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We encourage you to perform a real-time search of NLEBeta
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1

Is there a maximum observable redshift in an open universe?  

E-Print Network [OSTI]

An estimate of the maximum observable redshift is obtained using only t_{0} approximately equal to (14+- 3)10^{9}years, H_{0} approximately equal to 65 +- 10Km\\sec^{-1}Mpc^{-1}(t_{0}H_{0} approximately equal to 0.91 +- 0.08/0.18) assuming \\Lambda approximately equal to 0. The resulting maximum redshift z_{+} approximately equal to 10 appears to give a reasonable upper limit to the highest actually observed redshifts. Some implications are discussed.

J. A. Gonzalo

2000-10-10T23:59:59.000Z

2

High-Energy Flare Observations from the Solar Maximum Mission  

Science Journals Connector (OSTI)

...research-article High-Energy Flare Observations from the Solar Maximum Mission W...Vestrand We review high-energy observations of solar flares with emphasis...expectation, high-energy emission is a common property of solar flares. Direct interpretation...

1991-01-01T23:59:59.000Z

3

HERSCHEL OBSERVATIONS OF CATACLYSMIC VARIABLES  

SciTech Connect (OSTI)

We have used the PACS instrument on the Herschel Space Observatory to observe eight cataclysmic variables at 70 and 160 {mu}m. Of these eight objects, only AM Her was detected. We have combined the Herschel results with ground-based, Spitzer, and WISE observations to construct spectral energy distributions for all of the targets. For the two dwarf novae in the sample, SS Cyg and U Gem, we find that their infrared luminosities are completely dominated by their secondary stars. For the two highly magnetic 'polars' in our survey, AM Her and EF Eri, we find that their mid-infrared excesses, previously attributed to circumbinary dust emission, can be fully explained by cyclotron emission. The WISE light curves for both sources show large, orbitally modulated variations that are identically phased to their near-IR light curves. We propose that significant emission from the lowest cyclotron harmonics (n {<=} 3) is present in EF Eri and AM Her. Previously, such emission would have been presumed to be optically thick, and not provide significant orbitally modulated flux. This suggests that the accretion onto polars is more complicated than assumed in the simple models developed for these two sources. We develop a model for the near-/mid-IR light curves for WZ Sge with an L2 donor star that shows that the ellipsoidal variations from its secondary star are detected. We conclude that none of the targets surveyed have dusty circumbinary disks.

Harrison, Thomas E.; Hamilton, Ryan T. [Department of Astronomy, New Mexico State University, Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Tappert, Claus [Departamento de Fisica y Astronomia, Universidad de Valparaiso, Avda. Gran Bretana 1111, Valparaiso (Chile); Hoffman, Douglas I. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Campbell, Ryan K., E-mail: tharriso@nmsu.edu, E-mail: rthamilt@nmsu.edu, E-mail: claus.tappert@uv.cl, E-mail: dhoffman@ipac.caltech.edu, E-mail: Ryan.Campbell@humobldt.edu [Department of Physics and Astronomy, Humboldt State University, 1 Harpst St., Arcata, CA 95521 (United States)

2013-01-01T23:59:59.000Z

4

Tropical climate variability from the last glacial maximum to the present  

E-Print Network [OSTI]

This thesis evaluates the nature and magnitude of tropical climate variability from the Last Glacial Maximum to the present. The temporal variability of two specific tropical climate phenomena is examined. The first is the ...

Dahl, Kristina Ariel

2005-01-01T23:59:59.000Z

5

Reducing Inconsistencies in Point Observations of Maximum Flood Inundation Level  

Science Journals Connector (OSTI)

Flood simulation models and hazard maps are only as good as the underlying data against which they are calibrated and tested. However, extreme flood events are by definition rare, so the observational data of flood inundation extent are limited in ...

Brandon L. Parkes; Hannah L. Cloke; Florian Pappenberger; Jeff Neal; David Demeritt

2013-08-01T23:59:59.000Z

6

Time Variability of the "Quiet" Sun Observed  

Science Journals Connector (OSTI)

The Transition Region and Coronal Explorer (TRACE) observed a "quiet-Sun" region on 1999 February 17 from 02:15 UT to 3:00 UT with full resolution (05 pixel size), high cadence (125 s), and deep exposures (65 and 46 s) in the 171 Ĺ and 195 Ĺ wavelengths. We start our investigation of the time variability of "quiet-Sun" images with a detailed analysis of instrumental and nonsolar effects, such as orbital temperature variations, filtering of particle radiation spikes, spacecraft pointing drift, and solar rotation tracking. We quantify the magnitude of various noise components (photon Poisson statistics, data digitization, data compression, and readout noise) and establish an upper limit for the data noise level, above which temporal variability can safely be attributed to solar origin. We develop a pattern recognition code that extracts spatiotemporal events with significant variability, yielding a total of 3131 events in 171 Ĺ and 904 events in 195 Ĺ. We classify all 904 events detected in 195 Ĺ according to flarelike characteristics and establish a numerical flare criterion based on temporal, spatial, and dynamic cross-correlation coefficients between the two observed temperatures (0.9 and 1.4 MK). This numerical criterion matches the visual flare classification in 83% of the cases and can be used for automated flare search. Using this flare discrimination criterion we find that only 35% (and 25%) of the events detected in 171 (and 195) Ĺ represent flarelike events. The discrimination of flare events leads to a frequency distribution of peak fluxes, N(?F) ? ?F-1.83±0.07 at 195 Ĺ, which is significantly flatter than the distribution of all events. A sensitive discrimination criterion of flare events is therefore important for microflare statistics and for conclusions on their occurrence rate and efficiency for coronal heating.

Markus J. Aschwanden; Richard W. Nightingale; Ted D. Tarbell; C. J. Wolfson

2000-01-01T23:59:59.000Z

7

8) Stratospheric equatorial variability a) Observations  

E-Print Network [OSTI]

speed. Phase lines inclined eastward when altitude increases indicating upward propation Signal field) Westward phase propagation but eastward group propagation Phase lines inclined westward Signal;5 Satellites wind observations (UARS, Swinbak et Ortland 1997) The Quasi-Biennial Oscillation (low stratosphere

Lott, Francois

8

Time Variability of the "Quiet" Sun Observed  

Science Journals Connector (OSTI)

We present a detailed analysis of the geometric and physical parameters of 281 EUV nanoflares, simultaneously detected with the TRACE telescope in the 171 and 195 Ĺ wavelengths. The detection and discrimination of these flarelike events is detailed in the first paper in this series. We determine the loop length l, loop width w, emission measure EM, the evolution of the electron density ne(t) and temperature Te(t), the flare decay time ?decay, and calculate the radiative loss time ?loss, the conductive loss time ?cond, and the thermal energy Eth. The findings are as follows: (1) EUV nanoflares in the energy range of 1024-1026 ergs represent miniature versions of larger flares observed in soft X-rays (SXR) and hard X-rays (HXR), scaled to lower temperatures (Te 2 MK), lower densities (ne 109 cm-3), and somewhat smaller spatial scales (l ? 2-20 Mm). (2) The cooling time ?decay is compatible with the radiative cooling time ?rad, but the conductive cooling timescale ?cond is about an order of magnitude shorter, suggesting repetitive heating cycles in time intervals of a few minutes. (3) The frequency distribution of thermal energies of EUV nanoflares, N(E) ? 10-46(E/1024)-1.8 (s-1 cm-2 ergs-1) matches that of SXR microflares in the energy range of 1026-1029, and exceeds that of nonthermal energies of larger flares observed in HXR by a factor of 3-10 (in the energy range of 1029-1032 ergs). Discrepancies of the power-law slope with other studies, which report higher values in the range of a = 2.0-2.6 (Krucker & Benz; Parnell & Jupp), are attributed to methodical differences in the detection and discrimination of EUV microflares, as well as to different model assumptions in the calculation of the electron density. Besides the insufficient power of nanoflares to heat the corona, we find also other physical limits for nanoflares at energies 1024 ergs, such as the area coverage limit, the heating temperature limit, the lower coronal density limit, and the chromospheric loop height limit. Based on these quantitative physical limitations, it appears that coronal heating requires other energy carriers that are not luminous in EUV, SXR, and HXR.

Markus J. Aschwanden; Ted D. Tarbell; Richard W. Nightingale; Carolus J. Schrijver; Alan Title; Charles C. Kankelborg; Piet Martens; Harry P. Warren

2000-01-01T23:59:59.000Z

9

Variable-Speed Wind Generator System with Maximum Output Power Control  

Science Journals Connector (OSTI)

To achieve maximum output power from wind generator systems, the rotational speed of wind generators should be adjusted in real time according to natural wind speed. This chapter pays attention to an optimum rota...

Yoko Amano

2013-01-01T23:59:59.000Z

10

Variable speed wind turbine for maximum power capture using adaptive fuzzy integral sliding mode control  

Science Journals Connector (OSTI)

This paper presents a nonlinear control approach to variable speed wind turbine (VSWT) with a wind speed estimator. The dynamics of the wind turbine (WT) is derived from single ... has been considered for exact e...

Saravanakumar Rajendran…

2014-06-01T23:59:59.000Z

11

Dynamics and variability of the plasmasphere observed from synchronous orbit  

SciTech Connect (OSTI)

The behavior of the cold ions in the outer plasmasphere is studied using data obtained with the magnetospheric plasma analyzers from multiple geosynchronous satellites. Dense (10-100 cm{sup {minus}3}), cold ({approx}1 eV) regions of plasma are often observed at geosynchronous orbit; in this study the authors refer to these as plasmaspheric intervals. The duration, local time of observation, density variability, and temperature behavior within these regions often depend in a systematic way on geomagnetic and substorm activity. With increasing geomagnetic activity (as indicated by Kp) the plasmaspheric regions are generally observed over shorter durations and at earlier local times. With increasing substorm activity (as indicated by geosynchronous energetic electron injections) the density becomes increasingly variable in these regions. Occasionally, up to order-of-magnitude density variations are observed over several minute timescales corresponding to regions with physical dimensions on the order of 1000 km or less. The appearance of these short-duration, cold-plasma intervals is strongly correlated with energetic ion and electron signatures both at the spacecraft making the plasmaspheric observations and at other spacecraft observing simultaneously in the midnight region. Such energetic particle signatures are indicative of the growth and expansive phase of geomagnetic substorms. The authors conclude that the appearance of these short-duration, plasmaspheric intervals is due to a reconfiguration of the duskside magnetosphere during geomagnetic substorms.

Moldwin, M.B.; Thomsen, M.F.; McComas, D.J.; Reeves, G.D.

1994-11-01T23:59:59.000Z

12

Observational Constraints of New Variable Modified Chaplygin Gas Model  

E-Print Network [OSTI]

Assuming the flat FRW universe in Einstein's gravity filled with New Variable Modified Chaplygin gas (NVMCG) dark energy and dark matter having negligible pressure. In this research work we analyze the viability on the basis of recent observation. Hubble parameter $H$ is expressed in terms of the observable parameters $H_0$, $\\Omega_m^0$ and the model parameters $A_0$, $B_0$, $C_0$, $m$, $n$, $\\alpha$ and the red shift parameter $z$. Here we find a best fitted parameter range of $A_0$, $B_0$ keeping $0\\leq \\alpha \\leq 1$ and using Stern data set (12 points) by minimizing the $\\chi^2$ test at 66%, 90% and 99% confidence levels. Next we do the joint analysis with BAO and CMB observations. Again evaluating the distance modulus $\\mu(z)$ vs redshift ($z$) curve obtained in the model NVMCG with dark matter with the best fitted value of the parameters and comparing with that derived from the union2 compilation data.

Jhumpa Bhadra; Ujjal Debnath

2012-11-09T23:59:59.000Z

13

OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT  

SciTech Connect (OSTI)

One of the defining characteristics of a solar flare is the impulsive formation of very high temperature plasma. The properties of the thermal emission are not well understood, however, and the analysis of solar flare observations is often predicated on the assumption that the flare plasma is isothermal. The EUV Variability Experiment (EVE) on the Solar Dynamics Observatory provides spectrally resolved observations of emission lines that span a wide range of temperatures (e.g., Fe XV-Fe XXIV) and allow for thermal flare plasma to be studied in detail. In this paper we describe a method for computing the differential emission measure distribution in a flare using EVE observations and apply it to several representative events. We find that in all phases of the flare the differential emission measure distribution is broad. Comparisons of EVE spectra with calculations based on parameters derived from the Geostationary Operational Environmental Satellites soft X-ray fluxes indicate that the isothermal approximation is generally a poor representation of the thermal structure of a flare.

Warren, Harry P.; Doschek, George A. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Mariska, John T. [School of Physics, Astronomy, and Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)

2013-06-20T23:59:59.000Z

14

Optimization of the transmission of observable expectation values and observable statistics in Continuous Variable Teleportation  

E-Print Network [OSTI]

We analyze the statistics of observables in continuous variable quantum teleportation in the formalism of the characteristic function. We derive expressions for average values of output state observables in particular cumulants which are additive in terms of the input state and the resource of teleportation. Working with Squeezed Bell-like states, which may be optimized in a free parameter for better teleportation performance we discuss the relation between resources optimal for fidelity and for different observable averages. We obtain the values of the free parameter which optimize the central momenta and cumulants up to fourth order. For the cumulants the distortion between in and out states due to teleportation depends only on the resource. We obtain optimal parameters for the second and fourth order cumulants which do not depend on the squeezing of the resource. The second order central momenta which is equal to the second order cumulants and the photon number average are optimized by the same resource. We show that the optimal fidelity resource, found in reference (Phys. Rev. A {\\bf 76}, 022301 (2007)) to depend also on the characteristics of input, tends for high squeezing to the resource which optimizes the second order momenta. A similar behavior is obtained for the resource which optimizes the photon statistics which is treated here using the sum of the squared differences in photon probabilities of input and output states as the distortion measure. This is interpreted to mean that the distortions associated to second order momenta dominates the behavior of the output state for large squeezing of the resource. Optimal fidelity and optimal photon statistics resources are compared and is shown that for mixtures of Fock states they are equivalent.

L. Albano Farias; J. Stephany

2010-09-28T23:59:59.000Z

15

Variability in active galactic nuclei: confrontation of models with observations  

Science Journals Connector (OSTI)

......flux. The time-scale of the light variation corresponds to the...However, observations of quasar light curves imply time-scales of...parameter sets to produce simulated light curves from which they can evaluate...had come to be known as the Christmas tree model (Pica Smith 1983......

M.R.S. Hawkins

2002-01-01T23:59:59.000Z

16

One-dimensional delayed-detonation models of Type Ia supernovae: Confrontation to observations at bolometric maximum  

E-Print Network [OSTI]

The delayed-detonation explosion mechanism applied to a Chandrasekhar-mass white dwarf offers a very attractive model to explain the inferred characteristics of Type Ia supernovae (SNe Ia). The resulting ejecta are chemically stratified, have the same mass and roughly the same asymptotic kinetic energy, but exhibit a range in 56Ni mass. We investigate the contemporaneous photometric and spectroscopic properties of a sequence of delayed-detonation models, characterized by 56Ni masses between 0.18 and 0.81 Msun. Starting at 1d after explosion, we perform the full non-LTE, time-dependent radiative transfer with the code CMFGEN, with an accurate treatment of line blanketing, and compare our results to SNe Ia at bolometric maximum. Despite the 1D treatment, our approach delivers an excellent agreement to observations. We recover the range of SN Ia luminosities, colours, and spectral characteristics from the near-UV to 1 micron, for standard as well as low-luminosity 91bg-like SNe Ia. Our models predict an increase...

Blondin, Stéphane; Hillier, D John; Khokhlov, Alexei M

2012-01-01T23:59:59.000Z

17

Searching for variable stars in the cores of five metal rich globular clusters using EMCCD observations  

E-Print Network [OSTI]

In this paper, we present the analysis of time-series observations from 2013 and 2014 of five metal rich ([Fe/H] $>$ -1) globular clusters: NGC~6388, NGC~6441, NGC~6528, NGC~6638, and NGC~6652. The data have been used to perform a census of the variable stars in the central parts of these clusters. The observations were made with the electron multiplying CCD (EMCCD) camera at the Danish 1.54m Telescope at La Silla, Chile, and they were analysed using difference image analysis (DIA) to obtain high-precision light curves of the variable stars. It was possible to identify and classify all of the previously known or suspected variable stars in the central regions of the five clusters. Furthermore, we were able to identify, and in most cases classify 48, 49, 7, 8, and 2 previously unknown variables in NGC~6388, NGC~6441, NGC~6528, NGC~6638, and NGC~6652, respectively. Especially interesting is the case of NGC~6441, for which the variable star population of about 150 stars has been thoroughly examined by previous s...

Skottfelt, Jesper; Jaimes, R Figuera; Jřrgensen, U G; Kains, N; Ferro, A Arellano; Alsubai, K A; Bozza, V; Novati, S Calchi; Ciceri, S; DAgo, G; Dominik, M; Galianni, P; Gu, S -H; Harpsře, K B W; Haugbřlle, T; Hinse, T C; Hundertmark, M; Juncher, D; Korhonen, H; Liebig, C; Mancini, L; Popovas, A; Rabus, M; Rahvar, S; Scarpetta, G; Schmidt, R W; Snodgrass, C; Southworth, J; Starkey, D; Street, R A; Surdej, J; Wang, X -B; Wertz, O

2014-01-01T23:59:59.000Z

18

Observations of the cataclysmic variable SDSS J081321.91+452809.4  

E-Print Network [OSTI]

Our observations of the first reported outburst of SDSS J081321.91+452809.4 during 2008 April show that this cataclysmic variable is a dwarf nova. The outburst amplitude was at least 3.1 magnitudes and the outburst appears to have been rather short-lived at around 3 days with a rapid decline to quiescence of 0.73 mag/day.

Jeremy Shears; Ian Miller; Steve Brady

2008-12-12T23:59:59.000Z

19

The variable hard X-ray emission of NGC4945 as observed by NuSTAR  

E-Print Network [OSTI]

We present a broadband (~0.5-79 keV) spectral and temporal analysis of multiple NuSTAR observations combined with archival Suzaku and Chandra data of NGC4945, the brightest extragalactic source at 100 keV. We observe hard X-ray (> 10 keV) flux and spectral variability, with flux variations of a factor 2 on timescales of 20 ksec. A variable primary continuum dominates the high energy spectrum (>10 keV) in all the states, while the reflected/scattered flux which dominates at Etransmission spectrum we derive a Compton depth along the line of sight of tau_Thomson ~ 2.9, and a global covering factor for the circumnuclear gas of ~ 0.15. This agrees with the constraints derived from the high energy variability, which implies that most of the high energy flux is transmitted, rather that Compton-scattered. This demonstrates the effectiveness of spectral analysis in constraining the geometric properties of the circumnuclear gas, and validat...

Puccetti, Simonetta; Fiore, Fabrizio; Arévalo, Patricia; Risaliti, Guido; Bauer, Franz E; Brandt, William N; Stern, Daniel; Harrison, Fiona A; Alexander, David M; Boggs, Steve E; Christensen, Finn E; Craig, William W; Gandhi, Poshak; Hailey, Charles J; Koss, Michael R; Lansbury, George B; Luo, Bin; Madejski, Greg M; Matt, Giorgio; Walton, Dominic J; Zhang, Will

2014-01-01T23:59:59.000Z

20

PHOTOMETRY OF VARIABLE STARS FROM DOME A, ANTARCTICA: RESULTS FROM THE 2010 OBSERVING SEASON  

SciTech Connect (OSTI)

We present results from a season of observations with the Chinese Small Telescope ARray, obtained over 183 days of the 2010 Antarctic winter. We carried out high-cadence time-series aperture photometry of 9125 stars with i ?< 15.3 mag located in a 23 deg{sup 2} region centered on the south celestial pole. We identified 188 variable stars, including 67 new objects relative to our 2008 observations, thanks to broader synoptic coverage, a deeper magnitude limit, and a larger field of view. We used the photometric data set to derive site statistics from Dome A. Based on two years of observations, we find that extinction due to clouds at this site is less than 0.1 and 0.4 mag during 45% and 75% of the dark time, respectively.

Wang, Lingzhi; Zhu, Zonghong [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Macri, Lucas M.; Wang, Lifan [Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Ashley, Michael C. B.; Lawrence, Jon S.; Luong-Van, Daniel; Storey, John W. V. [School of Physics, University of New South Wales, NSW 2052 (Australia); Cui, Xiangqun; Feng, Long-Long; Gong, Xuefei; Liu, Qiang; Shang, Zhaohui; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhou, Xu; Zhu, Zhenxi [Chinese Center for Antarctic Astronomy, Nanjing 210008 (China); Pennypacker, Carl R. [Center for Astrophysics, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); York, Donald G., E-mail: wanglingzhi@bao.ac.cn [Department of Astronomy and Astrophysics and Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States)

2013-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

RApid Temporal Survey - RATS II: Followup observations of 4 newly discovered short period variables  

E-Print Network [OSTI]

The RApid Temporal Survey (RATS) is a survey to detect objects whose optical intensity varies on timescales of less than ~70 min. In our pilot dataset taken with the INT and the Wide Field Camera in Nov 2003 we discovered nearly 50 new variable objects. Many of these varied on timescales much longer than 1 hr. However, only 4 objects showed a modulation on a timescale of 1 hour or less. This paper presents followup optical photometry and spectroscopy of these 4 objects. We find that RAT J0455+1305 is a pulsating (on a period of 374 sec) subdwarf B (sdB) star of the EC 14026 type. We have modelled its spectrum and determine Teff = 29,200+/- 1900K and log g = 5.2+/-0.3 which locates it on the cool edge of the EC 14026 instability strip. It has a modulation amplitude which is one of the highest of any known EC 14026 star. Based on their spectra, photometric variability and their infra-red colours, we find that RAT J0449+1756, RAT J0455+1254 and RAT J0807+1510 are likely to be SX Phe stars - dwarf Delta Sct stars. Our results show that our observing strategy is a good method for finding rare pulsating stars.

Gavin Ramsay; Ralf Napiwotzki; Pasi Hakala; Harry Lehto

2006-06-26T23:59:59.000Z

22

Wind variability in the northwestern part of the Black Sea from the offshore fixed platform observation data  

Science Journals Connector (OSTI)

The statistically ensured estimates of characteristics of temporal variability of wind speed and wind direction are obtained on the basis of ... observations carried out in 1996–2001 at the offshore fixed platfor...

A. V. Garmashov; A. B. Polonskii

2011-12-01T23:59:59.000Z

23

MULTI-EPOCH OBSERVATIONS OF HD 69830: HIGH-RESOLUTION SPECTROSCOPY AND LIMITS TO VARIABILITY  

SciTech Connect (OSTI)

The main-sequence solar-type star HD 69830 has an unusually large amount of dusty debris orbiting close to three planets found via the radial velocity technique. In order to explore the dynamical interaction between the dust and planets, we have performed multi-epoch photometry and spectroscopy of the system over several orbits of the outer dust. We find no evidence for changes in either the dust amount or its composition, with upper limits of 5%-7% (1{sigma} per spectral element) on the variability of the dust spectrum over 1 year, 3.3% (1{sigma}) on the broadband disk emission over 4 years, and 33% (1{sigma}) on the broadband disk emission over 24 years. Detailed modeling of the spectrum of the emitting dust indicates that the dust is located outside of the orbits of the three planets and has a composition similar to main-belt, C-type asteroids in our solar system. Additionally, we find no evidence for a wide variety of gas species associated with the dust. Our new higher signal-to-noise spectra do not confirm our previously claimed detection of H{sub 2}O ice leading to a firm conclusion that the debris can be associated with the break-up of one or more C-type asteroids formed in the dry, inner regions of the protoplanetary disk of the HD 69830 system. The modeling of the spectral energy distribution and high spatial resolution observations in the mid-infrared are consistent with a {approx}1 AU location for the emitting material.

Beichman, C. A.; Tanner, A. M.; Bryden, G.; Akeson, R. L.; Ciardi, D. R. [NASA Exoplanet Science Institute, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91125 (United States); Lisse, C. M. [Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 (United States); Boden, A. F. [Caltech Optical Observatories, California Institute of Technology, Pasadena, CA 91125 (United States); Dodson-Robinson, S. E.; Salyk, C. [University of Texas, Astronomy Department, Austin, TX 78712 (United States); Wyatt, M. C., E-mail: chas@pop.jpl.nasa.gov [Institute of Astronomy, University of Cambridge, Cambridge, CB3 0HA (United Kingdom)

2011-12-10T23:59:59.000Z

24

An objective analysis of the observed spatial structure of the tropical Indian Ocean SST variability  

E-Print Network [OSTI]

-mode, which influences the SST variability in the Indian quite significantly (e.g. Bjerknes 1969; Weare 1979; Latif and Barnett 1995). D. Dommenget (&) Leibniz Institute of Marine Sciences, IFM-GEOMAR, Du

Dommenget, Dietmar

25

Observed and modeled relationships among Arctic climate variables Yonghua Chen, James R. Miller, and Jennifer A. Francis  

E-Print Network [OSTI]

in our understanding of these processes. In addition to the traditional approach of validating individual variables with observed fields, we demonstrate that a comparison of covariances among interrelated and Atmospheric Dynamics: Polar meteorology; 3359 Meteorology and Atmospheric Dynamics: Radiative processes; 9315

Aires, Filipe

26

Interannual and seasonal variability of biomass burning emissions constrained by satellite observations  

E-Print Network [OSTI]

--composition and chemistry; KEYWORDS: Biomass burning, interannual seasonal variation Citation: Duncan, B. N., R. V. Martin, A. C. Staudt, R. Yevich, and J. A. Logan, Interannual and seasonal variability of biomass burning [Malingreau, 1990; Stricker et al., 1995; Hsu et al., 1996; Cooke et al., 1996; Justice et al., 1996; Herman

Jacob, Daniel J.

27

Modelled and observed variability of the atmospheric circulation the Peruvian Current System: 2000-2005  

E-Print Network [OSTI]

on the characteristics of the local equatorward atmospheric circulation. Resolving the mesoscale variability of the heat Mesoscale Model (MM5) and Weather Research and Forecasting (WRF) that were run over the Peruvian Current System (PCS) [0N-19°S; 83°W-68°W] from November 2000- October 2005. Wind data as derived from

28

CoRoT observations of O stars: diverse origins of variability  

E-Print Network [OSTI]

Six O-type stars were observed continuously by the CoRoT satellite during a 34.3-day run. The unprecedented quality of the data allows us to detect even low-amplitude stellar pulsations in some of these stars (HD 46202 and the binaries HD 46149 and Plaskett's star). These cover both opacity-driven modes and solar-like stochastic oscillations, both of importance to the asteroseismological modelling of O stars. Additional effects can be seen in the CoRoT light curves, such as binarity and rotational modulation. Some of the hottest O-type stars (HD 46223, HD 46150 and HD 46966) are dominated by the presence of red-noise: we speculate that this is related to a sub-surface convection zone.

Blomme, R; Degroote, P; Mahy, L; Aerts, C; Cuypers, J; Godart, M; Gosset, E; Hareter, M; Montalban, J; Morel, T; Nieva, M F; Noels, A; Oreiro, R; Poretti, E; Przybilla, N; Rainer, M; Rauw, G; Schiller, F; Simon-Diaz, S; Smolders, K; Ventura, P; Vuckovic, M; Auvergne, M; Baglin, A; Baudin, F; Catala, C; Michel, E; Samadi, R

2011-01-01T23:59:59.000Z

29

Year-round observations of carbon biomass and flux variability in the Southern Ocean  

SciTech Connect (OSTI)

Three Carbon Explorer (CE) floats profiling to kilometer depths in the Southern Ocean tracked dawn-dusk variations of mixing/stratification, particulate organic carbon (POC), and light scattering and sedimentation at 100, 250, and 800 m continuously from January 2002 to April 2003. Data were analyzed in conjunction with contemporaneous satellite winds and chlorophyll and derived subsurface light fields. The CE deployed at 66{sup o}S 172{sup o}W operated in the ice edge zone in absence of light. Two CEs deployed at 55{sup o}S 172{sup o}W recorded wintertime mixing to {approx}400 m, yet observed very different bloom dynamics and sedimentation the following spring. Four hypotheses are explored. The strongest is that shallow transient stratification of the deep winter mixed layer to shallower than photosynthetic critical depth occurred more frequently in the non-bloom/higher sedimentation case. The lower particle export to 800 m under the bloom was hypothesized to be due to higher interception of sinking carbon by a relatively starved over wintering zooplankton population. In the Southern Ocean surface phytoplankton biomass may counter indicate particle flux at kilometer depths.

Bishop, James K.B.; Wood, Todd

2009-02-01T23:59:59.000Z

30

EXPLORING THE MECHANISMS OF VARIABILITY IN CLASS I AND II YSOS WITH TWO-EPOCH HST/NICMOS OBSERVATIONS. A. S. Cotera1  

E-Print Network [OSTI]

to variable accretion processes onto the stellar photosphere [e.g. 2]. The timescales of the variability of the objects, L1551 IRS 5 and HH 30 were observed as part of GTO 7228 (PI: Young), while the other five, Co

Schneider, Glenn

31

SHORT-TERM VARIABILITY OF X-RAYS FROM ACCRETING NEUTRON STAR VELA X-1. I. SUZAKU OBSERVATIONS  

SciTech Connect (OSTI)

We have analyzed the time variability of the wide-band X-ray spectrum of Vela X-1, the brightest wind-fed accreting neutron star, on a short timescale of 2 ks by using Suzaku observations with an exposure of 100 ks. During the observation, the object showed strong variability, including several flares and so-called 'low states', in which the X-ray luminosity decreases by an order of magnitude. Although the spectral hardness increases with the X-ray luminosity, the majority of the recorded flares do not show any significant changes in circumstellar absorption. However, a sign of heavy absorption was registered immediately before one short flare that showed a significant spectral hardening. In the low states, the flux level is modulated with the pulsar spin period, indicating that even at this state the accretion flow reaches the close proximity of the neutron star. Phenomenologically, the broadband X-ray spectra, which are integrated over the entire spin phase, are well represented by the 'NPEX' function (a combination of negative and positive power laws with an exponential cutoff by a common folding energy) with a cyclotron resonance scattering feature at 50 keV. Fitting of the data allowed us to infer a correlation between the photon index and X-ray luminosity. Finally, the circumstellar absorption shows a gradual increase in the orbital phase interval 0.25-0.3, which can be interpreted as an impact of a bow shock imposed by the motion of the compact object in the supersonic stellar wind.

Odaka, Hirokazu; Khangulyan, Dmitry; Watanabe, Shin; Takahashi, Tadayuki [Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan)] [Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Tanaka, Yasuyuki T. [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)] [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Makishima, Kazuo [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)] [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan)

2013-04-10T23:59:59.000Z

32

SWIFT XRT Observations of the Nova-like Cataclysmic Variables MV Lyr, BZ Cam and V592 Cas  

E-Print Network [OSTI]

We present a total of ~ 45 ksec (3$\\times$15 ksec) of SWIFT XRT observations for three non-magnetic nova-like (NL) Cataclysmic Variables (CVs) (MV Lyr, BZ Cam, V592 Cas) in order to study characteristics of Boundary Layers (BL) in CVs. The nonmagnetic NLs are found mostly in a state of high mass accretion rate ($\\ge$1$\\times$10$^{-9}$ Msun yr$^{-1}$) and some show occasional low states. Using the XRT data, we find optically thin multiple-temperature cooling flow type emission spectra with X-ray temperatures (kT$_{max}$) of 21-50 keV. These hard X-ray emitting boundary layers diverge from simple isobaric cooling flows indicating X-ray temperatures that are of virial values in the disk. In addition, we detect power law emission components from MV Lyr and BZ Cam and plausibly from V592 Cas which may be a result of the Compton scattering of the optically thin emission from the fast wind outflows in these systems and/or Compton up-scattering of the soft disk photons. The X-ray luminosities of the (multi-temperatur...

Balman, Solen; Sion, Edward M

2014-01-01T23:59:59.000Z

33

Variability in the North Atlantic Deep Western Boundary Current : upstream causes and downstream effects as observed at Line W  

E-Print Network [OSTI]

The variability in the DWBC, its connection to the forcing in the northern North Atlantic and interaction with the Gulf Stream were explored from a combination of remote sensing and in-situ measurements in the western North ...

Peńa-Molino, Beatriz

2010-01-01T23:59:59.000Z

34

KEPLER OBSERVATIONS OF RAPID OPTICAL VARIABILITY IN THE BL LACERTAE OBJECT W2R1926+42  

SciTech Connect (OSTI)

We present the first Kepler monitoring of a strongly variable BL Lac, W2R1926+42. The light curve covers 181 days with {approx}0.2% errors, 30 minute sampling and >90% duty cycle, showing numerous {delta}I/I > 25% flares over timescales as short as a day. The flux distribution is highly skewed and non-Gaussian. The variability shows a strong rms-flux correlation with the clearest evidence to date for nonlinearity in this relation. We introduce a method to measure periodograms from the discrete autocorrelation function, an approach that may be well-suited to a wide range of Kepler data. The periodogram is not consistent with a simple power-law, but shows a flattening at frequencies below 7 Multiplication-Sign 10{sup -5} Hz. Simple models of the power spectrum, such as a broken power law, do not produce acceptable fits, indicating that the Kepler blazar light curve requires more sophisticated mathematical and physical descriptions than currently in use.

Edelson, R.; Mushotzky, R. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)] [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Vaughan, S. [X-ray and Observational Astronomy Group, Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)] [X-ray and Observational Astronomy Group, Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Scargle, J. [Astrobiology and Space Science Division, NASA Ames Research Center, Moffet Field, CA 94035 (United States)] [Astrobiology and Space Science Division, NASA Ames Research Center, Moffet Field, CA 94035 (United States); Gandhi, P. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)] [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Malkan, M. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095-1547 (United States)] [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095-1547 (United States); Baumgartner, W., E-mail: redelson@astro.umd.edu [Laboratory for High Energy Astrophysics, NASA/GSFC, Code 662, Greenbelt, MD 20771 (United States)

2013-03-20T23:59:59.000Z

35

Time-variable gravity observations of ice sheet mass balance: Precision and limitations of the GRACE satellite data  

E-Print Network [OSTI]

contribution to sea-level rise observed by GRACE withand ice caps to sea level rise, Nature, 482, 514–518. King,ice sheets to sea level rise, Geophys. Res. Lett. , 38,

Velicogna, I.; Wahr, J.

2013-01-01T23:59:59.000Z

36

Nonlinear optics at maximum coherence  

Science Journals Connector (OSTI)

...D. Walls Nonlinear optics at maximum coherence S. E. Harris G. Y. Yin M. Jain H...optical processes which utilize maximum coherence of a non-allowed transition. The nonlinear...frequency. Nonlinear optics at maximum coherence B y S. E. Harris, G. Y. Yin, M...

1997-01-01T23:59:59.000Z

37

Observations of internal tide variability in the far field of the Hawaiian Ridge: The far field component of the Hawaii Ocean Mixing Experiment (HOME)  

Science Journals Connector (OSTI)

As part of the Hawaii Ocean Mixing Experiment (HOME) observations of internal tides in two regions on either side of the Hawaiian Ridge were obtained by tomography thermistors and CTD casts from FLIP. The tomographic observations detect radiation of low internal?tide modes in broad areas while the thermistors and CTD casts measure the ‘‘local’’ internal?tide variability. These observations are used to estimate the amount of energy carried away from the Ridge by the internal tides to estimate the relative energies of low? and high?mode internal tides and to test numerical models of internal?tide generation. Barotropic currents and pressure were also measured by tomography electromagnetic and pressure sensors so that with careful modeling the energy lost from the barotropic tides at the Ridge can be determined. Thermistor data obtained on one mooring showed that the M2 mode?1 internal tide was mainly phase?locked and carried 1.3 kW/m of energy. Modes 2 and 3 had amplitudes comparable to mode?1 but they were not phase locked. Energy fluxes at three other moorings were 1.2 2.0 and 6.7 kW/m. Energy fluxes obtained by tomography were 0 (1 kW/m) or less; the line?integral data are less susceptible to the interference effects in the outgoing internal waves.

2002-01-01T23:59:59.000Z

38

MaximumLetThrough.PDF  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

9 9 Maximum Let-Through Currents in the APS Storage Ring Quadrupole, Sextupole, and Corrector Magnets J. Carwardine, D. McGhee, G. Markovich May 18, 1999 Abstract Limits are described for the maximum magnet currents, under specified fault conditions, for the storage ring quadrupole, sextupole, and corrector magnets. Introduction In computing the maximum let-through current for the magnets for the storage ring, several factors must be considered. In general, the maximum current likely to occur even under fault conditions is less than the maximum theoretical DC current given the magnet resistance and the maximum available DC voltage. The first level of protection against magnet current overloads is the over-current interlock that is built into the converter electronics package. The threshold is set to approximately 110% of

39

Single ion heat engine with maximum efficiency at maximum power  

E-Print Network [OSTI]

We propose an experimental scheme to realize a nano heat engine with a single ion. An Otto cycle may be implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered laser reservoirs. The quantum efficiency at maximum power is analytically determined in various regimes. Moreover, Monte Carlo simulations of the engine are performed that demonstrate its feasibility and its ability to operate at maximum efficiency of 30% under realistic conditions.

Obinna Abah; Johannes Rossnagel; Georg Jacob; Sebastian Deffner; Ferdinand Schmidt-Kaler; Kilian Singer; Eric Lutz

2012-05-07T23:59:59.000Z

40

Maximum power tracking control scheme for wind generator systems  

E-Print Network [OSTI]

The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

Mena, Hugo Eduardo

2009-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Maximum power tracking control scheme for wind generator systems  

E-Print Network [OSTI]

The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...

Mena Lopez, Hugo Eduardo

2008-10-10T23:59:59.000Z

42

Reply to 'Comment on 'All quantum observables in a hidden-variable model must commute simultaneously'' [Phys. Rev. A 73, 066101 (2006)  

SciTech Connect (OSTI)

Nagata [Phys. Rev. A 73, 066101 (2006)] questions whether a general no-go theorem of Malley [Phys. Rev. A 69, 022118 (2004)] applies to local hidden variables and outlines a 'counterexample.' In fact this is not a counterexample at all, but in seeing why it fails we clarify the significance of Malley's result and its relation to other no-go theorems.

Malley, J. D. [Center for Information Technology, NIH, Bethesda, Maryland 20892 (United States); Fine, A. [Department of Philosophy, University of Washington, Seattle, Washington 98195 (United States)

2006-06-15T23:59:59.000Z

43

Boiler Maximum Achievable Control Technology (MACT) Technical...  

Broader source: Energy.gov (indexed) [DOE]

Boiler Maximum Achievable Control Technology (MACT) Technical Assistance - Fact Sheet, May 2014 Boiler Maximum Achievable Control Technology (MACT) Technical Assistance - Fact...

44

Maximum entanglement in squeezed boson and fermion states  

SciTech Connect (OSTI)

A class of squeezed boson and fermion states is studied with particular emphasis on the nature of entanglement. We first investigate the case of bosons, considering two-mode squeezed states. Then we construct the fermion version to show that such states are maximum entangled, for both bosons and fermions. To achieve these results, we demonstrate some relations involving squeezed boson states. The generalization to the case of fermions is made by using Grassmann variables.

Khanna, F. C. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Malbouisson, J. M. C. [Instituto de Fisica, Universidade Federal da Bahia, 40210-340, Salvador, BA (Brazil); Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Santana, A. E. [Instituto de Fisica, Universidade de Brasilia, 70910-900, Brasilia, DF (Brazil); Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Santos, E. S. [Centro Federal de Educacao Tecnologica da Bahia, 40030-010, Salvador, BA (Brazil)

2007-08-15T23:59:59.000Z

45

Maximum Principles in Analytical Economics  

Science Journals Connector (OSTI)

...what he is saying is that the sci-entist who formulates laws of observed empirical phenomena is essentially an economist or economizer. Nonetheless, I must point out that these distinct roles are, almost by coin-cidence so to speak, closely related...

Paul A. Samuelson

1971-09-10T23:59:59.000Z

46

Vegetation and Fire at the Last Glacial Maximum in Tropical South America  

E-Print Network [OSTI]

Chapter 4 Vegetation and Fire at the Last Glacial Maximum in Tropical South America Francis E temperatures. Keywords Charcoal · Last Glacial Maximum · pollen · Quaternary · tropical South America F-mail: Francis.Mayle@ed.ac.uk 89F. Vimeux et al. (eds.), Past Climate Variability in South America

Binford, Michael W.

47

Spatial Variability in the Ratio of Interstellar Atomic Deuterium to Hydrogen. I. Observations toward delta Orionis by the Interstellar Medium Absorption Profile Spectrograph  

E-Print Network [OSTI]

Studies of the abundances of deuterium in different astrophysical sites are of fundamental importance to answering the question about how much deuterium was produced during big bang nucleosynthesis and what fraction of it was destroyed later. With this in mind, we used the Interstellar Medium Absorption Profile Spectrograph (IMAPS) on the ORFEUS-SPAS II mission to observe at a wavelength resolution of 4 km/s (FWHM) the L-delta and L-epsilon absorption features produced by interstellar atomic deuterium in the spectrum of delta Ori A. A chi-square analysis indicated that 0.96 atomic ratio of D to H, we measured the L-alpha absorption features in 57 spectra of delta Ori in the IUE archive. From our measurement of N(H I)= 1.56e20 cm^{-2}, we found that N(D I)/N(H I)= 7.4(+1.9,-1.3)e-6 (90% confidence). Our result for D/H contrasts with the more general finding along other lines of sight that D/H is approximately 1.5e-5. The underabundance of D toward delta Ori A is not accompanied by an overabundance of N or O relative to H, as one might expect if the gas were subjected to more stellar processing than usual.

Edward B. Jenkins; Todd M. Tripp; Przemyslaw R. Wozniak; Ulysses J. Sofia; G. Sonneborn

1999-01-28T23:59:59.000Z

48

Maximum stellar mass versus cluster membership number revisited  

E-Print Network [OSTI]

We have made a new compilation of observations of maximum stellar mass versus cluster membership number from the literature, which we analyse for consistency with the predictions of a simple random drawing hypothesis for stellar mass selection in clusters. Previously, Weidner and Kroupa have suggested that the maximum stellar mass is lower, in low mass clusters, than would be expected on the basis of random drawing, and have pointed out that this could have important implications for steepening the integrated initial mass function of the Galaxy (the IGIMF) at high masses. Our compilation demonstrates how the observed distribution in the plane of maximum stellar mass versus membership number is affected by the method of target selection; in particular, rather low n clusters with large maximum stellar masses are abundant in observational datasets that specifically seek clusters in the environs of high mass stars. Although we do not consider our compilation to be either complete or unbiased, we discuss the method by which such data should be statistically analysed. Our very provisional conclusion is that the data is not indicating any striking deviation from the expectations of random drawing.

Th. Maschberger; C. J. Clarke

2008-08-29T23:59:59.000Z

49

Higher Order Maximum Persistency and Comparison Theorems  

E-Print Network [OSTI]

discrete variables (energy minimization in graphical models, weighted constraint ... 1.2 Energy Minimization . ...... This is useful in proofs, providing an alternative.

2014-10-15T23:59:59.000Z

50

Property:Maximum Wave Length(m) | Open Energy Information  

Open Energy Info (EERE)

Wave Length(m) Wave Length(m) Jump to: navigation, search Property Name Maximum Wave Length(m) Property Type String Pages using the property "Maximum Wave Length(m)" Showing 18 pages using this property. A Alden Small Flume + Variable + Alden Wave Basin + 1.8 + C Carderock Maneuvering & Seakeeping Basin + 12.2 + Carderock Tow Tank 2 + 12.2 + Carderock Tow Tank 3 + 12.2 + D Davidson Laboratory Tow Tank + 15.2 + DeFrees Large Wave Basin + 64 + DeFrees Small Wave Basin + 30 + H Haynes Wave Basin + 10.7 + L Lakefront Tow Tank + 22 + M MIT Tow Tank + 4.6 + O OTRC Wave Basin + 25 + Ohmsett Tow Tank + 18 + R Richmond Field Station Tow Tank + 2 + S SAFL Channel + 6.6 + Sandia Lake Facility + 4.57 + Sheets Wave Basin + 10 + Ship Towing Tank + 6 + Retrieved from "http://en.openei.org/w/index.php?title=Property:Maximum_Wave_Length(m)&oldid=597351

51

Maximum entropy method for reconstruction of the CMB images  

E-Print Network [OSTI]

We propose a new approach for the accurate reconstruction of cosmic microwave background distributions from observations containing in addition to the primary fluctuations the radiation from unresolved extragalactic point sources and pixel noise. The approach uses some effective realizations of the well-known maximum entropy method and principally takes into account {\\it a priori} information about finiteness and spherical symmetry of the power spectrum of the CMB satisfying the Gaussian statistics.

A. T. Bajkova

2002-05-21T23:59:59.000Z

52

Performance Variability  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Variability Variability of Highly Parallel Architectures William T.C. Kramer 1 and Clint Ryan 2 1 Department of Computing Sciences, University of California at Berkeley and the National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory 2 Department of Computing Sciences, University of California at Berkeley Abstract. The design and evaluation of high performance computers has concentrated on increasing computational speed for applications. This performance is often measured on a well configured dedicated sys- tem to show the best case. In the real environment, resources are not always dedicated to a single task, and systems run tasks that may influ- ence each other, so run times vary, sometimes to an unreasonably large extent. This paper explores the amount of variation seen across four large distributed memory systems in a systematic manner. It then

53

Cell development obeys maximum Fisher information  

E-Print Network [OSTI]

Eukaryotic cell development has been optimized by natural selection to obey maximal intracellular flux of messenger proteins. This, in turn, implies maximum Fisher information on angular position about a target nuclear pore complex (NPR). The cell is simply modeled as spherical, with cell membrane (CM) diameter 10 micron and concentric nuclear membrane (NM) diameter 6 micron. The NM contains about 3000 nuclear pore complexes (NPCs). Development requires messenger ligands to travel from the CM-NPC-DNA target binding sites. Ligands acquire negative charge by phosphorylation, passing through the cytoplasm over Newtonian trajectories toward positively charged NPCs (utilizing positive nuclear localization sequences). The CM-NPC channel obeys maximized mean protein flux F and Fisher information I at the NPC, with first-order delta I = 0 and approximate 2nd-order delta I = 0 stability to environmental perturbations. Many of its predictions are confirmed, including the dominance of protein pathways of from 1-4 proteins, a 4nm size for the EGFR protein and the approximate flux value F =10^16 proteins/m2-s. After entering the nucleus, each protein ultimately delivers its ligand information to a DNA target site with maximum probability, i.e. maximum Kullback-Liebler entropy HKL. In a smoothness limit HKL approaches IDNA/2, so that the total CM-NPC-DNA channel obeys maximum Fisher I. Thus maximum information approaches non-equilibrium, one condition for life.

