Sample records for 5-cm period undulator

  1. Variable-Period Undulators For Synchrotron Radiation

    DOE Patents [OSTI]

    Shenoy, Gopal (Naperville, IL); Lewellen, John (Plainfield, IL); Shu, Deming (Darien, IL); Vinokurov, Nikolai (Novosibirsk, RU)

    2005-02-22T23:59:59.000Z

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  2. Variable-Period Undulators for Synchrotron Radiation

    SciTech Connect (OSTI)

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

    2005-02-22T23:59:59.000Z

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  3. Configurations for short period rf undulators

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

    Kuzikov, S. V.; Jiang, Y.; Marshall, T. C.; Sotnikov, G. V.; Hirshfield, J. L.

    2013-07-01T23:59:59.000Z

    Several configurations for rf undulators energized at millimeter wavelengths and designed to produce coherent nanometer radiation from sub-GeV electron beams are analyzed and compared with one another. These configurations include a traveling-wave resonant ring, a standing wave resonator, and a resonator operating close to cutoff.

  4. Cooperative accumulation of coherent undulator radiation emitted from periodic electron bunches

    SciTech Connect (OSTI)

    Seo, Y. H. [Department of Electrophysics, Kwangwoon University, Seoul 139-701 (Korea, Republic of)

    2013-01-15T23:59:59.000Z

    Cavity build-up of coherent undulator synchrotron radiation emitted by periodic electron bunches is investigated. At the optimal off-grazing resonance, the bunch slippage relative to the radiation pulse introduces an initial transient period during which radiation accumulates cooperatively as if it is emitted by a single bunch. The power growth during the period is quadratic to the number of bunches. The number of cooperative bunches is {approx}2 Script-Small-L {sub s}{sup 2}, where Script-Small-L {sub s} denotes the slippage length in units of the resonant wavelength.

  5. The U5. 0 Undulator for the ALS

    SciTech Connect (OSTI)

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.

    1991-05-01T23:59:59.000Z

    The U5.0 Undulator, an 89 period, 5 cm period length, 4.6 m long insertion device has been designed and is in fabrication. This undulator will be the first high brightness source, in the 50 to 1500 eV range, for the Advanced Light Source (ALS) and is scheduled for completion in 1992. A modular hybrid configuration utilizing Nd-Fe-B permanent magnet material and vanadium permendur is used that achieves 0.837 Tesla effective peak field. Correction of the vertical field integral is with permanent magnet rotors at the ends. Gap adjustment is with an arrangement of roller screws, chains drives, a gear reduction unit and a stepper motor driven by a closed loop control system. The vacuum chamber design is a two-piece, machined and welded 5083-H321 aluminum construction of 5.1 m length. Magnetic design, subsystem design and fabrication progress are presented. 12 refs., 4 figs., 2 tabs.

  6. The JLAB UV Undulator

    SciTech Connect (OSTI)

    Gottschalk, Steven C. [STI, Washington, USA; Benson, Steven V. [JLAB; Moore, Steven Wesley [JLAB

    2013-05-01T23:59:59.000Z

    Recently the JLAB FEL has demonstrated 150 W at 400 nm and 200 W at 700 nm using a 33mm period undulator designed and built by STI Optronics. This paper describes the undulator design and performance. Two key requirements were low phase error, zero steering and offset end fields and small rms trajectory errors. We will describe a new genetic algorithm that allowed phase error minimization to 1.8 degrees while exceeding specifications. The mechanical design, control system and EPICS interface will also be summarized.

  7. Micropole undulator

    DOE Patents [OSTI]

    Tatchyn, R.O.; Csonka, P.L.; Cremer, J.T.

    1990-12-11T23:59:59.000Z

    Micropole undulators for use in the generation of x-rays from moving charged particles are disclosed. Two rows of spaced apart poles are arranged so that each pole produces a magnetic field aligned with all other similar fields. The poles are the ends of C''-shaped magnets. In each row, adjacent poles are separated by spacers made of a superconducting material. 11 figs.

  8. Variable Gap Undulator for 1.5-48 Kev Free Electron Laser at Linac Coherent Light Source

    SciTech Connect (OSTI)

    Pellegrini, C.; /UCLA; Wu, J.; /SLAC; ,

    2011-08-17T23:59:59.000Z

    We study the feasibility of generating femtosecond duration Free-Electron Laser with a variable photon energy from 1.5 to 48 keV, using an electron bunch with the same characteristics of the LINAC Coherent Light Source (LCLS) bunch, and a planar undulator with additional focusing. We assume that the electron bunch energy can be changed, and the undulator has a variable gap, allowing a variable undulator parameter. It is assumed to be operated in an ultra-low charge and ultra-short pulse regime. We study the feasibility of a tunable, short pulse, X-ray FEL with photon energy from 1.5 to 48 keV, using an electron beam like the one in the LCLS and a 2:5 cm period, variable gap, planar undulator. The beam energy changes from 4.6 to 13.8 GeV, the electorn charge is kept at 10 pC, and the undulator parameter varies from 1 to 3. The undulator length needed to saturate the 48 keV FEL is about 55 m, with a peak power around 5 GW. At longer wavelength the saturation length is as short as 15 m, and the peak power around 20 GW. The results from the analytical models and the GENESIS simulations show that the system is feasible. The large wavelength range, full tunability and short, few femtosecond pulses, together with the large peak power, would provide a powerful research tool.

  9. On-axis brilliance and power of in-vacuum undulators for the Advanced Photon Source.

    SciTech Connect (OSTI)

    Dejus, R.; Jaski, M.; Kim, S. H.; Accelerator Systems Division (APS)

    2009-11-25T23:59:59.000Z

    A request for studying the spectral performance of in-vacuum undulators (IVUs) for the APS storage ring was recently put forward. In-vacuum undulators are prevalent at other synchrotron radiation facilities such as the ESRF and the Spring-8. However, they never made it into the arsenal of undulators at the APS because the brilliance tuning curves were sufficiently wide due to the fact that the undulator minimum gap could be set as low as 10.5 mm. For sector 3, which in the past used a narrow-gap vacuum chamber, the minimum undulator pole gap was allowed to be set as low as 8.5 mm, providing contiguous tuning curves between the first and third harmonic radiation for a 2.7-cm-period device. (Subsequently, the narrow-gap vacuum chamber was removed and replaced with a standard vacuum chamber, which allows a minimum gap of 10.5 mm.) For sector 4, which currently holds the only narrow-gap vacuum chamber at the APS, the minimum gap is 9.5 mm. In this sector, a permanent magnet hybrid undulator with SmCo magnets is used instead of NdFeB magnets because of their higher radiation resistance and their better protection against radiation-induced demagnetization of the magnets. In the realm of looking to the future, new concepts and technologies are being revisited. Most notable is the superconducting undulator (SCU) technology, which provides the ultimate highest magnetic field of any technology and design. The SCU program has been ongoing at the APS for several years and substantial progress has been made.3,4 However, the in-vacuum undulators may bridge some of the user demands, and it is therefore worthwhile revisiting their potential at the APS. In this work, the following were assumed or required: (1) the smallest in-vacuum beam-stay-clear gap is 5.0 mm, (2) a beam-liner of 2 x 0.060 mm, which increases the pole gap by the same amount, (3) both NdFeB and SmCo magnets shall be studied, even though SmCo magnets are the preferred choice for very small gaps, (4) compare the in-vacuum undulators with superconducting NbTi undulators with a wall thickness/space of 2 x 1.0 mm, and (5) all undulators will have an effective magnetic length of 2.4 m. Three short undulator period lengths were chosen somewhat arbitrary and studied. We will compare the performance of undulators with period lengths of 2.5 cm and 2.0 cm to one with a 1.6-cm period, which is the chosen period length of the first designed and tested short-length SCU for the APS. Additionally, we will make comparisons with the undulator A, which has a period length of 3.3 cm.

  10. LCLS-II Undulator Tolerance Analysis

    SciTech Connect (OSTI)

    Nuhn, H.-D.; /SLAC; Marks, S.; /LBL, Berkeley; Wu, J.; /SLAC

    2012-06-06T23:59:59.000Z

    The SLAC National Accelerator Laboratory is building a new FEL user facility, LCLS-II, as a major upgrade to the Linear Coherent Light Source (LCLS). The upgrade will include two new Free Electron Lasers (FELs), to generate soft (SXR) and hard x-ray (HXR) SASE FEL radiation, based on planar, variable gap hybrid undulators with two different undulator periods (SXU: 55 mm, HXU: 32 mm). An algebraic FEL tolerance analysis for the undulator lines, including tuning, alignment, and phase correction tolerances has been performed. The methods and results are presented in this paper.

  11. TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

    SciTech Connect (OSTI)

    R. C. O'Brien; J. E. O'Brien; C. M. Stoots; X. Zhang; S. C. Farmer; T. L. Cable; J. A. Setlock

    2011-11-01T23:59:59.000Z

    A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

  12. Performance Evaluation of Undulator Radiation at CEBAF

    SciTech Connect (OSTI)

    Chuyu Liu, Geoffrey Krafft, Guimei Wang

    2010-05-01T23:59:59.000Z

    The performance of undulator radiation (UR) at CEBAF with a 3.5 m helical undulator is evaluated and compared with APS undulator-A radiation in terms of brilliance, peak brilliance, spectral flux, flux density and intensity distribution.

  13. An Undulator Based Polarized Positron Source for CLIC

    SciTech Connect (OSTI)

    Liu, Wanming; /Argonne; Gai, Wei; /Argonne; Rinolfi, Louis; /CERN; Sheppard, John; /SLAC

    2012-07-02T23:59:59.000Z

    A viable positron source scheme is proposed that uses circularly polarized gamma rays generated from the main 250 GeV electron beam. The beam passes through a helical superconducting undulator with a magnetic field of {approx} 1 Tesla and a period of 1.15 cm. The gamma-rays produced in the undulator in the energy range between {approx} 3 MeV - 100 MeV will be directed to a titanium target and produce polarized positrons. The positrons are then captured, accelerated and transported to a Pre-Damping Ring (PDR). Detailed parameter studies of this scheme including positron yield, and undulator parameter dependence are presented. Effects on the 250 GeV CLIC main beam, including emittance growth and energy loss from the beam passing through the undulator are also discussed.

  14. Undulator-Based Production of Polarized Photons

    SciTech Connect (OSTI)

    Professor Kirk McDonald

    2008-05-29T23:59:59.000Z

    "Project Title: Undulator-Based Production of Polarized Photons" DOE Contract Number: FG02-04ER41355 Principal Investigator: Prof. Kirk McDonald Period of Performance: 09/10/2004 thru 08/31/2006 This award was to fund Princeton's activity on SLAC experiment E166, "Undulator-Based Production of Polarized Positrons" which was performed at SLAC during June and September 2005. Princeton U. fabricated a magnetic spectrometer for this experiment, and participated in the commissioning, operation, and analysis of the experiment, for which Prof. McDonald was a co-spokesperson. The experiment demonstrated that an intense positron beam with 80% longitudinal polarization could be generated by conversion of MeVenergy circularly polarized photons in a thin target, which photons were generated by passage of high-energy electrons through a helical undulator. This technique has since been adopted as the baseline for the polarized positron source of the proposed International Linear Collider. Results of the experiment have been published in Physical Review Letters, vol 100, p 210801 (2008) [see attached .pdf file], and a longer paper is in preparation.

  15. Coherent Radiation in an Undulator

    E-Print Network [OSTI]

    Chin, Y.H.

    2011-01-01T23:59:59.000Z

    solving the particle-radiation system in a self-consistentto clarify the coherent radiation mechanism. References 1.the Proceedings Coherent Radiation in an Undulator Y,H. Chin

  16. Electron Beam Alignment Strategy in the LCLS Undulators

    SciTech Connect (OSTI)

    Nuhn, H.-D.; Emma, P.J.; Gassner, G.L.; LeCocq, C.M.; Peters, E.; Ruland, R.E.; /SLAC

    2007-01-03T23:59:59.000Z

    The x-ray FEL process puts very tight tolerances on the straightness of the electron beam trajectory (2 {micro}m rms) through the LCLS undulator system. Tight but less stringent tolerances of 80 {micro}m rms vertical and 140 {micro}m rms horizontally are to be met for the placement of the individual undulator segments with respect to the beam axis. The tolerances for electron beam straightness can only be met through beam-based alignment (BBA) based on electron energy variations. Conventional alignment will set the start conditions for BBA. Precision-fiducialization of components mounted on remotely adjustable girders and the use of beam-finder wires (BFW) will satisfy placement tolerances. Girder movement due to ground motion and temperature changes will be monitored continuously by an alignment monitoring system (ADS) and remotely corrected. This stabilization of components as well as the monitoring and correction of the electron beam trajectory based on BPMs and correctors will increase the time between BBA applications. Undulator segments will be periodically removed from the undulator Hall and measured to monitor radiation damage and other effects that might degrade undulator tuning.

  17. The U5. 0 undulator design for the advanced light source at LBL

    SciTech Connect (OSTI)

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.; Savoy, R.

    1989-08-01T23:59:59.000Z

    The U5.0 undulator, currently under design, is the first in a series of insertion devices planned for the Advanced Light Source at LBL. U5.0 parameters include a 5 cm period, 5 m length with a 0.837 T maximum field at a 14 mm gap. A hybrid configuration utilizing Nd-Fe-B permanent magnet material and Vanadium Permendur poles is used for the magnetic structure. Construction is modular with many pole assemblies attached to a pole mount, which in turn is fastened onto one of the backing beams. Vertical field integral correction at the ends is with permanent magnet rotators. The supports structure features a 4-post configuration, a rigid base with 3 kinematic floor supports and 2 rigid 5 m long backing beams that fit within the 2.4 m high accelerator enclosure. The drive system is computer controlled utilizing a stepper motor and shaft encode coupled to a roller-screw/nut and chain drive train. Vacuum chamber design is a rigid configuration with a 10 mm vertical by 218 mm horizontal aperture of 5.5 m length. Chamber fabrication features a two-piece welded chamber of 5083 H321 aluminum. Pumping is with ion and titanium sublimation pumps. 5 figs., 1 tab.

  18. Mass Transfer Testing of a 12.5-cm Rotor Centrifugal Contactor

    SciTech Connect (OSTI)

    D. H. Meikrantz; T. G. Garn; J. D. Law; N. R. Mann; T. A. Todd

    2008-09-01T23:59:59.000Z

    TRUEX mass transfer tests were performed using a single stage commercially available 12.5 cm centrifugal contactor and stable cerium (Ce) and europium (Eu). Test conditions included throughputs ranging from 2.5 to 15 Lpm and rotor speeds of 1750 and 2250 rpm. Ce and Eu extraction forward distribution coefficients ranged from 13 to 19. The first and second stage strip back distributions were 0.5 to 1.4 and .002 to .004, respectively, throughout the dynamic test conditions studied. Visual carryover of aqueous entrainment in all organic phase samples was estimated at < 0.1 % and organic carryover into all aqueous phase samples was about ten times less. Mass transfer efficiencies of = 98 % for both Ce and Eu in the extraction section were obtained over the entire range of test conditions. The first strip stage mass transfer efficiencies ranged from 75 to 93% trending higher with increasing throughput. Second stage mass transfer was greater than 99% in all cases. Increasing the rotor speed from 1750 to 2250 rpm had no significant effect on efficiency for all throughputs tested.

  19. thorium en quilibre radioactif. Le thorium X donne le parcours 5 cm. 7, et l'manation du thorium, pour

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    181 thorium en équilibre radioactif. Le thorium X donne le parcours 5 cm. 7, et l'émanation du thorium, pour laquelle on a été obligé d'employer une méthode de scintillations, le parcours 5,5 cm. Les parcours des rayions a émis par le thorium et ses produits sont réu- nis dans le tableau ci-contre, ou l

  20. Start-to-end global imaging as a sunward propagating, SAPS-associated giant undulation event

    SciTech Connect (OSTI)

    Henderson, Michael G [Los Alamos National Laboratory; Donovan, Eric F [U OF CALGARY; Foster, John C [MIT; Mann, Ian R [UNIV OF ALBERTA; Immel, Thomas J [UC/BERKELEY; Mende, Stephen B [UN/BERKELEY; Sigwarth, John B [NASA/GSFC

    2009-01-01T23:59:59.000Z

    We present high-time resolution global imaging of a sunward propagating giant undulation event from start to finish. The event occurred on November 24, 2001 during a very disturbed storm interval. The giant undulations began to develop at around 13UT and persisted for approximately 2 hours. The sunward propagation speed was on the order of 0.6 km/s (relative to SM coordinate system). The undulations had a wavelength of {approx} 750 km, amplitudes of {approx} 890 km and produced ULF pulsations on the ground with a period of {approx} 1108s. We show that the undulations were associated with SAPs flows that were caused by the proton plasma sheet penetrating substantially farther Earthward than the electron plasma sheet on the duskside. The observations appear to be consistent with the development of a shear flow and/or ballooning type of instability at the plasmapause driven by intense SAPS-associated shear flows.

  1. LCLS Undulator Quadrupole Fiducialization Plan

    SciTech Connect (OSTI)

    Wolf, Zachary; Levashov, Michael; Lundahl, Eric; Reese, Ed; LeCocq, Catherine; Ruland, Robert; /SLAC; ,

    2010-11-24T23:59:59.000Z

    This note presents the fiducialization plan for the LCLS undulator quadrupoles. The note begins by summarizing the requirements for the fiducialization. A discussion of the measurement equipment is presented, followed by the methods used to perform the fiducialization and check the results. This is followed by the detailed fiducialization plan in which each step is enumerated. Finally, the measurement results and data storage formats are presented. The LCLS is made up of 33 assemblies consisting of an undulator, quadrupole, beam finder wire, and other components mounted on a girder. The components must be mounted in such a way that the beam passes down the axis of each component. In this note, we describe how the ideal beam axis is related to tooling balls on the quadrupole. This step, called fiducialization, is necessary because the ideal beam axis is determined magnetically, whereas tangible objects must be used to locate the quadrupole. The note begins with the list of fiducialization requirements. The laboratory in which the work will be performed and the relevant equipment is then briefly described. This is followed by a discussion of the methods used to perform the fiducialization and the methods used to check the results. A detailed fiducialization plan is presented in which all the steps of fiducialization are enumerated. A discussion of the resulting data files and directory structure concludes the note.

  2. Figure 2: The mercury jet target geometry. The proton beam and mercury jet cross at z=-37.5 cm.

    E-Print Network [OSTI]

    McDonald, Kirk

    Figure 2: The mercury jet target geometry. The proton beam and mercury jet cross at z=-37.5 cm. Figure 3: The layout of multiple proton beam entry directions relative to mercury jet at z=-75 cm. A PION of a free liquid mercury jet with an intense proton beam. We study the variation of meson production

  3. Algorithms to Automate LCLS Undulator Tuning

    SciTech Connect (OSTI)

    Wolf, Zachary

    2010-12-03T23:59:59.000Z

    Automation of the LCLS undulator tuning offers many advantages to the project. Automation can make a substantial reduction in the amount of time the tuning takes. Undulator tuning is fairly complex and automation can make the final tuning less dependent on the skill of the operator. Also, algorithms are fixed and can be scrutinized and reviewed, as opposed to an individual doing the tuning by hand. This note presents algorithms implemented in a computer program written for LCLS undulator tuning. The LCLS undulators must meet the following specifications. The maximum trajectory walkoff must be less than 5 {micro}m over 10 m. The first field integral must be below 40 x 10{sup -6} Tm. The second field integral must be below 50 x 10{sup -6} Tm{sup 2}. The phase error between the electron motion and the radiation field must be less than 10 degrees in an undulator. The K parameter must have the value of 3.5000 {+-} 0.0005. The phase matching from the break regions into the undulator must be accurate to better than 10 degrees. A phase change of 113 x 2{pi} must take place over a distance of 3.656 m centered on the undulator. Achieving these requirements is the goal of the tuning process. Most of the tuning is done with Hall probe measurements. The field integrals are checked using long coil measurements. An analysis program written in Matlab takes the Hall probe measurements and computes the trajectories, phase errors, K value, etc. The analysis program and its calculation techniques were described in a previous note. In this note, a second Matlab program containing tuning algorithms is described. The algorithms to determine the required number and placement of the shims are discussed in detail. This note describes the operation of a computer program which was written to automate LCLS undulator tuning. The algorithms used to compute the shim sizes and locations are discussed.

  4. Low local recurrence rate without postmastectomy radiation in node-negative breast cancer patients with tumors 5 cm and larger

    SciTech Connect (OSTI)

    Floyd, Scott R. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Harvard Radiation Oncology Program, Harvard Medical School, Boston, MA (United States); Buchholz, Thomas A. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Haffty, Bruce G. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States); Goldberg, Saveli [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Niemierko, Andrzej [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Raad, Rita Abi [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Oswald, Mary J. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Sullivan, Timothy [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Strom, Eric A. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Powell, Simon N. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Katz, Angela [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Taghian, Alphonse G. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)]. E-mail: ataghian@partners.org

    2006-10-01T23:59:59.000Z

    Purpose: To assess the need for adjuvant radiotherapy following mastectomy for patients with node-negative breast tumors 5 cm or larger. Methods and Materials: Between 1981 and 2002, a total of 70 patients with node-negative breast cancer and tumors 5 cm or larger were treated with mastectomy and adjuvant systemic therapies but without radiotherapy at three institutions. We retrospectively assessed rates and risk factors for locoregional failure (LRF), overall survival (OS), and disease-free survival (DFS) in these patients. Results: With a median follow-up of 85 months, the 5-year actuarial LRF rate was 7.6% (95% confidence interval, 3%-16%). LRF was primarily in the chest wall (4/5 local failures), and lymphatic-vascular invasion (LVI) was statistically significantly associated with LRF risk by the log-rank test (p = 0.017) and in Cox proportional hazards analysis (p 0.038). The 5-year OS and DFS rates were 83% and 86% respectively. LVI was also significantly associated with OS and DFS in both univariate and multivariate analysis. Conclusions: This series demonstrates a low LRF rate of 7.6% among breast cancer patients with node-negative tumors 5 cm and larger after mastectomy and adjuvant systemic therapy. Our data indicate that further adjuvant radiation therapy to increase local control may not be indicated by tumor size alone in the absence of positive lymph nodes. LVI was significantly associated with LRF in our series, indicating that patients with this risk factor require careful consideration with regard to further local therapy.

  5. Undulator Hall Air Temperature Fault Scenarios

    SciTech Connect (OSTI)

    Sevilla, J.; Welch, J.; /SLAC; ,

    2010-11-17T23:59:59.000Z

    Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.

  6. Coherent Radiation Effects in the LCLS Undulator

    SciTech Connect (OSTI)

    Reiche, S.; /UCLA; Huang, Z.; /SLAC

    2010-12-14T23:59:59.000Z

    For X-ray Free-Electron Lasers such as LCLS and TESLA FEL, a change in the electron energy while amplifying the FEL radiation can shift the resonance condition out of the bandwidth of the FEL. The largest sources of energy loss is the emission of incoherent undulator radiation. Because the loss per electron depends only on the undulator parameters and the beam energy, which are fixed for a given resonant wavelength, the average energy loss can be compensated for by a fixed taper of the undulator. Coherent radiation has a strong enhancement proportional to the number of electrons in the bunch for frequencies comparable to or longer than the bunch dimension. If the emitted coherent energy becomes comparable to that of the incoherent emission, it has to be included in the taper as well. However, the coherent loss depends on the bunch charge and the applied compression scheme and a change of these parameters would require a change of the taper. This imposes a limitation on the practical operation of Free-Electron Lasers, where the taper can only be adjusted manually. In this presentation we analyze the coherent emission of undulator radiation and transition undulator radiation for LCLS, and estimate whether the resulting energy losses are significant for the operation of LCLS.

  7. Hydraulic and Clean-in-Place Evaluations for a 12.5-cm Annular Centrifugal Contactor at INL

    SciTech Connect (OSTI)

    Troy G. Garn; David H. Meikrantz; Nick R. Mann; Jack D. Law; Terry A. Todd

    2008-09-01T23:59:59.000Z

    Hydraulic and Clean-in-Place Evaluations for a 12.5 cm Annular Centrifugal Contactor at the INL Troy G. Garn, Dave H. Meikrantz, Nick R. Mann, Jack D. Law, Terry A. Todd Idaho National Laboratory Commercially available, Annular Centrifugal Contactors (ACC) are currently being evaluated for processing dissolved nuclear fuel solutions to selectively partition integrated elements using solvent extraction technologies. These evaluations include hydraulic and clean-in-place (CIP) testing of a commercially available 12.5 cm unit. Data from these evaluations is used to support design of future nuclear fuel reprocessing facilities. Hydraulic testing provides contactor throughput performance data on two-phase systems for a wide range of operating conditions. Hydraulic testing results on a simple two-phase oil and water system followed by a 30 % Tributyl phosphate in N-dodecane / nitric acid pair are reported. Maximum total throughputs for this size contactor ranged from 20 to 32 liters per minute without significant other phase carryover. A relatively new contactor design enhancement providing Clean-in-Place capability for ACCs was also investigated. Spray nozzles installed into the central rotor shaft allow the rotor internals to be cleaned, offline. Testing of the solids capture of a diatomaceous earth/water slurry feed followed by CIP testing was performed. Solids capture efficiencies of >95% were observed for all tests and short cold water cleaning pulses proved successful at removing solids from the rotor.

  8. Planar Undulator Considerations(LCC-0085)

    SciTech Connect (OSTI)

    Sheppard, J

    2003-10-07T23:59:59.000Z

    This note consists of informal working notes that document an effort to understand the TESLA baseline, unpolarized, undulator based positron source. This is the first step in the design process of an undulator based positron system for the NLC. The expressions and methodologies developed herein are used in subsequent memos that reference this note. In regards to the TESLA design, it is found that a 135 m long (versus 100 m length) undulator is consistent with the performance descriptions in the TDR text. And while operation of the TESLA system with a 250 GeV drive beam energy provides a safety margin of a factor of {approx}2 in e{sup +} yield, operation of the same system at 160 GeV results in a yield of about 0.6.

  9. Strong permanent magnet-assisted electromagnetic undulator

    DOE Patents [OSTI]

    Halbach, Klaus (Berkeley, CA)

    1988-01-01T23:59:59.000Z

    This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles.

  10. Air Temperature in the Undulator Hall

    SciTech Connect (OSTI)

    Not Available

    2010-12-07T23:59:59.000Z

    Various analyses have been performed recently to estimate the performance of the air conditioning (HVAC) system planned for the Undulator Hall. This reports summarizes the results and provides an upgrade plan to be used if new requirements are needed in the future. The estimates predict that with the planned loads the tunnel air temperature will be well within the allowed tolerance during normal operation.

  11. Proposed Laser-driven, Dielectric Microstructure Few-cm Long Undulator for Attosecond Coherent X-rays

    SciTech Connect (OSTI)

    Plettner, T; Byer, R.L.; /Stanford U., Ginzton Lab.

    2011-09-16T23:59:59.000Z

    This article presents the concept of an all-dielectric laser-driven undulator for the generation of coherent X-rays. The proposed laser-driven undulator is expected to produce internal deflection forces equivalent to a several-Tesla magnetic field acting on a speed-of-light particle. The key idea for this laser-driven undulator is its ability to provide phase synchronicity between the deflection force and the electron beam for a distance that is much greater than the laser wavelength. The potential advantage of this undulator is illustrated with a possible design example that assumes a small laser accelerator which delivers a 2 GeV, 1 pC, 1 kHz electron bunch train to a 10 cm long, 1/2 mm period laser-driven undulator. Such an undulator could produce coherent X-ray pulses with {approx}10{sup 9} photons of 64 keV energy. The numerical modeling for the expected X-ray pulse shape was performed with GENESIS, which predicts X-ray pulse durations in the few-attosecond range. Possible applications for nonlinear electromagnetic effects from these X-ray pulses are briefly discussed.

  12. Undulations from amplified low frequency surface waves

    SciTech Connect (OSTI)

    Coutant, Antonin, E-mail: antonin.coutant@aei.mpg.de [Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Am Muhlenberg 1, 14476 Golm (Germany)] [Max Planck Institute for Gravitational Physics, Albert Einstein Institute, Am Muhlenberg 1, 14476 Golm (Germany); Parentani, Renaud, E-mail: renaud.parentani@th.u-psud.fr [Laboratoire de Physique Thorique, CNRS UMR 8627, Btiment 210, Universit Paris-Sud 11, 91405 Orsay Cedex (France)] [Laboratoire de Physique Thorique, CNRS UMR 8627, Btiment 210, Universit Paris-Sud 11, 91405 Orsay Cedex (France)

    2014-04-15T23:59:59.000Z

    We study the linear scattering of gravity waves in longitudinal inhomogeneous stationary flows. When the flow becomes supercritical, it is known that counterflow propagating shallow waves are blocked and converted into deep waves. Here we show that in the zero-frequency limit, the reflected waves are amplified in such a way that the free surface develops an undulation, i.e., a zero-frequency wave of large amplitude with nodes located at specific places. This amplification involves negative energy waves and implies that flat surfaces are unstable against incoming perturbations of arbitrary small amplitude. The relation between this instability and black hole radiation (the Hawking effect) is established.

  13. A Benchmark Construction of Positron Crystal Undulator

    E-Print Network [OSTI]

    Tikhomirov, Victor V

    2015-01-01T23:59:59.000Z

    Optimization of a positron crystal undulator (CU) is addressed. The ways to assure both the maximum intensity and minimum spectral width of positron CU radiation are outlined. We claim that the minimum CU spectrum width of 3 -- 4% is reached at the positron energies of a few GeV and that the optimal bending radius of crystals planes in CU ranges from 3 to 5 critical bending radii for channeled particles. Following suggested approach a benchmark positron CU construction is devised and its functioning is illustrated using the simulation method widely tested by experimental data.

  14. Results of beam-based alignment in undulator section

    E-Print Network [OSTI]

    (masking incoming dispersion) and correct up to now: step 1 done, step 2 (only vert. plane) #12;Procedure and photons so that the SASE process can take place in the whole undulator section #12;BBA in undulator: steps generated by quads #12;horizontal vertical Technical Note 05-04 #12;red: Soll position of quads black: Ist

  15. Tapering studies for Terawatt level X-ray FELs with a superconducting undulator

    E-Print Network [OSTI]

    Emma, Claudio; Emma, Paul; Huang, Zhirong; Pellegrini, Claudio

    2015-01-01T23:59:59.000Z

    We study the tapering optimization scheme for a short period, less than two cm, superconducting undulator, and show that it can generate 4 keV X-ray pulses with peak power in excess of 1 terawatt, using LCLS electron beam parameters. We study the e?ect of undulator module length relative to the FEL gain length for continous and step-wise taper pro?les. For the optimal section length of 1.5m we study the evolution of the FEL process for two di?erent superconducting technologies NbTi and Nb3Sn. We discuss the major factors limiting the maximum output power, particle detrapping around the saturation location and time dependent detrapping due to generation and ampli?cation of sideband modes.

  16. An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator

    SciTech Connect (OSTI)

    Anania, M. P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); INFN, Laboratori Nazionali di Frascati, I-00044 Frascati (Italy); Brunetti, E.; Wiggins, S. M.; Grant, D. W.; Welsh, G. H.; Issac, R. C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; Jaroszynski, D. A., E-mail: d.a.jaroszynski@strath.ac.uk [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Geer, S. B. van der; Loos, M. J. de [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands); Poole, M. W.; Shepherd, B. J. A.; Clarke, J. A. [ASTeC, STFC, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Gillespie, W. A. [SUPA, School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); MacLeod, A. M. [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee DD1 1HG (United Kingdom)

    2014-06-30T23:59:59.000Z

    Narrow band undulator radiation tuneable over the wavelength range of 150260?nm has been produced by short electron bunches from a 2?mm long laser plasma wakefield accelerator based on a 20?TW femtosecond laser system. The number of photons measured is up to 9??10{sup 6} per shot for a 100 period undulator, with a mean peak brilliance of 1??10{sup 18} photons/s/mrad{sup 2}/mm{sup 2}/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120130?MeV with the radiation pulse duration in the range of 50100 fs.

  17. UNDULATOR-BASED LASER WAKEFIELD ACCELERATOR ELECTRON BEAM DIAGNOSTIC

    SciTech Connect (OSTI)

    Bakeman, M.S.; Fawley, W.M.; Leemans, W. P.; Nakamura, K.; Robinson, K.E.; Schroeder, C.B.; Toth, C.

    2009-05-04T23:59:59.000Z

    to couple the THUNDER undulator to the LOASIS Lawrence Berkeley National Laboratory (LBNL) laser wakefield accelerator (LWFA). Currently the LWFA has achieved quasi-monoenergetic electron beams with energies up to 1 GeV. These ultra-short, high-peak-current, electron beams are ideal for driving a compact XUV free electron laser (FEL). Understanding the electron beam properties such as the energy spread and emittance is critical for achieving high quality light sources with high brightness. By using an insertion device such as an undulator and observing changes in the spontaneous emission spectrum, the electron beam energy spread and emittance can be measured with high precision. The initial experiments will use spontaneous emission from 1.5 m of undulator. Later experiments will use up to 5 m of undulator with a goal of a high gain, XUV FEL.

  18. On the Kinematics of Undulator Girder Motion

    SciTech Connect (OSTI)

    Welch, J; /SLAC; ,

    2011-08-18T23:59:59.000Z

    The theory of rigid body kinematics is used to derive equations that govern the control and measurement of the position and orientation of undulator girders. The equations form the basis of the girder matlab software on the LCLS control system. The equations are linear for small motion and easily inverted as desired. For reference, some relevant girder geometrical data is also given. Equations 6-8 relate the linear potentiometer readings to the motion of the girder. Equations 9-11 relate the cam shaft angles to the motion of the girder. Both sets are easily inverted to either obtain the girder motion from the angles or readings, or, to find the angles and readings that would give a desired motion. The motion of any point on the girder can be calculated by applying either sets of equations to the two cam-planes and extrapolating in the z coordinate using equation 19. The formulation of the equations is quite general and easily coded via matrix and vector methods. They form the basis of the girder matlab software on the LCLS control system.

  19. Scaling of EPR spectral-spatial images with size of sample: Images of a sample greater than 5 cm in linear dimension

    SciTech Connect (OSTI)

    Ahn, Kang-Hyun; Subramanian, V. S.; Halpern, Howard J. [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois 60637 and Center for EPR Imaging in Vivo Physiology, University of Chicago, Chicago, Illinois 60637 (United States)

    2007-12-15T23:59:59.000Z

    The authors have obtained spectral-spatial EPR images of a phantom significantly larger than those previously obtained. Images of a homogeneous phantom 4.2 cm in diameter and 6.5 cm in length with B{sub 1} equivalent to that used for smaller samples give a similar linewidth resolution both with linewidth population distributions of width 0.1 {mu}T. Spatial resolution appeared to have modest degradation. Images of the large homogeneous phantom provide maps of the magnetic field of a partially shimmed magnet.

  20. Resistive Wall Heating of the Undulator in High Repetition Rate

    SciTech Connect (OSTI)

    Qiang, J; Corlett, J; Emma, P; Wu, J

    2012-05-20T23:59:59.000Z

    In next generation high repetition rate FELs, beam energy loss due to resistive wall wakefields will produce significant amount of heat. The heat load for a superconducting undulator (operating at low temperature), must be removed and will be expensive to remove. In this paper, we study this effect in an undulator proposed for a Next Generation Light Source (NGLS) at LBNL. We benchmark our calculations with measurements at the LCLS and carry out detailed parameter studies using beam from a start-to-end simulation. Our preliminarym results suggest that the heat load in the undulator is about 2 W/m or lower with an aperture size of 6 mm for nominal NGLS preliminary design parameters.

  1. NSLS IN-VACUUM UNDULATORS AND MINI-BETA STRAIGHTS.

    SciTech Connect (OSTI)

    RAKOWSKY,G.; LYNCH,D.; BLUM,E.B.; KRINSKY,S.

    2001-06-18T23:59:59.000Z

    We review the work carried out in the X13 R&D Straight Section of the NSLS X-Ray Ring on small gap in-vacuum undulators (IVUNs). Then we discuss: (1) plans to replace the pure permanent magnet undulator in X13 by a hybrid design providing stronger magnetic fields, enhancing the tunability of the device; (2) plans to install hybrid IVUNs in the two RF straights of the X-Ray Ring, increasing the number of insertion devices in the XRay Ring to eight; (3) the possibility of reducing the vertical beta function in the X13 straight from 0.33 m down to 0.16 m. This reduction in beta function would allow us to decrease the usable undulator gap from 3mm down to 2mm, further increasing the tuning range.

  2. First results of a superconducting undulator on the ACO storage ring (*) (**)

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    L-547 First results of a superconducting undulator on the ACO storage ring (*) (**) C. Bazin (1), M. 2014 A superconducting undulator has been fixed on the ACO storage ring. It has been observed

  3. A strong permanent magnet-assisted electromagnetic undulator

    DOE Patents [OSTI]

    Halbach, K.

    1987-01-30T23:59:59.000Z

    This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles. 4 figs.

  4. Triggering for Magnetic Field Measurements of the LCLS Undulators

    SciTech Connect (OSTI)

    Hacker, Kirsten

    2010-12-13T23:59:59.000Z

    A triggering system for magnetic field measurements of the LCLS undulators has been built with a National Instruments PXI-1002 and a Xylinx FPGA board. The system generates single triggers at specified positions, regardless of encoder sensor jitter about a linear scale.

  5. Influence of surface traction on soft robot undulation

    E-Print Network [OSTI]

    Liu, David R.

    , assist in human motor tasks, and reduce manufacturing costs. As with natural invertebrates, soft robotsArticle Influence of surface traction on soft robot undulation The International Journal of Robotics Research 32(13) 15771584 The Author(s) 2013 Reprints and permissions: sagepub

  6. The LCLS Undulator Beam Loss Monitor Readout System

    SciTech Connect (OSTI)

    Dusatko, John; Browne, M.; Fisher, A.S.; Kotturi, D.; Norum, S.; Olsen, J.; /SLAC

    2012-07-23T23:59:59.000Z

    The LCLS Undulator Beam Loss Monitor System is required to detect any loss radiation seen by the FEL undulators. The undulator segments consist of permanent magnets which are very sensitive to radiation damage. The operational goal is to keep demagnetization below 0.01% over the life of the LCLS. The BLM system is designed to help achieve this goal by detecting any loss radiation and indicating a fault condition if the radiation level exceeds a certain threshold. Upon reception of this fault signal, the LCLS Machine Protection System takes appropriate action by either halting or rate limiting the beam. The BLM detector consists of a PMT coupled to a Cherenkov radiator located near the upstream end of each undulator segment. There are 33 BLMs in the system, one per segment. The detectors are read out by a dedicated system that is integrated directly into the LCLS MPS. The BLM readout system provides monitoring of radiation levels, computation of integrated doses, detection of radiation excursions beyond set thresholds, fault reporting and control of BLM system functions. This paper describes the design, construction and operational performance of the BLM readout system.

  7. Similarity of structuring in the range 10^{-5} cm to 10^23 cm hints at a baryonic cold dark skeleton of the Universe

    E-Print Network [OSTI]

    A. B. Kukushkin; V. A. Rantsev-Kartinov

    2002-05-30T23:59:59.000Z

    The presence of skeletal structures of the same distinctive topology (cartwheels, tubules, etc.), in the range 10^{-5} - 10^23 cm, and a trend toward self-similarity of these structures are found. These evidences come from the electron micrography of dust deposits in tokamak (10^{-6} - 10^{-3}cm), the images of plasma taken in laboratory electric discharges -- tokamaks, Z-pinches, plasma focus and vacuum spark (10^{-2} - 10 cm), hail particles (1-10 cm), the images of tornado (10^3 - 10^5 cm), the Hubble Space Telescope and Chandra X-Ray Observatory public archives' images (up to 10^23 cm). The redshift surveys of galaxies and quasars suggests the possibility to draw the above similarity farther, up to 10^26 cm. The above similarity hints at the presence of a baryonic cold dark skeleton (BCDS) of the Universe, which -- in the entire range 10^{-5} - 10^26 cm -- may contain ordinary matter in a fractal condensed form like that in the above-mentioned dust skeletons and hail particles. The probable compatibility of the BCDS with the major cosmological facts (Hubble's expansion and cosmic microwave background) is suggested. Our former hypotheses (and the respective proof-of-concept studies) for the probable microscopic mechanisms of skeleton's assembling, chemical composition, and survivability in ambient hot plasmas are discussed briefly. The respective major cosmological implication is that the purely gravitational description of the large-scale structure of the Universe is likely to be appended with a contribution of quantum electromagnetism, presumably in the form of a skeleton self-assembled from tubular nanostructures (carbon nanotubes or similar nanostructures of other chemical elements).

  8. Performance Calculations of APPLE II Undulator

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 TheSteven AshbyDepartment ofGE's Manual3 Short-Period APPLE II

  9. The E166 Experiment: Undulator-Based Production of Polarized Positrons

    SciTech Connect (OSTI)

    Schuler, K.Peter; /DESY

    2007-10-29T23:59:59.000Z

    A proof-of-principle experiment has been carried out in the Final Focus Test Beam (FFTB) at SLAC to demonstrate production of polarized positrons in a manner suitable for implementation at the ILC. A helical undulator of 2.54 mm period and 1-m length produced circularly polarized photons of first harmonic endpoint energy of 8 MeV when traversed by a 46.6 GeV electron beam. The polarized photons were converted to polarized positrons in a 0.2-radiation-length tungsten target. The polarization of these positrons was measured at several energies, with a peak value of {approx} 80% according to a preliminary analysis of the transmission polarimetry of photons obtained on reconversion of the positrons in a second tungsten target.

  10. The E166 Experiment: Undulator-Based Production of Polarized Positrons

    SciTech Connect (OSTI)

    Schueler, K. Peter [DESY, D-22607 Hamburg (Germany)

    2008-02-06T23:59:59.000Z

    A proof-of-principle experiment has been carried out in the Final Focus Test Beam (FFTB) at SLAC to demonstrate production of polarized positrons in a manner suitable for implementation at the ILC. A helical undulator of 2.54 mm period and 1-m length produced circularly polarized photons of first harmonic endpoint energy of 8 MeV when traversed by a 46.6 GeV electron beam. The polarized photons were converted to polarized positrons in a 0.2-radiation-length tungsten target. The polarization of these positrons was measured at several energies, with a peak value in excess of 80%, by transmission polarimetry of photons obtained on reconversion of the positrons in a second tungsten target.

  11. HYBRID UNDULATORS AND WIGGLERS LS-18 S.H. Kim

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky9, 2010 The meeting wasEngineering andHQHSIHYBRID UNDULATORS AND

  12. X-ray intensity interferometer for undulator radiation

    SciTech Connect (OSTI)

    Gluskin, E.; McNulty, I.; Viccaro, P.J. [Argonne National Lab., IL (United States); Howells, M.R. [Lawrence Berkeley Lab., CA (United States)

    1991-12-31T23:59:59.000Z

    Intensity interferometry is well established with visible light but has never been demonstrated with x-radiation. We propose to measure the transverse coherence of an x-ray beam, for the first time, using the method of Hanbury Brown and Twiss. The x-ray interferometer consists of an array of slits, a grazing incidence reflective beamsplitter, a pair of fast multichannel plate detectors and a broadband, low-noise correlator circuit. The NSLS X1 or X13 soft x-ray undulator will supply the partially coherent x-rays. We are developing this technique to characterize the coherence properties of x-ray beams from high brilliance insertion devices at third-generation synchrotron light facilities such as the Advanced Photon Source and the Advanced Light Source. 17 refs.

