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Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Noise suppressing capillary separation system  

DOE Patents (OSTI)

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.

Yeung, E.S.; Xue, Y.

1996-07-30T23:59:59.000Z

2

A Model of the Lateral Geniculate Complex of the Turtle Visual System: Noise Suppression and Target Motion Detection  

E-Print Network (OSTI)

A Model of the Lateral Geniculate Complex of the Turtle Visual System: Noise Suppression and Target . . . . . . . . . . . . . . . 16 2.4.1 Modeling the Retina of Freshwater Turtles . . . . . . . . . 17 2.4.2 A Freshwater Turtle Visual Cortex Model . . . . . . . . . . 21 2.4.3 Investigating the Turtle Lateral Geniculate Complex

Ghosh, Bijoy K.

3

Explosion suppression system  

DOE Patents (OSTI)

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.

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

1992-01-01T23:59:59.000Z

4

Suppression of Rayleigh-scattering-induced noise in OEOs  

E-Print Network (OSTI)

. Docherty, and C. R. Menyuk, "Fiber-induced degradation in RF-over-fiber links," in Proceedings of IEEE) are hybrid RF-photonic devices that promise to be environmentally robust high-frequency RF sources with very noise in in RF-photonic systems," in Proceedings of IEEE Conference on Frequency Control (Institute

Maryland, Baltimore County, University of

5

Noise of cleanroom recirculation systems  

Science Journals Connector (OSTI)

Recirculation air systems are used by the microelectronics industry as the primary source of unidirectional air flow in cleanrooms. The commonly used recirculation systems include: (1) packaged air handlers which include centrifugal or plug (plenum) fans generally located at fan deck level above the cleanroom; (2) fan?tower recirculation systems consisting most often of vertically mounted vaneaxial fans arranged along the cleanroom perimeter; (3) individual fan?filter units in which the HEPA or ULPA filters are combined with small direct drive blowers supported by the ceiling suspension system; and (4) minienvironments which create superclean conditions around individual tools within a less clean ‘‘ballroom.’’ In this paper the commonly used recirculation systems will be described typical sound power levels and spectrum characteristics of the systems will be presented the natural noise attenuation along the air flow paths will be listed the theoretical models for predicting noise levels in a cleanroom will be introduced and noise mitigation means which can be integrated into different systems will be discussed. Also presented will be the typical noise levels measured in operating cleanrooms.

Mei Q. Wu; Colin G. Gordon

1998-01-01T23:59:59.000Z

6

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

E-Print Network (OSTI)

. Fisch Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 and Department of AstrophysicalNoise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump A Science, Princeton University, Princeton, New Jersey 08543 V. M. Malkin Department of Astrophysical

7

Scanning probe microscopy with inherent disturbance suppression using micromechanical systems  

E-Print Network (OSTI)

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 ...

Sparks, Andrew William, 1977-

2005-01-01T23:59:59.000Z

8

Active noise canceling system for mechanically cooled germanium radiation detectors  

DOE Patents (OSTI)

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.

Nelson, Karl Einar; Burks, Morgan T

2014-04-22T23:59:59.000Z

9

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

NLE Websites -- All DOE Office Websites (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...

10

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

NLE Websites -- All DOE Office Websites (Extended Search)

PPPL extends system for suppressing instabilities to long-pulse experiments on KSTAR By John Greenwald March 18, 2014 Tweet Widget Google Plus One Share on Facebook A look into the...

11

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

NLE Websites -- All DOE Office Websites (Extended Search)

PPPL extends system for suppressing instabilities to long-pulse experiments on KSTAR By John Greenwald March 19, 2014 Tweet Widget Google Plus One Share on Facebook A look into the...

12

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

NLE Websites -- All DOE Office Websites (Extended Search)

Primary tabs View(active tab) High Resolution News PPPL extends system for suppressing instabilities to long-pulse experiments on KSTAR By John Greenwald March 18, 2014 Tweet...

13

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

NLE Websites -- All DOE Office Websites (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...

14

Noise Suppression using a Perceptual Model for Wideband Speech Signals Joachim Thiemann  

E-Print Network (OSTI)

is derived from a method devel- oped by Soulodre [2] to remove camera noise from film soundtracks. Soulodre[n, p] (where p denotes the frame counter) is windowed by a window obtained from the square root of the Hann window, defined by h[n] = 1 2 1 - cos 2 n + 0.5 NF , (1) where n = 0, . . . , NF - 1. The f

Kabal, Peter

15

White noise distribution theory for the Fermion system  

E-Print Network (OSTI)

In this paper, we give the white noise calculus for the Fermion system and prove the Fock expansion. Each continuous linear operator on Fermionic white noise functionals is uniquely represented by the series of integral kernel operators. This series is called the Fock expansion.

Yoshihito Shimada

2005-12-09T23:59:59.000Z

16

Environmental Noise and Nonlinear Relaxation in Biological Systems  

E-Print Network (OSTI)

We analyse the effects of environmental noise in three different biological systems: (i) mating behaviour of individuals of \\emph{Nezara viridula} (L.) (Heteroptera Pentatomidae); (ii) polymer translocation in crowded solution; (iii) an ecosystem described by a Verhulst model with a multiplicative L\\'{e}vy noise.

B. Spagnolo; D. Valenti; S. Spezia; L. Curcio; N. Pizzolato; A. A. Dubkov; A. Fiasconaro; D. Persano Adorno; P. Lo Bue; E. Peri; S. Colazza

2011-10-18T23:59:59.000Z

17

Justification to remove 333 Building fire suppression system  

SciTech Connect

Justification to remove the 333 Building fire suppression system is provided. The Maximum Possible Fire Loss (MPFL) is provided (approximately $800K), potential radiological and toxicological impacts from a postulated fire are discussed, Life Safety Code issues are addressed, and coordination with the Hanford Fire Department is assured.

Benecke, M.W.

1995-12-04T23:59:59.000Z

18

Reactor noise analysis applications in NPP I and C systems  

SciTech Connect

Reactor noise analysis techniques are used in many NPPs on a routine basis as 'inspection tools' to get information on the dynamics of reactor processes and their instrumentation in a passive, non-intrusive way. The paper discusses some of the tasks and requirements an NPP has to take to implement and to use the full advantages of reactor noise analysis techniques. Typical signal noise analysis applications developed for the monitoring of the reactor shutdown system and control system instrumentation of the Candu units of Ontario Power Generation and Bruce Power are also presented. (authors)

Gloeckler, O. [International Atomic Energy Agency, Wagramer Strosse 5, A-1400 Vienna, Austria Ontario Power Generation, 230 Westney Road South, Ajax, Ont. L1S 7R3 (Canada)

2006-07-01T23:59:59.000Z

19

MARS MAGNETIC DATA: THE IMPACT OF NOISE ON THE VERTICAL EXTRAPOLATION OF FIELDS AND METHODS OF SUPPRESSION. Donna M. Jurdy, Michael Stefanick, Department of Geological Sciences,  

E-Print Network (OSTI)

MARS MAGNETIC DATA: THE IMPACT OF NOISE ON THE VERTICAL EXTRAPOLATION OF FIELDS AND METHODS OF SUPPRESSION. Donna M. Jurdy, Michael Stefanick, Department of Geological Sciences, Northwestern University strongly magnetized crust; despite Mars' weak field at present, the intensity reaches about 10 times

Jurdy, Donna M.

20

Testing for Chaos in Deterministic Systems with Noise  

E-Print Network (OSTI)

Testing for Chaos in Deterministic Systems with Noise Georg A. Gottwald School of Maths and Stats Guildford GU2 7XH, UK 24 November, 2004 Abstract Recently, we introduced a new test for distinguishing regular from chaotic dynamics in deterministic dynamical systems and argued that the test had cer- tain

Gottwald, Georg A.

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Control of Noise in Power Station Cooling Tower Systems  

Science Journals Connector (OSTI)

Power?station cooling tower systems must handle large volumes of water and air with large potential energy in the water flows and the requirement for large fans. To minimize the noise generated at power station sites use is made of efficient tower fill materials dual low?speed fans (which shifts the spectrum and lowers mid?frequency noise level) and barrier effects in tower location and orientation. Conventional noise control measures such as mufflers are avoided because of the required increase in pressure across the fan and the high initial cost for quieting large towers. The use of natural draft towers is discussed and it is shown that although the low?frequency noise may be reduced the noise levels at typical property line locations are of the same order of magnitude as that for conventional mechanical cooling towers. Since cooling towers at power stations are required as an environmental (thermal) pollution control measure a trade?off between temperature rise of local water supplies versus increases in community noise becomes a critical factor.

Lewis S. Goodfriend

1973-01-01T23:59:59.000Z

22

Noise Reduction and Design Methodology in Mixed-Signal Systems with Alternating Impedance Electromagnetic Bandgap (AI-EBG)  

E-Print Network (OSTI)

integrity as well as electromagnetic interference (EMI). In this paper, excellent noise suppression with AI, electromagnetic interference. I. INTRODUCTION The integration of wireless technologies in handset and mobile

Swaminathan, Madhavan

23

Cold Boot Key Recovery by Solving Polynomial Systems with Noise  

E-Print Network (OSTI)

Cold Boot Key Recovery by Solving Polynomial Systems with Noise Martin Albrecht and Carlos Cid 1 proposed in [9]; the technique was called Cold Boot attacks. When considering block ciphers Cold Boot attacks, was proposed in [9] and also provided an insight into the strength of a particular

Sheldon, Nathan D.

24

Enabling Green Energy and Propulsion Systems via Direct Noise Computation |  

NLE Websites -- All DOE Office Websites (Extended Search)

High-fidelity simulation of exhaust nozzle under installed configuration High-fidelity simulation of exhaust nozzle under installed configuration 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 Email: paliath@ge.com Institution: GE Global Research Allocation Program: INCITE Allocation Hours at ALCF: 105 Million Year: 2013 Research Domain: Engineering GE Global Research is using the Argonne Leadership Computing Facility (ALCF) to deliver significant improvements in efficiency, (renewable's) yield and lower emissions (noise) for advanced energy and propulsion systems. Understanding the fundamental physics of turbulent mixing has the potential to transform product design for components such as airfoils and

25

Flow Noise Prediction and Control in Steam Piping Systems for Nuclear Power Plants  

Science Journals Connector (OSTI)

The flow noise of steam in pipe lines particularly in power plants is a major noise source and contributor to OSHA noise problems. The ability to predict flow noise levels is vital to efficient and economical noise control. Octave?band measurements of flow noise in the main steam piping system of a nuclear power plant were made. To determine the effect of velocity measurements were conducted for a wide range of velocities during plant start?up. Results in the form of plots of measured flow noise as a function of velocity were compared with limited data that have been recently published. An empirical formula for prediction of flow noise and corresponding design techniques for control of noise by proper pipe sizing have been developed. Alternate methods of noise control are reviewed.

F. H. Brittain; S. W. Giampapa

1973-01-01T23:59:59.000Z

26

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

E-Print Network (OSTI)

and vibration control systems Noise and vibration are often limiting factors in performance of many industrial be of little use at lower frequencies. Active noise and vibration control (ANVC) systems have emerged as viable-dimensional enclosure. One of the panels of the enclosure is vibrated, hence generating acoustic noise inside

Pota, Himanshu Roy

27

11 - Noise, vibration, and harshness (NVH) in diesel engine system design  

Science Journals Connector (OSTI)

Abstract: This chapter addresses NVH characteristics in diesel engine system design. By focusing on engine noise – a critical performance attribute for engine competitiveness, this chapter provides a comprehensive coverage of the NVH issues that a system engineer can evaluate by using engine system design/analysis tools. The chapter starts by introducing the fundamental principles of powertrain and diesel engine NVH, and establishes a three-level system modeling approach to engine noise. It summarizes the noise characteristics and noise-reduction design measures for both the overall engine and individual subsystems such as the noises from combustion, piston slap, valvetrain, geartrain, cranktrain, auxiliary, and aerodynamic sources.

Qianfan Xin

2013-01-01T23:59:59.000Z

28

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

E-Print Network (OSTI)

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.

Yong Xu; Xiaoqin Jin; Huiqing Zhang; Tingting Yang

2013-09-04T23:59:59.000Z

29

Suppression of intensity noise of a laser-diode-pumped single-frequency Nd:YVO4 laser by optoelectronic control  

E-Print Network (OSTI)

by optoelectronic control Jing Zhang, Hongliang Ma, Changde Xie, and Kunchi Peng The intensity-noise reduction of a laser-diode-pumped single-frequency ring Nd:YVO4 laser when differ- ent optoelectronic control systems techniques, optoelectronic feedback control of the drive current of the pump laser diode and feed

Zhang, Jing

30

Coherence resonance in a chemical excitable system driven by coloured noise  

Science Journals Connector (OSTI)

...Macau, Celso Grebogi and Jurgen Kurths Coherence resonance in a chemical excitable system...driven by external noise affects the coherence of the system's response. The coupling...scale of the system. excitable media|coherence resonance|coloured noise| 1. Introduction...

2008-01-01T23:59:59.000Z

31

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

DOE Patents (OSTI)

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.

Bayramian, Andrew James (Manteca, CA)

2012-07-31T23:59:59.000Z

32

Issues in heat recovery steam generator system noise  

Science Journals Connector (OSTI)

A heat recovery steam generator (HRSG) is a fundamental component of all combustion turbine?based combined cycle power plants. While it’s primary purpose is to convert exhaust gas heat to steam an important secondary function is to reduce noise emissions from the combustion turbine exhaust. This source at about 155 dB (overall) re: 1 pW for a 100?MW turbine is the highest noise emission source in any combustion turbine plant. Therefore the residual exhaust noise emissions leaving the HRSG walls and stack exit must be predicted with acceptable accuracy to determine the total plant noise level. The sources involved in this prediction methodology will be discussed. The issues include source power levels wall and duct transmission loss and the noise reduction characteristics through the HRSG flow path. Special measurement techniques required to quantify HRSG noise emissions are described. Whereas the HRSG is mainly a passive device that attenuates combustion turbine exhaust noise two HRSG generated sources steam venting and supplemental duct firing will also be discussed. [See NOISE?CON Proceedings for full paper.

George F. Hessler Jr.

1997-01-01T23:59:59.000Z

33

Overcoming correlated noise in quantum systems: How mediocre clocks make good qubits  

E-Print Network (OSTI)

A precise measurement of dephasing over a range of timescales is critical for improving quantum gates beyond the error correction threshold. We present a method for measuring dephasing in experimental quantum systems based on randomized benchmarking that excels at measuring small levels of phase noise at the timescales relevant to gates. We find our SQUID-based qubit is not limited by 1/f flux noise, but instead observe a previously unreported telegraph noise mechanism. We demonstrate that full understanding of dephasing allows for the use of "mediocre clocks"--systems with correlated phase noise--as good qubits.

P. J. J. O'Malley; J. Kelly; R. Barends; B. Campbell; Y. Chen; Z. Chen; B. Chiaro; A. Dunsworth; A. G. Fowler; I. -C. Hoi; E. Jeffrey; A. Megrant; J. Mutus; C. Neill; C. Quintana; P. Roushan; D. Sank; A. Vainsencher; J. Wenner; T. C. White; A. N. Korotkov; A. N. Cleland; John M. Martinis

2014-11-10T23:59:59.000Z

34

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

DOE Patents (OSTI)

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.

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

1993-01-01T23:59:59.000Z

35

Acoustical criteria in a two?parameter system for evaluating impact noise insulation.  

Science Journals Connector (OSTI)

Experience indicates that impact noise complaints in multi?family joist?framed buildings fall into two broad classes: low frequency thudding from footfalls and mid? to high frequency noise from heel clicks dragging furniture etc. The authors have developed a two?parameter system for evaluating impact noise [LoVerde and Dong J. Acoust. Soc. Am. 119 3220 (2006); 120 3206 (2006); 122 2954 (2007)] that offers considerable improvement over existing metrics (such as FIIC) in terms of both correlation with subjective reaction and comparison of materials intended for improving impact insulation. Based on this system suggested criteria for impact noise levels are presented. The effects of various design parameters on noise levels are discussed.

2009-01-01T23:59:59.000Z

36

Optimized pulse sequences for suppressing unwanted transitions in quantum systems  

SciTech Connect

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.

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

37

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

DOE Patents (OSTI)

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.

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

38

A hybrid passive/active system for control of the noise radiated by a small generator  

Science Journals Connector (OSTI)

The aim of this work was the design and implementation of a hybrid passive/active system to control the noise radiated by a small generator. The fundamental frequency of the periodic radiated noise depends on the electrical load plugged into the generator. Passive control is afforded by a rectangular enclosure with dimensions 1000×710×530?mm3. The wall panels of the enclosure (steel 1.5 mm thick) are lined with a 30?mm layer of sound absorbing material. Special attention is paid to technical aspects such as air refreshing and temperature inside the enclosure. The measured insertion loss is higher than 20 dB above 500 Hz. Low?frequency noise escapes the enclosure via intake and exhaust openings. Active control is applied to the exhaust noise. The reference signal is supplied by an accelerometer over the air filter case of the generator. A high?temperature loudspeaker is used as control source. The error signal is picked up by a cheap electric microphone. Since noise along the exhaust is too loud the microphone sensitivity had to be reduced by taping its diaphragm. A commercial system is used to implement active noise control. [Work supported by CICYT Project AMB97?1175?C03?01.

Maria Cuesta; Pedro Cobo

1999-01-01T23:59:59.000Z

39

Bounds on the map threshold of iterative decoding systems with erasure noise  

E-Print Network (OSTI)

BOUNDS ON THE MAP THRESHOLD OF ITERATIVE DECODING SYSTEMS WITH ERASURE NOISE A Thesis by CHIA-WEN WANG Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE... August 2008 Major Subject: Electrical Engineering BOUNDS ON THE MAP THRESHOLD OF ITERATIVE DECODING SYSTEMS WITH ERASURE NOISE A Thesis by CHIA-WEN WANG Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment...

Wang, Chia-Wen

2008-10-10T23:59:59.000Z

40

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

E-Print Network (OSTI)

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... for the degree oi' MASTER OP SCIENCE August 1957 Major Sub]eot'f Eleotrioal Engineering A PROPOSED SYSTEM TO AUTOMATICALLY CONTROL AUDIO SOUND-TO-NOISE LEVELS k Thesis QARY S. NEINAST Approved as to style and content by& islay a FBNR o 0 ee e epsx' ne...

Neinast, Gary Strickland

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

DOE Patents (OSTI)

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.

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

42

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

E-Print Network (OSTI)

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

Boyer, Edmond

43

Signal processing method and system for noise removal and signal extraction  

DOE Patents (OSTI)

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.

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

2009-04-14T23:59:59.000Z

44

Toxicant-disease-environment interactions associated with suppression of immune system, growth, and reproduction. [PCB  

SciTech Connect

The effects of marginal malnourishment, infections, and environmental chemicals on growth and reproductive success in Swiss-Webster white mice and wild deer mice were studied with fractional factorial designs. Interaction effects were discovered. For example, malnourished mice were more sensitive to virus exposure and environmental chemicals (a plant growth regulator or polychlorinated biphenyls). Since several commercial plant growth regulators also appear to suppress the immune system, these results cast doubt on the adequacy of current toxicity testing procedures in which factors are studied individually and not in combination.

Porter, W.P.; Hinsdill, R.; Fairbrother, A.; Olson, L.J.; Jaeger, J.; Yuill, T.; Bisgaard, S.; Hunter, W.G.; Nolan, K.

1984-06-01T23:59:59.000Z

45

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

SciTech Connect

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.

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

46

The emission of electromagnetic radiation from a quantum system interacting with an external noise: A general result  

E-Print Network (OSTI)

We compute the spectrum of emitted radiation by a generic quantum system interacting with an external classic noise. Our motivation is to understand this phenomenon within the framework of collapse models. However the computation is general and applies practically to any situation where a quantum system interacts with a noise. The computation is carried out at a perturbative level. This poses problems concerning the correct way of performing the analysis, as repeatedly discussed in the literature. We will clarify also this issue.

S. Donadi; A. Bassi

2014-08-12T23:59:59.000Z

47

Noise thresholds for higher-dimensional systems using the discrete Wigner function  

SciTech Connect

For a quantum computer acting on d-dimensional systems, we analyze the computational power of circuits wherein stabilizer operations are perfect, and we allow access to imperfect nonstabilizer states or operations. If the noise rate affecting the nonstabilizer resource is sufficiently high, then these states and operations can become simulable in the sense of the Gottesman-Knill theorem, reducing the overall power of the circuit to no better than classical. In this paper we find the depolarizing noise rate at which this happens and consequently the most robust nonstabilizer states and non-Clifford gates. In doing so, we make use of the discrete Wigner function and derive facets of the so-called qudit Clifford polytope, i.e., the inequalities defining the convex hull of all qudit Clifford gates. Our results for robust states are provably optimal. For robust gates we find a critical noise rate that, as dimension increases, rapidly approaches the the theoretical optimum of 100%. Some connections with the question of qudit magic state distillation are discussed.

Dam, Wim van; Howard, Mark [Department of Computer Science and Department of Physics, University of California, Santa Barbara, California 93106 (United States); Department of Physics, University of California, Santa Barbara, California 93106 (United States)

2011-03-15T23:59:59.000Z

48

Multivent effects in a large scale boiling water reactor pressure suppression system  

SciTech Connect

The steam-driven GKSS pressure suppression test facility, which contains 3 full scale vent pipes, has been used for 5 years to investigate the postulated loss-of-coolant accident in a Mark II and Type 69 boiling water reactor. Using the results from several of these tests, wetwell boundary load data (peak pressures and spectral power) during the chugging stage, have been evaluated for sparse pool response (one and two vents in the three vent pool) and for full pool response (one, two, or three vent operation in pools of constant wetwell pool area per vent). The sparse pool results indicate the pool-system, chug event boundary loads are strongly dependent on wetwell pool area per vent, with the load increasing with decreasing area. The full pool results show a substantial increase in the pool-system, chug event boundary loads upon a change from single cell to double cell operation; only minor change occurs in going from double to triple cell operation.

McCauley, E.W.; Aust, E.; Schwan, H.

1984-07-06T23:59:59.000Z

49

Review of the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System, January 2012  

NLE Websites -- All DOE Office Websites (Extended Search)

the the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

50

Review of the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System, January 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

the the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

51

Review of the Los Alamos National Laboratory Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System, January 2012  

NLE Websites -- All DOE Office Websites (Extended Search)

Waste Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

52

Review of the Los Alamos National Laboratory Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System, January 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Waste Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

53

Independent Oversight Review of the Technical Area 55 Safety Class Fire Suppression System at Los Alamos National Laboratory, December 2013  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Technical Area 55 Technical Area 55 Safety Class Fire Suppression System at Los Alamos National Laboratory December 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose .................................................................................................................................................... 1 2.0 Background ............................................................................................................................................. 1 3.0 Scope ....................................................................................................................................................... 2

54

Green-Kubo formula for weakly coupled system with dynamical noise  

E-Print Network (OSTI)

We study the Green-Kubo (GK) formula $\\kappa (\\varepsilon, \\xi)$ for the heat conductivity of an infinite chain of $d$-dimensional finite systems (cells) coupled by a smooth nearest neighbour potential $\\varepsilon V$. The uncoupled systems evolve according to Hamiltonian dynamics perturbed stochastically by an energy conserving noise of strength $\\xi$. Noting that $\\kappa (\\varepsilon, \\xi)$ exists and is finite whenever $\\xi> 0$, we are interested in what happens when the strength of the noise $\\xi \\to 0$. For this, we start in this work by formally expanding $\\kappa (\\varepsilon, \\xi)$ in a power series in $\\varepsilon$, $\\kappa (\\varepsilon, \\xi) = \\varepsilon^2 \\sum_{n\\ge 2} \\varepsilon^{n-2} \\kappa_n (\\xi)$ and investigating the (formal) equations satisfied by $\\kappa_n (\\xi$. We show in particular that $\\kappa_2 (\\xi)$ is well defined when no pinning potential is present, and coincides formally with the heat conductivity obtained in the weak coupling (van Hove) limit, where time is rescaled as $\\varepsilon^{-2}t$, for the cases where the latter has been established \\cite{LO, DL}. For one-dimensional systems, we investigate $\\kappa_2 (\\xi)$ as $\\xi\\to 0$ in three cases: the disordered harmonic chain, the rotor chain and a chain of strongly anharmonic oscillators. Moreover, we formally identify $\\kappa_2 (\\xi)$ with the conductivity obtained by having the chain between two reservoirs at temperature $T$ and $T+\\delta T$, in the limit $\\delta T\\to 0$, $N \\to \\infty$, $\\varepsilon \\to 0$.

Cedric Bernardin; Francois Huveneers; Joel L. Lebowitz; Carlangelo Liverani; Stefano Olla

2014-07-15T23:59:59.000Z

55

Development and testing of neutron pulse time stamping data acquisition system for neutron noise experiment  

Science Journals Connector (OSTI)

Abstract Statistical correlation techniques find applications in the analysis of zero power reactor noise and in passive neutron assay (PNA). A large number of apparently different techniques have been in use in these application areas and traditionally the electronics modules used for data acquisition and analysis is specific to the method used. In this paper we describe a data acquisition scheme developed by us, which is independent of the specific analysis method and can therefore be used for all of them. This is a neutron time stamping data acquisition system based on a timer card and an interface software to acquire and store the data in the required format. The system has been successfully tested with two statistically different types of neutron sources, namely a random Poisson source (Pu–Be) and a correlated source (a nuclear reactor).

Rajeev Kumar; M Yakub Ali; S.B. Degweker; S.C. Vishwasrao; R.T. Jadhav

2015-01-01T23:59:59.000Z

56

Engineered Decoherence: Characterization and Suppression  

E-Print Network (OSTI)

Due to omnipresent environmental interferences, quantum coherences inevitably undergo irreversible transformations over certain time-scales, thus leading to the loss of encoded information. This process, known as decoherence, has been a major obstacle in realizing efficient quantum information processors. Understanding the mechanism of decoherence is crucial in developing tools to inhibit it. Here we utilize a method proposed by Cory and co-workers [Phys. Rev. A 67, 062316 (2003)] to engineer artificial decoherence in the system qubits by randomly perturbing their surrounding ancilla qubits. Using a two qubit nuclear magnetic resonance quantum register, we characterize the artificial decoherence by noise spectroscopy and quantum process tomography. Further, we study the efficacy of dynamical decoupling sequences in suppressing the artificial decoherence. Here we describe the experimental results and their comparisons with theoretical simulations.

Swathi S. Hegde; T. S. Mahesh

2014-03-21T23:59:59.000Z

57

The Effect of Bandpass Filters for Thermal Asperity Suppression in Perpendicular Recording Systems  

E-Print Network (OSTI)

results in a sector read failure. As the recording density keeps increasing and as the flying height keeps decreasing, the TA effect becomes even more serious in future disk drives. Consequently, a method to suppress for next generation disk drives. Most of TA detection and correction algorithms proposed in the literature

Kovintavewat, Piya

58

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

DOE Patents (OSTI)

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.

Rosenberg, Louis B. (Pleasanton, CA)

1998-01-01T23:59:59.000Z

59

Underwater Noise Radiation Due to Transmission through the Cooling Water System of a Marine Diesel Engine  

Science Journals Connector (OSTI)

Diesel engines fitted in modern surface ships are nowadays frequently subject to thorough treatment for the control of noise radiated underwater. That treatment increasingly extends beyond the primary measures...

M. Purshouse

1986-01-01T23:59:59.000Z

60

Study of Collective Interaction Control over e-beam Current Noise  

NLE Websites -- All DOE Office Websites (Extended Search)

noise below the text- book shot-noise level (eI b )? *Is it possible to enhance the coherence of X-UV FELs by suppressing the input noise? *What are the fundamental limits of FEL...

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Combustion Noise  

E-Print Network (OSTI)

stabilize or destabilize the modes of the system, depending on the configuration of the combustor and the form of the coupling [26, 30]. In contrast to combustion instability, in broad-band combustion noise the unsteadiness in the rate of combustion... from th s in a mod on tempera , entropic a de of indir t frequenci r, open que sical theory assical expe s [14] who it by a spa d a transie le gases. A e bubble si idered as a flame was ent was o ng and dif depended udy it wa ion, ? ?,p r t? : (a...

Dowling, Ann P.; Mahmoudi, Yasser

2014-01-01T23:59:59.000Z

62

Interplay of time-delayed feedback control and temporally correlated noise in excitable systems  

Science Journals Connector (OSTI)

...C. W. 2002 Handbook of stochastic methods for physics, chemistry and...Scientific Conf. on Physics and Control...noise-induced dynamicsIn Handbook of chaos controlE...processes in physics, chemistry and...Schuster2008 Handbook of chaos controlsecond...

2010-01-01T23:59:59.000Z

63

Scaling and Suppression of Anomalous Heating in Ion Traps L. Deslauriers, S. Olmschenk, D. Stick, W. K. Hensinger, J. Sterk, and C. Monroe*  

E-Print Network (OSTI)

information algorithms [8]. An important source of decoherence in these systems has proven to be the heating be related to parasitic electrical noise observed in many condensed-matter quantum systems [13Scaling and Suppression of Anomalous Heating in Ion Traps L. Deslauriers, S. Olmschenk, D. Stick, W

Hensinger, Winfried

64

Role of the interpretation of stochastic calculus in systems with cross-correlated Gaussian white noises  

Science Journals Connector (OSTI)

We derive the Fokker-Planck equation for multivariable Langevin equations with cross-correlated Gaussian white noises for an arbitrary interpretation of the stochastic differential equation. We formulate the conditions when the solution of the Fokker-Planck equation does not depend on which stochastic calculus is adopted. Further, we derive an equivalent multivariable Ito stochastic differential equation for each possible interpretation of the multivariable Langevin equation. To demonstrate the usefulness and significance of these general results, we consider the motion of Brownian particles. We study in detail the stability conditions for harmonic oscillators with two white noises, one of which is additive, random forcing, and the other, which accounts for fluctuations of either the damping or the spring coefficient, is multiplicative. We analyze the role of cross correlation in terms of the different noise interpretations and confirm the theoretical predictions via numerical simulations. We stress the interest of our results for numerical simulations of stochastic differential equations with an arbitrary interpretation of the stochastic integrals.

Vicenç Méndez; S. I. Denisov; Daniel Campos; Werner Horsthemke

2014-07-18T23:59:59.000Z

65

Minimizing manganin/system noise for potential use in small geometry experiments  

SciTech Connect

Manganin gauges are piezo resistive devices often used for pressure measurements on larger, planer impact experiments. These gauges function in this capacity as a result of their ability to change resistance in a consistent fashion relative to the pressure exerted against them. Pressures to 400 kbar have been reliably recorded (H.C. Vantine et al.[1]). Because the mini-manganin is significantly physically smaller than other types, there has been interest in the ability to place these gauges on small geometry (detonator) type experiments. Of primary concern is that the detonator shock front has significant curvature associated with it--especially at small geometries--and that this curvature will cause unknown distortion (stretching) of the manganin gauge and therefore may indicate erroneous data. A problem encountered while configuring this experiment was noise as a result of the proximity and high current levels of the fireset to the manganin gauge. Initial results indicate noise on the order of 130 mV peak-to-peak (p-p) and running as long as the CVR signal from the ringdown charge voltage of 775 V. These noise problems significantly worsened while discharging the full charge voltage of 1500 V on the fireset through the chip slapper.

Phillips, D; May, C; Vandersall, K; Garcia, F

2008-10-02T23:59:59.000Z

66

Experimental noise filtering by quantum control  

E-Print Network (OSTI)

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.

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

2014-04-03T23:59:59.000Z

67

Suppression of electron magnetotunneling between parallel two-dimensional GaAs/InAs electron systems by the correlation interaction  

SciTech Connect

Magnetotunneling between two-dimensional GaAs/InAs electron systems in vertical resonant tunneling GaAs/InAs/AlAs heterostructures is studied. A new-type of singularity in the tunneling density of states, specifically a dip at the Fermi level, is found; this feature is drastically different from that observed previously for the case of tunneling between two-dimensional GaAs tunnel systems in terms of both the kind of functional dependence and the energy and temperature parameters. As before, this effect manifests itself in the suppression of resonant tunneling in a narrow range near zero bias voltage in a high magnetic field parallel to the current direction. Magnetic-field and temperature dependences of the effect's parameters are obtained; these dependences are compared with available theoretical and experimental data. The observed effect can be caused by a high degree of disorder in two-dimensional correlated electron systems as a result of the introduction of structurally imperfect strained InAs layers.

Khanin, Yu. N.; Vdovin, E. E., E-mail: vdov62@yandex.ru [Russian Academy of Sciences, Institute of Microelectronics Technology and High Purity Materials (Russian Federation); Makarovsky, O. [University of Nottingham, School of Physics and Astronomy (United Kingdom)] [University of Nottingham, School of Physics and Astronomy (United Kingdom); Henini, M. [University of Nottingham, School of Physics and Astronomy, Nottingham Nanotechnology and Nanoscience Center (United Kingdom)] [University of Nottingham, School of Physics and Astronomy, Nottingham Nanotechnology and Nanoscience Center (United Kingdom)

2013-09-15T23:59:59.000Z

68

Gas turbine noise control  

Science Journals Connector (OSTI)

The use of gas turbine powered generators and pumping stations are likely to increase over the next two decades. Alternative fuel systems utilizing fluidized coal beds are likely in the near future and direct combustion of pulverized coal is also a possibility. The primary problem of generally unacceptable noise levels from gas turbine powered equipment affects both community noise and hearing conservation alike. The noise criteria of such plant remain a significant design factor. The paper looks at the technical and historical aspects associated with the noise generation process and examines past present and possible future approaches to the problem of silencing gas turbine units; adequately specifying the acoustical criteria and ratings; evaluates the techniques by which these criteria should be measured; and correlates these with the typical results achieved in the field.

Louis A. Challis and Associates Pty. Ltd.

1979-01-01T23:59:59.000Z

69

Independent Oversight Review of the Fire Protection Program at the Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory, September 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

Independent Oversight Review of the Independent Oversight Review of the Fire Protection Program at Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory May 2011 February 2013 September 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose.................................................................................................................................................... 1 2.0 Background ............................................................................................................................................. 1 3.0 Scope....................................................................................................................................................... 2

70

Independent Oversight Review of the Fire Protection Program at the Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory, September 2013  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Independent Oversight Review of the Independent Oversight Review of the Fire Protection Program at Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory May 2011 February 2013 September 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose.................................................................................................................................................... 1 2.0 Background ............................................................................................................................................. 1 3.0 Scope....................................................................................................................................................... 2

71

The laser satellites communications and laser noises  

Science Journals Connector (OSTI)

The gain of advanced optical communication systems is reduced by the noise of optical source. Coherent optical communication systems are in particular very sensitive to the noise transmitter and local laser. Optical space communications is on the verge ... Keywords: laser, laser communication, noise limits, optical communication, range loss, satellite communications, satellite systems, signal transfer loss, space channel

Marketa Mazalkova

2008-08-01T23:59:59.000Z

72

Saturation of two-level systems and charge noise in Josephson junction qubits Magdalena Constantin,1,* Clare C. Yu,1 and John M. Martinis2  

E-Print Network (OSTI)

Saturation of two-level systems and charge noise in Josephson junction qubits Magdalena Constantin to using superconducting Josephson junction qubits to construct quantum computers. Recent experiments7.094520 PACS number s : 74.40. k, 03.67.Pp, 77.22.Gm, 85.25.Cp I. INTRODUCTION The superconducting Josephson

Martinis, John M.

73

Hydrodynamic Limit for an Hamiltonian System with Boundary Conditions and Conservative Noise  

E-Print Network (OSTI)

We study the hyperbolic scaling limit for a chain of N coupled anharmonic oscillators. The chain is attached to a point on the left and there is a force (tension) $\\tau$ acting on the right. In order to provide good ergodic properties to the system, we perturb the Hamiltonian dynamics with random local exchanges of velocities between the particles, so that momentum and energy are locally conserved. We prove that in the macroscopic limit the distributions of the elongation, momentum and energy, converge to the solution of the Euler system of equations, in the smooth regime.

Nadine Even; Stefano Olla

2013-10-25T23:59:59.000Z

74

StochDecomp—Matlab package for noise decomposition in stochastic biochemical systems  

Science Journals Connector (OSTI)

......solved using the Matlab ODE solver...Analysis (PUA) Matlab package (Vanlier...and integrative Matlab package for computational...al. Detailed simulations of cell biology...in mesoscopic chemical systems. Nat...Stochastic Processes in Physics and...Supplementary Data - pdf file Supplementary......

Tomasz Jetka; Agata Charzynska; Anna Gambin; Michael P.H. Stumpf; Michal Komorowski

2014-01-01T23:59:59.000Z

75

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

E-Print Network (OSTI)

of the Supervisory Control and Data Acquisition (SCADA) system that resides in a centralized location (typically of service attacks, and resort to other malicious actions [2]. Various false data detection techniques based PMU measurements by spoofing the clocks that they use for synchronization [7]. Apart from malicious

Liberzon, Daniel

76

Noise | Open Energy Information  

Open Energy Info (EERE)

Noise Jump to: navigation, search Retrieved from "http:en.openei.orgwindex.php?titleNoise&oldid647800" Category: NEPA Resources...

