National Library of Energy BETA

Sample records for maximum variable observations

  1. Speech processing using conditional observable maximum likelihood continuity mapping

    DOE Patents [OSTI]

    Hogden, John; Nix, David

    2004-01-13

    A computer implemented method enables the recognition of speech and speech characteristics. Parameters are initialized of first probability density functions that map between the symbols in the vocabulary of one or more sequences of speech codes that represent speech sounds and a continuity map. Parameters are also initialized of second probability density functions that map between the elements in the vocabulary of one or more desired sequences of speech transcription symbols and the continuity map. The parameters of the probability density functions are then trained to maximize the probabilities of the desired sequences of speech-transcription symbols. A new sequence of speech codes is then input to the continuity map having the trained first and second probability function parameters. A smooth path is identified on the continuity map that has the maximum probability for the new sequence of speech codes. The probability of each speech transcription symbol for each input speech code can then be output.

  2. Amplitude Variability in gamma Dor and delta Sct Stars Observed...

    Office of Scientific and Technical Information (OSTI)

    Title: Amplitude Variability in gamma Dor and delta Sct Stars Observed by Kepler The NASA ... Research Org: Los Alamos National Laboratory (LANL) Sponsoring Org: NASA Country of ...

  3. OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT

    SciTech Connect (OSTI)

    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)

    2013-06-20

    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.

  4. Lack of uniform trends but increasing spatial variability in observed Indian rainfall extremes

    SciTech Connect (OSTI)

    Ghosh, Subimal [ORNL; Das, Debasish [ORNL; Kao, Shih-Chieh [ORNL; Ganguly, Auroop R [ORNL

    2012-01-01

    Recent studies disagree on how rainfall extremes over India have changed in space and time over the past half century, as well as on whether the changes observed are due to global warming or regional urbanization. Although a uniform and consistent decrease in moderate rainfall has been reported, a lack of agreement about trends in heavy rainfall may be due in part to differences in the characterization and spatial averaging of extremes. Here we use extreme value theory to examine trends in Indian rainfall over the past half century in the context of long-term, low-frequency variability.We show that when generalized extreme value theory is applied to annual maximum rainfall over India, no statistically significant spatially uniform trends are observed, in agreement with previous studies using different approaches. Furthermore, our space time regression analysis of the return levels points to increasing spatial variability of rainfall extremes over India. Our findings highlight the need for systematic examination of global versus regional drivers of trends in Indian rainfall extremes, and may help to inform flood hazard preparedness and water resource management in the region.

  5. Amplitude Variability in gamma Dor and delta Sct Stars Observed by Kepler

    SciTech Connect (OSTI)

    Guzik, Joyce Ann; Kosak, Mary Katherine; Bradley, Paul Andrew; Jackiewicz, Jason

    2015-08-17

    The NASA Kepler spacecraft data revealed a large number of new multimode nonradially pulsating gamma Dor and delta Sct variable stars. The Kepler high-precision long time-series photometry makes it possible to study amplitude variations of the frequencies, and recent literature on amplitude and frequency variations in nonradially pulsating variables is summarized. Several methods are applied to study amplitude variability in about a dozen gamma Doradus or delta Scuti candidate variable stars observed for several quarters as part of the Kepler Guest Observer program. The magnitude and timescale of the amplitude variations are discussed, along with the presence or absence of correlations between amplitude variations for different frequencies of a given star. Proposed causes of amplitude spectrum variability that will require further investigation are also discussed.

  6. Observations of regional and local variability in the optical properties of maritime clouds

    SciTech Connect (OSTI)

    White, A.B.

    1996-04-01

    White and Fairall (1995) calculated the optical properties of the marine boundary layer (MBL) clouds observed during the Atlantic Stratocumulus Transition Experiment (ASTEX) and compared their results with the results obtained by Fairall et al. for the MBL clouds observed during the First International Satellite Climatology Program (ISSCP) Regional Experiment (FIRE). They found a factor of two difference in the optical depth versus liquid water relationship that applies to the clouds observed in each case. In the present study, we present evidence to support this difference. We also investigate the local variability exhibited in the ASTEX optical properties using measurements of the boundary layer aerosol concentration.

  7. Pulsations and period changes of the non-Blazhko RR lyrae variable Y oct observed from Dome A, Antarctica

    SciTech Connect (OSTI)

    Zhihua, Huang; Jianning, Fu; Weikai, Zong; Lingzhi, Wang; Zonghong, Zhu; M, Macri Lucas; Lifan, Wang; Ashley, Michael C. B.; S, Lawrence Jon; Daniel, Luong-Van; Xiangqun, Cui; Long-Long, Feng; Xuefei, Gong; Qiang, Liu; Huigen, Yang; Xiangyan, Yuan; Xu, Zhou; Zhenxi, Zhu; R, Pennypacker Carl; G, York Donald

    2015-01-01

    During the operation of the Chinese Small Telescope Array (CSTAR) in Dome A of Antarctica in the years 2008, 2009, and 2010, large amounts of photometric data have been obtained for variable stars in the CSTAR field. We present here the study of one of six RR Lyrae variables, Y Oct, observed with CSTAR in Dome A, Antarctica. Photometric data in the i band were obtained in 2008 and 2010, with a duty cycle (defined as the fraction of time representing scientifically available data to CSTAR observation time) of about 44% and 52%, respectively. In 2009, photometric data in the g and r bands were gathered for this star, with a duty cycle of 65% and 60%, respectively. Fourier analysis of the data in the three bands only shows the fundamental frequency and its harmonics, which is characteristic of the non-Blazhko RR Lyrae variables. Values of the fundamental frequency and the amplitudes, as well as the total pulsation amplitude, are obtained from the data in the three bands separately. The amplitude of the fundamental frequency and the total pulsation amplitude in the g band are the largest, and those in the i band the smallest. Two-hundred fifty-one times of maximum are obtained from the three seasons of data, which are analyzed together with 38 maximum times provided in the GEOS RR Lyrae database. A period change rate of −0.96 ± 0.07 days Myr{sup −1} is then obtained, which is a surprisingly large negative value. Based on relations available in the literature, the following physical parameters are derived: [Fe/H] = −1.41 ± 0.14, M{sub V} = 0.696 ± 0.014 mag, V−K = 1.182 ± 0.028 mag, logT{sub eff} = 3.802 ± 0.003 K, logg = 2.705 ± 0.004, logL/L{sub ⊙} = 1.625 ± 0.013, and logM/M{sub ⊙} = −0.240 ± 0.019.

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

    SciTech Connect (OSTI)

    Wang, Lingzhi; Zhu, Zonghong; Macri, Lucas M.; Wang, Lifan; Ashley, Michael C. B.; Lawrence, Jon S.; Luong-Van, Daniel; Storey, John W. V.; Cui, Xiangqun; Feng, Long-Long; Gong, Xuefei; Liu, Qiang; Shang, Zhaohui; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhou, Xu; Zhu, Zhenxi; Pennypacker, Carl R.; York, Donald G.

    2013-12-01

    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.

  9. Observed 20th Century Desert Dust Variability: Impact on Climate and Biogeochemistry

    SciTech Connect (OSTI)

    Mahowald, Natalie; Kloster, Silvia; Engelstaedter, S.; Moore, Jefferson Keith; Mukhopadhyay, S.; McConnell, J. R.; Albani, S.; Doney, Scott C.; Bhattacharya, A.; Curran, M. A. J.; Flanner, Mark G.; Hoffman, Forrest M; Lawrence, David M.; Lindsay, Keith; Mayewski, P. A.; Neff, Jason; Rothenberg, D.; Thomas, E.; Thornton, Peter E; Zender, Charlie S.

    2010-01-01

    Desert dust perturbs climate by directly and indirectly interacting with incoming solar and outgoing long wave radiation, thereby changing precipitation and temperature, in addition to modifying ocean and land biogeochemistry. While we know that desert dust is sensitive to perturbations in climate and human land use, previous studies have been unable to determine whether humans were increasing or decreasing desert dust in the global average. Here we present observational estimates of desert dust based on paleodata proxies showing a doubling of desert dust during the 20th century over much, but not all the globe. Large uncertainties remain in estimates of desert dust variability over 20th century due to limited data. Using these observational estimates of desert dust change in combination with ocean, atmosphere and land models, we calculate the net radiative effect of these observed changes (top of atmosphere) over the 20th century to be -0.14 {+-} 0.11 W/m{sup 2} (1990-1999 vs. 1905-1914). The estimated radiative change due to dust is especially strong between the heavily loaded 1980-1989 and the less heavily loaded 1955-1964 time periods (-0.57 {+-} 0.46 W/m{sup 2}), which model simulations suggest may have reduced the rate of temperature increase between these time periods by 0.11 C. Model simulations also indicate strong regional shifts in precipitation and temperature from desert dust changes, causing 6 ppm (12 PgC) reduction in model carbon uptake by the terrestrial biosphere over the 20th century. Desert dust carries iron, an important micronutrient for ocean biogeochemistry that can modulate ocean carbon storage; here we show that dust deposition trends increase ocean productivity by an estimated 6% over the 20th century, drawing down an additional 4 ppm (8 PgC) of carbon dioxide into the oceans. Thus, perturbations to desert dust over the 20th century inferred from observations are potentially important for climate and biogeochemistry, and our understanding

  10. Observation

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

    Velocity-Independent Electron Transport in the Reversed Field Pinch R. O'Connell, * D. J. Den Hartog, C. B. Forest, J. K. Anderson, T. M. Biewer, † B. E. Chapman, D. Craig, G. Fiksel, S. C. Prager, J. S. Sarff, and S. D. Terry ‡ Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA R.W. Harvey CompX, San Diego, California, USA (Received 16 December 2002; published 24 July 2003) Confinement of runaway electrons has been observed for the first time in a reversed

  11. Observations

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

    Observations 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. B. White, 4 and C. Xiao 3,5 1 Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti, 4 35127 Padova, Italy * 2 Istituto Nazionale di Fisica della Materia, UdR Padova, Italy 3 Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA 4

  12. Maximum-likelihood

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

    Jurisdiction waters of the Gulf of Mexico. Alaska is all onshore. Total crews includes crews with unknown survey dimension. Data are reported on the first and fifteenth of each month, except January when they are reported only on the fifteenth. When semi-monthly values differ for the month, the larger of the two values is shown here. Consequently, this table reflects the maximum number of crews at work at any time during the month. See Definitions, Sources, and Notes link above for more

  13. Simultaneous Observations of PKS 2155--304 with H.E.S.S., Fermi, RXTE and ATOM: Spectral Energy Distributions and Variability in a Low State

    SciTech Connect (OSTI)

    Aharonian, F.; Akhperjanian, A.G.; Anton, G.; Barres de Almeida, U.; Bazer-Bachi, A.R.; Becherini, Y.; Behera, B.; Bernlohr, K.; Boisson, C.; Bochow, A.; Borrel, V.; Brion, E.; Brucker, J.; Brun, P.; Buhler, R.; Bulik, T.; Busching, I.; Boutelier, T.; Chadwick, P.M.; Charbonnier, A.; Chaves, R.C.G.; /more authors..

    2009-05-07

    We report on the first simultaneous observations that cover the optical, X-ray, and high-energy gamma-ray bands of the BL Lac object PKS 2155-304. The gamma-ray bands were observed for 11 days, between 2008 August 25 and 2008 September 6 (MJD 54704-54715), jointly with the Fermi Gamma-ray Space Telescope and the HESS atmospheric Cherenkov array, providing the first simultaneous MeV-TeV spectral energy distribution (SED) with the new generation of {gamma}-ray telescopes. The ATOM telescope and the RXTE and Swift observatories provided optical and X-ray coverage of the low-energy component over the same time period. The object was close to the lowest archival X-ray and very high energy (VHE; >100 GeV) state, whereas the optical flux was much higher. The light curves show relatively little ({approx}30%) variability overall when compared to past flaring episodes, but we find a clear optical/VHE correlation and evidence for a correlation of the X-rays with the high-energy spectral index. Contrary to previous observations in the flaring state, we do not find any correlation between the X-ray and VHE components. Although synchrotron self-Compton models are often invoked to explain the SEDs of BL Lac objects, the most common versions of these models are at odds with the correlated variability we find in the various bands for PKS 2155-304.

  14. NON-RADIAL OSCILLATIONS IN M-GIANT SEMI-REGULAR VARIABLES: STELLAR MODELS AND KEPLER OBSERVATIONS

    SciTech Connect (OSTI)

    Stello, Dennis; Compton, Douglas L.; Bedding, Timothy R.; Kiss, Laszlo L.; Bellamy, Beau; Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans; García, Rafael A.

    2014-06-10

    The success of asteroseismology relies heavily on our ability to identify the frequency patterns of stellar oscillation modes. For stars like the Sun this is relatively easy because the mode frequencies follow a regular pattern described by a well-founded asymptotic relation. When a solar-like star evolves off the main sequence and onto the red giant branch its structure changes dramatically, resulting in changes in the frequency pattern of the modes. We follow the evolution of the adiabatic frequency pattern from the main sequence to near the tip of the red giant branch for a series of models. We find a significant departure from the asymptotic relation for the non-radial modes near the red giant branch tip, resulting in a triplet frequency pattern. To support our investigation we analyze almost four years of Kepler data of the most luminous stars in the field (late K and early M type) and find that their frequency spectra indeed show a triplet pattern dominated by dipole modes even for the most luminous stars in our sample. Our identification explains previous results from ground-based observations reporting fine structure in the Petersen diagram and sub-ridges in the period-luminosity diagram. Finally, we find ''new ridges'' of non-radial modes with frequencies below the fundamental mode in our model calculations, and we speculate they are related to f modes.

  15. Spitzer/IRAC observations of the variability of Sgr A* and the object G2 at 4.5 μm

    SciTech Connect (OSTI)

    Hora, J. L.; Ashby, M. L. N.; Fazio, G. G.; Smith, H. A.; Willner, S. P.; Witzel, G.; Becklin, E. E.; Ghez, A.; Meyer, L.; Morris, M. R.; Carey, S.; Ingalls, J.

    2014-10-01

    We present the first detection from the Spitzer Space Telescope of 4.5 μm variability from Sgr A*, the emitting source associated with the Milky Way's central black hole. The >23 hr continuous light curve was obtained with the Infrared Array Camera (IRAC) instrument in 2013 December. The result characterizes the variability of Sgr A* prior to the closest approach of the tidally deformed G2 object, a putative infalling gas cloud that orbits close to Sgr A*. The high stellar density at the location of Sgr A* produces a background of ∼250 mJy at 4.5 μm in each pixel with a large pixel-to-pixel gradient, but the light curve for the highly variable Sgr A* source was successfully measured by modeling and removing the variations due to pointing wobble. The observed flux densities range from the noise level of ∼0.7 mJy rms in a 6.4 s measurement to ≳10 mJy. Emission was seen above the noise level ∼34% of the time. The light-curve characteristics, including the flux density distribution and structure function, are consistent with those previously derived at shorter infrared wavelengths. We see no evidence in the light curve for activity attributable to the G2 interaction at the observing epoch, ∼100 days before the expected G2 periapsis passage. The IRAC light curve is more than a factor of two longer than any previous infrared observation, improving constraints on the timescale of the break in the power spectral distribution of Sgr A* flux densities. The data favor the longer of the two previously published values for the timescale.

  16. Removal to Maximum Extent Practical

    Broader source: Energy.gov [DOE]

    Summary Notes from 1 November 2007 Generic Technical Issue Discussion on Removal of Highly Radioactive Radionuclides/Key Radionuclides to the Maximum Extent Practical

  17. Analysis of Cyclic Variability of Heat Release for High-EGR GDI Engine Operation with Observations on Implications for Effective Control

    SciTech Connect (OSTI)

    Kaul, Brian C; Wagner, Robert M; Green Jr, Johney Boyd

    2013-01-01

    Operation of spark-ignition (SI) engines with high levels of charge dilution through exhaust gas recirculation (EGR) achieves significant engine efficiency gains while maintaining stoichiometric operation for compatibility with three-way catalysts. Dilution levels, however, are limited by cyclic variability-including significant numbers of misfires-that becomes more pronounced with increasing dilution. This variability has been shown to have both stochastic and deterministic components. Stochastic effects include turbulence, mixing variations, and the like, while the deterministic effect is primarily due to the nonlinear dependence of flame propagation rates and ignition characteristics on the charge composition, which is influenced by the composition of residual gases from prior cycles. The presence of determinism implies that an increased understanding the dynamics of such systems could lead to effective control approaches that allow operation near the edge of stability, effectively extending the dilution limit. This nonlinear dependence has been characterized previously for homogeneous charge, port fuel-injected (PFI) SI engines operating fuel-lean as well as with inert diluents such as bottled N2 gas. In this paper, cyclic dispersion in a modern boosted gasoline direct injection (GDI) engine using a cooled external EGR loop is examined, and the potential for improvement with effective control is evaluated through the use of symbol sequence statistics and other techniques from chaos theory. Observations related to the potential implications of these results for control approaches that could effectively enable engine operation at the edge of combustion stability are noted.

  18. SU-E-J-266: Cone Beam Computed Tomography (CBCT) Inter-Scan and Inter-Observer Tumor Volume Variability Assessment in Patients Treated with Stereotactic Body Radiation Therapy (SBRT) for Early Stage Non-Small Cell Lung Cancer (NSCLC)

    SciTech Connect (OSTI)

    Hou, Y; Aileen, C; Kozono, D; Killoran, J; Wagar, M; Lee, S; Hacker, F; Aerts, H; Lewis, J; Mak, R

    2015-06-15

    Purpose: Quantification of volume changes on CBCT during SBRT for NSCLC may provide a useful radiological marker for radiation response and adaptive treatment planning, but the reproducibility of CBCT volume delineation is a concern. This study is to quantify inter-scan/inter-observer variability in tumor volume delineation on CBCT. Methods: Twenty earlystage (stage I and II) NSCLC patients were included in this analysis. All patients were treated with SBRT with a median dose of 54 Gy in 3 to 5 fractions. Two physicians independently manually contoured the primary gross tumor volume on CBCTs taken immediately before SBRT treatment (Pre) and after the same SBRT treatment (Post). Absolute volume differences (AVD) were calculated between the Pre and Post CBCTs for a given treatment to quantify inter-scan variability, and then between the two observers for a given CBCT to quantify inter-observer variability. AVD was also normalized with respect to average volume to obtain relative volume differences (RVD). Bland-Altman approach was used to evaluate variability. All statistics were calculated with SAS version 9.4. Results: The 95% limit of agreement (mean ± 2SD) on AVD and RVD measurements between Pre and Post scans were −0.32cc to 0.32cc and −0.5% to 0.5% versus −1.9 cc to 1.8 cc and −15.9% to 15.3% for the two observers respectively. The 95% limit of agreement of AVD and RVD between the two observers were −3.3 cc to 2.3 cc and −42.4% to 28.2% respectively. The greatest variability in inter-scan RVD was observed with very small tumors (< 5 cc). Conclusion: Inter-scan variability in RVD is greatest with small tumors. Inter-observer variability was larger than inter-scan variability. The 95% limit of agreement for inter-observer and inter-scan variability (∼15–30%) helps define a threshold for clinically meaningful change in tumor volume to assess SBRT response, with larger thresholds needed for very small tumors. Part of the work was funded by a Kaye

  19. Maximum Performance Group MPG | Open Energy Information

    Open Energy Info (EERE)

    Maximum Performance Group MPG Jump to: navigation, search Name: Maximum Performance Group (MPG) Place: College Point, New York Zip: 11356 Product: Technology based energy and asset...

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

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

    Boiler Maximum Achievable Control Technology (MACT) Technical Assistance - Fact Sheet, April 2015 Boiler Maximum Achievable Control Technology (MACT) Technical Assistance - Fact ...

  1. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted...

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

    PRIME Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by ...

  2. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted...

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

    Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 5, 1, 2 SO2 Case Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts ...

  3. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted...

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

    Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 4, 1, 2 SO2 Case Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts ...

  4. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted...

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

    Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 3, 1, 2 SO2 Case Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts ...