  13. X-ray intensity interferometer for undulator radiation

    SciTech Connect (OSTI)

    Gluskin, E.; McNulty, I.; Viccaro, P.J. (Argonne National Lab., IL (United States)); Howells, M.R. (Lawrence Berkeley Lab., CA (United States))

    1991-01-01T23:59:59.000Z

    Intensity interferometry is well established with visible light but has never been demonstrated with x-radiation. We propose to measure the transverse coherence of an x-ray beam, for the first time, using the method of Hanbury Brown and Twiss. The x-ray interferometer consists of an array of slits, a grazing incidence reflective beamsplitter, a pair of fast multichannel plate detectors and a broadband, low-noise correlator circuit. The NSLS X1 or X13 soft x-ray undulator will supply the partially coherent x-rays. We are developing this technique to characterize the coherence properties of x-ray beams from high brilliance insertion devices at third-generation synchrotron light facilities such as the Advanced Photon Source and the Advanced Light Source. 17 refs.

  14. Linac Coherent Light Source Undulator RF BPM System

    SciTech Connect (OSTI)

    Lill, R.M.; Morrison, L.H.; Waldschmidt, G.J.; Walters, D.R.; /Argonne; Johnson, R.; Li, Z.; Smith, S.; Straumann, T.; /SLAC

    2007-04-17T23:59:59.000Z

    The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL) when it becomes operational in 2009. The LCLS is currently in the construction phase. The beam position monitor (BPM) system planned for the LCLS undulator will incorporate a high-resolution X-band cavity BPM system described in this paper. The BPM system will provide high-resolution measurements of the electron beam trajectory on a pulse-to-pulse basis and over many shots. The X-band cavity BPM size, simple fabrication, and high resolution make it an ideal choice for LCLS beam position detection. We will discuss the system specifications, design, and prototype test results.

  15. Undulator-Based Laser Wakefield Accelerator Electron Beam Energy Spread and Emittance Diagnostic

    SciTech Connect (OSTI)

    Bakeman, M.S.; Van Tilborg, J.; Nakamura, K.; Gonsalves, A.; Osterhoff, J.; Sokollik, T.; Lin, C.; Robinson, K.E.; Schroeder, C.B.; Toth, Cs.; Weingartner, R.; Gruner, F.; Esarey, E.; Leemans, W.P.

    2010-06-01T23:59:59.000Z

    The design and current status of experiments to couple the Tapered Hybrid Undulator (THUNDER) to the Lawrence Berkeley National Laboratory (LBNL) laser plasma accelerator (LPA) to measure electron beam energy spread and emittance are presented.

  16. LS Note 339 - Calculated Shims' Signatures with the 17.2 mm Period New Undulator

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

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  17. LS Note 340 - New Design for a 27-mm Period Undulator for the MBA Lattice

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011 LOS ALAMOS, NewattractsDamping of

  18. Experiment on suppression of spontaneous undulator radiation at ATF

    SciTech Connect (OSTI)

    Litvinenko,V.; Yakimenko, V.

    2009-08-23T23:59:59.000Z

    We propose undertaking a demonstration experiment on suppressing spontaneous undulator radiation from an electron beam at BNL's Accelerator Test Facility (ATF). We describe the method, the proposed layout, and a possible schedule. There are several advantages in strongly suppressing shot noise in the electron beam, and the corresponding spontaneous radiation. The self-amplified spontaneous (SASE) emission originating from shot noise in the electron beam is the main source of noise in high-gain FEL amplifiers. It may negatively affect several HG FEL applications ranging from single- to multi-stage HGHG FELs. SASE saturation also imposes a fundamental hard limit on the gain of an FEL amplifier in a coherent electron-cooling scheme. A novel active method for suppressing shot noise in relativistic electron beams by many orders-of-magnitude was recently proposed. While theoretically such strong suppression appears feasible, the performance and applicability of this novel method must be evaluated experimentally. Several practical questions about the proposed noise suppressor, such as 3D effects and/or sensitivity to the e-beam parameters also require experimental clarification. To do this, we propose here a proof-of-principle experiment using elements of the VISA FEL at BNL's Accelerator Test Facility.

  19. A synchrotron X-ray study of competing undulation and electrostatic interlayer interactions in fluid multimembrane lyotropic phases

    E-Print Network [OSTI]

    Boyer, Edmond

    arise from attrac- tive electrodynamic van der Waals and, normally repulsive electrostatic forces [2307 A synchrotron X-ray study of competing undulation and electrostatic interlayer interactions of competing electrostatic and undulation forces in two multimembrane systems in the lamellar L03B1 phase

  20. Prototype photon position monitors for undulator beams at the Advanced Light Source

    SciTech Connect (OSTI)

    Warwick, T.; Shu, D. (Lawrence Berkeley Lab., CA (United States)); Rodricks, B. (Argonne National Lab., IL (United States)); Johnson, E.D. (Brookhaven National Lab., Upton, NY (United States))

    1990-10-17T23:59:59.000Z

    Design criteria are described, and test results are presented, for prototype ALS undulator beam position monitors. The design is based on monitors presently in use at NSLS, with modifications to account for the widely varying and large K values of the undulators to be installed at the ALS. In particular, we have modified the design to simplify the thermal engineering and we have explored techniques to suppress the response of the monitors to soft photons, so that the beam position can be determined by measuring the higher energy photons which are better collimated. 4 refs., 8 figs.

  1. Energy Loss and Energy Spread Growth in a Planar Undulator(LCC-0086)

    SciTech Connect (OSTI)

    Sheppard, J

    2003-10-07T23:59:59.000Z

    The change in beam energy spread due to transmission through a long, planar undulator is calculated. This change is shown to be gaussian as expected from the central limit theorem and large number of photons emitted per electron. These results are compared with Saldin et al. [2] expressions. Numerical results for the case of the TESLA beam and for an NLC beam are given.

  2. NOVEL CHAMBER DESIGN FOR AN IN-VACUUM CRYO-COOLED MINI-GAP UNDULATOR.

    SciTech Connect (OSTI)

    HU, J.-P.; FOERSTER, C.L.; SKARITKA, J.R.; WATERMAN, D.

    2006-05-24T23:59:59.000Z

    A stainless steel, Ultra-High Vacuum (UHV) chamber, featuring a large vertical rectangular port (53''W by 16''H), has been fabricated to house the one-meter magnet assembly of a newly installed undulator insertion device for beamline X-25 at the National Synchrotron Light Source. To achieve UHV, the new chamber is equipped with a differential ion pump, NEG pump, nude ion gauge, residual gas analyzer, and an all metal roughing valve. Temperature of the magnet assembly is maintained below 90 C during vacuum bake. The large rectangular port cover is sealed to the main flange of the chamber using a one-piece flat aluminum gasket and special sealing surfaces developed exclusively by Nor-Cal Products, Inc. The large flange provides easy access to the gap of the installed magnet girders for in situ magnetic measurements and shimming. Special window ports were designed into the cover and chamber for manipulation of optical micrometers external to the chamber to provide precise measurements of the in-vacuum magnet gap. The vacuum chamber assembly features independently vacuum-isolated feedthroughs that can be used for either water-or-cryogenic refrigeration-cooling of the monolithic magnet girders. This would allow for cryogenic-cooled permanent magnet operation and has been successfully tested within temperature range of +100 C to -150 C. Details of the undulator assembly for beamline X-25 is described in the paper.

  3. Statistical properties of the radiation from SASE FEL operating in a post-saturation regime with and without undulator tapering

    E-Print Network [OSTI]

    Schneidmiller, E A

    2015-01-01T23:59:59.000Z

    We describe statistical and coherence properties of the radiation from x-ray free electron lasers (XFEL) operating in the post-saturation regime. We consider practical case of the SASE3 FEL at the European XFEL. We perform comparison of the main characteristics of the X-ray FEL operating in the post-saturation regime with and without undulator tapering: efficiency, coherence time and degree of transverse coherence.

  4. Storm Water Analytical Period

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

    Storm Water Analytical Period Storm Water Analytical Period The Individual Permit authorizes the discharge of storm water associated with historical industrial activities at LANL...

  5. Design of the commissioning filter/mask/window assembly for undulator beamline front ends at the Advanced Photon Source

    SciTech Connect (OSTI)

    Shu, D.; Kuzay, T.M.

    1995-10-20T23:59:59.000Z

    A compact filter/mask/window assembly has been designed for undulator beamline commissioning activity at the Advanced Photon Source beamlines. The assembly consists of one 300-{mu}m graphite filter, one 127-{mu}m CVD diamond filter and two 250-{mu}m beryllium windows. A water-cooled Glidcop fixed mask with a 4.5-mm {times} 4.5-mm output optical aperture and a 0.96-mrad {times} 1.6-mrad beam missteering acceptance is a major part in the assembly. The CVD diamond filter which is mounted on the downstream side of the fixed mask is designed to also function as a transmitting x-ray beam position monitor. The sum signal from the latter can be used to monitor the physical condition of the graphite filter and prevent any possible chain reaction damage to the beryllium windows downstream. In this paper, the design concept as well as the detailed structural design of the commissioning window are presented. Further applications of the commissioning window commissioning window components are also discussed.

  6. Monte Carlo Studies of the Radiation Fields in the Linac Coherent Light Source Undulators and of the Corresponding Signals in the Cerenkov Beam Loss Monitors

    SciTech Connect (OSTI)

    Santana Leitner, Mario

    2010-09-14T23:59:59.000Z

    In 2009 the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Center started free electron laser (FEL) operation. In order to continue to produce the bright and short-pulsed x-ray laser demanded by FEL scientists, this pioneer hard x-ray FEL requires a perfectly tailored magnetic field at the undulators, so that the photons generated at the electron wiggling path interact at the right phase with the electron beam. In such a precise system, small (>0.01%) radiation-induced alterations of the magnetic field in the permanent magnets could affect FEL performance. This paper describes the simulation studies of radiation fields in permanent magnets and the expected signal in the detectors. The transport of particles from the radiation sources (i.e. diagnostic insert) to the undulator magnets and to the beam loss monitors (BLM) was simulated with the intra nuclear cascade codes FLUKA and MARS15. In order to accurately reproduce the optics of LCLS, lattice capabilities and magnetic fields were enabled in FLUKA and betatron oscillations were validated against reference data. All electron events entering the BLMs were printed in data files. The paper also introduces the Radioactive Ion Beam Optimizer (RIBO) Monte Carlo 3-D code, which was used to read from the event files, to compute Cerenkov production and then to simulate the optical coupling of the BLM detectors, accounting for the transmission of light through the quartz.

  7. LCLS Protype Undulator Report

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample Environment: Magnet and6 th7525T HE FLCLSLCLS Prep

  8. The Properties of Undulator Radiation

    E-Print Network [OSTI]

    Howells, M.R.

    2011-01-01T23:59:59.000Z

    of a Dedicated Synchrotron Radiation Facility," IEEE Trans.1983), "Characteristics of Synchrotron Radiation and of itsHandbook on Synchrotron Radiation, E. -E. Koch.1A. 65-172,

  9. LCLS CDR Chapter 8 - Undulator

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample Environment: Magnet and6 th7525T HE F IRSTA3 34 424578

  10. Down hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)

    1989-01-01T23:59:59.000Z

    A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  11. Advanced downhole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)

    1991-07-16T23:59:59.000Z

    An advanced downhole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  12. Clean-in-Place and Reliability Testing of a Commercial 12.5 cm Annular Centrifugal Contactor at the INL

    SciTech Connect (OSTI)

    N. R. Mann; T. G. Garn; D. H. Meikrantz; J. D. Law; T. A. Todd

    2007-09-01T23:59:59.000Z

    The renewed interest in advancing nuclear energy has spawned the research of advanced technologies for recycling nuclear fuel. A significant portion of the advanced fuel cycle includes the recovery of selected actinides by solvent extraction methods utilizing centrifugal contactors. Although the use of centrifugal contactors for solvent extraction is widely known, their operation is not without challenges. Solutions generated from spent fuel dissolution contain unknown quantities of undissolved solids. A majority of these solids will be removed via various methods of filtration. However, smaller particles are expected to carry through to downstream solvent extraction processes and equipment. In addition, solids/precipitates brought about by mechanical or chemical upsets are another potential area of concern. During processing, particulate captured in the rotor assembly by high centrifugal forces eventually forms a cake-like structure on the inner wall introducing balance problems and negatively affecting phase separations. One of the features recently developed for larger engineering scale Annular Centrifugal Contactors (ACCs) is the Clean-In-Place (CIP) capability. Engineered spray nozzles were installed into the hollow central rotor shaft in all four quadrants of the rotor assembly. This arrangement allows for a very convenient and effective method of solids removal from within the rotor assembly.

  13. Clean-in-Place and Reliability Testing of a Commercial 12.5-cm Annular Centrifugal Contactor at the INL

    SciTech Connect (OSTI)

    N. R. Mann; T. G. Garn; D. H. Meikrantz; J. D. Law; T. A. Todd

    2007-09-01T23:59:59.000Z

    The renewed interest in advancing nuclear energy has spawned the research of advanced technologies for recycling nuclear fuel. A significant portion of the advanced fuel cycle includes the recovery of selected actinides by solvent extraction methods utilizing centrifugal contactors. Although the use of centrifugal contactors for solvent extraction is widely known, their operation is not without challenges. Solutions generated from spent fuel dissolution contain unknown quantities of undissolved solids. A majority of these solids will be removed via various methods of filtration. However, smaller particles are expected to carry through to downstream solvent extraction processes and equipment. In addition, solids/precipitates brought about by mechanical or chemical upsets are another potential area of concern. During processing, particulate captured in the rotor assembly by high centrifugal forces eventually forms a cake-like structure on the inner wall introducing balance problems and negatively affecting phase separations. One of the features recently developed for larger engineering scale Annular Centrifugal Contactors (ACCs) is the Clean-In-Place (CIP) capability. Engineered spray nozzles were installed into the hollow central rotor shaft in all four quadrants of the rotor assembly. This arrangement allows for a very convenient and effective method of solids removal from within the rotor assembly.

  14. Compact betatron with four controlling-field periodicity elements

    SciTech Connect (OSTI)

    Chakhlov, V.L.; Pushin, V.S.; Burov, G.I.; Zvontsov, A.A.; Zvorygin, V.P.; Zrelov, Yu.D.

    1987-01-01T23:59:59.000Z

    A compact 3-MeV betatron is described. The electromagnet of the betatron uses removable four-element poles, which form a magnetic field with azimuthal variation. The betatron accelerates 2 x 10/sup 10/ particles per cycle. The cycle repetition frequency is up to 400 Hz. The radius of the equilibrium orbit is 4.5 cm. The maximum interpole gap is 4 cm. The depth of magnetic-field variation on the equilibrium radius is 0.15.

  15. Seismic isolation of two dimensional periodic foundations

    SciTech Connect (OSTI)

    Yan, Y.; Mo, Y. L., E-mail: yilungmo@central.uh.edu [University of Houston, Houston, Texas 77004 (United States); Laskar, A. [Indian Institute of Technology Bombay, Powai, Mumbai (India); Cheng, Z.; Shi, Z. [Beijing Jiaotong University, Beijing (China); Menq, F. [University of Texas, Austin, Texas 78712 (United States); Tang, Y. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2014-07-28T23:59:59.000Z

    Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5?Hz to 50?Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.

  16. Metallurgy Department Progress Report for the Period

    E-Print Network [OSTI]

    Dlcfc^ooWS imsm "-"' Metallurgy Department Progress Report for the Period 1 January to 31 December 1962 (Uw National Laboratory, DK-4000 Roskilde, Denmark July 1963 #12;Ris-R-486 METALLURGY DEPARTMENT PROGRESS REPORT FOR THE PERIOD 1 JANUARY TO 31 DECEMBER 1982 Abstract. The activities of the Metallurgy

  17. Broadband solar absorption enhancement via periodic

    E-Print Network [OSTI]

    Province, 230009, P. R. China. Solution processed colloidal quantum dot (CQD) solar cells have greatBroadband solar absorption enhancement via periodic nanostructuring of electrodes Michael M. Adachi demonstrate a bottom- illuminated periodic nanostructured CQD solar cell that enhances broadband absorption

  18. DEVELOPMENT OF RASASASTRA IN MEDIEVAL PERIOD*

    E-Print Network [OSTI]

    Harishankar Sharma

    1984-01-01T23:59:59.000Z

    ABSTRACT: The paper deals with the historical development of Rasasastra in Medieval period. Knowledge of Rasa has been in existence from the time immemorial. Exploration of natural resources for the benefit of human beings is the object of this therapy. It is a medical science recognized during vedic periods for the betterment of even Devas. Medieval period can be treated as a golden age for the development of this science. Looking at its aim and objects, methodology and therapeutics, it was recognized as a medical science with an independent philosophical background in 14 th century, by Madhavacharya in his Sarva Darsana Samgraha.

  19. Single-machine scheduling with periodic and exible periodic maintenance to minimize maximum tardiness

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    periods often appear in industry due to a machine breakdown (stochastic) or preventive maintenance of machine unavailability. However, in some cases (e.g. preventive maintenance), the maintenance of a machineSingle-machine scheduling with periodic and exible periodic maintenance to minimize maximum

  20. Analytical homogenization method for periodic composite materials

    E-Print Network [OSTI]

    Chen, Ying

    We present an easy-to-implement technique for determining the effective properties of composite materials with periodic microstructures, as well as the field distributions in them. Our method is based on the transformation ...

  1. Impact of Motor Failures on Payback Periods

    E-Print Network [OSTI]

    Cheek, K. F.; Pillay, P.; Dudley, K. J.

    This paper uses MotorMaster and Vaughen's Complete Price Guide to determine payback periods for different motor failure scenarios. Some scenarios considered are rewinds, reconditions, and replacement of bearings. Prices for these repairs...

  2. PARS II Process Document DOE Period Close

    Broader source: Energy.gov [DOE]

    This document details the process adopted by the Office of Acquisition and Project Management to prepare APM DepSec Monthly Status Report, finalize DOE close period package, and perform reporting...

  3. Periodic subsystem density-functional theory

    SciTech Connect (OSTI)

    Genova, Alessandro; Pavanello, Michele, E-mail: m.pavanello@rutgers.edu [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); Ceresoli, Davide [Department of Chemistry, Rutgers University, Newark, New Jersey 07102 (United States); CNR-ISTM, Institute of Molecular Sciences and Technologies, Milano (Italy)

    2014-11-07T23:59:59.000Z

    By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of KohnSham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with KohnSham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.

  4. Periodic Exponential Shear of Complex Fluids

    E-Print Network [OSTI]

    Chirag Kalelkar; Gareth McKinley

    2012-05-31T23:59:59.000Z

    We define a class of flows with exponential kinematics termed Periodic Exponential Shear (PES) flow which involve periodic exponential stretching of fluid elements along with their rotation. We exhibit analytical and numerical results for PES flow by using the Oldroyd-B model for viscoelastic fluids. We calculate the growth in the shear and the normal stresses analytically as well as demonstrate that repeated application of the flow leads to stable oscillatory shear and normal stresses. We define a material function applicable to a periodic, unsteady shear flow and show numerically that this material function exhibits deformation-rate thickening behavior for viscoelastic fluids subject to PES flow. We demonstrate the feasibility of PES flow by presenting preliminary experimental results from a controlled-strain rate rheometer, using a Newtonian mineral oil.

  5. Parc Periodical | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratorySpeedingOptimizingToolsto controlParc Periodical Parc Periodical

  6. Quantum transport calculations using periodic boundaryconditions

    SciTech Connect (OSTI)

    Wang, Lin-Wang

    2004-06-15T23:59:59.000Z

    An efficient new method is presented to calculate the quantum transports using periodic boundary conditions. This method allows the use of conventional ground state ab initio programs without big changes. The computational effort is only a few times of a normal groundstate calculations, thus is makes accurate quantum transport calculations for large systems possible.

  7. Identification for a Nonlinear Periodic Wave Equation

    SciTech Connect (OSTI)

    Morosanu, C. [Department of Mathematics, University 'Al.I.Cuza', 6600 Iasi (Romania); Trenchea, C. [Institute of Mathematics of Romanian Academy, 6600 Iasi (Romania)

    2001-07-01T23:59:59.000Z

    This work is concerned with an approximation process for the identification of nonlinearities in the nonlinear periodic wave equation. It is based on the least-squares approach and on a splitting method. A numerical algorithm of gradient type and the numerical implementation are given.

  8. Utility Building Analysis Billing Period: NOV -2013

    E-Print Network [OSTI]

    Ciocan-Fontanine, Ionut

    ELECTRICITY Consumption MUNICIPAL WATER Consumption 8 CCF STEAM Consumption CHILLED WATER Consumption GAS Building Analysis Billing Period: NOV - 2013 032 JACKSON HALL: 150,393 Square Feet ELECTRICITY Consumption,550 Square Feet ELECTRICITY Consumption 114,185 KWHRS MUNICIPAL WATER Consumption 1,423 CCF STEAM Consumption

  9. Coherency saturation in periodic structures with randomization

    E-Print Network [OSTI]

    Kaplan, Alexander

    ,28 or multicascade stimulated Raman scattering.29­31 A major example of naturally occurring spatially periodic with very reasonable precision. In the specific case of x ray transition radiation of low layers can generate resonantly enhanced radiation in the hard x ray domain with almost unhampered

  10. New Science with the APS Superconducting Undulator

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNational Libraryornl.gov Ron WalliANew ResearchYoung of XSD

  11. Chaotic Transport in Planar Periodic Vortical Flows

    E-Print Network [OSTI]

    Taehoon Ahn; Seunghwan Kim

    1993-09-24T23:59:59.000Z

    We have studied a chaotic transport in a two-dimensional periodic vortical flow under a time-dependent perturbation with period T where the global diffusion occurs along the stochastic web. By using the Melnikov method we construct the separatrix map describing the approximate dynamics near the saddle separatrices. Focusing on the small T, the width of the stochastic layer is calculated analytically by using the residue criterion and the diffusion constant by using the random phase assumption and correlated random walks. The analytical results are in good agreements with the results of two different types of numerical simulations by integrations of the Hamilton's equation of motion and by iterations of the separatrix map, which establishes the validity of the use of the separatrix map.

  12. Periodic-Orbit Theory of Level Correlations

    E-Print Network [OSTI]

    Stefan Heusler; Sebastian Mller; Alexander Altland; Petr Braun; Fritz Haake

    2006-10-20T23:59:59.000Z

    We present a semiclassical explanation of the so-called Bohigas-Giannoni-Schmit conjecture which asserts universality of spectral fluctuations in chaotic dynamics. We work with a generating function whose semiclassical limit is determined by quadruplets of sets of periodic orbits. The asymptotic expansions of both the non-oscillatory and the oscillatory part of the universal spectral correlator are obtained. Borel summation of the series reproduces the exact correlator of random-matrix theory.

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

    E-Print Network [OSTI]

    Antonio Mecozzi; Cristian Antonelli

    2008-12-11T23:59:59.000Z

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

  14. Policy Flash 2013-41 Contracts Periods of Performance Exceeding...

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

    41 Contracts Periods of Performance Exceeding 5 Years Policy Flash 2013-41 Contracts Periods of Performance Exceeding 5 Years Attached is Policy Flash 2013-41 Contracts Periods of...

  15. Application Periods Open for 2014 National Clean Energy Business...

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

    Application Periods Open for 2014 National Clean Energy Business Plan Competition's Regional Contests Application Periods Open for 2014 National Clean Energy Business Plan...

  16. DOE Extends Public Comment Period for the Draft Uranium Leasing...

    Office of Environmental Management (EM)

    Extends Public Comment Period for the Draft Uranium Leasing Program Programmatic Environmental Impact Statement DOE Extends Public Comment Period for the Draft Uranium Leasing...

  17. Down-hole periodic seismic generator

    DOE Patents [OSTI]

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

    1982-10-28T23:59:59.000Z

    A down hole periodic seismic generator system is disclosed for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  18. Property:TimePeriod | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revisionEnvReviewNonInvasiveExploration JumpSanyalTempWellhead Jump to:Technology ReadinessTimePeriod Jump to:

  19. On a periodicity measure and superoscillations

    E-Print Network [OSTI]

    Nehemia Schwartz; Moshe Schwartz

    2014-02-13T23:59:59.000Z

    The phenomenon of superoscillation, where band limited signals can oscillate over some time period with a frequency higher than the band limit, is not only very interesting but it also seems to offer many practical applications. The first reason is that the superoscillation frequency can be exploited to perform tasks beyond the limits imposed by the lower bandwidth of the signal. The second reason is that it is generic and applies to any wave form, be it optical, electrical, sonic, or quantum mechanical. For practical applications, it is important to overcome two problems. The first problem is that an overwhelming proportion of the energy goes into the non superoscillating part of the signal. The second problem is the control of the shape of the superoscillating part of the signal. The first problem has been recently addressed by optimization of the super oscillation yield, the ratio of the energy in the superoscillations to the total energy of the signal. The second problem may arise when the superoscillation, is to mimic a high frequency purely perodic signal. This may be required, for example, when a superoscillating force is to drive a harmonic oscillator at a high resonance frequency. In this paper the degree of periodicity of a signal is defined and applied to some yield optimized superoscillating signals.

  20. Periodic Cluster Mutations and Related Integrable Maps

    E-Print Network [OSTI]

    Allan P Fordy

    2014-03-31T23:59:59.000Z

    One of the remarkable properties of cluster algebras is that any cluster, obtained from a sequence of mutations from an initial cluster, can be written as a Laurent polynomial in the initial cluster (known as the "Laurent phenomenon"). There are many nonlinear recurrences which exhibit the Laurent phenomenon and thus unexpectedly generate integer sequences. The mutation of a typical quiver will not generate a recurrence, but rather an erratic sequence of exchange relations. How do we "design" a quiver which gives rise to a given recurrence? A key role is played by the concept of "periodic cluster mutation", introduced in 2009. Each recurrence corresponds to a finite dimensional map. In the context of cluster mutations, these are called "cluster maps". What properties do cluster maps have? Are they integrable in some standard sense? In this review I describe how integrable maps arise in the context of cluster mutations. I first explain the concept of "periodic cluster mutation", giving some classification results. I then give a review of what is meant by an integrable map and apply this to cluster maps. Two classes of integrable maps are related to interesting monodromy problems, which generate interesting Poisson algebras of functions, used to prove complete integrability and a linearisation. A connections to the Hirota-Miwa equation is explained.

  1. Electromagnetic Siegert states for periodic dielectric structures

    E-Print Network [OSTI]

    Friends R. Ndangali; Sergei V. Shabanov

    2011-08-09T23:59:59.000Z

    The formalism of Siegert states to describe the resonant scattering in quantum theory is extended to the resonant scattering of electromagnetic waves on periodic dielectric arrays. The excitation of electromagnetic Siegert states by an incident wave packet and their decay is studied. The formalism is applied to develop a theory of coupled electromagnetic resonances arising in the electromagnetic scattering problem for two such arrays separated by a distance 2h (or, generally, when the physical properties of the scattering array depend on a real coupling parameter h). Analytic properties of Siegert states as functions of the coupling parameter h are established by the Regular Perturbation Theorem which is an extension the Kato-Rellich theorem to the present case. By means of this theorem, it is proved that if the scattering structure admits a bound state in the radiation continuum at a certain value of the coupling parameter h, then there always exist regions within the structure in which the near field can be amplified as much as desired by adjusting the value of h. This establishes a rather general mechanism to control and amplify optical nonlinear effects in periodically structured planar structures possessing a nonlinear dielectric susceptibility.

  2. Periodic table for topological insulators and superconductors

    E-Print Network [OSTI]

    Alexei Kitaev

    2009-01-20T23:59:59.000Z

    Gapped phases of noninteracting fermions, with and without charge conservation and time-reversal symmetry, are classified using Bott periodicity. The symmetry and spatial dimension determines a general universality class, which corresponds to one of the 2 types of complex and 8 types of real Clifford algebras. The phases within a given class are further characterized by a topological invariant, an element of some Abelian group that can be 0, Z, or Z_2. The interface between two infinite phases with different topological numbers must carry some gapless mode. Topological properties of finite systems are described in terms of K-homology. This classification is robust with respect to disorder, provided electron states near the Fermi energy are absent or localized. In some cases (e.g., integer quantum Hall systems) the K-theoretic classification is stable to interactions, but a counterexample is also given.

  3. Steady periodic gravity waves with surface tension

    E-Print Network [OSTI]

    Samuel Walsh

    2009-11-06T23:59:59.000Z

    In this paper we consider two-dimensional, stratified, steady water waves propagating over an impermeable flat bed and with a free surface. The motion is assumed to be driven by capillarity (that is, surface tension) on the surface and a gravitational force acting on the body of the fluid. We prove the existence of global continua of classical solutions that are periodic and traveling. This is accomplished by first constructing a 1-parameter family of laminar flow solutions, $\\mathcal{T}$, then applying bifurcation theory methods to obtain local curves of small amplitude solutions branching from $\\mathcal{T}$ at an eigenvalue of the linearized problem. Each solution curve is then continued globally by means of a degree theoretic theorem in the spirit of Rabinowitz. Finally, we complement the degree theoretic picture by proving an alternate global bifurcation theorem via the analytic continuation method of Dancer.

  4. Fluorescence in nonlocal dissipative periodic structures

    E-Print Network [OSTI]

    Francesco Intravaia; Kurt Busch

    2015-02-24T23:59:59.000Z

    We present an approach for the description of fluorescence from optically active material embedded in layered periodic structures. Based on an exact electromagnetic Green's tensor analysis, we determine the radiative properties of emitters such as the local photonic density of states, Lamb shifts, line widths etc. for a finite or infinite sequence of thin alternating plasmonic and dielectric layers. In the effective medium limit, these systems may exhibit hyperbolic dispersion relations so that the large wave-vector characteristics of all constituents and processes become relevant. These include the finite thickness of the layers, the nonlocal properties of the constituent metals, and local-field corrections associated with an emitter's dielectric environment. In particular, we show that the corresponding effects are non-additive and lead to considerable modifications of an emitter's luminescence properties.

  5. Effects of periodic matter in kaon regeneration

    E-Print Network [OSTI]

    Evgeny Akhmedov; Augusto Barroso; Petteri Kernen

    2001-07-23T23:59:59.000Z

    We study the effects of periodic matter in kaon regeneration, motivated by the possibility of parametric resonance in neutrino oscillations. The large imaginary parts of the forward kaon-nucleon scattering amplitudes and the decay width difference $\\Delta\\Gamma$ prevent a sizable enhancement of the $K_L\\to K_S$ transition probability. However, some interesting effects can be produced using regenerators made of alternating layers of two different materials. Despite the fact that the regenerator has a fixed length one can obtain different values for the probability distribution of the $K_L$ decay into a final state. Using a two-arm regenerator set up it is possible to measure the imaginary parts of the $K^0(\\bar{K}^0)$-nucleon scattering amplitudes in the correlated decays of the $\\phi$-resonance. Combining the data of the single-arm regenerator experiments with direct and reverse orders of the matter layers in the regenerator one can independently measure the CP violating parameter $\\delta$.

  6. Superconvergence of period doubling cascade in trapezoid maps

    E-Print Network [OSTI]

    T. Uezu

    2000-01-12T23:59:59.000Z

    In the symmetric and the asymmetric trapezoid maps, as a slope of the trapezoid is increased, the period doubling cascade occurs and the symbolic sequence of periodic points is the Metropolis-Stein-Stein sequence and the convergence of the onset point of the period 2^m solution to the accumulation point is exponentially fast. We reported these results previously. In this paper, we give the detailed description of the proof on the results. Further, we study the period doubling cascade starting from period p solution and show the superconvergence of the period doubling cascade.

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

    Office of Environmental Management (EM)

    distributing and archiving of reports; and close period activities. PROCESS The Monthly Report and Close Period process starts on the 1 st working day of the reporting month. The...

  8. Period-luminosity and period-luminosity-colour relations for Mira variables at maximum light

    E-Print Network [OSTI]

    S. M. Kanbur; M. A. Hendry; D. Clarke

    1997-04-14T23:59:59.000Z

    In this paper we confirm the existence of period-luminosity (PL) and period-luminosity-colour (PLC) relations at maximum light for O and C Mira variables in the LMC. We demonstrate that in the J and H bands the maximum light PL relations have a significantly smaller dispersion than their counterparts at mean light, while the K band and bolometric PL relations have a dispersion comparable to that at mean light. In the J, H and K bands the fitted PL relations for the O Miras are found to have smaller dispersion than those for the C Miras, at both mean and maximum light, while the converse is true for the relations based on bolometric magnitudes. The inclusion of a non-zero log period term is found to be highly significant in all cases except that of the C Miras in the J band, for which the data are found to be consistent with having constant absolute magnitude. This suggests the possibility of employing C Miras as standard candles. We suggest both a theoretical justification for the existence of Mira PL relations at maximum light and a possible explanation of why these relations should have a smaller dispersion than at mean light. The existence of such maximum light relations offers the possibility of extending the range and improving the accuracy of the Mira distance scale to Galactic globular clusters and to other galaxies.

  9. Focusing-to-defocusing crossover in nonlinear periodic structures

    E-Print Network [OSTI]

    Focusing-to-defocusing crossover in nonlinear periodic structures Francis H. Bennet,* Inés A. Amuli

  10. Period of K system generator of pseudorandom numbers

    E-Print Network [OSTI]

    Akopov, N Z; Floratos, Emmanuel G; Savvidy, G K

    1996-01-01T23:59:59.000Z

    We analyze the structure of the periodic trajectories of the matrix generator of pseudorandom numbers which has been proposed earlier. The structure of the periodic trajectories becomes more transparent when the rational sublattice coincides with the Galois field GF[p]. We are able to compute the period of the trajectories as a function of p and the dimension of the matrix d.

  11. Period of K System Generator of Pseudorandom Numbers

    E-Print Network [OSTI]

    N. Z. Akopov; G. G. Athanasiu; E. G. Floratos; G. K. Savvidy

    1996-02-09T23:59:59.000Z

    We analyze the structure of the periodic trajectories of the matrix generator of pseudorandom numbers which has been proposed earlier. The structure of the periodic trajectories becomes more transparent when the rational sublattice coincides with the Galois field $GF[p]$. We are able to compute the period of the trajectories as a function of $p$ and the dimension of the matrix $d$.

  12. Quarterly Construction Status Report Period Ending: June 30, 2013

    E-Print Network [OSTI]

    Alpay, S. Pamir

    Quarterly Construction Status Report Period Ending: June 30, 2013 Storrs and Regional Campuses University of Connecticut Health Center Quarterly Construction Status Report for Period Ending: June 30, 2013 #12;Quarterly Construction Status Report Period Ending: June 30, 2013 Project Number Project Index

  13. Quarterly Construction Status Report Period Ending: March 31, 2014

    E-Print Network [OSTI]

    Alpay, S. Pamir

    Quarterly Construction Status Report Period Ending: March 31, 2014 Storrs and Regional Campuses University of Connecticut Health Center Quarterly Construction Status Report for Period Ending: March 31, 2014 #12;Quarterly Construction Status Report Period Ending: March 31, 2014 Project Number Project

  14. Can Bohmian trajectories account for quantum recurrences having classical periodicities?

    E-Print Network [OSTI]

    A. Matzkin

    2006-07-14T23:59:59.000Z

    Quantum systems in specific regimes display recurrences at the period of the periodic orbits of the corresponding classical system. We investigate the excited hydrogen atom in a magnetic field -- a prototypical system of 'quantum chaos' -- from the point of view of the de Broglie Bohm (BB) interpretation of quantum mechanics. The trajectories predicted by BB theory are computed and contrasted with the time evolution of the wavefunction, which shows pronounced features at times matching the period of closed orbits of the classical hydrogen in a magnetic field problem. Individual BB trajectories do not possess these periodicities and cannot account for the quantum recurrences. These recurrences can however be explained by BB theory by considering the ensemble of trajectories compatible with an initial statistical distribution, although none of the trajectories of the ensemble are periodic, rendering unclear the dynamical origin of the classical periodicities.

  15. Green's function analysis of periodic structures in computational electromagnetics

    E-Print Network [OSTI]

    Van Orden, Derek

    2011-01-01T23:59:59.000Z

    the two-dimensional periodic Green's function," IEEE Trans.evaluation of the Green's function for the Helmholtzrepresentations of certain Green's functions," J. Comp.

  16. EIS-0250: Notice of Public Comment Period Extension and Additional...

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

    Period Extension and Additional Public Meeting Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, NV...

  17. EIS-0369: Notice of Public Comment Period Extension and Additional...

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

    Notice of Public Comment Period Extension and Additional Public Meeting Supplemental Yucca Mountain Rail Corridor and Rail Alignment The Department of Energy is now announcing...

  18. Uranium Leasing Program Draft PEIS Public Comment Period Extended...

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

    Uranium Leasing Program Draft PEIS Public Comment Period Extended to May 31, 2013 Draft ULPEIS comment extension community notification041813 (3).pdf More Documents & Publications...

  19. Guidance on the Required Period for Grantees to Obligate Funds...

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

    Funds and the Procedures for Reporting of Obligated Funds for the Energy Efficiency Conservation Block Grant (EECBG) Program Guidance on the Required Period for Grantees to...

  20. EIS-0431: Extension of Public Comment Period | Department of...

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

    Comment Period Hydrogen Energy California's Integrated Gasification Combined Cycle and Carbon Capture and Sequestration Project, CA The U.S. Department of Energy (DOE) published...

  1. Quality of Monitoring of Stochastic Events by Periodic and ...

    E-Print Network [OSTI]

    2008-12-09T23:59:59.000Z

    be periodically turned off to conserve energy, thereby ... such as chemical, biological, nuclear, radiational, .... ited/offset by the latency and energy costs of turn-.

  2. CV evolution: AM Her binaries and the period gap

    E-Print Network [OSTI]

    R. F. Webbink; D. T. Wickramasinghe

    2002-04-19T23:59:59.000Z

    AM Her variables -- synchronised magnetic cataclysmic variables (CVs) -- exhibit a different period distribution from other CVs across the period gap. We show that non-AM Her systems may infiltrate the longer-period end of the period gap if they are metal-deficient, but that the position and width of the gap in orbital period is otherwise insensitive to other binary parameters (excepting the normalisation of the braking rate). In AM Her binaries, magnetic braking is reduced as the wind from the secondary star may be trapped within the magnetosphere of the white dwarf primary. This reduced braking fills the period gap from its short-period end as the dipole magnetic moment of the white dwarf increases. The consistency of these models with the observed distribution of CVs, both AM Her and non-AM Her type, provides compelling evidence supporting magnetic braking as the agent of angular momentum loss among long-period CVs, and its disruption as the explanation of the 2 - 3 hour period gap among nonmagnetic CVs.

  3. Extension of Comment Period on the Draft Integrated, Interagency...

    Energy Savers [EERE]

    Extension of Comment Period on the Draft Integrated, Interagency Pre-Application (IIP) Process for Electric Transmission Projects Requiring Federal Authorizations Extension of...

  4. Dual periodicities in the rotational modulation of Saturn narrowband emissions

    E-Print Network [OSTI]

    Gurnett, Donald A.

    Dual periodicities in the rotational modulation of Saturn narrowband emissions S.Y. Ye,1 D. A emissions is examined, restricting the spacecraft location to either the northern or the southern hemisphere of Saturn. It is found that in both hemispheres, the modulation period of 5 kHz narrowband emissions has two

  5. Quantum coherent switch utilizing commensurate nanoelectrode and charge density periodicities

    DOE Patents [OSTI]

    Harrison, Neil (Santa Fe, NM); Singleton, John (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

    2008-08-05T23:59:59.000Z

    A quantum coherent switch having a substrate formed from a density wave (DW) material capable of having a periodic electron density modulation or spin density modulation, a dielectric layer formed onto a surface of the substrate that is orthogonal to an intrinsic wave vector of the DW material; and structure for applying an external spatially periodic electrostatic potential over the dielectric layer.

  6. Another look at periodic wavelets Brody Dylan Johnson

    E-Print Network [OSTI]

    Johnson, Brody Dylan

    Another look at periodic wavelets Brody Dylan Johnson St. Louis University 16 May 2009 Brody Dylan Johnson (St. Louis University) Another look at periodic wavelets 16 May 2009 1 / 31 #12;Overview Overview. (see, e.g., the texts of Meyer and Daubechies) Brody Dylan Johnson (St. Louis University) Another look

  7. Phase-locked rhythms in periodically stimulated heart cell aggregates

    E-Print Network [OSTI]

    Glass, Leon

    Phase-locked rhythms in periodically stimulated heart cell aggregates MICHAEL R. GUEVARA, ALVIN GUEVARA,MICHAEL R., ALVIN SHRIER,ANDLEONGLASS. Phase-locked rhythms in periodically stimulated heart cell, THE SINOATRIAL NODE acts as the pace- maker of the heart. As a result of the orderly spread of excitation

  8. Insecticides and my Osmia cornifrons Nesting Container Nesting Period

    E-Print Network [OSTI]

    Insecticides and my Osmia cornifrons Nesting Container Nesting Period The Osmia cornifrons nesting male offspring. The end caps of nesting tubes made by older females are thin and weak, and they tend to break easily. In addition, near the end of the nesting period the numbers of parasites and predators

  9. TIME-PERIODIC SOUND WAVE PROPAGATION COMPRESSIBLE EULER EQUATIONS

    E-Print Network [OSTI]

    A PARADIGM FOR TIME-PERIODIC SOUND WAVE PROPAGATION IN THE COMPRESSIBLE EULER EQUATIONS BLAKE consistent with time-periodic sound wave propagation in the 3 ? 3 nonlinear compressible Euler equations description of shock-free waves that propagate through an oscillating entropy field without breaking or dis

  10. On the Mass-Period Correlation of the Extrasolar Planets

    E-Print Network [OSTI]

    Shay Zucker; Tsevi Mazeh

    2002-02-22T23:59:59.000Z

    We report on a possible correlation between the masses and periods of the extrasolar planets, manifested as a paucity of massive planets with short orbital periods. Monte-Carlo simulations show the effect is significant, and is not solely due to an observational selection effect. We also show the effect is stronger than the one already implied by published models that assumed independent power-law distributions for the masses and periods of the extrasolar planets. Planets found in binary stellar systems may have an opposite correlation. The difference is highly significant despite the small number of planets in binary systems. We discuss the paucity of short-period massive planets in terms of some theories for the close-in giant planets. Almost all models can account for the deficit of massive planets with short periods, in particular the model that assumes migration driven by a planet-disk interaction, if the planet masses do not scale with their disk masses.

  11. Planar resonant periodic orbits in Kuiper belt dynamics

    E-Print Network [OSTI]

    George Voyatzis; Thomas Kotoulas

    2005-02-28T23:59:59.000Z

    In the framework of the planar restricted three body problem we study a considerable number of resonances associated to the Kuiper Belt dynamics and located between 30 and 48 a.u. Our study is based on the computation of resonant periodic orbits and their stability. Stable periodic orbits are surrounded by regular librations in phase space and in such domains the capture of trans-Neptunian object is possible. All the periodic orbits found are symmetric and there is evidence for the existence of asymmetric ones only in few cases. In the present work first, second and third order resonances are under consideration. In the planar circular case we found that most of the periodic orbits are stable. The families of periodic orbits are temporarily interrupted by collisions but they continue up to relatively large values of the Jacobi constant and highly eccentric regular motion exists for all cases. In the elliptic problem and for a particular eccentricity value of the primary bodies the periodic orbits are isolated. The corresponding families, where they belong to, bifurcate from specific periodic orbits of the circular problem and seem to continue up to the rectilinear problem. Both stable and unstable orbits are obtained for each case. In the elliptic problem the unstable orbits found are associated with narrow chaotic domains in phase space. The evolution of the orbits, which are located in such chaotic domains, seems to be practically regular and bounded for long time intervals.

