Tolbert, Leon M.
had a total harmonic distortion (THD) between 75 and 100%. 480V Switchgear PPD-1 800 A PQIU Connection
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
Singh, Aarti
Sensitivity of Harmonic Injection and its Spatial Evolution for Nonlinear Distortion Suppression presents an experimental investigation of the spatial evolution and sensitivity of third-order nonlinear injection without injection (d) Output Fig. 1 Spatial evolution of the wave spectrum along the TWT axis
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...
Simões, Marcelo Godoy
. With an expectation of higher penetrations of electric vehicle chargers and renewable energy devices penetration of electric vehicle chargers on feeder level harmonic distortion. Although some of these papers
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.
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...
Felkner, L. J.; Waggoner, R. M.
1993-01-01T23:59:59.000Z
. This paper reviews the origin and causes of harmonics, the bad effects of harmonics, the acceptable harmonic distortion limits in the telecommunication power system and the best methods for harmonic detection and mitigation....
Rendusara, Dudi Abdullah
1995-01-01T23:59:59.000Z
of sensitive electronic equipment, increase in telephone interference, higher losses, etc. Recommended practices IEEE 519 and IEC 555 suggest limits on power converter generated harmonics. [3, 4]. A significant portion of adjustable speed drives... INTRODUCTION 1. 1 Introduction 1. 2 Three Phase Rectifier Interface. 1. 3 Rectifier Interface without DC-link Inductor. . . . . 1. 4 Review of Harmonic Current Cancellation Methods . 1. 5 Research Objective . 1. 6 Scope of Thesis DESIGN CONSIDERATIONS...
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
2015-06-02T23:59:59.000Z
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 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
The effects of output transformers on distortion in audio amplifiers
Lanier, Ross Edwin
1949-01-01T23:59:59.000Z
in Pig. 8. The audio frequency amplifier is a conventional single-ended, fixed bias, power amplifier using a 6?6 tube connected for triode operation and driven by a low impedance audio frequency oscillator. The amplifier was coupled to its recommended... distortion in either the primary or the output of the transformer. 52 INTZRMODUIATION DISTORTION Hewlett-Packer Audio Frequenc Oscillator odel 200 Regulate Power Supply Aud o Frequenc Am lifie rane orme under Hew e -Pac sr Harmonic lliave...
Harmonics and Resonance Issues with Wind Plants
Bradt, M. [IEEE PES Wind Plant Collector System Design Working Group; Badrzadeh, Babak [IEEE PES Wind Plant Collector System Design Working Group; Camm, E H [IEEE PES Wind Plant Collector System Design Working Group; Castillo, Nestor [IEEE PES Wind Plant Collector System Design Working Group; Mueller, David [IEEE PES Wind Plant Collector System Design Working Group; Siebert, T. [IEEE PES Wind Plant Collector System Design Working Group; Schoene, Jens [IEEE PES Wind Plant Collector System Design Working Group; Smith, Travis M [ORNL; Starke, Michael R [ORNL; Walling, R. [IEEE PES Wind Plant Collector System Design Working Group
2011-01-01T23:59:59.000Z
Wind plants are susceptible to lightly-damped resonances which can attract and amplify ambient grid harmonic distortion and magnify wind turbine harmonic generation. Long-accepted harmonic modeling assumptions and practices are not appropriate for wind plants. VSCs are not ideal current sources and grid impedance is important. Attention to modeling detail and thorough evaluation over range of conditions is critical to meaningful analysis. In general, wind turbines are very slight sources of harmonics. Most harmonic issues are a result of resonance, caused by capacitor banks (for reactive power compensation) or from the extensive underground cabling in a collector system. Converter controls instability can be exacerbated by power system resonances. In some cases this has caused severe voltage distorDon and other problems. The IEEE 519 recommended guidelines are very restrictive. I recommend that they are used to resolve serious harmonic issues, and not to create petty problems.
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.
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.; 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.
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...
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.
Performance of ECM controlled VAV fan powered terminal units
Cramlet, Andrew Charles
2009-05-15T23:59:59.000Z
(degrees) SCR Silicon Controlled Rectifier T Temperature ?T Temperature differential THD Total Harmonic Distortion VDAQ Voltage entering DAQ card Vfan Voltage entering terminal unit fan VRMS RMS value of voltage (volts) VA Volt... powered terminal unit 36 .............................................................Figure 5-2: Measured ECM series FPTU fan speed 37 ...............................Figure 5-3: Idealized voltage sine wave resulting from SCR operation 38...
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
, low total harmonic distortion + noise (THD+N) levels and simple control techniques overshadowed amplifier technology, and the next important step in designing switching audio amplifiers. It is intendedApproaches to building single-stage AC/AC conversion switch-mode audio power amplifiers Petar
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
Harmonic bundles, topological-antitopological fusion
Henri PoincarÃ© -Nancy-UniversitÃ©, UniversitÃ©
Harmonic bundles, topological-antitopological fusion and the related pluriharmonic maps Lars Sch associated to a harmonic bundle 7 1 Introduction Topological-antitopological fusion or tt -geometry
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.
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.
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.
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.
Virasoro algebra from harmonic superspace
Saidi, E.H.; Zakkari, M. (International Centre for Theoretical Physics, Trieste (Italy))
1992-07-15T23:59:59.000Z
Using harmonic superspace techniques we construct a new field realization of the Virasoro algebra. The main conformal objects are U(1) Cartan tensors instead of the U(1) Lorentz ones. The new conformal model, which admits moreover a {ital d}=2 (4,0) global supersymmetry, is constructed out of the infinitely relaxed Howe-Stelle-Townsend and Fayet-Sohnius hypermultiplets. The conformal current {ital T}{sup 4+} together with the harmonic superspace operator product expansion rules are given. The Virasoro algebra and the harmonic superspace Schwarzian derivative {ital S}{sup 4+} are also derived.
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.
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.
Image Distortions in Stereoscopic Video Systems Andrew Woods
and keystone distortion. The variation of system parameters is also analysed with the help of plots of image configurations are compared and the amount of vertical parallax induced by lens distortion and keystone
Explicit deconvolution of wellbore storage distorted well test data
Bahabanian, Olivier
2007-04-25T23:59:59.000Z
The analysis/interpretation of wellbore storage distorted pressure transient test data remains one of the most significant challenges in well test analysis. Deconvolution (i.e., the "conversion" of a variable-rate distorted pressure profile...
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
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.
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.
Harmonic generation with temporally focused ultrashort pulses
Silberberg, Yaron
Harmonic generation with temporally focused ultrashort pulses Dan Oron and Yaron Silberberg of harmonic generation with temporally focused ultrashort pulses are explored both theoreti- cally and experimentally. Analyzing the phase-matching conditions for harmonic generation we find a corre- spondence
Simple Harmonic Motion and Newton's 3rd
Yu, Jaehoon
Simple Harmonic Motion and Newton's 3rd Law Theory Simple Harmonic Motion is not as simpleperiod where m is the mass of the object in kilograms and k is the spring constant. Newton's 3rd Law Newton's 3rd Law using two Force sensors. Procedure: Simple Harmonic Motion Getting the data 1. Open
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.
Olea, Jr., Charles
2010-01-01T23:59:59.000Z
Chemical Consequences of Heme Distortion and the Role ofMatthew B. Francis Spring 2010 Chemical Consequences of Hemeby Charles Olea, Jr. Abstract Chemical Consequences of Heme
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
Visual-Feedback Distortion in a Robotic Rehabilitation
Klatzky, Roberta
INVITED P A P E R Visual-Feedback Distortion in a Robotic Rehabilitation Environment In a finger-motion rehabilitation trial, where a patient presses against robot resistance, progress can be aided by visual feedback Matsuoka ABSTRACT | We create a robotic rehabilitation environment that distorts the visual feedback
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...
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 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...
SPECTRAL APPROXIMATION OF TIME-HARMONIC MAXWELL ...
2014-10-25T23:59:59.000Z
to solve the three-dimensional time-harmonic Maxwell equations in exterior domains. We first .... Define the vector L2-space and its tangential vector space:.
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.
Current Generated Harmonics and Their Effect Upon Electrical Industrial Systems
Alexander, H. R.; Rogge, D. S.
1995-01-01T23:59:59.000Z
This paper provides a general overview of harmonics and addresses the causes of current generated harmonics in electrical systems. In addition, problems caused by current generated harmonics and their affects upon different ...
Current Generated Harmonics and Their Effect Upon Electrical Industrial Systems
Alexander, H. R.; Rogge, D. S.
This paper provides a general overview of harmonics and addresses the causes of current generated harmonics in electrical systems. In addition, problems caused by current generated harmonics and their affects upon different types of electrical...
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
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.
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...
Optical Third-Harmonic Generation in Graphene (Journal Article...
Office of Scientific and Technical Information (OSTI)
Published Article: Optical Third-Harmonic Generation in Graphene Title: Optical Third-Harmonic Generation in Graphene Authors: Hong, Sung-Young ; Dadap, Jerry I. ; Petrone,...
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.
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
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.
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.
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 Lasing Characterization at Jefferson Lab
Stephen Benson; Michelle D. Shinn
2006-08-27T23:59:59.000Z
Harmonic lasing is normally suppressed because of lasing at the fundamental wavelength. It can, however, be achieved by using any of several methods that suppress fundamental lasing. In this paper we discuss two methods used at Jefferson Lab. The first is to use the characteristics of dielectric coatings to allow harmonic lasing at cavity lengths longer than the synchronous length for the fundamental. The second is to use a dielectric coating that has little reflectivity at the fundamental. This allows us to directly compare fundamental and harmonic lasing with the same optical resonator and electron beam. We present measurement carried out at Jefferson Lab using the IR Upgrade FEL operating at 0.53, 0.94, 1.04, 1.6, and 2.8 microns in which both schemes are used to produce lasing at both the 3rd and 5th harmonic of the fundamental.
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.
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.
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.
Cascaded third harmonic generation in hybrid graphene-semiconductor waveguides
Smirnova, Daria A
2015-01-01T23:59:59.000Z
We study cascaded harmonic generation of hybrid surface plasmons in integrated planar waveguides composed of a graphene layer and a doped-semiconductor slab. We derive a comprehensive model of cascaded third harmonic generation through phase-matched nonlinear interaction of fundamental, second harmonic and third harmonic plasmonic modes supported by the structure. We show that hybrid graphene-semiconductor waveguides can simultaneously phase-match these three interacting harmonics, increasing the total third-harmonic output by a factor of 5 compared to the non-cascaded regime.
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
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
Technical Evaluation Report "COS FUV Detector Geometric Distortion Maps"
Colorado at Boulder, University of
Technical Evaluation Report "COS FUV Detector Geometric Distortion Maps" Date: November 12, 2003 Document Number: COS-11-0044 Revision: Initial Release Contract No.: NAS5-98043 CDRL No.: Prepared By: Mr. S. Beland, COS Software Engineer Date Reviewed By: Dr. E. Wilkinson, Instrument Scientist Date
A DISTORTION FREE WATERMARK FRAMEWORK FOR RELATIONAL DATABASES
Cortesi, Tino
Interpretation. Abstract: In this paper we introduce a distortion free invisible watermarking technique in pieces to parties specialized in mining it, e.g. sales patterns database, oil drilling data, financial as required in some applications. The first well-known database watermarking scheme for relational databases
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.
On the symplectic structure of harmonic superspace
Kachkachi, M.; Saidi, E.H. (Lab. de Physique Theorique, Faculte des Sciences, Av. Ibn Battota, B.P. 1014, Rabat (Morocco))
1992-11-10T23:59:59.000Z
In this paper, the symplectic properties of harmonic superspace are studied. It is shown that Diff(S[sup 2]) is isomorphic to Diff[sub 0](S[sup 3])/Ab(Diff[sub 0](S[sup 3])), where Diff[sub 0](S[sup 3]) is the group of the diffeomorphisms of S[sup 3] preserving the Cartan charge operator D[sup 0] and Ab(Diff[sub 0](S[sup 3])) is its Abelian subgroup generated by the Cartan vectors L[sub 0] = w[sup 0]D[sup 0]. The authors show also that the eigenvalue equation D[sup 0] [lambda](z) = 0 defines a symplectic structure in harmonic superspace, and the authors calculate the corresponding algebra. The general symplectic invariant coupling of the Maxwell prepotential is constructed in both flat and curved harmonic superspace. Other features are discussed.
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.
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 Analysis and Geometries of Digital Data Bases
Maggioni, Mauro
Harmonic Analysis and Geometries of Digital Data Bases AMS Session Special Sesson, 2010 () Harmonic Analysis of Data Bases January 14, 2010 1 / 41 #12;Local geometry described by a graph, Gavish) Harmonic Analysis of Data Bases January 14, 2010 2 / 41 #12;Local geometry described by a graph
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
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
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...
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.
Bayesian redshift-space distortions correction from galaxy redshift surveys
Kitaura, Francisco-Shu; Angulo, Raul E; Chuang, Chia-Hsun; Rodriguez-Torres, Sergio; Monteagudo, Carlos Hernandez; Prada, Francisco; Yepes, Gustavo
2015-01-01T23:59:59.000Z
We present a Bayesian reconstruction method which maps a galaxy distribution from redshift-space to real-space inferring the distances of the individual galaxies. The method is based on sampling density fields assuming a lognormal prior with a likelihood given by the negative binomial distribution function modelling stochastic bias. We assume a deterministic bias given by a power law relating the dark matter density field to the expected halo or galaxy field. Coherent redshift-space distortions are corrected in a Gibbs-sampling procedure by moving the galaxies from redshift-space to real-space according to the peculiar motions derived from the recovered density field using linear theory with the option to include tidal field corrections from second order Lagrangian perturbation theory. The virialised distortions are corrected by sampling candidate real-space positions (being in the neighbourhood of the observations along the line of sight), which are compatible with the bulk flow corrected redshift-space posi...
Probing correlations of early magnetic fields using ?-distortion
Ganc, Jonathan; Sloth, Martin S., E-mail: ganc@cp3.dias.sdu.dk, E-mail: sloth@cp3.dias.sdu.dk [CP"3-Origins, Center for Cosmology and Particle Physics Phenomenology, University of Southern Denmark, Campusvej 55, 5230 Odense M (Denmark)
2014-08-01T23:59:59.000Z
The damping of a non-uniform magnetic field between the redshifts of about 10{sup 4} and 10{sup 6} injects energy into the photon-baryon plasma and causes the CMB to deviate from a perfect blackbody spectrum, producing a so-called ?-distortion. We can calculate the correlation (? T) of this distortion with the temperature anisotropy T of the CMB to search for a correlation ( B{sup 2}?) between the magnetic field B and the curvature perturbation ?; knowing the ( B{sup 2}?) correlation would help us distinguish between different models of magnetogenesis. Since the perturbations which produce the ?-distortion will be much smaller scale than the relevant density perturbations, the observation of this correlation is sensitive to the squeezed limit of ( B{sup 2}?), which is naturally parameterized by b{sub NL} (a parameter defined analogously to f{sub NL}). We find that a PIXIE-like CMB experiments has a signal to noise S/N? 1.0 × b{sub NL} ( B-tilde {sub ?}/10nG){sup 2}, where B-tilde {sub ?} is the magnetic field's strength on ?-distortion scales normalized to today's redshift; thus, a 10 nG field would be detectable with b{sub NL}=O(1). However, if the field is of inflationary origin, we generically expect it to be accompanied by a curvature bispectrum (?{sup 3}) induced by the magnetic field. For sufficiently small magnetic fields, the signal ( B{sup 2} ?) will dominate, but for B-tilde {sub ?}?> 1 nG, one would have to consider the specifics of the inflationary magnetogenesis model. We also discuss the potential post-magnetogenesis sources of a ( B{sup 2}?) correlation and explain why there will be no contribution from the evolution of the magnetic field in response to the curvature perturbation.
Pulse Distortion Caused by Cylinder Diffraction and Its Impact on UWB Communications
Qiu, Robert Caiming
Pulse Distortion Caused by Cylinder Diffraction and Its Impact on UWB Communications Chenming Zhou of the characteristics of UWB signals is pulse distortion, inherently determined by its huge bandwidth. Using cylinder model as an example, pulse distortion and its impacts on UWB system performance have been investigated
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.
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.
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.
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.
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.
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...
Testing cosmological structure formation using redshift-space distortions
Will J Percival; Martin White
2008-11-11T23:59:59.000Z
Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for observing the build-up of cosmological structure. In this paper we develop and test a new statistic based on anisotropies in the measured galaxy power spectrum, which is independent of galaxy bias and matches the matter power spectrum shape on large scales. The amplitude provides a constraint on the derivative of the linear growth rate through f.sigma_8. This demonstrates that spectroscopic galaxy surveys offer many of the same advantages as weak lensing surveys, in that they both use galaxies as test particles to probe all matter in the Universe. They are complementary as redshift-space distortions probe non-relativistic velocities and therefore the temporal metric perturbations, while weak lensing tests the sum of the temporal and spatial metric perturbations. The degree to which our estimator can be pushed into the non-linear regime is considered and we show that a simple Gaussian damping model, similar to that previously used to model the behaviour of the power spectrum on very small scales, can also model the quasi-linear behaviour of our estimator. This enhances the information that can be extracted from surveys for LCDM models.
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.
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.
Harmon Electric Assn Inc | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP aCentrothermDepew, NewAl.,Hardin County, Illinois: Energy Resources JumpHarlanHarmon Electric Assn Inc
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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP aCentrothermDepew, NewAl.,Hardin County, Illinois: Energy Resources JumpHarlanHarmon Electric Assn
Efficient dynamic synchronous machine simulation with harmonics
Haskew, T.A.; Stern, H.P.; Chen, Z. [Univ. of Alabama, Tuscaloosa, AL (United States). Dept. of Electrical Engineering] [Univ. of Alabama, Tuscaloosa, AL (United States). Dept. of Electrical Engineering
1996-06-01T23:59:59.000Z
Within this paper, an efficient procedure for the dynamic simulation of faulted synchronous machines operating in the presence of harmonics is presented. The algorithm employs steady-state frequency domain techniques for simulation of the transmission system sequence networks and time domain methods for the synchronous machines represented in the odq frame of reference. The procedure affords greater accuracy than conventional fault analysis techniques based strictly on steady-state methods, yet requires far less computational time than full system dynamic simulations such as those using the EMTP.
repulsion and quantization in almost-harmonic maps, and asymptotics of the harmonic map flow
Topping, Peter
.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 Almost-harmonic maps - the proof of Theorem 1.2 13 2.1 Basic technology Topping #3; Abstract We present an analysis of bounded-energy low-tension maps between 2-spheres, we show that we can establish a `quantization estimate' which constrains the energy of the map to lie
Distorted black holes from a vacuum 5-d spherical solution
Capistrano, Abraão J S; Ulhoa, Sergio C; Amorim, Ronni G G
2015-01-01T23:59:59.000Z
We study the deformation caused by the influence of extrinsic curvature on a vacuum spherically symmetric metric embedded in a 5-d bulk. In this sense, we investigate the produced stationary black-holes and derive general properties such as its mass and horizons. As an application, a test moving particle near such black-holes is also shown as well the distortion caused by extrinsic curvature on its movement. Accordingly, using asymptotically conformal flat condition on the extrinsic curvature and an analytical expansion of a set of \\emph{n}-scalar fields, we show that the resulting black holes must be large and constrained in the range $-1/2 \\leq n \\leq 1.8$ that are locally thermodynamically stable, but not globally preferred.
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.
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
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
Enhancing tidal harmonic analysis: Robust (hybrid L1 ) solutions
Hickey, Barbara
Enhancing tidal harmonic analysis: Robust (hybrid L1 =L2 ) solutions Keith E. Leffler Ã, David A 24 February 2008 Accepted 28 April 2008 Keywords: Tides Tidal analysis Harmonic analysis Robust is calculated from the power spectrum of the residual, a calculation that filters broad spectrum noise
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...
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
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
SLOS242D -SEPTEMBER 2002 -REVISED JANUARY 2004 2 GHz, LOW DISTORTION, CURRENT FEEDBACK AMPLIFIERS
Berns, Hans-Gerd
PAD packages. RELATED DEVICES AND DESCRIPTIONS THS3001 ±15-V 420-MHz Low Distortion CFB Amplifier THS3061/2 ±15-V 300-MHz Low Distortion CFB Amplifier THS3122 ±15-V Dual CFB Amplifier With 350 mA Drive THS4271
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
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
Wehlau, David
: source coding, rate distortion theory, quantization. \\Lambda A. GyÂ¨orgy is with the Faculty of Electrical, Ontario, Canada K7L 3N6 (email: linder@mast.queensu.ca). K. Zeger is with the Department of ElectricalOn the RateÂDistortion Function of Random Vectors and Stationary Sources with Mixed Distributions
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
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
Coding into a source: an inverse rate-distortion Anant Sahai
California at Berkeley, University of
Sahai (UC Berkeley) Inverse Rate Distortion Sep 27, 2006 1 / 27 #12;Suppose the aliens landed. . . Your Distortion Sep 27, 2006 2 / 27 #12;Suppose the aliens landed. . . Your mission: reverse 27, 2006 2 / 27 #12;Suppose the aliens landed. . . Your mission: reverse
Calibration of a Saccadic Camera System to Adapt to Lens Distortions
Hornsey, Richard
" is an electronic image sensor used in multiple modes of resolution. We use a subwindow set at high resolution an empirical distortion model of the image formation process. This allows the saccadic camera to dynamically, to compensate for low acuity, distorted, or occluded visual data. Jakobson reported on studies of a subject
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.
Spectral distortions in the cosmic microwave background polarization
Renaux-Petel, Sébastien [Laboratoire de Physique Théorique et Hautes Energies, Université Pierre and Marie Curie - Paris VI, CNRS-UMR 7589, 4 place Jussieu, Paris, 75252 (France); Fidler, Christian [Institute of Cosmology and Gravitation, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Pitrou, Cyril [Sorbonne Universités, Institut Lagrange de Paris, 98 bis Bd Arago, Paris, 75014 (France); Pettinari, Guido W., E-mail: srenaux@lpthe.jussieu.fr, E-mail: christian.fidler@port.ac.uk, E-mail: pitrou@iap.fr, E-mail: g.pettinari@sussex.ac.uk [Department of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH (United Kingdom)
2014-03-01T23:59:59.000Z
We compute the spectral distortions of the Cosmic Microwave Background (CMB) polarization induced by non-linear effects in the Compton interactions between CMB photons and the flow of intergalactic electrons. This signal is of the y-type and is dominated by contributions arising from the reionized era. We stress that it is not shadowed by the thermal SZ effect which has no equivalent for polarization. We decompose its angular dependence into E- and B-modes, and we calculate the corresponding power spectra, both exactly and using a suitable Limber approximation that allows a simpler numerical evaluation. We find that B-modes are of the same order of magnitude as E-modes. Both spectra are relatively flat, peaking around ? = 280, and their overall amplitude is directly related to the optical depth to reionization. Moreover, we find this effect to be one order of magnitude larger than the non-linear kinetic Sunyaev-Zel'dovich effect in galaxy clusters. Finally, we discuss how to improve the detectability of our signal by cross-correlating it with other quantities sourced by the flow of intergalactic electrons.
The Globally Harmonized System for Hazard Communication (GHS)
Capogna, Luca
The Globally Harmonized System for Hazard Communication (GHS) University of Arkansas Facilities groups. · GHS is based on major existing systems around the world, including OSHA's Hazard Communication to hazard communication, providing agreed upon criteria for classification of chemical hazards
Variable Frequency Motor Drives: Harmonics, Power Factor, and Energy Efficiency
Massey, G. W.
of inductance in Henries. Impedance due to inductive reactance increases with frequency, which tends to damp higher order harmonics. Meanwhile, capacitive reactance decreases in proportion to frequency as given by: X= 1 (7) c 21tfC where Xc...
Adaptive Control of Third Harmonic Generation via Genetic Algorithm
Hua, Xia
2010-10-12T23:59:59.000Z
. We use genetic algorithm to optimize third harmonic generation (THG), and investigate various pulse shaper options. We test our setup by running the experiment with varied initial conditions and study factors that affect convergence of the algorithm...
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
Conversion efficiency, scaling and global optimization of high harmonic generation
Falcao-Filho, Edilson L.
Closed form expressions for the high harmonic generation (HHG) conversion efficiency in the plateau and cut-off region are derived showing agreement with previous observations. Application of these results to optimal ...
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
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.
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.
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.
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 lattice behavior of two-dimensional colloidal crystals
P. Keim; G. Maret; U. Herz; H. H. von Grünberg
2004-02-17T23:59:59.000Z
Using positional data from video-microscopy and applying the equipartition theorem for harmonic Hamiltonians, we determine the wave-vector-dependent normal mode spring constants of a two-dimensional colloidal model crystal and compare the measured band-structure to predictions of the harmonic lattice theory. We find good agreement for both the transversal and the longitudinal mode. For $q\\to 0$, the measured spring constants are consistent with the elastic moduli of the crystal.
Rendusara, Dudi Abdullah
1995-01-01T23:59:59.000Z
of positive and negative sequence balanced voltage sources . 21 19 Output voltage V, 20 Twelve pulse rectifier system connected in parallel 22 26 Page 21 Effects of input voltage unbalance in a twelve pulse diode rectifier system connected in parallel... one bridge to have more current stress than the other. Fig. 22 shows the current sharing between the diode rectifier bridges. We can see that the output current Ia, is more than twice the output current Id, . This drastic mismatch in current...
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.
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
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 ...
Reynolds and Favre-averaged rapid distortion theory for compressible, ideal-gas turbulence
Lavin, Tucker Alan
2007-09-17T23:59:59.000Z
Compressible ideal-gas turbulence subjected to homogeneous shear is investigated at the rapid distortion limit. Specific issues addressed are (i) the interaction between kinetic and internal energies and role of ...
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.
