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Sample records for times lisa wiecki

  1. Synthetic LISA: Simulating time delay interferometry in a model LISA

    International Nuclear Information System (INIS)

    Vallisneri, Michele

    2005-01-01

    We report on three numerical experiments on the implementation of Time-Delay Interferometry (TDI) for LISA, performed with Synthetic LISA, a C++/Python package that we developed to simulate the LISA science process at the level of scientific and technical requirements. Specifically, we study the laser-noise residuals left by first-generation TDI when the LISA armlengths have a realistic time dependence; we characterize the armlength-measurement accuracies that are needed to have effective laser-noise cancellation in both first- and second-generation TDI; and we estimate the quantization and telemetry bitdepth needed for the phase measurements. Synthetic LISA generates synthetic time series of the LISA fundamental noises, as filtered through all the TDI observables; it also provides a streamlined module to compute the TDI responses to gravitational waves according to a full model of TDI, including the motion of the LISA array and the temporal and directional dependence of the armlengths. We discuss the theoretical model that underlies the simulation, its implementation, and its use in future investigations on system-characterization and data-analysis prototyping for LISA

  2. Time-delay interferometry for LISA

    International Nuclear Information System (INIS)

    Tinto, Massimo; Estabrook, F.B.; Armstrong, J.W.

    2002-01-01

    LISA (Laser Interferometer Space Antenna) is a mission to detect and study low-frequency cosmic gravitational radiation through its influence on the phases or frequencies of laser beams exchanged between three remote spacecraft. We previously showed how, with lasers of identical frequencies on stationary spacecraft, the measurement of twelve time series of Doppler shifts could be combined to cancel exactly the phase noise of the lasers and the Doppler fluctuations due to noninertial motions of the six optical benches, while preserving gravitational wave signals. Here we generalize those results on gravitational wave detection with time-delay interferometry to the expected LISA instrument. The six lasers have different center frequencies (in the nominal LISA configuration these center frequencies may well differ by several hundred megahertz) and the distances between spacecraft pairs will change with time (these slowly varying orbital Doppler shifts are expected to be up to tens of megahertz). We develop time-delay data combinations which, as previously, preserve gravitational waves and exactly cancel the leading noise source (phase fluctuations of the six lasers); these data combinations then imply transfer functions for the remaining system noises. Using these, we plot frequency and phase power spectra for modeled system noises in the unequal Michelson combination X and the symmetric Sagnac combination ζ. Although optical bench noise can no longer be cancelled exactly, with the current LISA specifications it is suppressed to negligible levels. It is known that the presently anticipated laser center frequency differences and the orbital Doppler drifts introduce another source of phase noise, arising from the onboard oscillators required to track the photodetector fringes. For the presently planned mission, our analysis indeed demonstrates that noise from current-generation ultrastable oscillators would, if uncorrected, dominate the LISA noise budget. To meet the

  3. Implementation of time-delay interferometry for LISA

    International Nuclear Information System (INIS)

    Tinto, Massimo; Shaddock, Daniel A.; Sylvestre, Julien; Armstrong, J.W.

    2003-01-01

    We discuss the baseline optical configuration for the Laser Interferometer Space Antenna (LISA) mission, in which the lasers are not free-running, but rather one of them is used as the main frequency reference generator (the master) and the remaining five as slaves, these being phase-locked to the master (the master-slave configuration). Under the condition that the frequency fluctuations due to the optical transponders can be made negligible with respect to the secondary LISA noise sources (mainly proof-mass and shot noises), we show that the entire space of interferometric combinations LISA can generate when operated with six independent lasers (the one-way method) can also be constructed with the master-slave system design. The corresponding hardware trade-off analysis for these two optical designs is presented, which indicates that the two sets of systems needed for implementing the one-way method, and the master-slave configuration, are essentially identical. Either operational mode could therefore be implemented without major implications on the hardware configuration. We then derive the required accuracies of armlength knowledge, time synchronization of the onboard clocks, sampling times and time-shifts needed for effectively implementing time-delay interferometry for LISA. We find that an armlength accuracy of about 16 meters, a synchronization accuracy of about 50 ns, and the time jitter due to a presently existing space qualified clock will allow the suppression of the frequency fluctuations of the lasers below to the level identified by the secondary noise sources. A new procedure for sampling the data in such a way to avoid the problem of having time shifts that are not integer multiples of the sampling time is also introduced, addressing one of the concerns about the implementation of time-delay interferometry

  4. Algebraic approach to time-delay data analysis for LISA

    International Nuclear Information System (INIS)

    Dhurandhar, S.V.; Nayak, K. Rajesh; Vinet, J.-Y.

    2002-01-01

    Cancellation of laser frequency noise in interferometers is crucial for attaining the requisite sensitivity of the triangular three-spacecraft LISA configuration. Raw laser noise is several orders of magnitude above the other noises and thus it is essential to bring it down to the level of other noises such as shot, acceleration, etc. Since it is impossible to maintain equal distances between spacecrafts, laser noise cancellation must be achieved by appropriately combining the six beams with appropriate time delays. It has been shown in several recent papers that such combinations are possible. In this paper, we present a rigorous and systematic formalism based on algebraic geometrical methods involving computational commutative algebra, which generates in principle all the data combinations canceling the laser frequency noise. The relevant data combinations form the first module of syzygies, as it is called in the literature of algebraic geometry. The module is over a polynomial ring in three variables, the three variables corresponding to the three time delays around the LISA triangle. Specifically, we list several sets of generators for the module whose linear combinations with polynomial coefficients generate the entire module. We find that this formalism can also be extended in a straightforward way to cancel Doppler shifts due to optical bench motions. The two modules are in fact isomorphic. We use our formalism to obtain the transfer functions for the six beams and for the generators. We specifically investigate monochromatic gravitational wave sources in the LISA band and carry out the maximization over linear combinations of the generators of the signal-to-noise ratios with the frequency and source direction angles as parameters

  5. Rightsizing LISA

    International Nuclear Information System (INIS)

    Stebbins, R T

    2009-01-01

    The Laser Interferometer Space Antenna (LISA) science requirements and conceptual design have been fairly stable for over a decade. In the interest of reducing costs, the LISA Project at NASA has looked for simplifications of the architecture, at downsizing of subsystems and at descopes of the entire mission. This is a natural activity of the formulation phase and one that is particularly timely in the current NASA budgetary context. There is, and will continue to be, enormous pressure for cost reduction from both ESA and NASA, reviewers and the broader research community. Here, the rationale for the baseline architecture is reviewed, and recent efforts to find simplifications and other reductions that might lead to savings are reported. A few possible simplifications have been found in the LISA baseline architecture. In the interest of exploring cost sensitivity, one moderate and one aggressive descope have been evaluated; the cost savings are modest and the loss of science is not.

  6. Verification of time-delay interferometry techniques using the University of Florida LISA interferometry simulator

    Energy Technology Data Exchange (ETDEWEB)

    Mitryk, Shawn J; Wand, Vinzenz; Mueller, Guido, E-mail: smitryk@phys.ufl.ed, E-mail: mueller@phys.ufl.ed [Department of Physics, University of Florida, PO Box 118440, Gainesville, FL 32611-8440 (United States)

    2010-04-21

    Laser Interferometer Space Antenna (LISA) is a cooperative NASA/ESA mission proposed to directly measure gravitational waves (GW) in the frequency range from 30 muHz to 1 Hz with an optimal strain sensitivity of 10{sup -21}/sq root(Hz) at 3 mHz. LISA will utilize a modified Michelson interferometer to measure length changes of 40 pm/sq root(Hz) between drag-free proof masses located on three separate spacecraft (SC) separated by a distance of 5 Gm. The University of Florida has developed a hardware-in-the-loop simulator of the LISA constellation to verify the laser noise cancellation technique known as time-delay interferometry (TDI). We replicate the frequency stabilization of the laser on the local SC and the phase-locking of the lasers on the far SC. The laser photodetector beatnotes are electronically delayed, Doppler shifted and applied with a mock GW signal to simulate the laser link between the SC. The beatnotes are also measured with a LISA-like phasemeter and the data are used to extract the laser phase and residual phase-lock loop noise in post-processing through TDI. This uncovers the GW modulation signal buried under the laser noise. The results are then compared to the requirements defined by the LISA science collaboration.

  7. Black Holes, Gravitational Waves, and LISA

    Science.gov (United States)

    Baker, John

    2009-01-01

    Binary black hole mergers are central to many key science objectives of the Laser Interferometer Space Antenna (LISA). For many systems the strongest part of the signal is only understood by numerical simulations. Gravitational wave emissions are understood by simulations of vacuum General Relativity (GR). I discuss numerical simulation results from the perspective of LISA's needs, with indications of work that remains to be done. Some exciting scientific opportunities associated with LISA observations would be greatly enhanced if prompt electromagnetic signature could be associated. I discuss simulations to explore this possibility. Numerical simulations are important now for clarifying LISA's science potential and planning the mission. We also consider how numerical simulations might be applied at the time of LISA's operation.

  8. LISA time-delay interferometry zero-signal solution: Geometrical properties

    International Nuclear Information System (INIS)

    Tinto, Massimo; Larson, Shane L.

    2004-01-01

    Time-delay interferometry (TDI) is the data processing technique needed for generating interferometric combinations of data measured by the multiple Doppler readouts available onboard the three Laser Interferometer Space Antenna (LISA) spacecraft. Within the space of all possible interferometric combinations TDI can generate, we have derived a specific combination that has zero response to the gravitational wave signal, and called it the zero-signal solution (ZSS). This is a two-parameter family of linear combinations of the generators of the TDI space, and its response to a gravitational wave becomes null when these two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the ZSS does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind. Our approach is analogous to the data analysis method introduced by Guersel and Tinto in the context of networks of Earth-based, wideband, interferometric gravitational wave detectors observing in coincidence a gravitational wave burst. The ZSS should be regarded as an application of the Guersel and Tinto method to the LISA data

  9. Modulator noise suppression in the LISA time-delay interferometric combinations

    International Nuclear Information System (INIS)

    Tinto, Massimo; Armstrong, J W; Estabrook, Frank B

    2008-01-01

    Laser Interferometer Space Antenna (LISA) is a mission to detect and study low-frequency cosmic gravitational radiation through its influence on the phases of six modulated laser beams exchanged between three remote spacecraft. We previously showed how the measurements of some 18 time series of relative frequency or phase shifts could be combined (1) to cancel the phase noise of the lasers, (2) to cancel the Doppler fluctuations due to non-inertial motions of the six optical benches and (3) to remove the phase noise of the onboard reference oscillators required to track the photodetector fringes, all the while preserving signals from passing gravitational waves. Here we analyze the effect of the additional noise due to the optical modulators used for removing the phase fluctuations of the onboard reference oscillators. We use the recently measured noise spectrum of an individual modulator (Klipstein et al 2006 Proc. 6th Int. LISA Symp. (Greenbelt, MA) (AIP Conf. Proc. vol 873) ed S M Merkowitz and J C Livas pp 19-23) to quantify the contribution of modulator noise to the first and second-generation time-delay interferometric (TDI) combinations as a function of the modulation frequency. We show that modulator noise can be made smaller than the expected proof-mass acceleration and optical-path noises if the modulation frequencies are larger than ∼682 MHz in the case of the unequal-arm Michelson TDI combination X 1 , ∼ 1.08 GHz for the Sagnac TDI combination α 1 , and ∼706 MHz for the symmetrical Sagnac TDI combination ζ 1 . These modulation frequencies are substantially smaller than previously estimated and may lead to less stringent requirements on the LISA's oscillator noise calibration subsystem. The measurements in Klipstein et al were performed in a laboratory experiment for a range of modulation frequencies, but we emphasize that, for the reference oscillator noise calibration algorithm to work, the modulation frequencies must be equal to the

  10. The LISA Pathfinder Mission

    International Nuclear Information System (INIS)

    Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

    2015-01-01

    LISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter.The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper (paper)

  11. White-dwarf-white-dwarf galactic background in the LISA data

    International Nuclear Information System (INIS)

    Edlund, Jeffrey A.; Tinto, Massimo; Krolak, Andrzej; Nelemans, Gijs

    2005-01-01

    LISA (Laser Interferometer Space Antenna) is a proposed space mission, which will use coherent laser beams exchanged between three remote spacecraft to detect and study low-frequency cosmic gravitational radiation. In the low part of its frequency band, the LISA strain sensitivity will be dominated by the incoherent superposition of hundreds of millions of gravitational wave signals radiated by inspiraling white-dwarf binaries present in our own Galaxy. In order to estimate the magnitude of the LISA response to this background, we have simulated a synthesized population that recently appeared in the literature. Our approach relies on entirely analytic expressions of the LISA time-delay interferometric responses to the gravitational radiation emitted by such systems, which allows us to implement a computationally efficient and accurate simulation of the background in the LISA data. We find the amplitude of the galactic white-dwarf binary background in the LISA data to be modulated in time, reaching a minimum equal to about twice that of the LISA noise for a period of about two months around the time when the Sun-LISA direction is roughly oriented towards the Autumn equinox. This suggests that, during this time period, LISA could search for other gravitational wave signals incoming from directions that are away from the galactic plane. Since the galactic white-dwarf background will be observed by LISA not as a stationary but rather as a cyclostationary random process with a period of 1 yr, we summarize the theory of cyclostationary random processes, present the corresponding generalized spectral method needed to characterize such process, and make a comparison between our analytic results and those obtained by applying our method to the simulated data. We find that, by measuring the generalized spectral components of the white-dwarf background, LISA will be able to infer properties of the distribution of the white-dwarf binary systems present in our Galaxy

  12. LISA Pathfinder and eLISA news

    Science.gov (United States)

    Thorpe, James Ira; Mueller, Guido

    2014-01-01

    Two important gatherings of the space-based gravitational-wave detector community were held in Zurich, Switzerland this past March. The first was a meeting of the Science Working Team for LISA Pathfinder (LPF), a dedicated technology demonstrator mission for a future LISA-like gravitational wave observatory. LPF is entering an extremely exciting phase with launch less than 15 months away. All flight components for both the European science payload, known as the LISA Technology Package (LTP), and the NASA science payload, known as the Space Technology 7 Disturbance Reduction System (ST7-DRS), have been delivered and are undergoing integration. The final flight component for the spacecraft bus, a cold-gas thruster based on the successful GAIA design, will be delivered later this year. Current focus is on completing integration of the science payload (see Figures 1 and 2) and preparation for operations and data analysis. After a launch in Summer 2015, LPF will take approximately 90 days to reach its operational orbit around the Earth-Sun Lagrange point (L1), where it will begin science operations. After 90 days of LTP operations followed by 90 days of DRS operations, LPF will have completed its prime mission of paving the way for a space-based observatory of gravitational waves in the milliHertz band. Immediately following the meeting of the LPF team, the eLISA consortium held its third progress meeting. The consortium (www.elisascience.org) is the organizing body of the European space-based gravitational-wave community, and it was responsible for the "The Gravitational Universe" whitepaper that resulted in the November 2013 election of a gravitational-wave science theme for ESA's Cosmic Visions L3 opportunity. In preparation for an L3 mission concept call, which is expected later this decade, and for launch in the mid 2030s, the eLISA consortium members are coordinating technology development and mission study activities which will build on the LPF results. The final

  13. A noise simulator for eLISA: Migrating LISA Pathfinder knowledge to the eLISA mission

    OpenAIRE

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, Michael; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, Karsten; Diepholz, I.

    2015-01-01

    We present a new technical simulator for the eLISA mission, based on state space modeling techniques and developed in MATLAB. This simulator computes the coordinate and velocity over time of each body involved in the constellation, i.e. the spacecraft and its test masses, taking into account the different disturbances and actuations. This allows studying the contribution of instrumental noises and system imperfections on the residual acceleration applied on the TMs, the latter reflecting the ...

  14. The effects of orbital motion on LISA time delay interferometry

    International Nuclear Information System (INIS)

    Cornish, Neil J; Hellings, Ronald W

    2003-01-01

    In an effort to eliminate laser phase noise in laser interferometer spaceborne gravitational wave detectors, several combinations of signals have been found that allow the laser noise to be cancelled out while gravitational wave signals remain. This process is called time delay interferometry (TDI). In the papers that defined the TDI variables, their performance was evaluated in the limit that the gravitational wave detector is fixed in space. However, the performance depends on certain symmetries in the armlengths that are available if the detector is fixed in space, but that will be broken in the actual rotating and flexing configuration produced by the LISA orbits. In this paper we investigate the performance of these TDI variables for the real LISA orbits. First, addressing the effects of rotation, we verify Daniel Shaddock's result that the Sagnac variables α (t), β (t) and γ (t) will not cancel out the laser phase noise, and we also find the same result for the symmetric Sagnac variable ζ (t). The loss of the latter variable would be particularly unfortunate since this variable also cancels out gravitational wave signal, allowing instrument noise in the detector to be isolated and measured. Fortunately, we have found a set of more complicated TDI variables, which we call Δ Sagnac variables, one of which accomplishes the same goal as ζ (t) to good accuracy. Finally, however, as we investigate the effects of the flexing of the detector arms due to non-circular orbital motion, we show that all variables, including the interferometer variables, X(t), Y(t) and Z(t), which survive the rotation-induced loss of direction symmetry, will not completely cancel laser phase noise when the armlengths are changing with time. This unavoidable problem will place a stringent requirement on laser stability of ∼5 Hz Hz -1/2

  15. LISA and LISA PathFinder, the endeavour to detect low frequency GWs

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, H [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Boatella, C [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Chmeissani, M [Institut de Fisica d' Altes Energies (IFAE), Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain); Conchillo, A [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Garcia-Berro, E [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Grimani, C [Universita degli Studi di Urbino, and INFN Florence, Istituto di Fisica, Via Santa Chiara 27, 61029 Urbino (Italy); Hajdas, W [Department of Particles and Matter, Paul Scherrer Institut, ODRA 120, 5232 Villigen (Switzerland); Lobo, A [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Martinez, L [AtIpic, Parc Tecnologic del Valles, 08290 Cerdanyola del Valles, Barcelona (Spain); Nofrarias, M [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Ortega, J A [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Puigdengoles, C [Institut de Fisica d' Altes Energies (IFAE), Edifici C, Universitat Autonoma de Barcelona, 08193 Bellaterra (Barcelona) (Spain); Ramos-Castro, J [Departament d' Enginyeria Electronica, UPC, Campus Nord, Edif. C4, Jordi Girona 1-3, 08034 Barcelona (Spain); Sanjuan, J [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Wass, P [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Xirgu, X [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain)

    2007-05-15

    This is a review about LISA and its technology demonstrator, LISAPathFinder. We first describe the conceptual problems which need to be overcome in order to set up a working interferometric detector of low frequency Gravitational Waves (GW), then summarise the solutions to them as currently conceived by the LISA mission team. This will show that some of these solutions require new technological abilities which are still under development, and which need proper test before being fully implemented. LISAPathFinder (LPF) is the the testbed for such technologies. The final part of the paper will address the ideas and concepts behind the PathFinder as well as their impact on LISA.

  16. LISA and LISA PathFinder, the endeavour to detect low frequency GWs

    International Nuclear Information System (INIS)

    Araujo, H; Boatella, C; Chmeissani, M; Conchillo, A; Garcia-Berro, E; Grimani, C; Hajdas, W; Lobo, A; Martinez, L; Nofrarias, M; Ortega, J A; Puigdengoles, C; Ramos-Castro, J; Sanjuan, J; Wass, P; Xirgu, X

    2007-01-01

    This is a review about LISA and its technology demonstrator, LISAPathFinder. We first describe the conceptual problems which need to be overcome in order to set up a working interferometric detector of low frequency Gravitational Waves (GW), then summarise the solutions to them as currently conceived by the LISA mission team. This will show that some of these solutions require new technological abilities which are still under development, and which need proper test before being fully implemented. LISAPathFinder (LPF) is the the testbed for such technologies. The final part of the paper will address the ideas and concepts behind the PathFinder as well as their impact on LISA

  17. Programme [11. international LISA symposium, Zurich (Switzerland), 5-9 September 2016

    International Nuclear Information System (INIS)

    2017-01-01

    -band gravitational wave astronomy B. Sathyaprakash Exploring the Universe with third generation interferometers S. Sato The status of DECIGO G. Heinzel Satellite interferometry from LTP and GRACE Follow-On to LISA P. Binetruy Cosmology with LISA Chair: S. Vitale A. Giménez Cañete Beyond LISA Pathfinder P. Hertz NASA Astrophysics Program: Present and Future F. Safa ESA activities towards the Gravitation Waves Space Observatory H. Ward LPF Interferometry and route to LISA J. Camp Development of a US Laser System for the Gravitational Wave Mission LISA T. Schwarze Performance of an optical three-signal test for the LISA metrology M. Laporte Status of the eLISA on table (LOT) electro-optical simulator for space based gravitational waves observatories S. Apple UF Torsion Pendulum and GRS Technology Development J. Livas eLISA Telescope In-field Pointing and Scattered Light Study K. Isleif The LISA backlink – comparing optical phase reference systems Wednesday, 7th of September 2016 Chair: C. Sopuerta T. Alexander EMRIs and the relativistic loss cone R. Schoedel The stellar cusp around the Milky Way’s central black hole J. Gair Impact of eLISA design on EMRI Science M. van de Meent Modelling spinning EMRIs with Self-Force A. Gianninas A Progress Report on the Search for the Most Extreme Binary White Dwarfs I. Thorpe Initial Results from ST7-Disturbance Reduction System on LISA Pathfinder G. Jin Ongoing development of detection of gravitational waves in space in China Thursday, 8th of September 2016 Chair: P. Binetruy R. Blandford The Future of Black Hole Astrophysics in the LISA-VIRGO-LPF Era C. Moore Observing black hole merger kicks directly with gravitational waves N. Tamanini Late time cosmology with eLISA I. Dvorkin A synthetic model of the gravitational wave background from evolving binary compact objects A. Petiteau LISA science performance in the context of LISAPathfinder first results and simulation for LISA N. Cornish Fast, fully precessing frequency domain waveforms for

  18. LISA system design highlights

    Energy Technology Data Exchange (ETDEWEB)

    Sallusti, M [European Space Agency, ESTEC, Keplerlaan 1, 2200 AG Noordwijk ZH (Netherlands); Gath, P; Weise, D; Berger, M; Schulte, H R, E-mail: marcello.sallusti@esa.in, E-mail: peter.gath@astrium.eads.ne, E-mail: dennis.weise@astrium.eads.ne, E-mail: marcel.berger@astrium.eads.ne, E-mail: Hans.Reiner.Schulte@astrium.eads.ne [Astrium GmbH Satellites, Claude-Dornier-Str., 88039 Friedrichshafen (Germany)

    2009-05-07

    A contract, started in January 2005, was awarded to a consortium of Astrium GmbH and Astrium Ltd for the LISA Mission Formulation. The scope of the contract was the development of a reference design for the mission architecture and for the mission elements (with particular focus on the payload) and a successive phase of derivation of requirements, to be concluded with a mission design review. The technical starting point was the output of the previous LISA study formalized in the Final Technical Report, issued in the year 2000. During the design phase, different architecture concepts were identified and traded off, including the LISA orbits, the measurement scheme and the opto-mechanical architecture. During the Mission Design Review (July 2008) the consolidated mission baseline design, and the specifications of the flight elements and of the payload subsystem and major components were presented. This paper gives a brief overview of the major design points of the latest design of the LISA system.

  19. LISA system design highlights

    International Nuclear Information System (INIS)

    Sallusti, M; Gath, P; Weise, D; Berger, M; Schulte, H R

    2009-01-01

    A contract, started in January 2005, was awarded to a consortium of Astrium GmbH and Astrium Ltd for the LISA Mission Formulation. The scope of the contract was the development of a reference design for the mission architecture and for the mission elements (with particular focus on the payload) and a successive phase of derivation of requirements, to be concluded with a mission design review. The technical starting point was the output of the previous LISA study formalized in the Final Technical Report, issued in the year 2000. During the design phase, different architecture concepts were identified and traded off, including the LISA orbits, the measurement scheme and the opto-mechanical architecture. During the Mission Design Review (July 2008) the consolidated mission baseline design, and the specifications of the flight elements and of the payload subsystem and major components were presented. This paper gives a brief overview of the major design points of the latest design of the LISA system.

  20. LISA and the LTP

    International Nuclear Information System (INIS)

    Jennrich, O.

    2002-01-01

    The primary objective of the LISA (Laser Interferometer Space Antenna mission is the detection and observation of gravitational waves from massive black holes (MBH) and galactic binaries in the frequency range 10 -4 Hz ... 10 -1 Hz. This low-frequency range is inaccessible to ground-based interferometers due to the background of local gravitational noise and because ground-based interferometers are limited in length to a few kilometres. LISA is envisaged as an ESA/NASA collaborative project, selected an ESA cornerstone mission and included in NASA's strategic plan and with a nominal launch date in 2011. SMART-2 is primarily intended to demonstrate the key technologies for the ESA/NASA collaborative LISA cornerstone mission. The synergy with the technology being used for Darwin motivates the utilization of SMART-2 for both missions. To this end, SMART-2 will accommodate a LISA technology package (LTP), provided by European institutes and industry and possibly also a Disturbance Reduction System (DRS) that is very similar to the LTP and has the same goals but is provided by US institutes and industry

  1. Ground-based self-gravity tests for LISA Pathfinder and LISA

    International Nuclear Information System (INIS)

    Trenkel, C; Warren, C; Wealthy, D

    2009-01-01

    Gravitational coupling between the free-falling test masses and the surrounding spacecraft is one of the dominant noise sources for both LISA Pathfinder and LISA. At present, there are no plans to verify any of the self-gravity requirements by test, on the ground. Here, we explore the possibilities of conducting such tests, using a customised torsion balance. We discuss the main sources of systematic and statistical uncertainty present in such a set-up. Our preliminary assessment indicates that the sensitivity is sufficient to carry out meaningful self-gravity tests.

  2. Optimal statistic for detecting gravitational wave signals from binary inspirals with LISA

    CERN Document Server

    Rogan, A

    2004-01-01

    A binary compact object early in its inspiral phase will be picked up by its nearly monochromatic gravitational radiation by LISA. But even this innocuous appearing candidate poses interesting detection challenges. The data that will be scanned for such sources will be a set of three functions of LISA's twelve data streams obtained through time-delay interferometry, which is necessary to cancel the noise contributions from laser-frequency fluctuations and optical-bench motions to these data streams. We call these three functions pseudo-detectors. The sensitivity of any pseudo-detector to a given sky position is a function of LISA's orbital position. Moreover, at a given point in LISA's orbit, each pseudo-detector has a different sensitivity to the same sky position. In this work, we obtain the optimal statistic for detecting gravitational wave signals, such as from compact binaries early in their inspiral stage, in LISA data. We also present how the sensitivity of LISA, defined by this optimal statistic, vari...

  3. A UV LED-based Charge Management System for LISA

    Science.gov (United States)

    Conklin, John W.; Chilton, Andrew; Olatunde, Taiwo Janet; Apple, Stephen; Parry, Samantha; Ciani, Giacomo; Wass, Peter; Mueller, Guido

    2018-01-01

    The Laser Interferometer Space Antenna (LISA) will be the first space instrument to observe gravitational waves in the millihertz frequency band. LISA consists of three Sun-orbiting spacecraft that form an equilateral triangle, with each side measuring 2.5 million kilometers in length. Each spacecraft houses two free-floating test masses, which are protected from all disturbing forces so that they follow pure geodesics in spacetime. A drag-free control system commands micronewton thrusters to force the spacecraft to fly in formation with the test masses and laser interferometers measure the minute variations in the distance, or light travel time, between these free-falling test masses caused by gravitational waves. The LISA observatory, with a planned launch in the early 2030s, is led by the European Space Agency with significant contributions from NASA. Recently, NASA has initiated strategic investments in key LISA technologies that will likely become U.S. flight hardware contributions to this ground-breaking mission. One of these payload elements is the Charge Management System (CMS), which controls the electric potential of the test masses relative to their housings to reduce spurious force noise acting on the test masses to below the required level. This talk, presented by University of Florida team that leads the CMS development, will describe this vital U.S. contribution to the LISA mission in the context of the envisioned LISA payload architecture and its in-flight sensitivity to gravitational waves.

  4. Reconstructing the dark sector interaction with LISA

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Rong-Gen; Yang, Tao [CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China); Tamanini, Nicola, E-mail: cairg@itp.ac.cn, E-mail: nicola.tamanini@cea.fr, E-mail: yangtao@itp.ac.cn [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-05-01

    We perform a forecast analysis of the ability of the LISA space-based interferometer to reconstruct the dark sector interaction using gravitational wave standard sirens at high redshift. We employ Gaussian process methods to reconstruct the distance-redshift relation in a model independent way. We adopt simulated catalogues of standard sirens given by merging massive black hole binaries visible by LISA, with an electromagnetic counterpart detectable by future telescopes. The catalogues are based on three different astrophysical scenarios for the evolution of massive black hole mergers based on the semi-analytic model of E. Barausse, Mon. Not. Roy. Astron. Soc. 423 (2012) 2533. We first use these standard siren datasets to assess the potential of LISA in reconstructing a possible interaction between vacuum dark energy and dark matter. Then we combine the LISA cosmological data with supernovae data simulated for the Dark Energy Survey. We consider two scenarios distinguished by the time duration of the LISA mission: 5 and 10 years. Using only LISA standard siren data, the dark sector interaction can be well reconstructed from redshift z ∼1 to z ∼3 (for a 5 years mission) and z ∼1 up to z ∼5 (for a 10 years mission), though the reconstruction is inefficient at lower redshift. When combined with the DES datasets, the interaction is well reconstructed in the whole redshift region from 0 z ∼ to z ∼3 (5 yr) and z ∼0 to z ∼5 (10 yr), respectively. Massive black hole binary standard sirens can thus be used to constrain the dark sector interaction at redshift ranges not reachable by usual supernovae datasets which probe only the z ∼< 1.5 range. Gravitational wave standard sirens will not only constitute a complementary and alternative way, with respect to familiar electromagnetic observations, to probe the cosmic expansion, but will also provide new tests to constrain possible deviations from the standard ΛCDM dynamics, especially at high redshift.

  5. Molecular laser stabilization for LISA

    Science.gov (United States)

    Halloin, Hubert; Acef, Ouali; Argence, Berengere; Jeannin, Olivier; Prat, Pierre; de Vismes, Eden; Plagnol, Eric; Brillet, Alain; Mondin, Linda; Berthon, Jacques; Turazza, Oscar

    2017-11-01

    The expected performance of LISA relies on two main technical challenges: the ability for the spacecrafts to precisely follow the free-flying masses and the outstanding precision of the phase shift measurement. This latter constraint requires frequency stabilized lasers and efficient numerical algorithms to account for the redundant, delayed noise propagation, thus cancelling laser phase noise by many orders of magnitude (TDI methods). Recently involved in the technical developments for LISA, the goal of our team at APC (France) is to contribute on these two subjects: frequency reference for laser stabilization and benchtop simulation of the interferometer. In the present design of LISA, two stages of laser stabilization are used (not accounting for the "post-processed" TDI algorithm): laser pre-stabilization on a frequency reference and lock on the ultra stable distance between spacecrafts (arm-locking). While the foreseen (and deeply studied) laser reference consists of a Fabry-Perot cavity, other techniques may be suitable for LISA or future metrology missions. In particular, locking to a molecular reference (namely iodine in the case of the LISA Nd:YAG laser) is an interesting alternative. It offers the required performance with very good long-term stability (absolute frequency reference) though the reference can be slightly tuned to account for arm-locking. This technique is currently being investigated by our team and optimized for LISA (compactness, vacuum compatibility, ease of use and initialization, etc.). A collaboration with a French laboratory (the SYRTE) had been started aiming to study a second improved technique consisting in inserting the iodine cell in a Fabry-Perot cavity. Ongoing results and prospects to increase the performance of the system are presented in the present article.

  6. Control system design for the constellation acquisition phase of the LISA mission

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, Francesca; Gath, Peter F, E-mail: francesca.cirillo@astrium.eads.ne, E-mail: peter.gath@astrium.eads.ne [Astrium GmbH Satellites, 88039 Friedrichshafen (Germany)

    2009-03-01

    The objective of the constellation acquisition phase for the LISA mission is to establish the three laser links between the three spacecraft of the LISA constellation so that the interferometric measurements for the science experiment can commence. The laser beam acquisition for LISA is extremely challenging given the 5 million km distance between the spacecraft, the inherent limits of the attitude sensors accuracy, the orbit determination accuracy issues and the time required to phase-lock the incoming and outgoing laser signals. This paper presents the design of the control system for the acquisition phase of the LISA constellation: the acquisition operational procedure is outlined, guidance laws are defined together with the Gyro Mode attitude control principle, which implements a Kalman filter for disturbances rejection purposes. Constellation-wide non-linear simulations demonstrate that the LISA constellation acquisition phase is feasible by means of the proposed control strategy.

  7. Control system design for the constellation acquisition phase of the LISA mission

    International Nuclear Information System (INIS)

    Cirillo, Francesca; Gath, Peter F

    2009-01-01

    The objective of the constellation acquisition phase for the LISA mission is to establish the three laser links between the three spacecraft of the LISA constellation so that the interferometric measurements for the science experiment can commence. The laser beam acquisition for LISA is extremely challenging given the 5 million km distance between the spacecraft, the inherent limits of the attitude sensors accuracy, the orbit determination accuracy issues and the time required to phase-lock the incoming and outgoing laser signals. This paper presents the design of the control system for the acquisition phase of the LISA constellation: the acquisition operational procedure is outlined, guidance laws are defined together with the Gyro Mode attitude control principle, which implements a Kalman filter for disturbances rejection purposes. Constellation-wide non-linear simulations demonstrate that the LISA constellation acquisition phase is feasible by means of the proposed control strategy.

  8. Free-flight experiments in LISA Pathfinder

    International Nuclear Information System (INIS)

    Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Cutler, C; Dunbar, N; Ferraioli, L

    2015-01-01

    The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this ‘suspension noise’. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data. (paper)

  9. LISA Beyond Einstein: From the Big Bang to Black Holes. LISA Technology Development at GSFC

    Science.gov (United States)

    Thorpe, James Ira

    2008-01-01

    This viewgraph presentation reviews the work that has been ongoing at the Goddard Space Flight Center (GSFC) in the development of the technology to be used in the Laser Interferometer Space Antenna (LISA) spacecrafts. The prime focus of LISA technology development efforts at NASA/GSFC has been in LISA interferometry. Specifically efforts have been made in the area of laser frequency noise mitigation. Laser frequency noise is addressed through a combination of stabilization and common-mode rejection. Current plans call for two stages of stabilization, pre-stabilization to a local frequency reference and further stabilization using the constellation as a frequency reference. In order for these techniques to be used simultaneously, the pre-stabilization step must provide an adjustable frequency offset. This presentation reports on a modification to the standard modulation/demodulation technique used to stabilize to optical cavities that generates a frequency-tunable reference from a fixed length cavity. This technique requires no modifications to the cavity itself and only minor modifications to the components. The measured noise performance and dynamic range of the laboratory prototype meet the LISA requirements.

  10. LISA Pathfinder: A Mission Status

    Science.gov (United States)

    Hewitson, Martin; LISA Pathfinder Team Team

    2016-03-01

    On December 3rd at 04:04 UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space. This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.

  11. Improving the sensitivity of LISA

    International Nuclear Information System (INIS)

    Nayak, K Rajesh; Pai, A; Dhurandhar, S V; Vinet, J-Y

    2003-01-01

    It has been shown in several recent papers that the six Doppler data streams obtained from a triangular LISA configuration can be combined by appropriately delaying the data streams for cancelling the laser frequency noise. Raw laser noise is several orders of magnitude above the other noises and thus it is essential to bring it down to the level of other noises such as shot, acceleration, etc. A rigorous and systematic formalism using the powerful techniques of computational commutative algebra was developed, which generates in principle all the data combinations cancelling the laser frequency noise. The relevant data combinations form a first module of syzygies. In this paper, we use this formalism to advantage for optimizing the sensitivity of LISA by analysing the noise and signal covariance matrices. The signal covariance matrix is calculated for binaries whose frequency changes at most adiabatically and the signal is averaged over polarizations and directions. We then present the extremal SNR curves for all the data combinations in the module. They correspond to the eigenvectors of the noise and signal covariance matrices. A LISA 'network' SNR is also computed by combining the outputs of the eigenvectors. We show that substantial gains in sensitivity can be obtained by employing these strategies. The maximum SNR curve can yield an improvement up to 70% over the Michelson, mainly at high frequencies, while the improvement using the network SNR ranges from 40% to over 100%. Finally, we describe a simple toy model, in which LISA rotates in a plane. In this analysis, we estimate the improvement in the LISA sensitivity, if one switches from one data combination to another as it rotates. Here the improvement in sensitivity, if one switches optimally over three cyclic data combinations of the eigenvector, is about 55% on average over the LISA bandwidth. The corresponding SNR improvement increases to 60%, if one maximizes over the module

  12. LISA package user guide. Part II: LISA (Long Term Isolation Safety Assessment) program description and user guide

    International Nuclear Information System (INIS)

    Prado, P.; Saltelli, A.; Homma, T.

    1992-01-01

    This manual is subdivided into three parts. In this second part, this document describes the LISA (Long term Isolation Safety Assessment) Code and its submodels. LISA is a tool for analysis of the safety of an underground disposal of nuclear waste. It has the capability to handle nuclide chain of arbitrary length and to evaluate the migration of nuclide through a geosphere medium composed of an arbitrary number of segments. LISA makes use of Monte Carlo methodology to evaluate the uncertainty in the quantity being assessed (eg dose) arising from the uncertainty in the model input parameters. In the present version LISA is equipped with a very simple source term submodel, a relatively complex geosphere and a simplified biosphere. The code is closely associated with its statistical pre-processor code (PREP), which generates the input Monte Carlo sample from the assigned parameter probability density functions and with its post-processor code (SPOP) which provides useful statistics on the output sample (uncertainty and sensitivity analysis). This report describes the general structure of LISA, its subroutines and submodels, the code input ant output files. It is intended to provide the user with enough information to know and run the code as well as the capacity to incorporate different submodels. 15 refs., 6 figs

  13. Optimizing the Earth-LISA 'rendezvous'

    International Nuclear Information System (INIS)

    De Marchi, Fabrizio; Pucacco, Giuseppe; Bassan, Massimo

    2012-01-01

    We present a general survey of heliocentric LISA orbits, hoping that it might help in the exercise of rescoping the mission. We try to semi-analytically optimize the orbital parameters in order to minimize the disturbances coming from the Earth-LISA interaction. In a set of numerical simulations, we include non-autonomous perturbations and provide an estimate of Doppler shift and breathing as a function of the trailing angle. (paper)

  14. LISA Pathfinder test-mass charging during galactic cosmic-ray flux short-term variations

    Science.gov (United States)

    Grimani, C.; Fabi, M.; Lobo, A.; Mateos, I.; Telloni, D.

    2015-02-01

    Metal free-floating test masses aboard the future interferometers devoted to gravitational wave detection in space are charged by galactic and solar cosmic rays with energies \\gt 100 MeV/n. This process represents one of the main sources of noise in the lowest frequency band (\\lt 10-3 Hz) of these experiments. We study here the charging of the LISA Pathfinder (LISA-PF) gold-platinum test masses due to galactic cosmic-ray (GCR) protons and helium nuclei with the Fluka Monte Carlo toolkit. Projections of the energy spectra of GCRs during the LISA-PF operations in 2015 are considered. This work was carried out on the basis of the solar activity level and solar polarity epoch expected for LISA-PF. The effects of GCR short-term variations are evaluated here for the first time. Classical Forbush decreases, GCR variations induced by the Sun rotation, and fluctuations in the LISA-PF frequency bandwidth are discussed.

  15. Confusion noise from LISA capture sources

    International Nuclear Information System (INIS)

    Barack, Leor; Cutler, Curt

    2004-01-01

    Captures of compact objects (COs) by massive black holes (MBHs) in galactic nuclei will be an important source for LISA, the proposed space-based gravitational wave (GW) detector. However, a large fraction of captures will not be individually resolvable - either because they are too distant, have unfavorable orientation, or have too many years to go before final plunge - and so will constitute a source of 'confusion noise', obscuring other types of sources. In this paper we estimate the shape and overall magnitude of the GW background energy spectrum generated by CO captures. This energy spectrum immediately translates to a spectral density S h capt (f) for the amplitude of capture-generated GWs registered by LISA. The overall magnitude of S h capt (f) is linear in the CO capture rates, which are rather uncertain; therefore we present results for a plausible range of rates. S h capt (f) includes the contributions from both resolvable and unresolvable captures, and thus represents an upper limit on the confusion noise level. We then estimate what fraction of S h capt (f) is due to unresolvable sources and hence constitutes confusion noise. We find that almost all of the contribution to S h capt (f) coming from white dwarf and neutron star captures, and at least ∼30% of the contribution from black hole captures, is from sources that cannot be individually resolved. Nevertheless, we show that the impact of capture confusion noise on the total LISA noise curve ranges from insignificant to modest, depending on the rates. Capture rates at the high end of estimated ranges would raise LISA's overall (effective) noise level [fS h eff (f)] 1/2 by at most a factor ∼2 in the frequency range 1-10 mHz, where LISA is most sensitive. While this slightly elevated noise level would somewhat decrease LISA's sensitivity to other classes of sources, we argue that, overall, this would be a pleasant problem for LISA to have: It would also imply that detection rates for CO captures

  16. Lisa Woodward | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    Lisa Woodward is Special Advisor to the President. Before joining IDRC, Lisa held positions in strategic planning, performance measurement, evaluation, risk management, and policy development in federal organizations, including Fisheries and Oceans Canada, the Canadian International Development Agency, and the ...

  17. Galactic binaries with eLISA

    OpenAIRE

    Nelemans, G.

    2013-01-01

    I review what eLISA will see from Galactic binaries -- double stars with orbital periods less than a few hours and white dwarf (or neutron star/black hole) components. I discuss the currently known binaries that are guaranteed (or verification) sources and explain why the expected total number of eLISA Galactic binaries is several thousand, even though there are large uncertainties in our knowledge of this population, in particular that of the interacting AM CVn systems. I very briefly sketch...

  18. From LPF to eLISA: new approach in payload software

    Science.gov (United States)

    Gesa, Ll.; Martin, V.; Conchillo, A.; Ortega, J. A.; Mateos, I.; Torrents, A.; Lopez-Zaragoza, J. P.; Rivas, F.; Lloro, I.; Nofrarias, M.; Sopuerta, CF.

    2017-05-01

    eLISA will be the first observatory in space to explore the Gravitational Universe. It will gather revolutionary information about the dark universe. This implies a robust and reliable embedded control software and hardware working together. With the lessons learnt with the LISA Pathfinder payload software as baseline, we will introduce in this short article the key concepts and new approaches that our group is working on in terms of software: multiprocessor, self-modifying-code strategies, 100% hardware and software monitoring, embedded scripting, Time and Space Partition among others.

  19. Possible LISA Technology Applications for Other Missions

    Science.gov (United States)

    Livas, Jeffrey

    2018-01-01

    The Laser Interferometer Space Antenna (LISA) has been selected as the third large class mission launch opportunity of the Cosmic Visions Program by the European Space Agency (ESA). LISA science will explore a rich spectrum of astrophysical gravitational-wave sources expected at frequencies between 0.0001 and 0.1 Hz and complement the work of other observatories and missions, both space and ground-based, electromagnetic and non-electromagnetic. Similarly, LISA technology may find applications for other missions. This paper will describe the capabilities of some of the key technologies and discuss possible contributions to other missions.

  20. LISA and asteroids

    International Nuclear Information System (INIS)

    Vinet, Jean-Yves

    2006-01-01

    LISA is a joint ESA-NASA mission aiming for cosmic gravitational wave detection and analysis. We address here the question of a special kind of signal caused by asteroid encounters. We present a short theory of the detection of such signals

  1. Performance of arm locking in LISA

    International Nuclear Information System (INIS)

    McKenzie, Kirk; Spero, Robert E.; Shaddock, Daniel A.

    2009-01-01

    For the Laser Interferometer Space Antenna (LISA) to reach its design sensitivity, the coupling of the free-running laser frequency noise to the signal readout must be reduced by more than 14 orders of magnitude. One technique employed to reduce the laser frequency noise will be arm locking, where the laser frequency is locked to the LISA arm length. In this paper we detail an implementation of arm locking. We investigate orbital effects (changing arm lengths and Doppler frequencies), the impact of errors in the Doppler knowledge that can cause pulling of the laser frequency, and the noise limit of arm locking. Laser frequency pulling is examined in two regimes: at lock acquisition and in steady state. The noise performance of arm locking is calculated with the inclusion of the dominant expected noise sources: ultrastable oscillator (clock) noise, spacecraft motion, and shot noise. We find that clock noise and spacecraft motion limit the performance of dual arm locking in the LISA science band. Studying these issues reveals that although dual arm locking [A. Sutton and D. A. Shaddock, Phys. Rev. D 78, 082001 (2008)] has advantages over single (or common) arm locking in terms of allowing high gain, it has disadvantages in both laser frequency pulling and noise performance. We address this by proposing a modification to the dual arm-locking sensor, a hybrid of common and dual arm-locking sensors. This modified dual arm-locking sensor has the laser frequency pulling characteristics and low-frequency noise coupling of common arm locking, but retains the control system advantages of dual arm locking. We present a detailed design of an arm-locking controller and perform an analysis of the expected performance when used with and without laser prestabilization. We observe that the sensor phase changes beneficially near unity-gain frequencies of the arm-locking controller, allowing a factor of 10 more gain than previously believed, without degrading stability. With a time

  2. Laser modulator for LISA pathfinder

    Science.gov (United States)

    Voland, C.; Lund, G.; Coppoolse, W.; Crosby, P.; Stadler, M.; Kudielka, K.; Özkan, C.

    2017-11-01

    LISA Pathfinder is an ESA experiment to demonstrate the key technologies needed for the LISA mission to detect gravitational waves in space. The LISA Pathfinder spacecraft represents one arm of the LISA interferometer, containing an optical metrology system and two proof masses as inertial references for the drag-free control system. The LISA Pathfinder payload consists of two drag-free floating test masses located in the inertial sensors with their control electronics and an optical metrology subsystem. The optical metrology subsystem monitors the movement of both test masses relative to each other and to the spacecraft with very high sensitivity and resolution. This is achieved with a heterodyne Mach- Zehnder interferometer. This interferometer requires as input two coherent laser beams with a heterodyne frequency difference of a few kHz. To generate the two laser beams with a heterodyne frequency difference a Nd:YAG laser is used together with the Laser Modulator. The Nd:YAG laser generates a single coherent laser signal at a wavelength of 1064nm which is fibre coupled to the Laser Modulator. The Laser Modulator then generates the two optical beams with the required heterodyne frequency offset. In addition, the Laser Modulator is required to perform laser amplitude stabilization and optical path difference control for the two optical signals. The Laser Modulator consists of an optical unit - the LMU - and RF synthesiser, power amplification and control electronics. These electronics are all housed in the Laser Modulator Electronics (LME). The LMU has four primary functions: • Splitting of the input laser beam into two paths for later superposition in the interferometer. • Applying different frequency shifts to each of the beams. • Providing amplitude modulation control to each of the beams. • Providing active control of the optical path length difference between the two optical paths. The present paper describes the design and performance of the LMU

  3. LISA and its in-flight test precursor SMART-2

    International Nuclear Information System (INIS)

    Vitale, S.; Bender, P.; Brillet, A.; Buchman, S.; Cavalleri, A.; Cerdonio, M.; Cruise, M.; Cutler, C.; Danzmann, K.; Dolesi, R.; Folkner, W.; Gianolio, A.; Jafry, Y.; Hasinger, G.; Heinzel, G.; Hogan, C.; Hueller, M.; Hough, J.; Phinney, S.; Prince, T.; Richstone, D.; Robertson, D.; Rodrigues, M.; Ruediger, A.; Sandford, M.; Schilling, R.; Shoemaker, D.; Schutz, B.; Stebbins, R.; Stubbs, C.; Sumner, T.; Thorne, K.; Tinto, M.; Touboul, P.; Ward, H.; Weber, W.; Winkler, W.

    2002-01-01

    LISA will be the first space-home gravitational wave observatory. It aims to detect gravitational waves in the 0.1 mHz/1 Hz range from sources including galactic binaries, super-massive black-hole binaries, capture of objects by super-massive black-holes and stochastic background. LISA is an ESA approved Cornerstone Mission foreseen as a joint ESA-NASA endeavour to be launched in 2010-11. The principle of operation of LISA is based on laser ranging of test-masses under pure geodesic motion. Achieving pure geodesic motion at the level requested for LISA, 3x10 -15 ms -2 /√Hz at 0.1 mHz, is considered a challenging technological objective. To reduce the risk, both ESA and NASA are pursuing an in-flight test of the relevant technology. The goal of the test is to demonstrate geodetic motion within one order of magnitude from the LISA performance. ESA has given this test as the primary goal of its technology dedicated mission SMART-2 with a launch in 2006. This paper describes the basics of LISA, its key technologies, and its in-flight precursor test on SMART-2

  4. LISA: Probing the Universe with Gravitational Waves

    NARCIS (Netherlands)

    Prince, T.A.; Binetruy, P.; Centrella, J.; Finn, L.S.; Hogan, C.; Nelemans, G.A.; Phinney, E.S.; Schutz, B.; Team, L.I.S.

    2006-01-01

    LISA is a joint NASA/ESA space mission for detection and study of low-frequency gravitational waves in the band from 0.1 mHz to 0.1 Hz. The mission consists of three satellites separated by a nominal distance of 5 million kilometers, with precision metrology provided by laser ranging. LISA will

  5. Multi-Messenger Astronomy: White Dwarf Binaries, LISA and GAIA

    Science.gov (United States)

    Bueno, Michael; Breivik, Katelyn; Larson, Shane L.

    2017-01-01

    The discovery of gravitational waves has ushered in a new era in astronomy. The low-frequency band covered by the future LISA detector provides unprecedented opportunities for multi-messenger astronomy. With the Global Astrometric Interferometer for Astrophysics (GAIA) mission, we expect to discover about 1,000 eclipsing binary systems composed of a WD and a main sequence star - a sizeable increase from the approximately 34 currently known binaries of this type. In advance of the first GAIA data release and the launch of LISA within the next decade, we used the Binary Stellar Evolution (BSE) code simulate the evolution of White Dwarf Binaries (WDB) in a fixed galaxy population of about 196,000 sources. Our goal is to assess the detectability of a WDB by LISA and GAIA using the parameters from our population synthesis, we calculate GW strength h, and apparent GAIA magnitude G. We can then use a scale factor to make a prediction of how many multi- messenger sources we expect to be detectable by both LISA and GAIA in a galaxy the size of the Milky Way. We create binaries 10 times to ensure randomness in distance assignment and average our results. We then determined whether or not astronomical chirp is the difference between the total chirp and the GW chirp. With Astronomical chirp and simulations of mass transfer and tides, we can gather more information about the internal astrophysics of stars in ultra-compact binary systems.

  6. Gravitational Reference Sensor Front-End Electronics Simulator for LISA

    International Nuclear Information System (INIS)

    Meshksar, Neda; Ferraioli, Luigi; Mance, Davor; Zweifel, Peter; Giardini, Domenico; Ten Pierick, Jan

    2017-01-01

    At the ETH Zurich we are developing a modular simulator that provides a realistic simulation of the Front End Electronics (FEE) for LISA Gravitational Reference Sensor (GRS). It is based on the GRS FEE-simulator already implemented for LISA Pathfinder. It considers, in particular, the non-linearity and the critical details of hardware, such as the non-linear multiplicative noise caused by voltage reference instability, test mass charging and detailed actuation and sensing algorithms. We present the simulation modules, considering the above-mentioned features. Based on the ETH GRS FEE-simulator for LISA Pathfinder we aim to develop a modular simulator that provides a realistic simulation of GRS FEE for LISA. (paper)

  7. Lisa Jevbratt / Lisa Jevbratt ; interv. Tilman Baumgärtel

    Index Scriptorium Estoniae

    Jevbratt, Lisa

    2006-01-01

    1967. a. Rootsis sündinud ja USA-s elavast kunstnikust Lisa Jevbrattist ning tema loomingust, 2000. a. jaanuaris tehtud meiliintervjuu kunstnikuga. L. Jevbratt kuulub rühmitusse C5, tema teosed keskenduvad pigem Interneti struktuurile kui selle sisule. Pikemalt võrguteosest "1:1" (2000), mille teemaks on IP-aadressid., lühidalt tööst "The Stillman Project" (1997), kunstniku galeriist "Non-Site"

  8. Mona Lisa kuulsa naeratuse saladus leidis lahenduse / Johannes Saar

    Index Scriptorium Estoniae

    Saar, Johannes, 1965-

    2004-01-01

    Firenze kunstiajalooõpetaja Giuseppe Pallanti jõudis 25-aastase arhiivitöö tulemusena järeldusele, et Leonardo da Vinci Mona Lisa modelliks on siidikaupmehe Francesco del Giocondo abikaasa Lisa Gerardini

  9. Sky Localization of Complete Inspiral-Merger-Ringdown Signals for Nonspinning Black Hole Binaries with LISA

    Science.gov (United States)

    McWilliams, Sean T.; Lang, Ryan N.; Baker, John G.; Thorpe, James Ira

    2011-01-01

    We investigate the capability of LISA to measure the sky position of equal-mass, nonspinning black hole binaries, including for the first time the entire inspiral-merger-ringdown signal, the effect of the LISA orbits, and the complete three-channel LISA response. For an ensemble of systems near the peak of LISA's sensitivity band, with total rest mass of 2 x l0(exp 6) Stellar Mass at a redshift of z = 1 with random orientations and sky positions, we find median sky localization errors of approximately approx. 3 arcminutes. This is comparable to the field of view of powerful electromagnetic telescopes, such as the James Webb Space Telescope, that could be used to search for electromagnetic signals associated with merging black holes. We investigate the way in which parameter errors decrease with measurement time, focusing specifically on the additional information provided during the merger-ringdown segment of the signal. We find that this information improves all parameter estimates directly, rather than through diminishing correlations with any subset of well-determined parameters.

  10. Doing Science with eLISA: Astrophysics and Cosmology in the Millihertz Regime

    Science.gov (United States)

    Amaro, Seoane, Pau; Aoudia, Sofiane; Babak, Stanislav; Binetruy, Pierre; Berti, Amanuele; Bohe, Alejandro; Caprini, Chiara; Colpi, Monica; Cornish, Neil J.; Danzmann, Karsten; hide

    2012-01-01

    This document introduces the exciting and fundamentally new science and astronomy that the European New Gravitational Wave Observatory (NGO) mission (derived from the previous LISA proposal) will deliver. The mission (which we will refer to by its informal name eLISA ) will survey for the first time the low-frequency gravitational wave band (about 0.1 mHz to 1 Hz), with sufficient sensitivity to detect interesting individual astrophysical sources out to z = 15. The measurements described here will address the basic scientific goals that have been captured in ESA s New Gravitational Wave Observatory Science Requirements Document ; they are presented here so that the wider scientific community can have access to them. The eLISA mission will discover and study a variety of cosmic events and systems with high sensitivity: coalescences of massive black holes binaries, brought together by galaxy mergers; mergers of earlier, less-massive black holes during the epoch of hierarchical galaxy and black-hole growth; stellar-mass black holes and compact stars in orbits just skimming the horizons of massive black holes in galactic nuclei of the present era; extremely compact white dwarf binaries in our Galaxy, a rich source of information about binary evolution and about future Type Ia supernovae; and possibly most interesting of all, the uncertain and unpredicted sources, for example relics of inflation and of the symmetry-breaking epoch directly after the Big Bang. eLISA s measurements will allow detailed studies of these signals with high signal-to-noise ratio, addressing most of the key scientific questions raised by ESA s Cosmic Vision programme in the areas of astrophysics and cosmology. They will also provide stringent tests of general relativity in the strong-field dynamical regime, which cannot be probed in any other way. This document not only describes the science but also gives an overview on the mission design and orbits. LISA s heritage in the eLISA design will be

  11. LISA technologies in new light: exploring alternatives for charge management and optical bench construction

    Science.gov (United States)

    Ciani, Giacomo; Chilton, Andrew; Olatunde, Taiwo; Apple, Stephen; Conklin, John W.; Mueller, Guido

    2015-08-01

    A LISA-like gravitational wave observatory is the choice candidate for ESA's L3 large mission scheduled to launch in 2034. The LISA Test Package (LTP) mission will launch later this year and test many critical technologies needed for such an observatory, among which are picometer interferometry in space and UV charge management of the Test Mass (TM). The design of these subsystems has been frozen many years ago during the final formulation of the LTP mission; since then, the LISA mission concept has evolved and new technologies have become available, making it possible to re-think the way these subsystem are implemented. With the final formulation of the L3 mission still years in the future and the LTP results expected in about one year, now is an ideal time look for areas of possible improvement and explore alternative implementations that can enhance performance, reduce costs or mitigate risks.Recently developed UV LED are lighter, cheaper and more powerful than traditional mercury lamps; in addition, their fast response time can be used to implement AC discharge techniques that can save even more space and power, and provide a more precise control of the charge.The most recent iteration of the mission baseline design allows for eliminating some of the optical components initially deemed essential; paired with the use of polarization multiplexing, this permits a redesign of the optical bench that simplifies the layout and enables a modular approach to machining and assembly, thus reducing the risks and costs associated with the current monolithic design without compromising the picometer stability of the optical path.Leveraging on extensive previous experience with LISA interferometry and the availability of a torsion pendulum-based LISA test-bed, the University of Florida LISA group is working at developing, demonstrating and optimizing both these technologies. I will describe the most recent advancements and results.

  12. Complicating Culture and Difference: Situating Asian American Youth Identities in Lisa Yee's "Millicent Min," "Girl Genius" and "Stanford Wong Flunks Big-Time"

    Science.gov (United States)

    Endo, Rachel

    2009-01-01

    This review situates how culture, difference, and identity are discursively constructed in "Millicent Min, Girl Genius" and "Stanford Wong Flunks Big-Time," two award-winning books written by critically acclaimed Asian American author Lisa Yee. Using contextual literacy approaches, the characters, cultural motifs, and physical settings in these…

  13. THE LISA GRAVITATIONAL WAVE FOREGROUND: A STUDY OF DOUBLE WHITE DWARFS

    International Nuclear Information System (INIS)

    Ruiter, Ashley J.; Belczynski, Krzysztof; Benacquista, Matthew; Williams, Gabriel; Larson, Shane L.