  12. Optimization models for improving periodic maintenance schedules by utilizing opportunities

    E-Print Network [OSTI]

    Patriksson, Michael

    to this as preventive maintenance activities at an oppor- tunity. The original opportunistic replacement problemOptimization models for improving periodic maintenance schedules by utilizing opportunities Torgny of Technology Abstract We present mathematical models for finding optimal opportunistic maintenance schedules

  13. Total Estimated Contract Cost: Performance Period Total Fee Paid

    Office of Environmental Management (EM)

    FY2011 FY2012 Fee Information Minimum Fee Maximum Fee September 2014 Contract Number: Cost Plus Incentive Fee Contractor: 3,260,603,765 Contract Period: EM Contractor Fee Site:...

  14. Total Estimated Contract Cost: Performance Period Total Fee Paid

    Office of Environmental Management (EM)

    Wastren-EnergX Mission Support LLC Contract Number: DE-CI0000004 Contract Type: Cost Plus Award Fee 128,879,762 Contract Period: December 2009 - July 2015 Fee Information...

  15. Total Estimated Contract Cost: Performance Period Total Fee Paid

    Office of Environmental Management (EM)

    - September 2015 September 2014 Contractor: Contract Number: Contract Type: Idaho Treatment Group LLC DE-EM0001467 Cost Plus Award Fee Fee Information 444,161,295 Contract Period:...

  16. Total Estimated Contract Cost: Performance Period Total Fee Paid

    Office of Environmental Management (EM)

    Cumulative Fee Paid 22,200,285 Wackenhut Services, Inc. DE-AC30-10CC60025 Contractor: Cost Plus Award Fee 989,000,000 Contract Period: Contract Type: January 2010 - December...

  17. Total Estimated Contract Cost: Performance Period Total Fee Paid

    Office of Environmental Management (EM)

    Number: Contract Type: Contract Period: 0 Minimum Fee Maximum Fee Washington River Protection Solutions LLC DE-AC27-08RV14800 Cost Plus Award Fee 5,553,789,617 Fee Information...

  18. Total Estimated Contract Cost: Performance Period Total Fee Paid

    Office of Environmental Management (EM)

    & Wilcox Conversion Services, LLC Contract Number: DE-AC30-11CC40015 Contract Type: Cost Plus Award Fee Fee Available 4,324,912 408,822,369 Contract Period: December 2010 -...

  19. Variable Selection and Inference for Multi-period Forecasting Problems

    E-Print Network [OSTI]

    Pesaran, M Hashem; Pick, Andreas; Timmermann, Allan

    Variable Selection and Inference for Multi-period Forecasting Problems? M. Hashem Pesaran Cambridge University and USC Andreas Pick De Nederlandsche Bank and Cambridge University, CIMF Allan Timmermann UC San Diego and CREATES January 26, 2009...

  20. Dynamic Scheduling of Skippable Periodic Tasks: Issues and Proposals

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -Chetto and Audrey Marchand IRCCyN, University of Nantes, Nantes, FRANCE Email: {maryline.chetto, audrey.marchand Scheduling of Skippable Periodic Tasks in Weakly-Hard Real-Time Systems," by M. Silly-Chetto, and A. Marchand

  1. activity rules periodic: Topics by E-print Network

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

    WITH PERIODIC ACTIVE THERMAL IMAGING Physics Websites Summary: methods where the thermal evolution of a scene is recorded while some external time varying energyIMPACT OF A LOSSY...

  2. Periodic solutions of Schrodinger equation in Hilbert space

    E-Print Network [OSTI]

    A. A. Boichuk; A. A. Pokutnyi

    2012-09-03T23:59:59.000Z

    Necessary and sufficient conditions for existence of boundary value problem of Schrodinger equation are obtained in linear and nonlinear cases. Periodic analytical solutions are represented using generalized Green's operator

  3. CEQ Extends Comment Period on Revised Draft Guidance on Consideration...

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

    draft guidance on consideration of greenhouse gas (GHG) emissions and the effects of climate change in NEPA reviews. The comment period now ends on March 25, 2015. The revised...

  4. Thermal equilibrium theory of periodically focused charged-particle beams

    E-Print Network [OSTI]

    Samokhvalova, Ksenia R

    2008-01-01T23:59:59.000Z

    A thermal equilibrium theory of periodically focused charged-particle beams is presented in the framework of both warm-fluid and kinetic descriptions. In particular, the thermal beam equilibria are discussed for paraxial ...

  5. Microsoft Word - DOE News Release - Public Comment Period Extended...

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

    Period on Proposed Cleanup Plans Extended 60 Days On Oct. 31, 2014 the U.S. Department of Energy (DOE) released two formal Proposed Plans for the decontamination and...

  6. Wave propagation in periodic lattices with defects of smaller dimension

    E-Print Network [OSTI]

    A. A. Kutsenko

    2013-05-20T23:59:59.000Z

    The procedure of evaluating of the spectrum for discrete periodic operators perturbed by operators of smaller dimensions is obtained. This result allows to obtain propagative, guided, localised spectra for different kind of physical operators on graphs with defects.

  7. Short-period seismic rotations and translations recorded by Rotaphone

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    -period Rotaphone records of events induced by natural and/or anthropogenic sources 31 5.1 Records of quarry blasts Rotation to translation relations 39 7 The problem of seismic translational components being contaminated

  8. Realtime controller tuning for periodic disturbance rejection with application to active noise control

    E-Print Network [OSTI]

    Kinney, Charles E.

    2009-01-01T23:59:59.000Z

    de Callafon. Scheduling control for periodic disturbance at-de Callafon, Scheduling Control for Periodic DisturbanceR.A. de Callafon, Scheduling Control for Periodic Distur-

  9. An Autonomous Adaptive Scheduling Agent for Period Searching

    E-Print Network [OSTI]

    Eric S. Saunders; Tim Naylor; Alasdair Allan

    2008-01-24T23:59:59.000Z

    We describe the design and implementation of an autonomous adaptive software agent that addresses the practical problem of observing undersampled, periodic, time-varying phenomena using a network of HTN-compliant robotic telescopes. The algorithm governing the behaviour of the agent uses an optimal geometric sampling technique to cover the period range of interest, but additionally implements proactive behaviour that maximises the optimality of the dataset in the face of an uncertain and changing operating environment.

  10. Ultrasonic wave propagation in random and periodic particulate composites

    E-Print Network [OSTI]

    Henderson, Benjamin Kyle

    1996-01-01T23:59:59.000Z

    ULTRASONIC WAVE PROPAGATION IN RANDOM AND PERIODIC PARTICULATE COMPOSITES A Thesis by BENJAMIN KYLE HENDERSON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfilltnent of the requirements for the degree... of MASTER OF SCIENCE May 1996 Major Subject: Aerospace Engineering ULTRASONIC WAVE PROPAGATION IN RANDOM AND PERIODIC PARTICULATE COMPOSITES A Thesis by BENJAMIN KYLE HENDERSON Submitted to Texas ASM University in partial fulfillment...

  11. Observations of long period earthquakes accompanying hydraulic fracturing

    SciTech Connect (OSTI)

    Bame, D.; Fehler, M.

    1986-02-01T23:59:59.000Z

    Waveforms of most seismic events accompanying hydraulic fracturing have been reported to contain clear P and S waves and have fault plane solutions consistent with shear displacement across a fault. This observation is surprising since classical hydraulic fracturing theory predicts the creation of a tensile opening of a cavity in response to fluid pressure. Very small long period events, similar to long period earthquakes observed at volcanoes, were found to occur during four hydraulic fracturing experiments carried out at Fenton Hill, New Mexico. Since the long period earthquakes occur in the same region as the shear type events, it is concluded that the unusual character of the long period earthquake waveforms is due to a source effect and not a path effect. The occurrence of long period earthquakes during hydraulic fracturing could indicate tensile fracturing. Many waveforms of these events are identical, which implies that these events represent repeated activation of a given source. A proposed source for these long period events is the sudden opening of a channel that connects two cracks filled with fluid at different pressures. The sizes of the two cracks differ, which causes two or more peaks to appear in the spectra, each peak being associated with one physical dimension of each crack. From the frequencies at which spectral peaks occur, crack lengths are estimated to be between 3 and 20m.

  12. Prominence seismology using the period ratio of transverse thread oscillations

    E-Print Network [OSTI]

    Soler, R; Ballester, J L

    2015-01-01T23:59:59.000Z

    The ratio of the period of the fundamental mode to that of the first overtone of kink oscillations, from here on the "period ratio", is a seismology tool that can be used to infer information about the spatial variation of density along solar magnetic flux tubes. The period ratio is 2 in longitudinally homogeneous thin tubes, but it differs from 2 due to longitudinal inhomogeneity. In this paper we investigate the period ratio in longitudinally inhomogeneous prominence threads and explore its implications for prominence seismology. We numerically solve the two-dimensional eigenvalue problem of kink oscillations in a model of a prominence thread. We take into account three nonuniform density profiles along the thread. In agreement with previous works that used simple piecewise constant density profiles, we find that the period ratio is larger than 2 in prominence threads. When the ratio of the central density to that at the footpoints is fixed, the period ratio depends strongly on the form of the density profi...

  13. Curious Variables Experiment (CURVE). Three Periodicities of BF Ara

    E-Print Network [OSTI]

    A. Olech; A. Rutkowski; A. Schwarzenberg-Czerny

    2008-01-10T23:59:59.000Z

    We report CCD photometry of the dwarf nova BF Ara throughout fifteen consecutive nights in quiescence. Light curve in this interval is dominated by a large amplitude around 0.8 mag modulation consisting two periods. Higher amplitude signal is characterized by period of 0.082159(4) days, which was increasing at the rate of dotP/Psh = 3.8(3)* 10^{-5}. Weaker and stable signal has period of 0.084176(21) days. Knowing the superhump period of BF Ara determined by Kato et al. (2003) and equal to 0.08797(1) days, the first modulation is interpreted as quiescent negative superhump arising from retrograde precesion of titled accretion disk and the latter one as an orbital period of the binary. The respective period excess and defect are epsilon_+ = 4.51% +/- 0.03% and epsilon_- = -2.44% +/- 0.02%. Thus BF Ara is yet another in-the-gap nova with mass ratio q of around 0.21.

  14. Intermittent and sustained periodic windows in networked chaotic Rssler oscillators

    SciTech Connect (OSTI)

    He, Zhiwei; Sun, Yong [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China) [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhan, Meng, E-mail: zhanmeng@wipm.ac.cn [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)] [Wuhan Center for Magnetic Resonance, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

    2013-12-15T23:59:59.000Z

    Route to chaos (or periodicity) in dynamical systems is one of fundamental problems. Here, dynamical behaviors of coupled chaotic Rssler oscillators on complex networks are investigated and two different types of periodic windows with the variation of coupling strength are found. Under a moderate coupling, the periodic window is intermittent, and the attractors within the window extremely sensitively depend on the initial conditions, coupling parameter, and topology of the network. Therefore, after adding or removing one edge of network, the periodic attractor can be destroyed and substituted by a chaotic one, or vice versa. In contrast, under an extremely weak coupling, another type of periodic window appears, which insensitively depends on the initial conditions, coupling parameter, and network. It is sustained and unchanged for different types of network structure. It is also found that the phase differences of the oscillators are almost discrete and randomly distributed except that directly linked oscillators more likely have different phases. These dynamical behaviors have also been generally observed in other networked chaotic oscillators.

  15. Time-periodic solutions of the Benjamin-Ono equation

    SciTech Connect (OSTI)

    Ambrose , D.M.; Wilkening, Jon

    2008-04-01T23:59:59.000Z

    We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.

  16. Periodic Discrete Energy for Long-Range Potentials

    E-Print Network [OSTI]

    D. P. Hardin; E. B. Saff; Brian Simanek

    2014-12-11T23:59:59.000Z

    We consider periodic energy problems in Euclidean space with a special emphasis on long-range potentials that cannot be defined through the usual infinite sum. One of our main results builds on more recent developments of Ewald summation to define the periodic energy corresponding to a large class of long-range potentials. Two particularly interesting examples are the logarithmic potential and the Riesz potential when the Riesz parameter is smaller than the dimension of the space. For these examples, we use analytic continuation methods to provide concise formulas for the periodic kernel in terms of the Epstein Hurwitz Zeta function. We apply our energy definition to deduce several properties of the minimal energy including the asymptotic order of growth and the distribution of points in energy minimizing configurations as the number of points becomes large. We conclude with some detailed calculations in the case of one dimension, which shows the utility of this approach.

  17. Counting of Sieber-Richter pairs of periodic orbits

    E-Print Network [OSTI]

    Gutkin, Boris

    2011-01-01T23:59:59.000Z

    In the framework of the semiclassical approach the universal spectral correlations in the Hamiltonian systems with classical chaotic dynamics can be attributed to the systematic correlations between actions of periodic orbits which (up to the switch in the momentum direction) pass through approximately the same points of the phase space. By considering symbolic dynamics of the system one can introduce a natural ultrametric distance between periodic orbits and organize them into clusters. Each cluster consists of orbits approaching closely each other in the phase space. We study the distribution of cluster sizes for the backer's map in the asymptotic limit of long trajectories. This problem is equivalent to the one of counting degeneracies in the length spectrum of the {\\it de Bruijn} graphs. Based on this fact, we derive the probability $\\P_k$ that $k$ randomly chosen periodic orbits belong to the same cluster. Furthermore, we find asymptotic behaviour of the largest cluster size $|\\Cll_{\\max}|$ and derive th...

  18. Phase transitions in full counting statistics for periodic pumping

    E-Print Network [OSTI]

    Dmitri A. Ivanov; Alexander G. Abanov

    2010-07-16T23:59:59.000Z

    We discuss the problem of full counting statistics for periodic pumping. The probability generating function is usually defined on a circle of the "physical" values of the counting parameter, with its periodicity corresponding to charge quantization. The extensive part of the generating function can either be an analytic function on this circle or have singularities. These two cases may be interpreted as different thermodynamic phases in time domain. We discuss several examples of phase transitions between these phases for classical and quantum systems. Finally, we prove a criterion for the "analytic" phase in the problem of a quantum pump for noninteracting fermions.

  19. Truncation of Periodic Image Interactions for Confined Systems

    E-Print Network [OSTI]

    Sohrab Ismail-Beigi

    2006-03-16T23:59:59.000Z

    First principles methods based on periodic boundary conditions are used extensively by materials theorists. However, applying these methods to systems with confined electronic states entails the use of large unit cells in order to avoid artificial image interactions. We present a general approach for truncating the Coulomb interaction that removes image effects directly and leads to well converged results for modest-sized periodic cells. As an illustration, we find the lowest-energy quasiparticle and exciton states in two-dimensional hexagonal GaN sheets. These sheets have been proposed as parent materials for single-walled GaN nanotubes which may be of interest for optoelectronics.

  20. Period doubling, information entropy, and estimates for Feigenbaum's constants

    E-Print Network [OSTI]

    Reginald D. Smith

    2013-08-03T23:59:59.000Z

    The relationship between period doubling bifurcations and Feigenbaum's constants has been studied for nearly 40 years and this relationship has helped uncover many fundamental aspects of universal scaling across multiple nonlinear dynamical systems. This paper will combine information entropy with symbolic dynamics to demonstrate how period doubling can be defined using these tools alone. In addition, the technique allows us to uncover some unexpected, simple estimates for Feigenbaum's constants which relate them to log 2 and the golden ratio, phi, as well as to each other.

  1. Gravitational Waves from Periodic Three-Body Systems

    E-Print Network [OSTI]

    Dmitrainovi?, V; Hudomal, Ana

    2015-01-01T23:59:59.000Z

    Three bodies moving in a periodic orbit under the influence of Newtonian gravity ought to emit gravitational waves. We have calculated the gravitational radiation quadrupolar waveforms and the corresponding luminosities for the 13+11 recently discovered three-body periodic orbits in Newtonian gravity. These waves clearly allow one to distinguish between their sources: all 13+11 orbits have different waveforms and their luminosities (evaluated at the same orbit energy and body mass) vary by up to 13 orders of magnitude in the mean, and up to 20 orders of magnitude for the peak values.

  2. Controlling mobility via rapidly oscillating time-periodic stimulus

    E-Print Network [OSTI]

    Prasun Sarkar; Alok Kumar Maity; Anindita Shit; Sudip Chattopadhyay; Jyotipratim Ray Chaudhuri; Suman K Banik

    2014-03-26T23:59:59.000Z

    To address the dynamics of a Brownian particle on a periodic symmetric substrate under high-frequency periodic forcing with a vanishing time average, we construct an effective Langevin dynamics by invoking Kapitza-Landau time window. Our result is then exploited to simulate the mobility both for original and effective dynamics which are in good agreement with theoretical predictions. This close agreement and the enhancement of mobility are very robust against the tailoring of amplitude-to-frequency ratio which substantiates the correctness of our calculation. Present results may be illuminating for understanding the dynamics of cold atoms in electromagnetic fields.

  3. Periodic orbit theory of chaotic tunneling Olivier Sigwarth

    E-Print Network [OSTI]

    Cvitanovc', Predrag

    pre­ cisely in this organization into nearly cancelling combinations: cycle expansions are dominated Cvitanovi'c April 17, 1998 PACS: 03.20.+i, 03.65.Sq, 05.40.+j, 05.45.+b keywords: cycle expansions, periodic orbits, dynamical zeta functions, quantum tunneling. Abstract 1 cycle expansions. 1 Introduction

  4. Periodic orbit theory of linear response Niels Sndergaard

    E-Print Network [OSTI]

    Cvitanovc', Predrag

    all distinct non- repeating combinations of prime cycles. For k > 1, tp1+p2+...+pk are weights pre- cisely in this organization into nearly cancelling combinations: cycle expansions are dominated: 03.20.+i, 03.65.Sq, 05.40.+j, 05.45.+b keywords: cycle expansions, periodic orbits, dynamical zeta

  5. Quality of monitoring of stochastic events by periodic and ...

    E-Print Network [OSTI]

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

    2010-08-28T23:59:59.000Z

    infeasible to transmit sensor data over long distances, or in an underground system of ... the case of static sensors, their placement to best protect people has been ... function of the event dynamics and type of events: (1) What is the QoM of a ... a class of periodic coverage algorithms considering the travel time overhead.

  6. lthough Earth has undergone many periods of significant environmen-

    E-Print Network [OSTI]

    Horton, Tom

    A lthough Earth has undergone many periods of significant environmen- tal change, the planet push the Earth system outside the stable environmental state of the Holocene, with consequences occurred naturally and Earth's regu- latory capacity maintained the conditions that enabled human

  7. L-FUNCTIONS AND PERIODS OF ADJOINT MOTIVES Michael Harris

    E-Print Network [OSTI]

    Harris, Michael - Institut de Mathématiques de Jussieu, Université Paris 7

    L-FUNCTIONS AND PERIODS OF ADJOINT MOTIVES Michael Harris UFR de Math´ematiques Universit´e Paris 7 for unitary groups, due to Neal Harris, with Deligne's conjecture on critical values of L-functions. When for inclusions of special orthogonal groups; the version for unitary groups, due to Neal Harris [NH], gives

  8. Total Estimated Contract Cost: Performance Period Total Fee Paid

    Office of Environmental Management (EM)

    Fee Paid 127,390,991 Contract Number: Fee Available Contract Period: Contract Type: Cost Plus Award Fee 4,104,318,749 28,500,000 31,597,837 0 39,171,018 32,871,600 EM...

  9. Contract Periods for 2012-2013 Residence Halls

    E-Print Network [OSTI]

    Minnesota, University of

    Contract Periods for 2012-2013 Residence Halls All of the residence halls are on Fall/Spring Contracts. THERE IS NO FALL ONLY CONTRACT. · The residence halls open for the fall semester on September 1 rate for the number of days they stay. Apartments Your contract entitles you to an apartment space

  10. On the Survival of Short-Period Terrestrial Planets

    E-Print Network [OSTI]

    Rosemary A. Mardling; D. N. C. Lin

    2004-06-30T23:59:59.000Z

    The currently feasible method of detection of Earth-mass planets is transit photometry, with detection probability decreasing with a planet's distance from the star. The existence or otherwise of short-period terrestrial planets will tell us much about the planet formation process, and such planets are likely to be detected first if they exist. Tidal forces are intense for short-period planets, and result in decay of the orbit on a timescale which depends on properties of the star as long as the orbit is circular. However, if an eccentric companion planet exists, orbital eccentricity ($e_i$) is induced and the decay timescale depends on properties of the short-period planet, reducing by a factor of order $10^5 e_i^2$ if it is terrestrial. Here we examine the influence companion planets have on the tidal and dynamical evolution of short-period planets with terrestrial structure, and show that the relativistic potential of the star is fundamental to their survival.

  11. Colloidal Inks for Directed Assembly of 3-D Periodic Structures

    E-Print Network [OSTI]

    Lewis, Jennifer

    during assembly, which simultaneously facilitated bonding and shape retention of the deposited elements the desired 3-D periodicity, places the most stringent demands on ink design. Direct-write techniques- controlled viscoelastic response; that is, they must be able to flow through a deposition nozzle

  12. Particle energization through time-periodic helical magnetic fields

    E-Print Network [OSTI]

    Mitra, Dhrubaditya

    We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients A=B=C=1 are chaotic, and we show ...

  13. Excitation and control of multi-phase periodic waves in

    E-Print Network [OSTI]

    Fominov, Yakov

    the phase of the excited wave by the driver ("phase-locking") control the wave by varying parametersExcitation and control of multi-phase periodic waves in sine-Gordon equation Arkadiy Shagalovcr U ()eff U ()eff Threshold condition for phase-locking: > cr = 0.41 > cr = 3.28 3/2 0m 3

  14. Overall Dynamic Properties of 3-D periodic elastic composites

    E-Print Network [OSTI]

    Ankit Srivastava; Sia Nemat-Nasser

    2011-05-27T23:59:59.000Z

    A method for the homogenization of 3-D periodic elastic composites is presented. It allows for the evaluation of the averaged overall frequency dependent dynamic material constitutive tensors relating the averaged dynamic ?eld variable tensors of velocity, strain, stress, and linear momentum. The formulation is based on micromechanical modeling of a representative unit cell of a composite proposed by Nemat-Nasser & Hori (1993), Nemat-Nasser et. al. (1982) and Mura (1987) and is the 3-D generalization of the 1-D elastodynamic homogenization scheme presented by Nemat-Nasser & Srivastava (2011). We show that for 3-D periodic composites the overall compliance (stiffness) tensor is hermitian, irrespective of whether the corresponding unit cell is geometrically or materially symmetric.Overall mass density is shown to be a tensor and, like the overall compliance tensor, always hermitian. The average strain and linear momentum tensors are, however, coupled and the coupling tensors are shown to be each others' hermitian transpose. Finally we present a numerical example of a 3-D periodic composite composed of elastic cubes periodically distributed in an elastic matrix. The presented results corroborate the predictions of the theoretical treatment.

  15. Periodic NDE for Bridge Maintenance Ralf W. Arndt

    E-Print Network [OSTI]

    Huston, Dryver R.

    Periodic NDE for Bridge Maintenance Ralf W. Arndt NRC Research Associate U.S. Federal Highway Administration NDE Center 6300 Georgetown Pike McLean, VA 22101, USA ralf.arndt@fhwa.dot.gov Frank Jalinoos Program Manager U.S. Federal Highway Administration NDE Center 6300 Georgetown Pike McLean, VA 22101, USA

  16. Proton aurora related to intervals of pulsations of diminishing periods

    E-Print Network [OSTI]

    California at Berkeley, University of

    Proton aurora related to intervals of pulsations of diminishing periods A. G. Yahnin,1 T. A precipitation produced by the cyclotron instability can be responsible for proton aurora. Indeed, the relationship between some types of proton aurora (proton spots and proton flashes) and pulsations in the Pc1

  17. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Raj Saha

    2015-02-21T23:59:59.000Z

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural periodicity and produces burst patterns very similar to what is observed in temperature proxy data. Numerical experiments with the model also suggests that the characteristic period of 1,500 years is due to the geometry, or the effective heat capacity, of the ocean that comes under sea ice cover.

  18. Effect of Materials and Curing Period on Shrinkage of Concrete

    E-Print Network [OSTI]

    West, Maria B.

    2010-02-04T23:59:59.000Z

    to 365 days at 23 2o C (73 3o F) and 50 4 percent relative humidity. Parameters include aggregate content; cement fineness; water-cement ratio; curing period; partial cement replacement by slag, Class C fly ash, or silica fume; superplasticizer...

  19. Periodic Constraint-Based Control Using Dynamic Wireless Sensor Scheduling

    E-Print Network [OSTI]

    Johansson, Karl Henrik

    Periodic Constraint-Based Control Using Dynamic Wireless Sensor Scheduling James Weimer, Jos´e Ara´ujo, Aitor Hernandez and Karl Henrik Johansson Abstract-- Constraint-based control over wireless sensor net- works (WSNs) require control strategies that achieve a desired closed-loop system performance while

  20. Diffusive propagation of wave packets in a fluctuating periodic potential

    E-Print Network [OSTI]

    Eman Hamza; Yang Kang; Jeffrey Schenker

    2010-10-05T23:59:59.000Z

    We consider the evolution of a tight binding wave packet propagating in a fluctuating periodic potential. If the fluctuations stem from a stationary Markov process satisfying certain technical criteria, we show that the square amplitude of the wave packet after diffusive rescaling converges to a superposition of solutions of a heat equation.

  1. Devil's Staircase in Magnetoresistance of a Periodic Array of Scatterers

    E-Print Network [OSTI]

    Jan Wiersig; Kang-Hun Ahn

    2001-02-28T23:59:59.000Z

    The nonlinear response to an external electric field is studied for classical non-interacting charged particles under the influence of a uniform magnetic field, a periodic potential, and an effective friction force. We find numerical and analytical evidence that the ratio of transversal to longitudinal resistance forms a Devil's staircase. The staircase is attributed to the dynamical phenomenon of mode-locking.

  2. Periodic Schrdinger operators with local defects and spectral pollution

    E-Print Network [OSTI]

    Eric Cancs; Virginie Ehrlacher; Yvon Maday

    2011-11-16T23:59:59.000Z

    This article deals with the numerical calculation of eigenvalues of perturbed periodic Schr\\"odinger operators located in spectral gaps. Such operators are encountered in the modeling of the electronic structure of crystals with local defects, and of photonic crystals. The usual finite element Galerkin approximation is known to give rise to spectral pollution. In this article, we give a precise description of the corresponding spurious states. We then prove that the supercell model does not produce spectral pollution. Lastly, we extend results by Lewin and S\\'er\\'e on some no-pollution criteria. In particular, we prove that using approximate spectral projectors enables one to eliminate spectral pollution in a given spectral gap of the reference periodic Sch\\"odinger operator.

  3. Periodic photometric variability of the brown dwarf Kelu-1

    E-Print Network [OSTI]

    F. J. Clarke; C. G. Tinney; K. R. Covey

    2002-01-10T23:59:59.000Z

    We have detected a strong periodicity of 1.80+/-0.05 hours in photometric observations of the brown dwarf Kelu-1. The peak-to-peak amplitude of the variation is ~1.1% (11.9+/-0.8 mmag) in a 41nm wide filter centred on 857nm and including the dust/temperature sensitive TiO & CrH bands. We have identified two plausible causes of variability: surface features rotating into- and out-of-view and so modulating the light curve at the rotation period; or, elliposidal variability caused by an orbiting companion. In the first scenario, we combine the observed vsin(i) of Kelu-1 and standard model radius to determine that the axis of rotation is inclined at 65+/-12 degrees to the line of sight.

  4. Periodic fluctuations in deep water formation due to sea ice

    E-Print Network [OSTI]

    Saha, Raj

    2015-01-01T23:59:59.000Z

    During the last ice age several quasi-periodic abrupt warming events took place. Known as Dansgaard-Oeschger (DO) events their effects were felt globally, although the North Atlantic experienced the largest temperature anomalies. Paleoclimate data shows that the fluctuations often occurred right after massive glacial meltwater releases in the North Atlantic and in bursts of three or four with progressively decreasing strengths. In this study a simple dynamical model of an overturning circulation and sea ice is developed with the goal of understanding the fundamental mechanisms that could have caused the DO events. Interaction between sea ice and the overturning circulation in the model produces self-sustained oscillations. Analysis and numerical experiments reveal that the insulating effect of sea ice causes the ocean to periodically vent out accumulated heat in the deep ocean into the atmosphere. Subjecting the model to idealized freshwater forcing mimicking Heinrich events causes modulation of the natural p...

  5. A climatological analysis of the freeze period of Texas

    E-Print Network [OSTI]

    Donahue, Christopher Alan

    1991-01-01T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Synoptic Patterns Sample Calculations and Applications CONCLUSIONS AND RECOMMENDATIONS. . . 31 41 45 59 70 76 VI 81 APPENDIX Computer Programs 83 VITA 90 LIST OF TABLES Table Page 1 Periods of record for substations 17 2 Sample of data... of the freeze in parentheses. . . . . . . . . 64 16 Dates of 10% and 90% first and last freeze probabilities 75 tx LIST OF FIGURES Figure Page Map of the study area with the substation locations indicated . 2 Station history for Corsicana, Texas 16...

  6. Sorting by Periodic Potential Energy Landscapes: Optical Fractionation

    E-Print Network [OSTI]

    Kosta Ladavac; Karen Kasza; David G. Grier

    2003-10-16T23:59:59.000Z

    Viscously damped objects driven through a periodically modulated potential energy landscape can become kinetically locked in to commensurate directions through the landscape, and thus can be deflected away from the driving direction. We demonstrate that the threshold for an object to become kinetically locked in to an array can depend exponentially on its size. When implemented with an array of holographic optical tweezers, this provides the basis for a continuous and continuously optimized sorting technique for mesoscopic objects called ``optical fractionation''.

  7. Wave propagation in periodic networks of thin fibers

    E-Print Network [OSTI]

    S. Molchanov; B. Vainberg

    2009-08-02T23:59:59.000Z

    We will discuss a one-dimensional approximation for the problem of wave propagation in networks of thin fibers. The main objective here is to describe the boundary (gluing) conditions at branching points of the limiting one-dimensional graph. The results will be applied to Mach-Zehnder interferometers on chips and to periodic chains of the interferometers. The latter allows us to find parameters which guarantee the transparency and slowing down of wave packets.

  8. Modeling performance of horizontal, undulating, and multilateral wells

    E-Print Network [OSTI]

    Kamkom, Rungtip

    2009-05-15T23:59:59.000Z

    .2. 10 0 10 20 30 40 50 0 5 10 15 20 25 30 35 40 45 50 Productivity index from modified Furui's model P r o d u c t i v i t y i n d e x f r o m l i n e s o u r c e m o d e l . Fig. 2.2 Validation modified Furui?s model with line source... through the reservoir the error is less than 10% for isotropic reservoir. 0 20 40 60 80 100 0 1000 2000 3000 4000 5000 Well length, ft P r o d u c t i v i t y i n d e x , ( S T B / D ) / p s i...

  9. Lateral undulation of a snake-like robot

    E-Print Network [OSTI]

    Gupta, Amit

    2007-01-01T23:59:59.000Z

    Snake robots have been studied by many researchers but historically more on a theoretical basis. Recently, more and more robotic snakes have been realized in hardware. This thesis presents a design process for the electrical, ...

  10. SCIENTIFIC POTENTIAL AND DESIGN CONSIDERATIONS FOK AN UNDULATOR BEAM LINE

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0 ResourceAwards SAGE Awards ,# , on behalf of Presented

  11. Dependence of Undulator Spectra on Viewing Slits S. H. Kim

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phasesData Files DataADVANCESDepartmentDepartmental VitalHydropower60

  12. ANL/APS/TB-3 Undulator A Characteristics and Specifications

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations2 Print258Department of31 . Wiggler9

  13. Successful long-term management of refractory cutaneous and upper airway sarcoidosis with periodic infliximab infusion

    E-Print Network [OSTI]

    Rosen, Ted; Doherty, Christy

    2007-01-01T23:59:59.000Z

    with periodic infliximab infusion Ted Rosen MD, Christytreated with infliximab infusion therapy at a dose ofresponse to regular periodic infusions of the chimeric anti-

  14. The Joint Owners' Group Program on MOV Periodic Verification

    SciTech Connect (OSTI)

    Damerell, Paul S.; Spears, Todd A. [MPR Associates Inc., 140 Mustang Circle, Simpsonville, SC 29681 (United States)

    2002-07-01T23:59:59.000Z

    To address long-term motor operated valve (MOV) performance, the Babcock and Wilcox, Boiling Water Reactor, Combustion Engineering and Westinghouse Groups (B and WOG, BWROG, CEOG and WOG) teamed in 1997 to form the Joint Group (JOG) MOV Periodic Verification (PV) Program. This program is nearing completion, with 98 of the 103 operating U.S. reactor units participating. The goal of the program is to provide a justified approach for periodically testing MOVs, that addresses potential degradation. The program defines an interim approach that specifies periodic tests without flow and differential pressure (DP), at a frequency determined by the s risk significance and margin. To justify this approach, each participating plant is also DP testing 2 valves per unit. Each valve is tested three times over five years, with at least one year between tests. The data are evaluated jointly to confirm or adjust the initial guidance. The majority of the tests are complete and conclusions are coming into focus. For gate valves, when the valve factor is initially low, increases can occur between one test and a later test. One common way that the valve factor becomes low is disassembling and reassembling the valve. The data show that, following valve disassembly and re-assembly, the valve factor tends to be reduced, and it tends to increase in subsequent service. Outside of the valves disassembled and reassembled, some gate valves have low valve factors apparently because the valves are not stroked under DP conditions in service. For butterfly valves, there have been no observations of degradation in bearing friction coefficient. A few valves with bronze bearings in raw (untreated) water service have shown significant variations in friction, but they tend to be a mixture of increases and decreases with no pattern of degradation. Globe valves, both unbalanced and balanced, tend to show a constant valve factor with no indication of degradation. (authors)

  15. Holographic classification of Topological Insulators and its 8-fold periodicity

    E-Print Network [OSTI]

    Andr LeClair; Denis Bernard

    2012-05-16T23:59:59.000Z

    Using generic properties of Clifford algebras in any spatial dimension, we explicitly classify Dirac hamiltonians with zero modes protected by the discrete symmetries of time-reversal, particle-hole symmetry, and chirality. Assuming the boundary states of topological insulators are Dirac fermions, we thereby holographically reproduce the Periodic Table of topological insulators found by Kitaev and Ryu. et. al, without using topological invariants nor K-theory. In addition we find candidate Z_2 topological insulators in classes AI, AII in dimensions 0,4 mod 8 and in classes C, D in dimensions 2,6 mod 8.

  16. Dense periodic packings of tetrahedra with small repeating units

    E-Print Network [OSTI]

    Yoav Kallus; Veit Elser; Simon Gravel

    2010-03-19T23:59:59.000Z

    We present a one-parameter family of periodic packings of regular tetrahedra, with the packing fraction $100/117\\approx0.8547$, that are simple in the sense that they are transitive and their repeating units involve only four tetrahedra. The construction of the packings was inspired from results of a numerical search that yielded a similar packing. We present an analytic construction of the packings and a description of their properties. We also present a transitive packing with a repeating unit of two tetrahedra and a packing fraction $\\frac{139+40\\sqrt{10}}{369}\\approx0.7194$.

  17. Tsallis Distribution Decorated With Log-Periodic Oscillation

    E-Print Network [OSTI]

    Wilk, Grzegorz

    2015-01-01T23:59:59.000Z

    In many situations, in all branches of physics, one encounters power-like behavior of some variables which are best described by a Tsallis distribution characterized by a nonextensivity parameter $q$ and scale parameter $T$. However, there exist experimental results which can be described only by a Tsallis distributions which are additionally decorated by some log-periodic oscillating factor. We argue that such a factor can originate from allowing for a complex nonextensivity parameter $q$. The possible information conveyed by such an approach (like the occurrence of complex heat capacity, the notion of complex probability or complex multiplicative noise) will also be discussed.

  18. Tsallis Distribution Decorated With Log-Periodic Oscillation

    E-Print Network [OSTI]

    Grzegorz Wilk; Zbigniew Wlodarczyk

    2015-01-12T23:59:59.000Z

    In many situations, in all branches of physics, one encounters power-like behavior of some variables which are best described by a Tsallis distribution characterized by a nonextensivity parameter $q$ and scale parameter $T$. However, there exist experimental results which can be described only by a Tsallis distributions which are additionally decorated by some log-periodic oscillating factor. We argue that such a factor can originate from allowing for a complex nonextensivity parameter $q$. The possible information conveyed by such an approach (like the occurrence of complex heat capacity, the notion of complex probability or complex multiplicative noise) will also be discussed.

  19. Properties of an axially periodic magnetic field in a betatron

    SciTech Connect (OSTI)

    Zvontsov, A.A.; Filinova, V.A.; Chakhlov, V.L.

    1983-07-01T23:59:59.000Z

    It is shown by solving an equation for the vector potential A (r, z) of the magnetic field that under appropriate conditions the focusing properties of a betatron magnetic field are periodic with respect to the z coordinate. Under these conditions there may be several equilibrium orbits lying in parallel planes z = 0, z = z/sub 01/ xxx, z = mz/sub 01/ in the accelerator. An equation is derived for the distance z/sub 01/ between the equilibrium orbit planes for a given orbit radius r/sub 0/ and field decay exponent n/sub 0/. The operation of such accelerators is described.

  20. Light bullets in nonlinear periodically curved waveguide arrays

    SciTech Connect (OSTI)

    Matuszewski, Michal; Garanovich, Ivan L. [Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Sukhorukov, Andrey A. [Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Centre for Ultra-high Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia)

    2010-04-15T23:59:59.000Z

    We predict that stable mobile spatiotemporal solitons can exist in arrays of periodically curved optical waveguides. We find two-dimensional light bullets in planar arrays with harmonic waveguide bending and three-dimensional bullets in square lattices with helical waveguide bending using variational formalism. Stability of the light-bullet solutions is confirmed by the direct numerical simulations which show that the light bullets can freely move across the curved arrays. This mobility property is a distinguishing characteristic compared to previously considered discrete light bullets which were trapped to a specific lattice site. These results suggest new possibilities for flexible spatiotemporal manipulation of optical pulses in photonic lattices.

  1. EIS-0236: Extension of Comment Period | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat Pump Models |Conduct,Final9:DepartmentExtension of Comment Period EIS-0236:

  2. PARC Periodical | Vol. 6, Issue 1 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanningP-GlycoproteinAmmoniaPeriodical | Vol.

  3. PARC Periodical, Volume 5, Issue 2 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanningP-GlycoproteinAmmoniaPeriodical |

  4. PARC Periodical- Volume 4, Issue 4 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanningP-GlycoproteinAmmoniaPeriodical |4

  5. PARC Periodical- Volume 4, Issue 5 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanningP-GlycoproteinAmmoniaPeriodical |45

  6. PARC Periodical- Volume 5, Issue 1 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanningP-GlycoproteinAmmoniaPeriodical |455,

  7. PARC Periodical: Volume 5, Issue 3 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002OpticsPeriodical: Volume 5, Issue 3 January 28, 2014 PARC

  8. Entropy production of diffusion in spatially periodic deterministic systems

    E-Print Network [OSTI]

    J. R. Dorfman; P. Gaspard; T. Gilbert

    2002-03-21T23:59:59.000Z

    This paper presents an {\\it ab initio} derivation of the expression given by irreversible thermodynamics for the rate of entropy production for different classes of diffusive processes. The first class are Lorentz gases, where non-interacting particles move on a spatially periodic lattice, and collide elastically with fixed scatterers. The second class are periodic systems where $N$ particles interact with each other, and one of them is a tracer particle which diffuses among the cells of the lattice. We assume that, in either case, the dynamics of the system is deterministic and hyperbolic, with positive Lyapunov exponents. This work extends methods originally developed for a chaotic two-dimensional model of diffusion, the multi-baker map, to higher dimensional, continuous time dynamical systems appropriate for systems with one or more moving particles. Here we express the rate of entropy production in terms of hydrodynamic measures that are determined by the fractal properties of microscopic hydrodynamic modes that describe the slowest decay of the system to an equilibrium state.

  9. Periodic forcing of graphene as geometric ripples on its surface

    E-Print Network [OSTI]

    Tridev Mishra; Tapomoy Guha Sarkar; Jayendra N. Bandyopadhyay

    2014-10-27T23:59:59.000Z

    We explore the possibility of using modulated high frequency periodic driving of mono-layer graphene to create effects of curved geometry. The low energy continuum limit of graphene is modeled using Dirac equation in (2+1) dimensions. We suggest that the modifications to the Dirac equation when written in a curved background space can also be induced by a suitable driving scheme. The time dependent system yields, in the approximate limit of high frequency pulsing, an effective time independent Hamiltonian that governs the time evolution, except for an initial and a final kick. We use a specific form of 4-phase pulsed forcing with suitably tuned choice of modulating operators to mimic the effects of weak metric perturbations and thereby effectively induce mild wrinkles on the surface. The strength of the perturbation is found to be directly related to omega^{-1} the time period of the driving field at the leading order. We apply the method to engineer some specific `nearly flat' metrics and we find that the imprint of curvilinear geometry modifies the band structure significantly. The emergence of band gap at the Dirac point is crucial in this regard. We suggest that this method shall be useful in studying the response of various properties of such materials to non-trivial geometry without requiring any actual physical deformations.

  10. Feedback Control of the Sawtooth Period through Real Time Control of the Ion Cyclotron Resonance Frequency

    E-Print Network [OSTI]

    Feedback Control of the Sawtooth Period through Real Time Control of the Ion Cyclotron Resonance Frequency

  11. Quasi-periodic Fibonacci and periodic one-dimensional hypersonic phononic crystals of porous silicon: Experiment and simulation

    SciTech Connect (OSTI)

    Aliev, Gazi N., E-mail: g.aliev@bath.ac.uk; Goller, Bernhard [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom)

    2014-09-07T23:59:59.000Z

    A one-dimensional Fibonacci phononic crystal and a distributed Bragg reflector were constructed from porous silicon. The structures had the same number of layers and similar acoustic impedance mismatch, and were electrochemically etched in highly boron doped silicon wafers. The thickness of the individual layers in the stacks was approximately 2??m. Both types of hypersonic band gap structure were studied by direct measurement of the transmittance of longitudinal acoustic waves in the 0.12.6?GHz range. Acoustic band gaps deeper than 50?dB were detected in both structures. The experimental results were compared with model calculations employing the transfer matrix method. The acoustic properties of periodic and quasi-periodic structures in which half-wave retarding bi-layers do not consist of two quarter-wave retarding layers are discussed. The strong correlation between width and depth of gaps in the transmission spectra is demonstrated. The dominant mechanisms of acoustic losses in porous multilayer structures are discussed. The elastic constants remain proportional over our range of porosity, and hence, the Grneisen parameter is constant. This simplifies the expression for the porosity dependence of the Akhiezer damping.

  12. Ratchet transport and periodic structures in parameter space

    E-Print Network [OSTI]

    Alan Celestino; Cesar Manchein; Holokx A. Albuquerque; Marcus W. Beims

    2011-11-06T23:59:59.000Z

    Ratchet models are prominent candidates to describe the transport phenomenum in nature in the absence of external bias. This work analyzes the parameter space of a discrete ratchet model and gives direct connections between chaotic domains and a family of isoperiodic stable structures with the ratchet current. The isoperiodic structures appear along preferred direction in the parameter space giving a guide to follow the current, which usually increases inside the structures but is independent of the corresponding period. One of such structures has the shrimp-shaped form which is known to be an universal structure in the parameter space of dissipative systems. Currents in parameter space provide a direct measure of the momentum asymmetry of the multistable and chaotic attractors times the size of the corresponding basin of attraction. Transport structures are shown to exist in the parameter space of the Langevin equation with an external oscillating force.