Gutierrez, Luis F.; Ozturk, Cengizhan; McVeigh, Elliot R.; Lederman, Robert J. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 and Lab of Cardiac Energetics, National Institutes of Health, Bethesda, Maryland 20892 (United States); Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892 and Biomedical Engineering Institute, Bogazici University, Istanbul (Turkey); Lab of Cardiac Energetics, National Institutes of Health, Bethesda, Maryland 20892 and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Cardiovascular Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892 (United States)
2008-03-15T23:59:59.000Z
X-ray images acquired on systems with image intensifiers (II) exhibit characteristic distortion which is due to both external and internal factors. The distortion is dependent on the orientation of the II, a fact particularly relevant to II's mounted on C arms which have several degrees of freedom of motion. Previous descriptions of distortion correction strategies have relied on a dense sampling of the C-arm orientation space, and as such have been limited mostly to a single arc of the primary angle, {alpha}. We present a new method which smooths the trajectories of the segmented vertices of the grid phantom as a function of {alpha} prior to solving the two-dimensional warping problem. It also shows that the same residual errors of distortion correction could be achieved without fitting the trajectories of the grid vertices, but instead applying the previously described global method of distortion correction, followed by directly smoothing the values of the polynomial coefficients as functions of the C-arm orientation parameters. When this technique was applied to a series of test images at arbitrary {alpha}, the root-mean-square (RMS) residual error was 0.22 pixels. The new method was extended to three degrees of freedom of the C-arm motion: the primary angle, {alpha}; the secondary angle, {beta}; and the source-to-intensifier distance, {lambda}. Only 75 images were used to characterize the distortion for the following ranges: {alpha}, {+-}45 deg. ({delta}{alpha}=22.5 deg.); {beta}, {+-}36 deg. ({delta}{beta}=18 deg.); {lambda}, 98-118 cm ({delta}{lambda}=10 cm). When evaluated on a series of test images acquired at arbitrary ({alpha},{beta},{lambda}), the RMS residual error was 0.33 pixels. This method is targeted at applications such as guidance of catheter-based interventions and treatment planning for brachytherapy, which require distortion-corrected images over a large range of C-arm orientations.
Flow harmonics within an analytically solvable viscous hydrodynamic model
Yoshitaka Hatta; Jorge Noronha; Giorgio Torrieri; Bo-Wen Xiao
2014-10-01T23:59:59.000Z
Based on a viscous hydrodynamic model with anisotropically perturbed Gubser flow and isothermal Cooper-Frye freezeout at early times, we analytically compute the flow harmonics $v_n(p_T)$ and study how they scale with the harmonic number $n$ and transverse momentum, as well as the system size, shear and bulk viscosity coefficients, and collision energy. In particular, we find that the magnitude of shear viscous corrections grows linearly with $n$. The mixing between different harmonics is also discussed. While this model is rather simple as compared to realistic heavy-ion collisions, we argue that the scaling results presented here may be meaningfully compared to experimental data collected over many energies, system sizes, and geometries.
Second-harmonic generation from hyperbolic plasmonic nanorod metamaterial slab
Marino, Giuseppe; Krasavin, Alexey V; Ginzburg, Pavel; Olivier, Nicolas; Wurtz, Gregory A; Zayats, Anatoly V
2015-01-01T23:59:59.000Z
Hyperbolic plasmonic metamaterials provide numerous opportunities for designing unusual linear and nonlinear optical properties. We show that the modal overlap of fundamental and second-harmonic light in an anisotropic plasmonic metamaterial slab results in the broadband enhancement of radiated second-harmonic intensity by up to 2 and 11 orders of magnitudes for TM- and TE-polarized fundamental light, respectively, compared to a smooth Au film under TM-polarised illumination. The results open up possibilities to design tuneable frequency-doubling metamaterial with the goal to overcome limitations associated with classical phase matching conditions in thick nonlinear crystals.
The progress in developing superconducting third harmonic cavity
Solyak, Nikolay; Edwards, Helen; Foley, Mike; Gonin, Ivan; Harms, Elvin; Khabiboulline, Timergali; Mitchell, Donald; Olis, Daniel; Rowe, Allan; /Fermilab
2006-06-01T23:59:59.000Z
The XFEL and TTF facilities are planning to use section with a few third harmonic cavities (3.9GHz) upstream of the bunch compressor to improve beam performance [1-2]. Fermilab is developing superconducting third harmonic section for the TTFII upgrade. This section will include four cavities equipped with couplers and blade tuners installed in cryostat. Up to now, two cavities are complete and one of them is under test. The status of the cavity development and preliminary test results are presented in this paper.
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.
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...
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 ...
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...
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
Second harmonic electromagnetic emission via Langmuir wave coalescence
Melrose, Don
S of the pri- mary Langmuir waves L into product Langmuir waves L and ion-sound waves S. The kinematic of Langmuir waves at low wavenumbers. The number of such repeated backscatter decays is limited by kinematic upsteam of the Earth's bowshock.1315 An alternative mechanism to produce fundamental and harmonic
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
High harmonic generation and attosecond pulse production in dense medium
Becker, Andreas
, Russia 3M.V.Lomonosov Moscow State University, Physics Department, Vorob'evy Gory, 119992 Moscow, Russia ABSTRACT We have studied the high harmonic generation and attosecond pulse production in a plasma or gas sr. 38, 119991 Moscow, Russia 3M.V.Lomonosov Moscow State University, Physics Department, Vorob
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:...
Master / PhD Project Resonatorassisted high harmonic generation
Hänsch, Theodor W.
Master / PhD Project Resonatorassisted high harmonic generation with spatially tailored driving+ at low temperatures and on the generation and charac terization of an XUV frequency comb source suitable comb experiments: The XUV frequency comb is generated through extremely nonlinear conversion (high
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.
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.
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
Thermal Conductivity for a Noisy Disordered Harmonic Chain
Cedric Bernardin
2008-08-05T23:59:59.000Z
We consider a $d$-dimensional disordered harmonic chain (DHC) perturbed by an energy conservative noise. We obtain uniform in the volume upper and lower bounds for the thermal conductivity defined through the Green-Kubo formula. These bounds indicate a positive finite conductivity. We prove also that the infinite volume homogenized Green-Kubo formula converges.
Theory of second-harmonic generation in colloidal crystals
Jian, Y C; Huang, J P
2006-01-01T23:59:59.000Z
We study the effective susceptibility of second-harmonic generation (SHG) in colloidal crystals considering the local lattice effect using Edward-Kornfeld formulation, which are made of graded metallodielectric nanoparticles with optical nonlinearity suspended in a host fluid. We find a large enhancement and redshift of optical nonlinearity, which arises from the periodic structure, local field effects and gradation in the metallic cores.
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
A computational introduction to quantum statistics using harmonically trapped particles
Ligare, Martin
and multiplicities. The examples illustrate the effect of quantum statistics on the sharing of energy between weaklyA computational introduction to quantum statistics using harmonically trapped particles Martin the statistical definition of entropy and the second law of thermodynamics [Am. J. Phys. 65, 26 (1997)]. I
Energy transport by acoustic modes of harmonic Lisa Harris
Theil, Florian
Energy transport by acoustic modes of harmonic lattices Lisa Harris , Jani Lukkarinen , Stefan vector, k = 0. To derive equations that describe the macroscopic energy transport we introduce the Wigner concentrating to k = 0. A simple consequence of our result is the complete characterization of energy transport
Response of turbulent premixed flames to harmonic acoustic forcing
Lieuwen, Timothy C.
for land- based gas turbines, future aircraft engines, industrial heaters and boilers rely on premixed 1540 2006 The Combustion Institute. Published by Elsevier Inc. All rights reserved. Keywords: Flame area to a harmonic disturbance of given amplitude depends upon turbulence intensity. Low emissions combustion systems
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.
Coulomb distortion in high-Q^2 elastic e-p scattering
John Arrington; Ingo Sick
2004-06-11T23:59:59.000Z
Recently, there has been a significant amount of activity to try and understand the discrepancy between Rosenbluth and polarization transfer measurements of the proton form factors. It has been suggested that the standard use of plane-wave Born approximation in extracting the form factors is insufficient, and that higher-order terms must also be included. Of the corrections missing in standard prescriptions, Coulomb distortion is the most well understood. In this paper, we examine the effect of Coulomb distortion on the extraction of the proton form factors.
A model for the Pockels effect in distorted liquid crystal blue phases
F. Castles
2015-07-29T23:59:59.000Z
Recent experiments have found that a mechanically distorted blue phase can exhibit a primary linear electro-optic (Pockels) effect [F. Castles \\textit{et al}. Nature Mater. \\textbf{13}, 817 (2014)]. Here it is shown that flexoelectricity can account for the experimental results and a model, which is based on continuum theory but takes account of the sub-unit-cell structure, is proposed. The model provides a quantitative description of the effect accurate to the nearest order of magnitude and predicts that the Pockels coefficient(s) in an optimally-distorted blue phase may be two orders of magnitude larger than in lithium niobate.
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...
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
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
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 operate in the low-gain FEL regime. Harmonic cascades have been designed for each pass of analytical models which predict FEL performance. We discuss lattice considerations perti- nent for harmonic
Fast Harmonic Balance of SIS Mixers with Multiple Junctions and Superconducting Circuits
Ward, John
Fast Harmonic Balance of SIS Mixers with Multiple Junctions and Superconducting Circuits Frank Rice-47, Pasadena, CA 91125, USA. Abstract We have extended the spectral domain harmonic balance method- eling. Consequently such software must include a fast and accurate harmonic balance method. The small
Bak, Claus Leth
Aalborg Universitet Harmonic Resonances in Wind Power Plants: Modeling, Analysis and Active. (2015). Harmonic Resonances in Wind Power Plants: Modeling, Analysis and Active Mitigation Methods from vbn.aau.dk on: juli 04, 2015 #12;Harmonic Resonances in Wind Power Plants: Modeling, Analysis
Energy transport by acoustic modes of harmonic lattices Lisa Harris # , Jani Lukkarinen + , Stefan of energy transport in harmonic lattices with acoustic dispersion relations. 1 Introduction. The energy, we first need to understand how energy is transported within the crystal via purely harmonic
Kaur, Sukhdeep; Sharma, A. K. [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016 (India); Salih, Hyder A. [Department of Applied Sciences, University of Baghdad, Baghdad (Iraq)
2009-04-15T23:59:59.000Z
Second harmonic generation of a right circularly polarized Gaussian electromagnetic beam in a magnetized plasma is investigated. The beam causes Ohmic heating of electrons and subsequent redistribution of the plasma, leading to self-defocusing. The radial density gradient, in conjunction with the oscillatory electron velocity, produces density oscillation at the wave frequency. The density oscillation beats with the oscillatory velocity to produce second harmonic current density, giving rise to resonant second harmonic radiation when the wave frequency is one-third of electron cyclotron frequency. The second harmonic field has azimuthal dependence as exp(i{theta}). The self-defocusing causes a reduction in the efficiency of harmonic generation.
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
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
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
Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer
Peltier, Scott Jacob
2013-08-05T23:59:59.000Z
High-resolution particle image velocimetry (PIV) is employed to resolve the velocity fields within a Mach 4.9 mechanically distorted turbulent boundary layer (Re? ? 40,000). The goal of this study is to directly observe the mechanisms responsible...
Reducing pulse distortion in fast-light pulse propagation through an erbium-doped
Boyd, Robert W.
Reducing pulse distortion in fast-light pulse propagation through an erbium-doped fiber amplifier, 2007 (Doc. ID 78405); published March 19, 2007 When a pulse superposed on a cw background propagates through an erbium-doped fiber amplifier with a negative group velocity, either pulse broadening or pulse
PREDICTION OF HEAT TREATMENT DISTORTION OF CAST STEEL C-RINGS
Beckermann, Christoph
Engineering, The University of Iowa, Iowa City, Iowa 52242, USA Abstract Navy C-Ring test parts were made the commercial heat treatment distortion simulation software DANTE. The parts were machined and then measured trends toward closure are still apparent. This is in contrast to results shown in previous literature
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
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
Optimum bit-by-bit power allocation for minimum distortion transmission
Karaer, Arzu
2007-04-25T23:59:59.000Z
In this thesis, bit-by-bit power allocation in order to minimize mean-squared error (MSE) distortion of a basic communication system is studied. This communication system consists of a quantizer. There may or may not be a channel encoder and a...
Radar transponder operation with compensation for distortion due to amplitude modulation
Ormesher, Richard C. (Albuquerque, NM); Tise, Bertice L. (Albuquerque, NM); Axline, Jr., Robert M. (Albuquerque, NM)
2011-01-04T23:59:59.000Z
In radar transponder operation, a variably delayed gating signal is used to gate a received radar pulse and thereby produce a corresponding gated radar pulse for transmission back to the source of the received radar pulse. This compensates for signal distortion due to amplitude modulation on the retransmitted pulse.
Exact distorted-wave approach to multiple-scattering theory for general potentials
D. L. Foulis
2008-06-03T23:59:59.000Z
We present a new approach to real-space multiple-scattering theory for molecules and clusters, based on the two-potential (distorted-wave) Lippmann-Schwinger equation formalism. Our approach uses a recently developed form [D. L. Foulis, Phys. Rev. A70, 022706 (2004)], for the partial-wave expansions of the exact time-independent single-particle Green function for a general potential, to solve exactly the scattering problem for the distorting potential. The multiple-scattering problem for the full multicenter molecular potential is then developed along familiar lines, within a partition of space consisting of non-overlapping atomic spheres, but relative to the distorting potential. To achieve this some new general Green-function re-expansion formulas are derived, as well as further developments of our earlier partial-wave expansions. Based on the division of the multicenter molecular potential into the non-singular distorting potential and a remaining singular part we develop explicitly the secular equations of our approach and prove a result concerning the symmetry of the atomic matrices. The new secular equations are similar in overall form to those of related methods, requiring coupled radial Schr\\"odinger-equation solutions for each atomic center, together with atomic-sphere surface integrals, but no volume integrals. We treat both continuum (scattering) states and bound states within the same framework, and consider also the case of an outer sphere.
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.
Jones, Alan G.
J. Geomag. Geoelectr., 49, 767-789, 1997 Electric and Magnetic Field Galvanic Distortion importance for many of the BC87 sites. However, even a combined electric and magnetic field galvanic-inductive (usually called galvanic) distortion of the electric andjor magnetic fields. Relevant studies include
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
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
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
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 harmonics generation in relativistic electron beam with virtual cathode
Kurkin, S. A., E-mail: KurkinSA@gmail.com; Badarin, A. A.; Koronovskii, A. A.; Hramov, A. E. [Saratov State Technical University, Politechnicheskaja 77, Saratov 410028, Russia and Saratov State University, Astrakhanskaja 83, Saratov 410012 (Russian Federation)
2014-09-15T23:59:59.000Z
The study of the microwave generation regimes with intense higher harmonics taking place in a high-power vircator consisting of a relativistic electron beam with a virtual cathode has been made. The characteristics of these regimes, in particular, the typical spectra and their variations with the change of the system parameters (beam current, the induction of external magnetic field) as well as physical processes occurring in the system have been analyzed by means of 3D electromagnetic simulation. It has been shown that the system under study demonstrates the tendency to the sufficient growth of the amplitudes of higher harmonics in the spectrum of current oscillations in the VC region with the increase of beam current. The obtained results allow us to consider virtual cathode oscillators as promising high power mmw-to-THz sources.
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.
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.
Single-shot fluctuations in waveguided high-harmonic generation
Goh, S J; van der Slot, P J M; Bastiaens, H J M; Herek, J; Biedron, S G; Danailov, M B; Milton, S V; Boller, K -J
2015-01-01T23:59:59.000Z
For exploring the application potential of coherent soft x-ray (SXR) and extreme ultraviolet radiation (XUV) provided by high-harmonic generation, it is important to characterize the central output parameters. Of specific importance are pulse-to-pulse (shot-to-shot) fluctuations of the high-harmonic output energy, fluctuations of the direction of the emission (pointing instabilities), and fluctuations of the beam divergence and shape that reduce the spatial coherence. We present the first single-shot measurements of waveguided high-harmonic generation in a waveguided (capillary-based) geometry. Using a capillary waveguide filled with Argon gas as the nonlinear medium, we provide the first characterization of shot-to-shot fluctuations of the pulse energy, of the divergence and of the beam pointing. We record the strength of these fluctuations vs. two basic input parameters, which are the drive laser pulse energy and the gas pressure in the capillary waveguide. In correlation measurements between single-shot dr...
Aws, Ghassan
Postural distortion of human bite marks on skin occurs when photographing a bite mark in a body position other than the position of the body at the time of biting. Postural distortion in the bite mark may introduce ...
Testing for dynamical dark energy models with redshift-space distortions
Tsujikawa, Shinji [Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Felice, Antonio De [ThEP's CRL, NEP, The Institute for Fundamental Study, Naresuan University, Phitsanulok 65000 (Thailand); Alcaniz, Jailson, E-mail: shinji@rs.kagu.tus.ac.jp, E-mail: antoniod@nu.ac.th, E-mail: alcaniz@on.br [Departamento de Astronomia, Observatório Nacional, 20921-400 Rio de Janeiro - RJ (Brazil)
2013-01-01T23:59:59.000Z
The red-shift space distortions in the galaxy power spectrum can be used to measure the growth rate of matter density perturbations ?{sub m}. For dynamical dark energy models in General Relativity we provide a convenient analytic formula of f(z)?{sub 8}(z) written as a function of the redshift z, where f = dln ?{sub m}/dln a (a is the cosmological scale factor) and ?{sub 8} is the rms amplitude of over-density at the scale 8 h{sup ?1} Mpc. Our formula can be applied to the models of imperfect fluids, quintessence, and k-essence, provided that the dark energy equation of state w does not vary significantly and that the sound speed is not much smaller than 1. We also place observational constraints on dark energy models of constant w and tracking quintessence from the recent data of red-shift space 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.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gilbert, Dustin A.; Ye, Li; Varea, Aïda; Agramunt-Puig, Sebastià; del Valle, Nuria; Navau, Carles; López-Barbera, José Francisco; Buchanan, Kristen S.; Hoffmann, Axel; Sánchez, Alvar; et al
2015-04-28T23:59:59.000Z
Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting potential applications. In addition, the exchange coupling of magnetic vortices to antiferromagnets has also been shown to lead to a range of novel phenomena and functionalities. Here we report a new magnetization reversal mode of magnetic vortices in exchange coupled Ir20Mn80/Fe20Ni80 microdots: distorted viscous vortex reversal. In contrast to the previously known or proposed reversal modes, the vortex is distorted close to the interface and viscously dragged due to the uncompensated spins of a thin antiferromagnet, which leads to unexpectedmore »asymmetries in the annihilation and nucleation fields. These results provide a deeper understanding of the physics of exchange coupled vortices and may also have important implications for applications involving exchange coupled nanostructures.« less
R. Haeusler; A. F. Badea; H. Rebel; I. M. Brancus; J. Oehlschlaeger
2001-10-17T23:59:59.000Z
Event-by-event measured arrival time distributions of Extensive Air Shower (EAS) muons are affected and distorted by various interrelated effects which originate from the time resolution of the timing detectors, from fluctuations of the reference time and the number (multiplicity) of detected muons spanning the arrival time distribution of the individual EAS events. The origin of these effects is discussed, and different correction procedures, which involve detailed simulations, are proposed and illustrated. The discussed distortions are relevant for relatively small observation distances (R < 200 m) from the EAS core. Their significance decreases with increasing observation distance and increasing primary energies. Local arrival time distributions which refer to the observed arrival time of the first local muon prove to be less sensitive to the mass of the primary. This feature points to the necessity of arrival time measurements with additional information on the curvature of the EAS disk.
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.
Transverse distortion of a relativistic composite system in impact parameter space
Narinder Kumar; Harleen Dahiya
2015-02-04T23:59:59.000Z
We investigate the Generalized Parton Distributions (GPDs) in impact parameter space using the explicit light front wave functions (LFWFs) for the two-particle Fock state of the electron in QED. The Fourier transform (FT) of the GPDs gives the distribution of quarks in the transverse plane for zero longitudinal momentum transfer ($\\xi=0$). We study the relationship of the spin flip GPD $E(x,0,-\\vec{\\Delta}_\\perp^2)$ with the distortion of unpolarized quark distribution in the transverse plane when the target nucleon is transversely polarized and also determine the sign of distortion from the sign of anomalous magnetic moment. To verify the sign of distortion, we also compute it directly from the LFWFs by performing a FT in position space coordinate $\\vec{f}_\\perp$. The explicit relation between the deformation in the two spaces can also be obtained using the convolution integrals. To show the relation of the model LFWFs to a realistic model of nucleon physics, we have designed a specific weight function of our model LFWFs and integrated it over the mass parameter. Also we have simulated the form factor of the nucleon in the AdS/QCD holographic LFWFs model and studied the power-law behaviour at short distances.
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...
Neuhoff, Karsten; Keats, Kim; Sato, Misato
cycle gas turbine) 473 Hydro (pumped storage or pondage hydro); 0 Diesel generator 947 Nuclear 0 Renewables 0 Conventional coal boiler 2,840 Conventional steam turbine (burning fossil fuel other than coal) 1,420 Table 1 Assumed Initial Allocation... due to the heterogeneity among allocation methods adopted across Europe. The theoretical arguments for harmonization are strong (Ãhman et al. 2006). Under the current system where some discretion over NAPs is retained by each MS, we expect...
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.
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.
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.
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)
Generalized energy equipartition in harmonic oscillators driven by active baths
Claudio Maggi; Matteo Paoluzzi; Nicola Pellicciotta; Alessia Lepore; Luca Angelani; Roberto Di Leonardo
2015-06-26T23:59:59.000Z
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.
Thermal conductivity in harmonic lattices with random collisions
Giada Basile; Cédric Bernardin; Milton Jara; Tomasz Komorowski; Stefano Olla
2015-09-08T23:59:59.000Z
We review recent rigorous mathematical results about the macroscopic behaviour of harmonic chains with the dynamics perturbed by a random exchange of velocities between nearest neighbor particles. The random exchange models the effects of nonlinearities of anharmonic chains and the resulting dynamics have similar macroscopic behaviour. In particular there is a superdiffusion of energy for unpinned acoustic chains. The corresponding evolution of the temperature profile is governed by a fractional heat equation. In non-acoustic chains we have normal diffusivity, even if momentum is conserved.
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.
Background and Reflections on the Life Cycle Assessment Harmonization Project
Broader source: Energy.gov [DOE]
Despite the ever-growing body of life cycle assessment 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.
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. ...
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.
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 ...
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
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
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.
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
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experimenta...
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experimenta... A; published online 23 April 2004 Ion absorption of the high harmonic fast wave in a spherical torus Y.-K. M power are injected into the plasma simultaneously, a fast ion population with energy above the beam
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experiment a...
Egedal, Jan
Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experiment a; published online 23 April 2004# Ion absorption of the high harmonic fast wave in a spherical torus #Y.K. M neutral beam and rf power are injected into the plasma simultaneously, a fast ion population with energy
Magnetic Lossess Simulation in PM SM Drive by FE: Harmonic Superposition by Method of Locked Rotor
Paris-Sud XI, Université de
as essentially radial flux devices with stray flux in the end windings being negligibly small [1] then the 2D and harmonic MMF rotating around it. Actual machine being designed with quasi sinusoidal winding distribution for superposition to work, we start with harmonic fields' analysis in stator and in rotor reference frame. II
ZAGIER-TYPE DUALITIES AND LIFTING MAPS FOR HARMONIC MAASS-JACOBI FORMS
Bringmann, Kathrin
ZAGIER-TYPE DUALITIES AND LIFTING MAPS FOR HARMONIC MAASS-JACOBI FORMS KATHRIN BRINGMANN AND OLAV K. RICHTER Abstract. The real-analytic Jacobi forms of Zwegers' Ph.D. thesis play an important role. In this paper, we introduce harmonic Maass-Jacobi forms, which include the classical Jacobi forms as well
Optical second-harmonic generation selection rules and resonances in buried oxide interfaces
Marrucci, Lorenzo
Optical second-harmonic generation selection rules and resonances in buried oxide interfaces-two-dimensional electron gas at the interface between the band insulators LaAlO3 and SrTiO3 is still not fully understood. Interface- sensitive optical second-harmonic spectroscopy can shed light on this mechanism, by accessing
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
Circular Harmonic Decomposition Approach for Numerical Inversion of Circular Radon Transforms
Louis, Alfred K.
Circular Harmonic Decomposition Approach for Numerical Inversion of Circular Radon Transforms Gaël@num.uni-sb.de ABSTRACT Numerical inversions via circular harmonic decomposition for two classes of circular Radon transforms are established. The first class deals with the Radon transform (RT) de- fined on circular arcs
EXPONENTIAL RADON TRANSFORM INVERSION BASED ON HARMONIC ANALYSIS OF THE EUCLIDEAN MOTION GROUP
Yazici, Birsen
EXPONENTIAL RADON TRANSFORM INVERSION BASED ON HARMONIC ANALYSIS OF THE EUCLIDEAN MOTION GROUP Can Engineering Troy, NY ABSTRACT This paper presents a new method for the exponential Radon trans- form inversion based on harmonic analysis of the Euclidean mo- tion group (M(2)). The exponential Radon transform
RADON TRANSFORM INVERSION BASED ON HARMONIC ANALYSIS OF THE EUCLIDEAN MOTION GROUP
Yazici, Birsen
RADON TRANSFORM INVERSION BASED ON HARMONIC ANALYSIS OF THE EUCLIDEAN MOTION GROUP Can Evren Yarman of the projection slice theorem using harmonic analysis of the Euclidean motion group (M(N)). The Radon transform to new algo- rithms for the inversion of the Radon transform. 1. INTRODUCTION The Radon transform forms
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
Moiseyev, Nimrod
2006 We analyze the dynamical symmetries and the selection rules relevant to the process of production of high-order harmonics as a result of irradiating an atom with strong, continuous bichromatic laser spectrum of harmonics could be a source for the production of attosecond light pulses. We demonstrate our
Rowe, Anthony
Rate-Harmonized Scheduling for Saving Energy Anthony Rowe Karthik Lakshmanan Haifeng Zhu Ragunathan mode, substantially more energy savings can be obtained but it requires a significant amount of time such that processor idle times are lumped together. We next introduce the Energy-Saving Rate-Harmonized Scheduler
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
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.
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.
Behavior of Turbulent Structures within a Mach 5 Mechanically Distorted Boundary Layer
Peltier, Scott Jacob
2013-08-05T23:59:59.000Z
stream_source_info PELTIER-DISSERTATION-2013.pdf.txt stream_content_type text/plain stream_size 560918 Content-Encoding ISO-8859-1 stream_name PELTIER-DISSERTATION-2013.pdf.txt Content-Type text/plain; charset=ISO-8859...-1 BEHAVIOR OF TURBULENT STRUCTURES WITHIN A MACH 5 MECHANICALLY DISTORTED BOUNDARY LAYER A Dissertation by SCOTT JACOB PELTIER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements...
