas jet (for example Ne) generates harmonics and the second one which ionizes easier, recover the phase matching condition. We obtain configurations which are experimentally feasible with respect to pressures and dimensions of the jets.
Harmonic Superspace Gaugeon Formalism for the ABJM Theory
Mir Faizal
2012-07-12T23:59:59.000Z
In this paper we will analyse the ABJM theory in harmonic superspace. The harmonic superspace variables will be parameterized by the coset $SU(2)/U(1)$ and thus will have manifest $\\mathcal{N} =3$ supersymmetry. We will study the quantum gauge transformations and the BRST transformations of this theory in gaugeon formalism. We will use this BRST symmetry to project out the physical sub-space from the total Hilbert space. We will also show that the evolution of the $\\mathcal{S}$-matrix is unitary for this ABJM theory in harmonic superspace.
ASYMPTOTIC DISTRIBUTION OF ESTIMATES FOR A TIME-VARYING PARAMETER IN A HARMONIC MODEL
Irizarry, Rafael A.
ASYMPTOTIC DISTRIBUTION OF ESTIMATES FOR A TIME-VARYING PARAMETER IN A HARMONIC MODEL WITH MULTIPLE harmonic regression models are useful for cases where harmonic parameters appear to be time-varying. Least, harmonic regression, signal processing, sound analysis, time-varying parameters, weighted least squares
Harmonic Content of Strain-induced Potential Modulation in Unidirectional Lateral Superlattices
Katsumoto, Shingo
Harmonic Content of Strain-induced Potential Modulation in Unidirectional Lateral Superlattices from a Â¼ 92 to 184 nm. Fourier analysis reveals the second (and the third) harmonics along of corresponding harmonics in the profile of the potential modulation. The harmonics manifest themselves in CO
Inverse medium scattering for three-dimensional time harmonic ...
2004-01-22T23:59:59.000Z
Jan 22, 2004 ... problem of time harmonic Maxwell equations in R3. ..... For a simple stability analysis, some relative random noise is added to the data, e.g., the.
Interference-Aware Geometric Modeling David Harmon1
Grinspun, Eitan
Interference-Aware Geometric Modeling David Harmon1 Daniele Panozzo1,2 Olga Sorkine1,3 Denis Zorin1 as glaring artifacts, and eliminate the ability to use the final model further down many software pipelines
Time-optimal controls for frictionless cooling in harmonic traps
Salamon, Peter
OFFPRINT Time-optimal controls for frictionless cooling in harmonic traps K. H. Hoffmann, P payment Details on preparing, submitting and tracking the progress of your manuscript from submission
Classification of Certain Compact Riemannian Manifolds with Harmonic Curvature a...
Derdzinski, Andrzej
Classification of Certain Compact Riemannian Manifolds with Harmonic Curvature a... Derdzinski and University Library provides access to digitized documents strictly for noncommercial educational, research) requires prior written permission from the Goettingen State- and University Library. Each copy of any part
Electric shock and elevated EMF levels due to triplen harmonics
Tran, T.Q.; Conrad, L.E.; Stallman, B.K. [PSI Energy, Inc., Plainfield, IN (United States)] [PSI Energy, Inc., Plainfield, IN (United States)
1996-04-01T23:59:59.000Z
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.
Harmonic Image Reconstruction Assisted by a Nonlinear Metmaterial Surface
Wang, Zhiyu
We experimentally demonstrate a microwave far-field image reconstruction modality with the transverse resolution exceeding the diffraction limit by using a single layer of highly nonlinear metamaterial. The harmonic fields ...
Nonlinear harmonic generation and devices in doubly resonant Kerr cavities
Hashemi, Hila
We describe a theoretical analysis of the nonlinear dynamics of third-harmonic generation (??3?) via Kerr (?(3)) nonlinearities in a resonant cavity with resonances at both ? and 3?. Such a doubly resonant cavity greatly ...
Investigation of plasma diagnostics using a dual frequency harmonic technique
Kim, Dong-Hwan [Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul (Korea, Republic of); Kim, Young-Do; Cho, Sung-Won; Kim, Yu-Sin; Chung, Chin-Wook, E-mail: joykang@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, Seoul (Korea, Republic of)
2014-09-07T23:59:59.000Z
Plasma diagnostic methods using harmonic currents analysis of electrostatic probes were experimentally investigated to understand the differences in their measurement of the plasma parameters. When dual frequency voltage (?{sub 1},?{sub 2}) was applied to a probe, various harmonic currents (?{sub 1},?2?{sub 1},?{sub 2},?2?{sub 2},?{sub 2}±?{sub 1},?{sub 2}±2?{sub 1}) were generated due to the non-linearity of the probe sheath. The electron temperature can be obtained from the ratio of the two harmonics of the probe currents. According to the combinations of the two harmonics, the sensitivities in the measurement of the electron temperature differed, and this results in a difference of the electron temperature. From experiments and simulation, it is shown that this difference is caused by the systematic and random noise.
Driven harmonic oscillator as a quantum simulator for open systems
Jyrki Piilo; Sabrina Maniscalco
2006-10-03T23:59:59.000Z
We show theoretically how a driven harmonic oscillator can be used as a quantum simulator for non-Markovian damped harmonic oscillator. In the general framework, the results demonstrate the possibility to use a closed system as a simulator for open quantum systems. The quantum simulator is based on sets of controlled drives of the closed harmonic oscillator with appropriately tailored electric field pulses. The non-Markovian dynamics of the damped harmonic oscillator is obtained by using the information about the spectral density of the open system when averaging over the drives of the closed oscillator. We consider single trapped ions as a specific physical implementation of the simulator, and we show how the simulator approach reveals new physical insight into the open system dynamics, e.g. the characteristic quantum mechanical non-Markovian oscillatory behavior of the energy of the damped oscillator, usually obtained by the non-Lindblad-type master equation, can have a simple semiclassical interpretation.
Casimir Friction Force for Moving Harmonic Oscillators
Johan S. Høye; Iver Brevik
2011-11-21T23:59:59.000Z
Casimir friction is analyzed for a pair of dielectric particles in relative motion. We first adopt a microscopic model for harmonically oscillating particles at finite temperature T moving non-relativistically with constant velocity. We use a statistical-mechanical description where time-dependent correlations are involved. This description is physical and direct, and, in spite of its simplicity, is able to elucidate the essentials of the problem. This treatment elaborates upon, and extends, an earlier theory of ours back in 1992. The energy change Delta E turns out to be finite in general, corresponding to a finite friction force. In the limit of zero temperature the formalism yields, however, Delta E ->0, this being due to our assumption about constant velocity, meaning slowly varying coupling. For couplings varying more rapidly, there will also be a finite friction force at T=0. As second part of our work, we consider the friction problem using time-dependent perturbation theory. The dissipation, basically a second order effect, is obtainable with the use of first order theory, the reason being the absence of cross terms due to uncorrelated phases of eigenstates. The third part of the present paper is to demonstrate explicitly the equivalence of our results with those recently obtained by Barton (2010); this being not a trivial task since the formal results are seemingly quite different from each other.
Wind LCA Harmonization (Fact Sheet), NREL (National Renewable Energy Laboratory)
Not Available
2013-06-01T23:59:59.000Z
NREL recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that provides more exact estimates of GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty. This involved a systematic review and harmonization of life cycle assessment (LCA) literature of utility-scale wind power systems in order to determine the causes of life cycle greenhouse gases (GHG) emissions and, where possible, reduce variability in GHG estimates.
Harmonic entanglement with second-order non-linearity
Nicolai B. Grosse; Warwick P. Bowen; Kirk McKenzie; Ping Koy Lam
2005-07-08T23:59:59.000Z
We investigate the second-order non-linear interaction as a means to generate entanglement between fields of differing wavelengths. And show that perfect entanglement can, in principle, be produced between the fundamental and second harmonic fields in these processes. Neither pure second harmonic generation, nor parametric oscillation optimally produce entanglement, such optimal entanglement is rather produced by an intermediate process. An experimental demonstration of these predictions should be imminently feasible.
Calculation of Massless Feynman Integrals using Harmonic Sums
Stefan Bekavac
2006-07-10T23:59:59.000Z
A method for the evaluation of the epsilon expansion of multi-loop massless Feynman integrals is introduced. This method is based on the Gegenbauer polynomial technique and the expansion of the Gamma function in terms of harmonic sums. Algorithms for the evaluation of nested and harmonic sums are used to reduce the expressions to get analytical or numerical results for the expansion coefficients. Methods to increase the precision of numerical results are discussed.
Fast optimal frictionless atom cooling in harmonic traps
Xi Chen; A. Ruschhaupt; S. Schmidt; A. del Campo; D. Guery-Odelin; J. G. Muga
2009-10-05T23:59:59.000Z
A method is proposed to cool down atoms in a harmonic trap without phase-space compression as in a perfectly slow adiabatic expansion, i.e., keeping the populations of the instantaneous initial and final levels invariant, but in a much shorter time. This may require that the harmonic trap becomes an expulsive parabolic potential in some time interval. The cooling times achieved are also shorter than previous minimal times using optimal-control bang-bang methods and real frequencies.
Harmonic generation of gravitational wave induced Alfven waves
Mats Forsberg; Gert Brodin
2007-11-26T23:59:59.000Z
Here we consider the nonlinear evolution of Alfven waves that have been excited by gravitational waves from merging binary pulsars. We derive a wave equation for strongly nonlinear and dispersive Alfven waves. Due to the weak dispersion of the Alfven waves, significant wave steepening can occur, which in turn implies strong harmonic generation. We find that the harmonic generation is saturated due to dispersive effects, and use this to estimate the resulting spectrum. Finally we discuss the possibility of observing the above process.
Relativistic distorted-wave analysis of quasielastic proton-nucleus scattering
Titus, N. P.; Ventel, B. I. S. van der; Niekerk, D. D. van; Hillhouse, G. C. [Department of Physics, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa); University for Information Science and Technology, Partizanska Street, Ohrid 6000 (Macedonia, The Former Yugoslav Republic of)
2011-04-15T23:59:59.000Z
A relativistic distorted-wave impulse approximation formalism is presented for the calculation of quasielastic proton-nucleus scattering. It is shown that the double differential cross section may be written as a contraction between the hadronic tensor (describing the projectile and ejectile) and the polarization tensor (describing the nuclear target) and that this mathematical structure also holds for the case where distortions are included. The eikonal approximation is used to introduce distortions in the wave functions, and the nuclear response is described using a Fermi gas model. The highly oscillatory nine-dimensional integrand contained in the expression for the double differential cross section is computed using a novel technique based on combining traditional Gaussian integration methods with the powerful fitting functions in the matlab programming language. This work has successfully calculated the distorted-wave quasielastic differential cross section for proton-nucleus scattering within a fully relativistic framework. It is found that the distortions lead to a reduction in the double differential cross section and have a negligible effect on the computed spin observables.
Evaluation of inherent distortions in the IIST facility using the RELAP5/MOD3 code
Ferng, Y.M. [Inst. of Nuclear Energy Research, Lung-Tan (Taiwan, Province of China)
1996-06-01T23:59:59.000Z
The Institute of Nuclear Energy Research (INER) integral system test (IIST) facility is a reduced-height, reduced-pressure test facility constructed at INER that is used to simulate the thermal hydraulics of the Maanshan nuclear power plant (NPP). A small-scaled facility is not capable of simulating all the physical phenomena of an NPP because the behavior of an NPP during accidents is very complicated. Proper scaling then plays an important role in the design of a test facility to ensure the usefulness and applicability of experimental data obtained from a small-scaled facility. However, distortions caused by necessary compromises in the design and construction of a small-scaled test facility exist. The analysis here evaluates whether the inherent distortions in the IIST facility will distort the thermal-hydraulic behaviors of a natural-circulation experiment and influence the usefulness and applicability of the experimental data. Based on the current calculations, the IIST experimental results are found to be partially distorted. Appropriate consideration of and correction for these distortion effects are needed before the results of the IIST natural-circulation experiments can be used to reliably investigate the Maanshan NPP behavior expected by way of an appropriate scale-up procedure.
Linear harmonic analysis of Stirling engine thermodynamics
Chen, N.C.J.; Griffin, F.P.; West, C.D.
1984-08-01T23:59:59.000Z
The analysis involves linearization of the pressure waveform and represents each term in the conservation equations by a truncated Fourier series, including enthalpy flux discontinuity. Second-Law analysis is presented of four important loss mechanisms that result from adiabatic cylinders, transient heat transfer in semiadiabatic cylinders, pressure drop through the heat exchangers, and gas leakage from the compression space. The four loss mechanisms, all leading to efficiency reduction below the Carnot level, are characterized by irreversible thermodynamic processes that occur when heat is transferred across a finite temperature difference; when gases at two different temperatures are mixed; or when there is a mass flow through a pressure difference. The allocation of each individual loss mechanism is derived precisely in terms of entropy production but evaluated by use of pressure, temperature, and mass oscillations calculated from the linear harmonic approximation. When the theory is applied to an engine of Sunpower's RE-1000 dimensions, it reveals clearly that the adiabatic loss (due to temperature fluctuations in the cylinders) consists of two components: gas mixing and heat transfer across a temperature difference. The theory further shows that the adiabatic effect is more important than the transient heat transfer loss if the gas-to-cylinder heat transfer rate is small (i.e., nearly adiabatic conditions); the reverse is true for intermediate heat transfer rates; and both losses vanish at very high heat transfer rates. In addition, entropy analyses of pressure drop and mass leakage for isothermal cylinders shed some light on coupling between the different individual loss mechanisms.
Kung, Andy
Numerical Analysis of Fifth-Harmonic Conversion of Low-Power Pulsed Nd:YAG Laser with Resonance of Second Harmonic Lien-Bee CHANG1Ã? , S. C. WANG1 and A. H. KUNG1;2 1 Institute of Electro March 13, 2003) A model for the fifth-harmonic generation of pulsed IR lasers involving an external ring
The structural distortion of the anti-perovskite nitride Ca sub 3 AsN
Chern, M.Y.; DiSalvo, F.J. (Cornell Univ., Ithaca, NY (United States)); Parise, J.B. (State Univ. of New York, Stony Brook, NY (United States)); Goldstone, J.A. (Los Alamos National lab., NM (United States))
1992-02-01T23:59:59.000Z
The structure of the distorted anti-perovskite nitride Ca{sub 3}AsN has been studied both by neutron powder diffraction at 305 and 15 K and by X-ray powder diffraction at room temperature. Ca{sub 3}AsN is distorted to an orthorhombic cell with a and b {approximately} {radical}2a{prime} and c{approximately}2a{prime}, where a{prime} is the lattice constant of the ideal undistorted cubic anti-perovskite. The distortion is produced by tilting of octahedra of Ca{sub 6}N and results in six short and six long bond distances of the twelvefold coordinated As atom by Ca atoms.
Analysis of periodically-forced turbulence in the rapid distortion limit
O'Neil, Joshua Robert
2006-04-12T23:59:59.000Z
ANALYSIS OF PERIODICALLY-FORCED HOMOGENEOUS TURBULENCE IN THE RAPID DISTORTION LIMIT A Thesis by JOSHUA R. O?NEIL Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 2004 Major Subject: Aerospace Engineering ANALYSIS OF PERIODICALLY-FORCED HOMOGENEOUS TURBULENCE IN THE RAPID DISTORTION LIMIT A Thesis by JOSHUA R. O?NEIL Submitted to Texas A&M University in partial fulfillment of the requirements...
Dynamics of harmonically-confined systems: Some rigorous results
Wu, Zhigang, E-mail: zwu@physics.queensu.ca; Zaremba, Eugene, E-mail: zaremba@sparky.phy.queensu.ca
2014-03-15T23:59:59.000Z
In this paper we consider the dynamics of harmonically-confined atomic gases. We present various general results which are independent of particle statistics, interatomic interactions and dimensionality. Of particular interest is the response of the system to external perturbations which can be either static or dynamic in nature. We prove an extended Harmonic Potential Theorem which is useful in determining the damping of the centre of mass motion when the system is prepared initially in a highly nonequilibrium state. We also study the response of the gas to a dynamic external potential whose position is made to oscillate sinusoidally in a given direction. We show in this case that either the energy absorption rate or the centre of mass dynamics can serve as a probe of the optical conductivity of the system. -- Highlights: •We derive various rigorous results on the dynamics of harmonically-confined atomic gases. •We derive an extension of the Harmonic Potential Theorem. •We demonstrate the link between the energy absorption rate in a harmonically-confined system and the optical conductivity.
Higher harmonics increase LISA's mass reach for supermassive black holes
K. G. Arun; Bala R. Iyer; B. S. Sathyaprakash; Siddhartha Sinha
2007-06-05T23:59:59.000Z
Current expectations on the signal to noise ratios and masses of supermassive black holes which the Laser Interferometer Space Antenna (LISA) can observe are based on using in matched filtering only the dominant harmonic of the inspiral waveform at twice the orbital frequency. Other harmonics will affect the signal-to-noise ratio of systems currently believed to be observable by LISA. More significantly, inclusion of other harmonics in our matched filters would mean that more massive systems that were previously thought to be {\\it not} visible in LISA should be detectable with reasonable SNRs. Our estimates show that we should be able to significantly increase the mass reach of LISA and observe the more commonly occurring supermassive black holes of masses $\\sim 10^8M_\\odot.$ More specifically, with the inclusion of all known harmonics LISA will be able to observe even supermassive black hole coalescences with total mass $\\sim 10^8 M_\\odot (10^9M_\\odot)$ (and mass-ratio 0.1) for a low frequency cut-off of $10^{-4}{\\rm Hz}$ $(10^{-5}{\\rm Hz})$ with an SNR up to $\\sim 60$ $(\\sim 30)$ at a distance of 3 Gpc. This is important from the astrophysical viewpoint since observational evidence for the existence of black holes in this mass range is quite strong and binaries containing such supermassive black holes will be inaccessible to LISA if one uses as detection templates only the dominant harmonic.
Harmonic entanglement in a degenerate parametric down conversion
Sintayehu Tesfa
2007-07-25T23:59:59.000Z
We study the harmonic entanglement and squeezing in a two-mode radiation produced in a degenerate parametric down conversion process coupled to a two-mode vacuum reservoir employing the linearization procedure. It is found that there is a quadrature entanglement between the harmonically related fundamental and second-harmonic modes and the superimposed radiation exhibits a significant two-mode squeezing. The entanglement exits even when there is no two-mode squeezing, since the correlation leading to these phenomena are essentially different. In addition, the more the external coherent light is down converted, the more stronger the entanglement and mean photon number of the two-mode radiation would be which is not generally true for squeezing.
Unitary approach to the quantum forced harmonic oscillator
D. Velasco-Martinez; V. G. Ibarra-Sierra; J. C. Sandoval-Santana; J. L. Cardoso; A. Kunold
2014-08-31T23:59:59.000Z
In this paper we introduce an alternative approach to studying the evolution of a quantum harmonic oscillator subject to an arbitrary time dependent force. With the purpose of finding the evolution operator, certain unitary transformations are applied successively to Schr\\"odinger's equation reducing it to its simplest form. Therefore, instead of solving the original Schr\\"odinger's partial differential equation in time and space the problem is replaced by a system of ordinary differential equations. From the obtained evolution operator we workout the propagator. Even though we illustrate the use of unitary transformations on the solution of a forced harmonic oscillator, the method presented here might be used to solve more complex systems. The present work addresses many aspects regarding unitary transformations and the dynamics of a forced quantum harmonic oscillator that should be useful for students and tutors of the quantum mechanics courses at the senior undergraduate and graduate level.
Economic Reforms and Gender-based Wage Inequality in the Presence of Factor Market Distortions
Bandyopadhyay, Antar
1 Economic Reforms and Gender-based Wage Inequality in the Presence of Factor Market Distortions-based wage inequality. The analysis finds that credit market reform and tariff reform produce favourable reforms, general equilibrium. JEL classifications: D50, J16, F21. The authors are thankful to Prof
A Distortion-Theoretic Perspective for Redundant Metering Security in a Smart Grid
Kundur, Deepa
A Distortion-Theoretic Perspective for Redundant Metering Security in a Smart Grid Mustafa El--In a smart grid environment some customers employ third-party meters and terminals for integrity verification of the smart meter power measurements reported by the electric utility company. We address the security issues
Fractal-driven distortion of resting state functional networks in fMRI: a simulation study
Fractal-driven distortion of resting state functional networks in fMRI: a simulation study Wonsang, Magdeburg, Germany E-mail: you@lin-magdeburg.de Fractals are self-similar and scale-invariant patterns found ubiquitously in nature. A lot of evidences implying fractal properties such as 1/f power spectrums have been
Sensitivity of Gaussian Channel Capacity and ate-Distortion Function to nonGaussian Contamination
Verdú, Sergio
Sensitivity of Gaussian Channel Capacity and ate-Distortion Function to nonGaussian Contamination-Gaussian contaminating noise. Although the ca- pacity of such channels cannot be evaluated in general, we analyze the decrease in capacity, or sensitivity of the channel capacity to the weak contaminating noise. We show
Memory Distortion in People Reporting Abduction by Aliens Susan A. Clancy, Richard J. McNally,
Schacter, Daniel
Memory Distortion in People Reporting Abduction by Aliens Susan A. Clancy, Richard J. Mc memories of traumatic events that are unlikely to have occurred: abduction by space aliens. A variant abduction, people who believe they were abducted by aliens but have no memories, and people who deny having
P16: A distortion-weighted glimpse-based intelligibility metric for modified and synthetic speech
Edinburgh, University of
for speech enhancement in known noise conditions," in Proc. Interspeech, pp. 1636-1639. M. Cooke, C. Mayo, CP16: A distortion-weighted glimpse-based intelligibility metric for modified and synthetic speech Yan Tang1 and Martin Cooke2,1 Cassia Valentini-Botinhao3 1 Language and Speech Laboratory, University
Visually-based temporal distortion in dyslexia Alan Johnston a,b,*, Aurelio Bruno a
Johnston, Alan
Visually-based temporal distortion in dyslexia Alan Johnston a,b,*, Aurelio Bruno a , Junji history: Received 11 March 2008 Received in revised form 18 April 2008 Keywords: Time Dyslexia evidence for anomalous cortico-thalamic circuits in dyslexia. Crown Copyright Ã? 2008 Published by Elsevier
FINITE ELEMENT ANALYSIS OF THERMAL TENSIONING TECHNIQUES MITIGATING WELD BUCKLING DISTORTION
Michaleris, Panagiotis
FINITE ELEMENT ANALYSIS OF THERMAL TENSIONING TECHNIQUES MITIGATING WELD BUCKLING DISTORTION. This paper presents a finite element analysis model of the thermal tensioning technique. A series of finite by the finite element simulations, the residual stresses of large size and high heat input welds are reduced
He, Zhihai "Henry"
-Rate-Distortion Optimization Zhihai He, Wenye Cheng, and Xi Chen £ Department of Electrical and Computer Engineering University framework to save the data processing energy and extend the operational lifetime of portable video communication devices. Video compression is computationally intensive and energy-consuming. However, portable
Distorted benzene bearing two bulky substituents on adjacent positions: structure of
Kaszynski, Piotr
Distorted benzene bearing two bulky substituents on adjacent positions: structure of 1,2-bis(1,2-dicarba-closo-dodecaboran-1-yl)benzene Yasuyuki Endo,a,* Chalermkiat Songkram,b Kiminori Ohta,a Piotr analysis of 1,2-bis(o-carboranyl)benzene were performed to examine the steric effects of the two extremely
A Rate-Energy-Distortion Analysis for Compressed-Sensing-Enabled Wireless Video Streaming on
Melodia, Tommaso
A Rate-Energy-Distortion Analysis for Compressed-Sensing-Enabled Wireless Video Streaming. The objective of this paper is to conduct an experiment- driven analysis of the energy links for low-complexity multimedia sensing devices with a limited budget of available energy per video
Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings
Christoph Beckermann; Kent Carlson
2011-07-22T23:59:59.000Z
Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a castingÃ?Â?Ã?Â¢Ã?Â?Ã?Â?Ã?Â?Ã?Â?s overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions of the Navy-C ring (a classical test shape for heat treatment experiments) for several carbon and low alloy steels in order to generate data necessary to validate the code. The predicted distortions were in reasonable agreement with the experimentally measured values. However, the final distortions in the castings were small, making it difficult to determine how accurate the predictions truly are. It is recommended that further validation of the software be performed with the aid of additional experiments with large production steel castings that experience significant heat treatment distortions. It is apparent from this research that the mechanical properties of the bonded sand used for cores and sand molds are key in producing accurate stress simulation results. Because of this, experiments were performed to determine the temperature-dependent elastic modulus of a resin-bonded sand commonly utilized in the steel casting industry. The elastic modulus was seen to vary significantly with heating and cooling rates. Also, the retained room temperature elastic modulus after heating was seen to degrade significantly when the sand was heated above 125Ã?Â?Ã?Â?Ã?Â?Ã?Â°C. The elastic modulus curves developed in this work can readily be utilized in casting simulation software. Additional experiments with higher heating rates are recommended to determine the behavior of the elastic modulus in the sand close to the mold-metal interface. The commercial heat treatment residual stress and distortion code, once fully validated, is expected to result in an estimated energy savings of 2.15 trillion BTUÃ?Â?Ã?Â¢Ã?Â?Ã?Â?Ã?Â?Ã?Â?s/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology.