  5. Maximum entanglement in squeezed boson and fermion states

    SciTech Connect (OSTI)

    Khanna, F. C.; Malbouisson, J. M. C.; Santana, A. E.; Santos, E. S.

    2007-08-15

    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.

  6. Variability and extremes of winter temperatures in Europe 1870-1980

    SciTech Connect (OSTI)

    Wallen, C.C.

    1986-01-01

    An attempt is made to study, by statistical treatment of surface observations, the fluctuations in variability of winter temperatures during the past century at eight selected European stations, four of them being considered as maritime and four continental in their location. Variability has been studied by three different parameters: interannual variability of winter months by consecutive decades from 1870-1980, intermonthly variability throughout the winters by consecutive decades from 1870-1980 and frequency of extreme values of monthly winter temperatures by consecutive decades from 1870-1980. Both interannual and intermonthly variability are shown to have been at a minimum during the decades of a strong climate maritimity in the beginning of this century (1900-1920) and at a maximum during the decades of transition (1930-1950) from the mild era in the first four decades of the century to a colder period. There is no clear indication that variability increased during the most recent decades although Moscow, the most eastern of the used stations, shows high variability in recent time. Extreme values seem to be increasing in frequency during recent decades in both maritime and continental parts of Europe although the maximum in frequency of extreme values occurred in the transition period 1930-1950.

  7. Electron energy spectrum and maximum disruption angle under multi...

    Office of Scientific and Technical Information (OSTI)

    Conference: Electron energy spectrum and maximum disruption angle under multi-photon beamstrahlung Citation Details In-Document Search Title: Electron energy spectrum and maximum ...

  8. Electron energy spectrum and maximum disruption angle under multi...

    Office of Scientific and Technical Information (OSTI)

    Electron energy spectrum and maximum disruption angle under multi-photon beamstrahlung Citation Details In-Document Search Title: Electron energy spectrum and maximum disruption ...

  9. Oxidation State Optimization for Maximum Efficiency of NOx Adsorber...

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

    State Optimization for Maximum Efficiency of NOx Adsorber Catalysts Oxidation State Optimization for Maximum Efficiency of NOx Adsorber Catalysts Presentation given at the 16th ...

  10. Theoretical Estimate of Maximum Possible Nuclear Explosion

    DOE R&D Accomplishments [OSTI]

    Bethe, H. A.

    1950-01-31

    The maximum nuclear accident which could occur in a Na-cooled, Be moderated, Pu and power producing reactor is estimated theoretically. (T.R.H.) 2O82 Results of nuclear calculations for a variety of compositions of fast, heterogeneous, sodium-cooled, U-235-fueled, plutonium- and power-producing reactors are reported. Core compositions typical of plate-, pin-, or wire-type fuel elements and with uranium as metal, alloy, and oxide were considered. These compositions included atom ratios in the following range: U-23B to U-235 from 2 to 8; sodium to U-235 from 1.5 to 12; iron to U-235 from 5 to 18; and vanadium to U-235 from 11 to 33. Calculations were performed to determine the effect of lead and iron reflectors between the core and blanket. Both natural and depleted uranium were evaluated as the blanket fertile material. Reactors were compared on a basis of conversion ratio, specific power, and the product of both. The calculated results are in general agreement with the experimental results from fast reactor assemblies. An analysis of the effect of new cross-section values as they became available is included. (auth)

  11. TRENDS IN ESTIMATED MIXING DEPTH DAILY MAXIMUMS

    SciTech Connect (OSTI)

    Buckley, R; Amy DuPont, A; Robert Kurzeja, R; Matt Parker, M

    2007-11-12

    Mixing depth is an important quantity in the determination of air pollution concentrations. Fireweather forecasts depend strongly on estimates of the mixing depth as a means of determining the altitude and dilution (ventilation rates) of smoke plumes. The Savannah River United States Forest Service (USFS) routinely conducts prescribed fires at the Savannah River Site (SRS), a heavily wooded Department of Energy (DOE) facility located in southwest South Carolina. For many years, the Savannah River National Laboratory (SRNL) has provided forecasts of weather conditions in support of the fire program, including an estimated mixing depth using potential temperature and turbulence change with height at a given location. This paper examines trends in the average estimated mixing depth daily maximum at the SRS over an extended period of time (4.75 years) derived from numerical atmospheric simulations using two versions of the Regional Atmospheric Modeling System (RAMS). This allows for differences to be seen between the model versions, as well as trends on a multi-year time frame. In addition, comparisons of predicted mixing depth for individual days in which special balloon soundings were released are also discussed.

  12. Extended maximum likelihood halo-independent analysis of dark matter direct detection data

    SciTech Connect (OSTI)

    Gelmini, Graciela B.; Georgescu, Andreea; Gondolo, Paolo; Huh, Ji-Haeng

    2015-11-24

    We extend and correct a recently proposed maximum-likelihood halo-independent method to analyze unbinned direct dark matter detection data. Instead of the recoil energy as independent variable we use the minimum speed a dark matter particle must have to impart a given recoil energy to a nucleus. This has the advantage of allowing us to apply the method to any type of target composition and interaction, e.g. with general momentum and velocity dependence, and with elastic or inelastic scattering. We prove the method and provide a rigorous statistical interpretation of the results. As first applications, we find that for dark matter particles with elastic spin-independent interactions and neutron to proton coupling ratio f{sub n}/f{sub p}=−0.7, the WIMP interpretation of the signal observed by CDMS-II-Si is compatible with the constraints imposed by all other experiments with null results. We also find a similar compatibility for exothermic inelastic spin-independent interactions with f{sub n}/f{sub p}=−0.8.

  13. Maximum Likelihood Analysis of Low Energy CDMS II Germanium Data

    SciTech Connect (OSTI)

    Agnese, R.

    2015-03-30

    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 experiment using a maximum likelihood analysis. A background model is constructed using GEANT4 to simulate the surface-event background from Pb210decay-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 also 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. Finally, 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.

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

    Open Energy Info (EERE)

    Velocity(ms) Jump to: navigation, search Property Name Maximum Velocity(ms) Property Type String Pages using the property "Maximum Velocity(ms)" Showing 25 pages using this...

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

    Open Energy Info (EERE)

    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...

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

    Open Energy Info (EERE)

    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....

  17. Variable Valve Actuation

    SciTech Connect (OSTI)

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the

  18. Near-IR spectroscopic monitoring of CLASS I protostars: Variability of accretion and wind indicators

    SciTech Connect (OSTI)

    Connelley, Michael S.; Greene, Thomas P.

    2014-06-01

    We present the results of a program that monitored the near-IR spectroscopic variability of a sample of 19 embedded protostars. Spectra were taken on time intervals from 2 days to 3 yr, over a wavelength range from 0.85 ?m to 2.45 ?m, for 4-9 epochs of observations per target. We found that the spectra of all targets are variable and that every emission feature observed is also variable (although not for all targets). With one exception, there were no drastic changes in the continua of the spectra, nor did any line completely disappear, nor did any line appear that was not previously apparent. This analysis focuses on understanding the connection between accretion (traced by H Br ? and CO) and the wind (traced by He I, [Fe II], and sometimes H{sub 2}). For both accretion and wind tracers, the median variability was constant versus the time interval between observations; however, the maximum variability that we observed increased with the time interval between observations. Extinction is observed to vary within the minimum sampling time of 2 days, suggesting extinguishing material within a few stellar radii at high disk latitudes. The variability of [Fe II] and H{sub 2} were correlated for most (but not all) of the 7 young stellar objects showing both features, and the amplitude of the variability depends on the veiling. Although the occurrence of CO and Br ? emission are connected, their variability is uncorrelated, suggesting that these emissions originate in separate regions near the protostar (e.g., disk and wind). The variability of Br ? and wind tracers were found to be positively correlated, negatively correlated, or uncorrelated, depending on the target. The variability of Br ?, [Fe II], and H{sub 2} always lies on a plane, although the orientation of the plane in three dimensions depends on the target. While we do not understand all interactions behind the variability that we observed, we have shown that spectroscopic variability is a powerful tool toward

  19. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by

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

    AERMOD-PRIME | Department of Energy PRIME Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Compliance based on highest, second-highest, short-term, and highest annual concentrations. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME (24.52

  20. Montana Total Maximum Daily Load Development Projects Wiki |...

    Open Energy Info (EERE)

    Wiki Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Montana Total Maximum Daily Load Development Projects Wiki Abstract Provides information on...

  1. Laser selection based on maximum permissible exposure limits...

    Office of Scientific and Technical Information (OSTI)

    Laser selection based on maximum permissible exposure limits for visible and middle-near infrared repetitively pulsed lasers. Citation Details In-Document Search Title: Laser ...

  2. Engineer End Uses for Maximum Efficiency | Department of Energy

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

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

  3. The Taiwanese-American occultation survey project stellar variability. III. Detection of 58 new variable stars

    SciTech Connect (OSTI)

    Ishioka, R.; Wang, S.-Y.; Zhang, Z.-W.; Lehner, M. J.; Cook, K. H.; King, S.-K.; Lee, T.; Marshall, S. L.; Schwamb, M. E.; Wang, J.-H.; Wen, C.-Y.; Alcock, C.; Protopapas, P.; Axelrod, T.; Bianco, F. B.; Byun, Y.-I.; Chen, W. P.; Ngeow, C.-C.; Kim, D.-W.; Rice, J. A.

    2014-04-01

    The Taiwanese-American Occultation Survey project is designed for the detection of stellar occultations by small-size Kuiper Belt Objects, and it has monitored selected fields along the ecliptic plane by using four telescopes with a 3 deg{sup 2} field of view on the sky since 2005. We have analyzed data accumulated during 2005-2012 to detect variable stars. Sixteen fields with observations of more than 100 epochs were examined. We recovered 85 variables among a total of 158 known variable stars in these 16 fields. Most of the unrecovered variables are located in the fields observed less frequently. We also detected 58 variable stars which are not listed in the International Variable Star Index of the American Association of Variable Star Observers. These variable stars are classified as 3 RR Lyrae, 4 Cepheid, 1 ? Scuti, 5 Mira, 15 semi-regular, and 27 eclipsing binaries based on the periodicity and the profile of the light curves.

  4. Maximum Likelihood Analysis of Low Energy CDMS II Germanium Data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Agnese, R.

    2015-03-30

    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 experiment using a maximum likelihood analysis. A background model is constructed using GEANT4 to simulate the surface-event background from Pb210decay-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 also 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 ourmore » data. Finally, 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.« less

  5. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by

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

    AERMOD-PRIME, Units 3, 1, 2 SO2 Case | Department of Energy PRIME, Units 3, 1, 2 SO2 Case Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 3, 1, 2 SO2 Case Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 3, 1, 2 SO2 Case. Compliance based on highest, second-highest, short-term, and highest annual concentrations. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME,

  6. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by

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

    AERMOD-PRIME, Units 4, 1, 2 SO2 Case | Department of Energy 4, 1, 2 SO2 Case Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 4, 1, 2 SO2 Case Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 4, 1, 2 SO2 Case. Compliance based on highest, second-highest, short-term, and highest annual concentrations. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 4, 1, 2

  7. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by

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

    AERMOD-PRIME, Units 5, 1, 2 SO2 Case | Department of Energy 5, 1, 2 SO2 Case Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 5, 1, 2 SO2 Case Docket No. EO-05-01: Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 5, 1, 2 SO2 Case. Compliance based on highest, second-highest, short-term, and highest annual concentrations. Mirant Potomac, Alexandria, Virginia: Maximum Impacts Predicted by AERMOD-PRIME, Units 5, 1, 2

  8. Bayesian data fusion for spatial prediction of categorical variables in environmental sciences

    SciTech Connect (OSTI)

    Gengler, Sarah Bogaert, Patrick

    2014-12-05

    First developed to predict continuous variables, Bayesian Maximum Entropy (BME) has become a complete framework in the context of space-time prediction since it has been extended to predict categorical variables and mixed random fields. This method proposes solutions to combine several sources of data whatever the nature of the information. However, the various attempts that were made for adapting the BME methodology to categorical variables and mixed random fields faced some limitations, as a high computational burden. The main objective of this paper is to overcome this limitation by generalizing the Bayesian Data Fusion (BDF) theoretical framework to categorical variables, which is somehow a simplification of the BME method through the convenient conditional independence hypothesis. The BDF methodology for categorical variables is first described and then applied to a practical case study: the estimation of soil drainage classes using a soil map and point observations in the sandy area of Flanders around the city of Mechelen (Belgium). The BDF approach is compared to BME along with more classical approaches, as Indicator CoKringing (ICK) and logistic regression. Estimators are compared using various indicators, namely the Percentage of Correctly Classified locations (PCC) and the Average Highest Probability (AHP). Although BDF methodology for categorical variables is somehow a simplification of BME approach, both methods lead to similar results and have strong advantages compared to ICK and logistic regression.

  9. Maximum Photovoltaic Penetration Levels on Typical Distribution Feeders: Preprint

    SciTech Connect (OSTI)

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

    2012-07-01

    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.

  10. Are There Practical Approaches for Achieving the Theoretical Maximum Engine

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

    Efficiency? | Department of Energy Are There Practical Approaches for Achieving the Theoretical Maximum Engine Efficiency? Are There Practical Approaches for Achieving the Theoretical Maximum Engine Efficiency? 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: University of Wisconsin, Madison 2004_deer_foster.pdf (273.98 KB) More Documents & Publications Fuel Modification t Facilitate Future Combustion Regimes? The Next ICE Age The Next ICE Age

  11. Table 10.1 Nonswitchable Minimum and Maximum Consumption, 2002

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

    Nonswitchable Minimum and Maximum Consumption, 2002; " " Level: National and Regional Data;" " Row: Energy Sources;" " Column: Consumption Potential;" " Unit: Physical Units." ,,,,"RSE" ,"Actual","Minimum","Maximum","Row" "Energy Sources","Consumption","Consumption(a)","Consumption(b)","Factors" ,"Total United States" "RSE Column

  12. Oxidation State Optimization for Maximum Efficiency of NOx Adsorber

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

    Catalysts | Department of Energy State Optimization for Maximum Efficiency of NOx Adsorber Catalysts Oxidation State Optimization for Maximum Efficiency of NOx Adsorber Catalysts Presentation given at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010. deer10_li.pdf (1.68 MB) More Documents & Publications Lean NOx Trap Regeneration Selectivity Towards N2O -- Similarities and Differences Between H2, CO and C3H6

  13. Diagnosis of extratropical variability in seasonal integrations of the ECMWF model

    SciTech Connect (OSTI)

    Ferranti, L.; Molteni, F.; Brankovic, C.; Palmer, T.N. )

    1994-06-01

    Properties of the general circulation simulated by the ECMWF model are discussed using a set of seasonal integrations at T63 resolution. For each season, over the period of 5 years, 1986-1990, three integrations initiated on consecutive days were run with prescribed observed sea surface temperature (SST). This paper presents a series of diagnostics of extratropical variability in the model, with particular emphasis on the northern winter. Time-filtered maps of variability indicate that in this season there is insufficient storm track activity penetrating into the Eurasian continent. Related to this the maximum of lower-frequency variability for northern spring are more realistic. Blocking is defined objectively in terms of the geostrophic wind at 500 mb. Consistent with the low-frequency transience, in the Euro-Atlantic sector the position of maximum blocking in the model is displaced eastward. The composite structure of blocks over the Pacific is realistic, though their frequency is severely underestimated at all times of year. Shortcomings in the simulated wintertime general circulation were also revealed by studying the projection of 5-day mean fields onto empirical orthogonal functions (EOFs) of the observed flow. The largest differences were apparent for statistics of EOFs of the zonal mean flow. Analysis of weather regime activity, defined from the EOFs, suggested that regimes with positive PNA index were overpopulated, while the negative PNA regimes were underpopulated. A further comparison between observed and modeled low-frequency variance revealed that underestimation of low-frequency variability occurs along the same axes that explain most of the spatial structure of the error in the mean field, suggesting a common dynamical origin for these two aspects of the systematic error. 17 refs., 17 figs., 4 tabs.

  14. Quality, precision and accuracy of the maximum No. 40 anemometer

    SciTech Connect (OSTI)

    Obermeir, J.; Blittersdorf, D.

    1996-12-31

    This paper synthesizes available calibration data for the Maximum No. 40 anemometer. Despite its long history in the wind industry, controversy surrounds the choice of transfer function for this anemometer. Many users are unaware that recent changes in default transfer functions in data loggers are producing output wind speed differences as large as 7.6%. Comparison of two calibration methods used for large samples of Maximum No. 40 anemometers shows a consistent difference of 4.6% in output speeds. This difference is significantly larger than estimated uncertainty levels. Testing, initially performed to investigate related issues, reveals that Gill and Maximum cup anemometers change their calibration transfer functions significantly when calibrated in the open atmosphere compared with calibration in a laminar wind tunnel. This indicates that atmospheric turbulence changes the calibration transfer function of cup anemometers. These results call into question the suitability of standard wind tunnel calibration testing for cup anemometers. 6 refs., 10 figs., 4 tabs.

  15. ARM - Publications: Science Team Meeting Documents: Observations...

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

    Observations of Natural Variability in Marine Stratocumulus Clouds Albrecht, Bruce University of Miami Kollias, Pavlos RSMASUniversity of Miami Jo, Ieng Rosentiel School of Marine ...

  16. VARIABLE TIME DELAY MEANS

    DOE Patents [OSTI]

    Clemensen, R.E.

    1959-11-01

    An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

  17. Variable Frequency Drives

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

    Marketing Toolkit The Benefits of Variable Frequency Drives (VFDs) VFDs help adjust motor speeds to match loads and improve efficiency while conserving energy. The benefits...

  18. Amplitude Variability in gamma Dor and delta Sct Stars Observed...

    Office of Scientific and Technical Information (OSTI)

    Research Org: Los Alamos National Laboratory (LANL) Sponsoring Org: WFO NASA, DOE SULI program Country of Publication: United States Language: English Subject: Astronomy & ...

  19. Amplitude Variability in gamma Dor and delta Sct Stars Observed...

    Office of Scientific and Technical Information (OSTI)

    Los Alamos National Laboratory Florida Institute of Technology, Melbourne, FL New Mexico State University, Las Cruces, NM Publication Date: 2015-10-19 OSTI Identifier: 1223775 ...

  20. Observed 20th Century Desert Dust Variability: Impact on Climate...

    Office of Scientific and Technical Information (OSTI)

    ... ORNL National Center for Atmospheric Research (NCAR) University of Maine University of Colorado, Boulder British Antarctic Survey, Cambridge, UK Publication Date: 2010-01-01 ...

  1. LITERATURE REVIEW ON MAXIMUM LOADING OF RADIONUCLIDES ON CRYSTALLINE SILICOTITANATE

    SciTech Connect (OSTI)

    Adu-Wusu, K.; Pennebaker, F.

    2010-10-13

    Plans are underway to use small column ion exchange (SCIX) units installed in high-level waste tanks to remove Cs-137 from highly alkaline salt solutions at Savannah River Site. The ion exchange material slated for the SCIX project is engineered or granular crystalline silicotitanate (CST). Information on the maximum loading of radionuclides on CST is needed by Savannah River Remediation for safety evaluations. A literature review has been conducted that culminated in the estimation of the maximum loading of all but one of the radionuclides of interest (Cs-137, Sr-90, Ba-137m, Pu-238, Pu-239, Pu-240, Pu-241, Am-241, and Cm-244). No data was found for Cm-244.

  2. Maximum patch method for directional dark matter detection

    SciTech Connect (OSTI)

    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)

    2008-07-01

    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.

  3. Industry guidelines for the calibration of maximum anemometers

    SciTech Connect (OSTI)

    Bailey, B.H.

    1996-12-31

    The purpose of this paper is to report on a framework of guidelines for the calibration of the Maximum Type 40 anemometer. This anemometer model is the wind speed sensor of choice in the majority of wind resource assessment programs in the U.S. These guidelines were established by the Utility Wind Resource Assessment Program. In addition to providing guidelines for anemometers, the appropriate use of non-calibrated anemometers is also discussed. 14 refs., 1 tab.

