Science.gov

Sample records for direct acoustic profiling

  1. Highly directional acoustic receivers

    NASA Astrophysics Data System (ADS)

    Cray, Benjamin A.; Evora, Victor M.; Nuttall, Albert H.

    2003-03-01

    The theoretical directivity of a single combined acoustic receiver, a device that can measure many quantities of an acoustic field at a collocated point, is presented here. The formulation is developed using a Taylor series expansion of acoustic pressure about the origin of a Cartesian coordinate system. For example, the quantities measured by a second-order combined receiver, denoted a dyadic sensor, are acoustic pressure, the three orthogonal components of acoustic particle velocity, and the nine spatial gradients of the velocity vector. The power series expansion, which can be of any order, is cast into an expression that defines the directivity of a single receiving element. It is shown that a single highly directional dyadic sensor can have a directivity index of up to 9.5 dB. However, there is a price to pay with highly directive sensors; these sensors can be significantly more sensitive to nonacoustic noise sources.

  2. Direct Field Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Larkin, Paul; Goldstein, Bob

    2008-01-01

    This paper presents an update to the methods and procedures used in Direct Field Acoustic Testing (DFAT). The paper will discuss some of the recent techniques and developments that are currently being used and the future publication of a reference standard. Acoustic testing using commercial sound system components is becoming a popular and cost effective way of generating a required acoustic test environment both in and out of a reverberant chamber. This paper will present the DFAT test method, the usual setup and procedure and the development and use of a closed-loop, narrow-band control system. Narrow-band control of the acoustic PSD allows all standard techniques and procedures currently used in random control to be applied to acoustics and some examples are given. The paper will conclude with a summary of the development of a standard practice guideline that is hoped to be available in the first quarter of next year.

  3. Direct Field Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Larkin, Paul; Goldstein, Bob

    2008-01-01

    This paper presents an update to the methods and procedures used in Direct Field Acoustic Testing (DFAT). The paper will discuss some of the recent techniques and developments that are currently being used and the future publication of a reference standard. Acoustic testing using commercial sound system components is becoming a popular and cost effective way of generating a required acoustic test environment both in and out of a reverberant chamber. This paper will present the DFAT test method, the usual setup and procedure and the development and use of a closed-loop, narrow-band control system. Narrow-band control of the acoustic PSD allows all standard techniques and procedures currently used in random control to be applied to acoustics and some examples are given. The paper will conclude with a summary of the development of a standard practice guideline that is hoped to be available in the first quarter of next year.

  4. Directional Acoustic Density Sensor

    DTIC Science & Technology

    2010-09-13

    fluctuations of fluid density at a point . (2) DESCRIPTION OF THE PRIOR ART [0004] Conventional vector sensors measure particle velocity, v (vx,Vytvz...dipole-type or first order sensor that is realized by measuring particle velocity at a point , (which is the vector sensor sensing approach for...underwater sensors), or by measuring the gradient of the acoustic pressure at two closely spaced (less than the wavelength of an acoustic wave) points as it

  5. Broad-band acoustic Doppler current profiler

    USGS Publications Warehouse

    Cobb, E.D.

    1993-01-01

    The broad-band acoustic Doppler current profiler is an instrument that determines velocity based on the Doppler principle by reflecting acoustic signals off sediment particles in the water. The instrument is capable of measuring velocity magnitude and direction throughout a water column and of measuring water depth. It is also capable of bottom tracking and can, therefore, keep track of its own relative position as it is moved across a channel. Discharge measurements can be made quickly and, based on limited tests, accurately with this instrument. ?? 1993.

  6. High-directivity acoustic antenna

    NASA Technical Reports Server (NTRS)

    El-Sum, H. M. A.

    1974-01-01

    Acoustic antenna with unique electronic steering control is used to identify and define aerodynamic noise sources in free field, particularly in wind tunnel which is quite reverberant. Provision is made for high directivity as well as improved discrimination against unwanted background noise such as reverberation or echoes.

  7. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  8. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  9. Compressive acoustic sound speed profile estimation.

    PubMed

    Bianco, Michael; Gerstoft, Peter

    2016-03-01

    Ocean acoustic sound speed profile (SSP) estimation requires the inversion of acoustic fields using limited observations. Compressive sensing (CS) asserts that certain underdetermined problems can be solved in high resolution, provided their solutions are sparse. Here, CS is used to estimate SSPs in a range-independent shallow ocean by inverting a non-linear acoustic propagation model. It is shown that SSPs can be estimated using CS to resolve fine-scale structure.

  10. Direct Field and Reverberant Chamber Acoustic Test Comparisons

    NASA Technical Reports Server (NTRS)

    OConnell, Michael

    2007-01-01

    Reverberant and direct acoustic test comparisons were analyzed in this viewgraph presentation. The acoustic test data set includes: 1) CloudSat antenna subjected to PF reverberant chamber acoustic test; 2) CloudSat subjected to a PF direct speaker acoustic test; and 3) DAWN flight spacecraft subjected to PF direct speaker and a workmanship reverberant chamber acoustic test.

  11. Direct Field and Reverberant Chamber Acoustic Test Comparisons

    NASA Technical Reports Server (NTRS)

    OConnell, Michael

    2007-01-01

    Reverberant and direct acoustic test comparisons were analyzed in this viewgraph presentation. The acoustic test data set includes: 1) CloudSat antenna subjected to PF reverberant chamber acoustic test; 2) CloudSat subjected to a PF direct speaker acoustic test; and 3) DAWN flight spacecraft subjected to PF direct speaker and a workmanship reverberant chamber acoustic test.

  12. Directivity of acoustic radiation from sources

    NASA Technical Reports Server (NTRS)

    Lansing, D. L.

    1979-01-01

    The radiation properties of acoustic monopoles and dipoles are described, as well as the directivity of radiation from these sources in a free field and in the presence of an absorptive surface. The kinematic effects on source radiation due to translation and rotation are discussed. Experimental measurements of sound from an acoustic monopole in motion and the characteristics of helicopter rotor and propeller noise are reviewed. Several essential concepts required by noise control engineers making measurements of noise from moving sources in the proximity of the ground are introduced.

  13. Directivity of acoustic radiation from sources

    NASA Technical Reports Server (NTRS)

    Lansing, D. L.

    1979-01-01

    The radiation properties of acoustic monopoles and dipoles are described. The directivity of radiation from these sources in a free field and in the presence of an absorptive surface is described. The kinematic effects on source radiation due to translation and rotation are discussed. Experimental measurements of sound from an acoustic monopole in motion and the characteristics of helicopter rotor and propeller noise are reviewed. An introduction is provided to several essential concepts required by noise control engineers making measurements of noise from moving sources in the proximity of the ground.

  14. MEMS direction finding acoustic sensor

    NASA Astrophysics Data System (ADS)

    Karunasiri, Gamani; Alves, Fabio; Swan, William

    2017-06-01

    Conventional directional sound sensing systems employ an array of spatially separated microphones to achieve directivity. However, there are insects such as the Ormia ochracea fly that can determine the direction of sound using a miniature hearing organ much smaller than the wavelength of sound it detects. The fly's eardrums are coupled mechanically with a separation of only 0.5 mm and yet have a remarkable sensitivity to the direction of sound. The MEMS based sensor mimicking the fly's hearing system was fabricated using an SOI substrate with a 25 μm device layer. The sensor consists of two 1.5 mm x1.6 mm wings connected in the middle by a 2.7 mm x 30 μm bridge. The entire structure is connected to the substrate by two torsional legs at the center. The frequency response of the sensor showed two resonance frequencies at approximately 1.1 kHz (rocking) and 1.5 kHz (bending). The resonance at 1.1 kHz is due to rocking of the wings by twisting the legs and the other at 1.5 kHz is due to bending of the bridge. The response of the sensor was probed electronically using comb finger capacitors integrated to the edges of the wings and with the help of an MS3110 chip. A peak output voltage of about 9V/Pa was measured for sound incident normal to the device at the resonance frequency of the bending mode. The bearing of the incident sound under these conditions could be determined to within a few degrees. These findings indicate the potential use of the MEMS sensor to locate sound sources with high accuracy.

  15. Radiation directivity rotation by acoustic metamaterials

    SciTech Connect

    Jiang, Xue; Liang, Bin E-mail: jccheng@nju.edu.cn; Zou, Xin-ye; Cheng, Jian-chun E-mail: jccheng@nju.edu.cn; Zhang, Likun

    2015-08-31

    We use a metamaterial-based scheme to rotate the radiation directivity of sound radiated by a source surrounded by the structure. The rotation is demonstrated through both numerical simulations and experiments. The performance persists within a broadband and is entirely independent of the location and pattern of source inside, suggesting great potential in various practical scenarios where both the signal frequency and source position may vary significantly. We have also investigated the possibility to realize versatile controls of radiation direction by tailoring the structural parameters. Our design with special directivity-steering capability may open route to loudspeaker and auditorium acoustics designs and medical ultrasound applications.

  16. Radiation directivity rotation by acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Jiang, Xue; Zhang, Likun; Liang, Bin; Zou, Xin-ye; Cheng, Jian-chun

    2015-08-01

    We use a metamaterial-based scheme to rotate the radiation directivity of sound radiated by a source surrounded by the structure. The rotation is demonstrated through both numerical simulations and experiments. The performance persists within a broadband and is entirely independent of the location and pattern of source inside, suggesting great potential in various practical scenarios where both the signal frequency and source position may vary significantly. We have also investigated the possibility to realize versatile controls of radiation direction by tailoring the structural parameters. Our design with special directivity-steering capability may open route to loudspeaker and auditorium acoustics designs and medical ultrasound applications.

  17. Using fetal acoustic stimulation to shorten the biophysical profile.

    PubMed

    Pinette, Michael G; Blackstone, Jacquelyn; Wax, Joseph R; Cartin, Angelina

    2005-06-01

    To determine whether fetal acoustic stimulation can decrease the time required to achieve a reassuring biophysical profile. Patients scheduled for a biophysical profile were prospectively assigned to study and control groups. The study group received 3 seconds of acoustic stimulation if fetal breathing, tone, or movement were not present during the first 5 minutes of the study. The biophysical profile was completed in the standard fashion, for both groups. A total of 870 patients were enrolled (458 control, 412 with stimulation). The fetal acoustic stimulation group had decreased testing time (3 minutes) and fewer non-reassuring tests (5%). The fetal acoustic stimulation group had fewer studies without breathing, potentially reducing the need for further testing or intervention. Fetal acoustic stimulation can be used to decrease the biophysical profile testing time and to reduce the number of non-reassuring tests. (c) 2005 Wiley Periodicals, Inc. J Clin Ultrasound 33:223-225, 2005.

  18. Recent applications of acoustic Doppler current profilers

    USGS Publications Warehouse

    Oberg, K.A.; Mueller, David S.

    1994-01-01

    A Broadband acoustic Doppler current profiler (BB-ADCP) is a new instrument being used by the U.S. Geological Survey (USGS) to measure stream discharge and velocities, and bathymetry. During the 1993 Mississippi River flood, more than 160 high-flow BB-ADCP measurements were made by the USGS at eight locations between Quincy and Cairo, Ill., from July 19 to August 20, 1993. A maximum discharge of 31,400 m3/s was measured at St. Louis, Mo., on August 2, 1993. A BB-ADCP also has been used to measure leakage through three control structures near Chicago, Ill. These measurements are unusual in that the average velocity for the measured section was as low as 0.03 m/s. BB-ADCP's are also used in support of studies of scour at bridges. During the recent Mississippi River flood, BB-ADCP's were used to measure water velocities and bathymetry upstream from, next to, and downstream from bridge piers at several bridges over the Mississippi River. Bathymetry data were collected by merging location data from Global Positioning System (GPS) receivers, laser tracking systems, and depths measured by the BB-ADCP. These techniques for collecting bathymetry data were used for documenting the channel formation downstream from the Miller City levee break and scour near two bridges on the Mississippi River.

  19. Assessment of a direct acoustic cochlear stimulator.

    PubMed

    Chatzimichalis, Michail; Sim, Jae Hoon; Huber, Alexander M

    2012-01-01

    This study aimed to assess the functional results of a new, active, acoustic-mechanical hearing implant, the Direct Acoustic Cochlear Stimulation Partial Implant (DACS PI), in a preclinical study. The DACS PI is an electromagnetic device fixed to the mastoid by screws and coupled to a standard stapes prosthesis by an artificial incus (AI). The function of the DACS PI-aided reconstruction was assessed by determining: (1) the maximum equivalent sound pressure level (SPL) of the implant, which was obtained from measurements of the volume displacement at the round window in normal and implanted ears, and (2) the quality at the coupling interface between the AI of the DACS and the stapes prosthesis, which was quantified from measurements of relative motions between the AI and the prosthesis. Both measurements were performed with fresh temporal bones using a scanning laser Doppler interferometry system. The expected maximum equivalent SPL with a typical driving voltage of 0.3 V was about 115-125 dB SPL up to 1.5 kHz in reconstruction with the DACS PI, and decreased with a roll-off slope of about 65 dB/decade, reaching 90 dB SPL at 8 kHz. The large roll-off relative to a normal ear was presumed to be a relatively high inductive impedance of the coil of the DACS PI actuator at higher frequencies. Good coupling quality between the AI and the prosthesis was achieved below the resonance (∼1.5 kHz) of the DACS PI for all tested stapes prostheses. Above the resonance, the SMart Piston, which is composed of a shape-memory alloy, had the best coupling quality.

  20. Reverberant Acoustic Testing and Direct Field Acoustic Testing Acoustic Standing Waves and their Impact on Structural Responses

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; Doty, Benjamin; Chang, Zensheu

    2012-01-01

    The aerospace industry has been using two methods of acoustic testing to qualify flight hardware: (1) Reverberant Acoustic Test (RAT), (2) Direct Field Acoustic Test (DFAT). The acoustic field obtained by RAT is generally understood and assumed to be diffuse, expect below Schroeder cut-of frequencies. DFAT method of testing has some distinct advantages over RAT, however the acoustic field characteristics can be strongly affected by test setup such as the speaker layouts, number and location of control microphones and control schemes. In this paper the following are discussed based on DEMO tests performed at APL and JPL: (1) Acoustic wave interference patterns and acoustic standing waves, (2) The structural responses in RAT and DFAT.

  1. Reverberant Acoustic Testing and Direct Field Acoustic Testing Acoustic Standing Waves and their Impact on Structural Responses

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; Doty, Benjamin; Chang, Zensheu

    2012-01-01

    The aerospace industry has been using two methods of acoustic testing to qualify flight hardware: (1) Reverberant Acoustic Test (RAT), (2) Direct Field Acoustic Test (DFAT). The acoustic field obtained by RAT is generally understood and assumed to be diffuse, expect below Schroeder cut-of frequencies. DFAT method of testing has some distinct advantages over RAT, however the acoustic field characteristics can be strongly affected by test setup such as the speaker layouts, number and location of control microphones and control schemes. In this paper the following are discussed based on DEMO tests performed at APL and JPL: (1) Acoustic wave interference patterns and acoustic standing waves, (2) The structural responses in RAT and DFAT.

  2. Future directions in musical acoustics education

    NASA Astrophysics Data System (ADS)

    Rossing, Thomas D.

    2005-04-01

    The desire to understand sound production by musical instruments, transmission of musical sound to the listener, and the perception of musical sound has been a strong motivator for students to learn acoustics, and will no doubt continue to be. We briefly describe past and present practices in teaching musical acoustics and attempt to predict how the subject may develop in the future.

  3. Directional Electrostatic Accretion Process Employing Acoustic Droplet Formation

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard (Inventor)

    1998-01-01

    The present invention is directed to an apparatus for manufacturing a free standing solid metal part. In the present invention, metal droplets are ejected in a nozzleless fashion from a free surface pool of molten metal by applying focused acoustic radiation pressure. The acoustic radiation pressure is produced by high intensity acoustic tone bursts emitted from an acoustic source positioned at the bottom of the pool which directs the acoustic energy at the pool surface. The metal droplets are electrostatically charged so their trajectory can be controlled by electric fields that guide the droplets to predetermined points on a target. The droplets impinge upon the target and solidify with the target material. The accretion of the electrostatically directed solidified droplets forms the free standing metal part.

  4. Acoustic temperature profile measurement technique for large combustion chambers

    NASA Technical Reports Server (NTRS)

    Venkateshan, S. P.; Shakkottai, P.; Kwack, E. Y.; Back, L. H.

    1989-01-01

    Measurement of times of flight of sound waves can be used to determine temperatures in a gas. This paper describes a system, based on this principle, that is capable of giving the temperature profile in a nonisothermal gas volume, for example, prevalent in a large furnace. The apparatus is simple, rugged, accurate, and capable of being automated for process control applications. It is basically an acoustic waveguide where the outside temperature profile is transferred to a chosen gas contained inside the guide.

  5. An Acoustic Profile of Right-Dislocations in French.

    ERIC Educational Resources Information Center

    Ashby, William J.

    1994-01-01

    Provides an acoustic profile of the prosody of right-dislocations in French, using the CECIL computer hardware and software package to analyze 28 right-dislocations occurring in a corpus of natural French discourse. It was found that, although right-dislocations appear to fulfill various functional roles in discourse, no correlation appears…

  6. Tracking beaked whales with a passive acoustic profiler float.

    PubMed

    Matsumoto, Haru; Jones, Christopher; Klinck, Holger; Mellinger, David K; Dziak, Robert P; Meinig, Christian

    2013-02-01

    Acoustic methods are frequently used to monitor endangered marine mammal species. Advantages of acoustic methods over visual ones include the ability to detect submerged animals, to work at night, and to work in any weather conditions. A relatively inexpensive and easy-to-use acoustic float, the QUEphone, was developed by converting a commercially available profiler float to a mobile platform, adding acoustic capability, and installing the ERMA cetacean click detection algorithm of Klinck and Mellinger [(2011). J. Acoust. Soc. Am. 129(4), 1807-1812] running on a high-power DSP. The QUEphone was tested at detecting Blainville's beaked whales at the Atlantic Undersea Test and Evaluation Center (AUTEC), a Navy acoustic test range in the Bahamas, in June 2010. Beaked whale were present at AUTEC, and the performance of the QUEphone was compared with the Navy's Marine Mammal Monitoring on Navy Ranges (M3R) system. The field tests provided data useful to evaluate the QUEphone's operational capability as a tool to detect beaked whales and report their presence in near-real time. The range tests demonstrated that the QUEphone's beaked whale detections were comparable to that of M3R's, and that the float is effective at detecting beaked whales.

  7. Effects of Flow Profile on Educed Acoustic Liner Impedance

    NASA Technical Reports Server (NTRS)

    Jones, Michael G.; Watson, Willie r.; Nark, Douglas M.

    2010-01-01

    This paper presents results of an investigation of the effects of shear flow profile on impedance eduction processes employed at NASA Langley. Uniform and 1-D shear-flow propagation models are used to educe the acoustic impedance of three test liners based on aeroacoustic data acquired in the Langley Grazing Flow Impedance Tube, at source levels of 130, 140 and 150 dB, and at centerline Mach numbers of 0.0, 0.3 and 0.5. A ceramic tubular, calibration liner is used to evaluate the propagation models, as this liner is expected to be insensitive to SPL, grazing flow Mach number, and flow profile effects. The propagation models are then used to investigate the effects of shear flow profile on acoustic impedances educed for two conventional perforate-over-honeycomb liners. Results achieved with the uniform-flow models follow expected trends, but those educed with the 1-D shear-flow model do not, even for the calibration liner. However, when the flow profile used with the shear-flow model is varied to increase the Mach number gradient near the wall, results computed with the shear-flow model are well matched to those achieved with the uniform-flow model. This indicates the effects of flow profile on educed acoustic liner impedance are small, but more detailed investigations of the flow field throughout the duct are needed to better understand these effects.

  8. Direct-field acoustic testing of a flight system : logistics, challenges, and results.

    SciTech Connect

    Stasiunas, Eric Carl; Gurule, David Joseph; Babuska, Vit; Skousen, Troy J.

    2010-10-01

    Before a spacecraft can be considered for launch, it must first survive environmental testing that simulates the launch environment. Typically, these simulations include vibration testing performed using an electro-dynamic shaker. For some spacecraft however, acoustic excitation may provide a more severe loading environment than base shaker excitation. Because this was the case for a Sandia Flight System, it was necessary to perform an acoustic test prior to launch in order to verify survival due to an acoustic environment. Typically, acoustic tests are performed in acoustic chambers, but because of scheduling, transportation, and cleanliness concerns, this was not possible. Instead, the test was performed as a direct field acoustic test (DFAT). This type of test consists of surrounding a test article with a wall of speakers and controlling the acoustic input using control microphones placed around the test item, with a closed-loop control system. Obtaining the desired acoustic input environment - proto-flight random noise input with an overall sound pressure level (OASPL) of 146.7 dB-with this technique presented a challenge due to several factors. An acoustic profile with this high OASPL had not knowingly been obtained using the DFAT technique prior to this test. In addition, the test was performed in a high-bay, where floor space and existing equipment constrained the speaker circle diameter. And finally, the Flight System had to be tested without contamination of the unit, which required a contamination bag enclosure of the test unit. This paper describes in detail the logistics, challenges, and results encountered while performing a high-OASPL, direct-field acoustic test on a contamination-sensitive Flight System in a high-bay environment.

  9. Shipboard acoustic profiling of upper ocean currents

    NASA Astrophysics Data System (ADS)

    Joyce, T. M.; Bitterman, D. S.; Prada, K. E.

    1982-07-01

    The ability to map the oceanic velocity field from ships would greatly enhance our ability to describe the energetics of the oceanic eddy field, to describe the structure of narrow and intense currents, and to provide some reference field for dynamic calculations of geostrophic currents. One technique that contributes toward this goal is presented. The shipboard system consists of a microprocessor-controlled data logger that collects and formats data from a four-beam Ametek-Straza 300-kHz Doppler current profiler, heading from the ship's gyrocompass, and navigation information from a LORAN-C receiver and a satellite navigation unit. Data are recorded on magnetic tape and some real-time calculations are made. The system was used in a May 1981 cruise on R.V. Oceanus in the western North Atlantic and some 10-min, vector-averaged current profiles have been presented on a section across the Gulf Stream. Horizontal currents have been profiled to depths of 100 m. Time averaging is required to remove effects of ship motion. Errors in our ability to profile ocean currents while underway are estimated to be 5 to 10 cm s -1 for absolute currents and 1 to 2 cm s -1 for relative changes in a 10-min vector average.

  10. Nanoliter droplet coalescence in air by directional acoustic ejection

    NASA Astrophysics Data System (ADS)

    Lee, Chuang-Yuan; Yu, Hongyu; Kim, Eun Sok

    2006-11-01

    This letter presents a controlled coalescence of nanoliter liquid droplets in air by acoustic directional ejections. An asymmetrical electric field is created within a piezoelectric transducer to produce lopsided acoustic waves, which are focused (through a lens based on the innate impedance mismatch between solid and gas) onto a spot on the liquid surface. The focused acoustic beam is shown to obliquely eject 80-μm-diameter droplets at a traveling speed of 2.3m/s. Up to four such obliquely ejected droplets coalesce in air into a single droplet, which then continue to travel, rotating at 16000rad/s and producing effective micromixing in air.

  11. Acoustic reflectometry esophageal profiles minimally affected by massive gas ventilation.

    PubMed

    Raphael, David T; Crookes, Peter; Arnaudov, Dimiter; Benbassat, Maxim

    2005-10-01

    Acoustic reflectometry can be used to distinguish between breathing tube placement in an esophagus vs the trachea via characteristic area-distance profiles for both cavities. In the cardiopulmonary resuscitation setting, capnography may be useless because the patient has little or no pulmonary circulation. With the breathing tube in the esophagus, can massive ventilation with a manual resuscitation bag, as might occur in the cardiopulmonary resuscitation setting, markedly alter the form of the obtained esophageal reflectometry profile? Nine hounds were induced, endotracheally intubated, mechanically ventilated, and anesthetized. Area-distance profiles were obtained with a 2-microphone acoustic reflectometer customized to measure areas up to 50 cm. Acoustic reflectometer profiles were obtained in intubated esophagi as follows: (1) baseline nonventilated state, (2) after aggressive 2-handed manual ventilation with high inspiratory pressures, rapid respiratory rates, and large tidal volumes for periods of 0.5, 1, and 1.5 minutes, upon detachment of the resuscitation bag, and (3) after esophagogastric decompression. We hypothesized that massive gas ventilation has no effect on the esophageal peak areas (null hypothesis), and used a paired t test for statistical significance (P < .05). For times of 0.5, 1.0, and 1.5 minutes, the ventilation volumes (mean +/- SD) were 25 +/- 7, 49 +/- 8, and 70 +/- 18 L. Massive gas ventilation caused minimal broadening and slight distal spread of the basal "hump". The mean peak area change was 0.18 +/- 0.35 cm2. For a paired t test (n = 9, df = 8), the corresponding t value was 1.54, with a P value of .16, which was incompatible with the null hypothesis. The experimental observations indicate a minimal effect of massive gas ventilation on the acoustic reflectometry esophageal profile. Hence, operator recognition of the altered canine acoustic reflectometer profile as that of an esophageal cavity is maintained, indicating that acoustic

  12. Seabed classification from acoustic profiling data using the similarity index.

    PubMed

    Kim, Han-Joon; Chang, Jae-Kyeong; Jou, Hyeong-Tae; Park, Gun-Tae; Suk, Bong-Chool; Kim, Ki Young

    2002-02-01

    We introduce the similarity index (SI) for the classification of the sea floor from acoustic profiling data. The essential part of our approach is the singular value decomposition of the data to extract a signal coherent trace-to-trace using the Karhunen-Loeve transform. SI is defined as the percentage of the energy of the coherent part contained in the bottom return signals. Important aspects of SI are that it is easily computed and that it represents the textural roughness of the sea floor as a function of grain size, hardness, and a degree of sediment sorting. In a real data example, we classified a section of the sea floor off Cheju Island south of the Korean Peninsula and compared the result with the sedimentology defined from direct sediment sampling and side scan sonar records. The comparison shows that SI can efficiently discriminate the bottom properties by delineating sediment-type boundaries and transition zones in more detail. Therefore, we propose that SI is an effective parameter for geoacoustic modeling.

  13. Directional electrostatic accretion process employing acoustic droplet formation

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C. (Inventor)

    1996-01-01

    The present invention is directed to an apparatus for manufacturing a free standing solid metal part. In the present invention metal droplets are produced from a free surface pool of molten metal is when an acoustic wave impacts an acoustic lens that is contiguous with the free standing pool of molten metal. The metal droplets are then charged and deflected toward a target. The build up of the metal droplets combine to form the free standing solid metal part.

  14. Direct formulation of the supersonic acoustic intensity in space domain.

    PubMed

    Fernandez-Grande, Efren; Jacobsen, Finn; Leclère, Quentin

    2012-01-01

    This paper proposes and examines a direct formulation in space domain of the so-called supersonic acoustic intensity. This quantity differs from the usual (active) intensity by excluding the circulating energy in the near-field of the source, providing a map of the acoustic energy that is radiated into the far field. To date, its calculation has been formulated in the wave number domain, filtering out the evanescent waves outside the radiation circle and reconstructing the acoustic field with only the propagating waves. In this study, the supersonic intensity is calculated directly in space domain by means of a two-dimensional convolution between the acoustic field and a spatial filter mask that corresponds to the space domain representation of the radiation circle. Therefore, the acoustic field that propagates effectively to the far field is calculated via direct filtering in space domain. This paper presents the theory, as well as a numerical example to illustrate some fundamental principles. An experimental study on planar radiators was conducted to verify the validity of the technique. The experimental results are presented, and serve to illustrate the usefulness of the analysis, its strengths and limitations. © 2012 Acoustical Society of America.

  15. Dictionary learning of acoustic sound speed profiles

    NASA Astrophysics Data System (ADS)

    Bianco, Michael J.; Gerstoft, Peter

    2016-10-01

    To provide constraints on their inversion, ocean sound speed profiles (SSPs) often are modeled using empirical orthogonal functions (EOFs). However, this regularization, which uses the leading order EOFs with a minimum-energy constraint on their coefficients, often yields low resolution SSP estimates. In this paper, it is shown that dictionary learning, a form of unsupervised machine learning, can improve SSP resolution by generating a dictionary of shape functions for sparse processing (e.g. compressive sensing) that optimally compress SSPs; both minimizing the reconstruction error and the number of coefficients. These learned dictionaries (LDs) are not constrained to be orthogonal and thus, fit the given signals such that each signal example is approximated using few LD entries. Here, LDs describing SSP observations from the HF-97 experiment and the South China Sea are generated using the K-SVD algorithm. These LDs better explain SSP variability and require fewer coefficients than EOFs, describing much of the variability with one coefficient. Thus, LDs improve the resolution of SSP estimates with negligible computational burden.

  16. Bio-Inspired Micromechanical Directional Acoustic Sensor

    NASA Astrophysics Data System (ADS)

    Swan, William; Alves, Fabio; Karunasiri, Gamani

    Conventional directional sound sensors employ an array of spatially separated microphones and the direction is determined using arrival times and amplitudes. In nature, insects such as the Ormia ochracea fly can determine the direction of sound using a hearing organ much smaller than the wavelength of sound it detects. The fly's eardrums are mechanically coupled, only separated by about 1 mm, and have remarkable directional sensitivity. A micromechanical sensor based on the fly's hearing system was designed and fabricated on a silicon on insulator (SOI) substrate using MEMS technology. The sensor consists of two 1 mm2 wings connected using a bridge and to the substrate using two torsional legs. The dimensions of the sensor and material stiffness determine the frequency response of the sensor. The vibration of the wings in response to incident sound at the bending resonance was measured using a laser vibrometer and found to be about 1 μm/Pa. The electronic response of the sensor to sound was measured using integrated comb finger capacitors and found to be about 25 V/Pa. The fabricated sensors showed good directional sensitivity. In this talk, the design, fabrication and characteristics of the directional sound sensor will be described. Supported by ONR and TDSI.

  17. Tracking sperm whale (Physeter macrocephalus) dive profiles using a towed passive acoustic array

    NASA Astrophysics Data System (ADS)

    Thode, Aaron

    2004-07-01

    A passive acoustic method is presented for tracking sperm whale dive profiles, using two or three hydrophones deployed as either a vertical or large-aperture towed array. The relative arrival times between the direct and surface-reflected acoustic paths are used to obtain the ranges and depths of animals with respect to the array, provided that the hydrophone depths are independently measured. Besides reducing the number of hydrophones required, exploiting surface reflections simplifies automation of the data processing. Experimental results are shown from 2002 and 2003 cruises in the Gulf of Mexico for two different towed array deployments. The 2002 deployment consisted of two short-aperture towed arrays separated by 170 m, while the 2003 deployment placed an autonomous acoustic recorder in tandem with a short-aperture towed array, and used ship noise to time-align the acoustic data. The resulting dive profiles were independently checked using single-hydrophone localizations, whenever multipath reflections from the ocean bottom could be exploited to effectively create a large-aperture vertical array. This technique may have applications for basic research and for real-time mitigation for seismic airgun surveys.

  18. Data Quality Control for Vessel Mounted Acoustic Doppler Current Profiler. Application for the Western Mediterranean Sea

    NASA Technical Reports Server (NTRS)

    Garcia-Gorriz, E.; Front, J.; Candela, J.

    1997-01-01

    A systematic Data Quality Checking Protocol for vessel Mounted Acoustic Doppler Current Profiler observations is proposed. Previous-to-acquisition conditions are considered along with simultaneous ones.

  19. Data Quality Control for Vessel Mounted Acoustic Doppler Current Profiler. Application for the Western Mediterranean Sea

    NASA Technical Reports Server (NTRS)

    Garcia-Gorriz, E.; Front, J.; Candela, J.

    1997-01-01

    A systematic Data Quality Checking Protocol for vessel Mounted Acoustic Doppler Current Profiler observations is proposed. Previous-to-acquisition conditions are considered along with simultaneous ones.

  20. Micromachined silicon acoustic delay line with improved structural stability and acoustic directivity for real-time photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Cho, Young; Kumar, Akhil; Xu, Song; Zou, Jun

    2017-03-01

    Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. However, as its length increases to provide longer delay time, the delay line becomes more vulnerable to structural instability due to reduced mechanical stiffness. In addition, the small cross-section area of the delay line results in a large acoustic acceptance angle and therefore poor directivity. To address these two issues, this paper reports the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, a new tapered design for the input terminal of the delay line was also investigate to improve its acoustic directivity by reducing the acoustic acceptance angle. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

  1. Acoustic analysis of dysarthria profile in ALS patients.

    PubMed

    Tomik, B; Krupinski, J; Glodzik-Sobanska, L; Bala-Slodowska, M; Wszolek, W; Kusiak, M; Lechwacka, A

    1999-10-31

    Dysarthria is a leading disability in ALS patients with motor neurone degeneration in the bulbar region. Although different approaches have been tried in the past, currently, no test is available to detect and follow the progression of dysarthria. We studied 53 patients with definite (n=27) or probable (n=26) ALS (the bulbar onset group n=15, the limb onset group n=38, mean age 53. 66/29-76 years/) according to El Escorial criteria. Each patient was seen by a neurologist every 10-12 weeks and clinical performance was assessed using the Norris scale. To evaluate dysarthria we developed a computer-based acoustic method. All patients had computer-analysed speech sound tests done three times. The most significantly affected vowels were selected for further studies. A method based on the Euclidian principle was used and the results were compared with 30 age, sex-matched, healthy control subjects. Our results demonstrated the existence of a specific dysarthria profile in ALS patients with most significantly affected vowels: 'B', 'O', 'I', 'W', 'T' in the bulbar group, and: 'B', 'I', 'T', 'W', 'O' in the limb group. This study suggests that it is possible to detect and monitor the progression of the disease based on the acoustic analysis of only several sounds. Abnormalities detected in the dysarthria profile may appear prior to any clinical symptoms of the disease.

  2. Distribution theory approach to implementing directional acoustic sensors.

    PubMed

    Schmidlin, Dean J

    2010-01-01

    The objective of directional acoustic sensors is to provide high directivity while occupying a small amount of space. An idealized point sensor achieves this objective from a knowledge of the spatial partial derivatives of acoustic pressure at a point in space. Direct measurement of these derivatives is difficult in practice. Consequently, it is expedient to come up with indirect methods. The use of pressure sensors to construct finite-difference approximations is an example of such a method. This paper utilizes the theory of distributions to derive another indirect method for estimating the various spatial partial derivatives of the pressure. This alternate method is then used to construct a multichannel filter which processes the acoustic pressure by mean of three-dimensional integral transforms throughout a 6epsilon-length cube centered at the origin. The output of the multichannel filter is a spatially and temporally filtered version of the pressure at the origin. The temporal filter is a lowpass Gaussian filter whose bandwidth is inversely proportional to epsilon. Finally, the lattice method for numerical multiple integration is utilized to develop a discrete-spatial version of the multichannel filter.

  3. Validation of streamflow measurements made with acoustic doppler current profilers

    USGS Publications Warehouse

    Oberg, K.; Mueller, D.S.

    2007-01-01

    The U.S. Geological Survey and other international agencies have collaborated to conduct laboratory and field validations of acoustic Doppler current profiler (ADCP) measurements of streamflow. Laboratory validations made in a large towing basin show that the mean differences between tow cart velocity and ADCP bottom-track and water-track velocities were -0.51 and -1.10%, respectively. Field validations of commercially available ADCPs were conducted by comparing streamflow measurements made with ADCPs to reference streamflow measurements obtained from concurrent mechanical current-meter measurements, stable rating curves, salt-dilution measurements, or acoustic velocity meters. Data from 1,032 transects, comprising 100 discharge measurements, were analyzed from 22 sites in the United States, Canada, Sweden, and The Netherlands. Results of these analyses show that broadband ADCP streamflow measurements are unbiased when compared to the reference discharges regardless of the water mode used for making the measurement. Measurement duration is more important than the number of transects for reducing the uncertainty of the ADCP streamflow measurement. ?? 2007 ASCE.

  4. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator

    PubMed Central

    Luo, Chuan; Omelchenko, Irina; Manson, Robert; Robbins, Carol; Oesterle, Elizabeth C.; Cao, Guo Zhong; Hume, Clifford R.

    2015-01-01

    Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT). This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR) thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays. PMID:26631107

  5. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator.

    PubMed

    Luo, Chuan; Omelchenko, Irina; Manson, Robert; Robbins, Carol; Oesterle, Elizabeth C; Cao, Guo Zhong; Shen, I Y; Hume, Clifford R

    2015-12-01

    Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT). This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR) thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays.

  6. A thin and conformal metasurface for illusion acoustics of rapidly changing profiles

    NASA Astrophysics Data System (ADS)

    Dubois, Marc; Shi, Chengzhi; Wang, Yuan; Zhang, Xiang

    2017-04-01

    Recently developed metasurfaces have been used for surface engineering applications. However, the ability to cloak or mimic reflective surfaces with a large in-plane phase gradient remains unexplored. One major challenge is that even with a small incidence angle, the strong acoustic impedance variation induced by the random height profile creates additional scattering and increases the complexity of the analysis and design of the metasurface. Here, we introduce an acoustic metasurface with 1/12 wavelength thickness to realize an acoustic carpet cloak for a randomly rapid-change surface and a virtual acoustic diffuser from a flat surface using a set of Helmholtz resonators. The limitation of the metasurface for large phase gradient application is explored based on a nonlocal model that considers the contributions from neighboring surface profiles. This study extends the integration of smart acoustic surface and may find applications of surface engineering such as in architectural acoustics.

  7. Measurement resolution of noise directivity patterns from acoustic flight tests

    NASA Technical Reports Server (NTRS)

    Conner, David A.

    1989-01-01

    The measurement resolution of noise directivity patterns from acoustic flight tests was investigated. Directivity angle resolution is affected by the data reduction parameters, the aircraft velocity and flyover altitude, and by deviations of the aircraft from the desired flight path. Equations are developed which determine bounds for the lateral and longitudinal directivity angle resolution as a function of the nominal directivity angle. The equations are applied to a flight test data base and the effects of several flight conditions and data reduction parameters on the directivity angle resolution are presented. The maximum directivity angle resolution typically occurs when the aircraft is at or near the overhead position. In general, directivity angle resolution improves with decreasing velocity, increasing altitude, increasing sampling rate, decreasing block size, and decreasing block averages. Deviations from the desired ideal flight path will increase the resolution. For the flight experiment considered in this study, an average of two flyovers were required at each test condition to obtain an acceptable flight path. The ability of the pilot to maintain the flight track improved with decreasing altitude, decreasing velocity, and practice. Due to the prevailing wind conditions, yaw angles of as much as 20 deg were required to maintain the desired flight path.

  8. Aerodynamic and directional acoustic performance of a scoop inlet

    NASA Technical Reports Server (NTRS)

    Abbott, J. M.; Dietrich, D. A.

    1977-01-01

    Aerodynamic and directional acoustic performances of a scoop inlet were studied. The scoop inlet is designed with a portion of the lower cowling extended forward to direct upward any noise that is propagating out the front of the engine toward the ground. The tests were conducted in an anechoic wind tunnel facility at free stream velocities of 0, 18, 41, and 61 m/sec and angles of attack from -10 deg to 120 deg. Inlet throat Mach number was varied from 0.30 to 0.75. Aerodynamically, at a free stream velocity of 41 m/sec, the design throat Mach number (0.63), and an angle of attack of 50 deg, the scoop inlet total pressure recovery was 0.989 and the total pressure distortion was 0.15. The angles of attack where flow separation occurred with the scoop inlet were higher than those for a conventional symmetric inlet. Acoustically, the scoop inlet provided a maximum noise reduction of 12 to 15 db below the inlet over the entire range of throat Mach number and angle of attack at a free-stream velocity of 41 m/sec.

  9. Structural acoustics model of the violin radiativity profile.

    PubMed

    Bissinger, George

    2008-12-01

    Violin radiativity profiles are dominated by the Helmholtz-like A0 cavity mode ( approximately 280 Hz), first corpus bending modes B1(-) and B1(+) ( approximately 500 Hz), and BH and bridge-filter peaks ( approximately 2.4 kHz and approximately 3.5 kHz, respectively), with falloff above approximately 4 kHz. The B1 modes-dependent on two low-lying free-plate modes--are proposed to excite A0 via coupling to B1-driven in-phase f-hole volume flows. VIOCADEAS data show that A0 radiativity increases primarily as A0-B1(-) frequency difference decreases, consistent with Meinel's 1937 experiment for too-thick/too-thin plate thicknesses, plus sound post removal and violin octet baritone results. The vibration-->acoustic energy filter, F(RAD), computed from shape-material-independent radiation and total damping, peaks at the critical frequency f(crit), estimated from a free-plate mode by analogy to flat-plate bending. Experimentally, f(crit) decreased as this plate mode (and B1(+)) frequency increased. Simulations show that increasing plate thicknesses lowers f(crit), reduces F(RAD), and moves the spectral balance toward lower frequencies. Incorporating string-->corpus filters (including bridge versus bridge-island impedances) provides a model for overall violin radiativity. This model-with B1 and A0-B1 couplings, and f(crit) (computed from a free-plate mode important to B1) strongly affecting the lowest and highest parts of the radiativity profile-substantiates prior empirical B1--sound quality linkages.

  10. River Bed Sediment Classification Using Acoustic Doppler Profiler

    NASA Astrophysics Data System (ADS)

    Shields, F. D.

    2008-12-01

    Restoration or rehabilitation of degraded stream and river habitats requires definition of a target condition and preferably post-implementation monitoring to gage progress toward the target. Stream habitat has been characterized by computing statistics based on measurements of water depth and velocity at each point of a horizontal grid. In many cases stream bed type and cover, both qualitatively assessed, were included as additional grid variables. Resultant statistics describing the central tendency, variability and spatial distribution of these three or four variables and their combinations have been used to explain key differences between more- and less-degraded streams and to infer biotic responses. Usually the required data are collected by wading observers, but application to larger rivers is problematic. Collection of water depth and velocity information may be automated across a wide range of stream sizes using an acoustic Doppler profiler (aDp). Herein we suggest that aDp data may also be used to infer bed hardness and thus type by extracting the return signal strength from the bottom track signal and using this information to compute the echo intensity at the bed. A method for computing echo intensity, along with key assumptions is presented. Echo intensity is computed for a range of river environments and related to the size and related characteristics of bed material. Habitat maps for river reaches depicting water depth, velocity and bed type developed from aDp data sets are presented.

  11. Acoustic profiles of distinct emotional expressions in laughter.

    PubMed

    Szameitat, Diana P; Alter, Kai; Szameitat, André J; Wildgruber, Dirk; Sterr, Annette; Darwin, Chris J

    2009-07-01

    Although listeners are able to decode the underlying emotions embedded in acoustical laughter sounds, little is known about the acoustical cues that differentiate between the emotions. This study investigated the acoustical correlates of laughter expressing four different emotions: joy, tickling, taunting, and schadenfreude. Analysis of 43 acoustic parameters showed that the four emotions could be accurately discriminated on the basis of a small parameter set. Vowel quality contributed only minimally to emotional differentiation whereas prosodic parameters were more effective. Emotions are expressed by similar prosodic parameters in both laughter and speech.

  12. Acoustic Doppler Current Profiler Surveys of Velocity Downstream of Albeni Falls Dam

    SciTech Connect

    Perkins, William A.; Titzler, P. Scott; Richmond, Marshall C.; Serkowski, John A.; Kallio, Sara E.; Bellgraph, Brian J.

    2010-09-30

    The U.S. Army Corps of Engineers (USACE), Seattle District, is studying the potential to locate fish bypass systems at Albeni Falls Dam. The USACE requested Pacific Northwest National Laboratory (PNNL) to survey velocity magnitude and direction in the dam tailrace. The empirical data collected will be used to support future numerical modeling, physical modeling, and evaluation of fish bypass system alternatives. In May 2010, PNNL conducted velocity surveys of the Albeni Falls Dam using a boat-mounted acoustic Doppler current profiler. The surveys were conducted over three days (May 25 through 27). During the survey period, total river discharge at the dam varied between 30.2 and 31.0 kcfs. A small amount of spill discharge, 2 kcfs, was present on two days (May 26 and 27). This report presents data plots showing measured velocity direction and magnitude averaged over the entire depth and over 5-ft depth increments from 5 to 30 ft.

  13. Automated acoustic intensity measurements and the effect of gear tooth profile on noise

    NASA Technical Reports Server (NTRS)

    Atherton, William J.; Pintz, Adam; Lewicki, David G.

    1987-01-01

    Acoustic intensity measurements were made at NASA Lewis Research Center on a spur gear test apparatus. The measurements were obtained with the Robotic Acoustic Intensity Measurement System developed by Cleveland State University. This system provided dense spatial positioning, and was calibrated against a high quality acoustic intensity system. The measured gear noise compared gearsets having two different tooth profiles. The tests evaluated the sound field of the different gears for two speeds and three loads. The experimental results showed that gear tooth profile had a major effect on measured noise. Load and speed were found to have an effect on noise also.

  14. Direct visualization of surface acoustic waves along substrates using smoke particles

    NASA Astrophysics Data System (ADS)

    Tan, Ming K.; Friend, James R.; Yeo, Leslie Y.

    2007-11-01

    Smoke particles (SPs) are used to directly visualize surface acoustic waves (SAWs) propagating on a 128°-rotated Y-cut X-propagating lithium niobate (LiNbO3) substrate. By electrically exciting a SAW device in a compartment filled with SP, the SP were found to collect along the regions where the SAW propagates on the substrate. The results of the experiments show that SPs are deposited adjacent to regions of large vibration amplitude and form a clear pattern corresponding to the surface wave profile on the substrate. Through an analysis of the SAW-induced acoustic streaming in the air adjacent to the substrate and the surface acceleration measured with a laser Doppler vibrometer, we postulate that the large transverse surface accelerations due to the SAW ejects SP from the surface and carries them aloft to relatively quiescent regions nearby via acoustic streaming. Offering finer detail than fine powders common in Chladni figures [E. Chladni, Entdeckungen über die Theorie des Klanges (Weidmanns, Erben und Reich, Leipzig, Germany, 1787)] the approach is an inexpensive and a quick counterpart to laser interferometric techniques, presenting a means to explore the controversial phenomena of particle agglomeration on surfaces.

  15. Deep-Water Ambient Noise Profiling; Marine Sediment Acoustics; and Doppler Geo-Acoustic Spectroscopy

    DTIC Science & Technology

    2013-09-30

    acoustic propagation models. He is using my analytical models10, 11 of the penetrable wedge and the conical seamount , both developed many years ago...propagation around a conical seamount ", J. Acoust. Soc. Am. 80, 265-277 (1986). 12. M. J. Buckingham and E. M. Giddens, "Theory of sound propagation from a

  16. Deep-Water Ambient Noise Profiling; Marine Sediment Acoustics; and Doppler Geo-Acoustic Spectroscopy

    DTIC Science & Technology

    2012-09-30

    conical seamount for comparison with his numerical results. A conference was held recently on “Basic Science and the Future Warfighter” [ASD(R&E...M. J. Buckingham, “Theory of acoustic propagation around a conical seamount ”, J. Acoust. Soc. Am., 80, 265-277 (1986) 12. M. J. Buckingham and E

  17. Broadband Field Directionally Mapping using Maneuverable Acoustic Sensor Arrays

    DTIC Science & Technology

    2015-09-30

    Maneuverable Acoustic Sensor Arrays David Smith Dept. of Electrical and Computer Engineering Duke University, Box 90291 Durham, NC 27708 phone: (919) 660... acoustic arrays to resolve targets from interferers, and 2) improve the target detection, localization, and tracking performance of long arrays during tow...splines) EM algorithm. Both algorithms were run using a simulated 30 element acoustic vector sensor array with 900 snapshots. Attention has also

  18. System and Method for Calculating the Directivity Index of a Passive Acoustic Array

    DTIC Science & Technology

    2007-07-27

    DIRECTIVITY INDEX OF A PASSIVE ACOUSTIC ARRAY STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and used by or...directed to a system and method for calculating the directivity index of a passive acoustic array with directional sensors in an isotropic noise field...and to provide an efficient way to create, modify, and model any array geometry for the purposes of determining the directivity index of the array as

  19. The direct simulation of acoustics on Earth, Mars, and Titan.

    PubMed

    Hanford, Amanda D; Long, Lyle N

    2009-02-01

    With the recent success of the Huygens lander on Titan, a moon of Saturn, there has been renewed interest in further exploring the acoustic environments of the other planets in the solar system. The direct simulation Monte Carlo (DSMC) method is used here for modeling sound propagation in the atmospheres of Earth, Mars, and Titan at a variety of altitudes above the surface. DSMC is a particle method that describes gas dynamics through direct physical modeling of particle motions and collisions. The validity of DSMC for the entire range of Knudsen numbers (Kn), where Kn is defined as the mean free path divided by the wavelength, allows for the exploration of sound propagation in planetary environments for all values of Kn. DSMC results at a variety of altitudes on Earth, Mars, and Titan including the details of nonlinearity, absorption, dispersion, and molecular relaxation in gas mixtures are given for a wide range of Kn showing agreement with various continuum theories at low Kn and deviation from continuum theory at high Kn. Despite large computation time and memory requirements, DSMC is the method best suited to study high altitude effects or where continuum theory is not valid.

  20. Acoustical Direction Finding with Time-Modulated Arrays

    PubMed Central

    Clark, Ben; Flint, James A.

    2016-01-01

    Time-Modulated Linear Arrays (TMLAs) offer useful efficiency savings over conventional phased arrays when applied in parameter estimation applications. The present paper considers the application of TMLAs to acoustic systems and proposes an algorithm for efficiently deriving the arrival angle of a signal. The proposed technique is applied in the frequency domain, where the signal and harmonic content is captured. Using a weighted average method on harmonic amplitudes and their respective main beam angles, it is possible to determine an estimate for the signal’s direction of arrival. The method is demonstrated and evaluated using results from both numerical and practical implementations and performance data is provided. The use of Micro-Electromechanical Systems (MEMS) sensors allows time-modulation techniques to be applied at ultrasonic frequencies. Theoretical predictions for an array of five isotropic elements with half-wavelength spacing and 1000 data samples suggest an accuracy of ±1∘ within an angular range of approximately ±50∘. In experiments of a 40 kHz five-element microphone array, a Direction of Arrival (DoA) estimation within ±2.5∘ of the target signal is readily achieved inside a ±45∘ range using a single switched input stage and a simple hardware setup. PMID:27973432

  1. Acoustical Direction Finding with Time-Modulated Arrays.

    PubMed

    Clark, Ben; Flint, James A

    2016-12-11

    Time-Modulated Linear Arrays (TMLAs) offer useful efficiency savings over conventional phased arrays when applied in parameter estimation applications. The present paper considers the application of TMLAs to acoustic systems and proposes an algorithm for efficiently deriving the arrival angle of a signal. The proposed technique is applied in the frequency domain, where the signal and harmonic content is captured. Using a weighted average method on harmonic amplitudes and their respective main beam angles, it is possible to determine an estimate for the signal's direction of arrival. The method is demonstrated and evaluated using results from both numerical and practical implementations and performance data is provided. The use of Micro-Electromechanical Systems (MEMS) sensors allows time-modulation techniques to be applied at ultrasonic frequencies. Theoretical predictions for an array of five isotropic elements with half-wavelength spacing and 1000 data samples suggest an accuracy of ± 1 ∘ within an angular range of approximately ± 50 ∘ . In experiments of a 40 kHz five-element microphone array, a Direction of Arrival (DoA) estimation within ± 2 . 5 ∘ of the target signal is readily achieved inside a ± 45 ∘ range using a single switched input stage and a simple hardware setup.

  2. Accuracy of a pulse-coherent acoustic Doppler profiler in a wave-dominated flow

    USGS Publications Warehouse

    Lacy, J.R.; Sherwood, C.R.

    2004-01-01

    The accuracy of velocities measured by a pulse-coherent acoustic Doppler profiler (PCADP) in the bottom boundary layer of a wave-dominated inner-shelf environment is evaluated. The downward-looking PCADP measured velocities in eight 10-cm cells at 1 Hz. Velocities measured by the PCADP are compared to those measured by an acoustic Doppler velocimeter for wave orbital velocities up to 95 cm s-1 and currents up to 40 cm s-1. An algorithm for correcting ambiguity errors using the resolution velocities was developed. Instrument bias, measured as the average error in burst mean speed, is -0.4 cm s-1 (standard deviation = 0.8). The accuracy (root-mean-square error) of instantaneous velocities has a mean of 8.6 cm s-1 (standard deviation = 6.5) for eastward velocities (the predominant direction of waves), 6.5 cm s-1 (standard deviation = 4.4) for northward velocities, and 2.4 cm s-1 (standard deviation = 1.6) for vertical velocities. Both burst mean and root-mean-square errors are greater for bursts with ub ??? 50 cm s-1. Profiles of burst mean speeds from the bottom five cells were fit to logarithmic curves: 92% of bursts with mean speed ??? 5 cm s-1 have a correlation coefficient R2 > 0.96. In cells close to the transducer, instantaneous velocities are noisy, burst mean velocities are biased low, and bottom orbital velocities are biased high. With adequate blanking distances for both the profile and resolution velocities, the PCADP provides sufficient accuracy to measure velocities in the bottom boundary layer under moderately energetic inner-shelf conditions.

  3. Characterization of guided acoustic waves in an arbitrary direction with full-field instantaneous maps of the acoustic displacement

    NASA Astrophysics Data System (ADS)

    Luís Deán-Ben, X.; Trillo, Cristina; Doval, Ángel F.; Fernández, José L.

    2012-08-01

    The full-field optical measurement of guided acoustic waves presents important advantages derived from the capability to map the acoustic field in a two dimensional region, so that acoustic information over a large area can be retrieved with each measurement. In this work, we introduce an extension of the well-established two dimensional spatio-temporal Fourier transform method to calculate the frequency spectrum of guided acoustic waves. For this, we take advantage of the unique capability of a self-developed double-pulsed television holography system to acquire the acoustic displacement field in two spatial dimensions and time. Then, the spatio-temporal Fourier transform method is expanded to three dimensions according to the nature of the experimental data, so that the frequency spectrum of the waves propagating in an arbitrary direction can be calculated. The method is tested experimentally by generating narrowband Lamb waves in an aluminium plate with a piezoelectric transducer. The good agreement between the theoretical and experimental spectra in a broad zone anticipates the applicability of the method to characterize guided acoustic waves as a function of the propagation direction in materials or structures presenting anisotropic propagation behaviour.

  4. A PARALIND Decomposition-Based Coherent Two-Dimensional Direction of Arrival Estimation Algorithm for Acoustic Vector-Sensor Arrays

    PubMed Central

    Zhang, Xiaofei; Zhou, Min; Li, Jianfeng

    2013-01-01

    In this paper, we combine the acoustic vector-sensor array parameter estimation problem with the parallel profiles with linear dependencies (PARALIND) model, which was originally applied to biology and chemistry. Exploiting the PARALIND decomposition approach, we propose a blind coherent two-dimensional direction of arrival (2D-DOA) estimation algorithm for arbitrarily spaced acoustic vector-sensor arrays subject to unknown locations. The proposed algorithm works well to achieve automatically paired azimuth and elevation angles for coherent and incoherent angle estimation of acoustic vector-sensor arrays, as well as the paired correlated matrix of the sources. Our algorithm, in contrast with conventional coherent angle estimation algorithms such as the forward backward spatial smoothing (FBSS) estimation of signal parameters via rotational invariance technique (ESPRIT) algorithm, not only has much better angle estimation performance, even for closely-spaced sources, but is also available for arbitrary arrays. Simulation results verify the effectiveness of our algorithm. PMID:23604030

  5. Realization of acoustic wave directivity at low frequencies with a subwavelength Mie resonant structure

    NASA Astrophysics Data System (ADS)

    Lu, Gengxi; Ding, Erliang; Wang, Yangyang; Peng, Xiuyuan; Cui, Jun; Liu, Xiaozhou; Liu, Xiaojun

    2017-03-01

    We realized high-efficiency acoustic directivity at low frequencies based on monopolar Mie resonance. This is caused by micro structures that have a high refractive index relative to the background medium. The structures can strongly control the radiation pattern though the acoustic wavelength is much larger than its dimensions. We herein discuss how to enhance the directivity through modifying the structure's parameters. Furthermore, our structure is proposed for use in obtaining an acoustic collimated beam without sidelobes. The structure characteristics and applications are demonstrated both theoretically and experimentally. Potential applications of our structures include acoustic device miniaturization, noise control, and medical ultrasonics.

  6. Proceedings of the Workshop on Directional Acoustic Sensors Held in Newport, Rhode Island on 17-18 April 2001

    DTIC Science & Technology

    2001-04-18

    Corporation EDO Directional Acoustic Sensor Technology Dr. Bruce Abraham, Anteon Corporation Directional Hydrophones in Towed System 01... EDO Directional Acoustic Sensor Technology P. David Baird Systems Engineering Department EDO Electro-Ceramics Products...Salt Lake City, Utah 84115 1 EDO Directional Acoustic Sensor Technology P. David Baird Systems Engineering Department EDO Electro

  7. Impact of Acoustic Standing Waves on Structural Responses: Reverberant Acoustic Testing (RAT) vs. Direct Field Acoustic Testing (DFAT)

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; Doty, Benjamin; Chang, Zensheu

    2012-01-01

    Loudspeakers have been used for acoustic qualification of spacecraft, reflectors, solar panels, and other acoustically responsive structures for more than a decade. Limited measurements from some of the recent speaker tests used to qualify flight hardware have indicated significant spatial variation of the acoustic field within the test volume. Also structural responses have been reported to differ when similar tests were performed using reverberant chambers. To address the impact of non-uniform acoustic field on structural responses, a series of acoustic tests were performed using a flat panel and a 3-ft cylinder exposed to the field controlled by speakers and repeated in a reverberant chamber. The speaker testing was performed using multi-input-single-output (MISO) and multi-input-multi-output (MIMO) control schemes with and without the test articles. In this paper the spatial variation of the acoustic field due to acoustic standing waves and their impacts on the structural responses in RAT and DFAT (both using MISO and MIMO controls for DFAT) are discussed in some detail.

  8. Impact of Acoustic Standing Waves on Structural Responses: Reverberant Acoustic Testing (RAT) vs. Direct Field Acoustic Testing (DFAT)

    NASA Technical Reports Server (NTRS)

    Kolaini, Ali R.; Doty, Benjamin; Chang, Zensheu

    2012-01-01

    Loudspeakers have been used for acoustic qualification of spacecraft, reflectors, solar panels, and other acoustically responsive structures for more than a decade. Limited measurements from some of the recent speaker tests used to qualify flight hardware have indicated significant spatial variation of the acoustic field within the test volume. Also structural responses have been reported to differ when similar tests were performed using reverberant chambers. To address the impact of non-uniform acoustic field on structural responses, a series of acoustic tests were performed using a flat panel and a 3-ft cylinder exposed to the field controlled by speakers and repeated in a reverberant chamber. The speaker testing was performed using multi-input-single-output (MISO) and multi-input-multi-output (MIMO) control schemes with and without the test articles. In this paper the spatial variation of the acoustic field due to acoustic standing waves and their impacts on the structural responses in RAT and DFAT (both using MISO and MIMO controls for DFAT) are discussed in some detail.

  9. Profile of Laser-Produced Acoustic Pulse in a Liquid.

    DTIC Science & Technology

    1983-10-12

    Tam, AppL Phys. Lett. 40, 310 (1982). 7. G. C. Wetsel , Jr., in Acoustic Imaging, Vol. 12, edited by E. A. Ash and C. R. Hill (Plenum, New York, 1982...p. 137. 8. G. C. Wetsel , "Photothermal Excitation of Elastic Waves by 10 ns Laser Pulses and Detection by Photoelastic Laser Beam Deflection," to

  10. Ultra-high-resolution turbulence, flux, and wind profiles using new acoustic profiler designs

    NASA Astrophysics Data System (ADS)

    Bradley, S. G.; von Hünerbein, S.

    2009-09-01

    We give an overview of new developments in acoustic remote sensing of the lowest 150m of the atmosphere. These developments are driven by requirements for higher resolution continuous profiling in more demanding environments than traditionally addressed by SODARs. In wind energy applications there is a need for more accurate wind measurement for wind turbine monitoring, and measurements in a shear environment for wind farm site evaluation in complex terrain. More accurate wind measurement requires better specification on instrument design as well as accounting for spatial coherence variations between the sampling volumes used to derive the wind vector components at each height. These requirements give rise to new hardware and software approaches. A new bi-static design overcomes problems arising in complex terrain due to spatial variation in the wind components between sampling volumes in conventional SODARs. In studies of urban environments, profiling must be done at high spatial resolution, starting within a few meters of the ground and extending to around 100m, so that the structure within the street canyon canopy and the transition to the overlying boundary layers can be sampled. We describe extensions of the bi-static SODAR development for this purpose and the upcoming UK field campaigns in London. As a third example, we describe the exciting outcomes of the European/Australian SNODAR/PLATO high resolution astronomy at Dome C in the Antarctic, in which very high quality optical imaging is supported by 1m resolution turbulence measurements in the lowest 50m. Finally, we discuss new methodologies for obtaining continuous flux profiles from a bi-static design.

  11. Global geodesic acoustic mode in a tokamak with positive magnetic shear and a monotonic temperature profile

    NASA Astrophysics Data System (ADS)

    Ilgisonis, V. I.; Khalzov, I. V.; Lakhin, V. P.; Smolyakov, A. I.; Sorokina, E. A.

    2014-03-01

    The analytical solution for global geodesic acoustic modes (GGAMs) in a tokamak with a positive magnetic shear profile and a monotonic temperature profile is found in the framework of magnetohydrodynamic theory. The axisymmetric eigenvalue problem for perturbed pressure and electrostatic potential is formulated as a recurrent set of equations for poloidal Fourier harmonics. The integral condition for the existence of GGAMs is obtained. It is shown that the traditional paradigm of having a off-axis maximum of the local geodesic acoustic frequency is not necessary for the existence of GGAMs; a representative example is designed.

  12. Diversity of acoustic tracheal system and its role for directional hearing in crickets

    PubMed Central

    2013-01-01

    Background Sound localization in small insects can be a challenging task due to physical constraints in deriving sufficiently large interaural intensity differences (IIDs) between both ears. In crickets, sound source localization is achieved by a complex type of pressure difference receiver consisting of four potential sound inputs. Sound acts on the external side of two tympana but additionally reaches the internal tympanal surface via two external sound entrances. Conduction of internal sound is realized by the anatomical arrangement of connecting trachea. A key structure is a trachea coupling both ears which is characterized by an enlarged part in its midline (i.e., the acoustic vesicle) accompanied with a thin membrane (septum). This facilitates directional sensitivity despite an unfavorable relationship between wavelength of sound and body size. Here we studied the morphological differences of the acoustic tracheal system in 40 cricket species (Gryllidae, Mogoplistidae) and species of outgroup taxa (Gryllotalpidae, Rhaphidophoridae, Gryllacrididae) of the suborder Ensifera comprising hearing and non hearing species. Results We found a surprisingly high variation of acoustic tracheal systems and almost all investigated species using intraspecific acoustic communication were characterized by an acoustic vesicle associated with a medial septum. The relative size of the acoustic vesicle - a structure most crucial for deriving high IIDs - implies an important role for sound localization. Most remarkable in this respect was the size difference of the acoustic vesicle between species; those with a more unfavorable ratio of body size to sound wavelength tend to exhibit a larger acoustic vesicle. On the other hand, secondary loss of acoustic signaling was nearly exclusively associated with the absence of both acoustic vesicle and septum. Conclusion The high diversity of acoustic tracheal morphology observed between species might reflect different steps in the evolution

  13. One dimensional acoustic direct nonlinear inversion using the Volterra inverse scattering series

    NASA Astrophysics Data System (ADS)

    Yao, Jie; Lesage, Anne-Cécile; Bodmann, Bernhard G.; Hussain, Fazle; Kouri, Donald J.

    2014-06-01

    Direct inversion of acoustic scattering problems is nonlinear. One way to treat the inverse scattering problem is based on the reversion of the Born-Neumann series solution of the Lippmann-Schwinger equation. An important issue for this approach is the radius of convergence of the Born-Neumann series for the forward problem. However, this issue can be tackled by employing a renormalization technique to transform the Lippmann-Schwinger equation from a Fredholm to a Volterra integral form. The Born series of a Volterra integral equation converges absolutely and uniformly in the entire complex plane. We present a further study of this new mathematical framework. A Volterra inverse scattering series (VISS) using both reflection and transmission data is derived and tested for several acoustic velocity models. For large velocity contrast, series summation techniques (e.g., Cesàro summation, Euler transform, etc) are employed to improve the rate of convergence of VISS. It is shown that the VISS method with summation techniques can provide a relatively good estimation of the velocity profile. The method is fully data-driven in the respect that no prior information of the model is required. Besides, no internal multiple removal is needed. This one dimensional VISS approach is useful for inverse scattering and serves as an important step for studying more complicated and realistic inversions.

  14. Irony as a game of implicitness: acoustic profiles of ironic communication.

    PubMed

    Anolli, L; Ciceri, R; Infantino, M G

    2000-05-01

    Irony, as "quotation" and "fencing game," consists of an interactive script, grounded on a focal event "trigger," in which the dialogic comment shows the ironist's intention through an antiphrastic process and syncoding to "hit" the victim of the irony (blame by praise or praise by blame). Through acoustic analysis of the suprasegmental profiles of standard phrases inserted into inductors expressly composed and read by 50 naive subjects, the presence and nature of significant differences between sarcastic and kind irony in low- and high-context utterances (contextualization effect--Experiments 1 and 2) have been verified. It has also been observed that, where more "specific weight" is given to the linguistic stream (corrective irony hypothesis), a markedness of suprasegmental features emerges (correctivity effect--Experiment 3). Finally, comparison between sarcastic irony and blame and between kind irony and praise shows that there exists a precise manner of contrastive syncoding, whereby the voices of irony do not coincide with those of direct blame or praise, but assume a specific caricature and emphatic profile (contrastivity effect--Experiment 4).

  15. Measurement of acoustic characteristics of Japanese Buddhist temples in relation to sound source location and direction.

    PubMed

    Soeta, Yoshiharu; Shimokura, Ryota; Kim, Yong Hee; Ohsawa, Tomohiro; Ito, Ken

    2013-05-01

    Although temples are important buildings in the Buddhist community, the acoustic quality has not been examined in detail. Buddhist monks change the location and direction according to the ceremony, and associated acoustical changes have not yet been examined scientifically. To discuss the desired acoustics of temples, it is necessary to know the acoustic characteristics appropriate for each phase of a ceremony. In this study, acoustic measurements were taken at various source locations and directions in Japanese temples. A directional loudspeaker was used as the source to provide vocal acoustic fields, and impulse responses were measured and analyzed. The speech transmission index was higher and the interaural cross-correlation coefficient was lower for the sound source directed toward the side wall than that directed toward the altar. This suggests that the change in direction improves speech intelligibility, and the asymmetric property of direct sound and complex reflections from the altar and side wall increases the apparent source width. The large and coupled-like structure of the altar of a Buddhist temple may have reinforced the reverberation components and the table in the altar, which is called the "syumidan," may have decreased binaural coherence.

