Sample records for noise suppression systems

  1. Noise suppressing capillary separation system

    DOE Patents [OSTI]

    Yeung, E.S.; Xue, Y.

    1996-07-30T23:59:59.000Z

    A noise-suppressing capillary separation system for detecting the real-time presence or concentration of an analyte in a sample is provided. The system contains a capillary separation means through which the analyte is moved, a coherent light source that generates a beam which is split into a reference beam and a sample beam that irradiate the capillary, and a detector for detecting the reference beam and the sample beam light that transmits through the capillary. The laser beam is of a wavelength effective to be absorbed by a chromophore in the capillary. The system includes a noise suppressing system to improve performance and accuracy without signal averaging or multiple scans. 13 figs.

  2. Suppression and enhancement of transcriptional noise by DNA looping

    E-Print Network [OSTI]

    Jose M. G. Vilar; Leonor Saiz

    2014-06-11T23:59:59.000Z

    DNA looping has been observed to enhance and suppress transcriptional noise but it is uncertain which of these two opposite effects is to be expected for given conditions. Here, we derive analytical expressions for the main quantifiers of transcriptional noise in terms of the molecular parameters and elucidate the role of DNA looping. Our results rationalize paradoxical experimental observations and provide the first quantitative explanation of landmark individual-cell measurements at the single molecule level on the classical lac operon genetic system [Choi et al., Science 322, 442-446 (2008)].

  3. Explosion suppression system

    DOE Patents [OSTI]

    Sapko, Michael J. (Finleyville, PA); Cortese, Robert A. (Pittsburgh, PA)

    1992-01-01T23:59:59.000Z

    An explosion suppression system and triggering apparatus therefor are provided for quenching gas and dust explosions. An electrically actuated suppression mechanism which dispenses an extinguishing agent into the path ahead of the propagating flame is actuated by a triggering device which is light powered. This triggering device is located upstream of the propagating flame and converts light from the flame to an electrical actuation signal. A pressure arming device electrically connects the triggering device to the suppression device only when the explosion is sensed by a further characteristic thereof beside the flame such as the pioneer pressure wave. The light powered triggering device includes a solar panel which is disposed in the path of the explosion and oriented between horizontally downward and vertical. Testing mechanisms are also preferably provided to test the operation of the solar panel and detonator as well as the pressure arming mechanism.

  4. Analysis of Shot Noise Suppression for Electron Beams

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

    Ratner, Daniel; Huang, Zhirong; Stupakov, Gennady

    2015-02-02T23:59:59.000Z

    Shot noise can affect the performance of free-electron lasers (FELs) by driving instabilities (e.g., the microbunching instability) or by competing with seeded density modulations. Recent papers have proposed suppressing shot noise to enhance FEL performance. In this paper we use a onedimensional (1D) model to calculate the noise amplification from an energy modulation (e.g., electron interactions from space charge or undulator radiation) followed by a dispersive section. We show that, for a broad class of interactions, selecting the correct dispersive strength suppresses shot noise across a wide range of frequencies. The final noise level depends on the beam’s energy spread and the properties of the interaction potential. We confirm and illustrate our analytical results with 1D simulations.

  5. Pressure suppression containment system

    DOE Patents [OSTI]

    Gluntz, D.M.; Townsend, H.E.

    1994-03-15T23:59:59.000Z

    A pressure suppression containment system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The wetwell pool includes a plenum for receiving the non-condensable gas carried with steam from the drywell following a loss-of-coolant-accident (LOCA). The wetwell plenum is vented to a plenum above the GDCS pool following the LOCA for suppressing pressure rise within the containment vessel. A method of operation includes channeling steam released into the drywell following the LOCA into the wetwell pool for cooling along with the non-condensable gas carried therewith. The GDCS pool is then drained by gravity, and the wetwell plenum is vented into the GDCS plenum for channeling the non-condensable gas thereto. 6 figures.

  6. Pressure suppression containment system

    DOE Patents [OSTI]

    Gluntz, Douglas M. (San Jose, CA); Townsend, Harold E. (San Jose, CA)

    1994-03-15T23:59:59.000Z

    A pressure suppression containment system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The wetwell pool includes a plenum for receiving the non-condensable gas carried with steam from the drywell following a loss-of coolant-accident (LOCA). The wetwell plenum is vented to a plenum above the GDCS pool following the LOCA for suppressing pressure rise within the containment vessel. A method of operation includes channeling steam released into the drywell following the LOCA into the wetwell pool for cooling along with the non-condensable gas carried therewith. The GDCS pool is then drained by gravity, and the wetwell plenum is vented into the GDCS plenum for channeling the non-condensable gas thereto.

  7. Pressure suppression system

    DOE Patents [OSTI]

    Gluntz, D.M.

    1994-10-04T23:59:59.000Z

    A pressure suppression system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and an enclosed gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The GDCS pool includes a plenum for receiving through an inlet the non-condensable gas carried with steam from the drywell following a loss-of-coolant accident (LOCA). A condenser is disposed in the GDCS plenum for condensing the steam channeled therein and to trap the non-condensable gas therein. A method of operation includes draining the GDCS pool following the LOCA and channeling steam released into the drywell following the LOCA into the GDCS plenum for cooling along with the non-condensable gas carried therewith for trapping the gas therein. 3 figs.

  8. Pressure suppression system

    DOE Patents [OSTI]

    Gluntz, Douglas M. (San Jose, CA)

    1994-01-01T23:59:59.000Z

    A pressure suppression system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and an enclosed gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The GDCS pool includes a plenum for receiving through an inlet the non-condensable gas carried with steam from the drywell following a loss-of-coolant accident (LOCA). A condenser is disposed in the GDCS plenum for condensing the steam channeled therein and to trap the non-condensable gas therein. A method of operation includes draining the GDCS pool following the LOCA and channeling steam released into the drywell following the LOCA into the GDCS plenum for cooling along with the non-condensable gas carried therewith for trapping the gas therein.

  9. Quadrature mixture LO suppression via DSW DAC noise dither

    DOE Patents [OSTI]

    Dubbert, Dale F. (Cedar Crest, NM); Dudley, Peter A. (Albuquerque, NM)

    2007-08-21T23:59:59.000Z

    A Quadrature Error Corrected Digital Waveform Synthesizer (QECDWS) employs frequency dependent phase error corrections to, in effect, pre-distort the phase characteristic of the chirp to compensate for the frequency dependent phase nonlinearity of the RF and microwave subsystem. In addition, the QECDWS can employ frequency dependent correction vectors to the quadrature amplitude and phase of the synthesized output. The quadrature corrections cancel the radars' quadrature upconverter (mixer) errors to null the unwanted spectral image. A result is the direct generation of an RF waveform, which has a theoretical chirp bandwidth equal to the QECDWS clock frequency (1 to 1.2 GHz) with the high Spurious Free Dynamic Range (SFDR) necessary for high dynamic range radar systems such as SAR. To correct for the problematic upconverter local oscillator (LO) leakage, precision DC offsets can be applied over the chirped pulse using a pseudo-random noise dither. The present dither technique can effectively produce a quadrature DC bias which has the precision required to adequately suppress the LO leakage. A calibration technique can be employed to calculate both the quadrature correction vectors and the LO-nulling DC offsets using the radar built-in test capability.

  10. Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image

    E-Print Network [OSTI]

    Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image of Mathematics, National Taiwan University, Taipei, Taiwan, 4 Elekta Oy, Helsinki, Finland Abstract Ultra-low. (2013) Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image

  11. Submitted to Trans. Circuits and Systems I Wideband CMOS Low Noise Amplifier Design

    E-Print Network [OSTI]

    Southern California, University of

    Submitted to Trans. Circuits and Systems I Wideband CMOS Low Noise Amplifier Design Based On Source for wideband CMOS low noise amplifier (LNA) with source degener- ation is presented. By allowing an arbitrary in the design of the LNA is to achieve sufficiently large gain and low noise figure to suppress the additive

  12. Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump

    E-Print Network [OSTI]

    Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump A. Fisch Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 and Department of Astrophysical Laser pulse compression­amplification through Raman backscattering in plasmas can be facilitated

  13. Optimal noise suppression in Fresnel incoherent correlation holography (FINCH) configured for

    E-Print Network [OSTI]

    Rosen, Joseph

    Optimal noise suppression in Fresnel incoherent correlation holography (FINCH) configured 131543); published 14 October 2010 An optimal setup in the sense of imaging resolution for the Fresnel of America OCIS codes: 090.1995, 030.6140, 110.4280. 1. Introduction Fresnel incoherent correlation

  14. Feedback suppression of rotating external kink instabilities in the presence of noise

    SciTech Connect (OSTI)

    Hanson, Jeremy M.; De Bono, Bryan; James, Royce W.; Levesque, Jeffrey P.; Mauel, Michael E.; Maurer, David A.; Navratil, Gerald A.; Pedersen, Thomas Sunn; Shiraki, Daisuke [Applied Physics and Applied Mathematics, Columbia University, 200 S. W. Mudd Building - MC 4701, 500 W. 120th Street, New York, New York 10027 (United States)

    2008-08-15T23:59:59.000Z

    The authors report on the first experimental demonstration of active feedback suppression of rotating external kink modes near the ideal wall limit in a tokamak using Kalman filtering to discriminate the n=1 kink mode from background noise. The Kalman filter contains an internal model that captures the dynamics of a rotating, growing n=1 mode. Suppression of the external kink mode is demonstrated over a broad range of phase angles between the sensed mode and applied control field, and performance is robust at noise levels that render proportional gain feedback ineffective. Suppression of the kink mode is accomplished without excitation of higher frequencies as was observed in previous experiments using lead-lag loop compensation [A. J. Klein et al., Phys Plasmas 12, 040703 (2005)].

  15. Suppressing the influence of additive noise on the Kalman gain for low residual noise speech enhancement

    E-Print Network [OSTI]

    present a detailed analysis of the Kalman filter for the application of speech enhancement and identify: Kalman filtering; Speech enhancement; Linear prediction; Dolph-Chebycher windows 1. Introduction In the problem of speech enhancement, where a speech signal corrupted by noise is given, we are primarily

  16. Johnson Noise Thermometry System Requirements

    SciTech Connect (OSTI)

    Britton Jr, Charles L [ORNL; Roberts, Michael [ORNL; Ezell, N Dianne Bull [ORNL; Qualls, A L [ORNL; Holcomb, David Eugene [ORNL

    2013-01-01T23:59:59.000Z

    This document is intended to capture the requirements for the architecture of the developmental electronics for the ORNL-lead drift-free Johnson Noise Thermometry (JNT) project conducted under the Instrumentation, Controls, and Human-Machine Interface (ICHMI) research pathway of the U.S. Department of Energy (DOE) Advanced Small Modular Reactor (SMR) Research and Development (R&D) program. The requirements include not only the performance of the system but also the allowable measurement environment of the probe and the allowable physical environment of the associated electronics. A more extensive project background including the project rationale is available in the initial project report [1].

  17. Scanning probe microscopy with inherent disturbance suppression using micromechanical systems

    E-Print Network [OSTI]

    Sparks, Andrew William, 1977-

    2005-01-01T23:59:59.000Z

    All scanning probe microscopes (SPMs) are affected by disturbances, or mechanical noise, in their environments which can limit their imaging resolution. This thesis introduces a general approach for suppressing out-of-plane ...

  18. Noise suppression in reconstruction of low-Z target megavoltage cone-beam CT images

    SciTech Connect (OSTI)

    Wang Jing; Robar, James; Guan Huaiqun [Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas 75235 (United States); Departments of Radiation Oncology and Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H1V7 (Canada); Department of Radiation Oncology, Saint Vincent Hospital, Worcester, Massachusetts 01608 (United States)

    2012-08-15T23:59:59.000Z

    Purpose: To improve the image contrast-to-noise (CNR) ratio for low-Z target megavoltage cone-beam CT (MV CBCT) using a statistical projection noise suppression algorithm based on the penalized weighted least-squares (PWLS) criterion. Methods: Projection images of a contrast phantom, a CatPhan{sup Registered-Sign} 600 phantom and a head phantom were acquired by a Varian 2100EX LINAC with a low-Z (Al) target and low energy x-ray beam (2.5 MeV) at a low-dose level and at a high-dose level. The projections were then processed by minimizing the PWLS objective function. The weighted least square (WLS) term models the noise of measured projection and the penalty term enforces the smoothing constraints of the projection image. The variance of projection data was chosen as the weight for the PWLS objective function and it determined the contribution of each measurement. An anisotropic quadratic form penalty that incorporates the gradient information of projection image was used to preserve edges during noise reduction. Low-Z target MV CBCT images were reconstructed by the FDK algorithm after each projection was processed by the PWLS smoothing. Results: Noise in low-Z target MV CBCT images were greatly suppressed after the PWLS projection smoothing, without noticeable sacrifice of the spatial resolution. Depending on the choice of smoothing parameter, the CNR of selected regions of interest in the PWLS processed low-dose low-Z target MV CBCT image can be higher than the corresponding high-dose image.Conclusion: The CNR of low-Z target MV CBCT images was substantially improved by using PWLS projection smoothing. The PWLS projection smoothing algorithm allows the reconstruction of high contrast low-Z target MV CBCT image with a total dose of as low as 2.3 cGy.

  19. Performance Limitations of Linear Systems over Additive White Noise Channels

    E-Print Network [OSTI]

    Li, Yiqian

    2011-01-01T23:59:59.000Z

    Control over additive white noise channels . . . . . . . 1.3Additive white noise channel . . . . . . . . . . . . . . Angaussian systems over additive gaussian wireles fading

  20. Observation of modulation speed enhancement, frequency modulation suppression, and phase noise reduction by detuned loading in a coupled-cavity semiconductor laser

    SciTech Connect (OSTI)

    Vahala, K.; Paslaski, J.; Yariv, A.

    1985-06-01T23:59:59.000Z

    Simultaneous direct modulation response enhancement, phase noise (linewidth) reduction, and frequency modulation suppression are produced in a coupled-cavity semiconductor laser by the detuned loading mechanism.

  1. Fire Foe: A Glovebox Fire Suppression System | Department of...

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

    Envirogel Extinguishing Agent NRTL Qualification Fire Test Proof-of-Concept Testing Seismic Reliability Fire Foe: A Glovebox Fire Suppression System More Documents &...

  2. Active noise canceling system for mechanically cooled germanium radiation detectors

    DOE Patents [OSTI]

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22T23:59:59.000Z

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  3. Noise study of the digital seismic system amplifiers applied to earth noise measurements

    SciTech Connect (OSTI)

    Valk, D.

    1982-08-31T23:59:59.000Z

    Some major noise problems afflicting the Digital Seismic System are briefly examined for the purpose of improving the signal-to-noise ratio for earth noise measurements. After concluding that the Tustin Electronics Co. 1560 instrumentation amplifiers presently being used in the system obscure the earth noise data, a comprehensive study (part experimental and part theoretical) of amplifier noise is performed. Noise curves in the approximate frequency range of 0.01 to 50 Hz for the Tustin amplifiers as well as for a new design based on the PMI SSS725 operational amplifier are experimentally determined. The curves, which include noise current and noise voltage densities as well as total noise, are compared to each other, and to the Peterson low earth noise curve. The comparisons are done with amplifier inputs shorted, connected to one and then two 500-..cap omega.. seismometer data coils, and connected to one 20-k..cap omega.. seismometer data coil. The total noise curve of the new amplifier is found to shift further below that of the Tustin amplifier as data coil resistance is increased. A goal of lowering amplifier noise 10 dB or more below the Peterson earth noise power density curve for frequencies greater than .03 Hz is desired. The new amplifier design, used in conjunction with a 20-k..cap omega.. data coil, is found to satisfy this 10 dB or more signal-to-noise ratio for earth noise measurements. It is also found that the difference between earth noise and new amplifier noise magnitudes is increased as data coil resistance is increased.

  4. Enabling Green Energy and Propulsion Systems via Direct Noise...

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

    GE propulsion systems Enabling Green Energy and Propulsion Systems via Direct Noise Computation PI Name: Umesh Paliath PI Email: paliath@ge.com Institution: GE Global Research...

  5. Enabling Green Energy and Propulsion Systems via Direct Noise...

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

    Umesh Paliath, GE Global Research; Joe Insley, Argonne National Laboratory Enabling Green Energy and Propulsion Systems via Direct Noise Computation PI Name: Umesh Paliath PI...

  6. Occupant Classification System for Automotive Airbag Suppression Michael E. Farmer

    E-Print Network [OSTI]

    Occupant Classification System for Automotive Airbag Suppression Michael E. Farmer§ and Anil K@cse.msu.edu Abstract The introduction of airbags into automobiles has significantly improved the safety of the occupants. Unfortunately, airbags can also cause fatal injuries if the occupant is a child smaller (in

  7. Electrical noise control in e-beam processing systems

    SciTech Connect (OSTI)

    Gunn, R. [Lawrence Livermore National Lab., CA (United States)

    1996-12-31T23:59:59.000Z

    Electrical noise can be a problem in any system. The risk rises when the system contains an energetic noise source like an e-beam. Relief is more certain when facts about noise propagation are fresh in mind and this is a practical over-view of just these things. Though known singly by technical people, these effects are now brought together and related to one another. This discussion cites the practical importance of skin effect, conductor self-inductance, and the four coupling mechanisms including the justly feared conductively coupled {open_quotes}ground loop{close_quotes}. A look at the valuable yet inexpensive single Faraday-shield transformer leads to system concepts like incidental returns and the often overlooked need for intentional noise-abatement conductors. The wrap-up addresses practical matters like noise propagation through power wiring, followed by specific suggestions and examples of system layouts that inherently avoid harmful noise couplings.

  8. Circuit for echo and noise suppression of acoustic signals transmitted through a drill string

    DOE Patents [OSTI]

    Drumheller, D.S.; Scott, D.D.

    1993-12-28T23:59:59.000Z

    An electronic circuit for digitally processing analog electrical signals produced by at least one acoustic transducer is presented. In a preferred embodiment of the present invention, a novel digital time delay circuit is utilized which employs an array of First-in-First-out (FiFo) microchips. Also, a bandpass filter is used at the input to this circuit for isolating drill string noise and eliminating high frequency output. 20 figures.

  9. Feasibility and design of blast mitigation systems for naval applications using water mist fire suppression systems

    E-Print Network [OSTI]

    Kitchenka, Julie A

    2004-01-01T23:59:59.000Z

    The recent trend of using fine water mist systems to replace the legacy HALON- 1301 fire suppression systems warrants further study into other applications of the water mist systems. Preliminary research and investigation ...

  10. Turbo Receiver Design for Phase Noise Mitigation in OFDM Systems

    E-Print Network [OSTI]

    Sridharan, Gokul

    2010-01-01T23:59:59.000Z

    This paper addresses the issue of phase noise in OFDM systems. Phase noise (PHN) is a transceiver impairment resulting from the non-idealities of the local oscillator. We present a case for designing a turbo receiver for systems corrupted by phase noise by taking a closer look at the effects of the common phase error (CPE). Using an approximate probabilistic framework called variational inference (VI), we develop a soft-in soft-out (SISO) algorithm that generates posterior bit-level soft estimates while taking into account the effect of phase noise. The algorithm also provides an estimate of the phase noise sequence. Using this SISO algorithm, a turbo receiver is designed by passing soft information between the SISO detector and an outer forward error correcting (FEC) decoder that uses a soft decoding algorithm. It is shown that the turbo receiver achieves close to optimal performance.

  11. Pressure suppression containment system for boiling water reactor

    DOE Patents [OSTI]

    Gluntz, D.M.; Nesbitt, L.B.

    1997-01-21T23:59:59.000Z

    A system is disclosed for suppressing the pressure inside the containment of a BWR following a postulated accident. A piping subsystem is provided which features a main process pipe that communicates the wetwell airspace to a connection point downstream of the guard charcoal bed in an offgas system and upstream of the main bank of delay charcoal beds which give extensive holdup to offgases. The main process pipe is fitted with both inboard and outboard containment isolation valves. Also incorporated in the main process pipe is a low-differential-pressure rupture disk which prevents any gas outflow in this piping whatsoever until or unless rupture occurs by virtue of pressure inside this main process pipe on the wetwell airspace side of the disk exceeding the design opening (rupture) pressure differential. The charcoal holds up the radioactive species in the noncondensable gas from the wetwell plenum by adsorption, allowing time for radioactive decay before the gas is vented to the environs. 3 figs.

  12. Pressure suppression containment system for boiling water reactor

    DOE Patents [OSTI]

    Gluntz, Douglas M. (San Jose, CA); Nesbitt, Loyd B. (San Jose, CA)

    1997-01-01T23:59:59.000Z

    A system for suppressing the pressure inside the containment of a BWR following a postulated accident. A piping subsystem is provided which features a main process pipe that communicates the wetwell airspace to a connection point downstream of the guard charcoal bed in an offgas system and upstream of the main bank of delay charcoal beds which give extensive holdup to offgases. The main process pipe is fitted with both inboard and outboard containment isolation valves. Also incorporated in the main process pipe is a low-differential-pressure rupture disk which prevents any gas outflow in this piping whatsoever until or unless rupture occurs by virtue of pressure inside this main process pipe on the wetwell airspace side of the disk exceeding the design opening (rupture) pressure differential. The charcoal holds up the radioactive species in the noncondensable gas from the wetwell plenum by adsorption, allowing time for radioactive decay before the gas is vented to the environs.

  13. The Impact of System Design Parameters on Application Noise Sensitivity

    E-Print Network [OSTI]

    Bridges, Patrick

    by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National. In this paper, we examine the impact of three such system properties: platform balance, "noisy" node the sensitivity of ap- plications to OS noise: · The hardware balance of the system, the ra- tio of peak network

  14. Amplifiers Module Prototype for the Johnson Noise Thermometry System

    SciTech Connect (OSTI)

    Britton Jr, Charles L [ORNL; Bull, Nora D [ORNL; Roberts, Michael [ORNL

    2013-06-01T23:59:59.000Z

    This document is intended to summarize the development and testing of the amplifier module portion of the Johnson Noise Thermometry (JNT) system developed at ORNL. The proposed system has been presented in an earlier report [1]. A more extensive project background including the project rationale is available in the initial project report [2].

  15. Dry low combustion system with means for eliminating combustion noise

    DOE Patents [OSTI]

    Verdouw, Albert J.; Smith, Duane; McCormick, Keith; Razdan, Mohan K.

    2004-02-17T23:59:59.000Z

    A combustion system including a plurality of axially staged tubular premixers to control emissions and minimize combustion noise. The combustion system includes a radial inflow premixer that delivers the combustion mixture across a contoured dome into the combustion chamber. The axially staged premixers having a twist mixing apparatus to rotate the fluid flow and cause improved mixing without causing flow recirculation that could lead to pre-ignition or flashback.

  16. Exact results for a noise-induced bistable system

    E-Print Network [OSTI]

    Houchmandzadeh, Bahram

    2015-01-01T23:59:59.000Z

    A stochastic system where bistability is caused by noise has been recently investigated by Bian-calani et al. (PRL 112:038101, 2014). They have computed the mean switching time for such a system using the system size approximation and the continuous Fokker-Planck equation as a tool to estimate the parameter of such a system from experiment. In this article, we provide the exact solution for the full discrete system without resorting to continuous approximation and obtain the expression for the mean switching time. We further extend this investigation by solving exactly the Master equation and obtaining the expression of other quantities of interests such as the dynamics of the moments and the equilibrium time. The method we develop here is general and can be applied to other stochastic systems.

  17. Theoretical Modeling Issue in Active Noise Control for a One-Dimensional Acoustic Duct System

    E-Print Network [OSTI]

    Yang, Zhenyu

    Theoretical Modeling Issue in Active Noise Control for a One-Dimensional Acoustic Duct System-6700 Esbjerg, Denmark Email: yang,sp@aaue.dk Abstract--The theoretical modeling of active noise control for the entire one-dimensional active duct noise control system is obtained and validated. The developed model

  18. Method and system for modulation of gain suppression in high average power laser systems

    DOE Patents [OSTI]

    Bayramian, Andrew James (Manteca, CA)

    2012-07-31T23:59:59.000Z

    A high average power laser system with modulated gain suppression includes an input aperture associated with a first laser beam extraction path and an output aperture associated with the first laser beam extraction path. The system also includes a pinhole creation laser having an optical output directed along a pinhole creation path and an absorbing material positioned along both the first laser beam extraction path and the pinhole creation path. The system further includes a mechanism operable to translate the absorbing material in a direction crossing the first laser beam extraction laser path and a controller operable to modulate the second laser beam.

  19. Suppression of Quantum Scattering in Strongly Confined Systems

    SciTech Connect (OSTI)

    Kim, J. I. [Departamento de Pesquisas, Altanova, R. Silva Teles 712, CEP 03026-000, Bras, Sa(tilde sign)o Paulo, SP, Brasil (Brazil); Melezhik, V. S. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Moscow Region 141980 (Russian Federation); Schmelcher, P. [Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany); Theoretische Chemie, Institut fuer Physikalische Chemie, Universitaet Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg (Germany)

    2006-11-10T23:59:59.000Z

    We demonstrate that scattering of particles strongly interacting in three dimensions (3D) can be suppressed at low energies in a quasi-one-dimensional (1D) confinement. The underlying mechanism is the interference of the s- and p-wave scattering contributions with large s- and p-wave 3D scattering lengths being a necessary prerequisite. This low-dimensional quantum scattering effect might be useful in 'interacting' quasi-1D ultracold atomic gases, guided atom interferometry, and impurity scattering in strongly confined quantum wire-based electronic devices.

  20. A semiclassical theory of quantum noise in open chaotic systems

    E-Print Network [OSTI]

    B. C. Bag; S. Chaudhuri; J. Ray Chaudhuri; D. S. Ray

    1998-11-13T23:59:59.000Z

    We consider the quantum evolution of classically chaotic systems in contact with surroundings. Based on $\\hbar$-scaling of an equation for time evolution of the Wigner's quasi-probability distribution function in presence of dissipation and thermal diffusion we derive a semiclassical equation for quantum fluctuations. This identifies an early regime of evolution dominated by fluctuations in the curvature of the potential due to classical chaos and dissipation. A stochastic treatment of this classical fluctuations leads us to a Fokker-Planck equation which is reminiscent of Kramers' equation for thermally activated processes. This reveals an interplay of three aspects of evolution of quantum noise in weakly dissipative open systems; the reversible Liouville flow, the irreversible chaotic diffusion which is characteristic of the system itself, and irreversible dissipation induced by the external reservoir. It has been demonstrated that in the dissipation-free case a competition between Liouville flow in the contracting direction of phase space and chaotic diffusion sets a critical width in the Wigner function for quantum fluctuations. We also show how the initial quantum noise gets amplified by classical chaos and ultimately equilibrated under the influence of dissipation. We establish that there exists a critical limit to the expansion of phase space. The limit is determined by chaotic diffusion and dissipation. Making use of appropriate quantum-classical correspondence we verify the semiclassical analysis by the fully quantum simulation in a chaotic quartic oscillator.

  1. The Availability of Logical Operation Induced by Dichotomous Noise for a Nonlinear Bistable System

    E-Print Network [OSTI]

    Yong Xu; Xiaoqin Jin; Huiqing Zhang; Tingting Yang

    2013-09-04T23:59:59.000Z

    Instead of a continuous system driven by Gaussian white noise, logical stochastic resonance will be investigated in a nonlinear bistable system with two thresholds driven by dichotomous noise, which shows a phenomenon different from Gaussian white noise. We can realize two parallel logical operations by simply adjusting the values of these two thresholds. Besides, to quantify the reliability of obtaining the correct logic output, we numerically calculate the success probability, and effects of dichotomous noise on the success probability are observed, these observations show that the reliability of realizing logical operation in the bistable system can be improved through optimizing parameters of dichotomous noise.

  2. Investigating Operating System Noise in Extreme-Scale High-Performance Computing Systems using Simulation

    SciTech Connect (OSTI)

    Engelmann, Christian [ORNL

    2013-01-01T23:59:59.000Z

    Hardware/software co-design for future-generation high-performance computing (HPC) systems aims at closing the gap between the peak capabilities of the hardware and the performance realized by applications (application-architecture performance gap). Performance profiling of architectures and applications is a crucial part of this iterative process. The work in this paper focuses on operating system (OS) noise as an additional factor to be considered for co-design. It represents the first step in including OS noise in HPC hardware/software co-design by adding a noise injection feature to an existing simulation-based co-design toolkit. It reuses an existing abstraction for OS noise with frequency (periodic recurrence) and period (duration of each occurrence) to enhance the processor model of the Extreme-scale Simulator (xSim) with synchronized and random OS noise simulation. The results demonstrate this capability by evaluating the impact of OS noise on MPI_Bcast() and MPI_Reduce() in a simulated future-generation HPC system with 2,097,152 compute nodes.

  3. Biologically-based signal processing system applied to noise removal for signal extraction

    DOE Patents [OSTI]

    Fu, Chi Yung; Petrich, Loren I.

    2004-07-13T23:59:59.000Z

    The method and system described herein use a biologically-based signal processing system for noise removal for signal extraction. A wavelet transform may be used in conjunction with a neural network to imitate a biological system. The neural network may be trained using ideal data derived from physical principles or noiseless signals to determine to remove noise from the signal.

  4. A proposed system to automatically control audio sound-to-noise levels

    E-Print Network [OSTI]

    Neinast, Gary Strickland

    1957-01-01T23:59:59.000Z

    the human ear is stimulated by vibrating particles of a1r, sound is sensed. If this sound is undesired, it isp by definition, noise. Any sound that is irx'egular, impulsive, non-repetitive, or simply irri, tating to the listenez' may be classified..., applause, or laughter in theaters; motor or wind noise in moving vehicles] or the noise of people dancing. The level or the souroe ef noise was unimportant sinoe the oontrol system would hold the sound-to-noise level approximately constant. Fox' design...

  5. PPPL extends system for suppressing instabilities to long-pulse...

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

    instabilities will be vital for future fusion facilities such as ITER, the huge international project under construction in France. The original system developed on...

  6. Optimized pulse sequences for suppressing unwanted transitions in quantum systems

    SciTech Connect (OSTI)

    Schroeder, C. A.; Agarwal, G. S. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St. Norman, Oklahoma 73019 (United States); Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

    2011-01-15T23:59:59.000Z

    We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. 98, 100504 (2007)] in the context of inhibition of environmental dephasing effects is optimal. We derive exact results for inhibiting the transitions and confirm the results numerically. We posit a very significant improvement by usage of the Uhrig sequence over an equidistant sequence in decoupling a quantum system from unwanted transitions. The physics of inhibition is the destructive interference between transition amplitudes before and after each pulse.

  7. Decomposing Noise in Biochemical Signaling Systems Highlights the Role of Protein Degradation

    E-Print Network [OSTI]

    Miekisz, Jacek

    Decomposing Noise in Biochemical Signaling Systems Highlights the Role of Protein Degradation Micha degradation on the overall variability for a range of molecular processes and signaling systems. With our are able to show how regulated protein degradation can be employed to reduce the noise in biochem- ical

  8. Methods And System Suppressing Clutter In A Gain-Block, Radar-Responsive Tag System

    DOE Patents [OSTI]

    Ormesher, Richard C. (Albuquerque, NM); Axline, Robert M. (Albuquerque, NM)

    2006-04-18T23:59:59.000Z

    Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radar systems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radar system.

  9. Memorandum, Managed Phase Out of Halon Fixed Fire Suppression Systems- May 5, 1993

    Broader source: Energy.gov [DOE]

    The purpose of this memorandum is to provide additional interim departmental criteria on the management of the reduction and potential elimination of Halon fire extinguishing systems within the Department of Energy (DOE). This memorandum supplements the joint Office of Safety and Quality Assurance/Office of Projects and Facilities Management memorandum of September 27, 1990, in which guidance was provided on the installation of new Halon 1301 fixed fire suppression systems and halon 1211 portable fire extinguishers.

  10. Dual-mode self-validating resistance/Johnson noise thermometer system

    DOE Patents [OSTI]

    Shepard, Robert L. (Oak Ridge, TN); Blalock, Theron V. (Knoxville, TN); Roberts, Michael J. (Knoxville, TN)

    1993-01-01T23:59:59.000Z

    A dual-mode Johnson noise and DC resistance thermometer capable of use in control systems where prompt indications of temperature changes and long term accuracy are needed. A resistance-inductance-capacitance (RLC) tuned circuit produces a continuous voltage signal for Johnson noise temperature measurement. The RLC circuit provides a mean-squared noise voltage that depends only on the capacitance used and the temperature of the sensor. The sensor has four leads for simultaneous coupling to a noise signal processor and to a DC resistance signal processor.

  11. Generation and Suppression of Decoherence in Artificial Environment for Qubit System

    E-Print Network [OSTI]

    Yasushi Kondo; Mikio Nakahara; Shogo Tanimura; Sachiko Kitajima; Chikako Uchiyama; Fumiaki Shibata

    2007-02-10T23:59:59.000Z

    It is known that a quantum system with finite degrees of freedom can simulate a composite of a system and an environment if the state of the hypothetical environment is randomized by external manipulation. We show theoretically that any phase decoherence phenomena of a single qubit can be simulated with a two-qubit system and demonstrate experimentally two examples: one is phase decoherence of a single qubit in a transmission line, and the other is that in a quantum memory. We perform NMR experiments employing a two-spin molecule and clearly measure decoherence for both cases. We also prove experimentally that the bang-bang control efficiently suppresses decoherence.

  12. Award ER25844: Minimizing System Noise Effects for Extreme-Scale Scientific Simulation Through Function Delegation

    SciTech Connect (OSTI)

    Lumsdaine, Andrew

    2012-11-20T23:59:59.000Z

    In software running on distributed computing clusters, time spent on communication between nodes in the cluster can be a significant portion of the overall computation time; background operating system tasks and other computational ?noise? on the nodes of the system can have a significant impact on the amount of time this communication takes, especially on large systems. The research completed in this period has improved understanding of when such noise will have a significant impact. Specifically, it was demonstrated that not just noise on the nodes, but also noise on the network between nodes can have a significant impact on computation time. It was also demonstrated that noise patterns matter more than noise intensity: very regular noise can cause less disruption than lighter (on average) but less regular noise. It was also demonstrated that the effect of noise is more prominent as the speed of the network between nodes is increased. Furthermore, a tracing tool, Netgauge, was improved via our work, and a system simulator, LogGOPSim, was developed; they can be used by application developers to improve performance of their program and by system designers to mitigate the effects of noise by adjusting the noise characteristics of the operating system. Both have been made freely available as open source programs. In the course of developing these tools, we demonstrated weaknesses in existing methodologies for modeling communication, and we introduced a more detailed model, LogGOPS, for simulating systems. Not only were the deleterious effects of noise explored but we have also offered solutions. Our studies of simulations of system noise have led to specific recommendations on tuning systems to mitigate noise. We have also improved existing approaches to mitigating noise. ?Non-blocking collective communication? avoids the effects of noise by letting communication continue simultaneously with computation (thus being ?non-blocking?), so that the delays in communication introduced by noise have a smaller impact on overall computation time. Potentially, noise can be reduced much further by ?offloading? communication tasks to a separate processing element than the operating system is using. We have improved our library LibNBC, which provides an implementation of non-blocking collectives, via this work. During this research, our proposal to include non-blocking collectives (which used LibNBC as a reference implementation) in the upcoming MPI-3 standard was accepted. As MPI is a ubiquitous and important standard for communication in parallel computing, this demonstrates a certain acceptance of the practicality and desirability of non-blocking collectives. Now that non-blocking collectives are a part of the standard we can expect to see optimized platform-specific implementations of non-blocking collectives. Also as part of this work we have also developed a language GOAL (Global Operation Assembly Language) that can be used as a starting point for defining languages to express optimized communication algorithms.

  13. A proposed system to automatically control audio sound-to-noise levels 

    E-Print Network [OSTI]

    Neinast, Gary Strickland

    1957-01-01T23:59:59.000Z

    A PROPOSED SYSTEM TO AUTOMATICALLY CONTROL AUDIO SOUND TO NOISE LEVELS A Thesis ~ ]3y GARY 8% NEINAST Submitted to the Graduate Sohool of the Agrioultural and Meohanioal College of Texas in partial fulfillment of the requirements...

  14. NO.sub.x catalyst and method of suppressing sulfate formation in an exhaust purification system

    DOE Patents [OSTI]

    Balmer-Millar, Mari Lou (Chillicothe, IL); Park, Paul W. (Peoria, IL); Panov, Alexander G. (Peoria, IL)

    2007-06-26T23:59:59.000Z

    The activity and durability of a zeolite lean-burn NOx catalyst can be increased by loading metal cations on the outer surface of the zeolite. However, the metal loadings can also oxidize sulfur dioxide to cause sulfate formation in the exhaust. The present invention is a method of suppressing sulfate formation in an exhaust purification system including a NO.sub.x catalyst. The NO.sub.x catalyst includes a zeolite loaded with at least one metal. The metal is selected from among an alkali metal, an alkaline earth metal, a lanthanide metal, a noble metal, and a transition metal. In order to suppress sulfate formation, at least a portion of the loaded metal is complexed with at least one of sulfate, phosphate, and carbonate.

  15. System and method that suppresses intensity fluctuations for free space high-speed optical communication

    DOE Patents [OSTI]

    Berman, Gennady P. (Los Alamos, NM); Bishop, Alan R. (Los Alamos, NM); Nguyen, Dinh C. (Los Alamos, NM); Chernobrod, Boris M. (Santa Fe, NM); Gorshkov, Vacheslav N. (Kiev, UA)

    2009-10-13T23:59:59.000Z

    A high-speed (Gbps), free space optical communication system is based on spectral encoding of radiation from a wide band light source, such as a laser. By using partially coherent laser beams in combination with a relatively slow photosensor, scintillations can be suppressed by orders of magnitude for distances of more than 10 km. To suppress the intensity fluctuations due to atmospheric turbulence, a source with partial transverse coherence in combination with slow response time photodetector is used. Information is encoded in the spectral domain of a wideband optical source by modulation of spectral amplitudes. A non-coherent light source with wide spectrum (an LED, for example) may be used for high-speed communication over short (less than about a mile) distances.

  16. Experimental results of water film formation on various fuel forms from a fire suppression system

    SciTech Connect (OSTI)

    Ross, R.H.; Davis, J.R.

    1994-12-31T23:59:59.000Z

    The purpose of the study was to determine the thickness and coverage of water film formations on various materials during fire sprinkler deluge. The primary criticality safety concern with automatic fire suppression systems is the increased amount of water that a film adds to the interstitial volume of an array per unit time. An exhaustive literature search revealed that no applicable research data exist that govern water film formations from fire protection systems. Therefore, a controlled, infield, mockup was created to predict the thickness and coverage of water film on fissile material forms. This paper discusses the background, experimental procedure, and the characterization of these water films.

  17. Geant4 Model Validation of Compton Suppressed System for Process monitoring of Spent Fuel

    SciTech Connect (OSTI)

    Bender, Sarah; Unlu, Kenan; Orton, Christopher R.; Schwantes, Jon M.

    2013-05-01T23:59:59.000Z

    Nuclear material accountancy is of continuous concern for the regulatory, safeguards, and verification communities. In particular, spent nuclear fuel reprocessing facilities pose one of the most difficult accountancy challenges: monitoring highly radioactive, fluid sample streams in near real-time. The Multi-Isotope Process monitor will allow for near-real-time indication of process alterations using passive gamma-ray detection coupled with multivariate analysis techniques to guard against potential material diversion or to enhance domestic process monitoring. The Compton continuum from the dominant 661.7 keV 137Cs fission product peak obscures lower energy lines which could be used for spectral and multivariate analysis. Compton suppression may be able to mitigate the challenges posed by the high continuum caused by scattering. A Monte Carlo simulation using the Geant4 toolkit is being developed to predict the expected suppressed spectrum from spent fuel samples to estimate the reduction in the Compton continuum. Despite the lack of timing information between decay events in the particle management of Geant4, encouraging results were recorded utilizing only the information within individual decays without accounting for accidental coincidences. The model has been validated with single and cascade decay emitters in two steps: as an unsuppressed system and with suppression activated. Results of the Geant4 model validation will be presented.

  18. System and method for motor fault detection using stator current noise cancellation

    DOE Patents [OSTI]

    Zhou, Wei (Los Angeles, CA); Lu, Bin (Kenosha, WI); Nowak, Michael P. (Menomonee Falls, WI); Dimino, Steven A. (Wauwatosa, WI)

    2010-12-07T23:59:59.000Z

    A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to acquire at least on additional set of real-time operating current data from the motor during operation, redefine the noise component present in each additional set of real-time operating current data, and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

  19. Effectiveness of two spraying systems for bollworm suppression, canopy penetration, and drift reduction in the Rolling Plains of Texas

    E-Print Network [OSTI]

    Robinson, John Robert Calvert

    1986-01-01T23:59:59.000Z

    EFFECTIVENESS OF TWO SPRAYING SYSTEMS FOR BOLLWORM SUPPRESSION, CANOPY PENETRATION, AND DRIFT REDUCTION IN THE ROLLING PLAINS OF TEXAS A Thesis by JOHN ROBERT CALVERT ROBINSON Submitted to the Graduate College of Texas A8B University... in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE May 1986 Major Subject: Entomology EFFECTIVENESS OF TWO SPRAYING SYSTEMS FOR BOLLWORM SUPPRESSION, CANOPY PENETRATION, AND DRIFT REDUCTION IN THE ROLLING PLAINS OF TEXAS A...

  20. On the Failure of Power System Automatic Generation Control due to Measurement Noise

    E-Print Network [OSTI]

    Liberzon, Daniel

    understood, the electric grid could become more vulnerable to failures in both cyber and physical components-level automatic closed-loop control system over the IT infrastructure of a power system [1], is sensitive1 On the Failure of Power System Automatic Generation Control due to Measurement Noise Jiangmeng

  1. Development of NS-TACSR with extremely suppressed aeolian noise and its application to 500 kV overhead transmission lines

    SciTech Connect (OSTI)

    Tsujimoto, K.; Furukawa, S. (Kansai Electric Power Co., Inc., Osaka (Japan)); Shimojima, K.; Yamamoto, K. (Hitachi Cable, Ltd., Hitachi (JP))

    1991-10-01T23:59:59.000Z

    Recently in Japan, with the unprecedented advance of residential area development in the suburbs of large cities, it has become quite difficult to secure the routes of EHV transmission lines from nuclear power plants in remote places to the suburbs of large cities, urging resolution of environmental problems related to transmission lines. In Japan, aerodynamic sound produced by conductors and insulators frequently caused noise problems. Having an opportunity of constructing a 500 kV transmission line through a residential are, we made a research to resolve this noise problem. This paper describes the characteristics of aeolian noise and preventive measures against it.

  2. Statistical model based iterative reconstruction (MBIR) in clinical CT systems: Experimental assessment of noise performance

    SciTech Connect (OSTI)

    Li, Ke; Tang, Jie [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)

    2014-04-15T23:59:59.000Z

    Purpose: To reduce radiation dose in CT imaging, the statistical model based iterative reconstruction (MBIR) method has been introduced for clinical use. Based on the principle of MBIR and its nonlinear nature, the noise performance of MBIR is expected to be different from that of the well-understood filtered backprojection (FBP) reconstruction method. The purpose of this work is to experimentally assess the unique noise characteristics of MBIR using a state-of-the-art clinical CT system. Methods: Three physical phantoms, including a water cylinder and two pediatric head phantoms, were scanned in axial scanning mode using a 64-slice CT scanner (Discovery CT750 HD, GE Healthcare, Waukesha, WI) at seven different mAs levels (5, 12.5, 25, 50, 100, 200, 300). At each mAs level, each phantom was repeatedly scanned 50 times to generate an image ensemble for noise analysis. Both the FBP method with a standard kernel and the MBIR method (Veo{sup ®}, GE Healthcare, Waukesha, WI) were used for CT image reconstruction. Three-dimensional (3D) noise power spectrum (NPS), two-dimensional (2D) NPS, and zero-dimensional NPS (noise variance) were assessed both globally and locally. Noise magnitude, noise spatial correlation, noise spatial uniformity and their dose dependence were examined for the two reconstruction methods. Results: (1) At each dose level and at each frequency, the magnitude of the NPS of MBIR was smaller than that of FBP. (2) While the shape of the NPS of FBP was dose-independent, the shape of the NPS of MBIR was strongly dose-dependent; lower dose lead to a “redder” NPS with a lower mean frequency value. (3) The noise standard deviation (?) of MBIR and dose were found to be related through a power law of ????(dose){sup ??} with the component ? ? 0.25, which violated the classical ????(dose){sup ?0.5} power law in FBP. (4) With MBIR, noise reduction was most prominent for thin image slices. (5) MBIR lead to better noise spatial uniformity when compared with FBP. (6) A composite image generated from two MBIR images acquired at two different dose levels (D1 and D2) demonstrated lower noise than that of an image acquired at a dose level of D1+D2. Conclusions: The noise characteristics of the MBIR method are significantly different from those of the FBP method. The well known tradeoff relationship between CT image noise and radiation dose has been modified by MBIR to establish a more gradual dependence of noise on dose. Additionally, some other CT noise properties that had been well understood based on the linear system theory have also been altered by MBIR. Clinical CT scan protocols that had been optimized based on the classical CT noise properties need to be carefully re-evaluated for systems equipped with MBIR in order to maximize the method's potential clinical benefits in dose reduction and/or in CT image quality improvement.