  4. Maximum Entry and Mandatory Separation Ages for Certain Security Employees

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

    2001-10-11

    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, supersedes DOE P 310.1.

  5. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

    Kevin L. Kenney; William A. Smith; Garold L. Gresham; Tyler L. Westover

    2013-01-01

    If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that due to inherent species variabilities, production conditions, and differing harvest, collection, and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture, and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

  6. Understanding Biomass Feedstock Variability

    SciTech Connect (OSTI)

    Kevin L. Kenney; Garold L. Gresham; William A. Smith; Tyler L. Westover

    2013-01-01

    If the singular goal of biomass logistics and the design of biomass feedstock supply systems is to reduce the per-ton supply cost of biomass, these systems may very well develop with ultimate unintended consequences of highly variable and reduced quality biomass feedstocks. This paper demonstrates that, due to inherent species variabilities, production conditions and differing harvest, collection and storage practices, this is a very real scenario that biomass producers and suppliers as well as conversion developers should be aware of. Biomass feedstock attributes of ash, carbohydrates, moisture and particle morphology will be discussed. We will also discuss specifications for these attributes, inherent variability of these attributes in biomass feedstocks, and approaches and solutions for reducing variability for improving feedstock quality.

  7. VARIABLE-THROW CAM

    DOE Patents [OSTI]

    Godsil, E.C.; Robinson, E.Y.

    1963-07-16

    A variable-throw cam comprising inner and outer eccentric sleeves which are adjustably locked together is described. The cam throw is varied by unlocking the inner and outer sleeves, rotating the outer sleeve relative to the inner one until the desired throw is obtained, and locking the sleeves together again. The cam is useful in applications wherein a continuously-variable throw is required, e.g., ram-and-die pressing operations, cyclic fatigue testing of materials, etc. (AEC)

  8. Analysis to determine the maximum dimensions of flexible apertures in sensored security netting products.

    SciTech Connect (OSTI)

    Murton, Mark; Bouchier, Francis A.; vanDongen, Dale T.; Mack, Thomas Kimball; Cutler, Robert Paul; Ross, Michael P.

    2013-08-01

    Although technological advances provide new capabilities to increase the robustness of security systems, they also potentially introduce new vulnerabilities. New capability sometimes requires new performance requirements. This paper outlines an approach to establishing a key performance requirement for an emerging intrusion detection sensor: the sensored net. Throughout the security industry, the commonly adopted standard for maximum opening size through barriers is a requirement based on square inches-typically 96 square inches. Unlike standard rigid opening, the dimensions of a flexible aperture are not fixed, but variable and conformable. It is demonstrably simple for a human intruder to move through a 96-square-inch opening that is conformable to the human body. The longstanding 96-square-inch requirement itself, though firmly embedded in policy and best practice, lacks a documented empirical basis. This analysis concluded that the traditional 96-square-inch standard for openings is insufficient for flexible openings that are conformable to the human body. Instead, a circumference standard is recommended for these newer types of sensored barriers. The recommended maximum circumference for a flexible opening should be no more than 26 inches, as measured on the inside of the netting material.

  9. Possible dynamical explanations for Paltridge's principle of maximum entropy production

    SciTech Connect (OSTI)

    Virgo, Nathaniel Ikegami, Takashi

    2014-12-05

    Throughout the history of non-equilibrium thermodynamics a number of theories have been proposed in which complex, far from equilibrium flow systems are hypothesised to reach a steady state that maximises some quantity. Perhaps the most celebrated is Paltridge's principle of maximum entropy production for the horizontal heat flux in Earth's atmosphere, for which there is some empirical support. There have been a number of attempts to derive such a principle from maximum entropy considerations. However, we currently lack a more mechanistic explanation of how any particular system might self-organise into a state that maximises some quantity. This is in contrast to equilibrium thermodynamics, in which models such as the Ising model have been a great help in understanding the relationship between the predictions of MaxEnt and the dynamics of physical systems. In this paper we show that, unlike in the equilibrium case, Paltridge-type maximisation in non-equilibrium systems cannot be achieved by a simple dynamical feedback mechanism. Nevertheless, we propose several possible mechanisms by which maximisation could occur. Showing that these occur in any real system is a task for future work. The possibilities presented here may not be the only ones. We hope that by presenting them we can provoke further discussion about the possible dynamical mechanisms behind extremum principles for non-equilibrium systems, and their relationship to predictions obtained through MaxEnt.

  10. Neutrino Observations

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

    Observations from the Sudbury Neutrino Observatory A.W.P. Poon 1 Institute for Nuclear and Particle Astrophysics, Lawrence Berkeley National Laboratory, Berkeley, CA, USA Abstract. The Sudbury Neutrino Observatory (SNO) is a water imaging Cherenkov detector. Its usage of 1000 metric tons of D 2 O as target allows the SNO detector to make a solar-model independent test of the neutrino oscillation hypothesis by simultaneously measuring the solar ν e flux and the total flux of all active neutrino

  11. State observer for synchronous motors

    DOE Patents [OSTI]

    Lang, Jeffrey H.

    1994-03-22

    A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

  12. SPECTROPOLARIMETRY OF THE TYPE Ia SN 2007sr TWO MONTHS AFTER MAXIMUM LIGHT

    SciTech Connect (OSTI)

    Zelaya, P.; Quinn, J. R.; Clocchiatti, A.; Baade, D.; Patat, F.; Hoeflich, P.; Maund, J.; Wang, L.; Wheeler, J. C.

    2013-02-01

    We present late-time spectropolarimetric observations of SN 2007sr, obtained with the Very Large Telescope at the ESO Paranal Observatory when the object was 63 days after maximum light. The late-time spectrum displays strong line polarization in the Ca II absorption features. SN 2007sr adds to the case of some normal Type Ia supernovae that show high line polarization or repolarization at late times, a fact that might be connected with the presence of high-velocity features at early times.

  13. Conductivity maximum in a charged colloidal suspension (Journal...

    Office of Scientific and Technical Information (OSTI)

    effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we...

  14. Reduction in maximum time uncertainty of paired time signals

    DOE Patents [OSTI]

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

    1983-10-04

    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][<=]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--800. 6 figs.

  15. Reduction in maximum time uncertainty of paired time signals

    DOE Patents [OSTI]

    Theodosiou, George E.; Dawson, John W.

    1983-01-01

    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 .ltoreq.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 20-800.

  16. Reduction in maximum time uncertainty of paired time signals

    DOE Patents [OSTI]

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

    1981-02-11

    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.

  17. Property:Maximum Velocity with Constriction(m/s) | Open Energy...

    Open Energy Info (EERE)

    Velocity with Constriction(ms) Jump to: navigation, search Property Name Maximum Velocity with Constriction(ms) Property Type String Pages using the property "Maximum Velocity...

  18. Variable thrust cartridge

    DOE Patents [OSTI]

    Taleyarkhan, Rusi P.

    2000-11-07

    The present invention is a variable thrust cartridge comprising a water-molten aluminum reaction chamber from which a slug is propelled. The cartridge comprises a firing system that initiates a controlled explosion from the reaction chamber. The explosive force provides a thrust to a slug, preferably contained within the cartridge.

  19. Variable capacity gasification burner

    SciTech Connect (OSTI)

    Saxon, D.I.

    1985-03-05

    A variable capacity burner that may be used in gasification processes, the burner being adjustable when operating in its intended operating environment to operate at two different flow capacities, with the adjustable parts being dynamically sealed within a statically sealed structural arrangement to prevent dangerous blow-outs of the reactants to the atmosphere.

  20. Estimate of Maximum Underground Working Gas Storage Capacity in the United States

    Reports and Publications (EIA)

    2006-01-01

    This report examines the aggregate maximum capacity for U.S. natural gas storage. Although the concept of maximum capacity seems quite straightforward, there are numerous issues that preclude the determination of a definitive maximum volume. The report presents three alternative estimates for maximum capacity, indicating appropriate caveats for each.

  1. Boiler Maximum Achievable Control Technology (MACT) Technical Assistance- Fact Sheet, April 2015

    Broader source: Energy.gov [DOE]

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

  2. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect (OSTI)

    Don Augenstein

    2001-02-01

    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.

  3. Maximum voltage gradient, uniformity and brightness of dispenser cathodes

    SciTech Connect (OSTI)

    Turner, W.C.; Chen, Y.J.; Green, M.C.; Miram, G.V.; Nordquist, A.L.

    1988-01-01

    Initial measurements of current uniformity and intrinsic cathode brightness are presented a 5.1 cm diameter osmium alloy coated dispenser cathode. The data are obtained with a planar diode driven with a 35ns Blumlein pulse line. Pepper pot images are observed with a fast phosphor and gated camera. The current density and beamlet divergence angle are uniform within +-10% and a brightness J = 1.6E10A/m/sup 2/rad/sup 2/ is observed at a current density j=44A/cm/sup 2/. 6 refs., 2 figs., 2 tabs.

  4. Variable depth core sampler

    DOE Patents [OSTI]

    Bourgeois, Peter M.; Reger, Robert J.

    1996-01-01

    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.

  5. Variable depth core sampler

    DOE Patents [OSTI]

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

    1996-02-20

    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.

  6. Variable percentage sampler

    DOE Patents [OSTI]

    Miller, Jr., William H.

    1976-01-01

    A remotely operable sampler is provided for obtaining variable percentage samples of nuclear fuel particles and the like for analyses. The sampler has a rotating cup for a sample collection chamber designed so that the effective size of the sample inlet opening to the cup varies with rotational speed. Samples of a desired size are withdrawn from a flowing stream of particles without a deterrent to the flow of remaining particles.

  7. Variable laser attenuator

    DOE Patents [OSTI]

    Foltyn, Stephen R.

    1988-01-01

    The disclosure relates to low loss, high power variable attenuators comprng 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.

  8. Variable laser attenuator

    DOE Patents [OSTI]

    Foltyn, S.R.

    1987-05-29

    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.

  9. Regional Climate Effects of Aerosols Over China: Modeling and Observation

    SciTech Connect (OSTI)

    Qian, Yun; Leung, Lai R.; Ghan, Steven J.; Giorgi, Filippo

    2003-09-01

    We present regional simulations of aerosol properties, direct radiative forcing and aerosol climatic effects over China, and compare the simulations with observed aerosol characteristics and climatic data over the region. The climate simulations are performed with a regional climate model, which is shown to capture the spatial distribution and seasonal pattern of temperature and precipitation. Aerosol concentrations are obtained from a global tracer-transport model and are provided to the regional model for the calculation of radiative forcing. Different aerosols are included: sulfate, organic carbon, black carbon, mineral dust, and sea salt and MSA particles. Generally, the aerosol optical depth is well simulated in both magnitude and spatial distribution. The direct radiative forcing of the aerosol is in the range of –1 to –14 W m-2 in autumn and summer and -1 to –9 W m-2 in spring and winter, with substantial spatial variability at the regional scale. A strong maximum in aerosol optical depth and negative radiative forcing is found over the Sichuan Basin. The negative radiative forcing of aerosol induces a surface cooling in the range of –0.6 to –1.2oC in autumn and winter, –0.3 to –0.6oC in spring and 0.0 to –0.9oC in summer throughout East China. The aerosol-induced cooling is mainly due to a decrease in day-time maximum temperature. The cooling is maximum and is statistically significant over the Sichuan Basin. The effect of aerosol on precipitation is not evident in our simulations. The temporal and spatial patterns of the temperature trends observed in the second half of the twentieth century, including different trends for daily maximum and minimum temperature, are at least qualitatively consistent with the simulated aerosol-induced cooling over the Sichuan Basin and East China. This result supports the hypothesis that the observed temperature trends during the latter decades of the twentieth century, especially the cooling trends over the

  10. Weakest solar wind of the space age and the current 'MINI' solar maximum

    SciTech Connect (OSTI)

    McComas, D. J.; Angold, N.; Elliott, H. A.; Livadiotis, G.; Schwadron, N. A.; Smith, C. W.; Skoug, R. M.

    2013-12-10

    The last solar minimum, which extended into 2009, was especially deep and prolonged. Since then, sunspot activity has gone through a very small peak while the heliospheric current sheet achieved large tilt angles similar to prior solar maxima. The solar wind fluid properties and interplanetary magnetic field (IMF) have declined through the prolonged solar minimum and continued to be low through the current mini solar maximum. Compared to values typically observed from the mid-1970s through the mid-1990s, the following proton parameters are lower on average from 2009 through day 79 of 2013: solar wind speed and beta (?11%), temperature (?40%), thermal pressure (?55%), mass flux (?34%), momentum flux or dynamic pressure (?41%), energy flux (?48%), IMF magnitude (?31%), and radial component of the IMF (?38%). These results have important implications for the solar wind's interaction with planetary magnetospheres and the heliosphere's interaction with the local interstellar medium, with the proton dynamic pressure remaining near the lowest values observed in the space age: ?1.4 nPa, compared to ?2.4 nPa typically observed from the mid-1970s through the mid-1990s. The combination of lower magnetic flux emergence from the Sun (carried out in the solar wind as the IMF) and associated low power in the solar wind points to the causal relationship between them. Our results indicate that the low solar wind output is driven by an internal trend in the Sun that is longer than the ?11 yr solar cycle, and they suggest that this current weak solar maximum is driven by the same trend.

  11. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect (OSTI)

    Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta

    2000-02-26

    Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role both in reduction of US greenhouse gas emissions and in US renewable energy. 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

  12. Maximum-likelihood fitting of data dominated by Poisson statistical uncertainties

    SciTech Connect (OSTI)

    Stoneking, M.R.; Den Hartog, D.J.

    1996-06-01

    The fitting of data by {chi}{sup 2}-minimization is valid only when the uncertainties in the data are normally distributed. When analyzing spectroscopic or particle counting data at very low signal level (e.g., a Thomson scattering diagnostic), the uncertainties are distributed with a Poisson distribution. The authors have developed a maximum-likelihood method for fitting data that correctly treats the Poisson statistical character of the uncertainties. This method maximizes the total probability that the observed data are drawn from the assumed fit function using the Poisson probability function to determine the probability for each data point. The algorithm also returns uncertainty estimates for the fit parameters. They compare this method with a {chi}{sup 2}-minimization routine applied to both simulated and real data. Differences in the returned fits are greater at low signal level (less than {approximately}20 counts per measurement). the maximum-likelihood method is found to be more accurate and robust, returning a narrower distribution of values for the fit parameters with fewer outliers.

  13. Estimates of maximum strains induced in buried pipelines by dynamic loading

    SciTech Connect (OSTI)

    Fernandez, G.; Al-Chaar, G.; Brady, P.

    1995-12-31

    An evaluation of pipe strains measured during full scale blast in-situ tests was carried out to assess the effects produced by a nearby quarry blast in a buried, steel pipeline carrying pressurized gas. The result of the blast tests indicated that the magnitude of the maximum circumferential strain is equal or larger than the magnitude of the maximum axial strain measured in the pipe. It was also observed that circumferential strains can develop simultaneously with the dynamic-induced axial strains, resulting in a more critical loading condition than the one contemplated by the ASCE (1983) design guidelines for seismic loading. This behavior can become critical in pressurized pipes where significant circumferential stresses are already present under normal operating conditions. Based on the results of these tests, recommendations for including circumferential strains are suggested to the ASCE (1983) Design Guidelines. Consideration should be given to a compressive wave traveling at a high angle which respect to the longitudinal axis of the pipe which can induce squeezing or ovaling of the pipe section, resulting in significant circumferential strains in the pipe.

  14. Variable leak gas source

    DOE Patents [OSTI]

    Henderson, Timothy M.; Wuttke, Gilbert H.

    1977-01-01

    A variable leak gas source and a method for obtaining the same which includes filling a quantity of hollow glass micro-spheres with a gas, storing said quantity in a confined chamber having a controllable outlet, heating said chamber above room temperature, and controlling the temperature of said chamber to control the quantity of gas passing out of said controllable outlet. Individual gas filled spheres may be utilized for calibration purposes by breaking a sphere having a known quantity of a known gas to calibrate a gas detection apparatus.

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

    SciTech Connect (OSTI)

    Urniezius, Renaldas

    2011-03-14

    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.

  16. A 3D approximate maximum likelihood solver for localization of fish implanted with acoustic transmitters

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Xinya; Deng, Z. Daniel; USA, Richland Washington; Sun, Yannan; USA, Richland Washington; Martinez, Jayson J.; USA, Richland Washington; Fu, Tao; USA, Richland Washington; McMichael, Geoffrey A.; et al

    2014-11-27

    Better understanding of fish behavior is vital for recovery of many endangered species including salmon. The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed to observe the out-migratory behavior of juvenile salmonids tagged by surgical implantation of acoustic micro-transmitters and to estimate the survival when passing through dams on the Snake and Columbia Rivers. A robust three-dimensional solver was needed to accurately and efficiently estimate the time sequence of locations of fish tagged with JSATS acoustic transmitters, to describe in sufficient detail the information needed to assess the function of dam-passage design alternatives. An approximate maximum likelihood solver was developedmore » using measurements of time difference of arrival from all hydrophones in receiving arrays on which a transmission was detected. Field experiments demonstrated that the developed solver performed significantly better in tracking efficiency and accuracy than other solvers described in the literature.« less

  17. A 3D approximate maximum likelihood solver for localization of fish implanted with acoustic transmitters

    SciTech Connect (OSTI)

    Li, Xinya; Deng, Z. Daniel; USA, Richland Washington; Sun, Yannan; USA, Richland Washington; Martinez, Jayson J.; USA, Richland Washington; Fu, Tao; USA, Richland Washington; McMichael, Geoffrey A.; USA, Richland Washington; Carlson, Thomas J.; USA, Richland Washington

    2014-11-27

    Better understanding of fish behavior is vital for recovery of many endangered species including salmon. The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed to observe the out-migratory behavior of juvenile salmonids tagged by surgical implantation of acoustic micro-transmitters and to estimate the survival when passing through dams on the Snake and Columbia Rivers. A robust three-dimensional solver was needed to accurately and efficiently estimate the time sequence of locations of fish tagged with JSATS acoustic transmitters, to describe in sufficient detail the information needed to assess the function of dam-passage design alternatives. An approximate maximum likelihood solver was developed using measurements of time difference of arrival from all hydrophones in receiving arrays on which a transmission was detected. Field experiments demonstrated that the developed solver performed significantly better in tracking efficiency and accuracy than other solvers described in the literature.

  18. Device for adapting continuously variable transmissions to infinitely variable transmissions with forward-neutral-reverse capabilities

    DOE Patents [OSTI]

    Wilkes, Donald F.; Purvis, James W.; Miller, A. Keith

    1997-01-01

    An infinitely variable transmission is capable of operating between a maximum speed in one direction and a minimum speed in an opposite direction, including a zero output angular velocity, while being supplied with energy at a constant angular velocity. Input energy is divided between a first power path carrying an orbital set of elements and a second path that includes a variable speed adjustment mechanism. The second power path also connects with the orbital set of elements in such a way as to vary the rate of angular rotation thereof. The combined effects of power from the first and second power paths are combined and delivered to an output element by the orbital element set. The transmission can be designed to operate over a preselected ratio of forward to reverse output speeds.

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

    Open Energy Info (EERE)

    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...

  20. 2011-07 "Maximum Utilization of WIPP by Increasing MDA G TRU...

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

    7 "Maximum Utilization of WIPP by Increasing MDA G TRU Shipments" 2011-07 "Maximum Utilization of WIPP by Increasing MDA G TRU Shipments" The intent of this recommendation is to ...

