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Efficient Mining of Partial Periodic Patterns in Time Series Database
Dong, Guozhu
Efficient Mining of Partial Periodic Patterns in Time Series Database In ICDE 99 Jiawei Han \\Lambda peri odic patterns in timeseries databases, is an interesting data mining problem. Previous studies several algorithms for efficient mining of par tial periodic patterns, by exploring some interesting
TIME-PERIODIC SOUND WAVE PROPAGATION COMPRESSIBLE EULER EQUATIONS
A PARADIGM FOR TIME-PERIODIC SOUND WAVE PROPAGATION IN THE COMPRESSIBLE EULER EQUATIONS BLAKE consistent with time-periodic sound wave propagation in the 3 Ă? 3 nonlinear compressible Euler equations description of shock-free waves that propagate through an oscillating entropy field without breaking or dis
Controlling mobility via rapidly oscillating time-periodic stimulus
Prasun Sarkar; Alok Kumar Maity; Anindita Shit; Sudip Chattopadhyay; Jyotipratim Ray Chaudhuri; Suman K Banik
2014-03-26T23:59:59.000Z
To address the dynamics of a Brownian particle on a periodic symmetric substrate under high-frequency periodic forcing with a vanishing time average, we construct an effective Langevin dynamics by invoking Kapitza-Landau time window. Our result is then exploited to simulate the mobility both for original and effective dynamics which are in good agreement with theoretical predictions. This close agreement and the enhancement of mobility are very robust against the tailoring of amplitude-to-frequency ratio which substantiates the correctness of our calculation. Present results may be illuminating for understanding the dynamics of cold atoms in electromagnetic fields.
Local Lyapunov Functions for periodic and finite-time ODEs
Hafstein, Sigurđur Freyr
Local Lyapunov Functions for periodic and finite-time ODEs Peter Giesl and Sigurdur Hafstein Abstract Lyapunov functions for general systems are difficult to construct. How- ever, for autonomous Lyapunov function by solving a matrix equa- tion. Consequently, the same function is a local Lyapunov
Time-periodic solutions of the Benjamin-Ono equation
Ambrose , D.M.; Wilkening, Jon
2008-04-01T23:59:59.000Z
We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.
Non-existence of time-periodic vacuum spacetimes
Alexakis, Spyros
2015-01-01T23:59:59.000Z
We prove that smooth asymptotically flat solutions to the Einstein vacuum equations which are assumed to be periodic in time, are in fact stationary in a neighborhood of infinity. Our result applies under physically relevant regularity assumptions purely at the level of the initial data. In particular, our work removes the assumption of analyticity up to null infinity in [Bicak, Scholtz, and Tod; 2010]. The proof relies on extending a suitably constructed "candidate" Killing vector field from null infinity, via Carleman-type estimates obtained in [Alexakis, Schlue, Shao; 2013].
Feedback Control of the Sawtooth Period through Real Time Control of the Ion Cyclotron Resonance Frequency
Periodic schedules for Unitary Timed Weighted Event Graphs
Paris-Sud XI, Université de
Event Graph model (TEG also called marked graphs [5]) and dataflow graphs, oftenly used in the computer questions are polynomially solved for ordinary TEG [1], [5], [6], [8]. In particular, it has been shown that if a TEG is live, there always exists a periodic schedule with the optimal throughput (i.e. with the same
Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction
Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction-dimensional systems subject to a periodic force and study numer- ically how a time-varying friction affects oscillator in the presence of friction. We find that, if the damping coefficient increases in time up
Efficient Solvers for Nonlinear Time-Periodic Eddy Current F. Bachinger
Schoeberl, Joachim
Efficient Solvers for Nonlinear Time-Periodic Eddy Current Problems F. Bachinger U. Langer J. Sch-periodic eddy current problems, ranging from the description of the nonlinearity to an efficient solution setup, the magnetic field and the thereby generated eddy currents hardly penetrate into conducting
Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction
Bartuccelli, Michele
Attractiveness of periodic orbits in parametrically forced systems with time- increasing friction with time-increasing friction Michele Bartuccelli,1,a) Jonathan Deane,1,b) and Guido Gentile2,c) 1 oscillator in the presence of friction, and study numerically how time-varying friction affects the dynamics
Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage
Paris-Sud XI, UniversitĂ© de
Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage-time computing system that is powered through a renewable energy storage device. In this context, two constraints for the properties of the energy source, capacity of the energy storage as well as energy consumption of the tasks
QUANTUM ENERGY EXPECTATION IN PERIODIC TIME-DEPENDENT HAMILTONIANS VIA GREEN
QUANTUM ENERGY EXPECTATION IN PERIODIC TIME-DEPENDENT HAMILTONIANS VIA GREEN FUNCTIONS CÂ´ESAR R. DE. Introduction 1 2. Average Energy and Green Functions 4 3. Applications 10 3.1. Time-Independent Hamiltonians 10(t). For each positive and discrete observable A (which we call a probe energy), we derive a formula
Global Clock, Physical Time Order and Pending Period Analysis in Multiprocessor Systems
Chen, Yunji; Hu, Weiwu
2009-01-01T23:59:59.000Z
In multiprocessor systems, various problems are treated with Lamport's logical clock and the resultant logical time orders between operations. However, one often needs to face the high complexities caused by the lack of logical time order information in practice. In this paper, we utilize the \\emph{global clock} to infuse the so-called \\emph{pending period} to each operation in a multiprocessor system, where the pending period is a time interval that contains the performed time of the operation. Further, we define the \\emph{physical time order} for any two operations with disjoint pending periods. The physical time order is obeyed by any real execution in multiprocessor systems due to that it is part of the truly happened operation orders restricted by global clock, and it is then proven to be independent and consistent with traditional logical time orders. The above novel yet fundamental concepts enables new effective approaches for analyzing multiprocessor systems, which are named \\emph{pending period analy...
Quantum Energy Expectation in Periodic Time-Dependent hamiltonians via Green Functions
Cesar R. de Oliveira; Mariza S. Simsen
2009-07-31T23:59:59.000Z
Let $U_F$ be the Floquet operator of a time periodic hamiltonian $H(t)$. For each positive and discrete observable $A$ (which we call a {\\em probe energy}), we derive a formula for the Laplace time average of its expectation value up to time $T$ in terms of its eigenvalues and Green functions at the circle of radius $e^{1/T}$. Some simple applications are provided which support its usefulness.
Skolski, J. Z. P., E-mail: j.z.p.skolski@utwente.nl; Vincenc Obona, J. [Materials innovation institute M2i, Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Römer, G. R. B. E.; Huis in 't Veld, A. J. [Faculty of Engineering Technology, Chair of Applied Laser Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)
2014-03-14T23:59:59.000Z
A model predicting the formation of laser-induced periodic surface structures (LIPSSs) is presented. That is, the finite-difference time domain method is used to study the interaction of electromagnetic fields with rough surfaces. In this approach, the rough surface is modified by “ablation after each laser pulse,” according to the absorbed energy profile, in order to account for inter-pulse feedback mechanisms. LIPSSs with a periodicity significantly smaller than the laser wavelength are found to “grow” either parallel or orthogonal to the laser polarization. The change in orientation and periodicity follow from the model. LIPSSs with a periodicity larger than the wavelength of the laser radiation and complex superimposed LIPSS patterns are also predicted by the model.
Ruoxi Xiang; Michael Small
2014-06-18T23:59:59.000Z
In this work, the topologies of networks constructed from time series from an underlying system undergo a period doubling cascade have been explored by means of the prevalence of different motifs using an efficient computational motif detection algorithm. By doing this we adopt a refinement based on the $k$ nearest neighbor recurrence-based network has been proposed. We demonstrate that the refinement of network construction together with the study of prevalence of different motifs allows a full explosion of the evolving period doubling cascade route to chaos in both discrete and continuous dynamical systems. Further, this links the phase space time series topologies to the corresponding network topologies, and thus helps to understand the empirical "superfamily" phenomenon, as shown by Xu.
Ultrafast time dynamics studies of periodic lattices with free electron laser radiation
Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)
2012-11-01T23:59:59.000Z
It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.
Kafka, K R P; Li, H; Yi, A; Cheng, J; Chowdhury, E A
2015-01-01T23:59:59.000Z
Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripples are observed to form sequentially outward from the groove edge, with the first one forming after 50 ps. A 1-D analytical model of electron heating and surface plasmon polariton (SPP) excitation induced by the interaction of incoming laser pulse with the groove edge qualitatively explains the time-evloution of LIPSS formation.
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
Attractiveness of periodic orbits in parametrically forced systemswith time-increasing friction
Michele Bartuccelli; Jonathan Deane; Guido Gentile
2012-07-18T23:59:59.000Z
We consider dissipative one-dimensional systems subject to a periodic force and study numerically how a time-varying friction affects the dynamics. As a model system, particularly suited for numerical analysis, we investigate the driven cubic oscillator in the presence of friction. We find that, if the damping coefficient increases in time up to a final constant value, then the basins of attraction of the leading resonances are larger than they would have been if the coefficient had been fixed at that value since the beginning. From a quantitative point of view, the scenario depends both on the final value and the growth rate of the damping coefficient. The relevance of the results for the spin-orbit model are discussed in some detail.
Downstream asymptotics in exterior domains: from stationary wakes to time periodic flows
G. van Baalen
2004-11-04T23:59:59.000Z
We consider the time-dependent Navier-Stokes equations in a half-space with boundary data on the line $(x,y)=(x_0,y)$ assumed to be time-periodic (or stationary) with a fixed asymptotic velocity ${\\bf u}_{\\infty}=(1,0)$ at infinity. We show that there exist (locally) unique solutions for all data satisfying a compatibility condition in a certain class of fuctions. Furthermore, we prove that asymptotically the vorticity decompose itself in a dominant stationary part on the parabolic scale $y\\sim\\sqrt{x}$ and corrections of order $x^{-{3/2}+\\epsilon}$, while the velocity field decompose itself in a dominant stationary part in form of an explicit multiscale expansion on the scales $y\\sim\\sqrt{x}$ and $y\\sim x$ and corrections decaying at least like $x^{-{9/8}+\\epsilon}$. The asymptotic fields are made of linear combinations of universal functions with coefficients depending mildly on the boundary data. The asymptotic expansion for the component parallel to ${\\bf u}_{\\infty}$ contains `non-trivial' terms in the parabolic scale with amplitude $\\ln(x)x^{-1}$ and $x^{-1}$. To first order, our results also imply that time-periodic wakes behave like stationary ones as $x\\to\\infty$. The class of functions used is `natural' in the sense that `Physically Reasonable' (in the sense of Finn & Smith) stationary solutions of the N.-S. equations around an obstacle are covered if the half-space is choosen sufficiently far downstream. The coefficients appearing in the asymptotics may then be linearly related to the net force acting on the obstacle. To our knowledge, it is the first time that estimates uncovering the $\\ln(x)x^{-1}$ correction are proved in this setting.
On 3D instabilities of 2D time-periodic flows - Department of ...
The Karman vortex street, the 2D periodically shedding wake of a circular cylinder, is the prototypical example. We shall consider this as well as a periodically ...
A study of short-time periodic variation of the B8 solar neutrino flux at Super-Kamiokande
J. Yoo; for the Super-Kamiokande Collaboration
2003-09-15T23:59:59.000Z
Super-Kamiokande(SK) is a real-time detector capable of measuring the exact time of solar neutrino events. This, combined with a relatively high yield of these events of roughly 15 per day, allows a search for short-time variations in the observed flux. Using all 1496 days of SK-I's solar data, we looked for periodic variations of the observed solar neutrino flux, and found no significant periodicity.
DOI: 10.1126/science.1149308 , 1895 (2007);318Science
2007-01-01T23:59:59.000Z
of the nanotube bundles carry an equal share of the load, resulting in both lower fracture strength and decreased by different methods. As some laboratories have not recorded the density of their fibers, we have made this
Internal Space-time Symmetries of Particles derivable from Periodic Systems in Optics
Y. S. Kim
2010-09-26T23:59:59.000Z
While modern optics is largely a physics of harmonic oscillators and two-by-two matrices, it is possible to learn about some hidden properties of the two-by-two matrix from optical systems. Since two-by-two matrices can be divided into three conjugate classes depending on their traces, optical systems force us to establish continuity from one class to another. It is noted that those three classes are equivalent to three different branches of Wigner's little groups dictating the internal space-time symmetries massive, massless, and imaginary-mass particles. It is shown that the periodic systems in optics can also be described by have the same class-based matrix algebra. The optical system allow us to make continuous, but not analytic, transitions from massiv to massless, and massless to imaginary-mass cases.
Changes in the American Interventional Radiology Literature: Comparison over a 10-Year Time Period
Ray, Charles E., E-mail: cray@dhha.org; Gupta, Rajan; Blackwell, John [Denver Health Medical Center, Department of Radiology (United States)
2006-08-15T23:59:59.000Z
Purpose. To determine the changes that occurred regarding interventional radiologic research in the major American radiology journals between 1992-1993 and 2002-2003. Methods. Articles published in three major American radiology journals (Journal of Vascular and Interventional Radiology, American Journal of Roentgenology, and Radiology) during two distinct 24-month time periods (1992-1993 and 2002-2003) were evaluated. All articles judged to be pertinent to the interventional radiologic community were included. Investigations included in journal subheadings other than 'interventional' or 'vascular radiology' were included if the emphasis of the article was on a vascular imaging modality or peripheral intervention. Exclusions included: case reports, technical reports, letters to the editor, breast interventions, and primary neurointerventions. Data were collected regarding the affiliations of the primary author (nationality, hospital type, department); primary category of interest of the investigation; funding information; and study design variables. Two-by-two chi-squared statistical analyses were performed comparing the variables from the early and late data sets. Results. A total of 405 articles met the inclusion criteria for the early data set (1992-1993); 488 articles met the inclusion criteria for the late data set (2002-2003). Variables that demonstrated a statistically significant decrease from the early data set to the late data set included: articles in which the primary author was from a department of radiology (91.1% vs. 86.3%; p < 0.025); articles written by a primary author who was American (69.4% vs. 44.6%; p < 0.001); and articles with a primary category of investigation that had a nonvascular intervention focus (22.7% vs. 11.9%; p < 0.001). Variables that demonstrated a statistically significant increase from the early data set to the late data set included primary authors from Western Europe (18.0% vs. 30.1%; p < 0.001) and Asia (6.6% vs. 18.4%; p < 0.001), the primary field of investigation, with significant increases noted for primary cancer interventions (6.5% vs. 13.3%; p < 0.001), gynecologic interventions (0.2% vs. 4.5%; p < 0.001), stent-grafts (0 vs. 2.9%; p < 0.001), and spine interventions (0 vs. 1.8%; p < 0.01). Studies receiving funding also demonstrated a significant increase when comparing the early and late data sets (11.3% vs. 23.0%, respectively; p < 0.001). Conclusions. Articles published in the American radiologic literature have changed significantly over the past 10 years. Primary authors are more likely to be nonradiologists and less likely to be American. Investigations dealing primarily with nonvascular interventions are less common; however, some forms of intervention (particularly cancer interventions) are seen more frequently in the literature. The percentage of funded projects has more than doubled in the same time frame.
A (MAX,+) ALGEBRA FOR NON-STATIONARY PERIODIC TIMED DISCRETE EVENT Guillaume P. Brat,1
Garg, Vijay
], behaviors of DES are captured by timed event graphs (TEG), a class of timed Petri nets ( 9] o ers a comprehensive review of Petri nets). In TEGs, any place has only one input and one out- put transition, and. Event sequences consist of the r- ing times of transitions. A TEG with N transitions is represented
Looking for granulation and periodicity imprints in the sunspot time series
Lopes, Ilidio
2015-01-01T23:59:59.000Z
The sunspot activity is the end result of the cyclic destruction and regeneration of magnetic fields by the dynamo action. We propose a new method to analyze the daily sunspot areas data recorded since 1874. By computing the power spectral density of daily data series using the Mexican hat wavelet, we found a power spectrum with a well-defined shape, characterized by three features. The first term is the 22 yr solar magnetic cycle, estimated in our work to be of 18.43 yr. The second term is related to the daily volatility of sunspots. This term is most likely produced by the turbulent motions linked to the solar granulation. The last term corresponds to a periodic source associated with the solar magnetic activity, for which the maximum of power spectral density occurs at 22.67 days. This value is part of the 22-27 day periodicity region that shows an above-average intensity in the power spectra. The origin of this 22.67 day periodic process is not clearly identified, and there is a possibility that it can be...
The long time behavior of Brownian motion in tilted periodic potentials
Liang Cheng
2015-01-20T23:59:59.000Z
Jan 6, 2015 ... In order to obtain more quantitative information about dynamical behaviors, we .... 2. Convergence of long time average velocity VF for the ...
A charged particle in a homogeneous magnetic field accelerated by a time periodic Aharonov-Bohm flux
T. Kalvoda; P. Stovicek
2011-07-14T23:59:59.000Z
We consider a nonrelativistic quantum charged particle moving on a plane under the influence of a uniform magnetic field and driven by a periodically time-dependent Aharonov-Bohm flux. We observe an acceleration effect in the case when the Aharonov-Bohm flux depends on time as a sinusoidal function whose frequency is in resonance with the cyclotron frequency. In particular, the energy of the particle increases linearly for large times. An explicit formula for the acceleration rate is derived with the aid of the quantum averaging method, and then it is checked against a numerical solution with a very good agreement.
Periodic Charging Scheme for Fixed-Priority Real-Time Systems with Renewable Energy
Aydin, Hakan
, the deployed systems use solar panels and piezoelectric units, that exploit solar energy and mechani- cal of the day and season in the case of solar energy); but its rate of supply is not necessarily uniform: the system is not able to harvest solar energy at night time, and energy harvesting rate will vary during
Time delays in quasi-periodic pulsations observed during the X2.2 solar flare on 2011 February 15
Dolla, L; Seaton, D B; Van Doorsselaere, T; Dominique, M; Berghmans, D; Cabanas, C; De Groof, A; Schmutz, W; Verdini, A; West, M J; Zender, J; Zhukov, A N
2012-01-01T23:59:59.000Z
We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on time scale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the Extreme Ultra-Violet (EUV) channels of the Euv SpectroPhotometer (ESP) onboard the Solar Dynamic Observatory (SDO). The Zirconium and Aluminum filter channels of the Large Yield Radiometer (LYRA) onboard the Project for On-Board Autonomy (PROBA2) satellite and the SXR channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite (GOES), where the channel at 1-8 {\\AA} leads the 0.5-4 {\\AA} channel by several seconds. The time lags between the first and last channels is up to 9 ...
TIME DELAYS IN QUASI-PERIODIC PULSATIONS OBSERVED DURING THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15
Dolla, L.; Marque, C.; Seaton, D. B.; Dominique, M.; Berghmans, D.; Cabanas, C.; De Groof, A.; Verdini, A.; West, M. J.; Zhukov, A. N. [Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels (Belgium); Van Doorsselaere, T. [Centrum voor Plasma-Astrofysica, Department of Mathematics, KULeuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Schmutz, W. [Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf (Switzerland); Zender, J., E-mail: dolla@sidc.be [European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands)
2012-04-10T23:59:59.000Z
We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on timescale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the extreme-ultraviolet (EUV) channels of the Euv SpectroPhotometer (ESP) on board the Solar Dynamic Observatory. The zirconium and aluminum filter channels of the Large Yield Radiometer on board the Project for On-Board Autonomy satellite and the soft X-ray (SXR) channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite, where the channel at 1-8 A leads the 0.5-4 A channel by several seconds. The time lags between the first and last channels is up to Almost-Equal-To 9 s. We identified at least two distinct time intervals during the flare impulsive phase, during which the QPPs were associated with two different sources in the Nobeyama RadioHeliograph at 17 GHz. The radio as well as the hard X-ray channels showed different lags during these two intervals. To our knowledge, this is the first time that time lags are reported between EUV and SXR fluctuations on these timescales. We discuss possible emission mechanisms and interpretations, including flare electron trapping.
Rogers, J.; Porter, K.
2012-03-01T23:59:59.000Z
This paper updates previous work that describes time period-based and other approximation methods for estimating the capacity value of wind power and extends it to include solar power. The paper summarizes various methods presented in utility integrated resource plans, regional transmission organization methodologies, regional stakeholder initiatives, regulatory proceedings, and academic and industry studies. Time period-based approximation methods typically measure the contribution of a wind or solar plant at the time of system peak - sometimes over a period of months or the average of multiple years.
Sorenson, Ken B.; Hanson, Brady D.
2013-08-25T23:59:59.000Z
The need for extended storage of used nuclear fuel is increasing globally as disposition schedules for used fuel are pushed further into the future. This is creating a situation where dry storage of used fuel may need to be extended beyond normal regulatory licensing periods. While it is generally accepted that used fuel in dry storage will remain in a safe condition, there is little data that demonstrate used fuel performance in dry storage environments for long periods of time. This is especially true for high burnup used fuel.
Time Series, Load Profiles, Temperature Sensitivity, Weather Adjustment 1 Introduction The quantitative, it is required to use indirect techniques to assess the type of demand they face [10, 11] in order to support their long-term investment planning. In this context, categories of residential, business and in- dustrial
de Avellar, Marcio G B; Altamirano, Diego; Sanna, Andrea; Zhang, Guobao
2015-01-01T23:59:59.000Z
We present an analysis of the energy and frequency dependence of the Fourier time lags of the hectoHertz quasi-periodic oscillations (QPOs) and of the QPOs at the frequency at which the power density spectrum shows a break in the neutron-star low-mass X-ray binary 4U 1636-53, using a large data set obtained with the Rossi X-ray Timing Explorer. We found that: (i) For the break frequency QPO: for low frequencies, in general the time lag is positive, but it is decreasing with increasing frequency, reaching zero lag at 20 Hz. Between 20 and 35 Hz there is a small fluctuation around zero, from where the time lags become positive again and increase slightly above zero up to 65 Hz. (ii) For the hHz QPO: we see that when the frequency is 100 Hz the time lag is negative, but it increases to zero already at 110 Hz, being consistent with this value up to 130 Hz from where it increases to 0.5 msec at around 140 Hz. From 140 Hz the time lag decreases sharply, being strongly negative for hHz greater than 220 Hz. We compar...
Krainev, M B; Kalinin, M S; Svirzhevskaya, A K; Svirzhevsky, N S
2014-01-01T23:59:59.000Z
Using the simple model for the description of the GCR modulation in the heliosphere and the sets of parameters discussed in the accompanying paper we model some features of the time and energy behavior of the GCR intensity near the Earth observed during periods of low solar activity around three last solar minima. In order to understand the mechanisms underlying these features in the GCR behavior, we use the suggested earlier decomposition of the calculated intensity into the partial intensities corresponding to the main processes (diffusion, adiabatic losses, convection and drifts).
Littlefield, Colin; Cain, Ryan; Mumme, Raymond; Magno, Katrina C; Corpuz, Taylor; Sandefur, Davis; Boyd, David; Cook, Michael; Ulowetz, Joseph
2014-01-01T23:59:59.000Z
We report the results of a twenty-five-month photometric campaign studying V1432 Aql, the only known eclipsing, asynchronous polar. Our data show that both the residual eclipse flux and eclipse O-C timings vary strongly as a function of the spin-orbit beat period. Relying upon a new model of the system, we show that cyclical changes in the location of the threading region along the ballistic trajectory of the accretion stream could produce both effects. This model predicts that the threading radius is variable, in contrast to previous studies which have assumed a constant threading radius. Additionally, we identify a very strong photometric maximum which is only visible for half of the beat cycle. The exact cause of this maximum is unclear, but we consider the possibility that it is the optical counterpart of the third accreting polecap proposed by Rana et al. (2005). Finally, the rate of change of the white dwarf's spin period is consistent with it being proportional to the difference between the spin and or...
Hettinger, T; Strader, J; Bickerton, S J; Beers, T C
2015-01-01T23:59:59.000Z
Stellar multiplicity lies at the heart of many problems in modern astrophysics, including the physics of star formation, the observational properties of unresolved stellar populations, and the rates of interacting binaries such as cataclysmic variables, X-ray binaries, and Type Ia supernovae. However, little is known about the stellar multiplicity of field stars in the Milky Way, in particular about the differences in the multiplicity characteristics between metal-rich disk stars and metal-poor halo stars. In this study we perform a statistical analysis of ~15,000 F-type dwarf stars in the Milky Way through time-resolved spectroscopy with the sub-exposures archived in the Sloan Digital Sky Survey. We obtain absolute radial velocity measurements through template cross-correlation of individual sub-exposures with temporal baselines varying from minutes to years. These sparsely sampled radial velocity curves are analyzed using Markov chain Monte Carlo techniques to constrain the very short-period binary fraction...
Regular simplex and periodic billiard orbit
Bedaride, Nicolas
2011-01-01T23:59:59.000Z
We consider billiard inside regular simplex of $\\mathbb{R}^n$. We show the existence of two periodic trajectories. One of period $n+1$ which passes one time by each face and one of period $2n$ which passes $n$ times through one face and one time through each other face. In both cases we obtain exact coordinates for the periodic points.
Burleson, Kenneth Stewart
1958-01-01T23:59:59.000Z
pigures 7 through 15) and their cenbinad effects on the a~receive strengths of stem cured concrete are presente4 in Table 1. TABLI 1. Cenhinations of HoMag Tines ~ Curing Tenperatures, aad Optima Treatssnt Periods, and Their Conhined gffects.... The optima holding tine for tenperatures of 140, 165 and 165 F to obtain ths aaxiaun nodulus of elasticity for a treatasnt period of 16 hours is indicated in Figures 42 through 45. k treatnent peried of 16 hours was used in plotting these ourves, because...
Hinow, Peter
Summary Matrix tablets are drug delivery devices that release a water-soluble drug over an extended period of time. Such matrix tablets are formulated from mixtures of drug, polymer, and excipient powders variation in the drug release profile of the tablet. While fabrication of experimental tablets
Peak, Derek
Position Title: Community Service-Learning Student Mentor Terms: Part-time Casual position Reporting to the Engaged Learning Coordinator, and working collaboratively with another CSL Student Mentor, the CSL Student Mentor will be responsible for the facilitation of the STM Service & Justice Project (SJP
Alavi, Ali
is a good idea are: · efficient development practices. It is very easy to try things out and experiment of time, including writing papers and theses as well as writing code. This session gives a introduction communication via a central server which stores the repository whereas a DVCS is completely distributed and each
A highly specific test for periodicity
Ansmann, Gerrit
2015-01-01T23:59:59.000Z
We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincar\\'e sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its run time grows asymptotically linear with the length of the time series.
Optimal Checkpointing Period: Time vs. Energy
Paris-Sud XI, Université de
is focusing on the characteris- tics, features, and challenges of High Performance Computing (HPC) systems-purpose error recovery technique in high performance computing is checkpoint and rollback recovery
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Protection Obeying Environmental Laws Individual Permit Storm Water Analytical Period Storm Water Analytical Period The Individual Permit authorizes the discharge of storm...
Genealogy of periodic trajectories
de Adguiar, M.A.M.; Maldta, C.P.; de Passos, E.J.V.
1986-05-20T23:59:59.000Z
The periodic solutions of non-integrable classical Hamiltonian systems with two degrees of freedom are numerically investigated. Curves of periodic families are given in plots of energy vs. period. Results are presented for this Hamiltonian: H = 1/2(p/sub x//sup 2/ + p/sub y//sup 2/) + 1/2 x/sup 2/ + 3/2 y/sup 2/ - x/sup 2/y + 1/12 x/sup 4/. Properties of the families of curves are pointed out. (LEW)
Fourier series and periodicity
Donal F. Connon
2014-12-07T23:59:59.000Z
A large number of the classical texts dealing with Fourier series more or less state that the hypothesis of periodicity is required for pointwise convergence. In this paper, we highlight the fact that this condition is not necessary.
DEVELOPMENT OF RASASASTRA IN MEDIEVAL PERIOD*
Harishankar Sharma
1984-01-01T23:59:59.000Z
ABSTRACT: The paper deals with the historical development of Rasasastra in Medieval period. Knowledge of Rasa has been in existence from the time immemorial. Exploration of natural resources for the benefit of human beings is the object of this therapy. It is a medical science recognized during vedic periods for the betterment of even Devas. Medieval period can be treated as a golden age for the development of this science. Looking at its aim and objects, methodology and therapeutics, it was recognized as a medical science with an independent philosophical background in 14 th century, by Madhavacharya in his Sarva Darsana Samgraha.
PERIODIC WAVELET TRANSFORMS AND PERIODICITY JOHN J. BENEDETTO AND G
Benedetto, John J.
PERIODIC WAVELET TRANSFORMS AND PERIODICITY DETECTION JOHN J. BENEDETTO #3; AND G OTZ E. PFANDER y Key words. Continuous wavelet transform, epileptic seizure prediction, periodicity detection algorithm, optimal generalized Haar wavelets, wavelet frames on Z. AMS subject classi#12;cations. 42C99, 42C
Quantum transport calculations using periodic boundaryconditions
Wang, Lin-Wang
2004-06-15T23:59:59.000Z
An efficient new method is presented to calculate the quantum transports using periodic boundary conditions. This method allows the use of conventional ground state ab initio programs without big changes. The computational effort is only a few times of a normal groundstate calculations, thus is makes accurate quantum transport calculations for large systems possible.
Kepler and the long-period variables
Hartig, Erich; Lebzelter, Thomas [University of Vienna, Department of Astrophysics, Türkenschanzstrasse 17, A-1180 Vienna (Austria); Cash, Jennifer [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7024, Orangeburg, SC 29117 (United States); Hinkle, Kenneth H.; Mighell, Kenneth J. [National Optical Astronomy Observatories, P.O. Box 26732, Tucson, AZ 85726 (United States); Walter, Donald K., E-mail: erich.hartig@univie.ac.at, E-mail: thomas.lebzelter@univie.ac.at, E-mail: jcash@physics.scsu.edu, E-mail: hinkle@noao.edu, E-mail: mighell@noao.edu, E-mail: dkw@physics.scsu.edu [Department of Biological and Physical Sciences, South Carolina State University, P.O. Box 7296, Orangeburg, SC 29117 (United States)
2014-12-01T23:59:59.000Z
High-precision Kepler photometry is used to explore the details of asymptotic giant branch (AGB) light curves. Since AGB variability has a typical timescale on the order of a year, we discuss at length the removal of long-term trends and quarterly changes in Kepler data. Photometry for a small sample of nine semi-regular (SR) AGB stars is examined using a 30 minute cadence over a period of 45 months. While undergoing long-period variations of many magnitudes, the light curves are shown to be smooth at the millimagnitude level over much shorter time intervals. No flares or other rapid events were detected on a sub-day timescale. The shortest AGB period detected is on the order of 100 days. All the SR variables in our sample are shown to have multiple modes. This is always the first overtone, typically combined with the fundamental. A second common characteristic of SR variables is shown to be the simultaneous excitation of multiple closely separated periods for the same overtone mode. Approximately half the sample had a much longer variation in the light curve, likely a long secondary period (LSP). The light curves were all well represented by a combination of sinusoids. However, the properties of the sinusoids are time variable, with irregular variations present at low levels. No non-radial pulsations were detected. It is argued that the LSP variation seen in many SR variables is intrinsic to the star and linked to multiple mode pulsation.
The periodicity of the eta Carinae events
A. Damineli; M. F. Corcoran; D. J. Hillier; O. Stahl; R. S. Levenhagen; N. V. Leister; J. H. Groh; M. Teodoro; J. F. Albacete Colombo; F. Gonzalez; J. Arias; H. Levato; M. Grosso; N. Morrell; R. Gamen; G. Wallerstein; V. Niemela
2007-11-27T23:59:59.000Z
Extensive spectral observations of eta Carinae over the last cycle, and particularly around the 2003.5 low excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and well defined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of 2022.7+-1.3 d. Spectroscopic data collected during the last 60 years yield an average period of 2020+-4 d, consistent with the present day period. The period cannot have changed by more than $\\Delta$P/P=0.0007 since 1948. This confirms the previous claims of a true, stable periodicity, and gives strong support to the binary scenario. We have used the disappearance of the narrow component of HeI 6678 to define the epoch of the Cycle 11 minimum, T_0=JD 2,452,819.8. The next event is predicted to occur on 2009 January 11 (+-2 days). The dates for the start of the minimum in other spectral features and broad-bands is very close to this date, and have well determined time delays from the HeI epoch.
Thermo-quantum diffusion in periodic potentials
R. Tsekov
2012-01-18T23:59:59.000Z
Quantum Brownian motion in a periodic cosine potential is studied and a simple estimate of the tunneling effect is obtained in the frames of a quasi-equilibrium semiclassical approach. It is shown that the latter is applicable for heavy particles but electrons cannot be described properly since the quantum effects dominate over the thermal ones. The purely quantum electron diffusion is investigated at zero temperature and demonstrates that electrons do not obey the classical Einstein law of Brownian motion in the field of periodic potentials, since the dispersion of the wave packet increases logarithmically in time.
Representing Periodic Functions by Fourier
Vickers, James
Representing Periodic Functions by Fourier Series 23.2 Introduction In this Section we show how, then the Fourier series expansion takes the form: f(t) = a0 2 + n=1 (an cos nt + bn sin nt) Our main purpose here Fourier coefficients of a function of period 2 calculate Fourier coefficients of a function of general
Convection, granulation and period jitter in classical Cepheids
Neilson, Hilding R
2014-01-01T23:59:59.000Z
Analyses of recent observations of the sole classical Cepheid in the Kepler field, V1154 Cygni, found random changes of about 30 minutes in the pulsation period. These period changes challenge standard theories of pulsation and evolution because the period change is non-secular, and explaining this period jitter is necessary for understanding stellar evolution and the role of Cepheids as precise standard candles. We suggest that convection and convective hot spots can explain the observed period jitter. Convective hot spots alter the timing of flux maximum and minimum in the Cepheid light curve, hence change the measured pulsation period. We present a model of random hot spots that generate a localized flux excess that perturbs the Cepheid light curve and consequently the pulsation period which is consistent with the observed jitter. This result demonstrates how important understanding convection is for modeling Cepheid stellar structure and evolution, how convection determines the red edge of the instability...
The long time behavior of diffusion in tilted periodic potentials
2013-09-18T23:59:59.000Z
Sep 18, 2013 ... In order to obtain more quantitative information about dynamical .... per(T),r = 1,2, denotes the space of the restriction to T of functions in Cr(R) ...
Emissions from Idling Trucks for Extended Time Periods | Department of
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
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 DataDepartment of Energy Your Density Isn't Your Destiny:RevisedAdvisoryStandard | Department ofEmily Knouse About UsEnergy Idling
Mechanics of planar periodic microstructures
Prange, Sharon M. (Sharon Marie)
2007-01-01T23:59:59.000Z
The deformation of two-dimensional periodically patterned elastomeric sheets has been shown to trigger interesting pattern changes that are both repeatable and predictable (Bertoldi et al., 2007). Here, both square and ...
Competitive Multi-period Pricing with Fixed Inventories
Perakis, Georgia
This paper studies the problem of multi-period pricing for perishable products in a competitive (oligopolistic) market. We study non cooperative Nash equilibrium policies for sellers. At the beginning of the time horizon, ...
activity rules periodic: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
WITH PERIODIC ACTIVE THERMAL IMAGING Physics Websites Summary: methods where the thermal evolution of a scene is recorded while some external time varying energyIMPACT OF A LOSSY...
Chaotic Transport in Planar Periodic Vortical Flows
Taehoon Ahn; Seunghwan Kim
1993-09-24T23:59:59.000Z
We have studied a chaotic transport in a two-dimensional periodic vortical flow under a time-dependent perturbation with period T where the global diffusion occurs along the stochastic web. By using the Melnikov method we construct the separatrix map describing the approximate dynamics near the saddle separatrices. Focusing on the small T, the width of the stochastic layer is calculated analytically by using the residue criterion and the diffusion constant by using the random phase assumption and correlated random walks. The analytical results are in good agreements with the results of two different types of numerical simulations by integrations of the Hamilton's equation of motion and by iterations of the separatrix map, which establishes the validity of the use of the separatrix map.
Down hole periodic seismic generator
Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)
1989-01-01T23:59:59.000Z
A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
Advanced downhole periodic seismic generator
Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)
1991-07-16T23:59:59.000Z
An advanced downhole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
Periodic table for topological insulators and superconductors
Alexei Kitaev
2009-01-20T23:59:59.000Z
Gapped phases of noninteracting fermions, with and without charge conservation and time-reversal symmetry, are classified using Bott periodicity. The symmetry and spatial dimension determines a general universality class, which corresponds to one of the 2 types of complex and 8 types of real Clifford algebras. The phases within a given class are further characterized by a topological invariant, an element of some Abelian group that can be 0, Z, or Z_2. The interface between two infinite phases with different topological numbers must carry some gapless mode. Topological properties of finite systems are described in terms of K-homology. This classification is robust with respect to disorder, provided electron states near the Fermi energy are absent or localized. In some cases (e.g., integer quantum Hall systems) the K-theoretic classification is stable to interactions, but a counterexample is also given.
Planar resonant periodic orbits in Kuiper belt dynamics
George Voyatzis; Thomas Kotoulas
2005-02-28T23:59:59.000Z
In the framework of the planar restricted three body problem we study a considerable number of resonances associated to the Kuiper Belt dynamics and located between 30 and 48 a.u. Our study is based on the computation of resonant periodic orbits and their stability. Stable periodic orbits are surrounded by regular librations in phase space and in such domains the capture of trans-Neptunian object is possible. All the periodic orbits found are symmetric and there is evidence for the existence of asymmetric ones only in few cases. In the present work first, second and third order resonances are under consideration. In the planar circular case we found that most of the periodic orbits are stable. The families of periodic orbits are temporarily interrupted by collisions but they continue up to relatively large values of the Jacobi constant and highly eccentric regular motion exists for all cases. In the elliptic problem and for a particular eccentricity value of the primary bodies the periodic orbits are isolated. The corresponding families, where they belong to, bifurcate from specific periodic orbits of the circular problem and seem to continue up to the rectilinear problem. Both stable and unstable orbits are obtained for each case. In the elliptic problem the unstable orbits found are associated with narrow chaotic domains in phase space. The evolution of the orbits, which are located in such chaotic domains, seems to be practically regular and bounded for long time intervals.
Quality of monitoring of stochastic events by periodic and ...
David K. Y. Yau, Nung Kwan Yip, Chris Y. T. Ma, Nageswara S. V. Rao, Mallikarjun Shankar
2010-08-28T23:59:59.000Z
infeasible to transmit sensor data over long distances, or in an underground system of ... the case of static sensors, their placement to best protect people has been ... function of the event dynamics and type of events: (1) What is the QoM of a ... a class of periodic coverage algorithms considering the travel time overhead.
Periodic relativity: basic framework of the theory
Vikram H. Zaveri
2014-11-25T23:59:59.000Z
An alternative gravity theory is proposed which does not rely on Riemannian geometry and geodesic trajectories. The theory named periodic relativity (PR) does not use the weak field approximation and allows every two body system to deviate differently from the flat Minkowski metric. PR differs from general relativity (GR) in predictions of the proper time intervals of distant objects. PR proposes a definite connection between the proper time interval of an object and gravitational frequency shift of its constituent particles as the object travels through the gravitational field. PR is based on the dynamic weak equivalence principle which equates the gravitational mass with the relativistic mass. PR provides very accurate solutions for the Pioneer anomaly and the rotation curves of galaxies outside the framework of general relativity. PR satisfies Einstein's field equations with respect to the three major GR tests within the solar system and with respect to the derivation of Friedmann equation in cosmology. This article defines the underlying framework of the theory.
DEVELOPING IMPROVED TRAVEL TIME RELIABILITY MEASURES FOR REAL-TIME AND ARCHIVED ITS DATA
Bertini, Robert L.
including travel time, 95th percentile travel time, travel time index, buffer index planning time index-based detector data, collected in periodic special studies, or estimated using simulation [1,3]: 95th Percentile between 95th percentile travel time and mean travel time, divided by mean travel time. Planning Time Index
Period Change of Eclipsing Binaries from the ASAS Catalog
Radoslaw Poleski; Bogumil Pilecki
2006-07-10T23:59:59.000Z
We present a preliminary statistical analysis of a period change of eclipsing binaries from the ASAS Catalog of Variable Stars. For each contact and semidetached system brighter than 13.3$mag$ (in V) with a period shorter than 0.4 days and at least 300 observation points we have found an angular velocity $\\omega$ and its time derivative $\\frac{d\\omega}{dt}$. According to our accuracy there is no evidence that average $\\frac{d\\omega}{dt}$ differs from 0. Light curves for selected stars are presented.
