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1

Acoustic resonance determination of the effect of light hydrocarbons on wax appearance points in a Njord well fluid  

SciTech Connect (OSTI)

Wax formation and deposition in pipelines and process equipment pose severe problems for petroleum companies, especially during transportation of crude oil in offshore environments. The light hydrocarbons present in the crude oil can play an important role in the shift of wax appearance points by increasing the solubilities of the heavier components. The following work was undertaken to study the effect of light hydrocarbons on wax appearance points in a Njord well fluid for Norsk Hydro, Norway. An automated high-pressure spherical acoustic resonator (50.8-mm-diameter) assembly designed and fabricated for that purpose has been used to measure resonance frequencies in a Njord well fluid (stabilized oil sample) provided by Norsk Hydro and blended with the appropriate amount of a synthetically prepared gaseous mixture containing six light hydrocarbons (Cl to C6), at pressures from 2 to 107 bar and temperatures in the range 35 to 50{degrees}C. Results on the present method to locate the wax appearance points in the Njord well fluid are presented. A figure showing experimental wax appearance points as a function of pressure is presented. The results are compared with those predicted by the Norsk Hydro model.

Colgate, S.O.; Sivaraman, A.

1996-01-01T23:59:59.000Z

2

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

3

Acoustic resonance determination of the effect of light hydrocarbons on wax appearance points in a Njord well fluid  

Science Journals Connector (OSTI)

Wax formation and deposition in pipelines and process equipment pose severe problems for ... play an important role in the shift of wax appearance points by increasing the solubilities of ... to study the effect ...

S. O. Colgate; A. Sivaraman

1996-01-01T23:59:59.000Z

4

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

5

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

6

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

7

Determination of an equivalent pore size from acoustic flow measurements  

Science Journals Connector (OSTI)

The hydraulic radius r h is defined as the ratio of a channel’s cross?sectional area to its perimeter. This parameter is important for specification of the performance of a porous medium that can be used as a regenerator in a Stirling engine or refrigerator. It is easy to calculate r h for pores of regular geometry but difficult in more complex media. Two techniques which use oscillating flow to determine this parameter will be presented and compared. One technique extracts r h by finding the low velocity limit of the standard expression for viscous pressure drop in the Poiseuille flow regime. The other involves a plot of the nondimensional viscousflow resistance ?p vis/?x??u versus the reciprocal of the viscous penetration depth 1/?? in the laminar flow regime. When r h ?? the flow resistance is frequency dependent and the dynamics is characterized by both r h and ??. It is possible to identify an effective hydraulic radius by equating it to the value of ?? where that transition occurs. [Work supported by ONR.

2005-01-01T23:59:59.000Z

8

Determination of efficiency of anechoic or decoupling hull coatings using water tank acoustic measurements  

E-Print Network [OSTI]

Determination of efficiency of anechoic or decoupling hull coatings using water tank acoustic and radiated noise, respectively. Measurement of test panels in a water tank gives only the reflection in a water tank has already been presented in a previous paper [2]. The purpose of the present paper

Paris-Sud XI, Université de

9

Hydrocarbon saturation determination using acoustic velocities obtained through casing  

DOE Patents [OSTI]

Compressional and shear velocities of earth formations are measured through casing. The determined compressional and shear velocities are used in a two component mixing model to provides improved quantitative values for the solid, the dry frame, and the pore compressibility. These are used in determination of hydrocarbon saturation.

Moos, Daniel (Houston, TX)

2010-03-09T23:59:59.000Z

10

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......

11

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

12

Acoustical effect of progressive undercutting of percussive aluminum bars  

Science Journals Connector (OSTI)

Standard vibraphone bars consist of aluminum beams which are traditionally tuned with an arched undercut for the purpose of aligning the musical overtones harmonically. The acoustical effect of various progressions of undercuts on aluminum bars was studied using both an aluminum bar and a finite element computer model. The spectral signature of the aluminum bar was examined with a spectrum analyzer and the corresponding eigenmodes were imaged with an electronic speckle pattern interferometer. These methods were used to analyze the changes in natural frequencies of the bar as matter was removed from various locations. Additionally the aural character of each cut was captured with an audio recording and the fundamental tone was normalized over all recordings to make possible a subjective comparison of the timbral differences of differently cut bars.

Eric M. Laukkanen; Randy Worland

2011-01-01T23:59:59.000Z

13

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

14

Approximate Effects of Off-Center Acoustic Sondes and Elliptic Boreholes Upon Full Waveform Logs  

E-Print Network [OSTI]

Full waveform acoustic well logging has become instrumental to hydrocarbon exploration because of its ability to determine in situ velocity information for P and S waves as well as the attenuation (or absorption) of seismic ...

Willis, M. E.

1983-01-01T23:59:59.000Z

15

Optics, Acoustics and Stress in Situ (OASIS): Effects of Aggregation, Vertical Structure, and Relation to Physical Forcing.  

E-Print Network [OSTI]

Optics, Acoustics and Stress in Situ (OASIS): Effects of Aggregation, Vertical Structure. Arlington, VA 22203-1995 TITLE: Optics, Acoustics and Stress in Situ (OASIS): Effects of Aggregation of Research and Sponsored Programs #12;Abstract Nearbed optical and acoustical properties in coastal waters

Boss, Emmanuel S.

16

MONITORING POWER PLANT EFFICIENCY USING THE MICROWAVE-EXCITED THERMAL-ACOUSTIC EFFECT TO MEASURE UNBURNED CARBON  

SciTech Connect (OSTI)

The objective of this project is to explore microwave-excited thermal-acoustic (META) phenomena for quantitative analysis of granular and powdered materials, with the culmination of the research to be an on-line carbon-in-ash monitor for coal-fired power plants. This technique of analyzing unburned carbon in fly ash could be a less tedious and time consuming method as compared to the traditional LOI manual procedure. Phase 1 of the research focused on off-line single-frequency thermal-acoustic measurements where an off-line fly ash monitor was constructed that could operate as analytical tool to explore instrument and methodology parameters for quantifying the microwave-excited thermal-acoustic effect of carbon in fly ash, and it was determined that the off-line thermal-acoustic technique could predict the carbon content of a random collection of fly ashes with a linear correlation constant of R{sup 2} = 0.778. Much higher correlations are expected for fly ashes generated from a single boiler. Phase 2 of the research developing a methodology to generate microwave spectra of various powders, including fly ash, coal, and inorganic minerals, and to determine if these microwave spectra could be used for chemical analyses. Although different minerals produced different responses, higher resolution microwave spectra would be required to be able to distinguish among minerals. Phase 3 of the research focused on the development of an on-line fly ash monitor that could be adapted to measure either a thermal-acoustic or thermal-elastic response to due microwave excitation of fly ash. The thermal-acoustic response was successfully employed for this purpose but the thermal-elastic response was too weak to yield a useful on-line device.

Robert C. Brown; Robert J. Weber; Jeffrey J. Swetelitsch

2005-01-01T23:59:59.000Z

17

Nonthermal effects on the ion-acoustic solitons in Lorentzian electron-ion plasmas  

SciTech Connect (OSTI)

The nonthermal effects on the propagation of the ion-acoustic soliton are investigated in generalized Lorentzian electron-ion plasmas. The soliton solution of the Korteweg-de Vries equation is obtained as a function of the spectral index and modified stretched coordinate in the generalized Lorentzian plasma. It is found that the nonthermal effect on the dispersive term is found to be stronger than that on the nonlinear term. It is shown that the nonthermal effect of the Lorentzian plasma strongly suppresses the stretched coordinate of the ion-acoustic soliton. It is also shown that the nonthermal effect increases the position of the ion-acoustic soliton. In addition, the nonthermal effects on the position of the ion-acoustic soliton are found to be more important in the forward direction. It is found that the nonthermal effect strongly suppresses the amplitude of the ion-acoustic soliton in Lorentzian electron-ion plasmas. It is also found that the nonthermal effect on the amplitude of the ion-acoustic soliton is more significant in the backward direction.

Jung, Young-Dae [Department of Applied Physics, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Hong, Woo-Pyo [Department of Electronics Engineering, Catholic University of Daegu, Hayang 712-702 (Korea, Republic of)

2011-02-15T23:59:59.000Z

18

Submilisecond acoustic pulses: effective pitch and Weber-Fechner law in discrimination of duration times  

E-Print Network [OSTI]

The enclosed tests demonstrate that an effective pitch can be attributed to acoustic signals shorter then tenths of milliseconds. A power-law dependence of this pitch on the signal's duration time is found for subjects tested with Gaussian pulses. The discrimination threshold for the pulse duration time reported on the basis of the effective pitch increases proportionally to the duration time itself, i.e. it follows the Weber-Fechner law. A model based on the "Helmholtz's harp" idea, i.e. a series of damped resonators tuned in the audible range of frequencies, reveals the mechanism of producing a maximum in the filtered spectrum of the pulse. This corroborates the power law in the dependence of the position of the maximum on the duration time of the pulse. The model indicates a possibility of designing a manmade device dedicated to determination of the durations so short that they are inaccessible by direct measurements.

Majka, Marcin; G?barowski, Robert; Zieli?ski, Piotr

2014-01-01T23:59:59.000Z

19

Effect of mean fluid flow on an acoustic standing wave in an open cavity  

Science Journals Connector (OSTI)

Acoustic radiation pressure can be used to concentrate or remove small particles from an airborne aerosol. In this application an ultrasonic transducer mounted flush to one wall of a channel is used to excite an integer half?wavelength standing wave of high amplitude that propagates perpendicular to the aerosol flow direction. An expression for the Fourier transform of the acoustic pressure in a semi?infinite channel including the effect of mean fluid flow and finite transducer aperture has been obtained. A parabolic (laminar) mean flow was assumed. The acoustic pressure was found to be governed by the Mach number of the flow defined by the projection of the propagation direction relative to the mean flow velocity vector; and the aperture function of the transducer. Near a frequency of 50 kHz numerical inversions of the acoustic pressure transform showed that the presence of mean flow in the velocity range 0?2 m/s caused changes in acoustic pressure on the order of 1%–4%. Corresponding experimental measurements showed changes in acoustic pressure up to 10%. The highest changes in measured acoustic pressure were found to occur up? and down stream relative to the transducer and these patterns were in agreement with predictions of the analytical model.

2002-01-01T23:59:59.000Z

20

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...

Note: This page contains sample records for the topic "determination acoustic effects" 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

Simple model of photo acoustic system for greenhouse effect  

E-Print Network [OSTI]

The simple theoretical basis for photo acoustic (PA) system for studying infrared absorption properties of greenhouse gases is constructed. The amplitude of sound observed in PA depends on the modulation frequency of light pulse. Its dependence can be explained by our simple model. According to this model, sound signal has higher harmonics. The theory and experiment are compared in third and fifth harmonics by spectrum analysis. The theory has the analogy with electric circuits. This analogy helps students for understanding the PA system.

Fukuhara, Akiko; Ogawa, Naohisa

2010-01-01T23:59:59.000Z

22

Acoustic emission (AE) measurements to determine the dynamic flying characteristics of optical sliders  

Science Journals Connector (OSTI)

Flying heads carrying a magnetic coil and a ... approach to dynamically evaluate the flight attitude of flying heads in data storage is acoustic emission (AE) testing of the head/disk interaction using special gl...

Norman Muenter; Stephan Knappmann; Caspar Morsbach…

2007-01-01T23:59:59.000Z

23

Measuring the effects of acoustical environments on nurses in health?care facilities: A pilot study.  

Science Journals Connector (OSTI)

This paper summarizes the methods and results of a pilot ecological study conducted in four health?care facilities (acute?care community?care and long?term?care). The objective was to consolidate and test tools for exposure assessment and the investigation of study outcomes in particular stress. Area and personal monitoring was performed. Nurse noise exposures were monitored. Full?shift monitoring of sound levels was performed and conventional acoustical parameters derived; new acoustical descriptors including occurrence rate and peakiness were also determined. Two questionnaire scales were developed: a study questionnaire to assess perception of the acoustical environment and of work? and noise?related stresses and a daily diary to capture variations in the perceived stress and document aggressive events. The study questionnaire was found to measure disturbance impaired communication and mental fatigue. Biological markers of noise?related stress (salivary cortisol and heart?rate variability) were collected. Exposure measures were correlated with outcomes; while the results were often not statistically significant due to small sample sizes they identified interesting relationships and validated the measurement tools for future use. Long?term?care was identified as the most acoustically?critical environment both from a physical?acoustical perspective and from the perspective of workers.

Hind Sbihi; Murray Hodgson; George Astrakianakis; Pamela Ratner

2011-01-01T23:59:59.000Z

24

Dislocation contribution to acoustic nonlinearity: The effect of orientation-dependent line energy  

E-Print Network [OSTI]

-static loading assumption using DD simulations. The existing model using a constant line energy assumption failsDislocation contribution to acoustic nonlinearity: The effect of orientation-dependent line energy of the dislocation is shown by the DD simulations. A new model using an orientation-dependent line energy is derived

Cai, Wei

25

Sentential, lexical, and acoustic effects on the perception of word boundaries  

Science Journals Connector (OSTI)

This study investigates the effects of sentential context lexical knowledge and acoustic cues on the segmentation of connected speech. Listeners heard near-homophonous phrases (e.g. ? pl ? mpa ? ? for “plum pie” versus “plump eye”) in isolation in a sentential context or in a lexically biasing context. The sentential context and the acoustic cues were piloted to provide strong versus mild support for one segmentation alternative (plum pie) or the other (plump eye). The lexically biasing context favored one segmentation or the other (e.g. ? sk ? mpa ? ? for “scum pie” versus *“scump eye ” and ? l ? mpa ? ? for “lump eye” versus *“lum pie ” with the asterisk denoting a lexically unacceptable parse). A forced-choice task in which listeners indicated which of two words they thought they heard (e.g. “pie” or “eye”) revealed compensatory mechanisms between the sources of information. The effect of both sentential and lexical contexts on segmentation responses was larger when the acoustic cues were mild than when they were strong. Moreover lexical effects were accompanied with a reduction in sensitivity to the acoustic cues. Sentential context only affected the listeners’ response criterion. The results highlight the graded interactive and flexible nature of multicue segmentation as well as functional differences between sentential and lexical contributions to this process.

Sven L. Mattys; James F. Melhorn

2007-01-01T23:59:59.000Z

26

Locating interfaces in vertically-layered materials and determining concentrations in mixed materials utilizing acoustic-impedance measurements. [Patent application  

DOE Patents [OSTI]

Measurement of the relative and actual value of acoustic characteristic impedances of an unknown substance, location of the interfaces of vertically-layered materials, and the determination of the concentration of a first material mixed in a second material are presented. A highly damped ultrasonic pulse is transmitted into one side of a reference plate, such as a tank wall, where the other side of the reference plate is in physical contact with the medium to be measured. The amplitude of a return signal, which is the reflection of the transmitted pulse from the interface between the other side of the reference plate and the medium, is measured. The amplitude value indicates the acoustic characteristic impedance of the substance relative to that of the reference plate or relative to that of other tested materials. Discontinuities in amplitude with repeated measurements for various heights indicate the location of interfaces in vertically-layered materials. Standardization techniques permit the relative acoustic characteristic impedance of a substance to be converted to an actual value. Calibration techniques for mixtures permit the amplitude to be converted to the concentration of a first material mixed in a second material.

Not Available

1981-06-10T23:59:59.000Z

27

Locating interfaces in vertically-layered materials and determining concentrations in mixed materials utilizing acoustic impedance measurements  

DOE Patents [OSTI]

Measurement of the relative and actual value of acoustic characteristic impedances of an unknown substance, location of the interfaces of vertically-layered materials, and the determination of the concentration of a first material mixed in a second material are disclosed. A highly damped ultrasonic pulse is transmitted into one side of a reference plate, such as a tank wall, where the other side of the reference plate is in physical contact with the medium to be measured. The amplitude of a return signal, which is the reflection of the transmitted pulse from the interface between the other side of the reference plate and the medium, is measured. The amplitude value indicates the acoustic characteristic impedance of the substance relative to that of the reference plate or relative to that of other tested materials. Discontinuities in amplitude with repeated measurements for various heights indicate the location of interfaces in vertically-layered materials. Standardization techniques permit the relative acoustic characteristic impedance of a substance to be converted to an actual value. Calibration techniques for mixtures permit the amplitude to be converted to the concentration of a first material mixed in a second material. 6 figs.

Langlois, G.N.

1983-09-13T23:59:59.000Z

28

Locating interfaces in vertically-layered materials and determining concentrations in mixed materials utilizing acoustic impedance measurements  

DOE Patents [OSTI]

Measurement of the relative and actual value of acoustic characteristic impedances of an unknown substance, location of the interfaces of vertically-layered materials, and the determination of the concentration of a first material mixed in a second material. A highly damped ultrasonic pulse is transmitted into one side of a reference plate, such as a tank wall, where the other side of the reference plate is in physical contact with the medium to be measured. The amplitude of a return signal, which is the reflection of the transmitted pulse from the interface between the other side of the reference plate and the medium, is measured. The amplitude value indicates the acoustic characteristic impedance of the substance relative to that of the reference plate or relative to that of other tested materials. Discontinuities in amplitude with repeated measurements for various heights indicate the location of interfaces in vertically-layered materials. Standardization techniques permit the relative acoustic characteristic impedance of a substance to be converted to an actual value. Calibration techniques for mixtures permit the amplitude to be converted to the concentration of a first material mixed in a second material.

Langlois, Gary N. (Richland, WA)

1983-09-13T23:59:59.000Z

29

Ocean acoustic effects of explosions on land: Evaluation of Cook Inlet beluga whale habitability  

Science Journals Connector (OSTI)

The Eagle River Flats is an impact region for artillery at Fort Richardson Alaska. Adjacent to the Flats is the Knik Arm of Cook Inlet which is the habitat for a distinct population of beluga whales (Delphinapterus leucas). In order to assess the effects of 155 mm artillery explosions on the habitat of these whales a series of 6.8 kg C4 plastique charges were detonated on land 500 meters from the waters edge. In addition to land seismic and acoustic arrays hydrophones were deployed in the Knik Arm at high and low tide. This paper discusses the ocean acoustic measurements. The received signal 30 meters from the shore in water depths of 8 meters was more intense at high tide with broadband peak levels of approximately 180 dB re 1 microPa. The dominant frequency was about 20 Hz and most of the received acoustic energy was below 500 Hz. The geology and oceanography of the area were used to model the acoustic time series. Modeled and measured time series are compared to validate the geophysical model and provide estimates of peak pressure and energy flux density over the near shore habitat. [Work supported by U.S. Army Corps of Engineers CRREL.

Sara K. Tremblay; Thomas S. Anderson; Erin C. Pettit; Peter M. Scheifele; Gopu R. Potty; James H. Miller

2007-01-01T23:59:59.000Z

30

The effect of boundaries on the ion acoustic beam-plasma instability in experiment and simulation  

SciTech Connect (OSTI)

The ion acoustic beam-plasma instability is known to excite strong solitary waves near the Earth's bow shock. Using a double plasma experiment, tightly coupled with a 1-dimensional particle-in-cell simulation, the results presented here show that this instability is critically sensitive to the experimental conditions. Boundary effects, which do not have any counterpart in space or in most simulations, unavoidably excite parasitic instabilities. Potential fluctuations from these instabilities lead to an increase of the beam temperature which reduces the growth rate such that non-linear effects leading to solitary waves are less likely to be observed. Furthermore, the increased temperature modifies the range of beam velocities for which an ion acoustic beam plasma instability is observed.

Rapson, Christopher, E-mail: chris.rapson@ipp.mpg.de [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, D-85748 Garching (Germany)] [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, D-85748 Garching (Germany); Grulke, Olaf [Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald (Germany)] [Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald (Germany); Matyash, Konstantin [Institut für Physik, Ernst-Moritz-Arndt Universität, Domstr. 10a, 17489 Greifswald (Germany)] [Institut für Physik, Ernst-Moritz-Arndt Universität, Domstr. 10a, 17489 Greifswald (Germany); Klinger, Thomas [Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald (Germany) [Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald (Germany); Institut für Physik, Ernst-Moritz-Arndt Universität, Domstr. 10a, 17489 Greifswald (Germany)

2014-05-15T23:59:59.000Z

31

Prediction of a non-uniform freestream velocity distribution for counterrotating propeller configurations and the effect on performance/acoustic  

E-Print Network [OSTI]

aerodynamic loads which are combined with the propeller geometry to predict the radiated acoustics. The effect of the non-uniform freestream velocity distribution on counterrotating propeller design and analysis is shown as well as comparisons with flight...

Allen, Christopher Shane

2012-06-07T23:59:59.000Z

32

High-frequency response and acoustic phonon contribution of the linear electro-optic effect in DAST  

Science Journals Connector (OSTI)

We present a simple method to measure the contribution from acoustic phonons to the linear electro-optic effect. A step voltage with a short rise time (600 ps) is applied to the...

Spreiter, R; Bosshard, Ch; Pan, F; Günter, P

1997-01-01T23:59:59.000Z

33

Echolocation-based foraging by harbor porpoises and sperm whales, including effects of noise and acoustic propagation  

E-Print Network [OSTI]

In this thesis, I provide quantitative descriptions of toothed whale echolocation and foraging behavior, including assessment of the effects of noise on foraging behavior and the potential influence of ocean acoustic ...

DeRuiter, Stacy L

2008-01-01T23:59:59.000Z

34

The Acclimatization Effects of Earplugs on Acoustic and Perceptual Measures of University Singers' Vocal Performances in Choral and Solo Settings  

E-Print Network [OSTI]

ABSTRACT The purpose of this study was to assess with female university singers (N = 34) the potential acclimatization effects of wearing one brand of earplugs marketed to musicians on selected acoustic and perceptual ...

Cook Cunningham, Sheri Lynn

2013-08-31T23:59:59.000Z

35

Effects on Aquatic Organisms (Acoustics and Toxicity) | Department...  

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

(all Conceptual Model work) Effects on the Physical Environment (Hydrodynamics, Sediment Transport, and Water Quality) FY 09 Lab Call: Research & Assessment for MHK...

36

Determination of the pressure at the gas-liquid interface using acoustic speed measurements  

E-Print Network [OSTI]

underestimates this derivative. We can further see that the dPr/d 7r 120 100 Measured values 80 60 40 20 500 1000 1500 2000 2500 8000 3500 Pressul e, Psi;z ? Meas. ~- Phillips ~ 8 eon ~ ll-eon. Fig. 4 ? dPr/dTr in methane vs. pressure 32 value...'c Speed, ft/sec 22 00 2000 Tr = 3. 0 I 800 1600 Tr = 2. 0 1400 Tr = 1. 1 'I 200 0 0. 5 1 1 5 2 2. 5 3 3. 5 4 4. 5 5 5. 5 5 Reduced Pressure ? Publ ~ Gale ~ Publ ~ Calc ~ Pub ~ Ca c Fig. 13 ? Acoustic speed vs. reduced pressure 44 Based...

Heggelund, Dag Gustav

2012-06-07T23:59:59.000Z

37

Internal tides in canyons and their effect on acoustics  

Science Journals Connector (OSTI)

Internal gravity waves of tidal frequency are generated as the ocean tides push water upward onto the continental shelf. Such waves also arrive at the continental slope from deep water and are heavily modified by the change in water depth. The wave generation and wave shoaling effects have an additional level of complexity where a canyon is sliced into the continental slope. Recently steps have been taken to simulate internal tides in canyons to understand the physical processes of internal tides in canyons and also to compute the ramifications on sound propagation in and near the canyons. Internal tides generated in canyons can exhibit directionality with the directionality being consistent with an interesting multiple-scattering effect. The directionality imparts a pattern to the sound-speed anomaly field affecting propagation. The directionality also means that short nonlinear internal waves which have specific strong effects on sound can have interesting patterns near the canyons. In addition to the directionality of internal tides radiated from canyons the internal tide energy within the canyons can be patchy and may unevenly affect sound.

2014-01-01T23:59:59.000Z

38

Viscous effects on the linear stability of a pulsanting bubble in acoustic fields  

Science Journals Connector (OSTI)

A linear stability theory of the harmonic motion of cavitation bubbles subject to an acoustic field with respect... $$\\sqrt {2\

Paolo Blondeaux

1985-12-01T23:59:59.000Z

39

Conservation Cost-Effectiveness Determination Methodology  

E-Print Network [OSTI]

Conservation Cost-Effectiveness Determination Methodology CONSERVATION COST-EFFECTIVENESS As with all other resources, the Council uses its portfolio model to determine how much conservation is cost the amount of savings achievable at varying costs. In order to capture the impact of variations in wholesale

40

3rd International symposium on fluid flow measurement effects of acoustic noise on orifice meters  

SciTech Connect (OSTI)

It is known that in-pipe acoustic noise can cause errors in orifice plate metering. The international metering community voted this topic as the highest priority for further research during a {open_quotes}working{close_quotes} held at N.T.I.S. in 1983. Most published work to date has been concerned with periodic, low frequency noise or pulsations, as encountered on reciprocating compressor installations where errors or their side effects may be readily noticed. Many orifice metering locations are, however, subject to high frequency noise emanating from control valves and centrifugal compressors. High frequency in-pipe noise is seldom suspected as a source of metering error and consequently it is a neglected topic. Square root error, which stems form the non-linear flow-differential pressure relationship of an orifice plate, has been well researched for low frequencies but the work has not been extended to high frequencies. To investigate this topic, high pressure studies at the British Gas Bishop Auckland Test Facility were carried out with a noise source (a pressure drop across a ball valve) and a 600 mm 0.4 {beta} orifice meter. These studies identified the effect of high frequency acoustic noise on orifice plate accuracy.

Norman, R.; Graham, P.; Drew, W.A. [Engineering Research Station, Newcastle Upon Tyne (United Kingdom)

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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

Effects of attenuation, dispersion, and high sound?pressure levels on acoustic wave distortion in horns  

Science Journals Connector (OSTI)

High?power sound sources have received a lot of attention in the past few years due to renewed interest in industrial applications of high?intensity sounds such as the acoustic agglomeration of aerosols or combustion enhancement. Most high?power sound sources require a horn to match the source impedance to the medium where the sound is radiated. Such horns introduce distortion in the initial waveform which can be detrimental to the agglomeration or combustion enhancement process. Boundary?layer attenuation smooths the wave shape while dispersion breaks up the symmetry of the waveform. Horn?induced dispersion is usually the dominant dispersion mechanism resulting in strong peaks in the waveform. Finally due to the very high acoustic levels at the horn throat finite?amplitude effects are responsible for a significant amount of distortion at high frequencies. Simple examples of waveform distortion due to these various mechanisms are shown. The effects of sound?pressure level horn design and frequency on distortion are illustrated for an exponential horn and several initial wave shapes. Experimental results are presented that compare very well with theory.

Frederic G. Pla; Gerhard Reethof

1988-01-01T23:59:59.000Z

42

Apparatus and method for non-contact, acoustic resonance determination of intraocular pressure  

DOE Patents [OSTI]

Apparatus and method for measuring intraocular pressure changes in an eye under investigation by detection of vibrational resonances therein. An ultrasonic transducer operating at its resonant frequency is amplitude modulated and swept over a range of audio frequencies in which human eyes will resonate. The output therefrom is focused onto the eye under investigation, and the resonant vibrations of the eye observed using a fiber-optic reflection vibration sensor. Since the resonant frequency of the eye is dependent on the pressure therein, changes in intraocular pressure may readily be determined after a baseline pressure is established.