  1. Phase-resolved XMM-Newton and swift observations of WR 25

    SciTech Connect (OSTI)

    Pandey, J. C.; Pandey, S. B.; Karmakar, Subhajeet

    2014-06-10

    We present an analysis of long-term X-ray and optical observations of the Wolf-Rayet binary, WR 25. Using archival data from observations with the XMM-Newton and the Swift observatories, spanning over ∼10 yr, we show that WR 25 is a periodic variable in X-rays with a period of 208 ± 3 days. X-ray light curves in the 0.5-10.0 keV energy band show phase-locked variability, where the flux increased by a factor of ∼2 from minimum to maximum, being maximum near periastron passage. The light curve in the soft energy band (0.5-2.0 keV) shows two minima indicating the presence of two eclipses. However, the light curve in the hard energy band (2.0-10.0 keV) shows only one minimum during the apastron passage. The X-ray spectra of WR 25 were explained by a two-temperature plasma model. Both the cool and the hot plasmas were constant at 0.628 ± 0.008 and 2.75 ± 0.06 keV throughout an orbital cycle, where the cooler plasma could be due to small scale shocks in a radiation-driven outflow and the high temperature plasma could be due to the collision of winds. The column density varied with the orbital phase and was found to be maximum after the periastron passage, when the WN star is in front of the O star. The abundances of WR 25 were found to be non-solar. Optical V-band data of WR 25 also show the phase-locked variability, being at maximum near periastron passage. The results based on the present analysis indicate that WR 25 is a colliding wind binary where the presence of soft X-rays is attributed to individual components; however, hard X-rays are due to the collision of winds.

  2. VARIABLE TIME-INTERVAL GENERATOR

    DOE Patents [OSTI]

    Gross, J.E.

    1959-10-31

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

  3. Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV

    SciTech Connect (OSTI)

    Abraham, J.; Abreu, P.; Aglietta, M.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; /Lisbon, IST /Boskovic Inst., Zagreb

    2010-02-01

    We describe the measurement of the depth of maximum, X{sub max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10{sup 18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{sub -21}{sup +35}) g/cm{sup 2}/decade below 10{sup 18.24 {+-} 0.05}eV, and (24 {+-} 3) g/cm{sup 2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{sup 2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

  4. Application Performance Variability on Hopper

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

    Application Performance Variability on Hopper Application Performance Variability on Hopper Introduction The Hopper system is a Cray XE6 system with roughly 6300 compute nodes. In normal day to day operations, Hopper can be running hundreds of individual applications at any given time. Some users have reported application runtime variability, in some cases as large as 30-40%. Non-uniform runtimes makes it more difficult for scientists to measure the performance of their codes and to estimate the

  5. VariableR reclustering in multiple top quark events - Oral Presentatio...

    Office of Scientific and Technical Information (OSTI)

    VariableR reclustering in multiple top quark events - Oral Presentation Citation Details In-Document Search Title: VariableR reclustering in multiple top quark events - Oral...

  6. Sandia defines solar variability zones

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

    defines solar variability zones - Sandia Energy Energy Search Icon Sandia Home Locations ... Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power ...

  7. NREL: Transmission Grid Integration - Variability of Renewable...

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

    Variability of Renewable Energy Sources Wind and solar energy are referred to as variable generation sources because their ... at a single site is significantly less variable. ...

  8. Maximum allowable hydraulic ram force for heel jet removal Tank 241-C-106

    SciTech Connect (OSTI)

    PAULSEN, S.S.

    2003-01-10

    This document contains an evaluation of the maximum force that can be used to actuate the hydraulic ram assembly without causing permanent damage to the riser or pit.

  9. Alaska Maximum Number of Active Crews Engaged in Three-Dimensional...

    Gasoline and Diesel Fuel Update (EIA)

    Three-Dimensional Seismic Surveying (Number of Elements) Alaska Maximum Number of Active Crews Engaged in Three-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar...

  10. Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey

    SciTech Connect (OSTI)

    Huber, M E; Everett, M E; Howell, S B

    2005-03-07

    The authors present an analysis of the color and variability characteristics for point sources in the Faint Sky Variability Survey (FSVS). The FSVS cataloged {approx} 23 square degrees in BVI filters from {approx} 16-24 mag to investigate variability in faint sources at moderate to high Galactic latitudes. Point source completeness is found to be >83% for a selected representative sample (V - 17.5-22.0 mag, B-V = 0.0-1.5) containing both photometric B, V detections and 80% of the time-sampled V data available compared to a basic internal source completeness of 99%. Multi-epoch (10-30) observations in V spanning minutes to years modeled by light curve simulations reveal amplitude sensitivities to {approx} 0.015-0.075 mag over a representative V = 18-22 mag range. Periodicity determinations appear viable to time-scales of an order 1 day or less using the most sampled fields ({approx} 30 epochs). The fraction of point sources is found to be generally variable at 5-8% over V = 17.5-22.0 mag. For V brighter than 19 mag, the variable population is dominated by low amplitude (< 0.05 mag) and blue (B-V < 0.35) sources, possibly representing a population of {gamma} Doradus stars. Overall, the dominant population of variable sources are bluer than B-V = 0.65 and have Main Sequence colors, likely reflecting larger populations of RR Lyrae, SX Phe, {gamma} Doradus, and W UMa variables.

  11. TabVar: Tabulated Variables

    Energy Science and Technology Software Center (OSTI)

    2015-12-15

    TabVar: A Python library for manipulating datasets in the form of tabulated variables. Tables in tabvar contain many columns representing independent variables, but exactly one distinguished column for the dependent variable. Having a single distinguished column allows a natural lifting of arithmetic operators to tables, much (and in fact fully generalizing) multidimensional array arithmetic. The convenient syntax of whole-table arithmetic, along with the usual operations of filtering and aggregation, and all in the setting ofmore » python's interactive REPL allows for rapid exploration of datasets.« less

  12. Variable metric conjugate gradient methods

    SciTech Connect (OSTI)

    Barth, T.; Manteuffel, T.

    1994-07-01

    1.1 Motivation. In this paper we present a framework that includes many well known iterative methods for the solution of nonsymmetric linear systems of equations, Ax = b. Section 2 begins with a brief review of the conjugate gradient method. Next, we describe a broader class of methods, known as projection methods, to which the conjugate gradient (CG) method and most conjugate gradient-like methods belong. The concept of a method having either a fixed or a variable metric is introduced. Methods that have a metric are referred to as either fixed or variable metric methods. Some relationships between projection methods and fixed (variable) metric methods are discussed. The main emphasis of the remainder of this paper is on variable metric methods. In Section 3 we show how the biconjugate gradient (BCG), and the quasi-minimal residual (QMR) methods fit into this framework as variable metric methods. By modifying the underlying Lanczos biorthogonalization process used in the implementation of BCG and QMR, we obtain other variable metric methods. These, we refer to as generalizations of BCG and QMR.

  13. Frequency dependence of the maximum operating temperature for quantum-cascade lasers up to 5.4 THz

    SciTech Connect (OSTI)

    Wienold, M.; Röben, B.; Lü, X.; Rozas, G.; Schrottke, L.; Biermann, K.; Grahn, H. T.

    2015-11-16

    We report on the observation of an approximately linear reduction in the maximum operating temperature with an increasing emission frequency for terahertz quantum-cascade lasers between 4.2 and 5.4 THz. These lasers are based on the same design type, but vary in period length and barrier height for the cascade structure. The sample emitting at the highest frequency around 5.4 THz can be operated in pulsed mode up to 56 K. We identify an additional relaxation channel for electrons by longitudinal optical phonon scattering from the upper to the lower laser level and increasing optical losses toward higher frequencies as major processes, leading to the observed temperature behavior.

  14. Maximum likelihood Bayesian model averaging and its predictive analysis for groundwater reactive transport models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lu, Dan; Ye, Ming; Curtis, Gary P.

    2015-08-01

    While Bayesian model averaging (BMA) has been widely used in groundwater modeling, it is infrequently applied to groundwater reactive transport modeling because of multiple sources of uncertainty in the coupled hydrogeochemical processes and because of the long execution time of each model run. To resolve these problems, this study analyzed different levels of uncertainty in a hierarchical way, and used the maximum likelihood version of BMA, i.e., MLBMA, to improve the computational efficiency. Our study demonstrates the applicability of MLBMA to groundwater reactive transport modeling in a synthetic case in which twenty-seven reactive transport models were designed to predict themore » reactive transport of hexavalent uranium (U(VI)) based on observations at a former uranium mill site near Naturita, CO. Moreover, these reactive transport models contain three uncertain model components, i.e., parameterization of hydraulic conductivity, configuration of model boundary, and surface complexation reactions that simulate U(VI) adsorption. These uncertain model components were aggregated into the alternative models by integrating a hierarchical structure into MLBMA. The modeling results of the individual models and MLBMA were analyzed to investigate their predictive performance. The predictive logscore results show that MLBMA generally outperforms the best model, suggesting that using MLBMA is a sound strategy to achieve more robust model predictions relative to a single model. MLBMA works best when the alternative models are structurally distinct and have diverse model predictions. When correlation in model structure exists, two strategies were used to improve predictive performance by retaining structurally distinct models or assigning smaller prior model probabilities to correlated models. Since the synthetic models were designed using data from the Naturita site, the results of this study are expected to provide guidance for real-world modeling. Finally

  15. Maximum likelihood Bayesian model averaging and its predictive analysis for groundwater reactive transport models

    SciTech Connect (OSTI)

    Lu, Dan; Ye, Ming; Curtis, Gary P.

    2015-08-01

    While Bayesian model averaging (BMA) has been widely used in groundwater modeling, it is infrequently applied to groundwater reactive transport modeling because of multiple sources of uncertainty in the coupled hydrogeochemical processes and because of the long execution time of each model run. To resolve these problems, this study analyzed different levels of uncertainty in a hierarchical way, and used the maximum likelihood version of BMA, i.e., MLBMA, to improve the computational efficiency. Our study demonstrates the applicability of MLBMA to groundwater reactive transport modeling in a synthetic case in which twenty-seven reactive transport models were designed to predict the reactive transport of hexavalent uranium (U(VI)) based on observations at a former uranium mill site near Naturita, CO. Moreover, these reactive transport models contain three uncertain model components, i.e., parameterization of hydraulic conductivity, configuration of model boundary, and surface complexation reactions that simulate U(VI) adsorption. These uncertain model components were aggregated into the alternative models by integrating a hierarchical structure into MLBMA. The modeling results of the individual models and MLBMA were analyzed to investigate their predictive performance. The predictive logscore results show that MLBMA generally outperforms the best model, suggesting that using MLBMA is a sound strategy to achieve more robust model predictions relative to a single model. MLBMA works best when the alternative models are structurally distinct and have diverse model predictions. When correlation in model structure exists, two strategies were used to improve predictive performance by retaining structurally distinct models or assigning smaller prior model probabilities to correlated models. Since the synthetic models were designed using data from the Naturita site, the results of this study are expected to provide guidance for real-world modeling. Finally, limitations of

  16. Setting the Renormalization Scale in QCD: The Principle of Maximum Conformality

    SciTech Connect (OSTI)

    Brodsky, Stanley J.; Di Giustino, Leonardo; /SLAC

    2011-08-19

    A key problem in making precise perturbative QCD predictions is the uncertainty in determining the renormalization scale {mu} of the running coupling {alpha}{sub s}({mu}{sup 2}): The purpose of the running coupling in any gauge theory is to sum all terms involving the {beta} function; in fact, when the renormalization scale is set properly, all non-conformal {beta} {ne} 0 terms in a perturbative expansion arising from renormalization are summed into the running coupling. The remaining terms in the perturbative series are then identical to that of a conformal theory; i.e., the corresponding theory with {beta} = 0. The resulting scale-fixed predictions using the 'principle of maximum conformality' (PMC) are independent of the choice of renormalization scheme - a key requirement of renormalization group invariance. The results avoid renormalon resummation and agree with QED scale-setting in the Abelian limit. The PMC is also the theoretical principle underlying the BLM procedure, commensurate scale relations between observables, and the scale-setting method used in lattice gauge theory. The number of active flavors nf in the QCD {beta} function is also correctly determined. We discuss several methods for determining the PMC/BLM scale for QCD processes. We show that a single global PMC scale, valid at leading order, can be derived from basic properties of the perturbative QCD cross section. The elimination of the renormalization scheme ambiguity using the PMC will not only increase the precision of QCD tests, but it will also increase the sensitivity of collider experiments to new physics beyond the Standard Model.

  17. U.S. Lower 48 States Offshore Maximum Number of Active Crews...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Offshore Maximum Number of Active Crews Engaged in Seismic Surveying (Number of Elements) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9 2000's 167...

  18. U.S. Lower 48 States Onshore Maximum Number of Active Crews Engaged...

    Gasoline and Diesel Fuel Update (EIA)

    Onshore Maximum Number of Active Crews Engaged in Seismic Surveying (Number of Elements) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9 2000's 435 512...

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

    Gasoline and Diesel Fuel Update (EIA)

    Maximum Number of Active Crews Engaged in Seismic Surveying (Number of Elements) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9 2000's 615 717 624 481...

  20. Title 43 CFR 3206.12 What are the Minimum and Maximum Lease Sizes...

    Open Energy Info (EERE)

    .12 What are the Minimum and Maximum Lease Sizes? Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- Federal RegulationFederal Regulation: Title 43...

  1. Alaska Maximum Number of Active Crews Engaged in Two-Dimensional...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Two-Dimensional Seismic Surveying (Number of Elements) Alaska Maximum Number of Active Crews Engaged in Two-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar Apr...

  2. A Requirement for Significant Reduction in the Maximum BTU Input Rate of

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

    Decorative Vented Gas Fireplaces Would Impose Substantial Burdens on Manufacturers | Department of Energy A Requirement for Significant Reduction in the Maximum BTU Input Rate of Decorative Vented Gas Fireplaces Would Impose Substantial Burdens on Manufacturers A Requirement for Significant Reduction in the Maximum BTU Input Rate of Decorative Vented Gas Fireplaces Would Impose Substantial Burdens on Manufacturers Comment that a requirement to reduce the BTU input rate of existing decorative

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

    SciTech Connect (OSTI)

    Kim, Leonard; Narra, Venkat; Yue, Ning

    2013-07-01

    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.

  4. Variable focal length deformable mirror

    SciTech Connect (OSTI)

    Headley, Daniel; Ramsey, Marc; Schwarz, Jens

    2007-06-12

    A variable focal length deformable mirror has an inner ring and an outer ring that simply support and push axially on opposite sides of a mirror plate. The resulting variable clamping force deforms the mirror plate to provide a parabolic mirror shape. The rings are parallel planar sections of a single paraboloid and can provide an on-axis focus, if the rings are circular, or an off-axis focus, if the rings are elliptical. The focal length of the deformable mirror can be varied by changing the variable clamping force. The deformable mirror can generally be used in any application requiring the focusing or defocusing of light, including with both coherent and incoherent light sources.

  5. Operating Reserves and Variable Generation

    SciTech Connect (OSTI)

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

    2011-08-01

    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.

  6. Variable gas leak rate valve

    DOE Patents [OSTI]

    Eernisse, Errol P.; Peterson, Gary D.

    1976-01-01

    A variable gas leak rate valve which utilizes a poled piezoelectric element to control opening and closing of the valve. The gas flow may be around a cylindrical rod with a tubular piezoelectric member encircling the rod for seating thereagainst to block passage of gas and for reopening thereof upon application of suitable electrical fields.

  7. Application of asymptotic expansions for maximum likelihood estimators errors to gravitational waves from binary mergers: The single interferometer case

    SciTech Connect (OSTI)

    Zanolin, M.; Vitale, S.; Makris, N.

    2010-06-15

    In this paper we apply to gravitational waves (GW) from the inspiral phase of binary systems a recently derived frequentist methodology to calculate analytically the error for a maximum likelihood estimate of physical parameters. We use expansions of the covariance and the bias of a maximum likelihood estimate in terms of inverse powers of the signal-to-noise ration (SNR)s where the square root of the first order in the covariance expansion is the Cramer Rao lower bound (CRLB). We evaluate the expansions, for the first time, for GW signals in noises of GW interferometers. The examples are limited to a single, optimally oriented, interferometer. We also compare the error estimates using the first two orders of the expansions with existing numerical Monte Carlo simulations. The first two orders of the covariance allow us to get error predictions closer to what is observed in numerical simulations than the CRLB. The methodology also predicts a necessary SNR to approximate the error with the CRLB and provides new insight on the relationship between waveform properties, SNR, dimension of the parameter space and estimation errors. For example the timing match filtering can achieve the CRLB only if the SNR is larger than the Kurtosis of the gravitational wave spectrum and the necessary SNR is much larger if other physical parameters are also unknown.

  8. OBSERVING CORONAL NANOFLARES IN ACTIVE REGION MOSS

    SciTech Connect (OSTI)

    Testa, Paola; DeLuca, Ed; Golub, Leon; Korreck, Kelly; Weber, Mark; De Pontieu, Bart; Martinez-Sykora, Juan; Title, Alan; Hansteen, Viggo; Cirtain, Jonathan; Winebarger, Amy; Kobayashi, Ken; Kuzin, Sergey; Walsh, Robert; DeForest, Craig

    2013-06-10

    The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial ({approx}0.''3-0.''4) and temporal (5.5 s) resolution. The Hi-C observations show in some moss regions variability on timescales down to {approx}15 s, significantly shorter than the minute-scale variability typically found in previous observations of moss, therefore challenging the conclusion of moss being heated in a mostly steady manner. These rapid variability moss regions are located at the footpoints of bright hot coronal loops observed by the Solar Dynamics Observatory/Atmospheric Imaging Assembly in the 94 A channel, and by the Hinode/X-Ray Telescope. The configuration of these loops is highly dynamic, and suggestive of slipping reconnection. We interpret these events as signatures of heating events associated with reconnection occurring in the overlying hot coronal loops, i.e., coronal nanoflares. We estimate the order of magnitude of the energy in these events to be of at least a few 10{sup 23} erg, also supporting the nanoflare scenario. These Hi-C observations suggest that future observations at comparable high spatial and temporal resolution, with more extensive temperature coverage, are required to determine the exact characteristics of the heating mechanism(s).

  9. Verification of maximum impact force for interim storage cask for the Fast Flux Testing Facility

    SciTech Connect (OSTI)

    Chen, W.W.; Chang, S.J.

    1996-06-01

    The objective of this paper is to perform an impact analysis of the Interim Storage Cask (ISC) of the Fast Flux Test Facility (FFTF) for a 4-ft end drop. The ISC is a concrete cask used to store spent nuclear fuels. The analysis is to justify the impact force calculated by General Atomics (General Atomics, 1994) using the ILMOD computer code. ILMOD determines the maximum force developed by the concrete crushing which occurs when the drop energy has been absorbed. The maximum force, multiplied by the dynamic load factor (DLF), was used to determine the maximum g-level on the cask during a 4-ft end drop accident onto the heavily reinforced FFTF Reactor Service Building`s concrete surface. For the analysis, this surface was assumed to be unyielding and the cask absorbed all the drop energy. This conservative assumption simplified the modeling used to qualify the cask`s structural integrity for this accident condition.

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

    SciTech Connect (OSTI)

    Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.

    2012-12-01

    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

  11. "Table A52. Nonswitchable Minimum Requirements and Maximum Consumption"

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

    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" ,"-","-","-"

  12. Variable frequency microwave heating apparatus

    DOE Patents [OSTI]

    Bible, Don W.; Lauf, Robert J.; Johnson, Arvid C.; Thigpen, Larry T.

    1999-01-01

    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).

  13. On the Stochastic Maximum Principle in Optimal Control of Degenerate Diffusions with Lipschitz Coefficients

    SciTech Connect (OSTI)

    Bahlali, Khaled Djehiche, Boualem Mezerdi, Brahim

    2007-12-15

    We establish a stochastic maximum principle in optimal control of a general class of degenerate diffusion processes with global Lipschitz coefficients, generalizing the existing results on stochastic control of diffusion processes. We use distributional derivatives of the coefficients and the Bouleau Hirsh flow property, in order to define the adjoint process on an extension of the initial probability space.