Phase transitions in full counting statistics for periodic pumping
Dmitri A. Ivanov; Alexander G. Abanov
2010-07-16T23:59:59.000Z
We discuss the problem of full counting statistics for periodic pumping. The probability generating function is usually defined on a circle of the "physical" values of the counting parameter, with its periodicity corresponding to charge quantization. The extensive part of the generating function can either be an analytic function on this circle or have singularities. These two cases may be interpreted as different thermodynamic phases in time domain. We discuss several examples of phase transitions between these phases for classical and quantum systems. Finally, we prove a criterion for the "analytic" phase in the problem of a quantum pump for noninteracting fermions.
Seismic isolation of two dimensional periodic foundations
Yan, Y.; Mo, Y. L., E-mail: yilungmo@central.uh.edu [University of Houston, Houston, Texas 77004 (United States); Laskar, A. [Indian Institute of Technology Bombay, Powai, Mumbai (India); Cheng, Z.; Shi, Z. [Beijing Jiaotong University, Beijing (China); Menq, F. [University of Texas, Austin, Texas 78712 (United States); Tang, Y. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2014-07-28T23:59:59.000Z
Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5?Hz to 50?Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.
Fully Polynomial Time Approximation Schemes for Stochastic ...
2014-09-03T23:59:59.000Z
Jun 13, 2013 ... In each time period, she can consume some of her capital, and the ... utility is derived from her consumption based on an underlying utility ...
Optimized Periodic Control of Chaotic Systems
Robert Mettin; Thomas Kurz
1995-05-09T23:59:59.000Z
In this work, we demonstrate the open-loop control of chaotic systems by means of optimized periodic signals. The use of such signals enables us to reduce control power significantly in comparison to simple harmonic perturbations. It is found that the stabilized periodic dynamics can be changed by small, specific alterations of the control signal. Thus, low power switching between different periodic states can be achieved without feedback. The robustness of the proposed control method against noise is discussed.
Pricing Conspicuous Consumption Products in Recession Periods ...
2012-09-26T23:59:59.000Z
cally used in chemical engineering, e.g., to avoid irreversible reactions in ... Our basic problem is based on an economic setting with a recession period followed.
Broadband solar absorption enhancement via periodic
Province, 230009, P. R. China. Solution processed colloidal quantum dot (CQD) solar cells have greatBroadband solar absorption enhancement via periodic nanostructuring of electrodes Michael M. Adachi demonstrate a bottom- illuminated periodic nanostructured CQD solar cell that enhances broadband absorption
Metallurgy Department Progress Report for the Period
Dlcfc^ooWS imsm "-"' Metallurgy Department Progress Report for the Period 1 January to 31 December 1962 (Uw National Laboratory, DK-4000 Roskilde, Denmark July 1963 #12;Risř-R-486 METALLURGY DEPARTMENT PROGRESS REPORT FOR THE PERIOD 1 JANUARY TO 31 DECEMBER 1982 Abstract. The activities of the Metallurgy
Large Scale Periodicity in Redshift Distribution
K. Bajan; M. Biernacka; P. Flin; W. Godlowski; V. Pervushin; A. Zorin
2004-08-30T23:59:59.000Z
We review the previous studies of galaxies and quasar redshifts discretisation. We present also the investigations of the large scale periodicity, detected by pencil--beam observations, which revealed 128 (1/h) Mpc period, afterwards confirmed with supercluster studies. We present the theoretical possibility of obtaining such a periodicity using a toy-model. We solved the Kepler problem, i.e. the equation of motion of a particle with null energy moving in the uniform, expanding Universe, decribed by FLRW metrics. It is possible to obtain theoretically the separation between large scale structures similar to the observed one.
Variable-Period Undulators For Synchrotron Radiation
Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)
2005-02-22T23:59:59.000Z
A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.
PERIODIC WAVELET TRANSFORMS AND PERIODICITY JOHN J. BENEDETTO AND GOTZ E. PFANDER
Pfander, GĂ¶tz
PERIODIC WAVELET TRANSFORMS AND PERIODICITY DETECTION JOHN J. BENEDETTO AND GÂ¨OTZ E. PFANDER Key words. Continuous wavelet transform, epileptic seizure prediction, periodicity detection algorithm, optimal generalized Haar wavelets, wavelet frames on Z. AMS subject classifications. 42C99, 42C40
Paris-Sud XI, UniversitĂ© de
periods often appear in industry due to a machine breakdown (stochastic) or preventive maintenance of machine unavailability. However, in some cases (e.g. preventive maintenance), the maintenance of a machineSingle-machine scheduling with periodic and exible periodic maintenance to minimize maximum
Impact of Motor Failures on Payback Periods
Cheek, K. F.; Pillay, P.; Dudley, K. J.
This paper uses MotorMaster and Vaughen's Complete Price Guide to determine payback periods for different motor failure scenarios. Some scenarios considered are rewinds, reconditions, and replacement of bearings. Prices for these repairs...
Enforcement Policy Statement: Compliance Period for Regional...
Broader source: Energy.gov (indexed) [DOE]
Compliance Period for Regional Standards Applicable to Central Air Conditioners April 24, 2014 On June 27, 2011, the U.S. Department of Energy (DOE) published in the Federal...
Analytical homogenization method for periodic composite materials
Chen, Ying
We present an easy-to-implement technique for determining the effective properties of composite materials with periodic microstructures, as well as the field distributions in them. Our method is based on the transformation ...
Roberts, Tony D.
For the first time to our knowledge, continuous nonsegmented channel waveguides in periodically poled KTiOPO4 with guided orthogonal polarizations are used to demonstrate type II background-free second harmonic generation ...
Periodic forcing of graphene as geometric ripples on its surface
Tridev Mishra; Tapomoy Guha Sarkar; Jayendra N. Bandyopadhyay
2014-10-27T23:59:59.000Z
We explore the possibility of using modulated high frequency periodic driving of mono-layer graphene to create effects of curved geometry. The low energy continuum limit of graphene is modeled using Dirac equation in (2+1) dimensions. We suggest that the modifications to the Dirac equation when written in a curved background space can also be induced by a suitable driving scheme. The time dependent system yields, in the approximate limit of high frequency pulsing, an effective time independent Hamiltonian that governs the time evolution, except for an initial and a final kick. We use a specific form of 4-phase pulsed forcing with suitably tuned choice of modulating operators to mimic the effects of weak metric perturbations and thereby effectively induce mild wrinkles on the surface. The strength of the perturbation is found to be directly related to omega^{-1} the time period of the driving field at the leading order. We apply the method to engineer some specific `nearly flat' metrics and we find that the imprint of curvilinear geometry modifies the band structure significantly. The emergence of band gap at the Dirac point is crucial in this regard. We suggest that this method shall be useful in studying the response of various properties of such materials to non-trivial geometry without requiring any actual physical deformations.
Desingularization of periodic vortex sheet roll-up
Krasny, R.
1986-08-01T23:59:59.000Z
The equations governing periodic vortex sheet roll-up from analytic initial data are desingularized. Linear stability analysis shows that this diminishes the vortex sheet model's short wavelength instability, yielding a numerically more tractable set of equations. Computational evidence is presented which indicates that this approximation converges, beyond the critical time of singularity formation in the vortex sheet, if the mesh is refined and the smoothing parameter is reduced in the proper order. The results suggest that the vortex sheet rolls up into a double branched spiral past the critical time. It is demonstrated that either higher machine precision or a spectra filter can be used to maintain computational accuracy as the smoothing parameter is decreased. Some conjectures on the model's long time asymptotic state are given.
Periodic subsystem density-functional theory
Genova, Alessandro; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Ceresoli, Davide [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); CNR-ISTM, Institute of Molecular Sciences and Technologies, Milano (Italy)
2014-11-07T23:59:59.000Z
By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.
Caticha, Ariel [Department of Physics, University at Albany-SUNY, Albany, NY 12222 (United States)
2011-03-14T23:59:59.000Z
The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.
Holographic classification of Topological Insulators and its 8-fold periodicity
André LeClair; Denis Bernard
2012-05-16T23:59:59.000Z
Using generic properties of Clifford algebras in any spatial dimension, we explicitly classify Dirac hamiltonians with zero modes protected by the discrete symmetries of time-reversal, particle-hole symmetry, and chirality. Assuming the boundary states of topological insulators are Dirac fermions, we thereby holographically reproduce the Periodic Table of topological insulators found by Kitaev and Ryu. et. al, without using topological invariants nor K-theory. In addition we find candidate Z_2 topological insulators in classes AI, AII in dimensions 0,4 mod 8 and in classes C, D in dimensions 2,6 mod 8.
5. Wavelengths and periods of field motions
Finlay, Christopher
. Using a technique based on the Radon transform [2], we determined the amount of power propagating5. Wavelengths and periods of field motions 2D frequency-wavenumber (FK) power spectra were of the large scale magnetic field at the surface of the core. Here we deconstruct such a model (gufm1
clock period selection method slack minimization criteria
California at Irvine, University of
An optimal clock period selection method based on slack minimization criteria EnShou Chang Daniel the effect of clock slack on the performance of designs and present an algorithm to find a slack]: allocation, scheduling and binding. The purpose of alloca tion is to determine the number of resources
Utility Building Analysis Billing Period: NOV -2013
Ciocan-Fontanine, Ionut
ELECTRICITY Consumption MUNICIPAL WATER Consumption 8 CCF STEAM Consumption CHILLED WATER Consumption GAS Building Analysis Billing Period: NOV - 2013 032 JACKSON HALL: 150,393 Square Feet ELECTRICITY Consumption,550 Square Feet ELECTRICITY Consumption 114,185 KWHRS MUNICIPAL WATER Consumption 1,423 CCF STEAM Consumption
Student Job Review Questionnaire / Periodic Survey
Amin, S. Massoud
Student Job Review Questionnaire / Periodic Survey FOR OHR USE ONLY No Change Date Received JRQ Number Notice Number Job Family Title Job Family Number New Pay Rate/Range Certifiable Yes No Effective Date Approved for Notice Letter Date Notice Mailed Job Review Questionnaire (JRQ) (Student Request
Magnetic field gradients in solar wind plasma and geophysics periods
A. Bershadskii
2006-11-16T23:59:59.000Z
Using recent data obtained by Advanced Composition Explorer (ACE) the pumping scale of the magnetic field gradients of the solar wind plasma has been calculated. This pumping scale is found to be equal to 24h $\\pm$ 2h. The ACE spacecraft orbits at the L1 libration point which is a point of Earth-Sun gravitational equilibrium about 1.5 million km from Earth. Since the Earth's magnetosphere extends into the vacuum of space from approximately 80 to 60,000 kilometers on the side toward the Sun the pumping scale cannot be a consequence of the 24h-period of the Earth's rotation. Vise versa, a speculation is suggested that for the very long time of the coexistence of Earth and of the solar wind the weak interaction between the solar wind and Earth could lead to stochastic synchronization between the Earth's rotation and the pumping scale of the solar wind magnetic field gradients. This synchronization could transform an original period of the Earth's rotation to the period close to the pumping scale of the solar wind magnetic field gradients.
Elsevier Journal Specific Embargo Periods 2013 Journal Name Issn Embargo Period
Ayala-Rincón, Mauricio
Elsevier Journal Specific Embargo Periods 2013 Journal Name Issn Embargo Period ACADEMIC PEDIATRICS 18762859 12 ACADEMIC RADIOLOGY 10766332 12 ACC CARDIOSOURCE REVIEW JOURNAL 15568571 12 ACCIDENT ANALYSIS 18759637 24 AEROSPACE SCIENCE AND TECHNOLOGY 12709638 24 AESTHETIC SURGERY JOURNAL 1090820X 12 AESTHETISCHE
Periodically-driven quantum matter: the case of resonant modulations
N. Goldman; J. Dalibard; M. Aidelsburger; N. R. Cooper
2015-03-06T23:59:59.000Z
Quantum systems can show qualitatively new forms of behavior when they are driven by fast time-periodic modulations. In the limit of large driving frequency, the long-time dynamics of such systems can often be described by a time-independent effective Hamiltonian, which is generally identified through a perturbative treatment. Here, we present a general formalism that describes time-modulated physical systems, in which the driving frequency is large, but resonant with respect to energy spacings inherent to the system at rest. Such a situation is currently exploited in optical-lattice setups, where superlattice (or Wannier-Stark-ladder) potentials are resonantly modulated so as to control the tunneling matrix elements between lattice sites, offering a powerful method to generate artificial fluxes for cold-atom systems. The formalism developed in this work identifies the basic ingredients needed to generate interesting flux patterns and band structures using resonant modulations. Additionally, our approach allows for a simple description of the micro-motion underlying the dynamics; we illustrate its characteristics based on diverse dynamic-lattice configurations. It is shown that the impact of the micro-motion on physical observables strongly depends on the implemented scheme, suggesting that a theoretical description in terms of the effective Hamiltonian alone is generally not sufficient to capture the full time-evolution of the system.
Periodic-Orbit Theory of Level Correlations
Stefan Heusler; Sebastian Müller; Alexander Altland; Petr Braun; Fritz Haake
2006-10-20T23:59:59.000Z
We present a semiclassical explanation of the so-called Bohigas-Giannoni-Schmit conjecture which asserts universality of spectral fluctuations in chaotic dynamics. We work with a generating function whose semiclassical limit is determined by quadruplets of sets of periodic orbits. The asymptotic expansions of both the non-oscillatory and the oscillatory part of the universal spectral correlator are obtained. Borel summation of the series reproduces the exact correlator of random-matrix theory.
Policy Flash 2013-41 Contracts Periods of Performance Exceeding...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
41 Contracts Periods of Performance Exceeding 5 Years Policy Flash 2013-41 Contracts Periods of Performance Exceeding 5 Years Attached is Policy Flash 2013-41 Contracts Periods of...
SEXUAL SIGNALING IN PERIODICAL CICADAS, MAGICICADA SPP. (HEMIPTERA: CICADIDAE)
Simon, Chris
SEXUAL SIGNALING IN PERIODICAL CICADAS, MAGICICADA SPP. (HEMIPTERA: CICADIDAE) by JOHN R. COOLEY1 behavior of periodical cicadas (Insecta: Hemiptera: Magicicada spp.) has been considered enigmatic because
Comparison of quantization of charge transport in periodic and open pumps
Gian Michele Graf; Gregorio Ortelli
2007-09-19T23:59:59.000Z
We compare the charges transported in two systems, a spatially periodic and an open quantum pump, both depending periodically and adiabatically on time. The charge transported in a cycle was computed by Thouless, respectively by Buttiker et al. in the two cases. We show that the results agree in the limit where the two physical situations become the same, i.e., that of a large open pump.
An improved correlation method for determining the period of a torsion pendulum
Luo Jie; Wang Dianhong [Faculty of Mechanical and Electronic Information, China University of Geosciences, Wuhan 430074 (China)
2008-09-15T23:59:59.000Z
Considering variation of environment temperature and unhomogeneity of background gravitational field, an improved correlation method was proposed to determine the variational period of a torsion pendulum with high precision. The result of processing experimental data shows that the uncertainty of determining the period with this method has been improved about twofolds than traditional correlation method, which is significant for the determination of gravitational constant with time-of-swing method.
Diaz, H.F. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Environmental Research Labs.; Hughes, M.K. [Arizona Univ., Tucson, AZ (United States). Lab. of Tree-Ring Research
1992-12-31T23:59:59.000Z
The workshop will focus on climatic variations during the Medieval Warm Period or Little Climatic Optimum. The nominal time interval assigned to this period is AD 900--1300, but climate information available during the century or two preceding and following this episode is welcome. The aims of the workshop will be to: examine the available evidence for the existence of this episode; assess the spatial and temporal synchronicity of the climatic signals; discuss possible forcing mechanisms; and identify areas and paleoenvironmental records where additional research efforts are needed to improve our knowledge of this period. This document consists of abstracts of eighteen papers presented at the meeting.
A Time Model for Distributed Multimedia Applications
KĂĽhnhauser, Winfried
properties, using time to specify synchroneity, periodicity, ordering and timeliness. Last but not least objects arriving too late may become useless. Here, time is used to synchronize stream processing, encompassing for example HDTV video streams with a bit rate of up to 2.8 GBit/sec. Media streams have real-time
IUPAC Periodic Table of Isotopes for the Educational Community
Holden N. E.; Holden,N.E.; Coplen,T.B.
2012-07-15T23:59:59.000Z
John Dalton first proposed the concept of atomic weights of the elements in the first decade of the nineteenth century. These atomic weights of the chemical elements were thought of as constants of nature, similar to the speed of light. Dmitri Mendeleev arranged the atomic weights of the elements in ascending order of value and used the systematic variation of their chemical properties to produce his Periodic Table of the Elements in 1869. Measurement of atomic weight values became an important chemical activity for a century and a half. Theodore Richards received a Noble Prize for his work in this area. In 1913, Fredrick Soddy found a species of radium, which had an atomic weight value of 228, compared to the familiar radium gas value of 226. Soddy coined the term 'isotope' (Greek for 'in the same place') to account for this second atomic weight value in the radium position of the Periodic Table. Both of these isotopes of radium are radioactive. Radioactive isotopes are energetically unstable and will decay (disintegrate) over time. The time it takes for one half of a sample of a given radioactive isotope to decay is the half-life of that isotope. In addition to having different atomic weight values, radium-226 and radium-228 also have different half-life values. Around the same time as Soddy's work, J.J. Thomson (discoverer of the electron) identified two stable (non-radioactive) isotopes of the same element, neon. Over the next 40 years, the majority of the known chemical elements were found to have two or more stable (or long-lived radioactive isotopes that contribute significantly to the determination of the atomic weights of the elements).
Down-hole periodic seismic generator
Hardee, H.C.; Hills, R.G.; Striker, R.P.
1982-10-28T23:59:59.000Z
A down hole periodic seismic generator system is disclosed for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.
Almost Periodic Measures and Meyer Sets
Nicolae Strungaru
2015-01-05T23:59:59.000Z
In the first part, we construct a cut and project scheme from a family $\\{P_\\varepsilon\\}$ of sets verifying four conditions. We use this construction to characterize weighted Dirac combs defined by cut and project schemes and by continuous functions on the internal groups in terms of almost periodicity. We are also able to characterise those weighted Dirac combs for which the internal function is compactly supported. Lastly, using the same cut and project construction for $\\varepsilon$-dual sets, we are able to characterise Meyer sets in $\\sigma$-compact locally compact Abelian groups.
Fukuyama, T.; Shirahama, H. [Faculty of Education, Ehime University, Bunkyo-cho 3, Matsuyama, Ehime 790-8577 (Japan); Watanabe, Y.; Kawai, Y. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasugakoen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Taniguchi, K. [Department of Physics, Kyoto University of Education, Fujinomori-cho 1, Fukakusa, Fushimi-ku, Kyoto 612-8522 (Japan)
2006-07-15T23:59:59.000Z
Time-delayed feedback is applied to the motions associated with the nonlinear periodic regime generated due to current-driven ion acoustic instability; this is a typical instability in a laboratory plasma, and the dynamical behavior is experimentally investigated using delayed feedback. A time-delayed autosynchronization method is applied. When delayed feedback is applied to the nonlinear periodic orbit, the periodic state changes to various motions depending on the control parameters, namely, the arbitrary time delay and the proportionality constant. Lyapunov exponents are calculated in order to examine the dynamical behavior.
Periodic Cluster Mutations and Related Integrable Maps
Allan P Fordy
2014-03-31T23:59:59.000Z
One of the remarkable properties of cluster algebras is that any cluster, obtained from a sequence of mutations from an initial cluster, can be written as a Laurent polynomial in the initial cluster (known as the "Laurent phenomenon"). There are many nonlinear recurrences which exhibit the Laurent phenomenon and thus unexpectedly generate integer sequences. The mutation of a typical quiver will not generate a recurrence, but rather an erratic sequence of exchange relations. How do we "design" a quiver which gives rise to a given recurrence? A key role is played by the concept of "periodic cluster mutation", introduced in 2009. Each recurrence corresponds to a finite dimensional map. In the context of cluster mutations, these are called "cluster maps". What properties do cluster maps have? Are they integrable in some standard sense? In this review I describe how integrable maps arise in the context of cluster mutations. I first explain the concept of "periodic cluster mutation", giving some classification results. I then give a review of what is meant by an integrable map and apply this to cluster maps. Two classes of integrable maps are related to interesting monodromy problems, which generate interesting Poisson algebras of functions, used to prove complete integrability and a linearisation. A connections to the Hirota-Miwa equation is explained.
de Aguiar, M.A.M.; Malta, C.P.; Baranger, M.; Davies, K.T.R.
1987-12-01T23:59:59.000Z
Numerical and analytical studies of the types of period n-upling bifurcations undergone by classical periodic trajectories of non-integrable Hamiltonians with two degrees of freedom are made. The Hamiltonians studied possess time reversal and reflection symmetries and we found that these symmetries give rise to additional types of period n-upling bifurcations. The analytical study explains most of the numerically observed birfucations. copyright 1987 Academic Press, Inc.
Xifeng Su; Lei Zhang; Rafael de la Llave
2015-03-11T23:59:59.000Z
We consider 1-D quasi-periodic Frenkel-Kontorova models (describing, for example, deposition of materials in a quasi-periodic substratum). We study the existence of equilibria whose frequency (i.e. the inverse of the density of deposited material) is resonant with the frequencies of the substratum. We study perturbation theory for small potential. We show that there are perturbative expansions to all orders for the quasi-periodic equilibria with resonant frequencies. Under very general conditions, we show that there are at least two such perturbative expansions for equilibria for small values of the parameter. We also develop a dynamical interpretation of the equilibria in these quasi-periodic media. We show that the dynamical system has very unusual properties. Using these, we obtain results on the Lyapunov exponents of the resonant quasi-periodic solutions. In a companion paper, we develop a rather unusual KAM theory (requiring new considerations) which establishes that the perturbative expansions converge when the perturbing potentials satisfy a one-dimensional constraint.
Quantization and 2{pi} periodicity of the axion action in topological insulators
Vazifeh, M. M.; Franz, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada)
2010-12-15T23:59:59.000Z
The Lagrangian describing the bulk electromagnetic response of a three-dimensional strong topological insulator contains a topological ''axion'' term of the form {theta}E{center_dot}B. It is often stated (without proof) that the corresponding action is quantized on periodic space time and therefore invariant under {theta}{yields}{theta}+2{pi}. Here we provide a simple, physically motivated proof of the axion action quantization on the periodic space time, assuming only that the vector potential is consistent with single valuedness of the electron wave functions in the underlying insulator.
Paris-Sud XI, UniversitĂ© de
A periodic inspection and replacement policy for systems subject to competing failure modes due-making. A condition-based periodic inspection/replacement policy is developed and compared with a benchmark time- based block replacement policy. Numerical results show that it is indeed useful to follow closely
Mago, Alonso Luis
2006-08-16T23:59:59.000Z
not be less than the injection period. On the other hand, the soaking period should be as short as possible because it is unproductive time in terms of field oil production for the well and therefore it translates into a negative cash flow for a company....
Marques, Francisco
period T , St = h2 /T . The two-dimensional time-periodic basic state consists of the boundary layer at x= ± /2; b oscillatory glass floor; c end walls at z= ± /2; d floor of the acrylic con- tainer; e dynamic seals; f free-surface groove and solid wall position at y=h; g Teflon slide pads for oscillatory
ern Ocean was much more vigorous in the period from 1350 to 1880 A.D. than in the
Zhou, Chongwu
. Oceanogr. 14, 666 (1984). 19. Evidence of deep penetration of CFCs in the Southern Ocean [A. H. Orsi, G. Cern Ocean was much more vigorous in the period from 1350 to 1880 A.D. than in the recent past. Our of a subordinate role for deep convection in the Southern Ocean during this time period (21). Our conclusion
Quasi-Periodic Oscillations from Magnetorotational Turbulence
Phil Arras; Omer Blaes; Neal J. Turner
2006-02-13T23:59:59.000Z
Quasi-periodic oscillations (QPOs) in the X-ray lightcurves of accreting neutron star and black hole binaries have been widely interpreted as being due to standing wave modes in accretion disks. These disks are thought to be highly turbulent due to the magnetorotational instability (MRI). We study wave excitation by MRI turbulence in the shearing box geometry. We demonstrate that axisymmetric sound waves and radial epicyclic motions driven by MRI turbulence give rise to narrow, distinct peaks in the temporal power spectrum. Inertial waves, on the other hand, do not give rise to distinct peaks which rise significantly above the continuum noise spectrum set by MRI turbulence, even when the fluid motions are projected onto the eigenfunctions of the modes. This is a serious problem for QPO models based on inertial waves.
Imtak Jeon; Neil Lambert; Paul Richmond
2012-11-29T23:59:59.000Z
We consider periodic arrays of M2-branes in the ABJM model in the spirit of a circle compactification to D2-branes in type IIA string theory. The result is a curious formulation of three-dimensional maximally supersymmetric Yang-Mills theory in terms of fermions, seven transverse scalars, a non-dynamical gauge field and an additional scalar `dual gluon'. Upon further T-duality on a transverse torus we obtain a non-manifest-Lorentz-invariant description of five-dimensional maximally supersymmetric Yang-Mills. Here the additional scalar field can be thought of as the components of a two-form along the torus. This action can be viewed as an M-theory description of M5-branes on ${\\mathbb T}^3$.
Fluorescence in nonlocal dissipative periodic structures
Francesco Intravaia; Kurt Busch
2015-02-24T23:59:59.000Z
We present an approach for the description of fluorescence from optically active material embedded in layered periodic structures. Based on an exact electromagnetic Green's tensor analysis, we determine the radiative properties of emitters such as the local photonic density of states, Lamb shifts, line widths etc. for a finite or infinite sequence of thin alternating plasmonic and dielectric layers. In the effective medium limit, these systems may exhibit hyperbolic dispersion relations so that the large wave-vector characteristics of all constituents and processes become relevant. These include the finite thickness of the layers, the nonlocal properties of the constituent metals, and local-field corrections associated with an emitter's dielectric environment. In particular, we show that the corresponding effects are non-additive and lead to considerable modifications of an emitter's luminescence properties.
Steady periodic gravity waves with surface tension
Samuel Walsh
2009-11-06T23:59:59.000Z
In this paper we consider two-dimensional, stratified, steady water waves propagating over an impermeable flat bed and with a free surface. The motion is assumed to be driven by capillarity (that is, surface tension) on the surface and a gravitational force acting on the body of the fluid. We prove the existence of global continua of classical solutions that are periodic and traveling. This is accomplished by first constructing a 1-parameter family of laminar flow solutions, $\\mathcal{T}$, then applying bifurcation theory methods to obtain local curves of small amplitude solutions branching from $\\mathcal{T}$ at an eigenvalue of the linearized problem. Each solution curve is then continued globally by means of a degree theoretic theorem in the spirit of Rabinowitz. Finally, we complement the degree theoretic picture by proving an alternate global bifurcation theorem via the analytic continuation method of Dancer.
Magnetic helicity evolution in a periodic domain with imposed field
Axel Brandenburg; William H. Matthaeus
2004-05-24T23:59:59.000Z
In helical hydromagnetic turbulence with an imposed magnetic field (which is constant in space and time) the magnetic helicity of the field within a periodic domain is no longer an invariant of the ideal equations. Alternatively, there is a generalized magnetic helicity that is an invariant of the ideal equations. It is shown that this quantity is not gauge invariant and that it can therefore not be used in practice. Instead, the evolution equation of the magnetic helicity of the field describing the deviation from the imposed field is shown to be a useful tool. It is demonstrated that this tool can determine steady state quenching of the alpha-effect. A simple three-scale model is derived to describe the evolution of the magnetic helicity and to predict its sign as a function of the imposed field strength. The results of the model agree favorably with simulations.
Ratchet transport and periodic structures in parameter space
Alan Celestino; Cesar Manchein; Holokx A. Albuquerque; Marcus W. Beims
2011-11-06T23:59:59.000Z
Ratchet models are prominent candidates to describe the transport phenomenum in nature in the absence of external bias. This work analyzes the parameter space of a discrete ratchet model and gives direct connections between chaotic domains and a family of isoperiodic stable structures with the ratchet current. The isoperiodic structures appear along preferred direction in the parameter space giving a guide to follow the current, which usually increases inside the structures but is independent of the corresponding period. One of such structures has the shrimp-shaped form which is known to be an universal structure in the parameter space of dissipative systems. Currents in parameter space provide a direct measure of the momentum asymmetry of the multistable and chaotic attractors times the size of the corresponding basin of attraction. Transport structures are shown to exist in the parameter space of the Langevin equation with an external oscillating force.
Ergodic theory and visualization. II. Harmonic mesochronic plots visualize (quasi)periodic sets
Zoran Levnaji?; Igor Mezi?
2014-07-26T23:59:59.000Z
We present a new method of analysis of measure-preserving dynamical systems, based on frequency analysis and ergodic theory, which extends our earlier work [1]. Our method employs the novel concept of harmonic time average [2], and is realized as a computational algorithms for visualization of periodic and quasi-periodic sets or arbitrary periodicity in the phase space. Besides identifying all periodic sets, our method is useful in detecting chaotic phase space regions with a good precision. The range of method's applicability is illustrated using well-known Chirikov standard map, while its full potential is presented by studying higher-dimensional measure-preserving systems, in particular Froeschl\\'e map and extended standard map.
Extracting unstable periodic orbits from chaotic time series data Paul So,1,2
Roberts, Stephen
, D.C. 20010 2 Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 3
Collins, Kimberlee C. (Kimberlee Chiyoko)
2015-01-01T23:59:59.000Z
Studies of non-diffusive heat conduction provide insight into the fundamentals of heat transport in condensed matter. The mean free paths (MFPs) of phonons that are most important for conducting heat are well represented ...
Timing the Kilohertz Quasi-Periodic Oscillations in Low-mass X-ray Binaries
Mariano Mendez
2000-06-19T23:59:59.000Z
I describe a new technique that we have been using in the past few years to get precise measurements of the frequency separation of the kHz QPOs in some Low-mass X-ray binaries. I show how this technique (that we call "shift-and-add") works, and I present some of the results we obtained using it.
On the Trajectories and Coordination of Steered Particles with Time-Periodic Speed Profiles
Leonard, Naomi
of collective motion and coordinated control to model individual agents as steered particles in the plane contains no frequency content at the turning rate. Steering and speed control laws are derived and analysis of coordinating control laws. This model has been readily adopted in practice because it can
Time series study of urban rainfall suppression during clean-up periods
Geng, Jun
2008-10-10T23:59:59.000Z
. Effects of Pollutant Aerosols on Precipitation……………….... 3 3. Our Focus………………………………………………………. 6 II STUDY OF SUPPRESSION OF PRECIPITATION IN AIR POLLUTIONS BY ANALYZING DATA FROM...)......................................................................................... 21 6 Trends of ratio of annual precipitation amount of Culver City (CC) and Pasadena (PA)...................................................................................... 23 7 The relationship between precipitation and TSP...
Time series study of urban rainfall suppression during clean-up periods
Geng, Jun
2009-05-15T23:59:59.000Z
. Effects of Pollutant Aerosols on Precipitation??????.... 3 3. Our Focus?????????????????????. 6 II STUDY OF SUPPRESSION OF PRECIPITATION IN AIR POLLUTIONS BY ANALYZING DATA FROM...)......................................................................................... 21 6 Trends of ratio of annual precipitation amount of Culver City (CC) and Pasadena (PA)...................................................................................... 23 7 The relationship between precipitation and TSP...
Detrended cross-correlation analysis for non-stationary time series with periodic trends
Podobnik, Boris
Compilation Index Visit the EPL website to read the latest articles published in cutting-edge fields all final acceptance decisions 1 Impact Factor The 2009 Impact Factor increased by 31% to 2
Time series study of urban rainfall suppression during clean-up periods
Geng, Jun
2009-05-15T23:59:59.000Z
. Effects of Pollutant Aerosols on Precipitation??????.... 3 3. Our Focus?????????????????????. 6 II STUDY OF SUPPRESSION OF PRECIPITATION IN AIR POLLUTIONS BY ANALYZING DATA FROM...)......................................................................................... 21 6 Trends of ratio of annual precipitation amount of Culver City (CC) and Pasadena (PA)...................................................................................... 23 7 The relationship between precipitation and TSP...
Time series study of urban rainfall suppression during clean-up periods
Geng, Jun
2008-10-10T23:59:59.000Z
. Effects of Pollutant Aerosols on Precipitation……………….... 3 3. Our Focus………………………………………………………. 6 II STUDY OF SUPPRESSION OF PRECIPITATION IN AIR POLLUTIONS BY ANALYZING DATA FROM...)......................................................................................... 21 6 Trends of ratio of annual precipitation amount of Culver City (CC) and Pasadena (PA)...................................................................................... 23 7 The relationship between precipitation and TSP...
1 DOT Products DOT time period resolution reference type in short
Griesel, Alexa
. Bettadpur, D. P. Chambers, M. Cheng, F. Condi, B. Gunter, Z. Kang, P. Nagel, R. Pastor, T. Pekker, S. Poole
Systems for optimizing the condition of beef carcasses for distribution over extended time periods
Simmons, Ronald Douglas
1974-01-01T23:59:59.000Z
and drying with paper towels, Decontamination by use of chlorine is already in use in the industry (National Provisioner, 1973). It appears that a combination of chlorine treatments and modified atmospheres may prove beneficial for prolonged meat storage... interval and atmosphere x storage interval interactions were significant (P&. 01) . f Rinsed with 200 ppm chlorine. Visual microbial damage scores ranged from 7 (dry, no slime formation) to 1 (wet, moist or dry, extensive colony formation or mold...
Optimal adaptive routing and traffic assignment in stochastic time-dependent networks
Gao, Song, 1976-
2005-01-01T23:59:59.000Z
A stochastic time-dependent (STD) network is defined by treating all link travel times at all time periods as random variables, with possible time-wise and link-wise stochastic dependency. A routing policy is a decision ...
Tonn, Bruce Edward [ORNL; Rose, Erin M [ORNL; Schmoyer, Richard L [ORNL; Eisenberg, Joel Fred [ORNL; Ternes, Mark P [ORNL; Schweitzer, Martin [ORNL; Hendrick, Timothy P [ORNL
2012-08-01T23:59:59.000Z
This report describes the third major evaluation of the Program, encompassing program years 2009 to 2011. In this report, this period of time is referred to as the ARRA Period. This is a special period of time for the Program because the American Recovery and Reinvestment Act (ARRA) of 2009 has allocated $5 billion of funding for the Program. In normal program years, WAP s annual appropriation is in the range of $200-250 million, supporting the weatherization of approximately 100,000 homes. With the addition of ARRA funding during these program years, the expectation is that weatherization activity will exceed 300,000 homes per year. In addition to saving energy and reducing low-income energy bills, expanded WAP funding is expected to stimulate the economy by providing new jobs in the weatherization field and allowing low-income households to spend more money on goods and services by spending less on energy.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesis ofwas publishedThree scientistsDepartmentTime Off
All-sky search for periodic gravitational waves in the full S5 LIGO data
Barsotti, Lisa
We report on an all-sky search for periodic gravitational waves in the frequency band 50–800 Hz and with the frequency time derivative in the range of 0 through -6×10[superscript -9]??Hz/s. Such a signal could be produced ...
Jonckheere, Thibaut
Chaotic Hamiltonian ratchets for pulsed periodic double-well potentials: Classical correlations and the ratchet current N. A. C. Hutchings,1 M. R. Isherwood,1 T. Jonckheere,2 and T. S. Monteiro1 1 Department, ratchet currents, and time scales of a new ratchet in a fully chaotic Hamiltonian system, introduced
SINE WAVE CANCELATION THROUGH A PERIODIC TRANSFER FUNCTION Pierre Granjon, Christine Servire
Paris-Sud XI, Université de
. Moreover, the transfer function of this process can be shown periodic, and therefore time-varying. Thus we, a stator coil is supplied with a current i(t). It generates an additional vibration signal v(t), which the error e(t). It is measured with an accelerometer on the stator frame. i(t) m(t) d(t) v
Small angle neutron scattering on periodically deformed polymers A. R. Rennie
Boyer, Edmond
765 Small angle neutron scattering on periodically deformed polymers A. R. Rennie Institut für Phys-768 SEPTEMBRE 1984, 1. Introduction. Neutron scattering has proved a useful tool for the investigation of a wide time for a small angle neutron scattering spectrum is several minutes. Obser- vation on rapidly
The relationship of physical training and time components of the left ventricle
Bradley, Patrick Walton
1976-01-01T23:59:59.000Z
, and post-exercise values. The selected cardiac-cycle time components included. pre-ejection period (PEP); electromechanical lag (EML); isovolumetric contraction period (ICP); left ventricular ejection time (LVET); mechanical systole (MS); total systole... cardiac-cycle time components. 3. Highly physical trained individuals have significantly increased resting and post-exercise pre-ejection periods, significantly increased resting electromechanical lag and isovolumetric contraction periods...
CEQ Extends Comment Period on Revised Draft Guidance on Consideration...
Broader source: Energy.gov (indexed) [DOE]
comment period on its revised draft guidance on consideration of greenhouse gas (GHG) emissions and the effects of climate change in NEPA reviews. The comment period now ends on...
Transition Period High Water Marks - May 2009.indd
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
the Contract High Water Mark (CHWM) contracts in May 2009, BPA is publishing initial Transition Period High Water Marks (THWMs) and Above-Rate-Period High Water Mark (Above-RHWM)...
Orbital stability of periodic waves for the nonlinear Schrodinger equation
Gallay, Thierry
Orbital stability of periodic waves for the nonlinear SchrË?odinger equation Thierry Gallay Institut: Thierry Gallay, Thierry.Gallay@ujfÂgrenoble.fr Keywords: Nonlinear SchrË?odinger equation, periodic waves
Orbital stability of periodic waves for the nonlinear Schrodinger equation
Orbital stability of periodic waves for the nonlinear SchrÂ¨odinger equation Thierry Gallay Institut: Thierry Gallay, Thierry.Gallay@ujf-grenoble.fr Keywords: Nonlinear SchrÂ¨odinger equation, periodic waves
Orbital stability of periodic waves for the nonlinear Schrodinger equation
Boyer, Edmond
Orbital stability of periodic waves for the nonlinear Schr¨odinger equation Thierry Gallay Institut: Thierry Gallay, Thierry.Gallay@ujf-grenoble.fr Keywords: Nonlinear Schr¨odinger equation, periodic waves
Count-doubling time safety circuit
Rusch, Gordon K. (Downers Grove, IL); Keefe, Donald J. (Lemont, IL); McDowell, William P. (Downers Grove, IL)
1981-01-01T23:59:59.000Z
There is provided a nuclear reactor count-factor-increase time monitoring circuit which includes a pulse-type neutron detector, and means for counting the number of detected pulses during specific time periods. Counts are compared and the comparison is utilized to develop a reactor scram signal, if necessary.
Focusing-to-defocusing crossover in nonlinear periodic structures
Focusing-to-defocusing crossover in nonlinear periodic structures Francis H. Bennet,* InĂ©s A. Amuli
Quarterly Construction Status Report Period Ending: June 30, 2013
Alpay, S. Pamir
Quarterly Construction Status Report Period Ending: June 30, 2013 Storrs and Regional Campuses University of Connecticut Health Center Quarterly Construction Status Report for Period Ending: June 30, 2013 #12;Quarterly Construction Status Report Period Ending: June 30, 2013 Project Number Project Index
Steady periodic waves bifurcating for fixed-depth rotational flows
consider steady periodic water waves for rotational flows with a specified fixed-depth over a flat bed. We the existence of steady periodic water waves for rotational flows with a specified fixed depth over a flat bedSteady periodic waves bifurcating for fixed-depth rotational flows David Henry School
Period of K system generator of pseudorandom numbers
Akopov, N Z; Floratos, Emmanuel G; Savvidy, G K
1996-01-01T23:59:59.000Z
We analyze the structure of the periodic trajectories of the matrix generator of pseudorandom numbers which has been proposed earlier. The structure of the periodic trajectories becomes more transparent when the rational sublattice coincides with the Galois field GF[p]. We are able to compute the period of the trajectories as a function of p and the dimension of the matrix d.
Period of K System Generator of Pseudorandom Numbers
N. Z. Akopov; G. G. Athanasiu; E. G. Floratos; G. K. Savvidy
1996-02-09T23:59:59.000Z
We analyze the structure of the periodic trajectories of the matrix generator of pseudorandom numbers which has been proposed earlier. The structure of the periodic trajectories becomes more transparent when the rational sublattice coincides with the Galois field $GF[p]$. We are able to compute the period of the trajectories as a function of $p$ and the dimension of the matrix $d$.