  13. Coupling Impedance of a Periodic Array of Diaphragms (Erratum)

    SciTech Connect (OSTI)

    Stupakov, G.V.; /SLAC

    2012-05-24T23:59:59.000Z

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

  14. Periodic relativity: deflection of light, acceleration, rotation curves

    E-Print Network [OSTI]

    Vikram H. Zaveri

    2014-12-08T23:59:59.000Z

    Vectorial analysis relating to derivation of deflection of light is presented. Curvilinear acceleration is distinguished from the Newtonian polar conic acceleration. The difference between the two is due to the curvature term. Lorentz invariant expression for acceleration is derived. A physical theory of rotation curves of galaxies based on second solution to Einstein's field equation is presented. Theory is applied to Milky Way, M31, NGC3198 and Solar system. Modified Kepler's third law yields correct orbital periods of stars in a galaxy. Deviation factor in the line element of the theory happens to be the ratio of the Newtonian gravitational acceleration to the measured acceleration of the star in the galaxy. Therefore this deviation factor can replace the MOND function.

  15. Periodic forcing of a 555-IC based hysteretic oscillator

    E-Print Network [OSTI]

    Moises Santillan

    2014-08-12T23:59:59.000Z

    In this work we designed and developed a master-slave electronic oscillatory system (based on the 555-timer IC working in the astable mode), and investigated its dynamic behavior regarding synchronization. For that purpose we measured the circulation number corresponding to the phase-locking rhythm achieved in a large set of values of the normalized forcing period (NFP) and of the coupling strength between the master and the slave oscillators. In particular we were interested in the system behavior in the strong-coupling limit, because such problem has not been extensively studied from an experimental perspective. Our results indicate the existence of a degenerate codimension-2 bifurcation point at NFP=1:2, where all the phase-locking regions converge in the very strong coupling limit. These findings were corroborated by a mathematical model we developed to that end.

  16. Transverse commensurability effect for vortices on periodic pinning arrays

    SciTech Connect (OSTI)

    Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, Cynthia J [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    Using computer simulations, we demonstrate a type of commensurability that occurs for vortices moving longitudinally through periodic pinning arrays in the presence of an additional transverse driving force. As a function of vortex density, there is a series of broad maxima in the transverse critical depinning force that do not fall at the matching fields where the number of vortices equals an integer multiple of the number of pinning sites. The commensurability effects are associated with dynamical states in which evenly spaced structures consisting of one or more moving rows of vortices form between rows of pinning sites. Remarkably, the critical transverse depinning force can be more than an order of magnitude larger than the longitudinal depinning force.

  17. Dynamically tunable Fano resonance in periodically asymmetric graphene nanodisk pair

    E-Print Network [OSTI]

    Zhang, Zhengren; Fan, Yuancheng; Yin, Pengfei; Zhang, Liwei; Shi, Xi

    2015-01-01T23:59:59.000Z

    We present a dynamically frequency tunable Fano resonance planar device composed of periodically asymmetric graphene nanodisk pair for the mid-infrared region. There are two kinds of modes in this structure, that is, the symmetric mode and the antisymmetric mode. The resonance coupling between the symmetric and antisymmetric modes creates a classical Fano resonance. Both of the Fano resonance amplitude and frequency of the structure can be dynamically controlled by varying the Fermi energy of graphene. Resonance transition in the structure is studied to reveal the physical mechanism behind the dynamically tunable Fano resonance. The features of the Fano resonant graphene nanostructures should have promising applications in tunable THz filters, switches, and modulators.

  18. The moments of Minkowski ?(x) function: dyadic period functions

    E-Print Network [OSTI]

    Alkauskas, Giedrius

    2008-01-01T23:59:59.000Z

    We examine the generating function of moments of the Minkowski question mark function ?(x), which describes the distribution or rationals according to their continued fraction expansion. It appears that the generating function possesses certain modular properties and is defined in the cut plane. The exponential generating function satisfies the integral equation, with kernel being the Bessel function of the first kind. Finally, the solution of this integral equation leads to the definition of dyadic period functions of weight 2 and index lambda. Such a form is defined and is holomorphic in the cut plane, it satisfies the semi-modular functional equation, and it exists for every lambda which is the eigen-value of the properly defined Hilbert-Schmidt integral operator.

  19. Physics Division progress report for period ending September 30, 1984

    SciTech Connect (OSTI)

    Livingston, A.B. (ed.)

    1985-01-01T23:59:59.000Z

    The research activities of the Division are centered primarily in three areas: experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. The largest of these efforts, experimental nuclear physics, is dominated by the heavy ion research program. A major responsibility under this program is the operation of the Holifield Heavy Ion Research Facility as a national user facility. During the period of this report, the facility has begun routine operation for the experimental program. The experimental atomic physics program has two components: the accelerator-based studies of basic collisional phenomena and the studies in support of the controlled fusion program. Also associated with the fusion-related studies are a plasma diagnostics program and the operation of an atomic physics data center. The theoretical physics program, both nuclear and atomic, is covered. This program has benefited this year from the success of the VAX-AP computer system and from the increase in manpower provided by the ORNL/University of Tennessee Distinguished Scientist Program. Smaller programs in applications and high-energy physics are summarized. During the period of this report, we continued to explore possible future extensions of the Holifield Facility. We retain a strong interest in a relativistic heavy-ion collider in the 10 x 10 GeV/nuclear energy range. The ideas for such a facility, described in last year's report, have been modified to utilize the HHIRF 25 MV tandem accelerator as the first stage. Finally, the report concludes with some general information on publications, Division activities, and personnel changes.

  20. IUPAC Periodic Table of Isotopes for the Educational Community

    SciTech Connect (OSTI)

    Holden N. E.; Holden,N.E.; Coplen,T.B.

    2012-07-15T23:59:59.000Z

    John Dalton first proposed the concept of atomic weights of the elements in the first decade of the nineteenth century. These atomic weights of the chemical elements were thought of as constants of nature, similar to the speed of light. Dmitri Mendeleev arranged the atomic weights of the elements in ascending order of value and used the systematic variation of their chemical properties to produce his Periodic Table of the Elements in 1869. Measurement of atomic weight values became an important chemical activity for a century and a half. Theodore Richards received a Noble Prize for his work in this area. In 1913, Fredrick Soddy found a species of radium, which had an atomic weight value of 228, compared to the familiar radium gas value of 226. Soddy coined the term 'isotope' (Greek for 'in the same place') to account for this second atomic weight value in the radium position of the Periodic Table. Both of these isotopes of radium are radioactive. Radioactive isotopes are energetically unstable and will decay (disintegrate) over time. The time it takes for one half of a sample of a given radioactive isotope to decay is the half-life of that isotope. In addition to having different atomic weight values, radium-226 and radium-228 also have different half-life values. Around the same time as Soddy's work, J.J. Thomson (discoverer of the electron) identified two stable (non-radioactive) isotopes of the same element, neon. Over the next 40 years, the majority of the known chemical elements were found to have two or more stable (or long-lived radioactive isotopes that contribute significantly to the determination of the atomic weights of the elements).

  1. Periodically-driven quantum matter: the case of resonant modulations

    E-Print Network [OSTI]

    N. Goldman; J. Dalibard; M. Aidelsburger; N. R. Cooper

    2014-10-30T23:59:59.000Z

    Quantum systems can show qualitatively new forms of behavior when they are driven by fast time-periodic modulations. In the limit of large driving frequency, the long-time dynamics of such systems can often be described by a time-independent effective Hamiltonian, which is generally identified through a perturbative treatment. Here, we present a general formalism that describes time-modulated physical systems, in which the driving frequency is large, but resonant with respect to energy spacings inherent to the system at rest. Such a situation is currently exploited in optical-lattice setups, where superlattice (or Wannier-Stark-ladder) potentials are resonantly modulated so as to control the tunneling matrix elements between lattice sites, offering a powerful method to generate artificial fluxes for cold-atom systems. The formalism developed in this work identifies the basic ingredients needed to generate interesting flux patterns and band structures using resonant modulations. We also discuss the micro-motion underlying the dynamics, and illustrate its characteristics based on diverse dynamic-lattice configurations. It is shown that the impact of the micro-motion on physical observables strongly depends on the implemented scheme, suggesting that a theoretical description in terms of the effective Hamiltonian alone is generally not sufficient to capture the full time-evolution of the system.

  2. A renewal theory approach to periodic copolymers with adsorption

    E-Print Network [OSTI]

    Francesco Caravenna; Giambattista Giacomin; Lorenzo Zambotti

    2007-10-24T23:59:59.000Z

    We consider a general model of a heterogeneous polymer chain fluctuating in the proximity of an interface between two selective solvents. The heterogeneous character of the model comes from the fact that the monomer units interact with the solvents and with the interface according to some charges that they carry. The charges repeat themselves along the chain in a periodic fashion. The main question concerning this model is whether the polymer remains tightly close to the interface, a phenomenon called localization, or whether there is a marked preference for one of the two solvents, thus yielding a delocalization phenomenon. In this paper, we present an approach that yields sharp estimates for the partition function of the model in all regimes (localized, delocalized and critical). This, in turn, makes possible a precise pathwise description of the polymer measure, obtaining the full scaling limits of the model. A key point is the closeness of the polymer measure to suitable Markov renewal processes, Markov renewal theory being one of the central mathematical tools of our analysis.

  3. The periodic standing-wave approximation: post-Minkowski computation

    E-Print Network [OSTI]

    Christopher Beetle; Benjamin Bromley; Napolen Hernndez; Richard H. Price

    2007-08-08T23:59:59.000Z

    The periodic standing wave method studies circular orbits of compact objects coupled to helically symmetric standing wave gravitational fields. From this solution an approximation is extracted for the strong field, slowly inspiralling motion of black holes and binary stars. Previous work on this model has dealt with nonlinear scalar models, and with linearized general relativity. Here we present the results of the method for the post-Minkowski (PM) approximation to general relativity, the first step beyond linearized gravity. We compute the PM approximation in two ways: first, via the standard approach of computing linearized gravitational fields and constructing from them quadratic driving sources for second-order fields, and second, by solving the second-order equations as an ``exact'' nonlinear system. The results of these computations have two distinct applications: (i) The computational infrastructure for the ``exact'' PM solution will be directly applicable to full general relativity. (ii) The results will allow us to begin supplying initial data to collaborators running general relativistic evolution codes.

  4. Physics division. Progress report for period ending September 30, 1996

    SciTech Connect (OSTI)

    Ball, S.J. [ed.

    1997-04-01T23:59:59.000Z

    This report covers the research and development activities of the Physics Division for the 1995 and 1996 fiscal years, beginning October 1, 1994, and ending September 30, 1996. The activities of the Division continue to be concentrated in the areas of experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. In addition, there are smaller programs in plasma diagnostics and data compilation and evaluation. During the period of this report, there has been considerable success in bringing the Holifield Radioactive Ion Beam Facility (HRIBF) into routine operation. The budgets of the nuclear physics portion of the Division have increased each year in nearly all areas, and several new members have been added to the Division research and development staff. On August 30, 1996, the HRIBF successfully accelerated its first radioactive ion beams, {sup 69}As and {sup 70}As. Prior to this, the heart of the facility, the RIB injector system, was completed, including installation of a remote handling system for the target/ion source assembly. Target and ion source development is likely to be the technical key to success of the HRIBF. We have expanded our efforts in those development areas. Of special note is the development of highly permeable composite targets which have now been shown to allow release of difficult-to-produce radioactive ions such as {sup 17,18}F. A summary of the HRIBF work is provided in Chapter 1, along with supporting activities of the Joint Institute for Heavy Ion Research.

  5. RF properties of periodic accelerating structures for linear colliders

    SciTech Connect (OSTI)

    Wang, J.W.

    1989-07-01T23:59:59.000Z

    With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e/sup /plus//e/sup /minus// physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs.

  6. A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical Parameters

    E-Print Network [OSTI]

    Victoria, University of

    A New Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Methodology for Frequency Domain Analysis of Wave Energy Converters with Periodically Varying Physical of Mechanical Engineering) ABSTRACT Within a wave energy converter's operational bandwidth, device operation

  7. A STUDY OF THE SHORTEST-PERIOD PLANETS FOUND WITH KEPLER

    E-Print Network [OSTI]

    Kotson, Michael C.

    We present the results of a survey aimed at discovering and studying transiting planets with orbital periods shorter than one day (ultra-short-period, or USP, planets), using data from the Kepler spacecraft. We computed ...

  8. PERIODIC SOLUTIONS WITH NONCONSTANT SIGN IN ABEL EQUATIONS OF THE SECOND KIND

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    PERIODIC SOLUTIONS WITH NONCONSTANT SIGN IN ABEL EQUATIONS OF THE SECOND KIND JOSEP M. OLM, XAVIER, is equivalent. Key words and phrases. Abel differential equations, periodic solutions. 1 #12;2 JOSEP M. OLM

  9. E-Print Network 3.0 - au parlement periode Sample Search Results

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

    periode Search Powered by Explorit Topic List Advanced Search Sample search results for: au parlement periode Page: << < 1 2 3 4 5 > >> 1 Proposition de sujet de thse Les fonctions...

  10. E-Print Network 3.0 - atlantic period ca Sample Search Results

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

    period ca Search Powered by Explorit Topic List Advanced Search Sample search results for: atlantic period ca Page: << < 1 2 3 4 5 > >> 1 A strong Atlantic subtropical jet cools...

  11. The Near-infrared Period-luminosity Relations of Cepheids in the Large Magellanic Cloud

    E-Print Network [OSTI]

    Mahzooni, Salma

    2011-08-08T23:59:59.000Z

    We present near-infrared (J & Ks) observations of Cepheids in the Large Magellanic Cloud. The goals of these observations are to better characterize the Cepheid Period-Luminosity relation at these wavelengths, especially for periods below 10 days...

  12. Wave propagation and instabilities in monolithic and periodically structured elastomeric materials undergoing large deformations

    E-Print Network [OSTI]

    Wave propagation and instabilities in monolithic and periodically structured elastomeric materials; revised manuscript received 3 October 2008; published 14 November 2008 Wave propagation in elastomeric states can influence wave propagation and hence interpretation of data. In the case of periodically

  13. Direct Energy Conversion Fission Reactor for the period December 1, 1999 through February 29, 2000

    SciTech Connect (OSTI)

    Brown, L.C.

    2000-03-20T23:59:59.000Z

    OAK B135 Direct Energy Conversion Fission Reactor for the period December 1, 1999 through February 29, 2000

  14. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2001-09-30T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001

  15. Fabrication of 200 nm period nanomagnet arrays using interference lithography and a negative resist

    E-Print Network [OSTI]

    Murphy, Thomas E.

    period array of holes in a positive resist and electrodeposited magnetic nickel and cobalt pillars.4 We

  16. The solution of Cauchy's problem for the Toda lattice with limit periodic initial data

    SciTech Connect (OSTI)

    Khanmamedov, A Kh [Baku State University, Baku (Azerbaijan)

    2008-04-30T23:59:59.000Z

    Cauchy's problem for Toda lattices with initial data equal to the sum of a periodic and a rapidly decreasing sequence is solved with the use of the inverse scattering method. A method allowing one to find a limit periodic solution of the Toda lattice from a known periodic solution is described. The existence and uniqueness of a limit periodic solution is proved. Bibliography: 17 titles.

  17. Globally synchronous ice core volcanic tracers and abrupt cooling during the last glacial period

    E-Print Network [OSTI]

    Price, P. Buford

    Globally synchronous ice core volcanic tracers and abrupt cooling during the last glacial period R (2006), Globally synchronous ice core volcanic tracers and abrupt cooling during the last glacial period histories from ice coring of Greenland and Antarctica over the period 2 to 45 ka, using SO4 anomalies

  18. Year Budget Period 1 5/1/2012 4/30/2013

    E-Print Network [OSTI]

    Kay, Mark A.

    /1/2014 ­ 4/30/2015 Year Budget Period 4 5/1/2015 date of the budget period funded by the FY15 funds ? The Final Financial of the end date of the last budget period funded by the FY14 funds ? Departments

  19. Entrainment to Periodic Initiation and Transition Rates in a Computational Model for Gene Translation

    E-Print Network [OSTI]

    Margaliot, Michael

    , the biological system must entrain or phase-lock to the periodic excitation. Entrainment is also important entrain or phase-lock to the periodic excitation. In other words, in response to a periodic excitation in biological systems (sometimes called phase locking [2]) and, more generally, biological oscillators

  20. Entrainment and termination of reentrant wave propagation in a periodically stimulated ring of excitable media

    E-Print Network [OSTI]

    Glass, Leon

    Entrainment and termination of reentrant wave propagation in a periodically stimulated ring periodic stimulation of a class of cardiac arrhythmias caused by reentrant wave propagation in the human wave of circulation. In analogy with earlier results found from the periodic stimulation

  1. Detection and discrimination of the periodicity of prime numbers by discrete Fourier transform

    E-Print Network [OSTI]

    Levente Csoka

    2015-01-27T23:59:59.000Z

    A novel representation of a quasi-periodic modified von Mangoldt function L(n) on prime numbers and its decomposition into Fourier series has been investigated. We focus on some particular quantities characterizing the modified von Mangoldt function. The results indicate that prime number progression can be decomposed into periodic sequences. The main approach is to decompose it into sin or cosine function. Basically, it is applied to extract hidden periodicities in seemingly quasi periodic prime function. Numerical evidences were provided to confirm the periodic distribution of primes.

  2. Vriend en vijand. Een vergelijkend onderzoek naar de Nederlandse beleidsvoering met betrekking tot Suriname in de periode 1975-1982 en de periode 1988-1993.

    E-Print Network [OSTI]

    Meij, K. van der

    2012-01-01T23:59:59.000Z

    ??In de periode 1975-1982 stelden Nederlanders vele voorwaarden aan de Surinamers in ruil voor ontwikkelingshulp. Desalniettemin had dit niet tot het gewenste resultaat geleid.Na de (more)

  3. The Properties of Long Period Variables in the LMC from MACHO

    SciTech Connect (OSTI)

    Fraser, O J; Hawley, S L; Cook, K H

    2008-05-06T23:59:59.000Z

    We present a new analysis of the long period variables in the Large Magellanic Cloud from the MACHO Variable Star Catalog. Three-quarters of our sample of evolved, variable stars have periodic light curves. We characterize the stars in our sample using the multiple periods found in their frequency spectra. Additionally, we use single-epoch 2MASS measurements to construct the average infrared light curves for different groups of these stars. Comparison with evolutionary models shows that stars on the RGB or the Early AGB often show non-periodic variability, but begin to pulsate with periods on the two shortest period-luminosity sequences (1 & 2) when they brighten to K{sub s} {approx} 13. The stars on the Thermally Pulsing AGB are more likely to pulsate with longer periods that lie on the next two P-L sequences (3 & 4), including the sequence associated with the Miras in the LMC. The Petersen diagram and its variants show that multi-periodic stars on each pair of these sequences (3 & 4, and 1 & 2), typically pulsate with periods associated only with that pair. The periods in these multi-periodic stars become longer and stronger as the star evolves. We further constrain the mechanism behind the long secondary periods (LSPs) seen in half of our sample, and find that there is a close match between the luminosity functions of the LSP stars and all of the stars in our sample, and that these star's pulsation amplitudes are relatively wavelength independent. Although this is characteristic of stellar multiplicity, the large number of these variables is problematic for that explanation.

  4. On the Periodic Mild Solutions to Complete Higher Order Differential Equations on

    E-Print Network [OSTI]

    Nguyen, Lan

    -periodic solution for each continuous T-periodic forcing term f if and only if k = 2kt/T, k ZZ, are not eigen-values statement generally fails. When A generates a strongly continuous semi- group, periodicity of solutions(J) denotes the space of E-valued integrable functions on J with f Lp(J) = 1 0 f(t) p dt

  5. A Low-Cost, High-Efficiency Periodic Flow Gas Turbine for Distributed Energy Generation

    SciTech Connect (OSTI)

    Dr. Adam London

    2008-06-20T23:59:59.000Z

    The proposed effort served as a feasibility study for an innovative, low-cost periodic flow gas turbine capable of realizing efficiencies in the 39-48% range.

  6. E-Print Network 3.0 - a20 regulates period Sample Search Results

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

    & Control 28 (2004) 16611680 www.elsevier.comlocateeconbase Summary: of the abatement cost function as being constant for a long period of time. If the regulator could...

  7. Computer Assisted 'Proof' of the Global Existence of Periodic Orbits in the Rssler System

    E-Print Network [OSTI]

    A. E. Botha; W. Dednam

    2014-08-14T23:59:59.000Z

    The numerical optimized shooting method for finding periodic orbits in nonlinear dynamical systems was employed to determine the existence of periodic orbits in the well-known R\\"ossler system. By optimizing the period $T$ and the three system parameters, $a$, $b$ and $c$, simultaneously, it was found that, for any initial condition $(x_0,y_0,z_0) \\in \\Re^3$, there exists at least one set of optimized parameters corresponding to a periodic orbit passing through $ (x_0,y_0,z_0)$. After a discussion of this result it was concluded that its analytical proof may present an interesting new mathematical challenge.

  8. Measuring the rotation period distribution of field M-dwarfs with Kepler

    E-Print Network [OSTI]

    McQuillan, Amy; Mazeh, Tsevi

    2013-01-01T23:59:59.000Z

    We have analysed 10 months of public data from the Kepler space mission to measure rotation periods of main-sequence stars with masses between 0.3 and 0.55 M_sun. To derive the rotational period we introduce the autocorrelation function and show that it is robust against phase and amplitude modulation and residual instrumental systematics. Of the 2483 stars examined, we detected rotation periods in 1570 (63.2%), representing an increase of a factor ~ 30 in the number of rotation period determination for field M-dwarfs. The periods range from 0.37-69.7 days, with amplitudes ranging from 1.0-140.8 mmags. The rotation period distribution is clearly bimodal, with peaks at ~ 19 and ~ 33 days, hinting at two distinct waves of star formation, a hypothesis that is supported by the fact that slower rotators tend to have larger proper motions. The two peaks of the rotation period distribution form two distinct sequences in period-temperature space, with the period decreasing with increasing temperature, reminiscent of ...

  9. EIS-0466: Re-opening of Public Scoping Period and Announcement...

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

    Public Scoping Meetings Continued Operation of the Sandia National Laboratories, New Mexico Comment Period Ends: 9122011 Submit Comments to: Ms. Jeanette Norte NNSA Sandia Site...

  10. Commensurability effects induced by a periodic array of nanoscale anti-dots in Nb superconductor

    E-Print Network [OSTI]

    Metlushko, Vitali

    Commensurability effects induced by a periodic array of nanoscale anti-dots in Nb superconductor A. PACS: 74.25.Ha; 74.76.)w Keywords: Nanostructures; Anti-dots; Commensurability 1. Introduction atomic layers on periodical substrate [5], magnetic bubble arrays [6] and the magnetically induced Wigner

  11. INVERTIBLE SUBSTITUTIONS WITH A COMMON PERIODIC HUI RAO AND ZHI-YING WEN

    E-Print Network [OSTI]

    Rao, Hui

    INVERTIBLE SUBSTITUTIONS WITH A COMMON PERIODIC POINT HUI RAO AND ZHI-YING WEN Abstract. We characterize the invertible substitutions over a two-letter alphabet which share a common periodic point (or for some n 1. A substitution is said invertible if it is an automorphism of the free group F generated

  12. ON THE EXISTENCE OF STEADY PERIODIC CAPILLARY-GRAVITY STRATIFIED WATER WAVES

    E-Print Network [OSTI]

    points for steady water waves. The condition which ensures the lack of stagnation points for 1991ON THE EXISTENCE OF STEADY PERIODIC CAPILLARY-GRAVITY STRATIFIED WATER WAVES DAVID HENRY AND BOGDANVASILE MATIOC Abstract. We prove the existence of small steady periodic capillary-gravity water waves

  13. Covariation of coastal water temperature and microbial pollution at interannual to tidal periods

    E-Print Network [OSTI]

    Winant, Clinton D.

    Covariation of coastal water temperature and microbial pollution at interannual to tidal periods, California, USA Daniel B. Lluch-Cota Centro de Investigaciones Biologicas del Noroeste, La Paz, Mexico-period cooling are coincident with elevated levels of microbial pollution in the surf zone. This relationship can

  14. Nonlinear dielectric response of periodic composite materials A. Kolpakov & A. K. Tagantsev & L. Berlyand &

    E-Print Network [OSTI]

    Berlyand, Leonid

    periodic composite (a matrix of a large dielectric constant ferro- electric material with linear dielectric of ferroelectric/dielectric composites. A typical example is a (Ba,Sr)TiO3 ceramic fabricated with addition of MgNonlinear dielectric response of periodic composite materials A. Kolpakov & A. K. Tagantsev & L

  15. Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction

    E-Print Network [OSTI]

    Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction-dimensional systems subject to a periodic force and study numer- ically how a time-varying friction affects oscillator in the presence of friction. We find that, if the damping coefficient increases in time up

  16. Multi-Period Production Capacity Planning for Integrated Product and Production System Design*

    E-Print Network [OSTI]

    Saitou, Kazuhiro "Kazu"

    Multi-Period Production Capacity Planning for Integrated Product and Production System Design* Emre.ac.uk kazu@umich.edu .Abstract This paper presents a simulation-based method to aid multi-period production capacity planning by quantifying the trade-off between product quality and production cost. The product

  17. High order asymptotics for the electromagnetic scattering from thin periodic layers : the 3D

    E-Print Network [OSTI]

    Boyer, Edmond

    High order asymptotics for the electromagnetic scattering from thin periodic layers : the 3D of electromagnetic waves by a thin periodic layer made of an array of regularly-spaced obstacles. The size, they satisfy electrostatic problems posed in an infinite 3D strip that require a careful analysis. Error

  18. Comparison of quantization of charge transport in periodic and open pumps

    E-Print Network [OSTI]

    Comparison of quantization of charge transport in periodic and open pumps G.M. Graf and G. Ortelli the charges transported in two systems, a spatially periodic and an open quantum pump, both depending physical situations become the same, i.e., that of a large open pump. 1 Introduction In this note we

  19. Program Director/Principal Investigator (Last, First, Middle): DETAILED BUDGET FOR INITIAL BUDGET PERIOD

    E-Print Network [OSTI]

    Ungerleider, Leslie G.

    Program Director/Principal Investigator (Last, First, Middle): DETAILED BUDGET FOR INITIAL BUDGET SUBTOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD (Item 7a, Face Page) $ CONSORTIUM/CONTRACTUAL COSTS FACILITIES AND ADMINISTRATIVE COSTS TOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD $ PHS 398 (Rev. 6/09) Page

  20. Program Director/Principal Investigator (Last, First, Middle): DETAILED BUDGET FOR INITIAL BUDGET PERIOD

    E-Print Network [OSTI]

    Baker, Chris I.

    Program Director/Principal Investigator (Last, First, Middle): DETAILED BUDGET FOR INITIAL BUDGET SUBTOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD (Item 7a, Face Page) $ CONSORTIUM/CONTRACTUAL COSTS FACILITIES AND ADMINISTRATIVE COSTS TOTAL DIRECT COSTS FOR INITIAL BUDGET PERIOD $ Page Form Page 4 PHS 398

  1. Approximations to wave propagation through doubly-periodic arrays of scatterers

    E-Print Network [OSTI]

    Approximations to wave propagation through doubly-periodic arrays of scatterers P. Mc Abstract The propagation of waves through a doubly-periodic array of identical rigid scatterers of matched asymptotic expansions is used to obtain the dispersion relation corresponding to wave propagation

  2. Quantum reflection and interference of matter waves from periodically doped surfaces

    E-Print Network [OSTI]

    Benjamin A. Stickler; Uzi Even; Klaus Hornberger

    2015-01-15T23:59:59.000Z

    We show that periodically doped, flat surfaces can act as reflective diffraction gratings for atomic and molecular matter waves. The diffraction element is realized by exploiting that charged dopants locally suppress quantum reflection from the Casimir-Polder potential. We present a general quantum scattering theory for reflection off periodically charged surfaces and discuss the requirements for the observation of multiple diffraction peaks.

  3. Instability inside a rotating gas cylinder subject to axial periodic strain Y. Duguet,a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of viscous flow inside a closed circular cylinder rotating about its axis, periodically compressed by meansInstability inside a rotating gas cylinder subject to axial periodic strain Y. Duguet,a J. F. Scott are known to support inertial oscillations whose frequencies are less than twice the basic rotation rate.1

  4. The role of money and monetary policy in crisis periods : the Euro

    E-Print Network [OSTI]

    Boyer, Edmond

    The role of money and monetary policy in crisis periods : the Euro area case Research Center ESSEC of money and monetary policy in crisis periods: the Euro area case Jonathan Benchimol and André Fourçansy on the role of money and monetary policy during crises. The role of separability between money and consumption

  5. Long-Term Cycles in the History of Life: Periodic Biodiversity in the Paleobiology Database

    E-Print Network [OSTI]

    Melott, Adrian L.

    2008-12-24T23:59:59.000Z

    record. Cross-spectral analysis of the two datasets finds that a 62 My periodicity coincides in phase by 1.6 My, equivalent to better than the errors in either measurement. Consequently, the two data sets not only contain the same strong periodicity...

  6. Performance Period

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergyENERGY TAXBalanced ScorecardReactorBatteries for Advanced26, 2005 The HonorableProgram |Fee

  7. An inverse free electron laser accelerator experiment

    SciTech Connect (OSTI)

    Wernick, I.; Marshall, T.C.

    1992-01-01T23:59:59.000Z

    A free electron laser was configured as an autoaccelerator to test the principle of accelerating electrons by stimulated absorption of radiation ([lambda] = 1.65mm) by an electron beam (750kV) traversing an undulator. Radiation is produced in the first section of a constant period undulator (1[sub w1] = 1.43cm) and then absorbed ([approximately] 40%) in a second undulator, having a tapered period (1[sub w2] = 1.8 [minus] 2.25cm), which results in the acceleration of a subgroup ([approximately] 9%) of electrons to [approximately] 1MeV.

  8. An inverse free electron laser accelerator experiment

    SciTech Connect (OSTI)

    Wernick, I.; Marshall, T.C.

    1992-12-31T23:59:59.000Z

    A free electron laser was configured as an autoaccelerator to test the principle of accelerating electrons by stimulated absorption of radiation ({lambda} = 1.65mm) by an electron beam (750kV) traversing an undulator. Radiation is produced in the first section of a constant period undulator (1{sub w1} = 1.43cm) and then absorbed ({approximately} 40%) in a second undulator, having a tapered period (1{sub w2} = 1.8 {minus} 2.25cm), which results in the acceleration of a subgroup ({approximately} 9%) of electrons to {approximately} 1MeV.

  9. Real world issues for the new soft x-ray synchrotron sources

    SciTech Connect (OSTI)

    Kincaid, B.M.

    1991-05-01T23:59:59.000Z

    A new generation of synchrotron radiation light sources covering the VUV, soft x-ray and hard x-ray spectral regions is under construction in several countries. They are designed specifically to use periodic magnetic undulators and low-emittance electron or positron beams to produce high-brightness near-diffraction-limited synchrotron radiation beams. An introduction to the properties of undulator radiation is followed by a discussion of some of the challenges to be faced at the new facilities. Examples of predicted undulator output from the Advanced Light Source, a third generation 1--2 GeV storage ring optimized for undulator use, are used to highlight differences from present synchrotron radiation sources, including high beam power, partial coherence, harmonics, and other unusual spectral and angular properties of undulator radiation. 8 refs., 2 figs.

  10. Solutions to Test 1 Review Problems 1. Here are two sound waves. Identify which is periodic. For the periodic wave, sketch a

    E-Print Network [OSTI]

    Hall, Rachel W.

    Solutions to Test 1 Review Problems 1. Here are two sound waves. Identify which is periodic. Sound wave = You hear a sound that fades in, then gets quiet, then gets louder, and inally fades out. The width of the sound wave corresponds to intensity. (b) Suppose a 1000 Hz tone and a 1008 Hz tone

  11. SPECTROSCOPIC EVIDENCE FOR A 5.4 MINUTE ORBITAL PERIOD IN HM CANCRI

    SciTech Connect (OSTI)

    Roelofs, Gijs H. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rau, Arne [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Marsh, Tom R.; Steeghs, Danny [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Groot, Paul J.; Nelemans, Gijs [Department of Astrophysics, Radboud University Nijmegen, P.O. Box 9010, 6500 GL, Nijmegen (Netherlands)], E-mail: groelofs@cfa.harvard.edu, E-mail: arau@mpe.mpg.de

    2010-03-10T23:59:59.000Z

    HM Cancri is a candidate ultracompact binary white dwarf with an apparent orbital period of only 5.4 minutes, as suggested by X-ray and optical light-curve modulations on that period, and by the absence of longer-period variability. In this Letter, we present Keck-I spectroscopy which shows clear modulation of the helium emission lines in both radial velocity and amplitude on the 5.4 minute period and no other. The data strongly suggest that the binary is emitting He I 4471 from the irradiated face of the cooler, less massive star, and He II 4686 from a ring around the more massive star. From their relative radial velocities, we measure a mass ratio q = 0.50 {+-} 0.13. We conclude that the observed 5.4 minute period almost certainly represents the orbital period of an interacting binary white dwarf. We thus confirm that HM Cnc is the shortest period binary star known: a unique test for stellar evolution theory, and one of the strongest known sources of gravitational waves for LISA.

  12. Formation of laser-induced periodic surface structures on niobium by femtosecond laser irradiation

    SciTech Connect (OSTI)

    Pan, A.; Dias, A.; Gomez-Aranzadi, M.; Olaizola, S. M. [CIC microGUNE, Goiru Kalea 9 Polo Innovacin Garaia, 20500 Arrasate-Mondragn (Spain); CEIT-IK4 and Tecnun, University of Navarra, Manuel Lardizbal 15, 20018 San Sebastin (Spain); Rodriguez, A. [CIC microGUNE, Goiru Kalea 9 Polo Innovacin Garaia, 20500 Arrasate-Mondragn (Spain)

    2014-05-07T23:59:59.000Z

    The surface morphology of a Niobium sample, irradiated in air by a femtosecond laser with a wavelength of 800?nm and pulse duration of 100 fs, was examined. The period of the micro/nanostructures, parallel and perpendicularly oriented to the linearly polarized fs-laser beam, was studied by means of 2D Fast Fourier Transform analysis. The observed Laser-Induced Periodic Surface Structures (LIPSS) were classified as Low Spatial Frequency LIPSS (periods about 600?nm) and High Spatial Frequency LIPSS, showing a periodicity around 300?nm, both of them perpendicularly oriented to the polarization of the incident laser wave. Moreover, parallel high spatial frequency LIPSS were observed with periods around 100?nm located at the peripheral areas of the laser fingerprint and overwritten on the perpendicular periodic gratings. The results indicate that this method of micro/nanostructuring allows controlling the Niobium grating period by the number of pulses applied, so the scan speed and not the fluence is the key parameter of control. A discussion on the mechanism of the surface topology evolution was also introduced.

  13. Propagation of travelling waves in sub-excitable systems driven by noise and periodic forcing

    E-Print Network [OSTI]

    Fen-Ni Si; Quan-Xing Liu; Jin-Zhong Zhang; Lu-Qun Zhou

    2007-11-23T23:59:59.000Z

    It has been reported that traveling waves propagate periodically and stably in sub-excitable systems driven by noise [Phys. Rev. Lett. \\textbf{88}, 138301 (2002)]. As a further investigation, here we observe different types of traveling waves under different noises and periodic forces, using a simplified Oregonator model. Depending on different noises and periodic forces, we have observed different types of wave propagation (or their disappearance). Moreover, the reversal phenomena are observed in this system based on the numerical experiments in the one-dimensional space. As an explanation, we regard it as the effect of periodic forces. Thus, we give qualitative explanations to how reversal phenomena stably appear, which seem to arise from the mixing function of the periodic force and the noise. And the output period and three velocities (the normal, the positive and the negative) of the travelling waves are defined and their relationship with the periodic forces, along with the types of waves, are also studied in sub-excitable system under a fixed noise intensity.

  14. Reconstruction of spatial patterns of climatic anomalies during the medieval warm period (AD 900-1300)

    SciTech Connect (OSTI)

    Diaz, H.F. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Environmental Research Labs.; Hughes, M.K. [Arizona Univ., Tucson, AZ (United States). Lab. of Tree-Ring Research

    1992-12-31T23:59:59.000Z

    The workshop will focus on climatic variations during the Medieval Warm Period or Little Climatic Optimum. The nominal time interval assigned to this period is AD 900--1300, but climate information available during the century or two preceding and following this episode is welcome. The aims of the workshop will be to: examine the available evidence for the existence of this episode; assess the spatial and temporal synchronicity of the climatic signals; discuss possible forcing mechanisms; and identify areas and paleoenvironmental records where additional research efforts are needed to improve our knowledge of this period. This document consists of abstracts of eighteen papers presented at the meeting.

  15. Theoretical and Computational Investigation of Periodically Focused Intense Charged-Particle Beams

    SciTech Connect (OSTI)

    Chen, Chiping [Massachusetts Institute of Technology

    2013-06-26T23:59:59.000Z

    The purpose of this report is to summarize results of theoretical and computational investigations of periodically focused intense charged-particle beams in parameter regimes relevant to the development of advanced high-brightness, high-power accelerators for high-energy physics research. The breakthroughs and highlights in our research in the period from April 1, 2010 to March 30, 2013 were: a) Theory and simulation of adiabatic thermal Child-Langmuir flow; b) Particle-in-cell simulations of adiabatic thermal beams in periodic solenoidal focusing field; c)Dynamics of charged particles in an adiabatic thermal beam equilibrium in a periodic solenoidal focusing field; d) Training of undergraduate researchers and graduate student in accelerator and beam physics. A brief introduction and summary is presented. Detailed descriptions of research results are provided in an appendix of publications at the end of the report.

  16. June 15, 1996 / Vol. 21, No. 12 / OPTICS LETTERS 857 Photorefractive effects in periodically poled ferroelectrics

    E-Print Network [OSTI]

    Fejer, Martin M.

    - conversion interactions.2 5 There have been several reports that periodically poled lithium niobate (PPLN s is a parameter that depends on the properties of the host crystal, donors, and traps and nd is the dark

  17. DOE Extends Comment Period on Notice of Inquiry Under the Energy...

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

    - 10:17am Addthis Today, in response to a formal request, General Counsel Scott Blake Harris approved a second and final extension of the public comment period to November 30,...

  18. DOE Extends Comment Period on Notice of Inquiry Under the Energy...

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

    - 4:33pm Addthis Today, in response to a formal request, General Counsel Scott Blake Harris approved a 30-day extension of the public comment period on DOE's Notice of Inquiry...

  19. Homogenization approach for the transmission eigenvalue problem for periodic media and application to the inverse problem

    E-Print Network [OSTI]

    Fioralba Cakoni; Houssem Haddar; Isaac Harris

    2014-10-14T23:59:59.000Z

    We consider the interior transmission problem associated with the scattering by an inhomogeneous (possibly anisotropic) highly oscillating periodic media. We show that, under appropriate assumptions, the solution of the interior transmission problem converges to the solution of a homogenized problem as the period goes to zero. Furthermore, we prove that the associated real transmission eigenvalues converge to transmission eigenvalues of the homogenized problem. Finally we show how to use the first transmission eigenvalue of the period media, which is measurable from the scattering data, to obtain information about constant effective material properties of the periodic media. The convergence results presented here are not optimal. Such results with rate of convergence involve the analysis of the boundary correction and will be subject of a forthcoming paper.

  20. Use and Finance BiAnnual Reporting Form Reporting Period: July 2013 through December 2013

    E-Print Network [OSTI]

    Papalambros, Panos

    Use and Finance BiAnnual Reporting Form Reporting Period: July 2013 through December 2013 $ Other (Professional Fees, Telecommunications, Moving) 538,200$ Other (Finance resources services center will be established for finance and human resources transaction processing activities

  1. Semiclassical analysis for a Schrodinger operator with a U(2) artificial gauge: the periodic case

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    : semiclassical asymptotic, spectrum, eigenvalues, Schrodinger, periodic potential, BKW method, width of the first Preliminary: the artificial gauge model 3 3 Proof of Theorem 2.1 5 4 Asymptotic of the first band 6 5 B.K.W

  2. Semiclassical analysis for a Schrodinger operator with a U(2) artificial gauge: the periodic case

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    : semiclassical asymptotic, spectrum, eigenvalues, Schrodinger, periodic potential, BKW method, width of the first Preliminary: the artificial gauge model 3 3 Proof of Theorem 2.1 5 4 Asymptotic of the first band 7 5 B.K.W

  3. Case Study of Optimal Byproduct Gas Distribution in Integrated Steel Mill Using Multi-Period Optimization

    E-Print Network [OSTI]

    Makinen, K.; Kymalainen, T.; Junttila, J.

    2012-01-01T23:59:59.000Z

    ? ? ? Case Study of Optimal Byproduct Gas Distribution in Integrated Steel Mill Using Multi-Period Optimization KIMMO M?KINEN BUSINESS MANAGER TONI KYM?L?INEN PRODUCT MANAGER JAAKKO JUNTTILA SALES MANAGER ABB OY HELSINKI FINLAND...

  4. An MILP approach to Multi-location, Multi-Period Equipment ...

    E-Print Network [OSTI]

    2013-06-24T23:59:59.000Z

    Jun 24, 2013 ... problem for the mining industry due to the large cost of purchasing and ..... production capability is determined by its availability (al ..... As a power ..... all periods is 8% (the approximate interest rate obtainable on investments).

  5. CO2 Abatement in the UK Power Sector: Evidence from the EU ETS Trial Period

    E-Print Network [OSTI]

    Ellerman, A. Denny

    2008-01-01T23:59:59.000Z

    This paper provides an empirical assessment of CO2 emissions abatement in the UK power sector during the trial period of the EU ETS. Using an econometrically estimated model of fuel switching, it separates the impacts of ...

  6. E-Print Network 3.0 - abstracts search period Sample Search Results

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

    the period you wish to search. 12;2 PsycINFO user guide September 2002 Enter your search term or terms... PsycINFO user guide citations summaries abstracts journal...

  7. Mediterraneit and modernit : architecture and culture during the period of Italian colonization of North Africa

    E-Print Network [OSTI]

    McLaren, Brian L. (Brian Lloyd), 1958-

    2001-01-01T23:59:59.000Z

    This dissertation examines the intersection of the modern and the colonial in architecture and culture during the period of Italian colonization of North Africa from 1911 to 1943. Rather than see the colonies as merely a ...

  8. Quarterly RCRA Groundwater Monitoring Data for the Period July through September 2006

    SciTech Connect (OSTI)

    Hartman, Mary J.

    2007-02-01T23:59:59.000Z

    This report provides information about RCRA groundwater monitoring for the period July through September 2006. Eighteen Resource Conservation and Recovery Act (RCRA) sites were sampled during the reporting quarter.

  9. Geothermal R and D Project report for period April 1, 1976 to...

    Open Energy Info (EERE)

    search OpenEI Reference LibraryAdd to library Report: Geothermal R and D Project report for period April 1, 1976 to June 30, 1976 Abstract Progress during April to July...

  10. Homogenized dynamic constitutive relation for Bloch-wave propagation in periodic composites: structure and symmetries

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    Homogenized dynamic constitutive relation for Bloch-wave propagation in periodic composites composites has been made only very recently. Here we discuss the explicit form of the effective dynamic properties of composites with tailored microstructure necessitates a systematic homogenization procedure

  11. Ergodic theory and visualization. II. Harmonic mesochronic plots visualize (quasi)periodic sets

    E-Print Network [OSTI]

    Zoran Levnaji?; Igor Mezi?

    2014-07-26T23:59:59.000Z

    We present a new method of analysis of measure-preserving dynamical systems, based on frequency analysis and ergodic theory, which extends our earlier work [1]. Our method employs the novel concept of harmonic time average [2], and is realized as a computational algorithms for visualization of periodic and quasi-periodic sets or arbitrary periodicity in the phase space. Besides identifying all periodic sets, our method is useful in detecting chaotic phase space regions with a good precision. The range of method's applicability is illustrated using well-known Chirikov standard map, while its full potential is presented by studying higher-dimensional measure-preserving systems, in particular Froeschl\\'e map and extended standard map.

