Powered by Deep Web Technologies
Note: This page contains sample records for the topic "acoustic doppler current" 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

Measuring surface ocean wave height and directional spectra using an Acoustic Doppler Current Profiler from an autonomous underwater vehicle  

E-Print Network [OSTI]

The Acoustic Doppler Current Profiler (ADCP) is a proven technology which is capable of measuring surface wave height and directional information, however it is generally limited to rigid, bottom mounted applications which ...

Haven, Scott

2012-01-01T23:59:59.000Z

2

Study on acoustics for SSC measurements Using the acoustic Doppler current profiler (ADCP) to  

E-Print Network [OSTI]

................................................................................................................................. 1 2. Background of higher- frequency, acoustic backscatterance sensors (ABS, for a review see Thorne and Hanes, 2002), and optical backscatterance sensors (OBS), whose sample ranges ar

Voulgaris, George

3

Acoustic Doppler current profiling from the JGOFS Arabian Sea cruises aboard the RV T.G. Thompson  

SciTech Connect (OSTI)

Acoustic Doppler current profiler (ADCP) data is part of the core data for the US JGOFS Arabian Sea project, along with hydrographic and nutrient data. Seventeen cruises are scheduled to take place between September 1994 and January 1996 on the R/V T.G. Thompson. Seven of the cruises follow a standard cruise track, taking hydrographic, chemical and biological measurements. The rest of the cruises, which take place generally within the standard cruise region defined by a set track, are for the deployment and recovery of moored equipment and towing of a SeaSoar. Detailed description of ADCP hardware, the AutoADCP data acquisition system, and the collection of navigation and compass data on the Thompson is documented in Section 2. Followed by data collection for each cruise together with a cruise track, Section 3 presents the processing and analysis of velocity and acoustic backscatter intensity data. Section 5 shows results of profile quality diagnosis.

Kim, H.S.; Flagg, C.N.; Shi, Y. [Brookhaven National Lab., Upton, NY (United States). Oceanographic and Atmospheric Sciences Div.

1996-12-01T23:59:59.000Z

4

Characterizing Ocean Turbulence from Argo, Acoustic Doppler, and Simulation Data  

E-Print Network [OSTI]

. TurbSim models statistics at the height of a turbine hub (5m) well, but do not model coherent eventsCharacterizing Ocean Turbulence from Argo, Acoustic Doppler, and Simulation Data Katherine Mc Ocean Turbulence from Argo, Acoustic Doppler, and Simulation Data written by Katherine McCaffrey has

Fox-Kemper, Baylor

5

E-Print Network 3.0 - acoustic doppler velocimeter Sample Search...  

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

of Hawai'i at Manoa Collection: Engineering 7 Quantifying Turbulence for Tidal Power Applications Summary: against Acoustic Doppler Velocimeter (ADV) data at a point....

6

Aircraft tracking by means of the Acoustical Doppler Effect  

Science Journals Connector (OSTI)

The present paper presents a passive acoustic method for aircraft tracking. The Acoustical Doppler Effect, characteristic of signals received by a mesh of spatially distributed microphones is the basis of the method. A one-dimensional version of the Ambiguity function permits the calculation of the frequency stretch factor that exists between the sound signals received by a pair of microphones. The expression for this frequency stretch is a function of the aircraft position and velocity which are estimated by a Genetic Algorithm. The method is suitable for all kinds of aircraft and requires only seven microphones plus the prior knowledge of only the aircraft position and velocity at a given time. Results are given for a simulation test of a 3D straight trajectory of the aircraft and for a sound-propagation model which considers geometrical spreading and atmospheric absorption of sound for a homogeneous medium. The influence of the atmospheric absorption is evaluated and the independence of the method with respect to microphone distribution is proven. The performance of the tracking method has also been evaluated in front of possible inaccuracy on the microphones synchronization.

Sara R. Martín; Meritxell Genescà; Jordi Romeu; Teresa Pàmies

2013-01-01T23:59:59.000Z

7

Low complexity multipath and Doppler-shift correction algorithm for reliable underwater Coherent-FSK acoustic modems: short paper  

Science Journals Connector (OSTI)

This paper presents an innovative algorithm for Doppler-shift and multipath correction in a coherent-FSK modem, which is optimized for acoustic communications in shallow water underwater networks. The final modem will be used in the ANDREA project, whose ... Keywords: Doppler-shift, acoustic modem, multipath correction, underwater networks, wireless sensor networks

A. Sanchez; S. Climent; P. Yuste; A. Perles-Ivars; J. J. Serrano

2012-11-01T23:59:59.000Z

8

Doppler effects in heterogeneous media with applications to ocean acoustic modeling  

Science Journals Connector (OSTI)

Doppler shift corrections to ocean acoustic signals are complicated by the multi-spatial-scale structure of the ocean medium, resulting in a multi-time-scale structure of the acoustic Green function. Repeated reflections and refractions lead in general to an infinite number of acoustic paths or modes, with different times of flight, connecting source and receiver. The rate of change of these flight times with source or receiver motion gives rise to Doppler shift corrections, and each acoustic path or mode has a different correction. A clean Doppler correction (in the sense of an observable coherent motion-induced frequency shift for each path or mode) is shown to emerge only when the medium is homogeneous along the direction of source or receiver motion, even when it is highly inhomogeneous in directions orthogonal to the motion. A very general quantitative theory for this correction is developed, encompassing earlier results in the literature, and presented in a form amenable to efficient numerical implementation in data processing.

Peter B. Weichman

2005-12-06T23:59:59.000Z

9

Noninvasive Monitoring of Vocal Fold Vertical Vibration Using The Acoustic Doppler Effect  

Science Journals Connector (OSTI)

SummaryObjectives/Hypothesis To validate a proposed method of noninvasively monitoring vocal fold vertical vibration through utilization of the acoustic Doppler effect and the waveguide property of the vocal tract. Study Design Validation case-control study. Methods In this device, an ultrasound beam is generated and directed into the mouth. The vocal tract, acting as a natural waveguide, guides the ultrasound beam toward the vibrating vocal folds. The vertical velocity of vocal fold vibration is then recovered from the Doppler frequency of the reflected ultrasound. One subject (age 32, male) was studied and measurements were taken under three modes of vocal fold vibration: breathing (no vibration), whispering (irregular vibration), and normal phonation (regular vibration). Results The peak-to-peak amplitude of the measured velocity of vocal fold vertical vibration was about 0.16 m/s, and the fundamental frequency was 172 Hz; the extracted velocity information showed a reasonable waveform and value in comparison with the previous studies. In all three modes of phonation, the Doppler frequencies derived from the reflected ultrasound corresponded with the vertical velocity of vocal fold vibration as expected. Conclusions The proposed method can accurately represent the characteristics of different phonation modes such as no phonation, whisper and normal phonation. The proposed device could be used in daily monitoring and assessment of vocal function and vocal fold vibration.

Chao Tao; Jack J. Jiang; Dan Wu; Xiaojun Liu; Ann Chodara

2012-01-01T23:59:59.000Z

10

Measuring the Kuroshio Current with ocean acoustic tomography Naokazu Taniguchia)  

E-Print Network [OSTI]

Measuring the Kuroshio Current with ocean acoustic tomography Naokazu Taniguchia) Graduate School 29 April 2013) Ocean current profiling using ocean acoustic tomography (OAT) was conducted proportional to temperature) and current in the ocean (Munk et al., 1995). Other than coastal sea studies (e

Frandsen, Jannette B.

11

Doppler effect reduction based on time-domain interpolation resampling for wayside acoustic defective bearing detector system  

Science Journals Connector (OSTI)

Abstract In the wayside Acoustic Defective Bearing Detector (ADBD) system, the recorded acoustic signal will be severely distorted by the Doppler effect because of the high moving speed of the railway vehicle, which is a barrier that would badly reduce the effectiveness of online defect detection. This paper proposes a simple and effective method, called time-domain interpolation resampling (TIR), to remove the Doppler effect embedded in the acoustic signal. The TIR is conducted in three steps. First, the time vector for resampling is calculated according to the kinematic analysis. Second, the amplitude of the distorted signal is demodulated. Third, the distorted signal is re-sampled using spline interpolation. In this method, both the spectrum structure and the amplitudes of the distorted signal can be restored. The effectiveness of TIR is verified by means of simulation studies and train roller bearing experiments with various types of defects. It is also compared to an existing Doppler effect reduction method that is based on the instantaneous frequency estimation using Hilbert transform. Results indicate that the proposed TIR method has the superior performance in removing the Doppler effect, and can be well implemented to Doppler effect reduction for the ADBD system.

Fang Liu; Qingbo He; Fanrang Kong; Yongbin Liu

2014-01-01T23:59:59.000Z

12

Mooring Motion Bias of Point-Doppler Current Meter Measurements Paul Freitag, Michael McPhaden, Chris Meinig, Patricia Plimpton  

E-Print Network [OSTI]

Mooring Motion Bias of Point-Doppler Current Meter Measurements Paul Freitag, Michael Mc). Until 1998 the moorings were instrumented with mechanical current meters (MCMs, either Vector Averaging Current Meters (VACM) or Vector Measuring Current Meters (VMCM)). Comparison with nearby subsurface 150 k

13

Chapter 7 - Horizontally Integrated Remote Measurements of Ocean Currents Using Acoustic Tomography Techniques  

Science Journals Connector (OSTI)

Abstract This chapter begins with a discussion of the comparative difficulty of measuring horizontally integrated subsurface oceanic current and vorticity measurements. This is followed by a discussion of computer-assisted tomography techniques used in the medical, geophysical, and seismic branches of science and their adaptation and extension to acoustic tomography for subsurface oceanographic investigations. In particular, the following aspects pertaining to the application of acoustic methods for probing the oceans’ interior water temperature and current structure, as well as their adaptations for measuring horizontally averaged water currents from straits, coastal water bodies, estuaries, and rivers, are addressed: (1) one-way tomography, (2) two-way tomography (reciprocal tomography), (3) acoustic tomographic measurements from straits, (4) coastal acoustic tomography (CAT), (5) river acoustic tomography (RAT), (6) acoustic tomographic measurements of vorticity, and (7) horizontally integrated current measurements using space-time acoustic scintillation analysis technique.

Antony Joseph

2014-01-01T23:59:59.000Z

14

Doppler Effect removal based on instantaneous frequency estimation and time domain re-sampling for wayside acoustic defective bearing detector system  

Science Journals Connector (OSTI)

Abstract The phenomenon of Doppler Effect in the acoustic signal recorded by the wayside acoustic defective bearing detector (ADBD) leads to the difficulty for fault diagnosis of train bearings with a high moving speed, which is a barrier that would badly reduce the effectiveness of online defect detection. In order to improve the performance of condition monitoring of the bearings on a passing train with microphones amounted besides the railway, the elimination of the Doppler Effect should be solved firstly. An effective method for removing the Doppler Effect embedded in the source signal is presented in this paper. The Short Time Fourier Transform-Viterbi Algorithm (STFT-VA) is applied to obtain instantaneous frequency estimation of the distorted signal. According to the acoustic theory of Morse, the non-linear data fitting is then carried out to get the fitting instantaneous frequencies. The necessary parameters for time domain interpolation re-sampling, which is totally based on the kinematic analysis, are acquired from the fitting curve and the re-sampling sequence could be established in the time domain. As a result of the preceding steps, the fault diagnosis for the train bearings could be implemented with the restored signal. The effectiveness of this proposed method is verified by means of a simulation with three adjacent frequencies and an experiment with practical acoustic signals of train bearings with a crack on the outer race and the inner race. The results of the simulation and the experiment indicate that the proposed method has an excellent performance in removing Doppler Effect, and could be well employed to the condition monitoring and fault diagnosis of train bearings with a high moving speed.

Chao Wang; Fanrang Kong; Qingbo He; Fei Hu; Fang Liu

2014-01-01T23:59:59.000Z

15

Acoustic tomography of currents in the ocean by the linearized method of matched nonreciprocity  

Science Journals Connector (OSTI)

The matched nonreciprocity method recently developed for acoustic diagnostics of ocean currents is based on matching the nonreciprocity of a sound field propagating along the current and against it. In this paper...

V. V. Goncharov

2001-01-01T23:59:59.000Z

16

Acoustics at University of Texas: History and current introductory course in physical acoustics.  

Science Journals Connector (OSTI)

As an academic discipline at the University of Texas acoustics began in the 1930s under C. Paul Boner in Physics and Lloyd A. Jeffress in Psychology. World War II saw Boner and many physicsgraduate students go to Harvard for “war work ” largely in underwater acoustics. When the war ended Boner returned and founded the Defense Research Laboratory later named Applied Research Laboratories. Interest in acoustics grew in Physics during the postwar years but eventually waned in the 1950s and 1960s. Acoustical activity developed in the 1960s in the College of Engineering chiefly Electrical Engineering and Mechanical Engineering. Today physical and engineering acoustics is a strong interdisciplinary program at Texas with faculty in several departments in Engineering and still a vestige in Physics. In addition much work on speech hearing and music is done in other parts of the University. Engineering features two basic courses in physical acoustics Acoustics I and II and five specialty courses which are described in an accompanying paper. Here we concentrate on Acoustics I and II which provide an introduction to propagation reflection and transmission refraction normal modes horn theory propagation in stratified fluids absorption and dispersion waveguides directional radiation diffraction and arrays.

David T. Blackstock

2010-01-01T23:59:59.000Z

17

The complex Doppler effect in double negative media  

Science Journals Connector (OSTI)

The Doppler effect in doubly double negative acoustic media is ... ’s functions. It is shown that several Doppler modes can be generated by a monochromatic...

I. V. Lisenkov; S. A. Nikitov

2011-06-01T23:59:59.000Z

18

A Full Field Inversion Method for Acoustic Tomography of Ocean Currents  

Science Journals Connector (OSTI)

An extension of the matched field inversion technique to include oceanic current tomography is considered. Matching of the non-reciprocity of acoustic fields propagated in opposite directions (instead of match...

O. A. Godin; D. Yu. Mikhin; A. V. Mokhov

1995-01-01T23:59:59.000Z

19

Doppler Effect in Flexible and Expandable Light Waveguide and Development of New Fiber-Optic Vibration/Acoustic Sensor  

Science Journals Connector (OSTI)

New principle and a geometrical arrangement of an optical fiber for a vibration/acoustic measurement are proposed in the present paper. The sensor is based on a new finding that a...

Kageyama, Kazuro; Murayama, Hideaki; Uzawa, Kiyoshi; Ohsawa, Isamu; Kanai, Makoto; Akematsu, Yoshiaki; Nagata, Keiich; Ogawa, Tetsu

2006-01-01T23:59:59.000Z

20

Acoustic waves generated from seismic surface waves: propagation properties determined from Doppler sounding observations and normal-mode modelling  

Science Journals Connector (OSTI)

......acoustic waves in the atmosphere, because the wavelength...here omegaa= 3.68 mHz. (Right panel) Spheroidal...When omega omegaa, the atmospheric part of the mode is trapped...HF) wave (3-30 MHz), emitted from the...altitude where the local plasma frequency is equal to......

Juliette Artru; Thomas Farges; Philippe Lognonné

2004-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

On observing acoustic backscattering from salinity turbulence  

Science Journals Connector (OSTI)

It has been hypothesized that at sufficiently high levels of oceanic salinity turbulence it should be possible to observe acoustic backscattering. However there have been limited in situmeasurements to confirm this hypothesis. Using an autonomous underwater vehicle equipped with upward and downward looking 1.2 MHz acoustic Doppler current profilers and with turbulence and fine scale sensors measurements were performed in a region of intense turbulence and a strong salinity gradient. The approach taken was to correlate variations in the backscattered acoustic intensity I with a theoretical acoustic backscattering cross section per volume for salinity turbulence ? s to obtain an estimated scattering cross section per volume ? e . Results indicated that of order 50% of the observed region was characterized by salinity turbulence induced backscattering.

Louis Goodman; Marcos M. Sastre-Córdova

2011-01-01T23:59:59.000Z

22

Doppler Tomography  

E-Print Network [OSTI]

I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

T. R. Marsh

2000-11-01T23:59:59.000Z

23

Anomalous Doppler effects in phononic band gaps  

Science Journals Connector (OSTI)

Doppler effects in periodic acoustic media were studied theoretically and experimentally. Analytical formulas are derived using the Green’s function formalism. We found that a far field observer cannot hear the sound inside a band gap from a stationary source, but a moving source can be heard even if the frequency is inside the gap, and the Doppler shifts can be inverted or anomalously large.

Xinhua Hu; Zhihong Hang; Jensen Li; Jian Zi; C. T. Chan

2006-01-30T23:59:59.000Z

24

Reversed Doppler effect in double negative metamaterials  

Science Journals Connector (OSTI)

Doppler shifts in double negative metamaterials have never been observed. This Rapid Communication presents experimental results on Doppler effect in a double negative acoustic metamaterial. We observed that frequency was downshifted when the source was approaching and upshifted when receding. Notably, while in ordinary media wavelengths corresponding to downshifted frequencies are longer, we demonstrate that in double negative metamaterials wavelengths increase as the frequencies increase. Consequently even though the frequencies were downshifted in front of the moving source, the wavelengths became shorter.

Sam Hyeon Lee; Choon Mahn Park; Yong Mun Seo; Chul Koo Kim

2010-06-14T23:59:59.000Z

25

On the Calculation of Acoustic Intensity Fluctuations Caused by Ocean Currents  

Science Journals Connector (OSTI)

Ocean currents can cause significant and interesting effects on ... of which is valid for different magnitudes of current speed, current gradient, and sound-speed variation. Numerical results indicate that some current

J. S. Robertson; M. J. Jacobson; W. L. Siegmann

1987-01-01T23:59:59.000Z

26

Doppler segmentation  

E-Print Network [OSTI]

is then 2 x 10 Hz/sec. With this frequency modulation rate, the 5 usec pulse would obta1n a 100 MHz bandwidth and, from Equation (3. 2), the system would be able to provide a 1. 5 meter range resolut1on. 5. Transmiss1on Power In the previous s1gnal... OF CONTENTS ABSTRACT . ACKNOWLEDGEMENT TABLE OF CONTENTS LIST OF FIGURES CHAPTER I. INTRODUCTION . CHAPTER II. SYSTEM DEVELOPMENT 1. Range Imaging System 2. Range and Velocity Acquisition by Linear FM Pulse . 3. Infrared Range/Doppler Imaging System...

Yeh, Chih-Ping

2012-06-07T23:59:59.000Z

27

Doppler flowmeter  

DOE Patents [OSTI]

A Doppler flowmeter impulses an ultrasonic fixed-frequency signal obliquely into a slurry flowing in a pipe and a reflected signal is detected after having been scattered off of the slurry particles, whereby the shift in frequencies between the signals is proportional to the slurry velocity and hence slurry flow rate. This flowmeter filters the Doppler frequency-shift signal, compares the filtered and unfiltered shift signals in a divider to obtain a ratio, and then further compares this ratio against a preset fractional ratio. The flowmeter utilizes a voltage-to-frequency convertor to generate a pulsed signal having a determinable rate of repetition precisely proportional to the divergence of the ratios. The pulsed signal serves as the input control for a frequency-controlled low-pass filter, which provides thereby that the cutoff frequency of the filtered signal is known. The flowmeter provides a feedback control by minimizing the divergence. With the cutoff frequency and preset fractional ratio known, the slurry velocity and hence flow will also be determinable.

Karplus, H.H.B.; Raptis, A.C.

1981-11-13T23:59:59.000Z

28

Architectural acoustics  

Science Journals Connector (OSTI)

This tutorial will familiarize people with basic concepts in architectural acoustics. Many slides of actual buildings and a brief audio tape will be used to illustrate connections between the visual appearance of buildings and the qualities of their sonic environment. The presentation will provide examples and explanations of common acoustic experiences in buildings with the under?lying reasons for their occurrence. Architectural acoustics can be characterized as an evolving empirical exploration of basic principles from many areas of acoustics through creative testing in the design and subsequent evaluation of buildings. A historical review of applied acoustical principles translated into the medium of architecture will be presented in four primary areas: (1) subjective impressions including qualities of music speech intelligibility and annoyance which are the basis for current design criteria; (2) room acoustics design with an emphasis on auditoria schools restaurants and other public buildings; (3) providing privacy from unwanted sounds and vibrations through discussion of standard measurement techniques such as sound transmission class (STC); and (4) management of noise from HVAC systems and other equipment and processes in buildings. Interesting case studies will demonstrate how complex the practical application of even relatively simple acoustical principles can be in many buildings. In recent years a significant community of laboratory and applied researchers dedicated to this field has emerged to question and quantify the empirical knowledge base that has been accumulated over time. Recent topics of interest such as new measurement modeling and simulation techniques will be briefly introduced.

Gary W. Siebein

1994-01-01T23:59:59.000Z

29

Development of the doppler electron velocimeter: theory.  

SciTech Connect (OSTI)

Measurement of dynamic events at the nano-scale is currently impossible. This paper presents the theoretical underpinnings of a method for making these measurements using electron microscopes. Building on the work of Moellenstedt and Lichte who demonstrated Doppler shifting of an electron beam with a moving electron mirror, further work is proposed to perfect and utilize this concept in dynamic measurements. Specifically, using the concept of ''fringe-counting'' with the current principles of transmission electron holography, an extension of these methods to dynamic measurements is proposed. A presentation of the theory of Doppler electron wave shifting is given, starting from the development of the de Broglie wave, up through the equations describing interference effects and Doppler shifting in electron waves. A mathematical demonstration that Doppler shifting is identical to the conceptually easier to understand idea of counting moving fringes is given by analogy to optical interferometry. Finally, potential developmental experiments and uses of a Doppler electron microscope are discussed.

Reu, Phillip L.

2007-03-01T23:59:59.000Z

30

Chapter 2 - The History of Measuring Ocean Currents  

Science Journals Connector (OSTI)

Abstract This chapter begins with a brief mention of the contributions made by the ancient mariners in the “discovery” of oceanic currents. Subsequent efforts made by several investigators in this direction, toward development of various devices for measurements of oceanic currents, are then addressed. These include technologies for measurement of surface currents, subsurface and abyssal currents, seafloor boundary layer currents, and vertical profiling of horizontal currents. Surface current measurement technologies include the application of drifting surface bodies; imaging of surface water motion trajectories and patterns with the support of aerial photography, radiometry, and active microwave radar systems; and vector mapping based on current-driven sea-surface wave transport. This is followed by discussion of technologies developed for subsurface and abyssal current measurements. These include spatially integrated measurements based on earth’s magnetism and oceanic sound speed, Lagrangian measurements based on motion of drifting subsurface floats, and Eulerian measurements with the support of a multitude of devices such as suspended drag, propeller revolution registration by mechanical counters, unidirectional impeller current meters, Savonius rotor current meters, ultrasonic acoustic methods, thermal sensors for measurements of turbulent motions, laser Doppler sensors, and acoustic Doppler current meters. This chapter further addresses an important topic of seafloor boundary layer current measurements using mechanical devices and nonmechanical devices such as BASS and MAVS. The chapter concludes with a discussion of technologies developed for vertical profiling of horizontal currents.

Antony Joseph

2014-01-01T23:59:59.000Z

31

Doppler Imaging of Exoplanets and Brown Dwarfs  

E-Print Network [OSTI]

Doppler Imaging produces 2D global maps of rotating objects using high-dispersion spectroscopy. When applied to brown dwarfs and extrasolar planets, this technique can constrain global atmospheric dynamics and/or magnetic effects on these objects in un- precedented detail. I present the first quantitative assessment of the prospects for Doppler Imaging of substellar objects with current facilities and with future giant ground-based telescopes. Observations will have the greatest sensitivity in K band, but the H and L bands will also be useful for these purposes. To assess the number and availability of targets, I also present a compilation of all measurements of photometric variability, rotation period (P), and projected rotational velocity (v sin i) for brown dwarfs and exoplanets. Several bright objects are already accessible to Doppler Imaging with currently available instruments. With the development of giant ground-based telescopes, Doppler Imaging will become feasible for many dozens of brown dwarfs and...

Crossfield, Ian J M

2014-01-01T23:59:59.000Z

32

Angular Doppler effect  

Science Journals Connector (OSTI)

An angular analog of the Doppler effect arising from the quantum of angular momentum carried by circularly polarized photons is presented and developed. Applications to rotational...

Garetz, Bruce A

1981-01-01T23:59:59.000Z

33

Complex Doppler effect in left-handed metamaterials  

E-Print Network [OSTI]

The Doppler shift is investigated in one-dimensional system with moving source. Theoretical findings are confirmed in numerical simulations of optical and acoustical waves propagation in simple metamaterial model, showing the reversed shift and the existence of multiple frequency modes. The properties of these waves are discussed. The effect of absorption on the phenomenon is outlined.

Ziemkiewicz, David

2014-01-01T23:59:59.000Z

34

Cosmology with Doppler Lensing  

E-Print Network [OSTI]

Doppler lensing is the apparent change in object size and magnitude due to peculiar velocities. Objects falling into an overdensity appear larger on its near side, and smaller on its far side, than typical objects at the same redshifts. This effect dominates over the usual gravitational lensing magnification at low redshift. Doppler lensing is a promising new probe of cosmology, and we explore in detail how to utilize the effect with forthcoming surveys. We present cosmological simulations of the Doppler and gravitational lensing effects based on the Millennium simulation. We show that Doppler lensing can be detected around stacked voids or unvirialised over-densities. New power spectra and correlation functions are proposed which are designed to be sensitive to Doppler lensing. We consider the impact of gravitational lensing and intrinsic size correlations on these quantities. We compute the correlation functions and forecast the errors for realistic forthcoming surveys, providing predictions for constraints...

Bacon, David J; Clarkson, Chris; Bolejko, Krzysztof; Maartens, Roy

2014-01-01T23:59:59.000Z

35

Doppler electron velocimetry : notes on creating a practical tool.  

SciTech Connect (OSTI)

The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theoretical beam current signal-to-noise ratio of 25-to-1 is shown for existing electron holography equipment. A detector is also demonstrated with a bandwidth of 1-MHz at a current of 10 pA. Additionally, a Linnik-type interferometer that would increase the available beam current is shown that would offer a more flexible arrangement for Doppler electron measurements over the traditional biprism.

Reu, Phillip L.; Milster, Tom (University of Arizona)

2008-11-01T23:59:59.000Z

36

Relativistic formulation for the Doppler-broadened line profile  

SciTech Connect (OSTI)

Profiles of spectral lines due to the thermal motion of light-emitting particles are formulated based on the classical and the relativistic Doppler effects, respectively. For the classical case, the well-known Doppler-broadened line profile is reproduced. For the relativistic case, the line profile obtained is asymmetrically broadened with increasing temperature. However, the peak frequency remains unshifted, in contrast to blueshifted, as has been predicted in the current literature. Reasoning is given as to why the relativistic Doppler-broadened line profile currently accepted is probably invalid.

Huang, Young-Sea; Chiue, Juang-Han; Huang, Yi-Chi; Hsiung, Te-Chih [Department of Physics, Soochow University, Shih-Lin, Taipei, Taiwan (China); Department of Physics, National Central University, Chung-Li, Taiwan (China)

2010-07-15T23:59:59.000Z

37

Acoustic sounding of the tropical marine boundary layer during GATE  

Science Journals Connector (OSTI)

A vertically pointed monostatic acoustic sounder was installed on the NOAA ShipOCEANOGRAPHER during the Global Atmospheric Research Program Atlantic Tropical Experiment (GATE). The sounderantenna was mounted on a gyrocontrolled platform to compensate for the ship'spitch and roll motions. Extensive measures such as mounting the antenna assembly on a vibration isolator and installing absorbing cuffs had to be taken to reduce interference by ship?generated noise. Back?scattered acoustic data obtained from up to 850 m height describe the tropical marine boundary layer in unique and hitherto unseen detail. During undisturbed weather conditions the facsimile record showed convective plumes rising from the surface of the water up to 400 m. Storm?generated disturbances resulted in a substantial modification of the boundary layer; low?level multilayered undulating inversions formed from cool outflow currents. The inversions persisted for up to 16 hours. Low?level patchy cumulus clouds produced characteristic hummock?shaped acoustic echoes. Analysis of the Doppler frequency shift of the returns allowed the determination of vertical velocities within these clouds and underlying convective plumes.

P. A. Mandics; J. E. Gaynor; F. F. Hall Jr.

1976-01-01T23:59:59.000Z

38

Method and apparatus for ultrasonic doppler velocimetry using speed of sound and reflection mode pulsed wideband doppler  

DOE Patents [OSTI]

According to the present invention, a method and apparatus rely upon tomographic measurement of the speed of sound and fluid velocity in a pipe. The invention provides a more accurate profile of velocity within flow fields where the speed of sound varies within the cross-section of the pipe. This profile is obtained by reconstruction of the velocity profile from the local speed of sound measurement simultaneously with the flow velocity. The method of the present invention is real-time tomographic ultrasonic Doppler velocimetry utilizing a to plurality of ultrasonic transmission and reflection measurements along two orthogonal sets of parallel acoustic lines-of-sight. The fluid velocity profile and the acoustic velocity profile are determined by iteration between determining a fluid velocity profile and measuring local acoustic velocity until convergence is reached.

Shekarriz, Alireza (Kennewick, WA); Sheen, David M. (Richland, WA)

2000-01-01T23:59:59.000Z

39

Current:  

Office of Legacy Management (LM)

OWNE3 (55) OWNE3 (55) -------- past: _--_-------------------- Current: Owner contacted I-J yes ,Fqna; ------------_------------- if yes, date contacted TYPE OF OPEF(ATION ---__-------_____ c] Research & Development -4 Facility Type ci Production scale testing 0 Pilbt Scale 0 Bench Scale Process 0 Theoretical Studies 0 Sample & Analysis C Productian E Disposal/Storage TYPE OF CONTRACi _------_-------_ tlanuf acturi ng University Research Organizaticn q Prime --. _' cl Other information (i.e., cost price, + fixed fee, unit time % material, qtr) ------- ~----~---~~------__--------- YuncOntractor Purchase Order Contract/Purkhase Order # cc-km ----_----~~-----___--------- --------------------------------- OWNEKSHIP: AEC/ME3 AEC/MED GOVT GOUT CONTRACTOR CCNTRACTOR

40

Current:  

Office of Legacy Management (LM)

Qwner contacted n yes Qwner contacted n yes Current: ---------------------L---- if yes, date contacted Research & Development cl Facility Type 0 . Productioff 0 Di 3pcsal /Storage TYPE OF CONTRACT ---------------- q Prime q Subcontractor 0 Purchase Order 0 Other information (i.e. q cast + fixed fee, unit piice, time & material, etr) ------- ------_-----_--------------- 0 Production scale testing 0 Pilot Scale 0 Bench Scale Process a Theoretical Studies Sample & Analysis rcc t O' L~1 q Manufacturing 0 University 0 Research Organization 0 Government Sponsored Facility 0 Other ~--~~---_--__-____--- ' Contract/Purchase Order # __-u~-rc,~~--___~~I_IzI__zpI------------ CONTRACTING PE3IOD: lW/ ------------------ _----__--~-~~--~~_-----~~~~~~~~~~~~~~ ClWNERSHIP:

Note: This page contains sample records for the topic "acoustic doppler current" 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

Doppler characteristics of sea clutter.  

SciTech Connect (OSTI)

Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristics of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.

Raynal, Ann Marie; Doerry, Armin Walter

2010-06-01T23:59:59.000Z

42

2.3.1.2.3 Acoustic Doppler effect  

Science Journals Connector (OSTI)

This document is part of Subvolume A of Volume 3 ‘Oceanography’ of Landolt-Börnstein - Group V Geophysics.

G. Krause

1986-01-01T23:59:59.000Z

43

Ion temperatures in Ormak from Doppler broadening  

Science Journals Connector (OSTI)

Rapid-scanning spectrometric techniques have permitted the determination of ion temperatures in ORMAK as a function of time during the discharge pulse for ORMAK plasma currents up to 180 kA. Emission spectra of hydrogen atoms are Doppler-broadened in the line wings, characteristic of the initial proton motions prior to charge exchange, and give ion "temperatures" generally less than kT+ ~ 300 eV. Impurity spectra of C III and O V, as well as the spectra of He II in helium discharges, lead to somewhat higher ion temperatures ranging up to a maximum of kT+ ~ 700 eV.

J. Rand McNally Jr.; R.V. Neidigh

1973-01-01T23:59:59.000Z

44

Acoustics education in Ukraine  

Science Journals Connector (OSTI)

Acoustics education in Ukraine is considered. In more than 40 universities students learn acoustics: in the acoustics department of the National Technical University in Ukraine (only one department in Ukraine) and many related departments such as Nondestructive Testing Physics Electrical Engineering etc. Acoustical specializations of departments are presented. The most promising and developing acoustical specialization is biomedical acoustics.

Stanislav M. Mayevskyy; Leonid M. Gelman

1999-01-01T23:59:59.000Z

45

Our Old Friend the Doppler Effect  

Science Journals Connector (OSTI)

You’dbe hardput these days topickupany bookonastronomy and notfindsomewhere in its pages mention of the Doppler effect; this might be to dowith the proper ... of coursewe knownowthat this actually isn’t aDoppler

Keith Robinson

2007-01-01T23:59:59.000Z

46

Doppler Effect in a Moving Medium  

Science Journals Connector (OSTI)

The great increase in the accuracy of Doppler measurements in space requires a rigorous definition ... perturbation theorem which generalizes the concept of the Doppler effect as a Lagrangean derivative. Relativi...

Bruno Bertotti

1998-02-01T23:59:59.000Z

47

Echocardiography Signal Modeling Considering Doppler Effect  

Science Journals Connector (OSTI)

A new model for the simulation of Blood Flow signal is introduced. Doppler ultrasound scanning is an important technique that ... -invasively evaluates blood flow. A method for Doppler simulation that previously ...

Hamed Rakhshan; H. Behnam PhD

2008-01-01T23:59:59.000Z

48

"DERIVATION" OF THE DE BROGLIE RELATION FROM THE DOPPLER EFFECT  

E-Print Network [OSTI]

BROGLIE RELATION FROM THE DOPPLER EFFECT Frank S. Crawfordusual derivation of the Doppler effect gives Eq. (l). (The

Crawford, Frank S.

2013-01-01T23:59:59.000Z

49

Activated Fluorescence and Doppler Effect  

Science Journals Connector (OSTI)

... I have tried to observe the speed acquired by the atoms as a L)oppler effect, and I give here a preliminary account of the results, which agree also quantitatively ... the intensity in the broadened line is quite different from that due to the ordinary Doppler ...

FRANCO RASETTI

1926-07-10T23:59:59.000Z

50

Reverse Doppler effect of magnons with negative group velocity scattered from a moving Bragg grating  

Science Journals Connector (OSTI)

We demonstrate experimentally and theoretically the reverse Doppler effect when magnons with negative group velocity are reflected off a moving Bragg grating. This grating, which represents a moving magnonic crystal, is created in an yttrium-iron-garnet film by the periodic strain induced by a traveling surface acoustic wave. As reflection occurs from a crystal rather than from a single reflecting surface, the wave number of the scattered wave is strictly determined by a momentum conservation law. Magnons scattered from the approaching (receding) magnonic crystal are found to be shifted down (up) in frequency. This result, together with an earlier report of reverse Doppler shift from moving sources [D. D. Stancil et al., Phys. Rev. B, 74, 060404(R) (2006)], establishes that the reverse Doppler effect is a universal phenomenon in systems with negative group velocity and not restricted to left-handed materials.

A. V. Chumak; P. Dhagat; A. Jander; A. A. Serga; B. Hillebrands

2010-04-16T23:59:59.000Z

51

Doppler effect in Schwarzschild geometry  

E-Print Network [OSTI]

The Doppler shift considered in general relativity involves mixed contributions of distinct, gravitational and kinematical origins and for most metrics or trajectories it takes a complex form. The expression for the Doppler shift may simplify due to particular symmetries. In Schwarzschild spacetime it factorizes in the case of radial fall for an observer and radial null geodesic. The resulting expression is composed of factors that can be identified with contributions arising from classical, special relativistic and general relativistic origins. This result turns out to be more general: it holds for the whole class of observers travelling parallel to the spatial path of null geodesics when receiving the signal. It also holds for a particular type of in-fall in the case of a Kerr metric.

A. Radosz; A. T. Augousti; K. Ostasiewicz

2007-12-13T23:59:59.000Z

52

Acoustic plug release indicator  

SciTech Connect (OSTI)

The present invention comprises an acoustic plug release indicator system. The acoustic plug release indicatior system comprises a microphone, recording system and operator listening device.

Carter, E.E. Jr.

1984-09-04T23:59:59.000Z

53

Reduction of Doppler effect for the needs of wayside condition monitoring system of railway vehicles  

Science Journals Connector (OSTI)

Technology of acoustic condition monitoring of vehicles in motion is based on the assumption that diagnostically relevant information is stored in the acoustic signal generated by a passing vehicle. Analyzing the possibilities of increasing the effectiveness of condition monitoring of a passing vehicle with stationary microphones, it should be noted that the acoustic signal recorded in these conditions is disturbed with the disturbance resulting from the Doppler effect. Reduction of signal's frequential structure disturbance resulting from the Doppler effect allows efficient analysis of changes in frequential structure of recorded signals and as a result extraction of relevant diagnostic information related with technical condition of running gear of vehicle. This article presents a method for removal of signal's frequential structure disturbances related with relative move of vehicles and stationary monitoring station. For elimination of the frequential non-stationary of signals disturbance-oriented dynamic signal resampling method was used. The paper provides a test of two methods for defining the time course of local disturbance of signal's frequential structure: the method based on the Hilbert transform and the method of analytical description of signal's disturbance based on the knowledge of a phenomenon that causes frequential non-stationarity of signals. As an example, the results of the processing and analysis of acoustic signals recorded by wayside measuring station, during the passage of WM-15A railway vehicle on an experimental track of Polish Railway Institute, are presented.

Jacek Dyba?a; Stanis?aw Radkowski

2013-01-01T23:59:59.000Z

54

Acoustic transducer  

DOE Patents [OSTI]

An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

Drumheller, D.S.

1997-12-30T23:59:59.000Z

55

Acoustic transducer  

DOE Patents [OSTI]

An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

Drumheller, Douglas S. (Cedar Crest, NM)

1997-01-01T23:59:59.000Z

56

Modification of the Doppler Effect due to the Helicity-Rotation Coupling  

E-Print Network [OSTI]

The helicity-rotation coupling and its current empirical basis are examined. The modification of the Doppler effect due to the coupling of photon spin with the rotation of the observer is considered in detail in connection with its applications in the Doppler tracking of spacecraft. Further implications of this coupling and the possibility of searching for it in the intensity response of a rotating detector are briefly discussed.

Bahram Mashhoon

2002-09-22T23:59:59.000Z

57

Doppler effect on target tracking in wireless sensor networks  

Science Journals Connector (OSTI)

This paper presents a new detection algorithm and high speed/accuracy tracker for tracking ground targets in acoustic wireless sensor networks (WSNs). Our detection algorithm naturally accounts for the Doppler effect which is an important consideration for tracking higher-speed targets. This algorithm employs Kalman filtering (KF) with the weighted sensor position centroid being used as the target position measurement. The weighted centroid makes the tracker to be independent of the detection model and changes the tracker to be near optimal, at least within the detection parameters used in this study. Our approach contrasts with previous approaches that employ more sophisticated tracking algorithms with higher computational complexity and use a power law detection model. The power law detection model is valid only for low speed targets and is susceptible to mismatch with detection by the sensors in the field. Our tracking model also enables us to uniquely study various environmental effects on track accuracy, such as the Doppler effect, signal collision, signal delay, and different sampling time. Our WSN tracking model is shown to be highly accurate for a moving target in both linear and accelerated motions. The computing speed is estimated to be 50–100 times faster than the previous more sophisticated methods and track accuracy compares very favorably.

Youngwon Kim An; Seong-Moo Yoo; Changhyuk An; B. Earl Wells

2013-01-01T23:59:59.000Z

58

Acoustic cryocooler  

DOE Patents [OSTI]

An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

Swift, Gregory W. (Santa Fe, NM); Martin, Richard A. (Los Alamos, NM); Radenbaugh, Ray (Louisville, CO)

1990-01-01T23:59:59.000Z

59

Receiver designs for multiuser underwater acoustic communications  

E-Print Network [OSTI]

compensate for the Doppler effect. The receiver discussed in? p = ? p /? p . The Doppler effect compresses or dilateschar- acterizes the Doppler effect in narrowband systems (W

Cho, Steve E.