    2010-01-01

    Double white dwarfs (WDs) are expected to be a source of confusion-limited noise for the future gravitational wave observatory LISA. In a specific frequency range, this 'foreground noise' is predicted to rise above the instrumental noise and hinder the detection of other types of signals, e.g., gravitational waves arising from stellar-mass objects inspiraling into massive black holes. In many previous studies, only detached populations of compact object binaries have been considered in estimating the LISA gravitational wave foreground signal. Here, we investigate the influence of compact object detached and Roche-Lobe overflow (RLOF) Galactic binaries on the shape and strength of the LISA signal. Since >99% of remnant binaries that have orbital periods within the LISA sensitivity range are WD binaries, we consider only these binaries when calculating the LISA signal. We find that the contribution of RLOF binaries to the foreground noise is negligible at low frequencies, but becomes significant at higher frequencies, pushing the frequency at which the foreground noise drops below the instrumental noise to >6 mHz. We find that it is important to consider the population of mass-transferring binaries in order to obtain an accurate assessment of the foreground noise on the LISA data stream. However, we estimate that there still exists a sizeable number (∼11,300) of Galactic double WD binaries that will have a signal-to-noise ratio >5, and thus will be potentially resolvable with LISA. We present the LISA gravitational wave signal from the Galactic population of WD binaries, show the most important formation channels contributing to the LISA disk and bulge populations, and discuss the implications of these new findings.

  14. The Breadboard model of the LISA telescope assembly

    Science.gov (United States)

    Lucarelli, S.; Scheulen, D.; Kemper, D.; Sippel, R.; Verlaan, A.; Hogenhuis, H.; Ende, D.

    2017-11-01

    The primary goal of the LISA mission is the detection of gravitational waves from astronomical sources in a frequency range of 10-4 to 1 Hz. This requires operational stabilities in the picometer range as well as highly predictable mechanical distortions upon cooling down, outgassing in space, and gravity release. In March 2011 ESA announced a new way forward for the Lclass candidate missions, including LISA. ESA and the scientific community are now studying options for European-only missions that offer a significant reduction of the costs, while maintaining their core science objectives. In this context LISA has become the New Gravitational wave Observatory (NGO). Despite this reformulation, the need for dimensional stability in the picometer range remains valid, and ESA have continued the corresponding LISA Technology Development Activities (TDA's) also in view of NGO. In such frame Astrium GmbH and xperion (Friedrichshafen, Germany) have designed and manufactured an ultra-stable CFRP breadboard of the LISA telescope in order to experimentally demonstrate that the structure and the M1 & M2 mirror mounts are fulfilling the LISA requirements in the mission operational thermal environment. Suitable techniques to mount the telescope mirrors and to support the M1 & M2 mirrors have been developed, with the aim of measuring a system CTE of less than 10-7 K-1 during cooling down to -80°C. Additionally to the stringent mass and stiffness specifications, the required offset design makes the control of relative tilts and lateral displacements between the M1 and M2 mirrors particularly demanding. The thermo-elastic performance of the telescope assembly is going to be experimentally verified by TNO (Delft, The Netherlands) starting from the second half of 2012. This paper addresses challenges faced in the design phase, shows the resulting hardware and present first outcomes of the test campaign performed at TNO.

  15. Renormalized second post-Newtonian spin contributions to the accumulated orbital phase for LISA sources

    International Nuclear Information System (INIS)

    Gergely, Laszlo Arpad; Mikoczi, Balazs

    2009-01-01

    We give here a new third post-Newtonian (3PN) spin-spin contribution (in the PN parameter ε) to the accumulated orbital phase of a compact binary, arising from the spin-orbit precessional motion of the spins. In the equal mass case, this contribution vanishes, but Laser Interferometer Space Antenna (LISA) sources of merging supermassive binary black holes have typically a mass ratio of 1:10. For such nonequal masses, this 3PN correction is periodic in time, with a period approximately ε -1 times larger than the period of gravitational waves. We derive a renormalized and simpler expression of the spin-spin coefficient at 2PN, as an average over the time scale of this period of the combined 2PN and 3PN contribution. We also find that for LISA sources the quadrupole-monopole contribution to the phase dominates over the spin-spin contribution, while the self-spin contribution is negligible even for the dominant spin. Finally, we define a renormalized total spin coefficient σ to be employed in the search for gravitational waves emitted by LISA sources.

  16. Charge Management in LISA Pathfinder: The Continuous Discharging Experiment

    Science.gov (United States)

    Ewing, Becca Elizabeth

    2018-01-01

    Test mass charging is a significant source of excess force and force noise in LISA Pathfinder (LPF). The planned design scheme for mitigation of charge induced force noise in LISA is a continuous discharge by UV light illumination. We report on analysis of a charge management experiment on-board LPF conducted during December 2016. We discuss the measurement of test mass charging noise with and without continuous UV illumination, in addition to the dynamic response in the continuous discharge scheme. Results of the continuous discharge system will be discussed for their application to operating LISA with lower test mass charge.

  17. Data analysis for the LISA Technology Package

    Energy Technology Data Exchange (ETDEWEB)

    Hewitson, M; Danzmann, K; Diepholz, I; GarcIa, A [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik und Universitaet Hannover, 30167 Hannover (Germany); Armano, M; Fauste, J [European Space Agency, ESAC, Villanueva de la Canada, 28692 Madrid (Spain); Benedetti, M [Dipartimento di Ingegneria dei Materiali e Tecnologie Industriali, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Bogenstahl, J [Department of Physics and Astronomy, University of Glasgow, Glasgow (United Kingdom); Bortoluzzi, D; Bosetti, P; Cristofolini, I [Dipartimento di Ingegneria Meccanica e Strutturale, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Brandt, N [Astrium GmbH, 88039 Friedrichshafen (Germany); Cavalleri, A; Ciani, G; Dolesi, R; Ferraioli, L [Dipartimento di Fisica, Universita di Trento and INFN, Gruppo Collegato di Trento, 38050 Povo, Trento (Italy); Cruise, M [Department of Physics and Astronomy, University of Birmingham, Birmingham (United Kingdom); Fertin, D; GarcIa, C [European Space Agency, ESTEC, 2200 AG Noordwijk (Netherlands); Fichter, W, E-mail: martin.hewitson@aei.mpg.d [Institut fuer Flugmechanik und Flugregelung, 70569 Stuttgart (Germany)

    2009-05-07

    The LISA Technology Package (LTP) on board the LISA Pathfinder mission aims to demonstrate some key concepts for LISA which cannot be tested on ground. The mission consists of a series of preplanned experimental runs. The data analysis for each experiment must be designed in advance of the mission. During the mission, the analysis must be carried out promptly so that the results can be fed forward into subsequent experiments. As such a robust and flexible data analysis environment needs to be put in place. Since this software is used during mission operations and effects the mission timeline, it must be very robust and tested to a high degree. This paper presents the requirements, design and implementation of the data analysis environment (LTPDA) that will be used for analysing the data from LTP. The use of the analysis software to perform mock data challenges (MDC) is also discussed, and some highlights from the first MDC are presented.

  18. Data analysis for the LISA Technology Package

    International Nuclear Information System (INIS)

    Hewitson, M; Danzmann, K; Diepholz, I; GarcIa, A; Armano, M; Fauste, J; Benedetti, M; Bogenstahl, J; Bortoluzzi, D; Bosetti, P; Cristofolini, I; Brandt, N; Cavalleri, A; Ciani, G; Dolesi, R; Ferraioli, L; Cruise, M; Fertin, D; GarcIa, C; Fichter, W

    2009-01-01

    The LISA Technology Package (LTP) on board the LISA Pathfinder mission aims to demonstrate some key concepts for LISA which cannot be tested on ground. The mission consists of a series of preplanned experimental runs. The data analysis for each experiment must be designed in advance of the mission. During the mission, the analysis must be carried out promptly so that the results can be fed forward into subsequent experiments. As such a robust and flexible data analysis environment needs to be put in place. Since this software is used during mission operations and effects the mission timeline, it must be very robust and tested to a high degree. This paper presents the requirements, design and implementation of the data analysis environment (LTPDA) that will be used for analysing the data from LTP. The use of the analysis software to perform mock data challenges (MDC) is also discussed, and some highlights from the first MDC are presented.

  19. EDITORIAL: Proceedings of the 7th International LISA Symposium, Barcelona, Spain, 16-20 June 2008 Proceedings of the 7th International LISA Symposium, Barcelona, Spain, 16-20 June 2008

    Science.gov (United States)

    Lobo, Alberto; Sopuerta, Carlos F.

    2009-05-01

    In June 2006 the LISA International Science Team (LIST) accepted the bid presented by the Institut d'Estudis Espacials de Catalunya (IEEC) to host the 7th International LISA Symposium. This was during its 11th meeting at the University of Maryland, just before the 6th edition of the symposium started at NASA's Goddard Space Flight Center. The 7th International LISA Symposium took place in the city of Barcelona, Spain, 16-20 June, 2008, in the premises of CosmoCaixa, a modern science museum located in the hills near Tibidabo. Almost 240 delegates registered for the event, a record breaking figure compared to previous editions of the symposium. Many of the most renowned world experts in LISA, gravitational wave science, and astronomy, as well as engineers, attended LISA #7 and produced state of the art presentations, while everybody benefited from the opportunity to have live discussions during the week in a friendly environment. The programme included 31 invited plenary lectures in the mornings, and eight parallel sessions in the afternoons. These were classified into seven major areas of research: LISA Technology, LISA PathFinder, LISA PathFinder Data Analysis, LISA Data Analysis, Gravitational Wave Sources, Cosmology and Fundamental Physics with LISA and Other Gravitational Wave Detectors. Abstracts for 138 communications were received, from which a selection was made by the session convenors which would fit time constraints. Up to 63 posters completed the scientific programme. More details on the programme, including some of the talks, can be found at the symposium website:http://www.ice.cat/research/LISA_Symposium. There was, however, a remarkable add-on: Professor Clifford Will delivered a startling presentation to the general public, who completely filled the Auditori—the main conference room, 320 seats—and were invited to ask questions to the speaker who boldly guided them through the daunting world of Black Holes, Waves of Gravity, and other Warped Ideas

  20. Accreting Double White Dwarf Binaries: Implications for LISA

    International Nuclear Information System (INIS)

    Kremer, Kyle; Breivik, Katelyn; Larson, Shane L.; Kalogera, Vassiliki

    2017-01-01

    We explore the long-term evolution of mass-transferring white dwarf (WD) binaries undergoing both direct-impact and disk accretion and explore implications of such systems to gravitational-wave (GW) astronomy. We cover a broad range of initial component masses and show that these systems, the majority of which lie within the Laser Interferometer Space Antenna ( LISA ) sensitivity range, exhibit prominent negative orbital frequency evolution (chirp) for a significant fraction of their lifetimes. Using a galactic population synthesis, we predict ∼2700 of these systems will be observable with a negative chirp of 0.1 yr −2 by a space-based GW detector like LISA . We also show that detections of mass-transferring double WD systems by LISA may provide astronomers with unique ways of probing the physics governing close compact object binaries.

  1. Accreting Double White Dwarf Binaries: Implications for LISA

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, Kyle; Breivik, Katelyn; Larson, Shane L.; Kalogera, Vassiliki, E-mail: kremer@u.northwestern.edu, E-mail: katelyn.breivik@northwestern.edu, E-mail: vicky@northwestern.edu, E-mail: s.larson@northwestern.edu [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, Northwestern University 2145 Sheridan Road, Evanston, IL 60201 (United States)

    2017-09-10

    We explore the long-term evolution of mass-transferring white dwarf (WD) binaries undergoing both direct-impact and disk accretion and explore implications of such systems to gravitational-wave (GW) astronomy. We cover a broad range of initial component masses and show that these systems, the majority of which lie within the Laser Interferometer Space Antenna ( LISA ) sensitivity range, exhibit prominent negative orbital frequency evolution (chirp) for a significant fraction of their lifetimes. Using a galactic population synthesis, we predict ∼2700 of these systems will be observable with a negative chirp of 0.1 yr{sup −2} by a space-based GW detector like LISA . We also show that detections of mass-transferring double WD systems by LISA may provide astronomers with unique ways of probing the physics governing close compact object binaries.

  2. Accreting Double White Dwarf Binaries: Implications for LISA

    Science.gov (United States)

    Kremer, Kyle; Breivik, Katelyn; Larson, Shane L.; Kalogera, Vassiliki

    2017-09-01

    We explore the long-term evolution of mass-transferring white dwarf (WD) binaries undergoing both direct-impact and disk accretion and explore implications of such systems to gravitational-wave (GW) astronomy. We cover a broad range of initial component masses and show that these systems, the majority of which lie within the Laser Interferometer Space Antenna (LISA) sensitivity range, exhibit prominent negative orbital frequency evolution (chirp) for a significant fraction of their lifetimes. Using a galactic population synthesis, we predict ˜2700 of these systems will be observable with a negative chirp of 0.1 yr-2 by a space-based GW detector like LISA. We also show that detections of mass-transferring double WD systems by LISA may provide astronomers with unique ways of probing the physics governing close compact object binaries.

  3. Distinguishing Between Formation Channels for Binary Black Holes with LISA

    Science.gov (United States)

    Breivik, Katelyn; Rodriguez, Carl L.; Larson, Shane L.; Kalogera, Vassiliki; Rasio, Frederic A.

    2017-01-01

    The recent detections of GW150914 and GW151226 imply an abundance of stellar-mass binary-black-hole mergers in the local universe. While ground-based gravitational-wave detectors are limited to observing the final moments before a binary merges, space-based detectors, such as the Laser Interferometer Space Antenna (LISA), can observe binaries at lower orbital frequencies where such systems may still encode information about their formation histories. In particular, the orbital eccentricity and mass of binary black holes in the LISA frequency band can be used together to discriminate between binaries formed in isolation in galactic fields and those formed in dense stellar environments such as globular clusters. In this letter, we explore the orbital eccentricity and mass of binary-black-hole populations as they evolve through the LISA frequency band. Overall we find that there are two distinct populations discernible by LISA. We show that up to ~90% of binaries formed either dynamically or in isolation have eccentricities measurable by LISA. Finally, we note how measured eccentricities of low-mass binary black holes evolved in isolation could provide detailed constraints on the physics of black-hole natal kicks and common-envelope evolution.

  4. A study on the radionuclide migration by means of the code LISA

    International Nuclear Information System (INIS)

    Frenquellucci, F.; Deserti, M.

    1989-01-01

    LISA code (Long Term Isolation Safety Assessment) has been developed by J.R.C. EUROATOM Ispra (Radiochemistry Division) and it's utilized in order to study migration of radionuclides through porous media. Aim of the present work is to analyze LISA's input and output files. A brief description of the code is also performed. As LISA is a research and in development code, its structure is rather complex and an exhaustive description of input/output files is helpful for the user. Version 3 of LISA code, loaded on ENEA's IBM 3090, is avaylable by ENEA-VEL Bologna

  5. Data analysis and source modelling for LISA

    International Nuclear Information System (INIS)

    Shang, Yu

    2014-01-01

    The gravitational waves are one of the most important predictions in general relativity. Besides of the directly proof of the existence of GWs, there are already several ground based detectors (such as LIGO, GEO, etc) and the planed future space mission (such as: LISA) which are aim to detect the GWs directly. GW contain a large amount of information of its source, extracting these information can help us dig out the physical property of the source, even open a new window for understanding the Universe. Hence, GW data analysis will be a challenging task in seeking the GWs. In this thesis, I present two works about the data analysis for LISA. In the first work, we introduce an extended multimodal genetic algorithm which utilizes the properties of the signal and the detector response function to analyze the data from the third round of mock LISA data challenge. We have found all five sources present in the data and recovered the coalescence time, chirp mass, mass ratio and sky location with reasonable accuracy. As for the orbital angular momentum and two spins of the Black Holes, we have found a large number of widely separated modes in the parameter space with similar maximum likelihood values. The performance of this method is comparable, if not better, to already existing algorithms. In the second work, we introduce an new phenomenological waveform model for the extreme mass ratio inspiral system. This waveform consists of a set of harmonics with constant amplitude and slowly evolving phase which we decompose in a Taylor series. We use these phenomenological templates to detect the signal in the simulated data, and then, assuming a particular EMRI model, estimate the physical parameters of the binary with high precision. The results show that our phenomenological waveform is very feasible in the data analysis of EMRI signal.

  6. Possible LISA follow-on mission scientific objectives

    International Nuclear Information System (INIS)

    Bender, Peter L; Begelman, Mitchell C; Gair, Jonathan R

    2013-01-01

    A major objective that has been suggested for a follow-on mission to a Laser Interferometer Space Antenna (LISA)-type mission is to investigate more completely how intermediate mass black holes were formed and grew in the early universe, before they evolved into the much more massive black holes at the centers of many galaxies today. The actual design of such a follow-on mission will of course depend on what is observed by a LISA-type mission, such as the recently modified proposal for an evolved LISA mission, with the interferometer arm lengths between spacecraft reduced from 5 million to 1 million km. However, the sensitivity goals of a follow-on mission are likely to be influenced strongly by the desire to be able to see mergers of 10 M ⊙ black holes with roughly 3000 M ⊙ or larger intermediate mass black holes out to as large redshifts as possible. Approximate calculations of the expected signal-to-noise have been made for a possible LISA follow-on mission that was suggested about eight years ago (Bender and Begelman 2005 Trends in Space Science and Cosmic Vision 2020 (Noordwijk: ESA Publications Division) pp 33–38), and was called the Advanced Laser Interferometer Antenna. Based on the calculations, it appears that detections out to a redshift of 10 would be possible for 10 M ⊙ black holes spiraling into perhaps 5000 M ⊙ or larger intermediate mass black holes if the extragalactic gravitational wave background due to close white dwarf binaries is in the currently estimated range. (paper)

  7. T.D Lee and Lisa Randall visit ATLAS

    CERN Multimedia

    Pauline Gagnon

    Professor Tsung-Dao Lee, who received the Nobel Prize for Physics in 1957 for postulating that parity is not conserved in weak interactions, visited the ATLAS detector this month. He is seen here in the company of Peter Jenni, spokesperson for ATLAS. T.D. Lee is still very active at over 80, pursuing his theory work to this day. Professor Lisa Randall from Harvard University, the well-known theorist behind the Randall-Sundrum theory for extra dimensions, was also part of the group visiting the ATLAS detector. She is seen here with Fabiola Gianotti, deputy spokesperson for ATLAS. Lisa Randall's two initial papers have been quoted both more than 2500 times, making her the most cited theoretical physicist in the world in the last five years as of last autumn - a total of about 10,000 citations! One wonders here if Peter is pointing to a CP-violating graviton spotted in the ATLAS cavern... From left to right: Fabiola Gianotti, Gustaaf Brooijmans, convener of the ATLAS Exotics physics gro...

  8. Interferometry for the LISA technology package LTP: an update

    International Nuclear Information System (INIS)

    Heinzel, G; Bogenstahl, J; Braxmaier, C; Danzmann, K; Garcia, A; Guzman, F; Hough, J; Hoyland, D; Jennrich, O; Killow, C; Robertson, D; Sodnik, Z; Steier, F; Ward, H; Wand, V

    2006-01-01

    This paper gives an update on the status of the LISA technology package (LTP) which is to be launched in 2009 by ESA as a technology demonstration mission for the spaceborne gravitational wave observatory LISA. The dominant noise source in the interferometer prototype has been investigated and improved such that it is now comfortably below its budget at all frequencies

  9. Constraining stellar binary black hole formation scenarios with eLISA eccentricity measurements

    Science.gov (United States)

    Nishizawa, Atsushi; Sesana, Alberto; Berti, Emanuele; Klein, Antoine

    2017-03-01

    A space-based interferometer such as the evolved Laser Interferometer Space Antenna (eLISA) could observe a few to a few thousands of progenitors of black hole binaries (BHBs) similar to those recently detected by Advanced LIGO. Gravitational radiation circularizes the orbit during inspiral, but some BHBs retain a measurable eccentricity at the low frequencies where eLISA is the most sensitive. The eccentricity of a BHB carries precious information about its formation channel: BHBs formed in the field, in globular clusters, or close to a massive black hole (MBH) have distinct eccentricity distributions in the eLISA band. We generate mock eLISA observations, folding in measurement errors, and using a Bayesian model selection, we study whether eLISA measurements can identify the BHB formation channel. We find that a handful of observations would suffice to tell whether BHBs were formed in the gravitational field of an MBH. Conversely, several tens of observations are needed to tell apart field formation from globular cluster formation. A 5-yr eLISA mission with the longest possible armlength is desirable to shed light on BHB formation scenarios.

  10. 240 nm UV LEDs for LISA test mass charge control

    Science.gov (United States)

    Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Serra, Paul; Ciani, Giacomo; Mueller, Guido; Conklin, John

    2015-05-01

    Test Masses inside the LISA Gravitational Reference Sensor must maintain almost pure geodesic motion for gravitational waves to be successfully detected. LISA requires residual test mass accelerations below 3 fm/s2/√Hz at all frequencies between 0.1 and 3 mHz. One of the well-known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electromagnetic fields. LISA Pathfinder will use Hg-discharge lamps emitting mostly around 254 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. Presented here is a preliminary study of the effectiveness of charge control using latest generation UV-LEDs which produce light at 240 nm with energy above the work function of pure Au. Their lower mass, better power efficiency and small size make them an ideal replacement for Hg lamps.

  11. 240 nm UV LEDs for LISA test mass charge control

    International Nuclear Information System (INIS)

    Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Serra, Paul; Ciani, Giacomo; Mueller, Guido; Conklin, John

    2015-01-01

    Test Masses inside the LISA Gravitational Reference Sensor must maintain almost pure geodesic motion for gravitational waves to be successfully detected. LISA requires residual test mass accelerations below 3 fm/s 2 /√Hz at all frequencies between 0.1 and 3 mHz. One of the well-known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electromagnetic fields. LISA Pathfinder will use Hg-discharge lamps emitting mostly around 254 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. Presented here is a preliminary study of the effectiveness of charge control using latest generation UV-LEDs which produce light at 240 nm with energy above the work function of pure Au. Their lower mass, better power efficiency and small size make them an ideal replacement for Hg lamps. (paper)

  12. The LISA Pathfinder DMU and Radiation Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Canizares, P; Conchillo, A; Gesa, L; Lloro, I; Lobo, A; Mateos, I; Sopuerta, Carlos F [Institut de Ciencies de l' Espai, CSIC, Facultat de Ciencies, Torre C5 parell, 08193 Bellaterra (Spain); Chmeissani, M [Institut de Fisica d' Altes Energies (IFAE), Edifici CN, UAB Campus, 08193 Bellaterra (Spain); Diaz-Aguilo, M; GarcIa-Berro, E; Gibert, F [Institut d' Estudis Espacials de Catalunya (IEEC), Edifici Nexus, Gran Capita 2-4, 08034 Barcelona (Spain); Grimani, C [Universita degli Studi di Urbino, MFI Department, Via Santa Chiara 27, 61029 Urbino, and INFN Florence (Italy); Nofrarias, M [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, D-30167 Hannover (Germany); Ramos-Castro, J [Departament d' Enginyeria Electronica, UPC, Campus Nord, Edifici C4, Jordi Girona 1-3, 08034 Barcelona (Spain); Sanjuan, J [Department of Physics, University of Florida, NPB-22258 PO Box 118 440, Gainesville, FL 32611-8440 (United States); Araujo, H M; Wass, P, E-mail: lobo@ieec.fcr.es [High Energy Physics Blackett Laboratory, Prince Consort Road, Imperial College London, London SW7 2BW (United Kingdom)

    2011-05-07

    The LISA Pathfinder DMU (Data Management Unit) flight model was formally accepted by ESA and ASD on 11 February 2010, after all hardware and software tests had been successfully completed. The diagnostics items are scheduled to be delivered by the end of 2010. In this paper, we review the requirements and performance of this instrumentation, specially focusing on the Radiation Monitor and the DMU, as well as the status of their programmed use during mission operations, on which work is ongoing at the time of writing.

  13. Inference on inspiral signals using LISA MLDC data

    International Nuclear Information System (INIS)

    Roever, Christian; Stroeer, Alexander; Bloomer, Ed; Christensen, Nelson; Clark, James; Hendry, Martin; Messenger, Chris; Meyer, Renate; Pitkin, Matt; Toher, Jennifer; Umstaetter, Richard; Vecchio, Alberto; Veitch, John; Woan, Graham

    2007-01-01

    In this paper, we describe a Bayesian inference framework for the analysis of data obtained by LISA. We set up a model for binary inspiral signals as defined for the Mock LISA Data Challenge 1.2 (MLDC), and implemented a Markov chain Monte Carlo (MCMC) algorithm to facilitate exploration and integration of the posterior distribution over the nine-dimensional parameter space. Here, we present intermediate results showing how, using this method, information about the nine parameters can be extracted from the data

  14. The Engineering of LISA Pathfinder – the quietest Laboratory ever flown in Space

    International Nuclear Information System (INIS)

    Trenkel, Christian; Wealthy, Dave; Dunbar, Neil; Warren, Carl; Schleicher, Alexander; Ziegler, Tobias; Brandt, Nico; Gerndt, Rüdiger

    2017-01-01

    We review the engineering approach adopted to ensure the required gravitational, magnetic, thermal and residual acceleration stability on-board LISA Pathfinder, and present the in-flight results that have been achieved. Arguably, this stability makes LISA Pathfinder the quietest laboratory ever flown in space. The implications for LISA are also discussed. (paper)

  15. Lisa's Lemonade Stand: Exploring Algebraic Ideas.

    Science.gov (United States)

    Billings, Esther M. H.; Lakatos, Tracy

    2003-01-01

    Presents an activity, "Lisa's Lemonade Stand," that actively engages students in algebraic thinking as they analyze change by investigating relationships between variables and gain experience describing and representing these relationships graphically. (YDS)

  16. LISA Pathfinder: hardware tests and their input to the mission

    Science.gov (United States)

    Audley, Heather

    The Laser Interferometer Space Antenna (LISA) is a joint ESA-NASA mission for the first space-borne gravitational wave detector. LISA aims to detect sources in the 0.1mHz to 1Hz range, which include supermassive black holes and galactic binary stars. Core technologies required for the LISA mission, including drag-free test mass control, picometre interferometry and micro-Newton thrusters, cannot be tested on-ground. Therefore, a precursor satellite, LISA Pathfinder, has been developed as a technology demonstration mission. The preparations for the LISA Pathfinder mission have reached an exciting stage. Tests of the engineering model of the optical metrology system have recently been completed at the Albert Einstein Institute, Hannover, and flight model tests are now underway. Significantly, they represent the first complete integration and testing of the space-qualified hardware and are the first tests on system level. The results and test procedures of these campaigns will be utilised directly in the ground-based flight hardware tests, and subsequently within in-flight operations. In addition, they allow valuable testing of the data analysis methods using the MatLab based LTP data analysis toolbox. This contribution presents an overview of the test campaigns calibration, control and perfor-mance results, focusing on the implications for the Experimental Master Plan which provides the basis for the in-flight operations and procedures.

  17. Data Analysis for the LISA Pathfinder Mission

    Science.gov (United States)

    Thorpe, James Ira

    2009-01-01

    The LTP (LISA Technology Package) is the core part of the Laser Interferometer Space Antenna (LISA) Pathfinder mission. The main goal of the mission is to study the sources of any disturbances that perturb the motion of the freely-falling test masses from their geodesic trajectories as well as 10 test various technologies needed for LISA. The LTP experiment is designed as a sequence of experimental runs in which the performance of the instrument is studied and characterized under different operating conditions. In order to best optimize subsequent experimental runs, each run must be promptly analysed to ensure that the following ones make best use of the available knowledge of the instrument ' In order to do this, all analyses must be designed and tested in advance of the mission and have sufficient built-in flexibility to account for unexpected results or behaviour. To support this activity, a robust and flexible data analysis software package is also required. This poster presents two of the main components that make up the data analysis effort: the data analysis software and the mock-data challenges used to validate analysis procedures and experiment designs.

  18. LISA Pathfinder instrument data analysis

    Science.gov (United States)

    Guzman, Felipe

    LISA Pathfinder (LPF) is an ESA-launched demonstration mission of key technologies required for the joint NASA-ESA gravitational wave observatory in space, LISA. As part of the LPF interferometry investigations, analytic models of noise sources and corresponding noise subtrac-tion techniques have been developed to correct for effects like the coupling of test mass jitter into displacement readout, and fluctuations of the laser frequency or optical pathlength difference. Ground testing of pre-flight hardware of the Optical Metrology Subsystem is currently ongoing at the Albert Einstein Institute Hannover. In collaboration with NASA Goddard Space Flight Center, the LPF mission data analysis tool LTPDA is being used to analyze the data product of these tests. Furthermore, the noise subtraction techniques and in-flight experiment runs for noise characterization are being defined as part of the mission experiment master plan. We will present the data analysis outcome of pre-flight hardware ground tests and possible noise subtraction strategies for in-flight instrument operations.

  19. LISA Mission and System architectures and performances

    International Nuclear Information System (INIS)

    Gath, Peter F; Weise, Dennis; Schulte, Hans-Reiner; Johann, Ulrich

    2009-01-01

    In the context of the LISA Mission Formulation Study, the LISA System was studied in detail and a new baseline architecture for the whole mission was established. This new baseline is the result of trade-offs on both, mission and system level. The paper gives an overview of the different mission scenarios and configurations that were studied in connection with their corresponding advantages and disadvantages as well as performance estimates. Differences in the required technologies and their influence on the overall performance budgets are highlighted for all configurations. For the selected baseline concept, a more detailed description of the configuration is given and open issues in the technologies involved are discussed.

  20. LISA Mission and System architectures and performances

    Energy Technology Data Exchange (ETDEWEB)

    Gath, Peter F; Weise, Dennis; Schulte, Hans-Reiner; Johann, Ulrich, E-mail: peter.gath@astrium.eads.ne [Astrium GmbH Satellites, 88039 Friedrichshafen (Germany)

    2009-03-01

    In the context of the LISA Mission Formulation Study, the LISA System was studied in detail and a new baseline architecture for the whole mission was established. This new baseline is the result of trade-offs on both, mission and system level. The paper gives an overview of the different mission scenarios and configurations that were studied in connection with their corresponding advantages and disadvantages as well as performance estimates. Differences in the required technologies and their influence on the overall performance budgets are highlighted for all configurations. For the selected baseline concept, a more detailed description of the configuration is given and open issues in the technologies involved are discussed.

  1. Possible Periodic Orbit Control Maneuvers for an eLISA Mission

    Science.gov (United States)

    Bender, Peter L.; Welter, Gary L.

    2012-01-01

    This paper investigates the possible application of periodic orbit control maneuvers for so-called evolved-LISA (eLISA) missions, i.e., missions for which the constellation arm lengths and mean distance from the Earth are substantially reduced. We find that for missions with arm lengths of 106 km and Earth-trailing distance ranging from approx. 12deg to 20deg over the science lifetime, the occasional use of the spacecraft micro-Newton thrusters for constellation configuration maintenance should be able to essentially eliminate constellation distortion caused by Earth-induced tidal forces at a cost to science time of only a few percent. With interior angle variation kept to approx. +/-0:1deg, the required changes in the angles between the laser beam pointing directions for the two arms from any spacecraft could be kept quite small. This would considerably simplify the apparatus necessary for changing the transmitted beam directions.

  2. Bayesian statistics for the calibration of the LISA Pathfinder experiment

    International Nuclear Information System (INIS)

    Armano, M; Freschi, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

    2015-01-01

    The main goal of LISA Pathfinder (LPF) mission is to estimate the acceleration noise models of the overall LISA Technology Package (LTP) experiment on-board. This will be of crucial importance for the future space-based Gravitational-Wave (GW) detectors, like eLISA. Here, we present the Bayesian analysis framework to process the planned system identification experiments designed for that purpose. In particular, we focus on the analysis strategies to predict the accuracy of the parameters that describe the system in all degrees of freedom. The data sets were generated during the latest operational simulations organised by the data analysis team and this work is part of the LTPDA Matlab toolbox. (paper)

  3. E. Yiannopoulou on Lisa Blackman’s The Body.

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available Blackman, Lisa. The Body. Oxford and New York: Berg, 2008. 160 pp. “Is there anything natural about the human body?” (1. This is how Lisa Blackman begins her all too daunting task of reviewing and critically evaluating what has come to be known as “body theory” in the field of sociology. Carefully picking her way among numerous theories on the corporeal that have been produced across the humanities in the last twenty years, Blackman lays out her problematic from the start by asking to know w...

  4. PREFACE: Proceedings of the 7th International LISA Symposium, Barcelona, Spain, 16-20 June 2008

    Science.gov (United States)

    Lobo, Alberto; Sopuerta, Carlos F.

    2009-07-01

    In June 2006 the LISA International Science Team (LIST) accepted the bid presented by the Institut d'Estudis Espacials de Catalunya (IEEC) to host the 7th International LISA Symposium. This was during its 11th meeting at the University of Maryland, just before the 6th edition of the Symposium started in NASA's Goddard Space Flight Center. The 7th International LISA Symposium took place at the city of Barcelona, Spain, from 16-20 June 2008, in the premises of CosmoCaixa, a modern Science Museum located in the hills near Tibidabo. Almost 240 delegates registered for the event, a record breaking figure compared to previous editions of the Symposium. Many of the most renowned world experts in LISA, Gravitational Wave Science, and Astronomy, as well as Engineers, attended LISA 7 and produced state-of-the-art presentations, while everybody benefited from the opportunity to have live discussions during the week in a friendly environment. The programme included 31 invited plenary lectures in the mornings, and 8 parallel sessions in the afternoons. These were classified into 7 major areas of research: LISA Technology, LISA PathFinder, LISA PathFinder Data Analysis, LISA Data Analysis, Gravitational Wave sources, Cosmology and Fundamental Physics with LISA and Other Gravitational Wave Detectors. 138 abstracts for communications were received, of which a selection was made by the session convenors which would fit time constraints. Up to 63 posters completed the scientific programme. More details on the programme, including some of the talks, can be found at the Symposium website: http://www.ice.cat/research/LISA_Symposium. There was however a remarkable add-on: Professor Clifford Will delivered a startling presentation to the general public, who completely filled the Auditori—the main Conference Room, 320 seats—and were invited to ask questions to the speaker who had boldly guided them through the daunting world of Black Holes, Waves of Gravity, and other Warped Ideas of

  5. Report on the first round of the Mock LISA Data Challenges

    International Nuclear Information System (INIS)

    Arnaud, K A; Auger, G; Babak, S

    2007-01-01

    The Mock LISA Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data analysis tools and capabilities, and demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data output. The first round of MLDCs has just been completed: nine challenges consisting of data sets containing simulated gravitational-wave signals produced either by galactic binaries or massive black hole binaries embedded in simulated LISA instrumental noise were released in June 2006 with deadline for submission of results at the beginning of December 2006. Ten groups have participated in this first round of challenges. All of the challenges had at least one entry which successfully characterized the signal to better than 95% when assessed via a correlation with phasing ambiguities accounted for. Here, we describe the challenges, summarize the results and provide a first critical assessment of the entries

  6. Prospects of eLISA for Detecting Galactic Binary Black Holes Similar to GW150914

    OpenAIRE

    Seto, Naoki

    2016-01-01

    We discuss the prospects of eLISA for detecting gravitational waves (GWs) from Galactic binary black holes (BBHs) similar to GW150914. For a comoving merger rate that is consistent with current observation, eLISA is likely to identify at least one BBH with a sufficient signal-to-noise ratio. In addition, eLISA has a potential to measure the eccentricity of the BBH as small as $e\\sim 0.02$, corresponding to the residual value $e\\sim 10^{-6}$ at 10Hz. Therefore, eLISA could provide us with a cr...

  7. Mona Lisa, lesbiahvid ja seksilaulud / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2003-01-01

    Ameerika Teaduse Edendamise Assotsiatsiooni (AAA) konverentsil esitatud uusimatest teadusuuringutest. Artiklid: Mona Lisa naeratuse saladus paljastatud ; Lesbilised Jaapani makaagid seljatavad Darwini ; Linnud õpivad uusi laule uue partneri leidmiseks

  8. Low-Frequency Gravitational-Wave Science with eLISA/ NGO

    Science.gov (United States)

    Amaro-Seoane, Pau; Aoudia, Sofiane; Babak, Stanislav; Binetruy, Pierre; Berti, Emanuele; Bohe, Alejandro; Caprini, Chiara; Colpi, Monica; Cornish, Neil J.; Danzmann, Karsten; hide

    2011-01-01

    We review the expected science performance of the New Gravitational-Wave Observatory (NGO, a.k.a. eLISA), a mission under study by the European Space Agency for launch in the early 2020s. eLISA will survey the low-frequency gravitational-wave sky (from 0.1 mHz to 1 Hz), detecting and characterizing a broad variety of systems and events throughout the Universe, including the coalescences of massive black holes brought together by galaxy mergers; the inspirals of stellar-mass black holes and compact stars into central galactic black holes; several millions of ultracompact binaries, both detached and mass transferring, in the Galaxy; and possibly unforeseen sources such as the relic gravitational-wave radiation from the early Universe. eLISA's high signal-to-noise measurements will provide new insight into the structure and history of the Universe, and they will test general relativity in its strong-field dynamical regime.

  9. Observing a Gravitational Wave Background With Lisa

    National Research Council Canada - National Science Library

    Tinto, M; Armstrong, J; Estabrook, F

    2000-01-01

    ... formation of several observables. All are independent of lasers and frequency standard phase fluctuations, but have different couplings to gravitational waves and to the various LISA instrumental noises...

  10. Beyond the Required LISA Free-Fall Performance: New LISA Pathfinder Results down to 20 μ Hz

    Science.gov (United States)

    Armano, M.; Audley, H.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Castelli, E.; Cavalleri, A.; Cesarini, A.; Cruise, A. M.; Danzmann, K.; de Deus Silva, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E. D.; Freschi, M.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Grzymisch, J.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C. J.; Lobo, J. A.; Lloro, I.; Liu, L.; López-Zaragoza, J. P.; Maarschalkerweerd, R.; Mance, D.; Meshksar, N.; Martín, V.; Martin-Polo, L.; Martino, J.; Martin-Porqueras, F.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mendes, L.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Ramos-Castro, J.; Reiche, J.; Robertson, D. I.; Rivas, F.; Russano, G.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J. I.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Wass, P. J.; Weber, W. J.; Wissel, L.; Wittchen, A.; Zweifel, P.

    2018-02-01

    In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20 μ Hz . The Letter presents the measured differential acceleration noise figure, which is at (1.74 ±0.01 ) fm s-2/√{Hz } above 2 mHz and (6 ±1 ) ×10 fm s-2/√{Hz } at 20 μ Hz , and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency.

  11. LISA Pathfinder: Optical Metrology System monitoring during operations

    Science.gov (United States)

    Audley, Heather E.; LISA Pathfinder Collaboration

    2017-05-01

    The LISA Pathfinder (LPF) mission has demonstrated excellent performance. In addition to having surpassed the main mission goals, data has been collected from the various subsystems throughout the duration of the mission. This data is a valuable resource, both for a more complete understanding of the LPF satellite and the differential acceleration measurements, as well as for the design of the future Laser Interferometer Space Antenna (LISA) mission. Initial analysis of the Optical Metrology System (OMS) data was performed as part of daily system monitoring, and more in-depth analyses are ongoing. This contribution presents an overview of these activities along with an introduction to the OMS.

  12. LISA data analysis using Markov chain Monte Carlo methods

    International Nuclear Information System (INIS)

    Cornish, Neil J.; Crowder, Jeff

    2005-01-01

    The Laser Interferometer Space Antenna (LISA) is expected to simultaneously detect many thousands of low-frequency gravitational wave signals. This presents a data analysis challenge that is very different to the one encountered in ground based gravitational wave astronomy. LISA data analysis requires the identification of individual signals from a data stream containing an unknown number of overlapping signals. Because of the signal overlaps, a global fit to all the signals has to be performed in order to avoid biasing the solution. However, performing such a global fit requires the exploration of an enormous parameter space with a dimension upwards of 50 000. Markov Chain Monte Carlo (MCMC) methods offer a very promising solution to the LISA data analysis problem. MCMC algorithms are able to efficiently explore large parameter spaces, simultaneously providing parameter estimates, error analysis, and even model selection. Here we present the first application of MCMC methods to simulated LISA data and demonstrate the great potential of the MCMC approach. Our implementation uses a generalized F-statistic to evaluate the likelihoods, and simulated annealing to speed convergence of the Markov chains. As a final step we supercool the chains to extract maximum likelihood estimates, and estimates of the Bayes factors for competing models. We find that the MCMC approach is able to correctly identify the number of signals present, extract the source parameters, and return error estimates consistent with Fisher information matrix predictions

  13. Sensitivity and parameter-estimation precision for alternate LISA configurations

    International Nuclear Information System (INIS)

    Vallisneri, Michele; Crowder, Jeff; Tinto, Massimo

    2008-01-01

    We describe a simple framework to assess the LISA scientific performance (more specifically, its sensitivity and expected parameter-estimation precision for prescribed gravitational-wave signals) under the assumption of failure of one or two inter-spacecraft laser measurements (links) and of one to four intra-spacecraft laser measurements. We apply the framework to the simple case of measuring the LISA sensitivity to monochromatic circular binaries, and the LISA parameter-estimation precision for the gravitational-wave polarization angle of these systems. Compared to the six-link baseline configuration, the five-link case is characterized by a small loss in signal-to-noise ratio (SNR) in the high-frequency section of the LISA band; the four-link case shows a reduction by a factor of √2 at low frequencies, and by up to ∼2 at high frequencies. The uncertainty in the estimate of polarization, as computed in the Fisher-matrix formalism, also worsens when moving from six to five, and then to four links: this can be explained by the reduced SNR available in those configurations (except for observations shorter than three months, where five and six links do better than four even with the same SNR). In addition, we prove (for generic signals) that the SNR and Fisher matrix are invariant with respect to the choice of a basis of TDI observables; rather, they depend only on which inter-spacecraft and intra-spacecraft measurements are available

  14. Weak-light phase locking for LISA

    International Nuclear Information System (INIS)

    McNamara, Paul W

    2005-01-01

    The long armlengths of the LISA interferometer, and the finite aperture of the telescope, lead to an optical power attenuation of ∼10 -10 of the transmitted to received light. Simple reflection at the end of the arm is therefore not an optimum interferometric design. Instead, a local laser is offset phase locked to the weak incoming beam, transferring the phase information of the incoming to the outgoing light. This paper reports on an experiment to characterize a weak-light phase-locking scheme suitable for LISA in which a diode-pumped, Nd:YAG, non-planar ring oscillator (NPRO) is offset phase locked to a low-power (13 pW) frequency stabilized master NPRO. Preliminary results of the relative phase noise of the slave laser shows shot noise limited performance above 0.4 Hz. Excess noise is observed at lower frequencies, most probably due to thermal effects in the optical arrangement and phase-sensing electronics

  15. Detection of Micrometeoroids with LISA Pathfinder

    Science.gov (United States)

    Thorpe, Ira; Littenberg, Tyson; Janchez, Diego; Baker, John; The LISA Pathfinder Team Team

    2017-01-01

    The LISA Pathfinder mission (LPF), a joint ESA/NASA technology demonstration mission currently operating at the Sun-Earth L1 point, contains the most precise accelerometry system ever flown. Analysis suggests that LPF should have sufficient sensitivity to detect impacts of small micrometeoroids and dust through their transfer of momentum to the spacecraft. Moreover, LPF's ability to fully resolve both the linear and angular momentum transfer in three dimensions allows a magnitude, direction, and location to be estimated for each impact. We present preliminary results from a systematic search of the LISA Pathfinder data for such impacts and discuss the prospects for using these and future results to inform models of the formation and evolution of dust populations in the inner solar system. These models have wide applicability to both pure and applied space science, ranging from the physics of planet formation and dynamics of minor Solar System bodies to estimates of the micrometeorite hazard for future spacecraft. 2017 NASA Science Innovation Fund.

  16. LISA Sources in Milky Way Globular Clusters

    Science.gov (United States)

    Kremer, Kyle; Chatterjee, Sourav; Breivik, Katelyn; Rodriguez, Carl L.; Larson, Shane L.; Rasio, Frederic A.

    2018-05-01

    We explore the formation of double-compact-object binaries in Milky Way (MW) globular clusters (GCs) that may be detectable by the Laser Interferometer Space Antenna (LISA). We use a set of 137 fully evolved GC models that, overall, effectively match the properties of the observed GCs in the MW. We estimate that, in total, the MW GCs contain ˜21 sources that will be detectable by LISA. These detectable sources contain all combinations of black hole (BH), neutron star, and white dwarf components. We predict ˜7 of these sources will be BH-BH binaries. Furthermore, we show that some of these BH-BH binaries can have signal-to-noise ratios large enough to be detectable at the distance of the Andromeda galaxy or even the Virgo cluster.

  17. LISA extreme-mass-ratio inspiral events as probes of the black hole mass function

    International Nuclear Information System (INIS)

    Gair, Jonathan R.; Tang, Christopher; Volonteri, Marta

    2010-01-01

    One of the sources of gravitational waves for the proposed space-based gravitational wave detector, the Laser Interferometer Space Antenna (LISA), are the inspirals of compact objects into supermassive black holes in the centers of galaxies--extreme-mass-ratio inspirals (EMRIs). Using LISA observations, we will be able to measure the parameters of each EMRI system detected to very high precision. However, the statistics of the set of EMRI events observed by LISA will be more important in constraining astrophysical models than extremely precise measurements for individual systems. The black holes to which LISA is most sensitive are in a mass range that is difficult to probe using other techniques, so LISA provides an almost unique window onto these objects. In this paper we explore, using Bayesian techniques, the constraints that LISA EMRI observations can place on the mass function of black holes at low redshift. We describe a general framework for approaching inference of this type--using multiple observations in combination to constrain a parametrized source population. Assuming that the scaling of the EMRI rate with the black-hole mass is known and taking a black-hole distribution given by a simple power law, dn/dlnM=A 0 (M/M * ) α 0 , we find that LISA could measure the parameters to a precision of Δ(lnA 0 )∼0.08, and Δ(α 0 )∼0.03 for a reference model that predicts ∼1000 events. Even with as few as 10 events, LISA should constrain the slope to a precision ∼0.3, which is the current level of observational uncertainty in the low-mass slope of the black-hole mass function. We also consider a model in which A 0 and α 0 evolve with redshift, but find that EMRI observations alone do not have much power to probe such an evolution.

  18. LISA Pathfinder: An important first step towards a space-based gravitational wave observatory

    Science.gov (United States)

    Thorpe, James

    2017-08-01

    ESA's LISA Pathfinder mission was launched on Dec 3rd, 2015 and completed earlier this Summer. During this relatively short mission, Pathfinder at its two science payloads, Europe's LISA Technology Package and NASA's Disturbance Reduction System, demonstrated several techniques and technologies that enable development of a future space-based gravitational wave observatory. Most notably, Pathfinder demonstrated that the technique of drag-free flight could be utilized to place a test mass in near-perfect free-fall, with residual accelerations at the femto-g level in the milliHertz band. Additionally, technologies such as precision bonded optical structures for metrology, micropropulsion systems, and non-contact charge control, were successfully tested, retiring risk for LISA. In this talk, I will present an overview of Pathfinder's results to date and some perspective on how this success will be leveraged into realizing LISA.

  19. Study of test-mass charging process in the LISA missions due to diffuse γ-rays

    International Nuclear Information System (INIS)

    Finetti, N; Scrimaglio, R; Grimani, C; Fabi, M

    2009-01-01

    Gravitational inertial sensors will be placed on board the Laser Interferometer Space Antenna (LISA) and aboard its precursor mission LISA Pathfinder (LISA-PF) in order to detect low frequency gravitational waves in space. Free-floating test-masses (Au 7 Pt 3 cubes) will be housed in inertial sensors for detecting possible laser signal variations induced by gravitational waves. Charging of the LISA test-masses due to exposure of the spacecraft to cosmic radiation and energetic solar particles will affect operation of gravitational inertial sensors. In this paper we report on the role of diffuse γ-rays in charging the LISA and LISA-PF test-masses with respect to protons and helium nuclei. The diffuse γ-ray flux in the Galaxy has been interpolated taking into account the outcomes of recent calculations. A comparison with γ-ray observations gathered by different experiments (COMPTEL and EGRET, Milagro, Whipple, HEGRA, TIBET) has been carried out. Simulations of the test-mass charging process have been performed by means of the FLUKA2006.3b package. Monte Carlo simulations of the interaction of cosmic particles with the LISA spacecraft indicate that the diffuse γ-ray contribution to the average steady-state test-mass charging rate and to the single-sided power spectrum of the charge rate noise is marginal with respect to that due to galactic cosmic-rays.

  20. Micrometeorite Science with LISA Pathfinder

    Science.gov (United States)

    Pagane, Nicole; Thorpe, James Ira; Littenberg, Tyson; Littenberg, Tyson; Baker, John; Slutsky, Jacob; Hourihane, Sophie; LISA Pathfinder Team

    2018-01-01

    The primary objective of LISA Pathfinder (LPF) was to demonstrate drag-free control of test masses—along with the technology necessary to maintain the inertial motion—that LISA (Laser Interferometer Space Antenna) would later utilize as a space-based gravitational wave observatory. Due to the precise interferometry used during the mission, LPF could be employed as an accelerometer and used to detect micrometeorite impacts while in orbit about the Sun-Earth Lagrange Point L1. To infer micrometeorite impacts, the flight data was processed for event reconstruction to determine external acceleration of LPF; impact parameters were then estimated through a Markov-Chain Monte-Carlo (MCMC) tool via Bayesian analysis by fitting delta functions in the acceleration domain. As impact candidates were collected, a catalog of event data was curated with the reconstructed estimated parameters, among which were impact sky localizations that were later rotated into more intuitive reference frames. To infer the results of this dust modeling technique, current micrometeorite models were compared to the impact data. In the final reference frame common to the available micrometeorite models, the reconstructed impacts appear to cluster at (±90°, 0°)—where impacts prograde in this longitude-latitude frame were at (-90°, 0°), retrograde were (90°, 0°), and the sun was centered at the origin. The two available models used for comparison were of the Jupiter-family comets (JFC) and Halley-type comets (HTC), which clustered primarily around (±90°, 0°) and (0°, ±20°) respectively. This suggests that the JFC population seems to account for the majority of the impacts detected by LPF. The models’ expected rates given localization and velocity are currently being compared to the reconstructed data to further characterize the micrometeorite populations at L1. We will present our current analysis of this data set and discuss possibilities of extending such an analysis for LISA.

  1. UV-LED-based charge control for LISA

    Science.gov (United States)

    Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Ciani, Giacomo; Mueller, Guido; Conklin, John

    2014-03-01

    The test masses inside the LISA gravitational reference sensors (GRS) must maintain almost pure geodesic motion for gravitational waves to be successfully detected. The residual accelerations have to stay below 3fm/s2/rtHz at all frequencies between 0.1 and 3 mHz. One of the well known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electro-magnetic fields. The LISA pathfinder (LPF) will use Hg-discharge lamps emitting mostly around 253 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. UV-LEDs have a lower mass, a better power efficiency, and are smaller than their Hg counterparts. Furthermore, the latest generation produces light at 240 nm, with energy well above the work function of pure gold. I will describe a preliminary design for effective charge control through photoelectric effect by using these LEDs. The effectiveness of this method is verified by taking Quantum Efficiency (QE) measurements which relate the number of electrons emitted to the number of photons incident on the Au test mass surface. This presentation addresses our initial results and future plans which includes implementation and testing in the UF torsion pendulum and space-qualification in a small satellite mission which will launch in the summer of 2014, through a collaboration with Stanford, KACST, and NASA Ames Research Center.

  2. The Mock LISA Data Challenges: from challenge 3 to challenge 4

    International Nuclear Information System (INIS)

    Babak, Stanislav; Petiteau, Antoine; Robinson, Emma L; Baker, John G; McWilliams, Sean T; Arnaud, Keith A; Benacquista, Matthew J; Cornish, Neil J; Adams, Matt; Larson, Shane L; Mandel, Ilya; Porter, Edward K; Vallisneri, Michele; Cutler, Curt; Vecchio, Alberto; Blaut, Arkadiusz; Bridges, Michael; Feroz, Farhan; Cohen, Michael; Gair, Jonathan R.

    2010-01-01

    The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in April 2008, which demonstrated the positive recovery of signals from chirping galactic binaries, from spinning supermassive-black-hole binaries (with optimal SNRs between ∼10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with Ω gw (f) ∼ 10 -11 , slightly below the LISA instrument noise.

  3. The Mock LISA Data Challenges: from challenge 3 to challenge 4

    Energy Technology Data Exchange (ETDEWEB)

    Babak, Stanislav; Petiteau, Antoine; Robinson, Emma L [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Am Muehlenberg 1, D-14476 Golm bei Potsdam (Germany); Baker, John G; McWilliams, Sean T; Arnaud, Keith A [Gravitational Astrophysics Laboratory, NASA Goddard Space Flight Center, 8800 Greenbelt Rd, Greenbelt, MD 20771 (United States); Benacquista, Matthew J [Center for Gravitational Wave Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States); Cornish, Neil J; Adams, Matt [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Larson, Shane L [Department of Physics, Utah State University, Logan, UT 84322 (United States); Mandel, Ilya [Department of Physics and Astronomy, Northwestern University, Evanston, IL (United States); Porter, Edward K [APC, UMR 7164, University Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, 75025 Paris Cedex 13 (France); Vallisneri, Michele; Cutler, Curt [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Vecchio, Alberto [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B152TT (United Kingdom); Blaut, Arkadiusz [Institute of Theoretical Physics, University of Wroclaw, Wroclaw (Poland); Bridges, Michael; Feroz, Farhan [Astrophysics Group, Cavendish Laboratory, University of Cambridge, Cambridge CB30HE (United Kingdom); Cohen, Michael [Theoretical Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Gair, Jonathan R., E-mail: Michele.Vallisneri@jpl.nasa.go [Institute of Astronomy, University of Cambridge, Cambridge CB30HA (United Kingdom)

    2010-04-21

    The Mock LISA Data Challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of one or more datasets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants analyze the datasets and report best-fit solutions for the source parameters. Here we present the results of the third challenge, issued in April 2008, which demonstrated the positive recovery of signals from chirping galactic binaries, from spinning supermassive-black-hole binaries (with optimal SNRs between approx10 and 2000), from simultaneous extreme-mass-ratio inspirals (SNRs of 10-50), from cosmic-string-cusp bursts (SNRs of 10-100), and from a relatively loud isotropic background with OMEGA{sub gw}(f) approx 10{sup -11}, slightly below the LISA instrument noise.

  4. Probing the Universe with Gravitational Waves: the Laser Interferometer Space Antenna (LISA)

    NARCIS (Netherlands)

    Prince, T.A.; Binetruy, P.; Centrella, J.; Finn, L.; Hogan, C.; Nelemans, G.A.; Phinney, S.

    2007-01-01

    - For the LISA International Science Team: LISA is a joint NASA/ESA space mission designed to measure gravitational waves in the band from 0.1 mHz to 0.1 Hz, a band that is richly populated by strong sources of gravitational waves. Signals will come from a wider range of sources: massive black holes

  5. Interpolation of the magnetic field at the test masses in eLISA

    International Nuclear Information System (INIS)

    Mateos, I; Díaz-Aguiló, M; Ramos-Castro, J; García-Berro, E; Lobo, A

    2015-01-01

    A feasible design for a magnetic diagnostics subsystem for eLISA will be based on that of its precursor mission, LISA Pathfinder. Previous experience indicates that magnetic field estimation at the positions of the test masses has certain complications. This is due to two reasons. The first is that magnetometers usually back-act due to their measurement principles (i.e., they also create their own magnetic fields), while the second is that the sensors selected for LISA Pathfinder have a large size, which conflicts with space resolution and with the possibility of having a sufficient number of them to properly map the magnetic field around the test masses. However, high-sensitivity and small-sized sensors that significantly mitigate the two aforementioned limitations exist, and have been proposed to overcome these problems. Thus, these sensors will be likely selected for the magnetic diagnostics subsystem of eLISA. Here we perform a quantitative analysis of the new magnetic subsystem, as it is currently conceived, and assess the feasibility of selecting these sensors in the final configuration of the magnetic diagnostic subsystem. (paper)

  6. Modulation of LISA free-fall orbits due to the Earth-Moon system

    Energy Technology Data Exchange (ETDEWEB)

    Cerdonio, Massimo; Marzari, Francesco [Department of Physics, University of Padova and INFN Padova, via Marzolo 8, I-35131 Padova (Italy); De Marchi, Fabrizio [Department of Physics, University of Trento and INFN Trento, I-38100 Povo (Trento) (Italy); De Pietri, Roberto [Department of Physics, University of Parma and INFN Parma I-43100 Parma (Italy); Jetzer, Philippe [Institute of Theoretical Physics, University of Zuerich, Winterhurerstrasse 190, 8057 Zuerich (Switzerland); Mazzolo, Giulio [Max Planck Institut fuer Gravitationsphysik, Callinstrasse 38, 30167 Hannover (Germany); Ortolan, Antonello [INFN Laboratori Nazionali di Legnaro, Viale dell' Universita 35020 Legnaro (Padova) (Italy); Sereno, Mauro, E-mail: fdemarchi@science.unitn.i [Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2010-08-21

    We calculate the effect of the Earth-Moon (EM) system on the free-fall motion of LISA test masses. We show that the periodic gravitational pulling of the EM system induces a resonance with fundamental frequency 1 yr{sup -1} and a series of periodic perturbations with frequencies equal to integer harmonics of the synodic month ({approx_equal} 3.92 x 10{sup -7} Hz). We then evaluate the effects of these perturbations (up to the 6th harmonics) on the relative motions between each test mass couple, finding that they range between 3 mm and 10 pm for the 2nd and 6th harmonic, respectively. If we take the LISA sensitivity curve, as extrapolated down to 10{sup -6} Hz in Bender (2003 Class. Quantum Grav. 20 301-10), we obtain that a few harmonics of the EM system can be detected in the Doppler data collected by the LISA space mission. This suggests that the EM system gravitational near field could provide an additional crosscheck to the calibration of LISA, as extended to such low frequencies.