Periodically poled silicon Nick K. Hon,a
Jalali. Bahram
as quasi-phase matching. Periodically poled silicon PePSi adds the periodic poling capability to silicon to be harnessed for devices based on second-order nonlinear effects. As an example of the utility of the PePSi is in effect, periodically poled silicon PePSi , a new technology for efficient second-order nonlinear
Jitter-Approximation Tradeoff for Periodic Scheduling Zvika Brakerski
Patt-Shamir, Boaz
Jitter-Approximation Tradeoff for Periodic Scheduling Zvika Brakerski Dept. of Electrical the average period of a job in the schedule is blown up w.r.t. its requested period, and the jitter ratio with low jitter ratio allow the mobile devices to save power by hav- ing their receivers switched off
Quarterly Construction Status Report Period Ending: March 31, 2014
Alpay, S. Pamir
Quarterly Construction Status Report Period Ending: March 31, 2014 Storrs and Regional Campuses University of Connecticut Health Center Quarterly Construction Status Report for Period Ending: March 31, 2014 #12;Quarterly Construction Status Report Period Ending: March 31, 2014 Project Number Project
Period-luminosity and period-luminosity-colour relations for Mira variables at maximum light
S. M. Kanbur; M. A. Hendry; D. Clarke
1997-04-14T23:59:59.000Z
In this paper we confirm the existence of period-luminosity (PL) and period-luminosity-colour (PLC) relations at maximum light for O and C Mira variables in the LMC. We demonstrate that in the J and H bands the maximum light PL relations have a significantly smaller dispersion than their counterparts at mean light, while the K band and bolometric PL relations have a dispersion comparable to that at mean light. In the J, H and K bands the fitted PL relations for the O Miras are found to have smaller dispersion than those for the C Miras, at both mean and maximum light, while the converse is true for the relations based on bolometric magnitudes. The inclusion of a non-zero log period term is found to be highly significant in all cases except that of the C Miras in the J band, for which the data are found to be consistent with having constant absolute magnitude. This suggests the possibility of employing C Miras as standard candles. We suggest both a theoretical justification for the existence of Mira PL relations at maximum light and a possible explanation of why these relations should have a smaller dispersion than at mean light. The existence of such maximum light relations offers the possibility of extending the range and improving the accuracy of the Mira distance scale to Galactic globular clusters and to other galaxies.
Periodic eigendecomposition and its application to Kuramoto-Sivashinsky system
Xiong Ding; Predrag Cvitanovi?
2014-06-18T23:59:59.000Z
Periodic eigendecomposition algorithm for calculating eigenvectors of a periodic product of a sequence of matrices, an extension of the periodic Schur decomposition, is formulated and compared with the recently proposed covariant vectors algorithms. In contrast to those, periodic eigendecomposition requires no power iteration and is capable of determining not only the real eigenvectors, but also the complex eigenvector pairs. Its effectiveness, and in particular its ability to resolve eigenvalues whose magnitude differs by hundreds of orders, is demonstrated by applying the algorithm to computation of the full linear stability spectrum of periodic solutions of Kuramoto-Sivashinsky system.
Long Term Simulations Of Astrophysical Jets; Energy Structure and Quasi-Periodic Ejection
Ahmed Ibrahim; Kazunari Shibata
2007-04-23T23:59:59.000Z
We have performed self-consistent 2.5-dimensional nonsteady MHD numerical simulations of jet formation as long as possible, including the dynamics of accretion disks. Although the previous nonsteady MHD simulations for astrophysical jets revealed that the characteristics of nonsteady jets are similar to those of steady jets, the calculation time of these simulations is very short compared with the time scale of observed jets. Thus we have investigated long term evolutions of mass accretion rate, mass outflow rate, jet velocity, and various energy flux. We found that the ejection of jet is quasi-periodic. The period of the ejection is related to the time needed for the initial magnetic filed to be twisted to generate toroidal filed. We compare our results with both the steady state theory and previous 2.5-dimensional nonsteady MHD simulations.
The quasi-periodic nature of wall slip for molten plastics in large amplitude oscillatory shear
Adrian, David Warren
1992-01-01T23:59:59.000Z
is not to be confused with a quasi-periodic spectrum like Figure 15 because of its strong continuous component. 0. 01 X 0. 001 0. 0001 0. 2 0. 4 0. 6 f (Hz) Figure 14. Chaotic amplitude spectrum of Duffing's equation. 0. 1 0. 01 X 0. 001 0. 0001 1E-05 0... amplitude spectrum for a viscoelastic melt in LAOS 6. Pipkin diagram, adapted from Dealy and Wissbrun (1990), 14 showing the regimes of oscillatory shear for a viscoelastic melt . . . . 15 7. Time domain plot of the quasi-periodic forced van der Pol...
Complete Chaotic Mixing in an Electro-osmotic Flow by Destabilization of Key Periodic Pathlines
R. Chabreyrie; C. Chandre; P. Singh; N. Aubry
2011-02-07T23:59:59.000Z
The ability to generate complete, or almost complete, chaotic mixing is of great interest in numerous applications, particularly for microfluidics. For this purpose, we propose a strategy that allows us to quickly target the parameter values at which complete mixing occurs. The technique is applied to a time periodic, two-dimensional electro-osmotic flow with spatially and temporally varying Helmoltz-Smoluchowski slip boundary conditions. The strategy consists of following the linear stability of some key periodic pathlines in parameter space (i.e., amplitude and frequency of the forcing), particularly through the bifurcation points at which such pathlines become unstable.
The quasi-periodic nature of wall slip for molten plastics in large amplitude oscillatory shear
Adrian, David Warren
1992-01-01T23:59:59.000Z
is not to be confused with a quasi-periodic spectrum like Figure 15 because of its strong continuous component. 0. 01 X 0. 001 0. 0001 0. 2 0. 4 0. 6 f (Hz) Figure 14. Chaotic amplitude spectrum of Duffing's equation. 0. 1 0. 01 X 0. 001 0. 0001 1E-05 0... amplitude spectrum for a viscoelastic melt in LAOS 6. Pipkin diagram, adapted from Dealy and Wissbrun (1990), 14 showing the regimes of oscillatory shear for a viscoelastic melt . . . . 15 7. Time domain plot of the quasi-periodic forced van der Pol...
SUPPLEMENT Figure 5. Wavelet time series analysis for yearly LBM outbreaks. a) The normalized time-series. b) Temporally-local wavelet power spectrum (dark red indicates the strongest periodicity while white indicates the weakest periodicity). c) Spatiotemporally-global wavelet spectrum. d) Time-series plot
A comparative study of four significance measures for periodicity detection in astronomical surveys
Süveges, Maria; Eyer, Laurent; Cuypers, Jan; Holl, Berry; Lecoeur-Taďbi, Isabelle; Mowlavi, Nami; Nienartowicz, Krzysztof; Blanco, Diego Ordóńez; Rimoldini, Lorenzo; Ruiz, Idoia
2015-01-01T23:59:59.000Z
We study the problem of periodicity detection in massive data sets of photometric or radial velocity time series, as presented by ESA's Gaia mission. Periodicity detection hinges on the estimation of the false alarm probability (FAP) of the extremum of the periodogram of the time series. We consider the problem of its estimation with two main issues in mind. First, for a given number of observations and signal-to-noise ratio, the rate of correct periodicity detections should be constant for all realized cadences of observations regardless of the observational time patterns, in order to avoid sky biases that are difficult to assess. Second, the computational loads should be kept feasible even for millions of time series. Using the Gaia case, we compare the $F^M$ method (Paltani 2004, Schwarzenberg-Czerny 2012), the Baluev method (Baluev 2008) and the GEV method (S\\"uveges 2014), as well as a method for the direct estimation of a threshold. Three methods involve some unknown parameters, which are obtained by fi...
Green's function analysis of periodic structures in computational electromagnetics
Van Orden, Derek
2011-01-01T23:59:59.000Z
the two-dimensional periodic Green's function," IEEE Trans.evaluation of the Green's function for the Helmholtzrepresentations of certain Green's functions," J. Comp.
EIS-0250: Notice of Public Comment Period Extension and Additional...
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Period Extension and Additional Public Meeting Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, NV...
Uranium Leasing Program Draft PEIS Public Comment Period Extended...
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Uranium Leasing Program Draft PEIS Public Comment Period Extended to May 31, 2013 Draft ULPEIS comment extension community notification041813 (3).pdf More Documents & Publications...
Multilevel interference lithography--fabricating sub-wavelength periodic nanostructures
Chang, Chih-Hao, 1980-
2008-01-01T23:59:59.000Z
Periodic nanostructures have many exciting applications, including high-energy spectroscopy, patterned magnetic media, photonic crystals, and templates for self-assembly. Interference lithography (IL) is an attractive ...
CV evolution: AM Her binaries and the period gap
R. F. Webbink; D. T. Wickramasinghe
2002-04-19T23:59:59.000Z
AM Her variables -- synchronised magnetic cataclysmic variables (CVs) -- exhibit a different period distribution from other CVs across the period gap. We show that non-AM Her systems may infiltrate the longer-period end of the period gap if they are metal-deficient, but that the position and width of the gap in orbital period is otherwise insensitive to other binary parameters (excepting the normalisation of the braking rate). In AM Her binaries, magnetic braking is reduced as the wind from the secondary star may be trapped within the magnetosphere of the white dwarf primary. This reduced braking fills the period gap from its short-period end as the dipole magnetic moment of the white dwarf increases. The consistency of these models with the observed distribution of CVs, both AM Her and non-AM Her type, provides compelling evidence supporting magnetic braking as the agent of angular momentum loss among long-period CVs, and its disruption as the explanation of the 2 - 3 hour period gap among nonmagnetic CVs.
Extension of Comment Period on the Draft Integrated, Interagency...
Extension of Comment Period on the Draft Integrated, Interagency Pre-Application (IIP) Process for Electric Transmission Projects Requiring Federal Authorizations Extension of...
Dwarf Nova-like Outburst of Short Period Intermediate Polar HT Camelopardalis
Ryoko Ishioka; Taichi Kato; Makoto Uemura; Gary W. Billings; Koichi Morikawa; Ken'ichi Torii; Kenji Tanabe; Arto Oksanen; Harri Hyvonen; Hitoshi Itoh
2002-06-12T23:59:59.000Z
We report the first time-series observations of the short outburst of the proposed intermediate polar HT Cam (=RX J0757.0+6306). On 2001 December 29, we detected the object was undergoing a bright outburst at the magnitude of $m_{vis}=12.2$. Following this detection, we started international joint observations through VSNET. The light curve showed a gradual decline for the first 0.5 d. Following this short plateau phase, the rate of decline dramatically increased to more than 4 mag d$^{-1}$. Within 1.5 d from the outburst detection, the object almost declined to the quiescent level. During the rapidly declining phase, long-term modulations with a period of 86 min and strong pulses with a period of 8.6 min were observed. We concluded that 86 min and 8.6 min are the orbital period and the spin period of HT Cam, respectively. By the detection of the spin period, we confirmed the IP classification of HT Cam. However, its outburst behavior rather resembles that of dwarf novae. The discrepancy between the declining rates of the total flux and the pulse flux strongly suggests that the disk instabilities were taking place during the outburst.
Discovery of four periodic methanol masers and updated light curve for a further one
Szymczak, M; Bartkiewicz, A
2015-01-01T23:59:59.000Z
We report the discovery of 6.7 GHz methanol maser periodic flares in four massive star forming regions and the updated light curve for the known periodic source G22.357+0.066. The observations were carried out with the Torun 32 m radio telescope between June 2009 and April 2014. Flux density variations with period of 120 to 245 d were detected for some or all spectral features. A variability pattern with a fast rise and relatively slow fall on time-scale of 30-60 d dominated. A reverse pattern was observed for some features of G22.357+0.066, while sinusoidal-like variations were detected in G25.411+0.105. A weak burst lasting ~520 d with the velocity drift of 0.24 km/s/yr occurred in G22.357+0.066. For three sources for which high resolution maps are available, we found that the features with periodic behaviour are separated by more than 500 au from those without any periodicity. This suggests that the maser flares are not triggered by large-scale homogeneous variations in either the background seed photon fl...
SEARCHES FOR PERIODIC NEUTRINO EMISSION FROM BINARY SYSTEMS WITH 22 AND 40 STRINGS OF ICECUBE
Abbasi, R.; Aguilar, J. A.; Andeen, K.; Baker, M. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Abdou, Y. [Department of Physics and Astronomy, University of Gent, B-9000 Gent (Belgium); Abu-Zayyad, T. [Department of Physics, University of Wisconsin, River Falls, WI 54022 (United States); Ackermann, M.; Bazo Alba, J. L. [DESY, D-15735 Zeuthen (Germany); Adams, J. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Ahlers, M. [Department of Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Allen, M. M. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Altmann, D. [III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen (Germany); Auffenberg, J. [Department of Physics, University of Wuppertal, D-42119 Wuppertal (Germany); Bai, X. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Barwick, S. W. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Bay, R. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Beattie, K. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Beatty, J. J. [Department of Physics and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Bechet, S. [Universite Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels (Belgium); Becker, J. K. [Fakultaet fuer Physik and Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Collaboration: IceCube Collaboration; and others
2012-04-01T23:59:59.000Z
In this paper, we present the results of searches for periodic neutrino emission from a catalog of binary systems. Such modulation, observed in the photon flux, would be caused by the geometry of these systems. In the analysis, the period is fixed by these photon observations, while the phase and duration of the neutrino emission are treated as free parameters to be fit with the data. If the emission occurs during {approx}20% or less of the total period, this analysis achieves better sensitivity than a time-integrated analysis. We use the IceCube data taken from 2007 May 31 to 2008 April 5 with its 22 string configuration and from 2008 April 5 to 2009 May 20 with its 40 string configuration. No evidence for neutrino emission is found, with the strongest excess occurring for Cygnus X-3 at 2.1{sigma} significance after accounting for trials. Neutrino flux upper limits for both periodic and time-integrated emission are provided.
Melott, Adrian L. [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Bambach, Richard K. [Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 121, Washington, DC 20013-7012 (United States)
2013-08-10T23:59:59.000Z
A major revision of the geological timescale was published in 2012. We re-examine our past finding of a 27 Myr periodicity in marine extinction rates by re-assigning dates to the extinction data used previously. We find that the spectral power in this period is somewhat increased, and persists at a narrow bandwidth, which supports our previous contention that the Nemesis hypothesis is untenable as an explanation for the periodicity that was first noted by Raup and Sepkoski in the 1980s. We enumerate a number of problems in a recent study comparing extinction rates with time series models.
Entangled three-particle states in magnetic field: Periodic correlations and density matrices
Amitabha Chakrabarti; Anirban Chakraborti
2010-04-28T23:59:59.000Z
We present a novel study of the time evolutions of entangled states of three spin-1/2 particles in the presence of a constant external magnetic field, which causes the individual spins to precess and leads to remarkable periodicities in the correlations and density matrices. The emerging patterns of periodicity are studied explicitly for different entangled states and in detail for a particular initial configuration of the velocities. Contributions to precession of anomalous magnetic moments are analysed and general results are also obtained. We then introduce an electric field orthogonal to the magnetic field, linking to the preceding case via a suitable Lorentz transformation, and obtain the corresponding Wigner rotations of the spin states. Finally, we point out for the first time that the entangled states corresponding to well-known ones in the study of 3-particle entanglements, may be classified systematically using a particular coupling of three angular momenta.
Phase-locked rhythms in periodically stimulated heart cell aggregates
Glass, Leon
Phase-locked rhythms in periodically stimulated heart cell aggregates MICHAEL R. GUEVARA, ALVIN GUEVARA,MICHAEL R., ALVIN SHRIER,ANDLEONGLASS. Phase-locked rhythms in periodically stimulated heart cell, THE SINOATRIAL NODE acts as the pace- maker of the heart. As a result of the orderly spread of excitation
Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities
Harrison; Neil (Santa Fe, NM), Singleton; John (Los Alamos, NM), Migliori; Albert (Santa Fe, NM)
2008-08-05T23:59:59.000Z
A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.
Periodic Solutions of a Nonlinear Evolution Problem from Heterogeneous Catalysis
Bothe, Dieter
Periodic Solutions of a Nonlinear Evolution Problem from Heterogeneous Catalysis Dieter Bothe for heterogeneous catalysis in a stirred multi-phase chemical reactor. Since the appearance of T-periodic feeds for this evolution problem are provided and applied to the class of reaction-diffusion systems mentioned above. AMS
Dual periodicities in the rotational modulation of Saturn narrowband emissions
Gurnett, Donald A.
Dual periodicities in the rotational modulation of Saturn narrowband emissions S.Y. Ye,1 D. A emissions is examined, restricting the spacecraft location to either the northern or the southern hemisphere of Saturn. It is found that in both hemispheres, the modulation period of 5 kHz narrowband emissions has two
Analysis of Periodic GrowthDisturbance Models Timothy C. Reluga
Reluga, Tim
model for a fluctuating population. Changes in the disturbance frequency are shown to generate a period-bubbling bifurcation structure and population dynamics that are most variable at intermediate disturbance frequenciesAnalysis of Periodic GrowthDisturbance Models Timothy C. Reluga treluga
On the Mass-Period Correlation of the Extrasolar Planets
Shay Zucker; Tsevi Mazeh
2002-02-22T23:59:59.000Z
We report on a possible correlation between the masses and periods of the extrasolar planets, manifested as a paucity of massive planets with short orbital periods. Monte-Carlo simulations show the effect is significant, and is not solely due to an observational selection effect. We also show the effect is stronger than the one already implied by published models that assumed independent power-law distributions for the masses and periods of the extrasolar planets. Planets found in binary stellar systems may have an opposite correlation. The difference is highly significant despite the small number of planets in binary systems. We discuss the paucity of short-period massive planets in terms of some theories for the close-in giant planets. Almost all models can account for the deficit of massive planets with short periods, in particular the model that assumes migration driven by a planet-disk interaction, if the planet masses do not scale with their disk masses.
A low-dimensional model system for quasi-periodic plasma perturbations
Constantinescu, D. [Department of Applied Mathematics, University of Craiova, Association Euratom-MECI (Romania); Dumbrajs, O. [Institute of Solid State Physics, University of Latvia, Association Euratom-UL (Latvia); Igochine, V.; Lackner, K.; Meyer-Spasche, R.; Zohm, H. [Max-Planck Institut fuer Plasmaphysik, Association Euratom-IPP (Germany)
2011-06-15T23:59:59.000Z
Larger scale plasma instabilities not leading to an immediate termination of a discharge often result in periodic nonlinear perturbations of the plasma. A minimal possible model is formulated for description of the system with drive and relaxation processes which have different time scales. The model is based on two equations: the first being responsible for the relaxation dynamics and the second for the drive. The model can be generalized to describe the pellet injection.
Worthington, Josiah Wistar
1966-01-01T23:59:59.000Z
of afterripening to chilling requirement of' parent V. SUMMARY AND CONCLUSIONS 20 26 29 LITERATURE CITED APPENDIX 34 Seed hydration as affected by soaking period Seed germination as influenced by seed hydration during afterripening 35 Germination of.... Influence of stratification time on germi- nation of S-37 and Okinawa peach seeds Page 22 LIST OF FIGURES 1. Seed hydration a. influenced by soaking Page 16 2. Afterripening effectiveness as influenced by pre- soaking seeds 17 3. Germination...
Steady-State Electrical Conduction in the Periodic Lorentz Gas
N. I. Chernov; G. L. Eyink; J. L. Lebowitz; Ya. G. Sinai
1993-02-08T23:59:59.000Z
We study nonequilibrium steady states in the Lorentz gas of periodic scatterers when an external field is applied and the particle kinetic energy is held fixed by a ``thermostat'' constructed according to Gauss' principle of least constraint (a model problem previously studied numerically by Moran and Hoover). The resulting dynamics is reversible and deterministic, but does not preserve Liouville measure. For a sufficiently small field, we prove the following results: (1) existence of a unique stationary, ergodic measure obtained by forward evolution of initial absolutely continuous distributions, for which the Pesin entropy formula and Young's expression for the fractal dimension are valid; (2) exact identity of the steady-state thermodyamic entropy production, the asymptotic decay of the Gibbs entropy for the time-evolved distribution, and minus the sum of the Lyapunov exponents; (3) an explicit expression for the full nonlinear current response (Kawasaki formula); and (4) validity of linear response theory and Ohm's transport law, including the Einstein relation between conductivity and diffusion matrices. Results (2) and (4) yield also a direct relation between Lyapunov exponents and zero-field transport (=diffusion) coefficients. Although we restrict ourselves here to dimension $d=2,$ the results carry over to higher dimensions and to some other physical situations: e.g. with additional external magnetic fields. The proofs use a well-developed theory of small perturbations of hyperbolic dynamical systems and the method of Markov sieves, an approximation of Markov partitions. In our context we discuss also the van Kampen objection to linear response theory, which, we point out, overlooks the ``structural stability'' of strongly hyperbolic flows.
Development of Seismic Isolation Systems Using Periodic Materials
Mo, Yi-Lung; Stokoe, Kenneth H.; Perkins, Judy; Tang, Yu
2014-12-10T23:59:59.000Z
Advanced fast nuclear power plants and small modular fast reactors are composed of thin-walled structures such as pipes; as a result, they do not have sufficient inherent strength to resist seismic loads. Seismic isolation, therefore, is an effective solution for mitigating earthquake hazards for these types of structures. Base isolation, on which numerous studies have been conducted, is a well-defined structure protection system against earthquakes. In conventional isolators, such as high-damping rubber bearings, lead-rubber bearings, and friction pendulum bearings, large relative displacements occur between upper structures and foundations. Only isolation in a horizontal direction is provided; these features are not desirable for the piping systems. The concept of periodic materials, based on the theory of solid-state physics, can be applied to earthquake engineering. The periodic material is a material that possesses distinct characteristics that prevent waves with certain frequencies from being transmitted through it; therefore, this material can be used in structural foundations to block unwanted seismic waves with certain frequencies. The frequency band of periodic material that can filter out waves is called the band gap, and the structural foundation made of periodic material is referred to as the periodic foundation. The design of a nuclear power plant, therefore, can be unified around the desirable feature of a periodic foundation, while the continuous maintenance of the structure is not needed. In this research project, three different types of periodic foundations were studied: one-dimensional, two-dimensional, and three-dimensional. The basic theories of periodic foundations are introduced first to find the band gaps; then the finite element methods are used, to perform parametric analysis, and obtain attenuation zones; finally, experimental programs are conducted, and the test data are analyzed to verify the theory. This procedure shows that the periodic foundation is a promising and effective way to mitigate structural damage caused by earthquake excitation.
Occurrence and Stability of Glaciations in Geologic Time
Zhuang, Kelin
2011-10-21T23:59:59.000Z
Earth is characterized by episodes of glaciations and periods of minimal or no ice through geologic time. Using the linear energy balance model (EBM), nonlinear EBM with empirical ice sheet schemes, the general circulation model coupled with an ice...
Energy Efficient Scheduling for Real-Time Systems
Gupta, Nikhil
2012-02-14T23:59:59.000Z
The goal of this dissertation is to extend the state of the art in real-time scheduling algorithms to achieve energy efficiency. Currently, Pfair scheduling is one of the few scheduling frameworks which can optimally schedule a periodic real...
A space-time processing and spectral analysis methodology
Finlay, Christopher
and interpretation of time-longitude plots, frequency-wavenumber power spectra, and of Radon transform methods and very long period field components is described and justified. Finally use of these tools to investigate
Analysis of Wind Power and Load Data at Multiple Time Scales
Coughlin, Katie
2011-01-01T23:59:59.000Z
29 Appendix A. PJM Windat Multiple Time Scales Appendix A. PJM Wind Data The windpower data for the PJM control area cover the period January
ancient glacial periods: Topics by E-print Network
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15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 MECHANISMS OF ABRUPT CLIMATE CHANGE OF THE LAST GLACIAL PERIOD Geosciences Websites Summary: MECHANISMS OF...
Wave propagation in periodic lattices with defects of smaller dimension
A. A. Kutsenko
2013-05-20T23:59:59.000Z
The procedure of evaluating of the spectrum for discrete periodic operators perturbed by operators of smaller dimensions is obtained. This result allows to obtain propagative, guided, localised spectra for different kind of physical operators on graphs with defects.
Period tripling accumulation point for complexified Henon map
O. B. Isaeva; S. P. Kuznetsov
2005-09-06T23:59:59.000Z
Accumulation point of period-tripling bifurcations for complexified Henon map is found. Universal scaling properties of parameter space and Fourier spectrum intrinsic to this critical point is demonstrated.
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information about Weber, Rodney 19 Type II and IV radio bursts in the active period October-November 2003 CERN Preprints Summary: In this report we present the Type II and IV...
Optimization models for improving periodic maintenance schedules by utilizing opportunities
Patriksson, Michael
to this as preventive maintenance activities at an oppor- tunity. The original opportunistic replacement problemOptimization models for improving periodic maintenance schedules by utilizing opportunities Torgny of Technology Abstract We present mathematical models for finding optimal opportunistic maintenance schedules
Fourier Analysis and Autocorrelation Function Applied to Periodical Nanostructures
Rockett, Angus
Fourier Analysis and Autocorrelation Function Applied to Periodical Nanostructures E. Cruz Microscopy (AFM) Image Fast Fourier Transformation Autocorrelation Function(AC) Angular Distribution] Fourier Analysis: analytical and geometrical aspects, Bray William O ed. New York: Marcel Dekker, 1994
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& Wilcox Conversion Services, LLC Contract Number: DE-AC30-11CC40015 Contract Type: Cost Plus Award Fee Fee Available 4,324,912 408,822,369 Contract Period: December 2010 -...
Variable Selection and Inference for Multi-period Forecasting Problems
Pesaran, M Hashem; Pick, Andreas; Timmermann, Allan
Variable Selection and Inference for Multi-period Forecasting Problems? M. Hashem Pesaran Cambridge University and USC Andreas Pick De Nederlandsche Bank and Cambridge University, CIMF Allan Timmermann UC San Diego and CREATES January 26, 2009...
Ultrasonic wave propagation in random and periodic particulate composites
Henderson, Benjamin Kyle
1996-01-01T23:59:59.000Z
ULTRASONIC WAVE PROPAGATION IN RANDOM AND PERIODIC PARTICULATE COMPOSITES A Thesis by BENJAMIN KYLE HENDERSON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfilltnent of the requirements for the degree... of MASTER OF SCIENCE May 1996 Major Subject: Aerospace Engineering ULTRASONIC WAVE PROPAGATION IN RANDOM AND PERIODIC PARTICULATE COMPOSITES A Thesis by BENJAMIN KYLE HENDERSON Submitted to Texas ASM University in partial fulfillment...
Flux avalanches in superconducting films with periodic arrays of holes.
Vlasko-Vlasov, V.; Welp, U.; Metlushko, V.; Crabtree, G. W.; Materials Science Division; Inst. of Solid State Physics RAS
2000-01-01T23:59:59.000Z
The magnetic flux dynamics in Nb films with periodic hole arrays is studied magneto-optically. Flux motion in the shape of microavalanches along {l_brace}100{r_brace} and {l_brace}110{r_brace} directions of the hole lattice is observed. At lower temperatures anisotropic large scale thermo-magnetic avalanches dominate flux entry and exit. At T-T{sub c} critical-state-like field patterns periodically appear at fractions of the matching field.
Periodic equivalence ratio modulation method and apparatus for controlling combustion instability
Richards, George A. (Morgantown, WV); Janus, Michael C. (Baltimore, MD); Griffith, Richard A. (Morgantown, WV)
2000-01-01T23:59:59.000Z
The periodic equivalence ratio modulation (PERM) method and apparatus significantly reduces and/or eliminates unstable conditions within a combustion chamber. The method involves modulating the equivalence ratio for the combustion device, such that the combustion device periodically operates outside of an identified unstable oscillation region. The equivalence ratio is modulated between preselected reference points, according to the shape of the oscillation region and operating parameters of the system. Preferably, the equivalence ratio is modulated from a first stable condition to a second stable condition, and, alternatively, the equivalence ratio is modulated from a stable condition to an unstable condition. The method is further applicable to multi-nozzle combustor designs, whereby individual nozzles are alternately modulated from stable to unstable conditions. Periodic equivalence ratio modulation (PERM) is accomplished by active control involving periodic, low frequency fuel modulation, whereby low frequency fuel pulses are injected into the main fuel delivery. Importantly, the fuel pulses are injected at a rate so as not to affect the desired time-average equivalence ratio for the combustion device.
Is the apparent period-doubling in Blazhko stars actually an illusion?
Bryant, Paul H
2015-01-01T23:59:59.000Z
It is known that the light curves of many Blazhko stars exhibit intervals in which successive pulsation maxima alternate between two levels in a way that is characteristic of period-doubling. In addition, hydrodynamical models of these stars have clearly demonstrated period-doubling bifurcations. As a result, it is now generally accepted that these stars do indeed exhibit period-doubling. Here we present strong evidence that this assumption is incorrect. The alternating peak heights likely result from the presence of one or more near-resonant modes which appear in the stellar spectra and are significantly offset from 3/2 times the fundamental frequency. A previous explanation for the presence of these peaks is shown to be inadequate. The phase-slip of the dominant near-resonant peak in RR Lyr is shown to be fully correlated with the parity of the observed alternations, providing further strong evidence that the process is nonresonant and cannot be characterized as period-doubling. The dominant near-resonant p...
Transiting Planets with LSST II. Period Detection of Planets Orbiting 1 Solar Mass Hosts
Jacklin, Savannah R; Pepper, Joshua; Stassun, Keivan G
2015-01-01T23:59:59.000Z
The Large Synoptic Survey Telescope (LSST) will photometrically monitor ~1 billion stars for ten years. The resulting light curves can be used to detect transiting exoplanets. In particular, as demonstrated by Lund et al. (2015), LSST will probe stellar populations currently undersampled in most exoplanet transit surveys, including out to extragalactic distances. In this paper we test the efficiency of the box-fitting least-squares (BLS) algorithm for accurately recovering the periods of transiting exoplanets using simulated LSST data. We model planets with a range of radii orbiting a solar-mass star at a distance of 7 kpc, with orbital periods ranging from 0.5 to 20 d. We find that typical LSST observations will be able to reliably detect Hot Jupiters with periods shorter than ~3 d. At the same time, we find that the LSST deep drilling cadence is extremely powerful: the BLS algorithm successfully recovers at least 30% of sub-Saturn-size exoplanets with orbital periods as long as 20 d.
Mean ZZ Ceti pulsation period gauges stellar temperature
Anjum S. Mukadam; M. H. Montgomery; A. Kim; D. E. Winget; S. O. Kepler; J. C. Clemens
2006-12-15T23:59:59.000Z
The mean pulsation period of ZZ Ceti stars increases with decreasing effective temperature as we traverse from the blue to the red edge of the instability strip. This well-established correlation between the mean period and spectroscopic temperature suggests that the mean period could be utilized as a tool to measure the relative temperature of the star independent of spectroscopy. Measuring the pulsation periods of a ZZ Ceti star is a simple, model-independent, and straight forward process as opposed to a spectroscopic determination of its temperature. Internal uncertainties in determining the spectroscopic temperature of a ZZ Ceti star are at least 200K, 15% of the 1350K width of the instability strip. The uncertainties in determining the mean period arise mostly from amplitude modulation in the pulsation spectrum and are smaller than 100s for 91% of the ZZ Ceti stars, temperature indicator rather than conventional spectroscopy. Presently we only claim that the relative temperatures of ZZ Ceti stars derived by using the mean pulsation period are certainly as good as and perhaps about 15% better than spectroscopy.
Periodic Oscillations in the Intra-day Optical Light Curves of the Blazar S5 0716+714
Alok C. Gupta; A. K. Srivastava; Paul J. Wiita
2008-08-27T23:59:59.000Z
We present results of a periodicity search of 20 intra-day variable optical light curves of the blazar S5 0716+714, selected from a database of 102 light curves spanning over three years. We use a wavelet analysis technique along with a randomization test and find strong candidates for nearly periodic variations in eight light curves, with probabilities ranging from 95% to >99%. This is the first good evidence for periodic, or more-precisely, quasi-periodic, components in the optical intra-day variable light curves of any blazar. Such periodic flux changes support the idea that some active galactic nuclei variability, even in blazars, is based on accretion disk fluctuations or oscillations. These intra-day variability time scales are used to estimate that the central black hole of the blazar S5 0716+714 has a mass > 2.5 \\times 10^6$ M$_{\\odot}$. As we did not find any correlations between the flux levels and intra-day variability time scales, it appears that more than one emission mechanism is at work in this blazar.
Interband Coherence Induced Correction to Adiabatic Pumping in Periodically Driven Systems
Hailong Wang; Longwen Zhou; Jiangbin Gong
2015-03-03T23:59:59.000Z
Periodic driving can create topological phases of matter absent in static systems. In terms of the displacement of the position expectation value of a time-evolving wavepacket in a closed system, a type of adiabatic dynamics in periodically driven systems is studied for general initial states possessing coherence between different Floquet bands. Under one symmetry assumption, the displacement of the wavepacket center over one adiabatic cycle is found to be comprised by two components independent of the time scale of the adiabatic cycle: a weighted integral of the Berry curvature summed over all Floquet bands, plus an interband coherence induced correction. The found correction is beyond a naive application of the quantum adiabatic theorem but survives in the adiabatic limit due to interband coherence. Our theoretical results are hence of general interest towards an improved understanding of the quantum adiabatic theorem. Our theory is checked using a periodically driven superlattice model with nontrivial topological phases. In addition to probing topological phase transitions, the adiabatic dynamics studied in this work is now also anticipated to be useful in manifesting coherence and decoherence effects in the representation of Floquet bands.
Periodic trajectories for a two-dimensional nonintegrable Hamiltonian
Baranger, M.; Davies, K.T.R.
1987-08-01T23:59:59.000Z
A numerical study is made of the classical periodic trajectories for the two-dimensional nonintegrable Hamiltonian H = 1/2(p/sup 2//sub x/+p/sup 2//sub y/)+(y-1/2x/sup 2/)/sup 2/+0.05 x/sup 2/. In addition to x--y pictures of the trajectories, E--tau (energy--period) plots of the periodic families are presented. Efforts have been ade to include all trajectories with short periods and all simple branchings of these trajectories. The monodromy matrix has been calculated in all cases, and from it the stability properties are derived. The topology of the E--tau plot has been explored, with the following results. One family may have several stable regions. The plot is not completely connected; there are islands. The plot is not a tree; there are cycles. There are isochronous branchings, period-doublings, and period-multiplyings of higher orders, and examples of each of these are presented. There is often more than one branch issuing from a branch point. Some general empirical rules are inferred. In particular, the existence of isochronous branching is seen to be a consequence of the symmetry of the Hamiltonian. All these results agree with the general classification of possible branchings derived in Ref. (10). (M. A. M. de Aguiar, C. P. Malta, M. Baranger, and K. T. R. Davies, in preparation). Finally, some nonperiodic trajectories are calculated to illustrate the fact that stable periodic trajectories lie in ''regular'' regions of phase space, while unstable ones lie in ''chaotic'' regions.
The BVRI Light Curves And Period Analysis Of The Beta Lyrae System XX Leonis
P. Zasche; M. Wolf; P. Svoboda
2007-11-19T23:59:59.000Z
The contact eclipsing binary system XX Leonis (P = 0.97 days, sp A8) has been analysed using the PHOEBE programme, based on the Wilson Devinney code. The BVRI light curves were obtained during spring 2006 using the 20-cm telescope and ST-7 CCD detector. The effective temperature of the primary component determined from the photometric analysis is T=(7889+/-61)K, the inclination of the orbit is i=(89.98+/-2.45)deg and the photometric mass ratio q=(0.41+/-0.01). Also the third body hypothesis was suggested, based on the period analysis using 57 minimum times and resulting the period of the third body p3= (52.96+/-0.01)yr, amplitude A=(0.057+/-0.029)d and eccentricity e=(0.79+/-0.08) which gives the minimum mass m3,min=(3.6+/-0.8)M_sun.
Periodic Optical Outbursts from the Be/Neutron Star Binary AX J0049.4-7323
A. P. Cowley; P. C. Schmidtke
2003-11-17T23:59:59.000Z
The optical light curve of the Be/neutron star binary AX J0049.4-7323 has been investigated using data from the MACHO and OGLE-II projects. This X-ray source, whose neutron star has a very slow rotation rate (P_pulse=755.5 sec), shows optical outbursts every 394 days. The regularity of these outbursts suggests that their recurrence time is the orbital period of the system. During the outbursts the system brightens and becomes slightly redder. A possible interpretation is that a portion of the equatorial disk is excited as the neutron star passes through it during periastron passage. In the intervals between outbursts the light curve shows 11-day quasi-periodic varability which may be associated with the rotation of the Be star's extended disk.
Christian, Eric
ULYSSES DETECTS LONG-SOUGHT WAVE MOTIONS OF THE SUN Periodic oscillations originating from deep within the Sun's interior have been detected for the first time in interplanetary space by the Ulysses mission to the poles of the Sun. The discovery was reported in this week's issue of Nature magazine
Qin, Xiao
Scheduling of Periodic Packets in Energy-Aware Wireless Networks Xiao Qin , Mohammed Alghamdi, Mais. Abstract Existing packets scheduling algorithms designed for energy-efficient wireless networks ignore in wireless networks subject to both timing and energy constraints. We propose a necessary and sufficient
Periodic force induced stabilization or destabilization of the denatured state of a protein
Ghosh, Pulak Kumar; Bag, Bidhan Chandra; 10.1063/1.3635774
2012-01-01T23:59:59.000Z
We have studied the effects of an external sinusoidal force in protein folding kinetics. The externally applied force field acts on the each amino acid residues of polypeptide chains. Our simulation results show that mean protein folding time first increases with driving frequency and then decreases passing through a maximum. With further increase of the driving frequency the mean folding time starts increasing as the noise-induced hoping event (from the denatured state to the native state) begins to experience many oscillations over the mean barrier crossing time period. Thus unlike one-dimensional barrier crossing problems, the external oscillating force field induces both \\emph{stabilization or destabilization of the denatured state} of a protein. We have also studied the parametric dependence of the folding dynamics on temperature, viscosity, non-Markovian character of bath in presence of the external field.
Intermittent and sustained periodic windows in networked chaotic Rössler oscillators
He, Zhiwei; Sun, Yong [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China) [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhan, Meng, E-mail: zhanmeng@wipm.ac.cn [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)] [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)
2013-12-15T23:59:59.000Z
Route to chaos (or periodicity) in dynamical systems is one of fundamental problems. Here, dynamical behaviors of coupled chaotic Rössler oscillators on complex networks are investigated and two different types of periodic windows with the variation of coupling strength are found. Under a moderate coupling, the periodic window is intermittent, and the attractors within the window extremely sensitively depend on the initial conditions, coupling parameter, and topology of the network. Therefore, after adding or removing one edge of network, the periodic attractor can be destroyed and substituted by a chaotic one, or vice versa. In contrast, under an extremely weak coupling, another type of periodic window appears, which insensitively depends on the initial conditions, coupling parameter, and network. It is sustained and unchanged for different types of network structure. It is also found that the phase differences of the oscillators are almost discrete and randomly distributed except that directly linked oscillators more likely have different phases. These dynamical behaviors have also been generally observed in other networked chaotic oscillators.
Counting of Sieber-Richter pairs of periodic orbits
Gutkin, Boris
2011-01-01T23:59:59.000Z
In the framework of the semiclassical approach the universal spectral correlations in the Hamiltonian systems with classical chaotic dynamics can be attributed to the systematic correlations between actions of periodic orbits which (up to the switch in the momentum direction) pass through approximately the same points of the phase space. By considering symbolic dynamics of the system one can introduce a natural ultrametric distance between periodic orbits and organize them into clusters. Each cluster consists of orbits approaching closely each other in the phase space. We study the distribution of cluster sizes for the backer's map in the asymptotic limit of long trajectories. This problem is equivalent to the one of counting degeneracies in the length spectrum of the {\\it de Bruijn} graphs. Based on this fact, we derive the probability $\\P_k$ that $k$ randomly chosen periodic orbits belong to the same cluster. Furthermore, we find asymptotic behaviour of the largest cluster size $|\\Cll_{\\max}|$ and derive th...
Periodic Discrete Energy for Long-Range Potentials
D. P. Hardin; E. B. Saff; Brian Simanek
2014-12-11T23:59:59.000Z
We consider periodic energy problems in Euclidean space with a special emphasis on long-range potentials that cannot be defined through the usual infinite sum. One of our main results builds on more recent developments of Ewald summation to define the periodic energy corresponding to a large class of long-range potentials. Two particularly interesting examples are the logarithmic potential and the Riesz potential when the Riesz parameter is smaller than the dimension of the space. For these examples, we use analytic continuation methods to provide concise formulas for the periodic kernel in terms of the Epstein Hurwitz Zeta function. We apply our energy definition to deduce several properties of the minimal energy including the asymptotic order of growth and the distribution of points in energy minimizing configurations as the number of points becomes large. We conclude with some detailed calculations in the case of one dimension, which shows the utility of this approach.