77

Low-noise macroscopic twin beams  

E-Print Network (OSTI)

Applying a multiphoton-subtraction technique to two-color macroscopic squeezed vacuum state of light generated via high-gain parametric down conversion we conditionally prepare a new state of light: bright multi-mode low-noise twin beams. The obtained results demonstrate up to 8-fold suppression of noise in each beam while preserving and even moderately improving the nonclassical photon number correlations between the beams. The prepared low-noise macroscopic state, containing up to 2000 photons per mode, is not among the states achievable through nonlinear optical processes. The proposed technique substantially improves the usefulness of twin beams for quantum technologies.

Timur Sh. Iskhakov; Vladyslav C. Usenko; Radim Filip; Maria V. Chekhova; Gerd Leuchs

2014-08-27T23:59:59.000Z

78

Ultrahigh-sensitivity high-linearity photodetection system using a low-gain avalanche photodiode with an ultralow-noise readout circuit  

E-Print Network (OSTI)

A highly sensitive photodetection system with a detection limit of 1 photon/s was developed. This system uses a commercially available 200-mm-diameter silicon avalanche photodiode (APD) and an in-house-developed ultralow-noise readout circuit, which are both cooled to 77 K. When the APD operates at a low gain of about 10, it has a high-linearity response to the number of incident photons and a low excess noise factor. The APD also has high quantum efficiency and a dark current of less than 1 e/s at 77 K. This photodetection system will shorten the measurement time and enable higher spatial and wavelength resolution for near-field scanning optical microscopes.

Makoto Akiba; Mikio Fujiwara; Masahide Sasaki

2005-03-04T23:59:59.000Z

79

A van der Pol coupled-oscillator model as a basis for developing a system for suppressing MHD instabilities in a tokamak  

SciTech Connect

The main parameters of tokamak discharges are known to be limited by large-scale MHD instabilities. Sometimes, the instabilities lead to a rapid (on time scales of tens of microseconds) disruption of the discharge current and to the release of all the energy stored in the plasma column at the discharge chamber wall. This process, which is called the disruptive instability, may have irreversible catastrophic consequences for the operation of a fusion reactor. In the present paper, a study is made of the dynamics of self-oscillations in systems of two and six van der Pol coupled oscillators. A van der Pol coupled-oscillator model is used to develop a multivariable feedback controller based on the combined principle of compensating for internal cross feedbacks within the object and introducing damping feedbacks in each control channel. By using mathematical simulation methods, it is shown that the controller designed guarantees the suppression of self-oscillations in a system of van der Pol oscillators over a fairly broad range of parameters of the object under control (and thereby provides the structural stability of the object). The nonlinear control system model makes it possible to suppress coupled MHD perturbations developing in a tokamak plasma.

Semenov, I. B. [Russian Research Centre Kurchatov Institute, Nuclear Fusion Institute (Russian Federation); Mitrishkin, Yu. V. [Russian Academy of Sciences, Institute of Control Sciences (Russian Federation); Subbotin, A. A. [Russian Research Centre Kurchatov Institute, Nuclear Fusion Institute (Russian Federation); Vertinskii, A. G. [Moscow Institute of Physics and Technology (Russian Federation); Marusov, N. L. [Russian Research Centre Kurchatov Institute, Nuclear Fusion Institute (Russian Federation); Sushin, I. S. [Moscow Institute of Physics and Technology (Russian Federation)

2006-02-15T23:59:59.000Z

80

Noise properties of mutually sustained microwave-optoelectronic oscillator pair  

E-Print Network (OSTI)

Noise properties of mutually sustained microwave-optoelectronic oscillator pair E. Shumakher and G microwave-optoelectronic oscillator pair are described. The two oscillators have different spectral purities and exhibits low phase noise and highly suppressed spurious modes. Optoelectronic oscillators are employed

Eisenstein, Gadi

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Technical evaluation of the noise and isolation testing of the safety features actuation system at the Davis Besse Nuclear Power Station, Unit 1  

SciTech Connect

This report documents the technical evaluation of the noise and isolation testing of the safety features actuation system at the Davis Besse Nuclear Power Station, Unit 1. The tests were to verify that faults on the non-Class 1E circuits would not propagate to the Class 1E circuits and degrade them below acceptable levels. The tests conducted demonstrated that the safety features actuation system did not degrade below acceptable levels nor was the system's ability to perform its protective functions affected.

Selan, J.C.

1981-07-01T23:59:59.000Z

82

Chapter 9 Audible Noise  

NLE Websites -- All DOE Office Websites (Extended Search)

noise limits or defer to the states or the federal government for noise limits. BPA has established a transmission line design criterion for corona-generated noise (L 50...

83

Fundamentals of Electronic Noise  

Science Journals Connector (OSTI)

At first the physical sources of the most important types of noise within a receiver—thermal and shot noise—as well as the antenna noise are discussed and their power spectral densities are given.

Professor Dr.-Ing. Karl-Heinz Löcherer…

1982-01-01T23:59:59.000Z

84

SOLAR RADIO TYPE-I NOISE STORM MODULATED BY CORONAL MASS EJECTIONS  

SciTech Connect

The first coordinated observations of an active region using ground-based radio telescopes and the Solar Terrestrial Relations Observatory (STEREO) satellites from different heliocentric longitudes were performed to study solar radio type-I noise storms. A type-I noise storm was observed between 100 and 300 MHz during a period from 2010 February 6 to 7. During this period the two STEREO satellites were located approximately 65 Degree-Sign (ahead) and -70 Degree-Sign (behind) from the Sun-Earth line, which is well suited to observe the earthward propagating coronal mass ejections (CMEs). The radio flux of the type-I noise storm was enhanced after the preceding CME and began to decrease before the subsequent CME. This time variation of the type-I noise storm was directly related to the change of the particle acceleration processes around its source region. Potential-field source-surface extrapolation from the Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) magnetograms suggested that there was a multipolar magnetic system around the active region from which the CMEs occurred around the magnetic neutral line of the system. From our observational results, we suggest that the type-I noise storm was activated at a side-lobe reconnection region that was formed after eruption of the preceding CME. This magnetic structure was deformed by a loop expansion that led to the subsequent CME, which then suppressed the radio burst emission.

Iwai, K.; Tsuchiya, F.; Morioka, A.; Misawa, H. [Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Miyoshi, Y.; Masuda, S. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi 464-8601 (Japan); Shimojo, M. [Nobeyama Solar Radio Observatory, Nobeyama, Nagano 384-1305 (Japan); Shiota, D. [Advanced Science Institute, RIKEN (Institute of Physics and Chemical Research), Wako, Saitama 351-0198 (Japan); Inoue, S., E-mail: kazumasa-iwai@pparc.gp.tohoku.ac.jp [National Institute of Information and Communications Technology, Koganei, Tokyo 184-0015 (Japan)

2012-01-10T23:59:59.000Z

85

Noise and Hearing Conservation  

NLE Websites -- All DOE Office Websites (Extended Search)

Hearing Conservation Hearing Conservation Mary L. Doyle NOISE & HEARING CONSERVATION Mary L. Doyle, MPH, RN, COHN-S/CM DOE Headquarters January 16, 2002 1.0.1.~ CAUSES OF HEARING LOSS * Congenital * Environmental Exposures * Hereditary * Illness *Injury * Noise * Occupational * Non-Occupational * Sociacusis S.O.S. eon.ua.nt. OTOTOXIC DRUGS Can Affect Cochlea or Vestibular System * Aminoglycoside Antibiotics * Diuretics * Cancer Chemotherapy * Aspirin * Quinines * Usually Permanent * Consider Benefit-Risk Ratio S.O.S. eon.ua.nts HEARING * Modification of Acoustic Wave by Outer Ear * Conversion of Modified Acoustic Wave to Vibration of Eardrum * Middle Ear * Inner Ear * Transformation of Mechanical Movement to Nerve Impulses S.O.S. CoMubRis OTOTOXIC INDUSTRIAL

86

NoiseSPY: A Real-Time Mobile Phone Platform for Urban Noise Monitoring and Mapping  

Science Journals Connector (OSTI)

In this paper we present the design, implementation, evaluation, and user experiences of the NoiseSpy application, our sound sensing system that turns the mobile phone into a low-cost data logger for monitoring environmental noise. It allows users to ... Keywords: mobile computing, noise mapping, online mapping, pervasive sensing, pollution monitoring, ubiquitous computing.

Eiman Kanjo

2010-08-01T23:59:59.000Z

87

Benchmark enclosure fire suppression experiments - phase 1 test report.  

SciTech Connect

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.

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

2007-06-01T23:59:59.000Z

88

Characterization and Suppression of the Electromagnetic Interference Induced Phase Shift in the JLab FEL Photo - Injector Advanced Drive Laser System  

SciTech Connect

The drive laser for the photo-cathode gun used in the JLab Free Electron Laser (FEL) facility had been experiencing various phase shifts on the order of tens of degrees (>20{sup o} at 1497 MHz or >40ps) when changing the Advanced Drive Laser (ADL) [2][3][4] micro-pulse frequencies. These phase shifts introduced multiple complications when trying to setup the accelerator for operation, ultimately inhibiting the robustness and overall performance of the FEL. Through rigorous phase measurements and systematic characterizations, we determined that the phase shifts could be attributed to electromagnetic interference (EMI) coupling into the ADL phase control loop, and subsequently resolved the issue of phase shift to within tenths of a degree (<0.5{sup o} at 1497 MHz or <1ps). The diagnostic method developed and the knowledge gained through the entire process will prove to be invaluable for future designs of similar systems.

F. G. Wilson, D. Sexton, S. Zhang

2011-09-01T23:59:59.000Z

89

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

SciTech Connect

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.

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

2007-06-01T23:59:59.000Z

90

Parasitic Effects of Grounding Paths on Common-Mode EMI Filter's Performance in Power Electronics Systems  

SciTech Connect

High-frequency common-mode (CM) electromagnetic-interference (EMI) noise is difficult to suppress in electronics systems. EMI filters are used to suppress CM noise, but their performance is greatly affected by the parasitic effects of the grounding paths. In this paper, the parasitic effects of the grounding paths on an EMI filter's performance are investigated in a motor-drive system. The effects of the mutual inductance between two grounding paths are explored. Guidelines for the grounding of CM EMI filters are derived. Simulations and experiments are finally carried out to verify the theoretical analysis.

Wang, Shuo [ORNL; Maillet, Yoann [Virginia Polytechnic Institute and State University (Virginia Tech); Wang, Fei [ORNL; Lai, Rixin [General Electric; Luo, Fang [Virginia Polytechnic Institute and State University (Virginia Tech); Boroyevich, Dushan [Virginia Polytechnic Institute and State University (Virginia Tech)

2010-01-01T23:59:59.000Z

91

Noise Pollution Control (Minnesota) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Noise Pollution Control (Minnesota) Noise Pollution Control (Minnesota) Noise Pollution Control (Minnesota) < Back Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Residential Installer/Contractor Rural Electric Cooperative Tribal Government Low-Income Residential Schools Retail Supplier Institutional Multi-Family Residential Systems Integrator Fuel Distributor Nonprofit General Public/Consumer Transportation Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Minnesota Program Type Environmental Regulations These regulations set noise standards and direct municipalities to take reasonable measures to prevent the establishment of land use activities

92

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

E-Print Network (OSTI)

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...

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

93

Wind turbine aeroacoustic noise and noise mitigation strategies.  

Science Journals Connector (OSTI)

Wind turbines are becoming an important piece of the solution to low?carbon power production. However as more turbines are installed near population centers the environmental impacts associated with these machines such as noise are also becoming more obvious. Aeroacousticnoise is generally thought to be the greatest source of acoustical noise in wind turbine systems. This study will present measurement results collected at the National Wind Technology Center on an operating wind turbine that characterize the total received acoustic field surrounding the turbine. Designs and preliminary measurements of trailing edge modifications to the outboard airfoil sections will be discussed as a means of partial noise mitigation. In addition future aeroacousticnoise treatments and measurement plans will be mentioned.

Michael Asheim; Paul Papas; Patrick Moriarty; Jon Collis

2010-01-01T23:59:59.000Z

94

Water Mist Suppression in Conjunction with Displacement  

E-Print Network (OSTI)

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

Hickman, Mark

95

Development of long-term data acquisition system of noise exposure and personal behavior for analysis of health risk: Research background  

Science Journals Connector (OSTI)

Since people living in urban areas are continuously exposed to loud environmental noises for a long duration the noise has to be treated not only as nuisance in our daily lives and adverse psychological effect but also as possible risk on health. WHO has presented an environmental noise guideline and has suggested dangers or risks on health by long-term high noise exposure and has recently published nighttime noise guideline to prevent adverse health effect to sleep disturbance. Some research projects in EU have revealed that detailed measurement in time of individual noise exposure is needed to improve the current assessment method instead of those based on energy-averaged value over the exposed duration to noise. It suggests necessity of short time-interval measurement of individual noise exposure as well as information when and where people are exposed to the noise. It is also necessary to measure environmental condition in nightitme since the condition very likely disturbs our sleep and therefore gives some effects to our health. From these circumstances and relating issues in Japanese we have established a new research project which aims to investigate the effect of individual noise exposure on health. This report presents the research background and objectives.

Hiroyuki Imaizumi; Kazutoshi Fujimoto; Ken Anai; Yasuhiro Hiraguri

2012-01-01T23:59:59.000Z

96

Mixed noise removal by weighted low rank model  

Science Journals Connector (OSTI)

Abstract Mixed noise removal has been a challenging task due to the complex noise distribution. One representative type of mixed noise is the additive white Gaussian noise (AWGN) coupled with impulse noise (IN). Most mixed noise removal methods first detect and restore impulse pixels using median-type filters, and then perform AWGN removal. Such mixed noise removal methods, however, are less effective in preserving image structures, and tend to over-smooth image details. In this paper, we present a novel mixed noise removal method by proposing a weighted low rank model (WLRM). By grouping image nonlocal similar patches as a matrix, we reconstruct the clean image by finding the weighted low rank approximation or representation of the matrix. IN can be well suppressed by the adaptive weight setting, while the image global structure and local edges can be well preserved via the low rank model fitting. The weight setting and low rank model fitting are jointly optimized in WLRM. Our experiments validate that WLRM leads to very promising mixed noise removal results in terms of both quantitative measure and visual perception.

Jielin Jiang; Jian Yang; Yan Cui; Lei Luo

2014-01-01T23:59:59.000Z

97

Wind farm noise  

Science Journals Connector (OSTI)

Arrays of small wind turbines recently coined as “wind farms” offer several advantages over single larger wind turbines producing the same electrical power. Noise source characteristics of wind farms are also different from those associated with a single wind turbine. One?third octave band noise measurements from 2 Hz to 10 kHz have been made and will be compared to measurements of noise produced by a single large wind turbine. [J. R. Balombin Technical Memorandum 81486.

Gregory C. Tocci; Brion G. Koning

1981-01-01T23:59:59.000Z

98

Power spectrum estimates of high frequency noise generated by high impedance arcing faults on distribution systems / by Thomas James Talley  

E-Print Network (OSTI)

. 1 See Ap- pendix A. 2 Recor- DC-80kHz +20v . 57vpk 10vpk 1 47db der See Ap- pendix A. 3 Other measurement considerations involved the frequency response of the relaying Current Transformer (CT's) at power system substations which were... . 1 See Ap- pendix A. 2 Recor- DC-80kHz +20v . 57vpk 10vpk 1 47db der See Ap- pendix A. 3 Other measurement considerations involved the frequency response of the relaying Current Transformer (CT's) at power system substations which were...

Talley, Thomas James

2012-06-07T23:59:59.000Z

99

Noise & Vibration Ctrl What's noise and what's vibration?  

E-Print Network (OSTI)

Institut für Technische Akustik Noise & Vibration Ctrl · What's noise and what's vibration? ­ Noise = unwanted sound ­ Vibration = oscillations of structures © Prof. B.A.T. Petersson #12;Institut für Technische Akustik Noise & Vibration Ctrl. · What's Noise & Vibration Control? Genera t ion Transmiss ion

Berlin,Technische Universität

100

A time history algorithm for aircraft noise  

Science Journals Connector (OSTI)

In the course of the development of a comprehensive computer airport noisemodel offering a choice of noise metrics (see previous paper) the ASDS metric (“Aircraft Sound Description System”) required the computation of the time noise levels from aircraft flyover exceed specified thresholds. A package of subroutines was developed that performs a noise level time history simulation by tracking aircraft position and orientation along a three?dimensional flight path using variable time steps depending on the rate of noise level change. The A?weighted noise levels at observer positions are calculated for each time step from two three?dimensional models: a three?component jet engine noise emission model (front fan rear fan jet) where each component varies with engine thrust at a different rate; and a propagation model describing the excess attenuation of A?weighted levels as a function of distance. Both models use aircraft specific empirical parameters determined from measured spectral data and calibrated by comparing calculated and measured maximum A?weighted flyover levels for a range of practical distances. The subroutine package is capable of calculating threshold exceedance times cumulative distributions of noise levels and the time?integrated energy equivalent noise level from an aircraft flyover. [Work supported by the U. S. Department of Transportation.

R. Rackl

1977-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Coherence and anticoherence resonance tuned by noise  

Science Journals Connector (OSTI)

We present numerical evidence and a theoretical analysis of the appearance of anticoherence resonance induced by noise, not predicted in former analysis of coherence resonance. We have found that this phenomenon occurs for very small values of the intensity of the noise acting on an excitable system, and we claim that this is a universal signature of a nonmonotonous relaxational behavior near its oscillatory regime. Moreover, we demonstrate that this new phenomenon is totally compatible with the standard situation of coherence resonance appearing at intermediate values of noise intensity.

A. M. Lacasta; F. Sagués; J. M. Sancho

2002-10-24T23:59:59.000Z

102

Noise Control of a Flare Stack  

Science Journals Connector (OSTI)

As part of its noise abatement program the Standard Oil Company of California has undertaken to reduce the noise radiated from the flare stacks serving the new process plants at the El Segundo Refinery. These flares used to burn excess refinery hydrocarbon gases have to operate smokelessly. To accomplish this high?pressure steam jets are used to discharge a turbulent steam?air mixture into the combustion zone. This system although muffled proved to be an intolerable source of noise in the adjacent community. An examination of the noise spectrum indicated that the mixing between the steam ejected from the 3 4 ? in. ? diam primary nozzle and the ambient air was a major source of noise. A series of exploratory model scale tests were conducted in an effort to reduce the noise. By replacing a single 3 4 ? in. ?diam nozzle with a multiple nozzle the radiated noise was reduced by 16 dB. The multiple nozzle configuration and the experimental program leading to its design are described.

A. S. Hersh; J. G. Seebold

1970-01-01T23:59:59.000Z

103

Heart Rate Artifact Suppression.  

E-Print Network (OSTI)

??Motion artifact strongly corrupts heart rate measurements in current pulse oximetry systems. In many, almost any motion will greatly diminish the system’s ability to extract… (more)

Dickson, Christopher

2012-01-01T23:59:59.000Z

104

Suppression of image autocorrelation artefacts in spectral domain optical coherence tomography and multiwave digital holography  

SciTech Connect

An improved method for suppressing image artefacts in spectral domain optical coherence tomography (SD OCT) and multiwave digital holography, caused by the influence of coherent noise in the course of successive registration of an autocorrelation component and informative signal is reported. The method allows complete suppression of all types of coherent noises, provided that the sample of values used to record the autocorrelation component satisfies the conditions of Kotelnikov's theorem: in SD OCT - for the transverse structure of the studied medium, in multiwave digital holography - for the envelop function of the radiation source frequency tuning spectrum.

Gelikonov, V M; Gelikonov, G V; Terpelov, D A; Shabanov, D V; Shilyagin, P A [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

2012-05-31T23:59:59.000Z

105

Joint Uncertainty Decoding with Unscented Transform for Noise-robust Subspace Gaussian Mixture Models  

E-Print Network (OSTI)

T S C R T S C #12;Noise compensation Larger modelling power higher recognition accuracy. Our systemsJoint Uncertainty Decoding with Unscented Transform for Noise-robust Subspace Gaussian Mixture [Povey et al., 2011] In mismatched condition (i.e. noise), the gain disappears Goal Noise compensation

Edinburgh, University of

106

Hazard of intermittent noise exposures  

Science Journals Connector (OSTI)

The chief shortcoming of the “equal energy” hypothesis—the notion that equal products of time and intensity provide equal hazard—is that the recuperative powers of the auditory system are essentially ignored. A single sustained stimulus is regarded as no more dangerous than an intermittent one of the same total energy. A two?year study of the effect of intermittency on the TTS produced in normal young adults by 6? or 8?h exposures to octave bands of noise whose center frequencies ranged from 250 to 4000 Hz indicates that even for the most hazardous noise (the 4000?Hz OB) cutting the cumulative exposure time in half by interjecting regular quiet periods will permit an increase in level of 5 dB for constant TTS at least up to about 100 dB SPL. At 1000 Hz the trading relation is 6–7 dB for halving time and at 250 Hz is even greater. Thus the 5?dBA?per?halving?time relation employed by the present OSHA standard is essentially correct for intermittent noise except perhaps above 100 to 105 dBA where the equal?energy hypothesis may be more appropriate for spectra with high?frequency dominance. A single 5?dBA “correction for intermittency” is an oversimplification. [Research supported by the National Institute for Occupational Safety and Health Public Health Service.

W. D. Ward

1974-01-01T23:59:59.000Z

107

Prediction of noise emissions from industrial flares  

Science Journals Connector (OSTI)

In many industries where combustible waste gases are obtained flares are used to burn these gases in a controlled manner. Among other environmental aspects the noise emissions associated with flaring are becoming increasingly important in many countries as population density goes up and residential and industrial areas move closer together. Installing noise control equipment on flares is almost impossible while they are in service since flares are typically a safety related plant component that can only be turned off after the connected plant has been shut down. Accordingly in order to plan appropriate noise controlmeasures in time and to avoid unnecessary costs predicting the noise emissions of flares as early in the design process as possible is crucial. This requires knowledge of the relevant individual noise sources associated to the flare system and the ability to calculate their respective contribution ? in the operating condition in question ? to the overall noise emission based on the data available in the planning stage. The present paper summarizes these sources and outlines some of the individual effects and parameters having an influence on the acoustical characteristics of flares.

Carl?Christian Hantschk; Edwin Schorer

2008-01-01T23:59:59.000Z

108

Shot Noise in Graphene  

Science Journals Connector (OSTI)

We report measurements of current noise in single-layer and multilayer graphene devices. In four single-layer devices, including a p-n junction, the Fano factor remains constant to within ±10% upon varying carrier type and density, and averages between 0.35 and 0.38. The Fano factor in a multilayer device is found to decrease from a maximal value of 0.33 at the charge-neutrality point to 0.25 at high carrier density. These results are compared to theories for shot noise in ballistic and disordered graphene.

L. DiCarlo; J. R. Williams; Yiming Zhang; D. T. McClure; C. M. Marcus

2008-04-14T23:59:59.000Z

109

Geothermal Noise Control  

Science Journals Connector (OSTI)

In these times of growing need for new energy sources geothermal has shown great promise. Geothermal is a green relatively nonpolluting energy source that can provide power on a scale large enough to make a significant contribution to our needs. One of the challenges of geothermal development is noise emission. This occurs after a well encounters steam and before a plant is constructed. It also arises from the necessity of shutting down a power plant for periodic maintenance. While the power plant is down the steam and noise is vented to the atmosphere.

Marshall Long

2009-01-01T23:59:59.000Z

110

The room noise criteria (RNC) metric.  

Science Journals Connector (OSTI)

The recent ANSI S12.2:2008 room noise criteria contains both a survey and an engineering method to specify room noise criteria. The methods use A?weighting and extended NC respectively. A new metric titled like the standard room noise criteria (RNC) is included as a diagnostic tool. It is based on human hearing and more correctly assesses low?frequency sound. In particular it is sensitive to the standard deviation to random noise and/or low?frequency surging in the 16–125 Hz octave bands such as the sound that can be produced by HVAC systems or other devices. It provides a bridge between the NC and RC criteria by correctly predicting the need for the less stringent (at low frequencies) NC criteria when the HVAC system is well designed (no surging moderate standard deviation) and also correctly predicting the more stringent (at low frequencies) RC criteria when the HVAC system noise has a large standard deviation and/or surging.

2009-01-01T23:59:59.000Z

111

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

E-Print Network (OSTI)

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 ...

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

2013-01-01T23:59:59.000Z

112

E-Print Network 3.0 - ac phase noise Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Laser Amplitude and Phase Summary: Floor In a phase-noise setup, system noise floor verification is ac- complished by driving both ports... -Dynamic-Range Laser Amplitude and...

113

Road traffic noise mapping in Guangzhou using GIS and GPS  

Science Journals Connector (OSTI)

Abstract The primary objective of this study is to develop day and night road traffic noise maps for Guangzhou using Geographical Information Systems (GIS) and Global Positioning Systems (GPS). First, as speed-density relation is used to estimate the traffic volume from GPS data collected from floating cars. Meanwhile, the attributes of the roads and buildings are automatically exported from GIS. Second, a single vehicle noise emission model is combined with a noise propagation model to formulate a regional traffic noise calculation model that accounts for the traffic noise attenuation in an urban area. The algorithm is optimized by intelligently dividing the computational grids, filtering the traffic noise sources automatically and performing a quick index of the estimation objects. Finally, the day and night road traffic noise levels in Guangzhou are estimated to create two traffic noise maps. The accuracy of the developed algorithm is validated by conducting a traffic noise monitoring experiment in several districts of Guangzhou with different road types. The results show that the average error between the estimated and measured values is below 2.0 dB.

Ming Cai; Jingfang Zou; Jiemin Xie; Xialin Ma

2015-01-01T23:59:59.000Z

114

CO{sub 2} dial transmitter/receiver noise characterization and related correlated noise issues  

SciTech Connect

Our approach concerning the development of hard target return CO{sub 2} DIAL transmitter/receiver systems is two phased- (i) through analysis and experiment, develop a fundamental understanding of the transmitter/receiver physics specific to DIAL systems and (ii) apply these fundamentals in the development of optimal performance DIAL transmitter/receiver systems. We present our progress and results towards these objectives with the following topics addressed: A general overview of the DIAL transmitter/receiver system characterization effort with a focus on transceiver noise processes. The effects of correlated noise on DIAL performance, especially those effecting statistical convergence over long sample structures, is , introduced. And, preliminary measurements of a low-noise, ``white`` receiver prototype are presented.

Cooke, B.; Schmitt, M.; Goeller, R.; Czuchlewski, S.; Fuller, K.; Olivas, N.; Laubscher, B.; Sander, R.

1996-02-01T23:59:59.000Z

115

Numerical tools applied to power reactor noise analysis  

SciTech Connect

In this paper, the development of numerical tools allowing the determination of the neutron noise in power reactors is reported. These tools give the space-dependence of the fluctuations of the neutron flux induced by fluctuating properties of the medium in the 2-group diffusion approximation and in a 2-dimensional representation of heterogeneous systems. Some applications of these tools to power reactor noise analysis are then described. These applications include the unfolding of the noise source from the resulting neutron noise measured at a few discrete locations throughout the core, the study of the space-dependence of the Decay Ratio in Boiling Water Reactors, the noise-based estimation of the Moderator Temperature Coefficient of reactivity in Pressurized Water Reactors, the modeling of shell-mode core barrel vibrations in Pressurized Water Reactors, and the investigation of the validity of the point-kinetic approximation in subcritical systems. (authors)

Demaziere, C.; Pazsit, I. [Chalmers Univ. of Technology, Dept. of Nuclear Engineering, SE-412 96 Goeteborg (Sweden)

2006-07-01T23:59:59.000Z

116

Nuclear-spin noise  

Science Journals Connector (OSTI)

The spectral density of the Nyquist noise current in a tuned circuit coupled to a sample of nuclear spins has been measured at He4 temperatures with a dc SQUID used as a rf amplifier. When the sample is in thermal equilibrium, a dip is observed in the spectral density at the Larmor frequency. For zero spin polarization, on the other hand, a bump in the spectral density is observed. This bump is due to temperature-independent fluctuations in the transverse component of magnetization, and represents spontaneous emission from the spins into the circuit.

Tycho Sleator; Erwin L. Hahn; Claude Hilbert; John Clarke

1985-10-21T23:59:59.000Z

117

Low-power low-noise analog circuits for on-focal-plane signal processing of infrared sensors Bedabrata Pain, Sunetra K. Mendis  

E-Print Network (OSTI)

Low-power low-noise analog circuits for on-focal-plane signal processing of infrared sensors imager performance are presented. To enable the detection of high background IR images, an in-pixel current-mode background suppression scheme is presented. The background suppression circuit consists

Fossum, Eric R.

118

Parallel barrier effectiveness, Dulles noise barrier project.  

Science Journals Connector (OSTI)

In an effort to minimize the cost and maximize the effectiveness of highway noise barriers the Federal Highway Administration (FHWA) and a National Pooled Fund Panel (made up of 14 states) funded a field study program on an experimental highway noise barrier. A test barrier was constructed in 1984 at a site at Dulles International Airport in Chantilly Virginia. The study conducted from May 1989 to August 1989 by the U.S. Department of Transportation Research and Special Programs Administration Transportation System Center (U.S. DOT/RSPA/TSC) focused on the use of absorptive treatment and tilting as a means of improving the insertion loss of two parallel highway noise barriers. Measurements were conducted with both controlled moving point sources (trucks) and an artificial fixed?point source (speaker system). Results show (1) the addition of absorptive treatment to the roadside face of two vertical parallel highway noise barriers eliminated multiple reflections and was found to improve the insertion loss (2–6 dB); (2) tilting proved to be an effective alternative to absorptive treatment in eliminating the multiple reflections and subsequent degradation in performance of two vertical reflective barriers; and (3) use of an artificial fixed?point source is not a viable test of barrier effectiveness.

Gregg G. Fleming; Edward J. Rickley

1991-01-01T23:59:59.000Z

119

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

SciTech Connect

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.

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

120

Noise from Centrifugal Fans  

Science Journals Connector (OSTI)

The sound power radiated from the discharge of centrifugal fans of diameters between 3 and 6 1 2 ? inches has been measured as a function of fan dimensions and operating conditions. The measurements were made by arranging the fan under test to discharge into an 11 foot nonreflecting tube in which the static pressure could be controlled. Air was exhausted from the tube through a side port of high acoustic impedance located part way down the tube. The detectingmicrophone which is located in the tube between the exit port and the acoustic termination is out of the air stream and therefore not subject to wind noise. The total discharge noise power P in watts in the range 75 to 10 000 cps was found empirically to be given by P?=?0.90?×?10 ?4 (D/W)?H 3 ?+?5.2?×?10 ?10 (Q 5 /W 4 D 8 ) where D and W are the fan diameter and width respectively in inches H is the static pressure in inches of water and Q is the air flow in cubic feet per minute. The angular frequency of the fan wheel does not appear explicitly since this quantity is uniquely specified by H Q D and W. Spectral analysis indicates that the power is concentrated primarily at low frequencies. Application of the results of this study to design problems will be discussed.

R. B. Goldman; G. C. Maling

1955-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Eurospeech 2001 -Scandinavia Sub-Band Based Additive Noise Removal for Robust Speech  

E-Print Network (OSTI)

Eurospeech 2001 - Scandinavia Sub-Band Based Additive Noise Removal for Robust Speech Recognition J analysis, etc. We will then introduce a sub-band based scheme to remove the noise effect from corrupted speech to make recognition system immune to additive noise. We will report on experiments on TI digits

122

Quantum noise in optical interferometers  

SciTech Connect

We study the photon counting noise in optical interferometers used for gravitational wave detection. In order to reduce quantum noise, a squeezed vacuum is injected into the usually unused input port. It is investigated under which conditions the gravitational wave signal may be amplified without increasing counting noise concurrently. Such a possibility was suggested as a consequence of the entanglement of the two output ports of a beam splitter. We find that amplification without concurrent increase of noise is not possible for reasonable squeezing parameters. Photon distributions for various beam splitter angles and squeezing parameters are calculated.

Voronov, Volodymyr G.; Weyrauch, Michael [Faculty of Physics, Taras Shevchenko National University of Kyiv, 03022 Kyiv (Ukraine); Physikalisch-Technische Bundesanstalt, D-38116 Braunschweig (Germany)

2010-05-15T23:59:59.000Z

123

Kink instability suppression with stochastic cooling pickup and kicker  

SciTech Connect

The kink instability is one of the major beam dynamics issues of the linac-ring based electron ion collider. This head-tail type instability arises from the oscillation of the electron beam inside the opposing ion beam. It must be suppressed to achieve the desired luminosity. There are various ways to suppress the instability, such as tuning the chromaticity in the ion ring or by a dedicated feedback system of the electron beam position at IP, etc. However, each method has its own limitation. In this paper, we will discuss an alternative opportunity of suppressing the kink instability of the proposed eRHIC at BNL using the existing pickup-kicker system of the stochastic cooling system in RHIC.

Hao Y.; Blaskiewicz, M.; Litvinenko, V.N.; Ptitsyn, V.

2012-05-20T23:59:59.000Z

124

Robust Shot Noise Measurement for Continuous Variable Quantum Key Distribution  

E-Print Network (OSTI)

We study a practical method to monitor in real-time the behavior of a Continuous Variable Quantum Key Distribution (CVQKD) system, and especially the shot noise measurement procedure, for the presence of an eavesdropper. The amount of secret key that can be extracted from the raw statistics of a CVQKD system depends strongly on a shot noise estimate since this quantity affects in particular the computation of the excess noise (i.e. noise in excess of the shot noise) added by an eavesdropper on the quantum channel. Some powerful quantum hacking attacks rely on faking the estimated value of the shot noise to hide an intercept-and-resend eavesdropping strategy, notably by targeting the calibration of the system, the saturation of the homodyne detection device or the wavelength dependency of some optical components. We describe a new countermeasure that consists in fairly general statistical tests build on top of an existing real-time shot-noise measurement technique and show that it is able to defeat all these attacks.

Sébastien Kunz-Jacques; Paul Jouguet

2014-06-29T23:59:59.000Z

125

A simulation model for urban traffic noise  

Science Journals Connector (OSTI)

Urban traffic noise is studied by a simulation model whose main features are the following: effects of traffic lights speed limit possibility of vehicles overtaking and driving styles. In the model there is a basic assumption about driver’s behavior (‘‘follow the leader’’) considering the case of straight and level road with two lanes for every carriageway and two traffic lights. Three driving styles are considered: A (‘‘quiet driver’’): change of gear at 60% of engine speed corresponding to maximum torque B (‘‘normal driver’’): at 80% C (‘‘fast driver’’): at 100%. The behavior rules provide for: keeping of safety distance overtaking if there are vehicles at different speeds deceleration and stop at traffic lights with red synchronization of two traffic lights if requested. From the kinematic side the model was validated by comparison with acceleration distribution of a real vehicle’s flow while the acoustic one was by the comparison with noise levels measured along urban streets. The simulation model lets one take into account the following factors concerning the traffic noise emission: main noise sources of vehicle (tires engine intake and exhaust system) traffic flow and maximum speed allowed traffic mix as regards different driving styles.

A. Di Giulio; F. Mancosu; C. Nucci; L. Zocchi

1999-01-01T23:59:59.000Z

126

Impedance Noise Identification for State-of-Health Prognostics  

SciTech Connect

Impedance Noise Identification is an in-situ method of measuring battery impedance as a function of frequency using a random small signal noise excitation source. Through a series of auto- and cross-correlations and Fast Fourier Transforms, the battery complex impedance as a function of frequency can be determined. The results are similar to those measured under a lab-scale electrochemical impedance spectroscopy measurement. The lab-scale measurements have been shown to correlate well with resistance and power data that are typically used to ascertain the remaining life of a battery. To this end, the Impedance Noise Identification system is designed to acquire the same type of data as an on-board tool. A prototype system is now under development, and results are being compared to standardized measurement techniques such as electrochemical impedance spectroscopy. A brief description of the Impedance Noise Identification hardware system and representative test results are presented.

Jon P. Christophersen; Chester G. Motloch; John L. Morrison; Ian B. Donnellan; William H. Morrison

2008-07-01T23:59:59.000Z

127

5th International Meeting Wind Turbine Noise  

E-Print Network (OSTI)

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, clean energy. While profiting from wind energy, the noise produced by a modern wind turbine becomes

Paris-Sud XI, Université de

128

Compost: A study of the development process and end-product potential for suppression of turfgrass disease  

E-Print Network (OSTI)

, biological control, compost, disease, fungi, microbiology, pathogen, suppression, turf, turfgrass Summary populations that can be suppressive towards plant pathogens. Although mechanisms of suppression are not fully microorganisms, or indirect eects on host systems through the supply of nutrients, improvement of soil structure

Boland, Greg J.

129

E-Print Network 3.0 - airborne acoustical noise Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

and lidar sensors. Consequently, the methodology for instru- ment calibration, noise reduction... in the data processing sequence. For an acoustic system, ambient ... Source:...

130

Cooper-pair current in the presence of flux noise  

Science Journals Connector (OSTI)

We study the effect of flux noise on the Cooper pair current of a superconducting charge pump. We generalize the definition of the current in order to take into account the contribution induced by the environment. It turns out that this dissipative current vanishes for charge noise but it is finite in general for noise operators that do not commute with the charge operator. We discuss in a generic framework the effect of flux noise and present a way to engineer it by coupling the system to an additional external circuit. We calculate numerically the pumped charge through the device by solving the master equation for the reduced density matrix of the system and show how it depends on the coupling to the artificial environment.