B. R. Frieden; R. A. Gatenby

2014-04-29T23:59:59.000Z

54

Comparison of VLF Wave Activity in the Solar Wind During Solar Maximum and Minimum  

E-Print Network [OSTI]

second fast latitude scan (near the solar maximum) with the wave observations during the first fast Experiments (URAP) of Ulysses during its first orbit, which occurred when the solar activity was approachingComparison of VLF Wave Activity in the Solar Wind During Solar Maximum and Minimum: Ulysses

California at Berkeley, University of

55

Notes on Frequentist, Maximum Likelihood & Bayesian Statistics  

E-Print Network [OSTI]

, theory, "gut feeling," etc. · Changes the probability distribution #12;Bayesian Statistics · ProbabilityNotes on Frequentist, Maximum Likelihood & Bayesian Statistics #12;Statistical Methods · Probability is a long-term frequency statement about the data ­ if repeated, what proportion of the time would

Ernest, Holly

56

PublicationsmailagreementNo.40014024 maximum depth  

E-Print Network [OSTI]

and a video camera to complete installation of the world's first regional cabled ocean observatory. NEPTUNE- tion systems that--using power and the internet--provide continuous, long-term monitoring of oceanPublicationsmailagreementNo.40014024 THE 2.7km maximum depth beneath the ocean surface of neptune

Pedersen, Tom

57

Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum  

E-Print Network [OSTI]

Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...

Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W

2015-01-01T23:59:59.000Z

58

A new scanning photoemission microscope for ELETTRA: SuperMAXIMUM  

Science Journals Connector (OSTI)

High brightness third?generation synchrotrons allow diffraction?limited performance and large flux for scanning photoemission microscopes. A new microscope SuperMAXIMUM is being developed at the University of Wisconsin Center for X ray Lithography in collaboration with the Sincrotrone Trieste. The beamline being built in Trieste uses a variable angle spherical gratingmonochromator (VASGM). A combination of rotation of a plane mirror and rotation of the spherical grating keeps the slit positions and beam directions fixed. The microscope objectives are normal?incidence multilayer?coated Schwarzschild objectives. The project which is nearing completion utilizes novel designs for optics alignment sample rastering mechanics and software control. We will discuss the project status new designs and techniques.

John T. Welnak; H. Solak; J. Wallace; F. Cerrina; F. Barbo; M. Bertolo; A. Bianco; S. Di Fonzo; S. Fontana; W. Jark; F. Mazzolini; R. Rosei; A. Savoia; J.H. Underwood; G. Margaritondo

1996-01-01T23:59:59.000Z

59

A new scanning photoemission microscope for ELETTRA: SuperMAXIMUM  

SciTech Connect (OSTI)

High brightness, third-generation synchrotrons allow diffraction-limited performance and large flux for scanning photoemission microscopes. A new microscope, SuperMAXIMUM, is being developed at the University of Wisconsin Center for X ray Lithography in collaboration with the Sincrotrone Trieste. The beamline, being built in Trieste, uses a variable angle spherical grating monochromator (VASGM). A combination of rotation of a plane mirror and rotation of the spherical grating keeps the slit positions and beam directions fixed. The microscope objectives are normal-incidence, multilayer-coated Schwarzschild objectives. The project, which is nearing completion, utilizes novel designs for optics alignment, sample rastering mechanics, and software control. We will discuss the project status, new designs, and techniques. {copyright} {ital 1996 American Institute of Physics.}

Welnak, J.T.; Solak, H.; Wallace, J.; Cerrina, F.; Barbo, F.; Bertolo, M.; Bianco, A.; Di Fonzo, S.; Fontana, S.; Jark, W.; Mazzolini, F.; Rosei, R.; Savoia, A.; Underwood, J.; Margaritondo, G. [University of WI--Center for X ray Lithography, 3731 Schneider Drive, Stoughton, WI 53589 (United States)] [University of WI--Center for X ray Lithography, 3731 Schneider Drive, Stoughton, WI 53589 (United States); [Sincrotrone Trieste, Padriciano 99, 34012, Trieste (Italy); [Lawrence Berkeley Laboratory, Center for X ray Optics, 1 Cyclotron Road, 80-101, Berkeley, CA 94720 (United States); [Institut de Physique Appliqee, Ecole Polytechnique Federale, CH-1015, Lausanne (Switzerland)

1996-09-01T23:59:59.000Z

60

Design of maximum density aggregate grading  

Science Journals Connector (OSTI)

An aggregate grading that yields maximum solid density and maximum particle interlock is highly desirable for both bound mixtures, such as asphalt concrete and plain and reinforced concrete, and for unbound mixtures such as those used in base courses. Maximum particle interlock leads to high strength. Whereas minimum voids in a certain material composition is conducive to high strength and low compression. Aggregate grading may be obtained, for instance, from the ASTM, which is based on experience or may be designed according to Lees’ method. In the present work five different types of aggregates were used, each with a variety of chosen grading. It was found that Lees’ method produced the lowest porosity of all types of aggregates as well as for the various employed gradings. Lees’ rational method of aggregate grading, however, is a very lengthy and time-consuming procedure. Therefore, programming of Lees’ method is an essential step to make such an excellent method available to practicing engineers. A program named ‘ratmix’ was developed and has incorporated 58 design graphs of the Lees’ method. ratmix is a comprehensive program for Lees’ rational method; it conducts interpolation for intermediate points within the design graphs as well as between graphs of different properties.

Yahia A Abdel-Jawad; Waddah Salman Abdullah

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Maximum likelihood reconstruction for the Daya Bay Experiment  

E-Print Network [OSTI]

The Daya Bay Reactor Neutrino experiment is designed to precisely determine the neutrino mixing angle theta13. In this paper, we report a maximum likelihood (ML) method to reconstruct the vertex and energy of events in the anti-neutrino detector, based on a simplified optical model that describes light propagation. We calibrate the key paramters of the optical model with Co60 source, by comparing the predicted charges of the PMTs with the observed charges. With the optimized parameters, the resolution of the vertex reconstruction is about 25cm for Co60 gamma.

Xia Dongmei

2014-03-07T23:59:59.000Z

62

Accelerated maximum likelihood parameter estimation for stochastic biochemical systems  

E-Print Network [OSTI]

as: Daigle et al. : Accelerated maximum likelihood parame-Gillespie DT: Approximate accelerated stochastic simulationARTICLE Open Access Accelerated maximum likelihood parameter

Daigle, Bernie J; Roh, Min K; Petzold, Linda R; Niemi, Jarad

2012-01-01T23:59:59.000Z

63

The Hybrid Maximum Principle is a consequence of Pontryagin ...  

E-Print Network [OSTI]

We give a simple proof of the Maximum Principle for smooth hybrid control sys- ... result in the study of such problems is Hybrid Maximum Principle proved in [4] ...

2006-10-31T23:59:59.000Z

64

Predictor Variables of the Maximum Radar Echo Activity on Convective Days  

Science Journals Connector (OSTI)

Digital radar data and atmospheric sounding information were analyzed with the intention of beginning a search for atmospheric parameters which are easily attainable, are independent of whether or not clouds are seeded, and either individually or ...

Gerard E. Klazura; Robert G. Pritchard

1980-03-01T23:59:59.000Z

65

Diffusion maximum as a function of size in dense liquids  

Science Journals Connector (OSTI)

We study the diffusion of small guest particles of different sizes in a host fluid at liquid densities using molecular dynamics simulations. We observe an enhancement of the diffusivity of guest particles for a size related to the structure of the void space of the host fluid, analogous to the “levitation effect” observed for guest diffusion in porous solids. Friction and activation energy are found to be minimum for the guest size with maximum self-diffusivity. Wavelength dependent self-diffusivity indicates a monotonic and oscillatory dependence on wave number k for anomalous and linear regimes, respectively. These are associated with single and bi-exponential decay of the incoherent intermediate scattering function.

Pradip Kr. Ghorai; A. V. Anil Kumar; Srikanth Sastry; S. Yashonath

2005-09-16T23:59:59.000Z

66

Monthly and Annual Maximum Temperatures - Hanford Site  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Station Real Time Met Data from Around the Site Current HMS Observations Daily HMS Extremes in Met Data Met and Climate Data Summary Products Historical Weather Charts Contacts...

67

Maximum mass of magnetic white dwarfs  

E-Print Network [OSTI]

We revisit in this work the problem of the maximum masses of magnetized White Dwarfs (WD). The impact of a strong magnetic field onto the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic field and split into a parallel and perpendicular components. We first construct stable solutions of TOV equations for the parallel pressures, and found that physical solutions vanish for the perpendicular pressure when $B \\gtrsim 10^{13}$ G. This fact establishes an upper bound for a magnetic field and the stability of the configurations in the (quasi) spherical approximation. Our findings also indicate that it is not possible to obtain stable magnetized WD with super Chandrasekhar masses because the values of the magnetic field needed for them are higher than this bound. To proceed into the anisotropic regime, we derived structure equations appropriated for a cylindrical metric with anisotropic pressures. From the solutions of the structure equations in cylindrical symme...

Paret, D Manreza; Horvath, J E

2015-01-01T23:59:59.000Z

68

Critical insulation thickness for maximum entropy generation  

Science Journals Connector (OSTI)

Critical insulation thickness is known to refer to the insulation thickness that maximises the rate of heat transfer in cylindrical and spherical systems. The same analogy is extended to the rate of entropy generation in the present study. The possible critical insulation thickness that yields a maximum rate of entropy generation is investigated. Entropy generation is related to heat transfer through and temperature distribution within the insulation material. It is found that there exists a critical insulation thickness for maximising the rate of entropy generation that is a function of the Bi number and the surface to ambient temperature ratio. The solution of such critical thickness is formulated analytically for both cylindrical and spherical geometries. It is also found that the critical insulation thickness for the rate of entropy generation does not coincide with that for the rate of heat transfer.

Ahmet Z. Sahin

2012-01-01T23:59:59.000Z

69

ROSAT monitoring of persistent giant and rapid variability in the narrow-line Seyfert 1 galaxy IRAS 13224-3809  

E-Print Network [OSTI]

We report evidence for persistent giant and rapid X-ray variability in the radio-quiet, ultrasoft, strong Fe II, narrow-line Seyfert 1 galaxy IRAS 13224-3809. Within a 30 day ROSAT High Resolution Imager (HRI) monitoring observation at least five giant amplitude count rate variations are visible, with the maximum observed amplitude of variability being about a factor of 60. We detect a rise by a factor of about 57 in just two days. IRAS 13224-3809 appears to be the most X-ray variable Seyfert known, and its variability is probably nonlinear. We carefully check the identification of the highly variable X-ray source with the distant galaxy, and it appears to be secure. We examine possible explanations for the giant variability. Unusually strong relativistic effects and partial covering by occulting structures on an accretion disc can provide plausible explanations of the X-ray data, and we explore these two scenarios. Relativistic boosting effects may be relevant to understanding the strong X-ray variability of some steep spectrum Seyferts more generally.

Th. Boller; W. N. Brandt; A. C. Fabian; H. H. Fink

1997-03-18T23:59:59.000Z

70

Maximum likelihood continuity mapping for fraud detection  

SciTech Connect (OSTI)

The author describes a novel time-series analysis technique called maximum likelihood continuity mapping (MALCOM), and focuses on one application of MALCOM: detecting fraud in medical insurance claims. Given a training data set composed of typical sequences, MALCOM creates a stochastic model of sequence generation, called a continuity map (CM). A CM maximizes the probability of sequences in the training set given the model constraints, CMs can be used to estimate the likelihood of sequences not found in the training set, enabling anomaly detection and sequence prediction--important aspects of data mining. Since MALCOM can be used on sequences of categorical data (e.g., sequences of words) as well as real valued data, MALCOM is also a potential replacement for database search tools such as N-gram analysis. In a recent experiment, MALCOM was used to evaluate the likelihood of patient medical histories, where ``medical history`` is used to mean the sequence of medical procedures performed on a patient. Physicians whose patients had anomalous medical histories (according to MALCOM) were evaluated for fraud by an independent agency. Of the small sample (12 physicians) that has been evaluated, 92% have been determined fraudulent or abusive. Despite the small sample, these results are encouraging.

Hogden, J.

1997-05-01T23:59:59.000Z

71

Interval analysis applied to the maximum loading point of electric power systems considering load data uncertainties  

Science Journals Connector (OSTI)

Abstract This paper proposes a simple and efficient power flow method to calculate, in an interval manner, the main variables corresponding to the maximum loading point, under load data uncertainties. The resulting interval nonlinear system of equations is solved using Krawczyk method. The proposed methodology is implemented in the Matlab environment using the Intlab toolbox. Results are compared with those obtainable by Monte Carlo simulations. IEEE 30 bus system and a South-southeastern Brazilian network are used to validate the proposed methodology.

L.E.S. Pereira; V.M. da Costa

2014-01-01T23:59:59.000Z

72

Maximum Likelihood Analysis of Low Energy CDMS II Germanium Data  

E-Print Network [OSTI]

We report on the results of a search for a Weakly Interacting Massive Particle (WIMP) signal in low-energy data of the Cryogenic Dark Matter Search (CDMS~II) experiment using a maximum likelihood analysis. A background model is constructed using GEANT4 to simulate the surface-event background from $^{210}$Pb decay-chain events, while using independent calibration data to model the gamma background. Fitting this background model to the data results in no statistically significant WIMP component. In addition, we perform fits using an analytic ad hoc background model proposed by Collar and Fields, who claimed to find a large excess of signal-like events in our data. We confirm the strong preference for a signal hypothesis in their analysis under these assumptions, but excesses are observed in both single- and multiple-scatter events, which implies the signal is not caused by WIMPs, but rather reflects the inadequacy of their background model.

Agnese, R; Balakishiyeva, D; Thakur, R Basu; Bauer, D A; Billard, J; Borgland, A; Bowles, M A; Brandt, D; Brink, P L; Bunker, R; Cabrera, B; Caldwell, D O; Cerdeno, D G; Chagani, H; Chen, Y; Cooley, J; Cornell, B; Crewdson, C H; Cushman, P; Daal, M; Di Stefano, P C F; Doughty, T; Esteban, L; Fallows, S; Figueroa-Feliciano, E; Fritts, M; Godfrey, G L; Golwala, S R; Graham, M; Hall, J; Harris, H R; Hertel, S A; Hofer, T; Holmgren, D; Hsu, L; Huber, M E; Jastram, A; Kamaev, O; Kara, B; Kelsey, M H; Kennedy, A; Kiveni, M; Koch, K; Leder, A; Loer, B; Asamar, E Lopez; Mahapatra, R; Mandic, V; Martinez, C; McCarthy, K A; Mirabolfathi, N; Moffatt, R A; Moore, D C; Nelson, R H; Oser, S M; Page, K; Page, W A; Partridge, R; Pepin, M; Phipps, A; Prasad, K; Pyle, M; Qiu, H; Rau, W; Redl, P; Reisetter, A; Ricci, Y; Rogers, H E; Saab, T; Sadoulet, B; Sander, J; Schneck, K; Schnee, R W; Scorza, S; Serfass, B; Shank, B; Speller, D; Upadhyayula, S; Villano, A N; Welliver, B; Wright, D H; Yellin, S; Yen, J J; Young, B A; Zhang, J

2014-01-01T23:59:59.000Z

73

ROSAT HRI Monitoring of Extreme X-ray Variability in the Narrow-Line Quasar PHL 1092  

E-Print Network [OSTI]

We report results from an 18-day ROSAT HRI monitoring campaign on the ultrasoft Narrow-Line Seyfert 1 (NLS1) class quasar PHL 1092. This luminous, radio-quiet quasar showed strong X-ray variability in a short ROSAT PSPC observation, and ROSAT HRI monitoring of the similar object IRAS 13224-3809 revealed extreme variability on intermediate timescales. We wanted to determine whether remarkable X-ray variability persistently occurs in PHL 1092, and we also wanted to search for outstanding variability events that constrain emission processes. Given the large luminosity of PHL 1092 (about 5x10^{45} erg/s in the HRI band), we detect extremely rapid and large-amplitude X-ray variability throughout our monitoring. The maximum observed variability amplitude is a factor of about 14, and in the most rapid variability event the HRI count rate increases by a factor of about 3.8 in a rest-frame time interval of 1.3x10^{42} erg/s^2, making it the most extreme such event we are aware of from a radio-quiet quasar. Standard `radiative efficiency limit' arguments imply a radiative efficiency larger than can be achieved by accretion onto a Kerr black hole rotating at the maximum plausible rate, although we point out that such arguments depend upon the geometry of initial radiation release. Relativistic motions of the X-ray source are probably causing the radiative efficiency limit to break down; such relativistic motions have also been inferred in the similar NLS1-class quasar PKS 0558--504.

W. N. Brandt; Th. Boller; A. C. Fabian; M. Ruszkowski

1999-01-25T23:59:59.000Z

74

Comment on "Efficiency of Isothermal Molecular Machines at Maximum Power"  

E-Print Network [OSTI]

Comment on "Efficiency of Isothermal Molecular Machines at Maximum Power" (PRL 108, 210602 (2012), arXiv:1201.6396)

Yunxin Zhang

2012-06-06T23:59:59.000Z

75

What measures climate? A variety of variables including their variability and extreme values determine climate for  

E-Print Network [OSTI]

climate zones? The sun is the ultimate power source for the climate "machine". The uneven distribution conditions. Typical variables to consider are temperature (maximum, miniumum), precipitation (includes rain, sleet, snow, hail, etc), sunlight/cloudiness, wind, humidity, ice cover, sea temperature, etc... Many

Allan, Richard P.

76

Pattern formation, logistics, and maximum path probability  

Science Journals Connector (OSTI)

The concept of pattern formation, which to current researchers is a synonym for self-organization, carries the connotation of deductive logic together with the process of spontaneous inference. Defining a pattern as an equivalence relation on a set of thermodynamic objects, we establish that a large class of irreversible pattern-forming systems, evolving along idealized quasisteady paths, approaches the stable steady state as a mapping upon the formal deductive imperatives of a propositional function calculus. In the preamble the classical reversible thermodynamics of composite systems is analyzed as an externally manipulated system of space partitioning and classification based on ideal enclosures and diaphragms. The diaphragms have discrete classificationcapabilities which are designated in relation to conserved quantities by descriptors such as impervious, diathermal, and adiabatic. Differentiability in the continuum thermodynamic calculus is invoked as equivalent to analyticity and consistency in the underlying class or sentential calculus. The seat of inference, however, rests with the thermodynamicist. In the transition to an irreversible pattern-forming system the defined nature of the composite reservoirs remains, but a given diaphragm is replaced by a pattern-forming system which by its nature is a spontaneously evolving volume partitioner and classifier of invariants. The seat of volition or inference for the classification system is thus transferred from the experimenter or theoretician to the diaphragm, and with it the full deductive facility. The equivalence relations or partitions associated with the emerging patterns may thus be associated with theorems of the natural pattern-forming calculus. The entropyfunction, together with its derivatives, is the vehicle which relates the logistics of reservoirs and diaphragms to the analog logistics of the continuum. Maximum path probability or second-order differentiability of the entropy in isolation are sufficiently strong interpretations of the second law of thermodynamics to define the approach to and the nature of patterned stable steady states. For many pattern-forming systems these principles define quantifiable stable states as maxima or minima (or both) in the dissipation. An elementary statistical-mechanical proof is offered. To turn the argument full circle, the transformations of the partitions and classes which are predicated upon such minimax entropic paths can through digital modeling be directly identified with the syntactic and inferential elements of deductive logic. It follows therefore that all self-organizing or pattern-forming systems which possess stable steady states approach these states according to the imperatives of formal logic, the optimum pattern with its rich endowment ofequivalence relations representing the central theorem of the associated calculus. Logic is thus ‘‘the stuff of the universe,’’ and biological evolution with its culmination in the human brain is the most significant example of all the irreversible pattern-forming processes. We thus conclude with a few remarks on the relevance of the contribution to the theory of evolution and to research on artificial intelligence.

J. S. Kirkaldy

1985-05-01T23:59:59.000Z

77

Vehicle Technologies Office: Fact #410: February 6, 2006 Maximum Speed  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

0: February 6, 0: February 6, 2006 Maximum Speed Limits by State, 2005 to someone by E-mail Share Vehicle Technologies Office: Fact #410: February 6, 2006 Maximum Speed Limits by State, 2005 on Facebook Tweet about Vehicle Technologies Office: Fact #410: February 6, 2006 Maximum Speed Limits by State, 2005 on Twitter Bookmark Vehicle Technologies Office: Fact #410: February 6, 2006 Maximum Speed Limits by State, 2005 on Google Bookmark Vehicle Technologies Office: Fact #410: February 6, 2006 Maximum Speed Limits by State, 2005 on Delicious Rank Vehicle Technologies Office: Fact #410: February 6, 2006 Maximum Speed Limits by State, 2005 on Digg Find More places to share Vehicle Technologies Office: Fact #410: February 6, 2006 Maximum Speed Limits by State, 2005 on AddThis.com...

78

On the "viscosity maximum" during the uniaxial extension of a low density polyethylene  

E-Print Network [OSTI]

An experimental investigation of the viscosity overshoot phenomenon observed during uniaxial extension of a low density polyethylene is pre- sented. For this purpose, traditional integral viscosity measurements on a Muenstedt type extensional rheometer are combined with local mea- surements based on the in-situ visualization of the sample under exten- sion. For elongational experiments at constant strain rates within a wide range of Weissenberg numbers (Wi), three distinct deformation regimes are identified. Corresponding to low values of Wi (regime I), the tensile stress displays a broad maximum. This maximum can be explained by simple mathematical arguments as a result of low deformation rates and it should not be confused with the viscosity overshoot phenomenon. Corre- sponding to intermediate values of Wi (regime II), a local maximum of the integral extensional viscosity is systematically observed. However, within this regime, the local viscosity measurements reveal no maximum, but a plateau. Careful inspection of the images of samples within this regime shows that, corresponding to the maximum of the integral viscosity, sec- ondary necks develop along the sample. The emergence of a maximum of the integral elongational viscosity is thus related to the distinct in- homogeneity of deformation states and is not related to the rheological properties of the material. In the fast stretching limit (high Wi, regime III), the overall geometric uniformity of the sample is well preserved, no secondary necks are observed and both the integral and the local transient elongational viscosity show no maximum. A detailed comparison of the experimental findings with results from literature is presented.

Teodor I. Burghelea; Zdenek Stary; Helmut Muenstedt

2010-01-13T23:59:59.000Z

79

Observed Characteristics of the MJO Relative to Maximum Rainfall JAMES J. BENEDICT AND DAVID A. RANDALL  

E-Print Network [OSTI]

. RANDALL Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado (Manuscript be important (Bladé and Hartmann 1993; Hu and Randall 1994; Kemball-Cook and Weare 2001). Lagged

Randall, David A.

80

Some observations on Goldberg-Trajan's Maximum Flow algorithm on Bipartite Graphs  

E-Print Network [OSTI]

) is a direct graph with two distinguished vertices s (the source) and t (the sink). Each edge [u, v] in G is associated with a positive integer cap(u, v), called the capacity of the edge. If there is no edge from vertex u to vertex v. then we define... cap(u, v) = 0. Intuitively, a flow in a flow network should satisfy the following three conditions: (1) the amount of flow along an edge should not exceed the capacity of the edge (capacity constraint); (2) a flow from a vertex u to a vertex v can...

Yang, Bencai

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Engineer End Uses for Maximum Efficiency | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

for Maximum Efficiency (August 2004) More Documents & Publications Maintaining System Air Quality Compressed Air Storage Strategies Alternative Strategies for Low Pressure End Uses...

82

Maximum Constant Boost Control of the Z-Source Inverter  

E-Print Network [OSTI]

Maximum Constant Boost Control of the Z-Source Inverter Miaosen Shen1 , Jin Wang1 , Alan Joseph1 Laboratory Abstract: This paper proposes two maximum constant boost control methods for the Z-source inverter to modulation index is analyzed in detail and verified by simulation and experiment. Keywords- Z-source inverter

Tolbert, Leon M.

83

Acceleration of Maximum Likelihood Estimation for Tomosynthesis Mammography  

E-Print Network [OSTI]

the amount of x-ray radiation exposure to the patients, tomosynthesis uses a lower dose of x-ray than convenAcceleration of Maximum Likelihood Estimation for Tomosynthesis Mammography Juemin Zhang, Waleed twu2@partners.org Abstract Maximum likelihood (ML) estimation is used dur- ing tomosynthesis

Meleis, Waleed

84

Maximum Residual Energy Routing with Reverse Energy Cost  

E-Print Network [OSTI]

node consumes energy, but the receiving node does not. This assumption is not true if acknowledgementsMaximum Residual Energy Routing with Reverse Energy Cost Qiling Xie, Chin-Tau Lea, Mordecai J-The Maximum Residual Energy Path (MREP) routing has been shown an effective routing scheme for energy

Fleischer, Rudolf

85

A reliable, fast and low cost maximum power point tracker for photovoltaic applications  

SciTech Connect (OSTI)

This work presents a new maximum power point tracker system for photovoltaic applications. The developed system is an analog version of the ''P and O-oriented'' algorithm. It maintains its main advantages: simplicity, reliability and easy practical implementation, and avoids its main disadvantages: inaccurateness and relatively slow response. Additionally, the developed system can be implemented in a practical way at a low cost, which means an added value. The system also shows an excellent behavior for very fast variables in incident radiation levels. (author)

Enrique, J.M.; Andujar, J.M.; Bohorquez, M.A. [Departamento de Ingenieria Electronica, de Sistemas Informaticos y Automatica, Universidad de Huelva (Spain)

2010-01-15T23:59:59.000Z

86

The Galex Ultraviolet Variability (GUVV) Catalog  

E-Print Network [OSTI]

We present Version 1.0 of the NASA Galaxy Evolution Explorer (GALEX) ultraviolet variability catalog (GUVV) that contains information on 84 time-variable and transient sources gained with simultaneous near and far ultraviolet photometric observations. These time-variable sources were serendipitously revealed in the various 1.2 degree star fields currently being surveyed by the GALEX satellite in two ultraviolet bands (NUV 1750-2750A, FUV 1350-1750A) with limiting AB magnitudes of 23-25. The largest-amplitude variable objects presently detected by GALEX are M-dwarf flare stars, which can brighten by 5-10 mag in both the NUV and FUV bands during short duration (< 500s) outbursts. Other types of large-amplitude ultraviolet variable objects include ab-type RR Lyrae stars, which can vary periodically by 2-5mag in the GALEX FUV band. This first GUVV catalog lists galactic positions and possible source identifications in order to provide the astronomical community with a list of time-variable objects that can now be repeatedly observed at other wavelengths. We expect the total number of time-variable source detections to increase as the GALEX mission progresses, such that later version numbers of the GUVV catalog will contain substantially more variable sources.

Barry Y. Welsh; Jonathan M. Wheatley; Kenneth Heafield; Mark Seibert; Stanley E. Browne; Samir Salim; R. Michael Rich; Tom A. Barlow; Luciana Bianchi; Yong-Ik Byun; Jose Donas; Karl Forster; Peter G. Friedman; Timothy M. Heckman; Patrick N. Jelinsky; Young-Wook Lee; Barry F. Madore; Roger F. Malina; D. Christopher Martin; Bruno Milliard; Patrick Morrissey; Susan G. Neff; David Schiminovich; Oswald H. W. Siegmund; Todd Small; Alex S. Szalay; Ted K. Wyder

2005-04-21T23:59:59.000Z

87

A review of maximum power point tracking algorithms for wind energy systems  

Science Journals Connector (OSTI)

This paper reviews state of the art maximum power point tracking (MPPT) algorithms for wind energy systems. Due to the instantaneous changing nature of the wind, it is desirable to determine the one optimal generator speed that ensures maximum energy yield. Therefore, it is essential to include a controller that can track the maximum peak regardless of wind speed. The available MPPT algorithms can be classified as either with or without sensors, as well as according to the techniques used to locate the maximum peak. A comparison has been made between the performance of different MPPT algorithms on the basis of various speed responses and ability to achieve the maximum energy yield. Based on simulation results available in the literature, the optimal torque control (OTC) has been found to be the best MPPT method for wind energy systems due to its simplicity. On the other hand, the perturbation and observation (P&O) method is flexible and simple in implementation, but is less efficient and has difficulties determining the optimum step-size.

M.A. Abdullah; A.H.M. Yatim; C.W. Tan; R. Saidur

2012-01-01T23:59:59.000Z

88

Maximum Photovoltaic Penetration Levels on Typical Distribution Feeders: Preprint  

SciTech Connect (OSTI)

This paper presents simulation results for a taxonomy of typical distribution feeders with various levels of photovoltaic (PV) penetration. For each of the 16 feeders simulated, the maximum PV penetration that did not result in steady-state voltage or current violation is presented for several PV location scenarios: clustered near the feeder source, clustered near the midpoint of the feeder, clustered near the end of the feeder, randomly located, and evenly distributed. In addition, the maximum level of PV is presented for single, large PV systems at each location. Maximum PV penetration was determined by requiring that feeder voltages stay within ANSI Range A and that feeder currents stay within the ranges determined by overcurrent protection devices. Simulations were run in GridLAB-D using hourly time steps over a year with randomized load profiles based on utility data and typical meteorological year weather data. For 86% of the cases simulated, maximum PV penetration was at least 30% of peak load.

Hoke, A.; Butler, R.; Hambrick, J.; Kroposki, B.

2012-07-01T23:59:59.000Z

89

On the maximum pressure rise rate in boosted HCCI operation  

E-Print Network [OSTI]

This paper explores the combined effects of boosting, intake air temperature, trapped residual gas fraction, and dilution on the Maximum Pressure Rise Rate (MPRR) in a boosted single cylinder gasoline HCCI engine with ...

Wildman, Craig B.

90

Nonstationary analysis of annual maximum streamflow of Canada  

Science Journals Connector (OSTI)

Both natural climate change and anthropogenic impacts may cause nonstationarities in hydrological extremes. In this study, long-term annual maximum streamflow (AMS) records from 145 stations over Canada were used to investigate the nonstationary ...

Xuezhi Tan; Thian Yew Gan

91

Propane spectral resolution enhancement by the maximum entropy method  

Science Journals Connector (OSTI)

The Burg algorithm for maximum entropy power spectral density estimation is applied to a time series of data obtained from a Michelson interferometer and compared with a standard fast...

Bonavito, N L; Yeh, K C; Stewart, K P; Inguva, R; Hurley, E J

1990-01-01T23:59:59.000Z

92

Efficiency at maximum power of interacting molecular machines  

E-Print Network [OSTI]

We investigate the efficiency of systems of molecular motors operating at maximum power. We consider two models of kinesin motors on a microtubule: for both the simplified and the detailed model, we find that the many-body exclusion effect enhances the efficiency at maximum power of the many-motor system, with respect to the single motor case. Remarkably, we find that this effect occurs in a limited region of the system parameters, compatible with the biologically relevant range.

N. Golubeva; A. Imparato

2012-10-22T23:59:59.000Z

93

Field observations of soil moisture variability across scales  

E-Print Network [OSTI]

campaigns were conducted in Oklahoma and Iowa in the centralUSA. The Oklahoma study region is sub-humid with moderatelyUSA South Dakota, USA Oklahoma, USA Kansas, USA Texas, USA

Famiglietti, James S; Ryu, Dongryeol; Berg, Aaron A; Rodell, Matthew; Jackson, Thomas J

2008-01-01T23:59:59.000Z

94

REGIONAL VARIABILITY IN TROPICAL CONVECTION: OBSERVATIONS FROM TRMM  

E-Print Network [OSTI]

and longitude. The reflectivity histograms and ice water contents were then combined with LIS lightning flash structure histograms, and lightning flash density data reveal that 1) relative to tropical continental characteristics of precipitation vertical structure and associated lightning flash density. In general

Rutledge, Steven

95

Observed Global Precipitation Variability During the 20th Century  

E-Print Network [OSTI]

of warming and other regional-scale features, including changes in wind patterns, precipitation and some aspects of extremes and of ice. n The models used in AR4 were judged to have improved representation

Anisimov, Mikhail

96

Variable Frequency Drives  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

How BPA Supports VFDs Rebates are available from your utility for Variable Frequency Drives on pumps 20hp or greater and storage fans.. Energy savings from VFDs vary and can...

97

14 Applications of the Maximum Principle We discuss the terminal conditions of the maximum principle and further examples of  

E-Print Network [OSTI]

by the variable t. We then have the augmented variables x x t a a 1 0 . We keep the same definition (13.2 Example: monopolist Miss Prout holds the entire remaining stock of Cambridge elderberry wine for the vintage year 1959. If she releases it at rate u (in continuous time) she realises a unit price p(u) = (1

Weber, Richard

98

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

Open Energy Info (EERE)

Property Property Edit with form History Facebook icon Twitter icon » Property:Maximum Wave Height(m) Jump to: navigation, search Property Name Maximum Wave Height(m) Property Type String Pages using the property "Maximum Wave Height(m)" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft Wave Flume Facility + 0.2 + 10-ft Wave Flume Facility + 0.5 + 11-ft Wave Flume Facility + 0.4 + 2 2-ft Flume Facility + 0.6 + 3 3-ft Wave Flume Facility + 0.2 + 5 5-ft Wave Flume Facility + 0.5 + 6 6-ft Wave Flume Facility + 0.4 + A Alden Large Flume + 0.0 + Alden Small Flume + 0.2 + Alden Wave Basin + 0.3 + B Breakwater Research Facility + 0.0 + C Carderock Maneuvering & Seakeeping Basin + 0.6 + Carderock Tow Tank 2 + 0.6 + Carderock Tow Tank 3 + 0.6 +

99

Efficiency of autonomous soft nano-machines at maximum power  

E-Print Network [OSTI]

We consider nano-sized artificial or biological machines working in steady state enforced by imposing non-equilibrium concentrations of solutes or by applying external forces, torques or electric fields. For unicyclic and strongly coupled multicyclic machines, efficiency at maximum power is not bounded by the linear response value 1/2. For strong driving, it can even approach the thermodynamic limit 1. Quite generally, such machines fall in three different classes characterized, respectively, as "strong and efficient", "strong and inefficient", and "balanced". For weakly coupled multicyclic machines, efficiency at maximum power has lost any universality even in the linear response regime.

Udo Seifert

2010-11-11T23:59:59.000Z

100

Macroscopic observables  

SciTech Connect (OSTI)

We study macroscopic observables defined as the total value of a physical quantity over a collection of quantum systems. We show that previous results obtained for an infinite ensemble of identically prepared systems lead to incorrect conclusions for finite ensembles. In particular, exact measurement of a macroscopic observable significantly disturbs the state of any finite ensemble. However, we show how this disturbance can be made arbitrarily small when the measurements are of finite accuracy. We demonstrate a general trade-off between state disturbance and measurement coarseness as a function of the size of the ensemble. Using this trade-off, we show that the histories generated by any sequence of finite accuracy macroscopic measurements always generate a consistent family in the absence of large-scale entanglement for sufficiently large ensembles. Hence, macroscopic observables behave 'classically' provided that their accuracy is coarser than the quantum correlation length scale of the system. The role of these observable is also discussed in the context of NMR quantum information processing and bulk ensemble quantum state tomography.

Poulin, David [Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2L 2Y5 (Canada); Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2005-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Macroscopic observables  

Science Journals Connector (OSTI)

We study macroscopic observables defined as the total value of a physical quantity over a collection of quantum systems. We show that previous results obtained for an infinite ensemble of identically prepared systems lead to incorrect conclusions for finite ensembles. In particular, exact measurement of a macroscopic observable significantly disturbs the state of any finite ensemble. However, we show how this disturbance can be made arbitrarily small when the measurements are of finite accuracy. We demonstrate a general trade-off between state disturbance and measurement coarseness as a function of the size of the ensemble. Using this trade-off, we show that the histories generated by any sequence of finite accuracy macroscopic measurements always generate a consistent family in the absence of large-scale entanglement for sufficiently large ensembles. Hence, macroscopic observables behave “classically” provided that their accuracy is coarser than the quantum correlation length scale of the system. The role of these observable is also discussed in the context of NMR quantum information processing and bulk ensemble quantum state tomography.

David Poulin

2005-02-07T23:59:59.000Z

102

Performance of Civil Aviation Receivers during Maximum Solar Activity Events  

E-Print Network [OSTI]

Performance of Civil Aviation Receivers during Maximum Solar Activity Events Lina DEAMBROGIO on the fields of ionosphere scintillations, solar energetic particles and on the implementation of operational the upcoming period of high solar activity. Emilien ROBERT got his PhD in 2005 and started to work on behalf

Boyer, Edmond

103

Rapidly Solving an Online Sequence of Maximum Flow Problems  

E-Print Network [OSTI]

... an interdictor allocates a finite amount of resources to remove arcs from a net- ... is, the next maximum flow problem in the sequence differs from the previous one by ..... the appropriate reoptimization case and then taking the appropriate action to ..... Our first set of computational experiments tested the performance of our ...

2008-02-29T23:59:59.000Z

104

THE MAXIMUM CAPACITY OF A LINE PLAN IS INAPPROXIMABLE  

E-Print Network [OSTI]

THE MAXIMUM CAPACITY OF A LINE PLAN IS INAPPROXIMABLE CHRISTINA PUHL AND SEBASTIAN STILLER Abstract a network, upper arc-capacities and a line pool. E-mail: puhl@math.tu-berlin.de, stiller of the European Commission under contract no. FP6-021235-2. 1 #12;2 CHRISTINA PUHL AND SEBASTIAN STILLER We

Nabben, Reinhard

105

Maximum-principle-satisfying and positivity-preserving high order ...  

E-Print Network [OSTI]

conservation laws: Survey and new developments ..... Notice that in (2.10) we need to evaluate the maximum/minimum of a ..... total energy, p is the pressure, e is the internal energy, and ? > 1 is a constant ... under a standard CFL condition.

2011-04-01T23:59:59.000Z

106

Maximum Entropy in Support of Semantically Annotated Datasets  

E-Print Network [OSTI]

Maximum Entropy in Support of Semantically Annotated Datasets Paulo Pinheiro da Silva, Vladik whether two datasets describe the same quantity. The existing solution to this problem is to use these datasets' ontologies to deduce that these datasets indeed represent the same quantity. However, even when

Kreinovich, Vladik

107

O(1)-Approximations for Maximum Movement Piotr Berman1  

E-Print Network [OSTI]

movement of the pebbles, motivated by minimizing either execution time or energy usage. Spe- cific problems the maximum movement made by pebbles on a graph to reach a configuration in which the pebbles form a connected. For example, in the connectivity goal, the proximity of the robots should form a connected graph. Two

Demaine, Erik

108

Maximization of Recursive Utilities: A Dynamic Maximum Principle Approach  

E-Print Network [OSTI]

Maximization of Recursive Utilities: A Dynamic Maximum Principle Approach Wahid FAIDI LAMSIN, ENIT for a class of robust utility function introduced in Bordigoni, Matoussi et Schweizer (2005). Our method-investment strategy which is characterized as the unique solution of a forward-backward system. Key words : Utility

Di Girolami, Cristina

109

Renewable Energy Scheduling for Fading Channels with Maximum Power Constraint  

E-Print Network [OSTI]

Renewable Energy Scheduling for Fading Channels with Maximum Power Constraint Zhe Wang Electrical--In this paper, we develop efficient algorithm to obtain the optimal energy schedule for fading channel with energy harvesting. We assume that the side information of both the channel states and energy harvesting

Greenberg, Albert

110

Variable Frequency Pump Drives  

E-Print Network [OSTI]

-frequency electric motor drive. What is happenin9 with variable frequency driven pun,ps is a classical illustration that evolution in technical products takes place not only because of changes in the processes served by these products, or because of innovations...-pole 3550 rpm squirrel caqe induction motor became available in the early 1930s that high pressure pumps operating at that speed could be buil t. And now, in the 1980s, the development of the solid-state, variable frequency electric motor drive...

Karassik, I. J.; Petraccaro, L. L.; McGuire, J. T.

111

Minisuperspaces: Observables and Quantization  

E-Print Network [OSTI]

A canonical transformation is performed on the phase space of a number of homogeneous cosmologies to simplify the form of the scalar (or, Hamiltonian) constraint. Using the new canonical coordinates, it is then easy to obtain explicit expressions of Dirac observables, i.e.\\ phase space functions which commute weakly with the constraint. This, in turn, enables us to carry out a general quantization program to completion. We are also able to address the issue of time through ``deparametrization'' and discuss physical questions such as the fate of initial singularities in the quantum theory. We find that they persist in the quantum theory {\\it inspite of the fact that the evolution is implemented by a 1-parameter family of unitary transformations}. Finally, certain of these models admit conditional symmetries which are explicit already prior to the canonical transformation. These can be used to pass to quantum theory following an independent avenue. The two quantum theories --based, respectively, on Dirac observables in the new canonical variables and conditional symmetries in the original ADM variables-- are compared and shown to be equivalent.

Abhay Ashtekar; Ranjeet S. Tate; Claes Uggla

1993-02-21T23:59:59.000Z

112

Total Solar Irradiance Variability and the Solar Activity Cycle  

E-Print Network [OSTI]

It is suggested that the solar variability is due to the perturbed nature of the solar core and this variability is provided by the variability of the solar neutrino flux from the solar neutrino detectors i.e., Homestake, Superkamiokande, SAGE and GALLEX-GNO. The solar neutrino flux in the standard solar model (SSM) was calculated on the assumption of L_nu (neutrino luminosity) = L_gamma (optical luminosity) which implies that if there is a change in optical luminosity then solar neutrino flux data will also be changed. An internal dynamo due to the cyclic variation of nuclear energy generation inside the core of the sun is responsible for the solar activity cycle was suggested and thus the internal magnetic field is also variable. Again the changes in the nuclear energy generation induce structural changes that result in variations of the global solar parameters i.e., luminosity, radius and temperatures etc. From the analysis of total solar irradiance (TSI) data during the year from 1970 to 2003 we have found five phases within the solar activity cycle. The first phase (I) starts before two years from the sunspot minimum. The second phase (II) starts at the time of sunspot minimum and phase (III) starts before 2/3 years from sunspot maximum whereas phase (IV) starts at sunspot maximum and fifth phase (V) starts at after 2-3 years from sunspot maximum.

Probhas Raychaudhuri

2006-05-06T23:59:59.000Z

113

Property:Maximum Velocity(m/s) | Open Energy Information  

Open Energy Info (EERE)

Velocity(m/s) Velocity(m/s) Jump to: navigation, search Property Name Maximum Velocity(m/s) Property Type String Pages using the property "Maximum Velocity(m/s)" Showing 25 pages using this property. (previous 25) (next 25) A Alden Large Flume + 0.9 + B Bucknell Hydraulic Flume + 2.7 + C Carderock Maneuvering & Seakeeping Basin + 7.2 + Carderock Rotating Arm Tow Tank + 25.8 + Carderock Tow Tank 1 + 9.3 + Carderock Tow Tank 2 + 10.3 + Carderock Tow Tank 3 + 25.8 + Chase Tow Tank + 2.5 + D Davidson Laboratory Tow Tank + 18.3 + H Haynes Tow Tank + 1.8 + I Ice Towing Tank + 0.5 + L Lakefront Tow Tank + 2.7 + M MHL Free Surface Channel + 2 + MHL High Speed Cavitation + 25.9 + MHL Tow Tank + 6.7 + MIT Tow Tank + 1.5 + MMA Tugboat/ Barge/ Vessel + 5.1 + Maine Tow Tank + 3 +

114

Radiative muon capture rates and the maximum photon energy  

Science Journals Connector (OSTI)

The differential photon spectrum for radiative muon capture is expanded about the average maximum photon energy km and the correction terms evaluated using for one a modified Thomas-Reiche-Kuhn sum rule, thus extending previous work for ordinary capture. The resulting rate is much less dependent on km than the usual closure result. The ratio km? appropriate for closure calculations, with ? the average neutrino energy, is determined and found to be approximately constant and, when correction terms are included, somewhat higher than values previously used. By similar techniques a consistency relation is derived which can be solved to explicitly estimate "physical" values of km and ?.NUCLEAR REACTIONS Radiative muon capture. Differential photon spectrum, relative rate for Ca40. Dipole sum rules used to correct closure approximation, obtain estimates of mean excitation energy, average maximum photon energy.

R. S. Sloboda and Harold W. Fearing

1978-11-01T23:59:59.000Z

115

When are microcircuits well-modeled by maximum entropy methods?  

E-Print Network [OSTI]

and fire. The inputs are chosen from distributions that are either gaussian, uniform, skewed, or bimodal. For each circuit, we compute the distribution on output spiking states either analytically or by sampling, approximate by a maximum entropy fit... generation is characterized by a simple static nonlinearity, or by integrate-and-fire (LIF) threshold-crossing dynamics. However, this circuit does generate substantial higher-order correlations if the common input to the three cells is bimodal. This approach...

2010-07-20T23:59:59.000Z

116

Maximum Entry and Mandatory Separation Ages for Certain Security Employees  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The policy establishes the DOE policy on maximum entry and mandatory separation ages for primary or secondary positions covered under special statutory retirement provisions and for those employees whose primary duties are the protection of officials of the United States against threats to personal safety or the investigation, apprehension, and detention of individuals suspected or convicted of offenses against the criminal laws of the United States. Admin Chg 1, dated 12-1-11, cancels DOE P 310.1.

2001-10-11T23:59:59.000Z

117

The Maximum Patch Method for Directional Dark Matter Detection  

E-Print Network [OSTI]

Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.

Shawn Henderson; Jocelyn Monroe; Peter Fisher

2008-01-10T23:59:59.000Z

118

Maximum patch method for directional dark matter detection  

SciTech Connect (OSTI)

Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.

Henderson, Shawn; Monroe, Jocelyn; Fisher, Peter [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Laboratory for Nuclear Science, MIT Kavli Institute for Astrophysics and Space Research, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2008-07-01T23:59:59.000Z

119

Long-term spectroscopic monitoring of the Luminous Blue Variable HD160529  

E-Print Network [OSTI]

We have spectroscopically monitored the galactic Luminous Blue Variable HD 160529 and obtained an extensive high-resolution data set that covers the years 1991 to 2002. During this period, the star evolved from an extended photometric minimum phase towards a new visual maximum. In several observing seasons, we covered up to four months with almost daily spectra. Our spectra typically cover most of the visual spectral range with a high spectral resolution (about 20,000 or more). This allows us to investigate the variability in many lines and on many time scales from days to years. We find a correlation between the photospheric HeI lines and the brightness of the star, both on a time scale of months and on a time scale of years. The short-term variations are smaller and do not follow the long-term trend, strongly suggesting different physical mechanisms. Metal lines also show both short-term and long-term variations in strength and also a long-term trend in radial velocity. Most of the line-profile variations can be attributed to changing strengths of lines. Propagating features in the line profiles are rarely observed. We find that the mass-loss rate of HD 160529 is almost independent of temperature, i.e. visual brightness.