Double-periodic blue variables in the Magellanic Clouds
R. E. Mennickent; G. Pietrzynski; M. Diaz; W. Gieren
2002-12-09T23:59:59.000Z
We report the discovery, based on an inspection of the OGLE-II database, of a group of blue variables in the Magellanic Clouds showing simultaneously two kinds of photometric variability: a short-term cyclic variability with typical amplitude $\\Delta I \\sim$ 0.05 mag and period $P_{1}$ between 4 and 16 days and a sinusoidal, long-term cyclic oscillation with much larger amplitude $\\Delta I \\sim$ 0.2 mag with period $P_{2}$ in the range of 150-1000 days. We find that both periods seems to be coupled through the relationship $P_{2}$ = 35.2 $\\pm$ 0.8 $P_{1}$. In general, the short term variability is reminiscent of those shown by Algol-type binaries. We propose that the long-term oscillation could arise in the precession of a elliptical disc fed by a Roche-lobe filling companion in a low mass ratio Algol system.
Lyapunov functions for periodic matrix-valued Jacobi operators
Evgeny Korotyaev; Anton Kutsenko
2007-01-16T23:59:59.000Z
We consider periodic matrix-valued Jacobi operators. The spectrum of this operator is absolutely continuous and consists of intervals separated by gaps. We define the Lyapunov function, which is analytic on an associated Riemann surface. On each sheet the Lyapunov function has the standard properties of the Lyapunov function for the scalar case. We show that this function has (real or complex) branch points, which we call resonances. We prove that there exist two types of gaps: i) stable gaps, i.e., the endpoints are periodic and anti-periodic eigenvalues, ii) unstable (resonance) gaps, i.e., the endpoints are resonances (real branch points). We show that some spectral data determine the spectrum (counting multiplicity) of the Jacobi operator.
Period doubling, information entropy, and estimates for Feigenbaum's constants
Reginald D. Smith
2013-08-03T23:59:59.000Z
The relationship between period doubling bifurcations and Feigenbaum's constants has been studied for nearly 40 years and this relationship has helped uncover many fundamental aspects of universal scaling across multiple nonlinear dynamical systems. This paper will combine information entropy with symbolic dynamics to demonstrate how period doubling can be defined using these tools alone. In addition, the technique allows us to uncover some unexpected, simple estimates for Feigenbaum's constants which relate them to log 2 and the golden ratio, phi, as well as to each other.
A wavelet-based tool for studying non-periodicity
R. Benítez; V. J. Bolós; M. E. Ramírez
2010-07-20T23:59:59.000Z
This paper presents a new numerical approach to the study of non-periodicity in signals, which can complement the maximal Lyapunov exponent method for determining chaos transitions of a given dynamical system. The proposed technique is based on the continuous wavelet transform and the wavelet multiresolution analysis. A new parameter, the \\textit{scale index}, is introduced and interpreted as a measure of the degree of the signal's non-periodicity. This methodology is successfully applied to three classical dynamical systems: the Bonhoeffer-van der Pol oscillator, the logistic map, and the Henon map.
Diffraction Properties of Periodic Lattices under Free Electron Laser Radiation
Rajkovic, I.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Quevedo, W. [Max Planck Institute for Biophysical Chemistry, 37070 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max-Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Tolkiehn, M. [Institut fuer Roentgenphysik, Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, 37070 Goettingen (Germany); Max-Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)
2010-03-26T23:59:59.000Z
In this Letter, we report the pioneering use of free electron laser radiation for the investigation of periodic crystalline structures. The diffraction properties of silver behenate single nanocrystals (5.8 nm periodicity) with the dimensions of 20 nmx20 nmx20 {mu}m and as powder with grain sizes smaller than 200 nm were investigated with 8 nm free electron laser radiation in single-shot modus with 30 fs long free electron laser pulses. This work emphasizes the possibility of using soft x-ray free electron laser radiation for these crystallographic studies on a nanometer scale.
Variation of the Light and Period of the Magnetic Cataclysmic Variable Am Her
Belinda Kalomeni; Kadri Yakut
2008-11-04T23:59:59.000Z
Ground-based long-term optic variability of AM Her, covering the period between 2003-2008, has been conducted to study the features seen in both low and high states of the system. Low-state analysis shows the presence of short-term, low-amplitude light variations of about 0.02-0.03 mag with a mean power time between 16 s and 226 s. Brightness variations on the order of 0.7--2 mag, which could be due to the stellar activity of the component in the system, are also detected. A total of 30 years times of minimum light given in the literature are combined with nine times of minima obtained in this study. We represented the (observed--calculated) diagram by a parabolic curve and also by two broken lines. Under the assumption of a parabolic variation, we estimate an increase in period, dP/dt=7.5(1.2)x10^{-9} days yr^{-1}, with a mass transfer rate of dM/dt = 8(2)x10^{-9} M_{\\odot} yr^{-1}, in agreement with the previous findings by a different method.
Victor Teboul; Jean-Baptiste Accary
2014-04-05T23:59:59.000Z
Recent results have shown the appearance of induced cooperative motions called dynamic heterogeneity during the isomerization of diluted azobenzene molecules in a host glass-former. In this paper we raise the issue of the coupling between these "artificial" heterogeneities and the isomerization period. How do these induced heterogeneities differ in the saturation regime and in the linear response regime ? Is there a maximum of the heterogeneous motion versus isomerization rate and why ? Are the heterogeneity evolution with the isomerization rate connected with the diffusion or relaxation time evolution ? We use out of equilibrium molecular dynamics simulations to answer these questions. We find that the heterogeneity increases in the linear response regime for large isomerization periods and small perturbations. In contrast the heterogeneity decreases in the saturation regime, i.e. when the isomerization half-period ($\\tau_{p}/2$) is smaller than the relaxation time of the material ($\\tau_{\\alpha}$). This result makes possible a test of the effect of cooperative motions on the dynamics using the chromophores as Maxwell demons that destroy or stimulate the cooperative motions. Because the heterogeneities increase in the linear regime and then decrease in the saturation regime, we find a maximum for $\\tau_{p}/2 \\approx \\tau_{\\alpha}$. The induced excitations concentration follows a power law evolution versus the isomerization rate and then saturates. As a consequence the $\\alpha$ relaxation time is related to the excitation concentration with a power law, a result in qualitative agreement with recent findings in constrained models. This result supports a common origin for the heterogeneities with constrained models and a similar relation to the excitation concentration.
Femtosecond diffraction dynamics of laser-induced periodic surface structures on fused silica
Hoehm, S.; Rosenfeld, A. [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strasse 2A, D-12489 Berlin (Germany)] [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strasse 2A, D-12489 Berlin (Germany); Krueger, J.; Bonse, J. [BAM Bundesanstalt fuer Materialforschung und - pruefung, Unter den Eichen 87, D-12205 Berlin (Germany)] [BAM Bundesanstalt fuer Materialforschung und - pruefung, Unter den Eichen 87, D-12205 Berlin (Germany)
2013-02-04T23:59:59.000Z
The formation of laser-induced periodic surface structures (LIPSS) on fused silica upon irradiation with linearly polarized fs-laser pulses (50 fs pulse duration, 800 nm center wavelength) is studied experimentally using a transillumination femtosecond time-resolved (0.1 ps-1 ns) pump-probe diffraction approach. This allows to reveal the generation dynamics of near-wavelength-sized LIPSS showing a transient diffraction at specific spatial frequencies even before a corresponding permanent surface relief was observed. The results confirm that the ultrafast energy deposition to the materials surface plays a key role and triggers subsequent physical mechanisms such as carrier scattering into self-trapped excitons.
Overall Dynamic Properties of 3-D periodic elastic composites
Ankit Srivastava; Sia Nemat-Nasser
2011-05-27T23:59:59.000Z
A method for the homogenization of 3-D periodic elastic composites is presented. It allows for the evaluation of the averaged overall frequency dependent dynamic material constitutive tensors relating the averaged dynamic ?eld variable tensors of velocity, strain, stress, and linear momentum. The formulation is based on micromechanical modeling of a representative unit cell of a composite proposed by Nemat-Nasser & Hori (1993), Nemat-Nasser et. al. (1982) and Mura (1987) and is the 3-D generalization of the 1-D elastodynamic homogenization scheme presented by Nemat-Nasser & Srivastava (2011). We show that for 3-D periodic composites the overall compliance (stiffness) tensor is hermitian, irrespective of whether the corresponding unit cell is geometrically or materially symmetric.Overall mass density is shown to be a tensor and, like the overall compliance tensor, always hermitian. The average strain and linear momentum tensors are, however, coupled and the coupling tensors are shown to be each others' hermitian transpose. Finally we present a numerical example of a 3-D periodic composite composed of elastic cubes periodically distributed in an elastic matrix. The presented results corroborate the predictions of the theoretical treatment.
Spectroscopy and orbital periods of four cataclysmic variable stars
J. R. Thorstensen; C. J. Taylor
2001-05-29T23:59:59.000Z
We present spectroscopy and orbital periods Porb of four relatively little-studied cataclysmic variable stars. The stars and their periods are: AF Cam, Porb = 0.324(1) d (the daily cycle count is slightly ambiguous); V2069 Cyg (= RX J2123.7+4217), 0.311683(2) d; PG 0935+075, 0.1868(3) d; and KUV 03580+0614, 0.1495(6) d. V2069 Cyg and KUV 03580+0614 both show HeII lambda 4686 emission comparable in strength to H beta. V2069 Cyg appears to be a luminous novalike variable, and the strong HeII suggests it may be an intermediate polar. The period of KUV 03580+0614 is similar to members of the SW Sex-type novalike variables, and it shows the phase-dependent absorption in the Balmer and He I lines typical of this subclass. AF Cam shows absorption features from a K-type secondary, as expected given its rather long orbital period. The secondary spectrum and the outburst magnitude both suggest that AF Cam is about 1 kpc distant. The spectrum of PG 0935+075 resembles that of a dwarf nova at minimum light, with a noticeable contribution from an M-dwarf secondary star. The secondary spectrum and a tentative outburst magnitude both suggest a distance near 500 pc.
Excitation and control of multi-phase periodic waves in
Fominov, Yakov
the phase of the excited wave by the driver ("phase-locking") control the wave by varying parametersExcitation and control of multi-phase periodic waves in sine-Gordon equation Arkadiy Shagalovµcr U ()eff U ()eff Threshold condition for phase-locking: µ > µcr = 0.41 > cr = 3.28 3/2 0m 3
Collective periodicity in mean-field models of cooperative behavior
Francesca Collet; Paolo Dai Pra; Marco Formentin
2015-02-06T23:59:59.000Z
We propose a way to break symmetry in stochastic dynamics by introducing a dissipation term. We show in a specific mean-field model, that if the reversible model undergoes a phase transition of ferromagnetic type, then its dissipative counterpart exhibits periodic orbits in the thermodynamic limit.
Diffusive propagation of wave packets in a fluctuating periodic potential
Eman Hamza; Yang Kang; Jeffrey Schenker
2010-10-05T23:59:59.000Z
We consider the evolution of a tight binding wave packet propagating in a fluctuating periodic potential. If the fluctuations stem from a stationary Markov process satisfying certain technical criteria, we show that the square amplitude of the wave packet after diffusive rescaling converges to a superposition of solutions of a heat equation.
lthough Earth has undergone many periods of significant environmen-
Horton, Tom
A lthough Earth has undergone many periods of significant environmen- tal change, the planet push the Earth system outside the stable environmental state of the Holocene, with consequences occurred naturally and Earth's regu- latory capacity maintained the conditions that enabled human
On the Survival of Short-Period Terrestrial Planets
Rosemary A. Mardling; D. N. C. Lin
2004-06-30T23:59:59.000Z
The currently feasible method of detection of Earth-mass planets is transit photometry, with detection probability decreasing with a planet's distance from the star. The existence or otherwise of short-period terrestrial planets will tell us much about the planet formation process, and such planets are likely to be detected first if they exist. Tidal forces are intense for short-period planets, and result in decay of the orbit on a timescale which depends on properties of the star as long as the orbit is circular. However, if an eccentric companion planet exists, orbital eccentricity ($e_i$) is induced and the decay timescale depends on properties of the short-period planet, reducing by a factor of order $10^5 e_i^2$ if it is terrestrial. Here we examine the influence companion planets have on the tidal and dynamical evolution of short-period planets with terrestrial structure, and show that the relativistic potential of the star is fundamental to their survival.
NANO EXPRESS Fabrication of Large Area Periodic Nanostructures Using
Mohseni, Hooman
, such as photonic band-gap materials, high dense data storage, and photonic devices. We have developed a maskless areas, such as photonic band-gap materials [1], high dense data storage [2], and photonic devices [3NANO EXPRESS Fabrication of Large Area Periodic Nanostructures Using Nanosphere Photolithography
Colloidal Inks for Directed Assembly of 3-D Periodic Structures
Lewis, Jennifer
during assembly, which simultaneously facilitated bonding and shape retention of the deposited elements the desired 3-D periodicity, places the most stringent demands on ink design. Direct-write techniques- controlled viscoelastic response; that is, they must be able to flow through a deposition nozzle
Model Reduction Near Periodic Orbits of Hybrid Dynamical Systems
Sastry, S. Shankar
manipulation in manufacturing [2], gene regulation in cells [3], and power generation in electrical systems [41 Model Reduction Near Periodic Orbits of Hybrid Dynamical Systems Samuel A. Burden, Shai Revzen system. We demonstrate reduction of a highÂdimensional underactuated mechanical model for terrestrial
Proton aurora related to intervals of pulsations of diminishing periods
California at Berkeley, University of
Proton aurora related to intervals of pulsations of diminishing periods A. G. Yahnin,1 T. A are generated because of a cyclotron instability of the anisotropic distribution of ring current ions. Proton precipitation produced by the cyclotron instability can be responsible for proton aurora. Indeed
Strategic Sourcing Dashboard Reporting Period: January 2010 through December 2011
Minnesota, University of
We have accomplished $10.8 million in annual savings through our Strategic Sourcing efforts over below. Strategic Sourcing continues to have a significant emphasis for Purchasing Services, but savings/Activities/Risks for this Reporting Period Annual savings of over $200,000 was booked in the last quarter in the office and lab supply
Total Estimated Contract Cost: Performance Period Total Fee Paid
Office of Environmental Management (EM)
Fee Paid 127,390,991 Contract Number: Fee Available Contract Period: Contract Type: Cost Plus Award Fee 4,104,318,749 28,500,000 31,597,837 0 39,171,018 32,871,600 EM...
CLATHRATE HYDRATES FORMATION IN SHORT-PERIOD COMETS
Marboeuf, Ulysse; Mousis, Olivier; Petit, Jean-Marc [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, 25010 Besancon Cedex (France); Schmitt, Bernard, E-mail: marboeuf@ujf-grenoble.f [Universite Joseph Fourier, Laboratoire de Planetologie de Grenoble, CNRS INSU (France)
2010-01-01T23:59:59.000Z
The initial composition of current models of cometary nuclei is only based on two forms of ice: crystalline ice for long-period comets and amorphous ice for short-period comets. A third form of ice, i.e., clathrate hydrate, could exist within the short-period cometary nuclei, but the area of formation of this crystalline structure in these objects has never been studied. Here, we show that the thermodynamic conditions in the interior of short-period comets allow the existence of clathrate hydrates in Halley-type comets. We show that their existence is viable in the Jupiter family comets only when the equilibrium pressure of CO clathrate hydrate is at least 1 order of magnitude lower than the usually assumed theoretical value. We calculate that the amount of volatiles that could be trapped in the clathrate hydrate layer may be orders of magnitude greater than the daily amount of gas released at the surface of the nucleus at perihelion. The formation and the destruction of the clathrate hydrate cages could then explain the diversity of composition of volatiles observed in comets, as well as some pre-perihelion outbursts. We finally show that the potential clathrate hydrate layer in comet 67P/Churyumov-Gerasimenko would, unfortunately, be deep inside the nucleus, out of reach of the Rosetta lander. However, such a clathrate hydrate layer would show up by the gas composition of the coma.
Extraordinary infrared transmission through a periodic bowtie aperture array
Xu, Xianfan
Extraordinary infrared transmission through a periodic bowtie aperture array Edward C. Kinzel to surface plasmon polariton (SPP) resonances and/or RayleighWood anomalies (RWA). Bowtie apertures to be strongly resonant. We demonstrate here that the total transmission through a bowtie aperture array can
Periodic fluctuations in deep water formation due to sea ice
Raj Saha
2015-02-21T23:59:59.000Z
During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural periodicity and produces burst patterns very similar to what is observed in temperature proxy data. Numerical experiments with the model also suggests that the characteristic period of 1,500 years is due to the geometry, or the effective heat capacity, of the ocean that comes under sea ice cover.
Some Reflections on the Periodization of Tibetan History
Cuevas, Bryan
2006-01-01T23:59:59.000Z
Some Reflections on the Periodization of Tibetan History* Bryan J. Cuevas(Florida State University, USA) istory is always expressed as a narrative, a story about the past. Towrite a story out of the events of the past, historians must give...
Bounded, Periodic Relative Motion using Canonical Epicyclic Orbital Elements
Rowley, Clarence W.
Bounded, Periodic Relative Motion using Canonical Epicyclic Orbital Elements N. Jeremy Kasdin using canonical perturbation theory for studying relative motion trajectories and for finding simple motion [2, 3, 4, 5]. This has the advantage that Lagrange's planetary equations (LPEs) or Gauss
The theme of a vanishing period. Daniel Barlet
Paris-Sud XI, Université de
period, Bernstein polynomial, filtered Gauss-Manin sys- tem, (a,b)-module, Brieskorn module. Contents 1.1 Stability by quotient and twisted duality. . . . . . . . . . . . . . . . . 10 3.2 Standard and canonical forms for a []-primitive theme. . . . . . . . 18 4 The uniqueness of a canonical form 23 4
First passage time statistics of Brownian motion with purely time dependent drift and diffusion
Molini, Annalisa; Katul, Gabriel G; Porporato, Amilcare
2010-01-01T23:59:59.000Z
Systems where resource availability approaches a critical threshold are common to many engineering and scientific applications and often necessitate the estimation of first passage time statistics of a Brownian motion (Bm) driven by time-dependent drift and diffusion coefficients. Modeling such systems requires solving the associated Fokker-Planck equation subject to an absorbing barrier. Conditional probabilities are classically derived via the method of images, whose applicability to time-dependent problems, including stochastic resonance, is discussed. First passage time statistics, such as the survival probabilities and first passage time densities are obtained analytically. The analysis includes the study of different functional forms of the time dependent drift and diffusion, such as power-law time dependence and different periodic drivers. As a case study of these theoretical results, a stochastic model for snow melt in mountain regions is presented where both temperature effects and snow-precipitation...
Bayesian inference for pulsar timing models
Vigeland, Sarah J
2013-01-01T23:59:59.000Z
The extremely regular, periodic radio emission from millisecond pulsars make them useful tools for studying neutron star astrophysics, general relativity, and low-frequency gravitational waves. These studies require that the observed pulse time of arrivals are fit to complicated timing models that describe numerous effects such as the astrometry of the source, the evolution of the pulsar's spin, the presence of a binary companion, and the propagation of the pulses through the interstellar medium. In this paper, we discuss the benefits of using Bayesian inference to obtain these timing solutions. These include the validation of linearized least-squares model fits when they are correct, and the proper characterization of parameter uncertainties when they are not; the incorporation of prior parameter information and of models of correlated noise; and the Bayesian comparison of alternative timing models. We describe our computational setup, which combines the timing models of tempo2 with the nested-sampling integ...
de Ponthiere, Pierre; Fumagalli, F; Hambsch, Franz-Josef; Krajci, Tom; Llapasset, J-M; Menzies, Kenneth; Nobile, Marco; Sabo, Richard
2012-01-01T23:59:59.000Z
We present the results of collaborative observations of three RR Lyrae stars (CX Lyr, NU Aur and VY CrB) which have a strong Blazhko effect. This work has been initiated and performed in the framework of the GEOS RR Lyr Survey (Groupe Europ\\'een d'Observations Stellaires). From the measured light curves, we have determined the times and the magnitudes at maximum. The times of maxima have been compared to ephemerides to obtain the (O-C) values and from a period analysis of these (O-C) values, the Blazhko period is derived. The Blazhko periods of NU Aur (114.8 days) and VY CrB (32.3 days) are reported here for the first time and a more accurate period for CX Lyr (68.3 days) has been obtained. The three stars are subject to strong Blazhko effect, but this effect has different characteristics for each of them. When we compare the variations of magnitude at maximum and variations of (O-C) values with respect to the Blazhko phase, these variations are either in phase, in opposition, or even in quadrature.
Chaotic Dynamics of One-Dimensional Systems with Periodic Boundary Conditions
Pankaj Kumar; Bruce N. Miller
2014-10-01T23:59:59.000Z
We provide appropriate tools for the analysis of dynamics and chaos for one-dimensional systems with periodic boundary conditions. Our approach allows for the investigation of the dependence of the largest Lyapunov exponent on various initial conditions of the system. The method employs an effective approach for defining the phase-space distance appropriate for systems with periodic boundary and allows for an unambiguous test-orbit rescaling in the phase space required to calculate the Lyapunov exponents. We elucidate our technique by applying it to investigate the chaotic dynamics of a one-dimensional plasma with periodic boundary. Exact analytic expressions are derived for the electric field and potential using Ewald sums thereby making it possible to follow the time-evolution of the plasma in simulation without any special treatment of the boundary. By employing a set of event-driven algorithms, we calculate the largest Lyapunov exponent, the radial distribution function and the kinetic pressure by following the evolution of the system in phase space without resorting to numerical manipulation of the equations of motion. Simulation results are presented and analyzed for the one-dimensional plasma with a view to examining the dynamical and chaotic behavior exhibited by small and large versions of the system.
Variable timing circuit for motive power battery chargers
Lambert, F.J.; Bosack, D.J.; Johansen, D.K.
1984-03-27T23:59:59.000Z
A timing circuit for charging motive power batteries. The timing control circuit provides different times of charge in accordance with the time at which a predetermined voltage/current state of the battery is achieved. Control circuit cooperates with a controller in causing termination of the charging operation immediately upon reaching of the voltage/current state if this occurs in a first time slot of an initial control time period. The timing circuit provides an automatic finish time period of charge if the battery reaches the predetermined voltage/current state at some time during the initial control time period. The control includes a switch permitting the user to cause an automatic additional amount of charging upon completion of the normal charging cycle effected by the control, such as for effecting a weekend charge. The control further includes structure for terminating the charging operation in the event the battery being charged does not reach the predetermined voltage/current state at the end of a preselected maximum time. A signal light signals such a fault condition in the charging operation.
Periodic photometric variability of the brown dwarf Kelu-1
F. J. Clarke; C. G. Tinney; K. R. Covey
2002-01-10T23:59:59.000Z
We have detected a strong periodicity of 1.80+/-0.05 hours in photometric observations of the brown dwarf Kelu-1. The peak-to-peak amplitude of the variation is ~1.1% (11.9+/-0.8 mmag) in a 41nm wide filter centred on 857nm and including the dust/temperature sensitive TiO & CrH bands. We have identified two plausible causes of variability: surface features rotating into- and out-of-view and so modulating the light curve at the rotation period; or, elliposidal variability caused by an orbiting companion. In the first scenario, we combine the observed vsin(i) of Kelu-1 and standard model radius to determine that the axis of rotation is inclined at 65+/-12 degrees to the line of sight.
Periodic Schrödinger operators with local defects and spectral pollution
Eric Cancčs; Virginie Ehrlacher; Yvon Maday
2011-11-16T23:59:59.000Z
This article deals with the numerical calculation of eigenvalues of perturbed periodic Schr\\"odinger operators located in spectral gaps. Such operators are encountered in the modeling of the electronic structure of crystals with local defects, and of photonic crystals. The usual finite element Galerkin approximation is known to give rise to spectral pollution. In this article, we give a precise description of the corresponding spurious states. We then prove that the supercell model does not produce spectral pollution. Lastly, we extend results by Lewin and S\\'er\\'e on some no-pollution criteria. In particular, we prove that using approximate spectral projectors enables one to eliminate spectral pollution in a given spectral gap of the reference periodic Sch\\"odinger operator.
Periodic fluctuations in deep water formation due to sea ice
Saha, Raj
2015-01-01T23:59:59.000Z
During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...
GALACTIC COSMIC-RAY ENERGY SPECTRA AND COMPOSITION DURING THE 2009-2010 SOLAR MINIMUM PERIOD
Lave, K. A.; Binns, W. R.; Israel, M. H. [Department of Physics and the McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States); Wiedenbeck, M. E. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Christian, E. R.; De Nolfo, G. A.; Von Rosenvinge, T. T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Cummings, A. C.; Davis, A. J.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C. [California Institute of Technology, Pasadena, CA 91125 (United States)
2013-06-20T23:59:59.000Z
We report new measurements of the elemental energy spectra and composition of galactic cosmic rays during the 2009-2010 solar minimum period using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer. This period of time exhibited record-setting cosmic-ray intensities and very low levels of solar activity. Results are given for particles with nuclear charge 5 {<=} Z {<=} 28 in the energy range {approx}50-550 MeV nucleon{sup -1}. Several recent improvements have been made to the earlier CRIS data analysis, and therefore updates of our previous observations for the 1997-1998 solar minimum and 2001-2003 solar maximum are also given here. For most species, the reported intensities changed by less than {approx}7%, and the relative abundances changed by less than {approx}4%. Compared with the 1997-1998 solar minimum relative abundances, the 2009-2010 abundances differ by less than 2{sigma}, with a trend of fewer secondary species observed in the more recent time period. The new 2009-2010 data are also compared with results of a simple ''leaky-box'' galactic transport model combined with a spherically symmetric solar modulation model. We demonstrate that this model is able to give reasonable fits to the energy spectra and the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe. These results are also shown to be comparable to a GALPROP numerical model that includes the effects of diffusive reacceleration in the interstellar medium.
Wave propagation in periodic networks of thin fibers
S. Molchanov; B. Vainberg
2009-08-02T23:59:59.000Z
We will discuss a one-dimensional approximation for the problem of wave propagation in networks of thin fibers. The main objective here is to describe the boundary (gluing) conditions at branching points of the limiting one-dimensional graph. The results will be applied to Mach-Zehnder interferometers on chips and to periodic chains of the interferometers. The latter allows us to find parameters which guarantee the transparency and slowing down of wave packets.
Spatially Dispersive Inhomogeneous Electromagnetic Media with Periodic Structure
Gratus, Jonathan
2015-01-01T23:59:59.000Z
Spatially dispersive (also known as non-local) electromagnetic media are considered where the parameters defining the permittivity relation vary periodically. Maxwell's equations give rise to a difference equation corresponding to the Floquet modes. A complete set of approximate solutions is calculated which are valid when the inhomogeneity is small. This is applied to inhomogeneous wire media. A new feature arises when considering spatially dispersive media, that is the existence of coupled modes.
A climatological analysis of the freeze period of Texas
Donahue, Christopher Alan
1991-01-01T23:59:59.000Z
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Synoptic Patterns Sample Calculations and Applications CONCLUSIONS AND RECOMMENDATIONS. . . 31 41 45 59 70 76 VI 81 APPENDIX Computer Programs 83 VITA 90 LIST OF TABLES Table Page 1 Periods of record for substations 17 2 Sample of data... of the freeze in parentheses. . . . . . . . . 64 16 Dates of 10% and 90% first and last freeze probabilities 75 tx LIST OF FIGURES Figure Page Map of the study area with the substation locations indicated . 2 Station history for Corsicana, Texas 16...
PARC Periodical: Volume 5, Issue 3 | Photosynthetic Antenna Research Center
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for RenewableSpeedingBiomass and BiofuelsOversightand SimulatedEQUILIBRIUM4,Periodical:
An evolved donor star in the long-period cataclysmic variable HS 0218+3229
Rodríguez-Gil, P; Gänsicke, B T; Muńoz-Darias, T; Steeghs, D; Schwarz, R; Rau, A; Hagen, H J
2009-01-01T23:59:59.000Z
Context. We present time-resolved spectroscopy and photometry of HS 0218+3229, a new long-period cataclysmic variable discovered within the Hamburg Quasar Survey. It is one of the few systems that allow a dynamical measurement of the masses of the stellar components. Aims. We combine the analysis of time-resolved optical spectroscopy and R-band photometry with the aim of measuring the mass of the white dwarf and the donor star and the orbital inclination. Methods. Cross-correlation of the spectra with K-type dwarf templates is used to derive the radial velocity curve of the donor star. An optimal subtraction of the broadened templates is performed to measure the rotational broadening and constrain the spectral type of the donor. Finally, an ellipsoidal model is fitted to the R-band light curve to obtain constraints upon the orbital inclination of the binary system. Results. The orbital period of HS 0218+3229 is found to be 0.297229661 +- 0.000000001 d (7.13351186 +- 0.00000002 h), and the amplitude of the don...
Quasilocal conservation laws in XXZ spin-1/2 chains: open, periodic and twisted boundary conditions
Tomaz Prosen
2014-08-05T23:59:59.000Z
A continuous family of quasilocal exact conservation laws is constructed in the anisotropic Heisenberg (XXZ) spin-1/2 chain for periodic (or twisted) boundary conditions and for a set of commensurate anisotropies densely covering the entire easy plane interaction regime. All local conserved operators follow from the standard (Hermitian) transfer operator in fundamental representation (with auxiliary spin s=1/2), and are all even with respect to a spin flip operation. However, the quasilocal family is generated by differentiation of a non-Hermitian highest weight transfer operator with respect to a complex auxiliary spin representation parameter s and includes also operators of odd parity. For a finite chain with open boundaries the time derivatives of quasilocal operators are not strictly vanishing but result in operators localized near the boundaries of the chain. We show that a simple modification of the non-Hermitian transfer operator results in exactly conserved, but still quasilocal operators for periodic or generally twisted boundary conditions. As an application, we demonstrate that implementing the new exactly conserved operator family for estimating the high-temperature spin Drude weight results, in the thermodynamic limit, in exactly the same lower bound as for almost conserved family and open boundaries. Under the assumption that the bound is saturating (suggested by agreement with previous thermodynamic Bethe ansatz calculations) we propose a simple explicit construction of infinite time averages of local operators such as the spin current.
Gorban, Alexander N.
,3] to the case of open flows, such as flow in tubes or in static mixers. In the case of time-periodic velocity
Time resolved spectroscopy of the variable brown dwarf Kelu-1
F. J. Clarke; C. G. Tinney; S. T. Hodgkin
2003-01-09T23:59:59.000Z
We report the results of observations designed to investigate the spectroscopic signatures of dust clouds on the L2 brown dwarf Kelu-1. Time resolved medium resolution spectra show no significant evidence of variability in the dust sensitive TiO, CrH and FeH bandheads on the timescale of 1--24 hours. We do however report periodic variability in the psuedo-equivelent width of H-alpha consistent with the 1.8 hour rotation period previously reported for this object Clarke, Tinney & Tolley (2002). Near-contemporaneous I-band photometry shows evidence for non-periodic variability at the level of 2%.
New Systems Showing the Light-Time Effect
P. Zasche
2007-11-18T23:59:59.000Z
Two Algol-type eclipsing binary systems (EW Lyr and IV Cas) have been investigated for period changes. Our study was primarily focused on the light-time effect with an alternative explanation by magnetic activity cycles. In the case of EW Lyr we have found a third body in the orbit with a period of about 78 years, an amplitude A=0.052 days and orbital eccentricity e=0.57. For IV Cas the long period is 58 years, amplitude A=0.034 days and zero eccentricity. With these results we are also able to calculate mass functions and minimal masses of these components.
2010-01-01T23:59:59.000Z
J, Bobak M: Ambient air pollution and pregnancy outcomes: aA, Diaz-Sanchez D: Air pollution and allergy: you are whatas: Herr et al. : Air pollution exposure during critical
Laforest, Marc
superconductor (HTS) devices of increasing complexity. Different formulations (using different state variables- gular wire carrying transport current and/or subjected to an ex- ternal field require several minutes of computation on fast work- stations. The simulation of real wires and devices would involve a large increase
Fokas, A. S.
(see Rayleigh 1883). There are related phenomena of circulations in the flows under water waves and # is the kinematic viscosity then the thickness of this layer is of order (#/w) 1/2 . This boundary layer is known
Wu, Yu-Tzu; Lee, Hsin-yi; Norton, Samuel; Prina, A. Matthew; Fleming, Jane; Matthews, Fiona E.; Brayne, Carol
2014-05-22T23:59:59.000Z
/1]. 26 Reference Albanese, E, Dangour AD, Uauy R, Acosta D, Guerra M., Guerra SSG, Huang Y, Jacob K, Rodriguez JLD, Noriega LH, Salas A, Sosa AL, Sousa RM, Williams J, Ferri CP & Prince MJ. 2009. Dietary Fish And Meat Intake And Dementia In Latin... : 63-75 Prince, MJ. 2013. Dementia in China: east–west collaboration bears fruit. Lancet 381: 1967-1968. Qiu C, Strauss Ev, Bäckman L, et al. 2013. Twenty-year changes in dementia occurrence suggest decreasing incidence in central Stockholm, Sweden...
late May through mid August 2013 (dates flexible) CSU Compensation: as available CSU class credit and
Orbital and Super-Orbital Periods of 1E 1740.7-2942 and GRS 1758-258
D. M. Smith; W. A. Heindl; J. H. Swank
2002-09-13T23:59:59.000Z
Five years of Rossi X-ray Timing Explorer (RXTE) observations of the Galactic black-hole candidates 1E 1740.7-2942 and GRS 1758-258 show a periodic modulation with amplitude 3-4% in each source at 12.73 +/- 0.05 dy and 18.45 +/- 0.10 dy, respectively. We interpret the modulations as orbital, suggesting that the objects have red-giant companions. Combining the RXTE data with earlier data (Zhang, Harmon & Liang 1997) from the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory, we find a long period or quasi-period of about 600 dy in 1E 1740.7-2942, and a suggestion of a similar 600-dy period in GRS 1758-258. These timescales are longer than any yet found for either precessing systems like Her X-1 and SS 433 or binaries like LMC X-3 and Cyg X-1 with more irregular long periods.
NASA-TM-III642 Design of Inielligent Mesoscale Periodic Array
Asher, Sanford A.
i" /} , NASA-TM-III642 Design of Inielligent Mesoscale Periodic Array Structures Utilizing Smart *National Research Council hitrodoetion Mesoscale Periodic Arlay Structures (MPAS, also known as crystalline
Dalessio, J.; Provencal, J. L.; Shipman, H. L. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)] [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Sullivan, D. J.; Sullivan, T. [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand)] [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand); Kilkenny, D. [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa)] [Department of Physics, University of the Western Cape, Private Bag X17, Bellville 7535 (South Africa); Fraga, L. [Southern Observatory for Astrophysical Research, Casilla 603, La Serena (Chile)] [Southern Observatory for Astrophysical Research, Casilla 603, La Serena (Chile); Sefako, R. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa)] [South African Astronomical Observatory, P.O. Box 9, Observatory 7935 (South Africa)
2013-03-01T23:59:59.000Z
Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058-5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent when considered in unison. The pulsation frequencies vary periodically in a 12.9 year cycle and undergo secular changes that are inconsistent with simple neutrino plus photon-cooling models. The magnitude of the periodic and secular variations increases with the period of the pulsations, possibly hinting that the corresponding physical mechanism is located near the surface of the star. The phase of the periodic variations appears coupled to the sign of the secular variations. The standards for pulsation-timing-based detection of planetary companions around pulsating white dwarfs, and possibly other variables such as subdwarf B stars, should be re-evaluated. The physical mechanism responsible for this surprising result may involve a redistribution of angular momentum or a magnetic cycle. Additionally, variations in a supposed combination frequency are shown to match the sum of the variations of the parent frequencies to remarkable precision, an expected but unprecedented confirmation of theoretical predictions.
Hydraulic Characteristics of the Lower Snake River During Periods of Juvenile Fall Chinook Migration
Cook, Chris B.; Dibrani, Berhon; Richmond, Marshall C.; Bleich, Matthew D.; Titzler, P. Scott; Fu, Tao
2006-01-30T23:59:59.000Z
This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10°C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir’s epilimnion at the Clearwater/Snake River confluence is of key biological importance to juvenile fall Chinook salmon. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four lower Snake reservoirs are also heavily influenced by wind forcing at the water’s surface, and during periods of low river discharge, often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The depth of this upper warm layer and its direction of travel may also be of key biological importance to juvenile fall Chinook salmon. This report describes field data collection, modeling, and analysis of hydrodynamic and temperature conditions in the Lower Granite Reservoir during the summer flow augmentation periods of 2002, 2003, and 2004 plus a brief one-week period in 2005 of Lower Monumental, Little Goose, and Lower Granite Reservoirs. Circulation patterns in all four lower Snake River reservoirs were numerically simulated for periods of 2002, 2003, 2004, and 2005 using CE-QUAL-W2. Simulation results show that these models are sufficiently capable of matching diurnal and long term temperature and velocity changes in the reservoirs. In addition, the confluence zone of the Clearwater and Snake rivers was modeled using the 3-D model Flow3-D. This model was used to better understand mixing processing and entrainment. Once calibrated and validated, the reservoir models were used to investigate downstream impacts of alternative reservoir operation schemes, such as increasing or decreasing the ratio of Clearwater to Snake discharge. Simulation results were also linked with the particle tracking model FINS to better understand alterations of integrated metrics due to alternative operation schemes. These findings indicate that significant alterations in water temperature throughout the lower Snake River are possible by altering hypolimnetic discharges from Dworshak Reservoir and may have a significant impact on the behavior of migrating juvenile fall Chinook salmon during periods of flow augmentation.
HFIR Vessel Maximum Permissible Pressures for Operating Period 26 to 50 EFPY (100 MW)
Cheverton, R.D.; Inger, J.R.
1999-01-01T23:59:59.000Z
Extending the life of the HFIR pressure vessel from 26 to 50 EFPY (100 MW) requires an updated calculation of the maximum permissible pressure for a range in vessel operating temperatures (40-120 F). The maximum permissible pressure is calculated using the equal-potential method, which takes advantage of knowledge gained from periodic hydrostatic proof tests and uses the test conditions (pressure, temperature, and frequency) as input. The maximum permissible pressure decreases with increasing time between hydro tests but is increased each time a test is conducted. The minimum values that occur just prior to a test either increase or decrease with time, depending on the vessel temperature. The minimum value of these minimums is presently specified as the maximum permissible pressure. For three vessel temperatures of particular interest (80, 88, and 110 F) and a nominal time of 3.0 EFPY(100 MVV)between hydro tests, these pressures are 677, 753, and 850 psi. For the lowest temperature of interest (40 F), the maximum permissible pressure is 295 psi.
Search for periodicities in the experimental solar neutrino data: A wavelet approach
Ranucci, Gioacchino; Sello, Stefano [Istituto Nazionale di Fisica Nucleare, Via Celoria 16, 20133 Milan (Italy); Mathematical and Physical Models-Enel Research, Via Andrea Pisano 120, 56122 Pisa (Italy)
2007-04-01T23:59:59.000Z
The time series of the {sup 8}B solar neutrino measurements released by the Super- Kamiokande and SNO Collaborations have been recently investigated by several groups for possible modulation signatures through standard Fourier-based techniques. In this work we present an alternative analysis of the same data sets based on the wavelet approach, whose key advantage with respect to the traditional methodologies is the ability to capture and follow the time evolution of transient modulation features as well. Moreover, we show the results of the wavelet analysis applied to the mean solar magnetic field and flare index data recorded in the same data-taking period of the two experiments, with the goal of carrying out a direct check of the concurrent presence (if any) of evidence for corresponding time variations in the solar data and in the solar neutrino series. The main outcomes of this investigation are, on one hand, the clear identification of the expected annual modulation variation due to the eccentricity of the Earth's orbit, and on the other, the demonstration that no further reliable time variation signals can be unraveled, within the current experimental sensitivity, in the measured solar neutrino flux.