Chang, Belinda
Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion modes and their relation to energy storage in the primary photoproduct. Low-temperature (77 K) resonance interactions of the 9- and 13-methyl groups with surrounding residues. This distortion stores light energy
Paris-Sud XI, Université de
4 Direct power control of shunt active filter using high selectivity filter (HSF) under distorted.A. Djaffar) Abstract This paper describes the design of a new configuration of direct power control (DPC, Direct power control (DPC), Switching table, High selectivity filter, Distorted or unbalanced conditions
Pickart, Robert S.
of the Greenland Flow Distortion Experiment G.W.K. Moore Department of Physics University of Toronto R.S. Pickart January 21, 2009 #12; 2 Abstract: Due to its high topography, Greenland results in significant to help document this flow distortion as part of the international research project called the Greenland
Krylov, Anna I.
Charge localization and JahnTeller distortions in the benzene dimer cation Piotr A. Pieniazek August 2008 JahnTeller JT distortions and charge localization in the benzene dimer cation are analyzed.1063/1.2969107 I. INTRODUCTION The benzene dimer cation is an important model system for radiation
Harmonic measurements made on the upgraded New Zealand inter-island HVdc transmission system
Miller, A.J.V.; Dewe, M.B. (Univ. of Canterbury, Christchurch (New Zealand))
1994-07-01T23:59:59.000Z
This paper introduces the recent upgrade to the New Zealand inter-island HVdc transmission system. It then details the procedure of one of several tests conducted to measure harmonic levels created by the upgraded transmission system. Harmonic levels were measured using the CHART (Continuous Harmonic Analysis in Real-Time) harmonic monitoring instrumentation. The connection of CHART to the high voltage network and its configuration during the test is discussed. A sample of results gathered while monitoring are presented, including characteristic harmonics of the converter, and maximum voltage and current levels up to the 50th harmonic for each of the three a.c. phases. During the tests one of the two a.c. harmonic filters was switched out to observe its effect on harmonic levels. It was found that with both a.c. harmonic filters operating, most harmonic levels were lower than with only one filter operating. However some harmonic levels, namely the 4th harmonic, were larger with both filters operating. The paper is concluded with a discussion of the results and of the difficulties encountered in measuring harmonics of very low level.
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)
2014-04-15T23:59:59.000Z
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.
Cascaded Cerenkov third-harmonic generation in random quadratic media
Ayoub, Mousa; Roedig, Philip; Imbrock, Joerg; Denz, Cornelia [Institute of Applied Physics and Center for Nonlinear Science (CeNoS), Westfaelische Wilhelms-Universitaet Muenster, Corrensstrasse 2, 48149 Muenster (Germany)
2011-12-12T23:59:59.000Z
We investigate experimentally and theoretically the conical emission of Cerenkov-type third-harmonic generation in strontium barium niobate of random 2D-{chi}{sup (2)} distribution. The azimuthal intensity distribution is explained by the polarization properties of the fundamental and Cerenkov second-harmonic waves, depending on the cascaded origin of the generation process. Moreover, we show the role of the individual domain shape in an additional modulation on the conical emission, controlled by the electrical switching of the spontaneous polarization of the ferroelectric medium.
Harmonic mean, the Gamma factor and Speed of Light
Chandru Iyer
2008-11-17T23:59:59.000Z
The relationship between the harmonic mean and special relativity is concisely elucidated. The arguments in favor and against SRT are explored. It is shown that the ratio of the speed of light to the harmonic mean of the onward and return speeds of light in a moving frame under Newtonian mechanics, when equitably distributed between space and time as a correction, leads to the Lorentz transformation. This correction implies an apparent contraction of objects and time dilation. However, the symmetry of the onward and inverse transformations give a different meaning to the gamma factor
On the harmonic oscillator properties in a twisted Moyal plane
Ezinvi Baloitcha; Mahouton Norbert Hounkonnou; Dine Ousmane Samary
2012-03-25T23:59:59.000Z
This work prolongs, using an operator method, the investigations started in our recent paper J. Math. Phys. 51., 102108 on the spectrum and states of the harmonic oscillator on twisted Moyal plane, where rather a Moyal-star-algebraic approach was used. The physical spectrum and states of the harmonic oscillator on twisted Moyal space, obtained here by solving the corresponding differential equation, are similar to those of the ordinary Moyal space, with different parameters. This fortunately contrasts with the previous study which produced unexpected results, i.e. infinitely degenerate states with energies depending on the coordinate functions.
Harmonic analysis on a galois field and its subfields
A. Vourdas
2006-10-17T23:59:59.000Z
Complex functions $\\chi (m)$ where $m$ belongs to a Galois field $GF(p^ \\ell)$, are considered. Fourier transforms, displacements in the $GF(p^ \\ell) \\times GF(p^ \\ell)$ phase space and symplectic $Sp(2,GF(p^ \\ell))$ transforms of these functions are studied. It is shown that the formalism inherits many features from the theory of Galois fields. For example, Frobenius transformations are defined which leave fixed all functions $h(n)$ where $n$ belongs to a subfield $GF(p^ d)$ of the $GF(p^ \\ell)$. The relationship between harmonic analysis (or quantum mechanics) on $GF(p^ \\ell)$ and harmonic analysis on its subfields, is studied.
Constraint damping in the Z4 formulation and harmonic gauge
Carsten Gundlach; Jose M. Martin-Garcia; Gioel Calabrese; Ian Hinder
2005-07-14T23:59:59.000Z
We show that by adding suitable lower-order terms to the Z4 formulation of the Einstein equations, all constraint violations except constant modes are damped. This makes the Z4 formulation a particularly simple example of a lambda-system as suggested by Brodbeck et al. We also show that the Einstein equations in harmonic coordinates can be obtained from the Z4 formulation by a change of variables that leaves the implied constraint evolution system unchanged. Therefore the same method can be used to damp all constraints in the Einstein equations in harmonic gauge.
Paris-Sud XI, Université de
BLIND HARMONIC ADAPTIVE DECOMPOSITION APPLIED TO SUPERVISED SOURCE SEPARATION Benoit Fuentes through an algorithm called Blind Harmonic Adaptive Decomposition (BHAD). This algorithm provides [1]. However, performing this task in a completely blind way remains challenging, basically due
Ultrasensitive Optical Shape Characterization of Gold Nanoantennas Using Second Harmonic Generation
Dalang, Robert C.
Ultrasensitive Optical Shape Characterization of Gold Nanoantennas Using Second Harmonic Generation for the sensitive optical characterization of plasmonic nanostructures. Furthermore, defects located where on the second harmonic signal. KEYWORDS: Plasmonics, nonlinear optics, surface integral formulation, realistic
Wideband phased array antennas and compact, harmonic-suppressed microstrip filters
Tu, Wen-Hua
2009-05-15T23:59:59.000Z
. Since the electromagnetic spectrum is limited and has to be shared, interference is getting serious as more and more wireless applications emerge. Filters are key components to prevent harmonic interference. The harmonic signals can be suppressed...
Wideband phased array antennas and compact, harmonic-suppressed microstrip filters
Tu, Wen-Hua
2009-05-15T23:59:59.000Z
. Since the electromagnetic spectrum is limited and has to be shared, interference is getting serious as more and more wireless applications emerge. Filters are key components to prevent harmonic interference. The harmonic signals can be suppressed...
Harmonic analysis of climatological sea surface salinity Tim P. Boyer and Sydney Levitus
Harmonic analysis of climatological sea surface salinity Tim P. Boyer and Sydney Levitus Ocean: Boyer, T. P., and S. Levitus, Harmonic analysis of climatological sea surface salinity, J. Geophys. Res
Fault Detection and Diagnostics for Non-Intrusive Monitoring Using Motor Harmonics
Orji, Uzoma A.
Harmonic analysis of motor current has been used to track the speed of motors for sensorless control. Algorithms exist that track the speed of a motor given a dedicated stator current measurement, for example. Harmonic ...
Improved gauge driver for the generalized harmonic Einstein system Lee Lindblom and Bela Szilagyi
Lindblom, Lee
Improved gauge driver for the generalized harmonic Einstein system Lee Lindblom and BeÂ´la SzilaÂ´gyi
A three-phase converter model for harmonic analysis of HVDC systems
Xu, W.; Drakos, J.E.; Mansour, Y.; Chang, A. (B.C. Hydro, Burnaby, British Columbia (Canada))
1994-07-01T23:59:59.000Z
An equivalent circuit model is presented to model bridge converters for three-phase HVDC harmonic power flow analysis. The validity and accuracy of the model are verified by comparing simulation results against field test results. The model is interfaced with a multiphase harmonic load flow program to investigate the generation of non-characteristic harmonics from HVDC links and the flow of HVDC harmonics in a real system.
Wave kernels for the Dirac, Euler operators and the harmonic oscillator
Mohameden, Ahmedou Yahya Ould, E-mail: ahmeddou2011@yahoo.fr; Moustapha, Mohamed Vall Ould, E-mail: khames@univ-nkc.mr [Université des Sciences, de Technologie et de la Medécine (USTM) Faculté des Sciences et Techniques. Département de Mathématiques et Informatique, Unité de Recherche: Analyse, EDP et Modélisation: (AEDPM) B.P: 5026, Nouakchott-Mauritanie (United States)
2014-03-15T23:59:59.000Z
Explicit solutions for the wave equations associated to the Dirac, Euler operators and the harmonic oscillator are given.
Enhanced Harmonic Up-Conversion Using a Hybrid HGHG-EEHG Scheme
Marksteiner, Quinn R. [Los Alamos National Laboratory; Bishofberger, Kip A. [Los Alamos National Laboratory; Carlsten, Bruce E. [Los Alamos National Laboratory; Freund, Henry P. [Los Alamos National Laboratory; Yampolsky, Nikolai A. [Los Alamos National Laboratory
2012-04-30T23:59:59.000Z
We introduce a novel harmonic generation scheme which can be used, for a given desired harmonic, to achieve higher bunching factors, weaker chicanes, and/or less final energy spread than can be achieved using Echo-Enabled Harmonic Generation. This scheme only requires a single laser with relatively low power, and is a hybrid of High-Gain Harmonic Generation and EEHG. We present a design of this scheme applied to the Next Generation Light Source (NGLS).
Web-assisted tunneling in the kicked harmonic oscillator
André R. R. Carvalho; Andreas Buchleitner
2004-09-20T23:59:59.000Z
We show that heating of harmonically trapped ions by periodic delta kicks is dramatically enhanced at isolated values of the Lamb-Dicke parameter. At these values, quasienergy eigenstates localized on island structures undergo avoided crossings with extended web-states.
LOWPASS BROADBAND HARMONIC FILTER DESIGN A THESIS SUBMITTED TO
Hava, Ahmet
. Nevzat ÖZAY METU, (EE) _____________________ Dr. Ahmet Erbil NALÇACI (Energy Market Regulatory Authority regulation, energy efficiency, size, and cost. The parallel/series harmonic resonance problem related issues/currents. Thus, the size and the performance of the filter can be optimized. The analytical method is verified
HHFW (High Harmonic Fast Wave) Eddy Current Analysis for Antenna
Princeton Plasma Physics Laboratory
1 NSTX HHFW (High Harmonic Fast Wave) Eddy Current Analysis for Antenna NSTX-CALC-24-03-01 June 1 performed.) The model was first built for NSTX to verify the eddy current effect on antenna during plasma force of the induced eddy current in the components. The force data was transferred to the structural
Classical thermodynamics of particles in harmonic traps Martin Ligarea
Ligare, Martin
, and the heat capacities. I also consider cyclic thermodynamic processes in a harmonically confined gas. Â© 2010 of state for a gas of N noninteract- ing particles in a rigid volume V is derived in almost every text and pressure vary with position within such traps, and the volume of the gas is not well defined
Valency of Harmonic Mappings onto Bounded Convex Domains
1910-30-82T23:59:59.000Z
[11] considered harmonic mappings of D to K that extend continuously to n- valent sense-preserving ..... ?3(u) = 8(1 + 35u)3?2(u) + 27(13u ? 1)(1 + 3u)3. Note that ?3(0) = ?3 = 0; ..... conjecture of H. S. Shapiro, Math. Proc. Cambridge Phil.
SPEECH ENHANCEMENT USING HARMONIC REGENERATION Cyril Plapous 1
Paris-Sud XI, UniversitÃ© de
SPEECH ENHANCEMENT USING HARMONIC REGENERATION Cyril Plapous 1 , Claude Marro 1 , Pascal Scalart 2 in enhanced speech because of the non reliability of estimators for small signal- to-noise ratios. We propose The problem of enhancing speech degraded by additive noise, when only the noisy speech is available, has been
Harmonic superspace formalism and the consistent chiral anomaly
Li, W.
1986-08-01T23:59:59.000Z
The harmonic superspace formalism has been used to construct the consistent chiral anomaly in N = 1, d = 6 supersymmetric Yang-Mills thoery. The expressions of the gauge anomaly ..delta../sub s//sup phi/ and of the supersymmetric anomaly ..delta../sub SUSY//sup phi/ are given together with the consistent condition. 7 refs.
Generation of harmonics and supercontinuum in nematic liquid crystals
Nyushkov, B N; Trashkeev, S I; Klementyev, Vasilii M; Pivtsov, V S; Kobtsev, Sergey M
2013-02-28T23:59:59.000Z
Nonlinear optical properties of nematic liquid crystals (NLC) have been investigated. A technique for efficient laser frequency conversion in a microscopic NLC volume deposited on an optical fibre end face is experimentally demonstrated. An efficient design of a compact NLC-based IR frequency converter with a fibre input and achromatic collimator is proposed and implemented. Simultaneous generation of the second and third harmonics is obtained for the first time under pumping NLC by a 1.56-mm femtosecond fibre laser. The second-harmonic generation efficiency is measured to be about 1 %, while the efficiency of third-harmonic generation is several tenths of percent. A strong polarisation dependence of the third-harmonic generation efficiency is revealed. When pumping NLC by a cw laser, generation of spectral supercontinua (covering the visible and near-IR spectral ranges) is observed. The nonlinear effects revealed can be due to the light-induced change in the orientational order in liquid crystals, which breaks the initial symmetry and leads to formation of disclination structures. The NLC optical nonlinearity is believed to be of mixed orientationalelectronic nature as a whole. (laser optics 2012)
-okfl ^ ORNL/CON-172 Linear Harmonic Analysis of Free-
Oak Ridge National Laboratory
Stirling Engines N. C. J. Chen F. P. Griffin OPERATED BY MARTIN MARIETTA ENERGY SYSTEMS, INC. #12;ORNL/CON-172 Engineering Technology Division* LINEAR HARMONIC ANALYSIS OF FREE-PISTON STIRLING/dynamic problem that is associated with a free-piston Stirling engine (FPSE). The governing equations
Noncommutative Harmonic Oscillator at Finite Temperature: A Path Integral Approach
A. Jahan
2012-08-01T23:59:59.000Z
We use the path integral approach to a two-dimensional noncommutative harmonic oscillator to derive the partition function of the system at finite temperature. It is shown that the result based on the Lagrangian formulation of the problem, coincides with the Hamiltonian derivation of the partition function.
On the harmonic oscillator realisation of q-oscillators
D. Gangopadhyay; A. P. Isaev
2007-01-05T23:59:59.000Z
The general version of the bosonic harmonic oscillator realisation of bosonic q-oscillators is given. It is shown that the currently known realisation is a special case of our general solution. The investigation has been performed at the Laboratory of theoretical Physics,JINR.
Generalized harmonic spatial coordinates and hyperbolic shift conditions
Miguel Alcubierre; Alejandro Corichi; José A. González; Darío Núñez; Bernd Reimann; Marcelo Salgado
2005-10-24T23:59:59.000Z
We propose a generalization of the condition for harmonic spatial coordinates analogous to the generalization of the harmonic time slices introduced by Bona et al., and closely related to dynamic shift conditions recently proposed by Lindblom and Scheel, and Bona and Palenzuela. These generalized harmonic spatial coordinates imply a condition for the shift vector that has the form of an evolution equation for the shift components. We find that in order to decouple the slicing condition from the evolution equation for the shift it is necessary to use a rescaled shift vector. The initial form of the generalized harmonic shift condition is not spatially covariant, but we propose a simple way to make it fully covariant so that it can be used in coordinate systems other than Cartesian. We also analyze the effect of the shift condition proposed here on the hyperbolicity of the evolution equations of general relativity in 1+1 dimensions and 3+1 spherical symmetry, and study the possible development of blow-ups. Finally, we perform a series of numerical experiments to illustrate the behavior of this shift condition.
Strong Second Harmonic Generation from the Tantalum Thioarsenates...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Strong Second Harmonic Generation from the Tantalum Thioarsenates A3Ta2AsS11 (A K and Rb) Home Author: T.K. Bera, J.I. Jang, J.B. Ketterson, M.G. Kanatzidis Year: 2009 Abstract:...
Linear harmonic oscillator in spaces with degenerate metrics
N. A. Gromov
2006-03-02T23:59:59.000Z
With the help of contraction method we study the harmonic oscillator in spaces with degenerate metrics, namely, on Galilei plane and in the flat 3D Cayley-Klein spaces $R_3(j_2,j_3).$ It is shown that the inner degrees of freedom are appeared which physical dimensions are different from the dimension of the space.
Harmonic Superfields in N=4 Supersymmetric Quantum Mechanics
Evgeny A. Ivanov
2011-02-11T23:59:59.000Z
This is a brief survey of applications of the harmonic superspace methods to the models of N=4 supersymmetric quantum mechanics (SQM). The main focus is on a recent progress in constructing SQM models with couplings to the background non-Abelian gauge fields. Besides reviewing and systemizing the relevant results, we present some new examples and make clarifying comments.
Harmonic analysis of the Ha velocity field of NGC 4254
Laurent Chemin; Olivier Hernandez; Chantal Balkowski; Claude Carignan; Philippe Amram
2005-12-20T23:59:59.000Z
The ionized gas kinematics of the Virgo Cluster galaxy NGC 4254 (Messier 99) is analyzed by an harmonic decomposition of the velocity field into Fourier coefficients. The aims of this study are to measure the kinematical asymmetries of Virgo cluster galaxies and to connect them to the environment. The analysis reveals significant $m=1,2,4$ terms which origins are discussed.
Analytic and algorithmic aspects of generalized harmonic sums and polylogarithms
Ablinger, Jakob; Schneider, Carsten [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040, Linz (Austria)] [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040, Linz (Austria); Blümlein, Johannes [Deutsches Elektronen–Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)] [Deutsches Elektronen–Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
2013-08-15T23:59:59.000Z
In recent three-loop calculations of massive Feynman integrals within Quantum Chromodynamics (QCD) and, e.g., in recent combinatorial problems the so-called generalized harmonic sums (in short S-sums) arise. They are characterized by rational (or real) numerator weights also different from ±1. In this article we explore the algorithmic and analytic properties of these sums systematically. We work out the Mellin and inverse Mellin transform which connects the sums under consideration with the associated Poincaré iterated integrals, also called generalized harmonic polylogarithms. In this regard, we obtain explicit analytic continuations by means of asymptotic expansions of the S-sums which started to occur frequently in current QCD calculations. In addition, we derive algebraic and structural relations, like differentiation with respect to the external summation index and different multi-argument relations, for the compactification of S-sum expressions. Finally, we calculate algebraic relations for infinite S-sums, or equivalently for generalized harmonic polylogarithms evaluated at special values. The corresponding algorithms and relations are encoded in the computer algebra package HarmonicSums.
Real-Time Selective Harmonic Minimization in Cascaded Multilevel Inverters
Tolbert, Leon M.
time but the output fundamental voltage will stay constant and the harmonic will still meet capability of generalizing solutions. What this means is that, if the correct range of data are used sources along with its operation as in a solar panel. This means that during a day of operation, the solar
HARMONIC MOMENTS AND AN INVERSE PROBLEMS FOR THE HEAT EQUATION
.3) with p HPm , where HPm = { harmonic polynomial of degree m } (m = 0, 1, 2, · · · ), 1 #12;2 BY MISHIO KAWASHITA, YAROSLAV KURYLEV AND HIDEO SOGA and all q HPm . In the paper we describe algorithms for an approximate reconstruction of given approximate integrals (1.4) with p, q HPm , m = 0, 1, 2
ANALYTIC MODEL OF HARMONIC GENERATION IN THE LOW-GAIN FEL REGIME
Wurtele, Jonathan
ANALYTIC MODEL OF HARMONIC GENERATION IN THE LOW-GAIN FEL REGIME G. Penn, M. Reinsch, J.S. Wurtele , LBNL, Berkeley, CA 94720, USA Abstract Harmonic generation using free electron lasers (FELs) requires with simulation results using the FEL code GENESIS, both for single stages of harmonic generation and for the LUX
Source levels and harmonic content of whistles in white-beaked dolphins (Lagenorhynchus albirostris)
Source levels and harmonic content of whistles in white-beaked dolphins (Lagenorhynchus albirostris of the 43 whistles contained an unequal number of harmonics recorded at the three hydrophones judging from of the fundamen- tal frequency is a harmonic Yost, 2000 . Rasmussen
Koch, Christiane
and harmonic baths David Gelmana) Fritz Haber Research Center for Molecular Dynamics, Hebrew University to a spin bath and to a harmonic bath. Converged results are obtained for the spin bath by the surrogate. The results are compared to calculations that include a finite number of harmonic modes carried out by using
HARMONIC CASCADE FEL DESIGNS FOR LUX G. Penn, M. Reinsch, J. Wurtele
Wurtele, Jonathan
HARMONIC CASCADE FEL DESIGNS FOR LUX G. Penn, M. Reinsch, J. Wurtele , J.N. Corlett, W.M. Fawley, A stages of higher harmonic generation, seeded by a 200Â250 nm laser of similar duration. This laser mod then produces ra- diation at a higher harmonic after entering a second, differ- ently tuned undulator. Repeated
IEEE TRANSACTIONSON PLASMA SCIENCE,VOL. 21, NO. 1, FEBRUARY 1993 Phase-Matched Third Harmonic
IEEE TRANSACTIONSON PLASMA SCIENCE,VOL. 21, NO. 1, FEBRUARY 1993 ~ 105 Phase-Matched Third Harmonic Generation in a Plasma J. M. Rax and N. J. Fisch Abstract-Relativistic third harmonic generationin a plasma is investigated. The growth of a third harmonic wave is limited by the difference between the phase velocity
Optical Third-Harmonic Generation in Graphene Sung-Young Hong,1
Hone, James
Optical Third-Harmonic Generation in Graphene Sung-Young Hong,1 Jerry I. Dadap,2,* Nicholas Petrone York 10027, USA (Received 8 April 2013; published 10 June 2013) We report strong third-harmonic verified. In addition, our polarization- and azimuthal-rotation-dependent third-harmonic
Research Report Effects of attention on the neural processing of harmonic syntax
Research Report Effects of attention on the neural processing of harmonic syntax in Western music) were recorded. The five-chord progressions included 61% harmonically expected cadences (IÂI6 ÂIVÂVÂI), 26% harmonically unexpected cadences (IÂI6 ÂIVÂVÂN6 ), and 13% with one of the five chords having
3D Harmonic Mapping and Tetrahedral Meshing of Brain Imaging Data
Thompson, Paul
3D Harmonic Mapping and Tetrahedral Meshing of Brain Imaging Data Yalin Wang1 , Xianfeng Gu2 , Paul algorithm finds a harmonic map from a 3-manifold to a 3D solid sphere and the second is a novel sphere of magnetic resonance images (MRI). A heat flow method is used to solve the volumetric harmonic mapping
Volumetric Harmonic Brain Mapping using a Variational Method Yalin Wang1
Thompson, Paul
Volumetric Harmonic Brain Mapping using a Variational Method Yalin Wang1 , Xianfeng Gu2 , Tony F investigation of 3D volumetric brain harmonic mapping. By transforming the full 3D brain volume to a solid volume to another. We suggest that 3D harmonic mapping of brain volumes to a solid sphere can provide
High harmonic generation in relativistic laserplasma interactiona... S. Banerjee,b)
Umstadter, Donald
High harmonic generation in relativistic laserÂplasma interactiona... S. Banerjee,b) A. R of Michigan, Ann Arbor, Michigan 48109 Received 2 November 2001; accepted 26 February 2002 High harmonics, in addition to the conventional atomic harmonics from bound electrons there is significant contribution
Harmonic Modelling of Thyristor Bridges using a Simplified Time Domain Method
Lehn, Peter W.