2012-01-01T23:59:59.000Z

60

Performance degradation of OFDM systems due to Doppler spreading  

E-Print Network [OSTI]

on Jakes’ model for the Doppler effects, and an exponentialand S. Kaiser, “The effects of Doppler spreads in OFDM (A)In particular, the effect of Doppler spreading destroys the

Wang, T J; Proakis, J G; Masry, E; Zeidler, James R

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Measurement of Acoustic Impedance  

Science Journals Connector (OSTI)

The acoustic impedance of a sample of material forming one boundary of a shallow cylindrical cavity can be determined by measuring the sound pressure produced when a known volume current is injected into the cavity from a high impedance source. The volume current is effectively determined by observing the pressure when the cavity is terminated rigidly. An impedance determination is thus reduced to measurement of the complex ratio of two observed voltages. By designing a ring source to suppress the first radial mode of the cavity the upper frequency limit set by uniformity of pressure distribution is extended by at least an octave. By avoiding leaks measurements can also be extended to very low frequencies. Secondary effects due to finite source impedance viscosity and heat losses at the walls have been evaluated. The method appears to be simple rapid and precise.

O. K. El?Mawardi

1948-01-01T23:59:59.000Z

62

Doppler Effect in Positive Rays of Hydrogen  

Science Journals Connector (OSTI)

... THE Balmer lines in the spectra of the positive rays of hydrogen show Doppler displacement d? given by the relation where ? is the wave-length of the light ... of light. J. Stark1, and J. Stark and Steubing2 showed that whereas the Doppler displacement is not a line but a strip of finite width, the maximum displacement ...

B. DASANNACHARYA; G. K. DAS

1944-07-01T23:59:59.000Z

63

Doppler Effect in Light-Scattering  

Science Journals Connector (OSTI)

... the subject classically, the result to be expected is obvious: there should be a Doppler broadening of the incident spectral line, varying with the angle of observation, and determined ... should persist in the scattered light in the same position with no change except a Doppler broadening.

C. V. RAMAN

1931-10-10T23:59:59.000Z

64

Doppler Effect of Nuclear Resonance Level  

Science Journals Connector (OSTI)

... cent. It has been pointed out by Frisch5 that these widths are comparable with the Doppler width which such resonance must show in consequence of the thermal agitation of the capturing ... of the thermal agitation of the capturing nuclei. According to Bethe and Placzek3, the Doppler width is Er being the resonance energy and M the mass of the nucleus. ...

HANS VON HALBAN; HUGH PAXTON

1938-01-15T23:59:59.000Z

65

Fish embryo multimodal imaging by laser Doppler digital holography  

Science Journals Connector (OSTI)

A laser Doppler imaging scheme combined to an upright microscope is proposed. Quantitative Doppler imaging in both velocity norm and direction, as well as amplitude contrast of either...

Gross, Michel; Verrier, Nicolas; Picart, Pascal

66

Stimulated Brillouin scattering from multi-GHz-guided acoustic phonons in  

E-Print Network [OSTI]

laser light, we find that the spontaneous Brillouin signal develops a highly unusual multi modes can Bragg-scatter guided laser light into a counter-propagating optical mode, with a Doppler shift core is surrounded by a pure fused silica cladding, the difference in acoustic properties between

Loss, Daniel

67

Acoustic Based Sketch Recognition  

E-Print Network [OSTI]

investigate this new area, which we call acoustic based sketch recognition, and evaluate the possibilities of using it as a new interaction technique. We focus specifically on building a recognition engine for acoustic sketch recognition. We first propose a...

Li, Wenzhe

2012-10-19T23:59:59.000Z

68

Reversed Doppler effect under reflection from a shock electromagnetic wave  

Science Journals Connector (OSTI)

The possibility of observing the reversed Doppler effect in an electrodynamic system of coupled transmission...

A. M. Belyantsev; A. B. Kozyrev

2002-11-01T23:59:59.000Z

69

Experimental quiescent drifting dusty plasmas and temporal dust acoustic wave growth  

SciTech Connect (OSTI)

We report on dust acoustic wave growth rate measurements taken in a dc (anode glow) discharge plasma device. By introducing a mesh with a variable bias 12-17 cm from the anode, we developed a technique to produce a drifting dusty plasma. A secondary dust cloud, free of dust acoustic waves, was trapped adjacent to the anode side of the mesh. When the mesh was returned to its floating potential, the secondary cloud was released and streamed towards the anode and primary dust cloud, spontaneously exciting dust acoustic waves. The amplitude growth of the excited dust acoustic waves was measured directly along with the wavelength and Doppler shifted frequency. These measurements were compared to fluid and kinetic dust acoustic wave theories. As the wave growth saturated a transition from linear to nonlinear waves was observed. The merging of the secondary and primary dust clouds was also observed.

Heinrich, J. R.; Kim, S.-H.; Meyer, J. K.; Merlino, R. L. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

2011-11-15T23:59:59.000Z

70

Adaptive Model-Based Mine Detection/Localization using Noisy Laser Doppler Vibration Measurements  

SciTech Connect (OSTI)

The acoustic detection of buried mines is hampered by the fact that at the frequencies required for obtaining useful penetration, the energy is quickly absorbed by the ground. A recent approach which avoids this problem, is to excite the ground with a high-level low frequency sound, which excites low frequency resonances in the mine. These resonances cause a low-level vibration on the surface which can be detected by a Laser Doppler Vibrometer. This paper presents a method of quickly and efficiently detecting these vibrations by sensing a change in the statistics of the signal when the mine is present. Results based on real data are shown.

Sullivan, E J; Xiang, N; Candy, J V

2009-04-06T23:59:59.000Z

71

Bragg cell laser intensity modulation: effect on laser Doppler velocimetry measurements  

SciTech Connect (OSTI)

In most laser Doppler velocimetry (LDV) systems, the frequency of one of the two laser beams that intersect to create the probe volume is shifted with an acousto-optic element. It is shown here that Bragg shifting can impose a problematic fluctuation in intensity on the frequency-shifted beam, producing spurious velocity measurements. This fluctuation occurs at twice the Bragg cell frequency, and its relative amplitude to the time average intensity is a function of the ratio of the laser beam diameter to the Bragg cell acoustic wavelength. A physical model and a configuration procedure to minimize adverse effects of the intensity modulations are presented.

Mychkovsky, Alexander G.; Chang, Natasha A.; Ceccio, Steven L.

2009-06-20T23:59:59.000Z

72

Relationships between objective acoustic indices and acoustic comfort evaluation in nonacoustic spaces  

Science Journals Connector (OSTI)

Much attention has been paid to acoustic spaces such as concert halls and recording studios whereas research on nonacoustic buildings/spaces has been rather limited especially from the viewpoint of acoustic comfort. In this research a series of case studies has been carried out on this topic considering various spaces including shopping mall atrium spaces library reading rooms football stadia swimming spaces churches dining spaces as well as urban open public spaces. The studies focus on the relationships between objective acoustic indices such as sound pressure level and reverberation time and perceptions of acoustic comfort. The results show that the acoustic atmosphere is an important consideration in such spaces and the evaluation of acoustic comfort may vary considerably even if the objective acoustic indices are the same. It is suggested that current guidelines and technical regulations are insufficient in terms of acoustic design of these spaces and the relationships established from the case studies between objective and subjective aspects would be useful for developing further design guidelines. [Work supported partly by the British Academy.

Jian Kang

2004-01-01T23:59:59.000Z

73

Acoustics by additive manufacturing:.  

E-Print Network [OSTI]

??This study focuses on exploring the merging field of additive manufacturing and acoustics and introduces a new type of sound absorber which is regulating performance… (more)

Setaki, F.

2012-01-01T23:59:59.000Z

74

Time delay and Doppler tests of the Lorentz symmetry of gravity  

SciTech Connect (OSTI)

Modifications to the classic time-delay effect and Doppler shift in general relativity (GR) are studied in the context of the Lorentz-violating standard-model extension (SME). We derive the leading Lorentz-violating corrections to the time-delay and Doppler shift signals, for a light ray passing near a massive body. It is demonstrated that anisotropic coefficients for Lorentz violation control a time-dependent behavior of these signals that is qualitatively different from the conventional case in GR. Estimates of sensitivities to gravity-sector coefficients in the SME are given for current and future experiments, including the recent Cassini solar conjunction experiment.

Bailey, Quentin G. [Physics Department, Embry-Riddle Aeronautical University, 3700 Willow Creek Road, Prescott, Arizona 86301 (United States)

2009-08-15T23:59:59.000Z

75

Reversed Doppler Effect in Photonic Crystals  

Science Journals Connector (OSTI)

Nonrelativistic reversed Doppler shifts have never been observed in nature and have only been speculated to occur in pathological systems with simultaneously negative effective permittivity and permeability. This Letter presents a different, new physical phenomenon that leads to a nonrelativistic reversed Doppler shift in light. It arises when light is reflected from a moving shock wave propagating through a photonic crystal. In addition to reflection of a single frequency, multiple discrete reflected frequencies or a 10 GHz periodic modulation can also be observed when a single carrier frequency of wavelength 1????m is incident.

Evan J. Reed; Marin Solja?i?; John D. Joannopoulos

2003-09-23T23:59:59.000Z

76

Fish embryo multimodal imaging by laser Doppler digital holography  

E-Print Network [OSTI]

A laser Doppler imaging scheme combined to an upright microscope is proposed. Quantitative Doppler imaging in both velocity norm and direction, as well as amplitude contrast of either zebrafish flesh or vasculature is demonstrated.

Verrier, Nicolas; Picart, Pascal; Gross, Michel

2015-01-01T23:59:59.000Z

77

The doppler effect in light scattered by liquds  

Science Journals Connector (OSTI)

The influence of temperature on the nature of the Doppler effect in light scattered by liquids has been ... of carbon tetrachloride at 70°C. the Doppler components become fainter and broader merging with ... At t...

B. V. Raghavendra Rao

1935-05-01T23:59:59.000Z

78

Doppler effect of subluminal and superluminal sources in eight dimensions  

Science Journals Connector (OSTI)

The study of the relativistic Doppler effect of subluminal and superluminal sources has been ... space. It has been shown that correct Doppler shifts are obtained in the external spaces ... of these sources and t...

H. C. Chandola; B. S. Rajptut

1984-01-30T23:59:59.000Z

79

Acoustic Heating Peter Ulmschneider  

E-Print Network [OSTI]

Acoustic Heating Peter Ulmschneider lnstitut fiir Theoretische Astrophysik der Universitat waves are a viable and prevalent heating mechanism both in early- and in late-type stars. Acoustic heating appears to be a dominant mechanism for situations where magnetic fields are weak or absent

Ulmschneider, Peter

80

Photoacoustic Doppler Effect from Flowing Small Light-Absorbing Particles  

Science Journals Connector (OSTI)

From the flow of a suspension of micrometer-scale carbon particles, the photoacoustic Doppler shift is observed. As predicted theoretically, the observed Doppler shift equals half of that in Doppler ultrasound and does not depend on the direction of laser illumination. This new physical phenomenon provides a basis for developing photoacoustic Doppler flowmetry, which can potentially be used for detecting fluid flow in optically scattering media and especially low-speed blood flow of relatively deep microcirculation in biological tissue.

Hui Fang; Konstantin Maslov; Lihong V. Wang

2007-10-29T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

The possibility of superluminal sources and their Doppler effect  

Science Journals Connector (OSTI)

The ‘Extended Theory of Relativity’ allows in particular extending the Doppler effect formulae to Superluminal sources. This point is...

R. Mignani; E. Recami

1974-10-01T23:59:59.000Z

82

Acoustics as a Human Science  

Science Journals Connector (OSTI)

There was a time when acoustics was only a human science but this changed as philosophers learned to use mathematical and other measurement tools for ordering and validating their thought processes. This century has seen many changes in the description of the field as a whole and the human aspects continue to be among the most perplexing. The highlights of accomplishments to date some observations on our current status of knowledge and some projections into the future are presented for your entertainment—if not for your information.

S. S. Stevens

1972-01-01T23:59:59.000Z

83

Spectroscopic observation of the rotational Doppler effect  

E-Print Network [OSTI]

We report on the first spectroscopic observation of the rotational Doppler shift associated with light beams carrying orbital angular momentum. The effect is evidenced as the broadening of a Hanle/EIT coherence resonance on Rb vapor when the two incident Laguerre-Gaussian laser beams have opposite topological charges. The observations closely agree with theoretical predictions.

S. Barreiro; J. W. R. Tabosa; H. Failache; A. Lezama

2006-07-26T23:59:59.000Z

84

Spectroscopic Observation of the Rotational Doppler Effect  

Science Journals Connector (OSTI)

We report on the first spectroscopic observation of the rotational Doppler shift associated with light beams carrying orbital angular momentum. The effect is evidenced as the broadening of a Hanle electromagnetically induced transparency coherence resonance on Rb vapor when the two incident Laguerre-Gaussian laser beams have opposite topological charges. The observations closely agree with theoretical predictions.

S. Barreiro; J. W. R. Tabosa; H. Failache; A. Lezama

2006-09-12T23:59:59.000Z

85

Airborne Doppler Lidar Wind Field Measurements  

Science Journals Connector (OSTI)

A coherent Doppler lidar has been used in an aircraft to measure the 2-dimensional wind field in a number of different atmospheric situations. The lidar, a pulsed CO2 system, was installed in the NASA Convair 990. Galileo II, and flown in a ...

J. Bilbro; G. Fichtl; D. Fitzjarrald; M. Krause; R. Lee

1984-04-01T23:59:59.000Z

86

A MAGNETIC CALIBRATION OF PHOTOSPHERIC DOPPLER VELOCITIES  

SciTech Connect (OSTI)

The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts); and the convective blueshift, a known correlation between intensity and upflows. Accurate knowledge of the zero point is, however, useful for (1) improving estimates of the Poynting flux of magnetic energy across the photosphere, and (2) constraining processes underlying flux cancellation, the mutual apparent loss of magnetic flux in closely spaced, opposite-polarity magnetogram features. We present a method to absolutely calibrate line-of-sight (LOS) velocities in solar active regions (ARs) near disk center using three successive vector magnetograms and one Dopplergram coincident with the central magnetogram. It exploits the fact that Doppler shifts measured along polarity inversion lines (PILs) of the LOS magnetic field determine one component of the velocity perpendicular to the magnetic field, and optimizes consistency between changes in LOS flux near PILs and the transport of transverse magnetic flux by LOS velocities, assuming that ideal electric fields govern the magnetic evolution. Previous calibrations fitted the center-to-limb variation of Doppler velocities, but this approach cannot, by itself, account for residual convective shifts at the limb. We apply our method to vector magnetograms of AR 11158, observed by the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory, and find clear evidence of offsets in the Doppler zero point in the range of 50-550 m s{sup -1}. In addition, we note that a simpler calibration can be determined from an LOS magnetogram and Dopplergram pair from the median Doppler velocity among all near-disk-center PIL pixels. We briefly discuss shortcomings in our initial implementation, and suggest ways to address these. In addition, as a step in our data reduction, we discuss the use of temporal continuity in the transverse magnetic field direction to correct apparently spurious fluctuations in resolution of the 180 Degree-Sign ambiguity.

Welsch, Brian T.; Fisher, George H. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Sun, Xudong [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

2013-03-10T23:59:59.000Z

87

Distributed Acoustic and Seismic Sensing  

Science Journals Connector (OSTI)

An overview of fiber optic distributed acoustic and seismic sensor system architectures is presented.

Kirkendall, Clay

88

Acoustic cooling engine  

DOE Patents [OSTI]

An acoustic cooling engine with improved thermal performance and reduced internal losses comprises a compressible fluid contained in a resonant pressure vessel. The fluid has a substantial thermal expansion coefficient and is capable of supporting an acoustic standing wave. A thermodynamic element has first and second ends and is located in the resonant pressure vessel in thermal communication with the fluid. The thermal response of the thermodynamic element to the acoustic standing wave pumps heat from the second end to the first end. The thermodynamic element permits substantial flow of the fluid through the thermodynamic element. An acoustic driver cyclically drives the fluid with an acoustic standing wave. The driver is at a location of maximum acoustic impedance in the resonant pressure vessel and proximate the first end of the thermodynamic element. A hot heat exchanger is adjacent to and in thermal communication with the first end of the thermodynamic element. The hot heat exchanger conducts heat from the first end to portions of the resonant pressure vessel proximate the hot heat exchanger. The hot heat exchanger permits substantial flow of the fluid through the hot heat exchanger. The resonant pressure vessel can include a housing less than one quarter wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir. The frequency of the acoustic driver can be continuously controlled so as to maintain resonance.

Hofler, Thomas J. (Los Alamos, NM); Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Santa Fe, NM); Migliori, Albert (Santa Fe, NM)

1988-01-01T23:59:59.000Z

89

Acoustic well cleaner  

DOE Patents [OSTI]

A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore.

Maki, Jr., Voldi E. (11904 Bell Ave., Austin, TX 78759-2415); Sharma, Mukul M. (Dept. of Petroleum Engr. Univ. of Texas, Austin, TX 78712)

1997-01-21T23:59:59.000Z

90

Acoustical heat pumping engine  

DOE Patents [OSTI]

The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

Wheatley, J.C.; Swift, G.W.; Migliori, A.

1983-08-16T23:59:59.000Z

91

Rotational Doppler effect in left-handed materials  

Science Journals Connector (OSTI)

We explain the rotational Doppler effect associated with light beams carrying with orbital angular momentum in left-handed materials (LHMs). We demonstrate that the rotational Doppler effect in LHMs is unreversed, which is significantly different from the axial Doppler effect. The physics underlying this intriguing effect is the combined contributions of negative phase velocity and the inverse screw of the wave front. We find that the additional Doppler effect caused by Gouy phase and wave-front curvature should be reversed, because of the negative index. In the normal dispersion region, the rotational Doppler effect induces an upstream energy flow but a downstream momentum flow. In the anomalous dispersion region, however, the rotational Doppler effect produces a downstream energy flow but an upstream momentum flow. We theoretically predict that the rotational Doppler effect can induce a transfer of angular momentum of the LHM to orbital angular momentum of the beam.

Hailu Luo; Shuangchun Wen; Weixing Shu; Zhixiang Tang; Yanhong Zou; Dianyuan Fan

2008-09-05T23:59:59.000Z

92

IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 0510, NO. 2, APRIL 1985 123 Reciprocal Acoustic Transmissions: Instrumentation for  

E-Print Network [OSTI]

Transmissions: Instrumentation for Mesoscale Monitoring of Ocean Currents PETER F. WORCESTER, ROBERT C. SPINDEL in opposite directionsbetweentwo pointsin midocean, one can separate the effects of ocean currents on acoustic to measure ocean currents. Acoustic transceivers have been designedand built to measure the mean currents

Frandsen, Jannette B.

93

History of proposed Acoustical Society standard on “Underwater Passive Acoustic Monitoring for Bioacoustic Applications”.  

Science Journals Connector (OSTI)

In 2005 an ASA working group was formed to examine whether a standard should exist for “Passive Acoustic Monitoring for Marine Mammal Mitigation for Seismic Surveys”. Public discussions at subsequent meetings quickly showed that no consensus existed for specifying hardware requirements for passive acoustic measurements but consensus did seem possible for specifying “minimum requirements for recording and reporting bioacoustic data”. The proposed standard was renamed “Underwater Passive Acoustic Monitoring for Bioacoustic Applications” with three defined goals: (1) providing a set of requirements for information to be documented while recording acoustic data at sea (metadata requirements); (2) detailing the minimum information about acoustic hardware and software to be included when reporting results in gray or peer?reviewed literature; and (3) specifying metrics to be used when summarizing the features of an acoustic signal such as signal?to?noise ratio. A set of recommended best?practice procedures and equipment capabilities would also be included as an informative annex. After languishing for several years an attempt is being made to develop the standard further. This presentation describes the ASA standard outlines the development process and sketches the current thinking on the standard with an emphasis on the metrics portion.

Aaron Thode; David K. Mellinger

2010-01-01T23:59:59.000Z

94

HADES - Hydrophone for Acoustic Detection at South Pole  

E-Print Network [OSTI]

The South Pole Acoustic Test Setup (SPATS) is located in the upper part of the optical neutrino observatory IceCube, currently under construction. SPATS consists of four strings at depths between 80 m and 500 m below the surface of the ice with seven stages per string. Each stage is equipped with an acoustic sensor and a transmitter. Three strings (string A-C) were deployed in the austral summer 2006/07. SPATS was extended by a fourth string (string D) with second generation sensors and transmitters in 2007/08. One second generation sensor type HADES (Hydrophone for Acoustic Detection at South Pole) consists of a ring-shaped piezo-electric element coated with polyurethane. The development of the sensor, optimization of acoustic transmission by acoustic impedance matching and first in-situ results will be discussed.

Semburg, Benjamin

2008-01-01T23:59:59.000Z

95

HADES - Hydrophone for Acoustic Detection at South Pole  

E-Print Network [OSTI]

The South Pole Acoustic Test Setup (SPATS) is located in the upper part of the optical neutrino observatory IceCube, currently under construction. SPATS consists of four strings at depths between 80 m and 500 m below the surface of the ice with seven stages per string. Each stage is equipped with an acoustic sensor and a transmitter. Three strings (string A-C) were deployed in the austral summer 2006/07. SPATS was extended by a fourth string (string D) with second generation sensors and transmitters in 2007/08. One second generation sensor type HADES (Hydrophone for Acoustic Detection at South Pole) consists of a ring-shaped piezo-electric element coated with polyurethane. The development of the sensor, optimization of acoustic transmission by acoustic impedance matching and first in-situ results will be discussed.

Benjamin Semburg; for the IceCube Collaboration

2008-11-07T23:59:59.000Z

96

History of engineering acoustics  

Science Journals Connector (OSTI)

At the Providence RI meeting in December 1955 it was proposed to add three new technical committees to the original seven established about a year earlier. Two of the new ones Audio Engineering and Electroacoustics and Sonic and Ultrasonic Engineering are precursors of the present Engineering Acoustics Technical Committee. In 1961 the name of the former committee was shortened to Electroacoustics and I began to attend their meetings. In 1964 the scope of the committee was broadened and its present name of Engineering Acoustics adopted. Early repeatable experiments in engineering acoustics have been attributed to Benjamin Franklin and mostly anecdotal evidence exists before that. Modern developments involve interdisciplinary involvements with all acoustics and specifically with the discovery of new materials applications of their properties and inventions of a wide variety of devices for producing receiving and using acoustics. Henry Joule Bell Berliner Edison the Curie brothers DeForest and Fessenden will be among those noted with some related recognition of them by the Engineering Acoustics TC.

Stanley L. Ehrlich

2000-01-01T23:59:59.000Z

97

Design of a Doppler reflectometer for KSTAR  

SciTech Connect (OSTI)

A Doppler reflectometer has been designed to measure the poloidal propagation velocity on the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. It has the operating frequency range of V-band (50-75 GHz) and the monostatic antenna configuration with extraordinary mode (X-mode). The single sideband modulation with an intermediate frequency of 50 MHz is used for the heterodyne measurement with the 200 MHz in-phase and quadrature (I/Q) phase detector. The corrugated conical horn antenna is used to approximate the Gaussian beam propagation and it is installed together with the oversized rectangular waveguides in the vacuum vessel. The first commissioning test of the Doppler reflectometer system on the KSTAR tokamak is planned in the 2014 KSTAR experimental campaign.

Lee, K. D., E-mail: kdlee@nfri.re.kr; Nam, Y. U.; Seo, Seong-Heon; Kim, Y. S. [National Fusion Research Institute, Yuseong, Daejeon 305-333 (Korea, Republic of)

2014-11-15T23:59:59.000Z

98

ROTATIONAL DOPPLER BEAMING IN ECLIPSING BINARIES  

SciTech Connect (OSTI)

In eclipsing binaries the stellar rotation of the two components will cause a rotational Doppler beaming during eclipse ingress and egress when only part of the eclipsed component is covered. For eclipsing binaries with fast spinning components this photometric analog of the well-known spectroscopic Rossiter-McLaughlin effect can exceed the strength of the orbital effect. Example light curves are shown for a detached double white dwarf binary, a massive O-star binary and a transiting exoplanet case, similar to WASP-33b. Inclusion of the rotational Doppler beaming in eclipsing systems is a prerequisite for deriving the correct stellar parameters from fitting high-quality photometric light curves and can be used to determine stellar obliquities as well as, e.g., an independent measure of the rotational velocity in those systems that may be expected to be fully synchronized.

Groot, Paul J., E-mail: pgroot@astro.ru.nl [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

2012-01-20T23:59:59.000Z

99

Schwarzschild orbital topography and high Doppler blueshifts  

Science Journals Connector (OSTI)

... high Doppler blueshift of forward light emission from material particles in circular orbit in a Schwarzschild field at and near r = 3GM/c2, which they claim is the radius ... supposed effect rests on a basic confusion concerning the orbital topography and energetics in the Schwarzschild field. Outside the event horizon, at r = 2G7V//C2, there are three ...

W. R. STOEGER

1975-03-20T23:59:59.000Z

100

Unusual Doppler effect in He II  

Science Journals Connector (OSTI)

Many years ago Khalatnikov described unusual properties of the Doppler shift for the second sound in He II, first of all the ‘‘back-entrainment’’ effect: at some temperatures (at the beginning of the roton region) the center of the spreading sound moves in the direction opposite to the normal-component velocity vn [?u2=?(T)vn, ?(T?0.6 K)Doppler shift of the first and fourth sounds as a trivial, ‘‘kinematic’’ effect: the center of the spreading sound moves with the velocity of the liquid as a whole [?u1,4?j/p=(1-?n/?)vs]. We show that the real situation is quite different. We find (1) the coefficient K in the Doppler-shift expression, ?u1,4=(1-K1,4?n/?)vs, substantially differs from the kinematic value K=1:?K?max reaches some tens. (2) K1(T) and K4(T) have different (qualitatively opposite) nontrivial temperature dependences, in particular a high peak (modulo) at the beginning of the roton region. (3) K1,4(T) can be negative: K1effect: the center of the spreading sound moves faster than the flowing superfluid part of the liquid itself.

Y. A. Nepomnyashchy

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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.


101

Pursuing the M.Eng. in acoustics through distance education from Penn State  

Science Journals Connector (OSTI)

Since 1987 the Graduate Program in Acoustics at Penn State has been providing remote access to graduate level education leading to the M.Eng. degree in Acoustics. Course lecture content is currently broadcast as a live-stream via Adobe Connect to distance students scattered throughout North America and around the world while archived recordings allow distance students to access lecture material at their convenience. Distance Education students earn the M.Eng. in Acoustics degree by completing 30 credits of coursework (six required core courses and four electives) and writing a capstone paper. Courses offered for distance education students include: fundamentals of acoustics and vibration electroacoustic transducers signal processing acoustics in fluid media sound and structure interaction digital signal processing aerodynamic noise acoustic measurements and data analysis ocean acoustics architectural acoustics noise control engineering nonlinear acoustics outdoor sound propagation computational acoustics flow induced noise spatial sound and 3D audio marine bioacoustics and acoustics of musical instruments. This poster will summarize the distance education experience leading to the M.Eng. degree in Acoustics from Penn State showcasing student demographics capstone paper topics enrollment statistics and trends and the success of our graduates.

2014-01-01T23:59:59.000Z

102

Acoustic Building Infiltration Measurement System (ABIMS)  

Broader source: Energy.gov [DOE]

The Acoustic Building Infilitration Measurement System project is developing an acoustic method of measuring the infiltration of a building envelope.

103

Doppler Effect in Resonant Photoemission from SF6: Correlation between Doppler Profile and Auger Emission Anisotropy  

Science Journals Connector (OSTI)

Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. The measured Doppler profiles are analyzed by the model simulation that takes account of the anisotropy of the Auger emission in the molecular frame. The Auger anisotropy extracted from the data decreases with an increase in the F-SF5 internuclear distance.

M. Kitajima; K. Ueda; A. De Fanis; T. Furuta; H. Shindo; H. Tanaka; K. Okada; R. Feifel; S. L. Sorensen; F. Gel’mukhanov; A. Baev; H. Ågren

2003-11-20T23:59:59.000Z

104

Spacetime transformation acoustics  

E-Print Network [OSTI]

A recently proposed analogue transformation method has allowed the extension of transformation acoustics to general spacetime transformations. We analyze here in detail the differences between this new analogue transformation acoustics (ATA) method and the standard one (STA). We show explicitly that STA is not suitable for transformations that mix space and time. ATA takes as starting point the acoustic equation for the velocity potential, instead of that for the pressure as in STA. This velocity-potential equation by itself already allows for some transformations mixing space and time, but not all of them. We explicitly obtain the entire set of transformations that do not leave its form invariant. It is in these cases that ATA shows its true potential, allowing for building a transformation acoustics method that enables the full range of spacetime transformations. We provide an example of an important transformation which cannot be achieved with STA. Using this transformation, we design and simulate an acoustic frequency converter via the ATA approach. Furthermore, in those cases in which one can apply both the STA and ATA approaches, we study the different transformational properties of the corresponding physical quantities.

C. García-Meca; S. Carloni; C. Barceló; G. Jannes; J. Sánchez-Dehesa; A. Martínez

2014-07-08T23:59:59.000Z

105

Autonomous adaptive acoustic relay positioning  

E-Print Network [OSTI]

We consider the problem of maximizing underwater acoustic data transmission by adaptively positioning an autonomous mobile relay so as to learn and exploit spatial variations in channel performance. The acoustic channel ...

Cheung, Mei Yi, S.M. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

106

Effect of speckle pattern on laser Doppler velocimeters  

Science Journals Connector (OSTI)

The effect of speckle pattern on laser Doppler velocimeters is studied theoretically and experimentally. We have found that dynamic speckle patterns can cause error in velocity...

Lv, Liang; Gui, Huaqiao; Zhao, Tianpeng; Xu, Jun; He, Deyong; Wang, Anting; Li, Feng; Ming, Hai; Xie, Jianping

2005-01-01T23:59:59.000Z

107

Stratus Cloud Drizzle Retrieval During SHEBA from MMCR Doppler...  

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

when the updrafts and downdrafts are averaged out. The second contribution is the effect of turbulence on the spread of the Doppler spectrum. Both of these contributions...

108

Design of new seismometer based on laser Doppler effect  

Science Journals Connector (OSTI)

In order to improve the resolution of seismic acquisition, a new seismic acquisition system based on tangential laser Doppler effect with an optimized differential optical...

Du, Zhenhui; Huang, Fuxiang; Jiang, Chengzhi; Tao, Zhifei; Gao, Hua; Lv, Lina

2004-01-01T23:59:59.000Z

109

PRECISE DOPPLER MONITORING OF BARNARD'S STAR  

SciTech Connect (OSTI)

We present 248 precise Doppler measurements of Barnard's Star (Gl 699), the second nearest star system to Earth, obtained from Lick and Keck Observatories during the 25 years between 1987 and 2012. The early precision was 20 m s{sup -1} but was 2 m s{sup -1} during the last 8 years, constituting the most extensive and sensitive search for Doppler signatures of planets around this stellar neighbor. We carefully analyze the 136 Keck radial velocities spanning 8 years by first applying a periodogram analysis to search for nearly circular orbits. We find no significant periodic Doppler signals with amplitudes above {approx}2 m s{sup -1}, setting firm upper limits on the minimum mass (Msin i) of any planets with orbital periods from 0.1 to 1000 days. Using a Monte Carlo analysis for circular orbits, we determine that planetary companions to Barnard's Star with masses above 2 M {sub Circled-Plus} and periods below 10 days would have been detected. Planets with periods up to 2 years and masses above 10 M {sub Circled-Plus} (0.03 M {sub Jup}) are also ruled out. A similar analysis allowing for eccentric orbits yields comparable mass limits. The habitable zone of Barnard's Star appears to be devoid of roughly Earth-mass planets or larger, save for face-on orbits. Previous claims of planets around the star by van de Kamp are strongly refuted. The radial velocity of Barnard's Star increases with time at 4.515 {+-} 0.002 m s{sup -1} yr{sup -1}, consistent with the predicted geometrical effect, secular acceleration, that exchanges transverse for radial components of velocity.

Choi, Jieun; Marcy, Geoffrey W.; Howard, Andrew W.; Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)] [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); McCarthy, Chris [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States)] [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States)] [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States); Johnson, John A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)] [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Wright, Jason T., E-mail: jieun_eb@berkeley.edu [Department of Astronomy, The Pennsylvania State University, University Park, PA 16802 (United States)

2013-02-20T23:59:59.000Z

110

Doppler effect of time and space  

E-Print Network [OSTI]

This paper shows as the relativistic Doppler effect can be extended also to time and space associated to moving bodies. This extension derives from the analysis of the wave-fronts of the light emitted by a moving source in inertial motion in the empty space, as viewed from the stationary reference. Indeed, time and space can be represented by the same vector quantities, which appear asymmetrical in forward and back direction along the path of the moving body. Consequently, the whole size of the moving bodies dilates along the direction of their motion, as their path. Thought experiments and real facts demonstrate this issue.

Giovanni Zanella

2010-10-28T23:59:59.000Z

111

Good classroom acoustics are a good investment for America  

Science Journals Connector (OSTI)

Buzz Towne’s idealism sparked ASA’s current activities to improve classroom acoustics including ANSI S12 WG43’s activity to produce an American standard for classroom acoustics. But idealism alone may not suffice to realize the reforms Buzz sought. It will help if advocates can show that good classroom acoustics are a good investment for community and nation. Absent were the resources necessary for serious economic cost?benefit studies some very informal ‘‘back?of?the?envelope’’ engineering estimates were made by acousticians audiologists and material vendors. All assume 20 year life cycles for new and renovated classrooms. In one scenario costs for quiet HVAC and sound absorbing ceilings are shown to be a small fraction of costs for ordinary school construction yielding substandard acoustics. In another scenario costs for quiet classroom HVAC are shown to be small compared to annual operating costs per student. A third scenario shows that a modest but plausible assumed increase in average lifetime earnings generously will repay the initial costs for good acoustics. These scenarios do not consider the economic costs of bad acoustics including high dropout rates truancy juvenile crime and teacher burnout. The authors hope to inspire others to more fully study the economic social and educational benefits of good acoustics.

David Lubman; Louis C. Sutherland

1999-01-01T23:59:59.000Z

112

Acoustic wind and wind?shear measuring system  

Science Journals Connector (OSTI)

An acoustic wind?profiling system designed to detect hazardous wind?shear conditions in the airport environment has been developed during the past four years. The system installed at Dulles International Airport consists of a vertically pointed transmitter surrounded by three receivers 290?m distant and separated by 120° in azimuth. Electronically steered receiver beams track the upward propagating transmitted tone burst and collect the scatteredacoustic signals. The Doppler frequency shift of the returns is analyzed digitally to determine the horizontal wind at 20 height levels in 30?m increments. Unique design features of the system such as the steered receiver antenna are described. A one?leg prototype of the Dulles system was installed and tested at Table Mountain near Boulder CO. Winds measured by the prototype acoustic system compared well with those determined by an FM?CW radar and a balloon?borne anemometer. Noisegenerated by rain and surface winds exceeding 16 m sec?1 proved to be the major limitations for the acoustic system. Preliminary results from the Dulles system are also presented.

P. A. Mandics; D. W. Beran

1976-01-01T23:59:59.000Z

113

Imaging doppler velocimeter with downward heterodyning in the optical domain  

DOE Patents [OSTI]

In a Doppler velocimeter, the incoming Doppler-shifted beams are heterodyned to reduce their frequencies into the bandwidth of a digital camera. This permits the digital camera to produce at every sampling interval a complete two-dimensional array of pixel values. This sequence of pixel value arrays provides a velocity image of the target.

Reu, Phillip L; Hansche, Bruce D

2013-05-21T23:59:59.000Z

114

"An analysis of the classical Doppler Effect"[1] revisited  

E-Print Network [OSTI]

After having shown that the formula which describes the Doppler effect in the general case holds only in the case of the "very high" frequency assumption, we derive free of assumptions Doppler formulas for two scenarios presented in the revisited paper.

Bernhard Rothenstein; Corina Nafornita

2004-03-26T23:59:59.000Z

115

The Doppler Effect in the Molecular Scattering of Radiation  

Science Journals Connector (OSTI)

... the irregular alterations in the wave-length of the scattered radiation produced (in accordance with Doppler's principle) by the thermal movements of the molecules. There is one interesting feature ... ) by the thermal movements of the molecules. There is one interesting feature of the Doppler ...

C. V. RAMAN

1919-05-01T23:59:59.000Z

116

Electric Currents Electric Current  

E-Print Network [OSTI]

coefficient of resistivity Electric Power: = = = Also, = . So, = = 2 = 2 Unit of Power(P): Watt (WChapter 18 Electric Currents #12;Electric Current: Flow of electric charge Current is flow of positive charge. In reality it's the electron moves in solids- Electron current. #12;Ohm's Law : Resistance

Yu, Jaehoon

117

E-Print Network 3.0 - al ecocardiograma doppler Sample Search...  

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

and ionized atmosphere. Those waves have been Summary: a variety of techniques, such as HF Doppler sounding or GPS receivers. The HF Doppler technique... the performances of the...

118

E-Print Network 3.0 - airborne doppler radar Sample Search Results  

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

during the austral summer. The study uses Doppler radar data... to understand this phenomenol- ogy because the convection was sampled by ship and aircraft Doppler radars over......

119

Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra  

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

Mixed-Phase Cloud Retrievals Using Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra M. D. Shupe, S. Y. Matrosov, and T. L. Schneider National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado P. Kollias Rosentiel School of Marine Atmospheric Sciences University of Miami Miami, Florida Introduction The radar Doppler spectrum contains a wealth of information on cloud microphysical properties. Typically, radar-based cloud retrievals use only the zeroth or first moments of the Doppler spectrum - reflectivity and mean Doppler velocity - to derive quantities such as cloud water content and particle characteristic size (e.g., Liou and Sassen 1994; Matrosov et al. 2002). When using only the moments of the Doppler spectrum, important spectral information can be lost, particularly when the spectrum is

120

Rotational Doppler effect in x-ray photoionization  

SciTech Connect (OSTI)

The energy of the photoelectron experiences a red or blue Doppler shift when the molecule recedes from the detector or approaches him. This results in a broadening of the photoelectron line due to the translational thermal motion. However, the molecules also have rotational degrees of freedom and we show that the translational Doppler effect has its rotational counterpart. This rotational Doppler effect leads to an additional broadening of the spectral line of the same magnitude as the Doppler broadening caused by translational thermal motion. The rotational Doppler broadening as well as the rotational recoil broadening is sensitive to the molecular orbital from which the photoelectron is ejected. This broadening should be taken into account in analysis of x-ray photoemission spectra of super-high resolution and it can be directly observed using x-ray pump-probe spectroscopy.

Sun Yuping; Wang Chuankui [College of Physics and Electronics, Shandong Normal University, 250014 Jinan (China); Theoretical Chemistry, Roslagstullsbacken 15, Royal Institute of Technology, S-106 91 Stockholm (Sweden); Gel'mukhanov, Faris [Theoretical Chemistry, Roslagstullsbacken 15, Royal Institute of Technology, S-106 91 Stockholm (Sweden)

2010-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Use of GPS network data for HF Doppler measurements interpretation  

E-Print Network [OSTI]

The method of measurement of Doppler frequency shift of ionospheric signal - HF Doppler technique - is one of well-known and widely used methods of ionosphere research. It allows to research various disturbances in the ionosphere. There are some sources of disturbances in the ionosphere. These are geomagnetic storms, solar flashes, metrological effects, atmospheric waves. This method allows to find out the influence of earthquakes, explosions and other processes on the ionosphere, which occur near to the Earth. HF Doppler technique has the high sensitivity to small frequency variations and the high time resolution, but interpretation of results is difficult. In this work we make an attempt to use GPS data for Doppler measurements interpretation. Modeling of Doppler frequency shift variations with use of TEC allows to separate ionosphere disturbances of medium scale.

Petrova, Inna R; Latypov, Ruslan R

2014-01-01T23:59:59.000Z

122

Rotational Doppler effect in x-ray photoionization  

Science Journals Connector (OSTI)

The energy of the photoelectron experiences a red or blue Doppler shift when the molecule recedes from the detector or approaches him. This results in a broadening of the photoelectron line due to the translational thermal motion. However, the molecules also have rotational degrees of freedom and we show that the translational Doppler effect has its rotational counterpart. This rotational Doppler effect leads to an additional broadening of the spectral line of the same magnitude as the Doppler broadening caused by translational thermal motion. The rotational Doppler broadening as well as the rotational recoil broadening is sensitive to the molecular orbital from which the photoelectron is ejected. This broadening should be taken into account in analysis of x-ray photoemission spectra of super-high resolution and it can be directly observed using x-ray pump-probe spectroscopy.