  12. Public Comment Period for Portsmouth Site D&D and Waste Disposition...

    Office of Environmental Management (EM)

    2014 8:00AM EST to March 11, 2015 5:00PM EDT Public Comment Period for the Process Buildings and Complex Facilities Decontamination and Decommissioning and Site-Wide Waste...

  13. An ubiquitous ~62 Myr periodic fluctuation superimposed on general trends in fossil biodiversity: Part I, Documentation

    E-Print Network [OSTI]

    Melott, Adrian L

    2010-01-01T23:59:59.000Z

    We use Fourier Analysis and related techniques to investigate the question of periodicities in fossil biodiversity. These techniques are able to identify cycles superimposed on the long-term trends of the Phanerozoic. We review prior results and analyze data previously reduced and published. Joint time series analysis of various reductions of the Sepkoski Data, Paleobiology Database, and Fossil Record 2 indicate the same periodicity in biodiversity of marine animals at 62 Myr. We have not found this periodicity in the terrestrial fossil record. We have found that the signal strength decreases with time because of the accumulation of apparently "resistant" long-lived genera. The existence of a 62 Myr periodicity despite very different treatment of systematic error, particularly sampling-strength biases, in all three major databases strongly argues for its reality in the fossil record.

  14. Considering the Case for Biodiversity Cycles: Reexamining the Evidence for Periodicity in the Fossil Record

    E-Print Network [OSTI]

    Lieberman, Bruce S

    2007-01-01T23:59:59.000Z

    Medvedev and Melott (2007) have suggested that periodicity in fossil biodiversity may be induced by cosmic rays which vary as the Solar System oscillates normal to the galactic disk. We re-examine the evidence for a 62 million year (Myr) periodicity in biodiversity throughout the Phanerozoic history of animal life reported by Rohde & Mueller (2005), as well as related questions of periodicity in origination and extinction. We find that the signal is robust against variations in methods of analysis, and is based on fluctuations in the Paleozoic and a substantial part of the Mesozoic. Examination of origination and extinction is somewhat ambiguous, with results depending upon procedure. Origination and extinction intensity as defined by RM may be affected by an artifact at 27 Myr in the duration of stratigraphic intervals. Nevertheless, when a procedure free of this artifact is implemented, the 27 Myr periodicity appears in origination, suggesting that the artifact may ultimately be based on a signal in the...

  15. The effect of disorder on the wave propagation in one-dimensional periodic optical systems

    E-Print Network [OSTI]

    Yuri A. Godin; Stanislav Molchanov; Boris Vainberg

    2011-10-18T23:59:59.000Z

    The influence of disorder on the transmission through periodic waveguides is studied. Using a canonical form of the transfer matrix we investigate dependence of the Lyapunov exponent $\\gamma$ on the frequency $\

  16. The effect of periodic-unsteady wakes, curvature, and pressure gradient on boundary-layer transition

    E-Print Network [OSTI]

    Radke, Robert Edward

    1994-01-01T23:59:59.000Z

    Boundary-layer transition on a concave curved plate has been investigated with and without periodic-unsteady inlet flow at zero and negative pressure gradients. The periodicunsteady wakes were created using a rotating squirrel-cage type wake...

  17. E-Print Network 3.0 - afterwreck postemergency period Sample...

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

    Ally 60 DF Apply one application in a 22 month period. Crop rotations: corn 22 months, cotton 22 months... . Sorghum 10 months, other crops 34 months. Recommended to be applied...

  18. Einstein@Home search for periodic gravitational waves in early S5 LIGO data

    E-Print Network [OSTI]

    Barsotti, Lisa

    This paper reports on an all-sky search for periodic gravitational waves from sources such as deformed isolated rapidly spinning neutron stars. The analysis uses 840 hours of data from 66 days of the fifth LIGO science run ...

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

    E-Print Network [OSTI]

    Zucker, Michael E.

    A search for periodic gravitational waves, from sources such as isolated rapidly spinning neutron stars, was carried out using 510 h of data from the fourth LIGO science run (S4). The search was for quasimonochromatic waves ...

  20. Simulation of adiabatic thermal beams in a periodic solenoidal magnetic focusing field

    E-Print Network [OSTI]

    Barton, T. J.

    Self-consistent particle-in-cell simulations are performed to verify earlier theoretical predictions of adiabatic thermal beams in a periodic solenoidal magnetic focusing field [ K.?R. Samokhvalova, J. Zhou and C. Chen ...

  1. Periodic orbit bifurcations as an ionization mechanism: The bichromatically driven hydrogen atom

    E-Print Network [OSTI]

    S. Huang; C. Chandre; T. Uzer

    2007-12-17T23:59:59.000Z

    We investigate the multiphoton ionization of hydrogen driven by a strong bichromatic microwave field. In a regime where classical and quantum simulations agree, periodic orbit analysis captures the mechanism: Through the linear stability of periodic orbits we match qualitatively the variation of experimental ionization rates with control parameters such as the amplitudes of the two modes of the field or their relative phases. Moreover, we discuss an empirical formula which reproduces quantum simulations to a high degree of accuracy. This quantitative agreement shows the mechanism by which short periodic orbits organize the dynamics in multiphoton ionization. We also analyze the effect of longer pulse durations. Finally we compare our results with those based on the peak amplitude rule. Both qualitative and quantitative analyses are implemented for different mode locked fields. In parameter space, the localization of the period doubling and halving allows one to predict the set of parameters (amplitudes and phase lag) where ionization occurs.

  2. Quantized Spiral Tip Motion in Excitable Systems with Periodic Heterogeneities Brent T. Ginn and Oliver Steinbock*

    E-Print Network [OSTI]

    Steinbock, Oliver

    and frequencies that exhibit a devil's staircase. The plateaus of the staircase correspond to pinned or complex length. These quantized orbits follow a devil's staircase [10] as the refractory period of the sys- tem

  3. Short period fluctuations of sea level in the West Florida Keys

    E-Print Network [OSTI]

    Hsu, Sangem

    1978-01-01T23:59:59.000Z

    of Sea Level in the West Florida Keys (December, 1978) Sangem Hsu, B. S. , Taiwan Provincial College of Marine and Oceanic Technology. Chairman of Advisory Committee: Dr. Takashi Ichiye In addition to oscillations of astronomical origin, tidal... records often contain shorter or longer period oscillations. Short period oscillations usually have very small amplitudes and often cannot be recognized in the tidal records except near crests or troughs at days of calm weather. The purposes...

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

    SciTech Connect (OSTI)

    NONE

    1999-12-31T23:59:59.000Z

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

  5. Effect of the hepatoma growth period on host plasma and liver lipid concentrations

    E-Print Network [OSTI]

    Matocha, Martha Frances

    1979-01-01T23:59:59.000Z

    EFFECT OF THE HEPATOMA GROWTH PERIOD ON HOST PLASMA AND LIVER LIPID CONCENTRATIONS A Thesis by MARTHA FRANCES MATOCHA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE August 1979 Niajor Sub ect: Biochem. 'stry EFFECT OF THE HEPATOMA GROWTH PERIOD ON HOST PLASMA AND LIVER LIPID CONCENTRATIONS A Thesis MARTHA FRANCES MATOCHA Approved as to style and content by: (Chairman of Committee) (Mern...

  6. 3D periodic dielectric composite homogenization based on the Generalized Source Method

    E-Print Network [OSTI]

    Shcherbakov, Alexey A

    2015-01-01T23:59:59.000Z

    The article encloses a new Fourier space method for rigorous optical simulation of 3D periodic dielectric structures. The method relies upon rigorous solution of Maxwell's equations in complex composite structures by the Generalized Source Method. Extremely fast GPU enabled calculations provide a possibility for an efficient search of eigenmodes in 3D periodic complex structures on the basis of rigorously obtained resonant electromagnetic response. The method is applied to the homogenization problem demonstrating a complete anisotropic dielectric tensor retrieval.

  7. Comparison of quantization of charge transport in periodic and open pumps

    E-Print Network [OSTI]

    Gian Michele Graf; Gregorio Ortelli

    2007-09-19T23:59:59.000Z

    We compare the charges transported in two systems, a spatially periodic and an open quantum pump, both depending periodically and adiabatically on time. The charge transported in a cycle was computed by Thouless, respectively by Buttiker et al. in the two cases. We show that the results agree in the limit where the two physical situations become the same, i.e., that of a large open pump.

  8. Spatial Periodic Forcing Can Displace Patterns It Is Intended to Control

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

    Mau, Yair; Hagberg, Aric; Meron, Ehud

    2012-07-01T23:59:59.000Z

    Spatial periodic forcing of pattern-forming systems is an important, but lightly studied, method of controlling patterns. It can be used to control the amplitude and wave number of one-dimensional periodic patterns, to stabilize unstable patterns, and to induce them below instability onset. We show that, although in one spatial dimension the forcing acts to reinforce the patterns, in two dimensions it acts to destabilize or displace them by inducing two-dimensional rectangular and oblique patterns.

  9. Considering the Case for Biodiversity Cycles: Reexamining the Evidence for Periodicity in the Fossil Record

    E-Print Network [OSTI]

    Bruce S. Lieberman; Adrian L. Melott

    2007-08-22T23:59:59.000Z

    Medvedev and Melott (2007) have suggested that periodicity in fossil biodiversity may be induced by cosmic rays which vary as the Solar System oscillates normal to the galactic disk. We re-examine the evidence for a 62 million year (Myr) periodicity in biodiversity throughout the Phanerozoic history of animal life reported by Rohde & Mueller (2005), as well as related questions of periodicity in origination and extinction. We find that the signal is robust against variations in methods of analysis, and is based on fluctuations in the Paleozoic and a substantial part of the Mesozoic. Examination of origination and extinction is somewhat ambiguous, with results depending upon procedure. Origination and extinction intensity as defined by RM may be affected by an artifact at 27 Myr in the duration of stratigraphic intervals. Nevertheless, when a procedure free of this artifact is implemented, the 27 Myr periodicity appears in origination, suggesting that the artifact may ultimately be based on a signal in the data. A 62 Myr feature appears in extinction, when this same procedure is used. We conclude that evidence for a periodicity at 62 Myr is robust, and evidence for periodicity at approximately 27 Myr is also present, albeit more ambiguous.

  10. Development of Advanced Concept for Shortening Construction Period of ABWR Plant

    SciTech Connect (OSTI)

    Hiroshi Ijichi; Toshio Yamashita; Masahiro Tsutagawa; Hiroya Mori [Toshiba Corporation (Japan); Nobuaki Ooshima; Jun Miura [Hitachi Ltd. (Japan); Minoru Kanechika [Kajima Corporation (Japan); Nobuaki Miura [Shimizu Corporation (Japan)

    2002-07-01T23:59:59.000Z

    Construction of a nuclear power plant (NPP) requires a very long period because of large amount of construction materials and many issues for negotiation among multiple sections. Shortening the construction period advances the date of return on an investment, and can also result in reduced construction cost. Therefore, the study of this subject has a very high priority for utilities. We achieved a construction period of 37 months from the first concrete work to fuel loading (F/L) (51.5 months from the inspection of the foundation (I/F) to the start of commercial operation (C/O)) at the Kashiwazaki-Kariwa NPPs No. 6 and 7 (KK-6/7), which are the first ABWR plants in the world. At TEPCO's next plant, we think that a construction period of less than 36 months (45 months from I/F to C/O) can be realized based on conventional methods such as early start of equipment installation and blocking of equipment to be brought in advance. Furthermore, we are studying the feasibility of a 21.5-month construction period (30 months from I/F to C/O) with advanced ideas and methods. The important concepts for a 21.5-month construction period are adoption of a new building structure that is the steel plate reinforced concrete (SC) structure and promotion of extensive modularization of equipment and building structure. With introducing these new concepts, we are planning the master schedule (M/S) and finding solutions to conflicts in the schedule of area release from building construction work to equipment installation work (schedule-conflicts.) In this report, we present the shortest construction period and an effective method to put it into practice for the conventional general arrangement (GA) of ABWR. In the future, we will continue the study on the improvement of building configuration and arrangements, and make clear of the concept for large composite modules of building structures and equipment. (authors)

  11. EVOLUTIONARY TRACKS OF TRAPPED, ACCRETING PROTOPLANETS: THE ORIGIN OF THE OBSERVED MASS-PERIOD RELATION

    SciTech Connect (OSTI)

    Hasegawa, Yasuhiro [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Pudritz, Ralph E., E-mail: hasegay@physics.mcmaster.ca, E-mail: pudritz@physics.mcmaster.ca [Origins Institute, McMaster University, Hamilton, ON L8S 4M1 (Canada)

    2012-12-01T23:59:59.000Z

    The large number of observed exoplanets ({approx}>700) provides important constraints on their origin as deduced from the mass-period diagram of planets. The most surprising features in the diagram are (1) the (apparent) pileup of gas giants at a period of {approx}500 days ({approx}1 AU) and (2) the so-called mass-period relation, which indicates that planetary mass is an increasing function of orbital period. We construct the evolutionary tracks of growing planets at planet traps in evolving protoplanetary disks and show that they provide a good physical understanding of how these observational properties arise. The fundamental feature of our model is that inhomogeneities in protoplanetary disks give rise to multiple (up to 3) trapping sites for rapid (type I) planetary migration of planetary cores. The viscous evolution of disks results in the slow radial movement of the traps and their cores from large to small orbital periods. In our model, the slow inward motion of planet traps is coupled with the standard core accretion scenario for planetary growth. As planets grow, type II migration takes over. Planet growth and radial movement are ultimately stalled by the dispersal of gas disks via photoevaporation. Our model makes a number of important predictions: that distinct sub-populations of planets that reflect the properties of planet traps where they have grown result in the mass-period relation, that the presence of these sub-populations naturally explains a pileup of planets at {approx}1 AU, and that evolutionary tracks from the ice line do put planets at short periods and fill an earlier claimed {sup p}lanet desert{sup -}a sparse population of planets in the mass-semimajor axis diagram.

  12. THE SPECTROSCOPIC SIGNATURE OF QUASI-PERIODIC UPFLOWS IN ACTIVE REGION TIMESERIES

    SciTech Connect (OSTI)

    Tian Hui; McIntosh, Scott W. [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 8037 (United States); De Pontieu, Bart, E-mail: htian@ucar.edu, E-mail: mscott@ucar.edu, E-mail: bdp@lmsal.com [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street, Org. ADBS, Bldg. 252, Palo Alto, CA 94304 (United States)

    2011-02-01T23:59:59.000Z

    Quasi-periodic propagating disturbances are frequently observed in coronal intensity image sequences. These disturbances have historically been interpreted as being the signature of slow-mode magnetoacoustic waves propagating into the corona. The detailed analysis of Hinode EUV Imaging Spectrometer (EIS) timeseries observations of an active region (known to contain propagating disturbances) shows strongly correlated, quasi-periodic, oscillations in intensity, Doppler shift, and line width. No frequency doubling is visible in the latter. The enhancements in the moments of the line profile are generally accompanied by a faint, quasi-periodically occurring, excess emission at {approx}100 km s{sup -1} in the blue wing of coronal emission lines. The correspondence of quasi-periodic excess wing emission and the moments of the line profile indicates that repetitive high-velocity upflows are responsible for the oscillatory behavior observed. Furthermore, we show that the same quasi-periodic upflows can be directly identified in a simultaneous image sequence obtained by the Hinode X-Ray Telescope. These results are consistent with the recent assertion of De Pontieu and McIntosh that the wave interpretation of the data is not unique. Indeed, given that several instances are seen to propagate along the direction of the EIS slit that clearly shows in-phase, quasi-periodic variations of intensity, velocity, width (without frequency doubling), and blue wing enhanced emission, this data set would appear to provide a compelling example that upflows are more likely to be the main cause of the quasi-periodicities observed here, as such correspondences are hard to reconcile in the wave paradigm.

  13. Analysis of electromagnetic scattering by nearly periodic structures: an LDRD report.

    SciTech Connect (OSTI)

    Johnson, William Arthur; Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Wilton, Donald R. (University of Houston, Houston, TX); Basilio, Lorena I.; Peters, David William; Capolino, F. (University of Houston, Houston, TX)

    2006-10-01T23:59:59.000Z

    In this LDRD we examine techniques to analyze the electromagnetic scattering from structures that are nearly periodic. Nearly periodic could mean that one of the structure's unit cells is different from all the others--a defect. It could also mean that the structure is truncated, or butted up against another periodic structure to form a seam. Straightforward electromagnetic analysis of these nearly periodic structures requires us to grid the entire structure, which would overwhelm today's computers and the computers in the foreseeable future. In this report we will examine various approximations that allow us to continue to exploit some aspects of the structure's periodicity and thereby reduce the number of unknowns required for analysis. We will use the Green's Function Interpolation with a Fast Fourier Transform (GIFFT) to examine isolated defects both in the form of a source dipole over a meta-material slab and as a rotated dipole in a finite array of dipoles. We will look at the numerically exact solution of a one-dimensional seam. In order to solve a two-dimensional seam, we formulate an efficient way to calculate the Green's function of a 1d array of point sources. We next formulate ways of calculating the far-field due to a seam and due to array truncation based on both array theory and high-frequency asymptotic methods. We compare the high-frequency and GIFFT results. Finally, we use GIFFT to solve a simple, two-dimensional seam problem.

  14. Long-term cycles in the history of life: Periodic biodiversity in the Paleobiology Database

    E-Print Network [OSTI]

    Adrian L. Melott

    2008-12-24T23:59:59.000Z

    Time series analysis of fossil biodiversity of marine invertebrates in the Paleobiology Database (PBDB) shows a significant periodicity at approximately 63 My, in agreement with previous analyses based on the Sepkoski database. I discuss how this result did not appear in a previous analysis of the PBDB. The existence of the 63 My periodicity, despite very different treatment of systematic error in both PBDB and Sepkoski databases strongly argues for consideration of its reality in the fossil record. Cross-spectral analysis of the two datasets finds that a 62 My periodicity coincides in phase by 1.6 My, equivalent to better than the errors in either measurement. Consequently, the two data sets not only contain the same strong periodicity, but its peaks and valleys closely correspond in time. Two other spectral peaks appear in the PBDB analysis, but appear to be artifacts associated with detrending and with the increased interval length. Sampling-standardization procedures implemented by the PBDB collaboration suggest that the signal is not an artifact of sampling bias. Further work should focus on finding the cause of the 62 My periodicity.

  15. Chemical Technology Division progress report for the period April 1, 1985 to December 31, 1986

    SciTech Connect (OSTI)

    Not Available

    1987-08-01T23:59:59.000Z

    This progress report summarizes the research and development efforts conducted in the Chemical Technology Division (Chem Tech) during the period April 1, 1985, through December 31, 1986. The following major areas are covered in the discussion: nuclear and chemical waste management, environmental control technology, basic science and technology, biotechnology research, transuranium-element processing, Nuclear Regulatory Commission programs, radioactive materials production, computer/engineering applications, fission energy, environmental cleanup projects, and various other work activities. As an appendix, the Administrative Summary presents a comprehensive compilation of publications, oral presentations, awards and recognitions, and patents of Chem Tech staff members during this report period. An organization chart, a staffing level and financial summary, and lists of seminars and Chem Tech consultants for the period are also included to provide additional information. 78 figs., 40 tabs.

  16. Controlled motion of Janus particles in periodically phase-separating binary fluids

    E-Print Network [OSTI]

    Takeaki Araki; Shintaro Fukai

    2015-04-03T23:59:59.000Z

    We numerically investigate the propelled motions of a Janus particle in a periodically phase-separating binary fluid mixture. In this study, the surface of the particle tail prefers one of the binary fluid components and the particle head is neutral in the wettability. During the demixing period, the more wettable phase is selectively adsorbed to the particle tail. Growths of the adsorbed domains induce the hydrodynamic flow in the vicinity of the particle tail, and this asymmetric pumping flow drives the particle toward the particle head. During the mixing period, the particle motion almost ceases because the mixing primarily occurs via diffusion and the resulting hydrodynamic flow is negligibly small. Repeating this cycle unboundedly moves the Janus particle toward the head. The dependencies of the composition and the repeat frequency on the particle motion are discussed.

  17. X-ray Variability and Period Determinations in the Eclipsing Polar DP Leo

    E-Print Network [OSTI]

    C. R. Robinson; F. A. Cordova

    1994-08-15T23:59:59.000Z

    An analysis of ROSAT observations for the eclipsing magnetic cataclysmic binary DP Leo provides constraints on the origin, size, temperature, variability and structure of the soft X-ray emission region on the surface of the white dwarf. These data, when combined with prior observations, show a progression of approximately 2 degrees per year in the impact position of the accretion stream onto the white dwarf. One explanation for the observed drift in stream position is that a magnetic activity cycle on the secondary produces orbital period oscillations. These oscillations result in an orbital period which cycles above and below the rotational period of the nearly synchronous white dwarf. The accretion stream and X-ray emission regions are modeled to fit the observational data. A distance to the system is also calculated. [An erroneous value for the cyclotron luminosity, included in an earlier paper version of the preprint, is corrected here.

  18. Time-periodic solitons in a damped-driven nonlinear Schrdinger equation

    E-Print Network [OSTI]

    I. V. Barashenkov; E. V. Zemlyanaya; T. C. van Heerden

    2011-03-18T23:59:59.000Z

    Time-periodic solitons of the parametrically driven damped nonlinear Schr\\"odinger equation are obtained as solutions of the boundary-value problem on a two-dimensional spatiotemporal domain. We follow the transformation of the periodic solitons as the strength of the driver is varied. The resulting bifurcation diagrams provide a natural explanation for the overall form and details of the attractor chart compiled previously via direct numerical simulations. In particular, the diagrams confirm the occurrence of the period-doubling transition to temporal chaos for small values of dissipation and the absence of such transitions for larger dampings. This difference in the soliton's response to the increasing driving strength can be traced to the difference in the radiation frequencies in the two cases. Finally, we relate the soliton's temporal chaos to the homoclinic bifurcation.

  19. Periodic and quasiperiodic motions of many particles falling in a viscous fluid

    E-Print Network [OSTI]

    Gruca, Marta; Ekiel-Jezewska, Maria L

    2015-01-01T23:59:59.000Z

    Dynamics of regular clusters of many non-touching particles falling under gravity in a viscous fluid at low Reynolds number are analysed within the point-particle model. Evolution of two families of particle configurations is determined: 2 or 4 regular horizontal polygons (called `rings') centred above or below each other. Two rings fall together and periodically oscillate. Four rings usually separate from each other with chaotic scattering. For hundreds of thousands of initial configurations, a map of the cluster lifetime is evaluated, where the long-lasting systems are centred around periodic solutions for the relative motions. The results illustrate that the existence of periodic solutions is essential for clustering of many sedimenting particles.

  20. Broadband asymmetric acoustic transmission by a plate with quasi-periodic surface ridges

    SciTech Connect (OSTI)

    Li, Chunhui; Ke, Manzhu, E-mail: mzke@whu.edu.cn; Ye, Yangtao; Xu, Shengjun; Qiu, Chunyin; Liu, Zhengyou [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China)

    2014-07-14T23:59:59.000Z

    In this paper, an acoustic system with broadband asymmetric transmission is designed and fabricated, which consists of a water-immersed aluminum plate engraved with quasi-periodically-patterned ridges on single surface. It demonstrates that when the acoustic waves are launched into the system from the structured side, they can couple into the Lamb modes in the plate efficiently and attain a high transmission; on the contrary, when the waves are incident from the opposite flat side, the coupling is weak, and the transmission is low. Superior to systems with periodic patterning, this quasi-periodically-patterned system has a broad working frequency range due to the collective contributions from the multiple diffractions specific to the structure.

  1. Complex modes and new amplification regimes in periodic multi transmission lines interacting with an electron beam

    E-Print Network [OSTI]

    Othman, Mohamed; Capolino, Filippo

    2014-01-01T23:59:59.000Z

    We show the existence of a new regime of operation for travelling wave tubes (TWTs) composed of slow-wave periodic structures that support two or more electromagnetic modes, with at least two synchronized with an electron beam. The interaction between the slow-wave structure and an electron beam is quantified using a multi transmission line approach (MTL) and transfer matrix analysis leading to the identification of modes with complex Bloch wavenumber. In particular, we report a new operation condition for TWTs based on an electron beam synchronous to two modes exhibiting a degeneracy condition near a band edge in a MTL slow-wave periodic structure. We show a phenomenological change in the band structure of periodic TWT where we observe at least two growing modal cooperating solutions as opposed to a uniform MTL interacting with an electron beam where there is strictly only one growing mode solution.

  2. Mode propagation and absorption loss in metal-clad periodic optical waveguides

    SciTech Connect (OSTI)

    Chunsheng Ma [Jilin Univ., Changchun (China)

    1996-02-01T23:59:59.000Z

    In terms of the mode eigenvalue equations are field distributions, calculations are performed for Au/InGaAsP/InP, air/Au/InGaAsP/InP, and Au/DiO{sub 2}InGaAsP/InP periodic optical waveguides. On the basis of the computed results, the coupling property in the periodic structure is analyzed, the mode split and the mode band formation of both TE and TM guided modes are described, and the effects of the thickness of the metal cladding and the oxide buffer layer on mode propagation and absorption loss are discussed for TE and TM guided modes as well as for the TM surface-plasma mode. Furthermore, the conversion from the surface-plasma wave to the guided wave for the TM mode is explained for Au/SiO{sub 2}/InGaAsP/InP periodic structures. 27 refs., 8 figs.

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

    SciTech Connect (OSTI)

    Tonn, Bruce Edward [ORNL; Rose, Erin M [ORNL; Schmoyer, Richard L [ORNL; Eisenberg, Joel Fred [ORNL; Ternes, Mark P [ORNL; Schweitzer, Martin [ORNL; Hendrick, Timothy P [ORNL

    2012-08-01T23:59:59.000Z

    This report describes the third major evaluation of the Program, encompassing program years 2009 to 2011. In this report, this period of time is referred to as the ARRA Period. This is a special period of time for the Program because the American Recovery and Reinvestment Act (ARRA) of 2009 has allocated $5 billion of funding for the Program. In normal program years, WAP s annual appropriation is in the range of $200-250 million, supporting the weatherization of approximately 100,000 homes. With the addition of ARRA funding during these program years, the expectation is that weatherization activity will exceed 300,000 homes per year. In addition to saving energy and reducing low-income energy bills, expanded WAP funding is expected to stimulate the economy by providing new jobs in the weatherization field and allowing low-income households to spend more money on goods and services by spending less on energy.

  4. Ultrashort-period MS eclipsing systems. New observations and light curve solutions of six NSVS binaries

    E-Print Network [OSTI]

    Dimitrov, Dinko

    2015-01-01T23:59:59.000Z

    We carried out photometric and low-resolution spectral observations of six eclipsing ultrashort-period binaries with MS components. The light curve solutions of the Rozhen observations show that all targets are overcontact systems. We found well-defined empirical relation "period -- semi-major axis" for the short-period binaries and used it for estimation of the global parameters of the targets. Our results revealed that NSVS 925605 is quite interesting target: (a) it is one of a few contact binaries with M components; (b) it exhibits high activity (emission in H$\\alpha$ line, X-ray emission, large cool spots, non-Planck energy distribution); (c) its components differ in temperature by 700 K. All appearances of high magnetic activity and huge fillout factor (0.7) of NSVS 925605 might be assumed as a precursor of the predicted merging of close magnetic binaries. Another unusual binary is NSVS 2700153 which reveals considerable long-term variability.

  5. Long-Period Objects in the Extrasolar Planetary Systems 47 UMa and 14 Her

    E-Print Network [OSTI]

    Robert A. Wittenmyer; Michael Endl; William D. Cochran

    2006-09-05T23:59:59.000Z

    The possible existence of additional long-period planetary-mass objects in the extrasolar planetary systems 47 UMa and 14 Her is investigated. We combine all available radial-velocity data on these stars, spanning up to 18 years. For the 47 UMa system, we show that while a second planet improves the fit to all available data, there is still substantial ambiguity as to the orbital parameters of the proposed planetary companion 47 UMa c. We also present new observations which clearly support a long-period companion in the 14 Her system. With a period of 6906+/-70 days, 14 Her c may be in a 4:1 resonance with the inner planet. We also present revised orbital solutions for 7 previously known planets incorporating recent additional data obtained with the 2.7m Harlan J. Smith Telescope at McDonald Observatory.

  6. Energy Efficiency Program for Residential Products: Energy Conservation Standards for Residential Dishwashers, Reopening of the Comment Period

    Broader source: Energy.gov [DOE]

    Energy Efficiency Program for Residential Products: Energy Conservation Standards for Residential Dishwashers, Reopening of the Comment Period

  7. Neurogenic period of ascending tract neurons in the upper lumbar spinal cord of the rat

    SciTech Connect (OSTI)

    Nandi, K.N.; Beal, J.A.; Knight, D.S. (Louisiana State Univ. Medical Center, Shreveport (USA))

    1990-02-01T23:59:59.000Z

    Although the neurogenic period for neurons in the lumbar spinal cord has been clearly established (Days 12 through 16 of gestation), it is not known when the neurogenesis of ascending tract neurons is completed within this period. The purpose of the present study was to determine the duration of the neurogenic period for projection neurons of the ascending tracts. To label neurons undergoing mitosis during this period, tritiated thymidine was administered to fetal rats on Embryonic (E) Days E13 through E16 of gestation. Ascending tract neurons of the lumbar cord were later (Postnatal Days 40-50) labeled in each animal with a retrograde tracer, Fluoro-Gold, applied at the site of a hemisection at spinal cord segment C3. Ascending tract neurons which were undergoing mitosis in the upper lumbar cord were double labeled, i.e., labeled with both tritiated thymidine and Fluoro-Gold. On Day E13, 89-92% of the ascending tract neurons were double labeled; on Day E14, 35-37%; and on Day E15, 1-4%. Results showed, then, that some ascending tract neurons were double labeled through Day E15 and were, therefore, proliferating in the final one-third of the neurogenic period. Ascending tract neurons proliferating on Day E15 were confined to laminae III, IV, V, and X and the nucleus dorsalis. Long tract neurons in the superficial dorsal horn (laminae I and II), on the other hand, were found to have completed neurogenesis on Day E14 of gestation. Results of the present study show that spinal neurogenesis of ascending projection neurons continues throughout most of the neurogenic period and does not completely follow the well-established ventral to dorsal gradient.

  8. Quantization and 2{pi} periodicity of the axion action in topological insulators

    SciTech Connect (OSTI)

    Vazifeh, M. M.; Franz, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada)

    2010-12-15T23:59:59.000Z

    The Lagrangian describing the bulk electromagnetic response of a three-dimensional strong topological insulator contains a topological ''axion'' term of the form {theta}E{center_dot}B. It is often stated (without proof) that the corresponding action is quantized on periodic space time and therefore invariant under {theta}{yields}{theta}+2{pi}. Here we provide a simple, physically motivated proof of the axion action quantization on the periodic space time, assuming only that the vector potential is consistent with single valuedness of the electron wave functions in the underlying insulator.

  9. Periodic striations on beryllium and tungsten surfaces by indirect femtosecond laser irradiation

    SciTech Connect (OSTI)

    Lungu, C. P.; Tico?, C. M., E-mail: catalin.ticos@inflpr.ro; Poro?nicu, C.; Jepu, I.; Lungu, M.; Marcu, A.; Luculescu, C.; Cojocaru, G.; Ursescu, D.; B?nici, R.; Ungureanu, G. R. [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania)] [National Institute for Laser, Plasma and Radiation Physics, 077125 Bucharest (Romania)

    2014-03-10T23:59:59.000Z

    Femtosecond laser pulses with ??=?800?nm were focused in air at one atmosphere and in deuterium (D) at low pressure. Submicron periodic structures were observed on surfaces made of Be, W and a mixture of Be-W immersed in these gases and placed nearly parallel with the laser beam, at 300??m from the focal spot. In air, no structures were observed on Be. For the Be-W mixture, the periodic structures were uniform and parallel when formed in D but irregular in air. In this last case the striations were organized into small patches of 1 to 2 ?m in size.

  10. Grain sorghum response to different flooding periods at the early boot stage

    E-Print Network [OSTI]

    Zolezzi del Rio, Oscar

    2012-06-07T23:59:59.000Z

    GRAIN SORGHUM RESPONSE TO DIFFERENT FLOODING PERIODS AT THE EARLY BOOT STAGE A Thesis by OSCAR ZOLEZZI DEL RIO Submitted to the Graduate College of Texas A)M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1976 Major Subject: Agricultural Engineering GRAIN SORGHUM RESPONSE TO DIFFERENT FLOODING PERIODS AT THE EARLY BOOT STAGE A Thesis by OSCAR 2OLE22I DEL RIO Approved as to style and content by: airman o ommzttee Hea o Departme t e er...

  11. Getting More For Your Money: Identifying and Confirming Long-Period Planets with Kepler

    E-Print Network [OSTI]

    Jennifer C. Yee; B. Scott Gaudi

    2008-07-16T23:59:59.000Z

    Kepler will monitor enough stars that it is likely to detect single transits of planets with periods longer than the mission lifetime. We show that by combining the Kepler photometry of such transits with precise radial velocity (RV) observations taken over ~3 months, and assuming circular orbits, it is possible to estimate the periods of these transiting planets to better than 20% (for planets with radii greater than that of Neptune) and the masses to within a factor of 2 (for planet masses m_p > M_Jup). We also explore the effects of eccentricity on our estimates of these uncertainties.

  12. Diffusion-induced periodic transition between oscillatory modes in amplitude-modulated patterns

    SciTech Connect (OSTI)

    Tang, Xiaodong; He, Yuxiu; Wang, Shaorong; Gao, Qingyu, E-mail: gaoqy@cumt.edu.cn [College of Chemical Engineering, China University of Mining and Technology, Xuzhou 221008 (China)] [College of Chemical Engineering, China University of Mining and Technology, Xuzhou 221008 (China); Epstein, Irving R., E-mail: epstein@brandeis.edu [Department of Chemistry and Volen Center for Complex Systems, MS 015, Brandeis University, Waltham, Massachusetts 02454-9110 (United States); Wang, Qun [School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116 (China)] [School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116 (China)

    2014-06-15T23:59:59.000Z

    We study amplitude-modulated waves, e.g., wave packets in one dimension, overtarget spirals and superspirals in two dimensions, under mixed-mode oscillatory conditions in a three-variable reaction-diffusion model. New transition zones, not seen in the homogeneous system, are found, in which periodic transitions occur between local 1{sup N?1} and 1{sup N} oscillations. Amplitude-modulated complex patterns result from periodic transition between (N???1)-armed and N-armed waves. Spatial recurrence rates provide a useful guide to the stability of these modulated patterns.

  13. Orbital period derivative of a binary system using an exact orbital energy equation

    E-Print Network [OSTI]

    Vikram H. Zaveri

    2014-11-07T23:59:59.000Z

    It is proposed that the equations of motion in periodic relativity which yielded major predictions of general relativity without utilizing Riemannian geometry and geodesic trajectories are exact in nature and can be applied to pulsars and inspiraling compact binaries for analyzing orbital period derivative and two polarization gravitational wave forms. Exactness of these equations eliminates the need for higher order xPN corrections to the orbital energy part of the balance equation. This is mainly due to the introduction of dynamic WEP which states that the gravitational mass is equal to the relativistic mass.

  14. Pump-probe imaging of laser-induced periodic surface structures after ultrafast irradiation of Si

    SciTech Connect (OSTI)

    Murphy, Ryan D. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Adams, David P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2013-09-30T23:59:59.000Z

    Ultrafast pump-probe microscopy has been used to investigate laser-induced periodic surface structure (LIPSS) formation on polished Si surfaces. A crater forms on the surface after irradiation by a 150 fs laser pulse, and a second, subsequent pulse forms LIPSS within the crater. Sequentially delayed images show that LIPSS with a periodicity slightly less than the fundamental laser wavelength of 780 nm appear on Si surfaces ?50 ps after arrival of the second pump laser pulse, well after the onset of melting. LIPSS are observed on the same timescale as material removal, suggesting that their formation involves material ejection.

  15. Propagation of matter wave solitons in periodic and random nonlinear potentials

    E-Print Network [OSTI]

    Fatkhulla Kh. Abdullaev; Josselin Garnier

    2005-11-10T23:59:59.000Z

    We study the motion of bright matter wave solitons in nonlinear potentials, produced by periodic or random spatial variations of the atomic scattering length. We obtain analytical results for the soliton motion, the radiation of matter wave, and the radiative soliton decay in such configurations of the Bose-Einstein condensate. The stable regimes of propagation are analyzed. The results are in remarkable agreement with the numerical simulations of the Gross-Pitaevskii equation with periodic or random spatial variations of the mean field interactions.

  16. BoseEinstein condensates in spatially periodic potentials Kirstine BergSrensen 1 and Klaus Mlmer 2

    E-Print Network [OSTI]

    Berg-Sørensen, Kirstine

    Bose­Einstein condensates in spatially periodic potentials Kirstine Berg­Sørensen 1 and Klaus theoretically the properties of a Bose­Einstein condensate located in a spatially periodic potential. The excitations of the condensate are obtained from linear equations involving the periodic potential

  17. Periodic Broadcast and Patching Services -Implementation, Measurement, and Analysis in an Internet

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Periodic Broadcast and Patching Services - Implementation, Measurement, and Analysis in an Internet to multime- dia steams by a large number of clients. Current research in this area has focussed primarily these algorithms. We present measurements detailing the overheads associated with the various server compo- nents

  18. Periodic Broadcast and Patching Services Implementation, Measurement, and Analysis in an Internet

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Periodic Broadcast and Patching Services ­ Implementation, Measurement, and Analysis in an Internet time al- lowing asynchronous access to multimedia steams by a large number of clients. Current research, and explore the issues that arise when implementing these algorithms. We present measurements detailing

  19. TWO NEW LONG-PERIOD HOT SUBDWARF BINARIES WITH DWARF COMPANIONS

    SciTech Connect (OSTI)

    Barlow, Brad N.; Wade, Richard A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Liss, Sandra E. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Green, Elizabeth M., E-mail: bbarlow@psu.edu [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States)

    2013-07-01T23:59:59.000Z

    Hot subdwarf stars with F-K main sequence binary companions have been known for decades, but the first orbital periods for such systems were published just recently. Current observations suggest that most have long periods, on the order of years, and that some are or once were hierarchical triple systems. As part of a survey with the Hobby-Eberly Telescope, we have been monitoring the radial velocities of several composite-spectra binaries since 2005 in order to determine their periods, velocities, and eccentricities. Here we present observations and orbital solutions for two of these systems, PG 1449+653 and PG 1701+359. Similar to the other sdB+F/G/K binaries with solved orbits, their periods are long, 909 and 734 days, respectively, and pose a challenge to current binary population synthesis models of hot subdwarf stars. Intrigued by their relatively large systemic velocities, we also present a kinematical analysis of both targets and find that neither is likely a member of the Galactic thin disk.

  20. Reversible ratchets as Brownian particles in an adiabatically changing periodic potential Juan M. R. Parrondo

    E-Print Network [OSTI]

    Parrondo, Juan M.R.

    Reversible ratchets as Brownian particles in an adiabatically changing periodic potential Juan M. R of particles is induced without any energy consumption. These cycles can be called reversible ratchets called ratch- ets, since they are somehow inspired by the discussion in Ref. 16 of a ratchet working

  1. Chaotic Hamiltonian ratchets for pulsed periodic double-well potentials: Classical correlations and the ratchet current

    E-Print Network [OSTI]

    Jonckheere, Thibaut

    Chaotic Hamiltonian ratchets for pulsed periodic double-well potentials: Classical correlations and the ratchet current N. A. C. Hutchings,1 M. R. Isherwood,1 T. Jonckheere,2 and T. S. Monteiro1 1 Department, ratchet currents, and time scales of a new ratchet in a fully chaotic Hamiltonian system, introduced

  2. Ratchet Effects Induced by Terahertz Radiation in Heterostructures with a Lateral Periodic Potential

    E-Print Network [OSTI]

    Ganichev, Sergey

    Ratchet Effects Induced by Terahertz Radiation in Heterostructures with a Lateral Periodic of the Seebeck ratchet effect. The effect is measured in semiconductor heterostructures with a one ratchet effect, we observe a photon helicity dependent response and propose a microscopic mechanism

  3. Frictional powders: Ratcheting under periodic strain in 3D , C. T. David2

    E-Print Network [OSTI]

    Luding, Stefan

    Frictional powders: Ratcheting under periodic strain in 3D S. Luding1 , C. T. David2 , R. Garcia the (deviatoric) stress- strain relation a ratchet-like behavior is observed: Increasing the coefficient of friction leads to a transition from ratcheting to shake-down, i.e., the accumulation of strain stops

  4. LINEAR TIME PERIODIC MODELLING OF POWER ELECTRONIC DEVICES FOR POWER SYSTEM HARMONIC ANALYSIS AND SIMULATION

    E-Print Network [OSTI]

    Boyer, Edmond

    LINEAR TIME PERIODIC MODELLING OF POWER ELECTRONIC DEVICES FOR POWER SYSTEM HARMONIC ANALYSIS by simulation. 1. INTRODUCTION The variety and the wide spread use of power electronic devices in the power networks is due to their diverse and multiple functions: compensation, protection and interface

  5. INVESTIGATION OF PERIODIC BOUNDARY CONDITIONS IN MULTIPASSAGE CASCADE FLOWS USING OVERSET GRIDS

    E-Print Network [OSTI]

    Tuncer, Ismail H.

    . Computational results are presented for two and four passage, subsonic and tran­ sonic flows through a turbine and a compressor cascade. The overset grid solutions over the multi­passage periodic domains agree well in Refers to inflow exit Refers to outflow a Acoustic speed A Max. amplitude of the plunging motion c Blade

  6. Quarterly RCRA Groundwater Monitoring Data for the Period April Through June 2006

    SciTech Connect (OSTI)

    Hartman, Mary J.

    2006-11-01T23:59:59.000Z

    This report provides information about RCRA groundwater monitoring for the period April through June 2006. Seventeen RCRA sites were sampled during the reporting quarter. Sampled sites include seven monitored under groundwater indicator evaluation (''detection'') programs, eight monitored under groundwater quality assessment programs, and two monitored under final-status programs.

  7. Global Clock, Physical Time Order and Pending Period Analysis in Multiprocessor Systems

    E-Print Network [OSTI]

    Chen, Yunji; Hu, Weiwu

    2009-01-01T23:59:59.000Z

    In multiprocessor systems, various problems are treated with Lamport's logical clock and the resultant logical time orders between operations. However, one often needs to face the high complexities caused by the lack of logical time order information in practice. In this paper, we utilize the \\emph{global clock} to infuse the so-called \\emph{pending period} to each operation in a multiprocessor system, where the pending period is a time interval that contains the performed time of the operation. Further, we define the \\emph{physical time order} for any two operations with disjoint pending periods. The physical time order is obeyed by any real execution in multiprocessor systems due to that it is part of the truly happened operation orders restricted by global clock, and it is then proven to be independent and consistent with traditional logical time orders. The above novel yet fundamental concepts enables new effective approaches for analyzing multiprocessor systems, which are named \\emph{pending period analy...

  8. Dental analysis of Classic period population variability in the Maya area

    E-Print Network [OSTI]

    Scherer, Andrew Kenneth

    2005-02-17T23:59:59.000Z

    DENTAL ANALYSIS OF CLASSIC PERIOD POPULATION VARIABILITY IN THE MAYA AREA A Dissertation by ANDREW KENNETH SCHERER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... Morphology and Size......................................................50 Dental Anthropology and Human Population Variation...........................................57 Previous Studies of Ancient Mesoamerican Population...

  9. Sound transmission through a periodic cascade with application to drill pipes

    E-Print Network [OSTI]

    Rienstra, Sjoerd W.