Sinha, Dipen N. (Los Alamos, NM); Wray, William O. (Los Alamos, NM)

1994-01-01T23:59:59.000Z

43

Apparatus and method for non-contact, acoustic resonance determination of intraocular pressure  

DOE Patents [OSTI]

The apparatus and method for measuring intraocular pressure changes in an eye under investigation by detection of vibrational resonances therein. An ultrasonic transducer operating at its resonant frequency is amplitude modulated and swept over a range of audio frequencies in which human eyes will resonate. The output therefrom is focused onto the eye under investigation, and the resonant vibrations of the eye observed using a fiber-optic reflection vibration sensor. Since the resonant frequency of the eye is dependent on the pressure therein, changes in intraocular pressure may readily be determined after a baseline pressure is established. 3 figures.

Sinha, D.N.; Wray, W.O.

1994-12-27T23:59:59.000Z

44

Bubbles at the top and bottom of the water column: the acoustical effects, and the use of acoustics to measure them  

Science Journals Connector (OSTI)

Bubbles of atmospheric gas can be entrained by breaking waves at the top of the water column: this bubble population is dynamic and will evolve through the effects of buoyancy gas exsolution and dissolution and the fragmentation and coalescence of bubbles. These processes are important to ambient noise sonar operation and the overall gas budget of the planet. At the base of the water column methanebubbles can occur in marine sediments a phenomenon important to the global methane budget to the petrochemical industry and to the stability of the sediment (e.g. for civil engineering purposes). This paper examines the acoustical effects of both of these populations and the ways in which acoustics can be used to measure them. Data will be presented from field trials including measurements of gassy marine sediments in UK waters and of wave?generated bubble clouds measured by an 11 m spar buoy deployed from 16th June to 18th July 2007 at a distance of 400 miles off the west coast of Portugal.

Timothy G. Leighton; David Coles; Michael A. Ainslie; Paul R. White

2008-01-01T23:59:59.000Z

45

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

46

Effect of surface tension on the acoustic radiation pressure-induced motion of the water-air interface  

E-Print Network [OSTI]

Effect of surface tension on the acoustic radiation pressure-induced motion of the water to be a function of the surface tension. The time of mound formation measurementsin cleanwaterat low.Our objectiveisto investigatetheeffectsof surface tension on mound formation. We usea boundaryintegralmethodto

Khuri-Yakub, Butrus T. "Pierre"

47

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

48

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

49

Landau damping effects on dust-acoustic solitary waves in a dusty negative-ion plasma  

SciTech Connect (OSTI)

The nonlinear theory of dust-acoustic waves (DAWs) with Landau damping is studied in an unmagnetized dusty negative-ion plasma in the extreme conditions when the free electrons are absent. The cold massive charged dusts are described by fluid equations, whereas the two-species of ions (positive and negative) are described by the kinetic Vlasov equations. A Korteweg-de Vries (KdV) equation with Landau damping, governing the dynamics of weakly nonlinear and weakly dispersive DAWs, is derived following Ott and Sudan [Phys. Fluids 12, 2388 (1969)]. It is shown that for some typical laboratory and space plasmas, the Landau damping (and the nonlinear) effects are more pronounced than the finite Debye length (dispersive) effects for which the KdV soliton theory is not applicable to DAWs in dusty pair-ion plasmas. The properties of the linear phase velocity, solitary wave amplitudes (in presence and absence of the Landau damping) as well as the Landau damping rate are studied with the effects of the positive ion to dust density ratio (?{sub pd}) as well as the ratios of positive to negative ion temperatures (?) and masses (m)

Barman, Arnab; Misra, A. P., E-mail: apmisra@visva-bharati.ac.in, E-mail: apmisra@gmail.com [Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan 731 235, West Bengal (India)

2014-07-15T23:59:59.000Z

50

Assessment of the acoustic effects on marine animals by an offshore wind farm.  

Science Journals Connector (OSTI)

As part of the planning for an offshore wind farm in Rhode Island coastal waters an assessment of the potential acoustic effects on the ecosystem is being conducted. The developer has proposed to initially deploy eight 3.6?MW wind turbines within 3 nm of Block Island. Two passive aquatic listener (PAL) systems were deployed south of Block Island from October 6 to November 11 2008. Using data from the PALs ambient noise histograms were computed for this pre?construction phase. The largest sources of noise in the area at low frequencies were found to be from shipping wind rain and biological sources. In addition transmission loss measurements were also made in the region to calibrate a geoacoustic model. Measurements of airborne noise from a 1.5?MW land?based wind turbine already in operation in Rhode Island were made in 1/3?octave bands and near the proposed windfarm site. A preliminary assessment of the effects of the offshore wind farm on marine animals at these sites will be presented. A plan for monitoring the noise field and potential biological effects during construction and operation of the windfarm is presented. [Funding provided by the RI Office of Energy Resources.

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

2010-01-01T23:59:59.000Z

51

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

52

Assessment of the acoustic effects of offshore wind turbines on the marine ecosystem.  

Science Journals Connector (OSTI)

The University of Rhode Island recently completed an assessment of the potential acoustic and other effects of the wind farms on the ecosystem. A developer has proposed to initially construct eight 3.6?MW wind turbines on lattice jacket structures 5 km south of Block Island and approximately 100 turbines in a second stage 20 km east of Block Island. Construction on the first stage is tentatively planned for summer of 2011 and pile driving will be the main source of noise. The main source of operational noise will likely be vibration from the turbine conducted through the lattice jacket structure into the water. Two passive aquatic listener (PAL) systems were deployed 5 km of Block Island from October 6 to November 11 2008. Two more PAL systems were deployed on meteorological buoys one near the first farm and one near the larger farm for 12 months in 2009/2010. Using data from the PALs ambient noise budgets and histograms were computed for this pre?construction phase. The largest sources of noise were found to be shipping wind rain and biological sources. An assessment of the effects of the offshore wind farms will be presented for both the construction and operational phases.?

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

2010-01-01T23:59:59.000Z

53

Microwave-induced thermoacoustic tomography: applications and corrections for the effects of acoustic heterogeneities  

E-Print Network [OSTI]

This research is primarily focused on developing potential applications for microwaveinduced thermoacoustic tomography and correcting for image degradations caused by acoustic heterogeneities. Microwave-induced thermoacoustic tomography was first...

Jin, Xing

2009-05-15T23:59:59.000Z

54

Estimation of Dry-Rock Elastic Moduli Based on the Simulation of Mud-Filtrate Invasion Effects on Borehole Acoustic Logs  

E-Print Network [OSTI]

Effects on Borehole Acoustic Logs Tobiloluwa Odumosu, SPE, Carlos Torres-Verdín, SPE, Jesús M Salazar, SPE. Jun Ma, Ben Voss, and Gong Li Wang, SPE, The University of Texas at Austin Copyright 2007, Society

Torres-Verdín, Carlos

55

Vibration and acoustic radiation from inhomogeneous structures: Effect of motion of forcing function  

Science Journals Connector (OSTI)

Homogeneous structures are known to radiate only for supersonic structural wavenumbers. The presence of inhomogeneities such as boundaries discrete stiffeners and variable stiffness has been shown to introduce additional modes that will radiate if the structural wavenumbers are supersonic. The radiation pattern for an infinite plate with evenly spaced stiffness gives rise to a stop?passband spectrum. The plate with a continuously varying stiffness also gives rise to similar conditions. All of the previous analyses have always considered stationary forcing functions. In this paper the analyses for the fixed forcing function will be reviewed and then they will be generalized to the case of the forcing function moving along the plate at speeds up to and greater than the wave speeds in the solid. The results presented will show that for certain values of the frequency rib spacings and forcing function velocity traveling wave modes may change direction decaying modes may become traveling modes and modes may change from subsonic to supersonic and vice versa depending upon the relative motion of the forcing function. The effect of the motion may thus enhance or reduce the acoustic radiation.

Mauro Pierucci

1988-01-01T23:59:59.000Z

56

Internal?wave effects on 1000?km oceanic acoustic pulse propagation: Simulation and comparison with experiment  

Science Journals Connector (OSTI)

A recent 1000?km acoustic pulse transmission experiment in the Pacific revealed unexpected fluctuations on received wavefronts including a dominant rapid variation called the broadband fluctuation with time scales less than 10 minutes and spatial scales of less than 60 m; a distinct breakdown of the geometrical optics wavefront pattern and broadening of the wavefront near the transmission finalé; and a coherent wavefront motion with a timescale near the semi?diurnal tidal period. Parabolic?equation numerical simulations have been carried out which utilize environmental data and which take into account internal?wave?induced sound?speed perturbations obeying the Garrett–Munk (GM) spectral model. It is shown that the effects of internal waves can account for the broadband fluctuations the breakdown of the geometrical opticspattern and the wavefront broadening. The sensitivity of these fluctuations to internal?wave energy and modal content is examined. The spectral energy in the GM model at tidal periods proves insufficient to explain the tidal period coherent fluctuations strongly suggesting the influence of an internal tide during the experiment. The simulations allow the estimation of the average travel?time bias caused by internal waves. The simulation results for travel?time wander and bias are compared with analytic calculations based on the path?integral technique.

John A. Colosi; Stanley M. Flatté; Charles Bracher

1994-01-01T23:59:59.000Z

57

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

58

Effects of tone on the three-way laryngeal distinction in Korean: An acoustic and aerodynamic comparison of the Seoul and South Kyungsang dialects  

E-Print Network [OSTI]

KU ScholarWorks | http://kuscholarworks.ku.edu Effects of tone on the three-way laryngeal distinction in Korean: An acoustic and aerodynamic comparison of the Seoul and South Kyungsang dialects by Hyunjung Lee and Allard Jongman KU Scholar... below. Lee, H., and Jongman, A. (2012). Effects of tone on the three-way laryngeal distinction in Korean: An acoustic and aerodynamic comparison of the Seoul and South Kyungsang dialects. Journal of the International Phonetic Association 42, 145...

Lee, Hyunjung; Jongman, Allard

2012-08-01T23:59:59.000Z

59

Effects of obliqueness and strong electrostatic interaction on linear and nonlinear propagation of dust-acoustic waves in a magnetized strongly coupled dusty plasma  

SciTech Connect (OSTI)

Linear and nonlinear propagation of dust-acoustic waves in a magnetized strongly coupled dusty plasma is theoretically investigated. The normal mode analysis (reductive perturbation method) is employed to investigate the role of ambient/external magnetic field, obliqueness, and effective electrostatic dust-temperature in modifying the properties of linear (nonlinear) dust-acoustic waves propagating in such a strongly coupled dusty plasma. The effective electrostatic dust-temperature, which arises from strong electrostatic interactions among highly charged dust, is considered as a dynamical variable. The linear dispersion relation (describing the linear propagation characteristics) for the obliquely propagating dust-acoustic waves is derived and analyzed. On the other hand, the Korteweg-de Vries equation describing the nonlinear propagation of the dust-acoustic waves (particularly, propagation of dust-acoustic solitary waves) is derived and solved. It is shown that the combined effects of obliqueness, magnitude of the ambient/external magnetic field, and effective electrostatic dust-temperature significantly modify the basic properties of linear and nonlinear dust-acoustic waves. The results of this work are compared with those observed by some laboratory experiments.

Shahmansouri, M. [Department of Physics, Faculty of Science, Arak University, Arak 38156- 8 8349 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Science, Arak University, Arak 38156- 8 8349 (Iran, Islamic Republic of); Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)] [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)

2014-03-15T23:59:59.000Z

60

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

EFFECT OF COMBUSTOR INLET GEOMETRY ON ACOUSTIC SIGNATURE AND FLOW FIELD BEHAVIOUR OF THE LOW SWIRL INJECTOR  

SciTech Connect (OSTI)

Low Swirl Injector (LSI) technology is a lean premixed combustion method that is being developed for fuel-flexible gas turbines. The objective of this study is to characterize the fuel effects and influences of combustor geometry on the LSI's overall acoustic signatures and flowfields. The experiments consist of 24 flames at atmospheric condition with bulk flows ranging between 10 and 18 m/s. The flames burn CH{sub 4} (at {phi} = 0.6 & 0.7) and a blend of 90% H{sub 2} - 10% CH{sub 4} by volume (at {phi} = 0.35 & 0.4). Two combustor configurations are used, consisting of a cylindrical chamber with and without a divergent quarl at the dump plane. The data consist of pressure spectral distributions at five positions within the system and 2D flowfield information measured by Particle Imaging Velocimetry (PIV). The results show that acoustic oscillations increase with U{sub 0} and {phi}. However, the levels in the 90% H{sub 2} flames are significantly higher than in the CH{sub 4} flames. For both fuels, the use of the quarl reduces the fluctuating pressures in the combustion chamber by up to a factor of 7. The PIV results suggest this to be a consequence of the quarl restricting the formation of large vortices in the outer shear layer. A Generalized Instability Model (GIM) was applied to analyze the acoustic response of baseline flames for each of the two fuels. The measured frequencies and the stability trends for these two cases are predicted and the triggered acoustic mode shapes identified.

Therkelsen, Peter L.; Littlejohn, David; Cheng, Robert K.; Portillo, J. Enrique; Martin, Scott M.

2009-11-30T23:59:59.000Z

62

MHD wave refraction and the acoustic halo effect around solar active regions - a 3D study  

E-Print Network [OSTI]

An enhancement in high-frequency acoustic power is commonly observed in the solar photosphere and chromosphere surrounding magnetic active regions. We perform 3D linear forward wave modelling with a simple wavelet pulse acoustic source to ascertain whether the formation of the acoustic halo is caused by MHD mode conversion through regions of moderate and inclined magnetic fields. This conversion type is most efficient when high frequency waves from below intersect magnetic field lines at a large angle. We find a strong relationship between halo formation and the equipartition surface at which the Alfv\\'en speed $a$ matches the sound speed $c$, lending support to the theory that photospheric and chromospheric halo enhancement is due to the creation and subsequent reflection of magnetically dominated fast waves from essentially acoustic waves as they cross $a=c$. In simulations where we have capped $a$ such that waves are not permitted to refract after reaching the $a=c$ height, halos are non-existent, which su...

Rijs, Carlos; Przybylski, Damien; Cally, Paul S

2015-01-01T23:59:59.000Z

63

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

64

Dust negative ion acoustic shock waves considering dust size distribution effect  

SciTech Connect (OSTI)

A multi-ion dusty plasma containing hot isothermal electrons, ions (light positive ions and heavy negative ions), and extremely and negatively charged dust grains is studied in the present paper. The dust negative ion acoustic shock waves have been investigated by employing the reductive perturbation method. How the dust size distribution affects the height and the thickness of the nonlinear shock wave is studied. It is noted that the different dust size distribution has different shock wave form and different moving speed.

Ma Yirong; Wang Canglong; Zhang Jianrong; Sun Jianan; Duan Wenshan [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou 730070, China and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yang Lei [College of Physics and Electronic Engineering and Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Northwest Normal University, Lanzhou 730070 (China) and Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Department of Physics, Lanzhou University, Lanzhou 730000 (China)

2012-11-15T23:59:59.000Z

65

Examination and development of numerical methods and algorithms designed for the determination of an enclosure’s acoustical characteristics via the Schroeder Function  

Science Journals Connector (OSTI)

A case study was conducted to measure the acoustical properties of a church auditorium. While modeling the project using EASE 2.1 some problems arose when attempting to determine the reverberation time using the Schroder Back Integrated Impulse Function within EASE 2.1. An auxiliary investigation was launched aiming to better understand the Schroeder algorithm in order to produce a potentially improved version in MATLAB. It was then theorized that the use of a single linear regression is not sufficient to understand the nature of the decay due to the non-linearity of the curve particularly during the initial decay. Rather it is hypothesized that the use of numerical methods to find instantaneous rates of change over the entire initial decay along with a Savitsky-Golay Filter could possibly yield much more robust accurate results when attempting to derive the local reverberation time from reflectogram data.

2014-01-01T23:59:59.000Z

66

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

67

Environmental assessment of offshore wind power generation near Rhode Island: Acoustic and electromagnetic effects on marine animals.  

Science Journals Connector (OSTI)

An offshore wind farm is planned for Rhode Island coastal waters. The developer has proposed to deploy wind turbines in two stages: 5 turbines in shallow waters 5 km south of Block Island and 100 turbines in deeper waters 30 km to the east. As part of the planning of the proposed offshore wind powergeneration project under the Rhode Island Special Area Management Plan ambient acoustic and electromagneticmeasurements were made in the area. Two passive acoustic listener (PAL) systems were deployed within 4 km of Block Island from October 6 to November 11 2008. Data from the PALs were used to compute the ocean acousticnoise budget and other statistics by source. Transmission loss measurements were also made to support the noise budget calculation. Measurements of airborne noise from a 1.5?MW land?based wind turbine already in operation in Rhode Island were made. To support the electromagneticeffect study an underwater magnetometer was towed at the two proposed sites and over an operational underwater 23?kV power cable. A preliminary assessment of the effects of the offshore wind farm on marine animals at these sites will be presented. [Funding provided by the RI Office of Energy Resources.

James H. Miller; Gopu R. Potty; Kathleen Vigness Raposa; David Casagrande; Lisa Miller; Steven E. Crocker; Robert Tyce; Jonathan Preston; Brian Roderick; Jeffrey A. Nystuen; Peter M. Scheifele

2009-01-01T23:59:59.000Z

68

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

69

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

70

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

SciTech Connect (OSTI)

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

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

2011-09-30T23:59:59.000Z

71

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

72

EFFECT OF MODEL-DEPENDENT COVARIANCE MATRIX FOR STUDYING BARYON ACOUSTIC OSCILLATIONS  

SciTech Connect (OSTI)

Large-scale structures in the universe are a powerful tool to test cosmological models and constrain cosmological parameters. A particular feature of interest comes from baryon acoustic oscillations (BAOs), which are sound waves traveling in the hot plasma of the early universe that stopped at the recombination time. This feature can be observed as a localized bump in the correlation function at the scale of the sound horizon r{sub s} . As such, it provides a standard ruler and a lot of constraining power in the correlation function analysis of galaxy surveys. Moreover, the detection of BAOs at the expected scale gives strong support to cosmological models. Both of these studies (BAO detection and parameter constraints) rely on a statistical modeling of the measured correlation function {xi}-circumflex. Usually {xi}-circumflex is assumed to be Gaussian, with a mean {xi}{sub {theta}} depending on the cosmological model and a covariance matrix C generally approximated as a constant (i.e., independent of the model). In this article, we study whether a realistic model-dependent C {sub {theta}} changes the results of cosmological parameter constraints compared to the approximation of a constant covariance matrix C. For this purpose, we use a new procedure to generate lognormal realizations of the luminous red galaxy sample of the Sloan Digital Sky Survey Data Release 7 to obtain a model-dependent C {sub {theta}} in a reasonable time. The approximation of C {sub {theta}} as a constant creates small changes in the cosmological parameter constraints on our sample. We quantify this modeling error using a lot of simulations and find that it only has a marginal influence on cosmological parameter constraints for current and next-generation galaxy surveys. It can be approximately taken into account by extending the 1{sigma} intervals by a factor Almost-Equal-To 1.3.

Labatie, A.; Starck, J. L. [Laboratoire AIM (UMR 7158), CEA/DSM-CNRS-Universite Paris Diderot, IRFU, SEDI-SAP, Service d'Astrophysique, Centre de Saclay, F-91191 Gif-Sur-Yvette cedex (France); Lachieze-Rey, M., E-mail: antoine.labatie@cea.fr [Astroparticule et Cosmologie (APC), CNRS-UMR 7164, Universite Paris 7 Denis Diderot, 10, rue Alice Domon et Leonie Duquet, F-75205 Paris Cedex 13 (France)

2012-12-01T23:59:59.000Z

73

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.

74

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......

75

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

76

Acoustic microscopy for characterization of high?temperature superconducting tape  

Science Journals Connector (OSTI)

Although material scientists constantly discover superconducting compounds with higher critical temperatures (T c ’s) manufacturing of the high?temperature superconductors(HTS) remains a problem and long lengths (>1 mile) have yet to be produced. In an effort to produce long length superconductors manufacturing steps for HTS tape production have been critically looked at to find their effects in producing tape with the desired characteristics. In support of determining superconducting tapecharacteristics acoustic microscopy offers the potential for internal microstructural material characterization. This research will ultimately support in?process monitoring of HTSmanufacturing as part of an advanced sensing system to determine the presence of defects and/or the effects of process variables on the HTS tape. This presentation will overview scanning acoustic microscopy and present images of HTS tape at several frequencies ranging from 50 to 500 MHz. The results clearly demonstrate the feasibility of determining the Ag/ceramic interface location and the general integrity of the constituents.

Chiaki Miyasaka; Chris Cobucci; Bernhard Tittmann

1997-01-01T23:59:59.000Z

77

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

78

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

79

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

80

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

82

Effect of a transition layer on acoustic transmission from a fluid to an elastic layer  

Science Journals Connector (OSTI)

In order for a compliant surface to be able to interact with a flow field in a constructive manner it is necessary that energy between the fluid and the compliant layer be exchanged very effectively. In this letter the fluid energy is assumed to be a plane wave traveling in the direction normal to a finite thickness elastic layer. A thin transition layer is placed at the interface between the two media.

Mauro Pierucci

1987-01-01T23:59:59.000Z

83

Determining effects of turbine blades on fluid motion  

DOE Patents [OSTI]

Disclosed is a technique for simulating wind interaction with wind turbines. A turbine blade is divided into radial sections. The effect that each of these radial sections has on the velocities in Eulerian computational cells they overlap is determined. The effect is determined using Lagrangian techniques such that the calculations need not include wind components in the radial direction. A force on each radial section of turbine blade is determined. This force depends on the axial and azimuthal components of the fluid flow in the computational cell and the geometric properties of the turbine blade. The force on the turbine blade is fed back to effect the fluid flow in the computational cell for the next time step.

Linn, Rodman Ray (Los Alamos, NM); Koo, Eunmo (Los Alamos, NM)

2011-05-31T23:59:59.000Z

84

Determining effects of turbine blades on fluid motion  

DOE Patents [OSTI]

Disclosed is a technique for simulating wind interaction with wind turbines. A turbine blade is divided into radial sections. The effect that each of these radial sections has on the velocities in Eulerian computational cells they overlap is determined. The effect is determined using Lagrangian techniques such that the calculations need not include wind components in the radial direction. A force on each radial section of turbine blade is determined. This force depends on the axial and azimuthal components of the fluid flow in the computational cell and the geometric properties of the turbine blade. The force on the turbine blade is fed back to effect the fluid flow in the computational cell for the next time step.

Linn, Rodman Ray (Los Alamos, NM); Koo, Eunmo (Los Alamos, NM)

2012-05-01T23:59:59.000Z

85

Acoustic calibration of the Exterior Effects Room at the NASA Langley Research Center  

Science Journals Connector (OSTI)

The Exterior Effects Room (EER) at the NASA Langley Research Center is a 39-seat auditorium built for psychoacoustic studies of aircraft community noise. The original reproduction system employed monaural playback and hence lacked sound localization capability. In an effort to more closely recreate field test conditions a significant upgrade was undertaken to allow simulation of a three-dimensional audio and visual environment. The 3D audio system consists of 27 mid and high frequency satellite speakers and 4 subwoofers driven by a real-time audio server running an implementation of Vector Base Amplitude Panning. The audio server is part of a larger simulation system which controls the audio and visual presentation of recorded and synthesized aircraft flyovers. The focus of this work is on the calibration of the 3D audio system including gains used in the amplitude panning algorithm speaker equalization and absolute gain control. Because the speakers are installed in an irregularly shaped room the speaker equalization includes time delay and gain compensation due to different mounting distances from the focal point filtering for color compensation due to different installations (half space corner baffled/unbaffled) and cross-over filtering.

Kenneth J. Faller II; Stephen Rizzi; Jacob Klos; William L. Chapin; Fahri Surucu; Aric R. Aumann

2012-01-01T23:59:59.000Z

86

Acoustic calibration of the exterior effects room at the NASA Langley Research Center.  

Science Journals Connector (OSTI)

The exterior effects room (EER) at the NASA Langley Research Center is a 39?seat auditorium built for psychoacoustic studies of aircraft community noise. The original reproduction system employed monaural playback and hence lacked sound localization capability. In an effort to more closely recreate field test conditions a significant upgrade was undertaken to allow simulation of a three?dimensional (3?D) audio and visual environment. The 3?D audio system consists of 27 full?range satellite speakers and four subwoofers driven by a real?time audio server running a derivation of vector base amplitude panning. The audio server is part of a larger simulation system which controls the audio and visual presentation of recorded and synthesized aircraft flyovers. The focus of this work is on the calibration of the 3?D audio system including gains used in the amplitude panning algorithm speaker equalization and absolute gain control. Because the speakers are installed in an irregularly shaped room the speaker equalization includes time delay and gain compensation due to different mounting distances from the focal point filtering for color compensation due to different installations (half space corner and baffled/unbaffled) and crossover filtering.

Kenneth J. Faller II; Stephen A. Rizzi; Jacob Klos; William L. Chapin; Fahri Surucu; Aric R. Aumann

2010-01-01T23:59:59.000Z

87

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.

88

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

89

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

90

Effects of dust size distribution on dust negative ion acoustic solitary waves in a magnetized dusty plasma  

SciTech Connect (OSTI)

Dust negative ion acoustic solitary waves in a magnetized multi-ion dusty plasma containing hot isothermal electron, ions (light positive ions and heavy negative ions) and extremely massive charge fluctuating dust grains are investigated by employing the reductive perturbation method. How the dust size distribution affect the height and the thickness of the nonlinear solitary wave are given. It is noted that the characteristic of the solitary waves are different with the different dust size distribution. The magnitude of the external magnetic field also affects the solitary wave form.

Ma, Yi-Rong; Qi, Xin; Sun, Jian-An; Duan, Wen-Shan [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China)] [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Yang, Lei [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China) [Joint Laboratory of Atomic and Molecular Physics of NWNU and IMP CAS, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China and College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Department of Physics, Lanzhou University, Lanzhou 730000 (China)

2013-08-15T23:59:59.000Z

91

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

92

Effects of liquid pore water on acoustic wave propagation in snow as a Biot-type porous material  

E-Print Network [OSTI]

A method to estimate phase velocity and attenuation of acoustic waves in the presence of liquid water in a snowpack is presented. The method is based on Biot's theory of wave propagation in porous materials. Empirical relations and a priori information is used to characterize snow as a porous material as a function of porosity. Plane wave theory and an equivalent pore fluid are used to solve Biot's differential equations and to asses the impact of the air and water in the pore space. The liquid water in the pore space of a snow pack reduces the velocity of the first compressional wave by roughly 300 m/s for every 0.1 increase in liquid water saturation. Also the attenuation of the compressional waves is increased with increasing liquid water content. Two end member models for compaction are evaluated to asses the importance of an independent density measurement for an estimate of liquid pore water saturation in snow with acoustic waves. The two end members correspond to no compaction at all and to a melting s...

Sidler, Rolf

2015-01-01T23:59:59.000Z

93

ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS  

SciTech Connect (OSTI)

The research during this project has concentrated on developing a correlation between rock deformation mechanisms and their acoustic velocity signature. This has included investigating: (1) the acoustic signature of drained and undrained unconsolidated sands, (2) the acoustic emission signature of deforming high porosity rocks (in comparison to their low porosity high strength counterparts), (3) the effects of deformation on anisotropic elastic and poroelastic moduli, and (4) the acoustic tomographic imaging of damage development in rocks. Each of these four areas involve triaxial experimental testing of weak porous rocks or unconsolidated sand and involves measuring acoustic properties. The research is directed at determining the seismic velocity signature of damaged rocks so that 3-D or 4-D seismic imaging can be utilized to image rock damage. These four areas of study are described in the report: (1) Triaxial compression experiments have been conducted on unconsolidated Oil Creek sand at high confining pressures. (2) Initial experiments on measuring the acoustic emission activity from deforming high porosity Danian chalk were accomplished and these indicate that the AE activity was of a very low amplitude. (3) A series of triaxial compression experiments were conducted to investigate the effects of induced stress on the anisotropy developed in dynamic elastic and poroelastic parameters in rocks. (4) Tomographic acoustic imaging was utilized to image the internal damage in a deforming porous limestone sample. Results indicate that the deformation damage in rocks induced during laboratory experimentation can be imaged tomographically in the laboratory. By extension the results also indicate that 4-D seismic imaging of a reservoir may become a powerful tool for imaging reservoir deformation (including imaging compaction and subsidence) and for imaging zones where drilling operation may encounter hazardous shallow water flows.