1 Harmonic Modelling of Thyristor Bridges using a Simplified Time Domain Method P. W. Lehn, Senior form solution for the harmonic injection of the converter is developed. For the more general case model module takes as input the ac voltage harmonics at the point of common coupling and outputs
Giant higher harmonic generation in mesoscopic metal wires and rings interrupted by tunnel junctions
van Oudenaarden, Alexander
Giant higher harmonic generation in mesoscopic metal wires and rings interrupted by tunnel 5046, 2600 GA Delft, The Netherlands Received 19 December 1997 Higher harmonic generation in mesoscopic is biased with a sinusoidal varying current, we observe giant higher harmon- ics in the conductance
Harmonic Analysis of a Three-Phase Diode Bridge Rectifier based on Sampled-Data Model
Lehn, Peter W.
Harmonic Analysis of a Three-Phase Diode Bridge Rectifier based on Sampled-Data Model K. L. Lian. As demonstrated in the paper, the proposed method analytically evaluates harmonics, and obtains exact switching is to incorporate it into a harmonic power flow program to yield improved accuracy. Index Terms-- Diode Bridge
Nonlinear harmonic generation and devices in doubly resonant Kerr cavities Hila Hashemi,1
Nonlinear harmonic generation and devices in doubly resonant Kerr cavities Hila Hashemi,1 Alejandro of the nonlinear dynamics of third-harmonic generation 3 via Kerr 3 nonlinearities in a resonant cavity harmonic generation, by a factor of V/Q2 , where V is the modal volume and Q is the lifetime, and can even
1 1 A Harmonic Approach for Calculating Daily Temperature Normals Constrained by2 Homogenized a constrained harmonic technique that forces the daily30 temperature normals to be consistent with the monthly, or harmonic even though the annual march of temperatures for some locations can be highly asymmetric. Here, we
HARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE
Wurtele, Jonathan
HARMONIC CASCADE FEL DESIGNS FOR LUX, A FACILTY FOR ULTRAFAST X-RAY SCIENCE J. Corlett, W. Fawley. We also discuss lattice considerations pertinent to harmonic cascade FELs, somesensitivity studies. While much of this effort has been concentrated upon SASE-based FEL's, there is an alternative "harmonic
Harmonic phase-dispersion microscope with a MachZehnder interferometer
Fang-Yen, Christopher
Harmonic phase-dispersion microscope with a MachÂZehnder interferometer Andrew Ahn, Changhuei Yang S. Feld Harmonic phase-dispersion microscopy (PDM) is a new imaging technique in which contrast is provided by differences in refractive index at two harmonically related wavelengths. We report a new
Very-high-order harmonic generation from Ar atoms and Ar+ ions in superintense pulsed laser
Chu, Shih-I
Very-high-order harmonic generation from Ar atoms and Ar+ ions in superintense pulsed laser fields-high-order harmonic generation HHG from Ar atoms and Ar+ ions by means of the self-interaction-free time-order harmonic generation HHG is one of the most rapidly developing topics in the field of laser-atom molecule
Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations
Wu, Shin-Tson
Second and Fourth Harmonic Frequencies in Electric Field-Induced Liquid Crystal Reorientations of Central Florida, Orlando, Florida, USA The second and fourth harmonics of low frequency electric field-optical modulation; liquid crystal; second and fourth harmonics 1. INTRODUCTION Nematic liquid crystal (LC) has been
High-harmonic generation in plasmas from relativistic laser-electron scattering
Umstadter, Donald
High-harmonic generation in plasmas from relativistic laser-electron scattering S. Banerjee, A. R Results are presented on the generation of high harmonics through the scattering of relativistic electrons to be the emission of even- order harmonics, linear dependence on the electron density, significant amount
Ultrafast Third Harmonic Micro-spectroscopy Reveals a Two-Photon Resonance in Human Hemoglobin
Kleinfeld, David
Ultrafast Third Harmonic Micro-spectroscopy Reveals a Two-Photon Resonance in Human Hemoglobin G Golden, CO 80401 Abstract The recently developed technique of ultrafast third harmonic generation (THG states in physiological solutions of human hemoglobin. Keywords: Third Harmonic Generation, Micro
Geist, Dennis
Search for Harmonic tremor in the Galapagos Jonathan M. Lees, University of North Carolina, Chapel Hill Harmonic volcano tremor can provide details of conduit physics during magma flow and volcano.71.2 Hz. Harmonic tremor has not been reported on Galapagos volcanoes, possibly because seismic
Structural distortions in 5-10 nm silver nanoparticles under high pressure
Koski, Kristie J.; Kamp, Noelle M.; Kunz, Martin; Knight, Jason K.; Alivisatos, A.P.; Smith, R.K.
2008-10-13T23:59:59.000Z
We present experimental evidence that silver nanoparticles in the size range of 5-10 nm undergo a reversible structural transformation under hydrostatic pressures up to 10 GPa. We have used x-ray diffraction with a synchrotron light source to investigate pressure-dependent and size-dependent trends in the crystal structure of silver nanoparticles in a hydrostatic medium compressed in a diamond-anvil cell. Results suggest a reversible linear pressure-dependent rhombohedral distortion which has not been previously observed in bulk silver. We propose a mechanism for this transition that considers the bond-length distribution in idealized multiply twinned icosahedral particles. To further support this hypothesis, we also show that similar measurements of single-crystal platinum nanoparticles reveal no such distortions.
Distortion-free magnetic resonance imaging in the zero-field limit
Kelso, Nathan; Lee, Seung-Kyun; Bouchard, Louis-S.; Demas, Vasiliki; Muck, Michael; Pines, Alexander; Clarke, John
2009-07-09T23:59:59.000Z
MRI is a powerful technique for clinical diagnosis and materials characterization. Images are acquired in a homogeneous static magnetic field much higher than the fields generated across the field of view by the spatially encoding field gradients. Without such a high field, the concomitant components of the field gradient dictated by Maxwell's equations lead to severe distortions that make imaging impossible with conventional MRI encoding. In this paper, we present a distortion-free image of a phantom acquired with a fundamentally different methodology in which the applied static field approaches zero. Our technique involves encoding with pulses of uniform and gradient field, and acquiring the magnetic field signals with a SQUID. The method can be extended to weak ambient fields, potentially enabling imaging in the Earth's field without cancellation coils or shielding. Other potential applications include quantum information processing and fundamental studies of long-range ferromagnetic interactions.
BPM Button Optimization to Minimize Distortion Due to Trapped Mode Heating
Cameron,P.; Blednyk, A.; Kosciuk, B.; Pinayev, I.; Ravindranath, I.; Singh, O
2009-05-04T23:59:59.000Z
The outer circumference of a BPM button and the inner circumference of the button housing comprise a transmission line. This transmission line typically presents an impedance of a few tens of ohms to the beam, and couples very weakly to the 50 ohm coaxial transmission line that comprises the signal path out of the button. The modes which are consequently excited and trapped often have quality factors of several hundred, permitting resonant excitation by the beam. The thermal distortion resulting from trapped mode heating is potentially problematic for achieving the high precision beam position measurements needed to provide the sub-micron beam position stability required by light source users. We present a button design that has been optimized via material selection and component geometry to minimize both the trapped mode heating and the resulting thermal distortion.
Analytical Model of Tidal Distortion and Dissipation for a Giant Planet with a Viscoelastic Core
Storch, Natalia I
2015-01-01T23:59:59.000Z
We present analytical expressions for the tidal Love numbers of a giant planet with a solid core and a fluid envelope. We model the core as a uniform, incompressible, elastic solid, and the envelope as a non-viscous fluid satisfying the $n=1$ polytropic equation of state. We discuss how the Love numbers depend on the size, density, and shear modulus of the core. We then model the core as a viscoelastic Maxwell solid and compute the tidal dissipation rate in the planet as characterized by the imaginary part of the Love number $k_2$. Our results improve upon existing calculations based on planetary models with a solid core and a uniform ($n=0$) envelope. Our analytical expressions for the Love numbers can be applied to study tidal distortion and viscoelastic dissipation of giant planets with solid cores of various rheological properties, and our general method can be extended to study tidal distortion/dissipation of super-earths.
Study on higher harmonic suppression using edge filter and polished Si wafer
Gupta, R. K., E-mail: rkg@rrcat.gov.in; Singh, Amol, E-mail: rkg@rrcat.gov.in; Modi, Mohammed H., E-mail: rkg@rrcat.gov.in; Lodha, G. S., E-mail: rkg@rrcat.gov.in [X-ray Optics Section, ISU Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)
2014-04-24T23:59:59.000Z
Higher harmonics contamination is a severe problem in synchrotron beamlines where grating monochromators are used. In these beamlines, absorption edge filters and critical angle mirrors are used to suppress the harmonic contaminations. In the present study, carried out using Indus-1 reflectivity beamline, a harmonic suppression characteristic of Al edge filter and polished silicon wafer are determined. It is found that the Al filter suppresses higher harmonics in 2–7% range whereas the polished silicon wafer can suppress the higher harmonics below 1%. The results of comparative study are discussed.
Optic for industrial endoscope/borescope with narrow field of view and low distortion
Stone, Gary F.; Trebes, James E.
2005-08-16T23:59:59.000Z
An optic for the imaging optics on the distal end of a flexible fiberoptic endoscope or rigid borescope inspection tool. The image coverage is over a narrow (<20 degrees) field of view with very low optical distortion (<5% pin cushion or barrel distortion), compared to the typical <20% distortion. The optic will permit non-contact surface roughness measurements using optical techniques. This optic will permit simultaneous collection of selected image plane data, which data can then be subsequently optically processed. The image analysis will yield non-contact surface topology data for inspection where access to the surface does not permit a mechanical styles profilometer verification of surface topology. The optic allows a very broad spectral band or range of optical inspection. It is capable of spectroscopic imaging and fluorescence induced imaging when a scanning illumination source is used. The total viewing angle for this optic is 10 degrees for the full field of view of 10 degrees, compared to 40-70 degrees full angle field of view of the conventional gradient index or GRIN's lens systems.
Axion production and CMB spectral distortion in cosmological tangled magnetic field
Damian Ejlli
2015-04-01T23:59:59.000Z
Axion production due to photon-axion mixing in tangled magnetic field(s) prior to recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, contribution of both processes to CMB $\\mu$ distortion in the case of resonant photon-axion mixing is studied. Assuming that magnetic field power spectrum is approximated by a power law $P_B(k)\\propto k^n$ with spectral index $n$, it is shown that for magnetic field cut-off scales $172.5$ pc $\\leq \\lambda_B\\leq 4\\times 10^3$ pc, axion contribution to CMB $\\mu$ distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using COBE upper limit on $\\mu$ and for magnetic field scale $\\lambda_B\\simeq 415$ pc, weaker limit in comparison with other studies on the magnetic field strength ($B_0\\leq 8.5\\times 10^{-8}$ G) up to a factor 10 for the DFSZ axion model and axion mass $m_a\\geq 2.6\\times 10^{-6}$ eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on $\\mu$ is also presented.
Bounds on QCD axion mass and primordial magnetic field from CMB $?$-distortion
Damian Ejlli
2014-11-19T23:59:59.000Z
The oscillation of the CMB photons into axions can cause CMB spectral distortion in the presence of large scale magnetic field. With the COBE limit on the $\\mu$ parameter and a homogeneous magnetic field with strength $B\\lesssim 3.2$ nG at the horizon scale, stronger lower limit on the axion mass in comparison with the limit of the ADMX experiment is found to be, $4.8\\times 10^{-5}$ eV $\\lesssim m_a$ for the KSVZ axion model. On the other hand, using the experimental limit on the axion mass $3.5\\times 10^{-6}$ eV $\\lesssim m_a$ from the ADMX experiment together with the COBE bound on $\\mu$, is found $B\\lesssim 53$ nG for the KSVZ axion model and $B\\lesssim 141$ nG for DFSZ axion model, for a homogeneous magnetic field with coherence length at the present epoch $\\lambda_B\\sim 1.3$ Mpc. Limits on $B$ and $m_a$ for PIXIE/PRISM expected sensitivity on $\\mu$ are derived. If CMB $\\mu$ distortion would be detected by the future space missions PIXIE/PRISM and assuming that the strength of the large scale magnetic field is close to its canonical value, $B\\sim 1-3$ nG, axions in the mass range $2\\, \\mu$eV - $3\\, \\mu$eV would be potential candidates of CMB $\\mu$-distortion.
Axion production and CMB spectral distortion in cosmological tangled magnetic field
Ejlli, Damian
2015-01-01T23:59:59.000Z
Axion production due to photon-axion mixing in tangled magnetic field(s) prior to recombination epoch and magnetic field damping can generate cosmic microwave background (CMB) spectral distortions. In particular, contribution of both processes to CMB $\\mu$ distortion in the case of resonant photon-axion mixing is studied. Assuming that magnetic field power spectrum is approximated by a power law $P_B(k)\\propto k^n$ with spectral index $n$, it is shown that for magnetic field cut-off scales $172.5$ pc $\\leq \\lambda_B\\leq 4\\times 10^3$ pc, axion contribution to CMB $\\mu$ distortion is subdominant in comparison with magnetic field damping in the cosmological plasma. Using COBE upper limit on $\\mu$ and for magnetic field scale $\\lambda_B\\simeq 415$ pc, weaker limit in comparison with other studies on the magnetic field strength ($B_0\\leq 8.5\\times 10^{-8}$ G) up to a factor 10 for the DFSZ axion model and axion mass $m_a\\geq 2.6\\times 10^{-6}$ eV is found. A forecast for the expected sensitivity of PIXIE/PRISM on...
Sarshar, A. [Trench Electric, Scarborough, Ontario (Canada)] [Trench Electric, Scarborough, Ontario (Canada); Iravani, M.R.; Li, J. [Univ. of Toronto, Ontario (Canada). Dept. of Electrical and Computer Engineering] [Univ. of Toronto, Ontario (Canada). Dept. of Electrical and Computer Engineering
1996-01-01T23:59:59.000Z
In this paper, noncharacteristic harmonics of an HVdc converter station are calculated based on the use of digital time-domain simulation methods. An enhanced version of the Electromagnetic Transients Program (EMTP) is used for the studies. The noncharacteristic harmonics of interest are (1) the dc side triplen harmonics, and (2) the ac side second harmonic. Impacts of loading conditions, neutral filter, and converter firing angle on the dc side triplen harmonics are discussed. Effects of ac side network parameters, static VAR compensator (SVC), transformer half-cycle saturation, and Geomagnetically Induced Current (GIC) on the ac side second harmonic instability are also presented. This paper concludes that the digital time-domain simulation method provides significant flexibility for accurate prediction of (1) generation mechanism, and (2) adverse impacts of HVdc noncharacteristic harmonics.
Park, Sang-Hoon, Ph. D. Massachusetts Institute of Technology
2004-01-01T23:59:59.000Z
We report measurements of the temperature and power dependence of the microwave frequency intermodulation distortion (IMD) in high quality pulsed laser deposition (PLD) Yttrium Barium Copper Oxide (YBCO) on LaAlO3 substrate. ...
Konkola, Paul Thomas, 1973-
2003-01-01T23:59:59.000Z
This thesis describes the design and analysis of a system for patterning large-area gratings with nanometer level phase distortions. The novel patterning method, termed scanning beam interference lithography (SBIL), uses ...
Wang, Gaozhong; Zhang, Saifeng, E-mail: sfzhang@siom.ac.cn, E-mail: jwang@siom.ac.cn; Cheng, Xin; Dong, Ningning; Zhang, Long; Wang, Jun, E-mail: sfzhang@siom.ac.cn, E-mail: jwang@siom.ac.cn [Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Umran, Fadhil A. [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Institute of Laser for Post Graduate Studies, Baghdad University, Baghdad (Iraq); Coghlan, Darragh; Blau, Werner J. [Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physics and the Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland); Cheng, Ya [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)
2014-04-07T23:59:59.000Z
Spatial self-phase modulation (SSPM) was observed directly when a focused He-Ne laser beam at 633?nm went through liquid-phase-exfoliated graphene dispersions. The diffraction pattern of SSPM was found to be distorted rapidly right after the incident beam horizontally passing through the dispersions, while no distortion for the vertically incident geometry. We show that the distortion is originated mainly from the non-axis-symmetrical thermal convections of the graphene nanosheets induced by laser heating, and the relative change of nonlinear refractive index can be determined by the ratio of the distortion angle to the half-cone angle. Therefore, the effective nonlinear refractive index of graphene dispersions can be tuned by changing the incident intensity and the temperature of the dispersions.
Completion report harmonic analysis of electrical distribution systems
Tolbert, L.M.
1996-03-01T23:59:59.000Z
Harmonic currents have increased dramatically in electrical distribution systems in the last few years due to the growth in non-linear loads found in most electronic devices. Because electrical systems have been designed for linear voltage and current waveforms; (i.e. nearly sinusoidal), non-linear loads can cause serious problems such as overheating conductors or transformers, capacitor failures, inadvertent circuit breaker tripping, or malfunction of electronic equipment. The U.S. Army Center for Public Works has proposed a study to determine what devices are best for reducing or eliminating the effects of harmonics on power systems typical of those existing in their Command, Control, Communication and Intelligence (C3I) sites.
All-Optical Field-Induced Second-Harmonic Generation
Davidson, Roderick B; Ziegler, Jed I; Avanesyan, Sergey M; Lawrie, Ben J; Haglund, Richard F
2015-01-01T23:59:59.000Z
Efficient frequency modulation techniques are crucial to the development of plasmonic metasurfaces for information processing and energy conversion. Nanoscale electric-field confinement in optically pumped plasmonic structures enables stronger nonlinear susceptibilities than are attainable in bulk materials. The interaction of three distinct electric fields in (chi)^3 optical processes allows for all-optical modulation of nonlinear signals. Here we demonstrate effcient third-order second harmonic generation (SHG) in a serrated nanogap plasmonic geometry that generates steep electric field gradients within a dielectric material. We utilize an ultrafast optical pump to control the plasmonically induced electric-fields and to generate bandwidth-limited ultrafast second-harmonic pulses driven by the control pulses. The combination of plasmonic metasurfaces with all-optical control and the freedom to choose the dielectric allow multiple generalizations of this concept and geometry to other four-wave mixing process...
Freely floating structures trapping time-harmonic water waves (revisited)
Nikolay Kuznetsov; Oleg Motygin
2014-10-22T23:59:59.000Z
We study the coupled small-amplitude motion of the mechanical system consisting of infinitely deep water and a structure immersed in it. The former is bounded above by a free surface, whereas the latter is formed by an arbitrary finite number of surface-piercing bodies floating freely. The mathematical model of time-harmonic motion is a spectral problem in which the frequency of oscillations serves as the spectral parameter. It is proved that there exist axisymmetric structures consisting of $N \\geq 2$ bodies; every structure has the following properties: (i) a time-harmonic wave mode is trapped by it; (ii) some of its bodies (may be none) are motionless, whereas the rest of the bodies (may be none) are heaving at the same frequency as water. The construction of these structures is based on a generalization of the semi-inverse procedure applied earlier for obtaining trapping bodies that are motionless although float freely.
Damping the zero-point energy of a harmonic oscillator
T. G Philbin; S. A. R. Horsley
2013-07-31T23:59:59.000Z
The physics of quantum electromagnetism in an absorbing medium is that of a field of damped harmonic oscillators. Yet until recently the damped harmonic oscillator was not treated with the same kind of formalism used to describe quantum electrodynamics in a arbitrary medium. Here we use the techniques of macroscopic QED, based on the Huttner--Barnett reservoir, to describe the quantum mechanics of a damped oscillator. We calculate the thermal and zero-point energy of the oscillator for a range of damping values from zero to infinity. While both the thermal and zero-point energies decrease with damping, the energy stored in the oscillator at fixed temperature increases with damping, an effect that may be experimentally observable. As the results follow from canonical quantization, the uncertainty principle is valid for all damping levels.
Higher signal harmonics, LISA's angular resolution, and dark energy
K. G. Arun; Bala R. Iyer; B. S. Sathyaprakash; Siddhartha Sinha; Chris Van Den Broeck
2007-10-24T23:59:59.000Z
It is generally believed that the angular resolution of the Laser Interferometer Space Antenna (LISA) for binary supermassive black holes (SMBH) will not be good enough to identify the host galaxy or galaxy cluster. This conclusion, based on using only the dominant harmonic of the binary SMBH signal, changes substantially when higher signal harmonics are included in assessing the parameter estimation problem. We show that in a subset of the source parameter space the angular resolution increases by more than a factor of 10, thereby making it possible for LISA to identify the host galaxy/galaxy cluster. Thus, LISA's observation of certain binary SMBH coalescence events could constrain the dark energy equation of state to within a few percent, comparable to the level expected from other dark energy missions.
Gou, Jian
1992-01-01T23:59:59.000Z
. (August 1992) Jian Gou, B. S. E. E. , Shanghai Jiao Tong Ilniversity Chair of Advisory Committee. Dr. P. Enjeti The general drive towards automation has increased the use of harmonic generating loads both by residential as well as industrial consumers... The examples of these loads in home and industry are: heating ventilation and air conditioning equipment (HVAC); electric kitchen apphances; electric arc furnaces; variable speed dc and ac drives, etc Since the equipment of this kind provides the users...
Discrete quadratic solitons with competing second-harmonic components
Setzpfandt, Frank; Pertsch, Thomas [Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, D-07743 Jena (Germany); Sukhorukov, Andrey A. [Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra, 0200 ACT (Australia)
2011-11-15T23:59:59.000Z
We describe families of discrete solitons in quadratic waveguide arrays supported by competing cascaded nonlinear interactions between one fundamental and two second-harmonic modes. We characterize the existence, stability, and excitation dynamics of these solitons and show that their features may resemble those of solitons in saturable media. Our results also demonstrate that a power threshold may appear for soliton formation, leading to a suppression of beam self-focusing which explains recent experimental observations.
SU(3) symmetry in the triaxially deformed harmonic oscillator
Sugawara-Tanabe, Kazuko [Otsuma Women's University, Tama, Tokyo 206-8540 (Japan); Tanabe, Kosai [Department of Physics, Saitama University, Sakura-Ku, Saitama 338-8570 (Japan); Theoretical Nuclear Physics Laboratory, RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Arima, Akito [Science Museum, Japan Science Foundation, Tokyo 102-0091 (Japan); Gruber, Bruno [College of Science, Southern Illinois University, Carbondale, Illinois 62901 (United States)
2009-10-15T23:59:59.000Z
An anisotropic harmonic oscillator Hamiltonian can be brought into invariant form under SU(3) transformations by applying nonlinear transformations to the oscillator bosons. The classification of the single-particle levels based on this covering group predicts magic numbers for the triaxial oscillator. It is shown that when the deformation |{delta}| is not too large, the physical operators are approximated by the group operators. Estimation is carried out for the alignment of orbital angular momentum in a triaxial field.
Vacuum high harmonic generation in the shock regime
Böhl, P; Ruhl, H
2015-01-01T23:59:59.000Z
Electrodynamics becomes nonlinear and permits the self-interaction of fields when the quantised nature of vacuum states is taken into account. The effect on a plane probe pulse propagating through a stronger constant crossed background is calculated using numerical simulation and by analytically solving the corresponding wave equation. The electromagnetic shock resulting from vacuum high harmonic generation is investigated and a nonlinear shock parameter identified.
Harmonic oscillator in a one-dimensional box
Paolo Amore; Francisco M. Fernandez
2009-07-31T23:59:59.000Z
We study a harmonic molecule confined to a one--dimensional box with impenetrable walls. We explicitly consider the symmetry of the problem for the cases of different and equal masses. We propose suitable variational functions and compare the approximate energies given by the variation method and perturbation theory with accurate numerical ones for a wide range of values of the box length. We analyze the limits of small and large box size.
Conduction-Band-Offset Rule Governing J-V Distortion in CdS/CI(G)S Solar Cells
Sites, James R.
Conduction-Band-Offset Rule Governing J-V Distortion in CdS/CI(G)S Solar Cells A. Kanevce, MV at the n/p interface of a solar cell can lead to significant distortion of the current-voltage (J-V) curve-layer [TCO/CdS/CI(G)S] approximation for the solar cell. The parameters that influence the barrier height
Efficient Forward Second-Harmonic Generation from Planar Archimedean Nanospirals
Davidson, Roderick B; Vargas, Guillermo; Avanesyan, Sergey M; Haglund, Richard F
2015-01-01T23:59:59.000Z
The enhanced electric field at plasmonic resonances in nanoscale antennas can lead to efficient harmonic generation, especially when the plasmonic geometry is asymmetric on either inter-particle or intra-particle levels. The planar Archimedean nanospiral offers a unique geometrical asymmetry for second-harmonic generation (SHG) because the SHG results neither from arranging centrosymmetric nanoparticles in asymmetric groupings, nor from non-centrosymmetric nanoparticles that retain a local axis of symmetry. Here we report forward SHG from planar arrays of Archimedean nanospirals using 15 fs pulse from a Ti:sapphire oscillator tuned to 800 nm wavelength. The measured harmonic-generation efficiencies are 2.6*10-9, 8*10-9 and 1.3*10-8 for left-handed circular, linear, and right-handed circular polarizations, respectively. The uncoated nanospirals are stable under average power loading of as much as 300 uW per nanoparticle. The nanospirals also exhibit a selective conversion between polarization states. These exp...