Otmar Stahl; Thomas Gaeng; Chris Sterken; Andreas Kaufer; Thomas Rivinius; Thomas Szeifert; Bernhard Wolf

2002-12-20T23:59:59.000Z

120

IEP - Water-Energy Interface: Total Maximum Daily Load Page  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Total Maximum Daily Loads (TMDLs) Total Maximum Daily Loads (TMDLs) The overall goal of the Clean Water Act is to "restore and maintain the chemical, physical, and biological integrity of the NationÂ’s waters." In 1999, EPA proposed changes to Section 303(d), to establish Total Maximum Daily Loads (TMDLs) for watersheds that do not meet this goal. The TMDL is the highest amount of a given pollutant that is permissible in that body of water over a given period of time. TMDLs include both waste load allocation (WLA) for point sources and load allocations for non-point sources. In Appalachia, acid mine drainage (AMD) is the single most damaging non-point source. There is also particular concern of the atmospheric deposition of airborne sulfur, nitrogen, and mercury compounds. States are currently in the process of developing comprehensive lists of impaired waters and establishing TMDLs for those waters. EPA has recently proposed a final rule that will require states to develop TMDLs and implement plans for improving water quality within the next 10 years. Under the new rule, TMDL credits could be traded within a watershed.

Note: This page contains sample records for the topic "maximum variable observations" 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

Facets for the Maximum Common Induced Subgraph Problem ...  

E-Print Network [OSTI]

such that (i, j) ? E ? (?(i),?(j)) ? F and (i, j) ? F ? (??1(i),??1(j)) ? E. Besides, given a graph G ... therefore, there are n + 1 afine independent vectors (where n is the number of variables in the model). ...... [4] M. R. Garey and D. S. Johnson.

2011-09-02T23:59:59.000Z

122

INTEGRAL observations of SS433: Results of coordinated campaign  

E-Print Network [OSTI]

Results of simultaneous INTEGRAL and optical observations of galactic microquasar SS433 in May 2003 and INTEGRAL/RXTE observations in March 2004 are presented. Persistent precessional variability with a maximum to minimum uneclipsed hard X-ray flux ratio of \\sim 4 is discovered. The 18-60 keV X-ray eclipse is found to be in phase with optical and near infrared eclipses. The orbital eclipse observed by INTEGRAL in May 2003 is at least two times deeper and apparently wider than in soft X-ray band. The broadband X-ray spectrum 2-100 keV simultaneously detected by RXTE/INTEGRAL in March 2004 can be described by bremsstrahlung emission from optically thin thermal plasma with kT\\sim 30 keV. The optical spectroscopy with the 6-m SAO BTA telescope confirmed the optical companion to be an A5-A7 supergiant. For the first time, spectorscopic indications of a strong heating effect in the optical star atmosphere are found. The measurements of absorption lines which are presumably formed in the non-illuminated side of the ...

Cherepashchuk, A M; Fabrika, S N; Postnov, K A; Molkov, S V; Barsukova, E A; Antokhina, E A; Irsmambetova, T R; Panchenko, I E; Seifina, E V; Shakura, N I; Timokhin, A N; Bikmaev, I F; Sakhibullin, N A; Aslan, Z; Khamitov, I; Pramsky, A G; Sholukhova, O; Gnedin, Y N; Arkharov, A A; Larionov, V M; Gnedin, Yu.N.

2005-01-01T23:59:59.000Z

123

Interpretation of the depths of maximum of extensive air showers measured by the Pierre Auger Observatory  

SciTech Connect (OSTI)

To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the ln A distribution. We examine the goodness of this simple method through simulations of test mass distributions. The application of the parameterization to Pierre Auger Observatory data allows one to study the energy dependence of the mean ln A and of its variance under the assumption of selected hadronic interaction models. We discuss possible implications of these dependences in term of interaction models and astrophysical cosmic ray sources.

Collaboration: Pierre Auger Collaboration

2013-02-01T23:59:59.000Z

124

Variable depth core sampler  

DOE Patents [OSTI]

A variable depth core sampler apparatus comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member.

Bourgeois, Peter M. (Hamburg, NY); Reger, Robert J. (Grand Island, NY)

1996-01-01T23:59:59.000Z

125

Variable laser attenuator  

DOE Patents [OSTI]

The disclosure relates to low loss, high power variable attenuators comprising one or more transmissive and/or reflective multilayer dielectric filters. The attenuator is particularly suitable to use with unpolarized lasers such as excimer lasers. Beam attenuation is a function of beam polarization and the angle of incidence between the beam and the filter and is controlled by adjusting the angle of incidence the beam makes to the filter or filters. Filters are selected in accordance with beam wavelength. 9 figs.

Foltyn, S.R.

1987-05-29T23:59:59.000Z

126

Variable depth core sampler  

DOE Patents [OSTI]

A variable depth core sampler apparatus is described comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member. 7 figs.

Bourgeois, P.M.; Reger, R.J.

1996-02-20T23:59:59.000Z

127

On the realization of Bell observables  

E-Print Network [OSTI]

We show how Bell observables on a bipartite quantum system can be obtained by local observables via a controlled-unitary transformation. For continuous variables this result holds for the Bell observable corresponding to the non-conventional heterodyne measurement on two radiation modes, which is connected through a 50-50 beam-splitter to two local observables given by single-mode homodyne measurements. A simple scheme for a controlled-unitary transformation of continuous variables is also presented, which needs only two squeezers, a parametric downconverter and two beam splitters.

Giacomo Mauro D'Ariano; Paolo Perinotti

2004-06-11T23:59:59.000Z

128

A variable-field permanent-magnet dipole for accelerators  

SciTech Connect (OSTI)

A new concept for a variable-field permanent-magnet dipole has been developed and fabricated at Los Alamos. The application requires an extremely uniform dipole field in the magnet aperture and precision variability over a large operating range. An iron-core permanent- magnet design using a shunt that was specially shaped to vary the field in a precise and reproducible fashion with shunt position. The key to this design is in the shape of the shunt. The field as a function of shunt position is very linear from 90% of the maximum field to 20% of the minimum field. The shaped shunt also results in a small maximum magnetic force attracting the shunt to the yoke allowing a simple mechanical design. Calculated and measured results agree well for the magnet.

Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.

1992-01-01T23:59:59.000Z

129

A variable-field permanent-magnet dipole for accelerators  

SciTech Connect (OSTI)

A new concept for a variable-field permanent-magnet dipole has been developed and fabricated at Los Alamos. The application requires an extremely uniform dipole field in the magnet aperture and precision variability over a large operating range. An iron-core permanent- magnet design using a shunt that was specially shaped to vary the field in a precise and reproducible fashion with shunt position. The key to this design is in the shape of the shunt. The field as a function of shunt position is very linear from 90% of the maximum field to 20% of the minimum field. The shaped shunt also results in a small maximum magnetic force attracting the shunt to the yoke allowing a simple mechanical design. Calculated and measured results agree well for the magnet.

Kraus, R.H. Jr.; Barlow, D.B.; Meyer, R.

1992-09-01T23:59:59.000Z

130

Understanding Recent Eastern Horn of Africa Rainfall Variability and Change  

Science Journals Connector (OSTI)

Observations and sea surface temperature (SST)-forced ECHAM5 simulations are examined to study the seasonal cycle of eastern Africa rainfall and its SST sensitivity during 1979–2012, focusing on interannual variability and trends. The eastern Horn ...

Brant Liebmann; Martin P. Hoerling; Chris Funk; Ileana Bladé; Randall M. Dole; Dave Allured; Xiaowei Quan; Philip Pegion; Jon K. Eischeid

2014-12-01T23:59:59.000Z

131

Reduction of tropical land region precipitation variability via transpiration  

E-Print Network [OSTI]

Tropical rainforests are known to exhibit low intraseasonal precipitation variability compared with oceanic areas with similar mean precipitation in observations and models. In the present study, the potential role of ...

Lee, Jung-Eun

132

Location of Maximum Credible Beam Losses in LCLS Injector  

SciTech Connect (OSTI)

The memo describes the maximum credible beam the LCLS injector can produce and lose at various locations along the beamline. The estimation procedure is based upon three previous reports [1, 2, 3]. While specific numbers have been updated to accurately reflect the present design parameters, the conclusions are very similar to those given in Ref 1. The source of the maximum credible beam results from the explosive electron emission from the photocathode if the drive laser intensity exceeds the threshold for plasma production. In this event, the gun's RF field can extract a large number of electrons from this plasma which are accelerated out of the gun and into the beamline. This electron emission persists until it has depleted the gun of all its energy. Hence the number of electrons emitted per pulse is limited by the amount of stored RF energy in the gun. It needs to be emphasized that this type of emission is highly undesirable, as it causes permanent damage to the cathode.

Mao, Stan

2010-12-13T23:59:59.000Z

133

Ionization and maximum energy of nuclei in shock acceleration theory  

E-Print Network [OSTI]

We study the acceleration of heavy nuclei at SNR shocks when the process of ionization is taken into account. Heavy atoms ($Z_N >$ few) in the interstellar medium which start the diffusive shock acceleration (DSA) are never fully ionized at the moment of injection. The ionization occurs during the acceleration process, when atoms already move relativistically. For typical environment around SNRs the photo-ionization due to the background galactic radiation dominates over Coulomb collisions. The main consequence of ionization is the reduction of the maximum energy which ions can achieve with respect to the standard result of the DSA. In fact the photo-ionization has a timescale comparable to the beginning of the Sedov-Taylor phase, hence the maximum energy is no more proportional to the nuclear charge, as predicted by standard DSA, but rather to the effective ions' charge during the acceleration process, which is smaller than the total nuclear charge $Z_N$. This result can have a direct consequence in the pred...

Morlino, Giovanni

2011-01-01T23:59:59.000Z

134

Monthly Number of Days for Maximum Temperature - Hanford Site  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Station Real Time Met Data from Around the Site Current HMS Observations Daily HMS Extremes in Met Data Met and Climate Data Summary Products Historical Weather Charts Contacts...

135

PHP: Constructs and Variables Introduction  

E-Print Network [OSTI]

PHP: Constructs and Variables Introduction This document describes: 1. the syntax and types of variables, 2. PHP control structures (i.e., conditionals and loops), 3. mixed-mode processing, 4. how to use one script from within another, 5. how to define and use functions, 6. global variables in PHP, 7

Vander Zanden, Brad

136

Correlated spectral variability in brown dwarfs  

E-Print Network [OSTI]

Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared (0.95-1.64 micron) spectrophotometric monitoring of four field L and T dwarfs spanning timescales of 0.1-5.5 hrs, the goal being to learn more about the physical nature of this variability. Spectra are analysed differentially with respect to a simultaneously observed reference source in order to remove Earth-atmospheric variations. The variability amplitude detected is typically 2-10%, depending on the source and wavelength. I analyse the data for correlated variations between spectral indices. This approach is more robust than single band or chisq analyses, because it does not assume an amplitude for the (often uncertain) noise level (although the significance test still assumes a shape for the noise power spectrum). Three of the four targets show significant evidence for cor...

Bailer-Jones, C A L

2007-01-01T23:59:59.000Z

137

X-ray variability in M87  

E-Print Network [OSTI]

We present the evidence for X-ray variability from the core and from knot A in the M87 jet based on data from two observations with the Einstein Observatory High Resolution Imager (HRI) and three observations with the ROSAT HRI. The core intensity showed a 16% increase in 17 months ('79-'80); a 12% increase in the 3 years '92 to '95; and a 17% drop in the last half of 1995. The intensity of knot A appears to have decreased by 16% between 92Jun and 95Dec. Although the core variability is consistent with general expectations for AGN nuclei, the changes in knot A provide constraints on the x-ray emission process and geometry. Thus we predict that the x-ray morphology of knot A will differ significantly from the radio and optical structure.

D. E. Harris; J. A. Biretta; W. Junor

1996-12-05T23:59:59.000Z

138

Boiler Maximum Achievable Control Technology (MACT) Technical Assistance- Fact Sheet, May 2014  

Broader source: Energy.gov [DOE]

Fact sheet about the Boiler Maximum Achievable Control Technology (MACT) Technical Assistance Program

139

Maximum-Likelihood Continuity Mapping (MALCOM): An Alternative to HMMs  

SciTech Connect (OSTI)

The authors describe Maximum-Likelihood Continuity Mapping (MALCOM) as an alternative to hidden Markov models (HMMs) for processing sequence data such as speech. While HMMs have a discrete ''hidden'' space constrained by a fixed finite-automata architecture, MALCOM has a continuous hidden space (a continuity map) that is constrained only by a smoothness requirement on paths through the space. MALCOM fits into the same probabilistic framework for speech recognition as HMMs, but it represents a far more realistic model of the speech production process. The authors support this claim by generating continuity maps for three speakers and using the resulting MALCOM paths to predict measured speech articulator data. The correlations between the MALCOM paths (obtained from only the speech acoustics) and the actual articulator movements average 0.77 on an independent test set not used to train MALCOM nor the predictor. On average, this unsupervised model achieves 92% of performance obtained using the corresponding supervised method.

Nix, D.A.; Hogden, J.E.

1998-12-01T23:59:59.000Z

140

Maximum Entropy Principle and the Higgs boson mass  

Science Journals Connector (OSTI)

Abstract A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as M H = 125.04 ± 0.25 GeV , a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel within a Higgs portal model.

Alexandre Alves; Alex G. Dias; Roberto da Silva

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Reduction in maximum time uncertainty of paired time signals  

DOE Patents [OSTI]

Reduction in the maximum time uncertainty (t/sub max/ - t/sub min/) of a series of paired time signals t/sub 1/ and t/sub 2/ varying between two input terminals and representative of a series of single events where t/sub 1/ less than or equal to t/sub 2/ and t/sub 1/ + t/sub 2/ equals a constant, is carried out with a circuit utilizing a combination of OR and AND gates as signal selecting means and one or more time delays to increase the minimum value (t/sub min/) of the first signal t/sub 1/ closer to t/sub max/ and thereby reduce the difference. The circuit may utilize a plurality of stages to reduce the uncertainty by factors of 20 to 800.

Theodosiou, G.E.; Dawson, J.W.

1981-02-11T23:59:59.000Z

142

Probable maximum flood control; Yucca Mountain Site Characterization Project  

SciTech Connect (OSTI)

This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility.

DeGabriele, C.E.; Wu, C.L. [Bechtel National, Inc., San Francisco, CA (United States)

1991-11-01T23:59:59.000Z

143

Fracture Toughness and Maximum Stress in a Disordered Lattice System  

E-Print Network [OSTI]

Fracture in a disordered lattice system is studied. In our system, particles are initially arranged on the triangular lattice and each nearest-neighbor pair is connected with a randomly chosen soft or hard Hookean spring. Every spring has the common threshold of stress at which it is cut. We make an initial crack and expand the system perpendicularly to the crack. We find that the maximum stress in the stress-strain curve is larger than those in the systems with soft or hard springs only (uniform systems). Energy required to advance fracture is also larger in some disordered systems, which indicates that the fracture toughness improves. The increase of the energy is caused by the following two factors. One is that the soft spring is able to hold larger energy than the hard one. The other is that the number of cut springs increases as the fracture surface becomes tortuous in disordered systems.

Chiyori Urabe; Shinji Takesue

2008-12-29T23:59:59.000Z

144

Map-making in small field modulated CMB polarisation experiments: approximating the maximum-likelihood method  

E-Print Network [OSTI]

Map-making presents a significant computational challenge to the next generation of kilopixel CMB polarisation experiments. Years worth of time ordered data (TOD) from thousands of detectors will need to be compressed into maps of the T, Q and U Stokes parameters. Fundamental to the science goal of these experiments, the observation of B-modes, is the ability to control noise and systematics. In this paper, we consider an alternative to the maximum-likelihood method, called destriping, where the noise is modelled as a set of discrete offset functions and then subtracted from the time-stream. We compare our destriping code (Descart: the DEStriping CARTographer) to a full maximum-likelihood map-maker, applying them to 200 Monte-Carlo simulations of time-ordered data from a ground based, partial-sky polarisation modulation experiment. In these simulations, the noise is dominated by either detector or atmospheric 1/f noise. Using prior information of the power spectrum of this noise, we produce destriped maps of T, Q and U which are negligibly different from optimal. The method does not filter the signal or bias the E or B-mode power spectra. Depending on the length of the destriping baseline, the method delivers between 5 and 22 times improvement in computation time over the maximum-likelihood algorithm. We find that, for the specific case of single detector maps, it is essential to destripe the atmospheric 1/f in order to detect B-modes, even though the Q and U signals are modulated by a half-wave plate spinning at 5-Hz.

D. Sutton; B. R. Johnson; M. L. Brown; P. Cabella; P. G. Ferreira; K. M. Smith

2008-07-23T23:59:59.000Z

145

Correlated spectral variability in brown dwarfs  

E-Print Network [OSTI]

Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared (0.95-1.64 micron) spectrophotometric monitoring of four field L and T dwarfs spanning timescales of 0.1-5.5 hrs, the goal being to learn more about the physical nature of this variability. Spectra are analysed differentially with respect to a simultaneously observed reference source in order to remove Earth-atmospheric variations. The variability amplitude detected is typically 2-10%, depending on the source and wavelength. I analyse the data for correlated variations between spectral indices. This approach is more robust than single band or chisq analyses, because it does not assume an amplitude for the (often uncertain) noise level (although the significance test still assumes a shape for the noise power spectrum). Three of the four targets show significant evidence for correlated variability. Some of this can be associated with specific features including Fe, FeH, VO and KI, and there is good evidence for intrinsic variability in water and possibly also methan. Yet some of this variability covers a broader spectral range which would be consistent with dust opacity variations. The underlying common cause is plausibly localized temperature or composition fluctuations caused by convection. Looking at the high signal-to-noise ratio stacked spectra we see many previously identified spectral features of L and T dwarfs, such as KI, NaI, FeH, water and methane. In particular we may have detected methane absorption at 1.3-1.4 micron in the L5 dwarf SDSS 0539-0059.

C. A. L. Bailer-Jones

2007-11-28T23:59:59.000Z

146

The impact of solar variability on climate  

SciTech Connect (OSTI)

A general circulation model that simulated changes in solar irradiance and stratospheric ozone was used to investigate the response of the atmosphere to the 11-solar activity cycle. At solar maximum, a warming of the summer stratosphere was found to strengthen shifts in the positions of the subtropical westerly jets, broadening of the tropical Hadley circulations, and poleward shifts of storm tracts. These effects are similiar to, although generally smaller in magnitude than, those observed in nature. A simulation in which only solar irradiance was changed showed a much weaker response. 20 refs., 4 figs., 2 tabs.

Haigh, J.D.

1996-05-17T23:59:59.000Z

147

Impact of orthorectification and spatial sampling on maximum NDVI composite data in mountain regions  

Science Journals Connector (OSTI)

Topography and accuracy of image geometric registration significantly affect the quality of satellite data, since pixels are displaced depending on surface elevation and viewing geometry. This effect should be corrected for through the process of accurate image navigation and orthorectification in order to meet the geolocation accuracy for systematic observations specified by the Global Climate Observing System (GCOS) requirements for satellite climate data records. We investigated the impact of orthorectification on the accuracy of maximum Normalized Difference Vegetation Index (NDVI) composite data for a mountain region in north-western Canada at various spatial resolutions (1 km, 4 km, 5 km, and 8 km). Data from AVHRR on board NOAA-11 (1989 and 1990) and NOAA-16 (2001, 2002, and 2003) processed using a system called CAPS (Canadian AVHRR Processing System) for the month of August were considered. Results demonstrate the significant impact of orthorectification on the quality of composite NDVI data in mountainous terrain. Differences between orthorectified and non-orthorectified NDVI composites (?NDVI) adopted both large positive and negative values, with the 1% and 99% percentiles of ?NDVI at 1 km resolution spanning values between ? 0.16 < ?NDVI < 0.09. Differences were generally reduced to smaller numbers for coarser resolution data, but systematic positive biases for non-orthorectified composites were obtained at all spatial resolutions, ranging from 0.02 (1 km) to 0.004 (8 km). Analyzing the power spectra of maximum NDVI composites at 1 km resolution, large differences between orthorectified and non-orthorectified AVHRR data were identified at spatial scales between 4 km and 10 km. Validation of NOAA-16 AVHRR NDVI with MODIS NDVI composites revealed higher correlation coefficients (by up to 0.1) for orthorectified composites relative to the non-orthorectified case. Uncertainties due to the AVHRR Global Area Coverage (GAC) sampling scheme introduce an average positive bias of 0.02 ± 0.03 at maximum NDVI composite level that translates into an average relative bias of 10.6% ± 19.1 for sparsely vegetated mountain regions. This can at least partially explain the systematic average positive biases we observed relative to our results in AVHRR GAC-based composites from the Global Inventory Modeling and Mapping Studies (GIMMS) and Polar Pathfinder (PPF) datasets (0.19 and 0.05, respectively). With regard to the generation of AVHRR long-term climate data records, results suggest that orthorectification should be an integral part of AVHRR pre-processing, since neglecting the terrain displacement effect may lead to important biases and additional noise in time series at various spatial scales.

Fabio M.A. Fontana; Alexander P. Trishchenko; Konstantin V. Khlopenkov; Yi Luo; Stefan Wunderle

2009-01-01T23:59:59.000Z

148

Development of a methodology to evaluate probable maximum precipitation (PMP) under changing climate conditions: Application to southern Quebec, Canada  

Science Journals Connector (OSTI)

Summary Climate change (CC) needs to be accounted for in the estimation of probable maximum floods (PMFs). However, there does not exist a unique way to estimate \\{PMFs\\} and, furthermore the challenge in estimating them is that they should neither be underestimated for safety reasons nor overestimated for economical ones. By estimating \\{PMFs\\} without accounting for CC, the risk of underestimation could be high for Quebec, Canada, since future climate simulations indicate that in all likelihood extreme precipitation events will intensify. In this paper, simulation outputs from the Canadian Regional Climate Model (CRCM) are used to develop a methodology to estimate probable maximum precipitations (PMPs) while accounting for changing climate conditions for the southern region of the Province of Quebec, Canada. The Kénogami and Yamaska watersheds are herein of particular interest, since dam failures could lead to major downstream impacts. Precipitable water (w) represents one of the key variables in the estimation process of PMPs. Results of stationary tests indicate that CC will not only affect precipitation and temperature but also the monthly maximum precipitable water, wmax, and the ensuing maximization ratio used for the estimation of PMPs. An up-to-date computational method is developed to maximize w using a non-stationary frequency analysis, and then calculate the maximization ratios. The ratios estimated this way are deemed reliable since they rarely exceed threshold values set for Quebec, and, therefore, provide consistent PMP estimates. The results show an overall significant increase of the \\{PMPs\\} throughout the current century compared to the recent past.

Alain N. Rousseau; Iris M. Klein; Daphné Freudiger; Patrick Gagnon; Anne Frigon; Claudie Ratté-Fortin

2014-01-01T23:59:59.000Z

149

Climate variability in the northern Atlantic, causes and consequences: ICES NAFO Decadal  

E-Print Network [OSTI]

Climate variability in the northern Atlantic, causes and consequences: ICES ­ NAFO Decadal to numerous ground-truth observations, including the Rossby Oleander sections of the Gulf Stream

150

Installation of the MAXIMUM microscope at the ALS  

SciTech Connect (OSTI)

The MAXIMUM scanning x-ray microscope, developed at the Synchrotron Radiation Center (SRC) at the University of Wisconsin, Madison was implemented on the Advanced Light Source in August of 1995. The microscope`s initial operation at SRC successfully demonstrated the use of multilayer coated Schwarzschild objective for focusing 130 eV x-rays to a spot size of better than 0.1 micron with an electron energy resolution of 250meV. The performance of the microscope was severely limited, because of the relatively low brightness of SRC, which limits the available flux at the focus of the microscope. The high brightness of the ALS is expected to increase the usable flux at the sample by a factor of 1,000. The authors will report on the installation of the microscope on bending magnet beamline 6.3.2 at the ALS and the initial measurement of optical performance on the new source, and preliminary experiments with surface chemistry of HF etched Si will be described.

Ng, W.; Perera, R.C.C.; Underwood, J.H. [Lawrence Berkeley Lab., CA (United States); Singh, S.; Solak, H.; Cerrina, F. [Univ. of Wisconsin, Stoughton, WI (United States). Center for X-ray Lithography

1995-10-01T23:59:59.000Z

151

LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL  

SciTech Connect (OSTI)

The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.

Don Augenstein

2001-02-01T23:59:59.000Z

152

INTEGRAL observations of SS433: Results of coordinated campaign  

E-Print Network [OSTI]

Results of simultaneous INTEGRAL and optical observations of galactic microquasar SS433 in May 2003 and INTEGRAL/RXTE observations in March 2004 are presented. Persistent precessional variability with a maximum to minimum uneclipsed hard X-ray flux ratio of \\sim 4 is discovered. The 18-60 keV X-ray eclipse is found to be in phase with optical and near infrared eclipses. The orbital eclipse observed by INTEGRAL in May 2003 is at least two times deeper and apparently wider than in soft X-ray band. The broadband X-ray spectrum 2-100 keV simultaneously detected by RXTE/INTEGRAL in March 2004 can be described by bremsstrahlung emission from optically thin thermal plasma with kT\\sim 30 keV. The optical spectroscopy with the 6-m SAO BTA telescope confirmed the optical companion to be an A5-A7 supergiant. For the first time, spectorscopic indications of a strong heating effect in the optical star atmosphere are found. The measurements of absorption lines which are presumably formed in the non-illuminated side of the supergiant yield its radial velocity semi-amplitude K_v=132\\pm 9 km/s. The analysis of the observed hard X-ray light curve and the eclipse duration, combined with spectroscopically found optical star radial velocity corrected for the strong heating effect, allows us to model SS433 as a massive X-ray binary. Assuming that the hard X-ray source in SS433 is eclipsed by the donor star that exactly fills its Roche lobe, the masses of the optical and compact components in SS433 are suggested to be M_v\\approx 30 M_\\odot and M_x\\approx 9M_\\odot, respectively. This provides further evidence that SS433 is a massive binary system with supercritical accretion onto a black hole.

A. M. Cherepashchuk; R. A. Sunyaev; S. N. Fabrika; K. A. Postnov; S. V. Molkov; E. A. Barsukova; E. A. Antokhina; T. R. Irsmambetova; I. E. Panchenko; E. V. Seifina; N. I. Shakura; A. N. Timokhin; I. F. Bikmaev; N. A. Sakhibullin; Z. Aslan; I. Khamitov; A. G. Pramsky; O. Sholukhova; Yu. N. Gnedin; A. A. Arkharov; V. M. Larionov

2005-03-16T23:59:59.000Z

153

Monitoring variability of multivariate processes  

Science Journals Connector (OSTI)

The paper focuses on determining changes in process variability of multivariate processes. The problem is compounded by the fact that any of the elements in the variance-covariance matrix of variables could change, leading to a change in the process variability. While it may not be feasible to maintain individual control charts for each element of the variance-covariance matrix, some aggregate measure of the variability criteria could be monitored to initially determine if a change has occurred in the process variability. A couple of aggregate measures are proposed and the performance of these suggested measures is explored through a simulation procedure. Compared to the traditional method, which monitors the determinant of the variance-covariance matrix, these alternatives perform well. The performance measure used is the mean time to first detection of a change in the process variability.

Amitava Mitra; Mark Clark

2014-01-01T23:59:59.000Z

154

Online Robot Dead Reckoning Localization Using Maximum Relative Entropy Optimization With Model Constraints  

SciTech Connect (OSTI)

The principle of Maximum relative Entropy optimization was analyzed for dead reckoning localization of a rigid body when observation data of two attached accelerometers was collected. Model constraints were derived from the relationships between the sensors. The experiment's results confirmed that accelerometers each axis' noise can be successfully filtered utilizing dependency between channels and the dependency between time series data. Dependency between channels was used for a priori calculation, and a posteriori distribution was derived utilizing dependency between time series data. There was revisited data of autocalibration experiment by removing the initial assumption that instantaneous rotation axis of a rigid body was known. Performance results confirmed that such an approach could be used for online dead reckoning localization.

Urniezius, Renaldas [Kaunas University of Technology, Kaunas (Lithuania)

2011-03-14T23:59:59.000Z

155

Comparative analysis of structural transformations of two bituminous coals with different maximum fluidity during carbonization  

SciTech Connect (OSTI)

The variation of the volume of two bituminous coals with different maximum fluidity (MF) values has been determined using carbonization tests, and the quality of coke obtained has been examined using scanning electron microscopy (SEM) micrographs. The structural and chemical changes in bituminous coals at the pre-plastic stage during carbonization were studied using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques and compared to the changes in their electric and dielectric parameters. It was observed that the structural and chemical transformations occurred in the disordered phase of both coals in different ways. These differences are attributed to the different redistributions of hydrogen between the radicals generated in the aliphatic and aromatic parts of the macromolecule fragments. 42 refs., 12 figs., 2 tabs.

Valentina Zubkova; Victor Prezhdo; Andrzej Strojwas [Jan Kochanowski University, Kielce (Poland). Institute of Chemistry

2007-06-15T23:59:59.000Z

156

Envera Variable Compression Ratio Engine  

SciTech Connect (OSTI)

Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsiz

Charles Mendler

2011-03-15T23:59:59.000Z

157

Probable maximum point rainfall estimation for the southern half of the Indian peninsula  

Science Journals Connector (OSTI)

Preparation of a generalized chart of probable maximum precipitation (PMP) for the southern half of the Indian peninsula lying between lat. 8°N to 16°N has been attempted in this study. Maximum 1-day rainfall ...

O N Dhar; A K Kulkarni; P R Rakhecha

1981-03-01T23:59:59.000Z

158

Selection automatique de variables pertinentes  

E-Print Network [OSTI]

S´election automatique de variables pertinentes Vers la d´ecouverte de nouvelles modalit´es sensori-motrices corr´elations entre ses variables sensori-motrices afin d'apprendre `a r´esoudre sa t^ache d

Boyer, Edmond

159

Design of a variable reluctance asymmetric stepping millimotor  

SciTech Connect (OSTI)

This paper reports on the design, simulation, and preliminary testing of a three phase variable reluctance stepping motor. This motor is pancake-shaped with an overall outside diameter of 8 mm and a height of 3 mm. The outside diameter of the rotor is 4.7 mm. The rotor and stators occupy 2 mm of the height with the remaining 1 mm reserved for a 6:1 planetary gear reductor. The rotor and stators were constructed of Hyperco 50 using conventional miniature machining. The reductor was assembled using copper and PMMA (polymethylmethacrylate) components that were constructed using the LIGA (Lithographic Galvanoformung Abformung) microfabrication process. The maximum measured stall torque of the motor without the reductor is 0.47mNm at 4W and the maximum speed is 2,400 rpm.

GARCIA,ERNEST J.; GREENWOOD,WILLIAM H.; OLIVER,ANDREW D.

2000-06-01T23:59:59.000Z

160

A maximum entropy framework for non-exponential distributions  

E-Print Network [OSTI]

Probability distributions having power-law tails are observed in a broad range of social, economic, and biological systems. We describe here a potentially useful common framework. We derive distribution functions $\\{p_k\\}$ for situations in which a `joiner particle' $k$ pays some form of price to enter a `community' of size $k-1$, where costs are subject to economies-of-scale (EOS). Maximizing the Boltzmann-Gibbs-Shannon entropy subject to this energy-like constraint predicts a distribution having a power-law tail; it reduces to the Boltzmann distribution in the absence of EOS. We show that the predicted function gives excellent fits to 13 different distribution functions, ranging from friendship links in social networks, to protein-protein interactions, to the severity of terrorist attacks. This approach may give useful insights into when to expect power-law distributions in the natural and social sciences.

Peterson, Jack; Dill, Ken A

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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161

Depth of Maximum of Air-Shower Profiles at the Pierre Auger Observatory: Composition Implications  

E-Print Network [OSTI]

Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (Xmax), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the distributions with predictions from a variety of hadronic interaction models for variations in the composition of the primary cosmic rays and examining the quality of the fit. Regardless of what interaction model is assumed, we find that our data are not well described by a mix of protons and iron nuclei over most of the energy range. Acceptable fits can be obtained when intermediate masses are included, and when this is done consistent results for the proton and iron-nuclei contributions can be found using the available models. We observe a strong energy dependence of the resulting proton fractions, and find no support from any of the models for a significant contribution from iron nuclei. However, we also observe a...

,

2014-01-01T23:59:59.000Z

162

SDSS J2222+2745: A GRAVITATIONALLY LENSED SEXTUPLE QUASAR WITH A MAXIMUM IMAGE SEPARATION OF 15.''1 DISCOVERED IN THE SLOAN GIANT ARCS SURVEY  

SciTech Connect (OSTI)

We report the discovery of a unique gravitational lens system, SDSS J2222+2745, producing five spectroscopically confirmed images of a z{sub s} = 2.82 quasar lensed by a foreground galaxy cluster at z{sub l} = 0.49. We also present photometric and spectroscopic evidence for a sixth lensed image of the same quasar. The maximum separation between the quasar images is 15.''1. Both the large image separations and the high image multiplicity are in themselves rare among known lensed quasars, and observing the combination of these two factors is an exceptionally unlikely occurrence in present data sets. This is only the third known case of a quasar lensed by a cluster, and the only one with six images. The lens system was discovered in the course of the Sloan Giant Arcs Survey, in which we identify candidate lenses in the Sloan Digital Sky Survey and target these for follow-up and verification with the 2.56 m Nordic Optical Telescope. Multi-band photometry obtained over multiple epochs from 2011 September to 2012 September reveals significant variability at the {approx}10%-30% level in some of the quasar images, indicating that measurements of the relative time delay between quasar images will be feasible. In this lens system, we also identify a bright (g = 21.5) giant arc corresponding to a strongly lensed background galaxy at z{sub s} = 2.30. We fit parametric models of the lens system, constrained by the redshift and positions of the quasar images and the redshift and position of the giant arc. The predicted time delays between different pairs of quasar images range from {approx}100 days to {approx}6 yr.

Dahle, H.; Groeneboom, N. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, NO-0315 Oslo (Norway); Gladders, M. D.; Abramson, L. E. [Department of Astronomy and Astrophysics, The University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States); Sharon, K. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Bayliss, M. B. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Wuyts, E. [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbackstrasse 1, D-85748 Garching bei Muenchen (Germany); Koester, B. P. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Brinckmann, T. E.; Kristensen, M. T.; Lindholmer, M. O.; Nielsen, A.; Krogager, J.-K.; Fynbo, J. P. U., E-mail: hdahle@astro.uio.no [Dark Cosmology Centre, Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark)

2013-08-20T23:59:59.000Z

163

Ocean Observing Ocean Observing Systems (OOS)  

E-Print Network [OSTI]

, national, and global scales. · Ocean Observing Systems serve: Fishing industry National security Coastal properties, such as salinity, temperature, and waves Satellite maps of sea surface temperature NATIONAL Integrated Ocean Observing System (IOOS) 11 REGIONAL Systems, including: MANY LOCAL Systems

Schladow, S. Geoffrey

164

Exploring the Variable Sky with the Sloan Digital Sky Survey  

E-Print Network [OSTI]

We quantify the variability of faint unresolved optical sources using a catalog based on multiple SDSS imaging observations. The catalog covers SDSS Stripe 82, and contains 58 million photometric observations in the SDSS ugriz system for 1.4 million unresolved sources. In each photometric bandpass we compute various low-order lightcurve statistics and use them to select and study variable sources. We find that 2% of unresolved optical sources brighter than g=20.5 appear variable at the 0.05 mag level (rms) simultaneously in the g and r bands. The majority (2/3) of these variable sources are low-redshift (<2) quasars, although they represent only 2% of all sources in the adopted flux-limited sample. We find that at least 90% of quasars are variable at the 0.03 mag level (rms) and confirm that variability is as good a method for finding low-redshift quasars as is the UV excess color selection (at high Galactic latitudes). We analyze the distribution of lightcurve skewness for quasars and find that is centered on zero. We find that about 1/4 of the variable stars are RR Lyrae stars, and that only 0.5% of stars from the main stellar locus are variable at the 0.05 mag level. The distribution of lightcurve skewness in the g-r vs. u-g color-color diagram on the main stellar locus is found to be bimodal (with one mode consistent with Algol-like behavior). Using over six hundred RR Lyrae stars, we demonstrate rich halo substructure out to distances of 100 kpc. We extrapolate these results to expected performance by the Large Synoptic Survey Telescope and estimate that it will obtain well-sampled 2% accurate, multi-color lightcurves for ~2 million low-redshift quasars, and will discover at least 50 million variable stars.

Branimir Sesar; Zeljko Ivezic; Robert H. Lupton; Mario Juric; James E. Gunn; Gillian R. Knapp; Nathan De Lee; J. Allyn Smith; Gajus Miknaitis; Huan Lin; Douglas Tucker; Mamoru Doi; Masayuki Tanaka; Masataka Fukugita; Jon Holtzman; Steve Kent; Brian Yanny; David Schlegel; Douglas Finkbeiner; Nikhil Padmanabhan; Constance M. Rockosi; Nicholas Bond; Brian Lee; Chris Stoughton; Sebastian Jester; Hugh Harris; Paul Harding; Jon Brinkmann; Donald P. Schneider; Donald York; Michael W. Richmond; Daniel Vanden Berk

2007-04-04T23:59:59.000Z

165

MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS  

SciTech Connect (OSTI)

Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying and interpreting variability on a decadal timescale, here we present a mid-infrared spectral atlas containing observations of 68 low- and intermediate-mass young stellar objects. The atlas consists of 2.5-11.6 {mu}m low-resolution spectra obtained with the ISOPHOT-S instrument on board the Infrared Space Observatory (ISO) between 1996 and 1998, as well as 5.2-14.5 {mu}m low-resolution spectra obtained with the Infrared Spectrograph instrument on board the Spitzer Space Telescope between 2004 and 2007. The observations were retrieved from the ISO and Spitzer archives and were post-processed interactively by our own routines. For those 47 objects where multi-epoch spectra were available, we analyze mid-infrared spectral variability on annual and/or decadal timescales. We identify 37 variable candidate sources. Many stars show wavelength-independent flux changes, possibly due to variable accretion rates. In several systems, all exhibiting 10 {mu}m silicate emission, the variability of the 6-8 {mu}m continuum, and the silicate feature exhibit different amplitudes. A possible explanation is variable shadowing of the silicate-emitting region by an inner disk structure of changing height or extra silicate emission from dust clouds in the disk atmosphere. Our results suggest that mid-infrared variability, in particular, the wavelength-dependent changes, is more ubiquitous than was known before. Interpreting this variability is a new possibility for exploring the structure of the disk and its dynamical processes.

Kospal, A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Abraham, P.; Kun, M.; Moor, A. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, 1525 Budapest (Hungary); Acosta-Pulido, J. A. [Instituto de Astrofisica de Canarias, Via Lactea s/n, 38200 La Laguna, Tenerife (Spain); Dullemond, C. P. [Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie der Universitaet Heidelberg, Albert-Ueberle-Str. 2, 69120 Heidelberg (Germany); Henning, Th.; Leinert, Ch. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Turner, N. J., E-mail: akospal@rssd.esa.int [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2012-08-01T23:59:59.000Z

166

The Wind of Variable C in M33  

E-Print Network [OSTI]

We discuss the spectrum of Var C in M33 obtained just before the onset of its current brightening and recent spectra during its present "eruption" or optically thick wind stage. These spectra illustrate the typical LBV transition in apparent spectral type or temperature that characterizes the classical LBV or S Dor-type variability. LBVs are known to have slow, dense winds during their maximum phase. Interestingly, Var C had a slow wind even during its hot, quiescent stage in comparison with the normal hot supergiants with similar temperatures. Its outflow or wind speeds also show very little change between these two states.

Humphreys, Roberta M; Gordon, Michael; Weis, Kerstin; Burggraf, Birgitta; Bomans, D J; Martin, John C

2014-01-01T23:59:59.000Z

167

The TAOS Project Stellar Variability II. Detection of 15 Variable Stars  

SciTech Connect (OSTI)

The Taiwanese-American Occultation Survey (TAOS) project has collected more than a billion photometric measurements since 2005 January. These sky survey data - covering timescales from a fraction of a second to a few hundred days - are a useful source to study stellar variability. A total of 167 star fields, mostly along the ecliptic plane, have been selected for photometric monitoring with the TAOS telescopes. This paper presents our initial analysis of a search for periodic variable stars from the time-series TAOS data on one particular TAOS field, No. 151 (RA = 17{sup h} 30{sup m} 6.67{sup s}, Dec = 27 degrees, 17 minutes, 30 seconds, J2000), which had been observed over 47 epochs in 2005. A total of 81 candidate variables are identified in the 3 square degree field, with magnitudes in the range 8 < R < 16. On the basis of the periodicity and shape of the lightcurves, 32 variables, 18 of which were previously unknown, are classified as RR Lyrae, Cepheid, {delta} Scuti, SX Phonencis, semi-regular and eclipsing binaries.

Mondal, S; Lin, C C; Zhang, Z W; Alcock, C; Axelrod, T; Bianco, F B; Byun, Y I; Coehlo, N K; Cook, K H; Dave, R; Kim, D W; King, S K; Lee, T; Lehner, M J; Lin, H C; Marshall, S L; Protopapas, P; Rice, J A; Schwamb, M E; Wang, J H; Wang, S Y; Wen, C Y

2010-01-28T23:59:59.000Z

168

BROAD ABSORPTION LINE VARIABILITY ON MULTI-YEAR TIMESCALES IN A LARGE QUASAR SAMPLE  

SciTech Connect (OSTI)

We present a detailed investigation of the variability of 428 C IV and 235 Si IV broad absorption line (BAL) troughs identified in multi-epoch observations of 291 quasars by the Sloan Digital Sky Survey-I/II/III. These observations primarily sample rest-frame timescales of 1-3.7 yr over which significant rearrangement of the BAL wind is expected. We derive a number of observational results on, e.g., the frequency of BAL variability, the velocity range over which BAL variability occurs, the primary observed form of BAL-trough variability, the dependence of BAL variability upon timescale, the frequency of BAL strengthening versus weakening, correlations between BAL variability and BAL-trough profiles, relations between C IV and Si IV BAL variability, coordinated multi-trough variability, and BAL variations as a function of quasar properties. We assess implications of these observational results for quasar winds. Our results support models where most BAL absorption is formed within an order-of-magnitude of the wind-launching radius, although a significant minority of BAL troughs may arise on larger scales. We estimate an average lifetime for a BAL trough along our line-of-sight of a few thousand years. BAL disappearance and emergence events appear to be extremes of general BAL variability, rather than being qualitatively distinct phenomena. We derive the parameters of a random-walk model for BAL EW variability, finding that this model can acceptably describe some key aspects of EW variability. The coordinated trough variability of BAL quasars with multiple troughs suggests that changes in 'shielding gas' may play a significant role in driving general BAL variability.

Filiz Ak, N.; Brandt, W. N.; Schneider, D. P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Hall, P. B. [Department of Physics and Astronomy, York University, 4700 Keele St., Toronto, Ontario, M3J 1P3 (Canada); Anderson, S. F. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Hamann, F. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Lundgren, B. F. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Pâris, I. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Petitjean, P. [Universite Paris 6, Institut d'Astrophysique de Paris, 75014, Paris (France); Ross, Nicholas P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 92420 (United States); Shen, Yue [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-51, Cambridge, MA 02138 (United States); York, Don, E-mail: nfilizak@astro.psu.edu [The University of Chicago, Department of Astronomy and Astrophysics, Chicago, IL 60637 (United States)

2013-11-10T23:59:59.000Z

169

Maximum Entropy and Bayesian Statistics in Crystallography: a Review of Practical Applications  

Science Journals Connector (OSTI)

The applications of the maximum entropy and Bayesian methods to problems in X-ray, neutron and electron crystallography are reviewed.

Gilmore, C.J.

1996-07-01T23:59:59.000Z

170

Observing Healthcare Interior Environments and the Effect on Patient Behavior  

E-Print Network [OSTI]

variables in the interior environments that have the greatest impact, whether positive or negative, on patients. The methods used to perform this research include: inspections of the facility, observations, and surveys. By combining all of these methods...

Rice, Courtney R.

2010-07-14T23:59:59.000Z

171

Reading with fixed and variable character pitch  

Science Journals Connector (OSTI)

We compared the effects of fixed and variable (proportional) spacing on reading speeds and found variable pitch to yield better performance at medium and large character sizes and...

Arditi, Aries; Knoblauch, Kenneth; Grunwald, Ilana

1990-01-01T23:59:59.000Z

172

Testing quantum contextuality of continuous-variable states  

SciTech Connect (OSTI)

We investigate the violation of noncontextuality by a class of continuous-variable states, including variations of entangled coherent states and a two-mode continuous superposition of coherent states. We generalize the Kochen-Specker (KS) inequality discussed by Cabello [A. Cabello, Phys. Rev. Lett. 101, 210401 (2008)] by using effective bidimensional observables implemented through physical operations acting on continuous-variable states, in a way similar to an approach to the falsification of Bell-Clauser-Horne-Shimony-Holt inequalities put forward recently. We test for state-independent violation of KS inequalities under variable degrees of state entanglement and mixedness. We then demonstrate theoretically the violation of a KS inequality for any two-mode state by using pseudospin observables and a generalized quasiprobability function.

McKeown, Gerard; Paternostro, Mauro [School of Mathematics and Physics, Queen's University, Belfast, BT7 1NN (United Kingdom); Paris, Matteo G. A. [Dipartimento di Fisica, Universita degli Studi di Milano, I-20133 Milan (Italy); Consorzio Nazionale Italiano di Struttura della Materia, Udr Milano, I-20133 Milan (Italy)

2011-06-15T23:59:59.000Z

173

Occurrence of high-speed solar wind streams over the Grand Modern Maximum  

E-Print Network [OSTI]

In the declining phase of the solar cycle, when the new-polarity fields of the solar poles are strengthened by the transport of same-signed magnetic flux from lower latitudes, the polar coronal holes expand and form non-axisymmetric extensions toward the solar equator. These extensions enhance the occurrence of high-speed solar wind streams (HSS) and related co-rotating interaction regions in the low-latitude heliosphere, and cause moderate, recurrent geomagnetic activity in the near-Earth space. Here, using a novel definition of geomagnetic activity at high (polar cap) latitudes and the longest record of magnetic observations at a polar cap station, we calculate the annually averaged solar wind speeds as proxies for the effective annual occurrence of HSS over the whole Grand Modern Maximum (GMM) from 1920s onwards. We find that a period of high annual speeds (frequent occurrence of HSS) occurs in the declining phase of each solar cycle 16-23. For most cycles the HSS activity clearly maximizes during one year...

Mursula, Kalevi; Holappa, Lauri

2015-01-01T23:59:59.000Z

174

Electro-Thermal Dynamics and the Effects of Generalized Discontinuous Pulse Width Modulation Algorithms on High Performance Variable Frequency Drives.  