    Sound transmission through a periodic cascade with application to drill pipes Niels J. C. Lous Acoustical data transmission through the wall of drill pipes is considered. Drill pipes are known to behave the frequency domain drill pipe models presented by Barnes and Kirkwood J. Acoust. Soc. Am. 51, 1606­1608 1972

  10. X-ray periodicities in sources observed by the RXTE ASM

    E-Print Network [OSTI]

    Shivamoggi, Vasudha B

    2005-01-01T23:59:59.000Z

    The X-ray intensities measured from 230 X-ray sources observed by the RXTE All-Sky Monitor (ASM) were analyzed for periodic behavior. The ASM has been observing sources for nine years in the 1.5-12 keV energy range. In ...

  11. Periodic orbit analysis of a system with continuous symmetry - a tutorial

    E-Print Network [OSTI]

    Nazmi Burak Budanur; Daniel Borrero-Echeverry; Predrag Cvitanovi?

    2015-02-06T23:59:59.000Z

    Dynamical systems with translational or rotational symmetry arise frequently in studies of spatially extended physical systems, such as Navier-Stokes flows on periodic domains. In these cases, it is natural to express the state of the fluid in terms of a Fourier series truncated to a finite number of modes. Here, we study a 4-dimensional two-mode SO(2)-equivariant model of this type, the smallest possible truncation that retains the symmetry but is high-dimensional enough to allow for chaotic dynamics. A crucial step in the analysis of such a system is symmetry reduction. We use the model to illustrate different symmetry-reduction techniques. Its relative equilibria are conveniently determined by rewriting the dynamics in terms of a symmetry-invariant polynomial basis. However, for the analysis of its chaotic dynamics, the `method of slices', which is applicable to very high-dimensional problems, is preferable. We show that a Poincar\\'e section taken on the `slice' can be used to further reduce this flow to what is for all practical purposes a unimodal map. This enables us to systematically determine all relative periodic orbits and their symbolic dynamics up to any desired period. We then present cycle averaging formulas adequate for systems with continuous symmetry and use them to compute dynamical averages using relative periodic orbits. The convergence of such computations is discussed.

  12. Is the apparent period-doubling in Blazhko stars actually an illusion?

    E-Print Network [OSTI]

    Bryant, Paul H

    2015-01-01T23:59:59.000Z

    It is known that the light curves of many Blazhko stars exhibit intervals in which successive pulsation maxima alternate between two levels in a way that is characteristic of period-doubling. In addition, hydrodynamical models of these stars have clearly demonstrated period-doubling bifurcations. As a result, it is now generally accepted that these stars do indeed exhibit period-doubling. Here we present strong evidence that this assumption is incorrect. The alternating peak heights likely result from the presence of one or more near-resonant modes which appear in the stellar spectra and are significantly offset from 3/2 times the fundamental frequency. A previous explanation for the presence of these peaks is shown to be inadequate. The phase-slip of the dominant near-resonant peak in RR Lyr is shown to be fully correlated with the parity of the observed alternations, providing further strong evidence that the process is nonresonant and cannot be characterized as period-doubling. The dominant near-resonant p...

  13. Post Common Envelope Binaries from SDSS - III. Seven new orbital periods

    E-Print Network [OSTI]

    Rebassa-Mansergas, A; Schreiber, M R; Southworth, J; Schwope, A D; Gomez-Moran, A Nebot; Aungwerojwit, A; Rodrguez-Gil, P; Karamanavis, V; Krumpe, M; Tremou, E; Schwarz, R; Staude, A; Vogel, J

    2008-01-01T23:59:59.000Z

    We present follow-up spectroscopy and photometry of 11 post common envelope binary (PCEB) candidates identified from multiple Sloan Digital Sky Survey (SDSS) spectroscopy in an earlier paper. Radial velocity measurements using the \\Lines{Na}{I}{8183.27,8194.81} absorption doublet were performed for nine of these systems and provided measurements of six orbital periods in the range $\\Porb= 2.7-17.4$ h. Three PCEB candidates did not show significant radial velocity variations in the follow-up data, and we discuss the implications for the use of SDSS spectroscopy alone to identify PCEBs. Differential photometry confirmed one of our spectroscopic orbital periods and provided one additional \\Porb measurement. Binary parameters are estimated for the seven objects for which we have measured the orbital period and the radial velocity amplitude of the low-mass companion star, $K_\\mathrm{sec}$. So far, we have published nine SDSS PCEBs orbital periods, all of them $\\Porb1$ day, and that during the common envelope phase...

  14. Post Common Envelope Binaries from SDSS - III. Seven new orbital periods

    E-Print Network [OSTI]

    A. Rebassa-Mansergas; B. T. Gaensicke; M. R. Schreiber; J. Southworth; A. D. Schwope; A. Nebot Gomez-Moran; A. Aungwerojwit; P. Rodriguez-Gil; V. Karamanavis; M. Krumpe; E. Tremou; R. Schwarz; A. Staude; J. Vogel

    2008-08-15T23:59:59.000Z

    We present follow-up spectroscopy and photometry of 11 post common envelope binary (PCEB) candidates identified from multiple Sloan Digital Sky Survey (SDSS) spectroscopy in an earlier paper. Radial velocity measurements using the \\Lines{Na}{I}{8183.27,8194.81} absorption doublet were performed for nine of these systems and provided measurements of six orbital periods in the range $\\Porb= 2.7-17.4$ h. Three PCEB candidates did not show significant radial velocity variations in the follow-up data, and we discuss the implications for the use of SDSS spectroscopy alone to identify PCEBs. Differential photometry confirmed one of our spectroscopic orbital periods and provided one additional \\Porb measurement. Binary parameters are estimated for the seven objects for which we have measured the orbital period and the radial velocity amplitude of the low-mass companion star, $K_\\mathrm{sec}$. So far, we have published nine SDSS PCEBs orbital periods, all of them $\\Porb1$ day, and that during the common envelope phase the orbital energy of the binary star is maybe less efficiently used to expell the envelope than frequently assumed.

  15. Differential and Integral Equations Volume...., Number....., pp. N-SPECIES COMPETITION IN A PERIODIC CHEMOSTAT

    E-Print Network [OSTI]

    Wolkowicz, Gail S. K.

    , the single-species growth model, has a threshold between global extinction and uniform persistenceDifferential and Integral Equations Volume...., Number....., pp. N-SPECIES COMPETITION is proved and then applied to models of single-species growth and n-species competition in a periodically

  16. Weekly Security Incident Log Period of May 14 -May 20, 2012

    E-Print Network [OSTI]

    Weekly Security Incident Log Period of May 14 - May 20, 2012 Incident No. Reported Date Building-000955 PARKING GARAGE - ARBORETUM LANE (PS2) Mech\\Electrical Security responded to a report that an automotive York Security responded to a report of an unknown male causing a disturbance in the food court

  17. Non-periodic finite-element formulation of KohnSham density functional theory

    E-Print Network [OSTI]

    Ortiz, Michael

    Non-periodic finite-element formulation of Kohn­Sham density functional theory Phanish-element formulation for Kohn­Sham density functional theory (KS-DFT). We transform the original variational problem, dislocations and crack tips using density functional theory (DFT) at reasonable computational cost by retaining

  18. Dietary modifications of lipid metabolism in canine plasma during gestation, lactation, and the neonatal period

    E-Print Network [OSTI]

    Wright, Angela Shanna

    2004-01-01T23:59:59.000Z

    /Lo), linseed oil (Hi/Lo), low (Lo/Mod) or high (Lo/Hi) menhaden fish oil. Plasma was collected on days 0, 3, 7, 14, 28, 42, and 56 of gestation, days 10 and 28 of lactation, and days 4, 10, 16, 28, 70, and 84 of the neonatal period. Electrophoresis was run...

  19. EXTENDING THE CONCEPTS OF RETURN PERIOD AND RETURN LEVEL TO A CHANGING CLIMATE

    E-Print Network [OSTI]

    Katz, Richard

    -Stationarity in Extremes (3) Risk Communication under Stationarity (4) Risk Communication under Climate Change (5;#12;(4) Risk Communication Under Climate Change · One Approach -- "Effective" return level Permit "return levelEXTENDING THE CONCEPTS OF RETURN PERIOD AND RETURN LEVEL TO A CHANGING CLIMATE Rick Katz Institute

  20. Nonlinear friction of a damped dimer sliding on a periodic substrate S. Gonalves,1,2,

    E-Print Network [OSTI]

    Kenkre, V.M.

    Nonlinear friction of a damped dimer sliding on a periodic substrate S. Gonçalves,1,2, * V. M, USA (Received 23 July 2004; published 12 November 2004) The nonlinear sliding friction of a dimer over that the friction force has an approximate v-3 depen- dence if the velocity is sufficiently large

  1. Attractiveness of periodic orbits in parametrically forced systems with time-increasing friction

    E-Print Network [OSTI]

    Bartuccelli, Michele

    Attractiveness of periodic orbits in parametrically forced systems with time- increasing friction with time-increasing friction Michele Bartuccelli,1,a) Jonathan Deane,1,b) and Guido Gentile2,c) 1 oscillator in the presence of friction, and study numerically how time-varying friction affects the dynamics

  2. Cornell-Bahir Dar University Master's Program Report for the period November 2007 to February 2011

    E-Print Network [OSTI]

    Walter, M.Todd

    1 Cornell-Bahir Dar University Master's Program Report for the period November 2007 to February 2011 The Cornell University/Bahir Dar University (CU/BDU) Master's of Professional Studies (MPS. In January 2010 another 14 students came to the Bahir Dar campus. This is the first graduate degree program

  3. What hides behind extended periods of youth unemployment in Bosnia and Herzegovina?

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    What hides behind extended periods of youth unemployment in Bosnia and Herzegovina? Evidence from This paper provides the first empirical analysis on youth unemployment duration in Bosnia and ongoing economic and political reforms, the old economic structure and patterns of em- ployment in Bosnia

  4. QUANTUM ENERGY EXPECTATION IN PERIODIC TIME-DEPENDENT HAMILTONIANS VIA GREEN

    E-Print Network [OSTI]

    QUANTUM ENERGY EXPECTATION IN PERIODIC TIME-DEPENDENT HAMILTONIANS VIA GREEN FUNCTIONS C´ESAR R. DE. Introduction 1 2. Average Energy and Green Functions 4 3. Applications 10 3.1. Time-Independent Hamiltonians 10(t). For each positive and discrete observable A (which we call a probe energy), we derive a formula

  5. Small angle neutron scattering on periodically deformed polymers A. R. Rennie

    E-Print Network [OSTI]

    Boyer, Edmond

    765 Small angle neutron scattering on periodically deformed polymers A. R. Rennie Institut für Phys-768 SEPTEMBRE 1984, 1. Introduction. Neutron scattering has proved a useful tool for the investigation of a wide time for a small angle neutron scattering spectrum is several minutes. Obser- vation on rapidly

  6. Ultrafast laser induced periodic sub-wavelength aluminum surface structures and nanoparticles in air and liquids

    SciTech Connect (OSTI)

    Kuladeep, Rajamudili; Dar, Mudasir H.; Rao, D. Narayana, E-mail: dnrsp@uohyd.ac.in, E-mail: dnr-laserlab@yahoo.com [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Deepak, K. L. N. [Department of Physics and Center for Research in Photonics, University of Ottawa, 150 Louis Pasteur, Ottawa K1N6N5, Ontario (Canada)

    2014-09-21T23:59:59.000Z

    In this communication, we demonstrate the generation of laser-induced periodic sub-wavelength surface structures (LIPSS) or ripples on a bulk aluminum (Al) and Al nanoparticles (NPs) by femtosecond (fs) laser direct writing technique. Laser irradiation was performed on Al surface at normal incidence in air and by immersing in ethanol (C{sub 2}H{sub 5}OH) and water (H{sub 2}O) using linearly polarized Ti:sapphire fs laser pulses of ?110 fs pulse duration and ?800?nm wavelength. Field emission scanning electron microscope is utilized for imaging surface morphology of laser written structures and it reveals that the spatial periodicity as well as the surface morphology of the LIPSS depends on the surrounding dielectric medium and also on the various laser irradiation parameters. The observed LIPSS have been classified as low spatial frequency LIPSS which are perpendicularly oriented to the laser polarization with a periodicity from 460 to 620?nm and high spatial frequency LIPSS which spectacles a periodicity less than 100?nm with the orientation parallel to the polarization of the incident laser beam. Fabricated colloidal solutions, which contain the Al NPs, were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). TEM results reveal the formation of internal cavities in Al NPs both in ethanol and water. Formation mechanism of LIPSS and cavities inside the nanoparticles are discussed in detail.

  7. Development/Plasticity/Repair A Refractory Period for Rejuvenating GABAergic Synaptic

    E-Print Network [OSTI]

    Gruner, Daniel S.

    Development/Plasticity/Repair A Refractory Period for Rejuvenating GABAergic Synaptic Transmission and Ocular Dominance Plasticity with Dark Exposure Shiyong Huang,1* Yu Gu,2* Elizabeth M. Quinlan,2 Dark exposure initiated in adulthood reactivates robust ocular dominance plasticity in the visual

  8. Advanced quadratures and periodic boundary conditions in parallel 3D S{sub n} transport

    SciTech Connect (OSTI)

    Manalo, K.; Yi, C.; Huang, M.; Sjoden, G. [Nuclear and Radiological Engineering Program, G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 770 State Street, Atlanta, GA 30332-0745 (United States)

    2013-07-01T23:59:59.000Z

    Significant updates in numerical quadratures have warranted investigation with 3D Sn discrete ordinates transport. We show new applications of quadrature departing from level symmetric (S{sub 2}o). investigating 3 recently developed quadratures: Even-Odd (EO), Linear-Discontinuous Finite Element - Surface Area (LDFE-SA), and the non-symmetric Icosahedral Quadrature (IC). We discuss implementation changes to 3D Sn codes (applied to Hybrid MOC-Sn TITAN and 3D parallel PENTRAN) that can be performed to accommodate Icosahedral Quadrature, as this quadrature is not 90-degree rotation invariant. In particular, as demonstrated using PENTRAN, the properties of Icosahedral Quadrature are suitable for trivial application using periodic BCs versus that of reflective BCs. In addition to implementing periodic BCs for 3D Sn PENTRAN, we implemented a technique termed 'angular re-sweep' which properly conditions periodic BCs for outer eigenvalue iterative loop convergence. As demonstrated by two simple transport problems (3-group fixed source and 3-group reflected/periodic eigenvalue pin cell), we remark that all of the quadratures we investigated are generally superior to level symmetric quadrature, with Icosahedral Quadrature performing the most efficiently for problems tested. (authors)

  9. Solid State Division progress report for period ending September 30, 1990

    SciTech Connect (OSTI)

    Green, P.H.; Hinton, L.W. (eds.)

    1991-03-01T23:59:59.000Z

    This report covers research progress in the Solid State Division from April 1, 1989, to September 30, 1990. During this period, division research programs were significantly enhanced by the restart of the High-Flux Isotope Reactor (HFIR) and by new initiatives in processing and characterization of materials.

  10. Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Real-time Scheduling of periodic tasks in a monoprocessor system with rechargeable energy storage-time computing system that is powered through a renewable energy storage device. In this context, two constraints for the properties of the energy source, capacity of the energy storage as well as energy consumption of the tasks

  11. Solid State Division progress report for period ending March 31, 1992

    SciTech Connect (OSTI)

    Green, P.H.; Hinton, L.W. [eds.

    1992-09-01T23:59:59.000Z

    During this period, the division conducted a broad, interdisciplinary materials research program with emphasis on theoretical solid state physics, superconductivity, neutron scattering, synthesis and characterization of materials, ion beam and laser processing, and the structure of solids and surfaces. The High Flux Isotope Reactor was returned to full operation.

  12. A MEDIEVAL WARM PERIOD l)13 C RECORD FROM THE GAURA CU MUSCA CAVE, SW ROMANIA

    E-Print Network [OSTI]

    Forray, Ferenc

    A MEDIEVAL WARM PERIOD l)13 C RECORD FROM THE GAURA CU MUSCA CAVE, SW ROMANIA Bogdan P. ONAC1 · 2, Romania (2) School of Geosciences, University of South Florida, 4202 E. Fowler Ave., NES 107, Tampa, FL and Romania. B. Geological map of the region {modified fromlancu et al., 1995). The mapof the Gaura cu Musca

  13. Proceedings Published 2007 by the American Chemical Society Double Direct Templating of Periodically

    E-Print Network [OSTI]

    Braun, Paul

    of Periodically Nanostructured Inorganic Hollow Microspheres Paul V. Braun, Alejandro Wolosiuk, Dongyeon Son, Dara, and Frederick Seitz Materials Research Laboratory, Urbana, IL 61801 INTRODUCTION Hollow capsules are both technologically and scientifically interesting. `Smart' nano and micro containers could lead to structures

  14. Double Direct Templating of Periodically Nanostructured ZnS Hollow Microspheres

    E-Print Network [OSTI]

    Braun, Paul

    Double Direct Templating of Periodically Nanostructured ZnS Hollow Microspheres Alejandro Wolosiuk 61801 Received July 22, 2005; E-mail: pbraun@uiuc.edu Hollow capsules are both technologically and scientifically interesting. "Smart" nano- and microcontainers could lead new catalysts, structures

  15. RESEARCH COUNCILS' INDIVIDUAL MERIT PROMOTION SCHEME INDIVIDUAL MERIT PROMOTION PERIODIC REVIEW

    E-Print Network [OSTI]

    Brierley, Andrew

    GUIDANCE NOTES Please read these guidance notes carefully before completing the form. You may also wish in the development and exploitation of technologies 6. Provide a CV that summarises your career to date; include that have had an impact on your career progression; for example, periods of maternity leave, part

  16. Periodicity detection and localization using spike timing from the AER EAR

    E-Print Network [OSTI]

    Liu, Shih-Chii

    Periodicity detection and localization using spike timing from the AER EAR Theodore Yu1 , Andrew Event Representation (AER) where each spike carries the identity of the sender. There are a handful of silicon cochleae with an Address Event type representation [4][5][6][7]. The AER EAR chip that we use

  17. Millihertz quasi-periodic oscillations and thermonuclear bursts from Terzan 5: A showcase of burning regimes

    E-Print Network [OSTI]

    Linares, M.

    We present a comprehensive study of the thermonuclear bursts and millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) transient and 11 Hz X-ray pulsar IGR J174802446, located in the globular cluster ...

  18. Industrial Revolutions and Consumption: A Common Model to the Various Periods of Industrialization

    E-Print Network [OSTI]

    Boyer, Edmond

    Industrial Revolutions and Consumption: A Common Model to the Various Periods of Industrialization and establish a plausible link between consumption structure evolutions and industrial revolutions. In particular, we show that an industrial revolution starts with a "smithian growth process", which is demand

  19. Transiting Planets with LSST II. Period Detection of Planets Orbiting 1 Solar Mass Hosts

    E-Print Network [OSTI]

    Jacklin, Savannah R; Pepper, Joshua; Stassun, Keivan G

    2015-01-01T23:59:59.000Z

    The Large Synoptic Survey Telescope (LSST) will photometrically monitor ~1 billion stars for ten years. The resulting light curves can be used to detect transiting exoplanets. In particular, as demonstrated by Lund et al. (2015), LSST will probe stellar populations currently undersampled in most exoplanet transit surveys, including out to extragalactic distances. In this paper we test the efficiency of the box-fitting least-squares (BLS) algorithm for accurately recovering the periods of transiting exoplanets using simulated LSST data. We model planets with a range of radii orbiting a solar-mass star at a distance of 7 kpc, with orbital periods ranging from 0.5 to 20 d. We find that typical LSST observations will be able to reliably detect Hot Jupiters with periods shorter than ~3 d. At the same time, we find that the LSST deep drilling cadence is extremely powerful: the BLS algorithm successfully recovers at least 30% of sub-Saturn-size exoplanets with orbital periods as long as 20 d.

  20. Recent advances about the uniqueness of the slowly oscillating periodic solutions of Wright's equation

    E-Print Network [OSTI]

    Lessard, Jean-Philippe

    Recent advances about the uniqueness of the slowly oscillating periodic solutions of Wright's equation Jean-Philippe Lessard Abstract An old conjecture in delay equations states that Wright's equation to rigorously compute a global continuous branch of SOPS of Wright's equation. Using this method, we show

  1. Hamiltonian description of self-consistent wave-particle dynamics in a periodic Frederic Andre,1,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of the electron, self-acceleration and acausality, also appear incompatible with the existence of a wellHamiltonian description of self-consistent wave-particle dynamics in a periodic structure Fr conserves energy and excludes self-acceleration. A complete Hamiltonian formulation results from adding

  2. Periodically Controlled Hybrid Systems Verifying A Controller for An Autonomous Vehicle

    E-Print Network [OSTI]

    Murray, Richard M.

    Periodically Controlled Hybrid Systems Verifying A Controller for An Autonomous Vehicle Tichakorn Hybrid Au- tomata (PCHA) for describing a class of hybrid control systems. In a PCHA, control actions of the planner-controller subsystem of an autonomous ground vehicle, and in deriving geometric properties

  3. GENERATION OF QUASI-PERIODIC WAVES AND FLOWS IN THE SOLAR ATMOSPHERE BY OSCILLATORY RECONNECTION

    SciTech Connect (OSTI)

    McLaughlin, J. A.; Verth, G. [School of Computing, Engineering and Information Sciences, Northumbria University, Newcastle Upon Tyne, NE1 8ST (United Kingdom); Fedun, V.; Erdelyi, R., E-mail: james.a.mclaughlin@northumbria.ac.uk, E-mail: gary.verth@northumbria.ac.uk, E-mail: v.fedun@sheffield.ac.uk, E-mail: robertus@sheffield.ac.uk [Solar Physics and Space Plasma Research Centre (SP2RC), School of Mathematics and Statistics, University of Sheffield, Hounsfield Road, Hicks Building, Sheffield, S3 7RH (United Kingdom)

    2012-04-10T23:59:59.000Z

    We investigate the long-term evolution of an initially buoyant magnetic flux tube emerging into a gravitationally stratified coronal hole environment and report on the resulting oscillations and outflows. We perform 2.5-dimensional nonlinear numerical simulations, generalizing the models of McLaughlin et al. and Murray et al. We find that the physical mechanism of oscillatory reconnection naturally generates quasi-periodic vertical outflows, with a transverse/swaying aspect. The vertical outflows consist of both a periodic aspect and evidence of a positively directed flow. The speed of the vertical outflow (20-60 km s{sup -1}) is comparable to those reported in the observational literature. We also perform a parametric study varying the magnetic strength of the buoyant flux tube and find a range of associated periodicities: 1.75-3.5 minutes. Thus, the mechanism of oscillatory reconnection may provide a physical explanation to some of the high-speed, quasi-periodic, transverse outflows/jets recently reported by a multitude of authors and instruments.

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

    E-Print Network [OSTI]

    Barsotti, Lisa

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

  5. All-sky search for periodic gravitational waves in the full S5 LIGO data

    E-Print Network [OSTI]

    Barsotti, Lisa

    We report on an all-sky search for periodic gravitational waves in the frequency band 50800 Hz and with the frequency time derivative in the range of 0 through -610[superscript -9]??Hz/s. Such a signal could be produced ...

  6. SEARCHES FOR PERIODIC NEUTRINO EMISSION FROM BINARY SYSTEMS WITH 22 AND 40 STRINGS OF ICECUBE

    SciTech Connect (OSTI)

    Abbasi, R.; Aguilar, J. A.; Andeen, K.; Baker, M. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Abdou, Y. [Department of Physics and Astronomy, University of Gent, B-9000 Gent (Belgium); Abu-Zayyad, T. [Department of Physics, University of Wisconsin, River Falls, WI 54022 (United States); Ackermann, M.; Bazo Alba, J. L. [DESY, D-15735 Zeuthen (Germany); Adams, J. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Ahlers, M. [Department of Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Allen, M. M. [Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Altmann, D. [III. Physikalisches Institut, RWTH Aachen University, D-52056 Aachen (Germany); Auffenberg, J. [Department of Physics, University of Wuppertal, D-42119 Wuppertal (Germany); Bai, X. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Barwick, S. W. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Bay, R. [Department of Physics, University of California, Berkeley, CA 94720 (United States); Beattie, K. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Beatty, J. J. [Department of Physics and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Bechet, S. [Universite Libre de Bruxelles, Science Faculty CP230, B-1050 Brussels (Belgium); Becker, J. K. [Fakultaet fuer Physik and Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Collaboration: IceCube Collaboration; and others

    2012-04-01T23:59:59.000Z

    In this paper, we present the results of searches for periodic neutrino emission from a catalog of binary systems. Such modulation, observed in the photon flux, would be caused by the geometry of these systems. In the analysis, the period is fixed by these photon observations, while the phase and duration of the neutrino emission are treated as free parameters to be fit with the data. If the emission occurs during {approx}20% or less of the total period, this analysis achieves better sensitivity than a time-integrated analysis. We use the IceCube data taken from 2007 May 31 to 2008 April 5 with its 22 string configuration and from 2008 April 5 to 2009 May 20 with its 40 string configuration. No evidence for neutrino emission is found, with the strongest excess occurring for Cygnus X-3 at 2.1{sigma} significance after accounting for trials. Neutrino flux upper limits for both periodic and time-integrated emission are provided.

  7. Devil's Staircase in the Magnetoresistance of a Periodic Array of Scatterers

    SciTech Connect (OSTI)

    Wiersig, Jan; Ahn, Kang-Hun

    2001-07-09T23:59:59.000Z

    The nonlinear response to an external electric field is studied for classical noninteracting charged particles under the influence of a uniform magnetic field, a periodic potential, and an effective friction force. We find numerical and analytical evidence that the ratio of transverse to longitudinal resistance forms a Devil's staircase. The staircase is attributed to the dynamical phenomenon of mode-locking.

  8. Periodic Finite-Type Shift Spaces Marie-Pierre Beal, Member, IEEE, Maxime Crochemore, Member, IEEE,

    E-Print Network [OSTI]

    Siegel, Paul H.

    Periodic Finite-Type Shift Spaces Marie-Pierre B´eal, Member, IEEE, Maxime Crochemore, Member, IEEE are the c-charge con- strained codes over the bipolar alphabet {±1}. Here, the code M.-P. B´eal and M-mail: {beal,mac}@univ- mlv.fr). B. E. Moision was with the Mathematical Sciences Research Center, Lucent

  9. The discovery of plutonium reorganized the periodic table and aided the discovery of new elements

    SciTech Connect (OSTI)

    Clark, David L [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    The modern Periodic Table derives principally from the work of the great Russian scientist Dimitri Mendeleev, who in 1869 enunciated a 'periodic law' that the properties of the elements are a periodic function of their atomic weights, and arranged the 65 known elements in a 'periodic table'. Fundamentally, every column in the main body of the Periodic Table is a grouping of elements that display similar chemical and physical behavior. Similar properties are therefore exhibited by elements with widely different mass. Chemical periodicity is central to the study of chemistry, and no other generalization comes close to its ability to systematize and rationalize known chemical facts. With the development of atomic theory, and an understanding of the electronic structure of atoms, chemical periodicity and the periodic table now find their natural explanation in the electronic structure of atoms. Moving from left to right along any row, the elements are arranged sequentially according to nuclear charge (the atomic number). Electrons counter balance that nuclear charge, hence each successive element has one more electron in its configuration. The electron configuration, or distribution of electrons among atomic orbitals, may be determined by application of the Pauli principle (paired spin in the same orbital) and the aufbau principle (which outlines the order of filling of electrons into shells of orbitals - s, p, d, f, etc.) such that in a given atom, no two electrons may have all four quantum numbers identical. In 1939, only three elements were known to be heavier than actinium: thorium, protactinium, and uranium. All three exhibited variable oxidation states and a complex chemistry. Thorium, protactinium and uranium were assumed to be d-transition metals and were placed in the Periodic Table under hafnium, tantalum, and tungsten, respectively. By 1940, McMillan and Abelson bombarded uranium atoms with slow neutrons and successfully identified atoms of element 93, which they named neptunium after the planet Neptune. This rapidly set the stage for the discovery of the next succeeding element, plutonium (Seaborg, McMillan, Kennedy, and Wahl, 1940), named after the next planet away from the Sun, Pluto. The newly discovered elements were presumed to fit comfortably in the Periodic Table under rhenium and osmium, respectively. However, subsequent tracer chemical experiments showed that neptunium and plutonium were closer in their chemical properties to uranium than their presumed homologues, rhenium and osmium. Spectroscopic evidence also indicated that the new elements were not typical transition elements, but had f-electrons in their valence shell. Thus, several researchers, including McMillan and Wahl, and Zachariasen at Los Alamos, suggested that these elements might be part of a second inner-transition series in which the 5f-electron subshell was being filled. It was not clear, however, where the new series would begin. McMillian had proposed a 'uraninide series' that started with neptunium, but attempts to isolate elements with atomic numbers 95 and 96 based on assumed similarities to uranium were unsuccessful. Both Wahl and Zacharias en had proposed a thoride series that started with protactinium. In 1944, Seaborg proposed that the series started with thorium, and that all of the elements heavier than actinium constituted an 'actinide' series similar to the lanthanides. Because the 5f-shell began filling in the same relative position as the 4f-shell, the electronic configuration of elements in the two series would be similar. Guided by the hypothesis that elements 95 and 96 were homologues of europium and gadolinium, new experiments were designed and the elements were uniquely synthesized and separated from all others. The new elements were subsequently named americium and curium. Seaborg's 'Actinide Concept' thus played a major role in the discovery of the transplutonium elements. It provided the framework that supported synthesis, isolation, and identification of the succeeding actinide elements berkelium through lawrenci

  10. The BVRI Light Curves And Period Analysis Of The Beta Lyrae System XX Leonis

    E-Print Network [OSTI]

    P. Zasche; M. Wolf; P. Svoboda

    2007-11-19T23:59:59.000Z

    The contact eclipsing binary system XX Leonis (P = 0.97 days, sp A8) has been analysed using the PHOEBE programme, based on the Wilson Devinney code. The BVRI light curves were obtained during spring 2006 using the 20-cm telescope and ST-7 CCD detector. The effective temperature of the primary component determined from the photometric analysis is T=(7889+/-61)K, the inclination of the orbit is i=(89.98+/-2.45)deg and the photometric mass ratio q=(0.41+/-0.01). Also the third body hypothesis was suggested, based on the period analysis using 57 minimum times and resulting the period of the third body p3= (52.96+/-0.01)yr, amplitude A=(0.057+/-0.029)d and eccentricity e=(0.79+/-0.08) which gives the minimum mass m3,min=(3.6+/-0.8)M_sun.

  11. Periodic Optical Outbursts from the Be/Neutron Star Binary AX J0049.4-7323

    E-Print Network [OSTI]

    A. P. Cowley; P. C. Schmidtke

    2003-11-17T23:59:59.000Z

    The optical light curve of the Be/neutron star binary AX J0049.4-7323 has been investigated using data from the MACHO and OGLE-II projects. This X-ray source, whose neutron star has a very slow rotation rate (P_pulse=755.5 sec), shows optical outbursts every 394 days. The regularity of these outbursts suggests that their recurrence time is the orbital period of the system. During the outbursts the system brightens and becomes slightly redder. A possible interpretation is that a portion of the equatorial disk is excited as the neutron star passes through it during periastron passage. In the intervals between outbursts the light curve shows 11-day quasi-periodic varability which may be associated with the rotation of the Be star's extended disk.

  12. Hydraulic Characteristics of the Lower Snake River During Periods of Juvenile Fall Chinook Migration

    SciTech Connect (OSTI)

    Cook, Chris B.; Dibrani, Berhon; Richmond, Marshall C.; Bleich, Matthew D.; Titzler, P. Scott; Fu, Tao

    2006-01-30T23:59:59.000Z

    This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoirs epilimnion at the Clearwater/Snake River confluence is of key biological importance to juvenile fall Chinook salmon. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four lower Snake reservoirs are also heavily influenced by wind forcing at the waters surface, and during periods of low river discharge, often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The depth of this upper warm layer and its direction of travel may also be of key biological importance to juvenile fall Chinook salmon. This report describes field data collection, modeling, and analysis of hydrodynamic and temperature conditions in the Lower Granite Reservoir during the summer flow augmentation periods of 2002, 2003, and 2004 plus a brief one-week period in 2005 of Lower Monumental, Little Goose, and Lower Granite Reservoirs. Circulation patterns in all four lower Snake River reservoirs were numerically simulated for periods of 2002, 2003, 2004, and 2005 using CE-QUAL-W2. Simulation results show that these models are sufficiently capable of matching diurnal and long term temperature and velocity changes in the reservoirs. In addition, the confluence zone of the Clearwater and Snake rivers was modeled using the 3-D model Flow3-D. This model was used to better understand mixing processing and entrainment. Once calibrated and validated, the reservoir models were used to investigate downstream impacts of alternative reservoir operation schemes, such as increasing or decreasing the ratio of Clearwater to Snake discharge. Simulation results were also linked with the particle tracking model FINS to better understand alterations of integrated metrics due to alternative operation schemes. These findings indicate that significant alterations in water temperature throughout the lower Snake River are possible by altering hypolimnetic discharges from Dworshak Reservoir and may have a significant impact on the behavior of migrating juvenile fall Chinook salmon during periods of flow augmentation.

  13. Geometrical investigation of the kinetic evolution of the magnetic field in a periodic flux rope

    SciTech Connect (OSTI)

    Restante, A. L.; Lapenta, G. [Afdeling Plasma-astrofysica, Departement Wiskunde, KULeuven, University of Leuven, Leuven (Belgium)] [Afdeling Plasma-astrofysica, Departement Wiskunde, KULeuven, University of Leuven, Leuven (Belgium); Markidis, S. [High Performance Computing and Visualization (HPCViz) Department, KTH Royal Institute of Technology, Stockholm (Sweden)] [High Performance Computing and Visualization (HPCViz) Department, KTH Royal Institute of Technology, Stockholm (Sweden); Intrator, T. [Los Alamos National Laboratory, M.S. E526, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, M.S. E526, Los Alamos, New Mexico 87545 (United States)

    2013-08-15T23:59:59.000Z

    Flux ropes are bundles of magnetic field wrapped around an axis. Many laboratory, space, and astrophysics processes can be represented using this idealized concept. Here, a massively parallel 3D kinetic simulation of a periodic flux rope undergoing the kink instability is studied. The focus is on the topology of the magnetic field and its geometric structures. The analysis considers various techniques such as Poincar maps and the quasi-separatrix layer (QSL). These are used to highlight regions with expansion or compression and changes in the connectivity of magnetic field lines and consequently to outline regions where heating and current may be generated due to magnetic reconnection. The present study is, to our knowledge, the first QSL analysis of a fully kinetic 3D particle in cell simulation and focuses the existing QSL method of analysis to periodic systems.

  14. Polarization dependent formation of femtosecond laser-induced periodic surface structures near stepped features

    SciTech Connect (OSTI)

    Murphy, Ryan D. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Adams, David P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-06-09T23:59:59.000Z

    Laser-induced periodic surface structures (LIPSS) are formed near 110?nm-tall Au microstructured edges on Si substrates after single-pulse femtosecond irradiation with a 150 fs pulse centered near a 780 nm wavelength. We investigate the contributions of Fresnel diffraction from step-edges and surface plasmon polariton (SPP) excitation to LIPSS formation on Au and Si surfaces. For certain laser polarization vector orientations, LIPSS formation is dominated by SPP excitation; however, when SPP excitation is minimized, Fresnel diffraction dominates. The LIPSS orientation and period distributions are shown to depend on which mechanism is activated. These results support previous observations of the laser polarization vector influencing LIPSS formation on bulk surfaces.

  15. Analytical formulation of 3D dynamic homogenization for periodic elastic systems

    E-Print Network [OSTI]

    A. N. Norris; A. L. Shuvalov; A. A. Kutsenko

    2012-01-13T23:59:59.000Z

    Homogenization of the equations of motion for a three dimensional periodic elastic system is considered. Expressions are obtained for the fully dynamic effective material parameters governing the spatially averaged fields by using the plane wave expansion (PWE) method. The effective equations are of Willis form (Willis 1997) with coupling between momentum and stress and tensorial inertia. The formulation demonstrates that the Willis equations of elastodynamics are closed under homogenization. The effective material parameters are obtained for arbitrary frequency and wavenumber combinations, including but not restricted to Bloch wave branches for wave propagation in the periodic medium. Numerical examples for a 1D system illustrate the frequency dependence of the parameters on Bloch wave branches and provide a comparison with an alternative dynamic effective medium theory (Shuvalov 2011) which also reduces to Willis form but with different effective moduli.

  16. Entangled three-particle states in magnetic field: Periodic correlations and density matrices

    E-Print Network [OSTI]

    Amitabha Chakrabarti; Anirban Chakraborti

    2010-04-28T23:59:59.000Z

    We present a novel study of the time evolutions of entangled states of three spin-1/2 particles in the presence of a constant external magnetic field, which causes the individual spins to precess and leads to remarkable periodicities in the correlations and density matrices. The emerging patterns of periodicity are studied explicitly for different entangled states and in detail for a particular initial configuration of the velocities. Contributions to precession of anomalous magnetic moments are analysed and general results are also obtained. We then introduce an electric field orthogonal to the magnetic field, linking to the preceding case via a suitable Lorentz transformation, and obtain the corresponding Wigner rotations of the spin states. Finally, we point out for the first time that the entangled states corresponding to well-known ones in the study of 3-particle entanglements, may be classified systematically using a particular coupling of three angular momenta.

  17. Tracking multiple generation and suppression of secondary electrons on periodic triangular surface

    SciTech Connect (OSTI)

    Li, S.; Wang, J. G.; Zhu, M.; Peng, J. C.; Xie, J. L.; Wu, X. L.; Guo, L. T. [Laboratory on Science and Technology of High Power Microwave, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China)] [Laboratory on Science and Technology of High Power Microwave, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China); Chang, C.; Xiong, Z. F. [Laboratory on Science and Technology of High Power Microwave, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China) [Laboratory on Science and Technology of High Power Microwave, Northwest Institute of Nuclear Technology, Xi'an, Shaanxi 710024 (China); Department of Engineering Physics, Tsinghua University, Beijing 10084 (China)

    2013-12-15T23:59:59.000Z

    To research the dynamic course of multipactor suppression on the periodically patterned surface, tens of electron collision processes are tracked by numerical calculation. The influences of microwave frequency, amplitude of RF electric field, slope angle, the local field enhancement, and the tilted incident electric field on the multipactor suppression are studied by tracking multi-generation electrons' trajectories, hopping and flight time, collision energy, and secondary emission yield. Meanwhile, the dynamic processes of secondary electrons on the periodic surface are analyzed by particle-in-cell (PIC) simulation. The PIC results are consistent with the analytical results in which the electrons fly reciprocatingly between the slopes and impact on the slopes; the methods of increasing the slope angle, enlarging the RF field, and lowering the frequency in a certain range are helpful to enhance the multipactor suppression steadily and persistently.

  18. Eigenfunctions of Unbounded Support for Embedded Eigenvalues of Locally Perturbed Periodic Graph Operators

    E-Print Network [OSTI]

    Stephen P. Shipman

    2014-04-24T23:59:59.000Z

    It is known that, if a locally perturbed periodic self-adjoint operator on a combinatorial or quantum graph admits an eigenvalue embedded in the continuous spectrum, then the associated eigenfunction is compactly supported--that is, if the Fermi surface is irreducible, which occurs generically in dimension two or higher. This article constructs a class of operators whose Fermi surface is reducible for all energies by coupling several periodic systems. The components of the Fermi surface correspond to decoupled spaces of hybrid states, and in certain frequency bands, some components contribute oscillatory hybrid states (corresponding to spectrum) and other components contribute only exponential ones. This separation allows a localized defect to suppress the oscillatory (radiation) modes and retain the evanescent ones, thereby leading to embedded eigenvalues whose associated eigenfunctions decay exponentially but are not compactly supported.

  19. Glann Seaborg's Contributions to Heavy Element Science and the Periodic Table

    SciTech Connect (OSTI)

    Hobart, David E. [Los Alamos National Laboratory

    2012-08-17T23:59:59.000Z

    In celebrating the centennial anniversary of the birth of Glenn T. Seaborg it is fitting that we recount and pay tribute to his legacy. Many know of the scientific accomplishments of this man who became a legend and anyone who has attended his lectures can attest to how informative, educational, and entertaining he was. He had a beguiling and whimsical sense of humor and used this to drive home his points and share his passion and quest for discovery. The periodic table is a fundamental cornerstone of science and remains a central unifying principal. Seaborg was the architect of the actinide series of elements and their proper placement in the periodic table and co-discoverer of ten transuranium elements - one of which bears his name, element 106, seaborgium. The work and achievements of this Nobel laureate have touched the lives of many and his legacy will continue for generations to come.

  20. Exploration of period-doubling cascade route to chaos with complex network based time series construction

    E-Print Network [OSTI]

    Ruoxi Xiang; Michael Small

    2014-06-18T23:59:59.000Z

    In this work, the topologies of networks constructed from time series from an underlying system undergo a period doubling cascade have been explored by means of the prevalence of different motifs using an efficient computational motif detection algorithm. By doing this we adopt a refinement based on the $k$ nearest neighbor recurrence-based network has been proposed. We demonstrate that the refinement of network construction together with the study of prevalence of different motifs allows a full explosion of the evolving period doubling cascade route to chaos in both discrete and continuous dynamical systems. Further, this links the phase space time series topologies to the corresponding network topologies, and thus helps to understand the empirical "superfamily" phenomenon, as shown by Xu.

  1. The Long Period AM Her-like Cataclysmic Variable RXJ051541+0104.6

    E-Print Network [OSTI]

    F. M. Walter; S. J. Wolk; N. R. Adams

    1994-08-29T23:59:59.000Z

    We report the discovery of a new catacysmic variable system, RXJ051541+0104.6. The optical spectrum has a blue continuum with superposed H~I and He~I and II emission lines. The soft X-ray spectrum is well fit with a 50~eV black body. The X-ray and optical data are suggestive of an AM~Herculis system. The X-ray light curve shows extreme variability on timescales of seconds, and suggests an orbital period of order 8~hours, nearly twice that of the longest catalogued AM~Her period. When bright, the X-ray light curve breaks up into a series of discrete bursts, which may be due to accretion of dense blobs of material of about 10$^{17}$~gm mass.

  2. Van der Waals forces from first principles for periodic systems: Application to graphene-water interactions

    E-Print Network [OSTI]

    Pouya Partovi-Azar; T. D. Khne

    2015-04-17T23:59:59.000Z

    We extend the method of Silvestrelli [P. L. Silvestrelli, J. Chem. Phys. 139, 054106 (2013)] to approximate long-range van der Waals interactions at the density functional theory level based on maximally localized Wannier functions combined with the quantum harmonic oscillator model, to periodic systems. Applying this scheme to study London dispersion forces between graphene and water layers, we demonstrate that collective many-body effects beyond simple additive pair-wise interactions are essential to accurately describe van der Waals forces.

  3. Van der Waals forces from first principles for periodic systems: Application to graphene-water interactions

    E-Print Network [OSTI]

    Partovi-Azar, Pouya

    2015-01-01T23:59:59.000Z

    We extend the method of Silvestrelli [P. L. Silvestrelli, J. Chem. Phys. 139, 054106 (2013)] to approximate long-range van der Waals interactions at the density functional theory level based on maximally localized Wannier functions combined with the quantum harmonic oscillator model, to periodic systems. Applying this scheme to study London dispersion forces between graphene and water layers, we demonstrate that collective many-body effects beyond simple additive pair-wise interactions are essential to accurately describe van der Waals forces.

  4. Green's function asymptotics near the internal edges of spectra of periodic elliptic operators. Spectral edge case

    E-Print Network [OSTI]

    Peter Kuchment; Andrew Raich

    2011-10-02T23:59:59.000Z

    Precise asymptotics known for the Green's function of the Laplace operator have found their analogs for periodic elliptic operators of the second order at and below the bottom of the spectrum. Due to the band-gap structure of the spectra of such operators, the question arises whether similar results can be obtained near or at the edges of spectral gaps. As the result of this work shows, this is possible at a spectral edge in dimensions d>2.