  16. The directional sensitivity of the acoustic radiation force to particle diameter.

    PubMed

    Ran, W; Saylor, J R

    2015-06-01

    When viscous corrections to the inviscid acoustic radiation force theory are implemented and applied to a standing wave field, the direction of the acoustic radiation force on particles varies from theory to theory. Specifically, some theories predict that the direction of the force depends on the particle diameter, while others reveal that the direction of the force is independent of particle diameter. The present study is an experimental investigation of the direction of the acoustic radiation force which suggests that particle diameter does affect the direction. Experiments were conducted in air using an ultrasonic standing wave field with a nominal frequency of 30 kHz. Smoke particles and fine water droplets having a range of diameters were flowed into the region of a standing wave field. The direction of the acoustic radiation force was determined by observing whether the particles accumulated in the nodes or the anti-nodes of the standing wave. Results show a change in the direction of the acoustic radiation force at a particle diameter of 0.3±0.1 μm, which corresponds to a particle diameter to acoustic-boundary-layer thickness ratio of 0.023±0.008.

  17. Acoustic sounding of wind velocity profiles in a stratified moving atmosphere.

    PubMed

    Ostashev, V E; Georges, T M; Clifford, S F; Goedecke, G H

    2001-06-01

    The paper deals with analytical and numerical studies of the effects of atmospheric stratification on acoustic remote sensing of wind velocity profiles by sodars. Both bistatic and monostatic schemes are considered. Formulas for the Doppler shift of an acoustic echo signal scattered by atmospheric turbulence advected with the mean wind in a stratified moving atmosphere are derived. Numerical studies of these formulas show that errors in retrieving wind velocity can be of the order of 1 m/s if atmospheric stratification is ignored. Formulas for the height at which wind velocity is retrieved are also derived. Approaches are proposed which allow one to take into account the effects of atmospheric stratification when restoring the wind velocity profile from measured values of the Doppler shift and the time interval of acoustic impulse propagation from a sodar to the scattering volume and back to the ground.

  18. Constraints on Methane Distribution from Acoustic Profiles of Shallow Sediments Across the Alaska Shelf

    NASA Astrophysics Data System (ADS)

    Wood, W. T.; Hart, P. E.; Greinert, J.; de Batist, M. A.; Rose, K.; Coffin, R. B.

    2009-12-01

    In September of 2009 the U. S. Naval Research Laboratory, U. S. Dept of Energy, and Royal Netherlands Institute for Sea Research conducted piston coring, acoustic profiling, and water sampling on the Alaskan Arctic shelf from the U. S. Coast Guard icebreaker Polar Sea, as part of the MITAS (Methane In The Arctic Shelf) project. The overall project objective is to determine the role of methane in arctic shelf processes by determining the source, distribution, and concentration of shallow (0-30m methane accumulations as well as active and potential methane seeps along selected transects across and along the Alaskan Beaufort Sea shelf. The specific objective of the acoustic program is to delineate gas (methane) by mapping bubble release into the water column (flare detection), and free gas indications as acoustic blanking and gas fronts in the sediment. The data consist of 3.5 kHz, 12 kHz profiles acquired using hull-mounted transducers on the Polar Sea, in conjunction with 3.5 kHz sub-bottom profiler and 180 kHz multi-beam data acquired from the Polar Sea's ASB (Arctic Service Boat). Acoustic profiles and images, as well as preliminary interpretations are discussed in the presentation.

  19. Bias in mean velocities and noise in variances and covariances measured using a multistatic acoustic profiler: the Nortek Vectrino Profiler

    NASA Astrophysics Data System (ADS)

    Thomas, R. E.; Schindfessel, L.; McLelland, S. J.; Creëlle, S.; De Mulder, T.

    2017-07-01

    This paper compiles the technical characteristics and operating principles of the Nortek Vectrino Profiler and reviews previously reported user experiences. A series of experiments are then presented that investigate instrument behaviour and performance, with a particular focus on variations within the profile. First, controlled tests investigate the sensitivity of acoustic amplitude (and Signal-to-Noise Ratio, SNR) and pulse-to-pulse correlation coefficient, R 2, to seeding concentration and cell geometry. Second, a novel methodology that systematically shifts profiling cells through a single absolute vertical position investigates the sensitivity of mean velocities, SNR and noise to: (a) emitted sound intensity and the presence (or absence) of acoustic seeding; and (b) varying flow rates under ideal acoustic seeding conditions. A new solution is derived to quantify the noise affecting the two perpendicular tristatic systems of the Vectrino Profiler and its contribution to components of the Reynolds stress tensor. Results suggest that for the Vectrino Profiler: 1. optimum acoustic seeding concentrations are ~3000 to 6000 mg L-1 2. mean velocity magnitudes are biased by variable amounts in proximal cells but are consistently underestimated in distal cells; 3. noise varies parabolically with a minimum around the ‘sweet spot’, 50 mm below the transceiver; 4. the receiver beams only intersect at the sweet spot and diverge nearer to and further from the transceiver. This divergence significantly reduces the size of the sampled area away from the sweet spot, reducing data quality; 5. the most reliable velocity data will normally be collected in the region between approximately 43 and 61 mm below the transceiver.

  20. Directional Reflective Surface Formed via Gradient-Impeding Acoustic Meta-Surfaces

    NASA Astrophysics Data System (ADS)

    Song, Kyungjun; Kim, Jedo; Hur, Shin; Kwak, Jun-Hyuk; Lee, Seong-Hyun; Kim, Taesung

    2016-08-01

    Artificially designed acoustic meta-surfaces have the ability to manipulate sound energy to an extraordinary extent. Here, we report on a new type of directional reflective surface consisting of an array of sub-wavelength Helmholtz resonators with varying internal coiled path lengths, which induce a reflection phase gradient along a planar acoustic meta-surface. The acoustically reshaped reflective surface created by the gradient-impeding meta-surface yields a distinct focal line similar to a parabolic cylinder antenna, and is used for directive sound beamforming. Focused beam steering can be also obtained by repositioning the source (or receiver) off axis, i.e., displaced from the focal line. Besides flat reflective surfaces, complex surfaces such as convex or conformal shapes may be used for sound beamforming, thus facilitating easy application in sound reinforcement systems. Therefore, directional reflective surfaces have promising applications in fields such as acoustic imaging, sonic weaponry, and underwater communication.

  1. Directional Reflective Surface Formed via Gradient-Impeding Acoustic Meta-Surfaces

    PubMed Central

    Song, Kyungjun; Kim, Jedo; Hur, Shin; Kwak, Jun-Hyuk; Lee, Seong-Hyun; Kim, Taesung

    2016-01-01

    Artificially designed acoustic meta-surfaces have the ability to manipulate sound energy to an extraordinary extent. Here, we report on a new type of directional reflective surface consisting of an array of sub-wavelength Helmholtz resonators with varying internal coiled path lengths, which induce a reflection phase gradient along a planar acoustic meta-surface. The acoustically reshaped reflective surface created by the gradient-impeding meta-surface yields a distinct focal line similar to a parabolic cylinder antenna, and is used for directive sound beamforming. Focused beam steering can be also obtained by repositioning the source (or receiver) off axis, i.e., displaced from the focal line. Besides flat reflective surfaces, complex surfaces such as convex or conformal shapes may be used for sound beamforming, thus facilitating easy application in sound reinforcement systems. Therefore, directional reflective surfaces have promising applications in fields such as acoustic imaging, sonic weaponry, and underwater communication. PMID:27562634

  2. High-resolution velocimetry in energetic tidal currents using a convergent-beam acoustic Doppler profiler

    SciTech Connect

    Sellar, Brian; Harding, Samuel F.; Richmond, Marshall C.

    2015-07-16

    An array of convergent acoustic Doppler velocimeters has been developed and tested for the high resolution measurement of three-dimensional tidal flow velocities in an energetic tidal site. This configuration has been developed to increase spatial resolution of velocity measurements in comparison to conventional acoustic Doppler profilers (ADPs) which characteristically use diverging acoustic beams emanating from a single instrument. This is achieved using converging acoustic beams with a sample volume at the focal point of 0.03 m3. The array is also able to simultaneously measure three-dimensional velocity components in a profile throughout the water column, and as such is referred to herein as a converging-beam acoustic Doppler profiler (CADP). Mid-depth profiling is achieved through integration of the sensor platform with the operational Alstom 1MW DeepGen-IV Tidal Turbine. This proof-of-concept paper outlines system configuration and comparison to measurements provided by co-installed reference instrumentation. Comparison of CADP to standard ADP velocity measurements reveals a mean difference of 8 mm/s, standard deviation of 18 mm/s, and order-of-magnitude reduction in realizable length-scale. CADP focal point measurements compared to a proximal single-beam reference show peak cross-correlation coefficient of 0.96 over 4.0 s averaging period and a 47% reduction in Doppler noise. The dual functionality of the CADP as a profiling instrument with a high resolution focal point make this configuration a unique and valuable advancement in underwater velocimetry enabling improved turbulence, resource and structural loading quantification and validation of numerical simulations. Alternative modes of operation have been implemented including noise-reducing bi-static sampling. Since waves are simultaneously measured it is expected that derivatives of this system will be a powerful tool in wave-current interaction studies.

  3. Radio acoustic measurement of temperature profile in the troposphere and stratosphere

    NASA Astrophysics Data System (ADS)

    Matuura, N.; Masuda, Y.; Inuki, H.; Kato, S.; Fukao, S.; Sato, T.; Tsuda, T.

    1986-10-01

    The radio acoustic sounding system (RASS) uses radar to measure the temperature profile in the atmosphere. In the standard technique of atmospheric radar, the radar backscatter results from electrical permittivity variations due to natural phenomena such as turbulence and precipitation. In the RASS technique, the radar backscatter results from periodical permittivity variations due to density/temperature variations imposed on the atmosphere by an acoustic wave artificially generated in such a way that the acoustic wavelength is half the radar (electromagnetic) wavelength. This `Bragg condition' is necessary for efficient backscattering. The backscatter echo of the RASS is affected by the Doppler frequency shift arising both from the speed at which the longitudinal acoustic perturbations propagate (the sound speed), and from the radial bulk velocity in the common volume of the atmosphere-the latter can be measured by the standard technique of turbulence scatter. The observed sound speed is reduced to give the local atmospheric temperature. Here we report an experiment using the RASS, carried out on 1-3 August 1985, which consisted of a high-power, very-high-frequency (VHF) Doppler radar at Shigaraki, Shiga, Japan and a movable high-power acoustic transmitter, and which gave the first experimental proof of the possibility of temperature profiling in the troposphere and stratosphere up to an altitude of ~20 km.

  4. Acoustic sounder system design for measurement of optical turbulence and wind profiles

    NASA Astrophysics Data System (ADS)

    Miller, Judith E.; Eaton, Frank D.; Stokes, Sheldon S.

    2000-07-01

    An Acoustic Sounder System has been installed on the side of the cliff at North Oscura Peak, WSMR to provide important refractive index structure parameter, Cn2 data for laser propagation tests. The acoustic sounder system records echo information that is used to provide 3D wind and optical turbulence profiles. The received signal is the product of the interaction of the transmitted acoustic pulse with the small scale atmospheric temperature variations. This information is displayed as a time-height display of the signal intensity. The frequency of the received signals are processed and converted into time histories of the horizontal wind field. The data from the Acoustic Sounder is calibrated with the hot-wire anemometer temperature structure parameter (Ct2) data, and meteorological data measured locally to produce the Cn2 profile. The design and location of the Acoustic Sounder System will be discussed along with the methodology of extracting the turbulence. Many days of data have been collected and representative data will be shown.

  5. Scanning probe acoustic microscopy of extruded starch materials: direct visual evidence of starch crystal.

    PubMed

    Liu, Zhongdong; Liu, Boxiang; Li, Mengxing; Wei, Min; Li, Hua; Liu, Peng; Wan, Tuo

    2013-10-15

    Scanning probe acoustic microscopy (SPAM) has been successfully used to study inorganic and keratin biomaterials. However, few studies have attempted to apply SPAM to structural study of non-keratin organic materials such as starch based materials. This study investigated hardness and surface finish to establish sample preparation method suitable for SPAM imaging and acquired clear acoustic images of extruded starch materials. Acquired acoustic images directly exhibited certain structure of starch materials and provided visual evidence of starch material components and aggregates. In addition, through correlating acoustic images with X-ray diffraction data, crystal-structural information in nano-scale was obtained and acoustic image contrast showed a linear relationship with starch amylose content in extruded starch materials.

  6. Monitoring suspended sediment transport in an ice-affected river using acoustic Doppler current profilers

    NASA Astrophysics Data System (ADS)

    Moore, S. A.; Ghareh Aghaji Zare, S.; Rennie, C. D.; Ahmari, H.; Seidou, O.

    2013-12-01

    Quantifying sediment budgets and understanding the processes which control fluvial sediment transport is paramount to monitoring river geomorphology and ecological habitat. In regions that are subject to freezing there is the added complexity of ice. River ice processes impact flow distribution, water stage and sediment transport. Ice processes typically have the largest impact on sediment transport and channel morphodynamics when ice jams occur during ice cover formation and breakup. Ice jams may restrict flow and cause local acceleration when released. Additionally, ice can mechanically scour river bed and banks. Under-ice sediment transport measurements are lacking due to obvious safety and logistical reasons, in addition to a lack of adequate measurement techniques. Since some rivers can be covered in ice during six months of the year, the lack of data in winter months leads to large uncertainty in annual sediment load calculations. To address this problem, acoustic profilers are being used to monitor flow velocity, suspended sediment and ice processes in the Lower Nelson River, Manitoba, Canada. Acoustic profilers are ideal for under-ice sediment flux measurements since they can be operated autonomously and continuously, they do not disturb the flow in the zone of measurement and acoustic backscatter can be related to sediment size and concentration. In March 2012 two upward-facing profilers (1200 kHz acoustic Doppler current profiler, 546 KHz acoustic backscatter profiler) were installed through a hole in the ice on the Nelson River, 50 km downstream of the Limestone Generating Station. Data were recorded for four months, including both stable cover and breakup periods. This paper presents suspended sediment fluxes calculated from the acoustic measurements. Velocity data were used to infer the vertical distribution of sediment sizes and concentrations; this information was then used in the interpretation of the backscattered intensity data. It was found that

  7. Flight effects on the aerodynamic and acoustic characteristics of inverted profile coannular nozzles, volume 1. [supersonic cruise aircraft research wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    Jet noise spectra obtained at static conditions from an acoustic wind tunnel and an outdoor facility are compared. Data curves are presented for (1) the effect of relative velocity on OASPL directivity (all configurations); (2) the effect of relative velocity on noise spectra (all configurations); (3) the effect of velocity on PNL directivity (coannular nozzle configurations); (4) nozzle exhaust plume velocity profiles; and (5) the effect of relative velocity on aerodynamic performance.

  8. Asymptotic permanent profile of the ion acoustic wave driven by the Langmuir wave

    NASA Astrophysics Data System (ADS)

    Kaup, D. J.; Latifi, A.; Leon, J.

    1992-08-01

    We study the evolution of Langmuir waves coupled to the ion acoustic wave by means of the ponderomotive force in the Karpman limit (caviton equation). Using the spectral transform with singular dispersion relation, it is shown that the background noise (fluctuations in the ion density) is amplified and its time asymptotic behavior will be a static solution which is totally reflective for the Langmuir wave. Moreover, if the initial ion density contains a local depression, the asymptotic profile will contain a number of permanent localized density depressions (cavitons), static in the rest frame of the acoustic wave and entrained in its wake.

  9. Development of a Radio Acoustic Sounding System (RASS) for continuous temperature profiling upto lower stratospheric altitudes

    NASA Astrophysics Data System (ADS)

    Chandrasekhar Sarma, T. V.; Tsuda, Toshitaka

    2012-07-01

    The Gadanki (13.46°N, 79.17°E) MST radar is a high power VHF pulsed coherent Doppler radar established for remote probing of atmospheric phenomena in the Mesosphere Stratosphere Troposphere regions. Radio Acoustic Sounding System (RASS) was developed using this radar to obtain height profiles of atmospheric temperature up to lower stratospheric altitudes. RASS uses the effect of temperature on the speed of sound in air as a means to sense the atmospheric temperature. It is the combination of a Doppler radar and acoustic exciters. The radar was augmented with acoustic exciters that were designed and constructed for this purpose. The Doppler radar profiles the speed of refractive index perturbations induced by the acoustic source. RASS has been demonstrated to be a reliable ground-based remote profiling technique to obtain altitude profiles of atmospheric virtual temperature, Tv over the past two decades. This work describes the design of the system and its application to the observation of height profiles of atmospheric virtual temperature up to and beyond tropical tropopause altitudes. Observations were made during 2007, 2008 and 2009 over periods extending up to 72 hours. These observations demonstrate temperature profiling capability up to about 18 km in altitude, though on an occasion height coverage upto 22.8km was obtained briefly; lowest height covered is from about 1.5km onwards. During the period of the RASS observations simultaneous data from radiosonde was used to validate the temperature measurements. Simultaneous satellite-based measurement of outgoing long wave radiation (OLR) and precipitation from ground-based instruments was used to study the atmospheric phenomena of gravity waves and atmospheric stability during a convection event.

  10. Direct calculation of acoustic streaming including the boundary layer phenomena in an ultrasonic air pump

    NASA Astrophysics Data System (ADS)

    Wada, Yuji; Koyama, Daisuke; Nakamura, Kentaro

    2012-05-01

    Direct finite difference fluid simulation of acoustic streaming on the fine-meshed three-dimensiona model by graphics processing unit (GPU)-oriented calculation array is discussed. Airflows due to the acoustic traveling wave are induced when an intense sound field is generated in a gap between a bending transducer and a reflector. Calculation results showed good agreement with the measurements in the pressure distribution. In addition to that, several flow-vortices were observed near the boundary of the reflector and the transducer, which have been often discussed in acoustic tube near the boundary, and have never been observed in the calculation in the ultrasonic air pump of this type.

  11. Directional acoustic measurements by laser Doppler velocimeters. [for jet aircraft noise

    NASA Technical Reports Server (NTRS)

    Mazumder, M. K.; Overbey, R. L.; Testerman, M. K.

    1976-01-01

    Laser Doppler velocimeters (LDVs) were used as velocity microphones to measure sound pressure level in the range of 90-130 db, spectral components, and two-point cross correlation functions for acoustic noise source identification. Close agreement between LDV and microphone data is observed. It was concluded that directional sensitivity and the ability to measure remotely make LDVs useful tools for acoustic measurement where placement of any physical probe is difficult or undesirable, as in the diagnosis of jet aircraft noise.

  12. Functional relevance of acoustic tracheal design in directional hearing in crickets.

    PubMed

    Schmidt, Arne K D; Römer, Heiner

    2016-10-15

    Internally coupled ears (ICEs) allow small animals to reliably determine the direction of a sound source. ICEs are found in a variety of taxa, but crickets have evolved the most complex arrangement of coupled ears: an acoustic tracheal system composed of a large cross-body trachea that connects two entry points for sound in the thorax with the leg trachea of both ears. The key structure that allows for the tuned directionality of the ear is a tracheal inflation (acoustic vesicle) in the midline of the cross-body trachea holding a thin membrane (septum). Crickets are known to display a wide variety of acoustic tracheal morphologies, most importantly with respect to the presence of a single or double acoustic vesicle. However, the functional relevance of this variation is still not known. In this study, we investigated the peripheral directionality of three co-occurring, closely related cricket species of the subfamily Gryllinae. No support could be found for the hypothesis that a double vesicle should be regarded as an evolutionary innovation to (1) increase interaural directional cues, (2) increase the selectivity of the directional filter or (3) provide a better match between directional and sensitivity tuning. Nonetheless, by manipulating the double acoustic vesicle in the rainforest cricket Paroecanthus podagrosus, selectively eliminating the sound-transmitting pathways, we revealed that these pathways contribute almost equally to the total amount of interaural intensity differences, emphasizing their functional relevance in the system. © 2016. Published by The Company of Biologists Ltd.

  13. Aquatic habitat mapping with an acoustic doppler current profiler: Considerations for data quality

    USGS Publications Warehouse

    Gaeuman, David; Jacobson, Robert B.

    2005-01-01

    When mounted on a boat or other moving platform, acoustic Doppler current profilers (ADCPs) can be used to map a wide range of ecologically significant phenomena, including measures of fluid shear, turbulence, vorticity, and near-bed sediment transport. However, the instrument movement necessary for mapping applications can generate significant errors, many of which have not been inadequately described. This report focuses on the mechanisms by which moving-platform errors are generated, and quantifies their magnitudes under typical habitat-mapping conditions. The potential for velocity errors caused by mis-alignment of the instrument?s internal compass are widely recognized, but has not previously been quantified for moving instruments. Numerical analyses show that even relatively minor compass mis-alignments can produce significant velocity errors, depending on the ratio of absolute instrument velocity to the target velocity and on the relative directions of instrument and target motion. A maximum absolute instrument velocity of about 1 m/s is recommended for most mapping applications. Lower velocities are appropriate when making bed velocity measurements, an emerging application that makes use of ADCP bottom-tracking to measure the velocity of sediment particles at the bed. The mechanisms by which heterogeneities in the flow velocity field generate horizontal velocities errors are also quantified, and some basic limitations in the effectiveness of standard error-detection criteria for identifying these errors are described. Bed velocity measurements may be particularly vulnerable to errors caused by spatial variability in the sediment transport field.

  14. Acoustic Doppler Current Profiler Data Processing System manual [ADCP

    USGS Publications Warehouse

    Cote, Jessica M.; Hotchkiss, Frances S.; Martini, Marinna; Denham, Charles R.; revisions by Ramsey, Andree L.; Ruane, Stephen

    2000-01-01

    This open-file report describes the data processing software currently in use by the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), to process time series of acoustic Doppler current data obtained by Teledyne RD Instruments Workhorse model ADCPs. The Sediment Transport Instrumentation Group (STG) at the WHCMSC has a long-standing commitment to providing scientists high quality oceanographic data published in a timely manner. To meet this commitment, STG has created this software to aid personnel in processing and reviewing data as well as evaluating hardware for signs of instrument malfunction. The output data format for the data is network Common Data Form (netCDF), which meets USGS publication standards. Typically, ADCP data are recorded in beam coordinates. This conforms to the USGS philosophy to post-process rather than internally process data. By preserving the original data quality indicators as well as the initial data set, data can be evaluated and reprocessed for different types of analyses. Beam coordinate data are desirable for internal and surface wave experiments, for example. All the code in this software package is intended to run using the MATLAB program available from The Mathworks, Inc. As such, it is platform independent and can be adapted by the USGS and others for specialized experiments with non-standard requirements. The software is continuously being updated and revised as improvements are required. The most recent revision may be downloaded from: http://woodshole.er.usgs.gov/operations/stg/Pubs/ADCPtools/adcp_index.htm The USGS makes this software available at the user?s discretion and responsibility.

  15. Directional decomposition of the acoustic wave equation for fluids and metafluids in spherical geometries, with application to transformational acoustics

    NASA Astrophysics Data System (ADS)

    Olsson, Peter

    2016-03-01

    A new directional decomposition of the acoustic 3D wave equation is derived for spherically symmetric geometries, where the wave fields do not need to possess such a symmetry. This provides an alternative basis for various applications of techniques like invariant embedding and time domain Green functions in spherically symmetric geometries. Contrary to previous results on spherical wave splittings, the new decomposition is given in a very explicit form. The wave equation considered incorporates effects from radially varying compressibility and density, but also from anisotropic density, a property of certain so called metafluids. By applying the new spherical wave splitting, we show that all spherically symmetric acoustic metafluid cloaks are diffeomorphic images of a homogeneous and isotropic spherical ball of perfect fluid.

  16. Acoustic profiles and images of the Palos Verdes margin: Implications concerning deposition from the White's Point outfall

    USGS Publications Warehouse

    Hampton, M.A.; Karl, Herman A.; Murray, C.J.

    2002-01-01

    Subbottom profiles and sidescan-sonar images collected on and around the Palos Verdes Shelf show a surficial deposit interpreted to contain effluent from the White's Point diffusers, as well as showing several geologic features that affect the deposit's distribution. The effluent-affected deposit is visible in high-resolution subbottom profiles on the shelf and the adjacent San Pedro basin slope to water depths of 170 m. It has a maximum thickness of 75 cm and was mapped acoustically over an area of 10.8 km2, which encompasses a volume of about 3.2 million m3. The deposit's basal reflector is acoustically distinct over most of the mapped area. implying that the deposit has not been extensively mixed across its base, perhaps being relatively free of reworking since its initial deposition. Nearshore, the basal reflector is weak and fades away toward land, which could result from syndepositional intermixing of coarse native sediment (particularly from the Portuguese Bend landslide) with effluent in the high-energy nearshore zone, or postdepositionally by physical (wave) or biological mixing across the interface. The geometry of the deposit implies that effluent is dispersed primarily in a northwesterly and seaward direction from the diffusers. Dispersal across the shelf break is in some places strongly affected by topography, particularly by submarine canyons. The deposit overlies stratified and unstratified Quaternary sediment, up to 30m thick, that in turn overlies the irregular erosional surface of deformed Miocene bedrock that crops out in places on the shelf and upper basin slope. The effluent-affected deposit rests on potentially unstable landslide deposits on the San Pedro basin slope. The acoustic profiles and side-scan images show evidence for active and inactive vents, probably of hot water and gas, some of which are within the boundary of the effluent-affected sediment deposit and could disrupt it if seepage occurs. ?? 2002 Elsevier Science Ltd. All rights

  17. Acoustic profiles and images of the Palos Verdes Margin: Implications concerning deposition from the White's Point outfall

    SciTech Connect

    Hampton, M A.; Karl, H; Murray, Christopher J. )

    2001-12-01

    Subbottom profiles and sidescan-sonar images collected on and around the Palos Verdes shelf show a surficial deposit interpreted to contain effluent from the White's Point diffusers, as well as showing several geologic features that affect the deposit's distribution. The effluent-affected deposit is visible in high-resolution subbottom profiles on the shelf and the adjacent San Pedro basin slope to water depths of 170 m. It has a maximum thickness of 75 cm and was mapped acoustically over an area of 10.8 km{sup 2}, which encompasses a volume of about 3.2 million m{sup 3}. The deposit's basal reflector is acoustically distinct over most of the mapped area, implying that the deposit has not been extensively mixed across its base, perhaps being relatively free of reworking since its initial deposition. Nearshore, the basal reflector is weak and fades away toward land, which could result from syndepositional intermixing of coarse native sediment (particularly from the Portuguese Bend landslide) with effluent in the high-energy nearshore zone, or postdepositionally by physical (wave) or biological mixing across the interface. The geometry of the deposit implies that effluent is dispersed primarily in a northwesterly and seaward direction from the diffusers. Dispersal across the shelf break is in some places strongly affected by topography, particularly by submarine canyons. The deposit overlies stratified and unstratified Quaternary sediment, up to 30 m thick, that in turn overlies the irregular erosional surface of deformed Miocene bedrock that crops out in places on the shelf and upper basin slope. The effluent-affected deposit rests on potentially unstable landslide deposits on the San Pedro basin slope. The acoustic profiles and side-scan images show evidence for active and inactive vents, probably of hot water and gas, some of which are within the boundary of the effluent-affected sediment deposit and could disrupt it if seepage occurs.

  18. Shipboard Acoustic Current Profiling during the Coastal Ocean Dynamics Experiment,

    DTIC Science & Technology

    1985-05-01

    5 3. Data Processing and Error Analysis ....................................................... 12 3.1. Instrumentation...deviate from the assumptions of the objective analysis ). Fig. 5.1 : CODE 2 (1982) moored current meter arra.. Table 5.1 provides 47 details on...T(-)A 7.5(r) -I I)A1’A fPl’OCE.’SlNC AN!) EIMOR ANALYSIS Nilak inrg shiil ard ’stiiia e of i’ urerit profils req o re knrowing Ix (1). the

  19. Nonlinear acoustics with low-profile piezoceramic excitation for crack detection in metallic structures

    NASA Astrophysics Data System (ADS)

    Parsons, Z.; Staszewski, W. J.

    2006-08-01

    Structural damage detection is one of the major maintenance activities in a wide range of industries. A variety of different methods have been developed for detection of fatigue cracks in metallic structures over the last few decades. This includes techniques based on stress/acoustic waves propagating in monitored structures. Classical ultrasonic techniques used in nondestructive testing and evaluation are based on linear amplitude and/or phase variations of reflected, transmitted or scattered waves. In recent years a range of different techniques utilizing nonlinear phenomena in vibration and acoustic signals have been developed. It appears that these techniques are more sensitive to damage alterations than other techniques used for damage detection based on linear behaviour. The paper explores the use of low-profile piezoceramic actuators with low-frequency excitation in nonlinear acoustics. The method is used to detect a fatigue crack in an aluminium plate. The results are compared with modal/vibration excitation performed with an electromagnetic shaker. The study shows that piezoelectric excitation with surface-bonded low-profile piezoceramic transducers is suitable for crack detection based on nonlinear acoustics.

  20. High-resolution velocimetry in energetic tidal currents using a convergent-beam acoustic Doppler profiler

    NASA Astrophysics Data System (ADS)

    Sellar, Brian; Harding, Samuel; Richmond, Marshall

    2015-08-01

    An array of single-beam acoustic Doppler profilers has been developed for the high resolution measurement of three-dimensional tidal flow velocities and subsequently tested in an energetic tidal site. This configuration has been developed to increase spatial resolution of velocity measurements in comparison to conventional acoustic Doppler profilers (ADPs) which characteristically use divergent acoustic beams emanating from a single instrument. This is achieved using geometrically convergent acoustic beams creating a sample volume at the focal point of 0.03 m3. Away from the focal point, the array is also able to simultaneously reconstruct three-dimensional velocity components in a profile throughout the water column, and is referred to herein as a convergent-beam acoustic Doppler profiler (C-ADP). Mid-depth profiling is achieved through integration of the sensor platform with the operational commercial-scale Alstom 1 MW DeepGen-IV Tidal Turbine deployed at the European Marine Energy Center, Orkney Isles, UK. This proof-of-concept paper outlines the C-ADP system configuration and comparison to measurements provided by co-installed reference instrumentation. Comparison of C-ADP to standard divergent ADP (D-ADP) velocity measurements reveals a mean difference of 8 mm s-1, standard deviation of 18 mm s-1, and an order of magnitude reduction in realisable length scale. C-ADP focal point measurements compared to a proximal single-beam reference show peak cross-correlation coefficient of 0.96 over 4.0 s averaging period and a 47% reduction in Doppler noise. The dual functionality of the C-ADP as a profiling instrument with a high resolution focal point make this configuration a unique and valuable advancement in underwater velocimetry enabling improved quantification of flow turbulence. Since waves are simultaneously measured via profiled velocities, pressure measurements and surface detection, it is expected that derivatives of this system will be a powerful tool in

  1. Directional acoustic radiation in the strut display of male sage grouse Centrocercus urophasianus.

    PubMed

    Dantzker, M S; Deane, G B; Bradbury, J W

    1999-11-01

    We present evidence that the acoustic component of the strut display of male sage grouse Centrocercus urophasianus is highly directional and that the nature of this directionality is unique among measured vertebrates. Where vertebrate acoustic signals have been found to be directional, they are most intense anteriorly and are bilaterally symmetrical. Our results show that sage grouse acoustic radiation (beam) patterns are often asymmetric about the birds' anterior-posterior axis. The beam pattern of the 'whistle' note is actually strikingly bilobate with a deep null directly in front of the displaying bird. While the sage grouse display serves to attract potential mates, male sage grouse rarely face females head on when they call. The results of this study suggest that males may reach females with a high-intensity signal despite their preference for an oblique display posture relative to those females. We characterized these patterns using a novel technique that allowed us to map acoustic radiation patterns of unrestrained animals calling in the wild. Using an eight-microphone array, our technique integrates acoustic localization with synchronous pressure-field measurements while controlling for small-scale environmental variation in sound propagation.

  2. Visualizing flow fields using acoustic Doppler current profilers and the Velocity Mapping Toolbox

    USGS Publications Warehouse

    Jackson, P. Ryan

    2013-01-01

    The purpose of this fact sheet is to provide examples of how the U.S. Geological Survey is using acoustic Doppler current profilers for much more than routine discharge measurements. These instruments are capable of mapping complex three-dimensional flow fields within rivers, lakes, and estuaries. Using the Velocity Mapping Toolbox to process the ADCP data allows detailed visualization of the data, providing valuable information for a range of studies and applications.

  3. Near-Inertial and Tidal Currents Detected with a Vessel Mounted Acoustic Doppler Current Profiler in the Western Mediterranean Sea

    NASA Technical Reports Server (NTRS)

    Garcia-Gorriz, E.; Candela, J.; Font, J.

    1998-01-01

    The Acoustic Doppler Current Profiler (ADCP) combined with accurate navigation provides absolute current velocities which include information from all the frequencies which have a dynamical presence in the ocean.

  4. Near-Inertial and Tidal Currents Detected with a Vessel Mounted Acoustic Doppler Current Profiler in the Western Mediterranean Sea

    NASA Technical Reports Server (NTRS)

    Garcia-Gorriz, E.; Candela, J.; Font, J.

    1998-01-01

    The Acoustic Doppler Current Profiler (ADCP) combined with accurate navigation provides absolute current velocities which include information from all the frequencies which have a dynamical presence in the ocean.

  5. Numerical performance analysis of acoustic Doppler velocity profilers in the wake of an axial-flow marine hydrokinetic turbine

    SciTech Connect

    Richmond, Marshall C.; Harding, Samuel F.; Romero Gomez, Pedro DJ

    2015-09-01

    The use of acoustic Doppler current profilers (ADCPs) for the characterization of flow conditions in the vicinity of both experimental and full scale marine hydrokinetic (MHK) turbines is becoming increasingly prevalent. The computation of a three dimensional velocity measurement from divergent acoustic beams requires the assumption that the flow conditions are homogeneous between all beams at a particular axial distance from the instrument. In the near wake of MHK devices, the mean fluid motion is observed to be highly spatially dependent as a result of torque generation and energy extraction. This paper examines the performance of ADCP measurements in such scenarios through the modelling of a virtual ADCP (VADCP) instrument in the velocity field in the wake of an MHK turbine resolved using unsteady computational fluid dynamics (CFD). This is achieved by sampling the CFD velocity field at equivalent locations to the sample bins of an ADCP and performing the coordinate transformation from beam coordinates to instrument coordinates and finally to global coordinates. The error in the mean velocity calculated by the VADCP relative to the reference velocity along the instrument axis is calculated for a range of instrument locations and orientations. The stream-wise velocity deficit and tangential swirl velocity caused by the rotor rotation lead to significant misrepresentation of the true flow velocity profiles by the VADCP, with the most significant errors in the transverse (cross-flow) velocity direction.

  6. A Multipath Calculation of Surface-Generated Underwater Acoustic Ambient Vertical Directivity

    DTIC Science & Technology

    1988-11-18

    nth Eigenray I Homogeneous Source Intensity Density g( Source Directivity dA = r dr dO 0 Azimuthal Position of Source Relative to Receiver * 2...Directional-Frequency Spectra - Multipath Expansion ( Eigenray ) Approach 5 TD 8431 SLIDE 3 Although the calculations were done with a specific location in...Frequency Spectra - Multipath Expansion ( Eigenray ) Approach 0 0 13 0 TD 8431 Multipath Calculation of the Acoustic Vertical Directional Spectra RESULTS e

  7. The average direct current offset values for small digital audio recorders in an acoustically consistent environment.

    PubMed

    Koenig, Bruce E; Lacey, Douglas S

    2014-07-01

    In this research project, nine small digital audio recorders were tested using five sets of 30-min recordings at all available recording modes, with consistent audio material, identical source and microphone locations, and identical acoustic environments. The averaged direct current (DC) offset values and standard deviations were measured for 30-sec and 1-, 2-, 3-, 6-, 10-, 15-, and 30-min segments. The research found an inverse association between segment lengths and the standard deviation values and that lengths beyond 30 min may not meaningfully reduce the standard deviation values. This research supports previous studies indicating that measured averaged DC offsets should only be used for exclusionary purposes in authenticity analyses and exhibit consistent values when the general acoustic environment and microphone/recorder configurations were held constant. Measured average DC offset values from exemplar recorders may not be directly comparable to those of submitted digital audio recordings without exactly duplicating the acoustic environment and microphone/recorder configurations.

  8. Acoustic beam steering by light refraction: illustration with directivity patterns of a tilted volume photoacoustic source.

    PubMed

    Raetz, Samuel; Dehoux, Thomas; Perton, Mathieu; Audoin, Bertrand

    2013-12-01

    The symmetry of a thermoelastic source resulting from laser absorption can be broken when the direction of light propagation in an elastic half-space is inclined relatively to the surface. This leads to an asymmetry of the directivity patterns of both compressional and shear acoustic waves. In contrast to classical surface acoustic sources, the tunable volume source allows one to take advantage of the mode conversion at the surface to control the directivity of specific modes. Physical interpretations of the evolution of the directivity patterns with the increasing light angle of incidence and of the relations between the preferential directions of compressional- and shear-wave emission are proposed. In order to compare calculated directivity patterns with measurements of normal displacement amplitudes performed on plates, a procedure is proposed to transform the directivity patterns into pseudo-directivity patterns representative of the experimental conditions. The comparison of the theoretical with measured pseudo-directivity patterns demonstrates the ability to enhance bulk-wave amplitudes and to steer specific bulk acoustic modes by adequately tuning light refraction.

  9. [Acoustic- and EGG-parametrisations of Phonatory Quality Provide Voice Profiles of Normal Speakers].

    PubMed

    Pützer, M; Wokurek, W

    2015-05-01

    The present study deals with the dimensions of normal phonation. It is generally accepted that there exists a wide range of normal voices. Using complementarily orientated electroglottografic and acoustic parametrisations of phonation quality, sustained vowel productions of 267 male and 267 female speakers without any reported voice pathology were analysed. A clustering technique serves to differentiate gender specific subgroups of normal phonation on the basis of these analysis results. Firstly, 3 subgroups within each gender on the basis of the EGG, and 3 subgroups on the basis of the acoustic parameters are presented. Secondly, this subgroup definition allows one to present voice profiles of normal speakers by combining the parameter means of the electroglottografically determined subgroups with those of the acoustically determined subgroups. The present voice profiles can be used as a reference and are aimed at providing a firmer basis for the classification of different normal and pathological phonation types as well as for the evaluation of shifts in individual phonation behaviour due to therapy or spontaneous recovery. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Effects of the acoustic properties of infant-directed speech on infant word recognition1

    PubMed Central

    Song, Jae Yung; Demuth, Katherine; Morgan, James

    2010-01-01

    A number of studies have examined the acoustic differences between infant-directed speech (IDS) and adult-directed speech, suggesting that the exaggerated acoustic properties of IDS might facilitate infants’ language development. However, there has been little empirical investigation of the acoustic properties that infants use for word learning. The goal of this study was thus to examine how 19-month-olds’ word recognition is affected by three acoustic properties of IDS: slow speaking rate, vowel hyper-articulation, and wide pitch range. Using the intermodal preferential looking procedure, infants were exposed to half of the test stimuli (e.g., Where’s the book?) in typical IDS style. The other half of the stimuli were digitally altered to remove one of the three properties under investigation. After the target word (e.g., book) was spoken, infants’ gaze toward target and distractor referents was measured frame by frame to examine the time course of word recognition. The results showed that slow speaking rate and vowel hyper-articulation significantly improved infants’ ability to recognize words, whereas wide pitch range did not. These findings suggest that 19-month-olds’ word recognition may be affected only by the linguistically relevant acoustic properties in IDS. PMID:20649233

  11. Effects of the acoustic properties of infant-directed speech on infant word recognition.

    PubMed

    Song, Jae Yung; Demuth, Katherine; Morgan, James

    2010-07-01

    A number of studies have examined the acoustic differences between infant-directed speech (IDS) and adult-directed speech, suggesting that the exaggerated acoustic properties of IDS might facilitate infants' language development. However, there has been little empirical investigation of the acoustic properties that infants use for word learning. The goal of this study was thus to examine how 19-month-olds' word recognition is affected by three acoustic properties of IDS: slow speaking rate, vowel hyper-articulation, and wide pitch range. Using the intermodal preferential looking procedure, infants were exposed to half of the test stimuli (e.g., Where's the book?) in typical IDS style. The other half of the stimuli were digitally altered to remove one of the three properties under investigation. After the target word (e.g., book) was spoken, infants' gaze toward target and distractor referents was measured frame by frame to examine the time course of word recognition. The results showed that slow speaking rate and vowel hyper-articulation significantly improved infants' ability to recognize words, whereas wide pitch range did not. These findings suggest that 19-month-olds' word recognition may be affected only by the linguistically relevant acoustic properties in IDS.

  12. Bio-Inspired Miniature Direction Finding Acoustic Sensor

    PubMed Central

    Wilmott, Daniel; Alves, Fabio; Karunasiri, Gamani

    2016-01-01

    A narrowband MEMS direction finding sensor has been developed based on the mechanically coupled ears of the Ormia Ochracea fly. The sensor consists of two wings coupled at the middle and attached to a substrate using two legs. The sensor operates at its bending resonance frequency and has cosine directional characteristics similar to that of a pressure gradient microphone. Thus, the directional response of the sensor is symmetric about the normal axis making the determination of the direction ambiguous. To overcome this shortcoming two sensors were assembled with a canted angle similar to that employed in radar bearing locators. The outputs of two sensors were processed together allowing direction finding with no requirement of knowing the incident sound pressure level. At the bending resonant frequency of the sensors (1.69 kHz) an output voltage of about 25 V/Pa was measured. The angle uncertainty of the bearing of sound ranged from less than 0.3° close to the normal axis (0°) to 3.4° at the limits of coverage (±60°) based on the 30° canted angle used. These findings indicate the great potential to use dual MEMS direction finding sensor assemblies to locate sound sources with high accuracy. PMID:27440657

  13. MEMS directional acoustic sensor for locating sound sources

    NASA Astrophysics Data System (ADS)

    Karunasiri, Gamani; Alves, Fabio; Swan, William

    2016-02-01

    The conventional directional sound sensing systems employ an array of spatially separated microphones to achieve directional sensing. However, there are insects such as Ormia ochracea fly that can determine the direction of sound using a miniature hearing organ much smaller than the wavelength of sound it detects. The MEMS based sensors mimicking the fly's hearing system was fabricated using SOI substrate with 25 micrometer device layer. The sensor was designed to operate around 1.7 kHz, consists of two 1.2 mm × 1.2 mm wings connected in the middle by a 3 mm × 30 micrometer bridge. The entire structure is connected to the substrate by two torsional legs at the center. The sensor operates at its bending resonance frequency and has cosine directional characteristics similar to that of a pressure gradient microphone. For unambiguously determining the direction of sound, two sensors were assembled with a canted angle and outputs of the two sensors were processed to uniquely locate the bearing. At the bending resonant frequency (1.7 kHz) an output voltage of about 25 V/Pa was measured. The uncertainty of the bearing of sound ranged from less than 0.3 degrees close to the normal axis (0 degree) to 3 degrees at the limits of coverage (+/- 60 degrees) based on the 30 degree canted angle used. These findings indicate the potential use of a dual MEMS direction finding sensor assembly to locate sound sources with high accuracy.

  14. Bio-Inspired Miniature Direction Finding Acoustic Sensor.

    PubMed

    Wilmott, Daniel; Alves, Fabio; Karunasiri, Gamani

    2016-07-21

    A narrowband MEMS direction finding sensor has been developed based on the mechanically coupled ears of the Ormia Ochracea fly. The sensor consists of two wings coupled at the middle and attached to a substrate using two legs. The sensor operates at its bending resonance frequency and has cosine directional characteristics similar to that of a pressure gradient microphone. Thus, the directional response of the sensor is symmetric about the normal axis making the determination of the direction ambiguous. To overcome this shortcoming two sensors were assembled with a canted angle similar to that employed in radar bearing locators. The outputs of two sensors were processed together allowing direction finding with no requirement of knowing the incident sound pressure level. At the bending resonant frequency of the sensors (1.69 kHz) an output voltage of about 25 V/Pa was measured. The angle uncertainty of the bearing of sound ranged from less than 0.3° close to the normal axis (0°) to 3.4° at the limits of coverage (±60°) based on the 30° canted angle used. These findings indicate the great potential to use dual MEMS direction finding sensor assemblies to locate sound sources with high accuracy.

  15. Bio-Inspired Miniature Direction Finding Acoustic Sensor

    NASA Astrophysics Data System (ADS)

    Wilmott, Daniel; Alves, Fabio; Karunasiri, Gamani

    2016-07-01

    A narrowband MEMS direction finding sensor has been developed based on the mechanically coupled ears of the Ormia Ochracea fly. The sensor consists of two wings coupled at the middle and attached to a substrate using two legs. The sensor operates at its bending resonance frequency and has cosine directional characteristics similar to that of a pressure gradient microphone. Thus, the directional response of the sensor is symmetric about the normal axis making the determination of the direction ambiguous. To overcome this shortcoming two sensors were assembled with a canted angle similar to that employed in radar bearing locators. The outputs of two sensors were processed together allowing direction finding with no requirement of knowing the incident sound pressure level. At the bending resonant frequency of the sensors (1.69 kHz) an output voltage of about 25 V/Pa was measured. The angle uncertainty of the bearing of sound ranged from less than 0.3° close to the normal axis (0°) to 3.4° at the limits of coverage (±60°) based on the 30° canted angle used. These findings indicate the great potential to use dual MEMS direction finding sensor assemblies to locate sound sources with high accuracy.

  16. Turbulent Fluxes of Suspended Sediment from Coupled Acoustic Doppler Current Profilers

    NASA Astrophysics Data System (ADS)

    Hoitink, T.; Sassi, M.; Vermeulen, B.

    2014-12-01

    Turbulent diffusion is a cornerstone in geophysical fluid mechanics, controlling the exchange of momentum, heat and mass in surface flows occurring in the atmosphere, in rivers and in the ocean. In fluvial and coastal systems, modeling turbulent diffusion of momentum and suspended sediment requires knowledge about turbulent diffusivities, which is generally derived from parameterizations based on laboratory experiments. Field determinations of momentum and sediment diffusivities are cumbersome, requiring an instrumental array to simultaneously sample turbulence and mean flow quantities in time and in space. Recently, a new technique to analyze geophysical surface flow turbulence was introduced, appropriate for large scale systems, based on coupling of acoustic Doppler current profilers (ADCPs). Here, we extend this approach to obtain collocated profiles of both the Reynolds stress tensor and eddy covariance fluxes, to derive vertical profiles of turbulent momentum and sediment diffusivity in a tidal river. Shear and normal stresses are obtained by combining the variances in radial velocities measured by the ADCP beams. The covariances between radial velocities and calibrated acoustic backscatter allow to determine the three Cartesian components of the turbulent flux of suspended sediment. The main advantage of this new approach is that flow velocity and sediment concentration measurements are exactly collocated, and that it allows to profile over longer ranges, in comparison to existing techniques. Results show that vertical profiles of the inverse turbulent Prandtl-Schmidt number is coherent with corresponding profiles of the sediment diffusivity, rather than with profiles of the eddy viscosity. This implies modelling suspended sediment dynamics requires knowledge about the sediment diffusivity, as the Prandtl-Schmidt number cannot be estimated from the eddy viscosity alone.

  17. Synoptic Gulf Stream velocity profiles through simultaneous inversion of hydrographic and acoustic Doppler data

    NASA Technical Reports Server (NTRS)

    Joyce, T. M.; Wunsch, C.; Pierce, S. D.

    1986-01-01

    Data from a shipborne acoustic profiling device have been combined with conductivity, temperature, depth/O2 sections across the Gulf Stream to form estimates of the absolute flow fields. The procedure for the combination was a form of inverse method. The results suggest that at the time of the observations (June 1982) the net Gulf Stream transport off Hatteras was 107 + or - 11 Sv and that across a section near 72.5 W it had increased to 125 + or - 6 Sv. The transport of the deep western boundary current was 9 + or - 3 Sv. For comparison purposes an inversion was done using the hydrographic/O2 data alone as in previously published results and obtained qualitative agreement with the combined inversion. Inversion of the acoustic measurements alone, when corrected for instrument biases, leaves unacceptably large mass transport residuals in the deep water.

  18. Acoustics

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

    The acoustics environment in space operations is important to maintain at manageable levels so that the crewperson can remain safe, functional, effective, and reasonably comfortable. High acoustic levels can produce temporary or permanent hearing loss, or cause other physiological symptoms such as auditory pain, headaches, discomfort, strain in the vocal cords, or fatigue. Noise is defined as undesirable sound. Excessive noise may result in psychological effects such as irritability, inability to concentrate, decrease in productivity, annoyance, errors in judgment, and distraction. A noisy environment can also result in the inability to sleep, or sleep well. Elevated noise levels can affect the ability to communicate, understand what is being said, hear what is going on in the environment, degrade crew performance and operations, and create habitability concerns. Superfluous noise emissions can also create the inability to hear alarms or other important auditory cues such as an equipment malfunctioning. Recent space flight experience, evaluations of the requirements in crew habitable areas, and lessons learned (Goodman 2003; Allen and Goodman 2003; Pilkinton 2003; Grosveld et al. 2003) show the importance of maintaining an acceptable acoustics environment. This is best accomplished by having a high-quality set of limits/requirements early in the program, the "designing in" of acoustics in the development of hardware and systems, and by monitoring, testing and verifying the levels to ensure that they are acceptable.

  19. Acoustic scattering for 3D multi-directional periodic structures using the boundary element method.

    PubMed

    Karimi, Mahmoud; Croaker, Paul; Kessissoglou, Nicole

    2017-01-01

    An efficient boundary element formulation is proposed to solve three-dimensional exterior acoustic scattering problems with multi-directional periodicity. The multi-directional periodic acoustic problem is represented as a multilevel block Toeplitz matrix. By exploiting the Toeplitz structure, the computational time and storage requirements to construct and to solve the linear system of equations arising from the boundary element formulation are significantly reduced. The generalized minimal residual method is implemented to solve the linear system of equations. To efficiently calculate the matrix-vector product in the iterative algorithm, the original matrix is embedded into a multilevel block circulant matrix. A multi-dimensional discrete Fourier transform is then employed to accelerate the matrix-vector product. The proposed approach is applicable to a periodic acoustic problem for any arbitrary shape of the structure in both full space and half space. Two case studies involving sonic crystal barriers are presented. In the first case study, a sonic crystal barrier comprising rigid cylindrical scatterers is modeled. To demonstrate the effectiveness of the proposed technique, periodicity in one, two, or three directions is examined. In the second case study, the acoustic performance of a sonic crystal barrier with locally resonant C-shaped scatterers is studied.

  20. Cause and solution for false upstream boat velocities measured with a StreamPro acoustic doppler current profiler

    USGS Publications Warehouse

    Mueller, David S.; Rehmel, Mike S.; Wagner, Chad R.

    2007-01-01

    In 2003, Teledyne RD Instruments introduced the StreamPro acoustic Doppler current profiler which does not include an internal compass. During stationary moving-bed tests the StreamPro often tends to swim or kite from the end of the tether (the instrument rotates then moves laterally in the direction of the rotation). Because the StreamPro does not have an internal compass, it cannot account for the rotation. This rotation and lateral movement of the StreamPro on the end of the tether generates a false upstream velocity, which cannot be easily distinguished from a moving-bed bias velocity. A field test was completed to demonstrate that this rotation and lateral movement causes a false upstream boat velocity. The vector dot product of the boat velocity and the unit vector of the depth-averaged water velocity is shown to be an effective method to account for the effect of the rotation and lateral movement.

  1. Monaural sound-source-direction estimation using the acoustic transfer function of a parabolic reflection board.

    PubMed

    Takashima, Ryoichi; Takiguchi, Tetsuya; Ariki, Yasuo

    2010-02-01

    This paper presents a sound-source-direction estimation method using only a single microphone with a parabolic reflection board. A simple signal-power-based method using a parabolic antenna has been proposed in the radar field. But the signal-power-based method is not effective for finding the direction of a talking person due to the varying power of the uttered speech signals. In this paper, the sound-source-direction estimation method focuses on the acoustic transfer function instead of the signal power. The use of the parabolic reflection board leads to a difference in the acoustic transfer functions of the target direction and the non-target directions, where the parabolic reflector and its associated microphone rotate together and observe the speech at each angle. The acoustic transfer function is estimated from the observed speech using the statistics of clean speech signals. Its effectiveness has been confirmed by monaural sound-source-direction estimation experiments in a room environment.

  2. Aerodynamic and acoustic investigation of inverted velocity profile coannular exhaust nozzle models and development of aerodynamic and acoustic prediction procedures

    NASA Technical Reports Server (NTRS)

    Larson, R. S.; Nelson, D. P.; Stevens, B. S.

    1979-01-01

    Five co-annular nozzle models, covering a systematic variation of nozzle geometry, were tested statically over a range of exhaust conditions including inverted velocity profile (IVP) (fan to primary stream velocity ratio 1) and non IVP profiles. Fan nozzle pressure ratio (FNPR) was varied from 1.3 to 4.1 at primary nozzle pressure ratios (PNPR) of 1.53 and 2.0. Fan stream temperatures of 700 K (1260 deg R) and 1089 K(1960 deg R) were tested with primary stream temperatures of 700 K (1260 deg R), 811 K (1460 deg R), and 1089 K (1960 deg R). At fan and primary stream velocities of 610 and 427 m/sec (2000 and 1400 ft/sec), respectively, increasing fan radius ratio from 0.69 to 0.83 reduced peak perceived noise level (PNL) 3 dB, and an increase in primary radius ratio from 0 to 0.81 (fan radius ratio constant at 0.83) reduced peak PNL an additional 1.0 dB. There were no noise reductions at a fan stream velocity of 853 m/sec (2800 ft/sec). Increasing fan radius ratio from 0.69 to 0.83 reduced nozzle thrust coefficient 1.2 to 1.5% at a PNPR of 1.53, and 1.7 to 2.0% at a PNPR of 2.0. The developed acoustic prediction procedure collapsed the existing data with standard deviation varying from + or - 8 dB to + or - 7 dB. The aerodynamic performance prediction procedure collapsed thrust coefficient measurements to within + or - .004 at a FNPR of 4.0 and a PNPR of 2.0.

  3. Direct Measurements of Edge Diffraction from Soft Underwater Acoustic Panels

    DTIC Science & Technology

    1994-06-01

    AD- A 2 83 198 UMENTATION PAGE Form Approved rn eu to h ou r P er 0 in~ g d w * ii. fat re wle 0O M B N o . 0 7 0 4 - 1 8 8 = "rt W o00MoG&t of...SPONSORING/MONITORING ]k• •.,(•. t z ,. .•AGENCY REPORT NUMBER OFFICE OF NAVAL RESEARCH 1 AGENC REOR NUM- BOER 800 N. QUINCY ST. WSL 2 - ARLINGTON, VA 22217...kHz. (a) Directly radiated waveform. This waveform was captured with the bydrophone (b) ( O ) situated at the nominal 5-cm oflet positioa however, the

  4. Monitoring glucose in vivo by measuring laser-induced acoustic profiles

    NASA Astrophysics Data System (ADS)

    Bednov, Andrey A.; Karabutov, Alexander A.; Savateeva, Elena V.; March, Wayne F.; Oraevsky, Alexander A.

    2000-05-01

    The optoacoustic method of monitoring absorbed optical energy distribution in tissues was employed to measure changes in glucose concentration in vivo. Glucose osmotic and hydrophilic properties cause reduction of tissue scattering as a result of glucose concentration increase around scattering particles and fibers. The opto-acoustic (OA) method utilizes time-resolved measurements of laser- induced ultrasonic profile in tissue resembling the distribution of absorbed optical energy. This opto-acoustic profile yields effective optical attenuation coefficient, which decreases with decrease of scattering. Glucose effect has been investigated initially in phantoms resembling optical properties of sclera and polystyrene microspheres water solution colored with potassium chromate and then in sclera in vitro and in sclera of live rabbits. The forward mode of opto-acoustic detection was used in the experiments in vitro. Experiments were performed in UV spectral range at the wavelength of (lambda) equals 355-nm. Experimental results demonstrated that an increase in glucose concentration from 5 mM to 60 mM was expressed in the 3 percent reduction of (mu) eff in aqueous solution of polystyrene microspheres. The effect of glucose on sclera in vitro was more prominent and measured as 10 percent reduction of (mu) eff with increase of glucose concentration from 1 mM to 50 mM. It was found that both the amplitude and the profile of OA signal were influenced by mechanical pressure applied to sclera specimen toward the surface of OA transducer. In experiments in live tissue, the backward detection mode was employed, as the only one side access to the tissue surface was available. In experiments in vivo the opto-acoustic profiles were measured in rabbit's sclera before and after intravenous glucose administering. The glucose concentration in rabbit blood was simultaneously measured using commercial device employing chemical analysis of blood. Experimental results demonstrated that a 1

  5. Ice/berm interaction study using rotary sidescan sonar and acoustic profiling systems

    SciTech Connect

    Good, R.R.; Anderson, K.G.; Lanzier, H.H.

    1984-05-01

    Tarsiut Island, in the Canadian Beaufort Sea, was the first dredged caisson retained island built for exploration drilling operations in the Arctic offshore. Due to the island's configuration location, a large first-year ice rubble pile would result from the ice/structure interaction. This paper outlines how a rotary side-scan sonar and a mechanically scanning, narrow-beam acoustic profiling system were used to determine the geometry and the contact area of the underside of heavily rubbled first-year ice. The results of this study are to be used to further the understanding of the nature and mechanism of the ice/structure interaction in Arctic offshore structures.

  6. Field testing of a convergent array of acoustic Doppler profilers for high-resolution velocimetry in energetic tidal currents

    SciTech Connect

    Harding, Samuel F.; Sellar, Brian; Richmond, Marshall C.

    2016-04-25

    An array of single-beam acoustic Doppler profilers has been developed for the high resolution measurement of three-dimensional tidal flow velocities and subsequently tested in an energetic tidal site. This configuration has been developed to increase spatial resolution of velocity measurements in comparison to conventional acoustic Doppler profilers (ADPs) which characteristically use divergent acoustic beams emanating from a single instrument. This is achieved using geometrically convergent acoustic beams creating a sample volume at the focal point of 0.03 m3. Away from the focal point, the array is also able to simultaneously reconstruct three-dimensional velocity components in a profile throughout the water column, and is referred to herein as a convergent-beam acoustic Doppler profiler (C-ADP). Mid-depth profiling is achieved through integration of the sensor platform with the operational commercial-scale Alstom 1MW DeepGen-IV Tidal Turbine deployed at the European Marine Energy Center, Orkney Isles, UK. This proof-of-concept paper outlines the C-ADP system configuration and comparison to measurements provided by co-installed reference instrumentation.

  7. Estimating suspended solids concentrations from backscatter intensity measured by acoustic Doppler current profiler in San Francisco Bay, California

    USGS Publications Warehouse

    Gartner, J.W.

    2004-01-01

    The estimation of mass concentration of suspended solids is one of the properties needed to understand the characteristics of sediment transport in bays and estuaries. However, useful measurements or estimates of this property are often problematic when employing the usual methods of determination from collected water samples or optical sensors. Analysis of water samples tends to undersample the highly variable character of suspended solids, and optical sensors often become useless from biological fouling in highly productive regions. Acoustic sensors, such as acoustic Doppler current profilers that are now routinely used to measure water velocity, have been shown to hold promise as a means of quantitatively estimating suspended solids from acoustic backscatter intensity, a parameter used in velocity measurement. To further evaluate application of this technique using commercially available instruments, profiles of suspended solids concentrations are estimated from acoustic backscatter intensity recorded by 1200- and 2400-kHz broadband acoustic Doppler current profilers located at two sites in San Francisco Bay, California. ADCP backscatter intensity is calibrated using optical backscatterance data from an instrument located at a depth close to the ADCP transducers. In addition to losses from spherical spreading and water absorption, calculations of acoustic transmission losses account for attenuation from suspended sediment and correction for nonspherical spreading in the near field of the acoustic transducer. Acoustic estimates of suspended solids consisting of cohesive and noncohesive sediments are found to agree within about 8-10% (of the total range of concentration) to those values estimated by a second optical backscatterance sensor located at a depth further from the ADCP transducers. The success of this approach using commercially available Doppler profilers provides promise that this technique might be appropriate and useful under certain conditions in

  8. An acoustic doppler current profiler survey of flow velocities in St. Clair River, a connecting channel of the Great Lakes

    USGS Publications Warehouse

    Holtschlag, David J.; Koschik, John A.

    2003-01-01

    Acoustic Doppler current profilers (ADCP) were used to measure flow velocities in St. Clair River during a survey in May and June of 2002, as part of a study to assess the susceptibility of public water intakes to contaminants on the St. Clair-Detroit River Waterway. The survey provides 2.7 million point velocity measurements at 104 cross sections. Sections are spaced about 1,630 ft apart along the river from Port Huron to Algonac, Michigan, a distance of 28.6 miles. Two transects were obtained at each cross section, one in each direction across the river. Along each transect, velocity profiles were obtained 2-4 ft apart. At each velocity profile, average water velocity data were obtained at 1.64 ft intervals of depth. The raw position and velocity data from the ADCP field survey were adjusted for local magnetic anomalies using global positioning system (GPS) measurements at the end points of the transects. The adjusted velocity and ancillary data can be retrieved through the internet and extracted to column-oriented data files.

  9. An acoustic doppler current profiler survey of flow velocities in Detroit River, a connecting channel of the Great Lakes

    USGS Publications Warehouse

    Holtschlag, David J.; Koschik, John A.

    2003-01-01

    Acoustic Doppler current profilers (ADCP) were used to survey flow velocities in Detroit River from July 8-19, 2002, as part of a study to assess the susceptibility of public water intakes to contaminants on the St. Clair-Detroit River Waterway. More than 3.5 million point velocities were measured at 130 cross sections. Cross sections were generally spaced about 1,800 ft apart along the river from the head of Detroit River at the outlet of Lake St. Clair to the mouth of Detroit River on Lake Erie. Two transects were surveyed at each cross section, one in each direction across the river. Along each transect, velocity profiles were generally obtained 0.8-2.2 ft apart. At each velocity profile, average water velocity data were obtained at 1.64 ft intervals of depth. The raw position and velocity data from the ADCP field survey were adjusted for local magnetic anomalies using global positioning system (GPS) measurements at the end points of the transects. The adjusted velocity and ancillary data can be retrieved though the internet and extracted to column-oriented data files.

  10. Mesoscale current fields observed with a shipboard profiling acoustic current meter

    SciTech Connect

    Regier, L.

    1982-08-01

    Measurements of the near-surface currents obtained with a shipboard acoustic current meter during the POLYMODE Local Dynamics Experiment are discussed. The large-scale spatial structure of the directly measured currents is very similar to that obtained from simultaneous hydrographic observations assuming geostrophic dynamics. The vertical shear of geostrophic currents is half that observed directly, and the two are poorly correlated. Vertical shear is dominated by currents having spatial scales shorter than about 180 km and having no geostrophic signature. Although the shear of the ageostrophic component is clearly evident, estimation of the ageostrophic current is hampered by large experimental uncertainties.

  11. Birds adjust acoustic directionality to beam their antipredator calls to predators and conspecifics.

    PubMed

    Yorzinski, Jessica L; Patricelli, Gail L

    2010-03-22

    Animals in many vertebrate species vocalize in response to predators, but it is often unclear whether these antipredator calls function to communicate with predators, conspecifics or both. We evaluated the function of antipredator calls in 10 species of passerines by measuring the acoustic directionality of these calls in response to experimental presentations of a model predator. Acoustic directionality quantifies the radiation pattern of vocalizations and may provide evidence about the receiver of these calls. We predicted that antipredator calls would have a lower directionality if they function to communicate with surrounding conspecifics, and a higher directionality and aimed at the receiver if they function to communicate with the predator. Our results support both of these functions. Overall, the birds produce antipredator calls that have a relatively low directionality, suggesting that the calls radiate in many directions to alert conspecifics. However, birds in some species increase the directionality of their calls when facing the predator. They can even direct their calls towards the predator when facing lateral to it--effectively vocalizing sideways towards the predator. These results suggest that antipredator calls in some species are used to communicate both to conspecifics and to predators, and that birds adjust the directionality of their calls with remarkable sophistication according to the context in which they are used.

  12. Birds adjust acoustic directionality to beam their antipredator calls to predators and conspecifics

    PubMed Central

    Yorzinski, Jessica L.; Patricelli, Gail L.

    2010-01-01

    Animals in many vertebrate species vocalize in response to predators, but it is often unclear whether these antipredator calls function to communicate with predators, conspecifics or both. We evaluated the function of antipredator calls in 10 species of passerines by measuring the acoustic directionality of these calls in response to experimental presentations of a model predator. Acoustic directionality quantifies the radiation pattern of vocalizations and may provide evidence about the receiver of these calls. We predicted that antipredator calls would have a lower directionality if they function to communicate with surrounding conspecifics, and a higher directionality and aimed at the receiver if they function to communicate with the predator. Our results support both of these functions. Overall, the birds produce antipredator calls that have a relatively low directionality, suggesting that the calls radiate in many directions to alert conspecifics. However, birds in some species increase the directionality of their calls when facing the predator. They can even direct their calls towards the predator when facing lateral to it—effectively vocalizing sideways towards the predator. These results suggest that antipredator calls in some species are used to communicate both to conspecifics and to predators, and that birds adjust the directionality of their calls with remarkable sophistication according to the context in which they are used. PMID:19923125

  13. Enhanced Acoustic Black Hole effect in beams with a modified thickness profile and extended platform

    NASA Astrophysics Data System (ADS)

    Tang, Liling; Cheng, Li

    2017-03-01

    The phenomenon of Acoustics Black Hole (ABH) benefits from the bending wave propagating properties inside a thin-walled structure with power-law thickness variation to achieve zero reflection when the structural thickness approaches zero in the ideal scenario. However, manufacturing an ideally tailored power-law profile of a structure with embedded ABH feature can hardly be achieved in practice. Past research showed that the inevitable truncation at the wedge tip of the structure can significantly weaken the expected ABH effect by creating wave reflections. On the premise of the minimum achievable truncation thickness by the current manufacturing technology, exploring ways to ensure and achieve better ABH effect becomes important. In this paper, we investigate this issue by using a previously developed wavelet-decomposed semi-analytical model on an Euler-Bernoulli beam with a modified power-law profile and an extended platform of constant thickness. Through comparisons with the conventional ABH profile in terms of system loss factor and energy distribution, numerical results show that the modified thickness profile brings about a systematic increase in the ABH effect at mid-to-high frequencies, especially when the truncation thickness is small and the profile parameter m is large. The use of an extended platform further increases the ABH effect to broader the frequency band whilst providing rooms for catering particular low frequency applications.

  14. Amplification and directional emission of surface acoustic waves by a two-dimensional electron gas

    SciTech Connect

    Shao, Lei; Pipe, Kevin P.