  7. Modulation of LISA free-fall orbits due to the Earth-Moon system

    International Nuclear Information System (INIS)

    Cerdonio, Massimo; Marzari, Francesco; De Marchi, Fabrizio; De Pietri, Roberto; Jetzer, Philippe; Mazzolo, Giulio; Ortolan, Antonello; Sereno, Mauro

    2010-01-01

    We calculate the effect of the Earth-Moon (EM) system on the free-fall motion of LISA test masses. We show that the periodic gravitational pulling of the EM system induces a resonance with fundamental frequency 1 yr -1 and a series of periodic perturbations with frequencies equal to integer harmonics of the synodic month (≅ 3.92 x 10 -7 Hz). We then evaluate the effects of these perturbations (up to the 6th harmonics) on the relative motions between each test mass couple, finding that they range between 3 mm and 10 pm for the 2nd and 6th harmonic, respectively. If we take the LISA sensitivity curve, as extrapolated down to 10 -6 Hz in Bender (2003 Class. Quantum Grav. 20 301-10), we obtain that a few harmonics of the EM system can be detected in the Doppler data collected by the LISA space mission. This suggests that the EM system gravitational near field could provide an additional crosscheck to the calibration of LISA, as extended to such low frequencies.

  8. Annual modulation of the galactic binary confusion noise background and LISA data analysis

    International Nuclear Information System (INIS)

    Seto, Naoki

    2004-01-01

    We study the anisotropies of the galactic confusion noise background and its effects on LISA data analysis. LISA has two data streams of gravitational wave signals relevant for the low frequency regime. Because of the anisotropies of the background, the matrix for their confusion noises has off-diagonal components and depends strongly on the orientation of the detector plane. We find that the sky-averaged confusion noise level √(S(f)) could change by a factor of 2 in 3 months and would be minimum when the orbital position of LISA is around either the spring or autumn equinox

  9. Sensing and actuation system for the University of Florida Torsion Pendulum for LISA

    Science.gov (United States)

    Chilton, Andrew; Shelley, Ryan; Olatunde, Taiwo; Ciani, Giacomo; Conklin, John; Mueller, Guido

    2014-03-01

    Space-based gravitational wave detectors like LISA are a necessity for understanding the low-frequency portion of the gravitational universe. They use test masses (TMs) which are separated by Gm and are in free fall inside their respective spacecraft. Their relative distance is monitored with laser interferometry at the pm/rtHz level in the LISA band, ranging from 0.1 to 100 mHz. Each TM is enclosed in a housing that provides isolation, capacitive sensing, and electrostatic actuation capabilities. The electronics must both be sensitive at the 1 nm/rtHz level and not induce residual acceleration noise above the requirement for LISA Pathfinder (3*10-15 m/sec2Hz1/2at 3 mHz). Testing and developing this technology is one of the roles of the University of Florida Torsion Pendulum, the only US testbed for LISA-like gravitational reference sensor technology. Our implementation of the sensing system functions by biasing our hollow LISA-like TMs with a 100 kHz sine wave and coupling a pair surrounding electrodes as capacitors to a pair of preamps and a differential amplifier; all other processing is done digitally. Here we report on the design of, implementation of, and preliminary results from the UF Torsion Pendulum.

  10. LISA as a dark energy probe

    International Nuclear Information System (INIS)

    Arun, K G; Mishra, Chandra Kant; Iyer, B R; Sinha, Siddhartha; Van Den Broeck, Chris; Sathyaprakash, B S

    2009-01-01

    Recently, it has been shown that the inclusion of higher signal harmonics in the inspiral signals of binary supermassive black holes (SMBH) leads to dramatic improvements in the parameter estimation with Laser Interferometer Space Antenna (LISA). In particular, the angular resolution becomes good enough to identify the host galaxy or galaxy cluster, in which case the redshift can be determined by electromagnetic means. The gravitational wave signal also provides the luminosity distance with high accuracy, and the relationship between this and the redshift depends sensitively on the cosmological parameters, such as the equation-of-state parameter w = p DE /ρ DE of dark energy. Using binary SMBH events at z < 1 with appropriate masses and orientations, one would be able to constrain w to within a few per cent. We show that, if the measured sky location is folded into the error analysis, the uncertainty on w goes down by an additional factor of 2-3, leaving weak lensing as the only limiting factor in using LISA as a dark energy probe.

  11. Estudo bibliométrico do descritor “Ergonomia” na base LISA

    Directory of Open Access Journals (Sweden)

    Eliana Maria dos Santos Bahia

    2011-03-01

    Full Text Available Objetivo: O estudo analisa a produção científica sobre ergonomia utilizando a base de dados Library and Information Science Abstracts (LISA. A base de dados LISA, iniciada em 1969, mantém sua cobertura temática na área de Biblioteconomia e Ciência da Informação.Método: No estudo utilizou-se o método da bibliometria aplicada para verificar a produção científica indexada.Resultados: Entre os resultados da busca de termos indexados na base de dados LISA, encontraram-se 503 artigos com o termo “Ergonomic”; 352 artigos, com a expressão “Design”; 111 artigos com o descritor “Systems”; 110 artigos com o termo “Work”; e , 98 artigos com o termo “Evaluation”. Dentre os 34 títulos de periódicos, 4 títulos cobrem 79% dos artigos que tratam sobre Ergonomia na base LISA. Os demais 30 títulos de periódicos cobrem 21% dos artigos indexados sob essa temática.Conclusões: O presente estudo bibliométrico oferece possibilita um panorama de como a ergonomia é percebida na área da Biblioteconomia e Ciência da Informação.

  12. Dual-Cylinder Laser Reference Cavities for LISA Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "Summary: The Laser Interferometer Space Antenna (LISA) mission is under consideration by NASA and ESA as a joint mission to study gravitational wave signals from a...

  13. The Mona Lisa of modern science.

    Science.gov (United States)

    Kemp, Martin

    2003-01-23

    No molecule in the history of science has reached the iconic status of the double helix of DNA. Its image has been imprinted on all aspects of society, from science, art, music, cinema, architecture and advertising. This review of the Mona Lisa of science examines the evolution of its form at the hands of both science and art.

  14. The Mock LISA Data Challenges: from Challenge 1B to Challenge 3

    International Nuclear Information System (INIS)

    Babak, Stanislav; Porter, Edward K; Gair, Jonathan; Baker, John G; Arnaud, Keith; Benacquista, Matthew J; Cornish, Neil J; Crowder, Jeff; Vallisneri, Michele; Cutler, Curt; Larson, Shane L; Plagnol, Eric; Vecchio, Alberto; Barack, Leor; Blaut, Arkadiusz; Fairhurst, Stephen; Harry, Ian; Gong Xuefei; Khurana, Deepak; Krolak, Andrzej

    2008-01-01

    The Mock LISA Data Challenges are a programme to demonstrate and encourage the development of LISA data-analysis capabilities, tools and techniques. At the time of this workshop, three rounds of challenges had been completed, and the next was about to start. In this paper we provide a critical analysis of the entries to the latest completed round, Challenge 1B. The entries confirm the consolidation of a range of data-analysis techniques for galactic and massive-black-hole binaries, and they include the first convincing examples of detection and parameter estimation of extreme-mass-ratio inspiral sources. In this paper we also introduce the next round, Challenge 3. Its data sets feature more realistic waveform models (e.g., galactic binaries may now chirp, and massive-black-hole binaries may precess due to spin interactions), as well as new source classes (bursts from cosmic strings, isotropic stochastic backgrounds) and more complicated nonsymmetric instrument noise

  15. Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves

    CERN Document Server

    Bartolo, Nicola; Domcke, Valerie; Figueroa, Daniel G.; Garcia-Bellido, Juan; Guzzetti, Maria Chiara; Liguori, Michele; Matarrese, Sabino; Peloso, Marco; Petiteau, Antoine; Ricciardone, Angelo; Sakellariadou, Mairi; Sorbo, Lorenzo; Tasinato, Gianmassimo

    2016-01-01

    We investigate the potential for the LISA space-based interferometer to detect the stochastic gravitational wave background produced from different mechanisms during inflation. Focusing on well-motivated scenarios, we study the resulting contributions from particle production during inflation, inflationary spectator fields with varying speed of sound, effective field theories of inflation with specific patterns of symmetry breaking and models leading to the formation of primordial black holes. The projected sensitivities of LISA are used in a model-independent way for various detector designs and configurations. We demonstrate that LISA is able to probe these well-motivated inflationary scenarios beyond the irreducible vacuum tensor modes expected from any inflationary background.

  16. Science with the space-based interferometer LISA. IV: probing inflation with gravitational waves

    International Nuclear Information System (INIS)

    Bartolo, Nicola; Guzzetti, Maria Chiara; Liguori, Michele; Matarrese, Sabino

    2016-01-01

    We investigate the potential for the LISA space-based interferometer to detect the stochastic gravitational wave background produced from different mechanisms during inflation. Focusing on well-motivated scenarios, we study the resulting contributions from particle production during inflation, inflationary spectator fields with varying speed of sound, effective field theories of inflation with specific patterns of symmetry breaking and models leading to the formation of primordial black holes. The projected sensitivities of LISA are used in a model-independent way for various detector designs and configurations. We demonstrate that LISA is able to probe these well-motivated inflationary scenarios beyond the irreducible vacuum tensor modes expected from any inflationary background.

  17. Alternative opto-mechanical architectures for the LISA instrument

    Energy Technology Data Exchange (ETDEWEB)

    Weise, Dennis R; Marenaci, Pierangelo; Weimer, Peter; Schulte, Hans Reiner; Gath, Peter; Johann, Ulrich, E-mail: dennis.weise@astrium.eads.ne [EADS Astrium GmbH, Claude-Dornier-Str., 88039 Friedrichshafen (Germany)

    2009-03-01

    As part of the on-going LISA Mission Formulation study under ESA contract, EADS Astrium has recently suggested and investigated a variety of novel LISA payload architectures utilizing so-called 'In-Field Pointing' for accommodation of seasonal constellation dynamics. Here, the annual variation in the angle between the interferometer arms of roughly +-1 deg. is compensated by steering the lines of sight of the individual telescopes with a small actuated mirror located in an intermediate pupil plane inside the telescopes. This introduces a certain flexibility for the overall payload configuration and allows for very compact designs. In particular, it enables a 'single active proof mass' mode with a true cold redundancy between a nominal and a backup GRS system on board each spacecraft, and thus enhances mission robustness.

  18. LISA Sources in Milky Way Globular Clusters.

    Science.gov (United States)

    Kremer, Kyle; Chatterjee, Sourav; Breivik, Katelyn; Rodriguez, Carl L; Larson, Shane L; Rasio, Frederic A

    2018-05-11

    We explore the formation of double-compact-object binaries in Milky Way (MW) globular clusters (GCs) that may be detectable by the Laser Interferometer Space Antenna (LISA). We use a set of 137 fully evolved GC models that, overall, effectively match the properties of the observed GCs in the MW. We estimate that, in total, the MW GCs contain ∼21 sources that will be detectable by LISA. These detectable sources contain all combinations of black hole (BH), neutron star, and white dwarf components. We predict ∼7 of these sources will be BH-BH binaries. Furthermore, we show that some of these BH-BH binaries can have signal-to-noise ratios large enough to be detectable at the distance of the Andromeda galaxy or even the Virgo cluster.

  19. Reducing tilt-to-length coupling for the LISA test mass interferometer

    Science.gov (United States)

    Tröbs, M.; Schuster, S.; Lieser, M.; Zwetz, M.; Chwalla, M.; Danzmann, K.; Fernández Barránco, G.; Fitzsimons, E. D.; Gerberding, O.; Heinzel, G.; Killow, C. J.; Perreur-Lloyd, M.; Robertson, D. I.; Schwarze, T. S.; Wanner, G.; Ward, H.

    2018-05-01

    Objects sensed by laser interferometers are usually not stable in position or orientation. This angular instability can lead to a coupling of angular tilt to apparent longitudinal displacement—tilt-to-length coupling (TTL). In LISA this is a potential noise source for both the test mass interferometer and the long-arm interferometer. We have experimentally investigated TTL coupling in a setup representative for the LISA test mass interferometer and used this system to characterise two different imaging systems (a two-lens design and a four-lens design) both designed to minimise TTL coupling. We show that both imaging systems meet the LISA requirement of  ±25 μm rad‑1 for interfering beams with relative angles of up to  ±300 μrad. Furthermore, we found a dependency of the TTL coupling on beam properties such as the waist size and location, which we characterised both theoretically and experimentally.

  20. Relativistic analysis of the LISA long range optical links

    International Nuclear Information System (INIS)

    Chauvineau, Bertrand; Regimbau, Tania; Vinet, Jean-Yves; Pireaux, Sophie

    2005-01-01

    The joint ESA/NASA LISA mission consists of three spacecraft on heliocentric orbits, flying in a triangular formation of 5 Mkm each side, linked by infrared optical beams. The aim of the mission is to detect gravitational waves in a low frequency band. For properly processing the scientific data, the propagation delays between spacecraft must be accurately known. We thus analyze the propagation of light between spacecraft in order to systematically derive the relativistic effects due to the static curvature of the Schwarzschild space-time in which the spacecraft are orbiting with time-varying light distances. In particular, our analysis allows us to evaluate rigorously the Sagnac effect, and the gravitational (Einstein) redshift

  1. GCR flux 9-day variations with LISA Pathfinder

    International Nuclear Information System (INIS)

    Grimani, C; Benella, S; Fabi, M; Finetti, N; Telloni, D

    2017-01-01

    Galactic cosmic-ray (GCR) energy spectra in the heliosphere vary on the basis of the level of solar activity, the status of solar polarity and interplanetary transient magnetic structures of solar origin. A high counting rate particle detector (PD) aboard LISA Pathfinder (LPF) allows for the measurement of galactic cosmic-ray and solar energetic particle (SEP) integral fluxes at energies > 70 MeV n −1 up to 6500 counts s −1 . Data are gathered with a sampling time of 15 s. A study of GCR flux depressions associated with the third harmonic of the Sun rotation period (∼ 9 days) is presented here. (paper)

  2. eLISA eccentricity measurements as tracers of binary black hole formation

    OpenAIRE

    Nishizawa, Atsushi; Berti, Emanuele; Klein, Antoine; Sesana, Alberto

    2016-01-01

    Up to hundreds of black hole binaries individually resolvable by eLISA will coalesce in the Advanced LIGO/Virgo band within ten years, allowing for multi-band gravitational wave observations. Binaries formed via dynamical interactions in dense star clusters are expected to have eccentricities $e_0\\sim 10^{-3}$-$10^{-1}$ at the frequencies $f_0=10^{-2}$ Hz where eLISA is most sensitive, while binaries formed in the field should have negligible eccentricity in both frequency bands. We estimate ...

  3. Nested sampling as a tool for LISA data analysis

    International Nuclear Information System (INIS)

    Gair, Jonathan R; Feroz, Farhan; Graff, Philip; Hobson, Michael P; Babak, Stanislav; Petiteau, Antoine; Porter, Edward K

    2010-01-01

    Nested sampling is a technique for efficiently computing the probability of a data set under a particular hypothesis, also called the Bayesian Evidence or Marginal Likelihood, and for evaluating the posterior. MULTINEST is a multi-modal nested sampling algorithm which has been designed to efficiently explore and characterize posterior probability surfaces containing multiple secondary solutions. We have applied the MULTINEST algorithm to a number of problems in gravitational wave data analysis. In this article, we describe the algorithm and present results for several applications of the algorithm to analysis of mock LISA data. We summarise recently published results for a test case in which we searched for two non-spinning black hole binary merger signals in simulated LISA data. We also describe results obtained with MULTINEST in the most recent round of the Mock LISA Data Challenge (MLDC), in which the algorithm was used to search for and characterise both spinning supermassive black hole binary inspirals and bursts from cosmic string cusps. In all these applications, the algorithm found the correct number of signals and efficiently recovered the posterior probability distribution. Moreover, in most cases the waveform corresponding to the best a-posteriori parameters had an overlap in excess of 99% with the true signal.

  4. Nested sampling as a tool for LISA data analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gair, Jonathan R [Institute of Astronomy, Madingley Road, CB3 0HA, Cambridge (United Kingdom); Feroz, Farhan; Graff, Philip; Hobson, Michael P [Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Babak, Stanislav; Petiteau, Antoine [Max-Planck-Institut fuer Gravitationsphysik, Am Muehlenberg 1, 14476, Potsdam (Germany); Porter, Edward K, E-mail: jgair@ast.cam.ac.u [APC, UMR 7164, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)

    2010-05-01

    Nested sampling is a technique for efficiently computing the probability of a data set under a particular hypothesis, also called the Bayesian Evidence or Marginal Likelihood, and for evaluating the posterior. MULTINEST is a multi-modal nested sampling algorithm which has been designed to efficiently explore and characterize posterior probability surfaces containing multiple secondary solutions. We have applied the MULTINEST algorithm to a number of problems in gravitational wave data analysis. In this article, we describe the algorithm and present results for several applications of the algorithm to analysis of mock LISA data. We summarise recently published results for a test case in which we searched for two non-spinning black hole binary merger signals in simulated LISA data. We also describe results obtained with MULTINEST in the most recent round of the Mock LISA Data Challenge (MLDC), in which the algorithm was used to search for and characterise both spinning supermassive black hole binary inspirals and bursts from cosmic string cusps. In all these applications, the algorithm found the correct number of signals and efficiently recovered the posterior probability distribution. Moreover, in most cases the waveform corresponding to the best a-posteriori parameters had an overlap in excess of 99% with the true signal.

  5. Report on the second Mock LISA data challenge

    International Nuclear Information System (INIS)

    Babak, Stanislav; Porter, Edward K; Baker, John G; Benacquista, Matthew J; Cornish, Neil J; Littenberg, Tyson B; Crowder, Jeff; Cutler, Curt; Vallisneri, Michele; Larson, Shane L; Vecchio, Alberto; Auger, Gerard; Barack, Leor; Blaut, Arkadiusz; Bloomer, Ed; Clark, James; Brown, Duncan A; Fairhurst, Stephen; Christensen, Nelson; Gair, Jonathan R

    2008-01-01

    The Mock LISA data challenges are a program to demonstrate LISA data-analysis capabilities and to encourage their development. Each round of challenges consists of several data sets containing simulated instrument noise and gravitational waves from sources of undisclosed parameters. Participants are asked to analyze the data sets and report the maximum information about the source parameters. The challenges are being released in rounds of increasing complexity and realism: here we present the results of Challenge 2, issued in Jan 2007, which successfully demonstrated the recovery of signals from nonspinning supermassive-black-hole binaries with optimal SNRs between ∼10 and 2000, from ∼20 000 overlapping galactic white-dwarf binaries (among a realistically distributed population of 26 million), and from the extreme-mass-ratio inspirals of compact objects into central galactic black holes with optimal SNRs ∼100

  6. Massive black-hole binary inspirals: results from the LISA parameter estimation taskforce

    International Nuclear Information System (INIS)

    Arun, K G; Babak, Stas; Porter, Edward K; Sintes, Alicia M; Berti, Emanuele; Cutler, Curt; Cornish, Neil; Gair, Jonathan; Hughes, Scott A; Lang, Ryan N; Iyer, Bala R; Sinha, Siddhartha; Mandel, Ilya; Sathyaprakash, Bangalore S; Van Den Broeck, Chris; Trias, Miquel; Volonteri, Marta

    2009-01-01

    The LISA Parameter Estimation Taskforce was formed in September 2007 to provide the LISA Project with vetted codes, source distribution models and results related to parameter estimation. The Taskforce's goal is to be able to quickly calculate the impact of any mission design changes on LISA's science capabilities, based on reasonable estimates of the distribution of astrophysical sources in the universe. This paper describes our Taskforce's work on massive black-hole binaries (MBHBs). Given present uncertainties in the formation history of MBHBs, we adopt four different population models, based on (i) whether the initial black-hole seeds are small or large and (ii) whether accretion is efficient or inefficient at spinning up the holes. We compare four largely independent codes for calculating LISA's parameter-estimation capabilities. All codes are based on the Fisher-matrix approximation, but in the past they used somewhat different signal models, source parametrizations and noise curves. We show that once these differences are removed, the four codes give results in extremely close agreement with each other. Using a code that includes both spin precession and higher harmonics in the gravitational-wave signal, we carry out Monte Carlo simulations and determine the number of events that can be detected and accurately localized in our four population models.

  7. Description of charging/discharging processes of the LISA sensors

    International Nuclear Information System (INIS)

    Sumner, Tim; Araujo, Henrique; Davidge, David; Howard, Alex; Lee, Chris; Rochester, Geoff; Shaul, Diana; Wass, Peter

    2004-01-01

    The next generation of gravitational experiments in space is likely to use completely isolated proof-masses. For example, LISA uses proof-masses as mirrors in interferometers for gravitational wave astronomy (Bender et al 1998 Pre-phase A report MPG-233 pp 1-191) and STEP uses proof-masses in Earth orbit for an equivalence principle test (Sumner et al 2003 at press). Nongravitational forces will act on these proof-masses if they become charged, through the action of cosmic rays and solar flare particles for example. This paper examines the consequences of proof-mass charging for LISA, and presents results from using GEANT4 to assess the charging processes. Finally, there is a brief discussion of a means of controlling the charge down to an acceptable level

  8. Constraining stellar binary black hole formation scenarios with eLISA eccentricity measurements

    OpenAIRE

    Nishizawa, Atsushi; Sesana, Alberto; Berti, Emanuele; Klein, Antoine

    2016-01-01

    A space-based interferometer such as eLISA could observe few to few thousands progenitors of black hole binaries (BHBs) similar to those recently detected by Advanced LIGO. Gravitational radiation circularizes the orbit during inspiral, but some BHBs retain a measurable eccentricity at the low frequencies where eLISA is most sensitive. The eccentricity of a BHB carries precious information about its formation channel: BHBs formed in the field, in globular clusters, or close to a massive black...

  9. Rapid prototyping and evaluation of programmable SIMD SDR processors in LISA

    Science.gov (United States)

    Chen, Ting; Liu, Hengzhu; Zhang, Botao; Liu, Dongpei

    2013-03-01

    With the development of international wireless communication standards, there is an increase in computational requirement for baseband signal processors. Time-to-market pressure makes it impossible to completely redesign new processors for the evolving standards. Due to its high flexibility and low power, software defined radio (SDR) digital signal processors have been proposed as promising technology to replace traditional ASIC and FPGA fashions. In addition, there are large numbers of parallel data processed in computation-intensive functions, which fosters the development of single instruction multiple data (SIMD) architecture in SDR platform. So a new way must be found to prototype the SDR processors efficiently. In this paper we present a bit-and-cycle accurate model of programmable SIMD SDR processors in a machine description language LISA. LISA is a language for instruction set architecture which can gain rapid model at architectural level. In order to evaluate the availability of our proposed processor, three common baseband functions, FFT, FIR digital filter and matrix multiplication have been mapped on the SDR platform. Analytical results showed that the SDR processor achieved the maximum of 47.1% performance boost relative to the opponent processor.

  10. Optical testbed for the LISA phasemeter

    Science.gov (United States)

    Schwarze, T. S.; Fernández Barranco, G.; Penkert, D.; Gerberding, O.; Heinzel, G.; Danzmann, K.

    2016-05-01

    The planned spaceborne gravitational wave detector LISA will allow the detection of gravitational waves at frequencies between 0.1 mHz and 1 Hz. A breadboard model for the metrology system aka the phasemeter was developed in the scope of an ESA technology development project by a collaboration between the Albert Einstein Institute, the Technical University of Denmark and the Danish industry partner Axcon Aps. It in particular provides the electronic readout of the main interferometer phases besides auxiliary functions. These include clock noise transfer, ADC pilot tone correction, inter-satellite ranging and data transfer. Besides in LISA, the phasemeter can also be applied in future satellite geodesy missions. Here we show the planning and advances in the implementation of an optical testbed for the full metrology chain. It is based on an ultra-stable hexagonal optical bench. This bench allows the generation of three unequal heterodyne beatnotes with a zero phase combination, thus providing the possibility to probe the phase readout for non-linearities in an optical three signal test. Additionally, the utilization of three independent phasemeters will allow the testing of the auxiliary functions. Once working, components can individually be replaced with flight-qualified hardware in this setup.

  11. Optical testbed for the LISA phasemeter

    International Nuclear Information System (INIS)

    Schwarze, T S; Fernández Barranco, G; Penkert, D; Gerberding, O; Heinzel, G; Danzmann, K

    2016-01-01

    The planned spaceborne gravitational wave detector LISA will allow the detection of gravitational waves at frequencies between 0.1 mHz and 1 Hz. A breadboard model for the metrology system aka the phasemeter was developed in the scope of an ESA technology development project by a collaboration between the Albert Einstein Institute, the Technical University of Denmark and the Danish industry partner Axcon Aps. It in particular provides the electronic readout of the main interferometer phases besides auxiliary functions. These include clock noise transfer, ADC pilot tone correction, inter-satellite ranging and data transfer. Besides in LISA, the phasemeter can also be applied in future satellite geodesy missions. Here we show the planning and advances in the implementation of an optical testbed for the full metrology chain. It is based on an ultra-stable hexagonal optical bench. This bench allows the generation of three unequal heterodyne beatnotes with a zero phase combination, thus providing the possibility to probe the phase readout for non-linearities in an optical three signal test. Additionally, the utilization of three independent phasemeters will allow the testing of the auxiliary functions. Once working, components can individually be replaced with flight-qualified hardware in this setup. (paper)

  12. Recent progress at NASA in LISA formulation and technology development

    International Nuclear Information System (INIS)

    Stebbins, R T

    2008-01-01

    Over the last year, the NASA half of the joint LISA project has focused its efforts on responding to a major review, and advancing the formulation and technology development of the mission. The NAS/NRC Beyond Einstein program assessment review will be described, including the outcome. The basis of the LISA science requirements has changed from detection determined by integrated signal-to-noise ratio to observation determined by uncertainty in the estimation of astrophysical source parameters. The NASA team has further defined the spacecraft bus design, participated in many design trade studies and advanced the requirements flow down and the associated current best estimates of performance. Recent progress in technology development is also summarized

  13. The first mock data challenge for LISA Pathfinder

    Energy Technology Data Exchange (ETDEWEB)

    Monsky, A; Hewitson, M; Wanner, G; Nofrarias, M; Diepholz, I; Danzmann, K [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik und Universitaet Hannover, 30167 Hannover (Germany); Ferraioli, L; Hueller, M; Cavalleri, A; Ciani, G; Dolesi, R [Dipartimento di Fisica, Universita di Trento and INFN, Gruppo Collegato di Trento, 38050 Povo, Trento (Italy); Grynagier, A [Institut fuer Flugmechanik und Flugregelung, 70569 Stuttgart (Germany); Armano, M [European Space Agency, ESAC, Villanueva de la Canada, 28692 Madrid (Spain); Benedetti, M [Dipartimento di Ingegneria dei Materiali e Tecnologie Industriali, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Bogenstahl, J [Department of Physics and Astronomy, University of Glasgow, Glasgow (United Kingdom); Bortoluzzi, D; Bosetti, P; Cristofolini, I [Dipartimento di Ingegneria Meccanica e Strutturale, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Brandt, N [Astrium GmbH, 88039 Friedrichshafen (Germany); Cruise, M, E-mail: anneke.monsky@aei.mpg.d [Department of Physics and Astronomy, University of Birmingham, Birmingham (United Kingdom)

    2009-05-07

    The data analysis of the LISA Technology Package (LTP) will comprise a series of discrete experiments, each focusing on a particular noise measurement or characterization of the instrument in various operating modes. Each of these experiments must be analysed and planned in advance of the mission because the results of a given experiment will have an impact on those that follow. As such, a series of mock data challenges (MDCs) will be developed and carried out with the aim of preparing the analysis tools and optimizing the various planned analyses. The first of these MDCs (MDC1) is a simplified treatment of the dynamics along the axis joining the two test masses onboard LISA Pathfinder. The validation of the dynamical model by predicting the spectra of the interferometer output data is shown, a prediction for the data analysis is calculated and, finally, several simulated interferometer data sets are analysed and calibrated to equivalent out-of-loop test mass acceleration.

  14. Advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) Small Spacecraft System

    Science.gov (United States)

    Lockett, Tiffany Russell; Martinez, Armando; Boyd, Darren; SanSouice, Michael; Farmer, Brandon; Schneider, Todd; Laue, Greg; Fabisinski, Leo; Johnson, Les; Carr, John A.

    2015-01-01

    This paper describes recent advancements of the Lightweight Integrated Solar Array and Transceiver (LISA-T) currently being developed at NASA's Marshall Space Flight Center. The LISA-T array comprises a launch stowed, orbit deployed structure on which thin-film photovoltaic (PV) and antenna devices are embedded. The system provides significant electrical power generation at low weights, high stowage efficiency, and without the need for solar tracking. Leveraging high-volume terrestrial-market PVs also gives the potential for lower array costs. LISA-T is addressing the power starvation epidemic currently seen by many small-scale satellites while also enabling the application of deployable antenna arrays. Herein, an overview of the system and its applications are presented alongside sub-system development progress and environmental testing plans.

  15. LISA detection of massive black hole binaries: imprint of seed populations and extreme recoils

    International Nuclear Information System (INIS)

    Sesana, A; Volonteri, M; Haardt, F

    2009-01-01

    All the physical processes involved in the formation, merging and accretion history of massive black holes along the hierarchical build-up of cosmic structures are likely to leave an imprint on the gravitational waves detectable by future space-borne missions, such as LISA. We report here the results of recent studies, carried out by means of dedicated simulations of black hole build-up, aiming at understanding the impact on LISA observations of two ingredients that are crucial in every massive black hole formation scenario, namely: (i) the nature and abundance of the first black hole seeds and (ii) the large gravitational recoils following the merger of highly spinning black holes. We predict LISA detection rates spanning two orders of magnitude, in the range 3-300 events per year, depending on the detail of the assumed massive black hole seed model. On the other hand, large recoil velocities do not dramatically compromise the efficiency of LISA observations. The number of detections may drop substantially (by ∼60%), in scenarios characterized by abundant light seeds, but if seeds are already massive and/or relatively rare, the detection rate is basically unaffected.

  16. In-orbit performance of the LISA Pathfinder drag-free and attitude control system

    Science.gov (United States)

    Schleicher, A.; Ziegler, T.; Schubert, R.; Brandt, N.; Bergner, P.; Johann, U.; Fichter, W.; Grzymisch, J.

    2018-04-01

    LISA Pathfinder is a technology demonstrator mission that was funded by the European Space Agency and that was launched on December 3, 2015. LISA Pathfinder has been conducting experiments to demonstrate key technologies for the gravitational wave observatory LISA in its operational orbit at the L1 Lagrange point of the Earth-Sun system until final switch off on July 18, 2017. These key technologies include the inertial sensors, the optical metrology system, a set of µ-propulsion cold gas thrusters and in particular the high performance drag-free and attitude control system (DFACS) that controls the spacecraft in 15 degrees of freedom during its science phase. The main goal of the DFACS is to shield the two test masses inside the inertial sensors from all external disturbances to achieve a residual differential acceleration between the two test masses of less than 3 × 10-14 m/s2/√Hz over the frequency bandwidth of 1-30 mHz. This paper focuses on two important aspects of the DFACS that has been in use on LISA Pathfinder: the DFACS Accelerometer mode and the main DFACS Science mode. The Accelerometer mode is used to capture the test masses after release into free flight from the mechanical grabbing mechanism. The main DFACS Science Mode is used for the actual drag-free science operation. The DFACS control system has very strong interfaces with the LISA Technology Package payload which is a key aspect to master the design, development, and analysis of the DFACS. Linear as well as non-linear control methods are applied. The paper provides pre-flight predictions for the performance of both control modes and compares these predictions to the performance that is currently achieved in-orbit. Some results are also discussed for the mode transitions up to science mode, but the focus of the paper is on the Accelerometer mode performance and on the performance of the Science mode in steady state. Based on the achieved results, some lessons learnt are formulated to extend

  17. LISA Pathfinder: OPD loop characterisation

    Science.gov (United States)

    Born, Michael; LPF Collaboration

    2017-05-01

    The optical metrology system (OMS) of the LISA Pathfinder mission is measuring the distance between two free-floating test masses with unprecedented precision. One of the four OMS heterodyne interferometers reads out the phase difference between the reference and the measurement laser beam. This phase from the reference interferometer is common to all other longitudinal interferometer read outs and therefore subtracted. In addition, the phase is fed back via the digital optical pathlength difference (OPD) control loop to keep it close to zero. Here, we analyse the loop parameters and compare them to on-ground measurement results.

  18. Science with the space-based interferometer eLISA. II. Gravitational waves from cosmological phase transitions

    International Nuclear Information System (INIS)

    Caprini, Chiara; Hindmarsh, Mark; Helsinki Univ.; Huber, Stephan

    2016-04-01

    We investigate the potential for the eLISA space-based interferometer to detect the stochastic gravitational wave background produced by strong first-order cosmological phase transitions. We discuss the resulting contributions from bubble collisions, magnetohydrodynamic turbulence, and sound waves to the stochastic background, and estimate the total corresponding signal predicted in gravitational waves. The projected sensitivity of eLISA to cosmological phase transitions is computed in a model-independent way for various detector designs and configurations. By applying these results to several specific models, we demonstrate that eLISA is able to probe many well-motivated scenarios beyond the Standard Model of particle physics predicting strong first-order cosmological phase transitions in the early Universe.

  19. Demonstration of AC and DC charge control for the LISA test masses

    Science.gov (United States)

    Olatunde, Taiwo Janet

    2018-01-01

    Taiwo Olatunde, Stephen Apple, Andrew Chilton, Samantha Parry, Peter Wass, Guido Mueller, John W. Conklin The residual test mass acceleration in LISA must be below 3 fm/s2/√Hz at all frequencies between 0.1 and 3 mHz. Test mass charge coupled with stray electrical potentials and external electromagnetic fields is a well-known source of acceleration noise. LISA Pathfinder uses Hg lamps emitting mostly around 254 nm to discharge the test masses via photoemission, but a future LISA mission launched around 2030 will likely replace the lamps with newer UV LEDs with lower mass, better power efficiency, smaller size and higher bandwidth. This presentation will discuss charge control demonstrated on the torsion pendulum in AC and DC modes at the University of Florida using latest generation UV LEDs producing light at 240 nm with energy above the work function of pure Au. Initial results of Au quantum efficiency measurements (number of emitted electrons per incident photons) which is critical for bi-polar charge control will also be presented.

  20. Construction of an optical test-bed for eLISA

    International Nuclear Information System (INIS)

    Lieser, Maike; Isleif, K-S; Schuster, S; Tröbs, M; Veith, S; Heinzel, G; Danzmann, K; Fitzsimons, E; Killow, C; Perreur-Lloyd, M; Robertson, D; Ward, H

    2016-01-01

    In the planned eLISA mission a key part of the system is the optical bench that holds the interferometers for reading out the inter-spacecraft distance and the test mass position. We report on ongoing technology development for the eLISA optical system like the back-link between the optical benches and the science interferometer where the local beam is interfered with the received beam from the distant spacecraft. The focus will be on a setup to investigate the tilt-to-pathlength coupling in the science interferometer. To test the science interferometer in the lab a second bench providing a laser beam and a reference interferometer is needed. We present a setup with two ultra-stable low expansion glass benches and bonded optics. To suppress the tilt-to-pathlength coupling to the required level (few μm/rad) imaging optics are placed in front of the interferometer photo diodes. (paper)

  1. 77 FR 56647 - Lisa Jean Sharp: Debarment Order

    Science.gov (United States)

    2012-09-13

    ... Act (the FD&C Act) permanently debarring Lisa Jean Sharp from providing services in any capacity to a...&C Act. Ms. Sharp was given notice of the proposed permanent debarment and an opportunity to request... drug product under the FD&C Act. The factual basis for this conviction is as follows: Ms. Sharp was the...

  2. Towards an improved magnetic diagnostic system for LISA

    International Nuclear Information System (INIS)

    Mateos, I; Lobo, A; Sanjuan, J; Ramos-Castro, J; Nofrarias, M

    2009-01-01

    The current design, and material implementation of the magnetic field sensing in the LISA Technology Package (LTP) on board LISA Pathfinder (LPF), is based on a set of 4 high-precision 3-axis fluxgate magnetometers. In order to avoid magnetic disturbances on the LTP proof masses (TM 's), originated by the sensors themselves, these are placed somewhat far from the TM's, which results in partial field information losses. We are currently investigating alternative magnetic sensing techniques, based on AMR (Anisotropic Magnetoresistive) devices. These are much smaller in size than fluxgates, therefore a more numerous array can be thought of for flight. In addition, there is a chance that they may be attached closer to the TM's, thereby enhancing magnetic field sensing spacial resolution. Several issues need to be addressed, such as real sensitivity (including electronics noise) and set/reset trigger procedures. A brief overview about the stability of the magnetic fields and gradients generated in the LTP by means of the coil will also be given. This paper show the latest results of our research.

  3. The end-to-end testbed of the optical metrology system on-board LISA Pathfinder

    Energy Technology Data Exchange (ETDEWEB)

    Steier, F; Cervantes, F Guzman; Marin, A F GarcIa; Heinzel, G; Danzmann, K [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut) and Universitaet Hannover (Germany); Gerardi, D, E-mail: frank.steier@aei.mpg.d [EADS Astrium Satellites GmbH, Friedrichshafen (Germany)

    2009-05-07

    LISA Pathfinder is a technology demonstration mission for the Laser Interferometer Space Antenna (LISA). The main experiment on-board LISA Pathfinder is the so-called LISA Technology Package (LTP) which has the aim to measure the differential acceleration between two free-falling test masses with an accuracy of 3 x 10{sup -14} ms{sup -2} Hz{sup -1/2} between 1 mHz and 30 mHz. This measurement is performed interferometrically by the optical metrology system (OMS) on-board LISA Pathfinder. In this paper, we present the development of an experimental end-to-end testbed of the entire OMS. It includes the interferometer and its sub-units, the interferometer backend which is a phasemeter and the processing of the phasemeter output data. Furthermore, three-axes piezo-actuated mirrors are used instead of the free-falling test masses for the characterization of the dynamic behaviour of the system and some parts of the drag-free and attitude control system (DFACS) which controls the test masses and the satellite. The end-to-end testbed includes all parts of the LTP that can reasonably be tested on earth without free-falling test masses. At its present status it consists mainly of breadboard components. Some of those have already been replaced by engineering models of the LTP experiment. In the next steps, further engineering and flight models will also be inserted in this testbed and tested against well-characterized breadboard components. The presented testbed is an important reference for the unit tests and can also be used for validation of the on-board experiment during the mission.

  4. Stellar binary black holes in the LISA band: a new class of standard sirens

    Science.gov (United States)

    Del Pozzo, Walter; Sesana, Alberto; Klein, Antoine

    2018-04-01

    The recent Advanced LIGO detections of coalescing black hole binaries (BHBs) imply a large population of such systems emitting at milli-Hz frequencies, accessible to the Laser Interferometer Space Antenna (LISA). We show that these systems provide a new class of cosmological standard sirens. Direct LISA luminosity distance - Dl - measurements, combined with the inhomogeneous redshift - z - distribution of possible host galaxies provide an effective way to populate the Dl-z diagram at z arm-length, respectively.

  5. In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors

    International Nuclear Information System (INIS)

    Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

    2015-01-01

    Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations. (paper)

  6. Cosmological Backgrounds of Gravitational Waves and eLISA

    OpenAIRE

    Dufaux, Jean-Francois

    2012-01-01

    We review cosmological backgrounds of gravitational waves with a particular attention to the scientific potential of the eLISA/NGO mission. After an overview of cosmological backgrounds and detectors, we consider different cosmological sources that could lead to an observable signal. We then study the backgrounds produced by first-order phase transitions and networks of cosmic strings, assessing the prospects for their detection.

  7. LTP - LISA technology package: Development challenges of a spaceborne fundamental physics experiment

    International Nuclear Information System (INIS)

    Gerndt, R

    2009-01-01

    The LISA Technology Package (LTP) is the main payload onboard the LISA Pathfinder Spacecraft. The LTP Instrument together with the Drag-Free Attitude Control System (DFACS) and the respective LTP and DFACS operational software forms the LTP Experiment. It is completed by the FEEPs of the LPF spacecraft that are controlled by DFACS in order to control the spacecraft's attitude along with the experiment's needs. This article concentrates on aspects of the Industrial development of the LTP Instrument items and on essential performance issues of LTP. Examples of investigations on specific issue will highlight the kind of special problems to be solved for LTP in close cooperation with the Scientific Community.

  8. LISA: A performance assessment code for geological repositories of radioactive waste

    International Nuclear Information System (INIS)

    Bertozzi, G.; Saltelli, A.

    1985-01-01

    LISA, developed at JRC-Ispra, is a statistical code, which calculates the radiation exposures and risks associated with radionuclide releases from geological repositories of nuclear waste. The assessment methodology is described briefly. It requires that a number of probabilistic components be quantified and introduced in the analysis; the results are thus expressed in terms of risk. The subjective judgment of experts may be necessary to quantify the probabilities of occurrence of rare geological events. Because of large uncertainties in input data, statistical treatment of the Monte Carlo type is utilized for the analysis; thus, the output from LISA is obtained in the form of distributions. A few results of an application to a probabilistic scenario for a repository mined in a clay bed are illustrated

  9. Acoustic waves and the detectability of first-order phase transitions by eLISA

    Science.gov (United States)

    Weir, David J.

    2017-05-01

    In various extensions of the Standard Model it is possible that the electroweak phase transition was first order. This would have been a violent process, involving the formation of bubbles and associated shock waves. Not only would the collision of these bubbles and shock waves be a detectable source of gravitational waves, but persistent acoustic waves could enhance the signal and improve prospects of detection by eLISA. I summarise the results of a recent campaign to model such a phase transition based on large-scale hydrodynamical simulations, and its implications for the eLISA mission.

  10. LTP - LISA technology package: Development challenges of a spaceborne fundamental physics experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gerndt, R, E-mail: ruediger.gerndt@astrium.eads.ne [Astrium Satellites GmbH, Claude-Dornier-Str., 88090 Immenstaad (Germany)

    2009-03-01

    The LISA Technology Package (LTP) is the main payload onboard the LISA Pathfinder Spacecraft. The LTP Instrument together with the Drag-Free Attitude Control System (DFACS) and the respective LTP and DFACS operational software forms the LTP Experiment. It is completed by the FEEPs of the LPF spacecraft that are controlled by DFACS in order to control the spacecraft's attitude along with the experiment's needs. This article concentrates on aspects of the Industrial development of the LTP Instrument items and on essential performance issues of LTP. Examples of investigations on specific issue will highlight the kind of special problems to be solved for LTP in close cooperation with the Scientific Community.

  11. Constraining early and interacting dark energy with gravitational wave standard sirens: the potential of the eLISA mission

    International Nuclear Information System (INIS)

    Caprini, Chiara; Tamanini, Nicola

    2016-01-01

    We perform a forecast analysis of the capability of the eLISA space-based interferometer to constrain models of early and interacting dark energy using gravitational wave standard sirens. We employ simulated catalogues of standard sirens given by merging massive black hole binaries visible by eLISA, with an electromagnetic counterpart detectable by future telescopes. We consider three-arms mission designs with arm length of 1, 2 and 5 million km, 5 years of mission duration and the best-level low frequency noise as recently tested by the LISA Pathfinder. Standard sirens with eLISA give access to an intermediate range of redshift 1 ∼< z ∼< 8, and can therefore provide competitive constraints on models where the onset of the deviation from ΛCDM (i.e. the epoch when early dark energy starts to be non-negligible, or when the interaction with dark matter begins) occurs relatively late, at z ∼< 6. If instead early or interacting dark energy is relevant already in the pre-recombination era, current cosmological probes (especially the cosmic microwave background) are more efficient than eLISA in constraining these models, except possibly in the interacting dark energy model if the energy exchange is proportional to the energy density of dark energy.

  12. Disentangling the magnetic force noise contribution in LISA Pathfinder

    International Nuclear Information System (INIS)

    Armano, M; Audley, H; Born, M; Danzmann, K; Diepholz, I; Auger, G; Binetruy, P; Baird, J; Bortoluzzi, D; Brandt, N; Fitzsimons, E; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Dolesi, R; Ferroni, V; Cruise, M; Dunbar, N; Ferraioli, L

    2015-01-01

    Magnetically-induced forces on the inertial masses on-board LISA Pathfinder are expected to be one of the dominant contributions to the mission noise budget, accounting for up to 40%. The origin of this disturbance is the coupling of the residual magnetization and susceptibility of the test masses with the environmental magnetic field. In order to fully understand this important part of the noise model, a set of coils and magnetometers are integrated as a part of the diagnostics subsystem. During operations a sequence of magnetic excitations will be applied to precisely determine the coupling of the magnetic environment to the test mass displacement using the on-board magnetometers. Since no direct measurement of the magnetic field in the test mass position will be available, an extrapolation of the magnetic measurements to the test mass position will be carried out as a part of the data analysis activities. In this paper we show the first results on the magnetic experiments during an end- to-end LISA Pathfinder simulation, and we describe the methods under development to map the magnetic field on-board. (paper)

  13. Review: Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday (2011 Buchbesprechung: Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday (2011

    Directory of Open Access Journals (Sweden)

    Jigal Beez

    2013-01-01

    Full Text Available Review of the monograph:Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday, Hamburg: Verlag Dr. Kovač, 2011, ISBN 978-3-8300-5806-9, 216 pagesBesprechung der Monographie:Lisa Mackenrodt, Swahili Spirit Possession and Islamic Healing in Contemporary Tanzania: The Jinn Fly on Friday, Hamburg: Verlag Dr. Kovač, 2011, ISBN 978-3-8300-5806-9, 216 Seiten

  14. Editorial. Special issue of Classical and Quantum Gravity on the proceedings of the 4th international LISA symposium

    International Nuclear Information System (INIS)

    Finn, Lee Samuel

    2003-01-01

    The 4th International LISA Symposium was held at the National Science Foundation Physics Frontier Center for Gravitational Wave Physics at The Pennsylvania State University on 19-24 July 2002. This special issue of Classical and Quantum Gravity is the proceedings of this meeting. LISA - the Laser Interferometer Space Antenna - is part of an international effort to open a new window on the universe. Not all things radiate light, but everything gravitates. Observations of the gravitational waves radiated by black holes and compact binary star systems, in our galaxy and beyond, can reveal details about these systems and their environments that are otherwise inaccessible. The international effort, of which LISA is a part, includes ground-based detectors, and the relationship between LISA and its ground-based detector 'cousins' was an important theme for this Symposium. LISA will observe gravitational waves in the 0.1 mHz to 0.1 Hz band, complementing observations made by ground-based detectors in the 10 Hz to several KHz band. Together they will explore nearly six decades of bandwidth in the gravitational-wave sky. LISA in particular will observe the gravitational waves radiated by the coalescence of black holes at the centres of colliding galaxies, and the inspiral of compact neutron stars or stellar-mass black holes onto these black holes, virtually anywhere in the universe. It will take a census of neutron star or close white dwarf binaries in our own galaxy and observe the formation of large black holes from the very first structures to form and collapse in our universe. In doing all these things, it will shed new 'light' on the first structures to form in the universe, explore the evolution of galaxies and the roles that black holes play in their structure, test relativity near the 'edges' of a black hole, and deepen our understanding of stellar and binary system evolution. A successful conference - and this LISA Symposium, like its predecessors, was very

  15. Sub-pm{{\\sqrt{Hz}^{-1}}} non-reciprocal noise in the LISA backlink fiber

    Science.gov (United States)

    Fleddermann, Roland; Diekmann, Christian; Steier, Frank; Tröbs, Michael; Heinzel, Gerhard; Danzmann, Karsten

    2018-04-01

    The future space-based gravitational wave detector laser interferometer space antenna (LISA) requires bidirectional exchange of light between its two optical benches on board of each of its three satellites. The current baseline foresees a polarization-maintaining single-mode fiber for this backlink connection. Phase changes which are common in both directions do not enter the science measurement, but differential (‘non-reciprocal’) phase fluctuations directly do and must thus be guaranteed to be small enough. We have built a setup consisting of a Zerodur baseplate with fused silica components attached to it using hydroxide-catalysis bonding and demonstrated the reciprocity of a polarization-maintaining single-mode fiber at the 1 pm \\sqrt{Hz}-1 level as is required for LISA. We used balanced detection to reduce the influence of parasitic optical beams on the reciprocity measurement and a fiber length stabilization to avoid nonlinear effects in our phase measurement system (phase meter). For LISA, a different phase meter is planned to be used that does not show this nonlinearity. We corrected the influence of beam angle changes and temperature changes on the reciprocity measurement in post-processing.

  16. GRS vs. OMS Calibration in LISA Pathfinder Data Analysis

    Science.gov (United States)

    Meshksar, Neda; Ferraioli, Luigi; Mance, Davor; ten Pierick, Jan; Zweifel, Peter; Giardini, Domenico; ">LISA Pathfinder colaboration, LISA Pathfinder spacecraft the test mass displacement along the main measurement axis is sensed in two different ways: optically and electrostatically. We have monitored the relative calibration between the two measurements during the mission science phase. The trend sensitivity of the relative calibration has been computed for different physical parameters, such as temperature, magnetic field, test mass bias voltage and current.

  17. Automatic system for quantification and visualization of lung aeration on chest computed tomography images: the Lung Image System Analysis - LISA

    International Nuclear Information System (INIS)

    Felix, John Hebert da Silva; Cortez, Paulo Cesar; Holanda, Marcelo Alcantara

    2010-01-01

    High Resolution Computed Tomography (HRCT) is the exam of choice for the diagnostic evaluation of lung parenchyma diseases. There is an increasing interest for computational systems able to automatically analyze the radiological densities of the lungs in CT images. The main objective of this study is to present a system for the automatic quantification and visualization of the lung aeration in HRCT images of different degrees of aeration, called Lung Image System Analysis (LISA). The secondary objective is to compare LISA to the Osiris system and also to specific algorithm lung segmentation (ALS), on the accuracy of the lungs segmentation. The LISA system automatically extracts the following image attributes: lungs perimeter, cross sectional area, volume, the radiological densities histograms, the mean lung density (MLD) in Hounsfield units (HU), the relative area of the lungs with voxels with density values lower than -950 HU (RA950) and the 15th percentile of the least density voxels (PERC15). Furthermore, LISA has a colored mask algorithm that applies pseudo-colors to the lung parenchyma according to the pre-defined radiological density chosen by the system user. The lungs segmentations of 102 images of 8 healthy volunteers and 141 images of 11 patients with Chronic Obstructive Pulmonary Disease (COPD) were compared on the accuracy and concordance among the three methods. The LISA was more effective on lungs segmentation than the other two methods. LISA's color mask tool improves the spatial visualization of the degrees of lung aeration and the various attributes of the image that can be extracted may help physicians and researchers to better assess lung aeration both quantitatively and qualitatively. LISA may have important clinical and research applications on the assessment of global and regional lung aeration and therefore deserves further developments and validation studies. (author)

  18. Automatic system for quantification and visualization of lung aeration on chest computed tomography images: the Lung Image System Analysis - LISA

    Energy Technology Data Exchange (ETDEWEB)

    Felix, John Hebert da Silva; Cortez, Paulo Cesar, E-mail: jhsfelix@gmail.co [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia de Teleinformatica; Holanda, Marcelo Alcantara [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Hospital Universitario Walter Cantidio. Dept. de Medicina Clinica

    2010-12-15

    High Resolution Computed Tomography (HRCT) is the exam of choice for the diagnostic evaluation of lung parenchyma diseases. There is an increasing interest for computational systems able to automatically analyze the radiological densities of the lungs in CT images. The main objective of this study is to present a system for the automatic quantification and visualization of the lung aeration in HRCT images of different degrees of aeration, called Lung Image System Analysis (LISA). The secondary objective is to compare LISA to the Osiris system and also to specific algorithm lung segmentation (ALS), on the accuracy of the lungs segmentation. The LISA system automatically extracts the following image attributes: lungs perimeter, cross sectional area, volume, the radiological densities histograms, the mean lung density (MLD) in Hounsfield units (HU), the relative area of the lungs with voxels with density values lower than -950 HU (RA950) and the 15th percentile of the least density voxels (PERC15). Furthermore, LISA has a colored mask algorithm that applies pseudo-colors to the lung parenchyma according to the pre-defined radiological density chosen by the system user. The lungs segmentations of 102 images of 8 healthy volunteers and 141 images of 11 patients with Chronic Obstructive Pulmonary Disease (COPD) were compared on the accuracy and concordance among the three methods. The LISA was more effective on lungs segmentation than the other two methods. LISA's color mask tool improves the spatial visualization of the degrees of lung aeration and the various attributes of the image that can be extracted may help physicians and researchers to better assess lung aeration both quantitatively and qualitatively. LISA may have important clinical and research applications on the assessment of global and regional lung aeration and therefore deserves further developments and validation studies. (author)

  19. Classifying LISA gravitational wave burst signals using Bayesian evidence

    International Nuclear Information System (INIS)

    Feroz, Farhan; Graff, Philip; Hobson, Michael P; Lasenby, Anthony; Gair, Jonathan R

    2010-01-01

    We consider the problem of characterization of burst sources detected by the Laser Interferometer Space Antenna (LISA) using the multi-modal nested sampling algorithm, MultiNest. We use MultiNest as a tool to search for modelled bursts from cosmic string cusps, and compute the Bayesian evidence associated with the cosmic string model. As an alternative burst model, we consider sine-Gaussian burst signals, and show how the evidence ratio can be used to choose between these two alternatives. We present results from an application of MultiNest to the last round of the Mock LISA Data Challenge, in which we were able to successfully detect and characterize all three of the cosmic string burst sources present in the release data set. We also present results of independent trials and show that MultiNest can detect cosmic string signals with signal-to-noise ratio (SNR) as low as ∼7 and sine-Gaussian signals with SNR as low as ∼8. In both cases, we show that the threshold at which the sources become detectable coincides with the SNR at which the evidence ratio begins to favour the correct model over the alternative.

  20. GRS vs. OMS Calibration in LISA Pathfinder Data Analysis

    International Nuclear Information System (INIS)

    Meshksar, Neda; Ferraioli, Luigi; Mance, Davor; Zweifel, Peter; Giardini, Domenico; Ten Pierick, Jan

    2017-01-01

    On board LISA Pathfinder spacecraft the test mass displacement along the main measurement axis is sensed in two different ways: optically and electrostatically. We have monitored the relative calibration between the two measurements during the mission science phase. The trend sensitivity of the relative calibration has been computed for different physical parameters, such as temperature, magnetic field, test mass bias voltage and current. (paper)

  1. Science with the space-based interferometer eLISA. III: probing the expansion of the universe using gravitational wave standard sirens

    Energy Technology Data Exchange (ETDEWEB)

    Tamanini, Nicola; Caprini, Chiara [Institut de Physique Théorique, CEA-Saclay, CNRS UMR 3681, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France); Barausse, Enrico [Sorbonne Universités, UPMC Université Paris 6, UMR 7095, Institut d' Astrophysique de Paris, 98 bis Bd Arago, 75014 Paris (France); Sesana, Alberto [School of Physics and Astronomy, The University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Klein, Antoine [Department of Physics and Astronomy, The University of Mississippi, University, MS 38677 (United States); Petiteau, Antoine, E-mail: nicola.tamanini@cea.fr, E-mail: chiara.caprini@cea.fr, E-mail: barausse@iap.fr, E-mail: asesana@star.sr.bham.ac.uk, E-mail: aklein@physics.montana.edu, E-mail: antoine.petiteau@apc.univ-paris7.fr [APC, Université Paris Diderot, Observatoire de Paris, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

    2016-04-01

    We investigate the capability of various configurations of the space interferometer eLISA to probe the late-time background expansion of the universe using gravitational wave standard sirens. We simulate catalogues of standard sirens composed by massive black hole binaries whose gravitational radiation is detectable by eLISA, and which are likely to produce an electromagnetic counterpart observable by future surveys. The main issue for the identification of a counterpart resides in the capability of obtaining an accurate enough sky localisation with eLISA. This seriously challenges the capability of four-link (2 arm) configurations to successfully constrain the cosmological parameters. Conversely, six-link (3 arm) configurations have the potential to provide a test of the expansion of the universe up to z ∼ 8 which is complementary to other cosmological probes based on electromagnetic observations only. In particular, in the most favourable scenarios, they can provide a significant constraint on H{sub 0} at the level of 0.5%. Furthermore, (Ω{sub M}, Ω{sub Λ}) can be constrained to a level competitive with present SNIa results. On the other hand, the lack of massive black hole binary standard sirens at low redshift allows to constrain dark energy only at the level of few percent.

  2. Professor Lisa Aranson on JA Green (a pioonier artist photographer ...

    African Journals Online (AJOL)

    Jonathan Adagogo Green's photographic and artistic contributions working in his countryside, the Niger Delta of Nigeria is reviewed by Professor Lisa Aranson. Aranson in a public lecture presentation on the stand-point of art history thinks of J.A. Green as having operated in two worlds of which he is said to have initiated in ...

  3. arXiv Probing non-Gaussian Stochastic Gravitational Wave Backgrounds with LISA

    CERN Document Server

    Bartolo, Nicola; Figueroa, Daniel G.; Garcia-Bellido, Juan; Peloso, Marco; Pieroni, Mauro; Ricciardone, Angelo; Sakellariadou, Mairi; Sorbo, Lorenzo; Tasinato, Gianmassimo

    The stochastic gravitational wave background (SGWB) contains a wealth of information on astrophysical and cosmological processes. A major challenge of upcoming years will be to extract the information contained in this background and to disentangle the contributions of different sources. In this paper we provide the formalism to extract, from the correlation of three signals in the Laser Interferometer Space Antenna (LISA), information about the tensor three-point function, which characterizes the non-Gaussian properties of the SGWB. Compared to the two-point function, the SGWB three-point function has a richer dependence on the gravitational wave momenta and chiralities, and a larger number of signal channels. It can be used therefore as a powerful discriminator between different models. We provide LISA's response functions to a general SGWB three-point function. As examples, we study in full detail the cases of an equilateral and squeezed SGWB bispectra, and provide the explicit form of the response functio...