E-Print Network [OSTI]

??This thesis is concerned with issues observed with the variable frequency drive, VFD, traction inverter used in the Buckeye Bullet 3 as it performed during… (more)

Krohn, Austin Bengoechea

2014-01-01T23:59:59.000Z

175

Urbanization and Rainfall Variability in the Beijing Metropolitan Region  

Science Journals Connector (OSTI)

In this study, rainfall variability in the Beijing metropolitan region and its link to urbanization during the first 10 years of the twenty-first century (2000–09) was examined. Analyses are based on both observations and regional climate model ...

Yan Zhang; James A. Smith; Lifeng Luo; Zifa Wang; Mary Lynn Baeck

2014-12-01T23:59:59.000Z

176

Intraseasonal Variability of Equatorial Indian Ocean Zonal Currents  

Science Journals Connector (OSTI)

New satellite and in situ observations show large intraseasonal (10–60 day) variability of surface winds and upper-ocean current in the equatorial Indian Ocean, particularly in the east. An ocean model forced by the Quick Scatterometer (QuikSCAT) ...

Debasis Sengupta; Retish Senan; B. N. Goswami; Jérôme Vialard

2007-07-01T23:59:59.000Z

177

Trapping and Frequency Variability in Electron Acoustic Waves  

E-Print Network [OSTI]

Trapping and Frequency Variability in Electron Acoustic Waves C.F. Driscoll, F. Anderegg, D 92093 USA Abstract. Electron Acoustic Waves (EAWs) with a phase velocity less than twice the plasma Langmuir waves, and at large excitations resonance is observed over a broad range. Laser Induced

California at San Diego, University of

178

Near-Infrared, Kilosecond Variability of the Wisps And Jet in the Crab Pulsar Wind Nebula  

SciTech Connect (OSTI)

We present a time-lapse sequence of 20 near-infrared (J- and K'-band) snapshots of the central 20'' x 20'' of the Crab pulsar wind nebula, taken at sub-arcsecond resolution with the Hokupa'a/QUIRC adaptive optics camera on the Gemini North Telescope, and sampled at intervals of 10 minutes and 24 hours. It is observed that the equatorial wisps and polar knots in the termination shock of the pulsar wind appear to fluctuate in brightness on kilosecond time-scales. Maximum flux variations of {+-}24 {+-} 4 and {+-}14 {+-} 4 per cent relative to the mean (in 1.2 ks) are measured for the wisps and knots respectively, with greatest statistical significance in J band where the nebula background is less prominent. The J and K' flux densities imply different near-infrared spectra for the nonthermal continuum emission from the wisps and outermost polar knot (''sprite''), giving F{sub {nu}} {proportional_to} {nu}{sup -0.56{+-}0.12} and F{sub {nu}} {proportional_to} {nu}{sup -0.21{+-}0.13} respectively. The data are compared with existing optical and UV photometry and applied to constrain theories of the variability of the wisps (relativistic ion-cyclotron instability) and knots (relativistic fire hose instability).

Melatos, Andrew; Scheltus, D.; /Melbourne U.; Whiting, M.T.; /New South Wales U.; Eikenberry, S.S.; /Florida U.; Romani, R.W.; /Stanford U., Phys. Dept.; Rigaut, F.; /Gemini; Spitkovsky, A.; /KIPAC, Menlo Park; Arons, J.; /UC, Berkeley, Astron. Dept.; Payne, D.J.B.; /Melbourne U.

2006-01-11T23:59:59.000Z

179

An Improved Maximum Likelihood Formulation for Accurate Genome Assembly Aditya Varma, Abhiram Ranade and Srinivas Aluru  

E-Print Network [OSTI]

An Improved Maximum Likelihood Formulation for Accurate Genome Assembly Aditya Varma, Abhiram maximum likelihood method for genome assembly. We formulate the problem as one of direct convex estimate of the length of the genome or the need to use further expectation minimization to predict

Ranade, Abhiram G.

180

A 6/5-approximation algorithm for the maximum 3-cover problem  

Science Journals Connector (OSTI)

In the maximum cover problem, we are given a collection of sets over a ground set of elements and a positive integer w, and we are asked to compute a collection of at most w sets whose union contains the maximum ...

Ioannis Caragiannis; Gianpiero Monaco

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

A Basic Thermodynamic Derivation of the Maximum Overburden Pressure Generated in Frost Heave  

E-Print Network [OSTI]

can derive the maximum overburden pressure. A similar argument can also produce the maximum Heave Engine Frost heave is a common environmental process in which the freezing of water into ice can produce forces large enough to seriously damage roads and bridges [1]. Contrary to common belief, frost

Libbrecht, Kenneth G.

182

LANGMUIR WAVE ACTIVITY: COMPARING THE ULYSSES SOLAR MINIMUM AND SOLAR MAXIMUM ORBITS  

E-Print Network [OSTI]

). The top three panels correspond to the southern segment of the solar minimum orbit; repeated passesLANGMUIR WAVE ACTIVITY: COMPARING THE ULYSSES SOLAR MINIMUM AND SOLAR MAXIMUM ORBITS R. J at the electron plasma frequency) during the solar minimum and solar maximum orbits of Ulysses. At high latitudes

California at Berkeley, University of

183

On the duration of the Paleocene-Eocene thermal maximum Ursula Rohl and Thomas Westerhold  

E-Print Network [OSTI]

On the duration of the Paleocene-Eocene thermal maximum (PETM) Ursula Ro¨hl and Thomas Westerhold of California, Santa Cruz, California 95064, USA [1] The Paleocene-Eocene thermal maximum (PETM) is one of global warming and a massive perturbation of the global carbon cycle from injection of isotopically light

Zachos, James

184

Low-energy particle response to CMEs during the Ulysses solar maximum northern polar passage  

E-Print Network [OSTI]

Low-energy particle response to CMEs during the Ulysses solar maximum northern polar passage D. Reisenfeld, and T. R. Sanderson (2004), Low-energy particle response to CMEs during the Ulysses solar maximum, New Mexico, USA T. R. Sanderson Research and Scientific Support Department of European Space Agency

Sanahuja, Blai

185

Use of Two Distillation Columns in Systems with Maximum Temperature Limitations  

E-Print Network [OSTI]

Use of Two Distillation Columns in Systems with Maximum Temperature Limitations Rebecca H. Masel, Pennsylvania 18015, United States ABSTRACT: Maximum temperature limitations are encountered in distillation of the bottoms product fixes the column base pressure and, hence, the condenser pressure. The distillate

Gilchrist, James F.

186

An Optimal Randomized Algorithm for Maximum Tukey Depth Timothy M. Chan  

E-Print Network [OSTI]

An Optimal Randomized Algorithm for Maximum Tukey Depth Timothy M. Chan Abstract We present the first optimal algorithm to compute the maximum Tukey depth (also known as location or halfspace depth , the Tukey depth of a point q IRd is defined as: min{|P | : over all halfspaces containing q}. We

Chan, Timothy M.

187

High order maximum principle preserving semi-Lagrangian finite difference WENO schemes for the Vlasov equation  

Science Journals Connector (OSTI)

In this paper, we propose the parametrized maximum principle preserving (MPP) flux limiter, originally developed in [37], to the semi-Lagrangian finite difference weighted essentially non-oscillatory scheme for solving the Vlasov equation. The MPP flux ... Keywords: Finite difference WENO scheme, Maximum principle preserving, Parametrized flux limiter, Semi-Lagrangian method, Vlasov equation

Tao Xiong, Jing-Mei Qiu, Zhengfu Xu, Andrew Christlieb

2014-09-01T23:59:59.000Z

188

Beating the maximum cooling limit with graded thermoelectric materials Zhixi Bian and Ali Shakouria  

E-Print Network [OSTI]

.1063/1.2396895 The maximum cooling temperature is one of the perfor- mance parameters for a thermoelectric module. ExcludingBeating the maximum cooling limit with graded thermoelectric materials Zhixi Bian and Ali Shakouria cooling of a single element thermoelectric material cannot be improved by changing its geometry.3

189

Frequency Moments Inverse Problem and Maximum (Shannon vs. R enyi-Tsallis) Entropy  

E-Print Network [OSTI]

) maximization of Shannon's entropy (MaxEnt), b) maximization of R#19;enyi-Tsallis entropy (maxTent). ConcerningEnt 4 1.2 Aims 5 2 Frequency moment constraints 5 2.1 Characteristics of MaxEnt choice 6 2.2 Maximum RFrequency Moments Inverse Problem and Maximum (Shannon vs. R#19;enyi-Tsallis) Entropy #3; A case

190

Operating Reserves and Variable Generation  

SciTech Connect (OSTI)

This report tries to first generalize the requirements of the power system as it relates to the needs of operating reserves. It also includes a survey of operating reserves and how they are managed internationally in system operations today and then how new studies and research are proposing they may be managed in the future with higher penetrations of variable generation.

Ela, E.; Milligan, M.; Kirby, B.

2011-08-01T23:59:59.000Z

191

Cosmological models with variable constants  

E-Print Network [OSTI]

The behavior of the constants, G,c,h,a,e,m and Lambda, considering them as variable, in the framework of a flat cosmological model with FRW symmetries described by a bulk viscous fluid and considering mechanisms of adiabatic matter creation are investigated. Within two models; one with radiation predominance and another of matter predominance, this behavior are studied.

J. A. Belinchon

1999-07-01T23:59:59.000Z

192

WASTE SOLIDIFICATION BUILDING BENCH SCALE HIGH ACTIVITY WASTE SIMULANT VARIABILITY STUDY FY2008  

SciTech Connect (OSTI)

The primary objective of this task was to perform a variability study of the high activity waste (HAW) acidic feed to determine the impact of feed variability on the quality of the final grout and on the mixability of the salt solution into the dry powders. The HAW acidic feeds were processed through the neutralization/pH process, targeting a final pH of 12. These fluids were then blended with the dry materials to make the final waste forms. A secondary objective was to determine if elemental substitution for cost prohibitive or toxic elements in the simulant affects the mixing response, thus providing a more economical simulant for use in full scale tests. Though not an objective, the HAW simulant used in the full scale tests was also tested and compared to the results from this task. A statistically designed test matrix was developed based on the maximum molarity inputs used to make the acidic solutions. The maximum molarity inputs were: 7.39 HNO{sub 3}, 0.11618 gallium, 0.5423 silver, and 1.1032 'other' metals based on their NO{sub 3}{sup -} contribution. Substitution of the elements aluminum for gallium and copper for silver was also considered in this test matrix, resulting in a total of 40 tests. During the NaOH addition, the neutralization/pH adjustment process was controlled to a maximum temperature of 60 C. The neutralized/pH adjusted simulants were blended with Portland cement and zircon flour at a water to cement mass ratio of 0.30. The mass ratio of zircon flour to Portland cement was 1/12. The grout was made using a Hobart N-50 mixer running at low speed for two minutes to incorporate and properly wet the dry solids with liquid and at medium speed for five minutes for mixing. The resulting fresh grout was measured for three consecutive yield stress measurements. The cured grout was measured for set, bleed, and density. Given the conditions of preparing the grout in this task, all of the grouts were visually well mixed prior to preparing the grouts for measurements. All of the cured grouts were measured for bleed and set. All of the cured grouts satisfied the bleed and set requirements, where no bleed water was observed on any of the grout samples after one day and all had set within 3 days of curing. This data indicates, for a well mixed product, bleed and set requirement are satisfied for the range of acidic feeds tested in this task. The yield stress measurements provide both an indication on the mixability of the salt solution with dry materials and an indication of how quickly the grout is starting to form structure. The inability to properly mix these two streams into a well mixed grout product will lead to a non-homogeneous mixture that will impact product quality. Product quality issues could be unmixed regions of dry material and hot spots having high concentrations of americium 241. Mixes that were more difficult to incorporate typically resulted in grouts with higher yield stresses. The mixability from these tests will provide Waste Solidification Building (WSB) an indication of which grouts will be more challenging to mix. The first yield stress measurements were statistically compared to a list of variables, specifically the batched chemicals used to make the acidic solutions. The first yield stress was also compared to the physical properties of the acidic solutions, physical and pH properties of the neutralized/pH adjusted solutions, and chemical and physical properties of the grout.

Hansen, E; Timothy Jones, T; Tommy Edwards, T; Alex Cozzi, A

2009-03-20T23:59:59.000Z

193

High-resolution lidar observations of mesospheric sodium and implications for adaptive optics  

Science Journals Connector (OSTI)

Observations of sodium density variability in the upper mesosphere/lower thermosphere, obtained using a high-resolution lidar system, show rapid fluctuations in the sodium centroid...

Pfrommer, Thomas; Hickson, Paul

2010-01-01T23:59:59.000Z

194

Variable trim compressor – a new approach to variable compressor geometry  

Science Journals Connector (OSTI)

ABSTRACT Variable compressor geometry can be employed irrespective of the combustion process selected. It provides the capability of improving response behavior, reducing fuel consumption or cutting exhaust emissions from exhaust-gas turbocharged engines. Previous concepts on variable compressor geometries have been based on using inlet guide vanes to impart a swirl motion to the air that is fed to the compressor with the ultimate aim of enhancing the angle at which the flow of air enters the blade channel. This paper shows an inlet guide configuration that is based on a different operating principle. The inlet guide assembly shown here is designed in a way that minimizes any pressure losses even at high flow rates. Numerical studies were carried out using CFD to test the system's sensitivity. Based on these studies, a rigid conical element was then produced and the potential for increasing efficiency (up to 7% points) and shifting the surge line (up to 33%) verified on a turbocharger test bench. Finally, a design configuration is presented for a variable system.

P. Grigoriadis; S. Müller; A. Benz; M. Sens

2012-01-01T23:59:59.000Z

195

On adaptive grid computations of variable stars  

SciTech Connect (OSTI)

We show that the use of an implicit adaptive-grid technique is an efficient and up-to-date approach for the calculations of radial oscillations in variable stars. We chose as an illustrative example the radiative envelope of an RR Lyrae variable. For the hydrostatic initial model we compare the Lagrangean ratioed zoning with an adaptive-grid rezoning. We show that the adaptive-grid yields an optimal distribution of the mesh points in the sense that the relevant physical features, the H{minus} and He 1{minus}, He 2{minus} ionization zones, are well resolved. For the hydrodynamical evolution we present the full-amplitude model for both the Lagrangean and adaptive-grid computations. We perform a detailed comparison and show that the adaptive-grid method yields limit cycle solutions that are substantially improved over the Lagrangean grid model. This is due to the fact that the Lagrangean mesh sweeps through the ionization zones twice during one oscillation period, whereas the adaptive-mesh resolves them and tracks them continuously. The results are, in particular, smooth radial velocity and light curves. Beyond a physically better defined solution we also observe larger time steps for the convergence towards the limit cycle and for the evolution during one period. 12 refs., 13 figs., 5 tabs.

Cox, A.N.; Deupree, R.G.; Gehmeyr, M.

1991-01-01T23:59:59.000Z

196

Dynamical dark energy or variable cosmological parameters?  

E-Print Network [OSTI]

One of the main aims in the next generation of precision cosmology experiments will be an accurate determination of the equation of state (EOS) for the dark energy (DE). If the latter is dynamical, the resulting barotropic index \\omega should exhibit a non-trivial evolution with the redshift. Usually this is interpreted as a sign that the mechanism responsible for the DE is related to some dynamical scalar field, and in some cases this field may behave non-canonically (phantom field). Present observations seem to favor an evolving DE with a potential phantom phase near our time. In the literature there is a plethora of dynamical models trying to describe this behavior. Here we show that the simplest option, namely a model with a variable cosmological term, \\Lambda=\\Lambda(t), leads in general to a non-trivial effective EOS, with index \\omega_e, which may naturally account for these data features. We prove that in this case there is always a ``crossing'' of the \\omega_e=-1 barrier near our time. We also show how this effect is modulated (or even completely controled) by a variable Newton's constant G=G(t).

Joan Sola; Hrvoje Stefancic

2005-12-21T23:59:59.000Z

197

Dark matter interacts with variable vacuum energy  

E-Print Network [OSTI]

We investigate a spatially flat Friedmann-Robertson-Walker (FRW) scenario with two interacting components, dark matter and variable vacuum energy (VVE) densities, plus two decoupled components, one is a baryon term while the other behaves as a radiation component. We consider a linear interaction in the derivative dark component density. We apply the $\\chi^2$ method to the observational Hubble data for constraining the cosmological parameters and analyze the amount of dark energy in the radiation era for the model. It turns out that our model fulfills the severe bound of $\\Omega_{x}(z\\simeq 1100)survey, the future constraints achievable by Euclid and CMBPol experiments, reported for the behavior of the dark energy at early times, and fulfills the stringent bound $\\Omega_{x}(z\\simeq 10^{10})<0.04$ at $2\\sigma$ level in the big-bang nucleosynthesis epoch. We a...

G, Iván E Sánchez

2014-01-01T23:59:59.000Z

198

Costs of Solar and Wind Power Variability for Reducing CO2 Emissions  

Science Journals Connector (OSTI)

Our research differs from earlier solar PV studies because we use real power output data from operational utility-scale plants to calculate the variability and cost of variability. ... In addition, the ISO utilizes up and down regulation equivalent to the minimum and maximum deviation from qh, respectively (lower right graph). ... (9) The Docket states that ISOs may use the same rate they charge utilities for load variability in Schedule 3. FERC envisions that individual transmission utilities can apply to charge different rates as long as they “demonstrate that the per-unit cost of regulation reserve capacity is somehow different when such capacity is utilized to address system variability associated with generator resources”. ...

Colleen Lueken; Gilbert E. Cohen; Jay Apt

2012-08-09T23:59:59.000Z

199

Massive Variability Surveys from Venezuela  

E-Print Network [OSTI]

At the Venezuela National Astronomical Observatory we are carrying out variability surveys spanning many hundreds of square degrees near the celestial equator, using an 8k x 8k CCD Mosaic Camera optimized for drift-scanning on a 1m Schmidt telescope. Among the initial efforts was a project to obtain the first moderately deep, homogeneous sample of young stars over an area of ~180sqr.deg. encompassing the entire Orion OB1 association, one of the nearest and most active regions of star formation. The results show that variability is a powerful technique to identify pre-main sequence populations, specially in sparse areas devoid of gas and dust. We are currently developing a massive database, equipped with web-based data mining tools, that will make our data and results available to the astronomical community.

Cesar Briceno

2003-04-03T23:59:59.000Z

200

Variable frequency microwave heating apparatus  

DOE Patents [OSTI]

A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN); Johnson, Arvid C. (Lake in the Hills, IL); Thigpen, Larry T. (Angier, NC)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Chapter Seven - Variable speed drives  

Science Journals Connector (OSTI)

Publisher Summary The electromechanical controllers are a kind of variable speed drives (VSDs) that are obsolete but are still in use because when a motor and a drive is combined, they become a power drive system (PDS). There are two ways of varying the speed of an induction motor, either by varying the motor slip or by varying the supply frequency. The preferred practice for electrical speed variation is to change the supply frequency with a variable frequency drive (VFD). Many other designs also have been developed. However, except the specialized applications, few are still in operation. A number of motor and drive manufacturers are now producing the integrated motor/VFD units. These units consist of a motor and a specially designed VFD, produced as a single package, with the VFD unit mounted variously on the top, side, or end of the motor.

Europump; Hydraulic Institute

2005-01-01T23:59:59.000Z

202

Review of Probability Random Variable  

E-Print Network [OSTI]

at close 4) Height of wheel going over a rocky road #12;3 Random Variable Non-examples 1) `Heads' or `Tails' on coin 2) Red or Black ball from urn But we can make these into RV's Basic Idea ­ don't know · Temperature · Wheel height #12;5 Given Continuous RV X... What is the probability that X = x0 ? Oddity : P

Fowler, Mark

203

"Table A52. Nonswitchable Minimum Requirements and Maximum Consumption"  

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

2. Nonswitchable Minimum Requirements and Maximum Consumption" 2. Nonswitchable Minimum Requirements and Maximum Consumption" " Potential by Census Region, 1991" " (Estimates in Physical Units)" ,,,,"RSE" ,"Actual","Minimum","Maximum","Row" "Type of Energy","Consumption","Consumption(a)","Consumption(b)","Factors" "RSE Column Factors:",1,1.2,0.8 ," Total United States" ,"-","-","-" "Electricity Receipts(c) (million kilowatthours)",718480,701478,766887,2 "Natural Gas (billion cubic feet)",5345,3485,5887,2 "Distillate Fuel Oil (thousand barrels)",23885,19113,201081,3.7 "Residual Fuel Oil (thousand barrels)",65837,36488,201921,2.6

204

Matching of photovolatic motor-pump systems for maximum efficiency operation  

Science Journals Connector (OSTI)

A PV array is a nonlinear d.c. source and its operation has to be carefully matched to that of its equivalent electrical load in order to extract the maximum available energy. Two PV pumping schemes are investigated to get the maximum gross mechanical power. The system based on the separately-excited d.c. motor is matched through the control of the motor excitation, while for the system based on the induction motor, the voltage source inverter frequency is controlled by maximum mechanical power operation.

Aziza M. Zaki; Mona N. Eskander

1996-01-01T23:59:59.000Z

205

X-RAYRICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Meszaros,1,2  

E-Print Network [OSTI]

X-RAY­RICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Me´sza´ros,1,2 E. Ramirez-Ruiz,3 M. J of the observational gamma-ray variability-luminosity relation. Subject headings: gamma rays: bursts -- radiation mechanisms: nonthermal 1. INTRODUCTION Gamma-ray burst (GRB) light curves at gamma-ray ener- gies are often

Zhang, Bing

206

VARIABILITY OF SOLAR RADIATION DATA OVER SHORT TIME INTERVALS Frank Vignola  

E-Print Network [OSTI]

radiation values obtained from models utilizing satellite or cloud cover observation data with solarVARIABILITY OF SOLAR RADIATION DATA OVER SHORT TIME INTERVALS Frank Vignola Department of Physics to evaluate satellite and cloud cover models, it is useful to understand the short-term variability of solar

Oregon, University of

207

The pulsation, temperatures and metallicities of Mira and semiregular variables in different stellar systems  

Science Journals Connector (OSTI)

......extension observed in the red, and the combined data...ZA I Large-amplitude red variables. In the present...excluded are supergiant red variables. 1996RAS Royal...licity dependence (Wood 1990), although no evidence...present paper reinvesti- gates this relation, and it......

M. W. Feast

1996-01-01T23:59:59.000Z

208

Observables of Macdonald processes  

E-Print Network [OSTI]

We present a framework for computing averages of various observables of Macdonald processes. This leads to new contour--integral formulas for averages of a large class of multilevel observables, as well as Fredholm determinants for averages of two different single level observables.

Alexei Borodin; Ivan Corwin; Vadim Gorin; Shamil Shakirov

2013-06-04T23:59:59.000Z

209

Methoden Wetenschappelijk and Observational  

E-Print Network [OSTI]

Methoden Wetenschappelijk Onderzoek Fact-free and Observational Science #12;Data · Part of modern science is based on observation ­How do we do this? ­And what are the pitfalls? · Knowing how to observe is an important step in experimental design #12;Three kinds of science · There are (in my view) three ways

Steels, Luc

210

Maximum one-day point rainfall estimation for North Indian plains using district average rainfall ratios  

Science Journals Connector (OSTI)

A quick and simple procedure has been developed for evaluating maximum point rainfall for different return periods for any ... to different return periods. The estimates of point rainfall obtained by this procedu...

O. N. Dhar; A. K. Kulkarni; P. R. Rakhecha

1980-01-01T23:59:59.000Z

211

Delay Analysis of Maximum Weight Scheduling in Wireless Ad Hoc Networks  

E-Print Network [OSTI]

This paper studies delay properties of the well-known maximum weight scheduling algorithm in wireless ad hoc networks. We consider wireless networks with either one-hop or multihop flows. Specifically, this paper shows ...

Modiano, Eytan H.

212

E-Print Network 3.0 - analog fixed maximum Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

SUBGROUPS OF A FREE GROUP Summary: , by the Bestvina-Handel Theorem, and if H has rank exactly n, then H is said to be a maximum-rank 1-auto-fixed... subgroup of F, and...

213

Delineation of the Indo-Malayan Centre of Maximum Marine Biodiversity: The Coral Triangle  

Science Journals Connector (OSTI)

The ranges of many tropical marine species overlap in a centre of maximum marine biodiversity, which is located in the Indo-Malayan ... efforts involve the establishment of a network of Marine Protected Areas (MP...

Bert W. Hoeksema

2007-01-01T23:59:59.000Z

214

Achieving Consistent Maximum Brake Torque with Varied Injection Timing in a DI Diesel Engine  

E-Print Network [OSTI]

, the characteristics of combustion for swept injection timings along the maximum brake torque plateau are determined. The research is conducted by varying injection timing at constant engine speed and load while measuring engine emissions and in-cylinder pressure...

Kroeger, Timothy H

2013-09-19T23:59:59.000Z

215

Wind Mixing and Restratification in a Lake near the Temperature of Maximum Density  

Science Journals Connector (OSTI)

The cooling of a freshwater take provides an opportunity for studying wind mixing and restratification under the peculiar conditions associated with a density maximum. The concepts are explored using a mixing-layer model that incorporates both ...

David M. Farmer; Eddy Carmack

1981-11-01T23:59:59.000Z

216

Investment Options TFLIC Guaranteed Pooled Fund seeks to provide maximum yield  

E-Print Network [OSTI]

Investment Options TFLIC Guaranteed Pooled Fund seeks to provide maximum yield consistent Financial Life Insurance Company (TFLIC) that invests in a diverse pool of high quality fixed: Galliard Capital Management Transamerica Partners Core Bond invests primarily in investment grade debt

Meyers, Steven D.

217

Atlantic Ocean circulation at the last glacial maximum : inferences from data and models  

E-Print Network [OSTI]

This thesis focuses on ocean circulation and atmospheric forcing in the Atlantic Ocean at the Last Glacial Maximum (LGM, 18-21 thousand years before present). Relative to the pre-industrial climate, LGM atmospheric CO? ...

Dail, Holly Janine

2012-01-01T23:59:59.000Z

218

Local origins of interdecadal Pacific variability in the tropical and North Pacific Ocean: evidence from a comparative study of coral oxygen isotope records  

Science Journals Connector (OSTI)

Interdecadal Pacific variability (IPV) is commonly observed in both the tropical and mid-latitude Pacific Ocean, and has a widespread influence on surface climate in the Pan-Pacific Basin. This variability is rec...

Wenfeng Deng; Gangjian Wei

2014-08-01T23:59:59.000Z

219

Heterogeneity-corrected vs -uncorrected critical structure maximum point doses in breast balloon brachytherapy  

SciTech Connect (OSTI)

Recent studies have reported potentially clinically meaningful dose differences when heterogeneity correction is used in breast balloon brachytherapy. In this study, we report on the relationship between heterogeneity-corrected and -uncorrected doses for 2 commonly used plan evaluation metrics: maximum point dose to skin surface and maximum point dose to ribs. Maximum point doses to skin surface and ribs were calculated using TG-43 and Varian Acuros for 20 patients treated with breast balloon brachytherapy. The results were plotted against each other and fit with a zero-intercept line. Max skin dose (Acuros) = max skin dose (TG-43) ? 0.930 (R{sup 2} = 0.995). The average magnitude of difference from this relationship was 1.1% (max 2.8%). Max rib dose (Acuros) = max rib dose (TG-43) ? 0.955 (R{sup 2} = 0.9995). The average magnitude of difference from this relationship was 0.7% (max 1.6%). Heterogeneity-corrected maximum point doses to the skin surface and ribs were proportional to TG-43-calculated doses. The average deviation from proportionality was 1%. The proportional relationship suggests that a different metric other than maximum point dose may be needed to obtain a clinical advantage from heterogeneity correction. Alternatively, if maximum point dose continues to be used in recommended limits while incorporating heterogeneity correction, institutions without this capability may be able to accurately estimate these doses by use of a scaling factor.

Kim, Leonard, E-mail: kimlh@umdnj.edu [Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States); Narra, Venkat; Yue, Ning [Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States)

2013-07-01T23:59:59.000Z

220

Development of two-variable maximum power point tracking control for ocean wave energy converters utilizing a power analysis and data acquisition system.  

E-Print Network [OSTI]

??Ocean wave energy shows great potential as a developing form of renewable energy. However, challenges arise in maturing this technology to achieve cost-effective energy conversion.… (more)

Amon, Ean A.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Development of a weighted-average estimator from a maximum-likelihood estimator and an instrumental-variable estimator in a structural model  

E-Print Network [OSTI]

? 62 S2, (3, 3) where 12??(2) P1M L2S?? 2P1M L2Se? + See S, = 211xx ? 6?S??. Similarly, to estimate the variance of MLl, (2o?'?), ) + ~S . ~) c? g??(, ) (P1ML1) 62 S2 + S 6 ( I) (3. 9) where aeu(1) PCCCL1Suu cue Cr. ?(, ) ? P, Mz, Suu ? 2P, M z... cree(cv) ? Pllv Suu 2P1IV Seu + See The asymptotic covariance of the ML and IV estimators is ACov((b?(a?? 1)) ~ Pccccl, e (b?(a?? 1)) ~ P, rv ) = ? "", (3. 13) Ouu (where ACov is the covariance of the limiting distributions), which is also equal...

Gruben, David Christopher

2012-06-07T23:59:59.000Z

222

Variable pressure operation: An assessment  

SciTech Connect (OSTI)

This report summarizes the benefits, drawbacks, and technical issues of variable pressure operation (VPO) retrofit. Under VPO, turbine throttle pressure is reduced at low loads. This operating mode offers several significant advantages for units that cycle or operate at low loads for extended periods. Information used in the report was assembled from published sources, from major equipment manufacturers, and from utilities operating units under VPO in the US, Europe and Japan. The report also contains statistics of VPO use in this country and abroad. Design features of new units using VPO in Europe and Japan are presented to identify potential directions for future US designs incorporating VPO.

Kimel, E.; Kemeny, P.; Bierman, E.; Lagomarsino, J.; Clarke, D. (Burns and Roe, Inc., Oradell, NJ (USA))

1990-03-01T23:59:59.000Z

223

Section 3.1: Random Variable Section 3.1 introduces the following concept re-  

E-Print Network [OSTI]

random variable problem. 3 #12;Second example of Section 3.1: Example 3.3. on textbook. · Two gas stations. · Let X be the total number of pumps in used. · Let Y be the difference of pumps in used be- tween stations 1 and 2. · Let U be the maximum of the pumps in used. · If the first has 2 in use

Zhang, Tonglin

224

Variable area light reflecting assembly  

DOE Patents [OSTI]

Device is described for tracking daylight and projecting it into a building. The device tracks the sun and automatically adjusts both the orientation and area of the reflecting surface. The device may be mounted in either a wall or roof of a building. Additionally, multiple devices may be employed in a light shaft in a building, providing daylight to several different floors. The preferred embodiment employs a thin reflective film as the reflecting device. One edge of the reflective film is fixed, and the opposite end is attached to a spring-loaded take-up roller. As the sun moves across the sky, the take-up roller automatically adjusts the angle and surface area of the film. Additionally, louvers may be mounted at the light entrance to the device to reflect incoming daylight in an angle perpendicular to the device to provide maximum reflective capability when daylight enters the device at non-perpendicular angles. 9 figs.

Howard, T.C.

1986-12-23T23:59:59.000Z

225

A group bridge approach for variable selection  

Science Journals Connector (OSTI)

......group bridge approach for variable...Actuarial Science, University...Department of Management Science, University...group bridge approach that is capable...group bridge approach for variable...Actuarial Science, University...Department of Management Science......

Jian Huang; Shuange Ma; Huiliang Xie; Cun-Hui Zhang

2009-06-01T23:59:59.000Z

226

Variable-amplitude oscillatory shear response of amorphous materials  

E-Print Network [OSTI]

Variable-amplitude oscillatory shear tests are emerging as powerful tools to investigate and quantify the nonlinear rheology of amorphous solids, complex fluids and biological materials. Quite a few recent experimental and atomistic simulation studies demonstrated that at low shear amplitudes, an amorphous solid settles into an amplitude- and initial conditions-dependent dissipative limit cycle, in which back-and-forth localized particle rearrangements periodically bring the system to the same state. At sufficiently large shear amplitudes, the amorphous system loses memory of the initial conditions, exhibits chaotic particle motions accompanied by diffusive behavior and settles into a stochastic steady-state. The two regimes are separated by a transition amplitude, possibly characterized by some critical-like features. Here we argue that these observations support some of the physical assumptions embodied in the nonequilibrium thermodynamic, internal-variables based, Shear-Transformation-Zone model of amorphous visco-plasticity; most notably that "flow defects" in amorphous solids are characterized by internal states between which they can make transitions, and that structural evolution is driven by dissipation associated with plastic deformation. We present a rather extensive theoretical analysis of the thermodynamic Shear-Transformation-Zone model for a variable-amplitude oscillatory shear protocol, highlighting its success in accounting for various experimental and simulational observations, as well as its limitations. Our results offer a continuum-level theoretical framework for interpreting the variable-amplitude oscillatory shear response of amorphous solids and may promote additional developments.

Nathan Perchikov; Eran Bouchbinder

2014-04-13T23:59:59.000Z

227

Observational learning in horses  

E-Print Network [OSTI]

OBSERVATIONAL LEARNING IN HORSES A Thesis by KATHERINE LOUISE BAER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1979 Major Subject: Animal... Science OBSERVATIONAL LEARNING IN HORSES A Thesis by KATHERINE LOUISE BAER Approved as to style and content by: L7 . 5+~ (Chairma of . C mmittee) ) c r (Mem ) YiNicc CJ ~- (Membeh) (Head of Department May 1979 ABSTRACT Observational...

Baer, Katherine Louise

1979-01-01T23:59:59.000Z

228

Variable Average Absolute Percent Differences  

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

Variable Variable Average Absolute Percent Differences Percent of Projections Over- Estimated Gross Domestic Product Real Gross Domestic Product (Average Cumulative Growth)* (Table 2) 1.0 42.6 Petroleum Imported Refiner Acquisition Cost of Crude Oil (Constant $) (Table 3a) 35.2 18.6 Imported Refiner Acquisition Cost of Crude Oil (Nominal $) (Table 3b) 34.7 19.7 Total Petroleum Consumption (Table 4) 6.2 66.5 Crude Oil Production (Table 5) 6.0 59.6 Petroleum Net Imports (Table 6) 13.3 67.0 Natural Gas Natural Gas Wellhead Prices (Constant $) (Table 7a) 30.7 26.1 Natural Gas Wellhead Prices (Nominal $) (Table 7b) 30.0 27.1 Total Natural Gas Consumption (Table 8) 7.8 70.2 Natural Gas Production (Table 9) 7.1 66.0 Natural Gas Net Imports (Table 10) 29.3 69.7 Coal Coal Prices to Electric Generating Plants (Constant $)** (Table 11a)

229

Variable frequency microwave furnace system  

DOE Patents [OSTI]

A variable frequency microwave furnace system (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency microwave furnace system (10) includes a microwave signal generator (12) or microwave voltage-controlled oscillator (14) for generating a low-power microwave signal for input to the microwave furnace. A first amplifier (18) may be provided to amplify the magnitude of the signal output from the microwave signal generator (12) or the microwave voltage-controlled oscillator (14). A second amplifier (20) is provided for processing the signal output by the first amplifier (18). The second amplifier (20) outputs the microwave signal input to the furnace cavity (34). In the preferred embodiment, the second amplifier (20) is a traveling-wave tube (TWT). A power supply (22) is provided for operation of the second amplifier (20). A directional coupler (24) is provided for detecting the direction of a signal and further directing the signal depending on the detected direction. A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Bible, Don W. (Clinton, TN); Lauf, Robert J. (Oak Ridge, TN)

1994-01-01T23:59:59.000Z

230

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

231

Atomic Collapse Observed  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013 | Tags: Hopper, Materials Science Contact: Linda...

232

Hot Pot Field Observations  

SciTech Connect (OSTI)

Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.

Lane, Michael

2013-06-28T23:59:59.000Z

233

Hot Pot Field Observations  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.

Lane, Michael

234

Instantaneous Measurement of Nonlocal Variables Lev Vaidman  

E-Print Network [OSTI]

Instantaneous Measurement of Nonlocal Variables Lev Vaidman 1 School of Physics and Astronomy variables related to two or more separate sites can be measured instantaneously, except for a finite time of the measurement. It is a verification measurement: it yields reliably the eigenvalues of the nonlocal variables

Vaidman, Lev

235

Switching characteristics and maximum repetitive frequency of InGaAsP/InP bistable injection lasers  

SciTech Connect (OSTI)

Switching characteristics of nonuniformly pumped InGaAsP/InP BH Structure bistable lasers are investigated both experimentally and theoretically. First observation of automatic turn-on phenomenon was made, which is found to be a random process. For repetitive operation, turn-on delay time and necessary duration of switch-off pulse practically limited the maximum repetitive frequency. For ''switch-on,'' triggering the saturable absorption region is more effective. For reducing the minimum switch-off pulse width, either higher doping or reverse biasing at the absorption region is recommended. Tradeoff relation of OFF pulse width with threshold current and stable operation are discussed. With some improvements in device parameters, bistable operation at repetitive frequency over 1 GHz is expected.

Liu, H.F.; Hashimoto, Y.; Kamiya, T.

1988-01-01T23:59:59.000Z

236

Global Lightning Observations  

E-Print Network [OSTI]

Flash Rate Global distribution of lightning from a combined nine years of observations of the NASA OTDGlobal Lightning Observations #12;Optical Transient Detector ( launched April, 1995 ) Lightning Imaging Sensor ( launched November, 1997 ) Lightning Detection from Low Earth Orbit #12;LIS on TRMM #12

California at Berkeley, University of

237

On the maximum value of the cosmic abundance of oxygen and the oxygen yield  

E-Print Network [OSTI]

We search for the maximum oxygen abundance in spiral galaxies. Because this maximum value is expected to occur in the centers of the most luminous galaxies, we have constructed the luminosity - central metallicity diagram for spiral galaxies, based on a large compilation of existing data on oxygen abundances of HII regions in spiral galaxies. We found that this diagram shows a plateau at high luminosities (-22.3 oxygen abundance 12+log(O/H) ~ 8.87. This provides strong evidence that the oxygen abundance in the centers of the most luminous metal-rich galaxies reaches the maximum attainable value of oxygen abundance. Since some fraction of the oxygen (about 0.08 dex) is expected to be locked into dust grains, the maximum value of the true gas+dust oxygen abundance in spiral galaxies is 12+log(O/H) ~ 8.95. This value is a factor of ~ 2 higher than the recently estimated solar value. Based on the derived maximum oxygen abundance in galaxies, we found the oxygen yield to be about 0.0035, depending on the fraction of oxygen incorporated into dust grains.

L. S. Pilyugin; T. X. Thuan; J. M. Vilchez

2007-01-11T23:59:59.000Z

238

Variable White Dwarf Data Tables  

SciTech Connect (OSTI)

Below, I give a brief explanation of the information in these tables. In all cases, I list the WD {number_sign}, either from the catalog of McCook {ampersand} Sion (1987) or determined by me from the epoch 1950 coordinates. Next, I list the most commonly used name (or alias), then I list the variable star designation if it is available. If not, I list the constellation name and a V** or?? depending on what the last designated variable star for that constellation is. I present epoch 2000 coordinates for all of the stars, which I precessed from the 1950 ones in most cases. I do not include proper motion effects; this is negligible for all except the largest proper motion DAV stars, such as L 19-2, BPM 37093, B 808, and G 29-38. Even in these cases, the error is no more than 30` in declination and 2 s in right ascension. I culled effective temperatures from the latest work (listed under each table); they are now much more homogeneous than before. I pulled the magnitude estimates from the appropriate paper, and they are mean values integrated over several cycles. The amplitude given is for the height of a typical pulse in the light curve. The periods correspond the dominant ones found in the light curve. In some cases, there is a band of power in a given period range, or the light curve is very complex, and I indicate this in the table. In the references, I generally list the paper with the most comprehensive pulsation analysis for the star in question. In some cases, there is more than one good reference, and I list them as well.

Bradley, P. A.

1997-12-31T23:59:59.000Z

239

Estimating the maximum potential revenue for grid connected electricity storage : arbitrage and regulation.  

SciTech Connect (OSTI)

The valuation of an electricity storage device is based on the expected future cash ow generated by the device. Two potential sources of income for an electricity storage system are energy arbitrage and participation in the frequency regulation market. Energy arbitrage refers to purchasing (stor- ing) energy when electricity prices are low, and selling (discharging) energy when electricity prices are high. Frequency regulation is an ancillary service geared towards maintaining system frequency, and is typically procured by the independent system operator in some type of market. This paper outlines the calculations required to estimate the maximum potential revenue from participating in these two activities. First, a mathematical model is presented for the state of charge as a function of the storage device parameters and the quantities of electricity purchased/sold as well as the quantities o ered into the regulation market. Using this mathematical model, we present a linear programming optimization approach to calculating the maximum potential revenue from an elec- tricity storage device. The calculation of the maximum potential revenue is critical in developing an upper bound on the value of storage, as a benchmark for evaluating potential trading strate- gies, and a tool for capital nance risk assessment. Then, we use historical California Independent System Operator (CAISO) data from 2010-2011 to evaluate the maximum potential revenue from the Tehachapi wind energy storage project, an American Recovery and Reinvestment Act of 2009 (ARRA) energy storage demonstration project. We investigate the maximum potential revenue from two di erent scenarios: arbitrage only and arbitrage combined with the regulation market. Our analysis shows that participation in the regulation market produces four times the revenue compared to arbitrage in the CAISO market using 2010 and 2011 data. Then we evaluate several trading strategies to illustrate how they compare to the maximum potential revenue benchmark. We conclude with a sensitivity analysis with respect to key parameters.

Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.

2012-12-01T23:59:59.000Z

240

Carbonization of Coal Evaluation of Effects of Rate of Heating and of Maximum Temperature on Pyrolysis of a Coking Coal  

Science Journals Connector (OSTI)

Carbonization of Coal Evaluation of Effects of Rate of Heating and of Maximum Temperature on Pyrolysis of a Coking Coal ...

William B. Warren

1935-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Visual Observability of the Cassiopeia A Supernova  

E-Print Network [OSTI]

It is generally believed that the explosion which gave birth to the Cassiopeia A supernova remmant resulted from core collapse of a hydrogen-deficient star. A progenitor that has lost all its hydrogen envelope and part of its helium envelope would lead to an explosion with the optical properties of a Type Ic supernova. There is evidence, if not general agreement, that Flamsteed observed the Cas A supernova as a sixth magnitude object in August, 1680. If an explosion with a typical SNIc light curve at the position and distance of Cas A attained maximum luminosity during the winter of 1679-1680, it would at that time have been poorly situated for visual observation, as its upper culmination would have taken place during daylight, while in August, between 170-200 days after peak luminosity, it would have been a sixth magnitude star.

J. A. Morgan

2007-10-11T23:59:59.000Z

242

On the Vertical Decay Rate of the Maximum Tangential Winds in Tropical Cyclones DANIEL P. STERN* AND DAVID S. NOLAN  

E-Print Network [OSTI]

On the Vertical Decay Rate of the Maximum Tangential Winds in Tropical Cyclones DANIEL P. STERN independent of both the maximum wind speed and the radius of maximum winds (RMW). This can be seen winds change with height. Above 2-km height, vertical profiles of Vmaxnorm are nearly independent

Nolan, David S.

243

Integral variable structure current control of DFIG-based wind turbines near cut-in speed  

Science Journals Connector (OSTI)

Based on the grid voltage orientated vector control technique, a novel integral variable structure controller for current control of variable speed doubly fed induction generator (DFIG) wind turbines near cut-in wind speed is proposed. The proposed current controller can not only ensure generators' safe cut-in switches to the grid, but also maximum energy capture after switch motion without any regulations. By these, simulations of a 1.5 MW DFIG-based wind turbine near cut-in wind speed are separately conducted under integral variable structure control (IVSC) and PI control. The results show that IVSC strategy, which gives better dynamic response, less static error, smaller controller output dithering, stronger global robustness against generator parameters uncertainty and the grid voltage fluctuation, as well as needless controller regulation after cutting-in the grid, obviously preponderates over traditional PI control for DFIG-based wind turbines near cut-in speed.

Changliang Xia; Huimin Wang; Zhanfeng Song

2009-01-01T23:59:59.000Z

244

Dark matter interacts with variable vacuum energy  

E-Print Network [OSTI]

We investigate a spatially flat Friedmann-Robertson-Walker (FRW) scenario with two interacting components, dark matter and variable vacuum energy (VVE) densities, plus two decoupled components, one is a baryon term while the other behaves as a radiation component. We consider a linear interaction in the derivative dark component density. We apply the $\\chi^2$ method to the observational Hubble data for constraining the cosmological parameters and analyze the amount of dark energy in the radiation era for the model. It turns out that our model fulfills the severe bound of $\\Omega_{x}(z\\simeq 1100)measurements from Planck survey, the future constraints achievable by Euclid and CMBPol experiments, reported for the behavior of the dark energy at early times, and fulfills the stringent bound $\\Omega_{x}(z\\simeq 10^{10})<0.04$ at $2\\sigma$ level in the big-bang nucleosynthesis epoch. We also examine the cosmic age problem at high redshift associated with the old quasar APM 08279+5255 and estimate the age of the universe today.

Iván E. Sánchez G

2014-05-06T23:59:59.000Z

245

Maximum-entropy meshfree method for nonlinear static analysis of planar reinforced concrete structures  

E-Print Network [OSTI]

the nonlinear system of equations. Maximum-entropy basis functions are used to discretize the two displacement control method is implemented to solve the nonlinear system of equations and to obtain tools in the field of structural engineering, Yaw and co-workers [1] presented a blended FE and meshfree

Sukumar, N.

246

Magnetofossil spike during the Paleocene-Eocene thermal maximum: Ferromagnetic resonance, rock magnetic, and electron microscopy  

E-Print Network [OSTI]

Magnetofossil spike during the Paleocene-Eocene thermal maximum: Ferromagnetic resonance, rock,2 Timothy D. Raub,3,4 Dirk Schumann,5 Hojatollah Vali,5 Alexei V. Smirnov,3,6 and Joseph L. Kirschvink1 controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR

247

Maximum late Holocene extent of the western Greenland Ice Sheet during the late 20th century  

E-Print Network [OSTI]

the 20th century. This suggests a lagged ice-margin response to prior cooling, such as the Little Ice AgeMaximum late Holocene extent of the western Greenland Ice Sheet during the late 20th century Samuel Keywords: Greenland Ice Sheet Little Ice Age 10 Be exposure dating Ice-dammed lake Lake sediment core a b

Briner, Jason P.