    2015-01-12

    Amplification of surface acoustic waves (SAWs) by electron drift in a two-dimensional electron gas (2DEG) is analyzed analytically and confirmed experimentally. Calculations suggest that peak power gain per SAW radian occurs at a more practical carrier density for a 2DEG than for a bulk material. It is also shown that SAW emission with tunable directionality can be achieved by modulating a 2DEG's carrier density (to effect SAW generation) in the presence of an applied DC field that amplifies SAWs propagating in a particular direction while attenuating those propagating in the opposite direction.

  15. Preliminary observation of temperature profiles by radio acoustic sounding system (RASS) with a 1280 MHz lower atmospheric wind profiler at Gadanki, India

    NASA Astrophysics Data System (ADS)

    Chandrasekhar Sarma, T. V.; Srinivasulu, P.; Tsuda, T.

    2012-06-01

    A UHF wind profiler operating at 1280 MHz has been developed at NARL for atmospheric studies in the planetary boundary layer. In order to explore application of radio acoustic sounding system (RASS) technique to this profiler, a suitable acoustic attachment was designed and preliminary experiments were conducted on 27-30 August 2010. Height profiles of virtual temperature, Tv, in the planetary boundary layer were derived with 1 μs and 0.25 μs pulse transmission, corresponding to a height resolution of 150 m and about 40 m, respectively. Diurnal variation of Tv is clearly recognized, and perturbations of Tv are also seen in association with a precipitation event. Simultaneous profiles obtained from the MST Radar-RASS and an onsite 50 m tower demonstrate the capability to continuously profile the atmospheric temperature from near the ground to upper tropospheric altitudes.

  16. Long-term horizontal vocal directivity of opera singers: effects of singing projection and acoustic environment.

    PubMed

    Cabrera, Densil; Davis, Pamela J; Connolly, Anna

    2011-11-01

    Vocal directivity refers to how directional the sound is that comes from a singer's mouth, that is, whether the sound is focused into a narrow stream of sound projecting in front of the singers or whether it is spread out all around the singer. This study investigates the long-term vocal directivity and acoustic power of professional opera singers and how these vary among subjects, among singing projections, and among vastly different acoustic environments. The vocal sound of eight professional opera singers (six females and two males) was measured in anechoic and reverberant rooms and in a recital hall. Subjects sang in four different ways: (1) paying great attention to intonation; (2) singing as in performance, with all the emotional connection intended by the composer; (3) imagining a large auditorium; and (4) imagining a small theatre. The same song was sung by all singers in all conditions. A head and torso simulator (HATS), radiating sound from its mouth, was used for comparison in all situations. Results show that individual singers have quite consistent long-term average directivity, even across conditions. Directivity varies substantially among singers. Singers are more directional than the standard HATS (which is a physical model of a talking person). The singer's formant region of the spectrum exhibits greater directivity than the lower-frequency range, and results indicate that singers control directivity (at least, incidentally) for different singing conditions as they adjust the spectral emphasis of their voices through their formants.

  17. Directivity patterns and pulse profiles of ultrasound emitted by laser action on interface between transparent and opaque solids: Analytical theory

    SciTech Connect

    Nikitin, Sergey M. E-mail: vitali.goussev@univ-lemans.fr; Tournat, Vincent; Chigarev, Nikolay; Castagnede, Bernard; Gusev, Vitalyi E-mail: vitali.goussev@univ-lemans.fr; Bulou, Alain; Zerr, Andreas

    2014-01-28

    The analytical theory for the directivity patterns of ultrasounds emitted from laser-irradiated interface between two isotropic solids is developed. It is valid for arbitrary combinations of transparent and opaque materials. The directivity patterns are derived both in two-dimensional and in three-dimensional geometries, by accounting for the specific features of the sound generation by the photo-induced mechanical stresses distributed in the volume, essential in the laser ultrasonics. In particular, the theory accounts for the contribution to the emitted propagating acoustic fields from the converted by the interface evanescent photo-generated compression-dilatation waves. The precise analytical solutions for the profiles of longitudinal and shear acoustic pulses emitted in different directions are proposed. The developed theory can be applied for dimensional scaling, optimization, and interpretation of the high-pressure laser ultrasonics experiments in diamond anvil cell.

  18. Prefrontal cortex and manipulatory go left-go right differentiation to acoustic directional cues in dogs.

    PubMed

    Stepień, I; Stepień, L; Toeplitz, Z

    1975-01-01

    In 20 dogs the manipulatory go left – go right differentiation to acoustic directional cues was elaborated. All dogs received total prefrontal, or dorsolateral (total or partial) or medial (total or partial) cortical ablations. All total ablations markedly affected performance of the task, whereas the partial removals produced moderate or no impairment. Thus, both the dorsolateral and medial prefrontal cortex are involved in this type of differentiation.

  19. Discriminating silt-and-clay from suspended-sand in rivers using side-looking acoustic profilers

    USGS Publications Warehouse

    Wright, Scott A.; Topping, David J.; Williams, Cory A.

    2010-01-01

    techniques rely on measurements of ancillary properties that correlate with suspended-sediment concentration and particle size and thus require the collection of traditional samples for calibration. Through in situ deployments, these methods can provide the high temporal resolution that cannot be achieved through traditional sampling. Here we focus on the evaluation of acoustic profiling techniques (e.g. acoustic-Doppler sideways-looking profilers, or ADPs). One major advantage of acoustic profiling is the ability to concurrently measure water velocity (using Doppler-shift methods) and suspended-sediment concentration such that suspended-sediment flux can be directly computed using data from a single instrument. Acoustic-Doppler profilers have become popular for measuring water velocity and discharge in rivers, through both moving-boat operations and from fixed deployments such as bank-mounted sideways-looking instruments (Hirsch and Costa, 2004, Muste et al., 2007). The method presented herein is most suited to sideways-looking applications as a complement to the "index velocity" technique, whereby an index velocity from a sideways-looking instrument is related to the cross-section average velocity (determined from moving-boat discharge measurements) as a means for developing a continuous water-discharge record (Ruhl and Simpson, 2005). Topping et al. (2007) presented a method for discriminating silt-and-clay from suspended sand, using single frequency ADPs. This method takes advantage of the relations among acoustic backscatter, sediment-induced acoustic attenuation, suspended-sediment concentration (SSC), and particle size distribution (PSD). Backscatter is the amount of sound scattered back and received at the transducer while sediment-induced attenuation is the amount of sound scattered in other directions and absorbed by the sediment particles. Both of these parameters can be measured with an ADP, and their different dependencies on SSC and PSD allow for the

  20. Mastoidectomy dimensions for direct acoustic cochlear implantation: a human cadaveric temporal bone study.

    PubMed

    Fiorino, Francesco; Amadori, Maurizio

    2017-02-28

    The objective of the present paper was to acquire information about the mastoidectomy size necessary to obtain an optimal placement of the direct acoustic cochlear implant actuator and fixation system. Ten human cadaveric temporal bones were dissected and implanted with direct acoustic cochlear implant. Mastoidectomy size was determined after implantation in each temporal bone. A bone bed for the receiver/stimulator, mastoidectomy and a large posterior tympanotomy were drilled out. The mastoidectomy was progressively enlarged posteriorly in small steps until the actuator template was judged adequately oriented to enable passage of the rod through the posterior tympanotomy without any contact with the bony walls. The distance between different landmarks in the mastoidectomy was measured. All measured values showed a high degree of consistency, with limited median absolute deviation values. One of the most critical measure, i.e. the distance between the posterior margin of the mastoidectomy to the superior rim of the bony external ear canal wall, ranged from 13 to 16 mm with a median value of 15 mm. Prior knowledge of the ideal size of the mastoidectomy for direct acoustic cochlear implant facilitates the positioning of the fixation system and may save time during implant surgery.

  1. An evaluation of differences due to changing source directivity in room acoustic computer modeling

    NASA Astrophysics Data System (ADS)

    Vigeant, Michelle C.; Wang, Lily M.

    2001-05-01

    This project examines the effects of changing source directivity in room acoustic computer models on objective parameters and subjective perception. Acoustic parameters and auralizations calculated from omnidirectional versus directional sources were compared. Three realistic directional sources were used, measured in a limited number of octave bands from a piano, singing voice, and violin. A highly directional source that beams only within a sixteenth-tant of a sphere was also tested. Objectively, there were differences of 5% or more in reverberation time (RT) between the realistic directional and omnidirectional sources. Between the beaming directional and omnidirectional sources, differences in clarity were close to the just-noticeable-difference (jnd) criterion of 1 dB. Subjectively, participants had great difficulty distinguishing between the realistic and omnidirectional sources; very few could discern the differences in RTs. However, a larger percentage (32% vs 20%) could differentiate between the beaming and omnidirectional sources, as well as the respective differences in clarity. Further studies of the objective results from different beaming sources have been pursued. The direction of the beaming source in the room is changed, as well as the beamwidth. The objective results are analyzed to determine if differences fall within the jnd of sound-pressure level, RT, and clarity.

  2. Acoustic measurement of suspended sediment concentration profiles in an oscillatory boundary layer

    NASA Astrophysics Data System (ADS)

    Pedocchi, Francisco; García, Marcelo H.

    2012-09-01

    The use of an Ultrasonic Velocity Profiler (UVP) to obtain phase-averaged velocity and turbulent Reynolds stress profiles inside an oscillatory boundary layer flow is described in detail and possible error sources are summarized. Since the instrument also reports the acoustic backscatter, a novel application of the same ultrasound profilers to obtain phase-averaged suspended sediment concentration profiles and the errors involved in this technique are carefully discussed. The experiments were performed in the Large Oscillatory Water-Sediment Tunnel (LOWST), which has been a recent addition to the experimental facilities of the Ven Te Chow Hydrosystems Laboratory at the University of Illinois at Urbana-Champaign. The results showed that for the selected transducer frequency and flow, the instrument ability to characterize turbulence is compromised by the presence of Doppler noise and the size of the sampling volume. Regarding the suspended sediment estimation, it was found that the calibration obtained using water samples yielded good results, allowing for the study of the suspended sediment evolution along the oscillation.

  3. Typing DNA profiles from previously enhanced fingerprints using direct PCR.

    PubMed

    Templeton, Jennifer E L; Taylor, Duncan; Handt, Oliva; Linacre, Adrian

    2017-07-01

    Fingermarks are a source of human identification both through the ridge patterns and DNA profiling. Typing nuclear STR DNA markers from previously enhanced fingermarks provides an alternative method of utilising the limited fingermark deposit that can be left behind during a criminal act. Dusting with fingerprint powders is a standard method used in classical fingermark enhancement and can affect DNA data. The ability to generate informative DNA profiles from powdered fingerprints using direct PCR swabs was investigated. Direct PCR was used as the opportunity to generate usable DNA profiles after performing any of the standard DNA extraction processes is minimal. Omitting the extraction step will, for many samples, be the key to success if there is limited sample DNA. DNA profiles were generated by direct PCR from 160 fingermarks after treatment with one of the following dactyloscopic fingerprint powders: white hadonite; silver aluminium; HiFi Volcano silk black; or black magnetic fingerprint powder. This was achieved by a combination of an optimised double-swabbing technique and swab media, omission of the extraction step to minimise loss of critical low-template DNA, and additional AmpliTaq Gold(®) DNA polymerase to boost the PCR. Ninety eight out of 160 samples (61%) were considered 'up-loadable' to the Australian National Criminal Investigation DNA Database (NCIDD). The method described required a minimum of working steps, equipment and reagents, and was completed within 4h. Direct PCR allows the generation of DNA profiles from enhanced prints without the need to increase PCR cycle numbers beyond manufacturer's recommendations. Particular emphasis was placed on preventing contamination by applying strict protocols and avoiding the use of previously used fingerprint brushes. Based on this extensive survey, the data provided indicate minimal effects of any of these four powders on the chance of obtaining DNA profiles from enhanced fingermarks. Copyright © 2017

  4. Back-end algorithms that enhance the functionality of a biomimetic acoustic gunfire direction finding system

    NASA Astrophysics Data System (ADS)

    Pu, Yirong; Kelsall, Sarah; Ziph-Schatzberg, Leah; Hubbard, Allyn

    2009-05-01

    Increasing battlefield awareness can improve both the effectiveness and timeliness of response in hostile military situations. A system that processes acoustic data is proposed to handle a variety of possible applications. The front-end of the existing biomimetic acoustic direction finding system, a mammalian peripheral auditory system model, provides the back-end system with what amounts to spike trains. The back-end system consists of individual algorithms tailored to extract specific information. The back-end algorithms are transportable to FPGA platforms and other general-purpose computers. The algorithms can be modified for use with both fixed and mobile, existing sensor platforms. Currently, gunfire classification and localization algorithms based on both neural networks and pitch are being developed and tested. The neural network model is trained under supervised learning to differentiate and trace various gunfire acoustic signatures and reduce the effect of different frequency responses of microphones on different hardware platforms. The model is being tested against impact and launch acoustic signals of various mortars, supersonic and muzzle-blast of rifle shots, and other weapons. It outperforms the cross-correlation algorithm with regard to computational efficiency, memory requirements, and noise robustness. The spike-based pitch model uses the times between successive spike events to calculate the periodicity of the signal. Differences in the periodicity signatures and comparisons of the overall spike activity are used to classify mortar size and event type. The localization of the gunfire acoustic signals is further computed based on the classification result and the location of microphones and other parameters of the existing hardware platform implementation.

  5. Effects of spatially correlated acoustic-tactile information on judgments of auditory circular direction

    NASA Astrophysics Data System (ADS)

    Cohen, Annabel J.; Lamothe, M. J. Reina; Toms, Ian D.; Fleming, Richard A. G.

    2002-05-01

    Cohen, Lamothe, Fleming, MacIsaac, and Lamoureux [J. Acoust. Soc. Am. 109, 2460 (2001)] reported that proximity governed circular direction judgments (clockwise/counterclockwise) of two successive tones emanating from all pairs of 12 speakers located at 30-degree intervals around a listeners' head (cranium). Many listeners appeared to experience systematic front-back confusion. Diametrically opposed locations (180-degrees-theoretically ambiguous direction) produced a direction bias pattern resembling Deutsch's tritone paradox [Deutsch, Kuyper, and Fisher, Music Percept. 5, 7992 (1987)]. In Experiment 1 of the present study, the circular direction task was conducted in the tactile domain using 12 circumcranial points of vibration. For all 5 participants, proximity governed direction (without front-back confusion) and a simple clockwise bias was shown for 180-degree pairs. Experiment 2 tested 9 new participants in one unimodal auditory condition and two bimodal auditory-tactile conditions (spatially-correlated/spatially-uncorrelated). Correlated auditory-tactile information eliminated front-back confusion for 8 participants and replaced the ``paradoxical'' bias for 180-degree pairs with the clockwise bias. Thus, spatially correlated audio-tactile location information improves the veridical representation of 360-degree acoustic space, and modality-specific principles are implicated by the unique circular direction bias patterns for 180-degree pairs in the separate auditory and tactile modalities. [Work supported by NSERC.

  6. Acoustic Doppler Current Profiler Measurements in the Tailrace at John Day Dam

    SciTech Connect

    Cook, Chris B.; Dibrani, Berhon; Serkowski, John A.; Richmond, Marshall C.; Titzler, P. Scott; Dennis, Gary W.

    2006-01-30

    Acoustic Doppler current profilers (ADCPs) were used to measure water velocities in the tailrace at John Day Dam over a two-week period in February 2005. Data were collected by the Pacific Northwest National Laboratory for the Hydraulic Design Section, Portland District, U.S. Army Corps of Engineers (USACE). The objective of this project was therefore to collect field measurements of water velocities in the near-field draft tube exit zone as well as the far-field tailrace to be used for improving these models. Field data were collected during the project using five separate ADCPs. Mobile ADCP data were collected using two ADCPs mounted on two separate boats. Data were collected by either holding the boat on-station at pre-defined locations for approximately 10 minutes or in moving transect mode when the boat would move over large distances during the data collection. Results from the mobile ADCP survey indicated a complex hydrodynamic flow field in the tailrace downstream of John Day Dam. A large gyre was noted between the skeleton section of the powerhouse and non-spilling portion of the spillway. Downstream of the spillway, the spillway flow is constrained against the navigation lock guide wall, and large velocities were noted in this region. Downstream of the guide wall, velocities decreased as the spillway jet dispersed. Near the tailrace island, the flow split was measured to be approximately equal on Day 2 (25.4 kcfs spillway/123 kcfs total). However, approximately 60% of the flow passed along the south shore of the island on Day 1 (15.0 kcfs spillway/150 kcfs total). At a distance of 9000 ft downstream of the dam, flows had equalized laterally and were generally uniform over the cross section. The collection of water velocities near the draft tube exit of an operating turbine unit is not routine, and equipment capable of measuring 3D water velocities in these zones are at the forefront of hydraulic measurement technology. Although the feasibility of

  7. Acoustic source signal and directivity for explosive sources in complex environments

    NASA Astrophysics Data System (ADS)

    Waxler, R.; Bonner, J. L.; Reinke, R.; Talmadge, C. L.; Kleinert, D. E.; Alberts, W.; Lennox, E.

    2012-12-01

    Much work has gone into characterizing the blast wave, and ultimate acoustic pulse, produced by an explosion in flat, open land. Recently, an experiment was performed to study signals produced by explosions in more complex environments, both above and below ground. Explosive charges, ranging in weight from 200 to 2000 lbs., were detonated in a variety of configurations in and around tubes and culverts as well as buried in alluvium and limestone. A large number of acoustic sensors were deployed to capture the signals from the explosions. The deployment included two concentric rings of eighteen sensors each, spaced roughly every twenty degrees at radii of 300 and 1000 meters and surrounding the explosions. These captured the acoustic source function and directivity. In addition, a network of sensors, including sensors mounted on an aerostat and elevated to 300 meters altitude, were deployed throughout the area to capture the signals as they propagated. The meteorological state was monitored with a variety of instruments including a tethersonde, radiosonde and sodar. Significant directivity was observed in the signals from many of the shots, including those from charges that were detonated underground, but not near any structure. Results from the experiment will be presented.

  8. Acoustic and aerodynamic performance investigation of inverted velocity profile coannular plug nozzles. [variable cycle engines

    NASA Technical Reports Server (NTRS)

    Knott, P. R.; Blozy, J. T.; Staid, P. S.

    1981-01-01

    The results of model scale parametric static and wind tunnel aerodynamic performance tests on unsuppressed coannular plug nozzle configurations with inverted velocity profile are discussed. The nozzle configurations are high-radius-ratio coannular plug nozzles applicable to dual-stream exhaust systems typical of a variable cycle engine for Advanced Supersonic Transport application. In all, seven acoustic models and eight aerodynamic performance models were tested. The nozzle geometric variables included outer stream radius ratio, inner stream to outer stream ratio, and inner stream plug shape. When compared to a conical nozzle at the same specific thrust, the results of the static acoustic tests with the coannular nozzles showed noise reductions of up to 7 PNdB. Extensive data analysis showed that the overall acoustic results can be well correlated using the mixed stream velocity and the mixed stream density. Results also showed that suppression levels are geometry and flow regulation dependent with the outer stream radius ratio, inner stream-to-outer stream velocity ratio and inner stream velocity ratio and inner stream plug shape, as the primary suppression parameters. In addition, high-radius ratio coannular plug nozzles were found to yield shock associated noise level reductions relative to a conical nozzle. The wind tunnel aerodynamic tests showed that static and simulated flight thrust coefficient at typical takeoff conditions are quite good - up to 0.98 at static conditions and 0.974 at a takeoff Mach number of 0.36. At low inner stream flow conditions significant thrust loss was observed. Using an inner stream conical plug resulted in 1% to 2% higher performance levels than nozzle geometries using a bent inner plug.

  9. Direct Numerical Simulation of Acoustic Noise Generation from the Nozzle Wall of a Hypersonic Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Huang, Junji; Duan, Lian; Choudhari, Meelan M.

    2017-01-01

    The acoustic radiation from the turbulent boundary layer on the nozzle wall of a Mach 6 Ludwieg Tube is simulated using Direct Numerical Simulations (DNS), with the flow conditions falling within the operational range of the Mach 6 Hypersonic Ludwieg Tube, Braunschweig (HLB). The mean and turbulence statistics of the nozzle-wall boundary layer show good agreement with those predicted by Pate's correlation and Reynolds Averaged Navier-Stokes (RANS) computations. The rms pressure fluctuation P'(rms)/T(w) plateaus in the freestream core of the nozzle. The intensity of the freestream noise within the nozzle is approximately 20% higher than that radiated from a single at pate with a similar freestream Mach number, potentially because of the contributions to the acoustic radiation from multiple azimuthal segments of the nozzle wall.

  10. Per-survivor processing for underwater acoustic communications with direct-sequence spread spectrum.

    PubMed

    Xu, Xiaoka; Zhou, Shengli; Morozov, Andrey K; Preisig, James C

    2013-05-01

    This paper proposes a receiver for direct-sequence spread spectrum transmissions in underwater acoustic channels, which combines a per-survivor processing (PSP) structure with sparse channel estimation. Specifically, the PSP structure establishes the trellis on the symbol level to render a small to moderate number of states, thus reducing the computational complexity. Meanwhile, the sparse channel estimation is performed on the chip level, where the orthogonal matching pursuit algorithm is used and a two-dimensional grid of path delay and Doppler scaling factor is incorporated in the dictionary construction. The effective combination of the PSP detection and sparse channel estimation achieves a good tradeoff between performance and complexity. Simulation and experiment results show that the proposed receiver outperforms the conventional RAKE receiver considerably, and most importantly, the proposed PSP receiver with an exact wideband dictionary maintains an excellent performance even for challenging underwater acoustic channels with large Doppler disparities on different paths.

  11. The development of a biomimetic acoustic direction finding system for use on multiple platforms

    NASA Astrophysics Data System (ADS)

    Deligeorges, Socrates; Anderson, David; Browning, Cassandra A.; Cohen, Howard; Freedman, David; Gore, Tyler; Karl, Christian; Kelsall, Sarah; Mountain, David; Nourzad, Marianne; Pu, Yirong; Sandifer, Matt; Xue, Shuwan; Ziph-Schatzberg, Leah; Hubbard, Allyn

    2008-04-01

    This paper describes the flow of scientific and technological achievements beginning with a stationary "small, smart, biomimetic acoustic processor" designed for DARPA that led to a program aimed at acoustic characterization and direction finding for multiple, mobile platforms. ARL support and collaboration has allowed us to adapt the core technology to multiple platforms including a Packbot robotic platform, a soldier worn platform, as well as a vehicle platform. Each of these has varying size and power requirements, but miniaturization is an important component of the program for creating practical systems which we address further in companion papers. We have configured the system to detect and localize gunfire and tested system performance with live fire from numerous weapons such as the AK47, the Dragunov, and the AR15. The ARL-sponsored work has led to connections with Natick Labs and the Future Force Warrior program, and in addition, the work has many and obvious applications to homeland defense, police, and civilian needs.

  12. A New Surgical Approach for Direct Acoustic Cochlear Implant: A Temporal Bone Study

    PubMed Central

    Bruschini, Luca; Forli, Francesca; Vito, Andrea De; Berrettini, Stefano

    2016-01-01

    Objectives The direct acoustic cochlear implant (DACI) is among the latest developments in the field of implantable acoustic prostheses. The surgical procedure requires a mastoidectomy and a posterior-inferior tympanotomy, with access to the facial recess at the level of the oval window, in a complex and lengthy surgical approach. Here, we report a new and considerably shorter surgical approach. Methods The new approach involves positioning of artificial incus above the oval window through the superior-anterior tympanotomy. We performed DACI placement in temporal bone specimens (n=5) to assess the feasibility of the new approach. Results The average time for the DACI implant in the temporal bones was only 112 minutes (range, 94 to 142 minutes) and there was little clinical risk associated with the procedure. Access was easy and drilling was minimal. Conclusion Our approach simplified the surgical procedure and consequently reduced the time required for DACI placement. PMID:27334513

  13. Measuring discharge with acoustic Doppler current profilers from a moving boat

    USGS Publications Warehouse

    Mueller, David S.; Wagner, Chad R.; Rehmel, Michael S.; Oberg, Kevin A.; Rainville, Francois

    2013-01-01

    The use of acoustic Doppler current profilers (ADCPs) from a moving boat is now a commonly used method for measuring streamflow. The technology and methods for making ADCP-based discharge measurements are different from the technology and methods used to make traditional discharge measurements with mechanical meters. Although the ADCP is a valuable tool for measuring streamflow, it is only accurate when used with appropriate techniques. This report presents guidance on the use of ADCPs for measuring streamflow; this guidance is based on the experience of U.S. Geological Survey employees and published reports, papers, and memorandums of the U.S. Geological Survey. The guidance is presented in a logical progression, from predeployment planning, to field data collection, and finally to post processing of the collected data. Acoustic Doppler technology and the instruments currently (2013) available also are discussed to highlight the advantages and limitations of the technology. More in-depth, technical explanations of how an ADCP measures streamflow and what to do when measuring in moving-bed conditions are presented in the appendixes. ADCP users need to know the proper procedures for measuring discharge from a moving boat and why those procedures are required, so that when the user encounters unusual field conditions, the procedures can be adapted without sacrificing the accuracy of the streamflow-measurement data.

  14. Averaged indicators of secondary flow in repeated acoustic Doppler current profiler crossings of bends

    USGS Publications Warehouse

    Dinehart, R.L.; Burau, J.R.

    2005-01-01

    [1] Cross-stream velocity was measured in a large river bend at high spatial resolution over three separate survey episodes. A suite of methods for resolving cross-stream velocity distributions was tested on data collected using acoustic Doppler current profilers (ADCP) in the sand-bedded Sacramento River, California. The bend was surveyed with repeated ADCP crossings at eight cross sections during a rising limb of high discharge in February 2004 and twice on recession in March 2004. By translating and interpolating repeated ADCP crossings to planar grids, velocity ensembles at similar positions along irregular boat paths could be averaged. The averaging minimized turbulent fluctuations in streamwise velocities over 1 m/s, enabling the resolution of weaker cross-stream velocities (???15-30 cm/s). Secondary-flow influence on suspended sediment was inferred from a lateral region of acoustic backscatter intensity aligned with outward flow over the point bar. A near-bed decrease in backscatter intensity across the pool corresponded with inward cross-stream flow. These suspension indicators were used to orient averaged velocity grids for unambiguously defining the cross-stream velocity magnitudes. Additional field investigations could test whether the correlation between cross-stream velocity and backscatter intensity patterns results from helical recirculation of suspended sediment to the inside of the bend. These river measurements, consistent with classic and recent laboratory studies, show that ADCP surveys can provide refined views of secondary flow and sediment movement in large rivers.

  15. Discharge measurements using a broad-band acoustic Doppler current profiler

    USGS Publications Warehouse

    Simpson, Michael R.

    2002-01-01

    The measurement of unsteady or tidally affected flow has been a problem faced by hydrologists for many years. Dynamic discharge conditions impose an unreasonably short time constraint on conventional current-meter discharge-measurement methods, which typically last a minimum of 1 hour. Tidally affected discharge can change more than 100 percent during a 10-minute period. Over the years, the U.S. Geological Survey (USGS) has developed moving-boat discharge-measurement techniques that are much faster but less accurate than conventional methods. For a bibliography of conventional moving-boat publications, see Simpson and Oltmann (1993, page 17). The advent of the acoustic Doppler current profiler (ADCP) made possible the development of a discharge-measurement system capable of more accurately measuring unsteady or tidally affected flow. In most cases, an ADCP discharge-measurement system is dramatically faster than conventional discharge-measurement systems, and has comparable or better accuracy. In many cases, an ADCP discharge-measurement system is the only choice for use at a particular measurement site. ADCP systems are not yet ?turnkey;? they are still under development, and for proper operation, require a significant amount of operator training. Not only must the operator have a rudimentary knowledge of acoustic physics, but also a working knowledge of ADCP operation, the manufacturer's discharge-measurement software, and boating techniques and safety.

  16. Measurement of Turbulence with Acoustic Doppler Current Profilers - Sources of Error and Laboratory Results

    USGS Publications Warehouse

    Nystrom, E.A.; Oberg, K.A.; Rehmann, C.R.; ,

    2002-01-01

    Acoustic Doppler current profilers (ADCPs) provide a promising method for measuring surface-water turbulence because they can provide data from a large spatial range in a relatively short time with relative ease. Some potential sources of errors in turbulence measurements made with ADCPs include inaccuracy of Doppler-shift measurements, poor temporal and spatial measurement resolution, and inaccuracy of multi-dimensional velocities resolved from one-dimensional velocities measured at separate locations. Results from laboratory measurements of mean velocity and turbulence statistics made with two pulse-coherent ADCPs in 0.87 meters of water are used to illustrate several of inherent sources of error in ADCP turbulence measurements. Results show that processing algorithms and beam configurations have important effects on turbulence measurements. ADCPs can provide reasonable estimates of many turbulence parameters; however, the accuracy of turbulence measurements made with commercially available ADCPs is often poor in comparison to standard measurement techniques.

  17. A GIS-based Computational Tool for Multidimensional Flow Velocity by Acoustic Doppler Current Profilers

    NASA Astrophysics Data System (ADS)

    Kim, D.; Winkler, M.; Muste, M.

    2015-06-01

    Acoustic Doppler Current Profilers (ADCPs) provide efficient and reliable flow measurements compared to other tools for characteristics of the riverine environments. In addition to originally targeted discharge measurements, ADCPs are increasingly utilized to assess river flow characteristics. The newly developed VMS (Velocity Mapping Software) aims at providing an efficient process for quality assurance, mapping velocity vectors for visualization and facilitating comparison with physical and numerical model results. VMS was designed to provide efficient and smooth work flows for processing groups of transects. The software allows the user to select group of files and subsequently to conduct statistical and graphical quality assurance on the files as a group or individually as appropriate. VMS also enables spatial averaging in horizontal and vertical plane for ADCP data in a single or multiple transects over the same or consecutive cross sections. The analysis results are displayed in numerical and graphical formats.

  18. Variance of discharge estimates sampled using acoustic Doppler current profilers from moving boats

    USGS Publications Warehouse

    Garcia, Carlos M.; Tarrab, Leticia; Oberg, Kevin; Szupiany, Ricardo; Cantero, Mariano I.

    2012-01-01

    This paper presents a model for quantifying the random errors (i.e., variance) of acoustic Doppler current profiler (ADCP) discharge measurements from moving boats for different sampling times. The model focuses on the random processes in the sampled flow field and has been developed using statistical methods currently available for uncertainty analysis of velocity time series. Analysis of field data collected using ADCP from moving boats from three natural rivers of varying sizes and flow conditions shows that, even though the estimate of the integral time scale of the actual turbulent flow field is larger than the sampling interval, the integral time scale of the sampled flow field is on the order of the sampling interval. Thus, an equation for computing the variance error in discharge measurements associated with different sampling times, assuming uncorrelated flow fields is appropriate. The approach is used to help define optimal sampling strategies by choosing the exposure time required for ADCPs to accurately measure flow discharge.

  19. Comparison of shipboard acoustic Doppler current profiler and moored current measurements in the Equatorial Pacific

    NASA Technical Reports Server (NTRS)

    Chereskin, T. K.; Regier, L. A.; Halpern, D.

    1987-01-01

    Depth-averaged current shears computed from shipboard acoustic Doppler current profiler (ADCP) and moored Savonius rotor and vane vector-averaging current meter (VACM) measurements are compared at 35, 62.5, 100 and 140 m depths within 7 km of each other near 0 deg, 140 deg W during a 12-day interval in November 1984. The agreement between the VACM and ADCP shears was excellent. The average root-mean-square difference of hourly shear values was small, approximately 0.0021/s, and the average correlation coefficient was 0.90. Spectral estimates were equivalent to within a 95 percent significance level and the VACM and ADCP shears were 95 percent statistically coherent with zero phase difference for frequencies below 0.2 cycles per hour.

  20. Use of an Acoustic Doppler Current Profiler (ADCP) to Measure Hypersaline Bidirectional Discharge

    USGS Publications Warehouse

    Johnson, K.K.; Loving, B.L.; ,

    2002-01-01

    The U.S. Geological Survey measures the exchange of flow between the north and south parts of Great Salt Lake, Utah, as part of a monitoring program. Turbidity and bidirectional flow through the breach in the causeway that divides the lake into two parts makes it difficult to measure discharge with conventional streamflow techniques. An acoustic Doppler current profiler (ADCP) can be used to more accurately define the angles of flow and the location of the interface between the layers of flow. Because of the high salinity levels measured in Great Salt Lake (60-280 parts per thousand), special methods had to be developed to adjust ADCP-computed discharges for the increased speed of sound in hypersaline waters and for water entrained at the interface between flow layers.

  1. DNA profiles from clothing fibers using direct PCR.

    PubMed

    Blackie, Renée; Taylor, Duncan; Linacre, Adrian

    2016-09-01

    We report on the successful use of direct PCR amplification of single fibers from items of worn clothing. Items of clothing were worn throughout the course of a day, with the individual commencing regular activities. Single fibers were taken from the cuff of the clothing at regular intervals and amplified directly. The same areas were subjected to tape-lifting, and also amplified directly for comparison. The NGM™ kit that amplifies 15 STR loci plus amelogenin was used. A total of 35 single fiber samples were processed and analyzed from five items of clothing, with 81 % of samples returning a profile of 14 alleles or more. All tape-lift samples amplified directly produced DNA profiles of 15 alleles or more. The aim was to develop a simple, operational method that could be used routinely in forensic science casework and that has the potential to generate more complete profiles, which would not be detected using standard extraction methods on this type of sample. For ease of implementation, the process also adheres to standard methods with no increase in the cycle number.

  2. Application of acoustic doppler current profilers for measuring three-dimensional flow fields and as a surrogate measurement of bedload transport

    USGS Publications Warehouse

    Conaway, J.S.

    2005-01-01

    Acoustic Doppler current profilers (ADCPs) have been in use in the riverine environment for nearly 20 years. Their application primarily has been focused on the measurement of streamflow discharge. ADCPs emit high-frequency sound pulses and receive reflected sound echoes from sediment particles in the water column. The Doppler shift between transmitted and return signals is resolved into a velocity component that is measured in three dimensions by simultaneously transmitting four independent acoustical pulses. To measure the absolute velocity magnitude and direction in the water column, the velocity magnitude and direction of the instrument must also be computed. Typically this is accomplished by ensonifying the streambed with an acoustical pulse that also provides a depth measurement for each of the four acoustic beams. Sediment transport on or near the streambed will bias these measurements and requires external positioning such as a differentially corrected Global Positioning Systems (GPS). Although the influence of hydraulic structures such as spur dikes and bridge piers is typically only measured and described in one or two dimensions, the use of differentially corrected GPS with ADCPs provides a fully three-dimensional measurement of the magnitude and direction of the water column at such structures. The measurement of these flow disturbances in a field setting also captures the natural pulsations of river flow that cannot be easily quantified or modeled by numerical simulations or flumes. Several examples of measured three-dimensional flow conditions at bridge sites throughout Alaska are presented. The bias introduced to the bottom-track measurement is being investigated as a surrogate measurement of bedload transport. By fixing the position of the ADCP for a known period of time the apparent velocity of the streambed at that position can be determined. Initial results and comparison to traditionally measured bedload values are presented. These initial

  3. Two Years of Industrial Experience in the Use of a Small, Direct Field Acoustic Chamber

    NASA Astrophysics Data System (ADS)

    Saggini, Nicola; Di Pietro, Vincenzo; Poulain, Nicolas; Herzog, Philippe

    2012-07-01

    Within Thales Alenia Space - Italy small satellite Assembly Integration and Test (AIT) plant, the need to develop a suitable facility for spacecraft acoustic noise test has arisen, with additional constraints posed by the necessity of a low impact on the existing building layout, low cost of procurement and operations, while maintaining a high reliability of the system for a theoretical maximum throughput of one test per week over an extended period of time, e.g. six months. The needs have been answered by developing a small (~40 m3 test volume), direct field (DF A T) acoustic test chamber, christened “Alpha Cabin”, where noise generation is achieved by means of commercial audio drivers equipped with custom enclosures. The paper starts with a brief presentation of the main characteristics of the system, but then concentrates on the lessons learnt and return of experience from the tests conducted in more than two years of continuous use. Starting from test article structural responses and their comparison with reverberant chambers, properties of the acoustic field and their implications on the former are analyzed.

  4. In situ Probe Microphone Measurement for Testing the Direct Acoustical Cochlear Stimulator.

    PubMed

    Stieger, Christof; Alnufaily, Yasser H; Candreia, Claudia; Caversaccio, Marco D; Arnold, Andreas M

    2017-01-01

    Hypothesis: Acoustical measurements can be used for functional control of a direct acoustic cochlear stimulator (DACS). Background: The DACS is a recently released active hearing implant that works on the principle of a conventional piston prosthesis driven by the rod of an electromagnetic actuator. An inherent part of the DACS actuator is a thin titanium diaphragm that allows for movement of the stimulation rod while hermetically sealing the housing. In addition to mechanical stimulation, the actuator emits sound into the mastoid cavity because of the motion of the diaphragm. Methods: We investigated the use of the sound emission of a DACS for intra-operative testing. We measured sound emission in the external auditory canal (PEAC) and velocity of the actuators stimulation rod (Vact) in five implanted ears of whole-head specimens. We tested the influence various positions of the loudspeaker and a probe microphone on PEAC and simulated implant malfunction in one example. Results: Sound emission of the DACS with a signal-to-noise ratio >10 dB was observed between 0.5 and 5 kHz. Simulated implant misplacement or malfunction could be detected by the absence or shift in the characteristic resonance frequency of the actuator. PEAC changed by <6 dB for variations of the microphone and loudspeaker position. Conclusion: Our data support the feasibility of acoustical measurements for in situ testing of the DACS implant in the mastoid cavity as well as for post-operative monitoring of actuator function.

  5. In situ Probe Microphone Measurement for Testing the Direct Acoustical Cochlear Stimulator

    PubMed Central

    Stieger, Christof; Alnufaily, Yasser H.; Candreia, Claudia; Caversaccio, Marco D.; Arnold, Andreas M.

    2017-01-01

    Hypothesis: Acoustical measurements can be used for functional control of a direct acoustic cochlear stimulator (DACS). Background: The DACS is a recently released active hearing implant that works on the principle of a conventional piston prosthesis driven by the rod of an electromagnetic actuator. An inherent part of the DACS actuator is a thin titanium diaphragm that allows for movement of the stimulation rod while hermetically sealing the housing. In addition to mechanical stimulation, the actuator emits sound into the mastoid cavity because of the motion of the diaphragm. Methods: We investigated the use of the sound emission of a DACS for intra-operative testing. We measured sound emission in the external auditory canal (PEAC) and velocity of the actuators stimulation rod (Vact) in five implanted ears of whole-head specimens. We tested the influence various positions of the loudspeaker and a probe microphone on PEAC and simulated implant malfunction in one example. Results: Sound emission of the DACS with a signal-to-noise ratio >10 dB was observed between 0.5 and 5 kHz. Simulated implant misplacement or malfunction could be detected by the absence or shift in the characteristic resonance frequency of the actuator. PEAC changed by <6 dB for variations of the microphone and loudspeaker position. Conclusion: Our data support the feasibility of acoustical measurements for in situ testing of the DACS implant in the mastoid cavity as well as for post-operative monitoring of actuator function. PMID:28860963

  6. Acoustic Magnetic Resonance Investigations Utilizing Direct, Backward Wave, and SQUID Detection.

    NASA Astrophysics Data System (ADS)

    Mozurkewich, George, Jr.

    Acoustic magnetic resonance investigations were undertaken utilizing three distinct methods of detection. (1) In direct detection, increased ultrasonic attenuation due to resonant absorption is monitored directly. (2) In backward wave spectroscopy, resonant absorption introduces ultrasonic nonlinearities which generate a backward propagating wave. The amplitude of the resulting echo reflects the resonant susceptibility. (3) In SQUID detection, which is proposed here for the first time, changes in the magnetization of the spin system are detected using a superconducting quantum interference device. Using direct detection, nuclear acoustic resonance of ('183)W in metallic tungsten has been observed for the first time. Because ('183)W is isotopically dilute (14%) and has a small gyromagnetic ratio (179 Hz/G), the predicted dipolar linewidth is only 0.10 G. The observed, inhomogenously broadened lineshape (0.44 G peak to peak, with additional structure on the high field side) is attributed to spatial variation of the sample's demagnetizing field. Theoretical fits to the lineshape are calculated and discussed. The Knight shift is (1.0397 (+OR-) 0.0026)%. The neutral acceptor in indium doped silicon was examined using the recently developed technique of backward wave phonon spectroscopy. The high power results show multiple quantum transitions and a broad background feature which peaks near 2T and extends beyond 8T (spectrometer frequency = 6 GHz). It is shown that the background signal arises largely from transitions between Kramers doublets at sites with static strain of order 100 (mu)eV. In addition, a new interface phenomenon, the enhanced backward wave, is described. A new method of detection of acoustic magnetic resonance, using a SQUID magnetometer, is proposed. An attempt to realize such a detection system did not succeed. Reasons for the failure are analyzed, and design modifications are suggested. A SQUID detection system should be valuable for very weak

  7. Direct Acoustic Stimulation at the Lateral Canal: An Alternative Route to the Inner Ear?

    PubMed

    Verhaert, Nicolas; Walraevens, Joris; Desloovere, Christian; Wouters, Jan; Gérard, Jean-Marc

    2016-01-01

    Severe to profound mixed hearing loss is associated with hearing rehabilitation difficulties. Recently, promising results for speech understanding were obtained with a direct acoustic cochlear implant (DACI). The surgical implantation of a DACI with standard coupling through a stapedotomy can however be regarded as challenging. Therefore, in this experimental study, the feasibility of direct acoustic stimulation was investigated at an anatomically and surgically more accessible inner ear site. DACI stimulation of the intact, blue-lined and opened lateral semicircular canal (LC) was investigated and compared with standard oval window (OW) coupling. Additionally, stapes footplate fixation was induced. Round window (RW) velocity, as a measure of the performance of the device and its coupling efficiency, was determined in fresh-frozen human cadaver heads. Using single point laser Doppler vibrometry, RW velocity could reliably be measured in low and middle frequency range, and equivalent sound pressure level (LE) output was calculated. Results for the different conditions obtained in five heads were analyzed in subsequent frequency ranges. Comparing the difference in RW membrane velocity showed higher LE in the LC opened condition [mean: 103 equivalent dB SPL], than in LC intact or blue-lined conditions [63 and 74 equivalent dB SPL, respectively]. No difference was observed between the LC opened and the standard OW condition. Inducing stapes fixation, however, led to a difference in the low frequency range of LE compared to LC opened. In conclusion, this feasibility study showed promising results for direct acoustic stimulation at this specific anatomically and surgically more accessible inner ear site. Future studies are needed to address the impact of LC stimulation on cochlear micromechanics and on the vestibular system like dizziness and risks of hearing loss.

  8. Direct Acoustic Stimulation at the Lateral Canal: An Alternative Route to the Inner Ear?

    PubMed Central

    Walraevens, Joris; Desloovere, Christian; Wouters, Jan; Gérard, Jean-Marc

    2016-01-01

    Severe to profound mixed hearing loss is associated with hearing rehabilitation difficulties. Recently, promising results for speech understanding were obtained with a direct acoustic cochlear implant (DACI). The surgical implantation of a DACI with standard coupling through a stapedotomy can however be regarded as challenging. Therefore, in this experimental study, the feasibility of direct acoustic stimulation was investigated at an anatomically and surgically more accessible inner ear site. DACI stimulation of the intact, blue-lined and opened lateral semicircular canal (LC) was investigated and compared with standard oval window (OW) coupling. Additionally, stapes footplate fixation was induced. Round window (RW) velocity, as a measure of the performance of the device and its coupling efficiency, was determined in fresh-frozen human cadaver heads. Using single point laser Doppler vibrometry, RW velocity could reliably be measured in low and middle frequency range, and equivalent sound pressure level (LE) output was calculated. Results for the different conditions obtained in five heads were analyzed in subsequent frequency ranges. Comparing the difference in RW membrane velocity showed higher LE in the LC opened condition [mean: 103 equivalent dB SPL], than in LC intact or blue-lined conditions [63 and 74 equivalent dB SPL, respectively]. No difference was observed between the LC opened and the standard OW condition. Inducing stapes fixation, however, led to a difference in the low frequency range of LE compared to LC opened. In conclusion, this feasibility study showed promising results for direct acoustic stimulation at this specific anatomically and surgically more accessible inner ear site. Future studies are needed to address the impact of LC stimulation on cochlear micromechanics and on the vestibular system like dizziness and risks of hearing loss. PMID:27500399

  9. Comment on "Reconstructing surface wave profiles from reflected acoustic pulses" [J. Acoust. Soc. Am. 133(5), 2597-2611 (2013)].

    PubMed

    Choo, Youngmin; Song, H C

    2016-05-01

    A computationally efficient, time-domain Helmholtz-Kirchhoff (H-K) integral was derived and applied to reconstructing surface wave profiles from reflected acoustic pulses [Walstead and Deane, J. Acoust. Soc. Am. 133, 2597-2611 (2013)]. However, the final form of the integral equation incorporating a stationary phase approximation contained a complex phase term exp(iπ/4), which cannot be treated as a simple time delay. In this work, a real time-domain H-K integral is presented that includes an additional Hilbert transform of the time-derivative of the transmitted pulse. Numerical simulation with a sinusoidal surface shows good agreement between the real time-domain formulation and exact H-K integral, while achieving a significant improvement in computational speed (e.g., 2 orders of magnitude).

  10. An Examination of the Relationship Between Electroglottographic Contact Quotient, Electroglottographic Decontacting Phase Profile, and Acoustical Spectral Moments.

    PubMed

    Awan, Shaheen N; Krauss, Andrew R; Herbst, Christian T

    2015-09-01

    To date, only a few studies have examined the possible relationship between electroglottographic (EGG) data and spectral characteristics of the voice. This study examined the possible association between EGG signal data (contact quotient [CQ] and decontacting phase profile) and spectral moments of the acoustic signal (spectral mean, spectral standard deviation (SD), spectral skewness, and spectral kurtosis). Furthermore, the possible effects of gender on these measurements were analyzed. Sustained vowel /ɑ/ productions were obtained from 48 normophonic individuals (24 adult males and 24 adult females). The central 1-second portions of the acoustic vowel samples were analyzed for spectral moments, and the EGG signal was analyzed for CQ (CQEGG), fundamental frequency (F0), and decontacting phase profile. Across all subjects, the spectral characteristics of the voice (in particular, spectral SD, skewness, and kurtosis) are significantly related to changes in the relative duration of vocal fold contact (as measured via CQEGG). In addition, significant effects of the profile of the EGG decontacting phase (ie, concave down/"knee" vs concave up/"no knee") on spectral SD were also observed, as well as a strong trend for decontacting phase profile to influence the spectral mean. Although the degree of vocal fold contact and differences in decontacting phase profile may have an influence on the spectral characteristics of the acoustic voice signal, the strength of correlations between CQEGG values and measures of spectral moments only accounted for approximately 13-16% of the variation in spectral distribution characteristics. These results stress the importance of the transformative role of the supraglottal vocal tract in producing an acoustic output that maintains some of the characteristics of the glottal source, but which modifies the source characteristics in ways not completely accounted for by single parameters such as CQEGG or EGG profile. Copyright © 2015 The

  11. Field evaluation of shallow-water acoustic doppler current profiler discharge measurements

    USGS Publications Warehouse

    Rehmel, M.S.

    2007-01-01

    In 2004, the U.S. Geological Survey (USGS) Office of Surface Water staff and USGS Water Science employees began testing the StreamPro, an acoustic Doppler current profiler (ADCP) for shallow-water discharge measurements. Teledyne RD Instruments introduced the StreamPro in December of 2003. The StreamPro is designed to make a "moving boat" discharge measurement in streams with depths between 0.15 and 2 m. If the StreamPro works reliably in these conditions, it will allow for use of ADCPs in a greater number of streams than previously possible. Evaluation sites were chosen to test the StreamPro over a range of conditions. Simultaneous discharge measurements with mechanical and other acoustic meters, along with stable rating curves at established USGS streamflow-gaging stations, were used for comparisons. The StreamPro measurements ranged in mean velocity from 0.076 to 1.04 m/s and in discharge from 0.083 m 3/s to 43.4 m 3/s. Tests indicate that discharges measured with the StreamPro compare favorably to the discharges measured with the other meters when the mean channel velocity is greater than 0.25 m/s. When the mean channel velocity is less than 0.25 m/s, the StreamPro discharge measurements for individual transects have greater variability than those StreamPro measurements where the mean channel velocity is greater than 0.25 m/s. Despite this greater variation in individual transects, there is no indication that the StreamPro measured discharges (the mean discharge for all transects) are biased, provided that enough transects are used to determine the mean discharge. ?? 2007 ASCE.

  12. Extraction of tidal streams from a ship-borne acoustic Doppler current profiler using a statistical-dynamical model

    NASA Astrophysics Data System (ADS)

    Dowd, Michael; Thompson, Keith R.

    1996-04-01

    We present a method for extracting the barotropic tide directly from the time-space series of horizontal velocity obtained by a ship-borne acoustic Doppler current profiler (ADCP). The method is conceptually straightforward, easy to implement, and suitable for operational use. It involves fitting a limited area tidal model, based on the linearized depth-averaged shallow water equations, to the ADCP record. The flows across the open boundaries of the model domain are assumed periodic in time with known frequencies corresponding to the tidal constituents of interest. The unknown tidal amplitudes and phases at the boundary are estimated from interior ADCP velocities using an inverse method; the solution of the shallow water equations is posed as a boundary value problem in the frequency domain, and the estimation procedure is based on generalized least squares regression. Results obtained include tidal maps, a tidal residual series, and associated error estimates. An application of the method to ship ADCP data collected on a cruise to the Western Bank region of the Scotian Shelf off the east coast of Canada is described. The tidal estimates and the residual field obtained are verified by comparison to other data collected during the cruise. The residual circulation shows an anticyclonic gyre centered on the crest of Western Bank and a northward current to the west of this region.

  13. A modified beam-to-earth transformation to measure short-wavelength internal waves with an acoustic Doppler current profiler

    USGS Publications Warehouse

    Scotti, A.; Butman, B.; Beardsley, R.C.; Alexander, P.S.; Anderson, S.

    2005-01-01

    The algorithm used to transform velocity signals from beam coordinates to earth coordinates in an acoustic Doppler current profiler (ADCP) relies on the assumption that the currents are uniform over the horizontal distance separating the beams. This condition may be violated by (nonlinear) internal waves, which can have wavelengths as small as 100-200 m. In this case, the standard algorithm combines velocities measured at different phases of a wave and produces horizontal velocities that increasingly differ from true velocities with distance from the ADCP. Observations made in Massachusetts Bay show that currents measured with a bottom-mounted upward-looking ADCP during periods when short-wavelength internal waves are present differ significantly from currents measured by point current meters, except very close to the instrument. These periods are flagged with high error velocities by the standard ADCP algorithm. In this paper measurements from the four spatially diverging beams and the backscatter intensity signal are used to calculate the propagation direction and celerity of the internal waves. Once this information is known, a modified beam-to-earth transformation that combines appropriately lagged beam measurements can be used to obtain current estimates in earth coordinates that compare well with pointwise measurements. ?? 2005 American Meteorological Society.

  14. Estimation of suspended sediment concentration from Acoustic Doppler Current Profiler (ADCP) instrument: A case study of Lembeh Strait, North Sulawesi

    NASA Astrophysics Data System (ADS)

    Dwinovantyo, Angga; Manik, Henry M.; Prartono, Tri; Susilohadi; Ilahude, Delyuzar

    2017-01-01

    Measurement of suspended sediment concentration (SSC) is one of the parameters needed to determine the characteristics of sediment transport. However, the measurement of SSC nowadays still uses conventional technique and it has limitations; especially in temporal resolution. With advanced technology, the measurement can use hydroacoustic technology such as Acoustic Doppler Current Profiler (ADCP). ADCP measures the intensity of backscatter as echo intensity unit from sediment particles. The frequency of ADCP used in this study was 400 kHz. The samples were measured and collected from Lembeh Strait, North Sulawesi. The highest concentration of suspended sediment was 98.89 mg L-1 and the lowest was 45.20 mg L-1. Time series data showed the tidal condition affected the SSC. From the research, we also made correction from sound signal losses effect such as spherical spreading and sound absorption to get more accurate results by eliminating these parameters in echo intensity data. Simple linear regression analysis at echo intensity measured from ADCP to direct measurement of SSC was performed to obtain the estimation of the SSC. The comparison result of estimation of SSC from ADCP measurements and SSC from laboratory analyses was insignificantly different based on t-test statistical analysis with 95% confidence interval percentage.

  15. Tokamak profile prediction using direct gyrokinetic and neoclassical simulation

    SciTech Connect

    Candy, J.; Waltz, R. E.; Belli, E.; Holland, C.; Fahey, M. R.

    2009-06-15

    Tokamak transport modeling scenarios, including ITER [ITER Physics Basis Editors, Nucl. Fusion 39, 2137 (1999)] performance predictions, are based exclusively on reduced models for core thermal and particle transport. The reason for this is simple: computational cost. A typical modeling scenario may require the evaluation of thousands of individual transport fluxes (local transport models calculate the energy and particle fluxes across a specified flux surface given fixed profiles). Despite continuous advances in direct gyrokinetic simulation, the cost of an individual simulation remains so high that direct gyrokinetic transport calculations have been avoided. By developing a steady-state iteration scheme suitable for direct gyrokinetic and neoclassical simulations, we can now compute steady-state temperature profiles for DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] plasmas given known plasma sources. The new code, TGYRO, encapsulates the GYRO[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] code, for turbulent transport, and the NEO[E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 50, 095010 (2008)] code, for kinetic neoclassical transport. Results for DIII-D L-mode discharge 128913 are given, with computational and experimental results consistent in the region 0{<=}r/a{<=}0.8.

  16. Tokamak profile prediction using direct gyrokinetic and neoclassical simulation

    SciTech Connect

    Candy, Jeff; Holland, Chris; Waltz, R. E.; Fahey, Mark R; Belli, E

    2009-01-01

    okamak transport modeling scenarios, including ITER ITER Physics Basis Editors, Nucl. Fusion 39, 2137 1999 performance predictions, are based exclusively on reduced models for core thermal and particle transport. The reason for this is simple: computational cost. A typical modeling scenario may require the evaluation of thousands of individual transport fluxes local transport models calculate the energy and particle fluxes across a specified flux surface given fixed profiles . Despite continuous advances in direct gyrokinetic simulation, the cost of an individual simulation remains so high that direct gyrokinetic transport calculations have been avoided. By developing a steady-state iteration scheme suitable for direct gyrokinetic and neoclassical simulations, we can now compute steady-state temperature profiles for DIII-D J. L. Luxon, Nucl. Fusion 42, 614 2002 plasmas given known plasma sources. The new code, TGYRO, encapsulates the GYRO J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 2003 code, for turbulent transport, and the NEO E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 50, 095010 2008 code, for kinetic neoclassical transport. Results for DIII-D L-mode discharge 128913 are given, with computational and experimental results consistent in the region 0 <= r/a <= 0.8.

  17. Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech

    PubMed Central

    Leong, Victoria; Goswami, Usha

    2015-01-01

    When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes). Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM) patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH) model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS). Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, ~2 Hz), syllables (Syllable AM, ~5 Hz) and onset-rime units (Phoneme AM, ~20 Hz). We argue that these AM patterns could in principle be used by naïve listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words), syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72–82% (freely-read CDS) and 90–98% (rhythmically-regular CDS) stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP) theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across

  18. Acoustic-Emergent Phonology in the Amplitude Envelope of Child-Directed Speech.

    PubMed

    Leong, Victoria; Goswami, Usha

    2015-01-01

    When acquiring language, young children may use acoustic spectro-temporal patterns in speech to derive phonological units in spoken language (e.g., prosodic stress patterns, syllables, phonemes). Children appear to learn acoustic-phonological mappings rapidly, without direct instruction, yet the underlying developmental mechanisms remain unclear. Across different languages, a relationship between amplitude envelope sensitivity and phonological development has been found, suggesting that children may make use of amplitude modulation (AM) patterns within the envelope to develop a phonological system. Here we present the Spectral Amplitude Modulation Phase Hierarchy (S-AMPH) model, a set of algorithms for deriving the dominant AM patterns in child-directed speech (CDS). Using Principal Components Analysis, we show that rhythmic CDS contains an AM hierarchy comprising 3 core modulation timescales. These timescales correspond to key phonological units: prosodic stress (Stress AM, ~2 Hz), syllables (Syllable AM, ~5 Hz) and onset-rime units (Phoneme AM, ~20 Hz). We argue that these AM patterns could in principle be used by naïve listeners to compute acoustic-phonological mappings without lexical knowledge. We then demonstrate that the modulation statistics within this AM hierarchy indeed parse the speech signal into a primitive hierarchically-organised phonological system comprising stress feet (proto-words), syllables and onset-rime units. We apply the S-AMPH model to two other CDS corpora, one spontaneous and one deliberately-timed. The model accurately identified 72-82% (freely-read CDS) and 90-98% (rhythmically-regular CDS) stress patterns, syllables and onset-rime units. This in-principle demonstration that primitive phonology can be extracted from speech AMs is termed Acoustic-Emergent Phonology (AEP) theory. AEP theory provides a set of methods for examining how early phonological development is shaped by the temporal modulation structure of speech across

  19. Repeated surveys by acoustic Doppler current profiler for flow and sediment dynamics in a tidal river

    USGS Publications Warehouse

    Dinehart, R.L.; Burau, J.R.

    2005-01-01

    A strategy of repeated surveys by acoustic Doppler current profiler (ADCP) was applied in a tidal river to map velocity vectors and suspended-sediment indicators. The Sacramento River at the junction with the Delta Cross Channel at Walnut Grove, California, was surveyed over several tidal cycles in the Fall of 2000 and 2001 with a vessel-mounted ADCP. Velocity profiles were recorded along flow-defining survey paths, with surveys repeated every 27 min through a diurnal tidal cycle. Velocity vectors along each survey path were interpolated to a three-dimensional Cartesian grid that conformed to local bathymetry. A separate array of vectors was interpolated onto a grid from each survey. By displaying interpolated vector grids sequentially with computer animation, flow dynamics of the reach could be studied in three-dimensions as flow responded to the tidal cycle. Velocity streamtraces in the grid showed the upwelling of flow from the bottom of the Sacramento River channel into the Delta Cross Channel. The sequential display of vector grids showed that water in the canal briefly returned into the Sacramento River after peak flood tides, which had not been known previously. In addition to velocity vectors, ADCP data were processed to derive channel bathymetry and a spatial indicator for suspended-sediment concentration. Individual beam distances to bed, recorded by the ADCP, were transformed to yield bathymetry accurate enough to resolve small bedforms within the study reach. While recording velocity, ADCPs also record the intensity of acoustic backscatter from particles suspended in the flow. Sequential surveys of backscatter intensity were interpolated to grids and animated to indicate the spatial movement of suspended sediment through the study reach. Calculation of backscatter flux through cross-sectional grids provided a first step for computation of suspended-sediment discharge, the second step being a calibrated relation between backscatter intensity and sediment

  20. Repeated surveys by acoustic Doppler current profiler for flow and sediment dynamics in a tidal river

    NASA Astrophysics Data System (ADS)

    Dinehart, R. L.; Burau, J. R.

    2005-11-01

    A strategy of repeated surveys by acoustic Doppler current profiler (ADCP) was applied in a tidal river to map velocity vectors and suspended-sediment indicators. The Sacramento River at the junction with the Delta Cross Channel at Walnut Grove, California, was surveyed over several tidal cycles in the Fall of 2000 and 2001 with a vessel-mounted ADCP. Velocity profiles were recorded along flow-defining survey paths, with surveys repeated every 27 min through a diurnal tidal cycle. Velocity vectors along each survey path were interpolated to a three-dimensional Cartesian grid that conformed to local bathymetry. A separate array of vectors was interpolated onto a grid from each survey. By displaying interpolated vector grids sequentially with computer animation, flow dynamics of the reach could be studied in three-dimensions as flow responded to the tidal cycle. Velocity streamtraces in the grid showed the upwelling of flow from the bottom of the Sacramento River channel into the Delta Cross Channel. The sequential display of vector grids showed that water in the canal briefly returned into the Sacramento River after peak flood tides, which had not been known previously. In addition to velocity vectors, ADCP data were processed to derive channel bathymetry and a spatial indicator for suspended-sediment concentration. Individual beam distances to bed, recorded by the ADCP, were transformed to yield bathymetry accurate enough to resolve small bedforms within the study reach. While recording velocity, ADCPs also record the intensity of acoustic backscatter from particles suspended in the flow. Sequential surveys of backscatter intensity were interpolated to grids and animated to indicate the spatial movement of suspended sediment through the study reach. Calculation of backscatter flux through cross-sectional grids provided a first step for computation of suspended-sediment discharge, the second step being a calibrated relation between backscatter intensity and sediment

  1. Ultra-directional source of longitudinal acoustic waves based on a two-dimensional solid/solid phononic crystal

    SciTech Connect

    Morvan, B.; Tinel, A.; Sainidou, R.; Rembert, P.; Vasseur, J. O.; Hladky-Hennion, A.-C.; Swinteck, N.; Deymier, P. A.

    2014-12-07

    Phononic crystals (PC) can be used to control the dispersion properties of acoustic waves, which are essential to direct their propagation. We use a PC-based two-dimensional solid/solid composite to demonstrate experimentally and theoretically the spatial filtering of a monochromatic non-directional wave source and its emission in a surrounding water medium as an ultra-directional beam with narrow angular distribution. The phenomenon relies on square-shaped equifrequency contours (EFC) enabling self-collimation of acoustic waves within the phononic crystal. Additionally, the angular width of collimated beams is controlled via the EFC size-shrinking when increasing frequency.

  2. Velocity profiles, Reynolds stresses and bed roughness from an autonomous field deployed Acoustic Doppler Velocity Profiler in a mixed sediment tidal estuary

    NASA Astrophysics Data System (ADS)

    O'Boyle, Louise; Thorne, Peter; Cooke, Richard; Cohbed Team

    2014-05-01

    Estuaries are among some of the most important global landscapes in terms of population density, ecology and economy. Understanding the dynamics of these natural mixed sediment environments is of particular interest amid growing concerns over sea level rise, climate variations and estuarine response to these changes. Many predictors exist for bed form formation and sand transport in sandy coastal zones; however less work has been published on mixed sediments. This paper details a field study which forms part of the COHBED project aiming to increase understanding of bed forms in a biotic mixed sediment estuarine environment. The study was carried out in the Dee Estuary, in the eastern Irish Sea between England and Wales from the 21st May to 4th June 2013. A state of the art instrumentation frame, known as SEDbed, was deployed at three sites of differing sediment properties and biological makeup within the intertidal zone of the estuary. The SEDbed deployment consisted of a suite of optical and acoustic instrumentation, including an Acoustic Doppler Velocity Profiler (ADVP), Acoustic Doppler Velocimeter (ADV) and a three dimensional acoustic ripple profiler, 3D-ARP. Supplementary field samples and measurements were recorded alongside the frame during each deployment. This paper focuses on the use of new technological developments for the investigation of sediment dynamics. The hydrodynamics at each of the deployment sites are presented including centimetre resolution velocity profiles in the near bed region of the water column, obtained from the ADVP, which is presently the only autonomous field deployed coherent Doppler profiler . Based on these high resolution profiles variations in frictional velocity, bed shear stress and roughness length are calculated. Comparisons are made with theoretical models and with Reynolds stress values obtained from ADV data at a single point within the ADVP profile and from ADVP data itself. Predictions of bed roughness at each

  3. Unexpected acoustic stimulation during action preparation reveals gradual re-specification of movement direction.

    PubMed

    Marinovic, Welber; Tresilian, James; Chapple, Jack L; Riek, Stephan; Carroll, Timothy J

    2017-04-21

    A loud acoustic stimulus (LAS) is often used as a tool to investigate motor preparation in simple reaction time (RT) tasks, where all movement parameters are known in advance. In this report, we used a LAS to examine direction specification in simple and choice RT tasks. This allowed us to investigate how the specification of movement direction unfolds during the preparation period. In two experiments, participants responded to the appearance of an imperative stimulus (IS) with a ballistic wrist force directed toward one of two targets. In probe trials, a LAS (120dBa) was delivered around the time of IS presentation. In Experiment 1, RTs in the simple RT task were faster when the LAS was presented, but the effect on the movement kinematics was negligible. In the Choice RT task, however, movement direction variability increased when the LAS was presented. In Experiment 2, when we primed movements toward one direction, our analyses revealed that the longer participants took to start a movement, the more accurate their responses became. Our results show not only that movement direction reprogramming occurs quickly and continuously, but also that LAS can be a valuable tool to obtain meaningful readouts of the motor system's preparatory state. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  4. Acoustic-Phonetic Differences between Infant- and Adult-Directed Speech: The Role of Stress and Utterance Position

    ERIC Educational Resources Information Center

    Wang, Yuanyuan; Seidl, Amanda; Cristia, Alejandrina

    2015-01-01

    Previous studies have shown that infant-directed speech (IDS) differs from adult-directed speech (ADS) on a variety of dimensions. The aim of the current study was to investigate whether acoustic differences between IDS and ADS in English are modulated by prosodic structure. We compared vowels across the two registers (IDS, ADS) in both stressed…

  5. Acoustic-Phonetic Differences between Infant- and Adult-Directed Speech: The Role of Stress and Utterance Position

    ERIC Educational Resources Information Center

    Wang, Yuanyuan; Seidl, Amanda; Cristia, Alejandrina

    2015-01-01

    Previous studies have shown that infant-directed speech (IDS) differs from adult-directed speech (ADS) on a variety of dimensions. The aim of the current study was to investigate whether acoustic differences between IDS and ADS in English are modulated by prosodic structure. We compared vowels across the two registers (IDS, ADS) in both stressed…

  6. Experimental evaluation of long-range acoustic sensing using super-directivity speaker and super-resolution signal processing with pulse compression technique

    NASA Astrophysics Data System (ADS)

    Asakura, Yuya; Okubo, Kan; Tagawa, Norio

    2017-07-01

    Acoustic sensing technology in air is a promising method for acquiring the shape and/or position of a target. Universal and smart technology, however, cannot be sufficiently established because of various acoustic environmental noises, attenuation effect, and so forth. To overcome this problem, in this study, we propose acoustic sensing that combines a super-directivity speaker and super-resolution signal processing. Our experimental results suggest that the proposed method enables long-range high-resolution acoustic imaging.