  5. THE VERY SHORT PERIOD M DWARF BINARY SDSS J001641-000925

    SciTech Connect (OSTI)

    Davenport, James R. A.; Becker, Andrew C.; Hawley, Suzanne L.; Gunning, Heather C.; Munshi, Ferah A.; Albright, Meagan [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States)] [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); West, Andrew A. [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)] [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Bochanski, John J. [Astronomy and Astrophysics Department, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)] [Astronomy and Astrophysics Department, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Holtzman, Jon [Department of Astronomy, New Mexico State University, Box 30001, Las Cruces, NM 88003 (United States)] [Department of Astronomy, New Mexico State University, Box 30001, Las Cruces, NM 88003 (United States); Hilton, Eric J., E-mail: jrad@astro.washington.edu [Department of Geology and Geophysics and Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2013-02-10T23:59:59.000Z

    We present follow-up observations and analysis of the recently discovered short period low-mass eclipsing binary, SDSS J001641-000925. With an orbital period of 0.19856 days, this system has one of the shortest known periods for an M dwarf binary system. Medium-resolution spectroscopy and multi-band photometry for the system are presented. Markov Chain Monte Carlo modeling of the light curves and radial velocities yields estimated masses for the stars of M {sub 1} = 0.54 {+-} 0.07 M {sub Sun} and M {sub 2} = 0.34 {+-} 0.04 M {sub Sun }, and radii of R {sub 1} = 0.68 {+-} 0.03 R {sub Sun} and R {sub 2} = 0.58 {+-} 0.03 R {sub Sun }, respectively. This solution places both components above the critical Roche overfill limit, providing strong evidence that SDSS J001641-000925 is the first verified M-dwarf contact binary system. Within the follow-up spectroscopy we find signatures of non-solid body rotation velocities, which we interpret as evidence for mass transfer or loss within the system. In addition, our photometry samples the system over nine years, and we find strong evidence for period decay at the rate of P-dot {approx} 8 s yr{sup -1}. Both of these signatures raise the intriguing possibility that the system is in over-contact, and actively losing angular momentum, likely through mass loss. This places SDSS J001641-000925 as not just the first M-dwarf over-contact binary, but one of the few systems of any spectral type known to be actively undergoing coalescence. Further study of SDSS J001641-000925 is ongoing to verify the nature of the system, which may prove to be a unique astrophysical laboratory.

  6. Climatic variability at ten long period stations in the coterminous United States

    E-Print Network [OSTI]

    Vining, Kevin C.

    1982-01-01T23:59:59.000Z

    ) of the mean annual and season-year maxima and min1ma decadal variances indicate the strength of the trend 11nes. A modified Student's t-test (Brooks and Carruthers, 1953) was used comparing the regression co- efficients and correlation coefficients to the1r...). . . . . . . . . . . . . . . . . . . . . 63 The number of H, M, and L pentadal variances of isomeric coefficients occurring in fourteen five-year periods . . . 64 Correlation matrix: mean annual maximum temperatures. . . 74 Correlation matrix: mean annual minimum temperatures. . . 76...

  7. Homogenization of a catalyst layer model for periodically distributed pore geometries in PEM fuel cells

    E-Print Network [OSTI]

    Schmuck, Markus

    2012-01-01T23:59:59.000Z

    We formally derive an effective catalyst layer model comprising the reduction of oxygen for periodically distributed pore geometries. By assumption, the pores are completely filled with water and the surrounding walls consist of catalyst particles which are attached to an electron conducting microstructure. The macroscopic transport equations are established by a multi-scale approach, based on microscopic phenomena at the pore level, and serve as a first step toward future optimization of catalyst layer designs.

  8. Homogenization of a catalyst layer model for periodically distributed pore geometries in PEM fuel cells

    E-Print Network [OSTI]

    Markus Schmuck; Peter Berg

    2012-04-30T23:59:59.000Z

    We formally derive an effective catalyst layer model comprising the reduction of oxygen for periodically distributed pore geometries. By assumption, the pores are completely filled with water and the surrounding walls consist of catalyst particles which are attached to an electron conducting microstructure. The macroscopic transport equations are established by a multi-scale approach, based on microscopic phenomena at the pore level, and serve as a first step toward future optimization of catalyst layer designs.

  9. Quantum Energy Expectation in Periodic Time-Dependent hamiltonians via Green Functions

    E-Print Network [OSTI]

    Cesar R. de Oliveira; Mariza S. Simsen

    2009-07-31T23:59:59.000Z

    Let $U_F$ be the Floquet operator of a time periodic hamiltonian $H(t)$. For each positive and discrete observable $A$ (which we call a {\\em probe energy}), we derive a formula for the Laplace time average of its expectation value up to time $T$ in terms of its eigenvalues and Green functions at the circle of radius $e^{1/T}$. Some simple applications are provided which support its usefulness.

  10. Trends in Aqueous Hydration Across the 4f Period Assessed by Reliable Computational Methods

    SciTech Connect (OSTI)

    Kuta, Jadwiga; Clark, Aurora E.

    2010-09-06T23:59:59.000Z

    The geometric and electronic structures, as well as the thermodynamic properties of trivalent lanthanide hydrates {Ln(H?O)?,? ? and Ln(H?O)?,?(H?O)??,?? ?, Ln = La Lu} have been examined using unrestricted density functional theory (UDFT), unrestricted Moller-Plesset perturbation theory (UMP2), and multiconfigurational self-consistent field methods (MCSCF). While Ln-hydrates with 2-5 unpaired f-electrons have some multiconfigurational character, the correlation energy lies within 5-7 kcal/mol across the period and for varying coordination numbers. As such DFT yields structural parameters and thermodynamic data quite close to experimental values. Both UDFT and UMP2 predict free energies of water addition to the Ln(H?O)? ? species to become less favorable across the period; however, it is a non-linear function of the surface charge density of the ion. UDFT further predicts that the symmetry of the metal-water bond lengths is sensitive to the specific f-electron configuration, presumably because of repulsive interactions between filled f-orbitals and water lone-pairs. Within the Ln(H?O)?,?(H?O)??,?? ?clusters, interactions between solvation shells overrides this orbital effect, increasing the accuracy of the geometric parameters and calculated vibrational frequencies. Calculated atomic charges indicate that the water ligands each donate 0.1 to 0.2 electrons to the Ln(III) metals, with increasing electron donation across the period. Significant polarization and charge transfer between solvation shells is also observed. The relationship between empirical effective charges and calculated atomic charges is discussed with suggestions for reconciling the trends across the period.

  11. Solid State Division progress report for period ending March 31, 1997

    SciTech Connect (OSTI)

    Green, P.H.; Hinton, L.W. [eds.

    1997-12-01T23:59:59.000Z

    This report covers research progress in the Solid State Division from April 1, 1995, through March 31, 1997. During this period, the division conducted a broad, interdisciplinary materials research program in support of Department of Energy science and technology missions. The report includes brief summaries of research activities in condensed matter theory, neutron scattering, synthesis and characterization of materials, ion beam and laser processing, and the structure of solids and surfaces. An addendum includes listings of division publications and professional activities.

  12. Solid State Division progress report for period ending September 30, 1984

    SciTech Connect (OSTI)

    Green, P.H.; Watson, D.M. (eds.)

    1985-03-01T23:59:59.000Z

    During the reporting period, relatively minor changes have occurred in the research areas of interest to the Division. Nearly all the research of the Division can be classified broadly as mission-oriented basic research. Topics covered include: theoretical solid state physics; surface and near-surface properties of solids; defects in solids; transport properties of solids; neutron scattering; and preparation and characterization of research materials. (GHT)

  13. Engineering Physics and Mathematics Division progress report for period ending December 31, 1992

    SciTech Connect (OSTI)

    Ward, R.C.

    1993-05-01T23:59:59.000Z

    In this report, our research is described through abstracts of journal articles, technical reports, and presentations organized into sections following the five major operating units in the division: Mathematical Sciences, Intelligent Systems, Nuclear Data and Measurement Analysis, Nuclear Analysis and Shielding, and the Engineering Physics Information Centers. Each section begins with an introduction highlighting honors, awards, and significant research accomplishments in that unit during the reporting period.

  14. Short-rotation woody-crops program. Quarterly progress report for period ending August 31, 1981

    SciTech Connect (OSTI)

    Cushman, J.H.; Ranney, J.W.

    1982-04-01T23:59:59.000Z

    Progress of twenty-one projects in the Short Rotation Woody Crops Program is summarized for the period June 1 through August 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major program activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

  15. Comparison of the afterripening period of peach seeds with the chilling requirements of the parent variety

    E-Print Network [OSTI]

    Worthington, Josiah Wistar

    1966-01-01T23:59:59.000Z

    of afterripening to chilling requirement of' parent V. SUMMARY AND CONCLUSIONS 20 26 29 LITERATURE CITED APPENDIX 34 Seed hydration as affected by soaking period Seed germination as influenced by seed hydration during afterripening 35 Germination of.... Influence of stratification time on germi- nation of S-37 and Okinawa peach seeds Page 22 LIST OF FIGURES 1. Seed hydration a. influenced by soaking Page 16 2. Afterripening effectiveness as influenced by pre- soaking seeds 17 3. Germination...

  16. Periodic Modulations in an X-ray Flare from Sagittarius A*

    E-Print Network [OSTI]

    Guillaume Belanger; Regis Terrier; Okkie De Jager; Andrea Goldwurm; Fulvio Melia

    2006-04-23T23:59:59.000Z

    We present the highly significant detection of a quasi-periodic flux modulation with a period of 22.2 min seen in the X-ray data of the Sgr A* flare of 2004 August 31. This flaring event, which lasted a total of about three hours, was detected simultaneously by EPIC on XMM-Newton and the NICMOS near-infrared camera on the HST. Given the inherent difficulty in, and the lack of readily available methods for quantifying the probability of a periodic signal detected over only several cycles in a data set where red noise can be important, we developed a general method for quantifying the likelihood that such a modulation is indeed intrinsic to the source and does not arise from background fluctuations. We here describe this Monte Carlo based method, and discuss the results obtained by its application to a other XMM-Newton data sets. Under the simplest hypothesis that we witnessed a transient event that evolved, peaked and decayed near the marginally stable orbit of the supermassive black hole, this result implies that for a mass of 3.5 x 10^{6} Msun, the central object must have an angular momentum corresponding to a spin parameter of a=0.22.

  17. Method and apparatus of periodically obtaining accurate opacity monitor readings of an exhaust gas stream

    SciTech Connect (OSTI)

    Weaver, K.L.; Bellows, J.C.

    1990-01-23T23:59:59.000Z

    This patent describes in an opacity monitor associated with an exhaust stack, the monitor having a transmitter and a receiving which cooperate to measure a quantity of particulate matter in an exhaust gas stream, a method of periodically obtaining opacity monitor readings. It comprises: shielding the monitor from the exhaust gas stream by placing two windows adjacent to the monitor, a first window being placed between the transmitter and the exhaust gas stream and a second window being placed between the receiver and the exhaust gas stream; cleaning at least one of the windows for a first predetermined time period by spraying a volatile nonflammable cleaning solvent onto the window by means of a sprayer intermittently operable during the first predetermined time period while wiping the window with a reciprocating wiper arm in resilient engagement therewith; then obtaining an opacity monitor reading by directing a light beam across the exhaust stack from the transmitter via the first window through the exhaust gas stream to the receiver via the second window; and alternately repeating the step of cleaning the window with the step of obtaining an opacity monitor reading.

  18. The ACS LCID Project. VIII. The short-period Cepheids of Leo A

    E-Print Network [OSTI]

    Bernard, Edouard J; Gallart, Carme; Fiorentino, Giuliana; Cassisi, Santi; Aparicio, Antonio; Cole, Andrew A; Drozdovsky, Igor; Hidalgo, Sebastian L; Skillman, Evan D; Stetson, Peter B; Tolstoy, Eline

    2013-01-01T23:59:59.000Z

    We present the results of a new search for variable stars in the Local Group dwarf galaxy Leo A, based on deep photometry from the Advanced Camera for Surveys onboard the Hubble Space Telescope. We detected 166 bona fide variables in our field, of which about 60 percent are new discoveries, and 33 candidate variables. Of the confirmed variables, we found 156 Cepheids, but only 10 RR Lyrae stars despite nearly 100 percent completeness at the magnitude of the horizontal branch. The RR Lyrae stars include 7 fundamental and 3 first-overtone pulsators, with mean periods of 0.636 and 0.366 day, respectively. From their position on the period-luminosity (PL) diagram and light-curve morphology, we classify 91, 58, and 4 Cepheids as fundamental, first-overtone, and second-overtone mode Classical Cepheids (CC), respectively, and two as population II Cepheids. However, due to the low metallicity of Leo A, about 90 percent of the detected Cepheids have periods shorter than 1.5 days. Comparison with theoretical models ind...

  19. Three Packets of Minerals of the Periodic Table of Chemical Elements and Chemical Compounds

    E-Print Network [OSTI]

    Labushev, Mikhail M

    2013-01-01T23:59:59.000Z

    The concepts of alpha- and beta-packets of the periodic table of chemical elements and chemical compounds are defined. The first of the 47 minerals alpha-packets is composed. In it all minerals are arranged in increasing Iav index of proportionality of atomic weights of composing chemical elements, the same way as chemical elements are located in increasing atomic weights in the Periodic table. The packet includes 93 known minerals and two compounds - N2O5 and CO2 - being actually minerals. Beta-packet of oxides and hydroxides minerals includes 88 known minerals and five chemical compounds - N2O5, CO2, CO, SO3 and SO2. Two minerals of the packet have not been determined yet. Besides, beta-packet of minerals with sulfur, selenium or arsenic is composed, with one mineral not defined yet. The results of the calculations can be used for further development of the Periodic Table of Chemical Elements and Chemical Compounds and their properties investigation.

  20. Three Packets of Minerals of the Periodic Table of Chemical Elements and Chemical Compounds

    E-Print Network [OSTI]

    Mikhail M. Labushev

    2013-03-20T23:59:59.000Z

    The concepts of alpha- and beta-packets of the periodic table of chemical elements and chemical compounds are defined. The first of the 47 minerals alpha-packets is composed. In it all minerals are arranged in increasing Iav index of proportionality of atomic weights of composing chemical elements, the same way as chemical elements are located in increasing atomic weights in the Periodic table. The packet includes 93 known minerals and two compounds - N2O5 and CO2 - being actually minerals. Beta-packet of oxides and hydroxides minerals includes 88 known minerals and five chemical compounds - N2O5, CO2, CO, SO3 and SO2. Two minerals of the packet have not been determined yet. Besides, beta-packet of minerals with sulfur, selenium or arsenic is composed, with one mineral not defined yet. The results of the calculations can be used for further development of the Periodic Table of Chemical Elements and Chemical Compounds and their properties investigation.

  1. Femtosecond laser-induced periodic surface structure on the Ti-based nanolayered thin films

    SciTech Connect (OSTI)

    Petrovi?, Suzana M.; Gakovi?, B.; Peruko, D. [Institute of Nuclear ScienceVin?a, University of Belgrade, POB 522, 11001 Belgrade (Serbia)] [Institute of Nuclear ScienceVin?a, University of Belgrade, POB 522, 11001 Belgrade (Serbia); Stratakis, E. [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece) [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece); Department of Materials Science and Technology, University of Crete, 710 03 Heraklion, Crete (Greece); Bogdanovi?-Radovi?, I. [Ru?er Bokovi? Institute, P.O. Box 180, 10002 Zagreb (Croatia)] [Ru?er Bokovi? Institute, P.O. Box 180, 10002 Zagreb (Croatia); ?ekada, M. [Joef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)] [Joef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Fotakis, C. [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece) [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece); Department of Physics, University of Crete, 714 09 Heraklion, Crete (Greece); Jelenkovi?, B. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)] [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

    2013-12-21T23:59:59.000Z

    Laser-induced periodic surface structures (LIPSSs) and chemical composition changes of Ti-based nanolayered thin films (Al/Ti, Ni/Ti) after femtosecond (fs) laser pulses action were studied. Irradiation is performed using linearly polarized Ti:Sapphire fs laser pulses of 40 fs pulse duration and 800 nm wavelength. The low spatial frequency LIPSS (LSFL), oriented perpendicular to the laser polarization with periods slightly lower than the irradiation wavelength, was typically formed at elevated laser fluences. On the contrary, high spatial frequency LIPSS (HSFL) with uniform period of 155 nm, parallel to the laser light polarization, appeared at low laser fluences, as well as in the wings of the Gaussian laser beam distribution for higher used fluence. LSFL formation was associated with the material ablation process and accompanied by the intense formation of nanoparticles, especially in the Ni/Ti system. The composition changes at the surface of both multilayer systems in the LSFL area indicated the intermixing between layers and the substrate. Concentration and distribution of all constitutive elements in the irradiated area with formed HSFLs were almost unchanged.

  2. A comparative study of four significance measures for periodicity detection in astronomical surveys

    E-Print Network [OSTI]

    Sveges, Maria; Eyer, Laurent; Cuypers, Jan; Holl, Berry; Lecoeur-Tabi, Isabelle; Mowlavi, Nami; Nienartowicz, Krzysztof; Blanco, Diego Ordez; Rimoldini, Lorenzo; Ruiz, Idoia

    2015-01-01T23:59:59.000Z

    We study the problem of periodicity detection in massive data sets of photometric or radial velocity time series, as presented by ESA's Gaia mission. Periodicity detection hinges on the estimation of the false alarm probability (FAP) of the extremum of the periodogram of the time series. We consider the problem of its estimation with two main issues in mind. First, for a given number of observations and signal-to-noise ratio, the rate of correct periodicity detections should be constant for all realized cadences of observations regardless of the observational time patterns, in order to avoid sky biases that are difficult to assess. Second, the computational loads should be kept feasible even for millions of time series. Using the Gaia case, we compare the $F^M$ method (Paltani 2004, Schwarzenberg-Czerny 2012), the Baluev method (Baluev 2008) and the GEV method (S\\"uveges 2014), as well as a method for the direct estimation of a threshold. Three methods involve some unknown parameters, which are obtained by fi...

  3. PLANET HUNTERS: ASSESSING THE KEPLER INVENTORY OF SHORT-PERIOD PLANETS

    SciTech Connect (OSTI)

    Schwamb, Megan E. [Yale Center for Astronomy and Astrophysics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Lintott, Chris J.; Lynn, Stuart; Smith, Arfon M.; Simpson, Robert J. [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Fischer, Debra A.; Giguere, Matthew J.; Brewer, John M. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Parrish, Michael [Adler Planetarium, 1300 S. Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin, E-mail: megan.schwamb@yale.edu [Department of Physics, Yale University, New Haven, CT 06511 (United States)

    2012-08-01T23:59:59.000Z

    We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of {>=}2 R{sub Circled-Plus} planets on short-period (<15 days) orbits based on Planet Hunters detections. We present these results along with an analysis of the detection efficiency of human classifiers to identify planetary transits including a comparison to the Kepler inventory of planet candidates. Although performance drops rapidly for smaller radii, {>=}4 R{sub Circled-Plus} Planet Hunters {>=}85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler {>=}4 R{sub Circled-Plus} planets suggests that the Kepler inventory of {>=}4 R{sub Circled-Plus} short-period planets is nearly complete.

  4. Separation of suspended particles in microfluidic systems by directional-locking in periodic fields

    E-Print Network [OSTI]

    John Herrmann; Michael Karweit; German Drazer

    2009-04-16T23:59:59.000Z

    We investigate the transport and separation of overdamped particles under the action of a uniform external force in a two-dimensional periodic energy landscape. Exact results are obtained for the deterministic transport in a square lattice of parabolic, repulsive centers that correspond to a piecewise-continuous linear-force model. The trajectories are periodic and commensurate with the obstacle lattice and exhibit phase-locking behavior in that the particle moves at the same average migration angle for a range of orientation of the external force. The migration angle as a function of the orientation of the external force has a Devil's staircase structure. The first transition in the migration angle was analyzed in terms of a Poincare map, showing that it corresponds to a tangent bifurcation. Numerical results show that the limiting behavior for impenetrable obstacles is equivalent to the high Peclet number limit in the case of transport of particles in a periodic pattern of solid obstacles. Finally, we show how separation occurs in these systems depending on the properties of the particles.

  5. THE VELOCITY CENTROID PERIODICITY OF L2 PUPPIS' SiO MASER EMISSION

    SciTech Connect (OSTI)

    McIntosh, Gordon C. [Division of Science and Mathematics, University of Minnesota, Morris, Morris, MN 56267 (United States); Indermuehle, Balthasar [Australia Telescope National Facility, Locked Bag 194, Narrabri, NSW 2390 (Australia)

    2013-09-01T23:59:59.000Z

    We report the first short term velocity centroid (VC) periodicity derived from SiO maser emission. L2 Puppis, a semi-regular AGB star, was observed using the Mopra radio telescope of the Australia Telescope National Facility in the SiO v = 1, J = 1-0 and v = 1, J = 2-1 transitions. It exhibits a 139 day period in its SiO maser VC based on a period folding analysis and a Lomb Scargle analysis. L2 Pup's SiO maser emission has an unusually large velocity range and an unusual three-peaked spectrum. To create the change in VC the entire spectrum does not shift in velocity, but changes in the relative emission of the peaks generate the variation. The changes in the VC may be due to differential illumination, an asymmetric circumstellar distribution of material, or a mixture of causes. The unusual velocity structure, similar to that observed in Orion source 1, may be due to revolution of the circumstellar material or asymmetries in the circumstellar environment.

  6. QUASI-PERIODIC OSCILLATIONS AND BROADBAND VARIABILITY IN SHORT MAGNETAR BURSTS

    SciTech Connect (OSTI)

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

    2013-05-01T23:59:59.000Z

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

  7. EXPLORING THE VARIABLE SKY WITH LINEAR. III. CLASSIFICATION OF PERIODIC LIGHT CURVES

    SciTech Connect (OSTI)

    Palaversa, Lovro; Eyer, Laurent; Rimoldini, Lorenzo [Observatoire Astronomique de l'Universit de Genve, 51 chemin des Maillettes, CH-1290 Sauverny (Switzerland); Ivezi?, eljko; Loebman, Sarah; Hunt-Walker, Nicholas; VanderPlas, Jacob; Westman, David; Becker, Andrew C. [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195-1580 (United States); Rudjak, Domagoj; Sudar, Davor; Boi?, Hrvoje [Hvar Observatory, Faculty of Geodesy, Ka?i?eva 26, 10000 Zagreb (Croatia); Galin, Mario [Faculty of Geodesy, Ka?i?eva 26, 10000 Zagreb (Croatia); Kroflin, Andrea; Mesari?, Martina; Munk, Petra; Vrbanec, Dijana [Department of Physics, Faculty of Science, University of Zagreb, Bijeni?ka cesta 32, 10000 Zagreb (Croatia); Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, Caltech, Pasadena, CA 91125 (United States); Stuart, J. Scott [Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, MA 02420-9108 (United States); Srdo?, Gregor, E-mail: lovro.palaversa@unige.ch [Saroni 90, 51216 Vikovo (Croatia); and others

    2013-10-01T23:59:59.000Z

    We describe the construction of a highly reliable sample of ?7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg{sup 2} of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit is several magnitudes fainter than most other wide-angle surveys; the photometric errors range from ?0.03 mag at r = 15 to ?0.20 mag at r = 18. Light curves include on average 250 data points, collected over about a decade. Using Sloan Digital Sky Survey (SDSS) based photometric recalibration of the LINEAR data for about 25 million objects, we selected ?200,000 most probable candidate variables with r < 17 and visually confirmed and classified ?7000 periodic variables using phased light curves. The reliability and uniformity of visual classification across eight human classifiers was calibrated and tested using a catalog of variable stars from the SDSS Stripe 82 region and verified using an unsupervised machine learning approach. The resulting sample of periodic LINEAR variables is dominated by 3900 RR Lyrae stars and 2700 eclipsing binary stars of all subtypes and includes small fractions of relatively rare populations such as asymptotic giant branch stars and SX Phoenicis stars. We discuss the distribution of these mostly uncataloged variables in various diagrams constructed with optical-to-infrared SDSS, Two Micron All Sky Survey, and Wide-field Infrared Survey Explorer photometry, and with LINEAR light-curve features. We find that the combination of light-curve features and colors enables classification schemes much more powerful than when colors or light curves are each used separately. An interesting side result is a robust and precise quantitative description of a strong correlation between the light-curve period and color/spectral type for close and contact eclipsing binary stars (? Lyrae and W UMa): as the color-based spectral type varies from K4 to F5, the median period increases from 5.9 hr to 8.8 hr. These large samples of robustly classified variable stars will enable detailed statistical studies of the Galactic structure and physics of binary and other stars and we make these samples publicly available.

  8. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,1999 THRIUGH FEBRUARY 29,2000

    SciTech Connect (OSTI)

    LC BROWN

    2000-02-29T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,1999 THRIUGH FEBRUARY 29,2000

  9. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD OCTOBER 1,2001 THROUGH DECEMBER 31,2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2001-12-31T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD OCTOBER 1,2001 THROUGH DECEMBER 31,2001

  10. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,2000 THROUGH FEBRUARY 28,2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2000-02-28T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,2000 THROUGH FEBRUARY 28,2001

  11. DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD AUGUST 15,2000 THROUGH SEPTEMBER 30,2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2002-02-01T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD AUGUST 15,2000 THROUGH SEPTEMBER 30,2001

  12. DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD OCTOBER 1, 2001 THROUGH DECEMBER 31, 2002

    SciTech Connect (OSTI)

    L.C. BROWN

    2003-04-07T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD OCTOBER 1, 2001 THROUGH DECEMBER 31, 2002

  13. Lessons learned from the ATLAS performance studies of the Iberian Cloud for the first LHC running period.

    E-Print Network [OSTI]

    Snchez-Martnez, V; The ATLAS collaboration; Borrego, C; del Peso, J; Delfino, M; Gomes, J; Gonzlez de la Hoz, S; Pacheco Pages, A; Salt, J; Sedov, A; Villaplana, M; Wolters, H

    2013-01-01T23:59:59.000Z

    Poster: Lessons learned from the ATLAS performance studies of the Iberian Cloud for the first LHC running period. Conference: CHEP2013 - Amsterdam.

  14. The generalization of A. E. Kennelly theory of complex representation of the electrical quantities in sinusoidal periodic regime to the one and three-phase electric quantities in non-sinusoidal periodic regime

    E-Print Network [OSTI]

    Gheorghe Mihai

    2010-02-12T23:59:59.000Z

    In this paper, a new mathematical method of electrical circuits calculus is proposed based on the theory of the complex linear operators in matrix form. The newly proposed method generalizes the theory of complex representation of electrical quantities in sinusoidal periodic regime to the non-sinusoidal periodic regime.

  15. Impact of Paint Color on Rest Period Climate Control Loads in Long-Haul Trucks: Preprint

    SciTech Connect (OSTI)

    Lustbader, J.; Kreutzer, C.; Jeffers, M.; Adelman, S.; Yeakel, S.; Brontz, P.; Olson, K.; Ohlinger, J.

    2014-02-01T23:59:59.000Z

    Cab climate conditioning is one of the primary reasons for operating the main engine in a long-haul truck during driver rest periods. In the United States, sleeper cab trucks use approximately 667 million gallons of fuel annually for rest period idling. The U.S. Department of Energy's National Renewable Energy Laboratory's (NREL) CoolCab Project works closely with industry to design efficient thermal management systems for long-haul trucks that minimize engine idling and fuel use while maintaining occupant comfort. Heat transfer to the vehicle interior from opaque exterior surfaces is one of the major heat pathways that contribute to air conditioning loads during long-haul truck daytime rest period idling. To quantify the impact of paint color and the opportunity for advanced paints, NREL collaborated with Volvo Group North America, PPG Industries, and Dometic Environmental Corporation. Initial screening simulations using CoolCalc, NREL's rapid HVAC load estimation tool, showed promising air-conditioning load reductions due to paint color selection. Tests conducted at NREL's Vehicle Testing and Integration Facility using long-haul truck cab sections, 'test bucks,' showed a 31.1% of maximum possible reduction in rise over ambient temperature and a 20.8% reduction in daily electric air conditioning energy use by switching from black to white paint. Additionally, changing from blue to an advanced color-matched solar reflective blue paint resulted in a 7.3% reduction in daily electric air conditioning energy use for weather conditions tested in Colorado. National-level modeling results using weather data from major U.S. cities indicated that the increase in heating loads due to lighter paint colors is much smaller than the reduction in cooling loads.

  16. Induced cooperative motions in a medium driven at the nanoscale: Searching for an optimum excitation period

    E-Print Network [OSTI]

    Victor Teboul; Jean-Baptiste Accary

    2014-04-05T23:59:59.000Z

    Recent results have shown the appearance of induced cooperative motions called dynamic heterogeneity during the isomerization of diluted azobenzene molecules in a host glass-former. In this paper we raise the issue of the coupling between these "artificial" heterogeneities and the isomerization period. How do these induced heterogeneities differ in the saturation regime and in the linear response regime ? Is there a maximum of the heterogeneous motion versus isomerization rate and why ? Are the heterogeneity evolution with the isomerization rate connected with the diffusion or relaxation time evolution ? We use out of equilibrium molecular dynamics simulations to answer these questions. We find that the heterogeneity increases in the linear response regime for large isomerization periods and small perturbations. In contrast the heterogeneity decreases in the saturation regime, i.e. when the isomerization half-period ($\\tau_{p}/2$) is smaller than the relaxation time of the material ($\\tau_{\\alpha}$). This result makes possible a test of the effect of cooperative motions on the dynamics using the chromophores as Maxwell demons that destroy or stimulate the cooperative motions. Because the heterogeneities increase in the linear regime and then decrease in the saturation regime, we find a maximum for $\\tau_{p}/2 \\approx \\tau_{\\alpha}$. The induced excitations concentration follows a power law evolution versus the isomerization rate and then saturates. As a consequence the $\\alpha$ relaxation time is related to the excitation concentration with a power law, a result in qualitative agreement with recent findings in constrained models. This result supports a common origin for the heterogeneities with constrained models and a similar relation to the excitation concentration.

  17. Nonlinear, stationary electrostatic ion cyclotron waves: Exact solutions for solitons, periodic waves, and wedge shaped waveforms

    SciTech Connect (OSTI)

    McKenzie, J. F. [Department of Mathematics, Statistics and Physics, Durban University of Technology, Steve Biko Campus, Durban 4001 (South Africa); School of Mathematical Sciences, University of KwaZulu-Natal, Private Bag: X54001, Durban 4001 (South Africa); Doyle, T. B. [Materials Research Division, iThemba LABS, P.O.Box 722, Somerset West, 7129, South Africa and School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag: X54001, Durban 4001 (South Africa); Rajah, S. S. [Department of Mathematics, Statistics and Physics, Durban University of Technology, Steve Biko Campus, Durban 4001 (South Africa)

    2012-11-15T23:59:59.000Z

    The theory of fully nonlinear stationary electrostatic ion cyclotron waves is further developed. The existence of two fundamental constants of motion; namely, momentum flux density parallel to the background magnetic field and energy density, facilitates the reduction of the wave structure equation to a first order differential equation. For subsonic waves propagating sufficiently obliquely to the magnetic field, soliton solutions can be constructed. Importantly, analytic expressions for the amplitude of the soliton show that it increases with decreasing wave Mach number and with increasing obliquity to the magnetic field. In the subsonic, quasi-parallel case, periodic waves exist whose compressive and rarefactive amplitudes are asymmetric about the 'initial' point. A critical 'driver' field exists that gives rise to a soliton-like structure which corresponds to infinite wavelength. If the wave speed is supersonic, periodic waves may also be constructed. The aforementioned asymmetry in the waveform arises from the flow being driven towards the local sonic point in the compressive phase and away from it in the rarefactive phase. As the initial driver field approaches the critical value, the end point of the compressive phase becomes sonic and the waveform develops a wedge shape. This feature and the amplitudes of the compressive and rarefactive portions of the periodic waves are illustrated through new analytic expressions that follow from the equilibrium points of a wave structure equation which includes a driver field. These expressions are illustrated with figures that illuminate the nature of the solitons. The presently described wedge-shaped waveforms also occur in water waves, for similar 'transonic' reasons, when a Coriolis force is included.

  18. GALACTIC COSMIC-RAY ENERGY SPECTRA AND COMPOSITION DURING THE 2009-2010 SOLAR MINIMUM PERIOD

    SciTech Connect (OSTI)

    Lave, K. A.; Binns, W. R.; Israel, M. H. [Department of Physics and the McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States); Wiedenbeck, M. E. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Christian, E. R.; De Nolfo, G. A.; Von Rosenvinge, T. T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Cummings, A. C.; Davis, A. J.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C. [California Institute of Technology, Pasadena, CA 91125 (United States)

    2013-06-20T23:59:59.000Z

    We report new measurements of the elemental energy spectra and composition of galactic cosmic rays during the 2009-2010 solar minimum period using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer. This period of time exhibited record-setting cosmic-ray intensities and very low levels of solar activity. Results are given for particles with nuclear charge 5 {<=} Z {<=} 28 in the energy range {approx}50-550 MeV nucleon{sup -1}. Several recent improvements have been made to the earlier CRIS data analysis, and therefore updates of our previous observations for the 1997-1998 solar minimum and 2001-2003 solar maximum are also given here. For most species, the reported intensities changed by less than {approx}7%, and the relative abundances changed by less than {approx}4%. Compared with the 1997-1998 solar minimum relative abundances, the 2009-2010 abundances differ by less than 2{sigma}, with a trend of fewer secondary species observed in the more recent time period. The new 2009-2010 data are also compared with results of a simple ''leaky-box'' galactic transport model combined with a spherically symmetric solar modulation model. We demonstrate that this model is able to give reasonable fits to the energy spectra and the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe. These results are also shown to be comparable to a GALPROP numerical model that includes the effects of diffusive reacceleration in the interstellar medium.

  19. Time-delayed feedback control of unstable periodic orbits near a subcritical Hopf bifurcation

    E-Print Network [OSTI]

    Genevieve Brown; Claire M. Postlethwaite; Mary Silber

    2010-06-17T23:59:59.000Z

    We show that Pyragas delayed feedback control can stabilize an unstable periodic orbit (UPO) that arises from a generic subcritical Hopf bifurcation of a stable equilibrium in an n-dimensional dynamical system. This extends results of Fiedler et al. [PRL 98, 114101 (2007)], who demonstrated that such feedback control can stabilize the UPO associated with a two-dimensional subcritical Hopf normal form. Pyragas feedback requires an appropriate choice of a feedback gain matrix for stabilization, as well as knowledge of the period of the targeted UPO. We apply feedback in the directions tangent to the two-dimensional center manifold. We parameterize the feedback gain by a modulus and a phase angle, and give explicit formulae for choosing these two parameters given the period of the UPO in a neighborhood of the bifurcation point. We show, first heuristically, and then rigorously by a center manifold reduction for delay differential equations, that the stabilization mechanism involves a highly degenerate Hopf bifurcation problem that is induced by the time-delayed feedback. When the feedback gain modulus reaches a threshold for stabilization, both of the genericity assumptions associated with a two-dimensional Hopf bifurcation are violated: the eigenvalues of the linearized problem do not cross the imaginary axis as the bifurcation parameter is varied, and the real part of the cubic coefficient of the normal form vanishes. Our analysis of this degenerate bifurcation problem reveals two qualitatively distinct cases when unfolded in a two-parameter plane. In each case, Pyragas-type feedback successfully stabilizes the branch of small-amplitude UPOs in a neighborhood of the original bifurcation point, provided that the phase angle satisfies a certain restriction.

  20. Photoreduction of metal nanostructures on periodically proton exchanged MgO-doped lithium niobate crystals

    SciTech Connect (OSTI)

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

    2013-10-28T23:59:59.000Z

    Local reactivity on periodically proton exchanged lithium niobate (PPE:LN) surfaces is a promising route for the fabrication of regularly spaced nanostructures. Here, using MgO-doped PPE:LN templates, we investigate the influence of the doping on the nanostructure formation as a function of the proton exchange (PE) depth. The deposition is found to occur preferentially along the boundary between MgO-doped LN and the PE region when the PE depth is at least 1.73 ?m, however, for shallower depths, deposition occurs across the entire PE region. The results are found to be consistent with an increased photoconductivity of the MgO-doped LN.

  1. Analytical Chemistry Division annual progress report for period ending December 31, 1992

    SciTech Connect (OSTI)

    Shults, W.D.

    1993-04-01T23:59:59.000Z

    This report is divided into: Analytical spectroscopy (optical spectroscopy, organic mass spectrometry, inorganic mass spectrometry, secondary ion mass spectrometry), inorganic and radiochemistry (transuranium and activation analysis, low-level radiochemical analysis, inorganic analysis, radioactive materials analysis, special projects), organic chemistry (organic spectroscopy, separations and synthesis, special projects, organic analysis, ORNL/UT research program), operations (quality assurance/quality control, environmental protection, safety, analytical improvement, training, radiation control), education programs, supplementary activities, and presentation of research results. Tables are included for articles reviewed or refereed for periodicals, analytical service work, division manpower and financial summary, and organization chart; a glossary is also included.

  2. Observations and seasonal periodicity of the benthic algae of Galveston Island, Texas

    E-Print Network [OSTI]

    Lowe, Glenn Curtis

    1975-01-01T23:59:59.000Z

    on the marine algae of Florida: The intertidal rocks at Marineland. Florida State Univ. Stud. 7: 17-23. 1956. Sea grasses of the northern Gulf coast. Bull. Mar. Sc. Gulf & Carib. 4: 305-308. 1963. Some new records and range extensions of Florida marine... an extensive study dealing with periodicity and dis- tribution of benthic marine algae in Louisiana. Offshore collec- tions were made in addition to well-spaced sites along the coast. Keatts (196g, unpublished} surveyed the algae on a rock jetty in Freeport...

  3. Black and white: a portrayal of gender roles in American women's periodicals during the Eisenhour years

    E-Print Network [OSTI]

    McGaugh, Emily Cozette

    1996-01-01T23:59:59.000Z

    extent Ebony and Negro Digest. g THIS THESIS The research of Friedan, Deckard, Franzwa, Peck, May, and Meyerowitz is important. This thesis builds on their work by employing a wider range of periodicals, those most popular among females between 1953... by several male and female doctors and summarized: "Few Negro women believe that a woman's place is in the home. . . . the role of the American Negm woman is a family life of home and marriage and some outside interest. Those who want a career should have...

  4. Quarterly report of RCRA groundwater monitoring data for period July 1--September 30, 1995

    SciTech Connect (OSTI)

    NONE

    1996-01-01T23:59:59.000Z

    Nineteen RCRA groundwater monitoring projects are conducted at the Hanford site. They include treatment, storage, and disposal facilities for both solid and liquid waste. Groundwater monitoring programs described in this report comply with the interim- and final- status federal and state regulations. The RCRA projects are monitored under one of the following programs: background monitoring, indicator parameter evaluation, or groundwater quality assessment or detection. This quarterly report contains data received between July 1 and Sept. 30, 1995, which are the cutoff dates for this reporting period. This report may contain not only data from the July-Sept. quarter, but also data from earlier sampling events not previously reported.

  5. Phase-locking of driven vortex lattices with transverse ac force and periodic pinning

    SciTech Connect (OSTI)

    Reichhardt, Charles; Kolton, Alejandro B.; Dominguez, Daniel; Gronbech-Jensen, Niels

    2001-10-01T23:59:59.000Z

    For a vortex lattice moving in a periodic array we show analytically and numerically that a new type of phase locking occurs in the presence of a longitudinal dc driving force and a transverse ac driving force. This phase locking is distinct from the Shapiro step phase locking found with longitudinal ac drives. We show that an increase in critical current and a fundamental phase-locked step width scale with the square of the driving ac amplitude. Our results should carry over to other systems such as vortex motion in Josephson-junction arrays.

  6. The No-Boundary Wave Function and the Duration of the Inflationary Period

    E-Print Network [OSTI]

    A. Lukas

    1994-09-07T23:59:59.000Z

    For the simplest minisuperspace model based on a homogeneous, isotropic metric and a minimally coupled scalar field we derive analytic expressions for the caustic which separates Euklidean and Minkowskian region and its breakdown value $\\p_*$. This value represents the prediction of the no-boundary wave function for the scalar field at the beginning of inflation. We use our results to search for inflationary models which can render the no-boundary wave function consistent with the requirement of a sufficiently long inflationary period.

  7. Femtosecond diffraction dynamics of laser-induced periodic surface structures on fused silica

    SciTech Connect (OSTI)

    Hoehm, S.; Rosenfeld, A. [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strasse 2A, D-12489 Berlin (Germany)] [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strasse 2A, D-12489 Berlin (Germany); Krueger, J.; Bonse, J. [BAM Bundesanstalt fuer Materialforschung und - pruefung, Unter den Eichen 87, D-12205 Berlin (Germany)] [BAM Bundesanstalt fuer Materialforschung und - pruefung, Unter den Eichen 87, D-12205 Berlin (Germany)

    2013-02-04T23:59:59.000Z

    The formation of laser-induced periodic surface structures (LIPSS) on fused silica upon irradiation with linearly polarized fs-laser pulses (50 fs pulse duration, 800 nm center wavelength) is studied experimentally using a transillumination femtosecond time-resolved (0.1 ps-1 ns) pump-probe diffraction approach. This allows to reveal the generation dynamics of near-wavelength-sized LIPSS showing a transient diffraction at specific spatial frequencies even before a corresponding permanent surface relief was observed. The results confirm that the ultrafast energy deposition to the materials surface plays a key role and triggers subsequent physical mechanisms such as carrier scattering into self-trapped excitons.

  8. Differences between measured and linearly interpolated synoptic variables over a 12-h period during AVE IV

    E-Print Network [OSTI]

    Dupuis, Leonard Raymond

    1979-01-01T23:59:59.000Z

    , Z4 April 1975. (after Fucik and Turner, 1975). 590 440 1D 1Dy ~ m 9 soo 530 560 18~ 530 I 22 ? g --' I / '3 22 0 590 20 338 530 16 850 mb 4 4 090 8 m 2D ? ? ? 6 ( ', -k 5 150 8 I '30 ~ 8O '4 210 210 700 BIb Fig. 6. (Cont3nued...DIFFERENCES BETWEEN MEASURED AND LINEARLY INTERPOLATED SYNOPTIC VARIABLES OVER A 12-h PERIOD DURING AVE IV A Thesis by LEONARD RAYMOND DUPUIS Submitted to the Graduate College of Texas A&M University in partial ful. fillment...

  9. HTGR Generic Technology Program. Semiannual report for the period ending September 30, 1980

    SciTech Connect (OSTI)

    Not Available

    1980-11-01T23:59:59.000Z

    This document reports the technical accomplishments on the HTGR Generic Technology Program at General Atomic during the second half of FY-80. It covers a period when the design direction of the National HTGR Program is in the process of an overall review. The HTGR Generic Technology Program activities have continued so as to provide the basic technology required for all HTGR applications. The activities include the need to develop an LEU fuel and the need to qualify materials and components for the higher temperatures of the gas turbines and process heat plants.