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

    E-Print Network [OSTI]

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

    2007-11-23T23:59:59.000Z

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

  4. Minimizing System Noise Effects For Extreme-Scale Scientific Simulation Through Function Delegation

    SciTech Connect (OSTI)

    Dongarra, Jack J. [University of Tennessee, Knoxville; Bosilca, George [University of Tennessee, Knoxville

    2013-06-11T23:59:59.000Z

    The primary goal of the Minimizing System Noise Effects For Extreme-Scale Scientific Simulation through Function Delegation project is to eliminate or at best strongly minimize the impact of the noise introduced by the operating system, during large scale parallel applications runs. Collective communication operations are a basic building block for parallel programing models and scientific applications. These operations often dominate execution time of applications and tend to limit their scalability. In order to address this challenge, we evaluated different strategies to adapt the collective communications underlying topologies to the hardware architecture in order to provide increased levels of performance to the parallel applications.

  5. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    SciTech Connect (OSTI)

    Cho, Gyuseong

    1992-03-01T23:59:59.000Z

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was {approximately}400 MHz and the noise charge {approximately}1000 electrons at a 1 {mu}sec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of {approximately}0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  6. System and method for bearing fault detection using stator current noise cancellation

    SciTech Connect (OSTI)

    Zhou, Wei (Los Angeles, CA); Lu, Bin (Kenosha, WI); Habetler, Thomas G. (Snellville, GA); Harley, Ronald G. (Lawrenceville, GA); Theisen, Peter J. (West Bend, WI)

    2010-08-17T23:59:59.000Z

    A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to repeatedly receive real-time operating current data from the operating motor and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

  7. Kalman filtering to suppress spurious signals in Adaptive Optics control

    SciTech Connect (OSTI)

    Poyneer, L; Veran, J P

    2010-03-29T23:59:59.000Z

    In many scenarios, an Adaptive Optics (AO) control system operates in the presence of temporally non-white noise. We use a Kalman filter with a state space formulation that allows suppression of this colored noise, hence improving residual error over the case where the noise is assumed to be white. We demonstrate the effectiveness of this new filter in the case of the estimated Gemini Planet Imager tip-tilt environment, where there are both common-path and non-common path vibrations. We discuss how this same framework can also be used to suppress spatial aliasing during predictive wavefront control assuming frozen flow in a low-order AO system without a spatially filtered wavefront sensor, and present experimental measurements from Altair that clearly reveal these aliased components.

  8. Noise and vibration for a self-excited mechanical system with friction

    E-Print Network [OSTI]

    Boyer, Edmond

    Noise and vibration for a self-excited mechanical system with friction K. Soobbarayen1,a , S. The contact is modelled by introducing several local contact elements at the friction interface and a cubic contact law is used to describe the contact force. The classical Coulomb law is applied to model friction

  9. Noise filtering in a multi-channel system using a tunable liquid crystal photonic bandgap fiber

    E-Print Network [OSTI]

    Wu, Shin-Tson

    fiber used as a tunable filter in an optical transmission system. The device allows low-cost amplified spontaneous emission (ASE) noise filtering and gain equalization with low insertion loss and broad tunability. M. de Sterke, "Application of an ARROW model for designing tunable photonic devices," Opt. Express

  10. Readout process and noise elimination firmware for the Fermilab beam loss system

    SciTech Connect (OSTI)

    Wu, Jinyuan; Baumbaugh, Alan; Drennan, Craig; Thurman-Keup, Randy; Lewis, Jonathan; Shi, Zonghan; /Fermilab

    2007-05-01T23:59:59.000Z

    In the Fermilab Beam Loss Monitor System, inputs from ion chambers are integrated for a short period of time, digitized and processed to create the accelerator abort request signals. The accelerator power supplies employing 3-phase 60Hz AC cause noise at various harmonics on our inputs which must be eliminated for monitoring purposes. During accelerator ramping, both the sampling frequency and the amplitudes of the noise components change. As such, traditional digital filtering can partially reduce certain noise components but not all. A nontraditional algorithm was developed in our work to eliminate remaining ripples. The sequencing in the FPGA firmware is conducted by a micro-sequencer core we developed: the Enclosed Loop Micro-Sequencer (ELMS). The unique feature of the ELMS is that it supports the ''FOR'' loops with pre-defined iterations at the machine code level, which provides programming convenience and avoids many micro-complexities from the beginning.

  11. Signal processing method and system for noise removal and signal extraction

    DOE Patents [OSTI]

    Fu, Chi Yung (San Francisco, CA); Petrich, Loren (Lebanon, OR)

    2009-04-14T23:59:59.000Z

    A signal processing method and system combining smooth level wavelet pre-processing together with artificial neural networks all in the wavelet domain for signal denoising and extraction. Upon receiving a signal corrupted with noise, an n-level decomposition of the signal is performed using a discrete wavelet transform to produce a smooth component and a rough component for each decomposition level. The n.sup.th level smooth component is then inputted into a corresponding neural network pre-trained to filter out noise in that component by pattern recognition in the wavelet domain. Additional rough components, beginning at the highest level, may also be retained and inputted into corresponding neural networks pre-trained to filter out noise in those components also by pattern recognition in the wavelet domain. In any case, an inverse discrete wavelet transform is performed on the combined output from all the neural networks to recover a clean signal back in the time domain.

  12. The Dynamics of Bistable Switching Behavior in Limit Cycle Systems with Additive Noise

    E-Print Network [OSTI]

    Michael A. Schwemmer; Jay M. Newby

    2015-01-23T23:59:59.000Z

    Additive noise is known to produce counter-intuitive behaviors in nonlinear dynamical systems. Previously, it was shown that systems with a deterministic limit cycle can display bistable switching between metastable states in the presence of asymmetric additive white noise. Here, we systematically analyze the dynamics of this bistable behavior and show how the vector field away from the limit cycle influences the rate and directionality of the bistable switching. Using stochastic phase reduction methods, we identify mechanisms underlying different rates of switching and predict when the system will rotate in the opposite direction of the deterministic limit cycle. Thus, this work presents an alternative mechanism for generating a range of bistable switch-like behaviors that have been observed in a number of physical systems.

  13. Generalized Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system using arbitrary resistors

    E-Print Network [OSTI]

    Vadai, Gergely; Gingl, Zoltan

    2015-01-01T23:59:59.000Z

    The Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchange system has been introduced as a simple, very low cost and efficient classical physical alternative to quantum key distribution systems. The ideal system uses only a few electronic components - identical resistor pairs, switches and interconnecting wires - to guarantee perfectly protected data transmission. We show that a generalized KLJN system can provide unconditional security even if it is used with significantly less limitations. The more universal conditions ease practical realizations considerably and support more robust protection against attacks. Our theoretical results are confirmed by numerical simulations.

  14. Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

    SciTech Connect (OSTI)

    Qiu, Haodong; Wang, Hong, E-mail: ewanghong@ntu.edu.sg [NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Ke, Feixiang [Temasek Laboratories at Nanyang Technological University, Research Techno Plaza, Singapore 637553 (Singapore)

    2014-06-23T23:59:59.000Z

    The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

  15. Ear-Phone: An End-to-End Participatory Urban Noise Mapping System

    E-Print Network [OSTI]

    New South Wales, University of

    noise pollution. Wireless sensor networks can certainly eliminate the requirements of sending acoustic monitoring of environmental noise pollution in urban areas. It can raise citizen awareness of noise pollution devices, also addresses the challenge of collecting accurate noise pollution readings at a mobile device

  16. End-to-End Models for Effects of System Noise on LIMS Analysis of Igneous Rocks

    SciTech Connect (OSTI)

    Clegg, Samuel M [Los Alamos National Laboratory; Bender, Steven [Los Alamos National Laboratory; Wiens, R. C. [Los Alamos National Laboratory; Carmosino, Marco L [MT. HOLYOKE COLLEGE; Speicher, Elly A [MT. HOLYOKE COLLEGE; Dyar, M. D. [MT. HOLYOKE COLLEGE

    2010-12-23T23:59:59.000Z

    The ChemCam instrument on the Mars Science Laboratory will be the first extraterrestial deployment of laser-induced breakdown spectroscopy (UBS) for remote geochemical analysis. LIBS instruments are also being proposed for future NASA missions. In quantitative LIBS applications using multivariate analysis techniques, it is essential to understand the effects of key instrument parameters and their variability on the elemental predictions. Baseline experiments were run on a laboratory instrument in conditions reproducing ChemCam performance on Mars. These experiments employed Nd:YAG laser producing 17 mJ/pulse on target and an with a 200 {micro}m FWHM spot size on the surface of a sample. The emission is collected by a telescope, imaged on a fiber optic and then interfaced to a demultiplexer capable of >40% transmission into each spectrometer. We report here on an integrated end-to-end system performance model that simulates the effects of output signal degradation that might result from the input signal chain and the impact on multivariate model predictions. There are two approaches to modifying signal to noise (SNR): degrade the signal and/or increase the noise. Ishibashi used a much smaller data set to show that the addition of noise had significant impact while degradation of spectral resolution had much less impact on accuracy and precision. Here, we specifically focus on aspects of remote LIBS instrument performance as they relate to various types of signal degradation. To assess the sensitivity of LIBS analysis to signal-to-noise ratio (SNR) and spectral resolution, the signal in each spectrum from a suite of 50 laboratory spectra of igneous rocks was variably degraded by increasing the peak widths (simulating misalignment) and decreasing the spectral amplitude (simulating decreases in SNR).

  17. How Quantum Computers Fail: Quantum Codes, Correlations in Physical Systems, and Noise Accumulation

    E-Print Network [OSTI]

    Gil Kalai

    2011-06-02T23:59:59.000Z

    The feasibility of computationally superior quantum computers is one of the most exciting and clear-cut scientific questions of our time. The question touches on fundamental issues regarding probability, physics, and computability, as well as on exciting problems in experimental physics, engineering, computer science, and mathematics. We propose three related directions towards a negative answer. The first is a conjecture about physical realizations of quantum codes, the second has to do with correlations in stochastic physical systems, and the third proposes a model for quantum evolutions when noise accumulates. The paper is dedicated to the memory of Itamar Pitowsky.

  18. Wind Turbine Generator System Acoustic Noise Test Report for the Gaia Wind 11-kW Wind Turbine

    SciTech Connect (OSTI)

    Huskey, A.

    2011-11-01T23:59:59.000Z

    This report details the acoustic noise test conducted on the Gaia-Wind 11-kW wind turbine at the National Wind Technology Center. The test turbine is a two- bladed, downwind wind turbine with a rated power of 11 kW. The test turbine was tested in accordance with the International Electrotechnical Commission standard, IEC 61400-11 Ed 2.1 2006-11 Wind Turbine Generator Systems -- Part 11 Acoustic Noise Measurement Techniques.

  19. Analysis of Noise Isolation Methods on Split Power/Ground Plane of Multi-layered Package and PCB for Low Jitter Mixed Mode System

    E-Print Network [OSTI]

    Kim, Yong Jung

    for Low Jitter Mixed Mode System Youchul Jeong, Hyungsoo Kim, Jingook Kim, Jongbae Park, and Joungbo Kim://tera.kaist.ac.kr ABSTRACT - Various noise isolation methods for low jitter on powerlground plane are thoroughly analyzed/ground noise to analog circuit with jitter measurement. II.Analysis of noise isolation methods and experiment

  20. Performance of quantum data transmission systems in the presence of thermal noise

    E-Print Network [OSTI]

    G. Cariolaro; G. Pierobon

    2009-11-16T23:59:59.000Z

    In the literature the performance of quantum data transmission systems is usually evaluated in the absence of thermal noise. A more realistic approach taking into account the thermal noise is intrinsically more difficult because it requires dealing with Glauber coherent states in an infinite--dimensional space. In particular, the exact evaluation of the optimal measurement operators is a very difficult task, and numerical approximation is unavoidable. The paper faces the problem by approximating the P-representation of the noisy quantum states with a large but finite number of terms and applying to them the square root measurement (SRM) approach. Comparisons with the exact solution obtained with convex semidefinite programming show that the SRM approach gives quite accurate results. As application, the performance of quadrature amplitude modulation (QAM) and phase shift keying (PSK) systems is considered. In spite of the fact that the SRM approach is not optimal and overestimates the error probability, also in these cases the quantum detection maintains its superiority with respect to the classical homodyne detection.

  1. System and method for characterizing voiced excitations of speech and acoustic signals, removing acoustic noise from speech, and synthesizing speech

    DOE Patents [OSTI]

    Burnett, Greg C. (Livermore, CA); Holzrichter, John F. (Berkeley, CA); Ng, Lawrence C. (Danville, CA)

    2006-08-08T23:59:59.000Z

    The present invention is a system and method for characterizing human (or animate) speech voiced excitation functions and acoustic signals, for removing unwanted acoustic noise which often occurs when a speaker uses a microphone in common environments, and for synthesizing personalized or modified human (or other animate) speech upon command from a controller. A low power EM sensor is used to detect the motions of windpipe tissues in the glottal region of the human speech system before, during, and after voiced speech is produced by a user. From these tissue motion measurements, a voiced excitation function can be derived. Further, the excitation function provides speech production information to enhance noise removal from human speech and it enables accurate transfer functions of speech to be obtained. Previously stored excitation and transfer functions can be used for synthesizing personalized or modified human speech. Configurations of EM sensor and acoustic microphone systems are described to enhance noise cancellation and to enable multiple articulator measurements.

  2. Low-noise pulsed pre-polarization magnet system for ultra-low field NMR

    SciTech Connect (OSTI)

    Sims, James R [Los Alamos National Laboratory; Schilling, Josef B [Los Alamos National Laboratory; Swenson, Charles A [Los Alamos National Laboratory; Gardner, David L [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Ammerman, Curti N [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    A liquid cooled, pulsed electromagnet of solenoid configuration suitable for duty in an ultra-low field nuclear magnetic resonance system has been designed, fabricated and successfully operated. The magnet design minimizes Johnson noise, minimizes the hydrogen signal and incorporates minimal metal and no ferromagnetic materials. In addition, an acoustically quiet cooling system permitting 50% duty cycle operation was achieved by designing for single-phase, laminar flow, forced convection cooling. Winding, conductor splicing and epoxy impregnation techniques were successfully developed to produce a coil winding body with integral cooling passageways and adequate structural integrity. Issues of material compatibility, housing, coolant flow system and heat rejection system design will be discussed. Additionally, this pulsed electromagnet design has been extended to produce a boiling liquid cooled version in a paired solenoid configuration suitable for duty in an ultra-low field nuclear magnetic resonance system. This pair of liquid nitrogen cooled coils is currently being tested and commissioned. Issues of material compatibility, thermal insulation, thermal contraction, housing and coolant flow design are discussed.

  3. System and method for characterizing voiced excitations of speech and acoustic signals, removing acoustic noise from speech, and synthesizing speech

    DOE Patents [OSTI]

    Burnett, Greg C. (Livermore, CA); Holzrichter, John F. (Berkeley, CA); Ng, Lawrence C. (Danville, CA)

    2002-01-01T23:59:59.000Z

    Low power EM waves are used to detect motions of vocal tract tissues of the human speech system before, during, and after voiced speech. A voiced excitation function is derived. The excitation function provides speech production information to enhance speech characterization and to enable noise removal from human speech.

  4. Response function of turbulence computed via fluctuation-response relation of a Langevin system with vanishing noise

    E-Print Network [OSTI]

    Takeshi Matsumoto; Michio Otsuki; Ooshida Takeshi; Susumu Goto; Akio Nakahara

    2014-06-30T23:59:59.000Z

    For a shell model of the fully developed turbulence and the incompressible Navier-Stokes equations in the Fourier space, when a Gaussian white noise is artificially added to the equation of each mode, an expression of the mean linear response function in terms of the velocity correlation functions is derived by applying the method developed for nonequilibrium Langevin systems [Harada and Sasa, Phys. Rev. Lett. 95, 130602 (2005)]. We verify numerically for the shell model case that the derived expression of the response function, as the noise tends to zero, converges to the response function of the noiseless shell model.

  5. Method and apparatus for providing high bandwidth, low noise mechanical I/O for computer systems

    DOE Patents [OSTI]

    Rosenberg, Louis B. (Pleasanton, CA)

    1998-01-01T23:59:59.000Z

    A method and apparatus for providing high bandwidth and low noise mechanical input and output for computer systems. A gimbal mechanism provides two revolute degrees of freedom to an object about two axes of rotation. A linear axis member is coupled to the gimbal mechanism at the intersection of the two axes of rotation. The linear axis member is capable of being translated along a third axis to provide a third degree of freedom. The user object is coupled to the linear axis member and is thus translatable along the third axis so that the object can be moved along all three degrees of freedom. Transducers associated with the provided degrees of freedom include sensors and actuators and provide an electromechanical interface between the object and a digital processing system. Capstan drive mechanisms transmit forces between the transducers and the object. The linear axis member can also be rotated about its lengthwise axis to provide a fourth degree of freedom, and, optionally, a floating gimbal mechanism is coupled to the linear axis member to provide fifth and sixth degrees of freedom to an object. Transducer sensors are associated with the fourth, fifth, and sixth degrees of freedom. The interface is well suited for simulations of medical procedures and simulations in which an object such as a stylus or a joystick is moved and manipulated by the user.

  6. Performance analysis of multi-antenna OFDM systems with phase noise and imperfect channel estimation

    E-Print Network [OSTI]

    Jalloh, Mohamed

    2009-01-01T23:59:59.000Z

    136 6 Performance Analysis of MISO-OFDM with Phase Noise andMANet MBWA MC MIMO Mbps MMSE MISO MRC MS MSH Media Accessand also exist in SIMO and MISO channels. Multiplexing gain,

  7. Method for removal of random noise in eddy-current testing system

    DOE Patents [OSTI]

    Levy, Arthur J. (Schenectady, NY)

    1995-01-01T23:59:59.000Z

    Eddy-current response voltages, generated during inspection of metallic structures for anomalies, are often replete with noise. Therefore, analysis of the inspection data and results is difficult or near impossible, resulting in inconsistent or unreliable evaluation of the structure. This invention processes the eddy-current response voltage, removing the effect of random noise, to allow proper identification of anomalies within and associated with the structure.

  8. Noise-compensating pulses for electrostatically controlled silicon spin qubits

    E-Print Network [OSTI]

    Xin Wang; Fernando A. Calderon-Vargas; Muhed S. Rana; Jason P. Kestner; Edwin Barnes; Sankar Das Sarma

    2014-10-21T23:59:59.000Z

    We study the performance of SUPCODE---a family of dynamically correcting pulses designed to cancel simultaneously both Overhauser and charge noise for singlet-triplet spin qubits---adapted to silicon devices with electrostatic control. We consider both natural Si and isotope-enriched Si systems, and in each case we investigate the behavior of individual gates under static noise and perform randomized benchmarking to obtain the average gate error under realistic 1/f noise. We find that in most cases SUPCODE pulses offer roughly an order of magnitude reduction in gate error, and especially in the case of isotope-enriched Si, SUPCODE yields gate operations of very high fidelity. We also develop a version of SUPCODE that cancels the charge noise only, "$\\delta J$-SUPCODE", which is particularly beneficial for isotope-enriched Si devices where charge noise dominates Overhauser noise, offering a level of error reduction comparable to the original SUPCODE while yielding gate times that are 30% to 50% shorter. Our results show that the SUPCODE noise-compensating pulses provide a fast, simple, and effective approach to error suppression, bringing gate errors well below the quantum error correction threshold in principle.

  9. Experimental results of water film formation on various fuel forms from a fire suppression system

    SciTech Connect (OSTI)

    Ross, R.H.; Davis, J.R.

    1993-12-31T23:59:59.000Z

    The purpose of the study was to determine the thickness and coverage of water film formations on various materials during fire sprinkler deluge. An exhaustive literature search revealed that no applicable research data exists that governs water film formations from fire protection systems. Therefore, a controlled, infield, mockup was created to predict the thickness and coverage of water film on fissile material forms. This paper discusses the background, experimental procedure and the characterization of these water films.

  10. Improvement of extraction system geometry with suppression of possible Penning discharge ignition

    SciTech Connect (OSTI)

    Delferrière, O., E-mail: olivier.delferriere@cea.fr; Gobin, R.; Harrault, F.; Nyckees, S.; Tuske, O. [Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191-Gif/Yvette (France)] [Commissariat à l’Energie Atomique et aux Energies Alternatives, CEA/Saclay, DSM/IRFU, 91191-Gif/Yvette (France)

    2014-02-15T23:59:59.000Z

    During the past two years, a new ECR 2.45 GHz type ion source has been developed especially dedicated to intense light ion injector project like IPHI (Injecteur Proton Haute Intensité), IFMIF (International Fusion Materials Irradiation Facility), to reduce beam emittance at RFQ entrance by shortening the length of the LEBT. This new ALISES concept (Advanced Light Ion Source Extraction System) is based on the use of an additional LEBT short length solenoid very close to the extraction aperture. The fringe field of this new solenoid produces the needed magnetic field to create the ECR resonance in the plasma chamber. Such geometry allows first putting the solenoid at ground potential, while saving space in front of the extraction to move the first LEBT solenoid closer and focus earlier the intense extracted beam. During the commissioning of the source in 2011–2012, ALISES has produced about 20 mA extracted from a 6 mm diameter plasma extraction hole at 23 kV. But the magnetic configuration combined to the new extraction system geometry led to important Penning discharge conditions in the accelerator column. Lots of them have been eliminated by inserting glass pieces between electrodes to modify equipotential lines with unfavorable ExB vacuum zones where particles were produced and trapped. To study Penning discharge location, several 3D calculations have been performed with OPERA-3D/TOSCA code to simulate the possible production and trapping of electrons in the extraction system. The results obtained on different sources already built have shown very good agreement with sparks location observed experimentally on electrodes. The simulations results as well as experimental measurements are presented and solutions to prevent possible Penning discharge in future source geometries are established.

  11. Wind Turbine Generator System Acoustic Noise Test Report for the ARE 442 Wind Turbine

    SciTech Connect (OSTI)

    Huskey, A.; van Dam, J.

    2010-11-01T23:59:59.000Z

    This test was conducted on the ARE 442 as part of the U.S. Department of Energy's (DOE's) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of this project. Acoustic noise testing is one of up to five tests that may be performed on the turbines, including duration, safety and function, power performance, and power quality tests. The acoustic noise test was conducted to the IEC 61400-11 Edition 2.1.

  12. Experimental noise filtering by quantum control

    E-Print Network [OSTI]

    A. Soare; H. Ball; D. Hayes; J. Sastrawan; M. C. Jarratt; J. J. McLoughlin; X. Zhen; T. J. Green; M. J. Biercuk

    2014-07-05T23:59:59.000Z

    Instabilities due to extrinsic interference are routinely faced in systems engineering, and a common solution is to rely on a broad class of $\\textit{filtering}$ techniques in order to afford stability to intrinsically unstable systems. For instance, electronic systems are frequently designed to incorporate electrical filters composed of, $\\textit{e.g.}$ RLC components, in order to suppress the effects of out-of-band fluctuations that interfere with desired performance. Quantum coherent systems are now moving to a level of complexity where challenges associated with realistic time-dependent noise are coming to the fore. Unfortunately, standard control solutions involving feedback are generally impossible due to the strictures of quantum mechanics, and existing error-suppressing gate constructions generally rely on unphysical bang-bang controls or quasi-static error models that do not reflect realistic laboratory environments. In this work we use the theory of quantum control engineering and experiments with trapped $^{171}$Yb$^{+}$ ions to demonstrate the construction of novel $\\textit{noise filters}$ which are specifically designed to mitigate the effect of realistic time-dependent fluctuations on qubits \\emph{during useful operations}. Starting with desired filter characteristics and the Walsh basis functions, we use a combination of analytic design rules and numeric search to construct time-domain noise filters tailored to a desired state transformation. Our results validate the generalized filter-transfer function framework for arbitrary quantum control operations, and demonstrate that it can be leveraged as an effective and efficient tool for developing novel robust control protocols.

  13. Eect of noise on the tuning properties of excitable systems Andre Longtin *

    E-Print Network [OSTI]

    Longtin, André

    between dierent phase-locked be- haviors as parameters are varied [4]. If instead the cell is excitable by ongoing research into the mechanisms underlying aperiodic phase-locked ®ring in many excitable neurons of additive dynamical noise on simple phase-locking patterns in the Fitzhugh±Nagumo (FHN) two-dimen- sional

  14. Quantum Model Of Spin Noise

    E-Print Network [OSTI]

    R. Annabestani; D. G. Cory; J. Emerson

    2015-03-03T23:59:59.000Z

    Any ensemble of quantum particles exhibits statistical fluctuations known as spin noise. Here, we provide a description of spin noise in the language of open quantum systems. The description unifies the signatures of spin noise under both strong and weak measurements. Further, the model accounts for arbitrary spin dynamics from an arbitrary initial state. In all cases we can find both the spin noise and its time correlation function.

  15. An evaluation of neural networks for identification of system parameters in reactor noise signals

    SciTech Connect (OSTI)

    Miller, L.F.

    1991-12-31T23:59:59.000Z

    Several backpropagation neural networks for identifying fundamental mode eigenvalues were evaluated. The networks were trained and tested on analytical data and on results from other numerical methods. They were then used to predict first mode break frequencies for noise data from several sources. These predictions were, in turn, compared with analytical values and with results from alternative methods. Comparisons of results for some data sets suggest that the accuracy of predictions from neural networks are essentially equivalent to results from conventional methods while other evaluations indicate that either method may be superior. Experience gained from these numerical experiments provide insight for improving the performance of neural networks relative to other methods for identifying parameters associated with experimental data. Neural networks may also be used in support of conventional algorithms by providing starting points for nonlinear minimization algorithms.

  16. An evaluation of neural networks for identification of system parameters in reactor noise signals

    SciTech Connect (OSTI)

    Miller, L.F.

    1991-01-01T23:59:59.000Z

    Several backpropagation neural networks for identifying fundamental mode eigenvalues were evaluated. The networks were trained and tested on analytical data and on results from other numerical methods. They were then used to predict first mode break frequencies for noise data from several sources. These predictions were, in turn, compared with analytical values and with results from alternative methods. Comparisons of results for some data sets suggest that the accuracy of predictions from neural networks are essentially equivalent to results from conventional methods while other evaluations indicate that either method may be superior. Experience gained from these numerical experiments provide insight for improving the performance of neural networks relative to other methods for identifying parameters associated with experimental data. Neural networks may also be used in support of conventional algorithms by providing starting points for nonlinear minimization algorithms.

  17. Noise-induced cooperative dynamics and its control in coupled neuron models

    E-Print Network [OSTI]

    B. Hauschildt; N. B. Janson; A. Balanov; E. Schoell

    2006-10-04T23:59:59.000Z

    We investigate feedback control of the cooperative dynamics of two coupled neural oscillators that is induced merely by external noise. The interacting neurons are modelled as FitzHugh-Nagumo systems with parameter values at which no autonomous oscillations occur, and each unit is forced by its own source of random fluctuations. Application of delayed feedback to only one of two subsystems is shown to be able to change coherence and timescales of noise induced oscillations either in the given subsystem, or globally. It is also able to induce or to suppress stochastic synchronization under certain conditions.

  18. Phase Noise in MIMO Systems: Bayesian Cramer-Rao Bounds and Soft-Input Estimation

    E-Print Network [OSTI]

    Nasir, Ali A; Mehrpouyan, Hani; Schober, Robert; Hua, Yingbo

    2013-01-01T23:59:59.000Z

    for a 4 4 MIMO system, the proposed soft-input EKF-EKSin MIMO Systems: Bayesian Cramér–Rao Bounds and Soft-Inputof a MIMO system employing the proposed soft-input EKF-EKS

  19. Methods for Estimation and Control of Linear Systems Driven by Cauchy Noises

    E-Print Network [OSTI]

    Fernandez, Javier Huerta

    2013-01-01T23:59:59.000Z

    prediction optimal control for a scalar linear system withPrediction Optimal Control for a Scalar Linear System withsystems in modern stochastic optimal control, algorithms like the linear

  20. Detection and location of mechanical system degradation by using detector signal noise data

    SciTech Connect (OSTI)

    Damiano, B.; Blakeman, E.D.; Phillips, L.D.

    1994-06-01T23:59:59.000Z

    This report describes the investigation of a diagnostic method for detecting and locating the source of structural degradation in mechanical systems. The goal of this investigation was to determine whether the diagnostic method would be practically and successfully applied to detect and locate structural changes in a mechanical system. The diagnostic method uses a mathematical model of the mechanical system to define relationships between system parameters, such as spring rates and damping rates, and measurable spectral features, such as natural frequencies and mode shapes. These model-defined relationships are incorporated into a neural network, which is used to relate measured spectral features to system parameters. The diagnosis of the system`s condition is performed by presenting the neural network with measured spectral features and comparing the system parameters estimated by the neural network to previously estimated values. Changes in the estimated system parameters indicate the location and severity of degradation in the mechanical system. The investigation involved applying the method by using computer-simulated data and data collected from a bench-top mechanical system. The effects of neural network training set size and composition on the accuracy of the model parameter estimates were investigated by using computer-simulated data. The measured data were used to demonstrate that the method can be applied to estimate the parameters of a {open_quotes}real{close_quotes} mechanical system. The results show that this diagnostic method can be applied to successfully locate and estimate the magnitude of structural changes in a mechanical system. The average error in the estimated spring rate values of the bench-top mechanical system was approximately 5 to 10%. This degree of accuracy is sufficient to permit the use of this method for detecting and locating structural degradation in mechanical systems.

  1. Noise propagation in hybrid models of nonlinear systems: The Ginzburg–Landau equation

    SciTech Connect (OSTI)

    Taverniers, Søren [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Alexander, Francis J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tartakovsky, Daniel M. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States)

    2014-04-01T23:59:59.000Z

    Every physical phenomenon can be described by multiple models with varying degrees of fidelity. The computational cost of higher fidelity models (e.g., molecular dynamics simulations) is invariably higher than that of their lower fidelity counterparts (e.g., a continuum model based on differential equations). While the former might not be suitable for large-scale simulations, the latter are not universally valid. Hybrid algorithms provide a compromise between the computational efficiency of a coarse-scale model and the representational accuracy of a fine-scale description. This is achieved by conducting a fine-scale computation in subdomains where it is absolutely required (e.g., due to a local breakdown of a continuum model) and coupling it with a coarse-scale computation in the rest of a computational domain. We analyze the effects of random fluctuations generated by the fine-scale component of a nonlinear hybrid on the hybrid's overall accuracy and stability. Two variants of the time-dependent Ginzburg–Landau equation (GLE) and their discrete representations provided by a nearest-neighbor Ising model serve as a computational testbed. Our analysis shows that coupling these descriptions in a one-dimensional simulation leads to erroneous results. Adding a random source term to the GLE provides accurate prediction of the mean behavior of the quantity of interest (magnetization). It also allows the two GLE variants to correctly capture the strength of the microscale fluctuations. Our work demonstrates the importance of fine-scale noise in hybrid simulations, and suggests the need for replacing an otherwise deterministic coarse-scale component of the hybrid with its stochastic counterpart.

  2. A noise-gated PLL for clock recovery in a free-space laser communication system

    E-Print Network [OSTI]

    Lund, Gavin

    2012-01-01T23:59:59.000Z

    In this thesis, I developed a phase-locked loop system for data clock recovery in a free-space laser communication application. The clock recovery unit is designed to operate at extremely low optical received power, tolerate ...

  3. In this paper, a system is described for the recognition of mixtures of noise sources in acoustic input signals. The

    E-Print Network [OSTI]

    Virtanen, Tuomas

    acoustic surveillance, speech processing in a noisy background, acoustic database queries, noise pollution in acoustic input signals. The problem is approached by utilizing both bottom­up signal analysis and top. 1 INTRODUCTION Recognition of acoustic noise mixtures is viewed here as the detection and broad

  4. active noise control: Topics by E-print Network

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

    significant noise ... Hong, Seung Hyuck 2009-01-01 2 Design of an Active Noise Control System using Plasma Actuators Engineering Websites Summary: and analysed from sensors located...

  5. An ultra low-noise AC beam transformer and digital signal processing system for CERN's ELENA ring

    E-Print Network [OSTI]

    Angoletta, M E; Caspers, F; Federmann, S; Molendijk, J; Pedersen, F; Sanchez-Quesada, J

    2013-01-01T23:59:59.000Z

    CERN’s Extra Low ENergy Antiproton (ELENA) ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator (AD). Essential longitudinal diagnostics required for commissioning and operation include the intensity measurement for bunched and debunched beams and the measurement of p/p for debunched beams to assess the electron cooling performance. The beam phase information is also needed by the Low-Level RF (LLRF) system. The baseline system for providing the required beam parameters and signals is based upon two ultra-low-noise AC beam transformers and associated digital signal processing. The AC beam transformers cover different frequency regions and are an adaptation to the ELENA layout of those used in the AD. Two AC beam transformers will also be installed in the extraction lines to provide beam intensity measurements. The digital signal processing will be carried out with the leadingedge hardware family used for ELENA’s L...

  6. Control Engineering Practice 12 (2004) 987988 Emerging technologies for active noise and vibration control systems

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    for a Cartesian robotic arm. The system is modeled as a cantilever beam with a trans- lation base support the enclosure. A reduced order model of the structure is then used to design a controller for broadband of a controller on a laboratory setup designed for this specific purpose. Kermani, Moallem and Patel propose

  7. Quantum noise in photothermal cooling

    SciTech Connect (OSTI)

    De Liberato, Simone [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Lambert, Neill [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Nori, Franco [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2011-03-15T23:59:59.000Z

    We study the problem of cooling a mechanical oscillator using the photothermal (bolometric) force. Contrary to previous attempts to model this system, we take into account the noise effects due to the granular nature of photon absorption. We achieve this by developing a Langevin formalism for the motion of the cantilever, valid in the bad-cavity limit, which includes both photon absorption shot noise and the noise due to radiation pressure. This allows us to tackle the cooling problem down to the noise-dominated regime and to find reasonable estimates for the lowest achievable phonon occupation in the cantilever.

  8. On the optimal feedback control of linear quantum systems in the presence of thermal noise

    E-Print Network [OSTI]

    Marco G. Genoni; Stefano Mancini; Alessio Serafini

    2013-04-27T23:59:59.000Z

    We study the possibility of taking bosonic systems subject to quadratic Hamiltonians and a noisy thermal environment to non-classical stationary states by feedback loops based on weak measurements and conditioned linear driving. We derive general analytical upper bounds for the single mode squeezing and multimode entanglement at steady state, depending only on the Hamiltonian parameters and on the number of thermal excitations of the bath. Our findings show that, rather surprisingly, larger number of thermal excitations in the bath allow for larger steady-state squeezing and entanglement if the efficiency of the optimal continuous measurements conditioning the feedback loop is high enough. We also consider the performance of feedback strategies based on homodyne detection and show that, at variance with the optimal measurements, it degrades with increasing temperature.

  9. Ventilation and Suppression Systems in Road Tunnels: Some Issues regarding their Appropriate Use in a Fire Emergency 

    E-Print Network [OSTI]

    Carvel, Ricky O; Rein, Guillermo; Torero, Jose L

    Two important tunnel safety technologies are addressed. The majority of long road tunnels have ventilation systems. In the event of a fire in a tunnel, such systems will influence fire development in a number of different ...

  10. Benchmark enclosure fire suppression experiments - phase 1 test report.

    SciTech Connect (OSTI)

    Figueroa, Victor G.; Nichols, Robert Thomas; Blanchat, Thomas K.

    2007-06-01T23:59:59.000Z

    A series of fire benchmark water suppression tests were performed that may provide guidance for dispersal systems for the protection of high value assets. The test results provide boundary and temporal data necessary for water spray suppression model development and validation. A review of fire suppression in presented for both gaseous suppression and water mist fire suppression. The experimental setup and procedure for gathering water suppression performance data are shown. Characteristics of the nozzles used in the testing are presented. Results of the experiments are discussed.

  11. Suppression of pool fires with HRC-125 in a simulated engine nacelle.

    SciTech Connect (OSTI)

    Keyser, David R. (INS, Inc., Lexington Park, MD); Hewson, John C.

    2007-06-01T23:59:59.000Z

    CFD simulations are conducted to predict the distribution of fire suppressant in an engine nacelle and to predict the suppression of pool fires by the application of this suppressant. In the baseline configuration, which is based on an installed system, suppressant is injected through four nozzles at a rate fast enough to suppress all simulated pool fires. Variations that reduce the mass of the suppression system (reducing the impact of the suppression system on meeting mission needs) are considered, including a reduction in the rate of suppressant injection, a reduction in the mass of suppressant and a reduction in the number of nozzles. In general, these variations should work to reduce the effectiveness of the suppression system, but the CFD results point out certain changes that have negligible impact, at least for the range of phenomena considered here. The results are compared with measurements where available. Comparisons with suppressant measurements are reasonable. A series of twenty-three fire suppression tests were conducted to check the predictions. The pre-test predictions were generally successful in identifying the range of successful suppression tests. In two separate cases, each where one nozzle of the suppression system was capped, the simulation results did indicate a failure to suppress for a condition where the tests indicated successful suppression. When the test-suppressant discharge rate was reduced by roughly 25%, the tests were in agreement with the predictions. That is, the simulations predict a failure to suppress slightly before observed in these cases.

  12. Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

    DOE Patents [OSTI]

    West, Phillip B.; Haefner, Daryl

    2004-08-17T23:59:59.000Z

    Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

  13. Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

    DOE Patents [OSTI]

    West, Phillip B.; Haefner, Daryl

    2005-12-13T23:59:59.000Z

    Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

  14. Optimal control of quantum gates and suppression of decoherence in a system of interacting two-level particles

    E-Print Network [OSTI]

    Matthew Grace; Constantin Brif; Herschel Rabitz; Ian A. Walmsley; Robert L. Kosut; Daniel A. Lidar

    2007-04-16T23:59:59.000Z

    Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental effect of decoherence. One set of particles functions as the quantum information processor, whose evolution is controlled by a time-dependent external field. The other particles are not directly controlled and serve as an effective environment, coupling to which is the source of decoherence. The control objective is to generate target one- and two-qubit unitary gates in the presence of strong environmentally-induced decoherence and under physically motivated restrictions on the control field. The quantum-gate fidelity, expressed in terms of a novel state-independent distance measure, is maximized with respect to the control field using combined genetic and gradient algorithms. The resulting high-fidelity gates demonstrate the feasibility of precisely guiding the quantum evolution via optimal control, even when the system complexity is exacerbated by environmental coupling. It is found that the gate duration has an important effect on the control mechanism and resulting fidelity. An analysis of the sensitivity of the gate performance to random variations in the system parameters reveals a significant degree of robustness attained by the optimal control solutions.

  15. Effects of noise exposure on click detection and the temporal resolution ability of the goldfish auditory system

    E-Print Network [OSTI]

    Ladich, Friedrich

    , Althanstrasse 14, A-1090 Vienna, Austria Received 30 March 2004; accepted 19 August 2004 Available online 26 to growing anthropogenic activities such as shipping, drilling, seismic exploration or energy pro- duction (hydroelectric or offshore wind power plants), noise is an ever-increasing environmental factor in the aquatic

  16. Noise Pollution Control (Minnesota)

    Broader source: Energy.gov [DOE]

    These regulations set noise standards and direct municipalities to take reasonable measures to prevent the establishment of land use activities with a high noise pollution potential.

  17. Water Mist Suppression in Conjunction with Displacement

    E-Print Network [OSTI]

    Hickman, Mark

    Water Mist Suppression in Conjunction with Displacement Ventilation By Benjamin Piers Hume-2758 #12;#12;Displacement Water Mist System Masters of Fire Engineering Thesis 2003 i A man of genius makes Water Mist System Masters of Fire Engineering Thesis 2003 ii #12;Displacement Water Mist System Masters

  18. Noise Macromodel for Radio Frequency Integrated Circuits Noise performance is a critical analog and RF

    E-Print Network [OSTI]

    Li, Xin

    translation. Moreover, low Noise Amplifiers (LNA) are usually treated as LTI systems, but when the design process. In this paper we propose a noise macromodel for analog circuits and demonstrate it by way designers for back-of-the-envelope calculations, it only specifies noise performance at a given frequency

  19. Optical Shelving: Suppressed Fluorescence

    E-Print Network [OSTI]

    Mould, R A

    2007-01-01T23:59:59.000Z

    The shelving phenomenon of quantum optics, originally observed by Dehmelt, is analyzed in terms of the nRules that are given in another paper. The heuristic value of these rules is apparent because they reveal the mechanism that enforces the suppression of fluorescence during the dark period associated with shelving.

  20. Optical Shelving: Suppressed Fluorescence

    E-Print Network [OSTI]

    Richard A Mould

    2011-04-11T23:59:59.000Z

    The shelving phenomenon of quantum optics, originally observed by Dehmelt, is analyzed in terms of the qRules that are given in another paper. The heuristic value of these rules is apparent because they not only describe the dark period during shelving, but they reveal the mechanism that enforces the suppression of fluorescence during that time.

  1. System and method of reducing motion-induced noise in the optical detection of an ultrasound signal in a moving body of material

    DOE Patents [OSTI]

    Habeger, Jr., Charles C. (Smyrna, GA); LaFond, Emmanuel F. (Atlanta, GA); Brodeur, Pierre (Smyrna, GA); Gerhardstein, Joseph P. (Decatur, GA)

    2002-01-01T23:59:59.000Z

    The present invention provides a system and method to reduce motion-induced noise in the detection of ultrasonic signals in a moving sheet or body of material. An ultrasonic signal is generated in a sheet of material and a detection laser beam is moved along the surface of the material. By moving the detection laser in the same direction as the direction of movement of the sheet of material the amount of noise induced in the detection of the ultrasonic signal is reduced. The scanner is moved at approximately the same speed as the moving material. The system and method may be used for many applications, such in a paper making process or steel making process. The detection laser may be directed by a scanner. The movement of the scanner is synchronized with the anticipated arrival of the ultrasonic signal under the scanner. A photodetector may be used to determine when a ultrasonic pulse has been directed to the moving sheet of material so that the scanner may be synchronized the anticipated arrival of the ultrasonic signal.

  2. Acoustical and Noise Control Criteria and Guidelines for Building Design and Operations

    E-Print Network [OSTI]

    Evans, J. B.; Himmel, C. N.

    Noise, vibration and acoustical design, construction, commissioning and operation practices influence building cost, efficiency, performance and effectiveness. Parameters for structural vibration, building systems noise, acoustics and environmental...

  3. Nuclear spin noise in NMR revisited

    E-Print Network [OSTI]

    Ferrand, Guillaume; Luong, Michel; Desvaux, Hervé

    2015-01-01T23:59:59.000Z

    The theoretical shapes of nuclear spin-noise spectra in NMR are derived by considering a receiver circuit with finite, preamplifier input impedance and a transmission line between the preamplifier and the probe. Using this model, it becomes possible to reproduce all observed experimental features: variation of the NMR resonance linewidth as a function of the transmission line phase, nuclear spin-noise signals appearing as a "bump" or as a "dip" superimposed on the average electronic noise level even for a spin system and probe at the same temperature, pure in-phase Lorentzian spin-noise signals exhibiting non-vanishing frequency shifts. Extensive comparison to experimental measurements validate the model predictions, and define the conditions for obtaining pure in-phase Lorentzian-shape nuclear spin noise with a vanishing frequency shift, in other words, the conditions for simultaneously obtaining the Spin-Noise and Frequency-Shift Tuning Optima.