Thurman E. Scott, Jr.; Younane Abousleiman

2004-04-01T23:59:59.000Z

94

Survival of Seaward-Migrating PIT and Acoustic-Tagged Juvenile Chinook Salmon in the Snake and Columbia Rivers: An Evaluation of Length-Specific Tagging Effects  

SciTech Connect (OSTI)

Studies examining the survival of juvenile salmon as they emigrate to the ocean provide important information regarding the management of regulated river systems. Acoustic telemetry is a widely used tool for evaluating the behavior and survival of juvenile salmonids in the Columbia River basin. Thus, it is important to understand how the surgical tagging process and the presence of a transmitter affect survival so any biases can be accounted for or eliminated. This study evaluated the effects of fish length and tag type on the survival of yearling and subyearling Chinook salmon during their seaward migrations through the Snake and Columbia rivers during 2006, 2007, and 2008. Fish were collected at Lower Granite Dam on the Snake River (river kilometer 695) and implanted with either only a passive integrated transponder (PIT) tag (PIT fish) or both a PIT tag and an acoustic transmitter (AT fish). Survival was estimated from release at Lower Granite Dam to multiple downstream locations (dams) using the Cormack–Jolly–Seber single release model, and analysis of variance was used to test for differences among length-classes and between tag types. No length-specific tag effect was detected between PIT and AT fish (i.e., length affected the survival of PIT fish in a manner similar to which it affected the survival of AT fish). Survival among the smallest length class (i.e., 80–89 mm) of both PIT and AT subyearling Chinook salmon was markedly low (i.e., 4%). Fish length was positively correlated with the survival of both PIT and AT fish. Significant differences in survival were detected between tag types; the survival of PIT fish was generally greater than that of AT fish. However, confounding variables warrant caution in making strong inferences regarding this factor. Further, results suggest that tag effects may be due to the process of surgically implanting the transmitter rather than the presence of the transmitter.

Brown, Richard S.; Oldenburg, Eric W.; Seaburg, Adam; Cook, Katrina V.; Skalski, John R.; Eppard, M. B.; Deters, Katherine A.

2013-06-12T23:59:59.000Z

95

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,

96

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

97

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

98

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

99

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

100

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

102

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

103

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

104

Energetic-Particle-Induced Geodesic Acoustic Mode Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA  

E-Print Network [OSTI]

Energetic-Particle-Induced Geodesic Acoustic Mode G. Y. Fu* Princeton Plasma Physics Laboratory-induced geodesic acoustic mode (EGAM) is shown to exist. The mode frequency and mode structure are determined comparable to that of geodesic acoustic mode (GAM) [4]. Here it is shown analytically and numerically

105

Device and method for generating a beam of acoustic energy from a borehole, and applications thereof  

DOE Patents [OSTI]

In some aspects of the invention, a method of generating a beam of acoustic energy in a borehole is disclosed. The method includes generating a first acoustic wave at a first frequency; generating a second acoustic wave at a second frequency different than the first frequency, wherein the first acoustic wave and second acoustic wave are generated by at least one transducer carried by a tool located within the borehole; transmitting the first and the second acoustic waves into an acoustically non-linear medium, wherein the composition of the non-linear medium produces a collimated beam by a non-linear mixing of the first and second acoustic waves, wherein the collimated beam has a frequency based upon a difference between the first frequency and the second frequency; and transmitting the collimated beam through a diverging acoustic lens to compensate for a refractive effect caused by the curvature of the borehole.

Vu, Cung Khac; Sinha, Dipen N; Pantea, Cristian; Nihei, Kurt T; Schmitt, Denis P; Skelt, Christopher

2013-10-01T23:59:59.000Z

106

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

107

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

108

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

109

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

110

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

111

The Measurement of Bubble-Size Distributions by Acoustical Backscatter  

Science Journals Connector (OSTI)

A multifrequency acoustical-backscatter technique is described for determining the size distribution of bubbles with radii between 8 and 130 µm. The method makes use of the resonance in the microbubbles and operates at six frequencies ranging ...

Svein Vagle; David M. Farmer

1992-10-01T23:59:59.000Z

112

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

113

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

114

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

115

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

116

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

117

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

118

In-situ physical properties measurements using crosswell acoustic data  

SciTech Connect (OSTI)

Crosswell acoustic surveys enable the in-situ measurements of elastic moduli, Poisson's ratio, porosity, and apparent seismic Q of gas-bearing low-permeability formations represented at the Department of Energy Multi-Well Experiment (MWX) site near Rifle, Colorado. These measurements, except for Q, are compared with laboratory measurements on core taken from the same depths at which the crosswell measurements are made. Seismic Q determined in situ is compared to average values for sandstone. Porosity was determined from crosswell data using the empirical relationship between acoustic velocity, porosity, and effective pressure developed by Domenico. Domenico, S.N., ''Rock Lithology and Porosity Determination from Shear and compressional Wave Velocity,'' Geophysics, Vol. 49, No. 9, Aug. 1984, pp. 1188-1195. In-situ porosities are significantly greater than the core-derived values. Sources of the discrepancy may arise from (i) the underestimation of porosity that can result when Boyle's Law measurements are made on low-permeability core and (ii) the application of Dominico's relationship, which is developed for clean sands, to the mixed sandstone and shale lithologies represented at the MWX site. Values for Young's modulus and Poisson's ratio derived from crosswell measurements are comparable to values obtained from core. Apparent seismic Q measured in situ between wells is lower than Q measured on core and clearly shows the heterogeneity of sandstone deposited in a fluvial environment. 16 refs., 4 figs., 2 tabs.

Johnson, P.A.; Albright, J.N.

1985-01-01T23:59:59.000Z

119

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

120

THE ACOUSTIC CUTOFF FREQUENCY OF THE SUN AND THE SOLAR MAGNETIC ACTIVITY CYCLE  

SciTech Connect (OSTI)

The acoustic cutoff frequency-the highest frequency for acoustic solar eigenmodes-is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value, acoustic disturbances are no longer trapped but are traveling waves. Interference among them gives rise to higher-frequency peaks-the pseudomodes-in the solar acoustic spectrum. The pseudomodes are shifted slightly in frequency with respect to p-modes, making possible the use of pseudomodes to determine the acoustic cutoff frequency. Using data from the GOLF and VIRGO instruments on board the Solar and Heliospheric Observatory spacecraft, we calculate the acoustic cutoff frequency using the coherence function between both the velocity and intensity sets of data. By using data gathered by these instruments during the entire lifetime of the mission (1996 until the present), a variation in the acoustic cutoff frequency with the solar magnetic activity cycle is found.

Jimenez, A.; Palle, P. L. [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Garcia, R. A. [Laboratoire AIM, CEA/DSM-CNRS, Universite Paris 7 Diderot, IRFU/Sap, Centre de Saclay, F-91191 Gif-sur-Yvette (France)

2011-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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

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.

122

Physical and biological factors determining the effective proton range  

SciTech Connect (OSTI)

Purpose: Proton radiotherapy is rapidly becoming a standard treatment option for cancer. However, even though experimental data show an increase of the relative biological effectiveness (RBE) with depth, particularly at the distal end of the treatment field, a generic RBE of 1.1 is currently used in proton radiotherapy. This discrepancy might affect the effective penetration depth of the proton beam and thus the dose to the surrounding tissue and organs at risk. The purpose of this study was thus to analyze the impact of a tissue and dose dependent RBE of protons on the effective range of the proton beam in comparison to the range based on a generic RBE of 1.1.Methods: Factors influencing the biologically effective proton range were systematically analyzed by means of treatment planning studies using the Local Effect Model (LEM IV) and the treatment planning software TRiP98. Special emphasis was put on the comparison of passive and active range modulation techniques.Results: Beam energy, tissue type, and dose level significantly affected the biological extension of the treatment field at the distal edge. Up to 4 mm increased penetration depth as compared to the depth based on a constant RBE of 1.1. The extension of the biologically effective range strongly depends on the initial proton energy used for the most distal layer of the field and correlates with the width of the distal penumbra. Thus, the range extension, in general, was more pronounced for passive as compared to active range modulation systems, whereas the maximum RBE was higher for active systems.Conclusions: The analysis showed that the physical characteristics of the proton beam in terms of the width of the distal penumbra have a great impact on the RBE gradient and thus also the biologically effective penetration depth of the beam.

Grün, Rebecca [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany) [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany); Institute of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen 35390 (Germany); Medical Faculty of Philipps-University Marburg, Marburg 35032 (Germany); Friedrich, Thomas; Krämer, Michael; Scholz, Michael [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany)] [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany); Zink, Klemens [Institute of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen 35390, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany)] [Institute of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen 35390, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany); Durante, Marco [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291, Germany and Department of Condensed Matter Physics, Darmstadt University of Technology, Darmstadt 64289 (Germany)] [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291, Germany and Department of Condensed Matter Physics, Darmstadt University of Technology, Darmstadt 64289 (Germany); Engenhart-Cabillic, Rita [Medical Faculty of Philipps-University Marburg, Marburg 35032, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany)] [Medical Faculty of Philipps-University Marburg, Marburg 35032, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany)

2013-11-15T23:59:59.000Z

123

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

124

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

125

Experimental Determination of the Effect of the Ratio of B/Al...  

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

the Effect of the Ratio of BAl on Glass Dissolution along the Nepheline (NaAlSiO4) – Experimental Determination of the Effect of the Ratio of BAl on Glass Dissolution along...

126

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

127

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

128

Measurement of the Q value of an acoustic resonator  

Science Journals Connector (OSTI)

A cylindrical acoustic resonator was externally driven at the first resonance frequency by a compression driver. The acoustic energy stored in the resonator and the power dissipated per unit time were evaluated through the simultaneous measurements of acoustic pressure and velocity, in order to determine the Q value of the resonator. The resulting Q value, being employed as a measure of the damping in a resonator, was obtained as 36. However, the Q value determined from a frequency response curve known as a conventional technique turned out to be 25, which is 30% less than that obtained in the present method. By further applying these two methods in the case of a resonator having an acoustic load inside, we present an accurate measurement of the Q value of the resonator by making full use of its definition.

Tetsushi Biwa; Yuki Ueda; Hiroshi Nomura; Uichiro Mizutani; Taichi Yazaki

2005-08-01T23:59:59.000Z

129

Theory of Acoustical Wave Propagation in Porous Media  

Science Journals Connector (OSTI)

A theory is developed for the propagation of sound waves in a rigid isotropic and homogeneous porous medium filled with a compressible fluid including both the effect of viscous dissipation and the effect of thermal comduction. With a capillaric model assumed an expression for the permeability as a function of the frequency is also given. For very low frequencies (isothermal case) and very high frequencies (adiabatic case) the results reduce to those of a theory presented by Morse [J. Acoust. Soc. Amer. 24 696 (1952)]. The present theory can be used to determine the structural parameters of a porous system at a given frequency. Attenuation and phase factors are plotted as functions of a nondimensional frequency parameter for various combinations of the characteristic constants.

P. G. Smith; R. A. Greenkorn

1971-01-01T23:59:59.000Z

130

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

131

acoustic cavitation of slightly subcritical bubbles of Mathematics, Boston University, Boston, Massachusetts 02215  

E-Print Network [OSTI]

On acoustic cavitation of slightly subcritical bubbles Anthony ¡ Harkin Department in liquids when surface tension is the dominant effect, such as submicron air bubbles in water, where

Harkin, Anthony

132

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

133

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

134

Method and apparatus for sizing and separating warp yarns using acoustical energy  

DOE Patents [OSTI]

A slashing process for preparing warp yarns for weaving operations including the steps of sizing and/or desizing the yarns in an acoustic resonance box and separating the yarns with a leasing apparatus comprised of a set of acoustically agitated lease rods. The sizing step includes immersing the yarns in a size solution contained in an acoustic resonance box. Acoustic transducers are positioned against the exterior of the box for generating an acoustic pressure field within the size solution. Ultrasonic waves that result from the acoustic pressure field continuously agitate the size solution to effect greater mixing and more uniform application and penetration of the size onto the yarns. The sized yarns are then separated by passing the warp yarns over and under lease rods. Electroacoustic transducers generate acoustic waves along the longitudinal axis of the lease rods, creating a shearing motion on the surface of the rods for splitting the yarns.

Sheen, Shuh-Haw (Naperville, IL); Chien, Hual-Te (Naperville, IL); Raptis, Apostolos C. (Downers Grove, IL); Kupperman, David S. (Oak Park, IL)

1998-01-01T23:59:59.000Z

135

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

136

A neural network analysis of concert hall acoustics  

Science Journals Connector (OSTI)

A neural network analysis using data from 51 concert halls was undertaken. The analysis related the acoustic quality of halls as judged by musicians to ten hall parameters: volume surface area number of seats length width height mean rake angle of seats a surface diffusion index stage height and extent of stage shell/enclosure. The surface diffusion index and the extent of the stage shell were determined by a group of architects who made judgments on the basis of photographs and drawings of the halls. The results of the analysis are tentative and difficult to generalize as there are so many inputs and so many possible combinations of parameters and the effect of a particular factor is in some cases neither linear nor monotonic. The results are applied to a particular hall the concert hall of the Sydney Opera House where changes are being contemplated. There are some unexpected results which at this stage give food for thought rather than the basis for action as there are obvious limitations to this work such as extraneous factors influencing judgments of acoustic quality surface diffusion estimation and extent of the stage shell and the limited number inputs used to describe the halls. ?

Fergus R. Fricke; Young G. Han

1998-01-01T23:59:59.000Z

137

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

138

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

139

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

140

Determination of sound power of coupled machines  

Science Journals Connector (OSTI)

Several procedures are available for the determination of the sound power level of machines in normal environments. Most of these give adequate results for single medium?sized equipment but difficulties arise in extending the concepts to large coupled machines. [“Evaluation of Proposed ASME PTC 36 Code for Sound Power Level Determination of Large Steam Turbine Generators ” S.E. Grabkowski J. MacDonald and T. Van Schaick (General Electric Company) to be presented at Fall 1975 ASME meeting.] Much of the problem is because the direct acoustic field of a component machine may not extend to as much as one foot from its surface due to reverberation from other components. A procedure is suggested in which all acoustic measurements are confined to surfaces near each component machine. Correction is made for the reverberant acoustic field of the entire environment. The correction procedure utilizes reverberation time determinations from impulsive noise tests; and applies a Monte Carlo approach to the problem of correcting for nearfield effects in the evaluation of sound power. An iterative computation is employed. Comparisons with free?field sound power determinations are shown.

R. J. Wells

1975-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" from the National Library of EnergyBeta (NLEBeta).
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141

CX-006029: Categorical Exclusion Determination | Department of Energy  

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

6029: Categorical Exclusion Determination 6029: Categorical Exclusion Determination CX-006029: Categorical Exclusion Determination Acoustic Effects of Hydrokinetic Tidal Turbines CX(s) Applied: B3.3, B3.6 Date: 05/25/2011 Location(s): Snohomish County, Washington Office(s): Energy Efficiency and Renewable Energy, Golden Field Office Snohomish County Public Utility District (PUD) is proposing to use Department of Energy and cost-share funding to study of the acoustic effects of hydrokinetic tidal turbines at the site of the District's Admiralty Inlet pilot project. Activities would include the purchase and configuration of instrumentation, the deployment and retrieval of the instrumentation packages on the seabed, the simulation and measurement of sound propagation by a tidal turbine, and experimentation (conducted at

142

CX-002145: Categorical Exclusion Determination | Department of Energy  

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

145: Categorical Exclusion Determination 145: Categorical Exclusion Determination CX-002145: Categorical Exclusion Determination Acoustic Effects of Hydrokinetic Tidal Turbines CX(s) Applied: B3.1, B3.3, A9 Date: 04/29/2010 Location(s): Snohomish County, Washington Office(s): Energy Efficiency and Renewable Energy, Golden Field Office Snohomish County Public Utility District (PUD) is proposing to use Department of Energy and cost-share funding to study of the acoustic effects of hydrokinetic tidal turbines at the site of the District's Admiralty Inlet pilot project. Activities would include the purchase and configuration of instrumentation, the deployment and retrieval of the instrumentation packages on the seabed, the simulation and measurement of sound propagation by a tidal turbine, and experimentation (conducted at

143

Acoustic anisotropy related to anisotropic stress conditions during formation and unloading  

Science Journals Connector (OSTI)

......Abstracts 57th Ann. Int. SEG Mtg 1987, New Orleans, Acoustic...of a sedimentation/uplift process, although real rocks often...determined by the unloading process. In the present study, acoustic...monitored throughout the entire process, thus allowing us to observe......

E. Fjaer; R. M. Holt; J. S. Rathore; B. Åhlén

1991-12-01T23:59:59.000Z

144

Ion-acoustic waves in a plasma consisting of adiabatic warm ions, nonisothermal electrons, and a weakly relativistic electron beam: Linear and higher-order nonlinear effects  

SciTech Connect (OSTI)

The nonlinear propagation of finite amplitude ion acoustic solitary waves in a plasma consisting of adiabatic warm ions, nonisothermal electrons, and a weakly relativistic electron beam is studied via a two-fluid model. A multiple scales technique is employed to investigate the nonlinear regime. The existence of the electron beam gives rise to four linear ion acoustic modes, which propagate at different phase speeds. The numerical analysis shows that the propagation speed of two of these modes may become complex-valued (i.e., waves cannot occur) under conditions which depend on values of the beam-to-background-electron density ratio {alpha}, the ion-to-free-electron temperature ratio {sigma}, and the electron beam velocity v{sub 0}; the remaining two modes remain real in all cases. The basic set of fluid equations are reduced to a Schamel-type equation and a linear inhomogeneous equation for the first and second-order potential perturbations, respectively. Stationary solutions of the coupled equations are derived using a renormalization method. Higher-order nonlinearity is thus shown to modify the solitary wave amplitude and may also deform its shape, even possibly transforming a simple pulse into a W-type curve for one of the modes. The dependence of the excitation amplitude and of the higher-order nonlinearity potential correction on the parameters {alpha}, {sigma}, and v{sub 0} is numerically investigated.

Esfandyari-Kalejahi, A. [Faculty of Science, Department of Physics, Azerbaijan University of Tarbiat Moallem, 51745-406 Tabriz (Iran, Islamic Republic of); Kourakis, I. [Center for Plasma Physics (CPP), Department of Physics and Astronomy, Queen's University Belfast, BT7 1 NN Northern Ireland (United Kingdom); Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Shukla, P. K. [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

2008-02-15T23:59:59.000Z

145

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

146

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

147

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

148

Cross-Dipole Acoustic Log At Alum Area (Moos & Ronne, 2010) | Open Energy  

Open Energy Info (EERE)

Dipole Acoustic Log At Alum Area (Moos & Ronne, 2010) Dipole Acoustic Log At Alum Area (Moos & Ronne, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Cross-Dipole Acoustic Log At Alum Geothermal Area (Moos & Ronne, 2010) Exploration Activity Details Location Alum Geothermal Area Exploration Technique Cross-Dipole Acoustic Log Activity Date Usefulness useful DOE-funding Unknown Notes A crossed-dipole acoustic log detected stress induced anisotropy in the sediments, and also appeared to be able to identify and orient steeply dipping, compliant and therefore possibly conductive fractures in basement rocks. Because the shear-wave velocity was extremely low throughout most of the sedimentary section dipole data was required for its determination. The analysis results, which included a stress determination based on an

149

Multi-scale Modeling Approach to Acoustic Emission during Plastic Deformation  

E-Print Network [OSTI]

We address the long standing problem of the origin of acoustic emission commonly observed during plastic deformation. We propose a frame-work to deal with the widely separated time scales of collective dislocation dynamics and elastic degrees of freedom to explain the nature of acoustic emission observed during the Portevin-Le Chatelier effect. The Ananthakrishna model is used as it explains most generic features of the phenomenon. Our results show that while acoustic emission bursts correlated with stress drops are well separated for the type C serrations, these bursts merge to form nearly continuous acoustic signals with overriding bursts for the propagating type A bands.

Jagadish Kumar; G. Ananthakrishna

2011-02-20T23:59:59.000Z

150

Effect of trapped electron on the dust ion acoustic waves in dusty plasma using time fractional modified Korteweg-de Vries equation  

SciTech Connect (OSTI)

The time fractional modified Korteweg-de Vries (TFMKdV) equation is solved to study the nonlinear propagation of small but finite amplitude dust ion-acoustic (DIA) solitary waves in un-magnetized dusty plasma with trapped electrons. The plasma is composed of a cold ion fluid, stationary dust grains, and hot electrons obeying a trapped electron distribution. The TFMKdV equation is derived by using the semi-inverse and Agrawal's methods and then solved by the Laplace Adomian decomposition method. Our results show that the amplitude of the DIA solitary waves increases with the increase of time fractional order ?, the wave velocity v{sub 0}, and the population of the background free electrons ?. However, it is vice-versa for the deviation from isothermality parameter b, which is in agreement with the result obtained previously.

Nazari-Golshan, A. [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)] [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Nourazar, S. S. [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of) [Department of Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Department of Mechanical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

2013-10-15T23:59:59.000Z

151

Determination of effective water vapor diffusion coefficient in pemfc gas diffusion layers  

E-Print Network [OSTI]

route from the cathode catalyst layer to the cathode flow channels. Water can be removed from the cellDetermination of effective water vapor diffusion coefficient in pemfc gas diffusion layers Jacob M: Water vapor diffusion PEMFC Water management GDL Diffusivity MPL a b s t r a c t The primary removal

Kandlikar, Satish

152

Determinants and Income Effects of Commuting and Migration An empirical analysis for Germany after Unification  

E-Print Network [OSTI]

Determinants and Income Effects of Commuting and Migration An empirical analysis for Germany after differentials between East and West Germany led to massive commuting and migration flows. In this paper we: Human capital and income, Germany, commuting, migration, GSOEP JEL No.: J31, J61, O15 Address: Institute

Pfeifer, Holger

153

Effects of Shear Rate on Propagation of Blood Clotting Determined Using Microfluidics and Numerical Simulations  

E-Print Network [OSTI]

Effects of Shear Rate on Propagation of Blood Clotting Determined Using Microfluidics and Numerical-ismagilov@uchicago.edu Abstract: This paper describes microfluidic experiments with human blood plasma and numerical simulations removed. In addition, these results demonstrate the utility of simplified mechanisms and microfluidics

Ismagilov, Rustem F.

154

X-ray bandwidth: Determination by on-edge absorption and effect on various absorption experiments  

E-Print Network [OSTI]

X-ray bandwidth: Determination by on-edge absorption and effect on various absorption experiments of an x-ray source is increasingly important in fundamental experi- ments and critical applications. The bandwidth of an x-ray beam, selected from a synchrotron radiation spectrum for example, ultimately defines

Chantler, Christopher T.

155

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

156

Dark Energy Constraints from Baryon Acoustic Oscillations  

Science Journals Connector (OSTI)

Baryon acoustic oscillations (BAOs) in the galaxy power spectrum allow us to extract the scale of the comoving sound horizon at recombination, a cosmological standard ruler accurately determined by the cosmic microwave background anisotropy data. We examine various issues important in the use of BAOs to probe dark energy. We find that if we assume a flat universe and priors on ?m, ?mh2, and ?bh2 as expected from the Planck mission, the constraints on dark energy parameters (w0, w') scale much less steeply with survey area than (area)-1/2 for a given redshift range. The constraints on the dark energy density ?X(z), however, do scale roughly with (area)-1/2 due to the strong correlation between H(z) and ?m (which reduces the effect of priors on ?m). Dark energy constraints from BAOs are very sensitive to the assumed linear scale of matter clustering and the redshift accuracy of the survey. For a BAO survey with 0.5 ? z ? 2, ? (R) = 0.4 [corresponding to kmax (z = 0) = 0.086 h Mpc-1], and ?z/ (1 + z) = 0.001, we find = (0.115,0.183) and (0.069, 0.104) for survey areas of 1000 and 10,000 deg2, respectively. We find that it is critical to minimize the bias in the scale estimates in order to derive reliable dark energy constraints. For a 1000 (10,000) deg2 BAO survey, a 1 ? bias in ln H (z) leads to a 2 ? (3 ?) bias in w'. The bias in w' due to the same scale bias from ln DA (z) is slightly smaller and opposite in sign. The results from this paper will be useful in assessing different proposed BAO surveys and guiding the design of optimal dark energy detection strategies.

Yun Wang

2006-01-01T23:59:59.000Z

157

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

158

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

159

Beat phenomenon at the arrival of a guided mode in a semi-infinite acoustic duct  

E-Print Network [OSTI]

. This eigen value problem has an infinite discrete number of solutions N (x, y) with the modal wave numbers NBeat phenomenon at the arrival of a guided mode in a semi-infinite acoustic duct P. Gatignola , M at an initial time in the terminal section of a semi-infinite acoustic duct, will undergo dispersion effects

Paris-Sud XI, Université de

160

Interim guidance on determination and use of water-effect ratios for metals  

SciTech Connect (OSTI)

When a site-specific aquatic life criterion is derived for a metal, an adjustment procedure based on the toxicological determination of a water-effect ratio (WER) may be used to account for a difference between the toxicity of the metal in laboratory dilution water and its toxicity in the water at the site. The guidance contained herein replaces previous agency guidance concerning (1) the determination of WERs for use in the derivation of site-specific aquatic life criteria for metals and (2) the Recalculation Procedure. The guidance is designed to apply to metals, but the principles apply to most pollutants.

Stephan, C.E.; Peltier, W.H.; Hansen, D.J.; Delos, C.G.; Chapman, G.A.

1994-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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

Microsoft PowerPoint - Subsea_Acoustics v5.ppt  

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

Acoustic Impacts on Marine Mammals Acoustic Impacts on Marine Mammals from Subsea Oil & Gas Processing DOE Strategy to Address Noise from Subsea Petroleum Processing Technologies DOE Strategy to Address Noise from Subsea Petroleum Processing Technologies Noise Types & Thresholds High Level, Intermittent Low Level, Continuous MMS Workshop Nov. 17-19, 2009 Boston, MA Marine Mammals and Noise Marine Mammal Commission March 2007 Advisory Committee on Acoustic Impacts on Marine Mammals Marine Mammal Commission February 2006 Effects of Subsea Processing on Deepwater Environments in the Gulf of Mexico Minerals Management Service May 2008 Addressing the Effects of Human- Generated Sound on Marine Life Joint Subcommittee on Ocean Science & Technology (JSOST) January 2009 Facilities Utilizing Subsea Petroleum Processing Technologies

162

Determination of boron isotope ratios by Zeeman effect background correction-graphite furnace atomic absorption spectrometry  

Science Journals Connector (OSTI)

A new method for the determination of isotopic ratio of boron using Zeeman effect background correction-graphite furnace atomic absorption spectrometry with conventional atomizer and natural-boron hollow cathode source is described. The isotope-shift Zeeman effect at 208.9 nm is utilized for isotopic ratio determination. At a given concentration of total boron, the net absorbance decreases linearly with increasing 10B/11B ratio. The absorbances are recorded at the field strength of 1.0 T. The isotope ratios measured by the proposed method were in good agreement with the results obtained by inductively coupled plasma-quadruple mass spectrometry or thermal ionization mass spectrometry. The present method is fairly fast and less expensive compared to the above techniques and is quite suitable for plant environments.

