Powered by Deep Web Technologies
Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Time and Frequency Portal  

Science Conference Proceedings (OSTI)

NIST Home > Time and Frequency Portal. Time and Frequency Portal. Programs and Projects. CODATA values of the fundamental constants ...

2013-06-27T23:59:59.000Z

2

Time and Frequency Division Homepage  

Science Conference Proceedings (OSTI)

... Controlled ClocksTelephone TimeDivision HistoryFrequently Asked Questions (FAQ)Time and Frequency from A to Z: An illustrated glossaryA Walk ...

2013-12-27T23:59:59.000Z

3

FREQUENCY AND TIME  

Science Conference Proceedings (OSTI)

... STRATWARM observed and FLARES expected ... observed and PROTON FLARE expected (- - ) STRATWARM ... time of observed solar or geophysical ...

2003-01-30T23:59:59.000Z

4

Climatological Time Series with Periodic Correlation  

Science Conference Proceedings (OSTI)

Many climatological time series display a periodic correlation structure. This paper examines three issues encountered when analyzing such time series: detection of periodic correlation, modeling periodic correlation, and trend estimation under ...

Robert Lund; Harry Hurd; Peter Bloomfield; Richard Smith

1995-11-01T23:59:59.000Z

5

General Interest NIST Time and Frequency Publications  

Science Conference Proceedings (OSTI)

... Time and Frequency Users Manual A detailed ... Fundamentals of Time and Frequency An overview of ... Lombardi, The Mechatronics Handbook, 2001. ...

2012-01-31T23:59:59.000Z

6

Time and Frequency from A to Z: Index  

Science Conference Proceedings (OSTI)

... Time Codes; Jitter; Julian Day; Kilohertz (kHz); Laser Cooling; Leap Day; ... Passive Frequency Standard; Path Delay; Period; Phase; Phase Comparison ...

2010-10-05T23:59:59.000Z

7

Property:TimePeriod | Open Energy Information  

Open Energy Info (EERE)

TimePeriod TimePeriod Jump to: navigation, search This is a property of type String. Pages using the property "TimePeriod" Showing 25 pages using this property. (previous 25) (next 25) 0 0.4 kV remote control (Smart Grid Project) + Not available + 2 220 kV SSSC device for power flow control (Smart Grid Project) + Jul 2009 Jul 2014 + A A complete and normalized 61850 substation (Smart Grid Project) + Oct 2009 Dec 2015 + ADELE Project AACAES (Smart Grid Project) + Dec 2009 Dec 2013 + AFTER A Framework for electrical power sysTems vulnerability identification, dEfense and Restoration (Smart Grid Project) + 2011-2014 + AFTER A Framework for electrical power sysTems vulnerability identification, dEfense and Restoration (Smart Grid Project) (Belgium) + 2011-2014 +

8

Time-Varying z-Transform for the Analysis of Discrete-Time Linear Time Periodic Systems  

Science Conference Proceedings (OSTI)

This article deals with a new representation of linear discrete-time periodic systems. This representation, based on the time-varying z-transform, turns out to be highly efficient in the field of automatic control, when an appropriate choice of ... Keywords: Nyquist criterion, final value theorem, initial value theorem, linear discrete-time periodic systems, time-varying z-transform, time-varying frequency response, time-varying systems

A. Garcia Iturricha; J. Sabatier; A. Oustaloup

2003-07-01T23:59:59.000Z

9

Time and Frequency Users Manual  

Science Conference Proceedings (OSTI)

... 9 TERMS USED 11 ... 135 GLOSSARY 137 INDEX ... The OIL INDUSTRY needs accurate timing to help automate oil well drilling, especially offshore. ...

2002-01-02T23:59:59.000Z

10

SIM Time and Frequency Working Group  

Science Conference Proceedings (OSTI)

... SIM Time and Frequency Metrology Course at INTI. Buenos Aires, Argentina (February 4th through February 7th, 2008). Schedule in PDF format. ...

11

SIM Time and Frequency Working Group  

Science Conference Proceedings (OSTI)

... file). Schedule and Slides from Time and Frequency Metrology Course in Buenos Aires, Argentina (2/4/08 to 02/07/08). Schedule ...

12

Particle energization through time-periodic helical magnetic fields  

E-Print Network (OSTI)

We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with $A=B=C=1$ are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late time with positive Lyapunov exponent. We further show that in time-periodic (frequency $\\omega$) ABC fields the kinetic energy of a charged particle can increase indefinitely with time. At late times the mean kinetic energy grows as a power law in time with exponent $\\xi$ that approaches unity. For an initial distribution of particles, whose kinetic energy is uniformly distributed within some interval, the PDF of kinetic energy is, at late time, close to a Gaussian but with steeper tails.

Dhrubaditya Mitra; Axel Brandenburg; Brahmananda Dasgupta; Eyvind Niklasson; Abhay Ram

2013-06-01T23:59:59.000Z

13

Transmission thresholds in time-periodically driven nonlinear disordered systems  

E-Print Network (OSTI)

We study energy propagation in locally time-periodically driven disordered nonlinear chains. For frequencies inside the band of linear Anderson modes, three different regimes are observed with increasing driver amplitude: 1) Below threshold, localized quasiperiodic oscillations and no spreading; 2) Three different regimes in time close to threshold, with almost regular oscillations initially, weak chaos and slow spreading for intermediate times, and finally strong diffusion; 3) Immediate spreading for strong driving. The thresholds are due to simple bifurcations, obtained analytically for a single oscillator, and numerically as turning-points of the nonlinear response manifold for a full chain. Generically, the threshold is nonzero also for infinite chains.

Magnus Johansson; Georgios Kopidakis; Stefano Lepri; Serge Aubry

2008-12-18T23:59:59.000Z

14

FAST: Frequency-aware static timing analysis  

Science Conference Proceedings (OSTI)

Energy is a valuable resource in embedded systems as the lifetime of many such systems is constrained by their battery capacity. Recent advances in processor design have added support for dynamic frequency/voltage scaling (DVS) for saving energy. Recent ... Keywords: Real-time systems, dynamic voltage scaling, scheduling, worst-case execution time analysis

Kiran Seth; Aravindh Anantaraman; Frank Mueller; Eric Rotenberg

2006-02-01T23:59:59.000Z

15

Four Time Periods - Energy Information Administration  

U.S. Energy Information Administration (EIA)

... we will be seeing a downward trend in differentials as time moves on. We expect the recent upturn in the light-heavy differentials to be ...

16

Periodic solution of single population models on time scales  

Science Conference Proceedings (OSTI)

By using the calculus on time scales, we study and establish criterion for the existence of periodic solutions of some scalar dynamical equations on time scales. The existence of periodic solutions for some concrete well-known single population models ... Keywords: Coincidence degree theory, Logistic equations, Periodic solutions, Time scales

Jimin Zhang; Meng Fan; Huaiping Zhu

2010-08-01T23:59:59.000Z

17

NIST Time and Frequency Division 1994 - Technical ...  

Science Conference Proceedings (OSTI)

... In three dimensions, the zero-point energy (n x =n y =n z = 0 ... During the last year, Richard Fox of the Optical Frequency Measurements Group has ...

18

High-frequency Quasi-Periodic Oscillations from GRS 1915+105 in its C state  

E-Print Network (OSTI)

We report the results of a systematic timing analysis of RXTE observations of GRS 1915+105 when the source was in its variability class theta, characterized by alternating soft and hard states on a time scale of a few hundred seconds. The aim was to examine the high-frequency part of the power spectrum in order to confirm the hecto-Hertz Quasi-Periodic Oscillations (QPO) previously reported from observations from mixed variability behaviours. During the hard intervals (corresponding to state C in the classification of Belloni et al., 2000, A&A, 35, 271), we find a significant QPO at a frequency of ~170 Hz, although much broader (Q~2) than previously reported. No other significant peak is observed at frequencies >30 Hz. A time-resolved spectral analysis of selected observations shows that the hard intervals from class theta show a stronger and steeper (Gamma=2.8-3.0) power-law component than hard intervals from other classes. We discuss these results in the framework of hecto-Hertz QPOs reported from GRS 1915+105 and other black-hole binaries.

T. Belloni; P. Soleri; P. Casella; M. Mendez; S. Migliari

2006-03-08T23:59:59.000Z

19

Time and Frequency from A to Z: Notes  

Science Conference Proceedings (OSTI)

... Unlike the glossaries produced by standards committees, Time and Frequency: From A to Z is not intended to be an official glossary of time and ...

2010-10-05T23:59:59.000Z

20

NIST Time and Frequency Division 1993 - Technical ...  

Science Conference Proceedings (OSTI)

... can be reached with commercial red diode ... the time scale when building and remodelling ... American Geophysical Union meeting in San Francisco. ...

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

NIST Time and Frequency Division History  

Science Conference Proceedings (OSTI)

... of accurate measurements of mean solar time (from ... needs of the broadcast industry, NIST initiated ... Concurrent with the development of more recent ...

2010-10-05T23:59:59.000Z

22

Publishers of Time and Frequency Software  

Science Conference Proceedings (OSTI)

... 1 Ace Software, X, Windows. Acrovista, X, Windows. Apple Computer, X, Macintosh. Atom Time, X, Windows. Beagle Software, X, X, Windows. ...

2013-03-08T23:59:59.000Z

23

NIST Time and Frequency Division 1998- Technical Highlights  

Science Conference Proceedings (OSTI)

... other fountain standards, the microwave cavity and drift tube are contained ... improved coordination of time/frequency standards on earth, and tests of ...

24

Time and Frequency from A to Z: U to W  

Science Conference Proceedings (OSTI)

... UT0 - The original mean solar time scale, based on the rotation of the Earth on its ... It has equal power per hertz over the specified frequency band. ...

2010-10-05T23:59:59.000Z

25

Time-resolved Hyperspectral Fluorescence Spectroscopy using Frequency Modulated Excitation  

SciTech Connect

An intensity-modulated excitation light source is used together with a micro channel plate intensified CCD (ICCD) detector gated at a slightly different frequency to generate a beat frequency from a fluorescent sample. The addition of a spectrograph produces a hyperspectral time-resolved data product where the resulting beat frequency is detected with a low frame rate camera. Measuring the beat frequency of the spectrum as a function of time allows separation of the excited fluorescence from ambient constant light sources. The excitation and detector repetition rates are varied over a range of discrete frequencies, and the phase shift of the beat wave maps out the emission decay rate(s).

,; Neill, M

2012-07-01T23:59:59.000Z

26

Adaptive time-frequency analysis based on autoregressive modeling  

Science Conference Proceedings (OSTI)

A new adaptive method for discrete time-frequency analysis based on autoregressive (AR) modeling is introduced. The performance of AR modeling often depends upon a good selection of the model order. The predictive least squares (PLS) principle of Rissanen ... Keywords: Adaptive filters, Autoregressive modeling, Least squares methods, Model order, Time-frequency analysis

Antonio H. Costa; Stephan Hengstler

2011-04-01T23:59:59.000Z

27

Eventrons: a safe programming construct for high-frequency hard real-time applications  

Science Conference Proceedings (OSTI)

While real-time garbage collection has achieved worst-case latencies on the order of a millisecond, this technology is approaching its practical limits. For tasks requiring extremely low latency, and especially periodic tasks with frequencies above 1 ... Keywords: allocation, real-time, scheduling

Daniel Spoonhower; Joshua Auerbach; David F. Bacon; Perry Cheng; David Grove

2006-06-01T23:59:59.000Z

28

Efficient Evaluation of Doubly Periodic Green Functions in 3D Scattering, Including Wood Anomaly Frequencies  

E-Print Network (OSTI)

We present efficient methods for computing wave scattering by diffraction gratings that exhibit two-dimensional periodicity in three dimensional (3D) space. Applications include scattering in acoustics, electromagnetics and elasticity. Our approach uses boundary-integral equations. The quasi-periodic Green function is a doubly infinite sum of scaled 3D free-space outgoing Helmholtz Green functions. Their source points are located at the nodes of a periodicity lattice of the grating. For efficient numerical computation of the lattice sum, we employ a smooth truncation. Super-algebraic convergence to the Green function is achieved as the truncation radius increases, except at frequency-wavenumber pairs at which a Rayleigh wave is at exactly grazing incidence to the grating. At these "Wood frequencies", the term in the Fourier series representation of the Green function that corresponds to the grazing Rayleigh wave acquires an infinite coefficient and the lattice sum blows up. At Wood frequencies, we modify the Green function by adding two types of terms to it. The first type adds weighted spatial shifts of the Green function to itself with singularities below the grating; this yields algebraic convergence. The second-type terms are quasi-periodic plane wave solutions of the Helmholtz equation. They reinstate (with controlled coefficients) the grazing modes, effectively eliminated by the terms of first type. These modes are needed in the Green function for guaranteeing the well-posedness of the boundary-integral equation that yields the scattered field. We apply this approach to acoustic scattering by a doubly periodic 2D grating near and at Wood frequencies and scattering by a doubly periodic array of scatterers away from Wood frequencies.

Oscar P. Bruno; Stephen P. Shipman; Catalin Turc; Stephanos Venakides

2013-07-04T23:59:59.000Z

29

Time-frequency analysis and Harmonic Gaussian Functions  

E-Print Network (OSTI)

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

Tokiniaina Ranaivoson; Raoelina Andriambololona; Rakotoson Hanitriarivo

2013-03-08T23:59:59.000Z

30

On the harmonics of the low-frequency quasi-periodic oscillation in GRS 1915+105  

E-Print Network (OSTI)

GRS 1915+105 is a widely studied black hole binary, well known because of its extremely fast and complex variability. Flaring periods of high variability alternate with "stable" phases (the plateaux) when the flux is low, the spectra are hard and the timing properties of the source are similar to those of a number of black hole candidates in hard spectral state. In the plateaux the power density spectra are dominated by a low frequency quasi periodic oscillation (LFQPO) superposed onto a band limited noise continuum and accompanied by at least one harmonic. In this paper we focus on three plateaux, presenting the analysis of the power density spectra and in particular of the LFQPO and its harmonics. While plotting the LFQPO and all the harmonics together on a frequency-width plane, we found the presence of a positive trend of broadening when the frequency increases. This trend can shed light in the nature of the harmonic content of the LFQPO and challenges the usual interpretation of these timing features.

Ratti, E M; Motta, S E

2012-01-01T23:59:59.000Z

31

Spectrometer employing optical fiber time delays for frequency resolution  

DOE Patents (OSTI)

This invention provides different length glass fibers for providing a broad range of optical time delays for short incident chromatic light pulses for the selective spatial and frequency analysis of the light with a single light detector. To this end, the frequencies of the incident light are orientated and matched with the different length fibers by dispersing the separate frequencies in space according to the respective fiber locations and lengths at the input terminal of the glass fibers. This makes the different length fibers useful in the field of plasma physics. To this end the short light pulses can be scattered by a plasma and then passed through the fibers for analyzing and diagnosing the plasma while it varies rapidly with time.

Schuss, Jack J. (Providence, RI); Johnson, Larry C. (Princeton, NJ)

1979-01-01T23:59:59.000Z

32

Electromagnetic Compatibility from a Time-Frequency Perspective  

E-Print Network (OSTI)

Abstract — In wireless communication, interference between two radio systems may occur when they operate at close frequency bands, sharing the same environment at the same time. Such systems coexist if both of them perform correctly in the presence of the other. To ensure their coexistence, Electromagnetic Compatibility (EMC) is used to specify rules within standardization bodies. According to current EMC standards, the radio spectrum has been divided into non-overlapping bands often with exclusive access. However, nowadays there is a proliferation of new digital systems sharing common frequency bands because the spectrum is a limited resource. Many of them are operating in unlicensed bands regulated by The International Telecommunications Union (ITU), for example the 2.45 GHz Industrial, Scientific and Medical (ISM) band. The frequency allocation is also changing with the emergence of digital systems and this is the case for white spaces in the broadcast television (TV) spectrum. To avoid high interference levels, it is necessary to consider some parameters related to signal variations, representing more accurately the environment. Some techniques have been proposed in the literature to reduce interference levels but they are applied to specific sharing studies. Hence, we evaluate in this paper the impact of time-frequency considerations for radio coexistence. We show that EMC studies are more precise and more representative of the reality when additional parameters relevant to the time domain are taken into account in the analysis framework. We illustrate these concepts through a specific study case. We evaluate the results for different system parameters, first considering that both of them occupy the same band and then assuming that they use overlapping but non-equal frequency bands. Index Terms — Radio coexistence, electromagnetic compatibility, frequency-domain analysis, time-domain analysis.

Najett Neji; Raul De Lacerda; Alain Azoulay; Thierry Letertre

2013-01-01T23:59:59.000Z

33

Large-Alphabet Time-Frequency Entangled Quantum Key Distribution by means of Time-to-Frequency Conversion  

E-Print Network (OSTI)

We introduce a novel time-frequency quantum key distribution (TFQKD) scheme based on photon pairs entangled in these two conjugate degrees of freedom. The scheme uses spectral detection and phase modulation to enable measurements in the temporal basis by means of time-to-frequency conversion. This allows large-alphabet encoding to be implemented with realistic components. A general security analysis for TFQKD with binned measurements reveals a close connection with finite-dimensional QKD protocols and enables analysis of the effects of dark counts on the secure key size.

J. Nunn; L. Wright; C. Söller; L. Zhang; I. A. Walmsley; B. J. Smith

2013-05-04T23:59:59.000Z

34

Pulmonary crackle detection using time-frequency and time-scale analysis  

Science Conference Proceedings (OSTI)

Pulmonary crackles are used as indicators for the diagnosis of different pulmonary disorders in auscultation. Crackles are very common adventitious transient sounds. From the characteristics of crackles such as timing and number of occurrences, the type ... Keywords: Crackle detection, Denoising, Dual-tree complex wavelet transform, Ensemble methods, Lung sounds, Support vector machines, Time-frequency and time-scale analysis

Gorkem Serbes; C. Okan Sakar; Yasemin P. Kahya; Nizamettin Aydin

2013-05-01T23:59:59.000Z

35

Changepoint Detection in Periodic and Autocorrelated Time Series  

Science Conference Proceedings (OSTI)

Undocumented changepoints (inhomogeneities) are ubiquitous features of climatic time series. Level shifts in time series caused by changepoints confound many inference problems and are very important data features. Tests for undocumented ...

Robert Lund; Xiaolan L. Wang; Qi Qi Lu; Jaxk Reeves; Colin Gallagher; Yang Feng

2007-10-01T23:59:59.000Z

36

Trends in Cyclone and Anticyclone Frequency and Comparison with Periods of Warming and Cooling over the Northern Hemisphere  

Science Conference Proceedings (OSTI)

Available datasets and pertinent climatological studies have been examined to show the statistical trends in frequency of cyclone and anticyclone events for the Northern Hemisphere during periods of warming and cooling this century (as determined ...

Ernest M. Agee

1991-02-01T23:59:59.000Z

37

Is there a link between the neutron-star spin and the frequency of the kilohertz quasi-periodic oscillations?  

E-Print Network (OSTI)

There is a general consensus that the frequencies of the kilohertz Quasi-Periodic Oscillations (kHz QPOs) in neutron-star low-mass X-ray binaries are directly linked to the spin of the neutron star. The root of this idea is the apparent clustering of the ratio of the frequency difference of the kHz QPOs and the neutron-star spin frequency, $\\Delta\

Mariano Mendez; Tomaso Belloni

2007-07-31T23:59:59.000Z

38

Extracting Information about EMRIs using Time-Frequency Methods  

E-Print Network (OSTI)

The inspirals of stellar-mass compact objects into supermassive black holes are some of the most exciting sources of gravitational waves for LISA. Detection of these sources using fully coherent matched filtering is computationally intractable, so alternative approaches are required. In Wen & Gair (2005), we proposed a detection method based on searching for significant deviation of power density from noise in a time-frequency spectrogram of the LISA data. The performance of the algorithm was assessed in Gair & Wen (2005) using Monte-Carlo simulations on several trial waveforms and approximations to the noise statistics. We found that typical extreme mass ratio inspirals (EMRIs) could be detected at distances of up to 1-3 Gpc, depending on the source parameters. In this paper, we first give an overview of our previous work in Wen & Gair (2005) and Gair & Wen (2005), and discuss the performance of the method in a broad sense. We then introduce a decomposition method for LISA data that decodes LISA's directional sensitivity. This decomposition method could be used to improve the detection efficiency, to extract the source waveform, and to help solve the source confusion problem. Our approach to constraining EMRI parameters using the output from the time-frequency method will be outlined.

Linqing Wen; Yanbei Chen; Jonathan Gair

2006-12-06T23:59:59.000Z

39

Time-frequency resolved ultrafast spectroscopy techniques using wavelet analysis  

E-Print Network (OSTI)

New experimental techniques based on non-linear ultrafast spectroscopies have been developed over the last few years, and have been demonstrated to provide powerful probes of quantum dynamics in different types of molecular aggregates, including both natural and artificial light harvesting complexes. Fourier transform-based spectroscopies have been particularly successful, yet 'complete' spectral information normally necessitates the loss of all information on the temporal sequence of events in a signal. This information though is particularly important in transient or multi-stage processes, in which the spectral decomposition of the data evolves in time. By going through several examples of ultrafast quantum dynamics, we demonstrate that the use of wavelets provide an efficient and accurate way to simultaneously acquire both temporal and frequency information about a signal, and argue that this greatly aids the elucidation and interpretation of physical process responsible for non-stationary spectroscopic features, such as those encountered in coherent excitonic energy transport.

Javier Prior; Enrique Castro; Alex W. Chin; Javier Almeida; Susana F. Huelga; Martin B. Plenio

2013-08-21T23:59:59.000Z

40

Continuous time very low frequency analog signal processors  

E-Print Network (OSTI)

In this work, basic analog integrated circuits such as integrators, multipliers, comparators, summers and impedance scaling networks which serve as the basic building blocks for designing complicated continuous time analog signal processing systems are analyzed and designed. These circuits are designed to operate at low supply voltages and consume low power. Special emphasis is laid on very low frequencies of operation (of the order of a few Hertz). For an Operational Transconductance Amplifier- Capacitor (OTA-C) integrated circuit implementation, this directly translates to a very small transconductance (of the order of a few nA/V) and a very large on-chip capacitance (of the order of several hundred pF). Both the above mentioned aspects of low frequency IC design are addressed in this thesis. Specifically, a family of OTA'S with very small transconductances has been designed using several design schemes such as current division, use of floating gate Metal Oxide Semiconductor Field Effect Transistors (MOSFET'S) and bulk driven transistors. A detailed comparison has been made among these schemes in terms of performance characteristics such as power consumption, active silicon area and signal to noise ratio. A multiplier based OTA with very small transconductance has also been designed with a view to obtain a wide transconductance tuning range. Moreover, an impedance scaling circuit has also been designed in order to realize very large capacitors on-chip. As sample applications for these circuits, a low pass filter, relaxation oscillator, band pass filter and a band pass based oscillator have also been designed. A11 circuit design has been done through a novel approach by the use of an all-region MOSFET model. A11 the above mentioned circuits have been designed, simulated and eventually fabricated in a 1.2[] NWELL CMOS process available through MOSIS. The fabricated circuits have all been tested for functionality and performance in the lab and measurement results are tabulated.

Veeravalli Raghupathy, Anand

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Dynamic Scheduling of Skippable Periodic Tasks with Energy Efficiency in Weakly Hard Real-Time System  

E-Print Network (OSTI)

Energy consumption is a critical design issue in real-time systems, especially in battery- operated systems. Maintaining high performance, while extending the battery life between charges is an interesting challenge for system designers. Dynamic Voltage Scaling (DVS) allows a processor to dynamically change speed and voltage at run time, thereby saving energy by spreading run cycles into idle time. Knowing when to use full power and when not, requires the cooperation of the operating system scheduler. Usually, higher processor voltage and frequency leads to higher system throughput while energy reduction can be obtained using lower voltage and frequency. Instead of lowering processor voltage and frequency as much as possible, energy efficient real-time scheduling adjusts voltage and frequency according to some optimization criteria, such as low energy consumption or high throughput, while it meets the timing constraints of the real-time tasks. As the quantity and functional complexity of battery powered porta...

Baskaran, Santhi

2010-01-01T23:59:59.000Z

42

CENAMEP AIP: Time and Frequency Laboratory current status  

Science Conference Proceedings (OSTI)

... DC batteries, UPS and power generator (backup for 3 days ... Phase and Frequency Offset Generator with the master clock for ... Two signal generators. ...

2012-10-09T23:59:59.000Z

43

Time and Frequency from A to Z: Am to B  

Science Conference Proceedings (OSTI)

... quantum mechanics dictate that the energies of a ... same frequency when they absorb or release energy. ... oscillators are the lowest priced and most ...

2010-10-05T23:59:59.000Z

44

NIST Time and Frequency Div. - 2004: Strategic Focus 3  

Science Conference Proceedings (OSTI)

... Such chip-scale atomic clocks need not be as accurate or stable as ... precise timekeeping and frequency control to small, battery-powered electronic ...

45

Time and Frequency from A to Z: Re to Ru  

Science Conference Proceedings (OSTI)

... The natural frequency of an oscillator. ... The optical beam from the rubidium lamp pumps the 87 Rb buffer gas atoms into a particular energy state. ...

2010-10-05T23:59:59.000Z

46

Faster and parameter-free discord search in quasi-periodic time series  

Science Conference Proceedings (OSTI)

Time series discord has proven to be a useful concept for time-series anomaly identification. To search for discords, various algorithms have been developed. Most of these algorithms rely on pre-building an index (such as a trie) for subsequences. Users ... Keywords: anomaly detection, minimax search, periodic time series, time series data mining, time series discord

Wei Luo; Marcus Gallagher

2011-05-01T23:59:59.000Z

47

Analysis of Repetitive Flash Stimulation Frequencies and Record Periods to Detect Migraine Using Artificial Neural Network  

Science Conference Proceedings (OSTI)

Different kind of methods has been applied to detect the migraine by using flash stimulation. Especially frequency analysis of EEG signal is the most preferred method to detect the migraine by using flash stimulation. Different flash stimulation frequencies ... Keywords: Artificial neural network (ANN), Electroencephalography (EEG), Flash stimulation, Migraine

Selahaddin Batuhan Akben; Abdulhamit Subasi; Deniz Tuncel

2012-04-01T23:59:59.000Z

48

Gridded Climatic Monthly Frequencies of Precipitation Amount for 1-, 3-, and 6-h Periods over the Conterminous United States  

Science Conference Proceedings (OSTI)

Gridded fields of monthly mean relative frequency for ?0.10 (2.5), ?0.25 (6.4), ?0.50 (12.7), ?1.00 (25.4), and ?2.00 (50.8) in. (mm) of precipitation have been developed for 1-, 3-, and 6-h periods over the conterminous United States. The ...

Jerome P. Charba; Yijun Liu; Matthew H. Hollar; Bryan Exley; Anwar Belayachi

1998-03-01T23:59:59.000Z

49

NIST Time and Frequency Services: Results of 2001 ...  

Science Conference Proceedings (OSTI)

... S5-2020, Thanks for the good service. ... S5-2131, WWV has been keeping all of the clocks in my house accurate as well as my receiver frequency dial ...

50

NIST Time and Frequency Services: Results of 2001 ...  

Science Conference Proceedings (OSTI)

... S3-0036, a nts server. ... S3-0218, "It would be of great benefit if NIST uplinked standard NTSC test signals, with precise frequencies and deviation, to a ...

51

Time and Frequency from A to Z: Ti  

Science Conference Proceedings (OSTI)

... Instruments such as oscilloscopes and time interval counters are ... An instrument used to measure the time interval ... The main gate controls the time at ...

2010-10-05T23:59:59.000Z

52

A Model for the Frequency of Long Periods of Drought at Forested Stations in Canada  

Science Conference Proceedings (OSTI)

Long dry spells (sequence of dry days) are rare events, but they are important because they correlate significantly with the area burned during bad wildfire years. Previous attempts to model the frequency of dry spells have been successful for ...

James Harrington; Michael Flannigan

1993-11-01T23:59:59.000Z

53

NIST Time and Frequency Services: Results of 2001 ...  

Science Conference Proceedings (OSTI)

... signals is an absolute necessity for conducting timing of ... for calibrations of equipment on my job (University). ... the time of an event for later analysis. ...

54

Femtosecond Frequency Combs for Optical Clocks and Timing Transfer  

E-Print Network (OSTI)

and optical, through 10-km-scale optical fiber links. Actively stabilizing the optical phase delay of such a fiber link, we are able to transfer a cw optical frequency standard with a transfer instability of 6 of the optical system . . . . . . . . . . . . . . . . . . . . . . 77 4.4 Comparison of results

Ye, Jun

55

An adaptive multitime multigrid algorithm for time-periodic flow simulations  

Science Conference Proceedings (OSTI)

The multiscale behaviour and multidisciplinary nature of rotorcraft aerodynamics has delayed the introduction of CFD techniques for rotorcraft aerodynamics. The numerical dissipation of standard CFD algorithms may destroy tip vortices before blade-vortex ... Keywords: 02.60.Cb, 02.70.Dh, 03.40.Gc, Multigrid, Space-time discontinuous Galerkin method, Time domain, Time-periodic

H. van der Ven

2008-05-01T23:59:59.000Z

56

Using time-frequency and wavelet analysis to assess turbulence/rotor interactions  

DOE Green Energy (OSTI)

Large loading events on wind turbine rotor blades are often associated with transient bursts of coherent turbulent energy in the turbine inflow. These coherent turbulent structures are identified as peaks in the three-dimensional, instantaneous, turbulent shearing stress field. Such organized inflow structures and the accompanying rotor aeroelastic responses typically have time scales of only a few seconds and therefore do not lend themselves for analysis by conventional Fourier spectral techniques. Time-frequency analysis (and wavelet analysis in particular) offers the ability to more closely study the spectral decomposition of short period events such as the interaction of coherent turbulence with a moving rotor blade. In this paper, the authors discuss the initial progress in the application of time-frequency analysis techniques to the decomposition and interpretation of turbulence/rotor interaction. The authors discuss the results of applying both the continuous and discrete wavelet transforms for their application. Several examples are given of the techniques applied to both observed turbulence and turbine responses and those generated using numerical simulations. They found that the presence of coherent turbulent structures, as revealed by the inflow Reynolds stress field, is a major contributor to large load excursions. These bursts of coherent turbulent energy induce a broadband aeroelastic response in the turbine rotor as it passes through them.

Kelley, N.D.; Osgood, R.M.; Bialasiewicz, J.T.; Jakubowski, A.

2000-01-05T23:59:59.000Z

57

Time and Frequency from A to Z: G  

Science Conference Proceedings (OSTI)

... it has also become perhaps the dominant system for the distribution of time ... In radio transmission, a wave that propagates close to the surface of the ...

2010-10-05T23:59:59.000Z

58

NIST Time and Frequency Division - 2001 Tech. Highlights  

Science Conference Proceedings (OSTI)

... as soon as final acceptance testing is completed. ... The objectives are to test certain aspects of ... of the NIST Network Time Service (NTS) continues to ...

59

NIST Time and Frequency Division 1998 - Current Directions  

Science Conference Proceedings (OSTI)

... The NIST Time Scale is the flywheel clock system that provides accurate signals for services and applications and serves as a reference for ...

60

NIST Time and Frequency Services: Results of 2001 ...  

Science Conference Proceedings (OSTI)

... S3-1052, low power vhf for time sync not ... S3-1056, "additional solar information and space weather ... S3-1077, A reasonable priced way of getting the ...

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

NIST Time and Frequency Services: Results of 2001 ...  

Science Conference Proceedings (OSTI)

... counter, set the clocks in the house and computers. ... I forsee a time in the future when nearly all ... I now have a WWVB-receiving solar-powered clok in ...

62

Astrophysical image separation by blind time--frequency source separation methods  

Science Conference Proceedings (OSTI)

In this paper, two prevalent blind time-frequency (TF) source separation methods in the literature are adapted to astrophysical image mixtures and four algorithms are developed to separate them into their astrophysical components. The components considered ... Keywords: Astrophysical image separation, Blind time--frequency source separation methods, Cosmic microwave background radiation, Joint diagonalization, Source separation

Mehmet Tankut Özgen; Ercan Engin Kuruo?lu; Diego Herranz

2009-03-01T23:59:59.000Z

63

Generation of multiscale magnetic field by parity-invariant time-periodic flows  

E-Print Network (OSTI)

We study generation of magnetic fields involving large spatial scales by time- and space-periodic small-scale parity-invariant flows. The anisotropic magnetic eddy diffusivity tensor is calculated by the standard procedure involving expansion of magnetic modes and their growth rates in power series in the scale ratio. Our simulations, conducted for flows with random harmonic composition and exponentially decaying energy spectra, demonstrate that enlargement of the spatial scale of magnetic field is beneficial for generation by time-periodic flows. However, they turn out, in general, to be less efficient dynamos, than steady flows.

V. A. Zheligovsky; O. M. Podvigina

2002-07-28T23:59:59.000Z

64

System and method for constructing filters for detecting signals whose frequency content varies with time  

DOE Patents (OSTI)

A system and method for constructing a bank of filters which detect the presence of signals whose frequency content varies with time. The present invention includes a novel system and method for developing one or more time templates designed to match the received signals of interest and the bank of matched filters use the one or more time templates to detect the received signals. Each matched filter compares the received signal x(t) with a respective, unique time template that has been designed to approximate a form of the signals of interest. The robust time domain template is assumed to be of the order of w(t)=A(t)cos{2.pi..phi.(t)} and the present invention uses the trajectory of a joint time-frequency representation of x(t) as an approximation of the instantaneous frequency function {.phi.'(t). First, numerous data samples of the received signal x(t) are collected. A joint time frequency representation is then applied to represent the signal, preferably using the time frequency distribution series (also known as the Gabor spectrogram). The joint time-frequency transformation represents the analyzed signal energy at time t and frequency .function., P(t,f), which is a three-dimensional plot of time vs. frequency vs. signal energy. Then P(t,f) is reduced to a multivalued function f(t), a two dimensional plot of time vs. frequency, using a thresholding process. Curve fitting steps are then performed on the time/frequency plot, preferably using Levenberg-Marquardt curve fitting techniques, to derive a general instantaneous frequency function .phi.'(t) which best fits the multivalued function f(t), a trajectory of the joint time-frequency domain representation of x(t). Integrating .phi.'(t) along t yields .phi.(t), which is then inserted into the form of the time template equation. A suitable amplitude A(t) is also preferably determined. Once the time template has been determined, one or more filters are developed which each use a version or form of the time template.

Qian, Shie (Austin, TX); Dunham, Mark E. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

65

Locking-time and Information Capacity in CML with Statistical Periodicity  

E-Print Network (OSTI)

In this work we address the statistical periodicity phenomenon on a coupled map lattice. The study was done based on the asymptotic binary patterns. The pattern multiplicity gives us the lattice information capacity, while the entropy rate allows us to calculate the locking-time. Our results suggest that the lattice has low locking-time and high capacity information when the coupling is weak. This is the condition for the system to reproduce a kind of behavior observed in neural networks.

Romeu Miqueias Szmoski; Rodrigo Frehse Pereira; Fabiano Alan Serafim Ferrari; Sandro Ely de Souza Pinto

2010-11-24T23:59:59.000Z

66

LOW-FREQUENCY QUASI-PERIODIC OSCILLATION FROM THE 11 Hz ACCRETING PULSAR IN TERZAN 5: NOT FRAME DRAGGING  

Science Conference Proceedings (OSTI)

We report on six RXTE observations taken during the 2010 outburst of the 11 Hz accreting pulsar IGR J17480-2446 located in the globular cluster Terzan 5. During these observations we find power spectra which resemble those seen in Z-type high-luminosity neutron star low-mass X-ray binaries, with a quasi-periodic oscillation (QPO) in the 35-50 Hz range simultaneous with a kHz QPO and broadband noise. Using well-known frequency-frequency correlations, we identify the 35-50 Hz QPOs as the horizontal branch oscillations, which were previously suggested to be due to Lense-Thirring (LT) precession. As IGR J17480-2446 spins more than an order of magnitude more slowly than any of the other neutron stars where these QPOs were found, this QPO cannot be explained by frame dragging. By extension, this casts doubt on the LT precession model for other low-frequency QPOs in neutron stars and perhaps even black hole systems.

Altamirano, D.; Van der Klis, M.; Wijnands, R. [Astronomical Institute, 'Anton Pannekoek', University of Amsterdam, Science Park 904, 1098XH Amsterdam (Netherlands); Ingram, A. [Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Linares, M.; Homan, J., E-mail: d.altamirano@uva.nl [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States)

2012-11-01T23:59:59.000Z

67

System and method for constructing filters for detecting signals whose frequency content varies with time  

DOE Patents (OSTI)

A system and method are disclosed for constructing a bank of filters which detect the presence of signals whose frequency content varies with time. The present invention includes a novel system and method for developing one or more time templates designed to match the received signals of interest and the bank of matched filters use the one or more time templates to detect the received signals. Each matched filter compares the received signal x(t) with a respective, unique time template that has been designed to approximate a form of the signals of interest. The robust time domain template is assumed to be of the order of w(t)=A(t)cos(2{pi}{phi}(t)) and the present invention uses the trajectory of a joint time-frequency representation of x(t) as an approximation of the instantaneous frequency function {phi}{prime}(t). First, numerous data samples of the received signal x(t) are collected. A joint time frequency representation is then applied to represent the signal, preferably using the time frequency distribution series. The joint time-frequency transformation represents the analyzed signal energy at time t and frequency f, P(t,f), which is a three-dimensional plot of time vs. frequency vs. signal energy. Then P(t,f) is reduced to a multivalued function f(t), a two dimensional plot of time vs. frequency, using a thresholding process. Curve fitting steps are then performed on the time/frequency plot, preferably using Levenberg-Marquardt curve fitting techniques, to derive a general instantaneous frequency function {phi}{prime}(t) which best fits the multivalued function f(t). Integrating {phi}{prime}(t) along t yields {phi}{prime}(t), which is then inserted into the form of the time template equation. A suitable amplitude A(t) is also preferably determined. Once the time template has been determined, one or more filters are developed which each use a version or form of the time template. 7 figs.

Qian, S.; Dunham, M.E.

1996-11-12T23:59:59.000Z

68

Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting  

E-Print Network (OSTI)

Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting}@binghamton.edu Abstract In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm energy and the harvested energy in a future duration. Specifically, if the system has sufficient energy

Qiu, Qinru

69

Time & Frequency  

Science Conference Proceedings (OSTI)

... Bay, GA [200403- 0] ID. Idaho National Laboratory -Calibration Services Dept., Idaho Falls, ID [200115- 0] IN. Eli Lilly and ...

2013-07-26T23:59:59.000Z

70

Time & Frequency  

Science Conference Proceedings (OSTI)

... Oak Ridge, TN [105000- 0] Oak Ridge National Laboratory - Metrology, Oak Ridge, TN [200659 ... of Virginia Metrology Lab, Richmond, VA ...