  4. Intelligibility enhancement of synthetic speech in noise

    E-Print Network [OSTI]

    Edinburgh, University of

    Intelligibility enhancement of synthetic speech in noise C´assia Valentini Botinh~ao TH E U N I V E of a hidden Markov model (HMM-) based speech synthesis system that allows for flexible enhancement strategies with noise-independent enhancement approaches based on the acoustics of highly intelligible speech

  5. Citizen Noise Pollution Monitoring Maisonneuve

    E-Print Network [OSTI]

    TAGora project

    [Information Systems Applications]: Miscellaneous General Terms Management, Measurement, Human Factors-localisation, tagging, mobile phones. 1. INTRODUCTION Noise pollution is a major problem in urban environments problems such as air and water pollution. With this background, there is a clear need to manage

  6. Interplay of friction and noise and enhancement of disoriented chiral condensate

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2000-11-01T23:59:59.000Z

    Using the Langevin equation for the linear $\\sigma$ model, we have investigated the effect of friction and noise on the possible disoriented chiral condensate formation. Friction and noise are supposed to suppress longwavelength oscillations and growth of disoriented chiral condensate domains. Details simulation shows that for heavy ion collisions, interplay of friction and noise occur in such a manner that formation of disoriented chiral condensate domains are enhanced.

  7. Influence of physical parameters and operating conditions for structural integrity of mechanical system subjected to squeal noise

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for the static load and circular wave front lines for the ramp loading. Introduction Disc brake systems-linear vibrations, acoustic radiation, brake squeal, friction Abstract. This work proposes to study the effects of physical parameters and loading conditions on both dynamic and acoustic responses of a brake system

  8. High Precision Noise Measurements at Microwave Frequencies

    SciTech Connect (OSTI)

    Ivanov, Eugene; Tobar, Michael [School of Physics, University of Western Australia, 35 Stirling Hwy., Crawley, 6009, WA (Australia)

    2009-04-23T23:59:59.000Z

    We describe microwave noise measurement system capable of detecting the phase fluctuations of rms amplitude of 2{center_dot}10{sup -11} rad/{radical}(Hz). Such resolution allows the study of intrinsic fluctuations in various microwave components and materials, as well as precise tests of fundamental physics. Employing this system we discovered a previously unknown phenomenon of down-conversion of pump oscillator phase noise into the low-frequency voltage fluctuations.

  9. Multi-band OFDM UWB receiver with narrowband interference suppression 

    E-Print Network [OSTI]

    Kelleci, Burak

    2009-05-15T23:59:59.000Z

    A multi band orthogonal frequency division multiplexing (MB-OFDM) compatible ultra wideband (UWB) receiver with narrowband interference (NBI) suppression capability is presented. The average transmit power of UWB system ...

  10. Selection of hydrate suppression methods for gas streams

    SciTech Connect (OSTI)

    Behrens, S.D.; Covington, K.K.; Collie, J.T. III

    1999-07-01T23:59:59.000Z

    This paper will discuss and compare the methods used to suppress hydrate formation in natural gas streams. Included in the comparison will be regenerated systems using ethylene glycol and non-regenerated systems using methanol. A comparison will be made between the quantities of methanol and ethylene glycol required to achieve a given a suppression. A discussion of BTEX emissions resulting from the ethylene glycol regenerator along with the effect or process variables on these emissions is also given.

  11. A sub nrad beam pointing monitoring and stabilization system for controlling input beam jitter in GW interferometers

    E-Print Network [OSTI]

    Canuel, Benjamin; Mantovani, Maddalena; Marque, Julien; Ruggi, Paolo; Tacca, Matteo

    2014-01-01T23:59:59.000Z

    In this paper a simple and very effective control system to monitor and suppress the beam jitter noise at the input of an optical system, called Beam Pointing Control (BPC) system, will be described showing the theoretical principle and an experimental demonstration for the application of large scale gravitational wave interferometers, in particular for the Advanced Virgo detector. For this purpose the requirements for the control accuracy and the sensing noise will be computed by taking into account the Advanced Virgo optical configuration and the outcomes will be compared with the experimental measurement obtained in the laboratory. The system has shown unprecedented performance in terms of control accuracy and sensing noise. The BPC system has achieved a control accuracy of ~ $10^{-8}$ rad for the tilt and ~ $10^{-7}$ m for the shift and a sensing noise of less than 1 nrad/$\\sqrt{Hz}$ resulting compliant with the Advance Virgo gravitational wave interferometer requirements.

  12. aerodynamic noise: Topics by E-print Network

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

    various vane Papamoschou, Dimitri 8 Aerodynamic investigations of noise-reducing high-lift systems for passenger transport aircraft. Open Access Theses and Dissertations Summary:...

  13. Influence of monolayer contamination on electric-field-noise heating in ion traps

    E-Print Network [OSTI]

    A. Safavi-Naini; E. Kim; P. F. Weck; P. Rabl; H. R. Sadeghpour

    2012-09-28T23:59:59.000Z

    Electric field noise is a hinderance to the assembly of large scale quantum computers based on entangled trapped ions. Apart from ubiquitous technical noise sources, experimental studies of trapped ion heating have revealed additional limiting contributions to this noise, originating from atomic processes on the electrode surfaces. In a recent work [A. Safavi-Naini et al., Phys. Rev. A 84, 023412 (2011)] we described a microscopic model for this excess electric field noise, which points a way towards a more systematic understanding of surface adsorbates as progenitors of electric field jitter noise. Here, we address the impact of surface monolayer contamination on adsorbate induced noise processes. By using exact numerical calculations for H and N atomic monolayers on an Au(111) surface representing opposite extremes of physisorption and chemisorption, we show that an additional monolayer can significantly affect the noise power spectrum and either enhance or suppress the resulting heating rates.

  14. Graphene-based terahertz photodetector by noise thermometry technique

    SciTech Connect (OSTI)

    Wang, Ming-Jye, E-mail: mingjye@asiss.sinica.edu.tw [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Wang, Ji-Wun [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan (China); Wang, Chun-Lun; Chiang, Yen-Yu; Chang, Hsian-Hong [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China)

    2014-01-20T23:59:59.000Z

    We report the characteristics of graphene-based terahertz (THz) photodetector based on noise thermometry technique by measuring its noise power at frequency from 4 to 6 GHz. Hot electron system in graphene microbridge is generated after THz photon pumping and creates extra noise power. The equivalent noise temperature and electron temperature increase rapidly in low THz pumping regime and saturate gradually in high THz power regime which is attributed to a faster energy relaxation process involved by stronger electron-phonon interaction. Based on this detector, a conversion efficiency around 0.15 from THz power to noise power in 4–6?GHz span has been achieved.

  15. Mechanical impedance and CPX noise of SMA V.F. Vazquez and S.E. Paje

    E-Print Network [OSTI]

    Boyer, Edmond

    to the volume population affected, are transportation systems like motor vehicles. Tire road noise is the noiseMechanical impedance and CPX noise of SMA pavements V.F. V´azquez and S.E. Paje UCLM-LA2IC, Av 2012 Nantes Conference 23-27 April 2012, Nantes, France 167 #12;CPX noise is the sound measured

  16. A formula for charmonium suppression

    SciTech Connect (OSTI)

    Pena, C., E-mail: pena@ift.uni.wroc.pl; Blaschke, D., E-mail: blaschke@ift.uni.wroc.pl [University of Wroclaw, Institute for Theoretical Physics (Poland)

    2012-07-15T23:59:59.000Z

    In this work a formula for charmonium suppression obtained by Matsui in 1989 is analytically generalized for the case of complex cc-barpotential described by a 3-dimensional and isotropic time-dependent harmonic oscillator (THO). It is suggested that under certain scheme the formula can be applied to describe J/{psi} suppression in heavy-ion collisions at CERN-SPS, RHIC, and LHC with the advantage of analytical tractability.

  17. Measurement Noise versus Process Noise in Ionosphere Estimation for WAAS

    E-Print Network [OSTI]

    Stanford University

    Measurement Noise versus Process Noise in Ionosphere Estimation for WAAS Juan Blanch, Todd Walter of several parameters: the geometry of the measurements, the measurement noise, and the state of the ionosphere, which yields the process noise. It is very important to distinguish carefully between measurement

  18. Newtonian-noise cancellation in full-tensor gravitational-wave detectors

    E-Print Network [OSTI]

    Jan Harms; Ho Jung Paik

    2015-04-18T23:59:59.000Z

    Terrestrial gravity noise, also known as Newtonian noise, produced by ambient seismic and infrasound fields will pose one of the main sensitivity limitations in low-frequency, ground-based, gravitational-wave (GW) detectors. It was estimated that this noise foreground needs to be suppressed by about 3 -- 5 orders of magnitude in the frequency band 10\\,mHz to 1\\,Hz, which will be extremely challenging. In this article, we present a new approach that greatly facilitates cancellation of gravity noise in full-tensor GW detectors. The method uses optimal combinations of tensor channels and environmental sensors such as seismometers and microphones to reduce gravity noise. It makes explicit use of the direction of propagation of a GW, and can therefore either be implemented in directional searches for GWs or in observations of known sources. We show that suppression of the Newtonian-noise foreground is greatly facilitated using the extra strain channels in full-tensor GW detectors. Only a modest number of auxiliary, high-sensitivity environmental sensors are required to achieve noise suppression by a few orders of magnitude.

  19. Entangled quantum probes for dynamical environmental noise

    E-Print Network [OSTI]

    Matteo A. C. Rossi; Matteo G. A. Paris

    2015-03-11T23:59:59.000Z

    We address the use of entangled qubits as quantum probes to characterize the dynamical noise induced by complex environments. In particular, we show that entangled probes improve estimation of the correlation time for a broad class of environmental noises compared to any sequential strategy involving single qubit preparation. The effect is present when the noise is faster than a threshold value, a regime which may always be achieved by tuning the coupling between the quantum probe and the environment inducing the noise. Our scheme exploits time-dependent sensitivity of quantum systems to decoherence and does not require dynamical control on the probes. We derive the optimal interaction time and the optimal probe preparation, showing that it corresponds to multiqubit GHZ states when entanglement is useful. We also show robustness of the scheme against depolarization or dephasing of the probe, and discuss simple measurements approaching optimal precision.

  20. Characterization of control noise effects in optimal quantum unitary dynamics

    E-Print Network [OSTI]

    David Hocker; Constantin Brif; Matthew D. Grace; Ashley Donovan; Tak-San Ho; Katharine Moore Tibbetts; Rebing Wu; Herschel Rabitz

    2014-11-13T23:59:59.000Z

    This work develops measures for quantifying the effects of field noise upon targeted unitary transformations. Robustness to noise is assessed in the framework of the quantum control landscape, which is the mapping from the control to the unitary transformation performance measure (quantum gate fidelity). Within that framework, a new geometric interpretation of stochastic noise effects naturally arises, where more robust optimal controls are associated with regions of small overlap between landscape curvature and the noise correlation function. Numerical simulations of this overlap in the context of quantum information processing reveal distinct noise spectral regimes that better support robust control solutions. This perspective shows the dual importance of both noise statistics and the control form for robustness, thereby opening up new avenues of investigation on how to mitigate noise effects in quantum systems.

  1. Title: A brief history of the Rolls-Royce University Technology Centre in Gas Turbine Noise at the Institute of Sound and Vibration Research

    E-Print Network [OSTI]

    Sóbester, András

    to generation and propagation of noise from gas turbine engines. Aircraft noise is a critical technical issueReport Title: A brief history of the Rolls-Royce University Technology Centre in Gas Turbine Noise and systems engineering, gas turbine transmission systems and gas turbine noise. The UTC in gas turbine noise

  2. Estimation and Detection in the Presence of Ringing Noise

    E-Print Network [OSTI]

    Manduchi, Roberto

    , such as those encountered in low frequency applications, the ringing noise consists of some distorted versionEstimation and Detection in the Presence of Ringing Noise Brant Jameson Department of Computer-- To minimize size and cost, most air coupled ultra- sound range systems are designed as mono-static systems

  3. Non-equilibrium Entanglement and Noise in Coupled Qubits

    E-Print Network [OSTI]

    N. Lambert; R. Aguado; T. Brandes

    2006-02-03T23:59:59.000Z

    We study charge entanglement in two Coulomb-coupled double quantum dots in thermal equilibrium and under stationary non-equilibrium transport conditions. In the transport regime, the entanglement exhibits a clear switching threshold and various limits due to suppression of tunneling by Quantum Zeno localisation or by an interaction induced energy gap. We also calculate quantum noise spectra and discuss the inter-dot current correlation as an indicator of the entanglement in transport experiments.

  4. Comparative study of 2-group P1 and diffusion theories for the calculation of the neutron noise in 1D 2-region systems

    E-Print Network [OSTI]

    Demazière, Christophe

    Comparative study of 2-group P1 and diffusion theories for the calculation of the neutron noise of the neutron flux around its mean value, is calculated in 2-group P1 and diffusion theories for a 2-region slab reactor using Green's function technique. The applicability of diffusion theory for different types

  5. Characterizing the noise produced by hard disk drives

    E-Print Network [OSTI]

    Cherniak, Bruce Marshall

    1991-01-01T23:59:59.000Z

    Detection of noise emanating from machinery is not a novel concept. Various methods of acoustic and vibration measurement have been applied to systems ranging from small fan motors to the environmental effects of traffic noise, table l. Among the more... Indexed Noise Levels Small Fan Motors Acoustic and Vibration S ctral Anal sis Automated Inspection S stem While the goal of such research has not been to find annoying or even noisy components, automated vibration signature analysis is a useful tool...

  6. on Active Resonance and Flutter Suppression Techniques John B. Moore, PhD, FIEEE, FTS, Professor, Dept. of Systems Engineering, Australiwt-ffational University

    E-Print Network [OSTI]

    Moore, John Barratt

    . of Systems Engineering, .Ausiraiian Nationai University . 1. Introduction Reafistic aircmft models for controller design purposes are of very f@ ordm and normally with muftiple-inputs and mukiple- outputs of aircraft controller design, a namraf application for adaptive augmentation of a "robust" design

  7. The physics of phase-noise mitigation : signal and filtering using microwave-photonic generation links

    E-Print Network [OSTI]

    Loh, William, Ph. D. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    The spectral purity of every oscillator system is limited by noise. This thesis explores the physics and measurements of noise fundamental to oscillators operating in the electrical and optical domains. Our analysis leads ...

  8. cjue2e3.tmp

    Office of Scientific and Technical Information (OSTI)

    and claims to have supplied silencer and noise suppression systems to the Navy and the Air Force. The brochure suggests experience in building noise suppression systems for...

  9. A Kalman filter for feedback control of rotating external kink instabilities in the presence of noise

    SciTech Connect (OSTI)

    Hanson, Jeremy M.; De Bono, Bryan; Levesque, Jeffrey P.; Mauel, Michael E.; Maurer, David A.; Navratil, Gerald A.; Pedersen, Thomas Sunn; Shiraki, Daisuke [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); James, Royce W. [U. S. Coast Guard Academy, New London, Connecticut 06320 (United States) and Stevens Institute of Technology, Castle Point on Hudson, Hoboken, New Jersey 07030 (United States)

    2009-05-15T23:59:59.000Z

    The simulation and experimental optimization of a Kalman filter feedback control algorithm for n=1 tokamak external kink modes are reported. In order to achieve the highest plasma pressure limits in ITER, resistive wall mode stabilization is required [T. C. Hender et al., Nucl. Fusion 47, S128 (2007)] and feedback algorithms will need to distinguish the mode from noise due to other magnetohydrodynamic activity. The Kalman filter contains an internal model that captures the dynamics of a rotating, growing n=1 mode. This model is actively compared with real-time measurements to produce an optimal estimate for the mode's amplitude and phase. On the High Beta Tokamak-Extended Pulse experiment [T. H. Ivers et al., Phys. Plasmas 3, 1926 (1996)], the Kalman filter algorithm is implemented using a set of digital, field-programmable gate array controllers with 10 {mu}s latencies. Signals from an array of 20 poloidal sensor coils are used to measure the n=1 mode, and the feedback control is applied using 40 poloidally and toroidally localized control coils. The feedback system with the Kalman filter is able to suppress the external kink mode over a broad range of phase angles between the sensed mode and applied control field. Scans of filter parameters show good agreement between simulation and experiment, and feedback suppression and excitation of the kink mode are enhanced in experiments when a filter made using optimal parameters from the scans is used.

  10. Exact decoherence dynamics of $1/f$ noise

    E-Print Network [OSTI]

    Md. Manirul Ali; Ping-Yuan Lo; Wei-Min Zhang

    2014-10-06T23:59:59.000Z

    In this paper, we investigate the exact decoherence dynamics of a superconducting resonator coupled to an electromagnetic reservoir characterized by the $1/f$ noise at finite temperature, where a full quantum description of the environment with $1/f^{x}$ noise (with $x \\approx 1$) is presented. The exact master equation and the associated non-equilibrium Green's functions are solved exactly for such an open system. We show a clear signal of non-Markovian dynamics induced purely by $1/f$ noise. Our analysis is also applicable to another nano/micro mechanical oscillators. Finally, we demonstrate the non-Markovian decoherence dynamics of photon number superposition states using Wigner distribution that could be measured in experiments.

  11. Abstract--A low noise optical sensor and biocompatible microscale optical filters for integrated fluorescence sensors

    E-Print Network [OSTI]

    Maryland at College Park, University of

    Abstract--A low noise optical sensor and biocompatible microscale optical filters for integrated sensors. The transmission ratio in the pass-band and suppression ratio in the stop-band of the optical and of the optical filter. Test results comparing sensor and filter performance with competing technologies

  12. Statistical CT noise reduction with multiscale decomposition and penalized weighted least squares in the projection domain

    SciTech Connect (OSTI)

    Tang Shaojie; Tang Xiangyang [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Dr., C-5018, Atlanta, Georgia 30322 (United States); School of Automation, Xi'an University of Posts and Telecommunications, Xi'an, Shaanxi 710121 (China); Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Dr., C-5018, Atlanta, Georgia 30322 (United States)

    2012-09-15T23:59:59.000Z

    Purposes: The suppression of noise in x-ray computed tomography (CT) imaging is of clinical relevance for diagnostic image quality and the potential for radiation dose saving. Toward this purpose, statistical noise reduction methods in either the image or projection domain have been proposed, which employ a multiscale decomposition to enhance the performance of noise suppression while maintaining image sharpness. Recognizing the advantages of noise suppression in the projection domain, the authors propose a projection domain multiscale penalized weighted least squares (PWLS) method, in which the angular sampling rate is explicitly taken into consideration to account for the possible variation of interview sampling rate in advanced clinical or preclinical applications. Methods: The projection domain multiscale PWLS method is derived by converting an isotropic diffusion partial differential equation in the image domain into the projection domain, wherein a multiscale decomposition is carried out. With adoption of the Markov random field or soft thresholding objective function, the projection domain multiscale PWLS method deals with noise at each scale. To compensate for the degradation in image sharpness caused by the projection domain multiscale PWLS method, an edge enhancement is carried out following the noise reduction. The performance of the proposed method is experimentally evaluated and verified using the projection data simulated by computer and acquired by a CT scanner. Results: The preliminary results show that the proposed projection domain multiscale PWLS method outperforms the projection domain single-scale PWLS method and the image domain multiscale anisotropic diffusion method in noise reduction. In addition, the proposed method can preserve image sharpness very well while the occurrence of 'salt-and-pepper' noise and mosaic artifacts can be avoided. Conclusions: Since the interview sampling rate is taken into account in the projection domain multiscale decomposition, the proposed method is anticipated to be useful in advanced clinical and preclinical applications where the interview sampling rate varies.

  13. Long Response to Scheuer-Yariv: "A Classical Key-Distribution System based on Johnson (like) noise - How Secure?", physics/0601022

    E-Print Network [OSTI]

    Laszlo B. Kish

    2006-07-28T23:59:59.000Z

    This is the longer (partially unpublished) version of response; the shorter version (http://arxiv.org/abs/physics/0605013) is published in Physics Letters A. We point out that the claims in the comment-paper of Scheuer and Yariv are either irrelevant or incorrect. We first clarify what the security of a physically secure layer means. The idealized Kirchoff-loop-Johnson-like-noise (KLJN) scheme is totally secure therefore it is more secure than idealized quantum communication schemes which can never be totally secure because of the inherent noise processes in those communication schemes and the statistical nature of eavesdropper detection based on error statistics. On the other hand, with sufficient resources, a practical/non-ideal realization of the KLJN cipher can arbitrarily approach the idealized limit and outperform even the idealized quantum communicator schemes because the non-ideality-effects are determined and controlled by the design. The cable resistance issue analyzed by Scheuer and Yariv is a good example for that because the eavesdropper has insufficient time window to build a sufficient statistics and the actual information leak can be designed. We show that Scheuer's and Yariv's numerical result of 1% voltage drop supports higher security than that of quantum communicators. Moreover, choosing thicker or shorter wires can arbitrarily reduce this voltage drop further; the same conclusion holds even according to the equations of Scheuer and Yariv.

  14. Background Suppression Effects on Signal Estimation

    SciTech Connect (OSTI)

    Burr, Tom [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    Gamma detectors at border crossings are intended to detect illicit nuclear material. One performance challenge involves the fact that vehicles suppress the natural background, thus potentially reducing detection probability for threat items. Methods to adjust for background suppression have been considered in related but different settings. Here, methods to adjust for background suppression are tested in the context of signal estimation. Adjustment methods include several clustering options. We find that for the small-to-moderate suppression magnitudes exhibited in the analyzed data, suppression adjustment is only moderatel helpful in locating the signal peak, and in estimating its width or magnitude.

  15. Blast Effects Suppression System - Energy Innovation Portal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced Materials Find FindRewind Generator Rewind Denison PowerhouseBlast

  16. FINAL REPORT FOR PSerc PROJECT Avoiding and Suppressing

    E-Print Network [OSTI]

    Dobson, Ian

    FINAL REPORT FOR PSerc PROJECT Avoiding and Suppressing Oscillations December 1999 POWER SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.4 Summary guide to this report . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 Arbitrary topology networks with high order machine models . . . . . . . . . 43 5.5 The eigenvalue solution

  17. An integrated phase noise measurement bench for on-chip characterization of resonators and VCOs

    E-Print Network [OSTI]

    Boyer, Edmond

    a splitter with quadrature outputs, a phase detector, a low noise baseband amplifier and, if necessary on active references or long delay lines, including low noise amplifiers and phase detectors. The ability) or a two port system, such as an amplifier, a digital circuit... In the first case, the phase noise

  18. A Broadband Low-Noise-Amplifier Luca Daniel and Manolis Terrovitis

    E-Print Network [OSTI]

    Daniel, Luca

    describes the design of a two-stage broadband low-noise-amplifier (LNA) for the frequency range from 3 GHzA Broadband Low-Noise-Amplifier Luca Daniel and Manolis Terrovitis May 1999 Department dominates the system sensitivity. The primary objective of this work is to achieve low noise figure and flat

  19. IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS--II: ANALOG AND DIGITAL SIGNAL PROCESSING, VOL. 48, NO. 2, FEBRUARY 2001 151 Analysis of 1=f Noise in Switched MOSFET Circuits

    E-Print Network [OSTI]

    El Gamal, Abbas

    , 1 noise in MOSFETs was of concern mainly in the design of low-frequency linear analog cir- cuits, 1 noise has become of greater concern in a wider range of circuit designs. Scaling has enabled, FEBRUARY 2001 151 Analysis of 1=f Noise in Switched MOSFET Circuits Hui Tian and Abbas El Gamal, Fellow

  20. Noise | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRoseConcerns Jump to:Neppelsource History(CTIFarm II Jump to:Noise Jump

  1. Environmental gravitational decoherence and a tensor noise model

    E-Print Network [OSTI]

    Fumika Suzuki; Friedemann Queisser

    2015-02-04T23:59:59.000Z

    We discuss decrease of coherence in a massive system due to the emission of gravitational waves. In particular we investigate environmental gravitational decoherence in the context of an interference experiment. The time-evolution of the reduced density matrix is solved analytically using the path-integral formalism. Furthermore, we study the impact of a tensor noise onto the coherence properties of massive systems. We discuss that a particular choice of tensor noise shows similarities to a mechanism proposed by Diosi and Penrose.

  2. Environmental gravitational decoherence and a tensor noise model

    E-Print Network [OSTI]

    Suzuki, Fumika

    2015-01-01T23:59:59.000Z

    We discuss decrease of coherence in a massive system due to the emission of gravitational waves. In particular we investigate environmental gravitational decoherence in the context of an interference experiment. The time-evolution of the reduced density matrix is solved analytically using the path-integral formalism. Furthermore, we study the impact of a tensor noise onto the coherence properties of massive systems. We discuss that a particular choice of tensor noise shows similarities to a mechanism proposed by Diosi and Penrose.

  3. Low-noise SQUID

    DOE Patents [OSTI]

    Dantsker, Eugene (Torrance, CA); Clarke, John (Berkeley, CA)

    2000-01-01T23:59:59.000Z

    The present invention comprises a high-transition-temperature superconducting device having low-magnitude low-frequency noise-characteristics in magnetic fields comprising superconducting films wherein the films have a width that is less than or equal to a critical width, w.sub.C, which depends on an ambient magnetic field. For operation in the Earth's magnetic field, the critical width is about 6 micrometers (.mu.m). When made with film widths of about 4 .mu.m an inventive high transition-temperature, superconducting quantum interference device (SQUID) excluded magnetic flux vortices up to a threshold ambient magnetic field of about 100 microTesla (.mu.T). SQUIDs were fabricated having several different film strip patterns. When the film strip width was kept at about 4 .mu.m, the SQUIDs exhibited essentially no increase in low-frequency noise, even when cooled in static magnetic fields of magnitude up to 100 .mu.T. Furthermore, the mutual inductance between the inventive devices and a seven-turn spiral coil was at least 85% of that for inductive coupling to a conventional SQUID.

  4. Newtonian-noise cancellation in full-tensor gravitational-wave detectors

    E-Print Network [OSTI]

    Harms, Jan

    2015-01-01T23:59:59.000Z

    Terrestrial gravity noise, also known as Newtonian noise, produced by ambient seismic and infrasound fields will pose one of the main sensitivity limitations in low-frequency, ground-based, gravitational-wave (GW) detectors. It was estimated that this noise foreground needs to be suppressed by about 3 -- 5 orders of magnitude in the frequency band 10\\,mHz to 1\\,Hz, which will be extremely challenging. In this article, we present a new approach that greatly facilitates cancellation of gravity noise in full-tensor GW detectors. The method uses optimal combinations of tensor channels and environmental sensors such as seismometers and microphones to reduce gravity noise. It makes explicit use of the direction of propagation of a GW, and can therefore either be implemented in directional searches for GWs or in observations of known sources. We show that suppression of the Newtonian-noise foreground is greatly facilitated using the extra strain channels in full-tensor GW detectors. Only a modest number of auxiliary...

  5. Issues in Numerical Simulation of Fire Suppression

    SciTech Connect (OSTI)

    Tieszen, S.R.; Lopez, A.R.

    1999-04-12T23:59:59.000Z

    This paper outlines general physical and computational issues associated with performing numerical simulation of fire suppression. Fire suppression encompasses a broad range of chemistry and physics over a large range of time and length scales. The authors discuss the dominant physical/chemical processes important to fire suppression that must be captured by a fire suppression model to be of engineering usefulness. First-principles solutions are not possible due to computational limitations, even with the new generation of tera-flop computers. A basic strategy combining computational fluid dynamics (CFD) simulation techniques with sub-grid model approximations for processes that have length scales unresolvable by gridding is presented.

  6. Suppression of Stable Flies on Cattle

    E-Print Network [OSTI]

    Tomberlin, Jeffery K.

    2004-07-01T23:59:59.000Z

    Large populations of stable flies can substantially reduce the income of beef and dairy producers. This publication explains how to suppress stable flies effectively and economically....

  7. 466 IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING, VOL. 11, NO. 5, SEPTEMBER 2003 Noise Spectrum Estimation in Adverse Environments

    E-Print Network [OSTI]

    Cohen, Israel

    --Noise spectrum estimation is a fundamental compo- nent of speech enhancement and speech recognition systems into a speech enhancement system achieves improved speech quality and lower residual noise. I. INTRODUCTION NOISE POWER spectrum estimation is a fundamental component of speech enhancement and speech recog

  8. Quantum refrigerator driven by current noise

    E-Print Network [OSTI]

    Yi-Xin Chen; Sheng-Wen Li

    2011-04-13T23:59:59.000Z

    We proposed a scheme to implement a self-contained quantum refrigerator system composed of three rf-SQUID qubits, or rather, flux-biased phase qubits. The three qubits play the roles of the target, the refrigerator and the heat engine respectively. We provide different effective temperatures for the three qubits, by imposing external current noises of different strengths. The differences of effective temperatures give rise to the flow of free energy and that drives the refrigerator system to cool down the target. We also show that the efficiency of the system approaches the Carnot efficiency.

  9. Numerical evaluation of propeller noise, including non-linear effects

    E-Print Network [OSTI]

    White, Terence Alan

    1985-01-01T23:59:59.000Z

    University Chairman of Advisor y Commitee: Dr. Kenneth Korkan Using the transonic flow field(s) generated by the NASPROP-E computer code for an eight blade SR3-series propeller, a method is investigated to calculate the total noise values and frequency... in three dimensions, and the influence of the damping on the calculated noise values is investigated. Since the flow field includes the wave systems near the blade surface, the quadr upole noise sour ce term is accounted for as are the monopole...

  10. 1/f noise and other systematic effects in the Planck-LFI radiometers

    E-Print Network [OSTI]

    Michael Seiffert; Aniello Mennella; Carlo Burigana; Nazzareno Mandolesi; Marco Bersanelli; Peter Meinhold; Phil Lubin

    2002-06-06T23:59:59.000Z

    We use an analytic approach to study the susceptibility of the Planck Low Frequency Instrument radiometers to various systematic effects. We examine the effects of fluctuations in amplifier gain, in amplifier noise temperature and in the reference load temperature. We also study the effect of imperfect gain modulation, non-ideal matching of radiometer parameters, imperfect isolation in the two legs of the radiometer and back-end 1/f noise. We find that with proper gain modulation 1/f gain fluctuations are suppressed, leaving fluctuations in amplifier noise temperature as the main source of 1/f noise. We estimate that with a gain modulation factor within +- 1% of its ideal value the overall 1/f knee frequency will be relatively small (< 0.1 Hz).

  11. Blue whale response to underwater noise from commercial ships

    E-Print Network [OSTI]

    McKenna, Megan Frances

    2011-01-01T23:59:59.000Z

    Accessing Noise Impact Acoustic pollution from ship noise isConcerns regarding acoustic noise pollution from ships ariseNoise pollution level metric for acoustic data collected at

  12. Salt-and-Pepper Noise Removal by Median-type Noise Detectors and

    E-Print Network [OSTI]

    Chan, Raymond

    1 Salt-and-Pepper Noise Removal by Median-type Noise Detectors and Detail-preserving Regularization for removing salt-and-pepper impulse noise. In the first phase, an adaptive median filter is used to identify remove salt-and-pepper-noise with noise level as high as 90%. Index Terms Impulse noise, adaptive median

  13. Quantifying precipitation suppression due to air Pollution

    E-Print Network [OSTI]

    Li, Zhanqing

    Quantifying precipitation suppression due to air Pollution First author: Amir Givati The Hebrew January 2004 #12;ABSTRACT: Urban and industrial air pollution has been shown qualitatively to suppress of the ratio of hill/coast precipitation during the 20th century in polluted areas in line with the increasing

  14. Power supply noise in delay testing

    E-Print Network [OSTI]

    Wang, Jing

    2009-05-15T23:59:59.000Z

    area makes designs more vulnerable to noise problems [17]. Charge sharing is one of the problems that may cause failure in dynamic logic circuits due to their low noise immunity. Charge-sharing noise is produced by charge redistribution between...

  15. Thermal noise engines

    E-Print Network [OSTI]

    Laszlo B. Kish

    2011-01-10T23:59:59.000Z

    Electrical heat engines driven by the Johnson-Nyquist noise of resistors are introduced. They utilize Coulomb's law and the fluctuation-dissipation theorem of statistical physics that is the reverse phenomenon of heat dissipation in a resistor. No steams, gases, liquids, photons, combustion, phase transition, or exhaust/pollution are present here. In these engines, instead of heat reservoirs, cylinders, pistons and valves, resistors, capacitors and switches are the building elements. For the best performance, a large number of parallel engines must be integrated to run in a synchronized fashion and the characteristic size of the elementary engine must be at the 10 nanometers scale. At room temperature, in the most idealistic case, a two-dimensional ensemble of engines of 25 nanometer characteristic size integrated on a 2.5x2.5 cm silicon wafer with 12 Celsius temperature difference between the warm-source and the cold-sink would produce a specific power of about 0.4 Watt. Regular and coherent (correlated-cylinder states) versions are shown and both of them can work in either four-stroke or two-stroke modes. The coherent engines have properties that correspond to coherent quantum heat engines without the presence of quantum coherence. In the idealistic case, all these engines have Carnot efficiency, which is the highest possible efficiency of any heat engine, without violating the second law of thermodynamics.

  16. Effects of optical feedback with dispersive loss on the amplitude noise and relaxation resonance of semiconductor lasers

    SciTech Connect (OSTI)

    Kitching, J.; Boyd, R.; Yariv, A. [California Inst. of Technology, Pasadena, CA (United States). Dept. of Applied Physics; Shevy, Y. [Univ. of Miami, Coral Gables, FL (United States). Dept. of Physics

    1994-12-31T23:59:59.000Z

    Optical feedback from an external cavity containing an element of dispersive loss was used to reduce the amplitude noise of a semiconductor laser. At feedback levels of P{sub fb}/P{sub out} {approx} 10{sup {minus}2}, a maximum amplitude noise reduction of 16 dB was measured close to threshold but the potential for reduction was reduced considerably at higher injection currents as the laser noise approached the shot noise limit. In addition, the threshold current decreased and the linewidth was reduced to 10 kHz. The relaxation oscillation peak in the amplitude noise spectrum was also found to be dramatically suppressed and the authors find evidence that the relaxation resonance can be moved to much higher frequencies using optical feedback techniques.

  17. Low noise charge ramp electrometer

    DOE Patents [OSTI]

    Morgan, John P. (Idaho Falls, ID); Piper, Thomas C. (Idaho Falls, ID)

    1992-01-01T23:59:59.000Z

    An electrometer capable of measuring small currents without the use of a feedback resistor which tends to contribute a large noise factor to the measured data. The electrometer eliminates the feedback resistor through the use of a feedback capacitor located across the electrometer amplifier. The signal from the electrometer amplifier is transferred to a electrometer buffer amplifier which serves to transfer the signal to several receptors. If the electrometer amplifier is approaching saturation, the buffer amplifier signals a reset discriminator which energizes a coil whose magnetic field closes a magnetic relay switch which in turn resets or zeros the feedback capacitor. In turn, a reset complete discriminator restarts the measurement process when the electrometer amplifier approaches its initial condition. The buffer amplifier also transmits the voltage signal from the electrometer amplifier to a voltage-to-frequency converter. The signals from the voltage-to-frequency converter are counted over a fixed period of time and the information is relayed to a data processor. The timing and sequencing of the small current measuring system is under the control of a sequence control logic unit.

  18. Another approach to the study of phase noise in electrical oscillators

    E-Print Network [OSTI]

    Carlà, Marcello

    2015-01-01T23:59:59.000Z

    The mechanism at the base of phase noise generation in electrical oscillators is reexamined from first principles. The well known Lorentzian spectral power distribution is obtained, together with a clearcut expression for the line-width parameter. The mechanism of suppression of the amplitude fluctuations and its effects are discussed and the true role of the figure of merit $Q_0$ of the resonator is restated. The up conversion of low frequency components from a non-white noise source is also considered. A number of simple numerical experiments is presented to illustrate and clarify the mathematical results.

  19. Another approach to the study of phase noise in electrical oscillators

    E-Print Network [OSTI]

    Marcello Carlà

    2015-04-23T23:59:59.000Z

    The mechanism at the base of phase noise generation in electrical oscillators is reexamined from first principles. The well known Lorentzian spectral power distribution is obtained, together with a clearcut expression for the line-width parameter. The mechanism of suppression of the amplitude fluctuations and its effects are discussed and the true role of the figure of merit $Q_0$ of the resonator is restated. The up conversion of low frequency components from a non-white noise source is also considered. A number of simple numerical experiments is presented to illustrate and clarify the mathematical results.

  20. Techniques for noise suppression and robust control in spin-based quantum information processors

    E-Print Network [OSTI]

    Borneman, Troy William

    2013-01-01T23:59:59.000Z

    Processing information quantum mechanically allows the relatively efficient solution of many important problems thought to be intractable on a classical computer. A primary challenge in experimentally implementing a quantum ...

  1. Aerodynamics of Fan Flow Deflectors for Jet Noise Suppression Dimitri Papamoschou

    E-Print Network [OSTI]

    Papamoschou, Dimitri

    operating at static conditions. The vane airfoils are subjected to an externally imposed favorable pressure = turbulent kinetic energy L = lift force M = Mach number p = static pressure q = dynamic pressure from high-bypass engines involves the installation of chevron mixers on the exhaust nozzles [1

  2. Noise as Information for Illiquidity

    E-Print Network [OSTI]

    Hu, Grace Xing

    We propose a market-wide liquidity measure by exploiting the connection between the amount of arbitrage capital in the market and observed “noise” in U.S. Treasury bonds—the shortage of arbitrage capital allows yields to ...

  3. Propofol and sevoflurane induce distinct burst suppression patterns in rats

    E-Print Network [OSTI]

    Westover, M. Brandon

    Burst suppression is an EEG pattern characterized by alternating periods of high-amplitude activity (bursts) and relatively low amplitude activity (suppressions). Burst suppression can arise from several different pathological ...

  4. Multiple phase estimation for arbitrary pure states under white noise

    E-Print Network [OSTI]

    Yao Yao; Li Ge; Xing Xiao; Xiaoguang Wang; C. P. Sun

    2014-09-08T23:59:59.000Z

    In any realistic quantum metrology scenarios, the ultimate precision in the estimation of parameters is limited not only by the so-called Heisenberg scaling, but also the environmental noise encountered by the underlying system. In the context of quantum estimation theory, it is of great significance to carefully evaluate the impact of a specific type of noise on the corresponding quantum Fisher information (QFI) or quantum Fisher information matrix (QFIM). Here we investigate the multiple phase estimation problem for a natural parametrization of arbitrary pure states under white noise. We obtain the explicit expression of the symmetric logarithmic derivative (SLD) and hence the analytical formula of QFIM. Moreover, the attainability of the quantum Cram\\'{e}r-Rao bound (QCRB) is confirmed by the commutability of SLDs and the optimal estimators are elucidated for the experimental purpose. These findings generalize previously known partial results and highlight the role of white noise in quantum metrology.

  5. Numerical integration of thermal noise in relativistic hydrodynamics

    E-Print Network [OSTI]

    Clint Young

    2013-06-03T23:59:59.000Z

    Thermal fluctuations affect the dynamics of systems near critical points, the evolution of the early universe, and two-particle correlations in heavy-ion collisions. For the latter, numerical simulations of nearly-ideal, relativistic fluids are necessary. The correlation functions of noise in relativistic fluids are calculated, stochastic integration of the noise in 3+1-dimensional viscous hydrodynamics is implemented, and the effect of noise on observables in heavy-ion collisions is discussed. Thermal fluctuations will cause significant variance in the event-by-event distributions of integrated v2 while changing average values even when using the same initial conditions, suggesting that including thermal noise will lead to refitting of the hydrodynamical parameters with implications for understanding the physics of hot QCD.

  6. Resolving small signal measurements in experimental plasma environments using calibrated subtraction of noise signals

    SciTech Connect (OSTI)

    Fimognari, P. J., E-mail: PJFimognari@XanthoTechnologies.com; Demers, D. R. [Xantho Technologies, LLC, Madison, Wisconsin 53705 (United States); Chen, X. [Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830 (United States); Schoch, P. M. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2014-11-15T23:59:59.000Z

    The performance of many diagnostic and control systems within fusion and other fields of research are often detrimentally affected by spurious noise signals. This is particularly true for those (such as radiation or particle detectors) working with very small signals. Common sources of radiated and conducted noise in experimental fusion environments include the plasma itself and instrumentation. The noise complicates data analysis, as illustrated by noise on signals measured with the heavy ion beam probe (HIBP) installed on the Madison Symmetric Torus. The noise is time-varying and often exceeds the secondary ion beam current (in contrast with previous applications). Analysis of the noise identifies the dominant source as photoelectric emission from the detectors induced by ultraviolet light from the plasma. This has led to the development of a calibrated subtraction technique, which largely removes the undesired temporal noise signals from data. The advantages of the technique for small signal measurement applications are demonstrated through improvements realized on HIBP fluctuation measurements.

  7. PHASE NOISE IN MICROWAVE OSCILLATORS AND AMPLIFIERS

    E-Print Network [OSTI]

    Popovic, Zoya

    presents analysis and measurements of phase noise in oscilla- tors and amplifiers. Low phase noise- multaneous small size, low phase noise, DC power consumption and thermal drift is presented. Design stepsPHASE NOISE IN MICROWAVE OSCILLATORS AND AMPLIFIERS by MILOS JANKOVI´C B.E., University of Arkansas

  8. 5th International Meeting Wind Turbine Noise

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 5th International Meeting on Wind Turbine Noise Denver 28 ­ 30 August 2013 Wind Turbine Noise Broadband noise generated aerodynamically is the dominant noise source for a modern wind turbine(Brooks et turbines . First, a wall pressure spectral model proposed recently by Rozenberg, Robert and Moreau

  9. 2410 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 47, NO. 12, DECEMBER 2000 An Accurate and Efficient High Frequency Noise

    E-Print Network [OSTI]

    Dutton, Robert W.

    silicon chip. Recent work has demonstrated the viability of CMOS low noise amplifiers (LNAs) [1 frequency (RF) design applications owing to the promise of integrating electronic systems on a single claimed that the fundamental noise per- formance of CMOS amplifiers would be limited by the noise sources

  10. Walsh-synthesized noise-filtering quantum logic

    E-Print Network [OSTI]

    H. Ball; M. J. Biercuk

    2014-10-07T23:59:59.000Z

    We study a novel class of open-loop control protocols constructed to perform arbitrary nontrivial single-qubit logic operations robust against time-dependent non-Markovian noise. Amplitude and phase modulation protocols are crafted leveraging insights from functional synthesis and the basis set of Walsh functions. We employ the experimentally validated generalized filter-transfer function formalism in order to find optimized control protocols for target operations in SU(2) by defining a cost function for the filter-transfer function to be minimized through the applied modulation. Our work details the various techniques by which we define and then optimize the filter-synthesis process in the Walsh basis, including the definition of specific analytic design rules which serve to efficiently constrain the available synthesis space. This approach yields modulated-gate constructions consisting of chains of discrete pulse-segments of arbitrary form, whose modulation envelopes possess intrinsic compatibility with digital logic and clocking. We derive novel families of Walsh-modulated noise filters designed to suppress dephasing and coherent amplitude-damping noise, and describe how well-known sequences derived in NMR also fall within the Walsh-synthesis framework. Finally, our work considers the effects of realistic experimental constraints such as limited modulation bandwidth on achievable filter performance.

  11. Rotary rail car dumper coal-dust-suppressant experiment

    SciTech Connect (OSTI)

    Meyer, J.H.; Hereford, L.G.; Lenkevich, M.J.

    1984-10-01T23:59:59.000Z

    A rotary rail car dumper dust-suppressant experiment was performed at the PEPCO Morgantown Power Plant coal handling facility, Newburg, Maryland during the late summer and early fall of 1983. From previous observations of rotary coal car dumping, it was observed that large amounts of dust, especially for washed coal, were generated from the exposed top layer of coal in the open rail car. An overhead spray system using water and surfactant was used to examine the effectiveness of surface wetting just before dumping. High volume sampling at both the entrance and exit doorways of the dumper shed was used to determine the coal dust reduction. A total of 23 tests was performed, of which 16 tests were considered valid. All data were normalized for background, number of tons dumped and sampling time. The use of an overhead spray system can substantially suppress fugitive coal dust generated by rotary rail car dumping of coal. A water and surfactant mixture provided coal-dust-suppressant efficiencies ranging from 47% to 79% with an average of 61% for a combination of washed, mixed, and unwashed coal.