P. Solinas; M. Möttönen; J. Salmilehto; J. P. Pekola

2012-01-20T23:59:59.000Z

131

Magneto-optical disk drive technology using multiple fiber-coupled flying optical heads. Part II. Laser noise considerations  

Science Journals Connector (OSTI)

A magneto-optical data storage system utilizing single-mode fiber is capable of providing high signal-to-noise ratio (SNR) recording if laser noise sources are properly managed. In...

Wilde, Jeffrey P; Tselikov, Alexander A; Gray, George R; Zhang, Yongwei; Gangopadhyay, Shubhagat

2002-01-01T23:59:59.000Z

132

Human response to combined noise and vibration.  

E-Print Network (OSTI)

??The discomfort caused by the noise and vibration in cars is investigated in this thesis to improve understanding of how subjective judgements of noise and… (more)

Huang, Yuan

2012-01-01T23:59:59.000Z

133

Low noise charge ramp electrometer  

DOE Patents (OSTI)

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. 2 figs.

Morgan, J.P.; Piper, T.C.

1992-10-06T23:59:59.000Z

134

Noise removal from measurements while drilling an oil well  

Science Journals Connector (OSTI)

Systems to acquire borehole data during the drilling of oil and gas wells make use of measurement while drilling (MWD). One feature of this system is that it is able to do real?time measuring from a borehole; therefore there has been a lot of MWD use on drilling sites in recent years. There are a few types of MWD. Mud pulse?type MWD which uses a drilling circuit fluid is superior to the rest because of its reliability accuracy of data and less disturbance of the drilling schedule. The drilling circuit fluid is raised to a high pressure by a mud pump; borehole data which are recorded by the surface measuring system are contaminated by the pumping noise. Therefore it is necessary to remove the pumping noise to get objective data. This report describes the pumping noise removal system and the method used for the telemetry system from 2000 m depth.

Kazuho Hosono; Haruki Moriyama

1996-01-01T23:59:59.000Z

135

A first step toward a close proximity noise map  

Science Journals Connector (OSTI)

In recent years environmental noise has become a serious issue for civil infrastructure and environmental administration due to public concern over the subject of noise pollution. The most significant deterioration of environmental acoustics conditions comes from road traffic transportation. The predominant noise source is the combination of the tire/pavement interaction and the propulsion systems of the vehicles. Generally tire/pavement interaction is the principal source of noise for speeds above 40 km/h in the case of most modern cars. In this research geo?referenced close proximity rolling noise is used for acoustical characterization of asphalt concrete surfaces in an urban environment. A close proximity noise map of streets with low speed limits is presented for a reference speed of 50 km/h. Different pavements and pavement conditions common in urban streets are analyzed: dense and semidense asphalt concrete with Spanish denomination D?8 and S?12 respectively and on the other hand dense pavement at the end of its service life (D?8*). Noise levels from dense surfaces (D?8) increase significantly over time principally due to the appearance of surface defects such as cracks and ruts.

Moises Bueno; Urbano Viñuela; Fernando Terán; S. E. Paje; Jeane Luong

2008-01-01T23:59:59.000Z

136

Studies of RF Noise Induced Bunch Lengthening at the LHC  

SciTech Connect

Radio Frequency (RF) noise induced bunch lengthening can strongly affect the Large Hadron Collider (LHC) performance through luminosity reduction, particle loss, and other effects. This work presents measurements from the LHC that better quantify the relationship between the RF noise and longitudinal emittance blowup and identify the performance limiting RF components. The experiments presented in this paper confirmed the predicted effects on the LHC bunch length growth. Dedicated measurements were conducted in the LHC to gain insight in the effect of RF noise to the longitudinal beam diffusion. It was evident that the growth rate of the bunch length is strongly related to the accelerating voltage phase noise power spectral density around f{sub s} + kf{sub rev}, as predicted in [4]. The noise threshold for 2.5 ps/hr growth was estimated to -101 dBc/Hz (SSB flat noise spectral density from f{sub s} to the edge of the closed loop bandwidth). A 9 dB margin is achieved with the current RF configuration and the BPL on. With this formalism it is now possible to estimate the effect of different operational and technical RF configurations on the LHC beam diffusion. This formalism could also be useful for the design of future RF systems and the budgeting of the allowed noise.

Mastorides, T.; Rivetta, C.; Fox, J.D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /SLAC /CERN

2011-08-17T23:59:59.000Z

137

Suppression of the spontaneous emission of atoms and molecules  

SciTech Connect

We present an experimentally viable approach for suppressing the spontaneous emission in several atomic and molecular systems. We have shown [E. Frishman and M. Shapiro, Phys. Rev. Lett. 87, 253001 (2001)] that a coherent excitation of overlapping resonances followed by the application of infrequent interruptions can result in complete suppression of spontaneous emission. In the present work, the overlapping resonances result from splitting a single resonance with an external (spectator) field. An optimized superposition of the two components is formed by a shaped pulse excitation from the ground state.

Frishman, Einat; Shapiro, Moshe [Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, (Israel)

2003-09-01T23:59:59.000Z

138

Highly linear low noise amplifier  

E-Print Network (OSTI)

, the Low Noise Amplifier (LNA) is expected to provide high linearity, thus preventing the intermodulation tones created by the interference signal from corrupting the carrier signal. The research focuses on designing a novel LNA which achieves high...

Ganesan, Sivakumar

2007-09-17T23:59:59.000Z

139

Fire suppression and detection equipment  

SciTech Connect

Inspection and testing guidelines go beyond the 'Code of Federal Regulation'. Title 30 of the US Code of Federal Regulations (30 CFR) contains requirements and references to national standards for inspection, testing and maintenance of fire suppression and detection equipment for mine operators. However, federal requirements have not kept pace with national standards and best practices. The article lists National Fire Protection (NFPA) standards that are referenced by the US Mine Safety and Health Administration (MSHA) in 30 CFR. It then discusses other NFPA Standards excluded from 30 CFR and explains the NFPA standard development process. 2 refs., 3 tabs., 5 photos.

E.E. Bates [HSB Professional Loss Control, Lexington, KY (United States)

2006-01-15T23:59:59.000Z

140

Multiple phase estimation for arbitrary pure states under white noise  

E-Print Network (OSTI)

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.

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

2014-09-08T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

The Shot Noise Thermometer Lafe Frederick Spietz  

E-Print Network (OSTI)

Abstract The Shot Noise Thermometer Lafe Frederick Spietz 2006 This thesis describes the development and testing of the shot noise thermometer, or SNT, a new kind of noise thermometer based thermometer, the noise power from a tunnel junction is measured as a function of the DC voltage across

142

The Shot Noise Thermometer Lafe Frederick Spietz  

E-Print Network (OSTI)

Abstract The Shot Noise Thermometer Lafe Frederick Spietz 2006 This thesis describes the development and testing of the shot noise thermome- ter, or SNT, a new kind of noise thermometer based thermometer, the noise power from a tunnel junction is measured as a function of the DC voltage across

143

Noise and the Sound Insulation of Buildings  

Science Journals Connector (OSTI)

...Noise and the Sound Insulation of Buildings F. Ingerslev It is claimed that noise...well-being. An outstanding task for the building industry in the 1980s is to ensure a proper noise climate in new buildings. The target must be to obtain a noise...

1972-01-01T23:59:59.000Z

144

Shot noise at the quantum point contact in InGaAs heterostructure  

SciTech Connect

We study the shot noise at a quantum point contact (QPC) fabricated in an InGaAs/InGaAsP heterostructure, whose conductance can be electrically tuned by the gate voltages. Shot noise suppression is observed at the conductance plateau of N(2e{sup 2}/h) (N = 4,5,and 6), which indicates the coherent quantized channel formation in the QPC. The electron heating effect generated at the QPC explains the deviation of the observed Fano factor from the theory.

Nishihara, Yoshitaka; Nakamura, Shuji; Ono, Teruo [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kobayashi, Kensuke [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Kohda, Makoto [Department of Materials Science, Tohoku University, 6-6-02 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579, Japan and PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Nitta, Junsaku [Department of Materials Science, Tohoku University, 6-6-02 Aramaki-aza Aoba, Aoba-ku, Sendai 980-8579 (Japan)

2013-12-04T23:59:59.000Z

145

Noise Amplitude Distribution of Impulsive Noise from Measurements in a Power Substation  

E-Print Network (OSTI)

Noise Amplitude Distribution of Impulsive Noise from Measurements in a Power Substation Qingshan-This paper presents ultra-wide-band measurements of impulsive noise within an electricity substation compound analysis of these events is presented. Index Terms--Electricity substation, impulsive noise, noise

Atkinson, Robert C

146

Steam Turbine Control Valve Noise  

Science Journals Connector (OSTI)

Although noise problems with steam turbine control valves have existed before they have become more prominent with nuclear turbines whose valves range to 20 in. in diameter. Our first?generation nuclear control valves were unacceptably noisy when operating under chocked conditions. These noise levels have been ameliorated by incorporation of a valve cage with numerous small holes. Rational design rules for this “dispersive muffler” have been developed from published multiple?jet noise data and improved through our own tests. However we are also evaluating other low?noise valve configurations which are consistent with turbine requirements. The approach we are developing is to investigate the internal aerodynamic noisegeneration in small air model tests and to combine this with measurements of pipe?wall transmission characteristics (being reported separately) to predict externally radiated noise. These predictions will be checked in a new steam test facility for complete scale?model valves. The small air tests show that acoustic efficiencies of throttling valve flows tend to vary with third power of Mach number when exhausting into space and with a lesser power when enclosed in a downstream pipe. At some pressure ratios narrow?band spikes appear in the spectrum and for some configurations step changes in sound power are associated with transitions in flow regimes.

Frank J. Heymann; Michael A. Staiano

1973-01-01T23:59:59.000Z

147

This paper investigates the use of higher-order autoregressive vector predictors for tracking the noise in noisy speech signals.  

E-Print Network (OSTI)

of power-spectral vectors derived from a short-time Fourier transform analysis of the noise signal compensated for the estimated noise. However, predictors of order greater than 1 are not observed to improve- pose of compensating for the effects of non-stationary noise on a speech recognition system. We model

Singh, Rita

148

Noise emissions from new electric options: Coal conversion and on?site generation  

Science Journals Connector (OSTI)

Two alternatives being considered for reducing the use of imported petroleum are the reconversion of oil?fired electric power plants to burn coal or the construction of small on?site generators which would make use of the waste heat from diesel generators to improve fuel efficiency. In urban areas there may be insufficient distance between the noise sources and residents to act as an acoustical buffer zone to attenuate noise to the local permissible limit. Calculations made during the preparation of environmental impact statements will determine noise abatement requirements either for achieving compliance with local noise limits or for minimizing community annoyance. Several studies were undertaken to provide a noise emission data base for the sound sources associated with both alternatives and to develop procedures for evaluating the effects of environmental noise changes. Noise emissions from two types of coal delivery and handling systems are reviewed since these are expected to be the main sources of noise resulting from coal reconversion of a central power station. Noise emissions from on?site cogenerators which will most likely be diesel engine?generators will be discussed briefly since it was the subject of a prior paper [A. M. Teplitzky and L. N. Miller J. Acoust. Soc. Am. Suppl. 1 67 S87(1980)]. The studies have shown that noise emissions from either alternative are compatible with the urban environment when adequate noise abatement devices are installed.

Allan M. Teplitzky

1981-01-01T23:59:59.000Z

149

An investigation of the noise dynamics in a southern illinois underground coal mine.  

Science Journals Connector (OSTI)

Noise in an underground coal mine has dominant components generated mainly from three sources: (1) continuous mining machine (CMM) (2) roof bolters and (3) cars/vehicles which are transporting personnel end/or coal. Each of these three noise sources also has a number of well defined sub?sources with their own noise characteristics. The CMM noise is comprised mainly of noisegenerated by coal cutting drum wet scrubber for dust control and coal transport conveyor (called also the CMM’s tail). Roof bolter’s noise is generated during the drilling of the roof bolt holes in the bolting process. Personnel and coaltransportationvehiclesgeneratenoise from the power driven system. The personnel most exposed to these noises are operators of these machines and associated support personnel. Three selected techniques with appropriate instrumentation were used to monitor exposure of the personnel to the noise and noise energy over a period of time. The most common technique is based on the use of personal noise dosimeters. The sound level meters (both pressure and power) were also used to collect noise data in form of instantaneous readings and also to check calibration of other sound measuring instruments. Most useful information was obtained from continuous recordings of the noise over time. This paper discusses the variability or dynamics of the generatednoise in both frequency and time domains

Marek Szary; Yoginder Chugh; William Bell; Joseph Hirschi

2010-01-01T23:59:59.000Z

150

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

E-Print Network (OSTI)

SQUID sensors demonstrate the effectiveness of this data consistency constraint and sparsity prior-mail: fhlin@ntu.edu.tw Introduction MRI has become an indispensible resource in clinical medicine because

151

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

E-Print Network (OSTI)

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 ...

Borneman, Troy William

2013-01-01T23:59:59.000Z

152

Ambient noise levels and reverberation times in Mississippi school rooms  

Science Journals Connector (OSTI)

Nine elementary school classrooms at three Mississippi public schools were selected at random for noise and reverberation time measures to monitor voluntary compliance with ANSI standard S12.60-2002 (Acoustical Performance Criteria Design Requirements and Guidelines for Schools). One-hour equivalent dBA noise levels and reverberation times (T60) were measured with SpectraPLUS Version 5.0 software. Measures were taken on separate days at each school in unoccupied classrooms with the HVAC system operating. For ambient noise measures an Audix TR40 omnidirectional microphone was placed in a 12 inch stand on a student's desk near the middle of the room and oriented toward the teacher's desk at a 45 degree angle. For the reverberation time measure a 400 watt loudspeaker (Yamaha BR15M) was placed on the teacher's desk about 3 meters from the microphone. Results showed that noise levels varied from 28 dBA to 51 dBA with broad spectra containing peaks at 120 Hz and harmonics. Five of nine classrooms had noise levels that exceeded the ANSI recommended level of 35 dBA. Reverberation times varied from .21 to .62 seconds; only one classroom exceeded the recommended minimal reverberation time of .6 seconds. Acoustical modifications to reduce noise levels and reverberation times will be addressed.

Edward L. Goshorn; Brett E. Kemker

2012-01-01T23:59:59.000Z

153

Laser Noise Reduction in Air  

E-Print Network (OSTI)

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.

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

2006-08-09T23:59:59.000Z

154

Noise cancellation: disrupting audio perception  

Science Journals Connector (OSTI)

Noise cancellation: disrupting audio perception is an interactive sound and visual art installation that explores the creation of new technology - open-air active signal cancellation - and how it can be incorporated into interactive art installations. As an ongoing collaborative project between artist and engineer, noise cancellation engages signal processing research issues in a creative application space. This paper describes the collaborative installation work in progress and discusses why this active signal cancellation technology is important in relation to changing modes of listening and hearing, altering spatial perception and encouraging audiences to fully interact with art installations within art galleries (and related spaces).

Cara-Ann Simpson; Eva Cheng

2013-01-01T23:59:59.000Z

155

Jet Noise Contribution to Wind Noise in Vehicles  

Science Journals Connector (OSTI)

A source of “wind noise” in a vehicle with a slightly opened window has been modeled as a slit jet issuing from a plenum (idealized vehicle). The nondimensional power spectra measured inside and outside were quite similar; the curves collapsed together well when plotted against Strouhal number fD/U (f=frequency D=slit width U=jet nozzle velocity). The higher frequency sources of the jet noise being closer to the slit subtend a larger angle and would be expected to transmit more noise into the plenum. This expectation was confirmed with inward transmission increasing with both frequency and slit width; at 10 000 Hz and 1.5?in. slit width (maxima for these experiments with 80?fps jet velocity) the jet noise power transmitted inward through the slit reached 68% of the power emitted externally in the 1 3 ? oct band. These were exploratory tests and there was no external wind. [Work supported by Air Force Office of Scientific Research.

C.?K. A. Yu; H. S. Ribner

1971-01-01T23:59:59.000Z

156

Background noise spectra of global seismic stations  

SciTech Connect

Over an extended period of time station noise spectra were collected from various sources for use in estimating the detection and location performance of global networks of seismic stations. As the database of noise spectra enlarged and duplicate entries became available, an effort was mounted to more carefully select station noise spectra while discarding others. This report discusses the methodology and criteria by which the noise spectra were selected. It also identifies and illustrates the station noise spectra which survived the selection process and which currently contribute to the modeling efforts. The resulting catalog of noise statistics not only benefits those who model network performance but also those who wish to select stations on the basis of their noise level as may occur in designing networks or in selecting seismological data for analysis on the basis of station noise level. In view of the various ways by which station noise were estimated by the different contributors, it is advisable that future efforts which predict network performance have available station noise data and spectral estimation methods which are compatible with the statistics underlying seismic noise. This appropriately requires (1) averaging noise over seasonal and/or diurnal cycles, (2) averaging noise over time intervals comparable to those employed by actual detectors, and (3) using logarithmic measures of the noise.

Wada, M.M.; Claassen, J.P.

1996-08-01T23:59:59.000Z

157

Nonlinear Noise in Cosmology  

E-Print Network (OSTI)

This paper derives and analyzes exact, nonlocal Langevin equations appropriate in a cosmological setting to describe the interaction of some collective degree of freedom with a surrounding ``environment.'' Formally, these equations are much more general, involving as they do a more or less arbitrary ``system,'' characterized by some time-dependent potential, which is coupled via a nonlinear, time-dependent interaction to a ``bath'' of oscillators with time-dependent frequencies. The analysis reveals that, even in a Markov limit, which can often be justified, the time dependences and nonlinearities can induce new and potentially significant effects, such as systematic and stochastic mass renormalizations and state-dependent ``memory'' functions, aside from the standard ``friction'' of a heuristic Langevin description. One specific example is discussed in detail, namely the case of an inflaton field, characterized by a Landau-Ginsburg potential, that is coupled quadratically to a bath of scalar ``radiation.'' The principal conclusion derived from this example is that nonlinearities and time-dependent couplings do {\\em not} preclude the possibility of deriving a fluctuation-dissipation theorem, and do {\\em not} change the form of the late-time steady state solution for the system, but {\\em can} significantly shorten the time scale for the approach towards the steady state.

Salman Habib; Henry E. Kandrup

1992-08-13T23:59:59.000Z

158

Noise Levels due to Trains  

Science Journals Connector (OSTI)

Some fifty freight and passenger trains were investigated at distances between 25 and 1000 ft. The decrease of sound?pressure levels with increasing distance indicates that whistles are to be considered as point sources but engines and track noise are line sources out to distances comparable with the lengths of the source. All engines showed a pure tone in the region of 100 cps and freight engines a second tone at about 300 cps when pulling hard. Otherwise freight engines showed little change in level whatever the operating conditions. Noise from passenger engines showed marked changes in level since they operate with much more exaggerated changes in power than freight engines. Track noise depends on the rolling stock—freight cars and run?of?the?mill passenger cars have very similar noise spectra whereas the deluxe cars used on “prestige trains” have spectra lying 10 to 20 db lower in all frequency bands. All the cars have coil springs but the latter alone have hydraulic shock absorbers.

T. F. W. Embleton; G. J. Thiessen

1961-01-01T23:59:59.000Z

159

Simulation of synchrotron motion with rf noise  

SciTech Connect

The theoretical formulation is described that is behind an algorithm for synchrotron phase-space tracking with rf noise and some preliminary simulation results of bunch diffusion under rf noise obtained by actual tracking.

Leemann, B.T.; Forest, E.; Chattopadhyay, S.

1986-08-01T23:59:59.000Z

160

Power supply noise in delay testing  

E-Print Network (OSTI)

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 non-trivial additional...

Wang, Jing

2009-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Sensing Applications of Fluctuations and Noise  

E-Print Network (OSTI)

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...

Chang, Hung-Chih

2011-02-22T23:59:59.000Z

162

Effects of Weapon Noise on Hearing  

Science Journals Connector (OSTI)

...“In military spheres, the need for prevention of weapon noise-induced hearing loss is receiving ever-...

A. Dancer; R. Franke

1986-01-01T23:59:59.000Z

163

LNG carrier underwater noise in Baffin Bay  

Science Journals Connector (OSTI)

Large powerful liquid natural gas carriers may soon ply Arctic waters year round. Concern has been expressed over the impact the resulting noise will have on Arctic marine life. This study includes estimates of LNG carrier?radiated noise source levels and resulting sound levels at a given distance from the ship for a number of operating conditions. Measurements of sound propagation and ambient noise conditions in Baffin Bay are used to estimate the shipnoise levels in relation to the summertime noise background.

L. J. Leggat; H. M. Merklinger; J. L. Kennedy

1981-01-01T23:59:59.000Z

164

Noise Compensation for Subspace Gaussian Mixture Models  

E-Print Network (OSTI)

Noise Compensation for Subspace Gaussian Mixture Models Liang Lu University of Edinburgh Joint work condition (i.e. noise), the gain disappears Goal Noise compensation for SGMM Method Model space compensation . . .· · · · · · · · · · ·· · ·· · ···· · ·· · ·· vjk Liang Lu, Interspeech, September, 2012 R T S C R T S C #12;Noise compensation Larger modelling

Edinburgh, University of

165

Wind?energy farm noise impacts on nearby residences—the citizen's view  

Science Journals Connector (OSTI)

Wind?energy farms with hundreds of wind turbines have proliferated in close proximity to residential properties without any apparent control on the noise impact consequences. Annoying and intrusive wind turbinenoise occurred as soon as the first turbines were installed. The adverse noise impact has continued and intensified as additional WECS (wind energy conversion system) sites were approved and developed with the installation of hundreds of additional turbines. The adverse noiseeffects consist of low?frequency noise that is not fully addressed or controlled by only A?weighted sound level standards pure tones and higher noise levels during higher wind?speed conditions. More stringent noise controls should have been implemented in the beginning. Riverside County has recently adopted a more stringent noise standard that also includes a pure tone restriction that will apply to future sites. However mitigation of the mistakes made at the earlier sites remains to be resolved.

John R. Warner

1986-01-01T23:59:59.000Z

166

Finite-Difference Modeling of Noise Coupling between Power/Ground Planes in Multilayered Packages and Boards  

E-Print Network (OSTI)

system become increasingly more critical regarding the signal integrity and electromagnetic interference electromagnetic interference. Hence, accurate modeling of power/ground planes is critical to estimate the noise

Swaminathan, Madhavan

167

Noise canceling in-situ detection  

DOE Patents (OSTI)

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.

Walsh, David O.

2014-08-26T23:59:59.000Z

168

Automotive friction-induced noises A. Elmaiana  

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

169

Charge Noise in Graphene Transistors Iddo Heller,,  

E-Print Network (OSTI)

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

Dekker, Cees

170

Fast quantum noise in the Landau-Zener transition  

E-Print Network (OSTI)

We show by direct calculation starting from a microscopic model that the two-state system with time-dependent energy levels in the presence of fast quantum noise obeys the master equation. The solution of master equation is found analytically...

Pokrovsky, Valery L.; Sun, D.

2007-01-01T23:59:59.000Z

171

Modeling Microbunching from Shot Noise Using Vlasov Solvers  

SciTech Connect

Unlike macroparticle simulations, which are sensitive to unphysical statistical fluctuations when the number of macroparticles is smaller than the bunch population, direct methods for solving the Vlasov equation are free from sampling noise and are ideally suited for studying microbunching instabilities evolving from shot noise. We review a 2D (longitudinal dynamics) Vlasov solver we have recently developed to study the microbunching instability in the beam delivery systems for x-ray FELs and present an application to FERMI{at}Elettra. We discuss, in particular, the impact of the spreader design on microbunching.

Venturini, Marco; Venturini, Marco; Zholents, Alexander

2008-05-01T23:59:59.000Z

172

Noise in relation to annoyance, performance, and mental health  

Science Journals Connector (OSTI)

There are many psychological factors which cause differences of human response to the same level of sound energy. Nevertheless experiments have allowed these factors to be understood at least to the extent where policy decisions can be made. The results show that increasing levels of noise increase annoyance probably increasing the general arousal or excitability of the nervous system. This gives changes in performance which are sometimes detrimental but not by any means always. Annoyance is associated with psychiatric ill?health but increases in noise do not appear to increase the proportion of people with such illness.

Donald E. Broadbent

1980-01-01T23:59:59.000Z

173

Data series subtraction with unknown and unmodeled background noise  

E-Print Network (OSTI)

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.

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

2014-04-18T23:59:59.000Z

174

Noise?insulation requirements for multi?family dwellings  

Science Journals Connector (OSTI)

Noise insulation standards are part of the California Administrative Code (Title 25 Section 1092). These standards apply to all new multi?family dwelling units such as hotels apartments duplexes townhouses and condominium units. Detached single?family dwellings are specifically excluded. The standards establish minimum requirements for the isolation of interior spaces from exterior noise and set minimum ratings for noise insulation of partitions between dwelling units. A community noise equivalent level (CNEL) of 45 dB is set as the maximum for intrusive noise from exterior sources such as rail or road traffic or aircraft operations. American Society for Testing and Materials (ASTM) testing procedures for party wall and floor/ceiling system sound transmission provide the basis for setting minimum acceptable performance for separations between units. As a consultant to builders planners and architects the site planning and design of residential projects have been examined and field evaluations have been performed on completed projects. Building designs and the selection of suitable building elements (wall construction composites window assemblies vent configurations etc.) which assure compliance with the standards have been identified. The paper provides a brief description of the standards their enforcement pitfalls and an assessment of their impact on residential construction in California.

John J. Van Houten

1981-01-01T23:59:59.000Z

175

A neural network based model for urban noise prediction  

Science Journals Connector (OSTI)

Noise is a global problem. In 1972 the World Health Organization (WHO) classified noise as a pollutant. Since then most industrialized countries have enacted laws and local regulations to prevent and reduce acoustic environmental pollution. A further aim is to alert people to the dangers of this type of pollution. In this context urban planners need to have tools that allow them to evaluate the degree of acoustic pollution. Scientists in many countries have modeled urban noise using a wide range of approaches but their results have not been as good as expected. This paper describes a model developed for the prediction of environmental urban noise using Soft Computing techniques namely Artificial Neural Networks (ANN). The model is based on the analysis of variables regarded as influential by experts in the field and was applied to data collected on different types of streets. The results were compared to those obtained with other models. The study found that the ANN system was able to predict urban noise with greater accuracy and thus was an improvement over those models. The principal component analysis (PCA) was also used to try to simplify the model. Although there was a slight decline in the accuracy of the results the values obtained were also quite acceptable.

N. Genaro; A. Torija; A. Ramos-Ridao; I. Requena; D. P. Ruiz; M. Zamorano

2010-01-01T23:59:59.000Z

176

Coating thermal noise for arbitrary shaped beams  

E-Print Network (OSTI)

Advanced LIGO's sensitivity will be limited by coating noise. Though this noise depends on beam shape, and though nongaussian beams are being seriously considered for advanced LIGO, no published analysis exists to compare the quantitative thermal noise improvement alternate beams offer. In this paper, we derive and discuss a simple integral which completely characterizes the dependence of coating thermal noise on shape. The derivation used applies equally well, with minor modifications, to all other forms of thermal noise in the low-frequency limit.

Richard O'Shaughnessy

2006-10-13T23:59:59.000Z

177

Laser phase noise effects on the dynamics of optomechanical resonators  

E-Print Network (OSTI)

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.

Gregory A. Phelps; Pierre Meystre

2010-11-01T23:59:59.000Z

178

Intrinsic Noise Induced Coherence Resonance in a Glow discharge Plasma  

E-Print Network (OSTI)

Experimental evidence of intrinsic noise induced coherence resonance in a glow discharge plasma is being reported. Initially the system is started at a discharge voltage (DV) where it exhibited fixed point dynamics, and then with the subsequent increase in the DV spikes were excited which were few in number and with further increase of DV the number of spikes as well as their regularity increased. The regularity in the interspike interval of the spikes is estimated using normalized variance (NV). Coherence resonance was determined using normalized variance curve and also corroborated by Hurst exponent and power spectrum plots. We show that the regularity of the excitable spikes in the floating potential fluctuation increases with the increase in the DV, upto a particular value of DV. Using a Wiener filter, we separated the noise component which was observed to increase with DV and hence conjectured that noise can be playing an important role in the generation of the coherence resonance. From an anharmonic osc...

Shaw, Pankaj Kumar; Ghosh, S; Janaki, M S; Iyengar, A N S

2014-01-01T23:59:59.000Z

179

A computer program for HVDC converter station RF noise calculations  

SciTech Connect

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.

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

180

Decoherence suppression via environment preparation  

SciTech Connect

To protect a quantum system from decoherence due to interaction with its environment, we investigate the existence of initial states of the environment allowing for decoherence-free evolution of the system. For a class of models in which a two-state system and a dynamical environment interact through a Hamiltonian restricted to be a tensor product, we prove that such states exist if and only if the interaction and self-evolution Hamiltonians of the environment share an eigenstate. If decoherence by state preparation is not possible, we show that initial states minimizing decoherence result from a delicate compromise between the environment and interaction dynamics.

Landon-Cardinal, Olivier [Departement de Physique, Universite de Montreal, CP 6128, Succ. Centreville, Montreal, Quebec, H3C 3J7 (Canada); Departement IRO, Universite de Montreal, CP 6128, Succ. Centreville, Montreal, Quebec, H3C 3J7 (Canada); MacKenzie, Richard [Departement de Physique, Universite de Montreal, CP 6128, Succ. Centreville, Montreal, Quebec, H3C 3J7 (Canada)

2009-12-15T23:59:59.000Z

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181

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

SciTech Connect

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.

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

182

Application of barrier in industrial noise control  

Science Journals Connector (OSTI)

Noise barriers have been widely used in environmental noisecontrol such as traffic and railway noise. Actually they are also cost?effective mitigation measures in industrial noise control. In this paper the applications of noise barrier in power plant are introduced. Types of barrier and barrier materials are briefly summarized and compared. A case study of noise barrier implement in a 50 MW power plant is presented. The plant is a natural gas?fired simple?cycle peaking facility and consists of two opposed gas combustion turbine directly connected through a coupling to a single generator. Some residences are located around the facility. A noise barrier wall was designed and installed surrounding the facility to control the noiseimpact of the plant on the residences. The acoustic modeling software Cadna/A was used to predict the noise insertion loss of the barrier. The prediction results were also compared with the site measurements.

2005-01-01T23:59:59.000Z

183

Probing cell-free gene expression noise in femtoliter volumes  

SciTech Connect

Cell-free systems offer a simplified and flexible context that enables important biological reactions while removing complicating factors such as fitness, division, and mutation that are associated with living cells. However, cell-free expression in unconfined spaces is missing important elements of expression in living cells. In particular, the small volume of living cells can give rise to significant stochastic effects, which are negligible in bulk cell-free reactions. Here, we confine cell-free gene expression reactions to cell relevant 20 fL volumes (between the volumes of E. coli and S. cerevisiae), in polydimethylsiloxane (PDMS) containers. We demonstrate that expression efficiency varies widely at this volume, and we analyze gene expression noise. Noise analysis reveals signatures of translational bursting while noise dynamics suggest that overall cell-free expression is limited by a diminishing translation rate. In addition to offering a unique approach to understanding noise in gene circuits, our work contributes to a deeper understanding of the biophysical properties of cell-free expression systems, thus aiding efforts to harness cell-free systems for synthetic biology applications.

Karig, David K [ORNL; Jung, Seung-Yong [ORNL; Srijanto, Bernadeta R [ORNL; Collier, Pat [ORNL; Simpson, Michael L [ORNL

2013-01-01T23:59:59.000Z

184

Ising-Glauber Spin Cluster Model for Temperature-Dependent Magnetization Noise in SQUIDs  

Science Journals Connector (OSTI)

Clusters of interacting two-level-systems, likely due to Farbe+(F+) centers at the metal-insulator interface, are shown to self-consistently lead to 1/f? magnetization noise [with ?(T)?1] in SQUIDs. Model calculations, based on a new method of obtaining correlation functions, explains various puzzling experimental features. It is shown why the inductance noise is inherently temperature dependent while the flux noise is not, despite the same underlying microscopics. Magnetic ordering in these systems, established by three-point correlation functions, explains the observed flux- inductance-noise cross correlations. Since long-range ferromagnetic interactions are shown to lead to a more weakly temperature dependent flux noise when compared to short-range interactions, the time reversal symmetry of the clusters is also not likely broken by the same mechanism which mediates surface ferromagnetism in nanoparticles and thin films of the same insulator materials.

Amrit De

2014-11-18T23:59:59.000Z

185

Ion-trap measurements of electric-field noise near surfaces  

E-Print Network (OSTI)

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.

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

2014-09-23T23:59:59.000Z

186

Noise-assisted energy transfer in quantum networks and light-harvesting complexes  

E-Print Network (OSTI)

We provide physically intuitive mechanisms for the effect of noise on excitation energy transfer (EET) in networks. Using these mechanisms of dephasing-assisted transport (DAT) in a hybrid basis of both excitons and sites, we develop a detailed picture of how noise enables energy transfer with efficiencies well above $90%$ across the Fenna-Matthew-Olson (FMO) complex, a type of light harvesting molecule. We demonstrate explicitly how noise alters the pathways of energy transfer across the complex, suppressing ineffective pathways and facilitating direct ones to the reaction centre. We explain that the fundamental mechanisms underpinning DAT are expected to be robust with respect to the considered noise model but show that the specific details of the exciton-phonon coupling, which remain largely unknown in these type of complexes, and in particular the impact of non-Markovian effects, results in variations of dynamical features that should be amenable to experimental verification within current or planned technology. A detailed understanding of DAT in natural compounds should open up a new paradigm of `noise-engineering' by which EET can be optimized in artificial light-harvesting structures.

Alex W. Chin; Animesh Datta; Filippo Caruso; Susana F. Huelga; Martin B. Plenio

2009-10-21T23:59:59.000Z

187

Shot Noise in Ballistic Graphene  

Science Journals Connector (OSTI)

We have investigated shot noise in graphene field effect devices in the temperature range of 4.2–30 K at low frequency (f=600–850??MHz). We find that for our graphene samples with a large width over length ratio W/L, the Fano factor F reaches a maximum F?1/3 at the Dirac point and that it decreases strongly with increasing charge density. For smaller W/L, the Fano factor at Dirac point is significantly lower. Our results are in good agreement with the theory describing that transport at the Dirac point in clean graphene arises from evanescent electronic states.

R. Danneau; F. Wu; M. F. Craciun; S. Russo; M. Y. Tomi; J. Salmilehto; A. F. Morpurgo; P. J. Hakonen

2008-05-13T23:59:59.000Z

188

Optimum information in crackling noise  

Science Journals Connector (OSTI)

The crackling noise due to scratching superhard nanocomposite coatings was investigated by using a simple stick-slip model. The optimum information extracted from statistical analysis, in terms of the Akaike information criterion, is in good agreement with real tests. As a nanocomposite coating approaches an optimal performance, the acoustic emission energy follows a power-law distribution and its behavior is likely to be independent of microscopic and macroscopic details. The results imply that a peculiar deformation behavior, due to the competition between different deformation mechanisms such as dislocation pileups in nanocrystalline grains and grain sliding-grain rotation within amorphous boundaries, plays a vital role in the nanostructure with superhardness.

Chunsheng Lu; Yiu-Wing Mai; Yao-Gen Shen

2005-08-08T23:59:59.000Z

189

An FFT-Based Companding Front End for Noise-Robust Automatic Speech Recognition  

E-Print Network (OSTI)

We describe an FFT-based companding algorithm for preprocessing speech before recognition. The algorithm mimics tone-to-tone suppression and masking in the auditory system to improve automatic speech recognition performance ...

Raj, Bhiksha

190

Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy  

Science Journals Connector (OSTI)

Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent...

Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; Nelson, Johanna; Shapiro, David; Stewart, Andrew; Turner, Joshua; Jacobsen, Chris

2009-01-01T23:59:59.000Z

191

How Can Random Noise Help Us  

E-Print Network (OSTI)

How Can Random Noise Help Us. Global Transports from Thermal Fluctuations. Aaron N. K. Yip. Department of Mathematics. Purdue University. 0. 1. 2. 3. 4. 5. 6.

2009-03-18T23:59:59.000Z

192

Noise exposures in US coal mines  

SciTech Connect

Mine Safety and Health Administration (MSHA) inspectors conduct full-shift environmental noise surveys to determine the occupational noise levels to which coal miners are exposed. These noise surveys are performed to determine compliance with the noise standard promulgated under the Federal Mine Safety and Health Act of 1977. Data from over 60,000 full-shift noise surveys conducted from fiscal year 1986 through 1992 were entered into a computer data base to facilitate analysis. This paper presents the mean and standard deviation of over 60,000 full-shift noise dose measurements for various underground and surface coal mining occupations. Additionally, it compares and contrasts the levels with historical noise exposure measurements for selected coal mining occupations that were published in the 1970`s. The findings were that the percentage of miners surveyed that were subjected to noise exposures above 100%, neglecting personal hearing protectors, were 26.5% and 21.6% for surface and underground mining, respectively. Generally, the trend is that the noise exposures for selected occupations have decreased since the 1970`s.

Seiler, J.P.; Valoski, M.P.; Crivaro, M.A.

1994-05-01T23:59:59.000Z

193

Polyakov-loop suppression of colored states in a quark-meson-diquark plasma  

E-Print Network (OSTI)

A quark-meson-diquark plasma is considered within the PNJL model for dynamical chiral symmetry breaking and restoration in quark matter. Based on a generalized Beth-Uhlenbeck approach to mesons and diquarks we present the thermodynamics of this system including the Mott dissociation of mesons and diquarks at finite temperature. A striking result is the suppression of the diquark abundance below the chiral restoration temperature by the coupling to the Polyakov loop, because of their color degree of freedom. This is understood in close analogy to the suppression of quark distributions by the same mechanism. Mesons as color singlets are unaffected by the Polyakov-loop suppression. At temperatures above the chiral restoration mesons and diquarks are both suppressed due to the Mott effect, whereby the positive resonance contribution to the pressure is largely compensated by the negative scattering contribution in accordance with the Levinson theorem.