2013-08-09T23:59:59.000Z

71

Tunneling of Massive Dirac Fermions in Graphene through Time-periodic Potential  

E-Print Network (OSTI)

The energy spectrum of graphene sheet with a single barrier structure having a time periodic oscillating height and subjected to magnetic field is analyzed. The corresponding transmission is studied as function of the obtained energy and the potential parameters. Quantum interference within the oscillating barrier has an important effect on quasiparticles tunneling. In particular the time-periodic electromagnetic field generates additional sidebands at energies \\epsilon + l\\hbar \\omega (l=0,\\pm 1, \\cdots) in the transmission probability originating from the photon absorption or emission within the oscillating barrier. Due to numerical difficulties in truncating the resulting coupled channel equations we limited ourselves to low quantum channels, i.e. l=0,\\pm 1.

Ahmed Jellal; Miloud Mekkaoui; El Bouazzaoui Choubabi; Hocine Bahlouli

2013-11-29T23:59:59.000Z

72

Blind Separation of Underdetermined Convolutive Mixtures Using Their Time–Frequency Representation  

Science Conference Proceedings (OSTI)

This paper considers the blind separation of nonstationary sources in the underdetermined convolutive mixture case. We introduce, two methods based on the sparsity assumption of the sources in the time-frequency (TF) domain. The first one assumes that ... Keywords: Blind source separation (BSS), convolutive mixture, sparse signal decomposition/representation, speech signals, subspace projection, time–frequency distribution (TFD), underdetermined/overcomplete representation, vector clustering

A. Aissa-El-Bey; K. Abed-Meraim; Y. Grenier

2007-07-01T23:59:59.000Z

73

Leakage-Aware Reallocation for Periodic Real-Time Tasks on Multicore Processors  

E-Print Network (OSTI)

It is an increasingly important issue to reduce the energy consumption of computing systems. In this paper, we consider partition based energy-aware scheduling of periodic real-time tasks on multicore processors. The scheduling exploits dynamic voltage scaling (DVS) and core sleep scheduling to reduce both dynamic and leakage energy consumption. If the overhead of core state switching is non-negligible, however, the performance of this scheduling strategy in terms of energy efficiency might degrade. To achieve further energy saving, we extend the static task scheduling with run-time task reallocation. The basic idea is to aggregate idle time among cores so that as many cores as possible could be put into sleep in a way that the overall energy consumption is reduced. Simulation results show that the proposed approach results in up to 20% energy saving over traditional leakage-aware DVS.

Huang, Hongtao; Wang, Jijie; Lei, Siyu; Wu, Guowei

2010-01-01T23:59:59.000Z

74

Ultrafast time dynamics studies of periodic lattices with free electron laser radiation  

Science Conference Proceedings (OSTI)

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.

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

75

Real-Time Prediction of Power System Frequency in FNET: A State Space Approach  

SciTech Connect

This paper proposes a novel approach to predict power frequency by applying a state-space model to describe the time-varying nature of power systems. It introduces the Expectation maximization (EM) and prediction error minimization (PEM) algorithms to dynamically estimate the parameters of the model. This paper discusses how the proposed models can be used to ensure the efficiency and reliability of power systems in Frequency Monitoring Network (FNET), if serious frequency fluctuation or measurement failure occur at some nodes; this is achieved without requiring the exact model of complex power systems. Our approach leads to an easy online implementation with high precision and short response time that are key to effective frequency control. We randomly pick a set of frequency data for one power station in FNET and use it to estimate and predict the power frequency based on past measurements. Several computer simulations are provided to evaluate the method. Simulation results showed that the proposed technique could achieve good performance regarding the frequency monitoring with very limited measurement input information.

Djouadi, Seddik M [ORNL] [ORNL; Kuruganti, Phani Teja [ORNL] [ORNL; Ma, Xiao [ORNL] [ORNL

2013-01-01T23:59:59.000Z

76

Development of periodic response factors for use with the radiant time series method  

SciTech Connect

Harris and McQuiston (1988) developed conduction transfer function (CTF) coefficients corresponding to 41 representative wall assemblies and 42 representative roof assemblies for use with the transfer function method (TFM). They also developed a grouping procedure that allows design engineers to determine the correct representative wall or roof assembly that most closely matches a specific wall or roof assembly. The CTF coefficients and the grouping procedure have been summarized in the ASHRAE Handbook--Fundamentals (1989, 1993, 1997) and the ASHRAE Cooling and Heating Load Calculation Manual, second edition. More recently, a new, simplified design cooling load calculation procedure, the radiant time series method (RTSM), has been developed. The RTSM uses periodic response factors to model transient conductive heat transfer. While not a true manual load calculation procedure, it is quite feasible to implement the RTSM in a spreadsheet. To be useful in such an environment, it would be desirable to have a pre-calculated set of periodic response factors. Accordingly, a set of periodic response factors has been calculated and is presented in this paper.

Spitler, J.D.; Fisher, D.E.

1999-07-01T23:59:59.000Z

77

ARECIBO MULTI-FREQUENCY TIME-ALIGNED PULSAR AVERAGE-PROFILE AND POLARIZATION DATABASE  

Science Conference Proceedings (OSTI)

We present Arecibo time-aligned, total intensity profiles for 46 pulsars over an unusually wide range of radio frequencies and multi-frequency, polarization-angle density diagrams, and/or polarization profiles for 57 pulsars at some or all of the frequencies 50, 111/130, 430, and 1400 MHz. The frequency-dependent dispersion delay has been removed in order to align the profiles for study of their spectral evolution, and wherever possible the profiles of each pulsar are displayed on the same longitude scale. Most of the pulsars within Arecibo's declination range that are sufficiently bright for such spectral or single pulse analysis are included in this survey. The calibrated single pulse sequences and average profiles are available by web download for further study.

Hankins, Timothy H. [Physics Department, New Mexico Tech, Socorro, NM 87801 (United States); Rankin, Joanna M. [Physics Department, University of Vermont, Burlington, VT 05401 (United States)], E-mail: thankins@nrao.edu, E-mail: Joanna.Rankin@uvm.edu

2010-01-15T23:59:59.000Z

78

Time and Frequency Response of a Resistance-Wire Aircraft Atmospheric Temperature Sensor  

Science Conference Proceedings (OSTI)

The heat transfer characteristics of an aircraft-mounted resistance-wire atmospheric temperature sensor are modeled to determine the time and frequency responses. The sensor element (Rosemount 102E4AL) consists of a 25-?m-diameter platinum wire ...

G. A. Payne; C. A. Friehe; D. K. Edwards

1994-04-01T23:59:59.000Z

79

Low-Frequency Variability in the Northern Hemisphere Winter: Geographical Distribution, Structure and Time-Scale Dependence  

Science Conference Proceedings (OSTI)

Low-frequency variability in wintertime 500 mb height is examined, with emphasis on its structure, geographical distribution, and frequency dependence. A 39-year record of 500 mb geopotential height fields from the NMC analyses is time filtered ...

Yochanan Kushnir; John M. Wallace

1989-10-01T23:59:59.000Z

80

Growth mechanism of photoreduced silver nanostructures on periodically proton exchanged lithium niobate: Time and concentration dependence  

SciTech Connect

Photodeposition of metallic nanostructures onto ferroelectric surfaces, which have been chemically patterned using a proton exchange process, has recently been demonstrated. By varying the molar concentration of the AgNO{sub 3} solution and the illumination time, one can determine the initial nucleation sites, control the rate of nucleation and the height of silver nanostructures formed, and study the mechanisms by which these processes occurs. The nanoparticles are found to deposit preferentially in the boundary between ferroelectric and proton exchanged regions, in an area proton exchanged via lateral diffusion under the masking layer used for chemical patterning, consistent with our previous results. Using a short illumination time (3 min), we are able to determine that the initial nucleation of the silver nanostructure, having a width of 0.17 {+-} 0.02 {mu}m and a height of 1.61 {+-} 0.98 nm, occurs near the edge of the reactive ion etched area within this lateral diffusion region. Over longer illumination times (15 min), we find that the silver deposition has spread to a width of 1.29 {+-} 0.06 {mu}m, extending across the entire lateral diffusion region. We report that at a high molar concentration of AgNO{sub 3} (10{sup -2} M), the amount of silver deposition for 5 min UV illumination is greater (2.88 {+-} 0.58 nm) compared to that at low (10{sup -4} M) concentrations (0.78 {+-} 0.35 nm), however, this is not the case for longer time periods. With increasing illumination time (15 min), experiments at 10{sup -4} M had greater overall deposition, 6.90 {+-} 1.52 nm, compared to 4.50 {+-} 0.76 nm at 10{sup -2} M. For longer exposure times (30 min) at 10{sup -2} M, the nanostructure height is 4.72 {+-} 0.59 nm, suggesting a saturation in the nanostructure height. The results are discussed in terms of the electric double layer that forms at the crystal surface. There is an order of magnitude difference between the Debye lengths for 10{sup -2} and 10{sup -4} M solutions, i.e., 3.04 vs. 30.40 nm, which suggests the Debye length plays a role in the availability of Ag{sup +} ions at the surface.

Craig Carville, N.; Denning, Denise; Rodriguez, Brian J. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland) [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4 (Ireland); Manzo, Michele; Gallo, Katia [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)] [Department of Applied Physics, KTH-Royal Institute of Technology, Roslagstullbacken 21, 106 91 Stockholm (Sweden)

2013-05-14T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Generating Periodic Terahertz Structures in a Relativistic Electron Beam through Frequency Down-Conversion of Optical Lasers  

SciTech Connect

We report generation of density modulation at terahertz (THz) frequencies in a relativistic electron beam through laser modulation of the beam longitudinal phase space. We show that by modulating the energy distribution of the beam with two lasers, density modulation at the difference frequency of the two lasers can be generated after the beam passes through a chicane. In this experiment, density modulation around 10 THz was generated by down-converting the frequencies of an 800 nm laser and a 1550 nm laser. The central frequency of the density modulation can be tuned by varying the laser wavelengths, beam energy chirp, or momentum compaction of the chicane. This technique can be applied to accelerator-based light sources for generation of coherent THz radiation and marks a significant advance toward tunable narrow-band THz sources.

Dunning, Michael

2012-07-19T23:59:59.000Z

82

Choosing beacon periods to improve response times for wireless HTTP clients  

Science Conference Proceedings (OSTI)

The IEEE 802.11 wireless LAN standard power-saving mode (PSM) allows the network interface card (NIC) to periodically sleep between receiving data. In this paper, we show that 802.11 PSM performs poorly due to the fact that an access point is unable ... Keywords: beacon periods, wireless access

Suman Nath; Zachary Anderson; Srinivasan Seshan

2004-10-01T23:59:59.000Z

83

Influence of Choice of Time Period on Global Surface Temperature Trend Estimates  

Science Conference Proceedings (OSTI)

Annual global surface temperature and global land surface temperature trends are calculated for all possible periods of the historical record between 1850 and 2009. Two-dimensional parameter diagrams show the critical influence of the choice of ...

Brant Liebmann; Randall M. Dole; Charles Jones; Ileana Bladé; Dave Allured

2010-11-01T23:59:59.000Z

84

Orbit compensation for the time-varying elliptically polarized wiggler with switching frequency at 100 hz  

SciTech Connect

In October 1996, the elliptically polarized wiggler, installed in the X13 straight section of the NSLS X-ray ring, was commissioned at an operating frequency of 100 hz. This wiggler generates circularly polarized photons in the energy range of 0.1 to 10 keV with AC modulation of polarization helicity. The vertical magnetic field is produced by a hybrid permanent magnet structure, and the horizontal magnetic field is generated by an electromagnet capable of switching at frequencies up to 100 hz. Here, the authors discuss the compensation of the residual vertical and horizontal orbit motion utilizing a time-domain algorithm employing a function generator to drive trim coils at the wiggler ends, and the wideband high precision orbit measurement system of the X-ray ring. The residual orbit motion has been reduced to a level below 1 micron, and the device has been run in regular operations with no negative effect on other users.

Singh, O.; Krinsky, S.

1997-07-01T23:59:59.000Z

85

Timing the Kilohertz Quasi-Periodic Oscillations in Low-mass X-ray Binaries  

E-Print Network (OSTI)

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.

Mariano Mendez

2000-06-19T23:59:59.000Z

86

Gang FTP scheduling of periodic and parallel rigid real-time tasks  

E-Print Network (OSTI)

In this paper we consider the scheduling of periodic and parallel rigid tasks. We provide (and prove correct) an exact schedulability test for Fixed Task Priority (FTP) Gang scheduler sub-classes: Parallelism Monotonic, Idling, Limited Gang, and Limited Slack Reclaiming. Additionally, we study the predictability of our schedulers: we show that Gang FJP schedulers are not predictable and we identify several sub-classes which are actually predictable. Moreover, we extend the definition of rigid, moldable and malleable jobs to recurrent tasks.

Goossens, Joël

2010-01-01T23:59:59.000Z

87

Delimiting “Thunderstorm Watch” Periods by Real-Time Lightning Location for a Power Utility Company  

Science Conference Proceedings (OSTI)

During times of thunderstorm activity, the power utility serving metropolitan New York enters a potentially costly “thunderstorm watch” mode of operation which is designed to prevent a major power outage caused by lightning. To evaluate the ...

Vincent P. Idone; Richard E. Orville

1990-03-01T23:59:59.000Z

88

Direct atomic-orbital-based time-dependent Hartree-Fock calculations of frequency-dependent polarizabilities  

E-Print Network (OSTI)

Direct atomic-orbital-based time-dependent Hartree-Fock calculations of frequencyDepartment, Universityof Utah, Salt Lake City, Utah 84112 (Received 27 September 1991; accepted 13 November 1991) We have formulated and implemented a direct atomic integral driven method for the calculation of frequency

Simons, Jack

89

Detecting extreme mass ratio inspirals with LISA using time-frequency methods II: search characterization  

E-Print Network (OSTI)

The inspirals of stellar-mass compact objects into supermassive black holes constitute some of the most important sources for LISA. Detection of these sources using fully coherent matched filtering is computationally intractable, so alternative approaches are required. In a previous paper (Wen and Gair 2005, gr-qc/0502100), we outlined a detection method based on looking for excess power in a time-frequency spectrogram of the LISA data. The performance of the algorithm was assessed using a single `typical' trial waveform and approximations to the noise statistics. In this paper we present results of Monte Carlo simulations of the search noise statistics and examine its performance in detecting a wider range of trial waveforms. We show that typical extreme mass ratio inspirals (EMRIs) can be detected at distances of up to 1--3 Gpc, depending on the source parameters. We also discuss some remaining issues with the technique and possible ways in which the algorithm can be improved.

Gair, J; Gair, Jonathan; Wen, Linqing

2005-01-01T23:59:59.000Z

90

Detecting extreme mass ratio inspirals with LISA using time-frequency methods II: search characterization  

E-Print Network (OSTI)

The inspirals of stellar-mass compact objects into supermassive black holes constitute some of the most important sources for LISA. Detection of these sources using fully coherent matched filtering is computationally intractable, so alternative approaches are required. In a previous paper (Wen and Gair 2005, gr-qc/0502100), we outlined a detection method based on looking for excess power in a time-frequency spectrogram of the LISA data. The performance of the algorithm was assessed using a single `typical' trial waveform and approximations to the noise statistics. In this paper we present results of Monte Carlo simulations of the search noise statistics and examine its performance in detecting a wider range of trial waveforms. We show that typical extreme mass ratio inspirals (EMRIs) can be detected at distances of up to 1--3 Gpc, depending on the source parameters. We also discuss some remaining issues with the technique and possible ways in which the algorithm can be improved.

Jonathan Gair; Linqing Wen

2005-06-23T23:59:59.000Z

91

Low-Frequency Modulation of Turbulent Diapycnal Mixing by Anticyclonic Eddies Inferred from the HOT Time Series  

Science Conference Proceedings (OSTI)

Profiles of potential density obtained from CTD measurements during the Hawaii Ocean Time series (HOT) program in the vicinity of the island of Oahu, Hawaii, are used to evaluate low-frequency variability of turbulent kinetic dissipation rates ...

Zhao Jing; Lixin Wu

2013-04-01T23:59:59.000Z

92

Frequency variations of quasi-periodic ELF-VLF emissions: A possible new ground-based diagnostic of the outer high-latitude magnetosphere  

SciTech Connect

Magnetic pulsations and quasi-periodic (QP) amplitude modulations of ELF-VLF waves at Pc 3-4 frequencies (15-50 mHz) are commonly observed simultaneously in cusp-latitude data. The naturally occurring ELF-VLF emissions are believed to be modulated within the magnetosphere by the compressional component of geomagnetic pulsations formed external to the magnetosphere. The authors have examined data from South Pole Station (L {approximately} 14) to determine the occurrence and characteristics of QP emissions. On the basis of 14 months of data during 1987 and 1988 they found that QP emissions typically appeared in both the 0.5-1 kHz and 1-2 kHz receiver channels at South Pole Station and ocassionally in the 2-4 kHz channel. The QP emission frequency appeared to depend on solar wind parameters and interplanetary magnetic field (IMF) direction, and the months near fall equinox in both 1987 and 1988 showed a significant increase in the percentage of QP emissions only in the lowest-frequency channel. The authors present a model consistent with these variations in which high-latitude (nonequatorial) magnetic field minima near the magnetopause play a major role, because the field magnitude governs both the frequency of ELF-VLF emissions and the whistler mode propagation cutoffs. Because the field in these regions will be strongly influenced by solar wind and IMF parameters, variations in the frequency of such emissions may be useful in providing ground-based diagnostics of the outer high-latitude magnetosphere. 32 refs., 13 figs.

Alford, J.; Engebretson, M. [Ausburg College, Minneapolis, MN (United States); Arnoldy, R. [Univ. of New Hampshire, Durham, NH (United States); Inan, U. [Stanford Univ., CA (United States)

1996-01-01T23:59:59.000Z

93

Long-time solvability of the Navier-Stokes-Boussinesq equations with almost periodic initial large data  

E-Print Network (OSTI)

We investigate large time existence of solutions of the Navier-Stokes-Boussinesq equations with spatially almost periodic large data when the density stratification is sufficiently large. In 1996, Kimura and Herring \\cite{KH} examined numerical simulations to show a stabilizing effect due to the stratification. They observed scattered two-dimensional pancake-shaped vortex patches lying almost in the horizontal plane. Our result is a mathematical justification of the presence of such two-dimensional pancakes. To show the existence of solutions for large times, we use $\\ell^1$-norm of amplitudes. Existence for large times is then proven using techniques of fast singular oscillating limits and bootstrapping argument from a global-in-time unique solution of the system of limit equations.

Ibrahim, Slim

2011-01-01T23:59:59.000Z

94

NIST Time and Frequency Div. - 2005-2007: Strategic Focus 1  

Science Conference Proceedings (OSTI)

... calcium optical standard, based on a 657 nm (456 THz) transition, is particularly robust and well suited as a frequency reference (“flywheel”) for inter ...

95

NIST Time and Frequency Div. - 2005-2007: Strategic Focus 3  

Science Conference Proceedings (OSTI)

... Such chip-scale atomic clocks need not be as accurate or stable as ... precise timekeeping and frequency control to small, battery-powered electronic ...

96

Frequency and time profiles of metric wave isolated Type I solar noise storm bursts at high spectral and temporal resolution  

E-Print Network (OSTI)

Type I noise storms constitute a sizeable faction of the active-Sun radio emission component. Observations of isolated instances of such bursts, in the swept-frequency-mode at metric wavelengths, have remained sparse, with several unfilled regions in the frequency coverage. Dynamic spectra of the burst radiation, in the 30 - 130 MHz band, obtained from the recently commissioned digital High Resolution Spectrograph (HRS) at the Gauribidanur Radio Observatory, on account of the superior frequency and time resolution, have unravelled in explicit detail the temporal and spectral profiles of isolated bursts. Apart from presenting details on their fundamental emission features, the time and frequency profile symmetry, with reference to custom-specific Gaussian distributions, has been chosen as the nodal criterion to statistically explain the state of the source regions in the vicinity of magnetic reconnections, the latent excitation agent that contributes to plasma wave energetics, and the quenching phenomenon that causes damping of the burst emission.

G. A. Shanmugha Sundaram; K. R. Subramanian

2005-02-18T23:59:59.000Z

97

Frequency and time profiles of metric wave isolated Type I solar noise storm bursts at high spectral and temporal resolution  

E-Print Network (OSTI)

Type I noise storms constitute a sizeable faction of the active-Sun radio emission component. Observations of isolated instances of such bursts, in the swept-frequency-mode at metric wavelengths, have remained sparse, with several unfilled regions in the frequency coverage. Dynamic spectra of the burst radiation, in the 30 - 130 MHz band, obtained from the recently commissioned digital High Resolution Spectrograph (HRS) at the Gauribidanur Radio Observatory, on account of the superior frequency and time resolution, have unravelled in explicit detail the temporal and spectral profiles of isolated bursts. Apart from presenting details on their fundamental emission features, the time and frequency profile symmetry, with reference to custom-specific Gaussian distributions, has been chosen as the nodal criterion to statistically explain the state of the source regions in the vicinity of magnetic reconnections, the latent excitation agent that contributes to plasma wave energetics, and the quenching phenomenon that...

Sundaram, G A S

2005-01-01T23:59:59.000Z

98

Real-time synchronization feedbacks for single-atom frequency standards  

E-Print Network (OSTI)

Simple feedback loops, inspired from extremum-seeking, are proposed to lock a probe-frequency to the transition frequency of a single quantum system following quantum Monte-Carlo trajectories. Two specific quantum systems are addressed, a 2-level one and a 3-level one that appears in coherence population trapping and optical pumping. For both systems, the feedback algorithm is shown to be convergent in the following sense: the probe frequency converges in average towards the system-transition one and its standard deviation can be made arbitrarily small. Closed-loop simulations illustrate robustness versus jump-detection efficiency and modeling errors.

Mazyar Mirrahimi; Pierre Rouchon

2008-06-09T23:59:59.000Z

99

Measurements of time average series resonance effect in capacitively coupled radio frequency discharge plasma  

Science Conference Proceedings (OSTI)

Self-excited plasma series resonance is observed in low pressure capacitvely coupled radio frequency discharges as high-frequency oscillations superimposed on the normal radio frequency current. This high-frequency contribution to the radio frequency current is generated by a series resonance between the capacitive sheath and the inductive and resistive bulk plasma. In this report, we present an experimental method to measure the plasma series resonance in a capacitively coupled radio frequency argon plasma by modifying the homogeneous discharge model. The homogeneous discharge model is modified by introducing a correction factor to the plasma resistance. Plasma parameters are also calculated by considering the plasma series resonances effect. Experimental measurements show that the self-excitation of the plasma series resonance, which arises in capacitive discharge due to the nonlinear interaction of plasma bulk and sheath, significantly enhances both the Ohmic and stochastic heating. The experimentally measured total dissipation, which is the sum of the Ohmic and stochastic heating, is found to increase significantly with decreasing pressure.

Bora, B.; Bhuyan, H.; Favre, M.; Wyndham, E.; Chuaqui, H. [Facultad de Fisica, Pontificia Universidad Catolica de Chile, Ave. Vicuna Mackenna 4860, Santiago 22 (Chile); Kakati, M. [Thermal Plasma Processed Materials Laboratory, Centre of Plasma Physics, Institute for Plasma Research, Sonapur 782 402, Assam (India)

2011-10-15T23:59:59.000Z

100

Energy aware dynamic voltage and frequency selection for real-time systems with energy harvesting  

Science Conference Proceedings (OSTI)

In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm is proposed. The EA-DVFS algorithm adjusts the processor's behavior depending on the summation of the stored energy and the harvested energy in a future duration. ...

Shaobo Liu; Qinru Qiu; Qing Wu

2008-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

TIME DELAYS IN QUASI-PERIODIC PULSATIONS OBSERVED DURING THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15  

Science Conference Proceedings (OSTI)

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.

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

102

Summary of Time Period-Based and Other Approximation Methods for Determining the Capacity Value of Wind and Solar in the United States: September 2010 - February 2012  

DOE Green Energy (OSTI)

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.

Rogers, J.; Porter, K.

2012-03-01T23:59:59.000Z

103

Time-Frequency Analysis of GALLEX and GNO Solar Neutrino Data: Evidence Suggestive of Asymmetric and Variable Nuclear Burning  

E-Print Network (OSTI)

Time-frequency analysis of data from the GALLEX and GNO solar neutrino experiments shows that some features in power-spectrum analyses of those datasets are due to aliasing. We normalize data for each of the four experiments in the GALLEX series, concatenate the resulting normalized data, and then form time-frequency displays. We also form time-frequency displays of the two principal modulations found in the data, at 11.87 yr-1 and at 13.63 yr-1, and of the datasets formed by subtracting these modulations from the actual (normalized) data. The results suggest that the true modulation is that at 11.87 yr-1, consistent with the results of our earlier analysis of Homestake solar neutrino data. Comparison with helioseismology data indicates that modulation is occurring either in the radiative zone just below the tachocline, presumably by the RSFP (resonant spin-flavor precession) process, or in the core, presumably due to inhomogeneities and fluctuations in the nuclear-burning process.

P. A. Sturrock

2008-02-22T23:59:59.000Z

104

Time-dependent hydrogen and helium pressure profiles in a long, cryogenically cooled tube, pumped at periodic intervals  

DOE Green Energy (OSTI)

Many particle accelerators and colliders throughout the world make use of superconducting magnets to focus highly relativistic beams. These magnets are cooled to [approximately]4.2[degree]K For practical reasons, the beam pipes, encircled by the magnets, also operate at these cryogenic temperatures. This paper presents a theoretical model for determining pressure profiles, in space and time, stemming from either hydrogen or helium gas leak into the cold-bore tube with appendage pumps located at periodic intervals. It is shown that a wave-like pressure gradient propagates from the leak source at a rate which is dependent on the leak magnitude, gas species, speed and location of appendage pumps, and the geometry and effective roughness of the cold-bore tube. Steady-state, linear pressure gradients eventually equilibrate between the appendage pumps in a magnitude commensurate with both the adsorption isotherm of the species and mass flow in the beam pipe. Results are given for a variety of conditions relevant to the Relativistic Heavy Ion Collider being constructed at Brookhaven, and a general procedure, with expressions, is provided for the making of similar calculations in other installations.

Hobson, J.P. (National Vacuum Technologies, Inc., Ontario (Canada)); Welch, K.M. (Brookhaven National Lab., Upton, NY (United States))

1992-01-01T23:59:59.000Z

105

An Extended and More Sensitive Search for Periodicities in Rossi X-ray Timing Explorer/all-sky Monitor X-ray Light Curves  

E-Print Network (OSTI)

We present the results of a systematic search in ~14 years of Rossi X-ray Timing Explorer All-Sky Monitor (ASM) data for evidence of periodicities. Two variations of the commonly used Fourier analysis search method have ...

Levine, Alan M.

106

Calculation of HVDC-converter harmonics in frequency domain with regard to asymmetries and comparison with time domain simulations  

SciTech Connect

In order to study the effects of large HVDC converters to the feeding ac networks, it is of importance to explain and to calculate harmonic phenomena which are a result of converter operation. During commissioning of real HVDC converters it could be seen, that harmonics resulting from unsymmetries in the system voltages or from unsymmetries in converter operation led to significant difficulties concerning the system design. For this reason, not only the effects of characteristic but also the effects of noncharacteristic converter harmonics must be taken into account. The aim is to describe the steady state harmonic behavior of the converter. The harmonic spectra are not determined by time domain analysis but instead the solution is found by frequency domain calculations. This can result in reduced calculation time in comparison to conventional fourier analysis of the time functions. The converter is interpreted as an amplitude modulator with voltage and current converter functions which describe the coupling of the dc circuit and the ac network through the converter. To verify the theory, comparison of frequency domain with time domain calculations were carried out.

Rittiger, J. [Siemens AG, Erlangen (Germany); Kulicke, B. [Technische Univ. Berlin (Germany)

1995-10-01T23:59:59.000Z

107

I. Pastirk, page 1 2D (time-frequency) femtosecond four-wave  

E-Print Network (OSTI)

laser intensity. Notice that the blue and red wings seen in Fig 1a, are replaced by a series. Both O2 and CS2 show time delayed `wings' that extend to several hundreds of femtoseconds. These features correspond to the O (? J=-2, blue shifted) and S (? J=+2, red shifted) branches and are caused

Dantus, Marcos

108

DIAGNOSING THE TIME-DEPENDENCE OF ACTIVE REGION CORE HEATING FROM THE EMISSION MEASURE. I. LOW-FREQUENCY NANOFLARES  

Science Conference Proceedings (OSTI)

Observational measurements of active region emission measures contain clues to the time dependence of the underlying heating mechanism. A strongly nonlinear scaling of the emission measure with temperature indicates a large amount of hot plasma relative to warm plasma. A weakly nonlinear (or linear) scaling of the emission measure indicates a relatively large amount of warm plasma, suggesting that the hot active region plasma is allowed to cool and so the heating is impulsive with a long repeat time. This case is called low-frequency nanoflare heating, and we investigate its feasibility as an active region heating scenario here. We explore a parameter space of heating and coronal loop properties with a hydrodynamic model. For each model run, we calculate the slope {alpha} of the emission measure distribution EM(T){proportional_to}T {sup {alpha}}. Our conclusions are: (1) low-frequency nanoflare heating is consistent with about 36% of observed active region cores when uncertainties in the atomic data are not accounted for; (2) proper consideration of uncertainties yields a range in which as many as 77% of observed active regions are consistent with low-frequency nanoflare heating and as few as zero; (3) low-frequency nanoflare heating cannot explain observed slopes greater than 3; (4) the upper limit to the volumetric energy release is in the region of 50 erg cm{sup -3} to avoid unphysical magnetic field strengths; (5) the heating timescale may be short for loops of total length less than 40 Mm to be consistent with the observed range of slopes; (6) predicted slopes are consistently steeper for longer loops.

Bradshaw, S. J.; Reep, J. W. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Klimchuk, J. A., E-mail: stephen.bradshaw@rice.edu, E-mail: jeffrey.reep@rice.edu, E-mail: james.a.klimchuk@nasa.gov [NASA Goddard Space Flight Center, Solar Physics Lab., Code 671, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

2012-10-10T23:59:59.000Z

109

Spin relaxation and linear-in-electric-field frequency shift in an arbitrary, time-independent magnetic field  

Science Conference Proceedings (OSTI)

A method is presented to calculate the spin relaxation times T{sub 1}, T{sub 2} due to a nonuniform magnetic field, and the linear-in-electric-field precession frequency shift {delta}{omega}{sub E} when an electric field is present, in the diffusion approximation for spins confined to a rectangular cell. It is found that the rectangular cell geometry admits of a general result for T{sub 1}, T{sub 2}, and {delta}{omega}{sub E} in terms of the spatial cosine-transform components of the magnetic field.

Clayton, Steven Michael [Los Alamos National Laboratory

2010-12-03T23:59:59.000Z

110

Time and Frequency News  

Science Conference Proceedings (OSTI)

... NIST/CU 'Star Comb' Joins Quest for Earthlike Planets Release Date: 03/06 ... New Calculations on Blackbody Energy Set the Stage for Clocks with ...

2010-05-24T23:59:59.000Z

111

FREQUENCY AND TIME  

Science Conference Proceedings (OSTI)

... Price 60cents. ... oil the hasi.; of need.' Key wottls: Rt-0adca.t of stanilard frequrni ... they commence at intervals of 5,000.000 cycles of the 5-MHz carrier. ...

2003-01-30T23:59:59.000Z

112

Understanding Time and Frequency  

Science Conference Proceedings (OSTI)

... from the liter of gasoline measured by the oil company's scale. ... to skipschoolin the afternoon.Theproblem was knowingwhen to come home, so that ...

2003-01-30T23:59:59.000Z

113

Linear and synchrosqueezed time-frequency representations revisited. Part I: Overview, standards of use, related issues and algorithms  

E-Print Network (OSTI)

Time-frequency representations (TFRs) of signals, such as windowed Fourier transform (WFT), wavelet transform (WT) and their synchrosqueezed variants (SWFT, SWT), provide powerful analysis tools. However, there are many important issues related to the practical use of TFRs that need to be clarified. Here we present a thorough review of these TFRs, summarizing all theoretical, practical and numerical aspects of their use, reconsidering some conventions and introducing new concepts and procedures. The purposes of this work are: (i) to provide a consistent overview of the computation, properties, and use of the (S)WFT/(S)WT methods; (ii) to establish general standards related to their use, both theoretical and practical; and (iii) to provide clean and optimized algorithms and MatLab codes, appropriate for any window or wavelet.

Iatsenko, Dmytro; Stefanovska, Aneta

2013-01-01T23:59:59.000Z

114

Fuzzy multi-objective production/distribution planning decisions with multi-product and multi-time period in a supply chain  

Science Conference Proceedings (OSTI)

This work develops a fuzzy multi-objective linear programming (FMOLP) model with piecewise linear membership function to solve integrated multi-product and multi-time period production/distribution planning decisions (PDPD) problems with fuzzy objectives. ... Keywords: Fuzzy multi-objective linear programming, Fuzzy sets, Production/distribution planning decisions, Supply chain management

Tien-Fu Liang

2008-10-01T23:59:59.000Z

115

VARIABLE TIME-INTERVAL GENERATOR  

DOE Patents (OSTI)

This patent relates to a pulse generator and more particularly to a time interval generator wherein the time interval between pulses is precisely determined. The variable time generator comprises two oscillators with one having a variable frequency output and the other a fixed frequency output. A frequency divider is connected to the variable oscillator for dividing its frequency by a selected factor and a counter is used for counting the periods of the fixed oscillator occurring during a cycle of the divided frequency of the variable oscillator. This defines the period of the variable oscillator in terms of that of the fixed oscillator. A circuit is provided for selecting as a time interval a predetermined number of periods of the variable oscillator. The output of the generator consists of a first pulse produced by a trigger circuit at the start of the time interval and a second pulse marking the end of the time interval produced by the same trigger circuit.

Gross, J.E.

1959-10-31T23:59:59.000Z

116

Super Gabor frames on discrete periodic sets  

Science Conference Proceedings (OSTI)

Due to its potential applications in multiplexing techniques such as time division multiple access and frequency division multiple access, superframe has interested some mathematicians and engineering specialists. In this paper, we investigate super ... Keywords: 42C40, Discrete Zak transform, Discrete periodic sets, Gabor dual, Super Gabor frame, Superframe

Yun-Zhang Li; Qiao-Fang Lian

2013-05-01T23:59:59.000Z

117

Active period Sleep period Active period Sleep period Fig. 1. Sleep-awake cycles of SMAC.  

E-Print Network (OSTI)

A cycle Active period Sleep period Active period Sleep period SYNC usage DATA usage time Fig. 1 Yang and Wendi Heinzelman Dept. of Electrical and Computer Engineering, University of Rochester duty cycles. Since a smaller duty cycle leads to a longer network lifetime but lower throughput

Heinzelman, Wendi

118

Method of detecting system function by measuring frequency response  

Science Conference Proceedings (OSTI)

Real-time battery impedance spectrum is acquired using a one-time record. Fast Summation Transformation (FST) is a parallel method of acquiring a real-time battery impedance spectrum using a one-time record that enables battery diagnostics. An excitation current to a battery is a sum of equal amplitude sine waves of frequencies that are octave harmonics spread over a range of interest. A sample frequency is also octave and harmonically related to all frequencies in the sum. The time profile of this signal has a duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known and octave and harmonically related, a simple algorithm, FST, processes the time record by rectifying relative to the sine and cosine of each frequency. Another algorithm yields real and imaginary components for each frequency.

Morrison, John L. (Butte, MT); Morrison, William H. (Manchester, CT); Christophersen, Jon P. (Idaho Falls, ID)

2012-04-03T23:59:59.000Z

119

Stochastic Resonance in a Periodically Modulated Dissipative Nuclear Dynamics  

E-Print Network (OSTI)

A fission decay of highly excited periodically driven compound nuclei is considered in the framework of Langevin approach. We have used residual-time distribution (RTD) as the tool for studying of dynamic features in a presence of periodic perturbation. The structure of RTD essentially depends on the relation between Kramers decay rate and the frequency of the periodic perturbation. In particular, intensity of the first peak in RTD has a sharp maximum at certain nuclear temperature depending on the frequency of the periodic perturbation. This maximum should be considered as first-hand manifestation of stochastic resonance in nuclear dynamics.

V. P. Berezovoj; Yu. L. Bolotin; O. P. Dzyubak; V. V. Yanovsky; A. V. Zhiglo

2001-01-22T23:59:59.000Z

120

We study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film by using time  

E-Print Network (OSTI)

an applied magnetic field, and a time varying transport current that does not induce any flux inside the thinWe study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film of flux distributions. We find that the total current distribution can be described as the superposition

Lewis, Robert Michael

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Estimating damping effectiveness of BPA`s thyristor controlled series capacitor by applying time and frequency domain methods to measured response  

Science Conference Proceedings (OSTI)

Recently, a 500-kV thyristor controlled series capacitor (TCSC) was installed in the Bonneville Power Administration system in the northwestern US. Extensive field testing has included modulation experiments to determine the effect of the TCSC on low-frequency oscillations. This paper discusses modulation procedures, analysis methods, and results for estimating the damping effectiveness of the TCSC. Modulation methods include driving the TCSC with step and random noise, and analysis techniques include time (Prony analysis) and frequency-domain identification. Results indicate that: (1) the TCSC can have significant impact on system dynamics; and (2) under a very small feedback gain, the TCSC provides measurable added damping.

Trudnowski, D.J.; Donnelly, M.K.; Hauer, J.F. [Pacific Northwest Lab., Richland, WA (United States)

1996-05-01T23:59:59.000Z

122

Busy period, time of the first loss of a customer and the number of customers in $ M^{\\varkappa}|G^{\\delta}|1|B$  

E-Print Network (OSTI)

A two-sided exit problem is solved for a difference of a compound Poisson process and a compound renewal process. More precisely, the Laplace transforms of the joint distribution of the first exit time, the value of the overshoot and the value of a linear component at this instant are found. Further, we study the process reflected in its supremum. We determine the main two-boundary characteristics of the process reflected in its supremum. These results are then applied for studying the $ M^{\\varkappa}|G^{\\delta}|1|B$ system. We derive the distribution of a busy period and the numbers of customers in the system in transient and stationary regimes. The advantage is that these results are in a closed form, in terms of resolvent sequences of the process.

Kadankova, Tetyana; Veraverbeke, Noel

2011-01-01T23:59:59.000Z

123

Method of detecting system function by measuring frequency response  

Science Conference Proceedings (OSTI)

Methods of rapidly measuring an impedance spectrum of an energy storage device in-situ over a limited number of logarithmically distributed frequencies are described. An energy storage device is excited with a known input signal, and a response is measured to ascertain the impedance spectrum. An excitation signal is a limited time duration sum-of-sines consisting of a select number of frequencies. In one embodiment, magnitude and phase of each frequency of interest within the sum-of-sines is identified when the selected frequencies and sample rate are logarithmic integer steps greater than two. This technique requires a measurement with a duration of one period of the lowest frequency. In another embodiment, where selected frequencies are distributed in octave steps, the impedance spectrum can be determined using a captured time record that is reduced to a half-period of the lowest frequency.

Morrison, John L.; Morrison, William H.; Christophersen, Jon P.; Motloch, Chester G.