  12. Listening to Noise

    E-Print Network [OSTI]

    Michael G. Endres; David B. Kaplan; Jong-Wan Lee; Amy N. Nicholson

    2011-12-17T23:59:59.000Z

    We show how sign problems in simulations of many-body systems can manifest themselves in the form of heavy-tailed correlator distributions, similar to what is seen in electron propagation through disordered media. We propose an alternative statistical approach for extracting ground state energies in such systems, illustrating the method with a toy model and with lattice data for unitary fermions and for baryons in QCD.

  13. Noise clinic: some good and bad patients Multiscale signal-dependent noise model

    E-Print Network [OSTI]

    Mayberry, Marty

    Noise clinic: some good and bad patients Multiscale signal-dependent noise model Noise estimation recipes illustrated by DCT References The noise clinic Miguel Colom, Marc Lebrun, Jean-Michel Morel CMLA, ENS Cachan Saarbr¨ucken, September 2013 Miguel Colom, Marc Lebrun, Jean-Michel Morel The noise clinic

  14. Spin noise spectroscopy of ZnO

    SciTech Connect (OSTI)

    Horn, H.; Berski, F.; Hübner, J.; Oestreich, M. [Institute for Solid State Physics, Leibniz Universität Hannover, Appelstr. 2, 30167 Hannover (Germany); Balocchi, A.; Marie, X. [INSA-CNRS-UPS, LPCNO, Université de Toulouse, 135 Av. de Rangueil, 31077 Toulouse (France); Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A. [Institute of Semiconductor Technology, Technische Universität Braunschweig, Hans-Sommer-Straße 66, 38106 Braunschweig (Germany)

    2013-12-04T23:59:59.000Z

    We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.

  15. GNOSIS: THE FIRST INSTRUMENT TO USE FIBER BRAGG GRATINGS FOR OH SUPPRESSION

    SciTech Connect (OSTI)

    Trinh, Christopher Q.; Ellis, Simon C.; Bland-Hawthorn, Joss; Bryant, Julia; O'Byrne, John [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia); Lawrence, Jon S.; Horton, Anthony J.; Shortridge, Keith; Case, Scott; Colless, Matthew; Gers, Luke; Lee, Steve; Miziarski, Stan [Australian Astronomical Observatory, 105 Delhi Road, North Ryde, P.O. Box 915, NSW 1670 (Australia); Leon-Saval, Sergio G. [Institute of Photonics and Optical Science, School of Physics, University of Sydney, NSW 2006 (Australia); Couch, Warrick; Glazebrook, Karl [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122 (Australia); Freeman, Kenneth [Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, ACT 2611 (Australia); Loehmannsroeben, Hans-Gerd [innoFSPEC-Institut fuer Chemie/Physikalische Chemie, Universitaet Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam-Golm (Germany); Haynes, Roger; Roth, Martin M., E-mail: c.trinh@physics.usyd.edu.au [innoFSPEC-Leibniz-Institut fuer Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); and others

    2013-02-01T23:59:59.000Z

    The near-infrared is an important part of the spectrum in astronomy, especially in cosmology because the light from objects in the early universe is redshifted to these wavelengths. However, deep near-infrared observations are extremely difficult to make from ground-based telescopes due to the bright background from the atmosphere. Nearly all of this background comes from the bright and narrow emission lines of atmospheric hydroxyl (OH) molecules. The atmospheric background cannot be easily removed from data because the brightness fluctuates unpredictably on short timescales. The sensitivity of ground-based optical astronomy far exceeds that of near-infrared astronomy because of this long-standing problem. GNOSIS is a prototype astrophotonic instrument that utilizes 'OH suppression fibers' consisting of fiber Bragg gratings and photonic lanterns to suppress the 103 brightest atmospheric emission doublets between 1.47 and 1.7 {mu}m. GNOSIS was commissioned at the 3.9 m Anglo-Australian Telescope with the IRIS2 spectrograph to demonstrate the potential of OH suppression fibers, but may be potentially used with any telescope and spectrograph combination. Unlike previous atmospheric suppression techniques GNOSIS suppresses the lines before dispersion and in a manner that depends purely on wavelength. We present the instrument design and report the results of laboratory and on-sky tests from commissioning. While these tests demonstrated high throughput ( Almost-Equal-To 60%) and excellent suppression of the skylines by the OH suppression fibers, surprisingly GNOSIS produced no significant reduction in the interline background and the sensitivity of GNOSIS+IRIS2 is about the same as IRIS2. It is unclear whether the lack of reduction in the interline background is due to physical sources or systematic errors as the observations are detector noise dominated. OH suppression fibers could potentially impact ground-based astronomy at the level of adaptive optics or greater. However, until a clear reduction in the interline background and the corresponding increasing in sensitivity is demonstrated optimized OH suppression fibers paired with a fiber-fed spectrograph will at least provide a real benefit at low resolving powers.

  16. An absolute Johnson noise thermometer

    E-Print Network [OSTI]

    Luca Callegaro; Vincenzo D'Elia; Marco Pisani; Alessio Pollarolo

    2009-01-30T23:59:59.000Z

    We developed an absolute Johnson noise thermometer (JNT), an instrument to measure the thermodynamic temperature of a sensing resistor, with traceability to voltage, resistance and frequency quantities. The temperature is measured in energy units, and can be converted to SI units (kelvin) with the accepted value of the Boltzmann constant kb; or, conversely, it can be employed to perform measurements at the triple point of water, and obtain a determination of kb. The thermometer is composed of a correlation spectrum analyzer an a calibrated noise source, both constructed around commercial mixed-signal boards. The calibrator generates a pseudorandom noise, by digital synthesis and amplitude scaling with inductive voltage dividers; the signal spectrum is a frequency comb covering the measurement bandwidth. JNT measurements at room temperature are compatible with those of a standard platinum resistance thermometer within the combined uncertainty of 60 ppm. A path towards future improvements of JNT accuracy is also sketched.

  17. Low-noise pulse conditioner

    DOE Patents [OSTI]

    Bird, David A. (Oak Ridge, TN)

    1983-01-01T23:59:59.000Z

    A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits.

  18. Low noise optical position sensor

    DOE Patents [OSTI]

    Spear, J.D.

    1999-03-09T23:59:59.000Z

    A novel optical position sensor is described that uses two component photodiodes electrically connected in parallel, with opposing polarities. A lens provides optical gain and restricts the acceptance angle of the detector. The response of the device to displacements of an optical spot is similar to that of a conventional bi-cell type position sensitive detector. However, the component photodiode design enables simpler electronic amplification with inherently less electrical noise than the bi-cell. Measurements by the sensor of the pointing noise of a focused helium-neon laser as a function of frequency demonstrate high sensitivity and suitability for optical probe beam deflection experiments. 14 figs.

  19. Low noise optical position sensor

    DOE Patents [OSTI]

    Spear, Jonathan David (Berkeley, CA)

    1999-01-01T23:59:59.000Z

    A novel optical position sensor is described that uses two component photodiodes electrically connected in parallel, with opposing polarities. A lens provides optical gain and restricts the acceptance angle of the detector. The response of the device to displacements of an optical spot is similar to that of a conventional bi-cell type position sensitive detector. However, the component photodiode design enables simpler electronic amplification with inherently less electrical noise than the bi-cell. Measurements by the sensor of the pointing noise of a focused helium-neon laser as a function of frequency demonstrate high sensitivity and suitability for optical probe beam deflection experiments.

  20. Laser Noise Reduction in Air

    E-Print Network [OSTI]

    Pierre Bejot; Jerome Kasparian; Estelle Salmon; Roland Ackermann; Nicolas Gisin; Jean-Pierre Wolf

    2006-08-09T23:59:59.000Z

    Fluctuations of the white-light supercontinuum produced by ultrashort laser pulses in selfguided filaments (spatio-temporal solitons) in air are investigated. We demonstrate that correlations exist within the white-light supercontinuum, and that they can be used to significantly reduce the laser intensity noise by filtering the spectrum. More precisely, the fundamental wavelength is anticorrelated with the wings of the continuum, while conjugated wavelength pairs on both sides of the continuum are strongly correlated. Spectral filtering of the continuum reduces the laser intensity noise by 1.2 dB, showing that fluctuations are rejected to the edges of the spectrum.

  1. High levels of environmental noise erode pair preferences in zebra finches: implications for noise pollution

    E-Print Network [OSTI]

    Swaddle, John

    for noise pollution JOHN P. SWADDLE & LAURA C. PAGE Institute for Integrative Bird Behavior Studies, Biology: acoustic; cognition; courtship; environmental noise; extrapair copulation; mate choice; perception

  2. Noise Properties of Rectifying Nanopores

    SciTech Connect (OSTI)

    Powell, M R; Sa, N; Davenport, M; Healy, K; Vlassiouk, I; Letant, S E; Baker, L A; Siwy, Z S

    2011-02-18T23:59:59.000Z

    Ion currents through three types of rectifying nanoporous structures are studied and compared for the first time: conically shaped polymer nanopores, glass nanopipettes, and silicon nitride nanopores. Time signals of ion currents are analyzed by power spectrum. We focus on the low-frequency range where the power spectrum magnitude scales with frequency, f, as 1/f. Glass nanopipettes and polymer nanopores exhibit non-equilibrium 1/f noise, thus the normalized power spectrum depends on the voltage polarity and magnitude. In contrast, 1/f noise in rectifying silicon nitride nanopores is of equilibrium character. Various mechanisms underlying the voltage-dependent 1/f noise are explored and discussed, including intrinsic pore wall dynamics, and formation of vortices and non-linear flow patterns in the pore. Experimental data are supported by modeling of ion currents based on the coupled Poisson-Nernst-Planck and Navier Stokes equations. We conclude that the voltage-dependent 1/f noise observed in polymer and glass asymmetric nanopores might result from high and asymmetric electric fields inducing secondary effects in the pore such as enhanced water dissociation.

  3. Engineering to Control Noise, Loading, and Optimal Operating Points

    SciTech Connect (OSTI)

    Mitchell R. Swartz

    2000-11-12T23:59:59.000Z

    Successful engineering of low-energy nuclear systems requires control of noise, loading, and optimum operating point (OOP) manifolds. The latter result from the biphasic system response of low-energy nuclear reaction (LENR)/cold fusion systems, and their ash production rate, to input electrical power. Knowledge of the optimal operating point manifold can improve the reproducibility and efficacy of these systems in several ways. Improved control of noise, loading, and peak production rates is available through the study, and use, of OOP manifolds. Engineering of systems toward the OOP-manifold drive-point peak may, with inclusion of geometric factors, permit more accurate uniform determinations of the calibrated activity of these materials/systems.

  4. THEORETICAL ISSUES IN J/PSI SUPPRESSION.

    SciTech Connect (OSTI)

    KHARZEEV,D.

    2006-11-14T23:59:59.000Z

    Two decades ago Matsui and Satz suggested that Debye screening in the quark-gluon plasma would result in J/{psi} suppression in heavy ion collisions. Much has happened in the subsequent years, and the picture of quark-gluon plasma at present is rapidly evolving - what does it imply for the J/{psi} suppression? What are the recent RHIC and SPS results trying to tell us? What else has to be done? This talk is an attempt to address these questions.

  5. Foundations for Cooperating with Control Noise in the Manipulation of Quantum Dynamics

    E-Print Network [OSTI]

    Feng Shuang; Herschel Rabitz; Mark Dykman

    2006-09-11T23:59:59.000Z

    This paper develops the theoretical foundations for the ability of a control field to cooperate with noise in the manipulation of quantum dynamics. The noise enters as run-to-run variations in the control amplitudes, phases and frequencies with the observation being an ensemble average over many runs as is commonly done in the laboratory. Weak field perturbation theory is developed to show that noise in the amplitude and frequency components of the control field can enhance the process of population transfer in a multilevel ladder system. The analytical results in this paper support the point that under suitable conditions an optimal field can cooperate with noise to improve the control outcome.

  6. adaptive hifu noise: Topics by E-print Network

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

    Noise Engineering Websites Summary: An Adaptive Noise Removal Approach for Restoration of Digital Images Corrupted by Multimodal Noise process compromises the performance of the...

  7. Power supply noise in delay testing 

    E-Print Network [OSTI]

    Wang, Jing

    2009-05-15T23:59:59.000Z

    As technology scales into the Deep Sub-Micron (DSM) regime, circuit designs have become more and more sensitive to power supply noise. Excessive noise can significantly affect the timing performance of DSM designs and cause ...

  8. Sensing Applications of Fluctuations and Noise

    E-Print Network [OSTI]

    Chang, Hung-Chih

    2011-02-22T23:59:59.000Z

    Noise and time-dependent fluctuations are usually undesirable signals. However, they have many applications. This dissertation deals with two kinds of sensing applications of fluctuation and noise: soil bulk density assessment and bacterium sensing...

  9. A Scalable Soft Spot Analysis Methodology for Compound Noise Effects in Nano-meter Circuits

    E-Print Network [OSTI]

    California at San Diego, University of

    A Scalable Soft Spot Analysis Methodology for Compound Noise Effects in Nano-meter Circuits Chong methodology to study the vulnerability of digital ICs exposed to nano-meter noise and transient soft errors. First, we define "softness" as an important characteristic to gauge system vulnerability. Then several

  10. Scanning Electron Microscope Image Signal-to-Noise Ratio Monitoring for Micro-Nanomanipulation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Scanning Electron Microscope Image Signal-to-Noise Ratio Monitoring for Micro ROBOTEX (ANR-10-EQPX-44-01) projects. Key words: Scanning electron microscope, signal-to-noise ratio system, scanning electron microscope (SEM) performs an important role in autonomous micro

  11. Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise

    E-Print Network [OSTI]

    Odam, Kofi

    Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise tracking (MPPT) algorithms for photovoltaic systems, including how noise affects both tracking speed-performance photovoltaic sys- tems. An intelligent controller adjusts the voltage, current, or impedance seen by a solar

  12. Effects of Noise on Rodent Physiology

    E-Print Network [OSTI]

    Baldwin, Ann Linda

    2007-01-01T23:59:59.000Z

    Noise on Rodent Physiology Ann Linda Baldwin University ofarticle should be addressed to Ann Baldwin, Department of

  13. Bayesian model selection applied to self-noise geoacoustic inversion

    E-Print Network [OSTI]

    Buckingham, Michael

    -water environments. In this paper, Gibbs sampling is used to obtain joint and marginal posterior probability of seabed geology, these parameters enable performance predictions for sonar systems operating in shallow, plant and hydrody- namic noise generated by the tow ship as a by-product of its normal operation is used

  14. Processing data base information having nonwhite noise

    DOE Patents [OSTI]

    Gross, Kenneth C. (Bolingbrook, IL); Morreale, Patricia (Park Ridge, IL)

    1995-01-01T23:59:59.000Z

    A method and system for processing a set of data from an industrial process and/or a sensor. The method and system can include processing data from either real or calculated data related to an industrial process variable. One of the data sets can be an artificial signal data set generated by an autoregressive moving average technique. After obtaining two data sets associated with one physical variable, a difference function data set is obtained by determining the arithmetic difference between the two pairs of data sets over time. A frequency domain transformation is made of the difference function data set to obtain Fourier modes describing a composite function data set. A residual function data set is obtained by subtracting the composite function data set from the difference function data set and the residual function data set (free of nonwhite noise) is analyzed by a statistical probability ratio test to provide a validated data base.

  15. Noise canceling in-situ detection

    DOE Patents [OSTI]

    Walsh, David O.

    2014-08-26T23:59:59.000Z

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  16. Charge Noise in Graphene Transistors Iddo Heller,,

    E-Print Network [OSTI]

    Dekker, Cees

    Charge Noise in Graphene Transistors Iddo Heller,,§ Sohail Chatoor, Jaan Ma¨nnik, Marcel A. G an experimental study of 1/f noise in liquid-gated graphene transistors. We show that the gate dependence to the graphene, while at high carrier density it is consistent with noise due to scattering in the channel

  17. Automotive friction-induced noises A. Elmaiana

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Automotive friction-induced noises A. Elmaiana , J.-M. Duffala , F. Gautiera , C. Pezeratb and J, France 3143 #12;Friction-induced noises are numerous in the automotive field. They also involve a large friction-induced noises with simple structures and automotive materials. Qualitative sensitivity studies

  18. Data series subtraction with unknown and unmodeled background noise

    E-Print Network [OSTI]

    Stefano Vitale; Giuseppe Congedo; Rita Dolesi; Valerio Ferroni; Mauro Hueller; Daniele Vetrugno; William Joseph Weber; Heather Audley; Karsten Danzmann; Ingo Diepholz; Martin Hewitson; Natalia Korsakova; Luigi Ferraioli; Ferran Gibert; Nikolaos Karnesis; Miquel Nofrarias; Henri Inchauspe; Eric Plagnol; Oliver Jennrich; Paul W. McNamara; Michele Armano; James Ira Thorpe; Peter Wass

    2014-08-04T23:59:59.000Z

    LISA Pathfinder (LPF), ESA's precursor mission to a gravitational wave observatory, will measure the degree to which two test-masses can be put into free-fall, aiming to demonstrate a residual relative acceleration with a power spectral density (PSD) below 30 fm/s$^2$/Hz$^{1/2}$ around 1 mHz. In LPF data analysis, the measured relative acceleration data series must be fit to other various measured time series data. This fitting is required in different experiments, from system identification of the test mass and satellite dynamics to the subtraction of noise contributions from measured known disturbances. In all cases, the background noise, described by the PSD of the fit residuals, is expected to be coloured, requiring that we perform such fits in the frequency domain. This PSD is unknown {\\it a priori}, and a high accuracy estimate of this residual acceleration noise is an essential output of our analysis. In this paper we present a fitting method based on Bayesian parameter estimation with an unknown frequency-dependent background noise. The method uses noise marginalisation in connection with averaged Welch's periodograms to achieve unbiased parameter estimation, together with a consistent, non-parametric estimate of the residual PSD. Additionally, we find that the method is equivalent to some implementations of iteratively re-weighted least-squares fitting. We have tested the method both on simulated data of known PSD, and to analyze differential acceleration from several experiments with the LISA Pathfinder end-to-end mission simulator.

  19. SPEECH ENHANCEMENT IN CAR NOISE ENVIRONMENT BASED ON AN ANALYSIS-SYNTHESIS APPROACH USING HARMONIC NOISE MODEL

    E-Print Network [OSTI]

    So, Hing-Cheung

    SPEECH ENHANCEMENT IN CAR NOISE ENVIRONMENT BASED ON AN ANALYSIS- SYNTHESIS APPROACH USING HARMONIC Kong ABSTRACT This paper presents a speech enhancement method based on an analysis-synthesis framework analysis-synthesis based speech enhancement system, and give details in HNM modeling, parameter estimation

  20. Laser phase noise effects on the dynamics of optomechanical resonators

    E-Print Network [OSTI]

    Gregory A. Phelps; Pierre Meystre

    2010-11-01T23:59:59.000Z

    We investigate theoretically the influence of laser phase noise on the cooling and heating of a generic cavity optomechanical system. We derive the back-action damping and heating rates and the mechanical frequency shift of the radiation pressure-driven oscillating mirror, and derive the minimum phonon occupation number for small laser linewidths. We find that in practice laser phase noise does not pose serious limitations to ground state cooling. We then consider the effects of laser phase noise in a parametric cavity driving scheme that minimizes the back-action heating of one of the quadratures of the mechanical oscillator motion. Laser linewidths narrow compared to the decay rate of the cavity field will not pose any problems in an experimental setting, but broader linewidths limit the practicality of this back-action evasion method.

  1. A computer program for HVDC converter station RF noise calculations

    SciTech Connect (OSTI)

    Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

    1994-04-01T23:59:59.000Z

    HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

  2. Low-noise pulse conditioner

    DOE Patents [OSTI]

    Bird, D.A.

    1981-06-16T23:59:59.000Z

    A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits. This circuit may be used for conditioning the sensor signal from the Fidler coil in a gas centrifuge for separation of isotopic gaseous mixtures.

  3. Low Endogenous Noise in Autism

    E-Print Network [OSTI]

    Davis, Greg; Plaisted-Grant, Kate

    2014-09-24T23:59:59.000Z

    189   that individuals with autism exhibited greater sensitivity for first-order (luminance-190   defined) stimuli yet reduced sensitivity for second-order (contrast-defined) stimuli, 191   relative to neurotypical individuals. Simmons et al... . (2009) argued that both enhanced 192   and impaired sensitivity in the ASD group of study might be explained by increased 193   neural noise in ASD. For first-order stimuli, which are detected at very low 194   luminance-contrasts with relatively...

  4. Noise vs computational intractability in dynamics

    E-Print Network [OSTI]

    Braverman, Mark; Rojas, Cristobal

    2012-01-01T23:59:59.000Z

    Computation plays a key role in predicting and analyzing natural phenomena. There are two fundamental barriers to our ability to computationally understand the long-term behavior of a dynamical system that describes a natural process. The first one is unaccounted-for errors, which may make the system unpredictable beyond a very limited time horizon. This is especially true for chaotic systems, where a small change in the initial conditions may cause a dramatic shift in the trajectories. The second one is Turing-completeness. By the undecidability of the Halting Problem, the long-term prospects of a system that can simulate a Turing Machine cannot be determined computationally. We investigate the interplay between these two forces -- unaccounted-for errors and Turing-completeness. We show that the introduction of even a small amount of noise into a dynamical system is sufficient to "destroy" Turing-completeness, and to make the system's long-term behavior computationally predictable. On a more technical level,...

  5. An SDE approximation for stochastic differential delay equations with colored state-dependent noise

    E-Print Network [OSTI]

    Austin McDaniel; Ozer Duman; Giovanni Volpe; Jan Wehr

    2014-12-09T23:59:59.000Z

    We consider a general multidimensional stochastic differential delay equation (SDDE) with colored state-dependent noises. We approximate it by a stochastic differential equation (SDE) system and calculate its limit as the time delays and the correlation times of the noises go to zero. The main result is proven using a theorem about convergence of stochastic integrals by Kurtz and Protter. It formalizes and extends a result that has been obtained in the analysis of a noisy electrical circuit with delayed state-dependent noise, and may be used as a working SDE approximation of an SDDE modeling a real system, where noises are correlated in time and whose response to noise sources is delayed.

  6. Ion-trap measurements of electric-field noise near surfaces

    E-Print Network [OSTI]

    M. Brownnutt; M. Kumph; P. Rabl; R. Blatt

    2014-09-23T23:59:59.000Z

    Electric-field noise near surfaces is a common problem in diverse areas of physics, and a limiting factor for many precision measurements. There are multiple mechanisms by which such noise is generated, many of which are poorly understood. Laser-cooled, trapped ions provide one of the most sensitive systems to probe electric-field noise at MHz frequencies and over a distance range 30 - 3000 $\\mu$m from the surface. Over recent years numerous experiments have reported spectral densities of electric-field noise inferred from ion heating-rate measurements and several different theoretical explanations for the observed noise characteristics have been proposed. This paper provides an extensive summary and critical review of electric-field noise measurements in ion traps, and compares these experimental findings with known and conjectured mechanisms for the origin of this noise. This reveals that the presence of multiple noise sources, as well as the different scalings added by geometrical considerations, complicate the interpretation of these results. It is thus the purpose of this review to assess which conclusions can be reasonably drawn from the existing data, and which important questions are still open. In so doing it provides a framework for future investigations of surface-noise processes.

  7. The classical nature of nuclear spin noise near clock transitions of Bi donors in silicon

    E-Print Network [OSTI]

    Wen-Long Ma; Gary Wolfowicz; Shu-Shen Li; John J. L. Morton; Ren-Bao Liu

    2015-05-07T23:59:59.000Z

    Whether a quantum bath can be approximated as classical noise is a fundamental issue in central spin decoherence and also of practical importance in designing noise-resilient quantum control. Spin qubits based on bismuth donors in silicon have tunable interactions with nuclear spin baths and are first-order insensitive to magnetic noise at so-called clock-transitions (CTs). This system is therefore ideal for studying the quantum/classical nature of nuclear spin baths since the qubit-bath interaction strength determines the back-action on the baths and hence the adequacy of a classical noise model. We develop a Gaussian noise model with noise correlations determined by quantum calculations and compare the classical noise approximation to the full quantum bath theory. We experimentally test our model through dynamical decoupling sequence of up to 128 pulses, finding good agreement with simulations and measuring electron spin coherence times approaching one second - notably using natural silicon. Our theoretical and experimental study demonstrates that the noise from a nuclear spin bath is analogous to classical Gaussian noise if the back-action of the qubit on the bath is small compared to the internal bath dynamics, as is the case close to CTs. However, far from the CTs, the back-action of the central spin on the bath is such that the quantum model is required to accurately model spin decoherence.

  8. Suppression of Longitudinal Coupled-Bunch Instabilities at the KEK-PF

    SciTech Connect (OSTI)

    Obina, T.; Tobiyama, M.; Honda, T.; Tadano, M.; Flanagan, J.W.; Mitsuhashi, T.; /KEK, Tsukuba; Cheng, W.X.; Fox, J.D.; /SLAC; Teytelman, D.; /Dimtel, Redwood City

    2012-04-09T23:59:59.000Z

    A bunch-by-bunch feedback system has been developed to suppress longitudinal coupled-bunch instabilities at the KEK-PF. A longitudinal kicker based on a DAFNE-type overdamped cavity has been designed and installed in the ring, and a general purpose signal processor, called iGp, has been developed by the collaboration of the KEK, SLAC, and INFN-LNF. The entire feedback loop has been closed by the end of June 2007, and the feedback system has successfully suppressed the longitudinal dipole-mode instabilities up to 430 mA.

  9. Noise Performance Evaluation of the Candidate Digitizers for the MAJORANA DEMONSTRATOR

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao

    2011-03-16T23:59:59.000Z

    The noise performance evaluation of the two digitizer cards being considered for the MAJORANA DEMONSTRATOR (MJD) is presented in this document. The procurement of the data acquisition electronics for the MJD is scheduled to happen this year. At the time of writing this document, there are two candidate digitizer electronic boards. One aspect that is being considered by the collaboration is the feasibility of using the MJD for dark matter searches. The feasibility of using the MJD for this application is going to be dictated by the ability of the demonstrator to reach sub-keV energy resolution. One of the potential sources of noise in the MJD is the data acquisition system. This document will is concluded with a recommendation for the final digitizer board by comparing the noise performance of the two electronics systems. Noise parameters such as the effective number of bits, input range linearity and signal to noise ratio are experimentally determined. The two digitizer cards feature different on-board digital signal processing and these features are compared. The experimental set-up was also used to identify sources of noise. This paper describes these sources of noise in the data acquisition system, along with mitigation strategies. Issues such as grounding and wiring scheme have an impact in the overall data acquisition system performance and are discussed in detail. As a conclusion, the suitability of each one of the cards to become the back bone of the data acquisition system of the MJD is discussed.

  10. Influence of Gaussian white noise on the frequency-dependent first nonlinear polarizability of doped quantum dot

    SciTech Connect (OSTI)

    Ganguly, Jayanta [Department of Chemistry, Brahmankhanda Basapara High School, Basapara, Birbhum 731215, West Bengal (India); Ghosh, Manas, E-mail: pcmg77@rediffmail.com [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India)

    2014-05-07T23:59:59.000Z

    We investigate the profiles of diagonal components of frequency-dependent first nonlinear (?{sub xxx} and ?{sub yyy}) optical response of repulsive impurity doped quantum dots. We have assumed a Gaussian function to represent the dopant impurity potential. This study primarily addresses the role of noise on the polarizability components. We have invoked Gaussian white noise consisting of additive and multiplicative characteristics (in Stratonovich sense). The doped system has been subjected to an oscillating electric field of given intensity, and the frequency-dependent first nonlinear polarizabilities are computed. The noise characteristics are manifested in an interesting way in the nonlinear polarizability components. In case of additive noise, the noise strength remains practically ineffective in influencing the optical responses. The situation completely changes with the replacement of additive noise by its multiplicative analog. The replacement enhances the nonlinear optical response dramatically and also causes their maximization at some typical value of noise strength that depends on oscillation frequency.

  11. A noise inequality for classical forces

    E-Print Network [OSTI]

    Dvir Kafri; J. M. Taylor

    2013-11-18T23:59:59.000Z

    Lorentz invariance requires local interactions, with force laws such as the Coulomb interaction arising via virtual exchange of force carriers such as photons. Many have considered the possibility that, at long distances or large mass scales, this process changes in some way to lead to classical behavior. Here we hypothesize that classical behavior could be due to an inability of some force carriers to convey entanglement, a characteristic measure of nonlocal, quantum behavior. We then prove that there exists a local test that allows one to verify entanglement generation, falsifying our hypothesis. Crucially, we show that noise measurements can directly verify entanglement generation. This provides a step forward for a wide variety of experimental systems where traditional entanglement tests are challenging, including entanglement generation by gravity alone between macroscopic torsional oscillators.

  12. Baseline Suppression of Vehicle Portal Monitor Gamma Count Profiles: A Characterization Study

    SciTech Connect (OSTI)

    Lopresti, Charles A.; Weier, Dennis R.; Kouzes, Richard T.; Schweppe, John E.

    2006-06-15T23:59:59.000Z

    Radiation portal monitor (RPM) systems based upon polyvinyl toluene scintillator (PVT) gamma ray detectors have been deployed to detect illicit trafficking in radioactive materials at border crossings. This report sets forth a characterization of the baseline suppression effect in gross-count gamma ray profiles due to shadow shielding by vehicles entering radiation portal monitors. Shadow shielding is of interest because it reduces the alarm sensitivity of portal monitors. This observational study investigated three types of PVT based commercial RPM systems currently deployed at selected ports of entry in terms of spatial effects relative to detector panel orientation - driver versus passenger side, top versus bottom, and narrow lanes versus wide lanes - as observed for a large number of vehicles. Each portal site appears to have a distinctive baseline suppression signature, based on percent maximum suppression relative to measured background. Results suggest that alarm algorithms based on gross-counts may be further refined through attention to individual site characteristics. In addition, longer vehicle transit times were often correlated with stronger baseline suppression, suggesting that baseline suppression studies should take into account duration (length) of transit. (PIET-43741-TM-333-NIM)

  13. A 24 km fiber-based discretely signaled continuous variable quantum key distribution system

    E-Print Network [OSTI]

    Quyen Dinh Xuan; Zheshen Zhang; Paul L. Voss

    2009-10-06T23:59:59.000Z

    We report a continuous variable key distribution system that achieves a final secure key rate of 3.45 kb/sec over a distance of 24.2 km of optical fiber. The protocol uses discrete signaling and post-selection to improve reconciliation speed and quantifies security by means of quantum state tomography. Polarization multiplexing and a frequency translation scheme permit transmission of a continuous wave local oscillator and suppression of noise from guided acoustic wave Brillouin scattering by more than 27 dB.

  14. Wind Turbine Acoustic Noise A white paper

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Wind Turbine Acoustic Noise A white paper Prepared by the Renewable Energy Research Laboratory...................................................................... 8 Sound from Wind Turbines .............................................................................................. 10 Sources of Wind Turbine Sound

  15. On Powers of Gaussian White Noise

    E-Print Network [OSTI]

    Balakrishnan, A V

    2010-01-01T23:59:59.000Z

    Classical Gaussian white noise in communications and signal processing is viewed as the limit of zero mean second order Gaussian processes with a compactly supported flat spectral density as the support goes to infinity. The difficulty of developing a theory to deal with nonlinear transformations of white noise has been to interpret the corresponding limits. In this paper we show that a renormalization and centering of powers of band-limited Gaussian processes is Gaussian white noise and as a consequence, homogeneous polynomials under suitable renormalization remain white noises.

  16. Highway noise reduction by barrier walls

    E-Print Network [OSTI]

    Young, Murray F

    1971-01-01T23:59:59.000Z

    's Variables 3. Noise Reduction and Noise Reduction Factor 4. Relationship Between Noise Attenuation and d 5. Rettinger's Variables 6. Relationship of Sound-Level Reduction and v 7. Basic Principles in Sound-Transmission Loss 8. The Mass Law Relationship... that the barrier wall is acoustically opaque (i. e. , impermeable to sound waves). Purcell (8) found that the noise transmission loss of a wall was a measure of the ratio of the acoustical energy transmitted through the wall to the acoustical energy incident...

  17. LOCALLY WEIGHTED TOTAL VARIATION DENOISING FOR RINGING ARTIFACT SUPPRESSION IN PET RECONSTRUCTION USING PSF

    E-Print Network [OSTI]

    with PSF modeling is now implemented and widely used in clinical PET/CT systems. Some work has been doneLOCALLY WEIGHTED TOTAL VARIATION DENOISING FOR RINGING ARTIFACT SUPPRESSION IN PET RECONSTRUCTION tomography (PET) images, but also introduces ringing artifacts and over enhancement that is contrast

  18. Harmonics suppression effect of the quasi-periodic undulator in SASE free-electron-laser

    E-Print Network [OSTI]

    Ai-Lin Wu; Qi-Ka Jia; He-Ting Li

    2013-05-03T23:59:59.000Z

    In this paper, the harmonics suppression effect of QPUs in SASE FEL is investigated. The numerical results show that the harmonics power is reduced by using QPUs, but the fundamental radiation power also has a pronounced decrease as the saturation length gets very long. The cases of employing QPUs as parts of undulators are studied. The calculations show that if the fraction of QPUs and their offgap are appropriate in an undulator system, the harmonics radiation could be suppressed remarkably, meanwhile the fundamental saturation length does not increase too much.

  19. Evaluation of noise associated with geothermal-development activities. Final report, July 31, 1979-April 30, 1982

    SciTech Connect (OSTI)

    Long, M.; Stern, R.

    1982-01-01T23:59:59.000Z

    This report was prepared for the purpose of ascertaining the current state of noise generation, suppression, and mitigation techniques associated with geothermal development. A description of the geothermal drilling process is included as well as an overview of geothermal development activities in the United States. Noise sources at the well site, along geothermal pipelines, and at the power plants are considered. All data presented are measured values by workers in the field and by Marshall Long/Acoustics. One particular well site was monitored for a period of 55 continuous days, and includes all sources of noise from the time that the drilling rig was brought in until the time that it was moved off site. A complete log of events associated with the drilling process is correlated with the noise measurements including production testing of the completed well. Data are also presented which compare measured values of geothermal noise with federal, state, county, and local standards. A section on control of geothermal noise is also given. Volume I of this document presents summary information.

  20. Fluctuation-induced noise in out-of-equilibrium disordered superconducting films

    SciTech Connect (OSTI)

    Petkovi?, Aleksandra, E-mail: alpetkovic@gmail.com [Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie and CNRS UMR 7589, 4 place Jussieu, 75005 Paris (France) [Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie and CNRS UMR 7589, 4 place Jussieu, 75005 Paris (France); Laboratoire de Physique Théorique-CNRS, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris (France); Laboratoire de Physique Théorique, IRSAMC, CNRS and Université de Toulouse, UPS, F-31062 Toulouse (France); Vinokur, Valerii M. [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)] [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-12-15T23:59:59.000Z

    We study out-of-equilibrium transport in disordered superconductors close to the superconducting transition. We consider a thin film connected by resistive tunnel interfaces to thermal reservoirs having different chemical potentials and temperatures. The nonequilibrium longitudinal current–current correlation function is calculated within the nonlinear sigma model description and nonlinear dependence on temperatures and chemical potentials is obtained. Different contributions are calculated, originating from the fluctuation-induced suppression of the quasiparticle density of states, Maki–Thompson and Aslamazov–Larkin processes. As a special case of our results, close-to-equilibrium we obtain the longitudinal ac conductivity using the fluctuation–dissipation theorem. -- Highlights: •Contributions to the current noise induced by superconducting fluctuations are calculated. •Nonequilibrium physics is studied. •Nonlinear dependence of the noise on temperatures and chemical potentials of the reservoirs is found.

  1. Metasurfaces for suppressing reflection over broadband

    E-Print Network [OSTI]

    Patra, Anuradha; Nagarajan, Arvind; Achanta, Venu Gopal

    2015-01-01T23:59:59.000Z

    Surfaces patterned with arrays of quasi-periodic air holes having conical depth profile have been studied for their effectiveness in suppressing air-substrate reflection in the wavelength range of 450-1350 nm (limited by our measurement). The role of quasi-periodic air-hole pattern, depth of holes and launch angle on the observed antireflection behavior are investigated. The average optical transmittance of the patterned quartz substrate at near normal incidence is more than 97% and reflectance is less than 2%. Patterned quartz surfaces with 450 nm thin graded rarefaction region maintain the antireflective property up to 30{\\deg} (limited by our measurements) angle of incidence.

  2. Why the nature needs 1/f-noise

    E-Print Network [OSTI]

    Kuzovlev, Yu E

    2015-01-01T23:59:59.000Z

    Low-frequency 1/f-noise occurs at all levels of the nature organization and became an actual factor of nanotechnologies, but in essence it remains misunderstood by its investigators. Here, once again it is pointed out that such the state of affairs may be caused by uncritical application of probability theory notions to physical random phenomena, first of all the notion of "independence". It is shown that in the framework of statistical mechanics no medium could provide an inner wandering particle with quite certain value of diffusivity and mobility, thereby producing flicker fluctuations of these quantities. This is example of realization of universal 1/f-noise origin in many-particle systems: dependence of time progress of any particular relaxation or transport process on the whole system's detailed initial microstate

  3. Effects of finite sampling and additive noise on image reconstruction from Radon transform

    SciTech Connect (OSTI)

    Tsujimoto, E.M. (California Univ., Davis, CA (USA))

    1988-12-01T23:59:59.000Z

    The Radon transform arises naturally in the problem of reconstructing an image or cross section from line integral measurements through a specified object. Each line integral or ray is a sample of the Radon transform of the object and the set of all samples at a particular angle is called a projection or view. Consequently, the set of all possible samples at all possible projections in a particular plane constitutes the two-dimensional Radon transform. Of course, it is impossible to acquire an infinite number of data points for the purpose of image reconstruction. However, with a sufficient set of Radon transform samples, an images can be determined through various Radon transform inversion techniques. From this statement, however, arises the question of just what constitutes a sufficient set of Radon transform samples. Acquiring an insufficient number of samples results in various artifacts in the reconstructed image. On the other hand, taking too many samples utilizes the data inefficiently. Thus, the problem of interest is to determine the optimum number of projections and the optimum number of samples per projection required to adequately represent the Radon transform such that the image can be accurately reconstructed. The problem of image reconstruction is further complicated if noise is introduced in the projection domain. Noise may be caused by round-off error in the sampled projection data or by various other factors inherent in data acquisition processes. However, several filtering techniques can be implemented to suppress the effects of noise. Therefore, a second problem of interest is to study the effectiveness of different filtering techniques in noise suppression.

  4. SSSSSSSS LLLLSemiconductor System LabSemiconductor System LabSemiconductor System LabSemiconductor System Lab Jaeseo Lee, Gigabit Optical Interface IC Design 1

    E-Print Network [OSTI]

    Yoo, Hoi-Jun

    range Wide Bandwidth Low Noise amplifier is required!! 60~80dB 1) providing dc level restoration 2Semiconductor System Lab Design Goal · Gain range : 60~80dB (1k ~ 10k) · Wide bandwidth · Low Noise · CMOS · Motivation · Transimpedance Amplifier (TIA) ­ Why TIA? ­ Noise Source ­ TIA Noise & Design Solution

  5. Fighting dephasing noise with robust optimal control

    E-Print Network [OSTI]

    Kevin C. Young; Dylan J Gorman; K. Birgitta Whaley

    2010-05-28T23:59:59.000Z

    We address the experimentally relevant problem of robust mitigation of dephasing noise acting on a qubit. We first present an extension of a method for representing $1/\\omega^{\\alpha}$ noise developed by Kuopanportti et al. to the efficient representation of arbitrary Markovian noise. We then add qubit control pulses to enable the design of numerically optimized, two-dimensional control functions with bounded amplitude, that are capable of decoupling the qubit from the dephasing effects of a broad variety of Markovian noise spectral densities during arbitrary one qubit quantum operations. We illustrate the method with development of numerically optimized control pulse sequences that minimize decoherence due to a combination of $1/\\omega$ and constant offset noise sources. Comparison with the performance of standard dynamical decoupling protocols shows that the numerically optimized pulse sequences are considerably more robust with respect to the noise offset, rendering them attractive for application to situations where homogeneous dephasing noise sources are accompanied by some extent of heterogeneous dephasing. Application to the mitigation of dephasing noise on spin qubits in silicon indicates that high fidelity single qubit gates are possible with current pulse generation technology.

  6. Atmospheric Noise in Single Dish Observations

    E-Print Network [OSTI]

    Militzer, Burkhard

    the errors in a wideband total power measurement. Noise con­ tributions come from thermal noise consider total power measurements with a single dish radiometer. The measured total power, p[K] = g \\Theta for extended sources. For wideband total power observations, the maximum integration time ¸ 0.1 s in order

  7. Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling

    E-Print Network [OSTI]

    André Thüring; Christian Gräf; Henning Vahlbruch; Moritz Mehmet; Karsten Danzmann; Roman Schnabel

    2010-05-25T23:59:59.000Z

    Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically coupled cavities and efficiently enhances the sensitivity of an interferometer at a dedicated signal frequency. We report on the first experimental realization of a Twin-Signal-Recycling Michelson interferometer and also its broadband enhancement by squeezed light injection. The complete setup was stably locked and a broadband quantum noise reduction of the interferometers shot noise by a factor of up to 4\\,dB was demonstrated. The system was characterized by measuring its quantum noise spectra for several tunings of the TSR cavities. We found good agreement between the experimental results and numerical simulations.

  8. Leading the way in aircraft noise reduction Aircraft noise threatens the growth of the important UK aerospace manufacturing sector.

    E-Print Network [OSTI]

    Sóbester, András

    of Computational Aero-acoustics, Phil Joseph, Professor of acoustical engineering and turbo-machinery noise and Dr method for reducing fan noise, the largest single source of engine noise both at take-off and approachLeading the way in aircraft noise reduction Aircraft noise threatens the growth of the important UK

  9. Ultrasensitive measurement of MEMS cantilever displacement sensitivity below the shot noise limit

    E-Print Network [OSTI]

    R. C. Pooser; B. J. Lawrie

    2015-04-04T23:59:59.000Z

    The displacement of micro-electro-mechanical-systems (MEMS) cantilevers is used to measure a broad variety of phenomena in devices ranging from force microscopes to biochemical sensors to thermal imaging systems. We demonstrate the first direct measurement of a MEMS cantilever displacement with a noise floor at 40% of the shot noise limit (SNL). By combining multi-spatial-mode quantum light sources with a simple ?differential measurement, we show that sub-SNL MEMS displacement sensitivity is highly accessible compared to previous efforts that measured the displacement of macroscopic mirrors with very distinct spatial structures crafted with multiple optical parametric amplifiers and locking loops. These results support a new class of quantum MEMS sensor with an ultimate signal to noise ratio determined by quantum correlations, enabling ultra-trace sensing, imaging, and microscopy applications in which signals were previously obscured by shot noise.

  10. The efficiency of environmental impact assessments relating to noise issues

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    The efficiency of environmental impact assessments relating to noise issues Z. Krukle University of environmental impact assessments (EIA) relating to noise issues. The goal is attained through evaluation, effectiveness, environmental impact assessment, noise 1 Introduction Environmental impact assessment (EIA

  11. Suppression of Magnetic State Decoherence Using Ultrafast Optical Pulses

    E-Print Network [OSTI]

    C. Search; P. R. Berman

    2000-03-01T23:59:59.000Z

    It is shown that the magnetic state decoherence produced by collisions in a thermal vapor can be suppressed by the application of a train of ultrafast optical pulses.

  12. acids suppresses diethylnitrosamine-induced: Topics by E-print...

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

    Topic Index 1 Suppression of rice methane emission by sulfate deposition in simulated acid rain Geosciences Websites Summary: from rice agriculture. Emissions from rice plants...