  14. SALTSTONE DISPOSAL FACILITY: DETERMINATION OF THE PROBABLE MAXIMUM WATER TABLE ELEVATION

    SciTech Connect (OSTI)

    Hiergesell, R

    2005-04-01

    A coverage depicting the configuration of the probable maximum water table elevation in the vicinity of the Saltstone Disposal Facility (SDF) was developed to support the Saltstone program. This coverage is needed to support the construction of saltstone vaults to assure that they remain above the maximum elevation of the water table during the Performance Assessment (PA) period of compliance. A previous investigation to calculate the historical high water table beneath the SDF (Cook, 1983) was built upon to incorporate new data that has since become available to refine that estimate and develop a coverage that could be extended to the perennial streams adjacent to the SDF. This investigation incorporated the method used in the Cook, 1983 report to develop an estimate of the probable maximum water table for a group of wells that either existed at one time at or near the SDF or which currently exist. Estimates of the probable maximum water table at these wells were used to construct 2D contour lines depicting this surface beneath the SDF and extend them to the nearby hydrologic boundaries at the perennial streams adjacent to the SDF. Although certain measures were implemented to assure that the contour lines depict a surface above which the water table will not rise, the exact elevation of this surface cannot be known with complete certainty. It is therefore recommended that the construction of saltstone vaults incorporate a vertical buffer of at least 5-feet between the base of the vaults and the depicted probable maximum water table elevation. This should provide assurance that the water table under the wet extreme climatic condition will never rise to intercept the base of a vault.

  15. Observation of a periodic runaway in the reactive Ar/O{sub 2} high power impulse magnetron sputtering discharge

    SciTech Connect (OSTI)

    Shayestehaminzadeh, Seyedmohammad E-mail: shayesteh@mch.rwth-aachen.de; Arnalds, Unnar B.; Magnusson, Rögnvaldur L.; Olafsson, Sveinn

    2015-11-15

    This paper reports the observation of a periodic runaway of plasma to a higher density for the reactive discharge of the target material (Ti) with moderate sputter yield. Variable emission of secondary electrons, for the alternating transition of the target from metal mode to oxide mode, is understood to be the main reason for the runaway occurring periodically. Increasing the pulsing frequency can bring the target back to a metal (or suboxide) mode, and eliminate the periodic transition of the target. Therefore, a pulsing frequency interval is defined for the reactive Ar/O{sub 2} discharge in order to sustain the plasma in a runaway-free mode without exceeding the maximum power that the magnetron can tolerate.

  16. Variable area light reflecting assembly

    DOE Patents [OSTI]

    Howard, T.C.

    1986-12-23

    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.

  17. Variable area light reflecting assembly

    DOE Patents [OSTI]

    Howard, Thomas C.

    1986-01-01

    Device 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.

  18. HCCI in a Variable Compression Ratio Engine: Effects of Engine...

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

    in a Variable Compression Ratio Engine: Effects of Engine Variables HCCI in a Variable Compression Ratio Engine: Effects of Engine Variables 2004 Diesel Engine Emissions Reduction ...

  19. Nonferromagnetic linear variable differential transformer

    DOE Patents [OSTI]

    Ellis, James F.; Walstrom, Peter L.

    1977-06-14

    A nonferromagnetic linear variable differential transformer for accurately measuring mechanical displacements in the presence of high magnetic fields is provided. The device utilizes a movable primary coil inside a fixed secondary coil that consists of two series-opposed windings. Operation is such that the secondary output voltage is maintained in phase (depending on polarity) with the primary voltage. The transducer is well-suited to long cable runs and is useful for measuring small displacements in the presence of high or alternating magnetic fields.

  20. Variable Average Absolute Percent Differences

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

    Variable Average Absolute Percent Differences Percent of Projections Over- Estimated Gross Domestic Product Real Gross Domestic Product (Average Cumulative Growth)* (Table 2) 0.9 45.8 Petroleum Imported Refiner Acquisition Cost of Crude Oil (Constant $) (Table 3a) 37.7 17.3 Imported Refiner Acquisition Cost of Crude Oil (Nominal $) (Table 3b) 36.6 18.7 Total Petroleum Consumption (Table 4) 7.9 70.7 Crude Oil Production (Table 5) 8.1 51.1 Petroleum Net Imports (Table 6) 24.7 73.8 Natural Gas

  1. Variable flexure-based fluid filter

    DOE Patents [OSTI]

    Brown, Steve B.; Colston, Jr., Billy W.; Marshall, Graham; Wolcott, Duane

    2007-03-13

    An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.

  2. Geo-neutrino Observation

    SciTech Connect (OSTI)

    Dye, S. T.; Alderman, M.; Batygov, M.; Learned, J. G.; Matsuno, S.; Mahoney, J. M.; Pakvasa, S.; Rosen, M.; Smith, S.; Varner, G.; McDonough, W. F.

    2009-12-17

    Observations of geo-neutrinos measure radiogenic heat production within the earth, providing information on the thermal history and dynamic processes of the mantle. Two detectors currently observe geo-neutrinos from underground locations. Other detection projects in various stages of development include a deep ocean observatory. This paper presents the current status of geo-neutrino observation and describes the scientific capabilities of the deep ocean observatory, with emphasis on geology and neutrino physics.

  3. Hot Pot Field Observations

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

    Lane, Michael

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

  4. Hot Pot Field Observations

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

    Lane, Michael

    2013-06-28

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

  5. Variable frequency microwave furnace system

    DOE Patents [OSTI]

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

    1994-06-14

    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.

  6. Variable frequency microwave furnace system

    DOE Patents [OSTI]

    Bible, Don W.; Lauf, Robert J.

    1994-01-01

    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).

  7. Application of Maximum Likelihood Bayesian Model Averaging to Groundwater Flow and Transport at the Hanford Site 300 Area

    SciTech Connect (OSTI)

    Meyer, Philip D.; Ye, Ming; Neuman, Shlomo P.; Rockhold, Mark L.

    2008-06-01

    A methodology to systematically and quantitatively assess model predictive uncertainty was applied to saturated zone uranium transport at the 300 Area of the U.S. Department of Energy Hanford Site in Washington State, USA. The methodology extends Maximum Likelihood Bayesian Model Averaging (MLBMA) to account jointly for uncertainties due to the conceptual-mathematical basis of models, model parameters, and the scenarios to which the models are applied. Conceptual uncertainty was represented by postulating four alternative models of hydrogeology and uranium adsorption. Parameter uncertainties were represented by estimation covariances resulting from the joint calibration of each model to observed heads and uranium concentration. Posterior model probability was dominated by one model. Results demonstrated the role of model complexity and fidelity to observed system behavior in determining model probabilities, as well as the impact of prior information. Two scenarios representing alternative future behavior of the Columbia River adjacent to the site were considered. Predictive simulations carried out with the calibrated models illustrated the computation of model- and scenario-averaged predictions and how results can be displayed to clearly indicate the individual contributions to predictive uncertainty of the model, parameter, and scenario uncertainties. The application demonstrated the practicability of applying a comprehensive uncertainty assessment to large-scale, detailed groundwater flow and transport modelling.

  8. Three dimensional winds: A maximum cross-correlation application to elastic lidar data

    SciTech Connect (OSTI)

    Buttler, W.T.

    1996-05-01

    Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar (light detection and ranging) data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three-dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain-following winds in the Rio Grande valley.

  9. Enhancement of maximum attainable ion energy in the radiation pressure acceleration regime using a guiding structure

    SciTech Connect (OSTI)

    Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.

    2015-03-13

    Radiation Pressure Acceleration is a highly efficient mechanism of laser driven ion acceleration, with the laser energy almost totally transferrable to the ions in the relativistic regime. There is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. In the case of a tightly focused laser pulses, which are utilized to get the highest intensity, another factor limiting the maximum ion energy comes into play, the transverse expansion of the target. Transverse expansion makes the target transparent for radiation, thus reducing the effectiveness of acceleration. Utilization of an external guiding structure for the accelerating laser pulse may provide a way of compensating for the group velocity and transverse expansion effects.

  10. Enhancement of maximum attainable ion energy in the radiation pressure acceleration regime using a guiding structure

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bulanov, S. S.; Esarey, E.; Schroeder, C. B.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Pegoraro, F.; Leemans, W. P.

    2015-03-13

    Radiation Pressure Acceleration is a highly efficient mechanism of laser driven ion acceleration, with the laser energy almost totally transferrable to the ions in the relativistic regime. There is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. In the case of a tightly focused laser pulses, which are utilized to get the highest intensity, another factor limiting the maximum ion energy comes into play, the transverse expansion of the target. Transverse expansion makes the target transparent for radiation, thus reducing the effectiveness of acceleration. Utilization of an external guidingmore » structure for the accelerating laser pulse may provide a way of compensating for the group velocity and transverse expansion effects.« less

  11. Dynamic Programming and Error Estimates for Stochastic Control Problems with Maximum Cost

    SciTech Connect (OSTI)

    Bokanowski, Olivier; Picarelli, Athena; Zidani, Hasnaa

    2015-02-15

    This work is concerned with stochastic optimal control for a running maximum cost. A direct approach based on dynamic programming techniques is studied leading to the characterization of the value function as the unique viscosity solution of a second order Hamilton–Jacobi–Bellman (HJB) equation with an oblique derivative boundary condition. A general numerical scheme is proposed and a convergence result is provided. Error estimates are obtained for the semi-Lagrangian scheme. These results can apply to the case of lookback options in finance. Moreover, optimal control problems with maximum cost arise in the characterization of the reachable sets for a system of controlled stochastic differential equations. Some numerical simulations on examples of reachable analysis are included to illustrate our approach.

  12. Evaluation of Maximum Radionuclide Groundwater Concentrations for Basement Fill Model. Zion Station Restoration Project

    SciTech Connect (OSTI)

    Sullivan, Terry

    2014-12-02

    ZionSolutions is in the process of decommissioning the Zion Nuclear Power Plant in order to establish a new water treatment plant. There is some residual radioactive particles from the plant which need to be brought down to levels so an individual who receives water from the new treatment plant does not receive a radioactive dose in excess of 25 mrem/y⁻¹. The objectives of this report are: (a) To present a simplified conceptual model for release from the buildings with residual subsurface structures that can be used to provide an upper bound on contaminant concentrations in the fill material; (b) Provide maximum water concentrations and the corresponding amount of mass sorbed to the solid fill material that could occur in each building for use in dose assessment calculations; (c) Estimate the maximum concentration in a well located outside of the fill material; and (d) Perform a sensitivity analysis of key parameters.

  13. U.S. Lower 48 States Onshore Maximum Number of Active Crews Engaged in

    Gasoline and Diesel Fuel Update (EIA)

    Seismic Surveying (Number of Elements) Onshore Maximum Number of Active Crews Engaged in Seismic Surveying (Number of Elements) U.S. Lower 48 States Onshore 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 41 41 38 43 44 45 43 46 46 48 2001 44 45 45 47 45 42 42 41 39 39 42 41 2002 38 40 35 32 32 32 34 33 37 38 35 31 2003 28 29 28 27 24 25 28 30 30 31 31 32 2004 33 35 35 36 35 39 38 39 40 42 42 41

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

    Gasoline and Diesel Fuel Update (EIA)

    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

  15. Alaska Maximum Number of Active Crews Engaged in Seismic Surveying (Number

    Gasoline and Diesel Fuel Update (EIA)

    of Elements) Seismic Surveying (Number of Elements) Alaska 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 2 3 3 3 1 1 0 0 0 0 2001 0 0 0 0 2 2 0 0 0 0 0 0 2002 2 2 2 2 2 2 2 2 2 2 2 1 2003 0 0 2 2 2 2 2 2

  16. Direct tests of micro channel plates as the active element of a new shower maximum detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ronzhin, A.; Los, S.; Ramberg, E.; Apresyan, A.; Xie, S.; Spiropulu, M.; Kim, H.

    2015-05-22

    We continue the study of micro channel plates (MCP) as the active element of a shower maximum (SM) detector. We present below test beam results obtained with MCPs detecting directly secondary particles of an electromagnetic shower. The MCP efficiency to shower particles is close to 100%. In conclusion, the time resolution obtained for this new type of the SM detector is at the level of 40 ps.

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

    SciTech Connect (OSTI)

    Barletti, Luigi

    2014-08-15

    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.

  18. Direct tests of micro channel plates as the active element of a new shower maximum detector

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ronzhin, A.; Los, S.; Ramberg, E.; Apresyan, A.; Xie, S.; Spiropulu, M.; Kim, H.

    2015-05-22

    We continue the study of micro channel plates (MCP) as the active element of a shower maximum (SM) detector. We present below test beam results obtained with MCPs detecting directly secondary particles of an electromagnetic shower. The MCP efficiency to shower particles is close to 100%. Furthermore, the time resolution obtained for this new type of the SM detector is at the level of 40 ps.

  19. A new look at maximum and minimum temperature trends for the globe

    SciTech Connect (OSTI)

    Easterling, D.R.; Peterson, T.C.; Karl, T.R.

    1997-11-01

    A number of recent studies have established that differential changes in daily maximum and minimum temperatures are occurring, resulting in changes in the diurnal temperature range (DTR) for many parts of the globe. Large-scale trends in the USA indicate that minimum temperatures are increasing at a faster rate than maximum temperatures, resulting in a narrowing in the DTR. This paper updates and extends the analysis of changes in the DTR in three ways: (1) by increasing the areal coverage to more than half the global landmass, (2) by addressing the issue of homogeneity of the data, and (3) by examining the potential effects of urban stations on the calculated trends. The update includes data for an additional 15% of the global land area and an extension of the analysis period used in a previous study. Homogeneity techniques were used on the data to adjust individual station data for undocumented discontinuities. Annual maximum and minimum temperature and DTR time series for the 1950-1993 period averaged over 54% of the total global land area are presented. The trend for the maximum temperature is 0.88 C/100 years, which is consistent with earlier findings. However, the trend for the minimum temperature is 1.86 C/100 years; this is less than found in previous analyses and leads to a smaller trend in the DTR. This finding is not surprising since much of the data added in this study are for tropical and sub-tropical regions where temperature trends are not expected to be as large as in higher latitude regions. The effect of urbanization on the global trends is found to be on the order of 0.1 C/100 years or less, which is consistent with previous investigations. 14 refs., 2 figs.

  20. On Parallel Push-Relabel based Algorithms for Bipartite Maximum Matching

    SciTech Connect (OSTI)

    Langguth, Johannes; Azad, Md Ariful; Halappanavar, Mahantesh; Manne, Fredrik

    2014-07-01

    We study multithreaded push-relabel based algorithms for computing maximum cardinality matching in bipartite graphs. Matching is a fundamental combinatorial (graph) problem with applications in a wide variety of problems in science and engineering. We are motivated by its use in the context of sparse linear solvers for computing maximum transversal of a matrix. We implement and test our algorithms on several multi-socket multicore systems and compare their performance to state-of-the-art augmenting path-based serial and parallel algorithms using a testset comprised of a wide range of real-world instances. Building on several heuristics for enhancing performance, we demonstrate good scaling for the parallel push-relabel algorithm. We show that it is comparable to the best augmenting path-based algorithms for bipartite matching. To the best of our knowledge, this is the first extensive study of multithreaded push-relabel based algorithms. In addition to a direct impact on the applications using matching, the proposed algorithmic techniques can be extended to preflow-push based algorithms for computing maximum flow in graphs.

  1. Evaluation of Longitudinal Variabler in Relativistic Accelerators

    Energy Science and Technology Software Center (OSTI)

    1995-07-13

    ELVIRA is an encoding of an analytical formula to the calculation of longitudinal dynamics variable evolution during an accelerator ramp.

  2. Variable residence time vortex combustor

    DOE Patents [OSTI]

    Melconian, Jerry O.

    1987-01-01

    A variable residence time vortex combustor including a primary combustion chamber for containing a combustion vortex, and a plurality of louvres peripherally disposed about the primary combustion chamber and longitudinally distributed along its primary axis. The louvres are inclined to impel air about the primary combustion chamber to cool its interior surfaces and to impel air inwardly to assist in driving the combustion vortex in a first rotational direction and to feed combustion in the primary combustion chamber. The vortex combustor also includes a second combustion chamber having a secondary zone and a narrowed waist region in the primary combustion chamber interconnecting the output of the primary combustion chamber with the secondary zone for passing only lower density particles and trapping higher density particles in the combustion vortex in the primary combustion chamber for substantial combustion.

  3. Continuously variable focal length lens

    DOE Patents [OSTI]

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  4. Variable ratio regenerative braking device

    DOE Patents [OSTI]

    Hoppie, Lyle O.

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  5. Variable delivery, fixed displacement pump

    DOE Patents [OSTI]

    Sommars, Mark F.

    2001-01-01

    A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

  6. AUTOMATIC CLASSIFICATION OF VARIABLE STARS IN CATALOGS WITH MISSING DATA

    SciTech Connect (OSTI)

    Pichara, Karim; Protopapas, Pavlos

    2013-11-10

    We present an automatic classification method for astronomical catalogs with missing data. We use Bayesian networks and a probabilistic graphical model that allows us to perform inference to predict missing values given observed data and dependency relationships between variables. To learn a Bayesian network from incomplete data, we use an iterative algorithm that utilizes sampling methods and expectation maximization to estimate the distributions and probabilistic dependencies of variables from data with missing values. To test our model, we use three catalogs with missing data (SAGE, Two Micron All Sky Survey, and UBVI) and one complete catalog (MACHO). We examine how classification accuracy changes when information from missing data catalogs is included, how our method compares to traditional missing data approaches, and at what computational cost. Integrating these catalogs with missing data, we find that classification of variable objects improves by a few percent and by 15% for quasar detection while keeping the computational cost the same.

  7. Keeping the lights on for global ocean salinity observation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Durack, Paul J.; Lee, Tong; Vinogradova, Nadya T.; Stammer, Detlef

    2016-02-24

    Here, insights about climate are being uncovered thanks to improved capacities to observe ocean salinity, an essential climate variable. However, cracks are beginning to appear in the ocean observing system that require prompt attention if we are to maintain the existing, hard-won capacity into the near future.

  8. Deconvolving X-ray spectral variability components in the Seyfert 1.5 NGC 3227

    SciTech Connect (OSTI)

    Arvalo, P.; Markowitz, A.

    2014-03-10

    We present the variability analysis of a 100 ks XMM-Newton observation of the Seyfert 1.5 active galaxy, NGC 3227. The observation found NGC 3227 in a period where its hard power-law component displayed remarkably little long-term variability. This lucky event allows us to clearly observe a soft spectral component undergoing a large-amplitude but slow flux variation. Using combined spectral and timing analysis, we isolate two independent variable continuum components and characterize their behavior as a function of timescale. Rapid and coherent variations throughout the 0.2-10 keV band reveal a spectrally hard (photon index ? ? 1.7-1.8) power law, dominating the observed variability on timescales of 30 ks and shorter. Another component produces coherent fluctuations in the 0.2-2 keV range and is much softer (? ? 3); it dominates the observed variability on timescales greater than 30 ks. Both components are viewed through the same absorbers identified in the time-averaged spectrum. The combined spectral and timing analysis breaks the degeneracy between models for the soft excess: it is consistent with a power-law or thermal Comptonized component but not with a blackbody or an ionized reflection component. We demonstrate that the rapid variability in NGC 3227 is intrinsic to continuum-emitting components and is not an effect of variable absorption.

  9. Computational and human observer image quality evaluation of low dose, knowledge-based CT iterative reconstruction

    SciTech Connect (OSTI)

    Eck, Brendan L.; Fahmi, Rachid; Miao, Jun; Brown, Kevin M.; Zabic, Stanislav; Raihani, Nilgoun; Wilson, David L.