High harmonic generation from Bloch electrons in solids
Wu, Mengxi; Reis, David A; Schafer, Kenneth J; Gaarde, Mette B
2015-01-01T23:59:59.000Z
We study the generation of high harmonic radiation by Bloch electrons in a model transparent solid driven by a strong mid-infrared laser field. We solve the single-electron time-dependent Schr\\"odinger equation (TDSE) using a velocity-gauge method [New J. Phys. 15, 013006 (2013)] that is numerically stable as the laser intensity and number of energy bands are increased. The resulting harmonic spectrum exhibits a primary plateau due to the coupling of the valence band to the first conduction band, with a cutoff energy that scales linearly with field strength and laser wavelength. We also find a weaker second plateau due to coupling to higher-lying conduction bands, with a cutoff that is also approximately linear in the field strength. To facilitate the analysis of the time-frequency characteristics of the emitted harmonics, we also solve the TDSE in a time-dependent basis set, the Houston states [Phys. Rev. B 33, 5494 (1986)], which allows us to separate inter-band and intra-band contributions to the time-depe...
Background and Reflections on the Life Cycle Assessment Harmonization Project
Heath, G. A.; Mann, M. K.
2012-04-01T23:59:59.000Z
Despite the ever-growing body of life cycle assessment (LCA) literature on electricity generation technologies, inconsistent methods and assumptions hamper comparison across studies and pooling of published results. Synthesis of the body of previous research is necessary to generate robust results to assess and compare environmental performance of different energy technologies for the benefit of policy makers, managers, investors, and citizens. With funding from the U.S. Department of Energy, the National Renewable Energy Laboratory initiated the LCA Harmonization Project in an effort to rigorously leverage the numerous individual studies to develop collective insights. The goals of this project were to: (1) understand the range of published results of LCAs of electricity generation technologies, (2) reduce the variability in published results that stem from inconsistent methods and assumptions, and (3) clarify the central tendency of published estimates to make the collective results of LCAs available to decision makers in the near term. The LCA Harmonization Project's initial focus was evaluating life cycle greenhouse gas (GHG) emissions from electricity generation technologies. Six articles from this first phase of the project are presented in a special supplemental issue of the Journal of Industrial Ecology on Meta-Analysis of LCA: coal (Whitaker et al. 2012), concentrating solar power (Burkhardt et al. 2012), crystalline silicon photovoltaics (PVs) (Hsu et al. 2012), thin-film PVs (Kim et al. 2012), nuclear (Warner and Heath 2012), and wind (Dolan and Heath 2012). Harmonization is a meta-analytical approach that addresses inconsistency in methods and assumptions of previously published life cycle impact estimates. It has been applied in a rigorous manner to estimates of life cycle GHG emissions from many categories of electricity generation technologies in articles that appear in this special supplemental supplemental issue, reducing the variability and clarifying the central tendency of those estimates in ways useful for decision makers and analysts. Each article took a slightly different approach, demonstrating the flexibility of the harmonization approach. Each article also discusses limitations of the current research, and the state of knowledge and of harmonization, pointing toward a path of extending and improving the meta-analysis of LCAs.
Structural distortion in RPt sub 2 Sn sub 2 compounds (R = rare earth)
Latroche, M.; Selsane, M.; Godart, C.; Schiffmacher, G. (Centre National de la Recherche Scientifique (CNRS), 92 - Meudon-Bellevue (France)); Beyerman, W.P.; Thompson, J.D. (Los Alamos National Lab., NM (USA))
1991-01-01T23:59:59.000Z
CeM{sub 2}X{sub 2} compounds (M-transition metals, X = Si, Ge, Sn) exhibit very exotic properties such as intermediate valence state, heavy fermion, magnetism, and superconductivity. Most of them crystallize in the ThCr{sub 2}Si{sub 2} type structure (14/nmm) while a few adopt the CeBe{sub 2}Ge{sub 2} primitive one (P4/nmmm). Among these compounds, CePt{sub 2}Sn{sub 2} has the heaviest known specific heat coefficient ({gamma} = 3.5 J/mol-K{sup 2}) and orders antiferromagnetically at T{sub N} = 0.88 K. Samples of CePt{sub 2}Sn{sub 2}, Ce{sub 0.e}La{sub 0.2}Pt{sub 2}Sn{sub 2}, and LaPt{sub 2}Sn{sub 2} have been studied by X-ray powder diffraction experiments including Rietveld calculations before and after annealing. As-cast samples can be indexed in the tetragonal primitive cell; however, re- examination of annealed samples (1 3 days at 800{degrees}C and 3 weeks at 700{degrees}C) reveals a monoclinic distortion of the lattice. Such a distortion has already been observed for CeNi{sub 2}Sn{sub 2}. Furthermore, our diffraction patterns show evidence for superlattice lines at twice the unit cell parameters, which was verified by transmission electron microscopy. Microprobes analysis on these samples show that the Pt sublattice is slightly substoichiometric (97.5%). Thus strains due to large atomic radii and ordering of Pt vacancies could be responsible for the monoclinic distortion and superlattice lines. 13 refs., 3 figs., 1 tab.
Comaskey, Brian J. (Walnut Creek, CA); Ault, Earl R. (Livermore, CA); Kuklo, Thomas C. (Oakdale, CA)
2005-07-05T23:59:59.000Z
A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.
A vector field method on the distorted Fourier side and decay for wave equations with potentials
Roland Donninger; Joachim Krieger
2014-06-03T23:59:59.000Z
We study the Cauchy problem for the one-dimensional wave equation with an inverse square potential. We derive dispersive estimates, energy estimates, and estimates involving the scaling vector field, where the latter are obtained by employing a vector field method on the "distorted" Fourier side. In addition, we prove local energy decay estimates. Our results have immediate applications in the context of geometric evolution problems. The theory developed in this paper is fundamental for the proof of the co-dimension 1 stability of the catenoid under the vanishing mean curvature flow in Minkowski space.
Guo, Qixum [Los Alamos National Laboratory; Zhao, Yusheng [Los Alamos National Laboratory; Zin, Zhijun [Los Alamos National Laboratory; Wang, Zhongwu [CORNELL UNIV; Skrabalak, Sara E [INDIANA UNIV; Xia, Younan [WASHINGTON UNIV
2008-01-01T23:59:59.000Z
Silver micro- and nanocrystals with sizes of {approx}2--3.5 {mu}m and {approx}50--100 nm were uniaxially compressed under nonhydrostatic pressures (strong deviatoric stress) up to {approx}30 GPa at room temperature in a symmetric diamond-anvil cell and studied in situ using angle-dispersive synchrotron X-ray diffraction. A cubic to trigonal structural distortion along a 3-fold rotational axis was discovered by careful and comprehensive analysis of the apparent lattice parameter and full width at half-maximum, which are strongly dependent upon the Miller index and crystal size.
Anisotropies in Non-Thermal Distortions of Cosmic Light from Photon-Axion Conversion
Guido D'Amico; Nemanja Kaloper
2015-01-07T23:59:59.000Z
Ultralight axions which couple sufficiently strongly to photons can leave imprints on the sky at diverse frequencies by mixing with cosmic light in the presence of background magnetic fields. We explore such direction dependent grey-body distortions of the CMB spectrum, enhanced by resonant conditions in the IGM plasma. We also find that if such axions are produced in the early universe and represent a subdominant dark radiation component today, they could convert into X-rays in supervoids, and brighten them at X-ray frequencies.
Anisotropies in Non-Thermal Distortions of Cosmic Light from Photon-Axion Conversion
D'Amico, Guido
2015-01-01T23:59:59.000Z
Ultralight axions which couple sufficiently strongly to photons can leave imprints on the sky at diverse frequencies by mixing with cosmic light in the presence of background magnetic fields. We explore such direction dependent grey-body distortions of the CMB spectrum, enhanced by resonant conditions in the IGM plasma. We also find that if such axions are produced in the early universe and represent a subdominant dark radiation component today, they could convert into X-rays in supervoids, and brighten them at X-ray frequencies.
Composite resonance: A circuit approach to the waveform distortion dynamics of an HVdc converter
Wood, A.R.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand)] [Univ. of Canterbury, Christchurch (New Zealand)
1995-10-01T23:59:59.000Z
A frequency domain analysis is applied to a controlled HVdc converter interconnecting ac and dc networks. The converter is considered as a three port network, and described using transfer functions. Using ac and dc system frequency dependent impedances an equivalent electrical circuit is constructed. The concept of composite resonance is introduced to emphasize the interaction between the ac and dc systems, and a simplified damping factor derived to predict the dynamics of waveform distortion during transient recovery. The frequency domain analysis is verified by dynamic simulation.
Braenzel, J.; Schnürer, M.; Steinke, S.; Priebe, G.; Sandner, W. [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany)] [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany); Andreev, A. [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany) [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin (Germany); Vavilov State Optical Institute, Birzhevaya line 4, 199034 St. Petersburg (Russian Federation); Platonov, K. [Vavilov State Optical Institute, Birzhevaya line 4, 199034 St. Petersburg (Russian Federation)] [Vavilov State Optical Institute, Birzhevaya line 4, 199034 St. Petersburg (Russian Federation)
2013-08-15T23:59:59.000Z
Theoretical and experimental investigations of the dynamics of a relativistically oscillating plasma slab reveal spectral line splitting in laser driven harmonic spectra, leading to double harmonic series. Both series are well characterized with harmonics arising by two fundamental frequencies. While a relativistic oscillation of the critical density drives the harmonic emission, the splitting is a result of an additional acceleration during the laser pulse duration. In comparison with the oscillatory movement, this acceleration is rather weak and can be described by a plasma shock wave driven by the pressure of light. We introduce particle in cell simulations and an analytical model explaining the harmonic line splitting. The derived analytical formula gives direct access between the splitting in the harmonic spectrum and the acceleration of the plasma surface.
Physics 221B: Solution to HW # 6 1) Born-Oppenheimer for Coupled Harmonic Oscil-
Murayama, Hitoshi
Physics 221B: Solution to HW # 6 1) Born-Oppenheimer for Coupled Harmonic Oscil- lators model of coupled 1D harmonic oscilla- tors. Since we know how to solve the system exactly we can compare + 1 2 k(X2 - x3 - d)2 . Combining into one harmonic oscillator we get H = p2 3 2m + 1 2 2k x3 - X1 + X
Half-harmonic Kelvin probe force microscopy with transfer function correction
Guo, Senli [ORNL] [ORNL; Jesse, Stephen [ORNL] [ORNL; Kalinin, Sergei V [ORNL] [ORNL
2012-01-01T23:59:59.000Z
An approach for surface potential imaging based on half-harmonic band excitation (BE) in Kelvin probe force microscopy is demonstrated. Using linear and half-harmonic BE enables quantitative correction of the cantilever transfer function. Half-harmonic band excitation Kelvin probe force microscopy (HBE KPFM) thus allows quantitative separation of surface potential and topographic contributions to the signal, obviating the primary sources of topographic cross-talk. HBE KPFM imaging and voltage spectroscopy methods are illustrated for several model systems.
Ramanujan's Harmonic Number Expansion into Negative Powers of a Triangular Number
Mark B. Villarino
2007-07-28T23:59:59.000Z
An algebraic transformation of the DeTemple-Wang half-integer approximation to the harmonic series produces the general formula and error estimate for the Ramanujan expansion for the nth harmonic number into negative powers of the nth triangular number. We also discuss the history of the Ramanujan expansion for the nth harmonic number as well as sharp estimates of its accuracy, with complete proofs, and we compare it with other approximative formulas.
Harmonic oscillator in a background magnetic field in noncommutative quantum phase-space
Joseph Ben Geloun; Sunandan Gangopadhyay; Frederik G Scholtz
2009-01-22T23:59:59.000Z
We solve explicitly the two-dimensional harmonic oscillator and the harmonic oscillator in a background magnetic field in noncommutative phase-space without making use of any type of representation. A key observation that we make is that for a specific choice of the noncommutative parameters, the time reversal symmetry of the systems get restored since the energy spectrum becomes degenerate. This is in contrast to the noncommutative configuration space where the time reversal symmetry of the harmonic oscillator is always broken.
Hussain, S. [Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2E1 (Canada); Theoretical Physics Division, PINSTECH, Nilore, Islamabad (Pakistan); Department of Physics and Applied Mathematics, PIEAS, Nilore, Islamabad (Pakistan); Marchand, R. [Department of Physics, University of Alberta, Edmonton, T6G 2E1 Alberta (Canada)
2014-07-15T23:59:59.000Z
We discuss sheath and kinetic effects on ion and electron distribution functions at the aperture of enhanced Polar Outflow Probe particle sensors. For this purpose, the interaction between the CASSIOPE spacecraft and space environment is simulated fully kinetically using the electrostatic Particle In Cell code PTetra. The simulations account for the geometry of the main features of the spacecraft body, the booms, and the sensors. In addition to the background plasma, the model also accounts for Earth magnetic field. The plasma parameters assumed in the simulations are obtained from the latest version of the International Reference Ionosphere (IRI) model and the value of magnetic field is obtained from the International Geophysical Reference Field model. Our analysis shows significant distortions in the ion distribution function in the plane of the sensor aperture, as well as in the direction along the boom holding the sensor. We argue that significant distortions and asymmetries should also occur at the aperture of the suprathermal electron imager when suprathermal electrons are detected, with energies of 5?eV or more.
Welding Induced Alignment Distortion in Dual-in-Line LD Packages
Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Shi, Frank G.
2007-11-11T23:59:59.000Z
The tolerance for the movement of a single mode fiber relative to the laser is extremely tight, a submicron movement can often lead to a significant misalignment and thus the reduction in the power coupled into the fiber. Among various fiber pigtailing assembly technologies, pulsed laser welding is the method with submicron accuracy and is most conducive to automation. However, the melting-solidification process during laser welding can often distort the pre-achieved fiber-optic alignment. This Welding-Induced-Alignment-Distortion (WIAD) is a serious concern and significantly affects the yield for single mode fiber pigtailing to a semiconductor laser. In this paper, effect of laser welding sequence on WIAD in a dual-in-line packager is numerically investigated by means of Finite Element Method (FEM). Optimal welding sequence may minimize WIAD in dual-in-line package. Additionally, unsymmetrical space between fiber and U-channel induced by laser welding of U-channel–to-plate in DIP LD packages is found to have obvious effect on WIAD.
Dispersion-free monochromatization method for selecting a single-order harmonic beam
Takahashi, Eiji J; Ichimaru, Satoshi; Midorikawa, Katsumi
2015-01-01T23:59:59.000Z
We propose a method to monochromatize multiple orders of high harmonics by using a proper designed multilayer mirror. Multilayer mirrors designed by our concept realize the perfect extraction of a single-order harmonic from multiple-order harmonic beam, and exhibit broadband tenability and high reflectivity in the soft-x-ray region. Furthermore, the proposed monochromatization method can preserve the femtosecond to attosecond pulse duration for the reflected beam. This device is very useful for ultrafast soft x-ray experiments that require high-order harmonic beams, such as femtosecond/attosecond, time-resolved, pump-probe spectroscopy.
N = 4 supersymmetric mechanics: Harmonic superspace as a universal tool of model-building
Ivanov, E. A., E-mail: eivanov@theor.jinr.ru [Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics (Russian Federation)
2013-08-15T23:59:59.000Z
We overview applications of the harmonic superspace approach in models of N = 4supersymmetric mechanics, with emphasis on some recent results.
Numerical studies of third-harmonic generation in laser filament in air perturbed by plasma spot
Feng Liubin [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Institute of Atomic and Molecular Physics and Department of Physics, Sichuan University, Chengdu 610065 (China); Lu Xin; Liu Xiaolong; Li Yutong; Chen Liming; Ma Jinglong; Dong Quanli; Wang Weimin [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Xi Tingting [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Sheng Zhengming; Zhang Jie [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Key Laboratory for Laser Plasmas of the Ministry of Education of China and Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); He Duanwei [Institute of Atomic and Molecular Physics and Department of Physics, Sichuan University, Chengdu 610065 (China)
2012-07-15T23:59:59.000Z
Third-harmonic emission from laser filament intercepted by plasma spot is studied by numerical simulations. Significant enhancement of the third-harmonic generation is obtained due to the disturbance of the additional plasma. The contribution of the pure plasma effect and the possible plasma-enhanced third-order susceptibility on the third-harmonic generation enhancement are compared. It is shown that the plasma induced cancellation of destructive interference [Y. Liu et al., Opt. Commun. 284, 4706 (2011)] of two-colored filament is the dominant mechanism of the enhancement of third-harmonic generation.
Analysis and Design of New Harmonic Mitigation Approaches
Aeloiza Matus, Eddy 1972-
2012-11-01T23:59:59.000Z
is proposed to reduce the HF circulating current and a zero-sequence control loop to mitigate the low frequency circulating current is also proposed [56]-[58]. 5 Power Quality Standards 1.2. IEEE 519-1981 [67] 1.2.1 In 1981... to determine whether or not the new converters were going to be a problem. It was impractical and not economical to mitigate the harmonics for each non-linear load. Therefore, the IEEE 519-1981 was designed to help these users with the application...
A non-conforming 3D spherical harmonic transport solver
Van Criekingen, S. [Commissariat a l'Energie Atomique CEA-Saclay, DEN/DM2S/SERMA/LENR Bat 470, 91191 Gif-sur-Yvette, Cedex (France)
2006-07-01T23:59:59.000Z
A new 3D transport solver for the time-independent Boltzmann transport equation has been developed. This solver is based on the second-order even-parity form of the transport equation. The angular discretization is performed through the expansion of the angular neutron flux in spherical harmonics (PN method). The novelty of this solver is the use of non-conforming finite elements for the spatial discretization. Such elements lead to a discontinuous flux approximation. This interface continuity requirement relaxation property is shared with mixed-dual formulations such as the ones based on Raviart-Thomas finite elements. Encouraging numerical results are presented. (authors)
Quantum Energy Teleportation with a Linear Harmonic Chain
Yasusada Nambu; Masahiro Hotta
2010-10-14T23:59:59.000Z
A protocol of quantum energy teleportation is proposed for a one-dimensional harmonic chain. A coherent-state POVM measurement is performed to coupled oscillators of the chain in the ground state accompanied by energy infusion to the system. This measurement consumes a part of ground state entanglement. Depending on the measurement result, a displacement operation is performed on a distant oscillator accompanied by energy extraction from the zero-point fluctuation of the oscillator. We find that the amount of consumed entanglement is bounded from below by a positive value that is proportional to the amount of teleported energy.
The effect of singular potentials on the harmonic oscillator
Filgueiras, C. [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58051-900 Joao Pessoa, PB (Brazil); Silva, E.O. [International Institute of Physics, Universidade Federal do Rio Grande do Norte, Campus Universitario Lagoa Nova, 59.072-970 Natal, RN (Brazil); Oliveira, W. [Departamento de Fisica, Universidade Federal de Juiz de Fora, 36.036-330 Juiz de Fora, MG (Brazil); Moraes, F., E-mail: moraes@fisica.ufpb.b [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58051-900 Joao Pessoa, PB (Brazil)
2010-11-15T23:59:59.000Z
We address the problem of a quantum particle moving under interactions presenting singularities. The self-adjoint extension approach is used to guarantee that the Hamiltonian is self-adjoint and to fix the choice of boundary conditions. We specifically look at the harmonic oscillator added of either a {delta}-function potential or a Coulomb potential (which is singular at the origin). The results are applied to Landau levels in the presence of a topological defect, the Calogero model and to the quantum motion on the noncommutative plane.
Second-harmonic generation in transition-metal-organic compounds
Frazier, C.C.; Harvey, M.A.; Cockerham, M.P.; Hand, H.M.; Chauchard, E.A.; Lee, C.H.
1986-10-23T23:59:59.000Z
The second-harmonic generation efficiencies of over 60 transition-metal-organic compounds in powder form were measured, using 1.06 ..mu..m light from a Nd:YAG laser. Most of the studied compounds were either group VI metal carbonyl arene, pyridyl, or chiral phosphine complexes. Four the complexes doubled the laser fundamental as well as or better than ammonium dihydrogen phosphate (ADP). The study shows that the same molecular features (e.g., conjugation and low-lying spectroscopic charge transfer) that contribute to second-order optical nonlinearity in organic compounds also enhance second-order effects in transition-metal-organic compounds.
Harmonic initial-boundary evolution in general relativity
Babiuc, Maria C. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Szilagyi, Bela [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany); Winicour, Jeffrey [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany)
2006-03-15T23:59:59.000Z
Computational techniques which establish the stability of an evolution-boundary algorithm for a model wave equation with shift are incorporated into a well-posed version of the initial-boundary value problem for gravitational theory in harmonic coordinates. The resulting algorithm is implemented as a 3-dimensional numerical code which we demonstrate to provide stable, convergent Cauchy evolution in gauge wave and shifted gauge wave testbeds. Code performance is compared for Dirichlet, Neumann, and Sommerfeld boundary conditions and for boundary conditions which explicitly incorporate constraint preservation. The results are used to assess strategies for obtaining physically realistic boundary data by means of Cauchy-characteristic matching.
Quantum Energy Teleportation with a Linear Harmonic Chain
Nambu, Yasusada
2010-01-01T23:59:59.000Z
A protocol of quantum energy teleportation is proposed for a one-dimensional harmonic chain. A coherent-state POVM measurement is performed to coupled oscillators of the chain in the ground state accompanied by energy infusion to the system. This measurement consumes a part of ground state entanglement. Depending on the measurement result, a displacement operation is performed on a distant oscillator accompanied by energy extraction from the zero-point fluctuation of the oscillator. We find that the amount of consumed entanglement is bounded from below by a positive value that is proportional to the amount of teleported energy.
Harmonic Initial-Boundary Evolution in General Relativity
Maria C. Babiuc; Bela Szilagyi; Jeffrey Winicour
2006-03-14T23:59:59.000Z
Computational techniques which establish the stability of an evolution-boundary algorithm for a model wave equation with shift are incorporated into a well-posed version of the initial-boundary value problem for gravitational theory in harmonic coordinates. The resulting algorithm is implemented as a 3-dimensional numerical code which we demonstrate to provide stable, convergent Cauchy evolution in gauge wave and shifted gauge wave testbeds. Code performance is compared for Dirichlet, Neumann and Sommerfeld boundary conditions and for boundary conditions which explicitly incorporate constraint preservation. The results are used to assess strategies for obtaining physically realistic boundary data by means of Cauchy-characteristic matching.
On the harmonic oscillator on the Lobachevsky plane
P. Stovicek; M. Tusek
2007-09-24T23:59:59.000Z
We introduce the harmonic oscillator on the Lobachevsky plane with the aid of the potential $V(r)=(a^2\\omega^2/4)sinh(r/a)^2$ where $a$ is the curvature radius and $r$ is the geodesic distance from a fixed center. Thus the potential is rotationally symmetric and unbounded likewise as in the Euclidean case. The eigenvalue equation leads to the differential equation of spheroidal functions. We provide a basic numerical analysis of eigenvalues and eigenfunctions in the case when the value of the angular momentum, $m$, equals 0.
Harmonic coordinates in the string and membrane equations
Chun-Lei He; Shou-Jun Huang
2010-04-16T23:59:59.000Z
In this note, we first show that the solutions to Cauchy problems for two versions of relativistic string and membrane equations are diffeomorphic. Then we investigate the coordinates transformation presented in Ref. [9] (see (2.20) in Ref. [9]) which plays an important role in the study on the dynamics of the motion of string in Minkowski space. This kind of transformed coordinates are harmonic coordinates, and the nonlinear relativistic string equations can be straightforwardly simplified into linear wave equations under this transformation.
Generalized energy equipartition in harmonic oscillators driven by active baths
Claudio Maggi; Matteo Paoluzzi; Nicola Pellicciotta; Alessia Lepore; Luca Angelani; Roberto Di Leonardo
2014-11-06T23:59:59.000Z
We study experimentally and numerically the dynamics of colloidal beads confined by a harmonic potential in a bath of swimming E. coli bacteria. The resulting dynamics is well approximated by a Langevin equation for an overdamped oscillator driven by the combination of a white thermal noise and an exponentially correlated active noise. This scenario leads to a simple generalization of the equipartition theorem resulting in the coexistence of two different effective temperatures that govern dynamics along the flat and the curved directions in the potential landscape.
Temperature-insensitive phase-matched optical harmonic conversion crystal
Barker, C.E.; Eimerl, D.; Velsko, S.P.; Roberts, D.