Yu-Ping Sun; Chuan-Kui Wang; Faris Gel’mukhanov

2010-11-10T23:59:59.000Z

123

Real-time bulk-motion-correction free Doppler variance optical coherence tomography for choroidal capillary vasculature imaging  

E-Print Network [OSTI]

The effect of sample movement on the color Doppler andmotion effect can be neglected here. The Doppler variance

Liu, Gangjun; Qi, Wenjuan; Yu, Lingfeng; Chen, Zhongping

2011-01-01T23:59:59.000Z

124

Laser Doppler vibrometer employing active frequency feedback  

SciTech Connect (OSTI)

We present a heterodyne Michelson interferometer for vibration measurement in which feedback is used to obviate the need to unwrap phase data. The Doppler shift of a vibrating target mirror is sensed interferometrically and compensated by means of a voltage-controlled oscillator driving an acousto-optic modulator. For frequencies within the servo bandwidth, the oscillator control voltage provides a direct measurement of the target velocity. Outside the servo bandwidth, phase-sensitive detection is used to evaluate high-frequency displacements. This approach is of great interest for the frequently-occurring situation where vibration amplitudes at low frequency exceed an optical wavelength, but knowledge of the vibration spectrum at high frequency is important as well.

Chijioke, Akobuije; Lawall, John

2008-09-20T23:59:59.000Z

125

Acoustical performance testing of duct silencers  

Science Journals Connector (OSTI)

The test method used in North America to evaluate the acoustical performance of duct silencers is ASTM E477. The ASTM standard provides an approved method for measuring the aerodynamic pressure drop dynamic insertion loss and self?generated noise of duct silencers. Unfortunately restrictions on the construction of the test duct in the current standard cause erroneous results in the measurement of insertion loss at low frequencies. These errors are due to acoustic resonances that occur naturally in the empty test duct. It is recommended that the standard be modified to require anechoic terminations at both ends of the test duct. It is also recommended that more specific design criteria for the source chamber be established and that a new section be added to provide for the measurement of the radiated noise from the casing of the test specimen. Specific recommendations relating to all of these issues will be provided.

2002-01-01T23:59:59.000Z

126

Acoustic paramagnetic logging tool  

DOE Patents [OSTI]

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth3 s magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation . The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores.

Vail, III, William B. (Bothell, WA)

1988-01-01T23:59:59.000Z

127

Modern Schoolroom Acoustics  

Science Journals Connector (OSTI)

Many teachers are faced with conducting classes in buildings that were obsolete thirty years ago. Others are or soon will be teaching in new schools which are in no way modern in some of their basic construction details. A classroom laboratory or auditorium is fundamentally a shelter in which the basic functions are seeing and hearing. Daylight provides satisfactory seeing a large part of the time. In spite of this about $1.50 per square foot is the average investment for auxiliary lighting while satisfactory acoustics is often completely overlooked or is the target of severe economy measures. Architects today are often eliminating or seriously compromising on the acoustical treatment expenditure while spending lavishly for less important materials. Eighty?five percent articulation will usually result in satisfactory hearing for adults because the context supplies the transitional ties. For children however especially the very young each word and every syllable is important. Excessive reverberation time or poor sound distribution may create conditions which seriously handicap the students and teachers alike. Modern medical methods have shown that poor eyes and poor hearing are often responsible for backward children who are really average or above average in mental ability. It is inexcusable to add to their natural handicaps those of poor architecture and poor engineering. Good acoustics is as fundamental as lighting and ventilation and much more attention should be paid to this phase of school design.

L. F. Yerges; M. A. Smith

1949-01-01T23:59:59.000Z

128

Cylindrical Acoustic Levitator/Concentrator  

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

Cylindrical Acoustic Levitator/Concentrator Cylindrical Acoustic Levitator/Concentrator Cylindrical Acoustic Levitator/Concentrator A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. Available for thumbnail of Feynman Center (505) 665-9090 Email Cylindrical Acoustic Levitator/Concentrator A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that

129

Acoustic emission during polymer crystallization  

Science Journals Connector (OSTI)

... .G.; part support to L.K.) Acoustic Emission, Special Technical Publication 505, ASTM, Philadelphia, 1971; Grabec, I. & Peterlin, A. J. Polymer Sci. ...

A. Galeski; L. Koenczoel; E. Piorkowska; E. Baer

1987-01-01T23:59:59.000Z

130

Acoustic Character Of Hydraulic Fractures In Granite  

E-Print Network [OSTI]

Hydraulic fractures in homogeneous granitic rocks were logged with conventional acoustic-transit-time, acoustic-waveform, and acoustic-televiewer logging systems. Fractured intervals ranged in depth from 45 to 570m. and ...

Paillet, Frederick I.

1983-01-01T23:59:59.000Z

131

E-Print Network 3.0 - anomalous doppler effect Sample Search...  

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

effect Search Powered by Explorit Topic List Advanced Search Sample search results for: anomalous doppler effect...

132

History of the Acoustical Society of America’s standard on “Underwater Passive Acoustic Monitoring for Bioacoustic Applications”: Metadata issues.  

Science Journals Connector (OSTI)

In 2005 an ASA working group was formed to examine whether a standard should exist for “Passive Acoustic Monitoring for Marine Mammal Mitigation for Seismic Surveys”. Public discussions at subsequent meetings quickly showed no consensus existed for specifying hardware requirements for passive acoustic measurements but consensus did seem possible for specifying “minimum requirements for recording and reporting bioacoustic data.” The proposed standard was renamed “Underwater Passive Acoustic Monitoring for Bioacoustic Applications” with three defined goals: (1) providing a set of requirements for information to be documented while recording acoustic data at sea (metadata requirements); (2) detailing the minimum information about acoustic hardware and software to be included when reporting results in gray or peer?reviewed literature; and (3) specifying metrics to be used when summarizing the features of an acoustic signal. After languishing for several years an attempt is being made to develop the standard further. This presentation describes what ASA standards are outlines the development process and sketches the current status of the standard with an emphasis on metadata issues.

Aaron Thode; David K. Mellinger

2010-01-01T23:59:59.000Z

133

Verification of three-dimensional laser Doppler velocimeter measurements  

Science Journals Connector (OSTI)

An experimental comparison method is proposed for the verification of mean flow and turbulence measurements obtained with a three-dimensional laser Doppler velocimeter system. Such measurements can include large ...

R. D. Mehta

1990-03-01T23:59:59.000Z

134

Comparison of 2- and 10-µm Coherent Doppler Lidar Performance  

Science Journals Connector (OSTI)

The performance of 2- and 10-µm coherent Doppler lidar is presented in terms of the statistical distribution of the maximum-likelihood velocity estimator from simulations for fixed range resolution and fixed velocity search space as a function of ...

Rod Frehlich

1995-04-01T23:59:59.000Z

135

Doppler optical coherence microscopy for studies of cochlear mechanics  

E-Print Network [OSTI]

The possibility of measuring subnanometer motions with micron scale spatial resolution in the intact mammalian cochlea using Doppler optical coherence microscopy (DOCM) is demonstrated. A novel DOCM system is described ...

Hong, Stanley S.

136

Gust Front Characteristics as Detected by Doppler Radar  

Science Journals Connector (OSTI)

Gust fronts produce low altitude wind shear that can be hazardous to aircraft operations, especially during takeoff and landing. Radar meteorologists have long been able to identify gust front signatures in Doppler radar data, but in order to use ...

Diana L. Klingle; David R. Smith; Marilyn M. Wolfson

1987-05-01T23:59:59.000Z

137

Radiation pressure on a moving body: beyond the Doppler effect  

Science Journals Connector (OSTI)

The dependence of macroscopic radiation pressure on the velocity of the object being pushed is commonly attributed to the Doppler effect. This need not be the case, and here we...

Horsley, S A R; Artoni, M; Rocca, G C La

2012-01-01T23:59:59.000Z

138

Moving interference patterns created using the angular Doppler-effect  

Science Journals Connector (OSTI)

We use the angular Doppler-effect to obtain stable frequency shifts from below one Hertz to hundreds of Hertz in the optical domain, constituting a control of 1 part in 1014. For the...

Arlt, J; MacDonald, Michael; Paterson, L; Sibbett, W; Dholakia, K; Volke-Sepulveda, K

2002-01-01T23:59:59.000Z

139

Using doppler radar images to estimate aircraft navigational heading error  

DOE Patents [OSTI]

A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.

Doerry, Armin W. (Albuquerque, NM); Jordan, Jay D. (Albuquerque, NM); Kim, Theodore J. (Albuquerque, NM)

2012-07-03T23:59:59.000Z

140

Extracting Fish and Water Velocity from Doppler Profiler Data  

E-Print Network [OSTI]

Extracting Fish and Water Velocity from Doppler Profiler Data �º Ð 1 ¸ � � �¹ � Ý�¹� � 2 1 to measure fish swimming speeds. This is possible when fish form schools that are large enough so that the multiple Doppler sonar beams are sampling the fish speeds at the same time. In situations where fish

deYoung, Brad

Note: This page contains sample records for the topic "acoustic doppler current" 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

Modeling acoustics in virtual environments using the uniform theory of diffraction  

Science Journals Connector (OSTI)

Realistic modeling of reverberant sound in 3D virtual worlds provides users with important cues for localizing sound sources and understanding spatial properties of the environment. Unfortunately, current geometric acoustic modeling systems do not accurately ...

Nicolas Tsingos; Thomas Funkhouser; Addy Ngan; Ingrid Carlbom

2001-08-01T23:59:59.000Z

142

K-distribution fading models for Bayesian estimation of an underwater acoustic channel  

E-Print Network [OSTI]

Current underwater acoustic channel estimation techniques generally apply linear MMSE estimation. This approach is optimal in a mean square error sense under the assumption that the impulse response fluctuations are well ...

Laferriere, Alison Beth

2011-01-01T23:59:59.000Z

143

NW-MILO Acoustic Data Collection  

SciTech Connect (OSTI)

There is an enduring requirement to improve our ability to detect potential threats and discriminate these from the legitimate commercial and recreational activity ongoing in the nearshore/littoral portion of the maritime domain. The Northwest Maritime Information and Littoral Operations (NW-MILO) Program at PNNL’s Coastal Security Institute in Sequim, Washington is establishing a methodology to detect and classify these threats - in part through developing a better understanding of acoustic signatures in a near-shore environment. The purpose of the acoustic data collection described here is to investigate the acoustic signatures of small vessels. The data is being recorded continuously, 24 hours a day, along with radar track data and imagery. The recording began in August 2008, and to date the data contains tens of thousands of signals from small vessels recorded in a variety of environmental conditions. The quantity and variety of this data collection, with the supporting imagery and radar track data, makes it particularly useful for the development of robust acoustic signature models and advanced algorithms for signal classification and information extraction. The underwater acoustic sensing system is part of a multi-modal sensing system that is operating near the mouth of Sequim Bay. Sequim Bay opens onto the Straight of Juan de Fuca, which contains part of the border between the U.S. and Canada. Table 1 lists the specific components used for the NW-MILO system. The acoustic sensor is a hydrophone permanently deployed at a mean depth of about 3 meters. In addition to a hydrophone, the other sensors in the system are a marine radar, an electro-optical (EO) camera and an infra-red (IR) camera. The radar is integrated with a vessel tracking system (VTS) that provides position, speed and heading information. The data from all the sensors is recorded and saved to a central server. The data has been validated in terms of its usability for characterizing the signatures of small vessels. The sampling rate of 8 kHz and low pass filtering to 2 kHz results in an alias-free signal in the frequency band that is appropriate for small vessels. Calibration was performed using a Lubell underwater speaker so that the raw data signal levels can be converted to sound pressure. Background noise is present due to a nearby pump and as a result of tidal currents. More study is needed to fully characterize the noise, but it does not pose an obstacle to using the acoustic data for the purposes of vessel detection and signature analysis. The detection range for a small vessel was estimated using the calibrated voltage response of the system and a cylindrical spreading model for transmission loss. The sound pressure of a typical vessel with an outboard motor was found to be around 140 dB mPa, and could theoretically be detected from 10 km away. In practical terms, a small vessel could reliably be detected from 3 - 5 km away. The data is archived in netCDF files, a standard scientific file format that is "self describing". This means that each data file contains the metadata - timestamps, units, origin, etc. - needed to make the data meaningful and portable. Other file formats, such as XML, are also supported. A visualization tool has been developed to view the acoustic data in the form of spectrograms, along with the coincident radar track data and camera images.

Matzner, Shari; Myers, Joshua R.; Maxwell, Adam R.; Jones, Mark E.

2010-02-17T23:59:59.000Z

144

DOPPLER SIGNATURES OF THE ATMOSPHERIC CIRCULATION ON HOT JUPITERS  

SciTech Connect (OSTI)

The meteorology of hot Jupiters has been characterized primarily with thermal measurements, but recent observations suggest the possibility of directly detecting the winds by observing the Doppler shift of spectral lines seen during transit. Motivated by these observations, we show how Doppler measurements can place powerful constraints on the meteorology. We show that the atmospheric circulation-and Doppler signature-of hot Jupiters splits into two regimes. Under weak stellar insolation, the day-night thermal forcing generates fast zonal jet streams from the interaction of atmospheric waves with the mean flow. In this regime, air along the terminator (as seen during transit) flows toward Earth in some regions and away from Earth in others, leading to a Doppler signature exhibiting superposed blueshifted and redshifted components. Under intense stellar insolation, however, the strong thermal forcing damps these planetary-scale waves, inhibiting their ability to generate jets. Strong frictional drag likewise damps these waves and inhibits jet formation. As a result, this second regime exhibits a circulation dominated by high-altitude, day-to-night airflow, leading to a predominantly blueshifted Doppler signature during transit. We present state-of-the-art circulation models including non-gray radiative transfer to quantify this regime shift and the resulting Doppler signatures; these models suggest that cool planets like GJ 436b lie in the first regime, HD 189733b is transitional, while planets hotter than HD 209458b lie in the second regime. Moreover, we show how the amplitude of the Doppler shifts constrains the strength of frictional drag in the upper atmospheres of hot Jupiters. If due to winds, the {approx}2 km s{sup -1} blueshift inferred on HD 209458b may require drag time constants as short as 10{sup 4}-10{sup 6} s, possibly the result of Lorentz-force braking on this planet's hot dayside.

Showman, Adam P.; Lewis, Nikole K. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Boulevard, Tucson, AZ 85721 (United States)] [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Boulevard, Tucson, AZ 85721 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)] [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Shabram, Megan, E-mail: showman@lpl.arizona.edu [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)] [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)

2013-01-01T23:59:59.000Z

145

Wireless technology and library acoustics  

Science Journals Connector (OSTI)

The modern library cannot function without modern technology. Printers copiers wireless computers and espresso machines all contribute to the soundscape of the typical municipal library (and many academic libraries too). While some of these noise sources are stationary and can be isolated acoustically wireless computing has transformed the acoustic experience for the typical library patron. Study carrels and desks used to define the boundaries of study and work areas in libraries and architects could design spaces accordingly. With wireless technology every space is a study space. This paper will discuss the implications of wireless technology on library acoustics. Measurement results at a variety of case study libraries will be presented.

2006-01-01T23:59:59.000Z

146

Acoustic detection of neutrinos  

Science Journals Connector (OSTI)

When high energy neutrinosinteract with nucleons in the ocean a jet of hadrons is produced which deposits thermal energy. This thermal energy is expected to produce a sonic pulse which hopefully will be sufficiently intense and directional to enable the energy and direction of incidence of the primary neutrino to be determined [Antares Parvulescu J. Acoust. Soc. Am. 61 580(A) (1977)]. This paper discusses the physical mechanism whereby the energy of the neutrino is converted into a sound pulse. A simple model will be exploited to account for the signature expected from such an event. [Work supported in part by the U. S. Naval Ocean Research and Development Activity and by the U. S. Department of Energy.

Peter J. Westervelt

1978-01-01T23:59:59.000Z

147

Acoustically invisible cylinder  

Science Journals Connector (OSTI)

Coatings of new type recently proposed by the author (Acoustical Physics 2007 vol. 53 N5 pp. 535?545) are applied to bodies of cylindrical geometry to reduce reflection or scattering of sound and thus to make them undetectable by imaging systems. Such a coating called as a coating with extended reaction represents a periodic set of small elements with coupling between the neighboring elements. Appropriate choice of the coupling parameters makes its efficiency much higher than that of commonly used coatings. In the present paper it is shown by computer simulation that a rather simple coating of this type can reduce the back?scattered pressure amplitude more than 40 dB (with respect to the rigid cylinder) practically at all frequencies. Considerable reduction of the scattered power can also be achieved in a low frequency range. The width of this range and the reduction index depend on the number of couplings introduced into the coating.

Yuri Bobrovnitskii

2008-01-01T23:59:59.000Z

148

Quasioptical design of integrated Doppler backscattering and correlation electron cyclotron emission systems on the DIII-D tokamak  

SciTech Connect (OSTI)

The quasioptical design of a new integrated Doppler backscattering (DBS) and correlation electron cyclotron emission (CECE) system is presented. The design provides for simultaneous measurements of intermediate wavenumber density and long wavelength electron temperature turbulence behavior. The Doppler backscattering technique is sensitive to plasma turbulence flow and has been utilized to determine radial electric field, geodesic acoustic modes, zonal flows, and intermediate scale (k{approx}1-6 cm{sup -1}) density turbulence. The correlation ECE system measures a second turbulent field, electron temperature fluctuations, and is sensitive to long poloidal wavelength (k{<=}1.8 cm{sup -1}). The integrated system utilizes a newly installed in-vessel focusing mirror that produces a beam waist diameter of 3.5-5 cm in the plasma depending on the frequency. A single antenna (i.e., monostatic operation) is used for both launch and receive. The DBS wavenumber is selected via an adjustable launch angle and variable probing frequency. Due to the unique system design both positive and negative wavenumbers can be obtained, with a range of low to intermediate wavenumbers possible (approximately -3 to 10 cm{sup -1}). A unique feature of the design is the ability to place the DBS and CECE measurements at the same radial and poloidal locations allowing for cross correlation studies (e.g., measurement of nT cross-phase).

Rhodes, T. L.; Peebles, W. A.; Nguyen, X.; Hillesheim, J. C.; Schmitz, L.; Wang, G. [Department of Physics and Astronomy, University of California, Los Angeles, California 90098 (United States); White, A. E. [Oak Ridge Institute for Science Education, Oak Ridge, Tennessee 37831-0117 (United States)

2010-10-15T23:59:59.000Z

149

Microsoft Word - Acoustic Sensor for Pipeline Monitoring_Revised.do  

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

LA-UR-05-6025 LA-UR-05-6025 Approved for public release; distribution is unlimited. Title: Acoustic Sensor for Pipeline Monitoring: Technology Report Author(s): Dipen N. Sinha Submitted to: Gas Technology Management Division Strategic Center for Natural Gas and Oil National Energy Technology Laboratory 2 Acoustic Sensor for Pipeline Monitoring: Technology Report Dipen Sinha Los Alamos National Laboratory July 20, 2005 Executive Summary This report presents detailed information on the effort to develop acoustic sensing technologies for natural gas pipe line monitoring. It starts with a historical evolution of the project and ends with the current status. The various technical accomplishments during this effort are pointed out. The latest technique involves the use of Lamb wave propagation in the wall of a pipe generated in a stand-off manner for defect detection. The report presents

150

Doppler effect in the oscillator radiation process in the medium  

E-Print Network [OSTI]

The purpose of this paper is to investigate the radiation process of the charged particle passing through an external periodic field in a dispersive medium. In the optical range of spectrum we will consider two cases: first, the source has not eigenfrequency, and second, the source has eigenfrequency. In the first case, when the Cherenkov radiation occurs, the non-zero eigenfrequency produces a paradox for Doppler effect. It is shown that the absence of the eigenfrequency solves the paradox known in the literature. The question whether the process is normal (i.e. hard photons are being radiated under the small angles) or anomalous depends on the law of the medium dispersion. When the source has an eigenfrequency the Doppler effects can be either normal or anomalous. In the X-ray range of the oscillator radiation spectrum we have two photons radiated under the same angle- soft and hard. In this case the radiation obeys to so-called complicated Doppler effect, i.e. in the soft photon region we have anomalous Doppler effect and in the hard photon region we have normal Doppler effect.

Lekdar Gevorgian; Valeri Vardanyan

2011-02-25T23:59:59.000Z

151

Doppler effects in resonant x-ray Raman scattering  

Science Journals Connector (OSTI)

Theory for Doppler effects in resonant x-ray Raman scattering (RXS) is presented. It is shown that the “electron” Doppler effect is important in nonradiative RXS for decay transitions between continuum nuclear states lying above the dissociation threshold, and that the averaging of the RXS cross section over molecular orientations can lead to strong non-Lorentzian broadenings of the atomiclike resonances. The Doppler effect is found to give a unique possibility to distinguish dissociating identical atoms, because different peaks correspond to atoms with opposite Doppler shifts. Spectral features of the atomiclike profile are predicted and analyzed. Strong oscillations of the RXS cross section will occur as a consequence of the interference of the Auger electrons. Due to the Doppler effect and the interference, the atomiclike profile can be associated with supernarrow spectral features, the width of which goes below the lifetime broadening and is practically independent of the spectral distribution of the incident radiation. As another consequence of the oscillations and strong anisotropy caused by the interference, we predict parity selection rules for Auger decay transitions in both bound and dissociative systems. The corresponding experiments can be realized by measurements of resonant Auger of surface adsorbed molecules and for molecules by the electron-ion coincidence technique.

Faris Gel’mukhanov; Hans Ågren; Pawe? Sa?ek

1998-04-01T23:59:59.000Z

152

Studies of Acoustic Neutrino Detection Methods with ANTARES  

E-Print Network [OSTI]

The emission of neutrinos within a wide energy range is predicted from very-high-energy phenomena in the Universe. Even the current or next-generation Cherenkov neutrino telescopes might be too small to detect the faint fluxes expected for cosmic neutrinos with energies exceeding the EeV scale. The acoustic detection method is a promising option to enlarge the discovery potential in this highest-energy regime. In a possible future deep-sea detector, the pressure waves produced in a neutrino interaction could be detected by a 100 km\\^3-sized array of acoustic sensors, even if it is sparsely instrumented with about 100 sensors/km\\^3. This article focuses on the AMADEUS set-up of acoustic sensors, which is an integral part of the ANTARES detector. The main aim of the project is a feasibility study towards a future acoustic neutrino detector. However, the experience gained with the ANTARES-AMADEUS hybrid opto-acoustic set-up can also be transferred to future very large volume optical neutrino telescopes, especial...

Graf, K

2010-01-01T23:59:59.000Z

153

Acoustic Correlates of Information Structure.  

E-Print Network [OSTI]

This paper reports three studies aimed at addressing three questions about the acoustic correlates of information structure in English: (1) do speakers mark information structure prosodically, and, to the extent they do; ...

Breen, Mara

154

The Doppler Effect in the Canal Rays in Neon  

Science Journals Connector (OSTI)

The neon spectrum in the ultraviolet between 2500A and 4000A from a canal-ray tube was examined for Doppler effects. Potentials up to 24,000 volts were applied to excite the discharge. Doppler effects were found to be present among the stronger lines in the first and second spark spectra of neon and, with only two exceptions, were absent from the arc spectrum lines. About fifty strong and faint lines showing Doppler effects were observed. The canal-ray stream consists of rapidly moving neon atoms which radiate only when in the ionized state. Neon behaves similarly to argon at high voltages and differs from most gases in that the radiation from the canal rays is almost entirely from atoms in the ionized state.

W. Romig

1931-11-01T23:59:59.000Z

155

Detection of electron velocity in graphene by Doppler effect  

Science Journals Connector (OSTI)

Abstract Electron velocity in a two-dimensional electron gas can be measured by Doppler shift. Thus, we construct the Doppler shift of light and apply it to the motion of electrons in a graphene sheet to estimate the electron velocity. Here, a laser beam with initial frequency is incident on the graphene sheet in a parallel direction, and then the frequency of the emitted light can be measured by spectroscopy after detecting the electron velocity. Then, the ratio of frequency shift from the Doppler effect is described in terms of the electron velocity, as well as the incident and the detection angle of laser beam. The thermal broadening of detected frequency as a function of velocity is also shown for different temperatures.

Heetae Kim; Chang-Soo Park; Hak Dong Cho

2014-01-01T23:59:59.000Z

156

Three-dimensional laser cooling at the Doppler limit  

E-Print Network [OSTI]

Many predictions of the theory of Doppler cooling of 2-level atoms, notably the celebrated minimum achievable temperature $T_D=\\hbar \\Gamma/2 k_B$, have never been verified in a three-dimensional geometry. Here, we show that, despite their degenerate level structure, we can use Helium-4 atoms to achieve a situation in which these predictions can be verified. We make measurements of atomic temperatures, magneto-optical trap sizes, and the sensitivity of optical molasses to a power imbalance in the laser beams, finding excellent agreement with the Doppler theory. We show that the special properties of Helium, particularly its small mass and narrow transition linewidth, prevent effective sub-Doppler cooling with red-detuned optical molasses.

Chang, Rockson; Bouton, Quentin; Fang, Yami; Klafka, Tobias; Audo, Kevin; Aspect, Alain; Westbrook, Christoph I; Clément, David

2014-01-01T23:59:59.000Z

157

Precision Measuring of Velocities via the Relativistic Doppler Effect  

E-Print Network [OSTI]

Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity in changes of the orbital velocity direction for the source. Two cases are considered: (i) a binary star; and (ii) a solitary star with the planetary companion. It is shown that, in case (i), several precision Doppler measurements employing the gas absorption cell technique would determine both the total orbital velocity and the inclination angle of the binary orbit disentangled from the peculiar velocity of the system. The necessary condition for that is the measured, at least with a modest precision, proper motion and distance to the system.

Leonid M. Ozernoy

1997-12-26T23:59:59.000Z

158

Doppler-like effect and doubtful expansion of universe  

E-Print Network [OSTI]

The distance contraction, as observed in electrical soundings over horizontally stratified earth (static system), is identified as a counterpart of Doppler shift in dynamical systems. Identification of Doppler-like effect in a stock-still systems makes it possible to give an al-ternative answer to the question about an effective cause of the Doppler shift, which sounds: the inhomogeneities. This answer opens different static as well as kinematic possibilities, which challenge established theories of expanding universe and energizing big bang.The energy propagating in stratified universe of layers exhibits a shift which could be at-tributed not only to the expansion (Hubble's theory) but alternatively to fluctuations in material properties (inhomogeneities).

Edward Szaraniec

2003-10-01T23:59:59.000Z

159

Analog circuit for controlling acoustic transducer arrays  

DOE Patents [OSTI]

A simplified ananlog circuit is presented for controlling electromechanical transducer pairs in an acoustic telemetry system. The analog circuit of this invention comprises a single electrical resistor which replaces all of the digital components in a known digital circuit. In accordance with this invention, a first transducer in a transducer pair of array is driven in series with the resistor. The voltage drop across this resistor is then amplified and used to drive the second transducer. The voltage drop across the resistor is proportional and in phase with the current to the transducer. This current is approximately 90 degrees out of phase with the driving voltage to the transducer. This phase shift replaces the digital delay required by the digital control circuit of the prior art.

Drumheller, Douglas S. (Cedar Crest, NM)

1991-01-01T23:59:59.000Z

160

Acoustical observation of the estuarine salt wedge at low-to-mid-frequencies  

Science Journals Connector (OSTI)

The estuarine environment often hosts a salt wedge the stratification of which is a function of the tide's range and speed of advance river discharge volumetric flow rate and river mouth morphology. Competing effects of temperature and salinity on sound speed control the degree of acoustic refraction occurring along an acoustic path. A field experiment was carried out in the Columbia River to test the hypothesis that the estuarine salt wedge is acoustically observable in terms of low-to-mid-frequency acoustic propagation. Linear frequency-modulated (LFM) acoustic signals in the 500–2000 Hz band were collected during the advance and retreat of the salt wedge during May 27–28 2013. Results demonstrate that the three-dimensional salt wedge front is the dominant physical feature controlling acoustic propagation in this environment: received signal energy is relatively stable under single-medium conditions before and after the passage of the salt wedge front but suffers a 10–15 dB loss as well as increased variance during salt wedge front passage due to 3D refraction and scattering. Physical parameters (i.e. temperature salinity current and turbulence) and acoustic propagation modeling corroborate and inform the acoustic observations.

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Reflective echo tomographic imaging using acoustic beams  

DOE Patents [OSTI]

An inspection system includes a plurality of acoustic beamformers, where each of the plurality of acoustic beamformers including a plurality of acoustic transmitter elements. The system also includes at least one controller configured for causing each of the plurality of acoustic beamformers to generate an acoustic beam directed to a point in a volume of interest during a first time. Based on a reflected wave intensity detected at a plurality of acoustic receiver elements, an image of the volume of interest can be generated.

Kisner, Roger; Santos-Villalobos, Hector J

2014-11-25T23:59:59.000Z

162

Anomalous Doppler effect observed during propagation of magnetostatic waves in ferromagnetic films and ferrite-dielectric-metal structures  

Science Journals Connector (OSTI)

The anomalous Doppler effect observed during propagation of magnetostatic backward volume ... ferrite-dielectric-metal structure is investigated. The effect is theoretically substantiated, and plots of Doppler fr...

Yu. A. Ignatov; A. A. Klimov; S. A. Nikitov

2010-04-01T23:59:59.000Z

163

Acoustic hemostasis: Underlying mechanisms  

Science Journals Connector (OSTI)

Cessation of hemorrhage using extrinsic interventional methods is possible with delivery of energy to bleeding tissues i.e. cauterization. High intensity focused ultrasound (HIFU) is one such method with significant advantages of delivering high levels of energy to well?defined regions of deep?seated tissues even during profuse bleeding. The physical mechanisms involved in this process include thermal and mechanical effects of HIFU leading to various biological effects. Our results using HIFU devices of 1–5 MHz and focal derated intensities of 1 000–10 000 W/cm2 in solid organs such as liver spleen and kidneys and major and minor blood vessels show that temperature of targeted tissues reaches 70–100°C within seconds with formation of microbubbles approximately 5??200 ? in size and concentration of 100 bubbles/mm3. It appears that boiling of interstitial fluids and blood and acoustic cavitation are both involved. The biological effects include coagulative necrosis mechanical disruption of tissue structure potentially leading to release of tissue factors enhancing the coagulation coagulum and thrombus formation at a wound site tissue fusion via collagen and elastin remodeling and fibrin plug formation with minimal damage of the surrounding tissues. These mechanisms appear to provide an effective and safe method of hemorrhage control. [Work supported by NIH DoD NSBRI.

Shahram Vaezy; Lawrence Crum; Steve Carter; Grant O’Keefe; Vesna Zderic; Roy Martin; Riyad Karmy?Jones

2007-01-01T23:59:59.000Z

164

Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical modeling of drizzle evolution  

E-Print Network [OSTI]

Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical I, the influence of cloud microphysics and dynamics on the shape of cloud radar Doppler spectra in warm stratiform clouds was discussed. The traditional analysis of radar Doppler moments was extended

165

Doppler Effect Associated with the Reflection of Light on a Moving Mirror  

E-Print Network [OSTI]

The Doppler Effect associated with the reflection on a moving mirror is reduced to two Doppler Effect experiments involving the incoming incident ray and the outgoing reflected ray or vice-versa. The dependence of the corresponding Doppler factors on the incidence angle on the stationary mirror.

Bernhard Rothenstein; Ioan Damian

2005-08-18T23:59:59.000Z

166

Doppler Radar Wind Profiles Iwan Holleman (holleman@knmi.nl)  

E-Print Network [OSTI]

is required before it can be presented to users or assimilated into numerical weather prediction (NWP) models Institute (KNMI), The Netherlands ABSTRACT Doppler weather radars can be employed to determine wind profiles profiles has been performed at KNMI. The verification results indicate that weather radars can provide high

Stoffelen, Ad

167

Doppler Ultrasound Driven Biomechanical Model of the Brain for  

E-Print Network [OSTI]

Doppler Ultrasound Driven Biomechanical Model of the Brain for Intraoperative Brain of the target is essential to reduce mor- bidity during brain tumor removal interventions. Yet, image-guided neu- rosurgery faces an important issue for large skull openings where brain soft-tissues can exhibit large

Paris-Sud XI, Université de

168

Dual beam translator for use in Laser Doppler anemometry  

DOE Patents [OSTI]

A method and apparatus for selectively translating the path of at least one pair of light beams in a Laser Doppler anemometry device whereby the light paths are translated in a direction parallel to the original beam paths so as to enable attainment of spacial coincidence of the two intersection volumes and permit accurate measurements of Reynolds shear stress.

Brudnoy, D.M.

1984-04-12T23:59:59.000Z

169

Generalized Doppler effect in spaces with a transport along paths  

E-Print Network [OSTI]

An analog of the classical Doppler effect is investigated in spaces (manifolds) whose tangent bundle is endowed with a transport along paths, which, in particular, can be parallel one. The obtained results are valid irrespectively to the particles mass, i.e. they hold for massless particles (e.g. photons) as well as for massive ones.

Bozhidar Z. Iliev

2004-01-19T23:59:59.000Z

170

Research on Fast-Doppler-Broadening of neutron cross sections  

SciTech Connect (OSTI)

A Fast-Doppler-Broadening method is developed in this work to broaden Continuous Energy neutron cross-sections for Monte Carlo calculations. Gauss integration algorithm and parallel computing are implemented in this method, which is unprecedented in the history of cross section processing. Compared to the traditional code (NJOY, SIGMA1, etc.), the new Fast-Doppler-Broadening method shows a remarkable speedup with keeping accuracy. The purpose of using Gauss integration is to avoid complex derivation of traditional broadening formula and heavy load of computing complementary error function that slows down the Doppler broadening process. The OpenMP environment is utilized in parallel computing which can take full advantage of modern multi-processor computers. Combination of the two can reduce processing time of main actinides (such as {sup 238}U, {sup 235}U) to an order of magnitude of 1{approx}2 seconds. This new method is fast enough to be applied to Online Doppler broadening. It can be combined or coupled with Monte Carlo transport code to solve temperature dependent problems and neutronics-thermal hydraulics coupled scheme which is a big challenge for the conventional NJOY-MCNP system. Examples are shown to determine the efficiency and relative errors compared with the NJOY results. A Godiva Benchmark is also used in order to test the ACE libraries produced by the new method. (authors)

Li, S.; Wang, K.; Yu, G. [Dept. of Engineering Physics, Tsinghua Univ., Beijing, 100084 (China)

2012-07-01T23:59:59.000Z

171

Doppler optical mixing spectroscopy in multiparticle scattering fluids  

SciTech Connect (OSTI)

We discuss the basic scheme of laser Doppler optical mixing spectroscopy for the analysis of media with multiparticle scattering. It is shown that the Rayleigh scheme, in contrast to the heterodyne and differential schemes, is insensitive to the effects of multiparticle scattering. (laser applications and other aspects of quantum electronics)

Dubnishchev, Yu N [S S Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2011-03-31T23:59:59.000Z

172

Doppler effect for an optical discharge source of shock waves  

SciTech Connect (OSTI)

The Doppler effect for a moving pulsating optical discharge producing periodic shock waves is considered. The manifestations of the effect are limited by the wave merging mechanism. The validity conditions were found for the effect in the case of a pulsating source of shock waves. (interaction of laser radiation with matter. laser plasma)

Tishchenko, V N [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2005-11-30T23:59:59.000Z

173

Spring 2011 ME706 Acoustics and Aerodynamic Sound ME706 Acoustics and Aerodynamic Sound  

E-Print Network [OSTI]

Spring 2011 ME706 Acoustics and Aerodynamic Sound ME706 Acoustics and Aerodynamic Sound Instructor-surface interaction. Spring 2011 1 ME706 Acoustics and Aerodynamic Sound #12;Spring 2011 ME706 Acoustics and Aerodynamic Sound Students are expected to: · Exhibit a level of mathematical maturity roughly equivalent

174

Lattice Boltzmann method for adiabatic acoustics  

Science Journals Connector (OSTI)

...Sauro Succi and Stefano Ubertini Lattice Boltzmann method for adiabatic acoustics...Burlington, MA 01803, USA The lattice Boltzmann method (LBM) has been proved...recovery of the full NS equations. lattice Boltzmann method|computational aero-acoustics...

2011-01-01T23:59:59.000Z

175

IN ACOUSTICS UndergraduateCourses2015  

E-Print Network [OSTI]

APPLYING SOUND KNOWLEDGE IN ACOUSTICS Acoustics UndergraduateCourses2015 #12;SOUTHA 2 #12;Reach-leadingacademicsoncoursesthataredesignedaroundyou. Wegetyoureadyfortheglobaljobsmarket,whilegivingyouagreat studentexperience. Acousticalcountriestoreducenoise REDUCING AIRCRAFT NOISE OurRollsRoyceUniversity TechnologyCentreforGas Turbine

Sóbester, András

176

Acoustic data transmission through a drill string  

DOE Patents [OSTI]

Acoustical signals are transmitted through a drill string by canceling upward moving acoustical noise and by preconditioning the data in recognition of the comb filter impedance characteristics of the drill string. 5 figs.

Drumheller, D.S.

1988-04-21T23:59:59.000Z

177

Non-Gaussianity and CMB aberration and Doppler  

SciTech Connect (OSTI)

The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a consequence, aberration and Doppler effects induce non trivial correlations between the harmonic coefficients of the observed CMB temperature maps. In this paper we investigate whether these correlations generate a bias on non-Gaussianity estimators f{sub NL}. We perform this analysis simulating a large number of temperature maps with Planck-like resolution (lmax = 2000) as different realizations of the same cosmological fiducial model (WMAP7yr). We then add to these maps aberration and Doppler effects employing a modified version of the HEALPix code. We finally evaluate a generalization of the Komatsu, Spergel and Wandelt non-Gaussianity estimator for all the simulated maps, both when peculiar velocity effects have been considered and when these phenomena have been neglected. Using the value v/c = 1.23 × 10{sup ?3} for our peculiar velocity, we found that the aberration/Doppler induced non-Gaussian signal is at most of about half of the cosmic variance ? for f{sub NL} both in a full-sky and in a cut-sky experimental configuration, for local, equilateral and orthogonal estimators. We conclude therefore that when estimating f{sub NL} it is safe to ignore aberration and Doppler effects if the primordial map is already Gaussian. More work is necessary however to assess whether a map which contains non-Gaussianity can be significantly distorted by a peculiar velocity.

Catena, Riccardo [Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Liguori, Michele; Renzi, Alessandro [INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Notari, Alessio, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de, E-mail: michele.liguori@pd.infn.it, E-mail: notari@ffn.ub.es, E-mail: arenzi@pd.infn.it [Departament de Física Fondamental i Institut de Ciéncies del Cosmos, Universitat de Barcelona, Martí i Franqués 1, 08028 Barcelona (Spain)

2013-09-01T23:59:59.000Z

178

Acoustic Logs | Open Energy Information  

Open Energy Info (EERE)

Acoustic Logs Acoustic Logs Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Acoustic Logs Details Activities (7) Areas (6) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Well Log Techniques Information Provided by Technique Lithology: determine porosity of layers Stratigraphic/Structural: map discontinuities to determine their orientation. Hydrological: Thermal: Cost Information Low-End Estimate (USD): 1.00100 centUSD 1.0e-3 kUSD 1.0e-6 MUSD 1.0e-9 TUSD / foot Median Estimate (USD): 4.62462 centUSD 0.00462 kUSD 4.62e-6 MUSD 4.62e-9 TUSD / foot High-End Estimate (USD): 16.001,600 centUSD 0.016 kUSD 1.6e-5 MUSD 1.6e-8 TUSD / foot

179

Acoustic privacy and health care.  

Science Journals Connector (OSTI)

Acoustic privacy can be differentiated into two categories: freedom from intrusive noise such as a person snoring or wheezing in the next bed traffic outside the windows carts in the hallways and footsteps on the floor above; and speech privacy—the freedom from being overheard and of overhearing others. Providing the proper acoustical environment and the protecting privacy must be a joint effort between the facility designers and hospital staff. A brief discussion of the basic requirements for speech privacy and HIPAA privacy and a quality background sound will be presented.

Neil Moiseev

2010-01-01T23:59:59.000Z

180

Acoustic repair: Recent experience with the acoustic control system (ACS) for improving acoustic conditions in two existing venues  

Science Journals Connector (OSTI)

Active acoustics systems are becoming more prevalent in architectural acoustics practice particularly in the context of repairing or improving acoustics in existing venues. Governmental policies to reduce funds and subsidies put into new facilities for the performing arts are another reason for designers to consider the use of active acoustics. This paper highlights two recent examples of such installations of ACS systems one at the Sydney Opera House Concert Hall and the other at MBCCH Winnepeg Canada. Collaboration between the system designer the musicians and the acoustics consultant will be emphasized along with techniques used to evaluate the systems' performance in the halls.

Timothy E. Gulsrud; Arthur van Maurik

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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.