Blaschke, D; Buballa, M

2014-01-01T23:59:59.000Z

194

Quantum Noise as an Entanglement Meter  

E-Print Network (OSTI)

Entanglement entropy, which is a measure of quantum correlations between separate parts of a many-body system, has emerged recently as a fundamental quantity in broad areas of theoretical physics, from cosmology and field theory to condensed matter theory and quantum information. The universal appeal of the entanglement entropy concept is related, in part, to the fact that it is defined solely in terms of the many-body density matrix of the system, with no relation to any particular observables. However, for the same reason, it has not been clear how to access this quantity experimentally. Here we derive a universal relation between entanglement entropy and the fluctuations of current flowing through a quantum point contact (QPC) which opens a way to perform a direct measurement of entanglement entropy. In particular, by utilizing space-time duality of 1d systems, we relate electric noise generated by opening and closing the QPC periodically in time with the seminal S = 1/3 log L prediction of conformal field theory.

Israel Klich; Leonid Levitov

2008-06-11T23:59:59.000Z

195

Determination of the accuracy of noise dosimeters used for the evaluation of occupational noise exposure  

E-Print Network (OSTI)

DETERMINATION OF THE ACCURACY OF NOISE DOSIMETERS USED FOR THE EVALUATION OF OCCUPATIONAL NOISE EXPOSURE A Thesis by ROBF. RT DALTON ABEL, JR. Submitted to the Graduate College of Texas ASM University in oartial fulfillment of...' the requirement for the degree of. MASTER OF SCIENCE May 1977 Ma. jor Subject: Industrial Hygiene DETERMINATION OF THE ACCURACY OF NOISE DOSIMETERS USED FOR THE EVALUATION OF OCCUPATIONAL NOISE EXPOSURE A Thesis by ROBERT DALTON ABEL, JR. Approved...

Abel, Robert Dalton

2012-06-07T23:59:59.000Z

196

Active noise within the generating/pumping groups of a large hydroelectric plant  

Science Journals Connector (OSTI)

This work is related to a feasibility study for the implementation of an active noise control system to reduce the hydraulic turbomachine’s noise in the Presenzano power plant. Previous studies showed that interested turbines are low frequencies noise sources generating pure tones at 150 and 200 Hz (third and fourth harmonics of the turbine’s BPF). At these frequencies passive noise control systems are ineffective in front of relevant costs and an active approach was so decided to be tested. In accordance with a classical architecture the preliminary system was composed of four error microphones four secondary noise sources and a digital controller implementing an adaptive digital filter. Main performed activities could be identified through four successive steps: (i) analysis of the turbomachine’s generated primary field levels and space distribution (ii) secondary sources generated noise field measurement ten different loudspeakers locations were investigated at this stage; (iii) sensor and actuator locations’ optimization by the use of a genetic algorithm’s procedure and (iv) active noise control tests. A mean reduction of 15 dB at 150 Hz and 7.5 dB at 200 Hz was measured at the error sensors during these tests revealing the good opportunities of such an approach but also the opportune improvement to pass at a practical implementation.

Leonardo Lecce; Massimo Viscardi; Bruno Maja; Vincenzo Limone; Mario D’Ischia; Francesco Di Maso

1999-01-01T23:59:59.000Z

197

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 on electrochemical noise Rik-Wouter BOSCHa , Robert A. COTTISb,* , Kinga CSECSc , Thomas DORSCHc , Lucia DUNBARd), Switzerland; p) University of Cadiz, Spain. Abstract Sixteen laboratories have performed electrochemical noise

198

Ambient noise levels and reverberation times in Mississippi school rooms.  

Science Journals Connector (OSTI)

Nine elementary schoolclassrooms at three Mississippi public schools were selected at random for noise and reverberation time measures to monitor voluntary compliance with ANSI standard S12.60?2002 (Acoustical Performance Criteria Design Requirements and Guidelines for Schools). 1?h equivalent dBAnoise levels and reverberation times (T60) were measured with SPECTRAPLUS Version 5.0 software.Measures were taken on separate days at each school in unoccupied classrooms with the HVAC system operating. For ambient noisemeasures an Audix TR40 omnidirectional microphone was placed in a 12 in. stand on a student’s desk near the middle of the room and oriented toward the teacher’s desk at a 45 deg angle. For the reverberation time measure a 400 W loudspeaker (Yamaha BR15M) was placed on the teacher’s desk about 3 m from the microphone. Results showed that noise levels varied from 28 to 51 dBA with broad spectra containing peaks at 120 Hz and harmonics. Five of nine classrooms had noise levels that exceeded the ANSI recommended level of 35 dBA. Reverberation times varied from 0.21 to 0.62 s; only one classroom exceeded the recommended minimal reverberation time of 0.6 s. Acoustical modifications to reduce noise levels and reverberation times will be addressed.

Edward L. Goshorn; Megan N. Lucus; Brett E. Kemker

2010-01-01T23:59:59.000Z

199

Suppression of color screening at large N  

Science Journals Connector (OSTI)

In large-N QCD, deconfinement by color screening is suppressed. The adjoint string tension is twice the fundamental string tension. Consequences for models of confinement are discussed, and a simple model of a confining large-N master field is given.

J. Greensite and M. B. Halpern

1983-05-15T23:59:59.000Z

200

Characterization of vehicle noise in Hong Kong  

Science Journals Connector (OSTI)

There is a common perception among residents of high?rise buildings facing expressways that noise emitted from moving vehicles would be dominated by tire/road interaction and at high?frequency regions. Local government officials believe that the impact on residents of low?frequency noise radiated from car engines would be insignificant especially after the corrections for the A?weighting scale are applied. This paper reports on an extensive survey and some in situ sound measurements. It was found that road noise in Hong Kong is dominated by low?frequency noise emitted from heavy vehicles in expressways and by low?frequency noise emitted from heavy and light vehicles driven at a speed below 50 km/h in streets. The measured data were characterized by using time?averaged 1/1 octave band analysis time?averaged 1/3 octave band analysis and time?frequency analysis. The Doppler effect was clearly observed at low?frequency regions in joint time?frequency distributions. It is suggested that the A?weighting scale would not reflect the true annoyance level of traffic noise. Noisiness should be used to quantify the annoyance caused by moving vehicles. A new noise model is proposed to give a realistic description of noise radiated from a moving vehicle.

W. T. Ng; M. M. F. Yuen; W. M. To

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Levels and Spectra of Transportation Vehicle Noise  

Science Journals Connector (OSTI)

In the recent past a program was initiated to survey vehicle traffic and industrial noise in the Chicago area. The phase on noise of vehicles has been completed. The investigation included street elevated and subway cars; diesel steam and electric trains; and motor buses trucks and automobiles.

G. L. Bonvallet

1950-01-01T23:59:59.000Z

202

Effects of carbon nanotubes and graphene oxide absorbers on the noise of mode-locked fiber lasers  

E-Print Network (OSTI)

Phase noise is very important for the ultrafast pulse application in telecommunication, ultrafast diagnose, material science, and biology. In this paper, two types of carbon nano-materials, single-wall carbon nanotube and graphene oxide, are investigated for noise suppression in ultrafast photonics. Various properties of the wall-paper SAs, such as saturable intensity, optical absorption and degree of purity, are found to be key factors determining the phase noise of the ultrafast pulses. A reduced-noise femtosecond fiber laser is experimentally demonstrated by optimizing the above parameters of carbon material based SAs. The phase noise reduction more than 10 dB at 10 kHz can be obtained in the experiments. To our knowledge, this is the first time that the relationship between different carbon material based SAs and the phase noise of mode-locked lasers has been investigated. This work will pave the way to get a high-quality ultrashort pulse in passively mode-locked fiber lasers.

Li, Xiaohui; Yu, Xuechao; Wang, Yonggang; Wang, Yishan; Meng, Bo; Tang, Yulong; Yu, Xia; Zhang, Ying; Sun, Zhipei; Shum, Perry Ping; Wang, Qi Jie

2014-01-01T23:59:59.000Z

203

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

SciTech Connect

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.

Long, M.; Stern, R.

1982-01-01T23:59:59.000Z

204

Probability Density Function Method for Langevin Equations with Colored Noise  

SciTech Connect

We present a novel method to derive closed-form, computable PDF equations for Langevin systems with colored noise. The derived equations govern the dynamics of joint or marginal probability density functions (PDFs) of state variables, and rely on a so-called Large-Eddy-Diffusivity (LED) closure. We demonstrate the accuracy of the proposed PDF method for linear and nonlinear Langevin equations, describing the classical Brownian displacement and dispersion in porous media.

Wang, Peng; Tartakovsky, Alexandre M.; Tartakovsky, Daniel M.

2013-04-05T23:59:59.000Z

205

Squeezing in driven bimodal Bose-Einstein condensates: Erratic driving versus noise  

Science Journals Connector (OSTI)

We study the interplay of squeezing and phase randomization near the hyperbolic instability of a two-site Bose-Hubbard model in the Josephson interaction regime. We obtain results for the quantum Zeno suppression of squeezing far beyond the previously found short time behavior. More importantly, we contrast the expected outcome with the case where randomization is induced by erratic driving with the same fluctuations as the quantum noise source, finding significant differences. These are related to the distribution of the squeezing factor, which has log-normal characteristics: hence its average is significantly different from its median due to the occurrence of rare events.

Christine Khripkov; Amichay Vardi; Doron Cohen

2012-05-24T23:59:59.000Z

206

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

E-Print Network (OSTI)

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.

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

2010-05-25T23:59:59.000Z

207

Suppression of Stable Flies on Cattle  

E-Print Network (OSTI)

populations is sanitation. In confined animal facilities, a top priority should be to eliminate stable fly breeding sites as often as possible. To do this, remove and spread decomposing vegetation or bedding material that has become mixed with urine and feces... but in concert with other meth- ods, such as sanitation. Chemical control: If a stable fly problem persists, an insecticide can be used. Many compounds are available for suppressing adult and larval stable fly populations. Animals can be treated as needed...

Tomberlin, Jeffery K.

2004-07-01T23:59:59.000Z

208

A programmable analog Gaussian noise generator for test applications.  

E-Print Network (OSTI)

??This thesis presents a robust programmable analog Gaussian noise generator suitable for mixed-signal test applications. Unlike conventional methods, noise generators employing a linear feedback shift… (more)

Aouini, Sadok.

2006-01-01T23:59:59.000Z

209

Improved Prediction of Runway Usage for Noise Forecast :.  

E-Print Network (OSTI)

??The research deals with improved prediction of runway usage for noise forecast. Since the accuracy of the noise forecast depends on the robustness of runway… (more)

Dhanasekaran, D.

2014-01-01T23:59:59.000Z

210

Blue whale response to underwater noise from commercial ships  

E-Print Network (OSTI)

to investigate the effect of ship traffic on ambient noiseThis study investigates the effect of ship noise on signalmaneuvering effects on a surface ship underwater acoustic

McKenna, Megan Frances

2011-01-01T23:59:59.000Z

211

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...

212

Offshore pile driving noise—Prediction through comprehensive model development  

Science Journals Connector (OSTI)

Offshore wind energy is one of the most potent among renewables and thus the worldwide number of offshore wind turbines increases rapidly. The foundations of the wind turbines are typically fastened to the seabed by impact pile driving which comes along with a significant amount of waterborne noise. To protect the marine biosphere the use of noise mitigation systems like bubble curtains or cofferdams may become necessary. In this context the model-based prediction of underwater sound pressure levels as well as the design and optimization of effective sound mitigation measures by using numerical models is one of today’s challenges. The current work presents a modeling approach that consists of a near field finite element model and a far field propagation model. Furthermore it has been found necessary to generate a benchmark to allow for a qualitative and quantitative comparison between the manifold modeling approaches that are currently developed at various institutes and companies.

Marcel Ruhnau; Stephan Lippert

2013-01-01T23:59:59.000Z

213

Active Vibration Suppression of a Smart Beam Cem ONAT+,*  

E-Print Network (OSTI)

1 Active Vibration Suppression of a Smart Beam via PI Dµ Control Cem ONAT+,* , Melin SAHIN* , Yavuz controller was designed for the active vibration suppression of a smart beam equipped with PZT (Lead successfully suppressed the vibration levels of the smart beam for the first two flexural modes. Keywords

Yaman, Yavuz

214

Spectral resolvability of iterated rippled noise  

Science Journals Connector (OSTI)

A forward?masking experiment was used to estimate the spectral ripple of iterated rippled noise (IRN) that is possibly resolved by the auditory system. Tonal signals were placed at spectral peaks and valleys of IRN maskers for a wide variety of IRN conditions that included different delays number of iterations and stimulus durations. The differences in the forward?masked thresholds of tones at spectral peaks and valleys were used to estimate spectral resolvability and these results were compared to estimates obtained from a gamma?tone filter bank. The IRN spectrum has spectral peaks that are harmonics of the reciprocal of the delay used to generate IRN stimuli. As the number of iterations in the generation of IRN stimuli increases so does the difference in the spectral peak?to?valley ratio. For high number of iterations long delays and long durations evidence for spectral resolvability existed up to the 6th harmonic. For all other conditions spectral resolvability appeared to disappear at harmonics lower than the 6th or was not measurable at all. These data will be discussed in terms of the role spectral resolvability might play in processing the pitch pitch strength and timbre of IRN stimuli. [Work supported by a grant from NIDCD.

2005-01-01T23:59:59.000Z

215

The new standard’s HVAC background noise requirements and their implementation in building design  

Science Journals Connector (OSTI)

The new ANSI classroom standard recommends long?term steady?state background sound level limits of 35 dBA and 55 dBC. Since the HVAC system is typically a room’s dominant steady?state noise source it is usually reasonable to apply these limits to the design of the system assuming that other noise sources produce insignificant additions to the room’s long?term background noise environment. The recommended sound level limits are significantly lower than current industry standards and complying with them will increase system costs. School administrators architects and HVAC system designers should therefore be prepared for the changes. This paper summarizes equipment selection and system design guidelines that have been found to be necessary for ensuring compliance with the sound level limits.

2001-01-01T23:59:59.000Z

216

Infrasonic sea noise at the Mid?Atlantic Ridge near 37 °N  

Science Journals Connector (OSTI)

Underwater ambient noise spectra spectrum levels and statistics are described for data continuously recorded in the 5–32?Hz band for 176 h. These measurements were made using two ocean bottom seismographs located in 2478 m of water within the seismically active median valley of the Mid?Atlantic Ridge near 37 °N. Laboratory tests of the H?38 hydrophone show that flow noise levels developed by a 0.3 knot current—the maximum speed anticipated in the median valley—did not exceed the electronic noise level of the recording instrument. Over 500 underwater earthquakes were detected and epicenters were estimated to lie within about 20 km of the instruments. Seismic disturbances raised noise levels at least 20 dB across the acoustic band varied in local magnitude from 1.2 to 2.5 persisted for as long as 2 min and occurred on the average of 2.9 events/h. Sound pressure spectrum levels averaged over the entire recording period and compared to shipping noise curves proposed by Wenz and Urick infer that infrasonic and low?frequency noise are dominated by distant shipping traffic noise. [This work was sponsored by Naval Electronics Systems Command Code 320.

J. R. McGrath

1975-01-01T23:59:59.000Z

217

NASA Subsonic Jet Transport Noise Reduction Research  

Science Journals Connector (OSTI)

Although new jet transport airplanes in today''s fleet are considerably quieter than the first jet transports introduced about 40 years ago, airport community noise continues to be an important environmental issue. NASA''s Advanced Subsonic Transport ...

Powell Clemans A.; Preisser John S.

2000-08-01T23:59:59.000Z

218

Information and noise in quantum measurement  

Science Journals Connector (OSTI)

Even though measurement results obtained in the real world are generally both noisy and continuous, quantum measurement theory tends to emphasize the ideal limit of perfect precision and quantized measurement results. In this article, a more general concept of noisy measurements is applied to investigate the role of quantum noise in the measurement process. In particular, it is shown that the effects of quantum noise can be separated from the effects of information obtained in the measurement. However, quantum noise is required to “cover up” negative probabilities arising as the quantum limit is approached. These negative probabilities represent fundamental quantum-mechanical correlations between the measured variable and the variables affected by quantum noise.

Holger F. Hofmann

2000-07-06T23:59:59.000Z

219

Solving the inverse problem of noise-driven dynamic networks  

E-Print Network (OSTI)

Nowadays massive amount of data are available for analysis in natural and social systems. Inferring system structures from the data, i.e., the inverse problem, has become one of the central issues in many disciplines and interdisciplinary studies. In this Letter, we study the inverse problem of stochastic dynamic complex networks. We derive analytically a simple and universal inference formula called double correlation matrix (DCM) method. Numerical simulations confirm that the DCM method can accurately depict both network structures and noise correlations by using available kinetic data only. This inference performance was never regarded possible by theoretical derivation, numerical computation and experimental design.

Zhang, Zhaoyang; Niu, Haijing; Mi, Yuanyuan; Wu, Si; Hu, Gang

2014-01-01T23:59:59.000Z

220

Quantum capacity of channel with thermal noise  

E-Print Network (OSTI)

The quantum capacity of thermal noise channel is studied. The extremal input state is obtained at the postulation that the coherent information is convex or concave at its vicinity. When the input energy tends to infinitive, it is verified by perturbation theory that the coherent information reaches its maximum at the product of identical thermal state input. The quantum capacity is obtained for lower noise channel and it is equal the one shot capacity.

Xiao-yu Chen

2006-02-11T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

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.

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

2011-09-30T23:59:59.000Z

222

Excess optical quantum noise in atomic sensors  

E-Print Network (OSTI)

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.

Irina Novikova; Eugeniy E. Mikhailov; Yanhong Xiao

2014-10-14T23:59:59.000Z

223

Improved real-time method for noise reduction of directional Doppler audio signals  

Science Journals Connector (OSTI)

A noise reduction filter for Doppler audio signals is one important part of Transcranial Doppler ultrasound system. Several studies have been carried out for low-pass filter with fixed value for Doppler audio signals; however, most of these studies lacked complex research works and few studies analyzed the relationship of both parts of spectrum signal processing and audio signal processing. To solve the above-mentioned concern, this research is focused on the algorithms of de-noising and enveloping of spectrum signal processing part and improved new real-time method, which reduces the noise using low-pass filter with a variable threshold value based on maximum frequency of spectrum signals. The noise of Doppler audio signals was reduced efficiently by using this algorithm.

Erdenedalai Naranchimeg; Byambasuren Bat-Erdene; Seung-Moo Han

2012-01-01T23:59:59.000Z

224

Graduate studies in acoustics and noise control in the School of Mechanical Engineering at Purdue University  

Science Journals Connector (OSTI)

The acoustics community at Purdue University will be described with special emphasis on the graduate program in Mechanical Engineering (ME). Purdue is home to around 30 faculty who study various aspects of acoustics and related disciplines and so there are many classes to choose from as graduate students structure their plans of study to complement their research activities and to broaden their understanding of the various aspects of acoustics. In Mechanical Engineering the primary emphasis is on understanding noise generation noise propagation and the impact of noise on people as well as development of noise control strategies experimental techniques and noise and noise impact prediction tools. The ME acoustics research is conducted at the Ray W. Herrick Laboratories which houses several large acoustics chambers that are designed to facilitate testing of a wide array mechanical systems reflecting the Laboratories’ long history of industry-relevant research. Complementing the acoustics research Purdue has vibrations dynamics and electromechanical systems research programs and is home to a collaborative group of engineering and psychology professors who study human perception and its integration into engineering design. There are also very strong ties between ME acoustics faculty and faculty in Biomedical Engineering and Speech Language and Hearing Sciences.

2014-01-01T23:59:59.000Z

225

Adjuvant Ovarian Suppression in Premenopausal Breast Cancer  

Science Journals Connector (OSTI)

...anticipated, and the rate of disease-free survival was higher than expected. A protocol amendment to the analysis plan was adopted in 2011, designating the test of the superiority of tamoxifen plus ovarian suppression over tamoxifen alone as the primary analysis for SOFT. We calculated that with an estimated... Adjuvant endocrine therapy with tamoxifen has been recommended for premenopausal women with hormone-receptor–positive breast cancer (positive for estrogen receptor, progesterone receptor, or both) during the past 15 years.1,2 The value of therapeutic ...

2014-12-11T23:59:59.000Z

226

Cross-spectrum Analyzer for Low Frequency Noise Analysis  

E-Print Network (OSTI)

The design and performance of a sensitive and reliable cross-correlation spectrum analyzer for studying low frequency transport noise is described in detail. The design makes use of common PC-based data acquisition hardware and preamplifiers to acquire time-based data, along with software we have developed to compute the cross-correlation and noise spectral density. The impedance of device under test may cover four decades from ${100\\,{\\Omega}}$ to ${1\\,{\\mathrm{M}\\Omega}}$. By utilizing a custom developed signal processing program, this system is tested to be accurate and efficient for measuring voltage noise as low as $\\sim\\!10^{-19}\\,\\mathrm{V}^2/\\mathrm{Hz}$ from ${0.001\\,}$Hz to ${100\\,}$kHz within one day's averaging time, comparable with more expensive hardware solutions (bandwidth in real measurements may be limited by the sample impedance and stray capacitance). The time dependence of measurement sensitivity is discussed theoretically and characterized experimentally to optimize between measuring tim...

Zhong, Xing; Jones, Josh; Mewes, Claudia; LeClair, Patrick R

2014-01-01T23:59:59.000Z

227

Military noise limits: Design criteria versus operational effectiveness  

Science Journals Connector (OSTI)

Noise requirements in military environments differ significantly from typical industrial or occupational situations. Both in combat and in training mission success requires offensive equipment and weapons to be more lethal and survivable than those used by the adversary. Higher muzzle velocities heavier projectiles and more powerful engines result in high levels of both steady-state and impulsive noise and an increased risk of hearing loss for the users. Weapons firing can expose the user to more energy in a single event than typically experienced in a working lifetime of occupational exposure. In addition military operations require effective speech communication while minimizing auditory detection of equipment by the adversary. Producing material suitable for various forms of military operations requires unique design criteria often exceeding civilian national or international standards. To meet these unique and often contradicting requirements the U.S. military developed a military design standard for noise limits. This standard (MIL-STD-1474) was last revised in 1997. This paper describes the effort of the U.S. Army Navy and Air Force to update the standard to permit production and fielding of military systems designed to maximize Warfighter effectiveness while minimizing hearing damage caused by their use.

2014-01-01T23:59:59.000Z

228

Artificial neural networks in bias dependant noise modeling of MESFETs  

Science Journals Connector (OSTI)

An efficient procedure for accurate noise parameter prediction of microwave MESFETs / HEMTs for various bias conditions is proposed in this paper. It is based on an improved Pospieszalski's noise model. The bias dependences of the noise model elements ... Keywords: MESFET, artificial neural network, bias, noise modeling

Zlatica Marinkovic; Olivera Pronic-Ran?ic; Vera Markovic

2009-08-01T23:59:59.000Z

229

Noise impact assessment by utilizing noise map and GIS: A case study in the city of Chungju, Republic of Korea  

Science Journals Connector (OSTI)

In this study, a scheme to develop a noise map and noise impact assessment method using GIS has been suggested. After developing a road-traffic noise map for the city of Chungju, Republic of Korea, noise impact assessment was performed through analyzing the map. A 3-dimensional terrain model was generated using digital maps and building models were prepared using the information from draft and digital maps. To develop a noise evaluation model, a noise-source map for each road was generated. The noise levels at 25 locations close to roads were measured and compared with the expected noise levels to verify the developed noise map. An excess noise map was generated by comparing the road-traffic noise map with a noise-standard map. Using the excess noise map, the areas exceeding environmental noise standards were effectively evaluated through a GIS space analysis. The 3-dimensional facade noise map was generated to calculate the number of people exposed to a certain noise level.

Joon Hee Ko; Seo Il Chang; Byung Chan Lee

2011-01-01T23:59:59.000Z

230

Functional link artificial neural network applied to active noise control of a mixture of tonal and chaotic noise  

Science Journals Connector (OSTI)

Many practical noises emanating from rotating machines with blades generate a mixture of tonal and the chaotic noise. The tonal component is related to the rotational speed of the machine and the chaotic component is related to the interaction of the ... Keywords: Active noise control (ANC), Chaotic noise, Functional link artificial neural network (FLANN), Hybrid ANC, Narrowband ANC

Santosh Kumar Behera, Debi Prasad Das, Bidyadhar Subudhi

2014-10-01T23:59:59.000Z

231

Noise and structural dynamics test facilities at Boeing  

Science Journals Connector (OSTI)

The noise and structural dynamics laboratories at Boeing provide a wide range of test and measurement services to the Boeing Company. Test data from these laboratories support all phases of the product life cycle across a diverse line of products and applications. The noise laboratory facilities include a low?speed free?jet acoustic wind tunnel several anechoic and reverberation test chambers a critical listening facility and a materials test center. These facilities are supported with a network of data systems for in?lab testing and a variety of transportable data systems for field? and airplane?based testing. Structural dynamics laboratory facilities include large strongbacks and structural floors for component vibration testing sonic fatigue test facilities and vibration test facilities. These facilities are supported by a network of dedicated data systems for a wide range of modal shock vibration and fatigue testing. Field tests are supported by a wide range of portable data systems and instrumentation trailers capable of large channel count measurements. This work will provide an overview of the test facilities and measurement capabilities of these laboratories.

2001-01-01T23:59:59.000Z

232

Purcell effect with microwave drive: Suppression of qubit relaxation rate  

E-Print Network (OSTI)

We analyze the Purcell relaxation rate of a superconducting qubit coupled to a resonator, which is coupled to a transmission line and pumped by an external microwave drive. Considering the typical regime of the qubit measurement, we focus on the case when the qubit frequency is significantly detuned from the resonator frequency. Surprisingly, the Purcell rate decreases when the strength of the microwave drive is increased. This suppression becomes significant in the nonlinear regime. In the presence of the microwave drive, the loss of photons to the transmission line also causes excitation of the qubit; however, the excitation rate is typically much smaller than the relaxation rate. Our analysis also applies to a more general case of a two-level quantum system coupled to a cavity.

Eyob A. Sete; Jay M. Gambetta; Alexander N. Korotkov

2014-01-22T23:59:59.000Z

233

Environmental noise impact of modern wind farms  

Science Journals Connector (OSTI)

Electric power production from wind turbines has increased substantially during the past few years due to the growing emphasis on renewable energy sources and more efficient wind turbine technology. Although modern turbines are significantly quieter than early models wind farms that are proposed near residential areas generate concern about potential noise issues. The present study consists of two parts: (1) the measurement of sound levels within a 2?km radius of the existing Nine Canyons wind farm near Richland WA and (2) the application of an outdoor sound propagation model to predict noise levels both at Nine Canyons and in the vicinity of a proposed farm near Ellensburg WA. At most locations within the Nine Canyon site recorded sound levels were less than predicted levels with the exception of some downwind sites that were lower in elevation than the source. Noise levels were greatest downwind from the turbines but never exceeded 50 dBA beyond 500 m from the nearest turbine. In many cases wind noise at the microphone exceeded noise levels from the turbines.

2004-01-01T23:59:59.000Z

234

Flux noise in high-temperature superconductors  

Science Journals Connector (OSTI)

Spontaneously created vortex-antivortex pairs are the predominant source of flux noise in high-temperature superconductors. In principle, flux noise measurements allow to check theoretical predictions for both the distribution of vortex-pair sizes and for the vortex diffusivity. In this paper the flux-noise power spectrum is calculated for the highly anisotropic high-temperature superconductor Bi2Sr2CaCu2O8+?, both for bulk crystals and for ultrathin films. The spectrum is basically given by the Fourier transform of the temporal magnetic-field correlation function. We start from a Berezinskii-Kosterlitz-Thouless-type theory and incorporate vortex diffusion, intrapair vortex interaction, and annihilation of pairs by means of a Fokker-Planck equation to determine the noise spectrum below and above the superconducting transition temperature. We find white noise at low frequencies ? and a spectrum proportional to 1/?3/2 at high frequencies. The crossover frequency between these regimes strongly depends on temperature. The results are compared with earlier results of computer simulations.

Carsten Timm

1997-02-01T23:59:59.000Z

235

Behavioral Simulation Techniques for Substrate Noise Analysis in PLL Jae Wook Kim  

E-Print Network (OSTI)

@gloworm.stanford.edu Abstract- This paper presents a methodology to simulate, at the system level, the substrate noise coupling. The simulation of PLLs requires transient analysis with small time-steps over long intervals in order to achieve to simulate the system in a coarse but fast way in order to gain initial design guidance. For example, speed

Dutton, Robert W.

236

TOWARDS NON-STATIONARY MODEL-BASED NOISE ADAPTATION FOR LARGE VOCABULARY SPEECH RECOGNITION  

E-Print Network (OSTI)

recognition systems are known to degrade substantially when there is a mismatch between training of a new environment, ar- tificially mix this noise signal with the training set, and re- train the system, and omission of cross terms when performing the power operation. In the power spectrum domain, finding

Frey, Brendan J.

237

Entanglement-assisted Enhanced Information Transmission Over a Quantum Channel with Correlated Noise; A General Expression  

E-Print Network (OSTI)

Entanglement and entanglement-assisted are useful resources to enhance the mutual information of the Pauli channels, when the noise on consecutive uses of the channel has some partial correlations. In this paper, We study quantum communication channels with correlated noise and derive a general expression for the mutual information of quantum channel, for the product, maximally entangled state coding and entanglement-assisted systems with correlated noise in the Pauli quantum channels. Hence, we suggest more efficient coding in the entanglement-assisted systems for the transmission of classical information and derive a general expression for the entanglement-assisted classical capacity. Our results show that in the presence of memory, a higher amount of classical information is transmitted by two or four consecutive uses of entanglement-assisted systems.

A. Fahmi

2006-05-04T23:59:59.000Z

238

Genetic noise control via protein oligomerization  

SciTech Connect

Gene expression in a cell entails random reaction events occurring over disparate time scales. Thus, molecular noise that often results in phenotypic and population-dynamic consequences sets a fundamental limit to biochemical signaling. While there have been numerous studies correlating the architecture of cellular reaction networks with noise tolerance, only a limited effort has been made to understand the dynamical role of protein-protein associations. We have developed a fully stochastic model for the positive feedback control of a single gene, as well as a pair of genes (toggle switch), integrating quantitative results from previous in vivo and in vitro studies. In particular, we explicitly account for the fast protein binding-unbinding kinetics, RNA polymerases, and the promoter/operator sequences of DNA. We find that the overall noise-level is reduced and the frequency content of the noise is dramatically shifted to the physiologically irrelevant high-frequency regime in the presence of protein dimerization. This is independent of the choice of monomer or dimer as transcription factor and persists throughout the multiple model topologies considered. For the toggle switch, we additionally find that the presence of a protein dimer, either homodimer or heterodimer, may significantly reduce its intrinsic switching rate. Hence, the dimer promotes the robust function of bistable switches by preventing the uninduced (induced) state from randomly being induced (uninduced). The specific binding between regulatory proteins provides a buffer that may prevent the propagation of fluctuations in genetic activity. The capacity of the buffer is a non-monotonic function of association-dissociation rates. Since the protein oligomerization per se does not require extra protein components to be expressed, it provides a basis for the rapid control of intrinsic or extrinsic noise. The stabilization of phenotypically important toggle switches, and nested positive feedback loops in general, is of direct implications to organism fitness. Finally, noise control through oligomerization suggests avenues for the design of robust synthetic gene circuits for engineering purposes.

Ghim, C; Almaas, E

2008-06-12T23:59:59.000Z

239

Comparison of measurement indices of noise intrusions in multi?family housing  

Science Journals Connector (OSTI)

Methods for measuring sound levels associated with transportation impact and airborne sound intrusions in multi?family housing are well established in the field. This paper compares field testing of assemblies where complaints and retrofits have been involved where traditional assessments of intruding noises showed compliance with design criteria but where residents and/or building owners perceived problems. Case study 1 involves noise from airplanes approaching a runway at a large international airport as heard in an all?glass high?rise condominium evaluated by LDNs and SELs of actual flyovers in computer models and in a full size mock?up of a typical unit built on site. Case study 2 involves noise from outdoor amplified entertainment propagating into neighborhoods as evaluated by various noise ordinance criteria. Case study 3 involves footstep noise through flooring systems comparing IIC ratings with actual sound pressure levels of people walking on floors above. Case study 4 compares noise and vibration levels for various pieces of mechanical equipment before and after retrofit with NC RC and other room criteria. Auralizations of the case studies will be shown along with measurement data to illustrate the diagnostics made in each case.

2006-01-01T23:59:59.000Z

240

Amplitude modulation of wind turbine noise  

E-Print Network (OSTI)

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).

Makarewicz, Rufin

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

KdV Preserves White Noise  

E-Print Network (OSTI)

It is shown that white noise is an invariant measure for the Korteweg-deVries equation on $\\mathbb T$. This is a consequence of recent results of Kappeler and Topalov establishing the well-posedness of the equation on appropriate negative Sobolev spaces, together with a result of Cambronero and McKean that white noise is the image under the Miura transform (Ricatti map) of the (weighted) Gibbs measure for the modified KdV equation, proven to be invariant for that equation by Bourgain.

Jeremy Quastel; Benedek Valko

2006-11-06T23:59:59.000Z

242

Infrasonic ambient ocean noise: Northeast Pacific Ocean  

Science Journals Connector (OSTI)

Measurements of ocean ambient noise were made at three widely separated deep?water bottom locations in the N. E. Pacific at eight frequencies in the range from 2.5–20.0 Hz for 40 consecutive days. Concurrent data on wind speed and wave height were collected. Analysis indicates that the spectrum level of infrasonicnoise is linearly related to the log of the wind speed above a threshold level. There is evidence that the noise can be directly associated with the wind rather than through the surface waves it produces. [Work supported by ONR.

Rudolph H. Nichols

1985-01-01T23:59:59.000Z

243

SEY_suppression_ELCOUD04.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 SLAC-TN-04-045 June 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Suppression of the Effective Secondary Emission Yield for a Grooved Metal Surface G. Stupakov and M. Pivi

244

Environmental noise of a nuclear power plant and its substations  

Science Journals Connector (OSTI)

In order to fulfill government requirements for construction of a nuclear power plant an environmental noiseimpact as?assessment has been conducted. Ambient noise was measured continuously for 24 hour periods at the plant and substation sites and in the vicinity. Week long surveys were performed in each of the four seasons. A statistical interpretation of construction noise accounts for variability of construction equipment usage its location and range of sound pressure levels. Histograms of construction noise and measured ambient noise are added to obtain the statistical representation of the predicted construction ambient noise. Operational noise of the plant is similarly predicted. The predicted noise contours of both operation and construction noise are formulated on the topographic maps. Meteorologic and topographic effects on the noise data are discussed.

E. E. Dennison; R. E. Maier; J. W. McGaughey; S. P. Ying

1976-01-01T23:59:59.000Z

245

A spray-suppression model for turbulent combustion  

SciTech Connect

A spray-suppression model that captures the effects of liquid suppressant on a turbulent combusting flow is developed and applied to a turbulent diffusion flame with water spray suppression. The spray submodel is based on a stochastic separated flow approach that accounts for the transport and evaporation of liquid droplets. Flame extinguishment is accounted for by using a perfectly stirred reactor (PSR) submodel of turbulent combustion. PSR pre-calculations of flame extinction times are determined using CHEMKIN and are compared to local turbulent time scales of the flow to determine if local flame extinguishment has occurred. The PSR flame extinguishment and spray submodels are incorporated into Sandia's flow fire simulation code, VULCAN, and cases are run for the water spray suppression studies of McCaffrey for turbulent hydrogen-air jet diffusion flames. Predictions of flame temperature decrease and suppression efficiency are compared to experimental data as a function of water mass loading using three assumed values of drop sizes. The results show that the suppression efficiency is highly dependent on the initial droplet size for a given mass loading. A predicted optimal suppression efficiency was observed for the smallest class of droplets while the larger drops show increasing suppression efficiency with increasing mass loading for the range of mass loadings considered. Qualitative agreement to the experiment of suppression efficiency is encouraging, however quantitative agreement is limited due to the uncertainties in the boundary conditions of the experimental data for the water spray.

DESJARDIN,PAUL E.; TIESZEN,SHELDON R.; GRITZO,LOUIS A.

2000-02-14T23:59:59.000Z

246

Underwater noise generated by Columbia River hydroelectric dams  

Science Journals Connector (OSTI)

Low?frequency (10–1000 Hz) underwater noise measurements have been made in water within and upstream from four Columbia River hydroelectric dams. The motivation for these measurements was to map out the sound field within and upstream from the power dams as a first step in understanding the effect of this field on the behavior of migrating salmonids that must choose between the bypass system or intakes to the turbines. Eventually sound may be used to guide the juvenile fish safely past the turbine intakes and into the bypass system. Thus far single hydrophonemeasurements have been made in the bypass slots within the dam and at a number of locations upstream from the dam. The noise level varies with location decreasing as the hydrophone is moved upsteam from the dam and as the hydrophone is moved closer to the water surface immediately upstream of the dam as well as in the bypass slot. The noise spectra below 200 Hz are highly modulated displaying one or more sharp peaks which indicates resonances in the structural generating mechanism or propagation path. The spectrum level and modulation vary significantly from one dam to another and sometimes from one configuration to another (e.g. when one of the turbines is on or off). A final set of measurements will be made at the Bonneville Dam using several hydrophones placed at a number of locations in the vicinity of the intake channel and these may help identify sources and propagation paths to the hydrophone. [Work sponsored by U. S. Army Corps of Engineers.