S. Thangavel; S.V. Rao; K. Dash; J. Arunachalam

2006-01-01T23:59:59.000Z

163

Determination of the Pt spin diffusion length by spin-pumping and spin Hall effect  

SciTech Connect (OSTI)

The spin diffusion length of Pt at room temperature and at 8 K is experimentally determined via spin pumping and spin Hall effect in permalloy/Pt bilayers. Voltages generated during excitation of ferromagnetic resonance from the inverse spin Hall effect and anisotropic magnetoresistance effect were investigated with a broadband approach. Varying the Pt layer thickness gives rise to an evolution of the voltage line shape due to the superposition of the above two effects. By studying the ratio of the two voltage components with the Pt layer thickness, the spin diffusion length of Pt can be directly extracted. We obtain a spin diffusion length of ?1.2 nm at room temperature and ?1.6 nm at 8 K.

Zhang, Wei; Pearson, John E.; Hoffmann, Axel [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)] [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Vlaminck, Vincent [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Colegio de Ciencias e Ingenería, Universidad San Fransciso de Quito, Quito (Ecuador); Divan, Ralu [Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States)] [Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States); Bader, Samuel D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States)

2013-12-09T23:59:59.000Z

164

Determination of the effective stress law for permeability and deformation in low-permeability rocks  

SciTech Connect (OSTI)

This paper reports that laboratory experiments were performed to determine the effective stress law of tight sandstones and chalk for permeability and deformation. Permeability and volumetric strain data were taken at various stresses and pore pressures and were analyzed with a statistical model-building approach. Results show that the effective stress laws for both processes are variable with stress and pressure, depend on the material, and do not agree well with present theories. This may be applied for a greater understanding of oil reservoir formations.

Warpinski, N.R.; Teufel, L.W. (Sandia National Lab. (US))

1992-06-01T23:59:59.000Z

165

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

166

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

167

The role of estrogen in turtle sex determination and the effect of PCBs  

SciTech Connect (OSTI)

Gonadal sex is fixed at fertilization by specific chromosomes, a process known as genotypic sex determination (GSD). Only after the gonad is formed do hormones begin to exert an influence that modifies specific structures that eventually will differ between the sexes. Many egg-laying reptiles do not exhibit GSD but rather depend on the temperature of the incubating egg to determine the gonadal sex of the offspring, a process termed temperature-dependent sex determination (TSD). Research on TSD indicates that gonadal sex is not irrevocably set by the genetic composition inherited at fertilization but depends ultimately on which genes encoding for steroidogenic enzymes and hormone receptors are activated during the midtrimester of embryonic development by temperature. Incubation temperature modifies the activity as well as the temporal and spatial sequence of enzymes and hormone receptors to determine gonad type. Estrogen is the physiologic equivalent of incubation temperature and the proximate cue that initiates female sex determination. increasing evidence indicates some polychlorinated biphenyl (PCB) compounds are capable of disrupting reproductive and endocrine function in fish, birds, and mammals, including humans. Reproductive disorders resulting from exposure to these xenobiotic compounds may include reductions in fertility, hatch rate in fish and birds, and viability of offspring, as well as alterations in hormone levels or adult sexual behaviors. Research on the mechanism through which these compounds may be acting to alter reproductive function indicates estrogenic activity, by which the compounds may be altering sexual differentiation. In TSD turtles, the estrogenic effect of some PCBs reverses gonadal sex in individuals incubating at an otherwise male-producing temperature. Furthermore, certain PCBs are synergistic in their effect at very low concentrations. 19 refs., 3 figs., 1 tab.

Crews, D.; Bergeron, J.M. [Univ. of Texas, Austin, TX (United States); McLachlan, J.A. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States)

1995-10-01T23:59:59.000Z

168

CX-006240: Categorical Exclusion Determination  

Broader source: Energy.gov [DOE]

Acoustic Effects of Hydrokinetic Tidal TurbinesCX(s) Applied: B3.1, B3.3Date: 07/15/2011Location(s): WashingtonOffice(s): Energy Efficiency and Renewable Energy, Golden Field Office

169

Acoustic propagation characteristics of the estuarine salt wedge  

Science Journals Connector (OSTI)

The estuarine environment often hosts a salt wedge—a layer of denser seawater advected by the rising tide under fresh water discharged by the river. The nature of the stratification is a function of the tide's range and speed of advance river discharge volumetric flow rate and river mouth morphology. The competing effects of temperature and salinity on sound speed present the question: Is the salt wedge acoustically observable? Using temperature and salinity profiles collected in situ numerical results show that the salt wedge can impact acoustic propagation. Acoustically this environment consists of two isospeed layers separated by a thin gradient. While this three-layer very shallow water acoustic waveguide is typically dominated by high angle multipath propagation refraction occurring in the gradient layer allows some low-angle energy from near-surface sources to be trapped in the upper layer. Acoustic fluctuations observed at an upstream or downstream receiver depend upon the interaction between the advancing and receding tide and the river discharge which can include the presence of internal waves propagating along the top of the salt wedge.

2013-01-01T23:59:59.000Z

170

Shelf?break tidally induced environmental influences on acoustic propagation  

Science Journals Connector (OSTI)

Continuous wave propagation in the 100–500 Hz band in littoral regions depends upon both time?dependent oceanography and bathymetry. The environmental influences interact nonlinearly in the acoustical time variation especially since the diurnal tidesurface height changes creates time?dependent total water depth. A submesoscale hydrodynamic model developed by Shen and Evans is used with tidal forcing and a simple shelf?break bathymetry to produce surface height variation and internal wave activity due to internal tide in a stratified ocean environment. A three?dimensional parabolic equation acoustic model is used to acoustically probe this environment at various bearings relative to the shelf break and the resulting internal tidal dynamics. In particular the acoustical results are examined for three?dimensional effects such as horizontal refraction. First the influence of bathymetry alone is shown and then compared to the full environment due to hydrodynamic action. The relative influences will then be compared by various measures such as modal decomposition acoustic energy summed over depth and signal gain degradation. [This research is sponsored by the ONR.

2004-01-01T23:59:59.000Z

171

Acoustic propagation characteristics of the estuarine salt wedge  

Science Journals Connector (OSTI)

The estuarine environment often hosts a salt wedge-a layer of denser seawater advected by the rising tide under fresh water discharged by the river. The nature of the stratification is a function of the tide's range and speed of advance river discharge volumetric flow rate and river mouth morphology. The competing effects of temperature and salinity on sound speed present the question: Is the salt wedge acoustically observable? Using temperature and salinity profiles collected in situ numerical results show that the salt wedge can impact acoustic propagation. Acoustically this environment can be approximated by two isospeed layers separated by a thin gradient. While this three-layer very shallow water acoustic waveguide is typically dominated by high angle multipath propagation refraction occurring in the gradient layer allows low-angle energy from near-surface sources to be trapped above the gradient and creates a shadow zone below the gradient. Energy from near-bottom sources is refracted to higher angles and attenuated more quickly. Acoustic fluctuations observed at an upstream/downstream receiver depend upon the presence/absence of bedforms and the interaction between the advancing/receding tide and the river discharge which can include the presence of internal waves propagating along the top of the salt wedge.

D. B. Reeder

2013-01-01T23:59:59.000Z

172

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

173

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

174

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

175

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

176

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

177

Drift and ion acoustic wave driven vortices with superthermal electrons  

SciTech Connect (OSTI)

Linear and nonlinear analysis of coupled drift and acoustic mode is presented in an inhomogeneous electron-ion plasma with {kappa}-distributed electrons. A linear dispersion relation is found which shows that the phase speed of both the drift wave and the ion acoustic wave decreases in the presence of superthermal electrons. Several limiting cases are also discussed. In the nonlinear regime, stationary solutions in the form of dipolar and monopolar vortices are obtained. It is shown that the condition for the boundedness of the solution implies that the speed of drift wave driven vortices reduces with increase in superthermality effect. Ignoring density inhomogeniety, it is investigated that the lower and upper limits on the speed of the ion acoustic driven vortices spread with the inclusion of high energy electrons. The importance of results with reference to space plasmas is also pointed out.

Ali Shan, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, QAU Campus, 44000 Islamabad (Pakistan); Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan); Haque, Q. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, QAU Campus, 44000 Islamabad (Pakistan)

2012-08-15T23:59:59.000Z

178

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

179

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

180

Binary Contamination in the SEGUE Sample: Effects on SSPP Determinations of Stellar Atmospheric Parameters  

Science Journals Connector (OSTI)

We examine the effects that unresolved binaries have on the determination of various stellar atmospheric parameters for targets from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) using numerical modeling, a grid of synthetic spectra, and the SEGUE Stellar Parameter Pipeline (SSPP). The SEGUE survey, a component of the Sloan Digital Sky Survey-II (SDSS-II) project focusing on Galactic structure, provides medium resolution spectroscopy for over 200,000 stars of various spectral types over a large area on the sky. To model undetected binaries that may be in this sample, we use a variety of mass distributions for the primary and secondary stars in conjunction with empirically determined relationships for orbital parameters to determine the fraction of G - K dwarf stars, defined by SDSS color cuts as having 0.48 ? (g – r)0 ? 0.75, that will be blended with a secondary companion. We focus on the G-K dwarf sample in SEGUE as it records the history of chemical enrichment in our galaxy. To determine the effect of the secondary on the spectroscopic parameters, specifically effective temperature, surface gravity, metallicity, and [?/Fe], we synthesize a grid of model spectra from 3275 to 7850 K and [Fe/H] = –0.5 to –2.5 from MARCS model atmospheres using TurboSpectrum. These temperature and metallicity ranges roughly correspond to a stellar mass range of 0.1-1.0 M ?. We assume that both stars in the pair have the same metallicity. We analyze both "infinite" signal-to-noise ratio (S/N) models and degraded versions of the spectra, at median S/N of 50, 25, and 10. By running individual and combined spectra (representing the binaries) through the SSPP, we determine that ~10% of the blended G - K dwarf pairs with S/N ? 25 will have their atmospheric parameter determinations, in particular temperature and metallicity, noticeably affected by the presence of an undetected secondary; namely, they will be shifted beyond the expected SSPP uncertainties. Shifts in [Fe/H] largely result from the shifts in temperature caused by a secondary. The additional uncertainty from binarity in targets with S/N ? 25 is ~80 K in temperature and ~0.1 dex in [Fe/H]. The effect on surface gravity and [?/Fe] is even smaller. As the S/N of targets decreases, the uncertainties from undetected secondaries increase. For S/N = 10, 40% of the G-K dwarf sample is shifted beyond expected uncertainties for this S/N in effective temperature and/or metallicity. To account for the additional uncertainty from binary contamination at an S/N ~ 10, the most extreme scenario, uncertainties of ~140 K and ~0.17 dex in [Fe/H] must be added in quadrature to the published uncertainties of the SSPP.

Katharine J. Schlesinger; Jennifer A. Johnson; Young Sun Lee; Thomas Masseron; Brian Yanny; Constance M. Rockosi; B. Scott Gaudi; Timothy C. Beers

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

182

Cohesion enhancing effect of magnesium in aluminum grain boundary: A first-principles determination  

SciTech Connect (OSTI)

The effect of magnesium on grain boundary cohesion in aluminum was investigated by means of first-principles calculations using the Rice-Wang model [Rice and Wang, Mater. Sci. Eng. A 107, 23 (1989)]. It is demonstrated that magnesium is a cohesion enhancer with a potency of -0.11 eV/atom. It is further determined through electronic structure and bonding character analysis that the cohesion enhancing property of magnesium is due to a charge transfer mechanism which is unusually strong and overcomes the negative result of the size effect mechanism. Consistent with experimental results, this work clarifies the controversy and establishes that Mg segregation does not contribute to stress corrosion cracking in Al alloys.

Zhang Shengjun; Freeman, Arthur J. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States); Kontsevoi, Oleg Y. [Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States); Olson, Gregory B. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)

2012-06-04T23:59:59.000Z

183

Methods and apparatus for non-acoustic speech characterization and recognition  

DOE Patents [OSTI]

By simultaneously recording EM wave reflections and acoustic speech information, the positions and velocities of the speech organs as speech is articulated can be defined for each acoustic speech unit. Well defined time frames and feature vectors describing the speech, to the degree required, can be formed. Such feature vectors can uniquely characterize the speech unit being articulated each time frame. The onset of speech, rejection of external noise, vocalized pitch periods, articulator conditions, accurate timing, the identification of the speaker, acoustic speech unit recognition, and organ mechanical parameters can be determined.

Holzrichter, John F. (Berkeley, CA)

1999-01-01T23:59:59.000Z

184

Symmetrical and anti-symmetrical coherent perfect absorption for acoustic waves  

SciTech Connect (OSTI)

We investigate tunable acoustic absorption enabled by the coherent control of input waves. It relies on coherent perfect absorption originally proposed in optics. By designing appropriate acoustic metamaterial structures with resonating effective bulk modulus or density, we show that complete absorption of incident waves impinging on the metamaterial can be achieved for either symmetrical or anti-symmetrical inputs in the forward and backward directions. By adjusting the relative phase between the two incident beams, absorption can be tuned effectively from unity to zero, making coherent control useful in applications like acoustic modulators, noise controllers, transducers, and switches.

Wei, Pengjiang; Croënne, Charles; Tak Chu, Sai [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Li, Jensen, E-mail: j.li@bham.ac.uk [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom)

2014-03-24T23:59:59.000Z

185

Acoustic normal mode fluctuation statistics in the 1995 SWARM internal wave scattering experiment  

Science Journals Connector (OSTI)

In order to understand the fluctuations imposed upon low frequency (50 to 500 Hz) acoustic signals due to coastal internal waves a large multilaboratory multidisciplinary experiment was performed in the Mid-Atlantic Bight in the summer of 1995. This experiment featured the most complete set of environmental measurements (especially physical oceanography and geology) made to date in support of a coastal acoustics study. This support enabled the correlation of acoustic fluctuations to clearly observed ocean processes especially those associated with the internal wave field. More specifically a 16 element WHOI vertical line array (WVLA) was moored in 70 m of water off the New Jersey coast. Tomography sources of 224 Hz and 400 Hz were moored 32 km directly shoreward of this array such that an acoustic path was constructed that was anti-parallel to the primary onshore propagation direction for shelf generated internal wavesolitons. These nonlinear internal waves produced in packets as the tide shifts from ebb to flood produce strong semidiurnal effects on the acoustic signals at our measurement location. Specifically the internal waves in the acoustic waveguide cause significant coupling of energy between the propagating acoustic modes resulting in broadband fluctuations in modal intensity travel-time and temporal coherence. The strong correlations between the environmental parameters and the internal wave field include an interesting sensitivity of the spread of an acoustic pulse to solitons near the receiver.

Robert H. Headrick; James F. Lynch; John N. Kemp; Arthur E. Newhall; Keith von der Heydt; John Apel; Mohsen Badiey; Ching-sang Chiu; Steve Finette; Marshall Orr; Bruce Pasewark; Alton Turgot; Steve Wolf; Dirk Tielbuerger

2000-01-01T23:59:59.000Z

186

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

187

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

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

43.30.Ft, 43... short range was deemed desirable for isolating the effects of shallow water internal waves on acoustic... internal waves are not un- usual and it was ......

188

Acoustics in the Klebanoff-Saric Wind Tunnel: Background Identification, Forcing, and Active Control  

E-Print Network [OSTI]

that dominate the pressure spectrum. Directional separation of waves in the test section revealed that motor and blade passing noise travels primarily upstream into the test section. Finally, the acoustic treatments in the plenum are effective at removing sound...

Kuester, Matthew

2012-07-16T23:59:59.000Z

189

Overstability of acoustic waves in strongly magnetized anisotropic magnetohydrodynamic shear flows  

SciTech Connect (OSTI)

We present a linear stability analysis of the perturbation modes in anisotropic magnetohydrodynamic (MHD) flows with velocity shear and strong magnetic field. Collisionless or weakly collisional plasma is described within the 16-momentum MHD fluid closure model that takes into account not only the effect of pressure anisotropy but also the effect of anisotropic heat fluxes. In this model, the low frequency acoustic wave is revealed into a standard acoustic mode and higher frequency fast thermo-acoustic and lower frequency slow thermo-acoustic waves. It is shown that thermo-acoustic waves become unstable and grow exponentially when the heat flux parameter exceeds some critical value. It seems that velocity shear makes thermo-acoustic waves overstable even at subcritical heat flux parameters. Thus, when the effect of heat fluxes is not profound acoustic waves will grow due to the velocity shear, while at supercritical heat fluxes the flow reveals compressible thermal instability. Anisotropic thermal instability should be also important in astrophysical environments, where it will limit the maximal value of magnetic field that a low density ionized anisotropic flow can sustain.

Uchava, E. S. [Abastumani Astrophysical Observatory, Ilia State University, Tbilisi, Georgia (United States); Nodia Institute of Geophysics, Javakhishvili Tbilisi State University, Tbilisi, Georgia (United States); Faculty of Exact and Natural Sciences, Javakhishvili Tbilisi State University, 3 Chavchavadze Ave., Tbilisi 0179, Georgia (United States); Shergelashvili, B. M. [Institut für Theoretische Physik IV: Weltraum- und Astrophysik, Ruhr-Universitat Bochum, 44780 Bochum (Germany); Abastumani Astrophysical Observatory, Ilia State University, Tbilisi, Georgia (United States); CODeS, KU Leuven Campus Kortrijk, E. Sabbelaan 53, 8500 Kortrijk (Belgium); Tevzadze, A. G. [Faculty of Exact and Natural Sciences, Javakhishvili Tbilisi State University, 3 Chavchavadze Ave., Tbilisi 0179, Georgia (United States); Poedts, S. [Centre for Mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium); Leuven Mathematical Modeling and Computational Science Center (LMCC), KU Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium)

2014-08-15T23:59:59.000Z

190

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

191

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

192

In-process acoustic emission monitoring of dissimilar metal welding: Final report  

SciTech Connect (OSTI)

A system to provide real-time, in-process acoustic emission monitoring to detect and locate flaws in bimetallic welds has been demonstrated. This system could provide reliable inspection of critical welds in cases where conventional NDE would be costly or impossible to apply. Tests were completed on four sample welds to determine the sensitivity of the system. Artificial flaws were introduced into two test samples and the acoustic emission results were verified by radiography and visual inspection techniques.

Not Available

1989-08-01T23:59:59.000Z

193

Physiological acoustics and health  

Science Journals Connector (OSTI)

This paper reviews work on the assessment of the damaging effect of noise on man’s auditory system the degree to which the auditory system interacts directly with the autonomic system of the body noise as the sole or contributory cause of general (nonauditory) physiological and psychological ill health in communities and the effect of noise on general health in industry.

Karl D. Kryter

1980-01-01T23:59:59.000Z

194

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

195

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):...

196

Inverse-kinematics proton scattering on $^{50}$Ca: Determining effective charges using complementary probes  

E-Print Network [OSTI]

We have performed measurements of the $0_\\mathrm{g.s.}^+ \\rightarrow 2_1^+$ excitations in the neutron-rich isotopes $^{48,50}$Ca via inelastic proton scattering on a liquid hydrogen target, using the GRETINA $\\gamma$-ray tracking array. A comparison of the present results with those from previous measurements of the lifetimes of the $2_1^+$ states provides us the ratio of the neutron and proton matrix elements for the $0_\\mathrm{g.s.}^+ \\rightarrow 2_1^+$ transitions. These results allow the determination of the ratio of the proton and neutron effective charges to be used in shell model calculations of neutron-rich isotopes in the vicinity of $^{48}$Ca.

L. A. Riley; M. L. Agiorgousis; T. R. Baugher; D. Bazin; M. Bowry; P. D. Cottle; F. G. DeVone; A. Gade; M. T. Glowacki; K. W. Kemper; E. Lunderberg; D. M. McPherson; S. Noji; F. Recchia; B. V. Sadler; M. Scott; D. Weisshaar; R. G. T. Zegers

2014-07-20T23:59:59.000Z

197

Magneto-Acoustic Wave Oscillations in Solar Spicules  

E-Print Network [OSTI]

Some observations suggest that solar spicules show small amplitude and high frequency oscillations of magneto-acoustic waves, which arise from photospheric granular forcing. We apply the method of MHD seismology to determine the period of kink waves. For this purposes, the oscillations of a magnetic cylinder embedded in a field-free environment is investigated. Finally, diagnostic diagrams displaying the oscillatory period in terms of some equilibrium parameters are provided to allow a comparison between theoretical results and those coming from observations.

Ajabshirizadeh, A; Koutchmy, S

2008-01-01T23:59:59.000Z

198

Magneto-Acoustic Wave Oscillations in Solar Spicules  

E-Print Network [OSTI]

Some observations suggest that solar spicules show small amplitude and high frequency oscillations of magneto-acoustic waves, which arise from photospheric granular forcing. We apply the method of MHD seismology to determine the period of kink waves. For this purposes, the oscillations of a magnetic cylinder embedded in a field-free environment is investigated. Finally, diagnostic diagrams displaying the oscillatory period in terms of some equilibrium parameters are provided to allow a comparison between theoretical results and those coming from observations.

A. Ajabshirizadeh; E. Tavabi; S. Koutchmy

2008-06-09T23:59:59.000Z

199

Experimental determination of the effective structure-function parameter for atmospheric turbulence  

Science Journals Connector (OSTI)

The effective structure-function parameter for scattering by atmospheric turbulentvelocityfluctuations has normally been assumed to be C eff 2 =4C V 2 /c 0 2 where C V 2 is the velocitystructure-function parameter and c 0 the sound speed. However a new derivation by Ostashev [WavesRandom Media4 403–428 (1994)] which takes into account the vectorial nature of the wind velocity field suggests that C eff 2 =22C V 2 /3c 0 2 . An experiment was designed to determine the correct value of the coefficient. Sound-pressure amplitude variances were monitored for several discrete frequencies between 380 and 3800 Hz at distances up to 250 m. Cup and hot-wire anemometers were used to determine C V 2 . A theory for scattering by inertial-subrange turbulence was then used to calculate the C eff 2 coefficient from the amplitude variance and C V 2 . Datasets recorded under different atmospheric conditions yielded different relationships between the coefficients and failed to verify either the 4 or 22/3 value. Some possible explanations for this behavior are discussed including the need for more realistic meteorological modeling.

D. K. Wilson; D. I. Havelock; M. Heyd; M. J. Smith; J. M. Noble; H. J. Auvermann

1999-01-01T23:59:59.000Z

200

ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS  

SciTech Connect (OSTI)

Three major goals were accomplished during this phase. First, a study was completed of the effects of stress-induced changes in anisotropic elastic moduli in sandstone. Second, a new method for measuring the anisotropic poroelastic moduli from acoustic data was developed. Third, a series of triaxial experiments were conducted on unconsolidated sands to identify pressure/stress conditions where liquefaction occurs under high confining pressures. Stress-induced changes in anisotropic Young's moduli and shear moduli were observed during deformational pathway experiments. A new method was made for the acquisition of compressional and shear wave velocities along a series of 3-dimensional raypaths through a core sample as it is subjected to deformation. Three different deformational pathway experiments were conducted. During the hydrostatic deformation experiment, little or no anisotropy was observed in either the Young's moduli or shear moduli. Significant deformational anisotropies were observed in both moduli during the uniaxial strain test and the triaxial compression experiment but each had a different nature. During the triaxial experiment the axial and lateral Young's moduli and shear moduli continued to diverge as load was applied. During the uniaxial strain experiment the anisotropy was ''locked in'' early in the loading phase but then remained steady as both the confining pressure and axial stress were applied. A new method for measuring anisotropic Biot's effective stress parameters has also been developed. The method involves measuring the compressional and shear wave velocities in the aforementioned acoustic velocity experiments while varying stress paths. For a stress-induced transversely isotropic medium the acoustic velocity data are utilized to calculate the five independent elastic stiffness components. Once the elastic stiffness components are determined these can be used to calculate the anisotropic Biot's effective stress parameters, {alpha}{sub v} and {alpha}{sub h}, using the equations of Abousleiman et al. (1996). A series of experiments have been conducted, on an initially inherently isotropic Berea sandstone rock sample, to dynamically determine these anisotropic Biot's parameters during deformational pathway experiments. Data acquired during hydrostatic, triaxial, and uniaxial strain pathway experiments indicates that Biot's effective stress parameter changes significantly if the applied stresses are not hydrostatic. Variations, as large as 20% between the axial (vertical) and lateral (horizontal) Biot's effective stress parameters, were observed in some experiments. A series of triaxial compression experiments have been conducted on unconsolidated sand (Oil Creek sand) to determine the pressure/stress conditions which would be favorable for liquefaction. Liquefaction of geopressured sands is thought to be one of the major causative mechanisms of damaging shallow water flows. The experiments were developed to determine if: (1) liquefaction could be made to occur in this particular sand at high confining pressures, and (2) the state of liquefication had the same nature at high pressure conditions typical of shallow water flows as it does in low confining pressure soil mechanics tests. A series of undrained triaxial experiments were successfully used to document that the Oil Creek sand could undergo liquefaction. The nature (i.e., the shape of the deformational pathway in mean pressure/shear stress space) was very similar to those observed in soil mechanics experiments. The undrained triaxial experiments also indicated that this sand would strain soften at relatively high confining pressures--a necessary precursor to liquefaction. These experiments serve as a starting point for a series of acoustic experiments to determine the signature of compressional and shear wave properties as the sand packs approach the state of liquefaction (and shallow water flows).

Thurman E. Scott, Jr., Ph.D.; Younane Abousleiman, Ph.D.; Musharraf Zaman, Ph.D., P.E.

2002-04-30T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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

Requirements for the Effective Use of the Water Resources Scientific Information Center (WRSIC) -- Determined by Field Evaluation  

E-Print Network [OSTI]

TR- 23 Vol II 1969 Requirements for Effective Use of the Water Resources Scientific Information Center (WRSIC) ? Determined by Field Evaluation E.B. Smith J.B. Herbich J.D. Benson Texas...TR- 23 Vol II 1969 Requirements for Effective Use of the Water Resources Scientific Information Center (WRSIC) ? Determined by Field Evaluation E.B. Smith J.B. Herbich J.D. Benson Texas...

Herbich, J. B.; Smith, E. B.; Benson, J. D.

1969-11-15T23:59:59.000Z

202

The effect of standard ambient conditions used for the determination of road load to predict vehicle fuel economy  

E-Print Network [OSTI]

THE EFFECT OF STANDARD AN1BIENT CONDITIONS USED FOR THE DETERMINATION OF ROAD LOAD TO PREDICT VEHICLE FUEL ECONOMY A Thesis by Michael Lee Love Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 198Z Major Subject: Mechanical Engineering THE EFFECT OF STANDARD AMBIENT CONDITIONS USED FOR THE DETERMINATION OF ROAD LOAD TO PREDICT VEHICLE FUEL ECONOMY A Thesis by Michael Lee Love Approved...

Love, Michael Lee

2012-06-07T23:59:59.000Z

203

Impact on acoustic propagation by internal waves and tides in the region of shelf and slope.  

Science Journals Connector (OSTI)

Internal waves (IWS) and tidal activities were investigated in the South China Sea (SCS) and the northeastern seas of Taiwan. These oceanic processes cause large fluctuations and impact on underwater acoustic propagation. These effects include two?dimensional (2?D) and three?dimensional (3?D) effects. The 2?D and 3?D effects are related to the angle between the directions of sound propagation and IW front. When the IW front are from 20 to 90 deg with respect to the acoustic propagation direction acoustic mode coupling is the dominant factor which could be sufficiently predicted by the N×2D simulations. Acoustic energy is exchanged between modes and is re?distributed among the water columns. However when the angles between the wave front and the acoustic wave propagation are 0–20 deg the horizontal refraction effect dominates over mode coupling and the fully 3?D calculation is needed. The acoustic energy would be refracted as a consequence resulting in energy focusing and defocusing. These effects are clearly seen by the series of data collected in the SCS and the region of Northern East of Taiwan. Computer modeling results are used to manifest experiment data results in this research. [This work is supported by National Science Council of Taiwan.