    2015-10-15

    Purpose: Aims in this study are to (1) develop a computational model observer which reliably tracks the detectability of human observers in low dose computed tomography (CT) images reconstructed with knowledge-based iterative reconstruction (IMR™, Philips Healthcare) and filtered back projection (FBP) across a range of independent variables, (2) use the model to evaluate detectability trends across reconstructions and make predictions of human observer detectability, and (3) perform human observer studies based on model predictions to demonstrate applications of the model in CT imaging. Methods: Detectability (d′) was evaluated in phantom studies across a range of conditions. Images were generated using a numerical CT simulator. Trained observers performed 4-alternative forced choice (4-AFC) experiments across dose (1.3, 2.7, 4.0 mGy), pin size (4, 6, 8 mm), contrast (0.3%, 0.5%, 1.0%), and reconstruction (FBP, IMR), at fixed display window. A five-channel Laguerre–Gauss channelized Hotelling observer (CHO) was developed with internal noise added to the decision variable and/or to channel outputs, creating six different internal noise models. Semianalytic internal noise computation was tested against Monte Carlo and used to accelerate internal noise parameter optimization. Model parameters were estimated from all experiments at once using maximum likelihood on the probability correct, P{sub C}. Akaike information criterion (AIC) was used to compare models of different orders. The best model was selected according to AIC and used to predict detectability in blended FBP-IMR images, analyze trends in IMR detectability improvements, and predict dose savings with IMR. Predicted dose savings were compared against 4-AFC study results using physical CT phantom images. Results: Detection in IMR was greater than FBP in all tested conditions. The CHO with internal noise proportional to channel output standard deviations, Model-k4, showed the best trade-off between fit

  10. Free kick instead of cross-validation in maximum-likelihood refinement of macromolecular crystal structures

    SciTech Connect (OSTI)

    Pranikar, Jure [Institute Joef Stefan, Jamova 39, 1000 Ljubljana (Slovenia); University of Primorska, (Slovenia); Turk, Duan, E-mail: dusan.turk@ijs.si [Institute Joef Stefan, Jamova 39, 1000 Ljubljana (Slovenia); Center of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, (Slovenia)

    2014-12-01

    The maximum-likelihood free-kick target, which calculates model error estimates from the work set and a randomly displaced model, proved superior in the accuracy and consistency of refinement of crystal structures compared with the maximum-likelihood cross-validation target, which calculates error estimates from the test set and the unperturbed model. The refinement of a molecular model is a computational procedure by which the atomic model is fitted to the diffraction data. The commonly used target in the refinement of macromolecular structures is the maximum-likelihood (ML) function, which relies on the assessment of model errors. The current ML functions rely on cross-validation. They utilize phase-error estimates that are calculated from a small fraction of diffraction data, called the test set, that are not used to fit the model. An approach has been developed that uses the work set to calculate the phase-error estimates in the ML refinement from simulating the model errors via the random displacement of atomic coordinates. It is called ML free-kick refinement as it uses the ML formulation of the target function and is based on the idea of freeing the model from the model bias imposed by the chemical energy restraints used in refinement. This approach for the calculation of error estimates is superior to the cross-validation approach: it reduces the phase error and increases the accuracy of molecular models, is more robust, provides clearer maps and may use a smaller portion of data for the test set for the calculation of R{sub free} or may leave it out completely.

  11. A New Maximum-Likelihood Change Estimator for Two-Pass SAR Coherent Change Detection.

    SciTech Connect (OSTI)

    Wahl, Daniel E.; Yocky, David A.; Jakowatz, Charles V,

    2014-09-01

    In this paper, we derive a new optimal change metric to be used in synthetic aperture RADAR (SAR) coherent change detection (CCD). Previous CCD methods tend to produce false alarm states (showing change when there is none) in areas of the image that have a low clutter-to-noise power ratio (CNR). The new estimator does not suffer from this shortcoming. It is a surprisingly simple expression, easy to implement, and is optimal in the maximum-likelihood (ML) sense. The estimator produces very impressive results on the CCD collects that we have tested.

  12. Variable path length spectrophotometric probe

    DOE Patents [OSTI]

    O'Rourke, Patrick E.; McCarty, Jerry E.; Haggard, Ricky A.

    1992-01-01

    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.

  13. (Solar variability observed through changes in solar limb-darkening function and mean diameter)

    SciTech Connect (OSTI)

    Hill, H.A.

    1991-01-01

    This report discusses: long-term changes in the apparent solar diameter/limb-darkening functions; work on solar gravity modes; and development on inverse techniques.

  14. IMPROVED VARIABLE STAR SEARCH IN LARGE PHOTOMETRIC DATA SETS: NEW VARIABLES IN CoRoT FIELD LRa02 DETECTED BY BEST II

    SciTech Connect (OSTI)

    Fruth, T.; Cabrera, J.; Csizmadia, Sz.; Eigmueller, P.; Erikson, A.; Kirste, S.; Pasternacki, T.; Rauer, H.; Titz-Weider, R.; Kabath, P.; Chini, R.; Lemke, R.; Murphy, M.

    2012-06-15

    The CoRoT field LRa02 has been observed with the Berlin Exoplanet Search Telescope II (BEST II) during the southern summer 2007/2008. A first analysis of stellar variability led to the publication of 345 newly discovered variable stars. Now, a deeper analysis of this data set was used to optimize the variability search procedure. Several methods and parameters have been tested in order to improve the selection process compared to the widely used J index for variability ranking. This paper describes an empirical approach to treat systematic trends in photometric data based upon the analysis of variance statistics that can significantly decrease the rate of false detections. Finally, the process of reanalysis and method improvement has virtually doubled the number of variable stars compared to the first analysis by Kabath et al. A supplementary catalog of 272 previously unknown periodic variables plus 52 stars with suspected variability is presented. Improved ephemerides are given for 19 known variables in the field. In addition, the BEST II results are compared with CoRoT data and its automatic variability classification.

  15. Eccentric crank variable compression ratio mechanism

    DOE Patents [OSTI]

    Lawrence, Keith Edward; Moser, William Elliott; Roozenboom, Stephan Donald; Knox, Kevin Jay

    2008-05-13

    A variable compression ratio mechanism for an internal combustion engine that has an engine block and a crankshaft is disclosed. The variable compression ratio mechanism has a plurality of eccentric disks configured to support the crankshaft. Each of the plurality of eccentric disks has at least one cylindrical portion annularly surrounded by the engine block. The variable compression ratio mechanism also has at least one actuator configured to rotate the plurality of eccentric disks.

  16. Variables Affecting Economic Development of Wind Energy

    SciTech Connect (OSTI)

    Lantz, E.; Tegen, S.

    2008-02-01

    Report on the specific factors driving wind-power-related economic development and on the impact of specific economic development variables on new wind project economic benefits.

  17. Variable-Period Undulators For Synchrotron Radiation

    DOE Patents [OSTI]

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

    2005-02-22

    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.

  18. WIND VARIABILITY IN BZ CAMELOPARDALIS

    SciTech Connect (OSTI)

    Honeycutt, R. K.; Kafka, S.; Robertson, J. W. E-mail: skafka@dtm.ciw.edu

    2013-02-01

    Sequences of spectra of the nova-like cataclysmic variable (CV) BZ Cam were acquired on nine nights in 2005-2006 in order to study the time development of episodes of wind activity known to occur frequently in this star. We confirm the results of Ringwald and Naylor that the P-Cygni absorption components of the lines mostly evolve from higher expansion velocity to lower velocity as an episode progresses. We also commonly find blueshifted emission components in the H{alpha} line profile, whose velocities and durations strongly suggest that they are also due to the wind. Curiously, Ringwald and Naylor reported common occurrences of redshifted H{alpha} emission components in their BZ Cam spectra. We have attributed these emission components in H{alpha} to occasions when gas concentrations in the bipolar wind (both front side and back side) become manifested as emission lines as they move beyond the disk's outer edge. We also suggest, based on changes in the P-Cygni profiles during an episode, that the progression from larger to smaller expansion velocities is due to the higher velocity portions of a wind concentration moving beyond the edge of the continuum light of the disk first, leaving a net redward shift of the remaining absorption profile. We derive a new orbital ephemeris for BZ Cam, using the radial velocity of the core of the He I {lambda}5876 line, finding P = 0.15353(4). Using this period, the wind episodes in BZ Cam are found to be concentrated near the inferior conjunction of the emission line source. This result helps confirm that the winds in nova-like CVs are often phase dependent, in spite of the puzzling implication that such winds lack axisymmetry. We argue that the radiation-driven wind in BZ Cam receives an initial boost by acting on gas that has been lifted above the disk by the interaction of the accretion stream with the disk, thereby imposing flickering timescales onto the wind events, as well as leading to an orbital modulation of the wind

  19. Safety Observations Achieve Results

    Energy Science and Technology Software Center (OSTI)

    2000-01-16

    The SOAR web application provides a multi-checklist capability where focused observations can be created to address risk-likely work environments, tasks, etc. The SOAR web application has numerous reports to sort the data by key word, multiple factors (i.e., location, team, behavior, checklist, work environment, etc.), and the highest frequency of behaviors and error-likely predecessors, etc. Other performance indicators are also provided.

  20. Earth System Observations

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

    4 Earth System Observations Research comprises Earth, ocean, and atmospheric sciences to better understand and predict climate change's impact on ecosystems and to study subsurface geological materials and their interactions. Deploying research facilities globally Forecasting forests' responses to climate change Monitoring terrestrial ecosystems Contact Us Group Leader Claudia Mora Email Deputy Group Leader Bob Roback Email Profile pages header Search our Profile pages Investigating carbon

  1. Application of Markov chain model to daily maximum temperature for thermal comfort in Malaysia

    SciTech Connect (OSTI)

    Nordin, Muhamad Asyraf bin Che; Hassan, Husna

    2015-10-22

    The Markov chain’s first order principle has been widely used to model various meteorological fields, for prediction purposes. In this study, a 14-year (2000-2013) data of daily maximum temperatures in Bayan Lepas were used. Earlier studies showed that the outdoor thermal comfort range based on physiologically equivalent temperature (PET) index in Malaysia is less than 34°C, thus the data obtained were classified into two state: normal state (within thermal comfort range) and hot state (above thermal comfort range). The long-run results show the probability of daily temperature exceed TCR will be only 2.2%. On the other hand, the probability daily temperature within TCR will be 97.8%.

  2. A Distributed Approach to Maximum Power Point Tracking for Photovoltaic Submodule Differential Power Processing

    SciTech Connect (OSTI)

    Qin, SB; Cady, ST; Dominguez-Garcia, AD; Pilawa-Podgurski, RCN

    2015-04-01

    This paper presents the theory and implementation of a distributed algorithm for controlling differential power processing converters in photovoltaic (PV) applications. This distributed algorithm achieves true maximum power point tracking of series-connected PV submodules by relying only on local voltage measurements and neighbor-to-neighbor communication between the differential power converters. Compared to previous solutions, the proposed algorithm achieves reduced number of perturbations at each step and potentially faster tracking without adding extra hardware; all these features make this algorithm well-suited for long submodule strings. The formulation of the algorithm, discussion of its properties, as well as three case studies are presented. The performance of the distributed tracking algorithm has been verified via experiments, which yielded quantifiable improvements over other techniques that have been implemented in practice. Both simulations and hardware experiments have confirmed the effectiveness of the proposed distributed algorithm.

  3. Dithering Digital Ripple Correlation Control for Photovoltaic Maximum Power Point Tracking

    SciTech Connect (OSTI)

    Barth, C; Pilawa-Podgurski, RCN

    2015-08-01

    This study demonstrates a new method for rapid and precise maximum power point tracking in photovoltaic (PV) applications using dithered PWM control. Constraints imposed by efficiency, cost, and component size limit the available PWM resolution of a power converter, and may in turn limit the MPP tracking efficiency of the PV system. In these scenarios, PWM dithering can be used to improve average PWM resolution. In this study, we present a control technique that uses ripple correlation control (RCC) on the dithering ripple, thereby achieving simultaneous fast tracking speed and high tracking accuracy. Moreover, the proposed method solves some of the practical challenges that have to date limited the effectiveness of RCC in solar PV applications. We present a theoretical derivation of the principles behind dithering digital ripple correlation control, as well as experimental results that show excellent tracking speed and accuracy with basic hardware requirements.

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

    Reports and Publications (EIA)

    2005-01-01

    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.

  5. A new maximum-likelihood change estimator for two-pass SAR coherent change detection

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wahl, Daniel E.; Yocky, David A.; Jakowatz, Jr., Charles V.; Simonson, Katherine Mary

    2016-01-11

    In past research, two-pass repeat-geometry synthetic aperture radar (SAR) coherent change detection (CCD) predominantly utilized the sample degree of coherence as a measure of the temporal change occurring between two complex-valued image collects. Previous coherence-based CCD approaches tend to show temporal change when there is none in areas of the image that have a low clutter-to-noise power ratio. Instead of employing the sample coherence magnitude as a change metric, in this paper, we derive a new maximum-likelihood (ML) temporal change estimate—the complex reflectance change detection (CRCD) metric to be used for SAR coherent temporal change detection. The new CRCD estimatormore » is a surprisingly simple expression, easy to implement, and optimal in the ML sense. As a result, this new estimate produces improved results in the coherent pair collects that we have tested.« less

  6. U.S.Lower 48 States Offshore Maximum Number of Active Crews Engaged in

    Gasoline and Diesel Fuel Update (EIA)

    Three-Dimensional Seismic Surveying (Number of Elements) Three-Dimensional Seismic Surveying (Number of Elements) U.S.Lower 48 States Offshore Maximum Number of Active Crews Engaged in Three-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2000 0 0 11 11 11 9 6 7 8 9 8 8 2001 7 7 9 9 8 7 8 8 9 10 10 9 2002 6 6 7 7 8 7 8 7 7 7 5 4 2003 4 4 4 4 4 4 4 4 2 3 3 5 2004 5 5 5 4 4 4 4 4 2 2 4 4 2005 4 4 6 6 6 5 5 5 5 5 5 5 2006 5 6 6 6 6 5 5 5 5

  7. U.S.Lower 48 States Offshore Maximum Number of Active Crews Engaged in

    Gasoline and Diesel Fuel Update (EIA)

    Two-Dimensional Seismic Surveying (Number of Elements) Two-Dimensional Seismic Surveying (Number of Elements) U.S.Lower 48 States Offshore Maximum Number of Active Crews Engaged in Two-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2000 0 0 7 7 6 7 6 7 7 7 7 8 2001 9 8 9 9 9 9 8 7 6 9 7 8 2002 8 9 10 9 9 9 8 8 10 10 8 7 2003 8 8 7 7 8 8 7 7 7 5 4 5 2004 5 5 5 5 5 4 4 4 4 2 1 3 2005 5 5 6 6 7 7 6 6 6 6 6 6 2006 6 6 6 5 5 7 4 3 2 2 3 3

  8. U.S.Lower 48 States Onshore Maximum Number of Active Crews Engaged in

    Gasoline and Diesel Fuel Update (EIA)

    Four-Dimensional Seismic Surveying (Number of Elements) Four-Dimensional Seismic Surveying (Number of Elements) U.S.Lower 48 States Onshore Maximum Number of Active Crews Engaged in Four-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2000 0 0 1 1 1 1 1 1 1 1 1 1 2001 1 1 1 1 1 1 1 1 1 1 1 1 2002 0 0 0 0 0 0 0 0 0 0 0 0 2003 1 0 0 0 0 0 0 0 0 0 0 0 2004 0 0 0 0 0 0 0 0 0 0 0 0 2005 0 0 0 0 0 0 0 0 0 0 0 0 2006 0 0 0 0 0 0 0 0 0 0 0 0

  9. U.S.Lower 48 States Onshore Maximum Number of Active Crews Engaged in

    Gasoline and Diesel Fuel Update (EIA)

    Three-Dimensional Seismic Surveying (Number of Elements) Three-Dimensional Seismic Surveying (Number of Elements) U.S.Lower 48 States Onshore Maximum Number of Active Crews Engaged in Three-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2000 0 0 36 36 34 37 39 40 39 41 40 41 2001 38 38 38 39 37 35 35 32 30 33 34 33 2002 32 31 26 25 24 23 26 26 28 30 27 22 2003 19 20 20 20 17 18 21 22 22 24 24 25 2004 25 27 27 27 26 30 30 31 32 34 33 32

  10. U.S.Lower 48 States Onshore Maximum Number of Active Crews Engaged in

    Gasoline and Diesel Fuel Update (EIA)

    Two-Dimensional Seismic Surveying (Number of Elements) Two-Dimensional Seismic Surveying (Number of Elements) U.S.Lower 48 States Onshore Maximum Number of Active Crews Engaged in Two-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 2000 0 0 4 4 3 5 4 4 3 4 4 5 2001 5 6 6 7 7 6 6 8 8 5 7 7 2002 6 9 9 7 8 9 8 7 9 8 8 8 2003 8 9 8 7 7 7 7 8 8 7 7 7 2004 8 8 8 9 9 9 8 8 8 8 9 9 2005 8 8 6 8 8 9 8 8 7 6 5 6 2006 5 5 4 4 4 9 5 4 4 5 5 5 2007

  11. Thirty-Year Solid Waste Generation Maximum and Minimum Forecast for SRS

    SciTech Connect (OSTI)

    Thomas, L.C.

    1994-10-01

    This report is the third phase (Phase III) of the Thirty-Year Solid Waste Generation Forecast for Facilities at the Savannah River Site (SRS). Phase I of the forecast, Thirty-Year Solid Waste Generation Forecast for Facilities at SRS, forecasts the yearly quantities of low-level waste (LLW), hazardous waste, mixed waste, and transuranic (TRU) wastes generated over the next 30 years by operations, decontamination and decommissioning and environmental restoration (ER) activities at the Savannah River Site. The Phase II report, Thirty-Year Solid Waste Generation Forecast by Treatability Group (U), provides a 30-year forecast by waste treatability group for operations, decontamination and decommissioning, and ER activities. In addition, a 30-year forecast by waste stream has been provided for operations in Appendix A of the Phase II report. The solid wastes stored or generated at SRS must be treated and disposed of in accordance with federal, state, and local laws and regulations. To evaluate, select, and justify the use of promising treatment technologies and to evaluate the potential impact to the environment, the generic waste categories described in the Phase I report were divided into smaller classifications with similar physical, chemical, and radiological characteristics. These smaller classifications, defined within the Phase II report as treatability groups, can then be used in the Waste Management Environmental Impact Statement process to evaluate treatment options. The waste generation forecasts in the Phase II report includes existing waste inventories. Existing waste inventories, which include waste streams from continuing operations and stored wastes from discontinued operations, were not included in the Phase I report. Maximum and minimum forecasts serve as upper and lower boundaries for waste generation. This report provides the maximum and minimum forecast by waste treatability group for operation, decontamination and decommissioning, and ER activities.

  12. Variable orifice using an iris shutter

    DOE Patents [OSTI]

    Beeman, Raymond; Brajkovich, Steven J.

    1978-01-01

    A variable orifice forming mechanism utilizing an iris shutter arrangement adapted to control gas flow, conductance in vacuum systems, as a heat shield for furnace windows, as a beam shutter in sputtering operations, and in any other application requiring periodic or continuously-variable control of material, gas, or fluid flow.

  13. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

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

    1995-08-08

    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.

  14. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

    Bogaty, John M.; Clifft, Benny E.; Bollinger, Lowell M.

    1995-01-01

    A beam current limiter 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.

  15. Ozone and other air quality related variables affecting visibility in the southeast United States. Master`s thesis

    SciTech Connect (OSTI)

    Brittig, J.S.

    1997-07-11

    An analysis of ozone (03) concentrations and several other air quality related variables was performed to assess their relationship with visibility at five urban and semi-urban locations in the Southeast United States during the summer seasons of 1980 to 1996. The role and impact of ozone on aerosols was investigated to ascertain a relationship with visibility. Regional trend analysis of the 1980s reveals an increase in maximum ozone concentration coupled with a decrease in visibility. However, the 1990s shows a leveling off of both ozone and visibility; in both cases the results were not statistically significant at the 5% level. Site specific trends at Nashville Tennessee followed similar trends. To better ascertain the relationships and forcing mechanisms, the analysis was changed from yearly to daily and hourly averaged values. This increased resolution showed a statistically significant inverse relationship between visibility and ozone. Additionally, by performing back trajectory analysis, it was observed that the visibility degraded both by airmass migration over polluted areas and chemical kinetics.