Robert T. Miyamoto; Steven O. McConnell; James J. Anderson; Blake E. Feist

1989-01-01T23:59:59.000Z

247

Acoustic Array Development for Wind Turbine Noise Characterization  

SciTech Connect

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.

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

2013-11-01T23:59:59.000Z

248

Autoassociative neural networks and noise filtering  

Science Journals Connector (OSTI)

We introduce linear autoassociative neural (AN) network filters for the removal of additive noise from one-dimensional (1-D) time series. The AN network will have a (2M+1)×L×(2M+1) architecture, and for M fixed, we show how to choose ...

J.R. Dorronsoro; V. Lopez; C.S. Cruz; J.A. Siguenza

2003-05-01T23:59:59.000Z

249

Participatory noise pollution monitoring using mobile phones  

Science Journals Connector (OSTI)

Noise pollution is a major problem in cities around the world. The current methods to assess it neglect to represent the real exposure experienced by the citizens themselves, and therefore could lead to wrong conclusions and a biased representations. ... Keywords: Environmental policy, Web 2.0, citizen science, mobile phones, participatory sensing, pollution measurement

Nicolas Maisonneuve; Matthias Stevens; Bartek Ochab

2010-04-01T23:59:59.000Z

250

Quantum noise of white light cavity using double-pumped gain medium  

E-Print Network (OSTI)

Laser interferometric gravitational-wave detectors implement Fabry-Perot cavities to increase their peak sensitivity. However, this is at cost of reducing their detection bandwidth, which origins from the propagation phase delay of the light. The "white-light-cavity" idea, first proposed by Wicht et al. [Optics Communications 134, 431 (1997)], is to circumvent this limitation by introducing anomalous dispersion, using double-pumped gain medium, to compensate for such phase delay. In this article, starting from the Hamiltonian of atom-light interaction, we apply the input-output formalism to evaluate the quantum noise of the system. We find that apart from the additional noise associated with the parametric amplification process noticed by others, the stability condition for the entire system poses an additional constraint. Through surveying the parameter regimes where the gain medium remains stable (not lasing) and stationary, we find that there is no net enhancement of the shot-noise limited sensitivity. The...

Ma, Yiqiu; Zhao, Chunnong; Chen, Yanbei

2015-01-01T23:59:59.000Z

251

Ocean acoustic noise budgets: Application to the environmental assessment of offshore wind power generation.  

Science Journals Connector (OSTI)

A noise budget is a listing of the various sources of acoustic noise and their associated ranking by importance. A number of different types of budgets can be conceived using various acoustic measures such as intensity energy or duration of maximum amplitude level. These budgets are typically parameterized by frequency and are usually computed over 1/3 octave bands. As part of the environmental assessment of the proposed offshore wind powergeneration project under the Rhode Island Special Area Management Plan (SAMP) noise measurements were made using the Passive Acoustic Listener (PAL) systems off the coast of Rhode Island prior to the installation of any wind power facilities. Two PALs were deployed within two miles of Block Island in water depths of 20 m from October 6 to November 11 2008. The data included noise spectra and source identification every 3 min. Short snapshots of unusual sounds were also recorded. From this data the ocean acoustic noise budget is computed with contributions from shipping wind/waves marine mammals and rain from 500 Hz to 50 kHz. The shipnoise data is correlated with ship traffic data from the Automatic Identification System (AIS). [Funding provided by the Rhode Island Office of Energy Resources.

2009-01-01T23:59:59.000Z

252

Active noise control of supersonic impinging jet using pulsed microjets  

E-Print Network (OSTI)

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 ...

Hong, Seung Hyuck

2009-01-01T23:59:59.000Z

253

Characterization of classroom noise and noise control techniques and their effect on speech comprehension while learning.  

Science Journals Connector (OSTI)

Classrooms have been shown to be prone to elevated occupied noise levels that reduce speech comprehension and inhibit learning. This presentation discusses a current study that includes three parts: (1) the characterization of masking invoked by noise commonly found in today’s classrooms (2) the formulation of a metric that intends to associate masking risk to noise features and (3) the attempt to quantify any increase in speech comprehension resulting from interior acoustic designs that aspire to reduce noise in occupied classrooms. Calibrated recordings made during classroom activities in 9 schools are post processed to allow noisecharacteristics to be rated based on attributes related to the noise source or type duration rate of recurrence spectra level envelope and peak energy. Binaural and monaural recordings are compared. Speech to noise ratios are statistically weighted over various time frames and activities in an attempt to refine reproducibility among different activities. All recordings were made in occupied rooms both before and after the various treatments were integrated. The results suggest that there are misconceptions in the literature in terms of today’s classroom design trends and a few novel principles emerged as being highly effective.

Sooch SanSouci; Line Guerra; Dick Campbell

2010-01-01T23:59:59.000Z

254

MEASURING NOISE CORRELATION FOR IMPROVED VIDEO DENOISING Anil Kokaram  

E-Print Network (OSTI)

, white, noise sources. In practice this is almost always violated by real media. Film grain noise in archived video content, be it consumer digital camera or film orginated. As an example of how window side effect naturally led to the design of spatio-temporal noise reduction filters intro- duced

Tomkins, Andrew

255

Diesel knock noise from combustion phenomenon to perceived signals  

E-Print Network (OSTI)

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-acoustic properties, throught its noticeable combustion noise (also called "Diesel knock"). Combustion noise generated

Paris-Sud XI, Université de

256

Separating Signal from Noise in Global Warming Bert W. Rust  

E-Print Network (OSTI)

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

Rust, Bert W.

257

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 3.6MW turbine 12 3.2 Noise as function of wind speed 12 3.3 Noise as function of rotor

258

Our Data, Ourselves: Privacy via Distributed Noise Generation  

E-Print Network (OSTI)

Our Data, Ourselves: Privacy via Distributed Noise Generation Cynthia Dwork1 , Krishnaram of the noise generation is to create a distributed implemen- tation of the privacy-preserving statistical. The generation of Gaussian noise introduces a technique for distributing shares of many unbiased coins with fewer

Chang, Edward Y.

259

Empirical Bayes approach to improve wavelet thresholding for image noise  

E-Print Network (OSTI)

Empirical Bayes approach to improve wavelet thresholding for image noise reduction Maarten Jansen thresholding for image noise reduction Maarten Jansen Adhemar Bultheel Report TW 296, October 1999 Department to improve wavelet thresholding for image noise reduction Maarten Jansen and Adhemar Bultheel Department

Jansen, Maarten

260

Parallel Imaging and Acceleration in the Johnson Noise Dominated Regime  

E-Print Network (OSTI)

Parallel Imaging and Acceleration in the Johnson Noise Dominated Regime Cristen D. LaPierre1 receive coil in the parallel array. At low field, uncorrelated Johnson noise dominates, providing in the Johnson noise dominated regime. With the eight channel array, SENSE acceleration can be implemented

Rosen, Matthew S

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Titel des Moduls : Geruschbekmpfung/ Noise and Vibration Control  

E-Print Network (OSTI)

Titel des Moduls : Geräuschbekämpfung/ Noise and Vibration Control LP (nach ECTS): 6 Interne Kurzbe) Pflicht(P) / Wahl(W) Wahlpflicht(WP) Semester (WiSe/SoSe) Noise & Vibration Control VL 2 3 WP Wi. Springer-Verlag Berlin. ISBN 3-540-54473-9. 2. L.L. Beranek (ed.), 1971. Noise and Vibration Control. Mc

Berlin,Technische Universität

262

Comparison of predicted and measured noise levels for refinery units  

Science Journals Connector (OSTI)

Predicting noise levels from new refinery units is a vital part of environmental assessment and designing units to meet noise limits. The accuracy of those noise predictions is a very important concern. The simplest way to assess the accuracy of predictions is to compare predicted and measured noise levels. This is usually difficult because measured levels are strongly affected by noise from adjacent units and by atmospheric effects on sound propagation. Further actual noise levels of significant sources often deviate from expected levels used in the noise prediction model. Thus to meaningfully compare predicted and measured levels the actual noise source levels for the major sources atmospheric conditions and noise levels from adjacent units must all be accounted for. Predicted and measured levels are compared for two large refinery units. Measurements were made at locations where noise from adjacent units has little effect and close enough so that atmospheric conditions have little impact on the measured levels. Measured operational noise levels of major sources were used to update the noise prediction model. Accuracy of the predictions is evaluated.

Frank H. Brittain; Mark M. Gmerek

1998-01-01T23:59:59.000Z

263

Extremal shot noises, heavy tails and maxstable random fields.  

E-Print Network (OSTI)

Extremal shot noises, heavy tails and max­stable random fields. Clément Dombry # May 31, 2010 Abstract We consider the extremal shot noise defined by M(y) = sup{mh(y - x); (x, m) # #}, where function. Extremal shot noises naturally appear in extreme value theory as a model for spatial extremes

Recanati, Catherine

264

Suppressing qubit dephasing using real-time Hamiltonian estimation  

E-Print Network (OSTI)

Unwanted interaction between a quantum system and its fluctuating environment leads to decoherence and is the primary obstacle to establishing a scalable quantum information processing architecture. Strategies such as environmental and materials engineering, quantum error correction and dynamical decoupling can mitigate decoherence, but generally increase experimental complexity. Here we improve coherence in a qubit using real-time Hamiltonian parameter estimation. Using a rapidly converging Bayesian approach, we precisely measure the splitting in a singlet-triplet spin qubit faster than the surrounding nuclear bath fluctuates. We continuously adjust qubit control parameters based on this information, thereby improving the inhomogenously broadened coherence time ($T_{2}^{*}$) from tens of nanoseconds to above 2 $\\mu$s and demonstrating the effectiveness of Hamiltonian estimation in reducing the effects of correlated noise in quantum systems. Because the technique demonstrated here is compatible with arbitrary qubit operations, it is a natural complement to quantum error correction and can be used to improve the performance of a wide variety of qubits in both metrological and quantum-information-processing applications.

Michael D. Shulman; Shannon P. Harvey; John M. Nichol; Stephen D. Bartlett; Andrew C. Doherty; Vladimir Umansky; Amir Yacoby

2014-05-02T23:59:59.000Z

265

Subcritical Noise Measurements with a Nickel-Reflected Plutonium Sphere  

SciTech Connect

Subcritical measurements were conducted with an a-phase plutonium sphere reflected by nickel hemishells using the 252Cf Source-Driven Noise Analysis (CSDNA) method to provide criticality safety benchmark data. Measured configurations included a bare plutonium sphere as well as the plutonium sphere reflected by the following nickel thicknesses: 1.27, 2.54, 3.81, 5.08, and 7.62 cm. A certain ratio of spectral quantities was measured for each configuration which varies linearly with the keff of the system. In addition, two types of Monte Carlo calculations were employed: a modified version of MCNP to calculate the ratio of spectral quantities and a KCODE calculation. From the measured and computed quantities the multiplication of each configuration can be approximated. A comprehensive uncertainty analysis was then performed that includes uncertainties in the geometry and materials present in the system in addition to the uncertainties in the method and nuclear data.

Jesson D. Hutchinson; John D. Bess

2009-11-01T23:59:59.000Z

266

JOHNSON NOISE THERMOMETRY FOR DRIFT-FREE MEASUREMENTS  

SciTech Connect

In order for Johnson Noise Thermometry (JNT) to be beneficial to SMR designers, it must offer advantages beyond the current state-of-the-art technology. Comparisons to traditional RTDs and thermocouples will involve life-cycle costs, installation footprint, reliability, and accuracy. With JNT, there is additional equipment beyond what is required for the traditional RTD measurement. Therefore, the JNT-RTD system will involve additional complexity and this additional complexity must be justified. Operators will want to know that the measurement is reliable and trustworthy. It is also important that the sensor involve little, if any, additional ongoing maintenance work and that it has a low probability of causing any malfunction of the primary measurement channel. If these features can be successfully demonstrated, the JNT-RTD system could potentially save money and increase plant reliability.

Britton Jr, Charles L [ORNL; Ezell, N Dianne Bull [ORNL; Roberts, Michael [ORNL; Holcomb, David Eugene [ORNL; Wood, Richard Thomas [ORNL

2014-01-01T23:59:59.000Z

267

A Low Noise Thermometer Readout for Ruthenium Oxide Resistors  

E-Print Network (OSTI)

The thermometer and thermal control system, for the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) experiment, is described, including the design, testing, and results from the first flight of ARCADE. The noise is equivalent to about 1 Omega or 0.15 mK in a second for the RuO_2 resistive thermometers at 2.7 K. The average power dissipation in each thermometer is 1 nW. The control system can take full advantage of the thermometers to maintain stable temperatures. Systematic effects are still under investigation, but the measured precision and accuracy are sufficient to allow measurement of the cosmic background spectrum. Journal-ref: Review of Scientific Instruments Vol 73 #10 (Oct 2002)

D. J. Fixsen; P. G. A. Mirel; A. Kogut; M. Seiffert

2002-08-30T23:59:59.000Z

268

Electronic Noise Calibrator for the Small Radio Telescope RODOLFO MONTEZ JR.  

E-Print Network (OSTI)

reveal a #12;stable region from 5­10mA. The operating current should lie within this region. Our power an ambient- temperature vane calibrator to obtain a measure of the system noise, background sky, atmosphere Procedures and Projects chapter of The ARRL Handbook for Radio Amateurs for calibrating ham radios. The two

Seager, Sara

269

Tonal Noise Excited by Plasma in Cylinder Wakes Using Closed-loop Control  

E-Print Network (OSTI)

atmosphere uniform glow discharge surface plasma," IEEE International Conference on Plasma Science, IEEETonal Noise Excited by Plasma in Cylinder Wakes Using Closed-loop Control Wenjun Yu , and Xun Huang controlled by a closed-loop plasma control system was demonstrated in this work. The flow around a cylinder

Huang, Xun

270

RECOGNITION OF VOICE COMMANDS BY MULTISOURCE ASR AND NOISE CANCELLATION IN A SMART HOME ENVIRONMENT  

E-Print Network (OSTI)

In this paper, we present a multisource ASR system to detect home automation orders in various everyday colloquial or distress sentences as well as home automation orders. Techniques act- ing at the decoding stage to be made when music is used as background noise. Index Terms-- Home automation, smart home, distant speech

Boyer, Edmond

271

Communication in the Presence of Noise CLAUDE E. SHANNON, MEMBER, IRE  

E-Print Network (OSTI)

of transmission of binary digits over a system when the signal is perturbed by various types of noise. Some: This operates on the message in some way and produces a signal suitable for transmission to the receiving point of wires, a coaxial cable, a band of radio frequencies, etc. During transmission, or at the receiving

Gummadi, Ramakrishna

272

Quantum-noise quenching in quantum tweezers  

E-Print Network (OSTI)

The efficiency of extracting single atoms or molecules from an ultracold bosonic reservoir is theoretically investigated for a protocol based on lasers, coupling the hyperfine state in which the atoms form a condensate to another stable state, in which the atom experiences a tight potential in the regime of collisional blockade, the quantum tweezers. The transfer efficiency into the single-atom ground state of the tight trap is fundamentally limited by the collective modes of the condensate, which are thermally and dynamically excited and constitute the ultimate noise sources. This quantum noise can be quenched for sufficiently long laser pulses, thereby achieving high efficiencies, and showing that this protocol can be applied for quantum information processing based on tweezer traps for neutral atoms.

Zippilli, Stefano; Lutz, Eric; Morigi, Giovanna; Schleich, Wolfgang

2010-01-01T23:59:59.000Z

273

Influence of refraction on wind turbine noise  

E-Print Network (OSTI)

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.

Makarewicz, Rufin

2013-01-01T23:59:59.000Z

274

Levels and Spectra of Transportation Vehicle Noise  

Science Journals Connector (OSTI)

In the years immediately preceding the war an informal program of the study of traffic transportationvehicle and industrial noise was undertaken in the Chicago area. In the recent past another but much more exhaustive program has been initiated and further and more detailed work has now been done. One phase of the work has been a study of the noise within the various types of vehicles generally employed in transportation. These include older and newer type trolley cars and trolley buses elevated lines and subway cars suburban electric and steam trains and passenger automobiles.Measurements were made in these vehicles not only of total sound level but of components in octave bands in the audible frequency range. The work has therefore permitted a comparison of the acoustic spectra in these vehicles and curves to show these characteristic differences will be shown.

G. L. Bonvallet

1949-01-01T23:59:59.000Z

275

Nonequilibrium noise in electrophoresis: the microion wind  

E-Print Network (OSTI)

We analyze theoretically the dynamics of a single colloidal particle in an externally applied electric field. The thermal motions of microions lead to an anisotropic, nonequilibrium source of noise, pro- portional to the field, in the effective Langevin equation for the colloid. The fluctuation-dissipation ratio depends strongly on frequency, and the colloid if displaced from its steady-state position relaxes with a velocity not proportional to the gradient of the logarithm of the steady-state probability.

Suropriya Saha; Sriram Ramaswamy

2009-07-02T23:59:59.000Z

276

Neutron noise measurements at the Delphi subcritical assembly  

SciTech Connect

The paper presents the results and evaluations of a comprehensive set of neutron noise measurements on the Delphi subcritical assembly of the Delft Univ. of Technology. The measurements investigated the effect of different source distributions (inherent spontaneous fission and {sup 252}Cf) and the position of the detectors applied (both radially and vertically). The evaluation of the measured data has been performed by the variance-to-mean ratio (VTMR, Feynman-{alpha}), the autocorrelation (ACF, Rossi-{alpha}) and the cross-correlation (CCF) methods. The values obtained for the prompt decay constant show a strong bias, which depends both on the detector position and on the source distribution. This is due to the presence of higher modes in the system. It has been observed that the {alpha} value fitted is higher when the detector is close to the boundary of the core or to the {sup 252}Cf point-source. The higher alpha-modes have also been observed by fitting functions describing two alpha-modes. The successful set of measurement also provides a good basis for further theoretical investigations including the Monte Carlo simulation of the noise measurements and the calculation of the alpha-modes in the Delphi subcritical assembly. (authors)

Szieberth, M.; Klujber, G. [Inst. of Nuclear Techniques, Budapest Univ. of Technology and Economics BME, Muegyetem rkp. 3-9, H-1111 Budapest (Hungary); Kloosterman, J. L.; De Haas, D. [Section Physics of Nuclear Reactors, Delft Univ. of Technology TUD, Mekelweg 15, 2629 JB Delft (Netherlands)

2012-07-01T23:59:59.000Z

277

A neutron noise-based experiment in a TRIGA reactor  

Science Journals Connector (OSTI)

A neutron noise-based experiment performed in the TRIGA reactor of the ENEA-Casaccia centre in Italy is presented. This experiment is part of the first phase of the international TRADE programme that seeks a global demonstration of an accelerator-driven system at power. The main objective of that first experimental phase is the measurement at zero-power of fundamental neutronic parameters. The present experiment performed in the reference critical core configuration has first of all aimed at the inference of the prompt neutron decay constant at critical, which is equal to the ratio of the delayed neutron fraction to the neutron generation time. The neutron-noise technique that has been applied is the power spectral density technique, based on the use of fission chambers operated in fluctuation mode. Two fission chambers, each with a sensitivity of 10-1 cps/nv, have been placed within the core region close to the reflector. The prompt neutron decay constant at delayed critical has been estimated at 132 ± 2 s-1 with 68% confidence level.

Christian Jammes; Benoit Geslot; Philippe Fougeras; Roberto Rosa; George R. Imel

2006-01-01T23:59:59.000Z

278

A compact, multichannel, and low noise arbitrary waveform generator  

SciTech Connect

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.

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

279

Long?term variations of ice breaking noise in Antarctica  

Science Journals Connector (OSTI)

Numerous low frequency transient signals arriving from Antarctica have been detected in five?year sea noise recordings in 2002?2006 at the hydroacoustic listening station deployed off Cape Leeuwin in Western Australia as part of the International Monitoring System of the Comprehensive Nuclear?Test?Ban Treaty. The majority of these signals consist of a single arrival of mode 1 which dominates the higher modes and undergoes strong frequency dispersion due to long?range propagation in the polar ocean environment. These signals are believed to be emitted primarily by ice rifting and breaking events on the Antarctic shelf. Several regions along the Antarctic coast associated with certain glaciers and ice tongues were found to persistently be much more active in generatingicenoise than other parts of the Antarctic shelf. An analysis of long?term changes in the frequency of occurrence of ice events showed noticeable seasonal cycles but did not reveal any significant interannual variations against the background of short?term fluctuations. Some of the ice events detected at the Cape Leeuwin station were also identified in sea noise recordings made on autonomous acoustic loggers deployed on the Antarctic shelf which allowed us to investigate characteristics of the acoustic signals from ice events near their origins.

Alexander Gavrilov; Binghui Li

2008-01-01T23:59:59.000Z

280

German information technology?equipment noise categorization concept: Study on several data projectors.  

Science Journals Connector (OSTI)

An investigation project tendered by the German Federal Institute for Occupational Safety and Health (BAuA) with a planned duration of 1 1/2 years has recently been awarded to Mueller?BBM. The existing concept of the quality classification of household appliances where the energy efficiency categories A–F each represents a determined range of power consumption is to be transferred to a system for the categorization of IT?equipment with regard to its noise emission. Currently it is almost impossible for a layperson to compare noise declarations provided by manufacturers even though there are standardized and very detailed specifications in ISO 9296 for the measurement and declaration of the noise emission of IT?equipment. One of the central issues of the project is the consolidation of existing procedures for noise emission measurements on IT?equipment with consideration of the impact of psychoacoustic parameters. A categorization proposal based on ISO 7779 will be presented. In order to check the neccessity of additional psychoacoustic metrics like tonality and transient loudness 11 data projectors were measured according to the BAuA proposal. In addition the annoyance of the operational noise was evaluated by a panel test. The results will be compared and contrasted with the current ISO/ECMA standard measurements.

Gregor Feneberg

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Thermo-elastic induced phase noise in the LISA Pathfinder spacecraft  

E-Print Network (OSTI)

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 ($1\\,{\\rm mHz}$).

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

282

Effects of inhomogeneous activity of players and noise on cooperation in spatial public goods games  

Science Journals Connector (OSTI)

We study the public goods game in the noisy case by considering the players with inhomogeneous activity of teaching on a square lattice. It is shown that the introduction of the inhomogeneous activity of teaching the players can remarkably promote cooperation. By investigating the effects of noise on cooperative behavior in detail, we find that the variation of cooperator density ?C with the noise parameter ? displays several different behaviors: ?C monotonically increases (decreases) with ?; ?C first increases (decreases) with ? and then it decreases (increases) monotonically after reaching its maximum (minimum) value, which depends on the amount of the multiplication factor r, on whether the system is homogeneous or inhomogeneous, and on whether the adopted updating is synchronous or asynchronous. These results imply that the noise plays an important and nontrivial role in the evolution of cooperation.

Jian-Yue Guan; Zhi-Xi Wu; Ying-Hai Wang

2007-11-02T23:59:59.000Z

283

Impacts of Vessel Noise Perturbations on the Resident Sperm Whale Population in the Gulf of Mexico  

E-Print Network (OSTI)

RESPONSE TO NOISE ........... 92 VII FRAMEWORK FOR THE MANAGEMENT OF MARINE NOISE POLLUTION ....................................................................................... 101 Regional Framework for Noise... Pollution Management ................ 102 Nation-State Provisions .................................................................. 106 International Framework for Noise Pollution Management .......... 112 Proposed Guidelines...

Azzara, Alyson

2012-07-16T23:59:59.000Z

284

A Brief Review of Known Effects of Noise on Marine Mammals  

E-Print Network (OSTI)

of noise from an oil drilling platform. Zoo Biology, 9, 393-after playbacks of oil drilling platform noise to captive

Weilgart, Linda S.

2007-01-01T23:59:59.000Z

285

'Catch and Suppress' Control of Instabilities in High Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

'Catch and Suppress' Control of Instabilities in High Performance 'Catch and Suppress' Control of Instabilities in High Performance Fusion Plasmas Fusion Energy Sciences (FES) FES Home About Research Facilities Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) News & Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4941 F: (301) 903-8584 E: sc.fes@science.doe.gov More Information » October 2012 'Catch and Suppress' Control of Instabilities in High Performance Fusion Plasmas Real time steering of microwave beams is used to suppress deleterious modes on DIII-D. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo Image courtesy of General Atomics

286

Nuclear Suppression of Dileptons at Large xF  

E-Print Network (OSTI)

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.

J. Cepila; J. Nemchik

2009-09-23T23:59:59.000Z

287

J/Psi suppression in ultrarelativistic nuclear collisions  

E-Print Network (OSTI)

Using a multiphase transport model, we study the relative importance of J/psi suppression mechanisms due to plasma screening, gluon scattering, and hadron absorption in heavy ion collisions at the Relativistic Heavy Ion Collider. We find...

Zhang, B.; Ko, Che Ming; Li, Ba; Lin, ZW; Sa, BW.

2000-01-01T23:59:59.000Z

288

Diffusion suppression in gel dosimetry by addition of nanoclay  

Science Journals Connector (OSTI)

This paper reports diffusion suppression in gel dosimetery by using nanocomposite gel. A Fricke xylenol gel (FXG) and a dichromate gel (DCG) were selected for adding a small amount of nanoclay (Laponite XLG). The...

T. Maeyama; N. Fukunishi; K. L. Ishikawa…

2013-01-01T23:59:59.000Z

289

Extrahepatic Cancer Suppresses Nuclear Receptor–Regulated Drug Metabolism  

Science Journals Connector (OSTI)

...Association for Cancer Research. 15 May 2011 research-article Cancer...Cancer Suppresses Nuclear Receptor-Regulated...impaired hepatic nuclear receptor action...Health and Medical Research Council of Australia...Agency Superfund Program Grant P42 ES10337...

Marina Kacevska; Michael R. Downes; Rohini Sharma; Ronald M. Evans; Stephen J. Clarke; Christopher Liddle; and Graham R. Robertson

2011-05-15T23:59:59.000Z

290

COMMUNICATION Escherichia coli tatC Mutations that Suppress Defective  

E-Print Network (OSTI)

COMMUNICATION Escherichia coli tatC Mutations that Suppress Defective Twin-Arginine Transporter@che.utexas.edu. Abbreviations used: Tat, twin-arginine translocation; MBP, maltose-binding protein; GFP, green fluorescence

Georgiou, George

291

Suppression of ring artefacts when tomographing anisotropically attenuating samples  

Science Journals Connector (OSTI)

An intensity normalization technique is proposed to suppress ring artefacts of varying strength. The method was applied to an elongated sample in a monochromatic beam and to a sample with highly attenuated parts in a white beam.

Titarenko, S.

2011-04-02T23:59:59.000Z

292

ELECTRON SUPPRESSION IN A MULTI-CUSP NEGATIVE ION SOURCE  

E-Print Network (OSTI)

very low energy electrons at the source exit (Fig. 2). TheTo suppress the electrons at the source exit in this multi-energy primary electrons into the source plasma. The energy

Ehlers, K.W.

2013-01-01T23:59:59.000Z

293

Immune activation suppresses plasma testosterone level: a meta-analysis  

Science Journals Connector (OSTI)

...sizes of immune challenge on plasma T levels. (Immune challenges...M Sexual selection. In Princeton University Press 1994Princeton, NJ:Princeton University Press Barthelemy...Immune activation suppresses plasma testosterone level: a meta-analysis...

2008-01-01T23:59:59.000Z

294

Suppression of the vibrations of wind turbine towers  

Science Journals Connector (OSTI)

......suppression of the vibrations of wind turbine towers. As a source of renewable and clean energy, wind power is rapidly increasing its...capacity in many countries. Large offshore turbines are subjected to severe weather......

Xiaowei Zhao; George Weiss

2011-09-01T23:59:59.000Z

295

Indirect suppression of photosynthesis on individual leaves by arthropod herbivory  

E-Print Network (OSTI)

REVIEW Indirect suppression of photosynthesis on individual leaves by arthropod herbivory Paul D imaging tech- nologies revealed that alterations to photosynthesis and transpiration propagate of herbivory on photosynthesis, measured by gas exchange or chlorophyll fluorescence, and identifies four

DeLucia, Evan H.

296

Indirect Suppression of Photosynthesis on Individual Leaves by Arthropod Herbivory  

E-Print Network (OSTI)

REVIEW Indirect Suppression of Photosynthesis on Individual Leaves by Arthropod Herbivory PAUL D tissues are unaltered, and plant photosynthesis and water balance function normally. However, recent application of thermal and fluorescent imaging technologies revealed that alterations to photosynthesis

DeLucia, Evan H.

297

Observation of the Fundamental Nyquist Noise Limit in an Ultra-High $Q$-Factor Cryogenic Bulk Acoustic Wave Cavity  

E-Print Network (OSTI)

Thermal Nyquist noise fluctuations of high-$Q$ Bulk Acoustic Wave (BAW) cavities have been observed at cryogenic temperatures with a DC Superconducting Quantum Interference Device (SQUID) amplifier. High $Q$ modes with bandwidths of few tens of milliHz produce thermal fluctuations with a Signal-To-Noise ratio of up to 23dB. The estimated effective temperature from the Nyquist noise is in good agreement with the physical temperature of the device, confirming the validity of the equivalent circuit model and the non-existence of any excess resonator self-noise. The measurements also confirm that the quality factor remains extremely high ($Q>10^8$ at low order overtones) for very weak (thermal) system motion at low temperatures, when compared to values measured with relatively strong external excitation. This result represents an enabling step towards operating such a high-Q acoustic device at the standard quantum limit.

Goryachev, Maxim; van Kann, Frank; Galliou, Serge; Tobar, Michael E

2014-01-01T23:59:59.000Z

298

Observation of the Fundamental Nyquist Noise Limit in an Ultra-High $Q$-Factor Cryogenic Bulk Acoustic Wave Cavity  

E-Print Network (OSTI)

Thermal Nyquist noise fluctuations of high-$Q$ Bulk Acoustic Wave (BAW) cavities have been observed at cryogenic temperatures with a DC Superconducting Quantum Interference Device (SQUID) amplifier. High $Q$ modes with bandwidths of few tens of milliHz produce thermal fluctuations with a Signal-To-Noise ratio of up to 23dB. The estimated effective temperature from the Nyquist noise is in good agreement with the physical temperature of the device, confirming the validity of the equivalent circuit model and the non-existence of any excess resonator self-noise. The measurements also confirm that the quality factor remains extremely high ($Q>10^8$ at low order overtones) for very weak (thermal) system motion at low temperatures, when compared to values measured with relatively strong external excitation. This result represents an enabling step towards operating such a high-Q acoustic device at the standard quantum limit.

Maxim Goryachev; Eugene N. Ivanov; Frank van Kann; Serge Galliou; Michael E. Tobar

2014-10-16T23:59:59.000Z

299

Noise Effects on birhythmic Josephson Junction coupled to a Resonator  

E-Print Network (OSTI)

We study the effect of noise on a Josephson junction that, coupled to a linear $RLC$ resonator, can oscillate at two frequencies. To establish the global stability of the attractors, we estimate the position of the separatrix, an essential information to establish the stability of the attractor for this multidimensional system, from the analysis of the mean first passage time. We find that the frequency locked to the resonator is most stable at low bias, and less stable at high bias, where the resonator exhibits the largest oscillations. The change in the birhythmic region is dramatic, for the effective barrier changes of an order of magnitude and the corresponding lifetime of about seven decades.

R. Yamapi; G. Filatrella

2014-06-24T23:59:59.000Z

300

Noise-assisted Thouless pump in elastically deformable molecular junctions  

E-Print Network (OSTI)

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.

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

2014-04-16T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Noise control versus shock and vibration engineering  

Science Journals Connector (OSTI)

Noise control and shock and vibration engineering have many fundamentals in common and many analogous practical constraints. Yet in many respects they tend to be opposite in methodology philosophy and past history. The present discussion is an attempt to present the point of view of the practicing engineer in either field who has some perspective on the historical origins of his art. It focuses on aspects that epitomize the practical objectives of such engineers plus any administrators lawyers etc. who may also be involved in team efforts. For noise control the aspects chosen are establishment of regulations monitoring and design or other actions intended to bring about compliance with regulations. For shock and vibration engineering they are establishment of environmental specifications to ensure reliability environmental testing in accordance with these and design or redesign to bring about compliance with test requirements and also (we hope) to bring about reliability without severe penalties in weight schedule or cost. This is not to say that these aspects in their barest sense represent all the technology or methodology that is pertinent or even that these limited aspects will be treated comprehensively. It is almost self?evident that the Acoustical Society of America should and does maintain beneficial relationship with medical psychological mechanical engineering and other societies that report their particular developing lore of fundamentals and some practical information from their particular viewpoint. The Acoustical Society is an important part of this spectrum by virtue of its interdisciplinary coverage extending through materials dynamics sound instrumentation and electronics to speech and hearing. But it is also worthwhile for the ASA by whatever means are available to sample the flavor of various disciplines as unified and value?weighted in accordance with typical practical objectives. For this reason the developing beneficial relationships with the Institute of Noise Control (INCE) and the Shock and Vibration Information Center (SVIC) will become increasingly important.

Charles T. Morrow

1974-01-01T23:59:59.000Z

302

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

SciTech Connect

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.

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

2011-09-30T23:59:59.000Z

303

Directional noise and correlation of signal and noise variability in the ASIAEX South China Sea Experiment  

Science Journals Connector (OSTI)

As part of the 2001 ASIAEX South China Sea experiment known acoustic signals and noise were recorded for 16 days with co?located horizontal and vertical receiving arrays in 120?m depth water at the edge of the continental shelf. The location was south of China and southwest of Taiwan. Vertical and horizontal directionality of both signals and noise can be estimated using the two arrays. Directionality can be linked to vertical mode bandwidth. Furthermore because of mode stripping effects it can indicate the amount of mode coupling in the vicinity of the receiver. Previously arrival time and total energy of the signals have been shown to respond to the strong nonlinear internal waves and internal tides of the area. Here we investigate the response of noiseenergy and directionality to the waves and compare with the response of signal energy and directionality. The results can be compared to the Shelfbreak PRIMER experiment in the Mid?Atlantic Bight where signal and noise parameters recorded with a VLA were correlated. Correlation of signal and noise violates assumptions used in many signal processing algorithms.

2003-01-01T23:59:59.000Z

304

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

E-Print Network (OSTI)

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

Lefsky, Michael

305

Reactor Neutrino Flux Uncertainty Suppression on Multiple Detector Experiments  

E-Print Network (OSTI)

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.

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

2015-01-02T23:59:59.000Z

306

A simplified model of decontamination by BWR steam suppression pools  

SciTech Connect

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.

Powers, D.A.

1997-05-01T23:59:59.000Z

307

Review of Subcritical Source-Driven Noise Analysis Measurements  

SciTech Connect

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.

Valentine, T.E.

1999-11-01T23:59:59.000Z

308

Beneficial role of noise in artificial neural networks  

SciTech Connect

We demonstrate enhancement of neural networks efficacy to recognize frequency encoded signals and/or to categorize spatial patterns of neural activity as a result of noise addition. For temporal information recovery, noise directly added to the receiving neurons allow instantaneous improvement of signal-to-noise ratio [Monterola and Saloma, Phys. Rev. Lett. 2002]. For spatial patterns however, recurrence is necessary to extend and homogenize the operating range of a feed-forward neural network [Monterola and Zapotocky, Phys. Rev. E 2005]. Finally, using the size of the basin of attraction of the networks learned patterns (dynamical fixed points), a procedure for estimating the optimal noise is demonstrated.

Monterola, Christopher [National Institute of Physics, University of the Philippines 1101 Diliman Quezon City (Philippines); Max-Planck Institut fuer Physik Komplexer Systeme Noethnitzerstrasse 38, 01187, Dresden (Germany); Saloma, Caesar [National Institute of Physics, University of the Philippines 1101 Diliman Quezon City (Philippines); Zapotocky, Martin [Max-Planck Institut fuer Physik Komplexer Systeme Noethnitzerstrasse 38, 01187, Dresden (Germany)

2008-06-18T23:59:59.000Z

309

Computational Modeling of Propeller Noise: NASA SR-7A propeller.  

E-Print Network (OSTI)

??The aerospace industry has been concerned with propeller noise levels for years. This interest is two-fold: government regulation and comfort in cabin. This report attempts… (more)

Moussa, Karim

2014-01-01T23:59:59.000Z

310

Very low noise cryogenic receivers and measurement electronics.  

E-Print Network (OSTI)

??The purpose of this thesis was to develop very low noise cryogenic receivers and related high accuracy measurement setups to validate the operation of the… (more)

Sjöman, Pekka

2009-01-01T23:59:59.000Z

311

Digital halftoning by means of green-noise masks  

Science Journals Connector (OSTI)

We introduce a novel technique for generating green-noise halftones—stochastic dither patterns composed of homogeneously distributed pixel clusters. Although techniques employing error...

Lau, Daniel L; Arce, Gonzalo R; Gallagher, Neal C

1999-01-01T23:59:59.000Z

312

Hawaii Guide for Filing Community Noise Variance Applications...  