181

A perspective on the CMB acoustic peak  

E-Print Network [OSTI]

CMB angular spectrum measurements suggest a flat universe. This paper clarifies the relation between geometry and the spherical harmonic index of the first acoustic peak ($\\ell_{peak}$). Numerical and analytic calculations show that $\\ell_{peak}$ is approximately a function of $\\Omega_K/\\Omega_M$ where $\\Omega_K$ and $\\Omega_M$ are the curvature ($\\Omega_K > 0$ implies an open geometry) and mass density today in units of critical density. Assuming $\\Omega_K/\\Omega_M \\ll 1$, one obtains a simple formula for $\\ell_{peak}$, the derivation of which gives another perspective on the widely-recognized $\\Omega_M$-$\\Omega_\\Lambda$ degeneracy in flat models. This formula for near-flat cosmogonies together with current angular spectrum data yields familiar parameter constraints.

T. A. Marriage

2002-03-11T23:59:59.000Z

182

Issues in acoustic field testing of quiet modular classrooms  

Science Journals Connector (OSTI)

Modular classrooms are important to American education: About 300 000 modular classrooms are currently in use by public school systems here. Good acoustical conditions for learning are no less vital for students in modular classrooms than stick?built classrooms. In an effort to promote good acoustics in modular classrooms ANSI S12 Working Group 46 is seeking to standardize acoustic field testing. Their efforts are in response to key acoustical issues of modular classrooms: Excessive noise from HVAC (heating ventilating and air conditioning) systems and poor airborne sound insulation from exterior noise sources. In a recent and notable advance an HVAC system provider reported good progress in modular HVACnoise reduction: A ducted wall mounted system was used instead of the usual free blowing system with exposed fans. HVACnoise in the unoccupied room was near the maximum 35 dB level required by ANSI S12.60. Interior noise levels were so low that efforts to confirm their values were confounded by noise contamination from exterior sources. The relatively high interior ambient noise levels were due to poor airborne sound insulation. Lessons learned from recent field testing will be discussed. Results of airborne sound insulation tests now in planning stages will be reported if available.

David Lubman; Louis C. Sutherland

2007-01-01T23:59:59.000Z

183

The influence of mesoscale eddies on shallow water acoustic propagation  

Science Journals Connector (OSTI)

Acoustic propagation measurements in 150 m depth on the Florida escarpment observe the effects of the passage of a cyclonic eddy. As the stream core of the Florida Current meanders the eddy is formed and propagates along the shelf edge. The sequence over a roughly a fortnight is as follows: ahead of the eddy warm surface water and cold bottom water are swept onto the terrace forming a steep thermocline and corresponding strong downward refracting C(z). The gradient produce intense focused RBR arrivals and the thermocline becomes a duct for internal waves to propagate shoreward. At first the internal wave energy is minimal and propagation is stable and coherent. As the internal tides attempt to propagate on shelf the sound speed field and the acoustic signals become increasingly variable. The variability reaches a crescendo as the 200 m long internal tide is blocked from propagating on to the narrower shelf and begins to break and overturn producing small?scale variability. As the eddy passes nearly iso?thermal conditions are restored along with quiescent internal wave fields and reduced signal variability. Here the effects are quantized with data from fixed?system acoustic and oceanographic measurements demonstrating that the mesoscale determines acoustic propagation conditions days in advance.

2003-01-01T23:59:59.000Z

184

Keyboard Acoustic Emanations Scott Leishman  

E-Print Network [OSTI]

of this step is the matrix. After that, the Viterbi algorithm [11] is used to infer qi, i.e. the best sequenceKeyboard Acoustic Emanations Scott Leishman ML Tea Talk - May 3rd, 2006 1 (or why you shouldn

Roweis, Sam

185

Acoustic Energy and Stellar Models  

Science Journals Connector (OSTI)

... the thermodynamic limitations of the generation of acoustic energy in stars. Quite recently, M. Schwarzschild and R. S. Richardson suggested that the transfer of energy in stars may, ... a heat engine, and this consideration does not support the views expressed by Richardson and Schwarzschild in dealing with the stellar model of red giants. In this model they suggest ...

1949-08-20T23:59:59.000Z

186

E-Print Network 3.0 - acoustic oscillation signature Sample Search...  

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

47 ACOUSTICAL EFFECTS OF INTERNAL TIDES ACOUSTICAL EFFECTS OF INTERNAL TIDES ON SHALLOW WATER Summary: ACOUSTICAL EFFECTS OF INTERNAL TIDES ACOUSTICAL EFFECTS OF INTERNAL TIDES...

187

Scattering effects at near-wall flow measurements using Doppler global velocimetry  

SciTech Connect (OSTI)

Doppler global velocimetry (DGV) is considered to be a useful optical measurement tool for acquiring flow velocity fields. Often near-wall measurements are required, which is still challenging due to errors resulting from background scattering and multiple-particle scattering. Since the magnitudes of both errors are unknown so far, they are investigated by scattering simulations and experiments. Multiple-particle scattering mainly causes a stochastic error, which can be reduced by averaging. Contrary to this, background scattering results in a relative systematic error, which is directly proportional to the ratio of the background scattered light power to the total scattered light power. After applying a correction method and optimizing the measurement arrangement, a subsonic flat plate boundary layer was successfully measured achieving a minimum wall distance of 100 {mu}m with a maximum relative error of 6%. The investigations reveal the current capabilities and perspectives of DGV for near-wall measurements.

Fischer, Andreas; Haufe, Daniel; Buettner, Lars; Czarske, Juergen

2011-07-20T23:59:59.000Z

188

Multipoint photonic doppler velocimetry using optical lens elements  

SciTech Connect (OSTI)

A probe including a fisheye lens is disclosed to measure the velocity distribution of a moving surface along many lines of sight. Laser light, directed to the surface and then reflected back from the surface, is Doppler shifted by the moving surface, collected into fisheye lens, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to an index-matching lens and eventually to a fisheye lens. The fiber array flat polished and coupled to the index-matching lens using index-matching gel. Numerous fibers in a fiber array project numerous rays through the fisheye lens which in turn project many measurement points at numerous different locations to establish surface coverage over a hemispherical shape with very little crosstalk.

Frogget, Brent Copely; Romero, Vincent Todd

2014-04-29T23:59:59.000Z

189

Prospects for Doppler cooling of three-electronic-level molecules  

SciTech Connect (OSTI)

Analogous to the extension of laser cooling techniques from two-level to three-level atoms, Doppler cooling of molecules with an intermediate electronic state is considered. In particular, we use a rate-equation approach to simulate cooling of SiO{sup +}, in which population buildup in the intermediate state is prevented by its short lifetime. We determine that Doppler cooling of SiO{sup +} can be accomplished without optically repumping from the intermediate state, at the cost of causing undesirable parity flips and rotational diffusion. Since the necessary repumping would require a large number of continuous-wave lasers, optical pulse shaping of a femtosecond laser is proposed as an attractive alternative. Other candidate three-electron-level molecules are also discussed.

Nguyen, J. H. V.; Odom, B. [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

2011-05-15T23:59:59.000Z

190

Experimental investigation of velocity biasing in laser Doppler anemometry  

E-Print Network [OSTI]

Tech University; Chair of Advisory Commettee: Dr. Gerald L. Morrison The effects of several velocity bias reduction schemes were invest- igated using a 3-D laser Doppler anemometer and counter type (burst) signal processors. Amongst these schemes... was the McLaughlin Tiederman 3-D weighting factor, time between data weighting factor, equal time interval sampling and analogue instrumentation measurements. The ana- logue instrumentation measurements were obtained from the analogue frequency outputs...

Wiedner, Brian Gregory

1988-01-01T23:59:59.000Z

191

A Fisheye Lens as a Photonic Doppler Velocimetry Probe  

SciTech Connect (OSTI)

These presentation visuals report an instrument that, by use of a fish-eye lens, generates a beat signal using fiber mixing of unshifted light with Doppler-shifted light and measures the beat frequency. Ray trace diagrams are shown to illustrate advantages and disadvantages. The authors find their instrument has a long tracking distance, and large angle coverage. Index matching eases assembly, reduces return loss and flattens the field.

Frogget, B. C.

2012-08-16T23:59:59.000Z

192

Doppler effect and frequency-shift in optics  

E-Print Network [OSTI]

A critical review of frequency-shift phenomena a la Doppler effect is presented. The importance of Fermi's theory of 1932 is pointed out, and it is argued that there exists a gap in our understanding of this phenomena at a fundamental level. Alternative mechanism in terms of photon number oscillations is suggested for polarization changing experiments. The physical reality of single photon is revisited, and a possible experimental scheme to test the alternative mechanism is suggested.

S C Tiwari

2004-10-12T23:59:59.000Z

193

Michelson interferometer null may confirm transverse Doppler Effect  

E-Print Network [OSTI]

We analyze fringe formation within Michelson-like experiments as viewed by relativistic inertial observers. Our analysis differs from previous work because we include optical misalignment of the beamsplitter of the interferometer due to the anamorphic geometry of relativistic Lorentz contraction. We conclude that inertial frame equivalence of Michelson-like experiments provide verification of the transverse Doppler Effect and exclude any model incorporating the relativistic Lorentz contraction effect.

Woodruff, Robert A

2014-01-01T23:59:59.000Z

194

Simplified, low?cost, efficient, acoustic levitation system  

Science Journals Connector (OSTI)

Recently I have improved apparatus for the acoustic levitation of a drop of one liquid in another making it practical to build for anyone who has an oscillaior and audio amplifier with response to 50 kHz a current probe an inexpensive oscilloscope and a lead zirconate titanate cylinder of the right size. This piezoelectric cylinder (1.5?in. o.d. and length 0.125?in. thickness) is epoxied near the center of a foot long piece of standard 30?mm o.d. pyrex tube. A hollow piston with o?ring seal and O. 005?in. diaphragm acts as an excellent bottom pressure?release reflector of acoustic energy as is the top air—liquid interface leading to strong acoustic standing waves at particular resonance frequencies. Optimum frequencies are determined by observing the input current to the transducer as the oscillator is tuned between 47 and 55 kHz and as liquid and piston levels are adjusted. Benzene droplets in water have been levitated with only a fraction of a watt input to the transducer. More details of this simple system will be described. [Work supported by U. S. Office of Naval Research and NSF Heat Transfer Program.

Robert E. Apfel

1977-01-01T23:59:59.000Z

195

Cylindrical acoustic levitator/concentrator  

DOE Patents [OSTI]

A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

Kaduchak, Gregory (Los Alamos, NM); Sinha, Dipen N. (Los Alamos, NM)

2002-01-01T23:59:59.000Z

196

Acoustic behavior of triple glazings  

Science Journals Connector (OSTI)

Making of triple glazings is the only way to still improve thermal performances of Insulating Glass Units. Possible ways with double glazings are already in use: increase the space between glasses use low emissivity coatings and special gas with lower thermal conductivity as argon or krypton. Specific acoustic weak point of double glazings is the resonance between the two panes which works as a mass spring mass system and coupling of eigenmodes of panes through the air (gas) cavity. These phenomena are of course still more important with triple glazings as there are two resonances. The paper will give all comparative data concerning thermal and acoustic performances and describe a way to achieve the same single number values of sound transmission loss with triple glazing that with double glazing by adding absorption in the gas cavities.

Marc Rehfeld; David Fournier

2008-01-01T23:59:59.000Z

197

Acoustic characteristics of English fricatives  

E-Print Network [OSTI]

of noise spectrum, while there are some data suggesting that /f,v/ may be distin- guished from /Y,Z/ on the basis of transition information.a!Electronic mail: jongman@ukans.edu 1252 1252J. Acoust. Soc. Am. 108 (3), Pt. 1, Sep 2000 0001...! Variance ~MHz! Skewness Kurtosis /f,v/ 5108 6.37 0.077 2.11 /T,D/ 5137 6.19 20.083 1.27 /s,z/ 6133 2.92 20.229 2.36 /S,Z/ 4229 3.38 0.693 0.421257 J. Acoust. Soc. Am., Vol. 108, No. 3, Pt. 1, Sep 2000with h2 ranging from 0.001 for skewness to 0.004 for spec...

Jongman, Allard; Wayland, Ratree; Wong, Serena

2000-09-01T23:59:59.000Z

198

Panama City 2003 Broadband Shallow?water Acoustic Coherence Experiments  

Science Journals Connector (OSTI)

In June 2003 a series of acoustic propagation experiments were conducted off the coast of Panama City Florida. The experiments were designed to measure and provide an understand of signal phase and amplitude fluctuations and signal spatial and temporal coherence over several large horizontal and vertical arrays. The propagation measurements were conducted in a water depth of 8.8m and at ranges of 70 m and 150 m. The acoustic measurements cover frequencies from 1 to 140 kHz. The propagation measurements were supported by data obtained by wave rider buoys CTD’s thermister chains and current meters. Bottom penetration data was also obtained using a buried hydrophone array. The experiments will be outlined and the data sets described.

Steve Stanic; Edgar Kennedy; Dexter Malley; Bob Brown; Roger Meredith; Robert Fisher; Howard Chandler; Richard Ray; Ralph Goodman

2004-01-01T23:59:59.000Z

199

Vertical axis wind turbine acoustics  

E-Print Network [OSTI]

Vertical Axis Wind Turbine Acoustics Charlie Pearson Corpus Christi College Cambridge University Engineering Department A thesis submitted for the degree of Doctor of Philosophy September 2013 Declaration Described in this dissertation is work... quickly to changing wind conditions, small- scale vertical axis wind turbines (VAWTs) have been proposed as an efficient solution for deployment in built up areas, where the wind is more gusty in nature. If VAWTs are erected in built up areas...

Pearson, Charlie

2014-04-08T23:59:59.000Z

200

Frustrated total internal reflection acoustic field sensor  

DOE Patents [OSTI]

A frustrated total internal reflection acoustic field sensor which allows the acquisition of the acoustic field over an entire plane, all at once. The sensor finds use in acoustic holography and acoustic diffraction tomography. For example, the sensor may be produced by a transparent plate with transparent support members tall enough to support one or more flexible membranes at an appropriate height for frustrated total internal reflection to occur. An acoustic wave causes the membrane to deflect away from its quiescent position and thus changes the amount of light that tunnels through the gap formed by the support members and into the membrane, and so changes the amount of light reflected by the membrane. The sensor(s) is illuminated by a uniform tight field, and the reflection from the sensor yields acoustic wave amplitude and phase information which can be picked up electronically or otherwise.

Kallman, Jeffrey S. (Pleasanton, CA)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

E-Print Network 3.0 - abnormal doppler enteral Sample Search...  

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

abnormal doppler enteral Page: << < 1 2 3 4 5 > >> 1 1317 September 2009, Hamburg, Germany Poster abstracts The relationship between abdominal circumference and Summary:...

202

E-Print Network 3.0 - abdominal mediante doppler Sample Search...  

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

abdominal mediante doppler Page: << < 1 2 3 4 5 > >> 1 1317 September 2009, Hamburg, Germany Poster abstracts The relationship between abdominal circumference and Summary:...

203

E-Print Network 3.0 - analyzing nexrad doppler Sample Search...  

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

using1 Gaussian Scale Mixtures in the Wavelet Domain2 Summary: Mission (TRMM) satellite and ground- based20 NEXRAD weather surveillance Doppler radars.21 1 12......

204

Effect of speckles on the depth sensitivity of laser Doppler perfusion imaging  

Science Journals Connector (OSTI)

A theoretical model is presented and experimentally validated that allows the prediction of the effect of speckles on the depth sensitivity of laser Doppler perfusion imaging. It is...

Rajan, V; Varghese, B; van Leeuwen, T G; Steenbergen, W

2007-01-01T23:59:59.000Z

205

Effect of Doppler broadening on quantitative concentration measurements with degenerate four-wave mixing spectroscopy  

Science Journals Connector (OSTI)

The effect of Doppler broadening on degenerate four-wave mixing (DFWM) signal intensities in the regime of high pump and probe laser intensities is investigated theoretically. DFWM...

Reichardt, Thomas A; Lucht, Robert P

1996-01-01T23:59:59.000Z

206

Effect of Doppler broadening on gain in an open V-type inversionless lasing system  

Science Journals Connector (OSTI)

Our study shows that for the copropagating probing and driving fields, the gain without inversion doesn't monotonously decrease or increase with the increasement of Doppler width....

Fan, Xijun; Xu, Hui; Tian, Shufen; Tong, Dianmin

2004-01-01T23:59:59.000Z

207

Rotational Doppler-effect due to selective excitation of vector-vortex field in optical fiber  

Science Journals Connector (OSTI)

Experimental demonstration of rotational Doppler-effect due to direct and simultaneous excitation of orthogonal elliptically-polarized fundamental and vortex modes in a two-mode...

Inavalli, V V G Krishna; Viswanathan, Nirmal K

2011-01-01T23:59:59.000Z

208

Active control of passive acoustic fields: Passive synthetic apertureDoppler beamforming with data from an autonomous  

E-Print Network [OSTI]

from an autonomous vehicle Gerald L. D'Spain,a Eric Terrill, C. David Chadwell, Jerome A. Smith August 2006 The maneuverability of autonomous underwater vehicles AUVs equipped with hull-mounted arrays

Smith, Jerome A.

209

Plasma Shape Effects on Geodesic Acoustic Oscillations  

SciTech Connect (OSTI)

Geodesic acoustic mode (GAM) oscillations in tokamak plasmas are known to be sensitive to the value of the safety factor q. Through its linear and nonlinear interactions with ITG turbulence it has recently been shown in direct numerical global simulations that the turbulence driven heat transport is larger when GAM oscilations of large amplitude are present, resulting in an anomalous transport scaling with the inverse plasma current. GAM dispersion relations have been derived for circular, large aspect ratio configurations, and, recently, for helical configurations. Linear simulation results are presented using the global, PIC, finite element codes GYGLES and ORB5 for the GAM frequency, damping rate and Rosenbluth-Hinton residual zonal flow for a scan in plasma elongation. It is found that CAM frequency slightly decreases, while GAM damping rate and residual zonal flows increase with elongation. Nonlinear ITG simulations using the ORB5 code show that elongation reduces heat transport and that this is related to the plasma current and not q alone.

Villard, L.; Angelino, P.; Jolliet, S.; McMillan, B. F.; Sauter, O.; Tran, T. M. [Centre de Recherches en Physique des Plasmas, Association Euratom -- Confederation Suisse, EPFL, 1015 Lausanne (Switzerland); Bottino, A. [Max-Planck Gesellschaft Institute for Plasma Physics, D-85748 Garching (Germany); Hatzky, R. [Computer Center of the IPP, D-85748 Garching (Germany); Max-Planck Gesellschaft, D-85748 Garching (Germany)

2006-11-30T23:59:59.000Z

210

Successfully merging architectural and electronic acoustical treatments  

Science Journals Connector (OSTI)

In enclosed volumes the integration of electronic acoustical components with architectural surface treatments forms a hybrid system that produces the perceived acoustical conditions. Since the underlying operating principles for electro-acoustic enhancement systems differs considerably between manufacturers the requirements for system infrastructure are not germane nor is the optimum integration of architectural treatments. As a result the nature of the work performed by the acoustical consultant changes to accommodate optimum performance of the specific “hybrid” system which may also include other forms of variable treatments.

Steve Barbar

2011-01-01T23:59:59.000Z

211

Surface acoustic wave for microfluidic applications.  

E-Print Network [OSTI]

??Surface acoustic wave-based (SAW) microfluidics attracts attention from microfluidic research community due to its simple fabrication, large force and fast, yet efficient operation. The scope… (more)

Luong, Trung Dung.

2012-01-01T23:59:59.000Z

212

Acoustic concentration of particles in fluid flow  

SciTech Connect (OSTI)

An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

Ward, Michael D. (Los Alamos, NM); Kaduchak, Gregory (Los Alamos, NM)

2010-11-23T23:59:59.000Z

213

Acoustic Concentration Of Particles In Fluid Flow  

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

in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. Available for thumbnail of...

214

Acoustic resonance for nonmetallic mine detection  

SciTech Connect (OSTI)

The feasibility of acoustic resonance for detection of plastic mines was investigated by researchers at the Oak Ridge National Laboratory`s Instrumentation and Controls Division under an internally funded program. The data reported in this paper suggest that acoustic resonance is not a practical method for mine detection. Representative small plastic anti-personnel mines were tested, and were found to not exhibit detectable acoustic resonances. Also, non-metal objects known to have strong acoustic resonances were tested with a variety of excitation techniques, and no practical non-contact method of exciting a consistently detectable resonance in a buried object was discovered. Some of the experimental data developed in this work may be useful to other researchers seeking a method to detect buried plastic mines. A number of excitation methods and their pitfalls are discussed. Excitation methods that were investigated include swept acoustic, chopped acoustic, wavelet acoustic, and mechanical shaking. Under very contrived conditions, a weak response that could be attributed to acoustic resonance was observed, but it does not appear to be practical as a mine detection feature. Transfer properties of soil were investigated. Impulse responses of several representative plastic mines were investigated. Acoustic leakage coupling, and its implications as a disruptive mechanism were investigated.

Kercel, S.W.

1998-04-01T23:59:59.000Z

215

Numerical Modeling of Acoustic Timescale Detonation Initiation Using the Adaptive  

E-Print Network [OSTI]

Numerical Modeling of Acoustic Timescale Detonation Initiation Using the Adaptive Wavelet 2008 #12;This thesis entitled: Numerical Modeling of Acoustic Timescale Detonation Initiation Using. (Ph.D.) Numerical Modeling of Acoustic Timescale Detonation Initiation Using the Adaptive Wavelet

Vasilyev, Oleg V.

216

Physiological Bases of Acoustic LRT in Nonstutterers, Mild  

E-Print Network [OSTI]

Physiological Bases of Acoustic LRT in Nonstutterers, Mild Stutterers, and Severe Stutterers* Ben C stutterers' prolonged acoustic laryngeal reaction time (LRT) values. Prephonatory kinematic data were foreperiods. Acoustic data replicated a previously observed composite stuttering severity and foreperiod

217

Holographic laser Doppler imaging of pulsatile blood flow  

E-Print Network [OSTI]

We report on wide-field imaging of pulsatile motion induced by blood flow using heterodyne holographic interferometry on the thumb of a healthy volunteer, in real-time. Optical Doppler images were measured with green laser light by a frequency-shifted Mach-Zehnder interferometer in off-axis configuration. The recorded optical signal was linked to local instantaneous out-of-plane motion of the skin at velocities of a few hundreds of microns per second, and compared to blood pulse monitored by plethysmoraphy during an occlusion-reperfusion experiment.

Bencteux, Jeffrey; Kostas, Thomas; Bayat, Sam; Atlan, Michael

2015-01-01T23:59:59.000Z

218

SIRHEN : a data reduction program for photonic Doppler velocimetry measurements.  

SciTech Connect (OSTI)

SIRHEN (Sandia InfraRed HEtrodyne aNalysis) is a program for reducing data from photonic Doppler velocimetry (PDV) measurements. SIRHEN uses the short-time Fourier transform method to extract velocity information. The program can be run in MATLAB (2008b or later) or as a Windows executable. This report describes the new Sandia InfraRed HEtrodyne aNalysis program (SIRHEN; pronounced 'siren') that has been developed for efficient and robust analysis of PDV data. The program was designed for easy use within Sandia's dynamic compression community.

Dolan, Daniel H., III; Ao, Tommy

2010-06-01T23:59:59.000Z

219

Effect of window reflections on photonic Doppler velocimetry measurements  

SciTech Connect (OSTI)

Photonic Doppler velocimetry (PDV) has rapidly become a standard diagnostic for measuring velocities in dynamic compression research. While free surface velocity measurements are fairly straightforward, complications occur when PDV is used to measure a dynamically loaded sample through a window. Fresnel reflections can severely affect the velocity and time resolution of PDV measurements, especially for low-velocity transients. Shock experiments of quartz compressed between two sapphire plates demonstrate how optical window reflections cause ringing in the extracted PDV velocity profile. Velocity ringing is significantly reduced by using either a wedge window or an antireflective coating.

Ao, T.; Dolan, D. H. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

2011-02-15T23:59:59.000Z

220

Numerical computation of doppler-broadening in the resonance domain  

SciTech Connect (OSTI)

We have implemented an accurate and fast calculation of the Doppler-broadened kernel PT(E {yields} E') for neutron elastic scattering based on a gas model. An exponential cutoff which accounts for the asymptotic behavior of the error function helps limit the range of integration while eliminating difference effects. This allows for calculating a kernel library for {sup 238}U over a very fine energy grid covering the resonance range in only a few hours in a laptop. We give an example showing the impact of {sup 238}U elastic up-scattering on the values of self shielded cross sections. (authors)

Sanchez, R. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Service d'Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France); Hewko, C. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Service d'Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France); AREVA NP/PEPDD-F, Tour Areva, Place J. Millier, 92084 La Defense (France); Santandrea, S. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Service d'Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France)

2013-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Geometric Doppler Effect: Spin-Split Dispersion of Thermal Radiation  

Science Journals Connector (OSTI)

A geometric Doppler effect manifested by a spin-split dispersion relation of thermal radiation is observed. A spin-dependent dispersion splitting was obtained in a structure consisting of a coupled thermal antenna array. The effect is due to a spin-orbit interaction resulting from the dynamics of the surface waves propagating along the structure whose local anisotropy axis is rotated in space. The observation of the spin-symmetry breaking in thermal radiation may be utilized for manipulation of spontaneous or stimulated emission.

Nir Dahan; Yuri Gorodetski; Kobi Frischwasser; Vladimir Kleiner; Erez Hasman

2010-09-21T23:59:59.000Z

222

Doppler Effect in the Slow Neutron Resonance in Rhodium  

Science Journals Connector (OSTI)

The variation in transmission of a rhodium foil to 1.26-ev neutrons has been measured as a function of foil temperature using a crystal spectrometer. A change in transmission of approximately two percent per 100-degree temperature change has been observed over a temperature range from 120°K to 860°K. After correction for instrument resolution and Doppler effect, a peak cross section of 4850±200 barns results. Comparison has been made with the theory of Bethe and Placzek as extended by Lamb.

H. H. Landon

1954-06-01T23:59:59.000Z

223

Improved Prediction of the Doppler Effect in TRISO Fuel  

SciTech Connect (OSTI)

The Doppler feedback mechanism is a major contributor to the passive safety of gas-cooled, graphite-moderated High Temperature Reactors that use fuel based on TRISO particles. It follows that the correct prediction of the magnitude and time-dependence of this feedback effect is essential to the conduct of safety analyses for these reactors. Since the effect is directly dependent on the actual temperature reached by the fuel during transients, the underlying phenomena of heat transfer and temperature rise must be correctly predicted. This paper presents an improved model for the TRISO particle and its thermal behavior during transients. The improved approach incorporates an explicit TRISO heat conduction model to better quantify the time dependence of the temperature in the various layers of the TRISO particle, including its fuel central zone. There follows a better treatment of the Doppler Effect within said fuel zone. The new model is based on a 1-D analytic solution for composite media using the Green’s function technique. The modeling improvement takes advantage of some of the physical behavior of TRISO fuel under irradiation and includes a distinctive look at the physics of the neutronic Doppler Effect. The new methodology has been implemented within the coupled R-Z nodal diffusion code CYNOD-THERMIX. The new model has been applied to the analysis of earthquakes (presented in a companion paper). In this paper, the model is applied to the control rod ejection event, as specified in the OECD PBMR-400 benchmark, but with temperature dependent thermal properties. The results obtained for this transient using the enhanced code are a considerable improvement over the predictions of the original code. The incorporation of the enhanced model shows that the Doppler Effect plays a more significant role than predicted by the original unenhanced model based on the THERMIX homogenized fuel region model. The new model shows that the overall energy generation during the rod ejection transient is significantly lower than predicted by the unenhanced model. The fuel temperature reaches a slightly higher maximum, but at no time does it approach the nominal allowable TRISO fuel temperature. The analyses with the enhanced model also show that the reactor period during the cool down is larger than previously predicted with the homogenous fuel region model.

J. Ortensi; A.M. Ougouag

2009-05-01T23:59:59.000Z

224

Laboratory measurements of acoustic scattering from a temperature and salinity gradient  

Science Journals Connector (OSTI)

Recently developed theoretical scattering models predict that acoustic scattering from temperature and salinity microstructure at high frequencies (10 kHz–1 MHz) can be significant under certain oceanographic conditions. The results of this theoretical work suggest that it may be possible to use acoustic scattering techniques in combination with the scattering models to estimate oceanographic parameters such as the dissipation rate of turbulent kinetic energy. In addition quantification of the scattering contributions from temperature and salinity microstructure can play an important role in correctly interpreting acoustic surveys of marine life since recent field data indicate that the acoustic returns from zooplankton and microstructure can be of similar strength. Acoustic backscatter from a sharp temperature and salinity gradient was measured in a tank capable of generating and sustaining a thin double?diffusive layer (1–2 cm thick) between two water masses (cold fresh residing above warm salty water). Vertical shear temperature and salinity profiles were measured during the experiment to provide input to the acoustic scattering models. Backscatter was measured at frequencies between 24 kHz and 500 kHz and as a function of range from the sharp interface as part of a program to measure the backscattering from microstructure. a)Currently at Southwest Fisheries Science Center La Jolla CA 92037.

2001-01-01T23:59:59.000Z

225

Micro-battery Development for Juvenile Salmon Acoustic Telemetry System Applications  

SciTech Connect (OSTI)

The Juvenile Salmon Acoustic Telemetry System (JSATS) project supported by the U.S. Army Corps of Engineers, Portland District, has yielded the smallest acoustic fish tag transmitter commercially available to date. In order to study even smaller fish populations and make the transmitter injectable by needles, the JSATS acoustic micro transmitter needs to be further downsized. This study focuses on the optimization of microbattery design based on Li/CFx chemistry. Through appropriate modifications, a steady high-rate pulse current with desirable life time has been achieved while the weight and volume of the battery is largely reduced. The impedance variation in as-designed microbatteries is systematically compared with that of currently used watch batteries in JSATS with an attempt to understand the intrinsic factors that control the performances of microbatteries under the real testing environments.

Chen, Honghao; Cartmell, Samuel S.; Wang, Qiang; Lozano, Terence J.; Deng, Zhiqun; Li, Huidong; Chen, Xilin; Yuan, Yong; Gross, Mark E.; Carlson, Thomas J.; Xiao, Jie

2014-01-21T23:59:59.000Z

226

Doppler disc tomography applied to low mass AGN spin  

E-Print Network [OSTI]

Doppler tomography can provide a powerful means of determining black hole spin when our view to the central regions are revealed and obscured by optically thick orbiting material, and can provide an independent estimate that does not suffer as many degeneracies as traditional methods. For low mass AGN, time-dependent obscuration is expected to leave a signature in the changing spectrum of the disc emission which extends into the soft X-ray bandpass. We create a spectral model incorporating Doppler tomography and apply it to the case of the low mass (8$\\times$10$^{5}$ M$_{\\odot}$) AGN, RX J1301.9+2747 which shows unusual timing properties in the form of short-lived flares that we argue are best explained by the orbit of a window through an optically thick wind. Modelling the phase-resolved spectrum over the course of the highest data quality flare indicates a very low spin even when we relax our constraints. This is the lowest mass AGN for which a spin has been measured and the first via this technique. We not...

Middleton, Matthew

2014-01-01T23:59:59.000Z

227

Intrinsic physical properties and Doppler boosting effects in LSI+61303  

E-Print Network [OSTI]

Our aim is to show how variable Doppler boosting of an intrinsically variable jet can explain the long-term modulation of 1667 \\pm 8 days observed in the radio emission of LSI+61303. The physical scenario is that of a conical, magnetized plasma jet having a periodical (P1) increase of relativistic particles, Nrel, at a specific orbital phase, as predicted by accretion in the eccentric orbit of LSI+61303. Jet precession (P2) changes the angle, eta, between jet axis and line of sight, thereby inducing variable Doppler boosting. The problem is defined in spherical geometry, and the optical depth through the precessing jet is calculated by taking into account that the plasma is stratified along the jet axis. The synchrotron emission of such a jet was calculated and we fitted the resulting flux density Smodel(t) to the observed flux density obtained during a 6.5-year monitoring of LSI+61303 by the Green Bank radio interferometer. Our physical model for the system LSI+61303 is not only able to reproduce the long-te...

Massi, M

2014-01-01T23:59:59.000Z

228

Acoustical Communications for Wireless Downhole Telemetry Systems  

E-Print Network [OSTI]

on this testbed in order to characterize the channel behavior are explained as well. Moreover, the large scale statistics of the acoustic waves along the pipe string are described. Results of this work indicate that acoustic waves experience a frequency- dependent...

Farraj, Abdallah

2012-08-22T23:59:59.000Z

229

ACOUSTIC FORMING FOR ENHANCED DEWATERING AND FORMATION  

SciTech Connect (OSTI)

The next generation of forming elements based on acoustic excitation to increase drainage and enhances formation both with on-line control and profiling capabilities has been investigated in this project. The system can be designed and optimized based on the fundamental experimental and computational analysis and investigation of acoustic waves in a fiber suspension flow and interaction with the forming wire.

Cyrus K Aidun

2007-11-30T23:59:59.000Z

230

Multiresolution Reproducing Kernel Particle Methods in Acoustics  

E-Print Network [OSTI]

, and reliability of dynamic analysis. This is of great importance because the noise prediction of a complexMultiresolution Reproducing Kernel Particle Methods in Acoustics R. A. Uras Reactor Engineering In the analysis of complex phenomena of acoustic systems, the computational model­ ing requires special attention

Liu, Wing Kam

231

R. White, Comsol Acoustics Introduction, 2012  

E-Print Network [OSTI]

R. White, Comsol Acoustics Introduction, © 2012 Tutorial Created in Comsol 4.3 (2012) #12;R. White Variables ­ space and time (x,y,z,t) Dependent Variables ­ unknown field (such as u) #12;R. White, Comsol (such as u) #12;R. White, Comsol Acoustics Introduction, © 2012 Finite Element Analysis (FEA / FEM) ­ 1

White, Robert D.

232

Impact of airborne Doppler wind lidar profiles on numerical simulations of a tropical cyclone  

E-Print Network [OSTI]

Click Here for Full Article Impact of airborne Doppler wind lidar profiles on numerical simulations Regional Campaign (TPARC) field experiment in 2008, an airborne Doppler wind lidar (DWL) was onboard the U measurements on the numerical simulation of Typhoon Nuri (2008) in its formation phase. With an advanced

Pu, Zhaoxia

233

Detection of femoral artery occlusion from spectral density of Doppler signals using the artificial neural network  

Science Journals Connector (OSTI)

This research is concentrated on the diagnosis of occlusion disease through the analysis of femoral artery Doppler signals with the help of Artificial Neural Network (ANN). Doppler femoral artery signals belong to occlusion patient and healthy subjects ... Keywords: Artificial neural network, Autoregressive, Back propagation algorithm, Femoral artery occlusion, Welch

Sadik Kara; Semra Kemalo?lu; Ay?egül Güven

2005-11-01T23:59:59.000Z

234

KuROS: A New Airborne Ku-Band Doppler Radar for Observation of Surfaces  

Science Journals Connector (OSTI)

This study presents the new airborne Doppler radar Ku-Band Radar for Observation of Surfaces (KuROS), which provides measurements of the normalized radar cross section ?° and of the Doppler velocity over the sea. The system includes two antennas ...

Gérard Caudal; Danièle Hauser; René Valentin; Christophe Le Gac

2014-10-01T23:59:59.000Z

235

Doppler effects in a left-handed material: a first-principle theoretical study  

E-Print Network [OSTI]

The Doppler effects for the reflected wave from a moving media are systemically analyzed in this paper. The theoretical formula for the Doppler shift in the left-handed material, which is described by Drude's dispersion model, is presented. This formula is examined by first-principles numerical experiments, which are in agreement with the theoretical results.

Sanshui Xiao; Min Qiu

2004-11-16T23:59:59.000Z

236

Acoustics of technology enabled collaborative learning environments.  

Science Journals Connector (OSTI)

Collaborative classrooms and workstations are increasingly common in higher education buildings. These spaces present unique acoustical challenges that force designers to rethink traditional concepts and solutions. In student?centered classrooms the lecturer is removed as the visual and acoustical center of attention. Instead students are seated in groups around technology enabled workstations often facing away from the lecturer and other students. Acoustical conditions must support small?group interaction classroom discussion and learning via multimedia content. Outside the classroom collaborative workstations vary greatly but typically facilitate small?group interaction around a multimedia display and/or work surface. To promote impromptu use by students these spaces are often open to highly public areas of learning commons classroom buildings and digital libraries. Traditional noise control solutions fail to isolate these spaces without compromising their spontaneous feel and function. Despite obvious acoustical challenges both space types will continue to proliferate and new acoustical solutions must be developed.

Gregory A. Coudriet; Jeffery E. Babich

2010-01-01T23:59:59.000Z

237

Preprint Collection of Charles J. Wilson Measurement of acoustic startle response in mice*  

E-Print Network [OSTI]

for measurement of acoustic startle response in mice is described. The technique utilizes a spring suspended lever of a postage stamp scale or similar spring suspension system, to which a small animal cham- ber is attached include the induction of a current in a coil by movement of a magnet attached to the animal chamber (e

Wilson, Charles J.

238

Saturation levels of heat-flux- and fast-electron-driven ion-acoustic-wave turbulence  

Science Journals Connector (OSTI)

Saturation levels of ion-acoustic-wave turbulence driven by a heat-flux and a suprathermal electron current have been calculated on the basis of perturbed-orbit theory. The levels are found to be lower than those commonly estimated from simple trapping arguments and too low to explain the thermal-flux inhibition observed in many laser-plasma experiments.

H. C. Barr and T. J. M. Boyd

1981-10-01T23:59:59.000Z

239

Collapse and revival of the Doppler-Rabi oscillations of a moving atom in a cavity  

SciTech Connect (OSTI)

Collapse and revival of the Doppler-Rabi oscillations of a two-level atom moving in a cavity electromagnetic field are analyzed. The coupled atom-field dynamics are predicted accurately by numerical calculation and approximately by using the stationary phase approximation combined with the Poisson summation formula. The collapse and revival patterns are shown to be qualitatively different in the cases of moving atom and atom at rest. In particular, quantum revivals of Doppler-Rabi oscillations occur with a period determined by the Doppler shift of the atomic transition frequency. This regime of Doppler-Rabi oscillations requires that the Rabi frequency and the Doppler shift satisfy the condition {omega}{sub R} << {omega}{sub D}. Under the inverse relation, the collapse- revival phenomenon generally does not occur. It is shown that even a small amount of atom-cavity detuning eliminates collapse-revival behavior. The analysis is performed for both coherent and thermal cavity fields.

Kozlovskii, A. V. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)], E-mail: kozlovsk@sci.lebedev.ru

2008-11-15T23:59:59.000Z

240

Effect of Shenmai Injection (?????) on ventricular diastolic function in patients with chronic heart failure: An assessment by tissue Doppler imaging  

Science Journals Connector (OSTI)

To assess the effect of Shenmai Injection (?????, ... with chronic heart failure (CHF) by tissue Doppler imaging (TDI).

Rong-guo Ma ???; Chun-xia Wang; Yin-hua Shen…

2010-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Panama City 2003 Acoustic Coherence Experiments: Environmental Characterization  

Science Journals Connector (OSTI)

During June 2003 the Naval Research Laboratory conducted a series of acoustic propagation experiments to measure both high (20 to 150 kHz) and low (1 to 10 kHz) frequency spatial and temporal coherence in very shallow water. Environmental data collected to support the acoustic measurements included water column current bottom current sea?surface wave height tide height CTD water column profiles and mid?water time series two?dimensional micro?scale seawater temperature and weather parameters. Wave periods varied from 3 to 7 seconds and wind speeds ranged from 4 to 35 knots throughout the experiment. Temperature and salinity profiles characterized periods when the water column was isovelocity and periods when the water column was stratified with a strong depth dependence of temperature and salinity. Current magnitudes were always less than 25 cm/s. Experimental geometry and methods of environmental data collection are briefly described and environmental conditions and their impact on the propagation environment are emphasized.