  4. Revised electrostatic model of the LISA Pathfinder inertial sensor

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Nico [Astrium GmbH, 88039 Friedrichshafen (Germany); Fichter, Walter, E-mail: nico.brandt@astrium.eads.ne [iFR, Universitaet Stuttgart, Pfaffenwaldring 7a, 70569 Stuttgart (Germany)

    2009-03-01

    A comprehensive electrostatic finite-element (FE) analysis of the LISA Pathfinder Inertial Sensor (IS) has been carried out at Astrium GmbH. Starting with a detailed geometrical model of the IS housing and test mass (TM) flight units, FE results were derived from multiple analyses runs applying the Maxwell 3D field simulation software. The electrostatic forces and torques on the TM in 6DoF, as well as all non-negligible capacitances between the TM, the 18 electrodes, and the housing, have been extracted for different TM translations and rotations. The results of the FE analyses were expected to confirm the existing IS electrostatic model predictions used for performance analysis, simulations, and on-board algorithms. Major discrepancies were found, however, between the results and the model used so far. In general, FE results give considerably larger capacitance values than the equivalent infinite non-parallel plate estimates. In contrast, the FE derived forces and torques are in general significantly lower compared to the analytic IS electrostatic model predictions. In this paper, these results are discussed in detail and the reasons for the deviations are elaborated. Based on these results, an adapted analytic IS electrostatic model is proposed that reflects the electrostatic forces, torques, and stiffness values in the LISA Pathfinder IS significantly more accurate.

  5. Revised electrostatic model of the LISA Pathfinder inertial sensor

    International Nuclear Information System (INIS)

    Brandt, Nico; Fichter, Walter

    2009-01-01

    A comprehensive electrostatic finite-element (FE) analysis of the LISA Pathfinder Inertial Sensor (IS) has been carried out at Astrium GmbH. Starting with a detailed geometrical model of the IS housing and test mass (TM) flight units, FE results were derived from multiple analyses runs applying the Maxwell 3D field simulation software. The electrostatic forces and torques on the TM in 6DoF, as well as all non-negligible capacitances between the TM, the 18 electrodes, and the housing, have been extracted for different TM translations and rotations. The results of the FE analyses were expected to confirm the existing IS electrostatic model predictions used for performance analysis, simulations, and on-board algorithms. Major discrepancies were found, however, between the results and the model used so far. In general, FE results give considerably larger capacitance values than the equivalent infinite non-parallel plate estimates. In contrast, the FE derived forces and torques are in general significantly lower compared to the analytic IS electrostatic model predictions. In this paper, these results are discussed in detail and the reasons for the deviations are elaborated. Based on these results, an adapted analytic IS electrostatic model is proposed that reflects the electrostatic forces, torques, and stiffness values in the LISA Pathfinder IS significantly more accurate.

  6. Effects of different eLISA-like configurations on massive black hole parameter estimation

    Science.gov (United States)

    Porter, Edward K.

    2015-09-01

    As the theme for the future L3 Cosmic Vision mission, ESA has recently chosen the "Gravitational Wave Universe." Within this program, a mission concept called eLISA has been proposed. This observatory has a current initial configuration consisting of four laser links between the three satellites, which are separated by a distance of one million kilometers, constructing a single-channel Michelson interferometer. However, the final configuration for the observatory will not be fixed until the end of this decade. With this in mind, we investigate the effect of different eLISA-like configurations on massive black hole detections. This work compares the results of a Bayesian inference study of 120 massive black hole binaries out to a redshift of z ˜13 for a 106 km arm length eLISA with four and six links, as well as a 2 ×106 km arm length observatory with four links. We demonstrate that the original eLISA configuration should allow us to recover the luminosity distance of the source with an error of less than 10% out to a redshift of z ˜4 , and a sky error box of Δ Ω ≤102 deg2 out to z ˜0.1 . In contrast, both alternative configurations suggest that we should be able to conduct the same parameter recovery with errors of less than 10% in luminosity distance out to z ˜12 and Δ Ω ≤102 deg2 out to z ˜0.4 . Using the information from these studies, we also infer that if we were able to construct a 2 Gm, six-link detector, the above values would shift to z ˜20 for luminosity distance and z ˜0.9 for sky error. While the final configuration will also be dependent on both technological and financial considerations, our study suggests that increasing the size of a two-arm detector is a viable alternative to the inclusion of a third arm in a smaller detector. More importantly, this work further suggests no clear scientific loss between either choice.

  7. Lifetime testing UV LEDs for use in the LISA charge management system

    Science.gov (United States)

    Hollington, D.; Baird, J. T.; Sumner, T. J.; Wass, P. J.

    2017-10-01

    As a future charge management light source, UV light-emitting diodes (UV LEDs) offer far superior performance in a range of metrics compared to the mercury lamps used in the past. As part of a qualification program a number of short wavelength UV LEDs have been subjected to a series of lifetime tests for potential use on the laser interferometer space antenna (LISA) mission. These tests were performed at realistic output levels for both fast and continuous discharging in either a DC or pulsed mode of operation and included a DC fast discharge test spanning 50 days, a temperature dependent pulsed fast discharge test spanning 21 days and a pulsed continuous discharge test spanning 507 days. Two types of UV LED have demonstrated lifetimes equivalent to over 25 years of realistic mission usage with one type providing a baseline for LISA and the other offering a backup solution.

  8. Lifetime testing UV LEDs for use in the LISA charge management system

    International Nuclear Information System (INIS)

    Hollington, D; Baird, J T; Sumner, T J; Wass, P J

    2017-01-01

    As a future charge management light source, UV light-emitting diodes (UV LEDs) offer far superior performance in a range of metrics compared to the mercury lamps used in the past. As part of a qualification program a number of short wavelength UV LEDs have been subjected to a series of lifetime tests for potential use on the laser interferometer space antenna (LISA) mission. These tests were performed at realistic output levels for both fast and continuous discharging in either a DC or pulsed mode of operation and included a DC fast discharge test spanning 50 days, a temperature dependent pulsed fast discharge test spanning 21 days and a pulsed continuous discharge test spanning 507 days. Two types of UV LED have demonstrated lifetimes equivalent to over 25 years of realistic mission usage with one type providing a baseline for LISA and the other offering a backup solution. (paper)

  9. LISA Pathfinder E2E performance simulation: optical and self-gravity stability analysis

    Science.gov (United States)

    Brandt, N.; Fichter, W.; Kersten, M.; Lucarelli, S.; Montemurro, F.

    2005-05-01

    End-to-end (E2E) modelling and simulation, i.e. verifying the science performance of LISA Pathfinder (spacecraft and payload), is mandatory in order to minimize mission risks. In this paper, focus is on two particular applications of the E2E performance simulator currently being developed at EADS Astrium GmbH: the opto-dynamical stability and the self-gravity disturbance stability analysis. The E2E models applied here comprise the opto-dynamical modelling of the optical metrology systems (OMS) laser interferometry, the thermo-elastic distortion modelling of the OMS optical elements and the self-gravity disturbance model accounting for structural distortions. Preliminary analysis results are presented in detail, identifying shortcomings of the current LISA technology package (LTP) mounting baseline. As a consequence, the design is now being revised.

  10. LISA Pathfinder E2E performance simulation: optical and self-gravity stability analysis

    International Nuclear Information System (INIS)

    Brandt, N; Fichter, W; Kersten, M; Lucarelli, S; Montemurro, F

    2005-01-01

    End-to-end (E2E) modelling and simulation, i.e. verifying the science performance of LISA Pathfinder (spacecraft and payload), is mandatory in order to minimize mission risks. In this paper, focus is on two particular applications of the E2E performance simulator currently being developed at EADS Astrium GmbH: the opto-dynamical stability and the self-gravity disturbance stability analysis. The E2E models applied here comprise the opto-dynamical modelling of the optical metrology systems (OMS) laser interferometry, the thermo-elastic distortion modelling of the OMS optical elements and the self-gravity disturbance model accounting for structural distortions. Preliminary analysis results are presented in detail, identifying shortcomings of the current LISA technology package (LTP) mounting baseline. As a consequence, the design is now being revised

  11. Actuation crosstalk in free-falling systems: Torsion pendulum results for the engineering model of the LISA pathfinder gravitational reference sensor

    Science.gov (United States)

    Bassan, M.; Cavalleri, A.; De Laurentis, M.; De Marchi, F.; De Rosa, R.; Di Fiore, L.; Dolesi, R.; Finetti, N.; Garufi, F.; Grado, A.; Hueller, M.; Marconi, L.; Milano, L.; Minenkov, Y.; Pucacco, G.; Stanga, R.; Vetrugno, D.; Visco, M.; Vitale, S.; Weber, W. J.

    2018-01-01

    In this paper we report on measurements on actuation crosstalk, relevant to the gravitational reference sensors for LISA Pathfinder and LISA. In these sensors, a Test Mass (TM) falls freely within a system of electrodes used for readout and control. These measurements were carried out on ground with a double torsion pendulum that allowed us to estimate both the torque injected into the sensor when a control force is applied and, conversely, the force leaking into the translational degree of freedom due to the applied torque.The values measured on our apparatus (the engineering model of the LISA Pathfinder sensor) agree to within 0.2% (over a maximum measured crosstalk of 1%) with predictions of a mathematical model when measuring force to torque crosstalk, while it is somewhat larger than expected (up to 3.5%) when measuring torque to force crosstalk. However, the values in the relevant range, i.e. when the TM is well centered ( ± 10 μm) in the sensor, remain smaller than 0.2%, satisfying the LISA Pathfinder requirements.

  12. Detection of Double White Dwarf Binaries with Gaia, LSST and eLISA

    Science.gov (United States)

    Korol, V.; Rossi, E. M.; Groot, P. J.

    2017-03-01

    According to simulations around 108 double degenerate white dwarf binaries are expected to be present in the Milky Way. Due to their intrinsic faintness, the detection of these systems is a challenge, and the total number of detected sources so far amounts only to a few tens. This will change in the next two decades with the advent of Gaia, the LSST and eLISA. We present an estimation of how many compact DWDs with orbital periods less than a few hours we will be able to detect 1) through electromagnetic radiation with Gaia and LSST and 2) through gravitational wave radiation with eLISA. We find that the sample of simultaneous electromagnetic and gravitational waves detections is expected to be substantial, and will provide us a powerful tool for probing the white dwarf astrophysics and the structure of the Milky Way, letting us into the era of multi-messenger astronomy for these sources.

  13. The magnetic diagnostics subsystem of the LISA Technology Package

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Aguilo, M; Garcia-Berro, E [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, 08860 Castelldefels (Spain); Lobo, A; Mateos, N; Sanjuan, J, E-mail: marc.diaz.aguilo@fa.upc.ed [Institut d' Estudis Espacials de Catalunya, c/Gran Capita 2-4, Edif. Nexus 104, 08034 Barcelona (Spain)

    2010-05-01

    The Magnetic Diagnostics Subsystem of the LISA Technology Package (LTP) on board the LISA Pathfinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at the positions they occupy. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses. Therefore, an interpolation method must be implemented to obtain this information. However, such interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable, and the number of magnetometer channels does not provide sufficient data to go beyond that poor approximation. Recent research points to a possible alternative to address the magnetic interpolation problem by means of neural network algorithms. The key point of this approach is the ability neural networks have to learn from suitable training data representing the magnetic field behaviour. Despite the large distance to the test masses and the insufficient magnetic readings, artificial neural networks are able to significantly reduce the estimation error to acceptable levels. The learning efficiency can be best improved by making use of data obtained from on-ground measurements prior to mission launch in all relevant satellite locations and under real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

  14. The magnetic diagnostics subsystem of the LISA Technology Package

    International Nuclear Information System (INIS)

    Diaz-Aguilo, M; Garcia-Berro, E; Lobo, A; Mateos, N; Sanjuan, J

    2010-01-01

    The Magnetic Diagnostics Subsystem of the LISA Technology Package (LTP) on board the LISA Pathfinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at the positions they occupy. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses. Therefore, an interpolation method must be implemented to obtain this information. However, such interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable, and the number of magnetometer channels does not provide sufficient data to go beyond that poor approximation. Recent research points to a possible alternative to address the magnetic interpolation problem by means of neural network algorithms. The key point of this approach is the ability neural networks have to learn from suitable training data representing the magnetic field behaviour. Despite the large distance to the test masses and the insufficient magnetic readings, artificial neural networks are able to significantly reduce the estimation error to acceptable levels. The learning efficiency can be best improved by making use of data obtained from on-ground measurements prior to mission launch in all relevant satellite locations and under real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

  15. Search for a stochastic gravitational-wave signal in the second round of the Mock LISA Data Challenges

    International Nuclear Information System (INIS)

    Robinson, E L; Vecchio, A; Romano, J D

    2008-01-01

    The analysis method currently proposed to search for isotropic stochastic radiation with the Laser Interferometer Space Antenna (LISA) relies on the combined use of two LISA channels, one of which is insensitive to gravitational waves, such as the symmetrized Sagnac. For this method to work, it is essential to know how the instrumental noise power in the two channels are related to one another; however, no quantitative estimates of this key information are available to date. The purpose of our study is to assess the performance of the symmetrized Sagnac method for different levels of prior information regarding the instrumental noise. We develop a general approach in the framework of Bayesian inference and an end-to-end analysis algorithm based on Markov chain Monte Carlo methods to compute the posterior probability density functions of the relevant model parameters. We apply this method to data released as part of the second round of the Mock LISA Data Challenges. For the selected (and somewhat idealized) example cases considered here, we find that for a signal whose amplitude dominates the instrumental noise by a factor ∼25, a prior uncertainty of a factor ∼2 in the ratio between the power of the instrumental noise contributions in the two channels allows for the detection of isotropic stochastic radiation. More importantly, we provide a framework for more realistic studies of LISA's performance and development of analysis techniques in the context of searches for stochastic signals

  16. Observing extreme-mass-ratio inspirals with eLISA/NGO

    OpenAIRE

    Gair, Jonathan R; Porter, Edward K

    2012-01-01

    The extreme-mass-ratio inspirals (EMRIs) of stellar mass compact objects into massive black holes in the centres of galaxies are an important source of low-frequency gravitational waves for space-based detectors. We discuss the prospects for detecting these sources with the evolved Laser Interferometer Space Antenna (eLISA), recently proposed as an ESA mission candidate under the name NGO. We show that NGO could observe a few tens of EMRIs over its two year mission lifetime at redshifts z < 0...

  17. Fundamentals of the LISA stable flight formation

    International Nuclear Information System (INIS)

    Dhurandhar, S V; Nayak, K Rajesh; Koshti, S; Vinet, J-Y

    2005-01-01

    The joint NASA-ESA mission, LISA, relies crucially on the stability of the three-spacecraft constellation. Each of the spacecraft is in heliocentric orbit forming a stable triangle. In this paper we explicitly show with the help of the Clohessy-Wiltshire equations that any configuration of spacecraft lying in the planes making angles of ±60 0 with the ecliptic and given suitable initial velocities within the plane, can be made stable in the sense that the inter-spacecraft distances remain constant to first order in the dimensions of the configuration compared with the distance to the Sun. Such analysis would be useful in order to carry out theoretical studies on the optical links, simulators, etc

  18. Constraints on LISA Pathfinder's Self-Gravity: Design Requirements, Estimates and Testing Procedures

    Science.gov (United States)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, M.; Brandt, Nico; Bursi, Alessandro; Slutsky. J.; hide

    2016-01-01

    LISA Pathfinder satellite was launched on 3 December 2015 toward the Sun Earth first Lagrangian point (L1) where the LISA Technology Package (LTP), which is the main science payload, will be tested. LTP achieves measurements of differential acceleration of free-falling test masses (TMs) with sensitivity below 3 x 10(exp -14) m s(exp -2) Hz(exp - 1/2) within the 130 mHz frequency band in one dimension. The spacecraft itself is responsible for the dominant differential gravitational field acting on the two TMs. Such a force interaction could contribute a significant amount of noise and thus threaten the achievement of the targeted free-fall level. We prevented this by balancing the gravitational forces to the sub nm s(exp -2) level, guided by a protocol based on measurements of the position and the mass of all parts that constitute the satellite, via finite element calculation tool estimates. In this paper, we will introduce the gravitational balance requirements and design, and then discuss our predictions for the balance that will be achieved in flight.

  19. Searching for massive black hole binaries in the first Mock LISA Data Challenge

    International Nuclear Information System (INIS)

    Cornish, Neil J; Porter, Edward K

    2007-01-01

    The Mock LISA Data Challenge is a worldwide effort to solve the LISA data analysis problem. We present here our results for the massive black hole binary (BBH) section of round 1. Our results cover challenge 1.2.1, where the coalescence of the binary is seen, and challenge 1.2.2, where the coalescence occurs after the simulated observational period. The data stream is composed of Gaussian instrumental noise plus an unknown BBH waveform. Our search algorithm is based on a variant of the Markov chain Monte Carlo method that uses Metropolis-Hastings sampling and thermostated frequency annealing. We present results from the training data sets where we know the parameter values a priori and the blind data sets where we were informed of the parameter values after the challenge had finished. We demonstrate that our algorithm is able to rapidly locate the sources, accurately recover the source parameters and provide error estimates for the recovered parameters

  20. Numerical code to determine the particle trapping region in the LISA machine

    International Nuclear Information System (INIS)

    Azevedo, M.T. de; Raposo, C.C. de; Tomimura, A.

    1984-01-01

    A numerical code is constructed to determine the trapping region in machine like LISA. The variable magnetic field is two deimensional and is coupled to the Runge-Kutta through the Tchebichev polynomial. Various particle orbits including particle interactions were analysed. Beside this, a strong electric field is introduced to see the possible effects happening inside the plasma. (Author) [pt

  1. The End of Panopticon/panopticism in William Gibson’s Mona Lisa Overdrive : A Baudrillardian Reading

    Directory of Open Access Journals (Sweden)

    Hanieh Zaltash

    2014-11-01

    Full Text Available This paper seeks to examine William Gibson’s Mona Lisa Overdrive as a cyberpunk novel in the light of Baudrillard’s theory of “Simulation”. Jean Baudrillard believes that reality is replaced by “hyperreality” and human beings live in a total “simulation” in which everything, such as power might be simulated. Thus, according to Baudrillard, power exists just as “the simulation of power” which is the result of “the circularization of power” between the dominator and the dominated. Baudrillard delineates “the circularization of power” through criticizing Michel Foucault’s theories regarding power and panopticon, and introduces “the end of panopticon” which is centered upon the reversibility of the positions of the observer and the observed. In a meticulous analysis of TV performance of the Loud family in 1971, Baudrillard claims that the panoptic system is ended through playing on the opposition of seeing and being seen. The findings suggest that Mona Lisa Overdrive depicts “the end of panopticon,” in a sense that Angie Mitchell in this novel can be considered as a counterpart for Baudrillard’s instance of the Loud family. Indeed, this study attempts to elucidate “the end of panopticon” in Mona Lisa Overdrive (1988 through scrutinizing Angie Mitchell’s way of living.

  2. Supermassive Black Holes as Revealed by LISA: How Gravitational Wave Astronomy Will be a Game Changer

    Science.gov (United States)

    Holley-Bockelmann, Kelly

    2018-04-01

    Astronomers now know that supermassive black holes are in nearly every galaxy.Though these black holes are an observational certainty, nearly every aspect of their evolution -- from their birth, to their fuel source, to their basic dynamics -- is a matter of lively debate. Fortunately, LISA, a space-based gravitational wave observatory set to launch in 2034, will revolutionize this field by providing data that is complementary to electromagnetic observations as well as data in regimes that are electromagnetically dark. This talk will touch on our current understanding of how SMBHs form, evolve, and alter their galaxy host, and will outline the theoretical, computational and observational work needed to make the most of LISA observations.

  3. Non-linear quantization error reduction for the temperature measurement subsystem on-board LISA Pathfinder

    Science.gov (United States)

    Sanjuan, J.; Nofrarias, M.

    2018-04-01

    Laser Interferometer Space Antenna (LISA) Pathfinder is a mission to test the technology enabling gravitational wave detection in space and to demonstrate that sub-femto-g free fall levels are possible. To do so, the distance between two free falling test masses is measured to unprecedented sensitivity by means of laser interferometry. Temperature fluctuations are one of the noise sources limiting the free fall accuracy and the interferometer performance and need to be known at the ˜10 μK Hz-1/2 level in the sub-millihertz frequency range in order to validate the noise models for the future space-based gravitational wave detector LISA. The temperature measurement subsystem on LISA Pathfinder is in charge of monitoring the thermal environment at key locations with noise levels of 7.5 μK Hz-1/2 at the sub-millihertz. However, its performance worsens by one to two orders of magnitude when slowly changing temperatures are measured due to errors introduced by analog-to-digital converter non-linearities. In this paper, we present a method to reduce this effect by data post-processing. The method is applied to experimental data available from on-ground validation tests to demonstrate its performance and the potential benefit for in-flight data. The analog-to-digital converter effects are reduced by a factor between three and six in the frequencies where the errors play an important role. An average 2.7 fold noise reduction is demonstrated in the 0.3 mHz-2 mHz band.

  4. Laser frequency stabilization and stray light issues for LISA and other future multi-spacecraft missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "The Laser Interferometer Space Antenna (LISA) is a joint NASA/ESA project which will use laser interferometry between drag-free proof masses to measure...

  5. Lisa B Signorello, ScD, ScM | Division of Cancer Prevention

    Science.gov (United States)

    Lisa Signorello is the Director and Chief of the Cancer Prevention Fellowship Program (CPFP) Branch in the National Cancer Institute's Division of Cancer Prevention. Dr. Signorello served as Deputy Director of the CPFP from August 2014 to November 2017 and came to the NCI after having held academic positions at the Harvard School of Public Health, Harvard Medical School, and Vanderbilt University, as well as having had significant private sector research experience. |

  6. Principles, operations, and expected performance of the LISA Pathfinder charge management system

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, T [Astrium GmbH, 88039 Friedrichshafen (Germany); Fichter, W [iFR, Universitaet Stuttgart, Pfaffenwaldring 7a, 70569 Stuttgart (Germany); Schulte, M [Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BZ (United Kingdom); Vitale, S, E-mail: tobias.ziegler@astrium.eads.ne [Department of Physics, University of Trento, 38050 Povo, Trento (Italy)

    2009-03-01

    The test masses of LISA Pathfinder are free flying and therefore not grounded to the spacecraft by a wire. Because of galactic cosmic rays, solar energetic particles, and unknown microscopic surface effects during initial test mass release, an unacceptable level of absolute charge might be present on the test masses. A charged test mass can endanger transition to high accuracy control modes which are required for science experiments. Furthermore, charged test masses introduce unwanted disturbance accelerations for example due to Coulomb interactions with surrounding conducting surfaces. The charge management system is designed to discharge the test masses up to a tolerable level of absolute charge such that the mission goal can be achieved. It is therefore an essential part of the experiments to be performed with the LISA Technology Package. The paper describes charge management tasks to be performed on board the spacecraft and summarizes the principles of charge measurement and discharge control. An overview of the experiment operations is given where the interconnection of operational charge management system modes and operational modes of the drag-free, suspension and attitude control system is considered. Simulated performance results are presented.

  7. A constrained Metropolis-Hastings search for EMRIs in the Mock LISA Data Challenge 1B

    International Nuclear Information System (INIS)

    Gair, Jonathan R; Porter, Edward; Babak, Stanislav; Barack, Leor

    2008-01-01

    We describe a search for the extreme-mass-ratio inspiral sources in the Round 1B Mock LISA Data Challenge data sets. The search algorithm is a Monte Carlo search based on the Metropolis-Hastings algorithm, but also incorporates simulated, thermostated and time annealing, plus a harmonic identification stage designed to reduce the chance of the chain locking onto secondary maxima. In this paper, we focus on describing the algorithm that we have been developing. We give the results of the search of the Round 1B data, although parameter recovery has improved since that deadline. Finally, we describe several modifications to the search pipeline that we are currently investigating for incorporation in future searches

  8. The LISA Pathfinder interferometry-hardware and system testing

    Energy Technology Data Exchange (ETDEWEB)

    Audley, H; Danzmann, K; MarIn, A Garcia; Heinzel, G; Monsky, A; Nofrarias, M; Steier, F; Bogenstahl, J [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik und Universitaet Hannover, 30167 Hannover (Germany); Gerardi, D; Gerndt, R; Hechenblaikner, G; Johann, U; Luetzow-Wentzky, P; Wand, V [EADS Astrium GmbH, Friedrichshafen (Germany); Antonucci, F [Dipartimento di Fisica, Universita di Trento and INFN, Gruppo Collegato di Trento, 38050 Povo, Trento (Italy); Armano, M [European Space Astronomy Centre, European Space Agency, Villanueva de la Canada, 28692 Madrid (Spain); Auger, G; Binetruy, P [APC UMR7164, Universite Paris Diderot, Paris (France); Benedetti, M [Dipartimento di Ingegneria dei Materiali e Tecnologie Industriali, Universita di Trento and INFN, Gruppo Collegato di Trento, Mesiano, Trento (Italy); Boatella, C, E-mail: antonio.garcia@aei.mpg.de [CNES, DCT/AQ/EC, 18 Avenue Edouard Belin, 31401 Toulouse, Cedex 9 (France)

    2011-05-07

    Preparations for the LISA Pathfinder mission have reached an exciting stage. Tests of the engineering model (EM) of the optical metrology system have recently been completed at the Albert Einstein Institute, Hannover, and flight model tests are now underway. Significantly, they represent the first complete integration and testing of the space-qualified hardware and are the first tests on an optical system level. The results and test procedures of these campaigns will be utilized directly in the ground-based flight hardware tests, and subsequently during in-flight operations. In addition, they allow valuable testing of the data analysis methods using the MATLAB-based LTP data analysis toolbox. This paper presents an overview of the results from the EM test campaign that was successfully completed in December 2009.

  9. Energy transport in mirror machine LISA at electron cyclotron resonance

    International Nuclear Information System (INIS)

    Cunha Rapozo, C. da; Serbeto, A.; Torres-Silva, H.

    1993-01-01

    It is shown that a classical transport calculation is adequate to predict the steady state temperature of the RF produced plasma in LISA machine for both large and small resonant volumes. Temperature anisotropy ranging from 55 to 305 was found which was larger for small resonant volume, and the temperature relaxation was larger at large resonant one. This agrees with the fact that there is a Coulomb relaxation ν c which is proportional to T e -3/2 . It is also shown that the fitting parameter alpha is larger for large resonant volume than for small resonant one. (L.C.J.A.)

  10. Auxiliary functions of the LISA laser link: ranging, clock noise transfer and data communication

    International Nuclear Information System (INIS)

    Heinzel, Gerhard; Esteban, Juan Jose; Barke, Simon; Otto, Markus; Wang Yan; Garcia, Antonio F; Danzmann, Karsten

    2011-01-01

    The Laser Interferometer Space Antenna (LISA) is required to reduce two important noise sources by post-processing on the ground using time-delay interferometry (TDI): phase noise of the on-board reference clocks and laser frequency noise. To achieve the desired suppression, the TDI algorithm needs measurements of the differential clock noise between any two spacecraft and inter-spacecraft ranging measurements with at least 1 m accuracy, which is beyond the precision of ground-based measurements for deep space missions. Therefore, we need on-board measurements by transmitting clock noise and ranging information between the spacecraft as auxiliary functions of the laser link. This paper reports our current experimental results in clock noise transfer and ranging for noise subtraction via post-processing as well as additional data transfer.

  11. Simulation of the charging process of the LISA test masses due to solar flares

    International Nuclear Information System (INIS)

    Vocca, H; Grimani, C; Amico, P; Bosi, L; Marchesoni, F; Punturo, M; Travasso, F; Barone, M; Stanga, R; Vetrano, F; Vicere, A

    2004-01-01

    Cosmic-ray and solar high energy particles penetrate the LISA experiment test masses. Consequently, an electric charge accumulates in the bodies of the masses, generating spurious Coulomb forces between the masses and the surrounding electrodes. This process increases the noise level of the experiment. We have estimated the amount of charge deposited per second on the LISA test masses by solar flares and primary cosmic-ray protons at solar minimum. The simulation has been carried out with the Fluka Monte Carlo program. A simplified geometry for the experiment has been considered. We have found a net charging rate of 37 ± 1 e + /s for primary protons at solar minimum between 0.1 and 1000 GeV/n. The amount of charge released by a medium-strong solar flare, like that of 16 February 1984, is 10 732 ± 30 e + /s in the energy range 0.1-10 GeV/n. This value increases or decreases by approximately one order of magnitude for strong (weak) solar flares

  12. LISA - a powerful program package for LIstmode and Spectral data Analysis

    International Nuclear Information System (INIS)

    Oberstedt, A.; Hambsch, F.J.

    1994-01-01

    LISA is a graphical program package which enables both off-line listmode and spectral data evaluation as well as on-line monitoring while multi-parameter experiments are running. It can be executed on every computer with a UNIX operating system and an X-WINDOW environment, running PV-WAVE from Visual Numerics Incorporation. This package is basically written in the language PV-WAVE CL, but integration of procedures written in the C-language and execution of UNIX shell commands lead to an additional increase of performance. (orig.)

  13. Développement et exploitation d'un simulateur électro-optique pour le futur détecteur spatial à ondes gravitationnelles eLISA

    OpenAIRE

    Gruning , Pierre

    2015-01-01

    Gravitational waves will offer a new window to the universe. Their detection by ground based detectors should arrive soon and the future space based interferometer eLISA will allow to do gravitational wave astronomy in order to get unique informations on their sources wether black holes, neutron stars, the Big Bang etc. The effect of a gravitational wave is an extremely weak variation of distance, it will require a very performant detector. That’s why eLISA should reach picometer precision wi...

  14. Massive Black Hole Mergers: Can We "See" what LISA will "Hear"?

    Science.gov (United States)

    Centrella, Joan

    2010-01-01

    The final merger of massive black holes produces strong gravitational radiation that can be detected by the space-borne LISA. If the black hole merger takes place in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts of the final merger requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We will review current efforts to simulate these systems, and discuss possibilities for observing the electromagnetic signals they produce.

  15. Measuring fN force variations in the presence of constant nN forces: a torsion pendulum ground test of the LISA Pathfinder free-fall mode

    Science.gov (United States)

    Russano, G.; Cavalleri, A.; Cesarini, A.; Dolesi, R.; Ferroni, V.; Gibert, F.; Giusteri, R.; Hueller, M.; Liu, L.; Pivato, P.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Weber, W. J.

    2018-02-01

    LISA Pathfinder is a differential accelerometer with the main goal being to demonstrate the near perfect free-fall of reference test masses, as is needed for an orbiting gravitational wave observatory, with a target sensitivity of 30 fm s‑2 Hz-1/2 at 1 mHz. Any lasting background differential acceleration between the two test masses must be actively compensated, and noise associated with the applied actuation force can be a dominant source of noise. To remove this actuation, and the associated force noise, a ‘free-fall’ actuation control scheme has been designed; actuation is limited to brief impulses, with both test masses in free-fall in the time between the impulses, allowing measurement of the remaining acceleration noise sources. In this work, we present an on-ground torsion pendulum testing campaign of this technique and associated data analysis algorithms at a level nearing the sub-femto-g/\\sqrtHz performance required for LISA Pathfinder.

  16. Nested-PCR and a new ELISA-based NovaLisa test kit for malaria diagnosis in an endemic area of Thailand.

    Science.gov (United States)

    Thongdee, Pimwan; Chaijaroenkul, Wanna; Kuesap, Jiraporn; Na-Bangchang, Kesara

    2014-08-01

    Microscopy is considered as the gold standard for malaria diagnosis although its wide application is limited by the requirement of highly experienced microscopists. PCR and serological tests provide efficient diagnostic performance and have been applied for malaria diagnosis and research. The aim of this study was to investigate the diagnostic performance of nested PCR and a recently developed an ELISA-based new rapid diagnosis test (RDT), NovaLisa test kit, for diagnosis of malaria infection, using microscopic method as the gold standard. The performance of nested-PCR as a malaria diagnostic tool is excellent with respect to its high accuracy, sensitivity, specificity, and ability to discriminate Plasmodium species. The sensitivity and specificity of nested-PCR compared with the microscopic method for detection of Plasmodium falciparum, Plasmodium vivax, and P. falciparum/P. vivax mixed infection were 71.4 vs 100%, 100 vs 98.7%, and 100 vs 95.0%, respectively. The sensitivity and specificity of the ELISA-based NovaLisa test kit compared with the microscopic method for detection of Plasmodium genus were 89.0 vs 91.6%, respectively. NovaLisa test kit provided comparable diagnostic performance. Its relatively low cost, simplicity, and rapidity enables large scale field application.

  17. On-orbit alignment and diagnostics for the LISA Technology Package

    International Nuclear Information System (INIS)

    MarIn, A F GarcIa; Wand, V; Steier, F; Cervantes, F Guzman; Bogenstahl, J; Jennrich, O; Heinzel, G; Danzmann, K

    2006-01-01

    This paper presents a procedure to perform fully autonomous on-orbit alignment of the interferometer on board the LISA Technology Package (LTP). LTP comprises two free-floating test masses as inertial sensors that additionally serve as end mirrors of a set of interferometers. From the output signals of the interferometers, a subset has been selected to obtain alignment information of the test masses. Based on these signals, an alignment procedure was developed and successfully tested on the engineering model of the optical bench. Furthermore, operation procedures for the characterization of critical on-orbit properties of the optical metrology system (e.g. fibre noise) have been established

  18. Commissioning and operating experience with the LISA superconducting accelerator

    International Nuclear Information System (INIS)

    Castellano, M.; Ferrario, M.; Minestrini, M.; Patteri, P.; Tazzioli, F.; Kulinski, S.

    1996-06-01

    The commissioning of the LISA superconducting (SC) RF electron linac at INFN Frascati Laboratories has been concluded although, due to a change in program priorities, the full possibilities of the machine have not been exploited. In this report the authors illustrate the results achieved so far and the difficulties encountered in commissioning, with the hope that this material might be some of help to those who intend to start the enterprise of building a SC linac in a non specialized environment. The part concerning the SC system is particularly stressed, but a relevant attention is also devoted to the traditional room temperature injector, the proper setting of which is fundamental to achieving the high beam quality that such a machine allows

  19. Playing Harry Potter: Essays and interviews on fandom and performance, edited by Lisa S. Brenner

    Directory of Open Access Journals (Sweden)

    Abigail De Kosnik

    2016-09-01

    Full Text Available Lisa S. Brenner, editor. Playing Harry Potter: Essays and interviews on fandom and performance. Jefferson, NC: McFarland, 2015, paperback, $29.95 (238p ISBN 978-0-7864-9657-0; e-book $14.43 (5374 KB ISBN 978-1-4766-2136-4, ASIN B012E9G0R6.

  20. LISA Pathfinder drag-free control and system implications

    International Nuclear Information System (INIS)

    Fichter, Walter; Gath, Peter; Vitale, Stefano; Bortoluzzi, Daniele

    2005-01-01

    The top-level requirement of the LISA Pathfinder mission is the verification of pure relative free fall between two test masses with an accuracy of about 3 x 10 -14 m s -2 Hz -1/2 in a measurement bandwidth between 1 mHz and 30 mHz. The drag-free control system is one of the key technology elements that shall be verified. Its design is strongly connected to the overall system and experimental design, in particular, via the following issues: the differential test mass motion and thus the science measurements depend on the control system; design constraints, such as negative stiffness of test masses and electrostatic actuation cross-talk, have an impact on science and control system performance; derived requirements for control system components, in particular, the micro-propulsion system, must be within reasonable and feasible limits. In this paper, the control design approach is outlined and the system-related issues are addressed

  1. Selective metallization of polymers using laser induced surface activation (LISA)—characterization and optimization of porous surface topography

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard; De Grave, Arnaud

    2011-01-01

    Laser induced selective activation (LISA) is a molded interconnected devices technique for selective metallization of polymers. On the working piece, only the laser-machined area can be metalized in the subsequent plating. The principle of the technology is introduced. Surface analysis was perfor...

  2. Theory and modelling of the magnetic field measurement in LISA PathFinder

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Aguilo, M; Garcia-Berro, E [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, c/Esteve Terrades, 5, 08860 Castelldefels (Spain); Lobo, A, E-mail: marc.diaz.aguilo@fa.upc.ed [Institut d' Estudis Espacials de Catalunya, c/Gran Capita 2-4, Edif. Nexus 104, 08034 Barcelona (Spain)

    2010-02-07

    The magnetic diagnostics subsystem of the LISA Technology Package (LTP) on board the LISA PathFinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at their respective positions. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses, and hence an interpolation method must be designed and implemented to obtain the values of the magnetic field at these positions. However, such an interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable while, on the other hand, the number of magnetometer channels do not provide sufficient data to go beyond the linear approximation. We describe an alternative method to address this issue, by means of neural network algorithms. The key point in this approach is the ability of neural networks to learn from suitable training data representing the behaviour of the magnetic field. Despite the relatively large distance between the test masses and the magnetometers, and the insufficient number of data channels, we find that our artificial neural network algorithm is able to reduce the estimation errors of the field and gradient down to levels below 10%, a quite satisfactory result. Learning efficiency can be best improved by making use of data obtained in on-ground measurements prior to mission launch in all relevant satellite locations and in real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

  3. Theory and modelling of the magnetic field measurement in LISA PathFinder

    International Nuclear Information System (INIS)

    Diaz-Aguilo, M; Garcia-Berro, E; Lobo, A

    2010-01-01

    The magnetic diagnostics subsystem of the LISA Technology Package (LTP) on board the LISA PathFinder (LPF) spacecraft includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at their respective positions. However, their readouts do not provide a direct measurement of the magnetic field at the positions of the test masses, and hence an interpolation method must be designed and implemented to obtain the values of the magnetic field at these positions. However, such an interpolation process faces serious difficulties. Indeed, the size of the interpolation region is excessive for a linear interpolation to be reliable while, on the other hand, the number of magnetometer channels do not provide sufficient data to go beyond the linear approximation. We describe an alternative method to address this issue, by means of neural network algorithms. The key point in this approach is the ability of neural networks to learn from suitable training data representing the behaviour of the magnetic field. Despite the relatively large distance between the test masses and the magnetometers, and the insufficient number of data channels, we find that our artificial neural network algorithm is able to reduce the estimation errors of the field and gradient down to levels below 10%, a quite satisfactory result. Learning efficiency can be best improved by making use of data obtained in on-ground measurements prior to mission launch in all relevant satellite locations and in real operation conditions. Reliable information on that appears to be essential for a meaningful assessment of magnetic noise in the LTP.

  4. Metal-amplified Density Assays, (MADAs), including a Density-Linked Immunosorbent Assay (DeLISA).

    Science.gov (United States)

    Subramaniam, Anand Bala; Gonidec, Mathieu; Shapiro, Nathan D; Kresse, Kayleigh M; Whitesides, George M

    2015-02-21

    This paper reports the development of Metal-amplified Density Assays, or MADAs - a method of conducting quantitative or multiplexed assays, including immunoassays, by using Magnetic Levitation (MagLev) to measure metal-amplified changes in the density of beads labeled with biomolecules. The binding of target analytes (i.e. proteins, antibodies, antigens) to complementary ligands immobilized on the surface of the beads, followed by a chemical amplification of the binding in a form that results in a change in the density of the beads (achieved by using gold nanoparticle-labeled biomolecules, and electroless deposition of gold or silver), translates analyte binding events into changes in density measureable using MagLev. A minimal model based on diffusion-limited growth of hemispherical nuclei on a surface reproduces the dynamics of the assay. A MADA - when performed with antigens and antibodies - is called a Density-Linked Immunosorbent Assay, or DeLISA. Two immunoassays provided a proof of principle: a competitive quantification of the concentration of neomycin in whole milk, and a multiplexed detection of antibodies against Hepatitis C virus NS3 protein and syphilis T. pallidum p47 protein in serum. MADAs, including DeLISAs, require, besides the requisite biomolecules and amplification reagents, minimal specialized equipment (two permanent magnets, a ruler or a capillary with calibrated length markings) and no electrical power to obtain a quantitative readout of analyte concentration. With further development, the method may be useful in resource-limited or point-of-care settings.

  5. The low emittance 2.5 GeV synchrotron light source LISA

    International Nuclear Information System (INIS)

    Einfeld, D.; Hormes, J.; Husmann, D.

    1992-01-01

    LISA, a Light source for Industrial and Scientific Applications, has been proposed. Due to the intention to use the source above all for the LIGA (Lithographie, Galvanik, Abformtechnik) method to produce micromechanical structures, the critical wavelength of the synchrotron radiation spectrum is foreseen to be 0.2 nm. Therefore, the electron energy and the field strength of the ring dipoles have been chosen to be 2.5 GeV and 1.5 T, respectively. It is proposed to make use of a modified 'quadrupole ben achromat' (QBA) lattice. The novel feature of this lattice is the application of two types of bending magnets of different lengths, i.e. different bending angels. (author) 9 refs.; 6 figs.; 1 tab

  6. Strong lensing of gravitational waves as seen by LISA.

    Science.gov (United States)

    Sereno, M; Sesana, A; Bleuler, A; Jetzer, Ph; Volonteri, M; Begelman, M C

    2010-12-17

    We discuss strong gravitational lensing of gravitational waves from the merging of massive black hole binaries in the context of the LISA mission. Detection of multiple events would provide invaluable information on competing theories of gravity, evolution and formation of structures and, possibly, constraints on H0 and other cosmological parameters. Most of the optical depth for lensing is provided by intervening massive galactic halos, for which wave optics effects are negligible. Probabilities to observe multiple events are sizable for a broad range of formation histories. For the most optimistic models, up to ≲ 4 multiple events with a signal to noise ratio ≳ 8 are expected in a 5-year mission. Chances are significant even for conservative models with either light (≲ 60%) or heavy (≲ 40%) seeds. Because of lensing amplification, some intrinsically too faint signals are brought over threshold (≲ 2 per year).

  7. After-dinner speech: the path of LISA to become ‘L3’

    Science.gov (United States)

    Huber, M. C. E.

    2017-05-01

    We describe the state of fundamental-physics experiments in space in the mid 1980s on both sides of the Atlantic, and then follow the development of this field within ESA’s Scientific Programme. The special case of LISA — a fundamental physics experiment in space also supported by astronomers, and now, following the ground-based detection of gravitational waves, the means to extend the observable spectrum of such waves towards lower frequencies and long-lasting signals — is then followed in its rise to become the ‘Large Project L3’ of ESA.

  8. Metaphors Expressing Emotions in Lisa Kleypas’s Rainshadow Road Novel

    Directory of Open Access Journals (Sweden)

    Novi Liana Ko

    2014-05-01

    Full Text Available Metaphors have been always interesting to explore since they are able to represent many things, one of which is feelings. Article examined the metaphorical sentences which expressed emotions found in Lisa Kleypas’s the Rainshadow Road. Library research was conducted to find the kinds of emotions which were expressed by the metaphorical sentences. It was also done to figure out what the metaphors refered to. Another objective was to reveal the most dominant emotion which appeared through the metaphors expressed in the novel. The analysis used metaphor theory to compare the dictionary meaning and the metaphorical one. The result shows that there are various emotions which are expressed through the metaphorical sentences. Happiness is found as the most dominant emotion which appears in the novel.

  9. Simple Enough--Even for Web Virgins: Lisa Mitten's Access to Native American Web Sites. Web Site Review Essay.

    Science.gov (United States)

    Belgarde, Mary Jiron

    1998-01-01

    A mixed-blood Mohawk urban Indian and university librarian, Lisa Mitten provides access to Web sites with solid information about American Indians. Links are provided to 10 categories--Native nations, Native organizations, Indian education, Native media, powwows and festivals, Indian music, Native arts, Native businesses, and Indian-oriented home…

  10. Compact laser interferometer for translation and tilt measurement as optical readout for the LISA inertial sensor

    Science.gov (United States)

    Schuldt, Thilo; Gohlke, Martin; Weise, Dennis; Johann, Ulrich; Peters, Achim; Braxmaier, Claus

    2007-10-01

    The space mission LISA (Laser Interferometer Space Antenna) aims at detecting gravitational waves in the frequency range 30 μ Hz to 1Hz. Free flying proof masses inside the satellites act as inertial sensors and represent the end mirrors of the interferometer. In the current baseline design, LISA utilizes an optical readout of the position and tilt of the proof mass with respect to the satellite housing. This readout must have ~ 5pm/√Hz sensitivity for the translation measurement (for frequencies above 2.8mHz with an ƒ -2 relaxation down to 30 μHz) and ~ 10 nrad/√Hz sensitivity for the tilt measurement (for frequencies above 0.1mHz with an ƒ -1 relaxation down to 30 μHz). The University of Applied Sciences Konstanz (HTWG) - in collaboration with Astrium GmbH, Friedrichshafen, and the Humboldt-University Berlin - therefore develops a highly symmetric heterodyne interferometer implementing differential wavefront sensing for the tilt measurement. We realized a mechanically highly stable and compact setup. In a second, improved setup we measured initial noise levels below 5 pm/√Hz and 10 nrad/√Hz, respectively, for frequencies above 10mHz.

  11. Playing Harry Potter: Essays and interviews on fandom and performance, edited by Lisa S. Brenner [book review

    Directory of Open Access Journals (Sweden)

    Abigail De Kosnik

    2016-09-01

    Full Text Available Review of Lisa S. Brenner, editor. Playing Harry Potter: Essays and interviews on fandom and performance. Jefferson, NC: McFarland, 2015, paperback, $29.95 (238p ISBN 978-0-7864-9657-0, e-book $14.43 (5374 KB ISBN 978-1-4766-2136-4, ASIN B012E9G0R6.

  12. Elimination of vibrio cholerae in lisa fillets (Mugil cephalus) by gamma radiation

    International Nuclear Information System (INIS)

    Torres, Z.

    1999-03-01

    The elimination of Vibrio cholerae 01 biotype El Tor (1,87 8 cuf/g) in fresh lisa fillets (Mugil cephalus) with radiation doses of 0 and 0,5 kGy was investigated. Furthermore, in order to evaluate physical, chemical and sensory changes, doses of 1,2,3 and 4 kGy were applied to non inoculated fillets of lisa. Finally, D 10 for Vibrio cholerae was determined in a saline suspension (5,2x10 8 cfu/ml) based on the Most Probable Number (MPN) method and radiation doses of 0,5, 0,75, 1,0, 1,25 and 1,5 kGy. D value found in a 1,87 8 cfu/g concentration of fillet was 0,13 kGy. Humidity, protein, fat and ash contents were not affected significantly and remained around 73 to 75,5, 3,8 to 4,2 and 1% respectively. Control samples showed a 'drip' variation ranging between 0,82 and 0,88% and a N-BVT variation between 1,77 and 1,56, 0,89 and 1,99, 2,13 and 2,47, 1,86 and 2,10%, and a N-BVT variation between 17,79 and 30,16, 16,37 and 26,88 16,33 and 25,12, 15,31 and 33,54 mg N/100 g, respectively. The highest life span for the appearance characteristic was obtained by control samples (23 days) and the lowest by samples radiated at 3 and 4 kGy (28 days). 4 kGy dose resulted in organoleptic changes perceived by panelists during tasting of cooked fish. D 10 found in a saline suspension was 0,13 kGy

  13. Time-delay interferometric ranging for space-borne gravitational-wave detectors

    International Nuclear Information System (INIS)

    Tinto, Massimo; Vallisneri, Michele; Armstrong, J.W.

    2005-01-01

    Space-borne interferometric gravitational-wave detectors, sensitive in the low-frequency (mHz) band, will fly in the next decade. In these detectors, the spacecraft-to-spacecraft light-travel times will necessarily be unequal and time varying, and (because of aberration) will have different values on up- and down-links. In such unequal-armlength interferometers, laser-phase noise will be canceled by taking linear combinations of the laser-phase observables measured between pairs of spacecraft, appropriately time shifted by the light propagation times along the corresponding arms. This procedure, known as time-delay interferometry (TDI), requires an accurate knowledge of the light-time delays as functions of time. Here we propose a high-accuracy technique to estimate these time delays, and we study its use in the context of the Laser Interferometer Space Antenna (LISA) mission. We refer to this ranging technique, which relies on the TDI combinations themselves, as time-delay interferometric ranging (TDIR). For every TDI combination, we show that, by minimizing the rms power in that combination (averaged over integration times ∼10 4 s) with respect to the time-delay parameters, we obtain estimates of the time delays accurate enough to cancel laser noise to a level well below the secondary noises. Thus TDIR allows the implementation of TDI without the use of dedicated interspacecraft ranging systems, with a potential simplification of the LISA design. In this paper we define the TDIR procedure formally, and we characterize its expected performance via simulations with the Synthetic LISA software package

  14. Massive Black Hole Mergers: Can we see what LISA will hear?

    Science.gov (United States)

    Centrella, Joan

    2009-01-01

    Coalescing massive black hole binaries are formed when galaxies merge. The final stages of this coalescence produce strong gravitational wave signals that can be detected by the space-borne LISA. When the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Modeling such electromagnetic counterparts requires evolving the behavior of both gas and fields in the strong-field regions around the black holes. We have taken a first step towards this problem by mapping the flow of pressureless matter in the dynamic, 3-D general relativistic spacetime around the merging black holes. We report on the results of these initial simulations and discuss their likely importance for future hydrodynamical simulations.

  15. eLISA Telescope In-field Pointing and Scattered Light Study

    Science.gov (United States)

    Livas, J.; Sankar, S.; West, G.; Seals, L.; Howard, J.; Fitzsimons, E.

    2017-05-01

    The orbital motion of the three spacecraft that make up the eLISA Observatory constellation causes long-arm line of sight variations of approximately ± one degree over the course of a year. The baseline solution is to package the telescope, the optical bench, and the gravitational reference sensor (GRS) into an optical assembly at each end of the measurement arm, and then to articulate the assembly. An optical phase reference is exchanged between the moving optical benches with a single mode optical fiber (“backlink” fiber). An alternative solution, referred to as in-field pointing, embeds a steering mirror into the optical design, fixing the optical benches and eliminating the backlink fiber, but requiring the additional complication of a two-stage optical design for the telescope. We examine the impact of an in-field pointing design on the scattered light performance.

  16. Interferometry for the LISA technology package (LTP) aboard SMART-2

    International Nuclear Information System (INIS)

    Heinzel, G; Braxmaier, C; Schilling, R; Ruediger, A; Robertson, D; Plate, M te; Wand, V; Arai, K; Johann, U; Danzmann, K

    2003-01-01

    The interferometer of the LISA technology package (LTP) on SMART-2 is needed to verify the performance of the gravitational sensors by monitoring the distance between two test masses with a noise level of 10 pm Hz -1/2 between 3 mHz and 30 mHz. It must continuously track the motion of the test mass distance while that distance changes by many μm with a speed of up to 20 μm s -1 , without losing track of the sign of the motion and without exerting any influence on the test masses that might lead to a motion above that level. As a result of a detailed comparison study, a heterodyne Mach-Zehnder interferometer was selected as the baseline for the SMART-2 mission. Its design and expected performance are described in this paper

  17. Radiation pressure calibration and test mass reflectivities for LISA Pathfinder

    International Nuclear Information System (INIS)

    Korsakova, Natalia; Kaune, Brigitte

    2017-01-01

    This paper describes a series of experiments which were carried out during the main operations of LISA Pathfinder. These experiments were performed by modulating the power of the measurement and reference beams. In one series of experiments the beams were sequentially switched on and off. In the other series of experiments the powers of the beams were modulated within 0.1% and 1% of the constant power. These experiments use recordings of the total power measured on the photodiodes to infer the properties of the Optical Metrology System (OMS), such as reflectivities of the test masses and change of the photodiode efficiencies with time. In the first case the powers are back propagated from the different photodiodes to the same place on the optical bench to express the unknown quantities in the measurement with the complimentary photodiode measurements. They are combined in the way that the only unknown left is the test mass reflectivities. The second experiment compared two estimates of the force applied to the test masses due to the radiation pressure that appears because of the beam modulations. One estimate of the force is inferred from the measurements of the powers on the photodiodes and propagation of this measurement to the test masses. The other estimation of the force is done by calculating it from the change in the main scientific output of the instrument – differential displacement of the two test masses. (paper)

  18. Radiation pressure calibration and test mass reflectivities for LISA Pathfinder

    Science.gov (United States)

    Korsakova, Natalia; Kaune, Brigitte; LPF Collaboration

    2017-05-01

    This paper describes a series of experiments which were carried out during the main operations of LISA Pathfinder. These experiments were performed by modulating the power of the measurement and reference beams. In one series of experiments the beams were sequentially switched on and off. In the other series of experiments the powers of the beams were modulated within 0.1% and 1% of the constant power. These experiments use recordings of the total power measured on the photodiodes to infer the properties of the Optical Metrology System (OMS), such as reflectivities of the test masses and change of the photodiode efficiencies with time. In the first case the powers are back propagated from the different photodiodes to the same place on the optical bench to express the unknown quantities in the measurement with the complimentary photodiode measurements. They are combined in the way that the only unknown left is the test mass reflectivities. The second experiment compared two estimates of the force applied to the test masses due to the radiation pressure that appears because of the beam modulations. One estimate of the force is inferred from the measurements of the powers on the photodiodes and propagation of this measurement to the test masses. The other estimation of the force is done by calculating it from the change in the main scientific output of the instrument - differential displacement of the two test masses.

  19. Novel Payload Architectures for LISA

    Science.gov (United States)

    Johann, Ulrich A.; Gath, Peter F.; Holota, Wolfgang; Schulte, Hans Reiner; Weise, Dennis

    2006-11-01

    As part of the current LISA Mission Formulation Study, and based on prior internal investigations, Astrium Germany has defined and preliminary assessed novel payload architectures, potentially reducing overall complexity and improving budgets and costs. A promising concept is characterized by a single active inertial sensor attached to a single optical bench and serving both adjacent interferometer arms via two rigidly connected off-axis telescopes. The in-plane triangular constellation ``breathing angle'' compensation is accomplished by common telescope in-field of view pointing actuation of the transmit/received beams line of sight. A dedicated actuation mechanism located on the optical bench is required in addition to the on bench actuators for differential pointing of the transmit and receive direction perpendicular to the constellation plane. Both actuators operate in a sinusoidal yearly period. A technical challenge is the actuation mechanism pointing jitter and the monitoring and calibration of the laser phase walk which occurs while changing the optical path inside the optical assembly during re-pointing. Calibration or monitoring of instrument internal phase effects e.g. by a laser metrology truss derived from the existing interferometry is required. The architecture exploits in full the two-step interferometry (strap down) concept, separating functionally inter spacecraft and intra-spacecraft interferometry (reference mass laser metrology degrees of freedom sensing). The single test mass is maintained as cubic, but in free-fall in the lateral degrees of freedom within the constellation plane. Also the option of a completely free spherical test mass with full laser interferometer readout has been conceptually investigated. The spherical test mass would rotate slowly, and would be allowed to tumble. Imperfections in roundness and density would be calibrated from differential wave front sensing in a tetrahedral arrangement, supported by added attitude

  20. Picometer stable scan mechanism for gravitational wave detection in space: LISA PAAM

    Science.gov (United States)

    Pijnenburg, J. A. C. M.; Rijnveld, N.

    2017-11-01

    Detection and observation of gravitational waves requires extreme stability in the frequency range 0.03 mHz to 1 Hz. The Laser Interferometer Space Antenna (LISA) mission will attain this by creating a giant interferometer in space, based on free floating proof masses in three spacecrafts. Due to orbit evolution and time delay in the interferometer arms, the direction of transmitted light changes. To solve this problem, a picometer stable Point-Ahead Angle Mechanism (PAAM) was designed, realized and successfully tested. The PAAM concept is based on a rotatable mirror. The critical requirements are the contribution to the optical path length (less than 1.4 pm / rt Hz) and the angular jitter (less than 8 nrad / rt Hz). Extreme dimensional stability is achieved by manufacturing a monolithical Haberland hinge mechanism out of Ti6Al4V, through high precision wire erosion. Extreme thermal stability is realized by placing the thermal center on the surface of the mirror. Because of piezo actuator noise and leakage, the PAAM has to be controlled in closed-loop. To meet the requirements in the low frequencies, an active target capacitance-to-digital converter is used. Interferometric measurements with a triangular resonant cavity in vacuum proved that the PAAM meets the requirements.

  1. Coupling of relative intensity noise and pathlength noise to the length measurement in the optical metrology system of LISA Pathfinder

    Science.gov (United States)

    Wittchen, Andreas; the LPF Collaboration

    2017-05-01

    LISA Pathfinder is a technology demonstration mission for the space-based gravitational wave observatory, LISA. It demonstrated that the performance requirements for the interferometric measurement of two test masses in free fall can be met. An important part of the data analysis is to identify the limiting noise sources. [1] This measurement is performed with heterodyne interferometry. The performance of this optical metrology system (OMS) at high frequencies is limited by sensing noise. One such noise source is Relative Intensity Noise (RIN). RIN is a property of the laser, and the photodiode current generated by the interferometer signal contains frequency dependant RIN. From this electric signal the phasemeter calculates the phase change and laser power, and the coupling of RIN into the measurement signal depends on the noise frequency. RIN at DC, at the heterodyne frequency and at two times the heterodyne frequency couples into the phase. Another important noise at high frequencies is path length noise. To reduce the impact this noise is suppressed with a control loop. Path length noise not suppressed will couple directly into the length measurement. The subtraction techniques of both noise sources depend on the phase difference between the reference signal and the measurement signal, and thus on the test mass position. During normal operations we position the test mass at the interferometric zero, which is optimal for noise subtraction purposes. This paper will show results from an in-flight experiment where the test mass position was changed to make the position dependant noise visible.

  2. Time valis aasta vähim kajastatud uudiseks Somaalia kodusõja / Evelyn Kaldoja

    Index Scriptorium Estoniae

    Kaldoja, Evelyn, 1980-

    2007-01-01

    Ilmunud ka: Postimees : na russkom jazõke, 20. dets. 2007, lk. 6. Ajakiri Time nimetas aasta inimeseks Venemaa presidendi Vladimir Putini. Lisa: Väljavõtteid ajakirja Time 2007. aasta edetabelite tippudest; Aasta tsitaadid

  3. Testing and Characterization of a Prototype Telescope for the Evolved Laser Interferometer Space Antenna (eLISA)

    Science.gov (United States)

    Sankar, S.; Livas, J.

    2016-01-01

    We describe our efforts to fabricate, test and characterize a prototype telescope for the eLISA mission. Much of our work has centered on the modeling and measurement of scattered light performance. This work also builds on a previous demonstration of a high dimensional stability metering structure using particular choices of materials and interfaces. We will discuss ongoing plans to merge these two separate demonstrations into a single telescope design demonstrating both stray light and dimensional stability requirements simultaneously.

  4. Parasites and hepatic histopathological lesions in lisa (Mugil incilis from Totumo mash, North of Colombia

    Directory of Open Access Journals (Sweden)

    Jesús Olivero V.