Open Energy Info (EERE)

for completing Noise Variance Applications. Author State of Hawaii Department of Health Published State of Hawaii, 072013 DOI Not Provided Check for DOI availability: http:...

313

Hawaii Application for Community Noise Variance (DOH Form) |...  

Open Energy Info (EERE)

Application for Community Noise Variance Organization State of Hawaii Department of Health Published Publisher Not Provided, 072013 DOI Not Provided Check for DOI availability:...

314

Hawaii Application for Community Noise Permit (DOH Form CNP)...  

Open Energy Info (EERE)

Application for Community Noise Permit Organization State of Hawaii Department of Health Published Publisher Not Provided, 012008 DOI Not Provided Check for DOI availability:...

315

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Integration of Noise and Coda Correlation Data into Kinematic and Waveform Inversions Fracture Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical...

316

Noise and Vibration Control of Combustion Engine Vehicles.  

E-Print Network (OSTI)

??Noise and vibrations have over the last two decades been regarded as significant environmental health problems. Regulations regarding acoustic as well as vibration levels have… (more)

Winberg, Mathias

2005-01-01T23:59:59.000Z

317

Competitive Analysis of Modeling Technology Handle noise/  

E-Print Network (OSTI)

&k - - - - - - - DRM Technologies - - - - - - - EMA INC - - - - - - - FLIR Systems, INC P - - - - - - Asset

Huang, Samuel H.

318

Suppression of complete fusion in the Li6+Sm144 reaction  

Science Journals Connector (OSTI)

Complete fusion excitation function for the Li6+Sm144 reaction has been measured at near barrier energies by the activation technique. Coupled-channel calculations show an enhancement in fusion cross section at energies below the barrier compared to the one-dimensional barrier penetration model calculation, but they overpredict it in the entire energy range compared to the experimental data. Reduced fusion cross sections for the present system at energies normalized to the Coulomb barrier were also found to be systematically lower than those with strongly bound projectiles forming a similar compound nucleus. These two observations conclusively show that the complete fusion cross section, at above barrier energies, is suppressed by ~32% in the Li6+Sm144 reaction. Reanalyses of existing fusion data for Li7+Ho165 and Li7+Tb159 also show a suppression compared to those with strongly bound projectiles, which contradicts earlier conclusions. The fusion suppression factor seems to exhibit a systematic behavior with respect to the breakup threshold of the projectile and the atomic number of the target nucleus.

P. K. Rath, S. Santra, N. L. Singh, R. Tripathi, V. V. Parkar, B. K. Nayak, K. Mahata, R. Palit, Suresh Kumar, S. Mukherjee, S. Appannababu, and R. K. Choudhury

2009-05-11T23:59:59.000Z

319

Noise pair velocity and range echo location system  

DOE Patents (OSTI)

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.

Erskine, David J. (Oakland, CA)

1999-01-01T23:59:59.000Z

320

Noise pair velocity and range echo location system  

DOE Patents (OSTI)

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.

Erskine, D.J.

1999-02-16T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Fossil Biodiversity: Red Noise Plus Signal  

E-Print Network (OSTI)

We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^8 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

Adrian L. Melott; Bruce S. Lieberman

2006-06-14T23:59:59.000Z

322

Fossil Biodiversity: Red Noise Plus Signal  

E-Print Network (OSTI)

We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^5 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

Melott, A L; Melott, Adrian L.; Lieberman, Bruce S.

2006-01-01T23:59:59.000Z

323

Quantum-noise quenching in atomic tweezers  

SciTech Connect

The efficiency of extracting single atoms or molecules from an ultracold bosonic reservoir is theoretically investigated for a protocol based on lasers, coupling the hyperfine state in which the atoms form a condensate to another stable state, in which the atom experiences a tight potential in the regime of collisional blockade, the quantum tweezers. The transfer efficiency into the single-atom ground state of the tight trap is fundamentally limited by the collective modes of the condensate, which are thermally and dynamically excited. The noise due to these excitations can be quenched for sufficiently long laser pulses, thereby achieving high efficiencies. These results show that this protocol can be applied to initializing a quantum register based on tweezer traps for neutral atoms.

Zippilli, Stefano [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Theoretische Physik, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany); Fachbereich Physik and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany); Mohring, Bernd; Schleich, Wolfgang [Institut fuer Quantenphysik, Universitaet Ulm, D-89081 Ulm (Germany); Lutz, Eric [Department of Physics, University of Augsburg, D-86135 Augsburg (Germany); Morigi, Giovanna [Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Theoretische Physik, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany)

2011-05-15T23:59:59.000Z

324

Quantum-noise quenching in atomic tweezers  

E-Print Network (OSTI)

The efficiency of extracting single atoms or molecules from an ultracold bosonic reservoir is theoretically investigated for a protocol based on lasers, coupling the hyperfine state in which the atoms form a condensate to another stable state, in which the atom experiences a tight potential in the regime of collisional blockade, the quantum tweezers. The transfer efficiency into the single-atom ground state of the tight trap is fundamentally limited by the collective modes of the condensate, which are thermally and dynamically excited. The noise due to these excitations can be quenched for sufficiently long laser pulses, thereby achieving high efficiencies. These results show that this protocol can be applied for initializing a quantum register based on tweezer traps for neutral atoms.

Stefano Zippilli; Bernd Mohring; Eric Lutz; Giovanna Morigi; Wolfgang Schleich

2011-04-15T23:59:59.000Z

325

Investigation of noise sources in SQUID electronics  

SciTech Connect

The performance of SQUID-based electronics outside a laboratory-controlled environment may be degraded from that found in laboratory operation. Investigations on superconducting tubes, wires, and sheets have been conducted to identify contributions to such noise. Results have been obtained for bulk and thin film samples utilizing both the conventional low temperature materials, as well as the new high temperature oxide materials. Experiments have been conducted to quantify flux redistribution and flux motion in superconducting samples subjected to temperature changes, temperature gradients, and magnetic field gradients. These investigations have been conducted at magnetic fields typical of many SQUID applications, with field intensities much smaller than the critical values H/sub cl/. Penetration depth effects, flux pinning effects, and flux motion effects have been observed. The various types of experiments conducted along with specific results are described.

Clem, T.R.; Goldstein, M.J.; Purpura, J.W.; Allen, L.H.; Claassen, J.H.; Gubser, D.U.; Wolf, S.A.

1989-03-01T23:59:59.000Z

326

Technology Assessment of Dust Suppression Techniques Applied During Structural Demolition  

SciTech Connect

Hanford, Fernald, Savannah River, and other sites are currently reviewing technologies that can be implemented to demolish buildings in a cost-effective manner. In order to demolish a structure properly and, at the same time, minimize the amount of dust generated from a given technology, an evaluation must be conducted to choose the most appropriate dust suppression technology given site-specific conditions. Thus, the purpose of this research, which was carried out at the Hemispheric Center for Environmental Technology (HCET) at Florida International University, was to conduct an experimental study of dust aerosol abatement (dust suppression) methods as applied to nuclear D and D. This experimental study targeted the problem of dust suppression during the demolition of nuclear facilities. The resulting data were employed to assist in the development of mathematical correlations that can be applied to predict dust generation during structural demolition.

Boudreaux, J.F.; Ebadian, M.A.; Williams, P.T.; Dua, S.K.

1998-10-20T23:59:59.000Z

327

Contribution of iceberg sounds to the ambient noise budget in the South Pacific Ocean  

Science Journals Connector (OSTI)

On May 2002 C19 a 5500 km2 iceberg calved from the Ross Ice Shelf eventually drifting eastward into the open Pacific Ocean by 2008. As it sailed into warmer waters thermal and wind stresses caused the iceberg to crack and break apart. These resulting “icequakes” projected wideband acoustic energy into the water column influencing the regional ambient noise environment. Icequake noise was persistent and strong enough to be observed by NOAA’s eastern equatorial Pacific moored hydrophone (EEP-NW at 8N 110W) as well as the hydroacoustic station of International Monitoring System (IMS) on Juan Fernandez Island (H03N at 33.44S 78.91W). Elevated noise levels (maximum of ~+3 dB at NOAA’s EEP and ~+7 dB at IMS H03N hydrophones) were observed by both stations from early 2008 when C19a first appeared in the Pacific until it drifted into the Atlantic Ocean in early 2009. C19a’s icequake and calving activity was also most frequent during this same period. Seasonal changes and long-term trends in ambient noise levels at NOAA’s EEP-NW acoustic mooring (1996–2009) and IMS Juan Fernandez (2003–2010 years) and the unique acoustic role icebergs play in the Southern Ocean will be presented.

Haru Matsumoto; Robert Dziak; Minkyu Park; Won-Sang Lee; Tai-Kwan Lau; Matt Fowler

2013-01-01T23:59:59.000Z

328

Underwater, low-frequency noise in a coastal sea turtle habitat  

Science Journals Connector (OSTI)

Underwater sound was recorded in one of the major coastal foraging areas for juvenile sea turtles in the Peconic Bay Estuary system in Long Island New York. The recording season of the underwater environment coincided with the sea turtle activity season in an inshore area where there is considerable boating and recreational activity especially during the summer between Independence Day and Labor Day. Within the range of sea turtle hearing average noisepressure reached 110 dB during periods of high human activity and diminished proportionally down to 80 dB with decreasing human presence. Therefore during much of the season when sea turtles are actively foraging in New York waters their coastal habitats are flooded with underwater noise. During the period of highest human activity average noisepressures within the range of frequencies heard by sea turtles were greater by over two orders of magnitude (26 dB) than during the lowest period of human activity. Sea turtles undoubtedly are exposed to high levels of noise most of which is anthropogenic. Results suggest that continued exposure to existing high levels of pervasive anthropogenic noise in vital sea turtle habitats and any increase in noise could affect sea turtle behavior and ecology.

Y. Samuel; S. J. Morreale; C. W. Clark; C. H. Greene; M. E. Richmond

2005-01-01T23:59:59.000Z

329

An alternative model of jet suppression at RHIC energies  

E-Print Network (OSTI)

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.

Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

2003-02-10T23:59:59.000Z

330

The Theta Laser A Low Noise Chirped Pulse Laser  

E-Print Network (OSTI)

The 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 a frequency swept laser, · linear f-sweep, · uniform-intensity, · low noise, · with long-term stability

Van Stryland, Eric

331

Wind dependence of deep ocean ambient noise at low frequencies  

Science Journals Connector (OSTI)

A series of experiments has been carried out using a vertical line array to measure low?frequency ambient noise at deep ocean sites in the Northeast Pacific Ocean. Data in the band from 13 to 300 Hz were processed to obtain the array response directed vertically upward in order to study the noise due to local winds. The results indicate that there are two regimes of behavior depending on the wind speed v with the transition occurring at the onset of wave breaking v?10 kn. The noise level (NL) for a specific wind noise process was related to a power n of the wind speed according to the relationship NL=B+20n?log?v and the model parameters were obtained by fitting the data. The average value over the band was n=0.3 for wind speeds wind?generated noise was determined over the low?frequency band for wind speeds from 10–30 kn. The values are consistent with those of a recent analysis of available noise data [Kewley e t a l. ‘‘Low?frequency wind?generated ambient noise source levels ’’ J. Acoust. Soc. Am. 8 8 1894–1902 (1990)] and the model provides good agreement with wind noise measurements obtained with omni hydrophones in the southern oceans.

N. R. Chapman; J. W. Cornish

1993-01-01T23:59:59.000Z

332

Quantum error correction with degenerate codes for correlated noise  

SciTech Connect

We introduce a quantum packing bound on the minimal resources required by nondegenerate error-correction codes for any kind of noise. We prove that degenerate codes can outperform nondegenerate ones in the presence of correlated noise, by exhibiting examples where the quantum packing bound is violated.

Chiribella, Giulio [Perimeter Institute for Theoretical Physics, 31 Caroline St. North, Waterloo, Ontario N2L 2Y5 (Canada); Dall'Arno, Michele; D'Ariano, Giacomo Mauro; Macchiavello, Chiara; Perinotti, Paolo [Quit group, Dipartimento di Fisica 'A. Volta', via Bassi 6, I-27100 Pavia (Italy); INFN Sezione di Pavia, via Bassi 6, I-27100 Pavia (Italy)

2011-05-15T23:59:59.000Z

333

CHARACTERISTICS OF IMPULSIVE NOISE IN ELECTRICITY SUBSTATIONS Qingshan Shan1  

E-Print Network (OSTI)

CHARACTERISTICS OF IMPULSIVE NOISE IN ELECTRICITY SUBSTATIONS Qingshan Shan1 , Shahzad Bhatti1.shan@eee.strath.ac.uk, website: www.strath.ac.uk ABSTRACT Measurements of noise in an electricity substation are re- ported-voltage electricity substations, has discouraged electricity utility companies from deploying wireless technologies

Atkinson, Robert C

334

Trailing Edge Noise Model Applied to Wind Turbine Airfoils  

E-Print Network (OSTI)

flows, as well as the acoustic waves, using Computational Fluid Dynamics have become affordable thanksTrailing Edge Noise Model Applied to Wind Turbine Airfoils Franck Bertagnolio Risø-R-1633(EN) Risø Bertagnolio Title: Trailing Edge Noise Model Applied to Wind Turbine Airfoils Department: Wind Energy

335

Poisson Distributed Noise Generation for Spiking Neural Applications  

E-Print Network (OSTI)

Poisson Distributed Noise Generation for Spiking Neural Applications Katherine Cameron, Thomas neural networks. However, it can be difficult to generate large truly random spike distributions which as randomly firing and a matlab generated Poisson distributed noise source. A hazard function shows

Cameron, Katherine

336

Coherent Quantum-Noise Cancellation for Optomechanical Sensors  

E-Print Network (OSTI)

Using a flowchart representation of quantum optomechanical dynamics, we design coherent quantum-noise-cancellation schemes that can eliminate the back-action noise induced by radiation pressure at all frequencies and thus overcome the standard quantum limit of force sensing. The proposed schemes can be regarded as novel examples of coherent feedforward quantum control.

Mankei Tsang; Carlton M. Caves

2010-08-17T23:59:59.000Z

337

Noise source identification techniques: simple to advanced applications  

E-Print Network (OSTI)

required. Practical application examples ranging from hearing aids to wind turbines are presented to optimise the noise emission from a wide range of products including vehicles, household goods and windNoise source identification techniques: simple to advanced applications K.B. Ginn and K. Haddad Br

Paris-Sud XI, Université de

338

Research paper From noise to pitch: Transient and sustained responses  

E-Print Network (OSTI)

Research paper From noise to pitch: Transient and sustained responses of the auditory evoked field a novel component of the auditory evoked field, which is elicited by a tran- sition from noise to pitch in the absence of a change in energy. It is referred to as the `pitch onset response'. To extend our

Cambridge, University of

339

A Low Noise Readout Circuit for Integrated Electrochemical Biosensor Arrays  

E-Print Network (OSTI)

A Low Noise Readout Circuit for Integrated Electrochemical Biosensor Arrays Jichun Zhang, Nicholas 48823, USA {zhangjic, tromblyn, mason}@egr.msu.edu Abstract This paper presents a low noise electrochemical interface circuit that is tuned to the needs of protein-based biosensor arrays and compatible

Mason, Andrew

340

Noise and Bandwidth Performance of Single-Molecule Biosensors  

E-Print Network (OSTI)

Noise and Bandwidth Performance of Single-Molecule Biosensors J. Rosenstein, S. Sorgenfrei, K. L and nanotube field-effect transistors offer different tradeoffs between bandwidth and noise levels. Here, we on force spectroscopy, such as optical tweezers [4] and atomic force microscopy [5]. New electrochemical

Shepard, Kenneth

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Recent Advances Related to SPDEs with Fractional Noise  

E-Print Network (OSTI)

band. This analogy extends naturally to other "colors" of noise. In signal theory and audio engineering.1) Research supported by a grant from the Natural Sciences and Engineering Research Council of Canada. #12]). The noise is a very important concept in engineering and physics, where it usually refers to anything

Balan, Raluca

342

Room noise criteria standards: What features are important?  

Science Journals Connector (OSTI)

At the joint meeting of ASA and NOISE?CON 97 in June 1997 the authors organized a special session on room noise criteria in which a ‘‘questionnaire’’ on the features of several existing noise criteria methods was answered by panel experts and distributed to the noise control community for their inputs. The four methods were: the A?weighted sound?pressure level; the noise criteria (NC) tangency method contained in older versions of the ASHRAE handbook; the balanced noise criterion method (NCB) contained in ANSI S12.2; and the room criteria method (RC) contained in ANSI S12.2 and the current ASHRAE handbook. The features considered were: speech interference high?frequency annoyance mid/low frequency annoyance very low?frequency annoyance pure tones temporal fluctuations user friendliness wider frequency range speech privacy costs and ability to handle noises with abnormal characteristics and complexity. The questionnaire rating was twofold: (1) how well does each method adequately account for each of the ‘‘features’’ (or characteristics) relative to the other methods and (2) what is the relative importance of each of the ‘‘features’’ in a noise criteria method. This paper presents the results of the questionnaires and reports progress since the joint meeting in ANSI S12 WG18 and ASHRAE TC2.6.

Hsien?sheng (Jason) Pei; Robert D. Hellweg Jr.; Richard Peppin

1997-01-01T23:59:59.000Z

343

Noise Estimate of Pendular Fabry-Perot through Reflectivity Change  

E-Print Network (OSTI)

A key issue in developing pendular Fabry-Perot interferometers as very accurate displacement measurement devices, is the noise level. The Fabry-Perot pendulums are the most promising device to detect gravitational waves, and therefore the background and the internal noise should be accurately measured and reduced. In fact terminal masses generates additional internal noise mainly due to thermal fluctuations and vibrations. We propose to exploit the reflectivity change, that occurs in some special points, to monitor the pendulums free oscillations and possibly estimate the noise level. We find that in spite of long transients, it is an effective method for noise estimate. We also prove that to only retain the sequence of escapes, rather than the whole time dependent dynamics, entails the main characteristics of the phenomenon. Escape times could also be relevant for future gravitational wave detector developments.

Addesso, Paolo; Filatrella, Giovanni

2014-01-01T23:59:59.000Z

344

Costs and benefits of noise control in the petroleum industry  

Science Journals Connector (OSTI)

Noise from industrial operations has become widely recognized as a potential hazard to health. industry labor and government share a common interest in assessing the hazard and reducing it to a socially acceptable risk. Achieving these ends requires the use of information about the amounts of noise exposure encountered the relation of exposure to risk and the costs of noise control required to achieve specified benefits. Such information pertaining specifically to the petroleum industry is the subject of this paper. We report here some estimates of benefits and costs aggregated for the petroleum industry. We define the benefits as reduced incidence of hearing damage in refinery workers in relation to certain existing and proposed Federal regulations. For such category of regulation we estimate the number of refinery workers now exposed to noise that exceeds the regulated amount and we estimate the national cost of reducing the noise to the regulated amount.

Robert D. Bruce

1975-01-01T23:59:59.000Z

345

Computer Aids for the Solution of Common Noise?Control Problems  

Science Journals Connector (OSTI)

Time?shared computer systems permit the economical use of computer assistance in solving acoustic problems. Programs have been developed that provide (1) graphical outputs of measured and computed data (2) quicker and more thorough treatment of some common problems and (3) iterative solutions that assist in the noise control design process. Examples of these programs include 1 3 ? oct band plots statistical analyses room?mode frequency calculations and muffler?design calculations.

J. J. Coles, Bolt Beranek and Newman Inc., Cambridge, Massachusetts

1969-01-01T23:59:59.000Z

346

Suppression of bulk conductivity in InAs/GaSb broken gap composite quantum wells  

SciTech Connect

The two-dimensional topological insulator state in InAs/GaSb quantum wells manifests itself by topologically protected helical edge channel transport relying on an insulating bulk. This work investigates a way of suppressing bulk conductivity by using gallium source materials of different degrees of impurity concentrations. While highest-purity gallium is accompanied by clear conduction through the sample bulk, intentional impurity incorporation leads to a bulk resistance over 1 M?, independent of applied magnetic fields. In addition, ultra high electron mobilities for GaAs/AlGaAs structures fabricated in a molecular beam epitaxy system used for the growth of Sb-based samples are reported.

Charpentier, Christophe; Fält, Stefan; Reichl, Christian; Nichele, Fabrizio; Nath Pal, Atindra; Pietsch, Patrick; Ihn, Thomas; Ensslin, Klaus; Wegscheider, Werner [Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich (Switzerland)] [Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich (Switzerland)

2013-09-09T23:59:59.000Z

347

White noise approach to the low density limit of a quantum particle in a gas  

E-Print Network (OSTI)

The white noise approach to the investigation of the dynamics of a quantum particle interacting with a dilute and in general non-equilibrium gaseous environment in the low density limit is outlined. The low density limit is the kinetic Markovian regime when only pair collisions (i.e., collisions of the test particle with one particle of the gas at one time moment) contribute to the dynamics. In the white noise approach one first proves that the appropriate operators describing the gas converge in the sense of appropriate matrix elements to certain operators of quantum white noise. Then these white noise operators are used to derive quantum white noise and quantum stochastic equations describing the approximate dynamics of the total system consisting of the particle and the gas. The derivation is given ab initio, starting from the exact microscopic quantum dynamics. The limiting dynamics is described by a quantum stochastic equation driven by a quantum Poisson process. This equation then applied to the derivation of quantum Langevin equation and linear Boltzmann equation for the reduced density matrix of the test particle. The first part of the paper describes the approach which was developed by L. Accardi, I.V. Volovich and the author and uses the Fock-antiFock (or GNS) representation for the CCR algebra of the gas. The second part presents the approach to the derivation of the limiting equations directly in terms of the correlation functions, without use of the Fock-antiFock representation. This approach simplifies the derivation and allows to express the strength of the quantum number process directly in terms of the one-particle $S$-matrix.

Alexander Pechen

2006-07-19T23:59:59.000Z

348

Stable plateau formation and Brillouin suppression in laser plasma  

SciTech Connect

Among the variety of ponderomotively induced density structures in laser produced plasmas in one dimension, it is shown by particle-in-cell simulations that the stable plateau formation at critical, subcritical, and above critical density is possible. Stimulated Brillouin backscattering is suppressed with increasing laser intensity.

Mulser, P. [Theoretical Quantum Electronics (TQE), Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Weng, S. M. [Theoretical Quantum Electronics (TQE), Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Department of Physics, Ludwig-Maximilians-Universitaet Muenchen, D-80333 Munich (Germany)

2010-10-15T23:59:59.000Z

349

Apparatus and method for suppressing diffraction rings in a laser  

SciTech Connect

This patent describes a method of manufacturing a gas laser having an envelope for containing a laser gas and a tube in the envelope which surrounds an optical path. The method comprising flowing a substance through the tube to roughen interior surfaces of the tube such that diffraction rings in light output from the laser are suppressed.

Cook, B.H. Jr.

1989-10-10T23:59:59.000Z

350

Surface-wave-enabled darkfield aperture for background suppression during  

E-Print Network (OSTI)

can be directly incorporated onto optical sensors to accom- plish predetection background suppression if the sensor is fully capable of measuring the same weak signal in the absence of background (1, 2- trivial to employ. A sensor that can intrinsically cancel a strong background prior to signal detection

Yang, Changhuei

351

Fission-suppressed hybrid reactor: the fusion breeder  

SciTech Connect

Results of a conceptual design study of a /sup 233/U-producing fusion breeder are presented. The majority of the study was devoted to conceptual design and evaluation of a fission-suppressed blanket and to fuel cycle issues such as fuel reprocessing, fuel handling, and fuel management. Studies in the areas of fusion engineering, reactor safety, and economics were also performed.

Moir, R.W.; Lee, J.D.; Coops, M.S.

1982-12-01T23:59:59.000Z

352

Intrinsically Disordered Proteins and Conformational Noise: Implications in Gita Mahmoudabadi1  

E-Print Network (OSTI)

1 Intrinsically Disordered Proteins and Conformational Noise: Implications New York, NY 10027 Key words: Intrinsically disordered proteins, noise: Conformational noise and state-switching #12;2 Abstract Intrinsically disordered proteins

Rangarajan, Govindan

353

Fast noise in the Landau-Zener theory RID B-5617-2009  

E-Print Network (OSTI)

We study the influence of a fast noise on Landau-Zener transitions. We demonstrate that a fast colored noise much weaker than the conventional white noise can produce transitions itself or can change substantially the Landau-Zener transition...

Pokrovsky, Valery L.; Sinitsyn, NA.

2003-01-01T23:59:59.000Z

354

E-Print Network 3.0 - absolute johnson noise Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

johnson noise Search Powered by Explorit Topic List Advanced Search Sample search results for: absolute johnson noise Page: << < 1 2 3 4 5 > >> 1 JOHNSON NOISE THERMOMETRY USING A...

355

Low Dose Suppression of Neoplastic Transformation in Vitro  

SciTech Connect

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.

John Leslie Redpath

2012-05-01T23:59:59.000Z

356

Mechanical Efficiency and Noise Reduction of Segmented Stator Vanes  

Science Journals Connector (OSTI)

Model experiments indicating the possibility of several decibels of noise reduction with small change of mechanical efficiency in axial flow compressors using segmented stator vanes have been reported [J. Acoust. Soc. Amer. 47 111 (A) (1970)]. Compared with straight?edged vanes the serrated vanes provide 2–5 dB of noise reduction and no change in efficiency at the design conditions. Changing relative numbers of rotor blades and stator vanes gives either improved efficiency and no noise reduction or reduced efficiency and greater noise reduction. Off?design flow angles present a complicated pattern of results but in general the serrated vanes compared with straight?edged vanes are equally efficient and have increased broad?band noise but less blade?passage?frequency noise. As a noise reduction mechanism for turbine engines it may be used with most other techniques and the effects are likely to be additive; however its maximum benefit is likely to be about 5 dB.

T. F. W. Embleton; G. J. Thiessen

1971-01-01T23:59:59.000Z

357

Corpuscular theory of intensity noise with gain compression  

Science Journals Connector (OSTI)

When light from a laser is fully absorbed by an ideal detector, the detected current exhibits a fluctuation called here ‘‘photonic noise.’’ The spectral density of Iintensity noiseR, defined as the difference of the photonic-noise spectral density and a term corresponding to the shot-noise level, is negative for sub-Poissonian statistics. The usefulness of the relative-intensity-noise concept is that it is independent of any linear attenuation. A simple circuit theory of intensity noise based only on energy conservation and the Nyquist formula (zero-point fluctuation) leads to expressions of the spectral densities that agree with quantum theory even for sub-Poissonian photon statistics. When the optical gain and loss are frequency independent, the circuit theory reduces to a corpuscular theory that keeps track of the time rates of change of electron and photon numbers treated as continuous variables. Consideration is given to laser diodes in which the rate of electron-photon conversion depends nonlinearly on both the carrier and photon densities. The cross-spectral density between electrical-voltage and relative photonic fluctuations is independent of internal or external optical losses. Standard rate equations are inaccurate in the case of gain compression. Very general yet simple formulas for intensity noise are applied to room-temperature GaAs laser diodes, using recently calculated optical parameters.

J. Arnaud

1992-02-01T23:59:59.000Z

358

Apparatus and method for suppressing vibration and displacement of a bellows  

DOE Patents (OSTI)

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 (FIG. 3B) to separate them from each other, or to maintain the bellows in unsupported relationship between these systems (FIG. 4B). 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 (FIG. 4B), 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 (20) in surrounding relationship about a bellows (14) to suppress vibration and displacement thereof. A method for isolating first and second systems (11,12) from each other to prevent the transmission of vibratory energy therebetween comprises the steps of attaching at least one flexible bellows (14) between the systems (11,12), surrounding the bellows with an inflatable tube (20), and maintaining a predetermined pressure in the tube (20) to urge the tube in flexible contact with at least some of the convolutions of the bellows (14).

Kuklo, Thomas C. (Ripon, CA)

1985-01-01T23:59:59.000Z

359

Frequency and amplitude shifts in the whistle vocalizations of bottlenose dolphins in response to anthropogenic noise  

E-Print Network (OSTI)

and amplitude; and (b) "quiet", "interval" and "one-third octave" background noise. FIG. 7. Kruskal-Wallis results for (a) "one-third octave" background noise, and (b) "interval" background noise in quiet and noisy categories. . FIG. 8, Bar graph of (a...) "interval" background noise, (b) "one-third octave" background noise, and (c) "quiet" background noise, in quiet and noisy categories. . . . . . . . . . . . . . . ?. .. 50 FIG. 9. Kruskal-Wallis results for (a) whistle mean frequency, (b) peak frequency...

Candelaria-Ley, Roxanne Inez

2012-06-07T23:59:59.000Z

360

Breaking wind waves as a source of ambient noise  

Science Journals Connector (OSTI)

A theoretical model for the prediction of ambient noise level due to collective oscillations of air bubbles under breaking wind waves is presented. The model uses a budget of the energy flux from the breaking waves to quantify acoustic power radiation by a bubble cloud. A shift of the noise spectra to lower frequency due to collective bubble oscillation is assumed. The model derives good estimates of the magnitude slope and frequency range of the noise spectra using the wind speed or height of breaking waves.

Pavlo Tkalich; Eng Soon Chan

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Generating long streams of $1/f^alpha$ noise  

E-Print Network (OSTI)

We review existing methods for generating long streams of 1/f^alpha noise ($0generator (white outside some bounds) in order to generate very long streams of noise without an exhaustive computer memory load. For $\\alpha=2$ it is shown why the process is equivalent to a random-walk and can be obtained simply by a first order filtering of white noise. As soon as $\\alphagenerators with $\\alpha>2$. The software is available from http://planck.lal.in2p3.fr/article.php3?id\\_article=8

S. Plaszczynski

2005-10-04T23:59:59.000Z

362

High-frequency intensity noise of lead-salt diode lasers  

Science Journals Connector (OSTI)

The high-frequency intensity noise spectra of mid-infrared diode lasers have been investigated. Theoretical estimates are compared with experimental results of spectral noise...

Fischer, H; Tacke, M

1991-01-01T23:59:59.000Z

363

Numerical Investigation of Flow Induced Noise in a Simplified HVAC Duct with OpenFOAM.  

E-Print Network (OSTI)

?? Due to the growing demand for comfort, the noise generated by HVAC components should be considered by the designers. Flow induced noise is one… (more)

Wang, Cong

2013-01-01T23:59:59.000Z

364

Noise impact of single-event upsets on an FPGA-based digital filter  

SciTech Connect

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.

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

365

A systematic method to identify nonlinear dynamics of BWR by using the reactor noise  

Science Journals Connector (OSTI)

For the identification of the dynamics of the Vermont Yankee BWR with the reactor noise, different parametric models have been tested. The widely used ARMA model is unable to identify the nonlinearity in the noise data. A systematic method by using the NARMA model, which takes advantage of both the ANN and ARMA, is developed. Comparisons are made between the identification results with ARMA and NARMA model. The advantages of identification with NARMA model over ARMA model are demonstrated. The linear-kernels of the identified NARMA models are extracted so that the natural frequency, damping ratio and time constants of the BWR are obtained. The values of those characteristics are well corresponded with the eigenvalues calculated by the differential equations of the Vermont Yankee BWR. The damping ratio with negative value is found to be a criterion for the existence of limit-cycle, which can be seen from the impulse response on the (Xt, Xt?1) plane, in stable nonlinear system.

Liu Wenfeng; Luo Zhengpei; Li Fu; Wang Yaqi

2003-01-01T23:59:59.000Z

366

Noise and microresonance of critical current in Josephson junction induced by Kondo trap states  

E-Print Network (OSTI)

We analyze the impact of trap states in the oxide layer of a superconducting tunnel junctions, on the fluctuation of the Josephson critical current, thus on coherence in superconducting qubits. Two mechanisms are usually considered: the current blockage due to repulsion at the occupied trap states, and the noise from electrons hopping across a trap. We extend previous studies of noninteracting traps to the case where the traps have on-site electron repulsion inside one ballistic channel. The repulsion not only allows the appropriate temperature dependence of 1/f noise, but also is a control to the coupling between the computational qubit and the spurious two-level systems inside the oxide dielectric. We use second order perturbation theory which allows to obtain analytical formulae for the interacting bound states and spectral weights, limited to small and intermediate repulsions. Remarkably, it still reproduces the main features of the model as identified from the Numerical Renormalization Group. We present ...

Ansari, Mohammad H

2011-01-01T23:59:59.000Z

367

On the use of noise budgets to assess the effects of offshore wind farms on marine life.  

Science Journals Connector (OSTI)

An oceannoise budget is a list of sources of noise along with their average intensity in a particular frequency band [Frisk et al. (2003)]. The budget can be calculated from acoustic data collected by the passive aquatic listener (PAL) systems [Nystuen and Howe (2005); Miller et al. (2008)]. In the far field the average acoustic intensity of plane waves can be computed in 1/3?octave bands over some duration. The assumption is made that the noise in the band at any one time is dominated by a single identifiable source such as wind rain shipping fish marine mammals etc. The duration and instantaneous intensity of the acoustic signal is used to calculate the average. Identification is carried out using the ratios of various spectral levels as outlined in the work of Ma et al. [(2005)]. We apply the concept of noise budgets to the assessment of the impact of long term noise from offshore wind turbines on marine life. A developer has proposed to construct more than 200 wind turbines south of Rhode Island. A noise budget has been calculated for the region from data collected on PALs. The addition of the 200 turbines will be incorporated into the budget parametrized on source level.

James H. Miller; Gopu R. Potty; David S. Casagrande; Kathleen J. Vigness Raposa; Lisa A. Miller; Jeffrey A. Nystuen; Peter M. Scheifele; John Greer Clark

2011-01-01T23:59:59.000Z

368

Application of Noise Cancelling and Damage Detection Algorithms in NDE of Concrete Bridge Decks Using Impact Signals  

SciTech Connect

Delamination is a commonly observed distress in concrete bridge decks. Among all the delamination detection methods, acoustic methods have the advantages of being fast and inexpensive. In traditional acoustic inspection methods, the inspector drags a chain along or hammers on the bridge deck and detects delamination from the 'hollowness' of the sounds. The signals are often contaminated by ambient traffic noise and the detection of delamination is highly subjective. This paper describes the performance of an impact-bases acoustic NDE method where the traffic noise was filtered by employing a noise cancelling algorithm and where subjectivity was eliminated by introducing feature extraction and pattern recognition algorithms. Different algorithms were compared and the best one was selected in each category. The comparison showed that the modified independent component analysis (ICA) algorithm was most effective in cancelling the traffic noise and features consisting of mel-frequency cepstral coefficients (MFCCs) had the best performance in terms of repeatability and separabillty. The condition of the bridge deck was then detected by a radial basis function (RBF) neural network. The performance of the system was evaluated using both experimental and field data. The results show that the selected algorithms increase the noise robustness of acoustic methods and perform satisfactorily if the training data is representative.

Zhang, Gang; Harichandran, Ronald S.; Ramuhalli, Pradeep

2011-09-13T23:59:59.000Z

369

Depth profiling ambient noise in the deep ocean  

E-Print Network (OSTI)

al. , 2005). The vertical profile of wind speed over the seavertical directionality…………… Depth-dependence of wind speedVertical noise directional density function versus depth. 93 Measured and acoustically estimated wind speeds.

Barclay, David Readshaw

2011-01-01T23:59:59.000Z

370

Kinetic Roughening with Algebraically Distributed Noise Amplitudes or Waiting Times  

Science Journals Connector (OSTI)

In this paper we report on numerical simulation results on Zhang’s prediction1...about the relevance of the distribution of noise amplitudes ?in kinetic surface roughening2. For power law distributions P(?) ? ?-(...

János Kertész

1993-01-01T23:59:59.000Z

371

Noise and Uniqueness of Motion by Mean Curvature  

E-Print Network (OSTI)

applications in materials science and image processing. We refer to [1,25–27] for surveys ... In this work we explore the use of noise to select a unique solution.

2004-02-03T23:59:59.000Z

372

A diffraction integral based turbomachinery noise shielding method  

E-Print Network (OSTI)

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 ...

Colas, Dorian Frederic Marie

2011-01-01T23:59:59.000Z

373

Hawaii Noise Forms and Links Webpage | Open Energy Information  

Open Energy Info (EERE)

and Links Webpage Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Hawaii Noise Forms and Links Webpage Abstract This webpage contains links to...

374

The reduction of supersonic jet noise using pulsed microjet injection  

E-Print Network (OSTI)

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 ...

Ragaller, Paul Aaron

2007-01-01T23:59:59.000Z

375

Electronic noise in nanostructures: limitations and sensing applications  

E-Print Network (OSTI)

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...

Kim, Jong Un

2007-04-25T23:59:59.000Z

376

Noise and stability of actively modelocked fiber lasers  

E-Print Network (OSTI)

The timing jitter of a modelocked laser is fundamentally limited by the amplified spontaneous emission in the laser cavity. While one cannot, even in principle, remove this source of noise, one does have control over the ...

Grein, Matthew Edward, 1970-

2002-01-01T23:59:59.000Z

377

Operation of transition-edge sensors with excess thermal noise  

Science Journals Connector (OSTI)

The superconducting transition-edge sensor (TES) is currently one of the most attractive choices for ultra-high resolution calorimetry in the keV x-ray band, and is being considered for future ESA and NASA missions. We have performed a study on the noise characteristics of Au/Ti bilayer TESs, at operating temperatures around ~100 mK, with the SQUID readout at 1.5 K. Experimental results indicate that without modifications the back-action noise from the SQUID chip degrades the noise characteristics significantly. We present a simple and effective solution to the problem: by installing an extra shunt resistor which absorbs the excess radiation from the SQUID input, we have reduced the excess thermal (photon) noise power down by approximately a factor of five, allowing high resolution operation of the sensors.