Chi?Fang Chen; Yung?Sheng Linus Chiu; Yuan?Ying Chang

2009-01-01T23:59:59.000Z

204

Applications of beamforming and acoustic holography in an anechoic tank with surface reflections  

Science Journals Connector (OSTI)

Recently our institute KRISO/KORDI constructed a small anechoic tank which has an anechoic lining at the four walls and bottom. Because surface reflections still occur special care must be taken for acoustic measurements and array signal processing for example source localization and acoustic holography. In this paper the effects of the surface reflections to the array signal processing methods are investigated. First estimated errors by both methods are analyzed for various measurement parameters. Beamforming experiments with vertical line arrays are performed. Holographic reconstruction of simple and complex acoustic sources is also performed to compare the true and estimated results.

2004-01-01T23:59:59.000Z

205

Excitation of kinetic geodesic acoustic modes by drift waves in nonuniform plasmas Z. Qiu, L. Chen, and F. Zonca  

E-Print Network [OSTI]

Excitation of kinetic geodesic acoustic modes by drift waves in nonuniform plasmas Z. Qiu, L. Chen://scitation.aip.org/termsconditions. Downloaded to IP: 192.107.52.30 On: Thu, 06 Feb 2014 15:42:45 #12;Excitation of kinetic geodesic acoustic) Effects of system nonuniformities and kinetic dispersiveness on the spontaneous excitation of Geodesic

Zonca, Fulvio

206

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.

207

Determination of effective axion masses in the helium-3 buffer of CAST  

SciTech Connect (OSTI)

The CERN Axion Solar Telescope (CAST) is a ground based experiment located in Geneva (Switzerland) searching for axions coming from the Sun. Axions, hypothetical particles that not only could solve the strong CP problem but also be one of the favored candidates for dark matter, can be produced in the core of the Sun via the Primakoff effect. They can be reconverted into X-ray photons on Earth in the presence of strong electromagnetic fields. In order to look for axions, CAST points a decommissioned LHC prototype dipole magnet with different X-ray detectors installed in both ends of the magnet towards the Sun. The analysis of the data acquired during the first phase of the experiment yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV/c{sup 2}. During the second phase, CAST extends its mass sensitivity by tuning the electron density present in the magnetic field region. Injecting precise amounts of helium gas has enabled CAST to look for axion masses up to 1.2 eV/c{sup 2}. This paper studies the determination of the effective axion masses scanned at CAST during its second phase. The use of a helium gas buffer at temperatures of 1.8 K has required a detailed knowledge of the gas density distribution. Complete sets of computational fluid dynamic simulations validated with experimental data have been crucial to obtain accurate results.

Ruz, J

2011-11-18T23:59:59.000Z

208

Determination of ?23 in long-baseline neutrino oscillation experiments with three-flavor mixing effects  

Science Journals Connector (OSTI)

We examine the accuracy of ?23 determination in future long-baseline (LBL) ?? disappearance experiments in the three-flavor mixing scheme of neutrinos. Despite that the error of sin?22?23 is indeed a few percent level at around the maximal mixing, we show that the error of physics variable s232 is large, ?(s232)/s232?10-20%, depending upon regions of ?23. The errors are severely affected by the octant degeneracy of ?23, and ?(s232) is largely amplified by the Jacobian factor relating these two variables in a region near the maximal mixing. The errors are also affected by the uncertainty due to the unknown value of ?13; ?(s232) is doubled at off maximal in the second octant of ?23 where the effect is largest. To overcome this problem, we discuss combined analysis with ?e appearance measurement in LBL experiments, or with reactor measurement of ?13. For possible relevance of subleading effects even in the next generation LBL experiments, we give a self-contained derivation of the survival probability to the next to leading order in s132 and ?m212/?m312.

Hisakazu Minakata; Masashi Sonoyama; Hiroaki Sugiyama

2004-12-23T23:59:59.000Z

209

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

210

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

211

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

212

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

213

Acoustic modeling and simulation of an urban substation  

Science Journals Connector (OSTI)

Demographic growth has often resulted in a disorganized occupation of large urban areas. Regions which were previously empty started to be populated frequently resulting in an increasingly more common proximity between residential construction and industrial installations. As a consequence very serious environmental problems have occurred including those caused by acoustic emission from industrial installations. A common problem these days is the disturbance caused by electric substations closely positioned to residential buildings. The disregard for acoustic effects during the design stage can still be observed in some of the older substation designs particularly in areas previously far from city centers. In some countries such as Brazil a systematic acoustic evaluation of substations only started in the 1980s with the main bulk of the work still under development. This paper describes some of the joint work being carried out on noise control by the researchers of Universidade Federal de Minas Gerais and CEMIG (the state power administration). The initial definition of a series of acoustic elements followed by the discussion of the governing equations is considered. The computational implementation of the resulting model is presented aimed at the definition of the most convenient noise control strategy. Finally a few results obtained at a real substation are considered including some experimental results obtained during actual operation.

Eduardo Bauzer Medeiros; Gia Kroeff

1998-01-01T23:59:59.000Z

214

The acoustics of the outdoor Shakespeare theater—Rutland, UK  

Science Journals Connector (OSTI)

The outdoor Shakespeare Amphitheatre at Tolethorpe (Rutland UK) is an unusual form of theater in that the actors perform in the open air while the audience is enclosed in a lightweight Teflon fabric auditorium. This unique format produces some unusual acoustic properties and problems. The early reflection patterns from and around the stage are quite different from a normal enclosed proscenium theater. The Teflon walls and roof while effectively acoustically transparent at low and lower midfrequencies become highly reflective at high frequencies. This not only impacts the transmission of sound through the structure but also speech transmission and intelligibility within the auditorium. The hyperbolic curved?roof surfaces and flat parallel walls were found to cause undesirable sound focusing and reflections detrimental to speech intelligibility. The acoustics of the space was investigated by means of both directional and binaural time?domain spectrometry techniques as well as more traditional acoustic measures. The paper presents the results of these measurements and outlines the remedial treatments adopted.

2000-01-01T23:59:59.000Z

215

PASSIVE WIRELESS SURFACE ACOUSTIC WAVE SENSORS FOR MONITORING SEQUESTRATION SITES CO2 EMISSION  

SciTech Connect (OSTI)

University of Pittsburgh’s Transducer lab has teamed with the U.S. Department of Energy’s National Energy Technology Laboratory (DOE NETL) to conduct a comprehensive study to develop/evaluate low-cost, efficient CO2 measuring technologies for geological sequestration sites leakage monitoring. A passive wireless CO2 sensing system based on surface acoustic wave technology and carbon nanotube nanocomposite was developed. Surface acoustic wave device was studied to determine the optimum parameters. Delay line structure was adopted as basic sensor structure. CNT polymer nanocomposite was fabricated and tested under different temperature and strain condition for natural environment impact evaluation. Nanocomposite resistance increased for 5 times under pure strain, while the temperature dependence of resistance for CNT solely was -1375ppm/?. The overall effect of temperature on nanocomposite resistance was -1000ppm/?. The gas response of the nanocomposite was about 10% resistance increase under pure CO2. The sensor frequency change was around 300ppm for pure CO2. With paralyne packaging, the sensor frequency change from relative humidity of 0% to 100% at room temperature decreased from over 1000ppm to less than 100ppm. The lowest detection limit of the sensor is 1% gas concentration, with 36ppm frequency change. Wireless module was tested and showed over one foot transmission distance at preferred parallel orientation.

Wang, Yizhong; Chyu, Minking; Wang, Qing-Ming

2012-11-30T23:59:59.000Z

216

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

217

Acoustic monitoring and signature analysis in nuclear and fossil energy generation  

Science Journals Connector (OSTI)

Acoustic monitoring and analysis in nuclear and fossil energy plants has been accompanied by transducer development for the hot environment. The Nuclear Regulatory Commission requires acoustic monitoring systems on nuclear reactors for detecting potential failures. Accelerometers are attached at critical points and their output is automatically analyzed to give warnings of loose parts or excessive vibration. In addition to providing a warning the system can monitor arrival time to be used for fault location. For use as a potential boiling detector of breeder reactors the acoustic signature of the sodium coolant boiling has been compared with background noise level. High temperature sodium?immersible microphones and waveguides for smooth energy transfer were developed for this investigation. High?temperature acoustic sensors have been used in a coal gasification plant. The presence of solids in a steam?char line has been automatically determined using passive monitoring of relative sound intensities of different frequency bands.

Henry B. Karplus

1982-01-01T23:59:59.000Z

218

Role of acoustical technology in the development of new energy sources  

Science Journals Connector (OSTI)

During the past five years considerable progress has been made in the control and abatement of excessive and/or harmful noise as well as vibration associated with the transportation construction and industrial activities and systems. This has been a definite contribution of acoustics towards improving the quality of our environment and community life alike. A similar kind of concerted effort is required whereby the know1edge of acoustics can be advantageously utilized in the development of much?needed new energy sources. Among the more challenging acoustical technologies available during exploration detection and identification of new conventional and non?conventional energy sources are those utilizing ultrasonic electroacoustics underwater acoustics and geoacoustics principles and/or disciplines. For example echo?sounding has been effectively used in the detection and assessment of marine resources. In the same way acousti?coring and seismic reflection techniques have been successfully employed during the exploration and detection phases associated with “mining geology” and “marine sediments.” However the most attractive area of new energy source development where acoustical technology can best be utilized appears to be in the exploration of active "geothermal" sites. The ground noise(seismic)measurements utilizing sensitive and precision acoustical instrumentation can tremendously accelerate development of this important untapped and nonpolluting form of natural energy. This paper reviews the interaction of acoustics with new energy resource development programs.

A. G. Jhaveri

1975-01-01T23:59:59.000Z

219

Nonplanar ion-acoustic solitary waves with superthermal electrons in warm plasma  

SciTech Connect (OSTI)

In this paper, we consider an unmagnetized plasma consisting of warm adiabatic ions, superthermal electrons, and thermal positrons. Nonlinear cylindrical and spherical modified Korteweg-de Vries (KdV) equations are derived for ion acoustic waves by using reductive perturbation technique. It is observed that an increasing positron concentration decreases the amplitude of the waves. Furthermore, the effects of the superthermal parameter (k) on the ion acoustic waves are found.

Eslami, Parvin [Department of Physics, Ferdowsi University of Mashhad (Iran, Islamic Republic of); Mottaghizadeh, Marzieh [Department of Physics, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Pakzad, Hamid Reza [Department of Physics, Bojnourd Branch, Islamic Azad University, Bojnourd (Iran, Islamic Republic of)

2011-07-15T23:59:59.000Z

220

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

222

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

223

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...

224

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

225

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.

226

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

227

Acoustic hygrometer. Final report  

SciTech Connect (OSTI)

The water vapor content for air in drier ducts, ovens, furnaces and the like is determined by a measurement of sound speed which is done by measuring the time difference between sound pulses reflected by two reflectors spaced a known distance apart in a guide tube. The transmitter-receiver is located at one end of the tube. The tube has enough number of holes to allow the hot moist air to get into the probe tube. A non-porous tube containing dry air placed in the same duct provides a similar measurement of dry-sound speed. The ratio of the two speeds of sound or the two measured time intervals is a simple function of the water vapor content practically independent of temperature thereby providing a very accurate measurement of water vapor content over an extremely wide range of temperatures. The sensor is accurate, immune to harsh environments, has an extremely low time constant, has absolutely no hysteresis and needs no calibration.

Shakkottai, P.; Kwack, E.Y.

1998-02-02T23:59:59.000Z

228

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

229

Cosmic Variance and Its Effect on the Luminosity Function Determination in Deep High z Surveys  

E-Print Network [OSTI]

We study cosmic variance in deep high redshift surveys and its influence on the determination of the luminosity function for high redshift galaxies. For several survey geometries relevant for HST and JWST instruments, we characterize the distribution of the galaxy number counts. This is obtained by means of analytic estimates via the two point correlation function in extended Press-Schechter theory as well as by using synthetic catalogs extracted from N-body cosmological simulations of structure formation. We adopt a simple luminosity - dark halo mass relation to investigate the environment effects on the fitting of the luminosity function. We show that in addition to variations of the normalization of the luminosity function, a steepening of its slope is also expected in underdense fields, similarly to what is observed within voids in the local universe. Therefore, to avoid introducing artificial biases, caution must be taken when attempting to correct for field underdensity, such as in the case of HST UDF i-dropout sample, which exhibits a deficit of bright counts with respect to the average counts in GOODS. A public version of the cosmic variance calculator based on the two point correlation function integration is made available on the web.

M. Trenti; M. Stiavelli

2007-12-03T23:59:59.000Z

230

The effects of machine parameters on residual stress determined using micro-Raman spectroscopy  

SciTech Connect (OSTI)

The effects of machine parameters on residual stresses in single point diamond turned silicon and germanium have been investigated using micro-Raman spectroscopy. Residual stresses were sampled across ductile feed cuts in < 100 > silicon and germanium which were single point diamond turned using a variety of feed rates, rake angles and clearance angles. High spatial resolution micro-Raman spectra (1{mu}m spot) were obtained in regions of ductile cutting where no visible surface damage was present. The use of both 514-5nm and 488.0nm excitation wavelengths, by virtue of their differing characteristic penetration depths in the materials, allowed determinations of stress profiles as a function of depth into the sample. Previous discussions have demonstrated that such Raman spectra will exhibit asymmetrically broadened peaks which are characteristic of the superposition of a continuum of Raman scatterers from the various depths probed. Depth profiles of residual stress were obtained using computer deconvolution of the resulting asymmetrically broadened raman spectra.

Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

1988-12-01T23:59:59.000Z

231

The Roles of Cloud Drop Effective Radius and LWP in Determining Rain Properties in Marine Stratocumulus  

SciTech Connect (OSTI)

Numerical simulations described in previous studies showed that adding cloud condensation nuclei to marine stratocumulus can prevent their breakup from closed into open cells. Additional analyses of the same simulations show that the suppression of rain is well described in terms of cloud drop effective radius (re). Rain is initiated when re near cloud top is around 12-14 um. Cloud water starts to get depleted when column-maximum rain intensity (Rmax) exceeds 0.1 mm h-1. This happens when cloud-top re reaches 14 um. Rmax is mostly less than 0.1 mm h-1 at re<14 um, regardless of the cloud water path, but increases rapidly when re exceeds 14 um. This is in agreement with recent aircraft observations and theoretical observations in convective clouds so that the mechanism is not limited to describing marine stratocumulus. These results support the hypothesis that the onset of significant precipitation is determined by the number of nucleated cloud drops and the height (H) above cloud base within the cloud that is required for cloud drops to reach re of 14 um. In turn, this can explain the conditions for initiation of significant drizzle and opening of closed cells providing the basis for a simple parameterization for GCMs that unifies the representation of both precipitating and non-precipitating clouds as well as the transition between them. Furthermore, satellite global observations of cloud depth (from base to top), and cloud top re can be used to derive and validate this parameterization.

Rosenfeld, Daniel; Wang, Hailong; Rasch, Philip J.

2012-07-04T23:59:59.000Z

232

Acoustic Inspection and Analysis of Liquids in Sealed Containers  

SciTech Connect (OSTI)

This article describes the Acoustic Inspection Device (AID) developed by PNNL which uses acoustic to determine the contents and fill level of sealed containers. AID is a power drill shaped battery operated device fitted with a transducer that sends an ultrasonic pusle through a container of liquid and measure the return echo. The device compares the echo velocity and attnuation and compares that data to a materials database in an Palm Pilot vlecored to the top of the device to give the operator a text identification of the substance with 5 seconds. The device is sensitive enough to distinguish coke from diet coke and and can distinguish subtances at a variety of temperatures ranging from below freezing to over 100degreesF. PNNL won an R&D 100 award for the technology in 2003.

Diaz, Aaron A.

2003-12-01T23:59:59.000Z

233

Quantum corrections to nonlinear ion acoustic wave with Landau damping  

SciTech Connect (OSTI)

Quantum corrections to nonlinear ion acoustic wave with Landau damping have been computed using Wigner equation approach. The dynamical equation governing the time development of nonlinear ion acoustic wave with semiclassical quantum corrections is shown to have the form of higher KdV equation which has higher order nonlinear terms coming from quantum corrections, with the usual classical and quantum corrected Landau damping integral terms. The conservation of total number of ions is shown from the evolution equation. The decay rate of KdV solitary wave amplitude due to the presence of Landau damping terms has been calculated assuming the Landau damping parameter ?{sub 1}=?(m{sub e}/m{sub i}) to be of the same order of the quantum parameter Q=?{sup 2}/(24m{sup 2}c{sub s}{sup 2}L{sup 2}). The amplitude is shown to decay very slowly with time as determined by the quantum factor Q.

Mukherjee, Abhik; Janaki, M. S. [Saha Institute of Nuclear Physics, Calcutta (India); Bose, Anirban [Serampore College, West Bengal (India)

2014-07-15T23:59:59.000Z

234

Effect of cooler electrons on a compressive ion acoustic solitary wave in a warm ion plasma — Forbidden regions, double layers, and supersolitons  

SciTech Connect (OSTI)

It is observed that the presence of a minority component of cooler electrons in a three component plasma plays a deterministic role in the evolution of solitary waves, double layers, or the newly discovered structures called supersolitons. The inclusion of the cooler component of electrons in a single electron plasma produces sharp increase in nonlinearity in spite of a decrease in the overall energy of the system. The effect maximizes at certain critical value of the number density of the cooler component (typically 15%–20%) giving rise to a hump in the amplitude variation profile. For larger amplitudes, the hump leads to a forbidden region in the ambient cooler electron concentration which dissociates the overall existence domain of solitary wave solutions in two distinct parameter regime. It is observed that an inclusion of the cooler component of electrons as low as < 1% affects the plasma system significantly resulting in compressive double layers. The solution is further affected by the cold to hot electron temperature ratio. In an adequately hotter bulk plasma (i.e., moderately low cold to hot electron temperature ratio), the parameter domain of compressive double layers is bounded by a sharp discontinuity in the corresponding amplitude variation profile which may lead to supersolitons.

Ghosh, S. S., E-mail: sukti@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai 410218 (India); Sekar Iyengar, A. N. [Plasma Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India)

2014-08-15T23:59:59.000Z

235

Method for chemically analyzing a solution by acoustic means  

DOE Patents [OSTI]

A method and apparatus are disclosed for determining a type of solution and the concentration of that solution by acoustic means. Generally stated, the method consists of: immersing a sound focusing transducer within a first liquid filled container; locating a separately contained specimen solution at a sound focal point within the first container; locating a sound probe adjacent to the specimen, generating a variable intensity sound signal from the transducer; measuring fundamental and multiple harmonic sound signal amplitudes; and then comparing a plot of a specimen sound response with a known solution sound response, thereby determining the solution type and concentration. 10 figs.

Beller, L.S.

1997-04-22T23:59:59.000Z

236

Method for chemically analyzing a solution by acoustic means  

DOE Patents [OSTI]

A method and apparatus for determining a type of solution and the concention of that solution by acoustic means. Generally stated, the method consists of: immersing a sound focusing transducer within a first liquid filled container; locating a separately contained specimen solution at a sound focal point within the first container; locating a sound probe adjacent to the specimen, generating a variable intensity sound signal from the transducer; measuring fundamental and multiple harmonic sound signal amplitudes; and then comparing a plot of a specimen sound response with a known solution sound response, thereby determining the solution type and concentration.

Beller, Laurence S. (Idaho Falls, ID)

1997-01-01T23:59:59.000Z

237

Adiabatic trapping in coupled kinetic Alfven-acoustic waves  

SciTech Connect (OSTI)

In the present work, we have discussed the effects of adiabatic trapping of electrons on obliquely propagating Alfven waves in a low {beta} plasma. Using the two potential theory and employing the Sagdeev potential approach, we have investigated the existence of arbitrary amplitude coupled kinetic Alfven-acoustic solitary waves in both the sub and super Alfvenic cases. The results obtained have been analyzed and presented graphically and can be applied to regions of space where the low {beta} assumption holds true.

Shah, H. A.; Ali, Z. [Department of Physics, G.C. University, 54000 Lahore (Pakistan); Masood, W. [COMSATS, Institute of Information Technology, Park Road, Chak Shahzad, Islamabad 44000 (Pakistan); National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Theoretical Plasma Physics Division, P. O. Nilore, Islamabad (Pakistan)

2013-03-15T23:59:59.000Z

238

Determination of effective brain connectivity from functional connectivity using propagator-based interferometry and neural field theory with application to the corticothalamic system  

Science Journals Connector (OSTI)

It is shown how to compute both direct and total effective connection matrices (deCMs and teCMs), which embody the strengths of neural connections between regions, from correlation-based functional CMs using propagator-based interferometry, a method that stems from geophysics and acoustics, coupled with the recent identification of deCMs and teCMs with bare and dressed propagators, respectively. The approach incorporates excitatory and inhibitory connections, multiple structures and populations, and measurement effects. The propagator is found for a generalized scalar wave equation derived from neural field theory, and expressed in terms of neural activity correlations and covariances, and wave damping rates. It is then related to correlation matrices that are commonly used to express functional and effective connectivities in the brain. The results are illustrated in analytically tractable test cases.

P. A. Robinson

2014-10-15T23:59:59.000Z

239

Processing dipole acoustic logging data to image fracture network in shale gas reservoirs  

Science Journals Connector (OSTI)

A recent advance in borehole remote acoustic reflection imaging is the utilization of a dipole acoustic system in a borehole to emit and receive elastic waves to and from a remote geologic reflector in formation. An important application of this new technique is the delineation of fracture network in shale gas reservoirs as interest and activities in shale gas exploration increase in China. We develop a data processing procedure and implement it to handle routine processing of dipole acoustic logging data. The procedure takes into account the characteristics of the dipole data such as frequency dispersion attenuation recording length and dipole source orientation etc. to obtain an image of reflectors within 20~30 meters around the borehole. We have applied the technique to process dipole acoustic data from several wells drilled into gas reservoirs in China. The obtained images clearly identify major fracture network in the gas producing intervals of the reservoir demonstrating the effectiveness of the imaging technique.

Zhuang Chunxi; Su Yuanda; Tang Xiaoming

2012-01-01T23:59:59.000Z

240

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

242

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

243

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

244

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.

245

Method and system for generating a beam of acoustic energy from a borehole, and applications thereof  

DOE Patents [OSTI]

A compact array of transducers is employed as a downhole instrument for acoustic investigation of the surrounding rock formation. The array is operable to generate simultaneously a first acoustic beam signal at a first frequency and a second acoustic beam signal at a second frequency different than the first frequency. These two signals can be oriented through an azimuthal rotation of the array and an inclination rotation using control of the relative phases of the signals from the transmitter elements or electromechanical linkage. Due to the non-linearity of the formation, the first and the second acoustic beam signal mix into the rock formation where they combine into a collimated third signal that propagates in the formation along the same direction than the first and second signals and has a frequency equal to the difference of the first and the second acoustic signals. The third signal is received either within the same borehole, after reflection, or another borehole, after transmission, and analyzed to determine information about rock formation. Recording of the third signal generated along several azimuthal and inclination directions also provides 3D images of the formation, information about 3D distribution of rock formation and fluid properties and an indication of the dynamic acoustic non-linearity of the formation.

Johnson Paul A. (Santa Fe, NM); Ten Cate, James A. (Los Alamos, NM); Guyer, Robert (Reno, NV); Le Bas, Pierre-Yves (Los Alamos, NM); Vu, Cung (Houston, TX); Nihei, Kurt (Oakland, CA); Schmitt, Denis P. (Katy, TX); Skelt, Christopher (Houston, TX)

2012-02-14T23:59:59.000Z

246

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

247

Phononic-Crystal-Based Acoustic Sieve for Tunable Manipulations of Particles by a Highly Localized Radiation Force  

Science Journals Connector (OSTI)

The ability to manipulate microscale and nanoscale particles is highly desirable for various applications ranging from targeting drug delivery to additive manufacturing. Here we report an acoustic sieve that is capable of aligning, trapping, sorting, and transferring a large number of particles according to their size or mass density, all in a tunable manner. The concept is based on the highly localized periodic radiation force induced by the resonance transmission of an acoustic wave across a phononic crystal plate, a phenomenon analogous to the surface-phonon-enhanced optical force, yet the physical concept has not been explored in acoustics. The acoustic sieve demonstrates the effective manipulation of massive particles using an artificially engineered acoustic field by a phononic crystal, and it has potential application for a wide range of applications.

Fei Li; Feiyan Cai; Zhengyou Liu; Long Meng; Ming Qian; Chen Wang; Qian Cheng; Menglu Qian; Xin Liu; Junru Wu; Jiangyu Li; Hairong Zheng

2014-06-11T23:59:59.000Z

248

Acoustic radiation by charged nuclear particles in liquids  

Science Journals Connector (OSTI)

An analysis of the propagation of acoustic pulses produced by local heating of liquids due to ionization by charged particles is presented. It is shown that the wave equations with loss dominate the pulse shape after small distances and that due to the bipolar delta?function behavior of the individual pulses a net observed pulse is simply the time derivative of the received density of pulses from individual heating centers. Angular distributions signal to noise ratios and detectable volumes are discussed. One important result is that the effect of attenuation in the acoustic medium is to produce a power law rather than an exponential cutoff at large distances. For example in the thermal?noise?limited case the signal to noise ratio as defined herein only steepens by 1/2 power in fall off with distance due to attenuation.

John G. Learned

1978-01-01T23:59:59.000Z

249

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

250

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

251

Ion acoustic solitary waves and double layers in a plasma with two temperature electrons featuring Tsallis distribution  

SciTech Connect (OSTI)

The propagation properties of large amplitude ion acoustic solitary waves (IASWs) are studied in a plasma containing cold fluid ions and multi-temperature electrons (cool and hot electrons) with nonextensive distribution. Employing Sagdeev pseudopotential method, an energy balance equation has been derived and from the expression for Sagdeev potential function, ion acoustic solitary waves and double layers are investigated numerically. The Mach number (lower and upper limits) for the existence of solitary structures is determined. Positive as well as negative polarity solitary structures are observed. Further, conditions for the existence of ion acoustic double layers (IADLs) are also determined numerically in the form of the critical values of q{sub c}, f and the Mach number (M). It is observed that the nonextensivity of electrons (via q{sub c,h}), concentration of electrons (via f) and temperature ratio of cold to hot electrons (via ?) significantly influence the characteristics of ion acoustic solitary waves as well as double layers.

Shalini,, E-mail: shal.phy29@gmail.com; Saini, N. S., E-mail: nssaini@yahoo.com [Department of Physics, Guru Nanak Dev University, Amritsar-143005 (India)

2014-10-15T23:59:59.000Z

252

MODEL FOR DETERMINING THE EFFECTIVE THERMAL CONDUCTIVITY OF PARTICLE BEDS WITH HIGH SOLID-TO-GAS THERMAL  

E-Print Network [OSTI]

MODEL FOR DETERMINING THE EFFECTIVE THERMAL CONDUCTIVITY OF PARTICLE BEDS WITH HIGH SOLID-TO-GAS- to-gas conductivity ratio (such as Be and He). The model has the capability of accounting with high solid-to-gas thermal conductivity ratios. This paper summarizes this modeling effort. Model

Abdou, Mohamed

253

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

E-Print Network [OSTI]

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

Hake, Mariah I. (Mariah Inez)

2014-01-01T23:59:59.000Z

254

CX-002299: Categorical Exclusion Determination | Department of Energy  

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

2299: Categorical Exclusion Determination 2299: Categorical Exclusion Determination CX-002299: Categorical Exclusion Determination Passive Acoustic Detection of Wind Turbine In-Flow Conditions for Active Control and Optimization CX(s) Applied: B3.1, B3.6, A9 Date: 05/13/2010 Location(s): Mississippi Office(s): Energy Efficiency and Renewable Energy, Golden Field Office The University of Mississippi proposes to use federal funds to study and analyze wind data to predict wind gusts accurately that have detrimental effects on wind turbine lifespan. This research is aimed at reducing operating costs, protecting the wind turbine structure, and lowering wind turbine generated noise. DOCUMENT(S) AVAILABLE FOR DOWNLOAD CX-002299.pdf More Documents & Publications CX-002276: Categorical Exclusion Determination

255

Determination of applied stresses in rails using the acoustoelastic effect of ultrasonic waves  

E-Print Network [OSTI]

temperature, aT is the ambient temperature, and ? is the stress. Fig. 1.2 shows this relationship. Thus, if the longitudinal stress in the rail is determined and the ambient temperature known, SFT can be determined using Eq. (1.2). Following... u V x ?? ??? ? ? ??? ???? ?? , (3.5) where xm denotes the direction in the coordinate system and um denotes the displacement in the xm - direction. Assuming a continuous integrand, Eq. (3.5) will be satisfied...