248

Sufficient Stochastic Maximum Principle in a Regime-Switching Diffusion Model  

SciTech Connect (OSTI)

We prove a sufficient stochastic maximum principle for the optimal control of a regime-switching diffusion model. We show the connection to dynamic programming and we apply the result to a quadratic loss minimization problem, which can be used to solve a mean-variance portfolio selection problem.

Donnelly, Catherine, E-mail: C.Donnelly@hw.ac.uk [Heriot-Watt University, Department of Actuarial Mathematics and Statistics (United Kingdom)

2011-10-15T23:59:59.000Z

249

SAWSA-LPR: Astochastic search strategy for estimation of maximum likelihood DNA phylogenetic trees  

Science Journals Connector (OSTI)

In the spirit of the ''grand challenge'', this paper covers the development of novel concepts for inference of large phylogenies based on the maximum likelihood method, which has proved to be the most accurate model for inference of huge and complex ... Keywords: DNA, Inferencing, LPR, Phylogenetic tree, Simulated annealing

Sanchita Paul, Gadadhar Sahoo

2014-05-01T23:59:59.000Z

250

On the maximum and minimum mass of protoneutron stars in the Brueckner theory  

E-Print Network [OSTI]

We study the structure of protoneutron stars within the finite-temperature Brueckner-Bethe-Goldstone theoretical approach, paying particular attention to the joining with a low-density nuclear equation of state (EOS). We find a slight sensitivity of the minimum value of the protoneutron star mass on the low-density EOS, whereas the maximum mass is hardly affected.

Burgio, G F

2010-01-01T23:59:59.000Z

251

Maximum Feedrate Interpolator for Multi-axis CNC Machining with Jerk Constraints  

E-Print Network [OSTI]

Maximum Feedrate Interpolator for Multi-axis CNC Machining with Jerk Constraints X. Beudaert, S name@lurpa.ens-cachan.fr Abstract A key role of the CNC is to perform the feedrate interpolation which for the next point along the path is computed. Examples and comparisons with an industrial CNC demonstrate

Paris-Sud XI, Université de

252

Ocean Circulation During the Last Glacial Maximum Simulated by PMIP3 Climate Models  

E-Print Network [OSTI]

in the intensity of the Atlantic Overturning Circulation (distinguished by the local maximum at approximately 30 N %. In the plot corresponding to the World Ocean Circulation, an increase in the Deep Circulation, associated of the water masses as well as the impact on ocean carbon storage. References: [1] Godfrey J. S., Geophysics

Schmittner, Andreas

253

Environmental and Ecological Statistics 10, 455467, 2003 Moment and maximum likelihood  

E-Print Network [OSTI]

Environmental and Ecological Statistics 10, 455±467, 2003 Moment and maximum likelihood estimators are probability proportional to size methods. These methods are also referred to as size-biased because sampling are special cases of size-biased sampling where the probability weighting comes from a lineal or areal

254

Towards a frequency-dependent discrete maximum principle for the implicit Monte Carlo equations  

SciTech Connect (OSTI)

It has long been known that temperature solutions of the Implicit Monte Carlo (IMC) equations can exceed the external boundary temperatures, a so-called violation of the 'maximum principle.' Previous attempts at prescribing a maximum value of the time-step size {Delta}{sub t} that is sufficient to eliminate these violations have recommended a {Delta}{sub t} that is typically too small to be used in practice and that appeared to be much too conservative when compared to numerical solutions of the IMC equations for practical problems. In this paper, we derive a new estimator for the maximum time-step size that includes the spatial-grid size {Delta}{sub x}. This explicitly demonstrates that the effect of coarsening {Delta}{sub x} is to reduce the limitation on {Delta}{sub t}, which helps explain the overly conservative nature of the earlier, grid-independent results. We demonstrate that our new time-step restriction is a much more accurate means of predicting violations of the maximum principle. We discuss how the implications of the new, grid-dependent timestep restriction can impact IMC solution algorithms.

Wollaber, Allan B [Los Alamos National Laboratory; Larsen, Edward W [Los Alamos National Laboratory; Densmore, Jeffery D [Los Alamos National Laboratory

2010-12-15T23:59:59.000Z

255

Maximum Class Separability for Rough-Fuzzy C-Means Based Brain MR Image Segmentation  

E-Print Network [OSTI]

Maximum Class Separability for Rough-Fuzzy C-Means Based Brain MR Image Segmentation Pradipta Maji of brain MR images. The RFCM algorithm comprises a judicious integration of the of rough sets, fuzzy sets with vagueness and incompleteness in class definition of brain MR images, the membership function of fuzzy sets

Pal, Sankar Kumar

256

Maximum Utility Product Pricing Models and Algorithms Based on Reservation Prices  

E-Print Network [OSTI]

Maximum Utility Product Pricing Models and Algorithms Based on Reservation Prices R. Shioda L. Tun for pricing a product line with several customer segments under the assumption that customers' product choices utility model and formulate it as a mixed-integer programming problem, design heuristics and valid cuts

Tunçel, Levent

257

Self-Assembly for Maximum Yields Under Constraints Michael J. Fox and Jeff S. Shamma  

E-Print Network [OSTI]

Self-Assembly for Maximum Yields Under Constraints Michael J. Fox and Jeff S. Shamma Abstract-- We present an algorithm that, given any target tree, synthesizes reversible self-assembly rules that provide states that cannot be recovered from the unlabeled graph. I. INTRODUCTION Self-assembly is the phenomenon

Shamma, Jeff S.

258

Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture  

E-Print Network [OSTI]

Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture Stefano Accepted 26 September 2013 Available online 9 October 2013 Keywords: Optimization Photosynthesis Soil moisture Stomatal conductance Transpiration a b s t r a c t Optimization theories explain a variety

Katul, Gabriel

259

Power and Sample Size Determination for a Stepwise Test Procedure for Finding the Maximum Safe Dose  

E-Print Network [OSTI]

Power and Sample Size Determination for a Stepwise Test Procedure for Finding the Maximum Safe Dose This paper addresses the problem of power and sample size calculation for a stepwise multiple test procedure of a compound. A general expression for the power of this procedure is derived. It is used to find the minimum

Tamhane, Ajit C.

260

Generalized Local Maximum Principles for Finite-Difference Operators Author(s): Achi Brandt  

E-Print Network [OSTI]

Generalized Local Maximum Principles for Finite-Difference Operators Author(s): Achi Brandt Source://www.jstor.org/action/showPublisher?publisherCode=ams. . Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars

Note: This page contains sample records for the topic "maximum variable observations" 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

Design of wind farm layout for maximum wind energy capture Andrew Kusiak*, Zhe Song  

E-Print Network [OSTI]

Design of wind farm layout for maximum wind energy capture Andrew Kusiak*, Zhe Song Intelligent sources of alternative energy. The construction of wind farms is destined to grow in the U.S., possibly twenty-fold by the year 2030. To maximize the wind energy capture, this paper presents a model for wind

Kusiak, Andrew

262

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone  

E-Print Network [OSTI]

0 Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated) viewed as a heat engine converts heat energy extracted from the ocean to kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while

Wang, Yuqing

263

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone*  

E-Print Network [OSTI]

Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated as a heat engine converts heat energy extracted from the ocean into the kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while

Wang, Yuqing

264

THE SECOND LAW OF THERMODYNAMICS AND THE GLOBAL CLIMATE SYSTEM: A REVIEW OF THE MAXIMUM  

E-Print Network [OSTI]

THE SECOND LAW OF THERMODYNAMICS AND THE GLOBAL CLIMATE SYSTEM: A REVIEW OF THE MAXIMUM ENTROPY of the global climate system and those of turbulent fluid systems are reviewed from a thermodynamic viewpoint production, energetics Citation: Ozawa, H., A. Ohmura, R. D. Lorenz, and T. Pujol, The second law

Lorenz, Ralph D.

265

Integrating ecophysiology and plankton dynamics into projected changes in maximum fisheries catch potential under climate  

E-Print Network [OSTI]

). In addition, average surface water pH of the ocean has dropped by 0.1 units since pre- industrial timesIntegrating ecophysiology and plankton dynamics into projected changes in maximum fisheries catch 7TJ, UK 2 Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft

Pauly, Daniel

266

Accurate Single Molecule FRET Efficiency Determination for Surface Immobilized DNA Using Maximum Likelihood Calculated Lifetimes  

E-Print Network [OSTI]

Accurate Single Molecule FRET Efficiency Determination for Surface Immobilized DNA Using MaximumVed: October 4, 2006; In Final Form: January 12, 2007 Single molecule fluorescent lifetime trajectories directly measured using time-tagged single-photon counting and scanning confocal microscopy. A modified

267

A PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM  

E-Print Network [OSTI]

in the context of eigen- value optimization, and [8] gives an overview of the history. The bases for the presentA PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM EIGENVALUE function, semi-infinite problem, H-norm. 1. Introduction. Proximity control for bundle methods has been

Noll, Dominikus

268

A PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM  

E-Print Network [OSTI]

in the context of eigen- value optimization, and [9] gives an overview of the history. The bases for the presentA PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM EIGENVALUE function, semi-infinite problem, H-norm. 1. Introduction. Proximity control for bundle methods has been

Noll, Dominikus

269

Variable path length spectrophotometric probe  

DOE Patents [OSTI]

A compact, variable pathlength, fiber optic probe for spectrophotometric measurements of fluids in situ. The probe comprises a probe body with a shaft having a polished end penetrating one side of the probe, a pair of optic fibers, parallel and coterminous, entering the probe opposite the reflecting shaft, and a collimating lens to direct light from one of the fibers to the reflecting surface of the shaft and to direct the reflected light to the second optic fiber. The probe body has an inlet and an outlet port to allow the liquid to enter the probe body and pass between the lens and the reflecting surface of the shaft. A linear stepper motor is connected to the shaft to cause the shaft to advance toward or away from the lens in increments so that absorption measurements can be made at each of the incremental steps. The shaft is sealed to the probe body by a bellows seal to allow freedom of movement of the shaft and yet avoid leakage from the interior of the probe.

O'Rourke, Patrick E. (157 Greenwood Dr., Martiney, GA 30907); McCarty, Jerry E. (104 Recreation Dr., Aiken, SC 29803); Haggard, Ricky A. (1144 Thornwood Drive, North Augusta, SC 29891)

1992-01-01T23:59:59.000Z

270

Definition: Variable Peak Pricing | Open Energy Information  

Open Energy Info (EERE)

Variable Peak Pricing Variable Peak Pricing Jump to: navigation, search Dictionary.png Variable Peak Pricing Variable Peak Pricing (VPP) is a hybrid of time-of-use and real-time pricing where the different periods for pricing are defined in advance (e.g., on-peak=6 hours for summer weekday afternoon; off-peak= all other hours in the summer months), but the price established for the on-peak period varies by utility and market conditions.[1] Related Terms real-time pricing References ↑ https://www.smartgrid.gov/category/technology/variable_peak_pricing [[C LikeLike UnlikeLike You like this.Sign Up to see what your friends like. ategory: Smart Grid Definitionssmart grid,off-peak,on-peak,smart grid, |Template:BASEPAGENAME]]smart grid,off-peak,on-peak,smart grid, Retrieved from "http://en.openei.org/w/index.php?title=Definition:Variable_Peak_Pricing&oldid=50262

271

Variable-Period Undulators for Synchrotron Radiation  

SciTech Connect (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

272

Multivector Functions of a Real Variable  

E-Print Network [OSTI]

This paper is an introduction to the theory of multivector functions of a real variable. The notions of limit, continuity and derivative for these objects are given. The theory of multivector functions of a real variable, even being similar to the usual theory of vector functions of a real variable, has some subtle issues which make its presentation worhtwhile.We refer in particular to the derivative rules involving exterior and Clifford products, and also to the rule for derivation of a composition of an ordinary scalar function with a multivector function of a real variable.

A. M. Moya; V. V. Fernández; W. A. Rodrigues Jr

2002-12-17T23:59:59.000Z

273

Hybrid Bayesian Networks with Linear Deterministic Variables  

E-Print Network [OSTI]

Conference (UAI-05), 2005, AUAI Press, Arlington, VA. 136 Y X Z Figure 2: A Bayesian Network Representation of the Mixed Distribution for X. this example, Y is a discrete variable with state space ? Y = {1,2,3}, Z is a real-valued variable, and X is a... conditionally deterministic variable whose condi- tional distribution is described as follows: X |{y,z} = y if y =1,2 and X |{y,z} = z if y =3. Potentials of the type described above are used in this paper to represent distributions of variables in hy- brid...

Cobb, Barry R.; Shenoy, Prakash P.

2005-07-01T23:59:59.000Z

274

Integrating Variable Renewable Energy: Challenges and Solutions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Integrating Variable Renewable Energy: Challenges and Solutions L. Bird, M. Milligan, and D. Lew National Renewable Energy Laboratory Technical Report NRELTP-6A20-60451 September...

275

A coral-based reconstruction of Intertropical Convergence Zone variablity over Central America since 1707  

SciTech Connect (OSTI)

Seasonal movements of the Intertropical Convergence Zone (ITCZ) control precipitation patterns and cloud cover throughout the tropics. In this study the authors have reconstructed seasonal and interannual variability of the eastern Pacific ITCZ from 1984 to 1707 using subseasonal {delta}{sup 18}O analyses on a massive coral from Secas Island (7{degrees}59{prime}N, 82{degrees}3{prime}W) in the Gulf of Chiriqui, Panama. The land area that drains into the Gulf of Chiriqui has served to amplify the rainfall effect on nearshore surface waters and coral {delta}{sup 18}O{sub ppt} composition. During the protracted wet season in Panama, the {delta}{sup 18}O of precipitation ({delta}{sup 18}O{sub ppt}) is reduced on average by 10{per_thousand} and sea surface salinity (SSS) along the western coast is reduced up to 11{per_thousand}. Calibration of the coral {delta}{sup 18}O{sub ppt} from Secas Island against instrumental sea surface temperature (SST), SSS, precipitation and {delta}{sup 18}O{sub ppt} data indicate that seasonal rainfall induced variations in seawater {delta}{sup 18}O are responsible for {approximately}80% of the annual {delta}{sup 18}O variance. The regularity of the reconstructed seasonal ITCZ cycle indicates that over the length of the record the zone of maximum rainfall in the eastern Pacific has always expanded north to at least Panama in every northern hemisphere summer. Significant interannual and interdecadal {delta}{sup 18}O oscillations occur at average periods near 9, 3-7 (ENSO band), 17 and 33 years (listed in order of decreasing variance). As the Gulf of Chiriqui coral {delta}{sup 18}O time series is the first paleoclimatic record of past variations in the ITCZ, other seasonal-resolution reconstructions of the past behavior of the ITCZ are required to test whether the interannual and long-term variability observed in the eastern Pacific ITCZ is more than regional in scale. 79 refs., 13 figs., 2 tabs.

Linsley, B.K.; Dunbar, R.B.; Mucciarone, D.A. [Rice Univ., Houston, TX (United States)] [Rice Univ., Houston, TX (United States); Wellington, G.M. [Univ. of Houston, TX (United States)] [and others] [Univ. of Houston, TX (United States); and others

1994-05-15T23:59:59.000Z

276

Experimental observations of deformation caused by mineral dissolution in variable-aperture fractures  

E-Print Network [OSTI]

are further influenced by stresses in the host rock. To quantitatively explore these coupled processes, we-water reactions. For example, subsurface CO2 sequestration in depleted oil and gas reservoirs or deep saline 1 August 2008. [1] Problems such as CO2 sequestration, petroleum production and nuclear waste

Detwiler, Russell

277

Observed 20th century desert dust variability: impact on climate and biogeochemistry  

E-Print Network [OSTI]

2010 in southern South America? ”, Geophys. Res. Lett. , 35,where in southern South America? ”, Geophys. Res. Lett. ,and desertification in South America, P. Natl. Acad. Sci. ,

2010-01-01T23:59:59.000Z

278

Mexican drought: an observational modeling and tree ring study of variability and climate change  

E-Print Network [OSTI]

America and northern South America. (In the annual mean theAmerica and northern South America. This pattern appearsMéxico and northern South America, a pattern that is again

2009-01-01T23:59:59.000Z

279

Multiple linear regression: fixed and multinormal data with missing observations among the independent variables  

E-Print Network [OSTI]

) b 23 + W ( 3)b E (W'(x3) El b2 + W" (x3 E) b" ) 3 " ' "3 23 E (W (x ) + W (x ))B2 x3 '23 (3. 21) since W'(x ) + W" (x ) = l. 3 3 It should also be noted that if any group j (except 0) is not large enough to provide regression estimates... of The General Solution or that found in the previous section) from each of the t groups. Let b represent the estimate of B from the t-th group. Then an i estimate of the variance of b is found by the equation k Var(b)- E ( b -b ) /k 1 t i i k k . E t~l (3...

Johnston, Walter Edward

1965-01-01T23:59:59.000Z

280

Observed Variability of Ocean Wave Stokes Drift, and the Eulerian Response to Passing Groups  

E-Print Network [OSTI]

­current interactions are also considered important in generating and maintaining Langmuir circulation (LC), a prominent 2005, in final form 13 September 2005) ABSTRACT Waves and currents interact via exchanges of mass with current theory. 1. Introduction Surface waves are of central importance in general to air­sea interactions

Smith, Jerome A.

Note: This page contains sample records for the topic "maximum variable observations" 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

On the Variability Coherence Observed in Black Hole Candidates at Different XRay Energies  

E-Print Network [OSTI]

a powerful mathematical method to estimate the coherence function (Bendat & Piersol 1986), they demonstrated thermal waves on an accretion disk (Manmoto et al. 1996), at 1 Department of Astronomy & Astrophysics, G¨oteborg University and Chalmers University of Technology, S­412 96 G¨oteborg, Sweden 2 Nordita, Copenhagen, Denmark 3

Wiita, Paul J.

282

Mexican drought: an observational modeling and tree ring study of variability and climate change  

E-Print Network [OSTI]

by the state of the tropical Pacific Ocean with the Atlantical. (2005b). 1. POGA (Pacific Ocean-Global Atmosphere): Inoutside of the tropical Pacific Ocean that computes SST

2009-01-01T23:59:59.000Z

283

Mexican drought: an observational modeling and tree ring study of variability and climate change  

E-Print Network [OSTI]

2007. Expansion of the Hadley Cell under global warming.poleward expansion of the Hadley Cell and poleward movement

2009-01-01T23:59:59.000Z

284

Effects of excess rainfall on the temporal variability of observed peak-discharge power laws  

E-Print Network [OSTI]

, University of Colorado, Boulder, CO, USA b Colorado Research Associates (CoRa)/Northwest Research Associates (NWRA), 3380 Mitchell Lane, Boulder, CO 80301, USA c Department of Civil and Environmental Engineering, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA

Furey, Peter R.

285

On the observed variability of the crosspolar cap potential W. A. Bristow,1  

E-Print Network [OSTI]

. Introduction [2] The cross­polar cap potential (PCP) parameterizes the degree to which solar wind energy

Shepherd, Simon

286

Climate Extremes in the Southeast United States: Observed Variability, Spatial Classification, and Related Planning.  

E-Print Network [OSTI]

??Spatial and temporal trends in temperature and precipitation extremes were investigated for the Southeast United States for the period 1948 to 2012 using 27 extreme… (more)

Powell, Emily J.

2014-01-01T23:59:59.000Z

287

EBONEEUROPEAN BIODIVERSITY OBSERVATION NETWORK  

E-Print Network [OSTI]

EBONEEUROPEAN BIODIVERSITY OBSERVATION NETWORK Geert De Blust, Guy Laurijssens, Hans Van Calster of biodiversity monitoring through close collaboration of users and data providers #12;#12;Design of a monitoring-effectiveness Optimization of biodiversity monitoring through close collaboration of users and data providers Geert De Blust1

288

Long-Period Solar Variability  

SciTech Connect (OSTI)

Terrestrial climate records and historical observations of the Sun suggest that the Sun undergoes aperiodic oscillations in radiative output and size over time periods of centuries and millenia. Such behavior can be explained by the solar convective zone acting as a nonlinear oscillator, forced at the sunspot-cycle frequency by variations in heliomagnetic field strength. A forced variant of the Lorenz equations can generate a time series with the same characteristics as the solar and climate records. The timescales and magnitudes of oscillations that could be caused by this mechanism are consistent with what is known about the Sun and terrestrial climate.

GAUTHIER,JOHN H.

2000-07-20T23:59:59.000Z

289

Hidden variables or hidden theories?  

E-Print Network [OSTI]

We show that a modified Relativity Principle could explain in a "classical" way the strange correlations of entangled photons. We propose a gedanken experiment with balls and boxes that predicts the same distribution of probability of the Quantum Mechanics in the case of the EPR experiment with a pair of entangled photons meeting a pair of polarizers. In the light of this gedanken experiment, we find an alternative description of the real EPR experiment postulating the existence of two observers (one for each polarizer) embedded in two locally anisotropic spacetimes. In our model there is no need to invoke quantum non separability or instantaneous action at distance.

A. Feoli

2006-09-08T23:59:59.000Z

290

GD 552: a cataclysmic variable with a brown dwarf companion?  

E-Print Network [OSTI]

GD 552 is a high proper motion star with the strong, double-peaked emission lines characteristic of the dwarf nova class of cataclysmic variable star, and yet no outburst has been detected during the past 12 years of monitoring. We present spectroscopy taken with the aim of detecting emission from the mass donor in this system. We fail to do so at a level which allows us to rule out the presence of a near-main-sequence star donor. Given GD 552's orbital period of 103 minutes, this suggests that it is either a system that has evolved through the ~80-minute orbital period minimum of cataclysmic variable stars and now has a brown dwarf mass donor, or that has formed with a brown dwarf donor in the first place. This model explains the low observed orbital velocity of the white dwarf and GD 552's low luminosity. It is also consistent with the absence of outbursts from the system.

E. Unda-Sanzana; T. R. Marsh; B. T. Gansicke; P. F. L. Maxted; L. Morales-Rueda; V. S. Dhillon; T. D. Thoroughgood; E. Tremou; C. A. Watson; R. Hinojosa-Goni

2008-06-30T23:59:59.000Z

291

Time series data mining for the Gaia variability analysis  

E-Print Network [OSTI]

Gaia is an ESA cornerstone mission, which was successfully launched December 2013 and commenced operations in July 2014. Within the Gaia Data Processing and Analysis consortium, Coordination Unit 7 (CU7) is responsible for the variability analysis of over a billion celestial sources and nearly 4 billion associated time series (photometric, spectrophotometric, and spectroscopic), encoding information in over 800 billion observations during the 5 years of the mission, resulting in a petabyte scale analytical problem. In this article, we briefly describe the solutions we developed to address the challenges of time series variability analysis: from the structure for a distributed data-oriented scientific collaboration to architectural choices and specific components used. Our approach is based on Open Source components with a distributed, partitioned database as the core to handle incrementally: ingestion, distributed processing, analysis, results and export in a constrained time window.

Nienartowicz, Krzysztof; Guy, Leanne; Holl, Berry; Lecoeur-Taďbi, Isabelle; Mowlavi, Nami; Rimoldini, Lorenzo; Ruiz, Idoia; Süveges, Maria; Eyer, Laurent

2014-01-01T23:59:59.000Z

292

Deutsch-Jozsa algorithm for continuous variables  

E-Print Network [OSTI]

We present an idealized quantum continuous variable analog of the Deutsch-Jozsa algorithm which can be implemented on a perfect continuous variable quantum computer. Using the Fourier transformation and XOR gate appropriate for continuous spectra we show that under ideal operation to infinite precision that there is an infinite reduction in number of query calls in this scheme.

Arun K. Pati; Samuel L. Braunstein

2002-07-18T23:59:59.000Z

293

Quantum Computing and Hidden Variables Scott Aaronson #  

E-Print Network [OSTI]

Quantum Computing and Hidden Variables Scott Aaronson # Institute for Advanced Study, Princeton of a hidden variable, then we could e#ciently solve problems that are believed to be intractable even powerful than the quantum computing model. PACS numbers: 03.65.Ta, 03.65.Ud, 03.67.Lx, 02.70.­c I

Aaronson, Scott

294

Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment  

E-Print Network [OSTI]

Solar Dynamics Observatory/ EVE Extreme Ultraviolet Variability Experiment Frequently Asked and model solar extreme ultraviolet irradiance variations due to solar flares, solar rotation, and solar and structure of the Sun. What is solar variability? Solar radiation varies on all time scales ranging from

Mojzsis, Stephen J.

295

A Search for Fast X-ray Variability from Active Galactic Nuclei using Swift  

E-Print Network [OSTI]

Blazars are a class of active galactic nuclei (AGNs) known for their very rapid variabilty in the high energy regions of the electromagnetic spectrum. Despite this known fast variability, X-ray observations have generally not revealed variability in blazars with rate doubling or halving timescales less than approximately 15 min. Since its launch, the Swift X-ray Telescope has obtained 0.2-10 keV X-ray data on 143 AGNs, including blazars, through intense target of opportunity observations that can be analyzed in a multiwavelength context and used to model jet parameters, particularly during flare states. We have analyzed this broad Swift data set in a search for short timescale variability in blazars that could limit the size of the emission region in the blazar jet. While we do find several low-significance possible flares with potential indications of rapid variability, we find no strong evidence for rapid ($energy band for the AGNs analy...

Pryal, Matthew; Stroh, Michael

2015-01-01T23:59:59.000Z

296

Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations  

SciTech Connect (OSTI)

Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulations in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity, for both inter-model deviation and model-measurement discrepancy. Our intercomparisons of three CF or sky-cover related dataset reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and the inter-model deviations have a similar magnitude for the total CF (TCF) and the normalized cloud effect, and they are twice as large as the surface downward solar radiation and cloud transmissivity. This implies that the other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that a better agreement among the GCMs in solar radiative fluxes could be the result of compensating errors in either cloud vertical structure, cloud optical depth or cloud fraction. Similar deviation pattern between inter-model and model-measurement suggests that the climate models tend to generate larger bias against observations for those variables with larger inter-model deviation. The simulated TCF from IPCC AR4 GCMs are very scattered through all seasons over three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at Manus and NSA in simulating the seasonal variation and probability distribution of TCF; however, the TCF in these models is remarkably underpredicted and cloud transmissivity is less susceptible to the change of TCF than the observed at SGP. Much larger inter-model deviation and model bias are found over NSA than the other sites in estimating the TCF, cloud transmissivity and cloud-radiation interaction, suggesting that the Arctic region continues to challenge cloud simulations in climate models. Most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels in the tropics. The high altitude CF is much larger in the GCMs than the observation and the inter-model variability of CF also reaches maximum at high levels in the tropics. Most of the GCMs tend to underpredict CF by 50-150% relative to the measurement average at low and middle levels over SGP. While the GCMs generally capture the maximum CF in the boundary layer and vertical variability, the inter-model deviation is largest near surface over the Arctic. The internal variability of CF simulated in ensemble runs with the same model is very minimal.

Qian, Yun; Long, Charles N.; Wang, Hailong; Comstock, Jennifer M.; McFarlane, Sally A.; Xie, Shaocheng

2012-02-17T23:59:59.000Z

297

Novel fuzzy logic based sensorless maximum power point tracking strategy for wind turbine systems driven DFIG (doubly-fed induction generator)  

Science Journals Connector (OSTI)

Abstract This paper presents a novel FLC MPPT (fuzzy logic sensorless maximum power point tracking) method for WECS (wind energy conversion systems). The proposed method greatly reduces the speed variation range of the wind generator which leads to the downsizing the PWM (pulse width modulation) back-to-back converters by approximately 40% in comparison with conventional techniques. The method also increases the system's reliability by reducing the converter losses. Firstly, a MRAS (model reference adaptive system) based on fuzzy logic technique is used to estimate the DFIG (doubly-fed induction generator) rotor's speed. Then, a FLC MPPT (Fuzzy Logic Maximum Power Point Tracking) method is applied to provide the reference electromagnetic torque. Subsequently, in order to achieve the overall sensorless MPPT technique, the wind power is approximated from estimated generator speed and the reference of electromagnetic torque. Finally, the wind speed is estimated from the mechanical power using a fuzzy logic technique. The proposed control method has been applied to a WTG (wind turbine generator) driving a 3.7 kW DFIG in variable speed mode. In order to validate the simulation results, experimental tests have been performed on a 3.7 kW test bench, consisting of a DFIG and DC motor drive.

K. Belmokhtar; M.L. Doumbia; K. Agbossou

2014-01-01T23:59:59.000Z

298

An Ad-Hoc Method for Obtaining chi**2 Values from Unbinned Maximum Likelihood Fits  

E-Print Network [OSTI]

A common goal in an experimental physics analysis is to extract information from a reaction with multi-dimensional kinematics. The preferred method for such a task is typically the unbinned maximum likelihood method. In fits using this method, the likelihood is a goodness-of-fit quantity in that it effectively discriminates between available hypotheses; however, it does not provide any information as to how well the best hypothesis describes the data. In this paper, we present an {\\em ad-hoc} procedure for obtaining chi**2/n.d.f. values from unbinned maximum likelihood fits. This method does not require binning the data, making it very applicable to multi-dimensional problems.

M. Williams; C. A. Meyer

2008-06-30T23:59:59.000Z

299

A comparison of maximum likelihood and other estimators of eigenvalues from several correlated Monte Carlo samples  

SciTech Connect (OSTI)

The maximum likelihood method for the multivariate normal distribution is applied to the case of several individual eigenvalues. Correlated Monte Carlo estimates of the eigenvalue are assumed to follow this prescription and aspects of the assumption are examined. Monte Carlo cell calculations using the SAM-CE and VIM codes for the TRX-1 and TRX-2 benchmark reactors, and SAM-CE full core results are analyzed with this method. Variance reductions of a few percent to a factor of 2 are obtained from maximum likelihood estimation as compared with the simple average and the minimum variance individual eigenvalue. The numerical results verify that the use of sample variances and correlation coefficients in place of the corresponding population statistics still leads to nearly minimum variance estimation for a sufficient number of histories and aggregates.

Beer, M.

1980-12-01T23:59:59.000Z

300

Maximum-Entropy Meshfree Method for Compressible and Near-Incompressible Elasticity  

SciTech Connect (OSTI)

Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a locking-free small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximum-entropy meshfree formulation.

Ortiz, A; Puso, M A; Sukumar, N

2009-09-04T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

A maximum entropy theorem with applications to the measurement of biodiversity  

E-Print Network [OSTI]

This is a preliminary article stating and proving a new maximum entropy theorem. The entropies that we consider can be used as measures of biodiversity. In that context, the question is: for a given collection of species, which frequency distribution(s) maximize the diversity? The theorem provides the answer. The chief surprise is that although we are dealing not just with a single entropy, but a one-parameter family of entropies, there is a single distribution maximizing all of them simultaneously.

Leinster, Tom

2009-01-01T23:59:59.000Z

302

Computation of the maximum loadability of a power system using nonlinear optimization  

E-Print Network [OSTI]

Between Generator and Load. . . . . . . . . 34 E. Flowchart for Optimization Program F. Tutorial Example G. Conclusion. . 35 36 44 V SIMULATION RESULTS. 45 A. Introduction. B. Results of Simulation for Maximum Loadability of the Total System. I... of this work starting from the basics. Chapter III will cover concepts of power flow and loadability along with tutorial example. The literature survey over this topic and previous work as well as problem statement and solution method will be covered...

Khabirov, Abdufarrukh

2001-01-01T23:59:59.000Z

303

Hydrodynamic equations for electrons in graphene obtained from the maximum entropy principle  

SciTech Connect (OSTI)

The maximum entropy principle is applied to the formal derivation of isothermal, Euler-like equations for semiclassical fermions (electrons and holes) in graphene. After proving general mathematical properties of the equations so obtained, their asymptotic form corresponding to significant physical regimes is investigated. In particular, the diffusive regime, the Maxwell-Boltzmann regime (high temperature), the collimation regime and the degenerate gas limit (vanishing temperature) are considered.

Barletti, Luigi, E-mail: luigi.barletti@unifi.it [Dipartimento di Matematica e Informatica “Ulisse Dini”, Universitŕ degli Studi di Firenze, Viale Morgagni 67/A, 50134 Firenze (Italy)

2014-08-15T23:59:59.000Z

304

An Analysis of Maximum Residential Energy Efficiency in Hot and Humid Climates  

E-Print Network [OSTI]

the high efficiency instantaneous water heater with electronic ignition. The largest equipment energy savings (20%) was achieved from the horizontal-axis clothes washer. Compact fluorescent lamps (CFLs) saved 75% lighting energy use. Among all...AN ANALYSIS OF MAXIMUM RESIDENTIAL ENERGY EFFICIENCY IN HOT AND HUMID CLIMATES Mini Malhotra Graduate Research Assistant Jeff Haberl, Ph.D., P.E. Professor/Associate Director Energy Systems Laboratory, Texas A&M University College...

Malhotra, M.; Haberl, J. S.

2006-01-01T23:59:59.000Z

305

U.S. Maximum Number of Active Crews Engaged in Seismic Surveying (Number of  

Gasoline and Diesel Fuel Update (EIA)

Maximum Number of Active Crews Engaged in Seismic Surveying (Number of Elements) Maximum Number of Active Crews Engaged in Seismic Surveying (Number of Elements) U.S. Maximum Number of Active Crews Engaged in Seismic Surveying (Number of Elements) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2000 0 0 62 63 59 63 58 61 59 63 62 65 2001 61 61 63 65 64 60 58 56 54 58 59 58 2002 54 57 54 50 51 50 52 50 56 57 50 43 2003 40 41 41 40 38 39 41 43 39 39 38 42 2004 43 45 45 45 44 49 48 49 48 48 49 50 2005 52 53 51 50 55 57 54 55 56 57 57 58 2006 55 57 59 58 58 57 66 62 63 64 65 64 2007 63 63 68 71 70 69 69 71 73 77 79 75 2008 76 77 75 72 73 73 72 72 NA 77 72 73 2009 75 76 72 70 65 60 61 60 60 63 62 63 2010 64 65 63 66 67 67 67 65 64 62 62 62

306

Effect of altered boundary conditions on GCM studies of the climate of the last glacial maximum  

SciTech Connect (OSTI)

The authors address a problem discovered recently with global climate model results for the last glacial maximum. Bard, et. al. pointed out a mismatch in boundary conditions entered into the model. Ice sheet conditions were derived from CLIMAP based on a time 18000 radiocarbon years ago. It was assumed that radiocarbon and sidereal dates coincide. However it was recently shown that the sidereal data of the last glacial maximum is nearer 21kbp. The authors perform model calculations to attempt to evaluate the seriousness of this mismatch in terms of calculated results from the global climate model runs for the last glacial maximum. The authors find that one result of the timing mismatch is a sizable difference in northern hemisphere summer and Eurasian winter climates. These changes should have a major impact on circulation patterns in the GCM simulations. In addition new ice sheet model programs are available now which appear to improve on CLIMAP models. The authors urge that these GCM simulations be rerun.

Hyde, W.T.; Peltier, W.R.

1993-05-21T23:59:59.000Z

307

A proposed methodology for medium-range maximum demand anticipation and application  

Science Journals Connector (OSTI)

One to three years' anticipation of monthly and weekly peak demand is required to prepare maintenance schedules, develop power pooling agreements, select peaking capacity and provide data required by certain reliability coordinating centers. A total monthly forecast of the maximum demand is deduced and computed for the three years up to April 1981. This is accomplished for an important electrical network in Egypt. The anticipated maximum demand is executed for El-Mehalla El-Kubra city network. This network has an industrial and residential daily load characteristic. Direct monthly maximum demand forecasting is executed by separate treatment of weather-independent and weather-induced demand. The required forecast is derived by two methodologies: the probabilistic extrapolation-correlation, and that suggested by the authors. Daily and monthly data have been collected for more reliable determination of weather load models. Complete analysis, discussion and comments on the results are presented, and the results compared. This comparison reveals that an acceptable and reasonable percentage error is obtained on applying the proposed methodology.

M.S. Kandil; M.Helmy El-Maghraby; H. El-Dosouky

1981-01-01T23:59:59.000Z

308

Quantifying global marine isoprene fluxes using MODIS chlorophyll observations  

E-Print Network [OSTI]

, with considerable spatial and temporal variability, resulting in a global annual total of 0.1 Tg C/yr. Air vegetation [Guenther et al., 1995], with the tropics responsible for most of the global annual total ($500 TgQuantifying global marine isoprene fluxes using MODIS chlorophyll observations Paul I. Palmer

Palmer, Paul

309

Observationally based assessment of polar amplification of global warming  

E-Print Network [OSTI]

Observationally based assessment of polar amplification of global warming Igor V. Polyakov,1) are similar, and do not support the predicted polar amplification of global warming. The possible moderating amplification of global warming. Intrinsic arctic variability obscures long-term changes, limiting our ability

Bhatt, Uma

310

Observations and Theories of Langmuir Circulation: A Story of Mixing  

E-Print Network [OSTI]

occasion to review the history of this field of study. An underlying theme here is that the study interdisciplinary history; the first half of this work is a brief and eclectic review of this. Much of the research recent observations and the nature of this unexplained variability. 1 Introduction The oceanic surface

Smith, Jerome A.

311

The Role of Global Observations for Climate and Other Applications  

SciTech Connect (OSTI)

Most of the current earth-observing systems have been designed primarily for the needs of weather forecasting. Weather forecasting is an initial condition problem; the success of the forecast is heavily dependent on the quality of the specified initial state of the atmosphere. Thus, weather forecasting observing systems tend to focus on determining the 3D values of the state variables of the system namely temperature, humidity, and wind vector. While weather forecasting requires accurate observations, spatial patterns and relative accuracy across those patterns are the primary concern. Climate, on the other hand, is a boundary condition problem, i.e., climate simulation depends on knowing the energy fluxes into and out of the system, and quantities such as CO2 that affect the flow of those energy fluxes in the system. Consequently, climate-observing systems must extend beyond measurements of state variables to flux measurements of radiation energy and water. We focus on these two cycles because the dominant forms of energy transfer in the climate system (solar energy, thermal infrared energy, evaporation, and condensation) involve these two quantities. Further, because climate is a search for small system trends and imbalances in the midst of large weather variability, climate observations require a much higher degree of precision than do weather observations.

T.P. Ackerman

2005-05-01T23:59:59.000Z

312

The Role of Global Observations for Climate and Other Applications  

SciTech Connect (OSTI)

Most of the current earth-observing systems have been designed primarily for the needs of weather forecasting. Weather forecasting is an initial condition problem; the success of the forecast is heavily dependent on the quality of the specified initial state of the atmosphere. Thus, weather forecasting observing systems tend to focus on determining the 3D values of the state variables of the system – namely temperature, humidity, and wind vector. While weather forecasting requires accurate observations, spatial patterns and relative accuracy across those patterns are the primary concern. Climate, on the other hand, is a boundary condition problem, i.e., climate simulation depends on knowing the energy fluxes into and out of the system, and quantities such as CO2 that affect the flow of those energy fluxes in the system. Consequently, climate-observing systems must extend beyond measurements of state variables to flux measurements of radiation energy and water. We focus on these two cycles because the dominant forms of energy transfer in the climate system (solar energy, thermal infrared energy, evaporation, and condensation) involve these two quantities. Further, because climate is a search for small system trends and imbalances in the midst of large weather variability, climate observations require a much higher degree of precision than do weather observations.

Ackerman, TP

2005-05-01T23:59:59.000Z

313

A maximum power tracking algorithm based on photovoltaic current control for matching loads to a photovoltaic generator  

Science Journals Connector (OSTI)

In this paper, a novel maximum power point tracking (MPPT) approach is studied. It is based on the photovoltaic (PV) current control. The last one...

Ben Hamed Mouna; Sbita Lassaâd

2012-10-01T23:59:59.000Z

314

The Hard X-ray Sky: Recent Observational Progress  

SciTech Connect (OSTI)

The last fifty years have witnessed the birth, development, and maturation to full potential of hard X-ray astrophysics. The primary force driving the history of the field has been the development of space-based instrumentation optimized for getting the maximum science out of observations of high-energy photons from astrophysical sources. Hard X-ray telescopes are leading research in areas such as galactic diffuse emission, galactic transients, and active galactic nuclei.

Gehrels, Neil [NASA/GSFC/ASD/Code 661, Greenbelt, Md 20071 (United States); Cannizzo, John K. [CRESST/UMBC/NASA/GSFC/ASD/Code 661, Greenbelt, Md 20071 (United States)

2009-05-11T23:59:59.000Z

315

Observing a Quantum Phase Transition by Measuring a Single Spin  

E-Print Network [OSTI]

We show that the ground-state quantum correlations of an Ising model can be detected by monitoring the time evolution of a single spin alone, and that the critical point of a quantum phase transition is detected through a maximum of a suitably defined observable. A proposed implementation with trapped ions realizes an experimental probe of quantum phase transitions which is based on quantum correlations and scalable for large system sizes.

Manuel Gessner; Michael Ramm; Hartmut Haeffner; Andreas Buchleitner; Heinz-Peter Breuer

2014-03-17T23:59:59.000Z

316

Essays on Bayesian Time Series and Variable Selection  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 vi LIST OF FIGURES FIGURE Page 2.1 Dynamic Model. Given xt, yt is independent of y1:t?1, x1:t?1. . . . . . . 7 2.2 The figure shows estimated value of ? and ?2 from : (a)-(b) Stochastic Approximation approach; (c)-(d) Augmentation approach. In each... Sorenson (1970). 6 Let yt and xt be the p and q dimensional observation and hidden state variable at the time t. Let ? be set of unknown parameter. Figure (2.1) depicts the dynamic relation between yt and xt. The generalized version of state-space model can...

De, Debkumar

2014-05-08T23:59:59.000Z

317

Spatial Corrections of ROSAT HRI Observations  

E-Print Network [OSTI]

X-ray observations with the ROSAT High Resolution Imager (HRI) often have spatial smearing on the order of 10 arcsec (Morse 1994). This degradation of the intrinsic resolution of the instrument (5 arcsec) can be attributed to errors in the aspect solution associated with the wobble of the space craft or with the reacquisition of the guide stars. We have developed a set of IRAF/PROS and MIDAS/EXSAS routines to minimize these effects. Our procedure attempts to isolate aspect errors that are repeated through each cycle of the wobble. The method assigns a 'wobble phase' to each event based on the 402 second period of the ROSAT wobble. The observation is grouped into a number of phase bins and a centroid is calculated for each sub-image. The corrected HRI event list is reconstructed by adding the sub-images which have been shifted to a common source position. This method has shown approx. 30% reduction of the full width half maximum (FWHM) of an X-ray observation of the radio galaxy 3C 120. Additional examples are presented.

D. E. Harris; J. D. Silverman; G. Hasinger; I. Lehmann

1998-11-08T23:59:59.000Z

318

Liquid-Liquid Transition at Tg and Stable-Glass Phase Nucleation Rate Maximum at the Kauzmann Temperature TK  

E-Print Network [OSTI]

An undercooled liquid is unstable. The driving force of the glass transition at Tg is a change of the undercooled-liquid Gibbs free energy. The classical Gibbs free energy change for a crystal formation is completed including an enthalpy saving. The crystal growth critical nucleus is used as a probe to observe the Laplace pressure change Dp accompanying the enthalpy change -Vm*Dp at Tg where Vm is the molar volume. A stable glass-liquid transition model predicts the specific heat jump of fragile liquids at temperatures smaller than Tg, the Kauzmann temperature TK where the liquid entropy excess with regard to crystal goes to zero, the equilibrium enthalpy between TK and Tg, the maximum nucleation rate at TK of superclusters containing magic atom numbers, and the equilibrium latent heats at Tg and TK. Strong-to-fragile and strong-to-strong liquid transitions at Tg are also described and all their thermodynamic parameters are determined from their specific heat jumps. The existence of fragile liquids quenched in the amorphous state, which do not undergo liquid-liquid transition during heating preceding their crystallization, is predicted. Long ageing times leading to the formation at TK of a stable glass composed of superclusters containing up to 147 atoms, touching and interpenetrating, are evaluated from nucleation rates.

Robert Felix Tournier

2014-04-10T23:59:59.000Z

319

Maximum magnitude in bias-dependent spin accumulation signals of CoFe/MgO/Si on insulator devices  

SciTech Connect (OSTI)

We study in detail how the bias voltage (V{sub bias}) and interface resistance (RA) depend on the magnitude of spin accumulation signals (|?V| or |?V|/I, where I is current) as detected by three-terminal Hanle measurements in CoFe/MgO/Si on insulator (SOI) devices with various MgO layer thicknesses and SOI carrier densities. We find the apparent maximum magnitude of spin polarization as a function of V{sub bias} and the correlation between the magnitude of spin accumulation signals and the shape of differential conductance (dI/dV) curves within the framework of the standard spin diffusion model. All of the experimental results can be explained by taking into account the density of states (DOS) in CoFe under the influence of the applied V{sub bias} and the quality of MgO tunnel barrier. These results indicate that it is important to consider the DOS of the ferromagnetic materials under the influence of an applied V{sub bias} and the quality of tunnel barrier when observing large spin accumulation signals in Si.

Ishikawa, M., E-mail: mizue.ishikawa@toshiba.co.jp; Sugiyama, H.; Inokuchi, T.; Tanamoto, T.; Saito, Y. [Corporate Research and Development Center, Toshiba Corporation, 1 Komukai Toshiba-cho, Kawasaki, Kanagawa 212-8582 (Japan); Hamaya, K. [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Tezuka, N. [Department of Materials Science, Graduate School of Engineering, Tohoku University, 6-6-02 Aramaki-aza-Aoba, Sendai, Miyagi 980-8579 (Japan)

2013-12-28T23:59:59.000Z

320

LATE-TIME SPECTRAL OBSERVATIONS OF THE STRONGLY INTERACTING TYPE Ia SUPERNOVA PTF11kx  

SciTech Connect (OSTI)

PTF11kx was a Type Ia supernova (SN Ia) that showed time-variable absorption features, including saturated Ca II H and K lines that weakened and eventually went into emission. The strength of the emission component of H{alpha} gradually increased, implying that the SN was undergoing significant interaction with its circumstellar medium (CSM). These features, and many others, were blueshifted slightly and showed a P-Cygni profile, likely indicating that the CSM was directly related to, and probably previously ejected by, the progenitor system itself. These and other observations led Dilday et al. to conclude that PTF11kx came from a symbiotic nova progenitor like RS Oph. In this work we extend the spectral coverage of PTF11kx to 124-680 rest-frame days past maximum brightness. The late-time spectra of PTF11kx are dominated by H{alpha} emission (with widths of full width at half-maximum intensity Almost-Equal-To 2000 km s{sup -1}), strong Ca II emission features ({approx}10,000 km s{sup -1} wide), and a blue 'quasi-continuum' due to many overlapping narrow lines of Fe II. Emission from oxygen, He I, and Balmer lines higher than H{alpha} is weak or completely absent at all epochs, leading to large observed H{alpha}/H{beta} intensity ratios. The H{alpha} emission appears to increase in strength with time for {approx}1 yr, but it subsequently decreases significantly along with the Ca II emission. Our latest spectrum also indicates the possibility of newly formed dust in the system as evidenced by a slight decrease in the red wing of H{alpha}. During the same epochs, multiple narrow emission features from the CSM temporally vary in strength. The weakening of the H{alpha} and Ca II emission at late times is possible evidence that the SN ejecta have overtaken the majority of the CSM and agrees with models of other strongly interacting SNe Ia. The varying narrow emission features, on the other hand, may indicate that the CSM is clumpy or consists of multiple thin shells.