I J Maasilta; K M Kinnunen; A K Nuottajärvi; J Leppäniemi; A Luukanen

2006-01-01T23:59:59.000Z

378

Applications of broad class knowledge for noise robust speech recognition  

E-Print Network (OSTI)

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. ...

Sainath, Tara N

2009-01-01T23:59:59.000Z

379

Suppression of drift waves in a linear magnetized plasma column  

SciTech Connect

In magnetically confined fusion plasmas, drift wave driven turbulence can lead to enhanced particle transport from the plasma. Because of this, a significant research emphasis has been placed on the suppression of drift waves in the plasma edge. However, the combination of the toroidal geometry and short plasma lifetimes can make it difficult to fully characterize the properties of these instabilities. Because linear magnetized plasma devices offer a combination of simpler geometry and steady state plasma generation, it is possible to perform detailed studies of many types of plasma instabilities-including drift waves. This paper reports on a recent experiment in which low frequency instabilities ({omega} {<=} {omega}{sub ci}) in the Auburn Linear EXperiment for Instability Studies plasma device were characterized as drift waves and through changes in the parallel current, it is shown that it is possible to suppress these instabilities.

DuBois, A. M.; Eadon, A. C.; Thomas, E. Jr. [Physics Department, Auburn University, Auburn, Alabama 36849 (United States)

2012-07-15T23:59:59.000Z

380

Suppression MHD instabilities by IBW heating in HT-7 Tokamak  

E-Print Network (OSTI)

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.

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

2010-01-20T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Optical analog of Rabi oscillation suppression due to atomic motion  

E-Print Network (OSTI)

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.

J. G. Muga; B. Navarro

2005-05-13T23:59:59.000Z

382

History of noise quality in the automotive industry  

Science Journals Connector (OSTI)

This paper will present a brief look at the emerging philosophy of sound quality as viewed from within the automotive engineering community. A few examples of the concepts of sound quality will be discussed focusing on their relevance to noise control in vehicles. The paper will be primarily historical in content relating how the ideas of sound quality came to be recognized as an important factor in noise control for automobiles.

Earl Geddes

1990-01-01T23:59:59.000Z

383

Orthogonal jumps of wavefunction in white-noise potentials  

E-Print Network (OSTI)

We investigate the evolution of the quantum state for a free particle placed into a random external potential of white-noise type. The master equation for the density matrix is derived by means of path integral method. We propose an equivalent stochastic process where the wavefunction satisfies a nonlinear Schr\\"odinger equation except for random moments at which it shows orthogonal jumps. The relation of our work to the usual theory of quantum noise and damping is briefly discussed.

Lajos Diósi

2015-01-01T23:59:59.000Z

384

Suppression of large-scale perturbations by stiff solid  

E-Print Network (OSTI)

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.

Balek, Vladimír

2015-01-01T23:59:59.000Z

385

Suppression of Metallic Impurities by Electron Injection in a Tokamak  

Science Journals Connector (OSTI)

We found that the sheath potential plays a dominant role in the plasma-wall interaction in the Macrotor tokamak. An increase in the sheath potential, produced by removing electrons from the plasma, results in the enhancement of the metal influx. When the sheath potential is reduced by electron injection, the metal influx is suppressed. This mechanism may be used as a tool in controlling metallic impurities in tokamaks.

R. J. Taylor and Lena Oren

1979-02-12T23:59:59.000Z

386

Suppression of Rayleigh Taylor instability in strongly coupled plasmas  

SciTech Connect

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.

Das, Amita; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2014-06-15T23:59:59.000Z

387

The Receptor SIGIRR Suppresses Th17 Cell Proliferation via Inhibition of the Interleukin-1  

E-Print Network (OSTI)

-induced arthritis (CIA), were suppressed (Taylor, 2003; Hofstetter et al., 2005; Gonzalez-Garci´a et al., 2009

388

Characterization of wind noise by the boundary layer meteorology  

Science Journals Connector (OSTI)

The fluctuations in pressure generated by turbulent motions of the atmospheric boundary layer are a principal noise source in outdoor acoustic measurements. The mechanics of wind noise involve not only stagnation pressure fluctuations at the sensor but also shearing and self-interaction of turbulence throughout the flow particularly at low frequencies. The contributions of these mechanisms can be described by the boundary-layer meteorology. An experiment was conducted at the National Wind Institute's 200-meter meteorological tower located outside Lubbock Texas in the Llano Estacado region. For two days a 44-element 400-meter diameter array of unscreened NCPA-UMX infrasound sensors recorded wind noise continuously while the tower and a Doppler SODAR measured vertical profiles of the boundary layer. Analysis of the fluctuating pressure with the meteorological data shows that the statistical structure of wind noise depends on both mean velocity distribution and buoyant stability. The root-mean-square pressure exhibits distinct scalings for stable and unstable stratification. Normalization of the pressure power spectral density depends on the outer scales. In stable conditions the kurtosis of the wind noise increases with Reynolds number. Measures of noise intermittency are explored with respect to the meteorology.

2014-01-01T23:59:59.000Z

389

Subjective response to low?frequency aircraft noise  

Science Journals Connector (OSTI)

The standard metric currently in use by the U.S. government for community noise from aircraft is the day?night level (DNL) which is based on the A?weighting network. However residents of communities near airports have reported annoyance due to aircraft noise in greater proportion than what the DNL contour associated with their address predicts. Complaints of ‘‘distant rumbling’’ appear to be related to the low?frequency noise that aircraft produce for which the DNL metric does not fully account. This presentation discusses measurements made in October 2004 at two residences near runways at Washington?Dulles International Airport. Noise data are recorded both inside and outside the structures allowing for a measure of the events’ impact both inside and outside the structure as well as the filtering effect of the structure on the signal. Laboratory subjective evaluation studies of the recorded aircraft signatures are conducted. Objective metrics those that are designed for low?frequency noise and those that are not are calculated and correlated with subjective rankings of the signatures. This gauges the metrics’ effectiveness in predicting subjective perception of aircraft noise signatures. [Work supported by the Federal Aviation Administration and the Exploratory and Foundational Program of the Applied Research Laboratory Penn State University.

2005-01-01T23:59:59.000Z

390

Characterization of aircraft noise during thrust reverser engagement  

Science Journals Connector (OSTI)

Airport noise impact on communities has been an area of considerable study. However it has been determined that thrust reverser engagement is an area requiring further research. This paper presents findings on thrust reverser from a noise study done at Washington?Dulles International Airport (IAD) in October of 2004. Previous studies have found that high levels of acoustic energy in commercial aircraft during takeoff are contained below 300 Hz [Sharp Ben H. Guovich Yuri A. and Albee William W. ‘‘Status of Low?Frequency Aircraft Noise Research and Mitigation ’’ Wyle Report WR 01?21 San Francisco September 2001]. Preliminary analysis of thrust reverser signatures indicates similar findings. A categorization of aircraft noise during thrust reverser engagement is given and looks at factors that may affect the noise characteristics. Some of these factors include: plane type engine type and thrust ratings. In addition a brief analysis of frequency weightings of the Equivalent Sound Level (Leq) and Sound Exposure Level (SEL) metrics and their application to thrust reverser noise is discussed. [Work supported by the Federal Aviation Administration.

2005-01-01T23:59:59.000Z

391

Depth dependence of ambient noise in the northeastern Pacific Ocean  

Science Journals Connector (OSTI)

Omnidirectional ambient noise levels were measured at two deep?water locations in the northeastern Pacific Ocean.Hydrophones were positioned throughout the water column at depths ranging from about 200 m below the surface to about 150 m above the sea bottom. Analyses of the data over the frequencies from 15 to 800 Hz show that at low frequencies the noise levels decrease with increasing depth. The decrease with depth is greater below the critical depth than it is in the sound channel. These low?frequency noise levels and their depth dependence are independent of the wind speed. At higher frequencies the noise levels and the depth dependence are controlled by the wind?generated noise. At low wind speeds there is a decrease in levels below the critical depth but above this depth both increases and decreases in levels with depth were noted. At these high frequencies during high wind speeds the noise levels not only rise but also fill the water column to the extent that there is little decrease in level with increasing depth even for the region below the critical depth.

Gerald B. Morris

1978-01-01T23:59:59.000Z

392

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)

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...

Baluev, Roman V

2014-01-01T23:59:59.000Z

393

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

E-Print Network (OSTI)

of Computational Aero-acoustics, Phil Joseph, Professor of acoustical engineering and turbo-machinery noise and Dr aircraft worth £2.0 trillion; the UK will retain or expand its current 17 per cent share of this m

Sóbester, András

394

Novel Feeding Topologies for 2nd Harmonic Suppression in Broadband Microstrip Patch Antennas  

E-Print Network (OSTI)

Novel Feeding Topologies for 2nd Harmonic Suppression in Broadband Microstrip Patch Antennas *Il harmonic suppression property, while allowing for a broadband operation of microstrip patch antennas as well as a good 2nd harmonic suppression property. I. Introduction Microstrip patch antennas are very

Tentzeris, Manos

395

Noise-like pulse based on dissipative four-wave-mixing with photonic crystal fiber filled by reduced graphene oxide  

E-Print Network (OSTI)

A noise-like pulse based on dissipative four-wave-mixing in a fiber cavity with photonic crystal fiber filled by reduced graphene oxide is proposed. Due to large evanescent field provided by 3 cm photonic crystal fiber and ultrahigh nonlinearity of reduced graphene oxide, this mixed structure provides excellent saturable absorption and high nonlinearity, which are necessary for generating four-wave-mixing (FWM). We experimentally prove that the mode-locked laser transfers its energy from center wavelength to sidebands through degenerate FWM, and new frequencies are generated via cascaded FWM among those sidebands. During this process, the frequencies located in various orders of longitudinal modes of the ring cavity are supported, and others are suppressed due to destructive interference. As the longitudinal modes of the cavity with a spacing of 6.874 MHz are partially supported, the loosely fixed phase relationship results in noise-like pulse with a coherent peak of 530 fs locating on a pedestal of 730.693 p...

Gao, Lei; Huang, Wei

2014-01-01T23:59:59.000Z

396

NOISE CONTROL METHODS FOR A RECIPROCATING AIR COMPRESSOR USED IN FUEL CELL AUXILIARY POWER UNIT (APU)  

E-Print Network (OSTI)

NOISE CONTROL METHODS FOR A RECIPROCATING AIR COMPRESSOR USED IN FUEL CELL AUXILIARY POWER UNIT Air pollution Noise pollution Engine life Remedy Fuel cell APU Quieter Low emissions Exhaust Heat, Case History: Noise control approaches for an air-compressor in a fuel-cell auxiliary power unit, Noise

Carver, Jeffrey C.

397

Experimental Cryogenic Modeling and Noise of SiGe HBTs Joseph C. Bardin and Sander Weinreb  

E-Print Network (OSTI)

Experimental Cryogenic Modeling and Noise of SiGe HBTs Joseph C. Bardin and Sander Weinreb contender for extremely low noise, cryogenically cooled amplifiers. This paper begins with a procedureGe), cryogenic, low noise amplifier (LNA), noise parameters, transistor modeling. I. INTRODUCTION Very low

Weinreb, Sander

398

Estimation of uncertainties due to the wind-induced noise in a screened microphone  

E-Print Network (OSTI)

for experimental assessment of wind turbine noise. The contribution of the wind noise introduces a biasEstimation of uncertainties due to the wind-induced noise in a screened microphone D. Ecotiere by the wind at a screened microphone. This noise originates from turbulences that come from the direct

Paris-Sud XI, Université de

399

Comprehensive study of noise processes in electrode electrolyte interfaces Arjang Hassibi,a)  

E-Print Network (OSTI)

, with emphasis on its implications for electrochemical sensors. The noise power spectral densities associated produced by electrochemical interactions. The power spectral density of the thermal equilibrium noise in sensing electrodes, shot noise in electrochemical batteries, and 1/f noise in corrosive interfaces

Lee, Thomas H.

400

High-level numerical simulations of noise in CCD and CMOS photosensors: review and tutorial  

E-Print Network (OSTI)

In many applications, such as development and testing of image processing algorithms, it is often necessary to simulate images containing realistic noise from solid-state photosensors. A high-level model of CCD and CMOS photosensors based on a literature review is formulated in this paper. The model includes photo-response non-uniformity, photon shot noise, dark current Fixed Pattern Noise, dark current shot noise, offset Fixed Pattern Noise, source follower noise, sense node reset noise, and quantisation noise. The model also includes voltage-to-voltage, voltage-to-electrons, and analogue-to-digital converter non-linearities. The formulated model can be used to create synthetic images for testing and validation of image processing algorithms in the presence of realistic images noise. An example of the simulated CMOS photosensor and a comparison with a custom-made CMOS hardware sensor is presented. Procedures for characterisation from both light and dark noises are described. Experimental results that confirm...

Konnik, Mikhail

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Self Excited Vibration in a Specialised Electric Propulsion System  

Science Journals Connector (OSTI)

Special marine propulsion applications demand efficient manoeuvrability under extreme conditions. ... , vibration resonance and radiated noise from the propulsion shafting system must be kept to a ... purpose ves...

Don Chool Lee; Ronald D. Barro

2014-09-01T23:59:59.000Z

402

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)

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...

Bradham, S.; Stephan, R.

403

THE HYPOTHETICAL EFFECTS ON VADOSE ZONE & GROUNDWATER CONTAMINATION BY FIRE SUPPRESSION OF HANFORD SITE BUILDINGS AWAITING DECOMMISSIONING  

SciTech Connect

Numerical modeling was used to assess the effects of nearby contamination of hypothetical fire-suppression activities. The modeling focused on the 333 Building as being representative of a ''worst case'' situation in deactivated buildings at the Hanford Nuclear Site in Washington State. For purposes of the analysis, the fire-suppression sprinkler systems of these buildings were assumed to have been deactivated, requiring that the hypothetical fires be extinguished using water supplied by nearby fire hydrants. The amount of water specified by Fire-Protection personnel as needed to extinguish a hypothetical fire was specified as 1,500 gpm for 2 hours, for a total of 180,000 gallons or about 681 m{sup 3}.

DAVIS, J.D.

2005-03-18T23:59:59.000Z

404

Noise and vibration characteristics of cleanroom fan filter units  

Science Journals Connector (OSTI)

Fan filter units (FFU’s) are used increasingly by the microelectronics industry to provide recirculation air in cleanrooms. Such units usually consist of one or more direct?drive blowers located in a small discharge plenum and a HEPA or ULPA filter. There may be several hundred FFU’s in a large cleanroom. The noise and vibration generated by FFU’s differ greatly between manufacturers. Since it is difficult to apply external noise and vibration mitigation it is important to select an FFU model with appropriate noise and vibration levels so that a cleanroom served by these units will meet the prespecified noise and vibration criteria. Unfortunately FFU manufacturers usually do not provide enough information for predicting the FFU generated sound?pressure spectrum or vibration in a cleanroom. In this paper simple noise and vibration measurement methods will be described which can be used as a basis for specifying FFU performance without special testing facilities. Measured data will be presented for a number of units. Procedures will be demonstrated to predict the performance of a cleanroom which uses FFU’s as the primary source of recirculation air.

Mei Q. Wu; Colin G. Gordon

1998-01-01T23:59:59.000Z

405

Digital noise generators using one-dimensional chaotic maps  

SciTech Connect

This work shows how to improve the statistical distribution of signals produced by digital noise generators designed with one-dimensional (1-D) chaotic maps. It also shows that in a digital electronic design the piecewise linear chaotic maps (PWLCM) should be considered because they do not have stability islands in its chaotic behavior region, as it occurs in the case of the logistic map, which is commonly used to build noise generators. The design and implementation problems of the digital noise generators are analyzed and a solution is proposed. This solution relates the output of PWLCM, usually defined in the real numbers' domain, with a codebook of S elements, previously defined. The proposed solution scheme produces digital noise signals with a statistical distribution close to a uniform distribution. Finally, this work shows that it is possible to have control over the statistical distribution of the noise signal by selecting the control parameter of the PWLCM and using, as a design criterion, the bifurcation diagram.

Martínez-Ñonthe, J. A; Palacios-Luengas, L.; Cruz-Irisson, M.; Vazquez Medina, R. [Instituto Politécnico Nacional, ESIME-Culhuacan, Santa Ana 1000, 04430, D.F. (Mexico); Díaz Méndez, J. A. [Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro 1, Tonantzintla, Puebla (Mexico)

2014-05-15T23:59:59.000Z

406

Subtraction-noise projection in gravitational-wave detector networks  

SciTech Connect

In this paper, we present a successful implementation of a subtraction-noise projection method into a simple, simulated data analysis pipeline of a gravitational-wave search. We investigate the problem to reveal a weak stochastic background signal which is covered by a strong foreground of compact-binary coalescences. The foreground, which is estimated by matched filters, has to be subtracted from the data. Even an optimal analysis of foreground signals will leave subtraction noise due to estimation errors of template parameters which may corrupt the measurement of the background signal. The subtraction noise can be removed by a noise projection. We apply our analysis pipeline to the proposed future-generation space-borne Big Bang Observer mission which seeks for a stochastic background of primordial gravitational waves in the frequency range {approx}0.1 Hz--1 Hz covered by a foreground of black-hole and neutron-star binaries. Our analysis is based on a simulation code which provides a dynamical model of a time-delay interferometer network. It generates the data as time series and incorporates the analysis pipeline together with the noise projection. Our results confirm previous ad hoc predictions which say that the Big Bang Observer will be sensitive to backgrounds with fractional energy densities below {omega}=10{sup -16}.

Harms, Jan; Mahrdt, Christoph; Otto, Markus; Priess, Malte [Institut fuer Gravitationsphysik, Universitaet Hannover and Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, 30167 Hannover (Germany)

2008-06-15T23:59:59.000Z

407

Radiated noise characteristics of a modern cargo ship  

Science Journals Connector (OSTI)

Extensive measurements were made of the radiated noise of M/V OVERSEAS HARRIETTE a bulk cargo ship (length 173 m displacement 25?515 tons) powered by a direct-drive low-speed diesel engine—a design representative of many modern merchant ships. The radiated noise data show high-level tonal frequencies from the ship’s service diesel generator main engine firing rate and blade rate harmonics due to propeller cavitation. Radiated noise directionality measurements indicate that the radiation is generally dipole in form at lower frequencies as expected. There are some departures from this pattern that may indicate hull interactions. Blade rate source level (174 dB re 1 ?Pa/m at 9 Hz 16 knots) agrees reasonably well with a model of fundamental blade rate radiation previously reported by Gray and Greeley but agreement for blade rate harmonics is not as good. Noise from merchant ships elevates the natural ambient by 20–30 dB in many areas; the effects of this noise on the biological environment have not been widely investigated.

Paul T. Arveson; David J. Vendittis

2000-01-01T23:59:59.000Z

408

Wind farm—Long term noise and vibration measurements  

Science Journals Connector (OSTI)

Most of the energy produced in Quebec comes from renewable sources. The concept of wind energy emerged in the late 1990’s and has since become a complementary source of energy alongside hydroelectricity. Wind farms are generally seen as a good sustainable way to produce energy. However they are not implemented without some impact on the environment. SNC-Lavalin Environment has performed many surveys in recent years for wind farm projects including noise measurements both before and after their commissioning. This presentation will give an overview of one such project where long term noise and vibration measurements where conducted. Vibration measurements as well as outdoor indoor and low frequencies noise measurements were completed both with and without the wind turbines in operation. Data will be presented showing different problems encountered in the analysis phase. For example multiple intermittent and non-steady noise sources were present during measurement (wind turbines car pass-bys wind in the trees human activities). Methods used to overcome these obstacles will be discussed (use of statistical parameters linear regression) and the effect of the wind turbine operation on the noise level (including low frequencies) and vibration level will be presented.

2013-01-01T23:59:59.000Z

409

Wind Farm - Long term noise and vibration measurements  

Science Journals Connector (OSTI)

Most of the energy produced in Quebec comes from renewable sources. The concept of wind energy emerged in the late 1990's and has since become a complementary source of energy alongside hydroelectricity. Wind farms are generally seen as a good sustainable way to produce energy. However they are not implemented without some impact on the environment. SNC-Lavalin Environment has performed many surveys in recent years for wind farm projects including noise measurements both before and after their commissioning. This presentation will give an overview of one such project where long term noise and vibration measurements where conducted. Vibration measurements as well as outdoor indoor and low frequencies noise measurements were completed both with and without the wind turbines in operation. Data will be presented showing different problems encountered in the analysis phase. For example multiple intermittent and non-steady noise sources were present during measurement (wind turbines car pass-bys wind in the trees human activities). Methods used to overcome these obstacles will be discussed (use of statistical parameters linear regression) and the effect of the wind turbine operation on the noise level (including low frequencies) and vibration level will be presented.

Martin Meunier

2013-01-01T23:59:59.000Z

410

Modeling of offshore wind turbine noise radiation and propagation  

Science Journals Connector (OSTI)

Noisegenerated by offshore wind turbine and support structure can radiate and propagate through the air water and sediment. Predicting noise levels around wind turbinestructures at sea is required for the estimation of effects of the noise on marine life. To predict radiated noise we used a finite element analysis(FEA) of a cylindrical shell model of a monopile structure. In the finite element modeling transient modal dynamic analysis and steady state dynamic analysis (direct and modal) were implemented to simulate both construction and operational noise. The effect of various sediment types and foundation designs are investigated. The FEA package used was ABAQUS version 6.10. The output of the FEAanalysis is used as starting field for acoustic propagation models such as PE to produce long range predictions. We present predictions of particle velocity at the structure-acoustic medium interface and sound pressure level as function of frequency at various distances from the structure. Laboratory experiments using scale models of the cylindrical shell have been carried out to verify the noise predictions. Comparison of the FEAmodel results and experimental data will be presented.

Huikwan Kim; Gopu R. Potty; James H. Miller; Christopher Baxter

2011-01-01T23:59:59.000Z

411

Strangeness Suppression of qq? Creation Observed in Exclusive Reactions  

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.

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

412

M3 Suppression in Hartree-Fock Theory  

Science Journals Connector (OSTI)

With a zero-range interaction a valence spin-up neutron will not interact with core spin-up neutrons and hence will not deform them; it will deform spin-down neutrons. This introduces a spin-quadrupole correlation. An ideal operator for probing this correlation is the M3 operator, since this operator is crudely E2×M1. The suppression of the M3 moment in O17 due to this effect, as well as due to the spin dependence of the interaction, is considered.

Larry Zamick

1978-02-06T23:59:59.000Z

413

Wind noise and the spectrum of atmospheric turbulence pressure fluctuations  

Science Journals Connector (OSTI)

Previous research [S. Morgan and R. Raspet J. Acoust. Soc. Am. 92 1180–1183 (1992)] has shown that wind noise is predominantly caused by pressure fluctuations intrinsic to the turbulent atmospheric flow. Therefore it should be possible to predict wind noise from models for turbulent pressure spectra in the atmosphere. Based on simple dimensional analysis and an application of Taylor’s hypothesis the inertial?subrange power spectrum for turbulent pressure fluctuations should be proportional to f ?7/3 where f is frequency. But more recent atmospheric observations and theoretical arguments [J. D. Albertson G. G. Katul M. B. Parlange and W. E. Eichinger Phys. Fluids 10 1725–1732 (1998)] suggest that the power spectrum actually goes as f ?3/2. In this paper it is shown that the f ?3/2 dependence predicts a much slower decay in wind noise with increasing acoustic frequency than is typically observed. Possible reasons for this discrepancy are discussed.

2003-01-01T23:59:59.000Z

414

Philosophical viewpoints on noise from wind power projects.  

Science Journals Connector (OSTI)

Many people are involved with evaluating engineering developing and opposing wind power projects. While there are many worldviews on global warming renewable energy and green technologies this paper focuses on the philosophical viewpoints surrounding noise from wind power projects. After identifying various stakeholders the paper investigates how some great historical and current minds have contributed likely unknowingly to this field including Gifford Pinchot John Muir Jonathan Edwards Mark Sagoff Bryan Norton and Cass Sunstein. A brief review of the history of noise in the rural environment comparing transportation noise with wind turbinenoise will be provided. The relation between cost?benefit analysis the precautionary principle and wind powernoise ordinances will be discussed. The paper will wrap up with some thoughts of what Sagoff may have to offer regarding NIMBYism and why Nortons call for convergence is also a call for acousticians to practice good science.

Edward C. D. Duncan

2011-01-01T23:59:59.000Z

415

Controlling the turbocharger whistling noise in diesel engines  

Science Journals Connector (OSTI)

Turbochargers are now commonly used in passenger cars especially in application with diesel engines because of their numerous advantages. The use of this machine greatly improves engine performance, while at the same time allowing pollutant emissions to be reduced. However, one of the important issues to take into account when a turbocharger is used in passenger cars is the whistling noise due to unbalanced forces that can be perceived by the driver, which causes discomfort. The manufacturer's efforts to reduce the whistling noise are centred on reducing the unbalanced forces by a correct balance of rotating parts. However, improving the balance means increasing the manufacturing cost as this process is very expensive. Selecting the maximum unbalance admissible is a key activity during the development of a new application. In this paper, a procedure to control the turbocharger whistling noise vs. unbalanced forces variation has been suggested in order to maintain the acoustic comfort of the vehicle.

J.A. Calvo; V. Diaz; J.L. San Roman

2006-01-01T23:59:59.000Z

416

Wideband noise observed at ground level in the auroral region  

SciTech Connect

A sideband noise event was detected at ground level from the Andoya Rocket Range in Norway in January 1989. The signals were observed on four commercial communication receivers (tuned to 159, 515, 905, and 1200 kHz), an ionosonde (200-kHz to 3.5-MHz interference-free observations) and a riometer (32.5 MHz). The event, which occurred during a period of magnetic disturbance near magnetic midnight, was the only one observed during nearly 3 weeks of operations. This low frequency-of-occurrence is attributed partly to high local noise levels. The ease with which this event was identified on the ionograms produced by the local ionosonde suggests that routine ionosonde recordings should be inspected in search for such events. Such an effort would enhance existing research directed toward developing techniques for identifying quiet communication channels and help to identify the origin and frequency-of-occurrence of high-latitude wideband noise events. 20 refs.

Benson, R.F.; Desch, M.D. (NASA, Goddard Space Flight Center, Greenbelt, MD (United States))

1991-08-01T23:59:59.000Z

417

Ocean noise in the tropical and subtropical Pacific Ocean  

Science Journals Connector (OSTI)

Ocean ambient noise is well studied in the North Pacific and North Atlantic but is poorly described for most of the worlds' oceans. Calibrated passive acoustic recordings were collected during 2009–2010 at seven locations in the central and western tropical and subtropical Pacific. Monthly and hourly mean power spectra (15–1000?Hz) were calculated in addition to their skewness kurtosis and percentile distributions. Overall ambient noise at these seven sites was 10–20?dB lower than reported recently for most other locations in the North Pacific. At frequencies 200?Hz with higher levels recorded in the winter than in the summer. Several species of baleen whales humpback (Megaptera novaeangliae) blue (Balaenoptera musculus) and fin (B. physalus) whales also contributed seasonally to ambient noise in characteristic frequency bands.

Ana Širovi?; Sean M. Wiggins; Erin M. Oleson

2013-01-01T23:59:59.000Z

418

Study on impulsive noise radiation from of gasoline direct injector  

Science Journals Connector (OSTI)

A gasoline direct injection (GDI) engine uses its own injectors for high pressure fuel supply to the combustion chamber. High frequency impact sound during the injection process is one of the main contributors to engine combustion noise. This impact noise is generated during opening and closing by an injector rod operated by a solenoid. For design of an injector with reduced noise generation it is necessary to analyze its sound radiation mechanism and propose consequent evaluation method. Spectral and modal characteristics of the injectors were measured through vibration induced by external hammer excitation. The injector modal characteristics were analyzed using a simple beam after analyzing its boundaries by complex transverse and rotational springs. To evaluate impulsive sounds more effectively Prony analysis of sounds was used for verifying influence of injector modal characteristics.

2014-01-01T23:59:59.000Z

419

Review of Subcritical Source-Driven Noise Analysis Measurements  

SciTech Connect

Subcritical source-driven noise measurements are simultaneous Rossi-{alpha} 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 Rossi-{alpha} 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. More elaborate models can also be developed using a generalized stochastic model. These measurements can be simulated using Monte Carlo codes to determine the subcritical neutron multiplication factor or to determine the sensitivity of calculations to nuclear cross section data. The interpretation of the measurement using a Monte Carlo method is based on a perturbation model for the relationship between the spectral ratio and the subcritical neutron multiplication factor. The subcritical source-driven noise measurement has advantages over other subcritical measurement methods in that reference measurements at delayed critical are not required for interpreting the measurements. Therefore, benchmark or in-situ subcritical measurements can be performed outside a critical experiment facility. Furthermore, a certain ratio of frequency spectra has been shown to be independent of detection efficiency thereby making the measurement more robust and unaffected by drifts or changes in instrumentation during the measurement. Criteria have been defined for application of this measurement method for benchmarks and in-situ subcritical measurements. An extension of the source-driven subcritical noise measurement has also been discussed that eliminates the few technical challenges for in-situ applications.

Valentine, T.E.

1999-11-24T23:59:59.000Z

420

Green Noise or Green Value? Measuring the Effects of Environmental  

NLE Websites -- All DOE Office Websites (Extended Search)

Noise or Green Value? Measuring the Effects of Noise or Green Value? Measuring the Effects of Environmental Certification on Office Values Secondary menu About us Press room Contact Us Portfolio Manager Login Facility owners and managers Existing buildings Commercial new construction Industrial energy management Small business Service providers Service and product providers Verify applications for ENERGY STAR certification Design commercial buildings Energy efficiency program administrators Commercial and industrial program sponsors Associations State and local governments Federal agencies Tools and resources Training In This Section Campaigns Commercial building design Communications resources Energy management guidance Financial resources Portfolio Manager Products and purchasing Recognition Research and reports Service and product provider (SPP) resources

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Nonlocal Kardar-Parisi-Zhang equation with spatially correlated noise  

Science Journals Connector (OSTI)

The effects of spatially correlated noise on a phenomenological equation equivalent to a nonlocal version of the Kardar-Parisi-Zhang (KPZ) equation are studied via the dynamic renormalization group (DRG) techniques. The correlated noise coupled with the long ranged nature of interactions prove the existence of different phases in different regimes, giving rise to a range of roughness exponents defined by their corresponding critical dimensions. Finally self-consistent mode analysis is employed to compare the non-KPZ exponents obtained as a result of the long-range interactions with the DRG results.

Amit Kr. Chattopadhyay

1999-07-01T23:59:59.000Z

422

Standby gen-set meets increased noise, exhaust emissions standards  

SciTech Connect

Atlantic Detroit Diesel-Allison worked with Floyd Manufacturing to develop an enclosure that would address the noise and exhaust requirements for standby generator sets. Specially designed sound baffles knock down the sound in critical areas. An architectural sound insulated wall further isolates the noise. The installation is equipped with a DeSOP oxidation silencer with a sound attenuation rating of 53 dB(A). The silencer incorporates a catalytic converter that reduces CO, VOC, SO[sub 2] and particulates in the 80 to 90% range. Diesel odor is virtually eliminated. 3 figs.

McNeely, M.

1994-10-01T23:59:59.000Z

423

Phase noise and laser-cooling limits of optomechanical oscillators  

Science Journals Connector (OSTI)

The noise from laser phase fluctuation sets a major technical obstacle to cool the nanomechanical oscillators to the quantum region. We propose a cooling configuration based on the optomechanical coupling with two cavity modes to significantly reduce this phase noise by (2?m/?)2 times, where ?m is the frequency of the mechanical mode and ? is the decay rate of the cavity mode. We also discuss the detection of the phonon number when the mechanical oscillator is cooled near the quantum region and specify the required conditions for this detection.

Zhang-qi Yin

2009-09-14T23:59:59.000Z

424

Evaluation of occupational noise exposure using a wireless microphone  

E-Print Network (OSTI)

August 1973l Major Subject: Industrial Hygiene EVALUATION OF OCCUPATIONAL NOISE EXPOSURE USING A WIRELESS MICROPHONE A Thesis by ROBERT BACOT NASH, JR. Approved as to style and content by: Cha man of mmit e Z~ Kv-~ Head of Department Member... Member August 1/74 ABSTRACT Evaluation of Occupational Noise Exposure Using a Wireless Microphone. (August 1974) Robert Bacot Nash, Jr. , B. S. , Texas A8cM University Chairman of Advisory Committee: Dr, Richard B. Konzen The output of a Vega...

Nash, Robert Bacot

2012-06-07T23:59:59.000Z

425

Suppression of Zeeman gradients by nuclear polarization in double quantum dots  

E-Print Network (OSTI)

We use electric dipole spin resonance to measure dynamic nuclear polarization in InAs nanowire quantum dots. The resonance shifts in frequency when the system transitions between metastable high and low current states, indicating the presence of nuclear polarization. We propose that the low and the high current states correspond to different total Zeeman energy gradients between the two quantum dots. In the low current state, dynamic nuclear polarization efficiently compensates the Zeeman gradient due to the $g$-factor mismatch, resulting in a suppressed total Zeeman gradient. We present a theoretical model of electron-nuclear feedback that demonstrates a fixed point in nuclear polarization for nearly equal Zeeman splittings in the two dots and predicts a narrowed hyperfine gradient distribution.

S. M. Frolov; J. Danon; S. Nadj-Perge; K. Zuo; J. W. W. van Tilburg; V. S. Pribiag; J. W. G. van den Berg; E. P. A. M. Bakkers; L. P. Kouwenhoven

2012-09-07T23:59:59.000Z

426

A major hindrance to rendering spoken dialog systems capable of ongoing, continuous listening without requiring a push-to-  

E-Print Network (OSTI)

, if the system is responding to a request and the user coughs or some other background noise is heard, the system

Horvitz, Eric

427

Low-noise detector and amplifier design for 100 ns direct detection CO{sub 2} LIDAR receiver  

SciTech Connect

The development and test results of a prototype detector/amplifier design for a background limited, pulsed 100 ns, 10--100 kHz repetition rate LIDAR/DIAL receiver system are presented. Design objectives include near-matched filter detection of received pulse amplitude and round trip time-of-flight, and the elimination of excess correlated detector/amplifier noise for optimal pulse averaging. A novel pole-zero cancellation amplifier, coupled with a state-of-the-art SBRC (Santa Barbara Research Center) infrared detector was implemented to meet design objectives. The pole-zero cancellation amplifier utilizes a tunable, pseudo-matched filter technique to match the width of the laser pulse to the shaping time of the filter for optimal SNR performance. Low frequency correlated noise, (l/f and drift noise) is rejected through a second order high gain feedback loop. The amplifier also employs an active detector bias stage minimizing detector drift. Experimental results will be provided that demonstrate near-background limited, 100 ns pulse detection performance given a 8.5--11.5 {micro}m (300 K B.B.) radiant background, with the total noise floor spectrally white for optimal pulse averaging efficiency.

Cafferty, M.M.; Cooke, B.J.; Laubscher, B.E.; Olivas, N.L.; Fuller, K.

1997-06-01T23:59:59.000Z

428

Spin noise spectroscopy to probe quantum states of ultracold fermionic atom gases  

SciTech Connect

We theoretically demonstrate that optical measurements of electron spin noise can be a spectroscopic probe of the entangled quantum states of ultracold fermionic atom gases and unambiguously reveal the detailed nature of the underlying interatomic correlations. Different models of the effective interatomic interactions predict entirely new sets of resonances in the spin noise spectrum. Once the correct effective interatomic interaction model is identified, the detailed noise line shapes of the spin noise can be used to constrain this model. We estimate the magnitude of spin noise signals expected in ultracold fermionic atom gases via noise measurements in classical alkali vapors, which demonstrate the feasibility of this approach.

Mihaila, Bogdan; Blagoev, Krastan B.; Smith, Darryl L. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Crooker, Scott A.; Rickel, Dwight G. [National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Littlewood, Peter B. [Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE (United Kingdom)

2006-12-15T23:59:59.000Z

429

Assessment of annoyance due to wind turbine noise  

Science Journals Connector (OSTI)

The overall aim of this study was to evaluate the perception and annoyance of noise from wind turbines in populated areas of Poland. The study group comprised 156 subjects. All subjects were interviewed using a questionnaire developed to enable evaluation of their living conditions including prevalence of annoyance due to noise from wind turbines and the self-assessment of physical health and wellbeing. In addition current mental health status of respondents was assessed using Goldberg General Health Questionnaire GHQ-12. For areas where respondents lived A-weighted sound pressure levels (SPLs) were calculated as the sum of the contributions from the wind power plants in the specific area. It has been shown that the wind turbine noise at the calculated A-weighted SPL of 30?48 dB was perceived as annoying outdoors by about one third of respondents while indoors by one fifth of them. The proportions of the respondents annoyed by the wind turbine noise increased with increasing A-weighted sound pressure level. Subjects' attitude to wind turbines in general and sensitivity to landscape littering was found to have significant impact on the perceived annoyance. Further studies are needed including a larger number of respondents before firm conclusions can be drawn.