  16. Variability in Automated Responses of Commercial Buildings and Industrial Facilities to Dynamic Electricity Prices

    SciTech Connect (OSTI)

    Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

    2011-08-16

    Changes in the electricity consumption of commercial buildings and industrial facilities (C&I facilities) during Demand Response (DR) events are usually estimated using counterfactual baseline models. Model error makes it difficult to precisely quantify these changes in consumption and understand if C&I facilities exhibit event-to-event variability in their response to DR signals. This paper seeks to understand baseline model error and DR variability in C&I facilities facing dynamic electricity prices. Using a regression-based baseline model, we present a method to compute the error associated with estimates of several DR parameters. We also develop a metric to determine how much observed DR variability results from baseline model error rather than real variability in response. We analyze 38 C&I facilities participating in an automated DR program and find that DR parameter errors are large. Though some facilities exhibit real DR variability, most observed variability results from baseline model error. Therefore, facilities with variable DR parameters may actually respond consistently from event to event. Consequently, in DR programs in which repeatability is valued, individual buildings may be performing better than previously thought. In some cases, however, aggregations of C&I facilities exhibit real DR variability, which could create challenges for power system operation.

  17. Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing

    SciTech Connect (OSTI)

    Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

    2011-08-15

    Controlling electric loads to deliver power system services presents a number of interesting challenges. For example, changes in electricity consumption of Commercial and Industrial (C&I) facilities are usually estimated using counterfactual baseline models, and model uncertainty makes it difficult to precisely quantify control responsiveness. Moreover, C&I facilities exhibit variability in their response. This paper seeks to understand baseline model error and demand-side variability in responses to open-loop control signals (i.e. dynamic prices). Using a regression-based baseline model, we define several Demand Response (DR) parameters, which characterize changes in electricity use on DR days, and then present a method for computing the error associated with DR parameter estimates. In addition to analyzing the magnitude of DR parameter error, we develop a metric to determine how much observed DR parameter variability is attributable to real event-to-event variability versus simply baseline model error. Using data from 38 C&I facilities that participated in an automated DR program in California, we find that DR parameter errors are large. For most facilities, observed DR parameter variability is likely explained by baseline model error, not real DR parameter variability; however, a number of facilities exhibit real DR parameter variability. In some cases, the aggregate population of C&I facilities exhibits real DR parameter variability, resulting in implications for the system operator with respect to both resource planning and system stability.

  18. HCCI in a Variable Compression Ratio Engine: Effects of Engine Variables |

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

    Department of Energy in a Variable Compression Ratio Engine: Effects of Engine Variables HCCI in a Variable Compression Ratio Engine: Effects of Engine Variables 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: Southwest Research Institute 2004_deer_ryan.pdf (410.71 KB) More Documents & Publications HCCI - A Technical Review and Progress Report 2006 HCCI - Update of Progress 2005 Fuel Requirements for HCCI Engine Operation

  19. Initial results from NuSTAR observations of the Norma Arm

    SciTech Connect (OSTI)

    Bodaghee, Arash; Tomsick, John A.; Krivonos, Roman; Barrire, Nicolas; Boggs, Steven E.; Craig, William W.; Stern, Daniel; Bauer, Franz E.; Fornasini, Francesca M.; Christensen, Finn E.; Gotthelf, Eric V.; Hailey, Charles J.; Mori, Kaya; Harrison, Fiona A.; Hong, Jaesub; Zhang, William W.

    2014-08-10

    Results are presented for an initial survey of the Norma Arm gathered with the focusing hard X-Ray Telescope NuSTAR. The survey covers 0.2 deg{sup 2} of sky area in the 3-79 keV range with a minimum and maximum raw depth of 15 ks and 135 ks, respectively. Besides a bright black-hole X-ray binary in outburst (4U 163047) and a new X-ray transient (NuSTAR J163433473841), NuSTAR locates three sources from the Chandra survey of this region whose spectra are extended above 10 keV for the first time: CXOU J163329.5473332, CXOU J163350.9474638, and CXOU J163355.1473804. Imaging, timing, and spectral data from a broad X-ray range (0.3-79 keV) are analyzed and interpreted with the aim of classifying these objects. CXOU J163329.5473332 is either a cataclysmic variable or a faint low-mass X-ray binary. CXOU J163350.9474638 varies in intensity on year-long timescales, and with no multi-wavelength counterpart, it could be a distant X-ray binary or possibly a magnetar. CXOU J163355.1473804 features a helium-like iron line at 6.7 keV and is classified as a nearby cataclysmic variable. Additional surveys are planned for the Norma Arm and Galactic Center, and those NuSTAR observations will benefit from the lessons learned during this pilot study.

  20. ESTIMATE OF SOLAR MAXIMUM USING THE 1-8 GEOSTATIONARY OPERATIONAL ENVIRONMENTAL SATELLITES X-RAY MEASUREMENTS

    SciTech Connect (OSTI)

    Winter, L. M.; Balasubramaniam, K. S.

    2014-10-01

    We present an alternate method of determining the progression of the solar cycle through an analysis of the solar X-ray background. Our results are based on the NOAA Geostationary Operational Environmental Satellites (GOES) X-ray data in the 1-8 band from 1986 to the present, covering solar cycles 22, 23, and 24. The X-ray background level tracks the progression of the solar cycle through its maximum and minimum. Using the X-ray data, we can therefore make estimates of the solar cycle progression and the date of solar maximum. Based upon our analysis, we conclude that the Sun reached its hemisphere-averaged maximum in solar cycle 24 in late 2013. This is within six months of the NOAA prediction of a maximum in spring 2013.

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

    SciTech Connect (OSTI)

    Su-Jong Yoon; Piyush Sabharwall

    2014-07-01

    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.

  2. Evaluation of methods to predict safe welding conditions and maximum HAZ hardness in steel welding

    SciTech Connect (OSTI)

    Tronskar, J.P.

    1995-02-01

    During the last ten years new structural steels of improved weldability have been introduced. In particular, structural steels for the fabrication of offshore structures have been greatly improved in this respect throughout this period. These steels have lean chemical compositions which are generally outside the range for which the existing HAZ hardness criteria and the International Institute of Welding carbon equivalent (CEIIW) formula were originally developed. This paper presents the results from investigations of the weldability of three normalized (R{sub e} min 350 MPa) and three quenched and tempered (R{sub e} min 500 MPa) offshore structural steels. Weldability testing was conducted to study the relative performance of the different steels and to obtain a comparison between the capability of the different methods to predict safe welding conditions to avoid cold cracking in steel welding. It has become a widespread practice in welding high-strength steels to incorporate maximum HAZ hardness restrictions in fabrication specifications, particularly so in the offshore industry. This paper presents some of the more successful approaches proposed to date and compares their performance.

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

    SciTech Connect (OSTI)

    Bowyer, Ted W.; Kephart, Rosara F.; Eslinger, Paul W.; Friese, Judah I.; Miley, Harry S.; Saey, Paul R.

    2013-01-01

    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.

  4. Robust Maximum Lifetime Routing and Energy Allocation in Wireless Sensor Networks

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Paschalidis, Ioannis Ch.; Wu, Ruomin

    2012-01-01

    We consider the maximum lifetime routing problem in wireless sensor networks in two settings: (a) when nodes’ initial energy is given and (b) when it is subject to optimization. The optimal solution and objective value provide optimal flows and the corresponding predicted lifetime, respectively. We stipulate that there is uncertainty in various network parameters (available energy and energy depletion rates). In setting (a) we show that for specific, yet typical, network topologies, the actual network lifetime will reach the predicted value with a probability that converges to zero as the number of nodes grows large. In setting (b) the samemore » result holds for all topologies. We develop a series of robust problem formulations, ranging from pessimistic to optimistic. A set of parameters enable the tuning of the conservatism of the formulation to obtain network flows with a desirably high probability that the corresponding lifetime prediction is achieved. We establish a number of properties for the robust network flows and energy allocations and provide numerical results to highlight the tradeoff between predicted lifetime and the probability achieved. Further, we analyze an interesting limiting regime of massively deployed sensor networks and essentially solve a continuous version of the problem.« less

  5. Maximum Diameter Measurements of Aortic Aneurysms on Axial CT Images After Endovascular Aneurysm Repair: Sufficient for Follow-up?

    SciTech Connect (OSTI)

    Baumueller, Stephan Nguyen, Thi Dan Linh Goetti, Robert Paul; Lachat, Mario; Seifert, Burkhardt; Pfammatter, Thomas Frauenfelder, Thomas

    2011-12-15

    Purpose: To assess the accuracy of maximum diameter measurements of aortic aneurysms after endovascular aneurysm repair (EVAR) on axial computed tomographic (CT) images in comparison to maximum diameter measurements perpendicular to the intravascular centerline for follow-up by using three-dimensional (3D) volume measurements as the reference standard. Materials and Methods: Forty-nine consecutive patients (73 {+-} 7.5 years, range 51-88 years), who underwent EVAR of an infrarenal aortic aneurysm were retrospectively included. Two blinded readers twice independently measured the maximum aneurysm diameter on axial CT images performed at discharge, and at 1 and 2 years after intervention. The maximum diameter perpendicular to the centerline was automatically measured. Volumes of the aortic aneurysms were calculated by dedicated semiautomated 3D segmentation software (3surgery, 3mensio, the Netherlands). Changes in diameter of 0.5 cm and in volume of 10% were considered clinically significant. Intra- and interobserver agreements were calculated by intraclass correlations (ICC) in a random effects analysis of variance. The two unidimensional measurement methods were correlated to the reference standard. Results: Intra- and interobserver agreements for maximum aneurysm diameter measurements were excellent (ICC = 0.98 and ICC = 0.96, respectively). There was an excellent correlation between maximum aneurysm diameters measured on axial CT images and 3D volume measurements (r = 0.93, P < 0.001) as well as between maximum diameter measurements perpendicular to the centerline and 3D volume measurements (r = 0.93, P < 0.001). Conclusion: Measurements of maximum aneurysm diameters on axial CT images are an accurate, reliable, and robust method for follow-up after EVAR and can be used in daily routine.

  6. 2011-07 "Maximum Utilization of WIPP by Increasing MDA G TRU Shipments" |

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

    Department of Energy 7 "Maximum Utilization of WIPP by Increasing MDA G TRU Shipments" 2011-07 "Maximum Utilization of WIPP by Increasing MDA G TRU Shipments" The intent of this recommendation is to ensure optimization of WIPP shipment schedules while helping to keep commitments to Consent Order milestones at MDA-G. Rec 2011-07 - July 27, 2011 (78.0

  7. PV output variability modeling using satellite imagery.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Ellis, Abraham; Reno, Matthew J.

    2010-11-01

    High frequency irradiance variability measured on the ground is caused by the formation, dissipation, and passage of clouds in the sky. If we can identify and associate different cloud types/patterns from satellite imagery, we may be able to predict irradiance variability in areas lacking sensors. With satellite imagery covering the entire U.S., this allows for more accurate integration planning and power flow modeling over wide areas. Satellite imagery from southern Nevada was analyzed at 15 minute intervals over a year. Methods for image stabilization, cloud detection, and textural classification of clouds were developed and tested. High Performance Computing parallel processing algorithms were also investigated and tested. Artificial Neural Networks using imagery as inputs were trained on ground-based measurements of irradiance to model the variability and were tested to show some promise as a means for predicting irradiance variability.

  8. THE CATALINA SURVEYS PERIODIC VARIABLE STAR CATALOG

    SciTech Connect (OSTI)

    Drake, A. J.; Graham, M. J.; Djorgovski, S. G.; Mahabal, A. A.; Donalek, C.; Williams, R.; Catelan, M.; Torrealba, G.; García-Álvarez, D.; Prieto, J. L.; Beshore, E.; Larson, S.; Christen sen, E.; Boattini, A.; Gibbs, A.; Hill, R.; Kowalski, R.; Johnson, J.; Belokurov, V.; Koposov, S. E.; and others

    2014-07-01

    We present ∼47,000 periodic variables found during the analysis of 5.4 million variable star candidates within a 20,000 deg{sup 2} region covered by the Catalina Surveys Data Release-1 (CSDR1). Combining these variables with type ab RR Lyrae from our previous work, we produce an online catalog containing periods, amplitudes, and classifications for ∼61,000 periodic variables. By cross-matching these variables with those from prior surveys, we find that >90% of the ∼8000 known periodic variables in the survey region are recovered. For these sources, we find excellent agreement between our catalog and prior values of luminosity, period, and amplitude as well as classification. We investigate the rate of confusion between objects classified as contact binaries and type c RR Lyrae (RRc's) based on periods, colors, amplitudes, metallicities, radial velocities, and surface gravities. We find that no more than a few percent of the variables in these classes are misidentified. By deriving distances for this clean sample of ∼5500 RRc's, we trace the path of the Sagittarius tidal streams within the Galactic halo. Selecting 146 outer-halo RRc's with SDSS radial velocities, we confirm the presence of a coherent halo structure that is inconsistent with current N-body simulations of the Sagittarius tidal stream. We also find numerous long-period variables that are very likely associated within the Sagittarius tidal stream system. Based on the examination of 31,000 contact binary light curves we find evidence for two subgroups exhibiting irregular light curves. One subgroup presents significant variations in mean brightness that are likely due to chromospheric activity. The other subgroup shows stable modulations over more than a thousand days and thereby provides evidence that the O'Connell effect is not due to stellar spots.

  9. Characterizing Local High-Frequency Solar Variability

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

    Local High-Frequency Solar Variability and its Impact to Distribution Studies* Matthew Lave a,∗∗ , Matthew J. Reno b , Robert J. Broderick b a Sandia National Laboratories, 7011 East Avenue, Livermore, CA 94550, United States b Sandia National Laboratories, 1515 Eubank SE, Albuquerque, NM 87123, United States Abstract Accurately representing the local solar variability at timescales relevant to distribution grid operations (30-seconds and shorter) is essential to modeling the impact of solar

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

    SciTech Connect (OSTI)

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

    2012-02-17

    , 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.

  11. VariableR reclustering in multiple top quark events - Oral Presentation

    SciTech Connect (OSTI)

    Hyde, Jeremy; /SLAC

    2015-08-22

    VariableR jet reclustering is an innovative technique that allows for the reconstruction of boosted object over a wide range of kinematic regimes. Such capability enables the efficient identification of events with multiple boosted top quarks which is a typical signature for new physics processes such as the production of the supersymmetric partner of the gluon. In order to evaluate the performance of the algorithm, the VariableR reclustered jets are compared with fixed radius reclustered jets. The flexibility of the algorithm is tested by reconstructing both boosted top quarks and boosted W bosons. The VariableR reclustering method is found to be more efficient than the fixed radius algorithm at identifying top quarks and W bosons in events with four top quarks, therefore enhancing the sensitivity for gluino searches.

  12. VariableR Reclustering in Multiple Top Quark and W Boson Events

    SciTech Connect (OSTI)

    Hyde, Jeremy

    2015-08-14

    VariableR jet reclustering is an innovative technique that allows for the reconstruction of boosted object over a wide range of kinematic regimes. Such capability enables the efficient identification of events with multiple boosted top quarks which is a typical signature for new physics processes such as the production of the supersymmetric partner of the gluon. In order to evaluate the performance of the algorithm, the VariableR reclustered jets are compared with fixed radius reclustered jets. The flexibility of the algorithm is tested by reconstructing both boosted top quarks and boosted W bosons. The VariableR reclustering method is found to be more efficient than the fixed radius algorithm at identifying top quarks and W bosons in events with four top quarks, therefore enhancing the sensitivity for gluino searches.

  13. Interannual Modulation of Subtropical Atlantic Boreal Summer Dust Variability by ENSO

    SciTech Connect (OSTI)

    DeFlorio, Mike; Goodwin, Ian D.; Cayan, Dan; Miller, Arthur J.; Ghan, Steven J.; Pierce, David; Russell, Lynn M.; Singh, Balwinder

    2016-01-01

    Dust variability in the climate system has been studied for several decades, yet there remains an incomplete understanding of the dynamical mechanisms controlling interannual and decadal variations in dust transport. The sparseness of multi-year observational datasets has limited our understanding of the relationship between climate variations and atmospheric dust. We use available observations and a century-length fully coupled Community Earth System Model (CESM) simulation to show that the El Niño- Southern Oscillation (ENSO) exerts a control on North African dust transport during boreal summer. In CESM, this relationship is stronger over the dusty tropical North Atlantic than near Barbados, one of the few sites having a multi-decadal observed record. During strong La Niña summers in CESM, a statistically significant increase in lower tropospheric easterly wind is associated with an increase in North African dust transport over the Atlantic. Barbados dust and Pacific SST variability are only weakly correlated in both observations and CESM, suggesting that other processes are controlling the crossbasin variability of dust. We also use our CESM simulation to show that the relationship between downstream North African dust transport and ENSO fluctuates on multidecadal timescales and may be modulated by the North Atlantic Oscillation (NAO). Our findings indicate that existing observations of dust over the tropical North Atlantic are not extensive enough to completely describe the variability of dust and dust transport, and demonstrate the importance of global models to supplement and interpret observational records.

  14. Estimating the age of alleles by use of intraallelic variability

    SciTech Connect (OSTI)

    Slatkin, M.; Rannala, B.

    1997-02-01

    A method is presented for estimating the age of an allele by use of its frequency and the extent of variation among different copies. The method uses the joint distribution of the number of copies in a population sample and the coalescence times of the intraallelic gene genealogy conditioned on the number of copies. The linear birth-death process is used to approximate the dynamics of a rare allele in a finite population. A maximum-likelihood estimate of the age of the allele is obtained by Monte Carlo integration over the coalescence times. The method is applied to two alleles at the cystic fibrosis (CFTR) locus, {Delta}F508 and G542X, for which intraallelic variability at three intronic microsatellite loci has been examined. Our results indicate that G542X is somewhat older than {Delta}F508. Although absolute estimates depend on the mutation rates at the microsatellite loci, our results support the hypothesis that {Delta}F508 arose <500 generations ({approx}10,000 years) ago. 32 refs., 4 figs.

  15. Cataclysmic variables in the SUPERBLINK proper motion survey

    SciTech Connect (OSTI)

    Skinner, Julie N.; Thorstensen, John R.; Lépine, Sébastien

    2014-12-01

    We have discovered a new high proper motion cataclysmic variable (CV) in the SUPERBLINK proper motion survey, which is sensitive to stars with proper motions greater than 40 mas yr{sup −1}. This CV was selected for follow-up observations as part of a larger search for CVs selected based on proper motions and their near-UV−V and V−K{sub s} colors. We present spectroscopic observations from the 2.4 m Hiltner Telescope at MDM Observatory. The new CV's orbital period is near 96 minutes, its spectrum shows the double-peaked Balmer emission lines characteristic of quiescent dwarf novae, and its V magnitude is near 18.2. Additionally, we present a full list of known CVs in the SUPERBLINK catalog.

  16. Evaluation of a photovoltaic energy mechatronics system with a built-in quadratic maximum power point tracking algorithm

    SciTech Connect (OSTI)

    Chao, R.M.; Ko, S.H.; Lin, I.H.; Pai, F.S.; Chang, C.C.

    2009-12-15

    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)

  17. Application of the Principle of Maximum Conformality to Top-Pair Production

    SciTech Connect (OSTI)

    Brodsky, Stanley J.; Wu, Xing-Gang; /SLAC /Chongqing U.