    2013-03-01

    Full Text Available Objective. To assess the levels of parasitism by nematodes and trematodes, as well as the hepatic histopathological alterations present in Mugil incilis (Lisa from Totumo marsh, North of Colombia. Materials and methods. Between July 2004 and June 2005, 500 fish were collected at Totumo Marsh (75°16’W and 10°44´N, North of Colombia. Morphometric and parasitic parameters were determined for each specimen, and the hepatic histopathological status of the liver was assessed by analyzing liver slides stained with hematoxylin and eosin. Results. Nematode larvae isolated from Mugil incilis corresponded to Contracaecum spp. Parasite prevalence was 60.49%. Parasitic mean abundance and mean intensity were 4.8±1.05 and 7.02±1.49, nematodes per fish, respectively. The correlation between nematode mean abundance and fish length was significant and positive (r=0.525, p<0.0001, but negative for condition factor (r=-0.109, p=0.014. Hepatic histopathological analysis revealed the presence of encapsulated trematode larvae as the main finding. However, the presence of inflammation, granulomas, steatosis and necrosis, were also registered as secondary alterations. Conclusions. Lisas collected at Totumo Marsh are parasitized with nematodes and trematodes. These fish have different histopathological lesions in the liver tissue, being the most important the presence of trematode encapsulated cyst that generate inflammatory reactions, and negatively correlate with morphometric markers of fish health.

  5. Detecting white dwarf binaries in Mock LISA Data Challenge 3

    International Nuclear Information System (INIS)

    Blaut, A; Krolak, A; Babak, S

    2009-01-01

    We present a strategy for detecting gravitational wave signals from the Galactic white dwarf binaries in the Mock LISA Data Challenge 3 (MLDC3) and estimate their parameters. Our method is based on the matched filtering in the form of the F-statistic. We perform the search on three-dimensional space (sky coordinate and frequency of gravitational wave) below 3 mHz and include the fourth parameter (frequency derivative) at high frequencies. A template bank is used to search for the strongest signal in the data, then we remove it and repeat the search until we do not have signals in the data above a preselected threshold. For the template bank, we construct an optimal grid that realizes the best lattice covering with a constraint such that the nodes of the grid coincide with the Fourier frequencies. This enables the use of the fast Fourier transform algorithm to calculate the F-statistic.

  6. Actuation stability test of the LISA pathfinder inertial sensor front-end electronics

    Science.gov (United States)

    Mance, Davor; Gan, Li; Weber, Bill; Weber, Franz; Zweifel, Peter

    In order to limit the residual stray forces on the inertial sensor test mass in LISA pathfinder, √ it is required that the fluctuation of the test mass actuation voltage is within 2ppm/ Hz. The actuation voltage stability test on the flight hardware of the inertial sensor front-end electronics (IS FEE) is presented in this paper. This test is completed during the inertial sensor integration at EADS Astrium Friedrichshafen, Germany. The standard measurement method using voltmeter is not sufficient for verification, since the instrument low frequency √ fluctuation is higher than the 2ppm/ Hz requirement. In this test, by using the differential measurement method and the lock-in amplifier, the actuation stability performance is verified and the quality of the IS FEE hardware is confirmed by the test results.

  7. LISA. A code for safety assessment in nuclear waste disposals program description and user guide

    International Nuclear Information System (INIS)

    Saltelli, A.; Bertozzi, G.; Stanners, D.A.

    1984-01-01

    The code LISA (Long term Isolation Safety Assessment), developed at the Joint Research Centre, Ispra is a useful tool in the analysis of the hazard due to the disposal of nuclear waste in geological formations. The risk linked to preestablished release scenarios is assessed by the code in terms of dose rate to a maximum exposed individual. The various submodels in the code simulate the system of barriers -both natural and man made- which are interposed between the contaminants and man. After a description of the code features a guide for the user is supplied and then a test case is presented

  8. Analog phase lock between two lasers at LISA power levels

    International Nuclear Information System (INIS)

    Diekmann, Christian; Steier, Frank; Sheard, Benjamin; Heinzel, Gerhard; Danzmann, Karsten

    2009-01-01

    This paper presents the implementation of an analog optical phase-locked-loop with an offset frequency of about 20MHz between two lasers, where the detected light powers were of the order of 31 pW and 200 μW. The goal of this setup was the design and characterization of a photodiode transimpedance amplifier for application in LISA. By application of a transimpedance amplifier designed to have low noise and low power consumption, the phase noise between the two lasers was a factor of two above the shot noise limit down to 60mHz. The achievable phase sensitivity depends ultimately on the available power of the highly attenuated master laser and on the input current noise of the transimpedance amplifier of the photodetector. The limiting noise source below 60mHz was the analog phase measurement system that was used in this experiment. A digital phase measurement system that is currently under development at the AEI will be used in the near future. Its application should improve the sensitivity.

  9. Analog phase lock between two lasers at LISA power levels

    Energy Technology Data Exchange (ETDEWEB)

    Diekmann, Christian; Steier, Frank; Sheard, Benjamin; Heinzel, Gerhard; Danzmann, Karsten, E-mail: Christian.Diekmann@aei.mpg.d [Max-Planck-Institute for Gravitational Physics, Callinstr. 38, D-30167 Hannover (Germany)

    2009-03-01

    This paper presents the implementation of an analog optical phase-locked-loop with an offset frequency of about 20MHz between two lasers, where the detected light powers were of the order of 31 pW and 200 muW. The goal of this setup was the design and characterization of a photodiode transimpedance amplifier for application in LISA. By application of a transimpedance amplifier designed to have low noise and low power consumption, the phase noise between the two lasers was a factor of two above the shot noise limit down to 60mHz. The achievable phase sensitivity depends ultimately on the available power of the highly attenuated master laser and on the input current noise of the transimpedance amplifier of the photodetector. The limiting noise source below 60mHz was the analog phase measurement system that was used in this experiment. A digital phase measurement system that is currently under development at the AEI will be used in the near future. Its application should improve the sensitivity.

  10. Planning for chemical disasters at Point Lisas, Trinidad and Tobago

    International Nuclear Information System (INIS)

    Mathur, M.N.

    1995-01-01

    No major chemical disaster has taken place so far in Trinidad and Tobago. Even so, in view of the numerous hazards that the various chemical handling plants deal with at Point Lisas, the country has to be prepared to deal with chemical disasters. The country's emergency preparedness plan for chemical disasters aims to localize the emergency, if possible, eliminate it and minimize the effects of the accident on people and property. The hazards of ammonia, hydrogen, chlorine, hydrocarbons and methanol release can have devastating effects on the workers and the residents in the vicinity of the plants. The Emergency Plan identifies an Emergency Co-ordinating Officer who would take command of the off-site activities and coordinate the activities of Works Management, Local Authority, Police, Fire Services, Defence Force, Health Authority and Factory Inspectorate. Resources of fire fighting, medical treatment, telecommunications, waste management and public education have to be enhanced immediately. In the long term a new fire station and a new county hospital have to be built, some housing settlements have to be phased out and non-essential staff relocated

  11. Bell's palsy: the answer to the riddle of Leonardo da Vinci's 'Mona Lisa'.

    Science.gov (United States)

    Maloney, W J

    2011-05-01

    The smile of the famed portrait 'The Mona Lisa' has perplexed both art historians and researchers for the past 500 years. There has been a multitude of theories expounded to explain the nature of the model's enigmatic smile. The origin of the model's wry smile can be demonstrated through a careful analysis of both documented facts concerning the portrait--some gathered only recently through the use of modern technology--and a knowledge of the clinical presentation of Bell's palsy. Bell's palsy is more prevalent in women who are either pregnant or who have recently given birth. This paper postulates that the smile of the portrait's model was due to Leonardo da Vinci's anatomically precise representation of a new mother affected by Bell's palsy subsequent to her recent pregnancy.

  12. Análise Bibliométrica da produção científica em gestão da informação na base de dados lisa / Bibliometrics analysis of scientific production in management information in the lisa database

    OpenAIRE

    Luiza da Silva Kleinubing

    2010-01-01

    Descreve e analisa as principais características bibliométricas das publicações relacionadas à área de gestão da informação da base de dados Lisa, uma das bases com maior visibilidade no campo da Biblioteconomia e Ciência da Informação. Foram analisados 138 artigos. A metodologia de pesquisa combina métodos bibliométricos e softwares, a característica da pesquisa é quantitativa, pois enumera e mede, e qualitativa, pois compreende e explica. Conclui-se sinalizando que os métodos bibliométricos...

  13. Inference on white dwarf binary systems using the first round Mock LISA Data Challenges data sets

    International Nuclear Information System (INIS)

    Stroeer, Alexander; Veitch, John; Roever, Christian; Bloomer, Ed; Clark, James; Christensen, Nelson; Hendry, Martin; Messenger, Chris; Meyer, Renate; Pitkin, Matthew; Toher, Jennifer; Umstaetter, Richard; Vecchio, Alberto; Woan, Graham

    2007-01-01

    We report on the analysis of selected single source data sets from the first round of the mock LISA data challenges (MLDC) for white dwarf binaries. We implemented an end-to-end pipeline consisting of a grid-based coherent pre-processing unit for signal detection and an automatic Markov Chain Monte Carlo (MCMC) post-processing unit for signal evaluation. We demonstrate that signal detection with our coherent approach is secure and accurate, and is increased in accuracy and supplemented with additional information on the signal parameters by our Markov Chain Monte Carlo approach. We also demonstrate that the Markov Chain Monte Carlo routine is additionally able to determine accurately the noise level in the frequency window of interest

  14. A high sensitivity heterodyne interferometer as a possible optical readout for the LISA gravitational reference sensor and its application to technology verification

    Energy Technology Data Exchange (ETDEWEB)

    Gohlke, Martin; Weise, Dennis; Johann, Ulrich; Braxmaier, Claus [EADS Astrium, Claude-Dornier-Strasse, 88039 Friedrichshafen (Germany); Schuldt, Thilo; Peters, Achim, E-mail: martin.gohlke@astrium.eads.ne [Humboldt-Universitaet zu Berlin, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2009-03-01

    The space-based gravitational wave detector LISA (Laser Interferometer Space Antenna) utilizes a high performance position sensor in order to measure the translation and tilt of the free flying proof mass with respect to the optical bench. Depending on the LISA optical bench design, this position sensor must have up to pm/sq rootHz sensitivity for the translation measurement and up to nrad/sq rootHz sensitivity for the tilt measurement. We developed a heterodyne interferometer, combined with differential wavefront sensing, for the tilt measurement. The interferometer design exhibits maximum symmetry where measurement and reference arm have the same frequency and polarization and the same optical path-lengths. The interferometer can be set up free of polarizing optical components preventing possible problems with thermal dependencies not suitable for the space environment. We developed a mechanically highly stable and compact setup which is located in a vacuum chamber. We measured initial noise levels below 10 pm/sq rootHz (longitudinal measurement) for frequencies above 10 mHz and below 20 nrad/sq rootHz (tilt measurement) for frequencies above 1 mHz. This setup can also be used for other applications, for example the measurement of the coefficient of thermal expansion (CTE) of structural materials, such as carbon fiber reinforced plastic (CFRP).

  15. Quantitative analysis of LISA pathfinder test-mass noise

    International Nuclear Information System (INIS)

    Ferraioli, Luigi; Congedo, Giuseppe; Hueller, Mauro; Vitale, Stefano; Hewitson, Martin; Nofrarias, Miquel; Armano, Michele

    2011-01-01

    LISA Pathfinder (LPF) is a mission aiming to test the critical technology for the forthcoming space-based gravitational-wave detectors. The main scientific objective of the LPF mission is to demonstrate test masses free falling with residual accelerations below 3x10 -14 m s -2 /√(Hz) at 1 mHz. Reaching such an ambitious target will require a significant amount of system optimization and characterization, which will in turn require accurate and quantitative noise analysis procedures. In this paper, we discuss two main problems associated with the analysis of the data from LPF: i) excess noise detection and ii) noise parameter identification. The mission is focused on the low-frequency region ([0.1, 10] mHz) of the available signal spectrum. In such a region, the signal is dominated by the force noise acting on test masses. At the same time, the mission duration is limited to 90 days and typical data segments will be 24 hours in length. Considering those constraints, noise analysis is expected to deal with a limited amount of non-Gaussian data, since the spectrum statistics will be far from Gaussian and the lowest available frequency is limited by the data length. In this paper, we analyze the details of the expected statistics for spectral data and develop two suitable excess noise estimators. One is based on the statistical properties of the integrated spectrum, the other is based on the Kolmogorov-Smirnov test. The sensitivity of the estimators is discussed theoretically for independent data, then the algorithms are tested on LPF synthetic data. The test on realistic LPF data allows the effect of spectral data correlations on the efficiency of the different noise excess estimators to be highlighted. It also reveals the versatility of the Kolmogorov-Smirnov approach, which can be adapted to provide reasonable results on correlated data from a modified version of the standard equations for the inversion of the test statistic. Closely related to excess noise

  16. Avaliação do desempenho visual da lente intraocular difrativa multifocal - Zeiss AT Lisa 809 MTM

    Directory of Open Access Journals (Sweden)

    Lucas Monferrari Monteiro Vianna

    2014-04-01

    Full Text Available Objetivo: Avaliar a função visual dos pacientes com implante bilateral da LIO multifocal difrativa AT-Lisa 809 MTM por meio dos exames de acuidade visual com e sem correção óptica, curva de sensibilidade ao contraste, curva de desfoco e questionário de qualidade de função visual (VQF39. Métodos: Estudo clínico, prospectivo e de intervenção, que avaliou os resultados de 20 olhos de 10 pacientes, submetidos à facoemulsificação e implante de LIO, entre fevereiro e junho de 2012. Resultados: A ametropia residual média pós-operatória foi de 0,05 ± 0,42 (-0,75 a +1,25 D dioptrias esféricas e -0,30 ± 0,42 (0 a -1,25 D dioptrias cilíndricas. Na curva de desenfoque mono e binocular, a melhor acuidade visual média obtida com 0.00 D de desenfoque (AV de longe. O segundo pico foi obtido com desenfoque de -3,00 D, o que equivale à visão de perto a 33 cm. Entre esses picos, observamos uma perda de desempenho visual, com desenfoque de -2,00 D, que equivale a visão intermediária a 50 cm. A sensibilidade ao contraste foi similar aos relatados na literatura com este tipo de LIO, tanto com quanto sem ofuscamento, e é mostrada em gráficos. O questionário de função visual (VFQ-39 teve valor médio de 91,91 +- 6,82. Conclusão: A LIO multifocal difrativa AT-Lisa 809MTM (Carl Zeiss Meditec Company - Alemanha apresentou resultados condizentes com a literatura quando avaliada pelos exames de acuidade visual com e sem correção óptica, sensibilidade ao contraste, curva de desfoco e questionário de qualidade de função visual (VQF 39.

  17. Diseño de un plan de marketing para el producto lisa college desarrollado por la microempresa browse Ecuador, ubicada en la ciudad de Quito.

    OpenAIRE

    Coello Duque, Giomar Evelyn

    2013-01-01

    The present work aims to make a marketing plan for the product developed by Lisa College microenterprise Browse Ecuador Cia. Ltd. and it will be a guide for other micros companies wishing to conduct similar research. First, we review general information about the company under study in order to identify problems, research objectives and delimitation of the research area. With this knowledge provides the theoretical and conceptual framework underpinning this research. The ...

  18. On-ground testing of the role of adhesion in the LISA-Pathfinder test mass injection phase

    Science.gov (United States)

    Bortoluzzi, D.; Zanoni, C.; Conklin, J. W.

    2017-05-01

    Many space missions share the need to fly a free-falling body inside the spacecraft, as a reference for navigation and/or as a probe for the local gravitational field. When a mechanism is required to cage such an object during the launch phase, the need arises to release it to free-fall once the operational phase must be initiated in orbit. The criticality of this phase increases when the mechanical interfaces between the body and the mechanism are affected by adhesion and the actuation authority of the control system on the free-falling body is limited. Both conditions are realized in the LISA Pathfinder mission, which aims at injecting a gold-coated 2 kg cubic test mass into a nearly perfect geodesic trajectory to demonstrate the readiness of the developed technology for in-space gravity wave detection. The criticality of adhesion is widely recognized in space technology, because it can affect and jeopardize the functionality of mechanisms, when arising between moving parts. In the LISA Pathfinder case, metallic adhesion potentially plays a relevant role, mainly for two reasons. First, thanks to its properties (ductility, high surface energy) the gold coating on the proof mass easily produces cold weldings, especially in vacuum conditions. Second, the detachment of the proof mass from the releasing device occurs abruptly and a relevant influence of the separation velocity is expected on the strength of the welding. This can produce an excessive velocity of the proof mass at the retraction of the releasing device for the following capture and centring phase on behalf of the control system. A testing activity is performed to characterize the dynamic behaviour of the adhesive bonds between the proof mass and the releasing device, which can be used to predict their contribution on the residual velocity of the proof mass after in-flight release. The study of such a dynamic phenomenon sets some challenging requirements on the measurement technique, both on the

  19. Validation of a short, qualitative food frequency questionnaire in French adults participating in the MONA LISA-NUT study 2005-2007.

    Science.gov (United States)

    Giovannelli, Jonathan; Dallongeville, Jean; Wagner, Aline; Bongard, Vanina; Laillet, Brigitte; Marecaux, Nadine; Ruidavets, Jean Bernard; Haas, Bernadette; Ferrieres, Jean; Arveiler, Dominique; Simon, Chantal; Dauchet, Luc

    2014-04-01

    Food frequency questionnaires (FFQs) are often used to evaluate individuals' food intakes in epidemiologic studies because of their simplicity and low cost. To assess the validity of a short (24 items), qualitative FFQ used in the MONA LISA-NUT study. Cross-sectional study of a representative sample in three French counties. The sample included 2,630 participants aged 35 to 65 years from the MONA LISA-NUT study. Food consumption was measured with the FFQ and via food records for 3 consecutive days. Plasma fatty acids were measured from a subset of participants. The FFQ items' validity was assessed by calculating crude and deattenuated Pearson correlation coefficients between frequencies reported by the FFQ and average weights reported by the food records. Furthermore, the validity of some items of the FFQ measuring the consumption of fatty foods was assessed by calculating Pearson correlation coefficients between frequencies of consumption of these foods and dosages of the corresponding plasma fatty acids: fish and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), olive oil and oleic acid, margarine and elaidic acid, and dairy products and pentadecanoic and heptadecanoic acids. The mean of the deattenuated Pearson correlation coefficients for all items was 0.46, with values ranging from 0.22 (fried food) to 0.77 (breakfast cereal). The correlation coefficient was ≤ 0.4 for one third of the 24 items. Moderate correlations were found between fish and EPA/DHA (EPA: r=0.43, 95% CI 0.33 to 0.51; DHA: r=0.39, 95% CI 0.30 to 0.47), but not for other food items. One third of the 24 items in the short, qualitative FFQ evaluated here were not sufficiently valid. However, for the food groups most commonly studied in the literature, this FFQ had the same degree of validity as other questionnaires designed to classify subjects according to their level of intake. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  20. Measurement of the momentum transferred between contacting bodies during the LISA test-mass release phase—uncertainty estimation

    International Nuclear Information System (INIS)

    De Cecco, M; Bortoluzzi, D; Da Lio, M; Baglivo, L; Benedetti, M

    2009-01-01

    The requirements for the Laser Interferometer Space Antenna (LISA) test-mass (TM) release phase are analysed in view of the building up of a testing facility aimed at on-Earth qualification of the release mechanism. Accordingly, the release of the TM to free-fall must provide a linear momentum transferred to the TM not exceeding 10 −5 kg m s −1 . In order to test this requirement, a double pendulum system has been developed. The mock-ups of the TM and the release-dedicated plunger are brought into contact and then the latter is quickly retracted. During and after release, the TM motion is measured by a laser interferometer. The transferred momentum is estimated from the free oscillations following the plunger retraction by means of a Wiener–Kolmogorov optimal filter. This work is aimed at modelling the measurement chain, taking into account procedure, instruments, mechanisms and data elaboration in order to estimate the uncertainty associated with the transferred momentum measurement by means of Monte Carlo simulation

  1. Optical metrology alignment and impact on the measurement performance of the LISA Technology Package

    Energy Technology Data Exchange (ETDEWEB)

    Hirth, M; Fichter, W; Brandt, N; Gerardi, D [iFR, Universitaet Stuttgart, Pfaffenwaldring 7a, 70569 Stuttgart (Germany); Schleicher, A [Astrium GmbH, 88039 Friedrichshafen (Germany); Wanner, G, E-mail: marc.hirth@ifr.uni-stuttgart.d [Albert Einstein Institut, Callinstrasse 38, 30167 Hannover (Germany)

    2009-03-01

    Aside from LISA Pathfinder's top-level acceleration requirement, there is a stringent independent requirement for the accuracy of the optical metrology system. In case of a perfectly aligned metrology system (optical bench and test masses) it should rather be independent of residual displacement jitter due to control. However, this ideal case will not be achieved as mechanical tolerances and uncertainties lead to a direct impact of test mass and spacecraft displacement jitter on the optical measurement accuracy. In this paper, we present a strategy how to cover these effects for a systematic requirement breakdown. We use a simplified nonlinear geometrical model for the differential distance measurement of the test masses which is linearized and linked to the equations of motion for both the spacecraft and the two test masses. This leads from test mass relative displacement to a formulation in terms of applied force/torque and thus allows to distinguish the absolute motion of each of the three bodies. It further shows how motions in each degree of freedom couple linearly into the optical measurement via DC misalignments of the laser beam and the test masses. This finally allows for deriving requirements on the alignment accuracy of components and on permittable closed-loop acceleration noise. In the last part a budget for the expected measurement performance is compiled from simulations as no measurement data is available yet.

  2. Optical metrology alignment and impact on the measurement performance of the LISA Technology Package

    International Nuclear Information System (INIS)

    Hirth, M; Fichter, W; Brandt, N; Gerardi, D; Schleicher, A; Wanner, G

    2009-01-01

    Aside from LISA Pathfinder's top-level acceleration requirement, there is a stringent independent requirement for the accuracy of the optical metrology system. In case of a perfectly aligned metrology system (optical bench and test masses) it should rather be independent of residual displacement jitter due to control. However, this ideal case will not be achieved as mechanical tolerances and uncertainties lead to a direct impact of test mass and spacecraft displacement jitter on the optical measurement accuracy. In this paper, we present a strategy how to cover these effects for a systematic requirement breakdown. We use a simplified nonlinear geometrical model for the differential distance measurement of the test masses which is linearized and linked to the equations of motion for both the spacecraft and the two test masses. This leads from test mass relative displacement to a formulation in terms of applied force/torque and thus allows to distinguish the absolute motion of each of the three bodies. It further shows how motions in each degree of freedom couple linearly into the optical measurement via DC misalignments of the laser beam and the test masses. This finally allows for deriving requirements on the alignment accuracy of components and on permittable closed-loop acceleration noise. In the last part a budget for the expected measurement performance is compiled from simulations as no measurement data is available yet.

  3. Eventos adversos temporalmente asociados a VAMENGOC- BC®. Municipio La Lisa, 1998-1999

    Directory of Open Access Journals (Sweden)

    Iván Edelberto Cuevas

    2000-12-01

    Full Text Available Con el objetivo de describir la frecuencia de eventos temporalmente asociados a la vacuna cubana VAMENGOC- BC®, se realizó un estudio observacional de tipo descriptivo, cuyo universo estuvo constituido por los lactantes en las edades comprendidas de tres (3549 y cinco meses (3832 de edad de las áreas de salud del Municipio La Lisa en Ciudad de La Habana. Hubo un 3,21% de niños con eventos adversos, con una mayor frecuencia después de la primera dosis; sin diferencias apreciables por sexo. La clasificación fue de un 52% de tipo sistémico, locales un 19% y no solicitados un 29%. La mayor parte de los niños afectados fue en las primeras 72 horas posteriores a la vacunación, y desaparecieron antes de 72 horas desde su comienzo. Las manifestaciones más frecuentes fueron fiebre (predominó entre todos los eventos adversos con 1,53 casos por 100 vacunados; la induración (0,31 por 100 vacunados, eritema (0,30 por 100 vacunados y el dolor (0,136 por 100 vacunados en el sitio de administración de la vacuna; irritabilidad (0,244 por 100 vacunados y pérdida de apetito (0,311 por 100 vacunados. Los eventos no solicitados más frecuentes fueron la Enfermedad Respiratoria Aguda (0,637 por 100 vacunados, la Enfermedad Diarreica Aguda (0,311 por 100 vacunados y la Otitis Media (0,176 por 100 vacunados. Los eventos adversos serios fueron infrecuentes. No hubo fallecidos y todos los casos se recuperaron en menos de diez días, sin secuelas, discapacidades ni minusvalías

  4. Tumor misto de células musculares lisas e do estroma endometrial uterino: relato de caso Mixed endometrial stromal and smooth muscle tumor of the uterus: case report

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo Oliveira Brito

    2012-12-01

    Full Text Available Os tumores mistos de células musculares lisas e do estroma endometrial uterino, caracterizados pela presença de componentes de ambas as linhagens, coexistindo em proporções quase equivalentes, são neoplasmas raros. Possuem potencial biológico incerto e se comportam de acordo com o componente estromal. A imuno-histoquímica é uma grande aliada no diagnóstico microscópico, pois a clínica e os exames de imagem não ajudam a diferenciá-los de outras doenças uterinas. Descrevemos o caso de uma paciente cuja hipótese diagnóstica era de leiomioma uterino e que, após cirurgia, foi diagnosticada pelo estudo anatomopatológico como tumor misto de células musculares lisas e do estroma endometrial uterino.Mixed tumors of uterine smooth muscle and endometrial stromal cells, which are characterized by the presence of components from both cell lineages with similar proportions, are rare neoplasms. Their biological potential is uncertain, and they behave according to the stromal component. Immunohistochemistry is an important ally in microscopic diagnosis, because symptoms and imaging exams do not help in the differentiation from other uterine diseases. We describe a case of a patient who had been previously diagnosed with uterine leiomyoma, and after surgery, the anatomopathological study revealed a mixed tumor of uterine smooth muscle and endometrial stromal cells.

  5. MONA, LISA and VINCI Soon Ready to Travel to Paranal

    Science.gov (United States)

    2000-11-01

    First Instruments for the VLT Interferometer Summary A few months from now, light from celestial objects will be directed for the first time towards ESO's Very Large Telescope Interferometer (VLTI) at the Paranal Observatory (Chile). During this "First Light" event and the subsequent test phase, the light will be recorded with a special test instrument, VINCI (VLT INterferometer Commissioning Instrument). The main components of this high-tech instrument are aptly named MONA (a system that combines the light beams from several telescopes by means of optical fibers) and LISA (the infrared camera). VINCI was designed and constructed within a fruitful collaboration between ESO and several research institutes and industrial companies in France and Germany . It is now being assembled at the ESO Headquarters in Garching (Germany) and will soon be ready for installation at the telescope on Paranal. With the VLTI and VINCI, Europe's astronomers are now entering the first, crucial phase of an exciting scientific and technology venture that will ultimately put the world's most powerful optical/IR interferometric facility in their hands . PR Photo 31/00 : VINCI during tests at the ESO Headquarters in Garching. The VLT Interferometer (VLTI) ESO Press Photo 31/00 ESO Press Photo 31/00 [Preview; JPEG: 400 x 301; 43k] [Normal; JPEG: 800 x 602;208xk] [Full-Res; JPEG: 1923 x 1448; 2.2Mb] PR Photo 31/00 shows the various components of the complex VINCI instrument for the VLT Interferometer , during the current tests at the Optical Laboratory at the ESO Headquarters in Garching (Germany). It will later be installed in "clean-room" conditions within the Interferometric Laboratory at the Paranal Observatory. This electronic photo was obtained for documentary purposes. VINCI (VLT INterferometer Commissioning Instrument) is the "First Light" instrument for the Very Large Telescope Interferometer (VLTI) at the Paranal Observatory (Chile). Early in 2001, it will be used for the first tests

  6. Steady-state free precession with myocardial tagging: CSPAMM in a single breathhold.

    Science.gov (United States)

    Zwanenburg, Jaco J M; Kuijer, Joost P A; Marcus, J Tim; Heethaar, Robert M

    2003-04-01

    A method is presented that combines steady-state free precession (SSFP) cine imaging with myocardial tagging. Before the tagging preparation at each ECG-R wave, the steady-state magnetization is stored as longitudinal magnetization by an alpha/2 flip-back pulse. Imaging is continued immediately after tagging preparation, using linearly increasing startup angles (LISA) with a rampup over 10 pulses. Interleaved segmented k-space ordering is used to prevent artifacts from the increasing signal during the LISA rampup. First, this LISA-SSFP method was evaluated regarding ghost artifacts from the steady-state interruption by comparing LISA with an alpha/2 startup method. Next, LISA-SSFP was compared with spoiled gradient echo (SGRE) imaging, regarding tag contrast-to-noise ratio and tag persistence. The measurements were performed in phantoms and in six subjects applying breathhold cine imaging with tagging (temporal resolution 51 ms). The results show that ghost artifacts are negligible for the LISA method. Compared to the SGRE reference, LISA-SSFP was two times faster, with a slightly better tag contrast-to-noise. Additionally, the tags persisted 126 ms longer with LISA-SSFP than with SGRE imaging. The high efficiency of LISA-SSFP enables the acquisition of complementary tagged (CSPAMM) images in a single breathhold. Copyright 2003 Wiley-Liss, Inc.

  7. Thematic Categorization and Analysis of Peer Reviewed Articles in the LISA Database, 2004-2005. A Review of: Gonzalez-Alcaide, Gregorio, Lourdes Castello-Cogolles, Carolina Navarro-Molina, et al. “Library and Information Science Research Areas: Analysis of Journal Articles in LISA.” Journal of the American Society for Information Science and Technology 59.1 (2008: 150-4.

    Directory of Open Access Journals (Sweden)

    Carol Perryman

    2009-03-01

    Full Text Available Objective – To provide an updated categorization of Library and Information Science (LIS publications and to identify trends in LIS research.Design – Bibliometric study.Setting – The Library and Information Science Abstracts (LISA database via the CSA Illumina interface.Subjects – 11,273 item records published from 2004-2005 and indexed in LISA.Methods – First, a search was set up to retrieve all records from 2004-2005, limited to peer review items (called “arbitrated works” by the authors (150 and excluding book reviews. Second, thematic descriptor terms used for the records were identified. Frequency counts for descriptor term occurrence were compiled using Microsoft Access and Pajek software programs. From the results of this search, the top terms were analyzed using the Kamada-Kawai algorithm in order to eliminate descriptor term co-occurrence frequencies under 30. A cluster analysis was used to depict thematic foci for the remaining records, providing a co-word network that visually identified topic areas of most frequent publication. Conclusions were drawn from these findings, and recommendations for further research were provided.Main Results – The authors identified 18 “thematic research core fields” (152 clustered around three large categories, “World Wide Web”, “Education”, and “Libraries”, plus 12 additional peripheral categories, and provided a schematic of field interrelationships.Conclusion – Domains of greatest focus for research “continue to be of practical and applied nature,” (153 but include increased emphasis on the World Wide Web and communications technologies, as well as on user studies. A table of the most frequently occurring areas of research along with their top three descriptor terms is provided (Table1, 152 (e.g., “World Wide Web” as the top area of research, with “online information retrieval” (268 occurrences, “searching” (132 occurrences, and “web sites” (115

  8. Fundamental performance determining factors of the ultrahigh-precision space-borne optical metrology system for the LISA Pathfinder mission

    Science.gov (United States)

    Hechenblaikner, Gerald; Flatscher, Reinhold

    2013-05-01

    The LISA Pathfinder mission to space employs an optical metrology system (OMS) at its core to measure the distance and attitude between two freely floating test-masses to picometer and nanorad accuracy, respectively, within the measurement band of [1 mHz, 30 mHz]. The OMS is based upon an ultra-stable optical bench with 4 heterodyne interferometers from which interference signals are read-out and processed by a digital phase-meter. Laser frequency noise, power fluctuations and optical path-length variations are suppressed to uncritical levels by dedicated control loops so that the measurement performance approaches the sensor limit imposed by the phasemeter. The system design is such that low frequency common mode noise which affects the read-out phase of all four interferometers is generally well suppressed by subtraction of a reference phase from the other interferometer signals. However, high frequency noise directly affects measurement performance and its common mode rejection depends strongly on the relative signal phases. We discuss how the data from recent test campaigns point towards high frequency phase noise as a likely performance limiting factor which explains some important performance features.

  9. The late inspiral of supermassive black hole binaries with circumbinary gas discs in the LISA band

    Science.gov (United States)

    Tang, Yike; Haiman, Zoltán; MacFadyen, Andrew

    2018-05-01

    We present the results of 2D, moving-mesh, viscous hydrodynamical simulations of an accretion disc around a merging supermassive black hole binary (SMBHB). The simulation is pseudo-Newtonian, with the BHs modelled as point masses with a Paczynski-Wiita potential, and includes viscous heating, shock heating, and radiative cooling. We follow the gravitational inspiral of an equal-mass binary with a component mass Mbh = 106 M⊙ from an initial separation of 60rg (where rg ≡ GMbh/c2 is the gravitational radius) to the merger. We find that a central, low-density cavity forms around the binary, as in previous work, but that the BHs capture gas from the circumbinary disc and accrete efficiently via their own minidiscs, well after their inspiral outpaces the viscous evolution of the disc. The system remains luminous, displaying strong periodicity at twice the binary orbital frequency throughout the entire inspiral process, all the way to the merger. In the soft X-ray band, the thermal emission is dominated by the inner edge of the circumbinary disc with especially clear periodicity in the early inspiral. By comparison, harder X-ray emission is dominated by the minidiscs, and the light curve is initially more noisy but develops a clear periodicity in the late inspiral stage. This variability pattern should help identify the electromagnetic counterparts of SMBHBs detected by the space-based gravitational-wave detector LISA.

  10. Trap-efficiency investigation, Bernalillo Floodwater Retarding Reservoir No. 1 (Piedra Lisa Arroyo) near Bernalillo, New Mexico, water years 1956-1974

    Science.gov (United States)

    Funderburg, D.E.

    1977-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Soil Conservation Service, began an investigation of sedimentation of Bernalillo Floodwater Retarding Reservoir No. 1 (Piedra Lisa Arroyo) near Bernalillo, New Mexico in 1956. This investigation was part of a nationwide investigation of the trap efficiency of detention reservoirs. Reservoirs No. 1 is normally a dry reservoir and runoff from the 10.6 sq km drainage area generally occurs from high-intensity summer thundershowers. The mesa area of the drainage basin was treated to prevent erosion and gullying and to retard rapid runoff of rainfall. The land treatment consisted of pits, terraces, seeding, and restricted grazing. The total outflow recorded for the period of record (July 19, 1956 to June 30, 1974) was 133 acre-feet, yielding 1 ,439 tons of sediment. Over 99 percent of the coarse sediments and a high percentage of the silts and clays were deposited in the reservoir before reaching the outflow pipe. The determined trap efficiency of Reservoir No. 1 was 96 percent for the period of record. (Woordard-USGS)

  11. Searching for galactic white-dwarf binaries in mock LISA data using an F-statistic template bank

    International Nuclear Information System (INIS)

    Whelan, John T; Prix, Reinhard; Khurana, Deepak

    2010-01-01

    We describe an F-statistic search for continuous gravitational waves from galactic white-dwarf binaries in simulated LISA data. Our search method employs a hierarchical template-grid-based exploration of the parameter space. In the first stage, candidate sources are identified in searches using different simulated laser signal combinations (known as TDI variables). Since each source generates a primary maximum near its true 'Doppler parameters' (intrinsic frequency and sky position) as well as numerous secondary maxima of the F-statistic in Doppler parameter space, a search for multiple sources needs to distinguish between true signals and secondary maxima associated with other 'louder' signals. Our method does this by applying a coincidence test to reject candidates which are not found at nearby parameter space positions in searches using each of the three TDI variables. For signals surviving the coincidence test, we perform a fully coherent search over a refined parameter grid to provide an accurate parameter estimation for the final candidates. Suitably tuned, the pipeline is able to extract 1989 true signals with only 5 false alarms. The use of the rigid adiabatic approximation allows recovery of signal parameters with errors comparable to statistical expectations, although there is still some systematic excess with respect to statistical errors expected from Gaussian noise. An experimental iterative pipeline with seven rounds of signal subtraction and reanalysis of the residuals allows us to increase the number of signals recovered to a total of 3419 with 29 false alarms.

  12. Searching for galactic white-dwarf binaries in mock LISA data using an F-statistic template bank

    Energy Technology Data Exchange (ETDEWEB)

    Whelan, John T [Center for Computational Relativity and Gravitation, School of Mathematical Sciences, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623 (United States); Prix, Reinhard [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), D-30167 Hannover (Germany); Khurana, Deepak, E-mail: john.whelan@astro.rit.ed, E-mail: reinhard.prix@aei.mpg.d [Indian Institute of Technology, Kharagpur, West Bengal 721302 (India)

    2010-03-07

    We describe an F-statistic search for continuous gravitational waves from galactic white-dwarf binaries in simulated LISA data. Our search method employs a hierarchical template-grid-based exploration of the parameter space. In the first stage, candidate sources are identified in searches using different simulated laser signal combinations (known as TDI variables). Since each source generates a primary maximum near its true 'Doppler parameters' (intrinsic frequency and sky position) as well as numerous secondary maxima of the F-statistic in Doppler parameter space, a search for multiple sources needs to distinguish between true signals and secondary maxima associated with other 'louder' signals. Our method does this by applying a coincidence test to reject candidates which are not found at nearby parameter space positions in searches using each of the three TDI variables. For signals surviving the coincidence test, we perform a fully coherent search over a refined parameter grid to provide an accurate parameter estimation for the final candidates. Suitably tuned, the pipeline is able to extract 1989 true signals with only 5 false alarms. The use of the rigid adiabatic approximation allows recovery of signal parameters with errors comparable to statistical expectations, although there is still some systematic excess with respect to statistical errors expected from Gaussian noise. An experimental iterative pipeline with seven rounds of signal subtraction and reanalysis of the residuals allows us to increase the number of signals recovered to a total of 3419 with 29 false alarms.

  13. Virginia Tech Professor Explains "The Simpsons" Influence On American Pop Culture

    OpenAIRE

    Calhoun, Annette

    2003-01-01

    "If cartoons were meant for adults, they'd put them on in prime time." -- Lisa Simpson, "The Simpsons", FOX Television Network. Three hundred prime time episodes later, "The Simpsons" is set to emerge as America's longest running sitcom. Homer, Bart, Marge, Lisa, and baby Maggie are among the most beloved dysfunctionals in television history. Their 300th show premiers on the FOX-TV network Feb. 16.

  14. Lasnamäe linnaosa koolieelsete lasteasutuste põhimääruste kinnitamine : [17.11.1999

    Index Scriptorium Estoniae

    2000-01-01

    Lisa 1: Tallinna Arbu lasteaia põhimäärus Lisa 2: Tallinna Asunduse Lasteaia põhimäärus Lisa 3: Tallinna Kalevipoja Lasteaia põhimäärus Lisa 4: Tallinna Killustiku Lasteaia põhimäärus Lisa 5: Tallinna Kivila Lasteaia põhimäärus Lisa 6: Tallinna Kivimurru Lasteaia põhimäärus Lisa 7: Tallinna Kuristiku Lasteaia põhimäärus Lisa 8: Tallinna Lasteaia Laagna Rukkilill põhimäärus Lisa 9: Tallinna Liikuri Lasteaia põhimäärus Lisa 10: Tallinna Lindakivi Lasteaia põhimäärus Lisa 11: Tallinna Linnamäe Lasteaia põhimäärus Lisa 12: Tallinna Loitsu Lasteaia põhimäärus Lisa 13: Tallinna Läänemere Lasteaia põhimäärus Lisa 14: Tallinna Mahtra Lasteaia põhimäärus Lisa 15: Tallinna Majaka Lasteaia põhimäärus Lisa 16: Tallinna Muhu Lasteaia põhimäärus Lisa 17: Tallinna Mustakivi Lasteaia põhimäärus Lisa 18: Tallinna Pae Lasteaia põhimäärus Lisa 19: Tallinna Paekaare Lasteaia põhimäärus Lisa 20: Tallinna Pallasti Lasteaia põhimäärus Lisa 21: Tallinna Priisle Lasteaia põhimäärus Lisa 22: Tallinna Raadiku Lasteaia põhimäärus Lisa 23: Tallinna Seli Lasteaia põhimäärus Lisa 24: Tallinna Sikupilli Lasteaia põhimäärus Lisa 25: Tallinna Suur-Pae Lasteaia põhimäärus Lisa 26: Tallinna Vormsi Lasteaia põhimäärus Lisa 27: Tallinna Ülemiste Lasteaia põhimäärus Lisa 28: Tallinna Ümera Lasteaia põhimääru. Kogumikus märkus: lisadega saab tutvuda linnakantselei üldosakonna arhiivis

  15. Põhja-Tallinna linnaosa koolieelsete lasteasutuste põhimääruste kinnitamine

    Index Scriptorium Estoniae

    2000-01-01

    Lisa 1: Lasteaia Maasikas põhimäärus. Lisa 2: Lasteaia Mesipuu põhimäärus. Lisa 3: Lasteaia Mudila põhimäärus. Lisa 4: Lasteaia Vahtrake põhimäärus. Lisa 5: Lasteaia Kelluke põhimäärus. Lisa 6: Lasteaia Päikene põhimäärus. Lisa 7: Lasteaia Pääsupesa põhimäärus. Lisa 8: Lasteaia Kajakas põhimäärus. Lisa 9: Lasteaia Ojake põhimäärus. Lisa 10: Lasteaia Rukkirääk põhimäärus. Lisa 11: Kaera Lasteaia põhimäärus. Lisa 12: Kopli Lasteaia põhimäärus. Lisa 13: Sitsi Lasteaia põhimäärus. Lisa 14: Lastesõime Pöialpoiss põhimäärus. Lisa 15: Lastesõime Päkapikk põhimäärus. Lisa 16: Lasteaia Naeratus põhimäärus. Lisa 17: Kalamaja Lasteaia põhimäärus. Lisa 18: Lasteaia Pajuke põhimäärus. Lisa 19: Pelguranna lasteaia põhimäärus. Lisa 20: Taime Lasteaia põhimäärus. Lisa 21: Kolde Lasteai põhimäärus. Kogumikus märkus: lisadega saab tutvuda linnakantselei üldosakonna arhiivis

  16. Tallinna Kesklinna koolieelsete lasteasutuste põhimääruste kinnitamine

    Index Scriptorium Estoniae

    2000-01-01

    Lisa 1: Tallinna 3. Lasteaia põhimäärus Lisa 2: Tallinna 5. Lasteaia põhimäärus Lisa 3: Tallinna 9. Lasteaia põhimäärus Lisa 4: Tallinna 13. Lasteaia põhimäärus - Kehtetu: Tallinna Linnavalitsuse 13. detsembri 2000 määrus nr 85. Lisa 5: Tallinna 22. Lasteaia põhimäärus Lisa 6: Tallinna 24. Lasteaia põhimäärus Lisa 7: Tallinna 37. Lasteaia põhimäärus Lisa 8: Tallinna 47. Lasteaia põhimäärus Lisa 9: Tallinna 48. Lasteaia põhimäärus Lisa 10: Tallinna 53. Lasteaia põhimäärus Lisa 11: Tallinna 60. Lasteaia põhimäärus Lisa 12: Tallinna 64. Lasteaia põhimäärus Lisa 13: Tallinna 10. Lastesõime põhimäärus Lisa 14: Tallinna 32. Lastesõime põhimäärus Lisa 15: Tallinna 57. Lastesõime põhimäärus Lisa 16: Tallinna Lasteaia Saareke põhimäärus Lisa 17: Rõõmutarekese Lasteaia põhimäärus Lisa 18: Siisikese Lasteaia põhimäärus Lisa 19: Tallinna Lasteaia Südameke põhimäärus Lisa 20: Tallinna 26. Lasteaia põhimäärus Lisa 21: Kadrioru Lasteaia põhimäärus Lisa 22: Tallinna Virmalise Lasteaia põhimäärus Lisa 23: Tallinna Terakese Lasteaia põhimäärus Lisa 24: Tallinna Päikesejänku Lasteaia põhimäärus Lisa 25: Tallinna Liivalaia Lasteaia põhimäärus Lisa 26: Tallinna 86. Lasteaia põhimäärus Lisa 27: Tallinna 89. Lasteaia põhimäärus Lisa 28: Tallinna Luha Lasteaia põhimäärus Lisa 29: Tallinna Suitsupääsupesa Lasteaia põhimäärusLisa 30: Tallinna 142. Lasteaia põhimäärus Lisa 31: Tallinna 116. Lasteaia põhimäärus Lisa 32: Tallinna 160. Lasteaia põhimäärus Lisa 33: Lastesõime Aasalill põhimäärus Lisa 34: Muumipere Lastesõime põhimäärus Lisa 35: Lastesõime Planeedi Mudila põhimäärus. Kogumikus märkus: lisadega saab tutvuda linnakantselei üldosakonna arhiivis

  17. Tallinna Kesklinna munitsipaalkoolide põhimääruste kinnitamine

    Index Scriptorium Estoniae

    2000-01-01

    Lisa 1: Gustav Adolfi Gümnaasiumi põhimäärus Lisa 2: Tallinna Ühisgümnaasiumi põhimäärus Lisa 3: Tallinna 21. Kooli põhimäärus Lisa4: Kadrioru Saksa Gümnaasiumi põhimäärus Lisa 5: Jakob Westholmi Gümnaasiumi põhimäärus Lisa 6: Liivalaia Gümnaasiumi põhimäärus Lisa 7: Tallinna Prantsuse Lütseumi põhimäärus Lisa 8: Tallinna Reaalkooli põhimäärus Lisa 9: Tallinna Magdaleena Lasteaed-Algkooli põhimäärus Lisa 10: Tallinna Vanalinna Täiskasvanute Gümnaasiumi põhimäärus Lisa 11: Tallinna Kesklinna Täiskasvanute Gümnaasiumi põhimäärus Lisa 12: Tallinna Kesklinna Vene Gümnaasiumi põhimäärus Lisa 13: Tallinna Tõnismäe Reaalkooli põhimäärus Lisa 14: Tallinna Juhkentali Gümnaasiumi põhimäärus Lisa 15: Tallinna Humanitaargümnaasiumi põhimäärus Lisa 16: Tallinna Tondi Lasteaed-Algkooli põhimäärus Lisa 17: Tallinnna Juudi Kooli põhimäärus Lisa 18: Tallinna Inglise Kolledzi põhimäärus Lisa 19: Tallinna 11. Õhtukeskkooli põhimäärus Lisa 20: Tallinna Kadrioru Põhikooli põhimäärus. Kogumikus märkus: lisadega saab tutvuda linnakantselei üldosakonna arhiivis

  18. Design and construction of an optical test bed for LISA imaging systems and tilt-to-length coupling

    International Nuclear Information System (INIS)

    Chwalla, M; Fitzsimons, E; Danzmann, K; Fernández Barranco, G; Gerberding, O; Heinzel, G; Lieser, M; Schuster, S; Schwarze, T S; Tröbs, M; Zwetz, M; Killow, C J; Perreur-Lloyd, M; Robertson, D I; Ward, H

    2016-01-01

    The laser interferometer space antenna (LISA) is a future space-based interferometric gravitational-wave detector consisting of three spacecraft in a triangular configuration. The interferometric measurements of path length changes between satellites will be performed on optical benches in the satellites. Angular misalignments of the interfering beams couple into the length measurement and represent a significant noise source. Imaging systems will be used to reduce this tilt-to-length coupling. We designed and constructed an optical test bed to experimentally investigate tilt-to-length coupling. It consists of two separate structures, a minimal optical bench and a telescope simulator. The minimal optical bench comprises the science interferometer where the local laser is interfered with light from a remote spacecraft. In our experiment, a simulated version of this received beam is generated on the telescope simulator. The telescope simulator provides a tilting beam, a reference interferometer and an additional static beam as a phase reference. The tilting beam can either be a flat-top beam or a Gaussian beam. We avoid tilt-to-length coupling in the reference interferometer by using a small photo diode placed at an image of the beam rotation point. We show that the test bed is operational with an initial measurement of tilt-to-length coupling without imaging systems. Furthermore, we show the design of two different imaging systems whose performance will be investigated in future experiments. (paper)

  19. A Time Domain Waveform for Testing General Relativity

    International Nuclear Information System (INIS)

    Huwyler, Cédric; Jetzer, Philippe; Porter, Edward K

    2015-01-01

    Gravitational-wave parameter estimation is only as good as the theory the waveform generation models are based upon. It is therefore crucial to test General Relativity (GR) once data becomes available. Many previous works, such as studies connected with the ppE framework by Yunes and Pretorius, rely on the stationary phase approximation (SPA) to model deviations from GR in the frequency domain. As Fast Fourier Transform algorithms have become considerably faster and in order to circumvent possible problems with the SPA, we test GR with corrected time domain waveforms instead of SPA waveforms. Since a considerable amount of work has been done already in the field using SPA waveforms, we establish a connection between leading-order-corrected waveforms in time and frequency domain, concentrating on phase-only corrected terms. In a Markov Chain Monte Carlo study, whose results are preliminary and will only be available later, we will assess the ability of the eLISA detector to measure deviations from GR for signals coming from supermassive black hole inspirals using these corrected waveforms. (paper)

  20. Time-Delay Interferometry

    Directory of Open Access Journals (Sweden)

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  1. The LISA zero-signal solution

    International Nuclear Information System (INIS)

    Tinto, Massimo; Larson, Shane L

    2005-01-01

    We derive a time-delay interferometric (TDI) combination that has zero-response to a gravitational wave signal. This combination, which we have called the zero-signal solution, is a two-parameter family of linear combinations of the generators of the TDI space that has null gravitational wave response when its two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the zero-signal solution does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind

  2. Zooloogia ja Botaanika Instituudi metsasektor : (1947-1963) / Toivo Meikar

    Index Scriptorium Estoniae

    Meikar, Toivo, 1947-

    2002-01-01

    Lisa 1: ZBI metsasektori töötajad 1947-1963. Lisa 2: ZBI metsasektori ja teiste allüksuste lõpetatud metsanduslike uurimistööde teemad 1953-1961. Lisa 3: ZBI metsanduslik uurimistemaatika 1960.aastal. Lisa 4: ENSV metsandusliku uurimistöö detailplaan 1963. Lisa 5: Metsanduse Teadusliku Uurimise Laboratooriumile 1963.aastal üleantud uurimistööde teemad. Lisa 6: ZBI metsasektori töötajate ja aspirantide poolt avaldatud trükised

  3. A Homogeneous Time-Resolved Fluorescence Immunoassay Method for the Measurement of Compound W.

    Science.gov (United States)

    Huang, Biao; Yu, Huixin; Bao, Jiandong; Zhang, Manda; Green, William L; Wu, Sing-Yung

    2018-01-01

    Using compound W (a 3,3'-diiodothyronine sulfate [T 2 S] immuno-crossreactive material)-specific polyclonal antibodies and homogeneous time-resolved fluorescence immunoassay assay techniques (AlphaLISA) to establish an indirect competitive compound W (ICW) quantitative detection method. Photosensitive particles (donor beads) coated with compound W or T 2 S and rabbit anti-W antibody were incubated with biotinylated goat anti-rabbit antibody. This constitutes a detection system with streptavidin-coated acceptor particle. We have optimized the test conditions and evaluated the detection performance. The sensitivity of the method was 5 pg/mL, and the detection range was 5 to 10 000 pg/mL. The intra-assay coefficient of variation averages W levels in extracts of maternal serum samples. This may have clinical application to screen congenital hypothyroidism in utero.

  4. Lost in Translation: U.S. Forces and Crime in Japan

    Science.gov (United States)

    2015-09-01

    attended by U.S. Secretary of State Hillary Clinton, U.S. Secretary of Defense William Gates, Japanese Foreign Minister Takeaki Matsumoto and Japanese...particular, have been at the heart of the controversy.102 According to Lisa Takeuchi Cullen , “Okinawa hates America, and Okinawa loves America...February 3, 2010, http://nippon.com/en/in-depth/a00501/. 103 Lisa Takeuchi Cullen , “Sex and Race in Okinawa,” Time, August 19, 2001, http

  5. Porting Gravitational Wave Signal Extraction to Parallel Virtual Machine (PVM)

    Science.gov (United States)

    Thirumalainambi, Rajkumar; Thompson, David E.; Redmon, Jeffery

    2009-01-01

    Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA mission to be launched around 2012. The Gravitational Wave detection is fundamentally the determination of frequency, source parameters, and waveform amplitude derived in a specific order from the interferometric time-series of the rotating LISA spacecrafts. The LISA Science Team has developed a Mock LISA Data Challenge intended to promote the testing of complicated nested search algorithms to detect the 100-1 millihertz frequency signals at amplitudes of 10E-21. However, it has become clear that, sequential search of the parameters is very time consuming and ultra-sensitive; hence, a new strategy has been developed. Parallelization of existing sequential search algorithms of Gravitational Wave signal identification consists of decomposing sequential search loops, beginning with outermost loops and working inward. In this process, the main challenge is to detect interdependencies among loops and partitioning the loops so as to preserve concurrency. Existing parallel programs are based upon either shared memory or distributed memory paradigms. In PVM, master and node programs are used to execute parallelization and process spawning. The PVM can handle process management and process addressing schemes using a virtual machine configuration. The task scheduling and the messaging and signaling can be implemented efficiently for the LISA Gravitational Wave search process using a master and 6 nodes. This approach is accomplished using a server that is available at NASA Ames Research Center, and has been dedicated to the LISA Data Challenge Competition. Historically, gravitational wave and source identification parameters have taken around 7 days in this dedicated single thread Linux based server. Using PVM approach, the parameter extraction problem can be reduced to within a day. The low frequency computation and a proxy signal-to-noise ratio are calculated in separate nodes that are controlled by the master

  6. Eesti elamumajanduse arengukava aastani 2010

    Index Scriptorium Estoniae

    1999-01-01

    Lisa 1: Vabariigi Valitsuse korraldused 21. aprillist 1998. a. ja 16. juunist 1998. a. Elamumajanduse asjatundjate komisjoni moodustamise kohta; Lisa 2: Avaliku elamufondi struktuur Eestis aastatel 1994-1996 (%); Lisa 3: Leibkondade keskmine väljaminek kuus leibkonnaliikme kohta 1997. a.; Lisa 4: Eluasemefondi kasutuskorralduse skeem

  7. Comparing interferometry techniques for multi-degree of freedom test mass readout

    International Nuclear Information System (INIS)

    Isleif, Katharina-Sophie; Gerberding, Oliver; Mehmet, Moritz; Schwarze, Thomas S; Heinzel, Gerhard; Danzmann, Karsten

    2016-01-01

    Laser interferometric readout systems with 1pm/Hz precision over long time scales have successfully been developed for LISA and LISA Pathfinder. Future gravitational physics experiments, for example in the fields of gravitational wave detection and geodesy, will potentially require similar levels of displacement and tilt readouts of multiple test masses in multiple degrees of freedom. In this article we compare currently available classic interferometry schemes with new techniques using phase modulations and complex readout algorithms. Based on a simple example we show that the new techniques have great potential to simplify interferometric readouts. (paper)

  8. Identifying decaying supermassive black hole binaries from their variable electromagnetic emission

    Energy Technology Data Exchange (ETDEWEB)

    Haiman, Zoltan; Menou, Kristen [Department of Astronomy, Columbia University, New York, NY (United States); Kocsis, Bence [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Lippai, Zoltan; Frei, Zsolt [Institute of Physics, Eoetvoes University, Budapest (Hungary)

    2009-05-07

    Supermassive black hole binaries (SMBHBs) with masses in the mass range approx(10{sup 4}-10{sup 7}) M{sub o-dot}/(1 + z), produced in galaxy mergers, are thought to complete their coalescence due to the emission of gravitational waves (GWs). The anticipated detection of the GWs by the future Laser Interferometric Space Antenna (LISA) will constitute a milestone for fundamental physics and astrophysics. While the GW signatures themselves will provide a treasure trove of information, if the source can be securely identified in electromagnetic (EM) bands, this would open up entirely new scientific opportunities, to probe fundamental physics, astrophysics and cosmology. We discuss several ideas, involving wide-field telescopes, that may be useful in locating electromagnetic counterparts to SMBHBs detected by LISA. In particular, the binary may produce a variable electromagnetic flux, such as a roughly periodic signal due to the orbital motion prior to coalescence, or a prompt transient signal caused by shocks in the circumbinary disc when the SMBHB recoils and 'shakes' the disc. We discuss whether these time-variable EM signatures may be detectable, and how they can help in identifying a unique counterpart within the localization errors provided by LISA. We also discuss a possibility of identifying a population of coalescing SMBHBs statistically, in a deep optical survey for periodically variable sources, before LISA detects the GWs directly. The discovery of such sources would confirm that gas is present in the vicinity and is being perturbed by the SMBHB-serving as a proof of concept for eventually finding actual LISA counterparts.

  9. Identifying decaying supermassive black hole binaries from their variable electromagnetic emission

    International Nuclear Information System (INIS)

    Haiman, Zoltan; Menou, Kristen; Kocsis, Bence; Lippai, Zoltan; Frei, Zsolt

    2009-01-01

    Supermassive black hole binaries (SMBHBs) with masses in the mass range ∼(10 4 -10 7 ) M o-dot /(1 + z), produced in galaxy mergers, are thought to complete their coalescence due to the emission of gravitational waves (GWs). The anticipated detection of the GWs by the future Laser Interferometric Space Antenna (LISA) will constitute a milestone for fundamental physics and astrophysics. While the GW signatures themselves will provide a treasure trove of information, if the source can be securely identified in electromagnetic (EM) bands, this would open up entirely new scientific opportunities, to probe fundamental physics, astrophysics and cosmology. We discuss several ideas, involving wide-field telescopes, that may be useful in locating electromagnetic counterparts to SMBHBs detected by LISA. In particular, the binary may produce a variable electromagnetic flux, such as a roughly periodic signal due to the orbital motion prior to coalescence, or a prompt transient signal caused by shocks in the circumbinary disc when the SMBHB recoils and 'shakes' the disc. We discuss whether these time-variable EM signatures may be detectable, and how they can help in identifying a unique counterpart within the localization errors provided by LISA. We also discuss a possibility of identifying a population of coalescing SMBHBs statistically, in a deep optical survey for periodically variable sources, before LISA detects the GWs directly. The discovery of such sources would confirm that gas is present in the vicinity and is being perturbed by the SMBHB-serving as a proof of concept for eventually finding actual LISA counterparts.