  7. Direct-to-PCR tissue preservation for DNA profiling.

    PubMed

    Sorensen, Amy; Berry, Clare; Bruce, David; Gahan, Michelle Elizabeth; Hughes-Stamm, Sheree; McNevin, Dennis

    2016-05-01

    Disaster victim identification (DVI) often occurs in remote locations with extremes of temperatures and humidities. Access to mortuary facilities and refrigeration are not always available. An effective and robust DNA sampling and preservation procedure would increase the probability of successful DNA profiling and allow faster repatriation of bodies and body parts. If the act of tissue preservation also released DNA into solution, ready for polymerase chain reaction (PCR), the DVI process could be further streamlined. In this study, we explored the possibility of obtaining DNA profiles without DNA extraction, by adding aliquots of preservative solutions surrounding fresh human muscle and decomposing human muscle and skin tissue samples directly to PCR. The preservatives consisted of two custom preparations and two proprietary solutions. The custom preparations were a salt-saturated solution of dimethyl sulfoxide (DMSO) with ethylenediaminetetraacetic (EDTA) and TENT buffer (Tris, EDTA, NaCl, Tween 20). The proprietary preservatives were DNAgard (Biomatrica(®)) and Tissue Stabilising Kit (DNA Genotek). We obtained full PowerPlex(®) 21 (Promega) and GlobalFiler(®) (Life Technologies) DNA profiles from fresh and decomposed tissue preserved at 35 °C for up to 28 days for all four preservatives. The preservative aliquots removed from the fresh muscle tissue samples had been stored at -80 °C for 4 years, indicating that long-term archival does not diminish the probability of successful DNA typing. Rather, storage at -80 °C seems to reduce PCR inhibition.

  8. Direct experimental investigations of acoustic modes guided by a solid{endash}solid interface using optical interferometry

    SciTech Connect

    Matteie, C.; Jia, X.; Quentin, G.

    1997-09-01

    This paper presents direct field measurements of acoustic modes guided by the interface between two transparent solids. The measurement technique is based on the acousto-optical interaction inside the solid between the acoustic field and the probe laser beam of an interferometer. The main advantage of the method is its ability to measure acoustic strain fields in areas of difficult access with the classic detection methods. Moreover, it gives complete information about the dilatation strain field inside the solid, e.g., amplitude and phase. The propagation of a real velocity mode (Stoneley wave) is first illustrated. Then the situation of complex velocity modes is investigated for a Plexiglas{endash}fused quartz slip interface. This material combination supports two possible interface modes theoretically. These modes are simultaneously observed and the differences between their behavior are measured. {copyright} {ital 1997 Acoustical Society of America.}

  9. Acoustic communication in the Greater Sage-Grouse (Centrocercus urophasianus) an examination into vocal sacs, sound propagation, and signal directionality

    NASA Astrophysics Data System (ADS)

    Dantzker, Marc Steven

    The thesis is an inquiry into the acoustic communication of a very unusual avian species, the Greater Sage-Grouse, Centrocercus urophasianus. One of the most outstanding features of this animal's dynamic mating display is its use of paired air sacs that emerge explosively from an esophageal pouch. My first line of inquiry into this system is a review of the form and function of similar vocal apparatuses, collectively called vocal sacs, in birds. Next, with a combination of mathematical models and field measurements, My collaborator and I investigate the acoustic environment where the Greater Sage-Grouse display. The complexities of this acoustic environment are relevant both to the birds and to the subsequent examinations of the display's properties. Finally, my collaborators and I examine a cryptic component of the acoustic display --- directionality --- which we measured simultaneously from multiple locations around free moving grouse on their mating grounds.

  10. Method of monaural localization of the acoustic source direction from the standpoint of the active perception theory

    NASA Astrophysics Data System (ADS)

    Gai, V. E.; Polyakov, I. V.; Krasheninnikov, M. S.; Koshurina, A. A.; Dorofeev, R. A.

    2017-01-01

    Currently, the scientific and educational center of the “Transport” of NNSTU performs work on the creation of the universal rescue vehicle. This vehicle is a robot, and intended to reduce the number of human victims in accidents on offshore oil platforms. An actual problem is the development of a method for determining the location of a person overboard in low visibility conditions, when a traditional vision is not efficient. One of the most important sensory robot systems is the acoustic sensor system, because it is omnidirectional and does not require finding of an acoustic source in visibility scope. Features of the acoustic sensor robot system can complement the capabilities of the video sensor in the solution of the problem of localization of a person or some event in the environment. This paper describes the method of determination of the direction of the acoustic source using just one microphone. The proposed method is based on the active perception theory.

  11. Performance assessment and calibration of a profiling lab-scale acoustic Doppler velocimeter for application over mixed sand-gravel beds

    USDA-ARS?s Scientific Manuscript database

    Acoustic Doppler velocimetry has made high-resolution turbulence measurements in sediment-laden flows possible. Recent developments have resulted in a commercially available lab-scale acoustic Doppler profiling device, a Nortek Vectrino II, that allows for three-dimensional velocity data to be colle...

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

    SciTech Connect

    Kim, H.S.; Flagg, C.N.; Shi, Y.

    1996-12-01

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

  13. Modeling streamflow from coupled airborne laser scanning and acoustic Doppler current profiler data

    USGS Publications Warehouse

    Norris, Lam; Kean, Jason W.; Lyon, Steve

    2016-01-01

    The rating curve enables the translation of water depth into stream discharge through a reference cross-section. This study investigates coupling national scale airborne laser scanning (ALS) and acoustic Doppler current profiler (ADCP) bathymetric survey data for generating stream rating curves. A digital terrain model was defined from these data and applied in a physically based 1-D hydraulic model to generate rating curves for a regularly monitored location in northern Sweden. Analysis of the ALS data showed that overestimation of the streambank elevation could be adjusted with a root mean square error (RMSE) block adjustment using a higher accuracy manual topographic survey. The results of our study demonstrate that the rating curve generated from the vertically corrected ALS data combined with ADCP data had lower errors (RMSE = 0.79 m3/s) than the empirical rating curve (RMSE = 1.13 m3/s) when compared to streamflow measurements. We consider these findings encouraging as hydrometric agencies can potentially leverage national-scale ALS and ADCP instrumentation to reduce the cost and effort required for maintaining and establishing rating curves at gauging station sites similar to the Röån River.

  14. The investigation of sediment processes in rivers by means of the Acoustic Doppler Profiler

    NASA Astrophysics Data System (ADS)

    Guerrero, M.

    2014-09-01

    The measurement of sediment processes at the scale of a river cross-section is desirable for the evaluation of many issues related to river hydro-morphodynamics, such as the calibration and validation of numerical models for predicting the climate change impacts on water resources and efforts of maintenance of the navigation channel and other hydraulic works. Suspended- and bed-load have traditionally been measured by cumbersome techniques that are difficult to apply in large rivers. The acoustics for the investigation of small-scale sedimentological processes gained acceptance in the marine community because of its ability to simultaneously profile sediment concentration and size distribution, non-intrusively, and with high temporal and spatial resolution. The application of these methods in true riverine case studies presents additional difficulties, mainly related to water depths and stream currents that limit sound propagation into water and challenge the instruments deployment, especially during floods. This article introduces the motivations for using the ADCP for sediment processes investigation other than for flow discharge measurement, summarizes the developed methods and indicates future desirable improvements. In addition, an application on the Po River in Italy is presented, focusing on the calibration of the existing software by means of ADCP recordings. The calibrated model will assist in planning the dredging activities to maintain the navigation channel and the intake of a pump station for irrigation that is periodically obstructed with a sandbar.

  15. Disentangling preference ratings of concert hall acoustics using subjective sensory profiles.

    PubMed

    Lokki, Tapio; Pätynen, Jukka; Kuusinen, Antti; Tervo, Sakari

    2012-11-01

    Subjective evaluation of acoustics was studied by recording nine concert halls with a simulated symphony orchestra on a seat 12 m from the orchestra. The recorded music was spatially reproduced for subjective listening tests and individual vocabulary profiling. In addition, the preferences of the assessors and objective parameters were gathered. The results show that concert halls were discriminated using perceptual characteristics, such as Envelopment/Loudness, Reverberance, Bassiness, Proximity, Definition, and Clarity. With these perceptual dimensions the preference ratings can be explained. Seventeen assessors were divided into two groups based on their preferences. The first group preferred concert halls with relatively intimate sound, in which it is quite easy to hear individual instruments and melody lines. In contrast, the second group preferred a louder and more reverberant sound with good envelopment and strong bass. Even though all halls were recorded exactly at the same distance, the preference is best explained with subjective Proximity and with Bassiness, Envelopment, and Loudness to some extent. Neither the preferences nor the subjective ratings could be fully explained by objective parameters (ISO3382-1:2009), although some correlations were found.

  16. Correcting acoustic Doppler current profiler discharge measurements biased by sediment transport

    USGS Publications Warehouse

    Mueller, D.S.; Wagner, C.R.

    2007-01-01

    A negative bias in discharge measurements made with an acoustic Doppler current profiler (ADCP) is attributed to the movement of sediment on or near the streambed, and is an issue widely acknowledged by the scientific community. The integration of a differentially corrected global positioning system (DGPS) to track the movement of the ADCP can be used to avoid the systematic bias associated with a moving bed. DGPS, however, cannot provide consistently accurate positions because of multipath errors and satellite signal reception problems on waterways with dense tree canopy along the banks, in deep valleys or canyons, and near bridges. An alternative method of correcting for the moving-bed bias, based on the closure error resulting from a two-way crossing of the river, is presented. The uncertainty in the mean moving-bed velocity measured by the loop method is shown to be approximately 0.6cm/s. For the 13 field measurements presented, the loop method resulted in corrected discharges that were within 5% of discharges measured utilizing DGPS to compensate for moving-bed conditions. ?? 2007 ASCE.

  17. Coupling airborne laser scanning and acoustic Doppler current profiler data to model stream rating curves

    NASA Astrophysics Data System (ADS)

    Lam, N.; Lyon, S. W.; Kean, J. W.

    2015-12-01

    The rating curve enables the translation of water depth into discharge through a reference cross section. Errors in estimating stream channel geometry can therefore result in increased discharge uncertainty. This study investigates coupling national-scale airborne laser scanning (ALS) and acoustic Doppler current profiler (ADCP) bathymetric survey data for generating stream rating curves. Specifically, stream channel geometries were generated from coupled ALS and ADCP scanning data collected for a well-monitored site located in northern Sweden. These data were used to define the hydraulic geometry required by a physically-based 1-D hydraulic model. The results of our study demonstrate that the effects of potential scanning data errors on the model generated rating curve were less than the uncertainties due to stream gauging measurements and empirical rating curve fitting. Further analysis of the ALS data showed that an overestimation of the streambank elevation (the main scanning data error) was primarily due to vegetation that could be adjusted for through a root-mean-square-error bias correction. We consider these findings encouraging as hydrometric agencies can potentially leverage national-scale ALS and ADCP instrumentation to reduce the cost and effort required for maintaining and establish rating curves at gauging stations.

  18. Errors in acoustic doppler profiler velocity measurements caused by flow disturbance

    USGS Publications Warehouse

    Mueller, D.S.; Abad, J.D.; Garcia, C.M.; Gartner, J.W.; Garcia, M.H.; Oberg, K.A.

    2007-01-01

    Acoustic Doppler current profilers (ADCPs) are commonly used to measure streamflow and water velocities in rivers and streams. This paper presents laboratory, field, and numerical model evidence of errors in ADCP measurements caused by flow disturbance. A state-of-the-art three-dimensional computational fluid dynamic model is validated with and used to complement field and laboratory observations of flow disturbance and its effect on measured velocities. Results show that near the instrument, flow velocities measured by the ADCP are neither the undisturbed stream velocity nor the velocity of the flow field around the ADCP. The velocities measured by the ADCP are biased low due to the downward flow near the upstream face of the ADCP and upward recovering flow in the path of downstream transducer, which violate the flow homogeneity assumption used to transform beam velocities into Cartesian velocity components. The magnitude of the bias is dependent on the deployment configuration, the diameter of the instrument, and the approach velocity, and was observed to range from more than 25% at 5cm from the transducers to less than 1% at about 50cm from the transducers for the scenarios simulated. ?? 2007 ASCE.

  19. Acoustic Doppler current profiler measurements in coastal and estuarine environments: examples from the Tay Estuary, Scotland

    NASA Astrophysics Data System (ADS)

    Wewetzer, Silke F. K.; Duck, Robert W.; Anderson, James M.

    1999-08-01

    Acoustic Doppler current profilers (ADCPs) provide a means to measure the components of water current velocities in three dimensions. Such instruments have been used widely by the oil industry in deep offshore waters but their application to nearshore coastal and estuarine environments has been principally confined to the USA. Using examples of ADCP datasets acquired from the macrotidal Tay Estuary, eastern Scotland, the principles of field deployment, data acquisition and forms of output are critically summarised. It is shown, for the first time in the Tay Estuary, that vertical current velocities are significant and are particularly so in downwelling zones associated with the development and passage of axially convergent tidal fronts. The improved understanding of three-dimensional water and suspended sediment dynamics in coastal and estuarine waters is crucial to, inter alia, the sustainable management of effluent discharges and, in more general terms, it is predicted on the basis of the Tay case study, that ADCP measurements afford significant opportunities to refine understanding of geomorphological processes in a variety of aquatic environments worldwide.

  20. A General-applications Direct Global Matrix Algorithm for Rapid Seismo-acoustic Wavefield Computations

    NASA Technical Reports Server (NTRS)

    Schmidt, H.; Tango, G. J.; Werby, M. F.

    1985-01-01

    A new matrix method for rapid wave propagation modeling in generalized stratified media, which has recently been applied to numerical simulations in diverse areas of underwater acoustics, solid earth seismology, and nondestructive ultrasonic scattering is explained and illustrated. A portion of recent efforts jointly undertaken at NATOSACLANT and NORDA Numerical Modeling groups in developing, implementing, and testing a new fast general-applications wave propagation algorithm, SAFARI, formulated at SACLANT is summarized. The present general-applications SAFARI program uses a Direct Global Matrix Approach to multilayer Green's function calculation. A rapid and unconditionally stable solution is readily obtained via simple Gaussian ellimination on the resulting sparsely banded block system, precisely analogous to that arising in the Finite Element Method. The resulting gains in accuracy and computational speed allow consideration of much larger multilayered air/ocean/Earth/engineering material media models, for many more source-receiver configurations than previously possible. The validity and versatility of the SAFARI-DGM method is demonstrated by reviewing three practical examples of engineering interest, drawn from ocean acoustics, engineering seismology and ultrasonic scattering.

  1. Acoustical inverse problems regularization: Direct definition of filter factors using Signal-to-Noise Ratio

    NASA Astrophysics Data System (ADS)

    Gauthier, P.-A.; Gérard, A.; Camier, C.; Berry, A.

    2014-02-01

    Acoustic imaging aims at localization and characterization of sound sources using microphone arrays. In this paper a new regularization method for acoustic imaging by inverse approach is proposed. The method first relies on the singular value decomposition of the plant matrix and on the projection of the measured data on the corresponding singular vectors. In place of regularization using classical methods such as truncated singular value decomposition and Tikhonov regularization, the proposed method involves the direct definition of the filter factors on the basis of a thresholding operation, defined from the estimated measurement noise. The thresholding operation is achieved using modified filter functions. The originality of the approach is to propose the definition of a filter factor which provides more damping to the singular components dominated by noise than that given by the Tikhonov filter. This has the advantage of potentially simplifying the selection of the best regularization amount in inverse problems. Theoretical results show that this method is comparatively more accurate than Tikhonov regularization and truncated singular value decomposition.

  2. Prediction of the noise of flow over a cylinder by direct computation and acoustic analogy

    NASA Astrophysics Data System (ADS)

    Mani, Ali; Wang, Meng; Moin, Parviz

    2007-11-01

    The sound field of flow over a circular cylinder at ReD=3900 and Ma=0.4 is evaluated using Large-Eddy Simulation (LES). The acoustic results computed directly from LES are compared with those obtained using an integral solution of the Ffowcs Williams-Hawkings (FW-H) equation in conjunction with the LES source field data. The modified FW-H solution is derived using a free-space Green function which accounts for the uniform mean flow and spanwise periodicity in the flow simulation. In the implementation of the FW-H solution, the cylinder surface and three porous surfaces with different distances from the cylinder are used as integration surfaces. The effect of turbulent flow structures crossing the integration boundary on the generation of artificial noise is studied. The quadrupole terms in the FW-H equation are found to be important in canceling artificial noise regardless of their physical significance. Alternative formulations of acoustic analogy that can better handle the boundary terms will be discussed.

  3. Remote temperature profiling in the troposphere and stratosphere by the radio-acoustic sounding technique

    NASA Technical Reports Server (NTRS)

    Matuura, N.; Masuda, Y.; Inuki, H.

    1986-01-01

    Radar application of the radio-acoustic sounding technique uses the Doppler frequency shift of radar echoes returning from the atmospheric wave structure, in association with a traveling acoustic pulse transmitted from the ground, to determine the speed of sound, and hence the atmospheric temperature, as a function of altitude. Temperature measurement in the troposphere and stratosphere were determined using the radio-acoustic sounding technique with the Radio-Acoustic Sounding System (RASS). Successful experiments were performed in March 1985, and in August 1985.

  4. Tropospheric Wind Profile Measurements with a Direct Detection Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Li, Steven X.; Korb, C. Laurence; Chen, Huailin; Mathur, Savyasachee

    1998-01-01

    Research has established the importance of global tropospheric wind measurements for large scale improvements in numerical weather prediction. In addition, global wind measurements provide data that are fundamental to the understanding and prediction of global climate change. These tasks are closely linked with the goals of the NASA Earth Science Enterprise and Global Climate Change programs. NASA Goddard has been actively involved in the development of direct detection Doppler lidar methods and technologies to meet the wind observing needs of the atmospheric science community. In this paper we describe a recently developed prototype wind lidar system using a direct detection Doppler technique for measuring wind profiles from the surface through the troposphere. This system uses a pulsed ND:YAG laser operating at 1064 nm as the transmitter. The laser pulse is directed to the atmosphere using a 40 cm diameter scan mirror. The portion of the laser energy backscattered from aerosols and molecules is collected by a 40 cm diameter telescope and coupled via fiber optics into the Doppler receiver. Single photon counting APD's are used to detect the atmospheric backscattered signal. The principle element of the receiver is a dual bandpass tunable Fabry Perot etalon which analyzes the Doppler shift of the incoming laser signal using the double edge technique. The double edge technique uses two high resolution optical filters having bandpasses offset relative to one another such that the 'edge' of the first filter's transmission function crosses that of the second at the half power point. The outgoing laser frequency is located approximately at the crossover point. Due to the opposite going slopes of the edges, a Doppler shift in the atmospheric backscattered laser frequency produces a positive change in signal for one filter and a negative change in the second filter. Taking the ratio of the two edge channel signals yields a result which is directly proportional to the

  5. Tropospheric Wind Profile Measurements with a Direct Detection Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Li, Steven X.; Korb, C. Laurence; Chen, Huailin; Mathur, Savyasachee

    1998-01-01

    Research has established the importance of global tropospheric wind measurements for large scale improvements in numerical weather prediction. In addition, global wind measurements provide data that are fundamental to the understanding and prediction of global climate change. These tasks are closely linked with the goals of the NASA Earth Science Enterprise and Global Climate Change programs. NASA Goddard has been actively involved in the development of direct detection Doppler lidar methods and technologies to meet the wind observing needs of the atmospheric science community. In this paper we describe a recently developed prototype wind lidar system using a direct detection Doppler technique for measuring wind profiles from the surface through the troposphere. This system uses a pulsed ND:YAG laser operating at 1064 nm as the transmitter. The laser pulse is directed to the atmosphere using a 40 cm diameter scan mirror. The portion of the laser energy backscattered from aerosols and molecules is collected by a 40 cm diameter telescope and coupled via fiber optics into the Doppler receiver. Single photon counting APD's are used to detect the atmospheric backscattered signal. The principle element of the receiver is a dual bandpass tunable Fabry Perot etalon which analyzes the Doppler shift of the incoming laser signal using the double edge technique. The double edge technique uses two high resolution optical filters having bandpasses offset relative to one another such that the 'edge' of the first filter's transmission function crosses that of the second at the half power point. The outgoing laser frequency is located approximately at the crossover point. Due to the opposite going slopes of the edges, a Doppler shift in the atmospheric backscattered laser frequency produces a positive change in signal for one filter and a negative change in the second filter. Taking the ratio of the two edge channel signals yields a result which is directly proportional to the

  6. Direct opto-acoustic in vitro measurement of the spatial distribution of laser radiation in biological media

    SciTech Connect

    Pelivanov, Ivan M; Belov, Sergej A; Solomatin, Vladimir S; Khokhlova, Tanya D; Karabutov, Aleksander A

    2006-12-31

    The problem of opto-acoustic (AO) diagnostics of light scattering and absorption in biological media is considered. The objects under study were milk, bovine and porcine liver, and bovine muscle tissue. The forward and backward schemes for recording acoustic signals were used in experiments. The spatial distribution of the light intensity was measured for each biological medium from the temporal profile of the excited OA pulse and the absorption coefficient and reduced scattering coefficient were determined. Opto-acoustic signals were excited by a 1064-nm pulsed Nd:YAG laser and a tunable Ti:sapphire laser at 779 nm. It is shown that the proposed method can be used for obtaining a priori information on a biological medium in problems of optical and AO tomography. (special issue devoted to multiple radiation scattering in random media)

  7. Design and development of a synthetic acoustic antenna for highly directional sound measurements

    NASA Astrophysics Data System (ADS)

    Boone, Rinus

    1987-12-01

    A SYNThetic ACoustic ANtenna (SYNTACAN) for highly directional sound measurements with an average resolving power of 1.5 deg in the frequency range from 89 to 1413 Hz (4 octave bands) with resolution of 1/12 octave, was developed for measurement of sound emissions from individual sources on industrial areas. The applicability of SYNTACAN is illustrated with a large number of test measurements concerning resolution, focussing, correlations, screening, and coherence loss. Measurements of sound from large factories, sound radiation from rotor blades of wind turbines, and the estimation of the source height of passing vehicles are described. Similarity between the imaging technique of SYNTACAN and techniques in optical and radioastronomy, sonar, radar, and seismology is discussed. The influence of the finite length of the antenna and the disturbance of the wave propagation by turbulence in the medium, causing finite beam patterns and thus unsharp source images is considered.

  8. A Preliminary Evaluation of Near-Transducer Velocities Collected with Low-Blank Acoustic Doppler Current Profiler

    USGS Publications Warehouse

    Gartner, J.W.; Ganju, N.K.; ,

    2002-01-01

    Many streams and rivers for which the US Geological Survey must provide discharge measurements are too shallow to apply existing acoustic Doppler current profiler techniques for flow measurements of satisfactory quality. Because the same transducer is used for both transmitting and receiving acoustic signals in most Doppler current profilers, some small time delay is required for acoustic "ringing" to be damped out of transducers before meaningful measurements can be made. The result of that time delay is that velocity measurements cannot be made close to the transducer thus limiting the usefulness of these instruments in shallow regions. Manufacturers and users are constantly striving for improvements to acoustic instruments which would permit useful discharge measurements in shallow rivers and streams that are still often measured with techniques and instruments more than a century old. One promising area of advance appeared to be reduction of time delay (blank) required between transmitting and receiving signals during acoustic velocity measurements. Development of a low- or zero-blank transducer by RD Instruments3 held promise that velocity measurements could be made much closer to the transducer and thus in much shallower water. Initial experience indicates that this is not the case; limitation of measurement quality appears to be related to the physical presence of the transducer itself within the flow field. The limitation may be the result of changes to water flow pattern close to the transducer rather than transducer ringing characteristics as a function of blanking distance. Results of field experiments are discussed that support this conclusion and some minimum measurement distances from transducer are suggested based on water current speed and ADCP sample modes.

  9. Laser assisted direct write process with novel beam profiles

    NASA Astrophysics Data System (ADS)

    Shang, Shuo; Wellburn, Dan; Fearon, Eamonn; Yan, Shilian; Edwardson, Stuart; Dearden, G.; Watkins, K. G.

    2013-05-01

    The Laser Assisted Direct Write (LADW) method can be used to generate electrical circuitry on a substrate by depositing metallic ink and curing the ink thermally with a laser. Compared to conventional oven curing, laser curing can be used in-situ, over complicated 3D contours, and selectively cure over heat sensitive substrates. The intensity distribution of the laser beam used has significant influence on many surface heating processes. A conventional Gaussian beam would lead to uneven heating across the beam path. To overcome this issue, Wellburn has designed a novel beam shaping device, which allows one to convert a Gaussian beam profile into an annular ring with a variable level of central plateau fill [1]. Shang et al. have developed and verified a predictive Finite Element Method (FEM) model to simulate the laser curing process for a generic combination of processing parameters. Laser modes can be flexibly varied within this model. Hence it can be used to predict the performance of curing with differently intensity distributions. This study investigates the curing process under different intensity profiles obtained with the beam shaping device. Electrical resistivity and scratch resistance of cured samples are tested as measures of the curing quality achieved. Results obtained are then compared with the FEM model predictions, and indicate the best intensity distribution for this particular application.

  10. Directionality and maneuvering effects on a surface ship underwater acoustic signature.

    PubMed

    Trevorrow, Mark V; Vasiliev, Boris; Vagle, Svein

    2008-08-01

    This work examines underwater source spectra of a small (560 tons, 40 m length), single-screw oceanographic vessel, focusing on directionality and effects of maneuvers. The measurements utilized a set of four, self-contained buoys with GPS positioning, each recording two calibrated hydrophones with effective acoustic bandwidth from 150 Hz to 5 kHz. In straight, constant-speed runs at speeds up to 6.2 m s(-1), the ship source spectra showed spectral levels in reasonable agreement with reference spectra. The broadband source level was observed to increase as approximately speed to the fourth power over the range of 2.6-6.1 m s(-1), partially biased at low speeds by nonpropulsion machinery signals. Source directionality patterns were extracted from variations in source spectra while the ship transited past the buoy field. The observed spectral source levels exhibited a broadside maximum, with bow and stern aspect reduced by approximately 12-9 dB, respectively, independent of frequency. An empirical model is proposed assuming that spectral source levels exhibit simultaneous variations in aspect angle, speed, and turn rate. After correction for source directionality and speed during turning maneuvers, an excess of up to 18 dB in one-third octave source levels was observed.

  11. Modeling of an omni-directional electromagnetic acoustic transducer driven by the Lorentz force mechanism

    NASA Astrophysics Data System (ADS)

    Wang, Shen; Huang, Songling; Zhang, Yu; Zhao, Wei

    2016-12-01

    The electromagnetic acoustic transducers (EMATs) are gaining much attention in recent years due to their non-contact operation in ultrasonic wave generation and reception in NDT field. Quite often the transduction efficiency of EMATs is low, so efforts are always necessary to gain a better understanding of their complex and multi-physics transduction mechanism. In this work, we focused on modeling of an omni-directional Lorentz force-based EMAT operating on an aluminum disk and containing a rounded meander coil to generate a pure Lamb wave mode. We introduced an approach to solve the underlying eddy current equations in cylindrical coordinates directly, and applied this approach to a multi-conductor electromagnetic model to investigate the skin and proximity effects. These effects existed both for the complete and incomplete equations. Then we built the omni-directional EMAT model composed of three sub-models and two geometries. The two-geometry structure made it possible to reduce the total number of elements. Time varying spatial distribution of the Lorentz force vector was plotted. Propagation velocity of the simulated wave packet was compared with the group velocity of desired S0 mode Lamb waves. Interaction of the waves with a slot defect with a depth of 50% thickness was studied. The response to high current excitation and dynamic magnetic field was also investigated.

  12. Validation of streamflow measurements made with M9 and RiverRay acoustic Doppler current profilers

    USGS Publications Warehouse

    Boldt, Justin A.; Oberg, Kevin A.

    2015-01-01

    The U.S. Geological Survey (USGS) Office of Surface Water (OSW) previously validated the use of Teledyne RD Instruments (TRDI) Rio Grande (in 2007), StreamPro (in 2006), and Broadband (in 1996) acoustic Doppler current profilers (ADCPs) for streamflow (discharge) measurements made by the USGS. Two new ADCPs, the SonTek M9 and the TRDI RiverRay, were first used in the USGS Water Mission Area programs in 2009. Since 2009, the OSW and USGS Water Science Centers (WSCs) have been conducting field measurements as part of their stream-gaging program using these ADCPs. The purpose of this paper is to document the results of USGS OSW analyses for validation of M9 and RiverRay ADCP streamflow measurements. The OSW required each participating WSC to make comparison measurements over the range of operating conditions in which the instruments were used until sufficient measurements were available. The performance of these ADCPs was evaluated for validation and to identify any present and potential problems. Statistical analyses of streamflow measurements indicate that measurements made with the SonTek M9 ADCP using firmware 2.00–3.00 or the TRDI RiverRay ADCP using firmware 44.12–44.15 are unbiased, and therefore, can continue to be used to make streamflow measurements in the USGS stream-gaging program. However, for the M9 ADCP, there are some important issues to be considered in making future measurements. Possible future work may include additional validation of streamflow measurements made with these instruments from other locations in the United States and measurement validation using updated firmware and software.

  13. River habitat quality from river velocities measured using acoustic Doppler current profiler.

    PubMed

    Shields, F Douglas; Rigby, J R

    2005-10-01

    Prior research has demonstrated the utility of metrics based on spatial velocity gradients to characterize and describe stream habitat, with higher gradients generally indicative of higher levels of physical heterogeneity and thus habitat quality. However, detailed velocity data needed to compute these metrics are difficult to obtain. Acoustic Doppler current profilers (ADCP) may be used to rapidly collect detailed representations of river velocity fields. Herein we demonstrate use of ADCP to obtain ecologically relevant data and compute associated metrics. Data were collected from four reaches of the Little Tallahatchie River in northern Mississippi. Sampled reaches were selected to observe velocity regimes associated with three distinctly different conditions: downstream from a major flow obstruction (a low weir), downstream from the apices of each of two bends, and within an extremely long, straight reach created by channelization. Three-dimensional velocity data sets from each site were used to compute metrics of habitat quality proposed by others. A habitat metric based on the presence of rotational flow in the vertical plane proved to be the best discriminator among conditions within the sampled reaches. Two of four habitat quality metrics computed from these measured velocities were greatest for the sharpest meander bend. ADCP hold great potential for study of riverine physical aquatic habitats, particularly at the reach scale. Additional work is needed to develop generally applicable field protocols and data reduction tools. Specifically, guidelines for ADCP settings and configuration appropriate for a range of riverine site conditions must be developed. Advances in instrumentation are needed to allow collection of information in closer proximity to the free surface and solid boundaries.

  14. Diffraction-free acoustic detection for optoacoustic depth profiling of tissue using an optically transparent polyvinylidene fluoride pressure transducer operated in backward and forward mode.

    PubMed

    Jaeger, Michael; Niederhauser, Joël J; Hejazi, Marjaneh; Frenz, Martin

    2005-01-01

    An optoacoustic detection method suitable for depth profiling of optical absorption of layered or continuously varying tissue structures is presented. Detection of thermoelastically induced pressure transients allows reconstruction of optical properties of the sample to a depth of several millimeters with a spatial resolution of 24 mum. Acoustic detection is performed using a specially designed piezoelectric transducer, which is transparent for optical radiation. Thus, ultrasonic signals can be recorded at the same position the tissue is illuminated. Because the optoacoustical sound source is placed in the pulsed-acoustic near field of the pressure sensor, signal distortions commonly associated with acoustical diffraction are eliminated. Therefore, the acoustic signals mimic exactly the depth profile of the absorbed energy. This is illustrated by imaging the absorption profile of a two-layered sample with different absorption coefficients, and of a dye distribution while diffusing into a gelatin phantom.

  15. Shelf circulation prior to and post a cold front event measured from vessel-based acoustic Doppler current profiler

    NASA Astrophysics Data System (ADS)

    Li, Chunyan; Chen, Changsheng

    2014-11-01

    Shelf circulation impacted by a shift in wind regime during the passage of an atmospheric cold front system is studied with a field survey over the mid-shelf of the South Atlantic Bight between Oct 4 and 9, 2004. Weak southerly winds preceded the cold front for a few days, followed by a rapid shift in wind direction and strengthening of northeasterly winds over a few more days. More than 93 h of acoustic Doppler current profiler (ADCP) data were obtained along an equilateral triangle of 105 km in perimeter, which was continuously occupied for 11 times. A harmonic analysis was applied to extract tidal and subtidal wind-driven flow components by collapsing the 93 hour data into one M2 tidal period. It was found that the cross-shelf flow was barely affected by the wind while the along-shelf flow responded with a spatially uniform and almost steadily increasing mean flow velocity, superimposed on an oscillatory tidal current. The wind induced along-shelf transport was estimated to be ~ 0.3 Sv over the inner and middle shelf. The net cross-shelf transport was negligible. Apparently, the northeasterly wind causes an along-shelf current which was subject to Coriolis force that sets up an increasing coastal sea level pressure gradient as the water kept piling up against the coast, which was confirmed by tide gauge data. The observations found that the flow field prior to the strong winds had more complicated structures including eddy-like features, while after the strong northeasterly winds, the flow became eddy free and uniform in space. A theoretical model solved by a Laplace Transform was used to examine the wind-driven flow mechanism and the results were compared with the observations of net along-shelf flow velocity.

  16. Joint inversion for transponder localization and sound-speed profile temporal variation in high-precision acoustic surveys.

    PubMed

    Li, Zhao; Dosso, Stan E; Sun, Dajun

    2016-07-01

    This letter develops a Bayesian inversion for localizing underwater acoustic transponders using a surface ship which compensates for sound-speed profile (SSP) temporal variation during the survey. The method is based on dividing observed acoustic travel-time data into time segments and including depth-independent SSP variations for each segment as additional unknown parameters to approximate the SSP temporal variation. SSP variations are estimated jointly with transponder locations, rather than calculated separately as in existing two-step inversions. Simulation and sea-trial results show this localization/SSP joint inversion performs better than two-step inversion in terms of localization accuracy, agreement with measured SSP variations, and computational efficiency.

  17. Design of a semi-implantable hearing device for direct acoustic cochlear stimulation.

    PubMed

    Bernhard, Hans; Stieger, Christof; Perriard, Yves

    2011-02-01

    A new hearing therapy based on direct acoustic cochlear stimulation was developed for the treatment of severe to profound mixed hearing loss. The device efficacy was validated in an initial clinical trial with four patients. This semi-implantable investigational device consists of an externally worn audio processor, a percutaneous connector, and an implantable microactuator. The actuator is placed in the mastoid bone, right behind the external auditory canal. It generates vibrations that are directly coupled to the inner ear fluids and that, therefore, bypass the external and the middle ear. The system is able to provide an equivalent sound pressure level of 125 dB over the frequency range between 125 and 8000 Hz. The hermetically sealed actuator is designed to provide maximal output power by keeping its dimensions small enough to enable implantation. A network model is used to simulate the dynamic characteristics of the actuator to adjust its transfer function to the characteristics of the middle ear. The geometry of the different actuator components is optimized using finite-element modeling.

  18. Comparison of index velocity measurements made with a horizontal acoustic Doppler current profiler

    USGS Publications Warehouse

    Jackson, P. Ryan; Johnson, Kevin K.; Duncker, James J.

    2012-01-01

    The State of Illinois' annual withdrawal from Lake Michigan is limited by a U.S. Supreme Court decree, and the U.S. Geological Survey (USGS) is responsible for monitoring flows in the Chicago Sanitary and Ship Canal (CSSC) near Lemont, Illinois as a part of the Lake Michigan Diversion Accounting overseen by the U.S. Army Corps of Engineers, Chicago District. Every 5 years, a technical review committee consisting of practicing engineers and academics is convened to review the U.S. Geological Survey's streamgage practices in the CSSC near Lemont, Illinois. The sixth technical review committee raised a number of questions concerning the flows and streamgage practices in the CSSC near Lemont and this report provides answers to many of those questions. In addition, it is the purpose of this report to examine the index velocity meters in use at Lemont and determine whether the acoustic velocity meter (AVM), which is now the primary index velocity meter, can be replaced by the horizontal acoustic Doppler current profiler (H-ADCP), which is currently the backup meter. Application of the AVM and H-ADCP to index velocity measurements in the CSSC near Lemont, Illinois, has produced good ratings to date. The site is well suited to index velocity measurements in spite of the large range of velocities and highly unsteady flows at the site. Flow variability arises from a range of sources: operation of the waterway through control structures, lockage-generated disturbances, commercial and recreational traffic, industrial withdrawals and discharges, natural inflows, seiches, and storm events. The influences of these factors on the index velocity measurements at Lemont is examined in detail in this report. Results of detailed data comparisons and flow analyses show that use of bank-mounted instrumentation such as the AVM and H-ADCP appears to be the best option for index velocity measurement in the CSSC near Lemont. Comparison of the rating curves for the AVM and H-ADCP demonstrates

  19. Recent fault movement in Lake McDonald, Montana: Evidence from acoustic sub-bottom profiling

    NASA Astrophysics Data System (ADS)

    Dunbar, J. A.; Cronin, V. S.; Allen, P. M.; White, J. D.

    2011-12-01

    Lake McDonald is the largest of the 12 large lakes in Glacier National Park, Montana, formed in previously glaciated valleys and dammed by outwash and moraine deposits at their outlets. Lake McDonald is 15 km long, 1.6 km wide and trends northeast. The location of the lake was on the eastern edge of the Cordilleran Ice Sheet during the late Wisconsin Glaciation. Published maps indicate the lake basin is crossed by the northwest-striking Flathead and Nyack normal faults and two unnamed faults (Whipple, 1992, USGS Map I-1508-F). Recent seismicity in northwest Montana consists mostly of magnitude 3 to 4 earthquakes, one of which occurred between the Flathead and Nyack faults, northwest of the lake. Using 1 kHz Uniboom profiling of Lake McDonald, Mullins and others (1991, Arctic Alpine Res 23(3), 311-319) found 150 m of simply-stratified, undisturbed sediment fill within a V-shaped bedrock basin with steeply sloping sides. No evidence was found to suggest that the faults within the lake have been recently active. In this study, we collected 55 km of 24 kHz sub-bottom profiling data to more closely examine the upper 10 m of the sediment fill for evidence of recent fault motion. The upper 10 m of the fill consists of sub-meter thick, alternating layers of highly reflective and nearly acoustically transparent deposits, along with numerous chaotic mass-wasting deposits emanating from the adjacent sides of the basin. One of these mass-wasting deposits is 1.3 km wide, 5 m thick, and lies unburied on the modern lake floor. The trace of Flathead Fault, where it crosses the northeastern end of the lake, is marked by a precipitous, 125 m high, down-to-the-southwest escarpment. The base of the escarpment consists of a series of basinward-stepping terraces, the southwestern-most of which is onlapped by recent sediment. The onlapping sediments show no clear evidence of faulting next to the escarpment, but motion between the various terraces cannot be ruled out. The trace of Nyack

  20. Acoustic Noise Alters Selective Attention Processes as Indicated by Direct Current (DC) Brain Potential Changes

    PubMed Central

    Trimmel, Karin; Schätzer, Julia; Trimmel, Michael

    2014-01-01

    Acoustic environmental noise, even of low to moderate intensity, is known to adversely affect information processing in animals and humans via attention mechanisms. In particular, facilitation and inhibition of information processing are basic functions of selective attention. Such mechanisms can be investigated by analyzing brain potentials under conditions of externally directed attention (intake of environmental information) versus internally directed attention (rejection of environmental stimuli and focusing on memory/planning processes). This study investigated brain direct current (DC) potential shifts—which are discussed to represent different states of cortical activation—of tasks that require intake and rejection of environmental information under noise. It was hypothesized that without background noise rejection tasks would show more positive DC potential changes compared to intake tasks and that under noise both kinds of tasks would show positive DC shifts as an expression of cortical inhibition caused by noise. DC potential shifts during intake and rejection tasks were analyzed at 16 standard locations in 45 persons during irrelevant speech or white noise vs. control condition. Without noise, rejection tasks were associated with more positive DC potential changes compared to intake tasks. During background noise, however, this difference disappeared and both kinds of tasks led to positive DC shifts. Results suggest—besides some limitations—that noise modulates selective attention mechanisms by switching to an environmental information processing and noise rejection mode, which could represent a suggested “attention shift”. Implications for fMRI studies as well as for public health in learning and performance environments including susceptible persons are discussed. PMID:25264675

  1. Acoustic noise alters selective attention processes as indicated by direct current (DC) brain potential changes.

    PubMed

    Trimmel, Karin; Schätzer, Julia; Trimmel, Michael

    2014-09-26

    Acoustic environmental noise, even of low to moderate intensity, is known to adversely affect information processing in animals and humans via attention mechanisms. In particular, facilitation and inhibition of information processing are basic functions of selective attention. Such mechanisms can be investigated by analyzing brain potentials under conditions of externally directed attention (intake of environmental information) versus internally directed attention (rejection of environmental stimuli and focusing on memory/planning processes). This study investigated brain direct current (DC) potential shifts-which are discussed to represent different states of cortical activation-of tasks that require intake and rejection of environmental information under noise. It was hypothesized that without background noise rejection tasks would show more positive DC potential changes compared to intake tasks and that under noise both kinds of tasks would show positive DC shifts as an expression of cortical inhibition caused by noise. DC potential shifts during intake and rejection tasks were analyzed at 16 standard locations in 45 persons during irrelevant speech or white noise vs. control condition. Without noise, rejection tasks were associated with more positive DC potential changes compared to intake tasks. During background noise, however, this difference disappeared and both kinds of tasks led to positive DC shifts. Results suggest-besides some limitations-that noise modulates selective attention mechanisms by switching to an environmental information processing and noise rejection mode, which could represent a suggested "attention shift". Implications for fMRI studies as well as for public health in learning and performance environments including susceptible persons are discussed.

  2. Studies of the acoustic transmission characteristics of coaxial nozzles with inverted velocity profiles, volume 1. [jet engine noise radiation through coannular exhaust nozzles

    NASA Technical Reports Server (NTRS)

    Dean, P. D.; Salikuddin, M.; Ahuja, K. K.; Plumblee, H. E.; Mungur, P.

    1979-01-01

    The efficiency of internal noise radiation through coannular exhaust nozzle with an inverted velocity profile was studied. A preliminary investigation was first undertaken to: (1) define the test parameters which influence the internal noise radiation; (2) develop a test methodology which could realistically be used to examine the effects of the test parameters; (3) and to validate this methodology. The result was the choice of an acoustic impulse as the internal noise source in the in the jet nozzles. Noise transmission characteristics of a nozzle system were then investigated. In particular, the effects of fan nozzle convergence angle, core extention length to annulus height ratio, and flow Mach number and temperatures were studied. The results are presented as normalized directivity plots.

  3. FROM THE CURRENT LITERATURE: Laser excitation of surface acoustic waves: a new direction in opto-acoustic spectroscopy of a solid

    NASA Astrophysics Data System (ADS)

    Karabutov, Aleksander A.

    1985-11-01

    Studies in thermo-optic excitation of surface acoustic waves are reviewed. The excitation of periodic and pulse signals is discussed, using nonmoving and moving beams. Most attention is paid to application of this effect for purposes of opto-acoustic spectroscopy of a solid. The possibilities and promises of using opto-acoustic spectroscopy (OAS) employing surface acoustic waves (SAW) are analyzed

  4. Method of establishing a stratigraphic model of the subsurface from an acoustic impedance profile and a seismic section

    SciTech Connect

    Carron, D.

    1990-10-16

    This patent describes a method of establishing a stratigraphic model of the subsurface from an acoustic impedance profile A{sub {ital 0}} = {minus} {l brace}a{sub {ital 0}}(n),n = 1,N{r brace} corresponding to a series of reflection coefficients R{sub {ital 0}} = {l brace}r{sub {ital 0}}(n),n = 1,N{r brace}, where n is an index relating to the depth sampled in time t, and from a seismic section comprising a plurality of seismic traces T{sub {ital i}}(t),i = 0, I recorded in response to the emission of a seismic wave of signature W(t). It comprises: successively determining each series of coefficients R{sub {ital i}} = {minus} {l brace}r{sub {ital i}}(n), N = 1,N{r brace} by minimizing a cross-entropy function H(R{sub {ital i}}/R{sub {ital i}}) between firstly a series R{sub {ital i}} obtained from the series R{sub 1{minus}1} and a set of one or more seismic traces {l brace}T{sub {ital i{minus}j}},T{sub {ital i + j}}{r brace}, and secondly the looked-for series R{sub {ital i}}, the minimization being performed under pre-established constraints; determining the acoustic impedance profiles A{sub {ital i}} = {l brace}a{sub {ital i}}(n){r brace} corresponding to the series R{sub {ital i}}, and establishing the stratigraphic model of the subsurface from the acoustic impedance profiles A{sub {ital i}}.

  5. Direct-laser metal writing of surface acoustic wave transducers for integrated-optic spatial light modulators in lithium niobate

    NASA Astrophysics Data System (ADS)

    Datta, Bianca C.; Savidis, Nickolaos; Moebius, Michael; Jolly, Sundeep; Mazur, Eric; Bove, V. Michael

    2017-02-01

    Recently, the fabrication of high-resolution silver nanostructures using a femtosecond laser-based direct write process in a gelatin matrix was reported. The application of direct metal writing towards feature development has also been explored with direct metal fusion, in which metal is fused onto the surface of the substrate via a femtosecond laser process. In this paper, we present a comparative study of gelatin matrix and metal fusion approaches for directly laser-written fabrication of surface acoustic wave transducers on a lithium niobate substrate for application in integrated optic spatial light modulators.

  6. Delay-and-sum beamforming for direction of arrival estimation applied to gunshot acoustics

    NASA Astrophysics Data System (ADS)

    Ramos, António L. L.; Holm, Sverre; Gudvangen, Sigmund; Otterlei, Ragnvald

    2011-06-01

    Sniper positioning systems described in the literature use a two-step algorithm to estimate the sniper's location. First, the shockwave and the muzzle blast acoustic signatures must be detected and recognized, followed by an estimation of their respective direction-of-arrival (DOA). Second, the actual sniper's position is calculated based on the estimated DOA via an iterative algorithm that varies from system to system. The overall performance of such a system, however, is highly compromised when the first step is not carried out successfully. Currently available systems rely on a simple calculation of differences of time-of-arrival to estimate angles-of-arrival. This approach, however, lacks robustness by not taking full advantage of the array of sensors. This paper shows how the delay-and-sum beamforming technique can be applied to estimate the DOA for both the shockwave and the muzzle blast. The method has the twofold advantage of 1) adding an array gain of 10 logM, i.e., an increased SNR of 6 dB for a 4-microphone array, which is equivalent to doubling the detection range assuming free-field propagation; and 2) offering improved robustness in handling single- and multi-shots events as well as reflections by taking advantage of the spatial filtering capability.

  7. Acoustic parameters of infant-directed singing in mothers of infants with down syndrome.

    PubMed

    de l'Etoile, Shannon; Behura, Samarth; Zopluoglu, Cengiz

    2017-09-18

    This study compared the acoustic parameters and degree of perceived warmth in two types of infant-directed (ID) songs - the lullaby and the playsong - between mothers of infants with Down syndrome (DS) and mothers of typically-developing (TD) infants. Participants included mothers of 15 DS infants and 15 TD infants between 3 and 9 months of age. Each mother's singing voice was digitally recorded while singing to her infant and subjected to feature extraction and data mining. Mothers of DS infants and TD infants sang both lullabies and playsongs with similar frequency. In comparison with mothers of TD infants, mothers of DS infants used a higher maximum pitch and more key changes during playsong. Mothers of DS infants also took more time to establish a rhythmic structure in their singing. These differences suggest mothers are sensitive to the attentional and arousal needs of their DS infants. Mothers of TD infants sang with a higher degree of perceived warmth which does not agree with previous observations of "forceful warmth" in mothers of DS infants. In comparison with lullaby, all mothers sang playsong with higher overall pitch and slower tempo. Playsongs were also distinguished by higher levels of spectral centroid properties related to emotional expressivity, as well as higher degrees of perceived warmth. These similarities help to define specific song types, and suggest that all mothers sing in an expressive manner that can modulate infant arousal, including mothers of DS infants. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Chelyabinsk meteoroid entry: analysis of acoustic signals in the area of direct sound propagation

    NASA Astrophysics Data System (ADS)

    Podobnaya, Elena; Popova, Olga; Glazachev, Dmitry; Rybnov, Yurij; Shuvalov, Valery; Jenniskens, Peter; Kharlamov, Vladimir

    E.Podobnaya, Yu.Rybnov, O.Popova, V. Shuvalov, P. Jenniskens, V.Kharlamov, D.Glazachev The Chelyabinsk airburst of 15 February 2013, was exceptional because of the large kinetic energy of the impacting body and the airburst that was generated, creating significant damage and injuries in a populated area. The meteor and the effects of the airburst were extraordinarily well documented. Numerous video records provided an accurate record of the trajectory and orbit of the cosmic body as well as features of its interaction with the atmosphere (Borovicka et al., 2013; Popova et al. 2013). In this presentation, we discuss the information on shock wave arrival times. Arrival times of the shock wave were derived from the shaking of the camera, the movement of smoke or car exhaust, and the movement of cables in the field of view, as well as directly from the audio record. From the analysis of these shock wave arrival times, the altitudes of the energy deposition were derived (Popova et al. 2013). Borovicka et al (2013) suggested that subsequent acoustic arrivals corresponded to separate fragmentation events. The observed arrival times will be compared with model estimates taking into account the real wind and atmospheric conditions (i.e. sound velocity changes with altitude). Results of numerical simulations will be compared with recorded sound signals. References Borovicka J. et al., 2013, Nature 503, 235 Popova O. et al., 2013, Science, 342, 1096

  9. EGG and acoustic analyses of different voice samples: comparison between perceptual evaluation and voice activity and participation profile.

    PubMed

    Kankare, Elina; Liu, Dong; Laukkanen, Anne-Maria; Geneid, Ahmed

    2013-01-01

    This study investigated whether different electroglottographic (EGG) parameters may be used to estimate voice quality and loading related to it, and whether voice quality is related to self-estimation of voice problems and laryngeal status. The effect of sample type was also considered. EGG and acoustic signals of a sustained vowel [a:] (90 dB6 cm) and text reading during noise exposure were recorded from 93 female kindergarten teachers. Analyses were made from the sustained vowel and vowel [a:] from a stressed word. Contact quotient (CQ) was calculated. Maximum velocity of increase in contact area inferred from derivative (MDEGG) was examined. Fundamental frequency was calculated from the EGG signal. From the acoustic signal sound pressure level (SPL) was computed and pressedness in voice quality was evaluated perceptually. Self-evaluation was made with Voice Activity and Participation Profile (VAPP). Indirect laryngoscopy was also performed. Pressedness in voice correlated with EGG results only for the sustained vowel, and better with MDEGG than CQ values. VAPP and laryngeal evaluation did not correlate with the acoustic or EGG parameters or with perception. MDEGG is worth testing as an indicator of impact stress. Sustained vowel at a controlled SPL is more suitable for voice quality evaluation than a long stressed vowel from connected speech. © 2013 S. Karger AG, Basel.

  10. First clinical experiences with a direct acoustic cochlear stimulator in comparison to preoperative fitted conventional hearing aids.

    PubMed

    Busch, Susan; Kruck, Stefanie; Spickers, Dirk; Leuwer, Rudolf; Hoth, Sebastian; Praetorius, Mark; Plinkert, Peter K; Mojallal, Hamidreza; Schwab, Burkard; Maier, Hannes; Lenarz, Thomas

    2013-12-01

    Patients with moderate-to-severe mixed hearing losses (MHLs) are hard to provide sufficient benefit with currently available conventional hearing aids. Here, the long-term safety of a direct acoustic cochlear stimulator (DACS) and the effectiveness compared with conventional "high-performance" hearing aids were investigated. Prospective, within patient reference, nonrandomized, interventional multicenter clinical study performed at these 3 centers: Medical University Hannover, University of Heidelberg, and Helios Hospital Krefeld. Ten otosclerosis patients with severe-to-profound MHL were preoperatively fitted with state-of-the-art conventional hearing aids (HA). After 2 months of testing conventional HA, 9 of the patients decided to be implanted with a DACS. Air conduction (AC) and bone conduction (BC) aided and unaided thresholds, speech discrimination before and after implantation and at 3, 6, and 12 months after activation. The subjective benefit was assessed by the Abbreviated Profile of Hearing Aid Benefit (APHAB). Preoperative hearing thresholds were preserved over the 12 month observation time after activation. Average functional gain (0.5-4 kHz) achieved with conventional HA was 47 dB compared with 56 dB with the DACS. Speech-in-noise tests revealed a lower SNR for DACS (3.1 dB) than for the HA (6.6 dB) and patients were more satisfied with the DACS. The DACS significantly improved hearing, speech intelligibility, and satisfaction in patients with a severe-to-profound mixed hearing loss and can be considered a safe and useful alternative to conventional hearing aids.

  11. What affects facing direction in human facial profile drawing? A meta-analytic inquiry.

    PubMed

    Tosun, Sümeyra; Vaid, Jyotsna

    2014-01-01

    Two meta-analyses were conducted to examine two potential sources of spatial orientation biases in human profile drawings by brain-intact individuals. The first examined profile facing direction as function of hand used to draw. The second examined profile facing direction in relation to directional scanning biases related to reading/writing habits. Results of the first meta-analysis, based on 27 study samples with 4171 participants, showed that leftward facing of profiles (from the viewer's perspective) was significantly associated with using the right hand to draw. The reading/writing direction meta-analysis, based on 10 study samples with 1552 participants, suggested a modest relationship between leftward profile facing and primary use of a left-to-right reading/writing direction. These findings suggest that biomechanical and cultural factors jointly influence hand movement preferences and in turn the direction of facing of human profile drawings.

  12. Rapid profiling of enteric coated drug delivery spheres via broadband acoustic resonance dissolution spectroscopy (BARDS).

    PubMed

    Fitzpatrick, D; Evans-Hurson, R; Fu, Y; Burke, T; Krüse, J; Vos, B; McSweeney, S G; Casaubieilh, P; Keating, J J

    2014-03-07

    There is an increased trend towards the use of drug and enteric coated sugar spheres for controlled oral delivery of active pharmaceutical ingredients (API). This trend is driven by increased efficacy and ease of formulation of different dosage levels. However, difficulties exist in determining the thickness of drug and enteric coatings in a time efficient manner during manufacture, quality assurance and stability testing. The thickness of the coating determines the dosage of the API and the thickness of the enteric coating determines the release rate of the drug in the gastro-intestinal tract. Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) offers a rapid new approach to characterising the enteric coating thickness and the raw materials used in their manufacture. BARDS applications are based on reproducible changes in the compressibility of a solvent during dissolution which is monitored acoustically due to associated changes in the speed of sound in solution. It is demonstrated how core delivery sugar spheres have unique acoustic spectra attributable to the mean size distribution of the spheres. A steady state acoustic lag time is associated with the disintegration of the enteric coating, in basic solution. This lag time can be manipulated by varying the concentration of the base which affects the rate at which the coating dissolves. It is anticipated that the thickness/loading of the spheres can be estimated from the lag time.

  13. Ocean acoustic reverberation tomography.

    PubMed

    Dunn, Robert A

    2015-12-01

    Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

  14. QRev—Software for computation and quality assurance of acoustic doppler current profiler moving-boat streamflow measurements—User’s manual for version 2.8

    USGS Publications Warehouse

    Mueller, David S.

    2016-05-12

    The software program, QRev computes the discharge from moving-boat acoustic Doppler current profiler measurements using data collected with any of the Teledyne RD Instrument or SonTek bottom tracking acoustic Doppler current profilers. The computation of discharge is independent of the manufacturer of the acoustic Doppler current profiler because QRev applies consistent algorithms independent of the data source. In addition, QRev automates filtering and quality checking of the collected data and provides feedback to the user of potential quality issues with the measurement. Various statistics and characteristics of the measurement, in addition to a simple uncertainty assessment are provided to the user to assist them in properly rating the measurement. QRev saves an extensible markup language file that can be imported into databases or electronic field notes software. The user interacts with QRev through a tablet-friendly graphical user interface. This report is the manual for version 2.8 of QRev.

  15. Deep Water Acoustics

    DTIC Science & Technology

    2016-06-28

    intensity profile (see figure 4)—which is to be expected due to the infinite-frequency assumption inherent in a ray model. The high - intensity values at...perturbations and the characteristics of the ambient acoustic noise field . Scattering and diffraction resulting from internal waves and other ocean...processes limit the temporal and spatial coherence of the received signal, while the ambient noise field is in direct competition with the received

  16. Klamath River Water Quality and Acoustic Doppler Current Profiler Data from Link River Dam to Keno Dam, 2007

    USGS Publications Warehouse

    Sullivan, Annett B.; Deas, Michael L.; Asbill, Jessica; Kirshtein, Julie D.; Butler, Kenna D.; Stewart, Marc A.; Wellman, Roy W.; Vaughn, Jennifer

    2008-01-01

    In 2007, the U.S. Geological Survey, Watercourse Engineering, and the Bureau of Reclamation began a project to construct and calibrate a water quality and hydrodynamic model of the 21-mile reach of the Klamath River from Link River Dam to Keno Dam. To provide a basis for this work, data collection and experimental work were planned for 2007 and 2008. This report documents sampling and analytical methods and presents data from the first year of work. To determine water velocities and discharge, a series of cross-sectional acoustic Doppler current profiler (ADCP) measurements were made on the mainstem and four canals on May 30 and September 19, 2007. Water quality was sampled weekly at five mainstem sites and five tributaries from early April through early November, 2007. Constituents reported here include field parameters (water temperature, pH, dissolved oxygen concentration, specific conductance); total nitrogen and phosphorus; particulate carbon and nitrogen; filtered orthophosphate, nitrite, nitrite plus nitrate, ammonia, organic carbon, iron, silica, and alkalinity; specific UV absorbance at 254 nm; phytoplankton and zooplankton enumeration and species identification; and bacterial abundance and morphological subgroups. The ADCP measurements conducted in good weather conditions in May showed that four major canals accounted for most changes in discharge along the mainstem on that day. Direction of velocity at measured locations was fairly homogeneous across the channel, while velocities were generally lowest near the bottom, and highest near surface, ranging from 0.0 to 0.8 ft/s. Measurements in September, made in windy conditions, raised questions about the effect of wind on flow. Most nutrient and carbon concentrations were lowest in spring, increased and remained elevated in summer, and decreased in fall. Dissolved nitrite plus nitrate and nitrite had a different seasonal cycle and were below detection or at low concentration in summer. Many nutrient and

  17. Speech reception with different bilateral directional processing schemes: Influence of binaural hearing, audiometric asymmetry, and acoustic scenario.

    PubMed

    Neher, Tobias; Wagener, Kirsten C; Latzel, Matthias

    2017-09-01

    Hearing aid (HA) users can differ markedly in their benefit from directional processing (or beamforming) algorithms. The current study therefore investigated candidacy for different bilateral directional processing schemes. Groups of elderly listeners with symmetric (N = 20) or asymmetric (N = 19) hearing thresholds for frequencies below 2 kHz, a large spread in the binaural intelligibility level difference (BILD), and no difference in age, overall degree of hearing loss, or performance on a measure of selective attention took part. Aided speech reception was measured using virtual acoustics together with a simulation of a linked pair of completely occluding behind-the-ear HAs. Five processing schemes and three acoustic scenarios were used. The processing schemes differed in the tradeoff between signal-to-noise ratio (SNR) improvement and binaural cue preservation. The acoustic scenarios consisted of a frontal target talker presented against two speech maskers from ±60° azimuth or spatially diffuse cafeteria noise. For both groups, a significant interaction between BILD, processing scheme, and acoustic scenario was found. This interaction implied that, in situations with lateral speech maskers, HA users with BILDs larger than about 2 dB profited more from preserved low-frequency binaural cues than from greater SNR improvement, whereas for smaller BILDs the opposite was true. Audiometric asymmetry reduced the influence of binaural hearing. In spatially diffuse noise, the maximal SNR improvement was generally beneficial. N0Sπ detection performance at 500 Hz predicted the benefit from low-frequency binaural cues. Together, these findings provide a basis for adapting bilateral directional processing to individual and situational influences. Further research is needed to investigate their generalizability to more realistic HA conditions (e.g., with low-frequency vent-transmitted sound). Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Choice reaction times for human head rotations are shortened by startling acoustic stimuli, irrespective of stimulus direction.

    PubMed

    Oude Nijhuis, Lars B; Janssen, Loes; Bloem, Bastiaan R; van Dijk, J Gert; Gielen, Stan C; Borm, George F; Overeem, Sebastiaan

    2007-10-01

    Auditory startle reflexes can accelerate simple voluntary reaction times (StartReact effect). To investigate the role of startle reflexes on more complex motor behaviour we formulated two questions: (1) can auditory startle reflexes shorten choice reaction times?; (2) is the StartReact effect differentially modulated when startling auditory stimuli are delivered ipsilaterally or contralaterally to an imperative 'go' signal? We instructed 16 healthy subjects to rotate their head as rapidly as possible to the left or to right in response to a guiding visual imperative stimulus (IS), in both a simple and choice reaction protocol. Startling acoustic stimuli (113 dB) were delivered simultaneously with the IS (from either the same or opposite side) to induce the StartReact effect. We recorded kinematics of head rotations and electromyographic responses. The StartReact effect was present during choice reaction tasks (56 ms onset reduction; P < 0.001). The presentation side of the startling stimulus (left/right) did not influence the effect in choice reaction tasks. We observed a directional effect in simple reaction tasks, but this probably occurred due to a flooring effect of reaction times. Onsets of EMG responses in neck muscles were not influenced by the direction of the acoustic startling stimulus. Startling acoustic stimuli decrease reaction times not only in simple but also in choice reaction time tasks, suggesting that startle reflexes can accelerate adequate human motor responses. The absence of a clear directional sensitivity of reaction times to startling acoustic stimuli suggests that the acceleration is not highly specific, but seems to provide a global preparatory effect upon which further tailored action can be undertaken more quickly.

  19. Application of iterative hill climbing to the sound speed profile inversion in underwater acoustics

    NASA Astrophysics Data System (ADS)

    Zaikin, O.; Petrov, P.

    2017-02-01

    An application of the iterative hill climbing algorithm to the solution of inverse problems of underwater acoustics is discussed. Modal dispersion data extracted from a recording of a pulse acoustical signal is used as the input for the geoacoustic inversion procedure. The mismatch of the dispersion curves extracted from experimental data and computed from a given set of waveguide parameters is minimized over the parameters space. The solution of two test inversion problems is considered. It is shown that the iterative launches of the hill climbing algorithm allow to locate either the global minimum or a local minimum which is reasonably close to the former. In the latter case a reasonable estimate of the waveguide parameters is obtained.

  20. The effect of static force on round window stimulation with the direct acoustic cochlea stimulator.

    PubMed

    Maier, Hannes; Salcher, Rolf; Schwab, Burkard; Lenarz, Thomas

    2013-07-01

    The Direct Acoustic Cochlea Stimulator Partial Implant (DACS PI, Phonak Acoustic Implants SA, Switzerland) is intended to stimulate the cochlea by a conventional stapedotomy piston that is crimped onto the DACS PI artificial incus. An alternative approach to the round window (RW) is successfully done with other devices, having the advantage of being also independent of the existence of middle ear structure (e.g. ossicles). Here the possibility of stimulating the RW with the DACS actuator is investigated including the impact of static force on sound transmission to the cochlea. The maximum equivalent sound pressure output with RW stimulation was determined experimentally in fresh human temporal bones. Experiments were performed in analogy to the ASTM standard (F2504.24930-1) method for the output determination of implantable middle ear hearing devices (IMEHDs) in human cadaveric temporal bones (TBs). ASTM compliant temporal bones were stimulated with a prosthesis having a spherical tip (∅0.5 mm) attached to the actuator. The stimulation was performed perpendicular to the round window membrane (RWM) at varying position relative to the RW and the resulting static force on the RW membrane was determined. At each position the displacement output of the DACS PI actuator and the stapes footplate (SFP) vibration in response to actuator stimulation was measured with a Laser Doppler Velocimeter (LDV). By comparison of the achieved output at the stapes footplate in response to sound and transducer stimulation the equivalent sound pressure level at the tympanic membrane at 1Vrms input voltage was calculated assuming that the SFP displacement in both conditions is a measure of perceived loudness, as it is done in the ASTM standard. Ten TB preparations within the acceptance range of the ASTM standard were used for analysis. The actuator driven stapes footplate displacement amplitude as well as the resulting equivalent sound pressure level was highly dependent on the static

  1. Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires

    SciTech Connect

    Kargar, Fariborz; Debnath, Bishwajit; Kakko, Joona -Pekko; Säynätjoki, Antti; Lipsanen, Harri; Nika, Denis L.; Lake, Roger K.; Balandin, Alexander A.

    2016-11-10

    Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin-Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined acoustic phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are in excellent agreement with theory. The phonon confinement effects result in a decrease in the phonon group velocity along the nanowire axis and changes in the phonon density of states. Furthermore, the obtained results can lead to more efficient nanoscale control of acoustic phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices.

  2. Profiles of foreign direct investment in US energy, 1992

    SciTech Connect

    Not Available

    1994-05-16

    The report reviews the patterns of foreign ownership interest in US energy enterprises, exclusive of portfolio investment (<10% ownership of a US enterprise). It profiles the involvement of foreign-affiliated US companies in the following areas: domestic petroleum production (including natural gas), reserve holdings, refining and marketing activities, coal production, and uranium exploration and development.

  3. Micromachined silicon acoustic delay line with 3D-printed micro linkers and tapered input for improved structural stability and acoustic directivity

    NASA Astrophysics Data System (ADS)

    Cho, Y.; Kumar, A.; Xu, S.; Zou, J.

    2016-10-01

    Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. To achieve deeper imaging depth and wider field of view, a longer delay time and therefore delay length are required. However, as the length of the delay line increases, it becomes more vulnerable to structural instability due to reduced mechanical stiffness. In this paper, we report the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, the improvement of the acoustic acceptance angle of the silicon acoustic delay lines was also investigated to better suppress the reception of unwanted ultrasound signals outside of the imaging plane. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

  4. Methodological considerations of acoustic playbacks to test the behavioral significance of call directionality in male northern elephant seals (Mirounga angustirostris)

    NASA Astrophysics Data System (ADS)

    Holt, Marla M.; Insley, Stephen J.; Southall, Brandon L.; Schusterman, Ronald J.

    2005-09-01

    While attempting to gain access to receptive females, male northern elephant seals form dominance hierarchies through multiple dyadic interactions involving visual and acoustic signals. These signals are both highly stereotyped and directional. Previous behavioral observations suggested that males attend to the directional cues of these signals. We used in situ vocal playbacks to test whether males attend to directional cues of the acoustic components of a competitors calls (i.e., variation in call spectra and source levels). Here, we will focus on playback methodology. Playback calls were multiple exemplars of a marked dominant male from an isolated area, recorded with a directional microphone and DAT recorder and edited into a natural sequence that controlled call amplitude. Control calls were recordings of ambient rookery sounds with the male calls removed. Subjects were 20 marked males (10 adults and 10 subadults) all located at An~o Nuevo, CA. Playback presentations, calibrated for sound-pressure level, were broadcast at a distance of 7 m from each subject. Most responses were classified into the following categories: visual orientation, postural change, calling, movement toward or away from the loudspeaker, and re-directed aggression. We also investigated developmental, hierarchical, and ambient noise variables that were thought to influence male behavior.