    2013-05-13

    A major contribution to the uncertainty of finite-order perturbative QCD predictions is the perceived ambiguity in setting the renormalization scale {mu}{sub r}. For example, by using the conventional way of setting {mu}{sub r} {element_of} [m{sub t}/2, 2m{sub t}], one obtains the total t{bar t} production cross-section {sigma}{sub t{bar t}} with the uncertainty {Delta}{sigma}{sub t{bar t}}/{sigma}{sub t{bar t}} {approx} (+3%/-4%) at the Tevatron and LHC even for the present NNLO level. The Principle of Maximum Conformality (PMC) eliminates the renormalization scale ambiguity in precision tests of Abelian QED and non-Abelian QCD theories. By using the PMC, all nonconformal {l_brace}{beta}{sub i}{r_brace}-terms in the perturbative expansion series are summed into the running coupling constant, and the resulting scale-fixed predictions are independent of the renormalization scheme. The correct scale-displacement between the arguments of different renormalization schemes is automatically set, and the number of active flavors n{sub f} in the {l_brace}{beta}{sub i}{r_brace}-function is correctly determined. The PMC is consistent with the renormalization group property that a physical result is independent of the renormalization scheme and the choice of the initial renormalization scale {mu}{sub r}{sup init}. The PMC scale {mu}{sub r}{sup PMC} is unambiguous at finite order. Any residual dependence on {mu}{sub r}{sup init} for a finite-order calculation will be highly suppressed since the unknown higher-order {l_brace}{beta}{sub i}{r_brace}-terms will be absorbed into the PMC scales higher-order perturbative terms. We find that such renormalization group invariance can be satisfied to high accuracy for {sigma}{sub t{bar t}} at the NNLO level. In this paper we apply PMC scale-setting to predict the t{bar t} cross-section {sigma}{sub t{bar t}} at the Tevatron and LHC colliders. It is found that {sigma}{sub t{bar t}} remains almost unchanged by varying {mu}{sub r}{sup init

  18. Variable energy constant current accelerator structure

    DOE Patents [OSTI]

    Anderson, O.A.

    1988-07-13

    A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90/degree/ intervals with opposing electrodes maintained at the same potential. 12 figs., 3 tabs.

  19. Measuring spatial variability in soil characteristics

    DOE Patents [OSTI]

    Hoskinson, Reed L.; Svoboda, John M.; Sawyer, J. Wayne; Hess, John R.; Hess, J. Richard

    2002-01-01

    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.

  20. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above $$10^{17.8}$$ eV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aab, Alexander

    2014-12-31

    We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 1017.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is described in detail as well as the experimental cross-checks and systematic uncertainties. Furthermore, we discuss the detector acceptance and the resolution of the Xmax measurement and provide parametrizations thereof as a function of energy. Finally, the energy dependence of the mean and standard deviation of the Xmax distributions are compared to air-shower simulations formore » different nuclear primaries and interpreted in terms of the mean and variance of the logarithmic mass distribution at the top of the atmosphere.« less

  1. Analysis of Biomass Feedstock Availability and Variability for the Peace River Region of Alberta, Canada

    SciTech Connect (OSTI)

    Stephen, Jamie; Sokhansanj, Shahabaddine; Bi, X.T.; Sowlati, T.; Kloeck, T.; Townley-Smith, Lawrence; Stumborg, Mark

    2009-11-01

    Biorefineries or other biomass-dependent facilities require a predictable, dependable feedstock supplied over many years to justify capital investments. Determining inter-year variability in biomass availability is essential to quantifying the feedstock supply risk. Using a geographic information system (GIS) and historic crop yield data, average production was estimated for 10 sites in the Peace River region of Alberta, Canada. Four high-yielding potential sites were investigated for variability over a 20 year time-frame (1980 2000). The range of availability was large, from double the average in maximum years to nothing in minimum years. Biomass availability is a function of grain yield, the biomass to grain ratio, the cropping frequency, and residue retention rate to ensure future crop productivity. Storage strategies must be implemented and alternate feedstock sources identified to supply biomass processing facilities in low-yield years.

  2. Variable pressure power cycle and control system

    DOE Patents [OSTI]

    Goldsberry, Fred L.

    1984-11-27

    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.

  3. Integrating Variable Renewable Energy: Challenges and Solutions

    SciTech Connect (OSTI)

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

    2013-09-01

    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.

  4. Production-Intent Lost-Motion Variable Valve Actuation Systems...

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

    Production-Intent Lost-Motion Variable Valve Actuation Systems Production-Intent Lost-Motion Variable Valve Actuation Systems Variable valve actuation with onoff IEGR pre-bump is ...

  5. Demonstration of variable speed permanent magnet generator at small, low-head hydro site

    SciTech Connect (OSTI)

    Brown Kinloch, David

    2015-12-18

    Small hydro developers face a limited set of bad choices when choosing a generator for a small low-head hydro site. Direct drive synchronous generators are expensive and technically complex to install. Simpler induction generators are higher speed, requiring a speed increaser, which results in inefficiencies and maintenance problems. In addition, both induction and synchronous generators turn at a fixed speed, causing the turbine to run off its peak efficiency curve whenever the available head is different than the designed optimum head.The solution to these problems is the variable speed Permanent Magnet Generators (PMG). At the Weisenberger Mill in Midway, KY, a variable speed Permanent Magnet Generator has been installed and demonstrated. This new PMG system replaced an existing induction generator that had a HTD belt drive speed increaser system. Data was taken from the old generator before it was removed and compared to data collected after the PMG system was installed. The new variable speed PMG system is calculated to produce over 96% more energy than the old induction generator system during an average year. This significant increase was primarily due to the PMG generator operating at the correct speed at the maximum head, and the ability for the PMG generator to reduce its speed to lower optimum speeds as the stream flow increased and the net head decreased.This demonstration showed the importance of being able to adjust the speed of fixed blade turbines. All fixed blade turbines with varying net heads could achieve higher efficiencies if the speed can be matched to the optimum speed as the head changes. In addition, this demonstration showed that there are many potential efficiencies that could be realized with variable speed technology at hydro sites where mismatched turbine and generator speeds result in lower power output, even at maximum head. Funding for this project came from the US Dept. of Energy, through Award Number DE-EE0005429.

  6. Carderock 3-ft Variable Pressure Cavitation Water Tunnel | Open...

    Open Energy Info (EERE)

    3-ft Variable Pressure Cavitation Water Tunnel Jump to: navigation, search Basic Specifications Facility Name Carderock 3-ft Variable Pressure Cavitation Water Tunnel Overseeing...

  7. Hydrogen-Assisted Fracture: Materials Testing and Variables Governing...

    Office of Environmental Management (EM)

    Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture Hydrogen-Assisted Fracture: Materials Testing and Variables Governing Fracture SNL has 40+ years ...

  8. Demonstration of a Variable Phase Turbine Power System for Low...

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

    Project objectives: Demonstrate a 1 megawatt Variable Phase Turbine and Variable Phase Cycle with low temperature brine. lowhaysvariablephaseturbine.pdf (732.28 KB) More ...

  9. Host Lipid and Temperature as Important Screening Variables for...

    Office of Scientific and Technical Information (OSTI)

    Host Lipid and Temperature as Important Screening Variables for Crystallizing Integral ... Screening Variables for Crystallizing Integral Membrane Proteins in Lipidic Mesophases. ...

  10. Compact, electro-hydraulic, variable valve actuation system providing...

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

    Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to enable high efficiency engine combustion control Compact, electro-hydrau...

  11. Enabling High Efficiency Clean Combustion with Micro-Variable...

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

    Clean Combustion with Micro-Variable Circular-Orifice (MVCO) Fuel Injector and Adaptive PCCI Enabling High Efficiency Clean Combustion with Micro-Variable Circular-Orifice (MVCO) ...

  12. Monte-Carlo particle dynamics in a variable specific impulse...

    Office of Scientific and Technical Information (OSTI)

    Monte-Carlo particle dynamics in a variable specific impulse magnetoplasma rocket Citation Details In-Document Search Title: Monte-Carlo particle dynamics in a variable specific ...

  13. Self-Referenced Continuous-Variable Quantum Key Distribution...

    Office of Scientific and Technical Information (OSTI)

    Self-Referenced Continuous-Variable Quantum Key Distribution Protocol Citation Details In-Document Search Title: Self-Referenced Continuous-Variable Quantum Key Distribution ...

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

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

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

  15. Estimation and Control of Diesel Engine Processes Utilizing Variable...

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

    Estimation and Control of Diesel Engine Processes Utilizing Variable Intake Valve Actuation Air handling system model for multi-cylinder variable geometry turbocharged diesel ...

  16. Variability in Mechanical Properties of Laser Engineered Net...

    Office of Scientific and Technical Information (OSTI)

    Variability in Mechanical Properties of Laser Engineered Net Shaping Material. Citation Details In-Document Search Title: Variability in Mechanical Properties of Laser Engineered ...

  17. Carderock 2-ft Variable Pressure Cavitation Water Tunnel | Open...

    Open Energy Info (EERE)

    is a vertical plane, closed recirculating, variable-speed, variable-pressure, open jet test section, closed jet test section, and semi-rectangular test section. Towing...

  18. Galactic Variable Sky with EGRET and GLAST

    SciTech Connect (OSTI)

    Digel, S.W.; /SLAC

    2006-11-28

    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.

  19. Chapter 18: Variable Frequency Drive Evaluation Protocol

    SciTech Connect (OSTI)

    Romberger, J.

    2014-11-01

    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.

  20. The variable sky of deep synoptic surveys

    SciTech Connect (OSTI)

    Ridgway, Stephen T.; Matheson, Thomas; Mighell, Kenneth J.; Olsen, Knut A. [National Optical Astronomy Observatory, Tucson, AZ 85725 (United States); Howell, Steve B., E-mail: ridgway@noao.edu [NASA Ames Research Center, P.O. Box 1, M/S 244-30, Moffett Field, CA 94035 (United States)

    2014-11-20

    The discovery of variable and transient sources is an essential product of synoptic surveys. The alert stream will require filtering for personalized criteriaa process managed by a functionality commonly described as a Broker. In order to understand quantitatively the magnitude of the alert generation and Broker tasks, we have undertaken an analysis of the most numerous types of variable targets in the skyGalactic stars, quasi-stellar objects (QSOs), active galactic nuclei (AGNs), and asteroids. It is found that the Large Synoptic Survey Telescope (LSST) will be capable of discovering ?10{sup 5} high latitude (|b| > 20) variable stars per night at the beginning of the survey. (The corresponding number for |b| < 20 is orders of magnitude larger, but subject to caveats concerning extinction and crowding.) However, the number of new discoveries may well drop below 100 per night within less than one year. The same analysis applied to GAIA clarifies the complementarity of the GAIA and LSST surveys. Discovery of AGNs and QSOs are each predicted to begin at ?3000 per night and decrease by 50 times over four years. Supernovae are expected at ?1100 per night, and after several survey years will dominate the new variable discovery rate. LSST asteroid discoveries will start at >10{sup 5} per night, and if orbital determination has a 50% success rate per epoch, they will drop below 1000 per night within two years.

  1. Observation

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

    tearing mode deceleration and locking due to eddy currents induced in a conducting shell B. E. Chapman Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 R. Fitzpatrick Institute for Fusion Studies, Department of Physics, University of Texas at Austin, Austin, Texas 78712 D. Craig Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 P. Martin Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Corso Stati Uniti 4, 35127 Padova, Italy

  2. Observation

    Office of Scientific and Technical Information (OSTI)

    to an Orbital-Selective Mott Phase in A x Fe 2-y Se 2 (AK, Rb) Superconductors M. Yi, 1, 2 D. H. Lu, 3 R. Yu, 4 S. C. Riggs, 1, 2 J.-H. Chu, 1, 2 B. Lv, 5 Z. Liu, 1, 2 M. Lu,...

  3. The role of water vapor feedback in unperturbed climate variability and global warming

    SciTech Connect (OSTI)

    Hall, A.; Manabe, Syukuro

    1999-08-01

    To understand the role of water vapor feedback in unperturbed surface temperature variability, a version of the Geophysical Fluid Dynamics Laboratory coupled ocean-atmosphere model is integrated for 1,000 yr in two configurations, one with water vapor feedback and one without. To understand the role of water vapor feedback in global warming, two 500-yr integrations were also performed in which CO{sub 2} was doubled in both model configurations. The final surface global warming in the model with water vapor feedback is 3.38 C, while in the one without it is only 1.05 C. However, the model`s water vapor feedback has a larger impact on surface warming in response to a doubling of CO{sub 2} than it does on internally generated, low-frequency, global-mean surface temperature anomalies. Water vapor feedback`s strength therefore depends on the type of temperature anomaly it affects. Finally, the authors compare the local and global-mean surface temperature time series from both unperturbed variability experiments to the observed record. The experiment without water vapor feedback does not have enough global-scale variability to reproduce the magnitude of the variability in the observed global-mean record, whether or not one removes the warming trend observed over the past century. In contrast, the amount of variability in the experiment with water vapor feedback is comparable to that of the global-mean record, provided the observed warming trend is removed. Thus, the authors are unable to simulate the observed levels of variability without water vapor feedback.

  4. Field observations and lessons learned

    SciTech Connect (OSTI)

    Nielsen, Joh B

    2010-01-01

    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.

  5. Physiological and growth responses of C3 and C4 plants at the Pleistocene glacial maximum

    SciTech Connect (OSTI)

    Strain, B.R.

    1995-06-01

    A C3 plant (Abutilon theophrasti) and a C4 plant (Amaranthus retroflexus) were grown from seed in the Duke University Phytotron under four CO2 concentrations (15 Pa, below the Pleistocene minimum), 27 Pa (pre-industrial), 35 Pa (current), and 70 Pa (future) to examine photosynthetic, growth and reproduction responses of annual plants to historic and future levels of CO2. Net photosynthesis and growth were greatly inhibited at 15 Pa and greatly stimulated at 70 Pa. in the C3 Abutilon but only slightly affected in the C4 Amaranthus. Flower bud initiation was not affected by CO2 treatment in either species but all flower buds in 15 Pa CO2 aborted in the C3 within two days of appearance while no inhibition of reproduction was observed at low CO2 in the C4. Differences in physiology, growth and reproduction to the low levels of atmospheric CO2 of the Pleistocene suggest that competitive interactions of C3 and C4 annuals have changed through geologic time. A major question concerning the survival and evolution of obligate C3 annuals during the CO2 minima of the Pleistocene is raised by the results of this study.

  6. Thermodynamic properties of mesoscale convective systems observed during BAMEX

    SciTech Connect (OSTI)

    Correia, James; Arritt, R.

    2008-11-01

    Dropsonde observations from the Bow-echo and Mesoscale convective vortex EXperiment (BAMEX) are used to document the spatio-temporal variability of temperature, moisture and wind within mesoscale convective systems (MCSs). Onion type sounding structures are found throughout the stratiform region of MCSs but the temperature and moisture variability is large. Composite soundings were constructed and statistics of thermodynamic variability were generated within each sub-region of the MCS. The calculated air vertical velocity helped identify subsaturated downdrafts. We found that lapse rates within the cold pool varied markedly throughout the MCS. Layered wet bulb potential temperature profiles seem to indicate that air within the lowest several km comes from a variety of source regions. We also found that lapse rate transitions across the 0 C level were more common than isothermal, melting layers. We discuss the implications these findings have and how they can be used to validate future high resolution numerical simulations of MCSs.

  7. Final Technical Report: Low-Cost Solar Variability Sensors for Ubiquitous Deployment.

    SciTech Connect (OSTI)

    Lave, Matthew Samuel

    2016-01-01

    In this project, an integrated solution to measuring and collecting solar variability data called the solar variability datalogger (SVD) was developed, tested, and the value of its data to distribution grid integration studies was demonstrated. This work addressed the problem that high-frequency solar variability is rarely measured – due to the high cost and complex installation of existing solar irradiance measuring pyranometers – but is critical to the accurate determination of the impact of photovoltaics to electric grid operation. For example, up to a 300% difference in distribution grid voltage regulator tap change operations (a measure of the impact of PV) [1] has been observed due solely to different solar variability profiles.

  8. MILLISECOND PULSAR AGES: IMPLICATIONS OF BINARY EVOLUTION AND A MAXIMUM SPIN LIMIT

    SciTech Connect (OSTI)

    Kiziltan, Buelent; Thorsett, Stephen E., E-mail: bulent@astro.ucsc.ed [Department of Astronomy and Astrophysics, University of California and UCO/Lick Observatory, Santa Cruz, CA 95064 (United States)

    2010-05-20

    In the absence of constraints from the binary companion or supernova remnant, the standard method for estimating pulsar ages is to infer an age from the rate of spin-down. While the generic spin-down age may give realistic estimates for normal pulsars, it can fail for pulsars with very short periods. Details of the spin-up process during the low-mass X-ray binary (LMXB) phase pose additional constraints on the period (P) and spin-down rates ( P-dot ) that may consequently affect the age estimate. Here, we propose a new recipe to estimate millisecond pulsar (MSP) ages that parametrically incorporates constraints arising from binary evolution and limiting physics. We show that the standard method can be improved by this approach to achieve age estimates closer to the true age while the standard spin-down age may overestimate or underestimate the age of the pulsar by more than a factor of {approx}10 in the millisecond regime. We use this approach to analyze the population on a broader scale. For instance, in order to understand the dominant energy loss mechanism after the onset of radio emission, we test for a range of plausible braking indices. We find that a braking index of n = 3 is consistent with the observed MSP population. We demonstrate the existence and quantify the potential contributions of two main sources of age corruption: the previously known 'age bias' due to secular acceleration and 'age contamination' driven by sub-Eddington progenitor accretion rates. We explicitly show that descendants of LMXBs that have accreted at very low rates ( m-dot << M-dot{sub Edd}) will exhibit ages that appear older than the age of the Galaxy. We further elaborate on this technique, the implications and potential solutions it offers regarding MSP evolution, the underlying age distribution, and the post-accretion energy loss mechanism.

  9. An evaluation of the maximum tag burden for implantation of acoustic transmitters in juvenile Chinook salmon

    SciTech Connect (OSTI)

    Brown, Richard S.; Harnish, Ryan A.; Carter, Kathleen M.; Boyd, James W.; Deters, Katherine A.; Eppard, M. B.

    2010-04-01

    Abstract.—The influence of a surgically implanted acoustic micro-transmitter and passive integrated transponder (PIT) tag on the growth and survival of hatchery-reared juvenile Chinook salmon was examined. Growth and survival were compared between treatment (implanted) and control fish within three fork length (FL) size groups (80-89, 90-99, and 100-109 mm). The acoustic micro-transmitter and PIT tag implanted in our study had a combined weight of 0.74 g. Weights of study fish ranged from 4.7 to 16.3 g for treatment fish and from 5.1 to 16.8 g for control fish. The burden for the combined acoustic and PIT tag experienced by implanted fish ranged from 8.8% to 15.7% for the 80-89 mm FL group, 6.0-10.9% for the 90-99 mm FL group, and 4.5-8.6% for the 100-109 mm FL group. Results indicated that growth and survival were size-dependent among implanted juvenile Chinook salmon. Significant differences in growth rate and survival were observed between treatment and control fish in the 80-89 mm FL group. Within this group, growth of fish smaller than 88.5 mm FL (tag burden > 10.0%) was negatively affected by the implantation or presence of an acoustic micro-transmitter and PIT tag. Survival of fish in the 90-99 mm FL group did not differ between treatment and control fish. However, survival of implanted fish within this size group that were smaller than 97.2 mm FL (tag burden > 7.4%) was negatively influenced. These results indicate that the burden of an acoustic micro-transmitter and PIT tag should be maintained at or below about 7.0% for studies that use hatchery-reared juvenile Chinook salmon.

  10. Observing terrestrial ecosystems and the carbon cycle from space

    SciTech Connect (OSTI)

    Schimel, David; Pavlick, Ryan; Fisher, Joshua B.; Asner, Gregory P.; Saatchi, Sassan; Townsend, Philip; Miller, Charles E.; Frankenberg, Christian; Hibbard, Kathleen A.; Cox, Peter

    2015-02-06

    Modeled terrestrial ecosystem and carbon cycle feedbacks contribute substantial uncertainty to projections of future climate. The limitations of current observing networks contribute to this uncertainty. Here we present a current climatology of global model predictions and observations for photosynthesis, biomass, plant diversity and plant functional diversity. Carbon cycle tipping points occur in terrestrial regions where fluxes or stocks are largest, and where biological variability is highest, the tropics and Arctic/Boreal zones. Global observations are predominately in the mid-latitudes and are sparse in high and low latitude ecosystems. Observing and forecasting ecosystem change requires sustained observations of sufficient density in time and space in critical regions. Using data and theory available now, we can develop a strategy to detect and forecast terrestrial carbon cycle-climate interactions, by combining in situ and remote techniques.