Lightweight Time Modeling in Timed Creol
Bjřrk, Joakim; Owe, Olaf; Schlatte, Rudolf; 10.4204/EPTCS.36.4
2010-01-01T23:59:59.000Z
Creol is an object-oriented modeling language in which inherently concurrent objects exchange asynchronous method calls. The operational semantics of Creol is written in an actor-based style, formulated in rewriting logic. The operational semantics yields a language interpreter in the Maude system, which can be used to analyze models. Recently, Creol has been applied to the modeling of systems with radio communication, such as sensor systems. With radio communication, messages expire and, if sent simultaneously, they may collide in the air. In order to capture these and other properties of distributed systems, we extended Creol's operational semantics with a notion of time. We exploit the framework of a language interpreter to use a lightweight notion of time, in contrast to that needed for a general purpose specification language. This paper presents a timed extension of Creol, including the semantics and the implementation strategy, and discusses its properties using an extended example. The approach can be...
Properties of an axially periodic magnetic field in a betatron
Zvontsov, A.A.; Filinova, V.A.; Chakhlov, V.L.
1983-07-01T23:59:59.000Z
It is shown by solving an equation for the vector potential A (r, z) of the magnetic field that under appropriate conditions the focusing properties of a betatron magnetic field are periodic with respect to the z coordinate. Under these conditions there may be several equilibrium orbits lying in parallel planes z = 0, z = z/sub 01/ xxx, z = mz/sub 01/ in the accelerator. An equation is derived for the distance z/sub 01/ between the equilibrium orbit planes for a given orbit radius r/sub 0/ and field decay exponent n/sub 0/. The operation of such accelerators is described.
Light bullets in nonlinear periodically curved waveguide arrays
Matuszewski, Michal; Garanovich, Ivan L. [Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Sukhorukov, Andrey A. [Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Centre for Ultra-high Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia)
2010-04-15T23:59:59.000Z
We predict that stable mobile spatiotemporal solitons can exist in arrays of periodically curved optical waveguides. We find two-dimensional light bullets in planar arrays with harmonic waveguide bending and three-dimensional bullets in square lattices with helical waveguide bending using variational formalism. Stability of the light-bullet solutions is confirmed by the direct numerical simulations which show that the light bullets can freely move across the curved arrays. This mobility property is a distinguishing characteristic compared to previously considered discrete light bullets which were trapped to a specific lattice site. These results suggest new possibilities for flexible spatiotemporal manipulation of optical pulses in photonic lattices.
Forced Oscillations in Fluid Tori and Quasi-Periodic Oscillations
William H. Lee
2005-10-19T23:59:59.000Z
The kilo-Hertz Quasi--Periodic Oscillations in X-ray binaries could originate within the accretion flow, and be a signature of non--linear fluid oscillations and mode coupling in strong gravity. The possibility to decipher these systems will impact our knowledge of fundamental parameters such as the neutron star mass, radius, and spin. Thus they offer the possibility to constrain the nuclear equation of state and the rotation parameter of stellar--mass black holes. We review the general properties of these oscillations from a hydrodynamical point of view, when the accretion flow is subject to external perturbations and summarize recent results.
Dense periodic packings of tetrahedra with small repeating units
Yoav Kallus; Veit Elser; Simon Gravel
2010-03-19T23:59:59.000Z
We present a one-parameter family of periodic packings of regular tetrahedra, with the packing fraction $100/117\\approx0.8547$, that are simple in the sense that they are transitive and their repeating units involve only four tetrahedra. The construction of the packings was inspired from results of a numerical search that yielded a similar packing. We present an analytic construction of the packings and a description of their properties. We also present a transitive packing with a repeating unit of two tetrahedra and a packing fraction $\\frac{139+40\\sqrt{10}}{369}\\approx0.7194$.
EIS-0391: Notice to Extend Scoping Period | Department of Energy
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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 DataDepartment of Energy Your Density Isn't Your Destiny:Revised FindingDepartment of Energy :to Extend Scoping Period EIS-0391: Notice
Tsallis Distribution Decorated With Log-Periodic Oscillation
Wilk, Grzegorz
2015-01-01T23:59:59.000Z
In many situations, in all branches of physics, one encounters power-like behavior of some variables which are best described by a Tsallis distribution characterized by a nonextensivity parameter $q$ and scale parameter $T$. However, there exist experimental results which can be described only by a Tsallis distributions which are additionally decorated by some log-periodic oscillating factor. We argue that such a factor can originate from allowing for a complex nonextensivity parameter $q$. The possible information conveyed by such an approach (like the occurrence of complex heat capacity, the notion of complex probability or complex multiplicative noise) will also be discussed.
Noncommutative Two Time Physics
W. Chagas-Filho
2006-05-10T23:59:59.000Z
We present a classical formalism describing two-time physics with Abelian canonical gauge field backgrounds. The formalism can be used as a starting point for the construction of an interacting quantized two-time physics theory in a noncommutative soace-time.
Quantum Operation Time Reversal
Crooks, Gavin E.
2008-03-25T23:59:59.000Z
The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.
Turbulent transport phenomena in a channel with periodic rib turbulators
Liou, T.M.; Hwang, J.J.; Chen, S.H. (National Tsing Hua University, Hsinchu (Taiwan))
1992-09-01T23:59:59.000Z
Periodic fully developed turbulent flow in a 2D channel with rib turbulators on two opposite walls has been studied numerically and experimentally. In numerical predictions, an algebraic Reynolds stress turbulence model is adopted, and a smoothed hybrid central/skew upstream difference scheme is developed. In experiments, the laser-Doppler velocimetry and laser holographic interferometry are employed to measure the local flow and heat transfer characteristics. The results are obtained with the ratio of pitch to rib height 5, 10, 15, and 20, for Reynolds number of 3.3 x 10 exp 4 and are presented in terms of the reattachment length, mean velocity and turbulent kinetic energy profiles, isotherm patterns, and distributions of local pressure recovery and Nusselt number. A detailed comparison with experimental data shows that the present calculations have an improvement over the previous work in the prediction of periodic ribbed-wall flow and heat transfer. In addition, regions susceptible to hot spots are identified by examining the distributions of the local Nusselt number. Furthermore, the enhancement of mean Nusselt number is documented in terms of relative contributions of the increased turbulence intensity and surface area provided by the ribs. 32 refs.
Periodicity of the solar full-disk magnetic fields
Xiang, N. B.; Qu, Z. N.; Zhai, Q. [National Astronomical Observatories/Yunnan Observatory, CAS, Kunming 650011 (China)
2014-07-01T23:59:59.000Z
A full-disk solar magnetogram has been measured each day since 1970 January 19, and the daily Magnetic Plage Strength Index (MPSI) and the daily Mount Wilson Sunspot Index (MWSI) were calculated for each magnetogram at the Mount Wilson Observatory. The MPSI and MWSI are used to investigate the periodicity of the solar full-disk magnetic activity through autocorrelation analyses. Just two periods, the solar cycle and the rotation cycle, are determined in both the MPSI (the solar full-disk weak magnetic field activity) and MWSI (the solar full-disk strong magnetic field activity) with no annual signal found. The solar cycle for MPSI (10.83 yr) is found to be obviously longer than that for MWSI (9.77 yr). The rotation cycle is determined to be 26.8 ± 0.63 sidereal days for MPSI and 27.4 ± 2.4 sidereal days for MWSI. The rotation cycle length for MPSI is found to fluctuate around 27 days within a very small amplitude, but for MWSI it obviously temporally varies with a rather large amplitude. The rotation cycle for MWSI seems longer near solar minimum than at solar maximum. Cross-correlation analyses of daily MPSI and MWSI are carried out, and it is inferred that the MPSI components partly come from relatively early MWSI measurements.
DOE Extends Public Comment Period for the Draft Uranium Leasing...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
25,000 acres - that are leased to private entities for uranium and vanadium mining. No mining operations are active on these lands at this time. DOE is preparing the ULP...
DOE Extends Public Comment Period for Uranium Program Environmental...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
25,000 acres - that are leased to private entities for uranium and vanadium mining. No mining operations are active on these lands at this time. DOE is preparing the ULP...
Effect of Materials and Curing Period on Shrinkage of Concrete
West, Maria B.
2010-02-04T23:59:59.000Z
shrinkage reducing admixture at a dosage rate of 2 percent by weight of cement reduced the shrinkage of concrete nearly 32 percent after 365 days. The shrinkage reducing admixture, however, produced concrete that at times exhibited an unstable air content....
Broader source: Energy.gov [DOE]
Energy Conservation Program for Consumer Products: Test Procedures for Furnaces and Boilers, Comment Period Extension
All-sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data
J. Abadie; B. P. Abbott; R. Abbott; T. D. Abbott; M. Abernathy; T. Accadia; F. Acernese; C. Adams; R. Adhikari; C. Affeldt; P. Ajith; B. Allen; G. S. Allen; E. Amador Ceron; D. Amariutei; R. S. Amin; S. B. Anderson; W. G. Anderson; K. Arai; M. A. Arain; M. C. Araya; S. M. Aston; P. Astone; D. Atkinson; P. Aufmuth; C. Aulbert; B. E. Aylott; S. Babak; P. Baker; G. Ballardin; S. Ballmer; D. Barker; F. Barone; B. Barr; P. Barriga; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; M. Bastarrika; A. Basti; J. Batch; J. Bauchrowitz; Th. S. Bauer; M. Bebronne; B. Behnke; M. G. Beker; A. S. Bell; A. Belletoile; I. Belopolski; M. Benacquista; J. M. Berliner; A. Bertolini; J. Betzwieser; N. Beveridge; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; R. Biswas; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; B. Bland; M. Blom; O. Bock; T. P. Bodiya; C. Bogan; R. Bondarescu; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; S. Bose; L. Bosi; B. Bouhou; S. Braccini; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; J. Breyer; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; A. Brummit; T. Bulik; H. J. Bulten; A. Buonanno; J. Burguet--Castell; O. Burmeister; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Cain; E. Calloni; J. B. Camp; P. Campsie; J. Cannizzo; K. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; S. Caride; S. Caudill; M. Cavagliŕ; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; O. Chaibi; T. Chalermsongsak; E. Chalkley; P. Charlton; E. Chassande-Mottin; S. Chelkowski; Y. Chen; A. Chincarini; A. Chiummo; H. Cho; N. Christensen; S. S. Y. Chua; C. T. Y. Chung; S. Chung; G. Ciani; F. Clara; D. E. Clark; J. Clark; J. H. Clayton; F. Cleva; E. Coccia; P. -F. Cohadon; C. N. Colacino; J. Colas; A. Colla; M. Colombini; A. Conte; R. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corsi; C. A. Costa; M. Coughlin; J. -P. Coulon; P. Couvares; D. M. Coward; D. C. Coyne; J. D. E. Creighton; T. D. Creighton; A. M. Cruise; A. Cumming; L. Cunningham; E. Cuoco; R. M. Cutler; K. Dahl; S. L. Danilishin; R. Dannenberg; S. D'Antonio; K. Danzmann; V. Dattilo; B. Daudert; H. Daveloza; M. Davier; G. Davies; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; D. DeBra; G. Debreczeni; J. Degallaix; W. Del Pozzo; M. del Prete; T. Dent; V. Dergachev; R. DeRosa; R. DeSalvo; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; M. Di Paolo Emilio; A. Di Virgilio; M. Díaz; A. Dietz; F. Donovan; K. L. Dooley; S. Dorsher; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; J. -C. Dumas; S. Dwyer; T. Eberle; M. Edgar; M. Edwards; A. Effler; P. Ehrens; G. Endr?czi; R. Engel; T. Etzel; K. Evans; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Y. Fan; B. F. Farr; W. Farr; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Fidecaro; L. S. Finn; I. Fiori; R. P. Fisher; R. Flaminio; M. Flanigan; S. Foley; E. Forsi; L. A. Forte; N. Fotopoulos; J. -D. Fournier; J. Franc; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; D. Friedrich; P. Fritschel; V. V. Frolov; P. J. Fulda; M. Fyffe; M. Galimberti; L. Gammaitoni; M. R. Ganija; J. Garcia; J. A. Garofoli; F. Garufi; M. E. Gáspár; G. Gemme; R. Geng; E. Genin; A. Gennai; L. Á. Gergely; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; C. Gill; E. Goetz; L. M. Goggin; G. González; M. L. Gorodetsky; S. Goßler; R. Gouaty; C. Graef; M. Granata; A. Grant; S. Gras; C. Gray; N. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Greverie; R. Grosso; H. Grote; S. Grunewald; G. M. Guidi; C. Guido; R. Gupta; E. K. Gustafson; R. Gustafson; T. Ha; B. Hage; J. M. Hallam; D. Hammer; G. Hammond; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. T. Hartman; K. Haughian; K. Hayama; J. -F. Hayau; T. Hayler; J. Heefner; A. Heidmann; M. C. Heintze; H. Heitmann; P. Hello; M. A. Hendry; I. S. Heng; A. W. Heptonstall; V. Herrera; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; K. Holt; T. Hong; S. Hooper; D. J. Hosken; J. Hough; E. J. Howell; B. Hughey; S. Husa; S. H. Huttner; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; K. Izumi; M. Jacobson; H. Jang; P. Jaranowski; W. W. Johnson; D. I. Jones; G. Jones; R. Jones; L. Ju; P. Kalmus; V. Kalogera; I. Kamaretsos; S. Kandhasamy; G. Kang; J. B. Kanner; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kawabe; S. Kawamura; F. Kawazoe; W. Kells; D. G. Keppel; Z. Keresztes; A. Khalaidovski; F. Y. Khalili; E. A. Khazanov; B. Kim; C. Kim; D. Kim; H. Kim; K. Kim; N. Kim; Y. -M. Kim; P. J. King; M. Kinsey; D. L. Kinzel; J. S. Kissel; S. Klimenko; K. Kokeyama; V. Kondrashov; R. Kopparapu; S. Koranda; W. Z. Korth; I. Kowalska; D. Kozak; V. Kringel; S. Krishnamurthy; B. Krishnan; A. Królak
2011-10-02T23:59:59.000Z
We report on an all-sky search for periodic gravitational waves in the frequency band 50-800 Hz and with the frequency time derivative in the range of 0 through -6e-9 Hz/s. Such a signal could be produced by a nearby spinning and slightly non-axisymmetric isolated neutron star in our galaxy. After recent improvements in the search program that yielded a 10x increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational wave strain to date. Near 150 Hz our upper limit on worst-case linearly polarized strain amplitude $h_0$ is 1e-24, while at the high end of our frequency range we achieve a worst-case upper limit of 3.8e-24 for all polarizations and sky locations. These results constitute a factor of two improvement upon previously published data. A new detection pipeline utilizing a Loosely Coherent algorithm was able to follow up weaker outliers, increasing the volume of space where signals can be detected by a factor of 10, but has not revealed any gravitational wave signals. The pipeline has been tested for robustness with respect to deviations from the model of an isolated neutron star, such as caused by a low-mass or long-period binary companion.
All-sky LIGO Search for Periodic Gravitational Waves in the Early S5 Data
LIGO Scientific Collaboration
2008-10-01T23:59:59.000Z
We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50--1100 Hz and with the frequency's time derivative in the range -5.0E-9 Hz/s to zero. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semi-coherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 1.E-24 are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 1.0E-6, the search is sensitive to distances as great as 500 pc--a range that could encompass many undiscovered neutron stars, albeit only a tiny fraction of which would likely be rotating fast enough to be accessible to LIGO. This ellipticity is at the upper range thought to be sustainable by conventional neutron stars and well below the maximum sustainable by a strange quark star.
Extracting Periodic Transit Signals from Noisy Light Curves using Fourier Series
Samsing, Johan
2015-01-01T23:59:59.000Z
We present a simple and powerful method for extracting a transit signal from noisy light curves. Assuming the signal is periodic, we illustrate that systematic noise can be removed in Fourier space at all frequencies, by only using data from inside a time window which is matched to the main planet transits. This results in a reconstruction of the signal which on average is unbiased, despite that no prior knowledge of either the noise or the transit signal itself is used in the analysis. The method has therefore clear advantages over standard phase folding, which normally requires external input such as nearby stars or noise models for removing systematic components. In addition, we extract the full 360 degree transit signal simultaneously, and Kepler like data can be analyzed in just a few seconds. We illustrate the performance of our method by applying it to a dataset composed of light curves from Kepler with a fake injected signal emulating a planet with rings. For extracting periodic transit signals, our p...
Resonant quantum dynamics of few ultracold bosons in periodically driven finite lattices
Mistakidis, S I; Negretti, A; Schmelcher, P
2015-01-01T23:59:59.000Z
The out-of-equilibrium dynamics of finite ultracold bosonic ensembles in periodically driven one-dimensional optical lattices is investigated. Our study reveals that the driving enforces the bosons in different wells to oscillate in-phase and to exhibit a dipole-like mode. A wide range from weak-to-strong driving frequencies is covered and a resonance-like behaviour of the intra-well dynamics is discussed. In the proximity of the resonance a rich intraband excitation spectrum is observed. The single particle excitation mechanisms are studied in the framework of Floquet theory elucidating the role of the driving frequency. The impact of the interatomic repulsive interactions is examined in detail yielding a strong influence on the tunneling period and the excitation probabilities. Finally, the dependence of the resonance upon a variation of the tunable parameters of the optical lattice is examined. Our analysis is based on the ab-initio Multi-Configuration Time-Dependent Hartree Method for bosons.
Gu Zhanji; Ge Weigao [Department of Computer Science, Hainan Normal University, Haikou, HaiNan 571158 (China) and Department of Applied Mathematics, Beijing Institute of Technology, Beijing 100081 (China); Department of Applied Mathematics, Beijing Institute of Technology, Beijing 100081 (China)
2006-09-15T23:59:59.000Z
By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, we study the existence, uniqueness, and global exponential stability of periodic solution for shunting inhibitory cellular neural networks with impulses, dx{sub ij}/dt=-a{sub ij}x{sub ij}-{sigma}{sub C{sub K}{sub 1}}{sub (set-membershipsign)=N{sub r}{sub (i,j)}C{sub ij}{sup kl}f{sub ij}[x{sub kl}(t)]x{sub ij}+L{sub ij}(t), t>0,t{ne}t{sub k}; {delta}x{sub ij}(t{sub k})=x{sub ij}(t{sub k}{sup +})-x{sub ij}(t{sub k}{sup -})=I{sub k}[x{sub ij}(t{sub k})], k=1,2,... . Furthermore, the numerical simulation shows that our system can occur in many forms of complexities, including periodic oscillation and chaotic strange attractor. To the best of our knowledge, these results have been obtained for the first time. Some researchers have introduced impulses into their models, but analogous results have never been found.
Aliev, Gazi N., E-mail: g.aliev@bath.ac.uk; Goller, Bernhard [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)
2014-09-07T23:59:59.000Z
A one-dimensional Fibonacci phononic crystal and a distributed Bragg reflector were constructed from porous silicon. The structures had the same number of layers and similar acoustic impedance mismatch, and were electrochemically etched in highly boron doped silicon wafers. The thickness of the individual layers in the stacks was approximately 2??m. Both types of hypersonic band gap structure were studied by direct measurement of the transmittance of longitudinal acoustic waves in the 0.1–2.6?GHz range. Acoustic band gaps deeper than 50?dB were detected in both structures. The experimental results were compared with model calculations employing the transfer matrix method. The acoustic properties of periodic and quasi-periodic structures in which half-wave retarding bi-layers do not consist of two quarter-wave retarding layers are discussed. The strong correlation between width and depth of gaps in the transmission spectra is demonstrated. The dominant mechanisms of acoustic losses in porous multilayer structures are discussed. The elastic constants remain proportional over our range of porosity, and hence, the Grüneisen parameter is constant. This simplifies the expression for the porosity dependence of the Akhiezer damping.
Release of Methane from Bering Sea Sediments During the Last Glacial Period
Mea Cook; Lloyd Keigwin
2007-11-30T23:59:59.000Z
Several lines of evidence suggest that during times of elevated methane flux the sulfate-methane transition zone (SMTZ) was positioned near the sediment-water interface. We studied two cores (from 700 m and 1457 m water depth) from the Umnak Plateau region. Anomalously low d13C and high d18O in benthic and planktonic foraminifera in these cores are the consequence of diagenetic overgrowths of authigenic carbonates. There are multiple layers of authigenic-carbonate-rich sediment in these cores, and the stable isotope compositions of the carbonates are consistent with those formed during anaerobic oxidation of methane (AOM). The carbonate-rich layers are associated with biomarkers produced by methane-oxidizing archaea, archaeol and glyceryl dibiphytanyl glyceryl tetraether (GDGT). The d13C of the archaeol and certain GDGTs are isotopically depleted. These carbonate- and AOM-biomarker-rich layers were emplaced in the SMTZ during episodes when there was a high flux of methane or methane-rich fluids upward in the sediment column. The sediment methane in the Umnak Plateau region appears to have been very dynamic during the glacial period, and interacted with the ocean-atmosphere system at millennial time scales. The upper-most carbonate-rich layers are in radiocarbon-dated sediment deposited during interstitials 2 and 3, 28-20 ka, and may be associated with the climate warming during this time.
Assessing historical global sulfur emission patterns for the period 1850--1990
Lefohn, A.S. [A.S.L. and Associates, Helena, MT (United States); Husar, J.D.; Husar, R.B. [Washington Univ., St. Louis, MO (United States). Center for Air Pollution Impact and Trend Analysis; Brimblecombe, P. [Univ. of East Anglia, Norwich (United Kingdom)
1996-07-19T23:59:59.000Z
Anthropogenic sulfur dioxide emissions from energy-producing and metal production activities have become an important factor in better understanding the relationship between humans and the environment. Concerns about (1) acid rain effects on the environment and (2) anthropogenic aerosols affecting possible global change have prompted interest in the transformation and fate of sulfur in the environment. One step in assessing the importance of sulfur emissions is the development of a reliable regional emission inventory of sulfur as a function of time. The objective of this research effort was to create a homogeneous database for historical sulfur emission estimates for the world. The time from 1850--1990 was selected to include the period of industrialization form the time the main production of fuels and minerals began until the most recent year for which complete production data exist. This research effort attempts to correct some of the deficiencies associated with previous global sulfur emission estimates by (1) identifying those production activities that resulted in sulfur emissions by country and (2) calculating historical emission trends by country across years. An important component of this study was the comparison of the sulfur emission results with those of previous studies.
Dynamically tunable Fano resonance in periodically asymmetric graphene nanodisk pair
Zhang, Zhengren; Fan, Yuancheng; Yin, Pengfei; Zhang, Liwei; Shi, Xi
2015-01-01T23:59:59.000Z
We present a dynamically frequency tunable Fano resonance planar device composed of periodically asymmetric graphene nanodisk pair for the mid-infrared region. There are two kinds of modes in this structure, that is, the symmetric mode and the antisymmetric mode. The resonance coupling between the symmetric and antisymmetric modes creates a classical Fano resonance. Both of the Fano resonance amplitude and frequency of the structure can be dynamically controlled by varying the Fermi energy of graphene. Resonance transition in the structure is studied to reveal the physical mechanism behind the dynamically tunable Fano resonance. The features of the Fano resonant graphene nanostructures should have promising applications in tunable THz filters, switches, and modulators.
Periodic relativity: deflection of light, acceleration, rotation curves
Vikram H. Zaveri
2014-12-08T23:59:59.000Z
Vectorial analysis relating to derivation of deflection of light is presented. Curvilinear acceleration is distinguished from the Newtonian polar conic acceleration. The difference between the two is due to the curvature term. Lorentz invariant expression for acceleration is derived. A physical theory of rotation curves of galaxies based on second solution to Einstein's field equation is presented. Theory is applied to Milky Way, M31, NGC3198 and Solar system. Modified Kepler's third law yields correct orbital periods of stars in a galaxy. Deviation factor in the line element of the theory happens to be the ratio of the Newtonian gravitational acceleration to the measured acceleration of the star in the galaxy. Therefore this deviation factor can replace the MOND function.
A Radio SETI Campaign for microsec-sec Periodic Signals
Harp, G R; Astorga, Alfredo; Arbunich, Jack; Hightower, Kristin; Meitzner, Seth; Barott, W C; Nolan, Michael C; Messerschmitt, D G; Vakoch, Douglas A; Shostak, Seth; Tarter, J C
2015-01-01T23:59:59.000Z
We report a novel radio autocorrelation (AC) search for extraterrestrial intelligence (SETI). For selected frequencies across the terrestrial microwave window (1-10 GHz) observations were conducted at the Allen Telescope Array to identify artificial non-sinusoidal periodic signals with radio bandwidths greater than 1 kHz, which are capable of carrying substantial messages with symbol-rates from 10-10e6 Hz. Out of 243 observations, about half (101) were directed toward sources with known continuum flux greater than 1 Jy (quasars, pulsars, supernova remnants and masers), based on the hypothesis that they might harbor heretofore undiscovered natural or artificial, repetitive, phase or frequency modulation. The rest of the targets were mostly toward exoplanet stars and similarly interesting targets from the standpoint of SETI. This campaign rules out several previously untested hypotheses relating to the number of artificially modulated "natural" sources. Since we are using a phase sensitive detector, these obser...
Periodic forcing of a 555-IC based hysteretic oscillator
Moises Santillan
2014-08-12T23:59:59.000Z
In this work we designed and developed a master-slave electronic oscillatory system (based on the 555-timer IC working in the astable mode), and investigated its dynamic behavior regarding synchronization. For that purpose we measured the circulation number corresponding to the phase-locking rhythm achieved in a large set of values of the normalized forcing period (NFP) and of the coupling strength between the master and the slave oscillators. In particular we were interested in the system behavior in the strong-coupling limit, because such problem has not been extensively studied from an experimental perspective. Our results indicate the existence of a degenerate codimension-2 bifurcation point at NFP=1:2, where all the phase-locking regions converge in the very strong coupling limit. These findings were corroborated by a mathematical model we developed to that end.
Transverse commensurability effect for vortices on periodic pinning arrays
Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, Cynthia J [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
Using computer simulations, we demonstrate a type of commensurability that occurs for vortices moving longitudinally through periodic pinning arrays in the presence of an additional transverse driving force. As a function of vortex density, there is a series of broad maxima in the transverse critical depinning force that do not fall at the matching fields where the number of vortices equals an integer multiple of the number of pinning sites. The commensurability effects are associated with dynamical states in which evenly spaced structures consisting of one or more moving rows of vortices form between rows of pinning sites. Remarkably, the critical transverse depinning force can be more than an order of magnitude larger than the longitudinal depinning force.
Yousef Ghazi-Tabatabai
2012-11-19T23:59:59.000Z
While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.
Search for periodic gravitational radiation with the ALLEGRO gravitational wave detector
E. Mauceli; M. P. McHugh; W. O. Hamilton; W. W. Johnson; A. Morse
2000-07-11T23:59:59.000Z
We describe the search for a continuous signal of gravitational radiation from a rotating neutron star in the data taken by the ALLEGRO gravitational wave detector in early 1994. Since ALLEGRO is sensitive at frequencies near 1 kHz, only neutron stars with spin periods near 2 ms are potential sources. There are no known sources of this typ e for ALLEGRO, so we directed the search towards both the galactic center and the globular clus ter 47 Tucanae. The analysis puts a constraint of roughly $8 \\times 10^{-24}$ at frequencies near 1 kHz on the gravitational strain emitted from pulsar spin-down in either 47 Tucanae or the galactic center.
Search for periodic gravitational radiation with the ALLEGRO gravitational wave detector
Mauceli, E; Hamilton, W O; Johnson, W W; Morse, A
2002-01-01T23:59:59.000Z
We describe the search for a continuous signal of gravitational radiation from a rotating neutron star in the data taken by the ALLEGRO gravitational wave detector in early 1994. Since ALLEGRO is sensitive at frequencies near 1 kHz, only neutron stars with spin periods near 2 ms are potential sources. There are no known sources of this typ e for ALLEGRO, so we directed the search towards both the galactic center and the globular clus ter 47 Tucanae. The analysis puts a constraint of roughly $8 \\times 10^{-24}$ at frequencies near 1 kHz on the gravitational strain emitted from pulsar spin-down in either 47 Tucanae or the galactic center.
General model selection estimation of a periodic regression with a Gaussian noise
Konev, Victor; 10.1007/s10463-008-0193-1
2010-01-01T23:59:59.000Z
This paper considers the problem of estimating a periodic function in a continuous time regression model with an additive stationary gaussian noise having unknown correlation function. A general model selection procedure on the basis of arbitrary projective estimates, which does not need the knowledge of the noise correlation function, is proposed. A non-asymptotic upper bound for quadratic risk (oracle inequality) has been derived under mild conditions on the noise. For the Ornstein-Uhlenbeck noise the risk upper bound is shown to be uniform in the nuisance parameter. In the case of gaussian white noise the constructed procedure has some advantages as compared with the procedure based on the least squares estimates (LSE). The asymptotic minimaxity of the estimates has been proved. The proposed model selection scheme is extended also to the estimation problem based on the discrete data applicably to the situation when high frequency sampling can not be provided.
Hierarchical Hough all-sky search for periodic gravitational waves in LIGO S5 data
Llucia Sancho de la Jordana; for the LIGO Scientific Collaboration; the Virgo Collaboration
2010-01-21T23:59:59.000Z
We describe a new pipeline used to analyze the data from the fifth science run (S5) of the LIGO detectors to search for continuous gravitational waves from isolated spinning neutron stars. The method employed is based on the Hough transform, which is a semi-coherent, computationally efficient, and robust pattern recognition technique. The Hough transform is used to find signals in the time-frequency plane of the data whose frequency evolution fits the pattern produced by the Doppler shift imposed on the signal by the Earth's motion and the pulsar's spin-down during the observation period. The main differences with respect to previous Hough all-sky searches are described. These differences include the use of a two-step hierarchical Hough search, analysis of coincidences among the candidates produced in the first and second year of S5, and veto strategies based on a $\\chi^2$ test.
High field pulsed microwiggler comprising a conductive tube with periodically space slots
Warren, Roger W. (Santa Fe, NM)
1992-01-01T23:59:59.000Z
A microwiggler assembly produces large magnetic fields for oscillating ched particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180.degree. relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube.
High field pulsed microwiggler comprising a conductive tube with periodically space slots
Warren, R.W.
1992-09-01T23:59:59.000Z
A microwiggler assembly produces large magnetic fields for oscillating charged particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180[degree] relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube. 10 figs.
Unipolar half-cycle pulse generation in asymmetrical media with a periodic subwavelength structure
Song Xiaohong; Yang Weifeng; Zeng Zhinan; Li Ruxin; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)
2010-11-15T23:59:59.000Z
We present a method to generate an extremely short unipolar half-cycle pulse based on resonant propagation of a few-cycle pulse through asymmetrical media with periodic subwavelength structure. Moreover, single- and few-cycle gap solitons with different frequencies are found to split from one incident few-cycle ultrashort pulse. These solitons with various frequencies provide evidence for the generation of different parametric waves during the strong light-matter coupling in asymmetrical media under the extreme nonlinear optics condition. Because of the pulse self-shaping process during the course of resonant propagation, the generated low-frequency sideband and another broadband continuum sideband ranging from the visible to the near-infrared regime couple together, which results in the generation of the subfemtosecond unipolar half-cycle pulse. A time-frequency analysis is preformed which corroborates the mechanism. The generated unipolar half-cycle pulse might be utilized to control and probe the ultrafast electronic dynamics.
Finding zeros of the Riemann zeta function by periodic driving of cold atoms
C. E. Creffield; G. Sierra
2015-05-07T23:59:59.000Z
The Riemann hypothesis, which states that the non-trivial zeros of the Riemann zeta function all lie on a certain line in the complex plane, is one of the most important unresolved problems in mathematics. Inspired by the P\\'olya-Hilbert conjecture, we propose a new approach to finding a physical system to study the Riemann zeros, which in contrast to previous examples, is based on applying a time-periodic driving field. This driving allows us to mould the quasienergies of the system (the analogue of the eigenenergies in the absence of driving), so that they are directly governed by the zeta function. We further show by numerical simulations that this allows the Riemann zeros to be measured in currently accessible cold atom experiments.
Neighboring Interactions in a Periodic Plasmonic Material for Solar-Thermal Energy Conversion
Musho, Terence D; Coppens, Zackary J
2015-01-01T23:59:59.000Z
A periodic plasmonic meta-material was studied using finite-difference time domain (FDTD) method to investigate the influence of neighboring particles on the near unity optical absorptivity. The meta-material was constructed as a silver nanoparticle (20-90nm) situated above an alumina (Al$_2$O$_3$) dielectric environment. A full parametric sweep of the particle width and the dielectric thickness was conducted. Computational results identified several resonances between the metal-dielectric and metal-air that have potential to broadening the response through stacked geometry. A significant coupled resonance between the metal-dielectric resonance and a cavity resonance between particles was capture as a function of dielectric thickness. This coupled resonance was not evident below dielectric thicknesses of 40nm and above cavity widths of 20nm. Additionally, a noticeable propagating surface plasmon polariton resonance was predicted when the particle width was half the unit cell length.
Physics Division progress report for period ending September 30, 1984
Livingston, A.B. (ed.)
1985-01-01T23:59:59.000Z
The research activities of the Division are centered primarily in three areas: experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. The largest of these efforts, experimental nuclear physics, is dominated by the heavy ion research program. A major responsibility under this program is the operation of the Holifield Heavy Ion Research Facility as a national user facility. During the period of this report, the facility has begun routine operation for the experimental program. The experimental atomic physics program has two components: the accelerator-based studies of basic collisional phenomena and the studies in support of the controlled fusion program. Also associated with the fusion-related studies are a plasma diagnostics program and the operation of an atomic physics data center. The theoretical physics program, both nuclear and atomic, is covered. This program has benefited this year from the success of the VAX-AP computer system and from the increase in manpower provided by the ORNL/University of Tennessee Distinguished Scientist Program. Smaller programs in applications and high-energy physics are summarized. During the period of this report, we continued to explore possible future extensions of the Holifield Facility. We retain a strong interest in a relativistic heavy-ion collider in the 10 x 10 GeV/nuclear energy range. The ideas for such a facility, described in last year's report, have been modified to utilize the HHIRF 25 MV tandem accelerator as the first stage. Finally, the report concludes with some general information on publications, Division activities, and personnel changes.
White, Lynn
2000-06-27T23:59:59.000Z
, you expect unused time to come around again, so that when the same opportunities appear you will be wiser about how to use it. Consider how your cultural background af_fects the w ay you plan and manage time. W *Both cited in Bauer, J. It?s Time.... Effective time management means decid- ing which activity should be done from all the possibilities available, and then doing it. It is a matter of setting priorities. Deciding which jobs are most important and working on those may be better than doing less...
Intrinsic Time Quantum Geometrodynamics
Eyo Eyo Ita III; Chopin Soo; Hoi-Lai Yu
2015-02-06T23:59:59.000Z
Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.
Intrinsic Time Quantum Geometrodynamics
Ita, Eyo Eyo; Yu, Hoi-Lai
2015-01-01T23:59:59.000Z
Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental canonical commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.
TRANSPORT OF HEAT, WATER VAPOR AND CARBON DOXIDE BY LONG PERIOD EDDIES IN THE STABLE BOUNDARY LAYER
Kurzeja, R.
2010-07-26T23:59:59.000Z
The vertical transport of heat and trace chemicals for a night in April has been studied with a wavelet analysis and conventional one-hour averages. It was found that for the night of April 20, 2009, turbulent kinetic energy, heat and trace chemicals were transported directed downward from the jet core. The most significant periods for this transport were less than 5 minutes and greater than one hour with intermittent transport taking place in the 5 min to 1 hour time frame. The nocturnal boundary layer is characterized by turbulent intermittency, long period oscillations, and a slow approach to equilibrium, (Mahrt, 1999). Although turbulence is usually maintained by surface friction, downward transport from low-level jets can also play an important role in turbulence maintenance and in the transport of scalars, Mahrt (1999), Banta et al. (2006). The eddy covariance flux measurement technique assumes continuous turbulence which is unusual in the stable boundary because significant flux transport occurs via turbulent eddies whose periods are long compared with the averaging time (Goulden et al., 1996). Systematic error in eddy flux measurements is attributed mainly to the neglect of long period eddies. Banta et al. (2006) noted that observations of turbulence below the low level jet suggested that while upward transport of turbulence kinetic energy (TKE) is common, downward transport from the jet can also occur. They found that in the CASES 99 experiments that turbulence scaled well with the strength of the low-level jet, and that surface cooling was more important than surface roughness. Because nocturnal turbulence is intermittent and non-stationary, the appropriate averaging time for calculation of TKE and EC fluxes is not obvious. Wavelet analysis is, thus, a more suitable analysis tool than conventional Fourier analysis.
Developing Improved Travel Time Reliability Measures For Real-time
Bertini, Robert L.
reliability Use for prioritizing improvements Outline #12; 95th Percentile Travel Time Travel Time Index: mean travel time divided by free flow travel time Buffer Index: difference between 95th percentile travel time and mean travel time, divided by mean travel time Planning Time Index: 95th percentile
Reducing EnergyPlus Run Time For Code Compliance Tools
Athalye, Rahul A.; Gowri, Krishnan; Schultz, Robert W.; Glazer, Jason
2014-09-12T23:59:59.000Z
Integration of the EnergyPlus ™ simulation engine into performance-based code compliance software raises a concern about simulation run time, which impacts timely feedback of compliance results to the user. EnergyPlus annual simulations for proposed and code baseline building models, and mechanical equipment sizing result in simulation run times beyond acceptable limits. This paper presents a study that compares the results of a shortened simulation time period using 4 weeks of hourly weather data (one per quarter), to an annual simulation using full 52 weeks of hourly weather data. Three representative building types based on DOE Prototype Building Models and three climate zones were used for determining the validity of using a shortened simulation run period. Further sensitivity analysis and run time comparisons were made to evaluate the robustness and run time savings of using this approach. The results of this analysis show that the shortened simulation run period provides compliance index calculations within 1% of those predicted using annual simulation results, and typically saves about 75% of simulation run time.
RXJ0806.3+1527: a double degenerate binary with the shortest known orbital period (321s)
G. L. Israel; W. Hummel; S. Covino; S. Campana; I. Appenzeller; W. Gassler; K. -H. Mantel; G. Marconi; C. W. Mauche; U. Munari; I. Negueruela; H. Nicklas; G. Rupprecht; R. L. Smart; O. Stahl; L. Stella
2002-03-04T23:59:59.000Z
We carried out optical observations of the field of the X-ray pulsator RXJ0806.3+1527. A blue V=21.1 star was found to be the only object consistent with the X-ray position. VLT FORS spectra revealed a blue continuum with no intrinsic absorption lines. Broad (v~1500 km/s), low equivalent width (about -1/-6A) emission lines from the HeII Pickering series were clearly detected. B, V and R time-resolved photometry revealed the presence of about 15% pulsations at the 321s X-ray period, confirming the identification. These findings, together with the period stability and absence of any additional modulation in the 1min-5hr period range, argue in favour of the orbital interpretation of the 321s pulsations. The most likely scenario is thus that RXJ0806.3+1527 is a double degenerate system of the AM CVn class. This would make RXJ0806.3+1527 the shortest orbital period binary currently known and one of the best candidates for gravitational wave detection.
Roweis, Sam
SCIA 2003 Tutorial: Hidden Markov Models Sam Roweis, University of Toronto June 29, 2003 Probabilistic Generative Models for Time Series #15; Stochastic models for time-series: y 1 ; y 2 ; : : : ; y #15; Add noise to make the system stochastic: p(y t jy t 1 ;y t 2 ; : : : ;y t k ) #15; Markov models
S. Davood Sadatian
2014-05-08T23:59:59.000Z
In this article, we discuss probability of inhomogeneous time in high or low energy scale of physics. Consequently, the possibility was investigated of using theories such as varying speed of light (VSL) and fractal mathematics to build a framework within which answers can be found to some of standard cosmological problems and physics theories on the basis of time non-homogeneity.
A. Boyarsky; P Gora
2007-05-07T23:59:59.000Z
We present a definition of time measurement based on high energy photons and the fundamental length scale, and show that, for macroscopic time, it is in accord with the Lorentz transformation of special relativity. To do this we define observer in a different way than in special relativity.
M. Heller; W. Sasin
1997-11-17T23:59:59.000Z
In the groupoid approach to noncommutative quantization of gravity, gravitational field is quantized in terms of a C*-algebra A of complex valued funcions on a groupoid G (with convolution as multiplication). In the noncommutative quantum gravitational regime the concepts of space and time are meaningless. We study the "emergence of time" in the transition process from the noncommutative regime to the standard space-time geometry. Precise conditions are specified under which modular groups of the von Neumann algebra generated by A can be defined. These groups are interpreted as a state depending time flow. If the above conditions are further refined one obtains a state independent time flow. We show that quantum gravitational dynamics can be expressed in terms of modular groups.