Silverman, Jeffrey M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Nugent, Peter E.; Filippenko, Alexei V.; Cenko, S. Bradley [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gal-Yam, Avishay [Benoziyo Center for Astrophysics, The Weizmann Institute of Science, Rehovot 76100 (Israel); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Howell, D. Andrew [Las Cumbres Observatory Global Telescope Network, Goleta, CA 93117 (United States); Pan, Yen-Chen; Hook, Isobel M., E-mail: jsilverman@astro.as.utexas.edu [Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)

2013-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Performance of twist-coupled blades on variable speed rotors  

SciTech Connect (OSTI)

The load mitigation and energy capture characteristics of twist-coupled HAWT blades that are mounted on a variable speed rotor are investigated in this paper. These blades are designed to twist toward feather as they bend with pretwist set to achieve a desirable twist distribution at rated power. For this investigation, the ADAMS-WT software has been modified to include blade models with bending-twist coupling. Using twist-coupled and uncoupled models, the ADAMS software is exercised for steady wind environments to generate C{sub p} curves at a number of operating speeds to compare the efficiencies of the two models. The ADAMS software is also used to generate the response of a twist-coupled variable speed rotor to a spectrum of stochastic wind time series. This spectrum contains time series with two mean wind speeds at two turbulence levels. Power control is achieved by imposing a reactive torque on the low speed shaft proportional to the RPM squared with the coefficient specified so that the rotor operates at peak efficiency in the linear aerodynamic range, and by limiting the maximum RPM to take advantage of the stall controlled nature of the rotor. Fatigue calculations are done for the generated load histories using a range of material exponents that represent materials from welded steel to aluminum to composites, and results are compared with the damage computed for the rotor without twist-coupling. Results indicate that significant reductions in damage are achieved across the spectrum of applied wind loading without any degradation in power production.

Lobitz, D.W.; Veers, P.S.; Laino, D.J.

1999-12-07T23:59:59.000Z

322

Observations of Edge Turbulence  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Edge Turbulence Edge Turbulence near the X-point of Alcator C-Mod APS-2007 (1) J.L. Terry, S.J. Zweben*, B. LaBombard, I. Cziegler, O. Grulke + , D.P. Stotler* MIT - Plasma Science and Fusion Center *Princeton Plasma Physics Laboratory + MPI for Plasma Physics, EURATOM Assoc., Greifswald, Germany American Physical Society - Div. of Plasma Physics Orlando, FL Nov. 12 - Nov. 16, 2007 APS-2007 (2) Background and Motivation for "Xpt-region" View Strong edge turbulence has been observed in nearly all magnetic confinement devices. Desire predictive capability Most previous measurements made near outboard midplane where the turbulence has the following main features: - generation is ballooning-like (absent at inboard midplane, etc.) - filaments/blobs moves radially outward with some poloidal motion

323

The Energy-Dependence of GRB Minimum Variability Timescales  

E-Print Network [OSTI]

We constrain the minimum variability timescales for 938 GRBs observed by the Fermi/GBM instrument prior to July 11, 2012. The tightest constraints on progenitor radii derived from these timescales are obtained from light curves in the hardest energy channel. In the softer bands -- or from measurements of the same GRBs in the hard X-rays from Swift -- we show that variability timescales tend to be a factor 2--3 longer. Applying a survival analysis to account for detections and upper limits, we find median minimum timescale in the rest frame for long-duration and short-duration GRBs of 45 ms and 10 ms, respectively. Fewer than 10% of GRBs show evidence for variability on timescales below 2 ms. These shortest timescales require Lorentz factors $\\gtrsim 400$ and imply typical emission radii $R \\approx 1 {\\times} 10^{14}$ cm for long-duration GRBs and $R \\approx 3 {\\times} 10^{13}$ cm for short-duration GRBs. We discuss implications for the GRB fireball model and investigate whether GRB minimum timescales evolve w...

Golkhou, V Zach; Littlejohns, Owen M

2015-01-01T23:59:59.000Z

324

Hybrid permanent magnet and variable reluctance generator  

SciTech Connect (OSTI)

This patent describes a hybrid electrical generator. It comprises: a permanent magnet generator having a permanent magnet rotor mounted on a shaft, the permanent magnet generator providing an output voltage over an operating range which falls in response to an increasing electrical load; a variable reluctance generator having a rotor mounted on the shaft with excitation of a stator of the variable reluctance generator being provided from the permanent magnet generator, the variable reluctance generator providing an output voltage which varies in response to an increasing electrical load over an operating range; and a voltage regulator, responsive to combined output voltages of the generators, for controlling the output voltage provided by the variable reluctance generator.

Vaidya, J.; Belanger, D.J.

1990-09-25T23:59:59.000Z

325

Variable Temperature Scanning Probe Microscope | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

EMSL's ultra-high vacuum, variable-temperature scanning probe microscope system, or UHV VT SPM, is a state-of-the-art surface science tool comprising multiple complementary...

326

Lensmem a gravitational lens inversion algorithm using the maximum entropy method  

E-Print Network [OSTI]

We present a new algorithm for inverting poorly resolved gravitational lens systems using the maximum entropy method (MEM). We test the method with simulations and then apply it to an 8 GHz VLA map of the radio ring lens MG1654+134. We model the lens as a singular isothermal sphere embedded in an external shear field and find the critical radius of the lens is b=0\\parcs9820, the dimensionless shear is \\gamma=0.0771, and the position angle of the shear is \\theta=100\\pdeg8. These results are consistent with the results obtained by Kochanek (1995) using a complementary inversion algorithm based on Clean.

Wallington, S; Narayan, R

1995-01-01T23:59:59.000Z

327

LensMEM: A Gravitational Lens Inversion Algorithm Using the Maximum Entropy Method  

E-Print Network [OSTI]

We present a new algorithm for inverting poorly resolved gravitational lens systems using the maximum entropy method (MEM). We test the method with simulations and then apply it to an 8 GHz VLA map of the radio ring lens MG1654+134. We model the lens as a singular isothermal sphere embedded in an external shear field and find the critical radius of the lens is $b=0\\parcs9820$, the dimensionless shear is $\\gamma=0.0771$, and the position angle of the shear is $\\theta=100\\pdeg8$. These results are consistent with the results obtained by Kochanek (1995) using a complementary inversion algorithm based on Clean.

S. Wallington; C. S. Kochanek; R. Narayan

1995-11-28T23:59:59.000Z

328

Buoyancy-generated variable-density turbulence  

SciTech Connect (OSTI)

Both a one-point (engineering) and a two-point (spectral) model are tested against numerical data. Deficiencies in these variable-density models are disucssed and modifications are suggested. Attention is restricted to turbulent interactions of two miscible, incompressible Newtonian fluids of different densities. Departures from the limits of validity of the Boussinesq approximation are examined. Results of the buoyancy-generated turbulence are compared with variable-density model predictions. 3 figs, 6 refs.

Sandoval, D.L. [Los Alamos National Lab., NM (United States)]|[Washington Univ. (United States); Clark, T.T. [Los Alamos National Lab., NM (United States); Riley, J.J. [Washington Univ. (United States)

1996-06-01T23:59:59.000Z

329

Prctica 2. Anlisi descriptiva univariable: variables qualitatives  

E-Print Network [OSTI]

nominal SEXO. Codificada de tipus "numèrica" amb valors 1 i 2. Aquests valors s'etiqueten amb: 1 `Hombre": (1) Seleccionem la variable sexo i la col·loquem al requadre de "Variables". D'aquesta manera obtenim: Frecuencias [Conjunto_de_datos1] C:\\Archivos de programa\\SPSS\\GSS93 reducido.sav Estadísticos sexo Sexo del

Castellana, NatĂ lia

330

Prctica 2. Anlisi descriptiva univariable: variables qualitatives  

E-Print Network [OSTI]

nominal SEXO. Codificada de tipus "numèrica" amb valors 1 i 2. Aquests valors s'etiqueten amb: 1 `Hombre) Seleccionem la variable sexo i la col·loquem al requadre de "Variables". D'aquesta manera obtenim la taula de Estadísticos Sexo del entrevistado 1500 0 2 Válidos Perdidos N Moda sexo Sexo del entrevistado 641 42,7 42,7 42

Castellana, NatĂ lia

331

A satellite ocean color observation operator system for eutrophication assessment in coastal waters  

E-Print Network [OSTI]

Group (IOCCG) and following their recent guidelines, novel in- herent optical properties approaches (e of model variables into observed quantities which simplifies the transport of measurement errors- chemical products (including

Fontana, Clément

332

New perspectives on observed and simulated late Antarctic sea ice extent trends using optimal fingerprinting techniques  

Science Journals Connector (OSTI)

Using optimal fingerprinting techniques, we performed a detection analysis to determine whether observed trends in Southern Ocean sea ice extent since 1979 are outside the expected range of natural variability. Consistent with previous studies, we ...

Will Hobbs; Nathaniel L. Bindoff; Marilyn N. Raphael

333

A branch, price, and cut approach to solving the maximum weighted independent set problem  

E-Print Network [OSTI]

(3.9) 1=#1; ? pJj jpl " },..,1{ Pp ? (3.10) 0‡jpl " },..,1{ Pp ? , pJj ? , (3.11) where pJ is the set of integer extreme points of pQ , jpx pVB? is the vector defining extreme point pJj ? , and jpl is the RMP decision variable... (3.9) 1=#1; ? pJj jpl " },..,1{ Pp ? (3.10) 0‡jpl " },..,1{ Pp ? , pJj ? , (3.11) where pJ is the set of integer extreme points of pQ , jpx pVB? is the vector defining extreme point pJj ? , and jpl is the RMP decision variable...

Warrier, Deepak

2007-09-17T23:59:59.000Z

334

Detection-estimation of very close emitters: performance breakdown, ambiguity, and general statistical analysis of maximum-likelihood estimation  

Science Journals Connector (OSTI)

We reexamine the well-known problem of "threshold behavior" or "performance breakdown" in the detection-estimation of very closely spaced emitters. In this extreme regime, we analyze the performance for maximum-likelihood estimation (MLE) of directions-of-arrival ... Keywords: direction-of-arrival (DOA) estimation, maximum-likelihood estimation, random matrix theory, signal detection, signal resolution

Yuri I. Abramovich; Ben A. Johnson

2010-07-01T23:59:59.000Z

335

ARM - Publications: Science Team Meeting Documents: Observations of Natural  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Observations of Natural Variability in Marine Stratocumulus Clouds Observations of Natural Variability in Marine Stratocumulus Clouds Albrecht, Bruce University of Miami Kollias, Pavlos RSMAS/University of Miami Jo, Ieng Rosentiel School of Marine & Atmospheric Science Ghate, Virendra RSMAS/Univ. Miami Serpetzoglou, Efthymious Minnis, Patrick NASA Langley Research Center Sun-Mack, Szedung SAIC Large to mesoscale features affecting the albedo of marine stratocumulus clouds are observed frequently and can have a substantial impact on the overall albedo of the subtropical cloud decks. One such naturally occurring feature-defined as a cloud rift-is characterized as a large-scale, persistent area of broken, low reflectivity stratocumulus clouds usually surrounded by a solid deck of stratocumulus. We review results from a

336

Simultaneous observations of Schumann resonances in California and Australia: Evidence for intensity modulation by the local height of the D region  

SciTech Connect (OSTI)

Observations are presented of the horizontal magnetic component of Schumann resonance intensities as simultaneously measured at locations in California and Western Australia during two separate intervals September 2-17, 1989, and April 14-21, 1990. For both intervals, diurnal variations of the average magnetic power over the lowest three modes of the Schumann resonances showed substantially different temporal profiles at the California and Western Australia stations, with interstation correlations of 0.51 and 0.39, respectively. A method is demonstrated for determining from these observations the average local time variation of the height of the D region. A height variation is obtained that is nearly identical for the respective analysis intervals, with a minimum height occurring at approximately 1300-1400 LT and a maximum-to-minimum height difference of roughly 50% of the mean. When corrected for the local D region height, the detailed diurnal intensity profiles over the analysis intervals display a greatly improved similarity, with interstation correlation coefficients increasing from 0.51 to 0.70 and from 0.39 to 0.82, respectively. Substantial agreement between the two stations after correction for D region height suggest that such observations could be used to monitor the global totality and variability of lightning, quantitatively and at time resolutions of the order of 10 min or less, in studies of global change.

Sentman, D.D. (Univ. of California, Los Angeles (United States)); Fraser, B.J. (Univ. of Newcastle, New South Wales (Australia))

1991-09-01T23:59:59.000Z

337

The periodic spectroscopic variability of FU Orionis  

Science Journals Connector (OSTI)

......the emergence of the energy liberated by accretion...of the central star in solar masses. The maximum...is the stellar mass in solar masses. Even in the...this could represent an economical solution to the two period...Associations and the Solar Vicinity. Kluwer, Dordrecht......

Stacie L. Powell; Mike Irwin; Jerome Bouvier; Cathie J. Clarke

2012-11-11T23:59:59.000Z

338

Essential ClimateVariables Chris Merchant  

E-Print Network [OSTI]

by radiative transfer modelling · High degree of independence · Good performance through volcanic aerosol 55 #12;Maximum impact objective for SST Ships Drifters Moorings Assess ocean temperature changes independently of current marine CDR. Text Wednesday, 2 September 2009 #12;ARC in ECV-speak Taking a single

339

Longwave thermal infrared spectral variability in individual rocks  

SciTech Connect (OSTI)

A hyperspectral imaging spectrometer measuring in the longwave thermal infrared (7.6-11.6 {micro}m) with a spatial resolution less than 4 mm was used in the field to observe the variability of emissivity spectra within individual rocks. The rocks were obtained commercially, were on the order of 20 cm in size and were selected to have distinct spectral features: they include alabaster (gypsum), soapstone (steatite with talc), obsidian (volcanic glass), norite (plagioclase and orthopyroxene), and 'jasper' (silica with iron oxides). The advantages of using an imaging spectrometer to spectrally characterize these rocks are apparent. Large spectral variations were observed within individual rocks that may be attributed to roughness, surface geometry, and compositional variation. Non-imaging spectrometers would normally miss these variations as would small samples used in laboratory measurements, spatially averaged spectra can miss the optimum spectra for identification materials and spatially localized components of the rock can be obscured.

Balick, Lee K [Los Alamos National Laboratory; Gillespie, Alan [UN. WASHINGTON; French, Andrew [USDA-ARS; Danilina, Iryna [UN. WASHINGTON

2008-01-01T23:59:59.000Z

340

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 +

Note: This page contains sample records for the topic "maximum variable observations" 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

Application of maximum likelihood methods to laser Thomson scattering measurements of low density plasmas  

SciTech Connect (OSTI)

Laser Thomson scattering (LTS) is an established plasma diagnostic technique that has seen recent application to low density plasmas. It is difficult to perform LTS measurements when the scattered signal is weak as a result of low electron number density, poor optical access to the plasma, or both. Photon counting methods are often implemented in order to perform measurements in these low signal conditions. However, photon counting measurements performed with photo-multiplier tubes are time consuming and multi-photon arrivals are incorrectly recorded. In order to overcome these shortcomings a new data analysis method based on maximum likelihood estimation was developed. The key feature of this new data processing method is the inclusion of non-arrival events in determining the scattered Thomson signal. Maximum likelihood estimation and its application to Thomson scattering at low signal levels is presented and application of the new processing method to LTS measurements performed in the plume of a 2-kW Hall-effect thruster is discussed.

Washeleski, Robert L.; Meyer, Edmond J. IV; King, Lyon B. [Michigan Technological University, Houghton, Michigan 49931 (United States)] [Michigan Technological University, Houghton, Michigan 49931 (United States)

2013-10-15T23:59:59.000Z

342

Maximum power point tracking of permanent magnet wind turbines equipped with direct matrix converter  

Science Journals Connector (OSTI)

This paper presents a novel control method for Maximum Power Point Tracking of wind turbines (WTs) equipped with a Permanent Magnet Synchronous Generator (PMSG) and a Direct Matrix Converter (DMC). The method calculates the optimum wind turbine speed and maximizes the extracted power from wind turbine. This is done by Hill Climb Search method which is simple and does not need to know the generator parameters and no need to solve the complicated differential equations of generator. WT rotor speed is compared with its optimal value and then DMC controls WT until its rotor speed reaches its optimum value. Under this situation maximum power is extracted from WT and is injected to the grid with unity power factor. It is implemented by controlling the phase and the amplitude of the DMC output voltage by Venturini switching method. Simulations are done on a 2?MW PMSG WT in MATLAB/SIMULINK to obtain the results the wind speed was varied both using the Van Der Hoven method and changing the wind step. The obtained results verify the accuracy and simplicity of proposed method.

2014-01-01T23:59:59.000Z

343

Dependency of U.S. Hurricane Economic Loss on Maximum Wind Speed and Storm Size  

E-Print Network [OSTI]

Many empirical hurricane economic loss models consider only wind speed and neglect storm size. These models may be inadequate in accurately predicting the losses of super-sized storms, such as Hurricane Sandy in 2012. In this study, we examined the dependencies of normalized U.S. hurricane loss on both wind speed and storm size for 73 tropical cyclones that made landfall in the U.S. from 1988 to 2012. A multi-variate least squares regression is used to construct a hurricane loss model using both wind speed and size as predictors. Using maximum wind speed and size together captures more variance of losses than using wind speed or size alone. It is found that normalized hurricane loss (L) approximately follows a power law relation with maximum wind speed (Vmax) and size (R). Assuming L=10^c Vmax^a R^b, c being a scaling factor, the coefficients, a and b, generally range between 4-12 and 2-4, respectively. Both a and b tend to increase with stronger wind speed. For large losses, a weighted regression model, with...

Zhai, Alice R

2014-01-01T23:59:59.000Z

344

Maximum wind energy contribution in autonomous electrical grids based on thermal power stations  

Science Journals Connector (OSTI)

Greek islands cover their continuously increasing electricity demand on the basis of small autonomous thermal power stations. This electrification solution is related with increased operational cost and power insufficiency, especially during summer. On the other hand, the stochastic behaviour of the wind and the important fluctuations of daily and seasonal electricity load in almost all Greek islands pose a substantial penetration limit for the exploitation of the high wind potential of the area. In this context, the present study is concentrated on developing an integrated methodology which can estimate the maximum wind energy contribution to the existing autonomous electrical grids, using the appropriate stochastic analysis. For this purpose one takes into account the electrical demand probability density profile of every island under investigation as well as the operational characteristics of the corresponding thermal power stations. Special attention is paid in order to protect the existing internal combustion engines from unsafe operation below their technical minima as well as to preserve the local system active power reserve and the corresponding dynamic stability. In order to increase the reliability of the results obtained, one may use extensive information for several years. Finally, the proposed study is integrated with an appropriate parametrical analysis, investigating the impact of the main parameters variation on the expected maximum wind energy contribution.

J.K. Kaldellis

2007-01-01T23:59:59.000Z

345

Thoracic target volume delineation using various maximum-intensity projection computed tomography image sets for radiotherapy treatment planning  

SciTech Connect (OSTI)

Purpose: Four-dimensional computed tomography (4D-CT) is commonly used to account for respiratory motion of target volumes in radiotherapy to the thorax. From the 4D-CT acquisition, a maximum-intensity projection (MIP) image set can be created and used to help define the tumor motion envelope or the internal gross tumor volume (iGTV). The purpose of this study was to quantify the differences in automatically contoured target volumes for usage in the delivery of stereotactic body radiation therapy using MIP data sets generated from one of the four methods: (1) 4D-CT phase-binned (PB) based on retrospective phase calculations, (2) 4D-CT phase-corrected phase-binned (PC-PB) based on motion extrema, (3) 4D-CT amplitude-binned (AB), and (4) cine CT built from all available images. Methods: MIP image data sets using each of the four methods were generated for a cohort of 28 patients who had prior thoracic 4D-CT scans that exhibited lung tumor motion of at least 1 cm. Each MIP image set was automatically contoured on commercial radiation treatment planning system. Margins were added to the iGTV to observe differences in the final simulated planning target volumes (PTVs). Results: For all patients, the iGTV measured on the MIP generated from the entire cine CT data set (iGTV{sub cine}) was the largest. Expressed as a percentage of iGTV{sub cine}, 4D-CT iGTV (all sorting methods) ranged from 83.8% to 99.1%, representing differences in the absolute volume ranging from 0.02 to 4.20 cm{sup 3}; the largest average and range of 4D-CT iGTV measurements was from the PC-PB data set. Expressed as a percentage of PTV{sub cine} (expansions applied to iGTV{sub cine}), the 4D-CT PTV ranged from 87.6% to 99.6%, representing differences in the absolute volume ranging from 0.08 to 7.42 cm{sup 3}. Regions of the measured respiratory waveform corresponding to a rapid change of phase or amplitude showed an increased susceptibility to the selection of identical images for adjacent bins. Duplicate image selection was most common in the AB implementation, followed by the PC-PB method. The authors also found that the image associated with the minimum amplitude measurement did not always correlate with the image that showed maximum tumor motion extent. Conclusions: The authors identified cases in which the MIP generated from a 4D-CT sorting process under-represented the iGTV by more than 10% or up to 4.2 cm{sup 3} when compared to the iGTV{sub cine}. They suggest utilization of a MIP generated from the full cine CT data set to ensure maximum inclusive tumor extent.

Zamora, David A.; Riegel, Adam C.; Sun Xiaojun; Balter, Peter; Starkschall, George; Mawlawi, Osama; Pan Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2010-11-15T23:59:59.000Z

346

THE RR LYRAE VARIABLES AND HORIZONTAL BRANCH OF NGC 6656 (M22) {sup ,}  

SciTech Connect (OSTI)

The first calibrated broadband UBVI time-series photometry is presented for the RR Lyrae variable stars in NGC 6656 (M22), with observations spanning a range of 22 years. We have also redetermined the variability types and periods for the RR Lyrae stars identified previously by photographic observations, revising the number of fundamental-mode RR Lyrae variables (RR0) to 10 and the number of first-overtone variables (RR1) to 16. The mean periods of the RR0 and RR1 variables are (P) {sub RR0} = 0.66 ± 0.02 days and (P) {sub RR1} = 0.33 ± 0.01 days, respectively, supporting an Oosterhoff II classification for the cluster. The number ratio of RR1-type to all RR-type variables is N {sub 1}/N{sub RR} = 0.61, also consistent with an Oosterhoff II designation. Both the RR Lyrae stars' minimum light colors and the blue edge of the RR Lyrae instability strip suggest E( B – – V) = 0.36 ± 0.02 mag toward M22. Regarding the HB morphology of M22, we find (B-R)/(B+V+R) = +0.97 ± 0.1 and at least one ''gap'' located in an unusual part of the blue HB, in the middle of the so-called hot HB stars.

Kunder, Andrea; Walker, Alistair R.; Paredes Alvarez, Leonardo [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Stetson, Peter B. [Dominion Astrophysical Observatory, NRC-Herzberg, National Research Council, Victoria BC, V9E 2E7 (Canada); Cassisi, Santi [INAF-Osservatorio Astronomico di Collurania, Via M. Maggini, I-64100 Teramo (Italy); Layden, Andrew [Bowling Green State University, Bowling Green, OH 43403 (United States); Bono, Giuseppe [Dipartimento di Fisica, Universita di Roma Tor Vergata, Rome (Italy); Catelan, Márcio [Pontificia Universidad Católica de Chile, Departamento de Astronomía y Astrofísica, Av. Vicuńa Mackenna 4860, 782-0436 Macul, Santiago (Chile); Clem, James L. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States); Matsunaga, Noriyuki [Department of Astronomy, School of Science, The University of Tokyo (Japan); Salaris, Maurizio [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Lee, Jae-Woo [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Chaboyer, Brian, E-mail: akunder@ctio.noao.edu, E-mail: mcatelan@astro.puc.cl [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

2013-11-01T23:59:59.000Z

347

The dynamics of variable-density turbulence  

SciTech Connect (OSTI)

The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field, is in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 128{sup 3} grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations. In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For the case of buoyancy-generated turbulence, variable-density departures from the Boussinesq approximation are studied. The results of the buoyancy-generated turbulence are compared with variable-density model predictions. Both a one-point (engineering) model and a two-point (spectral) model are tested against the numerical data. Some deficiencies in these variable-density models are discussed and modifications are suggested.

Sandoval, D.L.

1995-11-01T23:59:59.000Z

348

Cloud speed impact on solar variability scaling â?? Application to the wavelet variability model  

E-Print Network [OSTI]

Kleissl, J. , 2013. Deriving cloud velocity from an array ofCloud Speed Impact on Solar Variability Scaling -this work, we determine from cloud speeds. Cloud simulator

Lave, Matthew; Kleissl, Jan

2013-01-01T23:59:59.000Z

349

On the practice of dichotomization of quantitative variables  

E-Print Network [OSTI]

The authors examine the practice of dichotomization of quantitative measures, wherein relationships among variables are examined after 1 or more variables have been converted to dichotomous variables by splitting the sample ...

MacCallum, R. C.; Zhang, S.; Preacher, K. J.; Rucker, D. D.

2002-01-01T23:59:59.000Z

350

Software Enabled Virtually Variable Displacement Pumps -Theoretical and Experimental Studies  

E-Print Network [OSTI]

Software Enabled Virtually Variable Displacement Pumps - Theoretical and Experimental Studies the functional equivalent of a variable displacement pump. This approach combines a fixed displacement pump valve control, without many of the shortcomings of commercially available variable displacement pumps

Li, Perry Y.

351

The use of 'race' as a variable in biomedical research  

E-Print Network [OSTI]

be used as a variable in biomedical research but mainly toRace’ as a Variable in Biomedical Research A dissertationRace’ as a Variable in Biomedical Research…………. Manifest,

Efstathiou, Sophia

2009-01-01T23:59:59.000Z

352

The Deep Lens Survey Transient Search. I. Short Timescale and Astrometric Variability  

Science Journals Connector (OSTI)

We report on the methodology and first results from the Deep Lens Survey (DLS) transient search. We utilize image subtraction on survey data to yield all sources of optical variability down to 24th magnitude. Images are analyzed immediately after acquisition, at the telescope, and in near-real time, to allow for follow-up in the case of time-critical events. All classes of transients are posted to the World Wide Web upon detection. Our observing strategy allows sensitivity to variability over several decades in timescale. The DLS is the first survey to classify and report all types of photometric and astrometric variability detected, including solar system objects, variable stars, supernovae, and short timescale phenomena. Three unusual optical transient (OT) events were detected, flaring on 1000 s timescales. All three events were seen in the B passband, suggesting blue color indices for the phenomena. One event (OT 20020115) is determined to be from a flaring Galactic dwarf star of spectral type dM4. From the remaining two events, we find an overall rate of ? = 1.4 events deg-2 day-1 on 1000 s timescales, with a 95% confidence limit of ? R passband yields an upper 95% confidence limit on short-timescale astronomical variability in the range 19.5 R R -2 day-1. We report also on our ensemble of astrometrically variable objects, as well as an example of photometric variability with an undetected precursor.

A. C. Becker; D. M. Wittman; P. C. Boeshaar; A. Clocchiatti; I. P. Dell'Antonio; D. A. Frail; J. Halpern; V. E. Margoniner; D. Norman; J. A. Tyson; R. A. Schommer

2004-01-01T23:59:59.000Z

353

Confining sets and avoiding bottleneck cases: A simple maximum independent set algorithm in degree-3 graphs  

Science Journals Connector (OSTI)

We present an O ? ( 1.083 6 n ) -time algorithm for finding a maximum independent set in an n -vertex graph with degree bounded by 3, which improves all previous running time bounds for this problem. Our approach has the following two features. Without increasing the number of reduction/branching rules to get an improved time bound, we first successfully extract the essence from the previously known reduction rules such as domination, which can be used to get simple algorithms. More formally, we introduce a procedure for computing “confining sets”, which unifies several known reducible subgraphs and covers new reducible subgraphs. Second we identify those instances that generate the worst recurrence among all recurrences of our branching rules as “bottleneck instances” and prove that bottleneck instances cannot appear consecutively after each branching operation.

Mingyu Xiao; Hiroshi Nagamochi

2013-01-01T23:59:59.000Z

354

Coulomb explosion effect and the maximum energy of protons accelerated by high-power lasers  

Science Journals Connector (OSTI)

The acceleration of light ions (protons) through the interaction of a high-power laser pulse with a double-layer target is theoretically studied by means of two-dimensional particle-in-cell simulations and a one-dimensional analytical model. It is shown that the maximum energy acquired by the accelerated light ions (protons) depends on the physical characteristics of a heavy-ion layer (electron-ion mass ratio and effective charge state of the ions). In our theoretical model, the hydrodynamic equations for both electron and heavy-ion species are solved and the test-particle approximation for the light ions (protons) is applied. The heavy-ion motion is found to modify the longitudinal electric field distribution, thus changing the acceleration conditions for the protons.

E. Fourkal; I. Velchev; C.-M. Ma

2005-03-25T23:59:59.000Z

355

Maximum likelihood method to correct for missed levels based on the ?3(L) statistic  

Science Journals Connector (OSTI)

The ?3(L) statistic of random matrix theory is defined as the average of a set of random numbers {?}, derived from a spectrum. The distribution p(?) of these random numbers is used as the basis of a maximum likelihood method to gauge the fraction x of levels missed in an experimental spectrum. The method is tested on an ensemble of depleted spectra from the Gaussian orthogonal ensemble (GOE) and accurately returned the correct fraction of missed levels. Neutron resonance data and acoustic spectra of an aluminum block were analyzed. All results were compared with an analysis based on an established expression for ?3(L) for a depleted GOE spectrum. The effects of intruder levels are examined and seen to be very similar to those of missed levels. Shell model spectra were seen to give the same p(?) as the GOE.

Declan Mulhall

2011-05-26T23:59:59.000Z

356

Netest: A Tool to Measure the Maximum Burst Size, Available Bandwidth and Achievable Throughput  

SciTech Connect (OSTI)

Distinguishing available bandwidth and achievable throughput is essential for improving network applications' performance. Achievable throughput is the throughput considering a number of factors such as network protocol, host speed, network path, and TCP buffer space, where as available bandwidth only considers the network path. Without understanding this difference, trying to improve network applications' performance is like ''blind men feeling the elephant'' [4]. In this paper, we define and distinguish bandwidth and throughput, and debate which part of each is achievable and which is available. Also, we introduce and discuss a new concept - Maximum Burst Size that is crucial to the network performance and bandwidth sharing. A tool, netest, is introduced to help users to determine the available bandwidth, and provides information to achieve better throughput with fairness of sharing the available bandwidth, thus reducing misuse of the network.

Jin, Guojun; Tierney, Brian

2003-01-31T23:59:59.000Z

357

Maximum Achievable Control Technology for New Industrial Boilers (released in AEO2005)  

Reports and Publications (EIA)

As part of Clean Air Act 90 (CAAA90, the EPA on February 26, 2004, issued a final rulethe National Emission Standards for Hazardous Air Pollutants (NESHAP) to reduce emissions of hazardous air pollutants (HAPs) from industrial, commercial, and institutional boilers and process heaters. The rule requires industrial boilers and process heaters to meet limits on HAP emissions to comply with a Maximum Achievable Control Technology (MACT) floor level of control that is the minimum level such sources must meet to comply with the rule. The major HAPs to be reduced are hydrochloric acid, hydrofluoric acid, arsenic, beryllium, cadmium, and nickel. The EPA predicts that the boiler MACT rule will reduce those HAP emissions from existing sources by about 59,000 tons per year in 2005.

2005-01-01T23:59:59.000Z

358

Preventing Quantum Hacking in Continuous Variable Quantum Key Distribution  

Science Journals Connector (OSTI)

Security loopholes have been shown for discrete-variable Quantum Key Distribution (QKD). Here, we propose and provide experimental evidence of an attack targeting a continuous-variable...

Jouguet, Paul; Diamanti, Eleni; Kunz-Jacques, Sébastien

359

Impact of Real Field Diesel Quality Variability on Engine Emissions...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Real Field Diesel Quality Variability on Engine Emissions and Fuel Consumption Solutions for Onboard Optimisation Impact of Real Field Diesel Quality Variability on Engine...

360

Adaptation to Climate Variability and Change: A Guidance Manual...  

Open Energy Info (EERE)

to Climate Variability and Change: A Guidance Manual for Development Planning Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Adaptation to Climate Variability and...

Note: This page contains sample records for the topic "maximum variable observations" 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

Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical CO2. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical...

362

Pitch-variable blazed grating consisting of freestanding silicon beams  

Science Journals Connector (OSTI)

Theoretical analysis is presented for a pitch-variable blazed grating which consists of freestanding silicon beams. The pitch-variable blazed grating is implemented by combining...

Wang, Yongjin; Kanamori, Yoshiaki; Hane, Kazuhiro

2009-01-01T23:59:59.000Z

363

Advanced Variable Speed Air-Source Integrated Heat Pump 2013...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Advanced Variable Speed Air-Source Integrated Heat Pump 2013 Peer Review Emerging Technologies Project for...

364

Nonmonotone line search methods with variable sample size  

E-Print Network [OSTI]

The nonmonotone line search framework is embedded with a variable sample size ... the line search combines well with the variable sample size scheme as.

2014-02-17T23:59:59.000Z

365

Solutions for Interharmonics in Variable Speed Drives for LNG Plants:.  

E-Print Network [OSTI]

??Variable speed drives can cause components of any frequency known as interharmonics. Large variable speed drives in the order of tens of megawatts can replace… (more)

Verhulst, M.P.A.

2011-01-01T23:59:59.000Z

366

INSTALLATION, COMMISSIONING AND TROUBLE SHOOTING OF VARIABLE FREQUENCY DRIVE.  

E-Print Network [OSTI]

??In this thesis, the installation of variable frequency drive on board a ship is introduced briefly. In this particular study the variable frequency drive was… (more)

Kuituniemi, Santtu

2013-01-01T23:59:59.000Z

367

Control Strategies for Centrifugal Pumps with Variable Flow Rate...  

Broader source: Energy.gov (indexed) [DOE]

Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements This tip sheet discusses...

368

Variable Renewable Energy: a Regulatory Roadmap (Fact Sheet)...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Variable Renewable Energy: a Regulatory Roadmap Research Highlights There is not a one-size-fits-all approach to the regulation of variable renewable energy (VRE), but...

369

X-ray Observations of Mrk 231  

E-Print Network [OSTI]

This paper presents new X-ray observations of Mrk 231, an active galaxy of particular interest due to its large infrared luminosity and the presence of several blueshifted broad absorption line (BAL) systems, a phenomenon observed in a small fraction of QSOs. A ROSAT HRI image of Mrk 231 is presented, this shows an extended region of soft X-ray emission, covering several tens of kpc, consistent with the extent of the host galaxy. An ASCA observation of Mrk 231 is also presented. Hard X-rays are detected but the data show no significant variability in X-ray flux. The hard X-ray continuum is heavily attenuated and X-ray column estimates range from ~ 2 x 10^{22} - 10^{23} cm^{-2} depending on whether the material is assumed to be neutral or ionized, and on the model assumed for the extended X-ray component. These ASCA data provide only the second hard X-ray spectrum of a BAL AGN presented to date. The broad-band spectral-energy-distribution of the source is discussed. While Mrk 231 is X-ray weak compared to Seyfert 1 galaxies, it has an optical-to-X-ray spectrum typical of a QSO.

T. J. Turner

1998-08-10T23:59:59.000Z

370

Is the friction angle the maximum slope of a free surface of a non cohesive material?  

E-Print Network [OSTI]

Starting from a symmetric triangular pile with a horizontal basis and rotating the basis in the vertical plane, we have determined the evolution of the stress distribution as a function of the basis inclination using Finite Elements method with an elastic-perfectly plastic constitutive model, defined by its friction angle, without cohesion. It is found that when the yield function is the Drucker-Prager one, stress distribution satisfying equilibrium can be found even when one of the free-surface slopes is larger than the friction angle. This means that piles with a slope larger than the friction angle can be (at least) marginally stable and that slope rotation is not always a destabilising perturbation direction. On the contrary, it is found that the slope cannot overpass the friction angle when a Mohr-Coulomb yield function is used. Theoretical explanation of these facts is given which enlightens the role plaid by the intermediate principal stress in both cases of the Mohr-Coulomb criterion and of the Drucker-Prager one. It is then argued that the Mohr-Coulomb criterion assumes a spontaneous symmetry breaking, as soon as the two smallest principal stresses are different ; this is not physical most likely; so this criterion shall be replaced by a Drucker-Prager criterion in the vicinity of the equality, which leads to the previous anomalous behaviour ; so these numerical computations enlighten the avalanche process: they show that no dynamical angle larger than the static one is needed to understand avalanching. It is in agreement with previous experimental results. Furthermore, these results show that the maximum angle of repose can be modified using cyclic rotations; we propose a procedure that allows to achieve a maximum angle of repose to be equal to the friction angle .

A. Modaressi; P. Evesque

2005-07-13T23:59:59.000Z

371

Estimating climatological variability of solar energy production  

Science Journals Connector (OSTI)

Abstract A method is presented for estimating the climatological variability of yearly and monthly photovoltaic power production per 1 kWp of installed power. This quantity is computed for a specified portfolio of sources on the basis of historical data. Its climatological variability is derived from a simulation of 33 years of power production with hourly time step. Underlying meteorological variables are taken from the MERRA reanalysis for the years 1979–2011. Since the MERRA reanalysis is not a traditional data source for photovoltaic power modelling, various comparisons to available and more frequently used data sources are included. The method of estimation has the advantage of wide applicability due to the global coverage of the meteorological data.

Pavel Juruš; Kryštof Eben; Jaroslav Resler; Pavel Kr?; Ivan Kasanický; Emil Pelikán; Marek Brabec; Ji?í Hošek

2013-01-01T23:59:59.000Z

372

Measuring spatial variability in soil characteristics  

DOE Patents [OSTI]

The present invention provides systems and methods for measuring a load force associated with pulling a farm implement through soil that is used to generate a spatially variable map that represents the spatial variability of the physical characteristics of the soil. An instrumented hitch pin configured to measure a load force is provided that measures the load force generated by a farm implement when the farm implement is connected with a tractor and pulled through or across soil. Each time a load force is measured, a global positioning system identifies the location of the measurement. This data is stored and analyzed to generate a spatially variable map of the soil. This map is representative of the physical characteristics of the soil, which are inferred from the magnitude of the load force.

Hoskinson, Reed L. (Rigby, ID); Svoboda, John M. (Idaho Falls, ID); Sawyer, J. Wayne (Hampton, VA); Hess, John R. (Ashton, ID); Hess, J. Richard (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

373

Tests with a line-commutated converter as a variable inductive load on the Bonneville Power Administration transmission system  

SciTech Connect (OSTI)

A twelve-pulse, line-commutated converter, with a steady-state rating of 2.5 kV and 5.5 kA, formerly used for charging and discharging a superconducting magnet, was reconfigured as a static reactive power load. Tests staged at the Tacoma, WA, substation of the Bonneville Power Administration (BPA) revealed that the converter could be used as a variable inductive load, provided a stable current controller was installed. The unit was modulated as a variable VAR load following a sinusoidal VAR demand signal with an amplitude up to 14.8 MVAR. The total losses at maximum VAR output were 370 kW. This paper explains the necessary modifications of the converter to operate as a variable reactive load. Measured current waveshapes are analyzed. The effects of such a load on the BPA transmission system are presented.

Boenig, H.J.; Hauer, J.F.; Nielsen, R.G.

1986-01-01T23:59:59.000Z

374

Infrared Properties of Cataclysmic Variables from 2MASS Results from the 2nd Incremental Data Release  

E-Print Network [OSTI]

Because accretion-generated luminosity dominates the radiated energy of most cataclysmic variables, they have been ``traditionally'' observed primarily at short wavelengths. Infrared observations of cataclysmic variables contribute to the understanding of key system components that are expected to radiate at these wavelengths, such as the cool outer disk, accretion stream, and secondary star. We have compiled the J, H, and Ks photometry of all cataclysmic variables located in the sky coverage of the 2 Micron All Sky Survey (2MASS) 2nd Incremental Data Release. This data comprises 251 systems with reliably identified near-IR counterparts and S/N > 10 photometry in one or more of the three near-IR bands.

Hoard, D W; Clark, L L; Bowers, T P; Bowers, Timothy P.

2001-01-01T23:59:59.000Z

375

Integrating Variable Renewable Energy: Challenges and Solutions  

SciTech Connect (OSTI)

In the U.S., a number of utilities are adopting higher penetrations of renewables, driven in part by state policies. While power systems have been designed to handle the variable nature of loads, the additional supply-side variability and uncertainty can pose new challenges for utilities and system operators. However, a variety of operational and technical solutions exist to help integrate higher penetrations of wind and solar generation. This paper explores renewable energy integration challenges and mitigation strategies that have been implemented in the U.S. and internationally, including forecasting, demand response, flexible generation, larger balancing areas or balancing area cooperation, and operational practices such as fast scheduling and dispatch.

Bird, L.; Milligan, M.; Lew, D.

2013-09-01T23:59:59.000Z

376

Variable pressure power cycle and control system  

DOE Patents [OSTI]

A variable pressure power cycle and control system that is adjustable to a variable heat source is disclosed. The power cycle adjusts itself to the heat source so that a minimal temperature difference is maintained between the heat source fluid and the power cycle working fluid, thereby substantially matching the thermodynamic envelope of the power cycle to the thermodynamic envelope of the heat source. Adjustments are made by sensing the inlet temperature of the heat source fluid and then setting a superheated vapor temperature and pressure to achieve a minimum temperature difference between the heat source fluid and the working fluid.

Goldsberry, Fred L. (Spring, TX)

1984-11-27T23:59:59.000Z

377

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents [OSTI]

A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

1995-08-08T23:59:59.000Z

378

Using Feedforward Neural Networks and Forward Selection of Input Variables for an Ergonomics Data  

E-Print Network [OSTI]

Using Feedforward Neural Networks and Forward Selection of Input Variables for an Ergonomics Data-gradient algorithm to develop an FNN. This article presents an incremental step in the use of FNNs for ergonomics enhancing the effectiveness of the use of neural networks when observations are missing from ergonomics

Kaber, David B.

379

Properties of tropical convection observed by ARM millimeter-radars  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Properties of tropical convection observed by ARM millimeter-radars Properties of tropical convection observed by ARM millimeter-radars Haynes, John Colorado State University Stephens, Graeme Colorado State University Category: Cloud Properties The results of an analysis of tropical cloud systems observed from a variety of vertically pointing radar systems are described. In particular, observations taken during five years of operation of the ARM millimeter wavelength radar system (MMCR) at Manus Island in the Tropical West Pacific region are characterized into cloud classes according to the radar reflectivity structures of these cloud systems, associated rainfall, and surface radiative properties. These observations of cloud properties are composited with respect to various phases of the Madden Julian Oscillation, which is a dominant mode of variability at Manus Island. A method of better

380

Assessing net ecosystem carbon exchange of U S terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations  

SciTech Connect (OSTI)

More accurate projections of future carbon dioxide concentrations in the atmosphere and associated climate change depend on improved scientific understanding of the terrestrial carbon cycle. Despite the consensus that U.S. terrestrial ecosystems provide a carbon sink, the size, distribution, and interannual variability of this sink remain uncertain. Here we report a terrestrial carbon sink in the conterminous U.S. at 0.63 pg C yr 1 with the majority of the sink in regions dominated by evergreen and deciduous forests and savannas. This estimate is based on our continuous estimates of net ecosystem carbon exchange (NEE) with high spatial (1 km) and temporal (8-day) resolutions derived from NEE measurements from eddy covariance flux towers and wall-to-wall satellite observations from Moderate Resolution Imaging Spectroradiometer (MODIS). We find that the U.S. terrestrial ecosystems could offset a maximum of 40% of the fossil-fuel carbon emissions. Our results show that the U.S. terrestrial carbon sink varied between 0.51 and 0.70 pg C yr 1 over the period 2001 2006. The dominant sources of interannual variation of the carbon sink included extreme climate events and disturbances. Droughts in 2002 and 2006 reduced the U.S. carbon sink by 20% relative to a normal year. Disturbances including wildfires and hurricanes reduced carbon uptake or resulted in carbon release at regional scales. Our results provide an alternative, independent, and novel constraint to the U.S. terrestrial carbon sink.

Zhuang, Qianlai [Purdue University; Law, Beverly E. [Oregon State University; Baldocchi, Dennis [University of California, Berkeley; Ma, Siyan [University of California, Berkeley; Chen, Jiquan [University of Toledo, Toledo, OH; Richardson, Andrew [Harvard University; Melillo, Jerry [Marine Biological Laboratory; Davis, Ken J. [Pennsylvania State University; Hollinger, D. [USDA Forest Service; Wharton, Sonia [University of California, Davis; Falk, Matthias [University of California, Davis; Paw, U. Kyaw Tha [University of California, Davis; Oren, Ram [Duke University; Katulk, Gabriel G. [Duke University; Noormets, Asko [North Carolina State University; Fischer, Marc [Lawrence Berkeley National Laboratory (LBNL); Verma, Shashi [University of Nebraska; Suyker, A. E. [University of Nebraska, Lincoln; Cook, David R. [Argonne National Laboratory (ANL); Sun, G. [USDA Forest Service; McNulty, Steven G. [USDA Forest Service; Wofsy, Steve [Harvard University; Bolstad, Paul V [University of Minnesota; Burns, Sean [University of Colorado, Boulder; Monson, Russell K. [University of Colorado, Boulder; Curtis, Peter [Ohio State University, The, Columbus; Drake, Bert G. [Smithsonian Environmental Research Center, Edgewater, MD; Foster, David R. [Harvard University; Gu, Lianhong [ORNL; Hadley, Julian L. [Harvard University; Litvak, Marcy [University of New Mexico, Albuquerque; Martin, Timothy A. [University of Florida, Gainesville; Matamala, Roser [Argonne National Laboratory (ANL); Meyers, Tilden [NOAA, Oak Ridge, TN; Oechel, Walter C. [San Diego State University; Schmid, H. P. [Indiana University; Scott, Russell L. [USDA ARS; Torn, Margaret S. [Lawrence Berkeley National Laboratory (LBNL)

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

LONG-TERM OPTICAL POLARIZATION VARIABILITY OF THE TeV BLAZAR 1ES 1959+650  

SciTech Connect (OSTI)

A detailed analysis of the optical polarimetric variability of the TeV blazar 1ES 1959+650 from 2007 October 18 to 2011 May 5 is presented. The source showed maximum and minimum brightness states in the R band of 14.08 {+-} 0.03 mag and 15.20 {+-} 0.03 mag, respectively, with a maximum variation of 1.12 mag, and a maximum polarization degree of P = (12.2 {+-} 0.7)%, with a maximum variation of 10.7%. From 2009 August to November, a correlation between the optical R-band flux and the degree of linear polarization was found with a correlation coefficient r {sub pol} = 0.984 {+-} 0.025. The source presented a preferential position angle of optical polarization of {approx}153 Degree-Sign , with variations of 10 Degree-Sign -50 Degree-Sign , which is in agreement with the projected position angle of the parsec-scale jet found at 43 GHz. From the Stokes parameters we infer the existence of two optically thin synchrotron components that contribute to the polarized flux. One of them is stable with a constant polarization degree of 4%. Assuming a stationary shock for the variable component, we estimated some parameters associated with the physics of the relativistic jet: the magnetic field, B {approx} 0.06 G, the Doppler factor, {delta}{sub 0} {approx} 23, the viewing angle, {Phi} {approx} 2. Degree-Sign 4, and the size of the emission region r{sub b} {approx} 5.6 Multiplication-Sign 10{sup 17} cm. Our study is consistent with the spine-sheath model of explaining the polarimetric variability displayed by this source during our monitoring.