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.
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
Deuterium Beam Acceleration with 3rd Harmonic ICRH in Joint European Torus: Sawtooth Stabilization and Alfvén Eigenmodes
Exact energy distribution function in time-dependent harmonic oscillator
Marko Robnik; Valery G. Romanovski; Hans-Juergen Stoeckmann
2006-08-11T23:59:59.000Z
Following a recent work by Robnik and Romanovski (J.Phys.A: Math.Gen. {\\bf 39} (2006) L35, Open Syst. & Infor. Dyn. {\\bf 13} (2006) 197-222) we derive the explicit formula for the universal distribution function of the final energies in a time-dependent 1D harmonic oscillator, whose functional form does not depend on the details of the frequency $\\omega (t)$, and is closely related to the conservation of the adiabatic invariant. The normalized distribution function is $P(x) = \\pi^{-1} (2\\mu^2 - x^2)^{-{1/2}}$, where $x=E_1- \\bar{E_1}$, $E_1$ is the final energy, $\\bar{E_1}$ is its average value, and $\\mu^2$ is the variance of $E_1$. $\\bar{E_1}$ and $\\mu^2$ can be calculated exactly using the WKB approach to all orders.
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.
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.
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.
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.
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.
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...
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.
Disentangling redshift-space distortions and nonlinear bias using the 2D power spectrum
Jennings, Elise
2015-01-01T23:59:59.000Z
We present the nonlinear 2D galaxy power spectrum, $P(k,\\mu)$, in redshift space, measured from the Dark Sky simulations, using galaxy catalogs constructed with both halo occupation distribution and subhalo abundance matching methods, chosen to represent an intermediate redshift sample of luminous red galaxies. We find that the information content in individual $\\mu$ (cosine of the angle to the line of sight) bins is substantially richer then multipole moments, and show that this can be used to isolate the impact of nonlinear growth and redshift space distortion (RSD) effects. Using the $\\muextract the nonlinear bias successfully removes a large parameter degeneracy when constraining the linear growth rate of structure. We carry out a joint parameter estimation, using the low $\\mu$ simulation data to ...
Chu, Shih-I
Generation and coherent control of even-order harmonics driven by intense frequency-comb and cavity) doi:10.1088/0953-4075/46/14/145403 Generation and coherent control of even-order harmonics driven, resulting in the generation of even-order harmonics. The high-order harmonic generation (HHG) from a two
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
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.
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.
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.
Generation of Ultra-intense Gamma-ray Train by QED Harmonics
Liu, Chen; Zhang, Xiaomei; Ji, Liangliang; Wang, Wenpeng; Xu, Jiancai; Zhao, Xueyan; Yi, Longqing; Shi, Yin; Zhang, Lingang; Xu, Tongjun; Pei, Zhikun; Xu, Zhizhan
2015-01-01T23:59:59.000Z
When laser intensity exceeds 10^22W/cm^2, photons with energy above MeV can be generated from high-order harmonics process in the laser-plasma interaction. We find that under such laser intensity, QED effect plays a dominating role in the radiation pattern. Contrast to the gas and relativistic HHG processes, both the occurrence and energy of gamma-ray emission produced by QED harmonics are random and QED harmonics are usually not coherent, while the property of high intensity and ultra-short duration is conserved. Our simulation shows that the period of gamma-ray train is half of the laser period and the peak intensity is 1.4e22W/cm^2. This new harmonic production with QED effects are crucial to light-matter interaction in strong field and can be verified in experiments by 10PW laser facilities in the near future.
Frequency-tunable second-harmonic submillimeter-wave gyrotron oscillators
Sousa, Antonio C. Torrezan de (Antonio Carlos Torrezan de)
2010-01-01T23:59:59.000Z
This thesis reports the design and experimental demonstration of frequency-tunable submillimeter-wave gyrotrons operating in continuous wave (CW) at the second harmonic of the electron cyclotron frequency. An unprecedented ...
E. Paal; J. Virkepu
2010-02-14T23:59:59.000Z
Operadic Lax representations for the harmonic oscillator are used to construct the quantum counterparts of three-dimensional real Lie algebras. The Jacobi operators of these quantum algebras are explicitly calculated.
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.
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 ...
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.
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.
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 ...
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....
Time-frequency analysis and Harmonic Gaussian Functions
Tokiniaina Ranaivoson; Raoelina Andriambololona; Rakotoson Hanitriarivo
2013-08-08T23:59:59.000Z
A method for time-frequency analysis is given. The approach utilizes properties of Gaussian distribution, properties of Hermite polynomials and Fourier analysis. We begin by the definitions of a set of functions called harmonic Gaussian functions. Then these functions are used to define a set of transformations,noted T_n, which associate to a function {\\psi},of the time variable t, a set of functions {\\Psi}_n which depend on time, frequency and frequency (or time) standard deviation. Some properties of the transformations T_n and the functions {\\Psi}_n are given. It is proved in particular that the square of the modulus of each function {\\Psi}_n can be interpreted as a representation of the energy distribution of the signal, represented by the function {\\psi}, in the time-frequency plane for a given value of the frequency (or time) standard deviation. It is also shown that the function {\\psi}, can be recovered from the functions{\\Psi}_n.
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.
Energy transport by acoustic modes of harmonic lattices
Lisa Harris; Jani Lukkarinen; Stefan Teufel; Florian Theil
2006-11-21T23:59:59.000Z
We study the large scale evolution of a scalar lattice excitation which satisfies a discrete wave-equation in three dimensions. We assume that the dispersion relation associated to the elastic coupling constants of the wave-equation is acoustic, i.e., it has a singularity of the type |k| near the vanishing wave vector, k=0. To derive equations that describe the macroscopic energy transport we introduce the Wigner transform and change variables so that the spatial and temporal scales are of the order of epsilon. In the continuum limit, which is achieved by sending the parameter epsilon to 0, the Wigner transform disintegrates into three different limit objects: the transform of the weak limit, the H-measure and the Wigner-measure. We demonstrate that these three limit objects satisfy a set of decoupled transport equations: a wave-equation for the weak limit of the rescaled initial data, a dispersive transport equation for the regular limiting Wigner measure, and a geometric optics transport equation for the H-measure limit of the initial data concentrating to k=0. A simple consequence of our result is the complete characterization of energy transport in harmonic lattices with acoustic dispersion relations.
Tang, Xiaoli [Physics Department, Auburn University, Auburn, Alabama (United States); Dong, Jianjun [Physics Department, Auburn University, Auburn, Alabama (United States)
2009-05-01T23:59:59.000Z
We report a recent first-principles calculation of harmonic and anharmonic lattice dynamics of MgO. The 2nd order harmonic and 3rd order anharmonic interatomic interaction terms are computed explicitly, and their pressure dependences are discussed. The phonon mode Grueneisen parameters derived based on our calculated 3rd order lattice anharmonicity are in good agreement with those estimated using the finite difference method. The implications for lattice thermal conductivity at high pressure are discussed based on a simple kinetic transport theory.
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.
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...
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.
Fluid simulations of frequency effects on nonlinear harmonics in inductively coupled plasma
Si Xuejiao; Xu Xiang; Wang Younian [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Zhao Shuxia [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Department of Chemistry, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk-Antwerp (Belgium); Bogaerts, A. [Department of Chemistry, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, BE-2610 Wilrijk-Antwerp (Belgium)
2011-03-15T23:59:59.000Z
A fluid model is self-consistently established to investigate the harmonic effects in an inductively coupled plasma, where the electromagnetic field is solved by the finite difference time domain technique. The spatiotemporal distribution of harmonic current density, harmonic potential, and other plasma quantities, such as radio frequency power deposition, plasma density, and electron temperature, have been investigated. Distinct differences in current density have been observed when calculated with and without Lorentz force, which indicates that the nonlinear Lorentz force plays an important role in the harmonic effects, especially at low frequencies. Moreover, the even harmonics are larger than the odd harmonics both in the current density and the potential. Finally, the dependence of various plasma quantities with and without the Lorentz force on various driving frequencies is also examined. It is shown that the deposited power density decreases and the depth of penetration increases slightly because of the Lorentz force. The electron density increases distinctly while the electron temperature remains almost the same when the Lorentz force is taken into account.
Chan, Kwing Lam
. structure equations including rotational and tidal distortions and calculations for 1, 2, and 0.65 solar on the radiation energy spectrum of a radiative fluid, Phys. of Fluids, 18, 1814-1816. (6) Chan, K. L. 1977 the relationship between solar radius and luminosity variations, Solar Phys., 76, 145-153. 1 #12;(20) Henriksen, R
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
Utah, University of
Densification and Distortion in Selective Laser Sintering of Polycarbonate M. Berzins, T. H. C to vary with temperature. A study of polycarbonate part 'curl' distortion is also reported the sintering process and about warping. A previous study of the sintering of polycarbonate parts by a scanning
Boyd, Robert W.
Reducing pulse distortion in fast-light pulse propagation through an erbium-doped fiber amplifier.65.Àk Keywords: Fast-light propagation Pulse distortion reduction Erbium-doped fiber a b s t r a c t It was reported earlier that it is possible to obtain large pulse advancement with minimum pulse distor- tion
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.
Kung, Andy
Numerical Analysis of Fifth-Harmonic Conversion of Low-Power Pulsed Nd:YAG Laser with Resonance,2) In most of these reported work, high power UV generation requires either a very expensive high power laser, or focusing a low power laser tightly to reach sufficient intensity for efficient conversion. However, tight
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.
Power limitations and pulse distortions in an Yb : KGW chirped-pulse amplification laser system
Kim, G H; Yang, J; Kulik, A V; Sall, E G; Chizhov, S A; Kang, U [KERI, Russia Science Seuol, 612, DMC, Hi-Tech Industry Center, 1580 Sangam-dong, Mapo-gu, 121-835 Seoul (Korea, Republic of); Yashin, V E [Federal State Unitary Enterprise ' Scientific and Industrial Corporation 'Vavilov State Optical Institute', St. Petersburg (Russian Federation)
2013-08-31T23:59:59.000Z
We have studied self-action effects (self-focusing and self-phase modulation) and stimulated Raman scattering in an Yb : KGW chirped-pulse amplification laser system. The results demonstrate that self-focusing in combination with thermal lensing may significantly limit the chirped pulse energy in this system (down to 200 ?J) even at a relatively long pulse duration (50 ps). Nonlinear lenses in the laser crystals in combination with thermal lenses bring the regenerative amplifier cavity in the laser system to the instability zone and limit the average output power at pulse repetition rates under 50 kHz. Self-phase modulation, a manifestation of self-action, may significantly distort a recompressed femtosecond pulse at energies near the self-focusing threshold. Stimulated Raman scattering in such a laser has a weaker effect on output parameters than do self-focusing and thermal lensing, and Raman spectra are only observed in the case of pulse energy instability. (nonlinear optical phenomena)
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}.
Density- and wavefunction-normalized Cartesian spherical harmonics for l ? 20
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Michael, J. Robert; Volkov, Anatoliy
2015-03-01T23:59:59.000Z
The widely used pseudoatom formalism 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 density-normalized Cartesian spherical harmonic functions for up to l ? 7 and the corresponding normalization coefficients were reported previously by Paturle & Coppens. It was shown that the analytical form for normalization coefficients is available primarily forl ? 4. Only in very special cases it is possible to derive an analytical representation of the normalization coefficients for 4 l ? 7.more »In most cases for l > 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 method in the Wolfram Mathematicasoftware 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
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.
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.
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...
Regularity properties of stationary harmonic functions whose Laplacian is a Radon measure
Rémy Rodiac
2015-04-28T23:59:59.000Z
We study the regularity of Radon measures $\\mu$ which satisfy that there exists a function $h_\\mu$ in $H^1(\\Omega)$, stationary harmonic such that $\\Delta h_\\mu =\\mu$ in $\\Omega$ (here $\\Omega$ is an open set of $\\mathbb{R}^2$). Such conditions appear in physical contexts such as the study of a limiting vorticity measure associated to a family $(u_\\varepsilon)_\\varepsilon$ of solutions of the Ginzburg-Landau system without magnetic field. Under these conditions we prove that locally there exists a harmonic function $H$ such that the support of the measure is contained in the set of zeros of $H$. Using the local structure of the set of zeros of harmonic functions we can thus obtain that locally the support of $\\mu$ is a union of smooth simple
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.
D. Pagel; A. Alvermann; H. Fehske
2013-01-24T23:59:59.000Z
We study the dissipative quantum harmonic oscillator with general non-thermal preparations of the harmonic oscillator bath. The focus is on equilibration of the oscillator in the long-time limit and the additional requirements for thermalization. Our study is based on the exact solution of the microscopic model obtained by means of operator equations of motion, which provides us with the time evolution of the central oscillator density matrix in terms of the propagating function. We find a hierarchy of conditions for thermalization, together with the relation of the asymptotic temperature to the energy distribution in the initial bath state. We discuss the presence and absence of equilibration for the example of an inhomogeneous chain of harmonic oscillators, and illustrate the general findings about thermalization for the non-thermal environment that results from a quench.
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.
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.
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
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
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); published July 7, 2014 Gamma-ray photons with energy >9 MeV were produced when second-harmonic-generated to scatter. Since the two pulses play very different roles in the -ray generation process, and thus have
Chu, Shih-I
Generation of circularly polarized multiple high-order harmonic emission from two-color crossed for the production of circularly polarized multiple high-order harmonic generation HHG . The proposed experimental as the mechanism for the generation of continuous background radiation. S1050-2947 98 50410-6 PACS number s : 42
Tolbert, Leon M.
or in parallel an ac grid with distributed energy resources such as photovoltaics (solar cells), fuel cells to Solving the Harmonic Elimination Equations in Multilevel Converters John N. Chiasson, Senior Member, IEEE exist. A unified ap- proach is presented to solve the harmonic elimination equations for all
Chu, Shih-I
-dimensional quantum study of the coherent control of high-order harmonic generation HHG processes in intense pulsed.65.Ky, 32.80.Wr The study of coherent control of atomic and molecular processes is a subject of muchOptimization of high-order harmonic generation by genetic algorithm and wavelet time
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
So, Hing-Cheung
SPEECH ENHANCEMENT IN CAR NOISE ENVIRONMENT BASED ON AN ANALYSIS- SYNTHESIS APPROACH USING HARMONIC using harmonic noise model (HNM) in car noise environment. The major advantages of this method are effective suppression of car noise even in very low signal-to-noise ratio environments and mitigation
Saidi, E.H. (Laboratoire de Physique Theorique, Faculte de Sciences, Battouta, Rabat (MA))
1987-01-01T23:59:59.000Z
The N=2 harmonic superspace in the presence of central charges is developed. Renormalizable interactions unusual in N=2 supersymmetric theories are derived in a consistent way. Symmetries generated by the central charges are discussed. A certain equivalence between N=2 harmonic superspace with and without central charges is established. An Abelian generalization of the model is given.
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
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 ...
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.
Second-harmonic generation excited by a rotating Laguerre-Gaussian beam
Petrov, Dmitri [ICFO - Institut de Ciencies Fotoniques, Mediterranean Technology Park, ES-08860, Castelldefels (Barcelona), Spain and ICREA - Institucio Catalana de Recerca i Estudis Avancats, ES-08010, Barcelona (Spain)
2010-09-15T23:59:59.000Z
Experimental data demonstrate that unlike linear optical processes, an optical Laguerre-Gaussian beam of frequency {omega}, with topological charge m, rotating with angular frequency {Omega}<<{omega}, may not be considered as a monochromatic beam with the shifted frequency {omega}+m{Omega} (Doppler angular shift) for the second-harmonic generation nonlinear process.
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-electron laser (FEL) beamlines which use the har- monic cascade approach to produce coherent XUV & soft X, as well as those from analytical mod- els, to examine certain aspects of the predicted FEL per- formance
Simulation of a parametric quartz crystal oscillator by the symbolic harmonic method
Paris-Sud XI, Université de
method amounts to compute the behavior of the linear part of the circuit in the frequency domain differential equations describing the oscillator circuit is replaced by a system of non- linear equations de l'Observatoire, F-25044 Besan¸con, France The Symbolic Harmonic Analysis (SHA) method
High-harmonic generation in a dense medium V. V. Strelkov,1,2,
Becker, Andreas
2 General Physics Institute of Russian Academy of Sciences, Moscow, Russia 3 Physics Department, M. V. Lomonosov Moscow State University, Moscow, Russia Received 22 September 2004; published 16 May 2005 The high-harmonic generation in a plasma or gas under conditions when the single-atom response
High-resolution frequency-domain second-harmonic optical coherence tomography
Chen, Zhongping
capability for high-resolution optical 3D sec- tioning of samples because signals only arise from the focal structure of the specimen and its orientation relative to the laser beam. In biological materials, collagenHigh-resolution frequency-domain second-harmonic optical coherence tomography Jianping Su, Ivan V
Dramatic Enhancement of Third-Harmonic Generation in Three-Dimensional Photonic Crystals
Boyd, Robert W.
of optical elements on the chip [6]. In addition, complex defect waveguide structures can be achieved in 3D February 2004) We have observed a dramatic enhancement of third-harmonic generation in 3D polystyrene crystals possess optical properties not present in any naturally occurring material; these properties can
On time-reversal and space-time harmonic processes for Markovian quantum channels
Francesco Ticozzi; Michele Pavon
2009-04-29T23:59:59.000Z
The time reversal of a completely-positive, nonequilibrium discrete-time quantum Markov evolution is derived via a suitable adjointness relation. Space-time harmonic processes are introduced for the forward and reverse-time transition mechanisms, and their role for relative entropy dynamics is discussed.
Calibrating the sensing-coil radius by feed-down from a harmonic reference
Arpaia, Pasquale; Koster, Oliver; Russenschuck, Stephan; Severino, Giordana
2015-01-01T23:59:59.000Z
A method for calibrating the radius of rotating, harmonic sensing coils is proposed that allows relaxing constraints on alignment and field errors of the reference quadrupole magnet. Radius calibration considering roll angle misalignment between the measurement bench, the magnet, and the motor-drive unit is studied first. We then study the calibration error when
Popov, Alexander K
2015-01-01T23:59:59.000Z
Comparative analysis of second harmonic generation in ordinary and backward-wave settings is presented. Extraordinary properties of frequency doubling nonlinear optical reflectivity and pulse shaping through phase matching of ordinary and backward electromagnetic waves in the nanowaveguides with mixed negative/positive spatial dispersion is demonstrated with numerical simulations.
A New Approach to Solving the Harmonic Elimination Equations for a Multilevel Converter
Tolbert, Leon M.
is required. A multilevel inverter is ideal for connecting such distributed dc energy sources (solar cellsA New Approach to Solving the Harmonic Elimination Equations for a Multilevel Converter John N that the transcendental equations characterizing the har- monic content can be converted to polynomial equations which
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
Maas, Ruben; Parsons, James; Polman, Albert
2014-01-01T23:59:59.000Z
We study the propagation of light in a three-dimensional double-periodic Ag/TiO2 multilayer metamaterial composed of coupled plasmonic waveguides operating in the visible and UV spectral range. For these frequencies, light propagation in the plane of the waveguides is described by a negative phase velocity, while for the orthogonal direction light propagation is described by a Bloch wave composed of a large number of harmonics. As a result, the material cannot generally be described by a single phase index: decomposing the Bloch wave into different harmonics we show that for the wavelength range of interest the positive index m=1 harmonic dominates the propagation of light in the orthogonal direction. These results are corroborated by numerical simulations and optical refraction experiments on a double-periodic Ag/TiO2 multilayer metamaterial prism in the 380-600 nm spectral range, which show that positive refraction associated with right-handed harmonics dominates. Studying the isofrequency contours we find ...
Smerdon, Jason E.
Simulating heat transport of harmonic temperature signals in the Earth's shallow subsurface: Lower changes, freeze-thaw cycles, and hydrologic dynamics. It is uncertain, however, whether the reported atmospheric simulations. Citation: Smerdon, J. E., and M. Stieglitz (2006), Simulating heat transport
Continuous wave second-harmonic generation using domain-disordered quasi-phase matching waveguides
, 10 King's College Road, Ontario M5S 3G4, Canada 2 Department of Electronics and Electrical. Hutchings2 1 Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto fundamental source. Output second-harmonic powers of up to 1.6 W were measured when on a Fabry-Pérot resonance
Nonlinear harmonic modeling of phemt devices for increased power amplifier efficiencies
Strassner, Bernd Herbert
1997-01-01T23:59:59.000Z
This thesis is a comprehensive study of how harmonic terminations can greatly increase a power amplifier's efficiency (PAE). To show this improvement, the PHEMT amplifier is biased in the low noise region of operation (L, = 20 mA, Vd, = 3 V...
Numerical analysis of BoseEinstein condensation in a three-dimensional harmonic oscillator potential
Ligare, Martin
Numerical analysis of BoseEinstein condensation in a three-dimensional harmonic oscillator 24 March 1997; accepted 12 May 1997 BoseEinstein condensation is the anomalous accumulation the conditions of the recent experiments achieving BoseEinstein condensation in laser-cooled alkali vapors
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
Nonergodic behavior of interacting bosons in harmonic traps Thomas Papenbrock and George F. Bertsch
Bertsch George F.
Nonergodic behavior of interacting bosons in harmonic traps Thomas Papenbrock and George F. Bertsch of the ground-state occupation number. In the high-energy regime of classical physics we find nonergodic behavior for modest numbers of trapped particles. We give two conditions that assure the ergodic behavior
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
Ground vibration due to a high-speed moving harmonic rectangular load on a
Avignon et des Pays de Vaucluse, Université de
Ground vibration due to a high-speed moving harmonic rectangular load on a poroviscoelastic half'Avignon, Facult´e des Sciences, 33 rue Louis Pasteur, F-84000 Avignon, France RUNNING TITLE: Vibrations induced) #12;Abstract The transmission of vibrations in the ground, due to a high-speed moving vertical har
Enhancement of high-harmonic generation by laser-induced cluster vibration
Enhancement of high-harmonic generation by laser-induced cluster vibration Yen-Mu Chen,1,2 Ming a new tool for studying the vibrational dynamics of nanometer atomic clusters. Â© 2007 Optical Society vibration was reported [8], and the results indicate that HHG is a very sensitive probe for vibrational
Extended BRS and anti-BRS symmetries in N=2 harmonic superspace
Lhallabi, T.; Saidi, E.H. (L.P.T., av. Ibn Battouta, Rabat (MA))
1988-01-01T23:59:59.000Z
The full set of extended BRS and anti-BRS symmetries are derived for components of superconnection and gauge superfield using the N = 2 harmonic superspace. The quantization of N = 2 supersymmetric theory is developed and the proof of its gauge invariance is presented.
Nonlinear harmonic modeling of phemt devices for increased power amplifier efficiencies
Strassner, Bernd Herbert
1997-01-01T23:59:59.000Z
This thesis is a comprehensive study of how harmonic terminations can greatly increase a power amplifier's efficiency (PAE). To show this improvement, the PHEMT amplifier is biased in the low noise region of operation (L, = 20 mA, Vd, = 3 V...
DAVID BEN-ZVI Goal: develop basic tools of representation theory. and harmonic
Proudfoot, Nicholas
OVERVIEW DAVID BEN-ZVI Goal: develop basic tools of representation theory. and harmonic analysis analysis for categories. Need basic alge- bra for categories. These will be given by the theory A, there is a G-action on A -mod. Â· Physics. G-gauge theories, QFTs with G
Tolbert, Leon M.
Converters, Harmonic Elimination, Resultants, Symmetric Polynomials I. Introduction Electric power production and information infrastructure. A shift will take place from a relatively few large, concentrated generation be obtained from solar cells, fuel cells, or ul- tracapacitors. Figure 1 shows a single-phase structure
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
Masoud, Ahmad A.
in a Cluttered Environment Ahmad A. Masoud Electrical engineering, King Fahd University of Petroleum & Minerals to govern their motion (also known as the control protocol) is extracted from a harmonic potential field operators in order to manage the complexity of the process or in a fully autonomous mode as regulators
Chu, Shih-I
2015-01-01T23:59:59.000Z
PHYSICAL REVIEW A 91, 063408 (2015) Optimal control of high-order harmonics for the generation an efficient high-order-harmonic optimal control scheme for the generation of the ultrabroad supercontinuum NEWUOA (NEW Unconstrained Optimization Algorithm). For illustration, the high-order-harmonic generation
Capineri, Lorenzo, E-mail: lorenzo.capineri@unifi.it [Dipartimento Ingegneria dell’Informazione, Università degli Studi di Firenze, Via S. Marta 3, 50139 Firenze (Italy)
2014-10-01T23:59:59.000Z
This paper presents the design and the realization of a linear power amplifier with large bandwidth (15 MHz) capable of driving low impedance ultrasonic transducers. The output current driving capability (up to 5 A) and low distortion makes it suitable for new research applications using high power ultrasound in the medical and industrial fields. The electronic design approach is modular so that the characteristics can be scaled according to specific applications and implementation details for the circuit layout are reported. Finally the characterization of the power amplifier module is presented.
Psikal, J., E-mail: jan.psikal@fjfi.cvut.cz [FNSPE, Czech Technical University in Prague, 11519 Prague (Czech Republic); Klimo, O. [FNSPE, Czech Technical University in Prague, 11519 Prague (Czech Republic); ELI-Beamlines Project, Institute of Physics of the ASCR, 18221 Prague (Czech Republic); Weber, S.; Margarone, D. [ELI-Beamlines Project, Institute of Physics of the ASCR, 18221 Prague (Czech Republic)
2014-07-15T23:59:59.000Z
The influence of laser frequency on laser-driven ion acceleration is investigated by means of two-dimensional particle-in-cell simulations. When ultrashort intense laser pulse at higher harmonic frequency irradiates a thin solid foil, the target may become re lativistically transparent for significantly lower laser pulse intensity compared with irradiation at fundamental laser frequency. The relativistically induced transparency results in an enhanced heating of hot electrons as well as increased maximum energies of accelerated ions and their numbers. Our simulation results have shown the increase in maximum proton energy and increase in the number of high-energy protons by a factor of 2 after the interaction of an ultrashort laser pulse of maximum intensity 7?×?10{sup 21?}W/cm{sup 2} with a fully ionized plastic foil of realistic density and of optimal thickness between 100?nm and 200?nm when switching from the fundamental frequency to the third harmonics.