Gokhale, Shailesh Ashok

2009-05-15T23:59:59.000Z

256

Determination of applied stresses in rails using the acoustoelastic effect of ultrasonic waves  

E-Print Network [OSTI]

temperature, aT is the ambient temperature, and ? is the stress. Fig. 1.2 shows this relationship. Thus, if the longitudinal stress in the rail is determined and the ambient temperature known, SFT can be determined using Eq. (1.2). Following... u V x ?? ??? ? ? ??? ???? ?? , (3.5) where xm denotes the direction in the coordinate system and um denotes the displacement in the xm - direction. Assuming a continuous integrand, Eq. (3.5) will be satisfied...

Gokhale, Shailesh Ashok

2008-10-10T23:59:59.000Z

257

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.

258

Multiple-frequency acoustic wave devices for chemical sensing and materials characterization in both gas and liquid phase  

DOE Patents [OSTI]

A chemical or intrinsic physical property sensor is described comprising: (a) a substrate; (b) an interaction region of said substrate where the presence of a chemical or physical stimulus causes a detectable change in the velocity and/or an attenuation of an acoustic wave traversing said region; and (c) a plurality of paired input and output interdigitated electrodes patterned on the surface of said substrate where each of said paired electrodes has a distinct periodicity, where each of said paired electrodes is comprised of an input and an output electrode; (d) an input signal generation means for transmitting an input signal having a distinct frequency to a specified input interdigitated electrode of said plurality so that each input electrode receives a unique input signal, whereby said electrode responds to said input signal by generating an acoustic wave of a specified frequency, thus, said plurality responds by generating a plurality of acoustic waves of different frequencies; (e) an output signal receiving means for determining an acoustic wave velocity and an amplitude of said acoustic waves at several frequencies after said waves transverses said interaction region and comparing these values to an input acoustic wave velocity and an input acoustic wave amplitude to produce values for perturbations in acoustic wave velocities and for acoustic wave attenuation as a function of frequency, where said output receiving means is individually coupled to each of said output interdigitated electrode; (f) a computer means for analyzing a data stream comprising information from said output receiving means and from said input signal generation means to differentiate a specified response due to a perturbation from a subsequent specified response due to a subsequent perturbation to determine the chemical or intrinsic physical properties desired.

Martin, S.J.; Ricco, A.J.

1993-08-10T23:59:59.000Z

259

Determination of Knowledge and Misconceptions of Pre-service Elementary Science Teachers about the Greenhouse Effect by Drawing  

Science Journals Connector (OSTI)

Abstract In this study, we aimed to determine pre-service elementary science teachers’ knowledge about the greenhouse effect by drawing to determine the misconceptions they have and to classify their level of knowledge. This study was carried out with 71 pre- service teachers studying for their third year at the Science Education Department in the Faculty of Education at a state university in Turkey. In the study, the pre-service teachers were asked to put forward their knowledge about the greenhouse effect by drawing and writing. The obtained drawings and written statements were evaluated with descriptive analysis of the answers given to the questions carried out by dividing them into groups based on six different levels, as used by Kara (2007). According to the results of the research, it has been observed that pre-service teachers have inadequate knowledge and misconceptions about the greenhouse effect.

Dilek Çelikler; Zeynep Aksan

2014-01-01T23:59:59.000Z

260

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

262

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

263

The effect of the proposed use of any credible evidence to determine compliance on utilities  

SciTech Connect (OSTI)

Reference test methods are the only means currently available to determine compliance with air quality emission standards. All parties involved acknowledge that this excludes the use of data from continuous monitoring systems (CMS) to determine compliance with many air quality regulations. However, the United States Environmental Protection Agency (USEPA) is proposing to finalize portions of the 1993 Enhanced Monitoring (EM) rule that would allow the use of any credible evidence (ACE) to determine compliance with air emission limitations (including CMS data). This position has been taken by the USEPA in spite of strenuous objections that the 1993 rule has been subsequently replaced with the more relevant 1995 Compliance Assurance Monitoring (CAM) rule. The use of ACE to determine compliance will have a significant impact on utilities due to the large number and type of air quality regulations that affect utilities; specifically, subparts D and Da of the New Source Performance Standards (NSPS) and regulations implementing Title IV (the Acid Rain Program) of the Clean Air Act (CAA) which require the use of CMS. These monitoring systems produce large amounts of emission data that are submitted to the USEPA, State, and/or local regulators agencies and, once submitted, become public record. Any interested party, either the regulator or the public, can use the data to show non-compliance with applicable standards; therefore, the use of ACE to determine compliance will substantially increase a utility`s liability. This paper discusses: (1) the regulatory history behind what data can be considered in determining compliance, (2) the potential implications of the ACE rule on utilities, and (3) the potential implications of the ACE rule on the development of a compliance demonstration plan for the Title V operating permit.

Lowery, K.P. [Trinity Consultants Inc., Overland Park, KS (United States); Facca, G.L. [IES Utilities Inc., Cedar Rapids, IA (United States)

1997-12-31T23:59:59.000Z

264

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

265

Signal Processing in Acoustics: Science or Science Fiction?  

Science Journals Connector (OSTI)

Signal processing in acoustics is based on one fundamental concept—extracting critical information from noisy uncertain measurement data. Acoustical processing problems can lead to some complex and intricate paradigms to perform this extraction especially from noisy sometimes inadequate measurements. Whether the data are created using a seismic geophone sensor from a monitoring network or an array of hydrophone transducers located on the hull of an ocean?going vessel the basic processing problem remains the same—extract the useful information. Techniques in signal processing (e.g. filtering Fourier transforms time?frequency and wavelet transforms) are effective; however as the underlying acoustical process generating the measurements becomes more complex the resulting processor may require more and more information about the process phenomenology to extract the desired information. The challenge is to formulate a meaningful strategy that is aimed at performing the processing required even in the face of these high uncertainties. In this article we briefly discuss this underlying signal processing philosophy from a “bottoms?up” perspective enabling the problem to dictate the solution rather than visa?versa. Once accomplished we ask ourselves the final and telling question “Did it work or are we kidding ourselves?” Are the results science or are they science fiction?

James V. Candy

2008-01-01T23:59:59.000Z

266

Further applications of time?frequency methods in acoustics  

Science Journals Connector (OSTI)

Time?frequency (t?f) methods have been repeatedly established as effective tools to successfully analyze a variety of signatures from many types of sources or scatterers. Many such signatures have been acoustic in nature and we have studied these most extensively in the past. We have presented several of these examples before [viz. G. C. Gaunaurd and H. C. Strifors J. Acoust. Soc. Am. 104 1746 136th ASA Mtg. (1998)]. Here we will cover acoustical applications that we have analyzed but which were not adequately covered in 1998. We will also outline additional ones—more extensively discussed in Appl. Mech. Rev. 50 131–149 (1997)—and a recent radar application [i.e. ibid. IEEE Trans. Antennas Propag. 46 1252–1262 (1998)]. In this case the present t?f processing was shown capable of successfully identifying an air target that had been covered with a dielectric RCS?reducing layer. We believe that this general approach jointly with the way we have used it to physically interpret broadband sonar/radar signatures can lead to straightforward implementations for many practical target?classification problems associated with many types of sensors. [Work partially supported by the ILIR Program of the authors’ Institutions and the ONR.

G. C. Gaunaurd; H. C. Strifors

1999-01-01T23:59:59.000Z

267

Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter  

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. As part of the transmitter downsizing effort some of the design parameters of the lead zirconate titanate (PZT) ceramic tube transducer in the transmitter were studied, including the type of PZT, the backing material, the necessary drive voltage, the transmitting bandwidth and the length of the transducer. It was found that, to satisfy the 156-dB source level requirement of JSATS, a square wave with a 10-volt amplitude is required to drive 'soft' PZT transducers. PZT-5H demonstrated the best source level performance. For Navy types I and II, 16 volts or 18 volts were needed. Ethylene-propylene-diene monomer (EPDM) closed-cell foam was found to be the backing material providing the highest source level. The effect of tube length on the source level is also demonstrated in this paper, providing quantitative information for downsizing of small piezoelectric transmitters.

Li, Huidong; Deng, Zhiqun; Yuan, Yong; Carlson, Thomas J.

2012-07-02T23:59:59.000Z

268

Acoustic-wave sensor apparatus for analyzing a petroleum-based composition and sensing solidification of constituents therein  

DOE Patents [OSTI]

An acoustic-wave sensor apparatus and method are disclosed. The apparatus for analyzing a normally liquid petroleum-based composition includes at least one acoustic-wave device in contact with the petroleum-based composition for sensing or detecting the presence of constituents (e.g. paraffins or petroleum waxes) therein which solidify upon cooling of the petroleum-based composition below a cloud-point temperature. The acoustic-wave device can be a thickness-shear-mode device (also termed a quartz crystal microbalance), a surface-acoustic-wave device, an acoustic-plate-mode device or a flexural plate-wave device. Embodiments of the present invention can be used for measuring a cloud point, a pour point and/or a freeze point of the petroleum-based composition, and for determining a temperature characteristic of each point. Furthermore, measurements with the acoustic-wave sensor apparatus can be made off-line by using a sample having a particular petroleum-based composition; or in-situ with the petroleum-based composition contained within a pipeline or storage tank. The acoustic-wave sensor apparatus has uses in many different petroleum technology areas, including the recovery, transport, storage, refining and use of petroleum and petroleum-based products. 7 figs.

Spates, J.J.; Martin, S.J.; Mansure, A.J.

1997-08-26T23:59:59.000Z

269

Acoustic-wave sensor apparatus for analyzing a petroleum-based composition and sensing solidification of constituents therein  

DOE Patents [OSTI]

An acoustic-wave sensor apparatus and method. The apparatus for analyzing a normally liquid petroleum-based composition includes at least one acoustic-wave device in contact with the petroleum-based composition for sensing or detecting the presence of constituents (e.g. paraffins or petroleum waxes) therein which solidify upon cooling of the petroleum-based composition below a cloud-point temperature. The acoustic-wave device can be a thickness-shear-mode device (also termed a quartz crystal mircrobalance), a surface-acoustic-wave device, an acoustic-plate-mode device or a flexural plate-wave device. Embodiments of the present invention can be used for measuring a cloud point, a pour point and/or a freeze point of the petroleum-based composition, and for determining a temperature characteristic of each point. Furthermore, measurements with the acoustic-wave sensor apparatus can be made off-line by using a sample having a particular petroleum-based composition; or in-situ with the petroleum-based composition contained within a pipeline or storage tank. The acoustic-wave sensor apparatus has uses in many different petroleum technology areas, including the recover transport, storage, refining and use of petroleum and petroleum-based products.

Spates, James J. (Albuquerque, NM); Martin, Stephen J. (Albuquerque, NM); Mansure, Arthur J. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

270

Determining the effect of LEF-12 on late viral gene expression  

E-Print Network [OSTI]

and improve upon the baculovirus expression system. The most recently identified LEF, LEF-12, was found to be necessary for transient late gene expression but its function has yet to be determined (5). We over-expressed and purified the LEF-12 protein...

Peterson, April Lynn

2013-02-22T23:59:59.000Z

271

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...

272

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...

273

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......

274

Acoustic emission monitoring of steam turbines. Final report  

SciTech Connect (OSTI)

Experience over several years with on-line monitoring of steam turbines, supported by relevant laboratory studies, has led to a clearer understanding of the conditions under which acoustic emission (AE) due to turbine shaft cracking can be detected. To overcome problems associated with the noisy environment, efforts have been directed at improving the AE signal discrimination capabilities of the monitoring electronics. These efforts have been guided by extensive measurements of the amplitude, frequency and time dependence of normal turbine noises in a variety of operating conditions. Similar measurements have been made in the laboratory to determine the characteristics of AE due to crack growth in rotor steels with several loading conditions and temperatures. Along with determinations of the attenuation and wave propagation characteristics of simulated AE in the rotor shafts, these measurements have permitted estimates of the detectability of AE due to crack growth under various conditions, should it occur. An essential part of the proposed monitoring will be determining the source locations and characteristics of ''normal'' operating noise and developing time histories of these sources so that when ''abnormal'' crack growth AE occurs, it will be recognized. The time histories of the ''normal'' operating noises may also reveal other potentially damaging conditions such as lubricating oil contamination, bearing wear, out-of-balance condition, loose turbine disks, blade cracking or rubbing and impingement of exfoliation particles or water droplets, each of which is known or expected to have a characteristic acoustic signature. 17 refs., 23 figs., 8 tabs.

Randall, R.L.; Hong, C.; Graham, L.J.

1986-02-01T23:59:59.000Z

275

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

276

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

277

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

278

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

279

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.

280

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

Spatial coherence effect on layer thickness determination in narrowband full-field optical coherence tomography  

SciTech Connect (OSTI)

Longitudinal spatial coherence (LSC) is determined by the spatial frequency content of an optical beam. The use of lenses with a high numerical aperture (NA) in full-field optical coherence tomography and a narrowband light source makes the LSC length much shorter than the temporal coherence length, hence suggesting that high-resolution 3D images of biological and multilayered samples can be obtained based on the low LSC. A simplified model is derived, supported by experimental results, which describes the expected interference output signal of multilayered samples when high-NA lenses are used together with a narrowband light source. An expression for the correction factor for the layer thickness determination is found valid for high-NA objectives. Additionally, the method was applied to a strongly scattering layer, demonstrating the potential of this method for high-resolution imaging of scattering media.

Safrani, Avner; Abdulhalim, Ibrahim

2011-06-20T23:59:59.000Z

282

Determination of the fuel effect of a pumped-storage station  

Science Journals Connector (OSTI)

The fuel effect of pumped-storage stations in real power systems varies in wide limits depending on the ... · yr when their share in the power system is of the order of 6–7%...

A. N. Zeiliger; V. S. Sharygin; V. N. Ivanchenkov

1981-02-01T23:59:59.000Z

283

The effects of radiation on spermatogenesis in the albino rat as determined by semen analysis  

E-Print Network [OSTI]

rate all could be significant factors. Total body X-irradiation (470 r) in rats produced minimal alterations in the testes, namely depletion of spermatogonia (Gunn, et al. , 1960). 17 18 The effect of whole-body radiation on fertility of male rats...) Figure 22. Effect of Radiation on Weight Change (Chronic). no irradiation, demonstrated steady weekly increases through the investigation period. The average body weight of these animals at the initiation of this study was approximately 510 grams...

Lawson, Rommon Loy

1964-01-01T23:59:59.000Z

284

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

285

A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization  

SciTech Connect (OSTI)

The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate magnetic resonance (MR) techniques and acoustic measurements to improve predictability of the pay zone in two hydrocarbon reservoirs. This was accomplished by extracting the fluid property parameters using MR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurements were compared with petrographic analysis results to determine the relative roles of petrographic elements such as porosity type, mineralogy, texture, and distribution of clay and cement in creating permeability heterogeneity.

Parra, J.O.

2001-01-26T23:59:59.000Z

286

An analysis of injuries to determine the effect of wage incentives on safety performance of production workers  

E-Print Network [OSTI]

, and othem. Future research must be designed to isolate and/or eliminate these variables in order to more closely determine the effects of in-' centives on production workers. ACKHOWIi53X2%5TS A word. of appreciation must be experssed to certain people... of Literature. 1 1 2 4 II. METHODOLOGY . ~ ~ . ~ ~ ~ III. PLANTS SELECTED FOR STUDY IV. PRESEHTATIOITT OF DATA. 12 17 Injuries Pez Length of Time Employed Classifi ABCO Manufacturing Company. A. Brendt Manufacturing Company Kroehler Nanufacturing...

Brock, Kennith Douglas

2012-06-07T23:59:59.000Z

287

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

288

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

289

Acoustic Emission Source Location in Unidirectional Carbon-Fibre-Reinforced Plastic Plates Using Virtually Trained Artificial Neural Networks  

SciTech Connect (OSTI)

Acoustic emission source location in a unidirectional carbon-fibre-reinforced plastic plate was attempted employing Artificial Neural Network (ANN) technology. The acoustic emission events were produced by a lead break, and the response wave received by piezoelectric sensors, type VS150-M resonant at 150 kHz. The waves were detected by a Vallen AMSY4 eight-channel instrumentation. The time of arrival, determined through the conventional threshold crossing technique, was used to measure the dependence of wave velocity on fibre orientation. A simple empirical formula, relying on classical lamination and suggested by wave propagation theory, was able to accurately model the experimental trend. Based on the formula, virtual training and testing data sets were generated for the case of a plate monitored by three transducers, and adopted to select two potentially effective ANN architectures. For final validation, experimental tests were carried out, positioning the source at predetermined points evenly distributed within the plate area. A very satisfactory correlation was found between the actual source locations and the ANN predictions.

Caprino, G.; Lopresto, V.; Leone, C.; Papa, I. [Department of Materials and Production Engineering, University of Naples 'Federico II', Piazzale Tecchio, 80, 80125, Naples (Italy)

2010-06-02T23:59:59.000Z

290

Acoustic method for measurements of the coolant boiling on heat generating surfaces  

Science Journals Connector (OSTI)

Acoustic method for determining the period of different duties of the coolant boiling is presented. The foundation of this method is the damping phenomenon of ultrasonic waves travelling through the boundary between different media (steam–liquid) differing widely in their acoustic properties. The experimental setup and the results of the investigations into the period of water film boiling on spherical samples are also presented. The emphasis is on aluminum and copper samples differing in their diameter (4 5 and 8 mm) for temperature interval ?t=180–690°C at atmospheric pressure and different surrounding water temperatures (?t=15–75°C). By analyzing the result it is illustrated that the precision of the method is well above that of thermocouples. It is demonstrated that the measurements using this acoustic method excludes the errors typical of traditional methods. ?

2001-01-01T23:59:59.000Z

291

Constraints on dark energy from baryon acoustic peak and galaxy cluster gas mass measurements  

E-Print Network [OSTI]

We use baryon acoustic peak measurements by Eisenstein et al. (2005) and Percival et al. (2007a) and galaxy cluster gas mass fraction measurements of Allen et al. (2008) to constrain parameters of three different dark energy models. For time-independent dark energy, the Percival et al. (2007a) constraints, which make use of the WMAP measurement of the apparent acoustic horizon angle, most effectively constrain a cosmological parameter close to spatial curvature and favor a close to spatially flat model. In a spatially-flat model the Percival et al. (2007a) data less effectively constrain time-varying dark energy. The joint baryon acoustic peak and galaxy cluster gas mass constraints are consistent with but tighter than those derived from other data. A time-independent cosmological constant in a spatially-flat model provides a good fit to the joint data, but slowly-evolving dark energy can not yet be ruled out.

Lado Samushia; Bharat Ratra

2008-06-17T23:59:59.000Z

292

Categorical Exclusion Determinations: Office of Energy Efficiency and  

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

25, 2011 25, 2011 CX-006029: Categorical Exclusion Determination Acoustic Effects of Hydrokinetic Tidal Turbines CX(s) Applied: B3.3, B3.6 Date: 05/25/2011 Location(s): Snohomish County, Washington Office(s): Energy Efficiency and Renewable Energy, Golden Field Office May 25, 2011 CX-006015: Categorical Exclusion Determination Energy Efficiency and Conservation Block Grant Program - Iowa-City-Cedar Rapids CX(s) Applied: A1, A9, A11, B1.32, B2.5, B3.6, B5.1 Date: 05/25/2011 Location(s): Cedar Rapids, Iowa Office(s): Energy Efficiency and Renewable Energy May 25, 2011 CX-006006: Categorical Exclusion Determination Deployment of Innovative Energy Efficiency and Renewable Energy - Agriculture CX(s) Applied: B5.1 Date: 05/25/2011 Location(s): The Dalles, Oregon Office(s): Energy Efficiency and Renewable Energy, Golden Field Office

293

Categorical Exclusion Determinations: Office of Energy Efficiency and  

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

5, 2011 5, 2011 CX-006240: Categorical Exclusion Determination Acoustic Effects of Hydrokinetic Tidal Turbines CX(s) Applied: B3.1, B3.3 Date: 07/15/2011 Location(s): Washington Office(s): Energy Efficiency and Renewable Energy, Golden Field Office July 15, 2011 CX-006238: Categorical Exclusion Determination Development of Post-Installation Monitoring Capabilities CX(s) Applied: A9, B3.1, B3.3 Date: 07/15/2011 Location(s): Washington Office(s): Energy Efficiency and Renewable Energy, Golden Field Office July 15, 2011 CX-006228: Categorical Exclusion Determination State Energy Program American Recovery and Reinvestment Act - Deployment of Innovative Energy Efficiency and Renewable Energy - Agriculture - Dufur and Hanna-Cantrell CX(s) Applied: B5.1 Date: 07/15/2011 Location(s): Dufur, Oregon

294

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

295

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

296

Determining the effects of surface elasticity and surface stress by measuring the shifts of resonant frequencies  

Science Journals Connector (OSTI)

...186105 ) 25 Huang, DW . 2008 Size-dependent response of ultra-thin films with surface effects. Int. J. Solids Struct...vibrations. New York, NY: Macmillan Publishing. 46 Ghatkesar, MK , V Barwich, T Braun, J Ramseyer, Ch Gerber, M Hegner, HP...

2013-01-01T23:59:59.000Z

297

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

298

Ion acoustic solitons/double layers in two-ion plasma revisited  

SciTech Connect (OSTI)

Ion acoustic solitons and double layers are studied in a collisionless plasma consisting of cold heavier ion species, a warm lighter ion species, and hot electrons having Boltzmann distributions by Sagdeev pseudo-potential technique. In contrast to the previous results, no double layers and super-solitons are found when both the heavy and lighter ion species are treated as cold. Only the positive potential solitons are found in this case. When the thermal effects of the lighter ion species are included, in addition to the usual ion-acoustic solitons occurring at M?>?1 (where the Mach number, M, is defined as the ratio of the speed of the solitary wave and the ion-acoustic speed considering temperature of hot electrons and mass of the heavier ion species), slow ion-acoustic solitons/double layers are found to occur at low Mach number (M?acoustic mode is actually a new ion-ion hybrid acoustic mode which disappears when the normalized number density of lighter ion species tends to 1 (i.e., no heavier species). An interesting property of the new slow ion-acoustic mode is that at low number density of the lighter ion species, only negative potential solitons/double layers are found whereas for increasing densities there is a transition first to positive solitons/double layers, and then only positive solitons. The model can be easily applicable to the dusty plasmas having positively charged dust grains by replacing the heavier ion species by the dust mass and doing a simple normalization to take account of the dust charge.

Lakhina, G. S., E-mail: gslakhina@gmail.com; Singh, S. V., E-mail: satyavir@iigs.iigm.res.in; Kakad, A. P., E-mail: amar@iigs.iigm.res.in [Indian Institute of Geomagnetism, New Panvel (W), Navi Mumbai 410218 (India)

2014-06-15T23:59:59.000Z

299

Non-Lte Effects on be and B Abundance Determinations in Cool Stars  

E-Print Network [OSTI]

We discuss the nature of non-LTE effects affecting abundance analysis of cool stars. The departures from LTE of importance for the B I lines in solar-type stars are described and some new results are presented. Boron abundances derived under the LTE assumption have significant systematic errors, especially for metal-poor stars. For beryllium, current results suggest that departures from LTE will not affect abundance analysis significantly.

Dan Kiselman; Mats Carlsson

1994-09-26T23:59:59.000Z

300

Method of and apparatus for determining deposition-point temperature  

DOE Patents [OSTI]

Acoustic-wave sensor apparatus and method for analyzing a normally liquid petroleum-based composition for monitoring deposition-point temperature. The apparatus includes at least one acoustic-wave device such as SAW, QCM, FPM, TSM or APM type devices in contact with the petroleum-based composition for sensing or detecting the surface temperature at which deposition occurs and/or rate of deposition as a function of temperature by sensing an accompanying change in frequency, phase shift, damping voltage or damping current of an electrical oscillator to a known calibrated condition. The acoustic wave device is actively cooled to monitor the deposition of constituents such as paraffins by determining the point at which solids from the liquid composition begin to form on the acoustic wave device. The acoustic wave device can be heated to melt or boil off the deposits to reset the monitor and the process can be repeated.

Mansure, Arthur J. (Albuquerque, NM); Spates, James J. (Albuquerque, NM); Martin, Stephen J. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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 of and apparatus for determining deposition-point temperature  

DOE Patents [OSTI]

Acoustic-wave sensor apparatus and method are disclosed for analyzing a normally liquid petroleum-based composition for monitoring deposition-point temperature. The apparatus includes at least one acoustic-wave device such as SAW, QCM, FPM, TSM or APM type devices in contact with the petroleum-based composition for sensing or detecting the surface temperature at which deposition occurs and/or rate of deposition as a function of temperature by sensing an accompanying change in frequency, phase shift, damping voltage or damping current of an electrical oscillator to a known calibrated condition. The acoustic wave device is actively cooled to monitor the deposition of constituents such as paraffins by determining the point at which solids from the liquid composition begin to form on the acoustic wave device. The acoustic wave device can be heated to melt or boil off the deposits to reset the monitor and the process can be repeated. 5 figs.

Mansure, A.J.; Spates, J.J.; Martin, S.J.

1998-10-27T23:59:59.000Z

302

Landau Damping of Geodesic Acoustic Mode in Toroidally Rotating Tokamaks  

E-Print Network [OSTI]

Geodesic acoustic mode (GAM) is analyzed by using gyro-kinetic equations applicable to low-frequency microinstabilities in a rotating axisymmetric plasma. Dispersion relation of GAM in the presence of arbitrary Mach number is analytically dervied. Toroidal rotation plays the same effects on the GAM regardless of the orientation of equilibrium flow. It is shown that the toroidal Mach number increases the GAM frequency and dramatically decreases the Landau damping rate. Classical gyro-kinetic equation is examined to be not suitable for describing the GAM in a torodially rotating tokamak plasma even for very small Mach number.

Ren, Haijun

2015-01-01T23:59:59.000Z

303

Oblique ion acoustic shock waves in a magnetized plasma  

SciTech Connect (OSTI)

Ion acoustic (IA) shock waves are studied in a magnetized plasma consisting of a cold viscous ion fluid and Maxwellian electrons. The Korteweg–de Vries–Burgers equation is derived by using the reductive perturbation method. It is shown that the combined effects of external magnetic field and obliqueness significantly modify the basic properties (viz., amplitude, width, speed, etc.) of the IA shock waves. It is observed that the ion-viscosity is a source of dissipation, and is responsible for the formation of IA shock structures. The implications of our results in some space and laboratory plasma situations are discussed.

Shahmansouri, M. [Department of Physics, Faculty of Science, Arak University, Arak 38156-8 8349 (Iran, Islamic Republic of)] [Department of Physics, Faculty of Science, Arak University, Arak 38156-8 8349 (Iran, Islamic Republic of); Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)] [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)

2013-08-15T23:59:59.000Z

304

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 ...