Sorcia, Marco; Benitez, Erika; Cabrera, Jose I. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apdo. 70-264, Mexico D.F. 04510 (Mexico)] [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apdo. 70-264, Mexico D.F. 04510 (Mexico); Hiriart, David; Lopez, Jose M. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apdo. 810, Ensenada, B.C. 22800 (Mexico)] [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apdo. 810, Ensenada, B.C. 22800 (Mexico); Mujica, Raul [Instituto Nacional de Astrofisica, Optica y Electronica, Apdo. Postal 51 y 216, 72000 Tonantzintla, Puebla (Mexico)] [Instituto Nacional de Astrofisica, Optica y Electronica, Apdo. Postal 51 y 216, 72000 Tonantzintla, Puebla (Mexico); Heidt, Jochen; Mommert, Michael [ZAH, Landessternwarte Heidelberg, Koenigstuhl, D-69117 Heidelberg (Germany)] [ZAH, Landessternwarte Heidelberg, Koenigstuhl, D-69117 Heidelberg (Germany); Agudo, Ivan [Instituto Nacional de Astrofisica de Andalucia, CSIC, Apartado 3004, E-18080 Granada (Spain)] [Instituto Nacional de Astrofisica de Andalucia, CSIC, Apartado 3004, E-18080 Granada (Spain); Nilsson, Kari, E-mail: msorcia@astro.unam.mx [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland)] [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland)

2013-06-01T23:59:59.000Z

382

The Effect of Equilibrating Mounted Dental Stone Casts in Maximum Intercuspation on the Occlusal Harmony of an Indirect Restoration  

E-Print Network [OSTI]

The purpose of this study was to determine if equilibration of dental stone casts mounted in maximum intercuspation can improve occlusal harmony of a cast gold restoration. A dentoform mounted on an articulator with crown preparation on tooth #19...

Benson, Peter Andrew

2013-12-13T23:59:59.000Z

383

An Eddy Parameterization Based on Maximum Entropy Production with Application to Modeling of the Arctic Ocean Circulation  

Science Journals Connector (OSTI)

An eddy parameterization derived from statistical mechanics of potential vorticity is applied for inviscid shallow-water equations. The solution of a variational problem based on the maximum entropy production (MEP) principle provides, with some ...

Igor Polyakov

2001-08-01T23:59:59.000Z

384

An Exploratory Study of Variability in Safety  

E-Print Network [OSTI]

An Exploratory Study of Variability in Safety Culture among Clinician types and Patient Care of the current study was to (a) examine how different types of care providers viewed the safety culture of their unit, and (b) examine the relationship between hospital safety culture and patient satisfaction

von der Heydt, RĂĽdiger

385

SYNTHESIS: MODELING VARIABILITY AND CONSTRAINTS Rolf Carlson  

E-Print Network [OSTI]

SYNTHESIS: MODELING VARIABILITY AND CONSTRAINTS Rolf Carlson This is a modified version. Abstract This paper discusses some important topics in current speech synthesis research. Modeling of speaker characteristics and emotions are used as a examples of new trends in the speech synthesis field

Carlson, Rolf

386

Galactic Variable Sky with EGRET and GLAST  

SciTech Connect (OSTI)

The characteristics of the largely-unidentified Galactic sources of gamma rays that were detected by EGRET are reviewed. Proposed source populations that may have the correct spatial, spectral, luminosity, and variability properties to be the origins of the EGRET sources are also presented. Finally, the prospects for studying Galactic gamma-ray sources with the GLAST LAT are reviewed.

Digel, S.W.; /SLAC

2006-11-28T23:59:59.000Z

387

TimeVariable Photo-Evaporation of  

E-Print Network [OSTI]

TimeVariable Photo-Evaporation of Protoplanetary Disks Henry Throop (SwRI) John Bally (U. Colorado) #12;Takeaway: Photo-evaporation alters the disk structure in essentially unpredictable ways, because for disks formed at the same time in the same cluster. #12;30 Doradus: 100+ O/B stars Photo

Throop, Henry

388

Heart Rate Variability Malvin Carl Teich  

E-Print Network [OSTI]

Heart Rate Variability Malvin Carl Teich Boston University and Columbia University http, Grasmere, UK, 2005 #12;CONGESTIVE HEART FAILURE INABILITY OF HEART TO INCREASE CARDIAC OUTPUT IN PROPORTION of breath Swelling in legs General fatigue and weakness Clinical diagnostics: Ascultate heart Carotid pulse

Teich, Malvin C.

389

The QSO variability-luminosity-redshift relation  

Science Journals Connector (OSTI)

......to test Poissonian (or 'Christmas-tree') models for QSO variability...mean B-band luminosity in the light curve and a(LB) is its standard...comparison of the UV and optical light curves of NGC 4151 and 5548...spanning 16 yr. The rest-frame light curves are between 3.2 and......

Roberto Cid Fernandes; Jr; Itziar Aretxaga; Roberto Terlevich

1996-10-11T23:59:59.000Z

390

The Sun is an active, variable,  

E-Print Network [OSTI]

The Sun is an active, variable, magnetic star with oscillations on its surface and deep within its the physical processes of the Sun-Earth connection. Visit Us on the Web: Solar Terrestrial Probes Program: http://stp.gsfc.nasa.gov For More Information, See: Sun-Earth Connection: http://sec.gsfc.nasa.gov Living With a Star: http

Christian, Eric

391

Chapter 18: Variable Frequency Drive Evaluation Protocol  

SciTech Connect (OSTI)

An adjustable-speed drive (ASD) includes all devices that vary the speed of a rotating load, including those that vary the motor speed and linkage devices that allow constant motor speed while varying the load speed. The Variable Frequency Drive Evaluation Protocol presented here addresses evaluation issues for variable-frequency drives (VFDs) installed on commercial and industrial motor-driven centrifugal fans and pumps for which torque varies with speed. Constant torque load applications, such as those for positive displacement pumps, are not covered by this protocol. Other ASD devices, such as magnetic drive, eddy current drives, variable belt sheave drives, or direct current motor variable voltage drives, are also not addressed. The VFD is by far the most common type of ASD hardware. With VFD speed control on a centrifugal fan or pump motor, energy use follows the affinity laws, which state that the motor electricity demand is a cubic relationship to speed under ideal conditions. Therefore, if the motor runs at 75% speed, the motor demand will ideally be reduced to 42% of full load power; however, with other losses it is about 49% of full load power.

Romberger, J.

2014-11-01T23:59:59.000Z

392

Variable Light-Cone Theory of Gravity  

E-Print Network [OSTI]

We show how to reformulate Variable Speed of Light Theories (VSLT) in a covariant fashion as Variable Light-Cone Theories (VLCT) by introducing two vierbein bundles each associated with a distinct metric. The basic gravitational action relates to one bundle while matter propagates relative to the other in a conventional way. The variability of the speed of light is represented by the variability of the matter light-cone relative to the gravitational light-cone. The two bundles are related locally by an element M, of SL(4,R). The dynamics of the field M is that of a SL(4,R)-sigma model gauged with respect to local (orthochronous) Lorentz transformations on each of the bundles. Only the ``massless'' version of the model with a single new coupling, F, that has the same dimensions as Newton's constant $G_N$, is considered in this paper. When F vanishes the theory reduces to standard General Relativity. We verify that the modified Bianchi identities of the model are consistent with the standard conservation law for the matter energy-momentum tensor in its own background metric. The implications of the model for some simple applications are examined, the Newtonian limit, the flat FRW universe and the spherically symmetric static solution.

I. T. Drummond

1999-08-20T23:59:59.000Z

393

Variability viewpoint to describe reference architectures  

Science Journals Connector (OSTI)

Reference architectures have emerged as a special type of software architecture that achieves well-recognized understanding of specific domains. Their purpose is therefore to be a guidance for the development, standardization, and evolution of systems ... Keywords: architecture description, reference architecture, variability

Milena Guessi; Flavio Oquendo; Elisa Yumi Nakagawa

2014-04-01T23:59:59.000Z

394

Nonlocal theory of accelerated observers  

Science Journals Connector (OSTI)

A nonlocal theory of accelerated observers is developed on the basis of the hypothesis that an electromagnetic wave can never stand completely still with respect to an observer. In the eikonal approximation, the nonlocal theory reduces to the standard extension of Lorentz invariance to accelerated observers. The validity of the nonlocal theory would exclude the possibility of existence of any basic scalar field in nature. The observational consequences of this theory are briefly discussed.

Bahram Mashhoon

1993-05-01T23:59:59.000Z

395

NEAR-INFRARED VARIABILITY IN YOUNG STARS IN CYGNUS OB7  

SciTech Connect (OSTI)

We present the first results from a 124 night J, H, K near-infrared monitoring campaign of the dark cloud L 1003 in Cygnus OB7, an active star-forming region. Using three seasons of UKIRT observations spanning 1.5 years, we obtained high-quality photometry on 9200 stars down to J = 17 mag, with photometric uncertainty better than 0.04 mag. On the basis of near-infrared excesses from disks, we identify 30 pre-main-sequence stars, including 24 which are newly discovered. We analyze those stars and find that the NIR excesses are significantly variable. All 9200 stars were monitored for photometric variability; among the field star population, {approx}160 exhibited near-infrared variability (1.7% of the sample). Of the 30 young stellar objects (YSOs), 28 of them (93%) are variable at a significant level. Of the 30 YSOs, twenty-five have near-infrared excess consistent with simple disk-plus-star classical T Tauri models. Nine of these (36%) drift in color space over the course of these observations and/or since Two Micron All Sky Survey observations such that they cross the boundary defining the NIR excess criteria; effectively, they have a transient near-infrared excess. Thus, time-series JHK observations can be used to obtain a more complete sample of disk-bearing stars than single-epoch JHK observations. About half of the YSOs have color-space variations parallel to either the classical T Tauri star locus or a hybrid track which includes the dust reddening trajectory. This indicates that the NIR variability in YSOs that possess accretion disks arises from a combination of variable extinction and changes in the inner accretion disk: either in accretion rate, central hole size, and/or the inclination of the inner disk. While some variability may be due to stellar rotation, the level of variability on the individual stars can exceed a magnitude. This is a strong empirical suggestion that protoplanetary disks are quite dynamic and exhibit more complex activity on short timescales than is attributable to rotation alone or captured in static disk models.

Rice, Thomas S. [Department of Astronomy, Harvard University, 60 Garden Street, Cambridge, MA 02138 (United States); Wolk, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Aspin, Colin [Institute for Astronomy, University of Hawaii at Manoa, 640 N Aohoku Pl, Hilo, HI 96720 (United States)

2012-08-10T23:59:59.000Z

396

An empirical analysis of the spatial variability of atmospheric CO2: Implications for inverse analyses and space-borne sensors  

E-Print Network [OSTI]

analyses and space-borne sensors J. C. Lin,1 C. Gerbig,1 B. C. Daube,1 S. C. Wofsy,1 A. E. Andrews,2 S. A observations and spatial averages simulated by models or observed from space-borne sensors surface fluxes or to validate space-borne sensors. We empirically derive the spatial variability

Lin, John Chun-Han

397

Field observations and lessons learned  

SciTech Connect (OSTI)

This presentation outlines observations and lessons learned from the Megaports program. It provides: (1) details of field and technical observations collected during LANL field activities at ports around the world and details of observations collected during radiation detections system testing at Los Alamos National Laboratory; (2) provides suggestions for improvement and efficiency; and (3) discusses possible program execution changes for more effective operations.

Nielsen, Joh B [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

398

Optical Variability of Infrared Power Law-Selected Galaxies & X-ray Sources in the GOODS-South Field  

E-Print Network [OSTI]

We investigate the use of optical variability to identify and study Active Galactic Nuclei (AGN) in the GOODS-South field. A sample of 22 mid-infrared power law sources and 102 X-ray sources with optical counterparts in the HST ACS images were selected. Each object is classified with a variability significance value related to the standard deviation of its magnitude in five epochs separated by 45-day intervals. The variability significance is compared to the optical, mid-IR, and X-ray properties of the sources. We find that 26% of all AGN candidates (either X-ray- or mid-IR-selected) are optical variables. The fraction of optical variables increases to 51% when considering sources with soft X-ray band ratios. For the mid-IR AGN candidates which have multiwavelength SEDs, we find optical variability for 64% of those classified with SEDs like Broad Line AGNs. While mostly unobscured AGN appear to have the most significant optical variability, some of the more obscured AGNs are also observed as variables. In particular, we find two mid-IR power law-selected AGN candidates without X-ray emission that display optical variability, confirming their AGN nature.

Alison Klesman; Vicki Sarajedini

2007-05-07T23:59:59.000Z

399

Parametric study on maximum transportable distance and cost for thermal energy transportation using various coolants  

SciTech Connect (OSTI)

The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as district heating, desalination, hydrogen production and other process heat applications, etc. The process heat industry/facilities will be located outside the nuclear island due to safety measures. This thermal energy from the reactor has to be transported a fair distance. In this study, analytical analysis was conducted to identify the maximum distance that thermal energy could be transported using various coolants such as molten-salts, helium and water by varying the pipe diameter and mass flow rate. The cost required to transport each coolant was also analyzed. The coolants analyzed are molten salts (such as: KClMgCl2, LiF-NaF-KF (FLiNaK) and KF-ZrF4), helium and water. Fluoride salts are superior because of better heat transport characteristics but chloride salts are most economical for higher temperature transportation purposes. For lower temperature water is a possible alternative when compared with He, because low pressure He requires higher pumping power which makes the process very inefficient and economically not viable for both low and high temperature application.

Su-Jong Yoon; Piyush Sabharwall

2014-07-01T23:59:59.000Z

400

Maximum Reasonable Radioxenon Releases from Medical Isotope Production Facilities and Their Effect on Monitoring Nuclear Explosions  

SciTech Connect (OSTI)

Fission gases such as 133Xe are used extensively for monitoring the world for signs of nuclear testing in systems such as the International Monitoring System (IMS). These gases are also produced by nuclear reactors and by fission production of 99Mo for medical use. Recently, medical isotope production facilities have been identified as the major contributor to the background of radioactive xenon isotopes (radioxenon) in the atmosphere (Saey, et al., 2009). These releases pose a potential future problem for monitoring nuclear explosions if not addressed. As a starting point, a maximum acceptable daily xenon emission rate was calculated, that is both scientifically defendable as not adversely affecting the IMS, but also consistent with what is possible to achieve in an operational environment. This study concludes that an emission of 5×109 Bq/day from a medical isotope production facility would be both an acceptable upper limit from the perspective of minimal impact to monitoring stations, but also appears to be an achievable limit for large isotope producers.

Bowyer, Ted W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Kephart, Rosara F.; Eslinger, Paul W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Friese, Judah I. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Miley, Harry S. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Saey, Paul R. [Vienna University of Technology, Atomic Institute of the Austrian Universities, Vienna (Austria)

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Thermal properties for the thermal-hydraulics analyses of the BR2 maximum nominal heat flux.  

SciTech Connect (OSTI)

This memo describes the assumptions and references used in determining the thermal properties for the various materials used in the BR2 HEU (93% enriched in {sup 235}U) to LEU (19.75% enriched in {sup 235}U) conversion feasibility analysis. More specifically, this memo focuses on the materials contained within the pressure vessel (PV), i.e., the materials that are most relevant to the study of impact of the change of fuel from HEU to LEU. This section is regrouping all of the thermal property tables. Section 2 provides a summary of the thermal properties in form of tables while the following sections present the justification of these values. Section 3 presents a brief background on the approach used to evaluate the thermal properties of the dispersion fuel meat and specific heat capacity. Sections 4 to 7 discuss the material properties for the following materials: (i) aluminum, (ii) dispersion fuel meat (UAlx-Al and U-7Mo-Al), (iii) beryllium, and (iv) stainless steel. Section 8 discusses the impact of irradiation on material properties. Section 9 summarizes the material properties for typical operating temperatures. Appendix A elaborates on how to calculate dispersed phase's volume fraction. Appendix B shows the evolution of the BR2 maximum heat flux with burnup.

Dionne, B.; Kim, Y. S.; Hofman, G. L. (Nuclear Engineering Division) [Nuclear Engineering Division

2011-05-23T23:59:59.000Z

402

The wind potential impact on the maximum wind energy penetration in autonomous electrical grids  

Science Journals Connector (OSTI)

According to long-term wind speed measurements the Aegean Archipelago possesses excellent wind potential, hence properly designed wind energy applications can substantially contribute to fulfill the energy requirements of the island societies. On top of this, in most islands the electricity production cost is extremely high, while significant insufficient power supply problems are often encountered, especially during the summer. Unfortunately, the stochastic behaviour of the wind and the important fluctuations of daily and seasonal electricity load pose a strict penetration limit for the contribution of wind energy in the corresponding load demand. The application of this limit is necessary in order to avoid hazardous electricity grid fluctuations and to protect the existing thermal power units from operating near or below their technical minima. In this context, the main target of the proposed study is to present an integrated methodology able to estimate the maximum wind energy penetration in autonomous electrical grids on the basis of the available wind potential existing in the Aegean Archipelago area. For this purpose a large number of representative wind potential types have been investigated and interesting conclusions have been derived.

J.K. Kaldellis

2008-01-01T23:59:59.000Z

403

Observation Wells | Open Energy Information  

Open Energy Info (EERE)

Observation Wells Observation Wells Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Observation Wells Details Activities (7) Areas (7) Regions (0) NEPA(15) Exploration Technique Information Exploration Group: Drilling Techniques Exploration Sub Group: Development Drilling Parent Exploration Technique: Development Drilling Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Total dissolved solids, fluid pressure, flow rates, and flow direction Thermal: Monitors temperature of circulating fluids Dictionary.png Observation Wells: An observation well is used to monitor important hydrologic parameters in a geothermal system that can indicate performance, longevity, and transient processes. Other definitions:Wikipedia Reegle

404

Distinguishing the effects of internal and forced atmospheric variability in climate networks  

E-Print Network [OSTI]

The fact that the Earth climate is a highly complex dynamical system is well-known. In the last few decades a lot of effort has been focused on understanding how climate phenomena in one geographical region affects the climate of other regions. Complex networks are a powerful framework for identifying climate interdependencies. To further exploit the knowledge of the links uncovered via the network analysis (for, e.g., improvements in prediction), a good understanding of the physical mechanisms underlying these links is required. Here we focus in understanding the role of atmospheric variability, and construct climate networks representing internal and forced variability. In the connectivity of these networks we assess the influence of two main indices, NINO3.4 and the North Atlantic Oscillation (NAO), by calculating the networks from time-series where these indices were linearly removed. We find that the connectivity of the forced variability network is heavily affected by ``El Ni\\~no'': removing the NINO3.4 index yields a general loss of connectivity; even teleconnections between regions far away from the equatorial Pacific ocean are lost, suggesting that these regions are not directly linked, but rather, are indirectly interconnected via ``El Ni\\~no'', particularly on interannual time scales. On the contrary, in the internal variability network (independent of sea surface temperature forcing) we find that the links are significantly affected by NAO with a maximum in intra-annual time scales. While the strongest non-local links found are those forced by the ocean, we show that there are also strong teleconnections due to internal atmospheric variability.

J. Ignacio Deza; Cristina Masoller; Marcelo Barreiro

2013-11-13T23:59:59.000Z

405

Spectral Variability from the Patchy Atmospheres of T and Y Dwarfs  

E-Print Network [OSTI]

Brown dwarfs of a variety of spectral types have been observed to be photometrically variable. Previous studies have focused on objects at the L/T transition, where the iron and silicate clouds in L dwarfs break up or dissipate. However, objects outside of this transitional effective temperature regime also exhibit variability. Here, we present models for mid-late T dwarfs and Y dwarfs. We present models that include patchy salt and sulfide clouds as well as water clouds for the Y dwarfs. We find that for objects over 375 K, patchy cloud opacity would generate the largest amplitude variability within near-infrared spectral windows. For objects under 375 K, water clouds also become important and generate larger amplitude variability in the mid-infrared. We also present models in which we perturb the temperature structure at different pressure levels of the atmosphere to simulate hot spots. These models show the most variability in the absorption features between spectral windows. The variability is strongest a...

Morley, Caroline V; Fortney, Jonathan J; Lupu, Roxana

2014-01-01T23:59:59.000Z

406

Modeling variable density effects in turbulent flames -- Some basic considerations  

SciTech Connect (OSTI)

The paper discusses the basic physical phenomena involved in pressure-density interactions, and presents models of pressure-velocity, pressure-scalar, baroclinic and dilatation effects for variable density low Mach-number turbulence. Their implementation in the {kappa}-{epsilon} framework is then described and their performance evaluated. The models assume that both scalar transport and turbulence generation arising from pressure-density interactions in flames are caused by the motion of large scale turbulent thermals superposed on the normal turbulence mechanism. The velocity of the thermals is related directly to the mean pressure gradient and local density differences in the flames. It is furthermore assumed that the correction for dilatation effects in the {kappa}-{epsilon} system can be determined from the constraint of conservation of the angular momentum of turbulence per unit mass. Simple corrections of the {kappa}-{epsilon} system are proposed for fast chemistry diffusion and premixed flames subject to variable pressure gradients, which offer substantial improvements in the predictions of the flames. some problems remain, particularly in predictions of turbulence in premixed flames, owing to large scale instabilities of the flames observed in the experiments.

Chomiak, J.; Nisbet, J.R. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics] [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics

1995-08-01T23:59:59.000Z

407

ANOMALOUS LOW STATES AND LONG-TERM VARIABILITY IN THE BLACK HOLE BINARY LMC X-3  

SciTech Connect (OSTI)

Rossi X-ray Timing Explorer observations of the black hole binary LMC X-3 reveal an extended very low X-ray state lasting from 2003 December 13 until 2004 March 18, unprecedented both in terms of its low luminosity (>15 times fainter than ever before seen in this source) and long duration ({approx}3 times longer than a typical low/hard state excursion). During this event little to no source variability is observed on timescales of {approx}hours-weeks, and the X-ray spectrum implies an upper limit of 1.2 Multiplication-Sign 10{sup 35} erg s{sup -1}. Five years later another extended low state occurs, lasting from 2008 December 11 until 2009 June 17. This event lasts nearly twice as long as the first, and while significant variability is observed, the source remains reliably in the low/hard spectral state for the {approx}188 day duration. These episodes share some characteristics with the 'anomalous low states' in the neutron star binary Her X-1. The average period and amplitude of the variability of LMC X-3 have different values between these episodes. We characterize the long-term variability of LMC X-3 before and after the two events using conventional and nonlinear time series analysis methods, and show that, as is the case in Her X-1, the characteristic amplitude of the variability is related to its characteristic timescale. Furthermore, the relation is in the same direction in both systems. This suggests that a similar mechanism gives rise to the long-term variability, which in the case of Her X-1 is reliably modeled with a tilted, warped precessing accretion disk.

Smale, Alan P.; Boyd, Patricia T., E-mail: alan.smale@nasa.gov, E-mail: padi.boyd@nasa.gov [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-10T23:59:59.000Z

408

Observations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Multiple Magnetic Islands in the Core of a Reversed Field Pinch P. Franz, 1,2 L. Marrelli, 1,2 P. Piovesan, 1,2 B. E. Chapman, 3 P. Martin, 1,2 I. Predebon, 1,2 G. Spizzo, 1 R....

409

Observation  

Office of Scientific and Technical Information (OSTI)

structure of K x Fe 2-y Se 2 . (a) FS mapping with the 2-Fe BZ boundary marked in green. (b),(d) Spec- tral images and (c),(e) second derivative in energy along the -X...

410

Observation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

52.25.Fi, 52.70.La Energy loss in magnetically confined toroidal plasmas for thermonuclear fusion research is dominated by fluc- tuation driven transport 1. In the...

411

Assimilation of wind profiler observations and its impact on three-dimensional transport of ozone over the Southeast Korean Peninsula  

Science Journals Connector (OSTI)

Abstract In order to investigate the impact of data assimilation on the assessment of ozone concentration in inland regions in the eastern area of the Korean Peninsula, several numerical experiments have been carried out using the Weather Research and Forecasting (WRF) model to estimate atmospheric circulations and the Community Multiscale Air Quality (CMAQ) model to assess air quality. Observations of wind that are assimilated into the modeling system are obtained from a wind profiler located at Changwon (CW), which is an urbanized coastal region in the Korean Peninsula. The simulated wind and temperature that is related to a well-developed sea breeze circulation are more consistent with observations in the experiment with dada assimilation than that without the assimilation. The ozone concentrations at both the coastal area of CW and the inland region of DG are well reproduced in the simulation with application of profiler data assimilation. Results from experiments without data assimilation are less realistic than that from the experiment with data assimilation. However, the improvement in simulation of meteorological variables and ozone concentration due to data assimilation is greater in the inland area than in the coastal area, where the wind profiler is located. The ozone concentration in CW changes only over a limited area and below the altitude of 1 km with a maximum change of 25 ppb. In contrast, the simulated ozone concentration in DG has been improved from the ground to upper levels of the planetary boundary layer (PBL), despite the fact that the observations are collected and assimilated into the model at the coastal region. Based on the results of process analysis, we find that the horizontal and vertical transportation of ozone related to the sea-breeze is more important than the local contribution of chemical production in determining the ozone concentration over the inland area. Therefore, observations of wind profiles in the coastal area and assimilation of these observations into the modeling system are important in our modeling study to assess the ozone concentration in inland areas. The assimilation of observations can greatly improve the model performance in both circulation simulation and ozone concentration simulation.

Soon-Young Park; Soon-Hwan Lee; Hwa Woon Lee

2014-01-01T23:59:59.000Z

412

Preparing the COROT space mission: new variable stars in the galactic Anticenter direction  

E-Print Network [OSTI]

The activities related to the preparation of the asteroseismic, photometric space mission COROT are described. Photoelectric observations, wide--field CCD photometry, uvbyB calibrations and further time--series have been obtained at different observatories and telescopes. They have been planned to complete the COROT programme in the direction of the galactic Anticenter. In addition to suitable asteroseismic targets covering the different evolutionary stages between ZAMS and TAMS, we discovered several other variable stars, both pulsating and geometrical. We compared results on the incidence of variability in the galactic Center and Anticenter directions. Physical parameters have been obtained and evolutionary tracks fitting them have been calculated. The peculiarities of some individual stars alre pointed out. Paper based on observations collected at the San Pedro Martir, Sierra Nevada, Teide, La Silla, Haute-Provence and Roque de Los Muchachos (Telescopio Nazionale Galileo and Mercator telescopes) observator...

Poretti, E; Amado, P J; Belmonte, J A; Garrido, R; Martin-Ruiz, S; Uytterhoeven, K; Catala, C; Lebreton, Y; Michel, E; Suárez, J C; Aerts, C; Creevey, O; Goupil, M J; Mantegazza, L; Mathias, P; Rainer, M; Weiss, W W

2005-01-01T23:59:59.000Z

413

Maximum and minimum stable random packings of Platonic solids Jessica Baker and Arshad Kudrolli  

E-Print Network [OSTI]

of steel ball bearings 3 . In fact, work in the last decade has shown that random packing itself of the tetrahedrons 8,9 . In the case of tetrahedrons, disordered wagon-wheel packings were initially found to pack were said to be 0.76 .02 if the observed packings were extrapolated to infinite systems, but the pro

Kudrolli, Arshad

414

The VISTA Variables in the Via Lactea survey: A first glance on stellar variability  

E-Print Network [OSTI]

VISTA Variables in the Via Lactea (VVV) is an ESO public near-infrared variability survey of the Galactic bulge and an adjacent area of the southern mid-plane. It will produce a deep atlas in the ZYJHKs filters, and a Ks-band time-series database of ~10^9 point sources, among which >~10^6 are expected to be variable. One of VVV's immediate scientific goals is to provide accurate light curves of primary distance indicators, such as RR Lyrae stars, and utilize these data to produce a 3-D map of the surveyed area and, ultimately, trace the structure of the inner Galaxy. We give, based on the first ~1.5 years of the 5-yr-long survey, an early assessment on the basic properties and the overall quality of the VVV photometric time-series, and use these data to put an estimate of the fraction of variable stellar sources.

Dekany, I; Minniti, D

2011-01-01T23:59:59.000Z

415

Variables Affecting Economic Development of Wind Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Variables Affecting Economic Variables Affecting Economic Development of Wind Energy E. Lantz and S. Tegen National Renewable Energy Laboratory Presented at WINDPOWER 2008 Houston, Texas June 1-4, 2008 Conference Paper NREL/CP-500-43506 July 2008 NREL is operated by Midwest Research Institute â—Ź Battelle Contract No. DE-AC36-99-GO10337 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

416

Thermodynamics in variable speed of light theories  

SciTech Connect (OSTI)

The perfect fluid in the context of a covariant variable speed of light theory proposed by J. Magueijo is studied. On the one hand the modified first law of thermodynamics together with a recipe to obtain equations of state are obtained. On the other hand the Newtonian limit is performed to obtain the nonrelativistic hydrostatic equilibrium equation for the theory. The results obtained are used to determine the time variation of the radius of Mercury induced by the variability of the speed of light (c), and the scalar contribution to the luminosity of white dwarfs. Using a bound for the change of that radius and combining it with an upper limit for the variation of the fine structure constant, a bound on the time variation of c is set. An independent bound is obtained from luminosity estimates for Stein 2015B.

Racker, Juan [CONICET, Centro Atomico Bariloche, Avenida Bustillo 9500 (8400), San Carlos De Bariloche (Argentina); Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900), La Plata (Argentina); Sisterna, Pablo [Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350 (7600), Mar del Plata (Argentina); Vucetich, Hector [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N (1900), La Plata (Argentina)

2009-10-15T23:59:59.000Z

417

Variable aperture collimator for high energy radiation  

DOE Patents [OSTI]

An apparatus is disclosed providing a variable aperture energy beam collimator. A plurality of beam opaque blocks are in sliding interface edge contact to form a variable aperture. The blocks may be offset at the apex angle to provide a non-equilateral aperture. A plurality of collimator block assemblies may be employed for providing a channel defining a collimated beam. Adjacent assemblies are inverted front-to-back with respect to one another for preventing noncollimated energy from emerging from the apparatus. An adjustment mechanism comprises a cable attached to at least one block and a hand wheel mechanism for operating the cable. The blocks are supported by guide rods engaging slide brackets on the blocks. The guide rods are pivotally connected at each end to intermediate actuators supported on rotatable shafts to change the shape of the aperture. A divergent collimated beam may be obtained by adjusting the apertures of adjacent stages to be unequal.

Hill, Ronald A. (Albuquerque, NM)

1984-05-22T23:59:59.000Z

418

Thermodynamics in variable speed of light theories  

E-Print Network [OSTI]

The perfect fluid in the context of a covariant variable speed of light theory proposed by J. Magueijo is studied. On the one hand the modified first law of thermodynamics together with a recipe to obtain equations of state are obtained. On the other hand the Newtonian limit is performed to obtain the nonrelativistic hydrostatic equilibrium equation for the theory. The results obtained are used to determine the time variation of the radius of Mercury induced by the variability of the speed of light ($c$), and the scalar contribution to the luminosity of white dwarfs. Using a bound for the change of that radius and combining it with an upper limit for the variation of the fine structure constant, a bound on the time variation of $c$ is set. An independent bound is obtained from luminosity estimates for Stein 2015B.

Juan Racker; Pablo Sisterna; Hector Vucetich

2007-11-06T23:59:59.000Z

419

Teleportation-Based Continuous Variable Quantum Cryptography  

E-Print Network [OSTI]

We show a continuous variable (CV) quantum key distribution (QKD) scheme based on the CV quantum teleportation of coherent states that yields a raw secret key made up of discrete variables for both Alice and Bob. This protocol preserves the efficient detection schemes of current CV technology (no single-photon detection techniques) and, at the same time, has efficient error correction and privacy amplification schemes due to its binary discrete key. In particular, it is secure for any value of the transmission efficiency of the optical line used by Alice to share entangled two-mode squeezed states with Bob (no 3 dB or 50% loss limitation characteristic of beam splitting attacks). The present CVQKD protocol works deterministically (no postselection needed) with efficient direct reconciliation techniques (no reverse reconciliation) in order to generate a secure key, even at the surprisingly 100% loss case.

F. S. Luiz; Gustavo Rigolin

2014-08-21T23:59:59.000Z

420

Buoyancy-generated variable-density turbulence  

SciTech Connect (OSTI)

Because of the importance of turbulence mixing in many applications, a number of turbulence mixing models have been proposed for variable- density flows. These engineering models (one- point statistical models) typically include the transport of the turbulent kinetic energy and the turbulent energy dissipation rate (i.e., k - {epsilon} models). The model presented by Besnard, Harlow, Rauenzahn and Zemach (1992) (herein referred to as BHRZ) is a one-point model intended to describe variable-density turbulent flows. Transport equations for the Reynolds stress tensor, R{sub ij}, and the turbulent energy dissipation rate, the density-velocity correlation, a{sub i}, and the density-specific volume correlation, b are derived. This model employs- techniques and concepts from incompressible, constant- density turbulence modeling and incorporates ideas from two-phase flow models. Clark and Spitz (1994) present a two-point model for variable-density turbulence. Their derivation is based on transport equations that, are based 0481 on two-point- generalizations of R{sub ij}, a{sub ij}, and b. These equations are Fourier transformed with respect to the separation distance between the two points. Transport equations are derived for R{sub ij}, a{sub i}, b. As in the one-point model, this model contains many ad-hoc assumptions and unknown model coefficients that must be determined by comparison with experimental and numerical data. However, the two-point formalism requires fewer equilibrium assumptions then does a single-point model. Our primary concern in this paper lies in the nonlinear processes of turbulence and the influence of large density variations (not within the Boussinesq limit) on these processes. To. isolate the effects of variable-density on the turbulence we restrict our flow to be incompressible, statistically homogeneous buoyancy-generated. turbulence. To our knowledge there have not been any simulations reported for this problem.

Sandoval, D.L.; Clark, T.T.; Riley, J.J.

1996-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

The dynamics of variable-density turbulence  

SciTech Connect (OSTI)

The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field is, in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 128{sup 3} grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations (such that the Boussinesq approximation is not valid). In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For this case, the pdf of the density becomes asymmetric about its mean value during the early stages of its evolution. It is argued that these asymmetries in the pdf of the density field are due to different entrainment rates, into the mixing region, that favor the high speed fluid.

Sandoval, D.L.

1995-11-01T23:59:59.000Z

422

Multivector Functions of a Multivector Variable  

E-Print Network [OSTI]

In this paper we develop with considerable details a theory of multivector functions of a $p$-vector variable. The concepts of limit, continuity and differentiability are rigorously studied. Several important types of derivatives for these multivector functions are introduced, as e.g., the $A$% -directional derivative (where $A$ is a $p$-vector) and the generalized concepts of curl, divergence and gradient. The derivation rules for different types of products of multivector functions and for compositon of multivector functions are proved.

A. M. Moya; V. V. Fernández; W. A. Rodrigues Jr

2002-12-18T23:59:59.000Z

423

Hidden Variables and Quantum Statistics Nature  

E-Print Network [OSTI]

It is shown that the nature of quantum statistics can be clarified by assuming the existence of a background of random gravitational fields and waves, distributed isotropically in the space. This background is responsible for correlating phases of oscillations of identical microobjects. If such a background of random gravitational fields and waves is considered as hidden variables then taking it into account leads to the Bell-type inequalities that are fairly consistent with the experimental data.

T. F. Kamalov

2007-03-14T23:59:59.000Z

424

Variable Row Spacing of Irrigated Cotton.  

E-Print Network [OSTI]

B-1 lr August 19; aria ble Row Spacing of Irrigated Cotton I as A&M University Texas Agricultural Experiment Station . H. 0. Kunkel, Acting Director, College Station, Texa! Summary Six years' research in the Trans-Pecos area with "variable... row spacing" (VRS), new irrigated cotton row-spacing patterns, is reported. The new system consists of alternate close and ~ricle spaced rows, with narrow irrigation furrows between the close row spacings only. The wide spac- ings serve as dry...

Longenecker, D. E.; Thaxton, E. L. Jr.; Hefner, J. J.; Lyerly, P. J.

1970-01-01T23:59:59.000Z

425

Teleportation using continuous variable quantum cloning machine  

E-Print Network [OSTI]

We show that an unknown quantum state in phase space can be teleported via three-mode entanglement generated by continuous variable quantum cloning machine (transformation). Further, proceeding with our teleportation protocol we are able to improve the fidelity of teleportation obtained by Loock et.al. [Phys.Rev.Lett. 84, 3482(2000)]. Also we study here the entanglement between the two output copies from cloning machine.

Satyabrata Adhikari

2008-02-15T23:59:59.000Z

426

Is Salinity Variability a Benthic Disturbance?  

E-Print Network [OSTI]

include: salinity, pH, dissolved oxygen, temperature, conductivity, oxidation-reduction potential, and depth (Monatgna and Kalke 1992, 1995). Measurements were collected both at depth (0.1 m above bay bottom) and at the surface using a sonde... IS SALINITY VARIABILITY A BENTHIC DISTURBANCE? A Thesis by AMANDA D. VAN DIGGELEN Submitted to the Office of Graduate and Professional Studies of Texas A&M University and the Graduate Faculty of The Texas A&M University – Corpus...

Van Diggelen, Amanda

2014-05-07T23:59:59.000Z

427

Analysis of two basic variables of timeout  

E-Print Network [OSTI]

in reducing the rate of a designated behavior. Timeout from positive reinforcement is a behavior modification technique in which positive reinforcers are withdrawn for a period of time following a target response (White, Nielsen, and Johnson, 1972... variable (White, Nielsen, and Johnson, 1972) did not reach a decisive conclusion because of a sequencing problem in the method. The effects of three different timeout durations were investigated in a group of 20 retarded, institution- alized subjects...

Zella, William Francis

2012-06-07T23:59:59.000Z

428

HVAC's Variable Refrigerant Flow (VRF) Technology  

E-Print Network [OSTI]

1 Comfort by Design Steve Jones Commercial Sales Manager for Mitsubishi Southwest Business Unit HVAC?s Variable Refrigerant Flow (VRF) Technology HVAC Industry Overview HVAC Market Dollar Volume $18 Billion Source:;NABH Research....2M Systems Ductless is a small percent of the U.S. HVAC market but current building and energy usage trends indicate a large growth opportunity Determining the Proper Application Worldwide Usage-Opportunity Window Unitary Chillers...

Jones, S.

2012-01-01T23:59:59.000Z

429

Intensive Variables & Nanostructuring in Magnetostructural Materials  

SciTech Connect (OSTI)

Over the course of this project, fundamental inquiry was carried out to investigate, understand and predict the effects of intensive variables, including the structural scale, on magnetostructural phase transitions in the model system of equiatomic FeRh. These transitions comprise simultaneous magnetic and structural phase changes that have their origins in very strong orbital-lattice coupling and thus may be driven by a plurality of effects.

Lewis, Laura

2014-08-13T23:59:59.000Z

430

Globally competitive variable-speed wind turbines  

SciTech Connect (OSTI)

This paper focuses on the design issues which must be addressed if variable-speed wind turbines are to compete in the global marketplace. The paper examines how component-specific design decisions must be made on a system level if an optimized system is to be the result. The relationships among the blades, the generator and the utility interface are considered in detail, using the conceptual design of a 12 kW variable-speed wind turbine (the AOC 8/12) as a running example. The turbine is based on a direct-drive variable-reluctance generator (VRG), a single- or three-phase utility interface as appropriate, and a three-bladed rotor with fixed pitch. A preliminary turbine specification is provided, along with candidate power-speed curves and annual energy output. This paper documents the continuing development and commercialization of this technology which is being taken from the proof-of-concept stage and is now headed for field testing.

Torrey, D.A. [Rensselaer Polytechnic Institute, Troy, NY (United States); Childs, S.E.; Johnson, B.; Carter, J. [Atlantic Orient Corp., Norwich, VT (United States)

1995-12-31T23:59:59.000Z

431

Observations of deep scattering layers in the Gulf of Mexico  

E-Print Network [OSTI]

layer (DSL), in the Gulf of Mexico, in reference to; ~ the distribution of the DSL during the past three years, ~ average and maximum rates of ascent and descent, ~ correlation between DSL motion during the total solar eclipse in March, 1970... was noted and discussed but not specifically identified as such. D. Reaction to Solar Eclipse Reported here are the results of observations of the DSL in the Gulf of Mexico during a three-day period which included the day of the total solar eclipse (TSE...

Thompson, Ronald Curtis

2012-06-07T23:59:59.000Z

432

Controls on morphological variability and role of stream power distribution pattern, Yamuna River, western India  

Science Journals Connector (OSTI)

Abstract Understanding the controls on the morphological variability of river systems constitutes one of the fundamental questions in geomorphic investigation. Channel morphology is an important indicator of river processes and is of significance for mapping the hydrology-ecologic connectivity in a river system and for predicting the future trajectory of river health in response to external forcings. This paper documents the spatial morphological variability and its natural and anthropogenic controls for the Yamuna River, a major tributary of the Ganga River, India. The Yamuna River runs through a major urban centre i.e. Delhi National Capital Region. The Yamuna River was divided into eight geomorphically distinct reaches on the basis of the assemblages of geomorphic units and the association of landscape, valley and floodplain settings. The morphological variability was analysed through stream power distribution and sediment load data at various stations. Stream power distribution of the Yamuna River basin is characterised by a non-linear pattern that was used to distinguish (a) high energy ‘natural’ upstream reaches, (b) ‘anthropogenically altered’, low energy middle stream reaches, and (c) ‘rejuvenated’ downstream reaches again with higher stream power. The relationship between stream power and channel morphology in these reaches was integrated with sediment load data to define the maximum flow efficiency (MFE) as the threshold for geomorphic transition. This analysis supports the continuity of river processes and the significance of a holistic, basin-scale approach rather than isolated local scale analysis in river studies.

Nupur Bawa; Vikrant Jain; Shashank Shekhar; Niraj Kumar; Vikas Jyani

2014-01-01T23:59:59.000Z

433

ARM - Mobile Aerosol Observing System  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

FacilitiesMobile Aerosol Observing System FacilitiesMobile Aerosol Observing System AMF Information Science Architecture Baseline Instruments AMF1 AMF2 AMF3 Data Operations AMF Fact Sheet Images Contacts AMF Deployments Hyytiälä, Finland, 2014 Manacapuru, Brazil, 2014 Oliktok Point, Alaska, 2013 Los Angeles, California, to Honolulu, Hawaii, 2012 Cape Cod, Massachusetts, 2012 Gan Island, Maldives, 2011 Ganges Valley, India, 2011 Steamboat Springs, Colorado, 2010 Graciosa Island, Azores, 2009-2010 Shouxian, China, 2008 Black Forest, Germany, 2007 Niamey, Niger, 2006 Point Reyes, California, 2005 Mobile Aerosol Observing System Intensive aerosol observations conducted on the campus of Brookhaven National Laboratory on Long Island, New York, using the ARM Mobile Aerosol Observing System. Intensive aerosol observations conducted on the campus of Brookhaven

434

NS&T MANAGEMENT OBSERVATIONS  

SciTech Connect (OSTI)

The INL Management Observation Program (MOP) is designed to improve managers and supervisors understanding of work being performed by employees and the barriers impacting their success. The MOP also increases workers understanding of managements’ expectations as they relate to safety, security, quality, and work performance. Management observations (observations) are designed to improve the relationship and trust between employees and managers through increased engagement and interactions between managers and researchers in the field. As part of continuous improvement, NS&T management took initiative to focus on the participation and quality of observations in FY 14. This quarterly report is intended to (a) summarize the participation and quality of management’s observations, (b) assess observations for commonalities or trends related to facility or process barriers impacting research, and (c) provide feedback and make recommendations for improvements NS&T’s MOP.

Gianotto, David

2014-06-01T23:59:59.000Z

435

The All Sky Automated Survey. The Catalog of Bright Variable Stars in the I-band, South of Declination +28  

E-Print Network [OSTI]

This paper presents the results of our extensive search for the bright variable stars in approximately 30000 square degrees of the south sky in the I-band data collected by 9 deg x 9 deg camera of the All Sky Automated Survey between 2002 and 2009. Lists of over 27000 variable stars brighter than 9 mag at maximum light, with amplitudes ranging from 0.02 mag to 7 mag and variability time-scales from hours to years, as well as corresponding light curves are provided. Automated classification algorithm based on stellar properties (period, Fourier coefficients, 2MASS J, H, K, colors, ASAS V-band data) was used to roughly classify objects. Despite low spatial resolution of the ASAS data (~15 arcs) we cross-identified all objects with other available data sources. Coordinates of the most probable 2MASS counterparts are provided. 27705 stars brighter than I=9 mag were found to be variable, of which 7842 objects were detected to be variable for the first time. Brief statistics and discussion of the presented data is ...