Saha, Anirban
2015-01-01T23:59:59.000Z
We investigate the quantum mechanical transitions, induced by the combined effect of Gravitational wave (GW) and noncommutative (NC) structure of space, among the states of a 2-dimensional harmonic oscillator. The phonon modes excited by the passing GW within the resonant bar-detector are formally identical to forced harmonic oscillator and they represent a length variation of roughly the same order of magnitude as the characteristic length-scale of spatial noncommutativity estimated from the phenomenological upper bound of the NC parameter. This motivates our present work. We employ a number of different GW wave-forms that are typically expected from possible astronomical sources. We find that the transition probablities are quite sensitive to the nature of polarization of the GW. We further elaborate on the particular type of sources of GW radiation which can induce transitions that can be used as effective probe of the spatial noncommutative structure.
Analysis and Control of Period-Doubling Bifurcation in Buck Converters Using Harmonic Balance
Chung-Chieh Fang; Eyad H. Abed
2012-10-27T23:59:59.000Z
Period doubling bifurcation in buck converters is studied by using the harmonic balance method. A simple dynamic model of a buck converter in continuous conduction mode under voltage mode or current mode control is derived. This model consists of the feedback connection of a linear system and a nonlinear one. An exact harmonic balance analysis is used to obtain a necessary and sufficient condition for a period doubling bifurcation to occur. If such a bifurcation occurs, the analysis also provides information on its exact location. Using the condition for bifurcation, a feedforward control is designed to eliminate the period doubling bifurcation. This results in a wider range of allowed source voltage, and also in improved line regulation.
Filho, Faete [ORNL; Maia, Helder Z [UFMS, Department of Electrical Engineering; Mateus, Tiago Henrique D [ORNL; Ozpineci, Burak [ORNL; Tolbert, Leon M [ORNL; Pinto, Joao Onofre P [ORNL
2013-01-01T23:59:59.000Z
A new approach for modulation of an 11-level cascade multilevel inverter using selective harmonic elimination is presented in this paper. The dc sources feeding the multilevel inverter are considered to be varying in time, and the switching angles are adapted to the dc source variation. This method uses genetic algorithms to obtain switching angles offline for different dc source values. Then, artificial neural networks are used to determine the switching angles that correspond to the real-time values of the dc sources for each phase. This implies that each one of the dc sources of this topology can have different values at any time, but the output fundamental voltage will stay constant and the harmonic content will still meet the specifications. The modulating switching angles are updated at each cycle of the output fundamental voltage. This paper gives details on the method in addition to simulation and experimental results.
Tilli, Andrea; Conficoni, Christian
2011-01-01T23:59:59.000Z
In this chapter some results related to Shunt Active Filters (SAFs) and obtained by the authors and some coauthors are reported. SAFs are complex power electronics equipments adopted to compensate for cur-rent harmonic pollution in electric mains, due to nonlinear loads. By using a proper "floating" capacitor as energy reservoir, the SAF purpose is to inject in the line grid currents canceling the polluting har-monics. Control algorithms play a key role for such devices and, in general, in many power electronics applications. Moreover, systems theory is crucial, since it is the mathematical tool that enables a deep understanding of the involved dynamics of such systems, allowing a correct dimensioning, beside an effective control. As a matter of facts, current injection objective can be straightforwardly formulated as an output tracking control problem. In this fashion, the structural and insidious marginally-stable internal/zero dynamics of SAFs can be immediately highlighted and characterized in terms of si...
Raja, Anju M.
Pulse-modulated second harmonic imaging microscopes (PM-SHIMs) exhibit improved signal-to-noise ratio (SNR) over conventional SHIMs on sensitive imaging and quantification of weak collagen signals inside tissues. We quantify ...
Fourth-order harmonic generation during parametric four-wave mixing in the filaments in ambient air
Ganeev, R. A. [Raja Ramanna Centre for Advanced Technology, Indore 425 013 (India); Institute of Electronics, 33 Dormon Yoli Street, Tashkent 100 125 (Uzbekistan); Singhal, H.; Naik, P. A.; Chakera, J. A.; Kumar, M.; Gupta, P. D. [Raja Ramanna Centre for Advanced Technology, Indore 425 013 (India)
2010-10-15T23:59:59.000Z
We propose a simplified scheme for efficient 200-nm pulse generation in isotropic medium using 800-nm radiation. The observation and optimization of the fourth-order harmonic generation during two-color filamentation in air are reported. This parametric process is based on four-wave mixing of the fundamental and the second-order harmonic radiation of the Ti:sapphire laser. A systematic study of the influence of the laser intensity, the polarization, the chirp, and the pulse duration on the fourth-order harmonic output from the filaments has been carried out. The fourth-order harmonic conversion efficiency was estimated to be of the order of 10{sup -4}.
Design of a Low Power 70MHz-110MHz Harmonic Rejection Filter with Class-AB Output Stage
Huang, Shan
2011-08-08T23:59:59.000Z
An FM transmitter becomes the new feature in recent portable electronic development. A low power, integrable FM transmitter filter IC is required to meet the demand of FM transmitting feature. A low pass filter using harmonic rejection technique...
Carrera, Juan J.; Chu, Shih-I
2007-03-16T23:59:59.000Z
We present an ab initio quantum investigation of the high-order harmonic generation (HHG) cutoff extension using intense few-cycle chirped laser pulses. For a few-cycle chirped driving laser pulse, it is shown that significant ...
Ransom, Ray M. (Big Bear City, CA); Gallegos-Lopez, Gabriel (Torrance, CA); Kinoshita, Michael H. (Redondo Beach, CA)
2012-07-31T23:59:59.000Z
Methods, system and apparatus are provided for quickly approximating a peak summed magnitude (A) of a phase voltage (Vph) waveform in a multi-phase system that implements third harmonic injection.
Price, Rachel Elizabeth
2011-01-01T23:59:59.000Z
Recent works have discussed "chaotic" or "Type-II" riser motion and suggested that it is a general feature of VIV riser response. Chaotic riser response contains broad-banded harmonics and a combination of standing and ...
Jiang, Tsin-Fu; Chu, Shih-I
1992-12-01T23:59:59.000Z
We present a study of the high-order harmonic-generation (HG) spectra of atomic hydrogen at 248 nm based on the Fourier transform of the expectation values of the induced dipole moment and acceleration. The calculations ...
The (4,0) and (4,4) supersymmetric nonlinear. sigma. -models in the D = 2 harmonic superspace
Lhallabi, T.; Saidi, E.H. (L.P.T. Faculte des Sciences, Av. Ibn Battouta, P.O. Box 1014, Rabat (MA))
1988-01-01T23:59:59.000Z
The D = 2(4,0) and (4,4) harmonic superspace are constructed. Nonlinear supersymmetric {sigma}-models for both real and complex (4,0) matter multiplets are obtained. Other features are also discussed.
Biswanath Rath; P. Mallick
2015-01-25T23:59:59.000Z
We propose zero energy correction method for non-Hermiition Harmonic oscillator under simultaneous transformation of co-ordinate $(x \\rightarrow \\frac{(x+ i\\lambda p)}{\\sqrt{(1+\\beta \\lambda)}}$ and momentum $(p \\rightarrow \\frac{(p+ i\\beta x)}{\\sqrt{(1+\\beta \\lambda)}}$ for getting energy eigenvalue in place of extending the idea of gaugelike transformation proposed earlier in momentum transformation $(p \\rightarrow p+i\\beta x)$ by Z.Ahmed [Phys.Lett A 294,287 (2002)]. Further energy of non-Hermitian Harmonic oscillator remains the same as that of Harmonic oscillator. PACS: 03. 65 Db Key words.Non-Hermitian Harmonic oscillator, Perturbation theory,Energy level.
Design of a Low Power 70MHz-110MHz Harmonic Rejection Filter with Class-AB Output Stage
Huang, Shan
2011-08-08T23:59:59.000Z
An FM transmitter becomes the new feature in recent portable electronic development. A low power, integrable FM transmitter filter IC is required to meet the demand of FM transmitting feature. A low pass filter using harmonic rejection technique...
High harmonic attosecond pulse train amplification in a free electron laser
McNeil, B.W.; Sheehy, B.; Thompson, N.R.; Dunning, D.J.
2011-03-04T23:59:59.000Z
It is shown using three-dimensional simulations that the temporal structure of an attosecond pulse train, such as that generated via high harmonic generation in noble gases, may be retained in a free electron laser amplifier through to saturation using a mode-locked optical klystron configuration. At wavelengths of {approx}12 nm, a train of attosecond pulses of widths {approx}300 as with peak powers in excess of 1 GW are predicted.
Klystron-like cavity with mode transformation for high-harmonic terahertz gyrotrons
Bandurkin, I. V.; Kalynov, Yu. K. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Savilov, A. V. [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod (Russian Federation)
2013-01-15T23:59:59.000Z
A novel cavity scheme of a gyrotron is proposed and investigated. As it provides low Ohmic losses and high mode selectivity, it can be especially prospective for realization in gyrotrons operating in the THz frequency range. Numerical simulations show that it allows three-fold increase in the efficiency of the low-relativistic 500 GHz fourth-harmonic gyrotron as compared to conventional two-section scheme with modes transformation.
Gibbs attractor: a chaotic nearly Hamiltonian system, driven by external harmonic force
P. V. Elyutin
2003-09-08T23:59:59.000Z
A chaotic autonomous Hamiltonian systems, perturbed by small damping and small external force, harmonically dependent on time, can acquire a strange attractor with properties similar to that of the canonical distribution - the Gibbs attractor. The evolution of the energy in such systems can be described as the energy diffusion. For the nonlinear Pullen - Edmonds oscillator with two degrees of freedom the properties of the Gibbs attractor and their dependence on parameters of the perturbation are studied both analytically and numerically.
Whitaker, M.; Heath, G. A.; O'Donoughue, P.; Vorum, M.
2012-04-01T23:59:59.000Z
This systematic review and harmonization of life cycle assessments (LCAs) of utility-scale coal-fired electricity generation systems focuses on reducing variability and clarifying central tendencies in estimates of life cycle greenhouse gas (GHG) emissions. Screening 270 references for quality LCA methods, transparency, and completeness yielded 53 that reported 164 estimates of life cycle GHG emissions. These estimates for subcritical pulverized, integrated gasification combined cycle, fluidized bed, and supercritical pulverized coal combustion technologies vary from 675 to 1,689 grams CO{sub 2}-equivalent per kilowatt-hour (g CO{sub 2}-eq/kWh) (interquartile range [IQR]= 890-1,130 g CO{sub 2}-eq/kWh; median = 1,001) leading to confusion over reasonable estimates of life cycle GHG emissions from coal-fired electricity generation. By adjusting published estimates to common gross system boundaries and consistent values for key operational input parameters (most importantly, combustion carbon dioxide emission factor [CEF]), the meta-analytical process called harmonization clarifies the existing literature in ways useful for decision makers and analysts by significantly reducing the variability of estimates ({approx}53% in IQR magnitude) while maintaining a nearly constant central tendency ({approx}2.2% in median). Life cycle GHG emissions of a specific power plant depend on many factors and can differ from the generic estimates generated by the harmonization approach, but the tightness of distribution of harmonized estimates across several key coal combustion technologies implies, for some purposes, first-order estimates of life cycle GHG emissions could be based on knowledge of the technology type, coal mine emissions, thermal efficiency, and CEF alone without requiring full LCAs. Areas where new research is necessary to ensure accuracy are also discussed.
Zhang, Xiaoshi (Superior, CO); Lytle, Amy L. (Boulder, CO); Cohen, Oren (Boulder, CO); Kapteyn, Henry C. (Boulder, CO); Murnane, Margaret M. (Boulder, CO)
2010-11-09T23:59:59.000Z
All-optical quasi-phase matching (QPM) uses a train of counterpropagating pulses to enhance high-order harmonic generation (HHG) in a hollow waveguide. A pump pulse enters one end of the waveguide, and causes HHG in the waveguide. The counterpropagation pulses enter the other end of the waveguide and interact with the pump pulses to cause QPM within the waveguide, enhancing the HHG.
Laser-induced bound-state phases in high-order harmonic generation
Etches, Adam; Madsen, Lars Bojer
2015-01-01T23:59:59.000Z
We present single-molecule and macroscopic calculations showing that laser-induced Stark shifts contribute significantly to the phase of high-order harmonics from polar molecules. This is important for orbital tomography, where phases of field-free dipole matrix elements are needed in order to reconstruct molecular orbitals. We derive an analytical expression that allows the first-order Stark phase to be subtracted from experimental measurements.
M. Daoud; A. Jellal; E. B. Choubabi; E. H. El Kinani
2012-10-29T23:59:59.000Z
We introduce a special class of truncated Weyl-Heisenberg algebra and discuss the corresponding Hilbertian and analytical representations. Subsequently, we study the effect of a quantum network of beam splitting on coherent states of this nonlinear class of harmonic oscillators. We particularly focus on quantum networks involving one and two beam splitters and examine the degree of bipartite as well as tripartite entanglement using the linear entropy.
Calculation of the convex roof for an open entangled harmonic oscillator system
Landau, Mayer A.; Stroud, C. R. Jr. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)
2010-05-15T23:59:59.000Z
We explicitly calculate the time dependence of entanglement via the convex roof extension for a system of noninteracting harmonic oscillators. These oscillators interact only indirectly with each other by way of a zero-temperature bath. The initial state of the oscillators is taken to be that of an entangled Schroedinger-cat state. This type of initial condition leads to superexponential decay of the entanglement when the initial state has the same symmetry as the interaction Hamiltonian.
Efficiency enhancement of nonlinear odd harmonics in thermal free electron laser
Bazouband, F.; Maraghechi, B. [Department of Physics, Amirkabir University of Technology, 15875-4413 Tehran (Iran, Islamic Republic of)
2013-05-07T23:59:59.000Z
The effect of axial energy spread on the radiation of third harmonic is studied in the free electron laser with planar wiggler and ion-channel guiding. Spread in the longitudinal momentum and so in the initial energy of electron beam, without any spread in the transverse velocity, is assumed in the form of Gaussian distribution function. The technique that is employed is a one-dimensional and steady-state simulation. A set of self consistent nonlinear differential equations that describes the system is solved numerically by Runge-Kutta method. Due to the sensitivity of harmonics to thermal effects, gain improvement of third harmonic radiation is achieved by using ion-channel guiding technique and efficiency enhancement is applied by tapering the magnetic field of wiggler to optimize radiation. The bunching parameter of the electron beam is also studied. It is found that the growth of the magnitude of the bunching parameter that is caused by the ponderomotive wave stops before the saturation point of the radiation. This means that ponderomotive wave saturates at a shorter distance compared to the radiation.
Vuckovic, Jelena
Quasiresonant excitation of InP/InGaP quantum dots using second harmonic generated in a photonic://apl.aip.org/about/rights_and_permissions #12;Quasiresonant excitation of InP/InGaP quantum dots using second harmonic generated in a photonic signal to noise quasiresonant excitation of InP/InGaP quantum dots. The excitation is provided via second
Y. A. Owusu
1999-03-31T23:59:59.000Z
This report presents a statistical method of evaluating geometric tolerances of casting products using point cloud data generated by coordinate measuring machine (CMM) process. The focus of this report is to present a statistical-based approach to evaluate the differences in dimensional and form variations or tolerances of casting products as affected by casting gating system, molding material, casting thickness, and casting orientation at the mold-metal interface. Form parameters such as flatness, parallelism, and other geometric profiles such as angularity, casting length, and height of casting products were obtained and analyzed from CMM point cloud data. In order to relate the dimensional and form errors to the factors under consideration such as flatness and parallelism, a factorial analysis of variance and statistical test means methods were performed to identify the factors that contributed to the casting distortion at the mold-metal interface.
Opportunities for regional harmonization of appliance standards and l abeling program
McNeil, Michael A.
2003-09-01T23:59:59.000Z
The South Asian Regional Initiative for Energy (SARI/Energy) calls for a series of activities to promote Energy Efficiency Standards and Labeling (EES&L) of end use appliances in the region. In pursuit of this goal, the project supports several seminars and meetings that bring together policymakers and stakeholders from throughout the region. The purpose of these gatherings is to encourage a dialogue among participants as to the benefits and barriers associated with EES&L programs. In addition, it is the role of the program organizers to provide participants with the technical details necessary to make progress towards effective efficiency programs. One component of the initiative is to encourage the harmonization (alignment) of existing program components, and the pursuit of new programs coordinated at the regional level. In support of this goal, the report provides information aimed at motivating and enabling cooperative activities which will provide concrete benefits to programs in each country, whether well developed, or still in the initial planning stage. It should be emphasized that the underlying objective of the harmonization component of the SARI/Energy project is to increase the potential for success of EES&L programs of all countries involved, and to reduce burdens on manufacturers, exporters and importers in each country. Harmonization ''for it's own sake'' is not desirable, nor is it suggested that policymakers should bring their programs in line with international norms if doing so would present a disadvantage to their own efficiency programs, or to commercial interests within their country. If there is no such disadvantage, however, the program encourages alignment of policies and provides a forum at which this alignment can be pursued. The report covers several main topics, with varying emphasis. First, a general discussion of the motivation for an explicit policy of regional harmonization is given. Next, the current status of existing programs in the region are discussed in some detail. The section that follows covers the harmonization of efficiency test procedures. Special attention is given to this component of an EES&L program because it is the most critical element in terms of harmonization--having incompatible test procedures between trade partners can greatly impact the effectiveness of a program, and it can also unduly impact trade. Currently, policymakers in India and Sri Lanka are collaborating with the goal of aligning refrigerator test procedures used in their respective programs. For this reason, the section on test procedures of refrigerators goes into a significant amount of technical detail, in order to provide the clearest possible articulation of issues to be resolved in bringing the procedures into alignment. Following the discussion of test procedures, the report contains a section each on harmonization of efficiency rating levels, development of label designs, and enforcement issues. The report is organized such that the sections covering current programs and test procedures are subdivided by target appliance. These sections are further divided by country, where applicable. Each section is concluded with recommendations.
frequency scattered energy or the pulse distortion of short-period body waves, preferably in situations where the scattered energy precedes, rather than follows, the main seismic arrival, so, the imperfect account of mantle and core structure, the simpli- fied theoretical modelling of wave propagation
Kunze, Kerstin E. [Departamento de Física Fundamental and IUFFyM, Universidad de Salamanca, Plaza de la Merced s/n, 37008 Salamanca (Spain); Komatsu, Eiichiro, E-mail: kkunze@usal.es, E-mail: komatsu@mpa-garching.mpg.de [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild Str. 1, 85741 Garching (Germany)
2014-01-01T23:59:59.000Z
Primordial magnetic fields that exist before the photon-baryon decoupling epoch are damped on length scales below the photon diffusion and free-streaming scales. The energy injected into the plasma by dissipation of magnetosonic and Alfv and apos;en waves heats photons, creating a y-type distortion of the black-body spectrum of the cosmic microwave background. This y-type distortion is converted into a ?-type distortion when elastic Compton scattering is efficient. Therefore, we can use observational limits on y- and ?-type distortions to constrain properties of magnetic fields in the early universe. Assuming a Gaussian, random, and non-helical field, we calculate ? and y as a function of the present-day strength of the field, B{sub 0}, smoothed over a certain Gaussian width, k{sub c}{sup ?1}, as well as of the spectral index of the power spectrum of fields, n{sub B}, defined by P{sub B}(k)?k{sup n{sub B}}. For a nearly scale-invariant spectrum with n{sub B} = ?2.9 and a Gaussian smoothing width of k{sub c}{sup ?1} = 1Mpc, the existing COBE/FIRAS limit on ? yields B{sub 0} < 40 nG, whereas the projected PIXIE limit on ? would yield B{sub 0} < 0.8 nG. For non-scale-invariant spectra, constraints can be stronger. For example, for B{sub 0} = 1 nG with k{sub c}{sup ?1} = 1Mpc, the COBE/FIRAS limit on ? excludes a wide range of spectral indices given by n{sub B} > ?2.6. After decoupling, energy dissipation is due to ambipolar diffusion and decaying MHD turbulence, creating a y-type distortion. The distortion is completely dominated by decaying MHD turbulence, and is of order y ? 10{sup ?7} for a few nG field smoothed over the damping scale at the decoupling epoch, k{sub d,} {sub dec} ? 290(B{sub 0}/1nG){sup ?1}Mpc{sup ?1}. The projected PIXIE limit on y would exclude B{sub 0} > 1.0 and 0.6 nG for n{sub B} = ?2.9 and -2.3, respectively, and B{sub 0} > 0.6 nG for n{sub B} ? 2. Finally, we find that the current limits on the optical depth to Thomson scattering restrict the predicted y-type distortion to be y?<10{sup ?8}.
Use of Harmonic Inversion Techniques in Semiclassical Quantization and Analysis of Quantum Spectra
J. Main
1999-02-11T23:59:59.000Z
Harmonic inversion is introduced as a powerful tool for both the analysis of quantum spectra and semiclassical periodic orbit quantization. The method allows to circumvent the uncertainty principle of the conventional Fourier transform and to extract dynamical information from quantum spectra which has been unattainable before, such as bifurcations of orbits, the uncovering of hidden ghost orbits in complex phase space, and the direct observation of symmetry breaking effects. The method also solves the fundamental convergence problems in semiclassical periodic orbit theories - for both the Berry-Tabor formula and Gutzwiller's trace formula - and can therefore be applied as a novel technique for periodic orbit quantization, i.e., to calculate semiclassical eigenenergies from a finite set of classical periodic orbits. The advantage of periodic orbit quantization by harmonic inversion is the universality and wide applicability of the method, which will be demonstrated in this work for various open and bound systems with underlying regular, chaotic, and even mixed classical dynamics. The efficiency of the method is increased, i.e., the number of orbits required for periodic orbit quantization is reduced, when the harmonic inversion technique is generalized to the analysis of cross-correlated periodic orbit sums. The method provides not only the eigenenergies and resonances of systems but also allows the semiclassical calculation of diagonal matrix elements and, e.g., for atoms in external fields, individual non-diagonal transition strengths. Furthermore, it is possible to include higher order terms of the hbar expanded periodic orbit sum to obtain semiclassical spectra beyond the Gutzwiller and Berry-Tabor approximation.
Finite Larmor Radii Effects in Fast Ion Measurements as Demonstrated Using Neutron Emission Spectrometry of JET Plasmas Heated with 3rd Harmonic ICRF
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 SCIENCE May 1982 Ma jor Sub ject: Electrical Engineering A 80LID-STAT:, ;iidl 0RIC R'DTRAI&'!T, RRHTIAL RELAY FOR TR" K~'. :ORYiM PROT':CTIOI&' A Thesis GARY HOG". . R LOATH-'R Approved as to stv1e ann content b r: (Chairman of Committee ) (Head...
Method and apparatus for reducing the harmonic currents in alternating-current distribution networks
Beverly, L.H.; Hance, R.D.; Kristalinski, A.L.; Visser, A.T.
1996-11-19T23:59:59.000Z
An improved apparatus and method reduce the harmonic content of AC line and neutral line currents in polyphase AC source distribution networks. The apparatus and method employ a polyphase Zig-Zag transformer connected between the AC source distribution network and a load. The apparatus and method also employs a mechanism for increasing the source neutral impedance of the AC source distribution network. This mechanism can consist of a choke installed in the neutral line between the AC source and the Zig-Zag transformer. 23 figs.
Restricted thermalization for two interacting atoms in a multimode harmonic waveguide
Yurovsky, V. A.; Olshanii, M. [School of Chemistry, Tel Aviv University, IL-69978 Tel Aviv (Israel); Department of Physics, University of Massachusetts Boston, Boston, Massachusetts 02125 (United States)
2010-04-15T23:59:59.000Z
In this article, we study the thermalizability of a system consisting of two atoms in a circular, transversely harmonic waveguide in the multimode regime. While showing some signatures of quantum-chaotic behavior, the system fails to reach a thermal equilibrium in a relaxation from an initial state, even when the interaction between the atoms is infinitely strong. We relate this phenomenon to the previously addressed unattainability of a complete quantum chaos in the Seba billiard [P. Seba, Phys. Rev. Lett. 64, 1855 (1990)], and we conjecture the absence of a complete thermalization to be a generic property of integrable quantum systems perturbed by a nonintegrable but well-localized perturbation.
Transient particle energies in shortcuts to adiabatic expansions of harmonic traps
Yang-Yang Cui; Xi Chen; J. G. Muga
2015-05-12T23:59:59.000Z
The expansion of a harmonic potential that holds a quantum particle may be realized without any final particle excitation but much faster than adiabatically via "shortcuts to adiabaticity" (STA). While ideally the process time can be reduced to zero, practical limitations and constraints impose minimal finite times for the externally controlled time-dependent frequency protocols. We examine the role of different time-averaged energies (total, kinetic, potential, non-adiabatic) and of the instantaneous power in characterizing or selecting different protocols.Specifically, we prove a virial theorem for STA processes, set minimal energies for specific times or viceversa, and discuss their realizability by means of Dirac impulses or otherwise.
Broader source: Energy.gov [DOE]
As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.
Broader source: Energy.gov [DOE]
As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.
Broader source: Energy.gov [DOE]
As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.
Broader source: Energy.gov [DOE]
As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.
Spectral resolution of the Liouvillian of the Lindblad master equation for a harmonic oscillator
Honda, Daigo [Institute of Physics, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Nakazato, Hiromichi; Yoshida, Motoyuki [Department of Physics, Waseda University, Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)
2010-07-15T23:59:59.000Z
A Lindblad master equation for a harmonic oscillator, which describes the dynamics of an open system, is formally solved. The solution yields the spectral resolution of the Liouvillian, that is, all eigenvalues and eigenprojections are obtained. This spectral resolution is discussed in depth in the context of the biorthogonal system and the rigged Hilbert space, and the contribution of each eigenprojection to expectation values of physical quantities is revealed. We also construct the ladder operators of the Liouvillian, which clarify the structure of the spectral resolution.
Solomon, L.; Ingold, G.; Ben-Zvi, I.; Krinsky, S.; Yu, L.H.; Sampson, W.; Robins, K.