  10. Flujo de compuestos organoclorados en las cadenas troficas de la cienaga de Santa Marta

    Directory of Open Access Journals (Sweden)

    Hernado Campos Néstor

    1993-12-01

    Full Text Available Monthly samples of seston and fish species of different throphic levels were done at the Ciénaga Grande de Santa Marta in orderto describe organochlorinated compounds dynamics. The fish used were: atlantic anchoveta, mulletand catfish. The organochlorinated contents were determined by gas-liquid chromatography using n-Hexane and Acetonitrilo as extraction solvents. The results were compared to 14 organochlorinated pure patrons. The following accumulations patterns were found: atlantic nchoveta 2240 times, mullet 2343 times and catfish 21800 times and the magnifying factors among the differents thropic levels: mullet/atlantic anchoveta = 1.47, catfish/atlantic anchoveta = 2.6 and catfish/mullet = 3.3 The transport model of the organochlorinated compounds in the Cienaga Grande de Santa Marta is described bassed in these results.Con el fin de describir la dinámica de los compuestos organoclorados a través de la red trófica de la Ciénaga Grande de Santa Marta, se adelantaron muestreos simultáneos del seston y de peces de diferentes niveles tróficos: bocona (cetengraulis edentulus planctófago; lisa (Mugil incilis detritívoro; el chivo (Ariopsis boniiíei; carnívoro. Se determinaron los contenidos de organoclorados por cromatografía gas-líquido, empleando n-hexano y acetonitrilo como solventes de extracción y se compararon con 14 patrones puros de organoclorados. Los factores de acumulación para la bocona son de 2240 veces, para la lisa 2343 y para el chivo 21800. Los factores de magnificación entre los diferentes niveles tróficos son lisa/bocona = 1.47; chivo/lisa = 3.3; chivo/bocona = 2.6. Se describe el modelo de flujos de los organoclorados en la Ciénaga Grande de Santa Marta con base en estos resultados.

  11. Data combinations accounting for LISA spacecraft motion

    International Nuclear Information System (INIS)

    Shaddock, Daniel A.; Tinto, Massimo; Estabrook, Frank B.; Armstrong, J.W.

    2003-01-01

    The laser interferometer space antenna is an array of three spacecraft in an approximately equilateral triangle configuration which will be used as a low-frequency gravitational wave detector. We present here new generalizations of the Michelson- and Sagnac-type time-delay interferometry data combinations. These combinations cancel laser phase noise in the presence of different up and down propagation delays in each arm of the array, and slowly varying systematic motion of the spacecraft. The gravitational wave sensitivities of these generalized combinations are the same as previously computed for the stationary cases, although the combinations are now more complicated. We introduce a diagrammatic representation to illustrate that these combinations are actually synthesized equal-arm interferometers

  12. Space-based detectors

    DEFF Research Database (Denmark)

    Sesana, A.; Weber, W. J.; Killow, C. J.

    2014-01-01

    ) is planned for 2015. This mission and its payload “LISA Technology Package” will demonstrate key technologies for LISA. In this context, reference masses in free fall for LISA, and gravitational physics in general, was described by William Weber, laser interferometry at the pico-metre level and the optical...... of the LISA technology that are not going to be demonstrated by LPF, but under intensive development at the moment, were presented by Oliver Jennrich and Oliver Gerberding. Looking into the future, Japan is studying the design of a mid-frequency detector called DECIGO, which was discussed by Tomotada Akutsu...... as technology demonstrator. This will be the first inter-spacecraft laser interferometer and has many aspects in common with the LISA long arm, as discussed by Andrew Sutton....

  13. Hollandi Heineken võib Saksa õlletootja Krombacheri üle võtta / Katri Soe-Suren

    Index Scriptorium Estoniae

    Soe-Suren, Katri

    2008-01-01

    Financial Times Deutschland andmetel plaanib Hollandi Heinekeni kontsern Saksa õlletootja Krombacheri ülevõtmist, Heinekeni sunnib laienema USA päritolu Anheuser-Buschi ülevõtmine InBevi poolt juuli keskpaigas. Lisa

  14. Desarrollo y caracterización de un nuevo esmalte antideslizante de textura lisa y de fácil limpieza para baldosas de gres porcelánico

    Directory of Open Access Journals (Sweden)

    E. Barrachina Albert

    2016-03-01

    Full Text Available Dada la problemática que presentan los esmaltes antideslizantes convencionales, los cuales poseen una rugosidad superficial que dificulta la limpieza de la superficie de la pieza, se ha diseñado un esmalte antideslizante de naturaleza vitrocerámica que es resistente a las manchas y presenta una textura lisa, de tacto suave. Para ello, se han utilizado nuevas fritas de naturaleza mate y materias primas de composiciones similares, suficientemente refractarias para ser adecuadas para esmaltar piezas de gres porcelánico. El esmalte vitrocerámico así obtenido se ha caracterizado a través de varias técnicas instrumentales (fluorescencia de rayos X [FRX], microscopia electrónica de barrido [MEB], difracción de rayos X [DRX], perfilometría mecánica y medidas de microdureza con el fin de comprobar la naturaleza de las fases cristalizadas, su morfología, la rugosidad superficial y la microdureza de la pieza acabada. Además, se ha valorado la calidad de la pieza esmaltada mediante las normativas de resistencia química, resistencia a las manchas y resistencia a la resbaladicidad. El esmalte obtenido ha desvitrificado en cristales de silicoaluminatos de calcio y bario, cumple la normativa de antideslizamiento y es resistente a las manchas, ya que presenta una rugosidad superficial similar a un esmalte no antideslizante.

  15. Adhesive Bonding for Optical Metrology Systems in Space Applications

    International Nuclear Information System (INIS)

    Gohlke, Martin; Schuldt, Thilo; Braxmaier, Claus; Döringshoff, Klaus; Peters, Achim; Johann, Ulrich; Weise, Dennis

    2015-01-01

    Laser based metrology systems become more and more attractive for space applications and are the core elements of planned missions such as LISA (NGO, eLISA) or NGGM where laser interferometry is used for distance measurements between satellites. The GRACE-FO mission will for the first time demonstrate a Laser Ranging Instrument (LRI) in space, starting 2017. Laser based metrology also includes optical clocks/references, either as ultra-stable light source for high sensitivity interferometry or as scientific payload e.g. proposed in fundamental physics missions such as mSTAR (mini SpaceTime Asymmetry Research), a mission dedicated to perform a Kennedy-Thorndike experiment on a satellite in a low-Earth orbit. To enable the use of existing optical laboratory setups, optimization with respect to power consumption, weight and dimensions is necessary. At the same time the thermal and structural stability must be increased. Over the last few years we investigated adhesive bonding of optical components to thermally highly stable glass ceramics as an easy-to-handle assembly integration technology. Several setups were implemented and tested for potential later use in space applications. We realized a heterodyne LISA related interferometer with demonstrated noise levels in the pm-range for translation measurement and nano-radiant-range for tilt measurements and two iodine frequency references on Elegant Breadboard (EBB) and Engineering Model (EM) level with frequency stabilities in the 10 -15 range for longer integration times. The EM setup was thermally cycled and vibration tested. (paper)

  16. The impact of dredging on residence time in the Amba estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Velamala, S.N.; Thomas, J.; Bari, S.; Kachave, S.

    for the Musa estuary (Persian Gulf), Payandeh, Zaker and Niksokhan (2014) showed that the persistency of currents was a useful indicator for identifying areas of pollutant load accumulation. The RTs have also been studied by several authors (e.g. Luff....W.A Naqvi, Director, National Institute of Oceanography, India, for their constant encouragement and support during the work. Authors would also like to express their gratitude to Lisa V. Lucas, Geological Survey, US for her comments on this manuscript...

  17. Sistema de reforço à punção de lajes lisas de concreto armado com polímeros reforçados com fibra de carbono (PRFC

    Directory of Open Access Journals (Sweden)

    G. S. Santos

    Full Text Available Este artigo apresenta um estudo analítico de uma recente técnica de reforço de lajes lisas de concreto armado contra o fenômeno da punção. Trata-se da utilização de mantas de Polímeros Reforçados com Fibra de Carbono (PRFC como armadura de cisalhamento. O sistema, denominado Stitch, foi idealizado por Sissakis (2002 [1] e consiste em se formar um laço completo entre dois furos subsequentes como pontos de costura . O objetivo deste artigo é avaliar a aplicação de adaptações das principais normas, nacional e internacionais, de dimensionamento à punção de lajes com pilar interno, sem a atuação de momentos fletores e associadas às limitações do ACI 440 2R:2008 [6], a qual trata do reforço de estruturas com PRFC. Os Resultados mostram que a NBR 6118:2007 [4] apresentou o menor grau de dispersão, com alguns resultados contra a segurança. O ACI 318:2011 possui uma tendência mais conservadora, e o EUROCODE 2:2004 [4] e Model Code (2010 [5] possuem resultados intermediários, com esse ligeiramente mais conservador que aquele.

  18. Otsige naist : vana trikk valimiskampaanias / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2004-01-01

    Suurlehed Washington Post ja New York Times pole käsitlenud presidendikandidaadiks pürgiva John Kerry salasuhte teemat, mida levitati Internetis. Bill Clintoniga seotud skandaalist tema valimiskampaania ajal. Lisa: Presidendid ja nende naised

  19. An Examination of Acceptable Navigation Accuracy for LISA Orbits

    National Research Council Canada - National Science Library

    Smythe, Reid W

    2007-01-01

    .... Preliminary analysis indicated the values of each parameter varied sinusoidally, and increasing the initial error conditions tended to reduce the time each parameter fell within the acceptable tolerance values...

  20. Image quality comparison of two multifocal IOLs: influence of the pupil.

    Science.gov (United States)

    García-Domene, Mari Carmen; Felipe, Adelina; Peris-Martínez, Cristina; Navea, Amparo; Artigas, Jose M; Pons, Álvaro M

    2015-04-01

    To evaluate the effect of pupil size on image quality of a sectorial multifocal intraocular lens (IOL), the Lentis Mplus (Oculentis GmbH, Berlin, Germany), and the Acri.LISA IOL (Carl Zeiss Meditec, Jena, Germany). The authors measured the MTFs of the Lentis Mplus LS-312 IOL and the Acri.LISA 366D IOL with three different sizes of pupil diameters: 3, 4, and 5 mm. The MTF was calculated from the cross-line spread function recorded with the OPAL Vector System (Image Science Ltd., Oxford, UK) by using fast Fourier-transform techniques. In distance focus, the image quality provided by the Lentis Mplus IOL was better than that of the Acri. LISA IOL with all pupil diameters. In near focus, the MTF of the Acri.LISA IOL was better with a 3-mm pupil, but poor with larger pupils. The aberration effect was equal in both IOLs in distance focus, but in near focus and with a 3-mm pupil, the Acri.LISA IOL was less affected by the aberration than the Lentis Mplus IOL. The Lentis Mplus IOL provides better distance image quality than the Acri.LISA IOL, whereas the near image quality of the Acri.LISA IOL is better with small-pupil diameter. The sectorial design makes this IOL more suitable for patients with a pupil diameter greater than 3 mm. Copyright 2015, SLACK Incorporated.

  1. Iodine frequency references for space

    International Nuclear Information System (INIS)

    Schuldt, Thilo; Braxmaier, Claus; Döringshoff, Klaus; Peters, Achim; Oswald, Markus; Johann, Ulrich

    2017-01-01

    Optical frequency references are a key element for the realization of future space missions. They are needed for missions related to tests of fundamental physics, gravitational wave detection, Earth observation and navigation and ranging. In missions such as GRACE follow-on or LISA the optical frequency reference is used as light source for high-sensitivity inter-satellite distance metrology. While cavity-based systems are current baseline e.g. for LISA, frequency stabilization on a hyperfine transition in molecular iodine near 532 nm is a promising alternative. Due to its absolute frequency, iodine standards crucially simplify the initial spacecraft acquisition procedures. Current setups fulfill the GRACE-FO and LISA frequency stability requirements and are realized near Engineering Model level. We present the current status of our developments on Elegant Breadboard (EBB) and Engineering Model (EM) level taking into account specific design criteria for space compatibility such as compactness (size iodine spectroscopy EM: 38 × 18 × 10 cm 3 ) and robustness. Both setups achieved similar frequency stabilities of ∼ 1 · 10 −14 at an integration time of 1 s and below 5 · 10 −15 at integration times between 10 s and 1000 s. Furthermore, we present an even more compact design currently developed for a sounding rocket mission with launch in 2017. (paper)

  2. Modeling of fatigue crack induced nonlinear ultrasonics using a highly parallelized explicit local interaction simulation approach

    Science.gov (United States)

    Shen, Yanfeng; Cesnik, Carlos E. S.

    2016-04-01

    This paper presents a parallelized modeling technique for the efficient simulation of nonlinear ultrasonics introduced by the wave interaction with fatigue cracks. The elastodynamic wave equations with contact effects are formulated using an explicit Local Interaction Simulation Approach (LISA). The LISA formulation is extended to capture the contact-impact phenomena during the wave damage interaction based on the penalty method. A Coulomb friction model is integrated into the computation procedure to capture the stick-slip contact shear motion. The LISA procedure is coded using the Compute Unified Device Architecture (CUDA), which enables the highly parallelized supercomputing on powerful graphic cards. Both the explicit contact formulation and the parallel feature facilitates LISA's superb computational efficiency over the conventional finite element method (FEM). The theoretical formulations based on the penalty method is introduced and a guideline for the proper choice of the contact stiffness is given. The convergence behavior of the solution under various contact stiffness values is examined. A numerical benchmark problem is used to investigate the new LISA formulation and results are compared with a conventional contact finite element solution. Various nonlinear ultrasonic phenomena are successfully captured using this contact LISA formulation, including the generation of nonlinear higher harmonic responses. Nonlinear mode conversion of guided waves at fatigue cracks is also studied.

  3. The impact of realistic models of mass segregation on the event rate of extreme-mass ratio inspirals and cusp re-growth

    International Nuclear Information System (INIS)

    Amaro-Seoane, Pau; Preto, Miguel

    2011-01-01

    One of the most interesting sources of gravitational waves (GWs) for LISA is the inspiral of compact objects on to a massive black hole (MBH), commonly referred to as an 'extreme-mass ratio inspiral' (EMRI). The small object, typically a stellar black hole, emits significant amounts of GW along each orbit in the detector bandwidth. The slowly, adiabatic inspiral of these sources will allow us to map spacetime around MBHs in detail, as well as to test our current conception of gravitation in the strong regime. The event rate of this kind of source has been addressed many times in the literature and the numbers reported fluctuate by orders of magnitude. On the other hand, recent observations of the Galactic centre revealed a dearth of giant stars inside the inner parsec relative to the numbers theoretically expected for a fully relaxed stellar cusp. The possibility of unrelaxed nuclei (or, equivalently, with no or only a very shallow cusp, or core) adds substantial uncertainty to the estimates. Having this timely question in mind, we run a significant number of direct-summation N-body simulations with up to half a million particles to calibrate a much faster orbit-averaged Fokker-Planck code. We show that, under quite generic initial conditions, the time required for the growth of a relaxed, mass segregated stellar cusp is shorter than a Hubble time for MBHs with M . ∼ 6 M o-dot (i.e. nuclei in the range of LISA). We then investigate the regime of strong mass segregation (SMS) for models with two different stellar mass components. Given the most recent stellar mass normalization for the inner parsec of the Galactic centre, SMS has the significant impact of boosting the EMRI rates by a factor of ∼10 in comparison to what would result from a 7/4-Bahcall and Wolf cusp resulting in ∼250 events per Gyr per Milky Way type galaxy. Such an intrinsic rate should translate roughly into ∼10 2 -7 x 10 2 sbh's (EMRIs detected by LISA over a mission lifetime of 2 or 5

  4. Kalevipoeg tänapäeval - ühe tulevase Euroopa kultuuri document humain : psühholoogilis-antropoloogilisi aspekte / Peter Petersen ; tõlkinud Krista Räni

    Index Scriptorium Estoniae

    Petersen, Peter, 1933-

    2003-01-01

    Lisa 1. William Butler Yeats. Ta igatseb endale taevakangaid / tõlkinud Märt Väljataga, lk. 2587 ; Lisa 2. Novalis. Neue Fragmente. Nr. 393 (Novalis. Werke und Briefe. Stuttgart ; Hamburg : Deutscher Bücherbund, 1962), lk. 2587-2588 ; Lisa 3. Tabel väärtuste kohta, mida Kalevipoja-eeposes esile tuuakse, lk. 2588. Bibl. lk. 2589-2590. Tõlgitud käsikirjast: "Kalevipoeg heute - document humain einer künftigen Kultur Europas: psychologisch-anthropologische Aspekte"

  5. 75 FR 65295 - Sitka Resource Advisory Committee

    Science.gov (United States)

    2010-10-22

    ... District Ranger, USDA Forest Service, 204 Siginaka Way, Sitka, AK 99835, or electronically to Lisa Hirsch, RAC Coordinator at [email protected] . FOR FURTHER INFORMATION CONTACT: Lisa Hirsch, RAC...

  6. Vaskjala lahing 22. septembril 1944 / Vello Salo

    Index Scriptorium Estoniae

    Salo, Vello, 1925-

    2008-01-01

    Vaskjala lahingust seitsme osalenu tunnistuste põhjal. Lisatud ka senikehtinud versioon lahingu kohta raamatust "Eesti rahvas Nõukogude Liidu Suures Isamaasõjas 1941-945". Lisa 1: Ründajad, Lisa 2: Kaitsjad

  7. 76 FR 3081 - Sitka Resource Advisory Committee

    Science.gov (United States)

    2011-01-19

    ... Forest Service, 204 Siginaka Way, Sitka, AK 99835, or electronically to Lisa Hirsch, RAC Coordinator at [email protected] . FOR FURTHER INFORMATION CONTACT: Lisa Hirsch, RAC Coordinator Sitka Ranger District...

  8. 76 FR 17105 - Sitka Resource Advisory Committee

    Science.gov (United States)

    2011-03-28

    ... to Lisa Hirsch, Sitka Ranger District, 204 Siginaka Way, Sitka, Alaska 99835. Comments may also be... FURTHER INFORMATION CONTACT: Lisa Hirsch, RAC coordinator, USDA, Tongass NF, Sitka Ranger District, 204...

  9. Augmented kludge waveforms for detecting extreme-mass-ratio inspirals

    Science.gov (United States)

    Chua, Alvin J. K.; Moore, Christopher J.; Gair, Jonathan R.

    2017-08-01

    The extreme-mass-ratio inspirals (EMRIs) of stellar-mass compact objects into massive black holes are an important class of source for the future space-based gravitational-wave detector LISA. Detecting signals from EMRIs will require waveform models that are both accurate and computationally efficient. In this paper, we present the latest implementation of an augmented analytic kludge (AAK) model, publicly available at https://github.com/alvincjk/EMRI_Kludge_Suite as part of an EMRI waveform software suite. This version of the AAK model has improved accuracy compared to its predecessors, with two-month waveform overlaps against a more accurate fiducial model exceeding 0.97 for a generic range of sources; it also generates waveforms 5-15 times faster than the fiducial model. The AAK model is well suited for scoping out data analysis issues in the upcoming round of mock LISA data challenges. A simple analytic argument shows that it might even be viable for detecting EMRIs with LISA through a semicoherent template bank method, while the use of the original analytic kludge in the same approach will result in around 90% fewer detections.

  10. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    Science.gov (United States)

    Congedo, Giuseppe

    2015-03-01

    The basic constituent of interferometric gravitational wave detectors—the test-mass-to-test-mass interferometric link—behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as nongravitational spurious forces. This last contribution is going to be characterized by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system's free evolution dominating the slow displacement dynamics of low-frequency detectors. Working with acceleration also provides an effective way to subtract measured signals acting as systematics, including the actuation forces. Because of the strong similarity with the equations of motion, the optimal subtraction of systematic signals, known within some amplitude and time shift, with the focus on measuring the noise provides an effective way to solve the problem and marginalize over nuisance parameters. The F statistic, in widespread use throughout the gravitation waves community, is included in the method and suitably generalized to marginalize over linear parameters and noise at the same time. The method is applied to LPF simulator data and, thanks to its generality, can also be applied to the data reduction and analysis of future gravitational wave detectors.

  11. 76 FR 31297 - Sitka Resource Advisory Committee

    Science.gov (United States)

    2011-05-31

    ..., Katlian Conference Room, 204 Siginaka Way, Sitka, Alaska. Written comments should be sent to Lisa Hirsch... CONTACT: Lisa Hirsch, RAC coordinator, USDA, Tongass NF, Sitka Ranger District, 204 Siginaka Way, Sitka...

  12. 77 FR 47813 - Sitka Resource Advisory Committee

    Science.gov (United States)

    2012-08-10

    .... Written comments should be sent to Lisa Hirsch, Sitka Ranger District, 204 Siginaka Way, Sitka, Alaska... entry into the building. FOR FURTHER INFORMATION CONTACT: Lisa Hirsch, RAC coordinator, USDA, Tongass NF...

  13. 77 FR 67330 - Sitka Resource Advisory Committee

    Science.gov (United States)

    2012-11-09

    .... Written comments should be sent to Lisa Hirsch, Sitka Ranger District, 204 Siginaka Way, Sitka, Alaska... entry into the building. FOR FURTHER INFORMATION CONTACT: Lisa Hirsch, RAC coordinator, USDA, Tongass NF...

  14. 75 FR 54846 - Sitka Resource Advisory Committee

    Science.gov (United States)

    2010-09-09

    ... Forest Service, 204 Siginaka Way, Sitka, AK 99835, or electronically to Lisa Hirsch, RAC Coordinator at lisahirs[email protected] . FOR FURTHER INFORMATION CONTACT: Lisa Hirsch, RAC Coordinator Sitka Ranger District...

  15. Peter Fisk kutsub innovatiivsusele / Kuldar Kullasepp

    Index Scriptorium Estoniae

    Kullasepp, Kuldar, 1980-

    2007-01-01

    Turunduskonverentsil Password esinenud Suurbritannia turunduskonsultandi Peter Fiski ettekandest. Lisa: Peter Fiski näited suurepärastest äridest. Aasta Turunduskonkursi korraldaja Hando Sinisalu kommentaarid konkursile: Tulemuslikkus ennekõike. Lisa: Turundustegu

  16. Sisetülides Res Publica heitis liidu Keskerakonnaga kõrvale / Urmas Seaver

    Index Scriptorium Estoniae

    Seaver, Urmas, 1973-

    2005-01-01

    Res Publica juhatus otsustas toetada senise koalitsiooni jätkamist Tallinnas. Res Publica ja Reformierakonna täiendatud koalitsioonileppest. Reformierakonna Tallinna piirkonna juhi Keit Pentuse hinnang võimutülile. Lisa: Võimuleppe lisa

  17. LISA Pathfinder author list

    International Nuclear Information System (INIS)

    2017-01-01

    M Armano, 1 H Audley, 2 G Auger, 3 J Baird, 4 M Bassan, 5 P Binetruy, 3 M Born, 2 D Bortoluzzi, 6 N Brandt, 7 M Caleno, 8 A Cavalleri, 9 A Cesarini, 9 M Cruise, 10 K Danzmann, 2 M de Deus Silva, 1 R De Rosa, 11 L Di Fiore, 12 I Diepholz, 2 R Dolesi, 9 N Dunbar, 13 L Ferraioli, 14 V Ferroni, 9 E Fitzsimons, 15 R Flatscher, 7 M Freschi, 1 C García Marrirodriga, 8 R Gerndt, 7 L Gesa, 16 F Gibert, 9 D Giardini, 14 R Giusteri, 9 A Grado, 11 C Grimani, 17 J Grzymisch, 8 I Harrison, 18 G Heinzel, 2 M Hewitson, 2 D Hollington, 4 D Hoyland, 10 M Hueller, 9 H Inchauspé, 3 O Jennrich, 8 P Jetzer, 19 B Johlander, 8 N Karnesis, 2 B Kaune, 2 N Korsakova, 2 C Killow, 20 A Lobo, 16 , I Lloro, 16 L Liu, 9 J.P. López-Zaragoza, 16 R Maarschalkerweerd, 18 D Mance, 14 V Martín, 16 L Martin-Polo, 1 J Martino, 3 F Martin-Porqueras, 1 S Madden, 8 I Mateos, 16 P W McNamara, 8 J Mendes, 18 L Mendes, 1 M Nofrarias, 16 S Paczkowski, 2 M Perreur-Lloyd, 20 A Petiteau, 3 P Pivato, 9 E Plagnol, 3 P Prat, 3 U Ragnit, 8 J Ramos-Castro, 21 J Reiche, 2 D I Robertson, 20 H Rozemeijer, 8 F Rivas, 16 G Russano, 9 P Sarra, 22 A Schleicher, 7 D Shaul, 4 J Slutsky, 23 C F Sopuerta, 16 R Stanga, 24 T Sumner, 4 D Texier, 1 J I Thorpe, 23 C Trenkel, 13 M Troebs, 2 D Vetrugno, 9 S Vitale, 9 G Wanner, 2 H Ward, 20 P Wass, 4 D Wealthy, 13 W J Weber, 9 L Wissel, 2 A Wittchen, 2 A Zambotti, 6 C Zanoni, 6 T Ziegler, 7 and P Zweifel 14 1 European Space Astronomy Centre, European Space Agency, Villanueva de la Cañada, 28692 Madrid, Spain 2 Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik und Universität Hannover, Callinstrasse 38, 30167 Hannover, Germany 3 APC, Univ Paris Diderot, CNRS/IN2P3, CEA/lrfu, Obs de Paris, Sorbonne Paris Cité, France 4 High Energy Physics Group, Physics Department, Imperial College London, Blackett Laboratory, Prince Consort Road, London, SW7 2BW, UK 5 Dipartimento di Fisica, Università di Roma “Tor Vergata”, and INFN, sezione Roma Tor Vergata, I-00133 Roma, Italy 6 Department of Industrial Engineering, University of Trento, via Sommarive 9, 38123 Trento, and Trento Institute for Fundamental Physics and Application / INFN 7 Airbus Defence and Space, Claude-Dornier-Strasse, 88090 Immenstaad, Germany 8 European Space Technology Centre, European Space Agency, Keplerlaan 1, 2200 AG Noordwijk, The Netherlands 9 Dipartimento di Fisica, Università di Trento and Trento Institute for Fundamental Physics and Application / INFN, 38123 Povo, Trento, Italy 10 Department of Physics and Astronomy, University of Birmingham, Birmingham, UK 11 INAF Osservatorio Astronomico di Capodimonte, I-80131 Napoli, Italy and INFN sezione di Napoli, I-80126 Napoli, Italy 12 INFN - Sezione di Napoli, I-80126, Napoli, Italy 13 Airbus Defence and Space, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2AS, UK 14 Institut für Geophysik, ETH Zürich, Sonneggstrasse 5, CH-8092, Zürich, Switzerland 15 The UK Astronomy Technology Centre, Royal Observatory, Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ, UK 16 Institut de Ciències de l’Espai (CSIC-IEEC), Campus UAB, Carrer de Can Magrans s/n, 08193 Cerdanyola del Vallès, Spain 17 DISPEA, Università di Urbino “Carlo Bo”, Via S. Chiara, 27 61029 Urbino/INFN, Italy 18 European Space Operations Centre, European Space Agency, 64293 Darmstadt, Germany 19 Physik Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland 20 SUPA, Institute for Gravitational Research, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK 21 Department d’Enginyeria Electrònica, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain 22 CGS S.p.A, Compagnia Generale per lo Spazio, Via Gallarate, 150 - 20151 Milano, Italy 23 Gravitational Astrophysics Lab, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 USA 24 Dipartimento di Fisica ed Astronomia, Università degli Studi di Firenze and INFN - Sezione di Firenze, I-50019 Firenze, Italy (paper)

  18. Lisa maailmakirjanduse tõlkevaramule

    Index Scriptorium Estoniae

    2006-01-01

    Uued teosed sarjast "Maailmakirjanduse tõlkevaramu": Tirso de Molina "Sevilla pilkaja ja kivist külaline" ja Pedro Calderon de la Barca "Suur Maailmateater" (Tartu : Tartu Ülikooli Kirjastus, 2006)

  19. Caracterização física e química de frutos de três tipos de gravioleira (Annona muricata L. Physical-chemical characterization of fruit of three types of soursop trees (Annona muricata L.

    Directory of Open Access Journals (Sweden)

    Célio Kersul do Sacramento

    2003-08-01

    Full Text Available Frutos de gravioleira dos tipos 'Morada', 'Lisa' e 'Comum', produzidos na região Sul do Estado da Bahia, foram avaliados quanto às características físicas e químicas. Com relação às características físicas, não foram detectadas diferenças de peso entre os tipos Morada (3,21kg, Lisa (2,82kg e Comum (2,39kg. Os frutos do tipo 'Lisa' apresentaram maior rendimento de polpa (85,85% em relação aos frutos dos tipos 'Morada' (83,57% e 'Comum' (83,12%. A menor razão entre o comprimento e o diâmetro, dos frutos tipos 'Morada' e 'Lisa', os caracteriza como cordiformes. Quanto às características químicas, não houve diferença entre os frutos, à exceção do maior valor de açúcares solúveis totais apresentado pelos frutos do tipo Lisa (14,55g/100g. Os valores médios apresentados foram: ºBrix 13,11; acidez 0,94 g/100g; pH 3,46, e vitamina C 37,25mg/100g. Estes valores, com exceção do pH, superaram os valores mínimos estabelecidos no Padrão de Identidade e Qualidade do Ministério da Agricultura, para polpa de graviola.Soursop fruit of types 'Morada', 'Lisa' and 'Comum' produced in the South of the state of Bahia, Brazil, were evaluated as to physical and chemical characteristics. It wasn't detected mean weight differences among the types 'Morada' (3,21kg, 'Lisa' (2,82kg and 'Comum' (2,39kg. Fruits of 'Lisa' presented higher pulp percentage (85,85% in relation to 'Morada' (83,57% and 'Comum' (83,12%. The minor ratio among length and diameter observed on fruits types 'Morada' and 'Lisa', characterize them as cordiforme shape. Except the bigger value of total soluble sugars presented by 'Lisa' fruit (14,55g/100g, it was not significant the difference among soursop fruit types in respect to their chemical characteristics evaluated. which presented the following averages: ºBrix 13,11; acidity 0,94 g/100g, pH 3,46 and vitamin C 37,25mg/100g. These values, except the pH, overcame the minimum values established in the Pattern of

  20. Bush asub uue Iraagi-poliitikaga vigu parandama / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2007-01-01

    USA president George W. Bush tutvustas uut Iraagi-strateegiat. Iraaki saadetakse paarkümmend tuhat USA sõdurit, küsitluse andmeil on 61% ameeriklastest lisasõdurite saatmise vastu. Lisa: USA plaanid Iraagis ja Iraagiga

  1. Inglise firma ründab kõnekaartide ja mobiiltelefonidega Eesti turgu / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2005-01-01

    Inglise firma Primus Telecommunications hakkab Eestis pakkuma soodsaid kaugekõnehindu. Kõnekaardiäriga hakkab tegelema American Tours'i omanik Ülle Turgan. Lisa: Ülle Turgan müüb poole American Toursist. Lisa: Inglise suurfirma

  2. Plaadid / Immo Mihkelson

    Index Scriptorium Estoniae

    Mihkelson, Immo, 1959-

    2003-01-01

    Uutest plaatidest Pachora "Astereotypical", Lisa Stansfield "Biography", The Last Hombres "Redemption", "The Four Feathers", "Liisi Koikson", Paul Simon "On My Way, Don't Know, Where I-m Goin'", Lisa Nilsson "Samlade Sanger 1992-2003", Emma Shapplin "Etterna"

  3. 77 FR 12857 - National Institute of General Medical Sciences; Notice of Closed Meeting

    Science.gov (United States)

    2012-03-02

    ... Sciences Special Emphasis Panel Biomed Career Interventions. Date: March 26, 2012. Time: 8 a.m. to 5 p.m. Agenda: To review and evaluate grant applications. Place: Palomar DC, 2121 P Street, NW., Washington, DC 20037. Contact Person: Lisa Dunbar, Ph.D., Scientific Review Officer, Office of Scientific Review...

  4. The impact of realistic models of mass segregation on the event rate of extreme-mass ratio inspirals and cusp re-growth

    Science.gov (United States)

    Amaro-Seoane, Pau; Preto, Miguel

    2011-05-01

    One of the most interesting sources of gravitational waves (GWs) for LISA is the inspiral of compact objects on to a massive black hole (MBH), commonly referred to as an 'extreme-mass ratio inspiral' (EMRI). The small object, typically a stellar black hole, emits significant amounts of GW along each orbit in the detector bandwidth. The slowly, adiabatic inspiral of these sources will allow us to map spacetime around MBHs in detail, as well as to test our current conception of gravitation in the strong regime. The event rate of this kind of source has been addressed many times in the literature and the numbers reported fluctuate by orders of magnitude. On the other hand, recent observations of the Galactic centre revealed a dearth of giant stars inside the inner parsec relative to the numbers theoretically expected for a fully relaxed stellar cusp. The possibility of unrelaxed nuclei (or, equivalently, with no or only a very shallow cusp, or core) adds substantial uncertainty to the estimates. Having this timely question in mind, we run a significant number of direct-summation N-body simulations with up to half a million particles to calibrate a much faster orbit-averaged Fokker-Planck code. We show that, under quite generic initial conditions, the time required for the growth of a relaxed, mass segregated stellar cusp is shorter than a Hubble time for MBHs with M• boosting the EMRI rates by a factor of ~10 in comparison to what would result from a 7/4-Bahcall and Wolf cusp resulting in ~250 events per Gyr per Milky Way type galaxy. Such an intrinsic rate should translate roughly into ~102-7 × 102 sbh's (EMRIs detected by LISA over a mission lifetime of 2 or 5 years, respectively), depending on the detailed assumptions regarding LISA detection capabilities.

  5. A coherent method for the detection and parameter estimation of continuous gravitational wave signals using a pulsar timing array

    International Nuclear Information System (INIS)

    Wang, Yan; Mohanty, Soumya D.; Jenet, Fredrick A.

    2014-01-01

    The use of a high precision pulsar timing array is a promising approach to detecting gravitational waves in the very low frequency regime (10 –6 -10 –9 Hz) that is complementary to ground-based efforts (e.g., LIGO, Virgo) at high frequencies (∼10-10 3 Hz) and space-based ones (e.g., LISA) at low frequencies (10 –4 -10 –1 Hz). One of the target sources for pulsar timing arrays is individual supermassive black hole binaries which are expected to form in galactic mergers. In this paper, a likelihood-based method for detection and parameter estimation is presented for a monochromatic continuous gravitational wave signal emitted by such a source. The so-called pulsar terms in the signal that arise due to the breakdown of the long-wavelength approximation are explicitly taken into account in this method. In addition, the method accounts for equality and inequality constraints involved in the semi-analytical maximization of the likelihood over a subset of the parameters. The remaining parameters are maximized over numerically using Particle Swarm Optimization. Thus, the method presented here solves the monochromatic continuous wave detection and parameter estimation problem without invoking some of the approximations that have been used in earlier studies.

  6. A coherent method for the detection and parameter estimation of continuous gravitational wave signals using a pulsar timing array

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan; Mohanty, Soumya D.; Jenet, Fredrick A. [Department of Physics and Astronomy, University of Texas at Brownsville, 1 West University Boulevard, Brownsville, TX 78520 (United States)

    2014-11-01

    The use of a high precision pulsar timing array is a promising approach to detecting gravitational waves in the very low frequency regime (10{sup –6}-10{sup –9} Hz) that is complementary to ground-based efforts (e.g., LIGO, Virgo) at high frequencies (∼10-10{sup 3} Hz) and space-based ones (e.g., LISA) at low frequencies (10{sup –4}-10{sup –1} Hz). One of the target sources for pulsar timing arrays is individual supermassive black hole binaries which are expected to form in galactic mergers. In this paper, a likelihood-based method for detection and parameter estimation is presented for a monochromatic continuous gravitational wave signal emitted by such a source. The so-called pulsar terms in the signal that arise due to the breakdown of the long-wavelength approximation are explicitly taken into account in this method. In addition, the method accounts for equality and inequality constraints involved in the semi-analytical maximization of the likelihood over a subset of the parameters. The remaining parameters are maximized over numerically using Particle Swarm Optimization. Thus, the method presented here solves the monochromatic continuous wave detection and parameter estimation problem without invoking some of the approximations that have been used in earlier studies.

  7. Stochastic and Resolvable Gravitational Waves from Ultralight Bosons.

    Science.gov (United States)

    Brito, Richard; Ghosh, Shrobana; Barausse, Enrico; Berti, Emanuele; Cardoso, Vitor; Dvorkin, Irina; Klein, Antoine; Pani, Paolo

    2017-09-29

    Ultralight scalar fields around spinning black holes can trigger superradiant instabilities, forming a long-lived bosonic condensate outside the horizon. We use numerical solutions of the perturbed field equations and astrophysical models of massive and stellar-mass black hole populations to compute, for the first time, the stochastic gravitational-wave background from these sources. In optimistic scenarios the background is observable by Advanced LIGO and LISA for field masses m_{s} in the range ∼[2×10^{-13},10^{-12}] and ∼5×[10^{-19},10^{-16}]  eV, respectively, and it can affect the detectability of resolvable sources. Our estimates suggest that an analysis of the stochastic background limits from LIGO O1 might already be used to marginally exclude axions with mass ∼10^{-12.5}  eV. Semicoherent searches with Advanced LIGO (LISA) should detect ∼15(5) to 200(40) resolvable sources for scalar field masses 3×10^{-13} (10^{-17})  eV. LISA measurements of massive BH spins could either rule out bosons in the range ∼[10^{-18},2×10^{-13}]  eV, or measure m_{s} with 10% accuracy in the range ∼[10^{-17},10^{-13}]  eV.

  8. Evaluating State-of-the-art Object Detector on Challenging Traffic Light Data

    DEFF Research Database (Denmark)

    Jensen, Morten Bornø; Nasrollahi, Kamal; Moeslund, Thomas B.

    2017-01-01

    -of-the-art, real-time object detection system You Only Look Once, (YOLO) on the public LISA Traffic Light dataset available through the VIVA-challenge, which contain a high number of annotated traffic lights, captured in varying light and weather conditions. The YOLO object detector achieves an AUC of impres...

  9. Ipotesi : l'universo come "membrana"

    CERN Multimedia

    Durante, Elisabetta

    2003-01-01

    The Deparment of Physics at the University "La Sapienza" of Roma awarded a prestigious prize to Lisa Randall from Harvard University for her research in the field of high energy physics: the model of the universe as a membrane - the idea of a universe (space-time) with many dimensions (1 page)

  10. Microkelvin thermal control system for the laser interferometer space antenna mission and beyond

    Science.gov (United States)

    Higuchi, Sei

    2009-10-01

    The Laser Interferometer Space Antenna (LISA) mission aims to detect directly gravitational waves from massive black holes and galactic binaries. Through detecting gravitational waves, we can study blackholes and the origin of the universe, which is inaccessible from the electromagnetic wave spectrum. It will open a new window to the universe. LISA is essentially a Michelson interferometer placed in space with a third spacecraft added. Gravitational waves are time-varying strain in space-time, which is detectable as a fractional change in a proper distance. LISA will monitor fractional changes in the interferometer arms of a nominally 5 million km. The fractional change in the arm length can be as small as 1 x 10-21 m/(m · Hz ) even for powerful sources. LISA makes use of the gravitational reference sensors (GRS) for drag-free control and will achieve the required sensitivity through management of specific acceleration noise. The total acceleration disturbance to each proof mass, which floats at the center of each GRS, is required to be below 3 x 10-15 m/(s2 · Hz ). Thermal variations due to, for example, solar irradiation, or temperature gradients across the proof mass housing, are expected to be significant disturbance source to the LISA sensitivity requirements. Even a small temperature gradient can produce distortions in the housing structure, which results in a mass attraction force. In this thesis, I focus on developing a thermal control system that aims to achieve the temperature stability of 10 muK / Hz over 0.1 mHz to 1 Hz. We have chosen glass-bead thermistors as the temperature sensor for feedback temperature control of the GRS. First, we created a temperature sensor design program in MATLAB that provides an optimal values of resistances in the thermistor bridge circuit for the given application. The spectral stability of the sensor achieves as low as 20 muK/ Hz at 1 mHz with a DC excitation source. The LISA thermal requirement is met by employing AC

  11. Kuidas sertifitseerida kaupa, mis läheb Venemaale / Enno Aloe

    Index Scriptorium Estoniae

    Aloe, Enno

    1995-01-01

    Kommentaarid kohustuslikule sertifitseerimisele kuuluva Venemaale sisseveetava kauba sertifitseerimise kohta. Kinnitatud 15. sep. 1994. a., jõustunud 1. okt. 1994. a.; Lisa 1: Kohustuslikult sertifitseerimisele kuuluvate kaupade ja teenuste nimistu; Lisa 3: Rahvusvahelised sertifitseerimissüsteemid, millega Venemaa on ühinenud. Tõlkeallikas: Pravo i Ekonomika, 1994, Nr. 35

  12. Päästke mööbel! / Marko Rillo

    Index Scriptorium Estoniae

    Rillo, Marko

    2006-01-01

    Näide üle-eestilise juhtimiskonkursi "Juhtimisaju 2006" ühest ülesandest ning võistkonna "Mõistuse hääl" probleemilahendus. Lisa: Ülesanne; Vt. samas: Kas tankis põlenud poiste aeg pole mitte läbi? Lisa: Teinto Furniture'i SWOT analüüs

  13. Arm locking with Doppler estimation errors

    Energy Technology Data Exchange (ETDEWEB)

    Yu Yinan; Wand, Vinzenz; Mitryk, Shawn; Mueller, Guido, E-mail: yinan@phys.ufl.ed [Department of Physics, University of Florida, Gainesville, FL 32611 (United States)

    2010-05-01

    At the University of Florida we developed the University of Florida LISA Interferometer Simulator (UFLIS) in order to study LISA interferometry with hardware in the loop at a system level. One of the proposed laser frequency stabilization techniques in LISA is arm locking. Arm locking uses an adequately filtered linear combination of the LISA arm signals as a frequency reference. We will report about experiments in which we demonstrated arm locking using UFLIS. During these experiments we also discovered a problem associated with the Doppler shift of the return beam. The initial arm locking publications assumed that this Doppler shift can perfectly be subtracted inside the phasemeter or adds an insignificant offset to the sensor signal. However, the remaining Doppler knowledge error will cause a constant change in the laser frequency if unaccounted for. Several ways to circumvent this problem have been identified. We performed detailed simulations and started preliminary experiments to verify the performance of the proposed new controller designs.

  14. Technology Development Roadmap: A Technology Development Roadmap for a Future Gravitational Wave Mission

    Science.gov (United States)

    Camp, Jordan; Conklin, John; Livas, Jeffrey; Klipstein, William; McKenzie, Kirk; Mueller, Guido; Mueller, Juergen; Thorpe, James Ira; Arsenovic, Peter; Baker, John; hide

    2013-01-01

    Humankind will detect the first gravitational wave (GW) signals from the Universe in the current decade using ground-based detectors. But the richest trove of astrophysical information lies at lower frequencies in the spectrum only accessible from space. Signals are expected from merging massive black holes throughout cosmic history, from compact stellar remnants orbiting central galactic engines from thousands of close contact binary systems in the Milky Way, and possibly from exotic sources, some not yet imagined. These signals carry essential information not available from electromagnetic observations, and which can be extracted with extraordinary accuracy. For 20 years, NASA, the European Space Agency (ESA), and an international research community have put considerable effort into developing concepts and technologies for a GW mission. Both the 2000 and 2010 decadal surveys endorsed the science and mission concept of the Laser Interferometer Space Antenna (LISA). A partnership of the two agencies defined and analyzed the concept for a decade. The agencies partnered on LISA Pathfinder (LPF), and ESA-led technology demonstration mission, now preparing for a 2015 launch. Extensive technology development has been carried out on the ground. Currently, the evolved Laser Interferometer Space Antenna (eLISA) concept, a LISA-like concept with only two measurement arms, is competing for ESA's L2 opportunity. NASA's Astrophysics Division seeks to be a junior partner if eLISA is selected. If eLISA is not selected, then a LISA-like mission will be a strong contender in the 2020 decadal survey. This Technology Development Roadmap (TDR) builds on the LISA concept development, the LPF technology development, and the U.S. and European ground-based technology development. The eLISA architecture and the architecture of the Mid-sized Space-based Gravitational-wave Observatory (SGO Mid)-a competitive design with three measurement arms from the recent design study for a NASA

  15. Gravitational wave radiation from a double white dwarf system inside our galaxy: a potential method for seeking strange dwarfs

    Institute of Scientific and Technical Information of China (English)

    Zhan-Kui Lü; Shi-Wei Wu; Zhi-Cheng Zeng

    2009-01-01

    Like the investigation of double white dwarf (DWD) systems, strange dwarf (SD) - white dwarf (WD) system evolution in Laser Interferometer Space Antenna (LISA)'s absolute amplitude-frequency diagram is investigated. Since there is a strange quark core inside an SD, SDs' radii are significantly smaller than the value predicted by the standard WD model, which may strongly affect the gravitational wave (GW) signal in the mass-transferring phases of binary systems. We study how an SD-WD binary evolves across LISA's absolute amplitude-frequency diagram. In principle, we provide an executable way to detect SDs in the Galaxy's DWD systems by radically new windows offered by GW detectors.

  16. Rüdiger von der Goltzi ja Ludvig Jakobseni kohtumine 1938. aastal / [eessõna autor Agur Benno] / eessõna autor Benno Agur

    Index Scriptorium Estoniae

    2007-01-01

    21. detsembril 1938 kohtusid Berliinis Eesti sõjaväeata̧ee kolonel Ludvig Karl Jakobsen ning riigisakslasest kindral krahv Rüdiger von der Goltz. Kirjalik dokument sellest kohtumisest jõudis kindral Johan Laidonerini, kes lisas sellel oma kommentaari. Arutlusteemaks olid 1919. aasta sündmused. - Lisa: Johann Laidoneri kommentaar

  17. Extremely stable piezo mechanisms for the New Gravitational Wave Observatory

    NARCIS (Netherlands)

    Pijnenburg, J.A.C.M.; Rijnveld, N.; Hogenhuis, H.

    2012-01-01

    Detection and observation of gravitational waves requires extreme stability in the frequency range 3e-5 Hz to 1 Hz. NGO/LISA will attain this by creating a giant interferometer in space, based on free floating proof masses in three spacecrafts. To operate NGO/LISA, the following piezo mechanisms are

  18. Fruitone CPA para retardar la maduración en piña Ananas comosus (L. Merr., cv. Cayena Lisa, cosechada en primavera Fruitone CPA for delay the fruit maturity of pineapple Ananas comosus (L Merr. cv. Smooth Cayenne harvested in spring time

    Directory of Open Access Journals (Sweden)

    ANDRÉS REBOLLEDO-MARTÍNEZ

    2002-08-01

    Full Text Available El objetivo fue determinar el efecto de dosis y número de aplicaciones de Fruitone CPA (ácido 2-3 clorofenoxi-propiónico en el retraso de la maduración, rendimiento y calidad del fruto de piña en el periodo de primavera. El experimento se llevó al cabo en el Campo Experimental Papaloapan, del INIFAP, en Veracruz, México. Se estableció con el cv. Cayena Lisa de México, en un diseño de bloques al azar con cuatro repeticiones; los tratamientos fueron nueve, incluido el testigo sin aplicación, 300, 600, 900 y 1200 mL por hectárea en una aplicación y 600, 900, 1500 y 2100 mL por hectárea divididas en dos aplicaciones iguales, espaciadas ocho días, de Fruitone CPA; los tratamientos se establecieron a los 135 días después de la inducción floral, a 65 días antes de la cosecha del testigo. Los resultados muestran un alto y significativo efecto del Fruitone en el peso de la fruta, aunque no hubo diferencias entre el número de aplicaciones; el contenido de ácido cítrico y los sólidos solubles totales se incrementaron con la aplicación del Fruitone. No se presentaron frutos agrietados ni con Mancha Café interna en ningún tratamiento. El retraso de la cosecha con respecto al testigo varió desde los seis hasta los 21 días, en función de la dosis. Se concluye que el mejor tratamiento fue el de 900 mL de Fruitone CPA por hectárea, en una sola aplicación, el cual incrementó el peso del fruto en un 14% y retrasó la cosecha 19 días.The objective of this research was to evaluate the effect of rates and applications of Fruitone CPA (acid 2-3 clorofenoxi -propionic over maturity delay, yield and quality of the pineapple fruit in spring time. The experiment was carried out in the Campo Experimental Papaloapan (INIFAP, in Veracruz State, Mexico. It was established with the cv. Smooth Cayenne, in randomized blocks, design with four replicates; totalizing nine treatments including, the control: 300, 600, 900 and 1200 mL of Fruitone CPA

  19. A COMPREHENSIVE STUDY OF CLOSE DOUBLE WHITE DWARFS AS GRAVITATIONAL WAVE SOURCES: EVOLUTIONARY CHANNELS, BIRTH RATES, AND PHYSICAL PROPERTIES

    International Nuclear Information System (INIS)

    Liu Jinzhong; Han Zhanwen; Zhang Fenghui; Zhang Yu

    2010-01-01

    Close double white dwarfs (CDWDs) are believed to dominate the Galactic gravitational wave (GW) radiation in the frequency range 10 -4 to 0.1 Hz, which will be detected by the Laser Interferometer Space Antenna (LISA) detector. The aim of this detector is to detect GW radiation from astrophysical sources in the universe and to help improve our understanding of the origin of the sources and their physical properties (masses and orbital periods). In this paper, we study the probable candidate sources in the Galaxy for the LISA detector: CDWDs. We use the binary population synthesis approach of CDWDs together with the latest findings of the synthesis models from Han, who proposed three evolutionary channels: (1) stable Roche lobe overflow plus common envelope (RLOF+CE), (2) CE+CE, and (3) exposed core plus CE. As a result, we systematically investigate the detailed physical properties (the distributions of masses, orbital periods, and chirp masses) of the CDWD sources for the LISA detector, examine the importance of the three evolutionary channels for the formation of CDWDs, and carry out Monte Carlo simulations. Our results show that RLOF+CE and CE+CE are the main evolutionary scenarios leading to the formation of CDWDs. For the LISA detectable sources, we also explore and discuss the importance of these three evolutionary channels. Using the calculated birth rate, we compare our results to the LISA sensitivity curve and the foreground noise floor of CDWDs. We find that our estimate for the number of CDWD sources that can be detected by the LISA detector is greater than 10,000. We also find that the detectable CDWDs are produced via the CE+CE channel and we analyze the fraction of the detectable CDWDs that are double helium (He+He), or carbon-oxygen plus helium (CO+He) WD binary systems.

  20. EDITORIAL: Proceedings of the 12th Gravitational Wave Data Analysis Workshop (GWDAW 12), Cambridge, MA, USA, 13 16 December 2007

    Science.gov (United States)

    Hughes, S.; Katsavounidis, E.

    2008-09-01

    It was a great pleasure and an honor for us to host the 12th Gravitational Wave Data Analysis Workshop (GWDAW) at MIT and the LIGO Laboratory in Cambridge, Massachusetts, the place where this workshop series started in 1996. This time the conference was held at the conference facilities of the Royal Sonesta Hotel in Cambridge from 13 16 December, 2007. This 12th GWDAW found us with the ground interferometers having just completed their most sensitive search for gravitational waves and as they were starting their preparation to bring online and/or propose more sensitive instruments. Resonant mass detectors continued to observe the gravitational wave sky with instruments that have been operating now for many years. LISA, the Laser Interferometer Space Antenna, was recently reviewed by NASA's Beyond Einstein Program Assessment Committee (BEPAC) convened by the National Research Council (NRC) and found that 'on purely scientific grounds LISA is the mission that is the most promising and least scientifically risky…thus, the committee gave LISA its highest scientific ranking'. Even so, JDEM, the Joint Dark Energy Mission, was identified to go first, with LISA following a few years after. New methods, analysis ideas, results from the analysis of data collected by the instruments, as well as Mock Data Challenges for LISA were reported in this conference. While data from the most recent runs of the instruments are still being analyzed, the first upper limit results show how even non-detection statements can be interesting astrophysics. Beyond these traditional aspects of GWDAW though, for the first time in this workshop we tried to bring the non-gravitational wave physics and astronomy community on board in order to present, discuss and propose ways to work together as we pursue the first detection of gravitational waves and as we hope to transition to gravitational wave astronomy in the near future. Overview talks by colleagues leading observations in the electromagnetic

  1. Availability of Communications for the NATO Air Command and Control System in the Central Region and 5ATAF

    Science.gov (United States)

    1991-10-01

    Ground LINKI LISA (Note 1) LISA Environment Data LINK 3 (also supporting mission (single multi- Unks LINK 6 management, ontrol, functional LINK 7 status...LINK 7 status reports, C2RM, message MBDL and sensors) catalogue) ATDL-1 ATDL-1 (Note 2) LINK 11B (Note 3) LINKI 1B ACCS Ground- LINK 4 (interim Air

  2. Supporting Young English Learners in the United States

    Science.gov (United States)

    Barrow, Lisa; Markman-Pithers, Lisa

    2016-01-01

    Simply put, children with poor English skills are less likely to succeed in school and beyond. What's the best way to teach English to young children who aren't native English speakers? In this article, Lisa Barrow and Lisa Markman-Pithers examine the state of English learner education in the United States and review the evidence behind different…

  3. An experiment to test in-field pointing for Elisa

    Science.gov (United States)

    Brugger, Christina; Broll, Bernhard; Fitzsimons, Ewan; Johann, Ulrich; Jonke, Wouter; Lucarelli, Stefano; Nikolov, Susanne; Voert, Martijn; Weise, Dennis; Witvoet, Gert

    2017-11-01

    The evolved Laser Interferometer Space Antenna (eLISA) Mission is being developed to detect and characterise gravitational waves by measuring pathlength changes between free flying inertial test masses over a baseline of order 1 Gm. Here the observed astrophysical events and objects lie in a frequency range between 30 μHz and 1 Hz (the LISA measurement band, LMB).

  4. Pankrotis riik ja valusad reformid kärbivad Sarkozy senist tähelendu / Triin Oppi, Karin Volmer

    Index Scriptorium Estoniae

    Oppi, Triin

    2007-01-01

    Ilmunud ka: Postimees : na russkom jazõke, 25. sept. 2007, lk. 7. Postimees : na russkom jazõke lüh. Prantsusmaa presidendi Nicolas Sarkozy plaanib riigi pankrotist väljatoomiseks mitmeid seadusemuudatusi ja uuendusi. Peaminister Francois Fillon tunnistas eelarvepuudujääki. Lisa: Toetus. Väljavõtteid ajakirjale Time antud hinnangutest Nicolas Sarkozy valitsusajale: Philip H. Gordon, Marielle de Sarnez, Dominique Moisi

  5. Litvinenko mõrva juurdlus ootab Moskva uut luba / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2007-01-01

    Aleksandr Litvinenko mõrva uurijad Suurbritannias soovivad uuesti Venemaale pääseda, Venemaa pole veel ametlikku vastust andnud. Suurbritannia on tagasi lükanud Moskva ettepaneku, et vastutasuks võiksid Vene kohtuvõimu esindajad Londonis üle kuulata Boriss Berezovski ja Ahmed Zakajevi. Mehest, keda ajalehe Times andmeil kahtlustatakse Litvinenko mürgitamises. Lisa: Berezovski jälitamine peatati

  6. Plasma heating by radio frequency in the LISA linear machine

    International Nuclear Information System (INIS)

    Cunha Raposo, C. da.

    1985-05-01

    The characteristics of an experimental apparatus to produce helium plasma by radio frequency and to study its behavior when confined by a magnetic field with mirrors is shown. The plasma was produced by a microwave source of 2.45 GHz and 800 Watts, operating in steady and pulsed state. The plasma parameters were studied as a function of an external magnetic field, for large and small resonance regions. The axial and radial magnetic fields were mapped for each region in order to verify the spatial distribution, particle orbits, and energy confinement time according to the energy balance equation. As a consequence of the influence of the radio frequency (RF) voltage in the plasma the Bohm theory of plasma prob was modified. The diagnostic was done with plane movable electrostatic probe, Hall probe, magnetic probe, diamagnetic coil and spectrography. (Author) [pt

  7. Samm efektiivsuse poole - väärtusahela kaardistamine / Aleksandr Miina

    Index Scriptorium Estoniae

    Miina, Aleksandr, 1979-

    2007-01-01

    Ilmunud ka: Delovõje Vedomosti : Promõshlennost 20. veebr. 2008 lk. 7. Väärtusahela kaardistamine on kulusäästliku tootmise meetod, mis koosneb kahest etapist. Esmalt luuakse ettevõtte hetkeseisu kaart (Present State Map), mille analüüsi tulemusena kujundatakse tulevikuseisu kaart (Future State Map). Lisa: Väärtusahela kaardistamine; Asjaolud, mis ei lisa tootmisprotsessi väärtust

  8. 2010 CERT Research Report

    Science.gov (United States)

    2011-09-01

    extensive and expensive rework before implementation. Analysis of catastrophe helps us to see how complex, multi-system, multi-organizational...Cyber Security Science of Cyber Security, published by JASON , an independent scientific advisory group that provides consulting services to the U.S...Ed Desautels Lisa Gardner Alexa Huth Mindi McDowell Amanda Parente Pennie Walters Contributing Team Members Michelle Fried Lisa Marino Design David

  9. A Report to the President: Analytic Perspectives on the Science and Technology Issues Facing the Nation

    Science.gov (United States)

    2001-01-01

    Initiatives CAROLINE WAGNER Research Planning and OSTP Coordination LISA SHELDONE Research Administration and Financial Management DAVID ADAMSON...Communications LISA NEUFELD Contract Administration and Financial Management REVIEWS FROM S&T POLICY INSTITUTE PROJECT SPONSORS “The Science & Technology Policy...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Science and Technology Policy Instituite , RAND, 1200 South Hayes St

  10. Fascioliasis risk factors and space-time clusters in domestic ruminants in Bangladesh.

    Science.gov (United States)

    Rahman, A K M Anisur; Islam, S K Shaheenur; Talukder, Md Hasanuzzaman; Hassan, Md Kumrul; Dhand, Navneet K; Ward, Michael P

    2017-05-08

    A retrospective observational study was conducted to identify fascioliasis hotspots, clusters, potential risk factors and to map fascioliasis risk in domestic ruminants in Bangladesh. Cases of fascioliasis in cattle, buffalo, sheep and goats from all districts in Bangladesh between 2011 and 2013 were identified via secondary surveillance data from the Department of Livestock Services' Epidemiology Unit. From each case report, date of report, species affected and district data were extracted. The total number of domestic ruminants in each district was used to calculate fascioliasis cases per ten thousand animals at risk per district, and this was used for cluster and hotspot analysis. Clustering was assessed with Moran's spatial autocorrelation statistic, hotspots with the local indicator of spatial association (LISA) statistic and space-time clusters with the scan statistic (Poisson model). The association between district fascioliasis prevalence and climate (temperature, precipitation), elevation, land cover and water bodies was investigated using a spatial regression model. A total of 1,723,971 cases of fascioliasis were reported in the three-year study period in cattle (1,164,560), goats (424,314), buffalo (88,924) and sheep (46,173). A total of nine hotspots were identified; one of these persisted in each of the three years. Only two local clusters were found. Five space-time clusters located within 22 districts were also identified. Annual risk maps of fascioliasis cases correlated with the hotspots and clusters detected. Cultivated and managed (P fascioliasis in Bangladesh, respectively. Results indicate that due to land use characteristics some areas of Bangladesh are at greater risk of fascioliasis. The potential risk factors, hot spots and clusters identified in this study can be used to guide science-based treatment and control decisions for fascioliasis in Bangladesh and in other similar geo-climatic zones throughout the world.