1993-11-23T23:59:59.000Z
Temperature-insensitive, phase-matched harmonic frequency conversion of laser light at a preferred wavelength of 1.064 microns can be achieved by use of a crystal of deuterated l-arginine phosphate. The crystal is cut and oriented so that the laser light propagates inside the crystal along one of several required directions, which correspond to a temperature-insensitive, phase-matching locus. The method of measuring and calculating the temperature-insensitive, phase-matching angles can be extended to other fundamental wavelengths and other crystal compositions. 12 figures.
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Characterization of Second Harmonic Afterburner Radiation at the LCLS
Nuhn, Heinz-Dieter
2010-09-14T23:59:59.000Z
During commissioning of the Linac Coherent Light Source (LCLS) x-ray Free Electron Laser (FEL) at the SLAC National Accelerator Laboratory it was shown that saturation lengths much shorter than the installed length of the undulator line can routinely be achieved. This frees undulator segments that can be used to provide enhanced spectral properties and at the same time, test the concept of FEL Afterburners. In December 2009 a project was initiated to convert undulator segments at the down-beam end of the undulator line into Second Harmonic Afterburners (SHAB) to enhance LCLS radiation levels in the 10-20 keV energy range. This is being accomplished by replacement of gap-shims increasing the fixed gaps from 6.8 mm to 9.9 mm, which reduces their K values from 3.50 to 2.25 and makes the segments resonant at the second harmonic of the upstream unmodified undulators. This paper reports experimental results of the commissioning of the SHAB extension to LCLS.
Our distorted view of magnetars: application of the Resonant Cyclotron Scattering model
N. Rea; S. Zane; M. Lyutikov; R. Turolla
2006-08-30T23:59:59.000Z
The X-ray spectra of the magnetar candidates are customarily fitted with an empirical, two component model: an absorbed blackbody and a power-law. However, the physical interpretation of these two spectral components is rarely discussed. It has been recently proposed that the presence of a hot plasma in the magnetosphere of highly magnetized neutron stars might distort, through efficient resonant cyclotron scattering, the thermal emission from the neutron star surface, resulting in the production of non-thermal spectra. Here we discuss the Resonant Cyclotron Scattering (RCS) model, and present its XSPEC implementation, as well as preliminary results of its application to Anomalous X-ray Pulsars and Soft Gamma-ray Repeaters.
Surface alloys of icosahedral AlMnSi with phason distortions
Follstaedt, D.M.; Knapp, J.A.
1986-12-01T23:59:59.000Z
The microstructures produced by electron-beam melting and by ion-beam mixing Al/Mn and Al/Mn/Si layers on Si substrates are examined. The treatments were found to incorporate Si from the substrate into the surface alloy. Several phases formed, depending on treatment, including ..cap alpha..- and ..beta..-AlMnSi, ..mu..-AlMn (epitaxial on Si(111), and amorphous and icosahedral AlMnSi. The observed microstructures relate the novel icosahedral phase to other phases and elucidate its formation kinetics. Diffraction patterns from large icosahedral grains (up to 5 ..mu..m) show distortions in the position and shape of weak (but not strong) reflections, as predicted for phason defects in a quasicrystalline lattice, one of the structures proposed for icosahedral phases.
Charge-induced distortion and stabilization of surface transfer doped porphyrin films
Smets, Y.; Stark, C. B.; Wright, C. A.; Pakes, C. I. [Department of Physics, La Trobe University, Bundoora, Victoria 3086 (Australia)] [Department of Physics, La Trobe University, Bundoora, Victoria 3086 (Australia); Lach, S.; Schmitt, F.; Ziegler, C. [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern (Germany)] [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, 67663 Kaiserslautern (Germany); Wanke, M. [Institut für Physik, Technische Universität Chemnitz, 09126 Chemnitz (Germany)] [Institut für Physik, Technische Universität Chemnitz, 09126 Chemnitz (Germany); Ley, L. [Department of Physics, La Trobe University, Bundoora, Victoria 3086 (Australia) [Department of Physics, La Trobe University, Bundoora, Victoria 3086 (Australia); Institut für Technische Physik, Universität Erlangen-Nürnberg, 91058 Erlangen (Germany)
2013-07-28T23:59:59.000Z
The interaction between zinc-tetraphenylporphyrin (ZnTPP) and fullerenes (C{sub 60} and C{sub 60}F{sub 48}) are studied using ultraviolet photoelectron spectroscopy (UPS) and scanning tunneling microscopy (STM). Low temperature STM reveals highly ordered ZnTPP monolayers on Au(111). In contrast to C{sub 60}, a submonolayer coverage of C{sub 60}F{sub 48} results in long-range disorder of the underlying single ZnTPP layer and distortion of individual ZnTPP molecules. This is induced by substantial charge transfer at the organic-organic interface, revealed by the interface energetics from UPS. However, a second layer of ZnTPP prevents C{sub 60}F{sub 48} guests from breaking the self-assembled porphyrin template. This finding is important for understanding the growth behaviour of “bottom-up” functional nanostructures involving strong donor-acceptor heterojunctions in molecular electronics.
Detecting and interpreting distortions in hierarchical organization of complex time series
Dro?d?, Stanis?aw
2015-01-01T23:59:59.000Z
Hierarchical organization is a cornerstone of complexity and multifractality constitutes its central quantifying concept. For model uniform cascades the corresponding singularity spectra are symmetric while those extracted from empirical data are often asymmetric. Using the selected time series representing such diverse phenomena like price changes and inter-transaction times in the financial markets, sentence length variability in the narrative texts, Missouri River discharge and Sunspot Number variability as examples, we show that the resulting singularity spectra appear strongly asymmetric, more often left-sided but in some cases also right-sided. We present a unified view on the origin of such effects and indicate that they may be crucially informative for identifying composition of the time series. One particularly intriguing case of this later kind of asymmetry is detected in the daily reported Sunspot Number variability. This signals that either the commonly used famous Wolf formula distorts the real d...
Peierls distorted chain as a quantum data bus for quantum state transfer
M. X. Huo; Ying Li; Z. Song; C. P. Sun
2006-06-01T23:59:59.000Z
We systematically study the transfer of quantum state of electron spin as the flying qubit along a half-filled Peierls distorted tight-binding chain described by the Su-Schrieffer-Heeger (SSH) model, which behaves as a quantum data bus. This enables a novel physical mechanism for quantum communication with always-on interaction: the effective hopping of the spin carrier between sites $A$ and $B$ connected to two sites in this SSH chain can be induced by the quasi-excitations of the SSH model. As we prove, it is the Peierls energy gap of the SSH quasi-excitations that plays a crucial role to protect the robustness of the quantum state transfer process. Moreover, our observation also indicates that such a scheme can also be employed to explore the intrinsic property of the quantum system.
Increased surface plasmon resonance sensitivity with the use of double Fourier harmonic gratings
Boyer, Edmond
Increased surface plasmon resonance sensitivity with the use of double Fourier harmonic gratings in the formalism of poles and zeros of the scattering matrix. Surface plasmon resonance is used to increase that a direct coupling between counter propagating surface plasmons using double-harmonic Fourier gratings leads
Santolik, Ondrej
Power line harmonic radiation observed by satellite: Properties and propagation through of power line harmonic radiation events observed by the low-altitude DEMETER spacecraft. Altogether, 88 with the largest intensities often occur off exact multiples of base power system frequency. This can be explained
High-order harmonic transient grating spectroscopy of SF6 molecular vibrations Amelie Ferre1
Paris-Sud XI, Université de
High-order harmonic transient grating spectroscopy of SF6 molecular vibrations Am´elie Ferr´e1. Here we use this technique to investigate the high-order harmonic genera- tion from SF6 molecules emission generated between 14 to 26 eV is mainly sensitive to two among the three active Raman modes in SF6
Hydrogen Generation from Water Disassociation Using Small Currents and Harmonics Trien N. Nguyen1
Zhou, Yaoqi
Hydrogen Generation from Water Disassociation Using Small Currents and Harmonics Trien N. Nguyen1 1 Department of Physics, Purdue School of Science Hydrogen can be produced cheaply and efficiently from water sources using a combination of harmonics and small currents. Hydrogen is a clean and virtually
A Multipole Based Treecode Using Spherical Harmonics for Potentials of the Form r-
Sarin, Vivek
A Multipole Based Treecode Using Spherical Harmonics for Potentials of the Form r- Kasthuri spherical harmonics to compute multipole coefficients that are used to evaluate these potentials. The key of the multipole expansion theorem used in the classical fast multipole algorithm [2]. This theorem is used
Silberberg, Yaron
Polarization gating of high-order harmonic generation takes advantage of the significant reduction of har for generation of polarization gated pulses using wave-plate combinations is inefficient, and propose photon energy radiation from the harmonic spectrum. Need- less to say, the generation of near single
Edge ion heating by launched high harmonic fast waves in the National Spherical Torus Experiment
Biewer, Theodore
Edge ion heating by launched high harmonic fast waves in the National Spherical Torus Experiment T al., Fusion Technology 30, 1337 (1996)] measures the velocity distribution of ions in the plasma edge power High Harmonic Fast Wave (HHFW) rf heating in helium plasmas, with the poloidal ion temperature
Injection of harmonics generated in gas in a free-electron laser providing intense and
Loss, Daniel
LETTERS Injection of harmonics generated in gas in a free-electron laser providing intense lasers promise to extend this down to femtosecond timescales. The process by which free-electron lasers of the free-electron laser saturation length, and the generation of nonlinear harmonics13 at 54 nm and 32 nm
Two-beam high-order harmonics from solids: Coupling mechanisms
Tarasevitch, A.; Wieczorek, J.; Kohn, R.; Bovensiepen, U.; Linde, D. von der [Fakultaet fuer Physik, Universitaet Duisburg-Essen, Lotharstr. 1, 47048 Duisburg (Germany)
2010-11-15T23:59:59.000Z
The polarization of the two beam (driver-probe) high-order harmonic generation from solids is measured. The experiments, together with computer simulations, allow us to distinguish two different coupling mechanisms of the driver and the probe, resulting in different harmonic efficiencies and spectral slopes. We find that in the nonrelativistic regime the coupling is mostly due to the nonlinear plasma density modulation.
High-order harmonic generation in the presence of a static electric field
Odzak, S. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D.B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)
2005-09-15T23:59:59.000Z
We consider high-order harmonic generation by a linearly polarized laser field and a parallel static electric field. We first develop a modified saddle-point method which enables a quantitative analysis of the harmonic spectra even in the presence of Coulomb singularities. We introduce a classification of the saddle-point solutions and show that, in the presence of a static electric field which breaks the inversion symmetry, an additional classification number has to be introduced and that the usual saddle-point approximation and the uniform approximation in the case of the coalescing saddle points have to be modified. The theory developed offers a simple and accurate explanation of the static-field-induced multiplateau structure of the harmonic spectra. The longer quantum orbits are responsible for a long extension of the harmonic plateau, while the larger initial electron velocities are the reason of lower harmonic emission rates.
Relativistic second harmonic generation from an S-polarized laser in over-dense plasma
Adusumilli, K.; Goyal, D.; Tripathi, V. K. [Department of Physics, Indian Institute of Technology-Delhi, Delhi, New Delhi 110016 (India)
2011-08-15T23:59:59.000Z
A relativistic S-polarized short pulse laser impinged obliquely on an overdense plasma thin foil is shown to produce very significant second harmonic in the direction of specular reflection. The second harmonic is P-polarized and is driven by the second harmonic ponderomotive force on electrons in the skin layer. The treatment incorporates the electron density modification by the static ponderomotive force and mass modification due to relativistic effects. The second harmonic reflected amplitude is greatest for an optimum value of the angle of incidence. The conversion efficiency of the second harmonic is greater for higher values of incident laser amplitude and lower values of electron density in the foil. The equivalence between the total ponderomotive force and the radiation pressure force is also demonstrated.
Performance study of a soft X-ray harmonic generation FEL seeded with an EUV laser pulse
Gullans, M.; Wurtele, J.S.; Penn, G.; Zholents, A.A.
2007-01-01T23:59:59.000Z
X-ray Harmonic Generation FEL Seeded with an EUV Laser PulseX-ray harmonic generation FEL seeded with an EUV laser pulseof a free electron laser (FEL) using a low-power extreme
Polarization-Modulated Second Harmonic Generation Microscopy in Collagen
Stoller, P C
2002-09-30T23:59:59.000Z
Collagen is a key structural protein in the body; several pathological conditions lead to changes in collagen. Among imaging modalities that can be used in vivo, second harmonic generation (SHG) microscopy has a key advantage: it provides {approx}1 {micro}m resolution information about collagen structure as a function of depth. A new technique--polarization-modulated SHG--is presented: it permits simultaneous measurement of collagen orientation, of a lower bound on the magnitude of the second order nonlinear susceptibility tensor, and of the ratio of the two independent elements in this tensor. It is applied to characterizing SHG in collagen and to determining effects of biologically relevant changes in collagen structure. The magnitude of the second harmonic signal in two dimensional images varies with position even in structurally homogeneous tissue; this phenomenon is due to interference between second harmonic light generated by neighboring fibrils, which are randomly oriented parallel or anti-parallel to each other. Studies in which focal spot size was varied indicated that regions where fibrils are co-oriented are less than {approx}1.5 {micro}m in diameter. A quartz reference was used to determine the spot size as well as a lower limit (d{sub xxx} > 0.3 pm/V) for the magnitude of the second order nonlinear susceptibility. The ratio of the two independent tensor elements ranged between d{sub XYY}/d{sub XXX} = 0.60 and 0.75. SHG magnitude alone was not useful for identifying structural anomalies in collagenous tissue. Instead, changes in the polarization dependence of SHG were used to analyze biologically relevant perturbations in collagen structure. Changes in polarization dependence were observed in dehydrated samples, but not in highly crosslinked samples, despite significant alterations in packing structure. Complete thermal denaturation and collagenase digestion produced samples with no detectable SHG signal. Collagen orientation was measured in thin samples of several different tissues in transmission mode as well as at different depths (up to 200 {micro}m) in thick samples in reflection mode; birefringence had no effect on the measurement. These studies showed that SHG microscopy was capable of detecting pathophysiological changes in collagen structure, suggesting that this technique has potential clinical applications.
An Ning; Ren Huaijin [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); State Key Laboratory on Fiber Optic Local Area Communication Networks and Advanced Optical Communication Systems, Shanghai 200240 (China); Zheng Yuanlin [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Key Laboratory for Laser Plasmas (Ministry of Education), Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Deng Xuewei [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Chen Xianfeng [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); State Key Laboratory on Fiber Optic Local Area Communication Networks and Advanced Optical Communication Systems, Shanghai 200240 (China); Key Laboratory for Laser Plasmas (Ministry of Education), Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)
2012-05-28T23:59:59.000Z
We propose a scheme for efficient Cherenkov high-order harmonic generation. Second to fifth order harmonic wave are observed in a single periodically poled ferroelectric crystal in our experiment. The noncollinear high-order harmonic generation is produced via enhanced Cherenkov second harmonic cascaded with successive multistep sum-frequency generation with simultaneously longitudinal phase-matching. The emission angle and power dependencies are analyzed in detail experimentally, which coincide with theoretical predictions.
Thermal transport in out of equilibrium quantum harmonic chains
F. Nicacio; A. Ferraro; A. Imparato; M. Paternostro; F. L. Semião
2015-04-15T23:59:59.000Z
We address the problem of heat transport in a chain of coupled quantum harmonic oscillators, exposed to the influences of local environments of various nature, stressing the effects that the specific nature of the environment has on the phenomenology of the transport process. We study in detail the behavior of thermodynamically relevant quantities such as heat currents and mean energies of the oscillators, establishing rigorous analytical conditions for the existence of a steady state, whose features we analyse carefully. In particular we assess the conditions that should be faced to recover trends reminiscent of the classical Fourier law of heat conduction and highlight how such a possibility depends on the environment linked to our system.
Multipole expansions in four-dimensional hyperspherical harmonics
A. V. Meremianin
2006-06-27T23:59:59.000Z
The technique of vector differentiation is applied to the problem of the derivation of multipole expansions in four-dimensional space. Explicit expressions for the multipole expansion of the function $r^n C_j (\\hr)$ with $\\vvr=\\vvr_1+\\vvr_2$ are given in terms of tensor products of two hyperspherical harmonics depending on the unit vectors $\\hr_1$ and $\\hr_2$. The multipole decomposition of the function $(\\vvr_1 \\cdot \\vvr_2)^n$ is also derived. The proposed method can be easily generalised to the case of the space with dimensionality larger than four. Several explicit expressions for the four-dimensional Clebsch-Gordan coefficients with particular values of parameters are presented in the closed form.
Improved gauge driver for the generalized harmonic Einstein system
Lindblom, Lee; Szilagyi, Bela [Theoretical Astrophysics 350-17, California Institute of Technology, Pasadena, California 91125 (United States)
2009-10-15T23:59:59.000Z
A new gauge driver is introduced for the generalized harmonic (GH) representation of Einstein's equation. This new driver allows a rather general class of gauge conditions to be implemented in a way that maintains the hyperbolicity of the combined evolution system. This driver is more stable and effective and, unlike previous drivers, allows stable evolutions using the dual-frame evolution technique. Appropriate boundary conditions for this new gauge driver are constructed, and a new boundary condition for the 'gauge' components of the spacetime metric in the GH Einstein system is introduced. The stability and effectiveness of this new gauge driver are demonstrated through numerical tests, which impose a new damped-wave gauge condition on the evolutions of single black-hole spacetimes.
High performance control of harmonic instability from HVDC link system
Min, W.K.; Yoo, M.H. [Korea Electric Power Research Inst., Taejeon (Korea, Republic of)
1995-12-31T23:59:59.000Z
This paper investigates the usefulness of novel control method for HVDC link system which suffers from severe condition of low order harmonic. This control scheme is used the feedforward control method which is directly controlled dc current at dc link system. The studies of this paper are aimed to improving the dynamic response of HVdc link system in disturbances such as faults. To achieve those objectives, digital time domain simulations are employed by the electro magnetic transient program for dc system (EMTDC). This method results in stable recovery from faults at both rectifier and inverter terminal busbars for a HVdc system that is inherently unstable. It has been found to be robust and control performance has been enhanced.
Theory of Second-Harmonic Generation in Colloidal Crystals J. P. Huang,* Y. C. Jian, and C. Z. Fan
Huang, Ji-Ping
Theory of Second-Harmonic Generation in Colloidal Crystals J. P. Huang,* Y. C. Jian, and C. Z. Fan-Kornfeld formulation, we study the effective susceptibility of second-harmonic generation (SHG) in colloidal crystals of second-harmonic generation (SHG); that is, an input (pump) wave can generate another wave with twice
Boschi, Lapo
Can the Earth's harmonic spectrum be derived directly from1 the stochastic inversion of global globe, to a statistical measure of the Earth's complexity: its spherical-harmonic spectrum.18 We follow averaged variance and harmonic spectrum; one can then determine the20 latter from a measurement
HARMONIC FUNCTIONS FOR SEA-SURFACE TEMPERATURES AND SALINITIES, KOKO HEAD, OAHU, 1956-69, AND SEA-SURFACE TEMPERATURES, CHRISTMAS ISLAND, 1954-69 GUNTHER It SECKEL' AND MARIAN Y. Y. YONG' ABSTRACT Harmonic functions, with daily sampling, are on average 0.07Â° C. Harmonic analysis spanning the entire sampling duration shows
Texas at Austin. University of
Harmonic generation by reflecting internal waves Bruce Rodenborn, D. Kiefer, H. P. Zhang, and Harry harmonics and mixing. We use laboratory experiments and two-dimensional numerical simulations of the Navier harmonic waves in the reflection process. The results from our experiments and simulations agree well
Chu, Shih-I
ionization and high-order-harmonic generation driven by intense frequency-comb laser fields: An ab initio investigation of the coherent control and significant enhancement of multiphoton ionization (MPI) and high-order-harmonic and molecular dynamics [28Â30], and the generation of soft-x-ray attosecond pulses by high-order-harmonic
RF physics of ICWC discharge at high cyclotron harmonics
Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M. [Association Euratom-Belgian State, LPP-ERM-KMS, 1000 Brussels (Belgium); Bobkov, V.; Rohde, V.; Schneider, P. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Douai, D.; Kogut, D. [Association Euratom-CEA, CEA, IRFM, 13108 St Paul lez Durance (France); Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G. [Association Euratom-IEK-4, Forschungszentrum Jülich, 52425 Jülich (Germany); Moiseenko, V. [Institute of Plasma Physics NSC KIPT, 61108 Kharkiv (Ukraine); Noterdaeme, J.-M. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching, Germany and Ghent University, 9000 Ghent (Belgium); Collaboration: TEXTOR Team; ASDEX Upgrade Team
2014-02-12T23:59:59.000Z
Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,?=?{sub H+}, and with its high cyclotron harmonics (HCH), ?=10?{sub cH+}? HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}?0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}?350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ?H} ?1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.
Compact Chopper-Stabilized Neural Amplifier with Low-Distortion High-Pass Filter in 0.13m CMOS
Genov, Roman
Compact Chopper-Stabilized Neural Amplifier with Low-Distortion High-Pass Filter in 0.13µm CMOS all channels requires a large number of low-noise neural recording front-end ampli- fiers. This drives recording amplifiers utilizing chopper stabilization to reduce flicker noise have been demonstrated
Klein, Stanley
METHODS Four combinations of two cosine gratings, the 2nd and 6th harmonics of a 0.5 c/deg grating harmonic in isolation, pattern 2 is the 6th harmonic in isolation, pattern 3 is the 2nd plus the 6th and pattern 4 is the 2nd minus the 6th. The one-dimensional noise was the sum of 1st-7th harmonics of a 0.5c
Theoretical analysis of high-order harmonic generation from a coherent superposition of states
Milosevic, Dejan B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, Berlin, 12489 (Germany)
2006-02-15T23:59:59.000Z
A quantum theory of high-order harmonic generation by a strong laser field in the presence of more bound states is formulated. The obtained numerical and analytical results for a two-state hydrogenlike atom model show that the harmonic spectrum consists of two parts: a usual single-state harmonic spectrum of odd harmonics having the energies (2k+1){omega} and a resonant part with the peaks around the excitation energy {delta}{omega}. The energy of the harmonics in the resonant part of the spectrum is equal to {delta}{omega}{+-}{omega}, {delta}{omega}{+-}3{omega}, .... For energies higher than the excitation energy, the resonant part forms a plateau, followed by a cutoff. The emission rate of the harmonics in this resonant plateau is many orders of magnitude higher than that of the harmonics generated in the presence of the ground state alone. The influence of the depletion of the initial states, as well as of the pulse shape and intensity, is analyzed.
Resonant third-harmonic generation of a short-pulse laser from electron-hole plasmas
Kant, Niti [Department of Physics, Lovely Professional University, Phagwara, Punjab 144 402 (India); Nandan Gupta, Devki [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Suk, Hyyong [Advanced Photonics Research Institute (APRI) and Graduate Program of Photonics and Applied Physics, Gwangju Institute of Science and Technology, Gwangju 500 712 (Korea, Republic of)
2012-01-15T23:59:59.000Z
In semiconductors, free carriers are created in pairs in inter-band transitions and consist of an electron and its corresponding hole. At very high carrier densities, carrier-carrier collisions dominate over carrier-lattice collisions and carriers begin to behave collectively to form plasma. Here, we apply a short-pulse laser to generate third-harmonic radiation from a semiconductor plasma (electron-hole plasma) in the presence of a transverse wiggler magnetic-field. The process of third-harmonic generation of an intense short-pulse laser is resonantly enhanced by the magnetic wiggler, i.e., wiggler magnetic field provides the necessary momentum to third-harmonic photons. In addition, a high-power laser radiation, propagating through a semiconductor imparts an oscillatory velocity to the electrons and exerts a ponderomotive force on electrons at the third-harmonic frequency of the laser. This oscillatory velocity produces a third-harmonic longitudinal current. And due to the beating of the longitudinal electron velocity and the wiggler magnetic field, a transverse third-harmonic current is produced that drives third-harmonic electromagnetic radiation. It is finally observed that for a specific wiggler wave number value, the phase-matching conditions for the process are satisfied, leading to resonant enhancement in the energy conversion efficiency.