  5. Tidal and residual currents measured by an acoustic doppler current profiler at the west end of Carquinez Strait, San Francisco Bay, California, March to November 1988

    USGS Publications Warehouse

    Burau, J.R.; Simpson, M.R.; Cheng, R.T.

    1993-01-01

    Water-velocity profiles were collected at the west end of Carquinez Strait, San Francisco Bay, California, from March to November 1988, using an acoustic Doppler current profiler (ADCP). These data are a series of 10-minute-averaged water velocities collected at 1-meter vertical intervals (bins) in the 16.8-meter water column, beginning 2.1 meters above the estuary bed. To examine the vertical structure of the horizontal water velocities, the data are separated into individual time-series by bin and then used for time-series plots, harmonic analysis, and for input to digital filters. Three-dimensional graphic renditions of the filtered data are also used in the analysis. Harmonic analysis of the time-series data from each bin indicates that the dominant (12.42 hour or M2) partial tidal currents reverse direction near the bottom, on average, 20 minutes sooner than M2 partial tidal currents near the surface. Residual (nontidal) currents derived from the filtered data indicate that currents near the bottom are pre- dominantly up-estuary during the neap tides and down-estuary during the more energetic spring tides.

  6. Ultrasonic condition monitoring of composite structures using a low-profile acoustic source and an embedded optical fiber sensor

    NASA Astrophysics Data System (ADS)

    Pierce, S. Gareth; Staszewski, Wieslaw J.; Gachagan, Anthony; James, I. R.; Philip, Wayne R.; Worden, Keith; Culshaw, Brian; McNab, Alistair; Tomlinson, Geoffrey R.; Hayward, Gordon

    1997-06-01

    The purpose of this paper is to provide a concise introduction to the developments and recent findings of a BRITE-EURAM program of work (BRE2.CT94-0990 , structurally integrated system for the comprehensive evaluation of composites). The aim of the program has been to develop an acoustic/ultrasonic based structural monitoring system for composite structures using material compatible sensors. Since plate-like structures have been investigated, it has been a requirement to utilize the propagation of ultrasonic Lamb waves through the sample materials. Preliminary investigations utilized conventional piezo-electric sources coupled to the sample via perspex wedges. The Lamb waves generated by these sources were monitored using either a fully embedded or surface mounted optical fiber sensors. The system was tested with a variety of different carbon and glass fiber reinforced panels, and the interaction of the lamb waves with different defects in these materials was monitored. Conventional signal processing allowed the location of defects such as impact damage sites, delaminations and holes. Subsequent investigations have endeavored to refine the system. This paper reports the development of advanced wavelet based signal processing techniques to enhance defect visibility, the optical connectorization of composite panels, and the development of flexible low profile acoustic sources for efficient Lamb wave generation.

  7. Discharge-measurement system using an acoustic Doppler current profiler with applications to large rivers and estuaries

    USGS Publications Warehouse

    Simpson, Michael R.; Oltmann, Richard N.

    1993-01-01

    Discharge measurement of large rivers and estuaries is difficult, time consuming, and sometimes dangerous. Frequently, discharge measurements cannot be made in tide-affected rivers and estuaries using conventional discharge-measurement techniques because of dynamic discharge conditions. The acoustic Doppler discharge-measurement system (ADDMS) was developed by the U.S. Geological Survey using a vessel-mounted acoustic Doppler current profiler coupled with specialized computer software to measure horizontal water velocity at 1-meter vertical intervals in the water column. The system computes discharge from water-and vessel-velocity data supplied by the ADDMS using vector-algebra algorithms included in the discharge-measurement software. With this system, a discharge measurement can be obtained by engaging the computer software and traversing a river or estuary from bank to bank; discharge in parts of the river or estuarine cross sections that cannot be measured because of ADDMS depth limitations are estimated by the system. Comparisons of ADDMS-measured discharges with ultrasonic-velocity-meter-measured discharges, along with error-analysis data, have confirmed that discharges provided by the ADDMS are at least as accurate as those produced using conventional methods. In addition, the advantage of a much shorter measurement time (2 minutes using the ADDMS compared with 1 hour or longer using conventional methods) has enabled use of the ADDMS for several applications where conventional discharge methods could not have been used with the required accuracy because of dynamic discharge conditions.

  8. Depression Diagnoses and Fundamental Frequency-Based Acoustic Cues in Maternal Infant-Directed Speech

    ERIC Educational Resources Information Center

    Porritt, Laura L.; Zinser, Michael C.; Bachorowski, Jo-Anne; Kaplan, Peter S.

    2014-01-01

    F[subscript 0]-based acoustic measures were extracted from a brief, sentence-final target word spoken during structured play interactions between mothers and their 3- to 14-month-old infants and were analyzed based on demographic variables and DSM-IV Axis-I clinical diagnoses and their common modifiers. F[subscript 0] range (?F[subscript 0]) was…

  9. Depression Diagnoses and Fundamental Frequency-Based Acoustic Cues in Maternal Infant-Directed Speech

    ERIC Educational Resources Information Center

    Porritt, Laura L.; Zinser, Michael C.; Bachorowski, Jo-Anne; Kaplan, Peter S.

    2014-01-01

    F[subscript 0]-based acoustic measures were extracted from a brief, sentence-final target word spoken during structured play interactions between mothers and their 3- to 14-month-old infants and were analyzed based on demographic variables and DSM-IV Axis-I clinical diagnoses and their common modifiers. F[subscript 0] range (?F[subscript 0]) was…

  10. Flight effects on the aero/acoustic characteristics of inverted profile coannular nozzles

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    The effect of simulated flight speed on the acoustic and aerodynamic characteristics of coannular nozzles is examined. The noise and aerodynamic performance of the coannular nozzle exhaust systems over a large range of operating flight conditions is presented. The jet noise levels of the coannular nozzles are discussed. The impact of fan to primary nozzle area ratio and the presence of an ejector on flight effects are investigated. The impact of flight speed on the individual components of the coannular jet noise was ascertained.

  11. Flow velocity profiling using acoustic time of flight flow metering based on wide band signals and adaptive beam-forming techniques

    NASA Astrophysics Data System (ADS)

    Murgan, I.; Candel, I.; Ioana, C.; Digulescu, A.; Bunea, F.; Ciocan, G. D.; Anghel, A.; Vasile, G.

    2016-11-01

    In this paper, we present a novel approach to non-intrusive flow velocity profiling technique using multi-element sensor array and wide-band signal's processing methods. Conventional techniques for the measurements of the flow velocity profiles are usually based on intrusive instruments (current meters, acoustic Doppler profilers, Pitot tubes, etc.) that take punctual velocity readings. Although very efficient, these choices are limited in terms of practical cases of applications especially when non-intrusive measurements techniques are required and/or a spatial accuracy of the velocity profiling is required This is due to factors related to hydraulic machinery down time, the often long time duration needed to explore the entire section area, the frequent cumbersome number of devices that needs to be handled simultaneously, or the impossibility to perform intrusive tests. In the case of non-intrusive flow profiling methods based on acoustic techniques, previous methods concentrated on using a large number of acoustic transducers placed around the measured section. Although feasible, this approach presents several major drawbacks such as a complicated signal timing, transmission, acquisition and recording system, resulting in a relative high cost of operation. In addition, because of the geometrical constraints, a desired number of sensors may not be installed. Recent results in acoustic flow metering based on wide band signals and adaptive beamforming proved that it is possible to achieve flow velocity profiles using less acoustic transducers. In a normal acoustic time of flight path the transducers are both emitters and receivers, sequentially changing their roles. In the new configuration, proposed in this paper, two new receivers are added on each side. Since the beam angles of each acoustic transducer are wide enough the newly added transducers can receive the transmitted signals and additional time of flight estimation can be done. Thus, several flow

  12. Acoustic measurements of the sound-speed profile in the bubbly wake formed by a small motor boat.

    PubMed

    Vagle, Svein; Burch, Holly

    2005-01-01

    In situ measurements of the bubble field within wakes generated by a small motorboat show that the bubble field, shortly after the initial turbulent generation period, consists mainly of bubbles with radii between 20 and 200 microm. The subsequent dispersion of the wake field can be described using a model that includes bubble buoyancy and dissolution only, and the air volume fraction within the wakes decay exponentially with an e-folding time of between 40 and 60 s. Simultaneous measurements of sound propagating through the bubbly wake exhibit spectral banding due to waveguide propagation. Inversions using the inverse-square theory developed by Buckingham [Philos. Trans. R. Soc. London, Ser. A 335, 513-555 (1991)] show that this acoustic inversion technique provide a viable means of estimating the low-frequency sound-speed profile in an upward refractive bubble layer when dispersion can be neglected.

  13. Application of the loop method for correcting acoustic doppler current profiler discharge measurements biased by sediment transport

    USGS Publications Warehouse

    Mueller, David S.; Wagner, Chad R.

    2006-01-01

    A systematic bias in discharge measurements made with an acoustic Doppler current profiler (ADCP) is attributed to the movement of sediment near the streambed-an issue widely acknowledged by the scientific community. This systematic bias leads to an underestimation of measured velocity and discharge. The integration of a differentially corrected Global Positioning System (DGPS) to track the movement of the ADCP can be used to avoid the systematic bias associated with a moving bed. DGPS systems, however, cannot provide consistently accurate positions because of multipath errors and satellite signal reception problems on waterways with dense tree canopy along the banks, in deep valleys or canyons, and near bridges. An alternative method of correcting for the moving-bed bias was investigated by the U.S. Geological Survey.

  14. Studies of the acoustic transmission characteristics of coaxial nozzles with inverted velocity profiles: Comprehensive data report. [nozzle transfer functions

    NASA Technical Reports Server (NTRS)

    Dean, P. D.; Salikuddin, M.; Ahuja, K. K.; Plumblee, H. E.; Mungur, P.

    1979-01-01

    The efficiency of internal noise radiation through a coannular exhaust nozzle with an inverted velocity profile was studied. A preliminary investigation was first undertaken (1) to define the test parameters which influence the internal noise radiation; (2) to develop a test methodology which could realistically be used to examine the effects of the test parameters; and (3) to validate this methodology. The result was the choice of an acoustic impulse as the internal noise source in the jet nozzles. Noise transmission characteristics of a coannular nozzle system were then investigated. In particular, the effects of fan convergence angle, core extension length to annulus height ratio and flow Mach numbers and temperatures were studied. Relevant spectral data only is presented in the form of normalized nozzle transfer function versus nondimensional frequency.

  15. Measurement of velocities with an acoustic velocity meter, one side-looking and two upward-looking acoustic Doppler current profilers in the Chicago Sanitary and Ship Canal, Romeoville, Illinois

    USGS Publications Warehouse

    Oberg, Kevin A.; Duncker, James J.

    1999-01-01

    In 1998, a prototype 300 kHz, side-looking Acoustic Doppler Current Profiler (ADCP) was deployed in the Chicago Sanitary and Ship Canal (CSSC) at Romeoville, Illinois. Additionally, two upward-looking ADCP's were deployed in the same acoustic path as the side-looking ADCP and in the reach defined by the upstream and downstream acoustic velocity meter (AVM) paths. All three ADCP's were synchronized to the AVM clock at the gaging station so that data were sampled simultaneously. The three ADCP's were deployed for six weeks measuring flow velocities from 0.0 to 2.5 ft/s. Velocities measured by each ADCP were compared to AVM path velocities and to velocities measured by the other ADCP's.

  16. Evaluation of the resolution of a metamaterial acoustic leaky wave antenna.

    PubMed

    Naify, Christina J; Rogers, Jeffery S; Guild, Matthew D; Rohde, Charles A; Orris, Gregory J

    2016-06-01

    Acoustic antennas have long been utilized to directionally steer acoustic waves in both air and water. Typically, these antennas are comprised of arrays of active acoustic elements, which are electronically phased to steer the acoustic profile in the desired direction. A new technology, known as an acoustic leaky wave antenna (LWA), has recently been shown to achieve directional steering of acoustic waves using a single active transducer coupled to a transmission line passive aperture. The LWA steers acoustic energy by preferential coupling to an input frequency and can be designed to steer from backfire to endfire, including broadside. This paper provides an analysis of resolution as a function of both input frequency and antenna length. Additionally, the resolution is compared to that achieved using an array of active acoustic elements.

  17. Experimental validation of the directional sensitivity of the acoustic radiation force to particle diameter

    NASA Astrophysics Data System (ADS)

    Ran, Weiyu; Saylor, J. R.

    2013-11-01

    A review of existing theories for the acoustic radiation force on a particle reveals a contradiction. Some theories predict that this force exhibits a change in sign at a critical particle diameter (all other parameters held constant), while other theories predict no such sign change. To ascertain which result is correct, experiments were conducted using an ultrasonic standing wave field in air. Particles were injected into this field whereupon, as expected, they migrated toward the pressure nodes of the standing wave field. The average diameter of these particles was gradually decreased. Under such conditions, the particles should either (i) continue to migrate to the pressure nodes, or (ii) migrate to the pressure anti-nodes at a critical diameter, if a change in sign of the acoustic radiation force exists. The results of these experiments will be presented, along with their implications on extant theories.

  18. A Power Analysis and Recommended Study Design to Directly Detect Population Level Consequences of Acoustic Disturbance

    DTIC Science & Technology

    2015-09-30

    quantify potential human impacts on the health of beaked whale populations ?” (i.e, what is a recommended study design for doing this?). Quantifying...effectiveness of Navy funds for monitoring population health of beaked whales and human impacts thereon. RELATED PROJECTS Moretti, David...Detect Population -Level Consequences of Acoustic Disturbance Jeffrey Moore NOAA Southwest Fisheries Science Center 8901 La Jolla Shores Drive

  19. Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound.

    PubMed

    Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K Kirk

    2016-02-04

    Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca(2+) and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity.

  20. Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound

    NASA Astrophysics Data System (ADS)

    Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K. Kirk

    2016-02-01

    Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca2+ and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity.

  1. Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires

    PubMed Central

    Kargar, Fariborz; Debnath, Bishwajit; Kakko, Joona-Pekko; Säynätjoki, Antti; Lipsanen, Harri; Nika, Denis L.; Lake, Roger K.; Balandin, Alexander A.

    2016-01-01

    Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin—Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined acoustic phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are in excellent agreement with theory. The phonon confinement effects result in a decrease in the phonon group velocity along the nanowire axis and changes in the phonon density of states. The obtained results can lead to more efficient nanoscale control of acoustic phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices. PMID:27830698

  2. Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound

    PubMed Central

    Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K. Kirk

    2016-01-01

    Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca2+ and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity. PMID:26843283

  3. Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires

    DOE PAGES

    Kargar, Fariborz; Debnath, Bishwajit; Kakko, Joona -Pekko; ...

    2016-11-10

    Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin-Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined acoustic phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are inmore » excellent agreement with theory. The phonon confinement effects result in a decrease in the phonon group velocity along the nanowire axis and changes in the phonon density of states. Furthermore, the obtained results can lead to more efficient nanoscale control of acoustic phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices.« less

  4. Spatial and temporal frequency domain laser-ultrasound applied in the direct measurement of dispersion relations of surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Grünsteidl, Clemens; Veres, István A.; Roither, Jürgen; Burgholzer, Peter; Murray, Todd W.; Berer, Thomas

    2013-01-01

    We present a laser-ultrasound measurement technique which combines adjustable spatial and temporal modulation of the excitation laser beam. Our method spreads the intensity of an amplitude modulated continuous wave laser over a micro-scale pattern on the sample surface to excite surface acoustic waves. The excitation pattern consists of parallel, equidistant lines and the waves generated from the individual lines interfere on the sample surface. Measurement is done in the spatial-temporal frequency domain allowing the direct determination of dispersion relations. The technique performs with high signal-to-noise-ratios and low peak power densities on the sample.

  5. Dental hygiene practice: international profile and future directions.

    PubMed

    Johnson, P M

    1992-12-01

    Results of an international survey on dental hygiene are reported. The survey was conducted in 1988 through the International Dental Hygienists' Federation as part of a project to establish and maintain an international database on the profession. Information was collected by mail from national dental hygienist associations, using a 40-item questionnaire developed for the purpose; preliminary tabulations were validated by the associations. Information is presented for 13 countries-Australia, Canada, Denmark, Italy, Japan, Korea, The Netherlands, Nigeria, Norway, Sweden, Switzerland, the United States and the United Kingdom. Characteristics include historical development, numbers and distribution, education, regulation, scope of practice, employment settings and conditions, professional organisation, and perceived oral health and professional issues. The profiles and issues are examined in the light of broader socio-economic, demographic, epidemiological, technological and policy-related trends and changes. Implications for future health and organisational planning are noted.

  6. Effects of air flow directions on composting process temperature profile

    SciTech Connect

    Kulcu, Recep; Yaldiz, Osman

    2008-07-01

    In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO{sub 2} and O{sub 2} ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2.

  7. Comparison of buoy-mounted 74-kHz acoustic Doppler current profilers with vector-measuring current meters

    NASA Technical Reports Server (NTRS)

    Winant, Clinton; Mettlach, Theodore; Larson, Sigurd

    1994-01-01

    In December 1991, the National Data Buoy Center (NDBC) deployed two meteorological buoys in the Southern California Bight on a transect between San Diego and San Clemente Island. Each buoy consisted of a 10-m discus hull instrumented to measure a suite of meteorological parameters, and, for the first time in the NDBC buoy program, acoustic Doppler current profilers (ADCPs) were included to gather hourly current profiles beneath the two buoys. Moorings instrumented with seven vector-measuring current meters (VMCMs) were deployed adjacent to the NDBC buoys for several months and provided current observations for comparison with the ADCP measurements. When wave-induced buoy motion is not overly large, the observations of horizontal current made by the ADCP and the VMCM are highly correlated. Time series of differences between ADCP and VMCM measurements are characterized by a mean difference (bias error) of about 0.01 m/s and standard deviation of about 0.035 m/s for 1-h observations. Estimates of current spectra from ADCP and VMCM records suggest that the ADCP system can be characterized by a white noise level of 2 x 10(exp -3) sq m/sq s/cph. However, when the in situ environment is such that large surface waves are present (including breaking waves and whitecaps), erroneous current values are usually reported by the ADCP. Mean values of vertical velocities reported by the ADCP appear to be much larger than what could be physically expected and are therefore deemed unreliable.

  8. Making direct use of canopy profiles in vegetation - atmosphere coupling

    NASA Astrophysics Data System (ADS)

    Ryder, James; Polcher, Jan; Peylin, Philippe; Ottlé, Catherine; Chen, Yiying; van Gorsel, Eva; Haverd, Vanessa; McGrath, Matthew; Naudts, Kim; Otto, Juliane; Valade, Aude; Luyssaert, Sebastiaan

    2015-04-01

    Most coupled land-surface regional models use the 'big-leaf' approach for simulating the sensible and latent heat fluxes of different vegetation types. However, there has been a progression in the types of questions being asked of these models, such as the consequences of land-use change or the behaviour of BVOCs and aerosol. In addition, recent years has seen growth in the availability of in-canopy datasets across a broaded range of species, with which to calibrate these simulations. Hence, there is now an argument for transferring some of the techniques and processes previously used in local, site-based land surface models to the land surface components of models which operate on a regional or even global scale. We describe here the development and evaluation of a vertical canopy energy budget model (Ryder, J et al., 2014) that can be coupled to an atmospheric model such as LMDz. Significantly, the model preserves the implicit coupling of the land-surface to atmosphere interface, which means that run-time efficiences are preserved. This is acheived by means of an interface based on the approach of Polcher et al. (1998) and Best et al. (2004), but newly developed for a canopy column. The model makes use of techniques from site-based models, such as the calculation of vertical turbulence statistics using a second-order closure model (Massman & Weil, 1999), and the distribution of long-wave and short-wave radiation over the profile, the latter using an innovate multilayer albedo scheme (McGrath et al., in prep.). Complete profiles of atmospheric temperature and specific humidity are now calculated, in order to simulate sensible and latent heat fluxes, as well as the leaf temperature at each level in the model. The model is shown to perform stably, and reproduces well flux measurements at an initial test site, across a time period of several days, or over the course of a year. Further applications of the model might be to simulate mixed canopies, the light

  9. Acoustic pattern variations in the female-directed birdsongs of a colony of laboratory-bred zebra finches.

    PubMed

    Helekar; Marsh; Viswanath; Rosenfield

    2000-04-03

    The acoustic profile of the zebra finch song is characterized by a series of identical repeating units, each comprising a distinctive sequence of acoustic elements, called syllables. Here, we perform an analysis of song pattern deviations caused by variabilities in the production of song syllables. Zebra finches produce four different kinds of syllable variabilities-syllable deletions, single or double syllable insertions, syllable alterations, and syllable repetitions. All these variabilities, with the exception of repetitions, are present in songs of more than two-thirds of the normal adult birds; repetitions are present in less than one-fifth of birds. The frequency of occurrence of these variabilities is independent of the amount of singing, suggesting that they are unlikely to result simply from singing-induced physiological changes such as fatigue. Their frequencies in tutor-deprived birds are not significantly different from those in normal birds, indicating that they are unlikely to be acquired due to deficiencies in tutor-dependent learning. The types, patterns of occurrence and relative frequencies of these song syllable variabilities might reveal insights into the functioning of the song motor control pathway.

  10. Ligand-directed profiling of organelles with internalizing phage libraries.

    PubMed

    Dobroff, Andrey S; Rangel, Roberto; Guzman-Roja, Liliana; Salmeron, Carolina C; Gelovani, Juri G; Sidman, Richard L; Bologa, Cristian G; Oprea, Tudor I; Brinker, C Jeffrey; Pasqualini, Renata; Arap, Wadih

    2015-02-02

    Phage display is a resourceful tool to, in an unbiased manner, discover and characterize functional protein-protein interactions, create vaccines, and engineer peptides, antibodies, and other proteins as targeted diagnostic and/or therapeutic agents. Recently, our group has developed a new class of internalizing phage (iPhage) for ligand-directed targeting of organelles and to identify molecular pathways within live cells. This unique technology is suitable for applications ranging from fundamental cell biology to drug development. This unit describes the methods for generating and screening the iPhage display system, and explains how to select and validate candidate internalizing homing peptide.

  11. Ligand-directed profiling of organelles with internalizing phage libraries

    PubMed Central

    Dobroff, Andrey S.; Rangel, Roberto; Guzman-Roja, Liliana; Salmeron, Carolina C.; Gelovani, Juri G.; Sidman, Richard L.; Bologa, Cristian G.; Oprea, Tudor I.; Brinker, C. Jeffrey; Pasqualini, Renata; Arap, Wadih

    2015-01-01

    Phage display is a resourceful tool to, in an unbiased manner, discover and characterize functional protein-protein interactions, to create vaccines, and to engineer peptides, antibodies, and other proteins as targeted diagnostic and/or therapeutic agents. Recently, our group has developed a new class of internalizing phage (iPhage) for ligand-directed targeting of organelles and/or to identify molecular pathways within live cells. This unique technology is suitable for applications ranging from fundamental cell biology to drug development. Here we describe the method for generating and screening the iPhage display system, and explain how to select and validate candidate internalizing homing peptide. PMID:25640897

  12. Predicting direction detection thresholds for arbitrary translational acceleration profiles in the horizontal plane

    PubMed Central

    Soyka, Florian; Robuffo Giordano, Paolo; Beykirch, Karl

    2011-01-01

    In previous research, direction detection thresholds have been measured and successfully modeled by exposing participants to sinusoidal acceleration profiles of different durations. In this paper, we present measurements that reveal differences in thresholds depending not only on the duration of the profile, but also on the actual time course of the acceleration. The measurements are further explained by a model based on a transfer function, which is able to predict direction detection thresholds for all types of acceleration profiles. In order to quantify a participant’s ability to detect the direction of motion in the horizontal plane, a four-alternative forced-choice task was implemented. Three types of acceleration profiles (sinusoidal, trapezoidal and triangular) were tested for three different durations (1.5, 2.36 and 5.86 s). To the best of our knowledge, this is the first study which varies both quantities (profile and duration) in a systematic way within a single experiment. The lowest thresholds were found for trapezoidal profiles and the highest for triangular profiles. Simulations for frequencies lower than the ones actually measured predict a change from this behavior: Sinusoidal profiles are predicted to yield the highest thresholds at low frequencies. This qualitative prediction is only possible with a model that is able to predict thresholds for different types of acceleration profiles. Our modeling approach represents an important advancement, because it allows for a more general and accurate description of perceptual thresholds for simple and complex translational motions. PMID:21234751

  13. Predicting direction detection thresholds for arbitrary translational acceleration profiles in the horizontal plane.

    PubMed

    Soyka, Florian; Robuffo Giordano, Paolo; Beykirch, Karl; Bülthoff, Heinrich H

    2011-03-01

    In previous research, direction detection thresholds have been measured and successfully modeled by exposing participants to sinusoidal acceleration profiles of different durations. In this paper, we present measurements that reveal differences in thresholds depending not only on the duration of the profile, but also on the actual time course of the acceleration. The measurements are further explained by a model based on a transfer function, which is able to predict direction detection thresholds for all types of acceleration profiles. In order to quantify a participant's ability to detect the direction of motion in the horizontal plane, a four-alternative forced-choice task was implemented. Three types of acceleration profiles (sinusoidal, trapezoidal and triangular) were tested for three different durations (1.5, 2.36 and 5.86 s). To the best of our knowledge, this is the first study which varies both quantities (profile and duration) in a systematic way within a single experiment. The lowest thresholds were found for trapezoidal profiles and the highest for triangular profiles. Simulations for frequencies lower than the ones actually measured predict a change from this behavior: Sinusoidal profiles are predicted to yield the highest thresholds at low frequencies. This qualitative prediction is only possible with a model that is able to predict thresholds for different types of acceleration profiles. Our modeling approach represents an important advancement, because it allows for a more general and accurate description of perceptual thresholds for simple and complex translational motions.

  14. The Relation of Profile Elevation in the Self-Directed Search to Personality Variables.

    ERIC Educational Resources Information Center

    Fuller, Bret E.; Holland, John L.; Johnston, Joseph A.

    1999-01-01

    The NEO Personality Inventory, Personal Styles Inventory, and Self-Directed Search (SDS) were completed by 319 participants. Higher profile elevation (total score of SDS scales) was associated with higher openness to experience and extraversion and lower depressive personality. Results help interpret high or low SDS profiles. (SK)

  15. MEASURING VERTICAL PROFILES OF HYDRAULIC CONDUCTIVITY WITH IN SITU DIRECT-PUSH METHODS

    EPA Science Inventory

    U.S. EPA (Environmental Protection Agency) staff developed a field procedure to measure hydraulic conductivity using a direct-push system to obtain vertical profiles of hydraulic conductivity. Vertical profiles were obtained using an in situ field device-composed of a
    Geopr...

  16. MEASURING VERTICAL PROFILES OF HYDRAULIC CONDUCTIVITY WITH IN SITU DIRECT-PUSH METHODS

    EPA Science Inventory

    U.S. EPA (Environmental Protection Agency) staff developed a field procedure to measure hydraulic conductivity using a direct-push system to obtain vertical profiles of hydraulic conductivity. Vertical profiles were obtained using an in situ field device-composed of a
    Geopr...

  17. Acoustic Doppler current profiler applications used in rivers and estuaries by the U.S. Geological Survey

    USGS Publications Warehouse

    Gotvald, Anthony J.; Oberg, Kevin A.

    2009-01-01

    The U.S. Geological Survey (USGS) has collected streamflow information for the Nation's streams since 1889. Streamflow information is used to predict floods, manage and allocate water resources, design engineering structures, compute water-quality loads, and operate water-control structures. The current (2007) size of the USGS streamgaging network is over 7,400 streamgages nationwide. The USGS has progressively improved the streamgaging program by incorporating new technologies and techniques that streamline data collection while increasing the quality of the streamflow data that are collected. The single greatest change in streamflow measurement technology during the last 100 years has been the development and application of high frequency acoustic instruments for measuring streamflow. One such instrument, the acoustic Doppler current profiler (ADCP), is rapidly replacing traditional mechanical current meters for streamflow measurement (Muste and others, 2007). For more information on how an ADCP works see Simpson (2001) or visit http://hydroacoustics.usgs.gov/. The USGS has used ADCPs attached to manned or tethered boats since the mid-1990s to measure streamflow in a wide variety of conditions (fig. 1). Recent analyses have shown that ADCP streamflow measurements can be made with similar or greater accuracy, efficiency, and resolution than measurements made using conventional current-meter methods (Oberg and Mueller, 2007). ADCPs also have the ability to measure streamflow in streams where traditional current-meter measurements previously were very difficult or costly to obtain, such as streams affected by backwater or tides. In addition to streamflow measurements, the USGS also uses ADCPs for other hydrologic measurements and applications, such as computing continuous records of streamflow for tidally or backwater affected streams, measuring velocity fields with high spatial and temporal resolution, and estimating suspended-sediment concentrations. An overview

  18. Direct measurement of coherent subterahertz acoustic phonons mean free path in GaAs

    NASA Astrophysics Data System (ADS)

    Legrand, R.; Huynh, A.; Jusserand, B.; Perrin, B.; Lemaître, A.

    2016-05-01

    The phonon mean free path is generally inferred from the measurement of thermal conductivity and we are still lacking precise information on this quantity. Recent advances in the field of high-frequency phonons transduction using semiconductor superlattices give the opportunity to fill this gap. We present experimental results on the attenuation of longitudinal acoustic phonons in GaAs in the frequency and temperature ranges 0.2-1 THz and 10-80 K respectively. Surprisingly, we observe a plateau in the frequency dependence of the attenuation above 0.7 THz, that we ascribe to a breakdown of Herring processes.

  19. Direct laboratory observation of fluid distribution and its influence on acoustic properties of patchy saturated rocks

    NASA Astrophysics Data System (ADS)

    Lebedev, M.; Clennell, B.; Pervukhina, M.; Shulakova, V.; Mueller, T.; Gurevich, B.

    2009-04-01

    Porous rocks in hydrocarbon reservoirs are often saturated with a mixture of two or more fluids. Interpretation of exploration seismograms requires understanding of the relationship between distribution of the fluids patches and acoustic properties of rocks. The sizes of patches as well as their distribution affect significantly the seismic response. If the size of the fluid patch is smaller than the diffusion wavelength then pressure equilibration is achieved and the bulk modulus of the rock saturated with a mixture is defined by the Gassmann equations (Gassmann, 1951) with the saturation-weighted average of the fluid bulk modulus given by Wood's law (Wood, 1955, Mavko et al., 1998). If the fluid patch size is much larger than the diffusion wavelength then there is no pressure communication between different patches. In this case, fluid-flow effects can be neglected and the overall rock may be considered equivalent to an elastic composite material consisting of homogeneous parts whose properties are given by Gassmann theory with Hill's equation for the bulk modulus (Hill, 1963, Mavko et al., 1998). At intermediate values of fluid saturation the velocity-saturation relationship is significantly affected by the fluid patch distribution. In order to get an improved understanding of factors influencing the patch distribution and the resulting seismic wave response we performed simultaneous measurements of P-wave velocities and rock sample CT imaging. The CT imaging allows us to map the fluid distribution inside rock sample during saturation (water imbibition). We compare the experimental results with theoretical predictions. In this paper we will present results of simultaneous measurements of longitudinal wave velocities and imaging mapping of fluid distribution inside rock sample during sample saturation. We will report results of two kinds of experiments: "dynamic" and "quasi static" saturation. In both experiments Casino Cores Otway Basin sandstone, Australia core

  20. Design and implementation of an omni-directional underwater acoustic micro-modem based on a low-power micro-controller unit.

    PubMed

    Won, Tae-Hee; Park, Sung-Joon

    2012-01-01

    For decades, underwater acoustic communication has been restricted to the point-to-point long distance applications such as deep sea probes and offshore oil fields. For this reason, previous acoustic modems were typically characterized by high data rates and long working ranges at the expense of large size and high power consumption. Recently, as the need for underwater wireless sensor networks (UWSNs) has increased, the research and development of compact and low-power consuming communication devices has become the focus. From the consideration that the requisites of acoustic modems for UWSNs are low power consumption, omni-directional beam pattern, low cost and so on, in this paper, we design and implement an omni-directional underwater acoustic micro-modem satisfying these requirements. In order to execute fast digital domain signal processing and support flexible interfaces with other peripherals, an ARM Cortex-M3 is embedded in the micro-modem. Also, for the realization of small and omni-directional properties, a spherical transducer having a resonant frequency of 70 kHz and a diameter of 34 mm is utilized for the implementation. Physical layer frame format and symbol structure for efficient packet-based underwater communication systems are also investigated. The developed acoustic micro-modem is verified analytically and experimentally in indoor and outdoor environments in terms of functionality and performance. Since the modem satisfies the requirements for use in UWSNs, it could be deployed in a wide range of applications requiring underwater acoustic communication.

  1. Design and Implementation of an Omni-Directional Underwater Acoustic Micro-Modem Based on a Low-Power Micro-Controller Unit

    PubMed Central

    Won, Tae-Hee; Park, Sung-Joon

    2012-01-01

    For decades, underwater acoustic communication has been restricted to the point-to-point long distance applications such as deep sea probes and offshore oil fields. For this reason, previous acoustic modems were typically characterized by high data rates and long working ranges at the expense of large size and high power consumption. Recently, as the need for underwater wireless sensor networks (UWSNs) has increased, the research and development of compact and low-power consuming communication devices has become the focus. From the consideration that the requisites of acoustic modems for UWSNs are low power consumption, omni-directional beam pattern, low cost and so on, in this paper, we design and implement an omni-directional underwater acoustic micro-modem satisfying these requirements. In order to execute fast digital domain signal processing and support flexible interfaces with other peripherals, an ARM Cortex-M3 is embedded in the micro-modem. Also, for the realization of small and omni-directional properties, a spherical transducer having a resonant frequency of 70 kHz and a diameter of 34 mm is utilized for the implementation. Physical layer frame format and symbol structure for efficient packet-based underwater communication systems are also investigated. The developed acoustic micro-modem is verified analytically and experimentally in indoor and outdoor environments in terms of functionality and performance. Since the modem satisfies the requirements for use in UWSNs, it could be deployed in a wide range of applications requiring underwater acoustic communication. PMID:22438765

  2. Estimating hydrodynamic roughness in a wave-dominated environment with a high-resolution acoustic Doppler profiler

    USGS Publications Warehouse

    Lacy, J.R.; Sherwood, C.R.; Wilson, D.J.; Chisholm, T.A.; Gelfenbaum, G.R.

    2005-01-01

    Hydrodynamic roughness is a critical parameter for characterizing bottom drag in boundary layers, and it varies both spatially and temporally due to variation in grain size, bedforms, and saltating sediment. In this paper we investigate temporal variability in hydrodynamic roughness using velocity profiles in the bottom boundary layer measured with a high-resolution acoustic Doppler profiler (PCADP). The data were collected on the ebb-tidal delta off Grays Harbor, Washington, in a mean water depth of 9 m. Significant wave height ranged from 0.5 to 3 m. Bottom roughness has rarely been determined from hydrodynamic measurements under conditions such as these, where energetic waves and medium-to-fine sand produce small bedforms. Friction velocity due to current u*c and apparent bottom roughness z0a were determined from the PCADP burst mean velocity profiles using the law of the wall. Bottom roughness kB was estimated by applying the Grant-Madsen model for wave-current interaction iteratively until the model u*c converged with values determined from the data. The resulting kB values ranged over 3 orders of magnitude (10-1 to 10-4 m) and varied inversely with wave orbital diameter. This range of kB influences predicted bottom shear stress considerably, suggesting that the use of time-varying bottom roughness could significantly improve the accuracy of sediment transport models. Bedform height was estimated from kB and is consistent with both ripple heights predicted by empirical models and bedforms in sonar images collected during the experiment. Copyright 2005 by the American Geophysical Union.

  3. Flight effects on the aerodynamic and acoustic characteristics of inverted profile coannular nozzles

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    The effect of forward flight on the jet noise of coannular exhaust nozzles, suitable for Variable Stream Control Engines (VSCE), was investigated in a series of wind tunnel tests. The primary stream properties were maintained constant at 300 mps and 394 K. A total of 230 acoustic data points was obtained. Force measurement tests using an unheated air supply covered the same range of tunnel speeds and nozzle pressure ratios on each of the nozzle configurations. A total of 80 points was taken. The coannular nozzle OASPL and PNL noise reductions observed statically relative to synthesized values were basically retained under simulated flight conditions. The effect of fan to primary stream area ratio on flight effects was minor. At take-off speed, the peak jet noise for a VSCE was estimated to be over 6 PNdB lower than the static noise level. High static thrust coefficients were obtained for the basic coannular nozzles, with a decay of 0.75 percent at take-off speeds.

  4. Ultrasound tomography for simultaneous reconstruction of acoustic density, attenuation, and compressibility profiles.

    PubMed

    Mojabi, Pedram; LoVetri, Joe

    2015-04-01

    A fast and efficient forward scattering solver is developed for use in ultrasound tomography. The solver is formulated so as to enable the calculation of scattering from large and relatively high-contrast objects with inhomogeneous physical properties that vary simultaneously in acoustic attenuation, compressibility, and density. It is based on the method of moments in conjunction with a novel implementation of the conjugate gradient algorithm which requires the use of the adjoints of the scattering operators. The solver takes advantage of the symmetric block Toeplitz matrix with symmetric Toeplitz blocks property of the Green's function matrix to increase efficiency and only stores the first row of this matrix to reduce memory requirements. This row is then used for the matrix-vector multiplication using the fast Fourier transform technique, thus, resulting in the computational complexity of O(n log n). The marching-on-source technique is also used to provide a good initial guess which allows the conjugate gradient technique to converge faster than initializing with an arbitrary guess. This feature is important in tomographic inversion algorithms which require that the object to be imaged be interrogated via several incident fields. Forward scattering and inversion examples, based on the Conjugate Gradient Least Squares regularized Born Iterative Method, are shown, in two-dimensions, for objects varying in all three physical properties.

  5. 2 kHz high power smart transducer for acoustic sub-bottom profiling applications

    NASA Astrophysics Data System (ADS)

    Sathishkumar, R.

    2013-09-01

    In this study, a 2 kHz Tonpilz projector was designed using a Terfenol-D and modeled in ATILA. For the purpose of modeling studies, it has been determined that a radiating head mass exhibits better transmitting current response (TCR) at 136 mm diameter, where the resonance occurs at 2.4 kHz and the peak value of 118 dB re 1 μPa/A at 1 m occurs at 12 kHz. Also bolt at a 46 mm distance from the center of the head mass offers resonance at 2.4 kHz, and the peak value of 115.3 dB re 1 μPa/A at 1m occurs at 11.5 kHz. This optimized design is fabricated and molded with polyurethane of 3 mm thickness. The prototype was tested at the Acoustic Test Facility (ATF) of National Institute of Ocean Technology (NIOT) for its underwater performances. Based on the result, the fundamental resonance was determined to be 2.18 kHz and the peak value of TCR of 182 dB re 1 μPa/A at 1m occurs at 14 kHz. The maximum value of the RS was found to be -190 dB re 1V/μPa at 1m at a frequency of 2.1 kHz.

  6. Direct imaging of delayed magneto-dynamic modes induced by surface acoustic waves.

    PubMed

    Foerster, Michael; Macià, Ferran; Statuto, Nahuel; Finizio, Simone; Hernández-Mínguez, Alberto; Lendínez, Sergi; Santos, Paulo V; Fontcuberta, Josep; Hernàndez, Joan Manel; Kläui, Mathias; Aballe, Lucia

    2017-09-01

    The magnetoelastic effect-the change of magnetic properties caused by the elastic deformation of a magnetic material-has been proposed as an alternative approach to magnetic fields for the low-power control of magnetization states of nanoelements since it avoids charge currents, which entail ohmic losses. Here, we have studied the effect of dynamic strain accompanying a surface acoustic wave on magnetic nanostructures in thermal equilibrium. We have developed an experimental technique based on stroboscopic X-ray microscopy that provides a pathway to the quantitative study of strain waves and magnetization at the nanoscale. We have simultaneously imaged the evolution of both strain and magnetization dynamics of nanostructures at the picosecond time scale and found that magnetization modes have a delayed response to the strain modes, adjustable by the magnetic domain configuration. Our results provide fundamental insight into magnetoelastic coupling in nanostructures and have implications for the design of strain-controlled magnetostrictive nano-devices.Understanding the effects of local dynamic strain on magnetization may help the development of magnetic devices. Foerster et al. demonstrate stroboscopic imaging that allows the observation of both strain and magnetization dynamics in nickel when surface acoustic waves are driven in the substrate.

  7. Acoustic energy propagation around railways

    NASA Astrophysics Data System (ADS)

    Cizkova, Petra

    2017-09-01

    The article deals with the issues of acoustic energy propagation around railways. The research subject was noise emission spreading into the surroundings during the passage of trains over a directly travelled steel bridge construction. Noise emissions were measured using direct measurements in the field. The measurements were performed in two measurement profiles. The noise exposures A LAE measured near the steel bridge construction were compared against the noise exposures A LAE captured on an open track. From the difference of these data, the noise level of the steel bridge structure was determined. Part of the research was to evaluate the effect of the reconstruction of the railway track superstructure on the acoustic situation in the given section of the railway track. The article describes the methodology of measurements, including the processing and evaluation of measured data. The article points out the noise levels of the steel bridge construction and assesses changes in the acoustic situation after the reconstruction.

  8. Irregular reflection of weak acoustic shock pulses on rigid boundaries : Schlieren experiments and direct numerical simulation based on a Navier-Stokes solver

    NASA Astrophysics Data System (ADS)

    Desjouy, Cyril; Ollivier, Sébastien; Marsden, Olivier; Karzova, Maria; Blanc-Benon, Philippe

    2016-02-01

    The local interactions occurring between incident and reflected shock waves in the vicinity of rigid surfaces are investigated. Both regular and irregular — also called von Neumann — regimes of reflection are studied, via experimental and numerical simulations. Shock waves are produced experimentally with a 20 kV electrical spark source which allows the generation of spherically diverging acoustic shocks. The behaviour of the resulting weak acoustic shocks near rigid boundaries is visualized with a Schlieren optical technique which allows the spatial structure of the shocks to be studied. In particular, the evolution of the Mach stem forming above a flat surface is examined, and its height is observed to be directly linked to the angle of incidence and the pressure amplitude of the incident shock. The propagation of an acoustic shock between two parallel rigid boundaries is also studied. It is shown that the strong interactions between the Mach stems emerging from the two boundaries can lead to a drastic modification of the morphology of the acoustic field in the waveguide. Experimental results are compared to numerical results obtained from high-order finite-difference based simulations of the 2D Navier-Stokes equations. The good agreement between the experimental distribution of the acoustic field and numerical results suggests that numerical simulations are promising as a predictive tool to study nonlinear acoustic propagation of acoustic waves in complex geometrical configurations with rigid boundaries.

  9. Sounding out erosion on the Mekong river banks: insights from combined terrestrial laser scanning, multibeam echo sounding and acoustic Doppler profiling

    NASA Astrophysics Data System (ADS)

    Best, J.; Hackney, C. R.; Leyland, J.; Darby, S. E.; Parsons, D. R.; Aalto, R. E.; Nicholas, A. P.

    2015-12-01

    Knowledge of bank erosion processes and rates along very large rivers remains incomplete, primarily due to the difficulties of obtaining morphological and flow data close to the bank across various flow stages. Moreover, obtaining such process information through the entire flow and bank depth has also proved challenging. Here, we present data from a series of high spatial resolution topographic (Terrestrial Laser Scanner and Multibeam Echo Sounder) and flow (Acoustic Doppler Current Profiler) surveys undertaken on the Mekong River, Cambodia, which reveal the temporal and spatial evolution of a series of embayments on the outer bank of a large meander. These techniques yield unique data that reveal how the flow field responds to the morphology of the outer bank and subaqueous slump blocks. Specifically, we show that in the early stage of embayment growth, deposited slump blocks induce flow upwelling and bank-directed flow that enhances bank erosion. Our data also suggest that as the initial erosion process continues, a threshold embayment size is reached. Below this threshold, flow separation acts to enhance embayment growth along with the fluid dynamic effects of slump blocks, but above the threshold size, the separation zone in the embayments acts as a protective layer, thus slowing erosion. This field data allows proposition of a new conceptual model of embayment evolution.

  10. Chemical Probes to Directly Profile Palmitoleoylation of Proteins.

    PubMed

    Zheng, Baohui; Jarugumilli, Gopala K; Chen, Baoen; Wu, Xu

    2016-11-03

    Palmitoleoylation is a unique fatty acylation of proteins in which a monounsaturated fatty acid, palmitoleic acid (C16:1), is covalently attached to a protein. Wnt proteins are known to be palmitoleoylated by cis-Δ9 palmitoleate at conserved serine residues. O-palmitoleoylation plays a critical role in regulating Wnt secretion, binding to the receptors, and in the dynamics of Wnt signaling. Therefore, protein palmitoleoylation is important in tissue homeostasis and tumorigenesis. Chemical probes based on saturated fatty acids, such as ω-alkynyl palmitic acid (Alk-14 or Alk-C16 ), have been used to study Wnt palmitoleoylation. However, such probes require prior conversion to the unsaturated fatty acid by stearoyl-CoA desaturase (SCD) in cells, significantly decreasing their selectivity and efficiency for studying protein palmitoleoylation. We synthesized and characterized ω-alkynyl cis- and trans-palmitoleic acids (cis- and trans-Alk-14:1) as chemical probes to directly study protein palmitoleoylation. We found that cis-Alk-14:1 could more efficiently label Wnt proteins in cells. Interestingly, the DHHC family of palmitoyl acyltransferases can charge both saturated and unsaturated fatty acids, potentially using both as acyl donors in protein palmitoylation and palmitoleoylation. Furthermore, proteomic analysis of targets labeled by these probes revealed new cis- and trans-palmitoleoylated proteins. Our studies provided new chemical tools and revealed new insights into palmitoleoylation in cell signaling.

  11. Evaluation of Backscatter in the northeastern Red Sea using a Lowered Acoustic Doppler Profiler, Simrad EK60 Echosounder and in situ Observations

    NASA Astrophysics Data System (ADS)

    Torres, D. J.; Klevjer, T. A.; Solberg, I.; Bower, A. S.; Kaartvedt, S.

    2010-12-01

    An oceanographic research cruise aboard the R/V Aegaeo was conducted in the Red Sea from 16-29 March 2010. The primary objective of the cruise was to undertake the first large-scale physical oceanographic survey of the northeastern quadrant of the Red Sea, including observations of top-to-bottom ocean currents and water properties such as temperature, salinity, dissolved oxygen, turbidity and fluorescence. Additional objectives were to take seawater samples throughout the water column for carbonate chemistry and microbial studies, and to survey the distribution of pelagic fishes using acoustic methods. A total of 111 casts were made during the cruise which covered nine transects ranging from 22°-28°N. A modified SeaBird 9/11+ rosette/CTD system equipped with a pair of upward and downward facing 300 kHz Lowered Acoustic Doppler Current Profilers (LADCP) from Teledyne RD Instruments was used for station sampling. The LADCP system is primarily used for measuring full water column absolute velocity profiles. However, this study focuses on using the LADCP echo intensity data to measure ocean backscatter. Complex methods are usually required for calibration of acoustic instruments to measure backscatter due to attenuation and absorption of sound in water. Here we present a method for data processing which eliminates the need for calibration by using a single bin at a fixed distance from the ADCP transducers. We also present data from a Simrad EK60 echosounder which collected underway acoustic data throughout the cruise. Diurnal migration patterns of mesopelagic fish (an abundant and important part of the Red Sea ecosystem) are clearly evident in both data sets. Although the LADCP (due to bin size settings optimized for water velocity measurements) cannot resolve the thinner layers of acoustic scatterers compared to the 38 kHz EK60 data, it can be a very useful tool for measuring fish and zooplankton distribution from ships not equipped with high end acoustic

  12. Picosecond x-ray strain rosette reveals direct laser excitation of coherent transverse acoustic phonons

    SciTech Connect

    Lee, Sooheyong; Williams, G. Jackson; Campana, Maria I.; Walko, Donald A.; Landahl, Eric C.

    2016-01-11

    Using a strain-rosette, we demonstrate the existence of transverse strain using time-resolved x-ray diffraction from multiple Bragg reflections in laser-excited bulk gallium arsenide. We find that anisotropic strain is responsible for a considerable fraction of the total lattice motion at early times before thermal equilibrium is achieved. Our measurements are described by a new model where the Poisson ratio drives transverse motion, resulting in the creation of shear waves without the need for an indirect process such as mode conversion at an interface. Finally, using the same excitation geometry with the narrow-gap semiconductor indium antimonide, we detected coherent transverse acoustic oscillations at frequencies of several GHz.

  13. Surface acoustic wave amplification by direct current-voltage supplied to graphene film

    NASA Astrophysics Data System (ADS)

    Insepov, Z.; Emelin, E.; Kononenko, O.; Roshchupkin, D. V.; Tnyshtykbayev, K. B.; Baigarin, K. A.

    2015-01-01

    Using a high-resolution X-Ray diffraction measurement method, the surface acoustic wave (SAW) propagation in a graphene film on the surface of a Ca3TaGa3Si2O14 (CTGS) piezoelectric crystal was investigated, where an external current was driven across the graphene film. Here, we show that the application of the DC field leads to a significant enhancement of the SAW magnitude and, as a result, to amplification of the diffraction satellites. Amplification of 33.2 dB/cm for the satellite +1, and of 13.8 dB/cm for the satellite +2, at 471 MHz has been observed where the external DC voltage of +10 V was applied. Amplification of SAW occurs above a DC field much smaller than that of a system using bulk semiconductor. Theoretical estimates are in reasonable agreement with our measurements and analysis of experimental data for other materials.

  14. Picosecond x-ray strain rosette reveals direct laser excitation of coherent transverse acoustic phonons.

    PubMed

    Lee, Sooheyong; Williams, G Jackson; Campana, Maria I; Walko, Donald A; Landahl, Eric C

    2016-01-11

    Using a strain-rosette, we demonstrate the existence of transverse strain using time-resolved x-ray diffraction from multiple Bragg reflections in laser-excited bulk gallium arsenide. We find that anisotropic strain is responsible for a considerable fraction of the total lattice motion at early times before thermal equilibrium is achieved. Our measurements are described by a new model where the Poisson ratio drives transverse motion, resulting in the creation of shear waves without the need for an indirect process such as mode conversion at an interface. Using the same excitation geometry with the narrow-gap semiconductor indium antimonide, we detected coherent transverse acoustic oscillations at frequencies of several GHz.

  15. Picosecond x-ray strain rosette reveals direct laser excitation of coherent transverse acoustic phonons

    PubMed Central

    Lee, Sooheyong; Williams, G. Jackson; Campana, Maria I.; Walko, Donald A.; Landahl, Eric C.

    2016-01-01

    Using a strain-rosette, we demonstrate the existence of transverse strain using time-resolved x-ray diffraction from multiple Bragg reflections in laser-excited bulk gallium arsenide. We find that anisotropic strain is responsible for a considerable fraction of the total lattice motion at early times before thermal equilibrium is achieved. Our measurements are described by a new model where the Poisson ratio drives transverse motion, resulting in the creation of shear waves without the need for an indirect process such as mode conversion at an interface. Using the same excitation geometry with the narrow-gap semiconductor indium antimonide, we detected coherent transverse acoustic oscillations at frequencies of several GHz. PMID:26751616

  16. A highly directional transducer for multipath mitigation in high-frequency underwater acoustic communications.

    PubMed

    Freeman, Simon E; Emokpae, Lloyd; Nicholas, Michael; Edelmann, Geoffrey F

    2015-08-01

    This paper presents a transducer design of the hollow cylinder type designed to minimize transmission multipath and the need for channel equalization over short acoustic communication distances in shallow water. Operating at 750 kHz, the half-maximum envelope of the main lobe is approximately 3°. The transducer was incorporated into a low-complexity modem system in which it acted as both transmitter and receiver. At-sea testing indicated that the system is capable of operating over horizontal distances of 5 m without evidence of multipath distortion. The system was also found to be effective as an omnidirectional transmitter/receiver in the 10-60 kHz band.

  17. An acoustic system for providing the two-phase liquid profile in oil field storage tanks.

    PubMed

    Meribout, Mahmoud; Al Naamany, Ahmed; Al Busaidi, Khamis

    2009-10-01

    The continuing need for in situ measurements of the emulsion layer between crude oil and water within oil field tanks has initiated experimental and theoretical investigations of candidate measurement methods. This paper describes a new low-cost and nonradioactive industrial field prototype device that provides, continuously and in real time, the vertical profile of the 2-phase liquid within oil field tank separators (i.e., percentage of water in oil at different heights of the tank, as well as the emulsion layer interfaces) using ultrasonic waves. The device, which has been installed in a vessel through an 8-in. flange, consists of a 1-D array of tens of ultrasonic transducers (28 transducers in this paper) that are activated in a time-multiplexed manner by an embedded transmitter fixed on the top of the tank. This latest version implements a feedforward neural network with back-propagation learning to determine the vertical water-cut distribution along the vessel. It also implements an expert-system-based algorithm to determine the lower and higher positions of the emulsion layer. The results obtained from the extensive experiments, which have been conducted under various conditions of temperature, indicate that the device can determine the profile of the 2-phase liquid within a relative error of +/- 3%.

  18. Continuous measurements of suspended sediment loads using dual frequency acoustic Doppler profile signals

    NASA Astrophysics Data System (ADS)

    Antonini, Alessandro; Guerrero, Massimo; Rüther, Nils; Stokseth, Siri

    2016-04-01

    A huge thread to Hydropower plants (HPP) is incoming sediments in suspension from the rivers upstream. The sediments settle in the reservoir and reduce the effective head as well as the volume and reduce consequently the lifetime of the reservoir. In addition are the fine sediments causing severe damages to turbines and infrastructure of a HPP. For estimating the amount of in-coming sediments in suspension and the consequent planning of efficient counter measures, it is essential to monitor the rivers within the catchment of the HPP for suspended sediments. This work is considerably time consuming and requires highly educated personnel and is therefore expensive. Surrogate-indirect methods using acoustic and optic devices have bee developed since the last decades that may be efficiently applied for the continuous monitoring of suspended sediment loads. The presented study proposes therefore to establish a research station at a cross section of a river which is the main tributary to a reservoir of a HPP and equip this station with surrogate as well as with common method of measuring suspended load concentrations and related flow discharge and level. The logger at the research station delivers data automatically to a server. Therefore it is ensured that also large flood events are covered. Data during flood are of high interest to the HPP planners since they carried the most part of the sediment load in a hydrological year. Theses peaks can hardly be measured with common measurement methods. Preliminary results of the wet season 2015/2016 are presented. The data gives insight in the applicable range, in terms of scattering particles concentration-average size and corresponding flow discharge and level, eventually enabling the study of suspended sediment load-water flow correlations during peak events. This work is carried out as part of a larger research project on sustainable hydro power plants exposed to high sediment yield, SediPASS. SediPASS is funded by the

  19. Directivity and Sensitivity of Fiber-Optic Cable Measuring Ground Motion using a Distributed Acoustic Sensing Array

    NASA Astrophysics Data System (ADS)

    Lancelle, C.; Lord, N. E.; Wang, H. F.; Fratta, D.; Nigbor, R. L.; Chalari, A.; Karaulanov, R.; Baldwin, J. A.; Castongia, E.

    2014-12-01

    Distributed acoustic sensing (DAS) is a relatively recent development for measurement of ground motion by using a fiber-optic cable itself as the sensor. In September 2013 a field test was conducted at the NEES@UCSB Garner Valley field site in Southern California incorporating DAS technology. A 762 meter long fiber-optic cable was trenched to a depth of about 0.3 m in a rectangular design with two interior diagonal segments. Existing instruments at the field site include the Garner Valley Downhole Array (GVDA) surface and borehole accelerometers and pore pressure transducers. A PASSCAL seismometer array and four NEES@UCLA tri-axial accelerometers were also deployed along the two interior diagonal segments. These sensors also recorded most of the source events. One goal of the field test was to study the response of the fiber-optic cable to various vibration sources, including a 45 kN shear shaker and a smaller 450 N portable mass shaker, both of which were available through NEES@UCLA. In addition to the shear sources, signals were recorded from a mini-Vibe source and hammer blows on a steel plate. The focus of this study is on the directivity and the sensitivity of the fiber-optic cable and the distributed acoustic sensor. Preliminary results indicate that the fiber-optic cable is most effective if oriented in the direction of maximum strain. Even with the directional response, signals were recorded throughout the array for different cable orientations at distances up to two-hundred meters. Move-out of different phases could be seen over several meters of traces recorded one-meter apart. Sensitivity of the fiber-optic cable relative to the other instruments is also presented.

  20. Comparison of acoustic doppler current profiler and Price AA mechanical current meter measurements made during the 2011 Mississippi River Flood

    USGS Publications Warehouse

    O'Brien, Patrick; Mueller, David; Pratt, Thad

    2012-01-01

    The Mississippi River and Tributaries project performed as designed during the historic 2011 Mississippi River flood, with many of the operational decisions based on discharge targets as opposed to stage. Measurement of discharge at the Tarbert Landing, Mississippi range provides critical information used in operational decisions for the floodways located in Louisiana. Historically, discharge measurements have been made using a Price AA current meter and the mid-section method, and a long record exists based on these types of measurements, including historical peak discharges. Discharge measurements made using an acoustic Doppler current profiler from a moving boat have been incorporated into the record since the mid 1990's, and are used along with the Price AA mid-section measurements. During the 2011 flood event, both methods were used and appeared to provide different results at times. The apparent differences between the measurement techniques are due to complex hydrodynamics at this location that created large spatial and temporal fluctuations in the flow. The data and analysis presented herein show the difference between the two methods to be within the expected accuracy of the measurements when the measurements are made concurrently. The observed fluctuations prevent valid comparisons of data collected sequentially or even with different observation durations.

  1. Validation of exposure time for discharge measurements made with two bottom-tracking acoustic doppler current profilers

    USGS Publications Warehouse

    Czuba, J.A.; Oberg, K.

    2008-01-01

    Previous work by Oberg and Mueller of the U.S. Geological Survey in 2007 concluded that exposure time (total time spent sampling the flow) is a critical factor in reducing measurement uncertainty. In a subsequent paper, Oberg and Mueller validated these conclusions using one set of data to show that the effect of exposure time on the uncertainty of the measured discharge is independent of stream width, depth, and range of boat speeds. Analysis of eight StreamPro acoustic Doppler current profiler (ADCP) measurements indicate that they fall within and show a similar trend to the Rio Grande ADCP data previously reported. Four special validation measurements were made for the purpose of verifying the conclusions of Oberg and Mueller regarding exposure time for Rio Grande and StreamPro ADCPs. Analysis of these measurements confirms that exposure time is a critical factor in reducing measurement uncertainty and is independent of stream width, depth, and range of boat speeds. Furthermore, it appears that the relation between measured discharge uncertainty and exposure time is similar for both Rio Grande and StreamPro ADCPs. These results are applicable to ADCPs that make use of broadband technology using bottom-tracking to obtain the boat velocity. Based on this work, a minimum of two transects should be collected with an exposure time for all transects greater than or equal to 720 seconds in order to achieve an uncertainty of ??5 percent when using bottom-tracking ADCPs. ?? 2008 IEEE.

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

    SciTech Connect

    Kim, Hyun-Sook; Flagg, C.N.; Shi, Yan

    1996-06-01

    Acoustic Doppler current profiler (ADCP) data is part of the core data for the U.S. JGOFS Arabian Sea project, along with hydrographic and nutrient data. Seventeen cruises are scheduled to take place between September 1994 and January 1996 on the R/V T.G. Thompson. They are numbered consecutively from the ship`s commissioning with the first JGOFS cruise designated TN039. Table 1 lists start and end dates of each cruise with its mission. All but the first cruise have been or will be staged from Muscat, Oman. Each cruise is scheduled for a duration of between two weeks and one month. Seven of the cruises, referred to as process cruises, follow a standard cruise track, taking hydrographic, chemical and biological measurements. The rest of the cruises, which take place generally within the standard cruise region defined by a set track, are for the deployment and recovery of moored equipments and towing of a SeaSoar. ADCP data are collected using an autonomous data acquisition system developed for ship-of-opportunity cruises, named the AutoADCP system. The system is an extension of RD instrument`s DAS version 2.48 using enhancements made possible with {open_quotes}user-exit{close_quotes} programs. It makes it possible to collect ADCP data without the constant monitoring usually necessary and insures constant data coverage and uniform data quality.

  3. Shipboard acoustic doppler current profiler data collected during the Western Tropical Atlantic Experiment (WESTRAX) 1991. Technical memo

    SciTech Connect

    Routt, J.A.; Wilson, W.D.

    1992-11-01

    The long-term goal of ongoing and future research in the western tropical Atlantic is to estimate the cross-equatorial transport of water and heat. The overall goals of those involved in the Western Tropical Atlantic Experiment (WESTRAX) are (a) to describe the annual cycle in the large-scale structure of the velocity and hydrographic properties over the full water column in the western tropical Atlantic Ocean between the equator and 15 degrees N, and (b) to compare data and models in order to better understand the physics of the regional circulation in the broader context of Atlantic basin thermohaline circulation. The results of this combined effort will greatly improve our understanding of this complex boundary current region and establish the basis for efficient long-term climatic monitoring of the critical meridional fluxes of mass and heat across the tropical Atlantic. This report presents the Acoustic Doppler Current Profiler (ADCP) data obtained during (ACCP) Atlantic Climate Change Program cruises in the western subtropical and tropical Atlantic in January, June and September 1991.

  4. Advancements in the development of a directional-position sensing fast neutron detector using acoustically tensioned metastable fluids

    NASA Astrophysics Data System (ADS)

    Archambault, Brian C.; Webster, Jeffrey A.; Grimes, Thomas F.; Fischer, Kevin F.; Hagen, Alex R.; Taleyakhan, Rusi P.

    2015-06-01

    Advancements in the development of a direction and position sensing fast neutron detector which utilizes the directional acoustic tensioned metastable fluid detector (D-ATMFD) are described. The resulting D-ATMFD sensor is capable of determining the direction of neutron radiation with a single compact detector versus use of arrays of detectors in conventional directional systems. Directional neutron detection and source positioning offer enhanced detection speeds in comparison to traditional proximity searching; including enabling determination of the neutron source shape, size, and strength in near real time. This paper discusses advancements that provide the accuracy and precision of ascertaining directionality and source localization information utilizing enhanced signal processing-cum-signal analysis, refined computational algorithms, and on-demand enlargement capability of the detector sensitive volume. These advancements were accomplished utilizing experimentation and theoretical modeling. Benchmarking and qualifications studies were successfully conducted with random and fission based special nuclear material (SNM) neutron sources (239Pu-Be and 252Cf). These results of assessments have indicated that the D-ATMFD compares well in technical performance with banks of competing directional fast neutron detector technologies under development worldwide, but it does so with a single detector unit, an unlimited field of view, and at a significant reduction in both cost and size while remaining completely blind to common background (e.g., beta-gamma) radiation. Rapid and direct SNM neutron source imaging with two D-ATMFD sensors was experimentally demonstrated, and furthermore, validated via multidimensional nuclear particle transport simulations utilizing MCNP-PoliMi. Characterization of a scaled D-ATMFD based radiation portal monitor (RPM) as a cost-effective and efficient 3He sensor replacement was performed utilizing MCNP-PoliMi simulations, the results of which

  5. A Study On The Validity Of Buoy Mounted Acoustic Doppler Profilers: A Comparison Of Upward And Downward Looking Systems In Onslow Bay, NC

    DTIC Science & Technology

    2010-06-01

    and therefore corrections applied for pitch and roll might be incorrect. The study showed the two systems did not agree well, but because the...Hence, mounting Acoustic Doppler Current Profilers ( ADCPs ) to these buoys has proven to be an avenue worth exploring. In a previous study done by...Seim and Edwards [1], a downward-looking ADCP from NDBC buoy 41008 was compared to an upward- looking ADCP from the University of North Carolina at

  6. SPECIAL ISSUE DEVOTED TO MULTIPLE RADIATION SCATTERING IN RANDOM MEDIA: Direct opto-acoustic in vitro measurement of the spatial distribution of laser radiation in biological media

    NASA Astrophysics Data System (ADS)

    Pelivanov, Ivan M.; Belov, Sergej A.; Solomatin, Vladimir S.; Khokhlova, Tanya D.; Karabutov, Aleksander A.

    2006-12-01

    The problem of opto-acoustic (AO) diagnostics of light scattering and absorption in biological media is considered. The objects under study were milk, bovine and porcine liver, and bovine muscle tissue. The forward and backward schemes for recording acoustic signals were used in experiments. The spatial distribution of the light intensity was measured for each biological medium from the temporal profile of the excited OA pulse and the absorption coefficient and reduced scattering coefficient were determined. Opto-acoustic signals were excited by a 1064-nm pulsed Nd:YAG laser and a tunable Ti:sapphire laser at 779 nm. It is shown that the proposed method can be used for obtaining a priori information on a biological medium in problems of optical and AO tomography.

  7. Underwater acoustic wave generation by filamentation of terawatt ultrashort laser pulses.

    PubMed

    Jukna, Vytautas; Jarnac, Amélie; Milián, Carles; Brelet, Yohann; Carbonnel, Jérôme; André, Yves-Bernard; Guillermin, Régine; Sessarego, Jean-Pierre; Fattaccioli, Dominique; Mysyrowicz, André; Couairon, Arnaud; Houard, Aurélien

    2016-06-01

    Acoustic signals generated by filamentation of ultrashort terawatt laser pulses in water are characterized experimentally. Measurements reveal a strong influence of input pulse duration on the shape and intensity of the acoustic wave. Numerical simulations of the laser pulse nonlinear propagation and the subsequent water hydrodynamics and acoustic wave generation show that the strong acoustic emission is related to the mechanism of superfilamention in water. The elongated shape of the plasma volume where energy is deposited drives the far-field profile of the acoustic signal, which takes the form of a radially directed pressure wave with a single oscillation and a very broad spectrum.

  8. Surface acoustic wave amplification by direct current-voltage supplied to graphene film

    SciTech Connect

    Insepov, Z.; Emelin, E.; Kononenko, O.; Roshchupkin, D. V.; Tnyshtykbayev, K. B.; Baigarin, K. A.

    2015-01-12

    Using a high-resolution X-Ray diffraction measurement method, the surface acoustic wave (SAW) propagation in a graphene film on the surface of a Ca{sub 3}TaGa{sub 3}Si{sub 2}O{sub 14} (CTGS) piezoelectric crystal was investigated, where an external current was driven across the graphene film. Here, we show that the application of the DC field leads to a significant enhancement of the SAW magnitude and, as a result, to amplification of the diffraction satellites. Amplification of 33.2 dB/cm for the satellite +1, and of 13.8 dB/cm for the satellite +2, at 471 MHz has been observed where the external DC voltage of +10 V was applied. Amplification of SAW occurs above a DC field much smaller than that of a system using bulk semiconductor. Theoretical estimates are in reasonable agreement with our measurements and analysis of experimental data for other materials.