  11. Detecting a stochastic gravitational wave background with the Laser Interferometer Space Antenna

    International Nuclear Information System (INIS)

    Cornish, Neil J.

    2002-01-01

    The random superposition of many weak sources will produce a stochastic background of gravitational waves that may dominate the response of the LISA (Laser Interferometer Space Antenna) gravitational wave observatory. Unless something can be done to distinguish between a stochastic background and detector noise, the two will combine to form an effective noise floor for the detector. Two methods have been proposed to solve this problem. The first is to cross-correlate the output of two independent interferometers. The second is an ingenious scheme for monitoring the instrument noise by operating LISA as a Sagnac interferometer. Here we derive the optimal orbital alignment for cross-correlating a pair of LISA detectors, and provide the first analytic derivation of the Sagnac sensitivity curve

  12. Mullet fry (Mugilidae in coastal waters of Montenegro, their spatial distribution and migration phenology

    Directory of Open Access Journals (Sweden)

    Mićković B.

    2010-01-01

    Full Text Available Three localities, representing three distinct coastal areas, were investigated: 1. the mouth of the Sutorina River; 2. the mouth of the Jaška River; 3. the mouth of the Bojana River (right branch. Regarding the composition of young mullet assemblages, Lisa saliens, Lisa ramada and Lisa aurata were dominant at the first locality; L. aurata and Chelon labrosus at the second; and at the third L. ramada was clearly dominant, Mugil cephalus occupied the subdominant position, while L. aurata was absent. The seasons of the first appearance of migratory fry were October, April, November, October and July, for M. cephalus, C. labrosus, L. ramada, L. aurata and L. saliens, respectively. Migratory periods varied from 2 (C. labrosus to 7 (L. ramada months.

  13. Improved optical ranging for space based gravitational wave detection

    International Nuclear Information System (INIS)

    Sutton, Andrew J; Shaddock, Daniel A; McKenzie, Kirk; Ware, Brent; De Vine, Glenn; Spero, Robert E; Klipstein, W

    2013-01-01

    The operation of 10 6  km scale laser interferometers in space will permit the detection of gravitational waves at previously unaccessible frequency regions. Multi-spacecraft missions, such as the Laser Interferometer Space Antenna (LISA), will use time delay interferometry to suppress the otherwise dominant laser frequency noise from their measurements. This is accomplished by performing sub-sample interpolation of the optical phase measurements recorded at each spacecraft for synchronization and cancellation of the otherwise dominant laser frequency noise. These sub-sample interpolation time shifts are dependent upon the inter-spacecraft range and will be measured using a pseudo-random noise ranging modulation upon the science laser. One limit to the ranging performance is mutual interference between the outgoing and incoming ranging signals upon each spacecraft. This paper reports on the demonstration of a noise cancellation algorithm which is shown to providing a factor of ∼8 suppression of the mutual interference noise. Demonstration of the algorithm in an optical test bed showed an rms ranging error of 0.06 m, improved from 0.19 m in previous results, surpassing the 1 m RMS LISA specification and potentially improving the cancellation of laser frequency noise. (paper)

  14. A Michelson interferometer system for testing the stability of a piezo-electric actuator intended for use in space

    International Nuclear Information System (INIS)

    Aplin, K L; Middleton, K F

    2007-01-01

    The Laser Interferometer Space Antenna (LISA) experiment will search for gravitational waves generated by cataclysmic events far back in astronomical history. LISA is an interferometer formed by three spacecraft positioned five million km apart, and to observe gravitational waves, it must monitor test mass positions with picometre level resolution. One of the numerous technological challenges is to identify an actuator with appropriate accuracy, precision and stability for positioning of the optical fibres used to deliver LISA's laser sources. We have developed a Michelson interferometer system to determine the temporal and thermal stability of candidate actuators, with an emphasis on characterisation in the milliHertz frequency range required for gravitational wave detection in space. This paper describes the interferometer data logging and calibration and presents preliminary results in the form of a 'noise spectrum' generated from the small perturbation of a nominally static mirror. The maximum displacement of the mirror was ∼50 nm with sub-Hz noise levels of 0.1-1 nm√Hz. This is within the LISA noise specification, and confirms that the apparatus is stable enough for the characterisation of the actuator

  15. Bayesian inference on EMRI signals using low frequency approximations

    International Nuclear Information System (INIS)

    Ali, Asad; Meyer, Renate; Christensen, Nelson; Röver, Christian

    2012-01-01

    Extreme mass ratio inspirals (EMRIs) are thought to be one of the most exciting gravitational wave sources to be detected with LISA. Due to their complicated nature and weak amplitudes the detection and parameter estimation of such sources is a challenging task. In this paper we present a statistical methodology based on Bayesian inference in which the estimation of parameters is carried out by advanced Markov chain Monte Carlo (MCMC) algorithms such as parallel tempering MCMC. We analysed high and medium mass EMRI systems that fall well inside the low frequency range of LISA. In the context of the Mock LISA Data Challenges, our investigation and results are also the first instance in which a fully Markovian algorithm is applied for EMRI searches. Results show that our algorithm worked well in recovering EMRI signals from different (simulated) LISA data sets having single and multiple EMRI sources and holds great promise for posterior computation under more realistic conditions. The search and estimation methods presented in this paper are general in their nature, and can be applied in any other scenario such as AdLIGO, AdVIRGO and Einstein Telescope with their respective response functions. (paper)

  16. Nanostructure Secondary-Mirror Apodizing Mask for Transmitter Signal Suppression in a Duplex Telescope

    Science.gov (United States)

    Hagopian, John; Livas, Jeffrey; Shiri, Shahram; Getty, Stephanie; Tveekrem, June; Butler, James

    2012-01-01

    A document discusses a nanostructure apodizing mask, made of multi-walled carbon nanotubes, that is applied to the centers (or in and around the holes) of the secondary mirrors of telescopes that are used to interferometrically measure the strain of space-time in response to gravitational waves. The shape of this ultra-black mask can be adjusted to provide a smooth transition to the clear aperture of the secondary mirror to minimize diffracted light. Carbon nanotubes grown on silicon are a viable telescope mirror substrate, and can absorb significantly more light than other black treatments. The hemispherical reflectance of multi-walled carbon nanotubes grown at GSFC is approximately 3 to 10 times better than a standard aerospace paint used for stray light control. At the LISA (Laser Interferometer Space Antenna) wavelength of 1 micron, the advantage over paint is a factor of 10. Primarily, in the center of the secondary mirror (in the region of central obscuration, where no received light is lost) a black mask is applied to absorb transmitted light that could be reflected back into the receiver. In the LISA telescope, this is in the center couple of millimeters. The shape of this absorber is critical to suppress diffraction at the edge. By using the correct shape, the stray light can be reduced by approximately 10 to the 9 orders of magnitude versus no center mask. The effect of the nanotubes has been simulated in a stray-light model. The effect of the apodizing mask has been simulated in a near-field diffraction model. Specifications are geometry-dependent, but the baseline design for the LISA telescope has been modeled as well. The coatings are somewhat fragile, but work is continuing to enhance adhesion.

  17. Surm päästis Milosevici kohtuotsusest / Arko Olesk

    Index Scriptorium Estoniae

    Olesk, Arko, 1981-

    2006-01-01

    Vt. ka Postimees : na russkom jazõke 14. märts lk. 11. 11. märtsil suri Jugoslaavia endine president Slobodan Milosevic, ekspresidendi surma põhjus selgub lahkamisel. Lisa: Presidendist sõjakohtu ette. Lisa: Arvamust avaldavad ÜRO sõjakuritegude tribunali peasüüdistaja Carla del Ponte, Serbia Sotsialistliku Partei esimees Ivica Dacic ja Suurbritannia välisminister Jack Straw. Kaart: Balkani sõjad

  18. Terrorihirmus USA võimud jälgisid pangatehinguid / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2006-01-01

    New York Times esitatud andmete kohaselt on president Bushi administratsioon neli ja pool aastat rahvusvahelise pangandustehinguid koordineeriva organisatsiooni SWIFT vahendusel kontrollinud riigi elanike rahvusvahelisi pangatehinguid. Mitmete kolumnistide arvates on eraelu puutumatuse põhimõttega mindud vastuollu. President Bushi administratsioon kinnitas, et jälitustegevus oli vajalik USA julgeoleku tagamiseks. Lisa: USA jälgib. Vt. samas: Iraagi mässulised ähvardavad Briti sõdurite peresid

  19. Thermal diagnostic of the optical window on board LISA Pathfinder

    International Nuclear Information System (INIS)

    Nofrarias, M; MarIn, A F GarcIa; Lobo, A; Heinzel, G; Ramos-Castro, J; Sanjuan, J; Danzmann, K

    2007-01-01

    Vacuum conditions inside the LTP gravitational reference sensor must be under 10 -5 Pa, a rather demanding requirement. The optical window (OW) is an interface which seals the vacuum enclosure and, at the same time, lets the laser beam go through for interferometric metrology with the test masses. The OW is a plane-parallel plate clamped in a titanium flange, and is considerably sensitive to thermal and stress fluctuations. It is critical for the required precision measurements, hence its temperature will be carefully monitored in flight. This paper reports on the results of a series of OW characterization laboratory runs, intended to study its response to selected thermal signals, as well as their fit to numerical models, and the meaning of the latter. We find that a single-pole ARMA transfer function provides a consistent approximation to the OW response to thermal excitations, and derive a relationship with the physical processes taking place in the OW. We also show how the system noise reduction can be accomplished by means of that transfer function

  20. Töölepingu alusel Eesti NSV ettevõtetes töötavate töötajate töötasustamise aluste kohta

    Index Scriptorium Estoniae

    1990-01-01

    Lisa: töölepingu alusel EV ettevõtetes töötavate tööliste tunnitasude alammäärad lk. 52. Lisa nr. 2: Töölepingute alusel ENSV ettevõtetes töötavate töötajate ametipalkade alammäärad (ENSV ÜVT 1990 nr. 5 art. 91). Muudatused: RT I 1991 nr. 25 art. 314 - lisad 1 ja 2 kehtetud

  1. The French Hy-Bird flies on solar energy and hydrogen; De Franse Hy-Bird vliegt op zon en waterstof

    Energy Technology Data Exchange (ETDEWEB)

    Van Zutphen, E. [Service pour la Science et la Technologie, Ambassade du Royaume des Pays-Bas, Paris (France)

    2009-05-15

    French airplane manufacturer LISA Airplanes is working on the development of a two-person airplane that flies on a combination of solar energy and a fuel cell: the Hy-Bird. In 2008, LISA entered into a collaboration agreement with the Chinese solar cell manufacturer TrinaSolar. This agreement was recently expanded. The large advantage of the Hy-Bird: flying noiselessly and without local CO2 emission. An existing recreational airplane of own design was used as a basis, which is known for its energy efficiency and streamlining: the Akoya. Next, the airplane was equipped with a fuel; cell made of composites and the wings were covered with solar cells. (mk) [Dutch] De Franse vliegtuigbouwer LISA Airplanes werkt aan de ontwikkeling van een tweepersoons vliegtuig dat vliegt op een combinatie van zonne-energie en een brandstofcel: de Hy-Bird. In 2008 ging LISA een samenwerkingsverband aan met de Chinese zonnecelproducent TrinaSolar. Deze overeenkomst is onlangs uitgebreid. Het grote voordeel van de Hy-Bird: geluidarm vliegen zonder lokale CO2-uitstoot. Als basis dient een bestaand recreatievliegtuig van eigen ontwerp, bekend om zijn energiezuinigheid en stroomlijning: de Akoya. Vervolgens is het vliegtuig uitgerust met een brandstofcel gemaakt van composieten toe, en zijn de vleugels bekleed met zonnecellen.

  2. Survey shows large differences between the Nordic countries in the use of less invasive surfactant administration

    DEFF Research Database (Denmark)

    Jonsson, Baldvin; Andersson, Sture; Björklund, Lars J

    2017-01-01

    AIM: Less invasive surfactant administration (LISA), namely surfactant instillation through a thin catheter in the trachea during spontaneous breathing, is increasingly used for premature infants. We surveyed the use of this technique in the Nordic countries in autumn 2015. METHODS: A link to a web......-based survey of surfactant administration methods was emailed to the directors of all neonatal units in the Nordic Region, apart from Finland, where only the five university-based departments were invited. RESULTS: Of the 73 units (85%) who responded, 23 (32%) said that they used LISA. The country rates were......%. The main reasons for not using LISA were lack of familiarity with the technique (61%), no perceived benefit over other methods (22%) and concerns about patient discomfort (26%). CONCLUSION: Less invasive surfactant administration was used in 32% of Nordic neonatal units, most commonly in level three units...

  3. Uus plaat

    Index Scriptorium Estoniae

    2004-01-01

    Uutest plaatidest Helloween "Rabbit Don't Come Easy", David Byrne "grown Backwards", Joss Stone "The Soul Session", Bass boom 3 "Faster Harder Louder", Lisa Miskovsky "Fallingwater", Paco de Lucia "Cositas Buenos", Soundtrack "Once Upon A Time In Mexico", Vanilla Ninja "Don't Go Too Fast", Novaspace "Cubes", "Elmari tantsuõhtu 4.", The Von Bondies "Pawn Snappe Heart", Godsmack "The Other Side", George Michael "Patience", Eric Clapton "Me and Mr Johnson"

  4. The Troubled Relationship Between Israel and the European Union: An Empirical Explanation

    Science.gov (United States)

    2015-03-01

    9780199219322.003.0011. 62 Mearsheimer, “False Promise of International Institutions,” 18. 63 Robert O. Keohane and Lisa L. Martin, “The Promise of...Strategy in International Politics. New York: I. B. Taurus, 2013. Keohane , Robert O., and Lisa L. Martin. “The Promise of Institutionalist Theory...Rynning, “Common Security and Defense Policy,” 27; Robert J. Art, Stephen G. Brooks, William C. Wohlforth, Keir A. Lieber and Gerard Alexander

  5. KORMILITSA LISA - NEW GREEK-RUSSIAN INTEGRATED SUSTAINABLE WHITE BERRY MOSCHATUS GRAPE VARIETY Кормилица Лиза – новый Греко-Российский комплексноустойчивый белоягодный мускатный сорт винограда

    OpenAIRE

    Zamanidi P. C.; Troshin L. P.

    2013-01-01

    Kormilitsa Lisa grape was created in Greece by P. Zamanidi and L.Troshin in 2003 with crossing the varieties of the Pervenets Maharach with varieties of Muscat white. The duration of the production period is 146-155 days. The yield is high. The average mass of clusters of 250 g. It has winter hardiness, drought-resistance and high resistance to fungal diseases in comparison with varieties of Vitis vinifera; it is also tolerant to phylloxeras. The flower is ambisexual. The bunch is average, cy...

  6. Multi-Axis Heterodyne Interferometry (MAHI)

    Science.gov (United States)

    Thorpe, James

    The detection and measurement of gravitational waves represents humanity’s next, and final, opportunity to open an entirely new spectrum with which to view the universe. The first steps of this process will likely take place later this decade when the second-generation ground-based instruments such as Advanced LIGO approach design sensitivity. While these events will be historic, it will take a space-based detector to access the milliHertz gravitational wave frequency band, a band that is rich in both number and variety of sources. The Laser Interferometer Space Antenna (LISA) concept has been developed over the past two decades in the US and Europe to provide access to this band. The European Space Agency recently selected The Gravitational Universe as the science theme for the 3rd Large-class mission in the Cosmic Visions Programme, with the assumption that a LISA-like instrument would be implemented for launch in 2034. NASA has expressed interest in partnering on this effort and the US community has made its own judgment on the scientific potential of a space-based gravitational wave observatory through the selection of LISA as the 3rd flagship mission in the 2010 Decadal Survey. Much of the effort has been in retiring risk for the unique technologies that comprise a gravitational wave detector. A prime focus of this effort is LISA Pathfinder (LPF), a dedicated technology demonstrator mission led by ESA with contributions from NASA and several member states. LPF’s primary objective is to validate drag-free flight as an approach to realizing an inertial reference mass. Along the way, several important technologies will be demonstrated, including picometer-level heterodyne interferometry. However, there are several important differences between the interferometry design for LISA and that for LPF. These mostly result from the fact that LISA interferometry involves multiple lasers on separate spacecraft whereas LPF can use a single laser on a single spacecraft

  7. Gravitational waves from self-ordering scalar fields

    International Nuclear Information System (INIS)

    Fenu, Elisa; Durrer, Ruth; Figueroa, Daniel G.; García-Bellido, Juan

    2009-01-01

    Gravitational waves were copiously produced in the early Universe whenever the processes taking place were sufficiently violent. The spectra of several of these gravitational wave backgrounds on subhorizon scales have been extensively studied in the literature. In this paper we analyze the shape and amplitude of the gravitational wave spectrum on scales which are superhorizon at the time of production. Such gravitational waves are expected from the self ordering of randomly oriented scalar fields which can be present during a thermal phase transition or during preheating after hybrid inflation. We find that, if the gravitational wave source acts only during a small fraction of the Hubble time, the gravitational wave spectrum at frequencies lower than the expansion rate at the time of production behaves as Ω GW (f) ∝ f 3 with an amplitude much too small to be observable by gravitational wave observatories like LIGO, LISA or BBO. On the other hand, if the source is active for a much longer time, until a given mode which is initially superhorizon (kη * 1, we find that the gravitational wave energy density is frequency independent, i.e. scale invariant. Moreover, its amplitude for a GUT scale scenario turns out to be within the range and sensitivity of BBO and marginally detectable by LIGO and LISA. This new gravitational wave background can compete with the one generated during inflation, and distinguishing both may require extra information

  8. Bolster Ground Force Capabilities in the Asia-Pacific Region

    Science.gov (United States)

    2016-05-12

    created them.” – Albert Einstein INTRODUCTION Following the collapse of the Soviet Union and the end of the Cold War in 1991, the United States...The Case for Archipelagic Defense,” 84. 37. Thomas Bickford, Lisa Hannett, Edward Skolnick, and Albert Willner, “The Role of the U.S. Army in...for Archipelagic Defense,” 84-85. 47. Thomas Bickford, Lisa Hannett, Edward Skolnick, and Albert Willner, “The Role of the U.S. Army in Asia

  9. Tony Blair ei saanud Balti riikidelt loodetud järeleandmisi / Andris Feldmanis

    Index Scriptorium Estoniae

    Feldmanis, Andris, 1982-

    2005-01-01

    Balti riigid ei olnud nõus loobuma kümnendikust eurotoetustest. Tallinnas viibinud Suurbritannia peaministri Tony Blairi väitel on EL-i uue finantsperspektiivi vastuvõtmine just uute liikmesriikide huvides. Vt. samas: Tiiu Laks. Riigijuhi visiit põhjustas Tallinnas vaid lühiajalisi liiklusseisakuid; Lisa: Blairi esinemine ei reetnud ebaedu; Kaivo Kopli. Uusliikmed andsid tuld juba enne ettepanekute saamist; Lisa: Toetus vanadelt liikmesmaadelt; Märt Kivine. EL-i eelarve: lahjem kui kunagi varem. Kommenteerib Taavi Veskimägi

  10. Prediction of trypsin/molecular fragment binding affinities by free energy decomposition and empirical scores

    Science.gov (United States)

    Benson, Mark L.; Faver, John C.; Ucisik, Melek N.; Dashti, Danial S.; Zheng, Zheng; Merz, Kenneth M.

    2012-05-01

    Two families of binding affinity estimation methodologies are described which were utilized in the SAMPL3 trypsin/fragment binding affinity challenge. The first is a free energy decomposition scheme based on a thermodynamic cycle, which included separate contributions from enthalpy and entropy of binding as well as a solvent contribution. Enthalpic contributions were estimated with PM6-DH2 semiempirical quantum mechanical interaction energies, which were modified with a statistical error correction procedure. Entropic contributions were estimated with the rigid-rotor harmonic approximation, and solvent contributions to the free energy were estimated with several different methods. The second general methodology is the empirical score LISA, which contains several physics-based terms trained with the large PDBBind database of protein/ligand complexes. Here we also introduce LISA+, an updated version of LISA which, prior to scoring, classifies systems into one of four classes based on a ligand's hydrophobicity and molecular weight. Each version of the two methodologies (a total of 11 methods) was trained against a compiled set of known trypsin binders available in the Protein Data Bank to yield scaling parameters for linear regression models. Both raw and scaled scores were submitted to SAMPL3. Variants of LISA showed relatively low absolute errors but also low correlation with experiment, while the free energy decomposition methods had modest success when scaling factors were included. Nonetheless, re-scaled LISA yielded the best predictions in the challenge in terms of RMS error, and six of these models placed in the top ten best predictions by RMS error. This work highlights some of the difficulties of predicting binding affinities of small molecular fragments to protein receptors as well as the benefit of using training data.

  11. Elisa technology consolidation study overview

    Science.gov (United States)

    Fitzsimons, E. D.; Brandt, N.; Johann, U.; Kemble, S.; Schulte, H.-R.; Weise, D.; Ziegler, T.

    2017-11-01

    The eLISA (evolved Laser Interferometer Space Antenna) mission is an ESA L3 concept mission intended to detect and characterise gravitational radiation emitted from astrophysical sources [1]. Current designs for eLISA [2] are based on the ESA study conducted in 2011 to reformulate the original ESA/NASA LISA concept [3] into an ESA-only L1 candidate named NGO (New Gravitational Observatory) [4]. During this brief reformulation period, a number of significant changes were made to the baseline LISA design in order to create a more costeffective mission. Some of the key changes implemented during this reformulation were: • A reduction in the inter satellite distance (the arm length) from 5 Gm to 1 Gm. • A reduction in the diameter of the telescope from 40 cm to 20 cm. • A reduction in the required laser power by approximately 40%. • Implementation of only 2 laser arms instead of 3. Many further simplifications were then enabled by these main design changes including the elimination of payload items in the two spacecraft (S/C) with no laser-link between them (the daughter S/C), a reduction in the size and complexity of the optical bench and the elimination of the Point Ahead Angle Mechanism (PAAM), which corrects for variations in the pointing direction to the far S/C caused by orbital dynamics [4] [5]. In the run-up to an L3 mission definition phase later in the decade, it is desirable to review these design choices and analyse the inter-dependencies and scaling between the key mission parameters with the goal of better understanding the parameter space and ensuring that in the final selection of the eLISA mission parameters the optimal balance between cost, complexity and science return can be achieved.

  12. Blink patterns and lid-contact times in dry-eye and normal subjects

    Directory of Open Access Journals (Sweden)

    Ousler GW 3rd

    2014-05-01

    Full Text Available George W Ousler 3rd,1 Mark B Abelson,1,2 Patrick R Johnston,1 John Rodriguez,1 Keith Lane,1 Lisa M Smith11Ora, Andover, MA, USA; 2Department of Ophthalmology, Harvard Medical School, Boston, MA, USAPurpose: To classify blinks in dry eye and normal subjects into six subtypes, and to define the blink rate and duration within each type of blink, as well as the total lid-contact time/minute.Materials and methods: This was a single-centered, prospective, double-blind study of eleven dry-eye and ten normal subjects. Predefined subjects watched a video while blinks were recorded for 10 minutes. Partial blinks were classified by percentage closure of maximal palpebral fissure opening: 25%, 50%, 75%. Complete blinks were characterized as full (>0 seconds, extended (>0.1 seconds, or superextended (>0.5 seconds. The mean duration of each type of blink was determined and standardized per minute as total lid-contact time.Results: Total blinks observed were 4,990 (1,414 normal, 3,756 dry eye: 1,809 (50.59% partial and 1,767 (49.41% complete blinks among dry-eye subjects versus 741 (52.90% partial and 673 (47.60% complete blinks among normal subjects. Only superextended blinks of ≥0.5-second duration were significantly more frequent in dry-eye subjects than normals (2.3% versus 0.2%, respectively; P=0.023. Total contact time was seven times higher in dry-eye subjects than normals (0.565 versus 0.080 seconds, respectively; P<0.001. Isolating only extended blinks (>0.1 second, the average contact time (seconds was four times longer in dry-eye versus normal subjects (2.459 in dry eye, 0.575 in normals; P=0.003. Isolating only superextended blinks (>0.5 seconds, average contact time was also significantly different (7.134 in dry eye, 1.589 in normals; P<0.001. The contact rate for all full closures was 6.4 times longer in dry-eye (0.045 versus 0.007, P<0.001 than normal subjects.Conclusion: Dry-eye subjects spent 4.5% of a

  13. Skills escalator in allied health: a time for reflection and refocus

    Directory of Open Access Journals (Sweden)

    Gilmore LG

    2011-09-01

    Full Text Available Lisa G Gilmore1, Joanne H Morris1, Karen Murphy2, Karen Grimmer-Somers3, Saravana Kumar31The Canberra Hospital, ACT Government Health Directorate, Canberra, ACT; 2ACT Government Health Directorate, Canberra, ACT; 3International Centre for Allied Evidence, University of South Australia, Adelaide, SA, AustraliaAbstract: It is abundantly clear that the health workforce of tomorrow will meet a number of unique challenges. There are a number of drivers for this, including the changing demographics of patients and health professionals, changing working patterns and mobility of the health workforce, evolving models of care, emerging evidence base, altering funding models, and the need to underpin health care service delivery with safety, effectiveness, patient centeredness, efficiency, equity, and timeliness. It is in this time of change that role extension within health disciplines is seen as an important tool to meet some of these challenges. Role extension is viewed as a skills escalator, where practitioners move up the skills escalator within the scope of their discipline, to advance it and then, with training, extend it. Within allied health, in some disciplines, advanced and extended scope of practice initiatives have mushroomed. Often these initiatives have been ad hoc, and opportunistically created in response to local needs and requirements. As these initiatives are local and context-dependent, to date there is very little uniformity or congruency between these initiatives. This has led to variability in implementation, lack of rigorous evaluations and, ultimately, poor long-term sustainability. In this paper, we reflect on a number of key issues, drawing on our own experiences in undertaking such initiatives, which need to be taken into account when considering advanced and extended scope of practice for allied health.Keywords: allied health, skill escalation, extended scope of practice, advanced scope of practice

  14. Optimal Aerodynamic Design of Conventional and Coaxial Helicopter Rotors in Hover and Forward Flight

    Science.gov (United States)

    2015-12-28

    graduate career a fun and (at times) productive pursuit. I owe a great deal to my parents , Kevin and Lisa, for their unconditional support. Finally...forward flight. Orchard and Newman [6] investigated fundamental design features of compound helicopters using a wing, a single rotor, and a propul- sor... style compound. For the case considered here, the coaxial rotors are unconstrained in lift offset. If a wing were used in a case that also included a lift

  15. Traffic Light Detection at Night

    DEFF Research Database (Denmark)

    Jensen, Morten Bornø; Philipsen, Mark Philip; Bahnsen, Chris

    2015-01-01

    Traffic light recognition (TLR) is an integral part of any in- telligent vehicle, it must function both at day and at night. However, the majority of TLR research is focused on day-time scenarios. In this paper we will focus on detection of traffic lights at night and evalu- ate the performance...... of three detectors based on heuristic models and one learning-based detector. Evaluation is done on night-time data from the public LISA Traffic Light Dataset. The learning-based detector out- performs the model-based detectors in both precision and recall. The learning-based detector achieves an average...

  16. Analysis of the elastic behaviour of nonclassical nonlinear mesoscopic materials in quasi-static experiments

    International Nuclear Information System (INIS)

    Ruffino, E.; Scalerandi, M.

    2000-01-01

    As discovered by recent quasi-static and dynamic resonance experiments, the classical nonlinear theory fails in describing the hysteretic behaviour of nonlinear mesoscopic materials like rocks, concrete, etc. The paper applies the local interaction simulation approach (LISA) for studying such kind of nonclassical nonlinearity. To this purpose, in the LISA treatment of ultrasonic wave propagation has been included a phenomenological model, based on the PM space approach, of the local mesoscopic features of rocks and other materials with localized damages. A quantitative comparison of simulation and experimental results in quasi-static experiments is also presented

  17. Gravitational waves from a very strong electroweak phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Leonardo; Mégevand, Ariel, E-mail: lleitao@mdp.edu.ar, E-mail: megevand@mdp.edu.ar [IFIMAR (UNMdP-CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales, UNMdP, Deán Funes 3350, (7600) Mar del Plata (Argentina)

    2016-05-01

    We investigate the production of a stochastic background of gravitational waves in the electroweak phase transition. We consider extensions of the Standard Model which can give very strongly first-order phase transitions, such that the transition fronts either propagate as detonations or run away. To compute the bubble wall velocity, we estimate the friction with the plasma and take into account the hydrodynamics. We track the development of the phase transition up to the percolation time, and we calculate the gravitational wave spectrum generated by bubble collisions, magnetohydrodynamic turbulence, and sound waves. For the kinds of models we consider, we find parameter regions for which the gravitational waves are potentially observable at the planned space-based interferometer eLISA. In such cases, the signal from sound waves is generally dominant, while that from bubble collisions is the least significant of them. Since the sound waves and turbulence mechanisms are diminished for runaway walls, the models with the best prospects of detection at eLISA are those which do not have such solutions. In particular, we find that heavy extra bosons provide stronger gravitational wave signals than tree-level terms.

  18. Detection strategies for extreme mass ratio inspirals

    International Nuclear Information System (INIS)

    Cornish, Neil J

    2011-01-01

    The capture of compact stellar remnants by galactic black holes provides a unique laboratory for exploring the near-horizon geometry of the Kerr spacetime, or possible departures from general relativity if the central cores prove not to be black holes. The gravitational radiation produced by these extreme mass ratio inspirals (EMRIs) encodes a detailed map of the black hole geometry, and the detection and characterization of these signals is a major scientific goal for the LISA mission. The waveforms produced are very complex, and the signals need to be coherently tracked for tens of thousands of cycles to produce a detection, making EMRI signals one of the most challenging data analysis problems in all of gravitational wave astronomy. Estimates for the number of templates required to perform an exhaustive grid-based matched-filter search for these signals are astronomically large, and far out of reach of current computational resources. Here I describe an alternative approach that employs a hybrid between genetic algorithms and Markov chain Monte Carlo techniques, along with several time-saving techniques for computing the likelihood function. This approach has proven effective at the blind extraction of relatively weak EMRI signals from simulated LISA data sets.

  19. This Is Getting a Little Too Chinese for Me’: The Representation of China in Crime Fiction Written in English

    Directory of Open Access Journals (Sweden)

    Isabel Santaulària i Capdevila

    2017-01-01

    Full Text Available The article addresses the representation of China in contemporary crime fiction written in English. A close examination of a selection of works set in China by Lisa See, Peter May, Catherine Sampson, Lisa Brackmann and Duncan Jepson reveals that, following the hardboiled tradition and crime fictions produced in post-colonial times, these narratives scrutinize the West’s many deficiencies. However, the authors do not articulate a truly postcolonial discourse aimed at destabilizing the notion of the assumed superiority of the West and its right to intrude in other countries’ affairs. Furthermore, these narratives seem to be written to confirm the readers’ worst expectations about China, which is fated to stay poor, backward and ultimately Other, unable to achieve some degree of ‘normalization’ or Westernization that could legitimize China’s claims to modernity, improvement and ascendancy in our global economy. Thus, as we vicariously travel the country through these narratives, we face the usual array of fraudsters, tricksters and blood-thirsty murderers that populate crime fictions, but it is China itself that is singled out as the true monster of the stories.

  20. A comparative analysis of hazard models for predicting debris flows in Madison County, VA

    Science.gov (United States)

    Morrissey, Meghan M.; Wieczorek, Gerald F.; Morgan, Benjamin A.

    2001-01-01

    During the rainstorm of June 27, 1995, roughly 330-750 mm of rain fell within a sixteen-hour period, initiating floods and over 600 debris flows in a small area (130 km2) of Madison County, Virginia. Field studies showed that the majority (70%) of these debris flows initiated with a thickness of 0.5 to 3.0 m in colluvium on slopes from 17 o to 41 o (Wieczorek et al., 2000). This paper evaluated and compared the approaches of SINMAP, LISA, and Iverson's (2000) transient response model for slope stability analysis by applying each model to the landslide data from Madison County. Of these three stability models, only Iverson's transient response model evaluated stability conditions as a function of time and depth. Iverson?s model would be the preferred method of the three models to evaluate landslide hazards on a regional scale in areas prone to rain-induced landslides as it considers both the transient and spatial response of pore pressure in its calculation of slope stability. The stability calculation used in SINMAP and LISA is similar and utilizes probability distribution functions for certain parameters. Unlike SINMAP that only considers soil cohesion, internal friction angle and rainfall-rate distributions, LISA allows the use of distributed data for all parameters, so it is the preferred model to evaluate slope stability over SINMAP. Results from all three models suggested similar soil and hydrologic properties for triggering the landslides that occurred during the 1995 storm in Madison County, Virginia. The colluvium probably had cohesion of less than 2KPa. The root-soil system is above the failure plane and consequently root strength and tree surcharge had negligible effect on slope stability. The result that the final location of the water table was near the ground surface is supported by the water budget analysis of the rainstorm conducted by Smith et al. (1996).

  1. Performance and diagnostic usefulness of commercially available enzyme linked immunosorbent assay and rapid kits for detection of HIV, HBV and HCV in India.

    Science.gov (United States)

    Maity, Susmita; Nandi, Srijita; Biswas, Subrata; Sadhukhan, Salil Kumar; Saha, Malay Kumar

    2012-11-26

    HIV, HBV and HCV pose a major public health problem throughout the world. Detection of infection markers for these agents is a major challenge for testing laboratories in a resource poor setting. As blood transfusion is an important activity saving millions of live every year, it also carries a risk of transfusion transmissible infections caused by these fatal blood borne pathogens if the quality of testing is compromised. Conventional ELISA is regarded as the mostly used screening technique but due to limitations like high cost, unavailability in many blood banks and testing sites, involvement of costly instruments, time taking nature and requirement of highly skilled personnel for interpretation, rapid tests are gaining more importance and warrants comparison of performance. A comparative study between these two techniques has been performed using commercially available diagnostic kits to assess their efficacy for detection of HIV, HBV and HCV infections. Rapid kits were more efficient in specificity with synthetic antigens along with high PPV than ELISA in most cases. Comparison between different ELISA kits revealed that Microlisa HIV and Hepalisa (J. Mitra & Co. Pvt. Ltd.); ERBA LISA HIV1 + 2, ERBA LISA Hepatitis B and ERBA LISA HCV (Transasia Bio-medicals Ltd.) gives uniform result with good performance in terms of sensitivity, specificity, PPV, NPV and efficiency, whereas, Microlisa HCV (J. Mitra & Co. Pvt. Ltd.), Microscreen HBsAg ELISA and INNOVA HCV (Span Diagnostics Ltd.) did not perform well. Rapid kits were also having high degree of sensitivity and specificity (100%) except in HIV Comb and HCV Comb (J. Mitra & Co. Pvt. Ltd.). The kit efficiency didn't vary significantly among different companies and lots in all the cases except for HCV ELISA showing statistically significant variation (p bank. For availability of quality commercial diagnostic assays, evaluation of kit may be helpful.

  2. Music from the heavens - gravitational waves from supermassive black hole mergers in the EAGLE simulations

    Science.gov (United States)

    Salcido, Jaime; Bower, Richard G.; Theuns, Tom; McAlpine, Stuart; Schaller, Matthieu; Crain, Robert A.; Schaye, Joop; Regan, John

    2016-11-01

    We estimate the expected event rate of gravitational wave signals from mergers of supermassive black holes that could be resolved by a space-based interferometer, such as the Evolved Laser Interferometer Space Antenna (eLISA), utilizing the reference cosmological hydrodynamical simulation from the EAGLE suite. These simulations assume a Lambda cold dark matter cosmogony with state-of-the-art subgrid models for radiative cooling, star formation, stellar mass loss, and feedback from stars and accreting black holes. They have been shown to reproduce the observed galaxy population with unprecedented fidelity. We combine the merger rates of supermassive black holes in EAGLE with the latest phenomenological waveform models to calculate the gravitational waves signals from the intrinsic parameters of the merging black holes. The EAGLE models predict ˜2 detections per year by a gravitational wave detector such as eLISA. We find that these signals are largely dominated by mergers between seed mass black holes merging at redshifts between z ˜ 2 and z ˜ 1. In order to investigate the dependence on the assumed black hole seed mass, we introduce an additional model with a black hole seed mass an order of magnitude smaller than in our reference model. We also consider a variation of the reference model where a prescription for the expected delays in the black hole merger time-scale has been included after their host galaxies merge. We find that the merger rate is similar in all models, but that the initial black hole seed mass could be distinguished through their detected gravitational waveforms. Hence, the characteristic gravitational wave signals detected by eLISA will provide profound insight into the origin of supermassive black holes and the initial mass distribution of black hole seeds.

  3. Observing a Gravitational Wave Background With Lisa

    National Research Council Canada - National Science Library

    Tinto, M; Armstrong, J; Estabrook, F

    2000-01-01

    .... Comparison of the conventional Michelson interferometer observable with the fully-symmetric Sagnac data-type allows unambiguous discrimination between a gravitational wave background and instrumental noise. The method presented here can be used to detect a confusion-limited gravitational wave background.

  4. Lower hybrid resonance plasma heating in the LISA machine. Aquecimento do plasma na ressonancia hibrida inferior na maquina LISA

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J C.X. da; Cunha Rapozo, C da [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica

    1988-10-01

    Plasma of helium was obtained using microwave source of f[sub RF] = 2.45 GHz and P[sub RF] = 800 W. Temperature and electron density were investigated for plasma excited by radiofrequency of f = 30 MHz and P[sub RF] = 0.1 kw. (M.C.K.).

  5. Geospatial Analysis of Unmet Surgical Need in Uganda: An Analysis of SOSAS Survey Data.

    Science.gov (United States)

    Farber, S Harrison; Vissoci, Joao Ricardo Nickenig; Tran, Tu M; Fuller, Anthony T; Butler, Elissa K; Andrade, Luciano; Staton, Catherine; Makumbi, Fredrick; Luboga, Samuel; Muhumuza, Christine; Namanya, Didacus B; Chipman, Jeffrey G; Galukande, Moses; Haglund, Michael M

    2017-02-01

    Globally, a staggering five billion people lack access to adequate surgical care. Sub-Saharan Africa represents one of the regions of greatest need. We sought to understand how geographic factors related to unmet surgical need (USN) in Uganda. We performed a geographic information system analysis of a nationwide survey on surgical conditions performed in 105 enumeration areas (EAs) representing the national population. At the district level, we determined the spatial autocorrelation of the following study variables: prevalence of USN, hub distance (distance from EA to the nearest surgical center), area of coverage (geographic catchment area of each center), tertiary facility transport time (average respondent-reported travel time), and care availability (rate of hospital beds by population and by district). We then used local indicators of spatial association (LISA) and spatial regression to identify any significant clustering of these study variables among the districts. The survey enumerated 4248 individuals. The prevalence of USN varied from 2.0-45 %. The USN prevalence was highest in the Northern and Western Regions. Moran's I bivariate analysis indicated a positive correlation between USN and hub distance (p = 0.03), area of coverage (p = 0.02), and facility transport time (p = 0.03). These associations were consistent nationally. The LISA analysis showed a high degree of clustering among sets of districts in the Northern Sub-Region. This study demonstrates a statistically significant association between USN and the geographic variables examined. We have identified the Northern Sub-Region as the highest priority areas for financial investment to reduce this unmet surgical disease burden.

  6. Infant and Child Mortality in India in the Last Two Decades: A Geospatial Analysis

    Science.gov (United States)

    Singh, Abhishek; Pathak, Praveen Kumar; Chauhan, Rajesh Kumar; Pan, William

    2011-01-01

    Background Studies examining the intricate interplay between poverty, female literacy, child malnutrition, and child mortality are rare in demographic literature. Given the recent focus on Millennium Development Goals 4 (child survival) and 5 (maternal health), we explored whether the geographic regions that were underprivileged in terms of wealth, female literacy, child nutrition, or safe delivery were also grappling with the elevated risk of child mortality; whether there were any spatial outliers; whether these relationships have undergone any significant change over historical time periods. Methodology The present paper attempted to investigate these critical questions using data from household surveys like NFHS 1992–1993, NFHS 1998–1999 and DLHS 2002–2004. For the first time, we employed geo-spatial techniques like Moran's-I, univariate LISA, bivariate LISA, spatial error regression, and spatiotemporal regression to address the research problem. For carrying out the geospatial analysis, we classified India into 76 natural regions based on the agro-climatic scheme proposed by Bhat and Zavier (1999) following the Census of India Study and all estimates were generated for each of the geographic regions. Result/Conclusions This study brings out the stark intra-state and inter-regional disparities in infant and under-five mortality in India over the past two decades. It further reveals, for the first time, that geographic regions that were underprivileged in child nutrition or wealth or female literacy were also likely to be disadvantaged in terms of infant and child survival irrespective of the state to which they belong. While the role of economic status in explaining child malnutrition and child survival has weakened, the effect of mother's education has actually become stronger over time. PMID:22073208

  7. Theory-Agnostic Constraints on Black-Hole Dipole Radiation with Multiband Gravitational-Wave Astrophysics.

    Science.gov (United States)

    Barausse, Enrico; Yunes, Nicolás; Chamberlain, Katie

    2016-06-17

    The aLIGO detection of the black-hole binary GW150914 opens a new era for probing extreme gravity. Many gravity theories predict the emission of dipole gravitational radiation by binaries. This is excluded to high accuracy in binary pulsars, but entire classes of theories predict this effect predominantly (or only) in binaries involving black holes. Joint observations of GW150914-like systems by aLIGO and eLISA will improve bounds on dipole emission from black-hole binaries by 6 orders of magnitude relative to current constraints, provided that eLISA is not dramatically descoped.

  8. Imprint of accretion disk-induced migration on gravitational waves from extreme mass ratio inspirals.

    Science.gov (United States)

    Yunes, Nicolás; Kocsis, Bence; Loeb, Abraham; Haiman, Zoltán

    2011-10-21

    We study the effects of a thin gaseous accretion disk on the inspiral of a stellar-mass black hole into a supermassive black hole. We construct a phenomenological angular momentum transport equation that reproduces known disk effects. Disk torques modify the gravitational wave phase evolution to detectable levels with LISA for reasonable disk parameters. The Fourier transform of disk-modified waveforms acquires a correction with a different frequency trend than post-Newtonian vacuum terms. Such inspirals could be used to detect accretion disks with LISA and to probe their physical parameters. © 2011 American Physical Society

  9. Studying stellar binary systems with the Laser Interferometer Space Antenna using delayed rejection Markov chain Monte Carlo methods

    International Nuclear Information System (INIS)

    Trias, Miquel; Vecchio, Alberto; Veitch, John

    2009-01-01

    Bayesian analysis of Laser Interferometer Space Antenna (LISA) data sets based on Markov chain Monte Carlo methods has been shown to be a challenging problem, in part due to the complicated structure of the likelihood function consisting of several isolated local maxima that dramatically reduces the efficiency of the sampling techniques. Here we introduce a new fully Markovian algorithm, a delayed rejection Metropolis-Hastings Markov chain Monte Carlo method, to efficiently explore these kind of structures and we demonstrate its performance on selected LISA data sets containing a known number of stellar-mass binary signals embedded in Gaussian stationary noise.

  10. Provintsist pärit IT-mõtleja / Alexander Galitsky ; interv. Viktoria Korpan

    Index Scriptorium Estoniae

    Galitsky, Alexander

    2005-01-01

    Venemaa tuntumaid info- ja kõrgtehnoloogiavaldkonna spetsialiste infotehnoloogiast ja selle erinevatest võimalustest, tehnoloogia lahendustest ning avastustest, turvaprobleemidest. Lisa: Alexander Galitsky

  11. Combining zonal refractive and diffractive aspheric multifocal intraocular lenses.

    Science.gov (United States)

    Muñoz, Gonzalo; Albarrán-Diego, César; Javaloy, Jaime; Sakla, Hani F; Cerviño, Alejandro

    2012-03-01

    To assess visual performance with the combination of a zonal refractive aspheric multifocal intraocular lens (MIOL) (Lentis Mplus, Oculentis GmbH) and a diffractive aspheric MIOL (Acri.Lisa 366, Acri.Tech GmbH). This prospective interventional cohort study comprised 80 eyes from 40 cataract patients (mean age: 65.5±7.3 years) who underwent implantation of the Lentis Mplus MIOL in one eye and Acri.Lisa 366 MIOL in the fellow eye. The main outcome measures were refraction; monocular and binocular uncorrected and corrected distance, intermediate, and near visual acuities; monocular and binocular defocus curves; binocular photopic contrast sensitivity function compared to a monofocal intraocular lens (IOL) control group (40 age-matched pseudophakic patients implanted with the AR-40e [Abbott Medical Optics]); and quality of vision questionnaire. Binocular uncorrected visual acuities were 0.12 logMAR (0.76 decimal) or better at all distances measured between 6 m and 33 cm. The Lentis Mplus provided statistically significant better vision than the Acri.Lisa at distances between 2 m and 40 cm, and the Acri.Lisa provided statistically significant better vision than the Lentis Mplus at 33 cm. Binocular defocus curve showed little drop-off at intermediate distances. Photopic contrast sensitivity function for distance and near were similar to the monofocal IOL control group except for higher frequencies. Moderate glare (15%), night vision problems (12.5%), and halos (10%) were reported. Complete independence of spectacles was achieved by 92.5% of patients. The combination of zonal refractive aspheric and diffractive aspheric MIOLs resulted in excellent uncorrected binocular distance, intermediate, and near vision, with low incidence of significant photic phenomena and high patient satisfaction. Copyright 2012, SLACK Incorporated.

  12. An ultra-stable iodine-based frequency reference for space applications

    Science.gov (United States)

    Schuldt, Thilo; Braxmaier, Claus; Doeringshoff, Klaus; Keetman, Anja; Reggentin, Matthias; Kovalchuk, Evgeny; Peters, Achim

    2012-07-01

    Future space missions require for ultra-stable optical frequency references. Examples are the gravitational wave detector LISA/eLISA (Laser Interferometer Space Antenna), the SpaceTime Asymmetry Research (STAR) program, the aperture-synthesis telescope Darwin and the GRACE (Gravity Recovery and Climate Experiment) follow on mission exploring Earth's gravity. As high long-term frequency stability is required, lasers stabilized to atomic or molecular transitions are preferred, also offering an absolute frequency reference. Frequency stabilities in the 10 ^{-15} domains at longer integration times (up to several hours) are demonstrated in laboratory experiments using setups based on Doppler-free spectroscopy. Such setups with a frequency stability comparable to the hydrogen maser in the microwave domain, have the potential to be developed space compatible on a relatively short time scale. Here, we present the development of ultra-stable optical frequency references based on modulation-transfer spectroscopy of molecular iodine. Noise levels of 2\\cdot10 ^{-14} at an integration time of 1 s and below 3\\cdot10 ^{-15} at integration times between 100 s and 1000 s are demonstrated with a laboratory setup using an 80 cm long iodine cell in single-pass configuration in combination with a frequency-doubled Nd:YAG laser and standard optical components and optomechanic mounts. The frequency stability at longer integration times is (amongst other things) limited by the dimensional stability of the optical setup, i.e. by th pointing stability of the two counter-propagating beams overlapped in the iodine cell. With the goal of a future space compatible setup, a compact frequency standard on EBB (elegant breadboard) level was realized. The spectroscopy unit utilizes a baseplate made of Clearceram-HS, a glass ceramics with an ultra-low coefficient of thermal expansion of 2\\cdot10 ^{-8} K ^{-1}. The optical components are joint to the baseplate using adhesive bonding technology

  13. Revealing the Formation of Stellar-mass Black Hole Binaries: The Need for Deci-Hertz Gravitational-wave Observatories

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xian [Astronomy Department, School of Physics, Peking University, 100871 Beijing (China); Amaro-Seoane, Pau, E-mail: xian.chen@pku.edu.cn, E-mail: pau@ice.cat [Institut de Ciències de l’Espai (CSIC-IEEC) at Campus UAB, Carrer de Can Magrans s/n, E-08193 Barcelona (Spain)

    2017-06-10

    The formation of compact stellar-mass binaries is a difficult, but interesting problem in astrophysics. There are two main formation channels: in the field via binary star evolution, or in dense stellar systems via dynamical interactions. The Laser Interferometer Gravitational-wave Observatory (LIGO) has detected black hole binaries (BHBs) via their gravitational radiation. These detections provide us with information about the physical parameters of the system. It has been claimed that when the Laser Interferometer Space Antenna (LISA) is operating, the joint observation of these binaries with LIGO will allow us to derive the channels that lead to their formation. However, we show that for BHBs in dense stellar systems dynamical interactions could lead to high eccentricities such that a fraction of the relativistic mergers are not audible to LISA. A non-detection by LISA puts a lower limit of about 0.005 on the eccentricity of a BHB entering the LIGO band. On the other hand, a deci-Hertz observatory, like DECIGO or Tian Qin, would significantly enhance the chances of a joint detection and shed light on the formation channels of these binaries.

  14. The uncatchable smile in Leonardo da Vinci's La Bella Principessa portrait.

    Science.gov (United States)

    Soranzo, Alessandro; Newberry, Michelle

    2015-08-01

    A portrait of uncertain origin recently came to light which, after extensive research and examination, was shown to be that rarest of things: a newly discovered Leonardo da Vinci painting entitled La Bella Principessa. This research presents a new illusion which is similar to that identified in the Mona Lisa; La Bella Principessa's mouth appears to change slant depending on both the Viewing Distance and the Level of Blur applied to a digital version of the portrait. Through a series of psychophysics experiments, it was found that a perceived change in the slant of the La Bella Principessa's mouth influences her expression of contentment thus generating an illusion that we have coined the "uncatchable smile". The elusive quality of the Mona Lisa's smile has been previously reported (Science, 290 (2000) 1299) and so the existence of a similar illusion in a portrait painted prior to the Mona Lisa becomes more interesting. The question remains whether Leonardo da Vinci intended this illusion. In any case, it can be argued that the ambiguity created adds to the portrait's allure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Mart Habakuk viis esimese Eesti ettevõtte Londoni börsile / Mart Habakuk ; interv. Jaanika Merilo

    Index Scriptorium Estoniae

    Habakuk, Mart, 1969-

    2007-01-01

    Metro Capital Managementi juhatuse esimees Mart Habakuk tutvustab kinnisvarainvesteerimisfirma Metro Baltic Horizons noteerimist Londoni alternatiivnimekirja AIM. Lisa: Metro Capital Management; Mart Habakuk

  16. Saksa valimisi kummitab ajalootaak / Jeroen Bult

    Index Scriptorium Estoniae

    Bult, Jeroen

    2005-01-01

    Saksamaa parlamendivalimiste kantslerikandidaatide - sotsiaaldemokraat Gerhard Schröderi ja kristliku demokraadi Angela Merkeli valimiskampaaniatest ning välispoliitilistest ideedest. Lisa: Angela Merkel

  17. Gravitational-Wave Astronomy

    Science.gov (United States)

    Kelly, Bernard J.

    2010-01-01

    Einstein's General Theory of Relativity is our best classical description of gravity, and informs modern astronomy and astrophysics at all scales: stellar, galactic, and cosmological. Among its surprising predictions is the existence of gravitational waves -- ripples in space-time that carry energy and momentum away from strongly interacting gravitating sources. In my talk, I will give an overview of the properties of this radiation, recent breakthroughs in computational physics allowing us to calculate the waveforms from galactic mergers, and the prospect of direct observation with interferometric detectors such as LIGO and LISA.

  18. Gravitational waves from double white dwarfs and AM CVn binaries

    International Nuclear Information System (INIS)

    Nelemans, Gijs

    2003-01-01

    I give a brief overview of our model for the galactic population of compact binaries that is used to predict the low-frequency gravitational wave signal from the galaxy, and discuss recent observational developments that will enable us to test and improve this model. The SPY project will discover some 150 new close double white dwarfs and, recently, two ROSAT sources turned out to be new AM CVn candidates, one with an orbital period of only 5 min. I give an update on the expected binaries that will be resolved by LISA and discuss what we can learn about the galactic population of compact binaries once LISA gives her first results

  19. Knocking on heaven's door. How physics and scientific thinking illuminate the universe and the modern world

    International Nuclear Information System (INIS)

    Randall, Lisa

    2012-01-01

    In her new book the Harvard professor and bestseller author Lisa Randall tells excitingly and somewhat ''from the front'' of the inner workings of science: What matters go to physicists? Which role play such gigantic apparatuses like the particle accelerator at CERN? What's the deal with the search for the Higgs boson itself? How applied and theoretical physics are connected? Lisa Randall designs clearly and excitingly the picture of contemporary physics in all its facets and lets become concrete, how the modern basic research works. An entertaining, instructive insight into the fascinating world of physics and simultaneously a praise of the creative powers of the human mind and the science.

  20. The consequences of attempting to equalize the income of local governments in Estonia / Janno Reiljan, Kairi Andresson, Kadri Ukrainski

    Index Scriptorium Estoniae

    Reiljan, Janno, 1951-2018

    2004-01-01

    Kohalike omavalitsuste finantseerimisest. Hinnang keskvalitsuse edukusele kohalike omavalitsuste tulude võrdsustamisel ning antud poliitika ohtudele. Skeem. Tabelid. Diagramm. Graafik. Kaardid. Lisa lk. 381

  1. Itaallased otsustasid suurärimees Berlusconi valitsemise alla naasta / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2008-01-01

    Itaalia erakorralised parlamendivalimised võitis juba kolmandat korda endine peaminister Silvio Berlusconi. Diagramm: Berlusconi miljardid. Lisa: Võimule aitas meediarusikas; Jõukuse allikas on teadmata

  2. Impact of Mergers on USA Parameter Estimation for Nonspinning Black Hole Binaries

    Science.gov (United States)

    McWilliams, Sean T.; Thorpe, James Ira; Baker, John G.; Kelly, Bernard J.

    2011-01-01

    We investigate the precision with which the parameters describing the characteristics and location of nonspinning black hole binaries can be measured with the Laser Interferometer Space Antenna (LISA). By using complete waveforms including the inspiral, merger and ringdown portions of the signals, we find that LISA will have far greater precision than previous estimates for nonspinning mergers that ignored the merger and ringdown. Our analysis covers nonspinning waveforms with moderate mass ratios, q > or = 1/10, and total masses 10(exp 5) < M/M_{Sun} < 10(exp 7). We compare the parameter uncertainties using the Fisher matrix formalism, and establish the significance of mass asymmetry and higher-order content to the predicted parameter uncertainties resulting from inclusion of the merger. In real-time observations, the later parts of the signal lead to significant improvements in sky-position precision in the last hours and even the final minutes of observation. For comparable mass systems with total mass M/M_{Sun} = approx. 10(exp 6), we find that the increased precision resulting from including the merger is comparable to the increase in signal-to-noise ratio. For the most precise systems under investigation, half can be localized to within O(10 arcmin), and 18% can be localized to within O(1 arcmin).