Analysis of higher harmonic contamination with a modified approach using a grating analyser
Gupta, Rajkumar, E-mail: rkg@rract.gov.in; Modi, Mohammed H.; Lodha, G. S. [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)] [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Kumar, M.; Chakera, J. A. [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)] [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)
2014-04-15T23:59:59.000Z
Soft x-ray spectra of the toroidal grating monochromator (TGM) at the reflectivity beamline of Indus-1 synchrotron source are analyzed for higher harmonic contribution. A diffraction grating of central line spacing 1200 l/mm is used to disperse the monochromatic beam received from TGM to quantify the harmonic contents in the 50–360 Å wavelength range. In order to calculate the harmonic contamination, conventionally the intensity of higher order peak is divided by first order peak intensity of the desired wavelength. This approach is found to give wrong estimate as first order peak itself is overlapped by higher order peaks. In the present study, a modified approach has been proposed to calculate harmonic contamination where the intensity contributions of overlapping orders have been removed from the first order diffraction peak of the desired wavelength. It is found that the order contamination in the TGM spectra is less than 15% in the wavelength range of 90–180 Å. The total harmonic contribution increases from 6%–60% in the wavelength range of 150–260 Å. The critical wavelength of Indus-1 is 61 Å hence the harmonic contamination below 90 Å is significantly low. The results obtained with modified approach match well with those obtained by quantitative analysis of multilayer reflectivity data. The obtained higher harmonics data are used to fit the transmission of aluminum edge filter in the 120–360 Å wavelength range.
Boyarinov, V. F.; Kondrushin, A. E.; Fomichenko, P. A. [National Research Center, Kurchatov Inst., Kurchatov Sq. 1, Moscow (Russian Federation)
2012-07-01T23:59:59.000Z
Finite-difference time-dependent equations of Surface Harmonics method have been obtained for plane geometry. Verification of these equations has been carried out by calculations of tasks from 'Benchmark Problem Book ANL-7416'. The capacity and efficiency of the Surface Harmonics method have been demonstrated by solution of the time-dependent neutron transport equation in diffusion approximation. The results of studies showed that implementation of Surface Harmonics method for full-scale calculations will lead to a significant progress in the efficient solution of the time-dependent neutron transport problems in nuclear reactors. (authors)
Harmonics suppression effect of the quasi-periodic undulator in SASE free-electron-laser
Ai-Lin Wu; Qi-Ka Jia; He-Ting Li
2013-05-03T23:59:59.000Z
In this paper, the harmonics suppression effect of QPUs in SASE FEL is investigated. The numerical results show that the harmonics power is reduced by using QPUs, but the fundamental radiation power also has a pronounced decrease as the saturation length gets very long. The cases of employing QPUs as parts of undulators are studied. The calculations show that if the fraction of QPUs and their offgap are appropriate in an undulator system, the harmonics radiation could be suppressed remarkably, meanwhile the fundamental saturation length does not increase too much.
Analysis of second harmonic instability for the Chateauguay HVDC/SVC scheme
Hammad, A.E. (ABB Power Systems, 5401-Baden (CH))
1992-01-01T23:59:59.000Z
The Chateauguay HVDC back-to-back scheme with interconnections to the 765 kV transmission to U.S.A. and to Beauharnois generators can exhibit, under certain operating conditions, second harmonic resonance problems. This paper presents a thorough analysis of the problem using an eigenvalue and frequency domain approach. The analysis explains the mechanism of exciting the second harmonic instability by the presence of HVDC converters. The influence of changing the control parameters of the static VAR compensatory at the Chateauguay terminal is also studied. Finally, an assessment is made for the effectiveness of present countermeasure schemes, namely; the auxiliary dc stabilizing controls and the installation of second harmonic filters.
On compactified harmonic/projective superspace, 5D superconformal theories, and all that
Sergei M. Kuzenko
2007-07-16T23:59:59.000Z
Within the supertwistor approach, we analyse the superconformal structure of 4D N = 2 compactified harmonic/projective superspace. In the case of 5D superconformal symmetry, we derive the superconformal Killing vectors and related building blocks which emerge in the transformation laws of primary superfields. Various off-shell superconformal multiplets are presented both in 5D harmonic and projective superspaces, including the so-called tropical (vector) multiplet and polar (hyper)multiplet. Families of superconformal actions are described both in the 5D harmonic and projective superspace settings. We also present examples of 5D superconformal theories with gauged central charge.
Raman shifted third harmonic generation of upper hybrid radiation in a plasma
Magesh Kumar, K.K.; Singh, Ranjeet; Tripathi, V. K. [Department of Physics, Indian Institute of Technology Delhi, New Delhi-110016 (India)
2012-11-15T23:59:59.000Z
Raman shifted third harmonic generation of upper hybrid radiation is proposed and studied. In the presence of ambient magnetic field, the plasma wave present in the system produces electron density ripple (perturbation) which couples with the velocity imparted by the nonlinear ponderomotive force at twice the laser frequency producing the Raman shifted third harmonic field. The wave vector of the plasma wave provides the uncompensated momentum necessary for phase matching condition. The applied magnetic field can be adjusted to have the phase matching for the given plasma frequency. The energy conversion ratio from pump to the Raman shifted third harmonic generation of upper hybrid radiation is analyzed.
Third harmonic stimulated Raman backscattering of laser in a magnetized plasma
Paknezhad, Alireza [Physics Department, Shabestar Branch, Islamic Azad University, Shabestar (Iran, Islamic Republic of)] [Physics Department, Shabestar Branch, Islamic Azad University, Shabestar (Iran, Islamic Republic of); Dorranian, Davoud [Laser Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)] [Laser Lab., Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)
2013-09-15T23:59:59.000Z
This article studies the nonlinear Raman shifted third harmonic backscattering of an intense extraordinary laser wave through a homogenous transversely magnetized cold plasma. Due to the relativistic nonlinearity, the plasma dynamic is modified in the presence of transversely magnetic field, and this can generate the third harmonic scattered wave and an electrostatic upper hybrid wave via the Raman scattering process. Using the nonlinear wave equation, the mechanism of nonlinear third harmonic Raman scattering is discussed in detail to obtain the maximum growth rate of instability in the mildly relativistic regime. The growth rate decreases as the static magnetic field increases. It also increases with the pump wave amplitude.
Generation of high-power tunable terahertz-radiation by nonrelativistic beam-echo harmonic effect
Gong Huarong; Xu Jin; Wei Yanyu; Gong Yubin [National Key Laboratory of Science and Technology on Vacuum Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Travish, Gil [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Feng Jinjun [Vacuum Electronics National Laboratory, Vacuum Electronics research Institute, Beijing 100016 (China)
2013-01-15T23:59:59.000Z
A new type of terahertz radiation source based on the nonrelativistic electron beam-wave interaction is proposed. Here, the beam echo harmonic effect is applied to a traveling wave tube like device. The scheme is configured as a combination of a frequency multiplier and amplifier with, for instance, W-band (millimeter wave) input signals and terahertz output power. A one-dimensional model of this device shows that a 10th order harmonic-wave can be generated while other harmonic waves are suppressed. The device only requires a readily available input source (W-band), and the output frequency can be tuned continuously over a wide band.
Electro-optic harmonic conversion to switch a laser beam out of a cavity
Haas, Roger A. (Pleasanton, CA); Henesian, Mark A. (Livermore, CA)
1987-01-01T23:59:59.000Z
The invention is a switch to permit a laser beam to escape a laser cavity through the use of an externally applied electric field across a harmonic conversion crystal. Amplification takes place in the laser cavity, and then the laser beam is switched out by the laser light being harmonically converted with dichroic or polarization sensitive elements present to alter the optical path of the harmonically converted laser light. Modulation of the laser beam can also be accomplished by varying the external electric field.
Generalized Harmonic Oscillator and the Schrödinger Equation with Position-Dependent Mass
Ju Guo-Xing; Cai Chang-Ying; Ren Zhong-Zhou
2007-07-22T23:59:59.000Z
We study the generalized harmonic oscillator which has both the position-dependent mass and the potential depending on the form of mass function in a more general framework. The explicit expressions of the eigenvalue and eigenfunction for such system are given, they have the same forms as those for the usual harmonic oscillator with constant mass. The coherent state and the its properties for the system with PDM are also discussed. We give the corresponding effective potentials for several mass functions, the systems with such potentials are isospectral to the usual harmonic oscillator.
A CLASS OF ECCENTRIC BINARIES WITH DYNAMIC TIDAL DISTORTIONS DISCOVERED WITH KEPLER
Thompson, Susan E.; Barclay, Thomas; Howell, Steve B.; Still, Martin; Ibrahim, Khadeejah A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Everett, Mark [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Mullally, Fergal; Rowe, Jason; Christiansen, Jessie L.; Twicken, Joseph D.; Clarke, Bruce D. [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Kurtz, Donald W.; Hambleton, Kelly, E-mail: susan.e.thompson@nasa.gov [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom)
2012-07-01T23:59:59.000Z
We have discovered a class of eccentric binary systems within the Kepler data archive that have dynamic tidal distortions and tidally induced pulsations. Each has a uniquely shaped light curve that is characterized by periodic brightening or variability at timescales of 4-20 days, frequently accompanied by shorter period oscillations. We can explain the dominant features of the entire class with orbitally varying tidal forces that occur in close, eccentric binary systems. The large variety of light curve shapes arises from viewing systems at different angles. This hypothesis is supported by spectroscopic radial velocity measurements for five systems, each showing evidence of being in an eccentric binary system. Prior to the discovery of these 17 new systems, only four stars, where KOI-54 is the best example, were known to have evidence of these dynamic tides and tidally induced oscillations. We perform preliminary fits to the light curves and radial velocity data, present the overall properties of this class, and discuss the work required to accurately model these systems.
Ultra-lightweight telescope with MEMS adaptive optic for distortion correction.
Spahn, Olga Blum; Cowan, William D.; Shaw, Michael J.; Adams, David Price; Sweatt, William C.; Dagel, Daryl James; Grine, Alejandro J.; Mani, Seethambal S.; Resnick, Paul James; Gass, Fawn Renee; Grossetete, Grant David
2004-12-01T23:59:59.000Z
Recent world events have underscored the need for a satellite based persistent global surveillance capability. To be useful, the satellite must be able to continuously monitor objects the size of a person anywhere on the globe and do so at a low cost. One way to satisfy these requirements involves a constellation of satellites in low earth orbit capable of resolving a spot on the order of 20 cm. To reduce cost of deployment, such a system must be dramatically lighter than a traditional satellite surveillance system with a high spatial resolution. The key to meeting this requirement is a lightweight optics system with a deformable primary and secondary mirrors and an adaptive optic subsystem correction of wavefront distortion. This proposal is concerned with development of MEMS micromirrors for correction of aberrations in the primary mirror and improvement of image quality, thus reducing the optical requirements on the deployable mirrors. To meet this challenge, MEMS micromirrors must meet stringent criteria on their performance in terms of flatness, roughness and resolution of position. Using Sandia's SUMMIT foundry which provides the world's most sophisticated surface MEMS technology as well as novel designs optimized by finite element analysis will meet severe requirements on mirror travel range and accuracy.
Distortion of the luminosity function of high-redshift galaxies by gravitational lensing
Fialkov, Anastasia
2015-01-01T23:59:59.000Z
The observed properties of high redshift galaxies depend on the underlying foreground distribution of large scale structure, which distorts their intrinsic properties via gravitational lensing. We focus on the regime where the dominant contribution originates from a single lens and examine the statistics of gravitational lensing by a population of virialized and non-virialized structures using sub-mm galaxies at z ~ 2.6 and Lyman-break galaxies at redshifts z ~ 6-15 as the background sources. We quantify the effect of lensing on the luminosity function of the high redshift sources, focusing on the intermediate and small magnifications (mu < 3) which affect the majority of the background galaxies. We show that depending on the intrinsic properties of the background galaxies, gravitational lensing can significantly affect the observed luminosity function even when no obvious strong lenses are present. Finally, we find that in the case of the Lyman-break galaxies it is important to account for the surface bri...
Tocchini-Valentini, Domenico; Barnard, Michael; Bennett, Charles L.; Szalay, Alexander S., E-mail: dtv@pha.jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States)
2012-10-01T23:59:59.000Z
We present a method to extract the redshift-space distortion {beta} parameter in configuration space with a minimal set of cosmological assumptions. We show that a novel combination of the observed monopole and quadrupole correlation functions can remove efficiently the impact of mild nonlinearities and redshift errors. The method offers a series of convenient properties: it does not depend on the theoretical linear correlation function, the mean galaxy density is irrelevant, only convolutions are used, and there is no explicit dependence on linear bias. Analyses based on dark matter N-body simulations and Fisher matrix demonstrate that errors of a few percent on {beta} are possible with a full-sky, 1 (h {sup -1} Gpc){sup 3} survey centered at a redshift of unity and with negligible shot noise. We also find a baryonic feature in the normalized quadrupole in configuration space that should complicate the extraction of the growth parameter from the linear theory asymptote, but that does not have a major impact on our method.
R. G. Beausoleil; E. D'Ambrosio; W. Kells; J. Camp; E K. Gustafson; M. M. Fejer
2002-05-29T23:59:59.000Z
We develop a steady-state analytical and numerical model of the optical response of power-recycled Fabry-Perot Michelson laser gravitational-wave detectors to thermal focusing in optical substrates. We assume that the thermal distortions are small enough that we can represent the unperturbed intracavity field anywhere in the detector as a linear combination of basis functions related to the eigenmodes of one of the Fabry-Perot arm cavities, and we take great care to preserve numerically the nearly ideal longitudinal phase resonance conditions that would otherwise be provided by an external servo-locking control system. We have included the effects of nonlinear thermal focusing due to power absorption in both the substrates and coatings of the mirrors and beamsplitter, the effects of a finite mismatch between the curvatures of the laser wavefront and the mirror surface, and the diffraction by the mirror aperture at each instance of reflection and transmission. We demonstrate a detailed numerical example of this model using the MATLAB program Melody for the initial LIGO detector in the Hermite-Gauss basis, and compare the resulting computations of intracavity fields in two special cases with those of a fast Fourier transform field propagation model. Additional systematic perturbations (e.g., mirror tilt, thermoelastic surface deformations, and other optical imperfections) can be included easily by incorporating the appropriate operators into the transfer matrices describing reflection and transmission for the mirrors and beamsplitter.
Kim, Eun-ah [Department of Chemistry Education, Chung-Ang University, Seoul 156-756 (Korea, Republic of)] [Department of Chemistry Education, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Lee, Dong Woo [Department of Chemistry, Chung-Ang University, Seoul 156-756 (Korea, Republic of)] [Department of Chemistry, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Ok, Kang Min, E-mail: kmok@cau.ac.kr [Department of Chemistry, Chung-Ang University, Seoul 156-756 (Korea, Republic of)
2012-11-15T23:59:59.000Z
The syntheses, structures, and characterization of organically templated zero-dimensional titanium fluoride materials, A{sub 2}TiF{sub 6} (A=[N(CH{sub 3}){sub 4}] or [C(NH{sub 2}){sub 3}]), are reported. Phase pure samples of A{sub 2}TiF{sub 6} were synthesized by either solvothermal reaction method or a simple mixing method. While [N(CH{sub 3}){sub 4}]{sub 2}TiF{sub 6} crystallizes in a centrosymmetric space group, R-3, [C(NH{sub 2}){sub 3}]{sub 2}TiF{sub 6} crystallizes in a noncentrosymmetric polar space group, Cm. The asymmetric out-of-center distortion of TiF{sub 6} octahedra in polar [C(NH{sub 2}){sub 3}]{sub 2}TiF{sub 6} are attributable to the hydrogen-bonding interactions between the fluorine atoms in TiF{sub 6} octahedra and the nitrogen atoms in the [C(NH{sub 2}){sub 3}]{sup +} cation. Powder second-harmonic generation (SHG) measurements on the [C(NH{sub 2}){sub 3}]{sub 2}TiF{sub 6}, using 1064 nm radiation, indicate the material has SHG efficiency of 25 Multiplication-Sign that of {alpha}-SiO{sub 2}, which indicates an average nonlinear optical susceptibility, Left-Pointing-Angle-Bracket d{sub eff} Right-Pointing-Angle-Bracket {sub exp} of 2.8 pm/V. Additional SHG measurements reveal that the material is not phase-matchable (Type 1). The magnitudes of out-of-center distortions and dipole moment calculations for TiF{sub 6} octahedra will be also reported. - Graphical abstract: The out-of-center distortion of TiF{sub 6} octahedron in the polar noncentrosymmetric [C(NH{sub 2}){sub 3}]{sub 2}TiF{sub 6} is attributable to the hydrogen-bonding interactions between the F in TiF{sub 6} octahedron and the H-N in the [C(NH{sub 2}){sub 3}]{sup +}. Highlights: Black-Right-Pointing-Pointer Two titanium fluorides materials have been synthesized in high yields. Black-Right-Pointing-Pointer Hydrogen-bonds are crucial for the out-of-center distortion of TiF{sub 6} octahedra. Black-Right-Pointing-Pointer [C(NH{sub 2}){sub 3}]{sub 2}TiF{sub 6} has a SHG efficiency of 25 Multiplication-Sign that of {alpha}-SiO{sub 2}.
An explanation for experimental observations of harmonic cyclotron emission induced by fast ions
Chen, K.R.; Horton, W.; Van Dam, J.W.
1993-09-01T23:59:59.000Z
An explanation, supported by numerical simulations and analytical theory, is given for the harmonic cyclotron emission induced by fast ions in tokamak plasmas - particular, for the emission observed at low harmonics in deuterium-deuterium md deuterium-tritium experiments in the Joint European Tokamak. We show that the first proton harmonic is one of the highest spectral peaks whereas the first alpha is weak. We also compare the relative spectral amplitudes of different harmonics. Our results axe consistent with the experimental observations. The simulations verify that the instabilities are caused by a weak relativistic mass effect. Simulation that a nonuniform magnetic field leads to no appreciable change in the growth and saturation amplitude of the waves.
Pearson, Jeremy T
2013-05-06T23:59:59.000Z
I propose and demonstrate a method by which barium titanate nanoparticle clusters can be used as exogenous contrast agents in Second Harmonic Optical Coherence Tomography imaging systems to localize and highlight desired regions of tissue. SH...
A continuous-wave second harmonic gyrotron oscillator at 460 GHz
Hornstein, Melissa K. (Melissa Kristen), 1977-
2005-01-01T23:59:59.000Z
We report the short pulse and CW operation of a 460 GHz gyrotron oscillator both at the fundamental (near 230 GHz) and second harmonic (near 460 GHz) of electron cyclotron resonance. During operation in a complete CW regime ...
Generation of octave-spanning multiple harmonics for ultrafast waveform synthesis
Hsu, Wei-Chun
Up to seven laser harmonics covering more than two octaves in frequency have been generated efficiently in a single PPLT crystal, permitting the synthesis of 1.5 femtosecond pulses in a stable and compact setting.
Heath, G.
2012-06-01T23:59:59.000Z
This powerpoint presentation to be presented at the World Renewable Energy Forum on May 14, 2012, in Denver, CO, discusses systematic review and harmonization of life cycle GHG emission estimates for electricity generation technologies.
High-Gain Harmonic Generation Free-Electron Laser at Saturation
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Gain Harmonic Generation Free-Electron Laser at Saturation T. Shaftan 1 , M. Babzien 1 , I. Ben-Zvi 1 , S. G. Biedron 2 , L. F. DiMauro 1 , A. Doyuran 1 , J.N. Galayda 2 , E....
Bulk viscosity-driven suppression of shear viscosity effects on the flow harmonics at RHIC
J. Noronha-Hostler; J. Noronha; F. Grassi
2014-06-19T23:59:59.000Z
The interplay between shear and bulk viscosities on the flow harmonics, $v_n$'s, at RHIC is investigated using the newly developed relativistic 2+1 hydrodynamical code v-USPhydro that includes bulk and shear viscosity effects both in the hydrodynamic evolution and also at freeze-out. While shear viscosity is known to attenuate the flow harmonics, we find that the inclusion of bulk viscosity decreases the shear viscosity-induced suppression of the flow harmonics bringing them closer to their values in ideal hydrodynamical calculations. Depending on the value of the bulk viscosity to entropy density ratio, $\\zeta/s$, in the quark-gluon plasma, the bulk viscosity-driven suppression of shear viscosity effects on the flow harmonics may require a re-evaluation of the previous estimates of the shear viscosity to entropy density ratio, $\\eta/s$, of the quark-gluon plasma previously extracted by comparing hydrodynamic calculations to heavy ion data.
Pitch perception and harmonic resolvability in normal-hearing and hearing-impaired listeners
Bernstein, Joshua G. W
2006-01-01T23:59:59.000Z
Listeners with sensorineural hearing loss are often impaired in their ability to perceive the pitch associated with the fundamental frequency (FO) of complex harmonic sounds. Four studies investigated the relationship ...
NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES
Bartels, Soeren
NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES Geometric partial differential equations and their analysis as well as numerical simulation have recently
Oscillator Seeding of a High Gain Harmonic Generation FEL in a Radiator-First Configuration
Gandhi, P.
2014-01-01T23:59:59.000Z
Proceedings of the 2010 FEL Conference, Malm¨o, Sweden,Proceedings of the 2010 FEL Conference, Malm¨o, Sweden,of a high gain harmonic generation FEL in a radiator-first
Williams, S.M. (Naval Postgraduate School, Monterey, CA (United States)); Brownfield, G.T. (Union Electric Co., St. Louis, MO (United States)); Duffus, J.W. (Univ. of Missouri, Columbia, MO (United States). Power Electronics Research Center)
1993-04-01T23:59:59.000Z
Power electronic loads are occupying an increasing fraction of the total load on distribution feeders. Coincidentally, there is a greater use of power factor correction capacitors on the distribution system. These two factors can present poor operating conditions in the form of high harmonic levels propagating through a distribution system. Electric utility engineers are facing an ever increasing number of situations which require the analysis of the propagation of harmonics on a distribution system. HARMFLO was developed by EPRI for use in the analysis of harmonics on a power system. However, for a typical analysis of a distribution system, data for some of the parameters required by HARMFLO are not available. Furthermore, exact load information is usually not available. Harmonic levels determined from field tests on a distribution system are compared to results of HARMFLO simulations to determine if this analysis tool can be expected to provide useful results despite the lack of exact information for load modeling and other system parameters.
Pearson, Jeremy T
2013-05-06T23:59:59.000Z
generating nanoparticle clusters exhibit high scattering properties, which can give them the advantage of backscattering a large quantity of second harmonic light while attenuating the forward scattered light. In this research project, a mathematical model...
Spectrally resolved spatiotemporal features of quantum paths in high-order harmonic generation
He, Lixin; Zhang, Qingbin; Zhai, Chunyang; Wang, Feng; Shi, Wenjing; Lu, Peixiang
2015-01-01T23:59:59.000Z
We experimentally disentangle the contributions of different quantum paths in high-order harmonic generation (HHG) from the spectrally and spatially resolved harmonic spectra. By adjusting the laser intensity and focusing position, we simultaneously observe the spectrum splitting, frequency shift and intensity-dependent modulation of harmonic yields both for the short and long paths. Based on the simulations, we discriminate the physical mechanisms of the intensity-dependent modulation of HHG due to the quantum path interference and macroscopic interference effects. Moreover, it is shown that the atomic dipole phases of different quantum paths are encoded in the frequency shift. In turn, it enables us to retrieve the atomic dipole phases and the temporal chirps of different quantum paths from the measured harmonic spectra. This result gives an informative mapping of spatiotemporal and spectral features of quantum paths in HHG.
Spectrum of the harmonic oscillator in a general noncommutative phase space
Mahouton Norbert Hounkonnou; Dine Ousmane Samary
2011-08-07T23:59:59.000Z
Harmonic oscillator, in 2-dimensional noncommutative phase space with non-vanishing momentum-momentum commutators, is studied using an algebraic approach. The corresponding eigenvalue problem is solved and discussed.
de Rooij, Michael Andrew (Clifton Park, NY); Steigerwald, Robert Louis (Burnt Hills, NY); Delgado, Eladio Clemente (Burnt Hills, NY)
2008-12-16T23:59:59.000Z
Photovoltaic power converter system including a controller configured to reduce load harmonics is provided. The system comprises a photovoltaic array and an inverter electrically coupled to the array to generate an output current for energizing a load connected to the inverter and to a mains grid supply voltage. The system further comprises a controller including a first circuit coupled to receive a load current to measure a harmonic current in the load current. The controller includes a second circuit to generate a fundamental reference drawn by the load. The controller further includes a third circuit for combining the measured harmonic current and the fundamental reference to generate a command output signal for generating the output current for energizing the load connected to the inverter. The photovoltaic system may be configured to compensate harmonic currents that may be drawn by the load.
Casimir Friction Force and Energy Dissipation for Moving Harmonic Oscillators
Johan S. Høye; Iver Brevik
2010-09-15T23:59:59.000Z
The Casimir friction problem for a pair of dielectric particles in relative motion is analyzed, utilizing a microscopic model in which we start from statistical mechanics for harmonically oscillating particles at finite temperature moving nonrelativistically with constant velocity. The use of statistical mechanics in this context has in our opinion some definite advantages, in comparison with the more conventional quantum electrodynamic description of media that involves the use of a refractive index. The statistical-mechanical description is physical and direct, and the oscillator model, in spite of its simplicity, is nevertheless able to elucidate the essentials of the Casimir friction. As is known, there are diverging opinions about this kind of friction in the literature. Our treatment elaborates upon, and extends, an earlier theory presented by us back in 1992. There we found a finite friction force at any finite temperature, whereas at zero temperature the model led to a zero force. As an additional development in the present paper we evaluate the energy dissipation making use of an exponential cutoff truncating the relative motion of the oscillators. For the dissipation we also establish a general expression that is not limited to the simple oscillator model.