Malgorzata Pawlaczyk-Luszczynska; Kamil Zaborowski; Malgorzata Zamojska; Malgorzata Waszkowska

2013-01-01T23:59:59.000Z

430

Assessment of annoyance due to wind turbine noise  

Science Journals Connector (OSTI)

The overall aim of this study was to evaluate the perception and annoyance of noise from wind turbines in populated areas of Poland. The study group comprised 378 subjects. All subjects were interviewed using a questionnaire developed to enable evaluation of their living conditions including prevalence of annoyance due to noise from wind turbines and the self-assessment of physical health and well-being. In addition current mental health status of respondents was assessed using Goldberg General Health Questionnaire GHQ-12. For areas where respondents lived A-weighted sound pressure levels (SPLs) were calculated as the sum of the contributions from the wind power plants in the specific area. It has been shown that the wind turbine noise at the calculated A-weighted SPL of 30?50 dB was perceived as annoying outdoors by about one third of respondents while indoors by one fifth of them. The proportions of the respondents annoyed by the wind turbine noise increased with increasing A-weighted sound pressure level. Subjects’ attitude to wind turbines in general and sensitivity to landscape littering was found to have significant impact on the perceived annoyance. Further studies are needed including a larger number of respondents before firm conclusions can be drawn.

2013-01-01T23:59:59.000Z

431

Evaluation of wind turbine noise levels and impact studies  

Science Journals Connector (OSTI)

Measured A?weighted sound levels at 125?ft distance for individual wind turbines with 20? to 120?kW power ratings are typically in the range 65–75 dB at moderate to high power output conditions (20–30?mph wind speeds). Tonelike sounds in the 300? to 1000?Hz frequency range often are clearly audible. Cyclical fluctuations of 10 dB in low?frequency noise levels are propagated by some downwind?type turbines. The random aerodynamic rotor noisesounds like a roar the gear box noisesounds like a whine and the low?frequency noise fluctuations sound like “thump?thump” or “whoosh?whoosh.” All of these wind turbinenoises are propagated from existing wind farms to residential areas and are judged intrusive and annoying. Measurements and predictions of wind turbinenoise submitted with applications for wind farm development have often contained errors which understated the noise levels by 3–10 dB. These errors were due to noisemeasurements at minimal wind speeds and turbine power and faulty modeling procedures. Simple analytical expressions have been developed which quickly and accurately predict the noise levels for large turbine arrays.

Samuel R. Lane

1986-01-01T23:59:59.000Z

432

Intermittency and low frequency noise in a Josephson junction  

SciTech Connect

The bifurcation, chaos, and intermittency in the {ital f}-biased Josephson junction are investigated by numerically integrating the equation of the Stewart-McCumber model with an interference {epsilon} cos {phi}'' term. In addition, the relationship between the low frequency noise and the routes to chaos in a Josephson junction is discussed.

Xiao Wanru (Physics Division, Nanjing Architectural Institute (CN)); Yao Xixian (Department of Physics, Nanjing University (CN))

1990-01-01T23:59:59.000Z

433

Quantum Error Correction of Continuous Variable States against Gaussian Noise  

E-Print Network (OSTI)

We describe a continuous variable error correction protocol that can correct the Gaussian noise induced by linear loss on Gaussian states. The protocol can be implemented using linear optics and photon counting. We explore the theoretical bounds of the protocol as well as the expected performance given current knowledge and technology.

T. C. Ralph

2011-05-22T23:59:59.000Z

434

Turbulence intensity pulse propagation with self-consistent nonlinear noise  

SciTech Connect

A model of turbulence intensity spreading with self-consistent nonlinear noise is derived systematically for the simple dynamical model of resistivity gradient driven turbulence. Local effective drive, thermal conduction damping, nonlinear coupling, and spatial scattering effects are included. As a consequence of nonlinear mode coupling processes (i.e., triad mode interactions), turbulence energy can be spatially scattered, leading to turbulence propagation and spreading. However, the range of any nonlinear mode interactions of the background with a test mode is restricted to within a few mode scale widths from the test mode rational surface. The speed of a turbulent spreading front is calculated. This front speed is effectively constant on macroscopic scales. We show that the effect of self-consistent nonlinear noise on the intensity front speed is modest, as a consequence of the ordering {Delta}{sub c}noise and ad hoc external noise are discussed. The broader implications of these results for turbulence front propagation are identified and explained.

Wang, Z. H. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Department of Physics and Center for Astrophysics and Space Sciences, University of California at San Diego, La Jolla, California 92093-0424 (United States); Diamond, P. H. [Department of Physics and Center for Astrophysics and Space Sciences, University of California at San Diego, La Jolla, California 92093-0424 (United States); WCI Center for Fusion Theory, National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Guercan, Oe. D. [Laboratoire de Physique des Plasmas, Ecole Polytechnique-CNRS, 91128 Palaiseau Cedex (France); Garbet, X. [CEA, IRFM, F-13108 Saint Paul Lez Durance (France); Wang, X. G. [School of Physics, Peking University, Beijing 100871 (China)

2011-03-15T23:59:59.000Z

435

Topical Review Fluctuations and Fractal Noise in Biological Membranes  

E-Print Network (OSTI)

and transport of ions and molecules across biological membranes. We know that ion transport through mem- branes in electrical properties associated with cell membrane ion transport. Key words: Brownian motion -- Cell membrane elec- trical properties -- Fractals -- Gaussian noise -- Ion transport -- Nonlinear dynamics

436

Directivity and spectral characteristics of aircraft noise during landing operations  

Science Journals Connector (OSTI)

Recordings of aircraft landing operations have been analyzed to obtain directivity and spectralcharacteristics of the noise emitted during these operations. The recordings were made with a widely spaced microphone array positioned near and parallel to the 19R runway at Washington?Dulles International Airport. In addition the landings were recorded with a video camera to obtain positional data of the aircraft. Given an aircraft’s position and velocity along the runway the signal at each microphone is corrected for retarded time spherical spreading and Doppler shift. The corrected signals are combined to establish a directivity pattern and third?octave analysis is performed to obtain spectralcharacteristics. The results of this analysis are intended to be used as input to airport noise modeling software such as the Integrated Noise Model (INM) which currently models landing noise using forward?thrust input data. The current analysis should provide more realistic directivity and spectra for the reverse?thrust condition. [Work supported by the Federal Aviation Administration and the Applied Research Laboratory Exploratory and Foundational Research Program.

2007-01-01T23:59:59.000Z

437

RENOIR -A Benchmark Dataset for Real Noise Reduction Evaluation  

E-Print Network (OSTI)

1 RENOIR - A Benchmark Dataset for Real Noise Reduction Evaluation Josue Anaya, Adrian Barbu Abstract--In this paper we introduce a dataset of uncom- pressed color images taken with three digital and in intensity. The dataset contains over 100 scenes and more than 400 images, including both RAW formatted

Barbu, Adrian

438

Noise and health in the Greater Rotterdam Area  

Science Journals Connector (OSTI)

In the Greater Rotterdam Area a second study to Noise and Health has been carried out in 2007 and 2008. In 2003 a first study was carried out and that study reported that around 12 percent of the people living in the Greater Rotterdam Area were highly annoyed by noise mainly caused by traffic. The number of people sleep was disturbed and suffered high blood pressure were reported and amounted to 6 percent for sleep disturbance and 3 percent were suffering hypertension. The 2003 study took place within the regularly framework of the Rotterdam Regional Council of Governments Environmental Monitoring program a program that reports yearly the environmental performance indicators in the Greater Rotterdam Area. Beside this yearly report a theme report is published. Last year's theme reports were published about Air Quality and Energy. In 2007 the board of this program decided that in 2008 the theme should be Noise and Health. The 2008 study is not only an update of the 2003 study but is more detailed and more comprehensive as well and based on recent insights in health effects caused by long lasting noise too.

Henk Wolfert

2008-01-01T23:59:59.000Z

439

EFFECTS OF NOISE ON SEALS AND SEA LIONS: LABORATORY APPROACHES  

E-Print Network (OSTI)

169 EFFECTS OF NOISE ON SEALS AND SEA LIONS: LABORATORY APPROACHES DAVID KASTAK Long Marine, and the evolutionary hiology of marine carnivores in general. Newer, more rapid technologies and psychophysical pinniped subjects reside at Long Marine Laboratory at the University of California, Santa Cruz, where

Reichmuth, Colleen

440

Brady 1D seismic velocity model ambient noise prelim  

SciTech Connect

Preliminary 1D seismic velocity model derived from ambient noise correlation. 28 Green's functions filtered between 4-10 Hz for Vp, Vs, and Qs were calculated. 1D model estimated for each path. The final model is a median of the individual models. Resolution is best for the top 1 km. Poorly constrained with increasing depth.

Robert J. Mellors

2013-10-25T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Six?year study of IMSA road racing noise  

Science Journals Connector (OSTI)

The Del Mar Fairgrounds San Diego hosted the IMSA Grand Prix for 6 years from 1987–1993. The project provides a unique long?term study of professional road racing noise in a unique setting a narrow valley just east of the coastline and within an environmentally sensitive lagoon. Sponsors were required to perform community noise monitoring at selected locations in the adjacent hills and lagoon. Both human and bird responses were examined. The monitoring documented the hour by hour variations in the maximum and average noise levels at up to 12 separate locations. The results indicated the thresholds which would trigger community response the sensitivity of the response to diurnal and short?term wind shift the effect of the inversion layer the effects on bird patterns and the statistical distribution of vehicle noise levels for the IMSA class vehicle. Basic findings revealed community response was triggered when levels exceeded 70 dBA Lavg. Downwind levels tended to increase at 1 dBA/mph over 5 mph. When the track was within an inversion levels increased 10 dBA. The mean vehicle level at 15 m was 105 dBA with a 4?dBA standard deviation.

Gordon Bricken; Christopher Jean

1997-01-01T23:59:59.000Z

442

Raw Data Compression in Computed Tomography: Noise Shaping  

E-Print Network (OSTI)

Raw Data Compression in Computed Tomography: Noise Shaping Yao Xie (team member: Adam Wang) Project.1 Background X-ray computed tomography (CT) builds on the physical principles of radiography. It uses multiple ring that has a limited data transfer rate. Compression can be used to reduce the data rate through

Xie, Yao

443

Johnson Noise and the Boltzmann Constant 1 Introduction  

E-Print Network (OSTI)

with high-gain. References: · Melissinos and Napolitano, Section 3.6 (p. 122 forward). · Elementary across the conductor that depends on temperature. That is, there is electrical noise associated divided by resistance. Then the root-mean-square (rms) voltage across the resistor is d V 2 = 4k

Mahapatra, Rupak

444

Stochastic DAEs in Transient Noise Simulation Renate Winkler  

E-Print Network (OSTI)

resistor having a resistance R, maintained in thermal equilibrium at a temperature T , can be described to the elementary charge, is also modelled by a Gaussian white noise process, where the spectral density is proportional to the current I through the pn- junction: S shot := qjI j , where q is the elementary charge

Römisch, Werner

445

Stochastic Differential Algebraic Equations in Transient Noise Analysis  

E-Print Network (OSTI)

a resistance R, maintained in ther- mal equilibrium at a temperature T, can be described as the sum of the de by the discrete nature of current due to the elementary charge, is also modelled by a Gaussian white noise process|I|, where q is the elementary charge. If the current through the pn- junction is described

Römisch, Werner

446

Primary Electronic Thermometry Using the Shot Noise of a Tunnel  

E-Print Network (OSTI)

. Lehnert,1,2 I. Siddiqi,1 R. J. Schoelkopf1 We present a thermometer based on the electrical noise from a tunnel junction. In this thermometer, temperature is related to the voltage across the junction thermometer over four orders of magnitude in temperature, with as high as 0.1% accuracy and 0.02% precision

447

Enhancement and suppression of heat transfer by MHD turbulence  

E-Print Network (OSTI)

We study of the effect of turbulence on heat transfer within magnetized plasmas for energy injection velocities both larger and smaller that the Alfven speed. We find that in the latter regime the heat transfer is partially suppressed, while in the former regime the effects of turbulence depend on the intensity of driving. In fact, the scale l at which the turbulent velocity is equal the Alfven velocity is a new important parameter. When the electron mean free path is larger than l, the stronger the the turbulence, the lower thermal conductivity by electrons is. The turbulent motions, however, induces their own advective heat transport, which, for the parameters of intracluster medium (ICM) provides effective heat diffusivity that exceeds the classical Spitzer value.

A. Lazarian

2006-08-02T23:59:59.000Z

448

Novel technique of suppressing TBBU in high-energy ERLs  

SciTech Connect

Energy recovery linacs (ERLs) are an emerging generation of accelerators that promise to revolutionize the fields of high-energy physics and photon sciences. These accelerators combine the advantages of linear accelerators with that of storage rings, and augur the delivery of electron beams of unprecedented power and quality. However, one potential weakness of these devices is transverse beam break-up instability that could severely limit the available beam current. In this paper, I propose a novel method of suppressing these dangerous effects using the chromaticity of the transverse motion. In this short paper I am able only to touch the surface of the method and a complete description of the method with all relevant derivations can be found in [1].

Litvinenko V.

2012-05-20T23:59:59.000Z

449

E-Print Network 3.0 - acid suppresses uv-b-induced Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

are discussed in relation to the Summary: in Chapter 3, carboxylic acids are the actual additives responsible for the suppression of catalase... excess of carboxylic acid in...

450

E-Print Network 3.0 - acid suppression trial Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

suppression index for ... Source: Curran, Tim - Department of Psychology, University of Colorado at Boulder Collection: Biology and Medicine 40 DEAFFERENTATION AFFECTS SHORT-TERM...

451

E-Print Network 3.0 - amphetamine-mediated appetite suppression...  

NLE Websites -- All DOE Office Websites (Extended Search)

from motivated appetitive behavior. An incentive attribution hypothesisthat can... " (Stricker & Zigmond, 1986, p. 689). The same suppression of response activation may apply even...

452

Cryogenic Optomechanics with a Si3N4 Membrane and Classical Laser Noise  

E-Print Network (OSTI)

We demonstrate a cryogenic optomechanical system comprising a flexible Si3N4 membrane placed at the center of a free-space optical cavity in a 400 mK cryogenic environment. We observe a mechanical quality factor Q > 4 x 10^6 for the 261-kHz fundamental drum-head mode of the membrane, and a cavity resonance halfwidth of 60 kHz. The optomechanical system therefore operates in the resolved sideband limit. We monitor the membrane's thermal motion using a heterodyne optical circuit capable of simultaneously measuring both of the mechanical sidebands, and find that the observed optical spring and damping quantitatively agree with theory. The mechanical sidebands exhibit a Fano lineshape, and to explain this we develop a theory describing heterodyne measurements in the presence of correlated classical laser noise. Finally, we discuss the use of a passive filter cavity to remove classical laser noise, and consider the future requirements for laser cooling this relatively large and low-frequency mechanical element to very near its quantum mechanical ground state.

A. M. Jayich; J. C. Sankey; K. Borkje; D. Lee; C. Yang; M. Underwood; L. Childress; A. Petrenko; S. M. Girvin; J. G. E. Harris

2012-09-12T23:59:59.000Z

453

Optical scattering noise in high Q fiber ring resonators and its effect on optoelectronic oscillator phase noise  

E-Print Network (OSTI)

Optical scattering noise in high Q fiber ring resonators and its effect on optoelectronic is used as the frequency reference device in an optoelectronic oscillator (OEO), it has been found using optical delay lines and the optoelectronic oscillator (OEO) approach [1]. Although delay line

Paris-Sud XI, Université de

454

Experimental design to determine the effect of temperature and Mach number on entropy noise  

E-Print Network (OSTI)

The Osney Laboratory sought to create an entropy noise test rig that could determine the relationship between entropy noise and the flow parameters of temperature change and nozzle Mach number. The apparatus simulates ...

Hake, Mariah I. (Mariah Inez)

2014-01-01T23:59:59.000Z

455

Noise Reduction of Centrifugal Compressors using Array of Quarter Wavelength Resonators  

E-Print Network (OSTI)

Noise radiated from high speed centrifugal compressors is becoming a significant design factor. The dominant noise components of a centrifugal compressor can be identified at its blade passing frequencies (BPFs), of which each is a strong tonal...

Ye, Nan

2014-07-31T23:59:59.000Z

456

Signal-to-noise ratio: Computed Dental Radiography versus Sens-A-Ray  

Science Journals Connector (OSTI)

The signal-to-noise ratio (SNR) describes the ability of a detector to differentiate a signal from random fluctuations in signal intensity or noise in an image. The dose-response curves and the SNRs were measu...

Yoshihiko Hayakawa Ph.D.; Allan G. Farman BDS; Ph.D.Sc.…

1995-12-01T23:59:59.000Z

457

H.A.R. 11-46 - Community Noise Control | Open Energy Information  

Open Energy Info (EERE)

H.A.R. 11-46 - Community Noise ControlLegal Abstract The Hawaii State Department of Health regulates community noise through this chapter of the administrative rules. Published...

458

Performance analysis of the Maximum Likelihood detector for nominally Laplace noise  

E-Print Network (OSTI)

In this thesis, we consider the problem of detecting an identified signal corrupted by Laplace noise. The noise is zero mean, additive and independent and identically distributed, with imperfectly known standard deviation. We have compared...

Valangiman Raman, Sathya Narayanan

2012-06-07T23:59:59.000Z

459

Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine  

E-Print Network (OSTI)

of Reduced Noise Operations of Wind Turbines on Neighborof Reduced Noise Operations of Wind Turbines on NeighborWind Speed (m/s) 3 Turbines (in operation at the time) Noise

Hoen, Ben

2010-01-01T23:59:59.000Z

460

Displacement-noise-free resonant speed meter for gravitational-wave detection  

E-Print Network (OSTI)

We demonstrate that speedmeter, based on double pumped resonant Sagnac interferometer, can be used as a displacement noise free gravitational-wave (GW) detector. The displacement noise of cavity mirrors can be completely excluded through a proper linear combination of the output signals. We show that in low-frequency region the obtained displacement-noise-free response signal is stronger than the one in previously proposed displacement noise free interferometers.

Sergey P. Vyatchanin

2008-08-26T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

An experimental study of low-frequency amplitude noise in a fibre Bragg grating laser diode  

SciTech Connect

We have studied the amplitude noise in a fibre Bragg grating laser diode. It has been shown that discontinuities in noise characteristics correlate with those in the power – current and spectral characteristics of the laser diode, whereas the noise characteristics of the pump source have no such discontinuities. The highest noise level has been observed at pump currents corresponding to concurrent generation of two longitudinal modes. (lasers)

Zholnerov, V S [Russian Institute of Radionavigation and Time, St.Petersburg (Russian Federation); Ivanov, A V; Kurnosov, V D; Kurnosov, K V; Romantsevich, V I; Chernov, R V [Open Joint-Stock Company M.F. Stel'makh Polyus Research Institute, Moscow (Russian Federation)

2013-09-30T23:59:59.000Z

462

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

E-Print Network (OSTI)

Neutron noise calculations using the Analytical Nodal Method and comparisons with analytical Available online 28 December 2010 Keywords: Neutron noise ANM Power reactor approximation 2-Group theory Diffusion theory a b s t r a c t In this study, the neutron noise, i.e. the stationary fluctuations

Demazière, Christophe

463

An Efficient Operator-Splitting Method for Noise Removal in Images  

E-Print Network (OSTI)

, removal of additive, zero-mean noise in digital images is investigated. We use the ideas proposed in [1An Efficient Operator-Splitting Method for Noise Removal in Images D. KRISHNAN , P. LIN and X. C. TAI Abstract In this work, noise removal in digital images is investigated. The importance

Soatto, Stefano

464

Applied Acoustics 63 (2002), 1109-1124 Noise assessment in a high-speed train  

E-Print Network (OSTI)

Applied Acoustics 63 (2002), 1109-1124 1 Noise assessment in a high-speed train Etienne PARIZET recordings in various positions in a high-speed train have been used as stimuli in listening tests to noise outside train or inside cars, the perception of noise in trains has not been studied intensively

Paris-Sud XI, Université de

465

Asymmetric noise probed with a Josephson junction Q. Le Masne,1  

E-Print Network (OSTI)

Asymmetric noise probed with a Josephson junction Q. Le Masne,1 H. Pothier,1, Norman O. Birge,2 C are measured using a Josephson junction. The current noise adds to the bias current of the Josephson junction], consists in using a Josephson junction (JJ) as a large bandwidth on-chip noise detector [7, 8, 9]. It has

Boyer, Edmond

466

Size-dependent physiological responses of shore crabs to single and repeated playback of ship noise  

Science Journals Connector (OSTI)

...increase in response to ship-noise playback...predicted that the effect might be size-dependent...six (ambient and ship noise from each of...potential carry-over effects. In the repeated-exposure...and F Ladich. 2007 Effects of ship noise on the detectability...

2013-01-01T23:59:59.000Z

467

Photodiode nonlinear modeling and its impact on optical links phase noise  

E-Print Network (OSTI)

Photodiode nonlinear modeling and its impact on optical links phase noise Z. Abdallah1,4 , A R&T, Palaiseau, France 4 CNES, Toulouse, France Abstract--The photodiode impact on the phase noise, and the link gain and phase noise performance are computed. Keywords--photodiode; nonlinear modelling; CAD

Paris-Sud XI, Université de

468

IMPROVED MMSE-BASED NOISE PSD TRACKING USING TEMPORAL CEPSTRUM Timo Gerkmann  

E-Print Network (OSTI)

, The Netherlands r.c.hendriks@tudelft.nl ABSTRACT Recently, it has been shown that MMSE-based noise power estima-based approaches. The MMSE-based approach employs two estimates of the speech power to estimate the unbiased noise power. In this work, we improve the MMSE-based noise power estimator by employing a more advanced

469

Waves Transmission and Generation in Turbine Stages in a Combustion-Noise Framework  

E-Print Network (OSTI)

, the acoustic behavior of the turbine blade rows must be known to evaluate the noise due to combustionWaves Transmission and Generation in Turbine Stages in a Combustion-Noise Framework M. Leyko SNECMA-engines could have two different origins: (a) the well-known direct combustion noise,2 which is directly

Nicoud, Franck

470

SYNTHESIS How and why environmental noise impacts animals: an integrative, mechanistic review  

E-Print Network (OSTI)

of natural noise and are predicted to have an array of deleterious effects on wildlife. Recent work of noise, including wind, water and other animals, one increasingly influential source is anthropogenic research focused on the effects of any environmental noise on wildlife, whether it is anthropogenic

Swaddle, John

471

Numerical simulation of turbulence interaction noise applied to a serrated airfoil  

E-Print Network (OSTI)

Numerical simulation of turbulence interaction noise applied to a serrated airfoil Vincent CLAIR, Gabriel Reboul, Thomas Le Garrec. Numerical simulation of turbulence interaction noise applied, des laboratoires publics ou priv´es. #12;Numerical simulation of turbulence interaction noise applied

472

Automatic noise estimation in images using local statistics. Additive and multiplicative cases  

Science Journals Connector (OSTI)

In this paper, we focus on the problem of automatic noise parameter estimation for additive and multiplicative models and propose a simple and novel method to this end. Specifically we show that if the image to work with has a sufficiently great amount ... Keywords: Gaussian noise, Local statistics, Mode, Noise estimation, Restoration

Santiago Aja-Fernández; Gonzalo Vegas-Sánchez-Ferrero; Marcos Martín-Fernández; Carlos Alberola-López

2009-05-01T23:59:59.000Z

473

Selection of Electrode Area for Electrochemical Noise Measurements to Monitor Localized CO2 Corrosion  

E-Print Network (OSTI)

1 Selection of Electrode Area for Electrochemical Noise Measurements to Monitor Localized CO2-saturated 1 wt % NaCl solution at 80o C. Electrochemical noise (EN) was obtained from both 11.6 cm2 and 1 cm, electrochemical noise, electrode size, pitting, transient INTRODUCTION CO2 corrosion of steel pipelines has been

Paris-Sud XI, Université de

474

Noise pollution: A threat to our mental and physical well?being  

Science Journals Connector (OSTI)

While noise may not yet be in the forefront of the environmental movement it is being recognized worldwide as a major environmental pollutant. In New York City noise is the number one quality of life complaint far outweighing other quality of life complaints and throughout the United States it has been noted as a major reason for people moving from their homes. Although there is a need for additional research to confirm the health/noise link the World Health Organization has already recognized noise pollution as a serious health issue. There is certainly sufficient research to warrant warnings that noise is injurious to mental and physical health. Yet despite this growing body of literature attesting to the relationship between noise and health impacts government bodies have not yet invested the dollars needed to abate noise nor to educate people to the dangers of noise. Organizations such as the League for the Hard of Hearing the Noise Pollution Clearinghouse and the United Kingdom Noise Network have assumed the tasks of educating the public to the harmful effects of noise of advocating anti?noise measures and of urging public officials to move more assertively in lessening the din of our ever?increasing noisy society.

2004-01-01T23:59:59.000Z

475

A Cardiac Electro-physiological Model Based Approach for Filtering High Frequency ECG Noise  

E-Print Network (OSTI)

A Cardiac Electro-physiological Model Based Approach for Filtering High Frequency ECG Noise MA on automatic diagnoses of cardiac disease through ECG signals, de-noising tech- niques that do not introduce noise from ECG signals. The proposed modeling technique is based on the propagation of the electric

Povinelli, Richard J.

476

Extremal shot noises, heavy tails and max-stable random fields.  

E-Print Network (OSTI)

Extremal shot noises, heavy tails and max-stable random fields. Cl´ement Dombry May 31, 2010 Abstract We consider the extremal shot noise defined by M(y) = sup{mh(y - x); (x, m) }, where. Extremal shot noises naturally appear in extreme value theory as a model for spatial extremes and serve

Paris-Sud XI, Université de

477

Kalispel Non-Native Fish Suppression Project 2007 Annual Report.  

SciTech Connect

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.

Wingert, Michele; Andersen, Todd [Kalispel Natural Resource Department

2008-11-18T23:59:59.000Z

478

Abstract 1079: COX-2 blockade immunologically suppresses brain metastasis of lung cancer  

Science Journals Connector (OSTI)

...COX-2 blockade immunologically suppresses brain metastasis of lung cancer Mitsugu Fujita...hypothesized that COX-2 blockade would suppress brain metastasis of cancers by inhibiting MDSC...microenvironment (TME). In both mouse and human brain metastasis cases, the expression levels...

Mitsugu Fujita; Susumu Nakata; Takeshi Okuda; Amami Kato; Osamu Yoshie

2014-10-01T23:59:59.000Z

479

Tamoxifen Suppresses Tumor Promoter-induced Hydrogen Peroxide Formation by Human Neutrophils  

Science Journals Connector (OSTI)

...totally inhibits hydrogen peroxide (IM...TAM suppresses hydrogen per oxide (H2O2...results in H2O2 production (16), which...MATERIALS AND METHODS Reagents. TAM...TAMOXIFEN SUPPRESSES HYDROGEN PEROXIDE INDUCTION...increase of H2O2 production by 25 nin TPA-stimulated...Materials and Methods." ( "),TPA...

Jong Shiaw Lim; Krystyna Frenkel; and Walter Troll

1992-09-15T23:59:59.000Z

480

Active vibration suppression of a exible structure using smart material and a modular control patch  

E-Print Network (OSTI)

Active vibration suppression of a ¯exible structure using smart material and a modular control of vibration suppression of a ¯exible structure using smart materials and a miniaturized digital controller and was developed by TRW for the United States Air Force for future space vibration control. In this research

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481

Fabrication and Optimal Strain Sensor Placement in an Instrumented Disk Drive Suspension for Vibration Suppression  

E-Print Network (OSTI)

for Vibration Suppression Kenn Oldham, Stanley Kon Computer Mechanics Laboratory (CML) University of California drive suspension with vibra- tion sensing strain gages can enhance vibration suppression in hard disk bits. As the industry targets bit densities of 1 terabit per square inch, airflow induced vibration

Horowitz, Roberto

482

A nested invocation suppression mechanism for active replication fault-tolerant CORBA  

E-Print Network (OSTI)

1 A nested invocation suppression mechanism for active replication fault-tolerant CORBA Deron Liang. The redundant nested invocation (RNI) problem arises when servers in a replicated group issues nested a mechanism to perform auto-suppression of redundant nested invocation in an active replication fault

Chen, Sheng-Wei

483

On the use of shot noise for photon counting  

E-Print Network (OSTI)

Lieu et al. (2015) have recently claimed that it is possible to substantially improve the sensitivity of radio astronomical observations. In essence, their proposal is to make use of the intensity of the photon shot noise as a measure of the photon arrival rate. Lieu et al. (2015) provide a detailed quantum-mechanical calculation of a proposed measurement scheme that uses two detectors and conclude that this scheme avoids the sensitivity degradation that is associated with photon bunching. If correct, this result could have a profound impact on radio astronomy. Here I present a detailed analysis of the sensitivity attainable using shot-noise measurement schemes that use either one or two detectors, and demonstrate that neither scheme can avoid the photon bunching penalty. I perform both semiclassical and fully quantum calculations of the sensitivity, obtaining consistent results, and provide a formal proof of the equivalence of these two approaches. These direct calculations are furthermore shown to be consis...

Zmuidzinas, Jonas

2015-01-01T23:59:59.000Z

484

Making tensor factorizations robust to non-gaussian noise.  

SciTech Connect

Tensors are multi-way arrays, and the CANDECOMP/PARAFAC (CP) tensor factorization has found application in many different domains. The CP model is typically fit using a least squares objective function, which is a maximum likelihood estimate under the assumption of independent and identically distributed (i.i.d.) Gaussian noise. We demonstrate that this loss function can be highly sensitive to non-Gaussian noise. Therefore, we propose a loss function based on the 1-norm because it can accommodate both Gaussian and grossly non-Gaussian perturbations. We also present an alternating majorization-minimization (MM) algorithm for fitting a CP model using our proposed loss function (CPAL1) and compare its performance to the workhorse algorithm for fitting CP models, CP alternating least squares (CPALS).

Chi, Eric C. (Rice University, Houston, TX); Kolda, Tamara Gibson

2011-03-01T23:59:59.000Z

485

1f Noise of Granular Metal-Insulator Composites  

Science Journals Connector (OSTI)

The resistivity ? varies by 7 decades and the intensity of its fluctuations [S?(f)]1Hz varies by 17 decades in composite films of Pt and Al2O3 for a wide range of metal volume percent 33%<~p<~100% and temperature 7noise) with 0.8noise intensity [fS?(f)?2]1Hz rises by 105 with decreasing p and saturates below a metal-insulator transition, p<~50%. Results implicate a dual conduction mechanism for composites combining noisy tunneling and quiet metallic paths.

Joseph V. Mantese and Watt W. Webb

1985-11-11T23:59:59.000Z

486

Signal/noise optimization strategies for stochastically estimated correlation functions  

E-Print Network (OSTI)

Numerical studies of quantum field theories usually rely upon an accurate determination of stochastically estimated correlation functions in order to extract information about the spectrum of the theory and matrix elements of operators. The reliable determination of such correlators is often hampered by an exponential degradation of signal/noise at late time separations. We demonstrate that it is sometimes possible to achieve significant enhancements of signal/noise by appropriately optimizing correlators with respect to the source and sink interpolating operators, and highlight the large range of possibilities that are available for this task. The ideas are discussed for both a toy model, and single hadron correlators in the context of quantum chromodynamics.

William Detmold; Michael G. Endres

2014-09-19T23:59:59.000Z

487

Three-dimensional anisotropic adaptive filtering of projection data for noise reduction in cone beam CT  

SciTech Connect

Purpose: The combination of quickly rotating C-arm gantry with digital flat panel has enabled the acquisition of three-dimensional data (3D) in the interventional suite. However, image quality is still somewhat limited since the hardware has not been optimized for CT imaging. Adaptive anisotropic filtering has the ability to improve image quality by reducing the noise level and therewith the radiation dose without introducing noticeable blurring. By applying the filtering prior to 3D reconstruction, noise-induced streak artifacts are reduced as compared to processing in the image domain. Methods: 3D anisotropic adaptive filtering was used to process an ensemble of 2D x-ray views acquired along a circular trajectory around an object. After arranging the input data into a 3D space (2D projections + angle), the orientation of structures was estimated using a set of differently oriented filters. The resulting tensor representation of local orientation was utilized to control the anisotropic filtering. Low-pass filtering is applied only along structures to maintain high spatial frequency components perpendicular to these. The evaluation of the proposed algorithm includes numerical simulations, phantom experiments, and in-vivo data which were acquired using an AXIOM Artis dTA C-arm system (Siemens AG, Healthcare Sector, Forchheim, Germany). Spatial resolution and noise levels were compared with and without adaptive filtering. A human observer study was carried out to evaluate low-contrast detectability. Results: The adaptive anisotropic filtering algorithm was found to significantly improve low-contrast detectability by reducing the noise level by half (reduction of the standard deviation in certain areas from 74 to 30 HU). Virtually no degradation of high contrast spatial resolution was observed in the modulation transfer function (MTF) analysis. Although the algorithm is computationally intensive, hardware acceleration using Nvidia's CUDA Interface provided an 8.9-fold speed-up of the processing (from 1336 to 150 s). Conclusions: Adaptive anisotropic filtering has the potential to substantially improve image quality and/or reduce the radiation dose required for obtaining 3D image data using cone beam CT.

Maier, Andreas; Wigstroem, Lars; Hofmann, Hannes G.; Hornegger, Joachim; Zhu Lei; Strobel, Norbert; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Radiology, Stanford University, Stanford, California 94305 (United States) and Center for Medical Image Science and Visualization, Linkoeping University, Linkoeping (Sweden); Pattern Recognition Laboratory, Department of Computer Science, Friedrich-Alexander University of Erlangen-Nuremberg, 91054, Erlangen (Germany); Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Siemens AG Healthcare, Forchheim 91301 (Germany); Department of Radiology, Stanford University, Stanford, California 94305 (United States)

2011-11-15T23:59:59.000Z

488

Asymptotically robust detection of stochastic signals in contaminated noise  

E-Print Network (OSTI)

OF SCIENCE August 1986 Major Subject: Electrical Engineering ASYMPTOTICALLY ROBUST DETECTION OF STOCHASTIC SIGNALS LN CONTAMINATED NOISE A Thesis by MARK STEVEN SCHiVITZER Approved as to style and content by: i&, . D. R. Halverson (Committee... Department, for his help in generating the computer software and preparing the tables. To the Department of Electrical Engineering and the College of Medicine at Texas A&M University for allowing me to design a combined M. S. /M. D. degree program. To my...

Schnitzer, Mark Steven

2012-06-07T23:59:59.000Z

489

A White Noise Approach to Phase Space Feynman Path Integrals  

E-Print Network (OSTI)

The concepts of phase space Feynman integrals in White Noise Analysis are established. As an example the harmonic oscillator is treated. The approach perfectly reproduces the right physics. I.e., solutions to the Schr\\"odinger equation are obtained and the canonical commutation relations are satisfied. The later can be shown, since we not only construct the integral but rather the Feynman integrand and the corresponding generating functional.

Wolfgang Bock; Martin Grothaus

2010-12-06T23:59:59.000Z

490

Efficient Transient Noise Analysis in Circuit Georg Denk1  

E-Print Network (OSTI)

. Winkler pn-junctions, caused by the discrete nature of currents due to the elementary charge, is modelled the resistance, T is the temperature, k = 1.38 · 10-23 is Boltzmann's constant, idet(u) is the characteristic of the noise-free current through the pn-junction and qe = 1.60 · 10-19 is the elementary charge. Combining

Römisch, Werner

491

Trailing edge noise mitigation investigation for wind turbine blades  

Science Journals Connector (OSTI)

Wind turbines offer one of the most mature technologies for providing large scale renewable energy to society in an economically viable way. Although not on par with the price of conventional energy sources yet the cost of energy has been steadily decreasing as the technology continues to develop. Unfortunately like with all energy sources there are some problems with this form of generation. Among these sound emissions from wind turbines are one of the problems people who live close to the installed machines may be exposed to. Past studies show that these noise emissions are dominated by aeroacousticnoise and of the many mechanisms that lead to aeroacousticnoise the interaction between the unsteady flow and the trailing edge seems to constitute the largest portion of the overall sound spectrum. Modifications to the trailing edge geometry will change how the fluid interacts with the trailing edge and can be used to change the resulting noise emission. This study will investigate the effect passive trailing edge devices have on the overall noise emission from a wind turbine in an attempt to reduce the aeroacousticnoise being generated by the turbine.

Michael J. Asheim; Dave Munoz; Patrick Moriarty

2012-01-01T23:59:59.000Z

492

Noise in non?premixed turbulent syngas flames  

Science Journals Connector (OSTI)

A turbulent syngas flame may generate acoustic noise of high acoustic intensity in a combustion chamber. This may lead to the failure of construction components in a gas turbine engine in periods of the order of 1–100 hours. The research as described in the literature has almost exclusively been performed on the generation of noise in premixed methane or propane flames. Syngas fuel is a mixture of hydrogen and carbon monoxide and the burners used are of the non?premixed type. In this research the effect of turbulence and syngas composition on noise generation is investigated. A laboratory is set up to test syngas flames of a thermal power of 50 kW in a cylindrical air?cooled combustion chamber. Experiments are performed at several fuel compositions and burner inlet conditions. The flame sound intensity is measured in the combustion chamber equipped with acoustic dampers. The paper discusses the measured sound spectra. A model is derived for the generation of sound in a turbulent non?premixed flame. In this model it is shown that the sound generation is related to the dependence of density on mixture fraction in a flame with fast chemistry. A fluctuation in mixture fraction will lead to sound generation.

Sikke A. Klein; Jim B. W. Kok

1998-01-01T23:59:59.000Z