2013-01-08T23:59:59.000Z

124

A Real-Time and Offline Quality Control Methodology for SeaSonde High-Frequency Radar Currents  

Science Conference Proceedings (OSTI)

A near-real-time and offline quality control methodology for SeaSonde systems is proposed. It is applied on radial current maps and is based on the determination of the signal-to-noise ratio (SNR) values of the Doppler lines that contribute to the ...

Simone Cosoli; Giorgio Bolzon; Andrea Mazzoldi

2012-09-01T23:59:59.000Z

125

The Timing and Frequency of Complications After Peripheral Percutaneous Transluminal Angioplasty and Iliac Stenting: Is a Change from Inpatient to Outpatient Therapy Feasible?  

SciTech Connect

Purpose: A prospective study was performed to assess the frequency and timing of complications after transluminal angioplasty and stent placement with a view to changing our practice and performing these procedures on an outpatient basis.Method: A total of 266 angioplasties and 51 stent deployments were attempted on 240 consecutive patients. Immediate complications were documented by the radiologists. The timing and nature of any complications during and beyond the first 24 hr were reported by the vascular surgeons.Results: There were 14 complications in 240 patients, giving a complication rate of 4.8% per vessel segment dilated. There were five major and nine minor complications. Eighty-six percent of complications were evident before the patient had left the angiography suite. All complications were evident within 4.5 hr of the procedure.Conclusion: The timing of complications suggests it would be reasonable to perform percutaneous transluminal angioplasties and iliac stenting on an outpatient basis in suitable patients.

Burns, Briony J. [Department of Radiology, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU (United Kingdom); Phillips, Andrea J. [Department of Radiology, Royal United Hospital NHS Trust, Combe Park, Bath BA1 3NG (United Kingdom); Fox, Anthony [Department of Surgery, Royal Shrewsbury Hospital, Mytton Oak Road, Shrewsbury SY3 8XQ (United Kingdom); Boardman, Phillip; Phillips-Hughes, Jane [Department of Radiology, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU (United Kingdom)

2000-11-15T23:59:59.000Z

126

First results from plasma density measurements in the FTU tokamak by means of a two-frequency pulsed time-of-flight refractometer  

SciTech Connect

A pulsed time-of-flight refractometer was developed and tested to determine the mean plasma density in the T-11M tokamak by measuring the propagation time of nanosecond microwave pulses in plasma. Later, it was also proposed to use such an instrument to measure and control the mean plasma density in the ITER tokamak by probing the plasma with an extraordinary wave, the electric field of which is perpendicular to the magnetic field in plasma, in the transparency window at frequencies of 50-100 GHz. To avoid the effect of the density profile shape on the measurement results in the nonlinear mode of refractometer operation (near the cutoff), a system operating at two different probing frequencies was developed and tested. Such a system provides two values of the time delay, which can be used to estimate the peaking factor of the density distribution {alpha} and correctly determine the linear density Left-Pointing-Angle-Bracket Nl Right-Pointing-Angle-Bracket , regardless of the density profile (assuming a smooth density profile of the form of N({rho}) = N(0)(1 - {rho}{sup 2}){sup {alpha}}, where N(0) is the central plasma density and {rho} = r/a is the normalized plasma radius). The first experiments on density measurements in the FTU tokamak performed with this refractometer are described, and results from these experiments are presented. The formation of a thin dense plasma layer in the zone of a strong magnetic field (the so-called MARFE layer) at a relatively low (for FTU) plasma density of {approx}6 Multiplication-Sign 10{sup 19} m{sup -3} was detected. The thickness of this layer, determined from the refractometry data, agrees well with the data obtained using a digital camera.

Petrov, V. G.; Malyshev, A. Yu.; Markov, V. K.; Petrov, A. A. [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Avino, F.; Angelis, R. de; Tudisco, O. [ENEA-UT Fusione Centro Ricerche Frascati (Italy)

2012-04-15T23:59:59.000Z

127

NIST Time and Frequency Services  

Science Conference Proceedings (OSTI)

... The broadcast power for WWVB was increased in 1999 from about 10 kilowatts to 50 kilowatts, providing much improved signal strength and ...

2010-10-05T23:59:59.000Z

128

NIST Time and Frequency Services  

Science Conference Proceedings (OSTI)

... 14 The Mid-latitude K-index at 1500 UTC on 08 November was 3. 2 Space weather for the past 24 hours has been severe. Solar radiation storm(s ...

2013-06-17T23:59:59.000Z

129

primary frequency standards  

Science Conference Proceedings (OSTI)

NIST-F1 Cesium Fountain Atomic Clock The Primary Time and Frequency Standard for the United States. NIST-F1, the nation's ...

2013-02-04T23:59:59.000Z

130

Specific features in building hardware-software complexes operating in real-time: An example of test rig used in periodic tests of reducers  

Science Conference Proceedings (OSTI)

Test rig for periodic tests of reducers is involved as an example to discuss specific features in building automatic test systems (ATS); the test rig is designed at ZAO NPP MIKS Engineering. A certain approach to ATS design based on adaptation of universal ...

A. A. Urakov; M. A. Rylov; D. S. Shutov; P. G. Dorofeev

2011-05-01T23:59:59.000Z

131

Observing Long-Period Fluctuations of Surface Winds in the Tropical Pacific: Initial Results from Island Data  

Science Conference Proceedings (OSTI)

The utility of studying low-frequency surface weather phenomena with long time series of meteorological data from tropical Pacific islands is demonstrated. The wind stress changes associated with El Nińo events in the period 1950–78 are examined ...

D. S. Luther; D. E. Harrison

1984-02-01T23:59:59.000Z

132

Analyzing the Impacts of Frequency and Severity of Forest Fire on the Recovery of Disturbed Forest using Landsat Time Series and EO-1 Hyperion in the Southern Brazilian Amazon  

Science Conference Proceedings (OSTI)

Estimation of fire impacts and forest recovery using remote sensing is difficult because of the heterogeneity of fire history (frequency, severity, and time since last fire) across burned forest landscapes. The authors analyzed impacts of fire ...

Izaya Numata; Mark A. Cochrane; Lęnio S. Galvăo

2011-05-01T23:59:59.000Z

133

Alongshore Wind Forcing of Coastal Sea Level as a Function of Frequency  

Science Conference Proceedings (OSTI)

The amplitude of the frequency response function between coastal alongshore wind stress and adjusted sea level anomalies along the west coast of the United States increases linearly as a function of the logarithm (log10) of the period for time ...

Holly F. Ryan; Marlene A. Noble

2006-11-01T23:59:59.000Z

134

Stochastic resonance in a periodically modulated dissipative nuclear dynamics  

SciTech Connect

A fission decay of highly excited periodically driven compound nuclei is considered in the framework of Langevin approach. The authors have used residual-time distribution (RTD) as the tool for studying of dynamic features in a presence of periodic perturbation. The structure of RTD essentially depends on the relation between Kramers decay rate and the frequency {omega} of the periodic perturbation. In particular, intensity of the first peak in RTD has a sharp maximum at certain nuclear temperature depending on {omega}. This maximum should be considered as first-hand manifestation of stochastic resonance in nuclear dynamics.

Berezovoy, V.P. [and others

2001-02-01T23:59:59.000Z

135

Stochastic Resonance in a Periodically Modulated Dissipative Nuclear Dynamics  

E-Print Network (OSTI)

A fission decay of highly excited periodically driven compound nuclei is considered in the framework of Langevin approach. We have used residual-time distribution (RTD) as the tool for studying of dynamic features in a presence of periodic perturbation. The structure of RTD essentially depends on the relation between Kramers decay rate and the frequency ? of the periodic perturbation. In particular, intensity of the first peak in RTD has a sharp maximum at certain nuclear temperature depending on ?. This maximum should be considered as first-hand manifestation of stochastic resonance in nuclear dynamics. 1

unknown authors

2008-01-01T23:59:59.000Z

136

Numerical Simulation and Laboratory Testing of Time-Frequency MUSIC Beamforming for Identifying Continuous and Impulsive Ground Targets from a Mobile Aerial Platform  

E-Print Network (OSTI)

When a microphone array is mounted on a mobile aerial platform, such as an unmanned aerial vehicle (UAV), most existing beamforming methods cannot be used to adequately identify continuous and impulsive ground. Here, numerical simulation results and laboratory experiments are presented that validate a proposed time-frequency beamforming method based on the Multiple Signal Classification (MUSIC) algorithm to detect these acoustic sources from a mobile aerial platform. In the numerical simulations three parameters were varied to test the proposed algorithm’s location estimation performance: 1) the acoustic excitation types; 2) the moving receiver’s simulated flight conditions; and 3) the number of acoustic sources. Also, a distance and angle error analysis was done to quantify the proposed algorithm’s source location estimation accuracy when considering microphone positioning uncertainty. For experimental validation, three laboratory experiments were conducted. Source location estimations were done for: a 600 Hz sine source, a banded white noise source between 700-800 Hz, and a composite source combined simultaneously with both the sine and banded white noise sources. The proposed algorithm accurately estimates the simulated monopole’s location coordinates no matter the excitation type or simulated trajectory. When considering simultaneously-excited, multiple monopoles at high altitudes, e.g. 50 m, the proposed algorithm had no error when estimating the source’s locations. Finally, a distance and angle error analysis exposed how relatively small microphone location error, e.g. 1 cm maximum error, can propagate into large averaged distance error of about 10 m in the far-field for all monopole excitation types. For all simulations, however, the averaged absolute angle error remained small, e.g. less than 4 degrees, even when considering a 5 cm maximum microphone location error. For the laboratory experiments, the sine source had averaged distance and absolute angle errors of 0.9 m and 14.07 degrees from the source’s true location, respectively. Similarly, the banded white noise source’s averaged distance and absolute angle errors were 1.9 m and 47.14 degrees; and lastly, the averaged distance and absolute angle errors of 0.78 m and 8.14 degrees resulted when both the sources were simultaneously excited.

Silva, Ramon Alejandro

2013-05-01T23:59:59.000Z

137

Precise Measurements of the Kilohertz Quasi-Periodic Oscillations in 4U 1728-34  

E-Print Network (OSTI)

We have analyzed seventeen observations of the low-mass X-ray binary and atoll source 4U 1728-34, carried out by the Rossi X-ray Timing Explorer in 1996 and 1997. We obtain precise measurements of the frequencies of the two simultaneous kilohertz quasi-periodic oscillations (kHz QPOs) in this source. We show that the frequency separation between the two QPO, $\\Delta \

Mariano Mendez; Michiel van der Klis

1999-03-19T23:59:59.000Z

138

A Precipitation Climatology of 5-Day Periods  

Science Conference Proceedings (OSTI)

A precipitation climatology has been developed for the relative frequencies of zero, one, or two or more days with measurable precipitation within 5-day periods. In addition, the distribution of precipitation amounts is given for the one wet day ...

E. S. Epstein; A. G. Barnston

1990-02-01T23:59:59.000Z

139

Gene Frequency  

NLE Websites -- All DOE Office Websites (Extended Search)

Gene Frequency Gene Frequency Name: donna Location: N/A Country: N/A Date: N/A Question: If six fingers is a dominant human trait why do we have only five? Replies: This is simple. There are just not many genes in the human population for six fingers. Steve Sample Look in any high school biology book for what is known as Hardy-Weinberg equilibrium. These two scientists (separately) said that gene frequencies do not change much unless something in the environment selects them over other genes. In other words, unless 6 fingers somehow becomes an advantage, and five-fingered people have less of an advantage, the frequency of six fingered people in the population will not necessarily increase. This is the same reason that recessive traits don't disappear from the population. Also, six fingers is not considered attractive and they may not get as many mates. Also, more people are born with six fingers than you might imagine but just have them amputated shortly after birth.

140

High frequency breakdown voltage  

SciTech Connect

This report contains information about the effect of frequency on the breakdown voltage of an air gap at standard pressure and temperature, 76 mm Hg and O{degrees}C, respectively. The frequencies of interest are 47 MHz and 60 MHz. Additionally, the breakdown in vacuum is briefly considered. The breakdown mechanism is explained on the basis of collision and ionization. The presence of the positive ions produced by ionization enhances the field in the gap, and thus determines the breakdown. When a low-frequency voltage is applied across the gap, the breakdown mechanism is the same as that caused by the DC or static voltage. However, when the frequency exceeds the first critical value f{sub c}, the positive ions are trapped in the gap, increasing the field considerably. This makes the breakdown occur earlier; in other words, the breakdown voltage is lowered. As the frequency increases two decades or more, the second critical frequency, f{sub ce}, is reached. This time the electrons start being trapped in the gap. Those electrons that travel multiple times across the gap before reaching the positive electrode result in an enormous number of electrons and positive ions being present in the gap. The result is a further decrease of the breakdown voltage. However, increasing the frequency does not decrease the breakdown voltage correspondingly. In fact, the associated breakdown field intensity is almost constant (about 29 kV/cm).The reason is that the recombination rate increases and counterbalances the production rate, thus reducing the effect of the positive ions` concentration in the gap. The theory of collision and ionization does not apply to the breakdown in vacuum. It seems that the breakdown in vacuum is primarily determined by the irregularities on the surfaces of the electrodes. Therefore, the effect of frequency on the breakdown, if any, is of secondary importance.

Chu, Thanh Duy

1992-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

A Framework of Concurrent Task Scheduling and Dynamic Voltage and Frequency Scaling in Real-Time Embedded Systems with Energy Harvesting  

E-Print Network (OSTI)

harvesting module is comprised of a Photovoltaic (PV) panel for harvesting energy and a supercapacitor panel, state-of- charge management for the supercapacitor, and energy-harvesting- aware real-time task-leakage of the supercapacitor, and power losses in voltage converters, employs a cascaded feedback control structure

Pedram, Massoud

142

Low-Frequency Variability in Shallow-Water Models of the Wind-Driven Ocean Circulation. Part II: Time-Dependent Solutions  

Science Conference Proceedings (OSTI)

The time-dependent wind-driven ocean circulation is investigated for both a rectangular and a North Atlantic–shaped basin. Multiple steady states in a 2˝-layer shallow-water model and their dependence on various parameters and other model ...

Eric Simonnet; Michael Ghil; Kayo Ide; Roger Temam; Shouhong Wang

2003-04-01T23:59:59.000Z

143

Definition: Time Error | Open Energy Information  

Open Energy Info (EERE)

of Frequency Error over a given period.1 Related Terms Interconnection, sustainability, frequency error, smart grid References Glossary of Terms Used in Reliability...

144

Risk-averse periodic preventive maintenance optimization.  

E-Print Network (OSTI)

??We consider a class of periodic preventive maintenance (PM) optimization problems, for a single piece of equipment that deteriorates with time or use, and can… (more)

Singh, Inderjeet,1978-

2011-01-01T23:59:59.000Z

145

Down-hole periodic seismic generator  

DOE Patents (OSTI)

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.

Hardee, H.C.; Hills, R.G.; Striker, R.P.

1982-10-28T23:59:59.000Z

146

NIST Time and Frequency Division 1995 - Technical ...  

Science Conference Proceedings (OSTI)

... what can be called "quantum projection noise." In ... the excitation to higher-energy coherent states ... in electronics applications demanding the lowest ...

147

News in PML - Time and Frequency  

Science Conference Proceedings (OSTI)

... NIST/CU 'Star Comb' Joins Quest for Earthlike Planets. ... Quantum Hot Potato: NIST Researchers Entice Two Atoms to Swap Smallest Energy Units. ...

2010-10-05T23:59:59.000Z

148

NBS FREQUENCY AND TIME BROADCAST SERVICES  

Science Conference Proceedings (OSTI)

... CR SMITH, Secretary ... observed solar or geophysical events. ... FLARES expected PROTON FLARE expected MAGSTORM expected sss (... ...

2003-01-30T23:59:59.000Z

149

SIM Time and Frequency Working Group  

Science Conference Proceedings (OSTI)

... National Web Clocks (outside SIM). China; Germany; Italy; Japan; Malaysia; Singapore; Taiwan. CMC Related Files. Blank CMC form (Excel File). ...

150

SIM Time and Frequency Working Group  

Science Conference Proceedings (OSTI)

... IBMETRO. Report from Canada, John Bernard, NRC. Report from Chile, Daniel Mayorga, University of Concepcion. Report ...

151

NIST Time and Frequency Publication Database  

Science Conference Proceedings (OSTI)

... by entering at least one search term in the submission form below, and then clicking the submit button. You only need to enter partial terms, such as ...

152

NIST Time and Frequency Division 2000 - Technical ...  

Science Conference Proceedings (OSTI)

... about 1.5 µK) results in a loss of approximately ... the system might operate at a power as low ... to assure efficient data transfer between network nodes. ...

153

Chapter 17: Fundamentals of Time and Frequency  

Science Conference Proceedings (OSTI)

... in length, and the atoms travel at velocities of >100 m/s inside the tube. ... contains the year, day of year, hour, minute, second, and flags that indicate ...

2003-04-18T23:59:59.000Z

154

Fundamental Concepts of Time and Frequency Metrology  

Science Conference Proceedings (OSTI)

... the length of the mean solar day and was called the mean solar second. ... standard deviation from the mean is pointless if the data has a trend, or is ...

2012-10-19T23:59:59.000Z

155

ACCURATE TIME AND FREQUENCY TRANSFER DURING ...  

Science Conference Proceedings (OSTI)

... Fig. 20 is also from Klobuchar's paper and shows theactualverticalelec tron contentat H amilton , MA lookingtowardsthe ATS-3 ...

2001-10-04T23:59:59.000Z

156

MEMS technology for timing and frequency control  

E-Print Network (OSTI)

physics pack- 10 7 using atomic ages, which so far havescale atomic clock—low-power physics pack- age,” in Proc.

Nguyen, CTC

2007-01-01T23:59:59.000Z

157

Time and Frequency Division - 1997 Technical Highlights  

Science Conference Proceedings (OSTI)

... have locked a microwave source to the ions' ground state hyperfine ... pseudo-random GPS clock variations associated with Selective Availability ( ...

158

Time and Frequency: Measurements and Applications  

Science Conference Proceedings (OSTI)

... a TCXO (temperature controlled quartz oscillator), or an OCXO (oven controlled crystal ... was defined based on the length of the mean solar day. ...

2008-01-22T23:59:59.000Z

159

Time and Frequency: Measurements and Applications  

Science Conference Proceedings (OSTI)

... a TCXO (temperature controlled quartz oscillator), or an OCXO (oven controlled crystal ... was defined based on the length of the mean solar day and ...

2010-02-25T23:59:59.000Z

160

NIST Time and Frequency Publication Database  

Science Conference Proceedings (OSTI)

... You can search for publications by entering at least ... You only need to enter partial terms, such as the ... Words can be entered as either upper or lower ...

2010-10-05T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

NIST Time and Frequency Division 1999 - Technical ...  

Science Conference Proceedings (OSTI)

... chemical reactions with the background gas prevented long ... so widely separated, a natural part of ... V. Udin of Novosibirsk State University in Russia. ...

162

Method of electric field flow fractionation wherein the polarity of the electric field is periodically reversed  

DOE Patents (OSTI)

A novel method of electric field flow fractionation for separating solute molecules from a carrier solution is disclosed. The method of the invention utilizes an electric field that is periodically reversed in polarity, in a time-dependent, wave-like manner. The parameters of the waveform, including amplitude, frequency and wave shape may be varied to optimize separation of solute species. The waveform may further include discontinuities to enhance separation.

Stevens, Fred J. (Naperville, IL)

1992-01-01T23:59:59.000Z

163

Low-Pass Filters to Suppress Inertial and Tidal Frequencies  

Science Conference Proceedings (OSTI)

A systematic way is given to design digital filters which allow clear separation of signals with periods of a few days from noise of higher frequency, particularly tidal and inertial. Several examples are given which pass little high-frequency ...

Rory O. R. Y. Thompson

1983-06-01T23:59:59.000Z

164

Budget Period 1  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Budget Period 1 Budget Period 1 Budget Period 2 Budget Period 3 0.0% 0.0% 0.0% PMC123.1 - Budget Justification for SF 424A Budget 0 Additional Explanations/Comments (as necessary) *IMPORTANT: In the space provided below (or as an attachment) provide a complete explanation and the full calculations used to derive the total indirect costs. If the total indirect costs are a cumulative amount of more than one calculation or rate application, the explanation and calculations should identify all rates used, along with the base they were applied to (and how the base was derived), and a total for each (along with grand total). The rates and how they are applied should not be averaged to get one indirect cost percentage. NOTE: The indirect rate should be applied to both the Federal Share and Recipient Cost Share.

165

Periodic orbit spectrum in terms of Ruelle--Pollicott resonances  

E-Print Network (OSTI)

Fully chaotic Hamiltonian systems possess an infinite number of classical solutions which are periodic, e.g. a trajectory ``p'' returns to its initial conditions after some fixed time tau_p. Our aim is to investigate the spectrum tau_1, tau_2, ... of periods of the periodic orbits. An explicit formula for the density rho(tau) = sum_p delta (tau - tau_p) is derived in terms of the eigenvalues of the classical evolution operator. The density is naturally decomposed into a smooth part plus an interferent sum over oscillatory terms. The frequencies of the oscillatory terms are given by the imaginary part of the complex eigenvalues (Ruelle--Pollicott resonances). For large periods, corrections to the well--known exponential growth of the smooth part of the density are obtained. An alternative formula for rho(tau) in terms of the zeros and poles of the Ruelle zeta function is also discussed. The results are illustrated with the geodesic motion in billiards of constant negative curvature. Connections with the statistical properties of the corresponding quantum eigenvalues, random matrix theory and discrete maps are also considered. In particular, a random matrix conjecture is proposed for the eigenvalues of the classical evolution operator of chaotic billiards.

P. Leboeuf

2004-06-18T23:59:59.000Z

166

Periodic load balancing  

Science Conference Proceedings (OSTI)

Multiprocessor load balancing aims to improve performance by moving jobs from highly loaded processors to more lightly loaded processors. Some schemes allow only migration of new jobs upon arrival, while other schemes allow migration of ... Keywords: heavy traffic diffusion approximations, load balancing, periodic load balancing, reflected Brownian motion, resource sharing, transient behavior

Gísli Hjálmtýsson; Ward Whitt

1998-06-01T23:59:59.000Z

167

Analysis of periodically-forced turbulence in the rapid distortion limit  

E-Print Network (OSTI)

Rapid Distortion Theory is used to perform calculations of unsteadily-forced initially isotropic turbulence so that the physics of such flows can be better understood. The results of these calculations show that there are three distinct regimes of physical behavior for the kind of turbulence that we are considering: (1) turbulence that is forced at a relatively low frequency in which the kinetic energy settles down to a constant value at later times, (2) turbulence that is forced at a slightly higher frequency in which the kinetic energy value oscillates for a time, but then increases dramatically, and (3) turbulence that is forced at a relatively high frequency in which the kinetic energy evolution exhibits a periodic behavior. To better understand the role of the rapid pressure-strain correlation, these results are also compared to Inertial Model results for the same set of forcing frequencies. The results of this comparison show that the rapid pressure plays a key role in determining the stability characteristics of unsteadily-forced turbulence. The evolution equation for kinetic energy is then used to propose a model that describes the behavior approximately in terms of a time lag between applied mean strain and the Reynolds stress. This model suggests that the different responses under the different frequencies of forcing correspond to different stress-strain time lags. Overall, then the results indicate that rapid pressure serves to create a time lag between applied stress and strain, and it is the extent of this time lag that causes turbulence to respond differently under various frequencies of forcing.

O'Neil, Joshua Robert

2004-12-01T23:59:59.000Z

168

Effective Rate Period  

NLE Websites -- All DOE Office Websites (Extended Search)

Fiscal Year 2014 Fiscal Year 2014 Effective Rate Period As of Beginning of the FY 10/01/2013 - 09/30/2014 Mid-Year Changes (if applicable) 10/01/2013 - 09/30/2014 Power Rates Annual Revenue Requirement Rate Schedule Power Revenue Requirement $73,441,557 CV-F13 Base Resource Revenue Requirement $69,585,875 First Preference Revenue Requirement $3,855,682

169

Coherence-based multivariate analysis of high frequency stock market values  

E-Print Network (OSTI)

The paper tackles the problem of deriving a topological structure among stock prices from high frequency historical values. Similar studies using low frequency data have already provided valuable insights. However, in those cases data need to be collected for a longer period and then they have to be detrended. An effective technique based on averaging a metric function on short subperiods of the observation horizon is suggested. Since a standard correlation-based metric is not capable of catching dependencies at different time instants, it is not expected to perform the best when dealing with high frequency data. Hence, the choice of a more suitable metric is discussed. In particular, a coherence-based metric is proposed, for it is able to detect any possible linear relation between two times series, even at different time instants. The averaging technique is employed to analyze a set of 100 high volume stocks of the New York Stock Exchange, observed during March 2008.

Donatello Materassi; Giacomo Innocenti

2008-05-18T23:59:59.000Z

170

Analysis of Heart Rate Variability Using Time-Varying Filtering of Heart Transplanted Patients  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

171

STELLAR PULSATIONS AND PERIOD CHANGES IN THE SX PHOENICIS STAR XX CYGNI  

SciTech Connect

Time-series photometric observations were made for the SX Phoenicis star XX Cyg between 2007 and 2011 at the Xinglong Station of National Astronomical Observatories of China. With the light curves derived from the new observations, we do not detect any secondary maximum in the descending portion of the light curves of XX Cyg, as reported in some previous work. Frequency analysis of the light curves confirms a fundamental frequency f{sub 0} = 7.4148 cycles day{sup -1} and up to 19 harmonics, 11 of which are newly detected. However, no secondary mode of pulsation is detected from the light curves. The O-C diagram, produced from 46 newly determined times of maximum light combined with those derived from the literature, reveals a continuous period increase with the rate of (1/P)(dP/dt) = 1.19(13) Multiplication-Sign 10{sup -8} yr{sup -1}. Theoretical rates of period change due to the stellar evolution were calculated with a modeling code. The result shows that the observed rate of period change is fully consistent with period change caused by evolutionary behavior predicted by standard theoretical models.

Yang, X. H.; Fu, J. N.; Zha, Q., E-mail: jnfu@bnu.edu.cn [Astronomy Department, Beijing Normal University, Beijing 100875 (China)

2012-10-01T23:59:59.000Z

172

Testing for Change in the Frequency of El Nińo Events  

Science Conference Proceedings (OSTI)

This note describes and applies a test for trend in the frequency of El Nińo events over the period 1525–1987. Although there appears to have been a significant increase in frequency over this period, this result is consistent with an overall ...

Andrew R. Solow

1995-10-01T23:59:59.000Z

173

On occult period maps  

E-Print Network (OSTI)

We consider the "occult" period maps into ball quotients which exist for the moduli spaces of cubic surfaces, cubic threefolds, non-hyperelliptic curves of genus three and four. These were constructed in the work of Allcock/Carlson/Toledo, Looijenga/Swierstra, and Kondo. We interpret these maps as morphisms into moduli spaces of polarized abelian varieties of Picard type, and show that these morphisms, whose initial construction is transcendental, are defined over the natural field of definition of the spaces involved. This paper is extracted from section 15 of our paper arXiv:0912.3758, and differs from it only in some points of exposition.

Kudla, Stephen

2012-01-01T23:59:59.000Z

174

NONPARAMETRIC BAYESIAN ESTIMATION OF PERIODIC LIGHT CURVES  

SciTech Connect

Many astronomical phenomena exhibit patterns that have periodic behavior. An important step when analyzing data from such processes is the problem of identifying the period: estimating the period of a periodic function based on noisy observations made at irregularly spaced time points. This problem is still a difficult challenge despite extensive study in different disciplines. This paper makes several contributions toward solving this problem. First, we present a nonparametric Bayesian model for period finding, based on Gaussian Processes (GPs), that does not make assumptions on the shape of the periodic function. As our experiments demonstrate, the new model leads to significantly better results in period estimation especially when the light curve does not exhibit sinusoidal shape. Second, we develop a new algorithm for parameter optimization for GP which is useful when the likelihood function is very sensitive to the parameters with numerous local minima, as in the case of period estimation. The algorithm combines gradient optimization with grid search and incorporates several mechanisms to overcome the high computational complexity of GP. Third, we develop a novel approach for using domain knowledge, in the form of a probabilistic generative model, and incorporate it into the period estimation algorithm. Experimental results validate our approach showing significant improvement over existing methods.

Wang Yuyang; Khardon, Roni [Department of Computer Science, Tufts University, Medford, MA (United States); Protopapas, Pavlos [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

2012-09-01T23:59:59.000Z

175

Multi-period optimization of pavement management systems  

E-Print Network (OSTI)

The purpose of this research is to develop a model and solution methodology for selecting and scheduling timely and cost-effective maintenance, rehabilitation, and reconstruction activities (M & R) for each pavement section in a highway network and allocating the funding levels through a finite multi-period horizon within the constraints imposed by budget availability in each period, frequency availability of activities, and specified minimum pavement quality requirements. M & R is defined as a chronological sequence of reconstruction, rehabilitation, and major/minor maintenance, including a "do nothing" activity. A procedure is developed for selecting an M & R activity for each pavement section in each period of a specified extended planning horizon. Each activity in the sequence consumes a known amount of capital and generates a known amount of effectiveness measured in pavement quality. The effectiveness of an activity is the expected value of the overall gains in pavement quality rating due to the activity performed on a highway network over an analysis period. It is assumed that the unused portion of the budget for one period can be carried over to subsequent periods. Dynamic Programming (DP) and Branch-and-Bound (B-and-B) approaches are combined to produce a hybrid algorithm for solving the problem under consideratioin. The algorithm is essentially a DP approach in the sense that the problem is divided into smaller subproblems corresponding to each single period problem. However, the idea of fathoming partial solutions that could not lead to an optimal solution is incorporated within the algorithm to reduce storage and computational requirements in the DP frame using the B-and-B approach. The imbedded-state approach is used to reduce a multi-dimensional DP to a one-dimensional DP. For bounding at each stage, the problem is relaxed in a Lagrangean fashion so that it separates into longest-path network model subproblems. The values of the Lagrangean multipliers are found by a subgradient optimization method, while the Ford-Bellman network algorithm is employed at each iteration of the subgradient optimization procedure to solve the longest-path network problem as well as to obtain an improved lower and upper bound. If the gap between lower and upper bound is sufficiently small, then we may choose to accept the best known solutions as being sufficiently close to optimal and terminate the algorithm rather than continue to the final stage.

Yoo, Jaewook

2005-05-01T23:59:59.000Z

176

Frequency Dependence of Rotor's Free Falling Acceleration and Inequality of Inertial and Gravity Masses  

E-Print Network (OSTI)

Results of measurements of free falling acceleration of a closed container with a rotor of a mechanical gyroscope placed inside it on the frequency of the rotor rotation are briefly described. Time of separate accelerations measurements is 40 ms, the period of sampling is from 0.5 up to 1.0 minute. In rotation's frequencies range of 20-400 Hz, the negative changes of free falling container acceleration prevail. On individual frequencies the "resonant" maxima and minima of acceleration are observed. The obtained data apparently contradict the equivalence principle of inertial and gravitating masses. The expediency of development of ballistic gravimetry of high time resolution with use of rotating or oscillating test bodies is noted.

Dmitriev, Alexander L

2011-01-01T23:59:59.000Z

177

Frequency Dependence of Rotor's Free Falling Acceleration and Inequality of Inertial and Gravity Masses  

E-Print Network (OSTI)

Results of measurements of free falling acceleration of a closed container with a rotor of a mechanical gyroscope placed inside it on the frequency of the rotor rotation are briefly described. Time of separate accelerations measurements is 40 ms, the period of sampling is from 0.5 up to 1.0 minute. In rotation's frequencies range of 20-400 Hz, the negative changes of free falling container acceleration prevail. On individual frequencies the "resonant" maxima and minima of acceleration are observed. The obtained data apparently contradict the equivalence principle of inertial and gravitating masses. The expediency of development of ballistic gravimetry of high time resolution with use of rotating or oscillating test bodies is noted.

Alexander L. Dmitriev

2011-01-24T23:59:59.000Z

178

Recommended Rest Frequencies  

Science Conference Proceedings (OSTI)

Return to Table of Contents NIST Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions. by Frank J. Lovas. ...

179

Gauge Interaction as Periodicity Modulation  

E-Print Network (OSTI)

The paper is devoted to a geometrical interpretation of gauge invariance in terms of the formalism of field theory in compact space-time dimensions [arXiv:0903.3680]. In this formalism, the kinematic information of an interacting elementary particle is encoded on the relativistic geometrodynamics of the boundary of the theory through local transformations of the underlying space-time coordinates. Therefore, gauge interaction is described as invariance of the theory under local deformations of the boundary, the resulting local variations of field solution are interpreted as internal transformations, and the internal symmetries of the gauge theory turn out to be related to corresponding local space-time symmetries. In the case of local infinitesimal isometric transformations, Maxwell's kinematics and gauge invariance are inferred directly from the variational principle. Furthermore we explicitly impose periodic conditions at the boundary of the theory as semi-classical quantization condition in order to investigate the quantum behavior of gauge interaction. In the abelian case the result is a remarkable formal correspondence with scalar QED.

Donatello Dolce

2011-10-03T23:59:59.000Z

180

Eastern Frequency Response Study  

Science Conference Proceedings (OSTI)

This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

Miller, N.W.; Shao, M.; Pajic, S.; D'Aquila, R.

2013-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

First observation of a transition between "parallel tracks" in the kHz QPO frequency vs. intensity diagram  

E-Print Network (OSTI)

Contrary to theoretical expectations, observations with the Rossi X-ray Timing Explorer (RXTE) show that in X-ray binaries timing properties are not uniquely correlated with X-ray luminosity. For instance, although the frequencies of the kilohertz quasi-periodic oscillations (kHz QPOs) correlate with X-ray flux on short (~few hours) time scales, on time scales longer than a day the QPO appears at more or less the same frequency, whereas the luminosity may be a factor of a few different. The result is a set of almost parallel tracks in a QPO frequency vs. X-ray flux plot. Despite the "parallel tracks" are a common phenomenon among kHz QPO sources, until now, after five years of observations with RXTE, not a single transition between two of these tracks had been seen. Here I present the first detection of such a transition, in 4U 1636-53.

Mariano Mendez

2002-07-12T23:59:59.000Z

182

Hitting Time Distributions in Financial Markets  

E-Print Network (OSTI)

We analyze the hitting time distributions of stock price returns in different time windows, characterized by different levels of noise present in the market. The study has been performed on two sets of data from US markets. The first one is composed by daily price of 1071 stocks trade for the 12-year period 1987-1998, the second one is composed by high frequency data for 100 stocks for the 4-year period 1995-1998. We compare the probability distribution obtained by our empirical analysis with those obtained from different models for stock market evolution. Specifically by focusing on the statistical properties of the hitting times to reach a barrier or a given threshold, we compare the probability density function (PDF) of three models, namely the geometric Brownian motion, the GARCH model and the Heston model with that obtained from real market data. We will present also some results of a generalized Heston model.

Valenti, D; Spagnolo, B; Bonanno, Giovanni; Spagnolo, Bernardo; Valenti, Davide

2006-01-01T23:59:59.000Z

183

Periodic equivalence ratio modulation method and apparatus for controlling combustion instability  

DOE Patents (OSTI)

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.

Richards, George A.; Janus, Michael C.; Griffith, Richard A.

1998-12-01T23:59:59.000Z

184

PERIODIC GLOW DISCHARGE REPORT  

NLE Websites -- All DOE Office Websites (Extended Search)

GLOW DISCHARGE REPORT GLOW DISCHARGE REPORT TIME: Jan 11 2014 11:29:09:000PM Power Supply ON/OFF Status OFF Power Supply Fault Status FAULT Power Supply Standby Status ON Power Supply Interlock Status NOT OK HV Power Resistors Status NORMAL Power Supply Voltage 52.00 Power Supply Current -71.00 Electrode 1 Voltage -15.00 Electrode 1 Current -79.00 Electrode 2 Voltage -14.00 Electrode 2 Current -70.00 ROSS 1 Status OPEN ROSS 2 Status OPEN ROSS 1 Common Line OPEN ROSS 2 Common Line OPEN IGBT1 Enable DISABLE IGBT2 Enable DISABLE

185

PERIODIC CRYO REPORT  

NLE Websites -- All DOE Office Websites (Extended Search)

CRYO REPORT CRYO REPORT TIME: Jan 11 2014 11:29:09:000PM LN2 tank pressure, psi 63.00 LN2 main tank level,inch 48.05 LN2 resv tank level,inch 179.00 Cryostat pressure, psi 0.01 LN2 sump level, inch 0.00 LN2 pump speed, rpm 0.27 LN2 pump pressure, psi 0.00 Scanner OK DIBORANE SYSTEM CRYBOR CONC1 OK CRYBOR CONC2 OK CRYBOR INST1 OK CRYBOR INST2 OK RESISTANCE COIL TEMPERATURES, deg C EF1U, deg C 34.66 EF1L 21.94 EF2U 26.93 EF2L 21.70 EF3U 41.54 EF3L 36.42 EFCU 18.28 EFCL 8.16

186

Periodicity estimation of Dynamic Textures  

Science Conference Proceedings (OSTI)

Dynamic Textures (DTs) are image sequences of natural events like fire, smoke, water etc., that possesses regular motion patterns. Periodicity is a widely used tool to analyse regular structures of periodic one dimensional signals as well as two dimensional ... Keywords: co-occurrence matrix, dynamic textures, image sequences, image texture analysis, motion patterns, natural events, periodicity estimation, temporal textures

Khalid Zaman Bijon; Ahmed Hasan; Ashfaqur Rahman; Manzur Murshed

2008-03-01T23:59:59.000Z

187

THE ORBITAL PERIOD OF SCORPIUS X-1  

Science Conference Proceedings (OSTI)

The orbital period of Sco X-1 was first identified by Gottlieb et al. While this has been confirmed on multiple occasions, this work, based on nearly a century of photographic data, has remained the reference in defining the system ephemeris ever since. It was, however, called into question when Vanderlinde et al. claimed to find the one-year alias of the historical period in RXTE/All-Sky Monitor data and suggested that this was the true period rather than that of Gottlieb et al. We examine data from the All Sky Automated Survey (ASAS) spanning 2001-2009. We confirm that the period of Gottlieb et al. is in fact the correct one, at least in the optical, with the one-year alias strongly rejected by these data. We also provide a modern time of minimum light based on the ASAS data.

Hynes, Robert I.; Britt, Christopher T., E-mail: rih@phys.lsu.edu [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803 (United States)

2012-08-10T23:59:59.000Z

188

The Harmonic and Sideband Structure of the Kilohertz Quasi-Periodic Oscillations in Sco X-1  

E-Print Network (OSTI)

We use data from the Rossi X-ray Timing Explorer to search for harmonics and sidebands of the two simultaneous kilohertz quasi-periodic oscillations (kHz QPOs) in Sco X-1. We do not detect any of these harmonics or sidebands, with 95% confidence upper limits to their power between ~ 1% and ~ 10% of the power of the upper kHz QPO. The oscillations produced at these frequencies may be attenuated in a scattering corona around the neutron star. We find that upper limits to the unattenuated power of some of the strongest theoretically predicted harmonics and sidebands are as low as ~ 2% of the unattenuated power of the high-frequency QPO in Sco X-1.