First Exit Times of Harmonically Trapped Particles: A Didactic Review
D. S. Grebenkov
2014-11-13T23:59:59.000Z
We revise the classical problem of characterizing first exit times of a harmonically trapped particle whose motion is described by one- or multi-dimensional 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 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.
Dynamically self-regular quantum harmonic black holes
Spallucci, Euro
2015-01-01T23:59:59.000Z
The recently proposed UV self-complete quantum gravity program is a new and very interesting way to envision Planckian/trans-Planckian physics. in this new framework, high energy scattering is dominated by the creation of micro black holes, and it is experimentally impossible to probe distances shorter than the horizon radius. In this letter we present a model which realizes this idea through the creation of self-regular quantum black holes admitting a minimal size extremal configuration. Their radius provides a dynamically generated minimal length acting as a universal short-distance cut-off. We propose a quantisation scheme for this new kind of microscopic objects based on a Bohr-like approach, which does not require a detailed knowledge of quantum gravity. The resulting black hole quantum picture resembles the energy spectrum of a quantum harmonic oscillator. The mass of the extremal configuration plays the role of zero-point energy. Large quantum number re-establish the classical black hole description. F...
High-harmonic XUV source for time- and angle-resolved photoemission spectroscopy
Dakovski, Georgi L [Los Alamos National Laboratory; Li, Yinwan [Los Alamos National Laboratory; Durakiewicz, Tomasz [Los Alamos National Laboratory; Rodriguez, George [Los Alamos National Laboratory
2009-01-01T23:59:59.000Z
We present a laser-based apparatus for visible pump/XUV probe time- and angle-resolved photoemission spectroscopy (TRARPES) utilizing high-harmonic generation from a noble gas. Femtosecond temporal resolution for each selected harmonic is achieved by using a time-delay-compensated monochromator (TCM). The source has been used to obtain photoemission spectra from insulators (UO{sub 2}) and ultrafast pump/probe processes in semiconductors (GaAs).
A solid-state, harmonic restraint, differential relay for transformer protection
Lowther, Gary Roger
1982-01-01T23:59:59.000Z
A SOLID-STATE, HARMONIC RESTRAINT, DIF ERENTIAL RELAY &Y)R TRANSFORMER PROTECTION A Thesis by GARY ROGER I OWTHER Submitted to the Graduate College of Texas ALM University in oartial ulfillment of the requirement for the degree of MASTER... of Department ) (~~Iember ) (1;ember ) (1 mber ) (Hember ) ABSTRACT A Solid-State, Harmonic Restraint, Differential Relay for Transformer Protection. (May 1982) Gary Roger Lowther, B. S. , College of Steubenville Chairman of Advisory Committee: Dr. B. Don...
Second harmonic generation from direct band gap quantum dots pumped by femtosecond laser pulses
Liu, Liwei, E-mail: liulw@cust.edu.cn; Wang, Yue; Hu, Siyi; Ren, Yu; Huang, Chen [School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, People's Republic of China and International Joint Research Center for Nanophotonics and Biophotonics, Changchun University of Science and Technology, Changchun, Jilin 130022 (China)
2014-02-21T23:59:59.000Z
We report on nonlinear optical experiments performed on Cu{sub 2}S quantum dots (QDs) pumped by femtosecond laser pulses. We conduct a theoretical simulation and experiments to determine their second harmonic generation characteristics. Furthermore, we demonstrate that the QDs have a second harmonic generation conversion efficiency of up to 76%. Our studies suggest that these Cu{sub 2}S QDs can be used for solar cells, bioimaging, biosensing, and electric detection.
Ole Steuernagel
2014-06-17T23:59:59.000Z
In quantum physics the free particle and the harmonically trapped particle are arguably the most important systems a physicist needs to know about. It is little known that, mathematically, they are one and the same. This knowledge helps us to understand either from the viewpoint of the other. Here we show that all general time-dependent solutions of the free-particle Schroedinger equation can be mapped to solutions of the Schroedinger equation for harmonic potentials, both the trapping oscillator and the inverted 'oscillator'. This map is fully invertible and therefore induces an isomorphism between both types of system, they are equivalent. A composition of the map and its inverse allows us to map from one harmonic oscillator to another with a different spring constant and different center position. The map is independent of the state of the system, consisting only of a coordinate transformation and multiplication by a form factor, and can be chosen such that the state is identical in both systems at one point in time. This transition point in time can be chosen freely, the wave function of the particle evolving in time in one system before the transition point can therefore be linked up smoothly with the wave function for the other system and its future evolution after the transition point. Such a cut-and-paste procedure allows us to describe the instantaneous changes of the environment a particle finds itself in. Transitions from free to trapped systems, between harmonic traps of different spring constants or center positions, or, from harmonic binding to repulsive harmonic potentials are straightforwardly modelled. This includes some time-dependent harmonic potentials. The mappings introduced here are computationally more efficient than either state-projection or harmonic oscillator propagator techniques conventionally employed when describing instantaneous (non-a 1,920 characters
Attachment of second harmonic-active moiety to molecules for detection of molecules at interfaces
Salafsky, Joshua S.; Eisenthal, Kenneth B.
2005-10-11T23:59:59.000Z
This invention provides methods of detecting molecules at an interface, which comprise labeling the molecules with a second harmonic-active moiety and detecting the labeled molecules at the interface using a surface selective technique. The invention also provides methods for detecting a molecule in a medium and for determining the orientation of a molecular species within a planar surface using a second harmonic-active moiety and a surface selective technique.
Israel Lazo; Chenhui Peng; Jie Xiang; Sergij V. Shiyanovskii; Oleg D. Lavrentovich
2014-08-11T23:59:59.000Z
Electrically-controlled dynamics of fluids and particles at microscales is a fascinating area of research with applications ranging from microfluidics and sensing to sorting of biomolecules. The driving mechanisms are electric forces acting on spatially separated charges in an isotropic medium such as water. Here we demonstrate that anisotropic conductivity of liquid crystals enables new mechanism of highly efficient electro-osmosis rooted in space charging of regions with distorted orientation. The electric field acts on these distortion-separated charges to induce liquid crystal-enabled electro-osmosis (LCEO). LCEO velocities grow with the square of the field, which allows one to use an AC field to drive steady flows and to avoid electrode damage. Ionic currents in liquid crystals that have been traditionally considered as an undesirable feature in displays, offer a broad platform for versatile applications such as liquid crystal enabled electrokinetics, micropumping and mixing.
Levin, I.; Krayzman, V.; Woicik, J. C. [Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Tucker, M. G. [ISIS Facility, Rutherford Appleton Laboratory, Didcot (United Kingdom)
2014-06-16T23:59:59.000Z
The local structure of tetragonal BiFeO{sub 3}-PbTiO{sub 3} solid solutions featuring anomalous lattice distortions has been determined using simultaneous fitting of neutron total scattering and extended X-ray absorption fine structure data. On the local scale, the large tetragonal distortion, promoted by the displacements of the A-cations (Bi and Pb), is accommodated primarily by the [FeO{sub 6}] octahedra, even though both Fe and Ti acquire (5+1)-fold coordination. Bi cations exhibit considerably larger displacements than Pb. The combination of the A-cation displacements and the ability of M-cations to adopt 5-fold coordination is suggested as key for stabilizing the large tetragonality in BiMO{sub 3}-PbTiO{sub 3} systems.
Harmonic mode competition in a terahertz gyrotron backward-wave oscillator
Kao, S. H.; Chiu, C. C.; Chang, P. C.; Wu, K. L.; Chu, K. R. [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)
2012-10-15T23:59:59.000Z
Electron cyclotron maser interactions at terahertz (THz) frequencies require a high-order-mode structure to reduce the wall loss to a tolerable level. To generate THz radiation, it is also essential to employ cyclotron harmonic resonances to reduce the required magnetic field strength to a value within the capability of the superconducting magnets. However, much weaker harmonic interactions in a high-order-mode structure lead to serious mode competition problems. The current paper addresses harmonic mode competition in the gyrotron backward wave oscillator (gyro-BWO). We begin with a comparative study of the mode formation and oscillation thresholds in the gyro-BWO and gyromonotron. Differences in linear features result in far fewer 'windows' for harmonic operation of the gyro-BWO. Nonlinear consequences of these differences are examined in particle simulations of the multimode competition processes in the gyro-BWO, which shed light on the competition criteria between modes of different as well as the same cyclotron harmonic numbers. The viability of a harmonic gyro-BWO is assessed on the basis of the results obtained.
Electron cyclotron harmonic resonances in high-frequency heating of the ionosphere
Kuo, Spencer P. [Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, New York 11201 (United States)] [Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, New York 11201 (United States)
2013-09-15T23:59:59.000Z
Electron acceleration by upper hybrid waves under cyclotron harmonic resonance interaction is studied. Theory is formulated; the analytical solutions in the second and fourth harmonic cyclotron resonance cases are obtained, and in the third harmonic case, a first order differential equation governing the evolution of the electron energy is derived. The theory is applied for explaining the generation of artificial ionization layers observed in high-frequency (HF) ionospheric heating experiments. The upper hybrid waves are assumed to be excited parametrically by the O-mode HF heating wave. As the decay mode is the lower hybrid wave, the excited upper hybrid waves have wavelengths ranging from 0.25 to 0.5 m, which are short enough to effectively incorporate the finite Larmour radius effect for the harmonic cyclotron resonance interactions as well as have a frequency bandwidth of about 20 kHz, which provides an altitude region of about 10 km for continuous harmonic cyclotron resonance interaction between electrons and descending waves in the slightly inhomogeneous geomagnetic field. The numerical results on electron acceleration show that electron fluxes with energies larger than 14 eV are generated in the three harmonic cases. These energetic electrons cause impact ionizations, which are descending to form artificial ionization layers at the bottom of the ionospheric F region.
The information content of gravitational wave harmonics in compact binary inspiral
Ronald W. Hellings; Thomas A. Moore
2002-07-25T23:59:59.000Z
The nonlinear aspect of gravitational wave generation that produces power at harmonics of the orbital frequency, above the fundamental quadrupole frequency, is examined to see what information about the source is contained in these higher harmonics. We use an order (4/2) post-Newtonian expansion of the gravitational wave waveform of a binary system to model the signal seen in a spaceborne gravitational wave detector such as the proposed LISA detector. Covariance studies are then performed to determine the ultimate accuracy to be expected when the parameters of the source are fit to the received signal. We find three areas where the higher harmonics contribute crucial information that breaks degeneracies in the model and allows otherwise badly-correlated parameters to be separated and determined. First, we find that the position of a coalescing massive black hole binary in an ecliptic plane detector, such as OMEGA, is well-determined with the help of these harmonics. Second, we find that the individual masses of the stars in a chirping neutron star binary can be separated because of the mass dependence of the harmonic contributions to the wave. Finally, we note that supermassive black hole binaries, whose frequencies are too low to be seen in the detector sensitivity window for long, may still have their masses, distances, and positions determined since the information content of the higher harmonics compensates for the information lost when the orbit-induced modulation of the signal does not last long enough to be apparent in the data.
mm-WAVE Op-Amps FOR LOW DISTORTION AMPLIFICATION WITH HIGH OIP3/PDC RATIO > 100 AT 2 GHz
Rodwell, Mark J. W.
mm-WAVE Op-Amps FOR LOW DISTORTION AMPLIFICATION WITH HIGH OIP3/PDC RATIO > 100 AT 2 GHz Zach in bandwidth for an op-amp of any kind, as well as 3Ã? betterment in OIP3/PDC ratio at fs = 2-3 GHz, when dissipation PDC. This very high ratio of third-order-intercept power to DC power consumption POIP 3/PDC > 100
Low efficiency gratings for 3rd harmonic diagnostics applications
Britten, J.A.; Boyd, R.D.; Perry, M.D.; Shore, B.W.; Thomas, I.M.
1995-08-09T23:59:59.000Z
The baseline design of the National Ignition Facility (NIF) calls for sampling gratings to provide third-harmonic energy diagnostics in the highly constrained area of the target chamber. These 40 {times} 4O cm transmission gratings are to diffract at (order +1) nominally 0.3% of the incident 351 run light at a small angle on to a focusing mirror and into a calorimeter. The design calls for a plane grating of 500 lines/mm, and approximately 30 run deep, etched into a fused silica focusing lens and subsequently overcoated with a solgel anti reflective coating. Gratings of similar aperture and feature size have been produced for other applications by ion etching processes, but, in an effort to reduce substantially the cost of such optics, we are studying the feasibility of making these gratings by wet chemical etching techniques. Experimentation with high-quality fused silica substrates on 5 and 15 cm. scale has led to a wet etching process which can meet the design goals and which offers no significant scaleup barriers to full sized optics. The grating is produced by holographic exposure and a series of processing steps using only a photoresist mask and a final hydrofluoric acid etch. Gratings on 15 cm diameter test substrates exhibit absolute diffraction efficiencies from 0.2--0.4% with a standard deviation of about 15% of the mean over the full aperture. The efficiency variation is due to variation in linewidth caused by spatial nonuniformities in exposure energy. Uniformity improvements can be realized by using a smaller, more uniform portion of the exposure beam and exposing for longer times. The laser damage threshold for these gratings has been measured at LLNL and found to be identical to that of the fused silica substrate.
Fallier, William F. (William Frederick)
2007-01-01T23:59:59.000Z
This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an ...
Models of soft rotators and the theory of a harmonic rotator
Zahid Zakir
2012-12-12T23:59:59.000Z
The states of a planar oscillator are separated to a vibrational mode, containing a zero-point energy, and a rotational mode without the zero-point energy, but having a conserved angular momentum. On the basis of the analysis of properties of models of rigid and semirigid rotators, the theory of soft rotators is formulated where the harmonic attractive force is balanced only by the centrifugal force. As examples a Coulomb rotator (the Bohr model) and a magneto-harmonic rotator (the Fock-Landau levels) are considered. Disappearance of the radial speed in the model of a magneto-harmonic rotator is taken as a defining property of a pure rotational motion in the harmonic potential. After the exception of energies of the magnetic and spin decompositions, specific to magnetic fields, one turns to a simple and general model of a planar harmonic rotator (circular oscillator without radial speed) where kinetic energy is reduced to the purely rotational energy. Energy levels of the harmonic rotator have the same frequency and are twice degenerate, the energy spectrum is equidistant. In the ground state there is no zero-point energy from rotational modes, and the zero-point energy of vibrational modes can be compensated by spin effects or symmetries of the system. In this case the operators of observables vanish the ground state, i.e. are "strongly" normally ordered. In a chain of harmonic rotators collective rotations around a common axis lead to transverse waves, at quantization of which there appear quasi-particles and holes carrying an angular momentum. In the chain SU(2) appears as a group of symmetry of a rotator.
Distribution function approach to redshift space distortions. Part III: halos and galaxies
Okumura, Teppei; Seljak, Uroš [Institute for the Early Universe, Ewha Womans University, Seoul 120-750, S. Korea (Korea, Republic of); Desjacques, Vincent, E-mail: teppei@ewha.ac.kr, E-mail: useljak@berkeley.edu, E-mail: dvince@physik.uzh.ch [Département de Physique Théorique and Center for Astroparticle Physics (CAP), Université de Genève, 1211 Genève (Switzerland)
2012-11-01T23:59:59.000Z
It was recently shown that the power spectrum in redshift space can be written as a sum of cross-power spectra between number weighted velocity moments, of which the lowest are density and momentum density. We investigate numerically the properties of these power spectra for simulated galaxies and dark matter halos and compare them to the dark matter power spectra, generalizing the concept of the bias in density-density power spectra. Because all of the quantities are number weighted this approach is well defined even for sparse systems such as massive halos. This contrasts to the previous approaches to RSD where velocity correlations have been explored, but velocity field is a poorly defined concept for sparse systems. We find that the number density weighting leads to a strong scale dependence of the bias terms for momentum density auto-correlation and cross-correlation with density. This trend becomes more significant for the more biased halos and leads to an enhancement of RSD power relative to the linear theory. Fingers-of-god effects, which in this formalism come from the correlations of the higher order moments beyond the momentum density, lead to smoothing of the power spectrum and can reduce this enhancement of power from the scale dependent bias, but are relatively small for halos with no small scale velocity dispersion. In comparison, for a more realistic galaxy sample with satellites the small scale velocity dispersion generated by satellite motions inside the halos leads to a larger power suppression on small scales, but this depends on the satellite fraction and on the details of how the satellites are distributed inside the halo. We investigate several statistics such as the two-dimensional power spectrum P(k,?), where ? is the angle between the Fourier mode and line of sight, its multipole moments, its powers of ?{sup 2}, and configuration space statistics. Overall we find that the nonlinear effects in realistic galaxy samples such as luminous red galaxies affect the redshift space clustering on very large scales: for example, the quadrupole moment is affected by 10% for k < 0.1hMpc{sup ?1}, which means that these effects need to be understood if we want to extract cosmological information from the redshift space distortions.
Jha, Pallavi; Agrawal, Ekta [Department of Physics, University of Lucknow, Lucknow-226007 (India)
2014-05-15T23:59:59.000Z
An analytical study of second harmonic generation due to interaction an intense, p-polarized laser beam propagating obliquely in homogeneous underdense plasma, in the mildly relativistic regime, has been presented. The efficiency of the second harmonic radiation as well as its detuning length has been obtained and their variation with the angle of incidence is analyzed. It is shown that, for a given plasma electron density, the second harmonic efficiency increases with the angle of incidence while the detuning length decreases. The second harmonic amplitude vanishes at normal incidence of the laser beam.
Scaling of the generation of high-order harmonics in large gas media with focal length
Boutu, W.; Auguste, T.; Caumes, J. P.; Carre, B. [Service des Photons, Atomes et Molecules, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France); Merdji, H. [Service des Photons, Atomes et Molecules, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France); PULSE Institute for Ultrafast Energy Science, Stanford Linear Accelerator Center, Stanford University, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)
2011-11-15T23:59:59.000Z
We present theoretical and experimental results on high-order harmonic generation in a low-density few-centimeter-long gas medium (L{sub med}{<=} 10 cm). We study the dependence with focal length of harmonic efficiency. Theoretically, we consider in detail the generation of the 25th harmonic of a short pulse Ti:sapphire laser in argon. Within the strong-field approximation for the atomic dipole, and a complete account of the macroscopic propagation, we compute the number of photons produced as a function of the medium parameters and the focusing conditions. The simulations show that, at constant intensity, the emission of the 25th harmonic scales with the focal length as {approx}f{sup 4} at low pressure (P=2 Torr) and as {approx}f{sup 6} at higher pressure (P=5 Torr). At constant laser energy, we find that the harmonic signal scales approximately as f{sup 2} at low pressure and as f{sup 4} at higher pressure. Those numerical results are compared with experimental data.
Low-order-mode harmonic multiplying gyrotron traveling-wave amplifier in W band
Yeh, Y. S.; Chen, C. H.; Yang, S. J.; Lai, C. H.; Lin, T. Y.; Lo, Y. C.; Hong, J. W. [Department of Electro-Optical Engineering, Southern Taiwan University, Tainan, Taiwan (China); Hung, C. L. [Department of Communication Engineering, National Penghu University of Science and Technology, Penghu, Taiwan (China); Chang, T. H. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China)
2012-09-15T23:59:59.000Z
Harmonic multiplying gyrotron traveling-wave amplifiers (gyro-TWAs) allow for magnetic field reduction and frequency multiplication. To avoid absolute instabilities, this work proposes a W-band harmonic multiplying gyro-TWA operating at low-order modes. By amplifying a fundamental harmonic TE{sub 11} drive wave, the second harmonic component of the beam current initiates a TE{sub 21} wave to be amplified. Absolute instabilities in the gyro-TWA are suppressed by shortening the interaction circuit and increasing wall losses. Simulation results reveal that compared with Ka-band gyro-TWTs, the lower wall losses effectively suppress absolute instabilities in the W-band gyro-TWA. However, a global reflective oscillation occurs as the wall losses decrease. Increasing the length or resistivity of the lossy section can reduce the feedback of the oscillation to stabilize the amplifier. The W-band harmonic multiplying gyro-TWA is predicted to yield a peak output power of 111 kW at 98 GHz with an efficiency of 25%, a saturated gain of 26 dB, and a bandwidth of 1.6 GHz for a 60 kV, 7.5 A electron beam with an axial velocity spread of 8%.
Kato, Kosaku; Minemoto, Shinichirou; Sakai, Hirofumi [Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
2011-08-15T23:59:59.000Z
High-order-harmonic generation from aligned N{sub 2}, O{sub 2}, and CO{sub 2} molecules is investigated by 1300-nm and 800-nm pulses. The harmonic intensities of 1300-nm pulses from aligned molecules show harmonic photon energy dependence similar to those of 800-nm pulses. Suppression of harmonic intensity from aligned CO{sub 2} molecules is observed for both 1300- and 800-nm pulses over the same harmonic photon energy range. As the dominant mechanism for the harmonic intensity suppression from aligned CO{sub 2} molecules, the present results support the two-center interference picture rather than the dynamical interference picture.
Zhang, Hao Chi; Guo, Jian; Fu, Xiaojian; Li, Lianming; Qian, Cheng; Cui, Tie Jun
2015-01-01T23:59:59.000Z
The second harmonic generation is one of the most important applications of nonlinear effect, which has attracted great interests in nonlinear optics and microwave in the past decades. To the best of our knowledge, however, generating the second harmonics of surface plasmon polaritons (SPPs) has not been reported. Here, we propose to generate the second harmonics of spoof SPPs with high efficiency at microwave frequencies using subwavelength-scale nonlinear active device integrated on specially designed plasmonic waveguides, which are composed of two ultrathin corrugated metallic strips printed on the top and bottom surfaces of a thin dielectric slab anti-symmetrically. We show that the plasmonic waveguide supports broadband propagations of spoof SPPs with strong subwavelength effect, whose dispersion property can be controlled by changing the geometrical parameters. By loading the nonlinear device made from semiconductors to the intersection of two plasmonic waveguides with different corrugation depths, we e...
Role of ellipticity in high-order harmonic generation by homonuclear diatomic molecules
Odzak, S. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, D-12489 Berlin (Germany)
2010-08-15T23:59:59.000Z
We present a theory of high-order harmonic generation by diatomic molecules exposed to an elliptically polarized laser field. This theory is based on the molecular strong-field approximation with the laser-field-dressed initial bound state and the undressed final state. The interference minima, observed for linear polarization, are blurred with the increase of the laser-field ellipticity. The nth harmonic emission rate has contributions of the components of the T-matrix element in the direction of the laser-field polarization and in the direction perpendicular to it. We analyze the destructive interference condition for this perpendicular component. Taking into account that the aligned molecules are an anisotropic medium for high-harmonic generation, we introduce elliptic dichroism as a measure of this anisotropy and discuss possibilities of its use for determining the molecular structure.
Guo, Y.; Keller, J.; Parker, R. G.
2012-06-01T23:59:59.000Z
The dynamics of wind turbine planetary gears with gravity effects are investigated using an extended harmonic balance method that extends established harmonic balance formulations to include simultaneous internal and external excitations. The extended harmonic balance method with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the planetary gear dynamic response. The calculated responses compare well with time domain integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gears and plays an important role in system dynamics, causing hardening effects induced by tooth wedging and bearing-raceway contacts. Bearing clearance significantly reduces the lowest resonant frequencies of translational modes. Gravity and bearing clearance together lowers the speed at which tooth wedging occurs lower than the resonant frequency.
Improved quantum correlations in second harmonic generation with a squeezed pump
E. MArcellina; J. F. Corney; M. K. Olsen
2013-02-11T23:59:59.000Z
We investigate the effects of a squeezed pump on the quantum properties and conversion efficiency of the light produced in single-pass second harmonic generation. Using stochastic integration of the two-mode equations of motion in the positive-P representation, we find that larger violations of continuous-variable harmonic entanglement criteria are available for lesser effective interaction strengths than with a coherent pump. This enhancement of the quantum properties also applies to violations of the Reid-Drummond inequalities used to demonstrate a harmonic version of the Einstein-Podolsky-Rosen paradox. We find that the conversion efficiency is largely unchanged except for very low pump intensities and high levels of squeezing.