305

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...

306

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 ...

307

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...

308

Black box measurements ? Using a family of electrical circuits as a tool for self-guided learning in acoustical engineering  

Science Journals Connector (OSTI)

A partnership between Brazil's first undergraduate program in Acoustical Engineering and the Institute of Technical Acoustics of RWTH Aachen University yielded a didactic project that uses the engineering software MATLAB with the ITA-Toolbox to teach acoustic measurements. Simple electrical circuits are used to mimic typical behavior of acoustical systems. This low-cost solution has proven to be didactically very effective since it helps students to identify themselves with the measurement tasks. Two hardware solutions were developed-a simple oscillator circuit integrated into connectors of audio cables and a desktop box containing seven different transfer characteristics ranging from ideal linear and time-invariant to nonlinear and time-varying behavior. Undergraduate students of Acoustical Engineering used both devices in classroom experiments for self-guided learning by comparing their results to published results. Students were able to learn the fundamental concepts of acoustical measurements and to handle measurement tasks. Besides the practical experiences and the learning effect the students were also encouraged to step into the open source routines of the software understand the signal processing steps adapt routines and even write their own ones e.g. a GUI that provides effective control of the measurement via touch-screens.

Bernardo H. Murta; Jessica Lins; Sergio Aguirre; Stephan Paul; Eric Brandao; Pascal Dietrich

2013-01-01T23:59:59.000Z

309

Black box measurements – Using a family of electrical circuits as a tool for self-guided learning in acoustical engineering  

Science Journals Connector (OSTI)

A partnership between Brazil’s first undergraduate program in Acoustical Engineering and the Institute of Technical Acoustics of RWTH Aachen University yielded in a didactic project that uses the engineering software MATLAB with the ITA-Toolbox to teach acoustic measurements. Simple electrical circuits are used to mimic typical behavior of acoustical systems. This low-cost solution has proven to be didactically very effective since it helps students to identify themselves with the measurement tasks. Two hardware solutions were developed-a simple oscillator circuit integrated into connectors of audio cables and a desktop box containing seven different transfer characteristics ranging from ideal linear and time-invariant to nonlinear and time-varying behavior. Undergraduate students of Acoustical Engineering used both devices in classroom experiments for self-guided learning by comparing their results to published results. Students were able to learn the fundamental concepts of acoustical measurements and to handle measurement tasks. Besides the practical experiences and the learning effect the students were also encouraged to step into the open source routines of the software understand the signal processing steps adapt routines and even write their own ones e.g. a GUI that provides effective control of the measurement via touch-screens.

Bernardo H. Murta; Sergio Aguirre; Stephan Paul

2013-01-01T23:59:59.000Z

310

Acoustically Mounted Microcrystals Yield High-Resolution X-ray Structures  

SciTech Connect (OSTI)

We demonstrate a general strategy for determining structures from showers of microcrystals. It uses acoustic droplet ejection to transfer 2.5 nL droplets from the surface of microcrystal slurries, through the air, onto mounting micromesh pins. Individual microcrystals are located by raster-scanning a several-micrometer X-ray beam across the cryocooled micromeshes. X-ray diffraction data sets merged from several micrometer-sized crystals are used to determine 1.8 {angstrom} resolution crystal structures.

Soares, Alexei S.; Engel, Matthew A.; Stearns, Richard; Datwani, Sammy; Olechno, Joe; Ellson, Richard; Skinner, John M.; Allaire, Marc; Orville, Allen M. (Labcyte); (BNL)

2012-10-25T23:59:59.000Z

311

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

312

Smart meters and energy savings in Italy: Determining the effectiveness of persuasive communication in dwellings  

Science Journals Connector (OSTI)

Abstract To secure a sustainable energy development in the residential sector, attitudes and human behavior need to be modified toward more efficient and conscious energy usage. The goal of this research is to assess evaluations and to test the effectiveness in reducing domestic electricity consumption. The aim of the smart monitoring system we evaluate is to provide households with a user-friendly tool that improves awareness of energy behavior in homes, enabling better management via the visualization of consumption and persuasive tailored information on domestic electricity use. In our study, the system was tested on 31 Italian families selected among volunteers all over Italy, participating to the first trial phase from October 2012 to November 2013. A combination of persuasive communication strategies such as graphical real-time and historical feedback based on real data and comparison tools to encourage competitiveness against “similar” households were provided to users through a domestic user-friendly interface. In addition, personalized energy saving prompts were sent via web-newsletters to trial users. The study concludes that energy related persuasive communication is effective in reducing electricity consumption in dwellings on average ?18% and up to ?57%.

Simona D’Oca; Stefano P. Corgnati; Tiziana Buso

2014-01-01T23:59:59.000Z

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

The variability of high-frequency acoustic backscatter from the region near the sea surface  

Science Journals Connector (OSTI)

The temporal variability of acoustic backscattering from the region near the sea surface is examined for frequencies in the 30–70 kHz range. A variance spectrum of the scattering strength exhibits effects associated with three different processes. Below about 0.1 Hz the spectrum contains a large contribution associated with temporal variations in the advection of bubble clouds through the measurement volume by large-scale processes. At high frequencies the spectrum asymptotes to a level characteristic of a Gaussian backscatteredpressure field from randomly moving bubbles within the scattering volume. The overall variability is treated as a slow modulation of this Gaussian process by larger-scale processes and a probability density function is derived for the scattering strength using Bayes’ theorem. Finally in some cases the spectrum exhibits a peak at the frequency of the dominant surface waves. Attempts to compute coherence functions between the backscattered acoustic power and surface wave orbital velocities measured by a microwave system observing the same spot as the acoustic system resulted in very low values. This leads to the belief that the wave-induced peak in the acoustic backscatter variance spectrum is caused by highly nonlinear processes. A time series of acoustic backscatter from a vertically pointing system confirms the existence of this modulation at the dominant wave frequency and also suggests its nonlinear character.

Peter H. Dahl; William J. Plant

1997-01-01T23:59:59.000Z

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

Simulations of pressure fluctuations and acoustic emission in hydraulic fracturing  

SciTech Connect (OSTI)

We consider a two-dimensional lattice model to describe the opening of a crack in hydraulic fracturing. In particular, we consider that the material only breaks under tension and the fluid has no pressure drop inside the crack. For the case in which the material is completely homogeneous (no disorder), we present results for pressure and elastic energy as a function of time and compare our findings with some analytic results from continuum fracture mechanics. Then we investigate fracture processes in strongly heterogeneous cohesive environments. We determine the cumulative probability distribution for breaking events of a given energetical magnitude (acoustic emission). Further, we estimate the probability distribution of emission free time intervals. Finally, we determine the fractal dimension(s) of the cracks.

Tzschichholz, F.; Herrmann, H.J. [Division of Physics and Mechanics, School of Technology, Aristotele University of Thessaloniki, 54006 Thessaloniki (Greece)] [Division of Physics and Mechanics, School of Technology, Aristotele University of Thessaloniki, 54006 Thessaloniki (Greece); [HLRZ, Kernforschungsanlage Juelich, Postfach 1913, 5170 Juelich (Germany); [P.M.M.H. (CNRS, URA 857), Ecole Superieuree de Physique et de Chimie Industrielle de la Ville de Paris, 10 rue Vauquelin, 75231 Paris Cedex 05 (France)

1995-03-01T23:59:59.000Z

320

System and method for characterizing, synthesizing, and/or canceling out acoustic signals from inanimate sound sources  

DOE Patents [OSTI]

A system and method for characterizing, synthesizing, and/or canceling out acoustic signals from inanimate sound sources is disclosed. Propagating wave electromagnetic sensors monitor excitation sources in sound producing systems, such as machines, musical instruments, and various other structures. Acoustical output from these sound producing systems is also monitored. From such information, a transfer function characterizing the sound producing system is generated. From the transfer function, acoustical output from the sound producing system may be synthesized or canceled. The methods disclosed enable accurate calculation of matched transfer functions relating specific excitations to specific acoustical outputs. Knowledge of such signals and functions can be used to effect various sound replication, sound source identification, and sound cancellation applications.

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

2007-10-16T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

322

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

323

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

324

QUANTITATIVE DAMAGE ASSESSMENT OF HYBRID COMPOSITE WIND TURBINE BLADES BY ENERGY BASED ACOUSTIC EMISSION SOURCE  

E-Print Network [OSTI]

energy with higher efficiency and cost-effective considerations, the size of the wind turbine blade hasQUANTITATIVE DAMAGE ASSESSMENT OF HYBRID COMPOSITE WIND TURBINE BLADES BY ENERGY BASED ACOUSTIC in the wind turbine blade. It was tried to apply a new source location method, which has a developed algorithm

Boyer, Edmond

325

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.

326

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

327

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

328

Effect of fractures on reserve calculations as determined by petrology: Birthright field, Hopkins County, Texas  

SciTech Connect (OSTI)

Birthright field in Hopkins County, Texas, produces oil and gas from Jurassic carbonate grainstone deposits of the upper Smackover Formation. The field was discovered in 1965 by the drilling of the Schneider and Corey 1 E.M. Strode well. This well initially tested 491 BOPD from a 34-ft interval at 9,519 ft. The field has an oil-water contact at subsea 9,090 ft and a gas-oil contact at subsea 8,980 ft. Ten wells were originally drilled in the 800-ac field, but only six oil and one gas wells were put on production. The estimated in-place reserves in 1969 were 6.4 million bbl oil, 1.3 million bbl condensate, and 14.97 bcf gas, with an estimated primary recovery of 22%. The total cumulative oil production to 1986 was 3.19 million bbl oil. The grainstones of the producing interval are composed of ooids, pisoids, pelecypod fragments, grapestones, and fecal pellets. This shallow marine bar deposit has been extensively leached and cemented. Fracturing and brecciation have taken place causing many grains to be broken and sheared. Many grains have been coated by early diagenetic fibrous rim cement indicative of leaching in vadose and phreatic conditions. These conditions have caused significant variations in the structural conditions and sizes of the coated grains. Anhydrite and sparry calcite have subsequently filled many of the pores, especially below the oil-water contact. It is though that these factors may have affected actual recoverable reserves, and that petrology can be an effective tool in reservoir evaluation, especially where recovered reserves are greater than had been initially calculated.

Mitchell-Tapping, H.J. (GeoResearch International, Dallas, TX (USA))

1989-09-01T23:59:59.000Z

329

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

330

The determinants of fuel use in the trucking industry—volume, fleet characteristics and the rebound effect  

Science Journals Connector (OSTI)

This paper studies the determinants of fuel use in the trucking industry in Denmark, using aggregate time series data for the period 1980–2007. The model captures the main linkages between the demand for freight transport, the characteristics of the vehicle fleet, and the demand for fuel. Results include the following. First, we precisely define and estimate a rebound effect of improvements in fuel efficiency in the trucking industry: behavioural adjustments in the industry imply that an exogenous improvement in fuel efficiency reduces fuel use less than proportionately. Our best estimate of this effect is approximately 10 % in the short run and 17 % in the long run, so that a 1% improvement in fuel efficiency reduces fuel use by 0.90% (short-run) to 0.83% (long-run). Second, we find that higher fuel prices raise the average capacity of trucks, and they induce firms to invest in newer, typically more fuel efficient, trucks. Third, these adjustments and the rebound effect jointly imply that the effect of higher fuel prices on fuel use in the trucking industry is fairly small; estimated price elasticities are ? 0.13 and ? 0.22 in the short run and in the long run, respectively. The empirical results of this paper have implications for judging the implications of fuel efficiency standards and regulations with respect to larger trucks in the EU.

Bruno De Borger; Ismir Mulalic

2012-01-01T23:59:59.000Z

331

Electron effective mass in Al{sub 0.72}Ga{sub 0.28}N alloys determined by mid-infrared optical Hall effect  

SciTech Connect (OSTI)

The effective electron mass parameter in Si-doped Al{sub 0.72}Ga{sub 0.28}N is determined to be m{sup ?}=(0.336±0.020)?m{sub 0} from mid-infrared optical Hall effect measurements. No significant anisotropy of the effective electron mass parameter is found supporting theoretical predictions. Assuming a linear change of the effective electron mass with the Al content in AlGaN alloys and m{sup ?}=0.232?m{sub 0} for GaN, an average effective electron mass of m{sup ?}=0.376?m{sub 0} can be extrapolated for AlN. The analysis of mid-infrared spectroscopic ellipsometry measurements further confirms the two phonon mode behavior of the E{sub 1}(TO) and one phonon mode behavior of the A{sub 1}(LO) phonon mode in high-Al-content AlGaN alloys as seen in previous Raman scattering studies.

Schöche, S., E-mail: schoeche@huskers.unl.edu; Kühne, P.; Hofmann, T.; Schubert, M. [Department of Electrical Engineering and CNFM, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588-0511 (United States)] [Department of Electrical Engineering and CNFM, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588-0511 (United States); Nilsson, D.; Kakanakova-Georgieva, A.; Janzén, E.; Darakchieva, V. [Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, 581 83 (Sweden)] [Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, 581 83 (Sweden)

2013-11-18T23:59:59.000Z

332

Head-on collision of dust-acoustic shock waves in strongly coupled dusty plasmas  

SciTech Connect (OSTI)

A theoretical investigation is carried out to study the propagation and the head-on collision of dust-acoustic (DA) shock waves in a strongly coupled dusty plasma consisting of negative dust fluid, Maxwellian distributed electrons and ions. Applying the extended Poincaré–Lighthill–Kuo method, a couple of Korteweg–deVries–Burgers equations for describing DA shock waves are derived. This study is a first attempt to deduce the analytical phase shifts of DA shock waves after collision. The impacts of physical parameters such as the kinematic viscosity, the unperturbed electron-to-dust density ratio, parameter determining the effect of polarization force, the ion-to-electron temperature ratio, and the effective dust temperature-to-ion temperature ratio on the structure and the collision of DA shock waves are examined. In addition, the results reveal the increase of the strength and the steepness of DA shock waves as the above mentioned parameters increase, which in turn leads to the increase of the phase shifts of DA shock waves after collision. The present model may be useful to describe the structure and the collision of DA shock waves in space and laboratory dusty plasmas.

EL-Shamy, E. F., E-mail: emadel-shamy@hotmail.com [Department of physics, Faculty of Science, Damietta University, New Damietta 34517 (Egypt); Department of Physics, College of Science, King Khalid University, P.O. 9004, Abha (Saudi Arabia); Al-Asbali, A. M., E-mail: aliaa-ma@hotmail.com [Department of Physics, College of Science for Girls in Abha, King Khalid University, Abha, P.O. 960 (Saudi Arabia)

2014-09-15T23:59:59.000Z

333

Acoustic condition monitoring of wind turbines: Tip faults  

Science Journals Connector (OSTI)

As a significant and growing source of the world’s energy wind turbine reliability is becoming a major concern. At least two fault detection techniques for condition monitoring of wind turbine blades have been reported in early literature i.e. acoustic emissions and optical strain sensors. These require off-site measurement. The work presented here offers an alternative non-contact fault detection method based on the noise emission from the turbine during operation. An investigation has been carried out on a micro wind turbine under laboratory conditions. 4 severity levels for a fault have been planted in the form of added weight at the tip of one blade to simulate inhomogeneous debris or ice build up. Acoustic data is obtained at a single microphone placed in front of the rotor. Two prediction methods have been developed and tested on real data: one based on a single feature - rotational frequency spectral magnitude; and another based on a fuzzy logic interference using two inputs - spectral peak and rotational peak variation with time. Results show that the single spectral peak feature can be used to determine fault severity in ranges. The implementation of the fuzzy logic using a further input feature is shown to significantly improve the detection accuracy.

Daniel J. Comboni; Bruno Fazenda

2012-01-01T23:59:59.000Z

334

Mean, variance, and temporal coherence of the 3D acoustic field forward propagated through random inhomogeneities in continental-shelf and deep ocean waveguides  

E-Print Network [OSTI]

When an acoustic field propagates through a multimodal waveguide, the effect of variations in medium properties induced by 3D random inhomogeneities accumulates by multiple forward scattering over range. This causes ...

Chen, Tianrun

2009-01-01T23:59:59.000Z

335

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

336

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

337

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

338

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.

339

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

340

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

342

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

343

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

344

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

345

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

346

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

347

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

348

Physical acoustic information for magnitude estimation of rate of speech  

Science Journals Connector (OSTI)

Several studies have demonstrated that the phonetic identity of a segment can be altered by the rate of a precursive sequence. While this rate normalization effect has been shown for both consonants and vowels [J. L. Miller Phonetica 38 159–180(1981)] it has never been clear what the physical acoustic basis of the rate information is. In these experiments subjects' magnitude estimations of rate for a short passage are used to assess the physical acoustic parameters used by the listener to perceive rate of speech. From earlier experiments [F. Grosjean and N. Lass Lang. Speech20(3) 198–208(1977)] it appears likely that the source of information for rate is not based upon any higher information including words or word boundaries. In the first experiment subjects give rate estimations for a passage spoken at five rates by a female English speaker that has been low?pass filtered at 300 Hz. Estimates for these filtered stimuli in which energy for F1 and higher formants is deleted leaving only pitch and amplitude information are indistinguishable from those for intact passages. It appears then that not even phonetic perception is necessary for perception of rate in this paradigm. Data for estimates of rate for passages with only pitch or only amplitude information will also be presented. [Work supported by NINCDS.

Keith R. Kluender

1984-01-01T23:59:59.000Z

349

Classification of heart valve condition using acoustic measurements  

SciTech Connect (OSTI)

Prosthetic heart valves and the many great strides in valve design have been responsible for extending the life spans of many people with serious heart conditions. Even though the prosthetic valves are extremely reliable, they are eventually susceptible to long-term fatigue and structural failure effects expected from mechanical devices operating over long periods of time. The purpose of our work is to classify the condition of in vivo Bjork-Shiley Convexo-Concave (BSCC) heart valves by processing acoustic measurements of heart valve sounds. The structural failures of interest for Bscc valves is called single leg separation (SLS). SLS can occur if the outlet strut cracks and separates from the main structure of the valve. We measure acoustic opening and closing sounds (waveforms) using high sensitivity contact microphones on the patient`s thorax. For our analysis, we focus our processing and classification efforts on the opening sounds because they yield direct information about outlet strut condition with minimal distortion caused by energy radiated from the valve disc.

Clark, G. [Lawrence Livermore National Lab., CA (United States)

1994-11-15T23:59:59.000Z

350

Acoustic monitoring of severe weather in the Northeast Pacific Ocean.  

Science Journals Connector (OSTI)

Wind and rainfall are the principal physical processes responsible for the production of high?frequency (1–50 kHz) ambient sound in the ocean. The primary source of the sound is the resonant ringing of individual bubbles created during wave breaking and raindrop splashes. Larger bubbles (>300 ?m diameter) quickly return to the surface while smaller bubbles can be mixed downward at several meters. During severe weather a layer of smaller ambient bubble forms and effectively absorbs higher?frequency (>10 kHz) sound. These processes are revealed in a two?year record of ambient sound recorded from a subsurface mooring at 50N 145W in the NE Pacific Ocean as part of the Canadian SOLAS program. The passive acoustic signal of wind rain and ambient bubbleclouds are compared to the subsurface mooring data including data from an upward looking 200 kHz active sonar and a 300 kHz ADCP. The acoustic signatures of light moderate and heavy rainfall are superimposed on the signature of high wind demonstrating rainfall detection even in the presence of high wind. [Work supported by ONR Fisheries and Oceans Canada and the Canadian CFCAS NSERC.

2008-01-01T23:59:59.000Z

351

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

352

Determination of saccharides and ethanol from biomass conversion using Raman spectroscopy: Effects of pretreatment and enzyme composition  

SciTech Connect (OSTI)

This dissertation focuses on the development of facile and rapid quantitative Raman spectroscopy measurements for the determination of conversion products in producing bioethanol from corn stover. Raman spectroscopy was chosen to determine glucose, xylose and ethanol in complex hydrolysis and fermentation matrices. Chapter 1 describes the motives and main goals of this work, and includes an introduction to biomass, commonly used pretreatment methods, hydrolysis and fermentation reactions. The principles of Raman spectroscopy, its advantages and applications related to biomass analysis are also illustrated. Chapter 2 and 3 comprise two published or submitted manuscripts, and the thesis concludes with an appendix. In Chapter 2, a Raman spectroscopic protocol is described to study the efficiency of enzymatic hydrolysis of cellulose by measuring the main product in hydrolysate, glucose. Two commonly utilized pretreatment methods were investigated in order to understand their effect on glucose measurements by Raman spectroscopy. Second, a similar method was set up to determine the concentration of ethanol in fermentation broth. Both of these measurements are challenged by the presence of complex matrices. In Chapter 3, a quantitative comparison of pretreatment protocols and the effect of enzyme composition are studied using systematic methods. A multipeak fitting algorithm was developed to analyze spectra of hydrolysate containing two analytes: glucose and xylose. Chapter 4 concludes with a future perspective of this research area. An appendix describes a convenient, rapid spectrophotometric method developed to measure cadmium in water. This method requires relatively low cost instrumentation and can be used in microgravity, such as space shuttles or the International Space Station. This work was performed under the supervision of Professor Marc Porter while at Iowa State University. Research related to producing biofuel from bio-renewable resources, especially bioethanol from biomass, has grown significantly in the past decade due to the high demand and rising costs of fossil fuels. More than 3 percent of the energy consumption in the U.S. is derived from renewable biomass, mostly through industrial heat and steam production by the pulp and paper industry, and electricity generation from municipal solid waste (MSW) and forest industry residues. The utilization of food-based biomass to make fuels has been widely criticized because it may increase food shortages throughout the world and raise the cost of food. Thus, nonfood-based and plentiful lignocellulosic feedstocks, such as corn stover, perennial grass, bagasse, sorghum, wheat/rice straw, herbaceous and woody crops, have great potential to be new bio-renewable sources for energy production. Given that many varieties of biomass are available, there is need for a rapid, simple, high-throughput method to screen the conversion of many plant varieties. The most suitable species for each geographic region must be determined, as well as the optimal stage of harvest, impacts of environmental conditions (temperature, soil, pH, etc.). Various genetically modified plants should be studied in order to establish the desired biomass in bioethanol production. The main screening challenge, however, is the complexity of plant cell wall structures that make reliable and sensitive analysis difficult. To date, one of the most popular methods to produce lignocellulosic ethanol is to perform enzymatic hydrolysis followed by fermentation of the hydrolysate with yeast. There are several vital needs related to the field of chemistry that have been suggested as primary research foci needed to effectively improve lignocellulosic ethanol production. These topics include overcoming the recalcitrance of cellulosic biomass, the pervasiveness of pretreatment, advanced biological processing and better feedstocks. In this thesis, a novel approach using Raman spectroscopy has been developed to address important issues related to bioethanol generation, which will aid the research aimed to solve the topics m

Shih, Chien-Ju

2010-05-16T23:59:59.000Z

353

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

354

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

355

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.

356

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

357

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

358

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

359

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

360

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

362

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

363

Thermal Acoustic Sensor for High Pulse Energy X-ray FEL Beams  

SciTech Connect (OSTI)

The pulse energy density of X-ray FELs will saturate or destroy conventional X-ray diagnostics, and the use of large beam attenuation will result in a beam that is dominated by harmonics. We present preliminary results at the LCLS from a pulse energy detector based on the thermal acoustic effect. In this type of detector an X-ray resistant material (boron carbide in this system) intercepts the beam. The pulse heating of the target material produces an acoustic pulse that can be detected with high frequency microphones to produce a signal that is linear in the absorbed energy. The thermal acoustic detector is designed to provide first- and second-order calorimetric measurement of X-ray FEL pulse energy. The first-order calorimetry is a direct temperature measurement of a target designed to absorb all or most of the FEL pulse power with minimal heat leak. The second-order measurement detects the vibration caused by the rapid thermoelastic expansion of the target material each time it absorbs a photon pulse. Both the temperature change and the amplitude of the acoustic signal are directly related to the photon pulse energy.

Smith, T.J.; Frisch, J.C.; Kraft, E.M.; Loos, J.; /SLAC; Bentsen, G.S.; /Rochester U.

2011-12-13T23:59:59.000Z

364

Field-scale acoustic investigation of a damaged anisotropic shale during a gallery excavation  

Science Journals Connector (OSTI)

In the Opalinus Clay formation at the Mont Terri Underground Rock Laboratory, the gallery Ga08 was excavated in August 2008 to join the end-face of the pre-existing gallery Ga04. The aim of the present work was to perform in situ acoustic experiments to monitor the evolution of the Excavation Damaged Zone (EDZ) induced during the gallery construction. The end-face of Ga04 was instrumented with two arrays of acoustic transducers allowing for the active and passive seismic monitoring, i.e. acoustic survey and micro-seismicity. From the acoustic survey data, which required a high energy acoustic source to emit high frequency signals (21, 25, 31 and 38 kHz), the rock mass was observed to be anisotropic and heterogeneous at the scale of the experiment. P-wave velocities were determined to be, in average, between 3300 m/s along a structural bedding plane, and 2700 m/s at ? ? 70 ° incidence relative to that. Assuming a transversely isotropic shale formation, the P-wave velocity dependence versus ? was modeled using Thomsen's Weak Transverse Isotropy model (Thomsen, 1986) [36]. Thomsen's P-wave anisotropy parameter was found to be ? ? 0.15 , and the fifth Thomsen's parameter controlling the deviation of the wave front from an ellipsoidal geometry was found to be ? ? 0.16 . The S-wave velocity was estimated along a single direction of aligned receivers and turned out to be around 1560 m/s at ? ? 30 ° . We also show that the rock mass acts as a frequency filter for acoustic waves, related to the rock mass heterogeneities, i.e. the inter-bedding structure, which induces wave scattering and refraction. From the micro-seismicity data, we identified a large number of micro-seismic events (MSEs) detected on the acoustic arrays during and following the excavation. Most of the \\{MSEs\\} were induced on the excavated face but we also located some \\{MSEs\\} inside the rock mass itself. We show that these events are located close to a major fault, which seems to be reactivated by the excavation process.

Y. Le Gonidec; A. Schubnel; J. Wassermann; D. Gibert; C. Nussbaum; B. Kergosien; J. Sarout; A. Maineult; Y. Guéguen

2012-01-01T23:59:59.000Z

365

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

366

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

367

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

368

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

369

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

370

Tidal signals in basin?scale acoustic transmissions  

Science Journals Connector (OSTI)

Travel times of acoustic signals were measured between a bottom?mounted source near Oahu and five bottom?mounted receivers located near Washington Oregon and California in 1988 and 1989. At three out of five receivers observed travel times at M2 and S2 periods agree with predictions from a barotropic tide model to within 30 deg in phase and a factor of 1.6?in. amplitude. The discrepancies at the fourth and fifth receivers can be removed to first order by including predicted effects of phase?locked baroclinic tides generated by guyots in the Moonless mountains. A simple model is used to estimate the conversion of energy from barotropic to baroclinic tides by the world’s seamounts. At M2 the conversion amounts to about 4% of the total dissipation at M2. Although this estimate is very approximate it is similar to other published values.

John L. Spiesberger; Robert H. Headrick; Paul J. Bushong

1992-01-01T23:59:59.000Z

371

Surface acoustic wave interaction with thin magnetic films  

Science Journals Connector (OSTI)

It has been found that surface acoustic waves(SAW) exhibit a very large interaction with appropriately prepared thin magnetic films through the magnetoelasticeffect. For a 600 Å 90Ni 10Fe thin film the interaction can produce changes in attenuation of 30 dB/cm at 700 MHz by changing from 2 to 12 G a magnetic field applied parallel to the film plane and perpendicular to the SAW.Measurements of the frequency dependence of this large effect yield values for the Gilbert damping constant and the anisotropy field. This interaction has been studied in the series of xNi (1 ? x)Fe alloy films. For x > 80 wt % the magnetoelastic constant ? is negative. It is positive for x Science Foundation under Grant No. ESC 8519695.