Roger Meredith; Robert Fisher; Steve Stanic; Edgar Kennedy; Dexter Malley; Bob Brown

2004-01-01T23:59:59.000Z

242

Selection of optimal AR spectral estimation method for internal carotid arterial Doppler signals using Cramer-Rao bound  

Science Journals Connector (OSTI)

In this study, Doppler signals recorded from internal carotid artery of 80 subjects were processed by PC-computer using autoregressive method and Doppler power spectra were obtained. The parameters of autoregressive method were estimated by different ... Keywords: AR spectral estimation method, Cramer-Rao bound, Doppler signal, Internal carotid artery, Power spectral density

Elif Derya íbeyli; ?nan Güler

2004-10-01T23:59:59.000Z

243

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer  

E-Print Network [OSTI]

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer Dept, Ontario, M3H 5T4 Paul.Joe@ec.gc.ca ABSTRACT The recent availability of sequences of 3D Doppler radial velocity datasets provides sufficient information to estimate the 3D velocity of Doppler storms. We present

Barron, John

244

PHYSICAL REVIEW E 84, 056408 (2011) Doppler measurement of implosion velocity in fast Z-pinch x-ray sources  

E-Print Network [OSTI]

black holes in galaxy merger remnants [5]. In the laboratory, the Doppler effect reveals rotation of Doppler effects in these K-shell lines thus provides unique information about the plasma motionPHYSICAL REVIEW E 84, 056408 (2011) Doppler measurement of implosion velocity in fast Z-pinch x

Starobinets, Alexander

245

R. White, Comsol Acoustics Introduction, 2/25/08  

E-Print Network [OSTI]

R. White, Comsol Acoustics Introduction, 2/25/08 #12;R. White, Comsol Acoustics Introduction, 2,y,z,t) Dependent Variables ­ unknown field (such as u) #12;R. White, Comsol Acoustics Introduction, 2/25/08 Finite ­ space and time (x,y,z,t) Dependent Variables ­ unknown field (such as u) #12;R. White, Comsol Acoustics

White, Robert D.

246

Doppler-free Yb spectroscopy with the fluorescence spot technique  

SciTech Connect (OSTI)

We demonstrate a simple technique to measure the resonant frequency of the 398.9-nm {sup 1}S{sub 0}{leftrightarrow}{sup 1}P{sub 1} transition for the different Yb isotopes. The technique, which works by observing and aligning fluorescence spots, has enabled us to measure transition frequencies and isotope shifts with an accuracy of 60 MHz. We provide wavelength measurements for the transition that differ from previously published work. Our technique also allows for the determination of Doppler-shifted transition frequencies for photoionization experiments when the atomic beam and the laser beam are not perpendicular and furthermore allows us to determine the average velocity of the atoms along the direction of the atomic beam.

Nizamani, Altaf H.; McLoughlin, James J.; Hensinger, Winfried K. [Department of Physics and Astronomy, University of Sussex, Falmer, Brighton, East-Sussex, BN1 9QH (United Kingdom)

2010-10-15T23:59:59.000Z

247

Relativistic Doppler Effect: Universal Spectra and Zeptosecond Pulses  

Science Journals Connector (OSTI)

We report on a numerical observation of the train of zeptosecond pulses produced by the reflection of a relativistically intense femtosecond laser pulse from the oscillating boundary of an overdense plasma because of the Doppler effect. These pulses promise to become unique experimental and technological tools since their length is of the order of the Bohr radius and the intensity is extremely high ?1019??W/cm2. We present the physical mechanism, analytical theory, and direct particle-in-cell simulations. We show that the harmonic spectrum is universal: the intensity of nth harmonic scales as 1/np for n<4?2, where ? is the largest ? factor of the electron fluid boundary, and p=3 and p=5/2 for the broadband and quasimonochromatic laser pulses, respectively.

S. Gordienko; A. Pukhov; O. Shorokhov; T. Baeva

2004-09-10T23:59:59.000Z

248

Doppler Effect of Nonlinear Waves and Superspirals in Oscillatory Media  

Science Journals Connector (OSTI)

Nonlinear waves emitted from a moving source are studied. A meandering spiral in a reaction-diffusion medium provides an example in which waves originate from a source exhibiting a back-and-forth movement in a radial direction. The periodic motion of the source induces a Doppler effect that causes a modulation in wavelength and amplitude of the waves (“superspiral”). Using direct simulations as well as numerical nonlinear analysis within the complex Ginzburg-Landau equation, we show that waves subject to a convective Eckhaus instability can exhibit monotonic growth or decay as well as saturation of these modulations depending on the perturbation frequency. Our findings elucidate recent experimental observations concerning superspirals and their decay to spatiotemporal chaos.

Lutz Brusch; Alessandro Torcini; Markus Bär

2003-09-05T23:59:59.000Z

249

Relativistic Doppler effect: universal spectra and zeptosecond pulses  

E-Print Network [OSTI]

We report on a numerical observation of the train of zeptosecond pulses produced by reflection of a relativistically intense femtosecond laser pulse from the oscillating boundary of an overdense plasma because of the Doppler effect. These pulses promise to become a unique experimental and technological tool since their length is of the order of the Bohr radius and the intensity is extremely high $\\propto 10^{19}$ W/cm$^2$. We present the physical mechanism, analytical theory, and direct particle-in-cell simulations. We show that the harmonic spectrum is universal: the intensity of $n$th harmonic scales as $1/n^{p}$ for $n < 4\\gamma^2$, where $\\gamma$ is the largest $\\gamma$--factor of the electron fluid boundary, $p=3$ and $p=5/2$ for the broadband and quasimonochromatic laser pulses respectively.

S. Gordienko; A. Pukhov; O. Shorokhov; T. Baeva

2004-05-10T23:59:59.000Z

250

High resolution ion Doppler spectroscopy at Prairie View Rotamak  

SciTech Connect (OSTI)

A fast ion Doppler spectroscopy (IDS) diagnostic system is installed on the Prairie View Rotamak to measure ion temperature and plasma flow. The diagnostic employs a single channel photomultiplier tube and a Jarrell-Ash 50 monochromator with a diffraction grating line density of 1180 lines/mm, which allows for first order spectra of 200-600 nm. The motorized gear of the monochromator allows spectral resolution of 0.01 nm. Equal IDS measurements are observed for various impurity emission lines of which carbon lines exhibit stronger intensities. Furthermore, the diagnostics is examined in an experiment where plasma experiences sudden disruption and quick recovery. In this case, the IDS measurements show {approx}130% increase in ion temperature. Flow measurements are shown to be consistent with plasma rotation.

Houshmandyar, Saeid; Yang Xiaokang [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Magee, Richard [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

2012-10-15T23:59:59.000Z

251

Doppler Effect of Nonlinear Waves and Superspirals in Oscillatory Media  

E-Print Network [OSTI]

Nonlinear waves emitted from a moving source are studied. A meandering spiral in a reaction-diffusion medium provides an example, where waves originate from a source exhibiting a back-and-forth movement in radial direction. The periodic motion of the source induces a Doppler effect that causes a modulation in wavelength and amplitude of the waves (``superspiral''). Using the complex Ginzburg-Landau equation, we show that waves subject to a convective Eckhaus instability can exhibit monotonous growth or decay as well as saturation of these modulations away from the source depending on the perturbation frequency. Our findings allow a consistent interpretation of recent experimental observations concerning superspirals and their decay to spatio-temporal chaos.

Lutz Brusch; Alessandro Torcini; Markus Baer

2003-02-12T23:59:59.000Z

252

22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 1 Kinetic theory of Geodesic Acoustic  

E-Print Network [OSTI]

22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 1 Kinetic theory of Geodesic Acoustic Zonca, Liu Chen and Zhiyong Qiu #12;22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 2 Chen and Zhiyong Qiu #12;22nd IAEA-FEC Kinetic theory of Geodesic Acoustic Modes: ... 3 2 Linear

Zonca, Fulvio

253

Writing magnetic patterns with surface acoustic waves  

SciTech Connect (OSTI)

A novel patterning technique that creates magnetization patterns in a continuous magnetostrictive film with surface acoustic waves is demonstrated. Patterns of 10??m wide stripes of alternating magnetization and a 3??m dot of reversed magnetization are written using standing and focusing acoustic waves, respectively. The magnetization pattern is size-tunable, erasable, and rewritable by changing the magnetic field and acoustic power. This versatility, along with its solid-state implementation (no moving parts) and electronic control, renders it as a promising technique for application in magnetic recording, magnonic signal processing, magnetic particle manipulation, and spatial magneto-optical modulation.

Li, Weiyang; Buford, Benjamin; Jander, Albrecht; Dhagat, Pallavi, E-mail: dhagat@eecs.oregonstate.edu [School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, Oregon 97331 (United States)

2014-05-07T23:59:59.000Z

254

Acoustic probing of salt using sonar  

E-Print Network [OSTI]

ACOUSTIC PROBING OF SALT USING SONAR A Thesis by KENNETH BRYAN BUTLER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE Oecember 1977 Major Subject...: Geophysics ACOUSTIC PROBING OF SALT USING SONAR A Thesis by KENNETH BRYAN BUTLER Approved as to style and content by: C airman of Com ttee ea of e r nt em er ember December 1977 ABSTRACT Acoustic Probing of Salt Using Sonar. (December 1977...

Butler, Kenneth Bryan

2012-06-07T23:59:59.000Z

255

Acoustic emission non-destructive testing of structures using source location techniques.  

SciTech Connect (OSTI)

The technology of acoustic emission (AE) testing has been advanced and used at Sandia for the past 40 years. AE has been used on structures including pressure vessels, fire bottles, wind turbines, gas wells, nuclear weapons, and solar collectors. This monograph begins with background topics in acoustics and instrumentation and then focuses on current acoustic emission technology. It covers the overall design and system setups for a test, with a wind turbine blade as the object. Test analysis is discussed with an emphasis on source location. Three test examples are presented, two on experimental wind turbine blades and one on aircraft fire extinguisher bottles. Finally, the code for a FORTRAN source location program is given as an example of a working analysis program. Throughout the document, the stress is on actual testing of real structures, not on laboratory experiments.

Beattie, Alan G.

2013-09-01T23:59:59.000Z

256

E-Print Network 3.0 - acoustic environments prediction Sample...  

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

Introduction The Acoustic Oceanographic Buoy... (AOB) is a light acoustic receiving device that incorporates acoustic and ... Source: Jesus, Srgio M. - Departamento de...

257

E-Print Network 3.0 - acoustic energy-driven fluid Sample Search...  

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

search results for: acoustic energy-driven fluid Page: << < 1 2 3 4 5 > >> 1 Acoustic Identification of Unknown Fluids Summary: Acoustic Identification of Unknown Fluids...

258

E-Print Network 3.0 - acoustic field evaluation Sample Search...  

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

nanoparticles using bulk acoustic waves Bart Raeymaekers,a Summary: nanoparticles a one dimensional acoustic field and b two-dimensional acoustic field. 014317-2 Raeymaekers......

259

Laser Doppler holographic microscopy in transmission: application to fish embryo imaging  

E-Print Network [OSTI]

We have extended Laser Doppler holographic microscopy to transmission geometry. The technique is validated with living fish embryos imaged by a modified upright bio-microcope. By varying the frequency of the holographic reference beam, and the combination of frames used to calculate the hologram, multimodal imaging has been performed. Doppler images of the blood vessels for different Doppler shifts, images where the flow direction is coded in RGB colors or movies showing blood cells individual motion have been obtained as well. The ability to select the Fourier space zone that is used to calculate the signal, makes the method quantitative.

Verrier, Nicolas; Gross, Michel

2014-01-01T23:59:59.000Z

260

Anomalous Doppler-Effect and Polariton-Mediated Cooling of Two-Level Atoms  

Science Journals Connector (OSTI)

We consider an atom moving in a near resonant laser field with its dipole strongly coupled to a resonator field mode. As compared to the standard Doppler shift, we find a substantially different and counterintuitive linear velocity dependence of the light scattering properties. The mechanical force of the laser field exhibits strong velocity selectivity at a polariton resonance, which gives rise to an enhanced friction force and Doppler cooling even in the directions perpendicular to the resonator axis. This effect allows for sub-Doppler cooling of atoms even with a nondegenerate ground state.

Peter Domokos; András Vukics; Helmut Ritsch

2004-03-11T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Current Status  

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

Current Status Current Status > Content on this page requires a newer version of Adobe Flash Player. Get Adobe Flash player July 31, 1942 The Army Corp of Engineers leases 1,025 acres of the Cook County Forest Preserve to build a research facility. November 1942 Under the direction of Enrico Fermi, a group of scientists at the University of Chicago begin building Chicago Pile-1 (CP-1). Security and secracy were essential. December 2, 1942 Enrico Fermi's team creates the world's first self-sustaining nuclear chain reaction using the CP-1 reactor under Stagg Field at the University of Chicago. CP-1 1943 The experiments under Stagg Field shut down, and the scientists move to a 19 acre section of the leased forest preserve, known as Site A. CP-1 is reconstructed and modified at Site A and renamed Chicago Pile 2 (CP-2).

262

Building Energy Software Tools Directory: Acoustics Program  

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

Acoustics Program Acoustics Program Developed to help designers accurately model the sound level reaching building tenant's ears, the Trane Acoustics Program (TAP) "projects" equipment sound power data through the surroundings (e.g., floors, ductwork, walls), to estimate the sound level that will be heard. Industry-standard calculations published by ASHRAE's 1991 Algorithms for HVAC Acoustics handbook are the basis for this estimate. In TAP, you can model the conditions of an HVAC system by choosing specific equipment and building component criteria. TAP will analyze the sound path and calculate the total effect for the enclosed space. You can continuously adjust the data and system design criteria to compare the results effortlessly. TAP will even plot presentation quality graphs of

263

Surface acoustic wave dust deposition monitor  

DOE Patents [OSTI]

A system is disclosed for using the attenuation of surface acoustic waves to monitor real time dust deposition rates on surfaces. The system includes a signal generator, a tone-burst generator/amplifier connected to a transmitting transducer for converting electrical signals into acoustic waves. These waves are transmitted through a path defining means adjacent to a layer of dust and then, in turn, transmitted to a receiving transducer for changing the attenuated acoustic wave to electrical signals. The signals representing the attenuated acoustic waves may be amplified and used in a means for analyzing the output signals to produce an output indicative of the dust deposition rates and/or values of dust in the layer. 8 figs.

Fasching, G.E.; Smith, N.S. Jr.

1988-02-12T23:59:59.000Z

264

Tiltrotor Acoustic Flight Test: Terminal Area Operations  

Science Journals Connector (OSTI)

This paper provides a comprehensive description of an acoustic flight test of the XV-15 Tiltrotor Aircraft with Advanced Technology Blades (ATB) conducted in August and September 1991 at Crows Landing, California. The purpose of this cooperative research ...

Maria O. L. Santa; Wellman J. B.; Conner D. A.; Rutledge C. K.

1992-06-01T23:59:59.000Z

265

Three-Dimensional Nonlinear Acoustical Holography  

E-Print Network [OSTI]

is validated by conducting an experiment with a compression driver and four numerical simulations. The numerical and experimental results show that holographically-projected acoustic fields match well with directly-calculated and directly-measured fields....

Niu, Yaying

2013-05-06T23:59:59.000Z

266

Multipurpose Acoustic Sensor for Downhole Fluid Monitoring  

Broader source: Energy.gov [DOE]

Novel sensor design based on acoustics. Determine in real-timeand in a single sensor packagemultiple parameters: temperature, pressure, fluid flow; and fluid properties, such as density, viscosity, fluid composition.

267

Subsurface Glider Localization Using Broadband Acoustic Sources  

E-Print Network [OSTI]

Researcher, ORE Abstract Ocean gliders are low-power, buoyancy-driven, autonomous underwater vehicles inherent in broadband ocean acoustic tomography signals, this uncertainty can be reduced by 1-2 orders

Frandsen, Jannette B.

268

Magneto?Acoustic Interaction in Mercury  

Science Journals Connector (OSTI)

The magnetically induced acoustic absorption coefficient in liquidmercury has been measured around its inverse relaxation frequency using an on?line computer and magnetic fields of up to 10 kg. The hybrid computer?operated differential measuring system took between 2560 and 25 600 experiments per run. The results agree with Anderson's predictions [J. Acoust. Soc. Amer. 25 529 (1953)]. [Work supported in part by the National Science Foundation.

Thomas D. Sachs; Gregory P. Hughes

1969-01-01T23:59:59.000Z

269

Acoustic Energy Storage in Single Bubble Sonoluminescence  

E-Print Network [OSTI]

Single bubble sonoluminescence is understood in terms of a shock focusing towards the bubble center. We present a mechanism for significantly enhancing the effect of shock focusing, arising from the storage of energy in the acoustic modes of the gas. The modes with strongest coupling are not spherically symmetric. The storage of acoustic energy gives a framework for understanding how light intensities depend so strongly on ambient gases and liquids and suggests that the light intensities of successive flashes are highly correlated.

Michael P. Brenner; Sascha Hilgenfeldt; Detlef Lohse; Rodolfo R. Rosales

1996-05-07T23:59:59.000Z

270

R. Dagan et a1.: A complementary Doppler Broadening formalism and its impact on nuclear reactor simulation R. Dagan, B. Becker and Y Danon  

E-Print Network [OSTI]

simulation R. Dagan, B. Becker and Y Danon Acomplementary Doppler Broadening formalism and its impact

Danon, Yaron

271

Parametric acoustic arrays: A Bergen view.  

Science Journals Connector (OSTI)

At the University of Bergen (UoB) Norway research activity in physical acoustics started in the mid?1960s with investigations on the parametric acoustic array (PAA). The newly appointed professor in applied mathematics Sigve Tjo/tta had some years earlier been at Brown University and was inspired by the concept at a fundamental level but also wanted experimental confirmation. No previous acoustical activity existed at UoB. The PAA project was started as a master project at Department of Physics where the main activity was in nuclear high?energy and ionospheric physics. Bellin and Beyer’s experiment served as a model. The results provided new information on the axial and directional properties of the difference frequency wave field. Inspired by this theoretical modeling continued along with further measurements. Other nonlinear effects like acoustic streaming (boundary layer density gradient) were also investigated. In 1975 a project together with SIMRAD and Norwegian Technical University resulted in a bottom penetrating PAA later commercialized as “TOPAS.” Numerical modeling based on the KZK equation resulted in the “Bergen Code ” still in use for computing nonlinear acoustic propagation problems. In later years activity at UoB has expanded to encompass linear physical acoustics of various sorts occasionally using PAA as a tool.

2009-01-01T23:59:59.000Z

272

Tunable damper for an acoustic wave guide  

DOE Patents [OSTI]

A damper for tunably damping acoustic waves in an ultrasonic waveguide is provided which may be used in a hostile environment such as a nuclear reactor. The area of the waveguide, which may be a selected size metal rod in which acoustic waves are to be damped, is wrapped, or surrounded, by a mass of stainless steel wool. The wool wrapped portion is then sandwiched between tuning plates, which may also be stainless steel, by means of clamping screws which may be adjusted to change the clamping force of the sandwiched assembly along the waveguide section. The plates are preformed along their length in a sinusoidally bent pattern with a period approximately equal to the acoustic wavelength which is to be damped. The bent pattern of the opposing plates are in phase along their length relative to their sinusoidal patterns so that as the clamping screws are tightened a bending stress is applied to the waveguide at 180/sup 0/ intervals along the damping section to oppose the acoustic wave motions in the waveguide and provide good coupling of the wool to the guide. The damper is tuned by selectively tightening the clamping screws while monitoring the amplitude of the acoustic waves launched in the waveguide. It may be selectively tuned to damp particular acoustic wave modes (torsional or extensional, for example) and/or frequencies while allowing others to pass unattenuated.

Rogers, S.C.

1982-10-21T23:59:59.000Z

273

High-frequency acoustic modes in an ionic liquid  

Science Journals Connector (OSTI)

High-frequency collective dynamics of the ionic liquid 1-hexyl-3-methylimidazolium bromide [C6C1im]Br has been investigated by molecular dynamics simulations. Time correlation functions of mass current fluctuations were calculated for several wavevectors and the dispersion curves of excitations ?(k) for longitudinal and transverse acoustic sound modes were obtained at different temperatures and pressures. Two different thermodynamic states have the same high-frequency sound velocity irrespective of the temperature provided that both have the same density. Partial time correlation functions of mass currents were calculated for the atoms belonging to the polar or the non-polar domains resulting from the heterogeneous structure of [C6C1im]Br. The partial correlation functions indicate that the polar domains are stiffer than the non-polar domains of the simulated ionic liquid.

Mauro C. C. Ribeiro

2013-01-01T23:59:59.000Z

274

Apparatus for separating particles utilizing engineered acoustic contrast capture particles  

DOE Patents [OSTI]

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

Kaduchak, Gregory (Los Alamos, NM); Ward, Michael D. (Los Alamos, NM)

2011-12-27T23:59:59.000Z

275

Apparatus for separating particles utilizing engineered acoustic contrast capture particles  

DOE Patents [OSTI]

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

Kaduchak, Gregory; Ward, Michael D

2014-10-21T23:59:59.000Z

276

E-Print Network 3.0 - airborne pulse doppler Sample Search Results  

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

pulse doppler Page: << < 1 2 3 4 5 > >> 1 JOINT DOMAIN LOCALIZEDPROCESSINGUSING MEASURED SPATIAL STEERINGVECTORS* Summary: by f , d sin OIL, f,2vLYdlPRF,where PRF is the pulse...

277

Improvement of Tornado Warnings by Doppler Radar Measurement of Mesocyclone Rotational Kinetic Energy  

Science Journals Connector (OSTI)

A significant improvement in the reliability and timeliness of tornado warnings can be achieved through quantitative measurement by Doppler radar of selected mesocyclone features. The mesocyclone, a midsize circulation found in some of the most ...

Ralph J. Donaldson Jr.; Paul R. Desrochers

1990-06-01T23:59:59.000Z

278

A Millimeter-Wavelength Dual-Polarization Doppler Radar for Cloud and Precipitation Studies  

Science Journals Connector (OSTI)

A pulse Doppler radar system operating at 35 GHz and having full polarization (linear and circular) diversity capability is described. Separate antennas are used for the transmitter and the receiver because this design approach allows better ...

F. Pasqualucci; B. W. Bartram; R. A. Kropfli; W. R. Moninger

1983-05-01T23:59:59.000Z

279

Uncertainties Associated with Combining Airborne and Ground-Based Doppler Radar Data  

Science Journals Connector (OSTI)

Observations with airborne Doppler radar can expand the area of coverage and extend the time a moving weather system can remain under observation. Also, additional analysis methods are possible with the increase in independent estimates of the ...

Peter S. Ray; David P. Jorgensen

1988-04-01T23:59:59.000Z

280

The Accuracy of Radar Estimates of Ice Terminal Fall Speed from Vertically Pointing Doppler Radar Measurements  

Science Journals Connector (OSTI)

Doppler radar measurements at different frequencies (50 and 2835 MHz) are used to characterize the terminal fall speed of hydrometeors and the vertical air motion in tropical ice clouds and to evaluate statistical methods for retrieving these two ...

Alain Protat; Christopher R. Williams

2011-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Effect of method and parameters of spectral analysis on selected indices of simulated Doppler spectra  

Science Journals Connector (OSTI)

The sensitivity of Doppler spectral indices (mean frequency, maximum frequency, ... bias of spectral estimate has a more important effect on these indices than its variance. A ... FFT method, result in increased ...

K. Kaluzynski; T. Palko

1993-05-01T23:59:59.000Z

282

Effect of Dobutamine on a Doppler Echocardiographic Index of Combined Systolic and Diastolic Performance  

Science Journals Connector (OSTI)

Dobutamine stress echocardiography has become accepted in the evaluation of cardiac functional reserve. Although the Doppler-derived index of combined systolic/diastolic myocardial ... useful for predicting left ...

K. Harada; M. Tamura; M. Toyono; K. Yasuoka

2002-12-01T23:59:59.000Z

283

Effect of microbubble contrast on intracranial blood flow velocity assessed by transcranial Doppler  

Science Journals Connector (OSTI)

Ultrasound contrast agents (UCA) salvage a considerable number of transcranial Doppler (TCD) exams which would have failed ... measured blood flow velocity (BFV). The effect of UCA continuous infusion on measured...

Nicola Logallo; Annette Fromm; Ulrike Waje-Andreassen…

2014-03-01T23:59:59.000Z

284

Doppler effects of a light source on a metamaterial slab: a rigorous Green's function approach  

Science Journals Connector (OSTI)

We apply a (rigorous) Green's function theory to study the Doppler effects of a light source placed on top of a metamaterial slab. When the receiver is in motion with the source and...

Wang, Weihua; Huang, Xueqin; Zhou, Lei; Chan, C T

2008-01-01T23:59:59.000Z

285

On the doppler effect and universal fields: an answer to Wilczy?ski  

Science Journals Connector (OSTI)

Wilczy?ski’s criticism of our derivation of the “relativistic” Doppler formula is repudiated. Some clarifications intended to facilitate the understanding are made. The main points of the aether approach are s...

M. F. Podlaha; T. Sjödin

1984-12-01T23:59:59.000Z

286

Effect of respiration on Doppler parameters of normal tricuspid porcine bioprosthetic valves  

Science Journals Connector (OSTI)

The Doppler indexes of tricuspid porcine bioprosthetic valves were evaluated in twelve patients without clinical and two-dimensional echocardiographic evidence of valve dysfunction. Peak and mean pressure grad...

Bernard Cosyns; Guy van Camp; Alain Friart…

1995-03-01T23:59:59.000Z

287

The Doppler Effect and Form of the Profile of Radiation Spectral Lines  

Science Journals Connector (OSTI)

The form of the profile for spectral lines of radiation is found using the relativistic distribution function (DF) of fluxons on velocities and exact relativistic Doppler formula for frequencies. It is shown t...

M. R. Djumaev

2001-01-01T23:59:59.000Z

288

Taking aberrations into account in experiments testing the relativistic theory of the Doppler effect  

Science Journals Connector (OSTI)

The interpretation of experimental results [L. A. Pobedonostsev, Sov. Phys. Tech. Phys. 34..., 303 (1989)] on a test of the relativistic formula for the Doppler effect and the mistaken conclusion drawn by one...6

V. O. Beklyamishev

1999-02-01T23:59:59.000Z

289

Effect of renal Doppler ultrasound on the detection of nutcracker syndrome in children with hematuria  

Science Journals Connector (OSTI)

To assess the detection rate of nutcracker syndrome in children with isolated hematuria, renal Doppler ultrasound examinations were routinely performed on 216 ... microscopic hematuria and 40 gross hematuria). Re...

Jae Il Shin; Jee Min Park; Jae Seung Lee; Myung Joon Kim

2007-05-01T23:59:59.000Z

290

Unusual Doppler effect in superfluid and nonanalyticity of4He-3He hydrodynamics  

Science Journals Connector (OSTI)

We investigate the influence of3He admixture on the Doppler shift of different sounds in superfluid4He with internal motion. This influence proves to be very strong in the whole region of the nontrivial temperatu...

Y. A. Nepomnyashchy; N. Gov; A. Mann; M. Revzen

1995-08-01T23:59:59.000Z

291

Effect of net surface charge on particle sizing and material recognition by using phase Doppler anemometry  

Science Journals Connector (OSTI)

By taking net surface charge into consideration, the scattering field of particles illuminated by dual laser beams of phase Doppler anemometry (PDA) is computed based on Mie’s...

Zhou, Jun; Xie, Li

2011-01-01T23:59:59.000Z

292

Effect of wall scattering on SNR in off-axis differential-type laser Doppler velocimetry  

Science Journals Connector (OSTI)

Though various properties and applications of laser Doppler velocimetry have been extensively studied in the ... decade, there is little discussion on the effect of light scattering from the surface of a cell on

Hiromichi Mishina; Kazuo Takahashi; Toshimitsu Asakura

1983-09-01T23:59:59.000Z

293

Wind Speeds in Two Tornadic Storms and a Tornado, Deduced from Doppler Spectra  

Science Journals Connector (OSTI)

Doppler spectra of a tornado were collected with a radar having a large unambiguous velocity range, ±91 m s?1. Thus for the first time a presentation of nonaliased spectra was possible, showing direct measurement of radial velocities. By fitting ...

Dusan Zrnic; Michael Istok

1980-12-01T23:59:59.000Z

294

Development of All-fiber Coherent Doppler Lidar to Measure Atmosphere Wind Speed  

Science Journals Connector (OSTI)

An all-fiber pulsed coherent Doppler lidar is developed to measure wind profiles. The maximum horizontal and vertical range for wind speed is 4.2km and 2km with speed accuracy of...

Liu, Jiqiao; Chen, Weibiao; Zhu, Xiaopeng

295

THE HUYGENS DOPPLER WIND EXPERIMENT Titan Winds Derived from Probe Radio Frequency Measurements  

E-Print Network [OSTI]

Doppler calibrations conducted with simulated Huygens signals uplinked from ground (Probe Relay Tests to the longer free-space propagation distance. Specific secondary science objectives of DWE include measurements

296

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

297

The effect of smoothing the Doppler radar derived wind field on perturbation pressure retrieval  

E-Print Network [OSTI]

THE EFFECT OF SMOOTHING THE DOPPLER RADAR DERIVED WIND FIELD ON PERTURBATION PRESSURE RETRIEVAL A Thesis by GEORGE PHILIP ROSSER, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1986 Major Subject: Meteorology THE EFFECT OF SMOOTHING THE DOPPLER RADAR DERIVED WIND FIELD ON PERTURBATION PRESSURE RETRIEVAL A Thesis by GEORGE PHILIP ROSSER, JR. Approved as to style and content by...

Rosser, George Philip

2012-06-07T23:59:59.000Z

298

Doppler Boosting and Deboosting Effects in the Forward Relativistic Jets of AGNs and GRBs  

E-Print Network [OSTI]

It is widely accepted that the Doppler deboosting effects exist in counter relativistic jets. However, people often neglect another important fact that both Doppler boosting and deboosting effects could happen in forward relativistic jets. Such effects might be used to explain some strange phenomena, such as the invisible gaps between the inner and outer jets of AGNs, and the rapid initial decays and re-brightening bumps in the light curves of GRBs.

Jianfeng Zhou; Yan Su

2006-10-15T23:59:59.000Z

299

Subinertial Slope-Trapped Waves in the Northeastern Gulf of Mexico  

Science Journals Connector (OSTI)

Current velocity from moored arrays of acoustic Doppler current profilers (ADCPs) deployed on the outer shelf and slope, south of Mobile Bay in the northeastern Gulf of Mexico, shows evidence of alongslope, generally westward-propagating ...

Z. R. Hallock; W. J. Teague; E. Jarosz

2009-06-01T23:59:59.000Z

300

Viscosity Effects in Acoustic Inductances  

Science Journals Connector (OSTI)

The linear acousticinductance and resistance of narrow circular tubes short compared to a wavelength have usually been represented by limiting formulas valid either for very low frequencies (viscous flow) or for relatively high frequencies (pistonlike displacement). Crandall's text gives a general mathematical development with particular stress on resistance but variation of inductance with frequency and viscosity has not been discussed generally nor has numerical reduction of mathematical results been generally available. The present paper describes quantitatively the dependence of inductance and resistance upon the general parameter radius times square root of the quantity density times frequency divided by viscosity. With increase of this parameter resistance increases while inductance diminishes from the “static” value to the limiting “high frequency” value. Experimental checks are made to ascertain whether resistance values are strongly affected by flow?transition end?effects found in hydraulics. Impedance?tube studies are made of five tube diameters from 0.0187 to 0.750 in. at 50 to 167 c/sec. Length/diameter is approximately 10 to render inductance end?corrections relatively small. Acoustic pressures are reduced until linear behavior appears. Measured resistance is generally within five percent of calculation as resistance increases to twice the “static” value. Measured inductance generally agrees with calculation within limits of the end?correction over the range of significant variation.

A. W. Nolle

1951-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Method and apparatus of spectro-acoustically enhanced ultrasonic detection for diagnostics  

DOE Patents [OSTI]

An apparatus for detecting a discontinuity in a material includes a source of electromagnetic radiation has a wavelength and an intensity sufficient to induce an enhancement in contrast between a manifestation of an acoustic property in the material and of the acoustic property in the discontinuity, as compared to when the material is not irradiated by the electromagnetic radiation. An acoustic emitter directs acoustic waves to the discontinuity in the material. The acoustic waves have a sensitivity to the acoustic property. An acoustic receiver receives the acoustic waves generated by the acoustic emitter after the acoustic waves have interacted with the material and the discontinuity. The acoustic receiver also generates a signal representative of the acoustic waves received by the acoustic receiver. A processor, in communication with the acoustic receiver and responsive to the signal generated by the acoustic receiver, is programmed to generate informational output about the discontinuity based on the signal generated by the acoustic receiver.

Vo-Dinh, Tuan (Knoxville, TN); Norton, Stephen J. (Raleigh, NC)

2001-01-01T23:59:59.000Z

302

Energy Currents  

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

7 7 Energy Currents Survey Result Our thanks to all of you who responded to our reader survey. We were pleased that many of you find this a useful publication. Your opinions will help us improve it further. The CBS News' readers include a variety of professions. 17% of respondents were consultants, 15% were engineers, 11% were teachers, 11% were scientists, 10% were program managers. The remainder included contractors, designers, marketing professionals policy analysts, journalists and others. Ranked according to highest response first, the majority of readers work in education, various levels of government, utilities, non-profit organizations, and a variety of private concerns. A surprisingly large number, 52% of the respondents, are Internet users and 23% have browsed the World Wide Web. 8% have browsed the Center's Web site

303

Energy Currents  

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

1 1 Energy Currents LBL Scientist Joins Clinton Administration Art Rosenfeld Art Rosenfeld, former head of LBL's Center for Building Science, has been named a senior advisor in the U.S. Department of Energy, serving under Assistant Secretary for Energy Efficiency and Renewable Energy Christine Ervin. His appointment began July 1. In Washington, Rosenfeld will sit on President Clinton's National Science and Technology Council. He will also serve as national spokesperson for the Administration's "Cool Communities" program and will help steer through the political process a proposed new "government-sponsored enterprise"- called EFFIE MAE for Energy Efficiency Mortgage and Loan Agency-that would guarantee loans for retrofitting energy-inefficient public buildings.

304

Effect of scattered radiation on sub-Doppler cooling  

Science Journals Connector (OSTI)

In this paper we discuss the effect of scattered radiation generated by a gas of cold atoms on the temperature of the gas. We show that by treating the reradiated field of the atoms as a fluctuating background field we can derive a master equation for a single atom where the effect of the surrounding medium is included in an effective relaxation operator. This relaxation operator is of second order in the interaction with the medium and in the binary-collision approximation can be written as the sum of two-body interactions with a correlation time equal to the natural lifetime of the atomic transition. The effect of the medium on the two most important sub-Doppler cooling mechanisms, Sisyphus and motion-induced orientation cooling, is investigated analytically in a one-dimensional model. In this we restrict ourselves to the limit of low saturation, weak background field and take the rate-equation limit for the collision operator. We find that both mechanisms are very sensitive to such a background field and that the temperature increases approximately as the number of atoms to the one-third power.

G. Hillenbrand; K. Burnett; C. J. Foot

1995-12-01T23:59:59.000Z

305

E-Print Network 3.0 - acoustically coupled oscillations Sample...  

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

Department of Mechanical Engineering PENNPENNSSTATETATE Acoustic Analysis of Gas Turbine Combustion... InstabilityAcoustic Analysis of Gas Turbine Combustion Instability ...

306

E-Print Network 3.0 - acoustically enhanced remediation Sample...  

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

PENNPENNSSTATETATE Summary: Department of Mechanical Engineering PENNPENNSSTATETATE Acoustic Analysis of Gas Turbine Combustion... InstabilityAcoustic Analysis of Gas Turbine...

307

E-Print Network 3.0 - acoustic properties Sample Search Results  

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

Department of Mechanical Engineering PENNPENNSSTATETATE Acoustic Analysis of Gas Turbine Combustion... InstabilityAcoustic Analysis of Gas Turbine Combustion Instability ...

308

E-Print Network 3.0 - acoustic wave chemical Sample Search Results  

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

Lyle N.- Department of Aerospace Engineering, Pennsylvania State University Collection: Engineering 8 Acoustic Identification of Unknown Fluids Summary: Acoustic Identification...

309

Acoustic characterization of a partially-premixed gas turbine model combustor: Syngas and hydrocarbon fuel comparisons  

Science Journals Connector (OSTI)

In this work, the acoustic behavior of a combustion instability in a gas turbine model combustor was investigated as fuel properties, air flow rates, and burner geometry were varied. The dual-swirl burner, developed at DLR Stuttgart by Meier, was operated using syngas (H2/CO), ethylene, propane, and methane. The frequency of the instability was found to vary significantly from 250 to 480 Hz. When the plenum volume and the exhaust pipe length and diameter were changed, the frequencies followed trends similar to a Helmholtz resonator. The variation of fuel type, flame speed, and air flow rate greatly altered the instability frequency and amplitude. These effects are not predicted by Helmholtz or organ tone acoustic theory. Higher frequencies were correlated with larger laminar burning velocities and higher air flow rates. The burner is a forced resonator, in which the flame oscillations couple with the flowfield to create convectively altered Helmholtz resonances. This suggests the need for an improved model of a forced Helmholtz resonator that includes flame properties. Alkane fuels displayed similar acoustic trends, but ethylene varied greatly from methane and propane. Syngas displayed different behavior than hydrocarbon fuels, even when the laminar flame speeds of the fuels were matched between ethylene and a syngas mixture. Flame characteristics such as anchoring, liftoff height, and shape appear to play a major role in the determination of instability strength and presence. With increasing hydrogen-content in the syngas-mixture, the flame transitions from a lifted to a fully anchored flame, resulting in a drastic decrease in the acoustic amplitude associated with non-resonating flames. Rayleigh indices show that flat flames create strong regions of thermo-acoustic coupling compared to axially extended V-shape flames. It is concluded that, in the current burner configuration, integrated-acoustics occur that involve a combination of Helmholtz and convective-mechanisms.

Patton M. Allison; James F. Driscoll; Matthias Ihme

2013-01-01T23:59:59.000Z

310

Dual excitation acoustic paramagnetic logging tool  

DOE Patents [OSTI]

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be performed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described. 6 figs.

Vail, W.B. III.

1989-02-14T23:59:59.000Z

311

Acoustic demonstrations for education in speech science  

Science Journals Connector (OSTI)

Acoustic demonstrations are highly effective for education in speech science. We recently developed two educational tools for acoustics. The first educational tool is a set of physical models of the human vocal tract and related models. It contains cylinder and plate?type models [T. Arai J. Phonetic Soc. Jpn. 5(2) 31–38 (2001)] a sliding three?tube model [T. Arai Acoust. Sci. Technol. to be published] lungmodels an artificial larynx and head?shaped models [T. Arai Acoust. Sci. Technol. 27(2) 111–113 (2006)]. Each model has its own advantages and if combined effectively can produce a systematic and comprehensive education in speech production from the lungs to the head. The second educational tool is ‘‘Digital Pattern Playback (DPP)’’ [T. Arai et al. Acoust. Sci. Tech. to be published] which converts a spectrographic image of a speech signal back to sound by digital signal processing. A printed spectrogram on a sheet of paper can also be converted immediately after capturing the image from a camera and we confirmed that this is more intuitive for learners than converting from an electronic image. [Work partially supported by JSPS.KAKENHI (17500603).

2006-01-01T23:59:59.000Z

312

Dual excitation acoustic paramagnetic logging tool  

DOE Patents [OSTI]

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in gelogical formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleous present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described.

Vail, III, William B. (Bothell, WA)

1989-01-01T23:59:59.000Z

313

History of American acoustics—Introductory comments  

Science Journals Connector (OSTI)

The history of acoustics has been illuminated by the efforts in recent years of R. Bruce Lindsay and so this Bicentennial Session is being held in his honor. In addition certain numerological factors spurred our efforts in this Bicentennial Year 1976. It was just one hundred years ago that A. G. Bell's invention—the first practical telephone—was exhibited at the 1876 Centennial Exposition in Philadelphia. A year later in 1877 the first edition of Rayleigh's Theory of Sound appeared. The conjunction of these two events eventually had a powerful influence on the development of acoustics. The invited speakers will in the papers which follow endeavor to describe all of the significant advances made by Americans to technical acoustics. Apparently it all began with Joseph Henry's efforts to solve a problem in auditorium acoustics. At the brink of World War II acoustics was invaded by a host of scientists and engineers. During the period 1941–45 and in the post war years frontiers were breached in almost every direction at such a rate that description of the advances made cannot be done here. And so most of our speakers will bring their histories up only to about the year 1940.

Richard K. Cook

1976-01-01T23:59:59.000Z

314

Guided wave acoustic monitoring of corrosion in recovery boiler tubing  

SciTech Connect (OSTI)

Corrosion of tubing used in black-liquor recovery boilers is a major concern in all pulp and paper mills. Extensive corrosion in recovery boiler tubes can result in a significant safety and environmental hazard. Considerable plant resources are expended to inspect recovery boiler tubing. Currently, visual and ultrasonic inspections are primarily used during the annual maintenance shutdown to monitor corrosion rates and cracking of tubing. This Department of Energy, Office of Industrial Technologies project is developing guided acoustic waves for use on recovery boiler tubing. The feature of this acoustic technique is its cost-effectiveness in inspecting long lengths of tubes from a single inspection point. A piezoelectric or electromagnetic transducer induces guided waves into the tubes. The transducer detects fireside defects from the coldside or fireside of the tube. Cracking and thinning on recovery boiler tubes have been detected with this technique in both laboratory and field applications. This technique appears very promising for recovery boiler tube application, potentially expediting annual inspection of tube integrity.