Nonadiabatic molecular high-order harmonic generation from polar molecules: Spectral redshift
Bian Xuebin; Bandrauk, Andre D. [Departement de Chimie, Universite de Sherbrooke, Sherbrooke, Quebec, J1K 2R1 (Canada)
2011-04-15T23:59:59.000Z
Molecular high-order harmonic generation (MHOHG) from the polar diatomic molecule HeH{sup 2+} in short intense laser fields is studied numerically. Due to the nonadiabatic response of the molecular dipole to the rapid change of laser intensity, a spectral redshift is predicted in high-intensity and ultrashort laser pulses, contrary to the blueshift observed in the harmonics generated from atoms in long laser pulses. The MHOHG temporal structures are investigated by a wavelet time-frequency analysis, which shows that the enhanced excitation of localized long lifetime excited states shifts the harmonic generation spectrum in the falling part of short laser pulses, due to the presence of a permanent dipole moment, and thus is unique to polar molecules.
Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin, E-mail: panxiaoyin@nbu.edu.cn [Department of Physics, Ningbo University, Ningbo 315211 (China)] [Department of Physics, Ningbo University, Ningbo 315211 (China); Sahni, Viraht [Department of Physics, Brooklyn College and The Graduate School of the City University of New York, New York, New York 10016 (United States)] [Department of Physics, Brooklyn College and The Graduate School of the City University of New York, New York, New York 10016 (United States)
2014-01-14T23:59:59.000Z
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.
Generation of high order optical harmonics in steep plasma density gradients
Linde, D. von der [Institut fuer Laser- und Plasmaphysik, Universitaet Essen, D-45117 Essen (Germany)
1998-02-20T23:59:59.000Z
During the interaction of an intense ultrashort laser pulse with solid targets a thin layer of surface plasma is generated in which the density drops to the vacuum level in a distance much shorter than the wavelength. This sharp plasma-vacuum boundary performs an oscillatory motion in response to the electromagnetic forces of the intense laser light. It is shown that the generation of reflected harmonics can be interpreted as a phase modulation experienced by the light upon reflection from the oscillating boundary. The modulation sidebands of the reflected frequency spectrum correspond to odd and even harmonics of the laser frequency. Retardation effects lead to a strong anharmonicity for high velocities of the plasma-vacuum boundary. As a result, harmonic generation is strongly enhanced in the relativistic regime of laser intensities.
Noncommutative quantum mechanics of a harmonic oscillator under linearized gravitational waves
Anirban Saha; Sunandan Gangopadhyay; Swarup Saha
2011-06-09T23:59:59.000Z
We consider the quantum dynamics of a harmonic oscillator in noncommutative space under the influence of linearized gravitational waves (GW) in the long wave-length and low-velocity limit. Following the prescription in \\cite{ncgw1} we quantize the system. The Hamiltonian of the system is solved by using standard algebraic iterative methods. The solution shows signatures of the coordinate noncommutativity via alterations in the oscillation frequency of the harmonic oscillator system from its commutative counterpart. Moreover, it is found that the response of the harmonic oscillator to periodic GW, when their frequencies match, will oscillate with a time scale imposed by the NC parameter. We expect this noncommutative signature to show up as some noise source in the GW detection experiments since the recent phenomenological upper-bounds set on spatial noncommutative parameter implies a length-scale comparable to the length-variations due to the passage of gravitational waves, detectable in the present day GW detectors.
Theory of high harmonic generation in relativistic laser interaction with overdense plasma
T. Baeva; S. Gordienko; A. Pukhov
2006-04-28T23:59:59.000Z
High harmonic generation due to the interaction of a short ultra relativistic laser pulse with overdense plasma is studied analytically and numerically. On the basis of the ultra relativistic similarity theory we show that the high harmonic spectrum is universal, i.e. it does not depend on the interaction details. The spectrum includes the power law part $I_n\\propto n^{-8/3}$ for $nharmonic cutoff at $\\propto \\gamma_{\\max}^3$ is parametrically larger than the $4 \\gamma_{\\max}^2$ predicted by the ``oscillating mirror'' model based on the Doppler effect. The cornerstone of our theory is the new physical phenomenon: spikes in the relativistic $\\gamma$-factor of the plasma surface. These spikes define the high harmonic spectrum and lead to attosecond pulses in the reflected radiation.
Harmonic mixing in two coupled qubits: quantum synchronization via ac drives
S. E. Savel'ev; Z. Washington; A. M. Zagoskin; M. J. Everitt
2012-10-12T23:59:59.000Z
Simulating a system of two driven coupled qubits, we show that the time-averaged probability to find one driven qubit in its ground or excited state can be controlled by an ac drive in the second qubit. Moreover, off-diagonal elements of the density matrix responsible for quantum coherence can also be controlled via driving the second qubit, i.e., quantum coherence can be enhanced by appropriate choice of the bi-harmonic signal. Such a dynamic synchronization of two differently driven qubits has an analogy with harmonic mixing of Brownian particles forced by two signals through a substrate. Nevertheless, the quantum synchronization in two qubits occurs due to multiplicative coupling of signals in the qubits rather than via a nonlinear harmonic mixing for a classical nano-particle.
Nonlinear absorption and harmonic generation of laser in a gas with anharmonic clusters
Kumar, Manoj; Tripathi, V. K. [Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)
2013-02-15T23:59:59.000Z
The nonlinear absorption and harmonic generation of intense short pulse laser in a gas embedded with anharmonic clusters are investigated theoretically. When the laser induced excursion of cluster electrons becomes comparable to cluster radius, the restoration force on electrons no longer remains linearly proportional to the excursion. As a consequence, the plasmon resonance is broadened, leading to broadband laser absorption. It also leads to second and third harmonic generations, at much higher level than the one due to ponderomotive nonlinearity. The harmonic yield is resonantly enhanced at the plasmon resonance {omega}={omega}{sub pe}/{radical}(3), where {omega} is the frequency of the laser and {omega}{sub pe} is the plasma frequency of cluster electrons.
Cho, Suwon, E-mail: swcho@kgu.ac.kr [Department of Physics, Kyonggi University, Suwon, Kyonggi-Do 443-760 (Korea, Republic of)] [Department of Physics, Kyonggi University, Suwon, Kyonggi-Do 443-760 (Korea, Republic of); Kwak, Jong-Gu [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)] [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)
2014-04-15T23:59:59.000Z
The propagation and absorption of high harmonic fast waves is of interest for non-inductive current drives in fusion experiments. The fast wave can be coupled with the ion Bernstein wave that propagates in the high magnetic field side of an ion cyclotron harmonic resonance layer. This coupling and the absorption are analyzed using the hot plasma dispersion relation and a wave equation that was converted from an approximate dispersion relation for the case where ?{sub i}=k{sub ?}{sup 2}?{sub i}{sup 2}/2?1 (where k{sub ?} is the perpendicular wave number and ?{sub i} is the ion Larmor radius). It is found that both reflection and conversion may occur near the harmonic resonance layer but that they decrease rapidly, giving rise to a sharp increase in the absorption as the parallel wave number increases.
D. Martinez; J. C. Flores-Urbina; R. D. Mota; V. D. Granados
2010-05-21T23:59:59.000Z
We apply the Schr\\"odinger factorization to construct the ladder operators for hydrogen atom, Mie-type potential, harmonic oscillator and pseudo-harmonic oscillator in arbitrary dimensions. By generalizing these operators we show that the dynamical algebra for these problems is the $su(1,1)$ Lie algebra.
Huge enhancement of backward second-harmonic generation with slow light in photonic crystals
Iliew, Rumen [Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Institute of Condensed Matter Theory and Solid State Optics, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Etrich, Christoph; Pertsch, Thomas [Institute of Applied Physics/Ultra Optics, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Lederer, Falk [Institute of Condensed Matter Theory and Solid State Optics, Friedrich-Schiller-Universitaet Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Kivshar, Yuri S. [Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)
2010-02-15T23:59:59.000Z
We study theoretically forward and backward second-harmonic generation in a two-dimensional photonic crystal structure made of lithium niobate. The aim of this article is twofold: First, we propose a reliable modal algorithm for describing the light propagation taking into account the vectorial character of the interacting fields as well as the tensorial character of the nonlinearity and verify it by means of the nonlinear finite-difference time-domain method. Second, we propose a photonic crystal where we obtain a giant efficiency increase for backward second-harmonic generation with slow light.
Kim, Young-Do; Kim, Yu-Sin; Lee, Hyo-Chang; Bang, Jin-Young; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, 17 Heangdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of)
2011-03-15T23:59:59.000Z
The characteristics of probe currents induced by applying various probe voltage waveforms, such as sinusoidal, sawtooth, square, and triangular, were investigated at a floating potential. It was found that the measured probe currents have many harmonics depending on the voltage waveforms. This was mainly due to the nonlinearity of the sheath in the plasma and was analyzed using the fast Fourier transform and a circuit model. By applying a triangular voltage waveform to a probe, plasma parameters such as electron temperature and plasma density could be obtained and compared to those of a single Langmuir probe and a floating harmonic method.
Heath, G.; O'Donoughue, P.; Whitaker, M.
2012-12-01T23:59:59.000Z
This research provides a systematic review and harmonization of the life cycle assessment (LCA) literature of electricity generated from conventionally produced natural gas. We focus on estimates of greenhouse gases (GHGs) emitted in the life cycle of electricity generation from conventionally produced natural gas in combustion turbines (NGCT) and combined-cycle (NGCC) systems. A process we term "harmonization" was employed to align several common system performance parameters and assumptions to better allow for cross-study comparisons, with the goal of clarifying central tendency and reducing variability in estimates of life cycle GHG emissions. This presentation summarizes preliminary results.
Chaudhuri, A K
2012-01-01T23:59:59.000Z
In nucleon-nucleon collisions, charged particle's multiplicity fluctuates. We have studied the effect of multiplicity fluctuation on flow harmonics in nucleus-nucleus collision in event-by-event hydrodynamics. Assuming that the charged particle's multiplicity fluctuations are governed by the negative binomial distribution, the Monte-Carlo Glauber model of initial condition is generalised to include the fluctuations. Explicit simulations with the generalised Monte-Carlo Glauber model initial conditions indicate that the multiplicity fluctuations do not have large effect on the flow harmonics.
A. K. Chaudhuri
2013-03-19T23:59:59.000Z
In nucleon-nucleon collisions, charged particle's multiplicity fluctuates. We have studied the effect of multiplicity fluctuation on flow harmonics in nucleus-nucleus collision in event-by-event hydrodynamics. Assuming that the charged particle's multiplicity fluctuations are governed by the negative binomial distribution, the Monte-Carlo Glauber model of initial condition is generalised to include the fluctuations. Explicit simulations with the generalised Monte-Carlo Glauber model initial conditions indicate that the multiplicity fluctuations do not have large effect on the flow harmonics.
The harmonic impact of electric vehicle battery chargers on residential power distribution
Wang, Y.; O`Connell, R.M. [Univ. of Missouri, Columbia, MO (United States). Dept. of Electrical Engineering; Brownfield, G. [Ameren Services, St. Louis, MO (United States)
1999-11-01T23:59:59.000Z
Electric vehicles (EV), which are powered by battery-driven electric motors, are becoming an ecologically attractive alternative to gasoline driven vehicles. One drawback to them is that the associated battery chargers are power electronic circuits which, because of their non-linear nature, can produce deleterious harmonic effects on the electric utility distribution system. To investigate the harmonic effects of widespread use of EV battery chargers, three different commercially available EV battery chargers are modeled using the injection current method to represent their current waveforms for simulation in a SPICE model of a particular distribution system.
Second harmonic generation in photonic crystal cavities in (111)-oriented GaAs
Buckley, Sonia, E-mail: bucklesm@stanford.edu; Radulaski, Marina; Vu?kovi?, Jelena [E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305 (United States)] [E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305 (United States); Biermann, Klaus [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin (Germany)] [Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin (Germany)
2013-11-18T23:59:59.000Z
We demonstrate second harmonic generation at telecommunications wavelengths in photonic crystal cavities in (111)-oriented GaAs. We fabricate 30 photonic crystal structures in both (111)- and (100)-oriented GaAs and observe an increase in generated second harmonic power in the (111) orientation, with the mean power increased by a factor of 3, although there is a large scatter in the measured values. We discuss possible reasons for this increase, in particular, the reduced two photon absorption for transverse electric modes in (111) orientation, as well as a potential increase due to improved mode overlap.
Advanced properties of extended plasmas for efficient high-order harmonic generation
Ganeev, R. A. [Ophthalmology and Advanced Laser Medical Center, Saitama Medical University, Saitama 350-0495 (Japan) [Ophthalmology and Advanced Laser Medical Center, Saitama Medical University, Saitama 350-0495 (Japan); Physics Department, Voronezh State University, Voronezh 394006 (Russian Federation); Suzuki, M.; Kuroda, H. [Ophthalmology and Advanced Laser Medical Center, Saitama Medical University, Saitama 350-0495 (Japan)] [Ophthalmology and Advanced Laser Medical Center, Saitama Medical University, Saitama 350-0495 (Japan)
2014-05-15T23:59:59.000Z
We demonstrate the advanced properties of extended plasma plumes (5?mm) for efficient harmonic generation of laser radiation compared with the short lengths of plasmas (?0.3–0.5?mm) used in previous studies. The harmonic conversion efficiency quadratically increased with the growth of plasma length. The studies of this process along the whole extreme ultraviolet range using the long plasma jets produced on various metal surfaces, particularly including the resonance-enhanced laser frequency conversion and two-color pump, are presented. Such plasmas could be used for the quasi-phase matching experiments by proper modulation of the spatial characteristics of extended ablating area and formation of separated plasma jets.
Internal Decoherence of a Gaussian Wave Packet in a Harmonic Potential
A. Cidrim; F. E. A. dos Santos; A. O. Caldeira
2014-07-16T23:59:59.000Z
We have studied the quantum dissipative problem of a Gaussian wave packet under the influence of a harmonic potential. A phenomenological approach to dissipation is adopted in the light of the well-known model in which the environment is composed of a bath of non-interacting harmonic oscillators. As one of the effects of the coupling to the bath is the evolution of an initially pure wave packet into a statistical mixture, we estimate the characteristic time elapsed for this to occur for different regimes of temperature, damping, and also different initial states.
Theoretical study of the dual harmonic system and its application on the CSNS/RCS
Yuan, Yao-Shuo; Xu, Shou-Yan; Yuan, Yue; Wang, Sheng
2015-01-01T23:59:59.000Z
The dual harmonic system has been widely used in high intensity proton synchrotrons to suppress the space charge effect, as well as reduce the beam loss. To investigate the longitudinal beam dynamics in the dual rf system, the potential well, the sub-buckets in the bunch and the multi-solutions of the phase equation have been studied theoretically. Based on these theoretical studis, the optimization of bunching factor and rf voltage waveform are made for the dual harmonic rf system in the upgrade phase of the CSNS/RCS. In the optimization process, the simulation with space charge effect is done by using a newly developed code C-SCSIM.
The harmonic oscillator with dissipation within the theory of open quantum systems
A. Isar
2005-08-18T23:59:59.000Z
Time evolution of the expectation values of various dynamical operators of the harmonic oscillator with dissipation is analitically obtained within the framework of the Lindblad theory for open quantum systems. We deduce the density matrix of the damped harmonic oscillator from the solution of the Fokker-Planck equation for the coherent state representation, obtained from the master equation for the density operator. The Fokker-Planck equation for the Wigner distribution function, subject to either the Gaussian type or the $\\delta$-function type of initial conditions, is also solved by using the Wang-Uhlenbeck method. The obtained Wigner functions are two-dimensional Gaussians with different widths.
Position-dependent noncommutative quantum models: Exact solution of the harmonic oscillator
Dine Ousmane Samary
2014-05-31T23:59:59.000Z
This paper is devoted to find the exact solution of the harmonic oscillator in a position-dependent 4-dimensional noncommutative phase space. The noncommutative phase space that we consider is described by the commutation relations between coordinates and momenta: $[\\hat{x}^1,\\hat{x}^2]=i\\theta(1+\\omega_2 \\hat x^2)$, $[\\hat{p}^1,\\hat{p}^2]=i\\bar\\theta$, $[\\hat{x}^i,\\hat{p}^j]=i\\hbar_{eff}\\delta^{ij}$. We give an analytical method to solve the eigenvalue problem of the harmonic oscillator within this deformation algebra.
Generation of 9 MeV -rays by all-laser-driven Compton scattering with second-harmonic laser light
Umstadter, Donald
Generation of 9 MeV -rays by all-laser-driven Compton scattering with second-harmonic laser light-harmonic-generated laser light (3 eV) inverse-Compton-scattered from a counterpropagating relativistic (450 MeV) laser in detection. Narrower band- width -rays are generated efficiently by means of inverse Compton scattering (ICS
Chem. Rev. 1994, 94, 107-125 107 Optical Second Harmonic Generation as a Probe of Surface Chemistry
Chem. Rev. 1994, 94, 107-125 107 Optical Second Harmonic Generation as a Probe of Surface Chemistry 109 IV. SHG Measurements of Surface Chemistry 109 VI. Acknowledgments 122 V II.References 122 V. Other Surface SHG Experiments and Future 122 Directions I. Introduction Optical second harmonic generation (SHG
Bak, Claus Leth
Abstract--This paper presents the harmonic analysis of offshore wind farm (OWF) models with full will be discussed based on measurements from offshore wind farm. Index Terms--full-rating converters, harmonic analysis, offshore wind farm, wind turbine, validation with measurements I. INTRODUCTION HE tendency
Itoh, Tatsuo
Output Harmonic Termination Techniques for AlGaN/GaN HEMT Power Amplifiers Using Active Integrated 1200, Los Angeles, CA 90045 Abstract -- In this paper, effects of output harmonic terminations on PAE termination, we observe a substantial increase in PAE and output power. Further, we demonstrate the high
Paris-Sud XI, Université de
/Simulink simulations. Key words: power system harmonics, power electronic, linear time periodic modeling, PWM, control1 POWER ELECTRONICS HARMONIC ANALYSIS BASED ON THE LINEAR TIME PERIODIC MODELING. APPLICATIONS in power electronic systems. The considered system is described by a set of differential equations, which
Reid, Matthew
time due to a growing number of applications such as imaging,13 illicit-drug detection,4Terahertz radiation and second-harmonic generation from InAs: Bulk versus surface electric July 2005 Polarized second-harmonic generation and terahertz radiation in reflection from 100 , 110
Dickmander, D.L.; Peterson, K.J.
1989-04-01T23:59:59.000Z
The harmonic analysis of the dc-side of an HVDC line transmission requires realistic models of the converters, the dc line, and other relevant equipment. These models must include all important paths for harmonic current, and appropriate sources of harmonic voltage generation. The classical converter modeling technique has been demonstrated to be insufficient in field measurements and analysis of the harmonic spectra found on recent HVDC line transmission. For this reason, a new model of the converter bridge which takes into account the major stray capacitances in the converter (the three-pulse model) has been developed, and is described in detail elsewhere. This paper presents comparisons between the classical and three-pulse calculations for the Intermountain Power Project (IPP) HVDC transmission. The calculation results from the three-pulse model agree favorably with the harmonics found in field measurements.
Kumar, M.; Singhal, H.; Chakera, J. A.; Naik, P. A.; Khan, R. A.; Gupta, P. D. [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, M.P. (India)
2013-07-21T23:59:59.000Z
A study of the spatial coherence of the high order harmonic radiation generated by the interaction of 45 fs Ti:sapphire laser beam with carbon (graphite) plasma plume has been carried out using Young's double slit interferometry. It is observed that the spatial coherence varies with harmonic order, laser focal spot size in plasma plume, and peaks at an optimal spot size. It is also observed that the spatial coherence is higher when the laser pulse is focused before the plasma plume than when focused after the plume, and it decreases with increase in the harmonic order. The optimum laser parameters and the focusing conditions to achieve good spatial coherence with high harmonic conversion have been identified, which is desirable for practical applications of the harmonic radiation.
Saut, Olivier
PROJET AURORA: COMPLEX AND HARMONIC ANALYSIS RELATED TO GENERATING SYSTEMS: PHASE SPACE LOCALIZATION PROPERTIES, SAMPLING AND APPLICATIONS The aim of the AURORA project CHARGE is to join the efforts holds: A f 2 | f, |2 B f . 1 #12;2 AURORA PROJECT CHARGE The first property is of essential
Instability of non-constant harmonic maps for the 1 + 2-dimensional equivariant wave map system
Côte, Raphaël
energy har- monic map Q (a stationary solution), and show that when it exists, Q is instable in the energy space. Our result applies in particular to the case of wave maps to the sphere S2Instability of non-constant harmonic maps for the 1 + 2-dimensional equivariant wave map system
harmonic photon. The universal cutoff in high-order har- monic generation (HHG) processes exists at Ip 3 (ponderomotive) energy of a quasifree electron quivering in the laser field in the neighborhood of the ionic core [9] and for resonance-enhanced wave mixing [10]. In contrast to these studies, in the nonperturbative
Norris, Andrew
Nonlinear shear wave interaction at a frictional interface: Energy dissipation and generation solids, brought into frictional contact by remote normal compression. A shear wave, either time har the partition of energy resulting from a time harmonic obliquely incident plane SH wave reflected and refracted
Processing simultaneous auditory objects: Infants' ability to detect mistuning in harmonic complexes
Trainor, Laurel J.
notes at the same time. However, the sound wave that reaches the ear is a composite of the sound energy components originated from one source is the har- monic relations between them. Sounds with pitch typically have energy at harmonics that are integer multiples of a fun- damental. Reflecting this, the auditory
Gentine, Pierre
Harmonic propagation of variability in surface energy balance within a coupled energy balance. The amplitude of the noise is maximum at midday when the incoming radiative forcing results in changes in the surface energy balance through the modification of outgoing radiative, turbulent
Early Draft of Introductory Chapter in a Thesis 1.1 Harmonic Generation and Fundamental Concepts
Hart, Gus
. Geometrical phase mismatch is due mainly to the Gouy shift, the phase change of which all light beams in a target material. In the presence of the strong oscillating electric field of the laser, electrons intensity for each harmonic depends on a complex interplay of several different factors, including phase
Stabilizing effect of a double-harmonic RF system in the CERN PS
Bhat, C.; /Fermilab; Caspers, F.; Damerau, H.; Hancock, S.; Mahner, E.; Zimmermann, F.; /CERN
2009-04-01T23:59:59.000Z
Motivated by the discussions on scenarios for LHC upgrades, beam studies on the stability of flat bunches in a double-harmonic RF system have been conducted in the CERN Proton Synchrotron (PS). Injecting nearly nominal LHC beam intensity per cycle, 18 bunches are accelerated on harmonic h = 21 to 26GeV with the 10MHz RF system. On the flat-top, all bunches are then transformed to flat bunches by adiabatically adding RF voltage at h = 42 from a 20 MHz cavity in anti-phase to the h = 21 system. The voltage ratio V (h42)/V (h21) of about 0.5 was set according to simulations. For the next 140 ms, longitudinal profiles show stable bunches in the double-harmonic RF bucket until extraction. Without the second harmonic component, coupled-bunch oscillations are observed. The flatness of the bunches along the batch is analyzed as a measure of the relative phase error between the RF systems due to beam loading. The results of beam dynamics simulations and their comparison with the measured data are presented.
Speech Enhancement of Noisy Speech Using Log-Spectral Amplitude Estimator and Harmonic Tunneling
Wichmann, Felix
Speech Enhancement of Noisy Speech Using Log-Spectral Amplitude Estimator and Harmonic Tunneling we present a two stage noise reduction algo- rithm for speech enhancement. The speech noise removal and decreases the performance of speech coding and speech recog- nition systems. In speech enhancement
Konofagou, Elisa E.
on the tumor's distinct stiffness at the early onset of disease. HMI is a radiation-force-based imaging method a local- ized vibration inside the target. Radiofrequency (rf) signals were then simulated using a 2D- mental rf signals to estimate the axial displacement resulting from the harmonic radiation force. In or
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experiment a...
Egedal, Jan
the high harmonic fast wave #HHFW# and energetic particles in a spherical torus #ST# #Ref. 1# is a new, Princeton, New Jersey 08543 R. W. Harvey CompX, Del Mar, California 92014 T. K. Mau University of California, Columbia University, New York, New York 10027 J. Egedal Plasma Science and Fusion Center, Massachusetts
Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids
Vasquez, Juan Carlos
Mitigation of Voltage and Current Harmonics in Grid-Connected Microgrids Mehdi Savaghebi1 , Josep M-connected microgrids. Two modes of compensation are considered, i.e. voltage and current compensation modes-electronic interface converter to the utility grid or microgrid. Microgrid is a local grid consisting of DGs, energy
PSFC/JA-04-34 Second Harmonic Operation at 460 GHz and
Griffin, Robert G.
with previous technology. Index Terms-- Gyrotron, submillimeter, harmonic, frequency tuning, dynamic nuclear Institute of Technology Cambridge, MA 02139 USA 1 Francis Bitter Magnet Laboratory Massachusetts Institute of Technology Cambridge, MA 02139 USA 2 Northrop Grumman Corporation Rolling Meadows, IL 60008 USA Submitted