Mariano Mendez; Michiel van der Klis

2000-06-19T23:59:59.000Z

189

Energy-conserving feedback EDF scheduling for embedded systems with real-time constraints  

Science Conference Proceedings (OSTI)

Embedded systems have limited energy resources. Hence, they should conserve these resources to extend their period of operation. Recently, dynamic frequency scaling (DFS) and dynamic voltage scaling (DVS) have been added to a various embedded processors ... Keywords: dynamic voltage scaling, real-time systems, scheduling

Ajay Dudani; Frank Mueller; Yifan Zhu

2002-07-01T23:59:59.000Z

190

All-sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data  

E-Print Network (OSTI)

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.

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

191

Stabilized radio frequency quadrupole  

DOE Patents (OSTI)

Disclosed is a long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator. 5 figs.

Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

1984-12-25T23:59:59.000Z

192

Estimating frequency of change  

Science Conference Proceedings (OSTI)

Many online data sources are updated autonomously and independently. In this article, we make the case for estimating the change frequency of data to improve Web crawlers, Web caches and to help data mining. We first identify various scenarios, where ... Keywords: Change frequency estimation, Poisson process

Junghoo Cho; Hector Garcia-Molina

2003-08-01T23:59:59.000Z

193

Microfabricated ion frequency standard  

DOE Patents (OSTI)

A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

Schwindt, Peter (Albuquerque, NM); Biedermann, Grant (Albuquerque, NM); Blain, Matthew G. (Albuquerque, NM); Stick, Daniel L. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM); Olsson, III, Roy H. (Albuquerque, NM)

2010-12-28T23:59:59.000Z

194

The periodicity of the eta Carinae events  

E-Print Network (OSTI)

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.

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

195

Surface topography measurements over the 1 meter to 10 micrometer spatial period bandwidth  

Science Conference Proceedings (OSTI)

A recently-developed long-trace surface profiling instrument (LTP) is now in operation in our laboratory measuring surface profiles on grazing incidence aspheres and also conventional optical surface. The LTP characterizes surface height profiles in a non-contact manner over spatial periods ranging from 1 meter (the maximum scan length) to 2 mm (the Nyquist period for 1 mm sampling period) and complements the range of our WYKO NCP-1000 2.5X surface roughness profiler (5 mm to 9.8 {mu}m). Using these two instruments, we can fully characterize both figure and finish of an optical surface in the same way that we normally characterize surface finish, e.g., by means of the power spectral density function in the spatial frequency domain. A great deal of information about the distribution of figure errors over various spatial frequency ranges is available from this data, which is useful for process control and predicting performance at the desired wavelength and incidence angle. In addition, the LTP is able to measure the absolute radius of curvature on long-radius optics with high precision and accuracy. Angular errors in the optical head are measured in real time by an electronic autocollimator as the head traverses the linear air bearing slide. Measurements of kilometer radius optics can be made very quickly and the data analyzed in a format that is very easy to understand. 17 refs., 10 figs.

Takacs, P.Z.; Furenlid, K.; DeBiasse, R.A.; Church, E.L. (Brookhaven National Lab., Upton, NY (USA); Army Research and Development Command, Dover, NJ (USA))

1989-09-01T23:59:59.000Z

196

Shock Dynamics in Layered Periodic Media  

E-Print Network (OSTI)

Solutions of constant-coefficient nonlinear hyperbolic PDEs generically develop shocks, even if the initial data is smooth. Solutions of hyperbolic PDEs with variable coefficients can behave very differently. We investigate formation and stability of shock waves in a one-dimensional periodic layered medium by computational study of time-reversibility and entropy evolution. We find that periodic layered media tend to inhibit shock formation. For small initial conditions and large impedance variation, no shock formation is detected even after times much greater than the time of shock formation in a homogeneous medium. Furthermore, weak shocks are observed to be dynamically unstable in the sense that they do not lead to significant long-term entropy decay. We propose a characteristic condition for admissibility of shocks in heterogeneous media that generalizes the classical Lax entropy condition and accurately predicts the formation or absence of shocks in these media.

David I Ketcheson; Randall J. LeVeque

2011-05-14T23:59:59.000Z

197

Coupling light to periodic nanostructures.  

E-Print Network (OSTI)

??This thesis describes coupling of light to periodic structures. A material is patterned with a regular pattern on a length scale comparable to the wavelength… (more)

Driessen, Eduard Frans Clemens

2009-01-01T23:59:59.000Z

198

On the Time Times Temperature Bound  

E-Print Network (OSTI)

Recently Hod proposes a lower bound on the relaxation time of a perturbed thermodynamic system. For gravitational systems this bound transforms into a condition on the fundamental quasinormal frequency. We test the bound in some spacetimes whose quasinormal frequencies are calculated exactly, as the three-dimensional BTZ black hole, the D-dimensional de Sitter spacetime, and the D-dimensional Nariai spacetime. We find that for some of these spacetimes their fundamental quasinormal frequencies do not satisfy the bound proposed by Hod.

A. Lopez-Ortega

2010-06-28T23:59:59.000Z

199

Periodic  

NLE Websites -- All DOE Office Websites (Extended Search)

04 04 by C.G. Wohl (LBNL). Adapted from the Commission of Atomic Weights and Isotopic Abundances, "Atomic Weights of the Elements 1995," Pure and Applied Chemistry 68, 2339 (1996), and G. Audi and A.H. Wapstra, "The 1993 Mass Evaluation," Nucl. Phys. A565, 1 (1993). The atomic number (top left) is the number of protons in the nucleus. The atomic mass (bottom) is weighted by isotopic abundances in the Earth's surface. For a new determination of atomic masses, not weighted by abundances, see G. Audi, A.H. Wapstra, and C. Thibault, Nucl. Phys. A729, 337 (2003). Atomic masses are relative to the mass of the carbon-12 isotope, defined to be exactly 12 unified atomic mass units (u). Errors range from 1 to 9 in the last digit quoted. Relative isotopic abundances often vary considerably, both in natural and commercial samples. A number in parentheses is the mass of the longest-lived

200

Observed Interaction between Low and High Frequency Motions off the Coasts of Peru and California  

Science Conference Proceedings (OSTI)

Datasets taken near the coasts of Peru and California have been analyzed to explore the evidence of a correlation between the high frequency (period 4 day) motions. A large part of the high frequency ...

Pijusi K. Kundu; Robert C. Beardsley; Adriana Huyer

1990-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Embedding a chaotic signature in a periodic train: can periodic signals be chaotic?  

E-Print Network (OSTI)

We show how a chaotic system can be locked to emit a periodic waveform belonging to its chaotic attractor. We numerically demonstrate our idea in a system composed of a semiconductor laser driven to chaos by optical feedback from a short external cavity. The clue is the injection of an appropriate periodic signal that modulates the phase and amplitude of the intra-cavity radiation, a chaotic analogy of conventional mode-locking. The result is a time process that manifests a chaotic signature embedded in a long-scale periodic train.

Antonio Mecozzi; Cristian Antonelli

2008-11-03T23:59:59.000Z

202

Discontinuous bifurcations of periodic solutions  

Science Conference Proceedings (OSTI)

This paper discusses different aspects of bifurcations of periodic solutions in discontinuous systems. It is explained how jumps in the fundamental solution matrix lead to jumps of the Floquet multipliers of periodic solutions. A Floquet multiplier of ... Keywords: Bifurcation, Discontinuous, Dry friction, Stick-slip

R. I. Leine; D. H. Van Campen

2002-08-01T23:59:59.000Z

203

Graphene Frequency Multipliers  

E-Print Network (OSTI)

In this letter, the ambipolar transport properties of graphene flakes have been used to fabricate full-wave signal rectifiers and frequency-doubling devices. By correctly biasing an ambipolar graphene field-effect transistor ...

Wang, Han

204

The frequency dependent impedance of an HVdc converter  

Science Conference Proceedings (OSTI)

A linear and direct method of determining the frequency dependent impedance of a 12 pulse HVdc converter is presented. Terms are developed for both the dc and ac side impedances of the converter, including the effect of the firing angle control system, the commutation period, and the variability of the commutation period. The impedance predictions are verified by dynamic simulation.

Wood, A.R.; Arrillaga, J. [Univ. of Canterbury, Christchurch (New Zealand)

1995-07-01T23:59:59.000Z

205

Why inverse document frequency?  

Science Conference Proceedings (OSTI)

Inverse Document Frequency (IDF) is a popular measure of a word's importance. The IDF invariably appears in a host of heuristic measures used in information retrieval. However, so far the IDF has itself been a heuristic. In this paper, we show IDF to ...

Kishore Papineni

2001-06-01T23:59:59.000Z

206

Performance Period Total Fee Paid  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Period Period Total Fee Paid 4/29/2012 - 9/30/2012 $418,348 10/1/2012 - 9/30/2013 $0 10/1/2013 - 9/30/2014 $0 10/1/2014 - 9/30/2015 $0 10/1/2015 - 9/30/2016 $0 Cumulative Fee Paid $418,348 Contract Type: Cost Plus Award Fee Contract Period: $116,769,139 November 2011 - September 2016 $475,395 $0 Fee Information Total Estimated Contract Cost $1,141,623 $1,140,948 $1,140,948 $5,039,862 $1,140,948 Maximum Fee $5,039,862 Minimum Fee Fee Available Portage, Inc. DE-DT0002936 EM Contractor Fee Site: MOAB Uranium Mill Tailings - MOAB, UT Contract Name: MOAB Uranium Mill Tailings Remedial Action Contract September 2013 Contractor: Contract Number:

207

Total Resonant Transmission and Reflection by Periodic Structures  

E-Print Network (OSTI)

Resonant scattering of plane waves by a periodic slab under conditions close to those that support a guided mode is accompanied by sharp transmission anomalies. For two-dimensional structures, we establish sufficient conditions, involving structural symmetry, under which these anomalies are characterized by total transmission and total reflection at frequencies separated by an arbitrarily small amount. The loci of total reflection and total transmission are real-analytic curves in frequency-wavenumber space that intersect quadratically at a single point corresponding to the guided mode. A single anomaly or multiple anomalies can be excited by the interaction with a single guided mode.

Stephen P. Shipman; Hairui Tu

2011-05-14T23:59:59.000Z

208

Dogs and Time  

NLE Websites -- All DOE Office Websites (Extended Search)

Question: I travel often and worry how leaving for long periods of time (and boarding my dog) will affect her. I wouldn't think that dogs could understand the concept of...

209

THE INDUCTION PERIOD IN PHOTOSYNTHESIS  

E-Print Network (OSTI)

When a plant is illuminated, its rate of photosynthesis is at first low and gradually increases until it becomes constant. This induction period was first observed by Osterhout and Haas (1918) for UIva and independently confirmed by Warburg (1920) with Chlorella. It has

L. Smith

1937-01-01T23:59:59.000Z

210

Stability of Underwater Periodic Locomotion  

E-Print Network (OSTI)

Most aquatic vertebrates swim by lateral flapping of their bodies and caudal fins. While much effort has been devoted to understanding the flapping kinematics and its influence on the swimming efficiency, little is known about the stability (or lack of) of periodic swimming. It is believed that stability limits maneuverability and body designs/flapping motions that are adapted for stable swimming are not suitable for high maneuverability and vice versa. In this paper, we consider a simplified model of a planar elliptic body undergoing prescribed periodic heaving and pitching in potential flow. We show that periodic locomotion can be achieved due to the resulting hydrodynamic forces, and its value depends on several parameters including the aspect ratio of the body, the amplitudes and phases of the prescribed flapping. We obtain closed-form solutions for the locomotion and efficiency for small flapping amplitudes, and numerical results for finite flapping amplitudes. We then study the stability of the (finite amplitude flapping) periodic locomotion using Floquet theory. We find that stability depends nonlinearly on all parameters. Interesting trends of switching between stable and unstable motions emerge and evolve as we continuously vary the parameter values. This suggests that, for live organisms that control their flapping motion, maneuverability and stability need not be thought of as disjoint properties, rather the organism may manipulate its motion in favor of one or the other depending on the task at hand.

Fangxu Jing; Eva Kanso

2013-04-18T23:59:59.000Z

211

All-sky Search for Periodic Gravitational Waves in the Full S5 LIGO Data  

E-Print Network (OSTI)

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 wher...

Abadie, J; Abbott, R; Abbott, T D; Abernathy, M; Accadia, T; Acernese, F; Adams, C; Adhikari, R; Affeldt, C; Ajith, P; Allen, B; Allen, G S; Ceron, E Amador; Amariutei, D; Amin, R S; Anderson, S B; Anderson, W G; Arai, K; Arain, M A; Araya, M C; Aston, S M; Astone, P; Atkinson, D; Aufmuth, P; Aulbert, C; Aylott, B E; Babak, S; Baker, P; Ballardin, G; Ballmer, S; Barker, D; Barone, F; Barr, B; Barriga, P; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Bastarrika, M; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Behnke, B; Beker, M G; Bell, A S; Belletoile, A; Belopolski, I; Benacquista, M; Berliner, J M; Bertolini, A; Betzwieser, J; Beveridge, N; Beyersdorf, P 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; 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; Brummit, A; Bulik, T; Bulten, H J; Buonanno, A; Burguet--Castell, J; Burmeister, O; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cain, J; Calloni, E; Camp, J B; Campsie, P; Cannizzo, J; Cannon, K; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Caride, S; Caudill, S; Cavagliŕ, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chaibi, O; Chalermsongsak, T; Chalkley, E; Charlton, P; Chassande-Mottin, E; Chelkowski, S; Chen, Y; Chincarini, A; Chiummo, A; Cho, H; Christensen, N; Chua, S S Y; Chung, C T Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J; Clayton, J H; Cleva, F; Coccia, E; Cohadon, P -F; Colacino, C N; Colas, J; 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; Coyne, D C; Creighton, J D E; Creighton, T D; Cruise, A M; Cumming, A; Cunningham, L; Cuoco, E; Cutler, R M; Dahl, K; Danilishin, S L; Dannenberg, R; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Davies, G; Daw, E J; Day, R; Dayanga, T; De Rosa, R; DeBra, D; Debreczeni, G; Degallaix, J; Del Pozzo, W; del Prete, M; Dent, T; Dergachev, V; DeRosa, R; DeSalvo, R; Dhurandhar, S; Di Fiore, L; Di Lieto, A; Di Palma, I; Emilio, M Di Paolo; Di Virgilio, A; Díaz, M; Dietz, A; Donovan, F; Dooley, K L; 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; Fan, Y; Farr, B F; Farr, W; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Flanigan, M; Foley, S; Forsi, E; Forte, L A; Fotopoulos, N; Fournier, J -D; Franc, J; Frasca, S; Frasconi, F; Frede, M; Frei, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Friedrich, D; Fritschel, P; Frolov, V V; Fulda, P J; Fyffe, M; Galimberti, M; Gammaitoni, L; Ganija, M R; Garcia, J; Garofoli, J A; Garufi, F; Gáspár, M E; Gemme, G; Geng, R; Genin, E; Gennai, A; Gergely, L Á; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gill, C; Goetz, E; Goggin, L M; González, G; Gorodetsky, M L; Goßler, S; Gouaty, R; Graef, C; Granata, M; Grant, A; Gras, S; Gray, C; Gray, N; Greenhalgh, R J S; Gretarsson, A M; Greverie, C; Grosso, R; Grote, H; Grunewald, S; Guidi, G M; Guido, C; Gupta, R; Gustafson, E K; Gustafson, R; Ha, T; Hage, B; 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; Hayler, T; Heefner, J; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hendry, M A; Heng, I S; Heptonstall, A W; Herrera, V; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Hong, T; Hooper, S; Hosken, D J; 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; Jang, H; Jaranowski, P; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, P; Kalogera, V; Kamaretsos, I; Kandhasamy, S; Kang, G; Kanner, J B; Katsavounidis, E; Katzman, W; Kaufer, H; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Keresztes, Z; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B; Kim, C; Kim, D; Kim, H; Kim, K; Kim, N; Kim, Y -M; King, P J; Kinsey, M; Kinzel, D L; Kissel, J S; Klimenko, S; Kokeyama, K; Kondrashov, V; Kopparapu, R; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D; Kringel, V; Krishnamurthy, S; Krishnan, B; Królak, A; Kuehn, G; Kumar, R; Kwee, P; Lam, P K; Landry, M; Lang, M; Lantz, B; Lastzka, N; Lawrie, C; Lazzarini, A; Leaci, P; Lee, C H; Lee, H M

2011-01-01T23:59:59.000Z

212

High frequency reference electrode  

DOE Patents (OSTI)

A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo'' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.

Kronberg, J.W.

1991-03-05T23:59:59.000Z

213

High frequency reference electrode  

DOE Patents (OSTI)

A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or halo' at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes. 4 figs.

Kronberg, J.W.

1994-05-31T23:59:59.000Z

214

High frequency reference electrode  

DOE Patents (OSTI)

A high frequency reference electrode for electrochemical experiments comprises a mercury-calomel or silver-silver chloride reference electrode with a layer of platinum around it and a layer of a chemically and electrically resistant material such as TEFLON around the platinum covering all but a small ring or "halo" at the tip of the reference electrode, adjacent to the active portion of the reference electrode. The voltage output of the platinum layer, which serves as a redox electrode, and that of the reference electrode are coupled by a capacitor or a set of capacitors and the coupled output transmitted to a standard laboratory potentiostat. The platinum may be applied by thermal decomposition to the surface of the reference electrode. The electrode provides superior high-frequency response over conventional electrodes.

Kronberg, James W. (Aiken, SC)

1994-01-01T23:59:59.000Z

215

Einstein@Home all-sky search for periodic gravitational waves in LIGO S5 data  

E-Print Network (OSTI)

This paper presents results of an all-sky search for periodic gravitational waves in the frequency range [50,1?190]??Hz and with frequency derivative range of ?[-20,1.1]×10[superscript -10]??Hz?s[superscript -1] for the ...

Barsotti, Lisa

216

Maslov indices for periodic orbits  

E-Print Network (OSTI)

It is shown that there is a generalization of the Conley-Zehnder index for periodic trajectories of a classical Hamiltonian system $(Q, \\omega, H)$ from the case $Q = T^*R^n$ to arbitrary symplectic manifolds. As it turns out, it is precisely this index which appears as a Maslov phase in the trace formulas by Gutzwiller and Duistermaat-Guillemin. Contribution presented at the XIX ICGTMP Salamanca June 92.

Meinrenken, E

1992-01-01T23:59:59.000Z

217

THE DOUBLE PULSAR ECLIPSES. I. PHENOMENOLOGY AND MULTI-FREQUENCY ANALYSIS  

Science Conference Proceedings (OSTI)

The double pulsar PSR J0737-3039A/B displays short, 30 s eclipses that arise around conjunction when the radio waves emitted by pulsar A are absorbed as they propagate through the magnetosphere of its companion pulsar B. These eclipses offer a unique opportunity to directly probe the magnetospheric structure and the plasma properties of pulsar B. We have performed a comprehensive analysis of the eclipse phenomenology using multi-frequency radio observations obtained with the Green Bank Telescope. We have characterized the periodic flux modulations previously discovered at 820 MHz by McLaughlin et al. and investigated the radio frequency dependence of the duration and depth of the eclipses. Based on their weak radio frequency evolution, we conclude that the plasma in pulsar B's magnetosphere requires a large multiplicity factor ({approx}10{sup 5}). We also found that, as expected, flux modulations are present at all radio frequencies in which eclipses can be detected. Their complex behavior is consistent with the confinement of the absorbing plasma in the dipolar magnetic field of pulsar B as suggested by Lyutikov and Thompson and such a geometric connection explains that the observed periodicity is harmonically related to pulsar B's spin frequency. We observe that the eclipses require a sharp transition region beyond which the plasma density drops off abruptly. Such a region defines a plasmasphere that would be well inside the magnetospheric boundary of an undisturbed pulsar. It is also two times smaller than the expected standoff radius calculated using the balance of the wind pressure from pulsar A and the nominally estimated magnetic pressure of pulsar B.

Breton, R. P. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Kaspi, V. M. [Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada); McLaughlin, M. A. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Lyutikov, M. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Kramer, M. [Max Planck Institut fuer Radioastronomie, Auf dem Huegel 69, 53121 Bonn (Germany); Stairs, I. H. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Ransom, S. M. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Ferdman, R. D. [University of Manchester, Jodrell Bank Centre for Astrophysics, Alan Turing Building, Manchester, M13 9PL (United Kingdom); Camilo, F. [Columbia University, New York, NY 10027 (United States); Possenti, A., E-mail: breton@astro.utoronto.ca [INAF-Osservatorio Astronomico di Cagliari, Poggio dei Pini, strada 54, I-09012 Capoterra (Italy)

2012-03-10T23:59:59.000Z

218

Periodicities In The X-Ray Intensity Variations of TV Columbae: An Intermediate Polar  

E-Print Network (OSTI)

We present results from a temporal analysis of the longest and the most sensitive X-ray observations of TV Columbae--an intermediate polar. The observations were carried out with the RXTE PCA, ROSAT PSPC, and ASCA. Data were analyzed using a 1-dimensional CLEAN and Bayesian algorithms. The presence of a nearly sinusoidal modulation due to the spin of the white dwarf is seen clearly in all the data, confirming the previous reports based on the EXOSAT data. An improved period of 1909.7+/-2.5s is derived for the spin from the RXTE data.The binary period of 5.5hr is detected unambiguously in X-rays for the first time. Several side-bands due to the interaction of these periods are observed in the power spectra, thereby suggesting contributions from both the disk-fed and the stream-fed accretion for TV Col. The accretion disk could perhaps be precessing as side-bands due to the influence of 4 day period on the orbital period are seen. The presence of a significant power at certain side-bands of the spin frequency indicates that the emission poles are asymmetrically located. The strong power at the orbital side-bands seen in both the RXTE and ROSAT data gives an indication for an absorption site fixed in the orbital frame. Both the spin and the binary modulation are found to be energy-dependent. Increased hardness ratio during a broad dip in the intensity at binary phase of 0.75--1.0 confirms the presence of a strong attenuation due to additional absorbers probably from an impact site of the accretion stream with the disk or magnetosphere. Hardness ratio variations and the energy dependent modulation depth during the spin modulation can be explained by partially covered absorbers in the path of X-ray emission region in the accretion stream.

V. R. Rana; K. P. Singh; E. M. Schlegel; P. Barrett

2003-11-23T23:59:59.000Z

219

Einstein@Home all-sky search for periodic gravitational waves in LIGO S5 data  

E-Print Network (OSTI)

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...

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

220

Laser-frequency multiplication  

SciTech Connect

A high quality mode locked pulse train was obtained at 9.55 micrometers, the CO2 wavelength chosen for frequency doubling into the atmospheric window at 4.8 micrometers. The pulse train consists of a 3 micro sec burst of 1.5 nsec pulses separated by 40 nsec, in a TEM(00) mode and with a total energy of 100 mJ. The pulse intensity without focussing is about 3 MW/sq.cm., already quite close to the target intensity of 10 MW/sq.cm. for frequency doubling in a AgGaSe2 crystal. The mode-locked train is obtained by intracavity modulation at 12.5 MHz using a germanium crystal driven with a power of about 30 Watts. Line selection is achieved firstly by the use of a 0.92 mm thick CaF2 plate at the Brewster angle within the cavity, which completely suppresses 10.6 micrometer band radiation. Secondly, a particular rotational line, the P20 at 9.55 micrometers, is selected by the injection of a continuous beam is mode-matched to the pulsed laser cavity using a long focal length lens, and for best line-locking it is necessary to fine tune the length of the pulsed laser resonator. Injection causes substantial depression of the gain switched spike.

Not Available

1991-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Time and Frequency from A to Z: Ch to Cy  

Science Conference Proceedings (OSTI)

... d rb ). Common-view measurements were made for many years using land based transmitters as the reference. Today, nearly ...

2010-10-05T23:59:59.000Z

222

NIST Time and Frequency Div. - 2002: Strategic Focus 2  

Science Conference Proceedings (OSTI)

... for delivery of a few bytes of transmission serves as ... that there has been a tremendous expansion in the ... made as part of a long-term plan to assure ...

223

Time and Frequency Div. 1995/1996 - Technical Highlights  

Science Conference Proceedings (OSTI)

... James Murray of the University of Arizona have developed ... for third and higher-order mixing products ... a V-type configuration of energy levels, atomic ...

224

Time and Frequency from A to Z: D to Do  

Science Conference Proceedings (OSTI)

... The new changes were enacted by the The Energy Policy Act of 2005, which extended the length of DST by about one month in the interest of ...

2010-10-05T23:59:59.000Z

225

NIST Time and Frequency Div. - 2004: Strategic Focus 2  

Science Conference Proceedings (OSTI)

... updates the servers, software, and network infrastructure, working with ... to ensure automatic recovery from power failures or loss of primary ...

226

Time and Frequency from A to Z: C to Ce  

Science Conference Proceedings (OSTI)

... Only those atoms that changed their energy state while ... the movement of the atoms and cool them to ... by the combination of laser cooling and the ...

2010-10-05T23:59:59.000Z

227

Parametric time?frequency estimation of prosthetic heart valve sounds  

Science Conference Proceedings (OSTI)

Prosthetic heart valves have been responsible for extending the life spans and improving the quality of life of many people with serious heart conditions. Even though the heart valves are extremely reliable

D. E. Perkins; G. H. Thomas; G. A. Clark

1998-01-01T23:59:59.000Z

228

Time and Frequency from A to Z: L  

Science Conference Proceedings (OSTI)

... However, in accordance with the Department of Homeland Security (DHS) Appropriations Act, the US Coast Guard terminated the transmission of ...

2010-10-05T23:59:59.000Z

229

NIST Time and Frequency Division Seminars and Workshops  

Science Conference Proceedings (OSTI)

... This makes WSTS your primary source for information about the effects of evolving synchronization systems on network operators and equipment ...

2013-09-19T23:59:59.000Z

230

AFGa: Time and frequency transfer (ATF2010 joint session)  

E-Print Network (OSTI)

of Astronomy and Astrophysics, China (SRS), 2 Karoo Array Telescope, South Africa, 3 Brigham Young University

Choi, Woo-Young

231

NIST Time and Frequency Div. - 2002: Strategic Focus 3  

Science Conference Proceedings (OSTI)

... area, stimulated in large part by some of our fundamental research, is a (Defense Advanced Research Project Agency) DARPA-funded program to ...

232

NIST Time and Frequency Radio Stations: WWV, WWVH, and ...  

Science Conference Proceedings (OSTI)

... that would later also become the home of WWV. ... They include heating coils and run year round. ... company provides power through an oil-filled, 500 ...

2012-10-30T23:59:59.000Z

233

Time and Frequency from A to Z: H  

Science Conference Proceedings (OSTI)

... hertz. Therefore, the Q is about 10 9 , or at least one order of magnitude better than that of a commercial cesium standard. ...

2010-10-05T23:59:59.000Z

234

Time-frequency methods for detecting spike activity of stomach  

Science Conference Proceedings (OSTI)

H.H. Sun. School of Biomedical Engineering, Science and Health Systems, Drexel University, ... Correspondence should be addressed to Professor Hun H. Sun;.

235

Improved analysis of musical sounds using time-frequency distributions.  

E-Print Network (OSTI)

??The objective of this research is to improve the analysis of musical sounds in comparison to traditional additive analysis, i.e. Fourier Analysis. Namely, the focus… (more)

Kosek, Paul C.

2005-01-01T23:59:59.000Z

236

NIST Time and Frequency Transfer using the Two Way ...  

Science Conference Proceedings (OSTI)

... to the 1 ns level, but this requires a portable earth station ... For questions or more information contact Marc Weiss at mweiss@boulder.nist.gov. Home.

237

Time and Frequency from A to Z: I  

Science Conference Proceedings (OSTI)

... The line on the Earth, generally located at 180° longitude, that separates two consecutive calendar ... For more information, visit the ITS home page. ...

2010-10-05T23:59:59.000Z

238

Time and Frequency from A to Z: F  

Science Conference Proceedings (OSTI)

... The total power (or voltage) measured by a spectrum analyzer depends on ... An electronic instrument or circuit that accepts two input signals at two ...

2010-10-05T23:59:59.000Z

239

NIST Time and Frequency Services: Results of 2001 ...  

Science Conference Proceedings (OSTI)

... S1-0098, I do use it for solar weather info. S1-0099, I use the geo alerts! ... S1-0284, solar flux data and weather are important to me. ...

240

NIST Time and Frequency Services: Results of 2001 ...  

Science Conference Proceedings (OSTI)

... S1-0838, I use the service for North American propagation ionospheric weather and GPS info. S1-0839, I get solar conditons on the internet. ...

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

NIST Time and Frequency Radio Stations: WWV, WWVH, and ...  

Science Conference Proceedings (OSTI)

... year, depending on weather conditions and irrigation ... The air conditioning units currently in operation ... kVA, Y-connected three-phase transformer. ...

2011-11-16T23:59:59.000Z

242

Animation of JILA Frequency Comb Spectroscopy Technique  

Science Conference Proceedings (OSTI)

Animation of JILA Frequency Comb Spectroscopy Technique. The new JILA "frequency comb spectroscopy" technique ...

2012-08-17T23:59:59.000Z

243

Computer simulation of low-frequency electromagnetic data acquisition  

DOE Green Energy (OSTI)

Computer simulation of low frequency electromagnetic (LFEM) digital data acquisition in the presence of natural field noise demonstrates several important limitations and considerations. Without the use of a remote reference noise removal scheme it is difficult to obtain an adequate ratio of signal to noise below 0.1 Hz for frequency domain processing and below 0.3 Hz base frequency for time domain processing for a typical source-receiver configuration. A digital high-pass filter substantially facilitates rejection of natural field noise above these frequencies but, at lower frequencies where much longer stacking times are required, it becomes ineffective. Use of a remote reference to subtract natural field noise extends these low-frequency limits a decade, but this technique is limited by the resolution and dynamic range of the instrumentation. Gathering data in short segments so that natural field drift can be offset for each segment allows a higher gain setting to minimize dynamic range problems.

SanFilipo, W.A.; Hohmann, G.W.

1982-02-01T23:59:59.000Z

244

Radio frequency coaxial feedthrough  

DOE Patents (OSTI)

An improved radio frequency coaxial transmission line vacuum feed-through provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflections from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits voltage and power handling capabilities of a feedthrough.

Owens, Thomas L. (Kingston, TN)

1989-01-17T23:59:59.000Z

245

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X{sub 2} Y(NO{sub 3}){sub 5} {center_dot} 2 nZ{sub 2}O wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

246

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmonic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X{sub 2} Y(NO{sub 3}){sub 5} {center dot} 2 nZ{sub 2}O wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, C.A.; Davis, L.E.; Webb, M.

1990-10-16T23:59:59.000Z

247

Frequency mixing crystal  

DOE Patents (OSTI)

In a laser system for converting infrared laser light waves to visible light comprising a source of infrared laser light waves and means of harmoic generation associated therewith for production of light waves at integral multiples of the frequency of the original wave, the improvement of said means of harmonic generation comprising a crystal having the chemical formula X.sub.2 Y(NO.sub.3).sub.5 .multidot.2 nZ.sub.2 o wherein X is selected from the group consisting of Li, Na, K, Rb, Cs, and Tl; Y is selected from the group consisting of Sc, Y, La, Ce, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In; Z is selected from the group consisting of H and D; and n ranges from 0 to 4.

Ebbers, Christopher A. (Livermore, CA); Davis, Laura E. (Manteca, CA); Webb, Mark (Salida, CA)

1992-01-01T23:59:59.000Z

248

Impact of Atmospheric Intraseasonal Variability in the Indian Ocean: Low-Frequency Rectification in Equatorial Surface Current and Transport  

Science Conference Proceedings (OSTI)

An ocean general circulation model (OGCM) is used to investigate the low-frequency (period longer than 90 days) rectification of atmospheric intraseasonal variability (10–90-day periods) in zonal surface current and transport of the equatorial ...

Weiqing Han; Peter Webster; Roger Lukas; Peter Hacker; Aixue Hu

2004-06-01T23:59:59.000Z

249

Time Trends in Dutch Children's Mental Health.  

E-Print Network (OSTI)

??This study investigated time trends in Dutch children's and adolescent's mental health problems by comparing population samples from different time periods. From 1983 to 2003,… (more)

Tick, N.T.

2007-01-01T23:59:59.000Z

250

Computing with almost periodic functions  

E-Print Network (OSTI)

The paper develops a method for discrete computational Fourier analysis of functions defined on quasicrystals and other almost periodic sets. A key point is to build the analysis around the emerging theory of quasicrystals and diffraction in the setting on local hulls and dynamical systems. Numerically computed approximations arising in this way are built out of the Fourier module of the quasicrystal in question, and approximate their target functions uniformly on the entire infinite space. The methods are entirely group theoretical, being based on finite groups and their duals, and they are practical and computable. Examples of functions based on the standard Fibonacci quasicrystal serve to illustrate the method (which is applicable to all quasicrystals modeled on the cut and project formalism).

R. V. Moody; M. Nesterenko; J. Patera

2008-08-13T23:59:59.000Z

251

TERRESTRIAL, HABITABLE-ZONE EXOPLANET FREQUENCY FROM KEPLER  

Science Conference Proceedings (OSTI)

Data from Kepler's first 136 days of operation are analyzed to determine the distribution of exoplanets with respect to radius, period, and host-star spectral type. The analysis is extrapolated to estimate the percentage of terrestrial, habitable-zone (HZ) exoplanets. The Kepler census is assumed to be complete for bright stars (magnitude 0.5 Earth radius and periods <42 days. It is also assumed that the size distribution of planets is independent of orbital period and that there are no hidden biases in the data. Six significant statistical results are found: there is a paucity of small planet detections around faint target stars, probably an instrumental effect; the frequency of mid-size planet detections is independent of whether the host star is bright or faint; there are significantly fewer planets detected with periods <3 days, compared to longer periods, almost certainly an astrophysical effect; the frequency of all planets in the population with periods <42 days is 29%, broken down as terrestrials 9%, ice giants 18%, and gas giants 3%; the population has a planet frequency with respect to period which follows a power-law relation dN/dP {approx} P{sup {beta}-1}, with {beta} {approx_equal} 0.71 {+-} 0.08; and an extrapolation to longer periods gives the frequency of terrestrial planets in the HZs of FGK stars as {eta}{sub Circled-Plus} {approx_equal} (34 {+-} 14)%. Thus about one-third of FGK stars are predicted to have at least one terrestrial, HZ planet.

Traub, Wesley A., E-mail: wtraub@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2012-01-20T23:59:59.000Z

252

Short-period global atmospheric waves revealed by nightglow observations  

Science Conference Proceedings (OSTI)

The night-time emissions of OH (6-2) and the O2 Atmospheric System (0-1) have been observed at Maimaga (63.1° N, 129.6° E) during the winters of 2007-2008 and 2008-2009 and revealed steady-frequency atmospheric oscillations near the mesopause ...

Natalia Karpova; Gustav Shved; Svetlana Ermolenko; Petr Ammosov; Galina Gavrilyeva; Elena Savenkova

2011-06-01T23:59:59.000Z

253

Towards a secure Frequency Monitoring NETwork (FNET) system  

Science Conference Proceedings (OSTI)

Reactive and real-time wide area monitoring systems (WAMS), such as the Frequency Monitoring NETwork (FNET) developed at Virginia Tech, allow for the gathering of frequency data throughout the entire power grid. FNET uses the Internet as a communication ... Keywords: FNET, Smart Grid, cyber security

Joseph L. McDaniel; Ambareen Siraj

2010-04-01T23:59:59.000Z

254

Optical frequency combs: From frequency metrology to optical ...  

Science Conference Proceedings (OSTI)

... and to dis- tribute the load of the ... measurements of frequency ratios (ie, energy ratios), and ... accuracy or stability versus power consumption, cost, or ...

2004-01-27T23:59:59.000Z

255

Time lines  

Science Conference Proceedings (OSTI)

... The reactor was shut down on April 3, 2011 and restarted to low power on February 8, 2012. During the post-outage period, which runs until ...

256

Reactor control rod timing system  

DOE Patents (OSTI)

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.

Wu, Peter T. K. (Clifton Park, NY)

1982-01-01T23:59:59.000Z

257

High-Frequency Skywave Radar Track of Tropical Storm Debra  

Science Conference Proceedings (OSTI)

Tropical Storm Debra was tracked over a 31 h period in the Gulf of Mexico using the Wide Aperture Research Facility (WARF) high-frequency (HF) skywave radar in California. In contrast to the first WARF skywave radar tracking experiment in which ...

Joseph W. Maresca Jr.; Christopher T. Carlson

1981-04-01T23:59:59.000Z

258

Laser frequency combs for astronomical observations  

E-Print Network (OSTI)

A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require measurements of Doppler velocity drifts of about 1 centimeter per second per year, and astronomical spectrographs have not yet been calibrated to this tolerance. We demonstrate the first use of a laser frequency comb for wavelength calibration of an astronomical telescope. Even with a simple analysis, absolute calibration is achieved with an equivalent Doppler precision of approximately 9 meters per second at about 1.5 micrometers - beyond state-of-the-art accuracy. We show that tracking complex, time-varying systematic effects in the spectrograph and detector system is a particular advantage of laser frequency comb calibration. This technique promises an effective means for modeling and removal of such systematic effects to the accuracy required by future experiments to see direct evidence of the universe's putative acceleration.

Tilo Steinmetz; Tobias Wilken; Constanza Araujo-Hauck; Ronald Holzwarth; Theodor W. Hänsch; Luca Pasquini; Antonio Manescau; Sandro D'Odorico; Michael T. Murphy; Thomas Kentischer; Wolfgang Schmidt; Thomas Udem

2008-09-09T23:59:59.000Z

259

Effective switching frequency multiplier inverter  

SciTech Connect

A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

Su, Gui-Jia (Oak Ridge, TN); Peng, Fang Z. (Okemos, MI)

2007-08-07T23:59:59.000Z

260

Keck II spectroscopy of mHz quasi-periodic oscillations in Hercules X-1  

E-Print Network (OSTI)

We present Keck II spectroscopy of an optical mHz quasi-periodic oscillations (QPOs) in the lightcurve of the X-ray pulsar binary Her X-1. In the power spectrum it appears as `peaked noise', with a coherency $\\sim$2, a central frequency of 35 mHz and a peak-to-peak amplitude of 5%. However, the dynamic power spectrum shows it to be an intermittent QPO, with a lifetime of $\\sim$hundred seconds, as expected if the lifetime of the orbiting material is equal to the thermal timescale of the inner disk. We have decomposed the spectral time series into constant and variable components and used blackbody fits to the resulting spectra to characterise the spectrum of the QPO variability and constrain possible production sites. We find that the spectrum of the QPO is best-fit by a small hot region, possibly the inner regions of the accretion disk, where the ballistic accretion stream impacts onto the disk. The lack of any excess power around the QPO frequency in the X-ray power spectrum, created using simultaneous lightcurves from XTE, implies that the QPO is not simply reprocessed X-ray variability.