Quarry, M J; Chinn, D J

2004-02-19T23:59:59.000Z

315

Acoustic measurement of the Deepwater Horizon Macondo well flow rate  

E-Print Network [OSTI]

On May 31, 2010, a direct acoustic measurement method was used to quantify fluid leakage rate from the Deepwater Horizon Macondo well prior to removal of its broken riser. This method utilized an acoustic imaging sonar and ...

Camilli, Richard

316

Laser-excited acoustic oscillations in silver and bismuth nanowires  

E-Print Network [OSTI]

Coherent acoustic oscillations in Bi and Ag nanowire samples were studied with a femtosecond pump-probe technique and detection of the scattered light. The observed optical and acoustic properties reflect the nanostructure of these materials...

Jerebtsov, Sergey N.; Kolomenskii, Alexandre A.; Liu, Haidong; Zhang, Hong; Ye, Zuxin; Luo, Zhiping; Wu, Wenhao; Paulus, Gerhard G.; Schuessler, Hans A.

2007-01-01T23:59:59.000Z

317

Spatiotemporal processing and time-reversal for underwater acoustic communications  

E-Print Network [OSTI]

High-rate underwater acoustic communication can be achieved using transmitter/receiver arrays. Underwater acoustic channels can be characterized as rapidly time-varying systems that suffer severe Inter Symbol Interferences ...

Wang, Daniel Y

2005-01-01T23:59:59.000Z

318

13.853 Computational Ocean Acoustics, Spring 2003  

E-Print Network [OSTI]

Wave equations for fluid and visco-elastic media. Wave-theory formulations of acoustic source radiation and seismo-acoustic propagation in stratified ocean waveguides. Wavenumber Integration and Normal Mode methods for ...

Schmidt, Henrik

319

Achieving acoustical satisfaction in a green building  

Science Journals Connector (OSTI)

The Carnegie Institution’s Global Ecology Research Center at Stanford University has garnered many accolades including the AIA’s Excellence in SustainabilityAward. This building incorporates many ‘‘green’’ and energy?saving design features mechanical systems and materials. The occupants of this facility have given it high marks in U.C. Berkeley’s Center for the Built Environment’s (CBE) survey of buildings. Staff at the Global Ecology Research Center are shown to be more satisfied with their acoustical environment than occupants of other green buildings surveyed by CBE. Measured acoustical data for speech privacy in open plan and enclosed conference rooms will be presented along with descriptions of acoustical design attributes for the building.

2006-01-01T23:59:59.000Z

320

Acoustical design issues for library facility planners  

Science Journals Connector (OSTI)

Acting under the provisions of the Library Services and Technology Act the U.S. Institute of Museum and Library Services retained Charles M. Salter Associates Inc. to provide a document explaining acoustical and audio/visual requirements for libraries to library planners architects and lay people. Acoustical design issues for libraries discussed on the website include site noise considerations noise standards for each use space room acoustics considerations sound isolation between various use spaces vibration control for mechanical equipment and audio/visual system considerations. The completed document forms a part of the Libris Design library facility planning information system which includes a website with recent information on facility planning topics and a database of recently constructed California public libraries.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

Developing criteria for identifying acoustical defects  

Science Journals Connector (OSTI)

In a construction defect lawsuit of a multifamily residential project the determination of whether a defect exists often hinges on the criteria applied. For many acoustical items such as plumbing and HVAC noise there are no code requirements but a number of guidelines and recommendations. For items such as noise from traffic or airborne and impact sound isolation between units minimum code requirements exist but often a more stringent standard is applied. How does an expert decide when it is appropriate to apply an acoustical standard that is beyond that required by building codes? Project drawings marketing materials homeowner regulations and other documents can provide indications of the intent and promise of the project as it relates to acoustical issues. The process is discussed with examples from recent cases.

John LoVerde; David W. Dong

2013-01-01T23:59:59.000Z

322

Active micromixer using surface acoustic wave streaming  

DOE Patents [OSTI]

An active micromixer uses a surface acoustic wave, preferably a Rayleigh wave, propagating on a piezoelectric substrate to induce acoustic streaming in a fluid in a microfluidic channel. The surface acoustic wave can be generated by applying an RF excitation signal to at least one interdigital transducer on the piezoelectric substrate. The active micromixer can rapidly mix quiescent fluids or laminar streams in low Reynolds number flows. The active micromixer has no moving parts (other than the SAW transducer) and is, therefore, more reliable, less damaging to sensitive fluids, and less susceptible to fouling and channel clogging than other types of active and passive micromixers. The active micromixer is adaptable to a wide range of geometries, can be easily fabricated, and can be integrated in a microfluidic system, reducing dead volume. Finally, the active micromixer has on-demand on/off mixing capability and can be operated at low power.

Branch; Darren W. (Albuquerque, NM), Meyer; Grant D. (Ithaca, NY), Craighead; Harold G. (Ithaca, NY)

2011-05-17T23:59:59.000Z

323

Numerical Modeling of Acoustic Timescale Detonation J.D. Regele  

E-Print Network [OSTI]

Numerical Modeling of Acoustic Timescale Detonation Initiation J.D. Regele , D.R. Kassoy and O to perform one and two-dimensional simulations of acoustic timescale detonation initiation using thermal overdriven detonation wave that decays to a steady-state CJ wave. A 1-D parametric study of acoustic

Vasilyev, Oleg V.

324

Support minimized inversion of acoustic and elastic wave scattering  

SciTech Connect (OSTI)

This report discusses the following topics on support minimized inversion of acoustic and elastic wave scattering: Minimum support inversion; forward modelling of elastodynamic wave scattering; minimum support linearized acoustic inversion; support minimized nonlinear acoustic inversion without absolute phase; and support minimized nonlinear elastic inversion.

Safaeinili, A.

1994-04-24T23:59:59.000Z

325

The Impact of Civil Rights Legislation on Classroom Acoustics  

E-Print Network [OSTI]

.................................................................................................................... 30 v Abbreviations ADA American with Disabilities Act ADAAG Americans With Disabilities Act Accessibility Guidelines ANSI American National Standards Institute ARI Air-Conditioning and Refrigeration Institute ASA Acoustical... classroom acoustics standards for subsequent inclusion in the Americans With Disabilities Act Access Guidelines (ADAAG), and to reference classroom acoustics in the International Building Code (IBC). However, opposition from the modular classroom and HVAC...

Teel, Jeffrey

2005-12-16T23:59:59.000Z

326

Acoustic characteristics of clearly spoken English fricatives  

E-Print Network [OSTI]

Acoustic characteristics of clearly spoken English fricatives renc n Fr cept em exam s to aref fric ed b gram wn effe e co h w by effo y an and 21/1 Deliberately clarified speech has been seen to yield intelligi- 2003; Krause and Braida, 2004... situations.3962 J. Acoust. Soc. Am. 125 #2;6#1;, June 2009 0001-4966/2009/12 ution subject to ASA license or copyright; see http://acousticalsociety.org/ce, Kansas 66044 ancisco, California 94104 ed 1 September 2008#2; to be understood more easily...

Maniwa, Kazumi; Jongman, Allard

2009-06-01T23:59:59.000Z

327

Measuring baryon acoustic oscillations with future SKA surveys  

E-Print Network [OSTI]

The imprint of baryon acoustic oscillations (BAO) in large-scale structure can be used as a standard ruler for mapping out the cosmic expansion history, and hence for testing cosmological models. In this article we briefly describe the scientific background to the BAO technique, and forecast the potential of the Phase 1 and 2 SKA telescopes to perform BAO surveys using both galaxy catalogues and intensity mapping, assessing their competitiveness with current and future optical galaxy surveys. We find that a 25,000 sq. deg. intensity mapping survey on a Phase 1 array will preferentially constrain the radial BAO, providing a highly competitive 2% constraint on the expansion rate at z ~ 2. A 30,000 sq. deg. galaxy redshift survey on SKA2 will outperform all other planned experiments for z < 1.4.

Bull, Philip; Raccanelli, Alvise; Blake, Chris; Ferreira, Pedro G; Santos, Mario G; Schwarz, Dominik J

2015-01-01T23:59:59.000Z

328

Advances in biomedical applications of time reversal acoustic focusing of ultrasound  

Science Journals Connector (OSTI)

Time reversal acoustics (TRA) is one of the most efficient methods of ultrasound focusing in heterogeneous composite biological media especially inside reverberating cavities such as the skull. In this talk we will overview several recently developed therapeutic applications of TRA focusing of ultrasound including enhanced drug delivery to brain tumors generation of focal regions of complex shape tailored to the geometry of the target lesion and TRA dynamic focusing that allows to maintain the constant acoustic intensity in the focus regardless the variation of acoustical parameters of the media. We are currently developing several new medical applications of TRA such as remote charging of batteries in internal implants and leadless energizing deep brain stimulators which are based on the possibility to remotely generate an electrical signal in tissue using TRA principles. These applications employ a TRA focusing system with wireless electromagnetic feedback from the tiny implanted piezotransducer acting as a beacon. The acoustic energy is accurately focused at the piezotransducer generating required electrical signal while providing minimum exposure of surrounding tissues to ultrasound energy. Possibility of remote generation of electrical signals in tissue with amplitudes reaching tens of volts was demonstrated. [Work supported by NIH R21 CA164935-01.

Alexander Sutin

2013-01-01T23:59:59.000Z

329

Experimental observation of acoustic sub-harmonic diffraction by a grating  

SciTech Connect (OSTI)

A diffraction grating is a spatial filter causing sound waves or optical waves to reflect in directions determined by the frequency of the waves and the period of the grating. The classical grating equation is the governing principle that has successfully described the diffraction phenomena caused by gratings. However, in this work, we show experimental observation of the so-called sub-harmonic diffraction in acoustics that cannot be explained by the classical grating equation. Experiments indicate two physical phenomena causing the effect: internal scattering effects within the corrugation causing a phase shift and nonlinear acoustic effects generating new frequencies. This discovery expands our current understanding of the diffraction phenomenon, and it also makes it possible to better design spatial diffraction spectra, such as a rainbow effect in optics with a more complicated color spectrum than a traditional rainbow. The discovery reveals also a possibly new technique to study nonlinear acoustics by exploitation of the natural spatial filtering effect inherent to an acoustic diffraction grating.

Liu, Jingfei, E-mail: benjamin.jf.liu@gatech.edu; Declercq, Nico F., E-mail: declercqdepatin@gatech.edu [Laboratory for Ultrasonic Nondestructive Evaluation “LUNE,” Georgia Tech Lorraine, Georgia Tech-CNRS UMI2958, Georgia Institute of Technology, 2, rue Marconi, Metz 57070 (France)

2014-06-28T23:59:59.000Z

330

High?frequency acoustic propagation measurements during solitary wave events on the eastern continental shelf edge  

Science Journals Connector (OSTI)

High?frequency environmental acoustics studies were conducted during July 1993 on the continental shelf edge east of New Jersey. Internal solitons previously observed in this region near the shelf/slope front propagate in packets usually in the summer seasonal thermocline and have been associated with anomalous low frequency sound propagation. Acoustic pings were collected using a towed sled instrumented with sonar arrays. Synoptic measurements to characterize the solitons including sound velocity profiles sampled every 10 min over a tidal cycle and moored data including current temperature and conductivity. Acoustic measurements were taken during sled tows parallel to the bottom bathymetry normal to the propagation direction over a region determined from bottom cores to be nearly homogeneous fine sand. Measurements were taken using the sled as a source for backscattermeasurements and also using moored acoustic sources and the sled based transducers as receivers. The observed solitons had amplitudes of approximately 10 m and periods of several minutes. The backscatter variability during soliton events was observed to approximately 10–20 dB and will be compared to modeled predictions based on environmental data.

Edward R. Levine; Richard R. Shell; Michael R. Medeiros

1994-01-01T23:59:59.000Z

331

Technical Note: Improved implementation of doppler broadening in MCNP5  

SciTech Connect (OSTI)

Purpose: Incoherent scattering has a substantial effect on spectroscopic measurements and simulations. Many general-purpose Monte Carlo codes include models that account for the effects of bound electrons on incoherent scattering, including Doppler broadening (DB). This work investigates the DB model used in the Monte Carlo N-particle transport code (MCNP5). Methods: Simulations were run with three versions of MCNP5: v1.51, v1.60, and a modified form of v1.60 (v1.60m). All simulations used the MCPLIB04 photon data library, which presents the electron subshell data for incoherent scattering in the form of a probability density function. In v1.60m, the source code was altered to sample the electron subshell from a cumulative density function instead. Each version of the code was tested using an identical set of simulations that investigated DB in a slab of silicon at scattering angles of 15 Degree-Sign , 30 Degree-Sign , and 45 Degree-Sign . For each angle, simulations were run for multiple energies between 200 keV and 800 keV. The spectrum of singly-scattered photons at the exit of the slab was scored. Spectra were analytically calculated for comparison. Results: In v1.51, DB was modeled for incident photon energies below 760 keV, 384 keV, and 260 keV at scattering angles of 15 Degree-Sign , 30 Degree-Sign , and 45 Degree-Sign , respectively. Above these energy thresholds, v1.51 did not model DB. The spectra calculated using v1.60 and v1.60m exhibited DB for all energy-angle combinations; however, v1.60m, exhibited more energy broadening than did v1.60. The spectra calculated with v1.60m agreed with the analytical calculations. Conclusions: MCNP5 v1.51 and v1.60 model partial broadening when used with the MCPLIB04 data library. MCNP5 v1.60m models DB more accurately due to the form of the electron subshell data. In response to these results, Los Alamos National Laboratory has released a new photon data library, MCPLIB84, that presents the electron subshell data in cumulative distribution form. MCNP5 v1.60 should be used with this library when incoherent scattering has a significant impact on simulation results.

Bartol, Laura J.; DeWerd, Larry A. [University of Wisconsin-Madison, Department of Medical Physics, Madison, Wisconsin 53705 (United States)

2012-09-15T23:59:59.000Z

332

Acoustically enhanced remediation, Phase 2: Technology scaling  

SciTech Connect (OSTI)

Weiss Associates is conducting the following three phase program investigating the in-situ application of acoustically enhanced remediation (AER) of contaminated unconsolidated soil and ground water under both saturated and unsaturated conditions: Phase I-- laboratory scale parametric investigation; Phase II--technology Scaling; and Phase III--large scale field tests. AER addresses the need for NAPL (either lighter or denser than water: LNAPL or DNAPL, respectively) in high and low permeability sediments, and the remediation of other types of subsurface contaminants (e.g., metals, radionuclides) in low permeability soils. This program has been placed in the U.S. Department of Energy`s (DOE`s) DNAPL product. Phase I indicated that AER could be used to effectively remediate NAPL in high permeability soil, and that removal of NAPL from low permeability soil could be increased since the water flux through these soils was significantly increased. Phase II, Technology Scaling, the subject of this paper, focused on (1) evaluating the characteristics of an AER field deployment system, (2) developing DNAPL flow and transport performance data under acoustic excitation, (3) predicting the effect of acoustic remediation in three-dimensional unconsolidated hydrogeologic conditions, (4) conducting an engineering analysis of acoustical sources, and (5) identifying candidate field site(s) for large-scale field testing of the technology.

Iovenitti, J.L.; Hill, D.G. [Weiss Associates, Emeryville, CA (United States); Rynne, T.M.; Spadaro, J.F.; Hutchinson, W. [Scientific Applications and Research Associates, Inc., Huntington Beach, CA (United States); Illangasakere, T. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental, and Architectural Engineering

1996-12-31T23:59:59.000Z

333

Thermoacoustic Stirling Engine --An acoustic amplifier  

E-Print Network [OSTI]

National Laboratory Condensed Matter and Thermal Physics Group MS K764, Los Alamos, NM 87545 backhaus) efficiencies 6" 24 " 72 " Acoustic power: 100 W 1 kW 50 kW T.A. efficiency: 23% 30% 25% All-metal bonded PZT stacks Metal joints, rather than epoxy joints, between PZT elements allow stacks to generate high power

Lee, Dongwon

334

New acoustic devices for breathing investigations  

Science Journals Connector (OSTI)

The problem of spirometry control in medicine and medical engineering still remains urgent. The necessity of getting more and more information from spirometry investigations imposes more and more stringent requirements for spirometers, volumeters and ... Keywords: acoustic waves propagation, air-gas velocity, breathing, flow rate, measurement, moving in channel media, spiroanalyser

Semyon Shkundin

2009-08-01T23:59:59.000Z

335

Acoustics of modular construction—Industry overview  

Science Journals Connector (OSTI)

This session will provide an overview of the issues and efforts impacting the commercial modular construction industry throughout North America with particular focus on acoustics in relocatable classrooms. The Modular Building Institute is the international nonprofit trade association representing manufacturers and dealers of commercial modular facilites both temporary and permanent serving educational health care retail industrial military and multi?family markets.

Thomas E. Hardiman

2007-01-01T23:59:59.000Z

336

Ocean Climate Change: Comparison of Acoustic  

E-Print Network [OSTI]

Ocean Climate Change: Comparison of Acoustic Tomography, Satellite Altimetry, and Modeling The ATOC to thermal expansion. Interpreting climate change signals from fluctuations in sea level is therefore in the advective heat flux. Changes in oceanic heat storage are a major expected element of future climate shifts

Frandsen, Jannette B.

337

Acoustic-emission monitoring during hydraulic fracturing  

SciTech Connect (OSTI)

This paper reports that microseismic events or acoustic emissions associated with hydraulic fracturing are recorded with a borehole seismic tool in a deviated well during multirate injection, shut-in, and flowback. The event locations indicate that fracture orientation, length, and height are compatible with regional stress directions and estimates of the fracture size that are based on pressure decline.

Stewart, L. (Schlumberger-Doll Research (US)); Cassell, B.R. (Schlumberger Wireline Services (US)); Bol, G.M. (Nederlanse Aardolie Mij. B.V. (NL))

1992-06-01T23:59:59.000Z

338

Research equipment: Surface Acoustic Wave (SAW) devices  

E-Print Network [OSTI]

of the acoustic wave. More specifically, the equipment consists of: i. HP 4195A (10Hz-500MHz) ii. HP 8753ES (30kHz measurements on many SAW devices iii. Agilent E5061A (300kHz-1.5GHz) http Scientific Corp.): Atmospheric plasma etching, for surface cleaning, surface treatment and activation

Gizeli, Electra

339

Title Slide "The broadband acoustic output of  

E-Print Network [OSTI]

Title Slide "The broadband acoustic output of marine seismic airgun sources" Les Hatton CISM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . #12;Seismic sources ­ marine airguns Introduction Modelling Marine Life Impact Where next Overview #12 Normal speed surface movie of airgun firing Courtesy IO limited #12;Seismic sources ­ marine airguns

Hatton, Les

340

Condition Monitoring and Management from Acoustic  

E-Print Network [OSTI]

is about condition monitoring of large diesel engines from acoustic emission signals. The experiments have been focused on a specific and severe fault called scuffing. The fault is generally assumed to arise of this work is the analysis of the angular position changes of the engine related events such as fuel

Note: This page contains sample records for the topic "acoustic doppler current" 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

Acoustic Lexemes for Organizing Internet Audio  

E-Print Network [OSTI]

Acoustic Lexemes for Organizing Internet Audio Michael A. Casey In this article, a method is proposed for automatic fine-scale audio description that draws inspiration from ontological sound automation of audio description at the level of sound objects for indexing and retrieving sound segments

Casey, Michael

342

ElectroAcoustical HansGerd Berns  

E-Print Network [OSTI]

. DUMAND will be deployed at 4800 m depth in the Pacific Ocean approximately 25 km off the west coast at DUMAND Site : : : : : : : : : : : : : : : : : : : : 46 6.4 First Acoustical Survey Operations at DUMAND : : : : : : : : : : : : : : : 50 7.2 Transducer: ITC­3217 Modified : : : : : : : : : : : : : : : : : : : : 51 7.3 Power Amplifier

Berns, Hans-Gerd

343

Upgrading secret military facilities—What is more important, acoustic design standards or acoustical performance?  

Science Journals Connector (OSTI)

The U.S. Department of Defense has developed acoustical performance standards that are to be achieved in the design and construction of meeting and conference rooms where sensitive and secret information will be discussed. These performance standards rely on published acoustical industry design data which are readily available. The intention of these standards is to prevent sensitive and secret information from being heard understood or otherwise obtained by persons or devices that are not authorized to have access to such information. This paper presents design and field performance test results for new and renovated secret rooms that initially passed the acoustical design criteria and acoustical standard field tests but failed to provide the desired secret level acoustical performance. Further investigations and research into partition component and building composite performance indicated that floors walls ceilings doors windows and perimeter penetrations by conduit and HVAC ducting which individually met the design standards and when installed meet the design standards but as a composite did not provide the intended acoustical performance that would prevent unauthorized access to sensitive and secret information by persons or devices outside the designated perimeter. Reasons for certain performance failures are discussed and specific successful remedies are presented.

2013-01-01T23:59:59.000Z

344

Cross-Dipole Acoustic Log | Open Energy Information  

Open Energy Info (EERE)

Cross-Dipole Acoustic Log Cross-Dipole Acoustic Log Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Cross-Dipole Acoustic Log Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Acoustic Logs Information Provided by Technique Lithology: Stratigraphic/Structural: Rock stress and fracture analysis Hydrological: Use for fracture identification in open and cased holes. Also used for evaluating hydro fracturing/well stimulation effectiveness. Thermal: Dictionary.png Cross-Dipole Acoustic Log: An acoustic logging technique where the acoustic transmitter and receivers are lowered down hole and waveforms that travel through the well mud,

345

Progress with On-The-Fly Neutron Doppler Broadening in MCNP  

SciTech Connect (OSTI)

The University of Michigan, ANL, and LANL have been collaborating on a US-DOE-NE University Programs project 'Implementation of On-the-Fly Doppler Broadening in MCNP5 for Multiphysics Simulation of Nuclear Reactors.' This talk describes the project and provides results from the initial implementation of On-The-Fly Doppler broadening (OTF) in MCNP and testing. The OTF methodology involves high precision fitting of Doppler broadened cross-sections over a wide temperature range (the target for reactor calculations is 250-3200K). The temperature dependent fits are then used within MCNP during the neutron transport, for OTF broadening based on cell temperatures. It is straightforward to extend this capability to cover any temperature range of interest, allowing the Monte Carlo simulation to account for a continuous distribution of temperature ranges throughout the problem geometry.

Brown, Forrest B. [Los Alamos National Laboratory; Martin, William R. [Los Alamos National Laboratory; Yesilyurt, Gokhan [Argonne National Laboratory; Wilderman, Scott [University of Michigan

2012-06-18T23:59:59.000Z

346

Effect of Doppler broadening on Autler-Townes splitting in the molecular cascade excitation scheme  

Science Journals Connector (OSTI)

Theoretical analysis of the Autler-Townes splitting pattern in a three-level cascade excitation of a Doppler-broadened sample reveals that the observed Autler-Townes splitting is not only a function of the coupling-laser Rabi frequency, as in the homogeneously broadened case, but can also strongly depend on the wavenumber ratio of the coupling and probe lasers. Utilizing a steady-state density matrix formalism, we derive exact expressions for the populations of the intermediate and upper levels for a homogeneously broadened system. In the limit of a weak probe field, analytical expressions for Doppler-broadened excitation spectra from the intermediate and upper levels are derived. Using these expressions, we investigate the critical role of Doppler broadening on the observation of Autler-Townes splitting and its asymptotic behavior as a function of the coupling Rabi frequency for counterpropagating and copropagating configurations for different wavenumber ratios of the lasers.

E. Ahmed and A. M. Lyyra

2007-11-09T23:59:59.000Z

347

Why should we correct reported pulsation frequencies for stellar line-of-sight Doppler velocity shifts?  

E-Print Network [OSTI]

In the age of Kepler and Corot, extended observations have provided estimates of stellar pulsation frequencies that have achieved new levels of precision, regularly exceeding fractional levels of a few parts in $10^{4}$. These high levels of precision now in principle exceed the point where one can ignore the Doppler shift of pulsation frequencies caused by the motion of a star relative to the observer. We present a correction for these Doppler shifts and use previously published pulsation frequencies to demonstrate the significance of the effect. We suggest that reported pulsation frequencies should be routinely corrected for stellar line-of-sight velocity Doppler shifts, or if a line-of-sight velocity estimate is not available, the frame of reference in which the frequencies are reported should be clearly stated.

Davies, G R; Miglio, A; Campante, T L; Chaplin, W J; Elsworth, Y

2014-01-01T23:59:59.000Z

348

Effects of Doppler broadening on Autler-Townes splitting in six-wave mixing  

SciTech Connect (OSTI)

The effects of Doppler broadening on Autler-Townes (AT) splitting in six-wave mixing (SWM) are investigated by the dressed-state model. We analyze the velocities at which the atoms are in resonance with the dressed states through Doppler frequency shifting and find that, depending on the wave-number ratio, there may be two resonant velocities which can originate from resonance with one of the dressed states or from resonance with two different dressed states. Based on this model, we discuss a novel type of AT doublet in the SWM spectrum, where macroscopic effects play an important role. Specifically, the existence of resonant peaks requires polarization interference between atoms of different velocities in addition to a change in the number of resonant atoms involved. Our model can also be employed to analyze electromagnetically induced transparency resonance and other types of Doppler-free high-resolution AT spectroscopy.

Niu Jinyan [Laboratory of Optical Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Pei Liya; Lu Xiaogang; Wang Ruquan; Wu Lingan; Fu Panming [Laboratory of Optical Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2011-09-15T23:59:59.000Z

349

Intrinsic Lorentz violation in Doppler effect from a moving point light source  

E-Print Network [OSTI]

Einstein's Doppler formula is not applicable when a moving point light source is close enough to the observer; for example, it may break down or cannot specify a determinate value when the point source and the observer overlap. In this paper, Doppler effect for a moving point light source is analyzed, and it is found that the principle of relativity allows the existence of intrinsic Lorentz violation. A conceptual scheme to experimentally test the point-source Doppler effect is proposed, and such a test could lead to an unexpected result that the frequency of a photon may change during propagation, which questions the constancy of Planck constant since the energy conservation in Einstein's light-quantum hypothesis must hold.

Changbiao Wang

2010-07-06T23:59:59.000Z

350

Optical frequency standards for gravitational wave detection using satellite Doppler velocimetry  

E-Print Network [OSTI]

Gravitational waves imprint apparent Doppler shifts on the frequency of photons propagating between an emitter and detector of light. This forms the basis of a method to detect gravitational waves using Doppler velocimetry between pairs of satellites. Such detectors, operating in the milli-hertz gravitational frequency band, could lead to the direct detection of gravitational waves. The crucial component in such a detector is the frequency standard on board the emitting and receiving satellites. We point out that recent developments in atomic frequency standards have led to devices that are approaching the sensitivity required to detect gravitational waves from astrophysically interesting sources. The sensitivity of satellites equipped with optical frequency standards for Doppler velocimetry is examined, and a design for a robust, space-capable optical frequency standard is presented.

Vutha, Amar C

2015-01-01T23:59:59.000Z

351

Effect of a spectral line with Doppler broadening on optical bistability in a ring cavity  

Science Journals Connector (OSTI)

We discuss the effect of a spectral line with Doppler broadening on optical bistability in a ring cavity which contains a saturable absorber of two-level atoms. In this paper, we first derive a generalized equation that is satisfied by the output light intensity of this system from the Langevin equations in H. Haken’s Laser Theory (Springer, Heidelberg, 1970). Then, we simplify the generalized equation for a single mode. We study the single-mode equation for both nonexisting and existing spontaneous emission and obtain the result that the square of the bistability loop increases with the increase of Doppler broadening of the spectral line.

Feng Qi-yuan; Liu Ya-jie; Yang Xing-yu

1988-10-15T23:59:59.000Z

352

Radiative transfer effects on Doppler measurements as sources of surface effects in sunspot seismology  

E-Print Network [OSTI]

We show that the use of Doppler shifts of Zeeman sensitive spectral lines to observe wavesn in sunspots is subject to measurement specific phase shifts arising from, (i) altered height range of spectral line formation and the propagating character of p mode waves in penumbrae, and (ii) Zeeman broadening and splitting. We also show that these phase shifts depend on wave frequencies, strengths and line of sight inclination of magnetic field, and the polarization state used for Doppler measurements. We discuss how these phase shifts could contribute to local helioseismic measurements of 'surface effects' in sunspot seismology.

S. P. Rajaguru; K. Sankarasubramanian; R. Wachter; P. H. Scherrer

2006-11-29T23:59:59.000Z

353

Importance of the Doppler Effect to the Determination of the Deuteron Binding Energy  

E-Print Network [OSTI]

The deuteron binding energy extracted from the reaction ${}^1H(n,\\gamma){}^2H$ is reviewed with the exact relativistic formula, where the initial kinetic energy and the Doppler effect are taken into account. We find that the negligible initial kinetic energy of the neutron could cause a significant uncertainty which is beyond the errors available up to now. Therefore, we suggest an experiment which should include the detailed informations about the initial kinetic energy and the detection angle. It could reduce discrepancies among the recently reported values about the deuteron binding energy and pin down the uncertainty due to the Doppler broadening of $\\gamma$ ray.

Yongkyu Ko; Myung Ki Cheoun; Il-Tong Cheon

1999-04-01T23:59:59.000Z

354

Observation of a Motional Stark Effect to Determine the Second-Order Doppler Effect  

Science Journals Connector (OSTI)

The high resolution two-photon spectroscopy of hydrogen is often limited by the second-order Doppler effect. To determine this effect, we apply a magnetic field perpendicular to the atomic beam. This field induces a quadratic motional Stark shift proportional, as the second-order Doppler effect, to v2 (v atomic velocity). For some magnetic field, these two effects are opposite and the total shift due to the atomic velocity is reduced. We present the first observation of this effect for the 1S-3S transition in hydrogen.

G. Hagel; R. Battesti; F. Nez; L. Julien; F. Biraben

2002-10-23T23:59:59.000Z

355

An Autonomous Doppler Sodar Wind Profiling System PHILIP S. ANDERSON, RUSSELL S. LADKIN, AND IAN A. RENFREW  

E-Print Network [OSTI]

An Autonomous Doppler Sodar Wind Profiling System PHILIP S. ANDERSON, RUSSELL S. LADKIN, AND IAN A form 27 September 2004) ABSTRACT An autonomous Doppler sodar wind profiling system has been designed panels, and two vertical axis wind generators, plus charging control and isolation circuitry. The sodar

Renfrew, Ian

356

Laboratory experiments as demos and projects in the underwater acoustics and sonar course  

Science Journals Connector (OSTI)

Underwater Acoustics and Sonar (SP411) is a 3?h course that is typically offered to Midshipmen in their senior year. General science majors take the course in the fall while the oceanography majors enroll in the spring. A sprinkling of physics electrical engineers ocean engineers and systems majors also populate the course (totaling ?110 students/yr). Since this course is offered without a lab the ‘‘in?class’’ experience has been enhanced with the development (over many years) of our demo carts which surround the classroom. Although Friday is our major ‘‘demo day ’’ demos are performed throughout the week. They motivate the students’ ‘‘out?of?class’’ experimental projects. Demos include: (a) waves on slinkies; (b) Fourier analysis of tones in noise homemade musical instruments; (c) harmonic synthesis; (d) receiver operating characteristics from processed signals in noise; (e) two?element and loudspeaker beam patterns; (f) sound speed versus temperature in water; (g) target strength versus angle of a model sub; (h) Ref. coef. from an Al/water interface; (i) PC?IMAT (interactive multisensor analysis training) simulations of array steering ray tracing active sonar propagation loss; and (j) FM detection and Doppler effects. Students get involved with the measurements have fun and their understanding of underwater sound is greatly enhanced.

Elizabeth L. Simmons; Murray S. Korman

1999-01-01T23:59:59.000Z

357

Using an ADCP to estimate turbulent kinetic energy dissipation rate in sheltered coastal waters  

Science Journals Connector (OSTI)

Turbulent microstructure and acoustic Doppler current profiler (ADCP) data were collected near Tacoma Narrows in Puget Sound, WA. Over 100 coincident microstructure profiles have been compared to ADCP estimates of turbulent kinetic energy ...

A. D. Greene; P. J. Hendricks; M. C. Gregg

358

--No Title--  

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

The use of Compact Mixer Pumps to clean waste tanks will be tested at the 85' diameter tank at TNX. A StreamPro ADCP (Acoustic Doppler Current Profiler) has been ordered to measure...

359

A study of the location of the entrance of a fishway in a regulated river with CFD and ADCP  

Science Journals Connector (OSTI)

Simulation-driven design with computational fluid dynamics has been used to evaluate the flow downstream of a hydropower plant with regards to upstream migrating fish. Fieldmeasurements with an Acoustic Doppler Current Profiler were performed, and the ...

Anders G. Andersson; Dan-Erik Lindberg; Elianne M. Lindmark; Kjell Leonardsson; Patrik Andreasson; Hans Lundqvist; T. Staffan Lundström

2012-01-01T23:59:59.000Z

360

CX-000541: Categorical Exclusion Determination | Department of...  

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

Determination Checkout of StreamPro ADCP (Acoustic Doppler Current Profiler) Velocity Meter CX(s) Applied: B3.6 Date: 11162009 Location(s): Aiken, South Carolina Office(s):...

Note: This page contains sample records for the topic "acoustic doppler current" 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

Acoustic boundary layer and acoustic radiation from a ribbed flat plate  

Science Journals Connector (OSTI)

The acoustic boundary?layer theory(patterned after the viscous boundary?layer theory) is derived by noting that for low frequencies where the structural wavelength is much less than the fluid acoustic wavelength there is a region about the vibrating structure which behaves as if the fluid was incompressible. The dimension of this region depends upon the particular conditions of the problem. In a paper presented by the author [J. Acoust. Soc. Am. 62 S32(A) (1977)] the theory behind the acoustic boundary layer was developed and applied to simple unit problems. In this paper the near and the far field of a force driven plate is obtained by the use of the acoustic boundary?layer theory. Two different problems are addressed. In the first instance the structure is assumed to be homogeneous while in the second problem presented a rib is attached to the flat plate. In both instances the fully coupled fluid structure problem is solved and comparisons between the exact classical approach and the proposed theory are discussed.

Mauro Pierucci

1978-01-01T23:59:59.000Z

362

Argonne Acoustic Levitation Video Goes Viral  

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

"Inside the Advanced Photon Source" Inside the latest Argonne Now "Inside the Advanced Photon Source" Inside the latest Argonne Now APS Director Stephenson Named Argonne Distinguished Fellow Advanced Photon Source, Canadian Light Source Strengthen Ties, Expand X-ray Technology and Research Rose of APS and CNM One of Four DOE Early Career Award Winners Scientists Close-In on Artificial Spider Silk APS News Archives: 2012 | 2011 | 2010 | 2009 2008 | 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed Argonne Acoustic Levitation Video Goes Viral SEPTEMBER 25, 2012 Bookmark and Share Drops of solution being suspended for a long period of time, thanks to the vibrational force of sound waves that keep them stationary in an air column. More than 41,000 Google hits for "acoustic levitation Argonne" as of

363

Definition: Acoustic Televiewer | Open Energy Information  

Open Energy Info (EERE)

Televiewer Televiewer Jump to: navigation, search Dictionary.png Acoustic Televiewer The Acoustic Televiewer (ATV) log provides a very-high resolution, sonic image of the borehole wall. The tool consists of an ultrasonic transducer coupled with a downhole inclinometer. These devices are used to generate an oriented image of seismic velocity variation and wave amplitude. These images are then examined and highlighted to reveal fractures, bedding planes and orientation of those features. The log is useful for strata and fracture delineation, and can also be used to evaluate compressional-wave velocity, borehole deviation and eccentricity.[1] References ↑ http://www.dot.ca.gov/hq/esc/geotech/gg/atv_log.htm Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like.

364

Development of a geothermal acoustic borehole televiewer  

SciTech Connect (OSTI)

Most geothermal wells are drilled in hard rock formations where fluid flow is through systems of open fractures. Productivity of these wells is usually determined by the extent of intersection of the wellbore with the fracture system. A need exists for fracture mapping methods and tools which can operate in a geothermal environment. In less hostile environments, the acoustic borehole televiewer has been shown to be a useful tool for determining location, orientation, and characterization of fractures as they intersect the borehole and for general wellbore and casing inspection. The development conducted at Sandia National Laboratories to adapt an acoustic borehole televiewer for operation in a geothermal environment is described. The modified instrument has been successfully tested at temperatures as high as 280/sup 0/C and pressures up to 5000 psi, and used successfully to map fractures and casing damage in geothermal wells.

Heard, F.E.; Bauman, T.J.

1983-08-01T23:59:59.000Z

365

Broadband acoustic imaging of breaking waves  

Science Journals Connector (OSTI)

An acoustic array was deployed in the near?surface layer in Saanich Inlet BC to image breaking waves using only the naturally occurring acoustical radiation in the band (160 and 2000 Hz) from the breaking region. The 15?element array was configured as a horizontal cross with an 8?m aperture bottom?moored and positioned nominally 3 m beneath the surface. A novel broadband scheme combined information at six independent frequencies above about 400 Hz to yield unambiguous resolved images. A parametric image analysis shows that the images align closely with the wind and can be observed moving downwind with a speed roughly equal to the dominant phase speed of the wind waves. Absolute power levels are found to be consistent with previously published results. The data also provide inferences regarding the sound generation mechanism at ‘‘collective oscillation’’ frequencies below about 400 Hz. [Work supported by ONR.

Rex K. Andrew; David M. Farmer; R. Lynn Kirlin

1997-01-01T23:59:59.000Z

366

Powerful, efficient, robust, electro?acoustic transducers  

Science Journals Connector (OSTI)

The STAR™ resonant reciprocating transducer began as a lightweight linear alternator design for a space?power free?piston Stirling engine in the early 1990's. It has since been developed into a range of commercially available motors and alternators with rated powers from 100 to over 10 000 watts (acoustic). As motors these are acoustic pressure drivers with unlimited operating life and typical transduction efficiencies of 80?90 percent. This paper explains the electrodynamics and operation of these moving? magnet Lorentz?force devices and the unique geometric configuration that has allowed scaling over such a wide range. We discuss the design and function of the unique single?degree?of?freedom flexure suspension that enables both the compact geometry and unlimited service life without wear. Data is presented from a large sample of units placed in service during the last decade demonstrating the durability and performance of these remarkable devices.

John Corey

2008-01-01T23:59:59.000Z

367

An overview of time?reversal acoustics  

Science Journals Connector (OSTI)

Time?reversal invariance is a very powerful concept in physics. In the field of acoustics where time reversal invariance occurs time?reversal experiments may be achieved simply with arrays of transmit?receive transducers allowing an incident wave field to be sampled recorded time?reversed and re?emitted. Time reversal mirrors (TRMs) may be used to study random media and chaotic reverberating structures. Common to these complex media is a remarkable robustness exemplified by observations that the more complex the medium between the probe source and the TRM the sharper the focus. TRMs open the way to new signal processings that interest imaging detection telecommunications and therapy. Time reversal mirrors have plenty of applications including ultrasonic therapy and medical imaging non destructive testing telecommunications underwater acoustics seismology sound control home automation. An overview of these fields will be presented.

Mathias Fink

2008-01-01T23:59:59.000Z

368

Pulse combusted acoustic agglomeration apparatus and process  

DOE Patents [OSTI]

An improved apparatus and process for removal of particulates entrained in a gas stream are provided. The removal process employs a pulse combustor to provide an acoustic pressure wave to acoustically enhance agglomeration of particulates which may be collected and removed using a conventional separation apparatus. The apparatus may be employed as a direct fired system for improved operation of gas-operated equipment such as a gas turbine, or may, alternatively, be employed as an add-on subsystem for combustion exhaust clean-up. Additionally, added particulates may include a sorbent for effecting sorption of other contaminants such as sulfur. Various other particulates for contaminant removal may also be introduced into the system as exemplified by alkali-gettering agents.

Mansour, Momtaz N. (Columbia, MD); Chandran, Ravi (Ellicott City, MD)

1994-01-01T23:59:59.000Z

369

Pulse combusted acoustic agglomeration apparatus and process  

DOE Patents [OSTI]

An improved apparatus and process for removal of particulates entrained in a gas stream are provided. The removal process employs a pulse combustor to provide an acoustic pressure wave to acoustically enhance bimodal agglomeration of particulates which may be collected and removed using a conventional separation apparatus. A particulate having a size different from the size of the particulate in the gas stream to be cleaned is introduced into the system to effectuate the bimodal process. The apparatus may be employed as a direct fired system for improved operation of gas-operated equipment such as a gas turbine, or may, alternatively, be employed as an add-on subsystem for combustion exhaust clean-up. Additionally, the added particulate may be a sorbent for effecting sorption of other contaminants such as sulfur. Various other particulates for contaminant removal may also be introduced into the system as exemplified by alkali-gettering agents.