1993-07-01T23:59:59.000Z
An 18mm period, 0.54 Tesla, 8mm gap superconducting undulator with both horizontal and vertical focusing has been built and tested. This magnet, which is fabricated in 25 cm length sections, is being tested for use in the radiator section (total magnet length of 1.5 m) of the Harmonic Generation Free Electron Laser experiment at the National Synchrotron Light Source - Accelerator Test Facility at Brookhaven National Lab., in collaboration with Grumman Corp. The measurement system is outlined, sources and estimates of errors are described, and some magnetic field data are presented and discussed.
Harmonicity of unit vector fields with respect to a class of Riemannian metrics
A. Baghban; E. Abedi
2014-12-07T23:59:59.000Z
The isotropic almost complex structures induce a Riemannian metric $g_{\\delta,\\sigma}$ on TM, which are the generalized type of Sasakian metric. In this paper, the Levi-Civita connection of $g_{\\delta,\\sigma}$ is calculated and the harmonicity of unit vector fields from $(M, g)$ to $(S(M), i*g_{\\delta,0})$ is investigated, where $i*g_{\\delta,0}$ is a particular type of induced metric $i*g_{\\delta,\\sigma}$. Finally, an important example is presented which satisfies in main theorem of the paper.
Johan S. Høye; Iver Brevik
2011-06-04T23:59:59.000Z
The Casimir friction problem can be dealt with in a simplified way by considering two harmonic oscillators moving with constant relative velocity. Recently we calculated the energy dissipation for such a case, [EPL {\\bf 91}, 60003 (2010); Europ. Phys. J. D {\\bf 61}, 335 (2011)]. A recent study of Barton [New J. Phys. {\\bf 12}, 113044 (2010)] seemingly leads to a different result for the dissipation. If such a discrepancy really were true, it would imply a delicate difficulty for the basic theory of Casimir friction. In the present note we show that the expressions for the dissipation are in fact physically equivalent, at T=0.
Optical Third-Harmonic Generation in Graphene Hong, Sung-Young; Dadap,
Office of Scientific and Technical Information (OSTI)
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalyticPreparation andEnablingFiftyThird-Harmonic Generation in Graphene Hong,
Free Electron Lasers Seeded by ir Laser Driven High-order Harmonic Generation
Wu, Juhao; Bolton, Paul R.; /SLAC; Murphy, James B.; /BNL, NSLS; Zhong, Xinming; /Beijing Normal U.
2007-03-12T23:59:59.000Z
Coherent x-ray production by a seeded free electron laser (FEL) is important for next generation synchrotron light sources. We examine the feasibility and features of FEL emission seeded by a high-order harmonic of an infrared laser (HHG). In addition to the intrinsic FEL chirp, the longitudinal profile and spectral bandwidth of the HHG seed are modified significantly by the FEL interaction well before saturation. This smears out the original attosecond pulselet structure. We introduce criteria for this smearing effect on the pulselet and the stretching effect on the entire pulse. We discuss the noise issue in such a seeded FEL.
Self-Induced Harmonic Generation in a Storage-Ring Free-Electron Laser
De Ninno, G. [University of Nova Gorica (Slovenia); Sincrotrone Trieste, Basovizza (Trieste) (Italy); Allaria, E.; Danailov, M. B.; Diviacco, B.; Ferianis, M.; Karantzoulis, E.; Spezzani, C.; Trovo, M. [Sincrotrone Trieste, Basovizza (Trieste) (Italy); Coreno, M. [TASC-INFM National Laboratory, Basovizza (Trieste) (Italy); Chowdhury, S. [Xerox Research Center, Webster, New York (United States); Curbis, F. [Sincrotrone Trieste, Basovizza (Trieste) (Italy); University of Trieste (Italy); Longhi, E. C. [Diamond Light Source, Oxfordshire (United Kingdom); Pinayev, I. V.; Litvinenko, V. N. [Brookhaven National Laboratory, Upton, New York (United States)
2008-03-14T23:59:59.000Z
Coherent radiation from a relativistic electron beam is a valuable way to overcome the present limitations of conventional lasers and synchrotron radiation light sources. The typical scheme has electrons, directly from a linac, in a single-pass interaction with a laser pulse in the presence of a static undulator magnetic field. We demonstrate that a storage-ring free-electron laser can also achieve harmonic generation (down to 36.5 nm), presenting both experimental and theoretical results, and offer a reliable interpretation of the peculiar underlying physical processes involved.
Origin of second-harmonic generation enhancement in optical split-ring resonators
Ciracì, Cristian; Scalora, Michael; Smith, David R
2012-01-01T23:59:59.000Z
We present a study of the second-order nonlinear optical properties of metal-based metamaterials. A hydrodynamic model for electronic response is used, in which nonlinear surface contributions are expressed in terms of the bulk polarization. The model is in good agreement with published experimental results, and clarifies the mechanisms contributing to the nonlinear response. In particular, we show that the reported enhancement of second-harmonic in split-ring resonator based media is driven by the electric rather than the magnetic properties of the structure.
Life Cycle Greenhouse Gas Emissions of Utility-Scale Wind Power: Systematic Review and Harmonization
Broader source: Energy.gov [DOE]
As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.
Reliability of IGBT in a STATCOM for Harmonic Compensation and Power Factor Correction
Gopi Reddy, Lakshmi Reddy [ORNL; Tolbert, Leon M [ORNL; Ozpineci, Burak [ORNL; Xu, Yan [ORNL; Rizy, D Tom [ORNL
2012-01-01T23:59:59.000Z
With smart grid integration, there is a need to characterize reliability of a power system by including reliability of power semiconductors in grid related applications. In this paper, the reliability of IGBTs in a STATCOM application is presented for two different applications, power factor correction and harmonic elimination. The STATCOM model is developed in EMTP, and analytical equations for average conduction losses in an IGBT and a diode are derived and compared with experimental data. A commonly used reliability model is used to predict reliability of IGBT.
Method and apparatus for reducing the harmonic currents in alternating-current distribution networks
Beverly, Leon H. (Lockport, IL); Hance, Richard D. (Elburn, IL); Kristalinski, Alexandr L. (Naperville, IL); Visser, Age T. (Geneva, IL)
1996-01-01T23:59:59.000Z
An improved apparatus and method reduce the harmonic content of AC line and neutral line currents in polyphase AC source distribution networks. The apparatus and method employ a polyphase Zig-Zag transformer connected between the AC source distribution network and a load. The apparatus and method also employs a mechanism for increasing the source neutral impedance of the AC source distribution network. This mechanism can consist of a choke installed in the neutral line between the AC source and the Zig-Zag transformer.
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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP a gHigh Plains Wind Farm JumpKahului, Hawaii: EnergyKonica Minolta HoldingsKumagaiLABORSTALoading...
Roles of poloidal rotation in the q = 1 high-order harmonic tearing modes in a tokamak plasma
Wei Lai; Wang Zhengxiong [Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)
2013-01-15T23:59:59.000Z
Roles of poloidal rotation in stabilizing the m/n=1/1 kink-tearing mode and exciting its high-order harmonic tearing modes are numerically investigated by using a reduced magnetohydrodynamic model. It is found that the high-order harmonic tearing modes, such as m/n=2/2, m/n=3/3, or even much higher-m harmonics, can be destabilized so significantly by rotation shear as to be more unstable than or comparable to the m/n=1/1 mode. Moreover, the short wave-length Kelvin- Helmholtz (KH) instabilities can be excited in the large rotation shear regime. The scaling power laws of the linear growth rate for each harmonic mode in different rotation shear regimes are verified by the previous relevant theoretical results based on the non-constant-{psi} and constant-{psi} behavior categories in tearing modes. During the nonlinear evolution, the m/n=2/2 mode dominated phase first appears and then is followed by the m/n=1/1 mode dominated nonlinear phase instead. Afterward, some smaller sub-islands due to the high-order harmonics are produced in the large irregular m=1 crescent-shaped island, and then a coalescence process of turbulent island chains occurs before the decay phase.
Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D
Jay L. Hirshfield
2012-07-26T23:59:59.000Z
Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.
Heger, Matthias; Suhm, Martin A.; Mata, Ricardo A., E-mail: rmata@gwdg.de [Georg-August-Universität Göttingen, Institut für Physikalische Chemie, Tammannstr. 6, 37077 Göttingen (Germany)
2014-09-14T23:59:59.000Z
The discrepancy between experimental and harmonically predicted shifts of the OH stretching fundamental of methanol upon hydrogen bonding to a second methanol unit is too large to be blamed mostly on diagonal and off-diagonal anharmonicity corrections. It is shown that a decisive contribution comes from post-MP2 electron correlation effects, which appear not to be captured by any of the popular density functionals. We also identify that the major deficiency is in the description of the donor OH bond. Together with estimates for the electronic and harmonically zero-point corrected dimer binding energies, this work provides essential constraints for a quantitative description of this simple hydrogen bond. The spectroscopic dissociation energy is predicted to be larger than 18 kJ/mol and the harmonic OH-stretching fundamental shifts by about ?121 cm{sup ?1} upon dimerization, somewhat more than in the anharmonic experiment (?111 cm{sup ?1})
Interaction between O{sub 2} and ZnO films probed by time-dependent second-harmonic generation
Andersen, S. V., E-mail: sva@nano.aau.dk [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg Øst (Denmark); Vandalon, V.; Bosch, R. H. E. C.; Loo, B. W. H. van de; Kessels, W. M. M., E-mail: w.m.m.kessels@tue.nl [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Pedersen, K. [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, DK-9220 Aalborg Øst (Denmark)
2014-02-03T23:59:59.000Z
The interaction between O{sub 2} and ZnO thin films prepared by atomic layer deposition has been investigated by time-dependent second-harmonic generation, by probing the electric field induced by adsorbed oxygen molecules on the surface. The second-harmonic generated signal decays upon laser exposure due to two-photon assisted desorption of O{sub 2}. Blocking and unblocking the laser beam for different time intervals reveals the adsorption rate of O{sub 2} onto ZnO. The results demonstrate that electric field induced second-harmonic generation provides a versatile non-contact probe of the adsorption kinetics of molecules on ZnO thin films.
Many interacting fermions in a one-dimensional harmonic trap: a quantum-chemical treatment
Tomasz Grining; Micha? Tomza; Micha? Lesiuk; Micha? Przybytek; Monika Musia?; Pietro Massignan; Maciej Lewenstein; Robert Moszynski
2015-08-16T23:59:59.000Z
We employ ab initio methods of quantum chemistry to investigate spin-1/2 fermions interacting via a two-body contact potential in a one-dimensional harmonic trap. The convergence of the total energy with the size of the one-particle basis set is analytically investigated for the two-body problem and the same form of the convergence formula is numerically confirmed to be valid for the many-body case. Benchmark calculations for two to six fermions with the full configuration interaction method, equivalent to the exact diagonalization approach, and the coupled cluster method including single, double, triple, and quadruple excitations are presented. The convergence of the correlation energy with the level of excitations included in the coupled cluster model is analyzed. The range of the interaction strength for which single-reference coupled cluster methods work is examined. Next, the coupled cluster method restricted to single, double, and noniterative triple excitations, CCSD(T), is employed to study a two-component Fermi gas composed of 6 to 80 atoms in a one-dimensional harmonic trap. The density profiles of trapped atomic clouds are also reported. Finally, a comparison with experimental results for few-fermion systems is presented. Upcoming possible applications and extensions of the presented approach are discussed.
Bertelli, N [PPPL; Jaeger, E F; Hosea, J C; Phillips, C K; Berry, L; Bonoli, P T; Gerhardt, S P [PPPL; Green, D; LeBlanc, B [PPPL; Perkins, R J; Ryan, P M; Taylor, G; Valeo, E J; Wilso, J R; Wright, J C
2014-07-01T23:59:59.000Z
Fast waves at harmonics of the ion cyclotron frequency, which have been used successfully on National Spherical Torus Experiment (NSTX), will also play an important role in ITER and are a promising candidate for the Fusion Nuclear Science Facility (FNSF) designs based on spherical torus (ST). Experimental studies of high harmonic fast waves (HHFW) heating on the NSTX have demonstrated that substantial HHFW power loss occurs along the open field lines in the scrape-off layer (SOL), but the mechanism behind the loss is not yet understood. The full wave RF code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain, is applied to specific NSTX discharges in order to predict the effects and possible causes of this power loss. In the studies discussed here, a collisional damping parameter has been implemented in AORSA as a proxy to represent the real, and most likely nonlinear, damping processes. A prediction for the NSTX Upgrade (NSTX-U) experiment, that will begin operation next year, is also presented, indicating a favorable condition for the experiment due to a wider evanescent region in edge density.*Research supported by the U.S. DOE under Contract No. DE-AC02-09CH11466 with Princeton University.
Extension of harmonic cutoff in a multicycle chirped pulse combined with a chirp-free pulse
Xu Junjie; Zeng Bin; Yu Yongli [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)
2010-11-15T23:59:59.000Z
We demonstrate high-order harmonic generation in a wave form synthesized by a multicycle 800-nm chirped laser pulse and a chirp-free laser pulse. Compared with the case of using only a chirped pulse, both the harmonic cutoff and the extreme ultraviolet supercontinuum can be extended when a weak chirp-free pulse is combined with the chirped pulse. When chirp-free pulse intensity grows, the cutoff energy and bandwidth of the supercontinuum grow as well. It is found that the broad supercontinuum can be achieved for a driving pulse with long duration even though the driving pulse reaches 10 optical cycles. An isolated attosecond pulse with duration of about 59 as is obtained, and after appropriate phase compensation with a duration of about 11 as. In addition, by performing time-frequency analyses and the classical trajectory simulation, the difference in supercontinuum generation between the preceding wave form and a similar wave form synthesized by an 800-nm fundamental pulse and a 1600-nm subharmonic pulse is investigated.
Grids of stellar models including second harmonic and colours: Solar composition
Yildiz, Mutlu
2015-01-01T23:59:59.000Z
Grids of stellar evolution are required in many fields of astronomy/astrophysics, such as planet hosting stars, binaries, clusters, chemically peculiar stars, etc. In this study, a grid of stellar evolution models with updated ingredients and {recently determined solar abundaces} is presented. The solar values for the initial abundances of hydrogen, heavy elements and mixing-length parameter are 0.0172, 0.7024 and 1.98, respectively. The mass step is small enough (0.01 M$_\\odot$) that interpolation for a given star mass is not required. The range of stellar mass is 0.74 to 10.00 M$_\\odot$. We present results in different forms of tables for easy and general application. The second stellar harmonic, required for analysis of apsidal motion of eclipsing binaries, is also listed. We also construct rotating models to determine effect of rotation on stellar structure and derive fitting formula for luminosity, radius and the second stellar harmonic as a function of rotational parameter. We also compute and list colo...
Analytical modeling of pulse-pileup distortion using the true pulse shape; applications to Fermi-GBM
Vandiver Chaplin; Narayana Bhat; Michael Briggs; Valerie Connaughton
2013-04-29T23:59:59.000Z
Pulse-pileup affects most photon counting systems and occurs when photon detections occur faster than the detector's registration and recovery time. At high input rates, shaped pulses interfere and the source spectrum, as well as intensity information, get distorted. For instruments using bipolar pulse shaping there are two aspects to consider: `peak' and `tail' pileup effects, which raise and lower the measured energy, respectively. Peak effects have been extensively modeled in the past. Tail effects have garnered less attention due to the increased complexity: bipolar tails mean the tail pulse-height measurement depends on events in more than one time interval. We leverage previous work to derive an accurate, semi-analytical prediction for peak and tail pileup, up to high orders. We use the true pulse shape from the detectors of the Fermi Gamma-ray Burst Monitor. The measured spectrum is calculated by writing exposure time as a state-space expansion of overlapping pileup states and is valid up to very high rates. This expansion models losses due to fixed and extendable deadtime by averaging overlap configurations. Additionally, the model correctly predicts energy-dependent losses due to tail subtraction (sub-threshold) effects. We discuss pileup losses in terms of the true rate of photon detections versus the recorded count rate.
Burkhardt, J. J.; Heath, G.; Cohen, E.
2012-04-01T23:59:59.000Z
In reviewing life cycle assessment (LCA) literature of utility-scale concentrating solar power (CSP) systems, this analysis focuses on reducing variability and clarifying the central tendency of published estimates of life cycle greenhouse gas (GHG) emissions through a meta-analytical process called harmonization. From 125 references reviewed, 10 produced 36 independent GHG emissions estimates passing screens for quality and relevance: 19 for parabolic trough (trough) technology and 17 for power tower (tower) technology. The interquartile range (IQR) of published estimates for troughs and towers were 83 and 20 grams of carbon dioxide equivalent per kilowatt-hour (g CO2-eq/kWh),1 respectively; median estimates were 26 and 38 g CO2-eq/kWh for trough and tower, respectively. Two levels of harmonization were applied. Light harmonization reduced variability in published estimates by using consistent values for key parameters pertaining to plant design and performance. The IQR and median were reduced by 87% and 17%, respectively, for troughs. For towers, the IQR and median decreased by 33% and 38%, respectively. Next, five trough LCAs reporting detailed life cycle inventories were identified. The variability and central tendency of their estimates are reduced by 91% and 81%, respectively, after light harmonization. By harmonizing these five estimates to consistent values for global warming intensities of materials and expanding system boundaries to consistently include electricity and auxiliary natural gas combustion, variability is reduced by an additional 32% while central tendency increases by 8%. These harmonized values provide useful starting points for policy makers in evaluating life cycle GHG emissions from CSP projects without the requirement to conduct a full LCA for each new project.
Observation of spectral gain narrowing in a high-order harmonic seeded soft-x-ray amplifier
Tissandier, F.; Sebban, S.; Ribiere, M.; Gautier, J.; Zeitoun, Ph.; Lambert, G.; Barszczak Sardinha, A.; Goddet, J.-Ph.; Burgy, F.; Lefrou, T.; Valentin, C.; Rousse, A.; Guilbaud, O.; Klisnick, A.; Nejdl, J.; Mocek, T.; Maynard, G. [Laboratoire d'Optique Appliquee, ENSTA Paristech/Ecole Polytechnique/CNRS UMR 7639, F-91761 Palaiseau Cedex (France); Laboratoire d'Interaction du Rayonnement X Avec la Matiere, Universite Paris Sud/CNRS UMR 8624, F-91495 Orsay Cedex (France); Department of X-ray Lasers, Institute of Physics, Na Slovance 2, CZ-182 21 Prague 8 (Czech Republic); Laboratoire de Physique des Gaz et des Plasmas, Universite Paris Sud/CNRS UMR 8578, F-91405 Orsay Cedex (France)
2010-06-15T23:59:59.000Z
We report an observation of spectral gain narrowing of a high-order harmonic amplified by a soft-x-ray optical-field-ionized plasma. The temporal coherence and spectral linewidth of both the seeded and unseeded soft-x-ray lasers were experimentally measured using a varying-path-difference interferometer. The results showed that the high-order harmonic is subject to a strong spectral narrowing during its propagation in the plasma amplifier without rebroadening at saturation. This is in good agreement with a radiative transfer calculation including gain narrowing and saturation rebroadening.
R. Arcos-Olalla; M. A. Reyes; H. C. Rosu
2012-09-20T23:59:59.000Z
We introduce an alternative factorization of the Hamiltonian of the quantum harmonic oscillator which leads to a two-parameter self-adjoint operator from which the standard harmonic oscillator, the one-parameter oscillators introduced by Mielnik, and the Hermite operator are obtained in certain limits of the parameters. In addition, a single Bernoulli-type parameter factorization which is different of the one introduced by M. A. Reyes, H. C. Rosu, and M. R. Gutierrez, Phys. Lett. A 375 (2011) 2145 is briefly discussed in the final part of this work
Buckley, Sonia; Hatami, Fariba; Vuckovic, Jelena
2012-01-01T23:59:59.000Z
Indistinguishable single photons are necessary for quantum information processing applications. Resonant or quasiresonant excitation of single quantum dots provides greater single photon indistinguishability than incoherent pumping, but is also more challenging experimentally. Here, we demonstrate high signal to noise quasiresonant excitation of InP/InGaP quantum dots. The excitation is provided via second harmonic generated from a telecommunications wavelength laser resonant with the fundamental mode of a photonic crystal cavity, fabricated at twice the quantum dot transition wavelength. The second harmonic is generated using the \\chi(2) nonlinearity of the InGaP material matrix.
Sonia Buckley; Kelley Rivoire; Fariba Hatami; Jelena Vuckovic
2012-10-03T23:59:59.000Z
Indistinguishable single photons are necessary for quantum information processing applications. Resonant or quasiresonant excitation of single quantum dots provides greater single photon indistinguishability than incoherent pumping, but is also more challenging experimentally. Here, we demonstrate high signal to noise quasiresonant excitation of InP/InGaP quantum dots. The excitation is provided via second harmonic generated from a telecommunications wavelength laser resonant with the fundamental mode of a photonic crystal cavity, fabricated at twice the quantum dot transition wavelength. The second harmonic is generated using the \\chi(2) nonlinearity of the InGaP material matrix.
Saeta, Peter N.
Harmonic Generation in Thin Films and Multilayers William S. Kolthammer, Dustin Barnard, Nicole, Claremont, CA 91711 (Dated: September 6, 2004) A general method for computing harmonic generation plane waves and treats har- monic generation in the parametric approximation. The method is applied
Gopalan, Venkatraman
Temperature dependent blue second harmonic generation in Ba5Li2Ti2Nb8O30 microcrystals embedded of the polar phase Ba5Li2Ti2Nb8O30 (BLTN). Blue (400 nm) second harmonic generation (SHG) was observed in transmission mode when 800 nm laser light was allowed to pass through the individual crystallites. The blue SHG
Naumov, A. N.; Zheltikov, A. M.; Fedotov, A. B.; Sidorov-Biryukov, D. A.; Tarasevitch, A. P.; Zhou, Ping; von der Linde, D.
2001-06-01T23:59:59.000Z
High-order harmonic generation in a hollow fiber filled with a weakly ionizing gas is theoretically analyzed within the framework of the slowly varying envelope approximation. The gas pressure that corresponds to maximum efficiency of frequency conversion, the absorption coefficient, the phase mismatch owing to gas dispersion, and the enhancement of harmonic-generation efficiency owing to waveguide phase matching are estimated for 27th-harmonic generation in hollow fibers filled with helium, neon, argon, krypton, or xenon. As a result of the ionization-induced self-phase modulation of the pump pulse in a hollow fiber filled with a weakly ionizing gas, the phase mismatch changes within the pump pulse, decreasing the overall efficiency of harmonic generation and making the harmonic-generation efficiency less sensitive to the gas pressure in the hollow fiber. {copyright} 2001 Optical Society of America
Thuvander, A.; Melander, A.; Lind, M.; Lior, N.; Bark, F.H.
1999-07-01T23:59:59.000Z
The primary objectives of this study are to model the nature of the complex high-turbulence quenching cooling-gas flow, and to examine its effects on the resulting distortions and mechanical properties of the quenched piece, here bearing steel tubes and solid cylinders. A {kappa}-{epsilon} turbulent flow and heat transfer model adopted was found to predict the convective heat transfer coefficient (h) distribution reasonably well for Reynolds number up to about (0.3)10{sup 6}. At higher Reynolds number (to 10{sup 6}) it still predicts the nature of the flow well, but overpredicts h by up to 100% in the transition zone. The distributions of h around the body surface were used as the boundary condition for computing the temperature distribution history, phase transformations, distortions and mechanical properties of the quenched bodies. Increasing variation in h was found to increase the probability of large out-of-roundness, and nonuniformity in the properties.
Aczel, Adam A [ORNL; Bugaris, Dan [University of South Carolina; Li, Ling [University of Tennessee, Knoxville (UTK); Yan, Jiaqiang [ORNL; Dela Cruz, Clarina R [ORNL; Zur Loye, Hans-Conrad [University of South Carolina; Nagler, Stephen E [ORNL
2013-01-01T23:59:59.000Z
The usual classical behaviour of S = 3/2, B-site ordered double perovskites generally results in simple, commensurate magnetic ground states. In contrast, heat capacity and neutron powder diffraction measurements for the S = 3/2 systems La2NaB'O6 (B = Ru, Os) reveal an incommensurate magnetic ground state for La2NaRuO6 and a drastically suppressed ordered moment for La2NaOsO6. This behaviour is attributed to the large monoclinic structural distortions of these double perovskites. The distortions have the effect of weakening the nearest neighbour superexchange interactions, presumably to an energy scale that is comparable to the next nearest neighbour superexchange. The exotic ground states in these materials can then arise from a competition between these two types of antiferromagnetic interactions, providing a novel mechanism for achieving frustration in the double perovskite family.
Du, Yingge; Gu, Meng; Varga, Tamas; Wang, Chong M.; Bowden, Mark E.; Chambers, Scott A.
2014-08-27T23:59:59.000Z
In this paper, we show that compared 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 accommodate interfacial strain, which in turn strongly impact the nucleation, structure, and defect formation during the epitaxial growth of WO3 on SrTiO3(001). A meta-stable tetragonal phase can be stabilized by epitaxy and a thickness dependent phase transition (tetragonal to monoclinic) is observed. In contrast to misfit dislocations to accommodate the interfacial stain, the facial WO6 octahedral distortion and tilting give rise to three types of planar defects that affect more than 15 monolayers from the interface. These atomically resolved, unusual interfacial defects may significantly alter the electronic, electrochromic, and mechanical properties of the epitaxial films.