K O'Brien; Keith Horne; B Boroson; M Still; R Gomer; JB Oke; P Boyd; S Vrtilek

2001-05-10T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

The Einstein@Home search for periodic gravitational waves in LIGO S4 data  

E-Print Network (OSTI)

A search for periodic gravitational waves, from sources such as isolated rapidly-spinning neutron stars, was carried out using 510 hours of data from the fourth LIGO science run (S4). The search was for quasi-monochromatic waves in the frequency range from 50 Hz to 1500 Hz, with a linear frequency drift f-dot (measured at the solar system barycenter) in the range -f/tau < f-dot < 0.1 f/tau, where the minimum spin-down age tau was 1000 years for signals below 300 Hz and 10000 years above 300 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, despite the large parameter space searched. No statistically significant signals were found. The sensitivity of the search is estimated, along with the fraction of parameter space that was vetoed because of contamination by instrumental artifacts. In the 100 Hz to 200 Hz band, more tha...

Abbott, B; Adhikari, R; Ajith, P; Allen, B; Allen, G; Amin, R; Anderson, D P; Anderson, S B; Anderson, W G; Arain, M A; Araya, M; Armandula, H; Armor, P; Aso, Y; Aston, S; Aufmuth, P; Aulbert, C; Babak, S; Ballmer, S; Bantilan, H; Barish, B C; Barker, C; Barker, D; Barr, B; Barriga, P; Barton, M A; Bastarrika, M; Bayer, K; Betzwieser, J; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Biswas, R; Black, E; Blackburn, K; Blackburn, L; Blair, D; Bland, B; Bodiya, T P; Bogue, L; Bork, R; Boschi, V; Bose, S; Brady, P R; Braginsky, V B; Brau, J E; Brinkmann, M; Brooks, A; Brown, D A; Brunet, G; Bullington, A; Buonanno, A; Burmeister, O; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cannizzo, J; Cannon, K; Cao, J; Cardenas, L; Casebolt, T; Castaldi, G; Cepeda, C; Chalkley, E; Charlton, P; Chatterji, S; Chelkowski, S; Chen, Y; Christensen, N; Clark, D; Clark, J; Cokelaer, T; Conte, R; Cook, D; Corbitt, T; Coyne, D; Creighton, J D E; Cumming, A; Cunningham, L; Cutler, R M; Dalrymple, J; Danzmann, K; Davies, G; De Bra, D; Degallaix, J; Degree, M; Dergachev, V; Desai, S; DeSalvo, R; Dhurandhar, S; Daz, M; Dickson, J; Dietz, A; Donovan, F; Dooley, K L; Doomes, E E; Drever, R W P; Duke, I; Dumas, J C; Dupuis, R J; Dwyer, J G; Echols, C; Eer, A; Ehrens, P; Ely, G; Espinoza, E; Etzel, T; Evans, T; Fairhurst, S; Fan, Y; Fazi, D; Fehrmann, H; Fejer, M M; Finn, L S; Flasch, K; Fotopoulos, N; Freise, A; Frey, R; Fricke, T; Fritschel, P; Frolov, V V; Fyffe, M; Garofoli, J; Gholami, I; Giaime, J A; Giampanis, S; Giardina, K D; Goda, K; Goetz, E; Goggin, L; González, G; Gossler, S; Gouaty, R; Grant, A; Gras, S; Gray, C; Gray, M; Greenhalgh, R J S; Gretarsson, A M; Grimaldi, F; Grosso, R; Grote, H; Grünewald, S; Günther, M; Gustafson, E K; Gustafson, R; Hage, B; Hallam, J M; Hammer, D; Hanna, C; Hanson, J; Harms, J; Harry, G; Harstad, E; Hayama, K; Hayler, T; Heefner, J; Heng, I S; Hennessy, M; Heptonstall, A; Hewitson, M; Hild, S; Hirose, E; Hoak, D; Hosken, D; Hough, J; Huttner, S H; Ingram, D; Ito, M; Ivanov, A; Johnson, B; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, Peter Ignaz Paul; Kalogera, V; Kamat, S; Kanner, J; Kasprzyk, D; Katsavounidis, E; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Khalili, F Ya; Khan, R; Khazanov, E; Kim, C; King, P; Kissel, J S; Klimenko, S; Kokeyama, K; Kondrashov, V; Kopparapu, R K; Kozak, D; Kozhevatov, I; Krishnan, B; Kwee, P; Lam, P K; Landry, M; Lang, M M; Lantz, B; Lazzarini, A; Lei, M; Leindecker, N; Leonhardt, V; Leonor, I; Libbrecht, K; Lin, H; Lindquist, P; Lockerbie, N A; Lodhia, D; Lormand, M; Lu, P; Lubinski, M; Lucianetti, A; Luck, H; Machenschalk, B; MacInnis, M; Mageswaran, M; Mailand, K; Mandic, V; Mrka, S; Mrka, Z; Markosyan, A; Markowitz, J; Maros, E; Martin, I; Martin, R M; Marx, J N; Mason, K; Matichard, F; Matone, L; Matzner, R; Mavalvala, N; McCarthy, R; McClelland, D E; McGuire, S C; McHugh, M; McIntyre, G; McIvor, G; McKechan, D; McKenzie, K; Meier, T; Melissinos, A; Mendell, G; Mercer, R A; Meshkov, S; Messenger, C J; Meyers, D; Miller, J; Minelli, J; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Miyakawa, O; Moe, B; Mohanty, S; Moreno, G; Mossavi, K; Mow Lowry, C; Müller, G; Mukherjee, S; Mukhopadhyay, H; Muller-Ebhardt, H; Munch, J; Murray, P; Myers, E; Myers, J; Nash, T; Nelson, J; Newton, G; Nishizawa, A; Numata, K; O'Dell, J; Ogin, G; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pan, Y; Pankow, C; Papa, M A; Parameshwaraiah, V; Patel, P; Pedraza, M; Penn, S; Perreca, A; Petrie, T; Pinto, I M; Pitkin, M; Pletsch, H J; Plissi, M V; Postiglione, F; Principe, M; Prix, R; Quetschke, V; Raab, F; Rabeling, D S; Radkins, H; Rainer, N; Rakhmanov, M; Ramsunder, M; Rehbein, H; Reid, S; Reitze, D H; Riesen, R; Riles, K; Rivera, B; Robertson, N A; Robinson, C; Robinson, E L; Roddy, S; Rodríguez, A; Rogan, A M; Rollins, J; Romano, J D; Romie, J; Route, R; Rowan, S; Rüdiger, A; Ruet, L; Russell, P; Ryan, K; Sakata, S; Samidi, M; Sanchodela Jordana, L; Sandberg, V; Sannibale, V; Saraf, S; Sarin, P; Sathyaprakash, B S; Sato, S; Saulson, P R; Savage, R; Savov, P; Schediwy, S W; Schilling, R; Schnabel, R; Schofield, R; Schutz, B F; Schwinberg, P; Scott, S M; Searle, A C; Sears, B; Seifert, F; Sellers, D; Sengupta, A S; Shawhan, P; Shoemaker, D H; Sibley, A; Siemens, X; Sigg, D; Sinha, S; Sintes, A M; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M R; Smith, N D; Somiya, K; Sorazu, B; Stein, L C; Stochino, A; Stone, R; Strain, K A; Strom, D M; Stuver, A; Summerscales, T Z; Sun, K X; Sung, M; Sutton, P J; Takahashi, H; Tanner, D B; Taylor, R; Taylor, R; Thacker, J; Thorne, K A; Thorne, K S; Thüring, A; Tokmakov, K V; Torres, C; Torrie, C; Traylor, G; Trias, M; Tyler, W; Ugolini, D; Ulmen, J; Urbanek, K; Vahlbruch, H; Van Den Broeck, C; vander Sluys, M; Vass, S; Vaulin, R; Vecchio, A; Veitch, J

2008-01-01T23:59:59.000Z

262

Radio Frequency Engineering, MDE, Accelerator Operations and...  

NLE Websites -- All DOE Office Websites (Extended Search)

Home Teams Low-Level Radio Frequency Magnet Power Supplies, Pulsed Power Radio Frequency, High Voltage Technologies Radio Frequency Operations CONTACTS Group Leader Dan Rees Deputy...

263

Frequency Control Performance Measurement and Requirements  

E-Print Network (OSTI)

power systems operations could significantly influence primary frequency control.power system operations could not significantly influence primary frequency control.power system operations. Determination of frequency control

Illian, Howard F.

2011-01-01T23:59:59.000Z

264

Infrastructure Failure - Types and Frequency  

U.S. Energy Information Administration (EIA)

Infrastructure Failure - Types and Frequency. Small events that have no impact on supplies Events that require supply/demand responses Events that result in a ...

265

Dynamic frequency allocation in fractional frequency reused OFDMA networks  

Science Conference Proceedings (OSTI)

This paper proposes a dynamic fractional frequency reused cell architecture that simplifies the problem of subcarrier allocation with frequency reuse in multicell OFDMA networks. The architecture divides the cell surface into two overlapping geographical ... Keywords: 3G, cellular networks, cross-layer adaptation, data networks, mobile communication systems, opportunistic scheduling, wireless communication

Syed Hussain Ali; Victor C. M. Leung

2009-08-01T23:59:59.000Z

266

Atomic Frequency standards Based on Pulsed Coherent Light Storage  

E-Print Network (OSTI)

We propose a new scheme of microwave frequency standards based on pulsed coherent optical information storage. Unlike the usual frequency reference where the Ramsey fringe is printed on the population of a certain state, we print the Ramsey fringe on the coherence. Then the coherence is detected in the form of a retrieval light. The central line of the Ramsey fringe can be used as a frequency reference in an absorption-cell-based atomic frequency standard. This scheme is free of light shifts as the interrogating process is separated from the optical pumping processes, and the cavity pulling effect is negligible due to the low Q requirement. Encoding the Ramsey interference into the retrieval light pulse has the merit of high signal to noise ratio and the estimated frequency stability of shot noise limit is about $2\\times10^{-14}$ in 1 second, this scheme is promising for building small, compact and stable atomic frequency standards.

Yan, Bo; Wang, Yuzhu

2008-01-01T23:59:59.000Z

267

TIME CALIBRATED OSCILLOSCOPE SWEEP  

DOE Patents (OSTI)

The time calibrator of an electric signal displayed on an oscilloscope is described. In contrast to the conventional technique of using time-calibrated divisions on the face of the oscilloscope, this invention provides means for directly superimposing equal time spaced markers upon a signal displayed upon an oscilloscope. More explicitly, the present invention includes generally a generator for developing a linear saw-tooth voltage and a circuit for combining a high-frequency sinusoidal voltage of a suitable amplitude and frequency with the saw-tooth voltage to produce a resultant sweep deflection voltage having a wave shape which is substantially linear with respect to time between equal time spaced incremental plateau regions occurring once each cycle of the sinusoidal voltage. The foregoing sweep voltage when applied to the horizontal deflection plates in combination with a signal to be observed applied to the vertical deflection plates of a cathode ray oscilloscope produces an image on the viewing screen which is essentially a display of the signal to be observed with respect to time. Intensified spots, or certain other conspicuous indications corresponding to the equal time spaced plateau regions of said sweep voltage, appear superimposed upon said displayed signal, which indications are therefore suitable for direct time calibration purposes.

Owren, H.M.; Johnson, B.M.; Smith, V.L.

1958-04-22T23:59:59.000Z

268

Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain  

Science Conference Proceedings (OSTI)

Motivated by the ubiquity of time series in oceanic data, the relative lack of studies of geostrophic turbulence in the frequency domain, and the interest in quantifying the contributions of intrinsic nonlinearities to oceanic frequency spectra, ...

Brian K. Arbic; Robert B. Scott; Glenn R. Flierl; Andrew J. Morten; James G. Richman; Jay F. Shriver

2012-09-01T23:59:59.000Z

269

Advection, Phase Distortion, and the Frequency Spectrum of Finescale Fields in the Sea  

Science Conference Proceedings (OSTI)

Continuous depth–time measurements of upper-ocean velocity are used to estimate the wavenumber–frequency spectrum of shear. A fundamental characteristic of these spectra is that the frequency bandwidth increases linearly with increasing ...

Robert Pinkel

2008-02-01T23:59:59.000Z

270

Electrojet-independent ionospheric extremely low frequency/very low frequency wave generation by powerful high frequency waves  

Science Conference Proceedings (OSTI)

Results of extremely low frequency/very low frequency (ELF/VLF) wave generation by intensity-modulated high frequency (HF) heaters of 3.2 MHz in Gakona, Alaska, near local solar noon during a geomagnetic quiet time, are presented to support an electrojet-independent ELF/VLF wave generation mechanism. The modulation was set by splitting the HF transmitter array into two subarrays; one was run at cw full power and the other run alternatively at 50% and 100% power modulation by rectangular waves of 2.02, 5, 8, and 13 kHz. The most effective generation was from the X-mode heater with 100% modulation. While the 8 kHz radiation has the largest wave amplitude, the spectral intensity of the radiation increases with the modulation frequency, i.e., 13 kHz line is the strongest. Ionograms recorded significant virtual height spread of the O-mode sounding echoes. The patterns of the spreads and the changes of the second and third hop virtual height traces caused by the O/X-mode heaters are distinctively different, evidencing that it is due to differently polarized density irregularities generated by the filamentation instability of the O/X-mode HF heaters.

Kuo, Spencer [Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, New York 11201 (United States); Snyder, Arnold [NorthWest Research Associates, P.O. Box 530, Stockton Springs, Maine 04981 (United States); Chang, Chia-Lie [BAE Systems-Technology Solutions, 2000 North 15th Street, Suite 1100, Arlington, Virginia 22201-2627 (United States)

2010-08-15T23:59:59.000Z

271

Stabilized radio-frequency quadrupole  

DOE Patents (OSTI)

A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

1982-09-29T23:59:59.000Z

272

Network performance measurement with periodic streams  

Science Conference Proceedings (OSTI)

This memo describes a periodic sampling method and relevant metrics for assessing the performance of IP networks. First, the memo motivates periodic sampling and addresses the question of its value as an alternative to the Poisson sampling described ...

V. Raisanen; G. Grotefeld; A. Morton

2002-11-01T23:59:59.000Z

273

Frequency Conversion of Entangled State  

E-Print Network (OSTI)

The quantum characteristics of sum-frequency process in an optical cavity with an input signal optical beam, which is a half of entangled optical beams, are analyzed. The calculated results show that the quantum properties of the signal beam can be maintained after its frequency is conversed during the intracavity nonlinear optical interaction. The frequency-conversed output signal beam is still in an entangled state with the retained other half of initial entangled beams. The resultant quantum correlation spectra and the parametric dependences of the correlations on the initial squeezing factor, the optical losses and the pump power of the sum-frequency cavity are calculated. The proposed system for the frequency conversion of entangled state can be used in quantum communication network and the calculated results can provide direct references for the design of experimental systems.

Aihong Tan; Xiaojun Jia; Changde Xie

2006-03-01T23:59:59.000Z

274

Vertically Aligned and Periodically Distributed Carbon Nanotube  

Science Conference Proceedings (OSTI)

Presentation Title, Vertically Aligned and Periodically Distributed Carbon Nanotube (CNT) ... Application of Carbon Nanotubes – Energy to Bioelectronic Sensor.

275

Experimental observation of a complex periodic window  

E-Print Network (OSTI)

The existence of a special periodic window in the two-dimensional parameter space of an experimental Chua's circuit is reported. One of the main reasons that makes such a window special is that the observation of one implies that other similar periodic windows must exist for other parameter values. However, such a window has never been experimentally observed, since its size in parameter space decreases exponentially with the period of the periodic attractor. This property imposes clear limitations for its experimental detection.

D. M. Maranhăo; M. S. Baptista; J. C. Sartorelli; I. L. Caldas

2007-12-22T23:59:59.000Z

276

High Frequency Power Modulation - TRIMET Smelters Provide ...  

Science Conference Proceedings (OSTI)

Presentation Title, High Frequency Power Modulation - TRIMET Smelters Provide Primary Control Power for Stabilizing the Frequency in the Electricity Grid.

277

High-frequency Light Reflector via Low-frequency Light Control  

E-Print Network (OSTI)

We show that the momentum of light can be reversed via the atomic coherence created by another light with one or two orders of magnitude lower frequency. Both the backward retrieval of single photons from a time-ordered Dicke state and the reflection of continuous waves by high-order photonic band gaps are analyzed. A proof-of-principle experiment with thermal Rb vapor is proposed based on presently available techniques. This holds promise for X-ray reflectors controlled by low-frequency light.

Wang, Da-Wei; Evers, Joerg; Scully, Marlan O

2013-01-01T23:59:59.000Z

278

A Minimal Baroclinic Model for the Statistical Properties of Low-Frequency Variability  

Science Conference Proceedings (OSTI)

A recent analysis of atmospheric observations has shown evidence of bimodality in the statistical distribution of wave amplitude in the ultralong (zonal wavenumber group 2–4), low frequency (period >5 days). Similar analysis of the zonal wind and ...

R. Benzi; A. Speranza; A. Sutera

1986-12-01T23:59:59.000Z

279

Forcing and Sampling of Ocean General Circulation Models: Impact of High-Frequency Motions  

Science Conference Proceedings (OSTI)

Significant inertial oscillations are present in all primitive equation ocean general circulation models when they are forced with high-frequency (period order of days) wind stress fields. At specific latitudes the energy of the wind stress ...

Steven R. Jayne; Robin Tokmakian

1997-06-01T23:59:59.000Z

280

Frequencies and Characteristics of Global Oceanic Precipitation from Shipboard Present-Weather Reports  

Science Conference Proceedings (OSTI)

Ship reports of present weather obtained from the Comprehensive Ocean-Atmosphere Data Set are analyzed for the period 1958–91 in order to elucidate regional and seasonal variations in the climatological frequency, phase. intensity, and character ...

Grant W. Petty

1995-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Low-Frequency Variations of Surface Temperature in Observations and Simulations  

Science Conference Proceedings (OSTI)

This paper documents the low-frequency (i.e., decadal) variations of surface temperature for the period 1899–1998 in observations, and in simulations conducted as part of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment ...

Timothy DelSole

2006-09-01T23:59:59.000Z

282

Low-Frequency Variability in a Baroclinic ? Channel with Land–Sea Contrast  

Science Conference Proceedings (OSTI)

Atmospheric low-frequency variability (LFV) is studied in a two-layer quasigeostrophic model. The model geometry is a periodic ? channel with flat bottom and zonally inhomogeneous thermal forcing. As a result of the idealized land–sea contrast, ...

S. Kravtsov; A. W. Robertson; M. Ghil

2003-09-01T23:59:59.000Z

283

An analysis on the mid-latitude scintillation and coherence frequency bandwidth using transionospheric VHF signals  

Science Conference Proceedings (OSTI)

An analysis was perfonned on the mid-latitude scintillation and coherence frequency bandwidth (Fcoh) using transionospheric VHF signal data. The data include 1062 events spanning from November 1997 to June 2002. Each event records FORTE satellite received VHF signals from LAPP located at Los Alamos, New Mexico. Fcohs were derived to study scintillation characteristics on diurnal and seasonal variations, as well as changes due to solar and geomagnetic activities. Comparisons to the VHFIUHF coherence frequency bandwidth studies previously reported at equatorial and mid-latitude regions are made using a 4th power frequency dependence relationship. Furthennore, a wideband ionospheric scintillation model, WBMOD, was used to estimate Fcohs and compared with our VHF Fcoh values. Our analysis indicates mid-latitude scintillation characteristics that are not previously revealed. At the VHF bottom frequency range (3035 MHz), distinguished smaller Fcohs are found in time period from sunset to midnight, in wann season from May to August, and in low solar activity years. The effects of geomagnetic storm activity on Fcoh are characterized by a sudden transition at a Kp index of 50-60. Comparisons with median Fcohs estimated from other studies validated our VHF Fcohs for daytime while an order of magnitude larger Fcohs are found for nighttime, implying a time-dependent issue in applying the 4th order power relationship. Furthermore, comparisons with WBMOD-estimated Fcohs indicated generally matched median scintillation level estimates while differences do exist for those events undergoing high geomagnetic stonn activity which may imply underestimates of scintillation level by the WBMOD in the mid-latitude regions.

Juang, Zhen [Los Alamos National Laboratory; Roussel-dupre, Robert [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

284

STAR Teaching Program Application Period | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

STAR Teaching Program Application Period STAR Teaching Program Application Period STAR Teaching Program Application Period December 28, 2012 2:30PM EST to January 31, 2013 5:30PM EST Cal Poly The Science Teacher and Researcher (STAR) Researcher program, a collaborative project of California State University, provides pre-service and early career science teachers with eight week long paid mentor and research opportunities at a national research center. Applicants must have the following: A demonstrated interest in becoming a science or mathematics teacher at the secondary level (grades 6-12) Either a California State University (CSU) student OR NSF Noyce Scholar in the United States OR a STAR Alum with two or fewer years of participation AND two or fewer years of teaching experience (first time participants must be pre-service teachers, i.e., not yet teaching full-time

285

The correlation of Abiyev's balanced squares with periodic law  

Science Conference Proceedings (OSTI)

For the first time, a perfect algorithm for writing the magic squares has been found by Abiyev. With the help of this algorithm we can write not only magic squares, but also magic cubes from any numbers of any orders. These squares have been called the ... Keywords: algorithm, correlation, magic square, periodic law, sequence, super-heavy

Asker Ali Abiyev

2011-09-01T23:59:59.000Z

286

A NEW TIMESCALE FOR PERIOD CHANGE IN THE PULSATING DA WHITE DWARF WD 0111+0018  

SciTech Connect

We report the most rapid rate of period change measured to date for a pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s mode of WD 0111+0018. The observed period change, faster than 10{sup -12} s s{sup -1}, exceeds by more than two orders of magnitude the expected rate from cooling alone for this class of slow and simply evolving pulsating WDs. This result indicates the presence of an additional timescale for period evolution in these pulsating objects. We also measure the rates of period change of nonlinear combination frequencies and show that they share the evolutionary characteristics of their parent modes, confirming that these combination frequencies are not independent modes but rather artifacts of some nonlinear distortion in the outer layers of the star.

Hermes, J. J.; Montgomery, M. H.; Winget, D. E. [Department of Astronomy, University of Texas at Austin, Austin, TX - 78712 (United States)] [Department of Astronomy, University of Texas at Austin, Austin, TX - 78712 (United States); Mullally, Fergal [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States)] [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Bischoff-Kim, A., E-mail: jjhermes@astro.as.utexas.edu [Chemistry, Physics and Astronomy Department, Georgia College and State University, Milledgeville, GA 31061 (United States)

2013-03-20T23:59:59.000Z

287

THE IMPACT OF FREQUENCY STANDARDS ON COHERENCE IN VLBI AT THE HIGHEST FREQUENCIES  

SciTech Connect

We have carried out full imaging simulation studies to explore the impact of frequency standards in millimeter and submillimeter very long baseline interferometry (VLBI), focusing on the coherence time and sensitivity. In particular, we compare the performance of the H-maser, traditionally used in VLBI, to that of ultra-stable cryocooled sapphire oscillators over a range of observing frequencies, weather conditions, and analysis strategies. Our simulations show that at the highest frequencies, the losses induced by H-maser instabilities are comparable to those from high-quality tropospheric conditions. We find significant benefits in replacing H-masers with cryocooled sapphire oscillator based frequency references in VLBI observations at frequencies above 175 GHz in sites which have the best weather conditions; at 350 GHz we estimate a 20%-40% increase in sensitivity over that obtained when the sites have H-masers, for coherence losses of 20%-10%, respectively. Maximum benefits are to be expected by using co-located Water Vapor Radiometers for atmospheric correction. In this case, we estimate a 60%-120% increase in sensitivity over the H-maser at 350 GHz.

Rioja, M.; Dodson, R. [ICRAR, University of Western Australia, Perth (Australia); Asaki, Y. [Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Chuou, Sagamihara, Kanagawa 252-5210 (Japan); Hartnett, J. [School of Physics, University of Western Australia, Perth (Australia); Tingay, S., E-mail: maria.rioja@icrar.org [ICRAR, Curtin University, Perth (Australia)

2012-10-01T23:59:59.000Z

288

Managing time  

Science Conference Proceedings (OSTI)

Professionals overwhelmed with information glut can find hope from new insights about time management.

Peter J. Denning

2011-03-01T23:59:59.000Z

289

AUTO ID FUTURE - FREQUENCY AGNOSTIC  

E-Print Network (OSTI)

Identification of information is one key to the development of intelligent decision systems of the future. Frequency agnostic automatic identification is only one step in the physical world to make physical objects identify ...

DATTA, SHOUMEN

290

Frequency regulator for synchronous generators  

DOE Patents (OSTI)

The present invention is directed to a novel frequency regulator which controls a generator output frequency for variations in both the input power to the generator and the power supplied to an uncontrolled external load. The present invention further includes over current and current balance protection devices which are relatively inexpensive to manufacture, which may be encapsulated to provide protection from the operating environment and which respond more quickly than previously known electromechanical devices.

Karlicek, Robert F. (1920 Camino Centroloma, Fullerton, CA 92633)

1982-01-01T23:59:59.000Z

291

Frequency regulator for synchronous generators  

DOE Patents (OSTI)

The present invention is directed to a novel frequency regulator which controls a generator output frequency for variations in both the input power to the generator and the power supplied to an uncontrolled external load. The present invention further includes over current and current balance protection devices which are relatively inexpensive to manufacture, which may be encapsulated to provide protection from the operating environment and which respond more quickly than previously known electromechanical devices. 11 figs.

Karlicek, R.F.

1982-08-10T23:59:59.000Z

292

SES Probationary Period | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SES Probationary Period SES Probationary Period SES Probationary Period An individual's initial appointment as an SES career appointee becomes final only after the individual has served a 1-year probationary period as a career appointee. That employee's rating official must perform an assessment of the new SES's performance during the probationary period. After the one year the selecting official must certify that the appointee performed at the level of excellence expected of a senior executive during the probationary period. When a career appointee's executive qualification have been certified by a Qualifications Review Board on the basis of special or unique qualities, as described in Sec. 317.502(c), the probationary assessment must address any executive development activities the agency identified in support of the

293

The Relationship of Collectors and Periodic Table  

Science Conference Proceedings (OSTI)

... of Chemical Element (IV)—The Relationship of Collectors and Periodic Table of ..... One Dimensional Multiferroic Nanomaterials/Nanocomposites for Solar ...

294

TIMING CIRCUIT  

DOE Patents (OSTI)

An electronic circuit is described for precisely controlling the power delivered to a load from an a-c source, and is particularly useful as a welder timer. The power is delivered in uniform pulses, produced by a thyratron, the number of pulses being controlled by a one-shot multivibrator. The starting pulse is synchronized with the a-c line frequency so that each multivlbrator cycle begins at about the same point in the a-c cycle.

Heyd, J.W.

1959-07-14T23:59:59.000Z

295

Spectral element method in time for rapidly actuated systems  

Science Conference Proceedings (OSTI)

In this paper, the spectral element (SE) method is applied in time to find the entire time-periodic or transient solution of time-dependent differential equations. The time-periodic solution is computed by enforcing periodicity of the element set. Of ... Keywords: 65D30, 65M06, 65M60, 65M70, 74H45, Aeroacoustic, Limit-cycle oscillations, Rapid excitation, Spectral element, Time periodicity, Transient response, Wave equation

Mohammad H. Kurdi; Philip S. Beran

2008-01-01T23:59:59.000Z

296

Periodic components of hand acceleration/deceleration impulses during telemanipulation  

SciTech Connect

Responsiveness is the ability of a telemanipulator to recreate user trajectories and impedance in time and space. For trajectory production, a key determinant of responsiveness is the ability of the system to accept user inputs, which are forces on the master handle generated by user hand acceleration/deceleration (a/d) impulses, and translate them into slave arm acceleration/deceleration. This paper presents observations of master controller a/d impulses during completion of a simple target acquisition task. Power spectral density functions (PSDF`s) calculated from hand controller a/d impulses were used to assess impulse waveform. The relative contributions of frequency intervals ranging up to 25 Hz for three spatially different versions of the task were used to determine which frequencies were most important. The highest relative power was observed in frequencies between 1 Hz and 6 Hz. The key frequencies related to task difficulty were in the range from 2 Hz to 8 Hz. the results provide clues to the source of the performance inhibition.

Draper, J.V. [Oak Ridge National Lab., TN (United States); Handel, S. [Tennessee Univ., Knoxville, TN (United States). Dept. of Psychology

1994-01-01T23:59:59.000Z

297

High frequency limit for single-electron pumping operations  

E-Print Network (OSTI)

In this Letter, we study the transient electron transfer phenomena of single-electron devices with alternating external gate voltages. We obtain a high frequency limit for pumping electrons one at a time in single-electron devices. Also, we find that in general the electrical current is not proportional to the frequency of the external signals in the single-electron devices, due to the strong quantum coherence tunneling effect.

Chuan-Yu Lin; Wei-Min Zhang

2010-12-04T23:59:59.000Z

298

Entropic Time  

Science Conference Proceedings (OSTI)

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.

Caticha, Ariel [Department of Physics, University at Albany-SUNY, Albany, NY 12222 (United States)

2011-03-14T23:59:59.000Z

299

Explanation of persistent high frequency density structure in coalesced bunches  

SciTech Connect

It has been observed that after the Main Ring rf manipulation of coalescing (where 5 to 13 primary bunches are transferred into a single rf bucket) the new secondary bunch displays evidence of high frequency density structure superimposed on the approximately Gaussian longitudinal bunch length distribution. This structure is persistent over a period of many seconds (hundreds of synchrotron oscillation periods). With the help of multiparticle simulation programs, an explanation of this phenomenon is given in terms of single particle longitudinal phase space dynamics. No coherent effects need be taken into account. 6 refs., 10 figs.

Jackson, Gerald P.

1988-07-01T23:59:59.000Z

300

External control of ion waves in a plasma by high frequency fields  

DOE Patents (OSTI)

An apparatus and method are described for stabilizing plasma instabilities, in a magnetically confined plasma column by transmitting into the plasma high frequency electromagnetic waves at a frequency close to the electron plasma frequency. The said frequencies, e.g., are between the plasma frequency and 1.5 times the plasma frequency at a power level below the level for producing parametric instabilities in a plasma having temperatures from below 10 eV to about 10 keV or more, at densities from below 10/sup 13/ to above 10/sup 18/ particles/cm/sup 3/. (Official Gazette)

Kaw, P.K.; Dawson, J.M.

1973-12-18T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Spectrum of Long-Period Fluctuations of Surface Wind at Marcus Island  

Science Conference Proceedings (OSTI)

Spectra of the surface wind at Marcus Island (24°N, 154°E) in the subtropical Pacific area wore constructed over a wide frequency range from 10?1 to 5 × 10?5 Hz (periods from 6 h to about three years). The major kinetic energy peak is found at a ...

Yukihiro Mori

1980-09-01T23:59:59.000Z

302

Computing traveltime and amplitude sensitivity kernels in finite-frequency tomography  

Science Conference Proceedings (OSTI)

The efficient computation of finite-frequency traveltime and amplitude sensitivity kernels for velocity and attenuation perturbations in global seismic tomography poses problems both of numerical precision and of validity of the paraxial approximation used. We investigate these aspects, using a local model parameterization in the form of a tetrahedral grid with linear interpolation in between grid nodes. The matrix coefficients of the linear inverse problem involve a volume integral of the product of the finite-frequency kernel with the basis functions that represent the linear interpolation. We use local and global tests as well as analytical expressions to test the numerical precision of the frequency and spatial quadrature. There is a trade-off between narrowing the bandpass filter and quadrature accuracy and efficiency. Using a minimum step size of 10 km for S waves and 30 km for SS waves, relative errors in the quadrature are of the order of 1% for direct waves such as S, and a few percent for SS waves, which are below data uncertainties in delay time or amplitude anomaly observations in global seismology. Larger errors may occur wherever the sensitivity extends over a large volume and the paraxial approximation breaks down at large distance from the ray. This is especially noticeable for minimax phases such as SS waves with periods >20 s, when kernels become hyperbolic near the reflection point and appreciable sensitivity extends over thousands of km. Errors becomes intolerable at epicentral distance near the antipode when sensitivity extends over all azimuths in the mantle. Effects of such errors may become noticeable at epicentral distances > 140{sup o}. We conclude that the paraxial approximation offers an efficient method for computing the matrix system for finite-frequency inversions in global tomography, though care should be taken near reflection points, and alternative methods are needed to compute sensitivity near the antipode.

Tian Yue [Department of Geosciences, Guyot Hall, Princeton University, NJ 08544 (United States)], E-mail: ytian@princeton.edu; Montelli, Raffaella [ExxonMobil Upstream Research Company, P.O. Box 22189, GW03-940A, Houston, TX 77252-2189 (United States); Nolet, Guust; Dahlen, F.A. [Department of Geosciences, Guyot Hall, Princeton University, NJ 08544 (United States)

2007-10-01T23:59:59.000Z

303

Frequency  

Science Conference Proceedings (OSTI)

... noise terms are the result of environmental changes affecting ... respond to changes in environment, so this ... is probably of broadest concern, but some ...

2002-11-19T23:59:59.000Z

304

PRECISION TIME-DELAY CIRCUIT  

DOE Patents (OSTI)

A tine-delay circuit which produces a delay time in d. The circuit a capacitor, an te back resistance, connected serially with the anode of the diode going to ground. At the start of the time delay a negative stepfunction is applied to the series circuit and initiates a half-cycle transient oscillatory voltage terminated by a transient oscillatory voltage of substantially higher frequency. The output of the delay circuit is taken at the junction of the inductor and diode where a sudden voltage rise appears after the initiation of the higher frequency transient oscillations.

Creveling, R.

1959-03-17T23:59:59.000Z

305

ARM - Field Campaign - 2001 Multi-Frequency Radar IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaigns2001 Multi-Frequency Radar IOP govCampaigns2001 Multi-Frequency Radar IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 2001 Multi-Frequency Radar IOP 2001.03.01 - 2001.09.30 Lead Scientist : Stephen Sekelsky Data Availability http://abyss.ecs.umass.edu For data sets, see below. Summary Install UMass and NOAA Aeronomy Laboratory "guest instrument" radars at the SGP CART site adjacent to the MMCR system. Both the UMass and NOAA Aeronomy Laboratory systems will run autonomously for approximately a six month period. Description Scientific hypothesis: A. Measurements from the University of Massachusetts (UMass) Cloud Profiling Radar System (CPRS) - 95/33 GHz Radar indicate that the 95 GHz channel is much less sensitive to insect clutter than the 35 GHz channel by

306

Power and Energy Measurements Low Frequency  

Science Conference Proceedings (OSTI)

... Power and Energy Measurements, Low-Frequency. Rate our Services. ... Power and Energy Measurements, Low-Frequency (56200C-56202C). ...

2013-06-24T23:59:59.000Z

307

Optimal Quantization of Periodic Task Requests on Multiple Identical Processors  

E-Print Network (OSTI)

We simplify the periodic tasks scheduling problem by making a trade off between processor load and computational complexity. A set N of periodic tasks, each characterized by its density # i , contains n possibly unique values of # i . We transform N through a process called quantization, in which each # i N is mapped onto a service level s j L, where L jjl # n and # i s j (this second condition differentiates this problem from the p-median problem on the real line). We define the Periodic Task Quantization problem with Deterministic input (PTQ-D) and present an optimal polynomial time dynamic programming solution. We also introduce the problem PTQ-S (with Stochastic input) and present an optimal solution. We examine, in a simulation study, the trade off penalty of excess processor load needed to service the set of quantized tasks over the original set, and find that, through quantization onto as few as 15 or 20 service levels, no more than 5 percent processor load is required above the amount requested. Finally, we demonstrate that the scheduling of a set of periodic tasks is greatly simplified through quantization and we present a fast online algorithm that schedules quantized periodic tasks.

Laura E. Jackson; George N. Rouskas

2003-01-01T23:59:59.000Z

308

A simple test for periodic signals in red noise  

E-Print Network (OSTI)

We demonstrate a simple method for testing the significance of peaks in the periodogram of red noise data. The procedure was designed to test for spurious periodicities in X-ray light curves of active galaxies, but can be used quite generally to test for periodic components against a background noise spectrum assumed to have a power law shape. The method provides a simple and fast test of the significance of candidate periodic signals in short, well-sampled time series such as those obtained from XMM-Newton observations of Seyfert galaxies, without the need for Monte Carlo simulations. A full account is made of the number of trials and the uncertainties inherent to the model fitting. Ignoring these subtle effects can lead to substantially overestimated significances. These difficulties motivate us to demand high standards of detection (minimum >99.9 per cent confidence) for periodicities in sources that normally show red noise spectra. The method also provides a simple means to estimate the power spectral index, which may be an interesting parameter itself, regardless of the presence/absence of periodicities.

S. Vaughan

2004-12-30T23:59:59.000Z

309

LONG-TERM PERIODICITY VARIATIONS OF THE SOLAR RADIUS  

Science Conference Proceedings (OSTI)

In order to study the long-term periodicity variations of the solar radius, daily solar radius data from 1978 February to 2000 September at the Calern Observatory are used. Continuous observations of the solar radius are difficult due to the weather, seasonal effects, and instrument characteristics. Thus, to analyze these data, we first use the Dixon criterion to reject suspect values, then we measure the cross-correlation between the solar radius and sunspot numbers. The result indicates that the solar radius is in complete antiphase with the sunspot numbers and shows lead times of 74 months relative to the sunspot numbers. The Lomb-Scargle and date compensated discrete Fourier transform methods are also used to investigate the periodicity of the solar radius. Both methods yield similar significance periodicities around {approx}1 yr, {approx}2.6 yr, {approx}3.6 yr, and {approx}11 yr. Possible mechanisms for these periods are discussed. The possible physical cause of the {approx}11 yr period is the cyclic variation of the magnetic pressure of the concentrated flux tubes at the bottom of the solar convection zone.

Qu, Z. N.; Xie, J. L. [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)] [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)

2013-01-01T23:59:59.000Z

310

TIMING APPARATUS  

DOE Patents (OSTI)

The timing device comprises an escapement wheel and pallet, a spring drive to rotate the escapement wheel to a zero position, means to wind the pretensioned spring proportional to the desired signal time, and a cam mechanism to control an electrical signal switch by energizing the switch when the spring has been wound to the desired position, and deenergizing it when it reaches the zero position. This device produces an accurately timed signal variably witain the control of the operator.

Bennett, A.E.; Geisow, J.C.H.

1956-04-17T23:59:59.000Z

311

Variable-Period Undulators for Synchrotron Radiation  

DOE Patents (OSTI)

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.

Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

2005-02-22T23:59:59.000Z

312

Frequency Dependence in Forecast Skill  

Science Conference Proceedings (OSTI)

A method is proposed to calculate measures of forecast skill for high, medium and low temporal frequency variations in the atmosphere. This method is applied to a series of 128 consecutive 1 to 10-day forecasts produced at NMC with their ...

H. M. van Den Dool; Suranjana Saha

1990-01-01T23:59:59.000Z

313

Frequency agile optical parametric oscillator  

DOE Patents (OSTI)

The frequency agile OPO device converts a fixed wavelength pump laser beam to arbitrary wavelengths within a specified range with pulse to pulse agility, at a rate limited only by the repetition rate of the pump laser. Uses of this invention include Laser radar, LIDAR, active remote sensing of effluents/pollutants, environmental monitoring, antisensor lasers, and spectroscopy.