  13. acid suppression therapy: Topics by E-print Network

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

    2006-01-01 2 Suppression of rice methane emission by sulfate deposition in simulated acid rain Geosciences Websites Summary: from rice agriculture. Emissions from rice plants...

  14. acid suppression trial: Topics by E-print Network

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

    1997-01-01 2 Suppression of rice methane emission by sulfate deposition in simulated acid rain Geosciences Websites Summary: from rice agriculture. Emissions from rice plants...

  15. acid suppression predict: Topics by E-print Network

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

    Davis, Matt 2 Suppression of rice methane emission by sulfate deposition in simulated acid rain Geosciences Websites Summary: from rice agriculture. Emissions from rice plants...

  16. Suppressive effects of ketamine on macrophage functions

    SciTech Connect (OSTI)

    Chang Yi [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Chen, T.-L. [Department of Anesthesiology, Wan-Fang Hospital, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Sheu, J.-R. [Department of Anesthesiology, Wan-Fang Hospital, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Chen, R.-M. [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China) and Department of Anesthesiology, Wan-Fang Hospital, College of Medicine, Taipei Medical University, Taipei, Taiwan (China)]. E-mail: rmchen@tmu.edu.tw

    2005-04-01T23:59:59.000Z

    Ketamine is an intravenous anesthetic agent. Clinically, induction of anesthesia with ketamine can cause immunosuppression. Macrophages play important roles in host defense. In this study, we attempted to evaluate the effects of ketamine on macrophage functions and its possible mechanism using mouse macrophage-like Raw 264.7 cells as the experimental model. Exposure of macrophages to 10 and 100 {mu}M ketamine, which correspond to 0.1 and 1 times the clinically relevant concentration, for 1, 6, and 24 h had no effect on cell viability or lactate dehydrogenase release. When the administered concentration reached 1000 {mu}M, ketamine caused a release of lactate dehydrogenase and cell death. Ketamine, at 10 and 100 {mu}M, did not affect the chemotactic activity of macrophages. Administration of 1000 {mu}M ketamine in macrophages resulted in a decrease in cell migration. Treatment of macrophages with ketamine reduced phagocytic activities. The oxidative ability of macrophages was suppressed by ketamine. Treatment with lipopolysaccharide induced TNF-{alpha}, IL-1{beta}, and IL-6 mRNA in macrophages. Administration of ketamine alone did not influence TNF-{alpha}, IL-1{beta}, or IL-6 mRNA production. Meanwhile, cotreatment with ketamine and lipopolysaccharide significantly inhibited lipopolysaccharide-induced TNF-{alpha}, IL-1{beta}, and IL-6 mRNA levels. Exposure to ketamine led to a decrease in the mitochondrial membrane potential. However, the activity of mitochondrial complex I NADH dehydrogenase was not affected by ketamine. This study shows that a clinically relevant concentration of ketamine (100 {mu}M) can suppress macrophage function of phagocytosis, its oxidative ability, and inflammatory cytokine production possibly via reduction of the mitochondrial membrane potential instead of direct cellular toxicity.

  17. Noise-based communication and computing

    E-Print Network [OSTI]

    Laszlo B. Kish

    2008-08-19T23:59:59.000Z

    We discuss the speed-error-heat triangle and related problems with rapidly increasing energy dissipation and error rate during miniaturization. These and the independently growing need of unconditional data security have provoked non-conventional approaches in the physics of informatics. Noise-based informatics is a potentially promising possibility which is the way how biological brains process the information. Recently, it has been shown that thermal noise and its electronically enhanced versions (Johnson-like noises) can be utilized as information carrier with peculiar properties. Relevant examples are Zero power (stealth) communication, Unconditionally secure communication with Johnson(-like) noise and Kirchhoff loop and Noise-driven computing. The zero power communication utilizes the equilibrium background noise in the channel to transfer information. The unconditionally secure communication is based on the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The scheme utilizes on the robustness of classical information and the second law of thermodynamics. It uncovers active eavesdropping within a single clock period (no error statistics is required) and it is naturally protected against the man-in-the-middle attack. Further advantages of the scheme is that the circuitry can easily be integrated on computer chips, unconditionally secure computer processors, memories and other hardware can be realized.

  18. acoustic background noise: Topics by E-print Network

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

    or remove acoustic background noise uses setups Paris-Sud XI, Universit de 3 Wind Turbine Acoustic Noise A white paper Renewable Energy Websites Summary: Wind Turbine...

  19. airborne noise emitted: Topics by E-print Network

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

    The light intensity noise was measured as a function of wavelength within the light emitting diode spectral emission line. The spectral noise density is found to increase Wetzel,...

  20. Integration of Noise and Coda Correlation Data into Kinematic...

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

    noise correlation Green's functions (NCF) obtained from MEQs and ambient noise and coda-wave interferometry to image the physical properties of geothermal reservoirs and detect and...

  1. aircraft noise exposure: Topics by E-print Network

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

    paths minimizing aircraft noise d'Orlans, Universit 2 The cost of noise reduction in commercial tilt rotor aircraft MIT - DSpace Summary: The relationship between...

  2. aircraft engine noise: Topics by E-print Network

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

    paths minimizing aircraft noise d'Orlans, Universit 2 The cost of noise reduction in commercial tilt rotor aircraft MIT - DSpace Summary: The relationship between...

  3. Thermophoresis of Brownian particles driven by coloured noise

    E-Print Network [OSTI]

    Hottovy, Scott; Wehr, Jan

    2012-01-01T23:59:59.000Z

    The Brownian motion of microscopic particles is driven by the collisions with the molecules of the surrounding fluid. The noise associated with these collisions is not white, but coloured due, e.g., to the presence of hydrodynamic memory. The noise characteristic time scale is typically of the same order as the time over which the particle's kinetic energy is lost due to friction (inertial time scale). We demonstrate theoretically that, in the presence of a temperature gradient, the interplay between these two characteristic time scales can have measurable consequences on the particle long-time behaviour. Using homogenization theory, we analyse the infinitesimal generator of the stochastic differential equation describing the system in the limit where the two characteristic times are taken to zero; from this generator, we derive the thermophoretic transport coefficient, which, we find, can vary in both magnitude and sign, as observed in experiments. Furthermore, studying the long-term stationary particle dist...

  4. Semiclassical theory of noise in multielement semiconductor lasers

    SciTech Connect (OSTI)

    Lang, R.J.; Yariv, A.

    1986-03-01T23:59:59.000Z

    The authors present a derivation of the noise spectra of multielement semiconductor lasers. They model the noise by a set of Langevin sources which drive a system of small-signal field equations. The Langevin sources are normalized to transition rates within the laser and general formulas for relative intensity, frequency fluctuation, and field spectra are produced. They evaluate the formulas for several specific cases of interest, including those of a passive-active resonator and active-active coupled cavity resonator. In each case, the linewidth is governed by effective ..cap alpha..-parameter(s) which generally differ from the material parameter. In the active-active cavity, the linewidth consists of two parts, one which is similar to the Schawlow-Townes linewidth, and a second which is proportional to the FM modulation index.

  5. Effects of Tidal Turbine Noise on Fish Task 2.1.3.2: Effects on Aquatic Organisms: Acoustics/Noise - Fiscal Year 2011 - Progress Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect (OSTI)

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30T23:59:59.000Z

    Naturally spawning stocks of Chinook salmon (Oncorhynchus tshawytscha) that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/ Chinook/CKPUG.cfm). Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study (Effects on Aquatic Organisms, Subtask 2.1.3.2: Acoustics) was performed during FY 2011 to determine if noise generated by a 6-m-diameter open-hydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Preliminary results indicate that low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

  6. Estimating atmospheric parameters and reducing noise for multispectral imaging

    DOE Patents [OSTI]

    Conger, James Lynn

    2014-02-25T23:59:59.000Z

    A method and system for estimating atmospheric radiance and transmittance. An atmospheric estimation system is divided into a first phase and a second phase. The first phase inputs an observed multispectral image and an initial estimate of the atmospheric radiance and transmittance for each spectral band and calculates the atmospheric radiance and transmittance for each spectral band, which can be used to generate a "corrected" multispectral image that is an estimate of the surface multispectral image. The second phase inputs the observed multispectral image and the surface multispectral image that was generated by the first phase and removes noise from the surface multispectral image by smoothing out change in average deviations of temperatures.

  7. Regression of Environmental Noise in LIGO Data

    E-Print Network [OSTI]

    Tiwari, Vaibhav; Frolov, Valery; Klimenko, Sergey; Mitselmakher, Guenakh; Necula, Valentin; Prodi, Giovanni; Re, Virginia; Salemi, Francesco; Vedovato, Gabriele; Yakushin, Igor

    2015-01-01T23:59:59.000Z

    We address the problem of noise regression in the output of gravitational-wave (GW) interferometers, using data from the physical environmental monitors (PEM). The objective of the regression analysis is to predict environmental noise in the gravitational-wave channel from the PEM measurements. One of the most promising regression method is based on the construction of Wiener-Kolmogorov filters. Using this method, the seismic noise cancellation from the LIGO GW channel has already been performed. In the presented approach the Wiener-Kolmogorov method has been extended, incorporating banks of Wiener filters in the time-frequency domain, multi-channel analysis and regulation schemes, which greatly enhance the versatility of the regression analysis. Also we presents the first results on regression of the bi-coherent noise in the LIGO data.

  8. Regression of Environmental Noise in LIGO Data

    E-Print Network [OSTI]

    Vaibhav Tiwari; Marco Drago; Valery Frolov; Sergey Klimenko; Guenakh Mitselmakher; Valentin Necula; Giovanni Prodi; Virginia Re; Francesco Salemi; Gabriele Vedovato; Igor Yakushin

    2015-03-25T23:59:59.000Z

    We address the problem of noise regression in the output of gravitational-wave (GW) interferometers, using data from the physical environmental monitors (PEM). The objective of the regression analysis is to predict environmental noise in the gravitational-wave channel from the PEM measurements. One of the most promising regression method is based on the construction of Wiener-Kolmogorov filters. Using this method, the seismic noise cancellation from the LIGO GW channel has already been performed. In the presented approach the Wiener-Kolmogorov method has been extended, incorporating banks of Wiener filters in the time-frequency domain, multi-channel analysis and regulation schemes, which greatly enhance the versatility of the regression analysis. Also we presents the first results on regression of the bi-coherent noise in the LIGO data.

  9. Noise and synamics in semiconductor lasers

    E-Print Network [OSTI]

    Rana, Farhan, 1971-

    2003-01-01T23:59:59.000Z

    In this thesis, theoretical and experimental work on the noise and dynamics in continuous wave and mode-locked semiconductor lasers is presented. The main focus is on semiconductor cascade lasers and semiconductor mode-locked ...

  10. Speculative Execution Exception Recovery Write-back Suppression

    E-Print Network [OSTI]

    Mahlke, Scott A.

    Speculative Execution Exception Recovery using Write-back Suppression Roger A. Bringmann Scott A or extra register pressure. This paper introduces a new architecture scheme referred to as write-back that with a modest amount of hardware, write- back suppression supports accurate reporting and handling of exceptions

  11. Dissipation, noise and DCC domain formation

    E-Print Network [OSTI]

    A. K. Chaudhuri

    1999-08-17T23:59:59.000Z

    We investigate the effect of friction on domain formation in disoriented chiral condensate. We solve the equation of motion of the linear sigma model, in the Hartree approximation, including a friction and a white noise term. For quenched initial condition, we find that even in presence of noise and dissipation domain like structure emerges after a few fermi of evolution. Domain size as large as 5 fm can be formed.

  12. Effect of noise on the standard mapping

    SciTech Connect (OSTI)

    Karney, C.F.F.; Rechester, A.B.; White, R.B.

    1981-03-01T23:59:59.000Z

    The effect of a small amount of noise on the standard mapping is considered. Whenever the standard mapping possesses accelerator models (where the action increases approximately linearly with time), the diffusion coefficient contains a term proportional to the reciprocal of the variance of the noise term. At large values of the stochasticity parameter, the accelerator modes exhibit a universal behavior. As a result the dependence of the diffusion coefficient on stochasticity parameter also shows some universal behavior.

  13. Excess optical quantum noise in atomic sensors

    E-Print Network [OSTI]

    Irina Novikova; Eugeniy E. Mikhailov; Yanhong Xiao

    2014-10-14T23:59:59.000Z

    Enhanced nonlinear optical response of a coherent atomic medium is the basis for many atomic sensors, and their performance is ultimately limited by the quantum fluctuations of the optical read-out. Here we demonstrate that off-resonant interactions can significantly modify the quantum noise of the optical field, even when their effect on the mean signal is negligible. We illustrate this concept by using an atomic magnetometer based on the nonlinear Faraday effect: the rotation of the light polarization is mainly determined by the resonant light-induced spin alignment, which alone does not change the photon statistics of the optical probe. Yet, we found that the minimum noise of output polarization rotation measurements is above the expected shot noise limit. This excess quantum noise is due to off-resonant coupling and grows with atomic density. We also show that the detection scheme can be modified to reduce the measured quantum noise (even below the shot-noise limit) but only at the expense of the reduced rotational sensitivity. These results show the existence of previously unnoticed factors in fundamental limitations in atomic magnetometry and could have impacts in many other atom-light based precision measurements.

  14. Quantum-projection-noise-limited interferometry with coherent atoms in a Ramsey-type setup

    SciTech Connect (OSTI)

    Doering, D.; McDonald, G.; Debs, J. E.; Figl, C.; Altin, P. A.; Bachor, H.-A.; Robins, N. P.; Close, J. D. [Australian Research Council Centre of Excellence for Quantum-Atom Optics, Australian National University, Canberra, 0200 (Australia); Department of Quantum Science, Research School of Physics and Engineering, Australian National University, Canberra, 0200 (Australia)

    2010-04-15T23:59:59.000Z

    Every measurement of the population in an uncorrelated ensemble of two-level systems is limited by what is known as the quantum projection noise limit. Here, we present quantum-projection-noise-limited performance of a Ramsey-type interferometer using freely propagating coherent atoms. The experimental setup is based on an electro-optic modulator in an inherently stable Sagnac interferometer, optically coupling the two interfering atomic states via a two-photon Raman transition. Going beyond the quantum projection noise limit requires the use of reduced quantum uncertainty (squeezed) states. The experiment described demonstrates atom interferometry at the fundamental noise level and allows the observation of possible squeezing effects in an atom laser, potentially leading to improved sensitivity in atom interferometers.

  15. Performance analysis of interference suppression techniques for multiple antenna systems

    E-Print Network [OSTI]

    Amihood, Patrick

    2007-01-01T23:59:59.000Z

    Pre-BLAST-DFE Technique for MISO Channels with DecentralizedPrecoding Operating over MISO Frequency Selec- tive Fadingon a Nonlinear Precoder for MISO Channels with Decentralized

  16. Ambient habitat noise and vibration at the Georgia Aquarium

    E-Print Network [OSTI]

    Johnson, Michael T.

    Ambient habitat noise and vibration at the Georgia Aquarium P. M. Scheifele Department significant levels of background noise due to pumps and motors. This noise, together with pool architecture to quantify the ambient noise levels in the water from machine vibration and from in-air performance speaker

  17. Empirical Study of Noise Dependence in Electrochemical Sensors

    E-Print Network [OSTI]

    Candea, George

    is temperature and frequency independent, in contrast to thermal noise, which is proportional to temperature, is a process with a frequency spectrum such that the power spectral density of the noise is proportional the effect of concentration and voltage on the noise Power Spectral Density (PSD) and the Signal over Noise

  18. Reversible electron beam heating for suppression of microbunching instabilities at free-electron lasers

    E-Print Network [OSTI]

    Behrens, Christopher; Xiang, Dao

    2011-01-01T23:59:59.000Z

    The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future X-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., "heating" the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) in front and behind a magnetic bunch compressor chicane. The additional energy spread will be introduced in the first TDS, which suppresses the microbunching instability, and then will be eliminated in the second T...

  19. Interferometric at-wavelength flare characterization of EUV optical systems

    DOE Patents [OSTI]

    Naulleau, Patrick P. (Oakland, CA); Goldberg, Kenneth Alan (Berkeley, CA)

    2001-01-01T23:59:59.000Z

    The extreme ultraviolet (EUV) phase-shifting point diffraction interferometer (PS/PDI) provides the high-accuracy wavefront characterization critical to the development of EUV lithography systems. Enhancing the implementation of the PS/PDI can significantly extend its spatial-frequency measurement bandwidth. The enhanced PS/PDI is capable of simultaneously characterizing both wavefront and flare. The enhanced technique employs a hybrid spatial/temporal-domain point diffraction interferometer (referred to as the dual-domain PS/PDI) that is capable of suppressing the scattered-reference-light noise that hinders the conventional PS/PDI. Using the dual-domain technique in combination with a flare-measurement-optimized mask and an iterative calculation process for removing flare contribution caused by higher order grating diffraction terms, the enhanced PS/PDI can be used to simultaneously measure both figure and flare in optical systems.

  20. Quantum Noise Interference and Backaction Cooling in Cavity Nanomechanics Florian Elste,1

    E-Print Network [OSTI]

    Clerk, Aashish

    , progress has also been motivated by the realiza- tion that such systems are ideally poised to allow in these systems is the ability to cool the mechanical resona- tor to near its ground state. A particularlyQuantum Noise Interference and Backaction Cooling in Cavity Nanomechanics Florian Elste,1 S. M

  1. On Filtering the Noise from the Random Parameters in Monte Carlo Rendering

    E-Print Network [OSTI]

    Sen, Pradeep

    On Filtering the Noise from the Random Parameters in Monte Carlo Rendering PRADEEP SEN and SOHEIL DARABI UNM Advanced Graphics Lab Monte Carlo (MC) rendering systems can produce spectacular images from a small number of input samples. To do this, we treat the rendering system as a black box

  2. Some properties of zero power neutron noise in a time-varying medium with delayed neutrons

    E-Print Network [OSTI]

    Pázsit, Imre

    material parameters was treated with the master equation technique, which is a probability balance equation and discussed. Ã? 2008 Elsevier Ltd. All rights reserved. 1. Introduction In the neutron noise literature power systems constituted a separate case. In such systems the material parameters, and hence also

  3. IMPROVING INTELLIGIBILITY IN NOISE OF HMM-GENERATED SPEECH VIA NOISE-DEPENDENT AND -INDEPENDENT METHODS

    E-Print Network [OSTI]

    Edinburgh, University of

    the intelligibility of HMM-generated Text-to- Speech (TTS) in noise, this work evaluates several speech enhance- ment in noise. Accordingly, there is great interest in speech in- telligibility enhancement algorithms for both] and the insertion of small pauses [14]. Statistical approaches to speech enhancement using recordings of speech

  4. Reliability of electrochemical noise measurements: results of round-robin testing on electrochemical noise

    E-Print Network [OSTI]

    1 Reliability of electrochemical noise measurements: results of round-robin testing" arrangement of resistors in order to validate the EN measurement equipment and determine its baseline noise because of the absence of anti-aliasing filters in the equipment or because the way it is used

  5. Diversity in ambient noise in European freshwater habitats: Noise levels, spectral profiles, and impact on fishes

    E-Print Network [OSTI]

    Ladich, Friedrich

    23 January 2007; accepted 3 February 2007 The detectability of acoustic signals dependsB re 1 Pa LLeq under no-wind conditions. Typically, most environmental noise is concentrated of sound energy were present in the high frequency range above 1 kHz, leaving a low-energy "noise window

  6. Superconducting quantum interference devices based set-up for probing current noise and correlations in three-terminal devices

    SciTech Connect (OSTI)

    Pfeffer, A. H.; Kaviraj, B.; Coupiac, O.; Lefloch, F. [SPSMS/LaTEQS, UMR-E 9001, CEA-INAC, and Universite Joseph Fourier, Grenoble (France)

    2012-11-15T23:59:59.000Z

    We have implemented a new experimental set-up for precise measurements of current fluctuations in three-terminal devices. The system operates at very low temperatures (30 mK) and is equipped with three superconducting quantum interference devices (SQUIDs) as low noise current amplifiers. A SQUID input coil is connected to each terminal of a sample allowing the acquisition of time-dependent current everywhere in the circuit. From these traces, we can measure the current mean value, the noise, and cross-correlations between different branches of a device. In this paper, we present calibration results of noise and cross-correlations obtained using low impedance macroscopic resistors. From these results, we can extract the noise level of the set-up and show that there are no intrinsic correlations due to the measurement scheme. We also studied noise and correlations as a function of a dc current and estimated the electronic temperature of various macroscopic resistors.

  7. antigens suppresses murine: Topics by E-print Network

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

    in adulthood of autoreactive T cells specific to that antigen. The renal-specific ... Marshall, Naomi Jane 2009-01-01 17 Thymosin Beta 4 has tumor suppressive effects and its...

  8. Nuclear Suppression of Dileptons at Large xF

    E-Print Network [OSTI]

    J. Cepila; J. Nemchik

    2009-10-09T23:59:59.000Z

    We study a significant nuclear suppression of the relative production rates (p(d)+A)/(p+d(p)) for the Drell-Yan process at large Feynman xF. Since this is the region of minimal values for the light-front momentum fraction variable x2 in the target nucleus, it is tempting to interpret this as a manifestation of coherence or of a Color Glass Condensate. We demonstrate, however, that this suppression mechanism is governed by the energy conservation restrictions in multiple parton rescatterings in nuclear matter. To eliminate nuclear shadowing effects coming from the coherence, we calculate nuclear suppression in the light-cone dipole approach at large dilepton masses and at energy accessible at FNAL. Our calculations are in a good agreement with data from the E772 experiment. Using the same mechanism we predict also nuclear suppression at forward rapidities in the RHIC energy range.

  9. Global microRNA depletion suppresses tumor angiogenesis

    E-Print Network [OSTI]

    Chen, Sidi

    MicroRNAs delicately regulate the balance of angiogenesis. Here we show that depletion of all microRNAs suppresses tumor angiogenesis. We generated microRNA-deficient tumors by knocking out Dicer1. These tumors are highly ...

  10. Suppression of Dilepton Production in Hot Hadronic Matter

    E-Print Network [OSTI]

    Song, C.; Lee, S. H.; Ko, Che Ming.

    1995-01-01T23:59:59.000Z

    -meson resonance is suppressed as a result of the modification of the pion electromagnetic form factor at finite temperature. The relevance of this phenomenon to the partial restoration of chiral symmetry in hot hadronic matter is discussed....

  11. Causal Baryon Diffusion and Colored Noise

    E-Print Network [OSTI]

    J. I. Kapusta; C. Young

    2014-04-18T23:59:59.000Z

    We construct a model of baryon diffusion which has the desired properties of causality and analyticity. The model also has the desired property of colored noise, meaning that the noise correlation function is not a Dirac delta function in space and time; rather, it depends on multiple time and length constants. The model can readily be incorporated in 3+1 dimensional second order viscous hydro-dynamical models of heavy ion collisions, which is particularly important at beam energies where the baryon density is large.

  12. Turbulence ingestion noise of open rotors

    E-Print Network [OSTI]

    Robison, Rosalyn Aruna Venner

    2012-04-10T23:59:59.000Z

    . Thus a blade whose leading edge curves back in the axial direction, as seen in Figure 1.4, has non-zero sweep. 1.2 Technological context: the open rotor design 9 Figure 1.3: Example of Rig 140 noise results. Image reproduced with permission from... , flight testing and calibration of methods. Hoff included a diagram which illustrated the many different propfan noise sources, see Figure 1.4. There was also a recognition that distortion is an important factor in predicting the acoustics of propeller...

  13. Amplitude modulation of wind turbine noise

    E-Print Network [OSTI]

    Makarewicz, Rufin

    2013-01-01T23:59:59.000Z

    Due to swish and thump amplitude modulation, the noise of wind turbines cause more annoyance than other environmental noise of the same average level. The wind shear accounts for the thump modulation (van den Berg effect). Making use of the wind speed measurements at the hub height, as well as at the top and the bottom of the rotor disc (Fig.1), the non-standard wind profile is applied. It causes variations in the A-weighted sound pressure level, LpA. The difference between the maximum and minimum of LpA characterizes thump modulation (Fig.2).

  14. Climate Dependency of Tree Growth Suppressed by Acid Deposition

    E-Print Network [OSTI]

    Lapenas, Andrei G.

    uptake). These soil changes coincided with decreased diameter growth and a suppression of climateClimate Dependency of Tree Growth Suppressed by Acid Deposition Effects on Soils in Northwest Russia G R E G O R Y B . L A W R E N C E , * , A N D R E I G . L A P E N I S , D A N B E R G G R E N

  15. Geometric phase of a qubit driven by a phase noise laser under non-Markovian dynamics

    SciTech Connect (OSTI)

    Berrada, K., E-mail: kberrada@ictp.it

    2014-01-15T23:59:59.000Z

    Robustness of the geometric phase (GP) with respect to the environmental effects is a basic condition for an effective quantum computation. Here, we study quantitatively the GP of a two-level atom system driven by a phase noise laser under non-Markovian dynamics in terms of different parameters involved in the whole system. We find that with the change of the damping coupling, the GP is very sensitive to its properties exhibiting long collapse and revival phenomena, which play a significant role in enhancing the stabilization and control of the system dynamics. Moreover, we show that the GP can be considered as a tool for testing and characterizing the nature of the qubit–environment coupling. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement dynamics between the qubit with its environment under external classical noise is evaluated and investigated during the time evolution. -- Highlights: •Geometric phase under noise phase laser. •Dynamics of the geometric phase under non-Markovian dynamics in the presence of classical noise. •Solution of master equation of the system in terms atomic inversion. •Nonlocal correlation between the system and its environment under non-Markovianity.

  16. Acoustic Array Development for Wind Turbine Noise Characterization

    SciTech Connect (OSTI)

    Buck, S.; Roadman, J.; Moriarty, P.; Palo, S.

    2013-11-01T23:59:59.000Z

    This report discusses the design and use of a multi-arm, logarithmic spiral acoustic array by the National Renewable Energy Laboratory (NREL) for measurement and characterization of wind turbine-generated noise. The array was developed in collaboration with a team from the University of Colorado Boulder. This design process is a continuation of the elliptical array design work done by Simley. A description of the array system design process is presented, including array shape design, mechanical design, design of electronics and the data acquisition system, and development of post-processing software. System testing and calibration methods are detailed. Results from the initial data acquisition campaign are offered and discussed. Issues faced during this initial deployment of the array are presented and potential remedies discussed.

  17. NONLINEAR EFFECTS OF A MODAL DOMAIN OPTICAL FIBER SENSOR IN A VIBRATION SUPPRESSION CONTROL LOOP FOR A FLEXIBLE

    E-Print Network [OSTI]

    Lindner, Douglas K.

    NONLINEAR EFFECTS OF A MODAL DOMAIN OPTICAL FIBER SENSOR IN A VIBRATION SUPPRESSION CONTROL LOOP Recently, a modal domain optical fiber sensor has been demonstrated as a sensor in a control system the region of linear operation in terms of the optical fiber sensor parameters. #12;2 1. INTRODUCTION

  18. Dimensionality and noise in energy selective x-ray imaging

    SciTech Connect (OSTI)

    Alvarez, Robert E. [Aprend Technology, Mountain View, California 94043 (United States)] [Aprend Technology, Mountain View, California 94043 (United States)

    2013-11-15T23:59:59.000Z

    Purpose: To develop and test a method to quantify the effect of dimensionality on the noise in energy selective x-ray imaging.Methods: The Cramèr-Rao lower bound (CRLB), a universal lower limit of the covariance of any unbiased estimator, is used to quantify the noise. It is shown that increasing dimensionality always increases, or at best leaves the same, the variance. An analytic formula for the increase in variance in an energy selective x-ray system is derived. The formula is used to gain insight into the dependence of the increase in variance on the properties of the additional basis functions, the measurement noise covariance, and the source spectrum. The formula is also used with computer simulations to quantify the dependence of the additional variance on these factors. Simulated images of an object with three materials are used to demonstrate the trade-off of increased information with dimensionality and noise. The images are computed from energy selective data with a maximum likelihood estimator.Results: The increase in variance depends most importantly on the dimension and on the properties of the additional basis functions. With the attenuation coefficients of cortical bone, soft tissue, and adipose tissue as the basis functions, the increase in variance of the bone component from two to three dimensions is 1.4 × 10{sup 3}. With the soft tissue component, it is 2.7 × 10{sup 4}. If the attenuation coefficient of a high atomic number contrast agent is used as the third basis function, there is only a slight increase in the variance from two to three basis functions, 1.03 and 7.4 for the bone and soft tissue components, respectively. The changes in spectrum shape with beam hardening also have a substantial effect. They increase the variance by a factor of approximately 200 for the bone component and 220 for the soft tissue component as the soft tissue object thickness increases from 1 to 30 cm. Decreasing the energy resolution of the detectors increases the variance of the bone component markedly with three dimension processing, approximately a factor of 25 as the resolution decreases from 100 to 3 bins. The increase with two dimension processing for adipose tissue is a factor of two and with the contrast agent as the third material for two or three dimensions is also a factor of two for both components. The simulated images show that a maximum likelihood estimator can be used to process energy selective x-ray data to produce images with noise close to the CRLB.Conclusions: The method presented can be used to compute the effects of the object attenuation coefficients and the x-ray system properties on the relationship of dimensionality and noise in energy selective x-ray imaging systems.

  19. Majorana braiding with thermal noise

    E-Print Network [OSTI]

    Fabio L. Pedrocchi; David P. DiVincenzo

    2015-05-14T23:59:59.000Z

    We investigate the self-correcting properties of a network of Majorana wires, in the form of a trijunction, in contact with a parity-preserving thermal environment. As opposed to the case where Majoranas are immobile, braiding Majoranas within a trijunction introduces dangerous error processes that we identify. Such errors prevent the lifetime of the memory from increasing with the size of the system. We confirm our predictions with Monte Carlo simulations. Our findings put a fundamental restriction on the feasibility of this specific quantum computing architecture.

  20. COMPLETE SUPPRESSION OF THE M=2/N-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D

    SciTech Connect (OSTI)

    PETTY,CC; LAHAYE,LA; LUCE,TC; HUMPHREYS,DA; HYATT,AW; PRATER,R; STRAIT,EJ; WADE,MR

    2003-03-01T23:59:59.000Z

    A271 COMPLETE SUPPRESSION OF THE M=2/N-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D. The first suppression of the important and deleterious m=2/n=1 neoclassical tearing mode (NTM) is reported using electron cyclotron current drive (ECCD) to replace the ''missing'' bootstrap current in the island O-point. Experiments on the DIII-D tokamak verify the maximum shrinkage of the m=2/n=1 island occurs when the ECCD location coincides with the q = 2 surface. The DIII-D plasma control system is put into search and suppress mode to make small changes in the toroidal field to find and lock onto the optimum position, based on real time measurements of dB{sub {theta}}/dt, for complete m=2/n=1 NTM suppression by ECCD. The requirements on the ECCD for complete island suppression are well modeled by the modified Rutherford equation for the DIII-D plasma conditions.

  1. Calculation of Fire Severity Factors and Fire Non-Suppression Probabilities For A DOE Facility Fire PRA

    SciTech Connect (OSTI)

    Tom Elicson; Bentley Harwood; Jim Bouchard; Heather Lucek

    2011-03-01T23:59:59.000Z

    Over a 12 month period, a fire PRA was developed for a DOE facility using the NUREG/CR-6850 EPRI/NRC fire PRA methodology. The fire PRA modeling included calculation of fire severity factors (SFs) and fire non-suppression probabilities (PNS) for each safe shutdown (SSD) component considered in the fire PRA model. The SFs were developed by performing detailed fire modeling through a combination of CFAST fire zone model calculations and Latin Hypercube Sampling (LHS). Component damage times and automatic fire suppression system actuation times calculated in the CFAST LHS analyses were then input to a time-dependent model of fire non-suppression probability. The fire non-suppression probability model is based on the modeling approach outlined in NUREG/CR-6850 and is supplemented with plant specific data. This paper presents the methodology used in the DOE facility fire PRA for modeling fire-induced SSD component failures and includes discussions of modeling techniques for: • Development of time-dependent fire heat release rate profiles (required as input to CFAST), • Calculation of fire severity factors based on CFAST detailed fire modeling, and • Calculation of fire non-suppression probabilities.

  2. Loss and thermal noise in plasmonic waveguides

    SciTech Connect (OSTI)

    Syms, R. R. A., E-mail: r.syms@imperial.ac.uk; Solymar, L. [Optical and Semiconductor Devices Group, EEE Department, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)

    2014-06-07T23:59:59.000Z

    Rytov's theory of thermally generated radiation is used to find the noise in two-dimensional passive guides based on an arbitrary distribution of lossy isotropic dielectric. To simplify calculations, the Maxwell curl equations are approximated using difference equations that also permit a transmission-line analogy, and material losses are assumed to be low enough for modal losses to be estimated using perturbation theory. It is shown that an effective medium representation of each mode is valid for both loss and noise and, hence, that a one-dimensional model can be used to estimate the best achievable noise factor when a given mode is used in a communications link. This model only requires knowledge of the real and imaginary parts of the modal dielectric constant. The former can be found by solving the lossless eigenvalue problem, while the latter can be estimated using perturbation theory. Because of their high loss, the theory is most relevant to plasmonic waveguides, and its application is demonstrated using single interface, slab, and slot guide examples. The best noise performance is offered by the long-range plasmon supported by the slab guide.

  3. Radar signal pre-processing to suppress surface bounce and multipath

    DOE Patents [OSTI]

    Paglieroni, David W; Mast, Jeffrey E; Beer, N. Reginald

    2013-12-31T23:59:59.000Z

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes that return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  4. Reactor Neutrino Flux Uncertainty Suppression on Multiple Detector Experiments

    E-Print Network [OSTI]

    Andi Cucoanes; Pau Novella; Anatael Cabrera; Muriel Fallot; Anthony Onillon; Michel Obolensky; Frederic Yermia

    2015-01-02T23:59:59.000Z

    This publication provides a coherent treatment for the reactor neutrino flux uncertainties suppression, specially focussed on the latest $\\theta_{13}$ measurement. The treatment starts with single detector in single reactor site, most relevant for all reactor experiments beyond $\\theta_{13}$. We demonstrate there is no trivial error cancellation, thus the flux systematic error can remain dominant even after the adoption of multi-detector configurations. However, three mechanisms for flux error suppression have been identified and calculated in the context of Double Chooz, Daya Bay and RENO sites. Our analysis computes the error {\\it suppression fraction} using simplified scenarios to maximise relative comparison among experiments. We have validated the only mechanism exploited so far by experiments to improve the precision of the published $\\theta_{13}$. The other two newly identified mechanisms could lead to total error flux cancellation under specific conditions and are expected to have major implications on the global $\\theta_{13}$ knowledge today. First, Double Chooz, in its final configuration, is the only experiment benefiting from a negligible reactor flux error due to a $\\sim$90\\% geometrical suppression. Second, Daya Bay and RENO could benefit from their partial geometrical cancellation, yielding a potential $\\sim$50\\% error suppression, thus significantly improving the global $\\theta_{13}$ precision today. And third, we illustrate the rationale behind further error suppression upon the exploitation of the inter-reactor error correlations, so far neglected. So, our publication is a key step forward in the context of high precision neutrino reactor experiments providing insight on the suppression of their intrinsic flux error uncertainty, thus affecting past and current experimental results, as well as the design of future experiments.

  5. Arsenite suppression of BMP signaling in human keratinocytes

    SciTech Connect (OSTI)

    Phillips, Marjorie A.; Qin, Qin [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States); Hu, Qin; Zhao, Bin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Rice, Robert H., E-mail: rhrice@ucdavis.edu [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States)

    2013-06-15T23:59:59.000Z

    Arsenic, a human skin carcinogen, suppresses differentiation of cultured keratinocytes. Exploring the mechanism of this suppression revealed that BMP-6 greatly increased levels of mRNA for keratins 1 and 10, two of the earliest differentiation markers expressed, a process prevented by co-treatment with arsenite. BMP also stimulated, and arsenite suppressed, mRNA for FOXN1, an important transcription factor driving early keratinocyte differentiation. Keratin mRNAs increased slowly after BMP-6 addition, suggesting they are indirect transcriptional targets. Inhibition of Notch1 activation blocked BMP induction of keratins 1 and 10, while FOXN1 induction was largely unaffected. Supporting a requirement for Notch1 signaling in keratin induction, BMP increased levels of activated Notch1, which was blocked by arsenite. BMP also greatly decreased active ERK, while co-treatment with arsenite maintained active ERK. Inhibition of ERK signaling mimicked BMP by inducing keratin and FOXN1 mRNAs and by increasing active Notch1, effects blocked by arsenite. Of 6 dual-specificity phosphatases (DUSPs) targeting ERK, two were induced by BMP unless prevented by simultaneous exposure to arsenite and EGF. Knockdown of DUSP2 or DUSP14 using shRNAs greatly reduced FOXN1 and keratins 1 and 10 mRNA levels and their induction by BMP. Knockdown also decreased activated Notch1, keratin 1 and keratin 10 protein levels, both in the presence and absence of BMP. Thus, one of the earliest effects of BMP is induction of DUSPs, which increases FOXN1 transcription factor and activates Notch1, both required for keratin gene expression. Arsenite prevents this cascade by maintaining ERK signaling, at least in part by suppressing DUSP expression. - Highlights: • BMP induces FOXN1 transcription. • BMP induces DUSP2 and DUSP14, suppressing ERK activation. • Arsenite suppresses levels of phosphorylated Smad1/5 and FOXN1 and DUSP mRNA. • These actions rationalize arsenite suppression of keratinocyte differentiation.

  6. A simplified model of decontamination by BWR steam suppression pools

    SciTech Connect (OSTI)

    Powers, D.A.

    1997-05-01T23:59:59.000Z

    Phenomena that can decontaminate aerosol-laden gases sparging through steam suppression pools of boiling water reactors during reactor accidents are described. Uncertainties in aerosol properties, aerosol behavior within gas bubbles, and bubble behavior in plumes affect predictions of decontamination by steam suppression pools. Uncertainties in the boundary and initial conditions that are dictated by the progression of severe reactor accidents and that will affect predictions of decontamination by steam suppression pools are discussed. Ten parameters that characterize boundary and initial condition uncertainties, nine parameters that characterize aerosol property and behavior uncertainties, and eleven parameters that characterize uncertainties in the behavior of bubbles in steam suppression pools are identified. Ranges for the values of these parameters and subjective probability distributions for parametric values within the ranges are defined. These uncertain parameters are used in Monte Carlo uncertainty analyses to develop uncertainty distributions for the decontamination that can be achieved by steam suppression pools and the size distribution of aerosols that do emerge from such pools. A simplified model of decontamination by steam suppression pools is developed by correlating features of the uncertainty distributions for total decontamination factor, DF(total), mean size of emerging aerosol particles, d{sub p}, and the standard deviation of the emerging aerosol size distribution, {sigma}, with pool depth, H. Correlations of the median values of the uncertainty distributions are suggested as the best estimate of decontamination by suppression pools. Correlations of the 10 percentile and 90 percentile values of the uncertainty distributions characterize the uncertainty in the best estimates. 295 refs., 121 figs., 113 tabs.

  7. Robust Microphone Array Signal Processing against Diffuse Noise

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.4 Structure of the thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Chapter-filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.3.3 Blind noise decorrelation . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.4 State . . . . . . . . . . . . . . . . . . . 29 3.2.2 Fixed noise coherence model . . . . . . . . . . . . . . . . . . . . . . . 30 3.2.3 Blind

  8. On the Radiated Noise of the Autosub AUV

    E-Print Network [OSTI]

    Griffiths, Gwyn

    diagnostic worn bearings damaged propeller blades ... #12;Fisheries Research Vessel avoidance study;Radiated noise of Container Ship 1 #12;FRV Scotia: Noise reduction measures t The engine is diesel

  9. Noise removal at the rod synapse of mammalian retina 

    E-Print Network [OSTI]

    van Rossum, Mark; Smith, Robert

    1998-01-01T23:59:59.000Z

    Mammalian rods respond to single photons with a hyperpolarization of about 1 mV which is accompanied by continuous noise. Since the mammalian rod bipolar cell collects signals from 20-100 rods, the noise from the converging ...

  10. Random Offset Curves and Surfaces with Controllable Noise (Extended Abstract)

    E-Print Network [OSTI]

    Lee, In-Kwon

    similar complex patterns often being able to be defined with the gradient noise functions. PORN is defined by replacing a static offset distance in a general offset with a gradient noise function. For example, PORN

  11. Modeling and managing separation for noise abatement arrival procedures

    E-Print Network [OSTI]

    Ren, Liling

    2007-01-01T23:59:59.000Z

    Aircraft noise is a significant concern to communities near airports, and therefore a constraint to the growth of aviation. Advanced noise abatement approach and arrival procedures have been shown in previous studies and ...

  12. On the reliability of attenuation measurements from ambient noise crosscorrelations

    E-Print Network [OSTI]

    Johnson, Cari

    an earthquake in Nevada and a mining blast in Wyoming. We demonstrate that com- mon ambient noise data is needed to understand the effect of uneven noise source dis- tribution prior to estimation of local

  13. Active noise control of supersonic impinging jet using pulsed microjets

    E-Print Network [OSTI]

    Hong, Seung Hyuck

    2009-01-01T23:59:59.000Z

    This thesis concerns an active noise control of supersonic impinging jet flow using unsteady microjet injection. Supersonic impinging jet involves several problems such as lift loss, ground erosion, significant noise ...

  14. Microscopic models for charge-noise-induced dephasing of solid-state qubits

    E-Print Network [OSTI]

    Félix Beaudoin; W. A. Coish

    2014-12-17T23:59:59.000Z

    Several experiments have shown qubit coherence decay of the form $\\mathrm{exp}[-(t/T_2)^\\alpha]$ due to environmental charge-noise fluctuations. We present a microscopic description for temperature dependences of the parameters $T_2$ and $\\alpha$. Our description is appropriate to qubits in semiconductors interacting with spurious two-level charge fluctuators coupled to a thermal bath. We find distinct power-law dependences of $T_2$ and $\\alpha$ on temperature depending on the nature of the interaction of the fluctuators with the associated bath. We consider fluctuator dynamics induced by first- and second-order tunneling with a continuum of delocalized electron states. We also study one- and two-phonon processes for fluctuators in either GaAs or Si. These results can be used to identify dominant charge-dephasing mechanisms and suppress them.

  15. Increasing LIGO sensitivity by feedforward subtraction of auxiliary length control noise

    E-Print Network [OSTI]

    Grant David Meadors; Keita Kawabe; Keith Riles

    2014-04-24T23:59:59.000Z

    LIGO, the Laser Interferometer Gravitational-wave Observatory, has been designed and constructed to measure gravitational wave strain via differential arm length. The LIGO 4-km Michelson arms with Fabry-Perot cavities have auxiliary length control servos for suppressing Michelson motion of the beam-splitter and arm cavity input mirrors, which degrades interferometer sensitivity. We demonstrate how a post-facto pipeline (AMPS) improves a data sample from LIGO Science Run 6 with feedforward subtraction. Dividing data into 1024-second windows, we numerically fit filter functions representing the frequency-domain transfer functions from Michelson length channels into the gravitational-wave strain data channel for each window, then subtract the filtered Michelson channel noise (witness) from the strain channel (target). In this paper we describe the algorithm, assess achievable improvements in sensitivity to astrophysical sources, and consider relevance to future interferometry.

  16. Role of thermal noise in tripartite quantum steering

    E-Print Network [OSTI]

    Meng Wang; Qihuang Gong; Zbigniew Ficek; Qiongyi He

    2014-08-10T23:59:59.000Z

    The influence of thermal noise on bipartite and tripartite quantum steering induced by a short laser pulse in a hybrid three-mode optomechanical system is investigated. The calculation is carried out under the bad cavity limit, the adiabatic approximation of a slowly varying amplitude of the cavity mode, and with the assumption of driving the cavity mode with a blue detuned strong laser pulse. Under such conditions, explicit expressions of the bipartite and tripartite steering parameters are obtained, and the concept of collective tripartite quantum steering, recently introduced by He and Reid [Phys. Rev. Lett. 111, 250403 (2013)], is clearly explored. It is found that both bipartite and tripartite steering parameters are sensitive functions of the initial state of the modes and distinctly different steering behaviour could be observed depending on whether the modes were initially in a thermal state or not. We find that the initial thermal noise is more effective in destroying the bipartite rather than the tripartite steering which, on the other hand, can persist even for a large thermal noise. For the initial vacuum state of a steered mode, the tripartite steering exists over the entire interaction time even if the steering modes are in very noisy thermal states. When the steered mode is initially in a thermal state, it can be collectively steered by the other modes. There are thresholds for the average number of the thermal photons above which the existing tripartite steering appears as the collective steering. Finally, we point out that the collective steering may provide a resource in a hybrid quantum network for quantum secret sharing protocol.