Mansour, Momtaz N. (Columbia, MD)

1993-01-01T23:59:59.000Z

370

Acoustically determined linear piezoelectric response of lithium niobate up to 1100?V  

SciTech Connect (OSTI)

We present a method to measure high voltages using the piezoelectric crystal lithium niobate without using voltage dividers. A 36° Y-X cut lithium niobate crystal was coupled to two acoustic transducers, where direct current voltages were applied from 128–1100?V. The time-of-flight through the crystal was determined to be linearly dependent on the applied voltage. A model was developed to predict the time-delay in response to the applied voltage. The results show a sensitivity of 17 fs/V with a measurement error of 1 fs/V was achievable using this method. The sensitivity of this method can be increased by measuring the acoustic wave after multiple passes through the crystal. This method has many advantages over traditional techniques such as: favorable scalability for larger voltages, ease of use, cost effectiveness, and compactness.

Patel, N. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Branch, D. W.; Cular, S. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Schamiloglu, E. [Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87106 (United States)

2014-04-21T23:59:59.000Z

371

SoundWave: Using the Doppler Effect to Sense Gestures Sidhant Gupta1,2  

E-Print Network [OSTI]

custom patch antennas. They used the reflected Doppler- shifted signal to infer human motion and upper-facing RGB webcam to allow the user to control PowerPoint slides or music/video playback. Unfortunately) and require quite a bit of processing power. The Microsoft Xbox Kinect is another example of a successfully

Anderson, Richard

372

On Deriving Vertical Air Motions from Cloud Radar Doppler Spectra MATTHEW D. SHUPE  

E-Print Network [OSTI]

on a statistical comparison of four cases comprising nearly 6 h of data. Turbulent dissipation rate comparisons multiple ground-based remote sensors. Corrections for Doppler spectrum broadening due to turbulence, wind the Department of Energy (DOE) Atmospheric Radiation Measurement Program's (ARM) site in Barrow, Alaska, during

373

Progress towards an accurate determination of the Boltzmann constant by Doppler spectroscopy  

E-Print Network [OSTI]

, 27] consists in recording the Doppler profile of a well- isolated absorption line of an atomic absorption profile of a line in a gas of ammonia at thermal equilibrium. This optical method based) ppm broadening of the absorption linewidth. We also show that, in our well chosen experimental

374

Improved forecasts of extreme weather events by future space borne Doppler wind lidar  

E-Print Network [OSTI]

sensitive areas. To answer these questions simulation experiments with state-of-the-art numerical weather prediction (NWP) models have proved great value to test future meteorological observing systems a prioriImproved forecasts of extreme weather events by future space borne Doppler wind lidar Gert

Marseille, Gert-Jan

375

Cloud radar Doppler spectra in drizzling stratiform clouds: 1. Forward modeling and remote sensing applications  

E-Print Network [OSTI]

Cloud radar Doppler spectra in drizzling stratiform clouds: 1. Forward modeling and remote sensing broadening and drizzle growth in shallow liquid clouds remain not well understood. Detailed, cloudscale. Profiling, millimeterwavelength (cloud) radars can provide such observations. In particular, the first three

376

Estimation and Mapping of Hurricane Turbulent Energy Using Airborne Doppler Measurements  

Science Journals Connector (OSTI)

Hurricane turbulent kinetic energy (TKE) was computed using airborne Doppler measurements from the NOAA WP-3D tail radars, and TKE data were retrieved for a variety of storms at different stages of their life cycle. The geometry of the radar ...

Sylvie Lorsolo; Jun A. Zhang; Frank Marks Jr.; John Gamache

2010-09-01T23:59:59.000Z

377

The Impact of Doppler Spreading on Delay Performance over Multi-hop Wireless Communications  

E-Print Network [OSTI]

promising technologies to provide high data rate transmission through wireless link in multi-hop networks-to-end delay performance over multi-hop wireless transmission. In this paper, we study the impact of Doppler communications are very promising technologies for next generation network to provide high data rate transmission

Haddadi, Hamed

378

A Three-Dimensional Variational Data Analysis Method with Recursive Filter for Doppler Radars  

Science Journals Connector (OSTI)

In this paper, a new method of dual-Doppler radar wind analysis based on a three-dimensional variational data assimilation (3DVAR) approach is proposed. In it, a cost function, including background term and radial observation term, is minimized ...

Jidong Gao; Ming Xue; Keith Brewster; Kelvin K. Droegemeier

2004-03-01T23:59:59.000Z

379

Observation of fast-ion Doppler-shifted cyclotron resonance with shear Alfvn waves  

E-Print Network [OSTI]

are produced by neutral or ion beam injection,1 by ion cyclotron2 or lower hybrid heating,3 and by fusion ions by Alfvén waves well below the ion cyclotron resonance frequency might cause ion heatingObservation of fast-ion Doppler-shifted cyclotron resonance with shear Alfvén waves Yang Zhang,1 W

Heidbrink, William W.

380

A Doppler Radar Emulator with an Application to the Detectability of Tornadic Signatures  

E-Print Network [OSTI]

System (ARPS). Several metrics for tornado intensity are examined, including peak Doppler velocity range, if standard metrics such as azimuthal gate-to-gate shear from a single radar are used for detection. 1. Introduction The design of a weather radar system and its scan- ning strategy involves trade

Xue, Ming

Note: This page contains sample records for the topic "acoustic doppler current" 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

The game of the "very small" and the "very big": The case of the Doppler Effect  

E-Print Network [OSTI]

In the study of the Doppler Effect, non-locality is not taken into account. We present two cases in which a continuous change in the receiver's speed and in the angle at which the successive wavecrests are received takes place. In each case the error committed by not taking into account the non-locality is evaluated.

Bernhard Rothenstein; Albert Rothenstein

2003-08-27T23:59:59.000Z

382

INFLUENCE OF DOPPLER WIDTH FLUCTUATIONS ON THE SHAPE OF SPECTRAL LINES  

SciTech Connect (OSTI)

We investigate the influence of stochastic Doppler width fluctuations on the shape of spectral lines. The photospheres and atmospheres of stars, and the interstellar medium, possess stochastic behavior especially near nonstationary objects such as active galactic nuclei, quasars, flare stars, and regions of star formation. In reality, we observe the mean values of intensities from these objects. In most situations, the spectral line extinction coefficient has a Gaussian shape with the stochastic Doppler width determined by thermal and small-scale turbulent motions of atoms or molecules. For small-scale turbulent motions (short-correlated turbulence) the propagation of radiation is described by the average extinction factor. This coefficient depends on the level of the Doppler width fluctuations {eta}. We show that these fluctuations change both the value of intensity and the shape of spectral lines. We consider distortions of the spectral line shapes for the absorption and emission lines for various values of the parameter {eta}. For a number of H{sub 2}O maser sources we estimate the values of this parameter, the optical depths of the inverted media, and the mean effective Doppler velocities. Maser emission lines with non-Gaussian shape can serve as an additional method for the investigation of the physical parameters in maser 'spots'.

Silant'ev, N. A.; Lekht, E. E. [Instituto Nacional de AstrofIsica, Optica y Electronica, Apartado Postal 51 y 216, 72840, Tonantzintla, Puebla (Mexico); Alexeeva, G. A. [Central (Pulkovo) Astronomical Observatory of Russian Academy of Sciences, Pulkovskoe shosse 65, St. Petersburg, 196140 (Russian Federation)], E-mail: silant@inaoep.mx

2009-05-10T23:59:59.000Z

383

Lie symmetry analysis of electron–electromagnetic wave interaction under condition of the anomalous Doppler effect  

Science Journals Connector (OSTI)

Abstract Lie symmetry analysis is applied for a problem of interaction of electron cyclotron oscillators with a slow electromagnetic wave under condition of the anomalous Doppler effect. This analysis reveals scaling invariance of the system and existence of self-similar solutions which describe amplification of a short electromagnetic pulse with its subsequent compression. The results of theoretical analysis are confirmed by numerical simulations.

N.M. Ryskin

2014-01-01T23:59:59.000Z

384

Periodic Flux Variability of Stars due to the Reflex Doppler Effect Induced by Planetary Companions  

E-Print Network [OSTI]

Upcoming space-based photometric satellites offer the possibility of detecting continuum flux variability at the micro-magnitude level. We show that the Doppler flux variability induced by the reflex motion of stars due to planetary companions has an amplitude of (3-alpha)K/c, where K is the reflex radial velocity amplitude and alpha is the logarithmic slope of source spectral flux in the observed frequency band. For many of the known close-in planetary systems with periods less than ~0.2 years, the periodic Doppler variability is of order a micromagnitude, and is significant relative to the variability caused by reflected light from the planetary companion. For companions with periods greater than ~0.2 years, the Doppler signal is larger than the reflected light signal. We show that the future photometric satellites should reach the sensitivity to detect this Doppler variability. In particular, the Kepler satellite should have the photon-noise sensitivity to detect at a signal-to-noise ratio > 5, all planets with minimum mass greater than 5 Jupiter masses, and periods less than 0.1 years around the 10,000 main-sequence stars with spectral types A through K and apparent magnitude V<12 in its field-of-view.

Abraham Loeb; B. Scott Gaudi

2003-03-10T23:59:59.000Z

385

Doppler effect in fragment autoionization following core-to-valence excitation in O{sub 2}  

SciTech Connect (OSTI)

Atomic autoionization following O 1s resonant excitation in O{sub 2} is studied using high-resolution electron spectroscopy. The resonant Auger spectrum showing evidence of ultrafast dissociation as well as the autoionization of oxygen atoms is measured and discussed. Evidence of the electronic Doppler effect is observed in both electronic decay mechanisms.

Guillemin, Renaud; Simon, Marc; Shigemasa, Eiji [Universite Pierre et Marie Curie, Laboratoire de Chimie Physique-Matiere et Rayonnement, UMR 7614, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05, France and Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique-Matiere et Rayonnement, UMR 7614, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05 (France); Ultraviolet Synchrotron Orbital Radiation Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan)

2010-11-15T23:59:59.000Z

386

Experimental Investigation of the Effect of Speckle Noise on Continuous Scan Laser Doppler Vibrometer Measurements  

E-Print Network [OSTI]

Period i : Phase Variable v : Voltage Signal fsamp : Sampling Frequency y : Response Signal fscan Research Building 1500 Engineering Drive Madison, WI 53706 Abstract Continuous Scan Laser Doppler when the scan frequency is high relative to the highest natural frequency of interest, and state

Allen, Matthew S.

387

Ongoing developments in classroom acoustic theory and practice in 2012, and reports on efforts to implement good classroom acoustics  

Science Journals Connector (OSTI)

We live in a time of increasingly loud competing sounds and hearing loss is the number one disability in the world. Diverse populations of school children are especially vulnerable. The result is a degradation of the child’s academic achievement. New classrooms built everyday often incorporate acoustical barriers which limit students’ achievements. Overcoming these barriers involves funding constraints construction timelines and lack of support which requires advocacy from parents school boards and design teams. This advocacy should include the ANSI Classroom Acoustics standards and an acoustical assessment of existing classrooms. Complex classroom acoustics challenges may include reduction of noise radiated by HVAC systems improved acoustic treatment of external walls to minimize exterior noise and acoustic design of walls between adjacent noisy classrooms. Next steps for schools should be to retain an architect and/or an acoustical engineer for remodels and new school construction who are well versed in acoustics for educational settings and noise control. A booklet covering these issues and designed as a practical guide for educators not versed in acoustics is in preparation by the Acoustical Society of America.

Pamela Brown; Mary Crouse

2012-01-01T23:59:59.000Z

388

Acoustic enhancement for photo detecting devices  

DOE Patents [OSTI]

Provided are improvements to photo detecting devices and methods for enhancing the sensitivity of photo detecting devices. A photo detecting device generates an electronic signal in response to a received light pulse. An electro-mechanical acoustic resonator, electrically coupled to the photo detecting device, damps the electronic signal and increases the signal noise ratio (SNR) of the electronic signal. Increased photo detector standoff distances and sensitivities will result.

Thundat, Thomas G; Senesac, Lawrence R; Van Neste, Charles W

2013-02-19T23:59:59.000Z

389

Acoustic measurement of potato cannon velocity  

E-Print Network [OSTI]

This article describes measurement of potato cannon velocity with a digitized microphone signal. A microphone is attached to the potato cannon muzzle and a potato is fired at an aluminum target about 10 m away. The potato's flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato velocity is simply the flight distance divided by the flight time.

Courtney, M; Courtney, Amy; Courtney, Michael

2006-01-01T23:59:59.000Z

390

Acoustic radiation due to surface wave breaking.  

Science Journals Connector (OSTI)

While wave breaking is continually occurring at the sea surface its transient and sporadic nature makes it difficult to measure. Experimental results are presented that show how acoustic methods can be used as a remote sensor of this fundamental process. Sea surface?generated acoustic radiation (40 to 4000 Hz) is directly related to a quantitative measure of the boundary dynamics; i.e. the Toba variable. The frequency spectrum of the radiation remains remarkably unchanged over a wide range of environmental conditions but the correlation between the sound pressure level and the Toba variable undergoes an abrupt change when spilling breakers start to occur. Results support the use of acoustics to remotely measure the rate of energy being dissipated by wave breaking and the wavelength of the dominant gravity wave component. Theoretical studies have related the field measurements to analytical and laboratory results cited in the literature indicating that remote monitoring of the rate of occurrence and size distribution of ‘‘infant’’ (freshly entrained) bubbles may be possible if splashes on the surface do not radiate significant sound. Signal processing algorithms for the remote measurements discussed above are enhanced by eigenstructure analysis of the measured cross?spectral density matrix. [Work sponsored by ONR and NUSC.

Robert M. Kennedy; Stewart A. L. Glegg

1992-01-01T23:59:59.000Z

391

Air transducers with high acoustic impedance  

Science Journals Connector (OSTI)

High?Z air transducers evolved from several industrial transducers. These predecessors include (a) acoustic emission and angle?beam NDT contact transducers; (b) flowmeter transducers for high?pressure methane hot refinery gases and corrosive flare gases; and (c) transducer arrays for monitoring hot corrosive gases flowing at Mach 0.1 in smokestacks of ?3–13 m. This peculiar ancestry accounts for their unusual high?acoustic?impedance construction. By not employing low?Z air?backed radiating membranes transducer bandwidth response time and sensitivity are sacrificed. The solid robust construction however offers some compensating features: tolerance to wide ranges in pressure and temperature including rapid rates of change (thermal shock depressurization); corrosion resistance; operable with standard lab equipment without bias voltage; mounting options where the transducer forms part of the pressure boundary or where it is outside the pressure boundary. Clamp?on air flow applications at one bar include small wind tunnels and plastic pipes. Acoustically isolated pairs measure secondary flow components (crossflow circulation) in a plane perpendicular to the pipe axis. Flow applications include gases such as air mild steam (pending) or other hot pressurized or corrosive fluids. Air?coupled measurements of transmission characteristics of wood or other low?density solids and air?ranging are readily demonstrated with the low?Z transducers.

Lawrence C. Lynnworth

1998-01-01T23:59:59.000Z

392

Acoustical renovation of portable classrooms for cochlear implanted pupils  

Science Journals Connector (OSTI)

Anticipating increased enrollment of children with cochlear implants the Riverside County Office of Education undertook the acoustical renovation of two portable classrooms in California’s Riverside County: Wildomar Elementary School in Wildomar and Katherine Finchy Elementary School in Palm Springs. The aim was to improve the acoustical environment to make the classrooms suitable for pupils with severe hearing disabilities (reduce noise and reverberation). Lacking an acoustical standard specific for cochlear implanted pupils the acoustical goals chosen were those of the ANSI acoustical standard S12.60?2002. Key changes were intended to reduce interior noise from HVAC and improve the facade insulation to reduce exterior noise intrusion. The resulting acoustical improvements are documented. Costs and lessons learned are discussed.

2004-01-01T23:59:59.000Z

393

Electret Acoustic Transducer Array For Computerized Ultrasound Risk Evaluation System  

DOE Patents [OSTI]

An electret-based acoustic transducer array is provided and may be used in a system for examining tissue. The acoustic transducer array is formed with a substrate that has a multiple distinct cells formed therein. Within each of the distinct cells is positioned an acoustic transducing element formed of an electret material. A conductive membrane is formed over the distinct cells and may be flexible.

Moore, Thomas L. (Livermore, CA); Fisher, Karl A. (Brentwood, CA)

2005-08-09T23:59:59.000Z

394

Penn State's graduate program in acoustics  

Science Journals Connector (OSTI)

The posters will present a comprehensive overview of the graduate program in acoustics at Penn State. In part the posters will contain the following: (1) descriptions of the acoustics and related courses offered; (2) examples of the facilities available and the research being conducted; (3) listings of graduate theses completed and in progress; (4) information on special extended education programs—telecommunication and summer—leading to a master's degree in acoustics.

Alan D. Stuart

1988-01-01T23:59:59.000Z

395

Null vector fields in spaces with affine connections and metrics. Doppler's effect, Hubble's effect, and aberration's effect  

E-Print Network [OSTI]

The notion of null (isotropic) vector field is considered in spaces with affine connections and metrics as models of space or space-time. On its basis the propagation of signals in space-time is considered. The Doppler effect is generalized for these types of spaces. The notions of standard (longitudinal) Doppler effect and transversal Doppler effect are introduced. On their grounds, the Hubble effect and the aberration effect appear as Doppler effects with explicit forms of the centrifugal (centripetal) and Coriolis velocity vector fields in spaces with affine connections and metrics. The upper limit of the value of the general observed shift parameter z, generated by both the effects, based on the Doppler effects, is found to be z = 1.41. Doppler's effects, Hubble's effect, and aberration's effect could be used in mechanics of continuous media and in other classical field theories in the same way as the standard Doppler effect is used in classical and relativistic mechanics. PACS numbers: 04.20.Cv; 04.50.+h; 04.40.b; 04.90.+e; 83.10.Bb

Sawa Manoff

2003-05-07T23:59:59.000Z

396

Phase control of probe response in a Doppler-broadened N-type four-level system  

SciTech Connect (OSTI)

In this paper, we investigate theoretically the effect of the relative phase ({phi}) between the probe and driving fields on gain (absorption) and dispersion of the probe field in a Doppler-broadened N-type four-level system with spontaneously generated coherence from different respects. It is shown that gain (absorption) and dispersion are very sensitive to variations in the relative phase, and changing the Doppler width also has an obvious effect on the phase-dependent gain (absorption) and dispersion. When the probe and driving fields have the same propagation directions (copropagating), for the same Doppler width, the dispersion curve with {phi}={alpha} is the same as the gain (absorption) curve with {phi}={alpha}+{pi}/2; however, when the probe and driving fields have opposite propagation directions (counterpropagating), the dispersion curve and gain (absorption) curve are different and the difference becomes more considerable with an increase in Doppler width. In the co- and counterpropagating cases, gain (absorption) and dispersion always vary periodically with varying {phi}, and the period is 2{pi}. By adjusting the value of {phi}, the largest gain (absorption) and dispersion can be obtained, and a large index of refraction without absorption can be realized. Generally speaking, gain decreases with an increase in Doppler width, but by adjusting value of {phi}, at some special values of Doppler width, a larger gain than that without Doppler broadening can be obtained. Our study also shows that gain in the copropagating case is much larger than that in the counterpropagating case.

Fan Xijun; Liu Zhongbo; Liang Ying; Jia Kening [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Tong Dianmin [School of Physics, Shandong University, Jinan 250100 (China)

2011-04-15T23:59:59.000Z

397

Spectral-element numerical modeling for acoustic and elastic  

E-Print Network [OSTI]

problems: many oil fields are located offshore (deep offshore, or shallower). · Anisotropic rocks dispersive surface waves. Oil industry applications Offshore In foothill regions #12;Ocean acoustics

398

COMPARISON OF ACOUSTIC AND ELECTRICAL IMAGE LOGS FROM THE COSO...  

Open Energy Info (EERE)

to permeability in the reservoir. Acoustic image logs reveal a similar natural fracture population, but generally image slightly fewer fractures, and do not reveal rock...

399

A new method to measure the acoustic surface impedance outdoors  

Science Journals Connector (OSTI)

......Comparative Study Evaluation Studies Journal Article Validation Studies | Acoustics Algorithms Automobiles Construction Materials analysis Electric Impedance Materials Testing methods Models, Theoretical Noise, Transportation Radiation Monitoring......

S. Carpinello; Ph. L'Hermite; M. Bérengier; G. Licitra

2004-11-01T23:59:59.000Z

400

Acoustic scattering by axisymmertic finite-length bodies with application to fish : measurement and modeling  

E-Print Network [OSTI]

This thesis investigates the complexities of acoustic scattering by finite bodies in general and by fish in particular through the development of an advanced acoustic scattering model and detailed laboratory acoustic ...

Reeder, D. Benjamin (Davis Benjamin), 1966-

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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

E-Print Network 3.0 - acoustic measurements Sample Search Results  

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

2008 NOAA-TM-NMFS-SWFSC-429 Summary: by the acoustics team (Table 9, Fig. 19). Acoustic detection distances were not measured for this group. P. electra... NMFS ACOUSTIC STUDIES...

402

E-Print Network 3.0 - acoustical measurements Sample Search Results  

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

2008 NOAA-TM-NMFS-SWFSC-429 Summary: by the acoustics team (Table 9, Fig. 19). Acoustic detection distances were not measured for this group. P. electra... NMFS ACOUSTIC STUDIES...

403

Acoustic energy radiated by nonlinear spherical oscillations of strongly driven bubbles  

Science Journals Connector (OSTI)

...considerations of surface stability. With the quasi-acoustic...acoustic energies of bubbles driven at 23.5kHz...universal boundary of bubble stability at the upper threshold...harmonic modes on bubble levitation, stability and SLJ. Acoust...

2010-01-01T23:59:59.000Z

404

E-Print Network 3.0 - amplitude acoustic wave Sample Search Results  

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

Geosciences 15 Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma Summary: 233 Ion acoustic wave generation by a standing electromagnetic...

405

E-Print Network 3.0 - acoustic waves moving Sample Search Results  

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

Engineering 14 Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma Summary: 233 Ion acoustic wave generation by a standing electromagnetic...

406

E-Print Network 3.0 - acoustic wave gas Sample Search Results  

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

Physics 19 Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma Summary: 233 Ion acoustic wave generation by a standing electromagnetic...

407

E-Print Network 3.0 - acoustic wave induced Sample Search Results  

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

Mathematics 9 Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma Summary: 233 Ion acoustic wave generation by a standing electromagnetic...

408

E-Print Network 3.0 - acoustic waves generated Sample Search...  

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

Sciences 17 Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma Summary: 233 Ion acoustic wave generation by a standing electromagnetic...

409

E-Print Network 3.0 - acoustic wave detector Sample Search Results  

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

Physics 3 Ion acoustic wave generation by a standing electromagnetic field in a subcritical plasma Summary: 233 Ion acoustic wave generation by a standing electromagnetic...

410

E-Print Network 3.0 - acoustic wave actuated Sample Search Results  

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

Plasma actuator, flow control, acoustic control, airframe noise 1. INTRODUCTION 1.1. Background... applications. Section 3 reviews some applications related to aero-acoustics,...

411

E-Print Network 3.0 - acoustic cavitation bubble Sample Search...  

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

Collection: Physics 62 Acoustic saturation in bubbly cavitating flow adjacent to an oscillating wall T. Colonius,a) Summary: Acoustic saturation in bubbly cavitating flow...

412

E-Print Network 3.0 - acoustic measuring instruments Sample Search...  

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

text... III Center for Computer Research in Music and Acoustics (CCRMA) ... Source: Smith III, Julius Orion - Center for Computer Research in Music and Acoustics, Stanford...

413

E-Print Network 3.0 - alternative proposal acoustic Sample Search...  

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

'acoustique 1990 APPLICATION OF FAST HARTLEY TRANSFORM TO ACOUSTIC INTENSITY MEASUREMENT W.S. GAN Acoustical... Services (1989)Pte Ltd, 29 Telok Ayer Street, Singapore 0104....

414

E-Print Network 3.0 - acoustic resonance determination Sample...  

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

Collection: Mathematics 31 Acoustic Identification of Unknown Fluids Summary: Acoustic Identification of Unknown Fluids Executive Overview: Scientists at Los Alamos National......

415

E-Print Network 3.0 - anisotropic linear acoustics Sample Search...  

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

the Shallow Water '06 experiment are analyzed. Acoustic, environmental, and on-board ship radar... packet passed through the acoustic track. Preliminary analysis of the ......

416

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.

417

E-Print Network 3.0 - acoustic cardiographic assessment Sample...  

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

ACOUSTICS: RESULTS OF AN EXPERIMENTAL LABORATORY INVESTIGATION Summary: wrightii. A one-dimensional acoustic resonator technique was used to assess the biomass and effective......

418

E-Print Network 3.0 - acoustic heating Sample Search Results  

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

Collection: Engineering 46 Ocean Climate Change: Comparison of Acoustic Summary: Consortium Comparisons of gyre-scale acoustic and direct thermal measurements of heat...

419

E-Print Network 3.0 - acoustic testing Sample Search Results  

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

OCEAN Summary: A COMPARISON OF ACOUSTIC THERMOMETRY, XBT, TOPEX, AND HOT OBSERVATIONS OF OCEAN TEMPERATURE... @apl.washington.edu) Abstract - Acoustic thermometry offers naturally...

420

E-Print Network 3.0 - acoustical testing laboratory Sample Search...  

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

Engineering 10 A COMPARISON OF ACOUSTIC THERMOMETRY, XBT, TOPEX, AND HOT OBSERVATIONS OF OCEAN TEMPERATURE IN THE NORTHEAST PACIFIC OCEAN Summary: A COMPARISON OF ACOUSTIC...

Note: This page contains sample records for the topic "acoustic doppler current" 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

E-Print Network 3.0 - acoustic wave integrated Sample Search...  

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

93 Reflection of Nonlinear Acoustic Waves from the Mechanically Free Surface of an Unconsolidated Granular Medium Summary: 1 Reflection of Nonlinear Acoustic Waves from the...

422

E-Print Network 3.0 - acoustic wave total Sample Search Results  

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

98 Reflection of Nonlinear Acoustic Waves from the Mechanically Free Surface of an Unconsolidated Granular Medium Summary: 1 Reflection of Nonlinear Acoustic Waves from the...

423

E-Print Network 3.0 - acoustic gravity waves Sample Search Results  

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

45 Reflection of Nonlinear Acoustic Waves from the Mechanically Free Surface of an Unconsolidated Granular Medium Summary: 1 Reflection of Nonlinear Acoustic Waves from the...

424

E-Print Network 3.0 - acoustic wave sensing Sample Search Results  

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

62 Reflection of Nonlinear Acoustic Waves from the Mechanically Free Surface of an Unconsolidated Granular Medium Summary: 1 Reflection of Nonlinear Acoustic Waves from the...

425

E-Print Network 3.0 - acoustic tiltedti media Sample Search Results  

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

Follow geometry and physical properties of a desired acoustic system Efficient Source: Smith III, Julius Orion - Center for Computer Research in Music and Acoustics, Stanford...

426

E-Print Network 3.0 - acoustic propagation experiment Sample...  

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

of perceptual measurements Statistics for acoustics experiments Acoustics of porous media . The second... of Waveguides: Wave propagation in a guide Mode matching ...

427

E-Print Network 3.0 - acoustic neurinoma presenting Sample Search...  

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

Grant Collection: Engineering 20 Wave Gliders for Acoustic Applications Asst. Prof. Brian Bingham Summary: the design of a vehicle with integrated acoustic communication and...

428

E-Print Network 3.0 - acoustics Sample Search Results  

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

Collection: Geosciences 24 Wave Gliders for Acoustic Applications Asst. Prof. Brian Bingham Summary: Wave Gliders for Acoustic Applications Asst. Prof. Brian Bingham...

429

E-Print Network 3.0 - acoustic transfer functions Sample Search...  

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

Computer Technologies and Information Sciences 3 The Acoustic Oceanographic Buoy A Light Acoustic Data Acquisition System Summary: : The AOB functionality allows for the...

430

An overview of acoustic?structural interactions: Vibration and acoustic radiation  

Science Journals Connector (OSTI)

The structural vibration and the resulting acoustic radiation is a fully decoupled problem in a gas and a fully coupled problem in a fluid. The fluid?structure interaction problem encompasses a broad spectrum of areas of interest in engineering applications. This ranges from mechanically existed structures (acoustic radiation) to acoustically induced vibrations (elasticscattering) to hydrodynamically applied forces (flow noise). The coupled fluid?structure interaction for each of these problems is essentially the same; the difference lies in the manner utilized in applying the prescribed forcing function to the structure in satisfying the interfaceboundary condition and in analyzing the radiated acoustic field. The common link relating these problems is the fact that the same governing equations for the fluid and the structure are applicable in each of these areas. This commonality between the diverse fluid?structure interactions will be stressed. The different techniques being used to solve the problems for each of the three types of problems will be presented and a brief review of the state of the art will be given.

Mauro Pierucci

1981-01-01T23:59:59.000Z

431

History of structural acoustics and vibrations in the Acoustical Society of America  

Science Journals Connector (OSTI)

Structural acoustics refers to the interaction of sound and structures—the response of structures to sound the radiation of sound from vibrating structures and the effect of the acoustic medium on the structural vibrations. Interest in these subjects increased greatly during the 1930s and 40s because of practical applications in the design of microphones and loud speakers used in telephones radios and electronic phonographs. The combination of electrical and mechanical systems lead to the use of electrical engineering concepts such as impedance circuits and electrical analogies in the analysis of mechanical systems. In later years much of the work dealt with various aspects of underwater structures prompted by U.S. Navy interests. The field which began with classical analytical mechanics applications has progressed to new approaches including statistical energy analysis near?field acoustical holography fuzzy structures active control of vibrations and smart materials. In recognition of these new developments the name of the technical committee was changed in 1987 from ‘‘Shock and Vibration’’ to ‘‘Structural Acoustics and Vibration.’’

2002-01-01T23:59:59.000Z

432

Acoustics of Buildings: including Acoustics of Auditoriums and Sound-proofing of Rooms  

Science Journals Connector (OSTI)

... THE acoustics of buildings is a subject which has always possessed importance, but with the increasing size of ... is a subject which has always possessed importance, but with the increasing size of public buildings and the congestion of our urban populations, it has assumed much greater importance in ...

1924-07-19T23:59:59.000Z

433

Sound Science: Taking Action with Acoustics  

ScienceCinema (OSTI)

From tin whistles to sonic booms, sound waves interact with each other and with the medium through which they travel. By observing these interactions, we can identify substances that are hidden in sealed containers and obtain images of buried objects. By manipulating the ability of sound to push matter around, we can create novel structures and unique materials. Join the Lab's own sound hound, Dipen Sinha, as he describes how he uses fundamental research in acoustics for solving problems in industry, security and health.

Sinha, Dipen

2014-07-21T23:59:59.000Z

434

Montana State University Proprietary 1 Summary of Gun Shot Acoustics  

E-Print Network [OSTI]

Montana State University Proprietary 1 Summary of Gun Shot Acoustics Robert C. Maher, Montana State University 4 April 2006 Audio recordings of gun shots can provide information about the gun location interpreting such recordings arises from reverberation (overlapping acoustic signal reflections) due to the gun

Maher, Robert C.

435

Quantitative Photo-Acoustic Imaging of Small Absorbers Habib Ammari  

E-Print Network [OSTI]

Quantitative Photo-Acoustic Imaging of Small Absorbers Habib Ammari Emmanuel Bossy Vincent Jugnon Hyeonbae Kang§ December 1, 2009 Abstract In photo-acoustic imaging, energy absorption causes thermo absorber from the absorbed density. AMS subject classifications. 31B20, 35B37,35L05 Key words. photo

Kang, Hyeonbae

436

Acoustic emission monitoring of HFIR vessel during hydrostatic testing  

SciTech Connect (OSTI)

This report discusses the results and conclusions reached from applying acoustic emission monitoring to surveillance of the High Flux Isotope Reactor vessel during pressure testing. The objective of the monitoring was to detect crack growth and/or fluid leakage should it occur during the pressure test. The report addresses the approach, acoustic emission instrumentation, installation, calibration, and test results.

Friesel, M.A.; Dawson, J.F.

1992-08-01T23:59:59.000Z

437

Acoustic radiation force-based elasticity imaging methods  

Science Journals Connector (OSTI)

...Wells Acoustic radiation force-based elasticity imaging...lesions. Acoustic radiation force-based elasticity imaging...properties of soft tissue. In Handbook of elastic properties of solids...W. , Trahey, G. 1995 A fundamental limit on delay estimation using...

2011-01-01T23:59:59.000Z

438

A new concept of ocean acoustic tomography Lionel CROS(1)  

E-Print Network [OSTI]

a synthetic signal in ship noise with the con- straint to have an accurate estimation of the channel: discreet acoustic tomography, estimation, detection, optimization, performance analysis. R´ESUM´E COURT: La disc`ete, estimation, d´etection, optimisation, analyse de perfor- mance. 1 INTRODUCTION Ocean acoustic

Boyer, Edmond

439

15 Acoustic Daylight Imaging in the Michael J. Buckingham  

E-Print Network [OSTI]

of radiation, including light. Acoustic techniques are thus a pre- ferred choice for probing the ocean depths. Two types of acoustic sys- tems, passive sonar and active sonar, are commonly used as detection devices in the ocean [1]. A passive sonar simply listens for the sound radiated by a target

Buckingham, Michael

440

An Advanced Channel Framework for Improved Underwater Acoustic Network Simulations  

E-Print Network [OSTI]

such as pollution, climate change and severe weather events is rapidly increasing. At the same time, as ocean underwater sensors, vehicles and devices together using acoustic communication. Network protocol development operation. However, acoustic communication performance is dynamic and dependent upon the environment

Zhou, Shengli

Note: This page contains sample records for the topic "acoustic doppler current" 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

Trapping and Frequency Variability in Electron Acoustic Waves  

E-Print Network [OSTI]

Trapping and Frequency Variability in Electron Acoustic Waves C.F. Driscoll, F. Anderegg, D 92093 USA Abstract. Electron Acoustic Waves (EAWs) with a phase velocity less than twice the plasma Langmuir waves, and at large excitations resonance is observed over a broad range. Laser Induced

California at San Diego, University of

442

A decade of acoustic thermometry in the North Pacific Ocean  

E-Print Network [OSTI]

A decade of acoustic thermometry in the North Pacific Ocean B. D. Dushaw,1 P. F. Worcester,2 W. H of acoustic thermometry in the North Pacific Ocean, J. Geophys. Res., 114, C07021, doi:10.1029/2008JC005124. 1 of basin-scale heat content in the northeast Pacific Ocean were made using a broadband 133-Hz source

Frandsen, Jannette B.

443

Improving the Model Convective Storm Quantitative Precipitation Nowcasting by Assimilating State Variables Retrieved from Multiple-Doppler Radar Observations  

Science Journals Connector (OSTI)

This research combines an advanced multiple-Doppler radar synthesis technique with the thermodynamic retrieval method, originally proposed by Gal-Chen, and a moisture/temperature adjustment scheme, and formulates a sequential procedure. The focus ...

Yu-Chieng Liou; Jian-Luen Chiou; Wei-Hao Chen; Hsin-Yu Yu

2014-11-01T23:59:59.000Z

444

A study of radial-flow turbomachinery blade vibration measurements using Eulerian laser Doppler vibrometry  

Science Journals Connector (OSTI)

The structural integrity of blades is critical to the health of turbomachinery. Since operational failure of these blades can possibly lead to catastrophic failure of the machine it is important to have knowledge of blade conditions in an online fashion. Due to several practical implications it is desired to measure blade vibration with a non-contact technique. The application of laser Doppler vibrometry towards the vibration based condition monitoring of axial-flow turbomachinery blades has been successfully demonstrated in previous work. In this paper the feasibility of using laser Doppler vibrometry to measure radial-flow turbomachinery blade vibrations is investigated with the aid of digital image correlation and strain gauge telemetry.

2014-01-01T23:59:59.000Z

445

Impact of the Doppler Broadened Double Differential Cross Section on Observed Resonance Profiles  

Science Journals Connector (OSTI)

Abstract This paper is sequential to studies discussing with the impact of the Doppler broadening of the Double Differential Cross Section (DDXS) on nuclear reactor core calculations. In this study, the influence of the resonance dependent DDXS on the observed resonance line shape in time of flight capture experiments is investigated. The importance of the correct formalism is illustrated by comparing Monte Carlo simulations with and without a resonance dependent DDXS model to measured data of a saturated 238U resonance. The resonance dependent DDXS is taken into account via its stochastic implementation known as Doppler Broadening Rejection Correction (DBRC). In addition, the increased impact of the resonance dependent DDXS model for higher temperatures is shown via a simulation of capture yields for 238U and 183W at different sample temperatures.

R. Dagan; B. Becker; Y. Danon; F. Gunsing; S. Kopecky; C. Lampoudis; O. Litaize; M. Moxon; P. Schillebeeckx

2014-01-01T23:59:59.000Z

446

On the role of spectral resolution in velocity shear layer measurements by Doppler reflectometry  

SciTech Connect (OSTI)

The signal quality of a Doppler reflectometer depends strongly on its spectral resolution, which is influenced by the microwave beam properties and the radius of curvature of the cutoff layer in the plasma. If measured close to a strong perpendicular velocity shear layer, the spectrum of the backscattered signal is influenced by different velocities. This can give rise to two Doppler shifted peaks in the spectrum as observed in TJ-II H-mode plasmas. It is shown by two-dimensional full wave simulations that the two peaks are separable provided the spectral resolution of the system is sufficient. However, if the spectral resolution is poor, the two peaks blend into one and yield an intermediate and incorrect velocity.

Happel, T.; Blanco, E.; Estrada, T. [Laboratorio Nacional de Fusion, Association Euratom-Ciemat, 28040 Madrid (Spain)

2010-10-15T23:59:59.000Z

447

Doppler Effects from Bending of Light Rays in Curved Space-Times  

E-Print Network [OSTI]

We study Doppler effects in curved space-time, i.e. the frequency shifts induced on electromagnetic signals propagating in the gravitational field. In particular, we focus on the frequency shift due to the bending of light rays in weak gravitational fields. We consider, using the PPN formalism, the gravitational field of an axially symmetric distribution of mass. The zeroth order, i.e. the sphere, is studied then passing to the contribution of the quadrupole moment, and finally to the case of a rotating source. We give numerical estimates for situations of physical interest, and by a very preliminary analysis, we argue that analyzing the Doppler effect could lead, in principle, in the foreseeable future, to the measurement of the quadrupole moment of the giant planets of the Solar System.

Matteo Luca Ruggiero; Angelo Tartaglia; Lorenzo Iorio

2006-05-06T23:59:59.000Z

448

Doppler- and recoil-free laser excitation of Rydberg states via three-photon transitions  

SciTech Connect (OSTI)

Three-photon laser excitation of Rydberg states by three different laser beams can be arranged in a starlike geometry that simultaneously eliminates the recoil effect and Doppler broadening. Our analytical and numerical calculations for a particular laser excitation scheme 5S{sub 1/2}{yields}5P{sub 3/2}{yields}6S{sub 1/2}{yields}nP in Rb atoms have shown that, compared to the one- and two-photon laser excitation, this approach provides much narrower linewidth and longer coherence time for both cold atom samples and hot vapors, if the intermediate one-photon resonances of the three-photon transition are detuned by more than respective single-photon Doppler widths. This method can be used to improve fidelity of Rydberg quantum gates and precision of spectroscopic measurements in Rydberg atoms.

Ryabtsev, I. I.; Beterov, I. I.; Tretyakov, D. B.; Entin, V. M.; Yakshina, E. A. [A. V. Rzhanov Institute of Semiconductor Physics SB RAS, Prospekt Lavrentyeva 13, 630090 Novosibirsk (Russian Federation)

2011-11-15T23:59:59.000Z

449

Doppler cooling with coherent trains of laser pulses and a tunable velocity comb  

SciTech Connect (OSTI)

We explore the possibility of decelerating and Doppler cooling an ensemble of two-level atoms by a coherent train of short, nonoverlapping laser pulses. We derive analytical expressions for mechanical force exerted by the train. In frequency space the force pattern reflects the underlying frequency comb structure. The pattern depends strongly on the ratio of the atomic lifetime to the repetition time between the pulses and pulse area. For example, in the limit of short lifetimes, the frequency-space peaks of the optical force wash out. We propose to tune the carrier-envelope offset frequency to follow the Doppler-shifted detuning as atoms decelerate; this leads to compression of atomic velocity distribution about comb teeth and results in a ''velocity comb''--a series of narrow equidistant peaks in the velocity space.