Optimal Periodic Sensor Scheduling in Electronic I. Vaughan L. Clarkson
Clarkson, Vaughan
in order to minimise the intercept time with threat emitters. I. INTRODUCTION Electronic Warfare Support Measures (or Electronic Support or ES for short) can be defined as: `...that division of electronic warfare] Apart from Electronic Warfare related to communications, i.e., in non-comms EW, the emitter of interest
Multi-period optimization of pavement management systems
Yoo, Jaewook
2004-09-30T23:59:59.000Z
for the degree of DOCTOR OF PHILOSOPHY Approved as to style and content by: Alberto Garcia-Diaz (Chair of Committee) César O. Malavé....S., Hanyang University, Korea; M.S., Hanyang University, Korea Chair of Advisory Committee: Dr. Alberto Garcia-Diaz The purpose of this research is to develop a model and solution methodology for selecting and scheduling timely and cost...
Original article Behavioural features of a periodic form of massed
Paris-Sud XI, Université de
honeybee Apis dorsata G Kastberger, O Winder, T Hoetzl, G Raspotnig Department of Neurobiology, Institute by video record- ing and image analysis. Two to three times a day the nest turns from the quiescent state / orientation flight/ image analysis/ India INTRODUCTION The Asian giant honeybee Apis dorsata Fabricius, 1798
Technical Note Solution of periodic heating problems by the
Barber, James R.
, the valves of an internal combustion engine experience direct heating from the combusting gases, cooling from numerical simulation of every cycle. It also permits a direct solution for the nodal temperatures-dimensional) examples and the obvious way to proceed is to use numerical simulation [5] ± i.e., to step in time solving
A Tactical Planning Model for a Production Network with Continuous-Time Control
Graves, Stephen C.
1 A Tactical Planning Model for a Production Network with Continuous-Time Control Chee-Chong Teo1 for production planning, the time period needs to be long enough to coincide with the underlying time buckets network. Subject classifications: Inventory/production: tactical planning that considers tradeoffs between
Environment Induced Time Arrow
Janos Polonyi
2012-06-25T23:59:59.000Z
The spread of the time arrows from the environment to an observed subsystem is followed within a harmonic model. A similarity is pointed out between irreversibility and a phase with spontaneously broken symmetry. The causal structure of interaction might be lost in the irreversible case, as well. The Closed Time Path formalism is developed for classical systems and shown to handle the time arrow problem in a clear and flexible manner. The quantum case is considered, as well, and the common origin of irreversibility and decoherence is pointed out.
A. UDALSKI; M. KUBIAK; M. SZYMANSKI; J. KALUZNY; M. MATEO; W. KRZEMINSKI
1995-01-09T23:59:59.000Z
This paper is the first part of the Catalog of Periodic Variable Stars in the Galactic bulge. The Catalog is based on observations collected during the OGLE microlensing search. 213 periodic variable stars brighter than I=18 mag: 31 pulsating, 116 eclipsing and 66 miscellaneous type variables from the Baade's Window BWC field are presented. Periodic variable stars from remaining 20 fields will be presented in similar form in the next parts of the Catalog. The Catalog as well as observations of all periodic variable objects are available to astronomical community over the Internet network.
A renewal theory approach to periodic copolymers with adsorption
Francesco Caravenna; Giambattista Giacomin; Lorenzo Zambotti
2007-10-24T23:59:59.000Z
We consider a general model of a heterogeneous polymer chain fluctuating in the proximity of an interface between two selective solvents. The heterogeneous character of the model comes from the fact that the monomer units interact with the solvents and with the interface according to some charges that they carry. The charges repeat themselves along the chain in a periodic fashion. The main question concerning this model is whether the polymer remains tightly close to the interface, a phenomenon called localization, or whether there is a marked preference for one of the two solvents, thus yielding a delocalization phenomenon. In this paper, we present an approach that yields sharp estimates for the partition function of the model in all regimes (localized, delocalized and critical). This, in turn, makes possible a precise pathwise description of the polymer measure, obtaining the full scaling limits of the model. A key point is the closeness of the polymer measure to suitable Markov renewal processes, Markov renewal theory being one of the central mathematical tools of our analysis.
The periodic standing-wave approximation: post-Minkowski computation
Christopher Beetle; Benjamin Bromley; Napoleón Hernández; Richard H. Price
2007-08-08T23:59:59.000Z
The periodic standing wave method studies circular orbits of compact objects coupled to helically symmetric standing wave gravitational fields. From this solution an approximation is extracted for the strong field, slowly inspiralling motion of black holes and binary stars. Previous work on this model has dealt with nonlinear scalar models, and with linearized general relativity. Here we present the results of the method for the post-Minkowski (PM) approximation to general relativity, the first step beyond linearized gravity. We compute the PM approximation in two ways: first, via the standard approach of computing linearized gravitational fields and constructing from them quadratic driving sources for second-order fields, and second, by solving the second-order equations as an ``exact'' nonlinear system. The results of these computations have two distinct applications: (i) The computational infrastructure for the ``exact'' PM solution will be directly applicable to full general relativity. (ii) The results will allow us to begin supplying initial data to collaborators running general relativistic evolution codes.
Physics division. Progress report for period ending September 30, 1996
Ball, S.J. [ed.
1997-04-01T23:59:59.000Z
This report covers the research and development activities of the Physics Division for the 1995 and 1996 fiscal years, beginning October 1, 1994, and ending September 30, 1996. The activities of the Division continue to be concentrated in the areas of experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. In addition, there are smaller programs in plasma diagnostics and data compilation and evaluation. During the period of this report, there has been considerable success in bringing the Holifield Radioactive Ion Beam Facility (HRIBF) into routine operation. The budgets of the nuclear physics portion of the Division have increased each year in nearly all areas, and several new members have been added to the Division research and development staff. On August 30, 1996, the HRIBF successfully accelerated its first radioactive ion beams, {sup 69}As and {sup 70}As. Prior to this, the heart of the facility, the RIB injector system, was completed, including installation of a remote handling system for the target/ion source assembly. Target and ion source development is likely to be the technical key to success of the HRIBF. We have expanded our efforts in those development areas. Of special note is the development of highly permeable composite targets which have now been shown to allow release of difficult-to-produce radioactive ions such as {sup 17,18}F. A summary of the HRIBF work is provided in Chapter 1, along with supporting activities of the Joint Institute for Heavy Ion Research.
Transmissions in Graphene through Double Barriers and Periodic Potential
Miloud Mekkaoui; El Bouâzzaoui Choubabi; Ahmed Jellal; Hocine Bahlouli
2015-03-04T23:59:59.000Z
Transmission of Dirac fermions through a chip of graphene under the effect of magnetic field and a time vibrating double barrier with frequency $w$ is investigated. Quantum interference within the oscillating barrier has an important effect on quasi-particles tunneling. A combination of both a time dependent potential and a magnetic field generate physical states whose energy is double quantified by the pair of integers $(n, l)$ with high degeneracy. The large number of modes that exist in the energy spectrum presents a colossal difficulty in numerical computations. Thus we were obliged to make a truncation and limit ourselves to the central $(n = 0)$ and two adjacent side band ($n=\\pm 1$).
Madore, Barry F.; Freedman, Wendy L.; Kollmeier, Juna A.; Monson, Andy; Eric Persson, S.; Rich, Jeff A. Jr.; Scowcroft, Victoria; Seibert, Mark [Observatories of the Carnegie Institution of Washington 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Hoffman, Douglas, E-mail: barry@obs.carnegiescience.edu, E-mail: wendy@obs.carnegiescience.edu, E-mail: jak@obs.carnegiescience.edu, E-mail: amonson@obs.carnegiescience.edu, E-mail: persson@obs.carnegiescience.edu, E-mail: jrich@obs.carnegiescience.edu, E-mail: vs@obs.carnegiescience.edu, E-mail: mseibert@obs.carnegiescience.edu [Infrared Processing and Analysis Center 770 South Wilson, Pasadena, CA 91125 (United States)
2013-10-20T23:59:59.000Z
Using time-resolved, mid-infrared data from the Wide-field Infrared Survey Explorer (WISE) and geometric parallaxes from the Hubble Space Telescope for four Galactic RR Lyrae variables, we derive the following Population II period-luminosity (PL) relations for the WISE [W1], [W2], and [W3] bands at 3.4, 4.6, and 12 ?m, respectively: The slopes and the scatter around the fits are consistent with a smooth extrapolation of those same quantities from previously published K-band observations at 2.2 ?m, where the asymptotic (long-wavelength) behavior is consistent with a period-radius relation with a slope of 0.5. No obvious correlation with metallicity (spanning 0.4 dex in [Fe/H]) is found in the residuals of the four calibrating RR Lyrae stars about the mean PL regression line.
Optical and radio variability of the BL Lac object AO 0235+16: a possible 5-6 year periodicity
C. M. Raiteri; M. Villata; H. D. Aller; M. F. Aller; J. Heidt; O. M. Kurtanidze; L. Lanteri; M. Maesano; E. Massaro; F. Montagni; R. Nesci; K. Nilsson; M. G. Nikolashvili; P. Nurmi; L. Ostorero; T. Pursimo; R. Rekola; A. Sillanpaa; L. O. Takalo; H. Terasranta; G. Tosti; T. J. Balonek; M. Feldt; E. J. McGrath; A. Heines; C. Heisler; J. Hu; M. Kidger; J. R. Mattox; A. Pati; R. Robb; A. C. Sadun; P. Shastri; S. J. Wagner; J. Wei; X. Wu
2001-08-09T23:59:59.000Z
New optical and radio data on the BL Lacertae object AO 0235+16 have been collected in the last four years by a wide international collaboration, which confirm the intense activity of this source. The optical data also include the results of the Whole Earth Blazar Telescope (WEBT) first-light campaign organized in November 1997. The optical spectrum is observed to basically steepen when the source gets fainter. We have investigated the existence of typical variability time scales and of possible correlations between the optical and radio emissions by means of visual inspection, Discrete Correlation Function analysis, and Discrete Fourier Transform technique. The major radio outbursts are found to repeat quasi-regularly with a periodicity of about 5.7 years; this period is also in agreement with the occurrence of some of the major optical outbursts, but not all of them.
Incentive schemes for Internet congestion management: Raffles versus time-of-day pricing
Loiseau, Patrick
The Internet is plagued with congestion problems of growing severity which are worst at peak periods. In this paper, we compare two schemes that incentivize users to shift part of their usage from the peak-time to the ...
Analysis of MODIS 250 m NDVI Using Different Time-Series Data for Crop Type Separability
Lee, Eunmok
2014-08-31T23:59:59.000Z
The primary objectives of this research were to: (1) investigate the use of different compositing periods of NDVI values of time-series MODIS 250 m data for distinguishing major crop types on the central Great Plains of ...
McInnis, Martha Jane
1982-01-01T23:59:59.000Z
Physical manifestations of time occur in natural forms of all sizes. Architectural form serves as shelter while providing a built envelope of human life, simultaneously influencing and influenced by energetic activities ...
Center for Human Reliability Studies
2007-05-01T23:59:59.000Z
The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user
Center for Human Reliability Studies
2007-05-01T23:59:59.000Z
The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.
Developmental time windows for axon growth influence neuronal network topology
Lim, Sol
2015-01-01T23:59:59.000Z
Early brain connectivity development consists of multiple stages: birth of neurons, their migration and the subsequent growth of axons and dendrites. Each stage occurs within a certain period of time depending on types of neurons and cortical layers. Forming synapses between neurons either by growing axons starting at similar times for all neurons (much-overlapped time windows) or at different time points (less-overlapped) may affect the topological and spatial properties of neuronal networks. Here, we explore the extreme cases of axon formation especially concerning short-distance connectivity during early development, either starting at the same time for all neurons (parallel, i.e. maximally-overlapped time windows) or occurring for each neuron separately one neuron after another (serial, i.e. no overlaps in time windows). For both cases, the number of potential and established synapses remained comparable. Topological and spatial properties, however, differed: neurons that started axon growth early on in s...
Einstein@Home all-sky search for periodic gravitational waves in LIGO S5 data
Aasi, J; Abbott, B P; Abbott, R; Abbott, T D; Abernathy, M; Accadia, T; Acernese, F; Adams, C; Adams, T; Addesso, P; Adhikari, R; Affeldt, C; Agathos, M; Agatsuma, K; Ajith, P; Allen, B; Allocca, A; Ceron, E Amador; Amariutei, D; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Ast, S; Aston, S M; Astone, P; Atkinson, D; Aufmuth, P; Aulbert, C; Aylott, B E; Babak, S; Baker, P; Ballardin, G; Ballmer, S; Bao, Y; Barayoga, J C B; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Bastarrika, M; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Beck, D; Behnke, B; Bejger, M; Beker, M G; Bell, A S; Bell, C; Belopolski, I; Benacquista, M; Berliner, J M; Bertolini, A; Betzwieser, J; Beveridge, N; Beyersdorf, P T; Bhadbade, T; Bilenko, I A; Billingsley, G; Birch, J; Biswas, R; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bland, B; Blom, M; Bock, O; Bodiya, T P; Bogan, C; Bond, C; Bondarescu, R; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, S; Bosi, L; Bouhou, B; Braccini, S; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Breyer, J; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Britzger, M; Brooks, A F; Brown, D A; Bulik, T; Bulten, H J; Buonanno, A; Burguet--Castell, J; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cagnoli, G; Calloni, E; Camp, J B; Campsie, P; Cannon, K; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Caudill, S; Cavagliŕ, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chalermsongsak, T; Charlton, P; Chassande-Mottin, E; Chen, W; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chua, S S Y; Chung, C T Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J A; Clayton, J H; Cleva, F; Coccia, E; Cohadon, P -F; Colacino, C N; Colla, A; Colombini, M; Conte, A; Conte, R; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corsi, A; Costa, C A; Coughlin, M; Coulon, J -P; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Creighton, J D E; Creighton, T D; Cruise, A M; Cumming, A; Cunningham, L; Cuoco, E; Cutler, R M; Dahl, K; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Daw, E J; Day, R; Dayanga, T; De Rosa, R; DeBra, D; Debreczeni, G; Degallaix, J; Del Pozzo, W; Dent, T; Dergachev, V; DeRosa, R; Dhurandhar, S; Di Fiore, L; Di Lieto, A; Di Palma, I; Emilio, M Di Paolo; Di Virgilio, A; Díaz, M; Dietz, A; Dietz, A; Donovan, F; Dooley, K L; Doravari, S; Dorsher, S; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dumas, J -C; Dwyer, S; Eberle, T; Edgar, M; Edwards, M; Effler, A; Ehrens, P; Endr?czi, G; Engel, R; Etzel, T; Evans, K; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Farr, B F; Favata, M; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Foley, S; Forsi, E; Fotopoulos, N; Fournier, J -D; Franc, J; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, M A; Frei, Z; Freise, A; Frey, R; Fricke, T T; Friedrich, D; Fritschel, P; Frolov, V V; Fujimoto, M -K; Fulda, P J; Fyffe, M; Gair, J; Galimberti, M; Gammaitoni, L; Garcia, J; Garufi, F; Gáspár, M E; Gelencser, G; Gemme, G; Genin, E; Gennai, A; Gergely, L Á; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gil-Casanova, S; Gill, C; Gleason, J; Goetz, E; González, G; Gorodetsky, M L; Goßler, S; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Griffo, C; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gupta, R; Gustafson, E K; Gustafson, R; Hallam, J M; Hammer, D; Hammond, G; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hartman, M T; Haughian, K; Hayama, K; Hayau, J -F; Heefner, J; Heidmann, A; Heitmann, H; Hello, P; Hendry, M A; Heng, I S; Heptonstall, A W; Herrera, V; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Holtrop, M; Hong, T; Hooper, S; Hough, J; Howell, E J; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Izumi, K; Jacobson, M; James, E; Jang, Y J; Jaranowski, P; Jesse, E; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner}, J B; Kasprzack, M; Kasturi, R; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufman, K; Kawabe, K; Kawamura, S; Kawazoe, F; Keitel, D; Kelley, D; Kells, W; Keppel, D G; Keresztes, Z; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B K; Kim, C; Kim, H; Kim, K; Kim, N; Kim, Y M; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D; Kringel, V; Krishnan, B; Królak, A; Kuehn, G; Kumar, P; Kumar, R; Kurdyumov, R; Kwee, P; Lam, P K; Landry, M; Langley, A; Lantz, B
2012-01-01T23:59:59.000Z
This paper presents results of an all-sky searches for periodic gravitational waves in the frequency range [50, 1190] Hz and with frequency derivative ranges of [-2 \\times 10^-9, 1.1 \\times 10^-10] Hz/s for the fifth LIGO science run (S5). The novelty of the search lies in the use of a non-coherent technique based on the Hough-transform to combine the information from coherent searches on timescales of about one day. Because these searches are very computationally intensive, they have been deployed on the Einstein@Home distributed computing project infrastructure. The search presented here is about a factor 3 more sensitive than the previous Einstein@Home search in early S5 LIGO data. The post-processing has left us with eight surviving candidates. We show that deeper follow-up studies rule each of them out. Hence, since no statistically significant gravitational wave signals have been detected, we report upper limits on the intrinsic gravitational wave amplitude h0. For example, in the 0.5 Hz-wide band at 15...
Einstein@Home search for periodic gravitational waves in early S5 LIGO data
LIGO Scientific Collaboration
2009-05-11T23:59:59.000Z
This paper reports on an all-sky search for periodic gravitational waves from sources such as deformed isolated rapidly-spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run (S5). The data was searched for quasi-monochromatic waves with frequencies f in the range from 50 Hz to 1500 Hz, with a linear frequency drift \\dot{f} (measured at the solar system barycenter) in the range -f/\\tau < \\dot{f} < 0.1 f/\\tau, for a minimum spin-down age \\tau of 1000 years for signals below 400 Hz and 8000 years above 400 Hz. The main computational work of the search was distributed over approximately 100000 computers volunteered by the general public. This large computing power allowed the use of a relatively long coherent integration time of 30 hours while searching a large parameter space. This search extends Einstein@Home's previous search in LIGO S4 data to about three times better sensitivity. No statistically significant signals were found. In the 125 Hz to 225 Hz band, more than 90% of sources with dimensionless gravitational-wave strain tensor amplitude greater than 3e-24 would have been detected.
Einstein-Home search for periodic gravitational waves in early S5 LIGO data
Abbott, B. P.; Abbott, R.; Adhikari, R.; Anderson, S. B.; Araya, M.; Armandula, H.; Aso, Y.; Ballmer, S.; Barton, M. A.; Betzwieser, J.; Billingsley, G.; Black, E.; Blackburn, J. K.; Bork, R.; Boschi, V.; Brooks, A. F.; Cannon, K. C.; Cardenas, L.; Cepeda, C.; Chalermsongsak, T. [LIGO-California Institute of Technology, Pasadena, California 91125 (United States)] (and others)
2009-08-15T23:59:59.000Z
This paper reports on an all-sky search for periodic gravitational waves from sources such as deformed isolated rapidly spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run (S5). The data were searched for quasimonochromatic waves with frequencies f in the range from 50 to 1500 Hz, with a linear frequency drift f (measured at the solar system barycenter) in the range -f/{tau}
Searches for Time Dependent Neutrino Sources with IceCube Data from 2008 to 2012
Aartsen, M G; Adams, J; Aguilar, J A; Ahlers, M; Ahrens, M; Altmann, D; Anderson, T; Arguelles, C; Arlen, T C; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Baum, V; Bay, R; Beatty, J J; Tjus, J Becker; Becker, K -H; BenZvi, S; Berghaus, P; Berley, D; Bernardini, E; Bernhard, A; Besson, D Z; Binder, G; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Bos, F; Bose, D; Böser, S; Botner, O; Brayeur, L; Bretz, H -P; Brown, A M; Buzinsky, N; Casey, J; Casier, M; Cheung, E; Chirkin, D; Christov, A; Christy, B; Clark, K; Classen, L; Clevermann, F; Coenders, S; Cowen, D F; Silva, A H Cruz; Daughhetee, J; Davis, J C; Day, M; de André, J P A M; De Clercq, C; Dembinski, H; De Ridder, S; Desiati, P; de Vries, K D; de Wasseige, G; de With, M; DeYoung, T; D\\'\\iaz-Vélez, J C; Dumm, J P; Dunkman, M; Eagan, R; Eberhardt, B; Ehrhardt, T; Eichmann, B; Eisch, J; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feintzeig, J; Felde, J; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Frantzen, K; Fuchs, T; Gaisser, T K; Gaior, R; Gallagher, J; Gerhardt, L; Gier, D; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Golup, G; Gonzalez, J G; Goodman, J A; Góra, D; Grant, D; Gretskov, P; Groh, J C; Groß, A; Ha, C; Haack, C; Ismail, A Haj; Hallen, P; Hallgren, A; Halzen, F; Hanson, K; Hebecker, D; Heereman, D; Heinen, D; Helbing, K; Hellauer, R; Hellwig, D; Hickford, S; Hignight, J; Hill, G C; Hoffman, K D; Hoffmann, R; Homeier, A; Hoshina, K; Huang, F; Huelsnitz, W; Hulth, P O; Hultqvist, K; In, S; Ishihara, A; Jacobi, E; Jacobsen, J; Japaridze, G S; Jero, K; Jurkovic, M; Kaminsky, B; Kappes, A; Karg, T; Karle, A; Kauer, M; Keivani, A; Kelley, J L; Kheirandish, A; Kiryluk, J; Kläs, J; Klein, S R; Köhne, J -H; Kohnen, G; Kolanoski, H; Koob, A; Köpke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Kriesten, A; Krings, K; Kroll, G; Kroll, M; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Lanfranchi, J L; Larsen, D T; Larson, M J; Lesiak-Bzdak, M; Leuermann, M; Lünemann, J; Madsen, J; Maggi, G; Mahn, K B M; Maruyama, R; Mase, K; Matis, H S; Maunu, R; McNally, F; Meagher, K; Medici, M; Meli, A; Meures, T; Miarecki, S; Middell, E; Middlemas, E; Milke, N; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Niederhausen, H; Nowicki, S C; Nygren, D R; Obertacke, A; Olivas, A; Omairat, A; O'Murchadha, A; Palczewski, T; Paul, L; Penek, Ö; Pepper, J A; Heros, C Pérez de los; Pfendner, C; Pieloth, D; Pinat, E; Posselt, J; Price, P B; Przybylski, G T; Pütz, J; Quinnan, M; Rädel, L; Rameez, M; Rawlins, K; Redl, P; Rees, I; Reimann, R; Relich, M; Resconi, E; Rhode, W; Richman, M; Riedel, B; Robertson, S; Rodrigues, J P; Rongen, M; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Sander, H -G; Sandroos, J; Santander, M; Sarkar, S; Schatto, K; Scheriau, F; Schmidt, T; Schmitz, M; Schoenen, S; Schöneberg, S; Schönwald, A; Schukraft, A; Schulte, L; Schulz, O; Seckel, D; Sestayo, Y; Seunarine, S; Shanidze, R; Smith, M W E; Soldin, D; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stanisha, N A; Stasik, A; Stezelberger, T; Stokstad, R G; Stößl, A; Strahler, E A; Ström, R; Strotjohann, N L; Sullivan, G W; Sutherland, M; Taavola, H; Taboada, I; Tamburro, A; Ter-Antonyan, S; Terliuk, A; Teši?, G; Tilav, S; Toale, P A; Tobin, M N; Tosi, D; Tselengidou, M; Unger, E; Usner, M; Vallecorsa, S; van Eijndhoven, N; Vandenbroucke, J; van Santen, J; Vanheule, S; Vehring, M; Voge, M; Vraeghe, M; Walck, C; Wallraff, M; Weaver, Ch; Wellons, M; Wendt, C; Westerhoff, S; Whelan, B J; Whitehorn, N; Wichary, C; Wiebe, K; Wiebusch, C H; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, D L; Xu, X W; Xu, Y; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Ziemann, J; Zoll, M
2015-01-01T23:59:59.000Z
In this paper searches for flaring astrophysical neutrino sources and sources with periodic emission with the IceCube neutrino telescope are presented. In contrast to time integrated searches, where steady emission is assumed, the analyses presented here look for a time dependent signal of neutrinos using the information from the neutrino arrival times to enhance the discovery potential. A search was performed for correlations between neutrino arrival times and directions as well as neutrino emission following time dependent lightcurves, sporadic emission or periodicities of candidate sources. These include active galactic nuclei, soft $\\gamma$-ray repeaters, supernova remnants hosting pulsars, micro-quasars and X-ray binaries. The work presented here updates and extends previously published results to a longer period that covers four years of data from 2008 April 5 to 2012 May 16 including the first year of operation of the completed 86-string detector. The analyses did not find any significant time dependen...
Periodic solutions of even Hamiltonian systems on Thomas Bartsch & ZhiQiang Wang 1
Wang, Zhi-Qiang
Periodic solutions of even Hamiltonian systems on the torus Thomas Bartsch & ZhiQiang Wang 1 and their hospitality. #12; 2 Thomas Bartsch & ZhiQiang Wang 1 Introduction Hamiltonian systems with periodic
Geothermal R and D Project report for period April 1, 1976 to...
report for period April 1, 1976 to June 30, 1976 Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Geothermal R and D Project report for period April 1,...
The Near-infrared Period-luminosity Relations of Cepheids in the Large Magellanic Cloud
Mahzooni, Salma
2011-08-08T23:59:59.000Z
We present near-infrared (J & Ks) observations of Cepheids in the Large Magellanic Cloud. The goals of these observations are to better characterize the Cepheid Period-Luminosity relation at these wavelengths, especially for periods below 10 days...
Wave propagation and instabilities in monolithic and periodically structured elastomeric materials; revised manuscript received 3 October 2008; published 14 November 2008 Wave propagation in elastomeric states can influence wave propagation and hence interpretation of data. In the case of periodically
Victoria, University of
A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical of Mechanical Engineering) ABSTRACT Within a wave energy converter's operational bandwidth, device operation
A STUDY OF THE SHORTEST-PERIOD PLANETS FOUND WITH KEPLER
Kotson, Michael C.
We present the results of a survey aimed at discovering and studying transiting planets with orbital periods shorter than one day (ultra-short-period, or USP, planets), using data from the Kepler spacecraft. We computed ...
PERIODIC SOLUTIONS WITH NONCONSTANT SIGN IN ABEL EQUATIONS OF THE SECOND KIND
PolitĂ¨cnica de Catalunya, Universitat
PERIODIC SOLUTIONS WITH NONCONSTANT SIGN IN ABEL EQUATIONS OF THE SECOND KIND JOSEP M. OLM, XAVIER, is equivalent. Key words and phrases. Abel differential equations, periodic solutions. 1 #12;2 JOSEP M. OLM
LS Note 340 - New Design for a 27-mm Period Undulator for the...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Design for a 27-mm Period Undulator for the MBA Lattice Melike Abliz, John Grimmer, Isaac Vasserman Abstract By further optimizing the dimensions of a 27-mm period undulator's...
Taxonomy of periodic nets and the design of materials Olaf Delgado-Friedrichs,a
Yaghi, Omar M.
Taxonomy of periodic nets and the design of materials Olaf Delgado-Friedrichs,a Michael O classification (taxonomy) of polyhedra and periodic nets that is appropriate for identifying the structures
Klages, Rainer
Lyapunov instability for a periodic Lorentz gas thermostated by deterministic scattering K assess the nonlinear properties of this dynamical system by numerically calculating its Lyapunov exponents. Based on a revised method for computing Lyapunov exponents, which employs periodic
Lyapunov Modes and Time-Correlation Functions for Two-Dimensional Systems
Tooru Taniguchi; Gary P. Morriss
2005-09-27T23:59:59.000Z
The relation between the Lyapunov modes (delocalized Lyapunov vectors) and the momentum autocorrelation function is discussed in two-dimensional hard-disk systems. We show numerical evidence that the smallest time-oscillating period of the Lyapunov modes is twice as long as the time-oscillating period of momentum autocorrelation function for both square and rectangular two-dimensional systems with hard-wall boundary conditions.
RF properties of periodic accelerating structures for linear colliders
Wang, J.W.
1989-07-01T23:59:59.000Z
With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e/sup /plus//e/sup /minus// physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs.
Direct Energy Conversion Fission Reactor for the period December 1, 1999 through February 29, 2000
Brown, L.C.
2000-03-20T23:59:59.000Z
OAK B135 Direct Energy Conversion Fission Reactor for the period December 1, 1999 through February 29, 2000
DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001
L.C. BROWN
2001-09-30T23:59:59.000Z
OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001
Fabrication of 200 nm period nanomagnet arrays using interference lithography and a negative resist
Murphy, Thomas E.
period array of holes in a positive resist and electrodeposited magnetic nickel and cobalt pillars.4 We
De Pontieu, Bart [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Org. ADBS, Bldg. 252, Palo Alto, CA 94304 (United States); McIntosh, Scott W., E-mail: bdp@lmsal.co, E-mail: mscott@ucar.ed [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)
2010-10-20T23:59:59.000Z
Since the discovery of quasi-periodic propagating oscillations with periods of order 3-10 minutes in coronal loops with TRACE and SOHO/EIT (and later with STEREO/EUVI and Hinode/EIS), they have been almost universally interpreted as evidence for propagating slow-mode magnetoacoustic waves in the low plasma {beta} coronal environment. Here we show that this interpretation is not unique, and that for coronal loops associated with plage regions (as opposed to sunspots), the presence of magnetoacoustic waves may not be the only cause for the observed quasi-periodicities. We focus instead on the ubiquitous, faint upflows at 50-150 km s{sup -1} that were recently discovered as blueward asymmetries of spectral line profiles in footpoint regions of coronal loops, and as faint disturbances propagating along coronal loops in EUV/X-ray imaging time series. These faint upflows are most likely driven from below and have been associated with chromospheric jets that are (partially) rapidly heated to coronal temperatures at low heights. These two scenarios (waves versus flows) are difficult to differentiate using only imaging data, but careful analysis of spectral line profiles indicates that faint upflows are likely responsible for some of the observed quasi-periodic oscillatory signals in the corona. We show that recent EIS measurements of intensity and velocity oscillations of coronal lines (which had previously been interpreted as direct evidence for propagating waves) are actually accompanied by significant oscillations in the line width that are driven by a quasi-periodically varying component of emission in the blue wing of the line. This faint additional component of blue-shifted emission quasi-periodically modulates the peak intensity and line centroid of a single Gaussian fit to the spectral profile with the same small amplitudes (respectively a few percent of background intensity and a few km s{sup -1}) that were previously used to infer the presence of slow-mode magnetoacoustic waves. Our results indicate that it is possible that a significant fraction of the quasi-periodicities observed with coronal imagers and spectrographs that have previously been interpreted as propagating magnetoacoustic waves are instead caused by these upflows. The different physical cause for coronal oscillations would significantly impact the prospects of successful coronal seismology using propagating disturbances in coronal loops.
Hall, Rachel W.
in Hz and BPM. Is the frequency within the range of human hearing? Answer. The periodic wave frequency is 1/0.01 = 100 Hz = 6000 BPM. 2. Functions. (a) For each function, determine whether and frequency =3 BPM (2) amplitude = 10 and fundamental period = 0.005 seconds. Answer. (1) since 3 BPM = 180 Hz
Margaliot, Michael
, the biological system must entrain or phase-lock to the periodic excitation. Entrainment is also important entrain or phase-lock to the periodic excitation. In other words, in response to a periodic excitation in biological systems (sometimes called phase locking [2]) and, more generally, biological oscillators
Glass, Leon
Entrainment and termination of reentrant wave propagation in a periodically stimulated ring periodic stimulation of a class of cardiac arrhythmias caused by reentrant wave propagation in the human wave of circulation. In analogy with earlier results found from the periodic stimulation
Year Budget Period 1 5/1/2012 4/30/2013
Kay, Mark A.
/1/2014 Â 4/30/2015 Year Budget Period 4 5/1/2015 date of the budget period funded by the FY15 funds Ă? The Final Financial of the end date of the last budget period funded by the FY14 funds Ă? Departments
Nonlinear Schrödinger equation and dissipative quantum dynamics in periodic fields
Chu, Shih-I; Huang, Youhong; Hirschfelder, Joseph O.
1989-10-15T23:59:59.000Z
is found to be an attractor and g(t) exhibits a fractal-like evolution pat- tern in the course of time. The structure of the limit cycle depends strongly upon field intensity and frequency as well as the order of nonlinear multiphoton transitions. The power...) The norm of g(t) is conserved even though the system is dissipative, and (b) the following relationship holds true: d(H), = —2k((H ), —(H), ) ~0 . (6)dt Gisin has applied this formalism to spin systems in a magnetic field and to the motion of damped...
Accomplishments in Field Period Assembly for NCSX* This is how we did it
Michael Viola, J. Edwards, T. Brown, L. Dudek, R. Ellis, P. Heitzenroeder, R. Strykowsky and Michael Cole
2009-09-14T23:59:59.000Z
The National Compact Stellarator Experiment (NCSX) was a collaborative effort between ORNL and PPPL. PPPL provided the assembly techniques with guidance from ORNL to meet design criteria. The individual vacuum vessel segments, modular coils, trim coils, and toroidal field coils components were delivered to the Field Period Assembly (FPA) crew who then would complete the component assemblies and then assemble the final three field period assemblies, each consisting of two sets of three modular coils assembled over a 120o vacuum vessel segment with the trim coils and toroidal field coils providing the outer layer. The requirements for positioning the modular coils were found to be most demanding. The assembly tolerances required for accurate positioning of the field coil windings in order to generate sufficiently accurate magnetic fields strained state of the art techniques in metrology and alignment and required constant monitoring of assembly steps with laser trackers, measurement arms, and photogrammetry. The FPA activities were being performed concurrently while engineering challenges were being resolved. For example, it was determined that high friction electrically isolated shims were needed between the modular coil interface joints and low distortion welding was required in the nose region of those joints. This took months of analysis and development yet the assembly was not significantly impacted because other assembly tasks could be performed in parallel with ongoing assembly tasks as well as tasks such as advance tooling setup preparation for the eventual welding tasks. The crew technicians developed unique, accurate time saving techniques and tooling which provided significant cost and schedule savings. Project management displayed extraordinary foresight and every opportunity to gain advanced knowledge and develop techniques was taken advantage of. Despite many risk concerns, the cost and schedule performance index was maintained nearly 1.0 during the assembly phase until project cancellation. In this paper, the assembly logic, the engineering challenges, solutions to those challenges and some of the unique and clever assembly techniques, will be presented.
Nuclear Science Division: Annual report for the period October 1, 1985-September 30, 1986
Mahoney, J. (ed.)
1987-07-01T23:59:59.000Z
Research has for the most part been carried out using three local accelerators, the Bevalac, the SuperHILAC and the 88-Inch Cyclotron. However, at CERN, oxygen-16 beams were accelerated to 3.2 TeV using the LBL-GSI heavy ion injector into the CERN SPS. First results obtained during the beam test period are presented in this report. Bevalac research has probed new regions of the nuclear matter equation of state. Studies of collisions between the most massive nuclei have revealed rich new phenomena such as collective flow, where the pressures generated force the emerging particles away from the beam direction. Experiments on dileptons e/sup +/e/sup -/ pairs) utilizing the newly completed Dilepton Spectrometer (DLS) are being carried out to glean new insights into the hot, high-density stage of the collision. Major new results on the nuclear structure of exotic, very neutron-rich light nuclei are being obtained by exploiting the projectile fragmentation process to produce secondary radioactive beams. The Laboratory has proposed the Bevalac Upgrade Project to replace the Bevalac's weak-focusing synchrotron with a modern, strong-focusing synchrotron to provide higher intensity and higher quality beams. The significant enhancement of the heavy ion capability at the 88-Inch Cyclotron as a result of the recent development of the ECR source has led to a renaissance of the cyclotron as indicated by the increased demand for beam time. A variety of other scientific activities were also carried out during this period. The Isotopes Project published the first edition of a new radioactivity reference book for applied users-The Table of Radioactive Isotopes and division members organized several major scientific meetings.
Francini, Andrea
2013-05-14T23:59:59.000Z
An advance is made over the prior art in accordance with the principles of the present invention that is directed to a new approach for a system and method for a buffer management scheme called Periodic Early Discard (PED). The invention builds on the observation that, in presence of TCP traffic, the length of a queue can be stabilized by selection of an appropriate frequency for packet dropping. For any combination of number of TCP connections and distribution of the respective RTT values, there exists an ideal packet drop frequency that prevents the queue from over-flowing or under-flowing. While the value of the ideal packet drop frequency may quickly change over time and is sensitive to the series of TCP connections affected by past packet losses, and most of all is impossible to compute inline, it is possible to approximate it with a margin of error that allows keeping the queue occupancy within a pre-defined range for extended periods of time. The PED scheme aims at tracking the (unknown) ideal packet drop frequency, adjusting the approximated value based on the evolution of the queue occupancy, with corrections of the approximated packet drop frequency that occur at a timescale that is comparable to the aggregate time constant of the set of TCP connections that traverse the queue.
Linares, M.; Chakrabarty, D. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Altamirano, D. [Astronomical Institute 'Anton Pannekoek', University of Amsterdam and Center for High-Energy Astrophysics, P.O. BOX 94249, 1090 GE Amsterdam (Netherlands); Cumming, A. [Department of Physics, McGill University, 3600 Rue University, Montreal, QC H3A 2T8 (Canada); Keek, L. [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)
2012-04-01T23:59:59.000Z
We present a comprehensive study of the thermonuclear bursts and millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) transient and 11 Hz X-ray pulsar IGR J17480-2446, located in the globular cluster Terzan 5. The increase in burst rate that we found during its 2010 outburst, when persistent luminosity rose from 0.1 to 0.5 times the Eddington limit, is in qualitative agreement with thermonuclear burning theory yet contrary to all previous observations of thermonuclear bursts. Thermonuclear bursts gradually evolved into a mHz QPO when the accretion rate increased, and vice versa. The mHz QPOs from IGR J17480-2446 resemble those previously observed in other accreting NSs, yet they feature lower frequencies (by a factor {approx}3) and occur when the persistent luminosity is higher (by a factor 4-25). We find four distinct bursting regimes and a steep (close to inverse cubic) decrease of the burst recurrence time with increasing persistent luminosity. We compare these findings to nuclear burning models and find evidence for a transition between the pure helium and mixed hydrogen/helium ignition regimes when the persistent luminosity was about 0.3 times the Eddington limit. We also point out important discrepancies between the observed bursts and theory, which predicts brighter and less frequent bursts, and suggest that an additional source of heat in the NS envelope is required to reconcile the observed and expected burst properties. We discuss the impact of NS magnetic field and spin on the expected nuclear burning regimes, in the context of this particular pulsar.
Exact solution for quantum dynamics of a periodically-driven two-level-system
Anirban Gangopadhyay; Maxim Dzero; Victor Galitski
2010-05-05T23:59:59.000Z
We present a family of exact analytic solutions for non-linear quantum dynamics of a two-level system (TLS) subject to a periodic-in-time external field. In constructing the exactly solvable models, we use a "reverse engineering" approach where the form of external perturbation is chosen to preserve an integrability constraint, which yields a single non-linear differential equation for the ac-field. A solution to this equation is expressed in terms of Jacobi elliptic functions with three independent parameters that allows one to choose the frequency, average value, and amplitude of the time-dependent field at will. This form of the ac-drive is especially relevant to the problem of dynamics of TLS charge defects that cause dielectric losses in superconducting qubits. We apply our exact results to analyze non-linear dielectric response of such TLSs and show that the position of the resonance peak in the spectrum of the relevant correlation function is determined by the quantum-mechanical phase accumulated by the TLS wave-function over a time evolution cycle. It is shown that in the non-linear regime, this resonance frequency may be shifted strongly from the value predicted by the canonical TLS model. We also analyze the "spin" survival probability in the regime of strong external drive and recover a coherent destruction of tunneling phenomenon within our family of exact solutions, which manifests itself as a strong suppression of "spin-flip" processes and suggests that such non-linear dynamics in LC-resonators may lead to lower losses.
R. Staubert; S. Schandl; D. Klochkov; J Wilms; K. Postnov; N. Shakura
2007-02-20T23:59:59.000Z
We have studied the long-term (1971-2005) behaviour of the 1.24 sec pulse period and the 35 day precession period of Her X-1 and show that both periods vary in a highly correlated way (see also Staubert et al. 1997 and 2000). When the spin-up rate decreases, the 35 day turn-on period shortens.This correlation is most evident on long time scales (~2000 days),e.g.around four extended spin-down episodes, but also on shorter time scales (a few 100 days) on which quasi-periodic variations are apparent. We argue that the likely common cause is variations of the mass accretion rate onto the neutron star.The data since 1991 allow a continuous sampling and indicate a lag between the turn-on behaviour and the spin behaviour, in the sense that changes are first seen in the spin, about one cycle later in the turn-on. Both the coronal wind model (Schandl & Meyer 1994) as well as the stream-disk model (Shakura et al.999) predict this kind of behaviour.