  17. Suppression of radio frequency knock out in stacked beams by phase shifting the betatron oscillations

    E-Print Network [OSTI]

    Terwilliger, K M

    1957-01-01T23:59:59.000Z

    Suppression of radio frequency knock out in stacked beams by phase shifting the betatron oscillations

  18. Fire suppression efficiency screening using a counterflow cylindrical burner

    SciTech Connect (OSTI)

    Yang, J.C.; Donnelly, M.K.; Prive, N.; Grosshandler, W.L.

    1999-07-01T23:59:59.000Z

    The design and validation of a counterflow cylindrical burner for fire suppression efficiency screening are described. The stability limits of the burner were mapped using various fuel (propane) and oxidizer (air) flows. The stability envelopes compared favorably with those reported in the literature. The apparatus was characterized using inert gases (argon, helium, and nitrogen), and the relative fire suppression efficiency ranking of these three gases was found to be commensurate with that from cup-burner tests. For liquid suppression experiments, a piezoelectric droplet generator was used to form droplets (<100 {micro}m). Water was used as a representative liquid suppressant to study the feasibility of using such a burner for screening liquid agents. Extinction was facilitated with the addition of water droplets, and the effect of water became more pronounced when its application rate was increased. Suppression experiments using water with and without nitrogen dilution in the oxidizer stream were also performed. Flame extinction due to the combined effect of water and nitrogen dilution was demonstrated.

  19. $J/?$ suppression in the threshold model and QGP formation time

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2007-09-03T23:59:59.000Z

    In the QGP motivated threshold model, in addition to the normal nuclear absorption, $J/\\psi$'s are subjected to an additional "anomalous" suppression. We have analysed the recently published PHENIX data on the participant number dependence of the nuclear modification factor for $J/\\psi$'s in Au+Au collisions and extracted the anomalous suppression required to explain the data. At mid rapidity $J/\\psi$'s are anomalously suppressed only above a threshold density $n_c$=3.73 fm$^{-2}$. The forward rapidity data on the otherhand require that $J/\\psi$'s are continuously "anomalously" suppressed. The analysis strongly indicate that in mid rapidity $J/\\psi$'s are suppressed in a deconfined medium. Using the PHENIX data on the participant number dependence of the Bjorken energy density, we have also estimated the QGP formation time. For critical temperature $T_c$=192 MeV, estimated QGP formation time ranges between 0.06-0.08 fm/c.

  20. Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pazsit

    E-Print Network [OSTI]

    Pázsit, Imre

    Review Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pa and application of the numerical tools employed. The code that was developed yields the space and non-critical systems with an external source. Some appli- cations of these tools to power reactor

  1. Implementation problem for the canonical commutation relation in terms of quantum white noise derivatives

    SciTech Connect (OSTI)

    Ji, Un Cig [Department of Mathematics, Research Institute of Mathematical Finance, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Obata, Nobuaki [Graduate School of Information Sciences, Tohoku University, Sendai 980-8579 (Japan)

    2010-12-15T23:59:59.000Z

    The implementation problem for the canonical commutation relation is reduced to a system of differential equations for Fock space operators containing new type of derivatives. We solve these differential equations systematically by means of quantum white noise calculus, and obtain the solution to the implementation problem.

  2. A Low Noise and High Dynamic Charge Sensitive Amplifier-Shaper associated with Silicon Strip

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A Low Noise and High Dynamic Charge Sensitive Amplifier-Shaper associated with Silicon Strip designed and fabricated in 0.35 µm CMOS process from Austria Micro System to be coupled with the Silicon a Charge Sensitive Amplifier (CSA) followed by two parallel CR-RC shapers. Slow and fast shapers, with 1

  3. Neutron noise calculations using the Analytical Nodal Method and comparisons with analytical solutions

    E-Print Network [OSTI]

    Demazière, Christophe

    Available online 28 December 2010 Keywords: Neutron noise ANM Power reactor approximation 2-Group theory, 2004). The reactor transfer function was calculated in 2- group diffusion theory for 2D systems using of Technology, Department of Nuclear Engineering, SE-412 96 Gothenburg, Sweden a r t i c l e i n f o Article

  4. Low-noise Readout IC with Integrated Analog-to-Digital Conversion for Radiation

    E-Print Network [OSTI]

    Stanacevic, Milutin

    of CSA and shaper of 2.2 mW. I. INTRODUCTION As the threat of the illicit use of the nuclear devicesLow-noise Readout IC with Integrated Analog-to-Digital Conversion for Radiation Detection System or materials grows, the need for the development of more accu- rate radiological detection devices

  5. Analysis of neutron noise spectra using neural networks

    SciTech Connect (OSTI)

    Korsah, K. (Oak Ridge National Lab., TN (USA)); Uhrig, R.E. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))

    1991-01-01T23:59:59.000Z

    Neural network architectures based on the back-propagation paradigm have been developed to recognize the features, and detect resonance shifts in, power spectral density (PSD) data. Our goal is to advance the state of the art in the application of noise analysis techniques to monitor nuclear reactor internals. The initial objectives have been to use PSD data, acquired over a period of about 2 years by PSDREC (power spectral density recognition system), to develop neural networks that are able to differentiate between normal neutron power spectral density data and anomalous spectral data, and detect significant shifts in the positions of spectral resonances while reducing the effect of small shifts. Neural network systems referred to in this paper as spectral feature detectors (SFDs) and integral network filters have been developed to meet these objectives. The performance of the SFDs is the subject of this paper. 2 refs., 2 figs.

  6. Blue Noise through Optimal Transport Fernando de Goes

    E-Print Network [OSTI]

    Desbrun, Mathieu

    Blue Noise through Optimal Transport Fernando de Goes Caltech Katherine Breeden Stanford Victor high-quality blue noise point distributions of arbitrary density functions. At its core is a novel diagrams. Our mathematical, algorithmic, and practical contributions lead to high-quality blue noise point

  7. Separating Signal from Noise in Global Warming Bert W. Rust

    E-Print Network [OSTI]

    Rust, Bert W.

    Separating Signal from Noise in Global Warming Bert W. Rust Reprinted from the CD Rust, B. W. (2003) "Separating Signal from Noise in Global Warming," Computing Science and Statistics, 35, 263-277. ­ or ­ Rust, B. W. (2003) "Separating Signal from Noise in Global Warming," Computing Science and Statistics, 35

  8. Perturbation theory for a stochastic process with Ornstein-Uhlenbeck noise

    E-Print Network [OSTI]

    Michael Wilkinson

    2009-11-15T23:59:59.000Z

    The Ornstein-Uhlenbeck process may be used to generate a noise signal with a finite correlation time. If a one-dimensional stochastic process is driven by such a noise source, it may be analysed by solving a Fokker-Planck equation in two dimensions. In the case of motion in the vicinity of an attractive fixed point, it is shown how the solution of this equation can be developed as a power series. The coefficients are determined exactly by using algebraic properties of a system of annihilation and creation operators.

  9. Acoustic Noise Test Report for the Viryd CS8 Wind Turbine

    SciTech Connect (OSTI)

    Roadman, J.; Huskey, A.

    2013-07-01T23:59:59.000Z

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the Viryd CS8 is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and binning by wind speed instead of regression analysis.

  10. Acoustic Noise Test Report for the SWIFT Wind Turbine in Boulder, CO

    SciTech Connect (OSTI)

    Roadman, J.; Huskey, A.

    2013-04-01T23:59:59.000Z

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the SWIFT is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and utilized binning by wind speed instead of regression analysis.

  11. Shot-noise-limited magnetometer with sub-pT sensitivity at room temperature

    E-Print Network [OSTI]

    Vito Giovanni Lucivero; Pawel Anielski; Wojciech Gawlik; Morgan W. Mitchell

    2014-11-20T23:59:59.000Z

    We report a photon shot-noise-limited (SNL) optical magnetometer based on amplitude modulated optical rotation using a room-temperature $^{85}$Rb vapor in a cell with anti-relaxation coating. The instrument achieves a room-temperature sensitivity of $70$ fT/$\\sqrt{\\mathrm{Hz}}$ at $7.6$ $\\mu$T. Experimental scaling of noise with optical power, in agreement with theoretical predictions, confirms the SNL behaviour from $5$ $\\mu$T to $75$ $\\mu$T. The combination of best-in-class sensitivity and SNL operation makes the system a promising candidate for application of squeezed light to a state-of-the-art atomic sensor.

  12. Zero-point energy in the Johnson noise of resistors: Is it there?

    E-Print Network [OSTI]

    Kish, Laszlo B

    2015-01-01T23:59:59.000Z

    There is a longstanding debate about the zero-point term in the Johnson noise voltage of a resistor: Is it indeed there or is it only an experimental artifact due to the uncertainty principle for phase-sensitive amplifiers? We show that, when the zero-point term is measured by the mean energy and force in a shunting capacitor and, if these measurements confirm its existence, two types of perpetual motion machines could be constructed. Therefore an exact quantum theory of the Johnson noise must include also the measurement system used to evaluate the observed quantities. The results have implications also for phenomena in advanced nanotechnology.

  13. Zero-point energy in the Johnson noise of resistors: Is it there?

    E-Print Network [OSTI]

    Laszlo B. Kish

    2015-05-01T23:59:59.000Z

    There is a longstanding debate about the zero-point term in the Johnson noise voltage of a resistor: Is it indeed there or is it only an experimental artifact due to the uncertainty principle for phase-sensitive amplifiers? We show that, when the zero-point term is measured by the mean energy and force in a shunting capacitor and, if these measurements confirm its existence, two types of perpetual motion machines could be constructed. Therefore an exact quantum theory of the Johnson noise must include also the measurement system used to evaluate the observed quantities. The results have implications also for phenomena in advanced nanotechnology.

  14. Reactor Neutrino Flux Uncertainty Suppression on Multiple Detector Experiments

    E-Print Network [OSTI]

    Cucoanes, Andi; Cabrera, Anatael; Fallot, Muriel; Onillon, Anthony; Obolensky, Michel; Yermia, Frederic

    2015-01-01T23:59:59.000Z

    This publication provides a coherent treatment for the reactor neutrino flux uncertainties suppression, specially focussed on the latest $\\theta_{13}$ measurement. The treatment starts with single detector in single reactor site, most relevant for all reactor experiments beyond $\\theta_{13}$. We demonstrate there is no trivial error cancellation, thus the flux systematic error can remain dominant even after the adoption of multi-detector configurations. However, three mechanisms for flux error suppression have been identified and calculated in the context of Double Chooz, Daya Bay and RENO sites. Our analysis computes the error {\\it suppression fraction} using simplified scenarios to maximise relative comparison among experiments. We have validated the only mechanism exploited so far by experiments to improve the precision of the published $\\theta_{13}$. The other two newly identified mechanisms could lead to total error flux cancellation under specific conditions and are expected to have major implications o...

  15. Alcohol-induced suppression of the humoral immune response

    SciTech Connect (OSTI)

    Stolen, J.S.; Draxler, S.; Nagle, J.J.

    1985-01-01T23:59:59.000Z

    The authors report here that summer flounder (Paralichthys dentatus) pretreated by injection of a small amount of the common alcohol, ethanol, or ethanol containing PCB, showed complete suppression of the immune response to a formalin-killed sewage sludge isolate of the human enteric bacteria, E. coli. The unresponsiveness persisted for up to 42 days after injection of bacteria. Demonstrable agglutinating antibody to E. coli was seen in unpretreated fish after seven days. A second injection of bacteria 42 days after the first in pretreated fish, now resulted in immune responsiveness although the magnitude of the response resembled a primary response, indicating that memory to the first injection was also suppressed. Slightly lower responses were seen in the groups of fish injected with ethanol containing the PCB Aroclor 1254 when compared with those given ethanol alone, but the major suppression was alcohol-induced.

  16. Evaluating charge noise acting on semiconductor quantum dots in the circuit quantum electrodynamics architecture

    SciTech Connect (OSTI)

    Basset, J.; Stockklauser, A.; Jarausch, D.-D.; Frey, T.; Reichl, C.; Wegscheider, W.; Wallraff, A.; Ensslin, K.; Ihn, T. [Solid State Physics Laboratory, ETH Zurich, CH-8093 Zurich (Switzerland)

    2014-08-11T23:59:59.000Z

    We evaluate the charge noise acting on a GaAs/GaAlAs based semiconductor double quantum dot dipole-coupled to the voltage oscillations of a superconducting transmission line resonator. The in-phase (I) and the quadrature (Q) components of the microwave tone transmitted through the resonator are sensitive to charging events in the surrounding environment of the double dot with an optimum sensitivity of 8.5×10{sup ?5}?e/?(Hz). A low frequency 1/f type noise spectrum combined with a white noise level of 6.6×10{sup ?6} e{sup 2}/Hz above 1?Hz is extracted, consistent with previous results obtained with quantum point contact charge detectors on similar heterostructures. The slope of the 1/f noise allows to extract a lower bound for the double-dot charge qubit dephasing rate which we compare to the one extracted from a Jaynes-Cummings Hamiltonian approach. The two rates are found to be similar emphasizing that charge noise is the main source of dephasing in our system.

  17. Direct-to-digital holography reduction of reference hologram noise and fourier space smearing

    DOE Patents [OSTI]

    Voelkl, Edgar

    2006-06-27T23:59:59.000Z

    Systems and methods are described for reduction of reference hologram noise and reduction of Fourier space smearing, especially in the context of direct-to-digital holography (off-axis interferometry). A method of reducing reference hologram noise includes: recording a plurality of reference holograms; processing the plurality of reference holograms into a corresponding plurality of reference image waves; and transforming the corresponding plurality of reference image waves into a reduced noise reference image wave. A method of reducing smearing in Fourier space includes: recording a plurality of reference holograms; processing the plurality of reference holograms into a corresponding plurality of reference complex image waves; transforming the corresponding plurality of reference image waves into a reduced noise reference complex image wave; recording a hologram of an object; processing the hologram of the object into an object complex image wave; and dividing the complex image wave of the object by the reduced noise reference complex image wave to obtain a reduced smearing object complex image wave.

  18. Thermo-elastic induced phase noise in the LISA Pathfinder spacecraft

    E-Print Network [OSTI]

    Ferran Gibert; Miquel Nofrarias; Nikolaos Karnesis; Lluís Gesa; Víctor Martín; Ignacio Mateos; Alberto Lobo; Reinhold Flatscher; Domenico Gerardi; Johannes Burkhardt; Ruediger Gerndt; David Robertson; Henry Ward; Paul William McNamara; Felipe Guzmán; Martin Hewitson; Ingo Diepholz; Jens Reiche; Gerhard Heinzel; Karsten Danzmann

    2014-12-12T23:59:59.000Z

    During the On-Station Thermal Test campaign of the LISA Pathfinder the data and diagnostics subsystem was tested in nearly space conditions for the first time after integration in the satellite. The results showed the compliance of the temperature measurement system, obtaining temperature noise around $10^{-4}\\,{\\rm K}\\, {\\rm Hz}^{-1/2}$ in the frequency band of $1-30\\;{\\rm mHz}$. In addition, controlled injection of heat signals to the suspension struts anchoring the LISA Technology Package (LTP) Core Assembly to the satellite structure allowed to experimentally estimate for the first time the phase noise contribution through thermo-elastic distortion of the LTP interferometer, the satellite's main instrument. Such contribution was found to be at $10^{-12}\\,{\\rm m}\\, {\\rm Hz}^{-1/2}$, a factor of 30 below the measured noise at the lower end of the measurement bandwidth ($1\\,{\\rm mHz}$).

  19. Influence of refraction on wind turbine noise

    E-Print Network [OSTI]

    Makarewicz, Rufin

    2013-01-01T23:59:59.000Z

    A semi-empirical method is applied to calculate the time-average sound level of wind turbine noise generation and propagation. Both are affected by wind shear refraction. Under upwind conditions the partially ensonified zone separates the fully ensonified zone (close to the turbine) and the shadow zone (far away from the turbine). Refraction is described in terms of the wind speed linear profile fitted to the power law profile. The rotating blades are treated as a two-dimensional circular source in the vertical plane. Inside the partially ensonified zone the effective A-weighted sound power decreases to zero when the receiver moves from the turbine toward the shadow zone. The presented results would be useful in practical applications to give a quick estimate of the effect of refraction on wind turbine noise.

  20. Thermophoresis of Brownian particles driven by coloured noise

    E-Print Network [OSTI]

    Scott Hottovy; Giovanni Volpe; Jan Wehr

    2012-10-02T23:59:59.000Z

    The Brownian motion of microscopic particles is driven by the collisions with the molecules of the surrounding fluid. The noise associated with these collisions is not white, but coloured due, e.g., to the presence of hydrodynamic memory. The noise characteristic time scale is typically of the same order as the time over which the particle's kinetic energy is lost due to friction (inertial time scale). We demonstrate theoretically that, in the presence of a temperature gradient, the interplay between these two characteristic time scales can have measurable consequences on the particle long-time behaviour. Using homogenization theory, we analyse the infinitesimal generator of the stochastic differential equation describing the system in the limit where the two characteristic times are taken to zero; from this generator, we derive the thermophoretic transport coefficient, which, we find, can vary in both magnitude and sign, as observed in experiments. Furthermore, studying the long-term stationary particle distribution, we show that particles can accumulate towards the colder (positive thermophoresis) or the warmer (negative thermophoresis) regions depending on the dependence of their physical parameters and, in particular, their mobility on the temperature.

  1. A compact, multichannel, and low noise arbitrary waveform generator

    SciTech Connect (OSTI)

    Govorkov, S. [Sema Systems, 302-5553 16th ave., Delta, British Columbia V4M 2H7 (Canada)] [Sema Systems, 302-5553 16th ave., Delta, British Columbia V4M 2H7 (Canada); Ivanov, B. I. [Leibniz-Institute of Photonic Technology, PO Box 100239, D-07702 Jena (Germany) [Leibniz-Institute of Photonic Technology, PO Box 100239, D-07702 Jena (Germany); Novosibirsk State Technical University, K.Marx-Ave. 20, Novosibirsk 630092 (Russian Federation); Il'ichev, E.; Meyer, H.-G. [Leibniz-Institute of Photonic Technology, PO Box 100239, D-07702 Jena (Germany)] [Leibniz-Institute of Photonic Technology, PO Box 100239, D-07702 Jena (Germany)

    2014-05-15T23:59:59.000Z

    A new type of high functionality, fast, compact, and easy programmable arbitrary waveform generator for low noise physical measurements is presented. The generator provides 7 fast differential waveform channels with a maximum bandwidth up to 200 MHz frequency. There are 6 fast pulse generators on the generator board with 78 ps time resolution in both duration and delay, 3 of them with amplitude control. The arbitrary waveform generator is additionally equipped with two auxiliary slow 16 bit analog-to-digital converters and four 16 bit digital-to-analog converters for low frequency applications. Electromagnetic shields are introduced to the power supply, digital, and analog compartments and with a proper filter design perform more than 110 dB digital noise isolation to the output signals. All the output channels of the board have 50 ? SubMiniature version A termination. The generator board is suitable for use as a part of a high sensitive physical equipment, e.g., fast read out and manipulation of nuclear magnetic resonance or superconducting quantum systems and any other application, which requires electromagnetic interference free fast pulse and arbitrary waveform generation.

  2. The detection of signals buried in noise

    E-Print Network [OSTI]

    Bergamaschi, Luigi; Giordani, Laura; Mana, Giovanni; Oddone, Massimo

    2013-01-01T23:59:59.000Z

    This paper examines signal detection in the presence of noise, with a particular emphasis to the nuclear activation analysis. The problem is to decide what between the signal-plus-background and no-signal hypotheses fits better the data and to quantify the relevant signal amplitude or detection limit. Our solution is based on the use of Bayesian inferences to test the different hypotheses.

  3. Heat Equations with Fractional White Noise Potentials

    SciTech Connect (OSTI)

    Hu, Y. [Department of Mathematics, University of Kansas, 405 Snow Hall, Lawrence, KS 66045-2142 (United States)], E-mail: hu@math.ukans.edu

    2001-07-01T23:59:59.000Z

    This paper is concerned with the following stochastic heat equations: ({partial_derivative}u{sub t}(x))/({partial_derivative}t=1/2 u{sub t}(x)+{omega}{sup H}.u{sub t}(x)), x element of {sup d}, t>0, where w{sup H} is a time independent fractional white noise with Hurst parameter H=(h{sub 1}, h{sub 2},..., h{sub d}) , or a time dependent fractional white noise with Hurst parameter H=(h{sub 0}, h{sub 1},..., h{sub d}) . Denote | H | =h{sub 1}+h{sub 2}+...+h{sub d} . When the noise is time independent, it is shown that if 1/2 d-1 , then the solution is in L{sub 2} and the L{sub 2} -Lyapunov exponent of the solution is estimated. When the noise is time dependent, it is shown that if 1/2 d- 2 /( 2h{sub 0}-1 ) , the solution is in L{sub 2} and the L{sub 2} -Lyapunov exponent of the solution is also estimated. A family of distribution spaces S{sub {rho}} , {rho} element of RR , is introduced so that every chaos of an element in S{sub {rho}} is in L{sub 2} . The Lyapunov exponents in S{sub {rho}} of the solution are also estimated.

  4. An alternative model of jet suppression at RHIC energies

    E-Print Network [OSTI]

    Lietava, R; Pisútová, N; Tomasik, Boris; Lietava, Roman; Pisut, Jan; Pisutova, Neva; Tomasik, Boris

    2003-01-01T23:59:59.000Z

    We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

  5. Viscoelastic Suppression of Gravity-Driven Counterflow Instability

    E-Print Network [OSTI]

    Beiersdorfer, P; Layne, D; Magee, E W

    2010-01-01T23:59:59.000Z

    Attempts to achieve ``top kill'' of actively flowing oil wells by insertion of dense drilling ``muds'', i.e., slurries of dense minerals, from above will fail if the Kelvin-Helmholtz instability in the gravity-driven counterflow produces turbulence that breaks up the denser fluid into small droplets. Here we estimate the droplet size to be sub-mm for fast flows and suggest the addition of a shear-thickening polymer to suppress turbulence. Laboratory experiments show a progression from droplet formation to complete turbulence suppression at the relevant high velocities, illustrating rich new physics accessible by using a shear-thickening liquid in gravity driven counter-streaming flows.

  6. An alternative model of jet suppression at RHIC energies

    E-Print Network [OSTI]

    Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

    2003-02-10T23:59:59.000Z

    We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

  7. Suppressing Proton Decay in Theories with Localised Fermions

    E-Print Network [OSTI]

    Bobby S. Acharya; Roberto Valandro

    2006-08-01T23:59:59.000Z

    We calculate the contribution to the proton decay amplitude from Kaluza-Klein lepto-quarks in theories with extra dimensions, localised fermions and gauge fields which propagate in the bulk. Such models naturally occur within the context of M-theory. In SU(5) models we show that carefully including all such modes gives a distinctive pattern of decays through various channels including a strong suppression of decays into neutrinos or right handed positrons. By contrast there is no such suppression for SO(10).

  8. Noise performance of magneto-inductive cables

    SciTech Connect (OSTI)

    Wiltshire, M. C. K., E-mail: michael.wiltshire@imperial.ac.uk; Syms, R. R. A. [Optical and Semiconductor Devices Group, Department of Electrical and Electronic Engineering, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)

    2014-07-21T23:59:59.000Z

    Magneto-inductive (MI) waveguides are metamaterial structures based on periodic arrangements of inductively coupled resonant magnetic elements. They are of interest for power transfer, communications and sensing, and can be realised in a flexible cable format. Signal-to-noise ratio is extremely important in applications involving signals. Here, we present the first experimental measurements of the noise performance of metamaterial cables. We focus on an application involving radiofrequency signal transmission in internal magnetic resonance imaging (MRI), where the subdivision of the metamaterial cable provides intrinsic patient safety. We consider MI cables suitable for use at 300 MHz during {sup 1}H MRI at 7 T, and find noise figures of 2.3–2.8?dB/m, together with losses of 3.0–3.9?dB/m, in good agreement with model calculations. These values are high compared to conventional cables, but become acceptable when (as here) the environment precludes the use of continuous conductors. To understand this behaviour, we present arguments for the fundamental performance limitations of these cables.

  9. Optimization of Geoscience Laser Altimeter System waveform metrics to support vegetation measurements

    E-Print Network [OSTI]

    Lefsky, Michael

    Optimization of Geoscience Laser Altimeter System waveform metrics to support vegetation GLAS Optimization Remote sensing Vegetation structure The Geoscience Laser Altimeter System (GLAS) has optimized a noise coefficient which could be constant or vary according to observation period or noise

  10. Inductively coupled plasma spectrometry: Noise characteristics of aerosols, application of generalized standard additions method, and Mach disk as an emission source

    SciTech Connect (OSTI)

    Shen, Luan

    1995-10-06T23:59:59.000Z

    This dissertation is focused on three problem areas in the performance of inductively coupled plasma (ICP) source. The noise characteristics of aerosols produced by ICP nebulizers are investigated. A laser beam is scattered by aerosol and detected by a photomultiplier tube and the noise amplitude spectrum of the scattered radiation is measured by a spectrum analyzer. Discrete frequency noise in the aerosol generated by a Meinhard nebulizer or a direct injection nebulizer is primarily caused by pulsation in the liquid flow from the pump. A Scott-type spray chamber suppresses white noise, while a conical, straight-pass spray chamber enhances white noise, relative to the noise seen from the primary aerosol. Simultaneous correction for both spectral interferences and matrix effects in ICP atomic emission spectrometry (AES) can be accomplished by using the generalized standard additions method (GSAM). Results obtained with the application of the GSAM to the Perkin-Elmer Optima 3000 ICP atomic emission spectrometer are presented. The echelle-based polychromator with segmented-array charge-coupled device detectors enables the direct, visual examination of the overlapping lines Cd (1) 228.802 nm and As (1) 228.812 nm. The slit translation capability allows a large number of data points to be sampled, therefore, the advantage of noise averaging is gained. An ICP is extracted into a small quartz vacuum chamber through a sampling orifice in a water-cooled copper plate. Optical emission from the Mach disk region is measured with a new type of echelle spectrometer equipped with two segmented-array charge-coupled-device detectors, with an effort to improve the detection limits for simultaneous multielement analysis by ICP-AES.

  11. SUPPRESSION OF DIELECTRONIC RECOMBINATION DUE TO FINITE DENSITY EFFECTS

    SciTech Connect (OSTI)

    Nikolic, D.; Gorczyca, T. W.; Korista, K. T. [Western Michigan University, Kalamazoo, MI (United States); Ferland, G. J. [University of Kentucky, Lexington, KY (United States); Badnell, N. R. [University of Strathclyde, Glasgow (United Kingdom)

    2013-05-01T23:59:59.000Z

    We have developed a general model for determining density-dependent effective dielectronic recombination (DR) rate coefficients in order to explore finite-density effects on the ionization balance of plasmas. Our model consists of multiplying by a suppression factor those highly-accurate total zero-density DR rate coefficients which have been produced from state-of-the-art theoretical calculations and which have been benchmarked by experiment. The suppression factor is based upon earlier detailed collision-radiative calculations which were made for a wide range of ions at various densities and temperatures, but used a simplified treatment of DR. A general suppression formula is then developed as a function of isoelectronic sequence, charge, density, and temperature. These density-dependent effective DR rate coefficients are then used in the plasma simulation code Cloudy to compute ionization balance curves for both collisionally ionized and photoionized plasmas at very low (n{sub e} = 1 cm{sup -3}) and finite (n{sub e} = 10{sup 10} cm{sup -3}) densities. We find that the denser case is significantly more ionized due to suppression of DR, warranting further studies of density effects on DR by detailed collisional-radiative calculations which utilize state-of-the-art partial DR rate coefficients. This is expected to impact the predictions of the ionization balance in denser cosmic gases such as those found in nova and supernova shells, accretion disks, and the broad emission line regions in active galactic nuclei.

  12. Suppressed serum prolactin in sinoaortic-denervated rats

    SciTech Connect (OSTI)

    Alexander, N.; Melmed, S.; Morris, M.

    1987-02-01T23:59:59.000Z

    The authors investigated the effect of arterial baroreceptor deafferentation on serum and pituitary prolactin (PRL) and on catecholamines in median eminence (ME) and anterior and posterior pituitaries. Male Wistar rats were sinoaortic denervated (SAD) or sham operated (SO). Three days after surgery serum prolactin, measured by radioimmunoassay, was suppressed in SAD rats, and dopamine (DA) and norepinephrine (NE) concentrations, measured by radioenzymatic or high-performance liquid chromatography electron capture methods, were significantly reduced in ME of SAD rats. Simultaneously, anterior pituitary of SAD rats had significant increases in both catecholamines, whereas posterior pituitary showed no changes. Four hours after surgery serum PRL was also reduced in SAD rats, but no changes in ME catecholamines were found. Mean arterial pressure (MAP) and heart rate were measured before and after injection of bromocriptine in SAD and SO rats 3 days after surgery. Bromocriptine markedly suppressed serum PRL in both groups and reduced MAP from 144 +/- 10 to 84 +/- 5 and from 116 +/- 2 to 99 +/- 3 in SAD and SO rats, respectively; heart rate was reduced in SAD rats. They conclude that the SAD rat is a model of hypertension with suppressed serum PRL and that interruption of arterial baroreceptor nerves suppresses PRL secretion probably by modulating tuberoinfundibular turnover of catecholamines.

  13. Range Sidelobe Suppression in a Desired Doppler Interval

    E-Print Network [OSTI]

    Pezeshki, Ali

    is sensitive to Doppler effect. Off the zero- Doppler axis the ambiguity function of Golay pairs of phase codedRange Sidelobe Suppression in a Desired Doppler Interval Yuejie Chi,1 Ali Pezeshki,2 Robert--We present a novel method of constructing a Doppler resilient pulse train of Golay complementary waveforms

  14. Seismic shape parameters estimation and ground-roll suppression using

    E-Print Network [OSTI]

    Spagnolini, Umberto

    Seismic shape parameters estimation and ground-roll suppression using vector-sensor beamforming the problem of estimating the shape parameters of seismic wavefields in linear arrays. The purpose of the subsurface layers from the seismic wavefields registered by surface sensors. However, only the waves

  15. Stochastic storage models and noise-induced phase transitions

    E-Print Network [OSTI]

    Serge Shpyrko; V. V. Ryazanov

    2007-01-13T23:59:59.000Z

    The most frequently used in physical application diffusive (based on the Fokker-Planck equation) model leans upon the assumption of small jumps of a macroscopic variable for each given realization of the stochastic process. This imposes restrictions on the description of the phase transition problem where the system is to overcome some finite potential barrier, or systems with finite size where the fluctuations are comparable with the size of a system. We suggest a complementary stochastic description of physical systems based on the mathematical stochastic storage model with basic notions of random input and output into a system. It reproduces statistical distributions typical for noise-induced phase transitions (e.g. Verhulst model) for the simplest (up to linear) forms of the escape function. We consider a generalization of the stochastic model based on the series development of the kinetic potential. On the contrast to Gaussian processes in which the development in series over a small parameter characterizing the jump value is assumed [Stratonovich R.L., Nonlinear Nonequilibrium Thermodynamics, Springer Series in Synergetics, vol.59, Springer Verlag, 1994], we propose a series expansion directly suitable for storage models and introduce the kinetic potential generalizing them.

  16. MOLECULAR MECHANISM OF SUPPRESSION OF NEOPLASTIC TRANSFORMATION BY LOW DOSES OF LOW LET RADIATION

    SciTech Connect (OSTI)

    J.LESIE REDPATH, PH.D.

    2011-03-29T23:59:59.000Z

    We are currently funded (9/01-8/04) by the DOE Low Dose Radiation Research Program to examine mechanisms underlying the suppression of neoplastic transformation in vitro by low doses of low LET radiation. For the new studies proposed under Notice 04-21, we intend to follow up on our observation that upregulation of DNA repair may be an important factor and that its importance is dose-dependent. The experimental system will be the human hybrid cell neoplastic transformation assay that we are currently using. We propose to test the following hypothesis: Down-regulation of DNA dsb repair will abrogate the low dose suppression of neoplastic transformation. Using the technique of RNA silencing, it is proposed to test the effect of down-regulation of the two major DNA dsb repair pathways, homologous recombination (HR) and non-homologous end-joining (NHEJ), on the dose response relationship for neoplastic transformation. Based on prior studies, we predict that this will result in abrogation of the suppressive effect at doses in the range 1 to 10 cGy, but not at lower doses. The proposed experiments will also help address the question as to which of the two DNA repair pathways may be the most important in causing suppression of transformation. HR is a pathway that is predominant in S and G2 phase cells and is known to be less error-prone than the NHEJ pathway that is predominant in G1 phase. We hypothesize that down-regulation of HR will result in the most effective abrogation of suppression. An important component of this study will be the determination of the how abrogation of DNA dsb repair impacts the spontaneous transformation frequency, presumably a consequence of endogeneous DNA damage. Experiments will be carried out using partially synchronized populations of cells enriched for G1 and S/G2 respectively. In addition to the endpoint of neoplastic transformation the impact of down-regulation of HR and NHEJ on the formation and disappearance of the DNA dsb marker, gamma-H2AX, will be studied.

  17. Deconfinement as an entropic self-destruction: a solution for the quarkonium suppression puzzle?

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

    Kharzeev, Dmitri E. [Stony Brook Univ, Department of Physics and Astronomy, NY (United States); Brookhaven National Laboratory, Department of Physics, Upton, NY (United States)

    2014-10-01T23:59:59.000Z

    The entropic approach to dissociation of bound states immersed in strongly coupled systems is developed. In such systems, the excitations of the bound state are often delocalized and characterized by a large entropy, so that the bound state is strongly entangled with the rest of the statistical system. If this entropy S increases with the separation r between the constituents of the bound state, S=S(r), then the resulting entropic force F=T ?S/?r (T is temperature) can drive the dissociation process. As a specific example, we consider the case of heavy quarkonium in strongly coupled quark-gluon plasma, where lattice QCD indicates a large amount of entropy associated with the heavy quark pair at temperatures 0.9Tc?T?1.5Tc (Tc is the deconfinement temperature); this entropy S(r) grows with the interquark distance r. We argue that the entropic mechanism results in an anomalously strong quarkonium suppression in the temperature range near Tc. This entropic self-destruction may thus explain why the experimentally measured quarkonium nuclear modification factor at RHIC (lower energy density) is smaller than at LHC (higher energy density), possibly resolving the “quarkonium suppression puzzle”—all of the previously known mechanisms of quarkonium dissociation operate more effectively at higher energy densities, and this contradicts the data. Moreover, we find that near Tc the entropic force leads to delocalization of the bound hadron states; we argue that this delocalization may be the mechanism underlying deconfinement.

  18. Deconfinement as an entropic self-destruction: a solution for the quarkonium suppression puzzle?

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

    Kharzeev, Dmitri E.

    2014-10-01T23:59:59.000Z

    The entropic approach to dissociation of bound states immersed in strongly coupled systems is developed. In such systems, the excitations of the bound state are often delocalized and characterized by a large entropy, so that the bound state is strongly entangled with the rest of the statistical system. If this entropy S increases with the separation r between the constituents of the bound state, S=S(r), then the resulting entropic force F=T ?S/?r (T is temperature) can drive the dissociation process. As a specific example, we consider the case of heavy quarkonium in strongly coupled quark-gluon plasma, where lattice QCD indicatesmore »a large amount of entropy associated with the heavy quark pair at temperatures 0.9Tc?T?1.5Tc (Tc is the deconfinement temperature); this entropy S(r) grows with the interquark distance r. We argue that the entropic mechanism results in an anomalously strong quarkonium suppression in the temperature range near Tc. This entropic self-destruction may thus explain why the experimentally measured quarkonium nuclear modification factor at RHIC (lower energy density) is smaller than at LHC (higher energy density), possibly resolving the “quarkonium suppression puzzle”—all of the previously known mechanisms of quarkonium dissociation operate more effectively at higher energy densities, and this contradicts the data. Moreover, we find that near Tc the entropic force leads to delocalization of the bound hadron states; we argue that this delocalization may be the mechanism underlying deconfinement.« less

  19. Noise-assisted Thouless pump in elastically deformable molecular junctions

    E-Print Network [OSTI]

    C. A. Perroni; F. Romeo; A. Nocera; V. Marigliano Ramaglia; R. Citro; V. Cataudella

    2014-04-16T23:59:59.000Z

    We study a Thouless pump realized with an elastically \\textit{deformable quantum dot} whose center of mass follows a non-linear stochastic dynamics. The interplay of noise, non-linear effects, dissipation and interaction with an external time-dependent driving on the pumped charge is fully analyzed. The results show that the quantum pumping mechanism not only is not destroyed by the force fluctuations, but it becomes stronger when the forcing signal frequency is tuned close to the resonance of the vibrational mode. The robustness of the quantum pump with temperature is also investigated and an exponential decay of the pumped charge is found when the coupling to the vibrational mode is present. Implications of our results for nano-electromechanical systems are also discussed.

  20. Low Dose Suppression of Neoplastic Transformation in Vitro

    SciTech Connect (OSTI)

    John Leslie Redpath

    2012-05-01T23:59:59.000Z

    This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

  1. Effects of Tidal Turbine Noise on Fish Hearing and Tissues - Draft Final Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect (OSTI)

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30T23:59:59.000Z

    Snohomish Public Utility District No.1 plans to deploy two 6 meter OpenHydro tidal turbines in Admiralty Inlet in Puget Sound, under a FERC pilot permitting process. Regulators and stakeholders have raised questions about the potential effect of noise from the turbines on marine life. Noise in the aquatic environment is known to be a stressor to many types of aquatic life, including marine mammals, fish and birds. Marine mammals and birds are exceptionally difficult to work with for technical and regulatory reasons. Fish have been used as surrogates for other aquatic organisms as they have similar auditory structures. This project was funded under the FY09 Funding Opportunity Announcement (FOA) to Snohomish PUD, in partnership with the University of Washington - Northwest National Marine Renewable Energy Center, the Sea Mammal Research Unit, and Pacific Northwest National Laboratory. The results of this study will inform the larger research project outcomes. Proposed tidal turbine deployments in coastal waters are likely to propagate noise into nearby waters, potentially causing stress to native organisms. For this set of experiments, juvenile Chinook salmon (Oncorhynchus tshawytscha) were used as the experimental model. Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study was performed during FY 2011 to determine if noise generated by a 6-m diameter OpenHydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. Naturally spawning stocks of Chinook salmon that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Chinook/CKPUG.cfm); the fish used in this experiment were hatchery raised and their populations are not in danger of depletion. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Experimental results indicate that non-lethal, low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

  2. Apparatus and method for suppressing vibration and displacement of a bellows

    DOE Patents [OSTI]

    Kuklo, T.C.

    1984-01-01T23:59:59.000Z

    Flexible bellows are utilized between two systems, such as a pumping system and a process station, to partially absorb system vibrations and to compensate for misalignment between the systems. It is common practice to either clamp a rigid spacer between flanges of the two systems to separate them from each other, or to maintain the bellows in unsupported relationship between these systems. In the former bellows arrangement, the rigid spacer transmits vibratory energy between the two systems and the bellows tends to function as an undamped or underdamped unit that resonates at its own frequency to create additional vibratory energy, transmitted to the systems. In the latter, unsupported bellows arrangement, the pressure differential prevalent between the fluid flowing through the bellows and ambient normally causes extension or retraction of the bellows and resulting misalignment problems. The present invention substantially solves the above vibration and misalignment problems by providing an inflatable tube in surrounding relationship about a bellows to suppress vibration and displacement thereof. A method for isolating first and second systems from each other to prevent the transmission of vibratory energy therebetween comprises the steps of attaching at least one flexible bellows between the systems, surrounding the bellows with an inflatable tube, and maintaining a predetermined pressure in the tube to urge the tube in flexible contact with at least some of the convolutions of the bellows.

  3. Active compressor engine silencer reduces exhaust noise

    SciTech Connect (OSTI)

    Denenberg, J.N.; Miller, S.K. (Noise Cancellation Technologies, Inc., Stamford, CT (United States)); Jay, M.A. (Walker Noise Cancellation Technologies, Grass Lake, MI (United States))

    1994-01-01T23:59:59.000Z

    An active industrial silencer on a compressor engine at a Tenneco Gas station has reduced low-frequency rumbling' noise by 8 dB during trials while lowering backpressure about 90$. This 8 dB reduction of the piston firing frequency corresponds to a more than 80% decrease in emitted acoustic power. The silencing unit, installed on one of six engines at the station near Eden, N.Y., continues in operation. Based on the results, the manufacturer is identifying additional compressor sites for further tests. This paper reviews this project.

  4. Broadband, noise-free optical quantum memory with neutral nitrogen-vacancy centers in diamond

    E-Print Network [OSTI]

    E. Poem; C. Weinzetl; J. Klatzow; K. T. Kaczmarek; J. H. D. Munns; T. F. M. Champion; D. J. Saunders; J. Nunn; I. A. Walmsley

    2015-01-11T23:59:59.000Z

    It is proposed that the ground-state manifold of the neutral nitrogen-vacancy center in diamond could be used as a quantum two-level system in a solid-state-based implementation of a broadband, noise-free quantum optical memory. The proposal is based on the same-spin $\\Lambda$-type three level system created between the two E orbital ground states and the A$_1$ orbital excited state of the center, and the cross-linear polarization selection rules obtained with the application of transverse electric field or uniaxial stress. Possible decay and decoherence mechanisms of this system are discussed, and it is shown that high efficiency, noise-free storage of photons with a bandwidth of a few tens of GHz for a few tens of nanoseconds would be possible at low temperature.

  5. 1430 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 32, NO. 9, SEPTEMBER 1997 A Scalable High-Frequency Noise Model for

    E-Print Network [OSTI]

    Voinigescu, Sorin Petre

    modeling, low noise, low-noise amplifier, low-noise transistor design, noise figure, noise matching, noise noise parameter equa- tions, are applied in the design of tuned low-noise amplifiers (LNA's) in the 2-Frequency Noise Model for Bipolar Transistors with Application to Optimal Transistor Sizing for Low-Noise

  6. Electric motor/controller design tradeoffs for noise, weight, and efficiency

    SciTech Connect (OSTI)

    Kopp, N.L.; Brown, G.W.

    1994-12-31T23:59:59.000Z

    It is common for an AUV [Autonomous Underwater Vehicle] designer to be put in the position of a subsystem hardware integrator. In the case of electric motors and controllers this may be more by necessity than choice because a suitable subsystems supplier cannot be found. As a result, motors and controllers are purchased from various manufacturers who may optimize the design of each part but hold system performance secondary in importance. Unlike hydraulics, an electric motor/controller system presents significant opportunities to improve noise, weight, and efficiency. But, these opportunities can best be recognized by a single source who not only understands the technology but has the ability to implement them in the development and manufacture of the product. An analysis is presented which explains the various design considerations of noise, weight and efficiency of electric motors and controllers for submersible AUV`s. In concert with the design considerations, their interrelationships are discussed as to how they affect each other in the overall optimization of the system. In conclusion, a matrix is created which shows how the resultant system parameters of noise, weight, and efficiency may be ``traded off`` to tailor the best overall system for the application. 1 ref.

  7. Recent Developments in Quantum White Noise Calculus: Quantum White Noise Derivatives and Implementation Problem

    E-Print Network [OSTI]

    Obata, Nobuaki

    ) is defined by . . (H) = { = (fn) ; fn Hn , 2 = n=0 n!|fn|2 0 ) ), respectively. (The pair {at, a t ; t T } is called the quantum white noise on T .) Definition Given l,m (E(l+m,m (E(l+m) ) , where the right-hand side converges

  8. Detecting noise with shot noise using on-chip photon detector

    E-Print Network [OSTI]

    Jompol, Y.; Roulleau, P.; Jullien, T.; Roche, B.; Ritchie, D. A.; Glattli, D. C.