Velsko, Stephan P. (Livermore, CA)

1998-01-01T23:59:59.000Z

314

Frequency agile optical parametric oscillator  

DOE Patents (OSTI)

The frequency agile OPO device converts a fixed wavelength pump laser beam to arbitrary wavelengths within a specified range with pulse to pulse agility, at a rate limited only by the repetition rate of the pump laser. Uses of this invention include Laser radar, LIDAR, active remote sensing of effluents/pollutants, environmental monitoring, antisensor lasers, and spectroscopy. 14 figs.

Velsko, S.P.

1998-11-24T23:59:59.000Z

315

Quantum Algorithm for Computing the Period Lattice of an Infrastructure  

E-Print Network (OSTI)

We present a quantum algorithm for computing the period lattice of infrastructures of fixed dimension. The algorithm applies to infrastructures that satisfy certain conditions. The latter are always fulfilled for infrastructures obtained from global fields, i.e., algebraic number fields and function fields with finite constant fields, as described in [Fon11]. The first of our main contributions is a rigorous and complete proof that the running time of the algorithm is polynomial in the logarithm of the determinant of the period lattice and exponential in the dimension n. The second main contribution is the determination of an explicit lower bound on the success probability of our algorithm which improves on the bounds given in the works of Hallgren and Schmidt and Vollmer. The exponential scaling seems inevitable because the best currently known methods for carrying out fundamental arithmetic operations in infrastructures obtained from algebraic number fields take exponential time. In contrast, the problem of...

Fontein, Felix

2011-01-01T23:59:59.000Z

316

Orientation dynamics of weakly Brownian particles in periodic viscous flows  

E-Print Network (OSTI)

Evolution equations for the orientation distribution of axisymmetric particles in periodic flows are derived in the regime of small but non-zero Brownian rotations. The equations are based on a multiple time scale approach that allows fast computation of the relaxation processes leading to statistical equilibrium. The approach has been applied to the calculation of the effective viscosity of a thin disk suspension in gravity waves.

Piero Olla

2005-07-12T23:59:59.000Z

317

Coordinated Enhanced Observing Period (CEOP) International Workshop  

Science Conference Proceedings (OSTI)

The Coordinated Enhanced Observing Period (CEOP) International Workshop, sponsored by NOAA Office of Global Programs and NASA Land Surface Hydrology Program, was held on 27 February 1 March 2001 at NASA's Goddard Space Flight Center, Greenbelt, ...

Michael G. Bosilovich; Rick Lawford

2002-10-01T23:59:59.000Z

318

Mars Atmosphere Pressure Periodicities from Viking Observations  

Science Conference Proceedings (OSTI)

The first martian year of pressure data taken by the Viking landers on Mars is subjected to power spectrum analysis. The analysis suggests that strong periodicities are present in the martian atmosphere, especially at the high-latitude (48°N) ...

R. D. Sharman; J. A. Ryan

1980-09-01T23:59:59.000Z

319

Coupling Impedance of a Periodic Array of Diaphragms (Erratum)  

SciTech Connect

A method is presented for calculating the high-frequency longitudinal and transverse coupling impedances in a periodic array of diaphragms in a circular perfectly conducting pipe. The method is based on Weinstein's theory of diffraction of a plane electromagnetic wave on a stack of halfplanes. Using Weinstein's solution, it is shown that the problem of finding the beam field in the pipe reduces to an effective boundary condition at the radius of the diaphragms that couples the longitudinal electric field with the azimuthal magnetic one. Solving Maxwell's equations with this boundary condition leads to simple formulae for Z{sub long} and Z{sub tr}. A good agreement with a numerical solution of the problem found by other authors is demonstrated.

Stupakov, G.V.; /SLAC

2012-05-24T23:59:59.000Z

320

The structure of cosmic time  

E-Print Network (OSTI)

Following the approach of Julien Lesgourgues [1], we analyze the mathematical structure of the time co-ordinate of present day cosmological models, where these models include a cosmological constant term to account for the observed acceleration of the universe [2], [3]: we find that in all cases, except for a set of measure zero in the parameter space, the time is given by an (abelian) integral on a torus; the imaginary period of this integral then gives a natural periodicity in imaginary time for the universe; following Stephen Hawking [4], [5], this periodicity may be interpreted either as giving a fundamental mass scale for the universe, or (using Planck’s constant) a fundamental temperature, or both. The precise structure that emerges suggests that the structure of time can be regarded as an order parameter arising perhaps in a phase transition in the early universe; one might hope that this structure

George Sparling

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

High resolution time interval meter  

DOE Patents (OSTI)

Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.

Martin, A.D.

1986-05-09T23:59:59.000Z

322

Radio Frequency Identification Tags - Active Tags ...  

Selectable, license free, RF frequency bands; Ultra low power sleep mode; Miniaturized, encapsulated bendable packaging;

323

MILLIHERTZ QUASI-PERIODIC OSCILLATIONS AND THERMONUCLEAR BURSTS FROM TERZAN 5: A SHOWCASE OF BURNING REGIMES  

Science Conference Proceedings (OSTI)

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.

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

324

Radio frequency coaxial feedthrough device  

DOE Patents (OSTI)

A radio frequency coaxial vacuum feedthrough is provided which utilizes a cylindrical ceramic vacuum break formed of an alumina ceramic. The cylinder is coaxially disposed and brazed between tapered coaxial conductors to form a vacuum sealed connection between a pressurized upstream coaxial transmission line and a utilization device located within a vacuum container. The feedthrough provides 50 ohm matched impedance RF feedthrough up to about 500 MHz at power levels in the multimegawatt range.

Owens, Thomas L. (Kingston, TN); Baity, Frederick W. (Oak Ridge, TN); Hoffman, Daniel J. (Oak Ridge, TN); Whealton, John H. (Oak Ridge, TN)

1987-01-01T23:59:59.000Z

325

Variable frequency microwave furnace system  

DOE Patents (OSTI)

A variable frequency microwave furnace system designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity for testing or other selected applications. The variable frequency microwave furnace system includes a microwave signal generator or microwave voltage-controlled oscillator for generating a low-power microwave signal for input to the microwave furnace. A first amplifier may be provided to amplify the magnitude of the signal output from the microwave signal generator or the microwave voltage-controlled oscillator. A second amplifier is provided for processing the signal output by the first amplifier. The second amplifier outputs the microwave signal input to the furnace cavity. In the preferred embodiment, the second amplifier is a traveling-wave tube (TWT). A power supply is provided for operation of the second amplifier. A directional coupler is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter is provided for measuring the power delivered to the microwave furnace. A second power meter detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load. 5 figs.

Bible, D.W.; Lauf, R.J.

1994-06-14T23:59:59.000Z

326

Periodic invariant, general relativity predictions and origin of universe  

E-Print Network (OSTI)

A general form of space-time invariant called periodic invariant is proposed in which the special relativity invariant appear as a special case. This leads to invariant force-energy relation which when used in conjunction with suitably modified Newtonian orbital energy equation yields equations for gravitational redshift and bending of light without utilizing Riemannian geometry and geodesic trajectories. These derivations allow constant velocity of light and are later shown to satisfy Einstein's field equations and provide alternative to Schwarzschild solution. Perihelic precession theory of general relativity is retained unaltered but the equation of planet motion and the solution of the radial vector are improved to yield exact two body solution that satisfies Einstein's field equations. The periodic invariant is based on the concept that the time is a periodic phenomenon. This theory dubbed periodic relativity (PR) does not contradict the lowest order predictions of geneal relativity but differs in second order terms. The limiting radius of the event horizon in PR is half the value of the Schwarzschild radius. The theory leads to the derivation of quantum invariant which can vanish in an absolute sense resulting in a singularity implying a universe beginning with a vibration in an unmanifested state of primal energy eventually followed by inflation of the Lambda-CDM model. In PR every two body system can deviate differently from the flat Minkowski metric. Verification of PR requires inclusion of proper time interval of planet as an observable orbital parameter to ephemerides. The theory provides very accurate solutions for the Pioneer anomaly and the rotation curves of galaxies outside the framework of general relativity.

Vikram H. Zaveri

2007-07-31T23:59:59.000Z

327

High-frequency electric field measurement using a toroidal antenna  

DOE Patents (OSTI)

A simple and compact method and apparatus for detecting high frequency electric fields, particularly in the frequency range of 1 MHz to 100 MHz, uses a compact toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field.

Lee, Ki Ha (Lafayette, CA)

2002-01-01T23:59:59.000Z

328

Solar Wind Oscillations With a 1.3 Year Period  

E-Print Network (OSTI)

. The IMP-8 and Voyager 2 spacecraft have ecently detected a very strong modulation in the solar wind d w speed with an approximately 1.3 year period. Combine ith evidence from long-term auroral and magnetometer o studies, this suggests that fundamental changes in the Sun ccur on a roughly 1.3 year time scale. Introduction The Sun emits a continuous stream of ionized particles s d called the solar wind. This wind is not constant, but varie ue to changes on the Sun. Strong periodicities in the solar ) [ wind linked with the solar rotation period (roughly 25 days Neugebauer and Snyder, 1966] and the solar cycle , 1 [Neugebauer, 1975; Bridge, 1977; Lazarus and McNutt 990] have been observed. Periodicities ranging from 51 to r s 256 days have been reported both in solar wind and in othe olar observations (see Villanueva [1994] and references a therein). Solar cycle variations of sunspot numbers and uroral activity are well established [see review by Silverman, 1992]. The IMP...

John Richardson Karolen; John D. Richardson; Karolen I. Paularena; John W. Belcher; Alan J. Lazarus

1994-01-01T23:59:59.000Z

329

Pulsating B-type stars in the open cluster NGC 884: frequencies, mode identification and asteroseismology  

E-Print Network (OSTI)

Recent progress in the seismic interpretation of field beta Cep stars has resulted in improvements of the physics in the stellar structure and evolution models of massive stars. Further asteroseismic constraints can be obtained from studying ensembles of stars in a young open cluster, which all have similar age, distance and chemical composition. We present an observational asteroseismology study based on the discovery of numerous multi-periodic and mono-periodic B-stars in the open cluster NGC 884. We describe a thorough investigation of the pulsational properties of all B-type stars in the cluster. Overall, our detailed frequency analysis resulted in 115 detected frequencies in 65 stars. We found 36 mono-periodic, 16 bi-periodic, 10 tri-periodic, and 2 quadru-periodic stars and one star with 9 independent frequencies. We also derived the amplitudes and phases of all detected frequencies in the U, B, V and I filter, if available. We achieved unambiguous identifications of the mode degree for twelve of the de...

Saesen, S; Aerts, C; Miglio, A; Carrier, F

2013-01-01T23:59:59.000Z

330

Public Comment Period Re-Opened for the Uranium Leasing Program PEIS |  

NLE Websites -- All DOE Office Websites (Extended Search)

Public Comment Period Re-Opened for the Uranium Leasing Program Public Comment Period Re-Opened for the Uranium Leasing Program PEIS Public Comment Period Re-Opened for the Uranium Leasing Program PEIS May 28, 2013 - 5:37pm Addthis Public Comment Period Re-Opened for the Uranium Leasing Program PEIS The U.S. Department of Energy is re-opening the public comment period for the Draft Uranium Leasing Program Programmatic Environmental Impact Statement (Draft ULP PEIS, DOE/EIS-0472D). DOE made the Draft ULP PEIS available for public comment on March 15, 2013 (78 FR 16500). The public comment period for the Draft ULP PEIS originally was to end on May 16, 2013, and an extension to May 31, 2013 was announced on April 23, 2013 (78 FR 23926). In response to a public request for additional review time, DOE re-opens the public comment period, which will now close on July 1,

331

Mechanisms of Monsoon Low-Frequency Variability: Surface Hydrological Effects  

Science Conference Proceedings (OSTI)

Observations indicate that monsoon systems are characterized by orderly large-scale and low-frequency variations. With a time scale of two weeks and sometimes longer, regions of ascending motion are observed to form to the north of the equator ...

Peter J. Webster

1983-09-01T23:59:59.000Z

332

High-Frequency Radar Mapping of Surface Currents Using WERA  

Science Conference Proceedings (OSTI)

A dual-station high-frequency Wellen Radar (WERA), transmitting at 16.045 MHz, was deployed along the west Florida shelf in phased array mode during the summer of 2003. A 33-day, continuous time series of radial and vector surface current fields ...

Lynn K. Shay; Jorge Martinez-Pedraja; Thomas M. Cook; Brian K. Haus; Robert H. Weisberg

2007-03-01T23:59:59.000Z

333

Frequency–Wavenumber Spectrum for GATF, Phase I Rainfields  

Science Conference Proceedings (OSTI)

The oceanic rainfall frequency-wavenumber spectrum and its associated space-time correlation have been evaluated from subsets of GATE Phase 1 data. The records, of a duration of 4 days, were sampled at 15 minute intervals in 4 × 4 km grid boxes ...

Shoichiro Nakamoto; Juan B. Valdés; Gerald R. North

1990-09-01T23:59:59.000Z

334

Adaptive Real-Time Methodology for Optimizing Energy-Efficient...  

NLE Websites -- All DOE Office Websites (Extended Search)

Email Adaptive Real-Time Methodology for Optimizing Energy-Efficient Computing Dynamic voltage and frequency scaling (DVFS) is an effective way to reduce energy and power...

335

Digestion time  

NLE Websites -- All DOE Office Websites (Extended Search)

Digestion time Digestion time Name: Don Mancosh Location: N/A Country: N/A Date: N/A Question: I have always given the rule of thumb in class that material we eat is with us for about 24 hours before exiting the body. The question arises about the time value of liquids. Getting a big coke prior to a 3 hour drive generally means that there will be a stop along the way. Is there a generalization made about liquids in the body similar to the one for solid food? Replies: A physician would give a better answer, but I hazard this: the only liquids which people consume (deliberately) in significant quantities are water, ethyl alcohol and various oils. Water and alcohol are absorbed on a time scale of seconds to minutes through the mouth, stomach and digestive tract. The oils are huge molecules, so I'd guess like any other greasy food they get absorbed in the upper digestive tract. Some of them, perhaps the longest and most nonpolar, are not absorbed at all --- cf. the old-time remedy of mineral oil for constipation --- so there should be some average time-before-what's-left-is-excreted such as you're looking for, and my (wild) guess is that it would not differ substantially from that for food. You can define an average lifetime in the body for alcohol, since the natural level is zero. Rough guidelines are widespread in the context of drunk driving laws. But this is not really possible for water. One's body is normally full up to the brim with water, and there's no way for the body to distinguish between water molecules recently absorbed and molecules that've been moping around since the Beatles split up. Thus the water entering the toilet bowl after the pit stop is not in general the same water as was in the big coke. If you were to consider for water just the average time between drinking and peeing, it would seem to depend strongly on how well hydrated the body was before the drink, and how much was drunk. During sustained heavy exertion in the sun and dry air one can easily drink a pint of water an hour without peeing at all. On the other hand, if one is willing to drink enough water fast enough, so as to establish a high excess of body water one can pee 8 ounces 15 minutes or less after drinking 8 ounces.

336

New approach of determinations of earthquake moment magnitude using near earthquake source duration and maximum displacement amplitude of high frequency energy radiation  

SciTech Connect

The new approach method to determine the magnitude by using amplitude displacement relationship (A), epicenter distance ({Delta}) and duration of high frequency radiation (t) has been investigated for Tasikmalaya earthquake, on September 2, 2009, and their aftershock. Moment magnitude scale commonly used seismic surface waves with the teleseismic range of the period is greater than 200 seconds or a moment magnitude of the P wave using teleseismic seismogram data and the range of 10-60 seconds. In this research techniques have been developed a new approach to determine the displacement amplitude and duration of high frequency radiation using near earthquake. Determination of the duration of high frequency using half of period of P waves on the seismograms displacement. This is due tothe very complex rupture process in the near earthquake. Seismic data of the P wave mixing with other wave (S wave) before the duration runs out, so it is difficult to separate or determined the final of P-wave. Application of the 68 earthquakes recorded by station of CISI, Garut West Java, the following relationship is obtained: Mw = 0.78 log (A) + 0.83 log {Delta}+ 0.69 log (t) + 6.46 with: A (m), d (km) and t (second). Moment magnitude of this new approach is quite reliable, time processing faster so useful for early warning.

Gunawan, H.; Puspito, N. T.; Ibrahim, G.; Harjadi, P. J. P. [ITB, Faculty of Earth Sciences and Tecnology (Indonesia); BMKG (Indonesia)

2012-06-20T23:59:59.000Z

337

Dynamic Response of a Rotor-air Bearing System Due to Base Induced Periodic Motions  

E-Print Network (OSTI)

Oil-free microturbomachinery (MTM) are inevitably subjected to base or foundation excitations: multiple periodic load excitations from internal combustion (IC) engines in turbochargers, for example. Too large base excitations can produce severe damage, even failure, due to hard collision or rubbing contact between a rotor and its bearings. Therefore, it is paramount to evaluate the reliability of rotor-air bearing systems to withstanding base load excitations. In 2008, intermittent shock excitations, up to 30 g (pk-pk), were introduced to a test rig consisting of a rotor (0.825 kg) supported on two hybrid flexure pivot tilting pad gas bearings (FPTPBs). The experiments demonstrated the reliability of the gas bearings to withstanding external transient load excitations. Presently, a shaker delivers periodic load excitations to the base plate supporting the test rig. The whole system, weighing 48 kg, is supported on two soft coil springs and its lowest natural frequency is ~5 Hz. The rod connecting the shaker to the base plate is not affixed rigidly to the test rig base. The rod merely pushes on the base plate and hence the induced based motions are intermittent with multiple impacts and frequencies. As with most practical conditions, the base motion frequencies (5-12 Hz) are low respective to the operating speed of the rotor-bearing system. Rotor speed coast down tests evidence the rotor-bearing system natural frequency when the gas bearings are supplied with feed pressures increasing from 2.36 to 5.08 bar (ab). Shaker excitation induced rotor response, relative to the bearing housings, contains the main input frequency (5-12 Hz) and its super harmonics; and because of the intermittency of the base motions, it also excites the rotor-bearing system natural frequency, with smaller motion amplitudes than synchronous motion components. The excitation of the system natural frequency does not mean rotordynamic instability. With base induced motions, the rotor motion amplitude at the system natural frequency increases as the gas bearing feed pressure decreases, as the rotor speed increases, and as the shaker input excitation frequency increases (5-12 Hz). Hence, the test rotor-air bearing system is highly sensitive to base motions, intermittent in character, in particular when the gas bearings are supplied with a low feed pressure. Predicted rotor motion responses obtained from XLTRC2 and an analytical rigid rotor model, both including the (measured) periodic base motions, show good correlation with the measurements. The research results demonstrate further the applicability of gas bearings into oil-free high speed MTM.

Niu, Yaying

2009-08-01T23:59:59.000Z

338

Periodic cyclic homology of certain nuclear algebras.  

E-Print Network (OSTI)

Relying of properties of the inductive tensor product, we construct cyclic type homology theories for certain nuclear algebras. In this context we establish continuity theorems. We compute the periodic cyclic homology of the Schwartz algebra of p-adic GL(n) in terms of compactly supported de Rham cohomology of the tempered dual of GL(n).

Jacek Brodzki; Roger Plymen

339

Periodically kicked hard oscillators G. A. Cecchi  

E-Print Network (OSTI)

Periodically kicked hard oscillators G. A. Cecchi Departamento de Fisica, U.N.L.P.,Argentina D. L for publication 25 November 1992) A model of a hard oscillator with analytic solution is presented. Its behavior forcing, and is intrinsic to hard oscillators; it is characterized by discontinuous circle maps

Magnasco, Marcelo Osvaldo

340

Spatiotemporal periodical pattern mining in traffic data  

Science Conference Proceedings (OSTI)

The widespread use of road sensors has generated huge amount of traffic data, which can be mined and put to various different uses. Finding frequent trajectories from the road network of a big city helps in summarizing the way the traffic behaves in ... Keywords: KL-divergence, density-based clustering, periodic patterns, probability distribution matrices, road network, spatiotemporal data, traffic data

Tanvi Jindal, Prasanna Giridhar, Lu-An Tang, Jun Li, Jiawei Han

2013-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Design of periodic beam-transport systems  

SciTech Connect

Periodic beam-transport systems have several advantages including insensitivity to errors, minimum magnet apertures, and use of standardized components. A simple procedure is given for the design of modules, with and without bending magnets, that have the same matched beam properties. These modules can be combined in certain ways to produce systems that are achromatic and require a minimum number of matching elements.

Farrell, J.A.

1983-01-01T23:59:59.000Z

342

Periodic register saturation in innermost loops  

Science Conference Proceedings (OSTI)

This article treats register constraints in high performance codes and embedded VLIW computing, aiming to decouple register constraints from instruction scheduling. It extends the register saturation (RS) concept to periodic instruction schedules, i.e., ... Keywords: Code analysis, Code optimisation, Cyclic register allocation, Instruction level parallelism, Register saturation, Software pipelining

Sid-Ahmed-Ali Touati; Zsolt Mathe

2009-04-01T23:59:59.000Z

343

Reactor control rod timing system. [LMFBR  

DOE Patents (OSTI)

A fluid driven jet-edge whistle timing system is described 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.

Wu, P.T.K.

1980-03-18T23:59:59.000Z

344

Order Frequency Doses Distributed to Provider per Year  

E-Print Network (OSTI)

Economic Order Quantity (EOQ) is used to manage publicly-funded vaccine ordering and distribution more effectively. EOQ balances provider order size, order frequency, the timing of orders, and storage and handling to minimize costs and improve efficiencies as orders flow through the system. EOQ is one of several Vaccine Management Business Improvement Project (VMBIP) Continuous Quality Improvement initiatives offered by CDC to help manage publicly-funded vaccine orders by using industry best practices. There are two key components of EOQ: vaccine order frequency and two-week order windows. EOQ assigns a vaccine order frequency (i.e., monthly, bimonthly, or quarterly) based on the size of the population served with publicly-funded vaccine by each provider. Vaccine order frequency refers to how often a provider should place an order. EOQ excludes direct-shipped vaccine, influenza vaccine (seasonal and H1N1), and vaccine on allocation for less than six months, and also enables grantees to assign a different order frequency to certain providers based on unique characteristics at those provider sites. EOQ is also tailored for grantees in which McKesson Specialty Distribution does not ship directly to providers. Standard EOQ order frequencies are as follows:

unknown authors

2010-01-01T23:59:59.000Z

345

Dynamics of periodic structures in an extended laser spark  

SciTech Connect

The time scans of the intrinsic and scattered heating radiations of plasma foci, arising in the spark channel of the optical gas breakdown in a Bessel beam, were investigated. The experiments were carried out in argon at atmospheric pressure by using the heating radiation from a powerful nanosecond neodymium laser. The influence of independent preionisation and of the presence of aerosol particles was studied separately. The results indicate the appearance of bright foci against the background of the initially almost homogeneous plasma. The location of the foci in the longitudinal direction and the dynamics of the emitted radiation by them make it possible to assign the observed inhomogeneities to two quasi-periodic structures with periods differing almost by an order of magnitude. The above structures result from the operation of various mechanisms of the formation of inhomogeneities. (interaction of laser radiation with matter. laser plasma)

Bychkov, S S; Gorlov, S V; Makarov, A V; Margolin, L Ya; Pyatnitskii, Lev N; Tal'virskii, A D [Scientific Association for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation)

1999-03-31T23:59:59.000Z

346

The Response of Long-Span Bridges to Low Frequency, Near-Fault Earthquake Ground Motions  

SciTech Connect

Historical seismic hazard characterizations did not include earthquake ground motion waveforms at frequencies below approximately 0.2 Hz (5 seconds period). This resulted from limitations in early strong motion instrumentation and signal processing techniques, a lack of measurements in the near-field of major earthquakes and therefore no observational awareness, and a delayed understanding in the engineering community of the potential significance of these types of motions. In recent years, there is a growing recognition of the relevance of near-fault, low frequency motions, particularly for long-period structures such as large bridges. This paper describes a computationally based study of the effects of low frequency (long-period) near-fault motions on long-span bridge response. The importance of inclusion of these types of motions for long span cable supported bridges is demonstrated using actual measured broad-band, near-fault motions from large earthquakes.

McCallen, David; Astaneh-Asl, A.; Larsen, S.C.; Hutchings, Larry

2009-02-27T23:59:59.000Z

347

The Unique Frequency Spectrum of the Blazhko RRc Star LS Her  

E-Print Network (OSTI)

The Blazhko effect in RR Lyrae stars is still poorly understood theoretically. Stars with multiple Blazhko periods or in which the Blazhko effect itself varies are particularly challenging. This study investigates the Blazhko effect in the RRc star LS Her. Detailed VRI CCD photometry has been performed on 63 nights during six months. LS Her is confirmed to have a Blazhko period of 12.75+/-0.02 days. However, where normally the side frequencies of the Blazhko triplet are expected, an equidistant group of three frequencies is found on both sides of the main pulsation frequency. As a consequence the period and amplitude of the Blazhko effect itself vary in a cycle of 109+/-4 days. LS Her is a unique object turning out to be very important in the verification of the theories for the Blazhko effect.

Patrick Wils; Stelios Kleidis; Eric Broens

2008-04-01T23:59:59.000Z

348

The Unique Frequency Spectrum of the Blazhko RRc Star LS Her  

E-Print Network (OSTI)

The Blazhko effect in RR Lyrae stars is still poorly understood theoretically. Stars with multiple Blazhko periods or in which the Blazhko effect itself varies are particularly challenging. This study investigates the Blazhko effect in the RRc star LS Her. Detailed VRI CCD photometry has been performed on 63 nights during six months. LS Her is confirmed to have a Blazhko period of 12.75+/-0.02 days. However, where normally the side frequencies of the Blazhko triplet are expected, an equidistant group of three frequencies is found on both sides of the main pulsation frequency. As a consequence the period and amplitude of the Blazhko effect itself vary in a cycle of 109+/-4 days. LS Her is a unique object turning out to be very important in the verification of the theories for the Blazhko effect.

Wils, Patrick; Broens, Eric

2008-01-01T23:59:59.000Z

349

Projection-based partial periodic pattern mining for event sequences  

Science Conference Proceedings (OSTI)

Partial periodic pattern mining is one of the important issues in the field of data mining due to its practical applications. A partial periodic pattern consists of some periodic and non-periodic events in a specific period length, and is repeated with ... Keywords: Data mining, Encoding, Partial periodic pattern, Projection, Sequential pattern

Kung-Jiuan Yang; Tzung-Pei Hong; Yuh-Min Chen; Guo-Cheng Lan

2013-08-01T23:59:59.000Z

350

Avoiding low frequency noise in packaged HVAC equipment  

Science Conference Proceedings (OSTI)

The purpose of this article is to help those involved in the design and commissioning of packaged HVAC systems to understand the root causes of low frequency noise problems and how to avoid many of them at the design stage. In the 1980's, two things happened to dramatically change the types of noise problems encountered in typical new construction. The first was the introduction of new energy regulations that favored variable air volume (VAV) distribution systems over constant volume air distribution systems. A by-product of VAV design is that mid- and high frequency sound pressure levels produced by current air terminal devices and diffusers in many applications are significantly lower than in the past. The second factor was a trend away from the use of built-up central station fan equipment in favor of packaged, floor-by-floor air handlers or rooftop units. As a result, today's HVAC system noise problems are not confined to just the roar and hiss of the past, but now include intense low frequency rumble and time modulation. Indeed, most current noise problems in modern buildings occur in the frequency range well below 250 Hz. A large fraction of these are a result of the dominant sound pressure levels in the 12 to 40 Hz region. These factors, combined with a substantial increase in the level of low frequency sound from the rest of the system, can produce a non-neutral, time modulated, rumbly sounding background noise that many people find objectionable.

Ebbing, C.E. (Carrier Corp., Syracuse, NY (United States). Commercial Unitary Division); Blazier, W.E.Jr. (Warren Blazier Associates, San Francisco, CA (United States))

1993-06-01T23:59:59.000Z

351

Numerical Simulation of a 4-Day Early Spring Storm Period in the Black Hills  

Science Conference Proceedings (OSTI)

This paper illustrates the potential for mesoscale models to depict the distribution of precipitation in orographic situations. The study covers a 4-day time period in April 1995. The domain of the numerical model covers much of western South ...

R. D. Farley; D. L. Hjermstad; H. D. Orville

2000-08-01T23:59:59.000Z

352

Radio frequency sustained ion energy  

SciTech Connect

Electromagnetic (E.M.) energy injection method and apparatus for producing and sustaining suprathermal ordered ions in a neutral, two-ion-species, toroidal, bulk equilibrium plasma. More particularly, the ions are produced and sustained in an ordered suprathermal state of existence above the average energy and velocity of the bulk equilibrium plasma by resonant rf energy injection in resonance with the natural frequency of one of the ion species. In one embodiment, the electromagnetic energy is injected to clamp the energy and velocity of one of the ion species so that the ion energy is increased, sustained, prolonged and continued in a suprathermal ordered state of existence containing appreciable stored energy that counteracts the slowing down effects of the bulk equilibrium plasma drag. Thus, selective deuteron absorption may be used for ion-tail creation by radio-frequency excitation alone. Also, the rf can be used to increase the fusion output of a two-component neutral injected plasma by selective heating of the injected deuterons.

Jassby, Daniel L. (Princeton, NJ); Hooke, William M. (Princeton, NJ)

1977-01-01T23:59:59.000Z

353

Frequency synthesis using MEMS piezoelectric resonators  

E-Print Network (OSTI)

(cont.) Ultimately, this thesis presents two approaches to frequency synthesizer design. The first uses frequency windows of approximately 200 MHz. The 800 MHz to 1 GHz matching network is presented in detail along with ...

Calhoun, Paul Jacob, 1979-

2004-01-01T23:59:59.000Z

354

Definition: Frequency Bias Setting | Open Energy Information  

Open Energy Info (EERE)

Frequency Bias, Balancing Authority, frequency response, smart grid References Glossary of Terms Used in Reliability Standards An inl LikeLike UnlikeLike You like this.Sign...

355

Universal Frequency Spectra of Surface Meteorological Fluctuations  

Science Conference Proceedings (OSTI)

Statistical characteristics of surface meteorology are examined in terms of frequency spectra. According to a recent work using hourly data over 50 yr in the Antarctic, the frequency spectra have a characteristic shape proportional to two ...

Chikara Tsuchiya; Kaoru Sato; Tomoe Nasuno; Akira T. Noda; Masaki Satoh

2011-09-01T23:59:59.000Z

356

Property:Maximum Wave Height(m) at Wave Period(s) | Open Energy Information  

Open Energy Info (EERE)

Wave Height(m) at Wave Period(s) Wave Height(m) at Wave Period(s) Jump to: navigation, search Property Name Maximum Wave Height(m) at Wave Period(s) Property Type String Pages using the property "Maximum Wave Height(m) at Wave Period(s)" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + 10.0 + 10-ft Wave Flume Facility + 10.0 + 11-ft Wave Flume Facility + 10.0 + 2 2-ft Flume Facility + 10.0 + 3 3-ft Wave Flume Facility + 10.0 + 5 5-ft Wave Flume Facility + 10.0 + 6 6-ft Wave Flume Facility + 10.0 + A Alden Large Flume + 0.0 + Alden Wave Basin + 1.0 + C Chase Tow Tank + 3.1 + Coastal Harbors Modeling Facility + 2.3 + Coastal Inlet Model Facility + 2.3 + D Davidson Laboratory Tow Tank + 4.0 + DeFrees Large Wave Basin + 3.0 + DeFrees Small Wave Basin + 3.0 +

357

Upgrade of NSLS timing system  

SciTech Connect

We report on the progress of the new NSLS timing system. There are three types of requirements for NSLS timing system: clocks, synchronization and trigger circuits. All ring revolution frequency clocks are generated using ECL and high speed TTL logic. The synchronization circuits allows to fill both storage rings with any bunch pattern. The triggers are generated by using commercially available digital delay generators. The delay unit`s outputs are ultrastable, with a resolution of 5 ps, and are programmed by computer via IEEE 488 interface. The block diagrams, description of all major timing components and the present status are provided in this paper.

Singh, O.; Ramamoorthy, S.; Sheehan, J.; Smith, J.

1995-05-01T23:59:59.000Z

358

A Study of Target Frequency Bond for Frequency Control Performance Score Calculations in an Isolated System.  

E-Print Network (OSTI)

??Power system frequency is one of the key performance indices of system operation. Abnormal frequency deviations would incur negative impacts to power equipments and service… (more)

Lee, Hung-hsi

2010-01-01T23:59:59.000Z

359

Sample Observations from the 2001.Multi-Frequency Radar IOP  

NLE Websites -- All DOE Office Websites (Extended Search)

Sample Observations from the 2001 Sample Observations from the 2001 Multi-Frequency Radar IOP C. R. Williams Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder, Colorado C. R. Williams and K. S. Gage National Oceanic and Atmospheric Administration Aeronomy Laboratory Boulder, Colorado L. Leon and S. Cruz-Pol University of Puerto Rico Mayaguez Campus S. M. Sekelsky Microwave Remote Sensing Laboratory University of Massachusetts Amherst, Massachusetts Introduction The 2001 Multi-Frequency Radar Intensive Operational Period (IOP) was designed to collect a long dataset of W-band (95 GHz), Ka-band (35 GHz), and S-band (2.8 GHz) vertical profiling observations to investigate insect scattering and precipitating particle scattering above the Southern Great Plains

360

Heterodyne laser instantaneous frequency measurement system  

DOE Patents (OSTI)

A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of the frequency during the pulse.

Wyeth, Richard W. (Livermore, CA); Johnson, Michael A. (Pleasanton, CA); Globig, Michael A. (Livermore, CA)

1990-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Heterodyne laser instantaneous frequency measurement system  

DOE Patents (OSTI)

A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of th frequency during the pulse.

Wyeth, Richard W. (Livermore, CA); Johnson, Michael A. (Pleasanton, CA); Globig, Michael A. (Livermore, CA)

1989-01-01T23:59:59.000Z

362

Fast-scale bifurcation . . . converters and effects of incompatible periodicities  

E-Print Network (OSTI)

In this paper, we derive the discrete-time model for the power-factor-correction (PFC) buck-boost converter in terms of a stroboscopic switching map. Fast-scale instability is analysed through a fold diagram, which exposes the periodicity of the operation as well as the locations of the critical phase angles of the line voltage at which instability begins to occur along a half-line cycle. The asymmetrical locations of the critical phase angles along a half-line cycle is explained in terms of ‘underdeveloped’ bifurcation. Border collision bifurcations are observed and analysed in detail.

Jianlong Zou; Xikui Ma; Chi K. Tse; Dong Dai

2006-01-01T23:59:59.000Z

363

Massive Quantum Memories by Periodically Inverted Dynamic Evolutions  

E-Print Network (OSTI)

We introduce a general scheme to realize perfect quantum state reconstruction and storage in systems of interacting qubits. This novel approach is based on the idea of controlling the residual interactions by suitable external controls that, acting on the inter-qubit couplings, yield time-periodic inversions in the dynamical evolution, thus cancelling exactly the effects of quantum state diffusion. We illustrate the method for spin systems on closed rings with XY residual interactions, showing that it enables the massive storage of arbitrarily large numbers of local states, and we demonstrate its robustness against several realistic sources of noise and imperfections.

S. M. Giampaolo; F. Illuminati; A. Di Lisi; G. Mazzarella

2005-06-27T23:59:59.000Z

364

MASSIVE QUANTUM MEMORIES BY PERIODICALLY INVERTED DYNAMIC EVOLUTIONS  

E-Print Network (OSTI)

We introduce a general scheme to realize perfect quantum state reconstruction and storage in systems of interacting qubits. This novel approach is based on the idea of controlling the residual interactions by suitable external controls that, acting on the inter-qubit couplings, yield time-periodic inversions in the dynamical evolution, thus cancelling exactly the effects of quantum state diffusion. We illustrate the method for spin systems on closed rings with XY residual interactions, showing that it enables the massive storage of arbitrarily large numbers of local states, and we demonstrate its robustness against several realistic sources of noise and imperfections. Keywords: Quantum Information; Quantum Control; Spin Systems. 1.

S. M. Giampaolo; F. Illuminati; A. Di Lisi; G. Mazzarella

2005-01-01T23:59:59.000Z

365

Method and means for generating a synchronizing pulse from a repetitive wave of varying frequency  

DOE Patents (OSTI)

An event that occurs repetitively at continuously changing frequencies can be used to generate a triggering pulse which is used to synchronize or control. The triggering pulse is generated at a predetermined percentage of the period of the repetitive waveform without regard to frequency. Counts are accumulated in two counters, the first counting during the "on" fraction of the period, and the second counting during the "off" fraction. The counts accumulated during each cycle are compared. On equality the trigger pulse is generated. Count input rates to each counter are determined by the ratio of the on-off fractions of the event waveform and the desired phase relationship. This invention is of particular utility in providing a trigger or synchronizing pulse during the open period of the shutter of a high-speed framing camera during its acceleration as well as its period of substantially constant speed.

DeVolpi, Alexander (Lisle, IL); Pecina, Ronald J. (Westchester, IL); Travis, Dale J. (Lockport, IL)

1976-01-01T23:59:59.000Z

366

Hydrogen atom in crossed electric and magnetic fields: Phase space topology and torus quantization via periodic orbits  

E-Print Network (OSTI)

A hierarchical ordering is demonstrated for the periodic orbits in a strongly coupled multidimensional Hamiltonian system, namely the hydrogen atom in crossed electric and magnetic fields. It mirrors the hierarchy of broken resonant tori and thereby allows one to characterize the periodic orbits by a set of winding numbers. With this knowledge, we construct the action variables as functions of the frequency ratios and carry out a semiclassical torus quantization. The semiclassical energy levels thus obtained agree well with exact quantum calculations.

Stephan Gekle; Jörg Main; Thomas Bartsch; T. Uzer

2006-10-02T23:59:59.000Z

367

A radio frequency coaxial feedthrough  

DOE Patents (OSTI)

An improved radio frequency coaxial transmission line vacuum feedthrough is provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflection from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits the voltage and power handling capabilities of a feedthrough.

Owens, T.L.

1987-12-07T23:59:59.000Z

368

Timed fast charger  

Science Conference Proceedings (OSTI)

In a charger for rechargeable electrochemical cells, a transformer charging circuit supplies a charging current to the battery at a fast charge rate for a predetermined time followed by a continuous slow charge rate. A normally closed automatic reset thermostat in series with the rectifier diodes in the charging circuit, and thermally coupled to them, opens after a period of time, dependent upon the heat generated by the rectifier diodes and upon the thermal mass of the thermostat and diodes, and terminates the fast charge current. A resistor, shunted across the thermostat and thermally coupled to it, establishes a slow charge rate current path when the thermostat opens. Heat generated in the resistor causes the thermostat to remain open as long as the battery is connected and ac power is supplied to the transformer primary winding.

Mullersman, F.H.