Detection and discrimination of the periodicity of prime numbers by discrete Fourier transform
Levente Csoka
2015-01-27T23:59:59.000Z
A novel representation of a quasi-periodic modified von Mangoldt function L(n) on prime numbers and its decomposition into Fourier series has been investigated. We focus on some particular quantities characterizing the modified von Mangoldt function. The results indicate that prime number progression can be decomposed into periodic sequences. The main approach is to decompose it into sin or cosine function. Basically, it is applied to extract hidden periodicities in seemingly quasi periodic prime function. Numerical evidences were provided to confirm the periodic distribution of primes.
The Periods Discovered by RXTE in Thermonuclear Flash Bursts
T. E. Strohmayer; J. H. Swank; W. Zhang
1998-01-23T23:59:59.000Z
Oscillations in the X-ray flux of thermonuclear X-ray bursts have been observed with RXTE from at least 6 low-mass binaries, at frequencies from 330 Hz to 589 Hz. There appear to be preferred relations between the frequencies present during the bursts and those seen in the persistent flux. The amplitude of the oscillations can exceed 50 % near burst onset. Except for a systematic increase in oscillation frequency as the burst progresses, the frequency is stable. Time resolved spectra track increases in the X-ray emitting area due to propagation of the burning front over the neutron star surface, as well as radiation driven expansion of the photosphere. The neutron star mass, radius, and distance can be inferred when spectra are compared to theoretical expectations.
Marleau, Peter; Brubaker, Erik
2014-11-01T23:59:59.000Z
This report provides a short overview of the DNN R&D funded project, Time-Encoded Imagers. The project began in FY11 and concluded in FY14. The Project Description below provides the overall motivation and objectives for the project as well as a summary of programmatic direction. It is followed by a short description of each task and the resulting deliverables.
Bootstrapping Time Dilation Decoherence
Cisco Gooding; William G. Unruh
2015-03-18T23:59:59.000Z
We present a general relativistic model of a spherical shell of matter with a perfect fluid on its surface coupled to an internal oscillator, which generalizes a model recently introduced by the authors to construct a self-gravitating interferometer [1]. The internal oscillator evolution is defined with respect to the local proper time of the shell, allowing the oscillator to serve as a local clock that ticks differently depending on the shell's position and momentum. A Hamiltonian reduction is performed on the system, and an approximate quantum description is given to the reduced phase space. If we focus only on the external dynamics, we must trace out the clock degree of freedom, and this results in a form of intrinsic decoherence that shares some features with a proposed "universal" decoherence mechanism attributed to gravitational time dilation [2]. We show that the proposed decoherence remains present in the (gravity-free) limit of flat spacetime, indicating that the effect can be attributed entirely to proper time differences, and thus is not necessarily related to gravity. Finally, we point out a way to bootstrap the gravitational contribution to the time dilation decoherence by including self-interaction, and comment on how this can be considered a fundamentally gravitational intrinsic decoherence effect.
Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]
2004-10-22T23:59:59.000Z
DOE O 535.1 establishes the Department's requirements and responsibilities governing time and attendance reporting. The purpose of this revision is to reflect the transition of payroll processing from the Capital Accounting Center to the Defense Finance and Accounting System. Cancels DOE O 3600.1B. Canceled by DOE O 322.1C.
Time reversal communication system
Candy, James V. (Danville, CA); Meyer, Alan W. (Danville, CA)
2008-12-02T23:59:59.000Z
A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.
The periods of the intermediate polar RX J0153.3+7446
A. J. Norton; J. D. Tanner
2005-12-06T23:59:59.000Z
We present the first optical photometry of the counterpart to the candidate intermediate polar RX J0153.3+7446. This reveals an optical pulse period of 2333s +/- 5s. Reanalysis of the previously published ROSAT X-ray data reveals that the true X-ray pulse period is probably 1974s +/- 30s, rather than the 1414 s previously reported. Given that the previously noted orbital period of the system is 3.94 h, we are able to identify the X-ray pulse period with the white dwarf spin period and the optical pulse period with the rotation period of the white dwarf in the binary reference frame, as commonly seen in other intermediate polars. We thus confirm that RX J0153.3+7446 is indeed a typical intermediate polar.
Copyright 2002 The Financial Times Limited Financial Times (London, England)
with Argentina's capacity to abuse, manipulate, freeze, confiscate and periodically replace the national currency. Furthermore, the public will respond to red-meat populism. Argentina's need for international support in debt
Real Time Grid Reliability Management 2005
Eto, Joe; Eto, Joe; Lesieutre, Bernard; Lewis, Nancy Jo; Parashar, Manu
2008-07-07T23:59:59.000Z
The increased need to manage California?s electricity grid in real time is a result of the ongoing transition from a system operated by vertically-integrated utilities serving native loads to one operated by an independent system operator supporting competitive energy markets. During this transition period, the traditional approach to reliability management -- construction of new transmission lines -- has not been pursued due to unresolved issues related to the financing and recovery of transmission project costs. In the absence of investments in new transmission infrastructure, the best strategy for managing reliability is to equip system operators with better real-time information about actual operating margins so that they can better understand and manage the risk of operating closer to the edge. A companion strategy is to address known deficiencies in offline modeling tools that are needed to ground the use of improved real-time tools. This project: (1) developed and conducted first-ever demonstrations of two prototype real-time software tools for voltage security assessment and phasor monitoring; and (2) prepared a scoping study on improving load and generator response models. Additional funding through two separate subsequent work authorizations has already been provided to build upon the work initiated in this project.
Time-Symmetric Rolling Tachyon Profile
Matheson Longton
2015-05-04T23:59:59.000Z
We investigate the tachyon profile of a time-symmetric rolling tachyon solution to open string field theory. We algebraically construct the solution of [arXiv:0707.4472] at 6th order in the marginal parameter, and numerically evaluate the corresponding tachyon profile as well as the action and several correlation functions containing the equation of motion. We find that the marginal operator's singular self-OPE is properly regularized and all quantities we examine are finite. In contrast to the widely studied time-asymmetric case, the solution depends nontrivially on the strength of the deformation parameter. For example, we find that the number and period of oscillations of the tachyon field changes as the strength of the marginal deformation is increased. We use the recent renormalization scheme of [arXiv:1412.3466], which contains two free parameters. At finite deformation parameter the tachyon profile depends on these parameters, while when the deformation parameter is small, the solution becomes insensitive to them and behaves like previously studied time-asymmetric rolling tachyon solutions. We also show that convergence of perturbation series is not as straightforward as in the time-asymmetric case with regular OPE, and find evidence that it may depend on the renormalization constants.
Quasi-Periodic Variability in NGC 5408 X-1
Tod E. Strohmayer; Richard F. Mushotzky; Lisa Winter; Roberto Soria; Phil Uttley; Mark Cropper
2007-01-12T23:59:59.000Z
We report the discovery with XMM-Newton of quasiperiodic variability in the 0.2 - 10 keV X-ray flux from the ultraluminous X-ray source NGC 5408 X-1. The average power spectrum of all EPIC-pn data reveals a strong 20 mHz QPO with an average amplitude (rms) of 9%, and a coherence of Q~6. In a 33 ksec time interval when the 20 mHz QPO is strongest we also find evidence for a 2nd QPO peak at 15 mHz. This is the first indication for a close pair of QPOs in a ULX source. Interestingly, the frequency ratio of this QPO pair is inconsistent with 3:2 at the 3sigma level, but is consistent with a 4:3 ratio. A powerlaw noise component with slope near 1.5 is also present below 0.1 Hz with evidence for a break to a flatter slope at about 3 mHz. The source shows substantial broadband variability, with a total amplitude (rms) of about 30% in the 0.1 - 100 mHz frequency band, and there is strong energy dependence to the variability. We discuss the implications of these findings in the context of models for ULXs, and their implications for the object's mass.
Saritepe, S.; Annala, G.
1993-06-01T23:59:59.000Z
Bunched beam transfer from one accelerator to another requires coordination and synchronization of many ramped devices. During collider operation timing issues are more complicated since one has to switch from proton injection devices to antiproton injection devices. Proton and antiproton transfers are clearly distinct sequences since protons and antiprotons circulate in opposite directions in the Main Ring (MR) and in the Tevatron. The time bumps are different, the kicker firing delays are different, the kickers and lambertson magnets are different, etc. Antiprotons are too precious to be used for tuning purposes, therefore protons are transferred from the Tevatron back into the Main Ring, tracing the path of antiprotons backwards. This tuning operation is called ``reverse injection.`` Previously, the reverse injection was handled in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. Then the orbit closure was performed in the MR. In the new scheme the lambertson magnets have to be moved and separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS clock event $D8 as MRBS $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the MR. Injection devices are clock event driven. The TCLK is used as the reference clock. Certain TCLK events are triggered by the MR beam synchronized clock (MRBS) events. Some delays are measured in terms of MRBS ticks and MR revolutions. See Appendix A for a brief description of the beam synchronized clocks.
SOFT LAGS IN NEUTRON STAR kHz QUASI-PERIODIC OSCILLATIONS: EVIDENCE FOR REVERBERATION?
Barret, Didier, E-mail: didier.barret@irap.omp.eu [Universite de Toulouse, UPS-OMP, IRAP, F-31400 Toulouse (France); CNRS, Institut de Recherche en Astrophysique et Planetologie, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4 (France)
2013-06-10T23:59:59.000Z
High frequency soft reverberation lags have now been detected from stellar mass and supermassive black holes. Their interpretation involves reflection of a hard source of photons onto an accretion disk, producing a delayed reflected emission, with a time lag consistent with the light travel time between the irradiating source and the disk. Independently of the location of the clock, the kHz quasi-periodic oscillation (QPO) emission is thought to arise from the neutron star boundary layer. Here, we search for the signature of reverberation of the kHz QPO emission, by measuring the soft lags and the lag energy spectrum of the lower kHz QPOs from 4U1608-522. Soft lags, ranging from {approx}15 to {approx}40 {mu}s, between the 3-8 keV and 8-30 keV modulated emissions are detected between 565 and 890 Hz. The soft lags are not constant with frequency and show a smooth decrease between 680 Hz and 890 Hz. The broad band X-ray spectrum is modeled as the sum of a disk and a thermal Comptonized component, plus a broad iron line, expected from reflection. The spectral parameters follow a smooth relationship with the QPO frequency, in particular the fitted inner disk radius decreases steadily with frequency. Both the bump around the iron line in the lag energy spectrum and the consistency between the lag changes and the inferred changes of the inner disk radius, from either spectral fitting or the QPO frequency, suggest that the soft lags may indeed involve reverberation of the hard pulsating QPO source on the disk.
Owen D. Myers; Junru Wu; Jeffrey S. Marshall; Christopher M. Danforth
2014-09-03T23:59:59.000Z
The spatio-temporally periodic (STP) potential is interesting in Physics due to the intimate coupling between its time and spatial components. In this paper we begin with a brief discussion of the dynamical behaviors of a single particle in a STP potential and then examine the dynamics of multiple particles interacting in a STP potential via the electric Coulomb potential. For the multiple particle case, we focus on the occurrence of bifurcations when the amplitude of the STP potential varies. It is found that the particle concentration of the system plays an important role; the type of bifurcations that occur and the number of attractors present in the Poincar\\'e sections depend on whether the number of particles in the simulation is even or odd. In addition to the nonlinear dynamical approach we also discuss dependence of the squared fractional deviation of particles kinetic energy of the multiple particle system on the amplitude of the STP potential which can be used to elucidate certain transitions of states; this approach is simple and useful particularly for experimental studies of complicated interacting systems.
On the Surface Heating of Synchronously-Spinning Short-Period Jovian Planets
Andreas Burkert; Douglas Lin; Peter Bodenheimer; Chris Jones; Harold Yorke
2003-12-18T23:59:59.000Z
We consider the atmospheric flow on short-period extra-solar planets through two-dimensional numerical simulations of hydrodynamics with radiation transfer. One side is always exposed to the irradiation from the host star. The other is always in shadow. The temperature of the day side is determined by the equilibrium which the planetary atmosphere establishes with stellar radiation. Part of the thermal energy deposited on the day side is advected to the night side by a current. The radiation transfer, the night-side temperature distribution and by this the spectroscopic signature of the planet are sensitive functions of the atmospheric opacity. If the atmosphere contains grains with an abundanceand size distribution comparable to that of the interstellar medium, shallow heating occurs on the day side and the night side cools well below the day side. The temperature difference decreases as the abundance of grains is reduced. A simple analytic model of the dissipation of the circulation flow and associated kinetic heating is considered. This heating effect occurs mostly near the photosphere, not deep enough to significantly affect the size of planets. We show that the surface irradiation suppresses convection near the photospheric region on the day side. In some cases convection zones appear near the surface on the night side. This structural modification may influence the response and dissipation of tidal disturbances and alter the circularization and synchronization time scales.
Gevorg Poghosyan; Sanchit Matta; Achim Streit; Micha? Bejger; Andrzej Królak
2014-10-14T23:59:59.000Z
The parallelization, design and scalability of the \\sky code to search for periodic gravitational waves from rotating neutron stars is discussed. The code is based on an efficient implementation of the F-statistic using the Fast Fourier Transform algorithm. To perform an analysis of data from the advanced LIGO and Virgo gravitational wave detectors' network, which will start operating in 2015, hundreds of millions of CPU hours will be required - the code utilizing the potential of massively parallel supercomputers is therefore mandatory. We have parallelized the code using the Message Passing Interface standard, implemented a mechanism for combining the searches at different sky-positions and frequency bands into one extremely scalable program. The parallel I/O interface is used to escape bottlenecks, when writing the generated data into file system. This allowed to develop a highly scalable computation code, which would enable the data analysis at large scales on acceptable time scales. Benchmarking of the code on a Cray XE6 system was performed to show efficiency of our parallelization concept and to demonstrate scaling up to 50 thousand cores in parallel.
Robustness of the periodic and chaotic orientational behavior of tumbling nematic liquid crystals
Heidenreich, Sebastian; Hess, Siegfried [Institute for Theoretical Physics, Technical University Berlin, Hardenbergstrasse 36, D-10623 (Germany); Ilg, Patrick [Institute for Theoretical Physics, Technical University Berlin, Hardenbergstrasse 36, D-10623 (Germany); Universite Lyon1, Laboratoire de Physique de la Matiere Condensee et Nanostructures, CNRS, UMR5586, F-69622 Villeurbanne Cedex (France)
2006-06-15T23:59:59.000Z
The dynamical behavior of molecular alignment strongly affects physical properties of nematic liquid crystals. A theoretical description can be made by a nonlinear relaxation equation of the order parameter and leads to the prediction that rather complex even chaotic orientational behavior occur. Here the influence of fluctuating shear rates on the orientational dynamics especially on chaotic solutions is discussed. With the help of phase portraits and time evolution diagrams, we investigated the influence of different fluctuation strengths on the flow aligned, isotropic, and periodic solutions. To explore the effect of fluctuations on the chaotic behavior, we calculated the largest Lyapunov exponent for different fluctuation strengths. We found in all cases that small fluctuations of the shear rate do not affect the basic features of the dynamics of tumbling nematics. Furthermore, we present an amended potential modeling the isotropic to nematic transition and discuss the equivalence and difference to the commonly used Landau-de Gennes potential. In contrast to the Landau-de Gennes potential, our potential has the advantage to restrict the order parameter to physically admissible values. In the case of extensional flow, we show that the amended potential leads for increasing extensional rate to a better agreement with experimental results.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField8,Dist.Newof EnergyFundingGene Controls FloweringJavaGenepool Time
A Low-Cost, High-Efficiency Periodic Flow Gas Turbine for Distributed Energy Generation
Dr. Adam London
2008-06-20T23:59:59.000Z
The proposed effort served as a feasibility study for an innovative, low-cost periodic flow gas turbine capable of realizing efficiencies in the 39-48% range.
EIS-0466: Re-opening of Public Scoping Period and Announcement...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Public Scoping Meetings Continued Operation of the Sandia National Laboratories, New Mexico Comment Period Ends: 9122011 Submit Comments to: Ms. Jeanette Norte NNSA Sandia...
Measuring the rotation period distribution of field M-dwarfs with Kepler
McQuillan, Amy; Mazeh, Tsevi
2013-01-01T23:59:59.000Z
We have analysed 10 months of public data from the Kepler space mission to measure rotation periods of main-sequence stars with masses between 0.3 and 0.55 M_sun. To derive the rotational period we introduce the autocorrelation function and show that it is robust against phase and amplitude modulation and residual instrumental systematics. Of the 2483 stars examined, we detected rotation periods in 1570 (63.2%), representing an increase of a factor ~ 30 in the number of rotation period determination for field M-dwarfs. The periods range from 0.37-69.7 days, with amplitudes ranging from 1.0-140.8 mmags. The rotation period distribution is clearly bimodal, with peaks at ~ 19 and ~ 33 days, hinting at two distinct waves of star formation, a hypothesis that is supported by the fact that slower rotators tend to have larger proper motions. The two peaks of the rotation period distribution form two distinct sequences in period-temperature space, with the period decreasing with increasing temperature, reminiscent of ...
DOE Extends Comment Period on Notice of Inquiry Under the Energy...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Act of 2007, which implements the Convention on Supplementary Compensation for Nuclear Damage. The public comment period will be extended to October 27, 2010. The signed extension...
EIS-0299: Notice of Extension of Comment Period for the Environmental...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Impact Statement Proposed Production of Plutonium-238 for Use in Advanced Radioisotope Power Systems for Future Space Missions DOE is extending the public scoping period on the...
EIS-0385: Notice to Extend the Public Scoping Period and Reschedule...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
to Extend the Public Scoping Period and Reschedule Public Scoping Meetings Strategic Petroleum Reserve Due to the extraordinary circumstances created by Hurricane Katrina in the...
Bootstrapping Time Dilation Decoherence
Gooding, Cisco
2015-01-01T23:59:59.000Z
We present a general relativistic model of a spherical shell of matter with a perfect fluid on its surface coupled to an internal oscillator, which generalizes a model recently introduced by the authors to construct a self-gravitating interferometer [1]. The internal oscillator evolution is defined with respect to the local proper time of the shell, allowing the oscillator to serve as a local clock that ticks differently depending on the shell's position and momentum. A Hamiltonian reduction is performed on the system, and an approximate quantum description is given to the reduced phase space. If we focus only on the external dynamics, we must trace out the clock degree of freedom, and this results in a form of intrinsic decoherence that shares some features with a proposed "universal" decoherence mechanism attributed to gravitational time dilation [2]. We show that the proposed decoherence remains present in the (gravity-free) limit of flat spacetime, indicating that the effect can be attributed entirely to ...
Huentemeyer, Petra; Dingus, Brenda
2009-01-01T23:59:59.000Z
The High-Altitude Water Cherenkov (HAWC) Experiment is a second-generation highsensitivity gamma-ray and cosmic-ray detector that builds on the experience and technology of the Milagro observatory. Like Milagro, HAWC utilizes the water Cherenkov technique to measure extensive air showers. Instead of a pond filled with water (as in Milagro) an array of closely packed water tanks is used. The event direction will be reconstructed using the times when the PMTs in each tank are triggered. Therefore, the timing calibration will be crucial for reaching an angular resolution as low as 0.25 degrees.We propose to use a laser calibration system, patterned after the calibration system in Milagro. Like Milagro, the HAWC optical calibration system will use ~1 ns laser light pulses. Unlike Milagro, the PMTs are optically isolated and require their own optical fiber calibration. For HAWC the laser light pulses will be directed through a series of optical fan-outs and fibers to illuminate the PMTs in approximately one half o...
Final Exam Location and Time. Math 162 Fall 2001. Date: Wednesday December 12, 2001. Time: 7:00 pm -9:00 pm. Location: Lambert Fieldhouse ...
Final Exam Location and Time. Math 161 Fall 2001. Date: Friday December 14, 2001. Time: 8:00 am -10:00 am. Location: Lambert Fieldhouse ...
Combined Scheduling of Hard and Soft Real-Time Tasks in Multiprocessor Systems
Manimaran, Govindarasu
Combined Scheduling of Hard and Soft Real-Time Tasks in Multiprocessor Systems B. Duwairi and G to support combined scheduling of hard and soft real-time tasks in such systems, in which multiprocessors with periodic soft tasks. Scheduling any of these task combinations in multiprocessor systems is a #12
Task Merging for Dynamic Power Management of Cyclic Applications in Real-Time Multiprocessor Systems
Qiu, Qinru
Task Merging for Dynamic Power Management of Cyclic Applications in Real-Time Multiprocessor--In this paper we propose the method of task merging and idle period clustering for dynamic power management (DPM management, low power, multiprocessor, real-time I. INTRODUCTION Multiprocessor systems, which were used only
P-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO
P-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO by Donald-lapse seismic surveys, shot by the Reservoir Characterization Project in the fall of 2003 and 2004, at Rulison seismic can monitor tight gas reservoirs, to a limited extent, over a short period of time. Repeat surveys
Machine scheduling by column-and-row generation on the time-indexed formulation
Paris-Sud XI, Université de
-polynomial in the input size). The linear programming (LP) relaxation of this formulation is known to produce very tight this problem uses the following time-indexed Integer Programming formulation. Let a binary variable zjt, j J of constraints models the assignment of each job to a time period, while the others enforce the "one
Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients
Paris-Sud XI, Université de
Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients the heart rate variability (HRV), obtained by using the time-varying integral pulse frequency modulation (TVIPFM) which is well adapted to the exercise stress testing. We consider that the mean heart period
Lyapunov based continuous-time nonlinear controller redesign for sampled-data implementation
Nesic, Dragan
Lyapunov based continuous-time nonlinear controller redesign for sampled-data implementation, 2004 Abstract: Given a continuous-time controller and a Lyapunov function that shows global asymptotic the sampling period T) of the Lyapunov difference for the sampled-data system with the redesigned controller
Chopra, Omesh K. [Argonne National Lab., IL (United States). Environmental Science Division; Diercks, Dwight R. [Argonne National Lab., IL (United States). Nuclear Engineering Division; Ma, David Chia-Chiun [Argonne National Lab., IL (United States). Environmental Science Division; Garud, Yogendra S. [Argonne National Lab., IL (United States). Environmental Science Division
2013-12-17T23:59:59.000Z
At the request of the United States (U.S.) government, the International Atomic Energy Agency (IAEA) assembled a team of 20 senior safety experts to review the regulatory framework for the safety of operating nuclear power plants in the United States. This review focused on the effectiveness of the regulatory functions implemented by the NRC and on its commitment to nuclear safety and continuous improvement. One suggestion resulting from that review was that the U.S. Nuclear Regulatory Commission (NRC) incorporate lessons learned from periodic safety reviews (PSRs) performed in other countries as an input to the NRC’s assessment processes. In the U.S., commercial nuclear power plants (NPPs) are granted an initial 40-year operating license, which may be renewed for additional 20-year periods, subject to complying with regulatory requirements. The NRC has established a framework through its inspection, and operational experience processes to ensure the safe operation of licensed nuclear facilities on an ongoing basis. In contrast, most other countries do not impose a specific time limit on the operating licenses for NPPs, they instead require that the utility operating the plant perform PSRs, typically at approximately 10-year intervals, to assure continued safe operation until the next assessment. The staff contracted with Argonne National Laboratory (Argonne) to perform a pilot review of selected translated PSR assessment reports and related documentation from foreign nuclear regulatory authorities to identify any potential new regulatory insights regarding license renewal-related topics and NPP operating experience (OpE). A total of 14 PSR assessment documents from 9 countries were reviewed. For all of the countries except France, individual reports were provided for each of the plants reviewed. In the case of France, three reports were provided that reviewed the performance assessment of thirty-four 900-MWe reactors of similar design commissioned between 1978 and 1988. All of the reports reviewed were the regulator’s assessment of the PSR findings rather than the original PSR report, and all but one were English translations from the original language. In these reviews, it was found that most of the countries base their regulatory guidance to some extent (and often to a large extent) on U.S. design codes and standards, NRC regulatory guidance, and U.S. industry guidance. In addition, many of the observed operational technical issues and OpE events reported for U.S. reactors are also cited in the PSR reports. The PSR reports also identified a number of potential technical material/component performance issues and OpE events that are not commonly reported for U.S. plants.
The backward phase flow method for the Eulerian finite time Lyapunov exponent computations
Leung, Shingyu, E-mail: masyleung@ust.hk [Department of Mathematics, Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)] [Department of Mathematics, Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)
2013-12-15T23:59:59.000Z
We propose a simple Eulerian approach to compute the moderate to long time flow map for approximating the Lyapunov exponent of a (periodic or aperiodic) dynamical system. The idea is to generalize a recently proposed backward phase flow method which is specially designed for long time level set propagation. Unlike the original phase flow method or the backward phase flow method, which is applicable only to autonomous systems, the current approach can also be applied to any time-dependent (periodic or aperiodic) flow. We will discuss the stability of the proposed method. Numerical examples will be given to demonstrate the effectiveness of the algorithm.
Finite-difference time-domain simulation of fusion plasmas at radiofrequency time scales
Smithe, David N. [Tech-X Corporation, 5621 Arapahoe Avenue, Suite A, Boulder, Colorado 80303 (United States)
2007-05-15T23:59:59.000Z
Simulation of dense plasmas in the radiofrequency range are typically performed in the frequency domain, i.e., by solving Laplace-transformed Maxwell's equations. This technique is well-suited for the study of linear heating and quasilinear evolution, but does not generalize well to the study of nonlinear phenomena. Conversely, time-domain simulation in this range is difficult because the time scale is long compared to the electron plasma wave period, and in addition, the various cutoff and resonance behaviors within the plasma insure that any explicit finite-difference scheme would be numerically unstable. To resolve this dilemma, explicit finite-difference Maxwell terms are maintained, but a carefully time-centered locally implicit method is introduced to treat the plasma current, such that all linear plasma dispersion behavior is faithfully reproduced at the available temporal and spatial resolution, despite the fact that the simulation time step may exceed the electron gyro and electron plasma time scales by orders of magnitude. Demonstrations are presented of the method for several classical benchmarks, including mode conversion to ion cyclotron wave, cyclotron resonance, propagation into a plasma-wave cutoff, and tunneling through low-density edge plasma.
Singh, Nishant K
2015-01-01T23:59:59.000Z
We study the dynamics of stellar wind from one of the bodies in the binary system, where the other body interacts only gravitationally. We focus on following three issues: (i) we explore the origin of observed periodic variations in maser intensity; (ii) we address the nature of bipolar molecular outflows; and (iii) we show generation of baroclinicity in the same model setup. From direct numerical simulations and further numerical modelling, we find that the maser intensity along a given line of sight varies periodically due to periodic modulation of material density. This modulation period is of the order of the binary period. Another feature of this model is that the velocity structure of the flow remains unchanged with time in late stages of wind evolution. Therefore the location of the masing spot along the chosen sightline stays at the same spatial location, thus naturally explaining the observational fact. This also gives an appearance of bipolar nature in the standard position-velocity diagram, as has ...
Deciding Timed Bisimulation for Timed Automata Using Zone Valuation Graph
Prasad, Sanjiva
Deciding Timed Bisimulation for Timed Automata Using Zone Valuation Graph Shibashis Guha, Chinmay was first proved to be decidable for timed automata by Cerans using a product construction method on region graph. Several other methods have been proposed in the literature since then for decid- ing timed
Cook, C.; Dibrani, B.; Richmond, M.; Bleich, M.; Titzler, P..; Fu, T. [Pacific Northwest National Laboratory
2006-01-01T23:59:59.000Z
This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10 C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir's epilimnion at the Clearwater/Snake River confluence is of key biological importance. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four reservoirs are also heavily influenced by wind forcing at the water's surface and during periods of low river discharge often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The thickness (depth) of this upper warm layer and its direction of travel may be of key biological importance to juvenile fall Chinook salmon. This report describes field data collection, modeling, and analysis of hydrodynamic and temperature conditions in the Lower Granite Reservoir during the summer flow augmentation periods of 2002, 2003, and 2004. Although temperature, and hence density, differences during flow augmentation periods between the Clearwater and Snake rivers were approximately equal (7-12 C) for all four years, the discharge ratio varied which resulted in significant differences in entrainment of cooler Clearwater River water into the Lower Granite Reservoir epilimnion. However, as a direct result of system management, Lower Granite Dam tailrace temperatures were maintained near 20 C during all years. Primary differences in the other three lower Snake River reservoirs were therefore a result of meteorological conditions and dam operations, which produced variations in wind setup and surface heating. Circulation patterns in all four lower Snake River reservoirs were numerically simulated for periods of 2002, 2003, 2004, and 2005 using CE-QUAL-W2. Simulation results show that these models are capable of matching diurnal and long-term temperature and velocity changes in the reservoirs. In addition, the confluence zone of the Clearwater and Snake rivers was modeled using the three-dimensional non-hydrostatic model Flow3D. Once calibrated and validated, the reservoir models were used to investigate downstream impacts of alternative reservoir operation schemes, such as increasing or decreasing the ratio of Clearwater to Snake river discharge. Simulation results were linked with the particle tracking model FINS to develop reservoir-integrated metrics that varied due to these alternative operation schemes. Findings indicate that significant alterations in water temperature throughout the lower Snake River are possible by altering hypolimnetic discharges from Dworshak Reservoir, which may also impact the behavior of migrating juvenile fall Chinook salmon during periods of flow augmentation.
Time encoded radiation imaging
Marleau, Peter; Brubaker, Erik; Kiff, Scott
2014-10-21T23:59:59.000Z
The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.
Real time automated inspection
Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.
1985-05-21T23:59:59.000Z
A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.
Real time automated inspection
Fant, Karl M. (Minneapolis, MN); Fundakowski, Richard A. (Saint Paul, MN); Levitt, Tod S. (Minneapolis, MN); Overland, John E. (Plymouth, MN); Suresh, Bindinganavle R. (New Brighton, MN); Ulrich, Franz W. (Minneapolis, MN)
1985-01-01T23:59:59.000Z
A method and apparatus relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges are segmented out by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections.
A LPV approach to control and real-time scheduling codesign: application to a robot-arm control
Paris-Sud XI, Université de
resource sharing between control tasks according to the controlled plant per- formances. Here the varying] a processor load regulation is proposed and applied for real-time control of a robot arm. In [3], some results the sampling period may also be parameter varying. Finally methods to design sampling period dependent con
Time-Multiplexed Measurements of Nonclassical Light at Telecom Wavelengths
G. Harder; C. Silberhorn; J. Rehacek; Z. Hradil; L. Motka; B. Stoklasa; L. L. Sanchez-Soto
2014-06-13T23:59:59.000Z
We report the experimental reconstruction of the statistical properties of an ultrafast pulsed type-II parametric down conversion source in a periodically poled KTP waveguide at telecom wavelengths, with almost perfect photon-number correlations. We used a photon-number-resolving time-multiplexed detector based on a fiber-optical setup and a pair of avalanche photodiodes. By resorting to a germane data-pattern tomography, we assess the properties of the nonclassical light states states with unprecedented precision.
Approximations to wave propagation through doubly-periodic arrays of scatterers
Approximations to wave propagation through doubly-periodic arrays of scatterers P. Mc Abstract The propagation of waves through a doubly-periodic array of identical rigid scatterers of matched asymptotic expansions is used to obtain the dispersion relation corresponding to wave propagation
Periodic Cooling of Bird Eggs Reduces Embryonic Growth Efficiency Christopher R. Olson*
Vleck, Carol
927 Periodic Cooling of Bird Eggs Reduces Embryonic Growth Efficiency Christopher R. Olson* Carol M, periodic cooling occurs when the in- cubating adult leaves the nest to forage, but the effects of pe- riodic cooling on embryo growth, yolk use, and metabolism are poorly known. To address this question, we
Stable all-optical limiting in nonlinear periodic structures. I. Analysis
Pelinovsky, Dmitry
Stable all-optical limiting in nonlinear periodic structures. I. Analysis Dmitry Pelinovsky consider propagation of coherent light through a nonlinear periodic optical structure consisting of two al-dependent dy- namics. We find the domain for existence of true all-optical limiting when the input
Multi-Period Production Capacity Planning for Integrated Product and Production System Design*
Saitou, Kazuhiro "Kazu"
Multi-Period Production Capacity Planning for Integrated Product and Production System Design* Emre.ac.uk kazu@umich.edu .Abstract This paper presents a simulation-based method to aid multi-period production capacity planning by quantifying the trade-off between product quality and production cost. The product
Covariation of coastal water temperature and microbial pollution at interannual to tidal periods
Winant, Clinton D.
Covariation of coastal water temperature and microbial pollution at interannual to tidal periods, California, USA Daniel B. Lluch-Cota Centro de Investigaciones Biologicas del Noroeste, La Paz, Mexico-period cooling are coincident with elevated levels of microbial pollution in the surf zone. This relationship can
Instability inside a rotating gas cylinder subject to axial periodic strain Y. Duguet,a
Paris-Sud XI, UniversitĂ© de
of viscous flow inside a closed circular cylinder rotating about its axis, periodically compressed by meansInstability inside a rotating gas cylinder subject to axial periodic strain Y. Duguet,a J. F. Scott are known to support inertial oscillations whose frequencies are less than twice the basic rotation rate.1
Commensurability effects induced by a periodic array of nanoscale anti-dots in Nb superconductor
Metlushko, Vitali
Commensurability effects induced by a periodic array of nanoscale anti-dots in Nb superconductor A. PACS: 74.25.Ha; 74.76.)w Keywords: Nanostructures; Anti-dots; Commensurability 1. Introduction atomic layers on periodical substrate [5], magnetic bubble arrays [6] and the magnetically induced Wigner
Operator Non-Availability Periods N. Brauner, G. Finke, V. Lehoux-Lebacque, C. Rapine
Paris-Sud XI, Université de
Operator Non-Availability Periods N. Brauner, G. Finke, V. Lehoux-Lebacque, C. Rapine C. Potts, V. Strusevich July 27, 2007 version-3 Abstract. In scheduling literature, the notion of machine non-availability special periods (the week-ends, holidays, vacations) where the chemists are not available. However, human
Evolution of obesity prevalence in France: An Age-Period-Cohort analysis
Evolution of obesity prevalence in France: An Age-Period- Cohort analysis Authors : Ibrahima Diouf1, France. Running title: Age-Period-Cohort analysis for obesity prevalence in France Address in the prevalence of obesity has been reported in France since 1990. We investigated the impact of birth cohort
Guide to Library Resources for English 110 Finding Books, Periodicals, Microforms and Media
Cakoni, Fioralba
the Library of Congress Classification System. Each book (or bound volume of a periodical) is assigned a call1 Guide to Library Resources for English 110 Finding Books, Periodicals, Microforms and Media held by the University of Delaware Library, you may wish to start by searching DELCAT or WorldCat Local
ON THE EXISTENCE OF STEADY PERIODIC CAPILLARY-GRAVITY STRATIFIED WATER WAVES
points for steady water waves. The condition which ensures the lack of stagnation points for 1991ON THE EXISTENCE OF STEADY PERIODIC CAPILLARY-GRAVITY STRATIFIED WATER WAVES DAVID HENRY AND BOGDANVASILE MATIOC Abstract. We prove the existence of small steady periodic capillary-gravity water waves
Ungerleider, Leslie G.
Program Director/Principal Investigator (Last, First, Middle): DETAILED BUDGET FOR INITIAL BUDGET SUBTOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD (Item 7a, Face Page) $ CONSORTIUM/CONTRACTUAL COSTS FACILITIES AND ADMINISTRATIVE COSTS TOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD $ PHS 398 (Rev. 6/09) Page
Baker, Chris I.
Program Director/Principal Investigator (Last, First, Middle): DETAILED BUDGET FOR INITIAL BUDGET SUBTOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD (Item 7a, Face Page) $ CONSORTIUM/CONTRACTUAL COSTS FACILITIES AND ADMINISTRATIVE COSTS TOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD $ Page Form Page 4 PHS 398
Harris, David T. (David Taylor)
2011-01-01T23:59:59.000Z
Most animals pass through a series of juvenile stages on their way from embryo to adult. These stages represent periods of time in which stage-specific developmental processes occur. At the end of development, the organism ...
Flash Memory Garbage Collection in Hard Real-Time Systems
Lai, Chien-An
2012-10-19T23:59:59.000Z
collection and compare it to that of more proactive schemes. I develop formulas to assess the schedulability of hard real- time periodic task sets under simpli ed memory consumption models. Results show that I prove the proactive schemes achieve the larger... work in the area of ash memory management. Moreover, we review the previous research about garbage collection in real-time system. In Chapter III we will describe a simpli ed ash memory model that will be used throughout the rest of the thesis...
Formisano, V.; Orsini, S.; Bonifazi, C.; Egidi, A.; Moreno, G.
1980-05-01T23:59:59.000Z
The interaction of the solar wind with ions backstreaming from the earth's bow shock is studied at high time resolution. It turns out that the bulk velocity of the solar wind oscillates, both in magnitude and direction, with typical periods of approx.1 minute in presence of the 'diffuse' ion population. Oscillations of comparable periods are also observed in the angular distribution and energy spectrum of the diffuse ions.
Rothe, R.E.
1996-09-30T23:59:59.000Z
A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution`s concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the `Poisoned Tube Tank` because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service.
Schneider, Abe
2014-04-09T23:59:59.000Z
The main goal of this proposal was to develop and test a novel powertrain solution for the SLH hydroEngine?, a low-cost, efficient low-head hydropower technology. Nearly two-thirds of U.S. renewable electricity is produced by hydropower (EIA 2010). According to the U.S. Department of Energy; this amount could be increased by 50% with small hydropower plants, often using already-existing dams (Hall 2004). There are more than 80,000 existing dams, and of these, less than 4% generate power (Blankinship 2009). In addition, there are over 800 irrigation districts in the U.S., many with multiple, non-power, low-head drops. These existing, non-power dams and irrigation drops could be retrofitted to produce distributed, baseload, renewable energy with appropriate technology. The problem is that most existing dams are low-head, or less than 30 feet in height (Ragon 2009). Only about 2% of the available low-head hydropower resource in the U.S. has been developed, leaving more than 70 GW of annual mean potential low-head capacity untapped (Hall 2004). Natel Energy, Inc. is developing a low-head hydropower turbine that operates efficiently at heads less than 6 meters and is cost-effective for deployment across multiple low-head structures. Because of the unique racetrack-like path taken by the prime-movers in the SLH, a flexible powertrain is required. Historically, the only viable technological solution was roller chain. Despite the having the ability to easily attach blades, roller chain is characterized by significant drawbacks, including high cost, wear, and vibration from chordal action. Advanced carbon-#12;fiber-reinforced timing belts have been recently developed which, coupled with a novel belt attachment system developed by Natel Energy, result in a large reduction in moving parts, reduced mass and cost, and elimination of chordal action for increased fatigue life. The work done in this project affirmatively addressed each of the following 3 major uncertainties concerning a timing-belt based hydroEngine ?powertrain: 1. Can a belt handle the high torques and power loads demanded by the SLH? (Yes.) 2. Can the SLH blades be mounted to belt with a connection that can withstand the loads encountered in operation? (Yes.) 3. Can the belt, with blade attachments, live through the required cyclic loading? (Yes.) The research adds to the general understanding of sustainable small hydropower systems by using innovative system testing to develop and demonstrate performance of a novel powertrain solution, enabling a new type of hydroelectric turbine to be commercially developed. The technical effectiveness of the methods investigated has been shown to be positive through an extensive design and testing process accommodating many constraints and goals, with a major emphasis on high cycle fatigue life. Economic feasibility of the innovations has been demonstrated through many iterations of design for manufacturability and cost reduction. The project is of benefit to the public because it has helped to develop a solution to a major problem -- despite the large available potential for new low-head hydropower, high capital costs and high levelized cost of electricity (LCOE) continue to be major barriers to project development. The hydroEngine? represents a significant innovation, leveraging novel fluid mechanics and mechanical configuration to allow lower-cost turbine manufacture and development of low head hydropower resources.
Time Domain Partitioning of Electricity Production Cost Simulations
Barrows, C.; Hummon, M.; Jones, W.; Hale, E.