    2015-01-27T23:59:59.000Z

    for on-chip radiation detection. It is based on the low-frequency current noise generated by the partitioning of photon-excited electrons and holes, which are scattered inside the conductor. For a given electromagnetic coupling to the radiation...

  9. Spectral Noise Correlations of an Ultrafast Frequency Comb

    E-Print Network [OSTI]

    Roman Schmeissner; Jonathan Roslund; Claude Fabre; Nicolas Treps

    2014-10-16T23:59:59.000Z

    Cavity-based noise detection schemes are combined with ultrafast pulse shaping as a means to diagnose the spectral correlations of both the amplitude and phase noise of an ultrafast frequency comb. The comb is divided into ten spectral regions, and the distribution of noise as well as the correlations between all pairs of spectral regions are measured against the quantum limit. These correlations are then represented in the form of classical noise matrices, which furnish a complete description of the underlying comb dynamics. Their eigendecomposition reveals a set of theoretically predicted, decoupled noise modes that govern the dynamics of the comb. Finally, the matrices contain the information necessary to deduce macroscopic noise properties of the comb.

  10. Undecimated Wavelet Transforms for Image De-noising

    SciTech Connect (OSTI)

    Gyaourova, A; Kamath, C; Fodor, I K

    2002-11-19T23:59:59.000Z

    A few different approaches exist for computing undecimated wavelet transform. In this work we construct three undecimated schemes and evaluate their performance for image noise reduction. We use standard wavelet based de-noising techniques and compare the performance of our algorithms with the original undecimated wavelet transform, as well as with the decimated wavelet transform. The experiments we have made show that our algorithms have better noise removal/blurring ratio.

  11. The optimal suppression of a low-cost technology by a durable-good monopoly

    E-Print Network [OSTI]

    Karp, Larry; Perloff, Jeffrey M

    1994-01-01T23:59:59.000Z

    SUPPRESSION OF A LOW-COST TECHNOLOGY BY A DURABLE-GOODsuppression of a low-cost technology by a durable-goodSuppression of a Low-Cost Technology by a Durable-Good

  12. airport noise: Topics by E-print Network

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

    Summary: aircraft engines and those of other sectors, particularly the operating environment, and issues of safetyaircraft noise, and suggested that there were also likely to...

  13. acoustic noise reduction: Topics by E-print Network

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

    acoustic receivers of vessels using spectral subtraction Physics Websites Summary: , cavitation etc. created by the propellers generate immense acoustic noise in the vicinity...

  14. airports aircraft noise: Topics by E-print Network

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

    63 Air freight : the problems of airport restrictions : final report on the Conference of Air Cargo Industry Considerations of Airport Curfews MIT - DSpace Summary: Noise...

  15. aircraft noise annoyance: Topics by E-print Network

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

    including safety aspects. The investigations and experiments in the multinational European project Vormann, Matthias 14 APPENDIX E REVIEW OF EFFECTS OF AIRCRAFT NOISE, CHAFF,...

  16. Integration of Noise and Coda Correlation Data into Kinematic...

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

    Integration of Noise and Coda Correlation Data into Kinematic and Waveform Inversions presentation at the April 2013 peer review meeting held in Denver, Colorado....

  17. aerodynamic noise propagation: Topics by E-print Network

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

    not known in full detail in experiments. For weak propagating microwaves, the detection process requires linear amplifiers which obscure the signal with random noise. Here, we...

  18. ambient ocean noise: Topics by E-print Network

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

    of anisotropy in oceanic ambient noise fields and its relevance to Acoustic Daylight imaging CiteSeer Summary: Acoustic Daylight is a new technique for creating pictorial...

  19. acoustic noise: Topics by E-print Network

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

    of anisotropy in oceanic ambient noise fields and its relevance to Acoustic Daylight imaging CiteSeer Summary: Acoustic Daylight is a new technique for creating pictorial...

  20. airborne acoustical noise: Topics by E-print Network

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

    of anisotropy in oceanic ambient noise fields and its relevance to Acoustic Daylight imaging CiteSeer Summary: Acoustic Daylight is a new technique for creating pictorial...

  1. aircraft noise monitoring: Topics by E-print Network

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

    there is a clear need to manageCitizen Noise Pollution Monitoring Nicolas Maisonneuve Sony Computer Science Laboratory Paris pollution involving citizens and built upon the...

  2. absolute johnson noise: Topics by E-print Network

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

    as information carrier with peculiar properties. Relevant examples are Zero power (stealth) communication, Unconditionally secure communication with Johnson(-like) noise and...

  3. Review of Subcritical Source-Driven Noise Analysis Measurements

    SciTech Connect (OSTI)

    Valentine, T.E.

    1999-11-01T23:59:59.000Z

    Subcritical source-driven noise measurements are simultaneous Rossia and randomly pulsed neutron measurements that provide measured quantities that can be related to the subcritical neutron multiplication factor. In fact, subcritical source-driven noise measurements should be performed in lieu of Rossia measurements because of the additional information that is obtained from noise measurements such as the spectral ratio and the coherence functions. The basic understanding of source-driven noise analysis measurements can be developed from a point reactor kinetics model to demonstrate how the measured quantities relate to the subcritical neutron multiplication factor.

  4. Optical analog of Rabi oscillation suppression due to atomic motion

    E-Print Network [OSTI]

    J. G. Muga; B. Navarro

    2005-05-13T23:59:59.000Z

    The Rabi oscillations of a two-level atom illuminated by a laser on resonance with the atomic transition may be suppressed by the atomic motion through averaging or filtering mechanisms. The optical analogs of these velocity effects are described. The two atomic levels correspond in the optical analogy to orthogonal polarizations of light and the Rabi oscillations to polarization oscillations in a medium which is optically active, naturally or due to a magnetic field. In the later case, the two orthogonal polarizations could be selected by choosing the orientation of the magnetic field, and one of them be filtered out. It is argued that the time-dependent optical polarization oscillations or their suppression are observable with current technology.

  5. Suppression MHD instabilities by IBW heating in HT-7 Tokamak

    E-Print Network [OSTI]

    C. M. Qin; Y. P. Zhao; X. J. Zhang; P. Xu; Y. Yang; the HT-7 team

    2010-01-21T23:59:59.000Z

    In HT-7 tokamak, the m= 2/1 tearing mode can be effectively suppressed by the ion bernstein wave (IBW) when the location of power deposition is near the q=2 rational surface. Off-axis electron heating and greatly increase of electron density was observed, in the meantime, the particle confinement appears to be improved with the increased of the central line averaged electron density and the drop of Da emission. Induced large ne gradients and pressures were spatially correlated with the IBW deposition profile by theoretical calculation >. It is suggested that off-axis IBW heating modifies the electron pressure profile, and so the current density profile could be redistributed resulting in the suppression of the magnetohydrodynamics (MHD) instability. It provides an integrated way for making combined effects on both the stabilization of tearing modes and controlling of pressure profile.

  6. Nuclear absorption and $J/?$ suppression in Pb+Pb collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2002-03-18T23:59:59.000Z

    We have analyzed the NA58 data on $J/\\psi$ suppression in Pb+Pb collisions. $J/\\psi$ production is assumed to be a two step process, (i) formation of $c\\bar{c}$ pair, which is accurately calculable in QCD and (ii) formation of $J/\\psi$ meson from the $c\\bar{c}$ pair, which can be conveniently parameterized. In a pA/AA collision, a $c\\bar{c}$ pair gain relative square momentum as it passes through the nuclear medium and some of the $c\\bar{c}$ pairs can gain enough momentum to cross the threshold to become an open charm meson, leading to suppression in pA/AA collisions. A new prescription is proposed for the gain in momentum square, consistent with Krammer process. The model without any free parameter could explain the $E_T$ dependence of $J/\\psi$ over Drell-Yan ratio.

  7. Depression and the Ironic Effects of Thought Suppression: Therapeutic Strategies for ImprovingMental Control

    E-Print Network [OSTI]

    Beevers, Christopher

    are espc- cially likely to engage in thought suppression in an at- tempt to achieve mental control over

  8. Suppression of Rayleigh Taylor instability in strongly coupled plasmas

    SciTech Connect (OSTI)

    Das, Amita; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2014-06-15T23:59:59.000Z

    The Rayleigh Taylor instability in a strongly coupled plasma medium has been investigated using the equations of generalized hydrodynamics. It is demonstrated that the visco-elasticity of the strongly coupled medium due to strong inter particle correlations leads to a suppression of the Rayleigh Taylor instability unless certain threshold conditions are met. The relevance of these results to experiments on laser compression of matter to high densities including those related to inertial confinement fusion using lasers has also been shown.

  9. Suppression of large-scale perturbations by stiff solid

    E-Print Network [OSTI]

    Vladimír Balek; Matej Škovran

    2015-01-28T23:59:59.000Z

    Evolution of large-scale scalar perturbations in the presence of stiff solid (solid with pressure to energy density ratio > 1/3) is studied. If the solid dominated the dynamics of the universe long enough, the perturbations could end up suppressed by as much as several orders of magnitude. To avoid too steep large-angle power spectrum of CMB, radiation must have prevailed over the solid long enough before recombination.

  10. Suppression of large-scale perturbations by stiff solid

    E-Print Network [OSTI]

    Balek, Vladimír

    2015-01-01T23:59:59.000Z

    Evolution of large-scale scalar perturbations in the presence of stiff solid (solid with pressure to energy density ratio > 1/3) is studied. If the solid dominated the dynamics of the universe long enough, the perturbations could end up suppressed by as much as several orders of magnitude. To avoid too steep large-angle power spectrum of CMB, radiation must have prevailed over the solid long enough before recombination.

  11. RHIC and LHC jet suppression in non-central collisions

    E-Print Network [OSTI]

    Magdalena Djordjevic; Marko Djordjevic; Bojana Blagojevic

    2014-06-25T23:59:59.000Z

    Understanding properties of QCD matter created in ultra-relativistic heavy-ion collisions is a major goal of RHIC and LHC experiments. An excellent tool to study these properties is jet suppression of light and heavy flavor observables. Utilizing this tool requires accurate suppression predictions for different experiments, probes and experimental conditions, and their unbiased comparison with experimental data. With this goal, we here extend our dynamical energy loss formalism towards generating predictions for non-central collisions; the formalism takes into account both radiative and collisional energy loss, dynamical (as opposed to static) scattering centers, finite magnetic mass, running coupling and uses no free parameters in comparison with experimental data. Specifically, we here generate predictions for all available centrality ranges, for both LHC and RHIC experiments, and for four different probes (charged hadrons, neutral pions, D mesons and non-prompt $J/\\psi$). We obtain a very good agreement with all available non-central data, and also generate predictions for suppression measurements that will soon become available. Finally, we discuss implications of the obtained good agreement with experimental data with different medium models that are currently considered.

  12. $J/?$ suppression in Pb+Pb collisions, a conventional description

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2001-09-17T23:59:59.000Z

    We have analyzed the latest NA50 data on $J/\\psi$ suppression in Pb + Pb collisions. $J/\\psi$ production is assumed to be a two step process, (i) formation of $c\\bar{c}$ pair, which is accurately calculable in QCD and (ii) formation of $J/\\psi$ meson from the $c\\bar{c}$ pair, which can be conveniently parameterized. In a pA/AA collision, the as the $c\\bar{c}$ pair pass through the nuclear medium, it gain relative square momentum at the rate of $\\epsilon^2$ per unit path length. As a result, some of the $c\\bar{c}$ pairs can gain enough momentum to cross the threshold to become an open charm meson, leading to suppression in pA/AA collisions. The parameters of the model were fixed from experimental data on the total $J/\\psi$ cross section as a function of effective nuclear length. The model without any free parameter, give excellent description of NA50 data on $E_T$ dependence of $J/\\psi$ to Drell-Yan ratio. The model was applied to predict the $E_T$ dependence of $J/\\psi$ at RHIC energy. Much larger suppression of $J/\\psi$, in agreement with other model calculations are predicted.

  13. Edinburgh Research Explorer ERK2 Suppresses Self-Renewal Capacity of Embryonic Stem

    E-Print Network [OSTI]

    Koehn, Philipp

    Edinburgh Research Explorer ERK2 Suppresses Self-Renewal Capacity of Embryonic Stem Cells, T 2013, 'ERK2 Suppresses Self-Renewal Capacity of Embryonic Stem Cells, but Is Not Required for Multi date: 26. Jun. 2014 #12;ERK2 Suppresses Self-Renewal Capacity of Embryonic Stem Cells

  14. Efficiency-Droop Suppression by Using Large-Bandgap AlGaInN Thin Barrier

    E-Print Network [OSTI]

    Gilchrist, James F.

    Efficiency-Droop Suppression by Using Large-Bandgap AlGaInN Thin Barrier Layers in InGaN Quantum DOI: 10.1109/JPHOT.2013.2255028 1943-0655/$31.00 Ó2013 IEEE #12;Efficiency-Droop Suppression by Using with the consideration of carrier transport effect for efficiency droop suppression. The lattice-matched Al

  15. Noise pair velocity and range echo location system

    DOE Patents [OSTI]

    Erskine, D.J.

    1999-02-16T23:59:59.000Z

    An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution is disclosed. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna. 46 figs.

  16. Noise pair velocity and range echo location system

    DOE Patents [OSTI]

    Erskine, David J. (Oakland, CA)

    1999-01-01T23:59:59.000Z

    An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna.

  17. Enabling Green Energy and Propulsion Systems via Direct Noise Computation |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwoJanice Lovato March 10,Ron9Argonne

  18. Enabling Green Energy and Propulsion Systems via Direct Noise Computation |

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDaveArgonne Leadership Computing

  19. Realistic simulation of reduced-dose CT with noise modeling and sinogram synthesis using DICOM CT images

    SciTech Connect (OSTI)

    Won Kim, Chang [Interdisciplinary Program of Bioengineering Major Seoul National University College of Engineering, San 56-1, Silim-dong, Gwanak-gu, Seoul 152-742, South Korea and Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of)] [Interdisciplinary Program of Bioengineering Major Seoul National University College of Engineering, San 56-1, Silim-dong, Gwanak-gu, Seoul 152-742, South Korea and Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Kim, Jong Hyo, E-mail: kimjhyo@snu.ac.kr [Department of Radiology, Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul, 110-744 (Korea, Republic of); Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Gyeonggi-do, 443-270 (Korea, Republic of); Advanced Institutes of Convergence Technology, Seoul National University, Suwon, Gyeonggi-do, 443-270 (Korea, Republic of)

    2014-01-15T23:59:59.000Z

    Purpose: Reducing the patient dose while maintaining the diagnostic image quality during CT exams is the subject of a growing number of studies, in which simulations of reduced-dose CT with patient data have been used as an effective technique when exploring the potential of various dose reduction techniques. Difficulties in accessing raw sinogram data, however, have restricted the use of this technique to a limited number of institutions. Here, we present a novel reduced-dose CT simulation technique which provides realistic low-dose images without the requirement of raw sinogram data. Methods: Two key characteristics of CT systems, the noise equivalent quanta (NEQ) and the algorithmic modulation transfer function (MTF), were measured for various combinations of object attenuation and tube currents by analyzing the noise power spectrum (NPS) of CT images obtained with a set of phantoms. Those measurements were used to develop a comprehensive CT noise model covering the reduced x-ray photon flux, object attenuation, system noise, and bow-tie filter, which was then employed to generate a simulated noise sinogram for the reduced-dose condition with the use of a synthetic sinogram generated from a reference CT image. The simulated noise sinogram was filtered with the algorithmic MTF and back-projected to create a noise CT image, which was then added to the reference CT image, finally providing a simulated reduced-dose CT image. The simulation performance was evaluated in terms of the degree of NPS similarity, the noise magnitude, the bow-tie filter effect, and the streak noise pattern at photon starvation sites with the set of phantom images. Results: The simulation results showed good agreement with actual low-dose CT images in terms of their visual appearance and in a quantitative evaluation test. The magnitude and shape of the NPS curves of the simulated low-dose images agreed well with those of real low-dose images, showing discrepancies of less than +/?3.2% in terms of the noise power at the peak height and +/?1.2% in terms of the spatial frequency at the peak height. The magnitudes of the noise measured for 12 different combinations the phantom size, tube current, and reconstruction kernel for the simulated and real low-dose images were very similar, with differences of 0.1 to 4.7%. Thep value for a statistical testing of the difference in the noise magnitude ranged from 0.99 to 0.11, showing that there was no difference statistically between the noise magnitudes of the real and simulated low-dose images using our method. The strength and pattern of the streak noise in an anthropomorphic phantom was also consistent with expectations. Conclusions: A novel reduced-dose CT simulation technique was developed which uses only CT images while not requiring raw sinogram data. Our method can provide realistic simulation results under reduced-dose conditions both in terms of the noise magnitude and the textual appearance. This technique has the potential to promote clinical research for patient dose reductions.

  20. Directed motion generated by heat bath nonlinearly driven by external noise

    E-Print Network [OSTI]

    Jyotipratim Ray Chaudhuri; Debashis Barik; Suman Kumar Banik

    2007-11-02T23:59:59.000Z

    Based on the system heat bath approach where the bath is nonlinearly modulated by an external Gaussian random force, we propose a new microscopic model to study directed motion in the overdamped limit for a nonequilibrium open system. Making use of the coupling between the heat bath and the external modulation as a small perturbation we construct a Langevin equation with multiplicative noise and space dependent dissipation and the corresponding Fokker-Planck-Smoluchowski equation in the overdamped limit. We examine the thermodynamic consistency condition and explore the possibility of observing a phase induced current as a consequence of state dependent diffusion and, necessarily, nonlinear driving of the heat bath by the external noise.

  1. Diffusion, dimensionality and noise in transcriptional regulation

    E-Print Network [OSTI]

    Gasper Tkacik; William Bialek

    2007-12-12T23:59:59.000Z

    The precision of biochemical signaling is limited by randomness in the diffusive arrival of molecules at their targets. For proteins binding to the specific sites on the DNA and regulating transcription, the ability of the proteins to diffuse in one dimension by sliding along the length of the DNA, in addition to their diffusion in bulk solution, would seem to generate a larger target for DNA binding, consequently reducing the noise in the occupancy of the regulatory site. Here we show that this effect is largely cancelled by the enhanced temporal correlations in one dimensional diffusion. With realistic parameters, sliding along DNA has surprisingly little effect on the physical limits to the precision of transcriptional regulation.

  2. Nonlinear GARCH model and 1/f noise

    E-Print Network [OSTI]

    Kononovicius, Aleksejus

    2014-01-01T23:59:59.000Z

    Auto-regressive conditionally heteroskedastic (ARCH) family models are still used, by practitioners in business and economic policy making, as a conditional volatility forecasting models. Furthermore ARCH models still are attracting an interest of the researchers. In this contribution we consider the well known GARCH(1,1) process and its nonlinear modifications, reminiscent of NGARCH model. We investigate the possibility to reproduce power law statistics, probability density function and power spectral density, using ARCH family models. For this purpose we derive stochastic differential equations from the GARCH processes in consideration. We find the obtained equations to be similar to a general class of stochastic differential equations known to reproduce power law statistics. We show that linear GARCH(1,1) process has power law distribution, but its power spectral density is Brownian noise-like. However, the nonlinear modifications exhibit both power law distribution and power spectral density of the power ...

  3. 11.1 Introduction Noise (a spontaneous fluctuation in current or in voltage) is generated in all semiconductor devices.

    E-Print Network [OSTI]

    Wilamowski, Bogdan Maciej

    The thermal noise is proportional to the frequency bandwidth f. It can be represented by the voltage sourceTf. The noise power density, dPn/df = kT, is independent of frequency. Thus, the thermal noise is the white and reliability. The most important sources of noise are thermal noise, shot noise, generation-recombination noise

  4. Indirect Combustion Noise: Experimental Investigation of the Vortex Sound Generation in a Choked

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Indirect Combustion Noise: Experimental Investigation of the Vortex Sound Generation in a Choked-27 April 2012, Nantes, France 2315 #12;Combustion noise in gas turbines consists of direct noise related to the unsteady combustion process itself and indirect noise. As known, indirect noise is produced when entropy

  5. ANALYSIS OF AN MTC NOISE MEASUREMENT PERFORMED IN RINGHALS-2 USING GAMMA-

    E-Print Network [OSTI]

    Demazière, Christophe

    ANALYSIS OF AN MTC NOISE MEASUREMENT PERFORMED IN RINGHALS-2 USING GAMMA- THERMOMETERS AND IN-averaged temperature noise was then used to estimate the MTC by noise analysis, via a new MTC noise estimator-thermometer. This shows that the main reason of the MTC underestimation by noise analysis in all the experimental work

  6. Chaos expansion of heat equations with white noise potentials

    E-Print Network [OSTI]

    Hu, Yaozhong

    2002-02-01T23:59:59.000Z

    The asymptotic behavior as t --> infinity of the solution to the following stochastic heat equations [GRAPHICS] is investigated, where w is a space-time white noise or a space white noise. The use of lozenge means that the stochastic integral of 10...

  7. Modeling of combustion noise spectrum from turbulent premixed flames

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modeling of combustion noise spectrum from turbulent premixed flames Y. Liu, A. P. Dowling, T. D, Nantes, France 2321 #12;Turbulent combustion processes generate sound radiation due to temporal changes, this temporal correlation and its role in the modeling of combustion noise spectrum are studied by analyzing

  8. CALCULATION OF THE NEUTRON NOISE INDUCED BY SHELL-MODE

    E-Print Network [OSTI]

    Demazière, Christophe

    CALCULATION OF THE NEUTRON NOISE INDUCED BY SHELL-MODE FISSION REACTORS CORE-BARREL VIBRATIONS-REGION SLAB REACTOR MODEL CARL SUNDE,* CHRISTOPHE DEMAZI�RE, and IMRE PÁZSIT Chalmers University of Technology for Publication October 12, 2005 The subject of this paper is the calculation of the in-core neutron noise induced

  9. Development of a 2-D 2-group neutron noise simulator

    E-Print Network [OSTI]

    Demazière, Christophe

    . This simulator calculates both the direct and the adjoint reactor transfer function between a stat- ionary noise applications. Consequently, the calculation of the dynamic reactor transfer function, i.e. the neutron noise demonstrated that the calculation of the dynamic reactor transfer function was possible mainly by modifying

  10. DESIGNING A KALMAN FILTER WHEN NO NOISE COVARIANCE INFORMATION IS

    E-Print Network [OSTI]

    Van den Hof, Paul

    DESIGNING A KALMAN FILTER WHEN NO NOISE COVARIANCE INFORMATION IS AVAILABLE Robert Bos ,1 Xavier Kalman filters using first principles models is often that these models lack a description of the noises that affect the states and the measurements. In these cases, the Kalman filter has to be estimated from data

  11. Kalman Filtering with Uncertain Noise Covariances Srikiran Kosanam Dan Simon

    E-Print Network [OSTI]

    Simon, Dan

    Kalman Filtering with Uncertain Noise Covariances Srikiran Kosanam Dan Simon Department.kosanam@csuohio.edu d.j.simon@csuohio.edu Abstract - In this paper the robustness of Kalman filtering against uncertainties in process and measurement noise covariances is discussed. It is shown that a standard Kalman

  12. Brief Communication Channel Noise is Essential for Perithreshold Oscillations in

    E-Print Network [OSTI]

    Dorval II, Alan D. "Chuck"

    Brief Communication Channel Noise is Essential for Perithreshold Oscillations in Entorhinal by the stochastic flicker of voltage-gated ion channels, can be a major contributor to electrical membrane noise of persistent Na channels is necessary for the existence of slow perithreshold oscillations that characterize

  13. Improved Signal-to-Noise Ratio Estimation for Speech Enhancement

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Improved Signal-to-Noise Ratio Estimation for Speech Enhancement Cyril Plapous, Member, IEEE speech enhancement in noisy environments. State-of- the-art short-time noise reduction techniques reduction techniques, includ- ing TSNR, introduce harmonic distortion in enhanced speech because

  14. SPEECH ENHANCEMENT FOR NOISE-ROBUST SPEECH RECOGNITION

    E-Print Network [OSTI]

    Shapiro, Benjamin

    SPEECH ENHANCEMENT FOR NOISE-ROBUST SPEECH RECOGNITION Vikramjit Mitra and Carol Y. Espy-Wilson Speech Communication Lab SCL Introduction Propose an adaptive speech enhancement technique. Detects SNR-robust Speech Recognition Speech Enhancement Noise robust automated transcription Corpus `Speech in Speech

  15. Diesel knock noise from combustion phenomenon to perceived signals

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Diesel knock noise from combustion phenomenon to perceived signals O. Sauvagea , A. Lauracb , M for reducing Diesel knock are modifications of engine parameters used for controlling combustion processes filters allowing realistic overall Diesel noise re-synthesises from cylinder pressure signals. Cylinder

  16. Noise Reduction of a Turbofan Bleed Valve Vincent Phong1

    E-Print Network [OSTI]

    Papamoschou, Dimitri

    Noise Reduction of a Turbofan Bleed Valve Vincent Phong1 , Shervin Taghavi Nezhad2 , Feng Liu3 and computational research effort investigated the noise sources of a pneumatic bleed valve used in turbofan engines, rapid-prototyped valve designs which enabled the exploration of a large parameter space. Microphone

  17. Optimal control of aeroacoustic noise generated by cylinder vortex interaction

    E-Print Network [OSTI]

    Heinkenschloss, Matthias

    of the blade resulting in a strong dipole type acoustic source. The noise generated by BVI is particularly severe, leading to environmental noise pollution in commercial applications and increased observability the fluid dynamics and acoustic mechanisms that result from BVI as well as to validate predictive techniques

  18. The Theta Laser A Low Noise Chirped Pulse Laser

    E-Print Network [OSTI]

    Van Stryland, Eric

    · Increased laser coherence · Ultra-low noise lasersOC ISO SOA #12;8 Approach Semiconductor-Based FrequencyThe Theta Laser A Low Noise Chirped Pulse Laser Dimitrios Mandridis dmandrid@creol.ucf.edu April 29, 2011 CREOL Affiliates Day 2011 #12;2 Objective: Frequency Swept (FM) Mode-locked Laser · Develop

  19. Low frequency noise from MW wind turbines --mechanisms of generation

    E-Print Network [OSTI]

    Low frequency noise from MW wind turbines -- mechanisms of generation and its modeling Helge MW wind turbines -- mechanisms of generation and its modeling Department: Department of Wind Energy turbine has been simulated with a noise prediction model from NASA in US. Running the model

  20. Trailing Edge Noise Model Applied to Wind Turbine Airfoils

    E-Print Network [OSTI]

    In order to increase public acceptance of wind energy in the coming years, there is a strong need Bertagnolio Title: Trailing Edge Noise Model Applied to Wind Turbine Airfoils Department: Wind EnergyTrailing Edge Noise Model Applied to Wind Turbine Airfoils Franck Bertagnolio Risø-R-1633(EN) Risø

  1. Relative intensity noise and frequency noise of a compact Brillouin laser made

    E-Print Network [OSTI]

    Boyer, Edmond

    made of 4.9 m long bulk As2Se3 (AsSe) chalcogenide fiber, which has a Brillouin gain coefficient g]. The purpose of this Letter is twofold: first to demonstrate the possibility of making compact BFLs made of AsSe performances in terms of intensity and frequency noise of a BFL made of chalco- genide MOF. The AsSe MOF [inset

  2. Further constraints on electron acceleration in solar noise storms

    E-Print Network [OSTI]

    Prasad Subramanian; Peter A. Becker

    2006-02-28T23:59:59.000Z

    We reexamine the energetics of nonthermal electron acceleration in solar noise storms. A new result is obtained for the minimum nonthermal electron number density required to produce a Langmuir wave population of sufficient intensity to power the noise storm emission. We combine this constraint with the stochastic electron acceleration formalism developed by Subramanian & Becker (2005) to derive a rigorous estimate for the efficiency of the overall noise storm emission process, beginning with nonthermal electron acceleration and culminating in the observed radiation. We also calculate separate efficiencies for the electron acceleration -- Langmuir wave generation stage and the Langmuir wave -- noise storm production stage. In addition, we obtain a new theoretical estimate for the energy density of the Langmuir waves in noise storm continuum sources.

  3. 1/f noise in semiconductor and metal nanocrystal solids

    SciTech Connect (OSTI)

    Liu, Heng, E-mail: leophy@gmail.com; Lhuillier, Emmanuel, E-mail: emmanuel.lhuillier@espci.fr; Guyot-Sionnest, Philippe [James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637 (United States)

    2014-04-21T23:59:59.000Z

    Electrical 1/f noise is measured in thin films of CdSe, CdSe/CdS, ZnO, HgTe quantum dots and Au nanocrystals. The 1/f noise, normalized per nanoparticle, shows no systematic dependence on the nanoparticle material and the coupling material. However, over 10 orders of magnitude, it correlates well with the nearest neighbor conductance suggesting some universal magnitude of the 1/f noise in these granular conductors. In the hopping regime, the main mechanism of 1/f noise is determined to be mobility fluctuated. In the metallic regime obtained with gold nanoparticle films, the noise drops to a similar level as bulk gold films and with a similar temperature dependence.

  4. 217 km long distance photon-counting optical time-domain reflectometry based on ultra-low noise up-conversion single photon detector

    E-Print Network [OSTI]

    Guo-Liang Shentu; Qi-Chao Sun; Xiao Jiang; Xiao-Dong Wang; Jason S. Pelc; M. M. Fejer; Qiang Zhang; Jian-Wei Pan

    2013-08-05T23:59:59.000Z

    We demonstrate a photon-counting optical time-domain reflectometry with 42.19 dB dynamic range using an ultra-low noise up-conversion single photon detector. By employing the long wave pump technique and a volume Bragg grating, we reduce the noise of our up-conversion single photon detector, and achieve a noise equivalent power of -139.7 dBm/sqrt(Hz). We perform the OTDR experiments using a fiber of length 216.95 km, and show that our system can identify defects along the entire fiber length with a distance resolution better than 10 cm in a measurement time of 13 minutes.

  5. Signal/noise enhancement strategies for stochastically estimated correlation functions

    E-Print Network [OSTI]

    William Detmold; Michael G. Endres

    2014-08-19T23:59:59.000Z

    We develop strategies for enhancing the signal/noise ratio for stochastically sampled correlation functions. The techniques are general and offer a wide range of applicability. We demonstrate the potential of the approach with a generic two-state system, and then explore the practical applicability of the method for single hadron correlators in lattice quantum chromodynamics. In the latter case, we determine the ground state energies of the pion, proton, and delta baryon, as well as the ground and first excited state energy of the rho meson using matrices of correlators computed on an exemplary ensemble of anisotropic gauge configurations. In the majority of cases, we find a modest reduction in the statistical uncertainties on extracted energies compared to conventional variational techniques. However, in the case of the delta baryon, we achieve a factor of three reduction in statistical uncertainties. The variety of outcomes achieved for single hadron correlators illustrates an inherent dependence of the method on the properties of the system under consideration and the operator basis from which the correlators are constructed.

  6. Noise-assisted quantum electron transfer in photosynthetic complexes

    E-Print Network [OSTI]

    Alexander I. Nesterov; Gennady P. Berman; José Manuel Sánchez Martínez; Richard T. Sayre

    2013-04-30T23:59:59.000Z

    Electron transfer (ET) between primary electron donors and acceptors is modeled in the photosystem II reaction center (RC). Our model includes (i) two discrete energy levels associated with donor and acceptor, interacting through a dipole-type matrix element and (ii) two continuum manifolds of electron energy levels ("sinks"), which interact directly with the donor and acceptor. Namely, two discrete energy levels of the donor and acceptor are embedded in their independent sinks through the corresponding interaction matrix elements. We also introduce classical (external) noise which acts simultaneously on the donor and acceptor (collective interaction). We derive a closed system of integro-differential equations which describes the non-Markovian quantum dynamics of the ET. A region of parameters is found in which the ET dynamics can be simplified, and described by coupled ordinary differential equations. Using these simplified equations, both sharp and flat redox potentials are analyzed. We analytically and numerically obtain the characteristic parameters that optimize the ET rates and efficiency in this system.

  7. Optimal suppression of defect generation during a passage across a quantum critical point

    E-Print Network [OSTI]

    Ning Wu; Arun Nanduri; Herschel Rabitz

    2014-12-09T23:59:59.000Z

    The dynamics of quantum phase transitions are inevitably accompanied by the formation of defects when crossing a quantum critical point. For a generic class of quantum critical systems, we solve the problem of minimizing the production of defects through the use of a gradient-based deterministic optimal control algorithm. By considering a finite size quantum Ising model with a tunable global transverse field, we show that an optimal power law quench of the transverse field across the Ising critical point works well at minimizing the number of defects, in spite of being drawn from a subset of quench profiles. These power law quenches are shown to be inherently robust against noise. The optimized defect density exhibits a transition at a critical ratio of the quench duration to the system size, which we argue coincides with the intrinsic speed limit for quantum evolution.

  8. Simulation of Thermal Stratification in BWR Suppression Pools with One Dimensional Modeling Method

    SciTech Connect (OSTI)

    Haihua Zhao; Ling Zou; Hongbin Zhang

    2014-01-01T23:59:59.000Z

    The suppression pool in a boiling water reactor (BWR) plant not only is the major heat sink within the containment system, but also provides the major emergency cooling water for the reactor core. In several accident scenarios, such as a loss-of-coolant accident and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; the pool temperature distribution also affects the NPSHa (available net positive suction head) and therefore the performance of the Emergency Core Cooling System and Reactor Core Isolation Cooling System pumps that draw cooling water back to the core. Current safety analysis codes use zero dimensional (0-D) lumped parameter models to calculate the energy and mass balance in the pool; therefore, they have large uncertainties in the prediction of scenarios in which stratification and mixing are important. While three-dimensional (3-D) computational fluid dynamics (CFD) methods can be used to analyze realistic 3-D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, resulting in a long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code (Berkeley mechanistic MIXing code in C++) has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by one-dimensional (1-D) transient partial differential equations and substructures (such as free or wall jets) are modeled with 1-D integral models. This allows very large reductions in computational effort compared to multi-dimensional CFD modeling. One heat-up experiment performed at the Finland POOLEX facility, which was designed to study phenomena relevant to Nordic design BWR suppression pool including thermal stratification and mixing, is used for validation. Comparisons between the BMIX++, GOTHIC, and CFD calculations against the POOLEX experimental data are discussed in detail.

  9. Deconfinement as an entropic self-destruction: a solution for the quarkonium suppression puzzle?

    SciTech Connect (OSTI)

    Kharzeev, Dmitri E. [Stony Brook Univ, Department of Physics and Astronomy, NY (United States); Brookhaven National Laboratory, Department of Physics, Upton, NY (United States)

    2014-10-01T23:59:59.000Z

    The entropic approach to dissociation of bound states immersed in strongly coupled systems is developed. In such systems, the excitations of the bound state are often delocalized and characterized by a large entropy, so that the bound state is strongly entangled with the rest of the statistical system. If this entropy S increases with the separation r between the constituents of the bound state, S=S(r), then the resulting entropic force F=T ?S/?r (T is temperature) can drive the dissociation process. As a specific example, we consider the case of heavy quarkonium in strongly coupled quark-gluon plasma, where lattice QCD indicates a large amount of entropy associated with the heavy quark pair at temperatures 0.9Tc?T?1.5Tc (Tc is the deconfinement temperature); this entropy S(r) grows with the interquark distance r. We argue that the entropic mechanism results in an anomalously strong quarkonium suppression in the temperature range near Tc. This entropic self-destruction may thus explain why the experimentally measured quarkonium nuclear modification factor at RHIC (lower energy density) is smaller than at LHC (higher energy density), possibly resolving the “quarkonium suppression puzzle”—all of the previously known mechanisms of quarkonium dissociation operate more effectively at higher energy densities, and this contradicts the data. Moreover, we find that near Tc the entropic force leads to delocalization of the bound hadron states; we argue that this delocalization may be the mechanism underlying deconfinement.

  10. Strangeness Suppression of qq? Creation Observed in Exclusive Reactions

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

    Mestayer, Mac [JLAB; Park, Kijun; Adhikari, Krishna; Aghasyan, Mher; Anefalos Pereira, Sergio; Ball, Jacques; Battaglieri, Marco; Batourine, V; Bedlinskiy, Ivan; Biselli, Angela; Boyarinov, Sergey; Briscoe, William; Brooks, William; Burkert, Volker; Carman, Daniel; Celentano, Andrea; Chandavar, Shloka; Charles, Gabriel; Colaneri, Luca; Cole, Philip; Contalbrigo, Marco; Cortes, Olga; Crede, Volker; D'Angelo, Annalisa; Dashyan, Natalya; De Vita, Raffaella; Deur, Alexandre; Djalali, Chaden; Doughty, David; Dupre, Raphael; El Alaoui, Ahmed; El Fassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Fleming, Jamie; Forest, Tony; Garillon, Brice; Garcon, Michel; Ghandilyan, Yeranuhi; Gilfoyle, Gerard; Giovanetti, Kevin; Girod-Gard, Francois-Xavier; Goetz, John; Golovach, Evgeny; Gothe, Ralf; Griffioen, Keith; Guegan, Baptiste; Guidal, Michel; Hakobyan, Hayk; Hanretty, Charles; Hattawy, Mohammad; Holtrop, Maurik; Hughes, Simon; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Jiang, Hao; Jo, Hyon-Suk; Joo, Kyungseon; Keller, Dustin; Khandaker, Mahbubul; Kim, Andrey; Kim, Wooyoung; Koirala, Suman; Kubarovsky, Valery; Kuleshov, Sergey; Lenisa, Paolo; Levine, William; Livingston, Ken; Lu, Haiyun; MacGregor, Ian; Mayer, Michael; McKinnon, Bryan; Meyer, Curtis; Mirazita, Marco; Mokeev, Viktor; Montgomery, Rachel; Moody, Cristina; Moutarde, Herve; Movsisyan, Aram; Munoz Camacho, Carlos; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria; Osipenko, Mikhail; Ostrovidov, Alexander; Pappalardo, Luciano; Paremuzyan, Rafayel; Peng, Peng; Phelps, William; Pisano, Silvia; Pogorelko, Oleg; Pozdniakov, Serguei; Price, John; Protopopescu, Dan; Puckett, Andrew; Raue, Brian; Rimal, Dipak; Ripani, Marco; Rizzo, Alessandro; Rosner, Guenther; Roy, Priyashree; Sabatie, Franck; Saini, Mukesh; Schott, Diane; Schumacher, Reinhard; Simonyan, Ani; Sokhan, Daria; Strauch, Steffen; Sytnik, Valeriy; Tang, Wei; Tian, Ye; Ungaro, Maurizio; Vernarsky, Brian; Vlasov, Alexander; Voskanyan, Hakob; Voutier, Eric; Walford, Natalie; Watts, Daniel; Wei, Xiangdong; Weinstein, Lawrence; Wood, Michael; Zachariou, Nicholas; Zhang, Jixie; Zhao, Zhiwen; Zonta, Irene

    2014-10-01T23:59:59.000Z

    We measured the ratios of electroproduction cross sections from a proton target for three exclusive meson-baryon final states: ?K+, p?0, and n?+, with the CLAS detector at Jefferson Lab. Using a simple model of quark hadronization, we extract qq¯ creation probabilities for the first time in exclusive two-body production, in which only a single qq¯ pair is created. We observe a sizable suppression of strange quark-antiquark pairs compared to nonstrange pairs, similar to that seen in high-energy production.

  11. Semiclassical suppression of weak anisotropies of a generic Universe

    E-Print Network [OSTI]

    Marco Valerio Battisti; Riccardo Belvedere; Giovanni Montani

    2009-06-11T23:59:59.000Z

    A semiclassical mechanism which suppresses the weak anisotropies of an inhomogeneous cosmological model is developed. In particular, a wave function of this Universe having a meaningful probabilistic interpretation is obtained that is in agreement with the Copenhagen School. It describes the evolution of the anisotropies with respect to the isotropic scale factor which is regarded as a semiclassical variable playing an observer-like role. Near the cosmological singularity the solution spreads over all values of the anisotropies while, when the Universe expands sufficiently, the closed Friedmann-Robertson-Walker model appears to be the favorite state.

  12. Suppression of energetic particle driven instabilities with HHFW heating

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

    Fredrickson, E. D.; Taylor, G.; Bertelli, N.; Darrow, D. S.; Gorelenkov, N.; Kramer, G.; Liu, D.; Crocker, N. A.; Kubota, S.; White, R.

    2015-01-01T23:59:59.000Z

    In plasmas in the National Spherical Torus Experiment (NSTX) [Ono et al., Nucl. Fusion 40 (2000) 557] heated with neutral beams, the beam ions typically excite Energetic Particle Modes (EPMs or fishbones), and Toroidal, Global or Compressional Alfvén Eigenmodes (TAE, GAE, CAE). These modes can redistribute the energetic beam ions, altering the beam driven current profile and the plasma heating profile, or they may affect electron thermal transport or cause losses of the beam ions. In this paper we present experimental results where these instabilities, driven by the super-thermal beam ions, are suppressed with the application of High Harmonic Fastmore »Wave heating.« less

  13. Suppression of soft nuclear bremsstrahlung in proton-nucleus collisions

    E-Print Network [OSTI]

    M. J. van Goethem; L. Aphecetche; J. C. S. Bacelar; H. Delagrange; J. Diaz; D. d'Enterria; M. Hoefman; R. Holzmann; H. Huisman; N. Kalantar--Nayestanaki; A. Kugler; H. Loehner; G. Martinez; J. G. Messchendorp; R. W. Ostendorf; S. Schadmand; R. H. Siemssen; R. S. Simon; Y. Schutz; R. Turrisi; M. Volkerts; H. W. Wilschut

    2001-11-30T23:59:59.000Z

    Photon energy spectra up to the kinematic limit have been measured in 190 MeV proton reactions with light and heavy nuclei to investigate the influence of the multiple-scattering process on the photon production. Relative to the predictions of models based on a quasi-free production mechanism a strong suppression of bremsstrahlung is observed in the low-energy region of the photon spectrum. We attribute this effect to the interference of photon amplitudes due to multiple scattering of nucleons in the nuclear medium.

  14. Suppression of energetic particle driven instabilities with HHFW heating

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

    Fredrickson, E. D. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Taylor, G. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bertelli, N. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Darrow, D. S. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gorelenkov, N. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kramer, G. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Liu, D. [University of California, Irvine, CA (United States); Crocker, N. A. [University of California, Los Angeles (United States); Kubota, S. [University of California, Los Angeles (United States); White, R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2015-01-01T23:59:59.000Z

    In plasmas in the National Spherical Torus Experiment (NSTX) [Ono et al., Nucl. Fusion 40 (2000) 557] heated with neutral beams, the beam ions typically excite Energetic Particle Modes (EPMs or fishbones), and Toroidal, Global or Compressional Alfvén Eigenmodes (TAE, GAE, CAE). These modes can redistribute the energetic beam ions, altering the beam driven current profile and the plasma heating profile, or they may affect electron thermal transport or cause losses of the beam ions. In this paper we present experimental results where these instabilities, driven by the super-thermal beam ions, are suppressed with the application of High Harmonic Fast Wave heating.

  15. Frequency-domain criterion for the speech distortion weighted multichannel Wiener filter for robust noise reduction q

    E-Print Network [OSTI]

    systems. Therefore efficient speech enhancement techniques are called for. Since the desired speech signal and the undesired noise signal usually occupy overlapping frequency bands, sin- gle-microphone speech enhancement and the spatial characteristics of the sources can be used. Well-known multi-microphone speech enhancement

  16. Bursty Impulse Noise Detection by Compressed University of British Columbia, Vancouver, BC, Canada, lampe@ece.ubc.ca

    E-Print Network [OSTI]

    Lampe, Lutz

    wires, no need to purchase spectrum), high penetration of the power distribution grid, and ease of use for data transmission over power lines. For power line communi- cations (PLC) systems with bandwidths application of CS for IN detection. Index Terms--Power line communications (PLC), impulse noise, compressed

  17. The world of quantum noise and the fundamental output process

    E-Print Network [OSTI]

    V. P. Belavkin; O. Hirota; R. Hudson

    2005-10-04T23:59:59.000Z

    A stationary theory of quantum stochastic processes of second order is outlined. It includes KMS processes in wide sense like the equilibrium finite temperature quantum noise given by the Planck's spectral formula. It is shown that for each stationary noise there exists a natural output process output process which is identical to the noise in the infinite temperature limit, and flipping with the noise if the time is reversed at finite temperature. A canonical Hilbert space representation of the quantum noise and the fundamental output process is established and a decomposition of their spectra is found. A brief explanation of quantum stochastic integration with respect to the input-output processes is given using only correlation functions. This provides a mathematical foundation for linear stationary filtering transformations of quantum stochastic processes. It is proved that the colored quantum stationary noise and its time-reversed version can be obtained in the second order theory by a linear nonadapted filtering of the standard vacuum noise uniquely defined by the canonical creation and annihilation operators on the spectrum of the input-output pair.