1981-10-27T23:59:59.000Z

369

Poland in the period 1992–2003  

E-Print Network (OSTI)

Reconstruction of the UV-time series weighted for the plant action spectrum based on the UV and total ozone data collected at Belsk,

Piotr Sobolewski

2005-01-01T23:59:59.000Z

370

QUASI-PERIODIC OSCILLATIONS AND BROADBAND VARIABILITY IN SHORT MAGNETAR BURSTS  

Science Conference Proceedings (OSTI)

The discovery of quasi-periodic oscillations (QPOs) in magnetar giant flares has opened up prospects for neutron star asteroseismology. However, with only three giant flares ever recorded, and only two with data of sufficient quality to search for QPOs, such analysis is seriously data limited. We set out a procedure for doing QPO searches in the far more numerous, short, less energetic magnetar bursts. The short, transient nature of these bursts requires the implementation of sophisticated statistical techniques to make reliable inferences. Using Bayesian statistics, we model the periodogram as a combination of red noise at low frequencies and white noise at high frequencies, which we show is a conservative approach to the problem. We use empirical models to make inferences about the potential signature of periodic and QPOs at these frequencies. We compare our method with previously used techniques and find that although it is on the whole more conservative, it is also more reliable in ruling out false positives. We illustrate our Bayesian method by applying it to a sample of 27 bursts from the magnetar SGR J0501+4516 observed by the Fermi Gamma-ray Burst Monitor, and we find no evidence for the presence of QPOs in any of the bursts in the unbinned spectra, but do find a candidate detection in the binned spectra of one burst. However, whether this signal is due to a genuine quasi-periodic process, or can be attributed to unmodeled effects in the noise is at this point a matter of interpretation.

Huppenkothen, Daniela; Watts, Anna L.; Uttley, Phil; Van der Horst, Alexander J.; Van der Klis, Michiel [Astronomical Institute ''Anton Pannekoek'', University of Amsterdam, Postbus 94249, 1090-GE Amsterdam (Netherlands); Kouveliotou, Chryssa [Office of Science and Technology, ZP12, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Goegues, Ersin [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul 34956 (Turkey); Granot, Jonathan [The Open University of Israel, 1 University Road, P.O. Box 808, Ra'anana 43537 (Israel); Vaughan, Simon [X-Ray and Observational Astronomy Group, University of Leicester, Leicester LE1 7RH (United Kingdom); Finger, Mark H., E-mail: D.Huppenkothen@uva.nl [Universities Space Research Association, Huntsville, AL 35805 (United States)

2013-05-01T23:59:59.000Z

371

Mode-coupling Cerenkov sum-frequency-generation in a multimode planar waveguide  

SciTech Connect

We present experimental and theoretical studies of the mode-coupling Cerenkov sum-frequency radiations in a multimode LiNbO{sub 3} planar waveguide. The radiations result from the coupling of different guided modes of the fundamental wave, which have the same optical frequencies but different propagation constants. At the same time, scattering-involved Cerenkov sum-frequency-generation was also observed and discussed. Our theoretical predictions are in well accordance with the experimental results.

Chen Changdong; Su Jie; Xu Ping; Hu Xiaopeng; Zhao Gang; Liu Yanhua; Lv Xinjie; Zhu Shining [Department of Physics, National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Zhang Yong [Department of Physics, National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); School of Modern Engineering and Applied Science, Nanjing University, Nanjing, 210093 (China)

2010-10-18T23:59:59.000Z

372

Periodic windows distribution resulting from homoclinic bifurcations in the two-parameter space  

E-Print Network (OSTI)

Periodic solution parameters, in chaotic dynamical systems, form periodic windows with characteristic distribution in two-parameter spaces. Recently, general properties of this organization have been reported, but a theoretical explanation for that remains unknown. Here, for the first time we associate the distribution of these periodic windows with scaling laws based in fundamental dynamic properties. For the R\\"ossler system, we present a new scenery of periodic windows composed by multiple spirals, continuously connected, converging to different points along of a homoclinic bifurcation set. We show that the bi-dimensional distribution of these periodic windows unexpectedly follows scales given by the one-parameter homoclinic theory. Our result is a strong evidence that, close to homoclinic bifurcations, periodic windows are aligned in the two-parameter space.

Rene Orlando Medrano-T.; Iberę Luis Caldas

2010-12-10T23:59:59.000Z

373

Time Brightness  

NLE Websites -- All DOE Office Websites (Extended Search)

Perlmutter, et al., in Thermonuclear Supernovae, NATO ASI, v. 486 (1997) Perlmutter, et al., in Thermonuclear Supernovae, NATO ASI, v. 486 (1997) Cosmology from . . . Time Brightness ... . . . 50-100 Fields Lunar Calendar Scheduled Follow-Up Imaging at Hubble, Cerro Tololo, WIYN, Isaac Newton Scheduled Follow-Up Spectroscopy at Keck Almost 1000 Galaxies per Field RESULT: ~24 Type Ia supernovae discovered while still brightening, at new moon Berkeley Lab Keck WIYN Cerro Tololo Isaac Newton Hubble Strategy We developed a strategy to guarantee a group of supernova discoveries on a certain date. Just after a new moon, we observe some 50 to 100 high-galactic lattitute fields-each containing almost a thousand high-redshift galaxies-in two nights on the Cerro Tololo 4-meter telescope with Tyson & Bernstein's wide-field camera. We return three weeks later to observe the same

374

Watching an uniformly moving source of light using a telescope and a frequency-meter  

E-Print Network (OSTI)

We propose a scenario that involves a stationary observer who detects a point like source of light moving with constant velocity at a constant altitude, using a telescope and a frequency-meter. We derive a formula for the angular velocity at which we should rotate the axis of the telescope and a formula that relates the proper period at which the source emits successive wave crests and the proper period at which the stationary observer receives them

Bernhard Rothenstein; Ioan Damian

2005-04-04T23:59:59.000Z

375

WIDE BAND REGENERATIVE FREQUENCY DIVIDER AND MULTIPLIER  

DOE Patents (OSTI)

A regenerative frequency divider and multiplier having wide band input characteristics is presented. The circuit produces output oscillations having frequencies related by a fixed ratio to input oscillations over a wide band of frequencies. In accomplishing this end, the divider-multiplier includes a wide band input circuit coupled by mixer means to a wide band output circuit having a pass band related by a fixed ratio to that of the input circuit. A regenerative feedback circuit derives a fixed frequency ratio feedback signal from the output circuit and applies same to the mixer means in proper phase relation to sustain fixed frequency ratio oscillations in the output circuit.

Laine, E.F.

1959-11-17T23:59:59.000Z

376

Hybrid genetic algorithm for multi-time period production/distribution planning  

Science Conference Proceedings (OSTI)

In this paper, we deal with a production/distribution problem to determine an efficient integration of production, distribution and inventory system so that products are produced and distributed at the right quantities, to the right customers, and at ... Keywords: Genetic algorithms, Logistics, Optimization, Prüfer number, Production/distribution problem

Mitsuo Gen; Admi Syarif

2005-06-01T23:59:59.000Z

377

Extracting unstable periodic orbits from chaotic time series data Paul So,1,2  

E-Print Network (OSTI)

, D.C. 20010 2 Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 3

Roberts, Stephen

378

The Real-Time Ultrafinescale Forecast Support during the Special Observing Period of the MAP  

Science Conference Proceedings (OSTI)

Recent developments in numerical modeling and computer technology will soon allow for limited-areaproduction-type numerical weather prediction at a resolution of 1-2 km. This advance opens exciting prospects for the prediction of airflow and ...

R. Benoit; C. Schär; P. Binder; S. Chamberland; H. C. Davies; M. Desgagné; C. Girard; C. Keil; N. Kouwen; D. Lüthi; D. Maric; E. Müller; P. Pellerin; J. Schmidli; F. Schubiger; C. Schwierz; M. Sprenger; A. Walser; S. Willemse; W. Yu; E. Zala

2002-01-01T23:59:59.000Z

379

Macroscopic quantum behaviour of periodic quantum systems  

E-Print Network (OSTI)

In this paper we introduce a simple procedure for computing the macroscopic quantum behaviour of periodic quantum systems in the high energy regime. The macroscopic quantum coherence is ascribed to a one-particle state, not to a condensate of a many-particle system; and we are referring to a system of high energy but with few degrees of freedom. We show that, in the first order of approximation, the quantum probability distributions converge to its classical counterparts in a clear fashion, and that the interference effects are strongly suppressed. The harmonic oscillator provides a testing ground for these ideas and yields excellent results.

A. Martín-Ruiz; J. Bernal; Adrián Carbajal-Domínguez

2013-09-02T23:59:59.000Z

380

Correlated magnetic reversal in periodic stripe patterns  

Science Conference Proceedings (OSTI)

The magnetization reversal in a periodic magnetic stripe array has been studied with a combination of direct and reciprocal space methods: Kerr microscopy and polarized neutron scattering. Kerr images show that during magnetization reversal over a considerable magnetic-field range a ripple domain state occurs in the stripes with magnetization components perpendicular to the stripes. Quantitative analysis of polarized neutron specular reflection, Bragg diffraction, and off-specular diffuse scattering provides a detailed picture of the mean magnetization direction in the ripple domains as well as longitudinal and transverse fluctuations, and reveals a strong correlation of those components over a number of stripes.

Theis-Broehl, Katharina; Toperverg, Boris P.; Leiner, Vincent; Westphalen, Andreas; Zabel, Hartmut; McCord, Jeffrey; Rott, Karsten; Brueckl, Hubert [Department of Physics, Ruhr-University Bochum, 44780 Bochum (Germany); Leibniz Institute for Solid State and Materials Research Dresden, Institute for Metallic Materials, Helmholtzstr. 20, D-01169 Dresden (Germany); Department of Physics, University Bielefeld, Universitaetsstr. 25, 33615 Bielefeld (Germany)

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Multiple fundamental frequency estimation and polyphony inference of polyphonic music signals  

Science Conference Proceedings (OSTI)

This paper presents a frame-based system for estimating multiple fundamental frequencies (F0s) of polyphonic music signals based on the short-time Fourier transform (STFT) representation. To estimate the number of sources along with their F0s, it is ... Keywords: automatic music transcription, frequency estimation, music information retrieval, noise estimation, signal analysis, source separation

Chunghsin Yeh; Axel Roebel; Xavier Rodet

2010-08-01T23:59:59.000Z

382

On the numerical simulation of Kerr frequency combs using coupled mode equations  

E-Print Network (OSTI)

It is demonstrated that Kerr frequency comb generation described by coupled mode equations can be numerically simulated using Fast Fourier Transform methods. This allows broadband frequency combs spanning a full octave to be efficiently simulated using standard algorithms, resulting in orders of magnitude improvements in the computation time.

Hansson, T; Wabnitz, S

2013-01-01T23:59:59.000Z

383

MR LLRF VXI upgrade beam study period  

Science Conference Proceedings (OSTI)

AD/RFI/LLRF group personnel performed several studies with the MR LLRF VXI upgrade system during the evening of 7/29/95. The study period lasted about 4 hours. The MR operating conditions were a mixture of $29 and $2B cycles, with beam injected only on the $29. The author believes the $2B cycles were present for reasons unrelated to the study. The basic study period goal was to test the initial VXI version of MR LLRF finite state machine (FSM) execution. This goal represents what has been called MR LLRF VXI Upgrade Implementation Stage No.2 throughout presentations and documentation on the upgrade project. The test includes control of MR LLRF NIM hardware, the MR RF cavities, and beam via XVI TTL FSM outputs. Numerous MR LLRF VXI system objects, or components, must work together correctly for a successful test. Very briefly, the required objects include VXI Front End hardware, the ACNET/Front End interface code, and the VXI/NIM Interface chassis (the chassis solves VXI-CAMAC-NIM RF and FSM output connectivity and development problems). Though this initial FSM does not yet fully support Upgrade Implementation Stage 2 functionality, all code and hardware for the following basic functionality is tested.

Mesiner, K.; /Fermilab

1995-01-01T23:59:59.000Z

384

Jordan cells of periodic loop models  

E-Print Network (OSTI)

Jordan cells in transfer matrices of finite lattice models are a signature of the logarithmic character of the conformal field theories that appear in their thermodynamical limit. The transfer matrix of periodic loop models, T_N, is an element of the periodic Temperley-Lieb algebra EPTL_N(\\beta, \\alpha), where N is the number of sites on a section of the cylinder, and \\beta = -(q+1/q) = 2 \\cos \\lambda and \\alpha the weights of contractible and non-contractible loops. The thermodynamic limit of T_N is believed to describe a conformal field theory of central charge c=1-6\\lambda^2/(\\pi(\\lambda-\\pi)). The abstract element T_N acts naturally on (a sum of) spaces V_N^d, similar to those upon which the standard modules of the (classical) Temperley-Lieb algebra act. These spaces known as sectors are labeled by the numbers of defects d and depend on a {\\em twist parameter} v that keeps track of the winding of defects around the cylinder. Criteria are given for non-trivial Jordan cells of T_N both between sectors with distinct defect numbers and within a given sector.

Alexi Morin-Duchesne; Yvan Saint-Aubin

2013-02-22T23:59:59.000Z

385

Integrally formed radio frequency quadrupole  

DOE Patents (OSTI)

An improved radio frequency quadrupole (10) is provided having an elongate housing (11) with an elongate central axis (12) and top, bottom and two side walls (13a-d) symmetrically disposed about the axis, and vanes (14a-d) formed integrally with the walls (13a-d), the vanes (14a-d) each having a cross-section at right angles to the central axis (12) which tapers inwardly toward the axis to form electrode tips (15a-d) spaced from each other by predetermined distances. Each of the four walls (13a-d), and the vanes (14a-d) integral therewith, is a separate structural element having a central lengthwise plane (16) passing through the tip of the vane, the walls (13a-d) having flat mounting surfaces (17, 18) at right angles to and parallel to the control plane (16), respectively, which are butted together to position the walls and vane tips relative to each other.

Abbott, Steven R. (Concord, CA)

1989-01-01T23:59:59.000Z

386

Department of Energy Announces Plans for Additional Comment Period...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Announces Plans for Additional Comment Period on National Interest Electric Transmission Corridors Department of Energy Announces Plans for Additional Comment Period on National...

387

EA-1566: Notice of Comment Period Extension | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

EA-1566: Notice of Comment Period Extension Proposed Infrastructure Improvements for the Yucca Mountain Project, Nevada DOE is extending the public comment period for the Yucca...

388

DOE Extends Public Comment Period for Uranium Program Environmental...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Other Agencies You are here Home DOE Extends Public Comment Period for Uranium Program Environmental Impact Statement DOE Extends Public Comment Period for Uranium...

389

EIS-0403: Notice to Extend Public Comment Period | Department...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Notice to Extend Public Comment Period EIS-0403: Notice to Extend Public Comment Period Solar Energy Development in Six Southwestern States The Department of Energy and the Bureau...

390

Periodicity, Thermal Effects, and Vacuum Force: Rotation in Random Classical Zero-Point Radiation  

E-Print Network (OSTI)

We show that, for a detector rotating in a random classical zero-point electromagnetic or massless scalar field at zero temperature, thermal effects exist. The rotating reference system is constructed as an infinite set of Frenet-Seret tetrads so that the detector is at rest in a tetrad at each proper time. Frequency spectrum of correlation functions contains the Planck thermal factor with temperature $T_{rot} = \\frac{\\hbar \\Omega}{2 \\pi k_B} $. The energy density the rotating detector observes is proportional to the sum of energy densities of Planck's spectrum at the temperature $T_{rot}$ and zero-point radiation. The proportionality factor is $2/3 (4 \\gamma^2 -1)$ for an EMF and $2/9 (4 \\gamma^2 -1)$ for a MSF, where $\\gamma = (1 - (\\frac{\\Omega r}{c})^2)^{-1/2}$, and r is a rotation radius. The origin of these thermal effects is the periodicity of the correlation functions and their discrete spectrum, both following rotation with angular velocity $\\Omega$. The thermal energy can also be interpreted as a source of a vacuum force (VF) applied to the rotating detector from the vacuum field. The VF depends on the size of neither the charge nor the mass, like the force in the Casimir model for a charged particle, but, contrary to the last one, VF is attractive and directed to the center of the circular orbit. VF infinitely grows in magnitude with orbit radius. The orbits with a radius greater than $c/ \\Omega$ do not exist because the returning VF becomes infinite. On the uttermost orbit with the radius $c / \\Omega$, a linear velocity of the rotating particle would have become c. The VF becomes very small and proportional to radius when r is very small. Such VF dependence on radius, at large and small radii, can be associated respectively with so called confinement and asymptotic freedom, known in quantum chromodynamics, and provide a new explanation for them.

Yefim Semenovitch Levin

2010-03-23T23:59:59.000Z

391

Quality of monitoring of stochastic events by periodic & proportional-share scheduling of sensor coverage  

Science Conference Proceedings (OSTI)

We analyze the quality of monitoring (QoM) of stochastic events by a periodic sensor which monitors a point of interest (PoI) for q time every p time. We show how the amount of information captured at a PoI is affected by the proportion ...

David K. Y. Yau; Nung Kwan Yip; Chris Y. T. Ma; Nageswara S. Rao; Mallikarjun Shankar

2008-12-01T23:59:59.000Z

392

Mo Year Report Period: EIA ID NUMBER:  

U.S. Energy Information Administration (EIA) Indexed Site

Version No: 2013.01 Mo Year Report Period: EIA ID NUMBER: http://www.eia.gov/survey/form/eia_14/instructions.pdf Mailing Address: Secure File Transfer option available at: (e.g., PO Box, RR) https://signon.eia.doe.gov/upload/noticeoog.jsp Electronic Transmission: The PC Electronic Zip Code - Data Reporting Option (PEDRO) is available. If interested in software, call (202) 586-9659. Email form to: OOG.SURVEYS@eia.doe.gov - - - - Fax form to: (202) 586-9772 Mail form to: Oil & Gas Survey Email address: U.S. Department of Energy Ben Franklin Station PO Box 279 Washington, DC 20044-0279 Questions? Call toll free: 1-800-638-8812 PADD 4 Type of Report (Check One ): (Thousands of dollars) (Thousands of barrels) PADD 2 PADD 3 PAD DISTRICT (a) Revision to Report:

393

Frequency modulation drive for a piezoelectric motor  

DOE Patents (OSTI)

A piezoelectric motor has peak performance at a specific frequency f.sub.1 that may vary over a range of frequencies. A drive system is disclosed for operating such a motor at peak performance without feedback. The drive system consists of the motor and an ac source connected to power the motor, the ac source repeatedly generating a frequency over a range from f.sub.1 -.DELTA.x to f.sub.1 +.DELTA.y.

Mittas, Anthony (Albuquerque, NM)

2001-01-01T23:59:59.000Z

394

Techniques for high-performance digital frequency synthesis and phase control  

E-Print Network (OSTI)

This thesis presents a 3.6-GHz, 500-kHz bandwidth digital [delta][sigma] frequency synthesizer architecture that leverages a recently invented noise-shaping time-to-digital converter (TDC) and an all-digital quantization ...

Hsu, Chun-Ming, Ph. D. Massachusetts Institute of Technology

2008-01-01T23:59:59.000Z

395

Hurricane Surface Wind Measurements from an Operational Stepped Frequency Microwave Radiometer  

Science Conference Proceedings (OSTI)

For the first time, the NOAA/Aircraft Operations Center (AOC) flew stepped frequency microwave radiometers (SFMRs) on both WP-3D research aircraft for operational hurricane surface wind speed measurement in 2005. An unprecedented number of major ...

Eric W. Uhlhorn; Peter G. Black; James L. Franklin; Mark Goodberlet; James Carswell; Alan S. Goldstein

2007-09-01T23:59:59.000Z

396

Barotropic Dynamics of Interactions between Synoptic and Low-Frequency Eddies  

Science Conference Proceedings (OSTI)

The interaction of low-frequency and synoptic eddies is studied by diagnosing the time-averaged transport of vorticity by linear, transient eddies propagating on a basic state that includes a stationary wave. An analytic calculation assuming a ...

Jianchun Qin; Walter A. Robinson

1992-01-01T23:59:59.000Z

397

Nonlinear optical response from periodic molecular structures  

Science Conference Proceedings (OSTI)

The explicit expressions of all independent components of the molecular crystal nonlinear susceptibility (NS) tensor (of any order) are given through the independent components of hyperpolarizability (HP) tensors of the constituting molecules. This expression ... Keywords: Hartree-Fock time-dependent approach, Hyperpolarizability, Lorentz tensor, Madelung potential, nonlinear susceptibility, reaction field theory

M. Mestechkin

2008-04-01T23:59:59.000Z

398

Non-adiabatically changing the frequency of light in a transient microcavity  

E-Print Network (OSTI)

We study frequency-resolved femtosecond pump-probe reflectivity of a planar GaAs/AlAs microcavity. About 8 ps after a pump pulse, we observe an excess signal due to a non-adiabatic frequency change of the stored light by more than 4 linewidths away from the cavity resonance. Strikingly, the frequency change of light occurs at a time when the pump pulse is long gone. The frequency change is caused by the accumulated phase change of the light stored in the transient cavity. In agreement with an analytical model, the excess reflectivity is high when the cavity resonance frequency strongly shifts compared to the cavity linewidth within one cavity storage time.

Harding, Philip J; Hartsuiker, Alex; Claudon, Julien; Mosk, Allard P; Gerard, Jean-Michel; Vos, Willem L

2009-01-01T23:59:59.000Z

399

Resonant circuit which provides dual frequency excitation for rapid cycling of an electromagnet  

DOE Patents (OSTI)

Disclosed is a ring magnet control circuit that permits synchrotron repetition rates much higher than the frequency of the cosinusoidal guide field of the ring magnet during particle acceleration. the control circuit generates cosinusoidal excitation currents of different frequencies in the half waves. During radio frequency acceleration of the particles in the synchrotron, the control circuit operates with a lower frequency cosine wave and thereafter the electromagnets are reset with a higher frequency half cosine wave. Flat-bottom and flat-top wave shaping circuits maintain the magnetic guide field in a relatively time-invariant mode during times when the particles are being injected into the ring magnets and when the particles are being ejected from the ring magnets.

Praeg, Walter F. (Palos Park, IL)

1984-01-01T23:59:59.000Z

400

EIS-0380: Notice to Extend Comment Period on the Draft Site-Wide  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

to Extend Comment Period on the Draft Site-Wide to Extend Comment Period on the Draft Site-Wide Environmental Impact Statement EIS-0380: Notice to Extend Comment Period on the Draft Site-Wide Environmental Impact Statement Continued Operation of Los Alamos National Laboratory, Los Alamos, New Mexico In response to requests for additional time to review and comment on the document, NNSA is extending the public comment period until September 20, 2006. DOE/EIS-0380, Department of Energy, National Nuclear Security Administration, Extension of Comment Period on the Draft Site-Wide Environmental Impact Statement for Continued Operation of Los Alamos National Laboratory, Los Alamos, New Mexico, 76 FR 40352 (August 2006) More Documents & Publications EIS-0380: DOE Notice of Availability of the Draft Site-Wide Environmental

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Two-Phase Reaction Turbine. Technical progress report for the period July-December 1999  

DOE Green Energy (OSTI)

During the initial part of this period the concentrated effort was placed on getting comprehensive analysis and design of the turbine prototype. This was in order to be able to initiate its fabrication as needed for its building, assembling and timely testing. In the second part of this period the effort was placed on design and other considerations needed to acquire the test rig within the limited budget based on subsequent grant from the DOE.

NONE

1999-12-31T23:59:59.000Z

402

Performance Period Total Fee Paid FY2001  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

01 01 $4,547,400 FY2002 $4,871,000 FY2003 $6,177,902 FY2004 $8,743,007 FY2005 $13,134,189 FY2006 $7,489,704 FY2007 $9,090,924 FY2008 $10,045,072 FY2009 $12,504,247 FY2010 $17,590,414 FY2011 $17,558,710 FY2012 $14,528,770 Cumulative Fee Paid $126,281,339 Cost Plus Award Fee DE-AC29-01AL66444 Washington TRU Solutions LLC Contractor: Contract Number: Contract Type: $8,743,007 Contract Period: $1,813,482,000 Fee Information Maximum Fee $131,691,744 Total Estimated Contract Cost: $4,547,400 $4,871,000 $6,177,902 October 2000 - September 2012 Minimum Fee $0 Fee Available EM Contractor Fee Site: Carlsbad Field Office - Carlsbad, NM Contract Name: Waste Isolation Pilot Plant Operations March 2013 $13,196,690 $9,262,042 $10,064,940 $14,828,770 $12,348,558 $12,204,247 $17,590,414 $17,856,774

403

RIEGER-TYPE PERIODICITY IN THE OCCURRENCE OF SOLAR TYPE III RADIO BURSTS  

Science Conference Proceedings (OSTI)

This Letter presents the first observations of a Rieger-type periodicity with the period of 156{sub -9}{sup +19} days in the occurrence rate of solar coronal type III radio bursts. The periodicity was detected during the time interval from 2000 June 22 to 2003 December 31. This interval partially contains the maximum and the declining phase of solar cycle 23. The radio spectra were provided by the Learmonth Solar Radio Observatory in Western Australia, part of the USAF Radio Solar Telescope Network.

Lobzin, V. V.; Cairns, Iver H.; Robinson, P. A. [School of Physics, University of Sydney, NSW 2006 (Australia)

2012-08-01T23:59:59.000Z

404

Do Periodicities in Extinction -- with Possible Astronomical Connections -- Survive a Revision of the Geological Timescale?  

E-Print Network (OSTI)

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 at 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.

Melott, Adrian L

2013-01-01T23:59:59.000Z

405

Definition: Frequency Response | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Frequency Response Jump to: navigation, search Dictionary.png Frequency Response (Equipment) The ability of a system or elements of the system to react or respond to a change in system frequency. (System) The sum of the change in demand, plus the change in generation, divided by the change in frequency, expressed in megawatts per 0.1 Hertz (MW/0.1 Hz).[1] View on Wikipedia Wikipedia Definition Related Terms system, smart grid References ↑ Glossary of Terms Used in Reliability Standards An i LikeLike UnlikeLike You like this.Sign Up to see what your friends like. nline Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Frequency_Response&oldid=502580"

406

Multi-dimensional ultra-high frequency passive radio frequency identification tag antenna designs  

E-Print Network (OSTI)

In this thesis, we present the design, simulation, and empirical evaluation of two novel multi-dimensional ultra-high frequency (UHF) passive radio frequency identification (RFID) tag antennas, the Albano-Dipole antenna ...

Delichatsios, Stefanie Alkistis

2006-01-01T23:59:59.000Z

407

Planck Early Results: The Low Frequency Instrument data processing  

E-Print Network (OSTI)

We describe the data processing pipeline employed by the Low Frequency Instrument (LFI) Data Processing Centre (DPC) to create and characterize the frequency maps used by the ERCSC (Early Release Compact Source Catalogue) first product of Planck to become public. In particular, we discuss the various steps involved in reducing the data, starting from telemetry (TM)packets through to the production of cleaned calibrated timelines and calibrated frequency maps. Data are continuously calibrated using the modulation induced on the mean temperature of the Cosmic Microwave Background Radiation by the proper motion of the spacecraft. The sky signals other than the dipole are removed by an iterative procedure based on simultaneous fitting of calibration parameters and sky maps. Noise properties are estimated from time-ordered data where the sky signal is removed using a Generalized Least Square map-making algorithm. The measured 1/f noise knee-frequencies range from \\sim 100 mHz at 30 GHz to a few tens of mHz at 70 G...

Zacchei, A; Baccigalupi, C; Bersanelli, M; Bonaldi, A; Bonavera, L; Burigana, C; Butler, R C; Cuttaia, F; de Zotti, G; Dick, J; Frailis, M; Galeotta, S; González-Nuevo, J; Górski, K M; Gregorio, A; Keihänen, E; Keskitalo, R; Knoche, J; Kurki-Suonio, H; Lawrence, C R; Leach, S; Leahy, J P; López-Caniego, M; Mandolesi, N; Maris, M; Matthai, F; Meinhold, P R; Mennella, A; Morgante, G; Morisset, N; Natoli, P; Pasian, F; Perrotta, F; Polenta, G; Poutanen, T; Reinecke, M; Ricciardi, S; Rohlfs, R; Sandri, M; Suur-Uski, A -S; Tauber, J A; Tavagnacco, D; Terenzi, L; Tomasi, M; Valiviita, J; Villa, F; Zonca, A; Banday, A J; Barreiro, R B; Bartlett, J G; Bartolo, N; Bedini, L; Bennett, K; Binko, P; Borrill, J; Bouchet, F R; Bremer, M; Cabella, P; Cappellini, B; Chen, X; Colombo, L; Cruz, M; Curto, A; Danese, L; Davies, R D; Davis, R J; de Gasperis, G; de Rosa, A; de Troia, G; Dickinson, C; Diego, J M; Donzelli, S; Dörl, U; Efstathiou, G; En\\sslin, T A; Eriksen, H K; Falvella, M C; Finelli, F; Franceschi, E; Gaier, T C; Gasparo, F; Génova-Santos, R T; Giardino, G; Gómez, F; Gruppuso, A; Hansen, F K; Hell, R; Herranz, D; Hovest, W; Jewell, J; Juvela, M; Kisner, T S; Knox, L; Lähteenmäki, A; Lamarre, J -M; Leonardi, R; León-Tavares, J; Lilje, P B; Lubin, P M; Maggio, G; Marinucci, D; Martínez-González, E; Massardi, M; Matarrese, S; Meharga, M T; Melchiorri, A; Migliaccio, M; Mitra, S; Moss, A; N\\orgaard-Nielsen, H U; Pagano, L; Paladini, R; Paoletti, D; Partridge, B; Pearson, D; Pettorino, V; Pietrobon, D; Prézeau, G; Procopio, P; Puget, J -L; Quercellini, C; Rachen, J P; Rebolo, R; Robbers, G; Rocha, G; Rubi\; Salerno, E; Savelainen, M; Scott, D; Seiffert, M D; Silk, J I; Smoot, G F; Sternberg, J; Stivoli, F; Stompor, R; Tofani, G; Tuovinen, J; Türler, M; Umana, G; Vielva, P; Vittorio, N; Vuerli, C; Wade, L A; Watson, R; White, S D M; Wilkinson, A

2011-01-01T23:59:59.000Z

408

The Ocean Response to Low-Frequency Interannual Atmospheric Variability in the Mediterranean Sea. Part I: Sensitivity Experiments and Energy Analysis  

Science Conference Proceedings (OSTI)

In this study a general circulation model is used in order to investigate the interannual response of the Mediterranean Basin to low-frequency interannual variability in atmospheric forcing for the period 1980–88. The model incorporates a ...

G. Korres; N. Pinardi; A. Lascaratos

2000-02-01T23:59:59.000Z

409

Digital slip frequency generator and method for determining the desired slip frequency  

DOE Patents (OSTI)

The output frequency of an electric power generator is kept constant with variable rotor speed by automatic adjustment of the excitation slip frequency. The invention features a digital slip frequency generator which provides sine and cosine waveforms from a look-up table, which are combined with real and reactive power output of the power generator.

Klein, Frederick F. (Monroeville, PA)

1989-01-01T23:59:59.000Z

410

Ultra-stable long distance optical frequency distribution using the Internet fiber network  

E-Print Network (OSTI)

We report an optical link of 540 km for ultrastable frequency distribution over the Internet fiber network. The stable frequency optical signal is processed enabling uninterrupted propagation on both directions. The robustness and the performance of the link are enhanced by a cost effective fully automated optoelectronic station. This device is able to coherently regenerate the return optical signal with a heterodyne optical phase locking of a low noise laser diode. Moreover the incoming signal polarization variation are tracked and processed in order to maintain beat note amplitudes within the operation range. Stable fibered optical interferometer enables optical detection of the link round trip phase signal. The phase-noise compensated link shows a fractional frequency instability in 10 Hz bandwidth of 5\\times10-15 at one second measurement time and 2\\times10-19 at 30 000 s. This work is a significant step towards a sustainable wide area ultrastable optical frequency distribution and comparison network.

Lopez, Olivier; Chanteau, Bruno; Chardonnet, Christian; Amy-Klein, Anne; Santarelli, Georgio

2012-01-01T23:59:59.000Z

411

A method of electric field flow fractionation wherein the polarity of the electric field is periodically reversed  

DOE Patents (OSTI)

Field flow fractionation, a method obtaining high resolution separations of organic and inorganic colloids and soluble molecules, has been known in the art for approximately twenty years. The term field flow fractionation uses the word field in a generic sense. The field may comprise an electric field, a temperature gradient, a pH gradient, gravitational sedimentation or sedimentation through the application of a centrifugal force. The field is made to act upon a flowing solution or colloidal suspension and causes segregation or fractionation of the solute molecules or colloid particles. A novel method of electric field flow fractionation for separating solute molecules from a carrier solution is disclosed. The method of the invention utilizes an electric field that is periodically reversed in polarity, in a time-dependent, wave-like manner. The parameters of the waveform, including amplitude, frequency and wave shape may be varied to optimize separation of solute species. The waveform may further include discontinuities to enhance separation. 11 figs.

Stevens, F.J.

1990-03-15T23:59:59.000Z

412

An Alternate Graphical Representation of Periodic table of Chemical Elements  

E-Print Network (OSTI)

Periodic table of chemical elements symbolizes an elegant graphical representation of symmetry at atomic level and provides an overview on arrangement of electrons. It started merely as tabular representation of chemical elements, later got strengthened with quantum mechanical description of atomic structure and recent studies have revealed that periodic table can be formulated using SO(4,2)* SU(2) group. IUPAC, the governing body in Chemistry, doesn't approve any periodic table as a standard periodic table. The only specific recommendation provided by IUPAC is that the periodic table should follow the 1 to 18 group numbering. In this technical paper, we describe a new graphical representation of periodic table, referred as 'Circular form of Periodic table'. The advantages of circular form of periodic table over other representations are discussed along with a brief discussion on history of periodic tables.

Mohd Abubakr

2009-10-01T23:59:59.000Z

413

Turbine bucket natural frequency tuning rib  

SciTech Connect

A tuning rib is added preferably in the aft cavity of a cored turbine bucket to alter the bucket's natural frequencies. The tuning rib may be a solid rib or a segmented rib and is particularly suited for altering high order frequency modes such as 2T, 4F and 1-3S. As such, detrimental crossings of natural bucket frequencies and gas turbine stimuli can be avoided to thereby improve the reliability of a gas turbine without impacting other features of the bucket that are important to the performance of the gas turbine.

Wang, John Zhiqiang (Greenville, SC); Norton, Paul Francis (Greenville, SC); Barb, Kevin Joseph (Halfmoon, NY); Jacala, Ariel Caesar-Prepena (Simpsonville, SC)

2002-01-01T23:59:59.000Z

414

High power radio frequency attenuation device  

DOE Patents (OSTI)

A resistor device for attenuating radio frequency power includes a radio frequency conductor connected to a series of fins formed of high relative magnetic permeability material. The fins are dimensional to accommodate the skin depth of the current conduction therethrough, as well as an inner heat conducting portion where current does not travel. Thermal connections for air or water cooling are provided for the inner heat conducting portions of each fin. Also disclosed is a resistor device to selectively alternate unwanted radio frequency energy in a resonant cavity.

Kerns, Quentin A. (Bloomingdale, IL); Miller, Harold W. (Winfield, IL)

1984-01-01T23:59:59.000Z

415

Time-specific measurements of energy deposition from radiation fields in simulated sub-micron tissue volumes  

Science Conference Proceedings (OSTI)

A tissue-equivalent spherical proportional counter is used with a modified amplifier system to measure specific energy deposited from a uniform radiation field for short periods of time ({approximately}1 {micro}s to seconds) in order to extrapolate to dose in sub-micron tissue volumes. The energy deposited during these time intervals is compared to biological repair processes occurring within the same intervals after the initial energy deposition. The signal is integrated over a variable collection time which is adjusted with a square-wave pulse. Charge from particle passages is collected on the anode during the period in which the integrator is triggered, and the signal decays quickly to zero after the integrator feedback switch resets; the process repeats for every triggering pulse. Measurements of energy deposited from x rays, {sup 137}Cs gamma rays, and electrons from a {sup 90}Sr/{sup 90}Y source for various time intervals are taken. Spectral characteristics as a function of charge collection time are observed and frequency plots of specific energy and collection time-interval are presented. In addition, a threshold energy flux is selected for each radiation type at which the formation of radicals (based on current measurements) in mammalian cells equals the rate at which radicals are repaired.

Famiano, M.A.

1997-07-07T23:59:59.000Z

416

Variable speed constant frequency constant voltage alternator. Annual report  

DOE Green Energy (OSTI)

A test alternator is operated with digital control of its output frequency for variable shaft speed. The machine is a two-pole alternator with power removed through slip rings. The output frequency of the alternator is controlled by rotating the field by stepping through sixteen coils around the rotor. Usually four coils are active at one time. The rotating field in the stationary coils of the stator is controlled by microcircuits. The control circuits are constructed with available low-cost, low-power integrated circuits (ICs). The test results from the first test alternator indicate the feasibility of using this type of alternator to convert available wind power directly to usable 60 hertz power.

Grannemann, W.W.; Yang, C.E.; Seo, P.H.

1980-07-01T23:59:59.000Z

417

Transmission of a quantum state in a periodically poled nonlinear crystal  

E-Print Network (OSTI)

Theoretical calculations on transmission of quantum states such as Schr\\"{o}dinger cat (SC) states are considered in a periodically poled nonlinear crystal (PPNC). Combinations of various initial states (SC, coherent (C),and vacuum (V)) of light waves at frequencies $\\omega_{e}$ and $3\\omega_{e}$ at the input of a PPNC are studied. It is shown that the transmission and interference between superposition of macroscopically distinguishable states can be achieved by using a PPNC. Visualization and analyzes of transmission and interference processes are demonstrated with the help of reduced Wigner quasi-probability distribution functions of considered light waves.

Ranjit Singh

2010-05-03T23:59:59.000Z

418

THz laser based on quasi-periodic AlGaAs superlattices  

SciTech Connect

The use of quasi-periodic AlGaAs superlattices as an active element of a quantum cascade laser of terahertz range is proposed and theoretically investigated. A multi-colour emission, having from three to six peaks of optical gain, is found in Fibonacci, Thue-Morse, and figurate superlattices in electric fields of intensity F = 11 - 13 kV cm{sup -1} in the frequency range f = 2 - 4 THz. The peaks depend linearly on the electric field, retain the height of 20 cm{sup -1}, and strongly depend on the thickness of the AlGaAs-layers. (lasers)

Malyshev, K V [N.E. Bauman Moscow State Technical University, Moscow (Russian Federation)

2013-06-30T23:59:59.000Z

419

Frequency Regulation Basics and Trends  

DOE Green Energy (OSTI)

The electric power system must address two unique requirements: the need to maintain a near real-time balance between generation and load, and the need to adjust generation (or load) to manage power flows through individual transmission facilities. These requirements are not new: vertically integrated utilities have been meeting them for a century as a normal part of conducting business. With restructuring, however, the services needed to meet these requirements, now called ''ancillary services'', are being more clearly defined. Ancillary services are those functions performed by the equipment and people that generate, control, and transmit electricity in support of the basic services of generating capacity, energy supply, and power delivery. The Federal Energy Regulatory Commission (FERC) has defined such services as those ''necessary to support the transmission of electric power from seller to purchaser given the obligations of control areas and transmitting utilities within those control areas to maintain reliable operations of the interconnected transmission system''. This statement recognizes the importance of ancillary services for both bulk-power reliability and support of commercial transactions. Balancing generation and load instantaneously and continuously is difficult because loads and generators are constantly fluctuating. Minute-to-minute load variability results from the random turning on and off of millions of individual loads. Longer-term variability results from predictable factors such as the daily and seasonal load patterns as well as more random events like shifting weather patterns. Generators also introduce unexpected fluctuations because they do not follow their generation schedules exactly and they trip unexpectedly due to a range of equipment failures. The output from wind generators varies with the wind. Storage technologies should be ideal suppliers of several ancillary services, including regulation, contingency reserves (spinning reserve, supplemental reserve, replacement reserve), and voltage support. These services are not free; in regions with energy markets, generators are paid to supply these services. In vertically integrated utilities (without energy markets) the utility incurs significant costs to supply these services. Supplying these services may be a significant business opportunity for emerging storage technologies. This report briefly explores the various ancillary services that may be of interest to storage. It then focuses on regulation, the most expensive ancillary service. It also examines the impact that increasing amounts of wind generation may have on regulation requirements, decreasing conventional regulation supplies, and the implications for energy storage.