  9. Depression Diagnoses and Fundamental Frequency-Based Acoustic Cues in Maternal Infant-Directed Speech

    PubMed Central

    Porritt, Laura L.; Zinser, Michael C.; Bachorowski, Jo-Anne; Kaplan, Peter S.

    2013-01-01

    F0-based acoustic measures were extracted from a brief, sentence-final target word spoken during structured play interactions between mothers and their 3- to 14-month-old infants, and were analyzed based on demographic variables and DSM-IV Axis-I clinical diagnoses and their common modifiers. F0 range (ΔF0) was negatively correlated with infant age and number of children. ΔF0 was significantly smaller in clinically depressed mothers and mothers diagnosed with depression in partial remission, relative to non-depressed mothers, mothers diagnosed with depression in full remission, and those diagnosed with depressive disorder not otherwise specified. ΔF0 was significantly lower in mothers experiencing their first major depressive episode relative to mothers with recurrent depression. Deficits in ΔF0 were specific to diagnosed clinical depression, and were not well predicted by elevated self-report scores only, or by diagnosed anxiety disorders. Mothers with higher ΔF0 had infants with reportedly larger productive vocabularies, but depression was unrelated to vocabulary development. Implications for cognitive-linguistic development are discussed. PMID:24489521

  10. Gravimetric and density profiling using the combination of surface acoustic waves and neutron reflectivity.

    PubMed

    Toolan, Daniel T W; Barker, Robert; Gough, Tim; Topham, Paul D; Howse, Jonathan R; Glidle, Andrew

    2017-02-01

    A new approach is described herein, where neutron reflectivity measurements that probe changes in the density profile of thin films as they absorb material from the gas phase have been combined with a Love wave based gravimetric assay that measures the mass of absorbed material. This combination of techniques not only determines the spatial distribution of absorbed molecules, but also reveals the amount of void space within the thin film (a quantity that can be difficult to assess using neutron reflectivity measurements alone). The uptake of organic solvent vapours into spun cast films of polystyrene has been used as a model system with a view to this method having the potential for extension to the study of other systems. These could include, for example, humidity sensors, hydrogel swelling, biomolecule adsorption or transformations of electroactive and chemically reactive thin films. This is the first ever demonstration of combined neutron reflectivity and Love wave-based gravimetry and the experimental caveats, limitations and scope of the method are explored and discussed in detail.

  11. Novel applications of motif-directed profiling to identify disease resistance genes in plants.

    PubMed

    Vossen, Jack H; Dezhsetan, Sara; Esselink, Danny; Arens, Marjon; Sanz, Maria J; Verweij, Walter; Verzaux, Estelle; van der Linden, C Gerard

    2013-10-07

    Molecular profiling of gene families is a versatile tool to study diversity between individual genomes in sexual crosses and germplasm. Nucleotide binding site (NBS) profiling, in particular, targets conserved nucleotide binding site-encoding sequences of resistance gene analogs (RGAs), and is widely used to identify molecular markers for disease resistance (R) genes. In this study, we used NBS profiling to identify genome-wide locations of RGA clusters in the genome of potato clone RH. Positions of RGAs in the potato RH and DM genomes that were generated using profiling and genome sequencing, respectively, were compared. Largely overlapping results, but also interesting discrepancies, were found. Due to the clustering of RGAs, several parts of the genome are overexposed while others remain underexposed using NBS profiling. It is shown how the profiling of other gene families, i.e. protein kinases and different protein domain-coding sequences (i.e., TIR), can be used to achieve a better marker distribution. The power of profiling techniques is further illustrated using RGA cluster-directed profiling in a population of Solanum berthaultii. Multiple different paralogous RGAs within the Rpi-ber cluster could be genetically distinguished. Finally, an adaptation of the profiling protocol was made that allowed the parallel sequencing of profiling fragments using next generation sequencing. The types of RGAs that were tagged in this next-generation profiling approach largely overlapped with classical gel-based profiling. As a potential application of next-generation profiling, we showed how the R gene family associated with late blight resistance in the SH*RH population could be identified using a bulked segregant approach. In this study, we provide a comprehensive overview of previously described and novel profiling primers and their genomic targets in potato through genetic mapping and comparative genomics. Furthermore, it is shown how genome-wide or fine mapping can be

  12. Novel applications of motif-directed profiling to identify disease resistance genes in plants

    PubMed Central

    2013-01-01

    Background Molecular profiling of gene families is a versatile tool to study diversity between individual genomes in sexual crosses and germplasm. Nucleotide binding site (NBS) profiling, in particular, targets conserved nucleotide binding site-encoding sequences of resistance gene analogs (RGAs), and is widely used to identify molecular markers for disease resistance (R) genes. Results In this study, we used NBS profiling to identify genome-wide locations of RGA clusters in the genome of potato clone RH. Positions of RGAs in the potato RH and DM genomes that were generated using profiling and genome sequencing, respectively, were compared. Largely overlapping results, but also interesting discrepancies, were found. Due to the clustering of RGAs, several parts of the genome are overexposed while others remain underexposed using NBS profiling. It is shown how the profiling of other gene families, i.e. protein kinases and different protein domain-coding sequences (i.e., TIR), can be used to achieve a better marker distribution. The power of profiling techniques is further illustrated using RGA cluster-directed profiling in a population of Solanum berthaultii. Multiple different paralogous RGAs within the Rpi-ber cluster could be genetically distinguished. Finally, an adaptation of the profiling protocol was made that allowed the parallel sequencing of profiling fragments using next generation sequencing. The types of RGAs that were tagged in this next-generation profiling approach largely overlapped with classical gel-based profiling. As a potential application of next-generation profiling, we showed how the R gene family associated with late blight resistance in the SH*RH population could be identified using a bulked segregant approach. Conclusions In this study, we provide a comprehensive overview of previously described and novel profiling primers and their genomic targets in potato through genetic mapping and comparative genomics. Furthermore, it is shown how

  13. Toward a Micro-Scale Acoustic Direction-Finding Sensor with Integrated Electronic Readout

    DTIC Science & Technology

    2013-06-01

    1998. [4] A. C. Mason , M. L. Oshinsky, and R. R. Hoy, “Hyperacute directional hearing in a mi- croscale auditory system,” Nature, vol. 410, pp. 686...mechanical (MEMS) sound sensor,” Master’s thesis, Naval Postgraduate School, 2012. [35] J. D. Roth , “Integration of a high sensitivity MEMS directional

  14. Comment on "The directionality of acoustic T-phase signals from small magnitude submarine earthquakes" [J. Acoust. Soc. Am. 119, 3669-3675 (2006)].

    PubMed

    Bohnenstiehl, Delwayne R

    2007-03-01

    In a recent paper, Chapman and Marrett [J. Acoust. Soc. Am. 119, 3669-3675 (2006)] examined the tertiary (T-) waves associated with three subduction-related earthquakes within the South Fiji Basin. In that paper it is argued that acoustic energy is radiated into the sound channel by downslope propagation along abyssal seamounts and ridges that lie distant to the epicenter. A reexamination of the travel-time constraints indicates that this interpretation is not well supported. Rather, the propagation model that is described would require the high-amplitude T-wave components to be sourced well to the east of the region identified, along a relatively flat-lying seafloor.

  15. A direct method for measuring acoustic ground impedance in long-range propagation experiments.

    PubMed

    Soh, Jin H; Gilbert, Kenneth E; Frazier, W M Garth; Talmadge, Carrick L; Waxler, Roger

    2010-11-01

    A method is reported for determining ground impedance in long-range propagation experiments by using the definition of impedance directly. The method is envisioned as way of measuring the impedence at multiple locations along the propagation path, using the signals broadcast during the experiment itself. In a short-range (10 m) test, the direct method was in good agreement with a more conventional model-based least-squares method. The utility of the direct method was demonstrated in a 400 m propagation experiment in a agricultural field. The resulting impedance was consistent with the impedance measured previously in the same field.

  16. Performance assessment of bi-directional knotless tissue-closure devices in juvenile Chinook salmon surgically implanted with acoustic transmitters

    SciTech Connect

    Woodley, Christa M.; Wagner, Katie A.; Bryson, Amanda J.; Eppard, Matthew B.

    2013-07-02

    Acoustic transmitters used in survival and telemetry studies are often surgically implanted in fish. While this is a well-established method, it has the potential to affect health, behavior, and survival, thus affecting study results. Much research has been done to try to minimize the harmful effects caused by the transmitter and tagging process. In 2009, we first investigated the use of a bi-directional knotless (barbed) suture material in juvenile Chinook salmon (Oncorhynchus tshawytscha). We found that it resulted in higher tag retention than the simple interrupted suture pattern; however, the occurrence of ulceration and redness increased. The objective of this study was to refine the suturing patterns of the bi-directional knotless suture and retest suture performance in juvenile Chinook salmon. We tested the bi-directional suture using 3 different suture patterns and two needle types: 6-Point (12-mm needle circumference), Wide “N” (12-mm needle circumference), Wide “N” Knot 12 (12-mm needle circumference), and Wide “N” Knot 18 (18-mm needle circumference).

  17. Indication of direct acoustical cochlea stimulation in comparison to cochlear implants.

    PubMed

    Kludt, Eugen; Büchner, Andreas; Schwab, Burkard; Lenarz, Thomas; Maier, Hannes

    2016-10-01

    The new implantable hearing system Codacs™ was designed to close the treatment gap between active middle ear implants and cochlear implants in cases of severe-to-profound mixed hearing loss. The Codacs™ actuator is attached to conventional stapes prosthesis during the implantation and thereby provides acoustical stimulation through a stapedotomy to the cochlea. Cochlear implants (CIs) on the other hand are an established treatment option for profoundly deaf patients including mixed hearing losses that are possible candidates for the Codacs™. In this retrospective study, we compared the clinical outcome of 25 patients with the Codacs™ (≥3 month post-activation) to 54 CI patients (two years post-activation) with comparable pre-operative bone conduction (BC) thresholds that were potential candidates for both categories of devices. The word recognition score (Freiburg monosyllables test) in quiet was significantly (p < 0.05) better in the Codacs™ than in the corresponding CI patients for average pre-operative bone conduction below 60 dB HL and equal in patients with a pre-operative BC PTA between 60 and 70 dB HL. Speech in noise intelligibility (HSM sentences test at +10 dB SNR) was significantly (p < 0.001) better in Codacs™ (80% median) than in CI patients (25% median) in all tested groups. Our results indicate for patients with sufficient cochlear reserve that speech intelligibility in noise with the Codacs™ hearing implant is significantly better than with a CI. Further, results in Codacs™ were better predictable, encouraging the extension of the indication to patients with less cochlear reserve than reported here.

  18. Using a fibre-optic cable as Distributed Acoustic Sensor for Vertical Seismic Profiling - Overview of various field tests

    NASA Astrophysics Data System (ADS)

    Götz, Julia; Lüth, Stefan; Henninges, Jan; Reinsch, Thomas

    2015-04-01

    Fibre-optic Distributed Acoustic Sensing (DAS) or Distributed Vibration Sensing (DVS) is a technology, where an optical fibre cable is used as a sensor for acoustic signals. An ambient seismic wavefield, which is coupled by friction or pressure to the optical fibre, induces dynamic strain changes along the cable. The DAS/DVS technology offers the possibility to record an optoelectronic signal which is linearly related to the time dependent local strain. The DAS/DVS technology is based on the established technique of phase-sensitive optical time-domain reflectometry (phi-OTDR). Coherent laser pulses are launched into the fibre to monitor changes in the resulting elastic Rayleigh backscatter with time. Dynamic strain changes lead to small displacements of the scattering elements (non-uniformities within the glass structure of the optical fibre), and therefore to variations of the relative phases of the backscattered photons. The fibre behaves as a series of interferometers whose output is sensitive to small changes of the strain at any point along its length. To record the ground motion not only in space but also in time, snapshots of the wavefield are created by repeatedly firing laser pulses into the fibre at sampling frequencies much higher than seismic frequencies. DAS/DVS is used e.g. for continuous monitoring of pipelines, roads or borders and for production monitoring from within the wellbore. Within the last years, the DAS/DVS technology was further developed to record seismic data. We focus on the recording of Vertical Seismic Profiling (VSP) data with DAS/DVS and present an overview of various field tests published between 2011 and 2014. Here, especially CO2 storage pilot sites provided the opportunity to test this new technology for geophysical reservoir monitoring. DAS/DVS-VSP time-lapse measurements have been published for the Quest CO2 storage site in Canada. The DAS/DVS technology was also tested at the CO2 storage sites in Rousse (France), Citronelle

  19. Direct evidence for anisotropic He diffusivity in zircon provided by laser depth profiling (Invited)

    NASA Astrophysics Data System (ADS)

    Hodges, K.; van Soest, M. C.; Monteleone, B. D.; Boyce, J. W.

    2009-12-01

    While zircon (U-Th)/He dating has become an increasingly popular tool for studies of the thermal evolution of orogenic systems, several issues complicate interpretations of the geologic significance of zircon “dates”. Zircons frequently exhibit complex U-Th zoning, which makes corrections for alpha ejection loss uncertain. It has been known for decades that radiation damage enhances the rate of diffusive loss of helium in zircon, sometimes making the unique assignment of a (U-Th)/He closure temperature difficult. Here we consider another complicating factor: the proposal by Reich et al. (2007) - based on computer simulations - that He diffusion is anisotropic in zircon, which also may have significant implications regarding (U-Th)/He closure temperature. We present, for the first time, direct measurements of crystallographically controlled, anisotropic diffusion profiles in zircon that appear to support the conclusions of Reich et al. (2007). For this study, we conducted replicate vacuum heating experiments on slices from euhedral crystals of Cretaceous De Beers zircon from South Africa and Proterozoic Mud Tank zircon from Australia. (All slices were cut from the central portions of very large crystals in order to avoid natural alpha ejection profiles near crystal margins.) In each experiment, we heated slices of the two zircons cut both parallel and perpendicular to their c-axes for 24 hours at 415° C. Depth profiling of the resulting 4He diffusion profiles using an ArF excimer laser revealed extremely similar c-axis parallel diffusion profiles for both zircons, and extremely similar c-axis perpendicular diffusion profiles for both zircons. However, the c-axis parallel and perpendicular profiles were markedly different. The loss profiles parallel to c extended over twice as far into the crystals as did the perpendicular profiles, implying much more rapid thermally activated diffusion parallel to the c direction, as predicted by the Reich et al. models

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

    SciTech Connect

    Flagg, C.N.; Shi, Y.

    1995-04-01

    Acoustic Doppler Current Profiler (ADCP) data from the R/V T.G. THOMPSON is part of the core data for the US JGOFS Arabian Sea project along with hydrographic and nutrient data. Seventeen cruises on the THOMPSON are scheduled to take place between September 1994 and January 1996. The first of these cruises, a transit of the R/V THOMPSON into the northern Arabian Sea area from Singapore, was a calibration and training cruise that took place between September 18 and October 7, 1994. (The cruises on the THOMPSON are numbered consecutively from the ship`s commissioning with the first JOGFS cruise designated TN039.) The remaining cruises have been and will be staged from Muscat, Oman. Seven of these cruises, referred to as process cruises, will follow a set cruise track, making hydrographic, chemical and biological measurements. The remainder of the cruises while not restricted to the set cruise track, will generally stay within the region defined by the track during the deployment and retrieval of moored equipment and the towing of a SeaSoar. Each cruise will last between two weeks and one month. ADCP data will be collected on all the JGOFS Arabian Sea cruises using an autonomous data acquisition system developed for ship-of-opportunity cruises. This system, referred to as the AutoADCP, makes it possible to collect the ADCP data without the constant monitoring usually necessary and assures constant data coverage and uniform data quality. The AutoADCP system is an extension of RD Instrument`s DAS version 2.48 using enhancements made possible with ``user exit`` programs. This data report presents ADCP results from the first four JGOFS cruises, TN039 through TN042, concentrating on the data collection and processing methods.

  1. Acoustic Doppler current profiler raw measurements on the Missouri and Yellowstone rivers, 2000-2016, Columbia Environmental Research Center

    USGS Publications Warehouse

    Bulliner, Edward A.; Elliott, Caroline M.; Jacobson, Robert B.

    2017-01-01

    Between the years 2000 and 2016, scientists and technicians from the U.S. Geological Survey (USGS) Columbia Environmental Research Center (CERC) have collected over 400 field-days worth of acoustic Doppler current profiler (ADCP) measurements on the Missouri and Yellowstone Rivers, primarily for the purposes of assessing physical aquatic habitat for the pallid sturgeon. Scientists and technicians collected data using boat-mounted Teledyne Rio Grande ADCPs, which were processed using customized scripting tools and archived in standardized formats. To assess longitudinal variability in depth and velocity distributions along the Missouri River, as well as compare the Missouri River to its unaltered analog, the Yellowstone River, we compiled the collected datasets into a single comma-separated value (csv) file using a series of data-processing scripts written in Python. To allow for the comparison of measurements collected only within a specific window of flow exceedance, we conducted geospatial analyses to attribute each ADCP measurement by a discharge from the most relevant USGS gage location (with the most relevant gage location being the gage located between the same major tributaries as the measurement, even if it was not the closest spatially), and assigned each measurement a flow exceedance percentile based on the relevant gage's record between 2000 and 2016. We also conducted general quality control on the data, discarding any ADCP returns where the ADCP measured a depth-averaged velocity greater than 3 meters per second or a depth greater than 16 meters; these values were considered to be an approximate upper bounds for realistic values on the Missouri and Yellowstone Rivers. The presented csv file lists individual ADCP bins for all measurements that have been archived between 2000 and 2016 by CERC scientists along with their three-dimensional velocity components, depth-averaged velocity magnitude for a given ADCP return, average channel depth for a given ADCP

  2. Correlation of the Iranian Voice Quality of Life Profile (IVQLP) with Acoustic Measurements across Three Common Voice Disorders.

    PubMed

    Dehqan, Ali; Scherer, Ronald C; Yadegari, Fariba; Dashti, Gholamali

    2017-09-28

    The Iranian Voice Quality of Life Profile (IVQLP) is a recent culture-based developed tool for assessing the quality of life of dysphonic patients. The research questions addressed here are as follows: (1) Are the correlations between IVQLP scores and values of objective voice measures? (2) Do the correlations differ across the three different voice disorders? The subjects were divided into three groups: muscle tension dysphonia (MTD) (n = 62), benign midmembranous vocal fold lesions (n = 56), and unilateral vocal fold paralysis (UVFP) (n = 32). The study sample consisted of 91 males and 59 females. The individuals had a mean age of 46.53 ± 13.84 years. All of the participants completed the IVQLP questionnaire. The PRAAT software was used to provide acoustic analyses. The correlations between fundamental frequency (F0), perturbation analyses, harmonics-to-noise ratio, and IVQLP data of the three groups of patients were measured using Pearson's correlation. There was a significant correlation between the total score and jitter in the MTD group. For the benign vocal fold lesion group, correlations were significant and relatively strong for numerous analyses. Again, there were numerous significant and strong correlations for the UVFP group. Results may indicate two interpretations. One interpretation of the results is that patients with morphological tissue changes (lesions, paralysis) appear to associate their sense of how their voice problem negatively affects their lives. A second interpretation is that there is perhaps a threshold of vocal perturbation or instability that lends itself to a patient's connection to his or her sense of how the voice affects his or her quality of life. Copyright © 2017 The Voice Foundation. All rights reserved.

  3. Quantifying acoustic doppler current profiler discharge uncertainty: A Monte Carlo based tool for moving-boat measurements

    USGS Publications Warehouse

    Mueller, David S.

    2017-01-01

    This paper presents a method using Monte Carlo simulations for assessing uncertainty of moving-boat acoustic Doppler current profiler (ADCP) discharge measurements using a software tool known as QUant, which was developed for this purpose. Analysis was performed on 10 data sets from four Water Survey of Canada gauging stations in order to evaluate the relative contribution of a range of error sources to the total estimated uncertainty. The factors that differed among data sets included the fraction of unmeasured discharge relative to the total discharge, flow nonuniformity, and operator decisions about instrument programming and measurement cross section. As anticipated, it was found that the estimated uncertainty is dominated by uncertainty of the discharge in the unmeasured areas, highlighting the importance of appropriate selection of the site, the instrument, and the user inputs required to estimate the unmeasured discharge. The main contributor to uncertainty was invalid data, but spatial inhomogeneity in water velocity and bottom-track velocity also contributed, as did variation in the edge velocity, uncertainty in the edge distances, edge coefficients, and the top and bottom extrapolation methods. To a lesser extent, spatial inhomogeneity in the bottom depth also contributed to the total uncertainty, as did uncertainty in the ADCP draft at shallow sites. The estimated uncertainties from QUant can be used to assess the adequacy of standard operating procedures. They also provide quantitative feedback to the ADCP operators about the quality of their measurements, indicating which parameters are contributing most to uncertainty, and perhaps even highlighting ways in which uncertainty can be reduced. Additionally, QUant can be used to account for self-dependent error sources such as heading errors, which are a function of heading. The results demonstrate the importance of a Monte Carlo method tool such as QUant for quantifying random and bias errors when

  4. Comparison of bottom-track to global positioning system referenced discharges measured using an acoustic Doppler current profiler

    USGS Publications Warehouse

    Wagner, C.R.; Mueller, D.S.

    2011-01-01

    A negative bias in discharge measurements made with an acoustic Doppler current profiler (ADCP) can be caused by the movement of sediment on or near the streambed. The integration of a global positioning system (GPS) to track the movement of the ADCP can be used to avoid the systematic negative bias associated with a moving streambed. More than 500 discharge transects from 63 discharge measurements with GPS data were collected at sites throughout the US, Canada, and New Zealand with no moving bed to compare GPS and bottom-track-referenced discharges. Although the data indicated some statistical bias depending on site conditions and type of GPS data used, these biases were typically about 0.5% or less. An assessment of differential correction sources was limited by a lack of data collected in a range of different correction sources and different GPS receivers at the same sites. Despite this limitation, the data indicate that the use of Wide Area Augmentation System (WAAS) corrected positional data is acceptable for discharge measurements using GGA as the boat-velocity reference. The discharge data based on GPS-referenced boat velocities from the VTG data string, which does not require differential correction, were comparable to the discharges based on GPS-referenced boat velocities from the differentially-corrected GGA data string. Spatial variability of measure discharges referenced to GGA, VTG and bottom-tracking is higher near the channel banks. The spatial variability of VTG-referenced discharges is correlated with the spatial distribution of maximum Horizontal Dilution of Precision (HDOP) values and the spatial variability of GGA-referenced discharges is correlated with proximity to channel banks. ?? 2011 Published by Elsevier B.V.

  5. Comparison of bottom-track to global positioning system referenced discharges measured using an acoustic Doppler current profiler

    NASA Astrophysics Data System (ADS)

    Wagner, Chad R.; Mueller, David S.

    2011-05-01

    SummaryA negative bias in discharge measurements made with an acoustic Doppler current profiler (ADCP) can be caused by the movement of sediment on or near the streambed. The integration of a global positioning system (GPS) to track the movement of the ADCP can be used to avoid the systematic negative bias associated with a moving streambed. More than 500 discharge transects from 63 discharge measurements with GPS data were collected at sites throughout the US, Canada, and New Zealand with no moving bed to compare GPS and bottom-track-referenced discharges. Although the data indicated some statistical bias depending on site conditions and type of GPS data used, these biases were typically about 0.5% or less. An assessment of differential correction sources was limited by a lack of data collected in a range of different correction sources and different GPS receivers at the same sites. Despite this limitation, the data indicate that the use of Wide Area Augmentation System (WAAS) corrected positional data is acceptable for discharge measurements using GGA as the boat-velocity reference. The discharge data based on GPS-referenced boat velocities from the VTG data string, which does not require differential correction, were comparable to the discharges based on GPS-referenced boat velocities from the differentially-corrected GGA data string. Spatial variability of measure discharges referenced to GGA, VTG and bottom-tracking is higher near the channel banks. The spatial variability of VTG-referenced discharges is correlated with the spatial distribution of maximum Horizontal Dilution of Precision (HDOP) values and the spatial variability of GGA-referenced discharges is correlated with proximity to channel banks.

  6. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor; Hearing loss - acoustic; Tinnitus - acoustic ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  7. Development of a low profile acoustical door for use on racks and cabinets for the information technology industry

    NASA Astrophysics Data System (ADS)

    O'Connell, Michael D.; Anderl, William James

    2005-09-01

    This paper presents the design of 19 inch rack acoustical doors balancing acoustical attenuation, airflow impedance and distribution in a short depth by combining air foil technology with acoustic baffle design. Design optimization was done utilizing fluid flow analytical modeling and verified with a air flow bench and an acoustical rack door test fixture. Higher heat loads in rack mounted computer equipment drive higher cooling requirements. In order to provide air cooling solutions, higher volumetric air flow is required resulting in higher acoustical noise levels. These noise levels can result in noise levels that are unacceptable to the customer. Acoustical doors lower noise levels but are prone to high flow impedance, uneven flow distribution and large physical depth. High impedances require higher air moving device speeds to offset the lost volumetric air flow. This decreases the effective acoustical attenuation. Various rack modules have different inlet and outlet air flow locations making the distribution of the air from the door (front) or into the door(rear) important. Solutions to these problems usually require large depths in order to provide blockage of line of site and gradual air flow lines to keep impedance low and provide even distribution of the air.

  8. Correcting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River

    USGS Publications Warehouse

    Gartner, J.W.; Ganju, N.K.

    2007-01-01

    Discharge measurements were made by acoustic Doppler current profiler at two locations on the Colorado River during the 2004 controlled flood from Glen Canyon Dam, Arizona. Measurement hardware and software have constantly improved from the 1980s such that discharge measurements by acoustic profiling instruments are now routinely made over a wide range of hydrologic conditions. However, measurements made with instruments deployed from moving boats require reliable boat velocity data for accurate measurements of discharge. This is normally accomplished by using special acoustic bottom track pings that sense instrument motion over bottom. While this method is suitable for most conditions, high current flows that produce downstream bed sediment movement create a condition known as moving bed that will bias velocities and discharge to lower than actual values. When this situation exists, one solution is to determine boat velocity with satellite positioning information. Another solution is to use a lower frequency instrument. Discharge measurements made during the 2004 Glen Canyon controlled flood were subject to moving-bed conditions and frequent loss of bottom track. Due to site conditions and equipment availability, the measurements were conducted without benefit of external positioning information or lower frequency instruments. This paper documents and evaluates several techniques used to correct the resulting underestimated discharge measurements. One technique produces discharge values in good agreement with estimates from numerical model and measured hydrographs during the flood. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

  9. Demonstration of a directional sonic prism in two dimensions using an air-acoustic leaky wave antenna

    SciTech Connect

    Naify, Christina J. Rohde, Charles A.; Calvo, David C.; Orris, Gregory J.; Guild, Matthew D.

    2015-09-28

    Analysis and experimental demonstration of a two-dimensional acoustic leaky wave antenna is presented for use in air. The antenna is comprised of a two-dimensional waveguide patterned with radiating acoustic shunts. When excited using a single acoustic source within the waveguide, the antenna acts as a sonic prism that exhibits frequency steering. This design allows for control of acoustic steering angle using only a single source transducer and a patterned aperture. Aperture design was determined using transmission line analysis and finite element methods. The designed antenna was fabricated and the steering angle measured. The performance of the measured aperture was within 9% of predicted angle magnitudes over all examined frequencies.

  10. Beamforming for directional sources: additional estimator and evaluation of performance under different acoustic scenarios.

    PubMed

    Bouchard, Christian; Havelock, David I; Bouchard, Martin

    2011-04-01

    Beamforming is done with an array of sensors to achieve a directional or spatially-specific response by using a model of the arriving wavefront. Conventionally, a plane wave or point source model is used and this can cause decreased array gain or even total breakdown of beamforming when the source is directional. To avoid this, the authors proposed in recent work an alternative beamforming method which defines a set of "sub-beamformers," each designed to respond to a different spatial mode of the source. The outputs of the individual sub-beamformers are combined in a weighted sum to give an overall output of better quality than that of a monopole beamformer. This paper extends the previous work by introducing an additional estimator for the weighted sum and by presenting simulation results to demonstrate the relative performance of the proposed method and the different estimators for a directional source in the presence of diffuse noise, reverberation, and an interfering source. Gain optimization subject to a constraint on the white-noise gain with the proposed beamforming method is also introduced. Generally, when beamforming on directional sources, the proposed method outperforms beamforming with a point source model when the input signal-to-noise ratio (SNR) is 0 dB or higher.

  11. Sub-seafloor acoustic characterization of seamounts near the Ogasawara Fracture Zone in the western Pacific using chirp (3-7 kHz) subbottom profiles

    USGS Publications Warehouse

    Lee, T.-G.; Hein, J.R.; Lee, Kenneth; Moon, J.-W.; Ko, Y.-T.

    2005-01-01

    A detailed analysis of chirp (3-7 kHz) subbottom profiles and bathymetry was performed on data collected from seamounts near the Ogasawara Fracture Zone (OFZ) in the western Pacific. The OFZ, which is a 150 km wide rift zone showing 600 km of right-lateral movement in a NW-SE direction, is unique among the fracture zones of the Pacific in that it includes many old seamounts (e.g., Magellan Seamounts and seamounts on Dutton Ridge). Sub-seafloor acoustic echoes on the seamounts are classified into nine specific types based on the nature and continuity of the echoes, subbottom structure, and morphology of the seafloor: (1) distinct echoes (types I-1, I-2, I-3), (2) indistinct echoes (types II-1, II-2, II-3), and (3) hyperbolic echoes (types III-1, III-2, III-3). Type I-2 pelagic sediments, characterized by thin and intermittent coverage, were probably deposited in topographically sheltered areas when bottom currents were strong, whereas type I-1 pelagic sediments accumulated during continuous and widespread sedimentation. Development of seamount flank rift zones in the OFZ may have been influenced by preexisting structures in the transform fracture zone at the time of volcanism, whereas those on Ita Mai Tai seamount in the Pigafetta Basin originated solely by edifice-building processes. Flank rift zones that formed by dike intrusions and eruptions played an important role in mass wasting. Mass-wasting processes included block faulting or block slides around the summit margin, sliding/slumping, debris flows, and turbidites, which may have been triggered by faulting, volcanism, dike injection, and weathering during various stages in the evolution of the seamounts. ?? 2005 Elsevier Ltd. All rights reserved.

  12. Predicting absorption and dispersion in acoustics by direct simulation Monte Carlo: Quantum and classical models for molecular relaxation.

    PubMed

    Hanford, Amanda D; O'Connor, Patrick D; Anderson, James B; Long, Lyle N

    2008-06-01

    In the current study, real gas effects in the propagation of sound waves are simulated using the direct simulation Monte Carlo method for a wide range of frequencies. This particle method allows for treatment of acoustic phenomena at high Knudsen numbers, corresponding to low densities and a high ratio of the molecular mean free path to wavelength. Different methods to model the internal degrees of freedom of diatomic molecules and the exchange of translational, rotational and vibrational energies in collisions are employed in the current simulations of a diatomic gas. One of these methods is the fully classical rigid-rotor/harmonic-oscillator model for rotation and vibration. A second method takes into account the discrete quantum energy levels for vibration with the closely spaced rotational levels classically treated. This method gives a more realistic representation of the internal structure of diatomic and polyatomic molecules. Applications of these methods are investigated in diatomic nitrogen gas in order to study the propagation of sound and its attenuation and dispersion along with their dependence on temperature. With the direct simulation method, significant deviations from continuum predictions are also observed for high Knudsen number flows.

  13. Bathymetric surveys of Morse and Geist Reservoirs in central Indiana made with acoustic Doppler current profiler and global positioning system technology, 1996

    USGS Publications Warehouse

    Wilson, J.T.; Morlock, S.E.; Baker, N.T.

    1997-01-01

    Acoustic Doppler current profiler, global positioning system, and geographic information system technology were used to map the bathymetry of Morse and Geist Reservoirs, two artificial lakes used for public water supply in central Indiana. The project was a pilot study to evaluate the use of the technologies for bathymetric surveys. Bathymetric surveys were last conducted in 1978 on Morse Reservoir and in 1980 on Geist Reservoir; those surveys were done with conventional methods using networks of fathometer transects. The 1996 bathymetric surveys produced updated estimates of reservoir volumes that will serve as base-line data for future estimates of storage capacity and sedimentation rates.An acoustic Doppler current profiler and global positioning system receiver were used to collect water-depth and position data from April 1996 through October 1996. All water-depth and position data were imported to a geographic information system to create a data base. The geographic information system then was used to generate water-depth contour maps and to compute the volumes for each reservoir.The computed volume of Morse Reservoir was 22,820 acre-feet (7.44 billion gallons), with a surface area of 1,484 acres. The computed volume of Geist Reservoir was 19,280 acre-feet (6.29 billion gallons), with a surface area of 1,848 acres. The computed 1996 reservoir volumes are less than the design volumes and indicate that sedimentation has occurred in both reservoirs. Cross sections were constructed from the computer-generated surfaces for 1996 and compared to the fathometer profiles from the 1978 and 1980 surveys; analysis of these cross sections also indicates that some sedimentation has occurred in both reservoirs.The acoustic Doppler current profiler, global positioning system, and geographic information system technologies described in this report produced bathymetric maps and volume estimates more efficiently and with comparable or greater resolution than conventional

  14. Profiling Social, Emotional and Behavioural Difficulties of Children Involved in Direct and Indirect Bullying Behaviours

    ERIC Educational Resources Information Center

    Smith, H.; Polenik, K.; Nakasita, S.; Jones, A. P.

    2012-01-01

    Being involved in bullying places a child at risk of poor psychosocial and educational outcomes. This study aimed to examine the profile of behavioural, emotional and social functioning for two subtypes of bullying: direct and indirect (relational). Pupils aged between 7 and 11 years completed sociometric measures of social inclusion and bullying…

  15. Profiles of foreign direct investment in U.S. energy 1993

    SciTech Connect

    1995-05-05

    Profiles of Foreign Direct Investment in US Energy 1993 describes the role of foreign ownership in US energy resources. This report also looks at the investment patterns of US energy companies in other countries. The data used in this report come from the Energy Information Administration (EIA), the US Department of Commerce, company annual reports, and public disclosures of investment activities.

  16. Profiling Social, Emotional and Behavioural Difficulties of Children Involved in Direct and Indirect Bullying Behaviours

    ERIC Educational Resources Information Center

    Smith, H.; Polenik, K.; Nakasita, S.; Jones, A. P.

    2012-01-01

    Being involved in bullying places a child at risk of poor psychosocial and educational outcomes. This study aimed to examine the profile of behavioural, emotional and social functioning for two subtypes of bullying: direct and indirect (relational). Pupils aged between 7 and 11 years completed sociometric measures of social inclusion and bullying…

  17. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

    PubMed

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

    2014-11-24

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell's law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  18. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface

    NASA Astrophysics Data System (ADS)

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-11-01

    Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell’s law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

  19. Nuclear Quadrupole Resonance (NQR) Method and Probe for Generating RF Magnetic Fields in Different Directions to Distinguish NQR from Acoustic Ringing Induced in a Sample

    DTIC Science & Technology

    1997-08-01

    77,719 TITLE OF THE INVENTION NUCLEAR QUADRUPOLE RESONANCE ( NQR ) METHOD AND PROBE FOR GENERATING RF MAGNETIC FIELDS IN DIFFERENT DIRECTIONS TO...DISTINGUISH NQR FROM ACOUSTIC RINGING INDUCED IN A SAMPLE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a...nuclear quadrupole 15 resonance ( NQR ) method and probe for generating RF magnetic fields in different directions towards a sample. More specifically

  20. Directional Compton profiles, valence orbital momentum distributions and B(r) functions for the silane molecule

    NASA Astrophysics Data System (ADS)

    Neerja; Tripathi, A. N.; Smith, Vedene H., Jr.

    2001-04-01

    Isotropic and directional Compton profiles, momentum densities and various momentum expectation values of the SiH4 molecule have been evaluated for several wavefunctions at different levels of correlation. Directional components for several directions relevant to the molecular structure of SiH4 using configuration-interaction wavefunctions are also obtained. Spherically averaged momentum distributions and B(r) functions for the valence orbitals of SiH4 are also calculated and compared with the measured values obtained from electron momentum spectroscopy.

  1. Physically based method for measuring suspended-sediment concentration and grain size using multi-frequency arrays of acoustic-doppler profilers

    USGS Publications Warehouse

    Topping, David J.; Wright, Scott A.; Griffiths, Ronald; Dean, David

    2014-01-01

    As the result of a 12-year program of sediment-transport research and field testing on the Colorado River (6 stations in UT and AZ), Yampa River (2 stations in CO), Little Snake River (1 station in CO), Green River (1 station in CO and 2 stations in UT), and Rio Grande (2 stations in TX), we have developed a physically based method for measuring suspended-sediment concentration and grain size at 15-minute intervals using multifrequency arrays of acoustic-Doppler profilers. This multi-frequency method is able to achieve much higher accuracies than single-frequency acoustic methods because it allows removal of the influence of changes in grain size on acoustic backscatter. The method proceeds as follows. (1) Acoustic attenuation at each frequency is related to the concentration of silt and clay with a known grain-size distribution in a river cross section using physical samples and theory. (2) The combination of acoustic backscatter and attenuation at each frequency is uniquely related to the concentration of sand (with a known reference grain-size distribution) and the concentration of silt and clay (with a known reference grain-size distribution) in a river cross section using physical samples and theory. (3) Comparison of the suspended-sand concentrations measured at each frequency using this approach then allows theory-based calculation of the median grain size of the suspended sand and final correction of the suspended-sand concentration to compensate for the influence of changing grain size on backscatter. Although this method of measuring suspended-sediment concentration is somewhat less accurate than using conventional samplers in either the EDI or EWI methods, it is much more accurate than estimating suspended-sediment concentrations using calibrated pump measurements or single-frequency acoustics. Though the EDI and EWI methods provide the most accurate measurements of suspended-sediment concentration, these measurements are labor-intensive, expensive, and

  2. Direct and quantitative comparison of pixelated density profiles to high resolution X-ray reflectivity data.

    SciTech Connect

    Fenter, Paul; Lee, S. S.; Skelton, A A; Cummings, Peter T

    2011-01-01

    A method for comparing pixelated density profiles (e.g. obtained from molecular dynamics or other computational techniques) with experimental X-ray reflectivity data both directly and quantitatively is described. The conditions under which such a comparison can be made quantitatively (e.g. with errors <1%) are determined theoretically by comparing calculated structure factors for an intrinsic continuous density profile with those obtained from density profiles that have been binned into regular spatial increments. The accuracy of the X-ray reflectivity calculations for binned density profiles is defined in terms of the inter-relationships between resolution of the X-ray reflectivity data (i.e. its range in momentum transfer), the chosen bin size and the width of the intrinsic density profile. These factors play a similar role in the application of any structure-factor calculations that involve the use of pixelated density profiles, such as those obtained from iterative phasing algorithms for inverting structures from X-ray reflectivity and coherent diffraction imaging data. Finally, it is shown how simulations of a quartz water interface can be embedded into an exact description of the bulk phases (including the substrate crystal and the fluid water, below and above the actual interface) to quantitatively reproduce the experimental reflectivity data of a solid liquid interface.

  3. Wind Profiles Obtained with a Molecular Direct Detection Doppler Lidar During IHOP-2002

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce M.; Chen, Huai-Lin; Li, Steven X.; Mathur, Savyasachee; Dobler, Jeremy; Hasselbrack, William; Comer, Joseph

    2004-01-01

    The Goddard Lidar Observatory for Winds (GLOW) is a mobile direct detection Doppler lidar system which uses the double edge technique to measure the Doppler shift of the molecular backscattered laser signal at a wavelength of 355 nm. In the spring of 2002 GLOW was deployed to the western Oklahoma profiling site (36 deg 33.500 min. N, 100 deg. 36.371 min. W) to participate in the International H2O Project (IHOP). During the IHOP campaign over 240 hours of wind profiles were obtained with the GLOW lidar in support of a variety of scientific investigations.

  4. Long-term ferry-based observations of the suspended sediment fluxes through the Marsdiep inlet using acoustic Doppler current profilers

    NASA Astrophysics Data System (ADS)

    Nauw, J. J.; Merckelbach, L. M.; Ridderinkhof, H.; van Aken, H. M.

    2014-03-01

    Long-term measurements with a hull mounted acoustic Doppler current profiler (ADCP) under the ferry, crossing the Marsdiep inlet between the mainland and the island of Texel (the Netherlands), were used to determine the volume flux and the flux of suspended particulate matter (SPM) through this inlet for the period 2003-2005. Profiles of the SPM concentration were estimated from profiles of the acoustic backscatter intensity in which the shift between the low and the high turbulent regime is taken into account. Calibration constants and tuning parameters were estimated by using data collected during 7 different 13 hour anchor stations. The residual (water) volume flux through the inlet appears to vary strongly on a variety of time scales from daily to inter-annual. A regression analysis indicates that the daily residual volume transport correlates well with the daily mean wind component from the south; the latter likely drives the residual flow along the coast of Holland. The observed residual SPM transport of 7 to 11 Mton/yr is dominated by the correlation between tidal velocity and SPM concentration variations. This leads to an import as currents and SPM concentrations during flood were higher than those during ebb, a process generally known as tidal asymmetry. Our analysis has shown that regular observations with a ferry mounted ADCP is an effective method to monitor the volume and SPM transport processes in an estuary.

  5. Flight parameter estimation using instantaneous frequency and direction of arrival measurements from a single acoustic sensor node.

    PubMed

    Lo, Kam W

    2017-03-01

    When an airborne sound source travels past a stationary ground-based acoustic sensor node in a straight line at constant altitude and constant speed that is not much less than the speed of sound in air, the movement of the source during the propagation of the signal from the source to the sensor node (commonly referred to as the "retardation effect") enables the full set of flight parameters of the source to be estimated by measuring the direction of arrival (DOA) of the signal at the sensor node over a sufficiently long period of time. This paper studies the possibility of using instantaneous frequency (IF) measurements from the sensor node to improve the precision of the flight parameter estimates when the source spectrum contains a harmonic line of constant frequency. A simplified Cramer-Rao lower bound analysis shows that the standard deviations in the estimates of the flight parameters can be reduced when IF measurements are used together with DOA measurements. Two flight parameter estimation algorithms that utilize both IF and DOA measurements are described and their performances are evaluated using both simulated data and real data.

  6. Gap-Prepulse Inhibition of the Acoustic Startle Reflex (GPIAS) for Tinnitus Assessment: Current Status and Future Directions

    PubMed Central

    Galazyuk, Alexander; Hébert, Sylvie

    2015-01-01

    The progress in the field of tinnitus largely depends on the development of a reliable tinnitus animal model. Recently, a new method based on the acoustic startle reflex modification was introduced for tinnitus screening in laboratory animals. This method was enthusiastically adopted and now widely used by many scientists in the field due to its seeming simplicity and a number of advantages over the other methods of tinnitus assessment. Furthermore, this method opened an opportunity for tinnitus assessment in humans as well. Unfortunately, multiple modifications of data collection and interpretation implemented in different labs make comparisons across studies very difficult. In addition, recent animal and human studies have challenged the original “filling-in” interpretation of the paradigm. Here, we review the current literature to emphasize on the commonalities and differences in data collection and interpretation across laboratories that are using this method for tinnitus assessment. We also propose future research directions that could be taken in order to establish whether or not this method is warranted as an indicator of the presence of tinnitus. PMID:25972836

  7. Target spectrum matrix definition for multiple-input- multiple-output control strategies applied on direct-field- acoustic-excitation tests

    NASA Astrophysics Data System (ADS)

    Alvarez Blanco, M.; Janssens, K.; Bianciardi, F.

    2016-09-01

    During the last two decades there have been several improvements on environmental acoustic qualification testing for launch and space vehicles. Direct field excitation (DFAX) tests using Multiple-Input-Multiple-Output (MIMO) control strategies seems to become the most cost-efficient way for component and subsystem acoustic testing. However there are still some concerns about the uniformity and diffusivity of the acoustic field produced by direct field testing. Lately, much of the documented progresses aimed to solve the non-uniformity of the field by altering the sound pressure level requirement, limiting responses and adding or modifying control microphones positions. However, the first two solutions imply modifying the qualification criteria, which could lead to under-testing, potentially risking the mission. Furthermore, adding or moving control microphones prematurely changes the system configuration, even if it is an optimal geometric layout in terms of wave interference patterns control. This research investigates the target definition as an initial condition for the acoustic MIMO control. Through experiments it is shown that for a given system configuration the performance of a DFAX test strongly depends on the target definition procedure. As output of this research a set of descriptors are presented describing a phenomenon defined as “Energy- sink”.

  8. Field evaluation of a direct push deployed sensor probe for vertical soil water content profiling

    NASA Astrophysics Data System (ADS)

    Vienken, Thomas; Reboulet, Ed; Leven, Carsten; Kreck, Manuel; Zschornack, Ludwig; Dietrich, Peter

    2015-04-01

    Reliable high-resolution information about vertical variations in soil water content, i.e. total porosity in the saturated zone, is essential for flow and transport predictions within the subsurface. However, porosity measurements are often associated with high efforts and high uncertainties, e.g. caused by soil disturbance during sampling or sensor installation procedures. In hydrogeological practice, commonly applied tools for the investigation of vertical soil water content distribution include gravimetric laboratory analyses of soil samples and neutron probe measurements. A yet less well established technique is the use of direct push-deployed sensor probes. Each of these methods is associated with inherent advantages and limitations due to their underlying measurement principles and operation modes. The presented study describes results of a joint field evaluation of the individual methods under different depositional and hydrogeological conditions with special focus on the performance on the direct push-deployed water content profiler. Therefore, direct push-profiling results from three different test sites are compared with results obtained from gravimetric analysis of soil cores and neutron probe measurements. In direct comparison, the applied direct push-based sensor probe proved to be a suitable alternative for vertical soil water content profiling to neutron probe technology, and, in addition, proved to be advantageous over gravimetric analysis in terms vertical resolution and time efficiency. Results of this study identify application-specific limitations of the methods and thereby highlight the need for careful data evaluation, even though neutron probe measurements and gravimetric analyses of soil samples are well established techniques (see Vienken et al. 2013). Reference: Vienken, T., Reboulet, E., Leven, C., Kreck, M., Zschornack, L., Dietrich, P., 2013. Field comparison of selected methods for vertical soil water content profiling. Journal of

  9. Direct-push geochemical profiling for assessment of inorganic chemical heterogeneity in aquifers

    USGS Publications Warehouse

    Schulmeister, M.K.; Healey, J.M.; Butler, J.J.; McCall, G.W.

    2004-01-01

    Discrete-depth sampling of inorganic groundwater chemistry is essential for a variety of site characterization activities. Although the mobility and rapid sampling capabilities of direct-push techniques have led to their widespread use for evaluating the distribution of organic contaminants, complementary methods for the characterization of spatial variations in geochemical conditions have not been developed. In this study, a direct-push-based approach for high-resolution inorganic chemical profiling was developed at a site where sharp chemical contrasts and iron-reducing conditions had previously been observed. Existing multilevel samplers (MLSs) that span a fining-upward alluvial sequence were used for comparison with the direct-push profiling. Chemical profiles obtained with a conventional direct-push exposed-screen sampler differed from those obtained with an adjacent MLS because of sampler reactivity and mixing with water from previous sampling levels. The sampler was modified by replacing steel sampling components with stainless-steel and heat-treated parts, and adding an adapter that prevents mixing. Profiles obtained with the modified approach were in excellent agreement with those obtained from an adjacent MLS for all constituents and parameters monitored (Cl, NO3, Fe, Mn, DO, ORP, specific conductance and pH). Interpretations of site redox conditions based on field-measured parameters were supported by laboratory analysis of dissolved Fe. The discrete-depth capability of this approach allows inorganic chemical variations to be described at a level of detail that has rarely been possible. When combined with the mobility afforded by direct-push rigs and on-site methods of chemical analysis, the new approach is well suited for a variety of interactive site-characterization endeavors. ?? 2003 Elsevier B.V. All rights reserved.

  10. The Codacs™ direct acoustic cochlear implant actuator: exploring alternative stimulation sites and their stimulation efficiency.

    PubMed

    Grossöhmichen, Martin; Salcher, Rolf; Kreipe, Hans-Heinrich; Lenarz, Thomas; Maier, Hannes

    2015-01-01

    This work assesses the efficiency of the Codacs system actuator (Cochlear Ltd., Sydney Australia) in different inner ear stimulation modalities. Originally the actuator was intended for direct perilymph stimulation after stapedotomy using a piston prosthesis. A possible alternative application is the stimulation of middle ear structures or the round window (RW). Here the perilymph stimulation with a K-piston through a stapes footplate (SFP) fenestration (N = 10) as well as stimulation of the stapes head (SH) with a Bell prosthesis (N = 9), SFP stimulation with an Omega/Aerial prosthesis (N = 8) and reverse RW stimulation (N = 10) were performed in cadaveric human temporal bones (TBs). Codacs actuator output is expressed as equivalent sound pressure level (eq. SPL) using RW and SFP displacement responses, measured by Laser Doppler velocimetry as reference. The axial actuator coupling force in stimulation of stapes and RW was adjusted to ~5 mN. The Bell prosthesis and Omega/Aerial prosthesis stimulation generated similar mean eq. SPLs (Bell: 127.5-141.8 eq. dB SPL; Omega/Aerial: 123.6-143.9 eq. dB SPL), being significantly more efficient than K-piston perilymph stimulation (108.6-131.6 eq. dB SPL) and RW stimulation (108.3-128.2 eq. dB SPL). Our results demonstrate that SH, SFP and RW are adequate alternative stimulation sites for the Codacs actuator using coupling prostheses and an axial coupling force of ~5 mN. Based on the eq. SPLs, all investigated methods were adequate for in vivo hearing aid applications, provided that experimental conditions including constant coupling force will be implemented.

  11. The Codacs™ Direct Acoustic Cochlear Implant Actuator: Exploring Alternative Stimulation Sites and Their Stimulation Efficiency

    PubMed Central

    Grossöhmichen, Martin; Salcher, Rolf; Kreipe, Hans-Heinrich; Lenarz, Thomas; Maier, Hannes

    2015-01-01

    This work assesses the efficiency of the Codacs system actuator (Cochlear Ltd., Sydney Australia) in different inner ear stimulation modalities. Originally the actuator was intended for direct perilymph stimulation after stapedotomy using a piston prosthesis. A possible alternative application is the stimulation of middle ear structures or the round window (RW). Here the perilymph stimulation with a K-piston through a stapes footplate (SFP) fenestration (N = 10) as well as stimulation of the stapes head (SH) with a Bell prosthesis (N = 9), SFP stimulation with an Omega/Aerial prosthesis (N = 8) and reverse RW stimulation (N = 10) were performed in cadaveric human temporal bones (TBs). Codacs actuator output is expressed as equivalent sound pressure level (eq. SPL) using RW and SFP displacement responses, measured by Laser Doppler velocimetry as reference. The axial actuator coupling force in stimulation of stapes and RW was adjusted to ~ 5 mN. The Bell prosthesis and Omega/Aerial prosthesis stimulation generated similar mean eq. SPLs (Bell: 127.5–141.8 eq. dB SPL; Omega/Aerial: 123.6–143.9 eq. dB SPL), being significantly more efficient than K-piston perilymph stimulation (108.6–131.6 eq. dB SPL) and RW stimulation (108.3–128.2 eq. dB SPL). Our results demonstrate that SH, SFP and RW are adequate alternative stimulation sites for the Codacs actuator using coupling prostheses and an axial coupling force of ~ 5 mN. Based on the eq. SPLs, all investigated methods were adequate for in vivo hearing aid applications, provided that experimental conditions including constant coupling force will be implemented. PMID:25785860

  12. Indoor acoustic gain design

    NASA Astrophysics Data System (ADS)

    Concha-Abarca, Justo Andres

    2002-11-01

    The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.

  13. Discovery of non-directional and directional pioneer transcription factors by modeling DNase profile magnitude and shape

    PubMed Central

    Lewis, Sophia; Barkal, Amira A; van Hoff, John Peter; Karun, Vivek; Jaakkola, Tommi; Gifford, David K

    2014-01-01

    Here we describe Protein Interaction Quantitation (PIQ), a computational method that models the magnitude and shape of genome-wide DNase profiles to facilitate the identification of transcription factor (TF) binding sites. Through the use of machine learning techniques, PIQ identified binding sites for >700 TFs from one DNase-seq experiment with accuracy comparable to ChIP-seq for motif-associated TFs (median AUC=0.93 across 303 TFs). We applied PIQ to analyze DNase-seq data from mouse embryonic stem cells differentiating into pre-pancreatic and intestinal endoderm. We identified (n=120) and experimentally validated eight ‘pioneer’ TF families that dynamically open chromatin, enabling other TFs to bind to adjacent DNA. Four pioneer TF families only open chromatin in one direction from their motifs. Furthermore, we identified a class of ‘settler’ TFs whose genomic binding is principally governed by proximity to open chromatin. Our results support a model of hierarchical TF binding in which directional and non-directional pioneer activity shapes the chromatin landscape for population by settler TFs. PMID:24441470

  14. DIASCoPE: Directly integrated acoustic system combined with pressure experiments—A new method for fast acoustic velocity measurements at high pressure

    NASA Astrophysics Data System (ADS)

    Whitaker, Matthew L.; Baldwin, Kenneth J.; Huebsch, William R.

    2017-03-01

    A new experimental system to measure elastic wave velocities in samples in situ under extreme conditions of pressure and temperature in a multi-anvil apparatus has been installed at Beamline 6-BM-B of the Advanced Photon Source at Argonne National Laboratory. This system allows for measurement of acoustic velocities via ultrasonic interferometry, and makes use of the synchrotron beam to measure sample densities via X-ray diffraction and sample lengths using X-radiographic imaging. This system is fully integrated into the automated software controls of the beamline and is capable of collecting robust data on elastic wave travel times in less than 1 s, which is an improvement of more than one to two orders of magnitude over existing systems. Moreover, this fast data collection time has been shown to have no effect on the obtained travel time results. This allows for more careful study of time-dependent phenomena with tighter snapshots in time of processes that would otherwise be lost or averaged out in other acoustic measurement systems.

  15. Profile measurements and data from the 2011 Optics, Acoustics, and Stress In Situ (OASIS) project at the Martha's Vineyard Coastal Observatory

    USGS Publications Warehouse

    Sherwood, Christopher R.; Dickhudt, Patrick J.; Martini, Marinna A.; Montgomery, Ellyn T.; Boss, Emmanuel S.

    2012-01-01

    This report documents data collected by the U.S. Geological Survey (USGS) for the Coastal Model Applications and Field Measurements project under the auspices of the U.S. Navy Office of Naval Research Optics, Acoustics, and Stress In Situ (OASIS) Project. The objective of the measurements was to relate optical and acoustic properties of suspended particles to changes in particle size, concentration, and vertical distribution in the bottom boundary layer near the seafloor caused by wave- and current-induced stresses. This information on the physics of particle resuspension and aggregation and light penetration and water clarity will help improve models of sediment transport, benthic primary productivity, and underwater visibility. There is well-established technology for acoustic profiling, but optical profiles are more difficult to obtain because of the rapid attenuation of light in water. A specially modified tripod with a moving arm was designed to solve this problem by moving instruments vertically in the bottom boundary layer, between the bottom and about 2 meters above the seafloor. The profiling arm was designed, built, and tested during spring and summer 2011 by a team of USGS scientists, engineers, and technicians. To accommodate power requirements and the large data files recorded by some of the optical instruments, the tripod was connected via underwater cable to the Martha's Vineyard Coastal Observatory, operated by the Woods Hole Oceanographic Institution (WHOI). This afforded real-time Internet communication with the embedded computers aboard the tripod. Instruments were mounted on the profiling arm, and additional instruments were mounted elsewhere on the tripod and nearby on the seafloor. The tripod and a small mooring for a profiling current meter were deployed on September 17, 2011, at the Martha's Vineyard Coastal Observatory 12-meter-deep underwater node about 2 kilometers south of Martha's Vineyard, Massachusetts. Divers assisted in the

  16. Description and evaluation of the Acoustic Profiling of Ocean Currents (APOC) system used on R. V. Oceanus cruise 96 on 11-22 May 1981

    NASA Technical Reports Server (NTRS)

    Joyce, T. M.; Rintoul, S. R., Jr.; Barbour, R. L.

    1982-01-01

    The underway current profiling system which consists of a microprocessor controlled data logger that collects and formats data from a four beam Ametek-Straza 300 kHz acoustic Doppler current profiler, heading from the ship's gyrocompass, and navigation information from a Loran-C receiver and a satellite navigation unit is discussed. Data are recorded on magnetic tape and real time is calculated. Time averaging is required to remove effects of ship motion. An intercomparison is made with a moored vector measuring current meter (VMCM). The mean difference in hourly averaged APOC and VMCM currents over the four hour intercomparison is a few mm s minus including: two Gulf Stream crossings, a warm core ring survey, and shallow water in a frontal zone to the east of Nantucket Shoals.

  17. Integrating fluorescent dye flow-curve testing and acoustic Doppler velocimetry profiling for in situ hydraulic evaluation and improvement of clarifier performance.

    PubMed

    Tarud, F; Aybar, M; Pizarro, G; Cienfuegos, R; Pastén, P

    2010-08-01

    Enhancing the performance of clarifiers requires a thorough understanding of their hydraulics. Fluorescence spectroscopy and acoustic doppler velocimeter (ADV) profiling generally have been used separately to evaluate secondary settlers. We propose that simultaneous use of these techniques is needed to obtain a more reliable and useful evaluation. Experiments were performed on laboratory- and full-scale clarifiers. Factors affecting Fluorescein and Rhodamine 6G properties were identified. Underestimations up to 500% in fluorescence intensities may be derived from differential fluorescence quenching by oxygen. A careful control and interpretation of fluorescent dye experiments is needed to minimize artifacts in real settings. While flow-curve tests constructed under controlled conditions provided a more accurate overall quantitative estimation of the hydraulic performance, ADV velocity and turbulence profiling provided a detailed spatial understanding of flow patterns that was used to troubleshoot and fix the causes of hydraulic short-circuits.

  18. Direct chemical profiling of olive (Olea europaea) fruit epicuticular waxes by direct electrospray-ultrahigh resolution mass spectrometry.

    PubMed

    Vichi, Stefania; Cortés-Francisco, Nuria; Romero, Agustí; Caixach, Josep

    2015-03-01

    In the present paper, an electrospray ionization (ESI)-Orbitrap method is proposed for the direct chemical profiling of epicuticular wax (EW) from Olea europaea fruit. It constitutes a rapid and efficient tool suitable for a wide-ranging screening of a large number of samples. In a few minutes, the method provides a comprehensive characterization of total EW extracts, based on the molecular formula of their components. Accurate mass measurements are obtained by ultrahigh resolution mass spectrometry, and compositional restrictions are set on the basis of the information available from previous studies of olive EW. By alternating positive and negative ESI modes within the same analysis, complementary results are obtained and a wide range of chemical species is covered. This provides a detailed compositional overview that otherwise would only be available by applying multiple analytical techniques.

  19. Direct Electrospray Ionization Mass Spectrometric Profiling of Real-World Samples via a Solid Sampling Probe

    NASA Astrophysics Data System (ADS)

    Yu, Zhan; Chen, Lee Chuin; Mandal, Mridul Kanti; Yoshimura, Kentaro; Takeda, Sen; Hiraoka, Kenzo

    2013-10-01

    This study presents a novel direct analysis strategy for rapid mass spectrometric profiling of biochemicals in real-world samples via a direct sampling probe (DSP) without sample pretreatments. Chemical modification is applied to a disposable stainless steel acupuncture needle to enhance its surface area and hydrophilicity. After insertion into real-world samples, biofluid can be attached on the DSP surface. With the presence of a high DC voltage and solvent vapor condensing on the tip of the DSP, analyte can be dissolved and electrosprayed. The simplicity in design, versatility in application aspects, and other advantages such as low cost and disposability make this new method a competitive tool for direct analysis of real-world samples.

  20. Metabolite identification and profiling in drug design: current practice and future directions.

    PubMed

    Zhang, Zhoupeng; Zhu, Mingshe; Tang, Wei

    2009-01-01

    Drug metabolism and pharmacokinetics (DMPK) represents a critical component in support of drug discovery and development. This is because the therapeutic efficacy of a drug is dependent on its exposure which in turn is dictated in part by metabolic stability of the molecule. In addition, drug metabolism may lead to the formation of metabolites that can either be pharmacologically active or elicit adverse effect. On this basis, metabolite identification and profiling have become a routine exercise during lead optimization and subsequent development processes. The current communication provides an overview on the account of metabolite identification and profiling in support of drug design with an additional emphasis on the commonly used analytical techniques. The discussion is supported by case studies. Future directions are discussed in the context of newer platforms of technology and bioanalytical approaches enabling better operation efficiency in pharmaceutical research.

  1. Direct determination of the calcium profile structure for dipalmitoyllecithin multilayers using neutron diffraction.

    PubMed Central

    Herbette, L; Napolitano, C A; McDaniel, R V

    1984-01-01

    The distribution of calcium in lamellar phases of dipalmitoyllecthin (DPPC) multilayers was directly determined by neutron diffraction and stable isotope substitution of 44Ca for 40Ca. A significant resonance effect on the intensities of the lamellar diffraction pattern was observed for millimolar concentrations of these calcium isotopes. The calcium difference profile indicated that calcium was localized in the phospholipid headgroup region, being excluded from the hydrocarbon core as was water separately determined from the water profile structure obtained by H2O/D2O exchange. A reciprocal space analysis of the difference structure factors indicated that calcium binds preferentially to within 1-2 A of the phosphate moiety of the phospholipid head groups of the DPPC bilayer. PMID:6549146

  2. Acoustic profiling in a complexly social species, the American crow: caws encode information on caller sex, identity, and behavioural context

    PubMed Central

    Mates, Exu Anton; Tarter, Robin R.; Ha, James C.; Clark, Anne B.; McGowan, Kevin J.

    2014-01-01

    Previous research on inter-individual variation in the calls of corvids has largely been restricted to single call types, such as alarm or contact calls, and has rarely considered the effects of age on call structure. This study explores structural variation in a contextually diverse set of “caw” calls of the American crow (Corvus brachyrhynchos), including alarm, foraging recruitment and territorial calls, and searches for structural features that may be associated with behavioural context and caller sex, age, and identity. Automated pitch detection algorithms are used to generate 23 pitch-related and spectral parameters for a collection of caws from 18 wild, marked crows. Using principal component analysis and mixed models, we identify independent axes of acoustic variation associated with behavioural context and with caller sex, respectively. We also have moderate success predicting caller sex and identity from call structure. However, we do not find significant acoustic variation with respect to caller age. PMID:25419053

  3. Permeability profiles in granular aquifers using flowmeters in direct-push wells

    USGS Publications Warehouse

    Paradis, D.; Lefebvre, R.; Morin, R.H.; Gloaguen, E.

    2011-01-01

    Numerical hydrogeological models should ideally be based on the spatial distribution of hydraulic conductivity (K), a property rarely defined on the basis of sufficient data due to the lack of efficient characterization methods. Electromagnetic borehole flowmeter measurements during pumping in uncased wells can effectively provide a continuous vertical distribution of K in consolidated rocks. However, relatively few studies have used the flowmeter in screened wells penetrating unconsolidated aquifers, and tests conducted in gravel-packed wells have shown that flowmeter data may yield misleading results. This paper describes the practical application of flowmeter profiles in direct-push wells to measure K and delineate hydrofacies in heterogeneous unconsolidated aquifers having low-to-moderate K (10-6 to 10-4 m/s). The effect of direct-push well installation on K measurements in unconsolidated deposits is first assessed based on the previous work indicating that such installations minimize disturbance to the aquifer fabric. The installation and development of long-screen wells are then used in a case study validating K profiles from flowmeter tests at high-resolution intervals (15 cm) with K profiles derived from multilevel slug tests between packers at identical intervals. For 119 intervals tested in five different wells, the difference in log K values obtained from the two methods is consistently below 10%. Finally, a graphical approach to the interpretation of flowmeter profiles is proposed to delineate intervals corresponding to distinct hydrofacies, thus providing a method whereby both the scale and magnitude of K contrasts in heterogeneous unconsolidated aquifers may be represented. Journal compilation ?? 2010 National Ground Water Association.

  4. Towards direct realisation of the SI unit of sound pressure in the audible hearing range based on optical free-field acoustic particle measurements

    NASA Astrophysics Data System (ADS)

    Koukoulas, Triantafillos; Piper, Ben

    2015-04-01

    Since the introduction of the International System of Units (the SI system) in 1960, weights, measures, standardised approaches, procedures, and protocols have been introduced, adapted, and extensively used. A major international effort and activity concentrate on the definition and traceability of the seven base SI units in terms of fundamental constants, and consequently those units that are derived from the base units. In airborne acoustical metrology and for the audible range of frequencies up to 20 kHz, the SI unit of sound pressure, the pascal, is realised indirectly and without any knowledge or measurement of the sound field. Though the principle of reciprocity was originally formulated by Lord Rayleigh nearly two centuries ago, it was devised in the 1940s and eventually became a calibration standard in the 1960s; however, it can only accommodate a limited number of acoustic sensors of specific types and dimensions. International standards determine the device sensitivity either through coupler or through free-field reciprocity but rely on the continuous availability of specific acoustical artefacts. Here, we show an optical method based on gated photon correlation spectroscopy that can measure sound pressures directly and absolutely in fully anechoic conditions, remotely, and without disturbing the propagating sound field. It neither relies on the availability or performance of any measurement artefact nor makes any assumptions of the device geometry and sound field characteristics. Most importantly, the required units of sound pressure and microphone sensitivity may now be experimentally realised, thus providing direct traceability to SI base units.

  5. Towards direct realisation of the SI unit of sound pressure in the audible hearing range based on optical free-field acoustic particle measurements

    SciTech Connect

    Koukoulas, Triantafillos Piper, Ben

    2015-04-20

    Since the introduction of the International System of Units (the SI system) in 1960, weights, measures, standardised approaches, procedures, and protocols have been introduced, adapted, and extensively used. A major international effort and activity concentrate on the definition and traceability of the seven base SI units in terms of fundamental constants, and consequently those units that are derived from the base units. In airborne acoustical metrology and for the audible range of frequencies up to 20 kHz, the SI unit of sound pressure, the pascal, is realised indirectly and without any knowledge or measurement of the sound field. Though the principle of reciprocity was originally formulated by Lord Rayleigh nearly two centuries ago, it was devised in the 1940s and eventually became a calibration standard in the 1960s; however, it can only accommodate a limited number of acoustic sensors of specific types and dimensions. International standards determine the device sensitivity either through coupler or through free-field reciprocity but rely on the continuous availability of specific acoustical artefacts. Here, we show an optical method based on gated photon correlation spectroscopy that can measure sound pressures directly and absolutely in fully anechoic conditions, remotely, and without disturbing the propagating sound field. It neither relies on the availability or performance of any measurement artefact nor makes any assumptions of the device geometry and sound field characteristics. Most importantly, the required units of sound pressure and microphone sensitivity may now be experimentally realised, thus providing direct traceability to SI base units.