A grid-connected photovoltaic power conversion system with single-phase multilevel inverter
Beser, Ersoy; Arifoglu, Birol; Camur, Sabri; Beser, Esra Kandemir [Department of Electrical Engineering, Kocaeli University (Turkey)
2010-12-15T23:59:59.000Z
This paper presents a grid-connected photovoltaic (PV) power conversion system based on a single-phase multilevel inverter. The proposed system fundamentally consists of PV arrays and a single-phase multilevel inverter structure. First, configuration and structural parts of the PV assisted inverter system are introduced in detail. To produce reference output voltage waves, a simple switching strategy based on calculating switching angles is improved. By calculated switching angles, the reference signal is produced as a multilevel shaped output voltage wave. The control algorithm and operational principles of the proposed system are explained. Operating PV arrays in the same load condition is a considerable point; therefore a simulation study is performed to arrange the PV arrays. After determining the number and connection types of the PV arrays, the system is configured through the arrangement of the PV arrays. The validity of the proposed system is verified through simulations and experimental study. The results demonstrate that the system can achieve lower total harmonic distortion (THD) on the output voltage and load current, and it is capable of operating synchronous and transferring power values having different characteristic to the grid. Hence, it is suitable to use the proposed configuration as a PV power conversion system in various applications. (author)
Wallace, J.F.; Schwam, D. [Case Western Reserve Univ., Cleveland, OH (United States)
1995-03-01T23:59:59.000Z
Optimum heat treatment of dies (quenching) is critical in ensuring satisfactory service performance: rapid cooling rates increase the thermal fatigue/heat checking resistance of the steel, although very fast cooling rates can also lead to distortion and lower fracture toughness, increasing the danger of catastrophic fracture. Goal of this project is to increase die life by using fast enough quenching rates (> 30 F/min ave cooling rate from 1750 to 550 F, 1/2 in. below working surfaces) to obtain good toughness and fatigue resistance in Premium grade H-13 steel dies. An iterative approach of computer modeling validated by experiment was taken. Cooling curves during gas quenching of H-13 blocks and die shapes were measured under 2, 5, and 7.5 bar N2 and 4 bar Ar. Resulting dimensional changes and residual stresses were determined. To facilitate the computer modeling work, a database of H-13 mechanical and physical properties was compiled. Finite element analysis of the heat treated shapes was conducted. Good fit of modeled vs measured quenched rates was demonstrated for simple die shapes. The models predict well the phase transformation products from the quench. There is good fit between predicted and measured distortion contours; however magnitude of predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required.
Transportation Market Distortions
Litman, Todd
2006-01-01T23:59:59.000Z
petroleum producers are given signi?cant tax exemp- tions and subsidies (Litman 2005). Business and income
Tolbert, Leon M.
Real Time Selective Harmonic Minimization for Multilevel Inverters Connected to Solar Panels Using varying DC input sources. Five 195 W solar panels were used as the DC source for each full bridge cells or solar panels and will consequently bring a voltage unbalance depending on the system dynamics
Martin, Jan M.L.
First principles computation of thermochemical properties beyond the harmonic approximation. I of thermochemical data for molecules and reactions hardly needs to be stressed. Compilations like the JANAF tables' list free energy functions, entropies, enthalpies, and molar heats as a function of temperature from
Nabben, Reinhard
-harmonic eddy current model in two dimensions. The first criterion is the robustness with respect Expansions, Eddy- current model AMS subject classifications. 65N30, 35C20, 35J25, 41A60, 35B40, 78M30, 78M35 Introduction. For simulations of the eddy current problem with thin sheets by standard methods, like the finite
Performance study of a soft X-ray harmonic generation FEL seeded with an EUV laser pulse
Wurtele, Jonathan
Performance study of a soft X-ray harmonic generation FEL seeded with an EUV laser pulse M. Gullans electron laser (FEL) using a low-power extreme ultraviolet (EUV) pulse as an input seed is investigated generation schemes. It is found that, for reasonable beam parameters, robust FEL performance can be obtained
Tolbert, Leon M.
to the fact that several batteries, fuel cells, solar cell, wind, and microturbines can be connected through Vao Fuel Cell Module a o Fuel Cell Module Fuel Cell Module Q11 D11 Q12 D12 Q13 D13Q14 D14 Q21 Q22 D22Harmonic Optimization of Multilevel Converters Using Genetic Algorithms Abstract-- In this paper
Fujimoto, Hiroshi
stator windings. Permanent- magnet Concentrated winding 29.3 30.5 55.3 26.0 4.0 d-axis: q-axis: 1-59 #12 a spatial-harmonics based estimation method of rotor position of an IPM motor with concentrated stator windings. The method utilizes voltage command ripples caused by variations of inductance to estimate
Tolbert, Leon M.
of solar cells are dc voltages, and if this energy is to be fed to into an ac power grid, a powerThe Use of Power Sums to Solve the Harmonic Elimination Equations for Multilevel Converters EPE electronic interface is required. A multilevel inverter is ideal for connecting such distributed dc energy
Eisenthal, Kenneth B.
Protonation at the Aqueous Interface of Polymer Nanoparticles with Second Harmonic Generation reaction of the carboxyl (-COOH) functional group fixed at the surface of polystyrene carboxylate (PSC for the PSC colloidal particles, which corresponds to a decrease in the acidity; that is, Ka is a factor of 4
Determination of the effect of harmonics on pipe-type power cable AC/DC resistance ratio
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 (United States))
1993-03-01T23:59:59.000Z
This paper presents a closed form expression to compute the AC/CD resistance ratio of HPFF (High Pressure Fluid Filled) pipe-type cable in the presence of harmonics. Industry currently computes this factor, which is a significant part in assessing the current carrying capacity of a system, with the assumption that the currents are purely sinusoidal at 60 Hz. However, as levels of harmonics increase on power systems, concern for the effect of harmonics on system ampacities rises, and that effect has already been discussed for distribution systems. This paper develops a closed form hybrid of the resistance ratio equations presented by Neher and McGrath, and compares the results with measured data at 60 Hz. At present there is no measured data available for the resistance ratio at higher frequencies, so a two dimensional finite element model is developed to view the effect of frequency on the resistance ratio. A discussion is given on the effect of a specific harmonics scenario on the resistance ratio of a given system, and results are presented for some example systems. The paper also discusses the validity and characteristics of each method.
Sub-Millimetre Wave Sub-Harmonically Pumped Image-Rejection Schottky Mixers for STEAM-R
Sub-Millimetre Wave Sub-Harmonically Pumped Image- Rejection Schottky Mixers for STEAM-R S. P. Rea = 343.5 - 355.5 GHz switch The PREMIER Mission The STEAM-R Instrument PREMIER (PRocess Exploration-sounder (MWLS) on the same satellite platform. The MWLS is the latest iteration of the STEAM-R instrument
Fridley, David; Lin, Jiang; Denver, Andrea; Biermayer, Peter; Dillavou, Tyler
2005-07-20T23:59:59.000Z
This report examines critical differences among energy-efficient labeling programs for CFLs in Brazil, China, the United States, and the seven members of the international Efficient Lighting Initiative (ELI) in terms of technical specifications and test procedures, and review issues related to international harmonization of these standards.
in a SiOx matrix, with femtosecond laser pulses at 800 nm. A remarkable melting-induced enhancementMelting-Induced Enhancement of the Second-Harmonic Generation from Metal Nanoparticles A. M [3]. While consid- erable efforts have been mainly focused on selection of new materials
Popovic, Zoya
High-Efficiency Harmonically-Terminated Rectifier for Wireless Powering Applications Michael Roberg of Colorado, Boulder, CO, 80309-0425 Abstract-In wireless powering, the rectifier efficiency has a large effect on overall system efficiency. This paper presents an approach to high-efficiency microwave
Part-per-million gas detection from long-baseline THz spectroscopy S. A. Harmon and R. A. Chevillea)
Part-per-million gas detection from long-baseline THz spectroscopy S. A. Harmon and R. A. Chevillea on a White cell design capable of detecting gas species in the low part-per-million range in near real time length at pressures down to 1 Pa. Both phase sensitive (lock-in) detection and direct signal averaging
Analytic model of bunched beams for harmonic generation in the low-gain free electron laser regime
Wurtele, Jonathan
Analytic model of bunched beams for harmonic generation in the low-gain free electron laser regime employs free electron lasers (FELs) with two undulators: the first uses a seed laser to modulate Many proposed x-ray free electron lasers (FELs) are designed to produce radiation starting from
Soft Harmonic Masks for Recognising Speech in the Presence of a Competing Andre Coy and Jon Barker
Barker, Jon
energy cannot be reliably labelled as either one source or the other. This typically happens whenSoft Harmonic Masks for Recognising Speech in the Presence of a Competing Speaker Andr´e Coy of recognising speech in the presence of a competing speaker. It uses a two stage `Speech Fragment Decoding
Far-reaching statistical consequences of the zero-point energy for the harmonic oscillator
Luis de la Pena; Andrea Valdes-Hernandez; Ana Maria Cetto
2007-12-12T23:59:59.000Z
In a recent thermodynamic analysis of the harmonic oscillator and using an interpolation procedure, Boyer has shown that the existence of a zero-point energy leads to the Planck spectrum. Here we avoid the interpolation by adding a statistical argument to arrive at Planck's law as an inescapable result of the presence of the zero-point energy. No explicit quantum argument is introduced along the derivations. We disclose the connection of our results with the original analysis of Planck and Einstein, which led to the notion of the quantized radiation field. We then inquire into the discrete or continuous behaviour of the energy and pinpoint the discontinuities. Finally, to open the door to the description of the zero-point fluctuations, we briefly discuss the statistical (in contrast to the purely thermodynamic) description of the oscillator, which accounts for both thermal and temperature-independent contributions to the energy dispersion.
Nakai, Hiromi, E-mail: nakai@waseda.jp [Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); ESICB, Kyoto University, Kyotodaigaku-Katsura, Kyoto 615-8520 (Japan); Ishikawa, Atsushi [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); ESICB, Kyoto University, Kyotodaigaku-Katsura, Kyoto 615-8520 (Japan)
2014-11-07T23:59:59.000Z
We propose a novel quantum chemical method, called the harmonic solvation model (HSM), for calculating thermochemical parameters in the condensed phase, particularly in the liquid phase. The HSM represents translational and rotational motions of a solute as vibrations interacting with a cavity wall of solvent molecules. As examples, the HSM and the ideal-gas model (IGM) were used for the standard formation reaction of liquid water, combustion reactions of liquid formic acid, methanol, and ethanol, vapor–liquid equilibration of water and ethanol, and dissolution of gaseous CO{sub 2} in water. The numerical results confirmed the reliability and applicability of the HSM. In particular, the temperature dependence of the Gibbs energy of liquid molecules was accurately reproduced by the HSM; for example, the boiling point of water was reasonably determined using the HSM, whereas the conventional IGM treatment failed to obtain a crossing of the two Gibbs energy curves for gaseous and liquid water.
Chandrasekar, Rohith; Lagutchev, Alexei; Shalaev, Vladimir M; Ciraci, Cristian; Smith, David R; Kildishev, Alexander V
2015-01-01T23:59:59.000Z
Plasmonic resonances in metallic nanostructures have been shown to drastically enhance local electromagnetic fields, and thereby increase the efficiency of nonlinear optical phenomena, such as second harmonic generation (SHG). While it has been experimentally observed that enhanced fields can significantly boost SHG, to date it proved difficult to probe electrical and magnetic resonances in one and the same nanostructure. This however is necessary to directly compare relative contributions of electrical and magnetic components of SHG enhancement. In this paper we report an experimental study of a metasurface capable of providing electrical and magnetic resonant SHG enhancement for TM polarization. Our metasurface could be engineered such that the peak frequencies of electrical and magnetic resonances could be adjusted independently. We used this feature to distinguish their relative contributions. Experimentally it was observed that the magnetic resonance provides only 50% as much enhancement to SHG as compar...
A high-order harmonic generation apparatus for time- and angle-resolved photoelectron spectroscopy
Frietsch, B.; Gahl, C.; Teichmann, M.; Weinelt, M. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany)] [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Carley, R. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany) [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Döbrich, K. [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany)] [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Schwarzkopf, O.; Wernet, Ph. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)
2013-07-15T23:59:59.000Z
We present a table top setup for time- and angle-resolved photoelectron spectroscopy to investigate band structure dynamics of correlated materials driven far from equilibrium by femtosecond laser pulse excitation. With the electron-phonon equilibration time being in the order of 1–2 ps it is necessary to achieve sub-picosecond time resolution. Few techniques provide both the necessary time and energy resolution to map non-equilibrium states of the band structure. Laser-driven high-order harmonic generation is such a technique. In our experiment, a grating monochromator delivers tunable photon energies up to 40 eV. A photon energy bandwidth of 150 meV and a pulse duration of 100 fs FWHM allow us to cover the k-space necessary to map valence bands at different k{sub z} and detect outer core states.
Cavity-enhanced second harmonic generation via nonlinear-overlap optimization
Lin, Zin; Loncar, Marko; Johnson, Steven G; Rodriguez, Alejandro W
2015-01-01T23:59:59.000Z
We describe an approach based on topology optimization that enables automatic discovery of wavelength-scale photonic structures for achieving high-efficiency second-harmonic generation (SHG). A key distinction from previous formulation and designs that seek to maximize Purcell factors at individual frequencies is that our method not only aims to achieve frequency matching (across an entire octave) and large radiative lifetimes, but also optimizes the equally important nonlinear--coupling figure of merit $\\bar{\\beta}$, involving a complicated spatial overlap-integral between modes. We apply this method to the particular problem of optimizing micropost and grating-slab cavities (one-dimensional multilayered structures) and demonstrate that a variety of material platforms can support modes with the requisite frequencies, large lifetimes $Q \\gtrsim 10^3$, small modal volumes $\\sim (\\lambda/n)^3$, and extremely large $\\bar{\\beta} \\gtrsim 10^{-2}$, orders of magnitude larger than the state of the art.
Kinetic freeze-out, particle spectra and harmonic flow coefficients from mode-by-mode hydrodynamics
Stefan Floerchinger; Urs Achim Wiedemann
2014-08-27T23:59:59.000Z
The kinetic freeze-out for the hydrodynamical description of relativistic heavy ion collisions is discussed using a background-fluctuation splitting of the hydrodynamical fields. For a single event, the particle spectrum, or its logarithm, can be written as the sum of background part that is symmetric with respect to azimuthal rotations and longitudinal boosts and a part containing the contribution of fluctuations or deviations from the background. Using a complete orthonormal basis to characterize the initial state allows one to write the double differential harmonic flow coefficients determined by the two-particle correlation method as matrix expressions involving the initial fluid correlations. We discuss the use of these expressions for a mode-by-mode analysis of fluctuating initial conditions in heavy ion collisions.
Exact Analysis of the Adiabatic Invariants in Time-Dependent Harmonic Oscillator
Marko Robnik; Valery G. Romanovski
2005-06-16T23:59:59.000Z
The theory of adiabatic invariants has a long history and important applications in physics but is rarely rigorous. Here we treat exactly the general time-dependent 1-D harmonic oscillator, $\\ddot{q} + \\omega^2(t) q=0$ which cannot be solved in general. We follow the time-evolution of an initial ensemble of phase points with sharply defined energy $E_0$ and calculate rigorously the distribution of energy $E_1$ after time $T$, and all its moments, especially its average value $\\bar{E_1}$ and variance $\\mu^2$. Using our exact WKB-theory to all orders we get the exact result for the leading asymptotic behaviour of $\\mu^2$.
Electro-optic harmonic conversion to switch a laser beam out of a cavity
Haas, R.A.; Henesian, M.A.
1984-10-19T23:59:59.000Z
The present invention relates to switching laser beams out of laser cavities, and more particularly, it relates to the use of generating harmonics of the laser beam to accomplish the switching. When laser light is generatd in a laser cavity the problem arises of how to switch the laser light out of the cavity in order to make use of the resulting laser beam in a well known multitude of ways. These uses include range finding, communication, remote sensing, medical surgery, laser fusion applications and many more. The switch-out problem becomes more difficult as the size of the laser aperture grows such as in laser fusion applications. The final amplifier stages of the Nova and Novette lasers at Lawrence Livermore National Laboratory are 46 centimeters with the laser beam expanded to 74 centimeters thereafter. Larger aperture lasers are planned.
Chen, Bao-Qin; Zhang, Chao; Liu, Rong-Juan; Li, Zhi-Yuan, E-mail: lizy@aphy.iphy.ac.cn [Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China)
2014-10-13T23:59:59.000Z
We have designed and fabricated a lithium niobate (LN) nonlinear photonic crystal (NPC) with a two-dimensional (2D) ellipse structure of inverse poling domains. The structure can offer continuously varying reciprocal lattice vectors in different directions to compensate the phase-mismatching during the second harmonic generation (SHG) for diverse pump wavelengths. We consider three propagation directions with large effective nonlinear susceptibility and measure the nonlinear conversion efficiency of SHG. The experimental data are in good agreement with the quantitative calculation results using the effective susceptibility model with pump depletion. With high-efficiency SHG in multiple propagation direction, the 2D ellipse structure of LN NPC has the potential to realize various broadband nonlinear frequency conversion processes in different propagation direction with a single crystal.
Dual harmonic Kelvin probe force microscopy at the graphene–liquid interface
Collins, Liam; Rodriguez, Brian J., E-mail: brian.rodriguez@ucd.ie [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Kilpatrick, Jason I.; Weber, Stefan A. L. [Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Vlassiouk, Ivan V. [Energy and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Tselev, Alexander; Jesse, Stephen; Kalinin, Sergei V. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
2014-03-31T23:59:59.000Z
Kelvin probe force microscopy (KPFM) is a powerful technique for the determination of the contact potential difference (CPD) between an atomic force microscope tip and a sample under ambient and vacuum conditions. However, for many energy storage and conversion systems, including graphene-based electrochemical capacitors, understanding electrochemical phenomena at the solid–liquid interface is paramount. Despite the vast potential to provide fundamental insight for energy storage materials at the nanoscale, KPFM has found limited applicability in liquid environments to date. Here, using dual harmonic (DH)-KPFM, we demonstrate CPD imaging of graphene in liquid. We find good agreement with measurements performed in air, highlighting the potential of DH-KPFM to probe electrochemistry at the graphene–liquid interface.
Biswanath Rath
2015-05-19T23:59:59.000Z
For the first time in the literature of Quantum Physics, we present complex energy eigenvalues of non-Hermitian Harmonic Oscillator $H=\\frac{(p+iLx)}^{2}}{2} + W^{2} \\frac{x^{2}}{2}$ with real wave function having positive frequency of vibration $(w)$ under some selective choice of $L$ and $W$ .Interestingly for the same values of $L$ and $W$, if the frequency of vibration $w$ in the real wave function is (some how) related as $w=L\\pmW$ or $w=W-L$ then the same oscillator can reflect either pure positive or negative energy eigenvalues.The real energy levels are in conformity with the perturbative calculation. PACS :03.65.Db;11.39.Er. Key words: Positive frequency, real wave function, complex energy, real positive energy,negative energy.
Sandhu, Gurpreet Kaur, E-mail: Gurpreet.Sandhu2@albertahealthservices.ca [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta (Canada); Dunscombe, Peter [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta (Canada); Department of Oncology, Faculty of Medicine, University of Calgary, Calgary, Alberta (Canada); Meyer, Tyler [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta (Canada); Pavamani, Simon [Department of Oncology, Faculty of Medicine, University of Calgary, Calgary, Alberta (Canada); Department of Radiation Oncology, Christian Medical College, Vellore (India); Khan, Rao [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta (Canada); Department of Oncology, Faculty of Medicine, University of Calgary, Calgary, Alberta (Canada)
2012-01-01T23:59:59.000Z
Purpose: The objective of this study was to compare the relative utility of tissue harmonic (H) and brightness (B) transrectal ultrasound (TRUS) images of the prostate by studying interobserver and intraobserver variation in prostate delineation. Methods and Materials: Ten patients with early-stage disease were randomly selected. TRUS images of prostates were acquired using B and H modes. The prostates on all images were contoured by an experienced radiation oncologist (RO) and five equally trained observers. The observers were blinded to information regarding patient and imaging mode. The volumes of prostate glands and areas of midgland slices were calculated. Volumes contoured were compared among the observers and between observer group and RO. Contours on one patient were repeated five times by four observers to evaluate the intraobserver variability. Results: A one-sample Student t-test showed the volumes outlined by five observers are in agreement (p > 0.05) with the RO. Paired Student t-test showed prostate volumes (p = 0.008) and midgland areas (p = 0.006) with H mode were significantly smaller than that with B mode. Two-factor analysis of variances showed significant interobserver variability (p < 0.001) in prostate volumes and areas. Inter- and intraobserver consistency was quantified as the standard deviation of mean volumes and areas, and concordance indices. It was found that for small glands ({<=}35 cc) H mode provided greater interobserver consistency; however, for large glands ({>=}35 cc), B mode provided more consistent estimates. Conclusions: H mode provided superior inter- and intraobserver agreement in prostate volume definition for small to medium prostates. In large glands, H mode does not exhibit any additional advantage. Although harmonic imaging has not proven advantageous for all cases, its utilization seems to be judicious for small prostates.
Campbell, W.H. (Geological Survey, Denver, CO (USA))
1990-12-01T23:59:59.000Z
Various methods for the spherical harmonic analysis of the quiet daily variation of geomagnetic fields (Sq) measured at the Earth's surface have been used to represent the separation of the external (source) and internal (induced) currents. The results of such methods differ because the modeling techniques often reflect differing special objectives of the researcher. One method utilizes the observed field measurements at all world locations determined at a specific instant of time. A second method uses only observations in one primary hemisphere, appropriately mirroring field values for the analysis in the opposite hemisphere. The third method, a variation of the second, uses field values in the opposite hemisphere that are mirrored from a primary region that is shifted in time by 6 months. A variation of these three methods utilizes only a longitude line of observatories and assumes that the 24 hours of Sq field variation represents a 360{degree} rotation of the analysis sphere. For the comparison, power spectral representation, global current patterns in different seasons, and deviations of model-computed field values from the surface observations were all evaluated. The power spectral study showed that the spherical harmonic analysis of Sq should be extended to order m = 6 and degree n = m + 17. The northern hemisphere current system seemed to be consistently stronger than the southern hemisphere system. Exclusion of the mid-latitude vortex polynomials with (n {minus} m) = 0 and 1 was shown to be a useful technique for exposing the unique polar cap current pattern S{sup p}{sub q}. The global method was generally best for modeling; however, the hemisphere mirroring methods with 6-month time shift were almost as good in their representation of the Sq fields. Different special regions of effective and poor modeling were identified for all three methods.
Quantization and instability of the damped harmonic oscillator subject to a time-dependent force
Majima, H., E-mail: majima@rs.kagu.tus.ac.jp; Suzuki, A., E-mail: asuzuki@rs.kagu.tus.ac.jp
2011-12-15T23:59:59.000Z
We consider the one-dimensional motion of a particle immersed in a potential field U(x) under the influence of a frictional (dissipative) force linear in velocity (-{gamma}x) and a time-dependent external force (K(t)). The dissipative system subject to these forces is discussed by introducing the extended Bateman's system, which is described by the Lagrangian: L=mxy-U(x+1/2 y)+U(x-1/2 y)+({gamma})/2 (xy-yx)-xK(t)+yK(t), which leads to the familiar classical equations of motion for the dissipative (open) system. The equation for a variable y is the time-reversed of the x motion. We discuss the extended Bateman dual Lagrangian and Hamiltonian by setting U(x{+-}y/2)=1/2 k(x{+-}y/2){sup 2} specifically for a dual extended damped-amplified harmonic oscillator subject to the time-dependent external force. We show the method of quantizing such dissipative systems, namely the canonical quantization of the extended Bateman's Hamiltonian H. The Heisenberg equations of motion utilizing the quantized Hamiltonian H surely lead to the equations of motion for the dissipative dynamical quantum systems, which are the quantum analog of the corresponding classical systems. To discuss the stability of the quantum dissipative system due to the influence of an external force K(t) and the dissipative force, we derived a formula for transition amplitudes of the dissipative system with the help of the perturbation analysis. The formula is specifically applied for a damped-amplified harmonic oscillator subject to the impulsive force. This formula is used to study the influence of dissipation such as the instability due to the dissipative force and/or the applied impulsive force. - Highlights: > A method of quantizing dissipative systems is presented. > In order to obtain the method, we apply Bateman's dual system approach. > A formula for a transition amplitude is derived. > We use the formula to study the instability of the dissipative systems.
Cohen, Oren (Boulder, CO); Kapteyn, Henry C. (Boulder, CO); Mumane, Margaret M. (Boulder, CO)
2010-02-16T23:59:59.000Z
Phase matching high harmonic generation (HHG) uses a single, long duration non-collinear modulating pulse intersecting the driving pulse. A femtosecond driving pulse is focused into an HHG medium (such as a noble gas) to cause high-harmonic generation (HHG), for example in the X-ray region of the spectrum, via electrons separating from and recombining with gas atoms. A non-collinear pulse intersects the driving pulse within the gas, and modulates the field seen by the electrons while separated from their atoms. The modulating pulse is low power and long duration, and its frequency and amplitude is chosen to improve HHG phase matching by increasing the areas of constructive interference between the driving pulse and the HHG, relative to the areas of destructive interference.
Tominaga, Nozomu; Blinnikov, Sergei I
2015-01-01T23:59:59.000Z
We develop a time-dependent multi-group multidimensional relativistic radiative transfer code, which is required to numerically investigate radiation from relativistic fluids involved in, e.g., gamma-ray bursts and active galactic nuclei. The code is based on the spherical harmonic discrete ordinate method (SHDOM) that evaluates a source function including anisotropic scattering in spherical harmonics and implicitly solves the static radiative transfer equation with a ray tracing in discrete ordinates. We implement treatments of time dependence, multi-frequency bins, Lorentz transformation, and elastic Thomson and inelastic Compton scattering to the publicly available SHDOM code. Our code adopts a mixed frame approach; the source function is evaluated in the comoving frame whereas the radiative transfer equation is solved in the laboratory frame. This implementation is validated with various test problems and comparisons with results of a relativistic Monte Carlo code. These validations confirm that the code ...
Larsen, E W; Lorek, E; Heyl, C M; Palecek, D; L'Huillier, A; Zigmantas, D; Mauritsson, J
2015-01-01T23:59:59.000Z
We experimentally investigate how the ellipticity of the driving laser pulses influences high-order harmonic generation from the first two sets of quantum trajectories. Using long pulses at a high repetition rate in a tight focusing configuration combined with a spectrometer that resolves the harmonic emission both spatially and spectrally, allows for a clear separation of the emission generated by the long and the short trajectories. We find that a model describing the long trajectories has to include a sub-cycle change in both ionization rate and initial electron velocity distribution as well as a change of the excursion time when the ellipticity is changed. Additionally, we find that the configuration interaction between two electrons influences the ellipticity dependence of both trajectories through the AC-Stark shift.