Moises Levy; Roy Wiegert

1986-01-01T23:59:59.000Z

372

Stopbands in the existence domains of acoustic solitons  

SciTech Connect (OSTI)

A fully nonlinear Sagdeev pseudopotential approach is used to study the existence domain of fast mode ion-acoustic solitons in a three-species plasma composed of cold and warm adiabatic positive ion species and Boltzmann electrons. It is shown that for appropriate values of the cold-to-warm ion charge-to-mass ratio, ?, and the effective warm ion-to-electron temperature ratio, ?, there is a range in cold to warm ion charge density ratio, f, over which a stopband in soliton speed exists. Solitons do not propagate in the stopband, although they can occur for both higher and lower speeds. The stopbands are associated with a limiting curve of the existence domain that is double-valued in speed for a range of values of f. Analytical estimates of the upper and lower limits of ? and ? that support stopbands are found. It is suggested that, inter alia, the analysis should be applicable to the solar wind plasma.

Nsengiyumva, F., E-mail: franco.nseng@gmail.com; Hellberg, M. A., E-mail: hellberg@ukzn.ac.za; Mace, R. L., E-mail: macer@ukzn.ac.za [School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000 (South Africa); Verheest, F., E-mail: frank.verheest@ugent.be [School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000 (South Africa); Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281, B–9000 Gent (Belgium)

2014-10-15T23:59:59.000Z

373

Generation of Geodesic Acoustic Modes in ITG turbulence  

SciTech Connect (OSTI)

The generation of geodesic acoustic modes (GAM) is studied by means of numerical simulations of a 3D fluid global model, describing flux-driven electrostatic ITG (Ion Temperature Gradient) turbulence in the core of tokamak plasmas. The model evolves the equilibrium and the perturbed fields as a whole. The coupling of poloidal harmonics induced by the curvature thus results in the presence of both turbulent and neoclassical transport effects in the system. The neoclassical thermal conductivity, which is linked to the time-independent component of the poloidal modulation of the equilibrium fields, is observed to be of the order of the turbulent one, in a system driven by strong injected heat fluxes. The frequency spectrum of the electrostatic potential fluctuations exhibits a peak near the theoretical GAM frequency. In the turbulent stationary state of the simulations a downshift of the GAM frequency is observed.

Falchetto, G. L.; Garbet, X.; Ottaviani, M. [Association EURATOM-CEA, CEA/DSM/DRFC, Centre de Cadarache, 13108 Saint Paul lez Durance (France); Smolyakov, A. [Department of Physics and Engineering Physics, University of Saskatchewan, SK (Canada)

2006-11-30T23:59:59.000Z

374

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

375

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...

376

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

377

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

378

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...

379

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...

380

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

A Study to Determine the Effectiveness of Agriculture/Natural Resource Program Area Committees on the Texas AgriLife Extension Service Program Planning Process  

E-Print Network [OSTI]

of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF EDUCATION August 2011 Major Subject: Agricultural Leadership, Education, and Communications A STUDY TO DETERMINE..., Jack Elliot August 2011 Major Subject: Agricultural Leadership, Education, and Communications iii ABSTRACT A Study to Determine the Effectiveness of Agriculture/Natural Resource Program Area Committees on the Texas AgriLife Extension...

Weems, Whit Holland

2011-10-21T23:59:59.000Z

382

Argon–oxygen dc magnetron discharge plasma probed with ion acoustic waves  

SciTech Connect (OSTI)

The precise determination of the relative concentration of negative ions is very important for the optimization of magnetron sputtering processes, especially for those undertaken in a multicomponent background produced by adding electronegative gases, such as oxygen, to the discharge. The temporal behavior of an ion acoustic wave excited from a stainless steel grid inside the plasma chamber is used to determine the relative negative ion concentration in the magnetron discharge plasma. The phase velocity of the ion acoustic wave in the presence of negative ions is found to be faster than in a pure argon plasma, and the phase velocity increases with the oxygen partial pressure. Optical emission spectroscopy further confirms the increase in the oxygen negative ion density, along with a decrease in the argon positive ion density under the same discharge conditions. The relative negative ion concentration values measured by ion acoustic waves are compared with those measured by a single Langmuir probe, and a similarity in the results obtained by both techniques is observed.

Saikia, Partha, E-mail: partha.008@gmail.com; Saikia, Bipul Kumar; Goswami, Kalyan Sindhu [Centre of Plasma Physics, Institute for Plasma Research, Nazirakhat, Sonapur, Kamrup, Assam 782 402 (India); Phukan, Arindam [Madhabdev College, Narayanpur, Lakhimpur, Assam 784164 (India)

2014-05-15T23:59:59.000Z

383

Interference mechanisms of acoustic/convective disturbances in a swirl-stabilized lean-premixed combustor  

Science Journals Connector (OSTI)

Interference mechanisms of acoustic/convective disturbances were experimentally investigated in a swirl-stabilized lean-premixed gas turbine combustor operated with natural gas fuel and air at atmospheric pressure and elevated temperature. Interference between azimuthal and acoustic velocity disturbances at high-amplitude limit cycle oscillations is characterized in detail as a function of axial swirler location, oscillation frequency, and mean nozzle velocity. We show that both the frequency and the intensity of self-excited instabilities in a model gas turbine combustor are correlated with axial swirler position, which indicates that a vorticity wave generated at the swirl vanes is a primary source of convective disturbances in the absence of equivalence ratio nonuniformities. Flame transfer function measurements confirm that the linear/nonlinear heat release response is a strong function of axial swirler location, even when unforced flame structures remain unchanged. The key parameter controlling this phenomenon is the phase difference between the azimuthal and acoustic velocity perturbations at the combustor dump plane; the phase difference is affected by swirler location, frequency, mean velocity, and the speed of sound. It was found that out-of-phase interference between azimuthal and acoustic velocity disturbances at the combustor inlet yields large flame angle fluctuations in relation to swirl number fluctuations, and therefore the formation of a coherent structure is hindered due to high kinematic viscosity within the vortex formation region. In-phase interference mechanisms, on the other hand, lead to high-amplitude limit cycle oscillations. This interference mechanism is then explored in the presence of temporal equivalence ratio nonuniformities, in which two different sources of convective mechanisms should be considered simultaneously in connection with acoustic velocity perturbations and the vortex dynamics. Results reveal that equivalence ratio oscillation has a significant effect on the strength of combustion-acoustic interactions. Strong self-excited instabilities of partially premixed flames are produced by in-phase interactions between acoustic velocity and equivalence ratio oscillations, which are governed by fuel injection location, frequency, mean nozzle velocity, and fuel injector impedance. At this phase condition, unburned reactants with high equivalence ratio impinge on the flame front with high inlet velocity, potentially causing large fluctuations of heat release rate.

Kyu Tae Kim; Dom A. Santavicca

2013-01-01T23:59:59.000Z

384

Acoustic Probing of the Jamming Transition in an Unconsolidated Granular Medium  

E-Print Network [OSTI]

Experiments with acoustic waves guided along the mechanically free surface of an unconsolidated granular packed structure provide information on the elasticity of granular media at very low pressures that are naturally controlled by the gravitational acceleration and the depth beneath the surface. Comparison of the determined dispersion relations for guided surface acoustic modes with a theoretical model reveals the dependencies of the elastic moduli of the granular medium on pressure. The experiments confirm recent theoretical predictions that relaxation of the disordered granular packing through non-affine motion leads to a peculiar scaling of shear rigidity with pressure near the jamming transition corresponding to zero pressure. Unexpectedly, and in disagreement with the most of the available theories, the bulk modulus depends on pressure in a very similar way to the shear modulus.

Jacob, Xavier; Tournat, Vincent; Leclaire, Philippe; Lauriks, Walter; Gusev, Vitalyi

2007-01-01T23:59:59.000Z

385

Acoustic Probing of the Jamming Transition in an Unconsolidated Granular Medium  

E-Print Network [OSTI]

Experiments with acoustic waves guided along the mechanically free surface of an unconsolidated granular packed structure provide information on the elasticity of granular media at very low pressures that are naturally controlled by the gravitational acceleration and the depth beneath the surface. Comparison of the determined dispersion relations for guided surface acoustic modes with a theoretical model reveals the dependencies of the elastic moduli of the granular medium on pressure. The experiments confirm recent theoretical predictions that relaxation of the disordered granular packing through non-affine motion leads to a peculiar scaling of shear rigidity with pressure near the jamming transition corresponding to zero pressure. Unexpectedly, and in disagreement with the most of the available theories, the bulk modulus depends on pressure in a very similar way to the shear modulus.

Xavier Jacob; Vladislav Aleshin; Vincent Tournat; Philippe Leclaire; Walter Lauriks; Vitalyi Gusev

2007-10-11T23:59:59.000Z

386

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...

387

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...

388

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...

389

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...

390

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...

391

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...

392

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,...

393

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...

394

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...

395

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....

396

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 ......

397

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...

398

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...

399

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...

400

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...

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


401

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...

402

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...

403

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...

404

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...

405

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 ...

406

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...

407

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...

408

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

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

409

Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival Proportions at John Day Dam, 2009  

SciTech Connect (OSTI)

The overall purpose of the acoustic telemetry study at JDA during 2009 was to determine the best configuration and operation for JDA prior to conducting BiOp performance standard tests. The primary objective was to determine the best operation between 30% and 40% spill treatments. Route-specific and JDA to TDA forebay survival estimates, passage distribution, and timing/behavior metrics were used for comparison of 30% to a 40% spill treatments. A secondary objective was to evaluate the performance of TSWs installed in spill bays 15 and 16 and to estimate fish survival rates and passage efficiencies under 30% and 40% spill-discharge treatments each season.

Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.; Deng, Zhiqun; Fu, Tao; Kim, Jin A.; Johnson, Gary E.; Fischer, Eric S.; Khan, Fenton; Zimmerman, Shon A.; Faber, Derrek M.; Carter, Kathleen M.; Boyd, James W.; Townsend, Richard L.; Skalski, J. R.; Monter, Tyrell J.; Cushing, Aaron W.; Wilberding, Matthew C.; Meyer, Matthew M.

2011-09-28T23:59:59.000Z

410

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

411

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

412

Systems theory in musical acoustics  

Science Journals Connector (OSTI)

Recent digital synthesis techniques for woodwind bores and strings (bowed plucked and the like) have been devised using long delay lines and sparsely distributed filter elements to efficiently simulate solutions to the one?dimensional wave equation. In the simplest case a string or bore can be modeled using a single delay line and a single low?order digital filter. This presentation describes techniques used to simulate specific physical phenomena in the context of these models. As is well known in the lossless case solutions to the 1?D wave equation can be expressed in terms of left?going and right?going traveling waves and these are efficiently simulated using pure delay lines plus perhaps a sign inversion at a termination. Abutting two waveguides of differing characteristic impedance gives rise to a scattering junction at the interface leading to the ladder and lattice digital filter structures used extensively in the field of signal processing. When there are losses or when string stiffness is important there is linear filtering along the waveguide. Because linear time?invariant filters commute the distributed losses and dispersion can be lumped at convenient places in the waveguide network without changing an input?output transfer function. Once they are thus consolidated it is usually possible especially in audio applications to find a very accurate approximation using a low?order lumped digital filter in place of the distributed filtering. On top of this physically accurate yet efficient model it is straightforward to introduce nonlinear extensions such as (1) bow?string slippage due to absolute string displacement (2) pitch decay due to the gradual decline of the average string tension (3) wave?front sharpening due to increased speed of sound at higher air pressures (4) closure forces on double reeds and vocal folds due to the Bernoulli effect (5) heat conduction losses and (6) spontaneous generation of turbulence due to high volume velocity through a narrow aperture.

Julius O. Smith III

1990-01-01T23:59:59.000Z

413

Thermo-acoustic Sound Generation in the Interaction of Pulsed Proton and Laser Beams with a Water Target  

E-Print Network [OSTI]

The generation of hydrodynamic radiation in interactions of pulsed proton and laser beams with matter is explored. The beams were directed into a water target and the resulting acoustic signals were recorded with pressure sensitive sensors. Measurements were performed with varying pulse energies, sensor positions, beam diameters and temperatures. The obtained data are matched by simulation results based on the thermo-acoustic model with uncertainties at a level of 10%. The results imply that the primary mechanism for sound generation by the energy deposition of particles propagating in water is the local heating of the medium. The heating results in a fast expansion or contraction and a pressure pulse of bipolar shape is emitted into the surrounding medium. An interesting, widely discussed application of this effect could be the detection of ultra-high energetic cosmic neutrinos in future large-scale acoustic neutrino detectors. For this application a validation of the sound generation mechanism to high accur...

Lahmann, R; Graf, K; Hößl, J; Kappes, A; Katz, U; Mecke, K; Schwemmer, S

2015-01-01T23:59:59.000Z

414

Test of Sabine’s reverberation time in ergodic auditoriums within geometrical acoustics  

Science Journals Connector (OSTI)

In room acoustics Sabine’s formula for the reverberation time as a function of its volume and effective surface absorption is valid in the limit of a perfectly ‘‘diffuse’’ sound. In the spirit of the general discussion of Joyce [J. Acoust. Soc. Am. 5 8 643 (1975)] in the geometrical acoustic limit and as a paradigm of the complex three?dimensional problem here a simple two?dimensional (2?D) room with the shape of a stadium with smooth boundaries is considered. In this system it is known that almost all trajectories are chaotic in the strongest sense of the term namely ergodic mixing and K?complex. Numerical results are reported on the decay law of an impulse sound and on its characteristic reverberation time as a function of room volume (in 2D the stadium surface) and effective surface absorption (in 2D effective perimeter absorption). In the limit of very small absorptions Sabine’s law is verified with good accuracy. However these results show that larger but still small absorptions lead to a departure from a pure exponential decay. This stems from the existence of finite time correlations that are important at short times.

Olivier Legrand; Didier Sornette

1990-01-01T23:59:59.000Z

415

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

416

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.

417

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

418

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

419

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.

420

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

Note: This page contains sample records for the topic "determination acoustic effects" 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

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

422

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

423

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

424

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

425

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

426

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.

427

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

428

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

429

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

430

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

431

Summary To determine the effects of lifting time and stor-age on water-stress resistance of nursery-grown white spruce  

E-Print Network [OSTI]

assimilation, mesophyll conductance, stomatal conductance, water-use efficiency. Introduction Water stressSummary To determine the effects of lifting time and stor- age on water-stress resistance in January 1992. The seedlings were placed in nutrient solution and subjected to ­1.1 or ­2.7 MPa water

Macdonald, Ellen

432

Determination of aggregate physical properties and its effects on cross-anisotropic behavior of unbound aggregate materials  

E-Print Network [OSTI]

stresses computed within granular layers. Existing pavement analysis and design approaches, however, generally assume the pavement structure to be linear isotropic layered system. This assumption is motivated by the difficulties in determining cross...

Kim, Sung-Hee

2005-11-01T23:59:59.000Z

433

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

434

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

435

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

436

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

437

Patch nearfield acoustic holography in a moving medium  

Science Journals Connector (OSTI)

Abstract To realize the accurate reconstruction of sound field in a moving medium under the condition of limited holographic aperture, a patch nearfield acoustic holography (NAH) in a moving medium is proposed. The proposed method not only reduces the influence caused by the limited aperture effects through sound field extrapolation, but also perfectly suits for sound field reconstruction in a moving medium by improving the shape of the modified Tikhonov regularization filter and the noise estimation method in accordance with flow effects. In the method, two cases that the flow direction is parallel to and perpendicular to the hologram surface are considered. Especially in the perpendicular case, the expression of the wavenumber component in the z direction is improved to make the proposed method suitable for the moving medium at a high Mach number. Simulations are investigated to examine the performance of the proposed method and show its advantages by comparing with NAH in a moving medium and the conventional patch NAH. It is found that, the proposed method is effective and robust at different flow velocities of the medium and different frequencies of the sound source.

Bi-Chun Dong; Chuan-Xing Bi; Xiao-Zheng Zhang; Yong-Bin Zhang

2014-01-01T23:59:59.000Z

438

A survey of the acoustical quality of seventeen libraries at Princeton University  

Science Journals Connector (OSTI)

The purpose of this study was to identify objective acoustic measures that correlate with the subjective responses of students and administrators to libraries at Princeton University. The motivation for this study was to determine what is necessary in order to provide a comfortable acoustic environment for users of a new science library to be built on campus. On 31 March 2003 Acentech Incorporated evaluated 17 library spaces and interviewed a number of students and librarians at Princeton. Based on the results of the survey the author proposes that a comfortable acoustic environment in a library is an environment that provides freedom from distraction; in other words casual conversation and other noises in the library will not distract users reading or studying in the library. In order to provide such an environment a library must have (1) appropriate levels of background sound (2) a physical barrier between noise?producing and noise?sensitive sections and (3) sufficient sound absorbing material in the space. Measured quantitative metrics support these conclusions.

2003-01-01T23:59:59.000Z

439

A simple toy model of the advective-acoustic instability I. Perturbative approach  

E-Print Network [OSTI]

Some general properties of the advective-acoustic instability are described and understood using a toy model which is simple enough to allow for analytical estimates of the eigenfrequencies. The essential ingredients of this model, in the unperturbed regime, are a stationary shock and a subsonic region of deceleration. For the sake of analytical simplicity, the 2D unperturbed flow is parallel and the deceleration is produced adiabatically by an external potential. The instability mechanism is determined unambiguously as the consequence of a cycle between advected and acoustic perturbations. The purely acoustic cycle, considered alone, is proven to be stable in this flow. Its contribution to the instability can be either constructive or destructive. A frequency cut-off is associated to the advection time through the region of deceleration. This cut-off frequency explains why the instability favours eigenmodes with a low frequency and a large horizontal wavelength. The relation between the instability occurring in this highly simplified toy model and the properties of SASI observed in the numerical simulations of stellar core-collapse is discussed. This simple set up is proposed as a benchmark test to evaluate the accuracy, in the linear regime, of numerical simulations involving this instability. We illustrate such benchmark simulations in a companion paper.

T. Foglizzo

2008-12-14T23:59:59.000Z

440

Laser light scattering by bubbles in water: Fundamentals and applications to acoustics.  

Science Journals Connector (OSTI)

Laser light scattering is sometimes used as an alternative to acoustical methods for monitoring bubbles in seawater. There has also been interest in using lasers to investigate bubbles in wakes. In some cases light scattering by bubbles has been used in conjunction with acoustical measurements to characterize dynamics of bubbles radiating sound [J. S. Stroud and P. L. Marston J. Acoust. Soc. Am. 94 2788–2792 (1993)]. In applications such as these it is important to understand the optical properties of bubbles that differ significantly from drops and particles. Examples include critical angle scattering and the transition to total reflection [D. S. Langley and P. L. Marston Appl. Opt. 23 1044–1054 (1984)] forward scattering and extinction [D. S. Langley and P. L. Marston Appl. Opt. 30 3452–3458 (1991); J. S. Stroud and P. L. Marston cited previously] glory back?scattering enhancements and shape effects [W. P. Arnott and P. L. Marston J. Opt. Soc. Am. A5 496–506 (1988); Appl. Opt. 30 3429–3442 (1991)] and Brewster angle scattering. Some optical effects of coatings on bubbles (which can occur naturally) have also been modeled [P. L. Marston Appl. Opt. 30 3479–3484 (1991)]. [Research supported by ONR between 1980 and 1995.

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "determination acoustic effects" 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

Dust acoustic solitary and shock excitations in a Thomas-Fermi magnetoplasma  

SciTech Connect (OSTI)

The linear and nonlinear properties of dust-acoustic waves are investigated in a collisionless Thomas-Fermi magnetoplasma, whose constituents are electrons, ions, and negatively charged dust particles. At dust time scale, the electron and ion number densities follow the Thomas-Fermi distribution, whereas the dust component is described by the classical fluid equations. A linear dispersion relation is analyzed to show that the wave frequencies associated with the upper and lower modes are enhanced with the variation of dust concentration. The effect of the latter is seen more strongly on the upper mode as compared to the lower mode. For nonlinear analysis, we obtain magnetized Korteweg-de Vries (KdV) and Zakharov-Kuznetsov (ZK) equations involving the dust-acoustic solitary waves in the framework of reductive perturbation technique. Furthermore, the shock wave excitations are also studied by allowing dissipation effects in the model, leading to the Korteweg-de Vries-Burgers (KdVB) and ZKB equations. The analysis reveals that the dust-acoustic solitary and shock excitations in a Thomas-Fermi plasma are strongly influenced by the plasma parameters, e.g., dust concentration, dust temperature, obliqueness, magnetic field strength, and dust fluid viscosity. The present results should be important for understanding the solitary and shock excitations in the environments of white dwarfs or supernova, where dust particles can exist.

Rahim, Z.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Ali, S. [National Center for Physics (NCP) at QAU Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan)

2014-07-15T23:59:59.000Z

442

Acoustic measurements for the combustion diagnosis of diesel engines fuelled with biodiesels  

Science Journals Connector (OSTI)

In this paper, an experimental investigation was carried out on the combustion process of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The effects of biodiesel on the combustion process and engine dynamics were analysed for non-intrusive combustion diagnosis based on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine. The signals of vibration, acoustic and in-cylinder pressure were measured simultaneously to find their inter-connection for diagnostic feature extraction. It was found that the sound energy level increases with the increase of engine load and speed, and the sound characteristics are closely correlated with the variation of in-cylinder pressure and combustion process. The continuous wavelet transform (CWT) was employed to analyse the non-stationary nature of engine noise in a higher frequency range. Before the wavelet analysis, time synchronous average (TSA) was used to enhance the signal-to-noise ratio (SNR) of the acoustic signal by suppressing the components which are asynchronous. Based on the root mean square (RMS) values of CWT coefficients, the effects of biodiesel fractions and operating conditions (speed and load) on combustion process and engine dynamics were investigated. The result leads to the potential of airborne acoustic measurements and analysis for engine condition monitoring and fuel quality evaluation.

Dong Zhen; Tie Wang; Fengshou Gu; Belachew Tesfa; Andrew Ball

2013-01-01T23:59:59.000Z

443

Identifying acoustical coupling by measurements and prediction-models for St. Peter’s Basilica in Rome  

Science Journals Connector (OSTI)

St. Peter’s Basilica is one of the largest buildings in the world having a huge volume resulting from the addition of different parts. Consequently sound propagation cannot be interpreted using a conventional approach and requires experimental measures to be compared with statistical-acoustics and geometrical predictions in order to explain the interplay between shape materials and sound waves better. In previous research one of the most evident effects the surprisingly low reverberation time was believed to result from acoustical coupling phenomena. Taking advantage of more refined measuring techniques available today an acoustic survey was carried out and the results were analyzed using different methods including Bayesian parameter estimation of multiple slope decays and directional energy plots which showed that coupling effects actually take place even though measured reverberation times were longer than those given in previous studies. In addition experimental results were compared with geometrical- and statistical-acoustic models of the basilica which showed that careful selection of input data and in statistical models the inclusion of phenomena such as direct sound radiation and non-diffuse energy transfer allow obtaining accurate results. Finally both models demonstrated that reduced reverberation depends more on increased absorption of decorated surfaces than on coupling effects.

Francesco Martellotta

2009-01-01T23:59:59.000Z

444

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

445

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...

446

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...

447

A study to determine the most effective actuation valve and water distribution head combination for emergency showers  

E-Print Network [OSTI]

for corrosion and wear. Pressure test to determine strength. (5) Remove shower head and dismantle. Clean scale and rust, from the head inlet and from the slots or orifices in the baffle plate. (6) Reassemble. (7) Open OSBY valve and replace seal..., and orifice sprinkler water distribution heads to determine which valve/head combination produced the greatest flow rate at varying static water pressures. Flow rates were measured at static pressures of 20, 30. 40, 50, and 60 pounds per square inch gauge...

Presswood, James Columbus

1977-01-01T23:59:59.000Z

448

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

449

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

450

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

451

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

452

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

453

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

454

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

455

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

456

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

457

US DEPARl'lIIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER Nl!PA DETERMINATION  

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

DEPARl'lIIENT OF ENERGY DEPARl'lIIENT OF ENERGY EERE PROJECT MANAGEMENT CENTER Nl!PA DETERMINATION RECIPIENT: Snohomish County PUD PROJECf TITLE: Acoustic Effects of Hydrokinetic Tidal Turbines Page 1 on STATE: WA Funding Opportunity Announcement Number Procurement Instrument Number NEPA Control Number CID Number DE-FOA-0000069 DE-EEOOO2654 GFQ-0002654-OO2 0 Based on my review orlhe Information concerning the proposed action, as NEPA Compliance Officer (authori1.ed under DOE Order 4S1.1A), I have made the following determination: ex, EA, EIS APPENDIX ANO NUMBER: Description: B3.3 Field and laboratory research, inventory, and information collection activities that are directly related to the conservation of fish or wildlife resources and that involve only negligible habitat destruction or population reduction

458

Monitoring of Olympic National Park Beaches to determine fate and effects of spilled bunker C fuel oil  

SciTech Connect (OSTI)

On December 23, 1988, the barge Nestucca was accidentally struck by its tow, a Souse Brothers Towing Company tug, releasing approximately 230,000 gallons of Bunker C fuel oil and fouling beaches from Grays Harbor north to Vancouver Island. Affected beaches in Washington included a 40-mile-long strip that has been recently added to Olympic National Park. The purpose of the monitoring program documented in this report was to determine the fate of spilled Bunker C fuel oil on selected Washington coastal beaches. We sought to determine (1) how much oil remained in intertidal and shallow subtidal habitats following clean-up and weathering, (2) to what extent intertidal and/or shallow subtidal biotic assemblages have been contaminated, and (3) how rapidly the oil has left the ecosystem. 45 refs., 18 figs., 8 tabs.

Strand, J.A.; Cullinan, V.I.; Crecelius, E.A.; Fortman, T.J.; Citterman, R.J.; Fleischmann, M.L.

1990-10-01T23:59:59.000Z

459

Evaluation of the effects of contaminant injection location and injection method on the determination of overall relative room ventilation efficiency  

E-Print Network [OSTI]

. Figure 3. Figure 4. Figure 5. Figure 6. Calculation of zeroeth moment Calculation of first moment. . 29 30 Diagram of flows in and out of a perfectly mixed room. 30 Floor plan of test room. 31 Carbon dioxide concentration versus time for supply... duct injection point and pulse injection method. 32 Example of use of moments to determine mean age of air. . . . 29 Figure 7. Carbon dioxide concentration versus time for short circuit injection point and pulse injection method. 32 Figure 8...

Pierce, Stephen Dale

1994-01-01T23:59:59.000Z

460

Experimental study of acoustic radiation from a boundary layer transition region  

Science Journals Connector (OSTI)

Wall pressurefluctuations were measured on a rigid axisymmetric body in the CEPRA 19 low?noise anechoic wind tunnel using flush?mounted microphones placed from the laminar region to the fully turbulent boundary layer. Microphones placed in the laminar flow region are used to detect noise radiated from the transition region which occurs naturally without separation under a slightly positive pressure gradient. Cross?spectral analyses show upstream acoustic propagation in a very wide frequency band 4–30 kHz detected in the laminar region. A method of conditional analysis is then used to establish the sequence of events from the onset of near?harmonic instability wave packets to the generation about 10 ms later of turbulent spots leading to the acoustic emission. This intermittent acoustic radiation is detected in the nearfield for wind velocities ranging from 20–70 ms. Farfield detection was not achieved probably because of instrument limitations and propagation effects. [Work supported by DRET Direction des Recherches et Etudes Techniques.

J. C. Perraud; A. Julienne

1986-01-01T23:59:59.000Z

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