  6. Directional Profiles of Wind Speed and Turbulence Intensity over Forest and Open Land

    NASA Astrophysics Data System (ADS)

    Beyer, Elisabeth; Dietz, Sebastian; Pinter, Anna

    2014-05-01

    More and more wind turbines are built onshore and reduce the available areas for wind energy. Forests are additional potential for wind energy priority areas. But the high roughness of wooden areas and the resulting turbulences make it difficult to assess sites in forests. In order to cope with this problem some measurements were done inside and outside wooden areas. Therefore met masts equipped with ultra sonic and cup anemometers and LIDAR were used. With the measured wind speed and its standard deviation the turbulence intensity was calculated. The results are direction dependent profiles of wind speed and turbulence intensity.

  7. Vowel Acoustics in Dysarthria: Mapping to Perception

    PubMed Central

    Lansford, Kaitlin L.; Liss, Julie M.

    2014-01-01

    Purpose The aim of the present report was to explore whether vowel metrics, demonstrated to distinguish dysarthric and healthy speech in a companion article (Lansford & Liss, 2014), are able to predict human perceptual performance. Method Vowel metrics derived from vowels embedded in phrases produced by 45 speakers with dysarthria were compared with orthographic transcriptions of these phrases collected from 120 healthy listeners. First, correlation and stepwise multiple regressions were conducted to identify acoustic metrics that had predictive value for perceptual measures. Next, discriminant function analysis misclassifications were compared with listeners’ misperceptions to examine more directly the perceptual consequences of degraded vowel acoustics. Results Several moderate correlative relationships were found between acoustic metrics and perceptual measures, with predictive models accounting for 18%–75% of the variance in measures of intelligibility and vowel accuracy. Results of the second analysis showed that listeners better identified acoustically distinctive vowel tokens. In addition, the level of agreement between misclassified-to-misperceived vowel tokens supports some specificity of degraded acoustic profiles on the resulting percept. Conclusion Results provide evidence that degraded vowel acoustics have some effect on human perceptual performance, even in the presence of extravowel variables that naturally exert influence in phrase perception. PMID:24687468

  8. Vowel acoustics in dysarthria: mapping to perception.

    PubMed

    Lansford, Kaitlin L; Liss, Julie M

    2014-02-01

    The aim of the present report was to explore whether vowel metrics, demonstrated to distinguish dysarthric and healthy speech in a companion article (Lansford & Liss, 2014), are able to predict human perceptual performance. Vowel metrics derived from vowels embedded in phrases produced by 45 speakers with dysarthria were compared with orthographic transcriptions of these phrases collected from 120 healthy listeners. First, correlation and stepwise multiple regressions were conducted to identify acoustic metrics that had predictive value for perceptual measures. Next, discriminant function analysis misclassifications were compared with listeners' misperceptions to examine more directly the perceptual consequences of degraded vowel acoustics. Several moderate correlative relationships were found between acoustic metrics and perceptual measures, with predictive models accounting for 18%-75% of the variance in measures of intelligibility and vowel accuracy. Results of the second analysis showed that listeners better identified acoustically distinctive vowel tokens. In addition, the level of agreement between misclassified-to-misperceived vowel tokens supports some specificity of degraded acoustic profiles on the resulting percept. Results provide evidence that degraded vowel acoustics have some effect on human perceptual performance, even in the presence of extravowel variables that naturally exert influence in phrase perception.

  9. Assessing the Performance of Omni-Directional Receivers for Passive Acoustic Detection of Vocalizing Odontocetes: Initial Analysis

    DTIC Science & Technology

    2002-12-01

    anthropogenic noise is still not well understood ( Goold , 1997, and Madsen et al., 1999). It is however, generally accepted that the acoustic intensity of navy...45 LIST OF REFERENCES Goold , J. C., 1997. “Broadband Spectra of Seismic Survey Air-Gun Emissions, With Reference to Dolphin Auditory

  10. Acoustic Measurements in a Hexamethyldisiloxane-Loaded Low-Temperature Direct Barrier Discharge (DBD) Plasma Effluent: Nozzle Cleaning

    NASA Astrophysics Data System (ADS)

    Burkert, A.; Müller, D.; Paa, W.

    2015-04-01

    Acoustic emission (AE) measurements as well as laser light scattering experiments were performed during SiO2 layer deposition. SiO2 was generated in low-temperature atmospheric plasma torches (≤500 W), which were seeded with hexamethyldisiloxane. These AE measurements can be used to detect the necessity for nozzle cleaning online. The plasma torches were used to obtain high-quality SiO2 coatings. For electrical power of less than 350 W, we observed parasitic SiO2 deposition in the burner nozzle, which decreases the nozzle aperture within several hours of operation time. No parasitic SiO2 deposition inside the burner nozzle was observed when the plasma source was operated at more than 350 W. The reduced nozzle aperture causes increased plasma velocities and acoustic noise. Especially burst-like increases of this acoustic emission were assumed to be correlated to the ejection of particles. This hypothesis could be confirmed by measurements of scattered light from a sheet of laser light at 248 nm. The obtained correlations suggest using a microphone as a low-cost monitor for the degree of parasitic deposition inside the plasma burner nozzle. The threshold for acoustic noise detection has to be chosen low enough to avoid burst-like emission of particles.

  11. Profiling of K0 lateral stress coefficient in soils using paired directional G0 ratios

    NASA Astrophysics Data System (ADS)

    Ku, Taeseo; Mayne, Paul W.

    2013-07-01

    Using a special database compiled from directional shear wave velocity measurements at 12 well-documented sites, the geostatic stress state and stress history are evaluated from shear stiffness ratios. At each site, a benchmark profile of lateral stress coefficient (K0) was detailed using direct in-situ methods (i.e., self-boring pressuremeter, total stress cells, and/or hydraulic fracture), and/or laboratory methods (i.e., suction, consolidometer, and/or triaxial stress path testing). Also, the yield stress ratio (YSR), or more common parameter: overconsolidation ratio (OCR), was available either from series of consolidation tests on undisturbed samples procured from various depths and/or engineering geology studies, or both. Statistical expressions are derived to relate both K0 and OCR in terms of the ratio G0,HH/G0,VH as well as other factors.

  12. Discovery of directional and nondirectional pioneer transcription factors by modeling DNase profile magnitude and shape.

    PubMed

    Sherwood, Richard I; Hashimoto, Tatsunori; O'Donnell, Charles W; Lewis, Sophia; Barkal, Amira A; van Hoff, John Peter; Karun, Vivek; Jaakkola, Tommi; Gifford, David K

    2014-02-01

    We describe protein interaction quantitation (PIQ), a computational method for modeling the magnitude and shape of genome-wide DNase I hypersensitivity profiles to identify transcription factor (TF) binding sites. Through the use of machine-learning techniques, PIQ identified binding sites for >700 TFs from one DNase I hypersensitivity analysis followed by sequencing (DNase-seq) experiment with accuracy comparable to that of chromatin immunoprecipitation followed by sequencing (ChIP-seq). We applied PIQ to analyze DNase-seq data from mouse embryonic stem cells differentiating into prepancreatic and intestinal endoderm. We identified 120 and experimentally validated eight 'pioneer' TF families that dynamically open chromatin. Four pioneer TF families only opened chromatin in one direction from their motifs. Furthermore, we identified 'settler' TFs whose genomic binding is principally governed by proximity to open chromatin. Our results support a model of hierarchical TF binding in which directional and nondirectional pioneer activity shapes the chromatin landscape for population by settler TFs.

  13. Direct-push hydrostratigraphic profiling: Coupling electrical logging and slug tests

    USGS Publications Warehouse

    Sellwood, S.M.; Healey, J.M.; Birk, S.; Butler, J.J.

    2005-01-01

    Spatial variations in hydraulic conductivity (K) can significantly affect the transport of contaminants in ground water. Conventional field methods, however, rarely provide a description of these variations at the level of detail necessary for reliable transport predictions and effective remediation designs. A direct-push (DP) method, hydrostratigraphic profiling, has been developed to characterize the spatial variability of both electrical conductivity (EC) and hydraulic conductivity in unconsolidated formations in a cost-effective manner. This method couples a dual-rod approach for performing slug tests in DP equipment with high-resolution EC logging. The method was evaluated at an extensively studied site in the Kansas River floodplain. A series of profiles was performed on a surface grid, resulting in a detailed depiction of the three-dimensional distribution of EC and K. Good agreement was found between K estimates obtained from this approach and those obtained using other methods. The results of the field evaluation indicate that DP hydrostratigraphic profiling is a promising method for obtaining detailed information about spatial variations in subsurface properties without the need for permanent wells.

  14. A simple desalting method for direct MALDI mass spectrometry profiling of tissue lipids.

    PubMed

    Wang, Hay-Yan J; Liu, Cheng Bin; Wu, Hsuan-Wen

    2011-04-01

    Direct MALDI-mass spectrometry (MALDI-MS) profiling of tissue lipids often observes isobaric phosphatidylcholine (PC) species caused by the endogenous alkali metal ions that bias the relative abundance of tissue lipids. Fresh rat brain cryosections were washed with 70% ethanol (EtOH), water (H₂O), or 150 mM ammonium acetate (NH₄Ac), and the desalting effectiveness of each fluid was evaluated by MALDI-MS profiling of PC and sphingomyelin (SM) species in tissue and in the washing runoff. The results indicated that EtOH and H₂O only partially desalted the tissue lipids, yet both substantially displaced the tissue lipids to the washing runoffs. On the other hand, NH₄Ac effectively desalted the tissue lipids and produced a runoff containing no detectable PCs or SMs. NH₄Ac wash also unveiled the underlying changes of PCs and SMs in the infarcted rat cortex previously masked by edema-caused increase of tissue sodium. The MS/MS of an isobaric PC in the infarcted cortex revealed the precursor change as the result of NH₄Ac wash and confirmed the desalting effectiveness of such wash. Other than desalting, NH₄Ac wash also removes contaminants in tissue, enhances the overall spectral quality, and benefits additionally in profiling of biological molecules in tissue.

  15. Tropospheric and stratospheric wind profiling with a direct detection Doppler lidar

    NASA Technical Reports Server (NTRS)

    Abreu, Vincent J.; Barnes, John E.; Fischer, Ken W.; Skinner, Wilbert R.; Mcgill, Matt J.

    1992-01-01

    The Space Physics Research Laboratory at the University of Michigan has been operating a direct detection, high resolution Doppler Lidar (HRDL) to measure winds in the boundary layer, free troposphere and lower stratosphere. A direct detection Doppler lidar measures the Doppler shift of the aerosol or Rayleigh backscattered signal, from which the wind velocity vector can be retrieved (Benedetti-Michelangeli et al, 1972, 1974; Chanin et al., 1989; Abreu et al., 1992). The system components are shown. The transmitting system is a Continuum NY-60 Nd:YAG laser frequency doubled to a wavelength of 532 nm. The laser is injection seeded for single line mode operation yielding a linewidth of 0.0045 cm(exp -1) (135 MHz) with excellent shot-to-shot frequency stability. The laser produces 60 mJ pulses and operates at a 50 Hz repetition rate for an effective output power of 3.0 W. A description of the University of Michigan's Doppler lidar is given with examples of wind profiles for the boundary layer, free troposphere, and for the lower stratosphere. The system provides a reliable method of remotely measuring the wind. The wind error is smallest in regions of high aerosols. The system also produces aerosol extinction profiles versus altitude which can be determined by the shape of the spectra. The system has been installed in a trailor so that measurements can be made for field campaigns. Winds and aerosol data are available immediately at the site for use in forecasting.

  16. 3D acoustic atmospheric tomography

    NASA Astrophysics Data System (ADS)

    Rogers, Kevin; Finn, Anthony

    2014-10-01

    This paper presents a method for tomographically reconstructing spatially varying 3D atmospheric temperature profiles and wind velocity fields based. Measurements of the acoustic signature measured onboard a small Unmanned Aerial Vehicle (UAV) are compared to ground-based observations of the same signals. The frequency-shifted signal variations are then used to estimate the acoustic propagation delay between the UAV and the ground microphones, which are also affected by atmospheric temperature and wind speed vectors along each sound ray path. The wind and temperature profiles are modelled as the weighted sum of Radial Basis Functions (RBFs), which also allow local meteorological measurements made at the UAV and ground receivers to supplement any acoustic observations. Tomography is used to provide a full 3D reconstruction/visualisation of the observed atmosphere. The technique offers observational mobility under direct user control and the capacity to monitor hazardous atmospheric environments, otherwise not justifiable on the basis of cost or risk. This paper summarises the tomographic technique and reports on the results of simulations and initial field trials. The technique has practical applications for atmospheric research, sound propagation studies, boundary layer meteorology, air pollution measurements, analysis of wind shear, and wind farm surveys.

  17. Predicting link directionality in gene regulation from gene expression profiles using volatility-constrained correlation.

    PubMed

    Ochiai, Tomoshiro; Nacher, Jose C

    2016-07-01

    To uncover potential disease molecular pathways and signaling networks, we do not only need undirected maps but also we need to infer the directionality of functional or physical interactions between cellular components. A wide range of methods for identifying functional interactions between genes relies on correlations between experimental gene expression measurements to some extent. However, the standard Pearson or Spearman correlation-based approaches can only determine undirected correlations between cellular components. Here, we apply a volatility-constrained correlation method for gene expression profiles that offers a new metric to capture directionality of interactions between genes. To evaluate the predictions we used four datasets distributed by the DREAM5 network inference challenge including an in silico-constructed network and three organisms such as S. aureus, E. coli and S. cerevisiae. The predictions performed by our proposed method were compared to a gold standard of experimentally verified directionality of genetic regulatory links. Our findings show that our method successfully predicts the genetic interaction directionality with a success rate higher than 0.5 with high statistical significance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Design of acoustic beam aperture modifier using gradient-index phononic crystals

    NASA Astrophysics Data System (ADS)

    Lin, Sz-Chin Steven; Tittmann, Bernhard R.; Huang, Tony Jun

    2012-06-01

    This article reports the design concept of a novel acoustic beam aperture modifier using butt-jointed gradient-index phononic crystals (GRIN PCs) consisting of steel cylinders embedded in a homogeneous epoxy background. By gradually tuning the period of a GRIN PC, the propagating direction of acoustic waves can be continuously bent to follow a sinusoidal trajectory in the structure. The aperture of an acoustic beam can therefore be shrunk or expanded through change of the gradient refractive index profiles of the butt-jointed GRIN PCs. Our computational results elucidate the effectiveness of the proposed acoustic beam aperture modifier. Such an acoustic device can be fabricated through a simple process and will be valuable in applications, such as biomedical imaging and surgery, nondestructive evaluation, communication, and acoustic absorbers.

  19. Acoustic Neuroma

    MedlinePlus

    ... search IRSA's site Unique Hits since January 2003 Acoustic Neuroma Click Here for Acoustic Neuroma Practice Guideline ... to microsurgery. One doctor's story of having an acoustic neuroma In August 1991, Dr. Thomas F. Morgan ...

  20. Low frequency acoustic microscope

    DOEpatents

    Khuri-Yakub, Butrus T.

    1986-11-04

    A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

  1. Profiles.

    ERIC Educational Resources Information Center

    Macintosh, Henry G.

    An introduction to profiles is presented with examples provided to permit an overall appraisal of the potential of profiles, of the principles upon which they might be based, and of the problems that will have to be overcome if their potential is to be realized in practice. The larger scale examples of profiles discussed are the Scottish Pupil…

  2. Direct prediction of profiles of sequences compatible with a protein structure by neural networks with fragment-based local and energy-based nonlocal profiles.

    PubMed

    Li, Zhixiu; Yang, Yuedong; Faraggi, Eshel; Zhan, Jian; Zhou, Yaoqi

    2014-10-01

    Locating sequences compatible with a protein structural fold is the well-known inverse protein-folding problem. While significant progress has been made, the success rate of protein design remains low. As a result, a library of designed sequences or profile of sequences is currently employed for guiding experimental screening or directed evolution. Sequence profiles can be computationally predicted by iterative mutations of a random sequence to produce energy-optimized sequences, or by combining sequences of structurally similar fragments in a template library. The latter approach is computationally more efficient but yields less accurate profiles than the former because of lacking tertiary structural information. Here we present a method called SPIN that predicts Sequence Profiles by Integrated Neural network based on fragment-derived sequence profiles and structure-derived energy profiles. SPIN improves over the fragment-derived profile by 6.7% (from 23.6 to 30.3%) in sequence identity between predicted and wild-type sequences. The method also reduces the number of residues in low complex regions by 15.7% and has a significantly better balance of hydrophilic and hydrophobic residues at protein surface. The accuracy of sequence profiles obtained is comparable to those generated from the protein design program RosettaDesign 3.5. This highly efficient method for predicting sequence profiles from structures will be useful as a single-body scoring term for improving scoring functions used in protein design and fold recognition. It also complements protein design programs in guiding experimental design of the sequence library for screening and directed evolution of designed sequences. The SPIN server is available at http://sparks-lab.org. © 2014 Wiley Periodicals, Inc.

  3. Direct prediction of profiles of sequences compatible to a protein structure by neural networks with fragment-based local and energy-based nonlocal profiles

    PubMed Central

    Li, Zhixiu; Yang, Yuedong; Faraggi, Eshel; Zhan, Jian; Zhou, Yaoqi

    2014-01-01

    Locating sequences compatible to a protein structural fold is the well-known inverse protein-folding problem. While significant progress has been made, the success rate of protein design remains low. As a result, a library of designed sequences or profile of sequences is currently employed for guiding experimental screening or directed evolution. Sequence profiles can be computationally predicted by iterative mutations of a random sequence to produce energy-optimized sequences, or by combining sequences of structurally similar fragments in a template library. The latter approach is computationally more efficient but yields less accurate profiles than the former because of lacking tertiary structural information. Here we present a method called SPIN that predicts Sequence Profiles by Integrated Neural network based on fragment-derived sequence profiles and structure-derived energy profiles. SPIN improves over the fragment-derived profile by 6.7% (from 23.6% to 30.3%) in sequence identity between predicted and wild-type sequences. The method also reduces the number of residues in low complex regions by 15.7% and has a significant better balance of hydrophilic and hydrophobic residues at protein surfaces. The accuracy of sequence profiles obtained is comparable to those generated from the protein design program RosettaDesign 3.5. This highly efficient method for predicting sequence profiles from structures will be useful as a single-body scoring term for improving scoring functions used in protein design and fold recognition. It also complements protein design programs in guiding experimental design of the sequence library for screening and directed evolution of designed sequences. The SPIN server is available at http://sparks-lab.org. PMID:24898915

  4. Differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus

    PubMed Central

    He, Wen-Bo; Li, Jie; Liu, Shu-Sheng

    2015-01-01

    Plant viruses interact with their insect vectors directly and indirectly via host plants, and this tripartite interaction may produce fitness benefits to both the vectors and the viruses. Our previous studies show that the Middle East-Asia Minor 1 (MEAM1) species of the whitefly Bemisia tabaci complex improved its performance on tobacco plants infected by the Tomato yellow leaf curl China virus (TYLCCNV), which it transmits, although virus infection of the whitefly per se reduced its performance. Here, we use electrical penetration graph recording to investigate the direct and indirect effects of TYLCCNV on the feeding behaviour of MEAM1. When feeding on either cotton, a non-host of TYLCCNV, or uninfected tobacco, a host of TYLCCNV, virus-infection of the whiteflies impeded their feeding. Interestingly, when viruliferous whiteflies fed on virus-infected tobacco, their feeding activities were no longer negatively affected; instead, the virus promoted whitefly behaviour related to rapid and effective sap ingestion. Our findings show differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus, and help to unravel the behavioural mechanisms underlying a mutualistic relationship between an insect vector and a plant virus that also has features reminiscent of an insect pathogen. PMID:25567524

  5. Differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus.

    PubMed

    He, Wen-Bo; Li, Jie; Liu, Shu-Sheng

    2015-01-08

    Plant viruses interact with their insect vectors directly and indirectly via host plants, and this tripartite interaction may produce fitness benefits to both the vectors and the viruses. Our previous studies show that the Middle East-Asia Minor 1 (MEAM1) species of the whitefly Bemisia tabaci complex improved its performance on tobacco plants infected by the Tomato yellow leaf curl China virus (TYLCCNV), which it transmits, although virus infection of the whitefly per se reduced its performance. Here, we use electrical penetration graph recording to investigate the direct and indirect effects of TYLCCNV on the feeding behaviour of MEAM1. When feeding on either cotton, a non-host of TYLCCNV, or uninfected tobacco, a host of TYLCCNV, virus-infection of the whiteflies impeded their feeding. Interestingly, when viruliferous whiteflies fed on virus-infected tobacco, their feeding activities were no longer negatively affected; instead, the virus promoted whitefly behaviour related to rapid and effective sap ingestion. Our findings show differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus, and help to unravel the behavioural mechanisms underlying a mutualistic relationship between an insect vector and a plant virus that also has features reminiscent of an insect pathogen.

  6. Sediment distribution and dynamics inferred by integrated electromagnetic, optical and acoustic benthic profiling in the western Bay of Plenty (New Zealand)

    NASA Astrophysics Data System (ADS)

    Kulgemeyer, T.; von Dobeneck, T. F.; Müller, H.; Bryan, K. R.; de Lange, W. P.; Battershill, C.

    2015-12-01

    In October 2011, New Zealand experienced a marine pollution disaster after the MV RENA ran aground in the western Bay of Plenty. To estimate the transport and burial potential of contaminants, local sediment distribution and dynamics had to be assessed quickly. Our study made use of the benthic profiler NERIDIS III of the University of Bremen. 33 cross-shore profiles, each ca. 8 km long, have been surveyed. The main instrument is a controlled-source electromagnetic (CSEM) sensor, which is measuring the electric conductivity and magnetic susceptibility of the seafloor. High-resolution, overlapping seafloor photos have been taken by a bow-mounted digital camera. An on-board CTD with turbidity sensor complete the sensor arrangement. From the EM data, porosity and magnetite concentrations have been calculated and interpolated. The resulting maps show specific zones of magnetite enrichment, higher concentrations are correlated to low porosity. Photos have been used along with acoustic backscatter measured by a sidescan sonar to sketch out a preliminary map of sediment facies. Based on this, sides for grab sampling were selected. By taking grain size and mineralogy into account, a detailed map of the regional lithofacies could be created. Local sediment dynamics have been inferred by the observation of bedforms, the turbidity of bottom water and lithofacies. The results show two anti-parallel longshore transport paths dependent on differing weather conditions and water depths. The longshore magnetite distribution indicates that the heavy mineral fraction is mainly affected by storm-induced sediment transport. Our study demonstrates how integrated benthic profiling adds to the interpretability of data obtained by established methods. By bridging the gap between area-covering, but indirect data from hydroacoustics and precise, but punctual data from samples, benthic profiling enables fast and detailed assessment of sediment distribution and dynamics on a large scale.

  7. An optical technique for measuring divergence, beam profile, and aiming direction, of relativistic negative hydrogen ions

    SciTech Connect

    Hershcovitch, A.

    1988-02-01

    A novel, nonobstructive diagnostic technique for high energy H/sup minus/D/sup minus/ ion beams is described. This scheme employs spectroscopic techniques designed to measure beam profile, perpendicular velocity spread (i.e., divergence), and orientation of multiMeV H/sup minus/ beams. The basic principle of this method is to photoneutralize a small portion of the H/sup minus/ beam in a way such that the photodetachment process results in the formation of excited hydrogen atoms in the n = 2 levels. Observation of fluorescence from spontaneous decay of H(sp) andor induced deacy of H(2s) can be readily used to determine beam profile. Doppler broadening measurements can be used to determine velocity spread from which beam emittance is calculated. With off-the-shelf instruments resolutions of 1 mm for beam profile and 2 x 10/sup minus/2) ..pi.. cm-mrad are possible. For photodetachment, the best commercially available laser is found to be ArF eximer laser. The analysis is performed for the 200 MEV BNL Linac. The laser, which has a pulse duration which has a pulse duration which is of 10/sup minus/5) of the linac can produce sufficient signal at a negligible beam loss. In addition, measurements of minute Doppler shifts of this Lyman-Alpha radiation by a spectrograph could in principle resolve beam direction to within 1.57 ..mu..rad. The process under consideration has a resonance known as the shape resonance. As the following literature review indicates, the total cross section is known and there is a reasonable agreement between theory and experiment. There are no experimental measurements of partical cross sections. nevertheless, there are theoretical estimates which agree within 15%. 10 refs., 1 fig.

  8. [Direct proteome profiling of human blood serum in the experiment with 5-day dry immersion].

    PubMed

    Pastushkova, L Kh; Pakharukova, N A; Trifonova, O P; Dobrokhotov, I V; Valeeva, O A; Larina, I M

    2011-01-01

    Purpose of the investigation was to determine changes in blood plasma proteome in healthy human subjects (n = 14, 19 to 26 y.o.) in an experiment with dry immersion (DI). Plasma samples were drawn 7 and 2 days before the exposure, on DI days 2, 3 and 5, and on days 1, 3, 7 and 15 after the experiment. Previous to direct MALDI-TOF mass-spectrometric profiling, serum samples were pre-fractionated and enriched with magnetic particles MB WCX (WCX--a weak cation exchanger) on ClinProt (Bruker Daltonics). In each spectrum, 175 MS-peaks were detected on average within the mass range from 1000 to 17,000 Da with the signal/noise ratio = 5. Student's criterion (p < 0.05) was used to define reliable differences between DI and baseline samples from 48 peaks (27.4 % of all the proteome profile peaks). On DI days 2 and 3, growth of peak areas was observed in fragments of complement system proteins C3 and C4, high-molecular kininogen and fibrinogen that can be attributed to organism adaptation to conditions of the experiment. Significant increases of the peak area of apolipoprotein CI (reduced form with segregated threonine and proline) and C4 enzymes of the complement system, and fibrinogen on the first day after the experiment can be related to changes in motor activities of the subjects.

  9. Profiling of Piper betle Linn. cultivars by direct analysis in real time mass spectrometric technique.

    PubMed

    Bajpai, Vikas; Sharma, Deepty; Kumar, Brijesh; Madhusudanan, K P

    2010-12-01

    Piper betle Linn. is a traditional plant associated with the Asian and southeast Asian cultures. Its use is also recorded in folk medicines in these regions. Several of its medicinal properties have recently been proven. Phytochemical analysis showed the presence of mainly terpenes and phenols in betel leaves. These constituents vary in the different cultivars of Piper betle. In this paper we have attempted to profile eight locally available betel cultivars using the recently developed mass spectral ionization technique of direct analysis in real time (DART). Principal component analysis has also been employed to analyze the DART MS data of these betel cultivars. The results show that the cultivars of Piper betle could be differentiated using DART MS data.

  10. Direct imaging of Joule heating dynamics and temperature profiling inside a carbon nanotube interconnect.

    PubMed

    Costa, Pedro M F J; Gautam, Ujjal K; Bando, Yoshio; Golberg, Dmitri

    2011-08-09

    Understanding resistive (or Joule) heating in fundamental nanoelectronic blocks, such as carbon nanotubes, remains a major challenge, particularly in regard to their structural and thermal variations during prolonged periods of electrical stress. Here we show real-time imaging of the associated effects of Joule heating in the channel of carbon nanotube interconnects. First, electrical contacts to nanotubes entirely filled with a sublimable material are made inside a transmission electron microscope. On exposure to a high current density, resistive hotspots are identified on (or near) the contact points. These later migrate and expand along the carbon nanotube, as indicated by the localized sublimation of the encapsulated material. Using the hotspot edges as markers, it is possible to estimate the internal temperature profiles of the nanotube. Simple and direct, our method provides remarkable spatial and temporal insights into the dynamics of resistive hotspots and millisecond-paced thermal variations occurring inside nanoscaled tubular interconnects.

  11. Direct-path acoustic ranging across the Japan Trench axis, Adjacent to the Large Shallow Thrusting in the 2011 Tohoku-Oki earthquake

    NASA Astrophysics Data System (ADS)

    Osada, Y.; Kido, M.; Ito, Y.; Iinuma, T.; Fujimoto, H.; Hino, R.

    2014-12-01

    Seafloor geodetic data, i.e. GPS/acoustic measurement and continuous seafloor pressure monitoring, brought important evidences showing that the 2011 Tohoku-oki earthquake (Mw 9.0) caused huge (> 50 m) coseismic slip near the Japan Trench. The postseismic behavior of the large slipped area is required to clarify to understand why large amount seismic slip could occur there. We started making direct-path acoustic ranging across the trench axis to reveal the convergence rate between the subducting Pacific and overriding continental plates. We expect the change of the baseline length across the trench axis, the plate boundary, reflects the slip rate at the shallow megathrust, which is difficult to estimate only from other geodetic observations largely affected by intraplate deformation caused by the postseismic viscoelastic relaxation process.  To this end, we developed an ultra-deep seafloor acoustic ranging system. Our previous ranging systems have been designed to measure baseline length ~ 1 km and to be deployed up to 7,000 m water-depth (Osada et al., 2008, 2012). In order to realize the measurement across the Japan Trench, we improved this system to enhance range of acoustic ranging as well as operational depth of instruments. The improved system was designed to allow acoustic ranging up to 3 km and to be durable under the high-pressure equivalent to water depth of 9,000 m. In May 2013, we carried out a test deployment of the new ranging system. The system is composed of three seafloor instruments equipped with precision transponder (PXPs). Two of the PXPs were set on the landward slope of the Japan Trench, where large coseismic slip happened in 2011. Another PXP was deployed on the seaward side of the trench so that the baseline change associated with the slip on the plate boundary fault, if any, can be detected. Continuous records of baseline lengths were successfully obtained for four months. The repeatability of the distance measurements was about 20 mm for

  12. Focused subsurface flow in the Amargosa Desert characterized by direct-current resistivity profiling

    NASA Astrophysics Data System (ADS)

    Stonestrom, D. A.; Abraham, J. D.; Lucius, J. E.; Prudic, D. E.

    2003-12-01

    Environmental-tracer studies have shown that ground-water recharge in the thick alluvial fill of the Amargosa Desert is localized beneath ephemeral stream channels and anthropogenic sources of water, with little recharge beneath native vegetation on interfluvial areas under current climatic conditions. These borehole-based studies provided relatively robust but limited, one-dimensional (vertical) information that can be only tentatively regionalized using geomorphologic, pedologic, and vegetational mapping. The ability of direct-current (DC) resistivity profiling to complement and extend studies of the spatial distribution of subsurface flow was examined by making surface-based measurements ("soundings") along one transect normal to the depositional fabric in each of three geomorphologically distinct settings: a well-incised ephemeral channel system, a poorly incised (distributory) ephemeral channel system, and an interfluvial upland. Linear arrays of 32 to 80 electrodes were deployed with a uniform 2 to 5-m spacing between adjacent electrodes. A multiplexing 8-channel resistivity instrument made automated inverse-Schlumberger-array soundings along the deployed line, using up to 10 electrodes at a time. The line was shifted piecemeal until composite transects consisted of 168 to 232 electrode positions. This approach allowed rapid profiling of long transects at high resolution. Numerical inversions assumed horizontal constancy normal to the vertical slices being imaged, producing solution sets of optimized resistivity values for several thousand points within each modeled slice. Imaged slices were ˜30 to 80 m deep and ˜1 km wide. RMS errors between apparent resistivities in the model inversions and field-measured apparent resistivities were ˜10%. On the basis of borehole studies, inverted resistivity (ρ ) values denoted three categories of alluvium: (1) low-water-content coarse gravel and highly desiccated surface materials, with ρ > ˜200 Ω -m, (2) vertical

  13. Estimating sea-ice coverage, draft, and velocity in Marguerite Bay (Antarctica) using a subsurface moored upward-looking acoustic Doppler current profiler (ADCP)

    NASA Astrophysics Data System (ADS)

    Hyatt, Jason; Visbeck, Martin; Beardsley, Robert C.; Brechner Owens, W.

    2008-02-01

    A technique for the analysis of data from a subsurface moored upward-looking acoustic Doppler current profiler (ADCP) to determine ice coverage, draft and velocity is presented and applied to data collected in Marguerite Bay on the western Antarctic Peninsula shelf. This method provides sea-ice information when no dedicated upward-looking sonar (ULS) data are available. Ice detection is accomplished using windowed variances of ADCP vertical velocity, vertical error velocity, and surface horizontal speed. ADCP signal correlation and backscatter intensity were poor indicators of the presence of ice at this site. Ice draft is estimated using a combination of ADCP backscatter data, atmospheric and oceanic pressure data, and information about the thermal stratification. This estimate requires corrections to the ADCP-derived range for instrument tilt and sound speed profile. Uncertainties of ±0.20 m during midwinter and ±0.40 m when the base of the surface mixed layer is above the ADCP for ice draft are estimated based on: (a) a Monte Carlo simulation, (b) uncertainty in the sound speed correction, and (c) performance of the zero-draft estimate during times of known open water. Ice velocity is taken as the ADCP horizontal velocity in the depth bin specified by the range estimate.

  14. Temporal characteristics of coherent flow structures generated over alluvial sand dunes, Mississippi River, revealed by acoustic doppler current profiling and multibeam echo sounding

    USGS Publications Warehouse

    Czuba, John A.; Oberg, Kevin A.; Best, Jim L.; Parsons, Daniel R.; Simmons, S. M.; Johnson, K.K.; Malzone, C.

    2009-01-01

    This paper investigates the flow in the lee of a large sand dune located at the confluence of the Mississippi and Missouri Rivers, USA. Stationary profiles collected from an anchored boat using an acoustic Doppler current profiler (ADCP) were georeferenced with data from a real-time kinematic differential global positioning system. A multibeam echo sounder was used to map the bathymetry of the confluence and provided a morphological context for the ADCP measurements. The flow in the lee of a low-angle dune shows good correspondence with current conceptual models of flow over dunes. As expected, quadrant 2 events (upwellings of low-momentum fluid) are associated with high backscatter intensity. Turbulent events generated in the lower lee of a dune near the bed are associated with periods of vortex shedding and wake flapping. Remnant coherent structures that advect over the lower lee of the dune in the upper portion of the water column, have mostly dissipated and contribute little to turbulence intensities. The turbulent events that occupy most of the water column in the upper lee of the dune are associated with periods of wake flapping.

  15. Introducing DIASCoPE: Directly Integrated Acoustic System Combined with Pressure Experiments — Changing the Paradigm from Product to Process

    NASA Astrophysics Data System (ADS)

    Whitaker, M. L.; Baldwin, K. J.; Huebsch, W. B.; Tercé, N.; Bejina, F.; Bystricky, M.; Chen, H.; Vaughan, M. T.; Weidner, D. J.

    2014-12-01

    Understanding the properties and behaviors of materials and multi-phase aggregates under conditions of high pressure and temperature is vital to unraveling the mysteries that lie beneath the surface of the planet. Advances in in situexperimental techniques using synchrotron radiation at these extreme conditions have helped to provide answers to fundamental questions that were previously unattainable. Synchrotron-based ultrasonic interferometry measurements have proven to be especially important in determining acoustic velocities and thermoelastic properties of materials at high pressures and temperatures. However, due to relatively slow data collection times, it has been difficult to measure the effects of processes as they occur, and instead the measurement is made on the end product of these processes. DIASCoPE is an important step toward addressing this problem.Over the last three years, we have designed and developed an on-board ultrasonic acoustic velocity measurement system that cuts data collection time down by over an order of magnitude. We can now measure P- and S-wave travel times in samples at extreme conditions in less than one second. Moreover, the system has been fully integrated with the multi-anvil apparatus and the EPICS control system at beamline X17B2 of the National Synchrotron Light Source, allowing for greater ease of control andfull automation of experimental data collection. The DIASCoPE has completed the testing and commissioning phase, and the first data collected using this powerful new system will be presented here.DIASCoPE represents a major step forward in acoustic velocity collection time reduction that will finally allow us to begin to witness what effects various processes in the deep Earth may have on the physical properties of materials at extreme conditions as they occur. These new capabilities will allow us to change the focus of study from the product to the process itself and will lead to a greater understanding of the

  16. Vertical profiles of BC direct radiative effect over Italy: high vertical resolution data and atmospheric feedbacks

    NASA Astrophysics Data System (ADS)

    Močnik, Griša; Ferrero, Luca; Castelli, Mariapina; Ferrini, Barbara S.; Moscatelli, Marco; Grazia Perrone, Maria; Sangiorgi, Giorgia; Rovelli, Grazia; D'Angelo, Luca; Moroni, Beatrice; Scardazza, Francesco; Bolzacchini, Ezio; Petitta, Marcello; Cappelletti, David

    2016-04-01

    Black carbon (BC), and its vertical distribution, affects the climate. Global measurements of BC vertical profiles are lacking to support climate change research. To fill this gap, a campaign was conducted over three Italian basin valleys, Terni Valley (Appennines), Po Valley and Passiria Valley (Alps), to characterize the impact of BC on the radiative budget under similar orographic conditions. 120 vertical profiles were measured in winter 2010. The BC vertical profiles, together with aerosol size distribution, aerosol chemistry and meteorological parameters, have been determined using a tethered balloon-based platform equipped with: a micro-Aethalometer AE51 (Magee Scientific), a 1.107 Grimm OPC (0.25-32 μm, 31 size classes), a cascade impactor (Siuotas SKC), and a meteorological station (LSI-Lastem). The aerosol chemical composition was determined from collected PM2.5 samples. The aerosol absorption along the vertical profiles was measured and optical properties calculated using the Mie theory applied to the aerosol size distribution. The aerosol optical properties were validated with AERONET data and then used as inputs to the radiative transfer model libRadtran. Vertical profiles of the aerosol direct radiative effect, the related atmospheric absorption and the heating rate were calculated. Vertical profile measurements revealed some common behaviors over the studied basin valleys. From below the mixing height to above it, a marked concentration drop was found for both BC (from -48.4±5.3% up to -69.1±5.5%) and aerosol number concentration (from -23.9±4.3% up to -46.5±7.3%). These features reflected on the optical properties of the aerosol. Absorption and scattering coefficients decreased from below the MH to above it (babs from -47.6±2.5% up to -71.3±3.0% and bsca from -23.5±0.8% up to -61.2±3.1%, respectively). Consequently, the Single Scattering Albedo increased above the MH (from +4.9±2.2% to +7.4±1.0%). The highest aerosol absorption was

  17. Metabolic profiling directly from the Petri dish using nanoDESI imaging mass spectrometry

    PubMed Central

    Watrous, Jeramie; Roach, Patrick; Heath, Brandi; Alexandrov, Theodore; Laskin, Julia; Dorrestein, Pieter C.

    2014-01-01

    Understanding molecular interaction pathways in complex biological systems constitutes a treasure trove of knowledge that might facilitate the specific, chemical manipulation of the countless microbiological systems that occur throughout our world. However, there is a lack of methodologies that allow the direct investigation of chemical gradients and interactions in living biological systems, in real time. Here we report the use of nanospray desorption electrospray ionization (nanoDESI) imaging mass spectrometry for in vivo metabolic profiling of living bacterial colonies directly from the Petri dish with absolutely no sample preparation needed. Using this technique, we investigated single colonies of Shewanella oneidensis MR-1, Bacillus subtilis 3610, Streptomyces coelicolor A3(2) as well as a mixed biofilm of S. oneidensis MR-1 and B. subtilis 3610. Data from B. subtilis 3610 and S. coelicolor A3(2) provided a means of validation for the method while data from S. oneidensis MR-1 and the mixed biofilm showed a wide range of compounds that this bacterium uses for the dissimilatory reduction of extracellular metal oxides, including riboflavin, iron-bound heme and heme biosynthetic intermediates, and the siderophore putrebactin. PMID:24047514

  18. Metabolic Profiling Directly from the Petri Dish Using Nanospray Desorption Electrospray Ionization Imaging Mass Spectrometry

    SciTech Connect

    Watrous, Jeramie D.; Roach, Patrick J.; Heath, Brandi S.; Alexandrov, Theodore; Laskin, Julia; Dorrestein, Pieter C.

    2013-11-05

    Understanding molecular interaction pathways in complex biological systems constitutes a treasure trove of knowledge that might facilitate the specific, chemical manipulation of the countless microbiological systems that occur throughout our world. However, there is a lack of methodologies that allow the direct investigation of chemical gradients and interactions in living biological systems, in real time. Here, we report the use of nanospray desorption electrospray ionization (nanoDESI) imaging mass spectrometry for in vivo metabolic profiling of living bacterial colonies directly from the Petri dish with absolutely no sample preparation needed. Using this technique, we investigated single colonies of Shewanella oneidensis MR-1, Bacillus subtilis 3610, and Streptomyces coelicolor A3(2) as well as a mixed biofilm of S. oneidensis MR-1 and B. subtilis 3610. Data from B. subtilis 3610 and S. coelicolor A3(2) provided a means of validation for the method while data from S. oneidensis MR-1 and the mixed biofilm showed a wide range of compounds that this bacterium uses for the dissimilatory reduction of extracellular metal oxides, including riboflavin, iron-bound heme and heme biosynthetic intermediates, and the siderophore putrebactin.

  19. Reflected wavefront manipulation based on ultrathin planar acoustic metasurfaces

    PubMed Central

    Li, Yong; Liang, Bin; Gu, Zhong-ming; Zou, Xin-ye; Cheng, Jian-chun

    2013-01-01

    The introduction of metasurfaces has renewed the Snell's law and opened up new degrees of freedom to tailor the optical wavefront at will. Here, we theoretically demonstrate that the generalized Snell's law can be achieved for reflected acoustic waves based on ultrathin planar acoustic metasurfaces. The metasurfaces are constructed with eight units of a solid structure to provide discrete phase shifts covering the full 2π span with steps of π/4 by coiling up the space. By careful selection of the phase profiles in the transverse direction of the metasurfaces, some fascinating wavefront engineering phenomena are demonstrated, such as anomalous reflections, conversion of propagating waves into surface waves, planar aberration-free lens and nondiffracting Bessel beam generated by planar acoustic axicon. Our results could open up a new avenue for acoustic wavefront engineering and manipulations. PMID:23986034

  20. Virtual Acoustics

    NASA Astrophysics Data System (ADS)

    Lokki, Tapio; Savioja, Lauri

    The term virtual acoustics is often applied when sound signal is processed to contain features of a simulated acoustical space and sound is spatially reproduced either with binaural or with multichannel techniques. Therefore, virtual acoustics consists of spatial sound reproduction and room acoustics modeling.

  1. Acoustic dispersive prism

    NASA Astrophysics Data System (ADS)

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  2. Acoustic dispersive prism.

    PubMed

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R

    2016-01-07

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  3. Acoustic dispersive prism

    PubMed Central

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium. PMID:26739504

  4. Liquid lens using acoustic radiation force.

    PubMed

    Koyama, Daisuke; Isago, Ryoichi; Nakamura, Kentaro

    2011-03-01

    A liquid lens is proposed that uses acoustic radiation force with no mechanical moving parts. It consists of a cylindrical acrylic cell filled with two immiscible liquids (degassed water and silicone oil) and a concave ultrasound transducer. The focal point of the transducer is located on the oil-water interface, which functions as a lens. The acoustic radiation force is generated when there is a difference in the acoustic energy densities of different media. An acoustic standing wave was generated in the axial direction of the lens and the variation of the shape of the oil-water interface was observed by optical coherence tomography (OCT). The lens profile can be rapidly changed by varying the acoustic radiation force from the transducer. The kinematic viscosity of silicone oil was optimized to minimize the response times of the lens. Response times of 40 and 80 ms when switching ultrasonic radiation on and off were obtained with a kinematic viscosity of 200 cSt. The path of a laser beam transmitted through the lens was calculated by ray-tracing simulations based on the experimental results obtained by OCT. The transmitted laser beam could be focused by applying an input voltage. The liquid lens could be operated as a variable-focus lens by varying the input voltage.

  5. Effect of direct-to-consumer genomewide profiling to assess disease risk.

    PubMed

    Bloss, Cinnamon S; Schork, Nicholas J; Topol, Eric J

    2011-02-10

    The use of direct-to-consumer genomewide profiling to assess disease risk is controversial, and little is known about the effect of this technology on consumers. We examined the psychological, behavioral, and clinical effects of risk scanning with the Navigenics Health Compass, a commercially available test of uncertain clinical validity and utility. We recruited subjects from health and technology companies who elected to purchase the Health Compass at a discounted rate. Subjects reported any changes in symptoms of anxiety, intake of dietary fat, and exercise behavior at a mean (±SD) of 5.6±2.4 months after testing, as compared with baseline, along with any test-related distress and the use of health-screening tests. From a cohort of 3639 enrolled subjects, 2037 completed follow-up. Primary analyses showed no significant differences between baseline and follow-up in anxiety symptoms (P=0.80), dietary fat intake (P=0.89), or exercise behavior (P=0.61). Secondary analyses revealed that test-related distress was positively correlated with the average estimated lifetime risk among all the assessed conditions (β=0.117, P<0.001). However, 90.3% of subjects who completed follow-up had scores indicating no test-related distress. There was no significant increase in the rate of use of screening tests associated with genomewide profiling, most of which are not considered appropriate for screening asymptomatic persons in any case. In a selected sample of subjects who completed follow-up after undergoing consumer genomewide testing, such testing did not result in any measurable short-term changes in psychological health, diet or exercise behavior, or use of screening tests. Potential effects of this type of genetic testing on the population at large are not known. (Funded by the National Institutes of Health and Scripps Health.).

  6. Spatial profiles of interelectrode electron density in direct current superposed dual-frequency capacitively coupled plasmas

    NASA Astrophysics Data System (ADS)

    Ohya, Yoshinobu; Ishikawa, Kenji; Komuro, Tatsuya; Yamaguchi, Tsuyoshi; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

    2017-04-01

    We present experimentally determined spatial profiles of the interelectrode electron density (n e) in dual-frequency capacitively coupled plasmas in which the negative direct current (dc) bias voltage (V dc) is superposed; in the experiment, 13 MHz (P low) was applied to the lower electrode and 60 MHz (P high) to the upper electrode. The bulk n e increased substantially with increases in the external power, P high, P low, and with increases in V dc. When P low was insufficient, the bulk n e decreased as the V dc bias increased. The bulk n e increased due to its dependence on V dc, especially for |V dc|  >  500 V. This may correspond to the sheath voltages (V s) of the lower electrode. The n e values in front of the upper electrode were coupled with the V dc: the V dc dependence first decreased and then increased. The dc currents (I dc) of the upper electrode were collected when a large P low was applied. The value of I dc at the threshold value of V dc  ≈  V s (e.g.  ‑500 V) increased with an increase in n e. When |V dc| exceeded the threshold, the spatial n e profile and the I dc dependence were changed relative to the electrical characteristics of the dc superposition; this led to a change in the location of the maximum n e, the width of the area of n e depletion in front of the electrodes, and a transition in the electron heating modes.

  7. Direct profiling of environmental microbial populations by thermal dissociation analysis of native rRNAs hybridized to oligonucleotide microarrays

    NASA Technical Reports Server (NTRS)

    El Fantroussi, Said; Urakawa, Hidetoshi; Bernhard, Anne E.; Kelly, John J.; Noble, Peter A.; Smidt, H.; Yershov, G. M.; Stahl, David A.

    2003-01-01

    Oligonucleotide microarrays were used to profile directly extracted rRNA from environmental microbial populations without PCR amplification. In our initial inspection of two distinct estuarine study sites, the hybridization patterns were reproducible and varied between estuarine sediments of differing salinities. The determination of a thermal dissociation curve (i.e., melting profile) for each probe-target duplex provided information on hybridization specificity, which is essential for confirming adequate discrimination between target and nontarget sequences.

  8. Direct profiling of environmental microbial populations by thermal dissociation analysis of native rRNAs hybridized to oligonucleotide microarrays

    NASA Technical Reports Server (NTRS)

    El Fantroussi, Said; Urakawa, Hidetoshi; Bernhard, Anne E.; Kelly, John J.; Noble, Peter A.; Smidt, H.; Yershov, G. M.; Stahl, David A.

    2003-01-01

    Oligonucleotide microarrays were used to profile directly extracted rRNA from environmental microbial populations without PCR amplification. In our initial inspection of two distinct estuarine study sites, the hybridization patterns were reproducible and varied between estuarine sediments of differing salinities. The determination of a thermal dissociation curve (i.e., melting profile) for each probe-target duplex provided information on hybridization specificity, which is essential for confirming adequate discrimination between target and nontarget sequences.

  9. Application of acoustic full waveform inversion to retrieve high-resolution temperature and salinity profiles from synthetic seismic data

    NASA Astrophysics Data System (ADS)

    Kormann, J.; Biescas, B.; Korta, N.; de La Puente, J.; SallarèS, V.

    2011-11-01

    Recent works show that multichannel seismic (MCS) systems are able to provide detailed information on the oceans' fine structure. The aim of this paper is to analyze whether 1-D full waveform inversion algorithms are suitable to recover the extremely weak acoustic impedance contrasts associated to the oceans' fine structure, as well as their potential to image meso-scale objects such as meddies. We limited our analysis to synthetic, noise-free data, in order to identify some methodological issues related to this approach under idealistic conditions (e.g., 1-D wave propagation, noise-free data, known source wavelet). We first discuss the influence of the starting model in the context of the multi-scale strategy that we have implemented. Then we show that it is possible to retrieve not only sound speed but also salinity and temperature contrasts within reasonable bounds from the seismic data using Neural Network relationships trained with regional oceanographic data sets. Potentially, the vertical resolution of the obtained models, which depends on the maximum frequency inverted, is of the order of 5-10 m, whereas the root mean square error of the inverted properties is shown to be ˜0.5 m/s for sound speed, 0.1°C for temperature, and 0.06 for salinity. To conclude this study, we have inverted synthetic data simulated along an oceanographic transect acquired during the EU-funded Geophysical Oceanography (GO) project. The results demonstrate the applicability of the method for synthetic data, as well as its potential to define oceanographic features along 2-D transects at full ocean depth with excellent lateral resolution.

  10. Profiles.

    ERIC Educational Resources Information Center

    School Arts, 1979

    1979-01-01

    Profiles seven Black, Native American, and Chicano artists and art teachers: Hale A. Woodruff, Allan Houser, Luis Jimenez, Betrand D. Phillips, James E. Pate, I, and Fernando Navarro. This article is part of a theme issue on multicultural art. (SJL)

  11. Profiles.

    ERIC Educational Resources Information Center

    School Arts, 1979

    1979-01-01

    Profiles seven Black, Native American, and Chicano artists and art teachers: Hale A. Woodruff, Allan Houser, Luis Jimenez, Betrand D. Phillips, James E. Pate, I, and Fernando Navarro. This article is part of a theme issue on multicultural art. (SJL)

  12. Pharmacodynamic effects of oral oxymorphone: Abuse liability, analgesic profile and direct physiological effects in humans

    PubMed Central

    Babalonis, Shanna; Lofwall, Michelle R.; Nuzzo, Paul A.; Walsh, Sharon L.

    2015-01-01

    Oxymorphone is a semisynthetic μ-opioid agonist, marketed as a prescription analgesic purported to be twice as potent as oxycodone for pain relief. Oral formulations of oxymorphone were re-introduced in the United States in 2006 and reports of abuse ensued; however, there are limited data available on its pharmacodynamic effects. The current study aimed to examine the direct physiological effects, relative abuse liability, analgesic profile, and overall pharmacodynamic potency of oxymorphone in comparison to identical doses of oxycodone. Healthy, non-dependent opioid abusers (n=9) were enrolled in this within-subject, double-blind, placebo-controlled, 3-week inpatient study. Seven experimental sessions (6.5 hr) were conducted, during which an oral dose of immediate-release formulations of oxymorphone (10, 20, 40 mg), oxycodone (10, 20, 40 mg) or placebo was administered. An array of physiological, abuse liability and experimental pain measures was collected. At identical doses, oxymorphone produced approximately two-fold less potent effects on miosis, compared to oxycodone. Oxymorphone also produced lesser magnitude effects on measures of respiratory depression, two experimental pain models, and observer-rated agonist effects. However, 40 mg of oxymorphone was similar to 40 mg of oxycodone on several abuse-related subjective ratings. Formal relative potency analyses were largely invalid due to the substantially greater effects of oxycodone. Overall, oxymorphone is less potent on most pharmacodynamic measures, although at higher doses, its abuse liability is similar to oxycodone. These data suggest that the published clinical equianalgesic estimates may not be consistent with the observed direct physiological effects of opioids, results of experimental pain models or abuse liability measures, as assessed in the human laboratory. PMID:25130052

  13. Acoustic Characteristics of Long Calls Produced by Male Orang-Utans (Pongo pygmaeus wurmbii): Advertising Individual Identity, Context, and Travel Direction.

    PubMed

    Askew, James A; Morrogh-Bernard, Helen C

    2016-01-01

    Acoustic characteristics and context of the long-distance call of male orang-utans (Pongo pygmaeus wurmbii) were examined in a population of orang-utans from Central Kalimantan, Borneo. Male orang-utans produced long calls under different circumstances, including calls made spontaneously, in response to conspecifics, when accompanied by a snag crash and when travelling with a female. It was shown by acoustic analyses that there was individual discrimination between the male's calls, discrimination between the calls made under different contexts, and between calls from one individual from different years, which coincided with a change in his dominance status. We also confirm that flanged male orang-utans advertise their intended travel route, by long calling in the direction of their travel. If other orang-utans (males and females) within ear shot of the caller can identify the caller from their long call, and even obtain information about the context and status of the individual, they can then therefore choose whether to approach or avoid them. Thus, males seem to be using their long call to announce their presence, allowing them to orient themselves spatially to other orang-utans, and, potentially, to co-ordinate a network of loose associations between both males and females in the area.

  14. Acoustic integrated extinction

    PubMed Central

    Norris, Andrew N.

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122, 3206–3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we derive a formula for the acoustic IE that is valid for causal and non-causal scattering. The general result is expressed as an integral of the time-dependent forward scattering function. The IE reduces to a finite integral for scatterers with zero long-wavelength monopole and dipole amplitudes. Implications for acoustic cloaking are discussed and a new metric is proposed for broadband acoustic transparency. PMID:27547100

  15. Direct Mapping of Magnetic and Structural Profiles of Electric Field Moderated Oxygen Migration

    NASA Astrophysics Data System (ADS)

    Gilbert, Dustin A.; Grutter, Alexander J.; Kirby, Brian J.; Borchers, Julie A.; Maranville, Brian B.; Arenholz, Elke; Liu, Kai

    Recent studies on metal/oxide heterostructures have demonstrated control of interfacial magnetic anisotropy and saturation magnetization in ultrathin (5 ML) Co films through electric-field controlled oxygen migration. This approach presents a promising route to realizing next-generation, ultralow power sensor and data-storage technologies. Here we demonstrate magnetoelectric coupling moderated by electrically-driven oxygen migration in much thicker AlOx(1 um)/GdOx(2 nm)/Co (15 nm) heterostructures. Using polarized neutron reflectometry, we present direct, quantitative depth profiling of the magnetization and oxygen concentration in these systems. Electro-thermal conditioning moves oxygen from AlOx and GdOx base-layers throughout the entire thickness of the 15 nm Co layer, resulting in a suppressed magnetization. Switching the electric field polarity semi-reversibly ejects oxygen preferentially from the GdOX/Co interface, partially recovering the magnetization and establishing a practical limit to this approach. First order reversal curve diagrams show that the conditioned samples exhibit two distinct magnetic phases, while the as-grown samples are single phase, suggesting that the treatments alters the Co film microstructure. X-ray spectroscopy confirms the oxidation states of the Co and Gd, and suggest that the GdOX acts to transmit oxygen but does not source or sink it.

  16. Electrophysiological Profiles of Induced Neurons Converted Directly from Adult Human Fibroblasts Indicate Incomplete Neuronal Conversion

    PubMed Central

    Koppensteiner, Peter; Boehm, Stefan

    2014-01-01

    Abstract The direct conversion of human fibroblasts to neuronal cells, termed human induced neuronal (hiN) cells, has great potential for future clinical advances. However, previous studies have not provided an in-depth analysis of electrophysiological properties of adult fibroblast-derived hiN cultures. We have examined the electrophysiological profile of hiN cells by measuring passive and active membrane properties, as well as spontaneous and evoked neurotransmission. We found that hiN cells exhibited passive membrane properties equivalent to perinatal rodent neurons. In addition, 30% of hiN cells were incapable of action potential (AP) generation and did not exhibit rectifying membrane currents, and none of the cells displayed firing patterns of typical glutamatergic pyramidal neurons. Finally, hiN cells exhibited neither spontaneous nor evoked neurotransmission. Our results suggest that current methods used to produce hiN cells provide preparations in which cells do not achieve the cellular properties of fully mature neurons, rendering these cells inadequate to investigate pathophysiological mechanisms. PMID:25437871

  17. Application of acoustic-Doppler current profiler and expendable bathythermograph measurements to the study of the velocity structure and transport of the Gulf Stream

    NASA Technical Reports Server (NTRS)

    Joyce, T. M.; Dunworth, J. A.; Schubert, D. M.; Stalcup, M. C.; Barbour, R. L.

    1988-01-01

    The degree to which Acoustic-Doppler Current Profiler (ADCP) and expendable bathythermograph (XBT) data can provide quantitative measurements of the velocity structure and transport of the Gulf Stream is addressed. An algorithm is used to generate salinity from temperature and depth using an historical Temperature/Salinity relation for the NW Atlantic. Results have been simulated using CTD data and comparing real and pseudo salinity files. Errors are typically less than 2 dynamic cm for the upper 800 m out of a total signal of 80 cm (across the Gulf Stream). When combined with ADCP data for a near-surface reference velocity, transport errors in isopycnal layers are less than about 1 Sv (10 to the 6th power cu m/s), as is the difference in total transport for the upper 800 m between real and pseudo data. The method is capable of measuring the real variability of the Gulf Stream, and when combined with altimeter data, can provide estimates of the geoid slope with oceanic errors of a few parts in 10 to the 8th power over horizontal scales of 500 km.

  18. Understanding Secondary Flows in Rivers Using a Combination of Acoustic Doppler Current Profiler Measurements and a Finite Volume solution to the Navier-Stokes Equations.

    NASA Astrophysics Data System (ADS)

    Furtak-Cole, E.

    2016-12-01

    Hydraulic processes in rivers are central to issues of river ecosystem health, contaminant transport, and essential to understanding meander dynamics. In particular, large scale secondary flows are often cited as being the driving force behind river bend shape and migration. We seek to understand the fundamental flow patterns in rivers by augmenting field-collected bathymetry and velocity data with computational fluid dynamics (CFD) simulation. This approach has successfully been applied to flume studies, but rarely used in a natural setting. Here, complex geometries, lack of data, large woody debris, riprap, and biased measurements all present difficulties. Velocity and bathymetry data were collected over multiple consecutive days on a reach of the Minnesota river in Belle Plaine with an acoustic Doppler current profiler (ADCP). Time averaging and interpolation of velocity vectors along transects reveal coarse scale secondary flow patterns, including an outer bank cell. A mesh was created from bathymetry data for use with the openFOAM C++ library. A hydraulics study is conducted by solving the Navier-Stokes equations with a slip condition free-surface and large eddy simulation turbulence model. Results are compared to field-measured data, and areas affected by downed trees and riprap are identified. We show that modelling at the coarse scale can provide useful information for understanding river hydraulics and predicting sediment transport over large domains.

  19. An uncooked vegan diet shifts the profile of human fecal microflora: computerized analysis of direct stool sample gas-liquid chromatography profiles of bacterial cellular fatty acids.

    PubMed Central

    Peltonen, R; Ling, W H; Hänninen, O; Eerola, E

    1992-01-01

    The effect of an uncooked extreme vegan diet on fecal microflora was studied by direct stool sample gas-liquid chromatography (GLC) of bacterial cellular fatty acids and by quantitative bacterial culture by using classical microbiological techniques of isolation, identification, and enumeration of different bacterial species. Eighteen volunteers were divided randomly into two groups. The test group received an uncooked vegan diet for 1 month and a conventional diet of mixed Western type for the other month of the study. The control group consumed a conventional diet throughout the study period. Stool samples were collected. Bacterial cellular fatty acids were extracted directly from the stool samples and measured by GLC. Computerized analysis of the resulting fatty acid profiles was performed. Such a profile represents all bacterial cellular fatty acids in a sample and thus reflects its microflora and can be used to detect changes, differences, or similarities of bacterial flora between individual samples or sample groups. GLC profiles changed significantly in the test group after the induction and discontinuation of the vegan diet but not in the control group at any time, whereas quantitative bacterial culture did not detect any significant change in fecal bacteriology in either of the groups. The results suggest that an uncooked extreme vegan diet alters the fecal bacterial flora significantly when it is measured by direct stool sample GLC of bacterial fatty acids. PMID:1482187

  20. Preliminary evaluation of turbofan cycle parameters and acoustical suppression on the noise and direct operating cost of a commercial Mach 0.85 transport

    NASA Technical Reports Server (NTRS)

    Eisenberg, J. D.

    1975-01-01

    A study was made of the effects of turbofan cycle parameters and the use of acoustic noise suppression material to quiet 200 passenger, Mach 0.85 trijets having design ranges of 2778, 4630, and 9260 kilometers (1500, 2500, and 5000 n. mi). Aircraft gross weight and direct operating cost, which varied with amount of suppression and cycle selection, are presented as functions of both EPNdB traded and 90 EPNdB contour footprint area. Noise levels 10.9 EPNdB below FAR 36 requirements result in a 5 percent increase in DOC for an aircraft designed for a range of 9260 kilometers (5000 n. mi.). An aircraft designed for a 2778 kilometer (1500 n. mi.) range would have an EPNdB level 14 below FAR 36 for this same economic penalty. In this range of noise level, fan-machinery noise is the principal source.

  1. Interest Profile Elevation, Big Five Personality Traits, and Secondary Constructs on the Self-Directed Search: A Replication and Extension

    ERIC Educational Resources Information Center

    Bullock, Emily E.; Reardon, Robert C.

    2008-01-01

    The study used the Self-Directed Search (SDS) and the NEO-FFI to explore profile elevation, four secondary constructs, and the Big Five personality factors in a sample of college students in a career course. Regression model results showed that openness, conscientiousness, differentiation high-low, differentiation Iachan, and consistency accounted…

  2. Transcriptome profiles of chicken intestinal intraepithelial lymphocytes altered by the intake of a multi-strain direct-fed microbials

    USDA-ARS?s Scientific Manuscript database

    The current study was conducted to investigate the effects of the direct-fed microbials (DFM) including three Bacillus subtilis strains on the modulation of transcriptional profile in chicken intestinal intraepithelial lymphocytes (IEL). The multiple-strain DFM product modified 453 probes from 1,98...

  3. Acoustic Neuroma

    MedlinePlus

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. ... can press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the ...

  4. High-Speed Vortex Wind Velocity Imaging by Acoustic Tomography

    NASA Astrophysics Data System (ADS)

    Li, H.; Ueki, T.; Hayashi, K.; Yamada, A.

    A technique for monitoring strong vortex wind fields is highly desired due to the rapid development of global warming. Vortex wind velocity imaging using an acoustic travel time tomography technique was developed to meet this need. The method can be implemented with a small number of parallel facing pairs of acoustic transmitters/receivers from just a single illumination view direction, so that high-speed data acquisition compatible with instantaneous wind-flow imaging was accomplished. A test using an indoor wind velocity tomography system demonstrated that vortex wind velocity profiles generated by an electric fan could be instantaneously reconstructed with satisfactory quantitative precision.

  5. Acoustic well cleaner

    DOEpatents

    Maki, Jr., Voldi E.; Sharma, Mukul M.

    1997-01-21

    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.

  6. Acoustical heat pumping engine

    DOEpatents

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

    1983-08-16

    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.

  7. Acoustical heat pumping engine

    DOEpatents

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1983-08-16

    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.

  8. Broadband asymmetric acoustic transmission through an acoustic prism

    NASA Astrophysics Data System (ADS)

    Song, Ailing; Chen, Tianning; Wang, Xiaopeng; Xi, Yanhui

    2017-08-01

    Narrow bandwidth and complex structure are the main shortcomings of the existing asymmetric acoustic transmission devices. In this letter, a simple broadband asymmetric acoustic transmission device is proposed by using an acoustic prism filled with xenon gas. The sound pressure field distributions, the transmission spectra, and the prism angle effect are numerically investigated by using finite element method. The proposed device can always realize asymmetric acoustic transmission for the wave frequency larger than 480 Hz because the wave paths are not influenced by the wave frequencies. The asymmetric acoustic transmission is attributed to normal refraction and total reflection occur at different interfaces. Besides, relatively high transmission efficiency is realized due to the similar impedance between the acoustic prism and background. And the transmitted wave direction can be controlled freely by changing the prism angle. Our design provides a simple method to obtain broadband asymmetric acoustic transmission device and has potentials in many applications, such as noise control and medical ultrasound.

  9. Direct RNA motif definition and identification from multiple sequence alignments using secondary structure profiles.

    PubMed

    Gautheret, D; Lambert, A

    2001-11-09

    We present here a new approach to the problem of defining RNA signatures and finding their occurrences in sequence databases. The proposed method is based on "secondary structure profiles". An RNA sequence alignment with secondary structure information is used as an input. Two types of weight matrices/profiles are constructed from this alignment: single strands are represented by a classical lod-scores profile while helical regions are represented by an extended "helical profile" comprising 16 lod-scores per position, one for each of the 16 possible base-pairs. Database searches are then conducted using a simultaneous search for helical profiles and dynamic programming alignment of single strand profiles. The algorithm has been implemented into a new software, ERPIN, that performs both profile construction and database search. Applications are presented for several RNA motifs. The automated use of sequence information in both single-stranded and helical regions yields better sensitivity/specificity ratios than descriptor-based programs. Furthermore, since the translation of alignments into profiles is straightforward with ERPIN, iterative searches can easily be conducted to enrich collections of homologous RNAs. Copyright 2001 Academic Press.

  10. Acoustic Seaglider

    DTIC Science & Technology

    2008-03-07

    a national naval responsibility. Acoustic sensors on mobile, autonomous platforms will enable basic research topics on temporal and spatial...problem and acoustic navigation and communications within the context of distributed autonomous persistent undersea surveillance sensor networks...Acoustic sensors on mobile, autonomous platforms will enable basic research topics on temporal and spatial coherence and the description of ambient

  11. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  12. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  13. Ultrasonic field profile evaluation in acoustically inhomogeneous anisotropic materials using 2D ray tracing model: Numerical and experimental comparison.