Tolbert, Leon M [ORNL; Ozpineci, Burak [ORNL; Filho, Faete [ORNL; Cao, Yue [ORNL
2011-01-01T23:59:59.000Z
This work approximates the selective harmonic elimination problem using artificial neural networks (ANNs) to generate the switching angles in an 11-level full-bridge cascade inverter powered by five varying dc input sources. Each of the five full bridges of the cascade inverter was connected to a separate 195-W solar panel. The angles were chosen such that the fundamental was kept constant and the low-order harmonics were minimized or eliminated. A nondeterministic method is used to solve the system for the angles and to obtain the data set for the ANN training. The method also provides a set of acceptable solutions in the space where solutions do not exist by analytical methods. The trained ANN is a suitable tool that brings a small generalization effect on the angles' precision and is able to perform in real time (50-/60-Hz time window).
1+1+2 gravitational perturbations on LRS class II space-times: GEM vector harmonic amplitudes
R. B. Burston
2007-08-19T23:59:59.000Z
This is the second in a series of papers which considers first-order gauge-invariant and covariant gravitational perturbations to locally rotationally symmetric (LRS) class II space-times. This paper shows how to decouple a complex combination of the gravito-electromagnetic (GEM) 2-vectors with the 2-tensors describing the shear of the 2/3-sheets. An arbitrary harmonic expansion is then used along with an eigen-vector/value analysis of the first-order GEM system, analogous to the first paper in this series. This results in four real decoupled equations governing four real combinations of the harmonic amplitudes of the GEM 2-vectors and the (2/3-sheet) shear 2-tensors. Finally, these are categorized into polar and axial perturbations.
Mondal, Uttam Kr
2012-01-01T23:59:59.000Z
Providing security to audio songs for maintaining its intellectual property right (IPR) is one of chanllenging fields in commercial world especially in creative industry. In this paper, an effective approach has been incorporated to fabricate authentication of audio song through application of message digest method with alternation of coefficients of harmonics in multi-stages of higher frequency domain without affecting its audible quality. Decomposing constituent frequency components of song signal using Fourier transform with generating secret code via applying message digest followed by alternating coefficients of specific harmonics in multi-stages generates a secret code and this unique code is utilized to detect the originality of the song. A comparative study has been made with similar existing techniques and experimental results are also supported with mathematical formula based on Microsoft WAVE (".wav") stereo sound file.
Chu, Shih-I; Zhao, Di; Li, Fu-li
2013-04-11T23:59:59.000Z
We present an ab initio theoretical investigation of the coherent control and significant enhancement of multiphoton ionization (MPI) and high-order-harmonic generation (HHG) of atoms and molecules by means of intense ...
Apyan, Aram
Measurements are presented by the CMS Collaboration at the Large Hadron Collider (LHC) of the higher-order harmonic coefficients that describe the azimuthal anisotropy of charged particles emitted in ?s[subscript NN] = ...
Jin, Cheng
We investigate the efficient generation of low-divergence high-order harmonics driven by waveform-optimized laser pulses in a gas-filled hollow waveguide. The drive waveform is obtained by synthesizing two-color laser ...
Chu, Shih-I; Telnov, Dmitry A.
2007-10-11T23:59:59.000Z
We present an ab initio three-dimensional (3D) calculation of multiphoton ionization (MPI) and high-order harmonic generation (HHG) of the hydrogen molecular ions subject to intense linearly polarized laser pulses. The orientation of the molecular...
Gallegos-Lopez, Gabriel
2012-10-02T23:59:59.000Z
Methods, system and apparatus are provided for increasing voltage utilization in a five-phase vector controlled machine drive system that employs third harmonic current injection to increase torque and power output by a five-phase machine. To do so, a fundamental current angle of a fundamental current vector is optimized for each particular torque-speed of operating point of the five-phase machine.
Calculated second-harmonic susceptibilities of BN, AlN, and GaN Jian Chen,a)
Wilkins, John
and the second-harmonic susceptibility d for BN, AlN, and GaN in both zincblende and wurtzite structures within the KohnSham local-density approximation. For wurtzite AlN and GaN, the computed dxxz (w) and dzzz (w) closely agree with experiment. For zincblende AlN and GaN as well as zincblende and wurtzite BN, we
Many interacting fermions in a one-dimensional harmonic trap: a quantum-chemical treatment
Grining, Tomasz; Lesiuk, Micha?; Przybytek, Micha?; Musia?, Monika; Massignan, Pietro; Lewenstein, Maciej; Moszynski, Robert
2015-01-01T23:59:59.000Z
We employ ab initio methods of quantum chemistry to investigate spin-1/2 fermions interacting via a two-body contact potential in a one-dimensional harmonic trap. The convergence of the total energy with the size of the one-particle basis set is analytically investigated for the two-body problem and the same form of the convergence formula is numerically confirmed to be valid for the many-body case. Benchmark calculations for two to six fermions with the full configuration interaction method, equivalent to the exact diagonalization approach, and the coupled cluster method including single, double, triple, and quadruple excitations are presented. The convergence of the correlation energy with the level of excitations included in the coupled cluster model is analyzed. The range of the interaction strength for which single-reference coupled cluster methods work is examined. Next, the coupled cluster method restricted to single, double, and noniterative triple excitations, CCSD(T), is employed to study a two-comp...
Iman Marvian; Robert W. Spekkens
2014-12-05T23:59:59.000Z
Finding the consequences of symmetry for open system quantum dynamics is a problem with broad applications, including describing thermal relaxation, deriving quantum limits on the performance of amplifiers, and exploring quantum metrology in the presence of noise. The symmetry of the dynamics may reflect a symmetry of the fundamental laws of nature, a symmetry of a low-energy effective theory, or it may describe a practical restriction such as the lack of a reference frame. In this paper, we apply some tools of harmonic analysis together with ideas from quantum information theory to this problem. The central idea is to study the decomposition of quantum operations---in particular, states, measurements and channels---into different modes, which we call modes of asymmetry. Under symmetric processing, a given mode of the input is mapped to the corresponding mode of the output, implying that one can only generate a given output if the input contains all of the necessary modes. By defining monotones that quantify the asymmetry in a particular mode, we also derive quantitative constraints on the resources of asymmetry that are required to simulate a given asymmetric operation. We present applications of our results for deriving bounds on the probability of success in nondeterministic state transitions, such as quantum amplification, and a simplified formalism for studying the degradation of quantum reference frames.
A simplified spherical harmonic method for coupled electron-photon transport calculations
Josef, J.A.
1997-12-01T23:59:59.000Z
In this thesis the author has developed a simplified spherical harmonic method (SP{sub N} method) and associated efficient solution techniques for 2-D multigroup electron-photon transport calculations. The SP{sub N} method has never before been applied to charged-particle transport. He has performed a first time Fourier analysis of the source iteration scheme and the P{sub 1} diffusion synthetic acceleration (DSA) scheme applied to the 2-D SP{sub N} equations. The theoretical analyses indicate that the source iteration and P{sub 1} DSA schemes are as effective for the 2-D SP{sub N} equations as for the 1-D S{sub N} equations. In addition, he has applied an angular multigrid acceleration scheme, and computationally demonstrated that it performs as well as for the 2-D SP{sub N} equations as for the 1-D S{sub N} equations. It has previously been shown for 1-D S{sub N} calculations that this scheme is much more effective than the DSA scheme when scattering is highly forward-peaked. The author has investigated the applicability of the SP{sub N} approximation to two different physical classes of problems: satellite electronics shielding from geomagnetically trapped electrons, and electron beam problems.
Preliminary tests of a second harmonic rf system for the intense pulsed neutron source synchrotron
Norem, J.; Brandeberry, F.
1983-01-01T23:59:59.000Z
The Rapid Cycling Synchrotron (RCS) of the Intense Pulsed Neutron Source (IPNS) operating at Argonne National Laboratory is presently producing intensities of 2 to 2.5 x 10/sup 12/ protons per pulse (ppp) with the addition of a new ion source. This intensity is close to the space charge limit of the machine, estimated at approx. 3 x 10/sup 12/ ppp, depending somewhat on the available aperture. Accelerator improvements are being directed at (1) increasing beam intensities for neutron science, (2) lowering acceleration losses to minimize activation, and (3) gaining better control of the beam so that losses can be made to occur when and where they can be most easily controlled. We are now proposing a third cavity for the RF system which would provide control of the longitudinal bunch shape during the cycle which would permit raising the effective space charge limit of the accelerator and reducing losses by providing more RF voltage at maximum acceleration. This paper presents an outline of the expected benefits together with recent results obtained during low energy operation with one of the two existing cavities operating at the second harmonic (2f/sub 0/).
Data Acquisition in a High Harmonic Generation Lab and at LCLS
Hirokawa, Takako; /U. Colorado, Boulder /SLAC; ,
2011-06-22T23:59:59.000Z
In this paper, we examine data acquisition in a high harmonic generation (HHG) lab and preliminary data analysis with the Cyclohexadiene Collaboration at the Linac Coherent Lightsource (LCLS) at SLAC National Accelerator Laboratory. HHG experiments have a large number of parameters that need to be monitored constantly. In particular, the pressure of the target is critical to HHG yield. However, this pressure can fluctuate wildly and without a tool to monitor it, it is difficult to analyze the correlation between HHG yield and the pressure. I used the Arduino microcontroller board and created a complementary MATLAB graphical user interface (GUI), thereby enhancing the ease with which users can acquire time-stamped parameter data. Using the Arduino, it is much easier to match the pressure to the corresponding HHG yield. Collecting data by using the Arduino and the GUI is flexible, user-friendly, and cost-effective. In the future, we hope to be able to control and monitor parts of the lab with the Arduino alone. While more parameter information is needed in the HHG lab, we needed to reduce the amount of data during the cyclohexadiene collaboration. This was achieved by sorting the data into bins and filtering out unnecessary details. This method was highly effective in that it minimized the amount of data without losing any valuable information. This effective preliminary data analysis technique will continue to be used to decrease the size of the collected data.
Second Harmonic Generation Studies of Fe(II) Interactions with Hematite (?-Fe2O3)
Jordan, David S.; Hull, Christopher J.; Troiano, Julianne M.; Riha, Shannon C.; Martinson, Alex B.; Rosso, Kevin M.; Geiger, Franz M.
2013-02-28T23:59:59.000Z
Iron oxides are a ubiquitous class of compounds that are involved in many biological, geological, and technological processes, and the Fe(III)/Fe(II) redox couple is a fundamental transformation pathway; however, the study of iron oxide surfaces in aqueous solution by powerful spectroscopic techniques has been limited due to "strong absorber problem". In this work, atomic layer deposition (ALD) thin films of polycrystalline alpha-Fe2O3 were analyzed using the Eisenthal chi((3)) technique, a variant of second harmonic generation that reports on interfacial potentials. By determining the surface charge densities at multiple pH values, the point of zero charge was found to be 5.5 +/- 0.3. The interaction of aqueous Fe(II) at pH 4 and in 1 mM NaCl with ALD-prepared hematite was found to be fully reversible and to lead to about 4 times more ferrous iron ions adsorbed per square centimeter than on fused-silica surfaces under the same conditions. The data are consistent with a recently proposed conceptual model for net Fe(II) uptake or release that is underlain by a dynamic equilibrium between Fe(II) adsorbed onto hematite, electron transfer into favorable surface sites with attendant Fe(III) deposition, and electron conduction to favorable remote sites that release and replenish aqueous Fe(II).
N = 2 Supersymmetric Harmonic Oscillator: Basic Brackets Without Canonical Conjugate Momenta
N. Srinivas; A. Shukla; R. P. Malik
2015-08-16T23:59:59.000Z
We exploit the ideas of spin-statistics theorem, normal-ordering and the key concepts behind the symmetry principles to derive the canonical (anti)commutators for the case of a one (0 + 1)-dimensional (1D) N = 2 supersymmetric (SUSY) harmonic oscillator (HO) without taking the help of the mathematical definition of canonical conjugate momenta with respect to the bosonic and fermionic variables of this toy model for the Hodge theory (where the continuous and discrete symmetries of the theory provide the physical realizations of the de Rham cohomological operators of differential geometry). In our present endeavor, it is the full set of continuous symmetries and their corresponding generators that lead to the derivation of basic (anti)commutators amongst the creation and annihilation operators that appear in the normal mode expansions of the dynamical fermionic and bosonic variables of our present N = 2 SUSY theory of a HO. These basic brackets are in complete agreement with such kind of brackets that are derived from the standard canonical method of quantization scheme.
Barbara Betz; Miklos Gyulassy; Giorgio Torrieri
2011-08-23T23:59:59.000Z
Second Fourier harmonics of jet quenching have been thoroughly explored in the literature and shown to be sensitive to the underlying jet path-length dependence of energy loss and the differences between the mean eccentricity predicted by Glauber and CGC/KLN models of initial conditions. We compute the jet path-length dependence of energy-loss for higher azimuthal harmonics of jet-fragments in a generalized model of energy-loss for RHIC energies and find, however, that even the high-$p_T$ second moment is most sensitive to the poorly known early-time evolution during the first fm/c. Moreover, we demonstrate that higher-jet harmonics are remarkably insensitive to the initial conditions, while the different $v_n(N_{part})$ vs. $v_n^{I_{AA}}(N_{part})$ correlations between the moments of monojet and dijet nuclear modifications factors remain a most sensitive probe to differentiate between Glauber and CGC/KLN initial state sQGP geometries.
Davis, R.; Fishman, D.; Frank, E. D.; Wigmosta, M. S.; Aden, A.; Coleman, A. M.; Pienkos, P. T.; Skaggs, R. J.; Venteris, E. R.; Wang, M. Q.
2012-06-01T23:59:59.000Z
The U.S. Department of Energy's Biomass Program has begun an initiative to obtain consistent quantitative metrics for algal biofuel production to establish an 'integrated baseline' by harmonizing and combining the Program's national resource assessment (RA), techno-economic analysis (TEA), and life-cycle analysis (LCA) models. The baseline attempts to represent a plausible near-term production scenario with freshwater microalgae growth, extraction of lipids, and conversion via hydroprocessing to produce a renewable diesel (RD) blendstock. Differences in the prior TEA and LCA models were reconciled (harmonized) and the RA model was used to prioritize and select the most favorable consortium of sites that supports production of 5 billion gallons per year of RD. Aligning the TEA and LCA models produced slightly higher costs and emissions compared to the pre-harmonized results. However, after then applying the productivities predicted by the RA model (13 g/m2/d on annual average vs. 25 g/m2/d in the original models), the integrated baseline resulted in markedly higher costs and emissions. The relationship between performance (cost and emissions) and either productivity or lipid fraction was found to be non-linear, and important implications on the TEA and LCA results were observed after introducing seasonal variability from the RA model. Increasing productivity and lipid fraction alone was insufficient to achieve cost and emission targets; however, combined with lower energy, less expensive alternative technology scenarios, emissions and costs were substantially reduced.
Octahedral distortion induced magnetic anomalies in LaMn{sub 0.5}Co{sub 0.5}O{sub 3} single crystals
Manna, Kaustuv, E-mail: kaustuvmanna@gmail.com; Elizabeth, Suja; Anil Kumar, P. S. [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Bhadram, Venkata Srinu; Narayana, Chandrabhas [Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India)
2014-07-28T23:59:59.000Z
Single crystals of LaMn{sub 0.5}Co{sub 0.5}O{sub 3} belonging to the ferromagnetic-insulator and distorted perovskite class were grown using a four-mirror optical float zone furnace. The as-grown crystal crystallizes into an orthorhombic Pbnm structure. The spatially resolved 2D Raman scan reveals a strain-induced distribution of transition metal (TM)–oxygen (O) octahedral deformation in the as-grown crystal. A rigorous annealing process releases the strain, thereby generating homogeneous octahedral distortion. The octahedra tilt by reducing the bond angle TM-O-TM, resulting in a decline of the exchange energy in the annealed crystal. The critical behavior is investigated from the bulk magnetization. It is found that the ground state magnetic behavior assigned to the strain-free LaMn{sub 0.5}Co{sub 0.5}O{sub 3} crystal is of the 3D Heisenberg kind. Strain induces mean field-like interaction in some sites, and consequently, the critical exponents deviate from the 3D Heisenberg class in the as-grown crystal. The temperature-dependent Raman scattering study reveals strong spin-phonon coupling and the existence of two magnetic ground states in the same crystal.
Not Available
2010-12-07T23:59:59.000Z
The photocathode of the proposed LCLS RF Photoinjector will be irradiated by uv laser light which is generated as the third harmonic of incident fundamental ir laser light. We have investigated quantitatively the effect of input ir spectral bandwidth on the exiting longitudinal intensity profiles, energy conversion efficiencies and spectral bandwidths that characterize the third harmonic generation (THG) process with a pair of crystals. These profiles, efficiencies and bandwidths include the residual fundamental and residual second harmonic light exiting the second crystal. The intrinsic acceptance bandwidth for THG is determined by crystal material and thickness as well as the type of phase matching that is used. For our case of BBO material with type I phase matching these bandwidths are approximately 0.9 nm*cm and 0.1 nm*cm for second and third harmonic generation respectively. Consequently for fixed crystal thicknesses and a fixed input ir longitudinal profile, the specified input ir bandwidth will determine the profiles, efficiencies and bandwidths exiting the second crystal. The results reported here are predictions of the SNLO code that is available as 'freeware' from the Sandia National Laboratories. It has been modified for this work. It is critical to note that this modification has enabled us to generate SNLO predictions of the 'coupled' case in which the output of the first crystal is used as input to the second crystal. Our focus is the dependence of uv longitudinal intensity profile and THG efficiency on the input ir bandwidth and crystal thicknesses. We include here cases that best illustrate input bandwidth effects. The criteria for selection of reported cases are highest efficiency generation of quasi-rectangular uv profiles with proportional intensity ripple less than 5% rms on the plateau of the pulse. Maximizing THG efficiency typically amounts to maximizing the crystal thicknesses with the longitudinal profile constraint. The specified incident ir longitudinal profile is quasi-rectangular (i.e. nonzero risetime and falltime with small intensity variation on the plateau) with a 10 psec pulse duration (FWHM). By assumption, this profile has been established upstream of the crystals at the fundamental ir wavelength. The simplest possible optical configuration is used in this work as shown in figure 1. The first crystal is the site of second harmonic generation (SHG) driven by the incident ir irradiation of central wavelength, 800nm. Downstream of the first crystal, the second crystal is the site of third harmonic generation (THG) which occurs by sum frequency mixing. Inter-crystal optics (such as a half waveplate) are assumed to be lossless at the fundamental and second harmonic wavelengths. As shown in figure 1, a portion of the incident ir irradiation is not sequestered from the first crystal for subsequent THG in the second crystal. Also, quasi-phase matching configurations and other complex compensation schemes have not been investigated at this point. The simplistic geometry better elucidates the intrinsic acceptance bandwidth limitations imposed by the crystals. Our goal in this endeavor has been to conduct a quantitative assessment of incident ir bandwidth effects on the THG process for BBO material of varied thicknesses and not, at this stage, to comply with all uv pulse specifications for the LCLS RF Photoinjector. Nonetheless, our results can be compared with LCLS photoinjector uv pulse requirements which call for a nominal 10 psec FWHM with 1 psec risetime and falltime and a nominally flat plateau (allowing for slope adjustments) with no more than a 5% rms proportional intensity variation. Furthermore, the results of this work can be used to suggest crystal thicknesses that would likely comply with all uv pulse requirements given the appropriate longitudinal profile and bandwidth for an input ir pulse.
Kim, Yusung, E-mail: yusung-kim@uiowa.edu [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States); Muruganandham, Manickam; Modrick, Joseph M.; Bayouth, John E. [Department of Radiation Oncology, University of Iowa, Iowa City, IA (United States)
2011-07-01T23:59:59.000Z
Purpose: The aim of this study was to characterize the levels of artifacts and distortions of titanium applicators on 3.0-Tesla magnetic resonance imaging (MRI). Methods and Materials: Fletcher-Suit-Delclos-style tandem and ovoids (T and O) and tandem and ring applicator (T and R) were examined. The quality assurance (QA) phantoms for each applicator were designed and filled with copper sulphate solution (1.5 g/l). The artifacts were quantified with the registration of corresponding computed tomography (CT) images. A favorable MR sequence was searched in terms of artifacts. Using the sequence, the artifacts were determined. The geometric distortions induced by the applicators were quantified through each registration of CT and MRI without applicators. The artifacts of T and O were also evaluated on in vivo MRI datasets of 5 patients. Results: T1-weighted MRI with 1-mm slice thickness was found as a favorable MR sequence. Applying the sequence, the artifacts at the tandem tip of T and O and T and R were determined as 1.5 {+-} 0.5 mm in a superior direction in phantom studies. In the ovoids of T and O, we found artifacts less than 1.5 {+-} 0.5 mm. The artifacts of a T and O tandem in vivo were found as less than 2.6 {+-} 1.3 mm on T1-weighted MRI, whereas less than 6.9 {+-} 3.4 mm on T2-weighted MRI. No more than 1.2 {+-} 0.6 mm (3.0 {+-} 1.5 mm) of distortions, due to a titanium applicator, were measured on T1-weighted MRI (T2-). Conclusion: In 3.0-Tesla MRI, we found the artifact widths at the tip of tandem were less than 1.5 {+-} 0.5 mm for both T and O and T and R when using T1-weighted MRI in phantom studies. However, exclusive 3.0-Tesla MRI-guided brachytherapy planning with a titanium applicator should be cautiously implemented.
Preynas, M.; Laqua, H. P.; Otte, M.; Stange, T.; Aßmus, D. [Max Planck Institut für Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Wauters, T. [Association Euratom-Belgian State, LPP-ERM/KMS, 1000 Brussels (Belgium)
2014-02-12T23:59:59.000Z
Although both 1st harmonic ordinary mode (O1) and 2nd harmonic extra-ordinary mode (X2) have been successfully used to initiate pre-ionization and breakdown in many devices, a complete theoretical model is still missing to explain the success of this method. Moreover, some experimental observations are not completely understood, such as what occurs during the delay time between the turn-on of ECRH power and first signals of density or light measurements. Since during this free period the ECRH power has to be absorbed by in-vessel components, it is of prime importance to know what governs this delay time. Recently, dedicated start-up experiments have been performed on WEGA, using a 28 GHz ECRH system in X2-mode. This machine has the interesting capability to be run also as a tokamak allowing comparative experiments between stellarator (?/2? > 0) and tokamak (?/2? = 0) configurations. Different scans in heating power, neutral gas pressure, and rotational transform (?) show clearly that the start-up is a two step process. A first step following the turn-on of the ECRH power during which no measurable electron density (or just above the noise level in some cases), ECE and radiated power is detected. Its duration depends strongly on the level of injected power. The second step corresponds to the gas ionization and plasma expansion phase, with a velocity of density build-up and filling-up of the vessel volume depending mainly on pressure, gas and rotational transform. Moreover, an interesting scenario of ECRH pre-ionization without loop voltage in tokamak configuration by applying a small optimal vertical field is relevant for start-up assistance on future experiments like ITER. The results from this experimental parametric study are useful for the modeling of the start-up assisted by the second harmonic electron cyclotron resonance heating. The aim of this work is to establish predictive scenarios for both ITER and W7-X operation.
High-Harmonic Fast-Wave Power Flow Along Magnetic Field Lines in the Scrape-Off Layer of NSTX
Perkins, R. J. [Princeton Plasma Physics Laboratory (PPPL); Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Kramer, G. [Princeton Plasma Physics Laboratory (PPPL); Ahn, Joonwook [ORNL; Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Diallo, A. [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. [Princeton Plasma Physics Laboratory (PPPL); Gray, T. K. [Oak Ridge National Laboratory (ORNL); Green, David L [ORNL; Jaeger, Erwin Frederick [ORNL; Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); McLean, Adam G [ORNL; Maingi, Rajesh [ORNL; Phillips, C. K. [Princeton Plasma Physics Laboratory (PPPL); Roquemore, L. [Princeton Plasma Physics Laboratory (PPPL); Ryan, Philip Michael [ORNL; Sabbagh, S. A. [Columbia University; Taylor, G. [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)
2012-01-01T23:59:59.000Z
A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast-wave heating and current drive.
Broader source: Energy.gov [DOE]
As clean energy increasingly becomes part of the national dialogue, lenders, utilities, and lawmakers need the most comprehensive and accurate information on GHG emissions from various sources of energy to inform policy, planning, and investment decisions. The National Renewable Energy Laboratory (NREL) recently led the Life Cycle Assessment (LCA) Harmonization Project, a study that gives decision makers and investors more precise estimates of life cycle GHG emissions for renewable and conventional generation, clarifying inconsistent and conflicting estimates in the published literature, and reducing uncertainty.
Mark, J. Abraham Hudson, E-mail: a.john.peter@gmail.com; Peter, A. John, E-mail: a.john.peter@gmail.com [Dept. of Physics, SSM Institute of Engineering and Technology, Dindigul-624002 (India)
2014-04-24T23:59:59.000Z
Third order susceptibility of third order harmonic generation is investigated in a Zn{sub 0.1}Mg{sub 0.9}Se/Zn{sub 0.8}Mg{sub 0.2}Se/Zn{sub 0.1}Mg{sub 0.9}Se quantum well in the presence of magnetic field strength. The confinement potential is considered as the addition of energy offsets of the conduction band (or valence band) and the strain-induced potential in our calculations. The material dependent effective mass is followed throughout the computation because it has a high influence on the electron energy levels in low dimensional semiconductor systems.
A simplified spherical harmonic method for coupled electron-photon transport calculations
Josef, J.A.
1996-12-01T23:59:59.000Z
In this thesis we have developed a simplified spherical harmonic method (SP{sub N} method) and associated efficient solution techniques for 2-D multigroup electron-photon transport calculations. The SP{sub N} method has never before been applied to charged-particle transport. We have performed a first time Fourier analysis of the source iteration scheme and the P{sub 1} diffusion synthetic acceleration (DSA) scheme applied to the 2-D SP{sub N} equations. Our theoretical analyses indicate that the source iteration and P{sub 1} DSA schemes are as effective for the 2-D SP{sub N} equations as for the 1-D S{sub N} equations. Previous analyses have indicated that the P{sub 1} DSA scheme is unstable (with sufficiently forward-peaked scattering and sufficiently small absorption) for the 2-D S{sub N} equations, yet is very effective for the 1-D S{sub N} equations. In addition, we have applied an angular multigrid acceleration scheme, and computationally demonstrated that it performs as well for the 2-D SP{sub N} equations as for the 1-D S{sub N} equations. It has previously been shown for 1-D S{sub N} calculations that this scheme is much more effective than the DSA scheme when scattering is highly forward-peaked. We have investigated the applicability of the SP{sub N} approximation to two different physical classes of problems: satellite electronics shielding from geomagnetically trapped electrons, and electron beam problems. In the space shielding study, the SP{sub N} method produced solutions that are accurate within 10% of the benchmark Monte Carlo solutions, and often orders of magnitude faster than Monte Carlo. We have successfully modeled quasi-void problems and have obtained excellent agreement with Monte Carlo. We have observed that the SP{sub N} method appears to be too diffusive an approximation for beam problems. This result, however, is in agreement with theoretical expectations.