  3. Quasilocal contribution to the scalar self-force: Geodesic motion

    International Nuclear Information System (INIS)

    Ottewill, Adrian C.; Wardell, Barry

    2008-01-01

    We consider a scalar charge travelling in a curved background space-time. We calculate the quasilocal contribution to the scalar self-force experienced by such a particle following a geodesic in a general space-time. We also show that if we assume a massless field and a vacuum background space-time, the expression for the self-force simplifies significantly. We consider some specific cases whose gravitational analogs are of immediate physical interest for the calculation of radiation-reaction corrected orbits of binary black hole systems. These systems are expected to be detectable by the LISA space based gravitational wave observatory. We also investigate how alternate techniques may be employed in some specific cases and use these as a check on our own results

  4. Modernizatsija portovoi infrastrukturõ i uroven obsluzhivanija v Klaipedskom portu = The modernisation of the port infrastructure and the level of services in the Klaipeda port / Sigitas Dobilinskas

    Index Scriptorium Estoniae

    Dobilinskas, Sigitas

    2004-01-01

    Ettekanne 11.-12. oktoobrini Peterburis toimunud konverentsil. Klaipeda sadama olukorrast, infrastruktuuri moderniseerimisest, teenuste tasemest, tulevikuplaanidest, võrdlus Kaliningradi ning Peterburi sadamatega. Lisa: Sigitas Dobilinskas

  5. Blairi mantli pärast algas leiboristide vaheline heitlus / Siim Trumm

    Index Scriptorium Estoniae

    Trumm, Siim

    2006-01-01

    Leiboristliku Partei juhi kohale soovib peale Suurbritannia rahandusministri Gordon Browni kandideerida ka siseminister John Reid. Ministrid esindavad erinevaid poliitilisi suundi. Lisa: Blairi sõnum

  6. Strateegiaguru Porter, klastriguru Porter, sponsorlusguru Porter. Peaaegu, et gurude guru!

    Index Scriptorium Estoniae

    2005-01-01

    Maailma juhtiva strateegiaguru, Harvard Business Schooli professori Michael Porteri seisukohtadest ja ideedest ettevõtete heategevuse, Interneti kui majandusharu ning klastrite kohta. Lisa: Michael Porter

  7. Government teeters on edge of collapse / Aleksei Gunter

    Index Scriptorium Estoniae

    Gunter, Aleksei, 1979-

    2005-01-01

    Valitsuses tekkinud kriisist seoses justiitsministri korruptsiooni vastu võitlemise programmiga. Lisa: Res Publica ja Keskerakond ühinesid Tallinnas. Tabel: Kohtade jagunemine erakondade vahel Riigikogus

  8. Kuusalus saab rattad alla autotreileritööstus / Peep Talimaa

    Index Scriptorium Estoniae

    Talimaa, Peep

    2008-01-01

    OÜ-le Trucks & Trailers kuuluvast Kuusalu treileritehasest. Lisa: Kuusalu treileritehase ajalugu ja eellugu; Autotreileri valmimine; Üldandmeid treilerite kohta; Kuusalu treileritehase ajalugu ja eellugu

  9. Kerry kangutab Bushi võimult koos Edwardsiga / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2004-01-01

    USA Demokraatliku Partei presidendikandidaat John Kerry valis oma asepresidendikandidaadiks endise konkurendi John Edwardsi eesmärgiga kindlustada omale toetust lõunaosariikides. Lisa: Presidendivalimiste paarisrakend

  10. Kerry panustab jõule ja tarkusele / Neeme Raud

    Index Scriptorium Estoniae

    Raud, Neeme, 1969-

    2004-01-01

    Autor teeb ülevaate lõppevast USA demokraatide valimiseelsest kongressist, mille peateemaks oli presidendikandidaadi John Kerry laiemale avalikkusele tutvustamine. Lisa: Demokraatide kandidaat John Kerry

  11. Keskkonnaraha kolis taotlejate juurde / Andres Pulver

    Index Scriptorium Estoniae

    Pulver, Andres, 1965-

    2005-01-01

    Keskkonnainvesteeringute keskus (KIK) avas maakondlikud esindused, mis abistavad projektide arendajaid keskkonnaprojektide toetuste taotlemisel, projektide elluviimisel ning kontrollivad toetuste sihipärast kasutamist. Lisa: KIK

  12. Turutõrge Eesti riskikapitaliturul / Margus Kõomägi

    Index Scriptorium Estoniae

    Kõomägi, Margus

    2005-01-01

    Riigi majanduspoliitikast riskikapitalituru tõrke vähendamisel, informatsiooni asümmeetria esinemisest Eesti riskikapitaliturul. Tabelid. Lisa: Informatsiooni asümmeetria esinemine Eesti riskikapitaliturul

  13. Jüri Ratas: tasulise parkimise ala suurendamine probleeme ei tekita / Jüri Ratas ; interv. Askur Alas

    Index Scriptorium Estoniae

    Ratas, Jüri, 1978-

    2004-01-01

    Tallinna abilinnapea tasulise parkimise ala laiendamisest Tallinna kesklinnas ja sellega kaasnevatest võimalikest probleemidest. Kommenteerib Johannes Pirita. Kaart. Lisa: Rahvaalgatus sõdib tasulise parkimisega

  14. Modular Gravitational Reference Sensor (MGRS) For Astrophysics and Astronomy

    Science.gov (United States)

    Sun, Ke-Xun; Buchman, S.; Byer, R. L.; DeBra, D.; Goebel, J.; Allen, G.; Conklin, J.; Gerardi, D.; Higuchi, S.; Leindecker, N.; Lu, P.; Swank, A.; Torres, E.; Trillter, M.; Zoellner, A.

    2009-01-01

    The study of space-time for gravitational wave detection and cosmology beyond Einstein will be an important theme for astrophysics and astronomy in decades to come. Laser Interferometric Space Antenna (LISA) is designed for detecting gravitational wave in space. The Modular Gravitational Reference Sensor (MGRS) is developed as the next generation core instrument for space-time research, including gravitational wave detection beyond LISA, and an array of precision experiments in space. The MGRS provide a stable gravitational cardinal point in space-time by using a test sphere, which eliminates the need for orientation control, minimizing disturbances. The MGRS measures the space-time variation via a two step process: measurement between test mass and housing, and between housings of two spacecraft. Our Stanford group is conducting systematic research and development on the MGRS. Our initial objectives are to gain a system perspective of the MGRS, to develop component technologies, and to establish test platforms. We will review our recent progress in system technologies, optical displacement and angle sensing, diffractive optics, proof mass characterization, UV LED charge management system and space qualification, thermal control and sensor development. Some highlights of our recent results are: Demonstration of the extreme radiation hardness of UV LED which sustained 2 trillion protons per square centimeter; measurement of mass center offset down to 300 nm, and measurement of small angle 0.2 nrad per root hertz using a compact grating angular sensor. The Stanford MGRS program has made exceptional contribution to education of next generation scientists and engineers. We have undergraduate and graduate students in aeronautical and astronautic engineering, applied physics, cybernetics, electrical engineering, mechanical engineering, and physics. We have also housed a number of high school students in our labs for education and public outreach.

  15. Ecuador pagendas neljanda riigipea / Allan Espenberg

    Index Scriptorium Estoniae

    Espenberg, Allan

    2005-01-01

    Ecuadori parlament tagandas riigipea Lucio Gutierreze. L. Gutierrez, kellele sai saatuslikuks kolmele ekspresidendile amnestia andmine, pages koos perega Brasiiliasse. Lisa: Kontinendi üks sportlikumaid presidente

  16. Haapsalu Lossiaed erastamise keerises / Toivo Meikar

    Index Scriptorium Estoniae

    Meikar, Toivo, 1947-

    2002-01-01

    Haapsalu lossiaia juriidilisest kuuluvusest, 1920. a. esimese poole vaidluste ja kohtuprotsesside tagapõhjast ning tulemist. Lisa: Haapsalu linna plaanid, lossiaia kruntimise kava, lossiaia üldplaan

  17. Euroopa Parlamendist ei saa kunagi tõeliste eurooplaste esinduskogu / Jeroen Bult

    Index Scriptorium Estoniae

    Bult, Jeroen

    2004-01-01

    EL-i liikmesriikide inimeste suhtumisest Euroopa Parlamendi valimistesse ja parlamendi funktsioonide muutmise vajadusest. Vt. samas: Euroopa tähistab valimiste veerandsajandit. Lisa: EL-i liikmesriigid

  18. Siseminister Pihl saab arvestada 300 lisamiljoniga / Tuuli Koch

    Index Scriptorium Estoniae

    Koch, Tuuli

    2008-01-01

    2009. aasta riigieelarve koostamisel tegi rahandusministeerium 3,5 miljardi krooni suuruse lisapakkumise, millest 300 miljonit peaks pehmendama siseministeeriumi koondamise ja kokkuhoiu stsenaariumi. Lisa: Must stsenaarium

  19. Riskikapitali hinnakujunemise mehhanism / Margus Kõomägi

    Index Scriptorium Estoniae

    Kõomägi, Margus

    2005-01-01

    Riskikapitali hinna mõjuritest, kapitalivarade hindamise mudeli (CAPM) kasutamisest hinna leidmisel, riskikorrektiiviga diskontomäärast, riskikapitali hinnast Eestis. Tabelid. Diagrammid. Lisa lk. 109-110

  20. Maxima poekett mitmendat aastat järjest keeleinspektsiooni murelaps / Dannar Leitmaa

    Index Scriptorium Estoniae

    Leitmaa, Dannar, 1982-

    2008-01-01

    Kauplusekettidest on kõige rohkem saanud keeleinspektsioonilt ettekirjutusi Maxima. Inspektsiooni nõuniku Hele Pärna, Maxima pressiesindaja Erkki Erilaiu selgitusi. Lisa: Probleem haridussüsteemis?

  1. Marek Strandberg - rohelise tee mees / Marek Strandberg ; interv. Toomas Jüriado

    Index Scriptorium Estoniae

    Strandberg, Marek, 1965-

    2004-01-01

    Euroopa Parlamendi saadikukandidaat Marek Strandberg propageerib kolmanda, rohelise tee valikut Eesti ja Euroopa jaoks, mis tähendab uute loodussõbralike tehnoloogiate rakendamist. Lisa: Eesti keskkonnaindikaatorid

  2. Spetsialistid soovitavad kesklinnas piirata sõidukite kiirust 40 km/h-ni / Askur Alas

    Index Scriptorium Estoniae

    Alas, Askur, 1973-

    2004-01-01

    Liiklusspetsialistid soovitavad inimvigastustega õnnetuste vähendamiseks piirata Tallinna kesklinnas kiirust 40 km/h-ni. Linna liiklusteenistus ei pea seda põhjendatuks. Lisa: Helsingi positiivne kogemus

  3. Itaalia pööraks Prodiga pilgu enam Euroopasse / Erkki Bahovski

    Index Scriptorium Estoniae

    Bahovski, Erkki, 1970-

    2006-01-01

    10. aprillil Itaalias toimunud parlamendivalimistest: uksesuuküsitluste andmetel on vasaktsentristide juht Romano Prodi saamas 50-54 protsenti valijate häältest. Lisa: Võidukursil vasaktsentristid

  4. Valgevenest Iraanini : Venezuela liider koob USA-vastas ühisrinnet / Krister Paris

    Index Scriptorium Estoniae

    Paris, Krister, 1977-

    2006-01-01

    Venezuela president Hugo Chavez külastab mitmeid Ameerika Ühendriikidele probleemseid riike. Kohtumine Valgevene presidendi Aleksandr Lukashenkoga, eelseisvast visiidist Venemaale. Lisa: Chavez tahab julgeolekunõukogusse

  5. Kapten Brus : "Tank on argument." / Neeme Brus ; interv. Rainer Kerge

    Index Scriptorium Estoniae

    Brus, Neeme, 1957-

    2005-01-01

    Bagdadis avalike suhete ohvitserina teeniv kapten Neeme Brus Iraagi elanike suhtumisest rahutagamismissioonil olevatesse sõduritesse, koalitsioonivägede omavahelisest suhtlemisest, terrorismiohust. Lisa: Valitsus toetas missiooni pikendamist

  6. Tuiksoo kinkis ärimeestele ja poliitikutele kalleid jopesid / Mirko Ojakivi

    Index Scriptorium Estoniae

    Ojakivi, Mirko

    2007-01-01

    Põllumajandusministeerium kavatseb kinkida põllumajandusega seotud ettevõtjatele ja poliitikutele kokku 150 Ilves Extralt ostetud jopet. Ministeeriumi pressiesindaja Karina Loi selgitus. Lisa: Miljon krooni maksev kokaraamat

  7. Prantslased ihuvad hammast TeliaSonerale / Virge Lahe

    Index Scriptorium Estoniae

    Lahe, Virge

    2008-01-01

    Prantsuse telekommunikatsioonifirma France Telecom tahab osta Skandinaavia suurima telekommunikatsiooniettevõtte, Eesti Telekomi emafirma TeliaSonera. Diagrammid: TeliaSonera ja France Telecomi aktsiad. Lisa: Euroopa suurimad telekommunikatsioonifirmad

  8. Linlased ja rüütlikultuur : kaupmeeste võitlusmängud keskaegses Tallinnas ja Riias / Anu Mänd

    Index Scriptorium Estoniae

    Mänd, Anu, 1968-

    2002-01-01

    Liivimaa linnades harrastatud või(s)tlusliikidest (Gestech,Rennen, Kranzstechen, Ringelrennen).Lisa: Riialane Hinrich Millich kutsub Tallinna mustpeavendi võistlema rõnga läbitorkamises (Kranzstechen)

  9. Ettevõtluse tugivõrgustik juhib arengut / Kerttu Kongas

    Index Scriptorium Estoniae

    Kongas, Kerttu

    2008-01-01

    Väikestele ja keskmise suurusega ettevõtetele teenuseid osutavate organisatsioonide võrgustikust Enterprise Europe Network (EEN). Lisa: Enterprise Europe Networki kuuluvad riigid; Võrgustikku kuuluvad Eesti organisatsioonid

  10. Eesti noored võitsid kutsevõistlustelt kuus medalit

    Index Scriptorium Estoniae

    2008-01-01

    9. oktoobril lõppes Kuressaares Euroopa Hotelli- ja Turismikoolide Assotsiatsiooni aastakonverents, mille raames korraldatud kutsevõistlustelt võitsid Eesti noored kuus medalit. Lisa: EHRL stipendiaadid 2008

  11. Civic commitment, political culture and the Estonian inter-war generation / Li Bennich-Björkman

    Index Scriptorium Estoniae

    Bennich-Björkman, Li

    2007-01-01

    Sõdadevahelises Eesti Vabariigis väljakujunenud kodanikupanuse ja poliitilise kultuuri vaimse pärandi kaasaega edasikandumine mõjutas ülemineku ja demokratiseerumisprotsesse Eestis. Lisa: Tabelid, diagrammid

  12. Meditsiinireform ja selle mõju diabeetikutele

    Index Scriptorium Estoniae

    2003-01-01

    Oktoobris 2002 jõustunud ravikindlustuse seadusest. Lisatud sotsiaalministrile saadetud kirjad seoses seadusemuudatustega ja artikkel ajalehest Postimees (2003) 16. apr. Lisa : kust leian oma endokrinoloogi : [haiglate loend

  13. Haige astronaut venitab Atlantise missiooni / Liisi Poll

    Index Scriptorium Estoniae

    Poll, Liisi, 1980-

    2008-01-01

    Saksamaa astronaut ei saanud haiguse tõttu minna avakosmosesse, mistõttu lükkus edasi ka Euroopa Kosmoseagentuuri laborimooduli paigaldamine rahvusvahelisse kosmosejaama (ISS). Lisa: Teaduslabor Columbos

  14. Introduction Introduction

    Directory of Open Access Journals (Sweden)

    Gilles Couderc

    2011-12-01

    Full Text Available Les articles inclus dans ce recueil procèdent d’une réflexion sur les enjeux esthétiques, sociaux, politiques et identitaires de l’opéra qui s’inscrit dans le prolongement des études publiées dans divers numéros de la Revue LISA/LISA e-journal. Le thème retenu dans cet ouvrage est celui de la réécriture du patrimoine anglophone à l’opéra dans la sphère anglophone et européenne. Ce patrimoine anglophone, principalement littéraire, comprend récits historiques, romans, poèmes, pièces de théâtre ...

  15. 'Kludge' gravitational waveforms for a test-body orbiting a Kerr black hole

    International Nuclear Information System (INIS)

    Babak, Stanislav; Fang Hua; Gair, Jonathan R.; Glampedakis, Kostas; Hughes, Scott A.

    2007-01-01

    One of the most exciting potential sources of gravitational waves for low-frequency, space-based gravitational wave (GW) detectors such as the proposed Laser Interferometer Space Antenna (LISA) is the inspiral of compact objects into massive black holes in the centers of galaxies. The detection of waves from such 'extreme mass ratio inspiral' systems (EMRIs) and extraction of information from those waves require template waveforms. The systems' extreme mass ratio means that their waveforms can be determined accurately using black hole perturbation theory. Such calculations are computationally very expensive. There is a pressing need for families of approximate waveforms that may be generated cheaply and quickly but which still capture the main features of true waveforms. In this paper, we introduce a family of such kludge waveforms and describe ways to generate them. Different kinds of kludges have already been used to scope out data analysis issues for LISA. The models we study here are based on computing a particle's inspiral trajectory in Boyer-Lindquist coordinates, and subsequent identification of these coordinates with flat-space spherical polar coordinates. A gravitational waveform may then be computed from the multipole moments of the trajectory in these coordinates, using well-known solutions of the linearised gravitational perturbation equations in flat space time. We compute waveforms using a standard slow-motion quadrupole formula, a quadrupole/octupole formula, and a fast-motion, weak-field formula originally developed by Press. We assess these approximations by comparing to accurate waveforms obtained by solving the Teukolsky equation in the adiabatic limit (neglecting GW backreaction). We find that the kludge waveforms do extremely well at approximating the true gravitational waveform, having overlaps with the Teukolsky waveforms of 95% or higher over most of the parameter space for which comparisons can currently be made. Indeed, we find these

  16. Performance and diagnostic usefulness of commercially available enzyme linked immunosorbent assay and rapid kits for detection of HIV, HBV and HCV in India

    Directory of Open Access Journals (Sweden)

    Maity Susmita

    2012-11-01

    Full Text Available Abstract Background HIV, HBV and HCV pose a major public health problem throughout the world. Detection of infection markers for these agents is a major challenge for testing laboratories in a resource poor setting. As blood transfusion is an important activity saving millions of live every year, it also carries a risk of transfusion transmissible infections caused by these fatal blood borne pathogens if the quality of testing is compromised. Conventional ELISA is regarded as the mostly used screening technique but due to limitations like high cost, unavailability in many blood banks and testing sites, involvement of costly instruments, time taking nature and requirement of highly skilled personnel for interpretation, rapid tests are gaining more importance and warrants comparison of performance. Results A comparative study between these two techniques has been performed using commercially available diagnostic kits to assess their efficacy for detection of HIV, HBV and HCV infections. Rapid kits were more efficient in specificity with synthetic antigens along with high PPV than ELISA in most cases. Comparison between different ELISA kits revealed that Microlisa HIV and Hepalisa (J. Mitra & Co. Pvt. Ltd.; ERBA LISA HIV1 + 2, ERBA LISA Hepatitis B and ERBA LISA HCV (Transasia Bio-medicals Ltd. gives uniform result with good performance in terms of sensitivity, specificity, PPV, NPV and efficiency, whereas, Microlisa HCV (J. Mitra & Co. Pvt. Ltd., Microscreen HBsAg ELISA and INNOVA HCV (Span Diagnostics Ltd. did not perform well. Rapid kits were also having high degree of sensitivity and specificity (100% except in HIV Comb and HCV Comb (J. Mitra & Co. Pvt. Ltd.. The kit efficiency didn’t vary significantly among different companies and lots in all the cases except for HCV ELISA showing statistically significant variation (p  Conclusions ELISA is a good screening assay for markers of HIV, HBV and HCV infections. Rapid tests are useful for

  17. Cancellation of differential accelerations for the LISA spacecraft

    International Nuclear Information System (INIS)

    Bender, Peter L

    2006-01-01

    The three spacecraft of the Laser Interferometer Space Antenna will form a nearly equilateral triangle with nominal side lengths of 5 million km. However, the arm lengths and the corner angles will vary by very roughly 1% over 5-10 years. Part of this variation is due to the nature of Kepler orbits around the Sun. But Sweetser (2006 Astrodynamics 2005, Advances in the Astronautical Sciences vol 123 (San Diego, CA: Univelt Inc.) pp 693-712) has shown recently that differential secular accelerations due to the Earth for the three spacecraft prevent the minimal variations from being preserved for more than 2 or 3 years. Based on Sweetser's results, it appears possible to cancel out the differential secular acceleration due to the Earth by applying forces to the two proof masses in each spacecraft. The applied acceleration is at most 2.1 x 10 -9 m s -2 . However, the directions of the required accelerations would have substantial components along the sides of the triangle, and thus the amplitudes of the applied forces would have to have very low noise, even at frequencies down to below 0.1 mHz

  18. Web aitab nutikamaid firmasid / Peeter Stamberg

    Index Scriptorium Estoniae

    Stamberg, Peeter

    2003-01-01

    Interneti-lahendustesse investeerimine on aidanud paljudel ettevõtetel oma tulemusi parandada. Autor teeb ülevaate ajakirjas BusinessWeek avaldatud edukamatest internetiprojektidest. Lisa: Internetiäri teine laine

  19. Uued lahendused kliendisuhete halduses / Michael Stimson

    Index Scriptorium Estoniae

    Stimson, Michael

    2008-01-01

    Autor kirjeldab klienditeeninduse parandamist kliendihaldustarkvara Microsoft Dynamics CRM kasutamise abil. Skeem: Täiustatud teeninduskogemus. Lisa: Kliendihaldus algas kümmekond aastat tagasi; CRM aitab lahendada riigiasutuste probleeme

  20. AS-i Steri tehas alustab tööd juba lähipäevil / Ulvar Käärt

    Index Scriptorium Estoniae

    Käärt, Ulvar, 1982-

    2007-01-01

    Keskkonnaminister Jaanus Tamkivi andis AS-ile Steri kiirgustegevusloa. Samas otsustas minister edasi kaevata AS Steri omanike kasuks tehtud Tallinna halduskohtu otsuse. Lisa: Steriliseerimine AS-i Steri tehases

  1. Linn 2 viigi ja 2 oosiga = Gorod s 2 zalivami i 2 grjadami / Veronika Nuter

    Index Scriptorium Estoniae

    Nuter, Veronika

    2008-01-01

    Haapsalu elamumajandusest. Nõukogude ajal lõpetamata jäänud majakarpidest ümberehitatud korterelamutest Kastani 28 ja 35 (arhitektuurne lahendus: AB Muru & Pere). Lisa: Haapsalu tegudes & arvudes

  2. Kui vajad lojaalsust, siis võta koer! / Hando Sinisalu

    Index Scriptorium Estoniae

    Sinisalu, Hando, 1970-

    2008-01-01

    Briti kaubanduskontserni Tesco kliendilojaalsusprogrammist. Lisa: Lojaalsusprogrammi juhtimismudel; Eduka kliendiprogrammi kuus kriteeriumi. Vt. samas: Tarmo Hõbe. Me ei müü üksikuid tooteid, vaid elustiili ja emotsioone

  3. 43 miljardi mees Warren Buffett / Mart Raudsaar

    Index Scriptorium Estoniae

    Raudsaar, Mart, 1973-

    2004-01-01

    Ajaloo edukaimaks investoriks nimetatud Warren Buffett'i põhimõtetest investeerimisotsuste tegemisel ja temale kuuluva investeerimisfirma Berkshire Hathaway tegevusest Ameerika Ühendriikides. Lisa: Neli iva algajale kullakaevajale

  4. Norralased kahtlevad Veerpalu Lahti MMi kuldmedali õigsuses / Andrus Nilk

    Index Scriptorium Estoniae

    Nilk, Andrus, 1962-

    2002-01-01

    Norra meedia andmetel kuulus Andrus Veerpalu 2001. aastal Lahti maailmameistrivõistlustel uuritud kaheteistkümne medaliomaniku hulka, kelle verepilt erines tugevasti tavapärasest. Lisa: Aftenposteni shokinimekiri

  5. Kosovo ootab nüüd iseseisvuse väljakuulutamist tuleval aastal / Liisi Poll

    Index Scriptorium Estoniae

    Poll, Liisi, 1980-

    2007-01-01

    Kosovo valimised võitis Kosovo Vabastusarmee (UCK) poliitilise tiiva juhi Hashim Thaci Kosovo Demokraatlik Partei. Kosovlaste lootusest EL-i ja USA abile iseseisvuse saavutamisel. Lisa: Verine ajalugu

  6. Spielend Lernen oder ernstes Spielen?

    Directory of Open Access Journals (Sweden)

    Franco Rau

    2015-02-01

    Full Text Available Rezension zu: Gundolf S. Freyermuth, Lisa Gotto und Fabian Wallenfels, Hrsg. Serious Games, Exergames, Exerlearning: Zur Transmedialisierung und Gamification des Wissenstransfers. Bielefeld: transcript, 2013

  7. Miljardärist Ameerika teksatööstur pööritab Tallinna kinnisvaraturul raha / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2006-01-01

    Teksatööstuse Jordache president Shaul Nakash paigutab raha kinnisvarasse Tallinnas ning kavatseb hakata tegelema ka kinnisvaraarendusega. Nakashi äriimpeeriumile kuuluvast varast. Lisa: Nakashite perekonna impeerium

  8. Ameerika rahva tunnustus innustab Moore'i jätkama / Margit Tõnson

    Index Scriptorium Estoniae

    Tõnson, Margit, 1978-

    2005-01-01

    Ameerika kinokülastajad valisid 2004. aasta oma maa parimaks filmiks (People's Choice Award) Michael Moore'i dokumentaali "Fahrenheit 9/11". Lisa : nimekiri "Rahva lemmikud" teistest auhinnasaajatest

  9. Sada ja üks Eesti poliitilist karikatuuri / Aare Kasemets, Eiki Berg

    Index Scriptorium Estoniae

    Kasemets, Aare, 1963-

    2004-01-01

    Eesti ajalehtede poliitilised karikatuurid on Lääne-Euroopa ja USA ajakirjanduse pilapiltidega võrreldes üldjuhul inimsõbralikud, leiavad autorid. Tabel. Lisa: 2003. aasta karikatuurivalimise tulemused

  10. The year of political advertising - now! / Marius Vaupsas

    Index Scriptorium Estoniae

    Vaupsas, Marius

    2004-01-01

    BBDO Lukrecijos Reklama juht prognoosib 2004. aastat Leedu reklaamiturul, poliitilisest reklaamist, poliitikute ja reklaamispetsialistide vahelistest suhetest ning reklaamiagentuuride rollist poliitilistes valimiskampaaniates. Lisa: Some examples of successful cooperation

  11. Raskustes Onistari tennisehall saab rahasüsti / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2005-01-01

    Rootsi investeerimisfondide haldusfirma Askembla Asset Management investeerib Onistari tennisehalli 20 miljonit krooni, kuhu rajab veekompleksi ja Eesti ühe suurema jõusaali. Lisa: Konkurent: julge ettevõtmine

  12. Projektfinantseerimine - väljakutse uuendusmeelsele ettevõtjale / Rain Raa

    Index Scriptorium Estoniae

    Raa, Rain

    2005-01-01

    LL.M (Finance) jurist tutvustab enamlevinud lahendusi suurprojektide rahastamiseks ning annab ülevaate projektfinantseerimisega seotud osapooltest, riskidest, finantseerimisvahenditest ning eduka projekti käivitamise eeltingimustest. Lisa: Projektilepingud

  13. Piimatoodangu rekord löödud! / Matti Piirsalu

    Index Scriptorium Estoniae

    Piirsalu, Matti, 1947-

    2005-01-01

    Ülevaade Eesti 2004. aasta piimatoodangust, hindadest, turukorraldusest, riiklikest toetustest. Diagrammid: Piima kogutoodang 2000-2004 a; Piimatoodang lehma kohta 2000-2004 a. Lisa: Vahvaid internetifakte lehmade kohta

  14. Steve Jürvetson muudab maailma / Jaanika Heinsoo

    Index Scriptorium Estoniae

    Heinsoo, Jaanika

    2004-01-01

    Ameerikas elavast eestlasest riskiinvestorist, tema tegevusest infotehnoloogia alal, Eesti rollist infotehnoloogia maailmas, lähituleviku arengutest, iidolitest. Vt. samas intervjuud Steve Jürvetsoniga. Lisa: Steve Jürvetson

  15. Planetaarne mudel ei tööta / Eha Komissarov

    Index Scriptorium Estoniae

    Komissarov, Eha, 1947-

    2005-01-01

    26. Ljubljana graafikabiennaalist "Tõuge/Thrust". Lähemalt ameerika kunstniku Devorah Sperberi tööst "Mona Lisa", Calcografia Nationali (Hispaania) väljapanekust, eestlaste projektist "Jagatud protsess"

  16. Britid tahavad euroliitu põhjalikult muuta / Erkki Bahovski

    Index Scriptorium Estoniae

    Bahovski, Erkki, 1970-

    2005-01-01

    Suurbritannia lükkas Euroopa Liidu eelarvekava tagasi. Riigi konkurentsiminister Barry Gardineri hinnangul tasub põhiseaduse lepingu kriisi ajal alustada arutelu, kuhu liit liigub. Lisa: Barry Gardiner

  17. Ehitusmaterjalitootja laieneb eksporti silmas pidades / Kaisa Tahlfeld

    Index Scriptorium Estoniae

    Tahlfeld, Kaisa

    2007-01-01

    Ilmunud ka: Delovõje Vedomosti 12. dets. lk. 4. Ehitusmaterjalide tootja Krimelte pani nurgakivi tehasele Tallinnas Peterburi maanteel. Diagramm: Majandusnäitajad. Kommenteerib Madis Sagar. Lisa: Krimelte

  18. Eesti oma tuumajaam tulgu aastaks 2025 / Erik Müürsepp

    Index Scriptorium Estoniae

    Müürsepp, Erik

    2008-01-01

    Majandus- ja kommunikatsiooniministeeriumi koostatud arengukavast, milles pakutakse välja rajada Eestisse väiksem tuumaelektrijaam. Diagrammid: Rohkem tuumaenergiat = odavam elekter. Lisa: Leedu jaam küsitav

  19. Tüli õhus / Mihkel Kärmas, Argo Ideon

    Index Scriptorium Estoniae

    Kärmas, Mihkel, 1974-

    2006-01-01

    Lennuameti lennuohutuse eest vastutava asedirektori Rein Porro arvates soovib majandus- ja kommunikatsiooniministeerium temast vabaneda, vastasseisu põhjustest, vastastikustest süüdistustest. Lisa: Porrode lennudünastia

  20. Eesti 1930. aastate lõpu omavalitsusreform tänapäeva omavalitsusväärtuste valguses / Mikk Lõhmus

    Index Scriptorium Estoniae

    Lõhmus, Mikk

    2010-01-01

    Haldusreformi eesmärkidest ja ülesannetest, Eesti halduskorralduse ajalooline ülevaade. Tabelid (Lisa 2: Võrdlev tabel kohaliku omavalitsuse autonoomia ja enesekorraldusõiguse piirangutest 1937. aasta vallaseaduses)

  1. Oligarhid ühendasid jõud maailma vallutamiseks / Erik Aru

    Index Scriptorium Estoniae

    Aru, Erik

    2006-01-01

    Oleg Deripaska ja Viktor Vekselberg sõlmisid mittesiduva kokkuleppe alumiiniumitootjate Rusal ja Sual liitmiseks ning Šveitsi kontserni Glencore alumiiniumiüksuse omandamiseks. Lisa: Deripaska ja Vekselberg

  2. Mees, kes valitses vahendeid valimata / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2003-01-01

    Võimuloleku aja jooksul jõudis Serbia peaminister Zoran Djindjic koguda endale vaenlasi nii poliitiliste vastaste leeris kui ta kuritegelikus maailmas. Tabel: peaministrite tapmisi. Lisa: Dissident, pagulane, filosoof

  3. Is Less Invasive Surfactant Administration Necessary or "Only" Helpful or Just a Fashion?

    Science.gov (United States)

    Lista, Gianluca; Bresesti, Ilia; Fabbri, Laura

    2018-05-01

    In the 1990s, the most relevant pillars in the treatment of neonatal respiratory distress syndrome (RDS) have been improvements in ventilation strategies, the introduction of exogenous surfactant replacement therapy, and the use of antenatal steroids. Lately, in addition to the standard INSURE (INtubation-SURfactant administration-Extubation) method to administer surfactant, a new technique has been gaining increasing popularity. It is the so-called less invasive surfactant administration (LISA) method, which has shown promising results in preventing bronchopulmonary dysplasia development and in reducing mortality in preterm neonates. The rationale behind this technique is to avoid positive pressure ventilation and the endotracheal tube, being surfactant delivered through a thin catheter while the neonate is maintained on continuous positive airway pressure. Given the paucity of large-scale randomized trials on LISA method to prove its effects on short- and long-term outcomes, some questions still remain unanswered. Then, uncertainty regarding the feasibility of this maneuver needs to be better clarified before gaining wide acceptance in routine clinical practice. In our report, we aim at hypothesizing the main mechanisms behind the efficacy of LISA, considering it as a single maneuver in a comprehensive approach for RDS management in the delivery room. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. The Space Technology-7 Disturbance Reduction System Precision Control Flight Validation Experiment Control System Design

    Science.gov (United States)

    O'Donnell, James R.; Hsu, Oscar C.; Maghami, Peirman G.; Markley, F. Landis

    2006-01-01

    As originally proposed, the Space Technology-7 Disturbance Reduction System (DRS) project, managed out of the Jet Propulsion Laboratory, was designed to validate technologies required for future missions such as the Laser Interferometer Space Antenna (LISA). The two technologies to be demonstrated by DRS were Gravitational Reference Sensors (GRSs) and Colloidal MicroNewton Thrusters (CMNTs). Control algorithms being designed by the Dynamic Control System (DCS) team at the Goddard Space Flight Center would control the spacecraft so that it flew about a freely-floating GRS test mass, keeping it centered within its housing. For programmatic reasons, the GRSs were descoped from DRS. The primary goals of the new mission are to validate the performance of the CMNTs and to demonstrate precise spacecraft position control. DRS will fly as a part of the European Space Agency (ESA) LISA Pathfinder (LPF) spacecraft along with a similar ESA experiment, the LISA Technology Package (LTP). With no GRS, the DCS attitude and drag-free control systems make use of the sensor being developed by ESA as a part of the LTP. The control system is designed to maintain the spacecraft s position with respect to the test mass, to within 10 nm/the square root of Hz over the DRS science frequency band of 1 to 30 mHz.

  5. NASA's Gravitational - Wave Mission Concept Study

    Science.gov (United States)

    Stebbins, Robin; Jennrich, Oliver; McNamara, Paul

    2012-01-01

    With the conclusion of the NASA/ESA partnership on the Laser Interferometer Space Antenna (LISA) Project, NASA initiated a study to explore mission concepts that will accomplish some or all of the LISA science objectives at lower cost. The Gravitational-Wave Mission Concept Study consisted of a public Request for Information (RFI), a Core Team of NASA engineers and scientists, a Community Science Team, a Science Task Force, and an open workshop. The RFI yielded were 12 mission concepts, 3 instrument concepts and 2 technologies. The responses ranged from concepts that eliminated the drag-free test mass of LISA to concepts that replace the test mass with an atom interferometer. The Core Team reviewed the noise budgets and sensitivity curves, the payload and spacecraft designs and requirements, orbits and trajectories and technical readiness and risk. The Science Task Force assessed the science performance by calculating the horizons. the detection rates and the accuracy of astrophysical parameter estimation for massive black hole mergers, stellar-mass compact objects inspiraling into central engines. and close compact binary systems. Three mission concepts have been studied by Team-X, JPL's concurrent design facility. to define a conceptual design evaluate kt,y performance parameters. assess risk and estimate cost and schedule. The Study results are summarized.

  6. Koostöö edendamise võimalused Eesti üldhariduskoolides / Anne Aidla

    Index Scriptorium Estoniae

    Aidla, Anne, 1974-

    2004-01-01

    2003. a. Eesti üldhariduskoolides läbi viidud uurimuse tulemustest juhtkonna ja alluvate hinnangute sarnasusest/erinevusest organisatsioonikultuurile ning soovitusi omavahelise koostöö parandamiseks. Lisa lk. 38

  7. Eesti Energia senine juhatus jätkab veel vähemalt aasta / Anneli Ammas, Toivo Tänavsuu

    Index Scriptorium Estoniae

    Ammas, Anneli, 1962-

    2005-01-01

    Eesti Energia nõukogu otsustas jätta ettevõtte juhatuse veel aastaks ametisse, juhikonkursi korraldamise kohta otsust ei langetatud. Nõukogu liikmete kommentaare. Lisa: Eesti Energia kasvatas eksporti

  8. Police chief : homicide down, crime rate constant in 2004 / Aleksei Gunter

    Index Scriptorium Estoniae

    Gunter, Aleksei, 1979-

    2005-01-01

    Politseiameti teatel avastati 2004. aastal rekordarv kuritegusid. Politseiameti peadirektor Robert Antropov politseitööst ja ümberkorraldustest politseis 2004. aastal. Lisa: Politsei prioriteedid 2004 ja 2005 aastal

  9. Abiks algajale ärimehele : Kuidas lüpsta riiki? / Tarmo Vahter

    Index Scriptorium Estoniae

    Vahter, Tarmo, 1970-

    2004-01-01

    Soomes paljastatud asfaldikartell pakub Eesti ettevõtjatele õppetundi, arvab autor. Vaata samas intervjuu Soome konkurentsiameti uurija Kirsi Olaga. Lisa: Konkurents Eesti moodi: vähesed tahtsid Tallinnas ehitada

  10. Serbia ja Montenegro seab eurosihte / Arko Olesk

    Index Scriptorium Estoniae

    Olesk, Arko, 1981-

    2005-01-01

    Eestis visiidil viibinud Serbia ja Montenegro asevälisminister Predrad Boskovici hinnangul kavatseb riik liituda Euroopa Liiduga, selle suurimaks takistuseks on suutmatus sõjakurjategijate tabamisel. Lisa: Serbia areng

  11. Turunduse meistriklass / Philip Kotler ; interv. Stuart Crainer

    Index Scriptorium Estoniae

    Kotler, Philip

    2004-01-01

    Turunduse rollist ettevõtte tegevuses, Interneti ja kommunikatsioonitehnoloogiate mõjust turunduse arengule, kliendisuhete haldamisest ning ettevõtte sotsiaalsest vastutusest. Lisa: Turunduse ees seisavad paljud suured väljakutsed

  12. Leviv HI-viirus suurendab Eestis tuberkuloosiohtu / Agnes Kuus

    Index Scriptorium Estoniae

    Kuus, Agnes

    2005-01-01

    Põhja-Eesti Regionaalhaigla tuberkuloosiregistri juhataja Vahur Hollo tõdes, et tuberkuloosiga nakatanute koguarvu on keeruline määrata, sest suur osa viirusekandjaist ei haigestu kunagi. Lisa: Tuberkuloos

  13. Põhja-Korea lubas taas jätta tuumaplaanid / Jürgen Tamme

    Index Scriptorium Estoniae

    Tamme, Jürgen

    2007-01-01

    Pekingis toimunud kuuepoolsete desarmeerimiskõneluste tulemusena on Põhja-Korea nõus andma ülevaate riigi tuumarajatistest ning alustama nende likvideerimist. 14. juulil suleti Yongbyoni tuumakeskuse reaktor. Lisa: Tuumavaidlus

  14. "Kas Lavrenti Pavlovitsh Beria - poliitbüroo liige - ei olegi siis partei?" : ääremärkusi L. Beria "uuele kursile" vastupanuliikumise mahasurumisel 1953. aasta kevadel / Tõnu Tannberg

    Index Scriptorium Estoniae

    Tannberg, Tõnu, 1961-

    2005-01-01

    Vastupanuliikumisvastase võitluse meetodite ja taktika muutumisest L. Beria juhtimisel NSV Liidus. Lisa: Repressioonide ulatus Balti liiduvabariikides ja Ukrainas aastatel 1944-1953 L. Beria märgukirjade alusel

  15. Michael Bloomberg ähvardab USA valimised "ära rikkuda" / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2008-01-01

    New Yorgi praegune linnapea Michael Bloomberg võib kolmanda kandidaadina sekkuda presidendikandidaatide valimiskampaaniasse, probleem on aga tema vähene tuntus. Lisa: Seni on riigipeakoha jaganud kaks suurparteid

  16. Parteid lubavad valimiste eel pealinlastele toetusi / Urmas Seaver

    Index Scriptorium Estoniae

    Seaver, Urmas, 1973-

    2005-01-01

    Erakonnad lubavad valimiste eel pealinlastele uusi soodustusi - alanevat maamaksu, lastehoiuraha, toetusi lastele ja pensionäridele. Näiteks Reformierakond lubab maamaksu alandada kaks korda. Lisa: Erakonnad peibutavad soodustustega

  17. Communication and advertising top agency now in Baltics / Ingrid Nielsen

    Index Scriptorium Estoniae

    Nielsen, Ingrid

    2004-01-01

    Baltimaade turule tulnud Euroopa juhtiva reklaami- ja kommunikatsiooniagentuuri Media Planning Group juht Kaspars Ulsts ettevõtte tegevusest ja eesmärkidest. Lisa: MPG's biggest clients; Background of MPG

  18. Prantsuse maaklerile pannakse süüks miljardite tuulde laskmist / Liisi Poll

    Index Scriptorium Estoniae

    Poll, Liisi, 1980-

    2008-01-01

    Ilmunud ka: Postimees : na russkom jazõke 28. jaan. 2008, lk. 6. Prantsusmaa suurpanga Societe Generale maakler Jerome Kerviel tekitas lubamatute pangatehingutega pangale viiemiljardilise kahju. Lisa: Kuulsaid pangakaotusi

  19. Baltic Property Trust - professionaalseim kinnisvara investeerimisfirma Baltimere piirkonnas

    Index Scriptorium Estoniae

    2005-01-01

    BPT Eesti direktor Meelis Liivak Baltic Property Trusti (BPT) eesmärkidest, tegevusvaldkondadest ja tulevikuplaanidest. Kommenteerivad Alo Kullamaa, Priit Põldoja, Andres Järving ja Aivar Tomson. Lisa: Ajalugu

  20. Maksumoraal maksukuulekuse mõjutajana / Kerly Lillemets

    Index Scriptorium Estoniae

    Lillemets, Kerly, 1974-

    2007-01-01

    Maksumoraali ja maksukuulekuse kujunemisest, seosest demokraatia arengu, väärtushinnangute ja haridusega, näited Euroopast ja Ameerika Ühendriikidest. Lisa: Maksudega nõustumise mõjurite klassifikatsioon

  1. Vene riik paneb suure osa nafta hinna tõusust enda taskusse / Annika Matson

    Index Scriptorium Estoniae

    Matson, Annika, 1976-

    2004-01-01

    Tulevikus kahaneb Vene naftagigantide kasum, kuna riik maksustab eksporditava nafta kasumi kuni 90 protsendiga. Vt. samas: Aleksander Malugin. Venemaa metallisektor õitseb. Lisa: Investeerimispankade lemmikud Venemaa börsil

  2. Migrantide raha hoiab vee peal suurt osa endisest NL-ist / Ahto Lobjakas

    Index Scriptorium Estoniae

    Lobjakas, Ahto, 1970-

    2007-01-01

    Brüsselis tutvustatud Maailmapanga uuringust, mille kohaselt on suure osa endise NSVL-i vabariikide jaoks arvestatav sissetulekuallikas migrantide kojusaadetud raha. Lisa: Lääne-Euroopasse ja Venemaale

  3. ÜRO süüdistab USA-d piinamises ja nõuab Guantanamo laagri sulgemist / Krister Paris

    Index Scriptorium Estoniae

    Paris, Krister, 1977-

    2006-01-01

    ÜRO inimõiguste komisjoni esindajad uurisid Guantanamo vanglast vabanenutelt, nende advokaatidelt ja arstidelt vangide kohtlemist Guantanamos. Uurimise raportist. Lisa: Vanglat aitavad täita pearahakütid

  4. The year of evolution for 2002 / Tim Ferland

    Index Scriptorium Estoniae

    Ferland, Tim

    2003-01-01

    Eesti-Ameerika Kaubandus-Tööstuskoja liikmed on esimese tegutsemisaastaga rahul. Aktiivselt osaleti NATO Baltimaadesse laienemise diskussioonides. Lisa: Eesti sai kutse ühineda NATO-ga 21. novembril 2002

  5. Globaalsed sündmused mõjutavad ka Eestit / Lauri Tabur

    Index Scriptorium Estoniae

    Tabur, Lauri, 1974-

    2002-01-01

    Autor analüüsib Eesti julgeolekukeskkonda nelja riskikategooria kaudu - sõjaline risk, poliitilise surve risk, majanduslik risk ja uued julgeolekuriskid. Lisa: terrorismi tunnustega sündmused Eestis

  6. Kongress andis Bushile sõja jätkamiseks raha / Igor Taro

    Index Scriptorium Estoniae

    Taro, Igor

    2007-01-01

    USA demokraatide kontrollitav esindajatekoda kinnitas 555 miljardi dollari suuruse riigieelarve, andes sellega 70 miljardit dollarit juurde ka Iraagi ja Afganistani sõja pidamiseks. Lisa: Kulukas Iraagi sõda

  7. Kunda puitmassitehase ehitus võib alata / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2003-01-01

    Norra kapitalil põhineval firmal Estonian Cell on kõik load Kundasse haavapuitmassitehase rajamiseks. Ehitus algab 2004. aasta alguses, selle kestuseks on planeeritud poolteist aastat. Lisa: Estonian Cell

  8. The democratic experience in divided societies : the Baltic states in comparative perspective / Geoffrey Evans, Christine S Lipsmeyer

    Index Scriptorium Estoniae

    Evans, Geoffrey

    2001-01-01

    Artiklis võrreldakse vähemusrahvuste rahulolu demokratiseerimisprotsessiga ning osalemist demokraatlikes protsessides kolmes Balti riigis ning kümnes Ida-Euroopa riigis 1990. aastail. Tabelid. Lisa: The surveys

  9. How costly is it for the Bank of Latvia to support a credible peg? / Viktors Stebunovs

    Index Scriptorium Estoniae

    Stebunovs, Viktors

    2001-01-01

    Kuna Läti lati fikseeritud kursi toetamine on Läti panga jaoks üsna kulukas, vaadeldakse alternatiivseid võimalusi kursi hoidmiseks - vahetuskurss, katteta intressipariteet ja turusurve indeks. Lisa

  10. Maksuarvestuse muudatused nõuavad muutuste tegemist majandustarkvaras / Hanna Dunning, Jelena Abaimova

    Index Scriptorium Estoniae

    Dunning, Hanna

    2003-01-01

    Alates 2005. aastast on Euroopa Ühenduse väärtpaberiturgudel noteeritud ettevõtted kohustatud raamatupidamisaruandluse koostama vastavalt IAS-ile (International Accounting Standards). Lisa: IASi kasutuselevõtul arvesta

  11. Russia puts Europe to a test of morality / Vytautas Landsbergis ; interv. Sven Becker

    Index Scriptorium Estoniae

    Landsbergis, Vytautas

    2006-01-01

    Euroopa Parlamendi liige vastab küsimustele, mis puudutavad Leedut Euroopa Liidu liikmesriigina, Euroopa Liidu ja Venemaa suhteid, Vene-Saksa gaasitoru ja Leedu sisepoliitikat. Lisa: Vytautas Landsbergise CV

  12. Hansapank võib luua uue kodulaenude tütarpanga / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2007-01-01

    Hansapank uurib võimalust tõsta eluasemelaenud eraldi tütarpanka, mis tegeleks rahvusvaheliselt võlakirjaturgudelt raha hankimisega ning kodulaenude väljastamisega. Lisa: Rootsi kodulaenupank Swedbank Mortgage

  13. Investeerija märksõnad : USA ning tervishoiu- ja IT-sektor / Uwe Zöllner

    Index Scriptorium Estoniae

    Zöllner, Uwe

    2008-01-01

    USA elanike tarbimise mõjust globaalsele majandusruumile. Aktsiainvesteeringuid plaanides tasuks silmas pidada tervishoiu- ja infotehnoloogiasektori ettevõtteid ning vaadata USA poole. Lisa: Hiina eksport võrreldes riigisisese tarbimisega

  14. Vadim Kotelnikovi tugevus on loovus / Marjatta Pietilä

    Index Scriptorium Estoniae

    Pietilä, Marjatta

    2004-01-01

    E-coaching teenuseid pakkuvast ülemaailmsest ettevõtete ketist TEN3, firmast Centre for Entrepreneurial Creativity and Systemic Innovation ning nende loojast majandusdoktor Vadim Kotelnikovist. Lisa: Vadim Kotelnikov

  15. Eesti parandas kohta rahvusvahelises korruptsioonitajumise indeksi tabelis / Andris Feldmanis

    Index Scriptorium Estoniae

    Feldmanis, Andris, 1982-

    2005-01-01

    Rahvusvahelise korruptsioonivastase organisatsiooni Transparency International avaldatud 2005. aasta korruptsioonitajumise indeksi tabelis on Eesti 27. kohal, mis on meile parim tulemus alates 1998. aastast. Lisa: Transparency International. 2005. aasta tabel

  16. Trigon Capital sukeldub Ukraina piimaärisse / Airi Ilisson

    Index Scriptorium Estoniae

    Ilisson, Airi, 1980-

    2005-01-01

    Investeerimisfirma Trigon Capital valis uueks investeeringute sihiks Ukraina piimatööstuse muutunud poliitilise kliima ja piimatöökvootide puudumise tõttu. Lisa: Kinnisvara. Horvaatia kinnisvaraäri

  17. Nokia tuleb ühes muusikaga / Kersti Saar

    Index Scriptorium Estoniae

    Saar, Kersti

    2008-01-01

    Nokia plaanib avada uut teenust Comes with Music, mis avab kliendile ligipääsu suurimate plaadifirmade Universal Music Croupi muusikakataloogidele. Diagramm: Nokia aktsia hind. Lisa: Comes with Music

  18. Eestlased teevad igavast Laumast moetööstuse tipptegijat / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2005-01-01

    Eesti investeerimisfirma Alta Capital omandas 2004. aasta kevadel enamuse Läti kanga- ja pesutootja AS-i Lauma aktsiatest. Ettevõtte arengust ja tulevikuplaanidest. Lisa: Pesumood muutub erootilisemaks. Diagrammid: Lauma

  19. Marketing directors earning up to EUR 30K per annum / Ingrid Nielsen

    Index Scriptorium Estoniae

    Nielsen, Ingrid

    2004-01-01

    Eesti personalifirma Baltic Human Resources konsultant Kaja Kaldas ja Fontes Konsultatsioonide konsultant Eva Lelumees reklaami- ja turundusspetsialistide vajadusest ettevõtetes, üldisest kompetentsuse tasemest ja palkadest Eestis. Lisa: Statistics

  20. Serblaste vabariigi alistanud horvaat Haagi tribunali ees / Heiki Suurkask

    Index Scriptorium Estoniae

    Suurkask, Heiki, 1972-

    2005-01-01

    Horvaatia kindral Ante Gotovina kinnitas Haagi sõjatribunalis, et pole sõjakuritegudes süüdi. Horvaatias tõi kindrali vahistamine kaasa massilise protestilaine. Lisa: Horvaatia erukindral Ante Gotovina

  1. Perspektivõ sotrudnitshestva i konkurentsii portov Baltiiskogo regiona = Cooperation and competition prospects for the ports in the Baltic region / Mihhail Bronshtein

    Index Scriptorium Estoniae

    Bronštein, Mihhail, 1923-

    2004-01-01

    11-12. oktoobrini Peterburis toimunud konverentsil peetud ettekanne. Eesti Teaduste Akadeemia akadeemik Balti riikide sadamate tähtsusest Venemaa transiitkaubanduses, Venemaa sadamate ehitusest Balti mere regioonis. Lisa: Mihhail Bronshtein

  2. Sotsiaalne vastutus Eesti moodi : firma maksab, omanik võtab aupaiste? / Külliki Tafel, Ruth Alas

    Index Scriptorium Estoniae

    Tafel, Külliki

    2006-01-01

    Väljavõtteid intervjuudest, mis viidi läbi Estonian Business Schooli ja Tuleviku-uuringute Instituudi poolt korraldatud sotsiaalse vastutuse uuringu raames. Lisa: EBSi ja Tuleviku-uuringute Instituudi uuring

  3. Uus turunduskangelane SMS / Merit Raju

    Index Scriptorium Estoniae

    Raju, Merit

    2002-01-01

    Lühisõnum SMS (Short Message Service) ja multimeediasõnum MMS (Multimedia Messaging System) - uued võimalused reklaami edastamiseks klientidele. Kommenteerib Henri Österlund. Lisa: SMS-reklaami võimalused

  4. Spordikaupade müüjad müttavad riski piiril / Andres Reimer

    Index Scriptorium Estoniae

    Reimer, Andres

    2005-01-01

    Majandusliku olukorra halvenemine võib kaasa tuua spordikaupluste pankrotilaine. Ülevaade Eesti kolme suurima spordikaupluste keti Sportland, Rademar ja Hawaii Express tegevusest. Lisa: Hinnad. Tabel: Eesti suurimaid spordikaupade kette

  5. Uuring : Eesti autostumisel on Lääne-Euroopaga võrreldes palju arenguruumi

    Index Scriptorium Estoniae

    2007-01-01

    Autostumisest Eestis ja Euroopa Liidu liikmesriikides, Euroopa Komisjoni poolt tellitud Eurobaromeetri uuringu tulemustest. Lisa: 2006. aastal esmaregistreeriti Eestis kokku 74 212 sõiduautot, aasta varem 60 626 sõiduautot.

  6. Ekseko Orins a Huge Amount of "Pure Gold" / Toivo Tänavsuu

    Index Scriptorium Estoniae

    Tänavsuu, Toivo

    2004-01-01

    Seakasvatusfirmast Ekseko AS - kõige konkurentsivõimelisemast ettevõttest põllu- ja metsamajandusettevõtete hulgas. Kavatsusest hakata sõnnikust elektrit tootma. Tabel: Põllu- ja metsamajandusettevõtted. Lisa: Ekseko 2003

  7. Farmide rajamiseks tuleb EList Eestisse 170 miljonit krooni / Ain Alvela

    Index Scriptorium Estoniae

    Alvela, Ain, 1967-

    2009-01-01

    12.-26. oktoobrini 2009 saavad loomapidajad esitada Põllumajanduse Registrite ja Informatsiooni Ametile (PRIA) taotlusi investeeringutoetuse saamiseks loomakasvatusehitiste rajamiseks ja neisse vajalike seadmete soetamiseks. Lisa: toetus peab kindlustama konkurentsivõimet

  8. Poles plan defense of RKN Orlen from hostile bid

    Index Scriptorium Estoniae

    2007-01-01

    Poola majandusministeerium arendab plaani Leedu naftatöötlustehase Mazeikiu Nafta omaniku PKN Orleni kaitsmiseks võimalike Vene firmade vaenulike ülevõtmispakkumiste eest. Lisa. Divert from Eastern Europe?

  9. Briti kodanikud pääsevad koju Guantanamost / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2005-01-01

    USA valmistub nelja Afganistani sõjas osalenud Guantanamo baasis kinni hoitava Suurbritannia kodaniku üleandmiseks kodumaale. Lisa: Paarsada vangi on koju saadetud. Vt. samas: Guantanamo vangilaager asub justkui eikellegimaal

  10. Naiste nappus kasvatab India ja Hiina ühiskondades vägivaldset käitumist / Arko Olesk

    Index Scriptorium Estoniae

    Olesk, Arko, 1981-

    2006-01-01

    Poisslapsi eelistav traditsioon on viinud meeste suure ülekaaluni Hiina ja India rahvastikus ning toidab kuritegevuse ja terrorismi kasvu. Ühe lapse poliitika. Lisa: Kas teate. Naiste osakaal rahvastikus

  11. Pagunitega kurjategijad : nõukogude sõjaväelaste kriminaalkuritegevus Eestis sõjajärgsetel aastatel / Tiit Noormets

    Index Scriptorium Estoniae

    Noormets, Tiit, 1959-

    2005-01-01

    Lisa: Valgamaa NKVD ja NKGB juhtide ettekanne siseasjade rahvakomissar Resevile 7.-8. nov. 1945 Valgas toimunud intsidendi kohta ; Sõjaväelaste poolt sooritatud iseloomulikud kuriteod 1946. aasta I kvartalis

  12. Tänavu sünnib ligi 300 last rohkem kui mullu / Mirko Ojakivi

    Index Scriptorium Estoniae

    Ojakivi, Mirko

    2005-01-01

    Demograafilistest protsessidest Eestis lõppeval aastal. TÜ inimgeograafia õppetooli vanemteaduri Tiit Tammaru prognoose lähitulevikuks. Lisa: Rummo rõõmustab edasimineku üle. Graafik: Ligi 300 last enam

  13. Noorteühenduste kogu tutvustab Euroopa Liitu / Jaanika Meier

    Index Scriptorium Estoniae

    Meier, Jaanika

    2007-01-01

    Tartu Noorteühenduste Kogu tutvustab projekti "Kodanikuna Euroopa Liidus. Eile. Täna. Homme" noortele Euroopa Liitu, selle toimemehhanisme, arengusuundi ja liidus noortele pakutavaid võimalusi. Lisa: Kas teate

  14. Teadlased panevad paika kaugete esivanemate rännutee / Madis Filippov

    Index Scriptorium Estoniae

    Filippov, Madis

    2008-01-01

    Ajakirja National Geographic ja arvutifirma IBM algatatud ülemaailmsest teadusuuringust "Genographic", milles osalevad teadlased korraldasid oma iga-aastase konverentsi sedapuhku Eestis. Lisa: Postimehe ajakirjaniku Risto Berendsoni põlvnemise lugu

  15. 2008. aastal keskenduti e-teenuste arendamisele : [2008. aasta rahvaraamatukogudes keskraamatukogude aruannete põhjal, tulevikuplaanides] / Meeli Veskus

    Index Scriptorium Estoniae

    Veskus, Meeli, 1953-

    2009-01-01

    Sisaldab ka: Raamatukogude kasutamine, lugejad ja kogud / Margit Jõgi. Lisa: Lugejateenindus ja kogud üldkasutatavates rahvaraamatukogudes 2008 : [joonised] / Margit Jõgi. Milline oli olukord rahvaraamatukogudes 2009. aasta algul? / Ene Riet.

  16. 76 FR 14392 - GeoLogics Corporation; Transfer of Data

    Science.gov (United States)

    2011-03-16

    ... these chemicals. LISA also maintains EPA inspection findings, the identity of the inspection team, and... in accordance with the FIFRA Information Security Manual. In addition, GeoLogics Corporation is...

  17. 75 FR 58435 - Membership of the Senior Executive Service Standing Performance Review Boards

    Science.gov (United States)

    2010-09-24

    ..., ROBERT N ASSOCIATE DEPUTY ATTORNEY GENERAL MONACO, LISA ASSOCIATE DEPUTY ATTORNEY GENERAL BURROWS... GENERAL MASON, KAROL V DEPUTY ASSOCIATE ATTORNEY GENERAL TRIBE, LARRY H SENIOR COUNSELOR FOR ACCESS TO...

  18. City bans unsuitable project years later / Kairi Kurm

    Index Scriptorium Estoniae

    Kurm, Kairi

    2005-01-01

    Tallinna Linnavalitsus keelas Viru hotelli laienemise Tammsaare parki. Linnapea Tõnis Palts on ka kõrghoonete ehitamise vastu Pirita jõe ümbrusesse. Lisa: Inimeste arvamus hotelli laienemise keelamise kohta

  19. Moskvas algab tagaselja protsess Berezovski üle / Igor Taro

    Index Scriptorium Estoniae

    Taro, Igor

    2007-01-01

    Vene poliitemigranti, Suurbritanniast asüüli palunud Boriss Berezovskit süüdistatakse lennukompaniist Aeroflot 214 miljoni rubla varastamises ning rahapesus, kriminaalasja eelistung algab juulis. Lisa: Aerofloti saaga

  20. Angela Merkel : NATO kaitseb Eestit Gruusia sündmuste kordumise eest / Raimo Poom

    Index Scriptorium Estoniae

    Poom, Raimo

    2008-01-01

    Saksamaa liidukantsleri Angela Merkeli visiit keskendus olukorrale Gruusias: kantsler taunis Venemaa otsust tunnistada Lõuna-Osseetia ja Abhaasia iseseisvust ning arvustas Venemaa venitamistaktikat rahuplaani elluviimisel. Lisa: Gruusiale viisalihtsustus ja abi