2014-01-01T23:59:59.000Z
Production cost models are often used for planning by simulating power system operations over long time horizons. The simulation of a day-ahead energy market can take several weeks to compute. Tractability improvements are often made through model simplifications, such as: reductions in transmission modeling detail, relaxation of commitment variable integrality, reductions in cost modeling detail, etc. One common simplification is to partition the simulation horizon so that weekly or monthly horizons can be simulated in parallel. However, horizon partitions are often executed with overlap periods of arbitrary and sometimes zero length. We calculate the time domain persistence of historical unit commitment decisions to inform time domain partitioning of production cost models. The results are implemented using PLEXOS production cost modeling software in an HPC environment to improve the computation time of simulations while maintaining solution integrity.
Energy Conversion of Fully Random Thermal Relaxation Times
François Barriquand
2005-07-26T23:59:59.000Z
Thermodynamic random processes in thermal systems are generally associated with one or several relaxation times, the inverse of which are formally homogeneous with energy. Here, we show in a precise way that the periodic modification of relaxation times during temperature-constant thermodynamic cycles can be thermodynamically beneficiary to the operator. This result holds as long as the operator who adjusts relaxation times does not attempt to control the randomness associated with relaxation times itself as a Maxwell 'demon' would do. Indirectly, our result also shows that thermal randomness appears satisfactorily described within a conventional quantum-statistical framework, and that the attempts advocated notably by Ilya Prigogine to go beyond a Hilbert space description of quantum statistics do not seem justified - at least according to the present state of our knowledge. Fundamental interpretation of randomness, either thermal or quantum mechanical, is briefly discussed.
Aagaard, B T; Graves, R W; Rodgers, A; Brocher, T M; Simpson, R W; Dreger, D; Petersson, N A; Larsen, S C; Ma, S; Jachens, R C
2009-11-04T23:59:59.000Z
We simulate long-period (T > 1.0-2.0 s) and broadband (T > 0.1 s) ground motions for 39 scenarios earthquakes (Mw 6.7-7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions compared with neglecting the influence of creep. Nevertheless, the scenario earthquakes generate strong shaking throughout the San Francisco Bay area with about 50% of the urban area experiencing MMI VII or greater for the magnitude 7.0 scenario events. Long-period simulations of the 2007 Mw 4.18 Oakland and 2007 Mw 4.5 Alum Rock earthquakes show that the USGS Bay Area Velocity Model version 08.3.0 permits simulation of the amplitude and duration of shaking throughout the San Francisco Bay area, with the greatest accuracy in the Santa Clara Valley (San Jose area). The ground motions exhibit a strong sensitivity to the rupture length (or magnitude), hypocenter (or rupture directivity), and slip distribution. The ground motions display a much weaker sensitivity to the rise time and rupture speed. Peak velocities, peak accelerations, and spectral accelerations from the synthetic broadband ground motions are, on average, slightly higher than the Next Generation Attenuation (NGA) ground-motion prediction equations. We attribute at least some of this difference to the relatively narrow width of the Hayward fault ruptures. The simulations suggest that the Spudich and Chiou (2008) directivity corrections to the NGA relations could be improved by including a dependence on the rupture speed and increasing the areal extent of rupture directivity with period. The simulations also indicate that the NGA relations may under-predict amplification in shallow sedimentary basins.
A real-time intercepting beam-profile monitor for a medical cyclotron
Hendriks, C.; Uittenbosch, T.; Cameron, D.; Kellogg, S.; Gray, D.; Buckley, K.; Schaffer, P.; Verzilov, V.; Hoehr, C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada)] [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada)
2013-11-15T23:59:59.000Z
There is a lack of real-time continuous beam-diagnostic tools for medical cyclotrons due to high power deposition during proton irradiation. To overcome this limitation, we have developed a profile monitor that is capable of providing continuous feedback about beam shape and current in real time while it is inserted in the beam path. This enables users to optimize the beam profile and observe fluctuations in the beam over time with periodic insertion of the monitor.
Propagation of travelling waves in sub-excitable systems driven by noise and periodic forcing
Fen-Ni Si; Quan-Xing Liu; Jin-Zhong Zhang; Lu-Qun Zhou
2007-11-23T23:59:59.000Z
It has been reported that traveling waves propagate periodically and stably in sub-excitable systems driven by noise [Phys. Rev. Lett. \\textbf{88}, 138301 (2002)]. As a further investigation, here we observe different types of traveling waves under different noises and periodic forces, using a simplified Oregonator model. Depending on different noises and periodic forces, we have observed different types of wave propagation (or their disappearance). Moreover, the reversal phenomena are observed in this system based on the numerical experiments in the one-dimensional space. As an explanation, we regard it as the effect of periodic forces. Thus, we give qualitative explanations to how reversal phenomena stably appear, which seem to arise from the mixing function of the periodic force and the noise. And the output period and three velocities (the normal, the positive and the negative) of the travelling waves are defined and their relationship with the periodic forces, along with the types of waves, are also studied in sub-excitable system under a fixed noise intensity.
Formation of laser-induced periodic surface structures on niobium by femtosecond laser irradiation
Pan, A.; Dias, A.; Gomez-Aranzadi, M.; Olaizola, S. M. [CIC microGUNE, Goiru Kalea 9 Polo Innovación Garaia, 20500 Arrasate-Mondragón (Spain); CEIT-IK4 and Tecnun, University of Navarra, Manuel Lardizábal 15, 20018 San Sebastián (Spain); Rodriguez, A. [CIC microGUNE, Goiru Kalea 9 Polo Innovación Garaia, 20500 Arrasate-Mondragón (Spain)
2014-05-07T23:59:59.000Z
The surface morphology of a Niobium sample, irradiated in air by a femtosecond laser with a wavelength of 800?nm and pulse duration of 100 fs, was examined. The period of the micro/nanostructures, parallel and perpendicularly oriented to the linearly polarized fs-laser beam, was studied by means of 2D Fast Fourier Transform analysis. The observed Laser-Induced Periodic Surface Structures (LIPSS) were classified as Low Spatial Frequency LIPSS (periods about 600?nm) and High Spatial Frequency LIPSS, showing a periodicity around 300?nm, both of them perpendicularly oriented to the polarization of the incident laser wave. Moreover, parallel high spatial frequency LIPSS were observed with periods around 100?nm located at the peripheral areas of the laser fingerprint and overwritten on the perpendicular periodic gratings. The results indicate that this method of micro/nanostructuring allows controlling the Niobium grating period by the number of pulses applied, so the scan speed and not the fluence is the key parameter of control. A discussion on the mechanism of the surface topology evolution was also introduced.
The Lyapunov function for Schrödinger operators with a periodic 2x2 matrix potential
Andrei Badanin; Jochen Brüning; Evgeny Korotyaev
2005-08-29T23:59:59.000Z
We consider the Schr\\"odinger operator on the real line with a 2x2 matrix valued 1-periodic potential. The spectrum of this operator is absolutely continuous and consists of intervals separated by gaps. We define a Lyapunov function which is analytic on a two sheeted Riemann surface. On each sheet, the Lyapunov function has the same properties as in the scalar case, but it has branch points, which we call resonances. We prove the existence of real as well as non-real resonances for specific potentials. We determine the asymptotics of the periodic and anti-periodic spectrum and of the resonances at high energy. We show that there exist two type of gaps: 1) stable gaps, where the endpoints are periodic and anti-periodic eigenvalues, 2) unstable (resonance) gaps, where the endpoints are resonances (i.e., real branch points of the Lyapunov function). We also show that periodic and anti-periodic spectrum together determine the spectrum of the matrix Hill operator.
Turbo Space-Time Codes with Time Varying Linear Transformations
Haimovich, Alexander
1 Turbo Space-Time Codes with Time Varying Linear Transformations Hangjun Chen and Alexander 07102 Email: {hangjun.chen; alexander.m.haimovich}@njit.edu Abstract Turbo space-time codes with symbols in this paper. It is shown that turbo codes with TVLT achieve full diversity gain and do not require exhaustive
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MARVELS-1b: A Short-Period, Brown Dwarf Desert Candidate from the SDSS-III MARVELS Planet Search
Lee, Brian L; Fleming, Scott W; Stassun, Keivan G; Gaudi, B Scott; Barnes, Rory; Mahadevan, Suvrath; Eastman, Jason D; Wright, Jason; Siverd, Robert J; Gary, Bruce; Ghezzi, Luan; Laws, Chris; Wisniewski, John P; de Mello, G F Porto; Ogando, Ricardo L C; Maia, Marcio A G; da Costa, Luiz Nicolaci; Sivarani, Thirupathi; Pepper, Joshua; Nguyen, Duy Cuong; Hebb, Leslie; De Lee, Nathan; Wang, Ji; Wan, Xiaoke; Zhao, Bo; Chang, Liang; Groot, John; Varosi, Frank; Hearty, Fred; Hanna, Kevin; van Eyken, J C; Kane, Stephen R; Agol, Eric; Bizyaev, Dmitry; Bochanski, John J; Brewington, Howard; Chen, Zhiping; Costello, Erin; Dou, Liming; Eisenstein, Daniel J; Fletcher, Adam; Ford, Eric B; Guo, Pengcheng; Holtzman, Jon A; Jiang, Peng; Leger, R French; Liu, Jian; Long, Daniel C; Malanushenko, Elena; Malanushenko, Viktor; Malik, Mohit; Oravetz, Daniel; Pan, Kaike; Rohan, Pais; Schneider, Donald P; Shelden, Alaina; Snedden, Stephanie A; Simmons, Audrey; Weaver, B A; Weinberg, David H; Xie, Ji-Wei
2010-01-01T23:59:59.000Z
We present a new short-period brown dwarf candidate around the star TYC 1240-00945-1. This candidate was discovered in the first year of the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the third phase of the Sloan Digital Sky Survey (SDSS-III), and we designate the brown dwarf as MARVELS-1b. MARVELS uses the technique of dispersed fixed-delay interferometery to simultaneously obtain radial velocity measurements for 60 objects per field using a single, custom-built instrument that is fiber fed from the SDSS 2.5-m telescope. From our 20 radial velocity measurements spread over a ~370 d time baseline, we derive a Keplerian orbital fit with semi-amplitude K=2.533+/-0.025 km/s, period P=5.8953+/-0.0004 d, and eccentricity consistent with circular. Independent follow-up radial velocity data confirm the orbit. Adopting a mass of 1.37+/-0.11 M_Sun for the slightly evolved F9 host star, we infer that the companion has a minimum mass of 28.0+/-1.5 M_Jup, a semimajor axis 0....
Bonnet-Bidaud, J M; Busschaert, C; Falize, E; Michaut, C
2015-01-01T23:59:59.000Z
Quasi-periodic oscillations (QPOs) are observed in the optical flux of some polars with typical periods of 1 to 3 s but none have been observed yet in X-rays where a significant part of the accreting energy is released. QPOs are expected and predicted from shock oscillations. Most of the polars have been observed by the XMM-Newton satellite. We made use of the homogeneous set of observations of the polars by XMM-Newton to search for the presence of QPOs in the (0.5-10 keV) energy range and to set significant upper limits for the brightest X-ray polars. We extracted high time-resolution X-ray light curves by taking advantage of the 0.07 sec resolution of the EPIC-PN camera. Among the 65 polars observed with XMM-Newton from 1998 to 2012, a sample of 24 sources was selected on the basis of their counting rate in the PN instrument to secure significant limits. We searched for QPOs using Fast Fourier Transform (FFT) methods and defined limits of detection using statistical tools. Among the sample surveyed, none sh...
Cooperative accumulation of coherent undulator radiation emitted from periodic electron bunches
Seo, Y. H. [Department of Electrophysics, Kwangwoon University, Seoul 139-701 (Korea, Republic of)
2013-01-15T23:59:59.000Z
Cavity build-up of coherent undulator synchrotron radiation emitted by periodic electron bunches is investigated. At the optimal off-grazing resonance, the bunch slippage relative to the radiation pulse introduces an initial transient period during which radiation accumulates cooperatively as if it is emitted by a single bunch. The power growth during the period is quadratic to the number of bunches. The number of cooperative bunches is {approx}2 Script-Small-L {sub s}{sup 2}, where Script-Small-L {sub s} denotes the slippage length in units of the resonant wavelength.
Galuzio, P. P.; Lopes, S. R.; Viana, R. L. [Departamento de Fisica, Universidade Federal do Parana, Caixa Postal 19044, 81531-990 Curitiba, Parana (Brazil)
2011-11-15T23:59:59.000Z
Certain high-dimensional dynamical systems present two or more attractors characterized by different energy branches. For some parameter values the dynamics oscillates between these two branches in a seemingly random fashion, a phenomenon called two-state on-off intermittency. In this work we show that the dynamical mechanism underlying this intermittency involves the severe breakdown of hyperbolicity of the attractors through a mechanism known as unstable dimension variability. We characterize the parametric evolution of this variability using statistical properties of the finite-time Lyapunov exponents. As a model system that exhibits this behavior we consider periodically forced and damped drift waves. In this spatiotemporal example there is a low-dimensional chaotic attractor that is created by an interior crisis, already presenting unstable dimension variability.
WAVELETS WITH RIDGES: A HIGH-RESOLUTION REPRESENTATION OF CATACLYSMIC VARIABLE TIME SERIES
Blackman, Claire, E-mail: claire.blackman@rhul.ac.u [Department of Economics, Royal Holloway, University of London, Egham, Surrey TW20 0EX (United Kingdom)
2010-11-15T23:59:59.000Z
Quasi-periodic oscillations (QPO) and dwarf nova oscillations (DNOs) occur in dwarf novae and nova-like variables during outburst and occasionally during quiescence, and have analogs in high-mass X-ray binaries and black-hole candidates. The frequent low coherence of quasi-period oscillations and DNOs can make detection with standard time-series tools such as periodograms problematic. This paper develops tools to analyze quasi-periodic brightness oscillations. We review the use of time-frequency representations (TFRs) in the astronomical literature, and show that representations such as the Choi-Williams distribution and Zhao-Atlas-Marks representation, which are best suited to high signal-to-noise data, cannot be assumed a priori to be the best techniques for our data, which have a much higher noise level and lower coherence. This leads us to a detailed analysis of the time-frequency resolution and statistical properties of six TFRs. We conclude that the wavelet scalogram, with the addition of wavelet ridges and maxima points, is the most effective TFR for analyzing quasi-periodicities in low signal-to-noise data, as it has high time-frequency resolution, and is a minimum variance estimator. We use the wavelet ridges method to re-analyze archival data from VW Hyi, and find 62 new QPOs and 7 new long-period DNOs. Relative to previous analyses, our method substantially improves the detection rate for QPOs.
Nemat-Nasser, Sia
Homogenized dynamic constitutive relation for Bloch-wave propagation in periodic composites composites has been made only very recently. Here we discuss the explicit form of the effective dynamic properties of composites with tailored microstructure necessitates a systematic homogenization procedure
Use and Finance BiAnnual Reporting Form Reporting Period: July 2013 through December 2013
Papalambros, Panos
Use and Finance BiAnnual Reporting Form Reporting Period: July 2013 through December 2013 $ Other (Professional Fees, Telecommunications, Moving) 538,200$ Other (Finance resources services center will be established for finance and human resources transaction processing activities
Dental analysis of Classic period population variability in the Maya area
Scherer, Andrew Kenneth
2005-02-17T23:59:59.000Z
In this dissertation I examine population history and structure in the Maya area during the Classic period (A.D. 250-900). Within the Maya area, archaeologists have identified regional variation in material culture between ...
Effect of availability on multi-period planning of subsea oil and gas production systems
Ruiz Vasquez, Karla Liliana
2009-05-15T23:59:59.000Z
subsea equipment downtime of approximately 7%. As a result, new production planning is accomplished in the effective work period, which will be beneficial in financial risk decisions such as a government’s deliverability contracts....
Periodicity in Class II methanol masers in high mass star forming regions
Goedhart, S; Gaylard, M J; van der Walt, D J
2013-01-01T23:59:59.000Z
We report the results of 10 years of monitoring of six regularly varying 6.7 GHz methanol masers using the Hartebeesthoek 26m telescope. Observations were done at intervals of 1--2 weeks, with faster sampling during flaring episodes. Four of the sources were also monitored at 12.2 GHz and show correlated variations. We find the Lomb-Scargle periodogram to be the most sensitive method to search for periodicity but possibly prone to false detections. Periods range from 132.8 days (with 26 cycles observed) to 509 days (with 7 cycles observed). Five of the sources show arguably periodic variations, while G331.13-0.24 shows strong periodicity in one peak, with large and variable delays in other peaks.
Skinner, L.; McCave, I. N.; Carter, L.; Fallon, S.; Scrivner, A. E.; Primeau, F.
2014-12-15T23:59:59.000Z
It has been proposed that the ventilation of the deep Pacific carbon pool was not significantly reduced during the last glacial period, posing a problem for canonical theories of glacial–interglacial CO2 change. However, using radiocarbon dates...
The effect of disorder on the wave propagation in one-dimensional periodic optical systems
Yuri A. Godin; Stanislav Molchanov; Boris Vainberg
2011-10-18T23:59:59.000Z
The influence of disorder on the transmission through periodic waveguides is studied. Using a canonical form of the transfer matrix we investigate dependence of the Lyapunov exponent $\\gamma$ on the frequency $\
Simulation of adiabatic thermal beams in a periodic solenoidal magnetic focusing field
Barton, T. J.
Self-consistent particle-in-cell simulations are performed to verify earlier theoretical predictions of adiabatic thermal beams in a periodic solenoidal magnetic focusing field [ K.?R. Samokhvalova, J. Zhou and C. Chen ...
Periodic orbit bifurcations as an ionization mechanism: The bichromatically driven hydrogen atom
S. Huang; C. Chandre; T. Uzer
2007-12-17T23:59:59.000Z
We investigate the multiphoton ionization of hydrogen driven by a strong bichromatic microwave field. In a regime where classical and quantum simulations agree, periodic orbit analysis captures the mechanism: Through the linear stability of periodic orbits we match qualitatively the variation of experimental ionization rates with control parameters such as the amplitudes of the two modes of the field or their relative phases. Moreover, we discuss an empirical formula which reproduces quantum simulations to a high degree of accuracy. This quantitative agreement shows the mechanism by which short periodic orbits organize the dynamics in multiphoton ionization. We also analyze the effect of longer pulse durations. Finally we compare our results with those based on the peak amplitude rule. Both qualitative and quantitative analyses are implemented for different mode locked fields. In parameter space, the localization of the period doubling and halving allows one to predict the set of parameters (amplitudes and phase lag) where ionization occurs.
Einstein@Home search for periodic gravitational waves in LIGO S4 data
Zucker, Michael E.
A search for periodic gravitational waves, from sources such as isolated rapidly spinning neutron stars, was carried out using 510 h of data from the fourth LIGO science run (S4). The search was for quasimonochromatic waves ...
Einstein@Home search for periodic gravitational waves in early S5 LIGO data
Barsotti, Lisa
This paper reports on an all-sky search for periodic gravitational waves from sources such as deformed isolated rapidly spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run ...
CO2 Abatement in the UK Power Sector: Evidence from the EU ETS Trial Period
Ellerman, A. Denny
2008-01-01T23:59:59.000Z
This paper provides an empirical assessment of CO2 emissions abatement in the UK power sector during the trial period of the EU ETS. Using an econometrically estimated model of fuel switching, it separates the impacts of ...
Enhanced radiation tolerance in nitride multilayered nanofilms with small period-thicknesses
Hong Mengqing; Ren Feng; Zhang Hongxiu; Xiao Xiangheng; Tian Canxin; Fu Dejun; Jiang Changzhong [School of Physics and Technology and Center for Electron Microscopy, Wuhan University, Wuhan 430072 (China); Yang Bing [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Wang Yongqiang [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2012-10-08T23:59:59.000Z
This paper demonstrates a substantial enhancement in radiation tolerance for small period-thickness of CrN/AlTiN multilayered nanofilms. CrN/AlTiN multilayered nanofilms with period-thicknesses of 3, 5, 7, and 9 nm were irradiated by 190 keV Ar{sup +} ions to fluences ranging from 1 to 5 Multiplication-Sign 10{sup 16} ions/cm{sup 2}. Nanofilm with 3 nm period-thickness begins to be amorphized under 5 Multiplication-Sign 10{sup 16} ions/cm{sup 2}, while those with larger period-thicknesses are amorphized under 3 Multiplication-Sign 10{sup 16} ions/cm{sup 2}. Our results show that multilayered ceramic nanofilms are potential radiation tolerant materials with good properties. The interfaces in the multilayered nanofilms act as good sinks to absorb the radiation-induced defects.
Effective slip boundary conditions for arbitrary periodic surfaces: the surface mobility tensor
Kamrin, Kenneth N.
In a variety of applications, most notably microfluidics design, slip-based boundary conditions have been sought to characterize fluid flow over patterned surfaces. We focus on laminar shear flows over surfaces with periodic ...
Exhibition of the periodicity of Quantum Fourier Transformation in Nuclear Magnetic Resonance
Xinhua Peng; Xiwen Zhu; Ximing Fang; Mang Feng; Xiaodong Yang; Maili Liu; Kelin Gao
2002-02-01T23:59:59.000Z
The remarkable capability of quantum Fourier transformation (QFT) to extract the periodicity of a given periodic function has been exhibited by using nuclear magnetic resonance (NMR) techniques. Two separate sets of experiments were performed. In a full QFT, the periodicity were validated with state tomography and fidelity measurements. For a simplified QFT, the three-qubit pseudo-pure state was created by introducting an additional observer spin, and the spectra recorded on the observer spin showed intuitively the power of QFT\\ to find the periodicity. Experimentally realizing the QFT provides a critical step to implement the renowned Shor's quantum factoring algorithm and many other algorithms. Moveover, it can be applied to the study of quantum chaos and other quantum information processing.
Exhibition of the periodicity of Quantum Fourier Transformation in Nuclear Magnetic Resonance
Peng, X; Fang, X; Feng, M; Yang, X; Liu, M; Gao, K; Peng, Xinhua; Zhu, Xiwen; Fang, Ximing; Feng, Mang; Yang, Xiaodong; Liu, Maili; Gao, Kelin
2002-01-01T23:59:59.000Z
The remarkable capability of quantum Fourier transformation (QFT) to extract the periodicity of a given periodic function has been exhibited by using nuclear magnetic resonance (NMR) techniques. Two separate sets of experiments were performed. In a full QFT, the periodicity were validated with state tomography and fidelity measurements. For a simplified QFT, the three-qubit pseudo-pure state was created by introducting an additional observer spin, and the spectra recorded on the observer spin showed intuitively the power of QFT\\ to find the periodicity. Experimentally realizing the QFT provides a critical step to implement the renowned Shor's quantum factoring algorithm and many other algorithms. Moveover, it can be applied to the study of quantum chaos and other quantum information processing.
Brolo, Alexandre G.
;evaluation as chemical sensors and a brief comparison of the pPeriodic Metallic Nanostructures as Plasmonic Chemical Sensors Chiara Valsecchi and Alexandre G generation of low- cost and efficient chemical sensors and biosensors. The extensive variety
Fejer, Martin M.
- conversion interactions.2 5 There have been several reports that periodically poled lithium niobate (PPLN s is a parameter that depends on the properties of the host crystal, donors, and traps and nd is the dark
McLaren, Brian L. (Brian Lloyd), 1958-
2001-01-01T23:59:59.000Z
This dissertation examines the intersection of the modern and the colonial in architecture and culture during the period of Italian colonization of North Africa from 1911 to 1943. Rather than see the colonies as merely a ...
Semiclassical analysis for a Schrodinger operator with a U(2) artificial gauge: the periodic case
Paris-Sud XI, UniversitĂ© de
: semiclassical asymptotic, spectrum, eigenvalues, Schrodinger, periodic potential, BKW method, width of the first Preliminary: the artificial gauge model 3 3 Proof of Theorem 2.1 5 4 Asymptotic of the first band 6 5 B.K.W
Semiclassical analysis for a Schrodinger operator with a U(2) artificial gauge: the periodic case
Paris-Sud XI, UniversitĂ© de
: semiclassical asymptotic, spectrum, eigenvalues, Schrodinger, periodic potential, BKW method, width of the first Preliminary: the artificial gauge model 3 3 Proof of Theorem 2.1 5 4 Asymptotic of the first band 7 5 B.K.W
Public Comment Period for Portsmouth Site D&D and Waste Disposition...
Office of Environmental Management (EM)
2014 8:00AM EST to March 11, 2015 5:00PM EDT Public Comment Period for the Process Buildings and Complex Facilities Decontamination and Decommissioning and Site-Wide Waste...
Wright, Angela Shanna
2004-01-01T23:59:59.000Z
A study was done to investigate and better understand dietary modifications of canine lipid metabolism during gestation, lactation, and the neonatal period. Sexually intact, clinically normal female dogs were bred to the same sire and divided...
Spatial Periodic Forcing Can Displace Patterns It Is Intended to Control
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Mau, Yair; Hagberg, Aric; Meron, Ehud
2012-07-01T23:59:59.000Z
Spatial periodic forcing of pattern-forming systems is an important, but lightly studied, method of controlling patterns. It can be used to control the amplitude and wave number of one-dimensional periodic patterns, to stabilize unstable patterns, and to induce them below instability onset. We show that, although in one spatial dimension the forcing acts to reinforce the patterns, in two dimensions it acts to destabilize or displace them by inducing two-dimensional rectangular and oblique patterns.
Effect of the hepatoma growth period on host plasma and liver lipid concentrations
Matocha, Martha Frances
1979-01-01T23:59:59.000Z
EFFECT OF THE HEPATOMA GROWTH PERIOD ON HOST PLASMA AND LIVER LIPID CONCENTRATIONS A Thesis by MARTHA FRANCES MATOCHA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE August 1979 Niajor Sub ect: Biochem. 'stry EFFECT OF THE HEPATOMA GROWTH PERIOD ON HOST PLASMA AND LIVER LIPID CONCENTRATIONS A Thesis MARTHA FRANCES MATOCHA Approved as to style and content by: (Chairman of Committee) (Mern...
Dusatko, John; Allison, S.; Browne, M.; Krejcik, P.; /SLAC
2012-07-23T23:59:59.000Z
The Linac Coherent Light Source requires precision timing trigger signals for various accelerator diagnostics and controls at SLAC-NAL. A new timing system has been developed that meets these requirements. This system is based on COTS hardware with a mixture of custom-designed units. An added challenge has been the requirement that the LCLS Timing System must co-exist and 'know' about the existing SLC Timing System. This paper describes the architecture, construction and performance of the LCLS timing event system.
On the spin period distribution in Be/X-ray binaries
Cheng, Z.-Q.; Shao, Y.; Li, X.-D., E-mail: lixd@nju.edu.cn [Department of Astronomy, Nanjing University, Nanjing 210093 (China)
2014-05-10T23:59:59.000Z
There is a remarkable correlation between the spin periods of the accreting neutron stars (NSs) in Be/X-ray binaries (BeXBs) and their orbital periods. Recently, Knigge et al. showed that the distribution of the spin periods contains two distinct subpopulations peaked at ?10 s and ?200 s, respectively, and suggested that they may be related to two types of supernovae for the formation of the NSs, i.e., core-collapse and electron-capture supernovae. Here we propose that the bimodal spin period distribution is likely to be ascribed to different accretion modes of the NSs in BeXBs. When the NS tends to capture material from the warped, outer part of the Be star disk and experiences giant outbursts, a radiatively cooling dominated disk is formed around the NS, which spins up the NS and is responsible for the short-period subpopulation. In BeXBs that are dominated by normal outbursts or are persistent, the accretion flow is advection-dominated or quasi-spherical. The spin-up process is accordingly inefficient, leading to longer periods of the neuron stars. The potential relation between the subpopulations and the supernova mechanism is also discussed.
The High Time Resolution Universe Survey VI: An Artificial Neural Network and Timing of 75 Pulsars
Bates, S D; Barsdell, B R; Bhat, N D R; Burgay, M; Burke-Spolaor, S; Champion, D J; Coster, P; D'Amico, N; Jameson, A; Johnston, S; Keith, M J; Kramer, M; Levin, L; Lyne, A; Milia, S; Ng, C; Nietner, C; Possenti, A; Stappers, B; Thornton, D; van Straten, W
2012-01-01T23:59:59.000Z
We present 75 pulsars discovered in the mid-latitude portion of the High Time Resolution Universe survey, 54 of which have full timing solutions. All the pulsars have spin periods greater than 100 ms, and none of those with timing solutions are in binaries. Two display particularly interesting behaviour; PSR J1054-5944 is found to be an intermittent pulsar, and PSR J1809-0119 has glitched twice since its discovery. In the second half of the paper we discuss the development and application of an artificial neural network in the data-processing pipeline for the survey. We discuss the tests that were used to generate scores and find that our neural network was able to reject over 99% of the candidates produced in the data processing, and able to blindly detect 85% of pulsars. We suggest that improvements to the accuracy should be possible if further care is taken when training an artificial neural network; for example ensuring that a representative sample of the pulsar population is used during the training proc...
Timing Calibration in PET Using a Time Alignment Probe
Moses, William W.; Thompson, Christopher J.
2006-01-01T23:59:59.000Z
when the two sets of calibration factors are loaded into theare equivalent. Inde, .er/#—calibration, positron emissionB. Conventional Time-Delay Calibration Method 4> >,? '- -'#$
Chimera and globally clustered chimera: Impact of time delay
Sheeba, Jane H; Lakshmanan, M
2010-01-01T23:59:59.000Z
Following a short report of our preliminary results [Phys. Rev. E 79, 055203(R) (2009)], we present a more detailed study of the effects of coupling delay in diffusively coupled phase oscillator populations. We find that coupling delay induces chimera and globally clustered chimera (GCC) states in delay coupled populations. We show the existence of multi-clustered states that act as link between the chimera and the GCC states. A stable GCC state goes through a variety of GCC states, namely periodic, aperiodic, long-- and short--period breathers and becomes unstable GCC leading to global synchronization in the system, on increasing time delay. We provide numerical evidence and theoretical explanations for the above results and discuss possible applications of the observed phenomena.
Development of Advanced Concept for Shortening Construction Period of ABWR Plant
Hiroshi Ijichi; Toshio Yamashita; Masahiro Tsutagawa; Hiroya Mori [Toshiba Corporation (Japan); Nobuaki Ooshima; Jun Miura [Hitachi Ltd. (Japan); Minoru Kanechika [Kajima Corporation (Japan); Nobuaki Miura [Shimizu Corporation (Japan)
2002-07-01T23:59:59.000Z
Construction of a nuclear power plant (NPP) requires a very long period because of large amount of construction materials and many issues for negotiation among multiple sections. Shortening the construction period advances the date of return on an investment, and can also result in reduced construction cost. Therefore, the study of this subject has a very high priority for utilities. We achieved a construction period of 37 months from the first concrete work to fuel loading (F/L) (51.5 months from the inspection of the foundation (I/F) to the start of commercial operation (C/O)) at the Kashiwazaki-Kariwa NPPs No. 6 and 7 (KK-6/7), which are the first ABWR plants in the world. At TEPCO's next plant, we think that a construction period of less than 36 months (45 months from I/F to C/O) can be realized based on conventional methods such as early start of equipment installation and blocking of equipment to be brought in advance. Furthermore, we are studying the feasibility of a 21.5-month construction period (30 months from I/F to C/O) with advanced ideas and methods. The important concepts for a 21.5-month construction period are adoption of a new building structure that is the steel plate reinforced concrete (SC) structure and promotion of extensive modularization of equipment and building structure. With introducing these new concepts, we are planning the master schedule (M/S) and finding solutions to conflicts in the schedule of area release from building construction work to equipment installation work (schedule-conflicts.) In this report, we present the shortest construction period and an effective method to put it into practice for the conventional general arrangement (GA) of ABWR. In the future, we will continue the study on the improvement of building configuration and arrangements, and make clear of the concept for large composite modules of building structures and equipment. (authors)
THE SPECTROSCOPIC SIGNATURE OF QUASI-PERIODIC UPFLOWS IN ACTIVE REGION TIMESERIES
Tian Hui; McIntosh, Scott W. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 8037 (United States); De Pontieu, Bart, E-mail: htian@ucar.edu, E-mail: mscott@ucar.edu, E-mail: bdp@lmsal.com [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Org. ADBS, Bldg. 252, Palo Alto, CA 94304 (United States)
2011-02-01T23:59:59.000Z
Quasi-periodic propagating disturbances are frequently observed in coronal intensity image sequences. These disturbances have historically been interpreted as being the signature of slow-mode magnetoacoustic waves propagating into the corona. The detailed analysis of Hinode EUV Imaging Spectrometer (EIS) timeseries observations of an active region (known to contain propagating disturbances) shows strongly correlated, quasi-periodic, oscillations in intensity, Doppler shift, and line width. No frequency doubling is visible in the latter. The enhancements in the moments of the line profile are generally accompanied by a faint, quasi-periodically occurring, excess emission at {approx}100 km s{sup -1} in the blue wing of coronal emission lines. The correspondence of quasi-periodic excess wing emission and the moments of the line profile indicates that repetitive high-velocity upflows are responsible for the oscillatory behavior observed. Furthermore, we show that the same quasi-periodic upflows can be directly identified in a simultaneous image sequence obtained by the Hinode X-Ray Telescope. These results are consistent with the recent assertion of De Pontieu and McIntosh that the wave interpretation of the data is not unique. Indeed, given that several instances are seen to propagate along the direction of the EIS slit that clearly shows in-phase, quasi-periodic variations of intensity, velocity, width (without frequency doubling), and blue wing enhanced emission, this data set would appear to provide a compelling example that upflows are more likely to be the main cause of the quasi-periodicities observed here, as such correspondences are hard to reconcile in the wave paradigm.
Nova DAQ, System Architecture, Data Combiner and Timing System
Biery, K.A.; Cooper, R.G.; Foulkes, S.C.; Guglielmo, G.M.; Haynes, B.W.; Kwarciany, R.; Pavlicek, F.V.; Piccoli, L.P.; Votava, M.E.V.; /Fermilab
2007-04-01T23:59:59.000Z
NOvA (E929) is a long baseline experiment that will search for neutrino oscillations. There will be one detector near the beam source at Fermilab, and one detector in northern Minnesota. The DAQ system for the far detector collects over-threshold hits from over 450,000 channels of scintillator readouts, sorts the time-stamped data packets and archives selected time periods of data for transmission and processing. While a simple point-to-point protocol is used for the first level of data collection, Ethernet was chosen as the fabric for the rest of the DAQ. The packet time-stamp and overall system synchronization is based on two common-view GPS trained clock oscillators, one at each site. The present design cost-effectively satisfies the experiment's moderate speed and data volume requirements.
Reactor control rod timing system
Wu, Peter T. K. (Clifton Park, NY)
1982-01-01T23:59:59.000Z
A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.
Reactor control rod timing system
Wu, P.T.
1982-02-09T23:59:59.000Z
A fluid driven jet-edge whistle timing system for control rods of a nuclear reactor for producing real-time detection of the timing of each control rod in its scram operation. An important parameter in reactor safety, particularly for liquid metal fast breeder reactors (LMFBR), is the time deviation between the time the control rod is released and the time the rod actually reaches the down position. The whistle has a nearly pure tone signal with center frequency (Above 100 kHz) far above the frequency band in which the energy of the background noise is concentrated. Each control rod can be fitted with a whistle with a different frequency so that there is no ambiguity in differentiating the signal from each control rod.
ExperTime: Tracking Expertise over Time Norwegian University of
Nřrvĺg, Kjetil
ExperTime: Tracking Expertise over Time Jan Rybak Norwegian University of Science and Technology Norwegian University of Science and Technology kjetil.norvag@idi.ntnu.no ABSTRACT This paper presents Exper 611, 2014, Gold Coast, Queensland, Australia. ACM 978-1-4503-2257-7/14/07. http://dx.doi.org/10
IT'S ABOUT TIME Characteristic times in biogeochemistry and climate
Schwartz, Stephen E.
, and then It falls to earth: Can you tell me when? Decision making on energy and climate change #12;Impulse responseIT'S ABOUT TIME Characteristic times in biogeochemistry and climate Stephen E. Schwartz Symposium on biogeochemical cycling and climate In honor of Henning Rodhe on the occasion of his retirement from the chair
Real-Time Control with Parametric Timed Reachability Games
Boyer, Edmond
for which the existence of a parameter valuation, such that there is a strategy for the controller to reach set of parameter valuations. Keywords: Timed automata, game theory, parameters, control, verification, model-checking 1. INTRODUCTION Formal methods are widely used in the analysis of time critical systems
Copyright 2005 The Financial Times Limited Financial Times (London, England)
Copyright 2005 The Financial Times Limited Financial Times (London, England) July 11, 2005 Monday London Edition 1 SECTION: COMMENT; Pg. 19 LENGTH: 922 words HEADLINE: Hope and generosity can triumph, nudged the world closer to this prospect. With the backdrop of the bombs in London, the Gleneagles
Time Structure of Muonic Showers
L. Cazon; R. A. Vazquez; A. A. Watson; E. Zas
2003-11-10T23:59:59.000Z
An analytical description of the time structure of the pulses induced by muons in air showers at ground level is deduced assuming the production distance distribution for the muons can be obtained elsewhere. The results of this description are compared against those obtained from simulated showers using AIRES. Major contributions to muon time delays are identified and a relation between the time structure and the depth distribution is unveiled.
Quantum Gravity, the Origin of Time and Time's Arrow
J. W. Moffat
1992-09-02T23:59:59.000Z
The local Lorentz and diffeomorphism symmetries of Einstein's gravitational theory are spontaneously broken by a Higgs mechanism by invoking a phase transition in the early Universe, at a critical temperature $T_c$ below which the symmetry is restored. The spontaneous breakdown of the vacuum state generates an external time and the wave function of the Universe satisfies a time dependent Schrodinger equation, which reduces to the Wheeler-deWitt equation in the classical regime for $T T_c$ and matter is created fractions of seconds after the big bang, generating the matter in the Universe. The time direction of the vacuum expectation value of the scalar Higgs field generates a time asymmetry, which defines the cosmological arrow of time and the direction of increasing entropy as the Lorentz symmetry is restored at low temperatures.
Subsystem real-time Time Dependent Density Functional Theory
Krishtal, Alisa; Pavanello, Michele
2015-01-01T23:59:59.000Z
We present the extension of Frozen Density Embedding (FDE) theory to real-time Time Dependent Density Functional Theory (rt-TDDFT). FDE a is DFT-in-DFT embedding method that allows to partition a larger Kohn-Sham system into a set of smaller, coupled Kohn-Sham systems. Additional to the computational advantage, FDE provides physical insight into the properties of embedded systems and the coupling interactions between them. The extension to rt-TDDFT is done straightforwardly by evolving the Kohn-Sham subsystems in time simultaneously, while updating the embedding potential between the systems at every time step. Two main applications are presented: the explicit excitation energy transfer in real time between subsystems is demonstrated for the case of the Na$_4$ cluster and the effect of the embedding on optical spectra of coupled chromophores. In particular, the importance of including the full dynamic response in the embedding potential is demonstrated.
Resource Allocation with Time Intervals
2009-09-21T23:59:59.000Z
Keywords: resource allocation, proper intervals, unsplittable flow ... be positioned within a larger time interval) and call admission control, see [4] and [8] for ...
Periodic auroral forms and geomagnetic field oscillations in the 1400 MLT region
Potemra, T.A. (Johns Hopkins Univ., Laurel, MD (United States)); Vo, H.; Venkatesan, D.; Cogger, L.L. (Univ. of Calgary, Alberta (Canada)); Erlandson, R.E.; Zanetti, L.J.; Bythrow, P.F.; Anderson, B.J. (Johns Hopkins Univ., Laurel, MD (United States))
1990-05-01T23:59:59.000Z
The UV images obtained with the Viking satellite often show bright features which resemble beads or pearls aligned in the east-west direction between noon and 1800 MLT. Viking acquired a series of 25 UV images during a 28-min period on July 29, 1986, which showed a distinct series of periodic bright features in this region. Magnetic field and hot plasma measurements obtained by Viking confirm that the UV emissions are colocated with the field line projection of an upward-flowing region 1 Birkeland current and precipitating energetic ({approximately}200 eV) electrons. The magnetic field and electric field measurements show transverse oscillations with a nearly constant period of about 3.5 min from 67{degree} invariant latitude equatorward up to the location of the large-scale Birkeland current system near 76{degree} invariant latitude. The electric field oscillations lead the magnetic field oscillations by about a quarter-period. The authors interpret the observed oscillations as standing Alfven waves driven at a frequency near the local resonance frequency by a large-scale wave in the boundary layer. They propose that the energy flux of the precipitating low-energy electrons in this afternoon region is modulated by this boundary wave and produces the periodic UV emission features. The results of this study support the view that large-scale oscillations of magnetospheric boundaries, possibly associated with the Kelvin-Helmholtz instability, can modulate currents, particles, and auroral forms.