Ilinova, Ekaterina; Ahmad, Mahmoud; Derevianko, Andrei [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States)

2011-09-15T23:59:59.000Z

450

Borehole-Wall Imaging with Acoustic and Optical Televiewers for  

Open Energy Info (EERE)

Borehole-Wall Imaging with Acoustic and Optical Televiewers for Borehole-Wall Imaging with Acoustic and Optical Televiewers for Fractured-Bedrock Aquifer Investigations Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Borehole-Wall Imaging with Acoustic and Optical Televiewers for Fractured-Bedrock Aquifer Investigations Abstract Imaging with acoustic and optical televiewers results in continuous and oriented 360 degree views of the borehole wall from which the character and orientation of lithologic and structural features can be defined for fractured-bedrock aquifer investigations. Fractures are more clearly defined under a wider range of conditions on acoustic images than on optical images including dark-colored rocks, cloudy borehole water, and coated borehole walls. However, optical images allow for the direct viewing

451

Building Energy Software Tools Directory: AcousticCalc  

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

AcousticCalc AcousticCalc Developed over the last decade, AcousticCalc helps designers predict sound levels at the room level from a distant sound source. The program uses the ASHRAE Handbook and ASHRAE's 1991 Algorithms for HVAC Acoustics handbook methods with the "Source-Path-Receiver" model. This easy-to-use Windows-based program allows a user to define and save unlimited number of sound sources, save and define unlimited number of sound "paths" (composed of long list of possible duct component types) and model the ceiling effect and three different models for room effect. AcousticCalc allows a user to import and export (share) sound sources, user-defined devices, terminal units, and duct silencers with other users. Easy-to-navigate "tree" modeling allows an unlimited number of sound

452

Generation of Sound Bullets with a Nonlinear Acoustic Lens  

E-Print Network [OSTI]

Acoustic lenses are employed in a variety of applications, from biomedical imaging and surgery, to defense systems, but their performance is limited by their linear operational envelope and complexity. Here we show a dramatic focusing effect and the generation of large amplitude, compact acoustic pulses (sound bullets) in solid and fluid media, enabled by a tunable, highly nonlinear acoustic lens. The lens consists of ordered arrays of granular chains. The amplitude, size and location of the sound bullets can be controlled by varying static pre-compression on the chains. We support our findings with theory, numerical simulations, and corroborate the results experimentally with photoelasticity measurements. Our nonlinear lens makes possible a qualitatively new way of generating high-energy acoustic pulses, enabling, for example, surgical control of acoustic energy.

Alessandro Spadoni; Chiara Daraio

2009-08-31T23:59:59.000Z

453

3-D laser Doppler velocimetry study of incompressible flow through an orifice plate  

E-Print Network [OSTI]

of Advisory Committee: Dr. Gerald Morrison Orifice meters are used extensively in the U. S. for the measurement of natural gas. Uncertainty of metering accuracy has resulted in an estimated 250 million dollars annually in mis-charges. This has led... to the need for basic research on orifice meters in an attempt to improve the accuracy of existing metering facilities. The objective of this present study was to use a 3-D LDV (laser Doppler velocimeter) to obtain detailed velocity and turbulence...

Panak, David Leo

2012-06-07T23:59:59.000Z

454

Doppler-Broadened Spectral Emission from the Turbulently Heated Plasma of Burnout V  

Science Journals Connector (OSTI)

In an efficient ion heating mode recently discovered in the Burnout-V turbulent-heating experiment, the line profiles of emission spectra exhibit three noteworthy features: (1) a marked Doppler broadening (full width at half-maximum ?10 Å) of the Balmer lines, (2) a "red"/"blue" asymmetry dependent on the geometry of the plasma container, and (3) non-Gaussian line shapes near the central wavelengths.

I. Alexeff; G. E. Guest; J. R. McNally; Jr.; R. V. Neidigh; F. R. Scott

1969-08-11T23:59:59.000Z

455

On the Doppler effect for light from orbiting sources in Kerr-type metrics  

E-Print Network [OSTI]

A formula is derived for the combined motional and gravitational Doppler effect in general stationary axisymmetric metrics for a photon emitted parallel or antiparallel to the assumed circular orbital motion of its source. The same formula is derived from eikonal approximation and Killing vector approaches to elucidate connections between observational astronomy and modern Relativity. The formula yields expected results in the limits of a moving or stationary source in the exterior Kerr and Schwarzschild metrics and a moving source in flat space.

S. Cisneros; G. Goedecke; C. Beetle; M. Engelhardt

2012-03-12T23:59:59.000Z

456

Synthetic Lorentz force in classical atomic gases via Doppler effect and radiation pressure  

E-Print Network [OSTI]

We theoretically predict a novel type of synthetic Lorentz force for classical (cold) atomic gases, which is based on the Doppler effect and radiation pressure. A fairly uniform and strong force can be constructed for gases in macroscopic volumes of several cubic millimeters and more. This opens the possibility to mimic classical charged gases in magnetic fields, such as those in a tokamak, in cold atom experiments.

Dub?ek, T; Juki?, D; Aumiler, D; Ban, T; Buljan, H

2014-01-01T23:59:59.000Z

457

Doppler effects of an oscillating line source in shear flow with a free surface  

Science Journals Connector (OSTI)

Abstract The linearised water-wave radiation problem for the oscillating 2D submerged source in an inviscid shear flow with a free surface is investigated analytically. There is a nonzero surface velocity. The depth is infinite and the vorticity is uniform. The amplitudes radiated from the source are calculated analytically. Due to Doppler effects, there may be up to four different emitted waves, and there is resonance with zero group velocity and infinite amplitude.

Peder A. Tyvand; Mikkel Elle Lepperød

2014-01-01T23:59:59.000Z

458

CONSTRAINING HIGH-SPEED WINDS IN EXOPLANET ATMOSPHERES THROUGH OBSERVATIONS OF ANOMALOUS DOPPLER SHIFTS DURING TRANSIT  

SciTech Connect (OSTI)

Three-dimensional (3D) dynamical models of hot Jupiter atmospheres predict very strong wind speeds. For tidally locked hot Jupiters, winds at high altitude in the planet's atmosphere advect heat from the day side to the cooler night side of the planet. Net wind speeds on the order of 1-10 km s{sup -1} directed towards the night side of the planet are predicted at mbar pressures, which is the approximate pressure level probed by transmission spectroscopy. These winds should result in an observed blueshift of spectral lines in transmission on the order of the wind speed. Indeed, Snellen et al. recently observed a 2 {+-} 1 km s{sup -1} blueshift of CO transmission features for HD 209458b, which has been interpreted as a detection of the day-to-night (substellar to anti-stellar) winds that have been predicted by 3D atmospheric dynamics modeling. Here, we present the results of a coupled 3D atmospheric dynamics and transmission spectrum model, which predicts the Doppler-shifted spectrum of a hot Jupiter during transit resulting from winds in the planet's atmosphere. We explore four different models for the hot Jupiter atmosphere using different prescriptions for atmospheric drag via interaction with planetary magnetic fields. We find that models with no magnetic drag produce net Doppler blueshifts in the transmission spectrum of {approx}2 km s{sup -1} and that lower Doppler shifts of {approx}1 km s{sup -1} are found for the higher drag cases, results consistent with-but not yet strongly constrained by-the Snellen et al. measurement. We additionally explore the possibility of recovering the average terminator wind speed as a function of altitude by measuring Doppler shifts of individual spectral lines and spatially resolving wind speeds across the leading and trailing terminators during ingress and egress.

Miller-Ricci Kempton, Eliza [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Rauscher, Emily, E-mail: ekempton@ucolick.org [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721 (United States)

2012-06-01T23:59:59.000Z

459

Methods and apparatus for measurement of the resistivity of geological formations from within cased wells in presence of acoustic and magnetic energy sources  

DOE Patents [OSTI]

Methods and apparatus are provided for measuring the acoustically modulated electronic properties of geological formations and cement layers adjacent to cased boreholes. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. Voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the leakage current conducted into formation in the vicinity of those electrodes. Simultaneously subjecting the casing and formation to an acoustic source acoustically modulates the leakage current measured thereby providing a measure of the acoustically modulated electronic properties of the adjacent formation. Similarly, methods and apparatus are also described which measure the leakage current into formation while simultaneously subjecting the casing to an applied magnetic field which therefore allows measurement of the magnetically modulated electronic properties of the casing and the adjacent formation.

Vail, III, William B. (Bothell, WA)

1991-01-01T23:59:59.000Z

460

Early Detection of Steel Rebar Corrosion by Acoustic Emission Monitoring Early Detection of Steel Rebar Corrosion by Acoustic Emission  

E-Print Network [OSTI]

Early Detection of Steel Rebar Corrosion by Acoustic Emission Monitoring Early Detection of Steel Rebar Corrosion by Acoustic Emission Monitoring Alan D. Zdunek and David Prine BIRL Industrial Research, Evanston, IL 60201 Paper No. 547 presented at CORROSION95, the NACE International Annual Conference

Note: This page contains sample records for the topic "acoustic doppler current" 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

Doppler Effect in Spectra of Positive Rays of Uniform Velocity in Argon, Neon, Helium  

Science Journals Connector (OSTI)

Ions of argon, neon, helium, formed in a low voltage arc have been accelerated to high speeds in a short electric field, forming beams of positive ions which all have the same energy. The spectra of the beams of positive rays of uniform energy observed in the direction of motion show a characteristic Doppler effect, with displaced lines fully as sharp as the rest lines. With the exception of the very intense ?3418 of neon, the arc lines of argon and neon have no Doppler effect, while the lines of the first spark spectrum are accompanied by sharp displaced lines only slightly less intense than the rest lines, whose separation corresponds accurately to the speeds acquired by singly charged ions in the accelerating field, for velocities 9000 to 28,000 volts and several lines of higher spark spectra were observed with displaced lines also corresponding to singly charged ions. Satisfactory observations are made at pressure about 5×10-3 mm, the intensity and sharpness of the displaced lines diminishing with increasing pressure. In helium, the arc lines show relatively faint displaced lines corresponding to singly charged ions; one spark line ?4686 was accompanied by a relatively intense displaced line, while the only other spark line observed, ?4541, had no Doppler effect.

Anna I. McPherson

1933-11-01T23:59:59.000Z

462

Linear and nonlinear light propagations in a Doppler-broadened medium via electromagnetically induced transparency  

SciTech Connect (OSTI)

We present a systematic theoretical study to deal with linear and nonlinear light propagations in a Doppler-broadened three-level {Lambda} system via electromagnetically induced transparency (EIT), with incoherent population exchange between two lower energy levels taken into account. Through a careful analysis of base state and linear excitation, we show that the EIT condition of the system is given by |{Omega}{sub c}|{sup 2{gamma}}{sub 31}>>2{gamma}{sub 21{Delta}{omega}D}{sup 2}, where {Omega}{sub c} is half the Rabi frequency of the control field, {Delta}{omega}{sub D} is the Doppler width, and {gamma}{sub jl} is the decay rate of the coherence between states |j> and |l>. Under this condition, the effect of incoherent population exchange is insignificant, while dephasing dominates the decoherence of the system. This condition also ensures the validity of the weak nonlinear perturbation theory used in this work for solving the Maxwell-Bloch equations with inhomogeneous broadening. We then investigate the nonlinear propagation of the probe field and show that it is possible to form temporal optical solitons in the Doppler-broadened medium. Such solitons have ultraslow propagating velocity and can be generated in very low light power. The possibility of realizing (1+1)-dimensional and (2+1)-dimensional spatial optical solitons in the adiabatic regime of the system is also discussed.

Li Liang; Huang Guoxiang [Department of Physics and Institute of Theoretical Physics, East China Normal University, Shanghai 200062 (China); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China and Institute of Nonlinear Physics, Zhejiang Normal University, Zhejiang 321004 (China)

2010-08-15T23:59:59.000Z

463

Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media  

DOE Patents [OSTI]

Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.

Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)

1999-01-01T23:59:59.000Z

464

Improved algorithms for the calculation of resolved resonance cross sections with applications to the structural Doppler effect in fast reactors  

SciTech Connect (OSTI)

Motivated by a need for an economical yet rigorous tool which can address the computation of the structural material Doppler effect, an extremely efficient improved RABANL capability has been developed utilizing the fact that the Doppler broadened line shape functions become essentially identical to the natural line shape functions or Lorentzian limits beyond about 100 Doppler widths from the resonance energy, or when the natural width exceeds about 200 Doppler widths. The computational efficiency has been further enhanced by preprocessing or screening a significant number of selected resonances during library preparation into composition and temperature independent smooth background cross sections. The resonances which are suitable for such pre-processing are those which are either very broad or those which are very weak. The former contribute very little to the Doppler effect and their self-shielding effect can readily be averaged into slowly varying background cross section data, while the latter contribute very little to either the Doppler or to self-shielding effects. To illustrate the accuracy and efficiency of the improved RABANL algorithms and resonance screening techniques, calculations have been performed for two systems, the first with a composition typical of the STF converter region and the second typical of an LMFBR core composition. Excellent agreement has been found for RABANL compared to the reference Monte Carlo solution obtained using the code VIM, and improved results have also been obtained for the narrow resonance approximation in the ultra-fine-group option of MC/sup 2/-2.

Hwang, R.N.; Toppel, B.J.; Henryson, H. II

1980-10-01T23:59:59.000Z

465

Current Solicitations - Hanford Site  

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

Home Prime Contracts Current Solicitations Small Business Other Sources DOE RL Contracting Officers DOE RL Contracting Officer Representatives Current Solicitations Email...

466

Study of the Acoustic Effects of Hydrokinetic Tidal Turbines in Admiralty Inlet, Puget Sound  

SciTech Connect (OSTI)

Hydrokinetic turbines will be a source of noise in the marine environment - both during operation and during installation/removal. High intensity sound can cause injury or behavioral changes in marine mammals and may also affect fish and invertebrates. These noise effects are, however, highly dependent on the individual marine animals; the intensity, frequency, and duration of the sound; and context in which the sound is received. In other words, production of sound is a necessary, but not sufficient, condition for an environmental impact. At a workshop on the environmental effects of tidal energy development, experts identified sound produced by turbines as an area of potentially significant impact, but also high uncertainty. The overall objectives of this project are to improve our understanding of the potential acoustic effects of tidal turbines by: (1) Characterizing sources of existing underwater noise; (2) Assessing the effectiveness of monitoring technologies to characterize underwater noise and marine mammal responsiveness to noise; (3) Evaluating the sound profile of an operating tidal turbine; and (4) Studying the effect of turbine sound on surrogate species in a laboratory environment. This study focuses on a specific case study for tidal energy development in Admiralty Inlet, Puget Sound, Washington (USA), but the methodologies and results are applicable to other turbine technologies and geographic locations. The project succeeded in achieving the above objectives and, in doing so, substantially contributed to the body of knowledge around the acoustic effects of tidal energy development in several ways: (1) Through collection of data from Admiralty Inlet, established the sources of sound generated by strong currents (mobilizations of sediment and gravel) and determined that low-frequency sound recorded during periods of strong currents is non-propagating pseudo-sound. This helped to advance the debate within the marine and hydrokinetics acoustic community as to whether strong currents produce propagating sound. (2) Analyzed data collected from a tidal turbine operating at the European Marine Energy Center to develop a profile of turbine sound and developed a framework to evaluate the acoustic effects of deploying similar devices in other locations. This framework has been applied to Public Utility District No. 1 of Snohomish Country's demonstration project in Admiralty Inlet to inform postinstallation acoustic and marine mammal monitoring plans. (3) Demonstrated passive acoustic techniques to characterize the ambient noise environment at tidal energy sites (fixed, long-term observations recommended) and characterize the sound from anthropogenic sources (drifting, short-term observations recommended). (4) Demonstrated the utility and limitations of instrumentation, including bottom mounted instrumentation packages, infrared cameras, and vessel monitoring systems. In doing so, also demonstrated how this type of comprehensive information is needed to interpret observations from each instrument (e.g., hydrophone data can be combined with vessel tracking data to evaluate the contribution of vessel sound to ambient noise). (5) Conducted a study that suggests harbor porpoise in Admiralty Inlet may be habituated to high levels of ambient noise due to omnipresent vessel traffic. The inability to detect behavioral changes associated with a high intensity source of opportunity (passenger ferry) has informed the approach for post-installation marine mammal monitoring. (6) Conducted laboratory exposure experiments of juvenile Chinook salmon and showed that exposure to a worse than worst case acoustic dose of turbine sound does not result in changes to hearing thresholds or biologically significant tissue damage. Collectively, this means that Chinook salmon may be at a relatively low risk of injury from sound produced by tidal turbines located in or near their migration path. In achieving these accomplishments, the project has significantly advanced the District's goals of developing a demonstration-scale tidal energy proj

Brian Polagye; Jim Thomson; Chris Bassett; Jason Wood; Dom Tollit; Robert Cavagnaro; Andrea Copping

2012-03-30T23:59:59.000Z

467

Acoustic signatures: From natural to systems science  

Science Journals Connector (OSTI)

The interest in acoustic signatures began with the problem of detecting cracks in railroad wheels. When a wheel is struck with a hammer it produces a sound like that of a bell. If the wheel is cracked it sounds dissonant and muffled. By comparing sounds from the two members of a wheelset a measure of the difference in their mechanical properties is obtained. A fully automatic system was developed and installed on a Southern Pacific track in the 1980’s. The story of this undertaking is an object lesson in systems science. Recently beams have been used as test objects in an attempt to resolve certain basic questions in the science of the acoustic monitoring method. These questions will be illustrated with results from a test fixture with various beams. The limitation of the vibration monitoring method is that other conditions such as uncertainties in the geometry of the test object its surface conditions and loading can also affect the vibration response and it is necessary to distinguish the effects due to harmful conditions from those due to harmless ones. The sensitivity of the method is thus determined by the need to make this distinction. [Work supported by NSF Grant No. MSS?9024224.

Robert D. Finch; Ben H. Jansen

1993-01-01T23:59:59.000Z

468

Acoustic emission before avalanches in granular media  

Science Journals Connector (OSTI)

Avalanches of granular media are mainly characterized by the observation and the measurement of the main angles of avalanche corresponding first to the movement of isolated beads and to the whole movement of a great part of the grains. These characterisations do not give any information about the rearrangements of the grains inside the layer of granular beads. As any movement of a grain produces a deformation of the structure it is quite normal to expect for a sound that will propagate inside the granular medium. We present an experimental study of the precursors of avalanches on spherical granular glass beads and silica aerogels in powder (size of grains less than 80 micrometers). Acoustic emission has been recorded with two piezoelectric transducers placed on the lower part of the material layer. Our results show clearly that before any movement on the upper part of the beads layer so for an angle less than the first angle of avalanche movements inside the material produce pulsed sounds that can be recorded. Theses vibrating events are occurring more and more when the angle is increasing until the first angle of avalanche where acoustic emission becomes intense.

Vincent Gibiat; Eric Plazza; Pierre De Guibert

2008-01-01T23:59:59.000Z

469

Acoustic and seismic measurement of ice processes  

Science Journals Connector (OSTI)

As sea ice responds to environmental forcing it deforms leading to the storage of strain energy. When mechanical failure occurs most of this energy is dissipated through fracturing but a small portion radiates as seismic and acoustic waves. These waves provide useful signals for sensing the failure process in the ice. In a recent ice mechanics experiment conducted north of Prudhoe Bay (SIMI ’94) a large number of ice failure events were observed using geophone and hydrophone arrays. Preliminary results are presented including a large?scale tensile fracture test and naturally occurring sounds near a closing lead. For the artificial fracture the acoustic signals allow determination of cracking rate fracture advance and crack propagation velocities. The overall crack propagation speed is estimated to be of order 50 m?s?1; maximum cracking activities occur prior to peak loading. In the second data set the naturally occurring stick?slip process was observed as two ice sheets moved against each other in a closing lead. A wide range of frequencies can occur simultaneously representing different components of the sliding and slipping mechanisms.

David M. Farmer; Yunbo Xie

1995-01-01T23:59:59.000Z

470

Geographically distributed acoustical monitoring of migrating birds  

Science Journals Connector (OSTI)

A geographically distributed system of largely automated acoustical monitoring stations was developed to monitor the migration of small passerine birds. The targeted species wood warblers and sparrows migrate at night and produce short (about 120 ms at the longest) high?pitched (between roughly 6 and 10 kHz) calls as they fly often audible from the ground. The monitoring system consisted of ten stations located in New Jersey Maryland Pennsylvania and New York and a central data repository located at the Cornell Lab of Ornithology. Each station comprised an outdoor weatherproof microphone connected to a volunteer’s home computer. The computer automatically ran acoustic transient detection software each night that listened continuously to the microphone signal and extracted all transients matching certain criteria each to its own audio file. The detected transients were uploaded by the volunteer each morning via the Internet to the central repository for classification and archival. Results including spectrograms of all detected transients and bird call counts were displayed on a public web site updated daily. [Work supported by EPA.

2000-01-01T23:59:59.000Z

471

Improved efficiency of an acoustic parametric source  

Science Journals Connector (OSTI)

In the customary design of an acoustic parametric source a primary signal consisting of two high–frequency wave components is projected into the water. Because of the inherent nonlinearity of acoustic propagation the two primary components mix to form a wave at the difference frequency. This paper describes how one can increase the parametric conversion of energy into the difference–frequency beam through the use of primary signals other than the two–component signal described above. For example another primary signal one might use consists of a sinusoidal carrier wave undergoing amplitude modulation. Use of such an AM primary signal with 100% modulation leads to a predicted difference–frequency pressure amplitude that is 2.5 dB greater than the corresponding amplitude obtained with a two–component primary signal of the same total input power. This prediction shows approximate agreement with a measured increase of 2.1 dB. For a primary signal consisting of N components theory predicts an increase in difference–frequency level that approaches 6 dB as an upper limit.

Anthony I. Eller

1974-01-01T23:59:59.000Z

472

Helioseismology in a bottle: modal acoustic velocimetry  

E-Print Network [OSTI]

Measurement of the differential rotation of the Sun's interior is one of the great achievements of helioseismology, providing important constraints for stellar physics. The technique relies on observing and analyzing rotationally-induced splittings of p-modes in the star. Here we demonstrate the first use of the technique in a laboratory setting. We apply it in a spherical cavity with a spinning central core (spherical-Couette flow) to determine the mean azimuthal velocity of the air filling the cavity. We excite a number of acoustic resonances (analogous to p-modes in the Sun) using a speaker and record the response with an array of small microphones on the outer sphere. Many observed acoustic modes show rotationally-induced splittings, which allow us to perform an inversion to determine the air's azimuthal velocity as a function of both radius and latitude. We validate the method by comparing the velocity field obtained through inversion against the velocity profile measured with a calibrated hot film anemo...

Triana, Santiago Andrés; Nataf, Henri-Claude; Thorette, Aurélien; Lekic, Vedran; Lathrop, Daniel P

2014-01-01T23:59:59.000Z

473

Effect of a co?flowing annular outer flow on the flow and acoustics in a porous tube.  

Science Journals Connector (OSTI)

One of the most important aspects of flow in a gas turbine combustor is the cooling airflow introduced through the combustor liner. The co?flowing annular cooling air affects the flow and the acoustic field of the main combustor. A generic study is in progress to study the effect of a co?flowing annular outer flow on the flow and acoustics in a porous tube. This work is an idealization of the actual gas turbine combustor flow. The results generated here will be used to validate the computational codes currently being used by the gas turbine industry to calculate these flow fields. In the present experimental work a 6?in.?diam tube made out of perforated sheet is located coaxially in an 8?in.?diam outer tube. Airflows in the inner perforated tube as well as in the annular space between the two tubes. Detailed measurements of the turbulence structure using hot wire anemometry and of the acoustic field using microphonetransducers are being made. Effects of parameters such as porosity of the tube relative areas of annular space and cross section of inner tube and flow Reynolds number on the turbulence quantities and the acoustic field will be reported.

Sundar Ramamoorthy; Fariborz Khodabakhsh; Sastry Munukutla

1992-01-01T23:59:59.000Z

474

Current to Current Corporation | Open Energy Information  

Open Energy Info (EERE)

to Current Corporation to Current Corporation Jump to: navigation, search Name Current to Current Corporation Place Burlington, Massachusetts Zip 1803 Sector Ocean Product Developing a technology which generates power from ocean currents : Submersible Power Generators (SPG). Coordinates 44.446275°, -108.431704° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.446275,"lon":-108.431704,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

475

ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS  

SciTech Connect (OSTI)

During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.

Chiswell, S.; Buckley, R.

2009-01-15T23:59:59.000Z

476

Scientific Solutions (TRL 5 6 Component)- Underwater Active Acoustic Monitoring Network for Marine and Hydrokinetic Energy  

Broader source: Energy.gov [DOE]

Scientific Solutions (TRL 5 6 Component) - Underwater Active Acoustic Monitoring Network for Marine and Hydrokinetic Energy

477

E-Print Network 3.0 - acoustic waves propagating Sample Search...  

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

propagating Search Powered by Explorit Topic List Advanced Search Sample search results for: acoustic waves propagating...

478

E-Print Network 3.0 - acoustic waves propagation Sample Search...  

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

propagation Search Powered by Explorit Topic List Advanced Search Sample search results for: acoustic waves propagation...

479

3D acoustic imaging applied to the Baikal Neutrino Telescope  

E-Print Network [OSTI]

A hydro-acoustic imaging system was tested in a pilot study on distant localization of elements of the Baikal underwater neutrino telescope. For this innovative approach, based on broad band acoustic echo signals and strictly avoiding any active acoustic elements on the telescope, the imaging system was temporarily installed just below the ice surface, while the telescope stayed in its standard position at 1100 m depth. The system comprised an antenna with four acoustic projectors positioned at the corners of a 50 meter square; acoustic pulses were "linear sweep-spread signals" - multiple-modulated wide-band signals (10-22 kHz) of 51.2 s duration. Three large objects (two string buoys and the central electronics module) were localized by the 3D acoustic imaging, with a accuracy of ~0.2 m (along the beam) and ~1.0 m (transverse). We discuss signal forms and parameters necessary for improved 3D acoustic imaging of the telescope, and suggest a layout of a possible stationary bottom based 3D imaging setup. The presented technique may be of interest for neutrino telescopes of km3-scale and beyond, as a flexible temporary or as a stationary tool to localize basic telescope elements, while these are completely passive.

K. G. Kebkal; R. Bannasch; O. G. Kebkal; A. I. Panfilov; R. Wischnewski

2008-11-07T23:59:59.000Z

480

Supernova and baryon acoustic oscillation constraints on (new) polynomial dark energy parametrizations: current results and forecasts  

Science Journals Connector (OSTI)

......knowledge of dark energy. In Percival (2010),3 a survey is proposed...forthcoming surveys to describe...features of dark energy. 5CONCLUSIONS...that future surveys will decrease...ignorance about dark energy evolution considerably......

Irene Sendra; Ruth Lazkoz

2012-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "acoustic doppler current" 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.


481

Deep Water Bottom-Track Ship's Velocities from an Acoustic Correlation Current Profiler  

E-Print Network [OSTI]

.0038, a regression coefficient squared of 0.9975 and a zero intercept of 2.8 cm s-1. There was no correlation between

Griffiths, Gwyn

482

Supernova and baryon acoustic oscillation constraints on (new) polynomial dark energy parametrizations: current results and forecasts  

Science Journals Connector (OSTI)

......Wang (2008), where a new dark energy description in terms of...Ruiz-Lapuente P., ed., Dark Energy. Cambridge Univ. Press...Regression, 1st edn. Wiley, New York. Efstathiou G. , Bond...Am. Inst. Phys., New York, p.21. McDonald P......

Irene Sendra; Ruth Lazkoz

2012-05-01T23:59:59.000Z

483

Augmentation of acoustic transmission by a transition layer  

Science Journals Connector (OSTI)

It has already been reported by the author at a previous meeting [J. Acoust. Soc. Am. Suppl. 73 S95 (1982)] that certain types of transition layers can improve the transmission of acoustic waves from one medium to another. In this paper conditions under which the transmissions of an acoustic wave is enhanced by the transition layer are presented. The case of a finite thickness elastic layer has been studied and it has been determined that at certain key frequencies an optimum transition layer thickness exists which greatly improves the interaction between the two media.

Mauro Pierucci

1985-01-01T23:59:59.000Z

484

Acoustic pursuit of invisible moving targets by cats  

Science Journals Connector (OSTI)

Head movements evoked by an invisible acoustic target were used as a metric to analyze localization of moving sources of sound in naive cats. The target was presented in the lateral sound field and moved along an arc at constant angular speeds. Head-movement trajectories were characterized by a large-magnitude orienting component that undershot the target and a tracking component elicited by the target during acoustic pursuit. The tracking component was characterized by a succession of stepwise head movements that maintained a relatively close alignment of the median plane of the head with the moving acoustic target.

Ralph E. Beitel

1999-01-01T23:59:59.000Z

485

Simultaneous acoustic and microwave backscattering from the sea surface  

Science Journals Connector (OSTI)

Simultaneous and coincident measurements of acoustic and microwavebackscatter from the air/sea interface were obtained during Phase II of the SAXON-FPN experiment in December 1992 and again in March 1993. The acoustic and microwave grazing angles were both set to 17° and the wavelengths were matched being set to 2.14 3.00 and 5.66 cm corresponding to respectively acoustic frequencies of 26.5 50 and 70 kHz and microwave frequencies of 5.3 10 and 14 GHz. Backscattering cross sections normalized by ensonified area for the acoustic (? 0 a ) and microwave (? 0 m ) returns were determined and their dependence on wind speed was investigated. The acoustic scattering strength is defined as 10? log 10 (? 0 a ) and the microwavescattering strength is defined as 10? log 10 (? 0 m )?10? log 10 (4?). The results of these experiments show that the two scattering strengths are comparable at wind speeds below about 3 m/s but that the acoustic scattering strength increases much faster than the microwavescattering strength with increasing wind speed until reaching saturation. If these wind-speed dependencies are represented by a power law U n then n is 5–6 for ? 0 a and 2–4 for ? 0 m for wind speeds between 2 and 7 m/s. This difference is ascribed to the effect of bubbles on the acoustic backscatter. The more rapid increase of ? 0 a compared to ? 0 m implies that for our 17° grazing angle acoustic scattering from the surface is negligible at all but the lowest wind speeds. Therefore a simple model is used for bubble scattering to fit the acoustic data as a function of wind speed for all three acoustic frequencies. The bubble densities required to fit the data agree well with previous measurements of near-surface bubble distributions. The model predicts an overshoot of the acoustic scattering strength (above the saturation level) at moderate wind speeds which is clearly seen in the data at 26.5 and 70 kHz. Finally a composite surface scatteringmodel is utilized for the pure surface scattering component along with the bubble model to predict the wind-speed dependence of the acoustic scattering strength at a 45° grazing angle and compare the results with earlier measurements.

Peter H. Dahl; William J. Plant; Bernd Nützel; Anke Schmidt; Heinz Herwig; Eugene A. Terray

1997-01-01T23:59:59.000Z

486

Study of maximizing acoustic energy coupling to salt  

E-Print Network [OSTI]

STUDY OF MAXIMIZING ACOUSTIC ENERGY COUPLING TO SALT A Thesis by YNG-JOV HNANG Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1979 Major... Subject: Geophysics STUDY OF &MAXIMIZING ACOUSTIC ENERGY COUPLING TO SALT A Thesis by YNG-JOU HWANG Approved as to style and content by: C arrman o ommit e em er em e er Hea o epartment December 1979 ABSTRACT Study of Haximizing Acoustic Energy...

Hwang, Yng-Jou

2012-06-07T23:59:59.000Z

487

Electromechanical transducer for acoustic telemetry system  

DOE Patents [OSTI]

An improved electromechanical transducer is provided for use in an acoustic telemetry system. The transducer of this invention comprises a stack of ferroelectric ceramic disks interleaved with a plurality of spaced electrodes which are used to electrically pole the ceramic disks. The ceramic stack is housed in a metal tubular drill collar segment. The electrodes are preferably alternatively connected to ground potential and driving potential. This alternating connection of electrodes to ground and driving potential subjects each disk to an equal electric field; and the direction of the field alternates to match the alternating direction of polarization of the ceramic disks. Preferably, a thin metal foil is sandwiched between electrodes to facilitate the electrical connection. Alternatively, a thicker metal spacer plate is selectively used in place of the metal foil in order to promote thermal cooling of the ceramic stack.

Drumheller, Douglas S. (Cedar Crest, NM)

1993-01-01T23:59:59.000Z

488

Wax Point Determinations Using Acoustic Resonance Spectroscopy  

SciTech Connect (OSTI)

The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, FL. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed.

Jubin, R.T.

2002-04-08T23:59:59.000Z

489

Acoustic nonlinearity in fluorinert FC-43  

SciTech Connect (OSTI)

Fluorinert FC-43 nonlinearity was investigated using two approaches: (i) a finite amplitude method with harmonic production; and (ii) a nonlinear frequency mixing in the fluid with consequent beam profile measurement of the difference frequency. The finite amplitude method provides information on the coefficient of nonlinearity, {beta}, through the amplitudes of the fundamental and the second harmonic, at a certain transmitter-receiver distance. A calibrated hydrophone was used as a receiver, in order to obtain direct pressure measurements of the acoustic waves in the fluid. The role of transmitter-receiver distance in {beta} determination is investigated. In the second approach, a single transducer is used to provide two high-frequency beams. The collinear high-frequency beams mix nonlinearly in the fluid resulting in a difference frequency beam and higher order harmonics of the primaries. The difference frequency beam profite is investigated at lengths beyond the mixing distance. The experimental data are compured with the KZK theory.

Pantea, Cristian [Los Alamos National Laboratory; Sinha, Dipen N [Los Alamos National Laboratory; Osterhoudt, Curtis F [Los Alamos National Laboratory; Mombourquette, Paul C [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

490

Acoustic sand detector for fluid flowstreams  

DOE Patents [OSTI]

The particle volume and particle mass production rate of particulate solids entrained in fluid flowstreams such as formation sand or fracture proppant entrained in oil and gas production flowstreams is determined by a system having a metal probe interposed in a flow conduit for transmitting acoustic emissions created by particles impacting the probe to a sensor and signal processing circuit which produces discrete signals related to the impact of each of the particles striking the probe. The volume or mass flow rate of particulates is determined from making an initial particle size distribution and particle energy distribution and comparing the initial energy distribution and/or the initial size distribution with values related to the impact energies of a predetermined number of recorded impacts. The comparison is also used to recalibrate the system to compensate for changes in flow velocity.

Beattie, Alan G. (Corrales, NM); Bohon, W. Mark (Frisco, TX)

1993-01-01T23:59:59.000Z

491

Collisional damping of the geodesic acoustic mode  

SciTech Connect (OSTI)

The frequency and damping rate of the geodesic acoustic mode (GAM) is revisited by using a gyrokinetic model with a number-conserving Krook collision operator. It is found that the damping rate of the GAM is non-monotonic as the collision rate increases. At low ion collision rate, the damping rate increases linearly with the collision rate; while as the ion collision rate is higher than v{sub ti}/R, where v{sub ti} and R are the ion thermal velocity and major radius, the damping rate decays with an increasing collision rate. At the same time, as the collision rate increases, the GAM frequency decreases from the (7/4+{tau})v{sub ti}/R to (1+{tau})v{sub ti}/R, where {tau} is the ratio of electron temperature to ion temperature.

Gao Zhe [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)

2013-03-15T23:59:59.000Z

492

Raising Photoemission Efficiency with Surface Acoustic Waves  

SciTech Connect (OSTI)

We are developing a novel technique that may help increase the efficiency and reduce costs of photoelectron sources used at electron accelerators. The technique is based on the use of Surface Acoustic Waves (SAW) in piezoelectric materials, such as GaAs, that are commonly used as photocathodes. Piezoelectric fields produced by the traveling SAW spatially separate electrons and holes, reducing their probability of recombination, thereby enhancing the photoemission quantum efficiency of the photocathode. Additional advantages could be increased polarization provided by the enhanced mobility of charge carriers that can be controlled by the SAW and the ionization of optically-generated excitons resulting in the creation of additional electron-hole pairs. It is expected that these novel features will reduce the cost of accelerator operation. A theoretical model for photoemission in the presence of SAW has been developed, and experimental tests of the technique are underway.

A. Afanasev, F. Hassani, C.E. Korman, V.G. Dudnikov, R.P. Johnson, M. Poelker, K.E.L. Surles-Law

2012-07-01T23:59:59.000Z

493

Current Projects | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Current Current Projects Ames Site Office (AMSO) AMSO Home About Current Projects Contract Management Environment, Safety and Health (ES&H) Resources Contact Information Ames Site Office U.S. Department of Energy 9800 S. Cass Avenue Argonne, IL 60439 P: (630) 252-6167 F: (630) 252-2855 Current Projects Print Text Size: A A A RSS Feeds FeedbackShare Page Ames Laboratory Sensitive Instrument Facility Project Description This project will construct a Sensitive Instrument Facility (SIF) that will provide six instrument bays, sample preparation space, control rooms, and staff support space. The instrument bays will provide vibration isolation, acoustic separation and control, electromagnetic interference (EMI) control, strict control of air flow and strict ambient temperature and

494

LANSCE beam current limiter  

SciTech Connect (OSTI)

The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described.

Gallegos, F.R.

1996-06-01T23:59:59.000Z

495

Implementation and evaluation of a two-dimensional laser doppler vibrometer system for non-contact monitoring of external stress loading of aluminum samples.  

E-Print Network [OSTI]

??This thesis details the development and validation of a laser Doppler vibrometer-based measurement system that is capable of quantifying not only the normal vibration of… (more)

Langston, Paul Wesley

2009-01-01T23:59:59.000Z

496

Anomalous - viscosity current drive  

DOE Patents [OSTI]

An apparatus and method for maintaining a steady-state current in a toroidal magnetically confined plasma. An electric current is generated in an edge region at or near the outermost good magnetic surface of the toroidal plasma. The edge current is generated in a direction parallel to the flow of current in the main plasma and such that its current density is greater than the average density of the main plasma current. The current flow in the edge region is maintained in a direction parallel to the main current for a period of one or two of its characteristic decay times. Current from the edge region will penetrate radially into the plasma and augment the main plasma current through the mechanism of anomalous viscosity. In another aspect of the invention, current flow driven between a cathode and an anode is used to establish a start-up plasma current. The plasma-current channel is magnetically detached from the electrodes, leaving a plasma magnetically insulated from contact with any material obstructions including the cathode and anode.

Stix, Thomas H. (Princeton, NJ); Ono, Masayuki (Princeton Junction, NJ)

1988-01-01T23:59:59.000Z

497

High-Current Accelerators  

E-Print Network [OSTI]

F i g . 13 F i g . 14 A 48 ACCELERATOR F i g . 25 F i g . 16supply. Extrapolation of accelerator energy and current9 . A-48 high-current accelerator, low-velocity end. Fig.

Lawrence, Ernest O.

1955-01-01T23:59:59.000Z

498

Acoustic Logs At Coso Geothermal Area (1977) | Open Energy Information  

Open Energy Info (EERE)

Coso Geothermal Area (1977) Coso Geothermal Area (1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Acoustic Logs At Coso Geothermal Area (1977) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Acoustic Logs Activity Date 1977 Usefulness not indicated DOE-funding Unknown Notes Acoustic logs indicate fractured rock and potentially permeable zones. References Galbraith, R. M. (1 May 1978) Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Goranson, C.; Schroeder, R. (1 June 1978) Static downhole characteristics of well CGEH-1 at Coso Hot Springs, China Lake, California Retrieved from "http://en.openei.org/w/index.php?title=Acoustic_Logs_At_Coso_Geothermal_Area_(1977)&oldid=510216"

499

On acoustic cavitation of slightly subcritical bubbles Anthony Harkin  

E-Print Network [OSTI]

On acoustic cavitation of slightly subcritical bubbles Anthony Harkin Department of Mathematics, such as submicron air bubbles in water, where the natural oscilla- tion frequencies are high. In contrast, when

Kaper, Tasso J.

500

Acoustic radiation from a plate with sinusoidally varying properties  

Science Journals Connector (OSTI)

The acoustic radiation produced by an infinite flat plate with sinusoidally varying properties and driven by a distributed load is presented. The plate is assumed to be thin with constant thickness but with stiffness varying sinusoidally along the axis. The analysis is an extension of the work previously reported [M. Pierucci J. Acoust. Soc. Am. Suppl. 1 79 S35 (1986)]. The analysis consists of solving the coupled fluid?structure equations with the added difficulty of having nonconstant coefficients. The system reduces to a convoluted equation which has been solved analytically. The results indicate the presence of acoustic pressure components radiating in directions that are related to the difference between the forcing function wavenumber and the wavenumber of the stiffness variation. Acoustic radiation patterns will be presented.

Mauro Pierucci

1987-01-01T23:59:59.000Z