  10. PARC Periodical-Volume 5, Issue 4 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanningP-GlycoproteinAmmoniaPeriodical

  11. PARC Periodical-Volume 5, Issue 6 | Photosynthetic Antenna Research Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002Optics GroupPlanningP-GlycoproteinAmmoniaPeriodicalVolume

  12. Property:Building/SPPurchasedEngyForPeriodMwhYrWoodChips | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revision hasInformationInyo County, CaliforniaInformation SPPurchasedEngyForPeriodMwhYrWoodChips Jump to:

  13. Property:OpenEI/UtilityRate/DemandChargePeriod2 | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County,ContAddr2NumberOfPrograms Jump to:URI Jump to:DemandChargePeriod2 Jump

  14. Property:OpenEI/UtilityRate/DemandChargePeriod2FAdj | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County,ContAddr2NumberOfPrograms Jump to:URI Jump to:DemandChargePeriod2

  15. Property:OpenEI/UtilityRate/DemandChargePeriod4 | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County,ContAddr2NumberOfPrograms Jump to:URI Jump Name: Demand Charge Period 4

  16. Property:OpenEI/UtilityRate/DemandChargePeriod4FAdj | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: Energy ResourcesLoadingPenobscot County,ContAddr2NumberOfPrograms Jump to:URI Jump Name: Demand Charge Period

  17. Long-period fiber grating inscription under high-intensity 352 nm femtosecond irradiation: Three-photon absorption

    E-Print Network [OSTI]

    Nikogosyan, David N.

    Long-period fiber grating inscription under high-intensity 352 nm femtosecond irradiation: Three invented in the mid- 1990s [1]. They represent a periodic change of refractive index in an optical fiber.N. Nikogosyan). Optics Communications 255 (2005) 81­90 www.elsevier.com/locate/optcom #12;recording techniques

  18. 3D Periodic Human Motion Reconstruction from 2D Motion Sequences Zonghua Zhang and Nikolaus F. Troje

    E-Print Network [OSTI]

    Troje, Nikolaus

    1 3D Periodic Human Motion Reconstruction from 2D Motion Sequences Zonghua Zhang and Nikolaus F@psyc.queensu.ca Abstract In this report, we present and evaluate a method of reconstructing three-dimensional (3D) periodic set of 3D data, we construct a linear, morphable representation. Using this representation a low

  19. Pulsive feedback control for stabilizing unstable periodic orbits in a nonlinear oscillator with a non-symmetric potential

    E-Print Network [OSTI]

    G. Litak; M. Ali; L. M. Saha

    2006-01-14T23:59:59.000Z

    We examine a strange chaotic attractor and its unstable periodic orbits in case of one degree of freedom nonlinear oscillator with non symmetric potential. We propose an efficient method of chaos control stabilizing these orbits by a pulsive feedback technique. Discrete set of pulses enable us to transfer the system from one periodic state to another.

  20. A periodic inspection and replacement policy for systems subject to competing failure modes due to degradation and traumatic events

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A periodic inspection and replacement policy for systems subject to competing failure modes due-making. A condition-based periodic inspection/replacement policy is developed and compared with a benchmark time- based block replacement policy. Numerical results show that it is indeed useful to follow closely

  1. Considering the Case for Biodiversity Cycles: Re-Examining the Evidence for Periodicity in the Fossil Record

    E-Print Network [OSTI]

    Lieberman, Bruce S.; Melott, Adrian L.

    2007-04-01T23:59:59.000Z

    that the artifact may ultimately be based on a signal in the data. A 62 Myr feature appears in extinction, when this same procedure is used. We conclude that evidence for a periodicity at 62 Myr is robust, and evidence for periodicity at approximately 27 Myr is also...

  2. X-RAY PROPERTIES OF PREMAIN-SEQUENCE STARS IN THE ORION NEBULA CLUSTER WITH KNOWN ROTATION PERIODS

    E-Print Network [OSTI]

    Barsony, Mary

    X-RAY PROPERTIES OF PRE­MAIN-SEQUENCE STARS IN THE ORION NEBULA CLUSTER WITH KNOWN ROTATION PERIODS Nebula Cluster (ONC) to study the X-ray properties of a large sample of pre­main-sequence (PMS) stars with optically determined rotation periods. Our goal is to elucidate the origins of X-rays in PMS stars

  3. 24 m meteorological tower data report period: January through December, 1996

    SciTech Connect (OSTI)

    Freeman, D.; Bowen, J.; Egami, R.; Coulombe, W.; Crow, D.; Cristani, B.; Schmidt, S.

    1997-12-01T23:59:59.000Z

    This report was prepared by the Desert Research Institute (DRI) for the US Department of Energy (DOE). It summarizes meteorological data collected at the 24 meter tower at the Nevada Test Site Hazardous Material Spill Center (HAZMAT) located at Frenchman Flat near Mercury, Nevada, approximately 75 miles northwest of Las Vegas, Nevada. The tower was originally installed in July, 1993 to characterize baseline conditions for an EPA sponsored experimental research program at the HAZMAT. This report presents results of the monitoring for January--December, 1996, providing: a status of the measurement systems during the report period and a summary of the meteorological conditions at the HAZMAT during the report period. The scope of the report is limited to summary data analyses and does not include extensive meteorological analysis. The tower was instrumented at 8 levels. Wind speed, wind direction, and temperature were measured at all 8 levels. Relative humidity was measured at 3 levels. Solar and net radiation were measured at 2 meters above the ground. Barometric pressure was measured at the base of the tower and soil temperature was measured near the base of the tower.

  4. Dependence of magnetic cycle parameters on period of rotation in nonlinear solar-type dynamos

    E-Print Network [OSTI]

    Pipin, V V

    2014-01-01T23:59:59.000Z

    The paper reports results of calculations of the magnetic cycle parameters, like the dynamo cycle period, amplitude of the magnetic flux and the Poynting flux from the surface for the solar analogs with rotation periods from 15 to 30 days. We employ the nonlinear mean-field axisymmetric dynamo models, which take into account the prin- cipal mechanisms of the nonlinear dynamo saturation. The study takes into account the magnetic helicity conservation, the magnetic buoyancy and the magnetic feedback on the angular momentum balance inside the convection zone. Also, we consider two types of the dynamo models. The D-type models employ the standard {\\alpha}- effect dis- tributed on the whole convection zone. The BL-type models employ the non-local {\\alpha}- effect. Both the D- and BL - types of the dynamo models show the growth of the dynamo generated magnetic flux with the increase of the rotation rate. The magnetic helicity conservation is the most feasible effect for the dynamo saturation both for the D and BL-t...

  5. MHD Simulations of Accretion onto Sgr A*: Quiescent Fluctuations, Outbursts, and Quasi-Periodicity

    E-Print Network [OSTI]

    Chi-kwan Chan; Siming Liu; Christopher L. Fryer; Dimitrios Psaltis; Feryal Ozel; Gabriel Rockefeller; Fulvio Melia

    2006-11-08T23:59:59.000Z

    High resolution observations of Sgr A* have revealed a wide variety of phenomena, ranging from intense rapid flares to quasi-periodic oscillations, making this object an ideal system to study the properties of low luminosity accreting black holes. In this paper, we use a pseudo-spectral algorithm to construct and evolve a three-dimensional magnetohydrodynamic model of the accretion disk in Sgr A*. Assuming a hybrid thermal-nonthermal emission scheme, we show that the MHD turbulence can by itself only produce factor of two fluctuations in luminosity. These amplitudes in variation cannot explain the magnitude of flares observed in this system. However, we also demonstrate that density perturbations in the disk do produce outbursts qualitatively similar to those observed by XMM-Newton in X-rays and ground-based facilities in the near infrared. Quasi-periodic oscillations emerge naturally in the simulated lightcurves. We attribute these to non-axisymmetric density perturbations that emerge as the disk evolves back toward its quiescent state.

  6. EMERGING TRENDS IN A PERIOD-RADIUS DISTRIBUTION OF CLOSE-IN PLANETS

    SciTech Connect (OSTI)

    Beauge, C. [Instituto de Astronomia Teorica y Experimental (IATE), Observatorio Astronomico, Universidad Nacional de Cordoba, Laprida 854, X5000BGR Cordoba (Argentina)] [Instituto de Astronomia Teorica y Experimental (IATE), Observatorio Astronomico, Universidad Nacional de Cordoba, Laprida 854, X5000BGR Cordoba (Argentina); Nesvorny, D. [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)] [Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States)

    2013-01-20T23:59:59.000Z

    We analyze the distribution of extrasolar planets (both confirmed and Kepler candidates) according to their orbital periods P and planetary radii R. Among confirmed planets, we find compelling evidence for a paucity of bodies with 3 R {sub Circled-Plus} < R < 10 R {sub Circled-Plus }, where R {sub Circled-Plus} is Earth's radius and P < 2-3 days. We have christened this region a sub-Jovian Pampas. The same trend is detected in multiplanet Kepler candidates. Although approximately 16 Kepler single-planet candidates inhabit this Pampas, at least 7 are probable false positives (FPs). This last number could be significantly higher if the ratio of FPs is higher than 10%, as suggested by recent studies. In a second part of the paper we analyze the distribution of planets in the (P, R) plane according to stellar metallicities. We find two interesting trends: (1) a lack of small planets (R < 4 R {sub Circled-Plus }) with orbital periods P < 5 days in metal-poor stars and (2) a paucity of sub-Jovian planets (4 R {sub Circled-Plus} < R < 8 R {sub Circled-Plus }) with P < 100 days, also around metal-poor stars. Although all these trends are preliminary, they appear statistically significant and deserve further scrutiny. If confirmed, they could represent important constraints on theories of planetary formation and dynamical evolution.

  7. Gravitational Shapiro Telescope on the PSR's period to discover Dark Planets and Machos

    E-Print Network [OSTI]

    D. Fargion; R. Conversano

    2001-06-13T23:59:59.000Z

    Collective Shapiro Phase Shift on the period of the pulsars due to a dark object (a passing MACHO or a planet) along the line-of-sight of one or more pulsar is a formidable gravitational tool to discover dark matter.We already noted that the presence of a few negative PSRs period, possibly due to such a Shapiro delay, is roughly consistent with independent estimates of MACHOs observed by microlensing in our Galaxy. Here we update our study and suggest to verify and to calibrate the Shapiro phase delay to observe on ecliptic main known planetary and solar gravitational fields. Once the test is probed we propose to use, in a collective way, a subsample of PSRs on the ecliptic plane to monitor our solar system for discovering any heavy unknown object, either dark Macho or planets. The importance of such unknown possible planetary components and their eventual near encounter with Earth in the far past (or future) should be not neglected : the same life evolution (or extinction) might be marked by such a rare event.

  8. 24 m meteorological tower data report period: January through December, 1995

    SciTech Connect (OSTI)

    Freeman, D.; Bowen, J.B.; Egami, R.; Coulombe, W.; Crow, D.; Cristani, B.; Schmidt, S.

    1997-12-01T23:59:59.000Z

    This report was prepared by the Desert Research Institute (DRI) for the US Department of Energy (DOE). It summarizes meteorological data collected at the 24 meter tower at the Nevada Test Site Hazardous Material Spill Center (HAZMAT) located at Frenchman Flat near Mercury, Nevada, approximately 75 miles northwest of Las Vegas, Nevada. The tower was originally installed in July, 1993 to characterize baseline conditions for an EPA sponsored experimental research program at the HAZMAT. A previous report reported monitoring results for 1994. This report presents results of the monitoring for January--December, 1995, providing: a status of the measurement systems (including any quality assurance activities) during the report period and a summary of the meteorological conditions at the HAZMAT during the report period. The scope of the report is limited to summary data analyses and does not include extensive meteorological analysis. The tower was instrumented at 8 levels. Wind speed, wind direction, and temperature were measured at all 8 levels. Relative humidity was measured at 3 levels. Solar and net radiation were measured at 2 meters above the ground. Barometric pressure was measured at the base of the tower and soil temperature was measured near the base of the tower.

  9. Quasiperiodic Dynamics in Bose-Einstein Condensates in Periodic Lattices and Superlattices

    E-Print Network [OSTI]

    Martijn van Noort; Mason A. Porter; Yingfei Yi; Shui-Nee Chow

    2006-09-18T23:59:59.000Z

    We employ KAM theory to rigorously investigate quasiperiodic dynamics in cigar-shaped Bose-Einstein condensates (BEC) in periodic lattices and superlattices. Toward this end, we apply a coherent structure ansatz to the Gross-Pitaevskii equation to obtain a parametrically forced Duffing equation describing the spatial dynamics of the condensate. For shallow-well, intermediate-well, and deep-well potentials, we find KAM tori and Aubry-Mather sets to prove that one obtains mostly quasiperiodic dynamics for condensate wave functions of sufficiently large amplitude, where the minimal amplitude depends on the experimentally adjustable BEC parameters. We show that this threshold scales with the square root of the inverse of the two-body scattering length, whereas the rotation number of tori above this threshold is proportional to the amplitude. As a consequence, one obtains the same dynamical picture for lattices of all depths, as an increase in depth essentially only affects scaling in phase space. Our approach is applicable to periodic superlattices with an arbitrary number of rationally dependent wave numbers.

  10. Quasilocal conservation laws in XXZ spin-1/2 chains: open, periodic and twisted boundary conditions

    E-Print Network [OSTI]

    Tomaz Prosen

    2014-08-05T23:59:59.000Z

    A continuous family of quasilocal exact conservation laws is constructed in the anisotropic Heisenberg (XXZ) spin-1/2 chain for periodic (or twisted) boundary conditions and for a set of commensurate anisotropies densely covering the entire easy plane interaction regime. All local conserved operators follow from the standard (Hermitian) transfer operator in fundamental representation (with auxiliary spin s=1/2), and are all even with respect to a spin flip operation. However, the quasilocal family is generated by differentiation of a non-Hermitian highest weight transfer operator with respect to a complex auxiliary spin representation parameter s and includes also operators of odd parity. For a finite chain with open boundaries the time derivatives of quasilocal operators are not strictly vanishing but result in operators localized near the boundaries of the chain. We show that a simple modification of the non-Hermitian transfer operator results in exactly conserved, but still quasilocal operators for periodic or generally twisted boundary conditions. As an application, we demonstrate that implementing the new exactly conserved operator family for estimating the high-temperature spin Drude weight results, in the thermodynamic limit, in exactly the same lower bound as for almost conserved family and open boundaries. Under the assumption that the bound is saturating (suggested by agreement with previous thermodynamic Bethe ansatz calculations) we propose a simple explicit construction of infinite time averages of local operators such as the spin current.

  11. Brittle fracture in a periodic structure with internal potential energy. Quasi-static analysis

    E-Print Network [OSTI]

    Mishuris, Gennady S

    2013-01-01T23:59:59.000Z

    We consider a linearly elastic body consisting of two equal symmetrically arranged layers (or half-planes) connected by a structured interface as a prospective crack path. The interface is comprised by periodic discrete system of bonds. In the initial state with no external forces, the bonds are assumed to be stressed in such a way that tensile and compressive forces of the same value alternate. In the general considerations, the layers are assumed to be of a general, unspecified {\\em periodic} structure, where such self-equilibrated residual stresses can also exist. A two-line chain and an anisotropic lattice are examined as illustrative examples. We consider the states of the body-with-a-crack under the residual stresses and under a combined action of the remote forces and residual stresses. Analytical solutions to the considered problems are presented. The solutions are based on a selective discrete transform introduced. In particular, it is found that a formula for local-to-global energy release ratio, wr...

  12. Response of the Hodgkin-Huxley neuron to a periodic sequence of biphasic pulses

    E-Print Network [OSTI]

    Borkowski, L S

    2013-01-01T23:59:59.000Z

    We study the response of the Hodgkin-Huxley neuron stimulated periodically by biphasic rectangular current pulses. The optimal response for charge-balanced input is obtained for cathodic-first pulses with an inter-phase gap (IPG) approximately equal 5 ms. For short pulses the topology of the global bifurcation diagram in the period-amplitude plane is approximately invariant with respect to the pulse polarity and shape details. If stimuli are delivered at neuron's resonant frequencies the firing rate is a continuous function of pulse amplitude. At nonresonant frequencies the quiescent state and the firing state coexist over a range of amplitude values and the transition to excitability is a discontinuous one. There is a multimodal odd-all transition between the 2:1 and 3:1 locked-in states. A strong antiresonant effect is found between the states 3:1 and 4:1, where the modes (2+3n):1, $n=0,1,2,...$, are entirely absent. At high frequencies the excitation threshold is a nonmonotonic function of the stimulus and...

  13. Statistical Features of the Wind Field over the Indian Ccean for the period 1998-2008

    E-Print Network [OSTI]

    Polnikov, Vladislav; Sannasiraj, S A

    2011-01-01T23:59:59.000Z

    We have done a statistical analysis of the wind field from the archive of NCEP/NOAA over the Indian Ocean for the period 1998-2008yy, which is given on a grid 1x1.25 of latitude-longitude with 3h time-step. Initial analysis includes mapping the average wind fields and fields of mean density of the wind-kinetic-energy flux , obtained with different periods of time averaging T, as well as the assessment of 11-year trends in these fields. The subsequent analysis is concerned with partition of the Indian ocean area into 6 zones, provided by the spatial inhomogeneity of the analyzed wind field. This analysis includes: a) an assessment of temporal variations for the wind speed field averaged over the Ocean and the zones and for the field of wind-energy flux; b) construction of time history series of these fields averaged with different scales, and estimating frequency spectra of these series; c) finding the extremes of the wind field (in the zones of Indian Ocean); d) construction of histograms of the wind field; ...

  14. Brittle fracture in a periodic structure with internal potential energy. Spontaneous crack propagation

    E-Print Network [OSTI]

    Mark Ayzenberg-Stepanenko; Gennady Mishuris; Leonid Slepyan

    2014-02-12T23:59:59.000Z

    Spontaneous brittle fracture is studied based on the recently introduced model (Mishuris and Slepyan, Brittle fracture in a periodic structure with internal potential energy. Proc. Roy. Soc. A, in press). A periodic structure is considered, where only the prospective crack-path layer is specified as a discrete set of alternating initially stretched and compressed bonds. A bridged crack destroying initially stretched bonds may propagate under a certain level of the internal energy without external sources. The general analytical solution with the crack speed $-$ energy relation is presented in terms of the crack-related dynamic Green's function. For the anisotropic two-line chain and lattice considered earlier in quasi-statics, the dynamic problem is examined in detail. The crack speed is found to grow unboundedly as the energy approaches its upper limit. It is revealed that the spontaneous fracture can occur in the form of a pure bridged, partially bridged or fully open crack depending on the internal energy level. Generally, the steady-state mode of the crack propagation is found to be realised, whereas an irregular growth, clustering and the crack speed oscillations are detected in a vicinity of the lower bound of the energy.

  15. Periodic dielectric structure for production of photonic band gap and devices incorporating the same

    DOE Patents [OSTI]

    Ho, Kai-Ming (Ames, IA); Chan, Che-Ting (Ames, IA); Soukoulis, Costas (Ames, IA)

    1994-08-02T23:59:59.000Z

    A periodic dielectric structure which is capable of producing a photonic band gap and which is capable of practical construction. The periodic structure is formed of a plurality of layers, each layer being formed of a plurality of rods separated by a given spacing. The material of the rods contrasts with the material between the rods to have a refractive index contrast of at least two. The rods in each layer are arranged with their axes parallel and at a given spacing. Adjacent layers are rotated by 90.degree., such that the axes of the rods in any given layer are perpendicular to the axes in its neighbor. Alternating layers (that is, successive layers of rods having their axes parallel such as the first and third layers) are offset such that the rods of one are about at the midpoint between the rods of the other. A four-layer periocity is thus produced, and successive layers are stacked to form a three-dimensional structure which exhibits a photonic band gap. By virtue of forming the device in layers of elongate members, it is found that the device is susceptible of practical construction.

  16. Riparian Buffer Project : Annual Report for the Period April 1, 2001 to March 31, 2002.

    SciTech Connect (OSTI)

    Wasco County Soil and Water Conservation District

    2002-01-01T23:59:59.000Z

    This project implements riparian buffer systems in the Mid-Columbia, addressing limiting factors identified in the Fifteen mile Subbasin Summary, June 30, 2000. The project is providing the technical planning support needed to implement at least 36 riparian buffer system contracts on approximately 872 acres covering an estimated 40 miles of anadromous fish streams over a three year period. In the first year of implementation, 26 buffer contracts were established on 25-26 miles of stream. This nearly doubled the annual goal. Buffer widths averaged 83 ft. on each side of the stream. Implementation included prescribed plantings, fencing, and related practices. Actual implementation costs, lease payments, and maintenance costs are borne by existing USDA programs: Conservation Reserve and Conservation Reserve Enhancement Programs. The lease period of each contract may vary between 10 to 15 years. During this year the average was 14.5 years. The total value of contracts established this year is $1,491,235 compared with $64,756 in BPA contract costs to provide the technical support needed to get the contracts implemented. This project provides technical staffing to conduct assessments and develop plans to help keep pace with the growing backlog of potential riparian buffer projects. Word of mouth from satisfied customers has brought in many new sign-ups during the year. More than half of the contracts this year have been done in the Hood and Fifteen mile sub-basins with additional contracts in adjacent sub-basins.

  17. All-sky search for periodic gravitational waves in LIGO S4 data

    E-Print Network [OSTI]

    Abbott, B; Adhikari, R; Agresti, J; Ajith, P; Allen, B; Amin, R; Anderson, S B; Anderson, W G; Arain, M; Araya, M; Armandula, H; Ashley, M; Aston, S; Aufmuth, P; Aulbert, C; Babak, S; Ballmer, S; Bantilan, H; Barish, B C; Barker, C; Barker, D; Barr, B; Barriga, P; Barton, M A; Bayer, K; Belczynski, K; Betzwieser, J; Beyersdorf, P T; Bhawal, B; Bilenko, I A; Billingsley, G; Biswas, R; Black, E; Blackburn, K; Blackburn, L; Blair, D; Bland, B; Bogenstahl, J; Bogue, L; Bork, R; Boschi, V; Bose, S; Brady, P R; Braginsky, V B; Brau, J E; Brinkmann, M; Brooks, A; Brown, D A; Bullington, A; Bunkowski, A; Buonanno, A; Burmeister, O; Busby, D; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cannizzo, J; Cannon, K; Cantley, C A; Cao, J; Cardenas, L; Casey, M M; Castaldi, G; Cepeda, C; Chalkey, E; Charlton, P; Chatterji, S; Chelkowski, S; Chen, Y; Chiadini, F; Chin, D; Chin, E; Chow, J; Christensen, N; Clark, J; Cochrane, P; Cokelaer, T; Colacino, C N; Coldwell, R; Conte, R; Cook, D; Corbitt, T; Coward, D; Coyne, D; Creighton, J D E; Creighton, T D; Croce, R P; Crooks, D R M; Cruise, A M; Cumming, A; Dalrymple, J; D'Ambrosio, E; Danzmann, K; Davies, G; De Bra, D; Degallaix, J; Degree, M; Demma, T; Dergachev, V; Desai, S; DeSalvo, R; Dhurandhar, S; Daz, M; Dickson, J; Di Credico, A; Diederichs, G; Dietz, A; Doomes, E E; Drever, R W P; Dumas, J C; Dupuis, R J; Dwyer, J G; Ehrens, P; Espinoza, E; Etzel, T; Evans, M; Evans, T; Fairhurst, S; Fan, Y; Fazi, D; Fejer, M M; Finn, L S; Fiumara, V; Fotopoulos, N; Franzen, A; Franzen, K Y; Freise, A; Frey, R; Fricke, T; Fritschel, P; Frolov, V V; Fyffe, M; Galdi, V; Garofoli, J; Gholami, I; Giaime, J A; Giampanis, S; Giardina, K D; Goda, K; Goetz, E; Goggin, L M; Gonzlez, G; Gossler, S; Grant, A; Gras, S; Gray, a C; Gray, M; Greenhalgh, J; Gretarsson, A M; Grosso, R; Grote, H; Grnewald, S; Gnther, M; Gustafson, R; Hage, B; Hammer, D; Hanna, C; Hanson, J; Harms, J; Harry, G; Harstad, E; Hayler, T; Heefner, J; Heng, I S; Heptonstall, A; Heurs, M; Hewitson, M; Hild, S; Hirose, E; Hoak, D; Hosken, D; Hough, J; Howell, E; Hoyland, D; Huttner, S H; Ingram, D; Innerhofer, E; Ito, M; Itoh, Y; Ivanov, A; Jackrel, D; Johnson, B; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, Peter Ignaz Paul; Kalogera, V; Kasprzyk, D; Katsavounidis, E; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Khalili, F Ya; Kim, C; King, P; Kissel, J S; Klimenko, S; Kokeyama, K; Kondrashov, V; Kopparapu, R K; Kozak, D; Krishnan, B; Kwee, P; Lam, P K; Landry, M; Lantz, B; Lazzarini, A; Lee, B; Lei, M; Leiner, J; Leonhardt, V; Leonor, I; Libbrecht, K; Lindquist, P; Lockerbie, N A; Longo, M; Lormand, M; Lubinski, M; Luck, H; Machenschalk, B; MacInnis, M; Mageswaran, M; Mailand, K; Malec, M; Mandic, V; Marano, S; Marka, S; Markowitz, J; Maros, E; Martin, I; Marx, J N; Mason, K; Matone, L; Matta, V; Mavalvala, a N; McCarthy, R; McClelland, D E; McGuire, S C; McHugh, M; McKenzie, K; McNabb, J W C; McWilliams, S; Meier, T; Melissinos, A; Mendell, G; Mercer, R A; Meshkov, S; Messaritaki, E; Messenger, C J; Meyers, D; Mikhailov, E; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Miyakawa, O; Mohanty, S; Moreno, G; Mossavi, K; Mow Lowry, C; Moylan, A; Mudge, D; Mller, G; Mukherjee, S; Muller-Ebhardt, H; Munch, J; Murray, P; Myers, E; Myers, J; Nash, T; Newton, G; Nishizawa, A; Numata, K; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Overmier, H; Owen, B J; Pan, Y; Papa, M A; Parameshwaraiah, V; Patel, P; Pedraza, M; Penn, S; Pierro, V; Pinto, I M; Pitkin, M; Pletsch, H; Plissi, M V; Postiglione, F; Prix, R; Quetschke, V; Raab, F; Rabeling, D; Radkins, H; Rahkola, R; Rainer, N; Rakhmanov, M; Ramsunder, M; Rawlins, K; Ray-Majumder, S; Re, V; Rehbein, H; Reid, S; Reitze, D H; Ribichini, L; Riesen, R; Riles, K; Rivera, B; Robertson, N A; Robinson, C; Robinson, E L; Roddy, S; Rodrguez, A; Rogan, A M; Rollins, J; Romano, J D; Romie, J; Route, R; Rowan, S; Rdiger, A; Ruet, L; Russell, P; Ryan, K; Sakata, S; Samidi, M; Sancho de la Jordana, L; Sandberg, V; Sannibale, V; Saraf, S; Sarin, P; Sathyaprakash, B S; Sato, S; Saulson, P R; Savage, R; Savov, P; Schediwy, S; Schilling, R; Schnabel, R; Schofield, R; Schutz, B F; Schwinberg, P; Scott, S M; Searle, A C; Sears, B; Seifert, F; Sellers, D; Sengupta, A S; Shawhan, P; Shoemaker, D H; Sibley, A; Sidles, J A; Siemens, X; Sigg, D; Sinha, S; Sintes, A M; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M R; Somiya, K; Strain, K A; Strom, D M; Stuver, A; Summerscales, T Z; Sun, K X; Sung, M; Sutton, P J; Takahashi, H; Tanner, D B; Tarallo, M; Taylor, R; Taylor, R; Thacker, J; Thorne, K A; Thorne, K S; Thring, A; Tokmakov, K V; Torres, C; Torrie, C; Traylor, G; Trias, M; Tyler, W; Ugolini, D; Ungarelli, C; Urbanek, K; Vahlbruch, H; Vallisneri, M; Van Den Broeck, C; Varvella, M; Vass, S; Vecchio, A; Veitch, J; Veitch, P; Villar, A; Vorvick, C

    2007-01-01T23:59:59.000Z

    We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1000 Hz and with the frequency's time derivative in the range -1.0E-8 Hz/s to zero. Data from the fourth LIGO science run (S4) have been used in this search. Three different semi-coherent methods of transforming and summing strain power from Short Fourier Transforms (SFTs) of the calibrated data have been used. The first, known as "StackSlide", averages normalized power from each SFT. A "weighted Hough" scheme is also developed and used, and which also allows for a multi-interferometer search. The third method, known as "PowerFlux", is a variant of the StackSlide method in which the power is weighted before summing. In both the weighted Hough and PowerFlux methods, the weights are chosen according to the noise and detector antenna-pattern to maximize the signal-to-noise ratio. The respective advantages and disadvantages of these methods are discussed. Observing no evidence of periodic gravitationa...

  18. Analytical Chemistry Division annual progress report for period ending December 31, 1982

    SciTech Connect (OSTI)

    Lyon, W.S. (ed.)

    1983-05-01T23:59:59.000Z

    The Analytical Chemistry Dvision of Oak Ridge National laboratory (ORNL) serves a multitude of functions for a clientele that exists both in and outside ORNL. These functions fall into the following general categories: (1) analytical research, development, and implementation; (2) programmatic research, development, and utilization; and (3) technical support. The Division is organized into five major sections, each of which may carry out any type of work falling in the three categories mentioned above. Chapters 1 through 5 of this report highlight progress within the five sections (analytical methodology, mass and emission spectrometry, radioactive materials, bio/organic analysis, and general and environmental analysis) during the period January 1, 1982 to December 31, 1982. A short summary introduces each chapter to indicate work scope. Information about quality assurance and safety programs is presented in Chapter 6, along with a tabulation of analyses rendered. Publications, oral presentations, professional activities, educational programs, and seminars are cited in Chapters 7 and 8. Approximately 61 articles, 32 proceedings publications and 37 reports have been published, and 107 oral presentations were given during this reporting period.

  19. Variation of the Light and Period of the Magnetic Cataclysmic Variable Am Her

    E-Print Network [OSTI]

    Belinda Kalomeni; Kadri Yakut

    2008-11-04T23:59:59.000Z

    Ground-based long-term optic variability of AM Her, covering the period between 2003-2008, has been conducted to study the features seen in both low and high states of the system. Low-state analysis shows the presence of short-term, low-amplitude light variations of about 0.02-0.03 mag with a mean power time between 16 s and 226 s. Brightness variations on the order of 0.7--2 mag, which could be due to the stellar activity of the component in the system, are also detected. A total of 30 years times of minimum light given in the literature are combined with nine times of minima obtained in this study. We represented the (observed--calculated) diagram by a parabolic curve and also by two broken lines. Under the assumption of a parabolic variation, we estimate an increase in period, dP/dt=7.5(1.2)x10^{-9} days yr^{-1}, with a mass transfer rate of dM/dt = 8(2)x10^{-9} M_{\\odot} yr^{-1}, in agreement with the previous findings by a different method.

  20. CONSIDERATIONS IN THE DESIGN OF UNDULATORS L. C. Teng A. Relevant Radiation Formulas

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites Proposed Route BTRICGEGR-N Goods PO 1 of 8 GE

  1. Proposed dielectric-based microstructure laser-driven undulator T. Plettner and R. L. Byer

    E-Print Network [OSTI]

    Byer, Robert L.

    by the possibility of future dielectric-based laser-driven particle accelerators that are expected to produce GeV=m accel- eration gradients accompanied by a low-emittance, low- energy spread, and high-repetition rate electron sources [8,9] as well as for dielectric-structure laser-driven particle accelerators are underway

  2. Design of Control Instrumentation of a 4 meter Variable Polarization Undulator (EPU)

    SciTech Connect (OSTI)

    Kulesza, Joe; Deyhim, Alex [Advanced Design Consulting USA, 126 Ridge Road, P.O. Box 187, Lansing, NY 14882 (United States); Fan Taiching; Chen, Jenny [National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Science-Based Industrial Park, Hsinchu 30077, Taiwan (China)

    2007-01-19T23:59:59.000Z

    The design of a high end, very sophisticated controller, that consists of an Allen Bradley ControlLogix PLC with a Kinetix servo controller for a 4.16 m EPU is presented. Four servo motors control the gap - 2 on the upper girder and 2 on the lower girder, and another 4 servos controls the phase - 2 on the upper girder inner and outer and 2 on the lower girder, inner and outer. This system is designed for The Taiwan Light Source (TLS) a synchrotron radiation machine of the National Synchrotron Radiation Research Center (NSRRC) at the energy of 1.5 GeV with electron beam current of 200 {approx} 400 mA.

  3. Delta undulator test result and specific of a small bore insertion device magnetic field measurement*.

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to UserProduct: CrudeOffice ofINLNuclear Security |CreatingAorn ofDelta

  4. The evolution of the radiation field in an FEL undulator is governed by the following equation:

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2 andThe MolecularPlaceTheof carbonbiogenic U(IV).3 A

  5. On-Axis Brilliance and Power of In-Vacuum Undulators for The Advanced Photon Source

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 The 2002 WholesaleEnergy's 1000 acres of landJuneEMSL On the4

  6. ANL/APS/TB-1 APS Undulator and Wiggler Sources: Monte-Carlo Simulation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations2 Print258Department of3

  7. ANL/APS/TB-24 Diamond Monochromators for APS Undulator-A Beamlines

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNGExperience4AJ01) (See95TI07)Operations2 Print258Department of31 . Wiggler9 A4

  8. UNDULATOR TUNABILITY AND RING-ENERGY P. J. Viccaro and G. K. Shenoy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof EnergyLeaseEnergyUNCLASSIFIED 2 1 2 : 0

  9. ISSUANCE 2015-01-26: Energy Conservation Program: Energy Conservation Standards for High-Intensity Lamps, Notice to Reopen Comment Period

    Broader source: Energy.gov [DOE]

    Energy Conservation Program: Energy Conservation Standards for High-Intensity Lamps, Notice to Reopen Comment Period

  10. Quarterly report of RCRA groundwater monitoring data for period January 1--March 31, 1995

    SciTech Connect (OSTI)

    NONE

    1995-07-01T23:59:59.000Z

    This quarterly report contains data received between January and March 1995, which are the cutoff dates for this reporting period. This report may contain not only data from the January through March quarter, but also data from earlier sampling events that were not previously reported. Nineteen Resource Conservation and Recovery Act of 1976 (RCRA) groundwater monitoring projects are conducted at the Hanford Site. These projects include treatment, storage, and disposal facilities for both solid and liquid waste. The groundwater monitoring programs described in this report comply with the interim-status federal (Title 40 Code of Federal Regulation [CFR] Part 265) and state (Washington Administrative Code [WAC] 173-303-400) regulations. The RCRA projects are monitored under one of three programs: background monitoring, indicator parameter evaluation, or groundwater quality assessment.

  11. Spectral Pollution and How to Avoid It (With Applications to Dirac and Periodic Schrdinger Operators)

    E-Print Network [OSTI]

    Mathieu Lewin; Eric Sr

    2008-12-11T23:59:59.000Z

    This paper, devoted to the study of spectral pollution, contains both abstract results and applications to some self-adjoint operators with a gap in their essential spectrum occuring in Quantum Mechanics. First we consider Galerkin basis which respect the decomposition of the ambient Hilbert space into a direct sum $H=PH\\oplus(1-P)H$, given by a fixed orthogonal projector $P$, and we localize the polluted spectrum exactly. This is followed by applications to periodic Schr\\"odinger operators (pollution is absent in a Wannier-type basis), and to Dirac operator (several natural decompositions are considered). In the second part, we add the constraint that within the Galerkin basis there is a certain relation between vectors in $PH$ and vectors in $(1-P)H$. Abstract results are proved and applied to several practical methods like the famous "kinetic balance" of relativistic Quantum Mechanics.

  12. Engineering Physics and Mathematics Division progress report for period ending March 31, 1991

    SciTech Connect (OSTI)

    Not Available

    1991-10-01T23:59:59.000Z

    The primary purpose of this report is to provide an archival record of the activities of the Engineering Physics and Mathematics Division during the period September 1, 1989 through March 31, 1991. Earlier reports in this series are identified on the previous pages, along with the progress reports describing ORNL's research on the mathematical sciences prior to 1984 when those activities moved into the division. As in previous reports, our research is described through abstracts of journal articles, technical reports, and presentations. Summary lists of publications and presentations, staff additions and departures, scientific and professional activities of division staff, and technical conferences organized and sponsored by the division are included as appendices. The report is organized following the division of our research among four sections and information centers. These research areas are: Mathematical Sciences; Nuclear Data Measurement and Evaluations; Intelligent Systems; Nuclear Analysis and Shielding; and Engineering Physics Information Center.

  13. Periodic alignment of Si quantum dots on hafnium oxide coated single wall carbon nanotubes

    SciTech Connect (OSTI)

    Olmedo, Mario; Martinez-Morales, Alfredo A.; Ozkan, Mihrimah; Liu Jianlin [Department of Electrical Engineering, University of California, Riverside, California 92521 (United States); Liu Gang; Lau, C.N. [Department of Physics and Astronomy, University of California, Riverside, California 92521 (United States); Yengel, Emre; Ozkan, Cengiz S. [Department of Mechanical Engineering, University of California, Riverside, California 92521 (United States)

    2009-03-23T23:59:59.000Z

    We demonstrate a bottom up approach for the aligned epitaxial growth of Si quantum dots (QDs) on one-dimensional (1D) hafnium oxide (HfO{sub 2}) ridges created by the growth of HfO{sub 2} thin film on single wall carbon nanotubes. This growth process creates a high strain 1D ridge on the HfO{sub 2} film, which favors the formation of Si seeds over the surrounding flat HfO{sub 2} area. Periodic alignment of Si QDs on the 1D HfO{sub 2} ridge was observed, which can be controlled by varying different growth conditions, such as growth temperature, growth time, and disilane flow rate.

  14. H-band thermal emission from the 0.79-day period planet WASP-19b

    E-Print Network [OSTI]

    Anderson, D R; Maxted, P F L; Barman, T S; Cameron, A Collier; Hellier, C; Queloz, D; Smalley, B; Triaud, A H M J

    2010-01-01T23:59:59.000Z

    We present the first ground-based detection of thermal emission from an exoplanet in the H-band. Using HAWK-I on the VLT, we observed an occultation of WASP-19b by its G8V-type host star. WASP-19b is a Jupiter-mass planet with an orbital period of only 0.79 d, and thus, being highly irradiated, is expected to be hot. We measure an H-band occultation depth of (0.259 +0.046 -0.044) %. A cloud-free model of the planet's atmosphere, with no redistribution of energy from day-side to night-side, under-predicts the planet/star flux density ratio by a factor of two. As the stellar parameters, and thus the level of planetary irradiation, are well-constrained by measurement, it is likely that our model of the planet's atmosphere is too simple.

  15. Periodic and chaotic oscillations in a tumor and immune system interaction model with three delays

    SciTech Connect (OSTI)

    Bi, Ping [Department of Mathematics, Shanghai Key Laboratory of PMMP, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China) [Department of Mathematics, Shanghai Key Laboratory of PMMP, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Center for Partial Differential Equations, East China Normal University, 500 Dongchuan Rd., Shanghai 200241 (China); Ruan, Shigui, E-mail: ruan@math.miami.edu [Department of Mathematics, University of Miami, Coral Gables, Florida 33124-4250 (United States)] [Department of Mathematics, University of Miami, Coral Gables, Florida 33124-4250 (United States); Zhang, Xinan [School of Mathematics and Statistics, Central China Normal University, Wuhan 430079 (China)] [School of Mathematics and Statistics, Central China Normal University, Wuhan 430079 (China)

    2014-06-15T23:59:59.000Z

    In this paper, a tumor and immune system interaction model consisted of two differential equations with three time delays is considered in which the delays describe the proliferation of tumor cells, the process of effector cells growth stimulated by tumor cells, and the differentiation of immune effector cells, respectively. Conditions for the asymptotic stability of equilibria and existence of Hopf bifurcations are obtained by analyzing the roots of a second degree exponential polynomial characteristic equation with delay dependent coefficients. It is shown that the positive equilibrium is asymptotically stable if all three delays are less than their corresponding critical values and Hopf bifurcations occur if any one of these delays passes through its critical value. Numerical simulations are carried out to illustrate the rich dynamical behavior of the model with different delay values including the existence of regular and irregular long periodic oscillations.

  16. High field pulsed microwiggler comprising a conductive tube with periodically space slots

    DOE Patents [OSTI]

    Warren, R.W.

    1992-09-01T23:59:59.000Z

    A microwiggler assembly produces large magnetic fields for oscillating charged particle beams, particularly electron beams for free electron laser (FEL) application. A tube of electrically conductive material is formed with radial slots axially spaced at the period of the electron beam. The slots have alternate 180[degree] relationships and are formed to a maximum depth of 0.6 to 0.7 times the tube circumference. An optimum slot depth is selected to eliminate magnetic quadrupole fields within the microwiggler as determined from a conventional pulsed wire technique. Suitable slot configurations include single slits, double slits, triple slits, and elliptical slots. An axial electron beam direction is maintained by experimentally placing end slits adjacent entrance and exit portions of the assembly, where the end slit depth is determined by use of the pulsed wire technique outside the tube. 10 figs.

  17. Maximum likelihood method for estimating the mass and period distributions of extra-solar planets

    E-Print Network [OSTI]

    Serge Tabachnik; Scott Tremaine

    2001-10-22T23:59:59.000Z

    We investigate the distribution of mass M and orbital period P of extra-solar planets, taking account of selection effects due to the limited velocity precision and duration of existing surveys. We fit the data on 63 planets to a power-law distribution of the form dn=CM^{-alpha}P^{-beta}(dM/M)(dP/P), and find alpha=0.12+-0.10, beta=-0.26+-0.06 for M<10M_J, where M_J is the Jupiter mass. The correlation coefficient between these two exponents is -0.32, indicating that uncertainties in the two distributions are coupled. We estimate that 3% of solar-type stars have companions in the range 1M_J

  18. The periodic standing-wave approximation: computations in full general relativity

    E-Print Network [OSTI]

    Napoleon Hernandez; Richard H. Price

    2008-12-23T23:59:59.000Z

    The periodic standing wave method studies circular orbits of compact objects coupled to helically symmetric standing wave gravitational fields. From this solution an approximation is extracted for the strong field, slowly inspiralling motion of binary black holes and binary neutron stars. Previous work on this project has developed a method using a few multipoles of specially adapted coordinates well suited both to the radiation and the source regions. This method had previously been applied to linear and nonlinear scalar field models, to linearized gravity, and to a post-Minkowski approximation. Here we present the culmination of this approach: the application of the method in full general relativity. The fundamental equations had previously been developed and the challenge presented by this step is primarily a computational one which was approached with an innovative technique. The numerical results of these computations are compared with the corresponding results from linearized and post-Minkowksi computations.

  19. Attractiveness of periodic orbits in parametrically forced systemswith time-increasing friction

    E-Print Network [OSTI]

    Michele Bartuccelli; Jonathan Deane; Guido Gentile

    2012-07-18T23:59:59.000Z

    We consider dissipative one-dimensional systems subject to a periodic force and study numerically how a time-varying friction affects the dynamics. As a model system, particularly suited for numerical analysis, we investigate the driven cubic oscillator in the presence of friction. We find that, if the damping coefficient increases in time up to a final constant value, then the basins of attraction of the leading resonances are larger than they would have been if the coefficient had been fixed at that value since the beginning. From a quantitative point of view, the scenario depends both on the final value and the growth rate of the damping coefficient. The relevance of the results for the spin-orbit model are discussed in some detail.

  20. Internal Space-time Symmetries of Particles derivable from Periodic Systems in Optics

    E-Print Network [OSTI]

    Y. S. Kim

    2010-09-26T23:59:59.000Z

    While modern optics is largely a physics of harmonic oscillators and two-by-two matrices, it is possible to learn about some hidden properties of the two-by-two matrix from optical systems. Since two-by-two matrices can be divided into three conjugate classes depending on their traces, optical systems force us to establish continuity from one class to another. It is noted that those three classes are equivalent to three different branches of Wigner's little groups dictating the internal space-time symmetries massive, massless, and imaginary-mass particles. It is shown that the periodic systems in optics can also be described by have the same class-based matrix algebra. The optical system allow us to make continuous, but not analytic, transitions from massiv to massless, and massless to imaginary-mass cases.