Shao Tianjiao [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao Guangjiu; Yang Huan [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); School of Physics, Shandong University, Jinan 250100 (China); Wen Bin [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)
2010-12-15T23:59:59.000Z
In the present work, laser-parameter effects on the isolated attosecond pulse generation from two-color high-order harmonic generation (HHG) process are theoretically investigated by use of a wave-packet dynamics method. A 6-fs, 800-nm, 6x10{sup 14}W/cm{sup 2}, linearly polarized laser pulse serves as the fundamental driving pulse and parallel linearly polarized control pulses at 400 nm (second harmonic) and 1600 nm (half harmonic) are superimposed to create a two-color field. Of the two techniques, we demonstrate that using a half-harmonic control pulse with a large relative strength and zero phase shift relative to the fundamental pulse is a more promising way to generate the shortest attosecond pulses. As a consequence, an isolated 12-as pulse is obtained by Fourier transforming an ultrabroad xuv continuum of 300 eV in the HHG spectrum under half-harmonic control scheme when the relative strength {radical}(R)=0.6 and relative phase =0.
Ruberti, M.; Averbukh, V. [Department of Physics, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Decleva, P. [Dipartimento di Scienze Chimiche, Universita’ di Trieste, Via Giorgieri 1, I-34127 Trieste (Italy)
2014-10-28T23:59:59.000Z
We present the first implementation of the ab initio many-body Green's function method, algebraic diagrammatic construction (ADC), in the B-spline single-electron basis. B-spline versions of the first order [ADC(1)] and second order [ADC(2)] schemes for the polarization propagator are developed and applied to the ab initio calculation of static (photoionization cross-sections) and dynamic (high-order harmonic generation spectra) quantities. We show that the cross-section features that pose a challenge for the Gaussian basis calculations, such as Cooper minima and high-energy tails, are found to be reproduced by the B-spline ADC in a very good agreement with the experiment. We also present the first dynamic B-spline ADC results, showing that the effect of the Cooper minimum on the high-order harmonic generation spectrum of Ar is correctly predicted by the time-dependent ADC calculation in the B-spline basis. The present development paves the way for the application of the B-spline ADC to both energy- and time-resolved theoretical studies of many-electron phenomena in atoms, molecules, and clusters.
Mohamed, T. [Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Physics department, Faculty of Science, Beni-Suef University (Egypt); Mohri, A. [Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamazaki, Y. [Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Institute of Physics, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)
2013-01-15T23:59:59.000Z
Confinement of high density electron plasmas in a strong uniform magnetic field was experimentally studied in a multi-ring trap (MRT). The trap was housed inside a bore tube and surrounded by a superconducting solenoid. A 5 T magnetic field was used to provide radial confinement while an electrostatic harmonic or rectangular potential well was used for axial confinement. For trapped electrons of N = 1.2 Multiplication-Sign 10{sup 10} in a harmonic potential well (HPW) with the trap length of L{sub T} = 320 mm, the plasma lifetime was about 10{sup 4} s and it became much longer at lower N = 4.5 Multiplication-Sign 10{sup 9}. Such long holding times were achieved without application of rotating electric fields. Contrastingly, in a rectangular potential well (RPW), the plasma of N = 1.2 Multiplication-Sign 10{sup 10} under the same trap length expanded to cover the whole Faraday Cup within 200 s, where its radial expansion rate was {eta} = 3.2 Multiplication-Sign 10{sup -2} mm/s, which was 20 times faster than HPW. The lifetime for RPW became shorter with increasing L{sub T} and scaled as 1/[L{sub T}]{sup 2}. This scaling found for high density plasmas is similar to the obtained one with different Penning-Malmberg traps at UC San Diego (USCD).
R. B. Burston
2007-08-14T23:59:59.000Z
This paper considers gauge-invariant and covariant gravitational perturbations on arbitrary vacuum locally rotationally symmetric (LRS) class II space-times. Ultimately, we derive four decoupled equations governing four specific combinations of the gravito-electromagnetic (GEM) 2-tensor harmonic amplitudes. We use the gauge-invariant and covariant 1+1+2 formalism which Clarkson and Barrett developed for analysis of vacuum Schwarzschild perturbations. In particular we focus on the first-order 1+1+2 GEM system and use linear algebra techniques suitable for exploiting its structure. Consequently, we express the GEM system new 1+1+2 complex form by choosing new complex GEM tensors, which is conducive to decoupling. We then show how to derive a gauge-invariant and covariant decoupled equation governing a newly defined complex GEM 2-tensor. Finally, the GEM 2-tensor is expanded in terms of arbitrary tensor harmonics and linear algebra is used once again to decouple the system further into 4 real decoupled equations.
Layden, B.; Cairns, Iver H.; Robinson, P. A. [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia); Percival, D. J. [Defence Science and Technology Organisation, P.O. Box 1500, Edinburgh, South Australia 5111 (Australia)
2011-02-15T23:59:59.000Z
Three-wave interactions in plasmas are described, in the framework of kinetic theory, by the quadratic response tensor (QRT). The cold-plasma QRT is a common approximation for interactions between three fast waves. Here, the first-order thermal correction (FOTC) to the cold-plasma QRT is derived for interactions between three fast waves in a warm unmagnetized collisionless plasma, whose particles have an arbitrary isotropic distribution function. The FOTC to the cold-plasma QRT is shown to depend on the second moment of the distribution function, the phase speeds of the waves, and the interaction geometry. Previous calculations of the rate for second harmonic plasma emission (via Langmuir-wave coalescence) assume the cold-plasma QRT. The FOTC to the cold-plasma QRT is used here to calculate the FOTC to the second harmonic emission rate, and its importance is assessed in various physical situations. The FOTC significantly increases the rate when the ratio of the Langmuir phase speed to the electron thermal speed is less than about 3.
White, Craig Douglas
2014-01-13T23:59:59.000Z
on Situational Judgment Test Response Formats (Glaze, Jarrett, Arthur, Schurig, & Taylor, 2011)……….................................5 Mean Data………………………….……………...……………………6 Construct-related Validity……………………………..……..…………6 Subgroup Differences... …………….…………………………....….....…8 Response Distortion………………………………………………..….10 Present Study……….………………………………………………...………….11 Construct-related Validity: Alternative Explanation of Glaze et al.’s (2011) Results………………………………………...………12 Hypothesis 1...
Biswanath Rath
2015-02-27T23:59:59.000Z
We notice that PT symmetric non-Hermitian one dimensional simple Harmonic Oscillator under simultaneous transformation of co-ordinate and momentum with proper selection of wave function can also reflect real negative energy eigen spectra provided the associated wave function is well behaved, square integrable and normalised to unity. PACS: 03.65Db, 11.30.Pb, 11.30.Er, 03.65-w Key words: P T symmetry, Non-Hermitian Harmonic oscillator, Negative energy, wave function, simultaneous transformation, co-ordinate, momentum. Perturbation theory.
Boylan, Matthew
p-adic limit formula for the modular parametrization of Gauss' quadratic AGM. #12;Submitted of harmonic weak Maass forms to the study of modular forms related to Gauss' quadratic arithmetic), ) Sk(0(N), ). Moreover, a harmonic weak Maass form f(z) H2-k(0(N), ) canonically decomposes as the sum
Thompson, Lonny L.
L.L.Thompson: Finite element methods for acoustics, Preprint: J.Acoust.Soc.Am. A review of finite element methods for time-harmonic acoustics Lonny L. Thompson Department of Mechanical Engineering, Clemson University Clemson, South Carolina, 29634-0921, USA Email: lonny.thompson@ces.clemson.edu (Dated
Eisenthal, Kenneth B.
selective second harmonic generation method, were found to be markedly different. Transmembrane movement of ions is an important cellular process that plays a vital role in transforming energy and processing information in living cells. Although the nonpolar core of biological membranes is highly impermeable to most
Tolbert, Leon M.
://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TIA.2011.2161533 fuel cells, or solar panels and will consequently bring-Time Selective Harmonic Minimization for Multilevel Inverters Connected to Solar Panels Using Artificial Neural of the five full bridges of the cascade inverter was connected to a separate 195-W solar panel. The angles
instance, the melody C# B G A can be harmo-nized in the Open G tuning with the two drones
Sethares, William A.
16 instance, the melody C# B G A can be harmo- nized in the Open G tuning with the two drones B in any key. One of the most common uses of open tunings is to play the open strings as drones the harmonic motion is in the treble, the lower strings tend to be used as drones. For instance, in the Open G
Kon, Mark
Review of Wavelet Theory and Harmonic Analysis in Applied Sciences, C.E. D'Atellis and E.M. Fernandez-Berdaguer, Ed. Mark A. Kon, Boston University Wavelet theory has had a far-reaching influence, not only on the theory of wavelets, but on their applications in almost every area of science which has
Liu, X.-J.; Fukuzawa, H.; Pruemper, G.; Ueda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); RIKEN, XFEL Project Head Office, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Okunishi, M.; Shimada, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Motomura, K.; Saito, N. [RIKEN, XFEL Project Head Office, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); National Metrology Institute of Japan, AIST, Tsukuba 305-8568 (Japan); Iwayama, H.; Nagaya, K.; Yao, M. [RIKEN, XFEL Project Head Office, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Rudenko, A. [RIKEN, XFEL Project Head Office, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Max Planck Advanced Study Group, CFEL, D-22607, Hamburg (Germany); Ullrich, J. [RIKEN, XFEL Project Head Office, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Max Planck Advanced Study Group, CFEL, D-22607, Hamburg (Germany); Max Planck-Insitut fuer Kernphysik, D-69117 Heidelberg (Germany); Foucar, L. [RIKEN, XFEL Project Head Office, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Institut fuer Kernphysik, Universitaet Frankfurt, D-60486 Frankfurt (Germany); Czasch, A.; Schmidt-Boecking, H.; Doerner, R. [Institut fuer Kernphysik, Universitaet Frankfurt, D-60486 Frankfurt (Germany); Nagasono, M.; Higashiya, A.; Yabashi, M. [RIKEN, XFEL Project Head Office, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); and others
2009-05-15T23:59:59.000Z
We have developed a cold-target recoil-ion momentum spectroscopy apparatus dedicated to the experiments using the extreme-ultraviolet light pulses at the free-electron laser facility, SPring-8 Compact SASE Source test accelerator, in Japan and used it to measure spatial distributions of fundamental, second, and third harmonics at the end station.
Theil, Florian
November 21, 2006 15:33 WSPC - Proceedings Trim Size: 9in x 6in SIMAIproc 1 Energy transport that describe the macroscopic energy transport we introduce the Wigner transform and change variables so of energy transport in harmonic lattices with acoustic dispersion relation. Keywords: Semiclassical analysis
Third Harmonic Flow of Charged Particles in Au+Au Collisions at sqrtsNN = 200 GeV
STAR Collaboration; L. Adamczyk; J. K. Adkins; G. Agakishiev; M. M. Aggarwal; Z. Ahammed; I. Alekseev; J. Alford; C. D. Anson; A. Aparin; D. Arkhipkin; E. Aschenauer; G. S. Averichev; J. Balewski; A. Banerjee; Z. Barnovska; D. R. Beavis; R. Bellwied; M. J. Betancourt; R. R. Betts; A. Bhasin; A. K. Bhati; H. Bichsel; J. Bielcik; J. Bielcikova; L. C. Bland; I. G. Bordyuzhin; W. Borowski; J. Bouchet; A. V. Brandin; S. G. Brovko; E. Bruna; S. Bültmann; I. Bunzarov; T. P. Burton; J. Butterworth; H. Caines; M. Calderón de la Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; P. Chaloupka; Z. Chang; S. Chattopadhyay; H. F. Chen; J. H. Chen; J. Y. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; W. Christie; P. Chung; J. Chwastowski; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; X. Cui; S. Das; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; J. Deng; R. Derradi de Souza; S. Dhamija; B. di Ruzza; L. Didenko; F. Ding; A. Dion; P. Djawotho; X. Dong; J. L. Drachenberg; J. E. Draper; C. M. Du; L. E. Dunkelberger; J. C. Dunlop; L. G. Efimov; M. Elnimr; J. Engelage; K. S. Engle; G. Eppley; L. Eun; O. Evdokimov; R. Fatemi; S. Fazio; J. Fedorisin; R. G. Fersch; P. Filip; E. Finch; Y. Fisyak; C. E. Flores; C. A. Gagliardi; D. R. Gangadharan; D. Garand; F. Geurts; A. Gibson; S. Gliske; O. G. Grebenyuk; D. Grosnick; Y. Guo; A. Gupta; S. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L. -X. Han; R. Haque; J. W. Harris; J. P. Hays-Wehle; S. Heppelmann; A. Hirsch; G. W. Hoffmann; D. J. Hofman; S. Horvat; B. Huang; H. Z. Huang; P. Huck; T. J. Humanic; G. Igo; W. W. Jacobs; C. Jena; E. G. Judd; S. Kabana; K. Kang; K. Kauder; H. W. Ke; D. Keane; A. Kechechyan; A. Kesich; D. P. Kikola; J. Kiryluk; I. Kisel; A. Kisiel; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; W. Korsch; L. Kotchenda; P. Kravtsov; K. Krueger; I. Kulakov; L. Kumar; M. A. C. Lamont; J. M. Landgraf; K. D. Landry; S. LaPointe; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; L. M. Lima; M. A. Lisa; F. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; X. Luo; A. Luszczak; G. L. Ma; Y. G. Ma; D. M. M. D. Madagodagettige Don; D. P. Mahapatra; R. Majka; S. Margetis; C. Markert; H. Masui; H. S. Matis; D. McDonald; T. S. McShane; S. Mioduszewski; M. K. Mitrovski; Y. Mohammed; B. Mohanty; M. M. Mondal; M. G. Munhoz; M. K. Mustafa; M. Naglis; B. K. Nandi; Md. Nasim; T. K. Nayak; J. M. Nelson; L. V. Nogach; J. Novak; G. Odyniec; A. Ogawa; K. Oh; A. Ohlson; V. Okorokov; E. W. Oldag; R. A. N. Oliveira; D. Olson; M. Pachr; B. S. Page; S. K. Pal; Y. X. Pan; Y. Pandit; Y. Panebratsev; T. Pawlak; B. Pawlik; H. Pei; C. Perkins; W. Peryt; P. Pile; M. Planinic; J. Pluta; D. Plyku; N. Poljak; J. Porter; A. M. Poskanzer; C. B. Powell; C. Pruneau; N. K. Pruthi; M. Przybycien; P. R. Pujahari; J. Putschke; H. Qiu; S. Ramachandran; R. Raniwala; S. Raniwala; C. K. Riley; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; J. F. Ross; A. Roy; L. Ruan; J. Rusnak; N. R. Sahoo; P. K. Sahu; I. Sakrejda; S. Salur; A. Sandacz; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; B. Schmidke; N. Schmitz; T. R. Schuster; J. Seger; P. Seyboth; N. Shah; E. Shahaliev; M. Shao; B. Sharma; M. Sharma; W. Q. Shen; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; R. N. Singaraju; M. J. Skoby; D. Smirnov; N. Smirnov; D. Solanki; P. Sorensen; U. G. deSouza; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. C. Suarez; M. Sumbera; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; L. H. Tarini; T. Tarnowsky; J. H. Thomas; A. R. Timmins; D. Tlusty; M. Tokarev; S. Trentalange; R. E. Tribble; P. Tribedy; B. A. Trzeciak; O. D. Tsai; J. Turnau; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; R. Vertesi; F. Videbæk; Y. P. Viyogi; S. Vokal; S. A. Voloshin; A. Vossen; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; Q. Wang; X. L. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; H. Wieman; S. W. Wissink; R. Witt; Y. F. Wu; Z. Xiao; W. Xie; K. Xin; H. Xu; N. Xu; Q. H. Xu; W. Xu; Y. Xu; Z. Xu; C. Yang; Y. Yang; Y. Yang; P. Yepes; L. Yi; K. Yip; I. -K. Yoo; Y. Zawisza; H. Zbroszczyk; W. Zha; J. B. Zhang; S. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; F. Zhao; J. Zhao; C. Zhong; X. Zhu; Y. H. Zhu; Y. Zoulkarneeva; M. Zyzak
2013-07-15T23:59:59.000Z
We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v_3, known as triangular flow. The analysis is for charged particles in Au+Au collisions at sqrtsNN = 200 GeV, based on data from the STAR experiment at the Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are reported as a function of transverse momentum and centrality. A large dependence on the pseudorapidity gap is found. Results are compared with other experiments and model calculations.
Gianninas, A.; Barber, Sara D.; Kilic, Mukremin [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Hermes, J. J.; Harrold, Samuel T. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Brown, Warren R.; Kenyon, Scott J. [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States); Dufour, P., E-mail: alexg@nhn.ou.edu [Département de Physique, Université de Montréal, C.P. 6128, Succ. Centre-Ville, Montréal, Québec H3C 3J7 (Canada)
2014-02-01T23:59:59.000Z
We present the discovery of an unusual, tidally distorted extremely low mass white dwarf (WD) with nearly solar metallicity. Radial velocity measurements confirm that this is a compact binary with an orbital period of 2.6975 hr and a velocity semi-amplitude of K = 108.7 km s{sup –1}. Analysis of the hydrogen Balmer lines yields an effective temperature of T {sub eff} = 8380 K and a surface gravity of log g = 6.21 that in turn indicate a mass of M = 0.16 M {sub ?} and a cooling age of 4.2 Gyr. In addition, a detailed analysis of the observed metal lines yields abundances of log (Mg/H) = –3.90, log (Ca/H) = –5.80, log (Ti/H) = –6.10, log (Cr/H) = –5.60, and log (Fe/H) = –4.50, similar to the sun. We see no evidence of a debris disk from which these metals would be accreted, though the possibility cannot entirely be ruled out. Other potential mechanisms to explain the presence of heavy elements are discussed. Finally, we expect this system to ultimately undergo unstable mass transfer and merge to form a ?0.3-0.6 M {sub ?} WD in a few Gyr.
Li, Yun-He; Zhang, Xin
2014-01-01T23:59:59.000Z
Dark energy can modify the dynamics of dark matter if there exists a direct interaction between them. Thus a measurement of the structure growth, e.g., redshift-space distortions (RSD), can be a powerful tool to constrain the interacting dark energy (IDE) models. For the widely studied $Q=3\\beta H\\rho_{de}$ model, previous works showed that only a very small coupling ($\\beta\\sim\\mathcal{O}(10^{-3})$) can survive in current RSD data. However, all these analyses have to assume $w>-1$ and $\\beta>0$ due to the existence of the large-scale instability in the IDE scenario. In our recent work [Phys.\\ Rev.\\ D {\\bf 90}, 063005 (2014)], we successfully solved this large-scale instability problem by establishing a parametrized post-Friedmann (PPF) framework for the IDE scenario. So we, for the first time, have the ability to explore the full parameter space of the IDE models. In this work, we reexamine the observational constraints on the $Q=3\\beta H\\rho_{de}$ model within the PPF framework. By using the Planck data, th...
Haw, Shu-Chih; Chen, Shin-Ann [Department of Engineering and System Science, National Tsing Hua University, 30013 Hsinchu, Taiwan (China) [Department of Engineering and System Science, National Tsing Hua University, 30013 Hsinchu, Taiwan (China); National Synchrotron Radiation Research Center (NSRRC), 101 HsinAnn Road, 30076 Hsinchu, Taiwan (China); Lee, Jenn-Min; Lu, Kueih-Tzu; Lee, Ming-Tao; Pi, Tun-Wen; Chen, Jin-Ming, E-mail: jmchen@nsrrc.org.tw, E-mail: Zhiwei.Hu@cpfs.mpg.de [National Synchrotron Radiation Research Center (NSRRC), 101 HsinAnn Road, 30076 Hsinchu, Taiwan (China)] [National Synchrotron Radiation Research Center (NSRRC), 101 HsinAnn Road, 30076 Hsinchu, Taiwan (China); Lin, Pao-An [Department of Physics, National Tsing Hua University, 30013 Hsinchu, Taiwan (China)] [Department of Physics, National Tsing Hua University, 30013 Hsinchu, Taiwan (China); Lee, Chih-Hao [Department of Engineering and System Science, National Tsing Hua University, 30013 Hsinchu, Taiwan (China)] [Department of Engineering and System Science, National Tsing Hua University, 30013 Hsinchu, Taiwan (China); Hu, Zhiwei, E-mail: jmchen@nsrrc.org.tw, E-mail: Zhiwei.Hu@cpfs.mpg.de [Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden (Germany)] [Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden (Germany)
2014-04-21T23:59:59.000Z
The b-axis oriented orthorhombic YMnO{sub 3} (o-YMnO{sub 3}) epitaxial films on a YAlO{sub 3} (010) substrate were fabricated with pulsed-laser deposition. The anisotropic orbital occupation and Jahn-Teller (JT) distortion of an o-YMnO{sub 3} film were investigated with polarization-dependent x-ray absorption spectra and configuration-interaction multiplet-cluster calculations. A significant energy difference, ?3.8 eV, for the main white line along E//b and E//a in polarization-dependent Mn K-edge spectra of o-YMnO{sub 3} indicates an extraordinary JT distortion and significant anisotropic Mn–O bonding within the ab plane in the o-YMnO{sub 3} film. Most importantly, although the orbital occupation of 3d electrons in o-YMnO{sub 3} films is almost the same as that in single crystalline o-DyMnO{sub 3}, the JT distortion of o-YMnO{sub 3} films is larger than that of single crystalline o-DyMnO{sub 3}, deduced from the multiplet calculations. We speculate that this JT distortion predominantly contributes to the origin of the cycloidal spin deformation in bulk o-YMnO{sub 3}, because of a suppressed nearest-neighbor superexchange interaction and an enhanced next-nearest-neighbor superexchange interaction. These complementary results provide insight into the origin of the E-type magnetic configuration of o-YMnO{sub 3}.
Stefano Beltraminelli; Danilo Merlini; Sergey Sekatskii
2013-06-20T23:59:59.000Z
We propose an architecture of a conjecture concerning the Riemann Hypothesis in the form of an "alternative" to the P\\'olya strategy: we construct a Hamiltonian H_Polya whose spectrum coincides exactly with that of the Harmonic Oscillator Hamiltonian H_osc if and only if the Riemann Hypothesis holds true. In other words, it can be said that we formulate the Riemann Hypothesis by means of a non-commutative structure on the real axis, viz., that of the Harmonic Oscillator, by an equation of the type H_Polya(H_osc) = H_osc: the Harmonic Oscillator operator, if viewed as an argument of H_Polya, reproduces itself.
Cooperative Control of Active Power Filters in Power Systems without Mutual Communication
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tlustý, Josef; Škramlík, Ji?í; Švec, Jan; Valouch, Viktor
2010-01-01T23:59:59.000Z
The procedure for calculating controller parameters of the APFs implemented into a multibus industrial power system for harmonic voltage mitigation is presented. The node-voltage-detection control strategy is applied and the basic controller parameters are found under the condition that the demanded THD factors at the buses where the APFs are placed will be obtained. A cooperative control of several APFs without mutual communication is proposed, simulated, and experimentally verified. By tuning the controller gains without considering the power circuit parameters, all APFs used tend to share harmonic load currents approximately equally regardless of the operation modes of the nonlinear loadsmore »in different parts of the power system.« less
Dundas, Daniel
2012-01-01T23:59:59.000Z
A mixed quantum-classical approach is introduced which allows the dynamically response of molecules driven far from equilibrium to be modeled. This method is applied here to the interaction of molecules with intense, short-duration laser pulses. The electronic response of the molecule is described using time-dependent density functional theory (TDDFT) and the resulting Kohn-Sham equations are solved numerically using finite difference techniques in conjunction with local and global adaptations of an underlying grid in curvilinear coordinates. Using this approach, simulations can be carried out for a wide range of molecules and both all-electron and pseudopotential calculations can be performed. The approach is applied to the study of high harmonic generation in N_2 and benzene using linearly-polarized laser pulses and to the best of our knowledge, the results for benzene represent the first TDDFT calculations of high harmonic generation in benzene using linearly polarized laser pulses. For N_2 an enhancement ...
Zhang Pei [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg (Germany); Baboi, Nicoleta [Deutsches Elektronen-Synchrotron (DESY), 22607 Hamburg (Germany); Jones, Roger M.; Shinton, Ian R. R. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Cockcroft Institute, Cheshire WA4 4AD (United Kingdom); Flisgen, Thomas; Glock, Hans-Walter [Institut fuer Allgemeine Elektrotechnik, Universitaet Rostock, 18051 Rostock (Germany)
2012-08-15T23:59:59.000Z
We investigate the feasibility of beam position diagnostics using higher order mode (HOM) signals excited by an electron beam in the third harmonic 3.9 GHz superconducting accelerating cavities at FLASH. After careful theoretical and experimental assessment of the HOM spectrum, three modal choices have been narrowed down to fulfill different diagnostics requirements. These are localized dipole beam-pipe modes, trapped cavity modes from the fifth dipole band, and propagating modes from the first two dipole bands. These modes are treated with various data analysis techniques: modal identification, direct linear regression (DLR), and singular value decomposition (SVD). Promising options for beam diagnostics are found from all three modal choices. This constitutes the first prediction, subsequently confirmed by experiments, of trapped HOMs in third harmonic cavities, and also the first direct comparison of DLR and SVD in the analysis of HOM-based beam diagnostics.
Carrera, Juan J.; Chu, Shih-I; Tong, Xiao-Min
2005-06-21T23:59:59.000Z
We present an ab initio nonpertubative investigation of the mechanisms responsible for the production of very-high-order harmonic generation (HHG) from Ar atoms and Ar+ ions by means of the self-interaction-free time-dependent density...