  18. Noise impact of single-event upsets on an FPGA-based digital filter

    SciTech Connect (OSTI)

    Morgan, Keith S [Los Alamos National Laboratory; Caffrey, Michael P [Los Alamos National Laboratory; Graham, Paul S [Los Alamos National Laboratory; Pratt, Brian H [Los Alamos National Laboratory; Wirthlin, Michael J [BYU

    2009-01-01T23:59:59.000Z

    Field-programmable gate arrays are well-suited to DSP and digital communications applications. SRAM-based FPGAs, however, are susceptible to radiation-induced single-event upsets (SEUs) when deployed in space environments. These effects are often handled with the area and power-intensive TMR mitigation technique. This paper evaluates the effects of SEUs in the FPGA configuration memory as noise in a digital filter, showing that many SEUs in a digital communications system cause effects that could be considered noise rather than circuit failure. Since DSP and digital communications applications are designed to withstand certain types of noise, SEU mitigation techniques that are less costly than TMR may be applicable. This could result in large savings in area and power when implementing a reliable system. Our experiments show that, of the SEUs that affected the digital filter with a 20 dB SNR input signal, less than 14% caused an SNR loss of more than 1 dB at the output.

  19. Hydrodynamical model for $J/?$ suppression and elliptic flow

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2009-10-06T23:59:59.000Z

    In a hydrodynamic model, we have studied $J/\\psi$ suppression and elliptic flow in Au+Au collisions at RHIC energy $\\sqrt{s}$=200 GeV. At the initial time, $J/\\psi$'s are randomly distributed in the fluid. As the fluid evolve in time, the free streaming $J/\\psi$'s are dissolved if the local fluid temperature exceeds a melting temperature $T_{J/\\psi}$. Sequential melting of charmonium states ($\\chi_c$, $\\psi\\prime$ and $J/\\psi$), with melting temperatures $T_{\\chi_c}=T_{\\psi\\prime} \\approx 1.2T_c$, $T_{J/\\psi} \\approx2T_c$ and feed-down fraction $F\\approx 0.3$, is consistent with the PHENIX data on $J/\\psi$ suppression and near zero elliptic flow for $J/\\psi$'s. It is also shown that the model will require substantial regeneration of charmoniums, if the charmonium states dissolve at temperature close to the critical temperature, $T_{\\chi_c}=T_{\\psi\\prime} \\leq T_c$, $T_{J/\\psi}\\approx1.2T_c$. The regenerated charmoniums will have positive elliptic flow.

  20. Enhancement and suppression of opto-acoustic parametric interactions using optical feedback

    SciTech Connect (OSTI)

    Zhang Zhongyang; Zhao Chunnong; Ju, L.; Blair, D. G. [School of Physics, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia)

    2010-01-15T23:59:59.000Z

    A three mode opto-acoustic parametric amplifier (OAPA) is created when two orthogonal optical modes in a high finesse optical cavity are coupled via an acoustic mode of the cavity mirror. Such interactions are predicted to occur in advanced long baseline gravitational wave detectors. They can have high positive gain, which leads to strong parametric instability. Here we show that an optical feedback scheme can enhance or suppress the parametric gain of an OAPA, allowing exploration of three-mode parametric interactions, especially in cavity systems that have insufficient optical power to achieve spontaneous instability. We derive analytical equations and show that optical feedback is capable of controlling predicted instabilities in advanced gravitational wave detectors within a time scale of 13approx10 s.

  1. Investigation of the suppression effect of polyethylene glycol on copper electroplating by electrochemical impedance spectroscopy

    SciTech Connect (OSTI)

    Hung, C.-C.; Lee, W.-H.; Wang, Y.-L.; Chan, D.-Y.; Hwang, G.-J. [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Electrical Engineering, National Chiayi University, Chiayi, Taiwan (China); College of Science and Engineering, National University of Tainan, Tainan 700, Taiwan (China)

    2008-09-15T23:59:59.000Z

    Polyethylene glycol (PEG) is an additive that is commonly used as a suppressor in the semiconductor copper (Cu)-electroplating process. In this study, electrochemical impedance spectroscopy (EIS) was used to analyze the electrochemical behavior of PEG in the Cu-electroplating process. Polarization analysis, cyclic-voltammetry stripping, and cell voltage versus plating time were examined to clarify the suppression behavior of PEG. The equivalent circuit simulated from the EIS data shows that PEG inhibited the Cu-electroplating rate by increasing the charge-transfer resistance as well as the resistance of the adsorption layer. The presence of a large inductance demonstrated the strong adsorption of cuprous-PEG-chloride complexes on the Cu surface during the Cu-electroplating process. Increasing the PEG concentration appears to increase the resistances of charge transfer, the adsorption layer, and the inductance of the electroplating system.

  2. Controlling excess noise in fiber optics continuous variables quantum key distribution

    E-Print Network [OSTI]

    Jérôme Lodewyck; Thierry Debuisschert; Rosa Tualle-Brouri; Philippe Grangier

    2005-12-01T23:59:59.000Z

    We describe a continuous variables coherent states quantum key distribution system working at 1550 nm, and entirely made of standard fiber optics and telecom components, such as integrated-optics modulators, couplers and fast InGaAs photodiodes. The setup is composed of an emitter randomly modulating a coherent state in the complex plane with a doubly Gaussian distribution, and a receiver based on a shot noise limited time-resolved homodyne detector. By using a reverse reconciliation protocol, the device can transfer a raw key rate up to 1 Mb/s, with a proven security against Gaussian or non-Gaussian attacks. The dependence of the secret information rate of the present fiber set-up is studied as a function of the line transmission and excess noise.

  3. All-optical cavity-based simulator of noise-assisted transport

    E-Print Network [OSTI]

    Silvia Viciani; Manuela Lima; Marco Bellini; Filippo Caruso

    2015-04-19T23:59:59.000Z

    Recent theoretical and experimental efforts have shown the remarkable and counter-intuitive role of noise in enhancing the transport efficiency of complex systems. Here, we realize simple, scalable, and controllable optical fiber cavity networks that allow us to simulate the performance of transport networks for different conditions of interference, dephasing and disorder. In particular, we experimentally demonstrate that the transport efficiency reaches a maximum when varying the external dephasing noise, i.e. a bell-like shape behavior that had been predicted only theoretically. These optical platforms are very promising simulators of transport phenomena, and could be used, in particular, to design and test optimal topologies of artificial light-harvesting structures for future solar energy technologies.

  4. All-optical cavity-based simulator of noise-assisted transport

    E-Print Network [OSTI]

    Viciani, Silvia; Bellini, Marco; Caruso, Filippo

    2015-01-01T23:59:59.000Z

    Recent theoretical and experimental efforts have shown the remarkable and counter-intuitive role of noise in enhancing the transport efficiency of complex systems. Here, we realize simple, scalable, and controllable optical fiber cavity networks that allow us to simulate the performance of transport networks for different conditions of interference, dephasing and disorder. In particular, we experimentally demonstrate that the transport efficiency reaches a maximum when varying the external dephasing noise, i.e. a bell-like shape behavior that had been predicted only theoretically. These optical platforms are very promising simulators of transport phenomena, and could be used, in particular, to design and test optimal topologies of artificial light-harvesting structures for future solar energy technologies.

  5. Digital-photonic synthesis of ultra-low noise tunable signals from RF to 100 GHz

    E-Print Network [OSTI]

    Fortier, T M; Quinlan, F; Baynes, F N; Metcalf, A J; Hati, A; Ludlow, A; Hinkley, N; Shimizu, M; Ishibashi, T; Campbell, J C; Diddams, S A

    2015-01-01T23:59:59.000Z

    The demand for higher data rates and better synchronization in communication and navigation systems necessitates the development of new wideband and tunable sources with noise performance exceeding that provided by traditional oscillators and synthesizers. Precision synthesis is paramount for providing frequency references and timing in a broad range of applications including next-generation telecommunications, high precision measurement, and radar and sensing. Here we describe a digital-photonic synthesizer (DPS) based on optical frequency division that enables the generation of widely tunable signals from near DC to 100 GHz with a fractional frequency instability of 1 part in 10^15. The spectral purity of the DPS derived signals represents an improvement in close-to-carrier noise performance over the current state-of-the-art of nearly 7 orders of magnitude in the W-band (100 GHz), and up to 5 orders of magnitude in the X-band (10 GHz).

  6. Experimental study of neutron noise with criticality safety applications in mind

    SciTech Connect (OSTI)

    Barnett, C.S.

    1985-11-01T23:59:59.000Z

    A study has been conducted on the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. Studies were conducted on three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. The noise analysis techniques studied performed well enough in deeply subcritical situations to deserve testing in an applications environment. They have a good chance of detecting changes in reactivity that are potentially dangerous. One can expect sharpest results when doing comparisons, i.e., when comparing two records, one taken in the past under circumstances known to be normal and one taken now to search for change.

  7. Controlling excess noise in fiber-optics continuous-variable quantum key distribution

    SciTech Connect (OSTI)

    Lodewyck, Jerome [Thales Research and Technologies, RD 128 91767 Palaiseau CEDEX (France); Laboratoire Charles Fabry de l'Institut d'Optique, Campus Universitaire, Batiment 503 91403 Orsay CEDEX (France); Debuisschert, Thierry [Thales Research and Technologies, RD 128 91767 Palaiseau CEDEX (France); Tualle-Brouri, Rosa; Grangier, Philippe [Laboratoire Charles Fabry de l'Institut d'Optique, Campus Universitaire, Batiment 503 91403 Orsay CEDEX (France)

    2005-11-15T23:59:59.000Z

    We describe a continuous-variable coherent-states quantum-key distribution system working at 1550 nm, and entirely made of standard fiber optics and telecommunications components, such as integrated-optics modulators, couplers and fast InGaAs photodiodes. The setup is composed of an emitter randomly modulating a coherent state in the complex plane with a doubly Gaussian distribution, and a receiver based on a shot-noise limited time-resolved homodyne detector. By using a reverse reconciliation protocol, the device can transfer a raw key rate up to 1 Mbit/s, with a proven security against Gaussian or non-Gaussian attacks. The dependence of the secret information rate of the present fiber setup is studied as a function of the line transmission and excess noise.

  8. Design and control of noise-induced synchronization patterns

    E-Print Network [OSTI]

    Wataru Kurebayashi; Tsubasa Ishii; Mikio Hasegawa; Hiroya Nakao

    2015-02-17T23:59:59.000Z

    We propose a method for controlling synchronization patterns of limit-cycle oscillators by common noisy inputs, i.e., by utilizing noise-induced synchronization. Various synchronization patterns, including fully synchronized and clustered states, can be realized by using linear filters that generate appropriate common noisy signals from given noise. The optimal linear filter can be determined from the linear phase response property of the oscillators and the power spectrum of the given noise. The validity of the proposed method is confirmed by numerical simulations.

  9. Design and control of noise-induced synchronization patterns

    E-Print Network [OSTI]

    Kurebayashi, Wataru; Hasegawa, Mikio; Nakao, Hiroya

    2015-01-01T23:59:59.000Z

    We propose a method for controlling synchronization patterns of limit-cycle oscillators by common noisy inputs, i.e., by utilizing noise-induced synchronization. Various synchronization patterns, including fully synchronized and clustered states, can be realized by using linear filters that generate appropriate common noisy signals from given noise. The optimal linear filter can be determined from the linear phase response property of the oscillators and the power spectrum of the given noise. The validity of the proposed method is confirmed by numerical simulations.

  10. Semiclassical theory of noise in semiconductor lasers - part 2

    SciTech Connect (OSTI)

    Vahala, K.; Yariv, A.

    1983-06-01T23:59:59.000Z

    A model of semiconductor laser noise is presented which includes the carrier density as a dynamical variable and the carrier density dependence of the refractive index. The Van der Pol laser noise model is shown to be a special case of this treatment. Expressions are calculated for all laser spectra and compared with their Van der Pol counterparts. The power fluctuations spectrum and the frequency fluctuations spectrum exhibit a resonance corresponding to the relaxation resonance and the field spectrum contains fine structure, similar to sidebands which result from harmonic frequency modulation of a carrier signal. The role of carrier noise in determining the field spectrum linewidth is also considered.

  11. Results of r.f. noise coupling tests done in building 141

    SciTech Connect (OSTI)

    Anderson, R A

    1999-12-01T23:59:59.000Z

    As part of the lightning protection plan at the Pantex plant, coupling measurements were made by LLNL to determine the transfer functions of the work areas (cell or bay). From these measured transfer functions the susceptibility of the cell to a lightning strike can be determined, and the appropriate mitigating measures put into effect. The transfer functions are determined by injecting a current on the outside of the cell and measuring the electric field inside. The ratio of electric field to the injected current over a broad frequency range is the transfer function. During one of our tests a comparison of LLNL and SNLA instrumentation was done. The major difference in the systems was that the SNLA system used batteries for power and a fiber optic link to decouple the antenna from the receiver. LLNL used AC power and a cable for the antenna connection. The comparison showed a discrepancy between LLNL and SNLA results. The source of this error was unwanted signal (noise) coupling into the local AC power source from the injected current. Since this source was used to power the equipment, the noise was fed directly to the electric field measuring antenna, causing errors in the measurement. The main source of error was confirmed with a series of lab tests done at LLNL Building 141, using combinations of AC power, battery power, and a fiberoptic link. A noise model was hypothesized and the measured transfer functions were analyzed with the noise model in mind to show how the errors were introduced into the data. Measurements were made to show the decoupling effects of using ferrite cores on the instrumentation power cords. The necessary changes to the LLNL instrumentation was then made to avoid these errors.

  12. A genetically encoded, high-signal-to-noise maltose sensor

    SciTech Connect (OSTI)

    Marvin, Jonathan S.; Schreiter, Eric R.; Echevarría, Ileabett M.; Looger, Loren L. (Puerto Rico); (HHMI)

    2012-10-23T23:59:59.000Z

    We describe the generation of a family of high-signal-to-noise single-wavelength genetically encoded indicators for maltose. This was achieved by insertion of circularly permuted fluorescent proteins into a bacterial periplasmic binding protein (PBP), Escherichia coli maltodextrin-binding protein, resulting in a four-color family of maltose indicators. The sensors were iteratively optimized to have sufficient brightness and maltose-dependent fluorescence increases for imaging, under both one- and two-photon illumination. We demonstrate that maltose affinity of the sensors can be tuned in a fashion largely independent of the fluorescent readout mechanism. Using literature mutations, the binding specificity could be altered to moderate sucrose preference, but with a significant loss of affinity. We use the soluble sensors in individual E. coli bacteria to observe rapid maltose transport across the plasma membrane, and membrane fusion versions of the sensors on mammalian cells to visualize the addition of maltose to extracellular media. The PBP superfamily includes scaffolds specific for a number of analytes whose visualization would be critical to the reverse engineering of complex systems such as neural networks, biosynthetic pathways, and signal transduction cascades. We expect the methodology outlined here to be useful in the development of indicators for many such analytes.

  13. Improving robustness of exoplanetary orbital fits through a regularization of the white and red Doppler noise models. Hints of a 13-year star-spot activity cycle of 55 Cancri

    E-Print Network [OSTI]

    Baluev, Roman V

    2014-01-01T23:59:59.000Z

    We consider the impact of the Doppler noise model on the statistical robustness of the exoplanetary radial-velocity fits. We show that the traditional model of the Doppler noise with an additive jitter can generate large non-linearity effects, decreasing the reliability of the fit, especially in the cases when a correleated Doppler noise is involved. We introduce a regularization of the additive noise model that can gracefully eliminate its singularities together with the associated non-linearity effects. We apply this approach to Doppler time-series data of several exoplanetary systems. It demonstrates that our new regularized noise model yields orbital fits that have either increased or at least the same statistical robustness, in comparison with the simple additive jitter. Various statistical uncertainties in the parametric estimations are often reduced, while planet detection significance is often increased. Concerning the 55 Cnc five-planet system, we show that its Doppler data contain significant correl...

  14. Nuclear absorption and anomalous $J/?$ suppression in Pb+Pb collisions

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2003-07-31T23:59:59.000Z

    We discuss $J/\\psi$ suppression in a QCD based nuclear absorption model. Centrality dependence of $J/\\psi$ suppression in S+U and in Pb+Pb collisions are explained in the model. However, the model fails to explain the centrality dependence of $\\psi\\prime$ suppression. $\\psi\\prime$ suppression in S+U or in Pb+Pb collisions require additional suppression. Additional suppression of $\\psi\\prime$, due to hadronic comovers or due to QGP formation could not be distinguished in Pb+Pb collisions. We then show that the centrality dependence of the ratio, $\\psi\\prime$ over $J/\\psi$, could possibly distinguish two scenario (e.g. QGP or hadronic comover) at RHIC energy.

  15. Signatures of combinatorial regulation in intrinsic biological noise

    E-Print Network [OSTI]

    Dinner, Aaron

    scenarios (molecular analogs of AND and OR logic operations) in simulations that faithfully represent bacterial gene expression. Applications and extensions to other regulatory scenarios are discussed. gene expression | mathematical modeling | noise analysis inference | flow cytometry Transcription factors regulate

  16. Structural thermal noise in gram-scale mirror oscillators

    E-Print Network [OSTI]

    Neben, Abraham Richard

    The thermal noise associated with mechanical dissipation is a ubiquitous limitation to the sensitivity of precision experiments ranging from frequency stabilization to gravitational wave interferometry. We report on the ...

  17. asme noise control: Topics by E-print Network

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

    complex patterns often being able to be defined with the gradient noise functions. PORN is defined by replacing a static offset distance in a general offset with a gradient...

  18. advanced noise control: Topics by E-print Network

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

    complex patterns often being able to be defined with the gradient noise functions. PORN is defined by replacing a static offset distance in a general offset with a gradient...

  19. De-noised coding by lateral interactions Cornelius Weber

    E-Print Network [OSTI]

    Weber, Cornelius

    De-noised coding by lateral interactions Cornelius Weber Brain and Cognitive Science Dept(8):740-745 (1999). [2] C. Weber and K. Obermayer, Emergence of modularity within one sheet of intrinsically active

  20. Mitigating timing noise in ADCs through digital post-processing

    E-Print Network [OSTI]

    Weller, Daniel (Daniel Stuart)

    2008-01-01T23:59:59.000Z

    The accuracy of analog-to-digital converters (ADCs) is greatly affected by the uniformity of the times at which samples of the analog input signal are taken. The error in the sample times, known as jitter, or timing noise, ...

  1. Electronic noise in nanostructures: limitations and sensing applications

    E-Print Network [OSTI]

    Kim, Jong Un

    2007-04-25T23:59:59.000Z

    and their characteristic length is close to acoustical phonon wavelength. Moreover, because nanostructures include significantly fewer charge carriers than microscale structures, electronic noise in nanostructures is enhanced compared to microscale structures. Additionally...

  2. The cost of noise reduction in commercial tilt rotor aircraft

    E-Print Network [OSTI]

    Faulkner, Henry B.

    1974-01-01T23:59:59.000Z

    The relationship between direct operating cost and departure noise annoyance was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various ...

  3. Ambient addition : how to turn urban noise into music

    E-Print Network [OSTI]

    Vawter, Noah (Noah Theodore)

    2006-01-01T23:59:59.000Z

    As human civilization devises ever more powerful machines, living among them may become more difficult. We may find ourselves surrounded by incidentally created sounds and noises which are out of synchronization with our ...

  4. Applications of broad class knowledge for noise robust speech recognition

    E-Print Network [OSTI]

    Sainath, Tara N

    2009-01-01T23:59:59.000Z

    This thesis introduces a novel technique for noise robust speech recognition by first describing a speech signal through a set of broad speech units, and then conducting a more detailed analysis from these broad classes. ...

  5. Start-Up of FEL Oscillator from Shot Noise

    E-Print Network [OSTI]

    Kumar, V.; Krishnagopal, S.; Fawley, W.M.

    2007-01-01T23:59:59.000Z

    of start-up of the CUTE-FEL oscillator from shot noiseof passes required for the FEL to saturate is equivalent toSTART-UP OF FEL OSCILLATOR FROM SHOT NOISE V. Kumar ? , S.

  6. INTRODUCTION TO STATISTICAL NEURODYNAMICS: EFFECTS OF ADDITIVE AND PARAMETRIC NOISE

    E-Print Network [OSTI]

    Milton, John G.

    Department of Neurology Committees on Neurobiology & Computational Neuroscience The University of ChicagoINTRODUCTION TO STATISTICAL NEURODYNAMICS: EFFECTS OF ADDITIVE AND PARAMETRIC NOISE John Milton current first attracted the attention of neurobiologists to the presence of ion channels, or pores

  7. Microjet based noise control of supersonic jets on carrier decks

    E-Print Network [OSTI]

    Ragaller, Paul Aaron

    2014-01-01T23:59:59.000Z

    The effectiveness of ground plane water microjet control on the noise generated by a supersonic, ideally expanded, Mach 1.5, impinging jet was determined. Using a converging-diverging nozzle with a design Mach number of ...

  8. The reduction of supersonic jet noise using pulsed microjet injection

    E-Print Network [OSTI]

    Ragaller, Paul Aaron

    2007-01-01T23:59:59.000Z

    This thesis is concerned with the active control of supersonic jet noise using pulsed microjet injection at the nozzle exit. Experimental investigations were carried out using this control method on an ideally expanded ...

  9. aircraft interior noise: Topics by E-print Network

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

    9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 OPTIMIZATION OF OPERATIONAL AIRCRAFT PARAMETERS REDUCING NOISE EMISSION Mathematics Websites...

  10. Hybrid wing-body aircraft noise and performance assessment

    E-Print Network [OSTI]

    Weed, Philip Andrew

    2010-01-01T23:59:59.000Z

    Hybrid wing-body aircraft noise generation and boundary layer ingestion (BLI) performance trends with increased fan face Mach number inlet designs are investigated. The presented topics are in support of the NASA subsonic ...

  11. A diffraction integral based turbomachinery noise shielding method

    E-Print Network [OSTI]

    Colas, Dorian Frederic Marie

    2011-01-01T23:59:59.000Z

    A current research focus in subsonic aeronautics is the reduction of noise, emissions and fuel burn. The Silent Aircraft Initiative, NASA N+2 and N+3 projects are examples of recent efforts investigating innovative aircraft ...

  12. aircraft noise effects: Topics by E-print Network

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

    of an order of magnitude and the corresponding lifetime of about seven decades. R. Yamapi; G. Filatrella 2014-06-24 93 Effects of noise on quantum error correction algorithms...

  13. anthropogenic noise effects: Topics by E-print Network

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

    of an order of magnitude and the corresponding lifetime of about seven decades. R. Yamapi; G. Filatrella 2014-06-24 90 Effects of noise on quantum error correction algorithms...

  14. 3D Module Placement for Congestion and Power Noise Reduction

    E-Print Network [OSTI]

    Lim, Sung Kyu

    3D Module Placement for Congestion and Power Noise Reduction Jacob R. Minz School of ECE Georgia that copies are not made or distributed for profit or commercial advantage and that copies bear this notice

  15. Active particles in heterogeneous media display new physics: existence of an optimal noise and absence of bands and long-range order

    E-Print Network [OSTI]

    Chepizhko, Oleksandr

    2015-01-01T23:59:59.000Z

    We present a detailed study of the large-scale collective properties of self-propelled particles (SPPs) moving in two-dimensional heterogeneous spaces. The impact of spatial heterogeneities on the ordered, collectively moving phase is investigated. We show that for strong enough spatial heterogeneity, the well-documented high-density, high-ordered propagating bands that emerge in homogeneous space disappears. Moreover, the ordered phase does not exhibit long-range order, as occurs in homogeneous systems, but rather quasi-long range order: i.e. the SPP system becomes disordered in the thermodynamical limit. For finite size systems, we find that there is an optimal noise value that maximizes order. Interestingly, the system becomes disordered in two limits, for high noise values as well as for vanishing noise. This remarkable finding strongly suggests the existence of two critical points, instead of only one, associated to the collective motion transition. Density fluctuations are consistent with these observat...

  16. acid suppresses uv-b-induced: Topics by E-print Network

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

    Topic Index 1 Suppression of rice methane emission by sulfate deposition in simulated acid rain Geosciences Websites Summary: from rice agriculture. Emissions from rice plants...

  17. Study on higher harmonic suppression using edge filter and polished Si wafer

    SciTech Connect (OSTI)

    Gupta, R. K., E-mail: rkg@rrcat.gov.in; Singh, Amol, E-mail: rkg@rrcat.gov.in; Modi, Mohammed H., E-mail: rkg@rrcat.gov.in; Lodha, G. S., E-mail: rkg@rrcat.gov.in [X-ray Optics Section, ISU Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

    2014-04-24T23:59:59.000Z

    Higher harmonics contamination is a severe problem in synchrotron beamlines where grating monochromators are used. In these beamlines, absorption edge filters and critical angle mirrors are used to suppress the harmonic contaminations. In the present study, carried out using Indus-1 reflectivity beamline, a harmonic suppression characteristic of Al edge filter and polished silicon wafer are determined. It is found that the Al filter suppresses higher harmonics in 2–7% range whereas the polished silicon wafer can suppress the higher harmonics below 1%. The results of comparative study are discussed.

  18. Method and apparatus for suppressing waves in a borehole

    DOE Patents [OSTI]

    West, Phillip B.

    2005-10-04T23:59:59.000Z

    Methods and apparatus for suppression of wave energy within a fluid-filled borehole using a low pressure acoustic barrier. In one embodiment, a flexible diaphragm type device is configured as an open bottomed tubular structure for disposition in a borehole to be filled with a gas to create a barrier to wave energy, including tube waves. In another embodiment, an expandable umbrella type device is used to define a chamber in which a gas is disposed. In yet another embodiment, a reverse acting bladder type device is suspended in the borehole. Due to its reverse acting properties, the bladder expands when internal pressure is reduced, and the reverse acting bladder device extends across the borehole to provide a low pressure wave energy barrier.

  19. NoiseTube: Measuring and mapping noise pollution with mobile phones Nicolas Maisonneuve Sony Computer Science Laboratory Paris

    E-Print Network [OSTI]

    TAGora project

    map. Keywords: Noise pollution, citizen science, participatory sensing, people- centric sensing, geo Computer Science Laboratory Paris Matthias Stevens SOFT, Dept. Of Computer Science, Vrije Universiteit Computer Science Laboratory Paris / ARTI, Dept. Of Computer Science, Vrije Universiteit Brussel Published

  20. Classical noise assists the flow of quantum energy by `momentum rejuvenation'

    E-Print Network [OSTI]

    Ying Li; Filippo Caruso; Erik Gauger; Simon C. Benjamin

    2014-06-13T23:59:59.000Z

    An important challenge in quantum science is to fully understand the efficiency of energy flow in networks. Here we present a simple and intuitive explanation for the intriguing observation that optimally efficient networks are not purely quantum, but are assisted by some interaction with a `noisy' classical environment. By considering the system's dynamics in both the site-basis and the momentum-basis, we show that the effect of classical noise is to sustain a broad momentum distribution, countering the depletion of high mobility terms which occurs as energy exits from the network. This picture predicts that the optimal level of classical noise is reciprocally related to the linear dimension of the lattice; our numerical simulations verify this prediction to high accuracy for regular 1D and 2D networks over a range of sizes up to thousands of sites. This insight leads to the discovery that dramatic further improvements in performance occur when a driving field targets noise at the low mobility components.

  1. Blue Noise Sampling with Controlled Aliasing DANIEL HECK and THOMAS SCHL OMER and OLIVER DEUSSEN

    E-Print Network [OSTI]

    Deussen, Oliver

    Blue Noise Sampling with Controlled Aliasing DANIEL HECK and THOMAS SCHL ¨OMER and OLIVER DEUSSEN University of Konstanz In this paper we revisit the problem of blue noise sampling with a strong focus types of blue noise patterns: step blue noise with a power spectrum in the form of a step function

  2. ANALYSIS OF AN MTC NOISE MEASUREMENT PERFORMED IN RINGHALS-2 USING GAMMA-

    E-Print Network [OSTI]

    Demazière, Christophe

    ANALYSIS OF AN MTC NOISE MEASUREMENT PERFORMED IN RINGHALS-2 USING GAMMA- THERMOMETERS AND IN to estimate the MTC by noise analysis, via a new MTC noise estimator. It was shown that whatever the location that the main reason of the MTC underestimation by noise analysis in all the experimental work until now was due

  3. Speech Enhancement based on Smoothing of Spectral Noise HyoungGook Kim, Thomas Sikora

    E-Print Network [OSTI]

    Wichmann, Felix

    Speech Enhancement based on Smoothing of Spectral Noise Floor Hyoung­Gook Kim, Thomas Sikora presents robust speech enhancement using noise estimation based on smoothing of spectral noise floor (SNF for a nonstationary noise. Its enhanced speech is free of musical tones and reverberation artifacts and sounds very

  4. SYNTHESIS How and why environmental noise impacts animals: an integrative, mechanistic review

    E-Print Network [OSTI]

    Swaddle, John

    . Abstract The scope and magnitude of anthropogenic noise pollution are often much greater than those the effects of acoustic stimuli on animal physiology, development, neural function and genetic effects, we are affected by environmental noise. Keywords Anthropogenic noise, fitness, human disturbance, noise pollution

  5. SiGe HBT Nonlinear Phase Noise Modeling Sebastien Gribaldo, Laurent Bary and Olivier Llopis

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    SiGe HBT Nonlinear Phase Noise Modeling S´ebastien Gribaldo, Laurent Bary and Olivier Llopis LAAS model of a SiGe bipolar transistor is presented. This model includes nonlinear noise sources and is able phase noise data at different RF power level. Keywords: nonlinear noise, modelling, SiGe PACS: 85.40.Qx

  6. An efficient modeling method for thermal stratification simulation in a BWR suppression pool

    SciTech Connect (OSTI)

    Haihua Zhao; Ling Zou; Hongbin Zhang; Hua Li; Walter Villanueva; Pavel Kudinov

    2012-09-01T23:59:59.000Z

    The suppression pool in a BWR plant not only is the major heat sink within the containment system, but also provides major emergency cooling water for the reactor core. In several accident scenarios, such as LOCA and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; and the pool temperature distribution also affects the NPSHa (Available Net Positive Suction Head) and therefore the performance of the pump which draws cooling water back to the core. Current safety analysis codes use 0-D lumped parameter methods to calculate the energy and mass balance in the pool and therefore have large uncertainty in prediction of scenarios in which stratification and mixing are important. While 3-D CFD methods can be used to analyze realistic 3D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, therefore long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by 1-D transient partial differential equations and substructures such as free or wall jets are modeled with 1-D integral models. This allows very large reductions in computational effort compared to 3-D CFD modeling. The POOLEX experiments at Finland, which was designed to study phenomena relevant to Nordic design BWR suppression pool including thermal stratification and mixing, are used for validation. GOTHIC lumped parameter models are used to obtain boundary conditions for BMIX++ code and CFD simulations. Comparison between the BMIX++, GOTHIC, and CFD calculations against the POOLEX experimental data is discussed in detail.

  7. Active particles in heterogeneous media display new physics: existence of optimal noise and absence of bands and long-range order

    E-Print Network [OSTI]

    Oleksandr Chepizhko; Fernando Peruani

    2015-03-18T23:59:59.000Z

    We present a detailed study of the large-scale collective properties of self-propelled particles (SPPs) moving in two-dimensional heterogeneous space. The impact of spatial heterogeneities on the ordered, collectively moving phase is investigated. We show that for strong enough spatial heterogeneity, the well-documented high-density, high-ordered propagating bands that emerge in homogeneous space disappear. Moreover, the ordered phase does not exhibit long-range order, as occurs in homogeneous systems, but rather quasi-long range order: i.e. the SPP system becomes disordered in the thermodynamical limit. For finite size systems, we find that there is an optimal noise value that maximizes order. Interestingly, the system becomes disordered in two limits, for high noise values as well as for vanishing noise. This remarkable finding strongly suggests the existence of two critical points, instead of only one, associated to the collective motion transition. Density fluctuations are consistent with these observations, being higher and anomalously strong at the optimal noise, and decreasing and crossing over to normal for high and low noise values. Collective properties are investigated in static as well as dynamic heterogeneous environments, and by changing the symmetry of the velocity alignment mechanism of the SPPs.

  8. Noise correction of turbulent spectra obtained from Acoustic Doppler Velocimeters

    SciTech Connect (OSTI)

    Durgesh, Vibhav; Thomson, Jim; Richmond, Marshall C.; Polagye, Brian

    2014-03-02T23:59:59.000Z

    Accurately estimated auto-spectral density functions are essential for characterization of turbulent flows, and they also have applications in computational fluid dynamics modeling, site and inflow characterization for hydrokinetic turbines, and inflow turbulence generation. The Acoustic Doppler Velocimeter (ADV) provides single-point temporally resolved data, that are used to characterize turbulent flows in rivers, seas, and oceans. However, ADV data are susceptible to contamination from various sources, including instrument noise, which is the intrinsic limit to the accuracy of acoustic velocity measurements. Due to the presence of instrument noise, the spectra obtained are altered at high frequencies. The focus of this study is to develop a robust and effective method for accurately estimating auto-spectral density functions from ADV data by reducing or removing the spectral contribution derived from instrument noise. For this purpose, the “Noise Auto-Correlation” (NAC) approach was developed, which exploits the correlation properties of instrument noise to identify and remove its contribution from spectra. The spectra estimated using the NAC approach exhibit increased fidelity and a slope of -5/3 in the inertial range, which is typically observed for turbulent flows. Finally, this study also compares the effectiveness of low-pass Gaussian filters in removing instrument noise with that of the NAC approach. For the data used in this study, both the NAC and Gaussian filter approaches are observed to be capable of removing instrument noise at higher frequencies from the spectra. However, the NAC results are closer to the expected frequency power of -5/3 in the inertial sub-range.

  9. Study of the doubly and singly Cabibbo suppressed decays D+ --> K+ pi- pi+ and D(s)+ --> K+ pi- pi+ in the FOCUS experiment

    SciTech Connect (OSTI)

    Edera, Laura

    2005-01-01T23:59:59.000Z

    This thesis illustrates a complete study of the doubly and singly Cabibbo suppressed decays D{sup +} and D{sub s}{sup +} {yields} K{sup +} {pi}{sup -}{pi}{sup +}. Data for this analysis have been collected by the fixed-target high-energy photoproduction experiment FOCUS at Fermilab. The authors have selected the D{sup +} and D{sub s}{sup +} samples with cuts to obtain a sufficiently high statistics, a good signal to noise ratio and, at the same time, eliminate possible contaminations from the more copious and favored decays. The D{sup +} yield consists of 189 {+-} 24 events, with a signal to noise ratio {approx} 1; the D{sub s}{sup +} yield is 567 {+-} 31 and the signal to noise ratio is {approx} 2.5. The authors have measured {Lambda}(D{sup +} {yields} K{sup +}{pi}{sup -}{pi}{sup +})/{Lambda}(D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +}) = 0.0065 {+-} 0.0008 {+-} 0.004 and {Lambda}(D{sub s}{sup +} {yields} K{sup +}{pi}{sup -}{pi}{sup +})/{Lambda}(D{sub s}{sup +} {yields} K{sup +}K{sup -}{pi}{sup +}) = 0.127 {+-} 0.007 {+-} 0.014, improving the previous determinations of a factor of 2 and 5, respectively. The author has also performed a Dalitz plot analysis for both decays. The amplitude analysis for D{sub s}{sup +} {yields} K{sup +}{pi}{sup -}{pi}{sup +} represents the first available measurement for this channel.

  10. Flare Noise Reduction Exxon Chemical- Baytown Olefins Plant: 1994 CMA Energy Efficiency Award for "Flare Noise Reduction" in the category of "Public Outreach/Plant Site"

    E-Print Network [OSTI]

    Bradham, S.; Stephan, R.

    frequency noise that resembles the sound of a jet plane passing overhead. To supplement the qualitative data received from the community, quantitative noise data was collected at various flaring conditions, wind conditions, and steam rates. Additional...

  11. Harvesting entropy and quantifying the transition from noise to chaos in a photon-counting feedback loop

    E-Print Network [OSTI]

    Aaron M. Hagerstrom; Thomas E. Murphy; Rajarshi Roy

    2015-03-27T23:59:59.000Z

    Some physical processes, including the intensity fluctuations of a chaotic laser, the detection of single photons, and the Brownian motion of a microscopic particle in a fluid are unpredictable, at least on long timescales. This unpredictability can be due to a variety of physical mechanisms, but it is quantified by an entropy rate. This rate describes how quickly a system produces new and random information, is fundamentally important in statistical mechanics and practically important for random number generation. We experimentally study entropy generation and the emergence of deterministic chaotic dynamics from discrete noise in a system that applies feedback to a weak optical signal at the single-photon level. We show that the dynamics qualitatively change from shot noise to chaos as the photon rate increases, and that the entropy rate can reflect either the deterministic or noisy aspects of the system depending on the sampling rate and resolution.

  12. A major hindrance to rendering spoken dialog systems capable of ongoing, continuous listening without requiring a push-to-

    E-Print Network [OSTI]

    Horvitz, Eric

    , if the system is responding to a request and the user coughs or some other background noise is heard, the system

  13. FRACTAL SHAPED MICROSTRIP COUPLED LINE BAND PASS FILTERS FOR SUPPRESSION OF 2ND

    E-Print Network [OSTI]

    Tentzeris, Manos

    1 FRACTAL SHAPED MICROSTRIP COUPLED LINE BAND PASS FILTERS FOR SUPPRESSION OF 2ND HARMONIC Il Kwon Koch fractal curves are proposed for the first time. These filters are fabricated on Liquid Crystal, the 2nd harmonic of fractal filters can be significantly suppressed through the use of fractal shapes

  14. Precipitation suppression by anthropogenic air pollution: major loss of water resources where we need them most

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    Precipitation suppression by anthropogenic air pollution: major loss of water resources where we inferences of air pollution suppressing precipitation lead us to investigate historical climate records precipitation, decreases with time in the polluted regions and remains unchanged where no pollution sources were

  15. Assessment of compost for suppression of Fusarium Patch (Microdochium nivale) and Typhula Blight

    E-Print Network [OSTI]

    Boland, Greg J.

    Assessment of compost for suppression of Fusarium Patch (Microdochium nivale) and Typhula Blight 2001; accepted 21 May 2002 Abstract Two composts were evaluated for suppression of Fusarium Patch of compost applied at either 48.7 or 97:4kg=100m2 reduced snow mold severity to levels not significantly

  16. Suppressive Drug Interactions between Antifungals Marjon G.J. de Vos1 and Tobias Bollenbach1,*

    E-Print Network [OSTI]

    Bulyk, Martha L.

    Suppressive Drug Interactions between Antifungals Marjon G.J. de Vos1 and Tobias Bollenbach1,* 1IST a systematic study of drug interactions be- tween antifungal compounds. Suppressive drug interactions occur. When two drugs are combined, they may interact synergistically or antago- nistically; for synergistic

  17. Kalispel Non-Native Fish Suppression Project 2007 Annual Report.

    SciTech Connect (OSTI)

    Wingert, Michele; Andersen, Todd [Kalispel Natural Resource Department

    2008-11-18T23:59:59.000Z

    Non-native salmonids are impacting native salmonid populations throughout the Pend Oreille Subbasin. Competition, hybridization, and predation by non-native fish have been identified as primary factors in the decline of some native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi) populations. In 2007, the Kalispel Natural Resource Department (KNRD) initiated the Kalispel Nonnative Fish Suppression Project. The goal of this project is to implement actions to suppress or eradicate non-native fish in areas where native populations are declining or have been extirpated. These projects have previously been identified as critical to recovering native bull trout and westslope cutthroat trout (WCT). Lower Graham Creek was invaded by non-native rainbow (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) after a small dam failed in 1991. By 2003, no genetically pure WCT remained in the lower 700 m of Graham Creek. Further invasion upstream is currently precluded by a relatively short section of steep, cascade-pool stepped channel section that will likely be breached in the near future. In 2008, a fish management structure (barrier) was constructed at the mouth of Graham Creek to preclude further invasion of non-native fish into Graham Creek. The construction of the barrier was preceded by intensive electrofishing in the lower 700 m to remove and relocate all captured fish. Westslope cutthroat trout have recently been extirpated in Cee Cee Ah Creek due to displacement by brook trout. We propose treating Cee Cee Ah Creek with a piscicide to eradicate brook trout. Once eradication is complete, cutthroat trout will be translocated from nearby watersheds. In 2004, the Washington Department of Fish and Wildlife (WDFW) proposed an antimycin treatment within the subbasin; the project encountered significant public opposition and was eventually abandoned. However, over the course of planning this 2004 project, little public involvement or education was conducted prior to the planned implementation. Therefore, in 2007 we implemented an extensive process to provide public education, address public concerns and provide opportunity for public involvement in implementing piscicides and other native fish recovery actions in the subbasin.

  18. Combustion Process in a Spark Ignition Engine: Dynamics and Noise Level Estimation

    E-Print Network [OSTI]

    T. Kaminski; M. Wendeker; K. Urbanowicz; G. Litak

    2003-12-28T23:59:59.000Z

    We analyse the experimental time series of internal pressure in a four cylinder spark ignition engine. In our experiment, performed for different spark advance angles, apart from usual cyclic changes of engine pressure we observed oscillations. These oscillations are with longer time scales ranging from one to several hundred engine cycles depending on engine working conditions. Basing on the pressure time dependence we have calculated the heat released per cycle. Using the time series of heat release to calculate the correlation coarse-grained entropy we estimated the noise level for internal combustion process. Our results show that for a smaller spark advance angle the system is more deterministic.

  19. In plant partial noise enclosures for the mining industry

    SciTech Connect (OSTI)

    Kinevy, P.T.

    1993-10-01T23:59:59.000Z

    The Physical and Toxic Agents Division of the Mine Safety and Health Administration`s Pittsburgh Safety and Health Technology Center has conducted three joint noise control demonstrations at dry milling operations. These demonstrations were conducted on a rod mill, a roller mill, and a ball mill, in order to survey a representative sample of the more commonly utilized types of milling equipment. The noise control concept that was demonstrated involved the construction of partial enclosures surrounding the mills and then adding acoustical materials within the enclosures to absorb the build up of acoustical energy. The results of this work illustrate the feasibility of this concept, the physical principle of creating an acoustical shadow, and the ability to closely predict the amount of absorptive material required to reduce the noise levels so as to comply with the Code of Federal Regulations (CFR), Title 30.

  20. Lévy Ratchet in a Weak Noise Limit: Theory and Simulation

    E-Print Network [OSTI]

    Ilya Pavlyukevich; Bartlomiej Dybiec; Aleksei V. Chechkin; Igor M. Sokolov

    2010-08-25T23:59:59.000Z

    We study the motion of a particle embedded in a time independent periodic potential with broken mirror symmetry and subjected to a L\\'evy noise possessing L\\'evy stable probability law (L\\'evy ratchet). We develop analytical approach to the problem based on the asymptotic probabilistic method of decomposition proposed by P. Imkeller and I. Pavlyukevich [J. Phys. A {\\bf39}, L237 (2006); Stoch. Proc. Appl. {\\bf116}, 611 (2006)]. We derive analytical expressions for the quantities characterizing the particle motion, namely the splitting probabilities of first escape from a single well, the transition probabilities and the particle current. A particular attention is devoted to the interplay between the asymmetry of the ratchet potential and the asymmetry (skewness) of the L\\'evy noise. Intensive numerical simulations demonstrate a good agreement with the analytical predictions for sufficiently small intensities of the L\\'evy noise driving the particle.