Kirby, BJ

2005-05-06T23:59:59.000Z

420

Scheduling and resource binding algorithm considering timing variation  

Science Conference Proceedings (OSTI)

The timing closure problem (e.g., meeting timing/ clock period constraint) is one of the most important problems in the design automation. However, the rapid increase of the impact of the process variation on circuit timing makes the problem much more ... Keywords: binding, high-level synthesis, scheduling, timing analysis, timing variation

Jongyoon Jung; Taewhan Kim

2011-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Markedness and frequency: a computational analysis  

Science Conference Proceedings (OSTI)

When the markedness analysis is extended to the lexical and grammatical levels, the question arises whether an analogue of the markedness/frequency correlation, observed in phonology, also exists on these higher linguistic levels. This article presents ...

Henry Ku?era

1982-07-01T23:59:59.000Z

422

Very-High-Frequency Resonant Boost Converters  

E-Print Network (OSTI)

This paper presents a resonant boost topology suitable for very-high-frequency (VHF, 30-300 MHz) DC-DC power conversion. The proposed design features low device voltage stress, high efficiency over a wide load range, and ...

Perreault, David J.

423

Radio frequency dc-dc power conversion  

E-Print Network (OSTI)

THIS THESIS addresses the development of system architectures and circuit topologies for dc-dc power conversion at very high frequencies. The systems architectures that are developed are structured to overcome limitations ...

Rivas, Juan, 1976-

2007-01-01T23:59:59.000Z

424

Propagation of Rossby Waves of Nonzero Frequency  

Science Conference Proceedings (OSTI)

The propagation of Rossby waves of positive and negative frequency, corresponding to eastward and westward phase speeds, respectively, is investigated. The techniques used are theoretical analysis, ray tracing, and initial value problems in ...

Gui-Ying Yang; Brian J. Hoskins

1996-08-01T23:59:59.000Z

425

Security approaches for Radio Frequency Identification systems  

E-Print Network (OSTI)

In this thesis, I explore the challenges related to the security of the Electronic Product Code (EPC) class of Radio Frequency Identification (RFID) tags and associated data. RFID systems can be used to improve supply chain ...

Foley, Joseph Timothy, 1976-

2007-01-01T23:59:59.000Z

426

Radio Frequency Identification : regulating information privacy protection  

E-Print Network (OSTI)

As applications of Radio Frequency Identification (RFID) become more profuse, the technology itself is stirring up some controversy. Due to its potential for amassing large amounts of information about both people and ...

Laufer, Deanna (Deanna Raquel)

2007-01-01T23:59:59.000Z

427

Definition: Frequency Bias | Open Energy Information  

Open Energy Info (EERE)

Authority Area, Balancing Authority, frequency error, smart grid References Glossary of Terms Used in Reliability Standards An inl LikeLike UnlikeLike You like this.Sign...

428

Definition: Frequency Error | Open Energy Information  

Open Energy Info (EERE)

difference between the actual and scheduled frequency. (FA - FS)1 References Glossary of Terms Used in Reliability Standards An LikeLike UnlikeLike You like this.Sign Up...

429

Frequency Discrimination of Random?Amplitude Tones  

Science Conference Proceedings (OSTI)

The ability of human observers to discriminate frequencies of tones between 1000 and 15 000 cps was measured in a temporal 2?alternative forced?choice discriminationexperiment. On each trial

G. Bruce Henning

1965-01-01T23:59:59.000Z

430

The Frequency Distribution of Thunderstorm Durations  

Science Conference Proceedings (OSTI)

The frequency distributions of thunderstorm durations were analyzed for 30 years at 36 stations in the United States in order to develop an appropriate summarizing statistic for durations. The incomplete gamma function provides a close fit to the ...

P. J. Robinson; D. R. Easterling

1988-01-01T23:59:59.000Z

431

EIS-0403: Public Comment Period Extension | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

403: Public Comment Period Extension 403: Public Comment Period Extension EIS-0403: Public Comment Period Extension Solar Energy Development in Six Southwestern States The Bureau of Land Management (BLM) announced a two-week extension of the public comment period for the Draft Solar Programmatic Environmental Impact Statement (Draft Solar PEIS), a joint effort with the Department of Energy. The agencies had previously provided for a 120-day public comment period on the Draft Solar PEIS. Because of numerous requests, the agencies extended the comment period by an additional two weeks beyond April 16, 2011. The comment period ran (with extension) until May 2, 2011. EIS-0403-DEIS_Second_Comment_Extension-2011.pdf More Documents & Publications EIS-0403: Notice to Extend Public Comment Period

432

Femtosecond second-harmonic generation in periodically poled lithium niobate  

E-Print Network (OSTI)

Femtosecond second-harmonic generation in periodically poled lithium niobate waveguides poled lithium niobate waveguides under large conversion conditions. Strong saturation of the SHG detailed experi- mental data on femtosecond SHG in periodically poled lithium niobate (PPLN) waveguides

Purdue University

433

PARS II Process Document - DOE Period Close | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

DOE Period Close PARS II Process Document - DOE Period Close This document details the process adopted by the Office of Acquisition and Project Management to prepare APM DepSec...

434

Microsoft Word - PARS II Process Document - Close Period 2013...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

PARS II APM DepSec Monthly Report & Close Period, V-2013-04-29 Page 1 PARS II Process Document APM DEPSEC MONTHLY REPORT & CLOSE PERIOD PURPOSE The purpose of this document is to...

435

Development of Radio Frequency Exposure Standards  

Science Conference Proceedings (OSTI)

While unconfirmed claims of adverse human health effects from electromagnetic radiation date to the 1930s, development of modern safety standards did not begin until the 1952 Hirsch study of eye damage at a microwave power density of 100 mW/cm2. Early work on standards focused on microwave frequencies due to rapid development of radar and microwave communications links. In the years since 1952, radio frequency (RF) exposure standards have kept pace with those technological advancements. While refinements...

2004-11-01T23:59:59.000Z

436

Overview of Personal Radio Frequency Communication Technologies  

Science Conference Proceedings (OSTI)

The growth of wireless electronic communication devices and their applications is creating an increasingly complex radio frequency (RF) environment in the workplace and home. Personal communication applications discussed in this report include cordless telephones, analog cellular telephones, digital cellular telephones, and a dozen more. Depending on the specific wireless device, different frequency ranges, modulation types, multiple access types, and power levels can be encountered. The significant grow...

2008-09-09T23:59:59.000Z

437

Methods for measuring search engine performance over time  

Science Conference Proceedings (OSTI)

This study introduces methods for evaluating search engine performance over a time period. Several measures are defined, which as a whole describe search engine functionality over time. The necessary setup for such studies is described, and the use of ...

Judit Bar-Ilan

2002-02-01T23:59:59.000Z

438

Periodic Materials and Interference Lithography for Photonics ... - TMS  

Science Conference Proceedings (OSTI)

02/28/2011 - Periodic Materials and Interference Lithography for Photonics, ... photonic crystals (electromagnetic wave propagation) and phononic crystals ...

439

On periodic wave functions of Schrödinger operators on Cayley trees  

E-Print Network (OSTI)

In the paper we define periodic wave functions for a (discrete) Schr\\"odinger operator on a Cayley tree. This periodicity depends on a subgroup of a group representation of the Cayley tree. For any subgroup of finite index we give a criterion for eigenvalues of the Schr\\"odinger operator under which there are periodic wave functions. For a normal subgroup of infinite index we describe a class of periodic wave functions.

Fumio Hiroshima; Utkir Rozikov

2013-04-11T23:59:59.000Z

440

Extremely high frequency RF effects on electronics.  

SciTech Connect

The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

A new measurement technique for tracking voltage phasors, local system frequency, and rate of change of frequency  

Science Conference Proceedings (OSTI)

With the advent of Substation Computer Systems dedicated to protection, control and data logging functions in a Substation, it becomes possible to develop new applications which can utilize the processing power available within the substation. The microcomputer based Symmetrical Component Distance Relay (SCDR) described in the references cited at the end of this paper possesses certain characteristics which facilitate real-time monitoring of positive sequence voltage phasor at the local power system bus. With a regression analysis the frequency and rate-of-change of frequency at the bus can also be determined from the positive sequence voltage phase angle. This paper describes the theoretical basis of these computations and describes results of experiments performed in the AEP power system simulation laboratory. Plans for future field tests on the AEP system are also outlined.

Phadke, A.G.; Adamiak, M.G.; Thorp, J.S.

1983-05-01T23:59:59.000Z

442

Low-frequency plasma conductivity in the average-atom approximation  

E-Print Network (OSTI)

Low-frequency properties of a plasma are examined within the average-atom approximation, which presumes that scattering of a conducting electron on each atom takes place independently of other atoms. The relaxation time tau distinguishes a high-frequency region omega tau > 1, where the single-atom approximation is applicable explicitly, from extreme low frequencies omega tau 1, reproducing the Ziman formula in the static limit, results based on the Kubo-Greenwood formula for high frequencies, and satisfying the conductivity sum-rule precisely. The correspondence between physical processes leading to the conventional Ohm's law and the infrared properties of QED is discussed. The suggested average-atom approach to frequency-dependent conductivity is illustrated by numerical calculations for the an aluminum plasma in the temperature range 2--10 eV.

Kuchiev, M Yu

2008-01-01T23:59:59.000Z

443

Exact Evaluation of Batch-Ordering Inventory Policies in Two-Echelon Supply Chains with Periodic Review  

Science Conference Proceedings (OSTI)

This paper studies a two-echelon supply chain with stochastic and discrete consumer demand, batch order quantities, periodic inventory review, and deterministic transportation times. Reorder point policies manage inventories at every location. Average ... Keywords: Inventory/production: multi-echelon, Periodic review heuristic., Stochastic demand

Gérard P. Cachon

2001-01-01T23:59:59.000Z

444

Analysis of time response of lossy multiconductor transmission line networks  

E-Print Network (OSTI)

Abstract —Systems are considered consisting of an arbitrary number of multiconductor transmission lines joined and terminated by arbitrary linear networks. The fines are assumed to be Iossy, with frequency-dependent parameters. The system is analyzed in the frequency domain, and the inverse Fourier transform is used to obtain tbe time-domain response.

Antonije R. Djordjevic; Tapan; K. Sarkar; Senior Member

1987-01-01T23:59:59.000Z

445

New periodic variable stars coincident with ROSAT sources discovered using SuperWASP  

E-Print Network (OSTI)

We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables. A further 30 of these objects are previously known pre-main sequence stars, for which we detect a modulation period for the first time. Amongst the newly identified periodic variables, many appear to be close eclipsing binaries, their X-ray emission is presumably the result of RS CVn type behaviour. Others are probably BY Dra stars, pre-main sequence stars and other rapid rotators displaying enhanced coronal activity. A number of previously catalogued pulsating variables (RR Lyr stars and Cepheids) coincident with X-ray sources are also seen, but we show that these are likely to be misclassifications. We identify four objects which are probable low mass eclipsing binary stars, based on their very red colour and light curve morphology.

A. J. Norton; P. J. Wheatley; R. G. West; C. A. Haswell; R. A. Street; A. Collier Cameron; D. J. Christian; B. Enoch; M. Gallaway; C. Hellier; K. Horne; J. Irwin; S. R. Kane; T. A. Lister; J. P. Nicholas; N. Parley; D. Pollacco; R. Ryans; I. Skillen; D. M. Wilson

2007-02-23T23:59:59.000Z

446

New periodic variable stars coincident with ROSAT sources discovered using SuperWASP  

E-Print Network (OSTI)

We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables. A further 30 of these objects are previously known pre-main sequence stars, for which we detect a modulation period for the first time. Amongst the newly identified periodic variables, many appear to be close eclipsing binaries, their X-ray emission is presumably the result of RS CVn type behaviour. Others are probably BY Dra stars, pre-main sequence stars and other rapid rotators displaying enhanced coronal activity. A number of previously catalogued pulsating variables (RR Lyr stars and Cepheids) coincident with X-ray sources are also seen, but we show that these are likely to be misclassifications. We identify four objects which are probable low mass eclipsing binary stars, based on their very red colour and light curve morphology.

Norton, A J; West, R G; Haswell, C A; Street, R A; Cameron, A C; Christian, D J; Enoch, B; Gallaway, M; Hellier, C; Horne, K; Irwin, J; Kane, S R; Lister, T A; Nicholas, J P; Parley, N; Pollacco, D; Ryans, R; Skillen, I; Wilson, D M

2007-01-01T23:59:59.000Z

447

A Method of Estimating Space-Time Spectra from Polar-Orbiting Satellite Data  

Science Conference Proceedings (OSTI)

Space-time spectral formulas are modified to estimate wavenumber-frequency spectra correctly from space-time series data sampled at the same local time but at different hours of a day by a polar-orbiting satellite.

Yoshikazu Hayashi

1980-06-01T23:59:59.000Z

448

On the Spectral Integration of the Quasi-Geostrophic Equations for Doubly-Periodic and Channel Flow  

Science Conference Proceedings (OSTI)

The spectral integration of the quasi-geostrophic equations is reexamined for simple boundary conditions in Cartesian geometry. For doubly-periodic flow, it is shown that the mean shear must be constant in time or its evolution specified; grid ...

Geoffrey K. Vallis

1985-01-01T23:59:59.000Z

449

Parabolic equation modeling of high frequency acoustic transmission with an evolving sea surface  

E-Print Network (OSTI)

Parabolic equation modeling of high frequency acoustic transmission with an evolving sea surface J is combined with a rough surface formulation of a parabolic equation model for predicting time an approximation of the time-varying acoustic field. The wide-angle parabolic equation model manages the rough sea

Archer, Cristina Lozej

450

NATIONAL EVALUATION OF THE WEATHERIZATION ASSISTANCE PROGRAM DURING THE ARRA PERIOD: PROGRAM YEARS 2009-2011  

SciTech Connect

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.

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

451

ISM band to U-NII band frequency transverter and method of frequency transversion  

DOE Patents (OSTI)

A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

2006-09-12T23:59:59.000Z

452

ISM band to U-NII band frequency transverter and method of frequency transversion  

DOE Patents (OSTI)

A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz-6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

2006-04-04T23:59:59.000Z

453

Short period eclipsing binary candidates identified using SuperWASP  

E-Print Network (OSTI)

We present light curves and periods of 53 candidates for short period eclipsing binary stars identified by SuperWASP. These include 48 newly identified objects with periods <2x10^4 seconds (~0.23d), as well as the shortest period binary known with main sequence components (GSC2314-0530 = 1SWASP J022050.85+332047.6) and four other previously known W UMa stars (although the previously reported periods for two of these four are shown to be incorrect). The period distribution of main sequence contact binaries shows a sharp cut-off at a lower limit of around 0.22d, but until now, very few systems were known close to this limit. These new candidates will therefore be important for understanding the evolution of low mass stars and to allow investigation of the cause of the period cut-off.

Norton, A J; Evans, T; West, R G; Wheatley, P J; Anderson, D R; Barros, S C C; Butters, O W; Cameron, A Collier; Christian, D J; Enoch, B; Faedi, F; Haswell, C A; Hellier, C; Holmes, S; Horne, K D; Lister, T A; Maxted, P F L; Parley, N; Pollacco, D; Simpson, E K; Skillen, I; Smalley, B; Southworth, J; Street, R A

2011-01-01T23:59:59.000Z

454

Kilohertz quasi-periodic oscillations and strong field gravity in X-ray binaries  

E-Print Network (OSTI)

In the past five years observations with the Rossi X-ray Timing Explorer have revealed fast quasi-periodic oscillations in the X-ray flux of about 20 X-ray binaries. Thought to originate close to the surface of a neutron star, these oscillations provide unique information about the strong gravitational field in which they are produced.

Mariano Mendez

2002-07-12T23:59:59.000Z

455

Spectrum of geomagnetic activity in the period range 560 days: possible lunar inuences  

E-Print Network (OSTI)

Spectrum of geomagnetic activity in the period range 5±60 days: possible lunar in¯uences J. StrÏ es (if any) is not mediated by geomag- netic activity. Key words. Geomagnetism and paleomagnetism á Time Introduction Geomagnetic activity displays various regular and irregular variations. These have been

Paris-Sud XI, Université de

456

"Stokes' Second Problem in High Frequency Limit. Application to Micro (Nano)- Resonators  

E-Print Network (OSTI)

Using kinetic equation in the relaxation approximation (RTA), we investigate a flow generated by an infinite plate oscillating with frequency $\\omega$. Geometrical simplicity of the problem allows a solution in the entire range of dimensionless frequency variation $0\\leq \\omega \\tau\\leq \\infty$, where $\\tau$ is a properly defined relaxation time. A transition from viscoelastic behavior of Newtonian fluid ($\\omega\\tau\\to 0$) to purely elastic dynamics in the limit $\\omega\\tau\\to \\infty$ is discovered. The relation of the derived solutions to microfluidics (high-frequency micro-resonators) is demonstrated on an example of a "plane oscillator .

V. Yakhot; C. Colosqui

2006-09-25T23:59:59.000Z

457

Frequency response analysis of fluid control systems for parabolic-trough solar collectors  

DOE Green Energy (OSTI)

A linearized steady-state frequency response is derived for parabolic-trough collectors and for connecting piping that can be used in standard gain-phase analyses to evaluate system stability and closed-loop frequency response. The frequency-response characteristics of a typical collector string and piping are used in a gain-phase analysis to get some insight into the effect on system stability of various system parameters such as controller gain, sensor and controller-time constants, and sensor location.

Schindwolf, R.

1981-07-01T23:59:59.000Z

458

Time and Space Variability of Tropical Pacific Wind Stress  

Science Conference Proceedings (OSTI)

The results of a spectral analysis of a new, subjectively analyzed data set of tropical Pacific wind stress are presented. The monthly data for the 10-year period, 1961–70, allow a detailed inspection of the distributions of frequency and zonal ...

Stanley B. Goldenberg; James J. O'Brien

1981-06-01T23:59:59.000Z

459

Low-level convergence and its role in convective intensity and frequency over the Houston lightning and rainfall anomaly  

E-Print Network (OSTI)

An increase in the amount of lightning and rainfall over the Houston area, compared to the surrounding rural areas, has been well documented in previous studies. The placement of a Shared Mobile Atmospheric Research and Teaching Radar (SMART-R) in the Houston area during the summer season of 2005 presented a unique opportunity to investigate the role of boundary-layer convergence in modulating convective frequency and intensity and, thereby, likely causing the rainfall and lightning anomalies. The role of the urban heat island (UHI) and the sea-breeze, as a source of low-level convergence leading to enhanced convection over Houston, was examined. Hourly average dual-Doppler wind and convergence maps were created on 1 X 1 km grids for an eleven-week period. By using these images along with average lightning, rainfall, and reflectivity for a large Houston-centered domain, it was possible to discern a correlation between low-level convergence and convection. Also, past findings of enhancement in lightning and rainfall over Houston and downwind of Houston were validated. High convergence levels for the Houston area in the mid-morning were followed closely by a peak in convection in the early afternoon. The enhancement of rainfall and lightning over and downwind of downtown was found to be primarily from a large increase in frequency of deep convective events when compared to the surrounding domain. Also, it was found that UHI, rather than sea-breeze, was likely the primary causative mechanism in the development of convection over the Houston area because of the lack of deep convection in areas equally affected by the sea-breeze and the timing of the convection compared to time of peak sea-breeze. An area of weaker enhancement south of Houston, not discussed in previous studies, was found to be present, possibly from the interactions between the bay-breeze off of the Galveston Bay and the seabreeze.

McNear, Veronica Ann

2003-05-01T23:59:59.000Z

460

Importance of Low-Frequency Contributions to Eddy Fluxes Observed over Rough Surfaces  

Science Conference Proceedings (OSTI)

Eddy covariance flux observations at a deciduous temperate forest site (83 days) and at a boreal forest site (21 days) are analyzed for midday periods (1100–1400 LT). Approximate stationarity of the time series is demonstrated, and the ensemble-...

Ricardo K. Sakai; David R. Fitzjarrald; Kathleen E. Moore

2001-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Low-Frequency Current Observations in the Korea/Tsushima Strait  

Science Conference Proceedings (OSTI)

High resolution, continuous current measurements made in the Korea/Tsushima Strait between May 1999 and March 2000 are used to examine current variations having time periods longer than 2 days. Twelve bottom-mounted acoustic Doppler current ...

W. J. Teague; G. A. Jacobs; H. T. Perkins; J. W. Book; K-I. Chang; M-S. Suk

2002-06-01T23:59:59.000Z

462

High frequency inductive lamp and power oscillator  

DOE Patents (OSTI)

A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and I or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to adjust the driving frequency of the oscillator.

MacLennan, Donald A. (Gaithersburg, MD); Dymond, Jr., Lauren E. (North Potomac, MD); Gitsevich, Aleksandr (Montgomery Village, MD); Grimm, William G. (Silver Spring, MD); Kipling, Kent (Gaithersburg, MD); Kirkpatrick, Douglas A. (Great Falls, VA); Ola, Samuel A. (Silver Spring, MD); Simpson, James E. (Gaithersburg, MD); Trimble, William C. (Columbia, MD); Tsai, Peter (Olney, MD); Turner, Brian P. (Damascus, MD)

2001-01-01T23:59:59.000Z

463

High frequency inductive lamp and power oscillator  

DOE Patents (OSTI)

A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

MacLennan, Donald A. (Gaithersburg, MD); Turner, Brian P. (Damascus, MD); Dolan, James T. (Frederick, MD); Kirkpatrick, Douglas A. (Great Falls, VA); Leng, Yongzhang (Damascus, MD)

2000-01-01T23:59:59.000Z

464

Periodicity, Thermal Effects, and Vacuum Force: Rotation in Random Classical Zero-Point Radiation  

E-Print Network (OSTI)

We show that for a detector rotating in a random classical zero-point electromagnetic or massless scalar field at T=0 thermal effects exist. The rotating reference system is constructed as an infinite set of Frenet-Seret tetrads defined so that the detector is at rest in a tetrad at each proper time. Correlation functions, more exactly their frequency spectrum, contain the Planck thermal factor, and the energy density the rotating detector observes is proportional to the sum of energy densities of Planck's spectrum at the temperature T_rot = \\hbar \\Omega / (2 \\pi k_B) and zero-point radiation. The proportionality factor is (2/3)(4\\gamma^2 - 1) for an electromagnetic field and (2/9)(4\\gamma^2 - 1) for a massless scalar field, where \\gamma = (1 - (\\Omega r/c)^2)^(-1/2), and r is a detector rotation radius. The origin of these thermal effects is the periodicity of the correlation functions and their discrete spectrum, both following rotation with angular velocity \\Omega. The thermal energy can also be interpreted as a source of a vacuum force, f_vac, applied to the rotating detector from the vacuum field. The f_vac depends on the size of neither the charge nor the mass, like the force in the Casimir model for a charged particle, but, contrary to the last one, it is directed to the center of the circular orbit. The f_vac infinitely grows by magnitude when r \\to r_0 = c/\\Omega, with a fixed \\Omega. The orbits with a radius greater than r_0 do not exist simply because the returning vacuum force becomes infinite. On the uttermost orbit with the radius r_0, a linear velocity of the rotating particle would have become c. The f_vac becomes very small and proportional to r when r is small, r << c/\\aOmega. Such vacuum force dependence on radius, at large and small r, can be associated respectively with so called confinement and asymptotic freedom, known in QCD, and provide a new explanation for them.

Yefim Semenovitch Levin

2010-03-22T23:59:59.000Z

465

Extending quantum control of time-independent systems to time-dependent systems  

E-Print Network (OSTI)

We establish that if a scheme can control a time-independent system arbitrarily coupled to a generic finite bath over a short period of time $T$ with control precision $O(T^{N+1})$, it can also realize the control with the same order of precision on smoothly time-dependent systems. This result extends the validity of various universal dynamical control schemes to arbitrary analytically time-dependent systems.

Zhen-Yu Wang; Ren-Bao Liu

2011-01-27T23:59:59.000Z

466

Frequency Instability Problems in North American Interconnections  

NLE Websites -- All DOE Office Websites (Extended Search)

Frequency Instability Problems in Frequency Instability Problems in North American Interconnections May 1, 2011 DOE/NETL-2011/1473 Frequency Instability Problems in North American Interconnections Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement,

467

Frequency Scanned Interferometry for ILC Tracker Alignment  

E-Print Network (OSTI)

In this paper, we report high-precision absolute distance and vibration measurements performed with frequency scanned interferometry. Absolute distance was determined by counting the interference fringes produced while scanning the laser frequency. High-finesse Fabry-Perot interferometers were used to determine frequency changes during scanning. A dual-laser scanning technique was used to cancel drift errors to improve the absolute distance measurement precision. A new dual-channel FSI demonstration system is also presented which is an interim stage toward practical application of multi-channel distance measurement. Under realistic conditions, a precision of 0.3 microns was achieved for an absolute distance of 0.57 meters. A possible optical alignment system for a silicon tracker is also presented.

Hai-Jun Yang; Tianxiang Chen; Keith Riles

2011-09-12T23:59:59.000Z

468

Time-Resolved  

NLE Websites -- All DOE Office Websites (Extended Search)

(the vibrational period for atomic motion is about 100 femtoseconds). This "ultrafast" regime opens the possibility of exploring the making and breaking of chemical bonds...

469

NIST Internet time service  

Science Conference Proceedings (OSTI)

... Most operating systems (ie Windows, Mac, Linux) have an option to automatically synchronize the system clock periodically using an NTP (network ...

2013-02-22T23:59:59.000Z

470

RF Cherenkov picosecond timing technique for high energy physics applications  

Science Conference Proceedings (OSTI)

The Cherenkov time-of-propagation (TOP) detector and Cherenkov time-of-flight (TOF) detector in a ?head-on? geometry based on the recently proposed time measuring technique with radio frequency (RF) phototube are considered. Results of the Monte Carlo simulations are presented.

Margaryan, Amur; Hashimoto, Osamu; Majewski, Stanislaw; Tang, Liguang

2008-09-01T23:59:59.000Z

471

Light-driven liquid crystalline nonlinear oscillator under optical periodic forcing  

E-Print Network (OSTI)

An all-optically driven strategy to govern a liquid crystalline collective molecular nonlinear oscillator is discussed. It does not require external feedbacks of any kind while the oscillator and a time-depending perturbation both are sustained by incident light. Various dynamical regimes such as frequency -locked, quasiperiodic, forced and chaotic are observed in agreement with a theoretical approach developed in the limit of the plane wave approximation.

Dmitry O. Krimer; Etienne Brasselet

2007-07-15T23:59:59.000Z

472

Shock driven jamming and periodic fracture of particulate rafts  

E-Print Network (OSTI)

A tenuous monolayer of hydrophobic particles at the air-water interface often forms a scum or raft. When such a monolayer is disturbed by the localized introduction of a surfactant droplet, a radially divergent surfactant shock front emanates from the surfactant origin and packs the particles into a jammed, compact, annular band with a packing fraction that saturates at a peak packing fraction $\\phi^*$. As the resulting two-dimensional, disordered elastic band grows with time and is driven radially outwards by the surfactant, it fractures to form periodic triangular cracks with robust geometrical features. We find the number of cracks $N$ and the compaction band radius $R^*$ at fracture onset vary monotonically with the initial packing fraction ($\\phi_{init}$). However, its width $W^*$ is constant for all $\\phi_{init}$. A simple geometric theory that treats the compaction band as an elastic annulus, and accounts for mass conservation allows us to deduce that $N \\simeq 2\\pi R^*/W^* \\simeq 4\\pi \\phi_{RCP}/\\phi_{init}$, a result we verify both experimentally and numerically. We show the essential ingredients for this phenomenon are an initially low enough particulate packing fraction that allows surfactant driven advection to cause passive jamming and eventual fracture of the hydrophobic particulate interface.

M. M. Bandi; T. Tallinen; L. Mahadevan

2010-10-29T23:59:59.000Z

473

Attenuating Plant Noise: Active Noise Control Helmholtz Resonator Demonstration: Low Frequency Noise Mitigation  

Science Conference Proceedings (OSTI)

This report describes the implementation of the active Helmholtz resonator concept at a Midwestern power plant to suppress low frequency noise emitted from three simple-cycle, combustion turbine peaking units. The units normally operate during the summer season and only when electricity demand is very high (e.g., during periods with high ambient temperatures). However, when one or more of the units are dispatched, the plant sometimes receives complaints from the residential development located approximat...

2004-03-23T23:59:59.000Z

474

Nonlinearities in Low-Frequency Equatorial Waves  

Science Conference Proceedings (OSTI)

The nonlinear response to low-latitude, temporally periodic forcing centered on the equator is studied. Comparisons are made with a linear solution containing no advections; for both solutions the model consists of a spectral, equatorial ?-plane ...

Andrew H. Van Tuyl

1987-09-01T23:59:59.000Z

475

Seismic isolation systems with distinct multiple frequencies  

DOE Patents (OSTI)

A method and apparatus for isolating a building or other structure from smic vibratory motion which provides increased assurance that large horizontal motion of the structure will not occur than is provided by other isolation systems. Increased assurance that large horizontal motion will not occur is achieved by providing for change of the natural frequency of the support and structure system in response to displacement of the structure beyond a predetermined value. The natural frequency of the support and structure system may be achieved by providing for engaging and disengaging of the structure and some supporting members in response to motion of the supported structure.

Wu, Ting-shu (Downers Grove, IL); Seidensticker, Ralph W. (Wheaton, IL)

1990-01-01T23:59:59.000Z

476

Seismic isolation systems with distinct multiple frequencies  

DOE Patents (OSTI)

The present invention relates generally to a method and apparatus for supporting a structure such as a building, bridge, or power plant such that it is isolated from seismic vibratory ground motion. More particularly, the present invention relates to a method and apparatus for supporting a structure by an isolation system which will not allow large dynamic loads to be transmitted to the supported structure due to seismic motions which have damaging energy at frequencies at or near the natural frequency of the structure and the overall structural systems. 4 figs.

Wu, Ting-shu; Seidensticker, R.W.

1989-04-14T23:59:59.000Z

477

Changes in risk perception over time  

SciTech Connect

The focus of this paper is on changes in perceptions of the risks associated with nuclear waste management over time. In particular, we are interested in the kinds of change that take place when the management programs, and those who are charged with implementing them, are subject to intensive public debate over an extended period of time. We are undertaken an over-time study of perceived risks in Colorado and New Mexico by implementing sequential random household surveys in each state, timed at six month intervals. This study employs three of these surveys, spanning the period from summer, 1990 to summer, 1991. Using these data, we examine the dynamics that may underlie variations in perceived risks over time. In particular, our analysis is focused on changes in the roles played by (1) basic political orientations (i.e. political ideology) and (2) trust in those who advocate conflicting policy positions.

Gomez, L.S. [Sandia National Labs., Albuquerque, NM (United States); Jenkins-Smith, H.C.; Miller, K.W. [New Mexico Univ., Albuquerque, NM (United States)

1992-01-01T23:59:59.000Z

478

EIS-0463: Extension of Scoping Period | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Extension of Scoping Period Extension of Scoping Period EIS-0463: Extension of Scoping Period Presidential Permit Application for Northern Pass Transmission, New Hampshire The U.S. Department of Energy (DOE) is reopening the public scoping period for the Northern Pass Transmission Line Project Environmental Impact Statement (EIS) (DOE/EIS-0463). In anticipation of additional alternative route information being provided by Northern Pass, DOE is reopening the scoping period. DOE will determine the close of the scoping period once the additional routing information is received from Northern Pass, and DOE will provide at least 45 days for public review and scoping comments on any such routing information. EIS-0463-ScopingExtension-2011.pdf More Documents & Publications Application for presidential permit OE Docket No. PP-371 Northern Pass

479

EIS-0463: Reopening of Scoping Period for the Environmental Impact  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reopening of Scoping Period for the Environmental Impact Reopening of Scoping Period for the Environmental Impact Statement EIS-0463: Reopening of Scoping Period for the Environmental Impact Statement Northern Pass Transmission Line Project The U.S. Department of Energy (DOE) is reopening the public scoping period for the Northern Pass Transmission Line Project Environmental Impact Statement (EIS) (DOE/EIS-0463). The scoping period now ends on June 14, 2011. Reopening of Scoping Period for the Northern Pass Transmission Line Project Environmental Impact Statement, EIS-0463 (April 2011) (76 FR 21338) More Documents & Publications EIS-0385: EPA Notice of Availability of the Final Environmental Impact Statement EIS-0425: EPA Notice of Availability of Draft Environmental Impact Statement EIS-0448: Notice of Adoption of an Environmental Impact Statement

480

EIS-0463: Reopening of Scoping Period for the Environmental Impact  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

463: Reopening of Scoping Period for the Environmental Impact 463: Reopening of Scoping Period for the Environmental Impact Statement EIS-0463: Reopening of Scoping Period for the Environmental Impact Statement Northern Pass Transmission Line Project The U.S. Department of Energy (DOE) is reopening the public scoping period for the Northern Pass Transmission Line Project Environmental Impact Statement (EIS) (DOE/EIS-0463). The scoping period now ends on June 14, 2011. Reopening of Scoping Period for the Northern Pass Transmission Line Project Environmental Impact Statement, EIS-0463 (April 2011) (76 FR 21338) More Documents & Publications EIS-0385: EPA Notice of Availability of the Final Environmental Impact Statement EIS-0408: DOE Notice of Availability of a Programmatic Draft Environmental Impact Statement EIS-0469: Notice of Intent To Prepare an Environmental Impact Statement and

Note: This page contains sample records for the topic "frequency time period" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Development and testing of artificial low?frequency speech codes  

Science Conference Proceedings (OSTI)

Previous work on frequency lowered speech for listeners whose hearing is confined to low frequencies has focused on signal processing of natural speech. In the present research

C. M. Reed; M. H. Power; K. K. Foss; N. I. Durlach; L. D. Braids

1987-01-01T23:59:59.000Z

482

Electricity demand as frequency controlled reserves, ENS (Smart...  

Open Energy Info (EERE)

Electricity demand as frequency controlled reserves, ENS (Smart Grid Project) Jump to: navigation, search Project Name Electricity demand as frequency controlled reserves, ENS...

483

DOE Extends Public Comment Period for the Draft Uranium Leasing...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Other Agencies You are here Home DOE Extends Public Comment Period for the Draft Uranium Leasing Program Programmatic Environmental Impact Statement DOE Extends Public...

484

Uranium Leasing Program Draft PEIS Public Comment Period Extended...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Centers Field Sites Power Marketing Administration Other Agencies You are here Home Uranium Leasing Program Draft PEIS Public Comment Period Extended to May 31, 2013 Uranium...

485

Green's function analysis of periodic structures in computational electromagnetics  

E-Print Network (OSTI)

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.

Van Orden, Derek

2011-01-01T23:59:59.000Z

486

EIS-0369: Notice of Public Comment Period Extension and Additional...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Comment Period Extension and Additional Public Meeting Supplemental Yucca Mountain Rail Corridor and Rail Alignment The Department of Energy is now announcing an additional...

487

EIS-0489: Notice of Comment Period Extension and Additional Scoping...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Meetings EIS-0489: Notice of Comment Period Extension and Additional Scoping Meetings Jordan Cove Liquefaction Project (Coos County, OR) and Pacific Connector Pipeline Project...

488

Multilevel interference lithography--fabricating sub-wavelength periodic nanostructures  

E-Print Network (OSTI)

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 ...

Chang, Chih-Hao, 1980-

2008-01-01T23:59:59.000Z

489

Greece in the Late Roman Period in its Mediterranean context.  

E-Print Network (OSTI)

??This thesis is on Greece in Late Antiquity. There is much attention for Roman Greece, but mostly, this attention goes to the periods of the… (more)

Kleef, Marloes van

2012-01-01T23:59:59.000Z

490

Blackbody radiation shift in 87Rb frequency standard  

E-Print Network (OSTI)

The operation of atomic clocks is generally carried out at room temperature, whereas the definition of the second refers to the clock transition in an atom at absolute zero. This implies that the clock transition frequency should be corrected in practice for the effect of finite temperature of which the leading contributor is the blackbody radiation (BBR) shift. Experimental measurements of the BBR shifts are difficult. In this work, we have calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in 87Rb using the relativistic all-order method and carried out detailed evaluation of the accuracy of our final value. Particular care is taken to accurately account for the contributions from highly-excited states. Our predicted value for the Stark coefficient, k_S=-1.240(4)\\times 10^{-10}\\text{Hz/(V/m)}^{2} is three times more accurate than the previous calculation [1].

M. S. Safronova; Dansha Jiang; U. I. Safronova

2010-07-03T23:59:59.000Z

491

Lagrangian Frequency Spectrum as a Diagnostic for Magnetohydrodynamic Turbulence Dynamics  

SciTech Connect

For the phenomenological description of magnetohydrodynamic turbulence competing models exist, e.g., Boldyrev [Phys. Rev. Lett. 96, 115002 (2006)] and Gogoberidze [Phys. Plasmas 14, 022304 (2007)], which predict the same Eulerian inertial-range scaling of the turbulent energy spectrum although they employ fundamentally different basic interaction mechanisms. A relation is found that links the Lagrangian frequency spectrum with the autocorrelation time scale of the turbulent fluctuations {tau}{sub ac} and the associated cascade time scale {tau}{sub cas}. Thus, the Lagrangian energy spectrum can serve to identify weak ({tau}{sub ac}<<{tau}{sub cas}) and strong ({tau}{sub ac{approx}{tau}cas}) interaction mechanisms providing insight into the turbulent energy cascade. The new approach is illustrated by results from direct numerical simulations of two- and three-dimensional incompressible MHD turbulence.

Busse, Angela; Mueller, Wolf-Christian; Gogoberidze, Grigol [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, 85748 Garching (Germany); Georgian National Astrophysical Observatory, 2a Kazbegi Avenue, 0160 Tbilisi (Georgia) and Centre for Plasma Astrophysics, University of Leuven, B-3001 Leuven (Belgium)