    PubMed

    Kolkoori, S R; Rahman, M-U; Chinta, P K; Ktreutzbruck, M; Rethmeier, M; Prager, J

    2013-02-01

    Ultrasound propagation in inhomogeneous anisotropic materials is difficult to examine because of the directional dependency of elastic properties. Simulation tools play an important role in developing advanced reliable ultrasonic non destructive testing techniques for the inspection of anisotropic materials particularly austenitic cladded materials, austenitic welds and dissimilar welds. In this contribution we present an adapted 2D ray tracing model for evaluating ultrasonic wave fields quantitatively in inhomogeneous anisotropic materials. Inhomogeneity in the anisotropic material is represented by discretizing into several homogeneous layers. According to ray tracing model, ultrasonic ray paths are traced during its energy propagation through various discretized layers of the material and at each interface the problem of reflection and transmission is solved. The presented algorithm evaluates the transducer excited ultrasonic fields accurately by taking into account the directivity of the transducer, divergence of the ray bundle, density of rays and phase relations as well as transmission coefficients. The ray tracing model is able to calculate the ultrasonic wave fields generated by a point source as well as a finite dimension transducer. The ray tracing model results are validated quantitatively with the results obtained from 2D Elastodynamic Finite Integration Technique (EFIT) on several configurations generally occurring in the ultrasonic non destructive testing of anisotropic materials. Finally, the quantitative comparison of ray tracing model results with experiments on 32mm thick austenitic weld material and 62mm thick austenitic cladded material is discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Flight effects on the aerodynamic and acoustic characteristics of inverted profile coannular nozzles, volume 2. [supersonic cruise aircraft research wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    Data from the acoustic tests of the convergent reference nozzle and the 0.75 area ratio coannular nozzle are presented in tables. Data processing routines used to scale the acoustic data and to correct the data for atmospheric attenuation are included.

  15. Direct evaluation of the position dependent diffusion coefficient and persistence time from the equilibrium density profile in anisotropic fluids.

    PubMed

    Olivares-Rivas, Wilmer; Colmenares, Pedro J; López, Floralba

    2013-08-21

    We derive expressions for the transverse diffusion coefficient D(z) and the average persistence time τ(z; L) within a layer of width L, for particles of a non-homogeneous fluid enclosed in a planar nanopore. The method allows the direct evaluation of these position-dependent dynamical quantities from the equilibrium local particle density profile. We use results for the density and persistence time profiles from the virtual layer molecular dynamics method to numerically assess the significance of the Smoluchowski approximation.

  16. Al2C Monolayer Sheet and Nanoribbons with Unique Direction-Dependent Acoustic-Phonon-Limited Carrier Mobility and Carrier Polarity.

    PubMed

    Xu, Yuehua; Dai, Jun; Zeng, Xiao Cheng

    2016-01-21

    The intrinsic acoustic-phonon-limited carrier mobility (μ) of Al2C monolayer sheet and nanoribbons are investigated using ab initio computation and deformation potential theory. It is found that the polarity of the room-temperature carrier mobility of the Al2C monolayer is direction-dependent, with μ of electron (e) and hole (h) being 2348 and 40.77 cm(2)/V/s, respectively, in the armchair direction and 59.95 (e) and 705.8 (h) in the zigzag direction. More interestingly, one-dimensional Al2C nanoribbons not only can retain the direction-dependent polarity but also may entail even higher mobility, in contrast to either the graphene nanoribbons which tend to exhibit lower μ compared to the two-dimensional graphene or the MoS2 nanoribbons which have reversed polarity compared to the MoS2 sheet. As an example, the Al-terminated zigzag nanoribbon with a width of 4.1 nm exhibits μ of 212.6 (e) and 2087 (h) cm(2)/V/s, while the C-terminated armchair nanoribbon with a width 2.6 nm exhibits μ of 1090 (e) and 673.9 (h) cm(2)/V/s; the C-terminated zigzag nanoribbon with a width 3.7 nm exhibits μ of 177.6 (e) and 1889 (h) cm(2)/V/s, and the Al-terminated armchair nanoribbon with a width 2.4 nm exhibits μ of 6695 (e) and 518.4 (h) cm(2)/V/s. The high carrier mobility, μ, coupled with polarity and direction dependence endows the Al2C sheet and nanoribbons with unique transport properties that can be exploited for special applications in nanoelectronics.

  17. North Pacific Acoustic Laboratory and Deep Water Acoustics

    DTIC Science & Technology

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. North Pacific Acoustic Laboratory and Deep Water...coherence of the received signal, while the ambient noise field is in direct competition with the received signal. Research conducted in the North Pacific ...The scientific objectives of the North Pacific Acoustic Laboratory and Deep Water Acoustics research are: 1. To study the spatial and temporal

  18. Evaluation of Acoustic Doppler Current Profiler to Measure Discharge at New York Power Authority's Niagara Power Project, Niagara Falls, New York

    USGS Publications Warehouse

    Zajd, Henry J.

    2007-01-01

    The need for accurate real-time discharge in the International Niagara River hydro power system requires reliable, accurate and reproducible data. The U.S. Geological Survey has been widely using Acoustic Doppler Current Profilers (ADCP) to accurately measure discharge in riverine channels since the mid-1990s. The use of the ADCP to measure discharge has remained largely untested at hydroelectric-generation facilities such as the New York Power Authority's (NYPA) Niagara Power Project in Niagara Falls, N.Y. This facility has a large, engineered diversion channel with the capacity of high volume discharges in excess of 100,000 cubic feet per second (ft3/s). Facilities such as this could benefit from the use of an ADCP, if the ADCP discharge measurements prove to be more time effective and accurate than those obtained from the flow-calculation techniques that are currently used. Measurements of diversion flow by an ADCP in the 'Pant Leg' diversion channel at the Niagara Power Project were made on November 6, 7, and 8, 2006, and compared favorably (within 1 percent) with those obtained concurrently by a conventional Price-AA current-meter measurement during one of the ADCP measurement sessions. The mean discharge recorded during each 2-hour individual ADCP measurement session compared favorably with (3.5 to 6.8 percent greater than) the discharge values computed by the flow-calculation method presently in use by NYPA. The use of ADCP technology to measure discharge could ultimately permit increased power-generation efficiency at the NYPA Niagara Falls Power Project by providing improved predictions of the amount of water (and thus the power output) available.

  19. Streamflow loss quantification for groundwater flow modeling using a wading-rod-mounted acoustic Doppler current profiler in a headwater stream

    NASA Astrophysics Data System (ADS)

    Pflügl, Christian; Hoehn, Philipp; Hofmann, Thilo

    2017-04-01

    Irrespective of the availability of various field measurement and modeling approaches, the quantification of interactions between surface water and groundwater systems remains associated with high uncertainty. Such uncertainties on stream-aquifer interaction have a high potential to misinterpret the local water budget and water quality significantly. Due to typically considerable temporal variation of stream discharge rates, it is desirable for the measurement of streamflow to reduce the measuring duration while reducing uncertainty. Streamflow measurements, according to the velocity-area method, have been performed along reaches of a losing-disconnected, subalpine headwater stream using a 2-dimensional, wading-rod-mounted acoustic Doppler current profiler (ADCP). The method was chosen, with stream morphology not allowing for boat-mounted setups, to reduce uncertainty compared to conventional, single-point streamflow measurements of similar measurement duration. Reach-averaged stream loss rates were subsequently quantified between 12 cross sections. They enabled the delineation of strongly infiltrating stream reaches and their differentiation from insignificantly infiltrating reaches. Furthermore, a total of 10 near-stream observation wells were constructed and/or equipped with pressure and temperature loggers. The time series of near-stream groundwater temperature data were cross-correlated with stream temperature time series to yield supportive qualitative information on the delineation of infiltrating reaches. Subsequently, as a reference parameterization, the hydraulic conductivity and specific yield of a numerical, steady-state model of groundwater flow, in the unconfined glaciofluvial aquifer adjacent to the stream, were inversely determined incorporating the inferred stream loss rates. Applying synthetic sets of infiltration rates, resembling increasing levels of uncertainty associated with single-point streamflow measurements of comparable duration, the

  20. Using Principal Component and Tidal Analysis as a Quality Metric for Detecting Systematic Heading Uncertainty in Long-Term Acoustic Doppler Current Profiler Data

    NASA Astrophysics Data System (ADS)

    Morley, M. G.; Mihaly, S. F.; Dewey, R. K.; Jeffries, M. A.

    2015-12-01

    Ocean Networks Canada (ONC) operates the NEPTUNE and VENUS cabled ocean observatories to collect data on physical, chemical, biological, and geological ocean conditions over multi-year time periods. Researchers can download real-time and historical data from a large variety of instruments to study complex earth and ocean processes from their home laboratories. Ensuring that the users are receiving the most accurate data is a high priority at ONC, requiring quality assurance and quality control (QAQC) procedures to be developed for all data types. While some data types have relatively straightforward QAQC tests, such as scalar data range limits that are based on expected observed values or measurement limits of the instrument, for other data types the QAQC tests are more comprehensive. Long time series of ocean currents from Acoustic Doppler Current Profilers (ADCP), stitched together from multiple deployments over many years is one such data type where systematic data biases are more difficult to identify and correct. Data specialists at ONC are working to quantify systematic compass heading uncertainty in long-term ADCP records at each of the major study sites using the internal compass, remotely operated vehicle bearings, and more analytical tools such as principal component analysis (PCA) to estimate the optimal instrument alignments. In addition to using PCA, some work has been done to estimate the main components of the current at each site using tidal harmonic analysis. This paper describes the key challenges and presents preliminary PCA and tidal analysis approaches used by ONC to improve long-term observatory current measurements.

  1. Acoustic sniper localization system

    NASA Astrophysics Data System (ADS)

    Prado, Gervasio; Dhaliwal, Hardave; Martel, Philip O.

    1997-02-01

    Technologies for sniper localization have received increased attention in recent months as American forces have been deployed to various trouble spots around the world. Among the technologies considered for this task acoustics is a natural choice for various reasons. The acoustic signatures of gunshots are loud and distinctive, making them easy to detect even in high noise background environments. Acoustics provides a passive sensing technology with excellent range and non line of sight capabilities. Last but not least, an acoustic sniper location system can be built at a low cost with off the shelf components. Despite its many advantages, the performance of acoustic sensors can degrade under adverse propagation conditions. Localization accuracy, although good, is usually not accurate enough to pinpoint a sniper's location in some scenarios (for example which widow in a building or behind which tree in a grove). For these more demanding missions, the acoustic sensor can be used in conjunction with an infra red imaging system that detects the muzzle blast of the gun. The acoustic system can be used to cue the pointing system of the IR camera in the direction of the shot's source.

  2. Modern Acoustics, Based on Metamaterials

    NASA Astrophysics Data System (ADS)

    Gan, Woon S.

    We discover parity invariance in acoustic field equation. Acoustic metamaterials are a special type of metamaterials with negative mass density and negative bulk modulus and the Poynting vector in opposite direction to wave propagation. This is also known as lefthanded material because the Poynting vector with mass density and bulk modulus form a lefthanded set. For lefthanded material the parity is -1. Double negativity and Poynting vector in opposite direction to wave propagation give rise to new phenomena in refraction diffraction and scattering of acoustic waves. These three are the basic mechanisms of sound propagation in medium. For each new mechanism, there are several new acoustic devices to be developed. Hence we call this the new acoustics. The PHONONICS 2011 to be held in Santa Fe, New Mexico, USA on May 29 - June 2, 2011 supports our idea of New Acoustics.

  3. Uniformity of spherical shock wave dynamically stabilized by two successive laser profiles in direct-drive inertial confinement fusion implosions

    SciTech Connect

    Temporal, M.; Canaud, B.; Garbett, W. J.; Ramis, R.

    2015-10-15

    The implosion uniformity of a directly driven spherical inertial confinement fusion capsule is considered within the context of the Laser Mégajoule configuration. Two-dimensional (2D) hydrodynamic simulations have been performed assuming irradiation with two laser beam cones located at 49° and 131° with respect to the axis of symmetry. The laser energy deposition causes an inward shock wave whose surface is tracked in time, providing the time evolution of its non-uniformity. The illumination model has been used to optimize the laser intensity profiles used as input in the 2D hydro-calculations. It is found that a single stationary laser profile does not maintain a uniform shock front over time. To overcome this drawback, it is proposed to use two laser profiles acting successively in time, in order to dynamically stabilize the non-uniformity of the shock front.

  4. OPTIM: Computer program to generate a vertical profile which minimizes aircraft fuel burn or direct operating cost. User's guide

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A profile of altitude, airspeed, and flight path angle as a function of range between a given set of origin and destination points for particular models of transport aircraft provided by NASA is generated. Inputs to the program include the vertical wind profile, the aircraft takeoff weight, the costs of time and fuel, certain constraint parameters and control flags. The profile can be near optimum in the sense of minimizing: (1) fuel, (2) time, or (3) a combination of fuel and time (direct operating cost (DOC)). The user can also, as an option, specify the length of time the flight is to span. The theory behind the technical details of this program is also presented.

  5. Shadow mask assisted direct growth of ZnO nanowires as a sensing medium for surface acoustic wave devices using a thermal evaporation method

    NASA Astrophysics Data System (ADS)

    Achath Mohanan, Ajay; Parthiban, R.; Ramakrishnan, N.

    2016-02-01

    Zinc oxide (ZnO) nanowires were directly synthesized on high temperature stable one-port surface acoustic wave (SAW) resonators made of LiNbO3 substrate and Pt/Ti electrodes using a self-seeding catalyst-free thermal evaporation method. To enhance post-growth device functionality, one half of an SAW resonator was masked along the interdigital transducer aperture length during the nanowire growth process using a stainless steel shadow mask, while the other half was used as the ZnO nanowire growth site. This was achieved by employing a precisely machined stainless steel sleeve to house the chip and mask in the reaction chamber during the nanowire growth process. The ZnO nanowire integrated SAW resonator exhibited ultraviolet radiation sensing abilities which indicated that the ZnO nanowires grown on the SAW device were able to interact with SAW propagation on the substrate even after the device was exposed to extremely harsh conditions during the nanowire growth process. The use of a thermal evaporation method, instead of the conventionally used solution-grown method for direct growth of ZnO nanowires on SAW devices, paves the way for future methods aimed at the fabrication of highly sensitive ZnO nanowire-LiNbO3 based SAW sensors utilizing coupled resonance phenomenon at the nanoscale.

  6. Acoustic imaging system

    DOEpatents

    Smith, Richard W.

    1979-01-01

    An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

  7. The research and preparation of a bi-layer biodegradable external sheath with directional drug release profiles for vein graft

    NASA Astrophysics Data System (ADS)

    Liu, Zhenjie; Guo, Zhenying; Si, Yi; Zhang, Xiangman; Shi, Zhenyu; Chen, Feng; Fu, Weiguo

    2013-11-01

    External sheath has been suggested for autologous vein grafts to inhibit neointimal hyperplasia and prevent anastomosis stricture. In this study, we prepared a bi-layer biodegradable paclitaxel-loaded sheaths with a synthetic copolymer poly(ethylene carbonate-ɛ-caprolactone) at room temperature. The bi-layer drug release profiles of the Paclitaxel-loaded (PTX-loaded) sheath significantly slow down the paclitaxel (PTX) release rates and result in a directional drug release way. Moreover, the nanofibrous layer of PTX-loaded poly(EC-CL) sheaths reduced the cytotoxicity and provided a better support for fibroblast adhesion and proliferation than the PTX-loaded layer of the sheaths. Thus, this study demonstrates that the bi-layer PTX-loaded poly(EC-CL) sheath with directional drug release profiles have a promising application for vein graft to against neointimal hyperplasia and anastomotic stricture.

  8. Flight effects on the aerodynamic and acoustic characteristics of inverted profile coannular nozzles, volume 3. [supersonic cruise aircraft research wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    Acoustic data from tests of the 0.75 area ratio coannular nozzle with ejector and the 1.2 area ratio coannular are presented in tables. Aerodynamic data acquired for the four test configurations are included.

  9. Broadband Acoustic Hyperbolic Metamaterial.

    PubMed

    Shen, Chen; Xie, Yangbo; Sui, Ni; Wang, Wenqi; Cummer, Steven A; Jing, Yun

    2015-12-18

    In this Letter, we report on the design and experimental characterization of a broadband acoustic hyperbolic metamaterial. The proposed metamaterial consists of multiple arrays of clamped thin plates facing the y direction and is shown to yield opposite signs of effective density in the x and y directions below a certain cutoff frequency, therefore, yielding a hyperbolic dispersion. Partial focusing and subwavelength imaging are experimentally demonstrated at frequencies between 1.0 and 2.5 kHz. The proposed metamaterial could open up new possibilities for acoustic wave manipulation and may find usage in medical imaging and nondestructive testing.

  10. Passive broadband acoustic thermometry

    NASA Astrophysics Data System (ADS)

    Anosov, A. A.; Belyaev, R. V.; Klin'shov, V. V.; Mansfel'd, A. D.; Subochev, P. V.

    2016-04-01

    The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8-3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

  11. Reflective echo tomographic imaging using acoustic beams

    DOEpatents

    Kisner, Roger; Santos-Villalobos, Hector J

    2014-11-25

    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.

  12. Real-time monitoring of methanol concentration using a shear horizontal surface acoustic wave sensor for direct methanol fuel cell without reference liquid measurement

    NASA Astrophysics Data System (ADS)

    Tada, Kyosuke; Nozawa, Takuya; Kondoh, Jun

    2017-07-01

    In recent years, there has been an increasing demand for sensors that continuously measure liquid concentrations and detect abnormalities in liquid environments. In this study, a shear horizontal surface acoustic wave (SH-SAW) sensor is applied for the continuous monitoring of liquid concentrations. As the SH-SAW sensor functions using the relative measurement method, it normally needs a reference at each measurement. However, if the sensor is installed in a liquid flow cell, it is difficult to measure a reference liquid. Therefore, it is important to establish an estimation method for liquid concentrations using the SH-SAW sensor without requiring a reference measurement. In this study, the SH-SAW sensor is installed in a direct methanol fuel cell to monitor the methanol concentration. The estimated concentration is compared with a conventional density meter. Moreover, the effect of formic acid is examined. When the fuel temperature is higher than 70 °C, it is necessary to consider the influence of liquid conductivity. Here, an estimation method for these cases is also proposed.

  13. Holocene lake level changes at a lowland lake in northeastern Germany inferred from acoustic sub-bottom profiling and a transect of sediment cores

    NASA Astrophysics Data System (ADS)

    Dietze, Elisabeth; Zawiska, Izabela; Słowiński, Michał; Brauer, Achim

    2015-04-01

    Holocene lake level changes were studied at Lake Fürstenseer See, a typical lake with complex basin morphology in northeastern German sandur area. An acoustic sub-bottom profile and a transect of four long sediment cores in the deepest lake sub-basin were analyzed. The cores were dated with AMS-14C and correlated with multiple proxies (sediment facies, μ-XRF, macrofossils, subfossil Cladocera, carbonate isotopes). At sites in 10 and 15 m water depth, shifts in the sand-mud boundary, i.e. sediment limit sensu Digerfeldt (1986), allowed quantitative estimates of the absolute amplitude of lake level changes. At sites in 20 and 23 m water depth, the negative correlation of Ca and Ti reflect lake level changes qualitatively. During high lake stands massive organic muds were deposited. Lower lake levels isolated the lake sub-basins which reduced the overall water circulation and lead to the deposition of Ti-poor carbonate muds. Furthermore, macrofossil and subfossil Cladocera analyses were used as proxies for the intense reworking at the slope and for the trophic state of the lake, respectively. Lake levels were up to 4 m higher, e.g. around 5000 cal. yrs BP and during the Medieval time period (see also Kaiser et al., 2014). During the early to mid-Holocene (between 9400 and 6400 cal. yrs BP), Lake Fürstenseer See fluctuated at an at least 3-m lower level. Further water level changes can be related to known climatic events and regional human impact. Digerfeldt, G., 1986. Studies on past lake-level fluctuations. In Berglund, B. (ed.), Handbook of Holocene Palaeoecology and Palaeohydrology: 127-144. John Wiley & Sons, New York. Kaiser, K., Küster, M., Fülling, A., Theuerkauf, M., Dietze, E., Graventein, H., Koch, P.J., Bens, O., Brauer, A., 2014. Littoral landforms and pedosedimentary sequences indicating late Holocene lake-level changes in northern central Europe ' A case study from northeastern Germany. Geomorphology 216, 58-78.

  14. Comparison between direct-sequence and multicarrier spread-spectrum acoustic communications in time-varying channels.

    PubMed

    van Walree, P A

    2010-12-01

    Underwater communication experiments have been conducted in the Norwegian Oslofjord. Two modulation schemes are compared in a 7-kHz frequency band on a 14-kHz center frequency. The first scheme is direct-sequence spread spectrum (DSSS), using a 7-chip spreading code to achieve a raw data rate of 1000 bps on a single carrier. The second scheme is multicarrier spread spectrum (MCSS) and accomplishes spreading by using seven subbands. The DSSS receiver equalizes on the chips prior to explicit symbol despreading, whereas MCSS features joint multiband equalization and despreading. Four channels are examined, from nearly static to overspread. In slowly varying channels, MCSS offers the best performance. DSSS has the best tracking potential for rapidly varying channels, where the challenge is to obtain reliable chip decisions before symbol despreading. The tracking potential can be realized to some extent by hypothesis-feedback equalization. It is further shown that adaptive equalizers are capable of code conversion, i.e., the DSSS receiver can demodulate the MCSS waveform, and vice versa. Neither receiver requires knowledge of the spreading code in order to despread the data.

  15. How to chase a tracer - combining conventional salt tracer testing and direct push electrical conductivity profiling for enhanced aquifer characterization

    NASA Astrophysics Data System (ADS)

    Vienken, Thomas; Huber, Emanuel; Kreck, Manuel; Huggenberger, Peter; Dietrich, Peter

    2017-01-01

    Tracer testing is a well-established technique in hydrogeological site characterization. However, certain a priori knowledge of the hydraulic regime is required beforehand to avoid test failure, e.g. miss of tracer. In this study, we propose a novel tracer test concept for the hydraulic characterization of shallow unconsolidated sedimentary deposits when only scarce a priori information on the hydraulic regime is available. Therefore, we combine conventional salt tracer testing with direct push vertical high resolution electrical conductivity logging. The proposed tracer test concept was successfully tested on coarse, braided river deposits of the Tagliamento River, Italy. With limited a priori information available two tracer tests were performed in three days to reliably determine ground water flow direction and velocity allowing on-site decision-making to adaptively install observation wells for reliable breakthrough curve measurements. Furthermore, direct push vertical electrical profiling provided essential information about the plume characteristics with outstanding measurement resolution and efficiency.

  16. Musical Acoustics

    NASA Astrophysics Data System (ADS)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  17. Holograms for acoustics

    NASA Astrophysics Data System (ADS)

    Melde, Kai; Mark, Andrew G.; Qiu, Tian; Fischer, Peer

    2016-09-01

    Holographic techniques are fundamental to applications such as volumetric displays, high-density data storage and optical tweezers that require spatial control of intricate optical or acoustic fields within a three-dimensional volume. The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source. Modern computer-generated holography skips the process of recording a hologram from a physical scene, and instead calculates the required phase profile before rendering it for reconstruction. In ultrasound applications, the phase profile is typically generated by discrete and independently driven ultrasound sources; however, these can only be used in small numbers, which limits the complexity or degrees of freedom that can be attained in the wavefront. Here we introduce monolithic acoustic holograms, which can reconstruct diffraction-limited acoustic pressure fields and thus arbitrary ultrasound beams. We use rapid fabrication to craft the holograms and achieve reconstruction degrees of freedom two orders of magnitude higher than commercial phased array sources. The technique is inexpensive, appropriate for both transmission and reflection elements, and scales well to higher information content, larger aperture size and higher power. The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound.

  18. Holograms for acoustics.

    PubMed

    Melde, Kai; Mark, Andrew G; Qiu, Tian; Fischer, Peer

    2016-09-22

    Holographic techniques are fundamental to applications such as volumetric displays, high-density data storage and optical tweezers that require spatial control of intricate optical or acoustic fields within a three-dimensional volume. The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source. Modern computer-generated holography skips the process of recording a hologram from a physical scene, and instead calculates the required phase profile before rendering it for reconstruction. In ultrasound applications, the phase profile is typically generated by discrete and independently driven ultrasound sources; however, these can only be used in small numbers, which limits the complexity or degrees of freedom that can be attained in the wavefront. Here we introduce monolithic acoustic holograms, which can reconstruct diffraction-limited acoustic pressure fields and thus arbitrary ultrasound beams. We use rapid fabrication to craft the holograms and achieve reconstruction degrees of freedom two orders of magnitude higher than commercial phased array sources. The technique is inexpensive, appropriate for both transmission and reflection elements, and scales well to higher information content, larger aperture size and higher power. The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound.

  19. Acoustical oceanography

    NASA Astrophysics Data System (ADS)

    The Acoustical Society of America has formed a Technical Specialty Group on Acoustical Oceanography. At ASA meetings the new group will have special sessions where they will give invited and contributed papers and have panel discussions about ocean parameters that are measured effectively by acoustical techniques.The first special sessions will be May 22-23, 1990, at the ASA meeting at Pennsylvania State University, University Park. The focus on May 22 will be acoustical techniques for detection and measurement of internal waves and turbulence; conveners are Robert Pinkel of Scripps Institution of Oceanography, La Jolla, Calif., and Herman Medwin of the Naval Postgraduate School, Monterey, Calif. Acoustical studies of the physical and biological characteristics of ocean mass boundaries are the discussion topic on May 23. The convener is C. S. Clay, University of Wisconsin, Madison.

  20. O2 density and temperature profiles retrieving from direct solar Lyman-alpha radiation measurements

    NASA Astrophysics Data System (ADS)

    Guineva, V.; Witt, G.; Gumbel, J.; Khaplanov, M.; Werner, R.; Hedin, J.; Neichev, S.; Kirov, B.; Bankov, L.; Gramatikov, P.; Tashev, V.; Popov, M.; Hauglund, K.; Hansen, G.; Ilstad, J.; Wold, H.

    2009-12-01

    The resonance transition 2P-2S of the atomic hydrogen (Lyman-alpha emission) is the strongest and most conspicuous feature in the solar EUV spectrum. The Lyman-alpha radiation transfer depends on the resonance scattering from the hydrogen atoms in the atmosphere and on the O2 absorption. Since the Lyman-alpha extinction in the atmosphere is a measure for the column density of the oxygen molecules, the atmospheric O2 density and temperature profiles can be calculated thereof. A detector of solar Lyman-alpha radiation was manufactured in the Stara Zagora Department of the Solar-Terrestrial Influences Laboratory (STIL). Its basic part is an ionization camera, filled in with NO. A 60 V power supply is applied to the chamber. The produced photoelectric current from the sensor is fed to a two-channel amplifier, providing analog signal. The characteristics of the Lyman-alpha detector were studied. It passed successfully all tests and the results showed that the so-designed instrument could be used in rocket experiments to measure the Lymanalpha flux. From the measurements of the detector, the Lyman-alpha vertical profile can be obtained. Programs are created to compute the O2 density, atmospheric power and temperature profiles based on Lymanalpha data. The detector design appertained to ASLAF project (Attenuation of the Solar Lyman-Alpha Flux), a scientific cooperation between STIL—Bul.Acad.Sci., Stara Zagora Department and the Atmospheric Physics Group at the Department of Meteorology (MISU), Stockholm University, Sweden. The joint project was part of the rocket experiment HotPay I, in the ALOMAR eARI Project, EU’s 6th Framework Programme, Andøya Rocket Range, Andenes, Norway. The project is partly financed by the Bulgarian Ministry of Science and Education.

  1. Direct evidence of cubic difference tone propagation by intracochlear acoustic pressure measurements in the guinea-pig.

    PubMed

    Avan, P; Magnan, P; Smurzynski, J; Probst, R; Dancer, A

    1998-05-01

    The fine tuning mechanisms involved in the normal processing of sound in the cochlea are non-linear, hence combination tones are generated inside the cochlea when a pair of low-level pure tones with neighbouring frequencies f1 and f2 is used as a stimulus. Their detection as sounds in the ear canal proves that they undergo backward propagation in the cochlea and through the middle ear, and the non-invasive measurement of the combination tone at 2f1-f2, called the cubic difference tone (CDT), has become a routine method of monitoring cochlear function. In order to gain information on the hypothetical places where CDTs are generated, on their intracochlear levels and propagation velocities, direct measurements of CDT pressure waves were carried out in scala vestibuli and tympani of the first and second turn of the guinea-pig cochlea. Cubic difference tones at 2f1-f2 varied from 0.75 to 9 kHz and were measured with a miniature piezoresistive transducer. Its high sensitivity allowed the detection of CDTs whenever their levels exceeded 5 dB SPL in the ear canal, i.e. 40 dB SPL (re: 20 microPa) inside the cochlea. The levels of CDTs were similar in scala vestibuli of the first and second turn. Phase comparisons between measurements at 2f1-f2 in the first and second turn allowed determination of the place where the CDT phase was minimum. It provided an estimation of the generation site of the CDT, which appeared to be close to the place tuned to f2 for stimulus levels lower than 70 dB SPL. Forward and backward travel times from one turn to the other were assessed at several frequencies, and both values were shorter than 0.2 ms. In contrast, the overall 'round-trip' delay of CDTs, measured in the ear canal, was about five times larger, suggesting that local filtering processes rather than propagation delays account for the overall CDT delay.

  2. Future directions in anxiety disorders: profiles and perspectives of leading contributors.

    PubMed

    Norton, P J; Asmundson, G J; Cox, B J; Norton, G R

    2000-01-01

    Eight of the most influential clinicians and researchers in the study and treatment of anxiety disorders were identified by polling professional members of the Anxiety Disorders Association of America. These eight individuals are (in alphabetical order): James C. Ballenger, David H. Barlow, Aaron T. Beck, David M. Clark, Edna B. Foa, Rick G. Heimberg, Donald F. Klein, and Isaac M. Marks. Each offered their thoughts on a set of questions concerning the current and future status of the anxiety disorders field. Profiles and perspectives of these individuals are presented.

  3. Direct current resistivity profiling to study distribution of water in the unsaturated zone near the Amargosa Desert Research Site, Nevada

    USGS Publications Warehouse

    Abraham, Jared D.; Lucius, Jeffrey E.

    2004-01-01

    In order to study the distribution of water in the unsaturated zone and potential for ground-water recharge near the Amargosa Desert Research Site south of Beatty, Nevada, the U.S. Geological Survey collected direct-current resistivity measurements along three profiles in May 2003 using an eight-channel resistivity imaging system. Resistivity data were collected along profiles across the ADRS, across a poorly incised (distributary) channel system of the Amargosa River southwest of the ADRS, and across a well-incised flood plain of the Amargosa River northwest of the ADRS. This report describes results of an initial investigation to estimate the distribution of water in the unsaturated zone and to evaluate the shallow subsurface stratigraphy near the ADRS. The geophysical method of dc resistivity was employed by using automated data collection with numerous electrodes. 'Cross sections' of resistivity, produced by using an inversion algorithm on the field data, at the three field sites are presented and interpreted.

  4. Acoustic Rectification in Dispersive Media

    NASA Technical Reports Server (NTRS)

    Cantrell, John H.

    2008-01-01

    It is shown that the shapes of acoustic radiation-induced static strain and displacement pulses (rectified acoustic pulses) are defined locally by the energy density of the generating waveform. Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms. The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica.

  5. ACOUSTIC RECTIFICATION IN DISPERSIVE MEDIA

    SciTech Connect

    Cantrell, John H.

    2009-03-03

    It is shown that the shapes of acoustic radiation-induced static strain and displacement pulses (rectified acoustic pulses) are defined locally by the energy density of the generating waveform. Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms. The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica.

  6. Genetic profiling and epidermal growth factor receptor-directed therapy in nonsmall cell lung cancer.

    PubMed

    Cadranel, J; Zalcman, G; Sequist, L

    2011-01-01

    The principle of preferentially selecting patients most likely to benefit from therapy according to their genetic profile has led to substantial clinical benefit in some tumour types, and has potential to considerably refine treatment in advanced nonsmall cell lung cancer (NSCLC). Effective, reliable use of molecular biomarkers to inform clinical practice requires the standardisation of testing methods and careful assessment of biomarkers' predictive and prognostic value. Although a number of studies have shown that patients with activating mutations in exons 18-21 of the epidermal growth factor receptor (EGFR) gene respond particularly well to gefitinib and erlotinib, a prospective, randomised study was needed to differentiate between the prognostic and predictive value of EGFR mutations. From one such study, it appeared that mutational testing should become standard at diagnosis, at least for adenocarcinoma patients with a never or low smoking history, as clinical predictors are insufficient to optimise treatment. However, outstanding questions remain: what are the treatment options for patients with tumours resistant to erlotinib/gefitinib? What conclusions about treatment can we draw from EGFR copy number or KRAS mutation status? What role should anti-EGFR antibodies play in NSCLC treatment, and in which patients? This review considers current evidence linking biomarker profile to efficacy of EGFR-targeted therapy in NSCLC, and clinical implications of recent findings.

  7. The importance of Guthrie cards and other medical samples for the direct matching of disaster victims using DNA profiling.

    PubMed

    Hartman, D; Benton, L; Morenos, L; Beyer, J; Spiden, M; Stock, A

    2011-02-25

    The identification of disaster victims through the use of DNA analysis is an integral part of any Disaster Victim Identification (DVI) response, regardless of the scale and nature of the disaster. As part of the DVI response to the 2009 Victorian Bushfires Disaster, DNA analysis was performed to assist in the identification of victims through kinship (familial matching to relatives) or direct (self source sample) matching of DNA profiles. Although most of the DNA identifications achieved were to reference samples from relatives, there were a number of DNA identifications (12) made through direct matching. Guthrie cards, which have been collected in Australia over the past 30 years, were used to provide direct reference samples. Of the 236 ante-mortem (AM) samples received, 21 were Guthrie cards and one was a biopsy specimen; all yielding complete DNA profiles when genotyped. This publication describes the use of such Biobanks and medical specimens as a sample source for the recovery of good quality DNA for comparisons to post-mortem (PM) samples.

  8. Rapid identification of a Mycobacterium tuberculosis full genetic drug resistance profile through whole genome sequencing directly from sputum.

    PubMed

    Nimmo, Camus; Doyle, Ronan; Burgess, Carrie; Williams, Rachel; Gorton, Rebecca; McHugh, Timothy D; Brown, Mike; Morris-Jones, Stephen; Booth, Helen; Breuer, Judith

    2017-09-01

    Resistance to second-line tuberculosis drugs is common, but slow to diagnose with phenotypic drug sensitivity testing. Rapid molecular tests speed up diagnosis, but can only detect limited mutations. Whole genome sequencing (WGS) of culture isolates can generate a complete genetic drug resistance profile, but is delayed by the initial culture step. In the case presented here, successful WGS directly from sputum was achieved using targeted enrichment. A 29-year-old Nigerian woman was diagnosed with tuberculosis. Xpert MTB/RIF and Hain line probe assays identified rpoB and inhA mutations consistent with rifampicin and intermediate isoniazid resistance, and a further possible mutation conferring fluoroquinolone resistance. WGS directly from sputum identified a further inhA mutation consistent with high-level isoniazid resistance and confirmed the absence of fluoroquinolone resistance. Isoniazid was stopped, and the patient has completed 18 months of a fluoroquinolone-based regimen without relapse. Compared to rapid molecular tests (which can only examine a limited number of mutations) and WGS of culture isolates (which requires a culture step), WGS directly from sputum can quickly generate a complete genetic drug resistance profile. In this case, WGS altered the clinical management of drug-resistant tuberculosis and demonstrated potential for guiding individualized drug treatment where second-line drug resistance is common. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

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

    DOEpatents

    Vo-Dinh, Tuan; Norton, Stephen J.

    2001-01-01

    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.

  10. Effect of readout direction in the edge profile on the modulation transfer function of computed radiographic systems by use of the edge method.

    PubMed

    Tanaka, Nobukazu; Morishita, Junji; Tsuda, Norisato; Ohki, Masafumi

    2013-07-01

    We investigated the effect of the readout direction of the edge profile obtained by the edge method on the presampled modulation transfer function (MTF) in various computed radiographic (CR) systems. There were no differences in the MTFs derived from two edge profiles in the sub-scanning direction of four CR systems used in this study. On the other hand, the MTFs measured at a readout direction from the low (edge) to the high (direct exposure) exposure region were higher than those measured at a readout direction from the high to the low exposure region in the laser-beam scanning direction for three of the four CR systems. Although this phenomenon depends on the CR system, it is important to understand and indicate both MTFs at the two edge profiles in the laser-beam scanning direction for accurate assessment of the resolution property.

  11. Acute Shear Stress Direction Dictates Adherent Cell Remodeling and Verifies Shear Profile of Spinning Disc Assays

    PubMed Central

    Fuhrmann, Alexander; Engler, Adam J.

    2015-01-01

    Several methods have been developed to quantify population level changes in cell attachment strength given its large heterogeneity. One such method is the rotating disc chamber or “spinning disc” in which a range of shear forces are applied to attached cells to quantify detachment force, i.e. attachment strength, which can be heterogeneous within cell populations. However, computing the exact force vectors that act upon cells is complicated by complex flow fields and variable cell morphologies. Recent observations suggest that cells may remodel their morphology and align during acute shear exposure, but contrary to intuition, shear is not orthogonal to the radial direction. Here we theoretically derive the magnitude and direction of applied shear and demonstrate that cells, under certain physiological conditions, align in this direction within minutes. Shear force magnitude is also experimentally verified which validates that for spread cells shear forces and not torque or drag dominate in this assay, and demonstrates that the applied force per cell area is largely independent of initial morphology. These findings suggest that direct quantified comparison of the effects of shear on a wide array of cell types and conditions can be made with confidence using this assay without the need for computational or numerical modeling. PMID:25619322

  12. Interpreting Self-Directed Search Profiles: Validity of the "Rule of Eight"

    ERIC Educational Resources Information Center

    Glavin, Kevin W.; Savickas, Mark L.

    2011-01-01

    Based on the standard error of measurement, Holland (1985) suggested the "rule of eight" for determining the meaningfulness of differences between two summary scores on the Self Directed Search. The present study empirically examined the rule's validity for practice. The participants were 2397 (1497 females and 900 males) undergraduate…

  13. An Automatic Method of Direct Interpretation of Residual Gravity Anomaly Profiles due to Spheres and Cylinders

    NASA Astrophysics Data System (ADS)

    Asfahani, J.; Tlas, M.

    2008-05-01

    We have developed a least-squares minimization approach to determine the depth and the amplitude coefficient of a buried structure from residual gravity anomaly profile. This approach is basically based on application of Werner deconvolution method to gravity formulas due to spheres and cylinders, and solving a set of algebraic linear equations to estimate the two-model parameters. The validity of this new method is demonstrated through studying and analyzing two synthetic gravity anomalies, using simulated data generated from a known model with different random error components and a known statistical distribution. After being theoretically proven, this approach was applied on two real field gravity anomalies from Cuba and Sweden. The agreement between the results obtained by the proposed method and those obtained by other interpretation methods is good and comparable. Moreover, the depth obtained by the proposed approach is found to be in very good agreement with that obtained from drilling information.

  14. Machine learning of global phosphoproteomic profiles enables discrimination of direct versus indirect kinase substrates.

    PubMed

    Kanshin, Evgeny; Giguere, Sebastien; Cheng, Jing; Tyers, Michael D; Thibault, Pierre

    2017-03-06

    Mass spectrometry allows quantification of tens of thousands of phosphorylation sites from minute amounts of cellular material. Despite this wealth of information, our understanding of phosphorylation-based signaling is limited, in part because it is not possible to deconvolute substrate phosphorylation that is directly mediated by a particular kinase versus phosphorylation that is mediated by downstream kinases. Here, we describe a framework for assignment of direct in-vivo kinase substrates using a combination of selective chemical inhibition, quantitative phosphoproteomics, and machine learning techniques. Our workflow allows classification of phosphorylation events following inhibition of an analog-sensitive kinase into kinase-independent effects of the inhibitor, direct effects on cognate substrates and indirect effects mediated by downstream kinases or phosphatases. We applied this method to identify many direct targets of Cdc28 and Snf1 kinases in the budding yeast S. cerevisiae. Global phosphoproteome analysis of acute time-series demonstrated that dephosphorylation of direct kinase substrates occurs more rapidly compared to indirect substrates, both after inhibitor treatment and under a physiological nutrient shift in wild-type cells. Mutagenesis experiments revealed a high proportion of functionally relevant phosphorylation sites on Snf1 targets. For example, Snf1 itself was inhibited through autophosphorylation on S391 and new phosphosites were discovered that modulate the activity of the Reg1 regulatory subunit of the Glc7 phosphatase and the Gal83 β-subunit of SNF1 complex. This methodology applies to any kinase for which a functional analog sensitive version can be constructed to facilitate the dissection of the global phosphorylation network.

  15. Acoustic and Perceptual Measurements of Prosody Production on the Profiling Elements of Prosodic Systems in Children by Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Diehl, Joshua John; Paul, Rhea

    2013-01-01

    Prosody production atypicalities are a feature of autism spectrum disorders (ASDs), but behavioral measures of performance have failed to provide detail on the properties of these deficits. We used acoustic measures of prosody to compare children with ASDs to age-matched groups with learning disabilities and typically developing peers. Overall,…

  16. Acoustic and Perceptual Measurements of Prosody Production on the Profiling Elements of Prosodic Systems in Children by Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Diehl, Joshua John; Paul, Rhea

    2013-01-01

    Prosody production atypicalities are a feature of autism spectrum disorders (ASDs), but behavioral measures of performance have failed to provide detail on the properties of these deficits. We used acoustic measures of prosody to compare children with ASDs to age-matched groups with learning disabilities and typically developing peers. Overall,…

  17. Feature Profile Evolution During Etching of SiO2 in Radio-Frequency or Direct-Current Plasmas

    NASA Astrophysics Data System (ADS)

    Zhao, Zhanqiang; Dai, Zhongling; Wang, Younian

    2012-01-01

    We have developed a plasma etching simulator to investigate the evolution of pattern profiles in SiO2 material under different plasma conditions. This model focuses on energy and angular dependent etching yield (physical sputtering in this paper), neutral and ion angular distributions, and reflection of ions or neutrals on the surface of a photoresist or SiO2. The effect of positive charge accumulation on the surface of insulated mask or SiO2 is studied and the charge accumulation contributes to a deflection of ion trajectory. The wafer profile evolution has been simulated using a cellular-automata-like method under radio-frequency (RF) bias and direct-current (DC) bias, respectively. On the basis of the critical role of angular distribution of ions or neutrals, the wafer profile evolution has been simulated for different variances of angles. Observed microtrenching has been well reproduced in the simulator. The ratio of neutrals to ions has been considered and the result shows that because the neutrals are not accelerated by an electric field, their energy is much lower compared with ions, so they are easily reflected on the surface of SiO2, which makes the trench shallower.

  18. Direct profiling of cancer biomarkers in tumor tissue using a multiplexed nanostructured microelectrode integrated circuit.

    PubMed

    Fang, Zhichao; Soleymani, Leyla; Pampalakis, Georgios; Yoshimoto, Maisa; Squire, Jeremy A; Sargent, Edward H; Kelley, Shana O

    2009-10-27

    The analysis of panels of nucleic acid biomarkers offers valuable diagnostic and prognostic information for cancer management. A cost-effective, highly sensitive electronic chip would offer an ideal platform for clinical biomarker readout and would have maximal utility if it was (i) multiplexed, enabling on-chip assays of multiple biomarkers, and (ii) able to perform direct (PCR-free) readout of disease-related genes. Here we report a chip onto which we integrate novel nanostructured microelectrodes and with which we directly detect cancer biomarkers in heterogeneous biological samples-both cell extracts and tumor tissues. Coarse photolithographic microfabrication defines a multiplexed sensing array; bottom-up fabrication of nanostructured microelectrodes then provides sensing elements. We analyzed a panel of mRNA samples for prostate cancer related gene fusions using the chip. We accurately identified gene fusions that correlate with aggressive prostate cancer and distinguished these from fusions associated with slower-progressing forms of the disease. The multiplexed nanostructured microelectrode integrated circuit reported herein provides direct, amplification-free, sample-to-answer in under 1 h using the 10 ng of mRNA readily available in biopsy samples.

  19. Acoustic tooth cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S. (Inventor)

    1982-01-01

    An acoustic oral hygiene unit is described that uses acoustic energy to oscillate mild abrasive particles in a water suspension which is then directed in a low pressure stream onto the teeth. The oscillating abrasives scrub the teeth clean removing food particles, plaque, calculous, and other foreign material from tooth surfaces, interproximal areas, and tooth-gingiva interface more effectively than any previous technique. The relatively low power output and the basic design makes the invention safe and convenient for everyday use in the home without special training. This invention replaces all former means of home dental prophylaxis, and requires no augmentation to fulfill all requirements for daily oral hygienic care.

  20. Influence of the vertical absorption profile of mixed Asian dust plumes on aerosol direct radiative forcing over East Asia

    NASA Astrophysics Data System (ADS)

    Noh, Young Min; Lee, Kwonho; Kim, Kwanchul; Shin, Sung-Kyun; Müller, Detlef; Shin, Dong Ho

    2016-08-01

    We estimate the aerosol direct radiative forcing (ADRF) and heating rate profiles of mixed East Asian dust plumes in the solar wavelength region ranging from 0.25 to 4.0 μm using the Santa Barbara Discrete Ordinate Atmospheric Radiative Transfer (SBDART) code. Vertical profiles of aerosol extinction coefficients and single-scattering albedos (SSA) were derived from measurements with a multi-wavelength Raman lidar system. The data are used as input parameters for our radiative transfer calculations. We considered four cases of radiative forcing in SBDART: 1. dust, 2. pollution, 3. mixed dust plume and the use of vertical profiles of SSA, and 4. mixed dust plumes and the use of column-averaged values of SSA. In our sensitivity study we examined the influence of SSA and aerosol layer height on our results. The ADRF at the surface and in the atmosphere shows a small dependence on the specific shape of the aerosol extinction vertical profile and its light-absorption property for all four cases. In contrast, at the top of the atmosphere (TOA), the ADRF is largely affected by the vertical distribution of the aerosols extinction. This effect increases if the light-absorption capacity (decrease of SSA) of the aerosols increases. We find different radiative effects in situations in which two layers of aerosols had different light-absorption properties. The largest difference was observed at the TOA for an absorbing aerosol layer at high altitude in which we considered in one case the vertical profile of SSA and in another case the column-averaged SSA only. The ADRF at the TOA increases when the light-absorbing aerosol layer is located above 3 km altitude. The differences between height-resolved SSA, which can be obtained from lidar data, and total layer-mean SSA indicates that the use of a layer-mean SSA can be rather misleading as it can induce a large error in the calculation of the ADRF at the TOA, which in turn may cause errors in the vertical profiles of heating rates.

  1. Zonal Flow Velocimetry in Spherical Couette Flow using Acoustic Modes

    NASA Astrophysics Data System (ADS)

    Adams, Matthew M.; Mautino, Anthony R.; Stone, Douglas R.; Triana, Santiago A.; Lekic, Vedran; Lathrop, Daniel P.

    2015-11-01

    We present studies of spherical Couette flows using the technique of acoustic mode Doppler velocimetry. This technique uses rotational splittings of acoustic modes to infer the azimuthal velocity profile of a rotating flow, and is of special interest in experiments where direct flow visualization is impractical. The primary experimental system consists of a 60 cm diameter outer spherical shell concentric with a 20 cm diameter sphere, with air or nitrogen gas serving as the working fluid. The geometry of the system approximates that of the Earth's core, making these studies geophysically relevant. A turbulent shear flow is established in the system by rotating the inner sphere and outer shell at different rates. Acoustic modes of the fluid volume are excited using a speaker and measured via microphones, allowingdetermination of rotational splittings. Preliminary results comparing observed splittings with those predicted by theory are presented. While the majority of these studies were performed in the 60 cm diameter device using nitrogen gas, some work has also been done looking at acoustic modes in the 3 m diameter liquid sodium spherical Couette experiment. Prospects for measuring zonal velocity profiles in a wide variety of experiments are discussed.

  2. Direct detection of blood in fingermarks by MALDI MS profiling and imaging.

    PubMed

    Bradshaw, R; Bleay, S; Clench, M R; Francese, S

    2014-03-01

    The determination of the presence of blood in fingermarks constitutes important intelligence in a criminal investigation as it helps to reconstruct the events that have taken place at a scene of crime. Various methodologies have been reported and are currently employed for the detection of the presence of blood including optical, spectroscopic and chemical development approaches. However, most methods only give an indication that blood may be present and, therefore, these methods are described as presumptive tests. Here we show the use of Matrix-Assisted Laser Desorption Ionisation Mass Spectrometry Profiling and Imaging (MALDI MSP and MALDI MSI) for the determination of the presence of blood in fingermarks by specifically detecting the molecules of haem and haemoglobin through their mass-to-charge ratios. Furthermore, preliminary experiments are shown which demonstrate that this technology is compatible with other methods currently employed for enhancing fingermarks in blood (or contaminated by blood). The application of the developed protocols to a crime scene blood trace, demonstrates the feasibility of using this technology in routine casework. These findings open up a new line of research for the development of robust MALDI MSP and MALDI MSI protocols for the detection and chemical imaging of bloodied marks. Copyright © 2013 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Laser desorption/ionization mass spectrometry for direct profiling and imaging of small molecules from raw biological materials

    SciTech Connect

    Cha, Sangwon

    2008-01-01

    Matrix-assisted laser desorption/ionization(MALDI) mass spectrometry(MS) has been widely used for analysis of biological molecules, especially macromolecules such as proteins. However, MALDI MS has a problem in small molecule (less than 1 kDa) analysis because of the signal saturation by organic matrixes in the low mass region. In imaging MS (IMS), inhomogeneous surface formation due to the co-crystallization process by organic MALDI matrixes limits the spatial resolution of the mass spectral image. Therefore, to make laser desorption/ionization (LDI) MS more suitable for mass spectral profiling and imaging of small molecules directly from raw biological tissues, LDI MS protocols with various alternative assisting materials were developed and applied to many biological systems of interest. Colloidal graphite was used as a matrix for IMS of small molecules for the first time and methodologies for analyses of small metabolites in rat brain tissues, fruits, and plant tissues were developed. With rat brain tissues, the signal enhancement for cerebroside species by colloidal graphite was observed and images of cerebrosides were successfully generated by IMS. In addition, separation of isobaric lipid ions was performed by imaging tandem MS. Directly from Arabidopsis flowers, flavonoids were successfully profiled and heterogeneous distribution of flavonoids in petals was observed for the first time by graphite-assisted LDI(GALDI) IMS.

  4. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  5. Source localization from an elevated acoustic sensor array in a refractive atmosphere.

    PubMed

    Ostashev, Vladimir E; Scanlon, Michael V; Wilson, D Keith; Vecherin, Sergey N

    2008-12-01

    Localization of sound sources on the ground from an acoustic sensor array elevated on a tethered aerostat is considered. To improve estimation of the source coordinates, one should take into account refraction of sound rays due to atmospheric stratification. Using a geometrical acoustics approximation for a stratified moving medium, formulas for the source coordinates are derived that account for sound refraction. The source coordinates are expressed in terms of the direction of sound propagation as measured by the sensor array, its coordinates, and the vertical profiles of temperature and wind velocity. Employing these formulas and typical temperature and wind velocity profiles in the atmosphere, it is shown numerically that sound refraction is important for accurate predictions of the source coordinates. Furthermore, it is shown that the effective sound speed approximation, which is widely used in atmospheric acoustics, fails to correctly predict the source coordinates if the grazing angle of sound propagation is relatively large.

  6. Direct detection and drug-resistance profiling of bacteremias using inertial microfluidics

    PubMed Central

    Hou, Han Wei; Bhattacharyya, Roby P.; Hung, Deborah T.; Han, Jongyoon

    2015-01-01

    Detection of bacteria in bloodstream infections and their antibiotic susceptibility patterns is critical to guide therapeutic decision-making for optimal patient care. Current culture-based assays are too slow (>48 hrs), leading to excessive up-front use of broad-spectrum antibiotics and/or incorrect antibiotic choices due to resistant bacteria, each with deleterious consequences for patient care and public health. To approach this problem, we describe a method to rapidly isolate bacteria from whole blood using inertial microfluidics and directly determine pathogen identity and antibiotic susceptibility with hybridization-based RNA detection. Using the principle of Dean flow fractionation, bacteria are separated from host blood cells in a label-free separation method with efficient recovery of even low abundance bacteria. Ribosomal RNA detection can then be applied for direct identification of low abundance pathogens (~100/mL) from blood without culturing or enzymatic amplification. Messenger RNA detection of antibiotic-responsive transcripts after brief drug exposure permits rapid susceptibility determination from bacteria with minimal culturing (~105/mL). This unique coupling of microfluidic cell separation with RNA-based molecular detection techniques represents significant progress towards faster diagnostics (~8 hours) to guide antibiotic therapy. PMID:25882432

  7. Direct detection and drug-resistance profiling of bacteremias using inertial microfluidics.

    PubMed

    Hou, Han Wei; Bhattacharyya, Roby P; Hung, Deborah T; Han, Jongyoon

    2015-05-21

    Detection of bacteria in bloodstream infections and their antibiotic susceptibility patterns is critical to guide therapeutic decision-making for optimal patient care. Current culture-based assays are too slow (>48 h), leading to excessive up-front use of broad-spectrum antibiotics and/or incorrect antibiotic choices due to resistant bacteria, each with deleterious consequences for patient care and public health. To approach this problem, we describe a method to rapidly isolate bacteria from whole blood using inertial microfluidics and directly determine pathogen identity and antibiotic susceptibility with hybridization-based RNA detection. Using the principle of Dean flow fractionation, bacteria are separated from host blood cells in a label-free separation method with efficient recovery of even low abundance bacteria. Ribosomal RNA detection can then be applied for direct identification of low abundance pathogens (~100 per mL) from blood without culturing or enzymatic amplification. Messenger RNA detection of antibiotic-responsive transcripts after brief drug exposure permits rapid susceptibility determination from bacteria with minimal culturing (~10(5) per mL). This unique coupling of microfluidic cell separation with RNA-based molecular detection techniques represents significant progress towards faster diagnostics (~8 hours) to guide antibiotic therapy.

  8. Acoustic agglomeration methods and apparatus

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B. (Inventor)

    1984-01-01

    Methods are described for using acoustic energy to agglomerate fine particles on the order of one micron diameter that are suspended in gas, to provide agglomerates large enough for efficient removal by other techniques. The gas with suspended particles, is passed through the length of a chamber while acoustic energy at a resonant chamber mode is applied to set up one or more acoustic standing wave patterns that vibrate the suspended particles to bring them together so they agglomerate. Several widely different frequencies can be applied to efficiently vibrate particles of widely differing sizes. The standing wave pattern can be applied along directions transversed to the flow of the gas. The particles can be made to move in circles by applying acoustic energy in perpendicular directions with the energy in both directions being of the same wavelength but 90 deg out of phase.

  9. Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile

    DOEpatents

    Leung, Ka-Ngo; Gordon, K.C.; Kippenhan, D.O.; Purgalis, P.; Moussa, D.; Williams, M.D.; Wilde, S.B.; West, M.W.

    1987-10-16

    A large area directly heated lanthanum hexaboride (LaB/sub 6/) cathode system is disclosed. The system comprises a LaB/sub 6/ cathode element generally circular in shape about a central axis. The cathode element has a head with an upper substantially planar emission surface, and a lower downwardly and an intermediate body portion which diminishes in cross-section from the head towards the base of the cathode element. A central rod is connected to the base of the cathode element and extends along the central axis. Plural upstanding spring fingers are urged against an outer peripheral contact surface of the head end to provide a mechanical and electrical connection to the cathode element. 7 figs

  10. Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile

    DOEpatents

    Leung, Ka-Ngo; Gordon, Keith C.; Kippenham, Dean O.; Purgalis, Peter; Moussa, David; Williams, Malcom D.; Wilde, Stephen B.; West, Mark W.

    1989-01-01

    A large area directly heated lanthanum hexaboride (LaB.sub.6) cathode system (10) is disclosed. The system comprises a LaB.sub.6 cathode element (11) generally circular in shape about a central axis. The cathode element (11) has a head (21) with an upper substantially planar emission surface (23), and a lower downwardly and an intermediate body portion (26) which diminishes in cross-section from the head (21) towards the base (22) of the cathode element (11). A central rod (14) is connected to the base (22) of the cathode element (11) and extends along the central axis. Plural upstanding spring fingers (37) are urged against an outer peripheral contact surface (24) of the head end (21) to provide a mechanical and electrical connection to the cathode element (11).

  11. Method and apparatus for generating acoustic energy

    DOEpatents

    Guerrero, Hector N.

    2002-01-01

    A method and apparatus for generating and emitting amplified coherent acoustic energy. A cylindrical transducer is mounted within a housing, the transducer having an acoustically open end and an acoustically closed end. The interior of the transducer is filled with an active medium which may include scattering nuclei. Excitation of the transducer produces radially directed acoustic energy in the active medium, which is converted by the dimensions of the transducer, the acoustically closed end thereof, and the scattering nuclei, to amplified coherent acoustic energy directed longitudinally within the transducer. The energy is emitted through the acoustically open end of the transducer. The emitted energy can be used for, among other things, effecting a chemical reaction or removing scale from the interior walls of containment vessels.

  12. ACOUSTIC FORMING FOR ENHANCED DEWATERING AND FORMATION

    SciTech Connect

    Cyrus K Aidun

    2007-11-30

    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.

  13. Direct measurement of solids: High temperature sensing Final report Experimental development and testing of high temperature pulsed EMATs (electromagnetic acoustic transducer):

    SciTech Connect

    Boyd, D.M.; Spanner, G.E.; Sperline, P.D.

    1988-04-01

    A pulsed laser/pulsed EMAT (electromagnetic acoustic transducer) receiver system has been demonstrated for measuring the time of flight of acoustic signals in hot steel samples. Attenuation and signal-to-noise ratio are important parameters to be monitored. A continuous contact EMAT application was not achieved; thermal analysis found that contact times of 5 seconds with cooling times of 45 seconds are required at 1300/degree/C. The equipment requires field hardening and improved packaging before system reliability can be assessed. 22 refs., 35 figs. (DLC)

  14. Adsorption behaviour of direct yellow 50 onto cotton fiber: equilibrium, kinetic and thermodynamic profile.

    PubMed

    Ismail, L F M; Sallam, H B; Abo Farha, S A; Gamal, A M; Mahmoud, G E A

    2014-10-15

    This study investigated the adsorption of direct yellow 50 onto cotton fiber from aqueous solution by using parameters, such as pH, temperature, contact time, initial dye concentration and the effect of sodium sulphate, tetrasodium edate and trisodium citrate. The extent of dye adsorption increased with increasing contact time, temperature and solution concentration. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. It was found that the Langmuir equation fit better than the Freundlich equation. The results show that the presence of SE and SC significantly enhance the dye adsorption onto cotton fiber. In addition, the adsorption data obtained at different temperatures of DY50 onto cotton fiber were applied to pseudo first-order, pseudo second-order and intraparticle diffusion models. The rates of adsorption were found to conform to pseudo second-order kinetics with good correlation. Also, free energy of adsorption (ΔG(#)), enthalpy (ΔH(#)), and entropy (ΔS(#)) changes were determined to predict the nature of adsorption. The positive value of the enthalpy change indicated that the adsorption is endothermic process. The activation energy, Ea, is ranged between 1.9 and 3.9kJmol(-1) indicated that the adsorption process is a physisorption. This low value of Ea generally indicates diffusion controlled process.

  15. Adsorption behaviour of direct yellow 50 onto cotton fiber: Equilibrium, kinetic and thermodynamic profile

    NASA Astrophysics Data System (ADS)

    Ismail, L. F. M.; Sallam, H. B.; Abo Farha, S. A.; Gamal, A. M.; Mahmoud, G. E. A.

    2014-10-01

    This study investigated the adsorption of direct yellow 50 onto cotton fiber from aqueous solution by using parameters, such as pH, temperature, contact time, initial dye concentration and the effect of sodium sulphate, tetrasodium edate and trisodium citrate. The extent of dye adsorption increased with increasing contact time, temperature and solution concentration. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. It was found that the Langmuir equation fit better than the Freundlich equation. The results show that the presence of SE and SC significantly enhance the dye adsorption onto cotton fiber. In addition, the adsorption data obtained at different temperatures of DY50 onto cotton fiber were applied to pseudo first-order, pseudo second-order and intraparticle diffusion models. The rates of adsorption were found to conform to pseudo second-order kinetics with good correlation. Also, free energy of adsorption (ΔG#), enthalpy (ΔH#), and entropy (ΔS#) changes were determined to predict the nature of adsorption. The positive value of the enthalpy change indicated that the adsorption is endothermic process. The activation energy, Ea, is ranged between 1.9 and 3.9 kJ mol-1 indicated that the adsorption process is a physisorption. This low value of Ea generally indicates diffusion controlled process.

  16. An automated robotic platform for rapid profiling oligosaccharide analysis of monoclonal antibodies directly from cell culture.

    PubMed

    Doherty, Margaret; Bones, Jonathan; McLoughlin, Niaobh; Telford, Jayne E; Harmon, Bryan; DeFelippis, Michael R; Rudd, Pauline M

    2013-11-01

    Oligosaccharides attached to Asn297 in each of the CH2 domains of monoclonal antibodies play an important role in antibody effector functions by modulating the affinity of interaction with Fc receptors displayed on cells of the innate immune system. Rapid, detailed, and quantitative N-glycan analysis is required at all stages of bioprocess development to ensure the safety and efficacy of the therapeutic. The high sample numbers generated during quality by design (QbD) and process analytical technology (PAT) create a demand for high-performance, high-throughput analytical technologies for comprehensive oligosaccharide analysis. We have developed an automated 96-well plate-based sample preparation platform for high-throughput N-glycan analysis using a liquid handling robotic system. Complete process automation includes monoclonal antibody (mAb) purification directly from bioreactor media, glycan release, fluorescent labeling, purification, and subsequent ultra-performance liquid chromatography (UPLC) analysis. The entire sample preparation and commencement of analysis is achieved within a 5-h timeframe. The automated sample preparation platform can easily be interfaced with other downstream analytical technologies, including mass spectrometry (MS) and capillary electrophoresis (CE), for rapid characterization of oligosaccharides present on therapeutic antibodies. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Ultrasound assisted simultaneous reduction and direct functionalization of graphene oxide with thermal and cytotoxicity profile.

    PubMed

    Maktedar, Shrikant S; Avashthi, Gopal; Singh, Man

    2017-01-01

    The new sonochemical approach for simultaneous reduction and direct functionalization of graphene oxide (GrO) has been developed. The GrO was functionalized with 2-Aminobenzoxazole (2-ABOZ) in twenty min with complete deletion of hazardous steps. The significance of ultrasound was exemplified with the comparative conventional methods. The newly prepared f-(2-ABOZ)GrO was extensively characterized with near edge X-ray absorption fine structure (NEXAFS) spectroscopy, (13)C solid state NMR, XPS, XRD, HRTEM, SAED, AFM, Raman, UV-vis, FTIR and TGA. The thermal stability of f-(2-ABOZ)GrO was confirmed with total percentage weight loss in TGA. The biological activity of f-(2-ABOZ)GrO was explored with MCF-7 and Vero cell lines. The inherent cytotoxicity was evaluated with SRB assay at 10, 20, 40 and 80μgmL(-1). The estimated cell viabilities were >78% with f-(2-ABOZ) GrO. A high cytocompatibility of f-(2-ABOZ)GrO was ensured with in vitro evaluation on living cell lines, and low toxicity of f-(2-ABOZ)GrO was confirmed its excellent biocompatibility. The morphological effect on Vero cell line evidently supports the formation of biocompatible f-(2-ABOZ)GrO. Therefore, f-(2-ABOZ)GrO was emerged as an advanced functional material for thermally stable biocompatible coatings.

  18. Direct measurement of local dissolved oxygen concentration spatial profiles in a cell culture environment.

    PubMed

    Kagawa, Yuki; Matsuura, Katsuhisa; Shimizu, Tatsuya; Tsuneda, Satoshi

    2015-06-01

    Controlling local dissolved oxygen concentration (DO) in media is critical for cell or tissue cultures. Various biomaterials and culture methods have been developed to modulate DO. Direct measurement of local DO in cultures has not been validated as a method to test DO modulation. In the present study we developed a DO measurement system equipped with a Clark-type oxygen microelectrode manipulated with 1 μm precision in three-dimensional space to explore potential applications for tissue engineering. By determining the microelectrode tip position precisely against the bottom plane of culture dishes with rat or human cardiac cells in static monolayer culture, we successfully obtained spatial distributions of DO in the medium. Theoretical quantitative predictions fit the obtained data well. Based on analyses of the variance between samples, we found the data reflected "local" oxygen consumption in the vicinity of the microelectrode and the detection of temporal changes in oxygen consumption rates of cultured cells was limited by the diffusion rate of oxygen in the medium. This oxygen measuring system monitors local oxygen consumption and production with high spatial resolution, and can potentially be used with recently developed oxygen modulating biomaterials to design microenvironments and non-invasively monitor local DO dynamics during culture. © 2015 Wiley Periodicals, Inc.

  19. Robust acoustic wave manipulation of bubbly liquids

    SciTech Connect

    Gumerov, N. A.; Akhatov, I. S.; Ohl, C.-D.; Sametov, S. P.; Khazimullin, M. V.; Gonzalez-Avila, S. R.

    2016-03-28

    Experiments with water–air bubbly liquids when exposed to acoustic fields of frequency ∼100 kHz and intensity below the cavitation threshold demonstrate that bubbles ∼30 μm in diameter can be “pushed” away from acoustic sources by acoustic radiation independently from the direction of gravity. This manifests formation and propagation of acoustically induced transparency waves (waves of the bubble volume fraction). In fact, this is a collective effect of bubbles, which can be described by a mathematical model of bubble self-organization in acoustic fields that matches well with our experiments.

  20. Analysis of gene expression profiles of Lactobacillus paracasei induced by direct contact with Saccharomyces cerevisiae through recognition of yeast mannan

    PubMed Central

    YAMASAKI-YASHIKI, Shino; SAWADA, Hiroshi; KINO-OKA, Masahiro; KATAKURA, Yoshio

    2016-01-01

    Co-culture of lactic acid bacteria (LAB) and yeast induces specific responses that are not observed in pure culture. Gene expression profiles of Lactobacillus paracasei ATCC 334 co-cultured with Saccharomyces cerevisiae IFO 0216 were analyzed by DNA microarray, and the responses induced by direct contact with the yeast cells were investigated. Coating the LAB cells with recombinant DnaK, which acts as an adhesive protein between LAB and yeast cells, enhanced the ratio of adhesion of the LAB cells to the yeast cells. The signals induced by direct contact were clarified by removal of the LAB cells unbound to the yeast cells. The genes induced by direct contact with heat-inactivated yeast cells were very similar to both those induced by the intact yeast cells and those induced by a soluble mannan. The top 20 genes upregulated by direct contact with the heat-inactivated yeast cells mainly encoded proteins related to exopolysaccharide synthesis, modification of surface proteins, and transport systems. In the case of the most upregulated gene, LSEI_0669, encoding a protein that has a region homologous to polyprenyl glycosylphosphotransferase, the expression level was upregulated 7.6-, 11.0-, and 8.8-fold by the heat-inactivated yeast cells, the intact yeast cells, and the soluble mannan, respectively, whereas it was only upregulated 1.8-fold when the non-adherent LAB cells were not removed before RNA extraction. Our results indicated that the LAB responded to direct contact with the yeast cells through recognition of mannan on the surface of the yeast. PMID:28243547