Sitek, Monika

2014-01-01T23:59:59.000Z

436

Natural Gas Variability In California: Environmental Impacts And Device  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Natural Gas Variability In California: Environmental Impacts And Device Natural Gas Variability In California: Environmental Impacts And Device Performance - Experimental Evaluation Of Installed Cooking Exhaust Fan Performance Title Natural Gas Variability In California: Environmental Impacts And Device Performance - Experimental Evaluation Of Installed Cooking Exhaust Fan Performance Publication Type Report Year of Publication 2011 Authors Singer, Brett C., William W. Delp, and Michael G. Apte Publisher Lawrence Berkeley National Laboratory City Berkeley, CA Keywords energy analysis and environmental impacts department Abstract The installed performance of cooking exhaust fans was evaluated through residential field experiments conducted on a sample of 15 devices varying in design and other characteristics. The sample included two rear downdraft systems, two under-cabinet microwave over range units, three different installations of an under-cabinet model with grease screens across the bottom and no capture hood, two devices with grease screens covering the bottom of a large capture hood (one under-cabinet, one wall-mount chimney), four under-cabinet open hoods, and two open hoods with chimney mounts over islands. Performance assessment included measurement of airflow and sound levels across fan settings and experiments to quantify the contemporaneous capture efficiency for the exhaust generated by natural gas cooking burners. Capture efficiency is defined as the fraction of generated pollutants that are removed through the exhaust and thus not available for inhalation of household occupants. Capture efficiency was assessed for various configurations of burner use (e.g., single front, single back, combination of one front and one back, oven) and fan speed setting. Measured airflow rates were substantially lower than the levels noted in product literature for many of the units. This shortfall was observed for several units costing more than $1000. Capture efficiency varied widely (from < 5 percent to roughly 100 percent) across devices and across conditions for some devices. As expected, higher capture efficiencies were achieved with higher fan settings and the associated higher air flow rates. In most cases, capture efficiencies were substantially higher for rear burners than for front burners. The best and most consistent performance was observed for open hoods that covered all cooktop burners and operated at higher airflow rates. The lowest capture efficiencies were measured when a front burner was used with a rear backdraft system or with lowest fan setting for above-the-range systems that do not cover the front burners.

437

Observations and Modeling of the August 27, 2012 Earthquake and Tsunami affecting El Salvador and Nicaragua  

E-Print Network [OSTI]

Observations and Modeling of the August 27, 2012 Earthquake and Tsunami affecting El Salvador Mw = 7.3 earthquake occurred off the coast of El Salvador and generated surprisingly large local Salvador and northern Nicara- gua. The tsunami reached a maximum height of *6 m with inundation of up

Lynett, Patrick

438

Current HMS Observations - Hanford Site  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Station Real Time Met Data from Around the Site Current HMS Observations Daily HMS Extremes in Met Data Met and Climate Data Summary Products Contacts Hours Current NWS...

439

Performance analysis of PV system for maximum utilization of solar radiation  

Science Journals Connector (OSTI)

A detailed analysis of a photovolatic (PV) stand-alone system using a novel battery voltage regulator to maximize the utilization of solar radiation is presented. The basic idea of the novel battery voltage regulator is discussed in a previously published work. The proposed system disconnects the battery rather than the PV array when the battery is fully charged. When the battery is disconnected, the load is supplied through a chopper. Hence, instead of losing available solar energy-by disconnecting the array-the energy is supplied to the load. The analysis presented here shows that the PV array may be disconnected for a variable period, ranging between 4 and 5 h per day during the summer season. This result indicates that a significant energy loss, up to 50% of the available solar energy, may occur during the summer. An elaborate analysis for the chopper circuit is given in this work. The analysis showed that the chopper keeps the load voltage almost constant if the chopper parameters are carefully designed. The novel system preserves the battery charge during periods of high solar insolation, thus the battery state of charge is kept high for long periods during the year. Consequently, the battery lifetime is prolonged. In this work, the climatic conditions of Cairo, the Egyptian capital, are considered. The effects of cloudy days on the system performance were taken into consideration.

Wagdy R. Anis; M.Abdul-Sadek Nour

1994-01-01T23:59:59.000Z

440

Some observations on time-hardening and strain-hardening rules for creep in Zircaloy-2  

SciTech Connect (OSTI)

The role of accurate creep prediction in zirconium alloys, and the Zircaloys in particular, has become increasingly important in light water reactor core component design and behavior analyses. A study was made of the applicability of time-hardening and strain-hardening rules to describe creep deformation in Zircaloy-2 under variable stress and temperature conditions. Variable stress and variable temperature creep data were compared to isotonic (iso-stress) and isothermal data in the stress regime 69 to 172 MPa and the temperature regime 325 to 400/degree/C. It was observed that creep deformation under these variable conditions does not follow a time-hardening rule. This paper formulates strain-hardening rule, which describes well the variable temperature creep deformation at temperatures up to 375/degree/C. At 400/degree/C, however, the strain-hardening rule broke down because of a nonnegligible recovery rate. 28 refs.

Lucas, G.E.; Pelloux, R.M.N.

1981-04-01T23:59:59.000Z

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While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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441

Dosimetric comparison of treatment plans based on free breathing, maximum, and average intensity projection CTs for lung cancer SBRT  

SciTech Connect (OSTI)

Purpose: To determine whether there is a CT dataset may be more favorable for planning and dose calculation by comparing dosimetric characteristics between treatment plans calculated using free breathing (FB), maximum and average intensity projection (MIP and AIP, respectively) CTs for lung cancer patients receiving stereotactic body radiation therapy (SBRT). Methods: Twenty lung cancer SBRT patients, treated on a linac with 2.5 mm width multileaf-collimator (MLC), were analyzed retrospectively. Both FB helical and four-dimensional CT scans were acquired for each patient. Internal target volume (ITV) was delineated based on MIP CTs and modified based on both ten-phase datasets and FB CTs. Planning target volume (PTV) was then determined by adding additional setup margin to ITV. The PTVs and beams in the optimized treatment plan based on FB CTs were copied to MIP and AIP CTs, with the same isocenters, MLC patterns and monitor units. Mean effective depth (MED) of beams, and some dosimetric parameters for both PTVs and most important organ at risk (OAR), lung minus PTV, were compared between any two datasets using two-tail paired t test. Results: The MEDs in FB and AIP plans were similar but significantly smaller (Ps < 0.001) than that in MIP plans. Minimum dose, mean dose, dose covering at least 90% and 95% of PTVs in MIP plans were slightly higher than two other plans (Ps < 0.008). The absolute volume of lung minus PTV receiving greater than 5, 10, and 20 Gy in MIP plans were significantly smaller than those in both FB and AIP plans (Ps < 0.008). Conformity index for FB plans showed a small but statistically significantly higher. Conclusions: Dosimetric characteristics of AIP plans are similar to those of FB plans. Slightly better target volume coverage and significantly lower low-dose region ({<=}30 Gy) in lung was observed in MIP plans. The decrease in low-dose region in lung was mainly caused by the change of lung volume contoured on two datasets rather than the differences of dose distribution between AIP and MIP plans. Compare with AIP datasets, FB datasets were more prone to significant image artifacts and MIP datasets may overestimate or underestimate the target volume when the target is closer to the denser tissue, so AIP seems favorable for planning and dose calculation for lung SBRT.

Tian Yuan; Wang Zhiheng; Ge Hong; Zhang Tian; Cai Jing; Kelsey, Christopher; Yoo, David; Yin Fangfang [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States) and Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Science, Beijing 100021 (China); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 and Department of Radiation Oncology, Henan Cancer Hospital, Zhengzhou, Henan 450008 (China); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

2012-05-15T23:59:59.000Z

442

Dynamical Simulations of North Atlantic Tropical Cyclone Activity Using Observed Low-Frequency SST Oscillation Imposed on CMIP5 Model RCP4.5 SST Projections  

Science Journals Connector (OSTI)

The effects on early and late twenty-first-century North Atlantic tropical cyclone statistics resulting from imposing the patterns of maximum/minimum phases of the observed Atlantic multidecadal oscillation (AMO) onto projected sea surface ...

Timothy E. LaRow; Lydia Stefanova; Chana Seitz

2014-11-01T23:59:59.000Z

443

Factor Analysis for Skewed Data and Skew-Normal Maximum Likelihood Factor Analysis  

E-Print Network [OSTI]

. RESULTS OF LARGE SAMPLE SIMULATIONS OF THE SKEW-ELLIPTICAL FACTOR MODEL WITH SMALLISH KURTOSIS ? = 5 AND P = 5 DIMENSIONS AND K = 2 COMMON FACTORS 258 vii LIST OF FIGURES FIGURE Page 1.1 Skewed Observed Data... . . . . . . . . . . 85 5.4 Standardized Factor Loadings and Uniquenesses in Simulation . 86 5.5 90% Probability Interval for ??MOM . . . . . . . . . . . . . . . . 109 5.6 95% Probability Interval for ??MOM . . . . . . . . . . . . . . . . 110 5.7 Proportion of Samples...

Gaucher, Beverly Jane

2013-04-04T23:59:59.000Z

444

Evaluation of a photovoltaic energy mechatronics system with a built-in quadratic maximum power point tracking algorithm  

SciTech Connect (OSTI)

The historically high cost of crude oil price is stimulating research into solar (green) energy as an alternative energy source. In general, applications with large solar energy output require a maximum power point tracking (MPPT) algorithm to optimize the power generated by the photovoltaic effect. This work aims to provide a stand-alone solution for solar energy applications by integrating a DC/DC buck converter to a newly developed quadratic MPPT algorithm along with its appropriate software and hardware. The quadratic MPPT method utilizes three previously used duty cycles with their corresponding power outputs. It approaches the maximum value by using a second order polynomial formula, which converges faster than the existing MPPT algorithm. The hardware implementation takes advantage of the real-time controller system from National Instruments, USA. Experimental results have shown that the proposed solar mechatronics system can correctly and effectively track the maximum power point without any difficulties. (author)

Chao, R.M.; Ko, S.H.; Lin, I.H. [Department of Systems and Naval Mechatronics Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China); Pai, F.S. [Department of Electronic Engineering, National University of Tainan (China); Chang, C.C. [Department of Environment and Energy, National University of Tainan (China)

2009-12-15T23:59:59.000Z

445

Investigating Broadband Variability of the TeV Blazar 1ES 1959+650  

E-Print Network [OSTI]

We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift UVOT, X-ray observations by the Swift X-ray Telescope (XRT), high-energy gamma-ray observations with the Fermi Large Area Telescope (LAT) and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 17 April 2012 and 1 June 2012 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected-emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected b...

Aliu, E; Arlen, T; Aune, T; Barnacka, A; Beilicke, M; Benbow, W; Berger, K; Bird, R; Bouvier, A; Buckley, J H; Bugaev, V; Cerruti, M; Chen, X; Ciupik, L; Collins-Hughes, E; Connolly, M P; Cui, W; Dumm, J; Eisch, J D; Falcone, A; Federici, S; Feng, Q; Finley, J P; Fleischhack, H; Fortin, P; Fortson, L; Furniss, A; Galante, N; Gillanders, G H; Griffin, S; Griffiths, S T; Grube, J; Gyuk, G; Hakansson, N; Hanna, D; Holder, J; Hughes, G; Humensky, T B; Johnson, C A; Kaaret, P; Kar, P; Kertzman, M; Khassen, Y; Kieda, D; Krawczynski, H; Krennrich, F; Lang, M J; Madhavan, A S; Majumdar, P; McArthur, S; McCann, A; Meagher, K; Millis, J; Moriarty, P; Mukherjee, R; Nelson, T; Nieto, D; de Bhroithe, A O'Faolain; Ong, R A; Otte, A N; Park, N; Perkins, J S; Pohl, M; Popkow, A; Prokoph, H; Quinn, J; Ragan, K; Rajotte, J; Reyes, L C; Reynolds, P T; Richards, G T; Roache, E; Sadun, A; Santander, M; Sembroski, G H; Shahinyan, K; Sheidaei, F; Smith, A W; Staszak, D; Telezhinsky, I; Theiling, M; Tyler, J; Varlotta, A; Vassiliev, V V; Vincent, S; Wakely, S P; Weekes, T C; Weinstein, A; Welsing, R; Wilhelm, A; Williams, D A; Zitzer, B; Böttcher, M; Fumagalli, M

2014-01-01T23:59:59.000Z

446

Empowering Variable Renewables: Options for Flexible Electricity Systems |  

Open Energy Info (EERE)

Empowering Variable Renewables: Options for Flexible Electricity Systems Empowering Variable Renewables: Options for Flexible Electricity Systems Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Empowering Variable Renewables: Options for Flexible Electricity Systems Agency/Company /Organization: International Energy Agency Sector: Energy Focus Area: Renewable Energy Topics: Market analysis, Technology characterizations Resource Type: Publications Website: www.iea.org/g8/2008/Empowering_Variable_Renewables.pdf Empowering Variable Renewables: Options for Flexible Electricity Systems Screenshot References: Empowering Variable Renewables: Options for Flexible Electricity Systems[1] Summary "Increasing the share of renewables in energy portfolios is a key tool in the drive to reduce anthropogenic carbon dioxide emissions, as well as

447

OVERVIEW OF SATURN LIGHTNING OBSERVATIONS  

E-Print Network [OSTI]

OVERVIEW OF SATURN LIGHTNING OBSERVATIONS G. Fischer* , U. A. Dyudina , W. S. Kurth , D. A. Gurnett The lightning activity in Saturn's atmosphere has been monitored by Cassini for more than six years favorably with imaging observa- tions of related cloud features as well as direct observations of flash

Gurnett, Donald A.

448

Eliminating the Renormalization Scale Ambiguity for Top-Pair Production Using the Principle of Maximum Conformality  

SciTech Connect (OSTI)

The uncertainty in setting the renormalization scale in finite-order perturbative QCD predictions using standard methods substantially reduces the precision of tests of the Standard Model in collider experiments. It is conventional to choose a typical momentum transfer of the process as the renormalization scale and take an arbitrary range to estimate the uncertainty in the QCD prediction. However, predictions using this procedure depend on the choice of renormalization scheme, leave a non-convergent renormalon perturbative series, and moreover, one obtains incorrect results when applied to QED processes. In contrast, if one fixes the renormalization scale using the Principle of Maximum Conformality (PMC), all non-conformal {l_brace}{beta}{sub i}{r_brace}-terms in the perturbative expansion series are summed into the running coupling, and one obtains a unique, scale-fixed, scheme-independent prediction at any finite order. The PMC renormalization scale {mu}{sub R}{sup PMC} and the resulting finite-order PMC prediction are both to high accuracy independent of choice of the initial renormalization scale {mu}{sub R}{sup init}, consistent with renormalization group invariance. Moreover, after PMC scale-setting, the n!-growth of the pQCD expansion is eliminated. Even the residual scale-dependence at fixed order due to unknown higher-order {l_brace}{beta}{sub i}{r_brace}-terms is substantially suppressed. As an application, we apply the PMC procedure to obtain NNLO predictions for the t{bar t}-pair hadroproduction cross-section at the Tevatron and LHC colliders. There are no renormalization scale or scheme uncertainties, thus greatly improving the precision of the QCD prediction. The PMC prediction for {sigma}{sub t{bar t}} is larger in magnitude in comparison with the conventional scale-setting method, and it agrees well with the present Tevatron and LHC data. We also verify that the initial scale-independence of the PMC prediction is satisfied to high accuracy at the NNLO level: the total cross-section remains almost unchanged even when taking very disparate initial scales {mu}{sub R}{sup init} equal to m{sub t}, 20 m{sub t}, {radical}s.

Brodsky, Stanley J.; /SLAC; Wu, Xing-Gang; /Chongqing U.

2012-04-02T23:59:59.000Z

449

Recent variability of the solar spectral irradiance and its impact on climate modelling  

E-Print Network [OSTI]

The lack of long and reliable time series of solar spectral irradiance (SSI) measurements makes an accurate quantification of solar contributions to recent climate change difficult. Whereas earlier SSI observations and models provided a qualitatively consistent picture of the SSI variability, recent measurements by the SORCE satellite suggest a significantly stronger variability in the ultraviolet (UV) spectral range and changes in the visible and near-infrared (NIR) bands in anti-phase with the solar cycle. A number of recent chemistry-climate model (CCM) simulations have shown that this might have significant implications on the Earth's atmosphere. Motivated by these results, we summarize here our current knowledge of SSI variability and its impact on Earth's climate. We present a detailed overview of existing SSI measurements and provide thorough comparison of models available to date. SSI changes influence the Earth's atmosphere, both directly, through changes in shortwave (SW) heating and therefore, temp...

Ermolli, I; de Wit, T Dudok; Krivova, N A; Tourpali, K; Weber, M; Unruh, Y C; Gray, L; Langematz, U; Pilewskie, P; Rozanov, E; Schmutz, W; Shapiro, A; Solanki, S K; Woods, T N

2013-01-01T23:59:59.000Z

450

Impact of variable RBE on proton fractionation  

SciTech Connect (OSTI)

Purpose: To explore the impact of variable proton relative biological effectiveness (RBE) on dose fractionation for clinically relevant situations. A generic RBE = 1.1 is generally used for isoeffect calculations, while experimental studies showed that proton RBE varies with tissue type, dose, and linear energy transfer (LET). Methods: An analytical expression for the LET and {alpha}/{beta} dependence of the linear-quadratic (LQ) model has been used for proton simulations in parallel with the assumption of a generic RBE = 1.1. Calculations have been performed for ranges of LET values and fractionation sensitivities to describe clinically relevant cases, such as the treatment of head and neck and prostate tumors. Isoeffect calculations were compared with predictions from a generic RBE value and reported clinical results. Results: The generic RBE = 1.1 appears to be a reasonable estimate for the proton RBE of rapidly growing tissues irradiated with low LET radiation. However, the use of a variable RBE predicts larger differences for tissues with low {alpha}/{beta} (both tumor and normal) and at low doses per fraction. In some situations these differences may appear in contrast to the findings from photon studies highlighting the importance of accurate accounting for the radiobiological effectiveness of protons. Furthermore, the use of variable RBE leads to closer predictions to clinical results. Conclusions: The LET dependence of the RBE has a strong impact on the predicted effectiveness of fractionated proton radiotherapy. The magnitude of the effect is modulated by the fractionation sensitivity and the fractional dose indicating the need for accurate analyses both in the target and around it. Care should therefore be employed for changing clinical fractionation patterns or when analyzing results from clinical studies for this type of radiation.

Dasu, Alexandru; Toma-Dasu, Iuliana [Department of Radiation Physics UHL, County Council of Oestergoetland, 581 85 Linkoeping (Sweden) and Radiation Physics, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping University, 581 83 Linkoeping (Sweden); Medical Radiation Physics, Stockholm University and Karolinska Institute, 171 76 Stockholm (Sweden)

2013-01-15T23:59:59.000Z

451

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

Lauf, Robert J. (Oak Ridge, TN); McMillan, April D. (Knoxville, TN); Paulauskas, Felix L. (Oak Ridge, TN); Fathi, Zakaryae (Cary, NC); Wei, Jianghua (Raleigh, NC)

1998-01-01T23:59:59.000Z

452

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

1998-09-08T23:59:59.000Z

453

Adhesive bonding using variable frequency microwave energy  

DOE Patents [OSTI]

Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy. 26 figs.

Lauf, R.J.; McMillan, A.D.; Paulauskas, F.L.; Fathi, Z.; Wei, J.

1998-08-25T23:59:59.000Z

454

Dynamical variables in Gauge-Translational Gravity  

E-Print Network [OSTI]

Assuming that the natural gauge group of gravity is given by the group of isometries of a given space, for a maximally symmetric space we derive a model in which gravity is essentially a gauge theory of translations. Starting from first principles we verify that a nonlinear realization of the symmetry provides the general structure of this gauge theory, leading to a simple choice of dynamical variables of the gravity field corresponding, at first order, to a diagonal matrix, whereas the non-diagonal elements contribute only to higher orders.

J. Julve; A. Tiemblo

2010-07-02T23:59:59.000Z

455

A variable parameter thermionic energy converter  

E-Print Network [OSTI]

A VARIABLE PARAMETER THERMIONIC ENERGY CONVERTER A Thesis By Bobby Joe Bragg Submitted to the Graduate School of the Texas A 8c M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August, 1967 Major... LIST OF FIGURES FIGURE 1. SIMPLE SCHEMATIC OF A THERMIONIC CONVERTER PAGE 2. POWER VS SPACING WITH A MINIMUM POWER POINT 3. POWER VS SPACING WITH NO MINIMUM POWER POINT 4. CONVERTER MOTIVE DIAGRAM~ O'E = 5. CONVERTER MOTIVE DIAGRAM~ 6. CONVERTER...

Bragg, Bobby Joe

1967-01-01T23:59:59.000Z

456

The future of massive variability searches  

E-Print Network [OSTI]

This is a personal review of various issues related to massive photometric and astrometric searches. A complete inventory of variable stars down to almost any magnitude limit will improve our understanding of the stellar evolution and the galactic structure. A search for detached eclipsing binaries will improve the distance scale, the value of the Hubble constant, and the age of the oldest stars. A search for supernovae will help the determination of cosmological parameters Omega and Lambda. A search for microlensing events will provide insight into the stellar mass function, dark matter, and may lead to a discovery of earth-mass planets.

Paczynski, B

1996-01-01T23:59:59.000Z

457

Crystal diffraction lens with variable focal length  

DOE Patents [OSTI]

A method and apparatus for altering the focal length of a focusing element of one of a plurality of pre-determined focal lengths by changing heat transfer within selected portions of the element by controlled quantities is disclosed. Control over heat transfer is accomplished by manipulating one or more of a number of variables, including: the amount of heat or cold applied to surfaces; type of fluids pumped through channels for heating and cooling; temperatures, directions of flow and rates of flow of fluids; and placement of channels. 19 figures.

Smither, R.K.

1991-04-02T23:59:59.000Z

458

Chi-Variable-Speed-of-Light Cosmologies  

E-Print Network [OSTI]

Variable-Speed-of-Light (VSL) cosmologies are currently attracting much interest as a possible alternative to cosmological inflation. We discuss the fundamental geometrodynamic aspects of VSL cosmologies, and provide several alternative implementations. These implementations provide a large class of VSL cosmologies that pass the zeroth-order consistency tests of being compatible with both classical Einstein gravity and low-energy particle physics. While they solve the ``kinematic'' puzzles as well as inflation does, VSL cosmologies typically do not solve the flatness problem since in their purest form no violation of the strong energy condition occurs. Nevertheless, these models are easy to unify with inflation.

Stefano Liberati; Bruce A. Bassett; Carmen Molina-Paris; Matt Visser

2000-01-27T23:59:59.000Z

459

Intraseasonal variability in South America recorded in stable water isotopes  

E-Print Network [OSTI]

Intraseasonal variability in South America recorded in stable water isotopes Christophe Sturm,1 cores (South America) has illustrated the key role such archives can play in past climate South America, highlighting the internal atmospheric variability, as opposed to external forcing

Sturm, Christophe "Kristof"

460

Wave spectral energy variability in the northeast Peter D. Bromirski  

E-Print Network [OSTI]

Wave spectral energy variability in the northeast Pacific Peter D. Bromirski Integrative January 2005; published 8 March 2005. [1] The dominant characteristics of wave energy variability] s wave spectral energy components are considered separately. Empirical orthogonal function (EOF) analyses

Bromirski, Peter D.

Note: This page contains sample records for the topic "maximum variable observations" 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

Bayesian variable selection in clustering via dirichlet process mixture models  

E-Print Network [OSTI]

simultane- ously. I use Dirichlet process mixture models to define the cluster structure and to introduce in the model a latent binary vector to identify discriminating variables. I update the variable selection index using a Metropolis algorithm and obtain...

Kim, Sinae

2007-09-17T23:59:59.000Z

462

Atlantic Climate Variability and Predictability: A CLIVAR Perspective  

Science Journals Connector (OSTI)

Three interrelated climate phenomena are at the center of the Climate Variability and Predictability (CLIVAR) Atlantic research: tropical Atlantic variability (TAV), the North Atlantic Oscillation (NAO), and the Atlantic meridional overturning ...

J. W. Hurrell; M. Visbeck; A. Busalacchi; R. A. Clarke; T. L. Delworth; R. R. Dickson; W. E. Johns; K. P. Koltermann; Y. Kushnir; D. Marshall; C. Mauritzen; M. S. McCartney; A. Piola; C. Reason; G. Reverdin; F. Schott; R. Sutton; I. Wainer; D. Wright

2006-10-01T23:59:59.000Z

463

The Deep Lens Survey Transient Search I : Short Timescale and Astrometric Variability  

E-Print Network [OSTI]

We report on the methodology and first results from the Deep Lens Survey transient search. We utilize image subtraction on survey data to yield all sources of optical variability down to 24th magnitude. Images are analyzed immediately after acquisition, at the telescope and in near-real time, to allow for followup in the case of time-critical events. All classes of transients are posted to the web upon detection. Our observing strategy allows sensitivity to variability over several decades in timescale. The DLS is the first survey to classify and report all types of photometric and astrometric variability detected, including solar system objects, variable stars, supernovae, and short timescale phenomena. Three unusual optical transient events were detected, flaring on thousand-second timescales. All three events were seen in the B passband, suggesting blue color indices for the phenomena. One event (OT 20020115) is determined to be from a flaring Galactic dwarf star of spectral type dM4. From the remaining two events, we find an overall rate of \\eta = 1.4 events deg-2 day-1 on thousand-second timescales, with a 95% confidence limit of \\eta < 4.3. One of these events (OT 20010326) originated from a compact precursor in the field of galaxy cluster Abell 1836, and its nature is uncertain. For the second (OT 20030305) we find strong evidence for an extended extragalactic host. A dearth of such events in the R passband yields an upper 95% confidence limit on short timescale astronomical variability between 19.5 < R < 23.4 of \\eta_R < 5.2. We report also on our ensemble of astrometrically variable objects, as well as an example of photometric variability with an undetected precursor.

A. C. Becker; D. M. Wittman; P. C. Boeshaar; A. Clocchiatti; I. P. Dell'Antonio; D. A. Frail; J. Halpern; V. E. Margoniner; D. Norman; J. A. Tyson; R. A. Schommer

2004-04-21T23:59:59.000Z

464

Improved maximum cooling by optimizing the geometry of thermoelectric leg elements Yan Zhang, Zhixi Bian and Ali Shakouri*  

E-Print Network [OSTI]

in improving the thermoelectric efficiency and maximum cooling mainly focuses on improving materials' figure , power factor; , thermal conductivity. Bi2Te3 has been the most popular thermoelectric material at room a high power factor. Most of the recent research on thermoelectrics focuses on improving the material

465

Maximum-Intensity Volumes for Fast Contouring of Lung Tumors Including Respiratory Motion in 4DCT Planning  

SciTech Connect (OSTI)

Purpose: To assess the accuracy of maximum-intensity volumes (MIV) for fast contouring of lung tumors including respiratory motion. Methods and Materials: Four-dimensional computed tomography (4DCT) data of 10 patients were acquired. Maximum-intensity volumes were constructed by assigning the maximum Hounsfield unit in all CT volumes per geometric voxel to a new, synthetic volume. Gross tumor volumes (GTVs) were contoured on all CT volumes, and their union was constructed. The GTV with all its respiratory motion was contoured on the MIV as well. Union GTVs and GTVs including motion were compared visually. Furthermore, planning target volumes (PTVs) were constructed for the union of GTVs and the GTV on MIV. These PTVs were compared by centroid position, volume, geometric extent, and surface distance. Results: Visual comparison of GTVs demonstrated failure of the MIV technique for 5 of 10 patients. For adequate GTV{sub MIV}s, differences between PTVs were <1.0 mm in centroid position, 5% in volume, {+-}5 mm in geometric extent, and {+-}0.5 {+-} 2.0 mm in surface distance. These values represent the uncertainties for successful MIV contouring. Conclusion: Maximum-intensity volumes are a good first estimate for target volume definition including respiratory motion. However, it seems mandatory to validate each individual MIV by overlaying it on a movie loop displaying the 4DCT data and editing it for possible inadequate coverage of GTVs on additional 4DCT motion states.

Rietzel, Eike [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Abteilung Biophysik, Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)], E-mail: eike@rietzel.net; Liu, Arthur K.; Chen, George T.Y.; Choi, Noah C. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)

2008-07-15T23:59:59.000Z

466

Periodic Flux Variability of Stars due to the Reflex Doppler Effect Induced by Planetary Companions  

E-Print Network [OSTI]

Upcoming space-based photometric satellites offer the possibility of detecting continuum flux variability at the micro-magnitude level. We show that the Doppler flux variability induced by the reflex motion of stars due to planetary companions has an amplitude of (3-alpha)K/c, where K is the reflex radial velocity amplitude and alpha is the logarithmic slope of source spectral flux in the observed frequency band. For many of the known close-in planetary systems with periods less than ~0.2 years, the periodic Doppler variability is of order a micromagnitude, and is significant relative to the variability caused by reflected light from the planetary companion. For companions with periods greater than ~0.2 years, the Doppler signal is larger than the reflected light signal. We show that the future photometric satellites should reach the sensitivity to detect this Doppler variability. In particular, the Kepler satellite should have the photon-noise sensitivity to detect at a signal-to-noise ratio > 5, all planets with minimum mass greater than 5 Jupiter masses, and periods less than 0.1 years around the 10,000 main-sequence stars with spectral types A through K and apparent magnitude V<12 in its field-of-view.

Abraham Loeb; B. Scott Gaudi

2003-03-10T23:59:59.000Z

467

Baryon Resonances Observed at BES  

E-Print Network [OSTI]

The $\\psi$ decays provide a novel way to explore baryon spectroscopy and baryon structure. The baryon resonances observed from $\\psi$ decays at BES are reviewed. The implications and prospects at upgraded BESIII/BEPCII are discussed.

B. S. Zou

2008-02-01T23:59:59.000Z

468

Improving and Observing Lithiation Reactions  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to observe these reactions in real-time as these reactions proceed. Enabling Silicon Carbide to Host Lithium In one set of measurements, they have discovered that the lithiation...

469

Variably insulating portable heater/cooler  

DOE Patents [OSTI]

A compact vacuum insulation panel comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning "on" and "off" the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls.

Potter, Thomas F. (Denver, CO)

1998-01-01T23:59:59.000Z

470

Variably insulating portable heater/cooler  

DOE Patents [OSTI]

A compact vacuum insulation panel is described comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning ``on`` and ``off`` the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls. 25 figs.

Potter, T.F.

1998-09-29T23:59:59.000Z

471

Variable Speed of Light Research Project Dave Schumann  

E-Print Network [OSTI]

Variable Speed of Light Research Project Dave Schumann Dr. Bharath Narayanan 21 September 2003 mathematics of the Variable Speed of Light (VSL) theory. In a paper titled, "A Time Varying Speed of Light of a variable speed of light in the early stages of the universe. They propose corrections to the cosmological

Zakharov, Vladimir

472

Energetic particle production, cavition formation, and nonlinear development at a plasma density maximum  

SciTech Connect (OSTI)

We have investigated several phenomena of importance to laser-plasma interactions. In our studies, these are modeled by microwave and rf-plasma interactions. Our focus has been on resonant absorption of intense electromagnetic radiation at the plasma critical layer. Electron plasma wave (EPW) growth and caviton formation have been shown to be most efficient for shallow density gradients at the critical layer, where EPW convection losses are minimized. EPW electric field energies of 5000 times the plasma thermal energy, and energetic electron tails out to 5000T{sub e}, have been observed at the top of an inverse parabolic density profile. Ions receive delta-function-like impulses from localized electron plasma waves and wave-breaking electron ejection; the disruption of the ion fluid can only partially be described by the ponderomotive force. Our attempt is to test and illuminate some of the fundamental concepts of strong turbulence and EM wave-plasma interaction. 7 refs.

Wong, A.Y.; Bauer, B.S. (California Univ., Los Angeles, CA (USA). Dept. of Physics)

1990-09-04T23:59:59.000Z

473

The modified dynamics (MOND) predicts an absolute maximum to the acceleration produced by `dark halos'  

E-Print Network [OSTI]

We have recently discovered that the modified dynamics (MOND) implies some universal upper bound on the acceleration that can be contributed by a `dark halo'--assumed in a Newtonian analysis to account for the effects of MOND. Not surprisingly, the limit is of the order of the acceleration constant of the theory. This can be contrasted directly with the results of structure-formation simulations. The new limit is substantial and different from earlier MOND acceleration limits (discussed in connection with the MOND explanation of the Freeman law for galaxy disks, and the Fish law for ellipticals): It pertains to the `halo', and not to the observed galaxy; it is absolute, and independent of further physical assumptions on the nature of the galactic system; and it applies at all radii, whereas the other limits apply only to the mean acceleration in the system.

Rafael Brada; Mordehai Milgrom

1998-12-21T23:59:59.000Z

474

HIGHLY VARIABLE EXTINCTION AND ACCRETION IN THE JET-DRIVING CLASS I-TYPE YOUNG STAR PTF 10nvg (V2492 Cyg, IRAS 20496+4354)  

SciTech Connect (OSTI)

We report extensive new photometry and spectroscopy of the highly variable young stellar object PTF 10nvg (also known as IRAS 20496+4354 and V2492 Cyg), including optical and near-infrared time-series data as well as mid-infrared and millimeter data. Following the previously reported 2010 rise to R{sub PTF} {approx}<13.{sup m}5 and subsequent fade, during 2011 and 2012 the source underwent additional episodes of brightening, followed by several magnitude dimming events including prolonged faint states at R{sub PTF} {approx}> 20{sup m}. The observed high-amplitude variations are largely consistent with extinction changes ({Delta}A{sub V} up to 30 mag) having a {approx}220 day quasi-periodic signal. However, photometry measured when the source was near maximum brightness in mid-2010 as well as in late-2012 does not phase well to this period. Spectral evolution includes not only changes in the spectral slope but also correlated variation in the prominence of TiO/VO/CO bands and atomic line emission, as well as anti-correlated variation in forbidden line emission which, along with H{sub 2}, dominates optical and infrared spectra at faint epochs. Notably, night-to-night variations in several forbidden doublet strengths and ratios are observed. High-dispersion spectra were obtained in a variety of photometric states and reveal time-variable line profiles. Neutral and singly ionized atomic species are likely formed in an accretion flow and/or impact while the origin of zero-velocity atomic Li I {lambda}6707 in emission is unknown. Forbidden lines, including several rare species, exhibit blueshifted emission profiles and likely arise from an outflow/jet. Several of these lines are also seen spatially offset from the continuum source position, presumably in a shocked region of an extended jet. Blueshifted absorption components of the Na I D doublet, K I {lambda}{lambda}7665, 7669 doublet, and the O I 7774 triplet, as well as blueshifted absorption components seen against the broad H{alpha} and Ca II triplet emission lines, similarly are formed in the outflow. CARMA maps resolve on larger scales a spatially extended outflow in millimeter-wavelength CO. We attribute the recently observed photometric and spectroscopic behavior to rotating circumstellar disk material located at separation a Almost-Equal-To 0.7(M{sub *}/M{sub Sun }){sup 1/3} AU from the continuum source, causing the semi-periodic dimming. Occultation of the central star as well as the bright inner disk and the accretion/outflow zones renders shocked gas in the inner part of the jet amenable to observation at the faint epochs. We discuss PTF 10nvg as a source exhibiting both accretion-driven (perhaps analogous to V1647 Ori) and extinction-driven (perhaps analogous to UX Ori or GM Cep) high-amplitude variability phenomena.

Hillenbrand, Lynne A.; Carpenter, John M.; Muirhead, Philip S.; Crepp, Justin R. [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Miller, Adam A.; Cenko, S. Bradley; Silverman, Jeffrey M.; Bloom, Joshua S.; Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Covey, Kevin R. [Department of Astronomy, Cornell University, 226 Space Sciences Building, Ithaca, NY 14853 (United States); Fischer, William J. [Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States)

2013-03-15T23:59:59.000Z

475

Variable firing rate power burner for high efficiency gas furnaces. Final report  

SciTech Connect (OSTI)

One method for increasing the efficiency of residential furnaces and boilers is to retrofit a burner capable of firing rate (FR) modulation. While maximum FR is still attainable, the average FR is significantly lower, resulting in more effective heat exchanger performance. Equally important is the capability for continuous firing at a very low rate (simmering) which eliminates off-cycle loss, a heavy contributor to inefficiency. Additional performance can be gained by reducing the excess air required by a burner. Based on its previous experience, Foster-Miller Associates, Inc. has designed and tested a low excess air (about 15%) variable firing rate (VFR) burner. The theory of operation and the construction of the test burner are described. Test results are given along with a conclusion/recommendation. A Phase II plan is outlined which suggests methods and steps for fabrication and field testing of a number of prototype units.

Fuller, H.H.; Demler, R.L.; Poulin, E.

1980-02-01T23:59:59.000Z

476

X-ray Variability and Emission Process of the Radio Jet in M87  

E-Print Network [OSTI]

We monitored the M87 jet with the ACIS-S detector on Chandra with 5 observations between 2002 Jan and 2002 Jul. Our goal was to determine the presence and degree of variability in morphology, intensity, and spectral parameters. We find strong variability of the core and HST-1, the knot lying 0.8" from the core. These observations were designed to constrain the X-ray emission process: whereas synchrotron emission would necessitate the presence of extremely high energy electrons with a halflife of a few years or less, inverse Compton emission from a relativistic jet would arise from low energy electrons with very long halflives. Currently, all indications point to a synchrotron process for the X-ray emission from the M87 jet. We give key parameters for a ``modest beaming'' synchrotron model.

D. E. Harris

2003-02-14T23:59:59.000Z

477

Stellar variability on time-scales of minutes: results from the first 5 years of the Rapid Temporal Survey (RATS)  

E-Print Network [OSTI]

The Rapid Temporal Survey (RATS) explores the faint, variable sky. Our observations search a parameter space which, until now, has never been exploited from the ground. Our strategy involves observing the sky close to the Galactic plane with wide-field CCD cameras. An exposure is obtained approximately every minute with the total observation of each field lasting around 2 hours. In this paper we present the first 6 epochs of observations which were taken over 5 years from 2003--2008 and cover over 31 square degrees of which 16.2 is within 10{\\deg} of the Galactic plane. The number of stars contained in these data is over 3.0 x10^6. We have developed a method of combining the output of two variability tests in order to detect variability on time-scales ranging from a few minutes to a few hours. Using this technique we find 1.2 x 10^5 variables -- equal to 4.1 per cent of stars in our data. Follow-up spectroscopic observations have allowed us to identify the nature of a fraction of these sources. These include ...

Barclay, Thomas; Hakala, Pasi; Napiwotzki, Ralf; Nelemans, Gijs; Potter, Stephen; Todd, Ian

2011-01-01T23:59:59.000Z

478

Spectral radio observations of a solar eclipse  

Science Journals Connector (OSTI)

Measurements were made of the 7 March, 1970 solar eclipse by the AFCRL Sagamore Hill Radio Observatory in Hamilton, Massachusetts, on the wavelengths of 0.86,...m...=0.96) occurred at eclipse maximum. Source flux...

R. M. Straka

1971-12-01T23:59:59.000Z

479

Variable-field permanent magnet dipole  

SciTech Connect (OSTI)

A new concept for a variable-field permanent-magnet dipole (VFPMD) has been designed, fabricated, and tested at Los Alamos. The VFPMD is a C-shaped sector magnet with iron poles separated by a large block of magnet material (SmCo). The central field can be continuously varied from 0.07 T to 0.3 T by moving an iron shunt closer or further away from the back of the magnet. The shunt is specially shaped to make the dependence of the dipole field strength on the shunt position as linear as possible. The dipole has a 2.8 cm high by 8 cm wide aperture with {approximately}10 cm long poles.

Barlow, D.B.; Kraus, R.H. Jr.; Meyer, R.E.

1993-10-01T23:59:59.000Z

480

Dissecting magnetar variability with Bayesian hierarchical models  

E-Print Network [OSTI]

Neutron stars are a prime laboratory for testing physical processes under conditions of strong gravity, high density, and extreme magnetic fields. Among the zoo of neutron star phenomena, magnetars stand out for their bursting behaviour, ranging from extremely bright, rare giant flares to numerous, less energetic recurrent bursts. The exact trigger and emission mechanisms for these bursts are not known; favoured models involve either a crust fracture and subsequent energy release into the magnetosphere, or explosive reconnection of magnetic field lines. In the absence of a predictive model, understanding the physical processes responsible for magnetar burst variability is difficult. Here, we develop an empirical model that decomposes magnetar bursts into a superposition of small spike-like features with a simple functional form, where the number of model components is itself part of the inference problem. The cascades of spikes that we model might be formed by avalanches of reconnection, or crust rupture afte...

Huppenkothen, D; Hogg, D W; Murray, I; Frean, M; Elenbaas, C; Watts, A L; Levin, Y; van der Horst, A J; Kouveliotou, C

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "maximum variable observations" 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

Improvements of the Variable Thermal Resistance  

E-Print Network [OSTI]

A flat mounting unit with electronically variable thermal resistance [1] has been presented in the last year [2]. The design was based on a Peltier cell and the appropriate control electronics and software. The device is devoted especially to the thermal characterization of packages, e.g. in dual cold plate arrangements. Although this design meets the requirements of the static measurement we are intended to improve its parameters as the settling time and dynamic thermal impedance and the range of realized thermal resistance. The new design applies the heat flux sensor developed by our team as well [3], making easier the control of the device. This development allows even the realization of negative thermal resistances.

V. Szekely; S. Torok; E. Kollar

2008-01-07T23:59:59.000Z

482

Thermal management of batteries using a Variable-Conductance Insulation (VCI) enclosure  

SciTech Connect (OSTI)

Proper thermal management is important for optimum performance and durability of most electric-vehicle batteries. For high-temperature cells such as sodium/sulphur, a very efficient and responsive thermal control system is essential. Heat must be removed during exothermic periods and retained when the batteries are not in use. Current thermal management approaches rely on passive insulation enclosures with active cooling loops that penetrate the enclosure. This paper presents the design, analysis, and testing of an enclosure with variable conductance insulation (VCI). VCI uses a hydride with an integral electric resistance heater to expel and retrieve a small amount of hydrogen gas into a vacuum space. By controlling the amount of hydrogen gas, the thermal conductance can be varied by more than 100:1, enabling the cooling loop (cold plate) to be mounted on the enclosure exterior. By not penetrating the battery enclosure, the cooling system is simpler and more reliable. Also, heat can be retained more effectively when desired. For high temperatures, radiation shields within the vacuum space are required. Ceramic spacers are used to maintain separation of the steel enclosure materials against atmospheric loading. Ceramic-to-ceramic thermal contact resistance within the spacer assembly minimizes thermal conductance. Two full-scale (0.8-m {times} 0.9-m {times} 0.3-m) prototypes were designed, built, and tested under high-temperature 200{degrees}-350{degrees}C battery conditions. With an internal temperature of 330{degrees}C (and 20{degrees}C ambient), the measured total-enclosure minimum heat loss was 80 watts (excluding wire pass-through losses). The maximum heat rejection was 4100 watts. The insulation can be switched from minimum to maximum conductance (hydrogen pressure from 2.0 {times} 10{sup -3} to 8 torr) in 3 minutes. Switching from maximum to minimum conductance was longer (16 minutes), but still satisfactory because of the large thermal mass of the battery.

Burch, S.D.; Parish, R.C.; Keyser, M.A.

1995-05-01T23:59:59.000Z

483

Variable magnetic field geometry of the young sun HN Peg (HD 206860)  

E-Print Network [OSTI]

The large-scale magnetic field of solar-type stars reconstructed from their spectropolarimetric observations provide important insight into their underlying dynamo processes.We aim to investigate the temporal variability of the large-scale surface magnetic field and chromospheric activity of a young solar analogue, the G0 dwarf HN Peg.The large-scale surface magnetic field topology is reconstructed using Zeeman Doppler Imaging at six observational epochs covering seven years.We also investigated the chromospheric activity variations by measuring the flux in the line cores of the three chromospheric activity indicators: Ca II H&K, H alpha, and the Ca II IRT lines.The magnetic topology of HN Peg shows a complex and variable geometry. While the radial field exhibits a stable positive polarity magnetic region at the poles at each observational epoch, the azimuthal field is strongly variable in strength, where a strong band of positive polarity magnetic field is present at equatorial latitudes. This field disa...

Saikia, S Boro; Petit, P; Marsden, S; Morin, J; Folsom, C P

2014-01-01T23:59:59.000Z

484

Building Technologies Office: Advanced, Variable Speed Air-Source  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Advanced, Variable Advanced, Variable Speed Air-Source Integrated Heat Pumps Research Project to someone by E-mail Share Building Technologies Office: Advanced, Variable Speed Air-Source Integrated Heat Pumps Research Project on Facebook Tweet about Building Technologies Office: Advanced, Variable Speed Air-Source Integrated Heat Pumps Research Project on Twitter Bookmark Building Technologies Office: Advanced, Variable Speed Air-Source Integrated Heat Pumps Research Project on Google Bookmark Building Technologies Office: Advanced, Variable Speed Air-Source Integrated Heat Pumps Research Project on Delicious Rank Building Technologies Office: Advanced, Variable Speed Air-Source Integrated Heat Pumps Research Project on Digg Find More places to share Building Technologies Office: Advanced,

485

Contouring Variability of the Penile Bulb on CT Images: Quantitative Assessment Using a Generalized Concordance Index  

SciTech Connect (OSTI)

Purpose: Within a multicenter study (DUE-01) focused on the search of predictors of erectile dysfunction and urinary toxicity after radiotherapy for prostate cancer, a dummy run exercise on penile bulb (PB) contouring on computed tomography (CT) images was carried out. The aim of this study was to quantitatively assess interobserver contouring variability by the application of the generalized DICE index. Methods and Materials: Fifteen physicians from different Institutes drew the PB on CT images of 10 patients. The spread of DICE values was used to objectively select those observers who significantly disagreed with the others. The analyses were performed with a dedicated module in the VODCA software package. Results: DICE values were found to significantly change among observers and patients. The mean DICE value was 0.67, ranging between 0.43 and 0.80. The statistics of DICE coefficients identified 4 of 15 observers who systematically showed a value below the average (p value range, 0.013 - 0.059): Mean DICE values were 0.62 for the 4 'bad' observers compared to 0.69 of the 11 'good' observers. For all bad observers, the main cause of the disagreement was identified. Average DICE values were significantly worse from the average in 2 of 10 patients (0.60 vs. 0.70, p < 0.05) because of the limited visibility of the PB. Excluding the bad observers and the 'bad' patients,' the mean DICE value increased from 0.67 to 0.70; interobserver variability, expressed in terms of standard deviation of DICE spread, was also reduced. Conclusions: The obtained values of DICE around 0.7 shows an acceptable agreement, considered the small dimension of the PB. Additional strategies to improve this agreement are under consideration and include an additional tutorial of the so-called bad observers with a recontouring procedure, or the recontouring by a single observer of the PB for all patients included in the DUE-01 study.

Carillo, Viviana [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Cozzarini, Cesare [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy)] [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy); Perna, Lucia; Calandra, Mauro [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Gianolini, Stefano [Medical Software Solutions GmbH, Hagendorn (Switzerland)] [Medical Software Solutions GmbH, Hagendorn (Switzerland); Rancati, Tiziana [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy)] [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy); Spinelli, Antonello Enrico [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Vavassori, Vittorio [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Italy)] [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Ital